Bug Summary

File:tools/clang/lib/Sema/SemaOverload.cpp
Warning:line 9872, column 50
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-9/lib/clang/9.0.0 -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-9~svn360825/build-llvm/tools/clang/lib/Sema -I /build/llvm-toolchain-snapshot-9~svn360825/tools/clang/lib/Sema -I /build/llvm-toolchain-snapshot-9~svn360825/tools/clang/include -I /build/llvm-toolchain-snapshot-9~svn360825/build-llvm/tools/clang/include -I /build/llvm-toolchain-snapshot-9~svn360825/build-llvm/include -I /build/llvm-toolchain-snapshot-9~svn360825/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/9.0.0/include/ -internal-isystem /usr/local/include -internal-isystem /usr/lib/llvm-9/lib/clang/9.0.0/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-9~svn360825/build-llvm/tools/clang/lib/Sema -fdebug-prefix-map=/build/llvm-toolchain-snapshot-9~svn360825=. -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-2019-05-16-032012-25149-1 -x c++ /build/llvm-toolchain-snapshot-9~svn360825/tools/clang/lib/Sema/SemaOverload.cpp -faddrsig
1//===--- SemaOverload.cpp - C++ Overloading -------------------------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// This file provides Sema routines for C++ overloading.
10//
11//===----------------------------------------------------------------------===//
12
13#include "clang/Sema/Overload.h"
14#include "clang/AST/ASTContext.h"
15#include "clang/AST/CXXInheritance.h"
16#include "clang/AST/DeclObjC.h"
17#include "clang/AST/Expr.h"
18#include "clang/AST/ExprCXX.h"
19#include "clang/AST/ExprObjC.h"
20#include "clang/AST/TypeOrdering.h"
21#include "clang/Basic/Diagnostic.h"
22#include "clang/Basic/DiagnosticOptions.h"
23#include "clang/Basic/PartialDiagnostic.h"
24#include "clang/Basic/TargetInfo.h"
25#include "clang/Sema/Initialization.h"
26#include "clang/Sema/Lookup.h"
27#include "clang/Sema/SemaInternal.h"
28#include "clang/Sema/Template.h"
29#include "clang/Sema/TemplateDeduction.h"
30#include "llvm/ADT/DenseSet.h"
31#include "llvm/ADT/Optional.h"
32#include "llvm/ADT/STLExtras.h"
33#include "llvm/ADT/SmallPtrSet.h"
34#include "llvm/ADT/SmallString.h"
35#include <algorithm>
36#include <cstdlib>
37
38using namespace clang;
39using namespace sema;
40
41static bool functionHasPassObjectSizeParams(const FunctionDecl *FD) {
42 return llvm::any_of(FD->parameters(), [](const ParmVarDecl *P) {
43 return P->hasAttr<PassObjectSizeAttr>();
44 });
45}
46
47/// A convenience routine for creating a decayed reference to a function.
48static ExprResult
49CreateFunctionRefExpr(Sema &S, FunctionDecl *Fn, NamedDecl *FoundDecl,
50 const Expr *Base, bool HadMultipleCandidates,
51 SourceLocation Loc = SourceLocation(),
52 const DeclarationNameLoc &LocInfo = DeclarationNameLoc()){
53 if (S.DiagnoseUseOfDecl(FoundDecl, Loc))
54 return ExprError();
55 // If FoundDecl is different from Fn (such as if one is a template
56 // and the other a specialization), make sure DiagnoseUseOfDecl is
57 // called on both.
58 // FIXME: This would be more comprehensively addressed by modifying
59 // DiagnoseUseOfDecl to accept both the FoundDecl and the decl
60 // being used.
61 if (FoundDecl != Fn && S.DiagnoseUseOfDecl(Fn, Loc))
62 return ExprError();
63 if (auto *FPT = Fn->getType()->getAs<FunctionProtoType>())
64 S.ResolveExceptionSpec(Loc, FPT);
65 DeclRefExpr *DRE = new (S.Context)
66 DeclRefExpr(S.Context, Fn, false, Fn->getType(), VK_LValue, Loc, LocInfo);
67 if (HadMultipleCandidates)
68 DRE->setHadMultipleCandidates(true);
69
70 S.MarkDeclRefReferenced(DRE, Base);
71 return S.ImpCastExprToType(DRE, S.Context.getPointerType(DRE->getType()),
72 CK_FunctionToPointerDecay);
73}
74
75static bool IsStandardConversion(Sema &S, Expr* From, QualType ToType,
76 bool InOverloadResolution,
77 StandardConversionSequence &SCS,
78 bool CStyle,
79 bool AllowObjCWritebackConversion);
80
81static bool IsTransparentUnionStandardConversion(Sema &S, Expr* From,
82 QualType &ToType,
83 bool InOverloadResolution,
84 StandardConversionSequence &SCS,
85 bool CStyle);
86static OverloadingResult
87IsUserDefinedConversion(Sema &S, Expr *From, QualType ToType,
88 UserDefinedConversionSequence& User,
89 OverloadCandidateSet& Conversions,
90 bool AllowExplicit,
91 bool AllowObjCConversionOnExplicit);
92
93
94static ImplicitConversionSequence::CompareKind
95CompareStandardConversionSequences(Sema &S, SourceLocation Loc,
96 const StandardConversionSequence& SCS1,
97 const StandardConversionSequence& SCS2);
98
99static ImplicitConversionSequence::CompareKind
100CompareQualificationConversions(Sema &S,
101 const StandardConversionSequence& SCS1,
102 const StandardConversionSequence& SCS2);
103
104static ImplicitConversionSequence::CompareKind
105CompareDerivedToBaseConversions(Sema &S, SourceLocation Loc,
106 const StandardConversionSequence& SCS1,
107 const StandardConversionSequence& SCS2);
108
109/// GetConversionRank - Retrieve the implicit conversion rank
110/// corresponding to the given implicit conversion kind.
111ImplicitConversionRank clang::GetConversionRank(ImplicitConversionKind Kind) {
112 static const ImplicitConversionRank
113 Rank[(int)ICK_Num_Conversion_Kinds] = {
114 ICR_Exact_Match,
115 ICR_Exact_Match,
116 ICR_Exact_Match,
117 ICR_Exact_Match,
118 ICR_Exact_Match,
119 ICR_Exact_Match,
120 ICR_Promotion,
121 ICR_Promotion,
122 ICR_Promotion,
123 ICR_Conversion,
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_OCL_Scalar_Widening,
134 ICR_Complex_Real_Conversion,
135 ICR_Conversion,
136 ICR_Conversion,
137 ICR_Writeback_Conversion,
138 ICR_Exact_Match, // NOTE(gbiv): This may not be completely right --
139 // it was omitted by the patch that added
140 // ICK_Zero_Event_Conversion
141 ICR_C_Conversion,
142 ICR_C_Conversion_Extension
143 };
144 return Rank[(int)Kind];
145}
146
147/// GetImplicitConversionName - Return the name of this kind of
148/// implicit conversion.
149static const char* GetImplicitConversionName(ImplicitConversionKind Kind) {
150 static const char* const Name[(int)ICK_Num_Conversion_Kinds] = {
151 "No conversion",
152 "Lvalue-to-rvalue",
153 "Array-to-pointer",
154 "Function-to-pointer",
155 "Function pointer conversion",
156 "Qualification",
157 "Integral promotion",
158 "Floating point promotion",
159 "Complex promotion",
160 "Integral conversion",
161 "Floating conversion",
162 "Complex conversion",
163 "Floating-integral conversion",
164 "Pointer conversion",
165 "Pointer-to-member conversion",
166 "Boolean conversion",
167 "Compatible-types conversion",
168 "Derived-to-base conversion",
169 "Vector conversion",
170 "Vector splat",
171 "Complex-real conversion",
172 "Block Pointer conversion",
173 "Transparent Union Conversion",
174 "Writeback conversion",
175 "OpenCL Zero Event Conversion",
176 "C specific type conversion",
177 "Incompatible pointer conversion"
178 };
179 return Name[Kind];
180}
181
182/// StandardConversionSequence - Set the standard conversion
183/// sequence to the identity conversion.
184void StandardConversionSequence::setAsIdentityConversion() {
185 First = ICK_Identity;
186 Second = ICK_Identity;
187 Third = ICK_Identity;
188 DeprecatedStringLiteralToCharPtr = false;
189 QualificationIncludesObjCLifetime = false;
190 ReferenceBinding = false;
191 DirectBinding = false;
192 IsLvalueReference = true;
193 BindsToFunctionLvalue = false;
194 BindsToRvalue = false;
195 BindsImplicitObjectArgumentWithoutRefQualifier = false;
196 ObjCLifetimeConversionBinding = false;
197 CopyConstructor = nullptr;
198}
199
200/// getRank - Retrieve the rank of this standard conversion sequence
201/// (C++ 13.3.3.1.1p3). The rank is the largest rank of each of the
202/// implicit conversions.
203ImplicitConversionRank StandardConversionSequence::getRank() const {
204 ImplicitConversionRank Rank = ICR_Exact_Match;
205 if (GetConversionRank(First) > Rank)
206 Rank = GetConversionRank(First);
207 if (GetConversionRank(Second) > Rank)
208 Rank = GetConversionRank(Second);
209 if (GetConversionRank(Third) > Rank)
210 Rank = GetConversionRank(Third);
211 return Rank;
212}
213
214/// isPointerConversionToBool - Determines whether this conversion is
215/// a conversion of a pointer or pointer-to-member to bool. This is
216/// used as part of the ranking of standard conversion sequences
217/// (C++ 13.3.3.2p4).
218bool StandardConversionSequence::isPointerConversionToBool() const {
219 // Note that FromType has not necessarily been transformed by the
220 // array-to-pointer or function-to-pointer implicit conversions, so
221 // check for their presence as well as checking whether FromType is
222 // a pointer.
223 if (getToType(1)->isBooleanType() &&
224 (getFromType()->isPointerType() ||
225 getFromType()->isMemberPointerType() ||
226 getFromType()->isObjCObjectPointerType() ||
227 getFromType()->isBlockPointerType() ||
228 getFromType()->isNullPtrType() ||
229 First == ICK_Array_To_Pointer || First == ICK_Function_To_Pointer))
230 return true;
231
232 return false;
233}
234
235/// isPointerConversionToVoidPointer - Determines whether this
236/// conversion is a conversion of a pointer to a void pointer. This is
237/// used as part of the ranking of standard conversion sequences (C++
238/// 13.3.3.2p4).
239bool
240StandardConversionSequence::
241isPointerConversionToVoidPointer(ASTContext& Context) const {
242 QualType FromType = getFromType();
243 QualType ToType = getToType(1);
244
245 // Note that FromType has not necessarily been transformed by the
246 // array-to-pointer implicit conversion, so check for its presence
247 // and redo the conversion to get a pointer.
248 if (First == ICK_Array_To_Pointer)
249 FromType = Context.getArrayDecayedType(FromType);
250
251 if (Second == ICK_Pointer_Conversion && FromType->isAnyPointerType())
252 if (const PointerType* ToPtrType = ToType->getAs<PointerType>())
253 return ToPtrType->getPointeeType()->isVoidType();
254
255 return false;
256}
257
258/// Skip any implicit casts which could be either part of a narrowing conversion
259/// or after one in an implicit conversion.
