Bug Summary

File:tools/clang/lib/Sema/SemaOverload.cpp
Warning:line 9644, column 50
Called C++ object pointer is null

Annotated Source Code

1//===--- SemaOverload.cpp - C++ Overloading -------------------------------===//
2//
3// The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This file provides Sema routines for C++ overloading.
11//
12//===----------------------------------------------------------------------===//
13
14#include "clang/Sema/Overload.h"
15#include "clang/AST/ASTContext.h"
16#include "clang/AST/CXXInheritance.h"
17#include "clang/AST/DeclObjC.h"
18#include "clang/AST/Expr.h"
19#include "clang/AST/ExprCXX.h"
20#include "clang/AST/ExprObjC.h"
21#include "clang/AST/TypeOrdering.h"
22#include "clang/Basic/Diagnostic.h"
23#include "clang/Basic/DiagnosticOptions.h"
24#include "clang/Basic/PartialDiagnostic.h"
25#include "clang/Basic/TargetInfo.h"
26#include "clang/Sema/Initialization.h"
27#include "clang/Sema/Lookup.h"
28#include "clang/Sema/SemaInternal.h"
29#include "clang/Sema/Template.h"
30#include "clang/Sema/TemplateDeduction.h"
31#include "llvm/ADT/DenseSet.h"
32#include "llvm/ADT/Optional.h"
33#include "llvm/ADT/STLExtras.h"
34#include "llvm/ADT/SmallPtrSet.h"
35#include "llvm/ADT/SmallString.h"
36#include <algorithm>
37#include <cstdlib>
38
39using namespace clang;
40using namespace sema;
41
42static bool functionHasPassObjectSizeParams(const FunctionDecl *FD) {
43 return llvm::any_of(FD->parameters(), [](const ParmVarDecl *P) {
44 return P->hasAttr<PassObjectSizeAttr>();
45 });
46}
47
48/// A convenience routine for creating a decayed reference to a function.
49static ExprResult
50CreateFunctionRefExpr(Sema &S, FunctionDecl *Fn, NamedDecl *FoundDecl,
51 bool HadMultipleCandidates,
52 SourceLocation Loc = SourceLocation(),
53 const DeclarationNameLoc &LocInfo = DeclarationNameLoc()){
54 if (S.DiagnoseUseOfDecl(FoundDecl, Loc))
55 return ExprError();
56 // If FoundDecl is different from Fn (such as if one is a template
57 // and the other a specialization), make sure DiagnoseUseOfDecl is
58 // called on both.
59 // FIXME: This would be more comprehensively addressed by modifying
60 // DiagnoseUseOfDecl to accept both the FoundDecl and the decl
61 // being used.
62 if (FoundDecl != Fn && S.DiagnoseUseOfDecl(Fn, Loc))
63 return ExprError();
64 if (auto *FPT = Fn->getType()->getAs<FunctionProtoType>())
65 S.ResolveExceptionSpec(Loc, FPT);
66 DeclRefExpr *DRE = new (S.Context) DeclRefExpr(Fn, false, Fn->getType(),
67 VK_LValue, Loc, LocInfo);
68 if (HadMultipleCandidates)
69 DRE->setHadMultipleCandidates(true);
70
71 S.MarkDeclRefReferenced(DRE);
72 return S.ImpCastExprToType(DRE, S.Context.getPointerType(DRE->getType()),
73 CK_FunctionToPointerDecay);
74}
75
76static bool IsStandardConversion(Sema &S, Expr* From, QualType ToType,
77 bool InOverloadResolution,
78 StandardConversionSequence &SCS,
79 bool CStyle,
80 bool AllowObjCWritebackConversion);
81
82static bool IsTransparentUnionStandardConversion(Sema &S, Expr* From,
83 QualType &ToType,
84 bool InOverloadResolution,
85 StandardConversionSequence &SCS,
86 bool CStyle);
87static OverloadingResult
88IsUserDefinedConversion(Sema &S, Expr *From, QualType ToType,
89 UserDefinedConversionSequence& User,
90 OverloadCandidateSet& Conversions,
91 bool AllowExplicit,
92 bool AllowObjCConversionOnExplicit);
93
94
95static ImplicitConversionSequence::CompareKind
96CompareStandardConversionSequences(Sema &S, SourceLocation Loc,
97 const StandardConversionSequence& SCS1,
98 const StandardConversionSequence& SCS2);
99
100static ImplicitConversionSequence::CompareKind
101CompareQualificationConversions(Sema &S,
102 const StandardConversionSequence& SCS1,
103 const StandardConversionSequence& SCS2);
104
105static ImplicitConversionSequence::CompareKind
106CompareDerivedToBaseConversions(Sema &S, SourceLocation Loc,
107 const StandardConversionSequence& SCS1,
108 const StandardConversionSequence& SCS2);
109
110/// GetConversionRank - Retrieve the implicit conversion rank
111/// corresponding to the given implicit conversion kind.
112ImplicitConversionRank clang::GetConversionRank(ImplicitConversionKind Kind) {
113 static const ImplicitConversionRank
114 Rank[(int)ICK_Num_Conversion_Kinds] = {
115 ICR_Exact_Match,
116 ICR_Exact_Match,
117 ICR_Exact_Match,
118 ICR_Exact_Match,
119 ICR_Exact_Match,
120 ICR_Exact_Match,
121 ICR_Promotion,
122 ICR_Promotion,
123 ICR_Promotion,
124 ICR_Conversion,
125 ICR_Conversion,
126 ICR_Conversion,
127 ICR_Conversion,
128 ICR_Conversion,
129 ICR_Conversion,
130 ICR_Conversion,
131 ICR_Conversion,
132 ICR_Conversion,
133 ICR_Conversion,
134 ICR_OCL_Scalar_Widening,
135 ICR_Complex_Real_Conversion,
136 ICR_Conversion,
137 ICR_Conversion,
138 ICR_Writeback_Conversion,
139 ICR_Exact_Match, // NOTE(gbiv): This may not be completely right --
140 // it was omitted by the patch that added
141 // ICK_Zero_Event_Conversion
142 ICR_C_Conversion,
143 ICR_C_Conversion_Extension
144 };
145 return Rank[(int)Kind];
146}
147
148/// GetImplicitConversionName - Return the name of this kind of
149/// implicit conversion.
150static const char* GetImplicitConversionName(ImplicitConversionKind Kind) {
151 static const char* const Name[(int)ICK_Num_Conversion_Kinds] = {
152 "No conversion",
153 "Lvalue-to-rvalue",
154 "Array-to-pointer",
155 "Function-to-pointer",
156 "Function pointer conversion",
157 "Qualification",
158 "Integral promotion",
159 "Floating point promotion",
160 "Complex promotion",
161 "Integral conversion",
162 "Floating conversion",
163 "Complex conversion",
164 "Floating-integral conversion",
165 "Pointer conversion",
166 "Pointer-to-member conversion",
167 "Boolean conversion",
168 "Compatible-types conversion",
169 "Derived-to-base conversion",
170 "Vector conversion",
171 "Vector splat",
172 "Complex-real conversion",
173 "Block Pointer conversion",
174 "Transparent Union Conversion",
175 "Writeback conversion",
176 "OpenCL Zero Event Conversion",
177 "C specific type conversion",
178 "Incompatible pointer conversion"
179 };
180 return Name[Kind];
181}
182
183/// StandardConversionSequence - Set the standard conversion
184/// sequence to the identity conversion.
185void StandardConversionSequence::setAsIdentityConversion() {
186 First = ICK_Identity;
187 Second = ICK_Identity;
188 Third = ICK_Identity;
189 DeprecatedStringLiteralToCharPtr = false;
190 QualificationIncludesObjCLifetime = false;
191 ReferenceBinding = false;
192 DirectBinding = false;
193 IsLvalueReference = true;
194 BindsToFunctionLvalue = false;
195 BindsToRvalue = false;
196 BindsImplicitObjectArgumentWithoutRefQualifier = false;
197 ObjCLifetimeConversionBinding = false;
198 CopyConstructor = nullptr;
199}
200
201/// getRank - Retrieve the rank of this standard conversion sequence
202/// (C++ 13.3.3.1.1p3). The rank is the largest rank of each of the
203/// implicit conversions.
204ImplicitConversionRank StandardConversionSequence::getRank() const {
205 ImplicitConversionRank Rank = ICR_Exact_Match;
206 if (GetConversionRank(First) > Rank)
207 Rank = GetConversionRank(First);
208 if (GetConversionRank(Second) > Rank)
209 Rank = GetConversionRank(Second);
210 if (GetConversionRank(Third) > Rank)
211 Rank = GetConversionRank(Third);
212 return Rank;
213}
214
215/// isPointerConversionToBool - Determines whether this conversion is
216/// a conversion of a pointer or pointer-to-member to bool. This is
217/// used as part of the ranking of standard conversion sequences
218/// (C++ 13.3.3.2p4).
219bool StandardConversionSequence::isPointerConversionToBool() const {
220 // Note that FromType has not necessarily been transformed by the
221 // array-to-pointer or function-to-pointer implicit conversions, so
222 // check for their presence as well as checking whether FromType is
223 // a pointer.
224 if (getToType(1)->isBooleanType() &&
225 (getFromType()->isPointerType() ||
226 getFromType()->isObjCObjectPointerType() ||
227 getFromType()->isBlockPointerType() ||
228 getFromType()->isNullPtrType() ||
229 First == ICK_Array_To_Pointer || First == ICK_Function_To_Pointer))
230 return true;
231
232 return false;
233}
234
235/// isPointerConversionToVoidPointer - Determines whether this
236/// conversion is a conversion of a pointer to a void pointer. This is
237/// used as part of the ranking of standard conversion sequences (C++
238/// 13.3.3.2p4).
239bool
240StandardConversionSequence::
241isPointerConversionToVoidPointer(ASTContext& Context) const {
242 QualType FromType = getFromType();
243 QualType ToType = getToType(1);
244
245 // Note that FromType has not necessarily been transformed by the
246 // array-to-pointer implicit conversion, so check for its presence
247 // and redo the conversion to get a pointer.
248 if (First == ICK_Array_To_Pointer)
249 FromType = Context.getArrayDecayedType(FromType);
250
251 if (Second == ICK_Pointer_Conversion && FromType->isAnyPointerType())
252 if (const PointerType* ToPtrType = ToType->getAs<PointerType>())
253 return ToPtrType->getPointeeType()->isVoidType();
254
255 return false;
256}
257
258/// Skip any implicit casts which could be either part of a narrowing conversion
259/// or after one in an implicit conversion.
260static const Expr *IgnoreNarrowingConversion(const Expr *Converted) {
261 while (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(Converted)) {
262 switch (ICE->getCastKind()) {
263 case CK_NoOp:
264 case CK_IntegralCast:
265 case CK_IntegralToBoolean:
266 case CK_IntegralToFloating:
267 case CK_BooleanToSignedIntegral:
268 case CK_FloatingToIntegral:
269 case CK_FloatingToBoolean:
270 case CK_FloatingCast:
271 Converted = ICE->getSubExpr();
272 continue;
273
274 default:
275 return Converted;
276 }
277 }
278
279 return Converted;
280}
281
282/// Check if this standard conversion sequence represents a narrowing
283/// conversion, according to C++11 [dcl.init.list]p7.
284///
285/// \param Ctx The AST context.
286/// \param Converted The result of applying this standard conversion sequence.
287/// \param ConstantValue If this is an NK_Constant_Narrowing conversion, the
288/// value of the expression prior to the narrowing conversion.
289/// \param ConstantType If this is an NK_Constant_Narrowing conversion, the
290/// type of the expression prior to the narrowing conversion.
291NarrowingKind
292StandardConversionSequence::getNarrowingKind(ASTContext &Ctx,
293 const Expr *Converted,
294 APValue &ConstantValue,
295 QualType &ConstantType) const {
296 assert(Ctx.getLangOpts().CPlusPlus && "narrowing check outside C++")((Ctx.getLangOpts().CPlusPlus && "narrowing check outside C++"
) ? static_cast<void> (0) : __assert_fail ("Ctx.getLangOpts().CPlusPlus && \"narrowing check outside C++\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303373/tools/clang/lib/Sema/SemaOverload.cpp"
, 296, __PRETTY_FUNCTION__))
;
297
298 // C++11 [dcl.init.list]p7:
299 // A narrowing conversion is an implicit conversion ...
300 QualType FromType = getToType(0);
301 QualType ToType = getToType(1);
302
303 // A conversion to an enumeration type is narrowing if the conversion to
304 // the underlying type is narrowing. This only arises for expressions of
305 // the form 'Enum{init}'.
306 if (auto *ET = ToType->getAs<EnumType>())
307 ToType = ET->getDecl()->getIntegerType();
308
309 switch (Second) {
310 // 'bool' is an integral type; dispatch to the right place to handle it.
311 case ICK_Boolean_Conversion:
312 if (FromType->isRealFloatingType())
313 goto FloatingIntegralConversion;
314 if (FromType->isIntegralOrUnscopedEnumerationType())
315 goto IntegralConversion;
316 // Boolean conversions can be from pointers and pointers to members
317 // [conv.bool], and those aren't considered narrowing conversions.
318 return NK_Not_Narrowing;
319
320 // -- from a floating-point type to an integer type, or
321 //
322 // -- from an integer type or unscoped enumeration type to a floating-point
323 // type, except where the source is a constant expression and the actual
324 // value after conversion will fit into the target type and will produce
325 // the original value when converted back to the original type, or
326 case ICK_Floating_Integral:
327 FloatingIntegralConversion:
328 if (FromType->isRealFloatingType() && ToType->isIntegralType(Ctx)) {
329 return NK_Type_Narrowing;
330 } else if (FromType->isIntegralType(Ctx) && ToType->isRealFloatingType()) {
331 llvm::APSInt IntConstantValue;
332 const Expr *Initializer = IgnoreNarrowingConversion(Converted);
333
334 // If it's value-dependent, we can't tell whether it's narrowing.
335 if (Initializer->isValueDependent())
336 return NK_Dependent_Narrowing;
337
338 if (Initializer &&
339 Initializer->isIntegerConstantExpr(IntConstantValue, Ctx)) {
340 // Convert the integer to the floating type.
341 llvm::APFloat Result(Ctx.getFloatTypeSemantics(ToType));
342 Result.convertFromAPInt(IntConstantValue, IntConstantValue.isSigned(),
343 llvm::APFloat::rmNearestTiesToEven);
344 // And back.
345 llvm::APSInt ConvertedValue = IntConstantValue;
346 bool ignored;
347 Result.convertToInteger(ConvertedValue,
348 llvm::APFloat::rmTowardZero, &ignored);
349 // If the resulting value is different, this was a narrowing conversion.
350 if (IntConstantValue != ConvertedValue) {
351 ConstantValue = APValue(IntConstantValue);
352 ConstantType = Initializer->getType();
353 return NK_Constant_Narrowing;
354 }
355 } else {
356 // Variables are always narrowings.
357 return NK_Variable_Narrowing;
358 }
359 }
360 return NK_Not_Narrowing;
361
362 // -- from long double to double or float, or from double to float, except
363 // where the source is a constant expression and the actual value after
364 // conversion is within the range of values that can be represented (even
365 // if it cannot be represented exactly), or
366 case ICK_Floating_Conversion:
367 if (FromType->isRealFloatingType() && ToType->isRealFloatingType() &&
368 Ctx.getFloatingTypeOrder(FromType, ToType) == 1) {
369 // FromType is larger than ToType.
370 const Expr *Initializer = IgnoreNarrowingConversion(Converted);
371
372 // If it's value-dependent, we can't tell whether it's narrowing.
373 if (Initializer->isValueDependent())
374 return NK_Dependent_Narrowing;
375
376 if (Initializer->isCXX11ConstantExpr(Ctx, &ConstantValue)) {
377 // Constant!
378 assert(ConstantValue.isFloat())((ConstantValue.isFloat()) ? static_cast<void> (0) : __assert_fail
("ConstantValue.isFloat()", "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303373/tools/clang/lib/Sema/SemaOverload.cpp"
, 378, __PRETTY_FUNCTION__))
;
379 llvm::APFloat FloatVal = ConstantValue.getFloat();
380 // Convert the source value into the target type.
381 bool ignored;
382 llvm::APFloat::opStatus ConvertStatus = FloatVal.convert(
383 Ctx.getFloatTypeSemantics(ToType),
384 llvm::APFloat::rmNearestTiesToEven, &ignored);
385 // If there was no overflow, the source value is within the range of
386 // values that can be represented.
387 if (ConvertStatus & llvm::APFloat::opOverflow) {
388 ConstantType = Initializer->getType();
389 return NK_Constant_Narrowing;
390 }
391 } else {
392 return NK_Variable_Narrowing;
393 }
394 }
395 return NK_Not_Narrowing;
396
397 // -- from an integer type or unscoped enumeration type to an integer type
398 // that cannot represent all the values of the original type, except where
399 // the source is a constant expression and the actual value after
400 // conversion will fit into the target type and will produce the original
401 // value when converted back to the original type.
402 case ICK_Integral_Conversion:
403 IntegralConversion: {
404 assert(FromType->isIntegralOrUnscopedEnumerationType())((FromType->isIntegralOrUnscopedEnumerationType()) ? static_cast
<void> (0) : __assert_fail ("FromType->isIntegralOrUnscopedEnumerationType()"
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303373/tools/clang/lib/Sema/SemaOverload.cpp"
, 404, __PRETTY_FUNCTION__))
;
405 assert(ToType->isIntegralOrUnscopedEnumerationType())((ToType->isIntegralOrUnscopedEnumerationType()) ? static_cast
<void> (0) : __assert_fail ("ToType->isIntegralOrUnscopedEnumerationType()"
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303373/tools/clang/lib/Sema/SemaOverload.cpp"
, 405, __PRETTY_FUNCTION__))
;
406 const bool FromSigned = FromType->isSignedIntegerOrEnumerationType();
407 const unsigned FromWidth = Ctx.getIntWidth(FromType);
408 const bool ToSigned = ToType->isSignedIntegerOrEnumerationType();
409 const unsigned ToWidth = Ctx.getIntWidth(ToType);
410
411 if (FromWidth > ToWidth ||
412 (FromWidth == ToWidth && FromSigned != ToSigned) ||
413 (FromSigned && !ToSigned)) {
414 // Not all values of FromType can be represented in ToType.
415 llvm::APSInt InitializerValue;
416 const Expr *Initializer = IgnoreNarrowingConversion(Converted);
417
418 // If it's value-dependent, we can't tell whether it's narrowing.
419 if (Initializer->isValueDependent())
420 return NK_Dependent_Narrowing;
421
422 if (!Initializer->isIntegerConstantExpr(InitializerValue, Ctx)) {
423 // Such conversions on variables are always narrowing.
424 return NK_Variable_Narrowing;
425 }
426 bool Narrowing = false;
427 if (FromWidth < ToWidth) {
428 // Negative -> unsigned is narrowing. Otherwise, more bits is never
429 // narrowing.
430 if (InitializerValue.isSigned() && InitializerValue.isNegative())
431 Narrowing = true;
432 } else {
433 // Add a bit to the InitializerValue so we don't have to worry about
434 // signed vs. unsigned comparisons.
435 InitializerValue = InitializerValue.extend(
436 InitializerValue.getBitWidth() + 1);
437 // Convert the initializer to and from the target width and signed-ness.
438 llvm::APSInt ConvertedValue = InitializerValue;
439 ConvertedValue = ConvertedValue.trunc(ToWidth);
440 ConvertedValue.setIsSigned(ToSigned);
441 ConvertedValue = ConvertedValue.extend(InitializerValue.getBitWidth());
442 ConvertedValue.setIsSigned(InitializerValue.isSigned());
443 // If the result is different, this was a narrowing conversion.
444 if (ConvertedValue != InitializerValue)
445 Narrowing = true;
446 }
447 if (Narrowing) {
448 ConstantType = Initializer->getType();
449 ConstantValue = APValue(InitializerValue);
450 return NK_Constant_Narrowing;
451 }
452 }
453 return NK_Not_Narrowing;
454 }
455
456 default:
457 // Other kinds of conversions are not narrowings.
458 return NK_Not_Narrowing;
459 }
460}
461
462/// dump - Print this standard conversion sequence to standard
463/// error. Useful for debugging overloading issues.
464LLVM_DUMP_METHOD__attribute__((noinline)) __attribute__((__used__)) void StandardConversionSequence::dump() const {
465 raw_ostream &OS = llvm::errs();
466 bool PrintedSomething = false;
467 if (First != ICK_Identity) {
468 OS << GetImplicitConversionName(First);
469 PrintedSomething = true;
470 }
471
472 if (Second != ICK_Identity) {
473 if (PrintedSomething) {
474 OS << " -> ";
475 }
476 OS << GetImplicitConversionName(Second);
477
478 if (CopyConstructor) {
479 OS << " (by copy constructor)";
480 } else if (DirectBinding) {
481 OS << " (direct reference binding)";
482 } else if (ReferenceBinding) {
483 OS << " (reference binding)";
484 }
485 PrintedSomething = true;
486 }
487
488 if (Third != ICK_Identity) {
489 if (PrintedSomething) {
490 OS << " -> ";
491 }
492 OS << GetImplicitConversionName(Third);
493 PrintedSomething = true;
494 }
495
496 if (!PrintedSomething) {
497 OS << "No conversions required";
498 }
499}
500
501/// dump - Print this user-defined conversion sequence to standard
502/// error. Useful for debugging overloading issues.
503void UserDefinedConversionSequence::dump() const {
504 raw_ostream &OS = llvm::errs();
505 if (Before.First || Before.Second || Before.Third) {
506 Before.dump();
507 OS << " -> ";
508 }
509 if (ConversionFunction)
510 OS << '\'' << *ConversionFunction << '\'';
511 else
512 OS << "aggregate initialization";
513 if (After.First || After.Second || After.Third) {
514 OS << " -> ";
515 After.dump();
516 }
517}
518
519/// dump - Print this implicit conversion sequence to standard
520/// error. Useful for debugging overloading issues.
521void ImplicitConversionSequence::dump() const {
522 raw_ostream &OS = llvm::errs();
523 if (isStdInitializerListElement())
524 OS << "Worst std::initializer_list element conversion: ";
525 switch (ConversionKind) {
526 case StandardConversion:
527 OS << "Standard conversion: ";
528 Standard.dump();
529 break;
530 case UserDefinedConversion:
531 OS << "User-defined conversion: ";
532 UserDefined.dump();
533 break;
534 case EllipsisConversion:
535 OS << "Ellipsis conversion";
536 break;
537 case AmbiguousConversion:
538 OS << "Ambiguous conversion";
539 break;
540 case BadConversion:
541 OS << "Bad conversion";
542 break;
543 }
544
545 OS << "\n";
546}
547
548void AmbiguousConversionSequence::construct() {
549 new (&conversions()) ConversionSet();
550}
551
552void AmbiguousConversionSequence::destruct() {
553 conversions().~ConversionSet();
554}
555
556void
557AmbiguousConversionSequence::copyFrom(const AmbiguousConversionSequence &O) {
558 FromTypePtr = O.FromTypePtr;
559 ToTypePtr = O.ToTypePtr;
560 new (&conversions()) ConversionSet(O.conversions());
561}
562
563namespace {
564 // Structure used by DeductionFailureInfo to store
565 // template argument information.
566 struct DFIArguments {
567 TemplateArgument FirstArg;
568 TemplateArgument SecondArg;
569 };
570 // Structure used by DeductionFailureInfo to store
571 // template parameter and template argument information.
572 struct DFIParamWithArguments : DFIArguments {
573 TemplateParameter Param;
574 };
575 // Structure used by DeductionFailureInfo to store template argument
576 // information and the index of the problematic call argument.
577 struct DFIDeducedMismatchArgs : DFIArguments {
578 TemplateArgumentList *TemplateArgs;
579 unsigned CallArgIndex;
580 };
581}
582
583/// \brief Convert from Sema's representation of template deduction information
584/// to the form used in overload-candidate information.
585DeductionFailureInfo
586clang::MakeDeductionFailureInfo(ASTContext &Context,
587 Sema::TemplateDeductionResult TDK,
588 TemplateDeductionInfo &Info) {
589 DeductionFailureInfo Result;
590 Result.Result = static_cast<unsigned>(TDK);
591 Result.HasDiagnostic = false;
592 switch (TDK) {
593 case Sema::TDK_Invalid:
594 case Sema::TDK_InstantiationDepth:
595 case Sema::TDK_TooManyArguments:
596 case Sema::TDK_TooFewArguments:
597 case Sema::TDK_MiscellaneousDeductionFailure:
598 case Sema::TDK_CUDATargetMismatch:
599 Result.Data = nullptr;
600 break;
601
602 case Sema::TDK_Incomplete:
603 case Sema::TDK_InvalidExplicitArguments:
604 Result.Data = Info.Param.getOpaqueValue();
605 break;
606
607 case Sema::TDK_DeducedMismatch:
608 case Sema::TDK_DeducedMismatchNested: {
609 // FIXME: Should allocate from normal heap so that we can free this later.
610 auto *Saved = new (Context) DFIDeducedMismatchArgs;
611 Saved->FirstArg = Info.FirstArg;
612 Saved->SecondArg = Info.SecondArg;
613 Saved->TemplateArgs = Info.take();
614 Saved->CallArgIndex = Info.CallArgIndex;
615 Result.Data = Saved;
616 break;
617 }
618
619 case Sema::TDK_NonDeducedMismatch: {
620 // FIXME: Should allocate from normal heap so that we can free this later.
621 DFIArguments *Saved = new (Context) DFIArguments;
622 Saved->FirstArg = Info.FirstArg;
623 Saved->SecondArg = Info.SecondArg;
624 Result.Data = Saved;
625 break;
626 }
627
628 case Sema::TDK_Inconsistent:
629 case Sema::TDK_Underqualified: {
630 // FIXME: Should allocate from normal heap so that we can free this later.
631 DFIParamWithArguments *Saved = new (Context) DFIParamWithArguments;
632 Saved->Param = Info.Param;
633 Saved->FirstArg = Info.FirstArg;
634 Saved->SecondArg = Info.SecondArg;
635 Result.Data = Saved;
636 break;
637 }
638
639 case Sema::TDK_SubstitutionFailure:
640 Result.Data = Info.take();
641 if (Info.hasSFINAEDiagnostic()) {
642 PartialDiagnosticAt *Diag = new (Result.Diagnostic) PartialDiagnosticAt(
643 SourceLocation(), PartialDiagnostic::NullDiagnostic());
644 Info.takeSFINAEDiagnostic(*Diag);
645 Result.HasDiagnostic = true;
646 }
647 break;
648
649 case Sema::TDK_Success:
650 case Sema::TDK_NonDependentConversionFailure:
651 llvm_unreachable("not a deduction failure")::llvm::llvm_unreachable_internal("not a deduction failure", "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303373/tools/clang/lib/Sema/SemaOverload.cpp"
, 651)
;
652 }
653
654 return Result;
655}
656
657void DeductionFailureInfo::Destroy() {
658 switch (static_cast<Sema::TemplateDeductionResult>(Result)) {
659 case Sema::TDK_Success:
660 case Sema::TDK_Invalid:
661 case Sema::TDK_InstantiationDepth:
662 case Sema::TDK_Incomplete:
663 case Sema::TDK_TooManyArguments:
664 case Sema::TDK_TooFewArguments:
665 case Sema::TDK_InvalidExplicitArguments:
666 case Sema::TDK_CUDATargetMismatch:
667 case Sema::TDK_NonDependentConversionFailure:
668 break;
669
670 case Sema::TDK_Inconsistent:
671 case Sema::TDK_Underqualified:
672 case Sema::TDK_DeducedMismatch:
673 case Sema::TDK_DeducedMismatchNested:
674 case Sema::TDK_NonDeducedMismatch:
675 // FIXME: Destroy the data?
676 Data = nullptr;
677 break;
678
679 case Sema::TDK_SubstitutionFailure:
680 // FIXME: Destroy the template argument list?
681 Data = nullptr;
682 if (PartialDiagnosticAt *Diag = getSFINAEDiagnostic()) {
683 Diag->~PartialDiagnosticAt();
684 HasDiagnostic = false;
685 }
686 break;
687
688 // Unhandled
689 case Sema::TDK_MiscellaneousDeductionFailure:
690 break;
691 }
692}
693
694PartialDiagnosticAt *DeductionFailureInfo::getSFINAEDiagnostic() {
695 if (HasDiagnostic)
696 return static_cast<PartialDiagnosticAt*>(static_cast<void*>(Diagnostic));
697 return nullptr;
698}
699
700TemplateParameter DeductionFailureInfo::getTemplateParameter() {
701 switch (static_cast<Sema::TemplateDeductionResult>(Result)) {
702 case Sema::TDK_Success:
703 case Sema::TDK_Invalid:
704 case Sema::TDK_InstantiationDepth:
705 case Sema::TDK_TooManyArguments:
706 case Sema::TDK_TooFewArguments:
707 case Sema::TDK_SubstitutionFailure:
708 case Sema::TDK_DeducedMismatch:
709 case Sema::TDK_DeducedMismatchNested:
710 case Sema::TDK_NonDeducedMismatch:
711 case Sema::TDK_CUDATargetMismatch:
712 case Sema::TDK_NonDependentConversionFailure:
713 return TemplateParameter();
714
715 case Sema::TDK_Incomplete:
716 case Sema::TDK_InvalidExplicitArguments:
717 return TemplateParameter::getFromOpaqueValue(Data);
718
719 case Sema::TDK_Inconsistent:
720 case Sema::TDK_Underqualified:
721 return static_cast<DFIParamWithArguments*>(Data)->Param;
722
723 // Unhandled
724 case Sema::TDK_MiscellaneousDeductionFailure:
725 break;
726 }
727
728 return TemplateParameter();
729}
730
731TemplateArgumentList *DeductionFailureInfo::getTemplateArgumentList() {
732 switch (static_cast<Sema::TemplateDeductionResult>(Result)) {
733 case Sema::TDK_Success:
734 case Sema::TDK_Invalid:
735 case Sema::TDK_InstantiationDepth:
736 case Sema::TDK_TooManyArguments:
737 case Sema::TDK_TooFewArguments:
738 case Sema::TDK_Incomplete:
739 case Sema::TDK_InvalidExplicitArguments:
740 case Sema::TDK_Inconsistent:
741 case Sema::TDK_Underqualified:
742 case Sema::TDK_NonDeducedMismatch:
743 case Sema::TDK_CUDATargetMismatch:
744 case Sema::TDK_NonDependentConversionFailure:
745 return nullptr;
746
747 case Sema::TDK_DeducedMismatch:
748 case Sema::TDK_DeducedMismatchNested:
749 return static_cast<DFIDeducedMismatchArgs*>(Data)->TemplateArgs;
750
751 case Sema::TDK_SubstitutionFailure:
752 return static_cast<TemplateArgumentList*>(Data);
753
754 // Unhandled
755 case Sema::TDK_MiscellaneousDeductionFailure:
756 break;
757 }
758
759 return nullptr;
760}
761
762const TemplateArgument *DeductionFailureInfo::getFirstArg() {
763 switch (static_cast<Sema::TemplateDeductionResult>(Result)) {
764 case Sema::TDK_Success:
765 case Sema::TDK_Invalid:
766 case Sema::TDK_InstantiationDepth:
767 case Sema::TDK_Incomplete:
768 case Sema::TDK_TooManyArguments:
769 case Sema::TDK_TooFewArguments:
770 case Sema::TDK_InvalidExplicitArguments:
771 case Sema::TDK_SubstitutionFailure:
772 case Sema::TDK_CUDATargetMismatch:
773 case Sema::TDK_NonDependentConversionFailure:
774 return nullptr;
775
776 case Sema::TDK_Inconsistent:
777 case Sema::TDK_Underqualified:
778 case Sema::TDK_DeducedMismatch:
779 case Sema::TDK_DeducedMismatchNested:
780 case Sema::TDK_NonDeducedMismatch:
781 return &static_cast<DFIArguments*>(Data)->FirstArg;
782
783 // Unhandled
784 case Sema::TDK_MiscellaneousDeductionFailure:
785 break;
786 }
787
788 return nullptr;
789}
790
791const TemplateArgument *DeductionFailureInfo::getSecondArg() {
792 switch (static_cast<Sema::TemplateDeductionResult>(Result)) {
793 case Sema::TDK_Success:
794 case Sema::TDK_Invalid:
795 case Sema::TDK_InstantiationDepth:
796 case Sema::TDK_Incomplete:
797 case Sema::TDK_TooManyArguments:
798 case Sema::TDK_TooFewArguments:
799 case Sema::TDK_InvalidExplicitArguments:
800 case Sema::TDK_SubstitutionFailure:
801 case Sema::TDK_CUDATargetMismatch:
802 case Sema::TDK_NonDependentConversionFailure:
803 return nullptr;
804
805 case Sema::TDK_Inconsistent:
806 case Sema::TDK_Underqualified:
807 case Sema::TDK_DeducedMismatch:
808 case Sema::TDK_DeducedMismatchNested:
809 case Sema::TDK_NonDeducedMismatch:
810 return &static_cast<DFIArguments*>(Data)->SecondArg;
811
812 // Unhandled
813 case Sema::TDK_MiscellaneousDeductionFailure:
814 break;
815 }
816
817 return nullptr;
818}
819
820llvm::Optional<unsigned> DeductionFailureInfo::getCallArgIndex() {
821 switch (static_cast<Sema::TemplateDeductionResult>(Result)) {
822 case Sema::TDK_DeducedMismatch:
823 case Sema::TDK_DeducedMismatchNested:
824 return static_cast<DFIDeducedMismatchArgs*>(Data)->CallArgIndex;
825
826 default:
827 return llvm::None;
828 }
829}
830
831void OverloadCandidateSet::destroyCandidates() {
832 for (iterator i = begin(), e = end(); i != e; ++i) {
833 for (auto &C : i->Conversions)
834 C.~ImplicitConversionSequence();
835 if (!i->Viable && i->FailureKind == ovl_fail_bad_deduction)
836 i->DeductionFailure.Destroy();
837 }
838}
839
840void OverloadCandidateSet::clear() {
841 destroyCandidates();
842 SlabAllocator.Reset();
843 NumInlineBytesUsed = 0;
844 Candidates.clear();
845 Functions.clear();
846}
847
848namespace {
849 class UnbridgedCastsSet {
850 struct Entry {
851 Expr **Addr;
852 Expr *Saved;
853 };
854 SmallVector<Entry, 2> Entries;
855
856 public:
857 void save(Sema &S, Expr *&E) {
858 assert(E->hasPlaceholderType(BuiltinType::ARCUnbridgedCast))((E->hasPlaceholderType(BuiltinType::ARCUnbridgedCast)) ? static_cast
<void> (0) : __assert_fail ("E->hasPlaceholderType(BuiltinType::ARCUnbridgedCast)"
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303373/tools/clang/lib/Sema/SemaOverload.cpp"
, 858, __PRETTY_FUNCTION__))
;
859 Entry entry = { &E, E };
860 Entries.push_back(entry);
861 E = S.stripARCUnbridgedCast(E);
862 }
863
864 void restore() {
865 for (SmallVectorImpl<Entry>::iterator
866 i = Entries.begin(), e = Entries.end(); i != e; ++i)
867 *i->Addr = i->Saved;
868 }
869 };
870}
871
872/// checkPlaceholderForOverload - Do any interesting placeholder-like
873/// preprocessing on the given expression.
874///
875/// \param unbridgedCasts a collection to which to add unbridged casts;
876/// without this, they will be immediately diagnosed as errors
877///
878/// Return true on unrecoverable error.
879static bool
880checkPlaceholderForOverload(Sema &S, Expr *&E,
881 UnbridgedCastsSet *unbridgedCasts = nullptr) {
882 if (const BuiltinType *placeholder = E->getType()->getAsPlaceholderType()) {
883 // We can't handle overloaded expressions here because overload
884 // resolution might reasonably tweak them.
885 if (placeholder->getKind() == BuiltinType::Overload) return false;
886
887 // If the context potentially accepts unbridged ARC casts, strip
888 // the unbridged cast and add it to the collection for later restoration.
889 if (placeholder->getKind() == BuiltinType::ARCUnbridgedCast &&
890 unbridgedCasts) {
891 unbridgedCasts->save(S, E);
892 return false;
893 }
894
895 // Go ahead and check everything else.
896 ExprResult result = S.CheckPlaceholderExpr(E);
897 if (result.isInvalid())
898 return true;
899
900 E = result.get();
901 return false;
902 }
903
904 // Nothing to do.
905 return false;
906}
907
908/// checkArgPlaceholdersForOverload - Check a set of call operands for
909/// placeholders.
910static bool checkArgPlaceholdersForOverload(Sema &S,
911 MultiExprArg Args,
912 UnbridgedCastsSet &unbridged) {
913 for (unsigned i = 0, e = Args.size(); i != e; ++i)
914 if (checkPlaceholderForOverload(S, Args[i], &unbridged))
915 return true;
916
917 return false;
918}
919
920/// Determine whether the given New declaration is an overload of the
921/// declarations in Old. This routine returns Ovl_Match or Ovl_NonFunction if
922/// New and Old cannot be overloaded, e.g., if New has the same signature as
923/// some function in Old (C++ 1.3.10) or if the Old declarations aren't
924/// functions (or function templates) at all. When it does return Ovl_Match or
925/// Ovl_NonFunction, MatchedDecl will point to the decl that New cannot be
926/// overloaded with. This decl may be a UsingShadowDecl on top of the underlying
927/// declaration.
928///
929/// Example: Given the following input:
930///
931/// void f(int, float); // #1
932/// void f(int, int); // #2
933/// int f(int, int); // #3
934///
935/// When we process #1, there is no previous declaration of "f", so IsOverload
936/// will not be used.
937///
938/// When we process #2, Old contains only the FunctionDecl for #1. By comparing
939/// the parameter types, we see that #1 and #2 are overloaded (since they have
940/// different signatures), so this routine returns Ovl_Overload; MatchedDecl is
941/// unchanged.
942///
943/// When we process #3, Old is an overload set containing #1 and #2. We compare
944/// the signatures of #3 to #1 (they're overloaded, so we do nothing) and then
945/// #3 to #2. Since the signatures of #3 and #2 are identical (return types of
946/// functions are not part of the signature), IsOverload returns Ovl_Match and
947/// MatchedDecl will be set to point to the FunctionDecl for #2.
948///
949/// 'NewIsUsingShadowDecl' indicates that 'New' is being introduced into a class
950/// by a using declaration. The rules for whether to hide shadow declarations
951/// ignore some properties which otherwise figure into a function template's
952/// signature.
953Sema::OverloadKind
954Sema::CheckOverload(Scope *S, FunctionDecl *New, const LookupResult &Old,
955 NamedDecl *&Match, bool NewIsUsingDecl) {
956 for (LookupResult::iterator I = Old.begin(), E = Old.end();
957 I != E; ++I) {
958 NamedDecl *OldD = *I;
959
960 bool OldIsUsingDecl = false;
961 if (isa<UsingShadowDecl>(OldD)) {
962 OldIsUsingDecl = true;
963
964 // We can always introduce two using declarations into the same
965 // context, even if they have identical signatures.
966 if (NewIsUsingDecl) continue;
967
968 OldD = cast<UsingShadowDecl>(OldD)->getTargetDecl();
969 }
970
971 // A using-declaration does not conflict with another declaration
972 // if one of them is hidden.
973 if ((OldIsUsingDecl || NewIsUsingDecl) && !isVisible(*I))
974 continue;
975
976 // If either declaration was introduced by a using declaration,
977 // we'll need to use slightly different rules for matching.
978 // Essentially, these rules are the normal rules, except that
979 // function templates hide function templates with different
980 // return types or template parameter lists.
981 bool UseMemberUsingDeclRules =
982 (OldIsUsingDecl || NewIsUsingDecl) && CurContext->isRecord() &&
983 !New->getFriendObjectKind();
984
985 if (FunctionDecl *OldF = OldD->getAsFunction()) {
986 if (!IsOverload(New, OldF, UseMemberUsingDeclRules)) {
987 if (UseMemberUsingDeclRules && OldIsUsingDecl) {
988 HideUsingShadowDecl(S, cast<UsingShadowDecl>(*I));
989 continue;
990 }
991
992 if (!isa<FunctionTemplateDecl>(OldD) &&
993 !shouldLinkPossiblyHiddenDecl(*I, New))
994 continue;
995
996 Match = *I;
997 return Ovl_Match;
998 }
999 } else if (isa<UsingDecl>(OldD) || isa<UsingPackDecl>(OldD)) {
1000 // We can overload with these, which can show up when doing
1001 // redeclaration checks for UsingDecls.
1002 assert(Old.getLookupKind() == LookupUsingDeclName)((Old.getLookupKind() == LookupUsingDeclName) ? static_cast<
void> (0) : __assert_fail ("Old.getLookupKind() == LookupUsingDeclName"
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303373/tools/clang/lib/Sema/SemaOverload.cpp"
, 1002, __PRETTY_FUNCTION__))
;
1003 } else if (isa<TagDecl>(OldD)) {
1004 // We can always overload with tags by hiding them.
1005 } else if (auto *UUD = dyn_cast<UnresolvedUsingValueDecl>(OldD)) {
1006 // Optimistically assume that an unresolved using decl will
1007 // overload; if it doesn't, we'll have to diagnose during
1008 // template instantiation.
1009 //
1010 // Exception: if the scope is dependent and this is not a class
1011 // member, the using declaration can only introduce an enumerator.
1012 if (UUD->getQualifier()->isDependent() && !UUD->isCXXClassMember()) {
1013 Match = *I;
1014 return Ovl_NonFunction;
1015 }
1016 } else {
1017 // (C++ 13p1):
1018 // Only function declarations can be overloaded; object and type
1019 // declarations cannot be overloaded.
1020 Match = *I;
1021 return Ovl_NonFunction;
1022 }
1023 }
1024
1025 return Ovl_Overload;
1026}
1027
1028bool Sema::IsOverload(FunctionDecl *New, FunctionDecl *Old,
1029 bool UseMemberUsingDeclRules, bool ConsiderCudaAttrs) {
1030 // C++ [basic.start.main]p2: This function shall not be overloaded.
1031 if (New->isMain())
1032 return false;
1033
1034 // MSVCRT user defined entry points cannot be overloaded.
1035 if (New->isMSVCRTEntryPoint())
1036 return false;
1037
1038 FunctionTemplateDecl *OldTemplate = Old->getDescribedFunctionTemplate();
1039 FunctionTemplateDecl *NewTemplate = New->getDescribedFunctionTemplate();
1040
1041 // C++ [temp.fct]p2:
1042 // A function template can be overloaded with other function templates
1043 // and with normal (non-template) functions.
1044 if ((OldTemplate == nullptr) != (NewTemplate == nullptr))
1045 return true;
1046
1047 // Is the function New an overload of the function Old?
1048 QualType OldQType = Context.getCanonicalType(Old->getType());
1049 QualType NewQType = Context.getCanonicalType(New->getType());
1050
1051 // Compare the signatures (C++ 1.3.10) of the two functions to
1052 // determine whether they are overloads. If we find any mismatch
1053 // in the signature, they are overloads.
1054
1055 // If either of these functions is a K&R-style function (no
1056 // prototype), then we consider them to have matching signatures.
1057 if (isa<FunctionNoProtoType>(OldQType.getTypePtr()) ||
1058 isa<FunctionNoProtoType>(NewQType.getTypePtr()))
1059 return false;
1060
1061 const FunctionProtoType *OldType = cast<FunctionProtoType>(OldQType);
1062 const FunctionProtoType *NewType = cast<FunctionProtoType>(NewQType);
1063
1064 // The signature of a function includes the types of its
1065 // parameters (C++ 1.3.10), which includes the presence or absence
1066 // of the ellipsis; see C++ DR 357).
1067 if (OldQType != NewQType &&
1068 (OldType->getNumParams() != NewType->getNumParams() ||
1069 OldType->isVariadic() != NewType->isVariadic() ||
1070 !FunctionParamTypesAreEqual(OldType, NewType)))
1071 return true;
1072
1073 // C++ [temp.over.link]p4:
1074 // The signature of a function template consists of its function
1075 // signature, its return type and its template parameter list. The names
1076 // of the template parameters are significant only for establishing the
1077 // relationship between the template parameters and the rest of the
1078 // signature.
1079 //
1080 // We check the return type and template parameter lists for function
1081 // templates first; the remaining checks follow.
1082 //
1083 // However, we don't consider either of these when deciding whether
1084 // a member introduced by a shadow declaration is hidden.
1085 if (!UseMemberUsingDeclRules && NewTemplate &&
1086 (!TemplateParameterListsAreEqual(NewTemplate->getTemplateParameters(),
1087 OldTemplate->getTemplateParameters(),
1088 false, TPL_TemplateMatch) ||
1089 OldType->getReturnType() != NewType->getReturnType()))
1090 return true;
1091
1092 // If the function is a class member, its signature includes the
1093 // cv-qualifiers (if any) and ref-qualifier (if any) on the function itself.
1094 //
1095 // As part of this, also check whether one of the member functions
1096 // is static, in which case they are not overloads (C++
1097 // 13.1p2). While not part of the definition of the signature,
1098 // this check is important to determine whether these functions
1099 // can be overloaded.
1100 CXXMethodDecl *OldMethod = dyn_cast<CXXMethodDecl>(Old);
1101 CXXMethodDecl *NewMethod = dyn_cast<CXXMethodDecl>(New);
1102 if (OldMethod && NewMethod &&
1103 !OldMethod->isStatic() && !NewMethod->isStatic()) {
1104 if (OldMethod->getRefQualifier() != NewMethod->getRefQualifier()) {
1105 if (!UseMemberUsingDeclRules &&
1106 (OldMethod->getRefQualifier() == RQ_None ||
1107 NewMethod->getRefQualifier() == RQ_None)) {
1108 // C++0x [over.load]p2:
1109 // - Member function declarations with the same name and the same
1110 // parameter-type-list as well as member function template
1111 // declarations with the same name, the same parameter-type-list, and
1112 // the same template parameter lists cannot be overloaded if any of
1113 // them, but not all, have a ref-qualifier (8.3.5).
1114 Diag(NewMethod->getLocation(), diag::err_ref_qualifier_overload)
1115 << NewMethod->getRefQualifier() << OldMethod->getRefQualifier();
1116 Diag(OldMethod->getLocation(), diag::note_previous_declaration);
1117 }
1118 return true;
1119 }
1120
1121 // We may not have applied the implicit const for a constexpr member
1122 // function yet (because we haven't yet resolved whether this is a static
1123 // or non-static member function). Add it now, on the assumption that this
1124 // is a redeclaration of OldMethod.
1125 unsigned OldQuals = OldMethod->getTypeQualifiers();
1126 unsigned NewQuals = NewMethod->getTypeQualifiers();
1127 if (!getLangOpts().CPlusPlus14 && NewMethod->isConstexpr() &&
1128 !isa<CXXConstructorDecl>(NewMethod))
1129 NewQuals |= Qualifiers::Const;
1130
1131 // We do not allow overloading based off of '__restrict'.
1132 OldQuals &= ~Qualifiers::Restrict;
1133 NewQuals &= ~Qualifiers::Restrict;
1134 if (OldQuals != NewQuals)
1135 return true;
1136 }
1137
1138 // Though pass_object_size is placed on parameters and takes an argument, we
1139 // consider it to be a function-level modifier for the sake of function
1140 // identity. Either the function has one or more parameters with
1141 // pass_object_size or it doesn't.
1142 if (functionHasPassObjectSizeParams(New) !=
1143 functionHasPassObjectSizeParams(Old))
1144 return true;
1145
1146 // enable_if attributes are an order-sensitive part of the signature.
