Bug Summary

File:tools/clang/lib/Sema/SemaOverload.cpp
Warning:line 9220, column 44
Called C++ object pointer is null

Annotated Source Code

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clang -cc1 -triple x86_64-pc-linux-gnu -analyze -disable-free -disable-llvm-verifier -discard-value-names -main-file-name SemaOverload.cpp -analyzer-store=region -analyzer-opt-analyze-nested-blocks -analyzer-checker=core -analyzer-checker=apiModeling -analyzer-checker=unix -analyzer-checker=deadcode -analyzer-checker=cplusplus -analyzer-checker=security.insecureAPI.UncheckedReturn -analyzer-checker=security.insecureAPI.getpw -analyzer-checker=security.insecureAPI.gets -analyzer-checker=security.insecureAPI.mktemp -analyzer-checker=security.insecureAPI.mkstemp -analyzer-checker=security.insecureAPI.vfork -analyzer-checker=nullability.NullPassedToNonnull -analyzer-checker=nullability.NullReturnedFromNonnull -analyzer-output plist -w -analyzer-config-compatibility-mode=true -mrelocation-model pic -pic-level 2 -mthread-model posix -relaxed-aliasing -fmath-errno -masm-verbose -mconstructor-aliases -munwind-tables -fuse-init-array -target-cpu x86-64 -dwarf-column-info -debugger-tuning=gdb -momit-leaf-frame-pointer -ffunction-sections -fdata-sections -resource-dir /usr/lib/llvm-8/lib/clang/8.0.0 -D CLANG_VENDOR="Debian " -D _DEBUG -D _GNU_SOURCE -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D __STDC_LIMIT_MACROS -I /build/llvm-toolchain-snapshot-8~svn350071/build-llvm/tools/clang/lib/Sema -I /build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/Sema -I /build/llvm-toolchain-snapshot-8~svn350071/tools/clang/include -I /build/llvm-toolchain-snapshot-8~svn350071/build-llvm/tools/clang/include -I /build/llvm-toolchain-snapshot-8~svn350071/build-llvm/include -I /build/llvm-toolchain-snapshot-8~svn350071/include -U NDEBUG -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/c++/6.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/x86_64-linux-gnu/c++/6.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/x86_64-linux-gnu/c++/6.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/c++/6.3.0/backward -internal-isystem /usr/include/clang/8.0.0/include/ -internal-isystem /usr/local/include -internal-isystem /usr/lib/llvm-8/lib/clang/8.0.0/include -internal-externc-isystem /usr/include/x86_64-linux-gnu -internal-externc-isystem /include -internal-externc-isystem /usr/include -O2 -Wno-unused-parameter -Wwrite-strings -Wno-missing-field-initializers -Wno-long-long -Wno-maybe-uninitialized -Wno-comment -std=c++11 -fdeprecated-macro -fdebug-compilation-dir /build/llvm-toolchain-snapshot-8~svn350071/build-llvm/tools/clang/lib/Sema -fdebug-prefix-map=/build/llvm-toolchain-snapshot-8~svn350071=. -ferror-limit 19 -fmessage-length 0 -fvisibility-inlines-hidden -stack-protector 2 -fobjc-runtime=gcc -fno-common -fdiagnostics-show-option -vectorize-loops -vectorize-slp -analyzer-output=html -analyzer-config stable-report-filename=true -o /tmp/scan-build-2018-12-27-042839-1215-1 -x c++ /build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/Sema/SemaOverload.cpp -faddrsig
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 const Expr *Base, 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)
67 DeclRefExpr(S.Context, Fn, false, Fn->getType(), VK_LValue, Loc, LocInfo);
68 if (HadMultipleCandidates)
69 DRE->setHadMultipleCandidates(true);
70
71 S.MarkDeclRefReferenced(DRE, Base);
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()->isMemberPointerType() ||
227 getFromType()->isObjCObjectPointerType() ||
228 getFromType()->isBlockPointerType() ||
229 getFromType()->isNullPtrType() ||
230 First == ICK_Array_To_Pointer || First == ICK_Function_To_Pointer))
231 return true;
232
233 return false;
234}
235
236/// isPointerConversionToVoidPointer - Determines whether this
237/// conversion is a conversion of a pointer to a void pointer. This is
238/// used as part of the ranking of standard conversion sequences (C++
239/// 13.3.3.2p4).
240bool
241StandardConversionSequence::
242isPointerConversionToVoidPointer(ASTContext& Context) const {
243 QualType FromType = getFromType();
244 QualType ToType = getToType(1);
245
246 // Note that FromType has not necessarily been transformed by the
247 // array-to-pointer implicit conversion, so check for its presence
248 // and redo the conversion to get a pointer.
249 if (First == ICK_Array_To_Pointer)
250 FromType = Context.getArrayDecayedType(FromType);
251
252 if (Second == ICK_Pointer_Conversion && FromType->isAnyPointerType())
253 if (const PointerType* ToPtrType = ToType->getAs<PointerType>())
254 return ToPtrType->getPointeeType()->isVoidType();
255
256 return false;
257}
258
259/// Skip any implicit casts which could be either part of a narrowing conversion
260/// or after one in an implicit conversion.
261static const Expr *IgnoreNarrowingConversion(const Expr *Converted) {
262 while (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(Converted)) {
263 switch (ICE->getCastKind()) {
264 case CK_NoOp:
265 case CK_IntegralCast:
266 case CK_IntegralToBoolean:
267 case CK_IntegralToFloating:
268 case CK_BooleanToSignedIntegral:
269 case CK_FloatingToIntegral:
270 case CK_FloatingToBoolean:
271 case CK_FloatingCast:
272 Converted = ICE->getSubExpr();
273 continue;
274
275 default:
276 return Converted;
277 }
278 }
279
280 return Converted;
281}
282
283/// Check if this standard conversion sequence represents a narrowing
284/// conversion, according to C++11 [dcl.init.list]p7.
285///
286/// \param Ctx The AST context.
287/// \param Converted The result of applying this standard conversion sequence.
288/// \param ConstantValue If this is an NK_Constant_Narrowing conversion, the
289/// value of the expression prior to the narrowing conversion.
290/// \param ConstantType If this is an NK_Constant_Narrowing conversion, the
291/// type of the expression prior to the narrowing conversion.
292/// \param IgnoreFloatToIntegralConversion If true type-narrowing conversions
293/// from floating point types to integral types should be ignored.
294NarrowingKind StandardConversionSequence::getNarrowingKind(
295 ASTContext &Ctx, const Expr *Converted, APValue &ConstantValue,
296 QualType &ConstantType, bool IgnoreFloatToIntegralConversion) const {
297 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++\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/Sema/SemaOverload.cpp"
, 297, __PRETTY_FUNCTION__))
;
298
299 // C++11 [dcl.init.list]p7:
300 // A narrowing conversion is an implicit conversion ...
301 QualType FromType = getToType(0);
302 QualType ToType = getToType(1);
303
304 // A conversion to an enumeration type is narrowing if the conversion to
305 // the underlying type is narrowing. This only arises for expressions of
306 // the form 'Enum{init}'.
307 if (auto *ET = ToType->getAs<EnumType>())
308 ToType = ET->getDecl()->getIntegerType();
309
310 switch (Second) {
311 // 'bool' is an integral type; dispatch to the right place to handle it.
312 case ICK_Boolean_Conversion:
313 if (FromType->isRealFloatingType())
314 goto FloatingIntegralConversion;
315 if (FromType->isIntegralOrUnscopedEnumerationType())
316 goto IntegralConversion;
317 // Boolean conversions can be from pointers and pointers to members
318 // [conv.bool], and those aren't considered narrowing conversions.
319 return NK_Not_Narrowing;
320
321 // -- from a floating-point type to an integer type, or
322 //
323 // -- from an integer type or unscoped enumeration type to a floating-point
324 // type, except where the source is a constant expression and the actual
325 // value after conversion will fit into the target type and will produce
326 // the original value when converted back to the original type, or
327 case ICK_Floating_Integral:
328 FloatingIntegralConversion:
329 if (FromType->isRealFloatingType() && ToType->isIntegralType(Ctx)) {
330 return NK_Type_Narrowing;
331 } else if (FromType->isIntegralOrUnscopedEnumerationType() &&
332 ToType->isRealFloatingType()) {
333 if (IgnoreFloatToIntegralConversion)
334 return NK_Not_Narrowing;
335 llvm::APSInt IntConstantValue;
336 const Expr *Initializer = IgnoreNarrowingConversion(Converted);
337 assert(Initializer && "Unknown conversion expression")((Initializer && "Unknown conversion expression") ? static_cast
<void> (0) : __assert_fail ("Initializer && \"Unknown conversion expression\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/Sema/SemaOverload.cpp"
, 337, __PRETTY_FUNCTION__))
;
338
339 // If it's value-dependent, we can't tell whether it's narrowing.
340 if (Initializer->isValueDependent())
341 return NK_Dependent_Narrowing;
342
343 if (Initializer->isIntegerConstantExpr(IntConstantValue, Ctx)) {
344 // Convert the integer to the floating type.
345 llvm::APFloat Result(Ctx.getFloatTypeSemantics(ToType));
346 Result.convertFromAPInt(IntConstantValue, IntConstantValue.isSigned(),
347 llvm::APFloat::rmNearestTiesToEven);
348 // And back.
349 llvm::APSInt ConvertedValue = IntConstantValue;
350 bool ignored;
351 Result.convertToInteger(ConvertedValue,
352 llvm::APFloat::rmTowardZero, &ignored);
353 // If the resulting value is different, this was a narrowing conversion.
354 if (IntConstantValue != ConvertedValue) {
355 ConstantValue = APValue(IntConstantValue);
356 ConstantType = Initializer->getType();
357 return NK_Constant_Narrowing;
358 }
359 } else {
360 // Variables are always narrowings.
361 return NK_Variable_Narrowing;
362 }
363 }
364 return NK_Not_Narrowing;
365
366 // -- from long double to double or float, or from double to float, except
367 // where the source is a constant expression and the actual value after
368 // conversion is within the range of values that can be represented (even
369 // if it cannot be represented exactly), or
370 case ICK_Floating_Conversion:
371 if (FromType->isRealFloatingType() && ToType->isRealFloatingType() &&
372 Ctx.getFloatingTypeOrder(FromType, ToType) == 1) {
373 // FromType is larger than ToType.
374 const Expr *Initializer = IgnoreNarrowingConversion(Converted);
375
376 // If it's value-dependent, we can't tell whether it's narrowing.
377 if (Initializer->isValueDependent())
378 return NK_Dependent_Narrowing;
379
380 if (Initializer->isCXX11ConstantExpr(Ctx, &ConstantValue)) {
381 // Constant!
382 assert(ConstantValue.isFloat())((ConstantValue.isFloat()) ? static_cast<void> (0) : __assert_fail
("ConstantValue.isFloat()", "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/Sema/SemaOverload.cpp"
, 382, __PRETTY_FUNCTION__))
;
383 llvm::APFloat FloatVal = ConstantValue.getFloat();
384 // Convert the source value into the target type.
385 bool ignored;
386 llvm::APFloat::opStatus ConvertStatus = FloatVal.convert(
387 Ctx.getFloatTypeSemantics(ToType),
388 llvm::APFloat::rmNearestTiesToEven, &ignored);
389 // If there was no overflow, the source value is within the range of
390 // values that can be represented.
391 if (ConvertStatus & llvm::APFloat::opOverflow) {
392 ConstantType = Initializer->getType();
393 return NK_Constant_Narrowing;
394 }
395 } else {
396 return NK_Variable_Narrowing;
397 }
398 }
399 return NK_Not_Narrowing;
400
401 // -- from an integer type or unscoped enumeration type to an integer type
402 // that cannot represent all the values of the original type, except where
403 // the source is a constant expression and the actual value after
404 // conversion will fit into the target type and will produce the original
405 // value when converted back to the original type.
406 case ICK_Integral_Conversion:
407 IntegralConversion: {
408 assert(FromType->isIntegralOrUnscopedEnumerationType())((FromType->isIntegralOrUnscopedEnumerationType()) ? static_cast
<void> (0) : __assert_fail ("FromType->isIntegralOrUnscopedEnumerationType()"
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/Sema/SemaOverload.cpp"
, 408, __PRETTY_FUNCTION__))
;
409 assert(ToType->isIntegralOrUnscopedEnumerationType())((ToType->isIntegralOrUnscopedEnumerationType()) ? static_cast
<void> (0) : __assert_fail ("ToType->isIntegralOrUnscopedEnumerationType()"
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/Sema/SemaOverload.cpp"
, 409, __PRETTY_FUNCTION__))
;
410 const bool FromSigned = FromType->isSignedIntegerOrEnumerationType();
411 const unsigned FromWidth = Ctx.getIntWidth(FromType);
412 const bool ToSigned = ToType->isSignedIntegerOrEnumerationType();
413 const unsigned ToWidth = Ctx.getIntWidth(ToType);
414
415 if (FromWidth > ToWidth ||
416 (FromWidth == ToWidth && FromSigned != ToSigned) ||
417 (FromSigned && !ToSigned)) {
418 // Not all values of FromType can be represented in ToType.
419 llvm::APSInt InitializerValue;
420 const Expr *Initializer = IgnoreNarrowingConversion(Converted);
421
422 // If it's value-dependent, we can't tell whether it's narrowing.
423 if (Initializer->isValueDependent())
424 return NK_Dependent_Narrowing;
425
426 if (!Initializer->isIntegerConstantExpr(InitializerValue, Ctx)) {
427 // Such conversions on variables are always narrowing.
428 return NK_Variable_Narrowing;
429 }
430 bool Narrowing = false;
431 if (FromWidth < ToWidth) {
432 // Negative -> unsigned is narrowing. Otherwise, more bits is never
433 // narrowing.
434 if (InitializerValue.isSigned() && InitializerValue.isNegative())
435 Narrowing = true;
436 } else {
437 // Add a bit to the InitializerValue so we don't have to worry about
438 // signed vs. unsigned comparisons.
439 InitializerValue = InitializerValue.extend(
440 InitializerValue.getBitWidth() + 1);
441 // Convert the initializer to and from the target width and signed-ness.
442 llvm::APSInt ConvertedValue = InitializerValue;
443 ConvertedValue = ConvertedValue.trunc(ToWidth);
444 ConvertedValue.setIsSigned(ToSigned);
445 ConvertedValue = ConvertedValue.extend(InitializerValue.getBitWidth());
446 ConvertedValue.setIsSigned(InitializerValue.isSigned());
447 // If the result is different, this was a narrowing conversion.
448 if (ConvertedValue != InitializerValue)
449 Narrowing = true;
450 }
451 if (Narrowing) {
452 ConstantType = Initializer->getType();
453 ConstantValue = APValue(InitializerValue);
454 return NK_Constant_Narrowing;
455 }
456 }
457 return NK_Not_Narrowing;
458 }
459
460 default:
461 // Other kinds of conversions are not narrowings.
462 return NK_Not_Narrowing;
463 }
464}
465
466/// dump - Print this standard conversion sequence to standard
467/// error. Useful for debugging overloading issues.
468LLVM_DUMP_METHOD__attribute__((noinline)) __attribute__((__used__)) void StandardConversionSequence::dump() const {
469 raw_ostream &OS = llvm::errs();
470 bool PrintedSomething = false;
471 if (First != ICK_Identity) {
472 OS << GetImplicitConversionName(First);
473 PrintedSomething = true;
474 }
475
476 if (Second != ICK_Identity) {
477 if (PrintedSomething) {
478 OS << " -> ";
479 }
480 OS << GetImplicitConversionName(Second);
481
482 if (CopyConstructor) {
483 OS << " (by copy constructor)";
484 } else if (DirectBinding) {
485 OS << " (direct reference binding)";
486 } else if (ReferenceBinding) {
487 OS << " (reference binding)";
488 }
489 PrintedSomething = true;
490 }
491
492 if (Third != ICK_Identity) {
493 if (PrintedSomething) {
494 OS << " -> ";
495 }
496 OS << GetImplicitConversionName(Third);
497 PrintedSomething = true;
498 }
499
500 if (!PrintedSomething) {
501 OS << "No conversions required";
502 }
503}
504
505/// dump - Print this user-defined conversion sequence to standard
506/// error. Useful for debugging overloading issues.
507void UserDefinedConversionSequence::dump() const {
508 raw_ostream &OS = llvm::errs();
509 if (Before.First || Before.Second || Before.Third) {
510 Before.dump();
511 OS << " -> ";
512 }
513 if (ConversionFunction)
514 OS << '\'' << *ConversionFunction << '\'';
515 else
516 OS << "aggregate initialization";
517 if (After.First || After.Second || After.Third) {
518 OS << " -> ";
519 After.dump();
520 }
521}
522
523/// dump - Print this implicit conversion sequence to standard
524/// error. Useful for debugging overloading issues.
525void ImplicitConversionSequence::dump() const {
526 raw_ostream &OS = llvm::errs();
527 if (isStdInitializerListElement())
528 OS << "Worst std::initializer_list element conversion: ";
529 switch (ConversionKind) {
530 case StandardConversion:
531 OS << "Standard conversion: ";
532 Standard.dump();
533 break;
534 case UserDefinedConversion:
535 OS << "User-defined conversion: ";
536 UserDefined.dump();
537 break;
538 case EllipsisConversion:
539 OS << "Ellipsis conversion";
540 break;
541 case AmbiguousConversion:
542 OS << "Ambiguous conversion";
543 break;
544 case BadConversion:
545 OS << "Bad conversion";
546 break;
547 }
548
549 OS << "\n";
550}
551
552void AmbiguousConversionSequence::construct() {
553 new (&conversions()) ConversionSet();
554}
555
556void AmbiguousConversionSequence::destruct() {
557 conversions().~ConversionSet();
558}
559
560void
561AmbiguousConversionSequence::copyFrom(const AmbiguousConversionSequence &O) {
562 FromTypePtr = O.FromTypePtr;
563 ToTypePtr = O.ToTypePtr;
564 new (&conversions()) ConversionSet(O.conversions());
565}
566
567namespace {
568 // Structure used by DeductionFailureInfo to store
569 // template argument information.
570 struct DFIArguments {
571 TemplateArgument FirstArg;
572 TemplateArgument SecondArg;
573 };
574 // Structure used by DeductionFailureInfo to store
575 // template parameter and template argument information.
576 struct DFIParamWithArguments : DFIArguments {
577 TemplateParameter Param;
578 };
579 // Structure used by DeductionFailureInfo to store template argument
580 // information and the index of the problematic call argument.
581 struct DFIDeducedMismatchArgs : DFIArguments {
582 TemplateArgumentList *TemplateArgs;
583 unsigned CallArgIndex;
584 };
585}
586
587/// Convert from Sema's representation of template deduction information
588/// to the form used in overload-candidate information.
589DeductionFailureInfo
590clang::MakeDeductionFailureInfo(ASTContext &Context,
591 Sema::TemplateDeductionResult TDK,
592 TemplateDeductionInfo &Info) {
593 DeductionFailureInfo Result;
594 Result.Result = static_cast<unsigned>(TDK);
595 Result.HasDiagnostic = false;
596 switch (TDK) {
597 case Sema::TDK_Invalid:
598 case Sema::TDK_InstantiationDepth:
599 case Sema::TDK_TooManyArguments:
600 case Sema::TDK_TooFewArguments:
601 case Sema::TDK_MiscellaneousDeductionFailure:
602 case Sema::TDK_CUDATargetMismatch:
603 Result.Data = nullptr;
604 break;
605
606 case Sema::TDK_Incomplete:
607 case Sema::TDK_InvalidExplicitArguments:
608 Result.Data = Info.Param.getOpaqueValue();
609 break;
610
611 case Sema::TDK_DeducedMismatch:
612 case Sema::TDK_DeducedMismatchNested: {
613 // FIXME: Should allocate from normal heap so that we can free this later.
614 auto *Saved = new (Context) DFIDeducedMismatchArgs;
615 Saved->FirstArg = Info.FirstArg;
616 Saved->SecondArg = Info.SecondArg;
617 Saved->TemplateArgs = Info.take();
618 Saved->CallArgIndex = Info.CallArgIndex;
619 Result.Data = Saved;
620 break;
621 }
622
623 case Sema::TDK_NonDeducedMismatch: {
624 // FIXME: Should allocate from normal heap so that we can free this later.
625 DFIArguments *Saved = new (Context) DFIArguments;
626 Saved->FirstArg = Info.FirstArg;
627 Saved->SecondArg = Info.SecondArg;
628 Result.Data = Saved;
629 break;
630 }
631
632 case Sema::TDK_IncompletePack:
633 // FIXME: It's slightly wasteful to allocate two TemplateArguments for this.
634 case Sema::TDK_Inconsistent:
635 case Sema::TDK_Underqualified: {
636 // FIXME: Should allocate from normal heap so that we can free this later.
637 DFIParamWithArguments *Saved = new (Context) DFIParamWithArguments;
638 Saved->Param = Info.Param;
639 Saved->FirstArg = Info.FirstArg;
640 Saved->SecondArg = Info.SecondArg;
641 Result.Data = Saved;
642 break;
643 }
644
645 case Sema::TDK_SubstitutionFailure:
646 Result.Data = Info.take();
647 if (Info.hasSFINAEDiagnostic()) {
648 PartialDiagnosticAt *Diag = new (Result.Diagnostic) PartialDiagnosticAt(
649 SourceLocation(), PartialDiagnostic::NullDiagnostic());
650 Info.takeSFINAEDiagnostic(*Diag);
651 Result.HasDiagnostic = true;
652 }
653 break;
654
655 case Sema::TDK_Success:
656 case Sema::TDK_NonDependentConversionFailure:
657 llvm_unreachable("not a deduction failure")::llvm::llvm_unreachable_internal("not a deduction failure", "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/Sema/SemaOverload.cpp"
, 657)
;
658 }
659
660 return Result;
661}
662
663void DeductionFailureInfo::Destroy() {
664 switch (static_cast<Sema::TemplateDeductionResult>(Result)) {
665 case Sema::TDK_Success:
666 case Sema::TDK_Invalid:
667 case Sema::TDK_InstantiationDepth:
668 case Sema::TDK_Incomplete:
669 case Sema::TDK_TooManyArguments:
670 case Sema::TDK_TooFewArguments:
671 case Sema::TDK_InvalidExplicitArguments:
672 case Sema::TDK_CUDATargetMismatch:
673 case Sema::TDK_NonDependentConversionFailure:
674 break;
675
676 case Sema::TDK_IncompletePack:
677 case Sema::TDK_Inconsistent:
678 case Sema::TDK_Underqualified:
679 case Sema::TDK_DeducedMismatch:
680 case Sema::TDK_DeducedMismatchNested:
681 case Sema::TDK_NonDeducedMismatch:
682 // FIXME: Destroy the data?
683 Data = nullptr;
684 break;
685
686 case Sema::TDK_SubstitutionFailure:
687 // FIXME: Destroy the template argument list?
688 Data = nullptr;
689 if (PartialDiagnosticAt *Diag = getSFINAEDiagnostic()) {
690 Diag->~PartialDiagnosticAt();
691 HasDiagnostic = false;
692 }
693 break;
694
695 // Unhandled
696 case Sema::TDK_MiscellaneousDeductionFailure:
697 break;
698 }
699}
700
701PartialDiagnosticAt *DeductionFailureInfo::getSFINAEDiagnostic() {
702 if (HasDiagnostic)
703 return static_cast<PartialDiagnosticAt*>(static_cast<void*>(Diagnostic));
704 return nullptr;
705}
706
707TemplateParameter DeductionFailureInfo::getTemplateParameter() {
708 switch (static_cast<Sema::TemplateDeductionResult>(Result)) {
709 case Sema::TDK_Success:
710 case Sema::TDK_Invalid:
711 case Sema::TDK_InstantiationDepth:
712 case Sema::TDK_TooManyArguments:
713 case Sema::TDK_TooFewArguments:
714 case Sema::TDK_SubstitutionFailure:
715 case Sema::TDK_DeducedMismatch:
716 case Sema::TDK_DeducedMismatchNested:
717 case Sema::TDK_NonDeducedMismatch:
718 case Sema::TDK_CUDATargetMismatch:
719 case Sema::TDK_NonDependentConversionFailure:
720 return TemplateParameter();
721
722 case Sema::TDK_Incomplete:
723 case Sema::TDK_InvalidExplicitArguments:
724 return TemplateParameter::getFromOpaqueValue(Data);
725
726 case Sema::TDK_IncompletePack:
727 case Sema::TDK_Inconsistent:
728 case Sema::TDK_Underqualified:
729 return static_cast<DFIParamWithArguments*>(Data)->Param;
730
731 // Unhandled
732 case Sema::TDK_MiscellaneousDeductionFailure:
733 break;
734 }
735
736 return TemplateParameter();
737}
738
739TemplateArgumentList *DeductionFailureInfo::getTemplateArgumentList() {
740 switch (static_cast<Sema::TemplateDeductionResult>(Result)) {
741 case Sema::TDK_Success:
742 case Sema::TDK_Invalid:
743 case Sema::TDK_InstantiationDepth:
744 case Sema::TDK_TooManyArguments:
745 case Sema::TDK_TooFewArguments:
746 case Sema::TDK_Incomplete:
747 case Sema::TDK_IncompletePack:
748 case Sema::TDK_InvalidExplicitArguments:
749 case Sema::TDK_Inconsistent:
750 case Sema::TDK_Underqualified:
751 case Sema::TDK_NonDeducedMismatch:
752 case Sema::TDK_CUDATargetMismatch:
753 case Sema::TDK_NonDependentConversionFailure:
754 return nullptr;
755
756 case Sema::TDK_DeducedMismatch:
757 case Sema::TDK_DeducedMismatchNested:
758 return static_cast<DFIDeducedMismatchArgs*>(Data)->TemplateArgs;
759
760 case Sema::TDK_SubstitutionFailure:
761 return static_cast<TemplateArgumentList*>(Data);
762
763 // Unhandled
764 case Sema::TDK_MiscellaneousDeductionFailure:
765 break;
766 }
767
768 return nullptr;
769}
770
771const TemplateArgument *DeductionFailureInfo::getFirstArg() {
772 switch (static_cast<Sema::TemplateDeductionResult>(Result)) {
773 case Sema::TDK_Success:
774 case Sema::TDK_Invalid:
775 case Sema::TDK_InstantiationDepth:
776 case Sema::TDK_Incomplete:
777 case Sema::TDK_TooManyArguments:
778 case Sema::TDK_TooFewArguments:
779 case Sema::TDK_InvalidExplicitArguments:
780 case Sema::TDK_SubstitutionFailure:
781 case Sema::TDK_CUDATargetMismatch:
782 case Sema::TDK_NonDependentConversionFailure:
783 return nullptr;
784
785 case Sema::TDK_IncompletePack:
786 case Sema::TDK_Inconsistent:
787 case Sema::TDK_Underqualified:
788 case Sema::TDK_DeducedMismatch:
789 case Sema::TDK_DeducedMismatchNested:
790 case Sema::TDK_NonDeducedMismatch:
791 return &static_cast<DFIArguments*>(Data)->FirstArg;
792
793 // Unhandled
794 case Sema::TDK_MiscellaneousDeductionFailure:
795 break;
796 }
797
798 return nullptr;
799}
800
801const TemplateArgument *DeductionFailureInfo::getSecondArg() {
802 switch (static_cast<Sema::TemplateDeductionResult>(Result)) {
803 case Sema::TDK_Success:
804 case Sema::TDK_Invalid:
805 case Sema::TDK_InstantiationDepth:
806 case Sema::TDK_Incomplete:
807 case Sema::TDK_IncompletePack:
808 case Sema::TDK_TooManyArguments:
809 case Sema::TDK_TooFewArguments:
810 case Sema::TDK_InvalidExplicitArguments:
811 case Sema::TDK_SubstitutionFailure:
812 case Sema::TDK_CUDATargetMismatch:
813 case Sema::TDK_NonDependentConversionFailure:
814 return nullptr;
815
816 case Sema::TDK_Inconsistent:
817 case Sema::TDK_Underqualified:
818 case Sema::TDK_DeducedMismatch:
819 case Sema::TDK_DeducedMismatchNested:
820 case Sema::TDK_NonDeducedMismatch:
821 return &static_cast<DFIArguments*>(Data)->SecondArg;
822
823 // Unhandled
824 case Sema::TDK_MiscellaneousDeductionFailure:
825 break;
826 }
827
828 return nullptr;
829}
830
831llvm::Optional<unsigned> DeductionFailureInfo::getCallArgIndex() {
832 switch (static_cast<Sema::TemplateDeductionResult>(Result)) {
833 case Sema::TDK_DeducedMismatch:
834 case Sema::TDK_DeducedMismatchNested:
835 return static_cast<DFIDeducedMismatchArgs*>(Data)->CallArgIndex;
836
837 default:
838 return llvm::None;
839 }
840}
841
842void OverloadCandidateSet::destroyCandidates() {
843 for (iterator i = begin(), e = end(); i != e; ++i) {
844 for (auto &C : i->Conversions)
845 C.~ImplicitConversionSequence();
846 if (!i->Viable && i->FailureKind == ovl_fail_bad_deduction)
847 i->DeductionFailure.Destroy();
848 }
849}
850
851void OverloadCandidateSet::clear(CandidateSetKind CSK) {
852 destroyCandidates();
853 SlabAllocator.Reset();
854 NumInlineBytesUsed = 0;
855 Candidates.clear();
856 Functions.clear();
857 Kind = CSK;
858}
859
860namespace {
861 class UnbridgedCastsSet {
862 struct Entry {
863 Expr **Addr;
864 Expr *Saved;
865 };
866 SmallVector<Entry, 2> Entries;
867
868 public:
869 void save(Sema &S, Expr *&E) {
870 assert(E->hasPlaceholderType(BuiltinType::ARCUnbridgedCast))((E->hasPlaceholderType(BuiltinType::ARCUnbridgedCast)) ? static_cast
<void> (0) : __assert_fail ("E->hasPlaceholderType(BuiltinType::ARCUnbridgedCast)"
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/Sema/SemaOverload.cpp"
, 870, __PRETTY_FUNCTION__))
;
871 Entry entry = { &E, E };
872 Entries.push_back(entry);
873 E = S.stripARCUnbridgedCast(E);
874 }
875
876 void restore() {
877 for (SmallVectorImpl<Entry>::iterator
878 i = Entries.begin(), e = Entries.end(); i != e; ++i)
879 *i->Addr = i->Saved;
880 }
881 };
882}
883
884/// checkPlaceholderForOverload - Do any interesting placeholder-like
885/// preprocessing on the given expression.
886///
887/// \param unbridgedCasts a collection to which to add unbridged casts;
888/// without this, they will be immediately diagnosed as errors
889///
890/// Return true on unrecoverable error.
891static bool
892checkPlaceholderForOverload(Sema &S, Expr *&E,
893 UnbridgedCastsSet *unbridgedCasts = nullptr) {
894 if (const BuiltinType *placeholder = E->getType()->getAsPlaceholderType()) {
895 // We can't handle overloaded expressions here because overload
896 // resolution might reasonably tweak them.
897 if (placeholder->getKind() == BuiltinType::Overload) return false;
898
899 // If the context potentially accepts unbridged ARC casts, strip
900 // the unbridged cast and add it to the collection for later restoration.
901 if (placeholder->getKind() == BuiltinType::ARCUnbridgedCast &&
902 unbridgedCasts) {
903 unbridgedCasts->save(S, E);
904 return false;
905 }
906
907 // Go ahead and check everything else.
908 ExprResult result = S.CheckPlaceholderExpr(E);
909 if (result.isInvalid())
910 return true;
911
912 E = result.get();
913 return false;
914 }
915
916 // Nothing to do.
917 return false;
918}
919
920/// checkArgPlaceholdersForOverload - Check a set of call operands for
921/// placeholders.
922static bool checkArgPlaceholdersForOverload(Sema &S,
923 MultiExprArg Args,
924 UnbridgedCastsSet &unbridged) {
925 for (unsigned i = 0, e = Args.size(); i != e; ++i)
926 if (checkPlaceholderForOverload(S, Args[i], &unbridged))
927 return true;
928
929 return false;
930}
931
932/// Determine whether the given New declaration is an overload of the
933/// declarations in Old. This routine returns Ovl_Match or Ovl_NonFunction if
934/// New and Old cannot be overloaded, e.g., if New has the same signature as
935/// some function in Old (C++ 1.3.10) or if the Old declarations aren't
936/// functions (or function templates) at all. When it does return Ovl_Match or
937/// Ovl_NonFunction, MatchedDecl will point to the decl that New cannot be
938/// overloaded with. This decl may be a UsingShadowDecl on top of the underlying
939/// declaration.
940///
941/// Example: Given the following input:
942///
943/// void f(int, float); // #1
944/// void f(int, int); // #2
945/// int f(int, int); // #3
946///
947/// When we process #1, there is no previous declaration of "f", so IsOverload
948/// will not be used.
949///
950/// When we process #2, Old contains only the FunctionDecl for #1. By comparing
951/// the parameter types, we see that #1 and #2 are overloaded (since they have
952/// different signatures), so this routine returns Ovl_Overload; MatchedDecl is
953/// unchanged.
954///
955/// When we process #3, Old is an overload set containing #1 and #2. We compare
956/// the signatures of #3 to #1 (they're overloaded, so we do nothing) and then
957/// #3 to #2. Since the signatures of #3 and #2 are identical (return types of
958/// functions are not part of the signature), IsOverload returns Ovl_Match and
959/// MatchedDecl will be set to point to the FunctionDecl for #2.