260static const Expr *IgnoreNarrowingConversion(const Expr *Converted) {
261 while (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(Converted)) {
262 switch (ICE->getCastKind()) {
263 case CK_NoOp:
264 case CK_IntegralCast:
265 case CK_IntegralToBoolean:
266 case CK_IntegralToFloating:
267 case CK_BooleanToSignedIntegral:
268 case CK_FloatingToIntegral:
269 case CK_FloatingToBoolean:
270 case CK_FloatingCast:
271 Converted = ICE->getSubExpr();
272 continue;
273
274 default:
275 return Converted;
276 }
277 }
278
279 return Converted;
280}
281
282/// Check if this standard conversion sequence represents a narrowing
283/// conversion, according to C++11 [dcl.init.list]p7.
284///
285/// \param Ctx The AST context.
286/// \param Converted The result of applying this standard conversion sequence.
287/// \param ConstantValue If this is an NK_Constant_Narrowing conversion, the
288/// value of the expression prior to the narrowing conversion.
289/// \param ConstantType If this is an NK_Constant_Narrowing conversion, the
290/// type of the expression prior to the narrowing conversion.
291/// \param IgnoreFloatToIntegralConversion If true type-narrowing conversions
292/// from floating point types to integral types should be ignored.
293NarrowingKind StandardConversionSequence::getNarrowingKind(
294 ASTContext &Ctx, const Expr *Converted, APValue &ConstantValue,
295 QualType &ConstantType, bool IgnoreFloatToIntegralConversion) const {
296 assert(Ctx.getLangOpts().CPlusPlus && "narrowing check outside C++")((Ctx.getLangOpts().CPlusPlus && "narrowing check outside C++"
) ? static_cast<void> (0) : __assert_fail ("Ctx.getLangOpts().CPlusPlus && \"narrowing check outside C++\""
, "/build/llvm-toolchain-snapshot-9~svn360825/tools/clang/lib/Sema/SemaOverload.cpp"
, 296, __PRETTY_FUNCTION__))
;
297
298 // C++11 [dcl.init.list]p7:
299 // A narrowing conversion is an implicit conversion ...
300 QualType FromType = getToType(0);
301 QualType ToType = getToType(1);
302
303 // A conversion to an enumeration type is narrowing if the conversion to
304 // the underlying type is narrowing. This only arises for expressions of
305 // the form 'Enum{init}'.
306 if (auto *ET = ToType->getAs<EnumType>())
307 ToType = ET->getDecl()->getIntegerType();
308
309 switch (Second) {
310 // 'bool' is an integral type; dispatch to the right place to handle it.
311 case ICK_Boolean_Conversion:
312 if (FromType->isRealFloatingType())
313 goto FloatingIntegralConversion;
314 if (FromType->isIntegralOrUnscopedEnumerationType())
315 goto IntegralConversion;
316 // Boolean conversions can be from pointers and pointers to members
317 // [conv.bool], and those aren't considered narrowing conversions.
318 return NK_Not_Narrowing;
319
320 // -- from a floating-point type to an integer type, or
321 //
322 // -- from an integer type or unscoped enumeration type to a floating-point
323 // type, except where the source is a constant expression and the actual
324 // value after conversion will fit into the target type and will produce
325 // the original value when converted back to the original type, or
326 case ICK_Floating_Integral:
327 FloatingIntegralConversion:
328 if (FromType->isRealFloatingType() && ToType->isIntegralType(Ctx)) {
329 return NK_Type_Narrowing;
330 } else if (FromType->isIntegralOrUnscopedEnumerationType() &&
331 ToType->isRealFloatingType()) {
332 if (IgnoreFloatToIntegralConversion)
333 return NK_Not_Narrowing;
334 llvm::APSInt IntConstantValue;
335 const Expr *Initializer = IgnoreNarrowingConversion(Converted);
336 assert(Initializer && "Unknown conversion expression")((Initializer && "Unknown conversion expression") ? static_cast
<void> (0) : __assert_fail ("Initializer && \"Unknown conversion expression\""
, "/build/llvm-toolchain-snapshot-9~svn360825/tools/clang/lib/Sema/SemaOverload.cpp"
, 336, __PRETTY_FUNCTION__))
;
337
338 // If it's value-dependent, we can't tell whether it's narrowing.
339 if (Initializer->isValueDependent())
340 return NK_Dependent_Narrowing;
341
342 if (Initializer->isIntegerConstantExpr(IntConstantValue, Ctx)) {
343 // Convert the integer to the floating type.
344 llvm::APFloat Result(Ctx.getFloatTypeSemantics(ToType));
345 Result.convertFromAPInt(IntConstantValue, IntConstantValue.isSigned(),
346 llvm::APFloat::rmNearestTiesToEven);
347 // And back.
348 llvm::APSInt ConvertedValue = IntConstantValue;
349 bool ignored;
350 Result.convertToInteger(ConvertedValue,
351 llvm::APFloat::rmTowardZero, &ignored);
352 // If the resulting value is different, this was a narrowing conversion.
353 if (IntConstantValue != ConvertedValue) {
354 ConstantValue = APValue(IntConstantValue);
355 ConstantType = Initializer->getType();
356 return NK_Constant_Narrowing;
357 }
358 } else {
359 // Variables are always narrowings.
360 return NK_Variable_Narrowing;
361 }
362 }
363 return NK_Not_Narrowing;
364
365 // -- from long double to double or float, or from double to float, except
366 // where the source is a constant expression and the actual value after
367 // conversion is within the range of values that can be represented (even
368 // if it cannot be represented exactly), or
369 case ICK_Floating_Conversion:
370 if (FromType->isRealFloatingType() && ToType->isRealFloatingType() &&
371 Ctx.getFloatingTypeOrder(FromType, ToType) == 1) {
372 // FromType is larger than ToType.
373 const Expr *Initializer = IgnoreNarrowingConversion(Converted);
374
375 // If it's value-dependent, we can't tell whether it's narrowing.
376 if (Initializer->isValueDependent())
377 return NK_Dependent_Narrowing;
378
379 if (Initializer->isCXX11ConstantExpr(Ctx, &ConstantValue)) {
380 // Constant!
381 assert(ConstantValue.isFloat())((ConstantValue.isFloat()) ? static_cast<void> (0) : __assert_fail
("ConstantValue.isFloat()", "/build/llvm-toolchain-snapshot-9~svn360825/tools/clang/lib/Sema/SemaOverload.cpp"
, 381, __PRETTY_FUNCTION__))
;
382 llvm::APFloat FloatVal = ConstantValue.getFloat();
383 // Convert the source value into the target type.
384 bool ignored;
385 llvm::APFloat::opStatus ConvertStatus = FloatVal.convert(
386 Ctx.getFloatTypeSemantics(ToType),
387 llvm::APFloat::rmNearestTiesToEven, &ignored);
388 // If there was no overflow, the source value is within the range of
389 // values that can be represented.
390 if (ConvertStatus & llvm::APFloat::opOverflow) {
391 ConstantType = Initializer->getType();
392 return NK_Constant_Narrowing;
393 }
394 } else {
395 return NK_Variable_Narrowing;
396 }
397 }
398 return NK_Not_Narrowing;
399
400 // -- from an integer type or unscoped enumeration type to an integer type
401 // that cannot represent all the values of the original type, except where
402 // the source is a constant expression and the actual value after
403 // conversion will fit into the target type and will produce the original
404 // value when converted back to the original type.
405 case ICK_Integral_Conversion:
406 IntegralConversion: {
407 assert(FromType->isIntegralOrUnscopedEnumerationType())((FromType->isIntegralOrUnscopedEnumerationType()) ? static_cast
<void> (0) : __assert_fail ("FromType->isIntegralOrUnscopedEnumerationType()"
, "/build/llvm-toolchain-snapshot-9~svn360825/tools/clang/lib/Sema/SemaOverload.cpp"
, 407, __PRETTY_FUNCTION__))
;
408 assert(ToType->isIntegralOrUnscopedEnumerationType())((ToType->isIntegralOrUnscopedEnumerationType()) ? static_cast
<void> (0) : __assert_fail ("ToType->isIntegralOrUnscopedEnumerationType()"
, "/build/llvm-toolchain-snapshot-9~svn360825/tools/clang/lib/Sema/SemaOverload.cpp"
, 408, __PRETTY_FUNCTION__))
;
409 const bool FromSigned = FromType->isSignedIntegerOrEnumerationType();
410 const unsigned FromWidth = Ctx.getIntWidth(FromType);
411 const bool ToSigned = ToType->isSignedIntegerOrEnumerationType();
412 const unsigned ToWidth = Ctx.getIntWidth(ToType);
413
414 if (FromWidth > ToWidth ||
415 (FromWidth == ToWidth && FromSigned != ToSigned) ||
416 (FromSigned && !ToSigned)) {
417 // Not all values of FromType can be represented in ToType.
418 llvm::APSInt InitializerValue;
419 const Expr *Initializer = IgnoreNarrowingConversion(Converted);
420
421 // If it's value-dependent, we can't tell whether it's narrowing.
422 if (Initializer->isValueDependent())
423 return NK_Dependent_Narrowing;
424
425 if (!Initializer->isIntegerConstantExpr(InitializerValue, Ctx)) {
426 // Such conversions on variables are always narrowing.
427 return NK_Variable_Narrowing;
428 }
429 bool Narrowing = false;
430 if (FromWidth < ToWidth) {
431 // Negative -> unsigned is narrowing. Otherwise, more bits is never
432 // narrowing.
433 if (InitializerValue.isSigned() && InitializerValue.isNegative())
434 Narrowing = true;
435 } else {
436 // Add a bit to the InitializerValue so we don't have to worry about
437 // signed vs. unsigned comparisons.
438 InitializerValue = InitializerValue.extend(
439 InitializerValue.getBitWidth() + 1);
440 // Convert the initializer to and from the target width and signed-ness.
441 llvm::APSInt ConvertedValue = InitializerValue;
442 ConvertedValue = ConvertedValue.trunc(ToWidth);
443 ConvertedValue.setIsSigned(ToSigned);
444 ConvertedValue = ConvertedValue.extend(InitializerValue.getBitWidth());
445 ConvertedValue.setIsSigned(InitializerValue.isSigned());
446 // If the result is different, this was a narrowing conversion.
447 if (ConvertedValue != InitializerValue)
448 Narrowing = true;
449 }
450 if (Narrowing) {
451 ConstantType = Initializer->getType();
452 ConstantValue = APValue(InitializerValue);
453 return NK_Constant_Narrowing;
454 }
455 }
456 return NK_Not_Narrowing;
457 }
458
459 default:
460 // Other kinds of conversions are not narrowings.
461 return NK_Not_Narrowing;
462 }
463}
464
465/// dump - Print this standard conversion sequence to standard
466/// error. Useful for debugging overloading issues.