1147 for (specific_attr_iterator<EnableIfAttr>
1148 NewI = New->specific_attr_begin<EnableIfAttr>(),
1149 NewE = New->specific_attr_end<EnableIfAttr>(),
1150 OldI = Old->specific_attr_begin<EnableIfAttr>(),
1151 OldE = Old->specific_attr_end<EnableIfAttr>();
1152 NewI != NewE || OldI != OldE; ++NewI, ++OldI) {
1153 if (NewI == NewE || OldI == OldE)
1154 return true;
1155 llvm::FoldingSetNodeID NewID, OldID;
1156 NewI->getCond()->Profile(NewID, Context, true);
1157 OldI->getCond()->Profile(OldID, Context, true);
1158 if (NewID != OldID)
1159 return true;
1160 }
1161
1162 if (getLangOpts().CUDA && ConsiderCudaAttrs) {
1163 // Don't allow overloading of destructors. (In theory we could, but it
1164 // would be a giant change to clang.)
1165 if (isa<CXXDestructorDecl>(New))
1166 return false;
1167
1168 CUDAFunctionTarget NewTarget = IdentifyCUDATarget(New),
1169 OldTarget = IdentifyCUDATarget(Old);
1170 if (NewTarget == CFT_InvalidTarget)
1171 return false;
1172
1173 assert((OldTarget != CFT_InvalidTarget) && "Unexpected invalid target.")(((OldTarget != CFT_InvalidTarget) && "Unexpected invalid target."
) ? static_cast<void> (0) : __assert_fail ("(OldTarget != CFT_InvalidTarget) && \"Unexpected invalid target.\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303373/tools/clang/lib/Sema/SemaOverload.cpp"
, 1173, __PRETTY_FUNCTION__))
;
1174
1175 // Allow overloading of functions with same signature and different CUDA
1176 // target attributes.
1177 return NewTarget != OldTarget;
1178 }
1179
1180 // The signatures match; this is not an overload.
1181 return false;
1182}
1183
1184/// \brief Checks availability of the function depending on the current
1185/// function context. Inside an unavailable function, unavailability is ignored.
1186///
1187/// \returns true if \arg FD is unavailable and current context is inside
1188/// an available function, false otherwise.
1189bool Sema::isFunctionConsideredUnavailable(FunctionDecl *FD) {
1190 if (!FD->isUnavailable())
1191 return false;
1192
1193 // Walk up the context of the caller.
1194 Decl *C = cast<Decl>(CurContext);
1195 do {
1196 if (C->isUnavailable())
1197 return false;
1198 } while ((C = cast_or_null<Decl>(C->getDeclContext())));
1199 return true;
1200}
1201
1202/// \brief Tries a user-defined conversion from From to ToType.
1203///
1204/// Produces an implicit conversion sequence for when a standard conversion
1205/// is not an option. See TryImplicitConversion for more information.
1206static ImplicitConversionSequence
1207TryUserDefinedConversion(Sema &S, Expr *From, QualType ToType,
1208 bool SuppressUserConversions,
1209 bool AllowExplicit,
1210 bool InOverloadResolution,
1211 bool CStyle,
1212 bool AllowObjCWritebackConversion,
1213 bool AllowObjCConversionOnExplicit) {
1214 ImplicitConversionSequence ICS;
1215
1216 if (SuppressUserConversions) {
1217 // We're not in the case above, so there is no conversion that
1218 // we can perform.
1219 ICS.setBad(BadConversionSequence::no_conversion, From, ToType);
1220 return ICS;
1221 }
1222
1223 // Attempt user-defined conversion.
1224 OverloadCandidateSet Conversions(From->getExprLoc(),
1225 OverloadCandidateSet::CSK_Normal);
1226 switch (IsUserDefinedConversion(S, From, ToType, ICS.UserDefined,
1227 Conversions, AllowExplicit,
1228 AllowObjCConversionOnExplicit)) {
1229 case OR_Success:
1230 case OR_Deleted:
1231 ICS.setUserDefined();
1232 // C++ [over.ics.user]p4:
1233 // A conversion of an expression of class type to the same class
1234 // type is given Exact Match rank, and a conversion of an
1235 // expression of class type to a base class of that type is
1236 // given Conversion rank, in spite of the fact that a copy
1237 // constructor (i.e., a user-defined conversion function) is
1238 // called for those cases.
1239 if (CXXConstructorDecl *Constructor
1240 = dyn_cast<CXXConstructorDecl>(ICS.UserDefined.ConversionFunction)) {
1241 QualType FromCanon
1242 = S.Context.getCanonicalType(From->getType().getUnqualifiedType());
1243 QualType ToCanon
1244 = S.Context.getCanonicalType(ToType).getUnqualifiedType();
1245 if (Constructor->isCopyConstructor() &&
1246 (FromCanon == ToCanon ||
1247 S.IsDerivedFrom(From->getLocStart(), FromCanon, ToCanon))) {
1248 // Turn this into a "standard" conversion sequence, so that it
1249 // gets ranked with standard conversion sequences.
1250 DeclAccessPair Found = ICS.UserDefined.FoundConversionFunction;
1251 ICS.setStandard();
1252 ICS.Standard.setAsIdentityConversion();
1253 ICS.Standard.setFromType(From->getType());
1254 ICS.Standard.setAllToTypes(ToType);
1255 ICS.Standard.CopyConstructor = Constructor;
1256 ICS.Standard.FoundCopyConstructor = Found;
1257 if (ToCanon != FromCanon)
1258 ICS.Standard.Second = ICK_Derived_To_Base;
1259 }
1260 }
1261 break;
1262
1263 case OR_Ambiguous:
1264 ICS.setAmbiguous();
1265 ICS.Ambiguous.setFromType(From->getType());
1266 ICS.Ambiguous.setToType(ToType);
1267 for (OverloadCandidateSet::iterator Cand = Conversions.begin();
1268 Cand != Conversions.end(); ++Cand)
1269 if (Cand->Viable)
1270 ICS.Ambiguous.addConversion(Cand->FoundDecl, Cand->Function);
1271 break;
1272
1273 // Fall through.
1274 case OR_No_Viable_Function:
1275 ICS.setBad(BadConversionSequence::no_conversion, From, ToType);
1276 break;
1277 }
1278
1279 return ICS;
1280}
1281
1282/// TryImplicitConversion - Attempt to perform an implicit conversion
1283/// from the given expression (Expr) to the given type (ToType). This
1284/// function returns an implicit conversion sequence that can be used
1285/// to perform the initialization. Given
1286///
1287/// void f(float f);
1288/// void g(int i) { f(i); }
1289///
1290/// this routine would produce an implicit conversion sequence to
1291/// describe the initialization of f from i, which will be a standard
1292/// conversion sequence containing an lvalue-to-rvalue conversion (C++
1293/// 4.1) followed by a floating-integral conversion (C++ 4.9).
1294//
1295/// Note that this routine only determines how the conversion can be
1296/// performed; it does not actually perform the conversion. As such,
1297/// it will not produce any diagnostics if no conversion is available,
1298/// but will instead return an implicit conversion sequence of kind
1299/// "BadConversion".
1300///
1301/// If @p SuppressUserConversions, then user-defined conversions are
1302/// not permitted.
1303/// If @p AllowExplicit, then explicit user-defined conversions are
1304/// permitted.
1305///
1306/// \param AllowObjCWritebackConversion Whether we allow the Objective-C
1307/// writeback conversion, which allows __autoreleasing id* parameters to
1308/// be initialized with __strong id* or __weak id* arguments.
1309static ImplicitConversionSequence
1310TryImplicitConversion(Sema &S, Expr *From, QualType ToType,
1311 bool SuppressUserConversions,
1312 bool AllowExplicit,
1313 bool InOverloadResolution,
1314 bool CStyle,
1315 bool AllowObjCWritebackConversion,
1316 bool AllowObjCConversionOnExplicit) {
1317 ImplicitConversionSequence ICS;
1318 if (IsStandardConversion(S, From, ToType, InOverloadResolution,
1319 ICS.Standard, CStyle, AllowObjCWritebackConversion)){
1320 ICS.setStandard();
1321 return ICS;
1322 }
1323
1324 if (!S.getLangOpts().CPlusPlus) {
1325 ICS.setBad(BadConversionSequence::no_conversion, From, ToType);
1326 return ICS;
1327 }
1328
1329 // C++ [over.ics.user]p4:
1330 // A conversion of an expression of class type to the same class
1331 // type is given Exact Match rank, and a conversion of an
1332 // expression of class type to a base class of that type is
1333 // given Conversion rank, in spite of the fact that a copy/move
1334 // constructor (i.e., a user-defined conversion function) is
1335 // called for those cases.
1336 QualType FromType = From->getType();
1337 if (ToType->getAs<RecordType>() && FromType->getAs<RecordType>() &&
1338 (S.Context.hasSameUnqualifiedType(FromType, ToType) ||
1339 S.IsDerivedFrom(From->getLocStart(), FromType, ToType))) {
1340 ICS.setStandard();
1341 ICS.Standard.setAsIdentityConversion();
1342 ICS.Standard.setFromType(FromType);
1343 ICS.Standard.setAllToTypes(ToType);
1344
1345 // We don't actually check at this point whether there is a valid
1346 // copy/move constructor, since overloading just assumes that it
1347 // exists. When we actually perform initialization, we'll find the
1348 // appropriate constructor to copy the returned object, if needed.
1349 ICS.Standard.CopyConstructor = nullptr;
1350
1351 // Determine whether this is considered a derived-to-base conversion.
1352 if (!S.Context.hasSameUnqualifiedType(FromType, ToType))
1353 ICS.Standard.Second = ICK_Derived_To_Base;
1354
1355 return ICS;
1356 }
1357
1358 return TryUserDefinedConversion(S, From, ToType, SuppressUserConversions,
1359 AllowExplicit, InOverloadResolution, CStyle,
1360 AllowObjCWritebackConversion,
1361 AllowObjCConversionOnExplicit);
1362}
1363
1364ImplicitConversionSequence
1365Sema::TryImplicitConversion(Expr *From, QualType ToType,
1366 bool SuppressUserConversions,
1367 bool AllowExplicit,
1368 bool InOverloadResolution,
1369 bool CStyle,
1370 bool AllowObjCWritebackConversion) {
1371 return ::TryImplicitConversion(*this, From, ToType,
1372 SuppressUserConversions, AllowExplicit,
1373 InOverloadResolution, CStyle,
1374 AllowObjCWritebackConversion,
1375 /*AllowObjCConversionOnExplicit=*/false);
1376}
1377
1378/// PerformImplicitConversion - Perform an implicit conversion of the
1379/// expression From to the type ToType. Returns the
1380/// converted expression. Flavor is the kind of conversion we're
1381/// performing, used in the error message. If @p AllowExplicit,
1382/// explicit user-defined conversions are permitted.
1383ExprResult
1384Sema::PerformImplicitConversion(Expr *From, QualType ToType,
1385 AssignmentAction Action, bool AllowExplicit) {
1386 ImplicitConversionSequence ICS;
1387 return PerformImplicitConversion(From, ToType, Action, AllowExplicit, ICS);
1388}
1389
1390ExprResult
1391Sema::PerformImplicitConversion(Expr *From, QualType ToType,
1392 AssignmentAction Action, bool AllowExplicit,
1393 ImplicitConversionSequence& ICS) {
1394 if (checkPlaceholderForOverload(*this, From))
1395 return ExprError();
1396
1397 // Objective-C ARC: Determine whether we will allow the writeback conversion.
1398 bool AllowObjCWritebackConversion
1399 = getLangOpts().ObjCAutoRefCount &&
1400 (Action == AA_Passing || Action == AA_Sending);
1401 if (getLangOpts().ObjC1)
1402 CheckObjCBridgeRelatedConversions(From->getLocStart(),
1403 ToType, From->getType(), From);
1404 ICS = ::TryImplicitConversion(*this, From, ToType,
1405 /*SuppressUserConversions=*/false,
1406 AllowExplicit,
1407 /*InOverloadResolution=*/false,
1408 /*CStyle=*/false,
1409 AllowObjCWritebackConversion,
1410 /*AllowObjCConversionOnExplicit=*/false);
1411 return PerformImplicitConversion(From, ToType, ICS, Action);
1412}
1413
1414/// \brief Determine whether the conversion from FromType to ToType is a valid
1415/// conversion that strips "noexcept" or "noreturn" off the nested function
1416/// type.
1417bool Sema::IsFunctionConversion(QualType FromType, QualType ToType,
1418 QualType &ResultTy) {
1419 if (Context.hasSameUnqualifiedType(FromType, ToType))
1420 return false;
1421
1422 // Permit the conversion F(t __attribute__((noreturn))) -> F(t)
1423 // or F(t noexcept) -> F(t)
1424 // where F adds one of the following at most once:
1425 // - a pointer
1426 // - a member pointer
1427 // - a block pointer
1428 // Changes here need matching changes in FindCompositePointerType.
1429 CanQualType CanTo = Context.getCanonicalType(ToType);
1430 CanQualType CanFrom = Context.getCanonicalType(FromType);
1431 Type::TypeClass TyClass = CanTo->getTypeClass();
1432 if (TyClass != CanFrom->getTypeClass()) return false;
1433 if (TyClass != Type::FunctionProto && TyClass != Type::FunctionNoProto) {
1434 if (TyClass == Type::Pointer) {
1435 CanTo = CanTo.getAs<PointerType>()->getPointeeType();
1436 CanFrom = CanFrom.getAs<PointerType>()->getPointeeType();
1437 } else if (TyClass == Type::BlockPointer) {
1438 CanTo = CanTo.getAs<BlockPointerType>()->getPointeeType();
1439 CanFrom = CanFrom.getAs<BlockPointerType>()->getPointeeType();
1440 } else if (TyClass == Type::MemberPointer) {
1441 auto ToMPT = CanTo.getAs<MemberPointerType>();
1442 auto FromMPT = CanFrom.getAs<MemberPointerType>();
1443 // A function pointer conversion cannot change the class of the function.
1444 if (ToMPT->getClass() != FromMPT->getClass())
1445 return false;
1446 CanTo = ToMPT->getPointeeType();
1447 CanFrom = FromMPT->getPointeeType();
1448 } else {
1449 return false;
1450 }
1451
1452 TyClass = CanTo->getTypeClass();
1453 if (TyClass != CanFrom->getTypeClass()) return false;
1454 if (TyClass != Type::FunctionProto && TyClass != Type::FunctionNoProto)
1455 return false;
1456 }
1457
1458 const auto *FromFn = cast<FunctionType>(CanFrom);
1459 FunctionType::ExtInfo FromEInfo = FromFn->getExtInfo();
1460
1461 const auto *ToFn = cast<FunctionType>(CanTo);
1462 FunctionType::ExtInfo ToEInfo = ToFn->getExtInfo();
1463
1464 bool Changed = false;
1465
1466 // Drop 'noreturn' if not present in target type.
1467 if (FromEInfo.getNoReturn() && !ToEInfo.getNoReturn()) {
1468 FromFn = Context.adjustFunctionType(FromFn, FromEInfo.withNoReturn(false));
1469 Changed = true;
1470 }
1471
1472 // Drop 'noexcept' if not present in target type.
1473 if (const auto *FromFPT = dyn_cast<FunctionProtoType>(FromFn)) {
1474 const auto *ToFPT = cast<FunctionProtoType>(ToFn);
1475 if (FromFPT->isNothrow(Context) && !ToFPT->isNothrow(Context)) {
1476 FromFn = cast<FunctionType>(
1477 Context.getFunctionType(FromFPT->getReturnType(),
1478 FromFPT->getParamTypes(),
1479 FromFPT->getExtProtoInfo().withExceptionSpec(
1480 FunctionProtoType::ExceptionSpecInfo()))
1481 .getTypePtr());
1482 Changed = true;
1483 }
1484 }
1485
1486 if (!Changed)
1487 return false;
1488
1489 assert(QualType(FromFn, 0).isCanonical())((QualType(FromFn, 0).isCanonical()) ? static_cast<void>
(0) : __assert_fail ("QualType(FromFn, 0).isCanonical()", "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303373/tools/clang/lib/Sema/SemaOverload.cpp"
, 1489, __PRETTY_FUNCTION__))
;
1490 if (QualType(FromFn, 0) != CanTo) return false;
1491
1492 ResultTy = ToType;
1493 return true;
1494}
1495
1496/// \brief Determine whether the conversion from FromType to ToType is a valid
1497/// vector conversion.
1498///
1499/// \param ICK Will be set to the vector conversion kind, if this is a vector
1500/// conversion.
1501static bool IsVectorConversion(Sema &S, QualType FromType,
1502 QualType ToType, ImplicitConversionKind &ICK) {
1503 // We need at least one of these types to be a vector type to have a vector
1504 // conversion.
1505 if (!ToType->isVectorType() && !FromType->isVectorType())
1506 return false;
1507
1508 // Identical types require no conversions.
1509 if (S.Context.hasSameUnqualifiedType(FromType, ToType))
1510 return false;
1511
1512 // There are no conversions between extended vector types, only identity.
1513 if (ToType->isExtVectorType()) {
1514 // There are no conversions between extended vector types other than the
1515 // identity conversion.
1516 if (FromType->isExtVectorType())
1517 return false;
1518
1519 // Vector splat from any arithmetic type to a vector.
1520 if (FromType->isArithmeticType()) {
1521 ICK = ICK_Vector_Splat;
1522 return true;
1523 }
1524 }
1525
1526 // We can perform the conversion between vector types in the following cases:
1527 // 1)vector types are equivalent AltiVec and GCC vector types
1528 // 2)lax vector conversions are permitted and the vector types are of the
1529 // same size
1530 if (ToType->isVectorType() && FromType->isVectorType()) {
1531 if (S.Context.areCompatibleVectorTypes(FromType, ToType) ||
1532 S.isLaxVectorConversion(FromType, ToType)) {
1533 ICK = ICK_Vector_Conversion;
1534 return true;
1535 }
1536 }
1537
1538 return false;
1539}
1540
1541static bool tryAtomicConversion(Sema &S, Expr *From, QualType ToType,
1542 bool InOverloadResolution,
1543 StandardConversionSequence &SCS,
1544 bool CStyle);
1545
1546/// IsStandardConversion - Determines whether there is a standard
1547/// conversion sequence (C++ [conv], C++ [over.ics.scs]) from the
1548/// expression From to the type ToType. Standard conversion sequences
1549/// only consider non-class types; for conversions that involve class
1550/// types, use TryImplicitConversion. If a conversion exists, SCS will
1551/// contain the standard conversion sequence required to perform this
1552/// conversion and this routine will return true. Otherwise, this
1553/// routine will return false and the value of SCS is unspecified.
1554static bool IsStandardConversion(Sema &S, Expr* From, QualType ToType,
1555 bool InOverloadResolution,
1556 StandardConversionSequence &SCS,
1557 bool CStyle,
1558 bool AllowObjCWritebackConversion) {
1559 QualType FromType = From->getType();
1560
1561 // Standard conversions (C++ [conv])
1562 SCS.setAsIdentityConversion();
1563 SCS.IncompatibleObjC = false;
1564 SCS.setFromType(FromType);
1565 SCS.CopyConstructor = nullptr;
1566
1567 // There are no standard conversions for class types in C++, so
1568 // abort early. When overloading in C, however, we do permit them.
1569 if (S.getLangOpts().CPlusPlus &&
1570 (FromType->isRecordType() || ToType->isRecordType()))
1571 return false;
1572
1573 // The first conversion can be an lvalue-to-rvalue conversion,
1574 // array-to-pointer conversion, or function-to-pointer conversion
1575 // (C++ 4p1).
1576
1577 if (FromType == S.Context.OverloadTy) {
1578 DeclAccessPair AccessPair;
1579 if (FunctionDecl *Fn
1580 = S.ResolveAddressOfOverloadedFunction(From, ToType, false,
1581 AccessPair)) {
1582 // We were able to resolve the address of the overloaded function,
1583 // so we can convert to the type of that function.
1584 FromType = Fn->getType();
1585 SCS.setFromType(FromType);
1586
1587 // we can sometimes resolve &foo<int> regardless of ToType, so check
1588 // if the type matches (identity) or we are converting to bool
1589 if (!S.Context.hasSameUnqualifiedType(
1590 S.ExtractUnqualifiedFunctionType(ToType), FromType)) {
1591 QualType resultTy;
1592 // if the function type matches except for [[noreturn]], it's ok
1593 if (!S.IsFunctionConversion(FromType,
1594 S.ExtractUnqualifiedFunctionType(ToType), resultTy))
1595 // otherwise, only a boolean conversion is standard
1596 if (!ToType->isBooleanType())
1597 return false;
1598 }
1599
1600 // Check if the "from" expression is taking the address of an overloaded
1601 // function and recompute the FromType accordingly. Take advantage of the
1602 // fact that non-static member functions *must* have such an address-of
1603 // expression.
1604 CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn);
1605 if (Method && !Method->isStatic()) {
1606 assert(isa<UnaryOperator>(From->IgnoreParens()) &&((isa<UnaryOperator>(From->IgnoreParens()) &&
"Non-unary operator on non-static member address") ? static_cast
<void> (0) : __assert_fail ("isa<UnaryOperator>(From->IgnoreParens()) && \"Non-unary operator on non-static member address\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303373/tools/clang/lib/Sema/SemaOverload.cpp"
, 1607, __PRETTY_FUNCTION__))
1607 "Non-unary operator on non-static member address")((isa<UnaryOperator>(From->IgnoreParens()) &&
"Non-unary operator on non-static member address") ? static_cast
<void> (0) : __assert_fail ("isa<UnaryOperator>(From->IgnoreParens()) && \"Non-unary operator on non-static member address\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303373/tools/clang/lib/Sema/SemaOverload.cpp"
, 1607, __PRETTY_FUNCTION__))
;
1608 assert(cast<UnaryOperator>(From->IgnoreParens())->getOpcode()((cast<UnaryOperator>(From->IgnoreParens())->getOpcode
() == UO_AddrOf && "Non-address-of operator on non-static member address"
) ? static_cast<void> (0) : __assert_fail ("cast<UnaryOperator>(From->IgnoreParens())->getOpcode() == UO_AddrOf && \"Non-address-of operator on non-static member address\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303373/tools/clang/lib/Sema/SemaOverload.cpp"
, 1610, __PRETTY_FUNCTION__))
1609 == UO_AddrOf &&((cast<UnaryOperator>(From->IgnoreParens())->getOpcode
() == UO_AddrOf && "Non-address-of operator on non-static member address"
) ? static_cast<void> (0) : __assert_fail ("cast<UnaryOperator>(From->IgnoreParens())->getOpcode() == UO_AddrOf && \"Non-address-of operator on non-static member address\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303373/tools/clang/lib/Sema/SemaOverload.cpp"
, 1610, __PRETTY_FUNCTION__))
1610 "Non-address-of operator on non-static member address")((cast<UnaryOperator>(From->IgnoreParens())->getOpcode
() == UO_AddrOf && "Non-address-of operator on non-static member address"
) ? static_cast<void> (0) : __assert_fail ("cast<UnaryOperator>(From->IgnoreParens())->getOpcode() == UO_AddrOf && \"Non-address-of operator on non-static member address\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303373/tools/clang/lib/Sema/SemaOverload.cpp"
, 1610, __PRETTY_FUNCTION__))
;
1611 const Type *ClassType
1612 = S.Context.getTypeDeclType(Method->getParent()).getTypePtr();
1613 FromType = S.Context.getMemberPointerType(FromType, ClassType);
1614 } else if (isa<UnaryOperator>(From->IgnoreParens())) {
1615 assert(cast<UnaryOperator>(From->IgnoreParens())->getOpcode() ==((cast<UnaryOperator>(From->IgnoreParens())->getOpcode
() == UO_AddrOf && "Non-address-of operator for overloaded function expression"
) ? static_cast<void> (0) : __assert_fail ("cast<UnaryOperator>(From->IgnoreParens())->getOpcode() == UO_AddrOf && \"Non-address-of operator for overloaded function expression\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303373/tools/clang/lib/Sema/SemaOverload.cpp"
, 1617, __PRETTY_FUNCTION__))
1616 UO_AddrOf &&((cast<UnaryOperator>(From->IgnoreParens())->getOpcode
() == UO_AddrOf && "Non-address-of operator for overloaded function expression"
) ? static_cast<void> (0) : __assert_fail ("cast<UnaryOperator>(From->IgnoreParens())->getOpcode() == UO_AddrOf && \"Non-address-of operator for overloaded function expression\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303373/tools/clang/lib/Sema/SemaOverload.cpp"
, 1617, __PRETTY_FUNCTION__))
1617 "Non-address-of operator for overloaded function expression")((cast<UnaryOperator>(From->IgnoreParens())->getOpcode
() == UO_AddrOf && "Non-address-of operator for overloaded function expression"
) ? static_cast<void> (0) : __assert_fail ("cast<UnaryOperator>(From->IgnoreParens())->getOpcode() == UO_AddrOf && \"Non-address-of operator for overloaded function expression\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303373/tools/clang/lib/Sema/SemaOverload.cpp"
, 1617, __PRETTY_FUNCTION__))
;
1618 FromType = S.Context.getPointerType(FromType);
1619 }
1620
1621 // Check that we've computed the proper type after overload resolution.
1622 // FIXME: FixOverloadedFunctionReference has side-effects; we shouldn't
1623 // be calling it from within an NDEBUG block.
1624 assert(S.Context.hasSameType(((S.Context.hasSameType( FromType, S.FixOverloadedFunctionReference
(From, AccessPair, Fn)->getType())) ? static_cast<void>
(0) : __assert_fail ("S.Context.hasSameType( FromType, S.FixOverloadedFunctionReference(From, AccessPair, Fn)->getType())"
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303373/tools/clang/lib/Sema/SemaOverload.cpp"
, 1626, __PRETTY_FUNCTION__))
1625 FromType,((S.Context.hasSameType( FromType, S.FixOverloadedFunctionReference
(From, AccessPair, Fn)->getType())) ? static_cast<void>
(0) : __assert_fail ("S.Context.hasSameType( FromType, S.FixOverloadedFunctionReference(From, AccessPair, Fn)->getType())"
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303373/tools/clang/lib/Sema/SemaOverload.cpp"
, 1626, __PRETTY_FUNCTION__))
1626 S.FixOverloadedFunctionReference(From, AccessPair, Fn)->getType()))((S.Context.hasSameType( FromType, S.FixOverloadedFunctionReference
(From, AccessPair, Fn)->getType())) ? static_cast<void>
(0) : __assert_fail ("S.Context.hasSameType( FromType, S.FixOverloadedFunctionReference(From, AccessPair, Fn)->getType())"
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303373/tools/clang/lib/Sema/SemaOverload.cpp"
, 1626, __PRETTY_FUNCTION__))
;
1627 } else {
1628 return false;
1629 }
1630 }
1631 // Lvalue-to-rvalue conversion (C++11 4.1):
1632 // A glvalue (3.10) of a non-function, non-array type T can
1633 // be converted to a prvalue.
1634 bool argIsLValue = From->isGLValue();
1635 if (argIsLValue &&
1636 !FromType->isFunctionType() && !FromType->isArrayType() &&
1637 S.Context.getCanonicalType(FromType) != S.Context.OverloadTy) {
1638 SCS.First = ICK_Lvalue_To_Rvalue;
1639
1640 // C11 6.3.2.1p2:
1641 // ... if the lvalue has atomic type, the value has the non-atomic version
1642 // of the type of the lvalue ...
1643 if (const AtomicType *Atomic = FromType->getAs<AtomicType>())
1644 FromType = Atomic->getValueType();
1645
1646 // If T is a non-class type, the type of the rvalue is the
1647 // cv-unqualified version of T. Otherwise, the type of the rvalue
1648 // is T (C++ 4.1p1). C++ can't get here with class types; in C, we
1649 // just strip the qualifiers because they don't matter.
1650 FromType = FromType.getUnqualifiedType();
1651 } else if (FromType->isArrayType()) {
1652 // Array-to-pointer conversion (C++ 4.2)
1653 SCS.First = ICK_Array_To_Pointer;
1654
1655 // An lvalue or rvalue of type "array of N T" or "array of unknown
1656 // bound of T" can be converted to an rvalue of type "pointer to
1657 // T" (C++ 4.2p1).
1658 FromType = S.Context.getArrayDecayedType(FromType);
1659
1660 if (S.IsStringLiteralToNonConstPointerConversion(From, ToType)) {
1661 // This conversion is deprecated in C++03 (D.4)
1662 SCS.DeprecatedStringLiteralToCharPtr = true;
1663
1664 // For the purpose of ranking in overload resolution
1665 // (13.3.3.1.1), this conversion is considered an
1666 // array-to-pointer conversion followed by a qualification
1667 // conversion (4.4). (C++ 4.2p2)
1668 SCS.Second = ICK_Identity;
1669 SCS.Third = ICK_Qualification;
1670 SCS.QualificationIncludesObjCLifetime = false;
1671 SCS.setAllToTypes(FromType);
1672 return true;
1673 }
1674 } else if (FromType->isFunctionType() && argIsLValue) {
1675 // Function-to-pointer conversion (C++ 4.3).
1676 SCS.First = ICK_Function_To_Pointer;
1677
1678 if (auto *DRE = dyn_cast<DeclRefExpr>(From->IgnoreParenCasts()))
1679 if (auto *FD = dyn_cast<FunctionDecl>(DRE->getDecl()))
1680 if (!S.checkAddressOfFunctionIsAvailable(FD))
1681 return false;
1682
1683 // An lvalue of function type T can be converted to an rvalue of
1684 // type "pointer to T." The result is a pointer to the
1685 // function. (C++ 4.3p1).
1686 FromType = S.Context.getPointerType(FromType);
1687 } else {
1688 // We don't require any conversions for the first step.
1689 SCS.First = ICK_Identity;
1690 }
1691 SCS.setToType(0, FromType);
1692
1693 // The second conversion can be an integral promotion, floating
1694 // point promotion, integral conversion, floating point conversion,
1695 // floating-integral conversion, pointer conversion,
1696 // pointer-to-member conversion, or boolean conversion (C++ 4p1).
1697 // For overloading in C, this can also be a "compatible-type"
1698 // conversion.
1699 bool IncompatibleObjC = false;
1700 ImplicitConversionKind SecondICK = ICK_Identity;
1701 if (S.Context.hasSameUnqualifiedType(FromType, ToType)) {
1702 // The unqualified versions of the types are the same: there's no
1703 // conversion to do.
1704 SCS.Second = ICK_Identity;
1705 } else if (S.IsIntegralPromotion(From, FromType, ToType)) {
1706 // Integral promotion (C++ 4.5).
1707 SCS.Second = ICK_Integral_Promotion;
1708 FromType = ToType.getUnqualifiedType();
1709 } else if (S.IsFloatingPointPromotion(FromType, ToType)) {
1710 // Floating point promotion (C++ 4.6).
1711 SCS.Second = ICK_Floating_Promotion;
1712 FromType = ToType.getUnqualifiedType();
1713 } else if (S.IsComplexPromotion(FromType, ToType)) {
1714 // Complex promotion (Clang extension)
1715 SCS.Second = ICK_Complex_Promotion;
1716 FromType = ToType.getUnqualifiedType();
1717 } else if (ToType->isBooleanType() &&
1718 (FromType->isArithmeticType() ||
1719 FromType->isAnyPointerType() ||
1720 FromType->isBlockPointerType() ||
1721 FromType->isMemberPointerType() ||
1722 FromType->isNullPtrType())) {
1723 // Boolean conversions (C++ 4.12).
1724 SCS.Second = ICK_Boolean_Conversion;
1725 FromType = S.Context.BoolTy;
1726 } else if (FromType->isIntegralOrUnscopedEnumerationType() &&
1727 ToType->isIntegralType(S.Context)) {
1728 // Integral conversions (C++ 4.7).
1729 SCS.Second = ICK_Integral_Conversion;
1730 FromType = ToType.getUnqualifiedType();
1731 } else if (FromType->isAnyComplexType() && ToType->isAnyComplexType()) {
1732 // Complex conversions (C99 6.3.1.6)
1733 SCS.Second = ICK_Complex_Conversion;
1734 FromType = ToType.getUnqualifiedType();
1735 } else if ((FromType->isAnyComplexType() && ToType->isArithmeticType()) ||
1736 (ToType->isAnyComplexType() && FromType->isArithmeticType())) {
1737 // Complex-real conversions (C99 6.3.1.7)
1738 SCS.Second = ICK_Complex_Real;
1739 FromType = ToType.getUnqualifiedType();
1740 } else if (FromType->isRealFloatingType() && ToType->isRealFloatingType()) {
1741 // FIXME: disable conversions between long double and __float128 if
1742 // their representation is different until there is back end support
1743 // We of course allow this conversion if long double is really double.
1744 if (&S.Context.getFloatTypeSemantics(FromType) !=
1745 &S.Context.getFloatTypeSemantics(ToType)) {
1746 bool Float128AndLongDouble = ((FromType == S.Context.Float128Ty &&
1747 ToType == S.Context.LongDoubleTy) ||
1748 (FromType == S.Context.LongDoubleTy &&
1749 ToType == S.Context.Float128Ty));
1750 if (Float128AndLongDouble &&
1751 (&S.Context.getFloatTypeSemantics(S.Context.LongDoubleTy) !=
1752 &llvm::APFloat::IEEEdouble()))
1753 return false;
1754 }
1755 // Floating point conversions (C++ 4.8).
1756 SCS.Second = ICK_Floating_Conversion;
1757 FromType = ToType.getUnqualifiedType();
1758 } else if ((FromType->isRealFloatingType() &&
1759 ToType->isIntegralType(S.Context)) ||
1760 (FromType->isIntegralOrUnscopedEnumerationType() &&
1761 ToType->isRealFloatingType())) {
1762 // Floating-integral conversions (C++ 4.9).
1763 SCS.Second = ICK_Floating_Integral;
1764 FromType = ToType.getUnqualifiedType();
1765 } else if (S.IsBlockPointerConversion(FromType, ToType, FromType)) {
1766 SCS.Second = ICK_Block_Pointer_Conversion;
1767 } else if (AllowObjCWritebackConversion &&
1768 S.isObjCWritebackConversion(FromType, ToType, FromType)) {
1769 SCS.Second = ICK_Writeback_Conversion;
1770 } else if (S.IsPointerConversion(From, FromType, ToType, InOverloadResolution,
1771 FromType, IncompatibleObjC)) {
1772 // Pointer conversions (C++ 4.10).
1773 SCS.Second = ICK_Pointer_Conversion;
1774 SCS.IncompatibleObjC = IncompatibleObjC;
1775 FromType = FromType.getUnqualifiedType();
1776 } else if (S.IsMemberPointerConversion(From, FromType, ToType,
1777 InOverloadResolution, FromType)) {
1778 // Pointer to member conversions (4.11).
1779 SCS.Second = ICK_Pointer_Member;
1780 } else if (IsVectorConversion(S, FromType, ToType, SecondICK)) {
1781 SCS.Second = SecondICK;
1782 FromType = ToType.getUnqualifiedType();
1783 } else if (!S.getLangOpts().CPlusPlus &&
1784 S.Context.typesAreCompatible(ToType, FromType)) {
1785 // Compatible conversions (Clang extension for C function overloading)
1786 SCS.Second = ICK_Compatible_Conversion;
1787 FromType = ToType.getUnqualifiedType();
1788 } else if (IsTransparentUnionStandardConversion(S, From, ToType,
1789 InOverloadResolution,
1790 SCS, CStyle)) {
1791 SCS.Second = ICK_TransparentUnionConversion;
1792 FromType = ToType;
1793 } else if (tryAtomicConversion(S, From, ToType, InOverloadResolution, SCS,
1794 CStyle)) {
1795 // tryAtomicConversion has updated the standard conversion sequence
1796 // appropriately.
1797 return true;
1798 } else if (ToType->isEventT() &&
1799 From->isIntegerConstantExpr(S.getASTContext()) &&
1800 From->EvaluateKnownConstInt(S.getASTContext()) == 0) {
1801 SCS.Second = ICK_Zero_Event_Conversion;
1802 FromType = ToType;
1803 } else if (ToType->isQueueT() &&
1804 From->isIntegerConstantExpr(S.getASTContext()) &&
1805 (From->EvaluateKnownConstInt(S.getASTContext()) == 0)) {
1806 SCS.Second = ICK_Zero_Queue_Conversion;
1807 FromType = ToType;
1808 } else {
1809 // No second conversion required.
1810 SCS.Second = ICK_Identity;
1811 }
1812 SCS.setToType(1, FromType);
1813
1814 // The third conversion can be a function pointer conversion or a
1815 // qualification conversion (C++ [conv.fctptr], [conv.qual]).
1816 bool ObjCLifetimeConversion;
1817 if (S.IsFunctionConversion(FromType, ToType, FromType)) {
1818 // Function pointer conversions (removing 'noexcept') including removal of
1819 // 'noreturn' (Clang extension).
1820 SCS.Third = ICK_Function_Conversion;
1821 } else if (S.IsQualificationConversion(FromType, ToType, CStyle,
1822 ObjCLifetimeConversion)) {
1823 SCS.Third = ICK_Qualification;
1824 SCS.QualificationIncludesObjCLifetime = ObjCLifetimeConversion;
1825 FromType = ToType;
1826 } else {
1827 // No conversion required
1828 SCS.Third = ICK_Identity;
1829 }
1830
1831 // C++ [over.best.ics]p6:
1832 // [...] Any difference in top-level cv-qualification is
1833 // subsumed by the initialization itself and does not constitute
1834 // a conversion. [...]
1835 QualType CanonFrom = S.Context.getCanonicalType(FromType);
1836 QualType CanonTo = S.Context.getCanonicalType(ToType);
1837 if (CanonFrom.getLocalUnqualifiedType()
1838 == CanonTo.getLocalUnqualifiedType() &&
1839 CanonFrom.getLocalQualifiers() != CanonTo.getLocalQualifiers()) {
1840 FromType = ToType;
1841 CanonFrom = CanonTo;
1842 }
1843
1844 SCS.setToType(2, FromType);
1845
1846 if (CanonFrom == CanonTo)
1847 return true;
1848
1849 // If we have not converted the argument type to the parameter type,
1850 // this is a bad conversion sequence, unless we're resolving an overload in C.
1851 if (S.getLangOpts().CPlusPlus || !InOverloadResolution)
1852 return false;
1853
1854 ExprResult ER = ExprResult{From};
1855 Sema::AssignConvertType Conv =
1856 S.CheckSingleAssignmentConstraints(ToType, ER,
1857 /*Diagnose=*/false,
1858 /*DiagnoseCFAudited=*/false,
1859 /*ConvertRHS=*/false);
1860 ImplicitConversionKind SecondConv;
1861 switch (Conv) {
1862 case Sema::Compatible:
1863 SecondConv = ICK_C_Only_Conversion;
1864 break;
1865 // For our purposes, discarding qualifiers is just as bad as using an
1866 // incompatible pointer. Note that an IncompatiblePointer conversion can drop
1867 // qualifiers, as well.
1868 case Sema::CompatiblePointerDiscardsQualifiers:
1869 case Sema::IncompatiblePointer:
1870 case Sema::IncompatiblePointerSign:
1871 SecondConv = ICK_Incompatible_Pointer_Conversion;
1872 break;
1873 default:
1874 return false;
1875 }
1876
1877 // First can only be an lvalue conversion, so we pretend that this was the
1878 // second conversion. First should already be valid from earlier in the
1879 // function.
1880 SCS.Second = SecondConv;
1881 SCS.setToType(1, ToType);
1882
1883 // Third is Identity, because Second should rank us worse than any other
1884 // conversion. This could also be ICK_Qualification, but it's simpler to just
1885 // lump everything in with the second conversion, and we don't gain anything
1886 // from making this ICK_Qualification.
1887 SCS.Third = ICK_Identity;
1888 SCS.setToType(2, ToType);
1889 return true;
1890}
1891
1892static bool
1893IsTransparentUnionStandardConversion(Sema &S, Expr* From,
1894 QualType &ToType,
1895 bool InOverloadResolution,
1896 StandardConversionSequence &SCS,
1897 bool CStyle) {
1898
1899 const RecordType *UT = ToType->getAsUnionType();
1900 if (!UT || !UT->getDecl()->hasAttr<TransparentUnionAttr>())
1901 return false;
1902 // The field to initialize within the transparent union.
1903 RecordDecl *UD = UT->getDecl();
1904 // It's compatible if the expression matches any of the fields.
1905 for (const auto *it : UD->fields()) {
1906 if (IsStandardConversion(S, From, it->getType(), InOverloadResolution, SCS,
1907 CStyle, /*ObjCWritebackConversion=*/false)) {
1908 ToType = it->getType();
1909 return true;
1910 }
1911 }
1912 return false;
1913}
1914
1915/// IsIntegralPromotion - Determines whether the conversion from the
1916/// expression From (whose potentially-adjusted type is FromType) to
1917/// ToType is an integral promotion (C++ 4.5). If so, returns true and
1918/// sets PromotedType to the promoted type.
1919bool Sema::IsIntegralPromotion(Expr *From, QualType FromType, QualType ToType) {
1920 const BuiltinType *To = ToType->getAs<BuiltinType>();
1921 // All integers are built-in.
1922 if (!To) {
1923 return false;
1924 }
1925
1926 // An rvalue of type char, signed char, unsigned char, short int, or
1927 // unsigned short int can be converted to an rvalue of type int if
1928 // int can represent all the values of the source type; otherwise,
1929 // the source rvalue can be converted to an rvalue of type unsigned
1930 // int (C++ 4.5p1).
1931 if (FromType->isPromotableIntegerType() && !FromType->isBooleanType() &&
1932 !FromType->isEnumeralType()) {
1933 if (// We can promote any signed, promotable integer type to an int
1934 (FromType->isSignedIntegerType() ||
1935 // We can promote any unsigned integer type whose size is
1936 // less than int to an int.
1937 Context.getTypeSize(FromType) < Context.getTypeSize(ToType))) {
1938 return To->getKind() == BuiltinType::Int;
1939 }
1940
1941 return To->getKind() == BuiltinType::UInt;
1942 }
1943
1944 // C++11 [conv.prom]p3:
1945 // A prvalue of an unscoped enumeration type whose underlying type is not
1946 // fixed (7.2) can be converted to an rvalue a prvalue of the first of the
1947 // following types that can represent all the values of the enumeration
1948 // (i.e., the values in the range bmin to bmax as described in 7.2): int,
1949 // unsigned int, long int, unsigned long int, long long int, or unsigned
1950 // long long int. If none of the types in that list can represent all the
1951 // values of the enumeration, an rvalue a prvalue of an unscoped enumeration
1952 // type can be converted to an rvalue a prvalue of the extended integer type
1953 // with lowest integer conversion rank (4.13) greater than the rank of long
1954 // long in which all the values of the enumeration can be represented. If
1955 // there are two such extended types, the signed one is chosen.
1956 // C++11 [conv.prom]p4:
1957 // A prvalue of an unscoped enumeration type whose underlying type is fixed
1958 // can be converted to a prvalue of its underlying type. Moreover, if
1959 // integral promotion can be applied to its underlying type, a prvalue of an
1960 // unscoped enumeration type whose underlying type is fixed can also be
1961 // converted to a prvalue of the promoted underlying type.
1962 if (const EnumType *FromEnumType = FromType->getAs<EnumType>()) {
1963 // C++0x 7.2p9: Note that this implicit enum to int conversion is not
1964 // provided for a scoped enumeration.
1965 if (FromEnumType->getDecl()->isScoped())
1966 return false;
1967
1968 // We can perform an integral promotion to the underlying type of the enum,
1969 // even if that's not the promoted type. Note that the check for promoting
1970 // the underlying type is based on the type alone, and does not consider
1971 // the bitfield-ness of the actual source expression.
1972 if (FromEnumType->getDecl()->isFixed()) {
1973 QualType Underlying = FromEnumType->getDecl()->getIntegerType();
1974 return Context.hasSameUnqualifiedType(Underlying, ToType) ||
1975 IsIntegralPromotion(nullptr, Underlying, ToType);
1976 }
1977
1978 // We have already pre-calculated the promotion type, so this is trivial.
1979 if (ToType->isIntegerType() &&
1980 isCompleteType(From->getLocStart(), FromType))
1981 return Context.hasSameUnqualifiedType(
1982 ToType, FromEnumType->getDecl()->getPromotionType());
1983 }
1984
1985 // C++0x [conv.prom]p2:
1986 // A prvalue of type char16_t, char32_t, or wchar_t (3.9.1) can be converted
1987 // to an rvalue a prvalue of the first of the following types that can
1988 // represent all the values of its underlying type: int, unsigned int,
1989 // long int, unsigned long int, long long int, or unsigned long long int.
1990 // If none of the types in that list can represent all the values of its
1991 // underlying type, an rvalue a prvalue of type char16_t, char32_t,
1992 // or wchar_t can be converted to an rvalue a prvalue of its underlying
1993 // type.
1994 if (FromType->isAnyCharacterType() && !FromType->isCharType() &&
1995 ToType->isIntegerType()) {
1996 // Determine whether the type we're converting from is signed or
1997 // unsigned.
1998 bool FromIsSigned = FromType->isSignedIntegerType();
1999 uint64_t FromSize = Context.getTypeSize(FromType);
2000
2001 // The types we'll try to promote to, in the appropriate
2002 // order. Try each of these types.
2003 QualType PromoteTypes[6] = {
2004 Context.IntTy, Context.UnsignedIntTy,
2005 Context.LongTy, Context.UnsignedLongTy ,
2006 Context.LongLongTy, Context.UnsignedLongLongTy
2007 };
2008 for (int Idx = 0; Idx < 6; ++Idx) {
2009 uint64_t ToSize = Context.getTypeSize(PromoteTypes[Idx]);
2010 if (FromSize < ToSize ||
2011 (FromSize == ToSize &&
2012 FromIsSigned == PromoteTypes[Idx]->isSignedIntegerType())) {
2013 // We found the type that we can promote to. If this is the
2014 // type we wanted, we have a promotion. Otherwise, no
2015 // promotion.
2016 return Context.hasSameUnqualifiedType(ToType, PromoteTypes[Idx]);
2017 }
2018 }
2019 }
2020
2021 // An rvalue for an integral bit-field (9.6) can be converted to an
2022 // rvalue of type int if int can represent all the values of the
2023 // bit-field; otherwise, it can be converted to unsigned int if
2024 // unsigned int can represent all the values of the bit-field. If
2025 // the bit-field is larger yet, no integral promotion applies to
2026 // it. If the bit-field has an enumerated type, it is treated as any
2027 // other value of that type for promotion purposes (C++ 4.5p3).
2028 // FIXME: We should delay checking of bit-fields until we actually perform the
2029 // conversion.
2030 if (From) {
2031 if (FieldDecl *MemberDecl = From->getSourceBitField()) {
2032 llvm::APSInt BitWidth;
2033 if (FromType->isIntegralType(Context) &&
2034 MemberDecl->getBitWidth()->isIntegerConstantExpr(BitWidth, Context)) {
2035 llvm::APSInt ToSize(BitWidth.getBitWidth(), BitWidth.isUnsigned());
2036 ToSize = Context.getTypeSize(ToType);
2037
2038 // Are we promoting to an int from a bitfield that fits in an int?
2039 if (BitWidth < ToSize ||
2040 (FromType->isSignedIntegerType() && BitWidth <= ToSize)) {
2041 return To->getKind() == BuiltinType::Int;
2042 }
2043
2044 // Are we promoting to an unsigned int from an unsigned bitfield
2045 // that fits into an unsigned int?