960///
961/// 'NewIsUsingShadowDecl' indicates that 'New' is being introduced into a class
962/// by a using declaration. The rules for whether to hide shadow declarations
963/// ignore some properties which otherwise figure into a function template's
964/// signature.
965Sema::OverloadKind
966Sema::CheckOverload(Scope *S, FunctionDecl *New, const LookupResult &Old,
967 NamedDecl *&Match, bool NewIsUsingDecl) {
968 for (LookupResult::iterator I = Old.begin(), E = Old.end();
969 I != E; ++I) {
970 NamedDecl *OldD = *I;
971
972 bool OldIsUsingDecl = false;
973 if (isa<UsingShadowDecl>(OldD)) {
974 OldIsUsingDecl = true;
975
976 // We can always introduce two using declarations into the same
977 // context, even if they have identical signatures.
978 if (NewIsUsingDecl) continue;
979
980 OldD = cast<UsingShadowDecl>(OldD)->getTargetDecl();
981 }
982
983 // A using-declaration does not conflict with another declaration
984 // if one of them is hidden.
985 if ((OldIsUsingDecl || NewIsUsingDecl) && !isVisible(*I))
986 continue;
987
988 // If either declaration was introduced by a using declaration,
989 // we'll need to use slightly different rules for matching.
990 // Essentially, these rules are the normal rules, except that
991 // function templates hide function templates with different
992 // return types or template parameter lists.
993 bool UseMemberUsingDeclRules =
994 (OldIsUsingDecl || NewIsUsingDecl) && CurContext->isRecord() &&
995 !New->getFriendObjectKind();
996
997 if (FunctionDecl *OldF = OldD->getAsFunction()) {
998 if (!IsOverload(New, OldF, UseMemberUsingDeclRules)) {
999 if (UseMemberUsingDeclRules && OldIsUsingDecl) {
1000 HideUsingShadowDecl(S, cast<UsingShadowDecl>(*I));
1001 continue;
1002 }
1003
1004 if (!isa<FunctionTemplateDecl>(OldD) &&
1005 !shouldLinkPossiblyHiddenDecl(*I, New))
1006 continue;
1007
1008 Match = *I;
1009 return Ovl_Match;
1010 }
1011
1012 // Builtins that have custom typechecking or have a reference should
1013 // not be overloadable or redeclarable.
1014 if (!getASTContext().canBuiltinBeRedeclared(OldF)) {
1015 Match = *I;
1016 return Ovl_NonFunction;
1017 }
1018 } else if (isa<UsingDecl>(OldD) || isa<UsingPackDecl>(OldD)) {
1019 // We can overload with these, which can show up when doing
1020 // redeclaration checks for UsingDecls.
1021 assert(Old.getLookupKind() == LookupUsingDeclName)((Old.getLookupKind() == LookupUsingDeclName) ? static_cast<
void> (0) : __assert_fail ("Old.getLookupKind() == LookupUsingDeclName"
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/Sema/SemaOverload.cpp"
, 1021, __PRETTY_FUNCTION__))
;
1022 } else if (isa<TagDecl>(OldD)) {
1023 // We can always overload with tags by hiding them.
1024 } else if (auto *UUD = dyn_cast<UnresolvedUsingValueDecl>(OldD)) {
1025 // Optimistically assume that an unresolved using decl will
1026 // overload; if it doesn't, we'll have to diagnose during
1027 // template instantiation.
1028 //
1029 // Exception: if the scope is dependent and this is not a class
1030 // member, the using declaration can only introduce an enumerator.
1031 if (UUD->getQualifier()->isDependent() && !UUD->isCXXClassMember()) {
1032 Match = *I;
1033 return Ovl_NonFunction;
1034 }
1035 } else {
1036 // (C++ 13p1):
1037 // Only function declarations can be overloaded; object and type
1038 // declarations cannot be overloaded.
1039 Match = *I;
1040 return Ovl_NonFunction;
1041 }
1042 }
1043
1044 return Ovl_Overload;
1045}
1046
1047bool Sema::IsOverload(FunctionDecl *New, FunctionDecl *Old,
1048 bool UseMemberUsingDeclRules, bool ConsiderCudaAttrs) {
1049 // C++ [basic.start.main]p2: This function shall not be overloaded.
1050 if (New->isMain())
1051 return false;
1052
1053 // MSVCRT user defined entry points cannot be overloaded.
1054 if (New->isMSVCRTEntryPoint())
1055 return false;
1056
1057 FunctionTemplateDecl *OldTemplate = Old->getDescribedFunctionTemplate();
1058 FunctionTemplateDecl *NewTemplate = New->getDescribedFunctionTemplate();
1059
1060 // C++ [temp.fct]p2:
1061 // A function template can be overloaded with other function templates
1062 // and with normal (non-template) functions.
1063 if ((OldTemplate == nullptr) != (NewTemplate == nullptr))
1064 return true;
1065
1066 // Is the function New an overload of the function Old?
1067 QualType OldQType = Context.getCanonicalType(Old->getType());
1068 QualType NewQType = Context.getCanonicalType(New->getType());
1069
1070 // Compare the signatures (C++ 1.3.10) of the two functions to
1071 // determine whether they are overloads. If we find any mismatch
1072 // in the signature, they are overloads.
1073
1074 // If either of these functions is a K&R-style function (no
1075 // prototype), then we consider them to have matching signatures.
1076 if (isa<FunctionNoProtoType>(OldQType.getTypePtr()) ||
1077 isa<FunctionNoProtoType>(NewQType.getTypePtr()))
1078 return false;
1079
1080 const FunctionProtoType *OldType = cast<FunctionProtoType>(OldQType);
1081 const FunctionProtoType *NewType = cast<FunctionProtoType>(NewQType);
1082
1083 // The signature of a function includes the types of its
1084 // parameters (C++ 1.3.10), which includes the presence or absence
1085 // of the ellipsis; see C++ DR 357).
1086 if (OldQType != NewQType &&
1087 (OldType->getNumParams() != NewType->getNumParams() ||
1088 OldType->isVariadic() != NewType->isVariadic() ||
1089 !FunctionParamTypesAreEqual(OldType, NewType)))
1090 return true;
1091
1092 // C++ [temp.over.link]p4:
1093 // The signature of a function template consists of its function
1094 // signature, its return type and its template parameter list. The names
1095 // of the template parameters are significant only for establishing the
1096 // relationship between the template parameters and the rest of the
1097 // signature.
1098 //
1099 // We check the return type and template parameter lists for function
1100 // templates first; the remaining checks follow.
1101 //
1102 // However, we don't consider either of these when deciding whether
1103 // a member introduced by a shadow declaration is hidden.
1104 if (!UseMemberUsingDeclRules && NewTemplate &&
1105 (!TemplateParameterListsAreEqual(NewTemplate->getTemplateParameters(),
1106 OldTemplate->getTemplateParameters(),
1107 false, TPL_TemplateMatch) ||
1108 !Context.hasSameType(Old->getDeclaredReturnType(),
1109 New->getDeclaredReturnType())))
1110 return true;
1111
1112 // If the function is a class member, its signature includes the
1113 // cv-qualifiers (if any) and ref-qualifier (if any) on the function itself.
1114 //
1115 // As part of this, also check whether one of the member functions
1116 // is static, in which case they are not overloads (C++
1117 // 13.1p2). While not part of the definition of the signature,
1118 // this check is important to determine whether these functions
1119 // can be overloaded.
1120 CXXMethodDecl *OldMethod = dyn_cast<CXXMethodDecl>(Old);
1121 CXXMethodDecl *NewMethod = dyn_cast<CXXMethodDecl>(New);
1122 if (OldMethod && NewMethod &&
1123 !OldMethod->isStatic() && !NewMethod->isStatic()) {
1124 if (OldMethod->getRefQualifier() != NewMethod->getRefQualifier()) {
1125 if (!UseMemberUsingDeclRules &&
1126 (OldMethod->getRefQualifier() == RQ_None ||
1127 NewMethod->getRefQualifier() == RQ_None)) {
1128 // C++0x [over.load]p2:
1129 // - Member function declarations with the same name and the same
1130 // parameter-type-list as well as member function template
1131 // declarations with the same name, the same parameter-type-list, and
1132 // the same template parameter lists cannot be overloaded if any of
1133 // them, but not all, have a ref-qualifier (8.3.5).
1134 Diag(NewMethod->getLocation(), diag::err_ref_qualifier_overload)
1135 << NewMethod->getRefQualifier() << OldMethod->getRefQualifier();
1136 Diag(OldMethod->getLocation(), diag::note_previous_declaration);
1137 }
1138 return true;
1139 }
1140
1141 // We may not have applied the implicit const for a constexpr member
1142 // function yet (because we haven't yet resolved whether this is a static
1143 // or non-static member function). Add it now, on the assumption that this
1144 // is a redeclaration of OldMethod.
1145 // FIXME: OpenCL: Need to consider address spaces
1146 unsigned OldQuals = OldMethod->getTypeQualifiers().getCVRUQualifiers();
1147 unsigned NewQuals = NewMethod->getTypeQualifiers().getCVRUQualifiers();
1148 if (!getLangOpts().CPlusPlus14 && NewMethod->isConstexpr() &&
1149 !isa<CXXConstructorDecl>(NewMethod))
1150 NewQuals |= Qualifiers::Const;
1151
1152 // We do not allow overloading based off of '__restrict'.
1153 OldQuals &= ~Qualifiers::Restrict;
1154 NewQuals &= ~Qualifiers::Restrict;
1155 if (OldQuals != NewQuals)
1156 return true;
1157 }
1158
1159 // Though pass_object_size is placed on parameters and takes an argument, we
1160 // consider it to be a function-level modifier for the sake of function
1161 // identity. Either the function has one or more parameters with
1162 // pass_object_size or it doesn't.
1163 if (functionHasPassObjectSizeParams(New) !=
1164 functionHasPassObjectSizeParams(Old))
1165 return true;
1166
1167 // enable_if attributes are an order-sensitive part of the signature.
1168 for (specific_attr_iterator<EnableIfAttr>
1169 NewI = New->specific_attr_begin<EnableIfAttr>(),
1170 NewE = New->specific_attr_end<EnableIfAttr>(),
1171 OldI = Old->specific_attr_begin<EnableIfAttr>(),
1172 OldE = Old->specific_attr_end<EnableIfAttr>();
1173 NewI != NewE || OldI != OldE; ++NewI, ++OldI) {
1174 if (NewI == NewE || OldI == OldE)
1175 return true;
1176 llvm::FoldingSetNodeID NewID, OldID;
1177 NewI->getCond()->Profile(NewID, Context, true);
1178 OldI->getCond()->Profile(OldID, Context, true);
1179 if (NewID != OldID)
1180 return true;
1181 }
1182
1183 if (getLangOpts().CUDA && ConsiderCudaAttrs) {
1184 // Don't allow overloading of destructors. (In theory we could, but it
1185 // would be a giant change to clang.)
1186 if (isa<CXXDestructorDecl>(New))
1187 return false;
1188
1189 CUDAFunctionTarget NewTarget = IdentifyCUDATarget(New),
1190 OldTarget = IdentifyCUDATarget(Old);
1191 if (NewTarget == CFT_InvalidTarget)
1192 return false;
1193
1194 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.\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/Sema/SemaOverload.cpp"
, 1194, __PRETTY_FUNCTION__))
;
1195
1196 // Allow overloading of functions with same signature and different CUDA
1197 // target attributes.
1198 return NewTarget != OldTarget;
1199 }
1200
1201 // The signatures match; this is not an overload.
1202 return false;
1203}
1204
1205/// Checks availability of the function depending on the current
1206/// function context. Inside an unavailable function, unavailability is ignored.
1207///
1208/// \returns true if \arg FD is unavailable and current context is inside
1209/// an available function, false otherwise.
1210bool Sema::isFunctionConsideredUnavailable(FunctionDecl *FD) {
1211 if (!FD->isUnavailable())
1212 return false;
1213
1214 // Walk up the context of the caller.
1215 Decl *C = cast<Decl>(CurContext);
1216 do {
1217 if (C->isUnavailable())
1218 return false;
1219 } while ((C = cast_or_null<Decl>(C->getDeclContext())));
1220 return true;
1221}
1222
1223/// Tries a user-defined conversion from From to ToType.
1224///
1225/// Produces an implicit conversion sequence for when a standard conversion
1226/// is not an option. See TryImplicitConversion for more information.
1227static ImplicitConversionSequence
1228TryUserDefinedConversion(Sema &S, Expr *From, QualType ToType,
1229 bool SuppressUserConversions,
1230 bool AllowExplicit,
1231 bool InOverloadResolution,
1232 bool CStyle,
1233 bool AllowObjCWritebackConversion,
1234 bool AllowObjCConversionOnExplicit) {
1235 ImplicitConversionSequence ICS;
1236
1237 if (SuppressUserConversions) {
1238 // We're not in the case above, so there is no conversion that
1239 // we can perform.
1240 ICS.setBad(BadConversionSequence::no_conversion, From, ToType);
1241 return ICS;
1242 }
1243
1244 // Attempt user-defined conversion.
1245 OverloadCandidateSet Conversions(From->getExprLoc(),
1246 OverloadCandidateSet::CSK_Normal);
1247 switch (IsUserDefinedConversion(S, From, ToType, ICS.UserDefined,
1248 Conversions, AllowExplicit,
1249 AllowObjCConversionOnExplicit)) {
1250 case OR_Success:
1251 case OR_Deleted:
1252 ICS.setUserDefined();
1253 // C++ [over.ics.user]p4:
1254 // A conversion of an expression of class type to the same class
1255 // type is given Exact Match rank, and a conversion of an
1256 // expression of class type to a base class of that type is
1257 // given Conversion rank, in spite of the fact that a copy
1258 // constructor (i.e., a user-defined conversion function) is
1259 // called for those cases.
1260 if (CXXConstructorDecl *Constructor
1261 = dyn_cast<CXXConstructorDecl>(ICS.UserDefined.ConversionFunction)) {
1262 QualType FromCanon
1263 = S.Context.getCanonicalType(From->getType().getUnqualifiedType());
1264 QualType ToCanon
1265 = S.Context.getCanonicalType(ToType).getUnqualifiedType();
1266 if (Constructor->isCopyConstructor() &&
1267 (FromCanon == ToCanon ||
1268 S.IsDerivedFrom(From->getBeginLoc(), FromCanon, ToCanon))) {
1269 // Turn this into a "standard" conversion sequence, so that it
1270 // gets ranked with standard conversion sequences.
1271 DeclAccessPair Found = ICS.UserDefined.FoundConversionFunction;
1272 ICS.setStandard();
1273 ICS.Standard.setAsIdentityConversion();
1274 ICS.Standard.setFromType(From->getType());
1275 ICS.Standard.setAllToTypes(ToType);
1276 ICS.Standard.CopyConstructor = Constructor;
1277 ICS.Standard.FoundCopyConstructor = Found;
1278 if (ToCanon != FromCanon)
1279 ICS.Standard.Second = ICK_Derived_To_Base;
1280 }
1281 }
1282 break;
1283
1284 case OR_Ambiguous:
1285 ICS.setAmbiguous();
1286 ICS.Ambiguous.setFromType(From->getType());
1287 ICS.Ambiguous.setToType(ToType);
1288 for (OverloadCandidateSet::iterator Cand = Conversions.begin();
1289 Cand != Conversions.end(); ++Cand)
1290 if (Cand->Viable)
1291 ICS.Ambiguous.addConversion(Cand->FoundDecl, Cand->Function);
1292 break;
1293
1294 // Fall through.
1295 case OR_No_Viable_Function:
1296 ICS.setBad(BadConversionSequence::no_conversion, From, ToType);
1297 break;
1298 }
1299
1300 return ICS;
1301}
1302
1303/// TryImplicitConversion - Attempt to perform an implicit conversion
1304/// from the given expression (Expr) to the given type (ToType). This
1305/// function returns an implicit conversion sequence that can be used
1306/// to perform the initialization. Given
1307///
1308/// void f(float f);
1309/// void g(int i) { f(i); }
1310///
1311/// this routine would produce an implicit conversion sequence to
1312/// describe the initialization of f from i, which will be a standard
1313/// conversion sequence containing an lvalue-to-rvalue conversion (C++
1314/// 4.1) followed by a floating-integral conversion (C++ 4.9).
1315//
1316/// Note that this routine only determines how the conversion can be
1317/// performed; it does not actually perform the conversion. As such,
1318/// it will not produce any diagnostics if no conversion is available,
1319/// but will instead return an implicit conversion sequence of kind
1320/// "BadConversion".
1321///
1322/// If @p SuppressUserConversions, then user-defined conversions are
1323/// not permitted.
1324/// If @p AllowExplicit, then explicit user-defined conversions are
1325/// permitted.
1326///
1327/// \param AllowObjCWritebackConversion Whether we allow the Objective-C
1328/// writeback conversion, which allows __autoreleasing id* parameters to
1329/// be initialized with __strong id* or __weak id* arguments.
1330static ImplicitConversionSequence
1331TryImplicitConversion(Sema &S, Expr *From, QualType ToType,
1332 bool SuppressUserConversions,
1333 bool AllowExplicit,
1334 bool InOverloadResolution,
1335 bool CStyle,
1336 bool AllowObjCWritebackConversion,
1337 bool AllowObjCConversionOnExplicit) {
1338 ImplicitConversionSequence ICS;
1339 if (IsStandardConversion(S, From, ToType, InOverloadResolution,
1340 ICS.Standard, CStyle, AllowObjCWritebackConversion)){
1341 ICS.setStandard();
1342 return ICS;
1343 }
1344
1345 if (!S.getLangOpts().CPlusPlus) {
1346 ICS.setBad(BadConversionSequence::no_conversion, From, ToType);
1347 return ICS;
1348 }
1349
1350 // C++ [over.ics.user]p4:
1351 // A conversion of an expression of class type to the same class
1352 // type is given Exact Match rank, and a conversion of an
1353 // expression of class type to a base class of that type is
1354 // given Conversion rank, in spite of the fact that a copy/move
1355 // constructor (i.e., a user-defined conversion function) is
1356 // called for those cases.
1357 QualType FromType = From->getType();
1358 if (ToType->getAs<RecordType>() && FromType->getAs<RecordType>() &&
1359 (S.Context.hasSameUnqualifiedType(FromType, ToType) ||
1360 S.IsDerivedFrom(From->getBeginLoc(), FromType, ToType))) {
1361 ICS.setStandard();
1362 ICS.Standard.setAsIdentityConversion();
1363 ICS.Standard.setFromType(FromType);
1364 ICS.Standard.setAllToTypes(ToType);
1365
1366 // We don't actually check at this point whether there is a valid
1367 // copy/move constructor, since overloading just assumes that it
1368 // exists. When we actually perform initialization, we'll find the
1369 // appropriate constructor to copy the returned object, if needed.
1370 ICS.Standard.CopyConstructor = nullptr;
1371
1372 // Determine whether this is considered a derived-to-base conversion.
1373 if (!S.Context.hasSameUnqualifiedType(FromType, ToType))
1374 ICS.Standard.Second = ICK_Derived_To_Base;
1375
1376 return ICS;
1377 }
1378
1379 return TryUserDefinedConversion(S, From, ToType, SuppressUserConversions,
1380 AllowExplicit, InOverloadResolution, CStyle,
1381 AllowObjCWritebackConversion,
1382 AllowObjCConversionOnExplicit);
1383}
1384
1385ImplicitConversionSequence
1386Sema::TryImplicitConversion(Expr *From, QualType ToType,
1387 bool SuppressUserConversions,
1388 bool AllowExplicit,
1389 bool InOverloadResolution,
1390 bool CStyle,
1391 bool AllowObjCWritebackConversion) {
1392 return ::TryImplicitConversion(*this, From, ToType,
1393 SuppressUserConversions, AllowExplicit,
1394 InOverloadResolution, CStyle,
1395 AllowObjCWritebackConversion,
1396 /*AllowObjCConversionOnExplicit=*/false);
1397}
1398
1399/// PerformImplicitConversion - Perform an implicit conversion of the
1400/// expression From to the type ToType. Returns the
1401/// converted expression. Flavor is the kind of conversion we're
1402/// performing, used in the error message. If @p AllowExplicit,
1403/// explicit user-defined conversions are permitted.
1404ExprResult
1405Sema::PerformImplicitConversion(Expr *From, QualType ToType,
1406 AssignmentAction Action, bool AllowExplicit) {
1407 ImplicitConversionSequence ICS;
1408 return PerformImplicitConversion(From, ToType, Action, AllowExplicit, ICS);
1409}
1410
1411ExprResult
1412Sema::PerformImplicitConversion(Expr *From, QualType ToType,
1413 AssignmentAction Action, bool AllowExplicit,
1414 ImplicitConversionSequence& ICS) {
1415 if (checkPlaceholderForOverload(*this, From))
1416 return ExprError();
1417
1418 // Objective-C ARC: Determine whether we will allow the writeback conversion.
1419 bool AllowObjCWritebackConversion
1420 = getLangOpts().ObjCAutoRefCount &&
1421 (Action == AA_Passing || Action == AA_Sending);
1422 if (getLangOpts().ObjC)
1423 CheckObjCBridgeRelatedConversions(From->getBeginLoc(), ToType,
1424 From->getType(), From);
1425 ICS = ::TryImplicitConversion(*this, From, ToType,
1426 /*SuppressUserConversions=*/false,
1427 AllowExplicit,
1428 /*InOverloadResolution=*/false,
1429 /*CStyle=*/false,
1430 AllowObjCWritebackConversion,
1431 /*AllowObjCConversionOnExplicit=*/false);
1432 return PerformImplicitConversion(From, ToType, ICS, Action);
1433}
1434
1435/// Determine whether the conversion from FromType to ToType is a valid
1436/// conversion that strips "noexcept" or "noreturn" off the nested function
1437/// type.
1438bool Sema::IsFunctionConversion(QualType FromType, QualType ToType,
1439 QualType &ResultTy) {
1440 if (Context.hasSameUnqualifiedType(FromType, ToType))
1441 return false;
1442
1443 // Permit the conversion F(t __attribute__((noreturn))) -> F(t)
1444 // or F(t noexcept) -> F(t)
1445 // where F adds one of the following at most once:
1446 // - a pointer
1447 // - a member pointer
1448 // - a block pointer
1449 // Changes here need matching changes in FindCompositePointerType.
1450 CanQualType CanTo = Context.getCanonicalType(ToType);
1451 CanQualType CanFrom = Context.getCanonicalType(FromType);
1452 Type::TypeClass TyClass = CanTo->getTypeClass();
1453 if (TyClass != CanFrom->getTypeClass()) return false;
1454 if (TyClass != Type::FunctionProto && TyClass != Type::FunctionNoProto) {
1455 if (TyClass == Type::Pointer) {
1456 CanTo = CanTo.getAs<PointerType>()->getPointeeType();
1457 CanFrom = CanFrom.getAs<PointerType>()->getPointeeType();
1458 } else if (TyClass == Type::BlockPointer) {
1459 CanTo = CanTo.getAs<BlockPointerType>()->getPointeeType();
1460 CanFrom = CanFrom.getAs<BlockPointerType>()->getPointeeType();
1461 } else if (TyClass == Type::MemberPointer) {
1462 auto ToMPT = CanTo.getAs<MemberPointerType>();
1463 auto FromMPT = CanFrom.getAs<MemberPointerType>();
1464 // A function pointer conversion cannot change the class of the function.
1465 if (ToMPT->getClass() != FromMPT->getClass())
1466 return false;
1467 CanTo = ToMPT->getPointeeType();
1468 CanFrom = FromMPT->getPointeeType();
1469 } else {
1470 return false;
1471 }
1472
1473 TyClass = CanTo->getTypeClass();
1474 if (TyClass != CanFrom->getTypeClass()) return false;
1475 if (TyClass != Type::FunctionProto && TyClass != Type::FunctionNoProto)
1476 return false;
1477 }
1478
1479 const auto *FromFn = cast<FunctionType>(CanFrom);
1480 FunctionType::ExtInfo FromEInfo = FromFn->getExtInfo();
1481
1482 const auto *ToFn = cast<FunctionType>(CanTo);
1483 FunctionType::ExtInfo ToEInfo = ToFn->getExtInfo();
1484
1485 bool Changed = false;
1486
1487 // Drop 'noreturn' if not present in target type.
1488 if (FromEInfo.getNoReturn() && !ToEInfo.getNoReturn()) {
1489 FromFn = Context.adjustFunctionType(FromFn, FromEInfo.withNoReturn(false));
1490 Changed = true;
1491 }
1492
1493 // Drop 'noexcept' if not present in target type.
1494 if (const auto *FromFPT = dyn_cast<FunctionProtoType>(FromFn)) {
1495 const auto *ToFPT = cast<FunctionProtoType>(ToFn);
1496 if (FromFPT->isNothrow() && !ToFPT->isNothrow()) {
1497 FromFn = cast<FunctionType>(
1498 Context.getFunctionTypeWithExceptionSpec(QualType(FromFPT, 0),
1499 EST_None)
1500 .getTypePtr());
1501 Changed = true;
1502 }
1503
1504 // Convert FromFPT's ExtParameterInfo if necessary. The conversion is valid
1505 // only if the ExtParameterInfo lists of the two function prototypes can be
1506 // merged and the merged list is identical to ToFPT's ExtParameterInfo list.
1507 SmallVector<FunctionProtoType::ExtParameterInfo, 4> NewParamInfos;
1508 bool CanUseToFPT, CanUseFromFPT;
1509 if (Context.mergeExtParameterInfo(ToFPT, FromFPT, CanUseToFPT,
1510 CanUseFromFPT, NewParamInfos) &&
1511 CanUseToFPT && !CanUseFromFPT) {
1512 FunctionProtoType::ExtProtoInfo ExtInfo = FromFPT->getExtProtoInfo();
1513 ExtInfo.ExtParameterInfos =
1514 NewParamInfos.empty() ? nullptr : NewParamInfos.data();
1515 QualType QT = Context.getFunctionType(FromFPT->getReturnType(),
1516 FromFPT->getParamTypes(), ExtInfo);
1517 FromFn = QT->getAs<FunctionType>();
1518 Changed = true;
1519 }
1520 }
1521
1522 if (!Changed)
1523 return false;
1524
1525 assert(QualType(FromFn, 0).isCanonical())((QualType(FromFn, 0).isCanonical()) ? static_cast<void>
(0) : __assert_fail ("QualType(FromFn, 0).isCanonical()", "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/Sema/SemaOverload.cpp"
, 1525, __PRETTY_FUNCTION__))
;
1526 if (QualType(FromFn, 0) != CanTo) return false;
1527
1528 ResultTy = ToType;
1529 return true;
1530}
1531
1532/// Determine whether the conversion from FromType to ToType is a valid
1533/// vector conversion.
1534///
1535/// \param ICK Will be set to the vector conversion kind, if this is a vector
1536/// conversion.
1537static bool IsVectorConversion(Sema &S, QualType FromType,
1538 QualType ToType, ImplicitConversionKind &ICK) {
1539 // We need at least one of these types to be a vector type to have a vector
1540 // conversion.
1541 if (!ToType->isVectorType() && !FromType->isVectorType())
1542 return false;
1543
1544 // Identical types require no conversions.
1545 if (S.Context.hasSameUnqualifiedType(FromType, ToType))
1546 return false;
1547
1548 // There are no conversions between extended vector types, only identity.
1549 if (ToType->isExtVectorType()) {
1550 // There are no conversions between extended vector types other than the
1551 // identity conversion.
1552 if (FromType->isExtVectorType())
1553 return false;
1554
1555 // Vector splat from any arithmetic type to a vector.
1556 if (FromType->isArithmeticType()) {
1557 ICK = ICK_Vector_Splat;
1558 return true;
1559 }
1560 }
1561
1562 // We can perform the conversion between vector types in the following cases:
1563 // 1)vector types are equivalent AltiVec and GCC vector types
1564 // 2)lax vector conversions are permitted and the vector types are of the
1565 // same size
1566 if (ToType->isVectorType() && FromType->isVectorType()) {
1567 if (S.Context.areCompatibleVectorTypes(FromType, ToType) ||
1568 S.isLaxVectorConversion(FromType, ToType)) {
1569 ICK = ICK_Vector_Conversion;
1570 return true;
1571 }
1572 }
1573
1574 return false;
1575}
1576
1577static bool tryAtomicConversion(Sema &S, Expr *From, QualType ToType,
1578 bool InOverloadResolution,
1579 StandardConversionSequence &SCS,
1580 bool CStyle);
1581
1582/// IsStandardConversion - Determines whether there is a standard
1583/// conversion sequence (C++ [conv], C++ [over.ics.scs]) from the
1584/// expression From to the type ToType. Standard conversion sequences
1585/// only consider non-class types; for conversions that involve class
1586/// types, use TryImplicitConversion. If a conversion exists, SCS will
1587/// contain the standard conversion sequence required to perform this
1588/// conversion and this routine will return true. Otherwise, this
1589/// routine will return false and the value of SCS is unspecified.
1590static bool IsStandardConversion(Sema &S, Expr* From, QualType ToType,
1591 bool InOverloadResolution,
1592 StandardConversionSequence &SCS,
1593 bool CStyle,
1594 bool AllowObjCWritebackConversion) {
1595 QualType FromType = From->getType();
1596
1597 // Standard conversions (C++ [conv])
1598 SCS.setAsIdentityConversion();
1599 SCS.IncompatibleObjC = false;
1600 SCS.setFromType(FromType);
1601 SCS.CopyConstructor = nullptr;
1602
1603 // There are no standard conversions for class types in C++, so
1604 // abort early. When overloading in C, however, we do permit them.
1605 if (S.getLangOpts().CPlusPlus &&
1606 (FromType->isRecordType() || ToType->isRecordType()))
1607 return false;
1608
1609 // The first conversion can be an lvalue-to-rvalue conversion,
1610 // array-to-pointer conversion, or function-to-pointer conversion
1611 // (C++ 4p1).
1612
1613 if (FromType == S.Context.OverloadTy) {
1614 DeclAccessPair AccessPair;
1615 if (FunctionDecl *Fn
1616 = S.ResolveAddressOfOverloadedFunction(From, ToType, false,
1617 AccessPair)) {
1618 // We were able to resolve the address of the overloaded function,
1619 // so we can convert to the type of that function.
1620 FromType = Fn->getType();
1621 SCS.setFromType(FromType);
1622
1623 // we can sometimes resolve &foo<int> regardless of ToType, so check
1624 // if the type matches (identity) or we are converting to bool
1625 if (!S.Context.hasSameUnqualifiedType(
1626 S.ExtractUnqualifiedFunctionType(ToType), FromType)) {
1627 QualType resultTy;
1628 // if the function type matches except for [[noreturn]], it's ok
1629 if (!S.IsFunctionConversion(FromType,
1630 S.ExtractUnqualifiedFunctionType(ToType), resultTy))
1631 // otherwise, only a boolean conversion is standard
1632 if (!ToType->isBooleanType())
1633 return false;
1634 }
1635
1636 // Check if the "from" expression is taking the address of an overloaded
1637 // function and recompute the FromType accordingly. Take advantage of the
1638 // fact that non-static member functions *must* have such an address-of
1639 // expression.
1640 CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn);
1641 if (Method && !Method->isStatic()) {
1642 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\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/Sema/SemaOverload.cpp"
, 1643, __PRETTY_FUNCTION__))
1643 "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\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/Sema/SemaOverload.cpp"
, 1643, __PRETTY_FUNCTION__))
;
1644 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\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/Sema/SemaOverload.cpp"
, 1646, __PRETTY_FUNCTION__))
1645 == 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\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/Sema/SemaOverload.cpp"
, 1646, __PRETTY_FUNCTION__))
1646 "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\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/Sema/SemaOverload.cpp"
, 1646, __PRETTY_FUNCTION__))
;
1647 const Type *ClassType
1648 = S.Context.getTypeDeclType(Method->getParent()).getTypePtr();
1649 FromType = S.Context.getMemberPointerType(FromType, ClassType);
1650 } else if (isa<UnaryOperator>(From->IgnoreParens())) {
1651 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\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/Sema/SemaOverload.cpp"
, 1653, __PRETTY_FUNCTION__))
1652 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\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/Sema/SemaOverload.cpp"
, 1653, __PRETTY_FUNCTION__))
1653 "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\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/Sema/SemaOverload.cpp"
, 1653, __PRETTY_FUNCTION__))
;
1654 FromType = S.Context.getPointerType(FromType);
1655 }
1656
1657 // Check that we've computed the proper type after overload resolution.
1658 // FIXME: FixOverloadedFunctionReference has side-effects; we shouldn't
1659 // be calling it from within an NDEBUG block.
1660 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())"
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/Sema/SemaOverload.cpp"
, 1662, __PRETTY_FUNCTION__))
1661 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())"
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/Sema/SemaOverload.cpp"
, 1662, __PRETTY_FUNCTION__))
1662 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())"
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/Sema/SemaOverload.cpp"
, 1662, __PRETTY_FUNCTION__))
;
1663 } else {
1664 return false;
1665 }
1666 }
1667 // Lvalue-to-rvalue conversion (C++11 4.1):
1668 // A glvalue (3.10) of a non-function, non-array type T can
1669 // be converted to a prvalue.
1670 bool argIsLValue = From->isGLValue();
1671 if (argIsLValue &&
1672 !FromType->isFunctionType() && !FromType->isArrayType() &&
1673 S.Context.getCanonicalType(FromType) != S.Context.OverloadTy) {
1674 SCS.First = ICK_Lvalue_To_Rvalue;
1675
1676 // C11 6.3.2.1p2:
1677 // ... if the lvalue has atomic type, the value has the non-atomic version
1678 // of the type of the lvalue ...