467LLVM_DUMP_METHOD__attribute__((noinline)) __attribute__((__used__)) void StandardConversionSequence::dump() const {
468 raw_ostream &OS = llvm::errs();
469 bool PrintedSomething = false;
470 if (First != ICK_Identity) {
471 OS << GetImplicitConversionName(First);
472 PrintedSomething = true;
473 }
474
475 if (Second != ICK_Identity) {
476 if (PrintedSomething) {
477 OS << " -> ";
478 }
479 OS << GetImplicitConversionName(Second);
480
481 if (CopyConstructor) {
482 OS << " (by copy constructor)";
483 } else if (DirectBinding) {
484 OS << " (direct reference binding)";
485 } else if (ReferenceBinding) {
486 OS << " (reference binding)";
487 }
488 PrintedSomething = true;
489 }
490
491 if (Third != ICK_Identity) {
492 if (PrintedSomething) {
493 OS << " -> ";
494 }
495 OS << GetImplicitConversionName(Third);
496 PrintedSomething = true;
497 }
498
499 if (!PrintedSomething) {
500 OS << "No conversions required";
501 }
502}
503
504/// dump - Print this user-defined conversion sequence to standard
505/// error. Useful for debugging overloading issues.
506void UserDefinedConversionSequence::dump() const {
507 raw_ostream &OS = llvm::errs();
508 if (Before.First || Before.Second || Before.Third) {
509 Before.dump();
510 OS << " -> ";
511 }
512 if (ConversionFunction)
513 OS << '\'' << *ConversionFunction << '\'';
514 else
515 OS << "aggregate initialization";
516 if (After.First || After.Second || After.Third) {
517 OS << " -> ";
518 After.dump();
519 }
520}
521
522/// dump - Print this implicit conversion sequence to standard
523/// error. Useful for debugging overloading issues.
524void ImplicitConversionSequence::dump() const {
525 raw_ostream &OS = llvm::errs();
526 if (isStdInitializerListElement())
527 OS << "Worst std::initializer_list element conversion: ";
528 switch (ConversionKind) {
529 case StandardConversion:
530 OS << "Standard conversion: ";
531 Standard.dump();
532 break;
533 case UserDefinedConversion:
534 OS << "User-defined conversion: ";
535 UserDefined.dump();
536 break;
537 case EllipsisConversion:
538 OS << "Ellipsis conversion";
539 break;
540 case AmbiguousConversion:
541 OS << "Ambiguous conversion";
542 break;
543 case BadConversion:
544 OS << "Bad conversion";
545 break;
546 }
547
548 OS << "\n";
549}
550
551void AmbiguousConversionSequence::construct() {
552 new (&conversions()) ConversionSet();
553}
554
555void AmbiguousConversionSequence::destruct() {
556 conversions().~ConversionSet();
557}
558
559void
560AmbiguousConversionSequence::copyFrom(const AmbiguousConversionSequence &O) {
561 FromTypePtr = O.FromTypePtr;
562 ToTypePtr = O.ToTypePtr;
563 new (&conversions()) ConversionSet(O.conversions());
564}
565
566namespace {
567 // Structure used by DeductionFailureInfo to store
568 // template argument information.
569 struct DFIArguments {
570 TemplateArgument FirstArg;
571 TemplateArgument SecondArg;
572 };
573 // Structure used by DeductionFailureInfo to store
574 // template parameter and template argument information.
575 struct DFIParamWithArguments : DFIArguments {
576 TemplateParameter Param;
577 };
578 // Structure used by DeductionFailureInfo to store template argument
579 // information and the index of the problematic call argument.
580 struct DFIDeducedMismatchArgs : DFIArguments {
581 TemplateArgumentList *TemplateArgs;
582 unsigned CallArgIndex;
583 };
584}
585
586/// Convert from Sema's representation of template deduction information
587/// to the form used in overload-candidate information.
588DeductionFailureInfo
589clang::MakeDeductionFailureInfo(ASTContext &Context,
590 Sema::TemplateDeductionResult TDK,
591 TemplateDeductionInfo &Info) {
592 DeductionFailureInfo Result;
593 Result.Result = static_cast<unsigned>(TDK);
594 Result.HasDiagnostic = false;
595 switch (TDK) {
596 case Sema::TDK_Invalid:
597 case Sema::TDK_InstantiationDepth:
598 case Sema::TDK_TooManyArguments:
599 case Sema::TDK_TooFewArguments:
600 case Sema::TDK_MiscellaneousDeductionFailure:
601 case Sema::TDK_CUDATargetMismatch:
602 Result.Data = nullptr;
603 break;
604
605 case Sema::TDK_Incomplete:
606 case Sema::TDK_InvalidExplicitArguments:
607 Result.Data = Info.Param.getOpaqueValue();
608 break;
609
610 case Sema::TDK_DeducedMismatch:
611 case Sema::TDK_DeducedMismatchNested: {
612 // FIXME: Should allocate from normal heap so that we can free this later.
613 auto *Saved = new (Context) DFIDeducedMismatchArgs;
614 Saved->FirstArg = Info.FirstArg;
615 Saved->SecondArg = Info.SecondArg;
616 Saved->TemplateArgs = Info.take();
617 Saved->CallArgIndex = Info.CallArgIndex;
618 Result.Data = Saved;
619 break;
620 }
621
622 case Sema::TDK_NonDeducedMismatch: {
623 // FIXME: Should allocate from normal heap so that we can free this later.
624 DFIArguments *Saved = new (Context) DFIArguments;
625 Saved->FirstArg = Info.FirstArg;
626 Saved->SecondArg = Info.SecondArg;
627 Result.Data = Saved;
628 break;
629 }
630
631 case Sema::TDK_IncompletePack:
632 // FIXME: It's slightly wasteful to allocate two TemplateArguments for this.
633 case Sema::TDK_Inconsistent:
634 case Sema::TDK_Underqualified: {
635 // FIXME: Should allocate from normal heap so that we can free this later.
636 DFIParamWithArguments *Saved = new (Context) DFIParamWithArguments;
637 Saved->Param = Info.Param;
638 Saved->FirstArg = Info.FirstArg;
639 Saved->SecondArg = Info.SecondArg;
640 Result.Data = Saved;
641 break;
642 }
643
644 case Sema::TDK_SubstitutionFailure:
645 Result.Data = Info.take();
646 if (Info.hasSFINAEDiagnostic()) {
647 PartialDiagnosticAt *Diag = new (Result.Diagnostic) PartialDiagnosticAt(
648 SourceLocation(), PartialDiagnostic::NullDiagnostic());
649 Info.takeSFINAEDiagnostic(*Diag);
650 Result.HasDiagnostic = true;
651 }
652 break;
653
654 case Sema::TDK_Success:
655 case Sema::TDK_NonDependentConversionFailure:
656 llvm_unreachable("not a deduction failure")::llvm::llvm_unreachable_internal("not a deduction failure", "/build/llvm-toolchain-snapshot-9~svn360825/tools/clang/lib/Sema/SemaOverload.cpp"
, 656)
;
657 }
658
659 return Result;
660}
661
662void DeductionFailureInfo::Destroy() {
663 switch (static_cast<Sema::TemplateDeductionResult>(Result)) {
664 case Sema::TDK_Success:
665 case Sema::TDK_Invalid:
666 case Sema::TDK_InstantiationDepth:
667 case Sema::TDK_Incomplete:
668 case Sema::TDK_TooManyArguments:
669 case Sema::TDK_TooFewArguments:
670 case Sema::TDK_InvalidExplicitArguments:
671 case Sema::TDK_CUDATargetMismatch:
672 case Sema::TDK_NonDependentConversionFailure:
673 break;
674
675 case Sema::TDK_IncompletePack:
676 case Sema::TDK_Inconsistent:
677 case Sema::TDK_Underqualified:
678 case Sema::TDK_DeducedMismatch:
679 case Sema::TDK_DeducedMismatchNested:
680 case Sema::TDK_NonDeducedMismatch:
681 // FIXME: Destroy the data?
682 Data = nullptr;
683 break;
684
685 case Sema::TDK_SubstitutionFailure:
686 // FIXME: Destroy the template argument list?
687 Data = nullptr;
688 if (PartialDiagnosticAt *Diag = getSFINAEDiagnostic()) {
689 Diag->~PartialDiagnosticAt();
690 HasDiagnostic = false;
691 }
692 break;
693
694 // Unhandled
695 case Sema::TDK_MiscellaneousDeductionFailure:
696 break;
697 }
698}
699
700PartialDiagnosticAt *DeductionFailureInfo::getSFINAEDiagnostic() {
701 if (HasDiagnostic)
702 return static_cast<PartialDiagnosticAt*>(static_cast<void*>(Diagnostic));
703 return nullptr;
704}
705
706TemplateParameter DeductionFailureInfo::getTemplateParameter() {
707 switch (static_cast<Sema::TemplateDeductionResult>(Result)) {
708 case Sema::TDK_Success:
709 case Sema::TDK_Invalid:
710 case Sema::TDK_InstantiationDepth:
711 case Sema::TDK_TooManyArguments:
712 case Sema::TDK_TooFewArguments:
713 case Sema::TDK_SubstitutionFailure:
714 case Sema::TDK_DeducedMismatch:
715 case Sema::TDK_DeducedMismatchNested:
716 case Sema::TDK_NonDeducedMismatch:
717 case Sema::TDK_CUDATargetMismatch:
718 case Sema::TDK_NonDependentConversionFailure:
719 return TemplateParameter();
720
721 case Sema::TDK_Incomplete:
722 case Sema::TDK_InvalidExplicitArguments:
723 return TemplateParameter::getFromOpaqueValue(Data);
724
725 case Sema::TDK_IncompletePack:
726 case Sema::TDK_Inconsistent:
727 case Sema::TDK_Underqualified:
728 return static_cast<DFIParamWithArguments*>(Data)->Param;
729
730 // Unhandled
731 case Sema::TDK_MiscellaneousDeductionFailure:
732 break;
733 }
734
735 return TemplateParameter();
736}
737
738TemplateArgumentList *DeductionFailureInfo::getTemplateArgumentList() {
739 switch (static_cast<Sema::TemplateDeductionResult>(Result)) {
740 case Sema::TDK_Success:
741 case Sema::TDK_Invalid:
742 case Sema::TDK_InstantiationDepth:
743 case Sema::TDK_TooManyArguments:
744 case Sema::TDK_TooFewArguments:
745 case Sema::TDK_Incomplete:
746 case Sema::TDK_IncompletePack:
747 case Sema::TDK_InvalidExplicitArguments:
748 case Sema::TDK_Inconsistent:
749 case Sema::TDK_Underqualified:
750 case Sema::TDK_NonDeducedMismatch:
751 case Sema::TDK_CUDATargetMismatch:
752 case Sema::TDK_NonDependentConversionFailure:
753 return nullptr;
754
755 case Sema::TDK_DeducedMismatch:
756 case Sema::TDK_DeducedMismatchNested:
757 return static_cast<DFIDeducedMismatchArgs*>(Data)->TemplateArgs;
758
759 case Sema::TDK_SubstitutionFailure:
760 return static_cast<TemplateArgumentList*>(Data);
761
762 // Unhandled
763 case Sema::TDK_MiscellaneousDeductionFailure:
764 break;
765 }
766
767 return nullptr;
768}
769
770const TemplateArgument *DeductionFailureInfo::getFirstArg() {
771 switch (static_cast<Sema::TemplateDeductionResult>(Result)) {
772 case Sema::TDK_Success:
773 case Sema::TDK_Invalid:
774 case Sema::TDK_InstantiationDepth:
775 case Sema::TDK_Incomplete:
776 case Sema::TDK_TooManyArguments:
777 case Sema::TDK_TooFewArguments:
778 case Sema::TDK_InvalidExplicitArguments:
779 case Sema::TDK_SubstitutionFailure:
780 case Sema::TDK_CUDATargetMismatch:
781 case Sema::TDK_NonDependentConversionFailure:
782 return nullptr;
783
784 case Sema::TDK_IncompletePack:
785 case Sema::TDK_Inconsistent:
786 case Sema::TDK_Underqualified:
787 case Sema::TDK_DeducedMismatch:
788 case Sema::TDK_DeducedMismatchNested:
789 case Sema::TDK_NonDeducedMismatch:
790 return &static_cast<DFIArguments*>(Data)->FirstArg;
791
792 // Unhandled
793 case Sema::TDK_MiscellaneousDeductionFailure:
794 break;
795 }
796
797 return nullptr;
798}
799
800const TemplateArgument *DeductionFailureInfo::getSecondArg() {
801 switch (static_cast<Sema::TemplateDeductionResult>(Result)) {
802 case Sema::TDK_Success:
803 case Sema::TDK_Invalid:
804 case Sema::TDK_InstantiationDepth:
805 case Sema::TDK_Incomplete:
806 case Sema::TDK_IncompletePack:
807 case Sema::TDK_TooManyArguments:
808 case Sema::TDK_TooFewArguments:
809 case Sema::TDK_InvalidExplicitArguments:
810 case Sema::TDK_SubstitutionFailure:
811 case Sema::TDK_CUDATargetMismatch:
812 case Sema::TDK_NonDependentConversionFailure:
813 return nullptr;
814
815 case Sema::TDK_Inconsistent:
816 case Sema::TDK_Underqualified:
817 case Sema::TDK_DeducedMismatch:
818 case Sema::TDK_DeducedMismatchNested:
819 case Sema::TDK_NonDeducedMismatch:
820 return &static_cast<DFIArguments*>(Data)->SecondArg;
821
822 // Unhandled
823 case Sema::TDK_MiscellaneousDeductionFailure:
824 break;
825 }
826
827 return nullptr;
828}
829
830llvm::Optional<unsigned> DeductionFailureInfo::getCallArgIndex() {
831 switch (static_cast<Sema::TemplateDeductionResult>(Result)) {
832 case Sema::TDK_DeducedMismatch:
833 case Sema::TDK_DeducedMismatchNested:
834 return static_cast<DFIDeducedMismatchArgs*>(Data)->CallArgIndex;
835
836 default:
837 return llvm::None;
838 }
839}
840
841void OverloadCandidateSet::destroyCandidates() {
842 for (iterator i = begin(), e = end(); i != e; ++i) {
843 for (auto &C : i->Conversions)
844 C.~ImplicitConversionSequence();
845 if (!i->Viable && i->FailureKind == ovl_fail_bad_deduction)
846 i->DeductionFailure.Destroy();
847 }
848}
849
850void OverloadCandidateSet::clear(CandidateSetKind CSK) {
851 destroyCandidates();
852 SlabAllocator.Reset();
853 NumInlineBytesUsed = 0;
854 Candidates.clear();
855 Functions.clear();
856 Kind = CSK;
857}
858
859namespace {
860 class UnbridgedCastsSet {
861 struct Entry {
862 Expr **Addr;
863 Expr *Saved;
864 };
865 SmallVector<Entry, 2> Entries;
866
867 public:
868 void save(Sema &S, Expr *&E) {
869 assert(E->hasPlaceholderType(BuiltinType::ARCUnbridgedCast))((E->hasPlaceholderType(BuiltinType::ARCUnbridgedCast)) ? static_cast
<void> (0) : __assert_fail ("E->hasPlaceholderType(BuiltinType::ARCUnbridgedCast)"
, "/build/llvm-toolchain-snapshot-9~svn360825/tools/clang/lib/Sema/SemaOverload.cpp"
, 869, __PRETTY_FUNCTION__))
;
870 Entry entry = { &E, E };
871 Entries.push_back(entry);
872 E = S.stripARCUnbridgedCast(E);
873 }
874
875 void restore() {
876 for (SmallVectorImpl<Entry>::iterator
877 i = Entries.begin(), e = Entries.end(); i != e; ++i)
878 *i->Addr = i->Saved;
879 }
880 };
881}
882
883/// checkPlaceholderForOverload - Do any interesting placeholder-like
884/// preprocessing on the given expression.
885///
886/// \param unbridgedCasts a collection to which to add unbridged casts;
887/// without this, they will be immediately diagnosed as errors
888///
889/// Return true on unrecoverable error.
890static bool
891checkPlaceholderForOverload(Sema &S, Expr *&E,
892 UnbridgedCastsSet *unbridgedCasts = nullptr) {
893 if (const BuiltinType *placeholder = E->getType()->getAsPlaceholderType()) {
894 // We can't handle overloaded expressions here because overload
895 // resolution might reasonably tweak them.
896 if (placeholder->getKind() == BuiltinType::Overload) return false;
897
898 // If the context potentially accepts unbridged ARC casts, strip
899 // the unbridged cast and add it to the collection for later restoration.
900 if (placeholder->getKind() == BuiltinType::ARCUnbridgedCast &&
901 unbridgedCasts) {
902 unbridgedCasts->save(S, E);
903 return false;
904 }
905
906 // Go ahead and check everything else.
907 ExprResult result = S.CheckPlaceholderExpr(E);
908 if (result.isInvalid())
909 return true;
910
911 E = result.get();
912 return false;
913 }
914
915 // Nothing to do.
916 return false;
917}
918
919/// checkArgPlaceholdersForOverload - Check a set of call operands for
920/// placeholders.
921static bool checkArgPlaceholdersForOverload(Sema &S,
922 MultiExprArg Args,
923 UnbridgedCastsSet &unbridged) {
924 for (unsigned i = 0, e = Args.size(); i != e; ++i)
925 if (checkPlaceholderForOverload(S, Args[i], &unbridged))
926 return true;
927
928 return false;
929}
930
931/// Determine whether the given New declaration is an overload of the
932/// declarations in Old. This routine returns Ovl_Match or Ovl_NonFunction if
933/// New and Old cannot be overloaded, e.g., if New has the same signature as
934/// some function in Old (C++ 1.3.10) or if the Old declarations aren't
935/// functions (or function templates) at all. When it does return Ovl_Match or
936/// Ovl_NonFunction, MatchedDecl will point to the decl that New cannot be
937/// overloaded with. This decl may be a UsingShadowDecl on top of the underlying
938/// declaration.
939///
940/// Example: Given the following input:
941///
942/// void f(int, float); // #1
943/// void f(int, int); // #2
944/// int f(int, int); // #3
945///
946/// When we process #1, there is no previous declaration of "f", so IsOverload
947/// will not be used.
948///
949/// When we process #2, Old contains only the FunctionDecl for #1. By comparing
950/// the parameter types, we see that #1 and #2 are overloaded (since they have
951/// different signatures), so this routine returns Ovl_Overload; MatchedDecl is
952/// unchanged.
953///
954/// When we process #3, Old is an overload set containing #1 and #2. We compare
955/// the signatures of #3 to #1 (they're overloaded, so we do nothing) and then
956/// #3 to #2. Since the signatures of #3 and #2 are identical (return types of
957/// functions are not part of the signature), IsOverload returns Ovl_Match and
958/// MatchedDecl will be set to point to the FunctionDecl for #2.
959///
960/// 'NewIsUsingShadowDecl' indicates that 'New' is being introduced into a class
961/// by a using declaration. The rules for whether to hide shadow declarations
962/// ignore some properties which otherwise figure into a function template's
963/// signature.
964Sema::OverloadKind
965Sema::CheckOverload(Scope *S, FunctionDecl *New, const LookupResult &Old,
966 NamedDecl *&Match, bool NewIsUsingDecl) {
967 for (LookupResult::iterator I = Old.begin(), E = Old.end();
968 I != E; ++I) {
969 NamedDecl *OldD = *I;
970
971 bool OldIsUsingDecl = false;
972 if (isa<UsingShadowDecl>(OldD)) {
973 OldIsUsingDecl = true;
974
975 // We can always introduce two using declarations into the same
976 // context, even if they have identical signatures.
977 if (NewIsUsingDecl) continue;
978
979 OldD = cast<UsingShadowDecl>(OldD)->getTargetDecl();
980 }
981
982 // A using-declaration does not conflict with another declaration
983 // if one of them is hidden.
984 if ((OldIsUsingDecl || NewIsUsingDecl) && !isVisible(*I))
985 continue;
986
987 // If either declaration was introduced by a using declaration,
988 // we'll need to use slightly different rules for matching.
989 // Essentially, these rules are the normal rules, except that
990 // function templates hide function templates with different
991 // return types or template parameter lists.
992 bool UseMemberUsingDeclRules =
993 (OldIsUsingDecl || NewIsUsingDecl) && CurContext->isRecord() &&
994 !New->getFriendObjectKind();
995
996 if (FunctionDecl *OldF = OldD->getAsFunction()) {
997 if (!IsOverload(New, OldF, UseMemberUsingDeclRules)) {
998 if (UseMemberUsingDeclRules && OldIsUsingDecl) {
999 HideUsingShadowDecl(S, cast<UsingShadowDecl>(*I));
1000 continue;
1001 }
1002
1003 if (!isa<FunctionTemplateDecl>(OldD) &&
1004 !shouldLinkPossiblyHiddenDecl(*I, New))
1005 continue;
1006
1007 Match = *I;
1008 return Ovl_Match;
1009 }
1010
1011 // Builtins that have custom typechecking or have a reference should
1012 // not be overloadable or redeclarable.
1013 if (!getASTContext().canBuiltinBeRedeclared(OldF)) {
1014 Match = *I;
1015 return Ovl_NonFunction;
1016 }
1017 } else if (isa<UsingDecl>(OldD) || isa<UsingPackDecl>(OldD)) {
1018 // We can overload with these, which can show up when doing
1019 // redeclaration checks for UsingDecls.
1020 assert(Old.getLookupKind() == LookupUsingDeclName)((Old.getLookupKind() == LookupUsingDeclName) ? static_cast<
void> (0) : __assert_fail ("Old.getLookupKind() == LookupUsingDeclName"
, "/build/llvm-toolchain-snapshot-9~svn360825/tools/clang/lib/Sema/SemaOverload.cpp"
, 1020, __PRETTY_FUNCTION__))
;
1021 } else if (isa<TagDecl>(OldD)) {
1022 // We can always overload with tags by hiding them.
1023 } else if (auto *UUD = dyn_cast<UnresolvedUsingValueDecl>(OldD)) {
1024 // Optimistically assume that an unresolved using decl will
1025 // overload; if it doesn't, we'll have to diagnose during
1026 // template instantiation.
1027 //
1028 // Exception: if the scope is dependent and this is not a class
1029 // member, the using declaration can only introduce an enumerator.
1030 if (UUD->getQualifier()->isDependent() && !UUD->isCXXClassMember()) {
1031 Match = *I;
1032 return Ovl_NonFunction;
1033 }
1034 } else {
1035 // (C++ 13p1):
1036 // Only function declarations can be overloaded; object and type
1037 // declarations cannot be overloaded.