2046 if (FromType->isUnsignedIntegerType() && BitWidth <= ToSize) {
2047 return To->getKind() == BuiltinType::UInt;
2048 }
2049
2050 return false;
2051 }
2052 }
2053 }
2054
2055 // An rvalue of type bool can be converted to an rvalue of type int,
2056 // with false becoming zero and true becoming one (C++ 4.5p4).
2057 if (FromType->isBooleanType() && To->getKind() == BuiltinType::Int) {
2058 return true;
2059 }
2060
2061 return false;
2062}
2063
2064/// IsFloatingPointPromotion - Determines whether the conversion from
2065/// FromType to ToType is a floating point promotion (C++ 4.6). If so,
2066/// returns true and sets PromotedType to the promoted type.
2067bool Sema::IsFloatingPointPromotion(QualType FromType, QualType ToType) {
2068 if (const BuiltinType *FromBuiltin = FromType->getAs<BuiltinType>())
2069 if (const BuiltinType *ToBuiltin = ToType->getAs<BuiltinType>()) {
2070 /// An rvalue of type float can be converted to an rvalue of type
2071 /// double. (C++ 4.6p1).
2072 if (FromBuiltin->getKind() == BuiltinType::Float &&
2073 ToBuiltin->getKind() == BuiltinType::Double)
2074 return true;
2075
2076 // C99 6.3.1.5p1:
2077 // When a float is promoted to double or long double, or a
2078 // double is promoted to long double [...].
2079 if (!getLangOpts().CPlusPlus &&
2080 (FromBuiltin->getKind() == BuiltinType::Float ||
2081 FromBuiltin->getKind() == BuiltinType::Double) &&
2082 (ToBuiltin->getKind() == BuiltinType::LongDouble ||
2083 ToBuiltin->getKind() == BuiltinType::Float128))
2084 return true;
2085
2086 // Half can be promoted to float.
2087 if (!getLangOpts().NativeHalfType &&
2088 FromBuiltin->getKind() == BuiltinType::Half &&
2089 ToBuiltin->getKind() == BuiltinType::Float)
2090 return true;
2091 }
2092
2093 return false;
2094}
2095
2096/// \brief Determine if a conversion is a complex promotion.
2097///
2098/// A complex promotion is defined as a complex -> complex conversion
2099/// where the conversion between the underlying real types is a
2100/// floating-point or integral promotion.
2101bool Sema::IsComplexPromotion(QualType FromType, QualType ToType) {
2102 const ComplexType *FromComplex = FromType->getAs<ComplexType>();
2103 if (!FromComplex)
2104 return false;
2105
2106 const ComplexType *ToComplex = ToType->getAs<ComplexType>();
2107 if (!ToComplex)
2108 return false;
2109
2110 return IsFloatingPointPromotion(FromComplex->getElementType(),
2111 ToComplex->getElementType()) ||
2112 IsIntegralPromotion(nullptr, FromComplex->getElementType(),
2113 ToComplex->getElementType());
2114}
2115
2116/// BuildSimilarlyQualifiedPointerType - In a pointer conversion from
2117/// the pointer type FromPtr to a pointer to type ToPointee, with the
2118/// same type qualifiers as FromPtr has on its pointee type. ToType,
2119/// if non-empty, will be a pointer to ToType that may or may not have
2120/// the right set of qualifiers on its pointee.
2121///
2122static QualType
2123BuildSimilarlyQualifiedPointerType(const Type *FromPtr,
2124 QualType ToPointee, QualType ToType,
2125 ASTContext &Context,
2126 bool StripObjCLifetime = false) {
2127 assert((FromPtr->getTypeClass() == Type::Pointer ||(((FromPtr->getTypeClass() == Type::Pointer || FromPtr->
getTypeClass() == Type::ObjCObjectPointer) && "Invalid similarly-qualified pointer type"
) ? static_cast<void> (0) : __assert_fail ("(FromPtr->getTypeClass() == Type::Pointer || FromPtr->getTypeClass() == Type::ObjCObjectPointer) && \"Invalid similarly-qualified pointer type\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303373/tools/clang/lib/Sema/SemaOverload.cpp"
, 2129, __PRETTY_FUNCTION__))
2128 FromPtr->getTypeClass() == Type::ObjCObjectPointer) &&(((FromPtr->getTypeClass() == Type::Pointer || FromPtr->
getTypeClass() == Type::ObjCObjectPointer) && "Invalid similarly-qualified pointer type"
) ? static_cast<void> (0) : __assert_fail ("(FromPtr->getTypeClass() == Type::Pointer || FromPtr->getTypeClass() == Type::ObjCObjectPointer) && \"Invalid similarly-qualified pointer type\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303373/tools/clang/lib/Sema/SemaOverload.cpp"
, 2129, __PRETTY_FUNCTION__))
2129 "Invalid similarly-qualified pointer type")(((FromPtr->getTypeClass() == Type::Pointer || FromPtr->
getTypeClass() == Type::ObjCObjectPointer) && "Invalid similarly-qualified pointer type"
) ? static_cast<void> (0) : __assert_fail ("(FromPtr->getTypeClass() == Type::Pointer || FromPtr->getTypeClass() == Type::ObjCObjectPointer) && \"Invalid similarly-qualified pointer type\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303373/tools/clang/lib/Sema/SemaOverload.cpp"
, 2129, __PRETTY_FUNCTION__))
;
2130
2131 /// Conversions to 'id' subsume cv-qualifier conversions.
2132 if (ToType->isObjCIdType() || ToType->isObjCQualifiedIdType())
2133 return ToType.getUnqualifiedType();
2134
2135 QualType CanonFromPointee
2136 = Context.getCanonicalType(FromPtr->getPointeeType());
2137 QualType CanonToPointee = Context.getCanonicalType(ToPointee);
2138 Qualifiers Quals = CanonFromPointee.getQualifiers();
2139
2140 if (StripObjCLifetime)
2141 Quals.removeObjCLifetime();
2142
2143 // Exact qualifier match -> return the pointer type we're converting to.
2144 if (CanonToPointee.getLocalQualifiers() == Quals) {
2145 // ToType is exactly what we need. Return it.
2146 if (!ToType.isNull())
2147 return ToType.getUnqualifiedType();
2148
2149 // Build a pointer to ToPointee. It has the right qualifiers
2150 // already.
2151 if (isa<ObjCObjectPointerType>(ToType))
2152 return Context.getObjCObjectPointerType(ToPointee);
2153 return Context.getPointerType(ToPointee);
2154 }
2155
2156 // Just build a canonical type that has the right qualifiers.
2157 QualType QualifiedCanonToPointee
2158 = Context.getQualifiedType(CanonToPointee.getLocalUnqualifiedType(), Quals);
2159
2160 if (isa<ObjCObjectPointerType>(ToType))
2161 return Context.getObjCObjectPointerType(QualifiedCanonToPointee);
2162 return Context.getPointerType(QualifiedCanonToPointee);
2163}
2164
2165static bool isNullPointerConstantForConversion(Expr *Expr,
2166 bool InOverloadResolution,
2167 ASTContext &Context) {
2168 // Handle value-dependent integral null pointer constants correctly.
2169 // http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#903
2170 if (Expr->isValueDependent() && !Expr->isTypeDependent() &&
2171 Expr->getType()->isIntegerType() && !Expr->getType()->isEnumeralType())
2172 return !InOverloadResolution;
2173
2174 return Expr->isNullPointerConstant(Context,
2175 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull
2176 : Expr::NPC_ValueDependentIsNull);
2177}
2178
2179/// IsPointerConversion - Determines whether the conversion of the
2180/// expression From, which has the (possibly adjusted) type FromType,
2181/// can be converted to the type ToType via a pointer conversion (C++
2182/// 4.10). If so, returns true and places the converted type (that
2183/// might differ from ToType in its cv-qualifiers at some level) into
2184/// ConvertedType.
2185///
2186/// This routine also supports conversions to and from block pointers
2187/// and conversions with Objective-C's 'id', 'id<protocols...>', and
2188/// pointers to interfaces. FIXME: Once we've determined the
2189/// appropriate overloading rules for Objective-C, we may want to
2190/// split the Objective-C checks into a different routine; however,
2191/// GCC seems to consider all of these conversions to be pointer
2192/// conversions, so for now they live here. IncompatibleObjC will be
2193/// set if the conversion is an allowed Objective-C conversion that
2194/// should result in a warning.
2195bool Sema::IsPointerConversion(Expr *From, QualType FromType, QualType ToType,
2196 bool InOverloadResolution,
2197 QualType& ConvertedType,
2198 bool &IncompatibleObjC) {
2199 IncompatibleObjC = false;
2200 if (isObjCPointerConversion(FromType, ToType, ConvertedType,
2201 IncompatibleObjC))
2202 return true;
2203
2204 // Conversion from a null pointer constant to any Objective-C pointer type.
2205 if (ToType->isObjCObjectPointerType() &&
2206 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) {
2207 ConvertedType = ToType;
2208 return true;
2209 }
2210
2211 // Blocks: Block pointers can be converted to void*.
2212 if (FromType->isBlockPointerType() && ToType->isPointerType() &&
2213 ToType->getAs<PointerType>()->getPointeeType()->isVoidType()) {
2214 ConvertedType = ToType;
2215 return true;
2216 }
2217 // Blocks: A null pointer constant can be converted to a block
2218 // pointer type.
2219 if (ToType->isBlockPointerType() &&
2220 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) {
2221 ConvertedType = ToType;
2222 return true;
2223 }
2224
2225 // If the left-hand-side is nullptr_t, the right side can be a null
2226 // pointer constant.
2227 if (ToType->isNullPtrType() &&
2228 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) {
2229 ConvertedType = ToType;
2230 return true;
2231 }
2232
2233 const PointerType* ToTypePtr = ToType->getAs<PointerType>();
2234 if (!ToTypePtr)
2235 return false;
2236
2237 // A null pointer constant can be converted to a pointer type (C++ 4.10p1).
2238 if (isNullPointerConstantForConversion(From, InOverloadResolution, Context)) {
2239 ConvertedType = ToType;
2240 return true;
2241 }
2242
2243 // Beyond this point, both types need to be pointers
2244 // , including objective-c pointers.
2245 QualType ToPointeeType = ToTypePtr->getPointeeType();
2246 if (FromType->isObjCObjectPointerType() && ToPointeeType->isVoidType() &&
2247 !getLangOpts().ObjCAutoRefCount) {
2248 ConvertedType = BuildSimilarlyQualifiedPointerType(
2249 FromType->getAs<ObjCObjectPointerType>(),
2250 ToPointeeType,
2251 ToType, Context);
2252 return true;
2253 }
2254 const PointerType *FromTypePtr = FromType->getAs<PointerType>();
2255 if (!FromTypePtr)
2256 return false;
2257
2258 QualType FromPointeeType = FromTypePtr->getPointeeType();
2259
2260 // If the unqualified pointee types are the same, this can't be a
2261 // pointer conversion, so don't do all of the work below.
2262 if (Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType))
2263 return false;
2264
2265 // An rvalue of type "pointer to cv T," where T is an object type,
2266 // can be converted to an rvalue of type "pointer to cv void" (C++
2267 // 4.10p2).
2268 if (FromPointeeType->isIncompleteOrObjectType() &&
2269 ToPointeeType->isVoidType()) {
2270 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr,
2271 ToPointeeType,
2272 ToType, Context,
2273 /*StripObjCLifetime=*/true);
2274 return true;
2275 }
2276
2277 // MSVC allows implicit function to void* type conversion.
2278 if (getLangOpts().MSVCCompat && FromPointeeType->isFunctionType() &&
2279 ToPointeeType->isVoidType()) {
2280 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr,
2281 ToPointeeType,
2282 ToType, Context);
2283 return true;
2284 }
2285
2286 // When we're overloading in C, we allow a special kind of pointer
2287 // conversion for compatible-but-not-identical pointee types.
2288 if (!getLangOpts().CPlusPlus &&
2289 Context.typesAreCompatible(FromPointeeType, ToPointeeType)) {
2290 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr,
2291 ToPointeeType,
2292 ToType, Context);
2293 return true;
2294 }
2295
2296 // C++ [conv.ptr]p3:
2297 //
2298 // An rvalue of type "pointer to cv D," where D is a class type,
2299 // can be converted to an rvalue of type "pointer to cv B," where
2300 // B is a base class (clause 10) of D. If B is an inaccessible
2301 // (clause 11) or ambiguous (10.2) base class of D, a program that
2302 // necessitates this conversion is ill-formed. The result of the
2303 // conversion is a pointer to the base class sub-object of the
2304 // derived class object. The null pointer value is converted to
2305 // the null pointer value of the destination type.
2306 //
2307 // Note that we do not check for ambiguity or inaccessibility
2308 // here. That is handled by CheckPointerConversion.
2309 if (getLangOpts().CPlusPlus &&
2310 FromPointeeType->isRecordType() && ToPointeeType->isRecordType() &&
2311 !Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType) &&
2312 IsDerivedFrom(From->getLocStart(), FromPointeeType, ToPointeeType)) {
2313 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr,
2314 ToPointeeType,
2315 ToType, Context);
2316 return true;
2317 }
2318
2319 if (FromPointeeType->isVectorType() && ToPointeeType->isVectorType() &&
2320 Context.areCompatibleVectorTypes(FromPointeeType, ToPointeeType)) {
2321 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr,
2322 ToPointeeType,
2323 ToType, Context);
2324 return true;
2325 }
2326
2327 return false;
2328}
2329
2330/// \brief Adopt the given qualifiers for the given type.
2331static QualType AdoptQualifiers(ASTContext &Context, QualType T, Qualifiers Qs){
2332 Qualifiers TQs = T.getQualifiers();
2333
2334 // Check whether qualifiers already match.
2335 if (TQs == Qs)
2336 return T;
2337
2338 if (Qs.compatiblyIncludes(TQs))
2339 return Context.getQualifiedType(T, Qs);
2340
2341 return Context.getQualifiedType(T.getUnqualifiedType(), Qs);
2342}
2343
2344/// isObjCPointerConversion - Determines whether this is an
2345/// Objective-C pointer conversion. Subroutine of IsPointerConversion,
2346/// with the same arguments and return values.
2347bool Sema::isObjCPointerConversion(QualType FromType, QualType ToType,
2348 QualType& ConvertedType,
2349 bool &IncompatibleObjC) {
2350 if (!getLangOpts().ObjC1)
2351 return false;
2352
2353 // The set of qualifiers on the type we're converting from.
2354 Qualifiers FromQualifiers = FromType.getQualifiers();
2355
2356 // First, we handle all conversions on ObjC object pointer types.
2357 const ObjCObjectPointerType* ToObjCPtr =
2358 ToType->getAs<ObjCObjectPointerType>();
2359 const ObjCObjectPointerType *FromObjCPtr =
2360 FromType->getAs<ObjCObjectPointerType>();
2361
2362 if (ToObjCPtr && FromObjCPtr) {
2363 // If the pointee types are the same (ignoring qualifications),
2364 // then this is not a pointer conversion.
2365 if (Context.hasSameUnqualifiedType(ToObjCPtr->getPointeeType(),
2366 FromObjCPtr->getPointeeType()))
2367 return false;
2368
2369 // Conversion between Objective-C pointers.
2370 if (Context.canAssignObjCInterfaces(ToObjCPtr, FromObjCPtr)) {
2371 const ObjCInterfaceType* LHS = ToObjCPtr->getInterfaceType();
2372 const ObjCInterfaceType* RHS = FromObjCPtr->getInterfaceType();
2373 if (getLangOpts().CPlusPlus && LHS && RHS &&
2374 !ToObjCPtr->getPointeeType().isAtLeastAsQualifiedAs(
2375 FromObjCPtr->getPointeeType()))
2376 return false;
2377 ConvertedType = BuildSimilarlyQualifiedPointerType(FromObjCPtr,
2378 ToObjCPtr->getPointeeType(),
2379 ToType, Context);
2380 ConvertedType = AdoptQualifiers(Context, ConvertedType, FromQualifiers);
2381 return true;
2382 }
2383
2384 if (Context.canAssignObjCInterfaces(FromObjCPtr, ToObjCPtr)) {
2385 // Okay: this is some kind of implicit downcast of Objective-C
2386 // interfaces, which is permitted. However, we're going to
2387 // complain about it.
2388 IncompatibleObjC = true;
2389 ConvertedType = BuildSimilarlyQualifiedPointerType(FromObjCPtr,
2390 ToObjCPtr->getPointeeType(),
2391 ToType, Context);
2392 ConvertedType = AdoptQualifiers(Context, ConvertedType, FromQualifiers);
2393 return true;
2394 }
2395 }
2396 // Beyond this point, both types need to be C pointers or block pointers.
2397 QualType ToPointeeType;
2398 if (const PointerType *ToCPtr = ToType->getAs<PointerType>())
2399 ToPointeeType = ToCPtr->getPointeeType();
2400 else if (const BlockPointerType *ToBlockPtr =
2401 ToType->getAs<BlockPointerType>()) {
2402 // Objective C++: We're able to convert from a pointer to any object
2403 // to a block pointer type.
2404 if (FromObjCPtr && FromObjCPtr->isObjCBuiltinType()) {
2405 ConvertedType = AdoptQualifiers(Context, ToType, FromQualifiers);
2406 return true;
2407 }
2408 ToPointeeType = ToBlockPtr->getPointeeType();
2409 }
2410 else if (FromType->getAs<BlockPointerType>() &&
2411 ToObjCPtr && ToObjCPtr->isObjCBuiltinType()) {
2412 // Objective C++: We're able to convert from a block pointer type to a
2413 // pointer to any object.
2414 ConvertedType = AdoptQualifiers(Context, ToType, FromQualifiers);
2415 return true;
2416 }
2417 else
2418 return false;
2419
2420 QualType FromPointeeType;
2421 if (const PointerType *FromCPtr = FromType->getAs<PointerType>())
2422 FromPointeeType = FromCPtr->getPointeeType();
2423 else if (const BlockPointerType *FromBlockPtr =
2424 FromType->getAs<BlockPointerType>())
2425 FromPointeeType = FromBlockPtr->getPointeeType();
2426 else
2427 return false;
2428
2429 // If we have pointers to pointers, recursively check whether this
2430 // is an Objective-C conversion.
2431 if (FromPointeeType->isPointerType() && ToPointeeType->isPointerType() &&
2432 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType,
2433 IncompatibleObjC)) {
2434 // We always complain about this conversion.
2435 IncompatibleObjC = true;
2436 ConvertedType = Context.getPointerType(ConvertedType);
2437 ConvertedType = AdoptQualifiers(Context, ConvertedType, FromQualifiers);
2438 return true;
2439 }
2440 // Allow conversion of pointee being objective-c pointer to another one;
2441 // as in I* to id.
2442 if (FromPointeeType->getAs<ObjCObjectPointerType>() &&
2443 ToPointeeType->getAs<ObjCObjectPointerType>() &&
2444 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType,
2445 IncompatibleObjC)) {
2446
2447 ConvertedType = Context.getPointerType(ConvertedType);
2448 ConvertedType = AdoptQualifiers(Context, ConvertedType, FromQualifiers);
2449 return true;
2450 }
2451
2452 // If we have pointers to functions or blocks, check whether the only
2453 // differences in the argument and result types are in Objective-C
2454 // pointer conversions. If so, we permit the conversion (but
2455 // complain about it).
2456 const FunctionProtoType *FromFunctionType
2457 = FromPointeeType->getAs<FunctionProtoType>();
2458 const FunctionProtoType *ToFunctionType
2459 = ToPointeeType->getAs<FunctionProtoType>();
2460 if (FromFunctionType && ToFunctionType) {
2461 // If the function types are exactly the same, this isn't an
2462 // Objective-C pointer conversion.
2463 if (Context.getCanonicalType(FromPointeeType)
2464 == Context.getCanonicalType(ToPointeeType))
2465 return false;
2466
2467 // Perform the quick checks that will tell us whether these
2468 // function types are obviously different.
2469 if (FromFunctionType->getNumParams() != ToFunctionType->getNumParams() ||
2470 FromFunctionType->isVariadic() != ToFunctionType->isVariadic() ||
2471 FromFunctionType->getTypeQuals() != ToFunctionType->getTypeQuals())
2472 return false;
2473
2474 bool HasObjCConversion = false;
2475 if (Context.getCanonicalType(FromFunctionType->getReturnType()) ==
2476 Context.getCanonicalType(ToFunctionType->getReturnType())) {
2477 // Okay, the types match exactly. Nothing to do.
2478 } else if (isObjCPointerConversion(FromFunctionType->getReturnType(),
2479 ToFunctionType->getReturnType(),
2480 ConvertedType, IncompatibleObjC)) {
2481 // Okay, we have an Objective-C pointer conversion.
2482 HasObjCConversion = true;
2483 } else {
2484 // Function types are too different. Abort.
2485 return false;
2486 }
2487
2488 // Check argument types.
2489 for (unsigned ArgIdx = 0, NumArgs = FromFunctionType->getNumParams();
2490 ArgIdx != NumArgs; ++ArgIdx) {
2491 QualType FromArgType = FromFunctionType->getParamType(ArgIdx);
2492 QualType ToArgType = ToFunctionType->getParamType(ArgIdx);
2493 if (Context.getCanonicalType(FromArgType)
2494 == Context.getCanonicalType(ToArgType)) {
2495 // Okay, the types match exactly. Nothing to do.
2496 } else if (isObjCPointerConversion(FromArgType, ToArgType,
2497 ConvertedType, IncompatibleObjC)) {
2498 // Okay, we have an Objective-C pointer conversion.
2499 HasObjCConversion = true;
2500 } else {
2501 // Argument types are too different. Abort.
2502 return false;
2503 }
2504 }
2505
2506 if (HasObjCConversion) {
2507 // We had an Objective-C conversion. Allow this pointer
2508 // conversion, but complain about it.
2509 ConvertedType = AdoptQualifiers(Context, ToType, FromQualifiers);
2510 IncompatibleObjC = true;
2511 return true;
2512 }
2513 }
2514
2515 return false;
2516}
2517
2518/// \brief Determine whether this is an Objective-C writeback conversion,
2519/// used for parameter passing when performing automatic reference counting.
2520///
2521/// \param FromType The type we're converting form.
2522///
2523/// \param ToType The type we're converting to.
2524///
2525/// \param ConvertedType The type that will be produced after applying
2526/// this conversion.
2527bool Sema::isObjCWritebackConversion(QualType FromType, QualType ToType,
2528 QualType &ConvertedType) {
2529 if (!getLangOpts().ObjCAutoRefCount ||
2530 Context.hasSameUnqualifiedType(FromType, ToType))
2531 return false;
2532
2533 // Parameter must be a pointer to __autoreleasing (with no other qualifiers).
2534 QualType ToPointee;
2535 if (const PointerType *ToPointer = ToType->getAs<PointerType>())
2536 ToPointee = ToPointer->getPointeeType();
2537 else
2538 return false;
2539
2540 Qualifiers ToQuals = ToPointee.getQualifiers();
2541 if (!ToPointee->isObjCLifetimeType() ||
2542 ToQuals.getObjCLifetime() != Qualifiers::OCL_Autoreleasing ||
2543 !ToQuals.withoutObjCLifetime().empty())
2544 return false;
2545
2546 // Argument must be a pointer to __strong to __weak.
2547 QualType FromPointee;
2548 if (const PointerType *FromPointer = FromType->getAs<PointerType>())
2549 FromPointee = FromPointer->getPointeeType();
2550 else
2551 return false;
2552
2553 Qualifiers FromQuals = FromPointee.getQualifiers();
2554 if (!FromPointee->isObjCLifetimeType() ||
2555 (FromQuals.getObjCLifetime() != Qualifiers::OCL_Strong &&
2556 FromQuals.getObjCLifetime() != Qualifiers::OCL_Weak))
2557 return false;
2558
2559 // Make sure that we have compatible qualifiers.
2560 FromQuals.setObjCLifetime(Qualifiers::OCL_Autoreleasing);
2561 if (!ToQuals.compatiblyIncludes(FromQuals))
2562 return false;
2563
2564 // Remove qualifiers from the pointee type we're converting from; they
2565 // aren't used in the compatibility check belong, and we'll be adding back
2566 // qualifiers (with __autoreleasing) if the compatibility check succeeds.
2567 FromPointee = FromPointee.getUnqualifiedType();
2568
2569 // The unqualified form of the pointee types must be compatible.
2570 ToPointee = ToPointee.getUnqualifiedType();
2571 bool IncompatibleObjC;
2572 if (Context.typesAreCompatible(FromPointee, ToPointee))
2573 FromPointee = ToPointee;
2574 else if (!isObjCPointerConversion(FromPointee, ToPointee, FromPointee,
2575 IncompatibleObjC))
2576 return false;
2577
2578 /// \brief Construct the type we're converting to, which is a pointer to
2579 /// __autoreleasing pointee.
2580 FromPointee = Context.getQualifiedType(FromPointee, FromQuals);
2581 ConvertedType = Context.getPointerType(FromPointee);
2582 return true;
2583}
2584
2585bool Sema::IsBlockPointerConversion(QualType FromType, QualType ToType,
2586 QualType& ConvertedType) {
2587 QualType ToPointeeType;
2588 if (const BlockPointerType *ToBlockPtr =
2589 ToType->getAs<BlockPointerType>())
2590 ToPointeeType = ToBlockPtr->getPointeeType();
2591 else
2592 return false;
2593
2594 QualType FromPointeeType;
2595 if (const BlockPointerType *FromBlockPtr =
2596 FromType->getAs<BlockPointerType>())
2597 FromPointeeType = FromBlockPtr->getPointeeType();
2598 else
2599 return false;
2600 // We have pointer to blocks, check whether the only
2601 // differences in the argument and result types are in Objective-C
2602 // pointer conversions. If so, we permit the conversion.
2603
2604 const FunctionProtoType *FromFunctionType
2605 = FromPointeeType->getAs<FunctionProtoType>();
2606 const FunctionProtoType *ToFunctionType
2607 = ToPointeeType->getAs<FunctionProtoType>();
2608
2609 if (!FromFunctionType || !ToFunctionType)
2610 return false;
2611
2612 if (Context.hasSameType(FromPointeeType, ToPointeeType))
2613 return true;
2614
2615 // Perform the quick checks that will tell us whether these
2616 // function types are obviously different.
2617 if (FromFunctionType->getNumParams() != ToFunctionType->getNumParams() ||
2618 FromFunctionType->isVariadic() != ToFunctionType->isVariadic())
2619 return false;
2620
2621 FunctionType::ExtInfo FromEInfo = FromFunctionType->getExtInfo();
2622 FunctionType::ExtInfo ToEInfo = ToFunctionType->getExtInfo();
2623 if (FromEInfo != ToEInfo)
2624 return false;
2625
2626 bool IncompatibleObjC = false;
2627 if (Context.hasSameType(FromFunctionType->getReturnType(),
2628 ToFunctionType->getReturnType())) {
2629 // Okay, the types match exactly. Nothing to do.
2630 } else {
2631 QualType RHS = FromFunctionType->getReturnType();
2632 QualType LHS = ToFunctionType->getReturnType();
2633 if ((!getLangOpts().CPlusPlus || !RHS->isRecordType()) &&
2634 !RHS.hasQualifiers() && LHS.hasQualifiers())
2635 LHS = LHS.getUnqualifiedType();
2636
2637 if (Context.hasSameType(RHS,LHS)) {
2638 // OK exact match.
2639 } else if (isObjCPointerConversion(RHS, LHS,
2640 ConvertedType, IncompatibleObjC)) {
2641 if (IncompatibleObjC)
2642 return false;
2643 // Okay, we have an Objective-C pointer conversion.
2644 }
2645 else
2646 return false;
2647 }
2648
2649 // Check argument types.
2650 for (unsigned ArgIdx = 0, NumArgs = FromFunctionType->getNumParams();
2651 ArgIdx != NumArgs; ++ArgIdx) {
2652 IncompatibleObjC = false;
2653 QualType FromArgType = FromFunctionType->getParamType(ArgIdx);
2654 QualType ToArgType = ToFunctionType->getParamType(ArgIdx);
2655 if (Context.hasSameType(FromArgType, ToArgType)) {
2656 // Okay, the types match exactly. Nothing to do.
2657 } else if (isObjCPointerConversion(ToArgType, FromArgType,
2658 ConvertedType, IncompatibleObjC)) {
2659 if (IncompatibleObjC)
2660 return false;
2661 // Okay, we have an Objective-C pointer conversion.
2662 } else
2663 // Argument types are too different. Abort.
2664 return false;
2665 }
2666 if (!Context.doFunctionTypesMatchOnExtParameterInfos(FromFunctionType,
2667 ToFunctionType))
2668 return false;
2669
2670 ConvertedType = ToType;
2671 return true;
2672}
2673
2674enum {
2675 ft_default,
2676 ft_different_class,
2677 ft_parameter_arity,
2678 ft_parameter_mismatch,
2679 ft_return_type,
2680 ft_qualifer_mismatch,
2681 ft_noexcept
2682};
2683
2684/// Attempts to get the FunctionProtoType from a Type. Handles
2685/// MemberFunctionPointers properly.
2686static const FunctionProtoType *tryGetFunctionProtoType(QualType FromType) {
2687 if (auto *FPT = FromType->getAs<FunctionProtoType>())
2688 return FPT;
2689
2690 if (auto *MPT = FromType->getAs<MemberPointerType>())
2691 return MPT->getPointeeType()->getAs<FunctionProtoType>();
2692
2693 return nullptr;
2694}
2695
2696/// HandleFunctionTypeMismatch - Gives diagnostic information for differeing
2697/// function types. Catches different number of parameter, mismatch in
2698/// parameter types, and different return types.
2699void Sema::HandleFunctionTypeMismatch(PartialDiagnostic &PDiag,
2700 QualType FromType, QualType ToType) {
2701 // If either type is not valid, include no extra info.
2702 if (FromType.isNull() || ToType.isNull()) {
2703 PDiag << ft_default;
2704 return;
2705 }
2706
2707 // Get the function type from the pointers.
2708 if (FromType->isMemberPointerType() && ToType->isMemberPointerType()) {
2709 const MemberPointerType *FromMember = FromType->getAs<MemberPointerType>(),
2710 *ToMember = ToType->getAs<MemberPointerType>();
2711 if (!Context.hasSameType(FromMember->getClass(), ToMember->getClass())) {
2712 PDiag << ft_different_class << QualType(ToMember->getClass(), 0)
2713 << QualType(FromMember->getClass(), 0);
2714 return;
2715 }
2716 FromType = FromMember->getPointeeType();
2717 ToType = ToMember->getPointeeType();
2718 }
2719
2720 if (FromType->isPointerType())
2721 FromType = FromType->getPointeeType();
2722 if (ToType->isPointerType())
2723 ToType = ToType->getPointeeType();
2724
2725 // Remove references.
2726 FromType = FromType.getNonReferenceType();
2727 ToType = ToType.getNonReferenceType();
2728
2729 // Don't print extra info for non-specialized template functions.
2730 if (FromType->isInstantiationDependentType() &&
2731 !FromType->getAs<TemplateSpecializationType>()) {
2732 PDiag << ft_default;
2733 return;
2734 }
2735
2736 // No extra info for same types.
2737 if (Context.hasSameType(FromType, ToType)) {
2738 PDiag << ft_default;
2739 return;
2740 }
2741
2742 const FunctionProtoType *FromFunction = tryGetFunctionProtoType(FromType),
2743 *ToFunction = tryGetFunctionProtoType(ToType);
2744
2745 // Both types need to be function types.
2746 if (!FromFunction || !ToFunction) {
2747 PDiag << ft_default;
2748 return;
2749 }
2750
2751 if (FromFunction->getNumParams() != ToFunction->getNumParams()) {
2752 PDiag << ft_parameter_arity << ToFunction->getNumParams()
2753 << FromFunction->getNumParams();
2754 return;
2755 }
2756
2757 // Handle different parameter types.
2758 unsigned ArgPos;
2759 if (!FunctionParamTypesAreEqual(FromFunction, ToFunction, &ArgPos)) {
2760 PDiag << ft_parameter_mismatch << ArgPos + 1
2761 << ToFunction->getParamType(ArgPos)
2762 << FromFunction->getParamType(ArgPos);
2763 return;
2764 }
2765
2766 // Handle different return type.
2767 if (!Context.hasSameType(FromFunction->getReturnType(),
2768 ToFunction->getReturnType())) {
2769 PDiag << ft_return_type << ToFunction->getReturnType()
2770 << FromFunction->getReturnType();
2771 return;
2772 }
2773
2774 unsigned FromQuals = FromFunction->getTypeQuals(),
2775 ToQuals = ToFunction->getTypeQuals();
2776 if (FromQuals != ToQuals) {
2777 PDiag << ft_qualifer_mismatch << ToQuals << FromQuals;
2778 return;
2779 }
2780
2781 // Handle exception specification differences on canonical type (in C++17
2782 // onwards).
2783 if (cast<FunctionProtoType>(FromFunction->getCanonicalTypeUnqualified())
2784 ->isNothrow(Context) !=
2785 cast<FunctionProtoType>(ToFunction->getCanonicalTypeUnqualified())
2786 ->isNothrow(Context)) {
2787 PDiag << ft_noexcept;
2788 return;
2789 }
2790
2791 // Unable to find a difference, so add no extra info.
2792 PDiag << ft_default;
2793}
2794
2795/// FunctionParamTypesAreEqual - This routine checks two function proto types
2796/// for equality of their argument types. Caller has already checked that
2797/// they have same number of arguments. If the parameters are different,
2798/// ArgPos will have the parameter index of the first different parameter.
2799bool Sema::FunctionParamTypesAreEqual(const FunctionProtoType *OldType,
2800 const FunctionProtoType *NewType,
2801 unsigned *ArgPos) {
2802 for (FunctionProtoType::param_type_iterator O = OldType->param_type_begin(),
2803 N = NewType->param_type_begin(),
2804 E = OldType->param_type_end();
2805 O && (O != E); ++O, ++N) {
2806 if (!Context.hasSameType(O->getUnqualifiedType(),
2807 N->getUnqualifiedType())) {
2808 if (ArgPos)
2809 *ArgPos = O - OldType->param_type_begin();
2810 return false;
2811 }
2812 }
2813 return true;
2814}
2815
2816/// CheckPointerConversion - Check the pointer conversion from the
2817/// expression From to the type ToType. This routine checks for
2818/// ambiguous or inaccessible derived-to-base pointer
2819/// conversions for which IsPointerConversion has already returned
2820/// true. It returns true and produces a diagnostic if there was an
2821/// error, or returns false otherwise.
2822bool Sema::CheckPointerConversion(Expr *From, QualType ToType,
2823 CastKind &Kind,
2824 CXXCastPath& BasePath,
2825 bool IgnoreBaseAccess,
2826 bool Diagnose) {
2827 QualType FromType = From->getType();
2828 bool IsCStyleOrFunctionalCast = IgnoreBaseAccess;
2829
2830 Kind = CK_BitCast;
2831
2832 if (Diagnose && !IsCStyleOrFunctionalCast && !FromType->isAnyPointerType() &&
2833 From->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNotNull) ==
2834 Expr::NPCK_ZeroExpression) {
2835 if (Context.hasSameUnqualifiedType(From->getType(), Context.BoolTy))
2836 DiagRuntimeBehavior(From->getExprLoc(), From,
2837 PDiag(diag::warn_impcast_bool_to_null_pointer)
2838 << ToType << From->getSourceRange());
2839 else if (!isUnevaluatedContext())
2840 Diag(From->getExprLoc(), diag::warn_non_literal_null_pointer)
2841 << ToType << From->getSourceRange();
2842 }
2843 if (const PointerType *ToPtrType = ToType->getAs<PointerType>()) {
2844 if (const PointerType *FromPtrType = FromType->getAs<PointerType>()) {
2845 QualType FromPointeeType = FromPtrType->getPointeeType(),
2846 ToPointeeType = ToPtrType->getPointeeType();
2847
2848 if (FromPointeeType->isRecordType() && ToPointeeType->isRecordType() &&
2849 !Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType)) {
2850 // We must have a derived-to-base conversion. Check an
2851 // ambiguous or inaccessible conversion.
2852 unsigned InaccessibleID = 0;
2853 unsigned AmbigiousID = 0;
2854 if (Diagnose) {
2855 InaccessibleID = diag::err_upcast_to_inaccessible_base;
2856 AmbigiousID = diag::err_ambiguous_derived_to_base_conv;
2857 }
2858 if (CheckDerivedToBaseConversion(
2859 FromPointeeType, ToPointeeType, InaccessibleID, AmbigiousID,
2860 From->getExprLoc(), From->getSourceRange(), DeclarationName(),
2861 &BasePath, IgnoreBaseAccess))
2862 return true;
2863
2864 // The conversion was successful.
2865 Kind = CK_DerivedToBase;
2866 }
2867
2868 if (Diagnose && !IsCStyleOrFunctionalCast &&
2869 FromPointeeType->isFunctionType() && ToPointeeType->isVoidType()) {
2870 assert(getLangOpts().MSVCCompat &&((getLangOpts().MSVCCompat && "this should only be possible with MSVCCompat!"
) ? static_cast<void> (0) : __assert_fail ("getLangOpts().MSVCCompat && \"this should only be possible with MSVCCompat!\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303373/tools/clang/lib/Sema/SemaOverload.cpp"
, 2871, __PRETTY_FUNCTION__))
2871 "this should only be possible with MSVCCompat!")((getLangOpts().MSVCCompat && "this should only be possible with MSVCCompat!"
) ? static_cast<void> (0) : __assert_fail ("getLangOpts().MSVCCompat && \"this should only be possible with MSVCCompat!\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303373/tools/clang/lib/Sema/SemaOverload.cpp"
, 2871, __PRETTY_FUNCTION__))
;
2872 Diag(From->getExprLoc(), diag::ext_ms_impcast_fn_obj)
2873 << From->getSourceRange();
2874 }
2875 }
2876 } else if (const ObjCObjectPointerType *ToPtrType =
2877 ToType->getAs<ObjCObjectPointerType>()) {
2878 if (const ObjCObjectPointerType *FromPtrType =
2879 FromType->getAs<ObjCObjectPointerType>()) {
2880 // Objective-C++ conversions are always okay.
2881 // FIXME: We should have a different class of conversions for the
2882 // Objective-C++ implicit conversions.
2883 if (FromPtrType->isObjCBuiltinType() || ToPtrType->isObjCBuiltinType())
2884 return false;
2885 } else if (FromType->isBlockPointerType()) {
2886 Kind = CK_BlockPointerToObjCPointerCast;
2887 } else {
2888 Kind = CK_CPointerToObjCPointerCast;
2889 }
2890 } else if (ToType->isBlockPointerType()) {
2891 if (!FromType->isBlockPointerType())
2892 Kind = CK_AnyPointerToBlockPointerCast;
2893 }
2894
2895 // We shouldn't fall into this case unless it's valid for other
2896 // reasons.
2897 if (From->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull))
2898 Kind = CK_NullToPointer;
2899
2900 return false;
2901}
2902
2903/// IsMemberPointerConversion - Determines whether the conversion of the
2904/// expression From, which has the (possibly adjusted) type FromType, can be
2905/// converted to the type ToType via a member pointer conversion (C++ 4.11).
2906/// If so, returns true and places the converted type (that might differ from
2907/// ToType in its cv-qualifiers at some level) into ConvertedType.
2908bool Sema::IsMemberPointerConversion(Expr *From, QualType FromType,
2909 QualType ToType,
2910 bool InOverloadResolution,
2911 QualType &ConvertedType) {
2912 const MemberPointerType *ToTypePtr = ToType->getAs<MemberPointerType>();
2913 if (!ToTypePtr)
2914 return false;
2915
2916 // A null pointer constant can be converted to a member pointer (C++ 4.11p1)
2917 if (From->isNullPointerConstant(Context,
2918 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull
2919 : Expr::NPC_ValueDependentIsNull)) {
2920 ConvertedType = ToType;
2921 return true;
2922 }
2923
2924 // Otherwise, both types have to be member pointers.
2925 const MemberPointerType *FromTypePtr = FromType->getAs<MemberPointerType>();
2926 if (!FromTypePtr)
2927 return false;
2928
2929 // A pointer to member of B can be converted to a pointer to member of D,
2930 // where D is derived from B (C++ 4.11p2).
2931 QualType FromClass(FromTypePtr->getClass(), 0);
2932 QualType ToClass(ToTypePtr->getClass(), 0);
2933
2934 if (!Context.hasSameUnqualifiedType(FromClass, ToClass) &&
2935 IsDerivedFrom(From->getLocStart(), ToClass, FromClass)) {
2936 ConvertedType = Context.getMemberPointerType(FromTypePtr->getPointeeType(),
2937 ToClass.getTypePtr());
2938 return true;
2939 }
2940
2941 return false;
2942}
2943
2944/// CheckMemberPointerConversion - Check the member pointer conversion from the
2945/// expression From to the type ToType. This routine checks for ambiguous or
2946/// virtual or inaccessible base-to-derived member pointer conversions
2947/// for which IsMemberPointerConversion has already returned true. It returns
2948/// true and produces a diagnostic if there was an error, or returns false
2949/// otherwise.
2950bool Sema::CheckMemberPointerConversion(Expr *From, QualType ToType,
2951 CastKind &Kind,
2952 CXXCastPath &BasePath,
2953 bool IgnoreBaseAccess) {
2954 QualType FromType = From->getType();
2955 const MemberPointerType *FromPtrType = FromType->getAs<MemberPointerType>();
2956 if (!FromPtrType) {
2957 // This must be a null pointer to member pointer conversion
2958 assert(From->isNullPointerConstant(Context,((From->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull
) && "Expr must be null pointer constant!") ? static_cast
<void> (0) : __assert_fail ("From->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull) && \"Expr must be null pointer constant!\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303373/tools/clang/lib/Sema/SemaOverload.cpp"
, 2960, __PRETTY_FUNCTION__))
2959 Expr::NPC_ValueDependentIsNull) &&((From->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull
) && "Expr must be null pointer constant!") ? static_cast
<void> (0) : __assert_fail ("From->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull) && \"Expr must be null pointer constant!\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303373/tools/clang/lib/Sema/SemaOverload.cpp"
, 2960, __PRETTY_FUNCTION__))
2960 "Expr must be null pointer constant!")((From->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull
) && "Expr must be null pointer constant!") ? static_cast
<void> (0) : __assert_fail ("From->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull) && \"Expr must be null pointer constant!\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303373/tools/clang/lib/Sema/SemaOverload.cpp"
, 2960, __PRETTY_FUNCTION__))
;
2961 Kind = CK_NullToMemberPointer;
2962 return false;
2963 }
2964
2965 const MemberPointerType *ToPtrType = ToType->getAs<MemberPointerType>();
2966 assert(ToPtrType && "No member pointer cast has a target type "((ToPtrType && "No member pointer cast has a target type "
"that is not a member pointer.") ? static_cast<void> (
0) : __assert_fail ("ToPtrType && \"No member pointer cast has a target type \" \"that is not a member pointer.\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303373/tools/clang/lib/Sema/SemaOverload.cpp"
, 2967, __PRETTY_FUNCTION__))
2967 "that is not a member pointer.")((ToPtrType && "No member pointer cast has a target type "
"that is not a member pointer.") ? static_cast<void> (
0) : __assert_fail ("ToPtrType && \"No member pointer cast has a target type \" \"that is not a member pointer.\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303373/tools/clang/lib/Sema/SemaOverload.cpp"
, 2967, __PRETTY_FUNCTION__))
;
2968
2969 QualType FromClass = QualType(FromPtrType->getClass(), 0);
2970 QualType ToClass = QualType(ToPtrType->getClass(), 0);
2971
2972 // FIXME: What about dependent types?
2973 assert(FromClass->isRecordType() && "Pointer into non-class.")((FromClass->isRecordType() && "Pointer into non-class."
) ? static_cast<void> (0) : __assert_fail ("FromClass->isRecordType() && \"Pointer into non-class.\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303373/tools/clang/lib/Sema/SemaOverload.cpp"
, 2973, __PRETTY_FUNCTION__))
;
2974 assert(ToClass->isRecordType() && "Pointer into non-class.")((ToClass->isRecordType() && "Pointer into non-class."
) ? static_cast<void> (0) : __assert_fail ("ToClass->isRecordType() && \"Pointer into non-class.\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303373/tools/clang/lib/Sema/SemaOverload.cpp"
, 2974, __PRETTY_FUNCTION__))
;
2975
2976 CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
2977 /*DetectVirtual=*/true);
2978 bool DerivationOkay =
2979 IsDerivedFrom(From->getLocStart(), ToClass, FromClass, Paths);
2980 assert(DerivationOkay &&((DerivationOkay && "Should not have been called if derivation isn't OK."
) ? static_cast<void> (0) : __assert_fail ("DerivationOkay && \"Should not have been called if derivation isn't OK.\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303373/tools/clang/lib/Sema/SemaOverload.cpp"
, 2981, __PRETTY_FUNCTION__))
2981 "Should not have been called if derivation isn't OK.")((DerivationOkay && "Should not have been called if derivation isn't OK."
) ? static_cast<void> (0) : __assert_fail ("DerivationOkay && \"Should not have been called if derivation isn't OK.\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303373/tools/clang/lib/Sema/SemaOverload.cpp"
, 2981, __PRETTY_FUNCTION__))
;
2982 (void)DerivationOkay;
2983
2984 if (Paths.isAmbiguous(Context.getCanonicalType(FromClass).
2985 getUnqualifiedType())) {
2986 std::string PathDisplayStr = getAmbiguousPathsDisplayString(Paths);
2987 Diag(From->getExprLoc(), diag::err_ambiguous_memptr_conv)
2988 << 0 << FromClass << ToClass << PathDisplayStr << From->getSourceRange();
2989 return true;
2990 }
2991
2992 if (const RecordType *VBase = Paths.getDetectedVirtual()) {
2993 Diag(From->getExprLoc(), diag::err_memptr_conv_via_virtual)
2994 << FromClass << ToClass << QualType(VBase, 0)
2995 << From->getSourceRange();
2996 return true;
2997 }
2998
2999 if (!IgnoreBaseAccess)
3000 CheckBaseClassAccess(From->getExprLoc(), FromClass, ToClass,
3001 Paths.front(),
3002 diag::err_downcast_from_inaccessible_base);
3003
3004 // Must be a base to derived member conversion.
3005 BuildBasePathArray(Paths, BasePath);
3006 Kind = CK_BaseToDerivedMemberPointer;
3007 return false;
3008}
3009
3010/// Determine whether the lifetime conversion between the two given
3011/// qualifiers sets is nontrivial.
3012static bool isNonTrivialObjCLifetimeConversion(Qualifiers FromQuals,
3013 Qualifiers ToQuals) {
3014 // Converting anything to const __unsafe_unretained is trivial.
3015 if (ToQuals.hasConst() &&
3016 ToQuals.getObjCLifetime() == Qualifiers::OCL_ExplicitNone)
3017 return false;
3018
3019 return true;
3020}
3021
3022/// IsQualificationConversion - Determines whether the conversion from
3023/// an rvalue of type FromType to ToType is a qualification conversion
3024/// (C++ 4.4).
3025///
3026/// \param ObjCLifetimeConversion Output parameter that will be set to indicate
3027/// when the qualification conversion involves a change in the Objective-C
3028/// object lifetime.
3029bool
3030Sema::IsQualificationConversion(QualType FromType, QualType ToType,
3031 bool CStyle, bool &ObjCLifetimeConversion) {
3032 FromType = Context.getCanonicalType(FromType);
3033 ToType = Context.getCanonicalType(ToType);
3034 ObjCLifetimeConversion = false;
3035
3036 // If FromType and ToType are the same type, this is not a
3037 // qualification conversion.