1679 if (const AtomicType *Atomic = FromType->getAs<AtomicType>())
1680 FromType = Atomic->getValueType();
1681
1682 // If T is a non-class type, the type of the rvalue is the
1683 // cv-unqualified version of T. Otherwise, the type of the rvalue
1684 // is T (C++ 4.1p1). C++ can't get here with class types; in C, we
1685 // just strip the qualifiers because they don't matter.
1686 FromType = FromType.getUnqualifiedType();
1687 } else if (FromType->isArrayType()) {
1688 // Array-to-pointer conversion (C++ 4.2)
1689 SCS.First = ICK_Array_To_Pointer;
1690
1691 // An lvalue or rvalue of type "array of N T" or "array of unknown
1692 // bound of T" can be converted to an rvalue of type "pointer to
1693 // T" (C++ 4.2p1).
1694 FromType = S.Context.getArrayDecayedType(FromType);
1695
1696 if (S.IsStringLiteralToNonConstPointerConversion(From, ToType)) {
1697 // This conversion is deprecated in C++03 (D.4)
1698 SCS.DeprecatedStringLiteralToCharPtr = true;
1699
1700 // For the purpose of ranking in overload resolution
1701 // (13.3.3.1.1), this conversion is considered an
1702 // array-to-pointer conversion followed by a qualification
1703 // conversion (4.4). (C++ 4.2p2)
1704 SCS.Second = ICK_Identity;
1705 SCS.Third = ICK_Qualification;
1706 SCS.QualificationIncludesObjCLifetime = false;
1707 SCS.setAllToTypes(FromType);
1708 return true;
1709 }
1710 } else if (FromType->isFunctionType() && argIsLValue) {
1711 // Function-to-pointer conversion (C++ 4.3).
1712 SCS.First = ICK_Function_To_Pointer;
1713
1714 if (auto *DRE = dyn_cast<DeclRefExpr>(From->IgnoreParenCasts()))
1715 if (auto *FD = dyn_cast<FunctionDecl>(DRE->getDecl()))
1716 if (!S.checkAddressOfFunctionIsAvailable(FD))
1717 return false;
1718
1719 // An lvalue of function type T can be converted to an rvalue of
1720 // type "pointer to T." The result is a pointer to the
1721 // function. (C++ 4.3p1).
1722 FromType = S.Context.getPointerType(FromType);
1723 } else {
1724 // We don't require any conversions for the first step.
1725 SCS.First = ICK_Identity;
1726 }
1727 SCS.setToType(0, FromType);
1728
1729 // The second conversion can be an integral promotion, floating
1730 // point promotion, integral conversion, floating point conversion,
1731 // floating-integral conversion, pointer conversion,
1732 // pointer-to-member conversion, or boolean conversion (C++ 4p1).
1733 // For overloading in C, this can also be a "compatible-type"
1734 // conversion.
1735 bool IncompatibleObjC = false;
1736 ImplicitConversionKind SecondICK = ICK_Identity;
1737 if (S.Context.hasSameUnqualifiedType(FromType, ToType)) {
1738 // The unqualified versions of the types are the same: there's no
1739 // conversion to do.
1740 SCS.Second = ICK_Identity;
1741 } else if (S.IsIntegralPromotion(From, FromType, ToType)) {
1742 // Integral promotion (C++ 4.5).
1743 SCS.Second = ICK_Integral_Promotion;
1744 FromType = ToType.getUnqualifiedType();
1745 } else if (S.IsFloatingPointPromotion(FromType, ToType)) {
1746 // Floating point promotion (C++ 4.6).
1747 SCS.Second = ICK_Floating_Promotion;
1748 FromType = ToType.getUnqualifiedType();
1749 } else if (S.IsComplexPromotion(FromType, ToType)) {
1750 // Complex promotion (Clang extension)
1751 SCS.Second = ICK_Complex_Promotion;
1752 FromType = ToType.getUnqualifiedType();
1753 } else if (ToType->isBooleanType() &&
1754 (FromType->isArithmeticType() ||
1755 FromType->isAnyPointerType() ||
1756 FromType->isBlockPointerType() ||
1757 FromType->isMemberPointerType() ||
1758 FromType->isNullPtrType())) {
1759 // Boolean conversions (C++ 4.12).
1760 SCS.Second = ICK_Boolean_Conversion;
1761 FromType = S.Context.BoolTy;
1762 } else if (FromType->isIntegralOrUnscopedEnumerationType() &&
1763 ToType->isIntegralType(S.Context)) {
1764 // Integral conversions (C++ 4.7).
1765 SCS.Second = ICK_Integral_Conversion;
1766 FromType = ToType.getUnqualifiedType();
1767 } else if (FromType->isAnyComplexType() && ToType->isAnyComplexType()) {
1768 // Complex conversions (C99 6.3.1.6)
1769 SCS.Second = ICK_Complex_Conversion;
1770 FromType = ToType.getUnqualifiedType();
1771 } else if ((FromType->isAnyComplexType() && ToType->isArithmeticType()) ||
1772 (ToType->isAnyComplexType() && FromType->isArithmeticType())) {
1773 // Complex-real conversions (C99 6.3.1.7)
1774 SCS.Second = ICK_Complex_Real;
1775 FromType = ToType.getUnqualifiedType();
1776 } else if (FromType->isRealFloatingType() && ToType->isRealFloatingType()) {
1777 // FIXME: disable conversions between long double and __float128 if
1778 // their representation is different until there is back end support
1779 // We of course allow this conversion if long double is really double.
1780 if (&S.Context.getFloatTypeSemantics(FromType) !=
1781 &S.Context.getFloatTypeSemantics(ToType)) {
1782 bool Float128AndLongDouble = ((FromType == S.Context.Float128Ty &&
1783 ToType == S.Context.LongDoubleTy) ||
1784 (FromType == S.Context.LongDoubleTy &&
1785 ToType == S.Context.Float128Ty));
1786 if (Float128AndLongDouble &&
1787 (&S.Context.getFloatTypeSemantics(S.Context.LongDoubleTy) ==
1788 &llvm::APFloat::PPCDoubleDouble()))
1789 return false;
1790 }
1791 // Floating point conversions (C++ 4.8).
1792 SCS.Second = ICK_Floating_Conversion;
1793 FromType = ToType.getUnqualifiedType();
1794 } else if ((FromType->isRealFloatingType() &&
1795 ToType->isIntegralType(S.Context)) ||
1796 (FromType->isIntegralOrUnscopedEnumerationType() &&
1797 ToType->isRealFloatingType())) {
1798 // Floating-integral conversions (C++ 4.9).
1799 SCS.Second = ICK_Floating_Integral;
1800 FromType = ToType.getUnqualifiedType();
1801 } else if (S.IsBlockPointerConversion(FromType, ToType, FromType)) {
1802 SCS.Second = ICK_Block_Pointer_Conversion;
1803 } else if (AllowObjCWritebackConversion &&
1804 S.isObjCWritebackConversion(FromType, ToType, FromType)) {
1805 SCS.Second = ICK_Writeback_Conversion;
1806 } else if (S.IsPointerConversion(From, FromType, ToType, InOverloadResolution,
1807 FromType, IncompatibleObjC)) {
1808 // Pointer conversions (C++ 4.10).
1809 SCS.Second = ICK_Pointer_Conversion;
1810 SCS.IncompatibleObjC = IncompatibleObjC;
1811 FromType = FromType.getUnqualifiedType();
1812 } else if (S.IsMemberPointerConversion(From, FromType, ToType,
1813 InOverloadResolution, FromType)) {
1814 // Pointer to member conversions (4.11).
1815 SCS.Second = ICK_Pointer_Member;
1816 } else if (IsVectorConversion(S, FromType, ToType, SecondICK)) {
1817 SCS.Second = SecondICK;
1818 FromType = ToType.getUnqualifiedType();
1819 } else if (!S.getLangOpts().CPlusPlus &&
1820 S.Context.typesAreCompatible(ToType, FromType)) {
1821 // Compatible conversions (Clang extension for C function overloading)
1822 SCS.Second = ICK_Compatible_Conversion;
1823 FromType = ToType.getUnqualifiedType();
1824 } else if (IsTransparentUnionStandardConversion(S, From, ToType,
1825 InOverloadResolution,
1826 SCS, CStyle)) {
1827 SCS.Second = ICK_TransparentUnionConversion;
1828 FromType = ToType;
1829 } else if (tryAtomicConversion(S, From, ToType, InOverloadResolution, SCS,
1830 CStyle)) {
1831 // tryAtomicConversion has updated the standard conversion sequence
1832 // appropriately.
1833 return true;
1834 } else if (ToType->isEventT() &&
1835 From->isIntegerConstantExpr(S.getASTContext()) &&
1836 From->EvaluateKnownConstInt(S.getASTContext()) == 0) {
1837 SCS.Second = ICK_Zero_Event_Conversion;
1838 FromType = ToType;
1839 } else if (ToType->isQueueT() &&
1840 From->isIntegerConstantExpr(S.getASTContext()) &&
1841 (From->EvaluateKnownConstInt(S.getASTContext()) == 0)) {
1842 SCS.Second = ICK_Zero_Queue_Conversion;
1843 FromType = ToType;
1844 } else {
1845 // No second conversion required.
1846 SCS.Second = ICK_Identity;
1847 }
1848 SCS.setToType(1, FromType);
1849
1850 // The third conversion can be a function pointer conversion or a
1851 // qualification conversion (C++ [conv.fctptr], [conv.qual]).
1852 bool ObjCLifetimeConversion;
1853 if (S.IsFunctionConversion(FromType, ToType, FromType)) {
1854 // Function pointer conversions (removing 'noexcept') including removal of
1855 // 'noreturn' (Clang extension).
1856 SCS.Third = ICK_Function_Conversion;
1857 } else if (S.IsQualificationConversion(FromType, ToType, CStyle,
1858 ObjCLifetimeConversion)) {
1859 SCS.Third = ICK_Qualification;
1860 SCS.QualificationIncludesObjCLifetime = ObjCLifetimeConversion;
1861 FromType = ToType;
1862 } else {
1863 // No conversion required
1864 SCS.Third = ICK_Identity;
1865 }
1866
1867 // C++ [over.best.ics]p6:
1868 // [...] Any difference in top-level cv-qualification is
1869 // subsumed by the initialization itself and does not constitute
1870 // a conversion. [...]
1871 QualType CanonFrom = S.Context.getCanonicalType(FromType);
1872 QualType CanonTo = S.Context.getCanonicalType(ToType);
1873 if (CanonFrom.getLocalUnqualifiedType()
1874 == CanonTo.getLocalUnqualifiedType() &&
1875 CanonFrom.getLocalQualifiers() != CanonTo.getLocalQualifiers()) {
1876 FromType = ToType;
1877 CanonFrom = CanonTo;
1878 }
1879
1880 SCS.setToType(2, FromType);
1881
1882 if (CanonFrom == CanonTo)
1883 return true;
1884
1885 // If we have not converted the argument type to the parameter type,
1886 // this is a bad conversion sequence, unless we're resolving an overload in C.
1887 if (S.getLangOpts().CPlusPlus || !InOverloadResolution)
1888 return false;
1889
1890 ExprResult ER = ExprResult{From};
1891 Sema::AssignConvertType Conv =
1892 S.CheckSingleAssignmentConstraints(ToType, ER,
1893 /*Diagnose=*/false,
1894 /*DiagnoseCFAudited=*/false,
1895 /*ConvertRHS=*/false);
1896 ImplicitConversionKind SecondConv;
1897 switch (Conv) {
1898 case Sema::Compatible:
1899 SecondConv = ICK_C_Only_Conversion;
1900 break;
1901 // For our purposes, discarding qualifiers is just as bad as using an
1902 // incompatible pointer. Note that an IncompatiblePointer conversion can drop
1903 // qualifiers, as well.
1904 case Sema::CompatiblePointerDiscardsQualifiers:
1905 case Sema::IncompatiblePointer:
1906 case Sema::IncompatiblePointerSign:
1907 SecondConv = ICK_Incompatible_Pointer_Conversion;
1908 break;
1909 default:
1910 return false;
1911 }
1912
1913 // First can only be an lvalue conversion, so we pretend that this was the
1914 // second conversion. First should already be valid from earlier in the
1915 // function.
1916 SCS.Second = SecondConv;
1917 SCS.setToType(1, ToType);
1918
1919 // Third is Identity, because Second should rank us worse than any other
1920 // conversion. This could also be ICK_Qualification, but it's simpler to just
1921 // lump everything in with the second conversion, and we don't gain anything
1922 // from making this ICK_Qualification.
1923 SCS.Third = ICK_Identity;
1924 SCS.setToType(2, ToType);
1925 return true;
1926}
1927
1928static bool
1929IsTransparentUnionStandardConversion(Sema &S, Expr* From,
1930 QualType &ToType,
1931 bool InOverloadResolution,
1932 StandardConversionSequence &SCS,
1933 bool CStyle) {
1934
1935 const RecordType *UT = ToType->getAsUnionType();
1936 if (!UT || !UT->getDecl()->hasAttr<TransparentUnionAttr>())
1937 return false;
1938 // The field to initialize within the transparent union.
1939 RecordDecl *UD = UT->getDecl();
1940 // It's compatible if the expression matches any of the fields.
1941 for (const auto *it : UD->fields()) {
1942 if (IsStandardConversion(S, From, it->getType(), InOverloadResolution, SCS,
1943 CStyle, /*ObjCWritebackConversion=*/false)) {
1944 ToType = it->getType();
1945 return true;
1946 }
1947 }
1948 return false;
1949}
1950
1951/// IsIntegralPromotion - Determines whether the conversion from the
1952/// expression From (whose potentially-adjusted type is FromType) to
1953/// ToType is an integral promotion (C++ 4.5). If so, returns true and
1954/// sets PromotedType to the promoted type.
1955bool Sema::IsIntegralPromotion(Expr *From, QualType FromType, QualType ToType) {
1956 const BuiltinType *To = ToType->getAs<BuiltinType>();
1957 // All integers are built-in.
1958 if (!To) {
1959 return false;
1960 }
1961
1962 // An rvalue of type char, signed char, unsigned char, short int, or
1963 // unsigned short int can be converted to an rvalue of type int if
1964 // int can represent all the values of the source type; otherwise,
1965 // the source rvalue can be converted to an rvalue of type unsigned
1966 // int (C++ 4.5p1).
1967 if (FromType->isPromotableIntegerType() && !FromType->isBooleanType() &&
1968 !FromType->isEnumeralType()) {
1969 if (// We can promote any signed, promotable integer type to an int
1970 (FromType->isSignedIntegerType() ||
1971 // We can promote any unsigned integer type whose size is
1972 // less than int to an int.
1973 Context.getTypeSize(FromType) < Context.getTypeSize(ToType))) {
1974 return To->getKind() == BuiltinType::Int;
1975 }
1976
1977 return To->getKind() == BuiltinType::UInt;
1978 }
1979
1980 // C++11 [conv.prom]p3:
1981 // A prvalue of an unscoped enumeration type whose underlying type is not
1982 // fixed (7.2) can be converted to an rvalue a prvalue of the first of the
1983 // following types that can represent all the values of the enumeration
1984 // (i.e., the values in the range bmin to bmax as described in 7.2): int,
1985 // unsigned int, long int, unsigned long int, long long int, or unsigned
1986 // long long int. If none of the types in that list can represent all the
1987 // values of the enumeration, an rvalue a prvalue of an unscoped enumeration
1988 // type can be converted to an rvalue a prvalue of the extended integer type
1989 // with lowest integer conversion rank (4.13) greater than the rank of long
1990 // long in which all the values of the enumeration can be represented. If
1991 // there are two such extended types, the signed one is chosen.
1992 // C++11 [conv.prom]p4:
1993 // A prvalue of an unscoped enumeration type whose underlying type is fixed
1994 // can be converted to a prvalue of its underlying type. Moreover, if
1995 // integral promotion can be applied to its underlying type, a prvalue of an
1996 // unscoped enumeration type whose underlying type is fixed can also be
1997 // converted to a prvalue of the promoted underlying type.
1998 if (const EnumType *FromEnumType = FromType->getAs<EnumType>()) {
1999 // C++0x 7.2p9: Note that this implicit enum to int conversion is not
2000 // provided for a scoped enumeration.
2001 if (FromEnumType->getDecl()->isScoped())
2002 return false;
2003
2004 // We can perform an integral promotion to the underlying type of the enum,
2005 // even if that's not the promoted type. Note that the check for promoting
2006 // the underlying type is based on the type alone, and does not consider
2007 // the bitfield-ness of the actual source expression.
2008 if (FromEnumType->getDecl()->isFixed()) {
2009 QualType Underlying = FromEnumType->getDecl()->getIntegerType();
2010 return Context.hasSameUnqualifiedType(Underlying, ToType) ||
2011 IsIntegralPromotion(nullptr, Underlying, ToType);
2012 }
2013
2014 // We have already pre-calculated the promotion type, so this is trivial.
2015 if (ToType->isIntegerType() &&
2016 isCompleteType(From->getBeginLoc(), FromType))
2017 return Context.hasSameUnqualifiedType(
2018 ToType, FromEnumType->getDecl()->getPromotionType());
2019
2020 // C++ [conv.prom]p5:
2021 // If the bit-field has an enumerated type, it is treated as any other
2022 // value of that type for promotion purposes.
2023 //
2024 // ... so do not fall through into the bit-field checks below in C++.
2025 if (getLangOpts().CPlusPlus)
2026 return false;
2027 }
2028
2029 // C++0x [conv.prom]p2:
2030 // A prvalue of type char16_t, char32_t, or wchar_t (3.9.1) can be converted
2031 // to an rvalue a prvalue of the first of the following types that can
2032 // represent all the values of its underlying type: int, unsigned int,
2033 // long int, unsigned long int, long long int, or unsigned long long int.
2034 // If none of the types in that list can represent all the values of its
2035 // underlying type, an rvalue a prvalue of type char16_t, char32_t,
2036 // or wchar_t can be converted to an rvalue a prvalue of its underlying
2037 // type.
2038 if (FromType->isAnyCharacterType() && !FromType->isCharType() &&
2039 ToType->isIntegerType()) {
2040 // Determine whether the type we're converting from is signed or
2041 // unsigned.
2042 bool FromIsSigned = FromType->isSignedIntegerType();
2043 uint64_t FromSize = Context.getTypeSize(FromType);
2044
2045 // The types we'll try to promote to, in the appropriate
2046 // order. Try each of these types.
2047 QualType PromoteTypes[6] = {
2048 Context.IntTy, Context.UnsignedIntTy,
2049 Context.LongTy, Context.UnsignedLongTy ,
2050 Context.LongLongTy, Context.UnsignedLongLongTy
2051 };
2052 for (int Idx = 0; Idx < 6; ++Idx) {
2053 uint64_t ToSize = Context.getTypeSize(PromoteTypes[Idx]);
2054 if (FromSize < ToSize ||
2055 (FromSize == ToSize &&
2056 FromIsSigned == PromoteTypes[Idx]->isSignedIntegerType())) {
2057 // We found the type that we can promote to. If this is the
2058 // type we wanted, we have a promotion. Otherwise, no
2059 // promotion.
2060 return Context.hasSameUnqualifiedType(ToType, PromoteTypes[Idx]);
2061 }
2062 }
2063 }
2064
2065 // An rvalue for an integral bit-field (9.6) can be converted to an
2066 // rvalue of type int if int can represent all the values of the
2067 // bit-field; otherwise, it can be converted to unsigned int if
2068 // unsigned int can represent all the values of the bit-field. If
2069 // the bit-field is larger yet, no integral promotion applies to
2070 // it. If the bit-field has an enumerated type, it is treated as any
2071 // other value of that type for promotion purposes (C++ 4.5p3).
2072 // FIXME: We should delay checking of bit-fields until we actually perform the
2073 // conversion.
2074 //
2075 // FIXME: In C, only bit-fields of types _Bool, int, or unsigned int may be
2076 // promoted, per C11 6.3.1.1/2. We promote all bit-fields (including enum
2077 // bit-fields and those whose underlying type is larger than int) for GCC
2078 // compatibility.
2079 if (From) {
2080 if (FieldDecl *MemberDecl = From->getSourceBitField()) {
2081 llvm::APSInt BitWidth;
2082 if (FromType->isIntegralType(Context) &&
2083 MemberDecl->getBitWidth()->isIntegerConstantExpr(BitWidth, Context)) {
2084 llvm::APSInt ToSize(BitWidth.getBitWidth(), BitWidth.isUnsigned());
2085 ToSize = Context.getTypeSize(ToType);
2086
2087 // Are we promoting to an int from a bitfield that fits in an int?
2088 if (BitWidth < ToSize ||
2089 (FromType->isSignedIntegerType() && BitWidth <= ToSize)) {
2090 return To->getKind() == BuiltinType::Int;
2091 }
2092
2093 // Are we promoting to an unsigned int from an unsigned bitfield
2094 // that fits into an unsigned int?
2095 if (FromType->isUnsignedIntegerType() && BitWidth <= ToSize) {
2096 return To->getKind() == BuiltinType::UInt;
2097 }
2098
2099 return false;
2100 }
2101 }
2102 }
2103
2104 // An rvalue of type bool can be converted to an rvalue of type int,
2105 // with false becoming zero and true becoming one (C++ 4.5p4).
2106 if (FromType->isBooleanType() && To->getKind() == BuiltinType::Int) {
2107 return true;
2108 }
2109
2110 return false;
2111}
2112
2113/// IsFloatingPointPromotion - Determines whether the conversion from
2114/// FromType to ToType is a floating point promotion (C++ 4.6). If so,
2115/// returns true and sets PromotedType to the promoted type.
2116bool Sema::IsFloatingPointPromotion(QualType FromType, QualType ToType) {
2117 if (const BuiltinType *FromBuiltin = FromType->getAs<BuiltinType>())
2118 if (const BuiltinType *ToBuiltin = ToType->getAs<BuiltinType>()) {
2119 /// An rvalue of type float can be converted to an rvalue of type
2120 /// double. (C++ 4.6p1).
2121 if (FromBuiltin->getKind() == BuiltinType::Float &&
2122 ToBuiltin->getKind() == BuiltinType::Double)
2123 return true;
2124
2125 // C99 6.3.1.5p1:
2126 // When a float is promoted to double or long double, or a
2127 // double is promoted to long double [...].
2128 if (!getLangOpts().CPlusPlus &&
2129 (FromBuiltin->getKind() == BuiltinType::Float ||
2130 FromBuiltin->getKind() == BuiltinType::Double) &&
2131 (ToBuiltin->getKind() == BuiltinType::LongDouble ||
2132 ToBuiltin->getKind() == BuiltinType::Float128))
2133 return true;
2134
2135 // Half can be promoted to float.
2136 if (!getLangOpts().NativeHalfType &&
2137 FromBuiltin->getKind() == BuiltinType::Half &&
2138 ToBuiltin->getKind() == BuiltinType::Float)
2139 return true;
2140 }
2141
2142 return false;
2143}
2144
2145/// Determine if a conversion is a complex promotion.
2146///
2147/// A complex promotion is defined as a complex -> complex conversion
2148/// where the conversion between the underlying real types is a
2149/// floating-point or integral promotion.
2150bool Sema::IsComplexPromotion(QualType FromType, QualType ToType) {
2151 const ComplexType *FromComplex = FromType->getAs<ComplexType>();
2152 if (!FromComplex)
2153 return false;
2154
2155 const ComplexType *ToComplex = ToType->getAs<ComplexType>();
2156 if (!ToComplex)
2157 return false;
2158
2159 return IsFloatingPointPromotion(FromComplex->getElementType(),
2160 ToComplex->getElementType()) ||
2161 IsIntegralPromotion(nullptr, FromComplex->getElementType(),
2162 ToComplex->getElementType());
2163}
2164
2165/// BuildSimilarlyQualifiedPointerType - In a pointer conversion from
2166/// the pointer type FromPtr to a pointer to type ToPointee, with the
2167/// same type qualifiers as FromPtr has on its pointee type. ToType,
2168/// if non-empty, will be a pointer to ToType that may or may not have
2169/// the right set of qualifiers on its pointee.
2170///
2171static QualType
2172BuildSimilarlyQualifiedPointerType(const Type *FromPtr,
2173 QualType ToPointee, QualType ToType,
2174 ASTContext &Context,
2175 bool StripObjCLifetime = false) {
2176 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\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/Sema/SemaOverload.cpp"
, 2178, __PRETTY_FUNCTION__))
2177 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\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/Sema/SemaOverload.cpp"
, 2178, __PRETTY_FUNCTION__))
2178 "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\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/Sema/SemaOverload.cpp"
, 2178, __PRETTY_FUNCTION__))
;
2179
2180 /// Conversions to 'id' subsume cv-qualifier conversions.
2181 if (ToType->isObjCIdType() || ToType->isObjCQualifiedIdType())
2182 return ToType.getUnqualifiedType();
2183
2184 QualType CanonFromPointee
2185 = Context.getCanonicalType(FromPtr->getPointeeType());
2186 QualType CanonToPointee = Context.getCanonicalType(ToPointee);
2187 Qualifiers Quals = CanonFromPointee.getQualifiers();
2188
2189 if (StripObjCLifetime)
2190 Quals.removeObjCLifetime();
2191
2192 // Exact qualifier match -> return the pointer type we're converting to.
2193 if (CanonToPointee.getLocalQualifiers() == Quals) {
2194 // ToType is exactly what we need. Return it.
2195 if (!ToType.isNull())
2196 return ToType.getUnqualifiedType();
2197
2198 // Build a pointer to ToPointee. It has the right qualifiers
2199 // already.
2200 if (isa<ObjCObjectPointerType>(ToType))
2201 return Context.getObjCObjectPointerType(ToPointee);
2202 return Context.getPointerType(ToPointee);
2203 }
2204
2205 // Just build a canonical type that has the right qualifiers.
2206 QualType QualifiedCanonToPointee
2207 = Context.getQualifiedType(CanonToPointee.getLocalUnqualifiedType(), Quals);
2208
2209 if (isa<ObjCObjectPointerType>(ToType))
2210 return Context.getObjCObjectPointerType(QualifiedCanonToPointee);
2211 return Context.getPointerType(QualifiedCanonToPointee);
2212}
2213
2214static bool isNullPointerConstantForConversion(Expr *Expr,
2215 bool InOverloadResolution,
2216 ASTContext &Context) {
2217 // Handle value-dependent integral null pointer constants correctly.
2218 // http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#903
2219 if (Expr->isValueDependent() && !Expr->isTypeDependent() &&
2220 Expr->getType()->isIntegerType() && !Expr->getType()->isEnumeralType())
2221 return !InOverloadResolution;
2222
2223 return Expr->isNullPointerConstant(Context,
2224 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull
2225 : Expr::NPC_ValueDependentIsNull);
2226}
2227
2228/// IsPointerConversion - Determines whether the conversion of the
2229/// expression From, which has the (possibly adjusted) type FromType,
2230/// can be converted to the type ToType via a pointer conversion (C++
2231/// 4.10). If so, returns true and places the converted type (that
2232/// might differ from ToType in its cv-qualifiers at some level) into
2233/// ConvertedType.
2234///
2235/// This routine also supports conversions to and from block pointers
2236/// and conversions with Objective-C's 'id', 'id<protocols...>', and
2237/// pointers to interfaces. FIXME: Once we've determined the
2238/// appropriate overloading rules for Objective-C, we may want to
2239/// split the Objective-C checks into a different routine; however,
2240/// GCC seems to consider all of these conversions to be pointer
2241/// conversions, so for now they live here. IncompatibleObjC will be
2242/// set if the conversion is an allowed Objective-C conversion that
2243/// should result in a warning.
2244bool Sema::IsPointerConversion(Expr *From, QualType FromType, QualType ToType,
2245 bool InOverloadResolution,
2246 QualType& ConvertedType,
2247 bool &IncompatibleObjC) {
2248 IncompatibleObjC = false;
2249 if (isObjCPointerConversion(FromType, ToType, ConvertedType,
2250 IncompatibleObjC))
2251 return true;
2252
2253 // Conversion from a null pointer constant to any Objective-C pointer type.
2254 if (ToType->isObjCObjectPointerType() &&
2255 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) {
2256 ConvertedType = ToType;
2257 return true;
2258 }
2259
2260 // Blocks: Block pointers can be converted to void*.
2261 if (FromType->isBlockPointerType() && ToType->isPointerType() &&
2262 ToType->getAs<PointerType>()->getPointeeType()->isVoidType()) {
2263 ConvertedType = ToType;
2264 return true;
2265 }
2266 // Blocks: A null pointer constant can be converted to a block
2267 // pointer type.
2268 if (ToType->isBlockPointerType() &&
2269 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) {
2270 ConvertedType = ToType;
2271 return true;
2272 }
2273
2274 // If the left-hand-side is nullptr_t, the right side can be a null
2275 // pointer constant.
2276 if (ToType->isNullPtrType() &&
2277 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) {
2278 ConvertedType = ToType;
2279 return true;
2280 }
2281
2282 const PointerType* ToTypePtr = ToType->getAs<PointerType>();
2283 if (!ToTypePtr)
2284 return false;
2285
2286 // A null pointer constant can be converted to a pointer type (C++ 4.10p1).
2287 if (isNullPointerConstantForConversion(From, InOverloadResolution, Context)) {
2288 ConvertedType = ToType;
2289 return true;
2290 }
2291
2292 // Beyond this point, both types need to be pointers
2293 // , including objective-c pointers.
2294 QualType ToPointeeType = ToTypePtr->getPointeeType();
2295 if (FromType->isObjCObjectPointerType() && ToPointeeType->isVoidType() &&
2296 !getLangOpts().ObjCAutoRefCount) {
2297 ConvertedType = BuildSimilarlyQualifiedPointerType(
2298 FromType->getAs<ObjCObjectPointerType>(),
2299 ToPointeeType,
2300 ToType, Context);
2301 return true;
2302 }
2303 const PointerType *FromTypePtr = FromType->getAs<PointerType>();
2304 if (!FromTypePtr)
2305 return false;
2306
2307 QualType FromPointeeType = FromTypePtr->getPointeeType();
2308
2309 // If the unqualified pointee types are the same, this can't be a
2310 // pointer conversion, so don't do all of the work below.
2311 if (Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType))
2312 return false;
2313
2314 // An rvalue of type "pointer to cv T," where T is an object type,
2315 // can be converted to an rvalue of type "pointer to cv void" (C++
2316 // 4.10p2).
2317 if (FromPointeeType->isIncompleteOrObjectType() &&
2318 ToPointeeType->isVoidType()) {
2319 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr,
2320 ToPointeeType,
2321 ToType, Context,
2322 /*StripObjCLifetime=*/true);
2323 return true;
2324 }
2325
2326 // MSVC allows implicit function to void* type conversion.
2327 if (getLangOpts().MSVCCompat && FromPointeeType->isFunctionType() &&
2328 ToPointeeType->isVoidType()) {
2329 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr,
2330 ToPointeeType,
2331 ToType, Context);
2332 return true;
2333 }
2334
2335 // When we're overloading in C, we allow a special kind of pointer
2336 // conversion for compatible-but-not-identical pointee types.
2337 if (!getLangOpts().CPlusPlus &&
2338 Context.typesAreCompatible(FromPointeeType, ToPointeeType)) {
2339 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr,
2340 ToPointeeType,
2341 ToType, Context);
2342 return true;
2343 }
2344
2345 // C++ [conv.ptr]p3:
2346 //
2347 // An rvalue of type "pointer to cv D," where D is a class type,
2348 // can be converted to an rvalue of type "pointer to cv B," where
2349 // B is a base class (clause 10) of D. If B is an inaccessible
2350 // (clause 11) or ambiguous (10.2) base class of D, a program that
2351 // necessitates this conversion is ill-formed. The result of the
2352 // conversion is a pointer to the base class sub-object of the
2353 // derived class object. The null pointer value is converted to
2354 // the null pointer value of the destination type.
2355 //
2356 // Note that we do not check for ambiguity or inaccessibility
2357 // here. That is handled by CheckPointerConversion.
2358 if (getLangOpts().CPlusPlus && FromPointeeType->isRecordType() &&
2359 ToPointeeType->isRecordType() &&
2360 !Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType) &&
2361 IsDerivedFrom(From->getBeginLoc(), FromPointeeType, ToPointeeType)) {
2362 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr,
2363 ToPointeeType,
2364 ToType, Context);
2365 return true;
2366 }
2367
2368 if (FromPointeeType->isVectorType() && ToPointeeType->isVectorType() &&
2369 Context.areCompatibleVectorTypes(FromPointeeType, ToPointeeType)) {
2370 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr,
2371 ToPointeeType,
2372 ToType, Context);
2373 return true;
2374 }
2375
2376 return false;
2377}
2378
2379/// Adopt the given qualifiers for the given type.
2380static QualType AdoptQualifiers(ASTContext &Context, QualType T, Qualifiers Qs){
2381 Qualifiers TQs = T.getQualifiers();
2382
2383 // Check whether qualifiers already match.
2384 if (TQs == Qs)
2385 return T;
2386
2387 if (Qs.compatiblyIncludes(TQs))
2388 return Context.getQualifiedType(T, Qs);
2389
2390 return Context.getQualifiedType(T.getUnqualifiedType(), Qs);
2391}
2392
2393/// isObjCPointerConversion - Determines whether this is an
2394/// Objective-C pointer conversion. Subroutine of IsPointerConversion,
2395/// with the same arguments and return values.