1038 Match = *I;
1039 return Ovl_NonFunction;
1040 }
1041 }
1042
1043 // C++ [temp.friend]p1:
1044 // For a friend function declaration that is not a template declaration:
1045 // -- if the name of the friend is a qualified or unqualified template-id,
1046 // [...], otherwise
1047 // -- if the name of the friend is a qualified-id and a matching
1048 // non-template function is found in the specified class or namespace,
1049 // the friend declaration refers to that function, otherwise,
1050 // -- if the name of the friend is a qualified-id and a matching function
1051 // template is found in the specified class or namespace, the friend
1052 // declaration refers to the deduced specialization of that function
1053 // template, otherwise
1054 // -- the name shall be an unqualified-id [...]
1055 // If we get here for a qualified friend declaration, we've just reached the
1056 // third bullet. If the type of the friend is dependent, skip this lookup
1057 // until instantiation.
1058 if (New->getFriendObjectKind() && New->getQualifier() &&
1059 !New->getDescribedFunctionTemplate() &&
1060 !New->getDependentSpecializationInfo() &&
1061 !New->getType()->isDependentType()) {
1062 LookupResult TemplateSpecResult(LookupResult::Temporary, Old);
1063 TemplateSpecResult.addAllDecls(Old);
1064 if (CheckFunctionTemplateSpecialization(New, nullptr, TemplateSpecResult,
1065 /*QualifiedFriend*/true)) {
1066 New->setInvalidDecl();
1067 return Ovl_Overload;
1068 }
1069
1070 Match = TemplateSpecResult.getAsSingle<FunctionDecl>();
1071 return Ovl_Match;
1072 }
1073
1074 return Ovl_Overload;
1075}
1076
1077bool Sema::IsOverload(FunctionDecl *New, FunctionDecl *Old,
1078 bool UseMemberUsingDeclRules, bool ConsiderCudaAttrs) {
1079 // C++ [basic.start.main]p2: This function shall not be overloaded.
1080 if (New->isMain())
1081 return false;
1082
1083 // MSVCRT user defined entry points cannot be overloaded.
1084 if (New->isMSVCRTEntryPoint())
1085 return false;
1086
1087 FunctionTemplateDecl *OldTemplate = Old->getDescribedFunctionTemplate();
1088 FunctionTemplateDecl *NewTemplate = New->getDescribedFunctionTemplate();
1089
1090 // C++ [temp.fct]p2:
1091 // A function template can be overloaded with other function templates
1092 // and with normal (non-template) functions.
1093 if ((OldTemplate == nullptr) != (NewTemplate == nullptr))
1094 return true;
1095
1096 // Is the function New an overload of the function Old?
1097 QualType OldQType = Context.getCanonicalType(Old->getType());
1098 QualType NewQType = Context.getCanonicalType(New->getType());
1099
1100 // Compare the signatures (C++ 1.3.10) of the two functions to
1101 // determine whether they are overloads. If we find any mismatch
1102 // in the signature, they are overloads.
1103
1104 // If either of these functions is a K&R-style function (no
1105 // prototype), then we consider them to have matching signatures.
1106 if (isa<FunctionNoProtoType>(OldQType.getTypePtr()) ||
1107 isa<FunctionNoProtoType>(NewQType.getTypePtr()))
1108 return false;
1109
1110 const FunctionProtoType *OldType = cast<FunctionProtoType>(OldQType);
1111 const FunctionProtoType *NewType = cast<FunctionProtoType>(NewQType);
1112
1113 // The signature of a function includes the types of its
1114 // parameters (C++ 1.3.10), which includes the presence or absence
1115 // of the ellipsis; see C++ DR 357).
1116 if (OldQType != NewQType &&
1117 (OldType->getNumParams() != NewType->getNumParams() ||
1118 OldType->isVariadic() != NewType->isVariadic() ||
1119 !FunctionParamTypesAreEqual(OldType, NewType)))
1120 return true;
1121
1122 // C++ [temp.over.link]p4:
1123 // The signature of a function template consists of its function
1124 // signature, its return type and its template parameter list. The names
1125 // of the template parameters are significant only for establishing the
1126 // relationship between the template parameters and the rest of the
1127 // signature.
1128 //
1129 // We check the return type and template parameter lists for function
1130 // templates first; the remaining checks follow.
1131 //
1132 // However, we don't consider either of these when deciding whether
1133 // a member introduced by a shadow declaration is hidden.
1134 if (!UseMemberUsingDeclRules && NewTemplate &&
1135 (!TemplateParameterListsAreEqual(NewTemplate->getTemplateParameters(),
1136 OldTemplate->getTemplateParameters(),
1137 false, TPL_TemplateMatch) ||
1138 !Context.hasSameType(Old->getDeclaredReturnType(),
1139 New->getDeclaredReturnType())))
1140 return true;
1141
1142 // If the function is a class member, its signature includes the
1143 // cv-qualifiers (if any) and ref-qualifier (if any) on the function itself.
1144 //
1145 // As part of this, also check whether one of the member functions
1146 // is static, in which case they are not overloads (C++
1147 // 13.1p2). While not part of the definition of the signature,
1148 // this check is important to determine whether these functions
1149 // can be overloaded.
1150 CXXMethodDecl *OldMethod = dyn_cast<CXXMethodDecl>(Old);
1151 CXXMethodDecl *NewMethod = dyn_cast<CXXMethodDecl>(New);
1152 if (OldMethod && NewMethod &&
1153 !OldMethod->isStatic() && !NewMethod->isStatic()) {
1154 if (OldMethod->getRefQualifier() != NewMethod->getRefQualifier()) {
1155 if (!UseMemberUsingDeclRules &&
1156 (OldMethod->getRefQualifier() == RQ_None ||
1157 NewMethod->getRefQualifier() == RQ_None)) {
1158 // C++0x [over.load]p2:
1159 // - Member function declarations with the same name and the same
1160 // parameter-type-list as well as member function template
1161 // declarations with the same name, the same parameter-type-list, and
1162 // the same template parameter lists cannot be overloaded if any of
1163 // them, but not all, have a ref-qualifier (8.3.5).
1164 Diag(NewMethod->getLocation(), diag::err_ref_qualifier_overload)
1165 << NewMethod->getRefQualifier() << OldMethod->getRefQualifier();
1166 Diag(OldMethod->getLocation(), diag::note_previous_declaration);
1167 }
1168 return true;
1169 }
1170
1171 // We may not have applied the implicit const for a constexpr member
1172 // function yet (because we haven't yet resolved whether this is a static
1173 // or non-static member function). Add it now, on the assumption that this
1174 // is a redeclaration of OldMethod.
1175 auto OldQuals = OldMethod->getMethodQualifiers();
1176 auto NewQuals = NewMethod->getMethodQualifiers();
1177 if (!getLangOpts().CPlusPlus14 && NewMethod->isConstexpr() &&
1178 !isa<CXXConstructorDecl>(NewMethod))
1179 NewQuals.addConst();
1180 // We do not allow overloading based off of '__restrict'.
1181 OldQuals.removeRestrict();
1182 NewQuals.removeRestrict();
1183 if (OldQuals != NewQuals)
1184 return true;
1185 }
1186
1187 // Though pass_object_size is placed on parameters and takes an argument, we
1188 // consider it to be a function-level modifier for the sake of function
1189 // identity. Either the function has one or more parameters with
1190 // pass_object_size or it doesn't.
1191 if (functionHasPassObjectSizeParams(New) !=
1192 functionHasPassObjectSizeParams(Old))
1193 return true;
1194
1195 // enable_if attributes are an order-sensitive part of the signature.
1196 for (specific_attr_iterator<EnableIfAttr>
1197 NewI = New->specific_attr_begin<EnableIfAttr>(),
1198 NewE = New->specific_attr_end<EnableIfAttr>(),
1199 OldI = Old->specific_attr_begin<EnableIfAttr>(),
1200 OldE = Old->specific_attr_end<EnableIfAttr>();
1201 NewI != NewE || OldI != OldE; ++NewI, ++OldI) {
1202 if (NewI == NewE || OldI == OldE)
1203 return true;
1204 llvm::FoldingSetNodeID NewID, OldID;
1205 NewI->getCond()->Profile(NewID, Context, true);
1206 OldI->getCond()->Profile(OldID, Context, true);
1207 if (NewID != OldID)
1208 return true;
1209 }
1210
1211 if (getLangOpts().CUDA && ConsiderCudaAttrs) {
1212 // Don't allow overloading of destructors. (In theory we could, but it
1213 // would be a giant change to clang.)
1214 if (isa<CXXDestructorDecl>(New))
1215 return false;
1216
1217 CUDAFunctionTarget NewTarget = IdentifyCUDATarget(New),
1218 OldTarget = IdentifyCUDATarget(Old);
1219 if (NewTarget == CFT_InvalidTarget)
1220 return false;
1221
1222 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-9~svn360825/tools/clang/lib/Sema/SemaOverload.cpp"
, 1222, __PRETTY_FUNCTION__))
;
1223
1224 // Allow overloading of functions with same signature and different CUDA
1225 // target attributes.
1226 return NewTarget != OldTarget;
1227 }
1228
1229 // The signatures match; this is not an overload.
1230 return false;
1231}
1232
1233/// Tries a user-defined conversion from From to ToType.
1234///
1235/// Produces an implicit conversion sequence for when a standard conversion
1236/// is not an option. See TryImplicitConversion for more information.
1237static ImplicitConversionSequence
1238TryUserDefinedConversion(Sema &S, Expr *From, QualType ToType,
1239 bool SuppressUserConversions,
1240 bool AllowExplicit,
1241 bool InOverloadResolution,
1242 bool CStyle,
1243 bool AllowObjCWritebackConversion,
1244 bool AllowObjCConversionOnExplicit) {
1245 ImplicitConversionSequence ICS;
1246
1247 if (SuppressUserConversions) {
1248 // We're not in the case above, so there is no conversion that
1249 // we can perform.
1250 ICS.setBad(BadConversionSequence::no_conversion, From, ToType);
1251 return ICS;
1252 }
1253
1254 // Attempt user-defined conversion.
1255 OverloadCandidateSet Conversions(From->getExprLoc(),
1256 OverloadCandidateSet::CSK_Normal);
1257 switch (IsUserDefinedConversion(S, From, ToType, ICS.UserDefined,
1258 Conversions, AllowExplicit,
1259 AllowObjCConversionOnExplicit)) {
1260 case OR_Success:
1261 case OR_Deleted:
1262 ICS.setUserDefined();
1263 // C++ [over.ics.user]p4:
1264 // A conversion of an expression of class type to the same class
1265 // type is given Exact Match rank, and a conversion of an
1266 // expression of class type to a base class of that type is
1267 // given Conversion rank, in spite of the fact that a copy
1268 // constructor (i.e., a user-defined conversion function) is
1269 // called for those cases.
1270 if (CXXConstructorDecl *Constructor
1271 = dyn_cast<CXXConstructorDecl>(ICS.UserDefined.ConversionFunction)) {
1272 QualType FromCanon
1273 = S.Context.getCanonicalType(From->getType().getUnqualifiedType());
1274 QualType ToCanon
1275 = S.Context.getCanonicalType(ToType).getUnqualifiedType();
1276 if (Constructor->isCopyConstructor() &&
1277 (FromCanon == ToCanon ||
1278 S.IsDerivedFrom(From->getBeginLoc(), FromCanon, ToCanon))) {
1279 // Turn this into a "standard" conversion sequence, so that it
1280 // gets ranked with standard conversion sequences.