3038 if (FromType.getUnqualifiedType() == ToType.getUnqualifiedType())
3039 return false;
3040
3041 // (C++ 4.4p4):
3042 // A conversion can add cv-qualifiers at levels other than the first
3043 // in multi-level pointers, subject to the following rules: [...]
3044 bool PreviousToQualsIncludeConst = true;
3045 bool UnwrappedAnyPointer = false;
3046 while (Context.UnwrapSimilarPointerTypes(FromType, ToType)) {
3047 // Within each iteration of the loop, we check the qualifiers to
3048 // determine if this still looks like a qualification
3049 // conversion. Then, if all is well, we unwrap one more level of
3050 // pointers or pointers-to-members and do it all again
3051 // until there are no more pointers or pointers-to-members left to
3052 // unwrap.
3053 UnwrappedAnyPointer = true;
3054
3055 Qualifiers FromQuals = FromType.getQualifiers();
3056 Qualifiers ToQuals = ToType.getQualifiers();
3057
3058 // Ignore __unaligned qualifier if this type is void.
3059 if (ToType.getUnqualifiedType()->isVoidType())
3060 FromQuals.removeUnaligned();
3061
3062 // Objective-C ARC:
3063 // Check Objective-C lifetime conversions.
3064 if (FromQuals.getObjCLifetime() != ToQuals.getObjCLifetime() &&
3065 UnwrappedAnyPointer) {
3066 if (ToQuals.compatiblyIncludesObjCLifetime(FromQuals)) {
3067 if (isNonTrivialObjCLifetimeConversion(FromQuals, ToQuals))
3068 ObjCLifetimeConversion = true;
3069 FromQuals.removeObjCLifetime();
3070 ToQuals.removeObjCLifetime();
3071 } else {
3072 // Qualification conversions cannot cast between different
3073 // Objective-C lifetime qualifiers.
3074 return false;
3075 }
3076 }
3077
3078 // Allow addition/removal of GC attributes but not changing GC attributes.
3079 if (FromQuals.getObjCGCAttr() != ToQuals.getObjCGCAttr() &&
3080 (!FromQuals.hasObjCGCAttr() || !ToQuals.hasObjCGCAttr())) {
3081 FromQuals.removeObjCGCAttr();
3082 ToQuals.removeObjCGCAttr();
3083 }
3084
3085 // -- for every j > 0, if const is in cv 1,j then const is in cv
3086 // 2,j, and similarly for volatile.
3087 if (!CStyle && !ToQuals.compatiblyIncludes(FromQuals))
3088 return false;
3089
3090 // -- if the cv 1,j and cv 2,j are different, then const is in
3091 // every cv for 0 < k < j.
3092 if (!CStyle && FromQuals.getCVRQualifiers() != ToQuals.getCVRQualifiers()
3093 && !PreviousToQualsIncludeConst)
3094 return false;
3095
3096 // Keep track of whether all prior cv-qualifiers in the "to" type
3097 // include const.
3098 PreviousToQualsIncludeConst
3099 = PreviousToQualsIncludeConst && ToQuals.hasConst();
3100 }
3101
3102 // We are left with FromType and ToType being the pointee types
3103 // after unwrapping the original FromType and ToType the same number
3104 // of types. If we unwrapped any pointers, and if FromType and
3105 // ToType have the same unqualified type (since we checked
3106 // qualifiers above), then this is a qualification conversion.
3107 return UnwrappedAnyPointer && Context.hasSameUnqualifiedType(FromType,ToType);
3108}
3109
3110/// \brief - Determine whether this is a conversion from a scalar type to an
3111/// atomic type.
3112///
3113/// If successful, updates \c SCS's second and third steps in the conversion
3114/// sequence to finish the conversion.
3115static bool tryAtomicConversion(Sema &S, Expr *From, QualType ToType,
3116 bool InOverloadResolution,
3117 StandardConversionSequence &SCS,
3118 bool CStyle) {
3119 const AtomicType *ToAtomic = ToType->getAs<AtomicType>();
3120 if (!ToAtomic)
3121 return false;
3122
3123 StandardConversionSequence InnerSCS;
3124 if (!IsStandardConversion(S, From, ToAtomic->getValueType(),
3125 InOverloadResolution, InnerSCS,
3126 CStyle, /*AllowObjCWritebackConversion=*/false))
3127 return false;
3128
3129 SCS.Second = InnerSCS.Second;
3130 SCS.setToType(1, InnerSCS.getToType(1));
3131 SCS.Third = InnerSCS.Third;
3132 SCS.QualificationIncludesObjCLifetime
3133 = InnerSCS.QualificationIncludesObjCLifetime;
3134 SCS.setToType(2, InnerSCS.getToType(2));
3135 return true;
3136}
3137
3138static bool isFirstArgumentCompatibleWithType(ASTContext &Context,
3139 CXXConstructorDecl *Constructor,
3140 QualType Type) {
3141 const FunctionProtoType *CtorType =
3142 Constructor->getType()->getAs<FunctionProtoType>();
3143 if (CtorType->getNumParams() > 0) {
3144 QualType FirstArg = CtorType->getParamType(0);
3145 if (Context.hasSameUnqualifiedType(Type, FirstArg.getNonReferenceType()))
3146 return true;
3147 }
3148 return false;
3149}
3150
3151static OverloadingResult
3152IsInitializerListConstructorConversion(Sema &S, Expr *From, QualType ToType,
3153 CXXRecordDecl *To,
3154 UserDefinedConversionSequence &User,
3155 OverloadCandidateSet &CandidateSet,
3156 bool AllowExplicit) {
3157 for (auto *D : S.LookupConstructors(To)) {
3158 auto Info = getConstructorInfo(D);
3159 if (!Info)
3160 continue;
3161
3162 bool Usable = !Info.Constructor->isInvalidDecl() &&
3163 S.isInitListConstructor(Info.Constructor) &&
3164 (AllowExplicit || !Info.Constructor->isExplicit());
3165 if (Usable) {
3166 // If the first argument is (a reference to) the target type,
3167 // suppress conversions.
3168 bool SuppressUserConversions = isFirstArgumentCompatibleWithType(
3169 S.Context, Info.Constructor, ToType);
3170 if (Info.ConstructorTmpl)
3171 S.AddTemplateOverloadCandidate(Info.ConstructorTmpl, Info.FoundDecl,
3172 /*ExplicitArgs*/ nullptr, From,
3173 CandidateSet, SuppressUserConversions);
3174 else
3175 S.AddOverloadCandidate(Info.Constructor, Info.FoundDecl, From,
3176 CandidateSet, SuppressUserConversions);
3177 }
3178 }
3179
3180 bool HadMultipleCandidates = (CandidateSet.size() > 1);
3181
3182 OverloadCandidateSet::iterator Best;
3183 switch (auto Result =
3184 CandidateSet.BestViableFunction(S, From->getLocStart(),
3185 Best, true)) {
3186 case OR_Deleted:
3187 case OR_Success: {
3188 // Record the standard conversion we used and the conversion function.
3189 CXXConstructorDecl *Constructor = cast<CXXConstructorDecl>(Best->Function);
3190 QualType ThisType = Constructor->getThisType(S.Context);
3191 // Initializer lists don't have conversions as such.
3192 User.Before.setAsIdentityConversion();
3193 User.HadMultipleCandidates = HadMultipleCandidates;
3194 User.ConversionFunction = Constructor;
3195 User.FoundConversionFunction = Best->FoundDecl;
3196 User.After.setAsIdentityConversion();
3197 User.After.setFromType(ThisType->getAs<PointerType>()->getPointeeType());
3198 User.After.setAllToTypes(ToType);
3199 return Result;
3200 }
3201
3202 case OR_No_Viable_Function:
3203 return OR_No_Viable_Function;
3204 case OR_Ambiguous:
3205 return OR_Ambiguous;
3206 }
3207
3208 llvm_unreachable("Invalid OverloadResult!")::llvm::llvm_unreachable_internal("Invalid OverloadResult!", "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303373/tools/clang/lib/Sema/SemaOverload.cpp"
, 3208)
;
3209}
3210
3211/// Determines whether there is a user-defined conversion sequence
3212/// (C++ [over.ics.user]) that converts expression From to the type
3213/// ToType. If such a conversion exists, User will contain the
3214/// user-defined conversion sequence that performs such a conversion
3215/// and this routine will return true. Otherwise, this routine returns
3216/// false and User is unspecified.
3217///
3218/// \param AllowExplicit true if the conversion should consider C++0x
3219/// "explicit" conversion functions as well as non-explicit conversion
3220/// functions (C++0x [class.conv.fct]p2).
3221///
3222/// \param AllowObjCConversionOnExplicit true if the conversion should
3223/// allow an extra Objective-C pointer conversion on uses of explicit
3224/// constructors. Requires \c AllowExplicit to also be set.
3225static OverloadingResult
3226IsUserDefinedConversion(Sema &S, Expr *From, QualType ToType,
3227 UserDefinedConversionSequence &User,
3228 OverloadCandidateSet &CandidateSet,
3229 bool AllowExplicit,
3230 bool AllowObjCConversionOnExplicit) {
3231 assert(AllowExplicit || !AllowObjCConversionOnExplicit)((AllowExplicit || !AllowObjCConversionOnExplicit) ? static_cast
<void> (0) : __assert_fail ("AllowExplicit || !AllowObjCConversionOnExplicit"
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303373/tools/clang/lib/Sema/SemaOverload.cpp"
, 3231, __PRETTY_FUNCTION__))
;
3232
3233 // Whether we will only visit constructors.
3234 bool ConstructorsOnly = false;
3235
3236 // If the type we are conversion to is a class type, enumerate its
3237 // constructors.
3238 if (const RecordType *ToRecordType = ToType->getAs<RecordType>()) {
3239 // C++ [over.match.ctor]p1:
3240 // When objects of class type are direct-initialized (8.5), or
3241 // copy-initialized from an expression of the same or a
3242 // derived class type (8.5), overload resolution selects the
3243 // constructor. [...] For copy-initialization, the candidate
3244 // functions are all the converting constructors (12.3.1) of
3245 // that class. The argument list is the expression-list within
3246 // the parentheses of the initializer.
3247 if (S.Context.hasSameUnqualifiedType(ToType, From->getType()) ||
3248 (From->getType()->getAs<RecordType>() &&
3249 S.IsDerivedFrom(From->getLocStart(), From->getType(), ToType)))
3250 ConstructorsOnly = true;
3251
3252 if (!S.isCompleteType(From->getExprLoc(), ToType)) {
3253 // We're not going to find any constructors.
3254 } else if (CXXRecordDecl *ToRecordDecl
3255 = dyn_cast<CXXRecordDecl>(ToRecordType->getDecl())) {
3256
3257 Expr **Args = &From;
3258 unsigned NumArgs = 1;
3259 bool ListInitializing = false;
3260 if (InitListExpr *InitList = dyn_cast<InitListExpr>(From)) {
3261 // But first, see if there is an init-list-constructor that will work.
3262 OverloadingResult Result = IsInitializerListConstructorConversion(
3263 S, From, ToType, ToRecordDecl, User, CandidateSet, AllowExplicit);
3264 if (Result != OR_No_Viable_Function)
3265 return Result;
3266 // Never mind.
3267 CandidateSet.clear();
3268
3269 // If we're list-initializing, we pass the individual elements as
3270 // arguments, not the entire list.
3271 Args = InitList->getInits();
3272 NumArgs = InitList->getNumInits();
3273 ListInitializing = true;
3274 }
3275
3276 for (auto *D : S.LookupConstructors(ToRecordDecl)) {
3277 auto Info = getConstructorInfo(D);
3278 if (!Info)
3279 continue;
3280
3281 bool Usable = !Info.Constructor->isInvalidDecl();
3282 if (ListInitializing)
3283 Usable = Usable && (AllowExplicit || !Info.Constructor->isExplicit());
3284 else
3285 Usable = Usable &&
3286 Info.Constructor->isConvertingConstructor(AllowExplicit);
3287 if (Usable) {
3288 bool SuppressUserConversions = !ConstructorsOnly;
3289 if (SuppressUserConversions && ListInitializing) {
3290 SuppressUserConversions = false;
3291 if (NumArgs == 1) {
3292 // If the first argument is (a reference to) the target type,
3293 // suppress conversions.
3294 SuppressUserConversions = isFirstArgumentCompatibleWithType(
3295 S.Context, Info.Constructor, ToType);
3296 }
3297 }
3298 if (Info.ConstructorTmpl)
3299 S.AddTemplateOverloadCandidate(
3300 Info.ConstructorTmpl, Info.FoundDecl,
3301 /*ExplicitArgs*/ nullptr, llvm::makeArrayRef(Args, NumArgs),
3302 CandidateSet, SuppressUserConversions);
3303 else
3304 // Allow one user-defined conversion when user specifies a
3305 // From->ToType conversion via an static cast (c-style, etc).
3306 S.AddOverloadCandidate(Info.Constructor, Info.FoundDecl,
3307 llvm::makeArrayRef(Args, NumArgs),
3308 CandidateSet, SuppressUserConversions);
3309 }
3310 }
3311 }
3312 }
3313
3314 // Enumerate conversion functions, if we're allowed to.
3315 if (ConstructorsOnly || isa<InitListExpr>(From)) {
3316 } else if (!S.isCompleteType(From->getLocStart(), From->getType())) {
3317 // No conversion functions from incomplete types.
3318 } else if (const RecordType *FromRecordType
3319 = From->getType()->getAs<RecordType>()) {
3320 if (CXXRecordDecl *FromRecordDecl
3321 = dyn_cast<CXXRecordDecl>(FromRecordType->getDecl())) {
3322 // Add all of the conversion functions as candidates.
3323 const auto &Conversions = FromRecordDecl->getVisibleConversionFunctions();
3324 for (auto I = Conversions.begin(), E = Conversions.end(); I != E; ++I) {
3325 DeclAccessPair FoundDecl = I.getPair();
3326 NamedDecl *D = FoundDecl.getDecl();
3327 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext());
3328 if (isa<UsingShadowDecl>(D))
3329 D = cast<UsingShadowDecl>(D)->getTargetDecl();
3330
3331 CXXConversionDecl *Conv;
3332 FunctionTemplateDecl *ConvTemplate;
3333 if ((ConvTemplate = dyn_cast<FunctionTemplateDecl>(D)))
3334 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl());
3335 else
3336 Conv = cast<CXXConversionDecl>(D);
3337
3338 if (AllowExplicit || !Conv->isExplicit()) {
3339 if (ConvTemplate)
3340 S.AddTemplateConversionCandidate(ConvTemplate, FoundDecl,
3341 ActingContext, From, ToType,
3342 CandidateSet,
3343 AllowObjCConversionOnExplicit);
3344 else
3345 S.AddConversionCandidate(Conv, FoundDecl, ActingContext,
3346 From, ToType, CandidateSet,
3347 AllowObjCConversionOnExplicit);
3348 }
3349 }
3350 }
3351 }
3352
3353 bool HadMultipleCandidates = (CandidateSet.size() > 1);
3354
3355 OverloadCandidateSet::iterator Best;
3356 switch (auto Result = CandidateSet.BestViableFunction(S, From->getLocStart(),
3357 Best, true)) {
3358 case OR_Success:
3359 case OR_Deleted:
3360 // Record the standard conversion we used and the conversion function.
3361 if (CXXConstructorDecl *Constructor
3362 = dyn_cast<CXXConstructorDecl>(Best->Function)) {
3363 // C++ [over.ics.user]p1:
3364 // If the user-defined conversion is specified by a
3365 // constructor (12.3.1), the initial standard conversion
3366 // sequence converts the source type to the type required by
3367 // the argument of the constructor.
3368 //
3369 QualType ThisType = Constructor->getThisType(S.Context);
3370 if (isa<InitListExpr>(From)) {
3371 // Initializer lists don't have conversions as such.
3372 User.Before.setAsIdentityConversion();
3373 } else {
3374 if (Best->Conversions[0].isEllipsis())
3375 User.EllipsisConversion = true;
3376 else {
3377 User.Before = Best->Conversions[0].Standard;
3378 User.EllipsisConversion = false;
3379 }
3380 }
3381 User.HadMultipleCandidates = HadMultipleCandidates;
3382 User.ConversionFunction = Constructor;
3383 User.FoundConversionFunction = Best->FoundDecl;
3384 User.After.setAsIdentityConversion();
3385 User.After.setFromType(ThisType->getAs<PointerType>()->getPointeeType());
3386 User.After.setAllToTypes(ToType);
3387 return Result;
3388 }
3389 if (CXXConversionDecl *Conversion
3390 = dyn_cast<CXXConversionDecl>(Best->Function)) {
3391 // C++ [over.ics.user]p1:
3392 //
3393 // [...] If the user-defined conversion is specified by a
3394 // conversion function (12.3.2), the initial standard
3395 // conversion sequence converts the source type to the
3396 // implicit object parameter of the conversion function.
3397 User.Before = Best->Conversions[0].Standard;
3398 User.HadMultipleCandidates = HadMultipleCandidates;
3399 User.ConversionFunction = Conversion;
3400 User.FoundConversionFunction = Best->FoundDecl;
3401 User.EllipsisConversion = false;
3402
3403 // C++ [over.ics.user]p2:
3404 // The second standard conversion sequence converts the
3405 // result of the user-defined conversion to the target type
3406 // for the sequence. Since an implicit conversion sequence
3407 // is an initialization, the special rules for
3408 // initialization by user-defined conversion apply when
3409 // selecting the best user-defined conversion for a
3410 // user-defined conversion sequence (see 13.3.3 and
3411 // 13.3.3.1).
3412 User.After = Best->FinalConversion;
3413 return Result;
3414 }
3415 llvm_unreachable("Not a constructor or conversion function?")::llvm::llvm_unreachable_internal("Not a constructor or conversion function?"
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303373/tools/clang/lib/Sema/SemaOverload.cpp"
, 3415)
;
3416
3417 case OR_No_Viable_Function:
3418 return OR_No_Viable_Function;
3419
3420 case OR_Ambiguous:
3421 return OR_Ambiguous;
3422 }
3423
3424 llvm_unreachable("Invalid OverloadResult!")::llvm::llvm_unreachable_internal("Invalid OverloadResult!", "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303373/tools/clang/lib/Sema/SemaOverload.cpp"
, 3424)
;
3425}
3426
3427bool
3428Sema::DiagnoseMultipleUserDefinedConversion(Expr *From, QualType ToType) {
3429 ImplicitConversionSequence ICS;
3430 OverloadCandidateSet CandidateSet(From->getExprLoc(),
3431 OverloadCandidateSet::CSK_Normal);
3432 OverloadingResult OvResult =
3433 IsUserDefinedConversion(*this, From, ToType, ICS.UserDefined,
3434 CandidateSet, false, false);
3435 if (OvResult == OR_Ambiguous)
3436 Diag(From->getLocStart(), diag::err_typecheck_ambiguous_condition)
3437 << From->getType() << ToType << From->getSourceRange();
3438 else if (OvResult == OR_No_Viable_Function && !CandidateSet.empty()) {
3439 if (!RequireCompleteType(From->getLocStart(), ToType,
3440 diag::err_typecheck_nonviable_condition_incomplete,
3441 From->getType(), From->getSourceRange()))
3442 Diag(From->getLocStart(), diag::err_typecheck_nonviable_condition)
3443 << false << From->getType() << From->getSourceRange() << ToType;
3444 } else
3445 return false;
3446 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, From);
3447 return true;
3448}
3449
3450/// \brief Compare the user-defined conversion functions or constructors
3451/// of two user-defined conversion sequences to determine whether any ordering
3452/// is possible.
3453static ImplicitConversionSequence::CompareKind
3454compareConversionFunctions(Sema &S, FunctionDecl *Function1,
3455 FunctionDecl *Function2) {
3456 if (!S.getLangOpts().ObjC1 || !S.getLangOpts().CPlusPlus11)
3457 return ImplicitConversionSequence::Indistinguishable;
3458
3459 // Objective-C++:
3460 // If both conversion functions are implicitly-declared conversions from
3461 // a lambda closure type to a function pointer and a block pointer,
3462 // respectively, always prefer the conversion to a function pointer,
3463 // because the function pointer is more lightweight and is more likely
3464 // to keep code working.
3465 CXXConversionDecl *Conv1 = dyn_cast_or_null<CXXConversionDecl>(Function1);
3466 if (!Conv1)
3467 return ImplicitConversionSequence::Indistinguishable;
3468
3469 CXXConversionDecl *Conv2 = dyn_cast<CXXConversionDecl>(Function2);
3470 if (!Conv2)
3471 return ImplicitConversionSequence::Indistinguishable;
3472
3473 if (Conv1->getParent()->isLambda() && Conv2->getParent()->isLambda()) {
3474 bool Block1 = Conv1->getConversionType()->isBlockPointerType();
3475 bool Block2 = Conv2->getConversionType()->isBlockPointerType();
3476 if (Block1 != Block2)
3477 return Block1 ? ImplicitConversionSequence::Worse
3478 : ImplicitConversionSequence::Better;
3479 }
3480
3481 return ImplicitConversionSequence::Indistinguishable;
3482}
3483
3484static bool hasDeprecatedStringLiteralToCharPtrConversion(
3485 const ImplicitConversionSequence &ICS) {
3486 return (ICS.isStandard() && ICS.Standard.DeprecatedStringLiteralToCharPtr) ||
3487 (ICS.isUserDefined() &&
3488 ICS.UserDefined.Before.DeprecatedStringLiteralToCharPtr);
3489}
3490
3491/// CompareImplicitConversionSequences - Compare two implicit
3492/// conversion sequences to determine whether one is better than the
3493/// other or if they are indistinguishable (C++ 13.3.3.2).
3494static ImplicitConversionSequence::CompareKind
3495CompareImplicitConversionSequences(Sema &S, SourceLocation Loc,
3496 const ImplicitConversionSequence& ICS1,
3497 const ImplicitConversionSequence& ICS2)
3498{
3499 // (C++ 13.3.3.2p2): When comparing the basic forms of implicit
3500 // conversion sequences (as defined in 13.3.3.1)
3501 // -- a standard conversion sequence (13.3.3.1.1) is a better
3502 // conversion sequence than a user-defined conversion sequence or
3503 // an ellipsis conversion sequence, and
3504 // -- a user-defined conversion sequence (13.3.3.1.2) is a better
3505 // conversion sequence than an ellipsis conversion sequence
3506 // (13.3.3.1.3).
3507 //
3508 // C++0x [over.best.ics]p10:
3509 // For the purpose of ranking implicit conversion sequences as
3510 // described in 13.3.3.2, the ambiguous conversion sequence is
3511 // treated as a user-defined sequence that is indistinguishable
3512 // from any other user-defined conversion sequence.
3513
3514 // String literal to 'char *' conversion has been deprecated in C++03. It has
3515 // been removed from C++11. We still accept this conversion, if it happens at
3516 // the best viable function. Otherwise, this conversion is considered worse
3517 // than ellipsis conversion. Consider this as an extension; this is not in the
3518 // standard. For example:
3519 //
3520 // int &f(...); // #1
3521 // void f(char*); // #2
3522 // void g() { int &r = f("foo"); }
3523 //
3524 // In C++03, we pick #2 as the best viable function.
3525 // In C++11, we pick #1 as the best viable function, because ellipsis
3526 // conversion is better than string-literal to char* conversion (since there
3527 // is no such conversion in C++11). If there was no #1 at all or #1 couldn't
3528 // convert arguments, #2 would be the best viable function in C++11.
3529 // If the best viable function has this conversion, a warning will be issued
3530 // in C++03, or an ExtWarn (+SFINAE failure) will be issued in C++11.
3531
3532 if (S.getLangOpts().CPlusPlus11 && !S.getLangOpts().WritableStrings &&
3533 hasDeprecatedStringLiteralToCharPtrConversion(ICS1) !=
3534 hasDeprecatedStringLiteralToCharPtrConversion(ICS2))
3535 return hasDeprecatedStringLiteralToCharPtrConversion(ICS1)
3536 ? ImplicitConversionSequence::Worse
3537 : ImplicitConversionSequence::Better;
3538
3539 if (ICS1.getKindRank() < ICS2.getKindRank())
3540 return ImplicitConversionSequence::Better;
3541 if (ICS2.getKindRank() < ICS1.getKindRank())
3542 return ImplicitConversionSequence::Worse;
3543
3544 // The following checks require both conversion sequences to be of
3545 // the same kind.
3546 if (ICS1.getKind() != ICS2.getKind())
3547 return ImplicitConversionSequence::Indistinguishable;
3548
3549 ImplicitConversionSequence::CompareKind Result =
3550 ImplicitConversionSequence::Indistinguishable;
3551
3552 // Two implicit conversion sequences of the same form are
3553 // indistinguishable conversion sequences unless one of the
3554 // following rules apply: (C++ 13.3.3.2p3):
3555
3556 // List-initialization sequence L1 is a better conversion sequence than
3557 // list-initialization sequence L2 if:
3558 // - L1 converts to std::initializer_list<X> for some X and L2 does not, or,
3559 // if not that,
3560 // - L1 converts to type "array of N1 T", L2 converts to type "array of N2 T",
3561 // and N1 is smaller than N2.,
3562 // even if one of the other rules in this paragraph would otherwise apply.
3563 if (!ICS1.isBad()) {
3564 if (ICS1.isStdInitializerListElement() &&
3565 !ICS2.isStdInitializerListElement())
3566 return ImplicitConversionSequence::Better;
3567 if (!ICS1.isStdInitializerListElement() &&
3568 ICS2.isStdInitializerListElement())
3569 return ImplicitConversionSequence::Worse;
3570 }
3571
3572 if (ICS1.isStandard())
3573 // Standard conversion sequence S1 is a better conversion sequence than
3574 // standard conversion sequence S2 if [...]
3575 Result = CompareStandardConversionSequences(S, Loc,
3576 ICS1.Standard, ICS2.Standard);
3577 else if (ICS1.isUserDefined()) {
3578 // User-defined conversion sequence U1 is a better conversion
3579 // sequence than another user-defined conversion sequence U2 if
3580 // they contain the same user-defined conversion function or
3581 // constructor and if the second standard conversion sequence of
3582 // U1 is better than the second standard conversion sequence of
3583 // U2 (C++ 13.3.3.2p3).
3584 if (ICS1.UserDefined.ConversionFunction ==
3585 ICS2.UserDefined.ConversionFunction)
3586 Result = CompareStandardConversionSequences(S, Loc,
3587 ICS1.UserDefined.After,
3588 ICS2.UserDefined.After);
3589 else
3590 Result = compareConversionFunctions(S,
3591 ICS1.UserDefined.ConversionFunction,
3592 ICS2.UserDefined.ConversionFunction);
3593 }
3594
3595 return Result;
3596}
3597
3598static bool hasSimilarType(ASTContext &Context, QualType T1, QualType T2) {
3599 while (Context.UnwrapSimilarPointerTypes(T1, T2)) {
3600 Qualifiers Quals;
3601 T1 = Context.getUnqualifiedArrayType(T1, Quals);
3602 T2 = Context.getUnqualifiedArrayType(T2, Quals);
3603 }
3604
3605 return Context.hasSameUnqualifiedType(T1, T2);
3606}
3607
3608// Per 13.3.3.2p3, compare the given standard conversion sequences to
3609// determine if one is a proper subset of the other.
3610static ImplicitConversionSequence::CompareKind
3611compareStandardConversionSubsets(ASTContext &Context,
3612 const StandardConversionSequence& SCS1,
3613 const StandardConversionSequence& SCS2) {
3614 ImplicitConversionSequence::CompareKind Result
3615 = ImplicitConversionSequence::Indistinguishable;
3616
3617 // the identity conversion sequence is considered to be a subsequence of
3618 // any non-identity conversion sequence
3619 if (SCS1.isIdentityConversion() && !SCS2.isIdentityConversion())
3620 return ImplicitConversionSequence::Better;
3621 else if (!SCS1.isIdentityConversion() && SCS2.isIdentityConversion())
3622 return ImplicitConversionSequence::Worse;
3623
3624 if (SCS1.Second != SCS2.Second) {
3625 if (SCS1.Second == ICK_Identity)
3626 Result = ImplicitConversionSequence::Better;
3627 else if (SCS2.Second == ICK_Identity)
3628 Result = ImplicitConversionSequence::Worse;
3629 else
3630 return ImplicitConversionSequence::Indistinguishable;
3631 } else if (!hasSimilarType(Context, SCS1.getToType(1), SCS2.getToType(1)))
3632 return ImplicitConversionSequence::Indistinguishable;
3633
3634 if (SCS1.Third == SCS2.Third) {
3635 return Context.hasSameType(SCS1.getToType(2), SCS2.getToType(2))? Result
3636 : ImplicitConversionSequence::Indistinguishable;
3637 }
3638
3639 if (SCS1.Third == ICK_Identity)
3640 return Result == ImplicitConversionSequence::Worse
3641 ? ImplicitConversionSequence::Indistinguishable
3642 : ImplicitConversionSequence::Better;
3643
3644 if (SCS2.Third == ICK_Identity)
3645 return Result == ImplicitConversionSequence::Better
3646 ? ImplicitConversionSequence::Indistinguishable
3647 : ImplicitConversionSequence::Worse;
3648
3649 return ImplicitConversionSequence::Indistinguishable;
3650}
3651
3652/// \brief Determine whether one of the given reference bindings is better
3653/// than the other based on what kind of bindings they are.
3654static bool
3655isBetterReferenceBindingKind(const StandardConversionSequence &SCS1,
3656 const StandardConversionSequence &SCS2) {
3657 // C++0x [over.ics.rank]p3b4:
3658 // -- S1 and S2 are reference bindings (8.5.3) and neither refers to an
3659 // implicit object parameter of a non-static member function declared
3660 // without a ref-qualifier, and *either* S1 binds an rvalue reference
3661 // to an rvalue and S2 binds an lvalue reference *or S1 binds an
3662 // lvalue reference to a function lvalue and S2 binds an rvalue
3663 // reference*.
3664 //
3665 // FIXME: Rvalue references. We're going rogue with the above edits,
3666 // because the semantics in the current C++0x working paper (N3225 at the
3667 // time of this writing) break the standard definition of std::forward
3668 // and std::reference_wrapper when dealing with references to functions.
3669 // Proposed wording changes submitted to CWG for consideration.
3670 if (SCS1.BindsImplicitObjectArgumentWithoutRefQualifier ||
3671 SCS2.BindsImplicitObjectArgumentWithoutRefQualifier)
3672 return false;
3673
3674 return (!SCS1.IsLvalueReference && SCS1.BindsToRvalue &&
3675 SCS2.IsLvalueReference) ||
3676 (SCS1.IsLvalueReference && SCS1.BindsToFunctionLvalue &&
3677 !SCS2.IsLvalueReference && SCS2.BindsToFunctionLvalue);
3678}
3679
3680/// CompareStandardConversionSequences - Compare two standard
3681/// conversion sequences to determine whether one is better than the
3682/// other or if they are indistinguishable (C++ 13.3.3.2p3).
3683static ImplicitConversionSequence::CompareKind
3684CompareStandardConversionSequences(Sema &S, SourceLocation Loc,
3685 const StandardConversionSequence& SCS1,
3686 const StandardConversionSequence& SCS2)
3687{
3688 // Standard conversion sequence S1 is a better conversion sequence
3689 // than standard conversion sequence S2 if (C++ 13.3.3.2p3):
3690
3691 // -- S1 is a proper subsequence of S2 (comparing the conversion
3692 // sequences in the canonical form defined by 13.3.3.1.1,
3693 // excluding any Lvalue Transformation; the identity conversion
3694 // sequence is considered to be a subsequence of any
3695 // non-identity conversion sequence) or, if not that,
3696 if (ImplicitConversionSequence::CompareKind CK
3697 = compareStandardConversionSubsets(S.Context, SCS1, SCS2))
3698 return CK;
3699
3700 // -- the rank of S1 is better than the rank of S2 (by the rules
3701 // defined below), or, if not that,
3702 ImplicitConversionRank Rank1 = SCS1.getRank();
3703 ImplicitConversionRank Rank2 = SCS2.getRank();
3704 if (Rank1 < Rank2)
3705 return ImplicitConversionSequence::Better;
3706 else if (Rank2 < Rank1)
3707 return ImplicitConversionSequence::Worse;
3708
3709 // (C++ 13.3.3.2p4): Two conversion sequences with the same rank
3710 // are indistinguishable unless one of the following rules
3711 // applies:
3712
3713 // A conversion that is not a conversion of a pointer, or
3714 // pointer to member, to bool is better than another conversion
3715 // that is such a conversion.
3716 if (SCS1.isPointerConversionToBool() != SCS2.isPointerConversionToBool())
3717 return SCS2.isPointerConversionToBool()
3718 ? ImplicitConversionSequence::Better
3719 : ImplicitConversionSequence::Worse;
3720
3721 // C++ [over.ics.rank]p4b2:
3722 //
3723 // If class B is derived directly or indirectly from class A,
3724 // conversion of B* to A* is better than conversion of B* to
3725 // void*, and conversion of A* to void* is better than conversion
3726 // of B* to void*.
3727 bool SCS1ConvertsToVoid
3728 = SCS1.isPointerConversionToVoidPointer(S.Context);
3729 bool SCS2ConvertsToVoid
3730 = SCS2.isPointerConversionToVoidPointer(S.Context);
3731 if (SCS1ConvertsToVoid != SCS2ConvertsToVoid) {
3732 // Exactly one of the conversion sequences is a conversion to
3733 // a void pointer; it's the worse conversion.
3734 return SCS2ConvertsToVoid ? ImplicitConversionSequence::Better
3735 : ImplicitConversionSequence::Worse;
3736 } else if (!SCS1ConvertsToVoid && !SCS2ConvertsToVoid) {
3737 // Neither conversion sequence converts to a void pointer; compare
3738 // their derived-to-base conversions.
3739 if (ImplicitConversionSequence::CompareKind DerivedCK
3740 = CompareDerivedToBaseConversions(S, Loc, SCS1, SCS2))
3741 return DerivedCK;
3742 } else if (SCS1ConvertsToVoid && SCS2ConvertsToVoid &&
3743 !S.Context.hasSameType(SCS1.getFromType(), SCS2.getFromType())) {
3744 // Both conversion sequences are conversions to void
3745 // pointers. Compare the source types to determine if there's an
3746 // inheritance relationship in their sources.
3747 QualType FromType1 = SCS1.getFromType();
3748 QualType FromType2 = SCS2.getFromType();
3749
3750 // Adjust the types we're converting from via the array-to-pointer
3751 // conversion, if we need to.
3752 if (SCS1.First == ICK_Array_To_Pointer)
3753 FromType1 = S.Context.getArrayDecayedType(FromType1);
3754 if (SCS2.First == ICK_Array_To_Pointer)
3755 FromType2 = S.Context.getArrayDecayedType(FromType2);
3756
3757 QualType FromPointee1 = FromType1->getPointeeType().getUnqualifiedType();
3758 QualType FromPointee2 = FromType2->getPointeeType().getUnqualifiedType();
3759
3760 if (S.IsDerivedFrom(Loc, FromPointee2, FromPointee1))
3761 return ImplicitConversionSequence::Better;
3762 else if (S.IsDerivedFrom(Loc, FromPointee1, FromPointee2))
3763 return ImplicitConversionSequence::Worse;
3764
3765 // Objective-C++: If one interface is more specific than the
3766 // other, it is the better one.
3767 const ObjCObjectPointerType* FromObjCPtr1
3768 = FromType1->getAs<ObjCObjectPointerType>();
3769 const ObjCObjectPointerType* FromObjCPtr2
3770 = FromType2->getAs<ObjCObjectPointerType>();
3771 if (FromObjCPtr1 && FromObjCPtr2) {
3772 bool AssignLeft = S.Context.canAssignObjCInterfaces(FromObjCPtr1,
3773 FromObjCPtr2);
3774 bool AssignRight = S.Context.canAssignObjCInterfaces(FromObjCPtr2,
3775 FromObjCPtr1);
3776 if (AssignLeft != AssignRight) {
3777 return AssignLeft? ImplicitConversionSequence::Better
3778 : ImplicitConversionSequence::Worse;
3779 }
3780 }
3781 }
3782
3783 // Compare based on qualification conversions (C++ 13.3.3.2p3,
3784 // bullet 3).
3785 if (ImplicitConversionSequence::CompareKind QualCK
3786 = CompareQualificationConversions(S, SCS1, SCS2))
3787 return QualCK;
3788
3789 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding) {
3790 // Check for a better reference binding based on the kind of bindings.
3791 if (isBetterReferenceBindingKind(SCS1, SCS2))
3792 return ImplicitConversionSequence::Better;
3793 else if (isBetterReferenceBindingKind(SCS2, SCS1))
3794 return ImplicitConversionSequence::Worse;
3795
3796 // C++ [over.ics.rank]p3b4:
3797 // -- S1 and S2 are reference bindings (8.5.3), and the types to
3798 // which the references refer are the same type except for
3799 // top-level cv-qualifiers, and the type to which the reference
3800 // initialized by S2 refers is more cv-qualified than the type
3801 // to which the reference initialized by S1 refers.
3802 QualType T1 = SCS1.getToType(2);
3803 QualType T2 = SCS2.getToType(2);
3804 T1 = S.Context.getCanonicalType(T1);
3805 T2 = S.Context.getCanonicalType(T2);
3806 Qualifiers T1Quals, T2Quals;
3807 QualType UnqualT1 = S.Context.getUnqualifiedArrayType(T1, T1Quals);
3808 QualType UnqualT2 = S.Context.getUnqualifiedArrayType(T2, T2Quals);
3809 if (UnqualT1 == UnqualT2) {
3810 // Objective-C++ ARC: If the references refer to objects with different
3811 // lifetimes, prefer bindings that don't change lifetime.
3812 if (SCS1.ObjCLifetimeConversionBinding !=
3813 SCS2.ObjCLifetimeConversionBinding) {
3814 return SCS1.ObjCLifetimeConversionBinding
3815 ? ImplicitConversionSequence::Worse
3816 : ImplicitConversionSequence::Better;
3817 }
3818
3819 // If the type is an array type, promote the element qualifiers to the
3820 // type for comparison.
3821 if (isa<ArrayType>(T1) && T1Quals)
3822 T1 = S.Context.getQualifiedType(UnqualT1, T1Quals);
3823 if (isa<ArrayType>(T2) && T2Quals)
3824 T2 = S.Context.getQualifiedType(UnqualT2, T2Quals);
3825 if (T2.isMoreQualifiedThan(T1))
3826 return ImplicitConversionSequence::Better;
3827 else if (T1.isMoreQualifiedThan(T2))
3828 return ImplicitConversionSequence::Worse;
3829 }
3830 }
3831
3832 // In Microsoft mode, prefer an integral conversion to a
3833 // floating-to-integral conversion if the integral conversion
3834 // is between types of the same size.
3835 // For example:
3836 // void f(float);
3837 // void f(int);
3838 // int main {
3839 // long a;
3840 // f(a);
3841 // }
3842 // Here, MSVC will call f(int) instead of generating a compile error
3843 // as clang will do in standard mode.
3844 if (S.getLangOpts().MSVCCompat && SCS1.Second == ICK_Integral_Conversion &&
3845 SCS2.Second == ICK_Floating_Integral &&
3846 S.Context.getTypeSize(SCS1.getFromType()) ==
3847 S.Context.getTypeSize(SCS1.getToType(2)))
3848 return ImplicitConversionSequence::Better;
3849
3850 return ImplicitConversionSequence::Indistinguishable;
3851}
3852
3853/// CompareQualificationConversions - Compares two standard conversion
3854/// sequences to determine whether they can be ranked based on their
3855/// qualification conversions (C++ 13.3.3.2p3 bullet 3).
3856static ImplicitConversionSequence::CompareKind
3857CompareQualificationConversions(Sema &S,
3858 const StandardConversionSequence& SCS1,
3859 const StandardConversionSequence& SCS2) {
3860 // C++ 13.3.3.2p3:
3861 // -- S1 and S2 differ only in their qualification conversion and
3862 // yield similar types T1 and T2 (C++ 4.4), respectively, and the
3863 // cv-qualification signature of type T1 is a proper subset of
3864 // the cv-qualification signature of type T2, and S1 is not the
3865 // deprecated string literal array-to-pointer conversion (4.2).
3866 if (SCS1.First != SCS2.First || SCS1.Second != SCS2.Second ||
3867 SCS1.Third != SCS2.Third || SCS1.Third != ICK_Qualification)
3868 return ImplicitConversionSequence::Indistinguishable;
3869
3870 // FIXME: the example in the standard doesn't use a qualification
3871 // conversion (!)
3872 QualType T1 = SCS1.getToType(2);
3873 QualType T2 = SCS2.getToType(2);
3874 T1 = S.Context.getCanonicalType(T1);
3875 T2 = S.Context.getCanonicalType(T2);
3876 Qualifiers T1Quals, T2Quals;
3877 QualType UnqualT1 = S.Context.getUnqualifiedArrayType(T1, T1Quals);
3878 QualType UnqualT2 = S.Context.getUnqualifiedArrayType(T2, T2Quals);
3879
3880 // If the types are the same, we won't learn anything by unwrapped
3881 // them.
3882 if (UnqualT1 == UnqualT2)
3883 return ImplicitConversionSequence::Indistinguishable;
3884
3885 // If the type is an array type, promote the element qualifiers to the type
3886 // for comparison.
3887 if (isa<ArrayType>(T1) && T1Quals)
3888 T1 = S.Context.getQualifiedType(UnqualT1, T1Quals);
3889 if (isa<ArrayType>(T2) && T2Quals)
3890 T2 = S.Context.getQualifiedType(UnqualT2, T2Quals);
3891
3892 ImplicitConversionSequence::CompareKind Result
3893 = ImplicitConversionSequence::Indistinguishable;
3894
3895 // Objective-C++ ARC:
3896 // Prefer qualification conversions not involving a change in lifetime
3897 // to qualification conversions that do not change lifetime.
3898 if (SCS1.QualificationIncludesObjCLifetime !=
3899 SCS2.QualificationIncludesObjCLifetime) {
3900 Result = SCS1.QualificationIncludesObjCLifetime
3901 ? ImplicitConversionSequence::Worse
3902 : ImplicitConversionSequence::Better;
3903 }
3904
3905 while (S.Context.UnwrapSimilarPointerTypes(T1, T2)) {
3906 // Within each iteration of the loop, we check the qualifiers to
3907 // determine if this still looks like a qualification
3908 // conversion. Then, if all is well, we unwrap one more level of
3909 // pointers or pointers-to-members and do it all again
3910 // until there are no more pointers or pointers-to-members left
3911 // to unwrap. This essentially mimics what
3912 // IsQualificationConversion does, but here we're checking for a
3913 // strict subset of qualifiers.
3914 if (T1.getCVRQualifiers() == T2.getCVRQualifiers())
3915 // The qualifiers are the same, so this doesn't tell us anything
3916 // about how the sequences rank.
3917 ;
3918 else if (T2.isMoreQualifiedThan(T1)) {
3919 // T1 has fewer qualifiers, so it could be the better sequence.
3920 if (Result == ImplicitConversionSequence::Worse)
3921 // Neither has qualifiers that are a subset of the other's
3922 // qualifiers.
3923 return ImplicitConversionSequence::Indistinguishable;
3924
3925 Result = ImplicitConversionSequence::Better;
3926 } else if (T1.isMoreQualifiedThan(T2)) {
3927 // T2 has fewer qualifiers, so it could be the better sequence.
3928 if (Result == ImplicitConversionSequence::Better)
3929 // Neither has qualifiers that are a subset of the other's
3930 // qualifiers.
3931 return ImplicitConversionSequence::Indistinguishable;
3932
3933 Result = ImplicitConversionSequence::Worse;
3934 } else {
3935 // Qualifiers are disjoint.
3936 return ImplicitConversionSequence::Indistinguishable;
3937 }
3938
3939 // If the types after this point are equivalent, we're done.
3940 if (S.Context.hasSameUnqualifiedType(T1, T2))
3941 break;
3942 }
3943
3944 // Check that the winning standard conversion sequence isn't using
3945 // the deprecated string literal array to pointer conversion.
3946 switch (Result) {
3947 case ImplicitConversionSequence::Better:
3948 if (SCS1.DeprecatedStringLiteralToCharPtr)
3949 Result = ImplicitConversionSequence::Indistinguishable;
3950 break;
3951
3952 case ImplicitConversionSequence::Indistinguishable:
3953 break;
3954
3955 case ImplicitConversionSequence::Worse:
3956 if (SCS2.DeprecatedStringLiteralToCharPtr)
3957 Result = ImplicitConversionSequence::Indistinguishable;
3958 break;
3959 }
3960
3961 return Result;
3962}
3963
3964/// CompareDerivedToBaseConversions - Compares two standard conversion
3965/// sequences to determine whether they can be ranked based on their
3966/// various kinds of derived-to-base conversions (C++
3967/// [over.ics.rank]p4b3). As part of these checks, we also look at
3968/// conversions between Objective-C interface types.
3969static ImplicitConversionSequence::CompareKind
3970CompareDerivedToBaseConversions(Sema &S, SourceLocation Loc,
3971 const StandardConversionSequence& SCS1,
3972 const StandardConversionSequence& SCS2) {
3973 QualType FromType1 = SCS1.getFromType();
3974 QualType ToType1 = SCS1.getToType(1);
3975 QualType FromType2 = SCS2.getFromType();
3976 QualType ToType2 = SCS2.getToType(1);
3977
3978 // Adjust the types we're converting from via the array-to-pointer
3979 // conversion, if we need to.
3980 if (SCS1.First == ICK_Array_To_Pointer)
3981 FromType1 = S.Context.getArrayDecayedType(FromType1);
3982 if (SCS2.First == ICK_Array_To_Pointer)
3983 FromType2 = S.Context.getArrayDecayedType(FromType2);
3984
3985 // Canonicalize all of the types.
3986 FromType1 = S.Context.getCanonicalType(FromType1);
3987 ToType1 = S.Context.getCanonicalType(ToType1);
3988 FromType2 = S.Context.getCanonicalType(FromType2);
3989 ToType2 = S.Context.getCanonicalType(ToType2);
3990
3991 // C++ [over.ics.rank]p4b3:
3992 //
3993 // If class B is derived directly or indirectly from class A and
3994 // class C is derived directly or indirectly from B,
3995 //
3996 // Compare based on pointer conversions.
3997 if (SCS1.Second == ICK_Pointer_Conversion &&
3998 SCS2.Second == ICK_Pointer_Conversion &&
3999 /*FIXME: Remove if Objective-C id conversions get their own rank*/
4000 FromType1->isPointerType() && FromType2->isPointerType() &&
4001 ToType1->isPointerType() && ToType2->isPointerType()) {
4002 QualType FromPointee1
4003 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType();
4004 QualType ToPointee1
4005 = ToType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType();
4006 QualType FromPointee2
4007 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType();
4008 QualType ToPointee2
4009 = ToType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType();
4010
4011 // -- conversion of C* to B* is better than conversion of C* to A*,
4012 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) {
4013 if (S.IsDerivedFrom(Loc, ToPointee1, ToPointee2))
4014 return ImplicitConversionSequence::Better;
4015 else if (S.IsDerivedFrom(Loc, ToPointee2, ToPointee1))
4016 return ImplicitConversionSequence::Worse;
4017 }
4018
4019 // -- conversion of B* to A* is better than conversion of C* to A*,
4020 if (FromPointee1 != FromPointee2 && ToPointee1 == ToPointee2) {
4021 if (S.IsDerivedFrom(Loc, FromPointee2, FromPointee1))
4022 return ImplicitConversionSequence::Better;
4023 else if (S.IsDerivedFrom(Loc, FromPointee1, FromPointee2))
4024 return ImplicitConversionSequence::Worse;
4025 }
4026 } else if (SCS1.Second == ICK_Pointer_Conversion &&
4027 SCS2.Second == ICK_Pointer_Conversion) {
4028 const ObjCObjectPointerType *FromPtr1
4029 = FromType1->getAs<ObjCObjectPointerType>();
4030 const ObjCObjectPointerType *FromPtr2
4031 = FromType2->getAs<ObjCObjectPointerType>();
4032 const ObjCObjectPointerType *ToPtr1
4033 = ToType1->getAs<ObjCObjectPointerType>();
4034 const ObjCObjectPointerType *ToPtr2
4035 = ToType2->getAs<ObjCObjectPointerType>();
4036
4037 if (FromPtr1 && FromPtr2 && ToPtr1 && ToPtr2) {
4038 // Apply the same conversion ranking rules for Objective-C pointer types
4039 // that we do for C++ pointers to class types. However, we employ the
4040 // Objective-C pseudo-subtyping relationship used for assignment of
4041 // Objective-C pointer types.