2396bool Sema::isObjCPointerConversion(QualType FromType, QualType ToType,
2397 QualType& ConvertedType,
2398 bool &IncompatibleObjC) {
2399 if (!getLangOpts().ObjC)
2400 return false;
2401
2402 // The set of qualifiers on the type we're converting from.
2403 Qualifiers FromQualifiers = FromType.getQualifiers();
2404
2405 // First, we handle all conversions on ObjC object pointer types.
2406 const ObjCObjectPointerType* ToObjCPtr =
2407 ToType->getAs<ObjCObjectPointerType>();
2408 const ObjCObjectPointerType *FromObjCPtr =
2409 FromType->getAs<ObjCObjectPointerType>();
2410
2411 if (ToObjCPtr && FromObjCPtr) {
2412 // If the pointee types are the same (ignoring qualifications),
2413 // then this is not a pointer conversion.
2414 if (Context.hasSameUnqualifiedType(ToObjCPtr->getPointeeType(),
2415 FromObjCPtr->getPointeeType()))
2416 return false;
2417
2418 // Conversion between Objective-C pointers.
2419 if (Context.canAssignObjCInterfaces(ToObjCPtr, FromObjCPtr)) {
2420 const ObjCInterfaceType* LHS = ToObjCPtr->getInterfaceType();
2421 const ObjCInterfaceType* RHS = FromObjCPtr->getInterfaceType();
2422 if (getLangOpts().CPlusPlus && LHS && RHS &&
2423 !ToObjCPtr->getPointeeType().isAtLeastAsQualifiedAs(
2424 FromObjCPtr->getPointeeType()))
2425 return false;
2426 ConvertedType = BuildSimilarlyQualifiedPointerType(FromObjCPtr,
2427 ToObjCPtr->getPointeeType(),
2428 ToType, Context);
2429 ConvertedType = AdoptQualifiers(Context, ConvertedType, FromQualifiers);
2430 return true;
2431 }
2432
2433 if (Context.canAssignObjCInterfaces(FromObjCPtr, ToObjCPtr)) {
2434 // Okay: this is some kind of implicit downcast of Objective-C
2435 // interfaces, which is permitted. However, we're going to
2436 // complain about it.
2437 IncompatibleObjC = true;
2438 ConvertedType = BuildSimilarlyQualifiedPointerType(FromObjCPtr,
2439 ToObjCPtr->getPointeeType(),
2440 ToType, Context);
2441 ConvertedType = AdoptQualifiers(Context, ConvertedType, FromQualifiers);
2442 return true;
2443 }
2444 }
2445 // Beyond this point, both types need to be C pointers or block pointers.
2446 QualType ToPointeeType;
2447 if (const PointerType *ToCPtr = ToType->getAs<PointerType>())
2448 ToPointeeType = ToCPtr->getPointeeType();
2449 else if (const BlockPointerType *ToBlockPtr =
2450 ToType->getAs<BlockPointerType>()) {
2451 // Objective C++: We're able to convert from a pointer to any object
2452 // to a block pointer type.
2453 if (FromObjCPtr && FromObjCPtr->isObjCBuiltinType()) {
2454 ConvertedType = AdoptQualifiers(Context, ToType, FromQualifiers);
2455 return true;
2456 }
2457 ToPointeeType = ToBlockPtr->getPointeeType();
2458 }
2459 else if (FromType->getAs<BlockPointerType>() &&
2460 ToObjCPtr && ToObjCPtr->isObjCBuiltinType()) {
2461 // Objective C++: We're able to convert from a block pointer type to a
2462 // pointer to any object.
2463 ConvertedType = AdoptQualifiers(Context, ToType, FromQualifiers);
2464 return true;
2465 }
2466 else
2467 return false;
2468
2469 QualType FromPointeeType;
2470 if (const PointerType *FromCPtr = FromType->getAs<PointerType>())
2471 FromPointeeType = FromCPtr->getPointeeType();
2472 else if (const BlockPointerType *FromBlockPtr =
2473 FromType->getAs<BlockPointerType>())
2474 FromPointeeType = FromBlockPtr->getPointeeType();
2475 else
2476 return false;
2477
2478 // If we have pointers to pointers, recursively check whether this
2479 // is an Objective-C conversion.
2480 if (FromPointeeType->isPointerType() && ToPointeeType->isPointerType() &&
2481 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType,
2482 IncompatibleObjC)) {
2483 // We always complain about this conversion.
2484 IncompatibleObjC = true;
2485 ConvertedType = Context.getPointerType(ConvertedType);
2486 ConvertedType = AdoptQualifiers(Context, ConvertedType, FromQualifiers);
2487 return true;
2488 }
2489 // Allow conversion of pointee being objective-c pointer to another one;
2490 // as in I* to id.
2491 if (FromPointeeType->getAs<ObjCObjectPointerType>() &&
2492 ToPointeeType->getAs<ObjCObjectPointerType>() &&
2493 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType,
2494 IncompatibleObjC)) {
2495
2496 ConvertedType = Context.getPointerType(ConvertedType);
2497 ConvertedType = AdoptQualifiers(Context, ConvertedType, FromQualifiers);
2498 return true;
2499 }
2500
2501 // If we have pointers to functions or blocks, check whether the only
2502 // differences in the argument and result types are in Objective-C
2503 // pointer conversions. If so, we permit the conversion (but
2504 // complain about it).
2505 const FunctionProtoType *FromFunctionType
2506 = FromPointeeType->getAs<FunctionProtoType>();
2507 const FunctionProtoType *ToFunctionType
2508 = ToPointeeType->getAs<FunctionProtoType>();
2509 if (FromFunctionType && ToFunctionType) {
2510 // If the function types are exactly the same, this isn't an
2511 // Objective-C pointer conversion.
2512 if (Context.getCanonicalType(FromPointeeType)
2513 == Context.getCanonicalType(ToPointeeType))
2514 return false;
2515
2516 // Perform the quick checks that will tell us whether these
2517 // function types are obviously different.
2518 if (FromFunctionType->getNumParams() != ToFunctionType->getNumParams() ||
2519 FromFunctionType->isVariadic() != ToFunctionType->isVariadic() ||
2520 FromFunctionType->getTypeQuals() != ToFunctionType->getTypeQuals())
2521 return false;
2522
2523 bool HasObjCConversion = false;
2524 if (Context.getCanonicalType(FromFunctionType->getReturnType()) ==
2525 Context.getCanonicalType(ToFunctionType->getReturnType())) {
2526 // Okay, the types match exactly. Nothing to do.
2527 } else if (isObjCPointerConversion(FromFunctionType->getReturnType(),
2528 ToFunctionType->getReturnType(),
2529 ConvertedType, IncompatibleObjC)) {
2530 // Okay, we have an Objective-C pointer conversion.
2531 HasObjCConversion = true;
2532 } else {
2533 // Function types are too different. Abort.
2534 return false;
2535 }
2536
2537 // Check argument types.
2538 for (unsigned ArgIdx = 0, NumArgs = FromFunctionType->getNumParams();
2539 ArgIdx != NumArgs; ++ArgIdx) {
2540 QualType FromArgType = FromFunctionType->getParamType(ArgIdx);
2541 QualType ToArgType = ToFunctionType->getParamType(ArgIdx);
2542 if (Context.getCanonicalType(FromArgType)
2543 == Context.getCanonicalType(ToArgType)) {
2544 // Okay, the types match exactly. Nothing to do.
2545 } else if (isObjCPointerConversion(FromArgType, ToArgType,
2546 ConvertedType, IncompatibleObjC)) {
2547 // Okay, we have an Objective-C pointer conversion.
2548 HasObjCConversion = true;
2549 } else {
2550 // Argument types are too different. Abort.
2551 return false;
2552 }
2553 }
2554
2555 if (HasObjCConversion) {
2556 // We had an Objective-C conversion. Allow this pointer
2557 // conversion, but complain about it.
2558 ConvertedType = AdoptQualifiers(Context, ToType, FromQualifiers);
2559 IncompatibleObjC = true;
2560 return true;
2561 }
2562 }
2563
2564 return false;
2565}
2566
2567/// Determine whether this is an Objective-C writeback conversion,
2568/// used for parameter passing when performing automatic reference counting.
2569///
2570/// \param FromType The type we're converting form.
2571///
2572/// \param ToType The type we're converting to.
2573///
2574/// \param ConvertedType The type that will be produced after applying
2575/// this conversion.
2576bool Sema::isObjCWritebackConversion(QualType FromType, QualType ToType,
2577 QualType &ConvertedType) {
2578 if (!getLangOpts().ObjCAutoRefCount ||
2579 Context.hasSameUnqualifiedType(FromType, ToType))
2580 return false;
2581
2582 // Parameter must be a pointer to __autoreleasing (with no other qualifiers).
2583 QualType ToPointee;
2584 if (const PointerType *ToPointer = ToType->getAs<PointerType>())
2585 ToPointee = ToPointer->getPointeeType();
2586 else
2587 return false;
2588
2589 Qualifiers ToQuals = ToPointee.getQualifiers();
2590 if (!ToPointee->isObjCLifetimeType() ||
2591 ToQuals.getObjCLifetime() != Qualifiers::OCL_Autoreleasing ||
2592 !ToQuals.withoutObjCLifetime().empty())
2593 return false;
2594
2595 // Argument must be a pointer to __strong to __weak.
2596 QualType FromPointee;
2597 if (const PointerType *FromPointer = FromType->getAs<PointerType>())
2598 FromPointee = FromPointer->getPointeeType();
2599 else
2600 return false;
2601
2602 Qualifiers FromQuals = FromPointee.getQualifiers();
2603 if (!FromPointee->isObjCLifetimeType() ||
2604 (FromQuals.getObjCLifetime() != Qualifiers::OCL_Strong &&
2605 FromQuals.getObjCLifetime() != Qualifiers::OCL_Weak))
2606 return false;
2607
2608 // Make sure that we have compatible qualifiers.
2609 FromQuals.setObjCLifetime(Qualifiers::OCL_Autoreleasing);
2610 if (!ToQuals.compatiblyIncludes(FromQuals))
2611 return false;
2612
2613 // Remove qualifiers from the pointee type we're converting from; they
2614 // aren't used in the compatibility check belong, and we'll be adding back
2615 // qualifiers (with __autoreleasing) if the compatibility check succeeds.
2616 FromPointee = FromPointee.getUnqualifiedType();
2617
2618 // The unqualified form of the pointee types must be compatible.
2619 ToPointee = ToPointee.getUnqualifiedType();
2620 bool IncompatibleObjC;
2621 if (Context.typesAreCompatible(FromPointee, ToPointee))
2622 FromPointee = ToPointee;
2623 else if (!isObjCPointerConversion(FromPointee, ToPointee, FromPointee,
2624 IncompatibleObjC))
2625 return false;
2626
2627 /// Construct the type we're converting to, which is a pointer to
2628 /// __autoreleasing pointee.
2629 FromPointee = Context.getQualifiedType(FromPointee, FromQuals);
2630 ConvertedType = Context.getPointerType(FromPointee);
2631 return true;
2632}
2633
2634bool Sema::IsBlockPointerConversion(QualType FromType, QualType ToType,
2635 QualType& ConvertedType) {
2636 QualType ToPointeeType;
2637 if (const BlockPointerType *ToBlockPtr =
2638 ToType->getAs<BlockPointerType>())
2639 ToPointeeType = ToBlockPtr->getPointeeType();
2640 else
2641 return false;
2642
2643 QualType FromPointeeType;
2644 if (const BlockPointerType *FromBlockPtr =
2645 FromType->getAs<BlockPointerType>())
2646 FromPointeeType = FromBlockPtr->getPointeeType();
2647 else
2648 return false;
2649 // We have pointer to blocks, check whether the only
2650 // differences in the argument and result types are in Objective-C
2651 // pointer conversions. If so, we permit the conversion.
2652
2653 const FunctionProtoType *FromFunctionType
2654 = FromPointeeType->getAs<FunctionProtoType>();
2655 const FunctionProtoType *ToFunctionType
2656 = ToPointeeType->getAs<FunctionProtoType>();
2657
2658 if (!FromFunctionType || !ToFunctionType)
2659 return false;
2660
2661 if (Context.hasSameType(FromPointeeType, ToPointeeType))
2662 return true;
2663
2664 // Perform the quick checks that will tell us whether these
2665 // function types are obviously different.
2666 if (FromFunctionType->getNumParams() != ToFunctionType->getNumParams() ||
2667 FromFunctionType->isVariadic() != ToFunctionType->isVariadic())
2668 return false;
2669
2670 FunctionType::ExtInfo FromEInfo = FromFunctionType->getExtInfo();
2671 FunctionType::ExtInfo ToEInfo = ToFunctionType->getExtInfo();
2672 if (FromEInfo != ToEInfo)
2673 return false;
2674
2675 bool IncompatibleObjC = false;
2676 if (Context.hasSameType(FromFunctionType->getReturnType(),
2677 ToFunctionType->getReturnType())) {
2678 // Okay, the types match exactly. Nothing to do.
2679 } else {
2680 QualType RHS = FromFunctionType->getReturnType();
2681 QualType LHS = ToFunctionType->getReturnType();
2682 if ((!getLangOpts().CPlusPlus || !RHS->isRecordType()) &&
2683 !RHS.hasQualifiers() && LHS.hasQualifiers())
2684 LHS = LHS.getUnqualifiedType();
2685
2686 if (Context.hasSameType(RHS,LHS)) {
2687 // OK exact match.
2688 } else if (isObjCPointerConversion(RHS, LHS,
2689 ConvertedType, IncompatibleObjC)) {
2690 if (IncompatibleObjC)
2691 return false;
2692 // Okay, we have an Objective-C pointer conversion.
2693 }
2694 else
2695 return false;
2696 }
2697
2698 // Check argument types.
2699 for (unsigned ArgIdx = 0, NumArgs = FromFunctionType->getNumParams();
2700 ArgIdx != NumArgs; ++ArgIdx) {
2701 IncompatibleObjC = false;
2702 QualType FromArgType = FromFunctionType->getParamType(ArgIdx);
2703 QualType ToArgType = ToFunctionType->getParamType(ArgIdx);
2704 if (Context.hasSameType(FromArgType, ToArgType)) {
2705 // Okay, the types match exactly. Nothing to do.
2706 } else if (isObjCPointerConversion(ToArgType, FromArgType,
2707 ConvertedType, IncompatibleObjC)) {
2708 if (IncompatibleObjC)
2709 return false;
2710 // Okay, we have an Objective-C pointer conversion.
2711 } else
2712 // Argument types are too different. Abort.
2713 return false;
2714 }
2715
2716 SmallVector<FunctionProtoType::ExtParameterInfo, 4> NewParamInfos;
2717 bool CanUseToFPT, CanUseFromFPT;
2718 if (!Context.mergeExtParameterInfo(ToFunctionType, FromFunctionType,
2719 CanUseToFPT, CanUseFromFPT,
2720 NewParamInfos))
2721 return false;
2722
2723 ConvertedType = ToType;
2724 return true;
2725}
2726
2727enum {
2728 ft_default,
2729 ft_different_class,
2730 ft_parameter_arity,
2731 ft_parameter_mismatch,
2732 ft_return_type,
2733 ft_qualifer_mismatch,
2734 ft_noexcept
2735};
2736
2737/// Attempts to get the FunctionProtoType from a Type. Handles
2738/// MemberFunctionPointers properly.
2739static const FunctionProtoType *tryGetFunctionProtoType(QualType FromType) {
2740 if (auto *FPT = FromType->getAs<FunctionProtoType>())
2741 return FPT;
2742
2743 if (auto *MPT = FromType->getAs<MemberPointerType>())
2744 return MPT->getPointeeType()->getAs<FunctionProtoType>();
2745
2746 return nullptr;
2747}
2748
2749/// HandleFunctionTypeMismatch - Gives diagnostic information for differeing
2750/// function types. Catches different number of parameter, mismatch in
2751/// parameter types, and different return types.
2752void Sema::HandleFunctionTypeMismatch(PartialDiagnostic &PDiag,
2753 QualType FromType, QualType ToType) {
2754 // If either type is not valid, include no extra info.
2755 if (FromType.isNull() || ToType.isNull()) {
2756 PDiag << ft_default;
2757 return;
2758 }
2759
2760 // Get the function type from the pointers.
2761 if (FromType->isMemberPointerType() && ToType->isMemberPointerType()) {
2762 const MemberPointerType *FromMember = FromType->getAs<MemberPointerType>(),
2763 *ToMember = ToType->getAs<MemberPointerType>();
2764 if (!Context.hasSameType(FromMember->getClass(), ToMember->getClass())) {
2765 PDiag << ft_different_class << QualType(ToMember->getClass(), 0)
2766 << QualType(FromMember->getClass(), 0);
2767 return;
2768 }
2769 FromType = FromMember->getPointeeType();
2770 ToType = ToMember->getPointeeType();
2771 }
2772
2773 if (FromType->isPointerType())
2774 FromType = FromType->getPointeeType();
2775 if (ToType->isPointerType())
2776 ToType = ToType->getPointeeType();
2777
2778 // Remove references.
2779 FromType = FromType.getNonReferenceType();
2780 ToType = ToType.getNonReferenceType();
2781
2782 // Don't print extra info for non-specialized template functions.
2783 if (FromType->isInstantiationDependentType() &&
2784 !FromType->getAs<TemplateSpecializationType>()) {
2785 PDiag << ft_default;
2786 return;
2787 }
2788
2789 // No extra info for same types.
2790 if (Context.hasSameType(FromType, ToType)) {
2791 PDiag << ft_default;
2792 return;
2793 }
2794
2795 const FunctionProtoType *FromFunction = tryGetFunctionProtoType(FromType),
2796 *ToFunction = tryGetFunctionProtoType(ToType);
2797
2798 // Both types need to be function types.
2799 if (!FromFunction || !ToFunction) {
2800 PDiag << ft_default;
2801 return;
2802 }
2803
2804 if (FromFunction->getNumParams() != ToFunction->getNumParams()) {
2805 PDiag << ft_parameter_arity << ToFunction->getNumParams()
2806 << FromFunction->getNumParams();
2807 return;
2808 }
2809
2810 // Handle different parameter types.
2811 unsigned ArgPos;
2812 if (!FunctionParamTypesAreEqual(FromFunction, ToFunction, &ArgPos)) {
2813 PDiag << ft_parameter_mismatch << ArgPos + 1
2814 << ToFunction->getParamType(ArgPos)
2815 << FromFunction->getParamType(ArgPos);
2816 return;
2817 }
2818
2819 // Handle different return type.
2820 if (!Context.hasSameType(FromFunction->getReturnType(),
2821 ToFunction->getReturnType())) {
2822 PDiag << ft_return_type << ToFunction->getReturnType()
2823 << FromFunction->getReturnType();
2824 return;
2825 }
2826
2827 // FIXME: OpenCL: Need to consider address spaces
2828 unsigned FromQuals = FromFunction->getTypeQuals().getCVRUQualifiers();
2829 unsigned ToQuals = ToFunction->getTypeQuals().getCVRUQualifiers();
2830 if (FromQuals != ToQuals) {
2831 PDiag << ft_qualifer_mismatch << ToQuals << FromQuals;
2832 return;
2833 }
2834
2835 // Handle exception specification differences on canonical type (in C++17
2836 // onwards).
2837 if (cast<FunctionProtoType>(FromFunction->getCanonicalTypeUnqualified())
2838 ->isNothrow() !=
2839 cast<FunctionProtoType>(ToFunction->getCanonicalTypeUnqualified())
2840 ->isNothrow()) {
2841 PDiag << ft_noexcept;
2842 return;
2843 }
2844
2845 // Unable to find a difference, so add no extra info.
2846 PDiag << ft_default;
2847}
2848
2849/// FunctionParamTypesAreEqual - This routine checks two function proto types
2850/// for equality of their argument types. Caller has already checked that
2851/// they have same number of arguments. If the parameters are different,
2852/// ArgPos will have the parameter index of the first different parameter.
2853bool Sema::FunctionParamTypesAreEqual(const FunctionProtoType *OldType,
2854 const FunctionProtoType *NewType,
2855 unsigned *ArgPos) {
2856 for (FunctionProtoType::param_type_iterator O = OldType->param_type_begin(),
2857 N = NewType->param_type_begin(),
2858 E = OldType->param_type_end();
2859 O && (O != E); ++O, ++N) {
2860 if (!Context.hasSameType(O->getUnqualifiedType(),
2861 N->getUnqualifiedType())) {
2862 if (ArgPos)
2863 *ArgPos = O - OldType->param_type_begin();
2864 return false;
2865 }
2866 }
2867 return true;
2868}
2869
2870/// CheckPointerConversion - Check the pointer conversion from the
2871/// expression From to the type ToType. This routine checks for
2872/// ambiguous or inaccessible derived-to-base pointer
2873/// conversions for which IsPointerConversion has already returned
2874/// true. It returns true and produces a diagnostic if there was an
2875/// error, or returns false otherwise.
2876bool Sema::CheckPointerConversion(Expr *From, QualType ToType,
2877 CastKind &Kind,
2878 CXXCastPath& BasePath,
2879 bool IgnoreBaseAccess,
2880 bool Diagnose) {
2881 QualType FromType = From->getType();
2882 bool IsCStyleOrFunctionalCast = IgnoreBaseAccess;
2883
2884 Kind = CK_BitCast;
2885
2886 if (Diagnose && !IsCStyleOrFunctionalCast && !FromType->isAnyPointerType() &&
2887 From->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNotNull) ==
2888 Expr::NPCK_ZeroExpression) {
2889 if (Context.hasSameUnqualifiedType(From->getType(), Context.BoolTy))
2890 DiagRuntimeBehavior(From->getExprLoc(), From,
2891 PDiag(diag::warn_impcast_bool_to_null_pointer)
2892 << ToType << From->getSourceRange());
2893 else if (!isUnevaluatedContext())
2894 Diag(From->getExprLoc(), diag::warn_non_literal_null_pointer)
2895 << ToType << From->getSourceRange();
2896 }
2897 if (const PointerType *ToPtrType = ToType->getAs<PointerType>()) {
2898 if (const PointerType *FromPtrType = FromType->getAs<PointerType>()) {
2899 QualType FromPointeeType = FromPtrType->getPointeeType(),
2900 ToPointeeType = ToPtrType->getPointeeType();
2901
2902 if (FromPointeeType->isRecordType() && ToPointeeType->isRecordType() &&
2903 !Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType)) {
2904 // We must have a derived-to-base conversion. Check an
2905 // ambiguous or inaccessible conversion.
2906 unsigned InaccessibleID = 0;
2907 unsigned AmbigiousID = 0;
2908 if (Diagnose) {
2909 InaccessibleID = diag::err_upcast_to_inaccessible_base;
2910 AmbigiousID = diag::err_ambiguous_derived_to_base_conv;
2911 }
2912 if (CheckDerivedToBaseConversion(
2913 FromPointeeType, ToPointeeType, InaccessibleID, AmbigiousID,
2914 From->getExprLoc(), From->getSourceRange(), DeclarationName(),
2915 &BasePath, IgnoreBaseAccess))
2916 return true;
2917
2918 // The conversion was successful.
2919 Kind = CK_DerivedToBase;
2920 }
2921
2922 if (Diagnose && !IsCStyleOrFunctionalCast &&
2923 FromPointeeType->isFunctionType() && ToPointeeType->isVoidType()) {
2924 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!\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/Sema/SemaOverload.cpp"
, 2925, __PRETTY_FUNCTION__))
2925 "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!\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/Sema/SemaOverload.cpp"
, 2925, __PRETTY_FUNCTION__))
;
2926 Diag(From->getExprLoc(), diag::ext_ms_impcast_fn_obj)
2927 << From->getSourceRange();
2928 }
2929 }
2930 } else if (const ObjCObjectPointerType *ToPtrType =
2931 ToType->getAs<ObjCObjectPointerType>()) {
2932 if (const ObjCObjectPointerType *FromPtrType =
2933 FromType->getAs<ObjCObjectPointerType>()) {
2934 // Objective-C++ conversions are always okay.
2935 // FIXME: We should have a different class of conversions for the
2936 // Objective-C++ implicit conversions.
2937 if (FromPtrType->isObjCBuiltinType() || ToPtrType->isObjCBuiltinType())
2938 return false;
2939 } else if (FromType->isBlockPointerType()) {
2940 Kind = CK_BlockPointerToObjCPointerCast;
2941 } else {
2942 Kind = CK_CPointerToObjCPointerCast;
2943 }
2944 } else if (ToType->isBlockPointerType()) {
2945 if (!FromType->isBlockPointerType())
2946 Kind = CK_AnyPointerToBlockPointerCast;
2947 }
2948
2949 // We shouldn't fall into this case unless it's valid for other
2950 // reasons.
2951 if (From->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull))
2952 Kind = CK_NullToPointer;
2953
2954 return false;
2955}
2956
2957/// IsMemberPointerConversion - Determines whether the conversion of the
2958/// expression From, which has the (possibly adjusted) type FromType, can be
2959/// converted to the type ToType via a member pointer conversion (C++ 4.11).
2960/// If so, returns true and places the converted type (that might differ from
2961/// ToType in its cv-qualifiers at some level) into ConvertedType.
2962bool Sema::IsMemberPointerConversion(Expr *From, QualType FromType,
2963 QualType ToType,
2964 bool InOverloadResolution,
2965 QualType &ConvertedType) {
2966 const MemberPointerType *ToTypePtr = ToType->getAs<MemberPointerType>();
2967 if (!ToTypePtr)
2968 return false;
2969
2970 // A null pointer constant can be converted to a member pointer (C++ 4.11p1)
2971 if (From->isNullPointerConstant(Context,
2972 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull
2973 : Expr::NPC_ValueDependentIsNull)) {
2974 ConvertedType = ToType;
2975 return true;
2976 }
2977
2978 // Otherwise, both types have to be member pointers.
2979 const MemberPointerType *FromTypePtr = FromType->getAs<MemberPointerType>();
2980 if (!FromTypePtr)
2981 return false;
2982
2983 // A pointer to member of B can be converted to a pointer to member of D,
2984 // where D is derived from B (C++ 4.11p2).
2985 QualType FromClass(FromTypePtr->getClass(), 0);
2986 QualType ToClass(ToTypePtr->getClass(), 0);
2987
2988 if (!Context.hasSameUnqualifiedType(FromClass, ToClass) &&
2989 IsDerivedFrom(From->getBeginLoc(), ToClass, FromClass)) {
2990 ConvertedType = Context.getMemberPointerType(FromTypePtr->getPointeeType(),
2991 ToClass.getTypePtr());
2992 return true;
2993 }
2994
2995 return false;
2996}
2997
2998/// CheckMemberPointerConversion - Check the member pointer conversion from the
2999/// expression From to the type ToType. This routine checks for ambiguous or
3000/// virtual or inaccessible base-to-derived member pointer conversions
3001/// for which IsMemberPointerConversion has already returned true. It returns
3002/// true and produces a diagnostic if there was an error, or returns false
3003/// otherwise.
3004bool Sema::CheckMemberPointerConversion(Expr *From, QualType ToType,
3005 CastKind &Kind,
3006 CXXCastPath &BasePath,
3007 bool IgnoreBaseAccess) {
3008 QualType FromType = From->getType();
3009 const MemberPointerType *FromPtrType = FromType->getAs<MemberPointerType>();
3010 if (!FromPtrType) {
3011 // This must be a null pointer to member pointer conversion
3012 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!\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/Sema/SemaOverload.cpp"
, 3014, __PRETTY_FUNCTION__))
3013 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!\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/Sema/SemaOverload.cpp"
, 3014, __PRETTY_FUNCTION__))
3014 "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!\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/Sema/SemaOverload.cpp"
, 3014, __PRETTY_FUNCTION__))
;
3015 Kind = CK_NullToMemberPointer;
3016 return false;
3017 }
3018
3019 const MemberPointerType *ToPtrType = ToType->getAs<MemberPointerType>();
3020 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.\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/Sema/SemaOverload.cpp"
, 3021, __PRETTY_FUNCTION__))
3021 "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.\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/Sema/SemaOverload.cpp"
, 3021, __PRETTY_FUNCTION__))
;
3022
3023 QualType FromClass = QualType(FromPtrType->getClass(), 0);
3024 QualType ToClass = QualType(ToPtrType->getClass(), 0);
3025
3026 // FIXME: What about dependent types?
3027 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.\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/Sema/SemaOverload.cpp"
, 3027, __PRETTY_FUNCTION__))
;
3028 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.\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/Sema/SemaOverload.cpp"
, 3028, __PRETTY_FUNCTION__))
;
3029
3030 CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
3031 /*DetectVirtual=*/true);
3032 bool DerivationOkay =
3033 IsDerivedFrom(From->getBeginLoc(), ToClass, FromClass, Paths);
3034 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.\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/Sema/SemaOverload.cpp"
, 3035, __PRETTY_FUNCTION__))
3035 "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.\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/Sema/SemaOverload.cpp"
, 3035, __PRETTY_FUNCTION__))
;
3036 (void)DerivationOkay;
3037
3038 if (Paths.isAmbiguous(Context.getCanonicalType(FromClass).
3039 getUnqualifiedType())) {
3040 std::string PathDisplayStr = getAmbiguousPathsDisplayString(Paths);
3041 Diag(From->getExprLoc(), diag::err_ambiguous_memptr_conv)
3042 << 0 << FromClass << ToClass << PathDisplayStr << From->getSourceRange();
3043 return true;
3044 }
3045
3046 if (const RecordType *VBase = Paths.getDetectedVirtual()) {
3047 Diag(From->getExprLoc(), diag::err_memptr_conv_via_virtual)
3048 << FromClass << ToClass << QualType(VBase, 0)
3049 << From->getSourceRange();
3050 return true;
3051 }
3052
3053 if (!IgnoreBaseAccess)
3054 CheckBaseClassAccess(From->getExprLoc(), FromClass, ToClass,
3055 Paths.front(),
3056 diag::err_downcast_from_inaccessible_base);
3057
3058 // Must be a base to derived member conversion.
3059 BuildBasePathArray(Paths, BasePath);
3060 Kind = CK_BaseToDerivedMemberPointer;
3061 return false;
3062}
3063
3064/// Determine whether the lifetime conversion between the two given
3065/// qualifiers sets is nontrivial.
3066static bool isNonTrivialObjCLifetimeConversion(Qualifiers FromQuals,
3067 Qualifiers ToQuals) {
3068 // Converting anything to const __unsafe_unretained is trivial.
3069 if (ToQuals.hasConst() &&
3070 ToQuals.getObjCLifetime() == Qualifiers::OCL_ExplicitNone)
3071 return false;
3072
3073 return true;
3074}
3075
3076/// IsQualificationConversion - Determines whether the conversion from
3077/// an rvalue of type FromType to ToType is a qualification conversion
3078/// (C++ 4.4).
3079///
3080/// \param ObjCLifetimeConversion Output parameter that will be set to indicate
3081/// when the qualification conversion involves a change in the Objective-C
3082/// object lifetime.
3083bool
3084Sema::IsQualificationConversion(QualType FromType, QualType ToType,
3085 bool CStyle, bool &ObjCLifetimeConversion) {
3086 FromType = Context.getCanonicalType(FromType);
3087 ToType = Context.getCanonicalType(ToType);
3088 ObjCLifetimeConversion = false;
3089
3090 // If FromType and ToType are the same type, this is not a
3091 // qualification conversion.
3092 if (FromType.getUnqualifiedType() == ToType.getUnqualifiedType())
3093 return false;
3094
3095 // (C++ 4.4p4):
3096 // A conversion can add cv-qualifiers at levels other than the first
3097 // in multi-level pointers, subject to the following rules: [...]
3098 bool PreviousToQualsIncludeConst = true;
3099 bool UnwrappedAnyPointer = false;
3100 while (Context.UnwrapSimilarTypes(FromType, ToType)) {
3101 // Within each iteration of the loop, we check the qualifiers to
3102 // determine if this still looks like a qualification
3103 // conversion. Then, if all is well, we unwrap one more level of
3104 // pointers or pointers-to-members and do it all again
3105 // until there are no more pointers or pointers-to-members left to
3106 // unwrap.
3107 UnwrappedAnyPointer = true;
3108
3109 Qualifiers FromQuals = FromType.getQualifiers();
3110 Qualifiers ToQuals = ToType.getQualifiers();
3111
3112 // Ignore __unaligned qualifier if this type is void.
3113 if (ToType.getUnqualifiedType()->isVoidType())
3114 FromQuals.removeUnaligned();
3115
3116 // Objective-C ARC:
3117 // Check Objective-C lifetime conversions.
3118 if (FromQuals.getObjCLifetime() != ToQuals.getObjCLifetime() &&
3119 UnwrappedAnyPointer) {
3120 if (ToQuals.compatiblyIncludesObjCLifetime(FromQuals)) {
3121 if (isNonTrivialObjCLifetimeConversion(FromQuals, ToQuals))
3122 ObjCLifetimeConversion = true;
3123 FromQuals.removeObjCLifetime();
3124 ToQuals.removeObjCLifetime();
3125 } else {
3126 // Qualification conversions cannot cast between different
3127 // Objective-C lifetime qualifiers.
3128 return false;
3129 }
3130 }
3131
3132 // Allow addition/removal of GC attributes but not changing GC attributes.
3133 if (FromQuals.getObjCGCAttr() != ToQuals.getObjCGCAttr() &&
3134 (!FromQuals.hasObjCGCAttr() || !ToQuals.hasObjCGCAttr())) {
3135 FromQuals.removeObjCGCAttr();
3136 ToQuals.removeObjCGCAttr();
3137 }
3138
3139 // -- for every j > 0, if const is in cv 1,j then const is in cv
3140 // 2,j, and similarly for volatile.