1281 DeclAccessPair Found = ICS.UserDefined.FoundConversionFunction;
1282 ICS.setStandard();
1283 ICS.Standard.setAsIdentityConversion();
1284 ICS.Standard.setFromType(From->getType());
1285 ICS.Standard.setAllToTypes(ToType);
1286 ICS.Standard.CopyConstructor = Constructor;
1287 ICS.Standard.FoundCopyConstructor = Found;
1288 if (ToCanon != FromCanon)
1289 ICS.Standard.Second = ICK_Derived_To_Base;
1290 }
1291 }
1292 break;
1293
1294 case OR_Ambiguous:
1295 ICS.setAmbiguous();
1296 ICS.Ambiguous.setFromType(From->getType());
1297 ICS.Ambiguous.setToType(ToType);
1298 for (OverloadCandidateSet::iterator Cand = Conversions.begin();
1299 Cand != Conversions.end(); ++Cand)
1300 if (Cand->Viable)
1301 ICS.Ambiguous.addConversion(Cand->FoundDecl, Cand->Function);
1302 break;
1303
1304 // Fall through.
1305 case OR_No_Viable_Function:
1306 ICS.setBad(BadConversionSequence::no_conversion, From, ToType);
1307 break;
1308 }
1309
1310 return ICS;
1311}
1312
1313/// TryImplicitConversion - Attempt to perform an implicit conversion
1314/// from the given expression (Expr) to the given type (ToType). This
1315/// function returns an implicit conversion sequence that can be used
1316/// to perform the initialization. Given
1317///
1318/// void f(float f);
1319/// void g(int i) { f(i); }
1320///
1321/// this routine would produce an implicit conversion sequence to
1322/// describe the initialization of f from i, which will be a standard
1323/// conversion sequence containing an lvalue-to-rvalue conversion (C++
1324/// 4.1) followed by a floating-integral conversion (C++ 4.9).
1325//
1326/// Note that this routine only determines how the conversion can be
1327/// performed; it does not actually perform the conversion. As such,
1328/// it will not produce any diagnostics if no conversion is available,
1329/// but will instead return an implicit conversion sequence of kind
1330/// "BadConversion".
1331///
1332/// If @p SuppressUserConversions, then user-defined conversions are
1333/// not permitted.
1334/// If @p AllowExplicit, then explicit user-defined conversions are
1335/// permitted.
1336///
1337/// \param AllowObjCWritebackConversion Whether we allow the Objective-C
1338/// writeback conversion, which allows __autoreleasing id* parameters to
1339/// be initialized with __strong id* or __weak id* arguments.
1340static ImplicitConversionSequence
1341TryImplicitConversion(Sema &S, Expr *From, QualType ToType,
1342 bool SuppressUserConversions,
1343 bool AllowExplicit,
1344 bool InOverloadResolution,
1345 bool CStyle,
1346 bool AllowObjCWritebackConversion,
1347 bool AllowObjCConversionOnExplicit) {
1348 ImplicitConversionSequence ICS;
1349 if (IsStandardConversion(S, From, ToType, InOverloadResolution,
1350 ICS.Standard, CStyle, AllowObjCWritebackConversion)){
1351 ICS.setStandard();
1352 return ICS;
1353 }
1354
1355 if (!S.getLangOpts().CPlusPlus) {
1356 ICS.setBad(BadConversionSequence::no_conversion, From, ToType);
1357 return ICS;
1358 }
1359
1360 // C++ [over.ics.user]p4:
1361 // A conversion of an expression of class type to the same class
1362 // type is given Exact Match rank, and a conversion of an
1363 // expression of class type to a base class of that type is
1364 // given Conversion rank, in spite of the fact that a copy/move
1365 // constructor (i.e., a user-defined conversion function) is
1366 // called for those cases.
1367 QualType FromType = From->getType();
1368 if (ToType->getAs<RecordType>() && FromType->getAs<RecordType>() &&
1369 (S.Context.hasSameUnqualifiedType(FromType, ToType) ||
1370 S.IsDerivedFrom(From->getBeginLoc(), FromType, ToType))) {
1371 ICS.setStandard();
1372 ICS.Standard.setAsIdentityConversion();
1373 ICS.Standard.setFromType(FromType);
1374 ICS.Standard.setAllToTypes(ToType);
1375
1376 // We don't actually check at this point whether there is a valid
1377 // copy/move constructor, since overloading just assumes that it
1378 // exists. When we actually perform initialization, we'll find the
1379 // appropriate constructor to copy the returned object, if needed.
1380 ICS.Standard.CopyConstructor = nullptr;
1381
1382 // Determine whether this is considered a derived-to-base conversion.
1383 if (!S.Context.hasSameUnqualifiedType(FromType, ToType))
1384 ICS.Standard.Second = ICK_Derived_To_Base;
1385
1386 return ICS;
1387 }
1388
1389 return TryUserDefinedConversion(S, From, ToType, SuppressUserConversions,
1390 AllowExplicit, InOverloadResolution, CStyle,
1391 AllowObjCWritebackConversion,
1392 AllowObjCConversionOnExplicit);
1393}
1394
1395ImplicitConversionSequence
1396Sema::TryImplicitConversion(Expr *From, QualType ToType,
1397 bool SuppressUserConversions,
1398 bool AllowExplicit,
1399 bool InOverloadResolution,
1400 bool CStyle,
1401 bool AllowObjCWritebackConversion) {
1402 return ::TryImplicitConversion(*this, From, ToType,
1403 SuppressUserConversions, AllowExplicit,
1404 InOverloadResolution, CStyle,
1405 AllowObjCWritebackConversion,
1406 /*AllowObjCConversionOnExplicit=*/false);
1407}
1408
1409/// PerformImplicitConversion - Perform an implicit conversion of the
1410/// expression From to the type ToType. Returns the
1411/// converted expression. Flavor is the kind of conversion we're
1412/// performing, used in the error message. If @p AllowExplicit,
1413/// explicit user-defined conversions are permitted.
1414ExprResult
1415Sema::PerformImplicitConversion(Expr *From, QualType ToType,
1416 AssignmentAction Action, bool AllowExplicit) {
1417 ImplicitConversionSequence ICS;
1418 return PerformImplicitConversion(From, ToType, Action, AllowExplicit, ICS);
1419}
1420
1421ExprResult
1422Sema::PerformImplicitConversion(Expr *From, QualType ToType,
1423 AssignmentAction Action, bool AllowExplicit,
1424 ImplicitConversionSequence& ICS) {
1425 if (checkPlaceholderForOverload(*this, From))
1426 return ExprError();
1427
1428 // Objective-C ARC: Determine whether we will allow the writeback conversion.
1429 bool AllowObjCWritebackConversion
1430 = getLangOpts().ObjCAutoRefCount &&
1431 (Action == AA_Passing || Action == AA_Sending);
1432 if (getLangOpts().ObjC)
1433 CheckObjCBridgeRelatedConversions(From->getBeginLoc(), ToType,
1434 From->getType(), From);
1435 ICS = ::TryImplicitConversion(*this, From, ToType,
1436 /*SuppressUserConversions=*/false,
1437 AllowExplicit,
1438 /*InOverloadResolution=*/false,
1439 /*CStyle=*/false,
1440 AllowObjCWritebackConversion,
1441 /*AllowObjCConversionOnExplicit=*/false);
1442 return PerformImplicitConversion(From, ToType, ICS, Action);
1443}
1444
1445/// Determine whether the conversion from FromType to ToType is a valid
1446/// conversion that strips "noexcept" or "noreturn" off the nested function
1447/// type.
1448bool Sema::IsFunctionConversion(QualType FromType, QualType ToType,
1449 QualType &ResultTy) {
1450 if (Context.hasSameUnqualifiedType(FromType, ToType))
1451 return false;
1452
1453 // Permit the conversion F(t __attribute__((noreturn))) -> F(t)
1454 // or F(t noexcept) -> F(t)
1455 // where F adds one of the following at most once:
1456 // - a pointer
1457 // - a member pointer
1458 // - a block pointer
1459 // Changes here need matching changes in FindCompositePointerType.
1460 CanQualType CanTo = Context.getCanonicalType(ToType);
1461 CanQualType CanFrom = Context.getCanonicalType(FromType);
1462 Type::TypeClass TyClass = CanTo->getTypeClass();
1463 if (TyClass != CanFrom->getTypeClass()) return false;
1464 if (TyClass != Type::FunctionProto && TyClass != Type::FunctionNoProto) {
1465 if (TyClass == Type::Pointer) {
1466 CanTo = CanTo.getAs<PointerType>()->getPointeeType();
1467 CanFrom = CanFrom.getAs<PointerType>()->getPointeeType();
1468 } else if (TyClass == Type::BlockPointer) {
1469 CanTo = CanTo.getAs<BlockPointerType>()->getPointeeType();
1470 CanFrom = CanFrom.getAs<BlockPointerType>()->getPointeeType();
1471 } else if (TyClass == Type::MemberPointer) {
1472 auto ToMPT = CanTo.getAs<MemberPointerType>();
1473 auto FromMPT = CanFrom.getAs<MemberPointerType>();
1474 // A function pointer conversion cannot change the class of the function.
1475 if (ToMPT->getClass() != FromMPT->getClass())
1476 return false;
1477 CanTo = ToMPT->getPointeeType();
1478 CanFrom = FromMPT->getPointeeType();
1479 } else {
1480 return false;
1481 }
1482
1483 TyClass = CanTo->getTypeClass();
1484 if (TyClass != CanFrom->getTypeClass()) return false;
1485 if (TyClass != Type::FunctionProto && TyClass != Type::FunctionNoProto)
1486 return false;
1487 }
1488
1489 const auto *FromFn = cast<FunctionType>(CanFrom);
1490 FunctionType::ExtInfo FromEInfo = FromFn->getExtInfo();
1491
1492 const auto *ToFn = cast<FunctionType>(CanTo);
1493 FunctionType::ExtInfo ToEInfo = ToFn->getExtInfo();
1494
1495 bool Changed = false;
1496
1497 // Drop 'noreturn' if not present in target type.
1498 if (FromEInfo.getNoReturn() && !ToEInfo.getNoReturn()) {
1499 FromFn = Context.adjustFunctionType(FromFn, FromEInfo.withNoReturn(false));
1500 Changed = true;
1501 }
1502
1503 // Drop 'noexcept' if not present in target type.
1504 if (const auto *FromFPT = dyn_cast<FunctionProtoType>(FromFn)) {
1505 const auto *ToFPT = cast<FunctionProtoType>(ToFn);
1506 if (FromFPT->isNothrow() && !ToFPT->isNothrow()) {
1507 FromFn = cast<FunctionType>(
1508 Context.getFunctionTypeWithExceptionSpec(QualType(FromFPT, 0),
1509 EST_None)
1510 .getTypePtr());
1511 Changed = true;
1512 }
1513
1514 // Convert FromFPT's ExtParameterInfo if necessary. The conversion is valid
1515 // only if the ExtParameterInfo lists of the two function prototypes can be
1516 // merged and the merged list is identical to ToFPT's ExtParameterInfo list.