4042 bool FromAssignLeft
4043 = S.Context.canAssignObjCInterfaces(FromPtr1, FromPtr2);
4044 bool FromAssignRight
4045 = S.Context.canAssignObjCInterfaces(FromPtr2, FromPtr1);
4046 bool ToAssignLeft
4047 = S.Context.canAssignObjCInterfaces(ToPtr1, ToPtr2);
4048 bool ToAssignRight
4049 = S.Context.canAssignObjCInterfaces(ToPtr2, ToPtr1);
4050
4051 // A conversion to an a non-id object pointer type or qualified 'id'
4052 // type is better than a conversion to 'id'.
4053 if (ToPtr1->isObjCIdType() &&
4054 (ToPtr2->isObjCQualifiedIdType() || ToPtr2->getInterfaceDecl()))
4055 return ImplicitConversionSequence::Worse;
4056 if (ToPtr2->isObjCIdType() &&
4057 (ToPtr1->isObjCQualifiedIdType() || ToPtr1->getInterfaceDecl()))
4058 return ImplicitConversionSequence::Better;
4059
4060 // A conversion to a non-id object pointer type is better than a
4061 // conversion to a qualified 'id' type
4062 if (ToPtr1->isObjCQualifiedIdType() && ToPtr2->getInterfaceDecl())
4063 return ImplicitConversionSequence::Worse;
4064 if (ToPtr2->isObjCQualifiedIdType() && ToPtr1->getInterfaceDecl())
4065 return ImplicitConversionSequence::Better;
4066
4067 // A conversion to an a non-Class object pointer type or qualified 'Class'
4068 // type is better than a conversion to 'Class'.
4069 if (ToPtr1->isObjCClassType() &&
4070 (ToPtr2->isObjCQualifiedClassType() || ToPtr2->getInterfaceDecl()))
4071 return ImplicitConversionSequence::Worse;
4072 if (ToPtr2->isObjCClassType() &&
4073 (ToPtr1->isObjCQualifiedClassType() || ToPtr1->getInterfaceDecl()))
4074 return ImplicitConversionSequence::Better;
4075
4076 // A conversion to a non-Class object pointer type is better than a
4077 // conversion to a qualified 'Class' type.
4078 if (ToPtr1->isObjCQualifiedClassType() && ToPtr2->getInterfaceDecl())
4079 return ImplicitConversionSequence::Worse;
4080 if (ToPtr2->isObjCQualifiedClassType() && ToPtr1->getInterfaceDecl())
4081 return ImplicitConversionSequence::Better;
4082
4083 // -- "conversion of C* to B* is better than conversion of C* to A*,"
4084 if (S.Context.hasSameType(FromType1, FromType2) &&
4085 !FromPtr1->isObjCIdType() && !FromPtr1->isObjCClassType() &&
4086 (ToAssignLeft != ToAssignRight)) {
4087 if (FromPtr1->isSpecialized()) {
4088 // "conversion of B<A> * to B * is better than conversion of B * to
4089 // C *.
4090 bool IsFirstSame =
4091 FromPtr1->getInterfaceDecl() == ToPtr1->getInterfaceDecl();
4092 bool IsSecondSame =
4093 FromPtr1->getInterfaceDecl() == ToPtr2->getInterfaceDecl();
4094 if (IsFirstSame) {
4095 if (!IsSecondSame)
4096 return ImplicitConversionSequence::Better;
4097 } else if (IsSecondSame)
4098 return ImplicitConversionSequence::Worse;
4099 }
4100 return ToAssignLeft? ImplicitConversionSequence::Worse
4101 : ImplicitConversionSequence::Better;
4102 }
4103
4104 // -- "conversion of B* to A* is better than conversion of C* to A*,"
4105 if (S.Context.hasSameUnqualifiedType(ToType1, ToType2) &&
4106 (FromAssignLeft != FromAssignRight))
4107 return FromAssignLeft? ImplicitConversionSequence::Better
4108 : ImplicitConversionSequence::Worse;
4109 }
4110 }
4111
4112 // Ranking of member-pointer types.
4113 if (SCS1.Second == ICK_Pointer_Member && SCS2.Second == ICK_Pointer_Member &&
4114 FromType1->isMemberPointerType() && FromType2->isMemberPointerType() &&
4115 ToType1->isMemberPointerType() && ToType2->isMemberPointerType()) {
4116 const MemberPointerType * FromMemPointer1 =
4117 FromType1->getAs<MemberPointerType>();
4118 const MemberPointerType * ToMemPointer1 =
4119 ToType1->getAs<MemberPointerType>();
4120 const MemberPointerType * FromMemPointer2 =
4121 FromType2->getAs<MemberPointerType>();
4122 const MemberPointerType * ToMemPointer2 =
4123 ToType2->getAs<MemberPointerType>();
4124 const Type *FromPointeeType1 = FromMemPointer1->getClass();
4125 const Type *ToPointeeType1 = ToMemPointer1->getClass();
4126 const Type *FromPointeeType2 = FromMemPointer2->getClass();
4127 const Type *ToPointeeType2 = ToMemPointer2->getClass();
4128 QualType FromPointee1 = QualType(FromPointeeType1, 0).getUnqualifiedType();
4129 QualType ToPointee1 = QualType(ToPointeeType1, 0).getUnqualifiedType();
4130 QualType FromPointee2 = QualType(FromPointeeType2, 0).getUnqualifiedType();
4131 QualType ToPointee2 = QualType(ToPointeeType2, 0).getUnqualifiedType();
4132 // conversion of A::* to B::* is better than conversion of A::* to C::*,
4133 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) {
4134 if (S.IsDerivedFrom(Loc, ToPointee1, ToPointee2))
4135 return ImplicitConversionSequence::Worse;
4136 else if (S.IsDerivedFrom(Loc, ToPointee2, ToPointee1))
4137 return ImplicitConversionSequence::Better;
4138 }
4139 // conversion of B::* to C::* is better than conversion of A::* to C::*
4140 if (ToPointee1 == ToPointee2 && FromPointee1 != FromPointee2) {
4141 if (S.IsDerivedFrom(Loc, FromPointee1, FromPointee2))
4142 return ImplicitConversionSequence::Better;
4143 else if (S.IsDerivedFrom(Loc, FromPointee2, FromPointee1))
4144 return ImplicitConversionSequence::Worse;
4145 }
4146 }
4147
4148 if (SCS1.Second == ICK_Derived_To_Base) {
4149 // -- conversion of C to B is better than conversion of C to A,
4150 // -- binding of an expression of type C to a reference of type
4151 // B& is better than binding an expression of type C to a
4152 // reference of type A&,
4153 if (S.Context.hasSameUnqualifiedType(FromType1, FromType2) &&
4154 !S.Context.hasSameUnqualifiedType(ToType1, ToType2)) {
4155 if (S.IsDerivedFrom(Loc, ToType1, ToType2))
4156 return ImplicitConversionSequence::Better;
4157 else if (S.IsDerivedFrom(Loc, ToType2, ToType1))
4158 return ImplicitConversionSequence::Worse;
4159 }
4160
4161 // -- conversion of B to A is better than conversion of C to A.
4162 // -- binding of an expression of type B to a reference of type
4163 // A& is better than binding an expression of type C to a
4164 // reference of type A&,
4165 if (!S.Context.hasSameUnqualifiedType(FromType1, FromType2) &&
4166 S.Context.hasSameUnqualifiedType(ToType1, ToType2)) {
4167 if (S.IsDerivedFrom(Loc, FromType2, FromType1))
4168 return ImplicitConversionSequence::Better;
4169 else if (S.IsDerivedFrom(Loc, FromType1, FromType2))
4170 return ImplicitConversionSequence::Worse;
4171 }
4172 }
4173
4174 return ImplicitConversionSequence::Indistinguishable;
4175}
4176
4177/// \brief Determine whether the given type is valid, e.g., it is not an invalid
4178/// C++ class.
4179static bool isTypeValid(QualType T) {
4180 if (CXXRecordDecl *Record = T->getAsCXXRecordDecl())
4181 return !Record->isInvalidDecl();
4182
4183 return true;
4184}
4185
4186/// CompareReferenceRelationship - Compare the two types T1 and T2 to
4187/// determine whether they are reference-related,
4188/// reference-compatible, reference-compatible with added
4189/// qualification, or incompatible, for use in C++ initialization by
4190/// reference (C++ [dcl.ref.init]p4). Neither type can be a reference
4191/// type, and the first type (T1) is the pointee type of the reference
4192/// type being initialized.
4193Sema::ReferenceCompareResult
4194Sema::CompareReferenceRelationship(SourceLocation Loc,
4195 QualType OrigT1, QualType OrigT2,
4196 bool &DerivedToBase,
4197 bool &ObjCConversion,
4198 bool &ObjCLifetimeConversion) {
4199 assert(!OrigT1->isReferenceType() &&((!OrigT1->isReferenceType() && "T1 must be the pointee type of the reference type"
) ? static_cast<void> (0) : __assert_fail ("!OrigT1->isReferenceType() && \"T1 must be the pointee type of the reference type\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303373/tools/clang/lib/Sema/SemaOverload.cpp"
, 4200, __PRETTY_FUNCTION__))
4200 "T1 must be the pointee type of the reference type")((!OrigT1->isReferenceType() && "T1 must be the pointee type of the reference type"
) ? static_cast<void> (0) : __assert_fail ("!OrigT1->isReferenceType() && \"T1 must be the pointee type of the reference type\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303373/tools/clang/lib/Sema/SemaOverload.cpp"
, 4200, __PRETTY_FUNCTION__))
;
4201 assert(!OrigT2->isReferenceType() && "T2 cannot be a reference type")((!OrigT2->isReferenceType() && "T2 cannot be a reference type"
) ? static_cast<void> (0) : __assert_fail ("!OrigT2->isReferenceType() && \"T2 cannot be a reference type\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303373/tools/clang/lib/Sema/SemaOverload.cpp"
, 4201, __PRETTY_FUNCTION__))
;
4202
4203 QualType T1 = Context.getCanonicalType(OrigT1);
4204 QualType T2 = Context.getCanonicalType(OrigT2);
4205 Qualifiers T1Quals, T2Quals;
4206 QualType UnqualT1 = Context.getUnqualifiedArrayType(T1, T1Quals);
4207 QualType UnqualT2 = Context.getUnqualifiedArrayType(T2, T2Quals);
4208
4209 // C++ [dcl.init.ref]p4:
4210 // Given types "cv1 T1" and "cv2 T2," "cv1 T1" is
4211 // reference-related to "cv2 T2" if T1 is the same type as T2, or
4212 // T1 is a base class of T2.
4213 DerivedToBase = false;
4214 ObjCConversion = false;
4215 ObjCLifetimeConversion = false;
4216 QualType ConvertedT2;
4217 if (UnqualT1 == UnqualT2) {
4218 // Nothing to do.
4219 } else if (isCompleteType(Loc, OrigT2) &&
4220 isTypeValid(UnqualT1) && isTypeValid(UnqualT2) &&
4221 IsDerivedFrom(Loc, UnqualT2, UnqualT1))
4222 DerivedToBase = true;
4223 else if (UnqualT1->isObjCObjectOrInterfaceType() &&
4224 UnqualT2->isObjCObjectOrInterfaceType() &&
4225 Context.canBindObjCObjectType(UnqualT1, UnqualT2))
4226 ObjCConversion = true;
4227 else if (UnqualT2->isFunctionType() &&
4228 IsFunctionConversion(UnqualT2, UnqualT1, ConvertedT2))
4229 // C++1z [dcl.init.ref]p4:
4230 // cv1 T1" is reference-compatible with "cv2 T2" if [...] T2 is "noexcept
4231 // function" and T1 is "function"
4232 //
4233 // We extend this to also apply to 'noreturn', so allow any function
4234 // conversion between function types.
4235 return Ref_Compatible;
4236 else
4237 return Ref_Incompatible;
4238
4239 // At this point, we know that T1 and T2 are reference-related (at
4240 // least).
4241
4242 // If the type is an array type, promote the element qualifiers to the type
4243 // for comparison.
4244 if (isa<ArrayType>(T1) && T1Quals)
4245 T1 = Context.getQualifiedType(UnqualT1, T1Quals);
4246 if (isa<ArrayType>(T2) && T2Quals)
4247 T2 = Context.getQualifiedType(UnqualT2, T2Quals);
4248
4249 // C++ [dcl.init.ref]p4:
4250 // "cv1 T1" is reference-compatible with "cv2 T2" if T1 is
4251 // reference-related to T2 and cv1 is the same cv-qualification
4252 // as, or greater cv-qualification than, cv2. For purposes of
4253 // overload resolution, cases for which cv1 is greater
4254 // cv-qualification than cv2 are identified as
4255 // reference-compatible with added qualification (see 13.3.3.2).
4256 //
4257 // Note that we also require equivalence of Objective-C GC and address-space
4258 // qualifiers when performing these computations, so that e.g., an int in
4259 // address space 1 is not reference-compatible with an int in address
4260 // space 2.
4261 if (T1Quals.getObjCLifetime() != T2Quals.getObjCLifetime() &&
4262 T1Quals.compatiblyIncludesObjCLifetime(T2Quals)) {
4263 if (isNonTrivialObjCLifetimeConversion(T2Quals, T1Quals))
4264 ObjCLifetimeConversion = true;
4265
4266 T1Quals.removeObjCLifetime();
4267 T2Quals.removeObjCLifetime();
4268 }
4269
4270 // MS compiler ignores __unaligned qualifier for references; do the same.
4271 T1Quals.removeUnaligned();
4272 T2Quals.removeUnaligned();
4273
4274 if (T1Quals.compatiblyIncludes(T2Quals))
4275 return Ref_Compatible;
4276 else
4277 return Ref_Related;
4278}
4279
4280/// \brief Look for a user-defined conversion to a value reference-compatible
4281/// with DeclType. Return true if something definite is found.
4282static bool
4283FindConversionForRefInit(Sema &S, ImplicitConversionSequence &ICS,
4284 QualType DeclType, SourceLocation DeclLoc,
4285 Expr *Init, QualType T2, bool AllowRvalues,
4286 bool AllowExplicit) {
4287 assert(T2->isRecordType() && "Can only find conversions of record types.")((T2->isRecordType() && "Can only find conversions of record types."
) ? static_cast<void> (0) : __assert_fail ("T2->isRecordType() && \"Can only find conversions of record types.\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303373/tools/clang/lib/Sema/SemaOverload.cpp"
, 4287, __PRETTY_FUNCTION__))
;
4288 CXXRecordDecl *T2RecordDecl
4289 = dyn_cast<CXXRecordDecl>(T2->getAs<RecordType>()->getDecl());
4290
4291 OverloadCandidateSet CandidateSet(DeclLoc, OverloadCandidateSet::CSK_Normal);
4292 const auto &Conversions = T2RecordDecl->getVisibleConversionFunctions();
4293 for (auto I = Conversions.begin(), E = Conversions.end(); I != E; ++I) {
4294 NamedDecl *D = *I;
4295 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(D->getDeclContext());
4296 if (isa<UsingShadowDecl>(D))
4297 D = cast<UsingShadowDecl>(D)->getTargetDecl();
4298
4299 FunctionTemplateDecl *ConvTemplate
4300 = dyn_cast<FunctionTemplateDecl>(D);
4301 CXXConversionDecl *Conv;
4302 if (ConvTemplate)
4303 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl());
4304 else
4305 Conv = cast<CXXConversionDecl>(D);
4306
4307 // If this is an explicit conversion, and we're not allowed to consider
4308 // explicit conversions, skip it.
4309 if (!AllowExplicit && Conv->isExplicit())
4310 continue;
4311
4312 if (AllowRvalues) {
4313 bool DerivedToBase = false;
4314 bool ObjCConversion = false;
4315 bool ObjCLifetimeConversion = false;
4316
4317 // If we are initializing an rvalue reference, don't permit conversion
4318 // functions that return lvalues.
4319 if (!ConvTemplate && DeclType->isRValueReferenceType()) {
4320 const ReferenceType *RefType
4321 = Conv->getConversionType()->getAs<LValueReferenceType>();
4322 if (RefType && !RefType->getPointeeType()->isFunctionType())
4323 continue;
4324 }
4325
4326 if (!ConvTemplate &&
4327 S.CompareReferenceRelationship(
4328 DeclLoc,
4329 Conv->getConversionType().getNonReferenceType()
4330 .getUnqualifiedType(),
4331 DeclType.getNonReferenceType().getUnqualifiedType(),
4332 DerivedToBase, ObjCConversion, ObjCLifetimeConversion) ==
4333 Sema::Ref_Incompatible)
4334 continue;
4335 } else {
4336 // If the conversion function doesn't return a reference type,
4337 // it can't be considered for this conversion. An rvalue reference
4338 // is only acceptable if its referencee is a function type.
4339
4340 const ReferenceType *RefType =
4341 Conv->getConversionType()->getAs<ReferenceType>();
4342 if (!RefType ||
4343 (!RefType->isLValueReferenceType() &&
4344 !RefType->getPointeeType()->isFunctionType()))
4345 continue;
4346 }
4347
4348 if (ConvTemplate)
4349 S.AddTemplateConversionCandidate(ConvTemplate, I.getPair(), ActingDC,
4350 Init, DeclType, CandidateSet,
4351 /*AllowObjCConversionOnExplicit=*/false);
4352 else
4353 S.AddConversionCandidate(Conv, I.getPair(), ActingDC, Init,
4354 DeclType, CandidateSet,
4355 /*AllowObjCConversionOnExplicit=*/false);
4356 }
4357
4358 bool HadMultipleCandidates = (CandidateSet.size() > 1);
4359
4360 OverloadCandidateSet::iterator Best;
4361 switch (CandidateSet.BestViableFunction(S, DeclLoc, Best, true)) {
4362 case OR_Success:
4363 // C++ [over.ics.ref]p1:
4364 //
4365 // [...] If the parameter binds directly to the result of
4366 // applying a conversion function to the argument
4367 // expression, the implicit conversion sequence is a
4368 // user-defined conversion sequence (13.3.3.1.2), with the
4369 // second standard conversion sequence either an identity
4370 // conversion or, if the conversion function returns an
4371 // entity of a type that is a derived class of the parameter
4372 // type, a derived-to-base Conversion.
4373 if (!Best->FinalConversion.DirectBinding)
4374 return false;
4375
4376 ICS.setUserDefined();
4377 ICS.UserDefined.Before = Best->Conversions[0].Standard;
4378 ICS.UserDefined.After = Best->FinalConversion;
4379 ICS.UserDefined.HadMultipleCandidates = HadMultipleCandidates;
4380 ICS.UserDefined.ConversionFunction = Best->Function;
4381 ICS.UserDefined.FoundConversionFunction = Best->FoundDecl;
4382 ICS.UserDefined.EllipsisConversion = false;
4383 assert(ICS.UserDefined.After.ReferenceBinding &&((ICS.UserDefined.After.ReferenceBinding && ICS.UserDefined
.After.DirectBinding && "Expected a direct reference binding!"
) ? static_cast<void> (0) : __assert_fail ("ICS.UserDefined.After.ReferenceBinding && ICS.UserDefined.After.DirectBinding && \"Expected a direct reference binding!\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303373/tools/clang/lib/Sema/SemaOverload.cpp"
, 4385, __PRETTY_FUNCTION__))
4384 ICS.UserDefined.After.DirectBinding &&((ICS.UserDefined.After.ReferenceBinding && ICS.UserDefined
.After.DirectBinding && "Expected a direct reference binding!"
) ? static_cast<void> (0) : __assert_fail ("ICS.UserDefined.After.ReferenceBinding && ICS.UserDefined.After.DirectBinding && \"Expected a direct reference binding!\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303373/tools/clang/lib/Sema/SemaOverload.cpp"
, 4385, __PRETTY_FUNCTION__))
4385 "Expected a direct reference binding!")((ICS.UserDefined.After.ReferenceBinding && ICS.UserDefined
.After.DirectBinding && "Expected a direct reference binding!"
) ? static_cast<void> (0) : __assert_fail ("ICS.UserDefined.After.ReferenceBinding && ICS.UserDefined.After.DirectBinding && \"Expected a direct reference binding!\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303373/tools/clang/lib/Sema/SemaOverload.cpp"
, 4385, __PRETTY_FUNCTION__))
;
4386 return true;
4387
4388 case OR_Ambiguous:
4389 ICS.setAmbiguous();
4390 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin();
4391 Cand != CandidateSet.end(); ++Cand)
4392 if (Cand->Viable)
4393 ICS.Ambiguous.addConversion(Cand->FoundDecl, Cand->Function);
4394 return true;
4395
4396 case OR_No_Viable_Function:
4397 case OR_Deleted:
4398 // There was no suitable conversion, or we found a deleted
4399 // conversion; continue with other checks.
4400 return false;
4401 }
4402
4403 llvm_unreachable("Invalid OverloadResult!")::llvm::llvm_unreachable_internal("Invalid OverloadResult!", "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303373/tools/clang/lib/Sema/SemaOverload.cpp"
, 4403)
;
4404}
4405
4406/// \brief Compute an implicit conversion sequence for reference
4407/// initialization.
4408static ImplicitConversionSequence
4409TryReferenceInit(Sema &S, Expr *Init, QualType DeclType,
4410 SourceLocation DeclLoc,
4411 bool SuppressUserConversions,
4412 bool AllowExplicit) {
4413 assert(DeclType->isReferenceType() && "Reference init needs a reference")((DeclType->isReferenceType() && "Reference init needs a reference"
) ? static_cast<void> (0) : __assert_fail ("DeclType->isReferenceType() && \"Reference init needs a reference\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303373/tools/clang/lib/Sema/SemaOverload.cpp"
, 4413, __PRETTY_FUNCTION__))
;
4414
4415 // Most paths end in a failed conversion.
4416 ImplicitConversionSequence ICS;
4417 ICS.setBad(BadConversionSequence::no_conversion, Init, DeclType);
4418
4419 QualType T1 = DeclType->getAs<ReferenceType>()->getPointeeType();
4420 QualType T2 = Init->getType();
4421
4422 // If the initializer is the address of an overloaded function, try
4423 // to resolve the overloaded function. If all goes well, T2 is the
4424 // type of the resulting function.
4425 if (S.Context.getCanonicalType(T2) == S.Context.OverloadTy) {
4426 DeclAccessPair Found;
4427 if (FunctionDecl *Fn = S.ResolveAddressOfOverloadedFunction(Init, DeclType,
4428 false, Found))
4429 T2 = Fn->getType();
4430 }
4431
4432 // Compute some basic properties of the types and the initializer.
4433 bool isRValRef = DeclType->isRValueReferenceType();
4434 bool DerivedToBase = false;
4435 bool ObjCConversion = false;
4436 bool ObjCLifetimeConversion = false;
4437 Expr::Classification InitCategory = Init->Classify(S.Context);
4438 Sema::ReferenceCompareResult RefRelationship
4439 = S.CompareReferenceRelationship(DeclLoc, T1, T2, DerivedToBase,
4440 ObjCConversion, ObjCLifetimeConversion);
4441
4442
4443 // C++0x [dcl.init.ref]p5:
4444 // A reference to type "cv1 T1" is initialized by an expression
4445 // of type "cv2 T2" as follows:
4446
4447 // -- If reference is an lvalue reference and the initializer expression
4448 if (!isRValRef) {
4449 // -- is an lvalue (but is not a bit-field), and "cv1 T1" is
4450 // reference-compatible with "cv2 T2," or
4451 //
4452 // Per C++ [over.ics.ref]p4, we don't check the bit-field property here.
4453 if (InitCategory.isLValue() && RefRelationship == Sema::Ref_Compatible) {
4454 // C++ [over.ics.ref]p1:
4455 // When a parameter of reference type binds directly (8.5.3)
4456 // to an argument expression, the implicit conversion sequence
4457 // is the identity conversion, unless the argument expression
4458 // has a type that is a derived class of the parameter type,
4459 // in which case the implicit conversion sequence is a
4460 // derived-to-base Conversion (13.3.3.1).
4461 ICS.setStandard();
4462 ICS.Standard.First = ICK_Identity;
4463 ICS.Standard.Second = DerivedToBase? ICK_Derived_To_Base
4464 : ObjCConversion? ICK_Compatible_Conversion
4465 : ICK_Identity;
4466 ICS.Standard.Third = ICK_Identity;
4467 ICS.Standard.FromTypePtr = T2.getAsOpaquePtr();
4468 ICS.Standard.setToType(0, T2);
4469 ICS.Standard.setToType(1, T1);
4470 ICS.Standard.setToType(2, T1);
4471 ICS.Standard.ReferenceBinding = true;
4472 ICS.Standard.DirectBinding = true;
4473 ICS.Standard.IsLvalueReference = !isRValRef;
4474 ICS.Standard.BindsToFunctionLvalue = T2->isFunctionType();
4475 ICS.Standard.BindsToRvalue = false;
4476 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier = false;
4477 ICS.Standard.ObjCLifetimeConversionBinding = ObjCLifetimeConversion;
4478 ICS.Standard.CopyConstructor = nullptr;
4479 ICS.Standard.DeprecatedStringLiteralToCharPtr = false;
4480
4481 // Nothing more to do: the inaccessibility/ambiguity check for
4482 // derived-to-base conversions is suppressed when we're
4483 // computing the implicit conversion sequence (C++
4484 // [over.best.ics]p2).
4485 return ICS;
4486 }
4487
4488 // -- has a class type (i.e., T2 is a class type), where T1 is
4489 // not reference-related to T2, and can be implicitly
4490 // converted to an lvalue of type "cv3 T3," where "cv1 T1"
4491 // is reference-compatible with "cv3 T3" 92) (this
4492 // conversion is selected by enumerating the applicable
4493 // conversion functions (13.3.1.6) and choosing the best
4494 // one through overload resolution (13.3)),
4495 if (!SuppressUserConversions && T2->isRecordType() &&
4496 S.isCompleteType(DeclLoc, T2) &&
4497 RefRelationship == Sema::Ref_Incompatible) {
4498 if (FindConversionForRefInit(S, ICS, DeclType, DeclLoc,
4499 Init, T2, /*AllowRvalues=*/false,
4500 AllowExplicit))
4501 return ICS;
4502 }
4503 }
4504
4505 // -- Otherwise, the reference shall be an lvalue reference to a
4506 // non-volatile const type (i.e., cv1 shall be const), or the reference
4507 // shall be an rvalue reference.
4508 if (!isRValRef && (!T1.isConstQualified() || T1.isVolatileQualified()))
4509 return ICS;
4510
4511 // -- If the initializer expression
4512 //
4513 // -- is an xvalue, class prvalue, array prvalue or function
4514 // lvalue and "cv1 T1" is reference-compatible with "cv2 T2", or
4515 if (RefRelationship == Sema::Ref_Compatible &&
4516 (InitCategory.isXValue() ||
4517 (InitCategory.isPRValue() && (T2->isRecordType() || T2->isArrayType())) ||
4518 (InitCategory.isLValue() && T2->isFunctionType()))) {
4519 ICS.setStandard();
4520 ICS.Standard.First = ICK_Identity;
4521 ICS.Standard.Second = DerivedToBase? ICK_Derived_To_Base
4522 : ObjCConversion? ICK_Compatible_Conversion
4523 : ICK_Identity;
4524 ICS.Standard.Third = ICK_Identity;
4525 ICS.Standard.FromTypePtr = T2.getAsOpaquePtr();
4526 ICS.Standard.setToType(0, T2);
4527 ICS.Standard.setToType(1, T1);
4528 ICS.Standard.setToType(2, T1);
4529 ICS.Standard.ReferenceBinding = true;
4530 // In C++0x, this is always a direct binding. In C++98/03, it's a direct
4531 // binding unless we're binding to a class prvalue.
4532 // Note: Although xvalues wouldn't normally show up in C++98/03 code, we
4533 // allow the use of rvalue references in C++98/03 for the benefit of
4534 // standard library implementors; therefore, we need the xvalue check here.
4535 ICS.Standard.DirectBinding =
4536 S.getLangOpts().CPlusPlus11 ||
4537 !(InitCategory.isPRValue() || T2->isRecordType());
4538 ICS.Standard.IsLvalueReference = !isRValRef;
4539 ICS.Standard.BindsToFunctionLvalue = T2->isFunctionType();
4540 ICS.Standard.BindsToRvalue = InitCategory.isRValue();
4541 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier = false;
4542 ICS.Standard.ObjCLifetimeConversionBinding = ObjCLifetimeConversion;
4543 ICS.Standard.CopyConstructor = nullptr;
4544 ICS.Standard.DeprecatedStringLiteralToCharPtr = false;
4545 return ICS;
4546 }
4547
4548 // -- has a class type (i.e., T2 is a class type), where T1 is not
4549 // reference-related to T2, and can be implicitly converted to
4550 // an xvalue, class prvalue, or function lvalue of type
4551 // "cv3 T3", where "cv1 T1" is reference-compatible with
4552 // "cv3 T3",
4553 //
4554 // then the reference is bound to the value of the initializer
4555 // expression in the first case and to the result of the conversion
4556 // in the second case (or, in either case, to an appropriate base
4557 // class subobject).
4558 if (!SuppressUserConversions && RefRelationship == Sema::Ref_Incompatible &&
4559 T2->isRecordType() && S.isCompleteType(DeclLoc, T2) &&
4560 FindConversionForRefInit(S, ICS, DeclType, DeclLoc,
4561 Init, T2, /*AllowRvalues=*/true,
4562 AllowExplicit)) {
4563 // In the second case, if the reference is an rvalue reference
4564 // and the second standard conversion sequence of the
4565 // user-defined conversion sequence includes an lvalue-to-rvalue
4566 // conversion, the program is ill-formed.
4567 if (ICS.isUserDefined() && isRValRef &&
4568 ICS.UserDefined.After.First == ICK_Lvalue_To_Rvalue)
4569 ICS.setBad(BadConversionSequence::no_conversion, Init, DeclType);
4570
4571 return ICS;
4572 }
4573
4574 // A temporary of function type cannot be created; don't even try.
4575 if (T1->isFunctionType())
4576 return ICS;
4577
4578 // -- Otherwise, a temporary of type "cv1 T1" is created and
4579 // initialized from the initializer expression using the
4580 // rules for a non-reference copy initialization (8.5). The
4581 // reference is then bound to the temporary. If T1 is
4582 // reference-related to T2, cv1 must be the same
4583 // cv-qualification as, or greater cv-qualification than,
4584 // cv2; otherwise, the program is ill-formed.
4585 if (RefRelationship == Sema::Ref_Related) {
4586 // If cv1 == cv2 or cv1 is a greater cv-qualified than cv2, then
4587 // we would be reference-compatible or reference-compatible with
4588 // added qualification. But that wasn't the case, so the reference
4589 // initialization fails.
4590 //
4591 // Note that we only want to check address spaces and cvr-qualifiers here.
4592 // ObjC GC, lifetime and unaligned qualifiers aren't important.
4593 Qualifiers T1Quals = T1.getQualifiers();
4594 Qualifiers T2Quals = T2.getQualifiers();
4595 T1Quals.removeObjCGCAttr();
4596 T1Quals.removeObjCLifetime();
4597 T2Quals.removeObjCGCAttr();
4598 T2Quals.removeObjCLifetime();
4599 // MS compiler ignores __unaligned qualifier for references; do the same.
4600 T1Quals.removeUnaligned();
4601 T2Quals.removeUnaligned();
4602 if (!T1Quals.compatiblyIncludes(T2Quals))
4603 return ICS;
4604 }
4605
4606 // If at least one of the types is a class type, the types are not
4607 // related, and we aren't allowed any user conversions, the
4608 // reference binding fails. This case is important for breaking
4609 // recursion, since TryImplicitConversion below will attempt to
4610 // create a temporary through the use of a copy constructor.
4611 if (SuppressUserConversions && RefRelationship == Sema::Ref_Incompatible &&
4612 (T1->isRecordType() || T2->isRecordType()))
4613 return ICS;
4614
4615 // If T1 is reference-related to T2 and the reference is an rvalue
4616 // reference, the initializer expression shall not be an lvalue.
4617 if (RefRelationship >= Sema::Ref_Related &&
4618 isRValRef && Init->Classify(S.Context).isLValue())
4619 return ICS;
4620
4621 // C++ [over.ics.ref]p2:
4622 // When a parameter of reference type is not bound directly to
4623 // an argument expression, the conversion sequence is the one
4624 // required to convert the argument expression to the
4625 // underlying type of the reference according to
4626 // 13.3.3.1. Conceptually, this conversion sequence corresponds
4627 // to copy-initializing a temporary of the underlying type with
4628 // the argument expression. Any difference in top-level
4629 // cv-qualification is subsumed by the initialization itself
4630 // and does not constitute a conversion.
4631 ICS = TryImplicitConversion(S, Init, T1, SuppressUserConversions,
4632 /*AllowExplicit=*/false,
4633 /*InOverloadResolution=*/false,
4634 /*CStyle=*/false,
4635 /*AllowObjCWritebackConversion=*/false,
4636 /*AllowObjCConversionOnExplicit=*/false);
4637
4638 // Of course, that's still a reference binding.
4639 if (ICS.isStandard()) {
4640 ICS.Standard.ReferenceBinding = true;
4641 ICS.Standard.IsLvalueReference = !isRValRef;
4642 ICS.Standard.BindsToFunctionLvalue = false;
4643 ICS.Standard.BindsToRvalue = true;
4644 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier = false;
4645 ICS.Standard.ObjCLifetimeConversionBinding = false;
4646 } else if (ICS.isUserDefined()) {
4647 const ReferenceType *LValRefType =
4648 ICS.UserDefined.ConversionFunction->getReturnType()
4649 ->getAs<LValueReferenceType>();
4650
4651 // C++ [over.ics.ref]p3:
4652 // Except for an implicit object parameter, for which see 13.3.1, a
4653 // standard conversion sequence cannot be formed if it requires [...]
4654 // binding an rvalue reference to an lvalue other than a function
4655 // lvalue.
4656 // Note that the function case is not possible here.
4657 if (DeclType->isRValueReferenceType() && LValRefType) {
4658 // FIXME: This is the wrong BadConversionSequence. The problem is binding
4659 // an rvalue reference to a (non-function) lvalue, not binding an lvalue
4660 // reference to an rvalue!
4661 ICS.setBad(BadConversionSequence::lvalue_ref_to_rvalue, Init, DeclType);
4662 return ICS;
4663 }
4664
4665 ICS.UserDefined.After.ReferenceBinding = true;
4666 ICS.UserDefined.After.IsLvalueReference = !isRValRef;
4667 ICS.UserDefined.After.BindsToFunctionLvalue = false;
4668 ICS.UserDefined.After.BindsToRvalue = !LValRefType;
4669 ICS.UserDefined.After.BindsImplicitObjectArgumentWithoutRefQualifier = false;
4670 ICS.UserDefined.After.ObjCLifetimeConversionBinding = false;
4671 }
4672
4673 return ICS;
4674}
4675
4676static ImplicitConversionSequence
4677TryCopyInitialization(Sema &S, Expr *From, QualType ToType,
4678 bool SuppressUserConversions,
4679 bool InOverloadResolution,
4680 bool AllowObjCWritebackConversion,
4681 bool AllowExplicit = false);
4682
4683/// TryListConversion - Try to copy-initialize a value of type ToType from the
4684/// initializer list From.
4685static ImplicitConversionSequence
4686TryListConversion(Sema &S, InitListExpr *From, QualType ToType,
4687 bool SuppressUserConversions,
4688 bool InOverloadResolution,
4689 bool AllowObjCWritebackConversion) {
4690 // C++11 [over.ics.list]p1:
4691 // When an argument is an initializer list, it is not an expression and
4692 // special rules apply for converting it to a parameter type.
4693
4694 ImplicitConversionSequence Result;
4695 Result.setBad(BadConversionSequence::no_conversion, From, ToType);
4696
4697 // We need a complete type for what follows. Incomplete types can never be
4698 // initialized from init lists.
4699 if (!S.isCompleteType(From->getLocStart(), ToType))
4700 return Result;
4701
4702 // Per DR1467:
4703 // If the parameter type is a class X and the initializer list has a single
4704 // element of type cv U, where U is X or a class derived from X, the
4705 // implicit conversion sequence is the one required to convert the element
4706 // to the parameter type.
4707 //
4708 // Otherwise, if the parameter type is a character array [... ]
4709 // and the initializer list has a single element that is an
4710 // appropriately-typed string literal (8.5.2 [dcl.init.string]), the
4711 // implicit conversion sequence is the identity conversion.
4712 if (From->getNumInits() == 1) {
4713 if (ToType->isRecordType()) {
4714 QualType InitType = From->getInit(0)->getType();
4715 if (S.Context.hasSameUnqualifiedType(InitType, ToType) ||
4716 S.IsDerivedFrom(From->getLocStart(), InitType, ToType))
4717 return TryCopyInitialization(S, From->getInit(0), ToType,
4718 SuppressUserConversions,
4719 InOverloadResolution,
4720 AllowObjCWritebackConversion);
4721 }
4722 // FIXME: Check the other conditions here: array of character type,
4723 // initializer is a string literal.
4724 if (ToType->isArrayType()) {
4725 InitializedEntity Entity =
4726 InitializedEntity::InitializeParameter(S.Context, ToType,
4727 /*Consumed=*/false);
4728 if (S.CanPerformCopyInitialization(Entity, From)) {
4729 Result.setStandard();
4730 Result.Standard.setAsIdentityConversion();
4731 Result.Standard.setFromType(ToType);
4732 Result.Standard.setAllToTypes(ToType);
4733 return Result;
4734 }
4735 }
4736 }
4737
4738 // C++14 [over.ics.list]p2: Otherwise, if the parameter type [...] (below).
4739 // C++11 [over.ics.list]p2:
4740 // If the parameter type is std::initializer_list<X> or "array of X" and
4741 // all the elements can be implicitly converted to X, the implicit
4742 // conversion sequence is the worst conversion necessary to convert an
4743 // element of the list to X.
4744 //
4745 // C++14 [over.ics.list]p3:
4746 // Otherwise, if the parameter type is "array of N X", if the initializer
4747 // list has exactly N elements or if it has fewer than N elements and X is
4748 // default-constructible, and if all the elements of the initializer list
4749 // can be implicitly converted to X, the implicit conversion sequence is
4750 // the worst conversion necessary to convert an element of the list to X.
4751 //
4752 // FIXME: We're missing a lot of these checks.
4753 bool toStdInitializerList = false;
4754 QualType X;
4755 if (ToType->isArrayType())
4756 X = S.Context.getAsArrayType(ToType)->getElementType();
4757 else
4758 toStdInitializerList = S.isStdInitializerList(ToType, &X);
4759 if (!X.isNull()) {
4760 for (unsigned i = 0, e = From->getNumInits(); i < e; ++i) {
4761 Expr *Init = From->getInit(i);
4762 ImplicitConversionSequence ICS =
4763 TryCopyInitialization(S, Init, X, SuppressUserConversions,
4764 InOverloadResolution,
4765 AllowObjCWritebackConversion);
4766 // If a single element isn't convertible, fail.
4767 if (ICS.isBad()) {
4768 Result = ICS;
4769 break;
4770 }
4771 // Otherwise, look for the worst conversion.
4772 if (Result.isBad() ||
4773 CompareImplicitConversionSequences(S, From->getLocStart(), ICS,
4774 Result) ==
4775 ImplicitConversionSequence::Worse)
4776 Result = ICS;
4777 }
4778
4779 // For an empty list, we won't have computed any conversion sequence.
4780 // Introduce the identity conversion sequence.
4781 if (From->getNumInits() == 0) {
4782 Result.setStandard();
4783 Result.Standard.setAsIdentityConversion();
4784 Result.Standard.setFromType(ToType);
4785 Result.Standard.setAllToTypes(ToType);
4786 }
4787
4788 Result.setStdInitializerListElement(toStdInitializerList);
4789 return Result;
4790 }
4791
4792 // C++14 [over.ics.list]p4:
4793 // C++11 [over.ics.list]p3:
4794 // Otherwise, if the parameter is a non-aggregate class X and overload
4795 // resolution chooses a single best constructor [...] the implicit
4796 // conversion sequence is a user-defined conversion sequence. If multiple
4797 // constructors are viable but none is better than the others, the
4798 // implicit conversion sequence is a user-defined conversion sequence.
4799 if (ToType->isRecordType() && !ToType->isAggregateType()) {
4800 // This function can deal with initializer lists.
4801 return TryUserDefinedConversion(S, From, ToType, SuppressUserConversions,
4802 /*AllowExplicit=*/false,
4803 InOverloadResolution, /*CStyle=*/false,
4804 AllowObjCWritebackConversion,
4805 /*AllowObjCConversionOnExplicit=*/false);
4806 }
4807
4808 // C++14 [over.ics.list]p5:
4809 // C++11 [over.ics.list]p4:
4810 // Otherwise, if the parameter has an aggregate type which can be
4811 // initialized from the initializer list [...] the implicit conversion
4812 // sequence is a user-defined conversion sequence.
4813 if (ToType->isAggregateType()) {
4814 // Type is an aggregate, argument is an init list. At this point it comes
4815 // down to checking whether the initialization works.
4816 // FIXME: Find out whether this parameter is consumed or not.
4817 // FIXME: Expose SemaInit's aggregate initialization code so that we don't
4818 // need to call into the initialization code here; overload resolution
4819 // should not be doing that.
4820 InitializedEntity Entity =
4821 InitializedEntity::InitializeParameter(S.Context, ToType,
4822 /*Consumed=*/false);
4823 if (S.CanPerformCopyInitialization(Entity, From)) {
4824 Result.setUserDefined();
4825 Result.UserDefined.Before.setAsIdentityConversion();
4826 // Initializer lists don't have a type.
4827 Result.UserDefined.Before.setFromType(QualType());
4828 Result.UserDefined.Before.setAllToTypes(QualType());
4829
4830 Result.UserDefined.After.setAsIdentityConversion();
4831 Result.UserDefined.After.setFromType(ToType);
4832 Result.UserDefined.After.setAllToTypes(ToType);
4833 Result.UserDefined.ConversionFunction = nullptr;
4834 }
4835 return Result;
4836 }
4837
4838 // C++14 [over.ics.list]p6:
4839 // C++11 [over.ics.list]p5:
4840 // Otherwise, if the parameter is a reference, see 13.3.3.1.4.
4841 if (ToType->isReferenceType()) {
4842 // The standard is notoriously unclear here, since 13.3.3.1.4 doesn't
4843 // mention initializer lists in any way. So we go by what list-
4844 // initialization would do and try to extrapolate from that.
4845
4846 QualType T1 = ToType->getAs<ReferenceType>()->getPointeeType();
4847
4848 // If the initializer list has a single element that is reference-related
4849 // to the parameter type, we initialize the reference from that.
4850 if (From->getNumInits() == 1) {
4851 Expr *Init = From->getInit(0);
4852
4853 QualType T2 = Init->getType();
4854
4855 // If the initializer is the address of an overloaded function, try
4856 // to resolve the overloaded function. If all goes well, T2 is the
4857 // type of the resulting function.
4858 if (S.Context.getCanonicalType(T2) == S.Context.OverloadTy) {
4859 DeclAccessPair Found;
4860 if (FunctionDecl *Fn = S.ResolveAddressOfOverloadedFunction(
4861 Init, ToType, false, Found))
4862 T2 = Fn->getType();
4863 }
4864
4865 // Compute some basic properties of the types and the initializer.
4866 bool dummy1 = false;
4867 bool dummy2 = false;
4868 bool dummy3 = false;
4869 Sema::ReferenceCompareResult RefRelationship
4870 = S.CompareReferenceRelationship(From->getLocStart(), T1, T2, dummy1,
4871 dummy2, dummy3);
4872
4873 if (RefRelationship >= Sema::Ref_Related) {
4874 return TryReferenceInit(S, Init, ToType, /*FIXME*/From->getLocStart(),
4875 SuppressUserConversions,
4876 /*AllowExplicit=*/false);
4877 }
4878 }
4879
4880 // Otherwise, we bind the reference to a temporary created from the
4881 // initializer list.
4882 Result = TryListConversion(S, From, T1, SuppressUserConversions,
4883 InOverloadResolution,
4884 AllowObjCWritebackConversion);
4885 if (Result.isFailure())
4886 return Result;
4887 assert(!Result.isEllipsis() &&((!Result.isEllipsis() && "Sub-initialization cannot result in ellipsis conversion."
) ? static_cast<void> (0) : __assert_fail ("!Result.isEllipsis() && \"Sub-initialization cannot result in ellipsis conversion.\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303373/tools/clang/lib/Sema/SemaOverload.cpp"
, 4888, __PRETTY_FUNCTION__))
4888 "Sub-initialization cannot result in ellipsis conversion.")((!Result.isEllipsis() && "Sub-initialization cannot result in ellipsis conversion."
) ? static_cast<void> (0) : __assert_fail ("!Result.isEllipsis() && \"Sub-initialization cannot result in ellipsis conversion.\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303373/tools/clang/lib/Sema/SemaOverload.cpp"
, 4888, __PRETTY_FUNCTION__))
;
4889
4890 // Can we even bind to a temporary?
4891 if (ToType->isRValueReferenceType() ||
4892 (T1.isConstQualified() && !T1.isVolatileQualified())) {
4893 StandardConversionSequence &SCS = Result.isStandard() ? Result.Standard :
4894 Result.UserDefined.After;
4895 SCS.ReferenceBinding = true;
4896 SCS.IsLvalueReference = ToType->isLValueReferenceType();
4897 SCS.BindsToRvalue = true;
4898 SCS.BindsToFunctionLvalue = false;
4899 SCS.BindsImplicitObjectArgumentWithoutRefQualifier = false;
4900 SCS.ObjCLifetimeConversionBinding = false;
4901 } else
4902 Result.setBad(BadConversionSequence::lvalue_ref_to_rvalue,
4903 From, ToType);
4904 return Result;
4905 }
4906
4907 // C++14 [over.ics.list]p7:
4908 // C++11 [over.ics.list]p6:
4909 // Otherwise, if the parameter type is not a class:
4910 if (!ToType->isRecordType()) {
4911 // - if the initializer list has one element that is not itself an
4912 // initializer list, the implicit conversion sequence is the one
4913 // required to convert the element to the parameter type.
4914 unsigned NumInits = From->getNumInits();
4915 if (NumInits == 1 && !isa<InitListExpr>(From->getInit(0)))
4916 Result = TryCopyInitialization(S, From->getInit(0), ToType,
4917 SuppressUserConversions,
4918 InOverloadResolution,
4919 AllowObjCWritebackConversion);
4920 // - if the initializer list has no elements, the implicit conversion
4921 // sequence is the identity conversion.