3141 if (!CStyle && !ToQuals.compatiblyIncludes(FromQuals))
3142 return false;
3143
3144 // -- if the cv 1,j and cv 2,j are different, then const is in
3145 // every cv for 0 < k < j.
3146 if (!CStyle && FromQuals.getCVRQualifiers() != ToQuals.getCVRQualifiers()
3147 && !PreviousToQualsIncludeConst)
3148 return false;
3149
3150 // Keep track of whether all prior cv-qualifiers in the "to" type
3151 // include const.
3152 PreviousToQualsIncludeConst
3153 = PreviousToQualsIncludeConst && ToQuals.hasConst();
3154 }
3155
3156 // Allows address space promotion by language rules implemented in
3157 // Type::Qualifiers::isAddressSpaceSupersetOf.
3158 Qualifiers FromQuals = FromType.getQualifiers();
3159 Qualifiers ToQuals = ToType.getQualifiers();
3160 if (!ToQuals.isAddressSpaceSupersetOf(FromQuals) &&
3161 !FromQuals.isAddressSpaceSupersetOf(ToQuals)) {
3162 return false;
3163 }
3164
3165 // We are left with FromType and ToType being the pointee types
3166 // after unwrapping the original FromType and ToType the same number
3167 // of types. If we unwrapped any pointers, and if FromType and
3168 // ToType have the same unqualified type (since we checked
3169 // qualifiers above), then this is a qualification conversion.
3170 return UnwrappedAnyPointer && Context.hasSameUnqualifiedType(FromType,ToType);
3171}
3172
3173/// - Determine whether this is a conversion from a scalar type to an
3174/// atomic type.
3175///
3176/// If successful, updates \c SCS's second and third steps in the conversion
3177/// sequence to finish the conversion.
3178static bool tryAtomicConversion(Sema &S, Expr *From, QualType ToType,
3179 bool InOverloadResolution,
3180 StandardConversionSequence &SCS,
3181 bool CStyle) {
3182 const AtomicType *ToAtomic = ToType->getAs<AtomicType>();
3183 if (!ToAtomic)
3184 return false;
3185
3186 StandardConversionSequence InnerSCS;
3187 if (!IsStandardConversion(S, From, ToAtomic->getValueType(),
3188 InOverloadResolution, InnerSCS,
3189 CStyle, /*AllowObjCWritebackConversion=*/false))
3190 return false;
3191
3192 SCS.Second = InnerSCS.Second;
3193 SCS.setToType(1, InnerSCS.getToType(1));
3194 SCS.Third = InnerSCS.Third;
3195 SCS.QualificationIncludesObjCLifetime
3196 = InnerSCS.QualificationIncludesObjCLifetime;
3197 SCS.setToType(2, InnerSCS.getToType(2));
3198 return true;
3199}
3200
3201static bool isFirstArgumentCompatibleWithType(ASTContext &Context,
3202 CXXConstructorDecl *Constructor,
3203 QualType Type) {
3204 const FunctionProtoType *CtorType =
3205 Constructor->getType()->getAs<FunctionProtoType>();
3206 if (CtorType->getNumParams() > 0) {
3207 QualType FirstArg = CtorType->getParamType(0);
3208 if (Context.hasSameUnqualifiedType(Type, FirstArg.getNonReferenceType()))
3209 return true;
3210 }
3211 return false;
3212}
3213
3214static OverloadingResult
3215IsInitializerListConstructorConversion(Sema &S, Expr *From, QualType ToType,
3216 CXXRecordDecl *To,
3217 UserDefinedConversionSequence &User,
3218 OverloadCandidateSet &CandidateSet,
3219 bool AllowExplicit) {
3220 CandidateSet.clear(OverloadCandidateSet::CSK_InitByUserDefinedConversion);
3221 for (auto *D : S.LookupConstructors(To)) {
3222 auto Info = getConstructorInfo(D);
3223 if (!Info)
3224 continue;
3225
3226 bool Usable = !Info.Constructor->isInvalidDecl() &&
3227 S.isInitListConstructor(Info.Constructor) &&
3228 (AllowExplicit || !Info.Constructor->isExplicit());
3229 if (Usable) {
3230 // If the first argument is (a reference to) the target type,
3231 // suppress conversions.
3232 bool SuppressUserConversions = isFirstArgumentCompatibleWithType(
3233 S.Context, Info.Constructor, ToType);
3234 if (Info.ConstructorTmpl)
3235 S.AddTemplateOverloadCandidate(Info.ConstructorTmpl, Info.FoundDecl,
3236 /*ExplicitArgs*/ nullptr, From,
3237 CandidateSet, SuppressUserConversions);
3238 else
3239 S.AddOverloadCandidate(Info.Constructor, Info.FoundDecl, From,
3240 CandidateSet, SuppressUserConversions);
3241 }
3242 }
3243
3244 bool HadMultipleCandidates = (CandidateSet.size() > 1);
3245
3246 OverloadCandidateSet::iterator Best;
3247 switch (auto Result =
3248 CandidateSet.BestViableFunction(S, From->getBeginLoc(), Best)) {
3249 case OR_Deleted:
3250 case OR_Success: {
3251 // Record the standard conversion we used and the conversion function.
3252 CXXConstructorDecl *Constructor = cast<CXXConstructorDecl>(Best->Function);
3253 QualType ThisType = Constructor->getThisType(S.Context);
3254 // Initializer lists don't have conversions as such.
3255 User.Before.setAsIdentityConversion();
3256 User.HadMultipleCandidates = HadMultipleCandidates;
3257 User.ConversionFunction = Constructor;
3258 User.FoundConversionFunction = Best->FoundDecl;
3259 User.After.setAsIdentityConversion();
3260 User.After.setFromType(ThisType->getAs<PointerType>()->getPointeeType());
3261 User.After.setAllToTypes(ToType);
3262 return Result;
3263 }
3264
3265 case OR_No_Viable_Function:
3266 return OR_No_Viable_Function;
3267 case OR_Ambiguous:
3268 return OR_Ambiguous;
3269 }
3270
3271 llvm_unreachable("Invalid OverloadResult!")::llvm::llvm_unreachable_internal("Invalid OverloadResult!", "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/Sema/SemaOverload.cpp"
, 3271)
;
3272}
3273
3274/// Determines whether there is a user-defined conversion sequence
3275/// (C++ [over.ics.user]) that converts expression From to the type
3276/// ToType. If such a conversion exists, User will contain the
3277/// user-defined conversion sequence that performs such a conversion
3278/// and this routine will return true. Otherwise, this routine returns
3279/// false and User is unspecified.
3280///
3281/// \param AllowExplicit true if the conversion should consider C++0x
3282/// "explicit" conversion functions as well as non-explicit conversion
3283/// functions (C++0x [class.conv.fct]p2).
3284///
3285/// \param AllowObjCConversionOnExplicit true if the conversion should
3286/// allow an extra Objective-C pointer conversion on uses of explicit
3287/// constructors. Requires \c AllowExplicit to also be set.
3288static OverloadingResult
3289IsUserDefinedConversion(Sema &S, Expr *From, QualType ToType,
3290 UserDefinedConversionSequence &User,
3291 OverloadCandidateSet &CandidateSet,
3292 bool AllowExplicit,
3293 bool AllowObjCConversionOnExplicit) {
3294 assert(AllowExplicit || !AllowObjCConversionOnExplicit)((AllowExplicit || !AllowObjCConversionOnExplicit) ? static_cast
<void> (0) : __assert_fail ("AllowExplicit || !AllowObjCConversionOnExplicit"
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/Sema/SemaOverload.cpp"
, 3294, __PRETTY_FUNCTION__))
;
3295 CandidateSet.clear(OverloadCandidateSet::CSK_InitByUserDefinedConversion);
3296
3297 // Whether we will only visit constructors.
3298 bool ConstructorsOnly = false;
3299
3300 // If the type we are conversion to is a class type, enumerate its
3301 // constructors.
3302 if (const RecordType *ToRecordType = ToType->getAs<RecordType>()) {
3303 // C++ [over.match.ctor]p1:
3304 // When objects of class type are direct-initialized (8.5), or
3305 // copy-initialized from an expression of the same or a
3306 // derived class type (8.5), overload resolution selects the
3307 // constructor. [...] For copy-initialization, the candidate
3308 // functions are all the converting constructors (12.3.1) of
3309 // that class. The argument list is the expression-list within
3310 // the parentheses of the initializer.
3311 if (S.Context.hasSameUnqualifiedType(ToType, From->getType()) ||
3312 (From->getType()->getAs<RecordType>() &&
3313 S.IsDerivedFrom(From->getBeginLoc(), From->getType(), ToType)))
3314 ConstructorsOnly = true;
3315
3316 if (!S.isCompleteType(From->getExprLoc(), ToType)) {
3317 // We're not going to find any constructors.
3318 } else if (CXXRecordDecl *ToRecordDecl
3319 = dyn_cast<CXXRecordDecl>(ToRecordType->getDecl())) {
3320
3321 Expr **Args = &From;
3322 unsigned NumArgs = 1;
3323 bool ListInitializing = false;
3324 if (InitListExpr *InitList = dyn_cast<InitListExpr>(From)) {
3325 // But first, see if there is an init-list-constructor that will work.
3326 OverloadingResult Result = IsInitializerListConstructorConversion(
3327 S, From, ToType, ToRecordDecl, User, CandidateSet, AllowExplicit);
3328 if (Result != OR_No_Viable_Function)
3329 return Result;
3330 // Never mind.
3331 CandidateSet.clear(
3332 OverloadCandidateSet::CSK_InitByUserDefinedConversion);
3333
3334 // If we're list-initializing, we pass the individual elements as
3335 // arguments, not the entire list.
3336 Args = InitList->getInits();
3337 NumArgs = InitList->getNumInits();
3338 ListInitializing = true;
3339 }
3340
3341 for (auto *D : S.LookupConstructors(ToRecordDecl)) {
3342 auto Info = getConstructorInfo(D);
3343 if (!Info)
3344 continue;
3345
3346 bool Usable = !Info.Constructor->isInvalidDecl();
3347 if (ListInitializing)
3348 Usable = Usable && (AllowExplicit || !Info.Constructor->isExplicit());
3349 else
3350 Usable = Usable &&
3351 Info.Constructor->isConvertingConstructor(AllowExplicit);
3352 if (Usable) {
3353 bool SuppressUserConversions = !ConstructorsOnly;
3354 if (SuppressUserConversions && ListInitializing) {
3355 SuppressUserConversions = false;
3356 if (NumArgs == 1) {
3357 // If the first argument is (a reference to) the target type,
3358 // suppress conversions.
3359 SuppressUserConversions = isFirstArgumentCompatibleWithType(
3360 S.Context, Info.Constructor, ToType);
3361 }
3362 }
3363 if (Info.ConstructorTmpl)
3364 S.AddTemplateOverloadCandidate(
3365 Info.ConstructorTmpl, Info.FoundDecl,
3366 /*ExplicitArgs*/ nullptr, llvm::makeArrayRef(Args, NumArgs),
3367 CandidateSet, SuppressUserConversions);
3368 else
3369 // Allow one user-defined conversion when user specifies a
3370 // From->ToType conversion via an static cast (c-style, etc).
3371 S.AddOverloadCandidate(Info.Constructor, Info.FoundDecl,
3372 llvm::makeArrayRef(Args, NumArgs),
3373 CandidateSet, SuppressUserConversions);
3374 }
3375 }
3376 }
3377 }
3378
3379 // Enumerate conversion functions, if we're allowed to.
3380 if (ConstructorsOnly || isa<InitListExpr>(From)) {
3381 } else if (!S.isCompleteType(From->getBeginLoc(), From->getType())) {
3382 // No conversion functions from incomplete types.
3383 } else if (const RecordType *FromRecordType =
3384 From->getType()->getAs<RecordType>()) {
3385 if (CXXRecordDecl *FromRecordDecl
3386 = dyn_cast<CXXRecordDecl>(FromRecordType->getDecl())) {
3387 // Add all of the conversion functions as candidates.
3388 const auto &Conversions = FromRecordDecl->getVisibleConversionFunctions();
3389 for (auto I = Conversions.begin(), E = Conversions.end(); I != E; ++I) {
3390 DeclAccessPair FoundDecl = I.getPair();
3391 NamedDecl *D = FoundDecl.getDecl();
3392 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext());
3393 if (isa<UsingShadowDecl>(D))
3394 D = cast<UsingShadowDecl>(D)->getTargetDecl();
3395
3396 CXXConversionDecl *Conv;
3397 FunctionTemplateDecl *ConvTemplate;
3398 if ((ConvTemplate = dyn_cast<FunctionTemplateDecl>(D)))
3399 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl());
3400 else
3401 Conv = cast<CXXConversionDecl>(D);
3402
3403 if (AllowExplicit || !Conv->isExplicit()) {
3404 if (ConvTemplate)
3405 S.AddTemplateConversionCandidate(ConvTemplate, FoundDecl,
3406 ActingContext, From, ToType,
3407 CandidateSet,
3408 AllowObjCConversionOnExplicit);
3409 else
3410 S.AddConversionCandidate(Conv, FoundDecl, ActingContext,
3411 From, ToType, CandidateSet,
3412 AllowObjCConversionOnExplicit);
3413 }
3414 }
3415 }
3416 }
3417
3418 bool HadMultipleCandidates = (CandidateSet.size() > 1);
3419
3420 OverloadCandidateSet::iterator Best;
3421 switch (auto Result =
3422 CandidateSet.BestViableFunction(S, From->getBeginLoc(), Best)) {
3423 case OR_Success:
3424 case OR_Deleted:
3425 // Record the standard conversion we used and the conversion function.
3426 if (CXXConstructorDecl *Constructor
3427 = dyn_cast<CXXConstructorDecl>(Best->Function)) {
3428 // C++ [over.ics.user]p1:
3429 // If the user-defined conversion is specified by a
3430 // constructor (12.3.1), the initial standard conversion
3431 // sequence converts the source type to the type required by
3432 // the argument of the constructor.
3433 //
3434 QualType ThisType = Constructor->getThisType(S.Context);
3435 if (isa<InitListExpr>(From)) {
3436 // Initializer lists don't have conversions as such.
3437 User.Before.setAsIdentityConversion();
3438 } else {
3439 if (Best->Conversions[0].isEllipsis())
3440 User.EllipsisConversion = true;
3441 else {
3442 User.Before = Best->Conversions[0].Standard;
3443 User.EllipsisConversion = false;
3444 }
3445 }
3446 User.HadMultipleCandidates = HadMultipleCandidates;
3447 User.ConversionFunction = Constructor;
3448 User.FoundConversionFunction = Best->FoundDecl;
3449 User.After.setAsIdentityConversion();
3450 User.After.setFromType(ThisType->getAs<PointerType>()->getPointeeType());
3451 User.After.setAllToTypes(ToType);
3452 return Result;
3453 }
3454 if (CXXConversionDecl *Conversion
3455 = dyn_cast<CXXConversionDecl>(Best->Function)) {
3456 // C++ [over.ics.user]p1:
3457 //
3458 // [...] If the user-defined conversion is specified by a
3459 // conversion function (12.3.2), the initial standard
3460 // conversion sequence converts the source type to the
3461 // implicit object parameter of the conversion function.
3462 User.Before = Best->Conversions[0].Standard;
3463 User.HadMultipleCandidates = HadMultipleCandidates;
3464 User.ConversionFunction = Conversion;
3465 User.FoundConversionFunction = Best->FoundDecl;
3466 User.EllipsisConversion = false;
3467
3468 // C++ [over.ics.user]p2:
3469 // The second standard conversion sequence converts the
3470 // result of the user-defined conversion to the target type
3471 // for the sequence. Since an implicit conversion sequence
3472 // is an initialization, the special rules for
3473 // initialization by user-defined conversion apply when
3474 // selecting the best user-defined conversion for a
3475 // user-defined conversion sequence (see 13.3.3 and
3476 // 13.3.3.1).
3477 User.After = Best->FinalConversion;
3478 return Result;
3479 }
3480 llvm_unreachable("Not a constructor or conversion function?")::llvm::llvm_unreachable_internal("Not a constructor or conversion function?"
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/Sema/SemaOverload.cpp"
, 3480)
;
3481
3482 case OR_No_Viable_Function:
3483 return OR_No_Viable_Function;
3484
3485 case OR_Ambiguous:
3486 return OR_Ambiguous;
3487 }
3488
3489 llvm_unreachable("Invalid OverloadResult!")::llvm::llvm_unreachable_internal("Invalid OverloadResult!", "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/Sema/SemaOverload.cpp"
, 3489)
;
3490}
3491
3492bool
3493Sema::DiagnoseMultipleUserDefinedConversion(Expr *From, QualType ToType) {
3494 ImplicitConversionSequence ICS;
3495 OverloadCandidateSet CandidateSet(From->getExprLoc(),
3496 OverloadCandidateSet::CSK_Normal);
3497 OverloadingResult OvResult =
3498 IsUserDefinedConversion(*this, From, ToType, ICS.UserDefined,
3499 CandidateSet, false, false);
3500 if (OvResult == OR_Ambiguous)
3501 Diag(From->getBeginLoc(), diag::err_typecheck_ambiguous_condition)
3502 << From->getType() << ToType << From->getSourceRange();
3503 else if (OvResult == OR_No_Viable_Function && !CandidateSet.empty()) {
3504 if (!RequireCompleteType(From->getBeginLoc(), ToType,
3505 diag::err_typecheck_nonviable_condition_incomplete,
3506 From->getType(), From->getSourceRange()))
3507 Diag(From->getBeginLoc(), diag::err_typecheck_nonviable_condition)
3508 << false << From->getType() << From->getSourceRange() << ToType;
3509 } else
3510 return false;
3511 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, From);
3512 return true;
3513}
3514
3515/// Compare the user-defined conversion functions or constructors
3516/// of two user-defined conversion sequences to determine whether any ordering
3517/// is possible.
3518static ImplicitConversionSequence::CompareKind
3519compareConversionFunctions(Sema &S, FunctionDecl *Function1,
3520 FunctionDecl *Function2) {
3521 if (!S.getLangOpts().ObjC || !S.getLangOpts().CPlusPlus11)
3522 return ImplicitConversionSequence::Indistinguishable;
3523
3524 // Objective-C++:
3525 // If both conversion functions are implicitly-declared conversions from
3526 // a lambda closure type to a function pointer and a block pointer,
3527 // respectively, always prefer the conversion to a function pointer,
3528 // because the function pointer is more lightweight and is more likely
3529 // to keep code working.
3530 CXXConversionDecl *Conv1 = dyn_cast_or_null<CXXConversionDecl>(Function1);
3531 if (!Conv1)
3532 return ImplicitConversionSequence::Indistinguishable;
3533
3534 CXXConversionDecl *Conv2 = dyn_cast<CXXConversionDecl>(Function2);
3535 if (!Conv2)
3536 return ImplicitConversionSequence::Indistinguishable;
3537
3538 if (Conv1->getParent()->isLambda() && Conv2->getParent()->isLambda()) {
3539 bool Block1 = Conv1->getConversionType()->isBlockPointerType();
3540 bool Block2 = Conv2->getConversionType()->isBlockPointerType();
3541 if (Block1 != Block2)
3542 return Block1 ? ImplicitConversionSequence::Worse
3543 : ImplicitConversionSequence::Better;
3544 }
3545
3546 return ImplicitConversionSequence::Indistinguishable;
3547}
3548
3549static bool hasDeprecatedStringLiteralToCharPtrConversion(
3550 const ImplicitConversionSequence &ICS) {
3551 return (ICS.isStandard() && ICS.Standard.DeprecatedStringLiteralToCharPtr) ||
3552 (ICS.isUserDefined() &&
3553 ICS.UserDefined.Before.DeprecatedStringLiteralToCharPtr);
3554}
3555
3556/// CompareImplicitConversionSequences - Compare two implicit
3557/// conversion sequences to determine whether one is better than the
3558/// other or if they are indistinguishable (C++ 13.3.3.2).
3559static ImplicitConversionSequence::CompareKind
3560CompareImplicitConversionSequences(Sema &S, SourceLocation Loc,
3561 const ImplicitConversionSequence& ICS1,
3562 const ImplicitConversionSequence& ICS2)
3563{
3564 // (C++ 13.3.3.2p2): When comparing the basic forms of implicit
3565 // conversion sequences (as defined in 13.3.3.1)
3566 // -- a standard conversion sequence (13.3.3.1.1) is a better
3567 // conversion sequence than a user-defined conversion sequence or
3568 // an ellipsis conversion sequence, and
3569 // -- a user-defined conversion sequence (13.3.3.1.2) is a better
3570 // conversion sequence than an ellipsis conversion sequence
3571 // (13.3.3.1.3).
3572 //
3573 // C++0x [over.best.ics]p10:
3574 // For the purpose of ranking implicit conversion sequences as
3575 // described in 13.3.3.2, the ambiguous conversion sequence is
3576 // treated as a user-defined sequence that is indistinguishable
3577 // from any other user-defined conversion sequence.
3578
3579 // String literal to 'char *' conversion has been deprecated in C++03. It has
3580 // been removed from C++11. We still accept this conversion, if it happens at
3581 // the best viable function. Otherwise, this conversion is considered worse
3582 // than ellipsis conversion. Consider this as an extension; this is not in the
3583 // standard. For example:
3584 //
3585 // int &f(...); // #1
3586 // void f(char*); // #2
3587 // void g() { int &r = f("foo"); }
3588 //
3589 // In C++03, we pick #2 as the best viable function.
3590 // In C++11, we pick #1 as the best viable function, because ellipsis
3591 // conversion is better than string-literal to char* conversion (since there
3592 // is no such conversion in C++11). If there was no #1 at all or #1 couldn't
3593 // convert arguments, #2 would be the best viable function in C++11.
3594 // If the best viable function has this conversion, a warning will be issued
3595 // in C++03, or an ExtWarn (+SFINAE failure) will be issued in C++11.
3596
3597 if (S.getLangOpts().CPlusPlus11 && !S.getLangOpts().WritableStrings &&
3598 hasDeprecatedStringLiteralToCharPtrConversion(ICS1) !=
3599 hasDeprecatedStringLiteralToCharPtrConversion(ICS2))
3600 return hasDeprecatedStringLiteralToCharPtrConversion(ICS1)
3601 ? ImplicitConversionSequence::Worse
3602 : ImplicitConversionSequence::Better;
3603
3604 if (ICS1.getKindRank() < ICS2.getKindRank())
3605 return ImplicitConversionSequence::Better;
3606 if (ICS2.getKindRank() < ICS1.getKindRank())
3607 return ImplicitConversionSequence::Worse;
3608
3609 // The following checks require both conversion sequences to be of
3610 // the same kind.
3611 if (ICS1.getKind() != ICS2.getKind())
3612 return ImplicitConversionSequence::Indistinguishable;
3613
3614 ImplicitConversionSequence::CompareKind Result =
3615 ImplicitConversionSequence::Indistinguishable;
3616
3617 // Two implicit conversion sequences of the same form are
3618 // indistinguishable conversion sequences unless one of the
3619 // following rules apply: (C++ 13.3.3.2p3):
3620
3621 // List-initialization sequence L1 is a better conversion sequence than
3622 // list-initialization sequence L2 if:
3623 // - L1 converts to std::initializer_list<X> for some X and L2 does not, or,
3624 // if not that,
3625 // - L1 converts to type "array of N1 T", L2 converts to type "array of N2 T",
3626 // and N1 is smaller than N2.,
3627 // even if one of the other rules in this paragraph would otherwise apply.
3628 if (!ICS1.isBad()) {
3629 if (ICS1.isStdInitializerListElement() &&
3630 !ICS2.isStdInitializerListElement())
3631 return ImplicitConversionSequence::Better;
3632 if (!ICS1.isStdInitializerListElement() &&
3633 ICS2.isStdInitializerListElement())
3634 return ImplicitConversionSequence::Worse;
3635 }
3636
3637 if (ICS1.isStandard())
3638 // Standard conversion sequence S1 is a better conversion sequence than
3639 // standard conversion sequence S2 if [...]
3640 Result = CompareStandardConversionSequences(S, Loc,
3641 ICS1.Standard, ICS2.Standard);
3642 else if (ICS1.isUserDefined()) {
3643 // User-defined conversion sequence U1 is a better conversion
3644 // sequence than another user-defined conversion sequence U2 if
3645 // they contain the same user-defined conversion function or
3646 // constructor and if the second standard conversion sequence of
3647 // U1 is better than the second standard conversion sequence of
3648 // U2 (C++ 13.3.3.2p3).
3649 if (ICS1.UserDefined.ConversionFunction ==
3650 ICS2.UserDefined.ConversionFunction)
3651 Result = CompareStandardConversionSequences(S, Loc,
3652 ICS1.UserDefined.After,
3653 ICS2.UserDefined.After);
3654 else
3655 Result = compareConversionFunctions(S,
3656 ICS1.UserDefined.ConversionFunction,
3657 ICS2.UserDefined.ConversionFunction);
3658 }
3659
3660 return Result;
3661}
3662
3663// Per 13.3.3.2p3, compare the given standard conversion sequences to
3664// determine if one is a proper subset of the other.
3665static ImplicitConversionSequence::CompareKind
3666compareStandardConversionSubsets(ASTContext &Context,
3667 const StandardConversionSequence& SCS1,
3668 const StandardConversionSequence& SCS2) {
3669 ImplicitConversionSequence::CompareKind Result
3670 = ImplicitConversionSequence::Indistinguishable;
3671
3672 // the identity conversion sequence is considered to be a subsequence of
3673 // any non-identity conversion sequence
3674 if (SCS1.isIdentityConversion() && !SCS2.isIdentityConversion())
3675 return ImplicitConversionSequence::Better;
3676 else if (!SCS1.isIdentityConversion() && SCS2.isIdentityConversion())
3677 return ImplicitConversionSequence::Worse;
3678
3679 if (SCS1.Second != SCS2.Second) {
3680 if (SCS1.Second == ICK_Identity)
3681 Result = ImplicitConversionSequence::Better;
3682 else if (SCS2.Second == ICK_Identity)
3683 Result = ImplicitConversionSequence::Worse;
3684 else
3685 return ImplicitConversionSequence::Indistinguishable;
3686 } else if (!Context.hasSimilarType(SCS1.getToType(1), SCS2.getToType(1)))
3687 return ImplicitConversionSequence::Indistinguishable;
3688
3689 if (SCS1.Third == SCS2.Third) {
3690 return Context.hasSameType(SCS1.getToType(2), SCS2.getToType(2))? Result
3691 : ImplicitConversionSequence::Indistinguishable;
3692 }
3693
3694 if (SCS1.Third == ICK_Identity)
3695 return Result == ImplicitConversionSequence::Worse
3696 ? ImplicitConversionSequence::Indistinguishable
3697 : ImplicitConversionSequence::Better;
3698
3699 if (SCS2.Third == ICK_Identity)
3700 return Result == ImplicitConversionSequence::Better
3701 ? ImplicitConversionSequence::Indistinguishable
3702 : ImplicitConversionSequence::Worse;
3703
3704 return ImplicitConversionSequence::Indistinguishable;
3705}
3706
3707/// Determine whether one of the given reference bindings is better
3708/// than the other based on what kind of bindings they are.
3709static bool
3710isBetterReferenceBindingKind(const StandardConversionSequence &SCS1,
3711 const StandardConversionSequence &SCS2) {
3712 // C++0x [over.ics.rank]p3b4:
3713 // -- S1 and S2 are reference bindings (8.5.3) and neither refers to an
3714 // implicit object parameter of a non-static member function declared
3715 // without a ref-qualifier, and *either* S1 binds an rvalue reference
3716 // to an rvalue and S2 binds an lvalue reference *or S1 binds an
3717 // lvalue reference to a function lvalue and S2 binds an rvalue
3718 // reference*.
3719 //
3720 // FIXME: Rvalue references. We're going rogue with the above edits,
3721 // because the semantics in the current C++0x working paper (N3225 at the
3722 // time of this writing) break the standard definition of std::forward
3723 // and std::reference_wrapper when dealing with references to functions.
3724 // Proposed wording changes submitted to CWG for consideration.
3725 if (SCS1.BindsImplicitObjectArgumentWithoutRefQualifier ||
3726 SCS2.BindsImplicitObjectArgumentWithoutRefQualifier)
3727 return false;
3728
3729 return (!SCS1.IsLvalueReference && SCS1.BindsToRvalue &&
3730 SCS2.IsLvalueReference) ||
3731 (SCS1.IsLvalueReference && SCS1.BindsToFunctionLvalue &&
3732 !SCS2.IsLvalueReference && SCS2.BindsToFunctionLvalue);
3733}
3734
3735/// CompareStandardConversionSequences - Compare two standard
3736/// conversion sequences to determine whether one is better than the
3737/// other or if they are indistinguishable (C++ 13.3.3.2p3).
3738static ImplicitConversionSequence::CompareKind
3739CompareStandardConversionSequences(Sema &S, SourceLocation Loc,
3740 const StandardConversionSequence& SCS1,
3741 const StandardConversionSequence& SCS2)
3742{
3743 // Standard conversion sequence S1 is a better conversion sequence
3744 // than standard conversion sequence S2 if (C++ 13.3.3.2p3):
3745
3746 // -- S1 is a proper subsequence of S2 (comparing the conversion
3747 // sequences in the canonical form defined by 13.3.3.1.1,
3748 // excluding any Lvalue Transformation; the identity conversion
3749 // sequence is considered to be a subsequence of any
3750 // non-identity conversion sequence) or, if not that,
3751 if (ImplicitConversionSequence::CompareKind CK
3752 = compareStandardConversionSubsets(S.Context, SCS1, SCS2))
3753 return CK;
3754
3755 // -- the rank of S1 is better than the rank of S2 (by the rules
3756 // defined below), or, if not that,
3757 ImplicitConversionRank Rank1 = SCS1.getRank();
3758 ImplicitConversionRank Rank2 = SCS2.getRank();
3759 if (Rank1 < Rank2)
3760 return ImplicitConversionSequence::Better;
3761 else if (Rank2 < Rank1)
3762 return ImplicitConversionSequence::Worse;
3763
3764 // (C++ 13.3.3.2p4): Two conversion sequences with the same rank
3765 // are indistinguishable unless one of the following rules
3766 // applies:
3767
3768 // A conversion that is not a conversion of a pointer, or
3769 // pointer to member, to bool is better than another conversion
3770 // that is such a conversion.
3771 if (SCS1.isPointerConversionToBool() != SCS2.isPointerConversionToBool())
3772 return SCS2.isPointerConversionToBool()
3773 ? ImplicitConversionSequence::Better
3774 : ImplicitConversionSequence::Worse;
3775
3776 // C++ [over.ics.rank]p4b2:
3777 //
3778 // If class B is derived directly or indirectly from class A,
3779 // conversion of B* to A* is better than conversion of B* to
3780 // void*, and conversion of A* to void* is better than conversion
3781 // of B* to void*.
3782 bool SCS1ConvertsToVoid
3783 = SCS1.isPointerConversionToVoidPointer(S.Context);
3784 bool SCS2ConvertsToVoid
3785 = SCS2.isPointerConversionToVoidPointer(S.Context);
3786 if (SCS1ConvertsToVoid != SCS2ConvertsToVoid) {
3787 // Exactly one of the conversion sequences is a conversion to
3788 // a void pointer; it's the worse conversion.
3789 return SCS2ConvertsToVoid ? ImplicitConversionSequence::Better
3790 : ImplicitConversionSequence::Worse;
3791 } else if (!SCS1ConvertsToVoid && !SCS2ConvertsToVoid) {
3792 // Neither conversion sequence converts to a void pointer; compare
3793 // their derived-to-base conversions.
3794 if (ImplicitConversionSequence::CompareKind DerivedCK
3795 = CompareDerivedToBaseConversions(S, Loc, SCS1, SCS2))
3796 return DerivedCK;
3797 } else if (SCS1ConvertsToVoid && SCS2ConvertsToVoid &&
3798 !S.Context.hasSameType(SCS1.getFromType(), SCS2.getFromType())) {
3799 // Both conversion sequences are conversions to void
3800 // pointers. Compare the source types to determine if there's an
3801 // inheritance relationship in their sources.
3802 QualType FromType1 = SCS1.getFromType();
3803 QualType FromType2 = SCS2.getFromType();
3804
3805 // Adjust the types we're converting from via the array-to-pointer
3806 // conversion, if we need to.
3807 if (SCS1.First == ICK_Array_To_Pointer)
3808 FromType1 = S.Context.getArrayDecayedType(FromType1);
3809 if (SCS2.First == ICK_Array_To_Pointer)
3810 FromType2 = S.Context.getArrayDecayedType(FromType2);
3811
3812 QualType FromPointee1 = FromType1->getPointeeType().getUnqualifiedType();
3813 QualType FromPointee2 = FromType2->getPointeeType().getUnqualifiedType();
3814
3815 if (S.IsDerivedFrom(Loc, FromPointee2, FromPointee1))
3816 return ImplicitConversionSequence::Better;
3817 else if (S.IsDerivedFrom(Loc, FromPointee1, FromPointee2))
3818 return ImplicitConversionSequence::Worse;
3819
3820 // Objective-C++: If one interface is more specific than the
3821 // other, it is the better one.