1517 SmallVector<FunctionProtoType::ExtParameterInfo, 4> NewParamInfos;
1518 bool CanUseToFPT, CanUseFromFPT;
1519 if (Context.mergeExtParameterInfo(ToFPT, FromFPT, CanUseToFPT,
1520 CanUseFromFPT, NewParamInfos) &&
1521 CanUseToFPT && !CanUseFromFPT) {
1522 FunctionProtoType::ExtProtoInfo ExtInfo = FromFPT->getExtProtoInfo();
1523 ExtInfo.ExtParameterInfos =
1524 NewParamInfos.empty() ? nullptr : NewParamInfos.data();
1525 QualType QT = Context.getFunctionType(FromFPT->getReturnType(),
1526 FromFPT->getParamTypes(), ExtInfo);
1527 FromFn = QT->getAs<FunctionType>();
1528 Changed = true;
1529 }
1530 }
1531
1532 if (!Changed)
1533 return false;
1534
1535 assert(QualType(FromFn, 0).isCanonical())((QualType(FromFn, 0).isCanonical()) ? static_cast<void>
(0) : __assert_fail ("QualType(FromFn, 0).isCanonical()", "/build/llvm-toolchain-snapshot-9~svn360825/tools/clang/lib/Sema/SemaOverload.cpp"
, 1535, __PRETTY_FUNCTION__))
;
1536 if (QualType(FromFn, 0) != CanTo) return false;
1537
1538 ResultTy = ToType;
1539 return true;
1540}
1541
1542/// Determine whether the conversion from FromType to ToType is a valid
1543/// vector conversion.
1544///
1545/// \param ICK Will be set to the vector conversion kind, if this is a vector
1546/// conversion.
1547static bool IsVectorConversion(Sema &S, QualType FromType,
1548 QualType ToType, ImplicitConversionKind &ICK) {
1549 // We need at least one of these types to be a vector type to have a vector
1550 // conversion.
1551 if (!ToType->isVectorType() && !FromType->isVectorType())
1552 return false;
1553
1554 // Identical types require no conversions.
1555 if (S.Context.hasSameUnqualifiedType(FromType, ToType))
1556 return false;
1557
1558 // There are no conversions between extended vector types, only identity.
1559 if (ToType->isExtVectorType()) {
1560 // There are no conversions between extended vector types other than the
1561 // identity conversion.
1562 if (FromType->isExtVectorType())
1563 return false;
1564
1565 // Vector splat from any arithmetic type to a vector.
1566 if (FromType->isArithmeticType()) {
1567 ICK = ICK_Vector_Splat;
1568 return true;
1569 }
1570 }
1571
1572 // We can perform the conversion between vector types in the following cases:
1573 // 1)vector types are equivalent AltiVec and GCC vector types
1574 // 2)lax vector conversions are permitted and the vector types are of the
1575 // same size
1576 if (ToType->isVectorType() && FromType->isVectorType()) {
1577 if (S.Context.areCompatibleVectorTypes(FromType, ToType) ||
1578 S.isLaxVectorConversion(FromType, ToType)) {
1579 ICK = ICK_Vector_Conversion;
1580 return true;
1581 }
1582 }
1583
1584 return false;
1585}
1586
1587static bool tryAtomicConversion(Sema &S, Expr *From, QualType ToType,
1588 bool InOverloadResolution,
1589 StandardConversionSequence &SCS,
1590 bool CStyle);
1591
1592/// IsStandardConversion - Determines whether there is a standard
1593/// conversion sequence (C++ [conv], C++ [over.ics.scs]) from the
1594/// expression From to the type ToType. Standard conversion sequences
1595/// only consider non-class types; for conversions that involve class
1596/// types, use TryImplicitConversion. If a conversion exists, SCS will
1597/// contain the standard conversion sequence required to perform this
1598/// conversion and this routine will return true. Otherwise, this
1599/// routine will return false and the value of SCS is unspecified.
1600static bool IsStandardConversion(Sema &S, Expr* From, QualType ToType,
1601 bool InOverloadResolution,
1602 StandardConversionSequence &SCS,
1603 bool CStyle,
1604 bool AllowObjCWritebackConversion) {
1605 QualType FromType = From->getType();
1606
1607 // Standard conversions (C++ [conv])
1608 SCS.setAsIdentityConversion();
1609 SCS.IncompatibleObjC = false;
1610 SCS.setFromType(FromType);
1611 SCS.CopyConstructor = nullptr;
1612
1613 // There are no standard conversions for class types in C++, so
1614 // abort early. When overloading in C, however, we do permit them.
1615 if (S.getLangOpts().CPlusPlus &&
1616 (FromType->isRecordType() || ToType->isRecordType()))
1617 return false;
1618
1619 // The first conversion can be an lvalue-to-rvalue conversion,
1620 // array-to-pointer conversion, or function-to-pointer conversion
1621 // (C++ 4p1).
1622
1623 if (FromType == S.Context.OverloadTy) {
1624 DeclAccessPair AccessPair;
1625 if (FunctionDecl *Fn
1626 = S.ResolveAddressOfOverloadedFunction(From, ToType, false,
1627 AccessPair)) {
1628 // We were able to resolve the address of the overloaded function,
1629 // so we can convert to the type of that function.
1630 FromType = Fn->getType();
1631 SCS.setFromType(FromType);
1632
1633 // we can sometimes resolve &foo<int> regardless of ToType, so check
1634 // if the type matches (identity) or we are converting to bool
1635 if (!S.Context.hasSameUnqualifiedType(
1636 S.ExtractUnqualifiedFunctionType(ToType), FromType)) {
1637 QualType resultTy;
1638 // if the function type matches except for [[noreturn]], it's ok
1639 if (!S.IsFunctionConversion(FromType,
1640 S.ExtractUnqualifiedFunctionType(ToType), resultTy))
1641 // otherwise, only a boolean conversion is standard
1642 if (!ToType->isBooleanType())
1643 return false;
1644 }
1645
1646 // Check if the "from" expression is taking the address of an overloaded
1647 // function and recompute the FromType accordingly. Take advantage of the
1648 // fact that non-static member functions *must* have such an address-of
1649 // expression.
1650 CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn);
1651 if (Method && !Method->isStatic()) {
1652 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-9~svn360825/tools/clang/lib/Sema/SemaOverload.cpp"
, 1653, __PRETTY_FUNCTION__))
1653 "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-9~svn360825/tools/clang/lib/Sema/SemaOverload.cpp"
, 1653, __PRETTY_FUNCTION__))
;
1654 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-9~svn360825/tools/clang/lib/Sema/SemaOverload.cpp"
, 1656, __PRETTY_FUNCTION__))
1655 == 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-9~svn360825/tools/clang/lib/Sema/SemaOverload.cpp"
, 1656, __PRETTY_FUNCTION__))
1656 "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-9~svn360825/tools/clang/lib/Sema/SemaOverload.cpp"
, 1656, __PRETTY_FUNCTION__))
;
1657 const Type *ClassType
1658 = S.Context.getTypeDeclType(Method->getParent()).getTypePtr();
1659 FromType = S.Context.getMemberPointerType(FromType, ClassType);
1660 } else if (isa<UnaryOperator>(From->IgnoreParens())) {
1661 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-9~svn360825/tools/clang/lib/Sema/SemaOverload.cpp"
, 1663, __PRETTY_FUNCTION__))
1662 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-9~svn360825/tools/clang/lib/Sema/SemaOverload.cpp"
, 1663, __PRETTY_FUNCTION__))
1663 "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-9~svn360825/tools/clang/lib/Sema/SemaOverload.cpp"
, 1663, __PRETTY_FUNCTION__))
;
1664 FromType = S.Context.getPointerType(FromType);
1665 }
1666
1667 // Check that we've computed the proper type after overload resolution.
1668 // FIXME: FixOverloadedFunctionReference has side-effects; we shouldn't
1669 // be calling it from within an NDEBUG block.
1670 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-9~svn360825/tools/clang/lib/Sema/SemaOverload.cpp"
, 1672, __PRETTY_FUNCTION__))
1671 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-9~svn360825/tools/clang/lib/Sema/SemaOverload.cpp"
, 1672, __PRETTY_FUNCTION__))
1672 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-9~svn360825/tools/clang/lib/Sema/SemaOverload.cpp"
, 1672, __PRETTY_FUNCTION__))
;
1673 } else {
1674 return false;
1675 }
1676 }
1677 // Lvalue-to-rvalue conversion (C++11 4.1):
1678 // A glvalue (3.10) of a non-function, non-array type T can
1679 // be converted to a prvalue.
1680 bool argIsLValue = From->isGLValue();
1681 if (argIsLValue &&
1682 !FromType->isFunctionType() && !FromType->isArrayType() &&
1683 S.Context.getCanonicalType(FromType) != S.Context.OverloadTy) {
1684 SCS.First = ICK_Lvalue_To_Rvalue;
1685
1686 // C11 6.3.2.1p2:
1687 // ... if the lvalue has atomic type, the value has the non-atomic version
1688 // of the type of the lvalue ...
1689 if (const AtomicType *Atomic = FromType->getAs<AtomicType>())
1690 FromType = Atomic->getValueType();
1691
1692 // If T is a non-class type, the type of the rvalue is the
1693 // cv-unqualified version of T. Otherwise, the type of the rvalue
1694 // is T (C++ 4.1p1). C++ can't get here with class types; in C, we
1695 // just strip the qualifiers because they don't matter.
1696 FromType = FromType.getUnqualifiedType();
1697 } else if (FromType->isArrayType()) {
1698 // Array-to-pointer conversion (C++ 4.2)
1699 SCS.First = ICK_Array_To_Pointer;
1700
1701 // An lvalue or rvalue of type "array of N T" or "array of unknown
1702 // bound of T" can be converted to an rvalue of type "pointer to
1703 // T" (C++ 4.2p1).
1704 FromType = S.Context.getArrayDecayedType(FromType);
1705
1706 if (S.IsStringLiteralToNonConstPointerConversion(From, ToType)) {
1707 // This conversion is deprecated in C++03 (D.4)
1708 SCS.DeprecatedStringLiteralToCharPtr = true;
1709
1710 // For the purpose of ranking in overload resolution
1711 // (13.3.3.1.1), this conversion is considered an
1712 // array-to-pointer conversion followed by a qualification
1713 // conversion (4.4). (C++ 4.2p2)
1714 SCS.Second = ICK_Identity;
1715 SCS.Third = ICK_Qualification;
1716 SCS.QualificationIncludesObjCLifetime = false;
1717 SCS.setAllToTypes(FromType);
1718 return true;
1719 }
1720 } else if (FromType->isFunctionType() && argIsLValue) {
1721 // Function-to-pointer conversion (C++ 4.3).
1722 SCS.First = ICK_Function_To_Pointer;
1723
1724 if (auto *DRE = dyn_cast<DeclRefExpr>(From->IgnoreParenCasts()))
1725 if (auto *FD = dyn_cast<FunctionDecl>(DRE->getDecl()))
1726 if (!S.checkAddressOfFunctionIsAvailable(FD))
1727 return false;
1728
1729 // An lvalue of function type T can be converted to an rvalue of
1730 // type "pointer to T." The result is a pointer to the
1731 // function. (C++ 4.3p1).