4922 else if (NumInits == 0) {
4923 Result.setStandard();
4924 Result.Standard.setAsIdentityConversion();
4925 Result.Standard.setFromType(ToType);
4926 Result.Standard.setAllToTypes(ToType);
4927 }
4928 return Result;
4929 }
4930
4931 // C++14 [over.ics.list]p8:
4932 // C++11 [over.ics.list]p7:
4933 // In all cases other than those enumerated above, no conversion is possible
4934 return Result;
4935}
4936
4937/// TryCopyInitialization - Try to copy-initialize a value of type
4938/// ToType from the expression From. Return the implicit conversion
4939/// sequence required to pass this argument, which may be a bad
4940/// conversion sequence (meaning that the argument cannot be passed to
4941/// a parameter of this type). If @p SuppressUserConversions, then we
4942/// do not permit any user-defined conversion sequences.
4943static ImplicitConversionSequence
4944TryCopyInitialization(Sema &S, Expr *From, QualType ToType,
4945 bool SuppressUserConversions,
4946 bool InOverloadResolution,
4947 bool AllowObjCWritebackConversion,
4948 bool AllowExplicit) {
4949 if (InitListExpr *FromInitList = dyn_cast<InitListExpr>(From))
4950 return TryListConversion(S, FromInitList, ToType, SuppressUserConversions,
4951 InOverloadResolution,AllowObjCWritebackConversion);
4952
4953 if (ToType->isReferenceType())
4954 return TryReferenceInit(S, From, ToType,
4955 /*FIXME:*/From->getLocStart(),
4956 SuppressUserConversions,
4957 AllowExplicit);
4958
4959 return TryImplicitConversion(S, From, ToType,
4960 SuppressUserConversions,
4961 /*AllowExplicit=*/false,
4962 InOverloadResolution,
4963 /*CStyle=*/false,
4964 AllowObjCWritebackConversion,
4965 /*AllowObjCConversionOnExplicit=*/false);
4966}
4967
4968static bool TryCopyInitialization(const CanQualType FromQTy,
4969 const CanQualType ToQTy,
4970 Sema &S,
4971 SourceLocation Loc,
4972 ExprValueKind FromVK) {
4973 OpaqueValueExpr TmpExpr(Loc, FromQTy, FromVK);
4974 ImplicitConversionSequence ICS =
4975 TryCopyInitialization(S, &TmpExpr, ToQTy, true, true, false);
4976
4977 return !ICS.isBad();
4978}
4979
4980/// TryObjectArgumentInitialization - Try to initialize the object
4981/// parameter of the given member function (@c Method) from the
4982/// expression @p From.
4983static ImplicitConversionSequence
4984TryObjectArgumentInitialization(Sema &S, SourceLocation Loc, QualType FromType,
4985 Expr::Classification FromClassification,
4986 CXXMethodDecl *Method,
4987 CXXRecordDecl *ActingContext) {
4988 QualType ClassType = S.Context.getTypeDeclType(ActingContext);
4989 // [class.dtor]p2: A destructor can be invoked for a const, volatile or
4990 // const volatile object.
4991 unsigned Quals = isa<CXXDestructorDecl>(Method) ?
4992 Qualifiers::Const | Qualifiers::Volatile : Method->getTypeQualifiers();
4993 QualType ImplicitParamType = S.Context.getCVRQualifiedType(ClassType, Quals);
4994
4995 // Set up the conversion sequence as a "bad" conversion, to allow us
4996 // to exit early.
4997 ImplicitConversionSequence ICS;
4998
4999 // We need to have an object of class type.
5000 if (const PointerType *PT = FromType->getAs<PointerType>()) {
5001 FromType = PT->getPointeeType();
5002
5003 // When we had a pointer, it's implicitly dereferenced, so we
5004 // better have an lvalue.
5005 assert(FromClassification.isLValue())((FromClassification.isLValue()) ? static_cast<void> (0
) : __assert_fail ("FromClassification.isLValue()", "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303373/tools/clang/lib/Sema/SemaOverload.cpp"
, 5005, __PRETTY_FUNCTION__))
;
5006 }
5007
5008 assert(FromType->isRecordType())((FromType->isRecordType()) ? static_cast<void> (0) :
__assert_fail ("FromType->isRecordType()", "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303373/tools/clang/lib/Sema/SemaOverload.cpp"
, 5008, __PRETTY_FUNCTION__))
;
5009
5010 // C++0x [over.match.funcs]p4:
5011 // For non-static member functions, the type of the implicit object
5012 // parameter is
5013 //
5014 // - "lvalue reference to cv X" for functions declared without a
5015 // ref-qualifier or with the & ref-qualifier
5016 // - "rvalue reference to cv X" for functions declared with the &&
5017 // ref-qualifier
5018 //
5019 // where X is the class of which the function is a member and cv is the
5020 // cv-qualification on the member function declaration.
5021 //
5022 // However, when finding an implicit conversion sequence for the argument, we
5023 // are not allowed to perform user-defined conversions
5024 // (C++ [over.match.funcs]p5). We perform a simplified version of
5025 // reference binding here, that allows class rvalues to bind to
5026 // non-constant references.
5027
5028 // First check the qualifiers.
5029 QualType FromTypeCanon = S.Context.getCanonicalType(FromType);
5030 if (ImplicitParamType.getCVRQualifiers()
5031 != FromTypeCanon.getLocalCVRQualifiers() &&
5032 !ImplicitParamType.isAtLeastAsQualifiedAs(FromTypeCanon)) {
5033 ICS.setBad(BadConversionSequence::bad_qualifiers,
5034 FromType, ImplicitParamType);
5035 return ICS;
5036 }
5037
5038 // Check that we have either the same type or a derived type. It
5039 // affects the conversion rank.
5040 QualType ClassTypeCanon = S.Context.getCanonicalType(ClassType);
5041 ImplicitConversionKind SecondKind;
5042 if (ClassTypeCanon == FromTypeCanon.getLocalUnqualifiedType()) {
5043 SecondKind = ICK_Identity;
5044 } else if (S.IsDerivedFrom(Loc, FromType, ClassType))
5045 SecondKind = ICK_Derived_To_Base;
5046 else {
5047 ICS.setBad(BadConversionSequence::unrelated_class,
5048 FromType, ImplicitParamType);
5049 return ICS;
5050 }
5051
5052 // Check the ref-qualifier.
5053 switch (Method->getRefQualifier()) {
5054 case RQ_None:
5055 // Do nothing; we don't care about lvalueness or rvalueness.
5056 break;
5057
5058 case RQ_LValue:
5059 if (!FromClassification.isLValue() && Quals != Qualifiers::Const) {
5060 // non-const lvalue reference cannot bind to an rvalue
5061 ICS.setBad(BadConversionSequence::lvalue_ref_to_rvalue, FromType,
5062 ImplicitParamType);
5063 return ICS;
5064 }
5065 break;
5066
5067 case RQ_RValue:
5068 if (!FromClassification.isRValue()) {
5069 // rvalue reference cannot bind to an lvalue
5070 ICS.setBad(BadConversionSequence::rvalue_ref_to_lvalue, FromType,
5071 ImplicitParamType);
5072 return ICS;
5073 }
5074 break;
5075 }
5076
5077 // Success. Mark this as a reference binding.
5078 ICS.setStandard();
5079 ICS.Standard.setAsIdentityConversion();
5080 ICS.Standard.Second = SecondKind;
5081 ICS.Standard.setFromType(FromType);
5082 ICS.Standard.setAllToTypes(ImplicitParamType);
5083 ICS.Standard.ReferenceBinding = true;
5084 ICS.Standard.DirectBinding = true;
5085 ICS.Standard.IsLvalueReference = Method->getRefQualifier() != RQ_RValue;
5086 ICS.Standard.BindsToFunctionLvalue = false;
5087 ICS.Standard.BindsToRvalue = FromClassification.isRValue();
5088 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier
5089 = (Method->getRefQualifier() == RQ_None);
5090 return ICS;
5091}
5092
5093/// PerformObjectArgumentInitialization - Perform initialization of
5094/// the implicit object parameter for the given Method with the given
5095/// expression.
5096ExprResult
5097Sema::PerformObjectArgumentInitialization(Expr *From,
5098 NestedNameSpecifier *Qualifier,
5099 NamedDecl *FoundDecl,
5100 CXXMethodDecl *Method) {
5101 QualType FromRecordType, DestType;
5102 QualType ImplicitParamRecordType =
5103 Method->getThisType(Context)->getAs<PointerType>()->getPointeeType();
5104
5105 Expr::Classification FromClassification;
5106 if (const PointerType *PT = From->getType()->getAs<PointerType>()) {
5107 FromRecordType = PT->getPointeeType();
5108 DestType = Method->getThisType(Context);
5109 FromClassification = Expr::Classification::makeSimpleLValue();
5110 } else {
5111 FromRecordType = From->getType();
5112 DestType = ImplicitParamRecordType;
5113 FromClassification = From->Classify(Context);
5114 }
5115
5116 // Note that we always use the true parent context when performing
5117 // the actual argument initialization.
5118 ImplicitConversionSequence ICS = TryObjectArgumentInitialization(
5119 *this, From->getLocStart(), From->getType(), FromClassification, Method,
5120 Method->getParent());
5121 if (ICS.isBad()) {
5122 if (ICS.Bad.Kind == BadConversionSequence::bad_qualifiers) {
5123 Qualifiers FromQs = FromRecordType.getQualifiers();
5124 Qualifiers ToQs = DestType.getQualifiers();
5125 unsigned CVR = FromQs.getCVRQualifiers() & ~ToQs.getCVRQualifiers();
5126 if (CVR) {
5127 Diag(From->getLocStart(),
5128 diag::err_member_function_call_bad_cvr)
5129 << Method->getDeclName() << FromRecordType << (CVR - 1)
5130 << From->getSourceRange();
5131 Diag(Method->getLocation(), diag::note_previous_decl)
5132 << Method->getDeclName();
5133 return ExprError();
5134 }
5135 }
5136
5137 return Diag(From->getLocStart(),
5138 diag::err_implicit_object_parameter_init)
5139 << ImplicitParamRecordType << FromRecordType << From->getSourceRange();
5140 }
5141
5142 if (ICS.Standard.Second == ICK_Derived_To_Base) {
5143 ExprResult FromRes =
5144 PerformObjectMemberConversion(From, Qualifier, FoundDecl, Method);
5145 if (FromRes.isInvalid())
5146 return ExprError();
5147 From = FromRes.get();
5148 }
5149
5150 if (!Context.hasSameType(From->getType(), DestType))
5151 From = ImpCastExprToType(From, DestType, CK_NoOp,
5152 From->getValueKind()).get();
5153 return From;
5154}
5155
5156/// TryContextuallyConvertToBool - Attempt to contextually convert the
5157/// expression From to bool (C++0x [conv]p3).
5158static ImplicitConversionSequence
5159TryContextuallyConvertToBool(Sema &S, Expr *From) {
5160 return TryImplicitConversion(S, From, S.Context.BoolTy,
5161 /*SuppressUserConversions=*/false,
5162 /*AllowExplicit=*/true,
5163 /*InOverloadResolution=*/false,
5164 /*CStyle=*/false,
5165 /*AllowObjCWritebackConversion=*/false,
5166 /*AllowObjCConversionOnExplicit=*/false);
5167}
5168
5169/// PerformContextuallyConvertToBool - Perform a contextual conversion
5170/// of the expression From to bool (C++0x [conv]p3).
5171ExprResult Sema::PerformContextuallyConvertToBool(Expr *From) {
5172 if (checkPlaceholderForOverload(*this, From))
5173 return ExprError();
5174
5175 ImplicitConversionSequence ICS = TryContextuallyConvertToBool(*this, From);
5176 if (!ICS.isBad())
5177 return PerformImplicitConversion(From, Context.BoolTy, ICS, AA_Converting);
5178
5179 if (!DiagnoseMultipleUserDefinedConversion(From, Context.BoolTy))
5180 return Diag(From->getLocStart(),
5181 diag::err_typecheck_bool_condition)
5182 << From->getType() << From->getSourceRange();
5183 return ExprError();
5184}
5185
5186/// Check that the specified conversion is permitted in a converted constant
5187/// expression, according to C++11 [expr.const]p3. Return true if the conversion
5188/// is acceptable.
5189static bool CheckConvertedConstantConversions(Sema &S,
5190 StandardConversionSequence &SCS) {
5191 // Since we know that the target type is an integral or unscoped enumeration
5192 // type, most conversion kinds are impossible. All possible First and Third
5193 // conversions are fine.
5194 switch (SCS.Second) {
5195 case ICK_Identity:
5196 case ICK_Function_Conversion:
5197 case ICK_Integral_Promotion:
5198 case ICK_Integral_Conversion: // Narrowing conversions are checked elsewhere.
5199 case ICK_Zero_Queue_Conversion:
5200 return true;
5201
5202 case ICK_Boolean_Conversion:
5203 // Conversion from an integral or unscoped enumeration type to bool is
5204 // classified as ICK_Boolean_Conversion, but it's also arguably an integral
5205 // conversion, so we allow it in a converted constant expression.
5206 //
5207 // FIXME: Per core issue 1407, we should not allow this, but that breaks
5208 // a lot of popular code. We should at least add a warning for this
5209 // (non-conforming) extension.
5210 return SCS.getFromType()->isIntegralOrUnscopedEnumerationType() &&
5211 SCS.getToType(2)->isBooleanType();
5212
5213 case ICK_Pointer_Conversion:
5214 case ICK_Pointer_Member:
5215 // C++1z: null pointer conversions and null member pointer conversions are
5216 // only permitted if the source type is std::nullptr_t.
5217 return SCS.getFromType()->isNullPtrType();
5218
5219 case ICK_Floating_Promotion:
5220 case ICK_Complex_Promotion:
5221 case ICK_Floating_Conversion:
5222 case ICK_Complex_Conversion:
5223 case ICK_Floating_Integral:
5224 case ICK_Compatible_Conversion:
5225 case ICK_Derived_To_Base:
5226 case ICK_Vector_Conversion:
5227 case ICK_Vector_Splat:
5228 case ICK_Complex_Real:
5229 case ICK_Block_Pointer_Conversion:
5230 case ICK_TransparentUnionConversion:
5231 case ICK_Writeback_Conversion:
5232 case ICK_Zero_Event_Conversion:
5233 case ICK_C_Only_Conversion:
5234 case ICK_Incompatible_Pointer_Conversion:
5235 return false;
5236
5237 case ICK_Lvalue_To_Rvalue:
5238 case ICK_Array_To_Pointer:
5239 case ICK_Function_To_Pointer:
5240 llvm_unreachable("found a first conversion kind in Second")::llvm::llvm_unreachable_internal("found a first conversion kind in Second"
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303373/tools/clang/lib/Sema/SemaOverload.cpp"
, 5240)
;
5241
5242 case ICK_Qualification:
5243 llvm_unreachable("found a third conversion kind in Second")::llvm::llvm_unreachable_internal("found a third conversion kind in Second"
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303373/tools/clang/lib/Sema/SemaOverload.cpp"
, 5243)
;
5244
5245 case ICK_Num_Conversion_Kinds:
5246 break;
5247 }
5248
5249 llvm_unreachable("unknown conversion kind")::llvm::llvm_unreachable_internal("unknown conversion kind", "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303373/tools/clang/lib/Sema/SemaOverload.cpp"
, 5249)
;
5250}
5251
5252/// CheckConvertedConstantExpression - Check that the expression From is a
5253/// converted constant expression of type T, perform the conversion and produce
5254/// the converted expression, per C++11 [expr.const]p3.
5255static ExprResult CheckConvertedConstantExpression(Sema &S, Expr *From,
5256 QualType T, APValue &Value,
5257 Sema::CCEKind CCE,
5258 bool RequireInt) {
5259 assert(S.getLangOpts().CPlusPlus11 &&((S.getLangOpts().CPlusPlus11 && "converted constant expression outside C++11"
) ? static_cast<void> (0) : __assert_fail ("S.getLangOpts().CPlusPlus11 && \"converted constant expression outside C++11\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303373/tools/clang/lib/Sema/SemaOverload.cpp"
, 5260, __PRETTY_FUNCTION__))
5260 "converted constant expression outside C++11")((S.getLangOpts().CPlusPlus11 && "converted constant expression outside C++11"
) ? static_cast<void> (0) : __assert_fail ("S.getLangOpts().CPlusPlus11 && \"converted constant expression outside C++11\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303373/tools/clang/lib/Sema/SemaOverload.cpp"
, 5260, __PRETTY_FUNCTION__))
;
5261
5262 if (checkPlaceholderForOverload(S, From))
5263 return ExprError();
5264
5265 // C++1z [expr.const]p3:
5266 // A converted constant expression of type T is an expression,
5267 // implicitly converted to type T, where the converted
5268 // expression is a constant expression and the implicit conversion
5269 // sequence contains only [... list of conversions ...].
5270 // C++1z [stmt.if]p2:
5271 // If the if statement is of the form if constexpr, the value of the
5272 // condition shall be a contextually converted constant expression of type
5273 // bool.
5274 ImplicitConversionSequence ICS =
5275 CCE == Sema::CCEK_ConstexprIf
5276 ? TryContextuallyConvertToBool(S, From)
5277 : TryCopyInitialization(S, From, T,
5278 /*SuppressUserConversions=*/false,
5279 /*InOverloadResolution=*/false,
5280 /*AllowObjcWritebackConversion=*/false,
5281 /*AllowExplicit=*/false);
5282 StandardConversionSequence *SCS = nullptr;
5283 switch (ICS.getKind()) {
5284 case ImplicitConversionSequence::StandardConversion:
5285 SCS = &ICS.Standard;
5286 break;
5287 case ImplicitConversionSequence::UserDefinedConversion:
5288 // We are converting to a non-class type, so the Before sequence
5289 // must be trivial.
5290 SCS = &ICS.UserDefined.After;
5291 break;
5292 case ImplicitConversionSequence::AmbiguousConversion:
5293 case ImplicitConversionSequence::BadConversion:
5294 if (!S.DiagnoseMultipleUserDefinedConversion(From, T))
5295 return S.Diag(From->getLocStart(),
5296 diag::err_typecheck_converted_constant_expression)
5297 << From->getType() << From->getSourceRange() << T;
5298 return ExprError();
5299
5300 case ImplicitConversionSequence::EllipsisConversion:
5301 llvm_unreachable("ellipsis conversion in converted constant expression")::llvm::llvm_unreachable_internal("ellipsis conversion in converted constant expression"
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303373/tools/clang/lib/Sema/SemaOverload.cpp"
, 5301)
;
5302 }
5303
5304 // Check that we would only use permitted conversions.
5305 if (!CheckConvertedConstantConversions(S, *SCS)) {
5306 return S.Diag(From->getLocStart(),
5307 diag::err_typecheck_converted_constant_expression_disallowed)
5308 << From->getType() << From->getSourceRange() << T;
5309 }
5310 // [...] and where the reference binding (if any) binds directly.
5311 if (SCS->ReferenceBinding && !SCS->DirectBinding) {
5312 return S.Diag(From->getLocStart(),
5313 diag::err_typecheck_converted_constant_expression_indirect)
5314 << From->getType() << From->getSourceRange() << T;
5315 }
5316
5317 ExprResult Result =
5318 S.PerformImplicitConversion(From, T, ICS, Sema::AA_Converting);
5319 if (Result.isInvalid())
5320 return Result;
5321
5322 // Check for a narrowing implicit conversion.
5323 APValue PreNarrowingValue;
5324 QualType PreNarrowingType;
5325 switch (SCS->getNarrowingKind(S.Context, Result.get(), PreNarrowingValue,
5326 PreNarrowingType)) {
5327 case NK_Dependent_Narrowing:
5328 // Implicit conversion to a narrower type, but the expression is
5329 // value-dependent so we can't tell whether it's actually narrowing.
5330 case NK_Variable_Narrowing:
5331 // Implicit conversion to a narrower type, and the value is not a constant
5332 // expression. We'll diagnose this in a moment.
5333 case NK_Not_Narrowing:
5334 break;
5335
5336 case NK_Constant_Narrowing:
5337 S.Diag(From->getLocStart(), diag::ext_cce_narrowing)
5338 << CCE << /*Constant*/1
5339 << PreNarrowingValue.getAsString(S.Context, PreNarrowingType) << T;
5340 break;
5341
5342 case NK_Type_Narrowing:
5343 S.Diag(From->getLocStart(), diag::ext_cce_narrowing)
5344 << CCE << /*Constant*/0 << From->getType() << T;
5345 break;
5346 }
5347
5348 if (Result.get()->isValueDependent()) {
5349 Value = APValue();
5350 return Result;
5351 }
5352
5353 // Check the expression is a constant expression.
5354 SmallVector<PartialDiagnosticAt, 8> Notes;
5355 Expr::EvalResult Eval;
5356 Eval.Diag = &Notes;
5357
5358 if ((T->isReferenceType()
5359 ? !Result.get()->EvaluateAsLValue(Eval, S.Context)
5360 : !Result.get()->EvaluateAsRValue(Eval, S.Context)) ||
5361 (RequireInt && !Eval.Val.isInt())) {
5362 // The expression can't be folded, so we can't keep it at this position in
5363 // the AST.
5364 Result = ExprError();
5365 } else {
5366 Value = Eval.Val;
5367
5368 if (Notes.empty()) {
5369 // It's a constant expression.
5370 return Result;
5371 }
5372 }
5373
5374 // It's not a constant expression. Produce an appropriate diagnostic.
5375 if (Notes.size() == 1 &&
5376 Notes[0].second.getDiagID() == diag::note_invalid_subexpr_in_const_expr)
5377 S.Diag(Notes[0].first, diag::err_expr_not_cce) << CCE;
5378 else {
5379 S.Diag(From->getLocStart(), diag::err_expr_not_cce)
5380 << CCE << From->getSourceRange();
5381 for (unsigned I = 0; I < Notes.size(); ++I)
5382 S.Diag(Notes[I].first, Notes[I].second);
5383 }
5384 return ExprError();
5385}
5386
5387ExprResult Sema::CheckConvertedConstantExpression(Expr *From, QualType T,
5388 APValue &Value, CCEKind CCE) {
5389 return ::CheckConvertedConstantExpression(*this, From, T, Value, CCE, false);
5390}
5391
5392ExprResult Sema::CheckConvertedConstantExpression(Expr *From, QualType T,
5393 llvm::APSInt &Value,
5394 CCEKind CCE) {
5395 assert(T->isIntegralOrEnumerationType() && "unexpected converted const type")((T->isIntegralOrEnumerationType() && "unexpected converted const type"
) ? static_cast<void> (0) : __assert_fail ("T->isIntegralOrEnumerationType() && \"unexpected converted const type\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303373/tools/clang/lib/Sema/SemaOverload.cpp"
, 5395, __PRETTY_FUNCTION__))
;
5396
5397 APValue V;
5398 auto R = ::CheckConvertedConstantExpression(*this, From, T, V, CCE, true);
5399 if (!R.isInvalid() && !R.get()->isValueDependent())
5400 Value = V.getInt();
5401 return R;
5402}
5403
5404
5405/// dropPointerConversions - If the given standard conversion sequence
5406/// involves any pointer conversions, remove them. This may change
5407/// the result type of the conversion sequence.
5408static void dropPointerConversion(StandardConversionSequence &SCS) {
5409 if (SCS.Second == ICK_Pointer_Conversion) {
5410 SCS.Second = ICK_Identity;
5411 SCS.Third = ICK_Identity;
5412 SCS.ToTypePtrs[2] = SCS.ToTypePtrs[1] = SCS.ToTypePtrs[0];
5413 }
5414}
5415
5416/// TryContextuallyConvertToObjCPointer - Attempt to contextually
5417/// convert the expression From to an Objective-C pointer type.
5418static ImplicitConversionSequence
5419TryContextuallyConvertToObjCPointer(Sema &S, Expr *From) {
5420 // Do an implicit conversion to 'id'.
5421 QualType Ty = S.Context.getObjCIdType();
5422 ImplicitConversionSequence ICS
5423 = TryImplicitConversion(S, From, Ty,
5424 // FIXME: Are these flags correct?
5425 /*SuppressUserConversions=*/false,
5426 /*AllowExplicit=*/true,
5427 /*InOverloadResolution=*/false,
5428 /*CStyle=*/false,
5429 /*AllowObjCWritebackConversion=*/false,
5430 /*AllowObjCConversionOnExplicit=*/true);
5431
5432 // Strip off any final conversions to 'id'.
5433 switch (ICS.getKind()) {
5434 case ImplicitConversionSequence::BadConversion:
5435 case ImplicitConversionSequence::AmbiguousConversion:
5436 case ImplicitConversionSequence::EllipsisConversion:
5437 break;
5438
5439 case ImplicitConversionSequence::UserDefinedConversion:
5440 dropPointerConversion(ICS.UserDefined.After);
5441 break;
5442
5443 case ImplicitConversionSequence::StandardConversion:
5444 dropPointerConversion(ICS.Standard);
5445 break;
5446 }
5447
5448 return ICS;
5449}
5450
5451/// PerformContextuallyConvertToObjCPointer - Perform a contextual
5452/// conversion of the expression From to an Objective-C pointer type.
5453/// Returns a valid but null ExprResult if no conversion sequence exists.
5454ExprResult Sema::PerformContextuallyConvertToObjCPointer(Expr *From) {
5455 if (checkPlaceholderForOverload(*this, From))
5456 return ExprError();
5457
5458 QualType Ty = Context.getObjCIdType();
5459 ImplicitConversionSequence ICS =
5460 TryContextuallyConvertToObjCPointer(*this, From);
5461 if (!ICS.isBad())
5462 return PerformImplicitConversion(From, Ty, ICS, AA_Converting);
5463 return ExprResult();
5464}
5465
5466/// Determine whether the provided type is an integral type, or an enumeration
5467/// type of a permitted flavor.
5468bool Sema::ICEConvertDiagnoser::match(QualType T) {
5469 return AllowScopedEnumerations ? T->isIntegralOrEnumerationType()
5470 : T->isIntegralOrUnscopedEnumerationType();
5471}
5472
5473static ExprResult
5474diagnoseAmbiguousConversion(Sema &SemaRef, SourceLocation Loc, Expr *From,
5475 Sema::ContextualImplicitConverter &Converter,
5476 QualType T, UnresolvedSetImpl &ViableConversions) {
5477
5478 if (Converter.Suppress)
5479 return ExprError();
5480
5481 Converter.diagnoseAmbiguous(SemaRef, Loc, T) << From->getSourceRange();
5482 for (unsigned I = 0, N = ViableConversions.size(); I != N; ++I) {
5483 CXXConversionDecl *Conv =
5484 cast<CXXConversionDecl>(ViableConversions[I]->getUnderlyingDecl());
5485 QualType ConvTy = Conv->getConversionType().getNonReferenceType();
5486 Converter.noteAmbiguous(SemaRef, Conv, ConvTy);
5487 }
5488 return From;
5489}
5490
5491static bool
5492diagnoseNoViableConversion(Sema &SemaRef, SourceLocation Loc, Expr *&From,
5493 Sema::ContextualImplicitConverter &Converter,
5494 QualType T, bool HadMultipleCandidates,
5495 UnresolvedSetImpl &ExplicitConversions) {
5496 if (ExplicitConversions.size() == 1 && !Converter.Suppress) {
5497 DeclAccessPair Found = ExplicitConversions[0];
5498 CXXConversionDecl *Conversion =
5499 cast<CXXConversionDecl>(Found->getUnderlyingDecl());
5500
5501 // The user probably meant to invoke the given explicit
5502 // conversion; use it.
5503 QualType ConvTy = Conversion->getConversionType().getNonReferenceType();
5504 std::string TypeStr;
5505 ConvTy.getAsStringInternal(TypeStr, SemaRef.getPrintingPolicy());
5506
5507 Converter.diagnoseExplicitConv(SemaRef, Loc, T, ConvTy)
5508 << FixItHint::CreateInsertion(From->getLocStart(),
5509 "static_cast<" + TypeStr + ">(")
5510 << FixItHint::CreateInsertion(
5511 SemaRef.getLocForEndOfToken(From->getLocEnd()), ")");
5512 Converter.noteExplicitConv(SemaRef, Conversion, ConvTy);
5513
5514 // If we aren't in a SFINAE context, build a call to the
5515 // explicit conversion function.
5516 if (SemaRef.isSFINAEContext())
5517 return true;
5518
5519 SemaRef.CheckMemberOperatorAccess(From->getExprLoc(), From, nullptr, Found);
5520 ExprResult Result = SemaRef.BuildCXXMemberCallExpr(From, Found, Conversion,
5521 HadMultipleCandidates);
5522 if (Result.isInvalid())
5523 return true;
5524 // Record usage of conversion in an implicit cast.
5525 From = ImplicitCastExpr::Create(SemaRef.Context, Result.get()->getType(),
5526 CK_UserDefinedConversion, Result.get(),
5527 nullptr, Result.get()->getValueKind());
5528 }
5529 return false;
5530}
5531
5532static bool recordConversion(Sema &SemaRef, SourceLocation Loc, Expr *&From,
5533 Sema::ContextualImplicitConverter &Converter,
5534 QualType T, bool HadMultipleCandidates,
5535 DeclAccessPair &Found) {
5536 CXXConversionDecl *Conversion =
5537 cast<CXXConversionDecl>(Found->getUnderlyingDecl());
5538 SemaRef.CheckMemberOperatorAccess(From->getExprLoc(), From, nullptr, Found);
5539
5540 QualType ToType = Conversion->getConversionType().getNonReferenceType();
5541 if (!Converter.SuppressConversion) {
5542 if (SemaRef.isSFINAEContext())
5543 return true;
5544
5545 Converter.diagnoseConversion(SemaRef, Loc, T, ToType)
5546 << From->getSourceRange();
5547 }
5548
5549 ExprResult Result = SemaRef.BuildCXXMemberCallExpr(From, Found, Conversion,
5550 HadMultipleCandidates);
5551 if (Result.isInvalid())
5552 return true;
5553 // Record usage of conversion in an implicit cast.
5554 From = ImplicitCastExpr::Create(SemaRef.Context, Result.get()->getType(),
5555 CK_UserDefinedConversion, Result.get(),
5556 nullptr, Result.get()->getValueKind());
5557 return false;
5558}
5559
5560static ExprResult finishContextualImplicitConversion(
5561 Sema &SemaRef, SourceLocation Loc, Expr *From,
5562 Sema::ContextualImplicitConverter &Converter) {
5563 if (!Converter.match(From->getType()) && !Converter.Suppress)
5564 Converter.diagnoseNoMatch(SemaRef, Loc, From->getType())
5565 << From->getSourceRange();
5566
5567 return SemaRef.DefaultLvalueConversion(From);
5568}
5569
5570static void
5571collectViableConversionCandidates(Sema &SemaRef, Expr *From, QualType ToType,
5572 UnresolvedSetImpl &ViableConversions,
5573 OverloadCandidateSet &CandidateSet) {
5574 for (unsigned I = 0, N = ViableConversions.size(); I != N; ++I) {
5575 DeclAccessPair FoundDecl = ViableConversions[I];
5576 NamedDecl *D = FoundDecl.getDecl();
5577 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext());
5578 if (isa<UsingShadowDecl>(D))
5579 D = cast<UsingShadowDecl>(D)->getTargetDecl();
5580
5581 CXXConversionDecl *Conv;
5582 FunctionTemplateDecl *ConvTemplate;
5583 if ((ConvTemplate = dyn_cast<FunctionTemplateDecl>(D)))
5584 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl());
5585 else
5586 Conv = cast<CXXConversionDecl>(D);
5587
5588 if (ConvTemplate)
5589 SemaRef.AddTemplateConversionCandidate(
5590 ConvTemplate, FoundDecl, ActingContext, From, ToType, CandidateSet,
5591 /*AllowObjCConversionOnExplicit=*/false);
5592 else
5593 SemaRef.AddConversionCandidate(Conv, FoundDecl, ActingContext, From,
5594 ToType, CandidateSet,
5595 /*AllowObjCConversionOnExplicit=*/false);
5596 }
5597}
5598
5599/// \brief Attempt to convert the given expression to a type which is accepted
5600/// by the given converter.
5601///
5602/// This routine will attempt to convert an expression of class type to a
5603/// type accepted by the specified converter. In C++11 and before, the class
5604/// must have a single non-explicit conversion function converting to a matching
5605/// type. In C++1y, there can be multiple such conversion functions, but only
5606/// one target type.
5607///
5608/// \param Loc The source location of the construct that requires the
5609/// conversion.
5610///
5611/// \param From The expression we're converting from.
5612///
5613/// \param Converter Used to control and diagnose the conversion process.
5614///
5615/// \returns The expression, converted to an integral or enumeration type if
5616/// successful.
5617ExprResult Sema::PerformContextualImplicitConversion(
5618 SourceLocation Loc, Expr *From, ContextualImplicitConverter &Converter) {
5619 // We can't perform any more checking for type-dependent expressions.
5620 if (From->isTypeDependent())
5621 return From;
5622
5623 // Process placeholders immediately.
5624 if (From->hasPlaceholderType()) {
5625 ExprResult result = CheckPlaceholderExpr(From);
5626 if (result.isInvalid())
5627 return result;
5628 From = result.get();
5629 }
5630
5631 // If the expression already has a matching type, we're golden.
5632 QualType T = From->getType();
5633 if (Converter.match(T))
5634 return DefaultLvalueConversion(From);
5635
5636 // FIXME: Check for missing '()' if T is a function type?
5637
5638 // We can only perform contextual implicit conversions on objects of class
5639 // type.
5640 const RecordType *RecordTy = T->getAs<RecordType>();
5641 if (!RecordTy || !getLangOpts().CPlusPlus) {
5642 if (!Converter.Suppress)
5643 Converter.diagnoseNoMatch(*this, Loc, T) << From->getSourceRange();
5644 return From;
5645 }
5646
5647 // We must have a complete class type.
5648 struct TypeDiagnoserPartialDiag : TypeDiagnoser {
5649 ContextualImplicitConverter &Converter;
5650 Expr *From;
5651
5652 TypeDiagnoserPartialDiag(ContextualImplicitConverter &Converter, Expr *From)
5653 : Converter(Converter), From(From) {}
5654
5655 void diagnose(Sema &S, SourceLocation Loc, QualType T) override {
5656 Converter.diagnoseIncomplete(S, Loc, T) << From->getSourceRange();
5657 }
5658 } IncompleteDiagnoser(Converter, From);
5659
5660 if (Converter.Suppress ? !isCompleteType(Loc, T)
5661 : RequireCompleteType(Loc, T, IncompleteDiagnoser))
5662 return From;
5663
5664 // Look for a conversion to an integral or enumeration type.
5665 UnresolvedSet<4>
5666 ViableConversions; // These are *potentially* viable in C++1y.
5667 UnresolvedSet<4> ExplicitConversions;
5668 const auto &Conversions =
5669 cast<CXXRecordDecl>(RecordTy->getDecl())->getVisibleConversionFunctions();
5670
5671 bool HadMultipleCandidates =
5672 (std::distance(Conversions.begin(), Conversions.end()) > 1);
5673
5674 // To check that there is only one target type, in C++1y:
5675 QualType ToType;
5676 bool HasUniqueTargetType = true;
5677
5678 // Collect explicit or viable (potentially in C++1y) conversions.
5679 for (auto I = Conversions.begin(), E = Conversions.end(); I != E; ++I) {
5680 NamedDecl *D = (*I)->getUnderlyingDecl();
5681 CXXConversionDecl *Conversion;
5682 FunctionTemplateDecl *ConvTemplate = dyn_cast<FunctionTemplateDecl>(D);
5683 if (ConvTemplate) {
5684 if (getLangOpts().CPlusPlus14)
5685 Conversion = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl());
5686 else
5687 continue; // C++11 does not consider conversion operator templates(?).
5688 } else
5689 Conversion = cast<CXXConversionDecl>(D);
5690
5691 assert((!ConvTemplate || getLangOpts().CPlusPlus14) &&(((!ConvTemplate || getLangOpts().CPlusPlus14) && "Conversion operator templates are considered potentially "
"viable in C++1y") ? static_cast<void> (0) : __assert_fail
("(!ConvTemplate || getLangOpts().CPlusPlus14) && \"Conversion operator templates are considered potentially \" \"viable in C++1y\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303373/tools/clang/lib/Sema/SemaOverload.cpp"
, 5693, __PRETTY_FUNCTION__))
5692 "Conversion operator templates are considered potentially "(((!ConvTemplate || getLangOpts().CPlusPlus14) && "Conversion operator templates are considered potentially "
"viable in C++1y") ? static_cast<void> (0) : __assert_fail
("(!ConvTemplate || getLangOpts().CPlusPlus14) && \"Conversion operator templates are considered potentially \" \"viable in C++1y\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303373/tools/clang/lib/Sema/SemaOverload.cpp"
, 5693, __PRETTY_FUNCTION__))
5693 "viable in C++1y")(((!ConvTemplate || getLangOpts().CPlusPlus14) && "Conversion operator templates are considered potentially "
"viable in C++1y") ? static_cast<void> (0) : __assert_fail
("(!ConvTemplate || getLangOpts().CPlusPlus14) && \"Conversion operator templates are considered potentially \" \"viable in C++1y\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303373/tools/clang/lib/Sema/SemaOverload.cpp"
, 5693, __PRETTY_FUNCTION__))
;
5694
5695 QualType CurToType = Conversion->getConversionType().getNonReferenceType();
5696 if (Converter.match(CurToType) || ConvTemplate) {
5697
5698 if (Conversion->isExplicit()) {
5699 // FIXME: For C++1y, do we need this restriction?
5700 // cf. diagnoseNoViableConversion()
5701 if (!ConvTemplate)
5702 ExplicitConversions.addDecl(I.getDecl(), I.getAccess());
5703 } else {
5704 if (!ConvTemplate && getLangOpts().CPlusPlus14) {
5705 if (ToType.isNull())
5706 ToType = CurToType.getUnqualifiedType();
5707 else if (HasUniqueTargetType &&
5708 (CurToType.getUnqualifiedType() != ToType))
5709 HasUniqueTargetType = false;
5710 }
5711 ViableConversions.addDecl(I.getDecl(), I.getAccess());
5712 }
5713 }
5714 }
5715
5716 if (getLangOpts().CPlusPlus14) {
5717 // C++1y [conv]p6:
5718 // ... An expression e of class type E appearing in such a context
5719 // is said to be contextually implicitly converted to a specified
5720 // type T and is well-formed if and only if e can be implicitly
5721 // converted to a type T that is determined as follows: E is searched
5722 // for conversion functions whose return type is cv T or reference to
5723 // cv T such that T is allowed by the context. There shall be
5724 // exactly one such T.
5725
5726 // If no unique T is found:
5727 if (ToType.isNull()) {
5728 if (diagnoseNoViableConversion(*this, Loc, From, Converter, T,
5729 HadMultipleCandidates,
5730 ExplicitConversions))
5731 return ExprError();
5732 return finishContextualImplicitConversion(*this, Loc, From, Converter);
5733 }
5734
5735 // If more than one unique Ts are found:
5736 if (!HasUniqueTargetType)
5737 return diagnoseAmbiguousConversion(*this, Loc, From, Converter, T,
5738 ViableConversions);
5739
5740 // If one unique T is found:
5741 // First, build a candidate set from the previously recorded
5742 // potentially viable conversions.
5743 OverloadCandidateSet CandidateSet(Loc, OverloadCandidateSet::CSK_Normal);
5744 collectViableConversionCandidates(*this, From, ToType, ViableConversions,
5745 CandidateSet);
5746
5747 // Then, perform overload resolution over the candidate set.
5748 OverloadCandidateSet::iterator Best;
5749 switch (CandidateSet.BestViableFunction(*this, Loc, Best)) {
5750 case OR_Success: {
5751 // Apply this conversion.
5752 DeclAccessPair Found =
5753 DeclAccessPair::make(Best->Function, Best->FoundDecl.getAccess());
5754 if (recordConversion(*this, Loc, From, Converter, T,
5755 HadMultipleCandidates, Found))
5756 return ExprError();
5757 break;
5758 }
5759 case OR_Ambiguous:
5760 return diagnoseAmbiguousConversion(*this, Loc, From, Converter, T,
5761 ViableConversions);
5762 case OR_No_Viable_Function:
5763 if (diagnoseNoViableConversion(*this, Loc, From, Converter, T,
5764 HadMultipleCandidates,
5765 ExplicitConversions))
5766 return ExprError();
5767 // fall through 'OR_Deleted' case.
5768 case OR_Deleted:
5769 // We'll complain below about a non-integral condition type.
5770 break;
5771 }
5772 } else {
5773 switch (ViableConversions.size()) {
5774 case 0: {
5775 if (diagnoseNoViableConversion(*this, Loc, From, Converter, T,
5776 HadMultipleCandidates,
5777 ExplicitConversions))
5778 return ExprError();
5779
5780 // We'll complain below about a non-integral condition type.
5781 break;
5782 }
5783 case 1: {
5784 // Apply this conversion.
5785 DeclAccessPair Found = ViableConversions[0];
5786 if (recordConversion(*this, Loc, From, Converter, T,
5787 HadMultipleCandidates, Found))
5788 return ExprError();
5789 break;
5790 }
5791 default:
5792 return diagnoseAmbiguousConversion(*this, Loc, From, Converter, T,
5793 ViableConversions);
5794 }
5795 }
5796
5797 return finishContextualImplicitConversion(*this, Loc, From, Converter);
5798}
5799
5800/// IsAcceptableNonMemberOperatorCandidate - Determine whether Fn is
5801/// an acceptable non-member overloaded operator for a call whose
5802/// arguments have types T1 (and, if non-empty, T2). This routine
5803/// implements the check in C++ [over.match.oper]p3b2 concerning
5804/// enumeration types.
5805static bool IsAcceptableNonMemberOperatorCandidate(ASTContext &Context,
5806 FunctionDecl *Fn,
5807 ArrayRef<Expr *> Args) {
5808 QualType T1 = Args[0]->getType();
5809 QualType T2 = Args.size() > 1 ? Args[1]->getType() : QualType();
5810
5811 if (T1->isDependentType() || (!T2.isNull() && T2->isDependentType()))
5812 return true;
5813
5814 if (T1->isRecordType() || (!T2.isNull() && T2->isRecordType()))
5815 return true;
5816
5817 const FunctionProtoType *Proto = Fn->getType()->getAs<FunctionProtoType>();
5818 if (Proto->getNumParams() < 1)
5819 return false;
5820
5821 if (T1->isEnumeralType()) {
5822 QualType ArgType = Proto->getParamType(0).getNonReferenceType();
5823 if (Context.hasSameUnqualifiedType(T1, ArgType))
5824 return true;
5825 }
5826
5827 if (Proto->getNumParams() < 2)
5828 return false;
5829
5830 if (!T2.isNull() && T2->isEnumeralType()) {
5831 QualType ArgType = Proto->getParamType(1).getNonReferenceType();
5832 if (Context.hasSameUnqualifiedType(T2, ArgType))
5833 return true;
5834 }
5835
5836 return false;
5837}
5838
5839/// AddOverloadCandidate - Adds the given function to the set of
5840/// candidate functions, using the given function call arguments. If
5841/// @p SuppressUserConversions, then don't allow user-defined
5842/// conversions via constructors or conversion operators.
5843///
5844/// \param PartialOverloading true if we are performing "partial" overloading
5845/// based on an incomplete set of function arguments. This feature is used by
5846/// code completion.
5847void
5848Sema::AddOverloadCandidate(FunctionDecl *Function,
5849 DeclAccessPair FoundDecl,
5850 ArrayRef<Expr *> Args,
5851 OverloadCandidateSet &CandidateSet,
5852 bool SuppressUserConversions,
5853 bool PartialOverloading,
5854 bool AllowExplicit,
5855 ConversionSequenceList EarlyConversions) {
5856 const FunctionProtoType *Proto
5857 = dyn_cast<FunctionProtoType>(Function->getType()->getAs<FunctionType>());
5858 assert(Proto && "Functions without a prototype cannot be overloaded")((Proto && "Functions without a prototype cannot be overloaded"
) ? static_cast<void> (0) : __assert_fail ("Proto && \"Functions without a prototype cannot be overloaded\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303373/tools/clang/lib/Sema/SemaOverload.cpp"
, 5858, __PRETTY_FUNCTION__))
;
5859 assert(!Function->getDescribedFunctionTemplate() &&((!Function->getDescribedFunctionTemplate() && "Use AddTemplateOverloadCandidate for function templates"
) ? static_cast<void> (0) : __assert_fail ("!Function->getDescribedFunctionTemplate() && \"Use AddTemplateOverloadCandidate for function templates\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303373/tools/clang/lib/Sema/SemaOverload.cpp"
, 5860, __PRETTY_FUNCTION__))
5860 "Use AddTemplateOverloadCandidate for function templates")((!Function->getDescribedFunctionTemplate() && "Use AddTemplateOverloadCandidate for function templates"
) ? static_cast<void> (0) : __assert_fail ("!Function->getDescribedFunctionTemplate() && \"Use AddTemplateOverloadCandidate for function templates\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303373/tools/clang/lib/Sema/SemaOverload.cpp"
, 5860, __PRETTY_FUNCTION__))
;
5861
5862 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Function)) {
5863 if (!isa<CXXConstructorDecl>(Method)) {
5864 // If we get here, it's because we're calling a member function
5865 // that is named without a member access expression (e.g.,
5866 // "this->f") that was either written explicitly or created
5867 // implicitly. This can happen with a qualified call to a member
5868 // function, e.g., X::f(). We use an empty type for the implied
5869 // object argument (C++ [over.call.func]p3), and the acting context
5870 // is irrelevant.
5871 AddMethodCandidate(Method, FoundDecl, Method->getParent(), QualType(),
5872 Expr::Classification::makeSimpleLValue(), Args,
5873 CandidateSet, SuppressUserConversions,
5874 PartialOverloading, EarlyConversions);
5875 return;
5876 }
5877 // We treat a constructor like a non-member function, since its object
5878 // argument doesn't participate in overload resolution.
5879 }
5880
5881 if (!CandidateSet.isNewCandidate(Function))
5882 return;
5883
5884 // C++ [over.match.oper]p3:
5885 // if no operand has a class type, only those non-member functions in the
5886 // lookup set that have a first parameter of type T1 or "reference to
5887 // (possibly cv-qualified) T1", when T1 is an enumeration type, or (if there
5888 // is a right operand) a second parameter of type T2 or "reference to
5889 // (possibly cv-qualified) T2", when T2 is an enumeration type, are
5890 // candidate functions.
5891 if (CandidateSet.getKind() == OverloadCandidateSet::CSK_Operator &&
5892 !IsAcceptableNonMemberOperatorCandidate(Context, Function, Args))
5893 return;
5894
5895 // C++11 [class.copy]p11: [DR1402]
5896 // A defaulted move constructor that is defined as deleted is ignored by
5897 // overload resolution.
5898 CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(Function);
5899 if (Constructor && Constructor->isDefaulted() && Constructor->isDeleted() &&
5900 Constructor->isMoveConstructor())
5901 return;
5902
5903 // Overload resolution is always an unevaluated context.
5904 EnterExpressionEvaluationContext Unevaluated(
5905 *this, Sema::ExpressionEvaluationContext::Unevaluated);
5906
5907 // Add this candidate
5908 OverloadCandidate &Candidate =
5909 CandidateSet.addCandidate(Args.size(), EarlyConversions);
5910 Candidate.FoundDecl = FoundDecl;
5911 Candidate.Function = Function;
5912 Candidate.Viable = true;
5913 Candidate.IsSurrogate = false;
5914 Candidate.IgnoreObjectArgument = false;
5915 Candidate.ExplicitCallArguments = Args.size();
5916
5917 if (Constructor) {
5918 // C++ [class.copy]p3:
5919 // A member function template is never instantiated to perform the copy
5920 // of a class object to an object of its class type.