3822 const ObjCObjectPointerType* FromObjCPtr1
3823 = FromType1->getAs<ObjCObjectPointerType>();
3824 const ObjCObjectPointerType* FromObjCPtr2
3825 = FromType2->getAs<ObjCObjectPointerType>();
3826 if (FromObjCPtr1 && FromObjCPtr2) {
3827 bool AssignLeft = S.Context.canAssignObjCInterfaces(FromObjCPtr1,
3828 FromObjCPtr2);
3829 bool AssignRight = S.Context.canAssignObjCInterfaces(FromObjCPtr2,
3830 FromObjCPtr1);
3831 if (AssignLeft != AssignRight) {
3832 return AssignLeft? ImplicitConversionSequence::Better
3833 : ImplicitConversionSequence::Worse;
3834 }
3835 }
3836 }
3837
3838 // Compare based on qualification conversions (C++ 13.3.3.2p3,
3839 // bullet 3).
3840 if (ImplicitConversionSequence::CompareKind QualCK
3841 = CompareQualificationConversions(S, SCS1, SCS2))
3842 return QualCK;
3843
3844 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding) {
3845 // Check for a better reference binding based on the kind of bindings.
3846 if (isBetterReferenceBindingKind(SCS1, SCS2))
3847 return ImplicitConversionSequence::Better;
3848 else if (isBetterReferenceBindingKind(SCS2, SCS1))
3849 return ImplicitConversionSequence::Worse;
3850
3851 // C++ [over.ics.rank]p3b4:
3852 // -- S1 and S2 are reference bindings (8.5.3), and the types to
3853 // which the references refer are the same type except for
3854 // top-level cv-qualifiers, and the type to which the reference
3855 // initialized by S2 refers is more cv-qualified than the type
3856 // to which the reference initialized by S1 refers.
3857 QualType T1 = SCS1.getToType(2);
3858 QualType T2 = SCS2.getToType(2);
3859 T1 = S.Context.getCanonicalType(T1);
3860 T2 = S.Context.getCanonicalType(T2);
3861 Qualifiers T1Quals, T2Quals;
3862 QualType UnqualT1 = S.Context.getUnqualifiedArrayType(T1, T1Quals);
3863 QualType UnqualT2 = S.Context.getUnqualifiedArrayType(T2, T2Quals);
3864 if (UnqualT1 == UnqualT2) {
3865 // Objective-C++ ARC: If the references refer to objects with different
3866 // lifetimes, prefer bindings that don't change lifetime.
3867 if (SCS1.ObjCLifetimeConversionBinding !=
3868 SCS2.ObjCLifetimeConversionBinding) {
3869 return SCS1.ObjCLifetimeConversionBinding
3870 ? ImplicitConversionSequence::Worse
3871 : ImplicitConversionSequence::Better;
3872 }
3873
3874 // If the type is an array type, promote the element qualifiers to the
3875 // type for comparison.
3876 if (isa<ArrayType>(T1) && T1Quals)
3877 T1 = S.Context.getQualifiedType(UnqualT1, T1Quals);
3878 if (isa<ArrayType>(T2) && T2Quals)
3879 T2 = S.Context.getQualifiedType(UnqualT2, T2Quals);
3880 if (T2.isMoreQualifiedThan(T1))
3881 return ImplicitConversionSequence::Better;
3882 else if (T1.isMoreQualifiedThan(T2))
3883 return ImplicitConversionSequence::Worse;
3884 }
3885 }
3886
3887 // In Microsoft mode, prefer an integral conversion to a
3888 // floating-to-integral conversion if the integral conversion
3889 // is between types of the same size.
3890 // For example:
3891 // void f(float);
3892 // void f(int);
3893 // int main {
3894 // long a;
3895 // f(a);
3896 // }
3897 // Here, MSVC will call f(int) instead of generating a compile error
3898 // as clang will do in standard mode.
3899 if (S.getLangOpts().MSVCCompat && SCS1.Second == ICK_Integral_Conversion &&
3900 SCS2.Second == ICK_Floating_Integral &&
3901 S.Context.getTypeSize(SCS1.getFromType()) ==
3902 S.Context.getTypeSize(SCS1.getToType(2)))
3903 return ImplicitConversionSequence::Better;
3904
3905 // Prefer a compatible vector conversion over a lax vector conversion
3906 // For example:
3907 //
3908 // typedef float __v4sf __attribute__((__vector_size__(16)));
3909 // void f(vector float);
3910 // void f(vector signed int);
3911 // int main() {
3912 // __v4sf a;
3913 // f(a);
3914 // }
3915 // Here, we'd like to choose f(vector float) and not
3916 // report an ambiguous call error
3917 if (SCS1.Second == ICK_Vector_Conversion &&
3918 SCS2.Second == ICK_Vector_Conversion) {
3919 bool SCS1IsCompatibleVectorConversion = S.Context.areCompatibleVectorTypes(
3920 SCS1.getFromType(), SCS1.getToType(2));
3921 bool SCS2IsCompatibleVectorConversion = S.Context.areCompatibleVectorTypes(
3922 SCS2.getFromType(), SCS2.getToType(2));
3923
3924 if (SCS1IsCompatibleVectorConversion != SCS2IsCompatibleVectorConversion)
3925 return SCS1IsCompatibleVectorConversion
3926 ? ImplicitConversionSequence::Better
3927 : ImplicitConversionSequence::Worse;
3928 }
3929
3930 return ImplicitConversionSequence::Indistinguishable;
3931}
3932
3933/// CompareQualificationConversions - Compares two standard conversion
3934/// sequences to determine whether they can be ranked based on their
3935/// qualification conversions (C++ 13.3.3.2p3 bullet 3).
3936static ImplicitConversionSequence::CompareKind
3937CompareQualificationConversions(Sema &S,
3938 const StandardConversionSequence& SCS1,
3939 const StandardConversionSequence& SCS2) {
3940 // C++ 13.3.3.2p3:
3941 // -- S1 and S2 differ only in their qualification conversion and
3942 // yield similar types T1 and T2 (C++ 4.4), respectively, and the
3943 // cv-qualification signature of type T1 is a proper subset of
3944 // the cv-qualification signature of type T2, and S1 is not the
3945 // deprecated string literal array-to-pointer conversion (4.2).
3946 if (SCS1.First != SCS2.First || SCS1.Second != SCS2.Second ||
3947 SCS1.Third != SCS2.Third || SCS1.Third != ICK_Qualification)
3948 return ImplicitConversionSequence::Indistinguishable;
3949
3950 // FIXME: the example in the standard doesn't use a qualification
3951 // conversion (!)
3952 QualType T1 = SCS1.getToType(2);
3953 QualType T2 = SCS2.getToType(2);
3954 T1 = S.Context.getCanonicalType(T1);
3955 T2 = S.Context.getCanonicalType(T2);
3956 Qualifiers T1Quals, T2Quals;
3957 QualType UnqualT1 = S.Context.getUnqualifiedArrayType(T1, T1Quals);
3958 QualType UnqualT2 = S.Context.getUnqualifiedArrayType(T2, T2Quals);
3959
3960 // If the types are the same, we won't learn anything by unwrapped
3961 // them.
3962 if (UnqualT1 == UnqualT2)
3963 return ImplicitConversionSequence::Indistinguishable;
3964
3965 // If the type is an array type, promote the element qualifiers to the type
3966 // for comparison.
3967 if (isa<ArrayType>(T1) && T1Quals)
3968 T1 = S.Context.getQualifiedType(UnqualT1, T1Quals);
3969 if (isa<ArrayType>(T2) && T2Quals)
3970 T2 = S.Context.getQualifiedType(UnqualT2, T2Quals);
3971
3972 ImplicitConversionSequence::CompareKind Result
3973 = ImplicitConversionSequence::Indistinguishable;
3974
3975 // Objective-C++ ARC:
3976 // Prefer qualification conversions not involving a change in lifetime
3977 // to qualification conversions that do not change lifetime.
3978 if (SCS1.QualificationIncludesObjCLifetime !=
3979 SCS2.QualificationIncludesObjCLifetime) {
3980 Result = SCS1.QualificationIncludesObjCLifetime
3981 ? ImplicitConversionSequence::Worse
3982 : ImplicitConversionSequence::Better;
3983 }
3984
3985 while (S.Context.UnwrapSimilarTypes(T1, T2)) {
3986 // Within each iteration of the loop, we check the qualifiers to
3987 // determine if this still looks like a qualification
3988 // conversion. Then, if all is well, we unwrap one more level of
3989 // pointers or pointers-to-members and do it all again
3990 // until there are no more pointers or pointers-to-members left
3991 // to unwrap. This essentially mimics what
3992 // IsQualificationConversion does, but here we're checking for a
3993 // strict subset of qualifiers.
3994 if (T1.getCVRQualifiers() == T2.getCVRQualifiers())
3995 // The qualifiers are the same, so this doesn't tell us anything
3996 // about how the sequences rank.
3997 ;
3998 else if (T2.isMoreQualifiedThan(T1)) {
3999 // T1 has fewer qualifiers, so it could be the better sequence.
4000 if (Result == ImplicitConversionSequence::Worse)
4001 // Neither has qualifiers that are a subset of the other's
4002 // qualifiers.
4003 return ImplicitConversionSequence::Indistinguishable;
4004
4005 Result = ImplicitConversionSequence::Better;
4006 } else if (T1.isMoreQualifiedThan(T2)) {
4007 // T2 has fewer qualifiers, so it could be the better sequence.
4008 if (Result == ImplicitConversionSequence::Better)
4009 // Neither has qualifiers that are a subset of the other's
4010 // qualifiers.
4011 return ImplicitConversionSequence::Indistinguishable;
4012
4013 Result = ImplicitConversionSequence::Worse;
4014 } else {
4015 // Qualifiers are disjoint.
4016 return ImplicitConversionSequence::Indistinguishable;
4017 }
4018
4019 // If the types after this point are equivalent, we're done.
4020 if (S.Context.hasSameUnqualifiedType(T1, T2))
4021 break;
4022 }
4023
4024 // Check that the winning standard conversion sequence isn't using
4025 // the deprecated string literal array to pointer conversion.
4026 switch (Result) {
4027 case ImplicitConversionSequence::Better:
4028 if (SCS1.DeprecatedStringLiteralToCharPtr)
4029 Result = ImplicitConversionSequence::Indistinguishable;
4030 break;
4031
4032 case ImplicitConversionSequence::Indistinguishable:
4033 break;
4034
4035 case ImplicitConversionSequence::Worse:
4036 if (SCS2.DeprecatedStringLiteralToCharPtr)
4037 Result = ImplicitConversionSequence::Indistinguishable;
4038 break;
4039 }
4040
4041 return Result;
4042}
4043
4044/// CompareDerivedToBaseConversions - Compares two standard conversion
4045/// sequences to determine whether they can be ranked based on their
4046/// various kinds of derived-to-base conversions (C++
4047/// [over.ics.rank]p4b3). As part of these checks, we also look at
4048/// conversions between Objective-C interface types.
4049static ImplicitConversionSequence::CompareKind
4050CompareDerivedToBaseConversions(Sema &S, SourceLocation Loc,
4051 const StandardConversionSequence& SCS1,
4052 const StandardConversionSequence& SCS2) {
4053 QualType FromType1 = SCS1.getFromType();
4054 QualType ToType1 = SCS1.getToType(1);
4055 QualType FromType2 = SCS2.getFromType();
4056 QualType ToType2 = SCS2.getToType(1);
4057
4058 // Adjust the types we're converting from via the array-to-pointer
4059 // conversion, if we need to.
4060 if (SCS1.First == ICK_Array_To_Pointer)
4061 FromType1 = S.Context.getArrayDecayedType(FromType1);
4062 if (SCS2.First == ICK_Array_To_Pointer)
4063 FromType2 = S.Context.getArrayDecayedType(FromType2);
4064
4065 // Canonicalize all of the types.
4066 FromType1 = S.Context.getCanonicalType(FromType1);
4067 ToType1 = S.Context.getCanonicalType(ToType1);
4068 FromType2 = S.Context.getCanonicalType(FromType2);
4069 ToType2 = S.Context.getCanonicalType(ToType2);
4070
4071 // C++ [over.ics.rank]p4b3:
4072 //
4073 // If class B is derived directly or indirectly from class A and
4074 // class C is derived directly or indirectly from B,
4075 //
4076 // Compare based on pointer conversions.
4077 if (SCS1.Second == ICK_Pointer_Conversion &&
4078 SCS2.Second == ICK_Pointer_Conversion &&
4079 /*FIXME: Remove if Objective-C id conversions get their own rank*/
4080 FromType1->isPointerType() && FromType2->isPointerType() &&
4081 ToType1->isPointerType() && ToType2->isPointerType()) {
4082 QualType FromPointee1
4083 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType();
4084 QualType ToPointee1
4085 = ToType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType();
4086 QualType FromPointee2
4087 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType();
4088 QualType ToPointee2
4089 = ToType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType();
4090
4091 // -- conversion of C* to B* is better than conversion of C* to A*,
4092 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) {
4093 if (S.IsDerivedFrom(Loc, ToPointee1, ToPointee2))
4094 return ImplicitConversionSequence::Better;
4095 else if (S.IsDerivedFrom(Loc, ToPointee2, ToPointee1))
4096 return ImplicitConversionSequence::Worse;
4097 }
4098
4099 // -- conversion of B* to A* is better than conversion of C* to A*,
4100 if (FromPointee1 != FromPointee2 && ToPointee1 == ToPointee2) {
4101 if (S.IsDerivedFrom(Loc, FromPointee2, FromPointee1))
4102 return ImplicitConversionSequence::Better;
4103 else if (S.IsDerivedFrom(Loc, FromPointee1, FromPointee2))
4104 return ImplicitConversionSequence::Worse;
4105 }
4106 } else if (SCS1.Second == ICK_Pointer_Conversion &&
4107 SCS2.Second == ICK_Pointer_Conversion) {
4108 const ObjCObjectPointerType *FromPtr1
4109 = FromType1->getAs<ObjCObjectPointerType>();
4110 const ObjCObjectPointerType *FromPtr2
4111 = FromType2->getAs<ObjCObjectPointerType>();
4112 const ObjCObjectPointerType *ToPtr1
4113 = ToType1->getAs<ObjCObjectPointerType>();
4114 const ObjCObjectPointerType *ToPtr2
4115 = ToType2->getAs<ObjCObjectPointerType>();
4116
4117 if (FromPtr1 && FromPtr2 && ToPtr1 && ToPtr2) {
4118 // Apply the same conversion ranking rules for Objective-C pointer types
4119 // that we do for C++ pointers to class types. However, we employ the
4120 // Objective-C pseudo-subtyping relationship used for assignment of
4121 // Objective-C pointer types.
4122 bool FromAssignLeft
4123 = S.Context.canAssignObjCInterfaces(FromPtr1, FromPtr2);
4124 bool FromAssignRight
4125 = S.Context.canAssignObjCInterfaces(FromPtr2, FromPtr1);
4126 bool ToAssignLeft
4127 = S.Context.canAssignObjCInterfaces(ToPtr1, ToPtr2);
4128 bool ToAssignRight
4129 = S.Context.canAssignObjCInterfaces(ToPtr2, ToPtr1);
4130
4131 // A conversion to an a non-id object pointer type or qualified 'id'
4132 // type is better than a conversion to 'id'.
4133 if (ToPtr1->isObjCIdType() &&
4134 (ToPtr2->isObjCQualifiedIdType() || ToPtr2->getInterfaceDecl()))
4135 return ImplicitConversionSequence::Worse;
4136 if (ToPtr2->isObjCIdType() &&
4137 (ToPtr1->isObjCQualifiedIdType() || ToPtr1->getInterfaceDecl()))
4138 return ImplicitConversionSequence::Better;
4139
4140 // A conversion to a non-id object pointer type is better than a
4141 // conversion to a qualified 'id' type
4142 if (ToPtr1->isObjCQualifiedIdType() && ToPtr2->getInterfaceDecl())
4143 return ImplicitConversionSequence::Worse;
4144 if (ToPtr2->isObjCQualifiedIdType() && ToPtr1->getInterfaceDecl())
4145 return ImplicitConversionSequence::Better;
4146
4147 // A conversion to an a non-Class object pointer type or qualified 'Class'
4148 // type is better than a conversion to 'Class'.
4149 if (ToPtr1->isObjCClassType() &&
4150 (ToPtr2->isObjCQualifiedClassType() || ToPtr2->getInterfaceDecl()))
4151 return ImplicitConversionSequence::Worse;
4152 if (ToPtr2->isObjCClassType() &&
4153 (ToPtr1->isObjCQualifiedClassType() || ToPtr1->getInterfaceDecl()))
4154 return ImplicitConversionSequence::Better;
4155
4156 // A conversion to a non-Class object pointer type is better than a
4157 // conversion to a qualified 'Class' type.
4158 if (ToPtr1->isObjCQualifiedClassType() && ToPtr2->getInterfaceDecl())
4159 return ImplicitConversionSequence::Worse;
4160 if (ToPtr2->isObjCQualifiedClassType() && ToPtr1->getInterfaceDecl())
4161 return ImplicitConversionSequence::Better;
4162
4163 // -- "conversion of C* to B* is better than conversion of C* to A*,"
4164 if (S.Context.hasSameType(FromType1, FromType2) &&
4165 !FromPtr1->isObjCIdType() && !FromPtr1->isObjCClassType() &&
4166 (ToAssignLeft != ToAssignRight)) {
4167 if (FromPtr1->isSpecialized()) {
4168 // "conversion of B<A> * to B * is better than conversion of B * to
4169 // C *.
4170 bool IsFirstSame =
4171 FromPtr1->getInterfaceDecl() == ToPtr1->getInterfaceDecl();
4172 bool IsSecondSame =
4173 FromPtr1->getInterfaceDecl() == ToPtr2->getInterfaceDecl();
4174 if (IsFirstSame) {
4175 if (!IsSecondSame)
4176 return ImplicitConversionSequence::Better;
4177 } else if (IsSecondSame)
4178 return ImplicitConversionSequence::Worse;
4179 }
4180 return ToAssignLeft? ImplicitConversionSequence::Worse
4181 : ImplicitConversionSequence::Better;
4182 }
4183
4184 // -- "conversion of B* to A* is better than conversion of C* to A*,"
4185 if (S.Context.hasSameUnqualifiedType(ToType1, ToType2) &&
4186 (FromAssignLeft != FromAssignRight))
4187 return FromAssignLeft? ImplicitConversionSequence::Better
4188 : ImplicitConversionSequence::Worse;
4189 }
4190 }
4191
4192 // Ranking of member-pointer types.
4193 if (SCS1.Second == ICK_Pointer_Member && SCS2.Second == ICK_Pointer_Member &&
4194 FromType1->isMemberPointerType() && FromType2->isMemberPointerType() &&
4195 ToType1->isMemberPointerType() && ToType2->isMemberPointerType()) {
4196 const MemberPointerType * FromMemPointer1 =
4197 FromType1->getAs<MemberPointerType>();
4198 const MemberPointerType * ToMemPointer1 =
4199 ToType1->getAs<MemberPointerType>();
4200 const MemberPointerType * FromMemPointer2 =
4201 FromType2->getAs<MemberPointerType>();
4202 const MemberPointerType * ToMemPointer2 =
4203 ToType2->getAs<MemberPointerType>();
4204 const Type *FromPointeeType1 = FromMemPointer1->getClass();
4205 const Type *ToPointeeType1 = ToMemPointer1->getClass();
4206 const Type *FromPointeeType2 = FromMemPointer2->getClass();
4207 const Type *ToPointeeType2 = ToMemPointer2->getClass();
4208 QualType FromPointee1 = QualType(FromPointeeType1, 0).getUnqualifiedType();
4209 QualType ToPointee1 = QualType(ToPointeeType1, 0).getUnqualifiedType();
4210 QualType FromPointee2 = QualType(FromPointeeType2, 0).getUnqualifiedType();
4211 QualType ToPointee2 = QualType(ToPointeeType2, 0).getUnqualifiedType();
4212 // conversion of A::* to B::* is better than conversion of A::* to C::*,
4213 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) {
4214 if (S.IsDerivedFrom(Loc, ToPointee1, ToPointee2))
4215 return ImplicitConversionSequence::Worse;
4216 else if (S.IsDerivedFrom(Loc, ToPointee2, ToPointee1))
4217 return ImplicitConversionSequence::Better;
4218 }
4219 // conversion of B::* to C::* is better than conversion of A::* to C::*
4220 if (ToPointee1 == ToPointee2 && FromPointee1 != FromPointee2) {
4221 if (S.IsDerivedFrom(Loc, FromPointee1, FromPointee2))
4222 return ImplicitConversionSequence::Better;
4223 else if (S.IsDerivedFrom(Loc, FromPointee2, FromPointee1))
4224 return ImplicitConversionSequence::Worse;
4225 }
4226 }
4227
4228 if (SCS1.Second == ICK_Derived_To_Base) {
4229 // -- conversion of C to B is better than conversion of C to A,
4230 // -- binding of an expression of type C to a reference of type
4231 // B& is better than binding an expression of type C to a
4232 // reference of type A&,
4233 if (S.Context.hasSameUnqualifiedType(FromType1, FromType2) &&
4234 !S.Context.hasSameUnqualifiedType(ToType1, ToType2)) {
4235 if (S.IsDerivedFrom(Loc, ToType1, ToType2))
4236 return ImplicitConversionSequence::Better;
4237 else if (S.IsDerivedFrom(Loc, ToType2, ToType1))
4238 return ImplicitConversionSequence::Worse;
4239 }
4240
4241 // -- conversion of B to A is better than conversion of C to A.
4242 // -- binding of an expression of type B to a reference of type
4243 // A& is better than binding an expression of type C to a
4244 // reference of type A&,
4245 if (!S.Context.hasSameUnqualifiedType(FromType1, FromType2) &&
4246 S.Context.hasSameUnqualifiedType(ToType1, ToType2)) {
4247 if (S.IsDerivedFrom(Loc, FromType2, FromType1))
4248 return ImplicitConversionSequence::Better;
4249 else if (S.IsDerivedFrom(Loc, FromType1, FromType2))
4250 return ImplicitConversionSequence::Worse;
4251 }
4252 }
4253
4254 return ImplicitConversionSequence::Indistinguishable;
4255}
4256
4257/// Determine whether the given type is valid, e.g., it is not an invalid
4258/// C++ class.
4259static bool isTypeValid(QualType T) {
4260 if (CXXRecordDecl *Record = T->getAsCXXRecordDecl())
4261 return !Record->isInvalidDecl();
4262
4263 return true;
4264}
4265
4266/// CompareReferenceRelationship - Compare the two types T1 and T2 to
4267/// determine whether they are reference-related,
4268/// reference-compatible, reference-compatible with added
4269/// qualification, or incompatible, for use in C++ initialization by
4270/// reference (C++ [dcl.ref.init]p4). Neither type can be a reference
4271/// type, and the first type (T1) is the pointee type of the reference
4272/// type being initialized.
4273Sema::ReferenceCompareResult
4274Sema::CompareReferenceRelationship(SourceLocation Loc,
4275 QualType OrigT1, QualType OrigT2,
4276 bool &DerivedToBase,
4277 bool &ObjCConversion,
4278 bool &ObjCLifetimeConversion) {
4279 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\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/Sema/SemaOverload.cpp"
, 4280, __PRETTY_FUNCTION__))
4280 "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\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/Sema/SemaOverload.cpp"
, 4280, __PRETTY_FUNCTION__))
;
4281 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\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/Sema/SemaOverload.cpp"
, 4281, __PRETTY_FUNCTION__))
;
4282
4283 QualType T1 = Context.getCanonicalType(OrigT1);
4284 QualType T2 = Context.getCanonicalType(OrigT2);
4285 Qualifiers T1Quals, T2Quals;
4286 QualType UnqualT1 = Context.getUnqualifiedArrayType(T1, T1Quals);
4287 QualType UnqualT2 = Context.getUnqualifiedArrayType(T2, T2Quals);
4288
4289 // C++ [dcl.init.ref]p4:
4290 // Given types "cv1 T1" and "cv2 T2," "cv1 T1" is
4291 // reference-related to "cv2 T2" if T1 is the same type as T2, or
4292 // T1 is a base class of T2.
4293 DerivedToBase = false;
4294 ObjCConversion = false;
4295 ObjCLifetimeConversion = false;
4296 QualType ConvertedT2;
4297 if (UnqualT1 == UnqualT2) {
4298 // Nothing to do.
4299 } else if (isCompleteType(Loc, OrigT2) &&
4300 isTypeValid(UnqualT1) && isTypeValid(UnqualT2) &&
4301 IsDerivedFrom(Loc, UnqualT2, UnqualT1))
4302 DerivedToBase = true;
4303 else if (UnqualT1->isObjCObjectOrInterfaceType() &&
4304 UnqualT2->isObjCObjectOrInterfaceType() &&
4305 Context.canBindObjCObjectType(UnqualT1, UnqualT2))
4306 ObjCConversion = true;
4307 else if (UnqualT2->isFunctionType() &&
4308 IsFunctionConversion(UnqualT2, UnqualT1, ConvertedT2))
4309 // C++1z [dcl.init.ref]p4:
4310 // cv1 T1" is reference-compatible with "cv2 T2" if [...] T2 is "noexcept
4311 // function" and T1 is "function"
4312 //
4313 // We extend this to also apply to 'noreturn', so allow any function
4314 // conversion between function types.
4315 return Ref_Compatible;
4316 else
4317 return Ref_Incompatible;
4318
4319 // At this point, we know that T1 and T2 are reference-related (at
4320 // least).
4321
4322 // If the type is an array type, promote the element qualifiers to the type
4323 // for comparison.
4324 if (isa<ArrayType>(T1) && T1Quals)
4325 T1 = Context.getQualifiedType(UnqualT1, T1Quals);
4326 if (isa<ArrayType>(T2) && T2Quals)
4327 T2 = Context.getQualifiedType(UnqualT2, T2Quals);
4328
4329 // C++ [dcl.init.ref]p4:
4330 // "cv1 T1" is reference-compatible with "cv2 T2" if T1 is
4331 // reference-related to T2 and cv1 is the same cv-qualification
4332 // as, or greater cv-qualification than, cv2. For purposes of
4333 // overload resolution, cases for which cv1 is greater
4334 // cv-qualification than cv2 are identified as
4335 // reference-compatible with added qualification (see 13.3.3.2).
4336 //
4337 // Note that we also require equivalence of Objective-C GC and address-space
4338 // qualifiers when performing these computations, so that e.g., an int in
4339 // address space 1 is not reference-compatible with an int in address
4340 // space 2.
4341 if (T1Quals.getObjCLifetime() != T2Quals.getObjCLifetime() &&
4342 T1Quals.compatiblyIncludesObjCLifetime(T2Quals)) {
4343 if (isNonTrivialObjCLifetimeConversion(T2Quals, T1Quals))
4344 ObjCLifetimeConversion = true;
4345
4346 T1Quals.removeObjCLifetime();
4347 T2Quals.removeObjCLifetime();
4348 }
4349
4350 // MS compiler ignores __unaligned qualifier for references; do the same.
4351 T1Quals.removeUnaligned();
4352 T2Quals.removeUnaligned();
4353
4354 if (T1Quals.compatiblyIncludes(T2Quals))
4355 return Ref_Compatible;
4356 else
4357 return Ref_Related;
4358}
4359
4360/// Look for a user-defined conversion to a value reference-compatible
4361/// with DeclType. Return true if something definite is found.
4362static bool
4363FindConversionForRefInit(Sema &S, ImplicitConversionSequence &ICS,
4364 QualType DeclType, SourceLocation DeclLoc,
4365 Expr *Init, QualType T2, bool AllowRvalues,
4366 bool AllowExplicit) {
4367 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.\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/Sema/SemaOverload.cpp"
, 4367, __PRETTY_FUNCTION__))
;
4368 CXXRecordDecl *T2RecordDecl
4369 = dyn_cast<CXXRecordDecl>(T2->getAs<RecordType>()->getDecl());
4370
4371 OverloadCandidateSet CandidateSet(
4372 DeclLoc, OverloadCandidateSet::CSK_InitByUserDefinedConversion);
4373 const auto &Conversions = T2RecordDecl->getVisibleConversionFunctions();
4374 for (auto I = Conversions.begin(), E = Conversions.end(); I != E; ++I) {
4375 NamedDecl *D = *I;
4376 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(D->getDeclContext());
4377 if (isa<UsingShadowDecl>(D))
4378 D = cast<UsingShadowDecl>(D)->getTargetDecl();
4379
4380 FunctionTemplateDecl *ConvTemplate
4381 = dyn_cast<FunctionTemplateDecl>(D);
4382 CXXConversionDecl *Conv;
4383 if (ConvTemplate)
4384 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl());
4385 else
4386 Conv = cast<CXXConversionDecl>(D);
4387
4388 // If this is an explicit conversion, and we're not allowed to consider
4389 // explicit conversions, skip it.
4390 if (!AllowExplicit && Conv->isExplicit())
4391 continue;
4392
4393 if (AllowRvalues) {
4394 bool DerivedToBase = false;
4395 bool ObjCConversion = false;
4396 bool ObjCLifetimeConversion = false;
4397
4398 // If we are initializing an rvalue reference, don't permit conversion
4399 // functions that return lvalues.
4400 if (!ConvTemplate && DeclType->isRValueReferenceType()) {
4401 const ReferenceType *RefType
4402 = Conv->getConversionType()->getAs<LValueReferenceType>();
4403 if (RefType && !RefType->getPointeeType()->isFunctionType())
4404 continue;
4405 }
4406
4407 if (!ConvTemplate &&
4408 S.CompareReferenceRelationship(
4409 DeclLoc,
4410 Conv->getConversionType().getNonReferenceType()
4411 .getUnqualifiedType(),
4412 DeclType.getNonReferenceType().getUnqualifiedType(),
4413 DerivedToBase, ObjCConversion, ObjCLifetimeConversion) ==
4414 Sema::Ref_Incompatible)
4415 continue;
4416 } else {
4417 // If the conversion function doesn't return a reference type,
4418 // it can't be considered for this conversion. An rvalue reference
4419 // is only acceptable if its referencee is a function type.
4420
4421 const ReferenceType *RefType =
4422 Conv->getConversionType()->getAs<ReferenceType>();
4423 if (!RefType ||
4424 (!RefType->isLValueReferenceType() &&
4425 !RefType->getPointeeType()->isFunctionType()))
4426 continue;
4427 }
4428
4429 if (ConvTemplate)
4430 S.AddTemplateConversionCandidate(ConvTemplate, I.getPair(), ActingDC,
4431 Init, DeclType, CandidateSet,
4432 /*AllowObjCConversionOnExplicit=*/false);
4433 else
4434 S.AddConversionCandidate(Conv, I.getPair(), ActingDC, Init,
4435 DeclType, CandidateSet,
4436 /*AllowObjCConversionOnExplicit=*/false);
4437 }
4438
4439 bool HadMultipleCandidates = (CandidateSet.size() > 1);
4440
4441 OverloadCandidateSet::iterator Best;
4442 switch (CandidateSet.BestViableFunction(S, DeclLoc, Best)) {
4443 case OR_Success:
4444 // C++ [over.ics.ref]p1:
4445 //
4446 // [...] If the parameter binds directly to the result of
4447 // applying a conversion function to the argument
4448 // expression, the implicit conversion sequence is a
4449 // user-defined conversion sequence (13.3.3.1.2), with the
4450 // second standard conversion sequence either an identity
4451 // conversion or, if the conversion function returns an
4452 // entity of a type that is a derived class of the parameter
4453 // type, a derived-to-base Conversion.
4454 if (!Best->FinalConversion.DirectBinding)
4455 return false;
4456
4457 ICS.setUserDefined();
4458 ICS.UserDefined.Before = Best->Conversions[0].Standard;
4459 ICS.UserDefined.After = Best->FinalConversion;
4460 ICS.UserDefined.HadMultipleCandidates = HadMultipleCandidates;
4461 ICS.UserDefined.ConversionFunction = Best->Function;
4462 ICS.UserDefined.FoundConversionFunction = Best->FoundDecl;
4463 ICS.UserDefined.EllipsisConversion = false;
4464 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!\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/Sema/SemaOverload.cpp"
, 4466, __PRETTY_FUNCTION__))
4465 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!\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/Sema/SemaOverload.cpp"
, 4466, __PRETTY_FUNCTION__))
4466 "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!\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/Sema/SemaOverload.cpp"
, 4466, __PRETTY_FUNCTION__))
;
4467 return true;
4468
4469 case OR_Ambiguous:
4470 ICS.setAmbiguous();
4471 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin();
4472 Cand != CandidateSet.end(); ++Cand)
4473 if (Cand->Viable)
4474 ICS.Ambiguous.addConversion(Cand->FoundDecl, Cand->Function);
4475 return true;
4476
4477 case OR_No_Viable_Function:
4478 case OR_Deleted:
4479 // There was no suitable conversion, or we found a deleted
4480 // conversion; continue with other checks.
4481 return false;
4482 }
4483
4484 llvm_unreachable("Invalid OverloadResult!")::llvm::llvm_unreachable_internal("Invalid OverloadResult!", "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/Sema/SemaOverload.cpp"
, 4484)
;
4485}
4486
4487/// Compute an implicit conversion sequence for reference
4488/// initialization.
4489static ImplicitConversionSequence
4490TryReferenceInit(Sema &S, Expr *Init, QualType DeclType,
4491 SourceLocation DeclLoc,
4492 bool SuppressUserConversions,
4493 bool AllowExplicit) {
4494 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\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/Sema/SemaOverload.cpp"
, 4494, __PRETTY_FUNCTION__))
;
4495
4496 // Most paths end in a failed conversion.
4497 ImplicitConversionSequence ICS;
4498 ICS.setBad(BadConversionSequence::no_conversion, Init, DeclType);
4499
4500 QualType T1 = DeclType->getAs<ReferenceType>()->getPointeeType();
4501 QualType T2 = Init->getType();
4502
4503 // If the initializer is the address of an overloaded function, try
4504 // to resolve the overloaded function. If all goes well, T2 is the
4505 // type of the resulting function.
4506 if (S.Context.getCanonicalType(T2) == S.Context.OverloadTy) {
4507 DeclAccessPair Found;
4508 if (FunctionDecl *Fn = S.ResolveAddressOfOverloadedFunction(Init, DeclType,
4509 false, Found))
4510 T2 = Fn->getType();
4511 }
4512
4513 // Compute some basic properties of the types and the initializer.
4514 bool isRValRef = DeclType->isRValueReferenceType();
4515 bool DerivedToBase = false;
4516 bool ObjCConversion = false;
4517 bool ObjCLifetimeConversion = false;
4518 Expr::Classification InitCategory = Init->Classify(S.Context);
4519 Sema::ReferenceCompareResult RefRelationship
4520 = S.CompareReferenceRelationship(DeclLoc, T1, T2, DerivedToBase,
4521 ObjCConversion, ObjCLifetimeConversion);
4522
4523
4524 // C++0x [dcl.init.ref]p5:
4525 // A reference to type "cv1 T1" is initialized by an expression
4526 // of type "cv2 T2" as follows:
4527
4528 // -- If reference is an lvalue reference and the initializer expression
4529 if (!isRValRef) {
4530 // -- is an lvalue (but is not a bit-field), and "cv1 T1" is
4531 // reference-compatible with "cv2 T2," or
4532 //
4533 // Per C++ [over.ics.ref]p4, we don't check the bit-field property here.
4534 if (InitCategory.isLValue() && RefRelationship == Sema::Ref_Compatible) {
4535 // C++ [over.ics.ref]p1:
4536 // When a parameter of reference type binds directly (8.5.3)
4537 // to an argument expression, the implicit conversion sequence
4538 // is the identity conversion, unless the argument expression
4539 // has a type that is a derived class of the parameter type,
4540 // in which case the implicit conversion sequence is a
4541 // derived-to-base Conversion (13.3.3.1).
4542 ICS.setStandard();
4543 ICS.Standard.First = ICK_Identity;
4544 ICS.Standard.Second = DerivedToBase? ICK_Derived_To_Base
4545 : ObjCConversion? ICK_Compatible_Conversion
4546 : ICK_Identity;
4547 ICS.Standard.Third = ICK_Identity;
4548 ICS.Standard.FromTypePtr = T2.getAsOpaquePtr();
4549 ICS.Standard.setToType(0, T2);
4550 ICS.Standard.setToType(1, T1);
4551 ICS.Standard.setToType(2, T1);
4552 ICS.Standard.ReferenceBinding = true;
4553 ICS.Standard.DirectBinding = true;
4554 ICS.Standard.IsLvalueReference = !isRValRef;
4555 ICS.Standard.BindsToFunctionLvalue = T2->isFunctionType();
4556 ICS.Standard.BindsToRvalue = false;
4557 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier = false;
4558 ICS.Standard.ObjCLifetimeConversionBinding = ObjCLifetimeConversion;
4559 ICS.Standard.CopyConstructor = nullptr;
4560 ICS.Standard.DeprecatedStringLiteralToCharPtr = false;
4561
4562 // Nothing more to do: the inaccessibility/ambiguity check for
4563 // derived-to-base conversions is suppressed when we're
4564 // computing the implicit conversion sequence (C++
4565 // [over.best.ics]p2).
4566 return ICS;
4567 }
4568
4569 // -- has a class type (i.e., T2 is a class type), where T1 is
4570 // not reference-related to T2, and can be implicitly
4571 // converted to an lvalue of type "cv3 T3," where "cv1 T1"
4572 // is reference-compatible with "cv3 T3" 92) (this
4573 // conversion is selected by enumerating the applicable
4574 // conversion functions (13.3.1.6) and choosing the best
4575 // one through overload resolution (13.3)),
4576 if (!SuppressUserConversions && T2->isRecordType() &&
4577 S.isCompleteType(DeclLoc, T2) &&
4578 RefRelationship == Sema::Ref_Incompatible) {
4579 if (FindConversionForRefInit(S, ICS, DeclType, DeclLoc,
4580 Init, T2, /*AllowRvalues=*/false,
4581 AllowExplicit))
4582 return ICS;
4583 }
4584 }
4585
4586 // -- Otherwise, the reference shall be an lvalue reference to a
4587 // non-volatile const type (i.e., cv1 shall be const), or the reference
4588 // shall be an rvalue reference.
4589 if (!isRValRef && (!T1.isConstQualified() || T1.isVolatileQualified()))
4590 return ICS;
4591
4592 // -- If the initializer expression
4593 //
4594 // -- is an xvalue, class prvalue, array prvalue or function
4595 // lvalue and "cv1 T1" is reference-compatible with "cv2 T2", or
4596 if (RefRelationship == Sema::Ref_Compatible &&
4597 (InitCategory.isXValue() ||
4598 (InitCategory.isPRValue() && (T2->isRecordType() || T2->isArrayType())) ||
4599 (InitCategory.isLValue() && T2->isFunctionType()))) {
4600 ICS.setStandard();
4601 ICS.Standard.First = ICK_Identity;
4602 ICS.Standard.Second = DerivedToBase? ICK_Derived_To_Base
4603 : ObjCConversion? ICK_Compatible_Conversion
4604 : ICK_Identity;
4605 ICS.Standard.Third = ICK_Identity;
4606 ICS.Standard.FromTypePtr = T2.getAsOpaquePtr();
4607 ICS.Standard.setToType(0, T2);
4608 ICS.Standard.setToType(1, T1);
4609 ICS.Standard.setToType(2, T1);
4610 ICS.Standard.ReferenceBinding = true;
4611 // In C++0x, this is always a direct binding. In C++98/03, it's a direct
4612 // binding unless we're binding to a class prvalue.
4613 // Note: Although xvalues wouldn't normally show up in C++98/03 code, we
4614 // allow the use of rvalue references in C++98/03 for the benefit of
4615 // standard library implementors; therefore, we need the xvalue check here.
4616 ICS.Standard.DirectBinding =
4617 S.getLangOpts().CPlusPlus11 ||
4618 !(InitCategory.isPRValue() || T2->isRecordType());
4619 ICS.Standard.IsLvalueReference = !isRValRef;
4620 ICS.Standard.BindsToFunctionLvalue = T2->isFunctionType();
4621 ICS.Standard.BindsToRvalue = InitCategory.isRValue();
4622 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier = false;
4623 ICS.Standard.ObjCLifetimeConversionBinding = ObjCLifetimeConversion;
4624 ICS.Standard.CopyConstructor = nullptr;
4625 ICS.Standard.DeprecatedStringLiteralToCharPtr = false;
4626 return ICS;
4627 }
4628
4629 // -- has a class type (i.e., T2 is a class type), where T1 is not
4630 // reference-related to T2, and can be implicitly converted to
4631 // an xvalue, class prvalue, or function lvalue of type
4632 // "cv3 T3", where "cv1 T1" is reference-compatible with
4633 // "cv3 T3",
4634 //
4635 // then the reference is bound to the value of the initializer
4636 // expression in the first case and to the result of the conversion
4637 // in the second case (or, in either case, to an appropriate base
4638 // class subobject).
4639 if (!SuppressUserConversions && RefRelationship == Sema::Ref_Incompatible &&
4640 T2->isRecordType() && S.isCompleteType(DeclLoc, T2) &&
4641 FindConversionForRefInit(S, ICS, DeclType, DeclLoc,
4642 Init, T2, /*AllowRvalues=*/true,
4643 AllowExplicit)) {
4644 // In the second case, if the reference is an rvalue reference
4645 // and the second standard conversion sequence of the
4646 // user-defined conversion sequence includes an lvalue-to-rvalue
4647 // conversion, the program is ill-formed.
4648 if (ICS.isUserDefined() && isRValRef &&
4649 ICS.UserDefined.After.First == ICK_Lvalue_To_Rvalue)
4650 ICS.setBad(BadConversionSequence::no_conversion, Init, DeclType);
4651
4652 return ICS;
4653 }
4654
4655 // A temporary of function type cannot be created; don't even try.
4656 if (T1->isFunctionType())
4657 return ICS;
4658
4659 // -- Otherwise, a temporary of type "cv1 T1" is created and
4660 // initialized from the initializer expression using the
4661 // rules for a non-reference copy initialization (8.5). The
4662 // reference is then bound to the temporary. If T1 is
4663 // reference-related to T2, cv1 must be the same
4664 // cv-qualification as, or greater cv-qualification than,
4665 // cv2; otherwise, the program is ill-formed.
4666 if (RefRelationship == Sema::Ref_Related) {
4667 // If cv1 == cv2 or cv1 is a greater cv-qualified than cv2, then
4668 // we would be reference-compatible or reference-compatible with
4669 // added qualification. But that wasn't the case, so the reference
4670 // initialization fails.
4671 //
4672 // Note that we only want to check address spaces and cvr-qualifiers here.
4673 // ObjC GC, lifetime and unaligned qualifiers aren't important.
4674 Qualifiers T1Quals = T1.getQualifiers();
4675 Qualifiers T2Quals = T2.getQualifiers();
4676 T1Quals.removeObjCGCAttr();
4677 T1Quals.removeObjCLifetime();
4678 T2Quals.removeObjCGCAttr();
4679 T2Quals.removeObjCLifetime();
4680 // MS compiler ignores __unaligned qualifier for references; do the same.
4681 T1Quals.removeUnaligned();
4682 T2Quals.removeUnaligned();
4683 if (!T1Quals.compatiblyIncludes(T2Quals))
4684 return ICS;
4685 }
4686
4687 // If at least one of the types is a class type, the types are not
4688 // related, and we aren't allowed any user conversions, the
4689 // reference binding fails. This case is important for breaking
4690 // recursion, since TryImplicitConversion below will attempt to
4691 // create a temporary through the use of a copy constructor.
4692 if (SuppressUserConversions && RefRelationship == Sema::Ref_Incompatible &&
4693 (T1->isRecordType() || T2->isRecordType()))
4694 return ICS;
4695
4696 // If T1 is reference-related to T2 and the reference is an rvalue
4697 // reference, the initializer expression shall not be an lvalue.
4698 if (RefRelationship >= Sema::Ref_Related &&
4699 isRValRef && Init->Classify(S.Context).isLValue())
4700 return ICS;
4701
4702 // C++ [over.ics.ref]p2:
4703 // When a parameter of reference type is not bound directly to
4704 // an argument expression, the conversion sequence is the one
4705 // required to convert the argument expression to the
4706 // underlying type of the reference according to
4707 // 13.3.3.1. Conceptually, this conversion sequence corresponds
4708 // to copy-initializing a temporary of the underlying type with
4709 // the argument expression. Any difference in top-level
4710 // cv-qualification is subsumed by the initialization itself
4711 // and does not constitute a conversion.
4712 ICS = TryImplicitConversion(S, Init, T1, SuppressUserConversions,
4713 /*AllowExplicit=*/false,
4714 /*InOverloadResolution=*/false,
4715 /*CStyle=*/false,
4716 /*AllowObjCWritebackConversion=*/false,
4717 /*AllowObjCConversionOnExplicit=*/false);
4718
4719 // Of course, that's still a reference binding.
4720 if (ICS.isStandard()) {
4721 ICS.Standard.ReferenceBinding = true;
4722 ICS.Standard.IsLvalueReference = !isRValRef;
4723 ICS.Standard.BindsToFunctionLvalue = false;
4724 ICS.Standard.BindsToRvalue = true;
4725 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier = false;
4726 ICS.Standard.ObjCLifetimeConversionBinding = false;
4727 } else if (ICS.isUserDefined()) {
4728 const ReferenceType *LValRefType =
4729 ICS.UserDefined.ConversionFunction->getReturnType()
4730 ->getAs<LValueReferenceType>();
4731
4732 // C++ [over.ics.ref]p3:
4733 // Except for an implicit object parameter, for which see 13.3.1, a
4734 // standard conversion sequence cannot be formed if it requires [...]
4735 // binding an rvalue reference to an lvalue other than a function
4736 // lvalue.
4737 // Note that the function case is not possible here.
4738 if (DeclType->isRValueReferenceType() && LValRefType) {
4739 // FIXME: This is the wrong BadConversionSequence. The problem is binding
4740 // an rvalue reference to a (non-function) lvalue, not binding an lvalue
4741 // reference to an rvalue!
4742 ICS.setBad(BadConversionSequence::lvalue_ref_to_rvalue, Init, DeclType);
4743 return ICS;
4744 }
4745
4746 ICS.UserDefined.After.ReferenceBinding = true;
4747 ICS.UserDefined.After.IsLvalueReference = !isRValRef;
4748 ICS.UserDefined.After.BindsToFunctionLvalue = false;
4749 ICS.UserDefined.After.BindsToRvalue = !LValRefType;
4750 ICS.UserDefined.After.BindsImplicitObjectArgumentWithoutRefQualifier = false;
4751 ICS.UserDefined.After.ObjCLifetimeConversionBinding = false;
4752 }
4753
4754 return ICS;
4755}
4756
4757static ImplicitConversionSequence
4758TryCopyInitialization(Sema &S, Expr *From, QualType ToType,
4759 bool SuppressUserConversions,
4760 bool InOverloadResolution,
4761 bool AllowObjCWritebackConversion,
4762 bool AllowExplicit = false);
4763
4764/// TryListConversion - Try to copy-initialize a value of type ToType from the
4765/// initializer list From.
4766static ImplicitConversionSequence
4767TryListConversion(Sema &S, InitListExpr *From, QualType ToType,
4768 bool SuppressUserConversions,
4769 bool InOverloadResolution,
4770 bool AllowObjCWritebackConversion) {
4771 // C++11 [over.ics.list]p1:
4772 // When an argument is an initializer list, it is not an expression and
4773 // special rules apply for converting it to a parameter type.
4774
4775 ImplicitConversionSequence Result;
4776 Result.setBad(BadConversionSequence::no_conversion, From, ToType);
4777
4778 // We need a complete type for what follows. Incomplete types can never be
4779 // initialized from init lists.
4780 if (!S.isCompleteType(From->getBeginLoc(), ToType))
4781 return Result;
4782
4783 // Per DR1467:
4784 // If the parameter type is a class X and the initializer list has a single
4785 // element of type cv U, where U is X or a class derived from X, the
4786 // implicit conversion sequence is the one required to convert the element
4787 // to the parameter type.
4788 //
4789 // Otherwise, if the parameter type is a character array [... ]
4790 // and the initializer list has a single element that is an
4791 // appropriately-typed string literal (8.5.2 [dcl.init.string]), the
4792 // implicit conversion sequence is the identity conversion.
4793 if (From->getNumInits() == 1) {
4794 if (ToType->isRecordType()) {
4795 QualType InitType = From->getInit(0)->getType();
4796 if (S.Context.hasSameUnqualifiedType(InitType, ToType) ||
4797 S.IsDerivedFrom(From->getBeginLoc(), InitType, ToType))
4798 return TryCopyInitialization(S, From->getInit(0), ToType,
4799 SuppressUserConversions,
4800 InOverloadResolution,
4801 AllowObjCWritebackConversion);
4802 }
4803 // FIXME: Check the other conditions here: array of character type,
4804 // initializer is a string literal.
4805 if (ToType->isArrayType()) {
4806 InitializedEntity Entity =
4807 InitializedEntity::InitializeParameter(S.Context, ToType,
4808 /*Consumed=*/false);
4809 if (S.CanPerformCopyInitialization(Entity, From)) {
4810 Result.setStandard();
4811 Result.Standard.setAsIdentityConversion();
4812 Result.Standard.setFromType(ToType);
4813 Result.Standard.setAllToTypes(ToType);
4814 return Result;
4815 }
4816 }
4817 }
4818
4819 // C++14 [over.ics.list]p2: Otherwise, if the parameter type [...] (below).
4820 // C++11 [over.ics.list]p2:
4821 // If the parameter type is std::initializer_list<X> or "array of X" and
4822 // all the elements can be implicitly converted to X, the implicit
4823 // conversion sequence is the worst conversion necessary to convert an
4824 // element of the list to X.
4825 //
4826 // C++14 [over.ics.list]p3:
4827 // Otherwise, if the parameter type is "array of N X", if the initializer
4828 // list has exactly N elements or if it has fewer than N elements and X is
4829 // default-constructible, and if all the elements of the initializer list
4830 // can be implicitly converted to X, the implicit conversion sequence is
4831 // the worst conversion necessary to convert an element of the list to X.
4832 //
4833 // FIXME: We're missing a lot of these checks.
4834 bool toStdInitializerList = false;
4835 QualType X;
4836 if (ToType->isArrayType())
4837 X = S.Context.getAsArrayType(ToType)->getElementType();
4838 else
4839 toStdInitializerList = S.isStdInitializerList(ToType, &X);
4840 if (!X.isNull()) {
4841 for (unsigned i = 0, e = From->getNumInits(); i < e; ++i) {
4842 Expr *Init = From->getInit(i);
4843 ImplicitConversionSequence ICS =
4844 TryCopyInitialization(S, Init, X, SuppressUserConversions,
4845 InOverloadResolution,
4846 AllowObjCWritebackConversion);
4847 // If a single element isn't convertible, fail.
4848 if (ICS.isBad()) {
4849 Result = ICS;
4850 break;
4851 }
4852 // Otherwise, look for the worst conversion.
4853 if (Result.isBad() || CompareImplicitConversionSequences(
4854 S, From->getBeginLoc(), ICS, Result) ==
4855 ImplicitConversionSequence::Worse)
4856 Result = ICS;
4857 }
4858
4859 // For an empty list, we won't have computed any conversion sequence.
4860 // Introduce the identity conversion sequence.
4861 if (From->getNumInits() == 0) {
4862 Result.setStandard();
4863 Result.Standard.setAsIdentityConversion();
4864 Result.Standard.setFromType(ToType);
4865 Result.Standard.setAllToTypes(ToType);
4866 }
4867
4868 Result.setStdInitializerListElement(toStdInitializerList);
4869 return Result;
4870 }
4871
4872 // C++14 [over.ics.list]p4:
4873 // C++11 [over.ics.list]p3:
4874 // Otherwise, if the parameter is a non-aggregate class X and overload
4875 // resolution chooses a single best constructor [...] the implicit
4876 // conversion sequence is a user-defined conversion sequence. If multiple
4877 // constructors are viable but none is better than the others, the
4878 // implicit conversion sequence is a user-defined conversion sequence.
4879 if (ToType->isRecordType() && !ToType->isAggregateType()) {
4880 // This function can deal with initializer lists.
4881 return TryUserDefinedConversion(S, From, ToType, SuppressUserConversions,
4882 /*AllowExplicit=*/false,
4883 InOverloadResolution, /*CStyle=*/false,
4884 AllowObjCWritebackConversion,
4885 /*AllowObjCConversionOnExplicit=*/false);
4886 }
4887
4888 // C++14 [over.ics.list]p5:
4889 // C++11 [over.ics.list]p4:
4890 // Otherwise, if the parameter has an aggregate type which can be
4891 // initialized from the initializer list [...] the implicit conversion
4892 // sequence is a user-defined conversion sequence.
4893 if (ToType->isAggregateType()) {
4894 // Type is an aggregate, argument is an init list. At this point it comes
4895 // down to checking whether the initialization works.
4896 // FIXME: Find out whether this parameter is consumed or not.
4897 // FIXME: Expose SemaInit's aggregate initialization code so that we don't
4898 // need to call into the initialization code here; overload resolution
4899 // should not be doing that.
4900 InitializedEntity Entity =
4901 InitializedEntity::InitializeParameter(S.Context, ToType,
4902 /*Consumed=*/false);
4903 if (S.CanPerformCopyInitialization(Entity, From)) {
4904 Result.setUserDefined();
4905 Result.UserDefined.Before.setAsIdentityConversion();
4906 // Initializer lists don't have a type.
4907 Result.UserDefined.Before.setFromType(QualType());
4908 Result.UserDefined.Before.setAllToTypes(QualType());
4909
4910 Result.UserDefined.After.setAsIdentityConversion();
4911 Result.UserDefined.After.setFromType(ToType);
4912 Result.UserDefined.After.setAllToTypes(ToType);
4913 Result.UserDefined.ConversionFunction = nullptr;
4914 }
4915 return Result;
4916 }
4917
4918 // C++14 [over.ics.list]p6:
4919 // C++11 [over.ics.list]p5:
4920 // Otherwise, if the parameter is a reference, see 13.3.3.1.4.
4921 if (ToType->isReferenceType()) {
4922 // The standard is notoriously unclear here, since 13.3.3.1.4 doesn't
4923 // mention initializer lists in any way. So we go by what list-
4924 // initialization would do and try to extrapolate from that.
4925
4926 QualType T1 = ToType->getAs<ReferenceType>()->getPointeeType();
4927
4928 // If the initializer list has a single element that is reference-related
4929 // to the parameter type, we initialize the reference from that.
4930 if (From->getNumInits() == 1) {
4931 Expr *Init = From->getInit(0);
4932
4933 QualType T2 = Init->getType();
4934
4935 // If the initializer is the address of an overloaded function, try
4936 // to resolve the overloaded function. If all goes well, T2 is the
4937 // type of the resulting function.
4938 if (S.Context.getCanonicalType(T2) == S.Context.OverloadTy) {
4939 DeclAccessPair Found;
4940 if (FunctionDecl *Fn = S.ResolveAddressOfOverloadedFunction(
4941 Init, ToType, false, Found))
4942 T2 = Fn->getType();
4943 }
4944
4945 // Compute some basic properties of the types and the initializer.
4946 bool dummy1 = false;
4947 bool dummy2 = false;
4948 bool dummy3 = false;
4949 Sema::ReferenceCompareResult RefRelationship =
4950 S.CompareReferenceRelationship(From->getBeginLoc(), T1, T2, dummy1,
4951 dummy2, dummy3);
4952
4953 if (RefRelationship >= Sema::Ref_Related) {
4954 return TryReferenceInit(S, Init, ToType, /*FIXME*/ From->getBeginLoc(),
4955 SuppressUserConversions,
4956 /*AllowExplicit=*/false);
4957 }
4958 }
4959
4960 // Otherwise, we bind the reference to a temporary created from the
4961 // initializer list.
4962 Result = TryListConversion(S, From, T1, SuppressUserConversions,
4963 InOverloadResolution,
4964 AllowObjCWritebackConversion);
4965 if (Result.isFailure())
4966 return Result;
4967 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.\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/Sema/SemaOverload.cpp"
, 4968, __PRETTY_FUNCTION__))
4968 "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.\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/Sema/SemaOverload.cpp"
, 4968, __PRETTY_FUNCTION__))
;
4969
4970 // Can we even bind to a temporary?
4971 if (ToType->isRValueReferenceType() ||
4972 (T1.isConstQualified() && !T1.isVolatileQualified())) {
4973 StandardConversionSequence &SCS = Result.isStandard() ? Result.Standard :
4974 Result.UserDefined.After;
4975 SCS.ReferenceBinding = true;
4976 SCS.IsLvalueReference = ToType->isLValueReferenceType();
4977 SCS.BindsToRvalue = true;
4978 SCS.BindsToFunctionLvalue = false;
4979 SCS.BindsImplicitObjectArgumentWithoutRefQualifier = false;
4980 SCS.ObjCLifetimeConversionBinding = false;
4981 } else
4982 Result.setBad(BadConversionSequence::lvalue_ref_to_rvalue,
4983 From, ToType);
4984 return Result;
4985 }
4986
4987 // C++14 [over.ics.list]p7:
4988 // C++11 [over.ics.list]p6:
4989 // Otherwise, if the parameter type is not a class:
4990 if (!ToType->isRecordType()) {
4991 // - if the initializer list has one element that is not itself an
4992 // initializer list, the implicit conversion sequence is the one
4993 // required to convert the element to the parameter type.
4994 unsigned NumInits = From->getNumInits();
4995 if (NumInits == 1 && !isa<InitListExpr>(From->getInit(0)))
4996 Result = TryCopyInitialization(S, From->getInit(0), ToType,
4997 SuppressUserConversions,
4998 InOverloadResolution,
4999 AllowObjCWritebackConversion);
5000 // - if the initializer list has no elements, the implicit conversion
5001 // sequence is the identity conversion.
5002 else if (NumInits == 0) {
5003 Result.setStandard();
5004 Result.Standard.setAsIdentityConversion();
5005 Result.Standard.setFromType(ToType);
5006 Result.Standard.setAllToTypes(ToType);
5007 }
5008 return Result;
5009 }
5010
5011 // C++14 [over.ics.list]p8:
5012 // C++11 [over.ics.list]p7:
5013 // In all cases other than those enumerated above, no conversion is possible
5014 return Result;
5015}
5016
5017/// TryCopyInitialization - Try to copy-initialize a value of type
5018/// ToType from the expression From. Return the implicit conversion
5019/// sequence required to pass this argument, which may be a bad
5020/// conversion sequence (meaning that the argument cannot be passed to
5021/// a parameter of this type). If @p SuppressUserConversions, then we
5022/// do not permit any user-defined conversion sequences.
5023static ImplicitConversionSequence
5024TryCopyInitialization(Sema &S, Expr *From, QualType ToType,
5025 bool SuppressUserConversions,
5026 bool InOverloadResolution,
5027 bool AllowObjCWritebackConversion,
5028 bool AllowExplicit) {
5029 if (InitListExpr *FromInitList = dyn_cast<InitListExpr>(From))
5030 return TryListConversion(S, FromInitList, ToType, SuppressUserConversions,
5031 InOverloadResolution,AllowObjCWritebackConversion);
5032
5033 if (ToType->isReferenceType())
5034 return TryReferenceInit(S, From, ToType,
5035 /*FIXME:*/ From->getBeginLoc(),
5036 SuppressUserConversions, AllowExplicit);
5037
5038 return TryImplicitConversion(S, From, ToType,
5039 SuppressUserConversions,
5040 /*AllowExplicit=*/false,
5041 InOverloadResolution,
5042 /*CStyle=*/false,
5043 AllowObjCWritebackConversion,
5044 /*AllowObjCConversionOnExplicit=*/false);
5045}
5046
5047static bool TryCopyInitialization(const CanQualType FromQTy,
5048 const CanQualType ToQTy,
5049 Sema &S,
5050 SourceLocation Loc,
5051 ExprValueKind FromVK) {
5052 OpaqueValueExpr TmpExpr(Loc, FromQTy, FromVK);
5053 ImplicitConversionSequence ICS =
5054 TryCopyInitialization(S, &TmpExpr, ToQTy, true, true, false);
5055
5056 return !ICS.isBad();
5057}
5058
5059/// TryObjectArgumentInitialization - Try to initialize the object
5060/// parameter of the given member function (@c Method) from the
5061/// expression @p From.
5062static ImplicitConversionSequence
5063TryObjectArgumentInitialization(Sema &S, SourceLocation Loc, QualType FromType,
5064 Expr::Classification FromClassification,
5065 CXXMethodDecl *Method,
5066 CXXRecordDecl *ActingContext) {
5067 QualType ClassType = S.Context.getTypeDeclType(ActingContext);
5068 // [class.dtor]p2: A destructor can be invoked for a const, volatile or
5069 // const volatile object.
5070 Qualifiers Quals;
5071 if (isa<CXXDestructorDecl>(Method)) {
5072 Quals.addConst();
5073 Quals.addVolatile();
5074 } else {
5075 Quals = Method->getTypeQualifiers();
5076 }
5077
5078 QualType ImplicitParamType = S.Context.getQualifiedType(ClassType, Quals);
5079
5080 // Set up the conversion sequence as a "bad" conversion, to allow us
5081 // to exit early.
5082 ImplicitConversionSequence ICS;
5083
5084 // We need to have an object of class type.
5085 if (const PointerType *PT = FromType->getAs<PointerType>()) {
5086 FromType = PT->getPointeeType();
5087
5088 // When we had a pointer, it's implicitly dereferenced, so we
5089 // better have an lvalue.
5090 assert(FromClassification.isLValue())((FromClassification.isLValue()) ? static_cast<void> (0
) : __assert_fail ("FromClassification.isLValue()", "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/Sema/SemaOverload.cpp"
, 5090, __PRETTY_FUNCTION__))
;
5091 }
5092
5093 assert(FromType->isRecordType())((FromType->isRecordType()) ? static_cast<void> (0) :
__assert_fail ("FromType->isRecordType()", "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/Sema/SemaOverload.cpp"
, 5093, __PRETTY_FUNCTION__))
;
5094
5095 // C++0x [over.match.funcs]p4:
5096 // For non-static member functions, the type of the implicit object
5097 // parameter is
5098 //
5099 // - "lvalue reference to cv X" for functions declared without a
5100 // ref-qualifier or with the & ref-qualifier
5101 // - "rvalue reference to cv X" for functions declared with the &&
5102 // ref-qualifier
5103 //
5104 // where X is the class of which the function is a member and cv is the
5105 // cv-qualification on the member function declaration.
5106 //
5107 // However, when finding an implicit conversion sequence for the argument, we
5108 // are not allowed to perform user-defined conversions
5109 // (C++ [over.match.funcs]p5). We perform a simplified version of
5110 // reference binding here, that allows class rvalues to bind to
5111 // non-constant references.
5112
5113 // First check the qualifiers.
5114 QualType FromTypeCanon = S.Context.getCanonicalType(FromType);
5115 if (ImplicitParamType.getCVRQualifiers()
5116 != FromTypeCanon.getLocalCVRQualifiers() &&
5117 !ImplicitParamType.isAtLeastAsQualifiedAs(FromTypeCanon)) {
5118 ICS.setBad(BadConversionSequence::bad_qualifiers,
5119 FromType, ImplicitParamType);
5120 return ICS;
5121 }
5122
5123 // Check that we have either the same type or a derived type. It
5124 // affects the conversion rank.
5125 QualType ClassTypeCanon = S.Context.getCanonicalType(ClassType);
5126 ImplicitConversionKind SecondKind;
5127 if (ClassTypeCanon == FromTypeCanon.getLocalUnqualifiedType()) {
5128 SecondKind = ICK_Identity;
5129 } else if (S.IsDerivedFrom(Loc, FromType, ClassType))
5130 SecondKind = ICK_Derived_To_Base;
5131 else {
5132 ICS.setBad(BadConversionSequence::unrelated_class,
5133 FromType, ImplicitParamType);
5134 return ICS;
5135 }
5136
5137 // Check the ref-qualifier.
5138 switch (Method->getRefQualifier()) {
5139 case RQ_None:
5140 // Do nothing; we don't care about lvalueness or rvalueness.
5141 break;
5142
5143 case RQ_LValue:
5144 if (!FromClassification.isLValue() && !Quals.hasOnlyConst()) {
5145 // non-const lvalue reference cannot bind to an rvalue
5146 ICS.setBad(BadConversionSequence::lvalue_ref_to_rvalue, FromType,
5147 ImplicitParamType);
5148 return ICS;
5149 }
5150 break;
5151
5152 case RQ_RValue:
5153 if (!FromClassification.isRValue()) {
5154 // rvalue reference cannot bind to an lvalue
5155 ICS.setBad(BadConversionSequence::rvalue_ref_to_lvalue, FromType,
5156 ImplicitParamType);
5157 return ICS;
5158 }
5159 break;
5160 }
5161
5162 // Success. Mark this as a reference binding.
5163 ICS.setStandard();
5164 ICS.Standard.setAsIdentityConversion();
5165 ICS.Standard.Second = SecondKind;
5166 ICS.Standard.setFromType(FromType);
5167 ICS.Standard.setAllToTypes(ImplicitParamType);
5168 ICS.Standard.ReferenceBinding = true;
5169 ICS.Standard.DirectBinding = true;
5170 ICS.Standard.IsLvalueReference = Method->getRefQualifier() != RQ_RValue;
5171 ICS.Standard.BindsToFunctionLvalue = false;
5172 ICS.Standard.BindsToRvalue = FromClassification.isRValue();
5173 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier
5174 = (Method->getRefQualifier() == RQ_None);
5175 return ICS;
5176}
5177
5178/// PerformObjectArgumentInitialization - Perform initialization of
5179/// the implicit object parameter for the given Method with the given
5180/// expression.
5181ExprResult
5182Sema::PerformObjectArgumentInitialization(Expr *From,
5183 NestedNameSpecifier *Qualifier,
5184 NamedDecl *FoundDecl,
5185 CXXMethodDecl *Method) {
5186 QualType FromRecordType, DestType;
5187 QualType ImplicitParamRecordType =
5188 Method->getThisType(Context)->getAs<PointerType>()->getPointeeType();
5189
5190 Expr::Classification FromClassification;
5191 if (const PointerType *PT = From->getType()->getAs<PointerType>()) {
5192 FromRecordType = PT->getPointeeType();
5193 DestType = Method->getThisType(Context);
5194 FromClassification = Expr::Classification::makeSimpleLValue();
5195 } else {
5196 FromRecordType = From->getType();
5197 DestType = ImplicitParamRecordType;
5198 FromClassification = From->Classify(Context);
5199
5200 // When performing member access on an rvalue, materialize a temporary.
5201 if (From->isRValue()) {
5202 From = CreateMaterializeTemporaryExpr(FromRecordType, From,
5203 Method->getRefQualifier() !=
5204 RefQualifierKind::RQ_RValue);
5205 }
5206 }
5207
5208 // Note that we always use the true parent context when performing
5209 // the actual argument initialization.