5921 QualType ClassType = Context.getTypeDeclType(Constructor->getParent());
5922 if (Args.size() == 1 && Constructor->isSpecializationCopyingObject() &&
5923 (Context.hasSameUnqualifiedType(ClassType, Args[0]->getType()) ||
5924 IsDerivedFrom(Args[0]->getLocStart(), Args[0]->getType(),
5925 ClassType))) {
5926 Candidate.Viable = false;
5927 Candidate.FailureKind = ovl_fail_illegal_constructor;
5928 return;
5929 }
5930
5931 // C++ [over.match.funcs]p8: (proposed DR resolution)
5932 // A constructor inherited from class type C that has a first parameter
5933 // of type "reference to P" (including such a constructor instantiated
5934 // from a template) is excluded from the set of candidate functions when
5935 // constructing an object of type cv D if the argument list has exactly
5936 // one argument and D is reference-related to P and P is reference-related
5937 // to C.
5938 auto *Shadow = dyn_cast<ConstructorUsingShadowDecl>(FoundDecl.getDecl());
5939 if (Shadow && Args.size() == 1 && Constructor->getNumParams() >= 1 &&
5940 Constructor->getParamDecl(0)->getType()->isReferenceType()) {
5941 QualType P = Constructor->getParamDecl(0)->getType()->getPointeeType();
5942 QualType C = Context.getRecordType(Constructor->getParent());
5943 QualType D = Context.getRecordType(Shadow->getParent());
5944 SourceLocation Loc = Args.front()->getExprLoc();
5945 if ((Context.hasSameUnqualifiedType(P, C) || IsDerivedFrom(Loc, P, C)) &&
5946 (Context.hasSameUnqualifiedType(D, P) || IsDerivedFrom(Loc, D, P))) {
5947 Candidate.Viable = false;
5948 Candidate.FailureKind = ovl_fail_inhctor_slice;
5949 return;
5950 }
5951 }
5952 }
5953
5954 unsigned NumParams = Proto->getNumParams();
5955
5956 // (C++ 13.3.2p2): A candidate function having fewer than m
5957 // parameters is viable only if it has an ellipsis in its parameter
5958 // list (8.3.5).
5959 if (TooManyArguments(NumParams, Args.size(), PartialOverloading) &&
5960 !Proto->isVariadic()) {
5961 Candidate.Viable = false;
5962 Candidate.FailureKind = ovl_fail_too_many_arguments;
5963 return;
5964 }
5965
5966 // (C++ 13.3.2p2): A candidate function having more than m parameters
5967 // is viable only if the (m+1)st parameter has a default argument
5968 // (8.3.6). For the purposes of overload resolution, the
5969 // parameter list is truncated on the right, so that there are
5970 // exactly m parameters.
5971 unsigned MinRequiredArgs = Function->getMinRequiredArguments();
5972 if (Args.size() < MinRequiredArgs && !PartialOverloading) {
5973 // Not enough arguments.
5974 Candidate.Viable = false;
5975 Candidate.FailureKind = ovl_fail_too_few_arguments;
5976 return;
5977 }
5978
5979 // (CUDA B.1): Check for invalid calls between targets.
5980 if (getLangOpts().CUDA)
5981 if (const FunctionDecl *Caller = dyn_cast<FunctionDecl>(CurContext))
5982 // Skip the check for callers that are implicit members, because in this
5983 // case we may not yet know what the member's target is; the target is
5984 // inferred for the member automatically, based on the bases and fields of
5985 // the class.
5986 if (!Caller->isImplicit() && !IsAllowedCUDACall(Caller, Function)) {
5987 Candidate.Viable = false;
5988 Candidate.FailureKind = ovl_fail_bad_target;
5989 return;
5990 }
5991
5992 // Determine the implicit conversion sequences for each of the
5993 // arguments.
5994 for (unsigned ArgIdx = 0; ArgIdx < Args.size(); ++ArgIdx) {
5995 if (Candidate.Conversions[ArgIdx].isInitialized()) {
5996 // We already formed a conversion sequence for this parameter during
5997 // template argument deduction.
5998 } else if (ArgIdx < NumParams) {
5999 // (C++ 13.3.2p3): for F to be a viable function, there shall
6000 // exist for each argument an implicit conversion sequence
6001 // (13.3.3.1) that converts that argument to the corresponding
6002 // parameter of F.
6003 QualType ParamType = Proto->getParamType(ArgIdx);
6004 Candidate.Conversions[ArgIdx]
6005 = TryCopyInitialization(*this, Args[ArgIdx], ParamType,
6006 SuppressUserConversions,
6007 /*InOverloadResolution=*/true,
6008 /*AllowObjCWritebackConversion=*/
6009 getLangOpts().ObjCAutoRefCount,
6010 AllowExplicit);
6011 if (Candidate.Conversions[ArgIdx].isBad()) {
6012 Candidate.Viable = false;
6013 Candidate.FailureKind = ovl_fail_bad_conversion;
6014 return;
6015 }
6016 } else {
6017 // (C++ 13.3.2p2): For the purposes of overload resolution, any
6018 // argument for which there is no corresponding parameter is
6019 // considered to ""match the ellipsis" (C+ 13.3.3.1.3).
6020 Candidate.Conversions[ArgIdx].setEllipsis();
6021 }
6022 }
6023
6024 if (EnableIfAttr *FailedAttr = CheckEnableIf(Function, Args)) {
6025 Candidate.Viable = false;
6026 Candidate.FailureKind = ovl_fail_enable_if;
6027 Candidate.DeductionFailure.Data = FailedAttr;
6028 return;
6029 }
6030
6031 if (LangOpts.OpenCL && isOpenCLDisabledDecl(Function)) {
6032 Candidate.Viable = false;
6033 Candidate.FailureKind = ovl_fail_ext_disabled;
6034 return;
6035 }
6036}
6037
6038ObjCMethodDecl *
6039Sema::SelectBestMethod(Selector Sel, MultiExprArg Args, bool IsInstance,
6040 SmallVectorImpl<ObjCMethodDecl *> &Methods) {
6041 if (Methods.size() <= 1)
6042 return nullptr;
6043
6044 for (unsigned b = 0, e = Methods.size(); b < e; b++) {
6045 bool Match = true;
6046 ObjCMethodDecl *Method = Methods[b];
6047 unsigned NumNamedArgs = Sel.getNumArgs();
6048 // Method might have more arguments than selector indicates. This is due
6049 // to addition of c-style arguments in method.
6050 if (Method->param_size() > NumNamedArgs)
6051 NumNamedArgs = Method->param_size();
6052 if (Args.size() < NumNamedArgs)
6053 continue;
6054
6055 for (unsigned i = 0; i < NumNamedArgs; i++) {
6056 // We can't do any type-checking on a type-dependent argument.
6057 if (Args[i]->isTypeDependent()) {
6058 Match = false;
6059 break;
6060 }
6061
6062 ParmVarDecl *param = Method->parameters()[i];
6063 Expr *argExpr = Args[i];
6064 assert(argExpr && "SelectBestMethod(): missing expression")((argExpr && "SelectBestMethod(): missing expression"
) ? static_cast<void> (0) : __assert_fail ("argExpr && \"SelectBestMethod(): missing expression\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303373/tools/clang/lib/Sema/SemaOverload.cpp"
, 6064, __PRETTY_FUNCTION__))
;
6065
6066 // Strip the unbridged-cast placeholder expression off unless it's
6067 // a consumed argument.
6068 if (argExpr->hasPlaceholderType(BuiltinType::ARCUnbridgedCast) &&
6069 !param->hasAttr<CFConsumedAttr>())
6070 argExpr = stripARCUnbridgedCast(argExpr);
6071
6072 // If the parameter is __unknown_anytype, move on to the next method.
6073 if (param->getType() == Context.UnknownAnyTy) {
6074 Match = false;
6075 break;
6076 }
6077
6078 ImplicitConversionSequence ConversionState
6079 = TryCopyInitialization(*this, argExpr, param->getType(),
6080 /*SuppressUserConversions*/false,
6081 /*InOverloadResolution=*/true,
6082 /*AllowObjCWritebackConversion=*/
6083 getLangOpts().ObjCAutoRefCount,
6084 /*AllowExplicit*/false);
6085 // This function looks for a reasonably-exact match, so we consider
6086 // incompatible pointer conversions to be a failure here.
6087 if (ConversionState.isBad() ||
6088 (ConversionState.isStandard() &&
6089 ConversionState.Standard.Second ==
6090 ICK_Incompatible_Pointer_Conversion)) {
6091 Match = false;
6092 break;
6093 }
6094 }
6095 // Promote additional arguments to variadic methods.
6096 if (Match && Method->isVariadic()) {
6097 for (unsigned i = NumNamedArgs, e = Args.size(); i < e; ++i) {
6098 if (Args[i]->isTypeDependent()) {
6099 Match = false;
6100 break;
6101 }
6102 ExprResult Arg = DefaultVariadicArgumentPromotion(Args[i], VariadicMethod,
6103 nullptr);
6104 if (Arg.isInvalid()) {
6105 Match = false;
6106 break;
6107 }
6108 }
6109 } else {
6110 // Check for extra arguments to non-variadic methods.
6111 if (Args.size() != NumNamedArgs)
6112 Match = false;
6113 else if (Match && NumNamedArgs == 0 && Methods.size() > 1) {
6114 // Special case when selectors have no argument. In this case, select
6115 // one with the most general result type of 'id'.
6116 for (unsigned b = 0, e = Methods.size(); b < e; b++) {
6117 QualType ReturnT = Methods[b]->getReturnType();
6118 if (ReturnT->isObjCIdType())
6119 return Methods[b];
6120 }
6121 }
6122 }
6123
6124 if (Match)
6125 return Method;
6126 }
6127 return nullptr;
6128}
6129
6130// specific_attr_iterator iterates over enable_if attributes in reverse, and
6131// enable_if is order-sensitive. As a result, we need to reverse things
6132// sometimes. Size of 4 elements is arbitrary.
6133static SmallVector<EnableIfAttr *, 4>
6134getOrderedEnableIfAttrs(const FunctionDecl *Function) {
6135 SmallVector<EnableIfAttr *, 4> Result;
6136 if (!Function->hasAttrs())
6137 return Result;
6138
6139 const auto &FuncAttrs = Function->getAttrs();
6140 for (Attr *Attr : FuncAttrs)
6141 if (auto *EnableIf = dyn_cast<EnableIfAttr>(Attr))
6142 Result.push_back(EnableIf);
6143
6144 std::reverse(Result.begin(), Result.end());
6145 return Result;
6146}
6147
6148static bool
6149convertArgsForAvailabilityChecks(Sema &S, FunctionDecl *Function, Expr *ThisArg,
6150 ArrayRef<Expr *> Args, Sema::SFINAETrap &Trap,
6151 bool MissingImplicitThis, Expr *&ConvertedThis,
6152 SmallVectorImpl<Expr *> &ConvertedArgs) {
6153 if (ThisArg) {
6154 CXXMethodDecl *Method = cast<CXXMethodDecl>(Function);
6155 assert(!isa<CXXConstructorDecl>(Method) &&((!isa<CXXConstructorDecl>(Method) && "Shouldn't have `this` for ctors!"
) ? static_cast<void> (0) : __assert_fail ("!isa<CXXConstructorDecl>(Method) && \"Shouldn't have `this` for ctors!\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303373/tools/clang/lib/Sema/SemaOverload.cpp"
, 6156, __PRETTY_FUNCTION__))
6156 "Shouldn't have `this` for ctors!")((!isa<CXXConstructorDecl>(Method) && "Shouldn't have `this` for ctors!"
) ? static_cast<void> (0) : __assert_fail ("!isa<CXXConstructorDecl>(Method) && \"Shouldn't have `this` for ctors!\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303373/tools/clang/lib/Sema/SemaOverload.cpp"
, 6156, __PRETTY_FUNCTION__))
;
6157 assert(!Method->isStatic() && "Shouldn't have `this` for static methods!")((!Method->isStatic() && "Shouldn't have `this` for static methods!"
) ? static_cast<void> (0) : __assert_fail ("!Method->isStatic() && \"Shouldn't have `this` for static methods!\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303373/tools/clang/lib/Sema/SemaOverload.cpp"
, 6157, __PRETTY_FUNCTION__))
;
6158 ExprResult R = S.PerformObjectArgumentInitialization(
6159 ThisArg, /*Qualifier=*/nullptr, Method, Method);
6160 if (R.isInvalid())
6161 return false;
6162 ConvertedThis = R.get();
6163 } else {
6164 if (auto *MD = dyn_cast<CXXMethodDecl>(Function)) {
6165 (void)MD;
6166 assert((MissingImplicitThis || MD->isStatic() ||(((MissingImplicitThis || MD->isStatic() || isa<CXXConstructorDecl
>(MD)) && "Expected `this` for non-ctor instance methods"
) ? static_cast<void> (0) : __assert_fail ("(MissingImplicitThis || MD->isStatic() || isa<CXXConstructorDecl>(MD)) && \"Expected `this` for non-ctor instance methods\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303373/tools/clang/lib/Sema/SemaOverload.cpp"
, 6168, __PRETTY_FUNCTION__))
6167 isa<CXXConstructorDecl>(MD)) &&(((MissingImplicitThis || MD->isStatic() || isa<CXXConstructorDecl
>(MD)) && "Expected `this` for non-ctor instance methods"
) ? static_cast<void> (0) : __assert_fail ("(MissingImplicitThis || MD->isStatic() || isa<CXXConstructorDecl>(MD)) && \"Expected `this` for non-ctor instance methods\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303373/tools/clang/lib/Sema/SemaOverload.cpp"
, 6168, __PRETTY_FUNCTION__))
6168 "Expected `this` for non-ctor instance methods")(((MissingImplicitThis || MD->isStatic() || isa<CXXConstructorDecl
>(MD)) && "Expected `this` for non-ctor instance methods"
) ? static_cast<void> (0) : __assert_fail ("(MissingImplicitThis || MD->isStatic() || isa<CXXConstructorDecl>(MD)) && \"Expected `this` for non-ctor instance methods\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303373/tools/clang/lib/Sema/SemaOverload.cpp"
, 6168, __PRETTY_FUNCTION__))
;
6169 }
6170 ConvertedThis = nullptr;
6171 }
6172
6173 // Ignore any variadic arguments. Converting them is pointless, since the
6174 // user can't refer to them in the function condition.
6175 unsigned ArgSizeNoVarargs = std::min(Function->param_size(), Args.size());
6176
6177 // Convert the arguments.
6178 for (unsigned I = 0; I != ArgSizeNoVarargs; ++I) {
6179 ExprResult R;
6180 R = S.PerformCopyInitialization(InitializedEntity::InitializeParameter(
6181 S.Context, Function->getParamDecl(I)),
6182 SourceLocation(), Args[I]);
6183
6184 if (R.isInvalid())
6185 return false;
6186
6187 ConvertedArgs.push_back(R.get());
6188 }
6189
6190 if (Trap.hasErrorOccurred())
6191 return false;
6192
6193 // Push default arguments if needed.
6194 if (!Function->isVariadic() && Args.size() < Function->getNumParams()) {
6195 for (unsigned i = Args.size(), e = Function->getNumParams(); i != e; ++i) {
6196 ParmVarDecl *P = Function->getParamDecl(i);
6197 ExprResult R = S.PerformCopyInitialization(
6198 InitializedEntity::InitializeParameter(S.Context,
6199 Function->getParamDecl(i)),
6200 SourceLocation(),
6201 P->hasUninstantiatedDefaultArg() ? P->getUninstantiatedDefaultArg()
6202 : P->getDefaultArg());
6203 if (R.isInvalid())
6204 return false;
6205 ConvertedArgs.push_back(R.get());
6206 }
6207
6208 if (Trap.hasErrorOccurred())
6209 return false;
6210 }
6211 return true;
6212}
6213
6214EnableIfAttr *Sema::CheckEnableIf(FunctionDecl *Function, ArrayRef<Expr *> Args,
6215 bool MissingImplicitThis) {
6216 SmallVector<EnableIfAttr *, 4> EnableIfAttrs =
6217 getOrderedEnableIfAttrs(Function);
6218 if (EnableIfAttrs.empty())
6219 return nullptr;
6220
6221 SFINAETrap Trap(*this);
6222 SmallVector<Expr *, 16> ConvertedArgs;
6223 // FIXME: We should look into making enable_if late-parsed.
6224 Expr *DiscardedThis;
6225 if (!convertArgsForAvailabilityChecks(
6226 *this, Function, /*ThisArg=*/nullptr, Args, Trap,
6227 /*MissingImplicitThis=*/true, DiscardedThis, ConvertedArgs))
6228 return EnableIfAttrs[0];
6229
6230 for (auto *EIA : EnableIfAttrs) {
6231 APValue Result;
6232 // FIXME: This doesn't consider value-dependent cases, because doing so is
6233 // very difficult. Ideally, we should handle them more gracefully.
6234 if (!EIA->getCond()->EvaluateWithSubstitution(
6235 Result, Context, Function, llvm::makeArrayRef(ConvertedArgs)))
6236 return EIA;
6237
6238 if (!Result.isInt() || !Result.getInt().getBoolValue())
6239 return EIA;
6240 }
6241 return nullptr;
6242}
6243
6244template <typename CheckFn>
6245static bool diagnoseDiagnoseIfAttrsWith(Sema &S, const FunctionDecl *FD,
6246 bool ArgDependent, SourceLocation Loc,
6247 CheckFn &&IsSuccessful) {
6248 SmallVector<const DiagnoseIfAttr *, 8> Attrs;
6249 for (const auto *DIA : FD->specific_attrs<DiagnoseIfAttr>()) {
6250 if (ArgDependent == DIA->getArgDependent())
6251 Attrs.push_back(DIA);
6252 }
6253
6254 // Common case: No diagnose_if attributes, so we can quit early.
6255 if (Attrs.empty())
6256 return false;
6257
6258 auto WarningBegin = std::stable_partition(
6259 Attrs.begin(), Attrs.end(),
6260 [](const DiagnoseIfAttr *DIA) { return DIA->isError(); });
6261
6262 // Note that diagnose_if attributes are late-parsed, so they appear in the
6263 // correct order (unlike enable_if attributes).
6264 auto ErrAttr = llvm::find_if(llvm::make_range(Attrs.begin(), WarningBegin),
6265 IsSuccessful);
6266 if (ErrAttr != WarningBegin) {
6267 const DiagnoseIfAttr *DIA = *ErrAttr;
6268 S.Diag(Loc, diag::err_diagnose_if_succeeded) << DIA->getMessage();
6269 S.Diag(DIA->getLocation(), diag::note_from_diagnose_if)
6270 << DIA->getParent() << DIA->getCond()->getSourceRange();
6271 return true;
6272 }
6273
6274 for (const auto *DIA : llvm::make_range(WarningBegin, Attrs.end()))
6275 if (IsSuccessful(DIA)) {
6276 S.Diag(Loc, diag::warn_diagnose_if_succeeded) << DIA->getMessage();
6277 S.Diag(DIA->getLocation(), diag::note_from_diagnose_if)
6278 << DIA->getParent() << DIA->getCond()->getSourceRange();
6279 }
6280
6281 return false;
6282}
6283
6284bool Sema::diagnoseArgDependentDiagnoseIfAttrs(const FunctionDecl *Function,
6285 const Expr *ThisArg,
6286 ArrayRef<const Expr *> Args,
6287 SourceLocation Loc) {
6288 return diagnoseDiagnoseIfAttrsWith(
6289 *this, Function, /*ArgDependent=*/true, Loc,
6290 [&](const DiagnoseIfAttr *DIA) {
6291 APValue Result;
6292 // It's sane to use the same Args for any redecl of this function, since
6293 // EvaluateWithSubstitution only cares about the position of each
6294 // argument in the arg list, not the ParmVarDecl* it maps to.
6295 if (!DIA->getCond()->EvaluateWithSubstitution(
6296 Result, Context, DIA->getParent(), Args, ThisArg))
6297 return false;
6298 return Result.isInt() && Result.getInt().getBoolValue();
6299 });
6300}
6301
6302bool Sema::diagnoseArgIndependentDiagnoseIfAttrs(const FunctionDecl *Function,
6303 SourceLocation Loc) {
6304 return diagnoseDiagnoseIfAttrsWith(
6305 *this, Function, /*ArgDependent=*/false, Loc,
6306 [&](const DiagnoseIfAttr *DIA) {
6307 bool Result;
6308 return DIA->getCond()->EvaluateAsBooleanCondition(Result, Context) &&
6309 Result;
6310 });
6311}
6312
6313/// \brief Add all of the function declarations in the given function set to
6314/// the overload candidate set.
6315void Sema::AddFunctionCandidates(const UnresolvedSetImpl &Fns,
6316 ArrayRef<Expr *> Args,
6317 OverloadCandidateSet& CandidateSet,
6318 TemplateArgumentListInfo *ExplicitTemplateArgs,
6319 bool SuppressUserConversions,
6320 bool PartialOverloading) {
6321 for (UnresolvedSetIterator F = Fns.begin(), E = Fns.end(); F != E; ++F) {
6322 NamedDecl *D = F.getDecl()->getUnderlyingDecl();
6323 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
6324 if (isa<CXXMethodDecl>(FD) && !cast<CXXMethodDecl>(FD)->isStatic()) {
6325 QualType ObjectType;
6326 Expr::Classification ObjectClassification;
6327 if (Expr *E = Args[0]) {
6328 // Use the explit base to restrict the lookup:
6329 ObjectType = E->getType();
6330 ObjectClassification = E->Classify(Context);
6331 } // .. else there is an implit base.
6332 AddMethodCandidate(cast<CXXMethodDecl>(FD), F.getPair(),
6333 cast<CXXMethodDecl>(FD)->getParent(), ObjectType,
6334 ObjectClassification, Args.slice(1), CandidateSet,
6335 SuppressUserConversions, PartialOverloading);
6336 } else {
6337 AddOverloadCandidate(FD, F.getPair(), Args, CandidateSet,
6338 SuppressUserConversions, PartialOverloading);
6339 }
6340 } else {
6341 FunctionTemplateDecl *FunTmpl = cast<FunctionTemplateDecl>(D);
6342 if (isa<CXXMethodDecl>(FunTmpl->getTemplatedDecl()) &&
6343 !cast<CXXMethodDecl>(FunTmpl->getTemplatedDecl())->isStatic()) {
6344 QualType ObjectType;
6345 Expr::Classification ObjectClassification;
6346 if (Expr *E = Args[0]) {
6347 // Use the explit base to restrict the lookup:
6348 ObjectType = E->getType();
6349 ObjectClassification = E->Classify(Context);
6350 } // .. else there is an implit base.
6351 AddMethodTemplateCandidate(
6352 FunTmpl, F.getPair(),
6353 cast<CXXRecordDecl>(FunTmpl->getDeclContext()),
6354 ExplicitTemplateArgs, ObjectType, ObjectClassification,
6355 Args.slice(1), CandidateSet, SuppressUserConversions,
6356 PartialOverloading);
6357 } else {
6358 AddTemplateOverloadCandidate(FunTmpl, F.getPair(),
6359 ExplicitTemplateArgs, Args,
6360 CandidateSet, SuppressUserConversions,
6361 PartialOverloading);
6362 }
6363 }
6364 }
6365}
6366
6367/// AddMethodCandidate - Adds a named decl (which is some kind of
6368/// method) as a method candidate to the given overload set.
6369void Sema::AddMethodCandidate(DeclAccessPair FoundDecl,
6370 QualType ObjectType,
6371 Expr::Classification ObjectClassification,
6372 ArrayRef<Expr *> Args,
6373 OverloadCandidateSet& CandidateSet,
6374 bool SuppressUserConversions) {
6375 NamedDecl *Decl = FoundDecl.getDecl();
6376 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(Decl->getDeclContext());
6377
6378 if (isa<UsingShadowDecl>(Decl))
6379 Decl = cast<UsingShadowDecl>(Decl)->getTargetDecl();
6380
6381 if (FunctionTemplateDecl *TD = dyn_cast<FunctionTemplateDecl>(Decl)) {
6382 assert(isa<CXXMethodDecl>(TD->getTemplatedDecl()) &&((isa<CXXMethodDecl>(TD->getTemplatedDecl()) &&
"Expected a member function template") ? static_cast<void
> (0) : __assert_fail ("isa<CXXMethodDecl>(TD->getTemplatedDecl()) && \"Expected a member function template\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303373/tools/clang/lib/Sema/SemaOverload.cpp"
, 6383, __PRETTY_FUNCTION__))
6383 "Expected a member function template")((isa<CXXMethodDecl>(TD->getTemplatedDecl()) &&
"Expected a member function template") ? static_cast<void
> (0) : __assert_fail ("isa<CXXMethodDecl>(TD->getTemplatedDecl()) && \"Expected a member function template\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303373/tools/clang/lib/Sema/SemaOverload.cpp"
, 6383, __PRETTY_FUNCTION__))
;
6384 AddMethodTemplateCandidate(TD, FoundDecl, ActingContext,
6385 /*ExplicitArgs*/ nullptr, ObjectType,
6386 ObjectClassification, Args, CandidateSet,
6387 SuppressUserConversions);
6388 } else {
6389 AddMethodCandidate(cast<CXXMethodDecl>(Decl), FoundDecl, ActingContext,
6390 ObjectType, ObjectClassification, Args, CandidateSet,
6391 SuppressUserConversions);
6392 }
6393}
6394
6395/// AddMethodCandidate - Adds the given C++ member function to the set
6396/// of candidate functions, using the given function call arguments
6397/// and the object argument (@c Object). For example, in a call
6398/// @c o.f(a1,a2), @c Object will contain @c o and @c Args will contain
6399/// both @c a1 and @c a2. If @p SuppressUserConversions, then don't
6400/// allow user-defined conversions via constructors or conversion
6401/// operators.
6402void
6403Sema::AddMethodCandidate(CXXMethodDecl *Method, DeclAccessPair FoundDecl,
6404 CXXRecordDecl *ActingContext, QualType ObjectType,
6405 Expr::Classification ObjectClassification,
6406 ArrayRef<Expr *> Args,
6407 OverloadCandidateSet &CandidateSet,
6408 bool SuppressUserConversions,
6409 bool PartialOverloading,
6410 ConversionSequenceList EarlyConversions) {
6411 const FunctionProtoType *Proto
6412 = dyn_cast<FunctionProtoType>(Method->getType()->getAs<FunctionType>());
6413 assert(Proto && "Methods without a prototype cannot be overloaded")((Proto && "Methods without a prototype cannot be overloaded"
) ? static_cast<void> (0) : __assert_fail ("Proto && \"Methods without a prototype cannot be overloaded\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303373/tools/clang/lib/Sema/SemaOverload.cpp"
, 6413, __PRETTY_FUNCTION__))
;
6414 assert(!isa<CXXConstructorDecl>(Method) &&((!isa<CXXConstructorDecl>(Method) && "Use AddOverloadCandidate for constructors"
) ? static_cast<void> (0) : __assert_fail ("!isa<CXXConstructorDecl>(Method) && \"Use AddOverloadCandidate for constructors\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303373/tools/clang/lib/Sema/SemaOverload.cpp"
, 6415, __PRETTY_FUNCTION__))
6415 "Use AddOverloadCandidate for constructors")((!isa<CXXConstructorDecl>(Method) && "Use AddOverloadCandidate for constructors"
) ? static_cast<void> (0) : __assert_fail ("!isa<CXXConstructorDecl>(Method) && \"Use AddOverloadCandidate for constructors\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303373/tools/clang/lib/Sema/SemaOverload.cpp"
, 6415, __PRETTY_FUNCTION__))
;
6416
6417 if (!CandidateSet.isNewCandidate(Method))
6418 return;
6419
6420 // C++11 [class.copy]p23: [DR1402]
6421 // A defaulted move assignment operator that is defined as deleted is
6422 // ignored by overload resolution.
6423 if (Method->isDefaulted() && Method->isDeleted() &&
6424 Method->isMoveAssignmentOperator())
6425 return;
6426
6427 // Overload resolution is always an unevaluated context.
6428 EnterExpressionEvaluationContext Unevaluated(
6429 *this, Sema::ExpressionEvaluationContext::Unevaluated);
6430
6431 // Add this candidate
6432 OverloadCandidate &Candidate =
6433 CandidateSet.addCandidate(Args.size() + 1, EarlyConversions);
6434 Candidate.FoundDecl = FoundDecl;
6435 Candidate.Function = Method;
6436 Candidate.IsSurrogate = false;
6437 Candidate.IgnoreObjectArgument = false;
6438 Candidate.ExplicitCallArguments = Args.size();
6439
6440 unsigned NumParams = Proto->getNumParams();
6441
6442 // (C++ 13.3.2p2): A candidate function having fewer than m
6443 // parameters is viable only if it has an ellipsis in its parameter
6444 // list (8.3.5).
6445 if (TooManyArguments(NumParams, Args.size(), PartialOverloading) &&
6446 !Proto->isVariadic()) {
6447 Candidate.Viable = false;
6448 Candidate.FailureKind = ovl_fail_too_many_arguments;
6449 return;
6450 }
6451
6452 // (C++ 13.3.2p2): A candidate function having more than m parameters
6453 // is viable only if the (m+1)st parameter has a default argument
6454 // (8.3.6). For the purposes of overload resolution, the
6455 // parameter list is truncated on the right, so that there are
6456 // exactly m parameters.
6457 unsigned MinRequiredArgs = Method->getMinRequiredArguments();
6458 if (Args.size() < MinRequiredArgs && !PartialOverloading) {
6459 // Not enough arguments.
6460 Candidate.Viable = false;
6461 Candidate.FailureKind = ovl_fail_too_few_arguments;
6462 return;
6463 }
6464
6465 Candidate.Viable = true;
6466
6467 if (Method->isStatic() || ObjectType.isNull())
6468 // The implicit object argument is ignored.
6469 Candidate.IgnoreObjectArgument = true;
6470 else {
6471 // Determine the implicit conversion sequence for the object
6472 // parameter.
6473 Candidate.Conversions[0] = TryObjectArgumentInitialization(
6474 *this, CandidateSet.getLocation(), ObjectType, ObjectClassification,
6475 Method, ActingContext);
6476 if (Candidate.Conversions[0].isBad()) {
6477 Candidate.Viable = false;
6478 Candidate.FailureKind = ovl_fail_bad_conversion;
6479 return;
6480 }
6481 }
6482
6483 // (CUDA B.1): Check for invalid calls between targets.
6484 if (getLangOpts().CUDA)
6485 if (const FunctionDecl *Caller = dyn_cast<FunctionDecl>(CurContext))
6486 if (!IsAllowedCUDACall(Caller, Method)) {
6487 Candidate.Viable = false;
6488 Candidate.FailureKind = ovl_fail_bad_target;
6489 return;
6490 }
6491
6492 // Determine the implicit conversion sequences for each of the
6493 // arguments.
6494 for (unsigned ArgIdx = 0; ArgIdx < Args.size(); ++ArgIdx) {
6495 if (Candidate.Conversions[ArgIdx + 1].isInitialized()) {
6496 // We already formed a conversion sequence for this parameter during
6497 // template argument deduction.
6498 } else if (ArgIdx < NumParams) {
6499 // (C++ 13.3.2p3): for F to be a viable function, there shall
6500 // exist for each argument an implicit conversion sequence
6501 // (13.3.3.1) that converts that argument to the corresponding
6502 // parameter of F.
6503 QualType ParamType = Proto->getParamType(ArgIdx);
6504 Candidate.Conversions[ArgIdx + 1]
6505 = TryCopyInitialization(*this, Args[ArgIdx], ParamType,
6506 SuppressUserConversions,
6507 /*InOverloadResolution=*/true,
6508 /*AllowObjCWritebackConversion=*/
6509 getLangOpts().ObjCAutoRefCount);
6510 if (Candidate.Conversions[ArgIdx + 1].isBad()) {
6511 Candidate.Viable = false;
6512 Candidate.FailureKind = ovl_fail_bad_conversion;
6513 return;
6514 }
6515 } else {
6516 // (C++ 13.3.2p2): For the purposes of overload resolution, any
6517 // argument for which there is no corresponding parameter is
6518 // considered to "match the ellipsis" (C+ 13.3.3.1.3).
6519 Candidate.Conversions[ArgIdx + 1].setEllipsis();
6520 }
6521 }
6522
6523 if (EnableIfAttr *FailedAttr = CheckEnableIf(Method, Args, true)) {
6524 Candidate.Viable = false;
6525 Candidate.FailureKind = ovl_fail_enable_if;
6526 Candidate.DeductionFailure.Data = FailedAttr;
6527 return;
6528 }
6529}
6530
6531/// \brief Add a C++ member function template as a candidate to the candidate
6532/// set, using template argument deduction to produce an appropriate member
6533/// function template specialization.
6534void
6535Sema::AddMethodTemplateCandidate(FunctionTemplateDecl *MethodTmpl,
6536 DeclAccessPair FoundDecl,
6537 CXXRecordDecl *ActingContext,
6538 TemplateArgumentListInfo *ExplicitTemplateArgs,
6539 QualType ObjectType,
6540 Expr::Classification ObjectClassification,
6541 ArrayRef<Expr *> Args,
6542 OverloadCandidateSet& CandidateSet,
6543 bool SuppressUserConversions,
6544 bool PartialOverloading) {
6545 if (!CandidateSet.isNewCandidate(MethodTmpl))
6546 return;
6547
6548 // C++ [over.match.funcs]p7:
6549 // In each case where a candidate is a function template, candidate
6550 // function template specializations are generated using template argument
6551 // deduction (14.8.3, 14.8.2). Those candidates are then handled as
6552 // candidate functions in the usual way.113) A given name can refer to one
6553 // or more function templates and also to a set of overloaded non-template
6554 // functions. In such a case, the candidate functions generated from each
6555 // function template are combined with the set of non-template candidate
6556 // functions.
6557 TemplateDeductionInfo Info(CandidateSet.getLocation());
6558 FunctionDecl *Specialization = nullptr;
6559 ConversionSequenceList Conversions;
6560 if (TemplateDeductionResult Result = DeduceTemplateArguments(
6561 MethodTmpl, ExplicitTemplateArgs, Args, Specialization, Info,
6562 PartialOverloading, [&](ArrayRef<QualType> ParamTypes) {
6563 return CheckNonDependentConversions(
6564 MethodTmpl, ParamTypes, Args, CandidateSet, Conversions,
6565 SuppressUserConversions, ActingContext, ObjectType,
6566 ObjectClassification);
6567 })) {
6568 OverloadCandidate &Candidate =
6569 CandidateSet.addCandidate(Conversions.size(), Conversions);
6570 Candidate.FoundDecl = FoundDecl;
6571 Candidate.Function = MethodTmpl->getTemplatedDecl();
6572 Candidate.Viable = false;
6573 Candidate.IsSurrogate = false;
6574 Candidate.IgnoreObjectArgument =
6575 cast<CXXMethodDecl>(Candidate.Function)->isStatic() ||
6576 ObjectType.isNull();
6577 Candidate.ExplicitCallArguments = Args.size();
6578 if (Result == TDK_NonDependentConversionFailure)
6579 Candidate.FailureKind = ovl_fail_bad_conversion;
6580 else {
6581 Candidate.FailureKind = ovl_fail_bad_deduction;
6582 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result,
6583 Info);
6584 }
6585 return;
6586 }
6587
6588 // Add the function template specialization produced by template argument
6589 // deduction as a candidate.
6590 assert(Specialization && "Missing member function template specialization?")((Specialization && "Missing member function template specialization?"
) ? static_cast<void> (0) : __assert_fail ("Specialization && \"Missing member function template specialization?\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303373/tools/clang/lib/Sema/SemaOverload.cpp"
, 6590, __PRETTY_FUNCTION__))
;
6591 assert(isa<CXXMethodDecl>(Specialization) &&((isa<CXXMethodDecl>(Specialization) && "Specialization is not a member function?"
) ? static_cast<void> (0) : __assert_fail ("isa<CXXMethodDecl>(Specialization) && \"Specialization is not a member function?\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303373/tools/clang/lib/Sema/SemaOverload.cpp"
, 6592, __PRETTY_FUNCTION__))
6592 "Specialization is not a member function?")((isa<CXXMethodDecl>(Specialization) && "Specialization is not a member function?"
) ? static_cast<void> (0) : __assert_fail ("isa<CXXMethodDecl>(Specialization) && \"Specialization is not a member function?\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303373/tools/clang/lib/Sema/SemaOverload.cpp"
, 6592, __PRETTY_FUNCTION__))
;
6593 AddMethodCandidate(cast<CXXMethodDecl>(Specialization), FoundDecl,
6594 ActingContext, ObjectType, ObjectClassification, Args,
6595 CandidateSet, SuppressUserConversions, PartialOverloading,
6596 Conversions);
6597}
6598
6599/// \brief Add a C++ function template specialization as a candidate
6600/// in the candidate set, using template argument deduction to produce
6601/// an appropriate function template specialization.
6602void
6603Sema::AddTemplateOverloadCandidate(FunctionTemplateDecl *FunctionTemplate,
6604 DeclAccessPair FoundDecl,
6605 TemplateArgumentListInfo *ExplicitTemplateArgs,
6606 ArrayRef<Expr *> Args,
6607 OverloadCandidateSet& CandidateSet,
6608 bool SuppressUserConversions,
6609 bool PartialOverloading) {
6610 if (!CandidateSet.isNewCandidate(FunctionTemplate))
6611 return;
6612
6613 // C++ [over.match.funcs]p7:
6614 // In each case where a candidate is a function template, candidate
6615 // function template specializations are generated using template argument
6616 // deduction (14.8.3, 14.8.2). Those candidates are then handled as
6617 // candidate functions in the usual way.113) A given name can refer to one
6618 // or more function templates and also to a set of overloaded non-template
6619 // functions. In such a case, the candidate functions generated from each
6620 // function template are combined with the set of non-template candidate
6621 // functions.
6622 TemplateDeductionInfo Info(CandidateSet.getLocation());
6623 FunctionDecl *Specialization = nullptr;
6624 ConversionSequenceList Conversions;
6625 if (TemplateDeductionResult Result = DeduceTemplateArguments(
6626 FunctionTemplate, ExplicitTemplateArgs, Args, Specialization, Info,
6627 PartialOverloading, [&](ArrayRef<QualType> ParamTypes) {
6628 return CheckNonDependentConversions(FunctionTemplate, ParamTypes,
6629 Args, CandidateSet, Conversions,
6630 SuppressUserConversions);
6631 })) {
6632 OverloadCandidate &Candidate =
6633 CandidateSet.addCandidate(Conversions.size(), Conversions);
6634 Candidate.FoundDecl = FoundDecl;
6635 Candidate.Function = FunctionTemplate->getTemplatedDecl();
6636 Candidate.Viable = false;
6637 Candidate.IsSurrogate = false;
6638 // Ignore the object argument if there is one, since we don't have an object
6639 // type.
6640 Candidate.IgnoreObjectArgument =
6641 isa<CXXMethodDecl>(Candidate.Function) &&
6642 !isa<CXXConstructorDecl>(Candidate.Function);
6643 Candidate.ExplicitCallArguments = Args.size();
6644 if (Result == TDK_NonDependentConversionFailure)
6645 Candidate.FailureKind = ovl_fail_bad_conversion;
6646 else {
6647 Candidate.FailureKind = ovl_fail_bad_deduction;
6648 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result,
6649 Info);
6650 }
6651 return;
6652 }
6653
6654 // Add the function template specialization produced by template argument
6655 // deduction as a candidate.
6656 assert(Specialization && "Missing function template specialization?")((Specialization && "Missing function template specialization?"
) ? static_cast<void> (0) : __assert_fail ("Specialization && \"Missing function template specialization?\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303373/tools/clang/lib/Sema/SemaOverload.cpp"
, 6656, __PRETTY_FUNCTION__))
;
6657 AddOverloadCandidate(Specialization, FoundDecl, Args, CandidateSet,
6658 SuppressUserConversions, PartialOverloading,
6659 /*AllowExplicit*/false, Conversions);
6660}
6661
6662/// Check that implicit conversion sequences can be formed for each argument
6663/// whose corresponding parameter has a non-dependent type, per DR1391's
6664/// [temp.deduct.call]p10.
6665bool Sema::CheckNonDependentConversions(
6666 FunctionTemplateDecl *FunctionTemplate, ArrayRef<QualType> ParamTypes,
6667 ArrayRef<Expr *> Args, OverloadCandidateSet &CandidateSet,
6668 ConversionSequenceList &Conversions, bool SuppressUserConversions,
6669 CXXRecordDecl *ActingContext, QualType ObjectType,
6670 Expr::Classification ObjectClassification) {
6671 // FIXME: The cases in which we allow explicit conversions for constructor
6672 // arguments never consider calling a constructor template. It's not clear
6673 // that is correct.
6674 const bool AllowExplicit = false;
6675
6676 auto *FD = FunctionTemplate->getTemplatedDecl();
6677 auto *Method = dyn_cast<CXXMethodDecl>(FD);
6678 bool HasThisConversion = Method && !isa<CXXConstructorDecl>(Method);
6679 unsigned ThisConversions = HasThisConversion ? 1 : 0;
6680
6681 Conversions =
6682 CandidateSet.allocateConversionSequences(ThisConversions + Args.size());
6683
6684 // Overload resolution is always an unevaluated context.
6685 EnterExpressionEvaluationContext Unevaluated(
6686 *this, Sema::ExpressionEvaluationContext::Unevaluated);
6687
6688 // For a method call, check the 'this' conversion here too. DR1391 doesn't
6689 // require that, but this check should never result in a hard error, and
6690 // overload resolution is permitted to sidestep instantiations.
6691 if (HasThisConversion && !cast<CXXMethodDecl>(FD)->isStatic() &&
6692 !ObjectType.isNull()) {
6693 Conversions[0] = TryObjectArgumentInitialization(
6694 *this, CandidateSet.getLocation(), ObjectType, ObjectClassification,
6695 Method, ActingContext);
6696 if (Conversions[0].isBad())
6697 return true;
6698 }
6699
6700 for (unsigned I = 0, N = std::min(ParamTypes.size(), Args.size()); I != N;
6701 ++I) {
6702 QualType ParamType = ParamTypes[I];
6703 if (!ParamType->isDependentType()) {
6704 Conversions[ThisConversions + I]
6705 = TryCopyInitialization(*this, Args[I], ParamType,
6706 SuppressUserConversions,
6707 /*InOverloadResolution=*/true,
6708 /*AllowObjCWritebackConversion=*/
6709 getLangOpts().ObjCAutoRefCount,
6710 AllowExplicit);
6711 if (Conversions[ThisConversions + I].isBad())
6712 return true;
6713 }
6714 }
6715
6716 return false;
6717}
6718
6719/// Determine whether this is an allowable conversion from the result
6720/// of an explicit conversion operator to the expected type, per C++
6721/// [over.match.conv]p1 and [over.match.ref]p1.
6722///
6723/// \param ConvType The return type of the conversion function.
6724///
6725/// \param ToType The type we are converting to.
6726///
6727/// \param AllowObjCPointerConversion Allow a conversion from one
6728/// Objective-C pointer to another.
6729///
6730/// \returns true if the conversion is allowable, false otherwise.
6731static bool isAllowableExplicitConversion(Sema &S,
6732 QualType ConvType, QualType ToType,
6733 bool AllowObjCPointerConversion) {
6734 QualType ToNonRefType = ToType.getNonReferenceType();
6735
6736 // Easy case: the types are the same.
6737 if (S.Context.hasSameUnqualifiedType(ConvType, ToNonRefType))
6738 return true;
6739
6740 // Allow qualification conversions.
6741 bool ObjCLifetimeConversion;
6742 if (S.IsQualificationConversion(ConvType, ToNonRefType, /*CStyle*/false,
6743 ObjCLifetimeConversion))
6744 return true;
6745
6746 // If we're not allowed to consider Objective-C pointer conversions,
6747 // we're done.
6748 if (!AllowObjCPointerConversion)
6749 return false;
6750
6751 // Is this an Objective-C pointer conversion?
6752 bool IncompatibleObjC = false;
6753 QualType ConvertedType;
6754 return S.isObjCPointerConversion(ConvType, ToNonRefType, ConvertedType,
6755 IncompatibleObjC);
6756}
6757
6758/// AddConversionCandidate - Add a C++ conversion function as a
6759/// candidate in the candidate set (C++ [over.match.conv],
6760/// C++ [over.match.copy]). From is the expression we're converting from,
6761/// and ToType is the type that we're eventually trying to convert to
6762/// (which may or may not be the same type as the type that the
6763/// conversion function produces).
6764void
6765Sema::AddConversionCandidate(CXXConversionDecl *Conversion,
6766 DeclAccessPair FoundDecl,
6767 CXXRecordDecl *ActingContext,
6768 Expr *From, QualType ToType,
6769 OverloadCandidateSet& CandidateSet,
6770 bool AllowObjCConversionOnExplicit) {
6771 assert(!Conversion->getDescribedFunctionTemplate() &&((!Conversion->getDescribedFunctionTemplate() && "Conversion function templates use AddTemplateConversionCandidate"
) ? static_cast<void> (0) : __assert_fail ("!Conversion->getDescribedFunctionTemplate() && \"Conversion function templates use AddTemplateConversionCandidate\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303373/tools/clang/lib/Sema/SemaOverload.cpp"
, 6772, __PRETTY_FUNCTION__))
6772 "Conversion function templates use AddTemplateConversionCandidate")((!Conversion->getDescribedFunctionTemplate() && "Conversion function templates use AddTemplateConversionCandidate"
) ? static_cast<void> (0) : __assert_fail ("!Conversion->getDescribedFunctionTemplate() && \"Conversion function templates use AddTemplateConversionCandidate\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303373/tools/clang/lib/Sema/SemaOverload.cpp"
, 6772, __PRETTY_FUNCTION__))
;
6773 QualType ConvType = Conversion->getConversionType().getNonReferenceType();
6774 if (!CandidateSet.isNewCandidate(Conversion))
6775 return;
6776
6777 // If the conversion function has an undeduced return type, trigger its
6778 // deduction now.
6779 if (getLangOpts().CPlusPlus14 && ConvType->isUndeducedType()) {
6780 if (DeduceReturnType(Conversion, From->getExprLoc()))
6781 return;
6782 ConvType = Conversion->getConversionType().getNonReferenceType();
6783 }
6784
6785 // Per C++ [over.match.conv]p1, [over.match.ref]p1, an explicit conversion
6786 // operator is only a candidate if its return type is the target type or
6787 // can be converted to the target type with a qualification conversion.
6788 if (Conversion->isExplicit() &&
6789 !isAllowableExplicitConversion(*this, ConvType, ToType,
6790 AllowObjCConversionOnExplicit))
6791 return;
6792
6793 // Overload resolution is always an unevaluated context.
6794 EnterExpressionEvaluationContext Unevaluated(
6795 *this, Sema::ExpressionEvaluationContext::Unevaluated);
6796
6797 // Add this candidate
6798 OverloadCandidate &Candidate = CandidateSet.addCandidate(1);
6799 Candidate.FoundDecl = FoundDecl;
6800 Candidate.Function = Conversion;
6801 Candidate.IsSurrogate = false;
6802 Candidate.IgnoreObjectArgument = false;
6803 Candidate.FinalConversion.setAsIdentityConversion();
6804 Candidate.FinalConversion.setFromType(ConvType);
6805 Candidate.FinalConversion.setAllToTypes(ToType);
6806 Candidate.Viable = true;
6807 Candidate.ExplicitCallArguments = 1;
6808
6809 // C++ [over.match.funcs]p4:
6810 // For conversion functions, the function is considered to be a member of
6811 // the class of the implicit implied object argument for the purpose of
6812 // defining the type of the implicit object parameter.