5210 ImplicitConversionSequence ICS = TryObjectArgumentInitialization(
5211 *this, From->getBeginLoc(), From->getType(), FromClassification, Method,
5212 Method->getParent());
5213 if (ICS.isBad()) {
5214 switch (ICS.Bad.Kind) {
5215 case BadConversionSequence::bad_qualifiers: {
5216 Qualifiers FromQs = FromRecordType.getQualifiers();
5217 Qualifiers ToQs = DestType.getQualifiers();
5218 unsigned CVR = FromQs.getCVRQualifiers() & ~ToQs.getCVRQualifiers();
5219 if (CVR) {
5220 Diag(From->getBeginLoc(), diag::err_member_function_call_bad_cvr)
5221 << Method->getDeclName() << FromRecordType << (CVR - 1)
5222 << From->getSourceRange();
5223 Diag(Method->getLocation(), diag::note_previous_decl)
5224 << Method->getDeclName();
5225 return ExprError();
5226 }
5227 break;
5228 }
5229
5230 case BadConversionSequence::lvalue_ref_to_rvalue:
5231 case BadConversionSequence::rvalue_ref_to_lvalue: {
5232 bool IsRValueQualified =
5233 Method->getRefQualifier() == RefQualifierKind::RQ_RValue;
5234 Diag(From->getBeginLoc(), diag::err_member_function_call_bad_ref)
5235 << Method->getDeclName() << FromClassification.isRValue()
5236 << IsRValueQualified;
5237 Diag(Method->getLocation(), diag::note_previous_decl)
5238 << Method->getDeclName();
5239 return ExprError();
5240 }
5241
5242 case BadConversionSequence::no_conversion:
5243 case BadConversionSequence::unrelated_class:
5244 break;
5245 }
5246
5247 return Diag(From->getBeginLoc(), diag::err_member_function_call_bad_type)
5248 << ImplicitParamRecordType << FromRecordType
5249 << From->getSourceRange();
5250 }
5251
5252 if (ICS.Standard.Second == ICK_Derived_To_Base) {
5253 ExprResult FromRes =
5254 PerformObjectMemberConversion(From, Qualifier, FoundDecl, Method);
5255 if (FromRes.isInvalid())
5256 return ExprError();
5257 From = FromRes.get();
5258 }
5259
5260 if (!Context.hasSameType(From->getType(), DestType)) {
5261 if (From->getType().getAddressSpace() != DestType.getAddressSpace())
5262 From = ImpCastExprToType(From, DestType, CK_AddressSpaceConversion,
5263 From->getValueKind()).get();
5264 else
5265 From = ImpCastExprToType(From, DestType, CK_NoOp,
5266 From->getValueKind()).get();
5267 }
5268 return From;
5269}
5270
5271/// TryContextuallyConvertToBool - Attempt to contextually convert the
5272/// expression From to bool (C++0x [conv]p3).
5273static ImplicitConversionSequence
5274TryContextuallyConvertToBool(Sema &S, Expr *From) {
5275 return TryImplicitConversion(S, From, S.Context.BoolTy,
5276 /*SuppressUserConversions=*/false,
5277 /*AllowExplicit=*/true,
5278 /*InOverloadResolution=*/false,
5279 /*CStyle=*/false,
5280 /*AllowObjCWritebackConversion=*/false,
5281 /*AllowObjCConversionOnExplicit=*/false);
5282}
5283
5284/// PerformContextuallyConvertToBool - Perform a contextual conversion
5285/// of the expression From to bool (C++0x [conv]p3).
5286ExprResult Sema::PerformContextuallyConvertToBool(Expr *From) {
5287 if (checkPlaceholderForOverload(*this, From))
5288 return ExprError();
5289
5290 ImplicitConversionSequence ICS = TryContextuallyConvertToBool(*this, From);
5291 if (!ICS.isBad())
5292 return PerformImplicitConversion(From, Context.BoolTy, ICS, AA_Converting);
5293
5294 if (!DiagnoseMultipleUserDefinedConversion(From, Context.BoolTy))
5295 return Diag(From->getBeginLoc(), diag::err_typecheck_bool_condition)
5296 << From->getType() << From->getSourceRange();
5297 return ExprError();
5298}
5299
5300/// Check that the specified conversion is permitted in a converted constant
5301/// expression, according to C++11 [expr.const]p3. Return true if the conversion
5302/// is acceptable.
5303static bool CheckConvertedConstantConversions(Sema &S,
5304 StandardConversionSequence &SCS) {
5305 // Since we know that the target type is an integral or unscoped enumeration
5306 // type, most conversion kinds are impossible. All possible First and Third
5307 // conversions are fine.
5308 switch (SCS.Second) {
5309 case ICK_Identity:
5310 case ICK_Function_Conversion:
5311 case ICK_Integral_Promotion:
5312 case ICK_Integral_Conversion: // Narrowing conversions are checked elsewhere.
5313 case ICK_Zero_Queue_Conversion:
5314 return true;
5315
5316 case ICK_Boolean_Conversion:
5317 // Conversion from an integral or unscoped enumeration type to bool is
5318 // classified as ICK_Boolean_Conversion, but it's also arguably an integral
5319 // conversion, so we allow it in a converted constant expression.
5320 //
5321 // FIXME: Per core issue 1407, we should not allow this, but that breaks
5322 // a lot of popular code. We should at least add a warning for this
5323 // (non-conforming) extension.
5324 return SCS.getFromType()->isIntegralOrUnscopedEnumerationType() &&
5325 SCS.getToType(2)->isBooleanType();
5326
5327 case ICK_Pointer_Conversion:
5328 case ICK_Pointer_Member:
5329 // C++1z: null pointer conversions and null member pointer conversions are
5330 // only permitted if the source type is std::nullptr_t.
5331 return SCS.getFromType()->isNullPtrType();
5332
5333 case ICK_Floating_Promotion:
5334 case ICK_Complex_Promotion:
5335 case ICK_Floating_Conversion:
5336 case ICK_Complex_Conversion:
5337 case ICK_Floating_Integral:
5338 case ICK_Compatible_Conversion:
5339 case ICK_Derived_To_Base:
5340 case ICK_Vector_Conversion:
5341 case ICK_Vector_Splat:
5342 case ICK_Complex_Real:
5343 case ICK_Block_Pointer_Conversion:
5344 case ICK_TransparentUnionConversion:
5345 case ICK_Writeback_Conversion:
5346 case ICK_Zero_Event_Conversion:
5347 case ICK_C_Only_Conversion:
5348 case ICK_Incompatible_Pointer_Conversion:
5349 return false;
5350
5351 case ICK_Lvalue_To_Rvalue:
5352 case ICK_Array_To_Pointer:
5353 case ICK_Function_To_Pointer:
5354 llvm_unreachable("found a first conversion kind in Second")::llvm::llvm_unreachable_internal("found a first conversion kind in Second"
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/Sema/SemaOverload.cpp"
, 5354)
;
5355
5356 case ICK_Qualification:
5357 llvm_unreachable("found a third conversion kind in Second")::llvm::llvm_unreachable_internal("found a third conversion kind in Second"
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/Sema/SemaOverload.cpp"
, 5357)
;
5358
5359 case ICK_Num_Conversion_Kinds:
5360 break;
5361 }
5362
5363 llvm_unreachable("unknown conversion kind")::llvm::llvm_unreachable_internal("unknown conversion kind", "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/Sema/SemaOverload.cpp"
, 5363)
;
5364}
5365
5366/// CheckConvertedConstantExpression - Check that the expression From is a
5367/// converted constant expression of type T, perform the conversion and produce
5368/// the converted expression, per C++11 [expr.const]p3.
5369static ExprResult CheckConvertedConstantExpression(Sema &S, Expr *From,
5370 QualType T, APValue &Value,
5371 Sema::CCEKind CCE,
5372 bool RequireInt) {
5373 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\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/Sema/SemaOverload.cpp"
, 5374, __PRETTY_FUNCTION__))
5374 "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\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/Sema/SemaOverload.cpp"
, 5374, __PRETTY_FUNCTION__))
;
5375
5376 if (checkPlaceholderForOverload(S, From))
5377 return ExprError();
5378
5379 // C++1z [expr.const]p3:
5380 // A converted constant expression of type T is an expression,
5381 // implicitly converted to type T, where the converted
5382 // expression is a constant expression and the implicit conversion
5383 // sequence contains only [... list of conversions ...].
5384 // C++1z [stmt.if]p2:
5385 // If the if statement is of the form if constexpr, the value of the
5386 // condition shall be a contextually converted constant expression of type
5387 // bool.
5388 ImplicitConversionSequence ICS =
5389 CCE == Sema::CCEK_ConstexprIf
5390 ? TryContextuallyConvertToBool(S, From)
5391 : TryCopyInitialization(S, From, T,
5392 /*SuppressUserConversions=*/false,
5393 /*InOverloadResolution=*/false,
5394 /*AllowObjcWritebackConversion=*/false,
5395 /*AllowExplicit=*/false);
5396 StandardConversionSequence *SCS = nullptr;
5397 switch (ICS.getKind()) {
5398 case ImplicitConversionSequence::StandardConversion:
5399 SCS = &ICS.Standard;
5400 break;
5401 case ImplicitConversionSequence::UserDefinedConversion:
5402 // We are converting to a non-class type, so the Before sequence
5403 // must be trivial.
5404 SCS = &ICS.UserDefined.After;
5405 break;
5406 case ImplicitConversionSequence::AmbiguousConversion:
5407 case ImplicitConversionSequence::BadConversion:
5408 if (!S.DiagnoseMultipleUserDefinedConversion(From, T))
5409 return S.Diag(From->getBeginLoc(),
5410 diag::err_typecheck_converted_constant_expression)
5411 << From->getType() << From->getSourceRange() << T;
5412 return ExprError();
5413
5414 case ImplicitConversionSequence::EllipsisConversion:
5415 llvm_unreachable("ellipsis conversion in converted constant expression")::llvm::llvm_unreachable_internal("ellipsis conversion in converted constant expression"
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/Sema/SemaOverload.cpp"
, 5415)
;
5416 }
5417
5418 // Check that we would only use permitted conversions.
5419 if (!CheckConvertedConstantConversions(S, *SCS)) {
5420 return S.Diag(From->getBeginLoc(),
5421 diag::err_typecheck_converted_constant_expression_disallowed)
5422 << From->getType() << From->getSourceRange() << T;
5423 }
5424 // [...] and where the reference binding (if any) binds directly.
5425 if (SCS->ReferenceBinding && !SCS->DirectBinding) {
5426 return S.Diag(From->getBeginLoc(),
5427 diag::err_typecheck_converted_constant_expression_indirect)
5428 << From->getType() << From->getSourceRange() << T;
5429 }
5430
5431 ExprResult Result =
5432 S.PerformImplicitConversion(From, T, ICS, Sema::AA_Converting);
5433 if (Result.isInvalid())
5434 return Result;
5435
5436 // Check for a narrowing implicit conversion.
5437 APValue PreNarrowingValue;
5438 QualType PreNarrowingType;
5439 switch (SCS->getNarrowingKind(S.Context, Result.get(), PreNarrowingValue,
5440 PreNarrowingType)) {
5441 case NK_Dependent_Narrowing:
5442 // Implicit conversion to a narrower type, but the expression is
5443 // value-dependent so we can't tell whether it's actually narrowing.
5444 case NK_Variable_Narrowing:
5445 // Implicit conversion to a narrower type, and the value is not a constant
5446 // expression. We'll diagnose this in a moment.
5447 case NK_Not_Narrowing:
5448 break;
5449
5450 case NK_Constant_Narrowing:
5451 S.Diag(From->getBeginLoc(), diag::ext_cce_narrowing)
5452 << CCE << /*Constant*/ 1
5453 << PreNarrowingValue.getAsString(S.Context, PreNarrowingType) << T;
5454 break;
5455
5456 case NK_Type_Narrowing:
5457 S.Diag(From->getBeginLoc(), diag::ext_cce_narrowing)
5458 << CCE << /*Constant*/ 0 << From->getType() << T;
5459 break;
5460 }
5461
5462 if (Result.get()->isValueDependent()) {
5463 Value = APValue();
5464 return Result;
5465 }
5466
5467 // Check the expression is a constant expression.
5468 SmallVector<PartialDiagnosticAt, 8> Notes;
5469 Expr::EvalResult Eval;
5470 Eval.Diag = &Notes;
5471 Expr::ConstExprUsage Usage = CCE == Sema::CCEK_TemplateArg
5472 ? Expr::EvaluateForMangling
5473 : Expr::EvaluateForCodeGen;
5474
5475 if (!Result.get()->EvaluateAsConstantExpr(Eval, Usage, S.Context) ||
5476 (RequireInt && !Eval.Val.isInt())) {
5477 // The expression can't be folded, so we can't keep it at this position in
5478 // the AST.
5479 Result = ExprError();
5480 } else {
5481 Value = Eval.Val;
5482
5483 if (Notes.empty()) {
5484 // It's a constant expression.
5485 return ConstantExpr::Create(S.Context, Result.get());
5486 }
5487 }
5488
5489 // It's not a constant expression. Produce an appropriate diagnostic.
5490 if (Notes.size() == 1 &&
5491 Notes[0].second.getDiagID() == diag::note_invalid_subexpr_in_const_expr)
5492 S.Diag(Notes[0].first, diag::err_expr_not_cce) << CCE;
5493 else {
5494 S.Diag(From->getBeginLoc(), diag::err_expr_not_cce)
5495 << CCE << From->getSourceRange();
5496 for (unsigned I = 0; I < Notes.size(); ++I)
5497 S.Diag(Notes[I].first, Notes[I].second);
5498 }
5499 return ExprError();
5500}
5501
5502ExprResult Sema::CheckConvertedConstantExpression(Expr *From, QualType T,
5503 APValue &Value, CCEKind CCE) {
5504 return ::CheckConvertedConstantExpression(*this, From, T, Value, CCE, false);
5505}
5506
5507ExprResult Sema::CheckConvertedConstantExpression(Expr *From, QualType T,
5508 llvm::APSInt &Value,
5509 CCEKind CCE) {
5510 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\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/Sema/SemaOverload.cpp"
, 5510, __PRETTY_FUNCTION__))
;
5511
5512 APValue V;
5513 auto R = ::CheckConvertedConstantExpression(*this, From, T, V, CCE, true);
5514 if (!R.isInvalid() && !R.get()->isValueDependent())
5515 Value = V.getInt();
5516 return R;
5517}
5518
5519
5520/// dropPointerConversions - If the given standard conversion sequence
5521/// involves any pointer conversions, remove them. This may change
5522/// the result type of the conversion sequence.
5523static void dropPointerConversion(StandardConversionSequence &SCS) {
5524 if (SCS.Second == ICK_Pointer_Conversion) {
5525 SCS.Second = ICK_Identity;
5526 SCS.Third = ICK_Identity;
5527 SCS.ToTypePtrs[2] = SCS.ToTypePtrs[1] = SCS.ToTypePtrs[0];
5528 }
5529}
5530
5531/// TryContextuallyConvertToObjCPointer - Attempt to contextually
5532/// convert the expression From to an Objective-C pointer type.
5533static ImplicitConversionSequence
5534TryContextuallyConvertToObjCPointer(Sema &S, Expr *From) {
5535 // Do an implicit conversion to 'id'.
5536 QualType Ty = S.Context.getObjCIdType();
5537 ImplicitConversionSequence ICS
5538 = TryImplicitConversion(S, From, Ty,
5539 // FIXME: Are these flags correct?
5540 /*SuppressUserConversions=*/false,
5541 /*AllowExplicit=*/true,
5542 /*InOverloadResolution=*/false,
5543 /*CStyle=*/false,
5544 /*AllowObjCWritebackConversion=*/false,
5545 /*AllowObjCConversionOnExplicit=*/true);
5546
5547 // Strip off any final conversions to 'id'.
5548 switch (ICS.getKind()) {
5549 case ImplicitConversionSequence::BadConversion:
5550 case ImplicitConversionSequence::AmbiguousConversion:
5551 case ImplicitConversionSequence::EllipsisConversion:
5552 break;
5553
5554 case ImplicitConversionSequence::UserDefinedConversion:
5555 dropPointerConversion(ICS.UserDefined.After);
5556 break;
5557
5558 case ImplicitConversionSequence::StandardConversion:
5559 dropPointerConversion(ICS.Standard);
5560 break;
5561 }
5562
5563 return ICS;
5564}
5565
5566/// PerformContextuallyConvertToObjCPointer - Perform a contextual
5567/// conversion of the expression From to an Objective-C pointer type.
5568/// Returns a valid but null ExprResult if no conversion sequence exists.
5569ExprResult Sema::PerformContextuallyConvertToObjCPointer(Expr *From) {
5570 if (checkPlaceholderForOverload(*this, From))
5571 return ExprError();
5572
5573 QualType Ty = Context.getObjCIdType();
5574 ImplicitConversionSequence ICS =
5575 TryContextuallyConvertToObjCPointer(*this, From);
5576 if (!ICS.isBad())
5577 return PerformImplicitConversion(From, Ty, ICS, AA_Converting);
5578 return ExprResult();
5579}
5580
5581/// Determine whether the provided type is an integral type, or an enumeration
5582/// type of a permitted flavor.
5583bool Sema::ICEConvertDiagnoser::match(QualType T) {
5584 return AllowScopedEnumerations ? T->isIntegralOrEnumerationType()
5585 : T->isIntegralOrUnscopedEnumerationType();
5586}
5587
5588static ExprResult
5589diagnoseAmbiguousConversion(Sema &SemaRef, SourceLocation Loc, Expr *From,
5590 Sema::ContextualImplicitConverter &Converter,
5591 QualType T, UnresolvedSetImpl &ViableConversions) {
5592
5593 if (Converter.Suppress)
5594 return ExprError();
5595
5596 Converter.diagnoseAmbiguous(SemaRef, Loc, T) << From->getSourceRange();
5597 for (unsigned I = 0, N = ViableConversions.size(); I != N; ++I) {
5598 CXXConversionDecl *Conv =
5599 cast<CXXConversionDecl>(ViableConversions[I]->getUnderlyingDecl());
5600 QualType ConvTy = Conv->getConversionType().getNonReferenceType();
5601 Converter.noteAmbiguous(SemaRef, Conv, ConvTy);
5602 }
5603 return From;
5604}
5605
5606static bool
5607diagnoseNoViableConversion(Sema &SemaRef, SourceLocation Loc, Expr *&From,
5608 Sema::ContextualImplicitConverter &Converter,
5609 QualType T, bool HadMultipleCandidates,
5610 UnresolvedSetImpl &ExplicitConversions) {
5611 if (ExplicitConversions.size() == 1 && !Converter.Suppress) {
5612 DeclAccessPair Found = ExplicitConversions[0];
5613 CXXConversionDecl *Conversion =
5614 cast<CXXConversionDecl>(Found->getUnderlyingDecl());
5615
5616 // The user probably meant to invoke the given explicit
5617 // conversion; use it.
5618 QualType ConvTy = Conversion->getConversionType().getNonReferenceType();
5619 std::string TypeStr;
5620 ConvTy.getAsStringInternal(TypeStr, SemaRef.getPrintingPolicy());
5621
5622 Converter.diagnoseExplicitConv(SemaRef, Loc, T, ConvTy)
5623 << FixItHint::CreateInsertion(From->getBeginLoc(),
5624 "static_cast<" + TypeStr + ">(")
5625 << FixItHint::CreateInsertion(
5626 SemaRef.getLocForEndOfToken(From->getEndLoc()), ")");
5627 Converter.noteExplicitConv(SemaRef, Conversion, ConvTy);
5628
5629 // If we aren't in a SFINAE context, build a call to the
5630 // explicit conversion function.
5631 if (SemaRef.isSFINAEContext())
5632 return true;
5633
5634 SemaRef.CheckMemberOperatorAccess(From->getExprLoc(), From, nullptr, Found);
5635 ExprResult Result = SemaRef.BuildCXXMemberCallExpr(From, Found, Conversion,
5636 HadMultipleCandidates);
5637 if (Result.isInvalid())
5638 return true;
5639 // Record usage of conversion in an implicit cast.
5640 From = ImplicitCastExpr::Create(SemaRef.Context, Result.get()->getType(),
5641 CK_UserDefinedConversion, Result.get(),
5642 nullptr, Result.get()->getValueKind());
5643 }
5644 return false;
5645}
5646
5647static bool recordConversion(Sema &SemaRef, SourceLocation Loc, Expr *&From,
5648 Sema::ContextualImplicitConverter &Converter,
5649 QualType T, bool HadMultipleCandidates,
5650 DeclAccessPair &Found) {
5651 CXXConversionDecl *Conversion =
5652 cast<CXXConversionDecl>(Found->getUnderlyingDecl());
5653 SemaRef.CheckMemberOperatorAccess(From->getExprLoc(), From, nullptr, Found);
5654
5655 QualType ToType = Conversion->getConversionType().getNonReferenceType();
5656 if (!Converter.SuppressConversion) {
5657 if (SemaRef.isSFINAEContext())
5658 return true;
5659
5660 Converter.diagnoseConversion(SemaRef, Loc, T, ToType)
5661 << From->getSourceRange();
5662 }
5663
5664 ExprResult Result = SemaRef.BuildCXXMemberCallExpr(From, Found, Conversion,
5665 HadMultipleCandidates);
5666 if (Result.isInvalid())
5667 return true;
5668 // Record usage of conversion in an implicit cast.
5669 From = ImplicitCastExpr::Create(SemaRef.Context, Result.get()->getType(),
5670 CK_UserDefinedConversion, Result.get(),
5671 nullptr, Result.get()->getValueKind());
5672 return false;
5673}
5674
5675static ExprResult finishContextualImplicitConversion(
5676 Sema &SemaRef, SourceLocation Loc, Expr *From,
5677 Sema::ContextualImplicitConverter &Converter) {
5678 if (!Converter.match(From->getType()) && !Converter.Suppress)
5679 Converter.diagnoseNoMatch(SemaRef, Loc, From->getType())
5680 << From->getSourceRange();
5681
5682 return SemaRef.DefaultLvalueConversion(From);
5683}
5684
5685static void
5686collectViableConversionCandidates(Sema &SemaRef, Expr *From, QualType ToType,
5687 UnresolvedSetImpl &ViableConversions,
5688 OverloadCandidateSet &CandidateSet) {
5689 for (unsigned I = 0, N = ViableConversions.size(); I != N; ++I) {
5690 DeclAccessPair FoundDecl = ViableConversions[I];
5691 NamedDecl *D = FoundDecl.getDecl();
5692 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext());
5693 if (isa<UsingShadowDecl>(D))
5694 D = cast<UsingShadowDecl>(D)->getTargetDecl();
5695
5696 CXXConversionDecl *Conv;
5697 FunctionTemplateDecl *ConvTemplate;
5698 if ((ConvTemplate = dyn_cast<FunctionTemplateDecl>(D)))
5699 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl());
5700 else
5701 Conv = cast<CXXConversionDecl>(D);
5702
5703 if (ConvTemplate)
5704 SemaRef.AddTemplateConversionCandidate(
5705 ConvTemplate, FoundDecl, ActingContext, From, ToType, CandidateSet,
5706 /*AllowObjCConversionOnExplicit=*/false);
5707 else
5708 SemaRef.AddConversionCandidate(Conv, FoundDecl, ActingContext, From,
5709 ToType, CandidateSet,
5710 /*AllowObjCConversionOnExplicit=*/false);
5711 }
5712}
5713
5714/// Attempt to convert the given expression to a type which is accepted
5715/// by the given converter.
5716///
5717/// This routine will attempt to convert an expression of class type to a
5718/// type accepted by the specified converter. In C++11 and before, the class
5719/// must have a single non-explicit conversion function converting to a matching
5720/// type. In C++1y, there can be multiple such conversion functions, but only
5721/// one target type.
5722///
5723/// \param Loc The source location of the construct that requires the
5724/// conversion.
5725///
5726/// \param From The expression we're converting from.
5727///
5728/// \param Converter Used to control and diagnose the conversion process.
5729///
5730/// \returns The expression, converted to an integral or enumeration type if
5731/// successful.
5732ExprResult Sema::PerformContextualImplicitConversion(
5733 SourceLocation Loc, Expr *From, ContextualImplicitConverter &Converter) {
5734 // We can't perform any more checking for type-dependent expressions.
5735 if (From->isTypeDependent())
5736 return From;
5737
5738 // Process placeholders immediately.
5739 if (From->hasPlaceholderType()) {
5740 ExprResult result = CheckPlaceholderExpr(From);
5741 if (result.isInvalid())
5742 return result;
5743 From = result.get();
5744 }
5745
5746 // If the expression already has a matching type, we're golden.
5747 QualType T = From->getType();
5748 if (Converter.match(T))
5749 return DefaultLvalueConversion(From);
5750
5751 // FIXME: Check for missing '()' if T is a function type?
5752
5753 // We can only perform contextual implicit conversions on objects of class
5754 // type.
5755 const RecordType *RecordTy = T->getAs<RecordType>();
5756 if (!RecordTy || !getLangOpts().CPlusPlus) {
5757 if (!Converter.Suppress)
5758 Converter.diagnoseNoMatch(*this, Loc, T) << From->getSourceRange();
5759 return From;
5760 }
5761
5762 // We must have a complete class type.
5763 struct TypeDiagnoserPartialDiag : TypeDiagnoser {
5764 ContextualImplicitConverter &Converter;
5765 Expr *From;
5766
5767 TypeDiagnoserPartialDiag(ContextualImplicitConverter &Converter, Expr *From)
5768 : Converter(Converter), From(From) {}
5769
5770 void diagnose(Sema &S, SourceLocation Loc, QualType T) override {
5771 Converter.diagnoseIncomplete(S, Loc, T) << From->getSourceRange();
5772 }
5773 } IncompleteDiagnoser(Converter, From);
5774
5775 if (Converter.Suppress ? !isCompleteType(Loc, T)
5776 : RequireCompleteType(Loc, T, IncompleteDiagnoser))
5777 return From;
5778
5779 // Look for a conversion to an integral or enumeration type.
5780 UnresolvedSet<4>
5781 ViableConversions; // These are *potentially* viable in C++1y.
5782 UnresolvedSet<4> ExplicitConversions;
5783 const auto &Conversions =
5784 cast<CXXRecordDecl>(RecordTy->getDecl())->getVisibleConversionFunctions();
5785
5786 bool HadMultipleCandidates =
5787 (std::distance(Conversions.begin(), Conversions.end()) > 1);
5788
5789 // To check that there is only one target type, in C++1y:
5790 QualType ToType;
5791 bool HasUniqueTargetType = true;
5792
5793 // Collect explicit or viable (potentially in C++1y) conversions.
5794 for (auto I = Conversions.begin(), E = Conversions.end(); I != E; ++I) {
5795 NamedDecl *D = (*I)->getUnderlyingDecl();
5796 CXXConversionDecl *Conversion;
5797 FunctionTemplateDecl *ConvTemplate = dyn_cast<FunctionTemplateDecl>(D);
5798 if (ConvTemplate) {
5799 if (getLangOpts().CPlusPlus14)
5800 Conversion = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl());
5801 else
5802 continue; // C++11 does not consider conversion operator templates(?).
5803 } else
5804 Conversion = cast<CXXConversionDecl>(D);
5805
5806 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\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/Sema/SemaOverload.cpp"
, 5808, __PRETTY_FUNCTION__))
5807 "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\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/Sema/SemaOverload.cpp"
, 5808, __PRETTY_FUNCTION__))
5808 "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\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/Sema/SemaOverload.cpp"
, 5808, __PRETTY_FUNCTION__))
;
5809
5810 QualType CurToType = Conversion->getConversionType().getNonReferenceType();
5811 if (Converter.match(CurToType) || ConvTemplate) {
5812
5813 if (Conversion->isExplicit()) {
5814 // FIXME: For C++1y, do we need this restriction?
5815 // cf. diagnoseNoViableConversion()
5816 if (!ConvTemplate)
5817 ExplicitConversions.addDecl(I.getDecl(), I.getAccess());
5818 } else {
5819 if (!ConvTemplate && getLangOpts().CPlusPlus14) {
5820 if (ToType.isNull())
5821 ToType = CurToType.getUnqualifiedType();
5822 else if (HasUniqueTargetType &&
5823 (CurToType.getUnqualifiedType() != ToType))
5824 HasUniqueTargetType = false;
5825 }
5826 ViableConversions.addDecl(I.getDecl(), I.getAccess());
5827 }
5828 }
5829 }
5830
5831 if (getLangOpts().CPlusPlus14) {
5832 // C++1y [conv]p6:
5833 // ... An expression e of class type E appearing in such a context
5834 // is said to be contextually implicitly converted to a specified
5835 // type T and is well-formed if and only if e can be implicitly
5836 // converted to a type T that is determined as follows: E is searched
5837 // for conversion functions whose return type is cv T or reference to
5838 // cv T such that T is allowed by the context. There shall be
5839 // exactly one such T.
5840
5841 // If no unique T is found:
5842 if (ToType.isNull()) {
5843 if (diagnoseNoViableConversion(*this, Loc, From, Converter, T,
5844 HadMultipleCandidates,
5845 ExplicitConversions))
5846 return ExprError();
5847 return finishContextualImplicitConversion(*this, Loc, From, Converter);
5848 }
5849
5850 // If more than one unique Ts are found:
5851 if (!HasUniqueTargetType)
5852 return diagnoseAmbiguousConversion(*this, Loc, From, Converter, T,
5853 ViableConversions);
5854
5855 // If one unique T is found:
5856 // First, build a candidate set from the previously recorded
5857 // potentially viable conversions.
5858 OverloadCandidateSet CandidateSet(Loc, OverloadCandidateSet::CSK_Normal);
5859 collectViableConversionCandidates(*this, From, ToType, ViableConversions,
5860 CandidateSet);
5861
5862 // Then, perform overload resolution over the candidate set.
5863 OverloadCandidateSet::iterator Best;
5864 switch (CandidateSet.BestViableFunction(*this, Loc, Best)) {
5865 case OR_Success: {
5866 // Apply this conversion.
5867 DeclAccessPair Found =
5868 DeclAccessPair::make(Best->Function, Best->FoundDecl.getAccess());
5869 if (recordConversion(*this, Loc, From, Converter, T,
5870 HadMultipleCandidates, Found))
5871 return ExprError();
5872 break;
5873 }
5874 case OR_Ambiguous:
5875 return diagnoseAmbiguousConversion(*this, Loc, From, Converter, T,
5876 ViableConversions);
5877 case OR_No_Viable_Function:
5878 if (diagnoseNoViableConversion(*this, Loc, From, Converter, T,
5879 HadMultipleCandidates,
5880 ExplicitConversions))
5881 return ExprError();
5882 LLVM_FALLTHROUGH[[clang::fallthrough]];
5883 case OR_Deleted:
5884 // We'll complain below about a non-integral condition type.
5885 break;
5886 }
5887 } else {
5888 switch (ViableConversions.size()) {
5889 case 0: {
5890 if (diagnoseNoViableConversion(*this, Loc, From, Converter, T,
5891 HadMultipleCandidates,
5892 ExplicitConversions))
5893 return ExprError();
5894
5895 // We'll complain below about a non-integral condition type.
5896 break;
5897 }
5898 case 1: {
5899 // Apply this conversion.
5900 DeclAccessPair Found = ViableConversions[0];
5901 if (recordConversion(*this, Loc, From, Converter, T,
5902 HadMultipleCandidates, Found))
5903 return ExprError();
5904 break;
5905 }
5906 default:
5907 return diagnoseAmbiguousConversion(*this, Loc, From, Converter, T,
5908 ViableConversions);
5909 }
5910 }
5911
5912 return finishContextualImplicitConversion(*this, Loc, From, Converter);
5913}
5914
5915/// IsAcceptableNonMemberOperatorCandidate - Determine whether Fn is
5916/// an acceptable non-member overloaded operator for a call whose
5917/// arguments have types T1 (and, if non-empty, T2). This routine
5918/// implements the check in C++ [over.match.oper]p3b2 concerning
5919/// enumeration types.
5920static bool IsAcceptableNonMemberOperatorCandidate(ASTContext &Context,
5921 FunctionDecl *Fn,
5922 ArrayRef<Expr *> Args) {
5923 QualType T1 = Args[0]->getType();
5924 QualType T2 = Args.size() > 1 ? Args[1]->getType() : QualType();
5925
5926 if (T1->isDependentType() || (!T2.isNull() && T2->isDependentType()))
5927 return true;
5928
5929 if (T1->isRecordType() || (!T2.isNull() && T2->isRecordType()))
5930 return true;
5931
5932 const FunctionProtoType *Proto = Fn->getType()->getAs<FunctionProtoType>();
5933 if (Proto->getNumParams() < 1)
5934 return false;
5935
5936 if (T1->isEnumeralType()) {
5937 QualType ArgType = Proto->getParamType(0).getNonReferenceType();
5938 if (Context.hasSameUnqualifiedType(T1, ArgType))
5939 return true;
5940 }
5941
5942 if (Proto->getNumParams() < 2)
5943 return false;
5944
5945 if (!T2.isNull() && T2->isEnumeralType()) {
5946 QualType ArgType = Proto->getParamType(1).getNonReferenceType();
5947 if (Context.hasSameUnqualifiedType(T2, ArgType))
5948 return true;
5949 }
5950
5951 return false;
5952}
5953
5954/// AddOverloadCandidate - Adds the given function to the set of
5955/// candidate functions, using the given function call arguments. If
5956/// @p SuppressUserConversions, then don't allow user-defined
5957/// conversions via constructors or conversion operators.
5958///
5959/// \param PartialOverloading true if we are performing "partial" overloading
5960/// based on an incomplete set of function arguments. This feature is used by
5961/// code completion.
5962