6813 //
6814 // Determine the implicit conversion sequence for the implicit
6815 // object parameter.
6816 QualType ImplicitParamType = From->getType();
6817 if (const PointerType *FromPtrType = ImplicitParamType->getAs<PointerType>())
6818 ImplicitParamType = FromPtrType->getPointeeType();
6819 CXXRecordDecl *ConversionContext
6820 = cast<CXXRecordDecl>(ImplicitParamType->getAs<RecordType>()->getDecl());
6821
6822 Candidate.Conversions[0] = TryObjectArgumentInitialization(
6823 *this, CandidateSet.getLocation(), From->getType(),
6824 From->Classify(Context), Conversion, ConversionContext);
6825
6826 if (Candidate.Conversions[0].isBad()) {
6827 Candidate.Viable = false;
6828 Candidate.FailureKind = ovl_fail_bad_conversion;
6829 return;
6830 }
6831
6832 // We won't go through a user-defined type conversion function to convert a
6833 // derived to base as such conversions are given Conversion Rank. They only
6834 // go through a copy constructor. 13.3.3.1.2-p4 [over.ics.user]
6835 QualType FromCanon
6836 = Context.getCanonicalType(From->getType().getUnqualifiedType());
6837 QualType ToCanon = Context.getCanonicalType(ToType).getUnqualifiedType();
6838 if (FromCanon == ToCanon ||
6839 IsDerivedFrom(CandidateSet.getLocation(), FromCanon, ToCanon)) {
6840 Candidate.Viable = false;
6841 Candidate.FailureKind = ovl_fail_trivial_conversion;
6842 return;
6843 }
6844
6845 // To determine what the conversion from the result of calling the
6846 // conversion function to the type we're eventually trying to
6847 // convert to (ToType), we need to synthesize a call to the
6848 // conversion function and attempt copy initialization from it. This
6849 // makes sure that we get the right semantics with respect to
6850 // lvalues/rvalues and the type. Fortunately, we can allocate this
6851 // call on the stack and we don't need its arguments to be
6852 // well-formed.
6853 DeclRefExpr ConversionRef(Conversion, false, Conversion->getType(),
6854 VK_LValue, From->getLocStart());
6855 ImplicitCastExpr ConversionFn(ImplicitCastExpr::OnStack,
6856 Context.getPointerType(Conversion->getType()),
6857 CK_FunctionToPointerDecay,
6858 &ConversionRef, VK_RValue);
6859
6860 QualType ConversionType = Conversion->getConversionType();
6861 if (!isCompleteType(From->getLocStart(), ConversionType)) {
6862 Candidate.Viable = false;
6863 Candidate.FailureKind = ovl_fail_bad_final_conversion;
6864 return;
6865 }
6866
6867 ExprValueKind VK = Expr::getValueKindForType(ConversionType);
6868
6869 // Note that it is safe to allocate CallExpr on the stack here because
6870 // there are 0 arguments (i.e., nothing is allocated using ASTContext's
6871 // allocator).
6872 QualType CallResultType = ConversionType.getNonLValueExprType(Context);
6873 CallExpr Call(Context, &ConversionFn, None, CallResultType, VK,
6874 From->getLocStart());
6875 ImplicitConversionSequence ICS =
6876 TryCopyInitialization(*this, &Call, ToType,
6877 /*SuppressUserConversions=*/true,
6878 /*InOverloadResolution=*/false,
6879 /*AllowObjCWritebackConversion=*/false);
6880
6881 switch (ICS.getKind()) {
6882 case ImplicitConversionSequence::StandardConversion:
6883 Candidate.FinalConversion = ICS.Standard;
6884
6885 // C++ [over.ics.user]p3:
6886 // If the user-defined conversion is specified by a specialization of a
6887 // conversion function template, the second standard conversion sequence
6888 // shall have exact match rank.
6889 if (Conversion->getPrimaryTemplate() &&
6890 GetConversionRank(ICS.Standard.Second) != ICR_Exact_Match) {
6891 Candidate.Viable = false;
6892 Candidate.FailureKind = ovl_fail_final_conversion_not_exact;
6893 return;
6894 }
6895
6896 // C++0x [dcl.init.ref]p5:
6897 // In the second case, if the reference is an rvalue reference and
6898 // the second standard conversion sequence of the user-defined
6899 // conversion sequence includes an lvalue-to-rvalue conversion, the
6900 // program is ill-formed.
6901 if (ToType->isRValueReferenceType() &&
6902 ICS.Standard.First == ICK_Lvalue_To_Rvalue) {
6903 Candidate.Viable = false;
6904 Candidate.FailureKind = ovl_fail_bad_final_conversion;
6905 return;
6906 }
6907 break;
6908
6909 case ImplicitConversionSequence::BadConversion:
6910 Candidate.Viable = false;
6911 Candidate.FailureKind = ovl_fail_bad_final_conversion;
6912 return;
6913
6914 default:
6915 llvm_unreachable(::llvm::llvm_unreachable_internal("Can only end up with a standard conversion sequence or failure"
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303373/tools/clang/lib/Sema/SemaOverload.cpp"
, 6916)
6916 "Can only end up with a standard conversion sequence or failure")::llvm::llvm_unreachable_internal("Can only end up with a standard conversion sequence or failure"
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303373/tools/clang/lib/Sema/SemaOverload.cpp"
, 6916)
;
6917 }
6918
6919 if (EnableIfAttr *FailedAttr = CheckEnableIf(Conversion, None)) {
6920 Candidate.Viable = false;
6921 Candidate.FailureKind = ovl_fail_enable_if;
6922 Candidate.DeductionFailure.Data = FailedAttr;
6923 return;
6924 }
6925}
6926
6927/// \brief Adds a conversion function template specialization
6928/// candidate to the overload set, using template argument deduction
6929/// to deduce the template arguments of the conversion function
6930/// template from the type that we are converting to (C++
6931/// [temp.deduct.conv]).
6932void
6933Sema::AddTemplateConversionCandidate(FunctionTemplateDecl *FunctionTemplate,
6934 DeclAccessPair FoundDecl,
6935 CXXRecordDecl *ActingDC,
6936 Expr *From, QualType ToType,
6937 OverloadCandidateSet &CandidateSet,
6938 bool AllowObjCConversionOnExplicit) {
6939 assert(isa<CXXConversionDecl>(FunctionTemplate->getTemplatedDecl()) &&((isa<CXXConversionDecl>(FunctionTemplate->getTemplatedDecl
()) && "Only conversion function templates permitted here"
) ? static_cast<void> (0) : __assert_fail ("isa<CXXConversionDecl>(FunctionTemplate->getTemplatedDecl()) && \"Only conversion function templates permitted here\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303373/tools/clang/lib/Sema/SemaOverload.cpp"
, 6940, __PRETTY_FUNCTION__))
6940 "Only conversion function templates permitted here")((isa<CXXConversionDecl>(FunctionTemplate->getTemplatedDecl
()) && "Only conversion function templates permitted here"
) ? static_cast<void> (0) : __assert_fail ("isa<CXXConversionDecl>(FunctionTemplate->getTemplatedDecl()) && \"Only conversion function templates permitted here\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303373/tools/clang/lib/Sema/SemaOverload.cpp"
, 6940, __PRETTY_FUNCTION__))
;
6941
6942 if (!CandidateSet.isNewCandidate(FunctionTemplate))
6943 return;
6944
6945 TemplateDeductionInfo Info(CandidateSet.getLocation());
6946 CXXConversionDecl *Specialization = nullptr;
6947 if (TemplateDeductionResult Result
6948 = DeduceTemplateArguments(FunctionTemplate, ToType,
6949 Specialization, Info)) {
6950 OverloadCandidate &Candidate = CandidateSet.addCandidate();
6951 Candidate.FoundDecl = FoundDecl;
6952 Candidate.Function = FunctionTemplate->getTemplatedDecl();
6953 Candidate.Viable = false;
6954 Candidate.FailureKind = ovl_fail_bad_deduction;
6955 Candidate.IsSurrogate = false;
6956 Candidate.IgnoreObjectArgument = false;
6957 Candidate.ExplicitCallArguments = 1;
6958 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result,
6959 Info);
6960 return;
6961 }
6962
6963 // Add the conversion function template specialization produced by
6964 // template argument deduction as a candidate.
6965 assert(Specialization && "Missing function template specialization?")((Specialization && "Missing function template specialization?"
) ? static_cast<void> (0) : __assert_fail ("Specialization && \"Missing function template specialization?\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303373/tools/clang/lib/Sema/SemaOverload.cpp"
, 6965, __PRETTY_FUNCTION__))
;
6966 AddConversionCandidate(Specialization, FoundDecl, ActingDC, From, ToType,
6967 CandidateSet, AllowObjCConversionOnExplicit);
6968}
6969
6970/// AddSurrogateCandidate - Adds a "surrogate" candidate function that
6971/// converts the given @c Object to a function pointer via the
6972/// conversion function @c Conversion, and then attempts to call it
6973/// with the given arguments (C++ [over.call.object]p2-4). Proto is
6974/// the type of function that we'll eventually be calling.
6975void Sema::AddSurrogateCandidate(CXXConversionDecl *Conversion,
6976 DeclAccessPair FoundDecl,
6977 CXXRecordDecl *ActingContext,
6978 const FunctionProtoType *Proto,
6979 Expr *Object,
6980 ArrayRef<Expr *> Args,
6981 OverloadCandidateSet& CandidateSet) {
6982 if (!CandidateSet.isNewCandidate(Conversion))
6983 return;
6984
6985 // Overload resolution is always an unevaluated context.
6986 EnterExpressionEvaluationContext Unevaluated(
6987 *this, Sema::ExpressionEvaluationContext::Unevaluated);
6988
6989 OverloadCandidate &Candidate = CandidateSet.addCandidate(Args.size() + 1);
6990 Candidate.FoundDecl = FoundDecl;
6991 Candidate.Function = nullptr;
6992 Candidate.Surrogate = Conversion;
6993 Candidate.Viable = true;
6994 Candidate.IsSurrogate = true;
6995 Candidate.IgnoreObjectArgument = false;
6996 Candidate.ExplicitCallArguments = Args.size();
6997
6998 // Determine the implicit conversion sequence for the implicit
6999 // object parameter.
7000 ImplicitConversionSequence ObjectInit = TryObjectArgumentInitialization(
7001 *this, CandidateSet.getLocation(), Object->getType(),
7002 Object->Classify(Context), Conversion, ActingContext);
7003 if (ObjectInit.isBad()) {
7004 Candidate.Viable = false;
7005 Candidate.FailureKind = ovl_fail_bad_conversion;
7006 Candidate.Conversions[0] = ObjectInit;
7007 return;
7008 }
7009
7010 // The first conversion is actually a user-defined conversion whose
7011 // first conversion is ObjectInit's standard conversion (which is
7012 // effectively a reference binding). Record it as such.
7013 Candidate.Conversions[0].setUserDefined();
7014 Candidate.Conversions[0].UserDefined.Before = ObjectInit.Standard;
7015 Candidate.Conversions[0].UserDefined.EllipsisConversion = false;
7016 Candidate.Conversions[0].UserDefined.HadMultipleCandidates = false;
7017 Candidate.Conversions[0].UserDefined.ConversionFunction = Conversion;
7018 Candidate.Conversions[0].UserDefined.FoundConversionFunction = FoundDecl;
7019 Candidate.Conversions[0].UserDefined.After
7020 = Candidate.Conversions[0].UserDefined.Before;
7021 Candidate.Conversions[0].UserDefined.After.setAsIdentityConversion();
7022
7023 // Find the
7024 unsigned NumParams = Proto->getNumParams();
7025
7026 // (C++ 13.3.2p2): A candidate function having fewer than m
7027 // parameters is viable only if it has an ellipsis in its parameter
7028 // list (8.3.5).
7029 if (Args.size() > NumParams && !Proto->isVariadic()) {
7030 Candidate.Viable = false;
7031 Candidate.FailureKind = ovl_fail_too_many_arguments;
7032 return;
7033 }
7034
7035 // Function types don't have any default arguments, so just check if
7036 // we have enough arguments.
7037 if (Args.size() < NumParams) {
7038 // Not enough arguments.
7039 Candidate.Viable = false;
7040 Candidate.FailureKind = ovl_fail_too_few_arguments;
7041 return;
7042 }
7043
7044 // Determine the implicit conversion sequences for each of the
7045 // arguments.
7046 for (unsigned ArgIdx = 0, N = Args.size(); ArgIdx != N; ++ArgIdx) {
7047 if (ArgIdx < NumParams) {
7048 // (C++ 13.3.2p3): for F to be a viable function, there shall
7049 // exist for each argument an implicit conversion sequence
7050 // (13.3.3.1) that converts that argument to the corresponding
7051 // parameter of F.
7052 QualType ParamType = Proto->getParamType(ArgIdx);
7053 Candidate.Conversions[ArgIdx + 1]
7054 = TryCopyInitialization(*this, Args[ArgIdx], ParamType,
7055 /*SuppressUserConversions=*/false,
7056 /*InOverloadResolution=*/false,
7057 /*AllowObjCWritebackConversion=*/
7058 getLangOpts().ObjCAutoRefCount);
7059 if (Candidate.Conversions[ArgIdx + 1].isBad()) {
7060 Candidate.Viable = false;
7061 Candidate.FailureKind = ovl_fail_bad_conversion;
7062 return;
7063 }
7064 } else {
7065 // (C++ 13.3.2p2): For the purposes of overload resolution, any
7066 // argument for which there is no corresponding parameter is
7067 // considered to ""match the ellipsis" (C+ 13.3.3.1.3).
7068 Candidate.Conversions[ArgIdx + 1].setEllipsis();
7069 }
7070 }
7071
7072 if (EnableIfAttr *FailedAttr = CheckEnableIf(Conversion, None)) {
7073 Candidate.Viable = false;
7074 Candidate.FailureKind = ovl_fail_enable_if;
7075 Candidate.DeductionFailure.Data = FailedAttr;
7076 return;
7077 }
7078}
7079
7080/// \brief Add overload candidates for overloaded operators that are
7081/// member functions.
7082///
7083/// Add the overloaded operator candidates that are member functions
7084/// for the operator Op that was used in an operator expression such
7085/// as "x Op y". , Args/NumArgs provides the operator arguments, and
7086/// CandidateSet will store the added overload candidates. (C++
7087/// [over.match.oper]).
7088void Sema::AddMemberOperatorCandidates(OverloadedOperatorKind Op,
7089 SourceLocation OpLoc,
7090 ArrayRef<Expr *> Args,
7091 OverloadCandidateSet& CandidateSet,
7092 SourceRange OpRange) {
7093 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op);
7094
7095 // C++ [over.match.oper]p3:
7096 // For a unary operator @ with an operand of a type whose
7097 // cv-unqualified version is T1, and for a binary operator @ with
7098 // a left operand of a type whose cv-unqualified version is T1 and
7099 // a right operand of a type whose cv-unqualified version is T2,
7100 // three sets of candidate functions, designated member
7101 // candidates, non-member candidates and built-in candidates, are
7102 // constructed as follows:
7103 QualType T1 = Args[0]->getType();
7104
7105 // -- If T1 is a complete class type or a class currently being
7106 // defined, the set of member candidates is the result of the
7107 // qualified lookup of T1::operator@ (13.3.1.1.1); otherwise,
7108 // the set of member candidates is empty.
7109 if (const RecordType *T1Rec = T1->getAs<RecordType>()) {
7110 // Complete the type if it can be completed.
7111 if (!isCompleteType(OpLoc, T1) && !T1Rec->isBeingDefined())
7112 return;
7113 // If the type is neither complete nor being defined, bail out now.
7114 if (!T1Rec->getDecl()->getDefinition())
7115 return;
7116
7117 LookupResult Operators(*this, OpName, OpLoc, LookupOrdinaryName);
7118 LookupQualifiedName(Operators, T1Rec->getDecl());
7119 Operators.suppressDiagnostics();
7120
7121 for (LookupResult::iterator Oper = Operators.begin(),
7122 OperEnd = Operators.end();
7123 Oper != OperEnd;
7124 ++Oper)
7125 AddMethodCandidate(Oper.getPair(), Args[0]->getType(),
7126 Args[0]->Classify(Context), Args.slice(1),
7127 CandidateSet, /*SuppressUserConversions=*/false);
7128 }
7129}
7130
7131/// AddBuiltinCandidate - Add a candidate for a built-in
7132/// operator. ResultTy and ParamTys are the result and parameter types
7133/// of the built-in candidate, respectively. Args and NumArgs are the
7134/// arguments being passed to the candidate. IsAssignmentOperator
7135/// should be true when this built-in candidate is an assignment
7136/// operator. NumContextualBoolArguments is the number of arguments
7137/// (at the beginning of the argument list) that will be contextually
7138/// converted to bool.
7139void Sema::AddBuiltinCandidate(QualType ResultTy, QualType *ParamTys,
7140 ArrayRef<Expr *> Args,
7141 OverloadCandidateSet& CandidateSet,
7142 bool IsAssignmentOperator,
7143 unsigned NumContextualBoolArguments) {
7144 // Overload resolution is always an unevaluated context.
7145 EnterExpressionEvaluationContext Unevaluated(
7146 *this, Sema::ExpressionEvaluationContext::Unevaluated);
7147
7148 // Add this candidate
7149 OverloadCandidate &Candidate = CandidateSet.addCandidate(Args.size());
7150 Candidate.FoundDecl = DeclAccessPair::make(nullptr, AS_none);
7151 Candidate.Function = nullptr;
7152 Candidate.IsSurrogate = false;
7153 Candidate.IgnoreObjectArgument = false;
7154 Candidate.BuiltinTypes.ResultTy = ResultTy;
7155 for (unsigned ArgIdx = 0, N = Args.size(); ArgIdx != N; ++ArgIdx)
7156 Candidate.BuiltinTypes.ParamTypes[ArgIdx] = ParamTys[ArgIdx];
7157
7158 // Determine the implicit conversion sequences for each of the
7159 // arguments.
7160 Candidate.Viable = true;
7161 Candidate.ExplicitCallArguments = Args.size();
7162 for (unsigned ArgIdx = 0, N = Args.size(); ArgIdx != N; ++ArgIdx) {
7163 // C++ [over.match.oper]p4:
7164 // For the built-in assignment operators, conversions of the
7165 // left operand are restricted as follows:
7166 // -- no temporaries are introduced to hold the left operand, and
7167 // -- no user-defined conversions are applied to the left
7168 // operand to achieve a type match with the left-most
7169 // parameter of a built-in candidate.
7170 //
7171 // We block these conversions by turning off user-defined
7172 // conversions, since that is the only way that initialization of
7173 // a reference to a non-class type can occur from something that
7174 // is not of the same type.
7175 if (ArgIdx < NumContextualBoolArguments) {
7176 assert(ParamTys[ArgIdx] == Context.BoolTy &&((ParamTys[ArgIdx] == Context.BoolTy && "Contextual conversion to bool requires bool type"
) ? static_cast<void> (0) : __assert_fail ("ParamTys[ArgIdx] == Context.BoolTy && \"Contextual conversion to bool requires bool type\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303373/tools/clang/lib/Sema/SemaOverload.cpp"
, 7177, __PRETTY_FUNCTION__))
7177 "Contextual conversion to bool requires bool type")((ParamTys[ArgIdx] == Context.BoolTy && "Contextual conversion to bool requires bool type"
) ? static_cast<void> (0) : __assert_fail ("ParamTys[ArgIdx] == Context.BoolTy && \"Contextual conversion to bool requires bool type\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303373/tools/clang/lib/Sema/SemaOverload.cpp"
, 7177, __PRETTY_FUNCTION__))
;
7178 Candidate.Conversions[ArgIdx]
7179 = TryContextuallyConvertToBool(*this, Args[ArgIdx]);
7180 } else {
7181 Candidate.Conversions[ArgIdx]
7182 = TryCopyInitialization(*this, Args[ArgIdx], ParamTys[ArgIdx],
7183 ArgIdx == 0 && IsAssignmentOperator,
7184 /*InOverloadResolution=*/false,
7185 /*AllowObjCWritebackConversion=*/
7186 getLangOpts().ObjCAutoRefCount);
7187 }
7188 if (Candidate.Conversions[ArgIdx].isBad()) {
7189 Candidate.Viable = false;
7190 Candidate.FailureKind = ovl_fail_bad_conversion;
7191 break;
7192 }
7193 }
7194}
7195
7196namespace {
7197
7198/// BuiltinCandidateTypeSet - A set of types that will be used for the
7199/// candidate operator functions for built-in operators (C++
7200/// [over.built]). The types are separated into pointer types and
7201/// enumeration types.
7202class BuiltinCandidateTypeSet {
7203 /// TypeSet - A set of types.
7204 typedef llvm::SetVector<QualType, SmallVector<QualType, 8>,
7205 llvm::SmallPtrSet<QualType, 8>> TypeSet;
7206
7207 /// PointerTypes - The set of pointer types that will be used in the
7208 /// built-in candidates.
7209 TypeSet PointerTypes;
7210
7211 /// MemberPointerTypes - The set of member pointer types that will be
7212 /// used in the built-in candidates.
7213 TypeSet MemberPointerTypes;
7214
7215 /// EnumerationTypes - The set of enumeration types that will be
7216 /// used in the built-in candidates.
7217 TypeSet EnumerationTypes;
7218
7219 /// \brief The set of vector types that will be used in the built-in
7220 /// candidates.
7221 TypeSet VectorTypes;
7222
7223 /// \brief A flag indicating non-record types are viable candidates
7224 bool HasNonRecordTypes;
7225
7226 /// \brief A flag indicating whether either arithmetic or enumeration types
7227 /// were present in the candidate set.
7228 bool HasArithmeticOrEnumeralTypes;
7229
7230 /// \brief A flag indicating whether the nullptr type was present in the
7231 /// candidate set.
7232 bool HasNullPtrType;
7233
7234 /// Sema - The semantic analysis instance where we are building the
7235 /// candidate type set.
7236 Sema &SemaRef;
7237
7238 /// Context - The AST context in which we will build the type sets.
7239 ASTContext &Context;
7240
7241 bool AddPointerWithMoreQualifiedTypeVariants(QualType Ty,
7242 const Qualifiers &VisibleQuals);
7243 bool AddMemberPointerWithMoreQualifiedTypeVariants(QualType Ty);
7244
7245public:
7246 /// iterator - Iterates through the types that are part of the set.
7247 typedef TypeSet::iterator iterator;
7248
7249 BuiltinCandidateTypeSet(Sema &SemaRef)
7250 : HasNonRecordTypes(false),
7251 HasArithmeticOrEnumeralTypes(false),
7252 HasNullPtrType(false),
7253 SemaRef(SemaRef),
7254 Context(SemaRef.Context) { }
7255
7256 void AddTypesConvertedFrom(QualType Ty,
7257 SourceLocation Loc,
7258 bool AllowUserConversions,
7259 bool AllowExplicitConversions,
7260 const Qualifiers &VisibleTypeConversionsQuals);
7261
7262 /// pointer_begin - First pointer type found;
7263 iterator pointer_begin() { return PointerTypes.begin(); }
7264
7265 /// pointer_end - Past the last pointer type found;
7266 iterator pointer_end() { return PointerTypes.end(); }
7267
7268 /// member_pointer_begin - First member pointer type found;
7269 iterator member_pointer_begin() { return MemberPointerTypes.begin(); }
7270
7271 /// member_pointer_end - Past the last member pointer type found;
7272 iterator member_pointer_end() { return MemberPointerTypes.end(); }
7273
7274 /// enumeration_begin - First enumeration type found;
7275 iterator enumeration_begin() { return EnumerationTypes.begin(); }
7276
7277 /// enumeration_end - Past the last enumeration type found;
7278 iterator enumeration_end() { return EnumerationTypes.end(); }
7279
7280 iterator vector_begin() { return VectorTypes.begin(); }
7281 iterator vector_end() { return VectorTypes.end(); }
7282
7283 bool hasNonRecordTypes() { return HasNonRecordTypes; }
7284 bool hasArithmeticOrEnumeralTypes() { return HasArithmeticOrEnumeralTypes; }
7285 bool hasNullPtrType() const { return HasNullPtrType; }
7286};
7287
7288} // end anonymous namespace
7289
7290/// AddPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty to
7291/// the set of pointer types along with any more-qualified variants of
7292/// that type. For example, if @p Ty is "int const *", this routine
7293/// will add "int const *", "int const volatile *", "int const
7294/// restrict *", and "int const volatile restrict *" to the set of
7295/// pointer types. Returns true if the add of @p Ty itself succeeded,
7296/// false otherwise.
7297///
7298/// FIXME: what to do about extended qualifiers?
7299bool
7300BuiltinCandidateTypeSet::AddPointerWithMoreQualifiedTypeVariants(QualType Ty,
7301 const Qualifiers &VisibleQuals) {
7302
7303 // Insert this type.
7304 if (!PointerTypes.insert(Ty))
7305 return false;
7306
7307 QualType PointeeTy;
7308 const PointerType *PointerTy = Ty->getAs<PointerType>();
7309 bool buildObjCPtr = false;
7310 if (!PointerTy) {
7311 const ObjCObjectPointerType *PTy = Ty->castAs<ObjCObjectPointerType>();
7312 PointeeTy = PTy->getPointeeType();
7313 buildObjCPtr = true;
7314 } else {
7315 PointeeTy = PointerTy->getPointeeType();
7316 }
7317
7318 // Don't add qualified variants of arrays. For one, they're not allowed
7319 // (the qualifier would sink to the element type), and for another, the
7320 // only overload situation where it matters is subscript or pointer +- int,
7321 // and those shouldn't have qualifier variants anyway.
7322 if (PointeeTy->isArrayType())
7323 return true;
7324
7325 unsigned BaseCVR = PointeeTy.getCVRQualifiers();
7326 bool hasVolatile = VisibleQuals.hasVolatile();
7327 bool hasRestrict = VisibleQuals.hasRestrict();
7328
7329 // Iterate through all strict supersets of BaseCVR.
7330 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) {
7331 if ((CVR | BaseCVR) != CVR) continue;
7332 // Skip over volatile if no volatile found anywhere in the types.
7333 if ((CVR & Qualifiers::Volatile) && !hasVolatile) continue;
7334
7335 // Skip over restrict if no restrict found anywhere in the types, or if
7336 // the type cannot be restrict-qualified.
7337 if ((CVR & Qualifiers::Restrict) &&
7338 (!hasRestrict ||
7339 (!(PointeeTy->isAnyPointerType() || PointeeTy->isReferenceType()))))
7340 continue;
7341
7342 // Build qualified pointee type.
7343 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR);
7344
7345 // Build qualified pointer type.
7346 QualType QPointerTy;
7347 if (!buildObjCPtr)
7348 QPointerTy = Context.getPointerType(QPointeeTy);
7349 else
7350 QPointerTy = Context.getObjCObjectPointerType(QPointeeTy);
7351
7352 // Insert qualified pointer type.
7353 PointerTypes.insert(QPointerTy);
7354 }
7355
7356 return true;
7357}
7358
7359/// AddMemberPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty
7360/// to the set of pointer types along with any more-qualified variants of
7361/// that type. For example, if @p Ty is "int const *", this routine
7362/// will add "int const *", "int const volatile *", "int const
7363/// restrict *", and "int const volatile restrict *" to the set of
7364/// pointer types. Returns true if the add of @p Ty itself succeeded,
7365/// false otherwise.
7366///
7367/// FIXME: what to do about extended qualifiers?
7368bool
7369BuiltinCandidateTypeSet::AddMemberPointerWithMoreQualifiedTypeVariants(
7370 QualType Ty) {
7371 // Insert this type.
7372 if (!MemberPointerTypes.insert(Ty))
7373 return false;
7374
7375 const MemberPointerType *PointerTy = Ty->getAs<MemberPointerType>();
7376 assert(PointerTy && "type was not a member pointer type!")((PointerTy && "type was not a member pointer type!")
? static_cast<void> (0) : __assert_fail ("PointerTy && \"type was not a member pointer type!\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303373/tools/clang/lib/Sema/SemaOverload.cpp"
, 7376, __PRETTY_FUNCTION__))
;
7377
7378 QualType PointeeTy = PointerTy->getPointeeType();
7379 // Don't add qualified variants of arrays. For one, they're not allowed
7380 // (the qualifier would sink to the element type), and for another, the
7381 // only overload situation where it matters is subscript or pointer +- int,
7382 // and those shouldn't have qualifier variants anyway.
7383 if (PointeeTy->isArrayType())
7384 return true;
7385 const Type *ClassTy = PointerTy->getClass();
7386
7387 // Iterate through all strict supersets of the pointee type's CVR
7388 // qualifiers.
7389 unsigned BaseCVR = PointeeTy.getCVRQualifiers();
7390 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) {
7391 if ((CVR | BaseCVR) != CVR) continue;
7392
7393 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR);
7394 MemberPointerTypes.insert(
7395 Context.getMemberPointerType(QPointeeTy, ClassTy));
7396 }
7397
7398 return true;
7399}
7400
7401/// AddTypesConvertedFrom - Add each of the types to which the type @p
7402/// Ty can be implicit converted to the given set of @p Types. We're
7403/// primarily interested in pointer types and enumeration types. We also
7404/// take member pointer types, for the conditional operator.
7405/// AllowUserConversions is true if we should look at the conversion
7406/// functions of a class type, and AllowExplicitConversions if we
7407/// should also include the explicit conversion functions of a class
7408/// type.
7409void
7410BuiltinCandidateTypeSet::AddTypesConvertedFrom(QualType Ty,
7411 SourceLocation Loc,
7412 bool AllowUserConversions,
7413 bool AllowExplicitConversions,
7414 const Qualifiers &VisibleQuals) {
7415 // Only deal with canonical types.
7416 Ty = Context.getCanonicalType(Ty);
7417
7418 // Look through reference types; they aren't part of the type of an
7419 // expression for the purposes of conversions.
7420 if (const ReferenceType *RefTy = Ty->getAs<ReferenceType>())
7421 Ty = RefTy->getPointeeType();
7422
7423 // If we're dealing with an array type, decay to the pointer.
7424 if (Ty->isArrayType())
7425 Ty = SemaRef.Context.getArrayDecayedType(Ty);
7426
7427 // Otherwise, we don't care about qualifiers on the type.
7428 Ty = Ty.getLocalUnqualifiedType();
7429
7430 // Flag if we ever add a non-record type.
7431 const RecordType *TyRec = Ty->getAs<RecordType>();
7432 HasNonRecordTypes = HasNonRecordTypes || !TyRec;
7433
7434 // Flag if we encounter an arithmetic type.
7435 HasArithmeticOrEnumeralTypes =
7436 HasArithmeticOrEnumeralTypes || Ty->isArithmeticType();
7437
7438 if (Ty->isObjCIdType() || Ty->isObjCClassType())
7439 PointerTypes.insert(Ty);
7440 else if (Ty->getAs<PointerType>() || Ty->getAs<ObjCObjectPointerType>()) {
7441 // Insert our type, and its more-qualified variants, into the set
7442 // of types.
7443 if (!AddPointerWithMoreQualifiedTypeVariants(Ty, VisibleQuals))
7444 return;
7445 } else if (Ty->isMemberPointerType()) {
7446 // Member pointers are far easier, since the pointee can't be converted.
7447 if (!AddMemberPointerWithMoreQualifiedTypeVariants(Ty))
7448 return;
7449 } else if (Ty->isEnumeralType()) {
7450 HasArithmeticOrEnumeralTypes = true;
7451 EnumerationTypes.insert(Ty);
7452 } else if (Ty->isVectorType()) {
7453 // We treat vector types as arithmetic types in many contexts as an
7454 // extension.
7455 HasArithmeticOrEnumeralTypes = true;
7456 VectorTypes.insert(Ty);
7457 } else if (Ty->isNullPtrType()) {
7458 HasNullPtrType = true;
7459 } else if (AllowUserConversions && TyRec) {
7460 // No conversion functions in incomplete types.
7461 if (!SemaRef.isCompleteType(Loc, Ty))
7462 return;
7463
7464 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl());
7465 for (NamedDecl *D : ClassDecl->getVisibleConversionFunctions()) {
7466 if (isa<UsingShadowDecl>(D))
7467 D = cast<UsingShadowDecl>(D)->getTargetDecl();
7468
7469 // Skip conversion function templates; they don't tell us anything
7470 // about which builtin types we can convert to.
7471 if (isa<FunctionTemplateDecl>(D))
7472 continue;
7473
7474 CXXConversionDecl *Conv = cast<CXXConversionDecl>(D);
7475 if (AllowExplicitConversions || !Conv->isExplicit()) {
7476 AddTypesConvertedFrom(Conv->getConversionType(), Loc, false, false,
7477 VisibleQuals);
7478 }
7479 }
7480 }
7481}
7482
7483/// \brief Helper function for AddBuiltinOperatorCandidates() that adds
7484/// the volatile- and non-volatile-qualified assignment operators for the
7485/// given type to the candidate set.
7486static void AddBuiltinAssignmentOperatorCandidates(Sema &S,
7487 QualType T,
7488 ArrayRef<Expr *> Args,
7489 OverloadCandidateSet &CandidateSet) {
7490 QualType ParamTypes[2];
7491
7492 // T& operator=(T&, T)
7493 ParamTypes[0] = S.Context.getLValueReferenceType(T);
7494 ParamTypes[1] = T;
7495 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet,
7496 /*IsAssignmentOperator=*/true);
7497
7498 if (!S.Context.getCanonicalType(T).isVolatileQualified()) {
7499 // volatile T& operator=(volatile T&, T)
7500 ParamTypes[0]
7501 = S.Context.getLValueReferenceType(S.Context.getVolatileType(T));
7502 ParamTypes[1] = T;
7503 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet,
7504 /*IsAssignmentOperator=*/true);
7505 }
7506}
7507
7508/// CollectVRQualifiers - This routine returns Volatile/Restrict qualifiers,
7509/// if any, found in visible type conversion functions found in ArgExpr's type.
7510static Qualifiers CollectVRQualifiers(ASTContext &Context, Expr* ArgExpr) {
7511 Qualifiers VRQuals;
7512 const RecordType *TyRec;
7513 if (const MemberPointerType *RHSMPType =
7514 ArgExpr->getType()->getAs<MemberPointerType>())
7515 TyRec = RHSMPType->getClass()->getAs<RecordType>();
7516 else
7517 TyRec = ArgExpr->getType()->getAs<RecordType>();
7518 if (!TyRec) {
7519 // Just to be safe, assume the worst case.
7520 VRQuals.addVolatile();
7521 VRQuals.addRestrict();
7522 return VRQuals;
7523 }
7524
7525 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl());
7526 if (!ClassDecl->hasDefinition())
7527 return VRQuals;
7528
7529 for (NamedDecl *D : ClassDecl->getVisibleConversionFunctions()) {
7530 if (isa<UsingShadowDecl>(D))
7531 D = cast<UsingShadowDecl>(D)->getTargetDecl();
7532 if (CXXConversionDecl *Conv = dyn_cast<CXXConversionDecl>(D)) {
7533 QualType CanTy = Context.getCanonicalType(Conv->getConversionType());
7534 if (const ReferenceType *ResTypeRef = CanTy->getAs<ReferenceType>())
7535 CanTy = ResTypeRef->getPointeeType();
7536 // Need to go down the pointer/mempointer chain and add qualifiers
7537 // as see them.
7538 bool done = false;
7539 while (!done) {
7540 if (CanTy.isRestrictQualified())
7541 VRQuals.addRestrict();
7542 if (const PointerType *ResTypePtr = CanTy->getAs<PointerType>())
7543 CanTy = ResTypePtr->getPointeeType();
7544 else if (const MemberPointerType *ResTypeMPtr =
7545 CanTy->getAs<MemberPointerType>())
7546 CanTy = ResTypeMPtr->getPointeeType();
7547 else
7548 done = true;
7549 if (CanTy.isVolatileQualified())
7550 VRQuals.addVolatile();
7551 if (VRQuals.hasRestrict() && VRQuals.hasVolatile())
7552 return VRQuals;
7553 }
7554 }
7555 }
7556 return VRQuals;
7557}
7558
7559namespace {
7560
7561/// \brief Helper class to manage the addition of builtin operator overload
7562/// candidates. It provides shared state and utility methods used throughout
7563/// the process, as well as a helper method to add each group of builtin
7564/// operator overloads from the standard to a candidate set.
7565class BuiltinOperatorOverloadBuilder {
7566 // Common instance state available to all overload candidate addition methods.
7567 Sema &S;
7568 ArrayRef<Expr *> Args;
7569 Qualifiers VisibleTypeConversionsQuals;
7570 bool HasArithmeticOrEnumeralCandidateType;
7571 SmallVectorImpl<BuiltinCandidateTypeSet> &CandidateTypes;
7572 OverloadCandidateSet &CandidateSet;
7573
7574 // Define some constants used to index and iterate over the arithemetic types
7575 // provided via the getArithmeticType() method below.
7576 // The "promoted arithmetic types" are the arithmetic
7577 // types are that preserved by promotion (C++ [over.built]p2).
7578 static const unsigned FirstIntegralType = 4;
7579 static const unsigned LastIntegralType = 21;
7580 static const unsigned FirstPromotedIntegralType = 4,
7581 LastPromotedIntegralType = 12;
7582 static const unsigned FirstPromotedArithmeticType = 0,
7583 LastPromotedArithmeticType = 12;
7584 static const unsigned NumArithmeticTypes = 21;
7585
7586 /// \brief Get the canonical type for a given arithmetic type index.
7587 CanQualType getArithmeticType(unsigned index) {
7588 assert(index < NumArithmeticTypes)((index < NumArithmeticTypes) ? static_cast<void> (0
) : __assert_fail ("index < NumArithmeticTypes", "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303373/tools/clang/lib/Sema/SemaOverload.cpp"
, 7588, __PRETTY_FUNCTION__))
;
7589 static CanQualType ASTContext::* const
7590 ArithmeticTypes[NumArithmeticTypes] = {
7591 // Start of promoted types.
7592 &ASTContext::FloatTy,
7593 &ASTContext::DoubleTy,
7594 &ASTContext::LongDoubleTy,
7595 &ASTContext::Float128Ty,
7596
7597 // Start of integral types.
7598 &ASTContext::IntTy,
7599 &ASTContext::LongTy,
7600 &ASTContext::LongLongTy,
7601 &ASTContext::Int128Ty,
7602 &ASTContext::UnsignedIntTy,
7603 &ASTContext::UnsignedLongTy,
7604 &ASTContext::UnsignedLongLongTy,
7605 &ASTContext::UnsignedInt128Ty,
7606 // End of promoted types.
7607
7608 &ASTContext::BoolTy,
7609 &ASTContext::CharTy,
7610 &ASTContext::WCharTy,
7611 &ASTContext::Char16Ty,
7612 &ASTContext::Char32Ty,
7613 &ASTContext::SignedCharTy,
7614 &ASTContext::ShortTy,
7615 &ASTContext::UnsignedCharTy,
7616 &ASTContext::UnsignedShortTy,
7617 // End of integral types.
7618 // FIXME: What about complex? What about half?
7619 };
7620 return S.Context.*ArithmeticTypes[index];
7621 }
7622
7623 /// \brief Gets the canonical type resulting from the usual arithemetic
7624 /// converions for the given arithmetic types.
7625 CanQualType getUsualArithmeticConversions(unsigned L, unsigned R) {
7626 // Accelerator table for performing the usual arithmetic conversions.
7627 // The rules are basically:
7628 // - if either is floating-point, use the wider floating-point
7629 // - if same signedness, use the higher rank
7630 // - if same size, use unsigned of the higher rank
7631 // - use the larger type
7632 // These rules, together with the axiom that higher ranks are
7633 // never smaller, are sufficient to precompute all of these results
7634 // *except* when dealing with signed types of higher rank.
7635 // (we could precompute SLL x UI for all known platforms, but it's
7636 // better not to make any assumptions).
7637 // We assume that int128 has a higher rank than long long on all platforms.
7638 enum PromotedType : int8_t {
7639 Dep=-1,
7640 Flt, Dbl, LDbl, SI, SL, SLL, S128, UI, UL, ULL, U128
7641 };
7642 static const PromotedType ConversionsTable[LastPromotedArithmeticType]
7643 [LastPromotedArithmeticType] = {
7644/* Flt*/ { Flt, Dbl, LDbl, Flt, Flt, Flt, Flt, Flt, Flt, Flt, Flt },
7645/* Dbl*/ { Dbl, Dbl, LDbl, Dbl, Dbl, Dbl, Dbl, Dbl, Dbl, Dbl, Dbl },
7646/*LDbl*/ { LDbl, LDbl, LDbl, LDbl, LDbl, LDbl, LDbl, LDbl, LDbl, LDbl, LDbl },
7647/* SI*/ { Flt, Dbl, LDbl, SI, SL, SLL, S128, UI, UL, ULL, U128 },
7648/* SL*/ { Flt, Dbl, LDbl, SL, SL, SLL, S128, Dep, UL, ULL, U128 },
7649/* SLL*/ { Flt, Dbl, LDbl, SLL, SLL, SLL, S128, Dep, Dep, ULL, U128 },
7650/*S128*/ { Flt, Dbl, LDbl, S128, S128, S128, S128, S128, S128, S128, U128 },
7651/* UI*/ { Flt, Dbl, LDbl, UI, Dep, Dep, S128, UI, UL, ULL, U128 },
7652/* UL*/ { Flt, Dbl, LDbl, UL, UL, Dep, S128, UL, UL, ULL, U128 },
7653/* ULL*/ { Flt, Dbl, LDbl, ULL, ULL, ULL, S128, ULL, ULL, ULL, U128 },
7654/*U128*/ { Flt, Dbl, LDbl, U128, U128, U128, U128, U128, U128, U128, U128 },
7655 };
7656
7657 assert(L < LastPromotedArithmeticType)((L < LastPromotedArithmeticType) ? static_cast<void>
(0) : __assert_fail ("L < LastPromotedArithmeticType", "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303373/tools/clang/lib/Sema/SemaOverload.cpp"
, 7657, __PRETTY_FUNCTION__))
;
7658 assert(R < LastPromotedArithmeticType)((R < LastPromotedArithmeticType) ? static_cast<void>
(0) : __assert_fail ("R < LastPromotedArithmeticType", "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303373/tools/clang/lib/Sema/SemaOverload.cpp"
, 7658, __PRETTY_FUNCTION__))
;
7659 int Idx = ConversionsTable[L][R];
7660
7661 // Fast path: the table gives us a concrete answer.
7662 if (Idx != Dep) return getArithmeticType(Idx);
7663
7664 // Slow path: we need to compare widths.
7665 // An invariant is that the signed type has higher rank.
7666 CanQualType LT = getArithmeticType(L),
7667 RT = getArithmeticType(R);
7668 unsigned LW = S.Context.getIntWidth(LT),
7669 RW = S.Context.getIntWidth(RT);
7670
7671 // If they're different widths, use the signed type.
7672 if (LW > RW) return LT;
7673 else if (LW < RW) return RT;
7674
7675 // Otherwise, use the unsigned type of the signed type's rank.
7676 if (L == SL || R == SL) return S.Context.UnsignedLongTy;
7677 assert(L == SLL || R == SLL)((L == SLL || R == SLL) ? static_cast<void> (0) : __assert_fail
("L == SLL || R == SLL", "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303373/tools/clang/lib/Sema/SemaOverload.cpp"
, 7677, __PRETTY_FUNCTION__))
;
7678 return S.Context.UnsignedLongLongTy;
7679 }
7680
7681 /// \brief Helper method to factor out the common pattern of adding overloads
7682 /// for '++' and '--' builtin operators.
7683 void addPlusPlusMinusMinusStyleOverloads(QualType CandidateTy,
7684 bool HasVolatile,
7685 bool HasRestrict) {
7686 QualType ParamTypes[2] = {
7687 S.Context.getLValueReferenceType(CandidateTy),
7688 S.Context.IntTy
7689 };
7690
7691 // Non-volatile version.
7692 if (Args.size() == 1)
7693 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet);
7694 else
7695 S.AddBuiltinCandidate(CandidateTy, ParamTypes, Args, CandidateSet);
7696
7697 // Use a heuristic to reduce number of builtin candidates in the set:
7698 // add volatile version only if there are conversions to a volatile type.
7699 if (HasVolatile) {
7700 ParamTypes[0] =
7701 S.Context.getLValueReferenceType(
7702 S.Context.getVolatileType(CandidateTy));
7703 if (Args.size() == 1)
7704 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet);
7705 else
7706 S.AddBuiltinCandidate(CandidateTy, ParamTypes, Args, CandidateSet);
7707 }
7708
7709 // Add restrict version only if there are conversions to a restrict type
7710 // and our candidate type is a non-restrict-qualified pointer.
7711 if (HasRestrict && CandidateTy->isAnyPointerType() &&
7712 !CandidateTy.isRestrictQualified()) {
7713 ParamTypes[0]
7714 = S.Context.getLValueReferenceType(
7715 S.Context.getCVRQualifiedType(CandidateTy, Qualifiers::Restrict));
7716 if (Args.size() == 1)
7717 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet);
7718 else
7719 S.AddBuiltinCandidate(CandidateTy, ParamTypes, Args, CandidateSet);
7720
7721 if (HasVolatile) {
7722 ParamTypes[0]
7723 = S.Context.getLValueReferenceType(
7724 S.Context.getCVRQualifiedType(CandidateTy,
7725 (Qualifiers::Volatile |
7726 Qualifiers::Restrict)));
7727 if (Args.size() == 1)
7728 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet);
7729 else
7730 S.AddBuiltinCandidate(CandidateTy, ParamTypes, Args, CandidateSet);
7731 }
7732 }
7733
7734 }
7735
7736public:
7737 BuiltinOperatorOverloadBuilder(
7738 Sema &S, ArrayRef<Expr *> Args,
7739 Qualifiers VisibleTypeConversionsQuals,
7740 bool HasArithmeticOrEnumeralCandidateType,
7741 SmallVectorImpl<BuiltinCandidateTypeSet> &CandidateTypes,
7742 OverloadCandidateSet &CandidateSet)
7743 : S(S), Args(Args),
7744 VisibleTypeConversionsQuals(VisibleTypeConversionsQuals),
7745 HasArithmeticOrEnumeralCandidateType(
7746 HasArithmeticOrEnumeralCandidateType),
7747 CandidateTypes(CandidateTypes),
7748 CandidateSet(CandidateSet) {
7749 // Validate some of our static helper constants in debug builds.
7750 assert(getArithmeticType(FirstPromotedIntegralType) == S.Context.IntTy &&((getArithmeticType(FirstPromotedIntegralType) == S.Context.IntTy
&& "Invalid first promoted integral type") ? static_cast
<void> (0) : __assert_fail ("getArithmeticType(FirstPromotedIntegralType) == S.Context.IntTy && \"Invalid first promoted integral type\""
, "/tmp/buildd/llvm-toolchain-snapshot-5.0~svn303373/tools/clang/lib/Sema/SemaOverload.cpp"
, 7751, __PRETTY_FUNCTION__))
7751 "Invalid first promoted integral type")((getArithmeticType(FirstPromotedIntegralType) == S.Context.IntTy
&& "Invalid first promoted integral type") ? static_cast
<void> (0) : __assert_fail ("getArithmeticType(FirstPromotedIntegralType) == S.