1732 FromType = S.Context.getPointerType(FromType);
1733 } else {
1734 // We don't require any conversions for the first step.
1735 SCS.First = ICK_Identity;
1736 }
1737 SCS.setToType(0, FromType);
1738
1739 // The second conversion can be an integral promotion, floating
1740 // point promotion, integral conversion, floating point conversion,
1741 // floating-integral conversion, pointer conversion,
1742 // pointer-to-member conversion, or boolean conversion (C++ 4p1).
1743 // For overloading in C, this can also be a "compatible-type"
1744 // conversion.
1745 bool IncompatibleObjC = false;
1746 ImplicitConversionKind SecondICK = ICK_Identity;
1747 if (S.Context.hasSameUnqualifiedType(FromType, ToType)) {
1748 // The unqualified versions of the types are the same: there's no
1749 // conversion to do.
1750 SCS.Second = ICK_Identity;
1751 } else if (S.IsIntegralPromotion(From, FromType, ToType)) {
1752 // Integral promotion (C++ 4.5).
1753 SCS.Second = ICK_Integral_Promotion;
1754 FromType = ToType.getUnqualifiedType();
1755 } else if (S.IsFloatingPointPromotion(FromType, ToType)) {
1756 // Floating point promotion (C++ 4.6).
1757 SCS.Second = ICK_Floating_Promotion;
1758 FromType = ToType.getUnqualifiedType();
1759 } else if (S.IsComplexPromotion(FromType, ToType)) {
1760 // Complex promotion (Clang extension)
1761 SCS.Second = ICK_Complex_Promotion;
1762 FromType = ToType.getUnqualifiedType();
1763 } else if (ToType->isBooleanType() &&
1764 (FromType->isArithmeticType() ||
1765 FromType->isAnyPointerType() ||
1766 FromType->isBlockPointerType() ||
1767 FromType->isMemberPointerType() ||
1768 FromType->isNullPtrType())) {
1769 // Boolean conversions (C++ 4.12).
1770 SCS.Second = ICK_Boolean_Conversion;
1771 FromType = S.Context.BoolTy;
1772 } else if (FromType->isIntegralOrUnscopedEnumerationType() &&
1773 ToType->isIntegralType(S.Context)) {
1774 // Integral conversions (C++ 4.7).
1775 SCS.Second = ICK_Integral_Conversion;
1776 FromType = ToType.getUnqualifiedType();
1777 } else if (FromType->isAnyComplexType() && ToType->isAnyComplexType()) {
1778 // Complex conversions (C99 6.3.1.6)
1779 SCS.Second = ICK_Complex_Conversion;
1780 FromType = ToType.getUnqualifiedType();
1781 } else if ((FromType->isAnyComplexType() && ToType->isArithmeticType()) ||
1782 (ToType->isAnyComplexType() && FromType->isArithmeticType())) {
1783 // Complex-real conversions (C99 6.3.1.7)
1784 SCS.Second = ICK_Complex_Real;
1785 FromType = ToType.getUnqualifiedType();
1786 } else if (FromType->isRealFloatingType() && ToType->isRealFloatingType()) {
1787 // FIXME: disable conversions between long double and __float128 if
1788 // their representation is different until there is back end support
1789 // We of course allow this conversion if long double is really double.
1790 if (&S.Context.getFloatTypeSemantics(FromType) !=
1791 &S.Context.getFloatTypeSemantics(ToType)) {
1792 bool Float128AndLongDouble = ((FromType == S.Context.Float128Ty &&
1793 ToType == S.Context.LongDoubleTy) ||
1794 (FromType == S.Context.LongDoubleTy &&
1795 ToType == S.Context.Float128Ty));
1796 if (Float128AndLongDouble &&
1797 (&S.Context.getFloatTypeSemantics(S.Context.LongDoubleTy) ==
1798 &llvm::APFloat::PPCDoubleDouble()))
1799 return false;
1800 }
1801 // Floating point conversions (C++ 4.8).
1802 SCS.Second = ICK_Floating_Conversion;
1803 FromType = ToType.getUnqualifiedType();
1804 } else if ((FromType->isRealFloatingType() &&
1805 ToType->isIntegralType(S.Context)) ||
1806 (FromType->isIntegralOrUnscopedEnumerationType() &&
1807 ToType->isRealFloatingType())) {
1808 // Floating-integral conversions (C++ 4.9).
1809 SCS.Second = ICK_Floating_Integral;
1810 FromType = ToType.getUnqualifiedType();
1811 } else if (S.IsBlockPointerConversion(FromType, ToType, FromType)) {
1812 SCS.Second = ICK_Block_Pointer_Conversion;
1813 } else if (AllowObjCWritebackConversion &&
1814 S.isObjCWritebackConversion(FromType, ToType, FromType)) {
1815 SCS.Second = ICK_Writeback_Conversion;
1816 } else if (S.IsPointerConversion(From, FromType, ToType, InOverloadResolution,
1817 FromType, IncompatibleObjC)) {
1818 // Pointer conversions (C++ 4.10).
1819 SCS.Second = ICK_Pointer_Conversion;
1820 SCS.IncompatibleObjC = IncompatibleObjC;
1821 FromType = FromType.getUnqualifiedType();
1822 } else if (S.IsMemberPointerConversion(From, FromType, ToType,
1823 InOverloadResolution, FromType)) {
1824 // Pointer to member conversions (4.11).
1825 SCS.Second = ICK_Pointer_Member;
1826 } else if (IsVectorConversion(S, FromType, ToType, SecondICK)) {
1827 SCS.Second = SecondICK;
1828 FromType = ToType.getUnqualifiedType();
1829 } else if (!S.getLangOpts().CPlusPlus &&
1830 S.Context.typesAreCompatible(ToType, FromType)) {
1831 // Compatible conversions (Clang extension for C function overloading)
1832 SCS.Second = ICK_Compatible_Conversion;
1833 FromType = ToType.getUnqualifiedType();
1834 } else if (IsTransparentUnionStandardConversion(S, From, ToType,
1835 InOverloadResolution,
1836 SCS, CStyle)) {
1837 SCS.Second = ICK_TransparentUnionConversion;
1838 FromType = ToType;
1839 } else if (tryAtomicConversion(S, From, ToType, InOverloadResolution, SCS,
1840 CStyle)) {
1841 // tryAtomicConversion has updated the standard conversion sequence
1842 // appropriately.
1843 return true;
1844 } else if (ToType->isEventT() &&
1845 From->isIntegerConstantExpr(S.getASTContext()) &&
1846 From->EvaluateKnownConstInt(S.getASTContext()) == 0) {
1847 SCS.Second = ICK_Zero_Event_Conversion;
1848 FromType = ToType;
1849 } else if (ToType->isQueueT() &&
1850 From->isIntegerConstantExpr(S.getASTContext()) &&
1851 (From->EvaluateKnownConstInt(S.getASTContext()) == 0)) {
1852 SCS.Second = ICK_Zero_Queue_Conversion;
1853 FromType = ToType;
1854 } else {
1855 // No second conversion required.
1856 SCS.Second = ICK_Identity;
1857 }
1858 SCS.setToType(1, FromType);
1859
1860 // The third conversion can be a function pointer conversion or a
1861 // qualification conversion (C++ [conv.fctptr], [conv.qual]).
1862 bool ObjCLifetimeConversion;
1863 if (S.IsFunctionConversion(FromType, ToType, FromType)) {
1864 // Function pointer conversions (removing 'noexcept') including removal of
1865 // 'noreturn' (Clang extension).
1866 SCS.Third = ICK_Function_Conversion;
1867 } else if (S.IsQualificationConversion(FromType, ToType, CStyle,
1868 ObjCLifetimeConversion)) {
1869 SCS.Third = ICK_Qualification;
1870 SCS.QualificationIncludesObjCLifetime = ObjCLifetimeConversion;
1871 FromType = ToType;
1872 } else {
1873 // No conversion required
1874 SCS.Third = ICK_Identity;
1875 }
1876
1877 // C++ [over.best.ics]p6:
1878 // [...] Any difference in top-level cv-qualification is
1879 // subsumed by the initialization itself and does not constitute
1880 // a conversion. [...]
1881 QualType CanonFrom = S.Context.getCanonicalType(FromType);
1882 QualType CanonTo = S.Context.getCanonicalType(ToType);
1883 if (CanonFrom.getLocalUnqualifiedType()
1884 == CanonTo.getLocalUnqualifiedType() &&
1885 CanonFrom.getLocalQualifiers() != CanonTo.getLocalQualifiers()) {
1886 FromType = ToType;
1887 CanonFrom = CanonTo;
1888 }
1889
1890 SCS.setToType(2, FromType);
1891
1892 if (CanonFrom == CanonTo)
1893 return true;
1894
1895 // If we have not converted the argument type to the parameter type,
1896 // this is a bad conversion sequence, unless we're resolving an overload in C.
1897 if (S.getLangOpts().CPlusPlus || !InOverloadResolution)
1898 return false;
1899
1900 ExprResult ER = ExprResult{From};
1901 Sema::AssignConvertType Conv =
1902 S.CheckSingleAssignmentConstraints(ToType, ER,
1903 /*Diagnose=*/false,
1904 /*DiagnoseCFAudited=*/false,
1905 /*ConvertRHS=*/false);
1906 ImplicitConversionKind SecondConv;
1907 switch (Conv) {
1908 case Sema::Compatible:
1909 SecondConv = ICK_C_Only_Conversion;
1910 break;
1911 // For our purposes, discarding qualifiers is just as bad as using an
1912 // incompatible pointer. Note that an IncompatiblePointer conversion can drop
1913 // qualifiers, as well.
1914 case Sema::CompatiblePointerDiscardsQualifiers:
1915 case Sema::IncompatiblePointer:
1916 case Sema::IncompatiblePointerSign:
1917 SecondConv = ICK_Incompatible_Pointer_Conversion;
1918 break;
1919 default:
1920 return false;
1921 }
1922
1923 // First can only be an lvalue conversion, so we pretend that this was the
1924 // second conversion. First should already be valid from earlier in the
1925 // function.
1926 SCS.Second = SecondConv;
1927 SCS.setToType(1, ToType);
1928
1929 // Third is Identity, because Second should rank us worse than any other
1930 // conversion. This could also be ICK_Qualification, but it's simpler to just
1931 // lump everything in with the second conversion, and we don't gain anything
1932 // from making this ICK_Qualification.
1933 SCS.Third = ICK_Identity;
1934 SCS.setToType(2, ToType);
1935 return true;
1936}
1937
1938static bool
1939IsTransparentUnionStandardConversion(Sema &S, Expr* From,
1940 QualType &ToType,
1941 bool InOverloadResolution,
1942 StandardConversionSequence &SCS,
1943 bool CStyle) {
1944
1945 const RecordType *UT = ToType->getAsUnionType();
1946 if (!UT || !UT->getDecl()->hasAttr<TransparentUnionAttr>())
1947 return false;
1948 // The field to initialize within the transparent union.
1949 RecordDecl *UD = UT->getDecl();
1950 // It's compatible if the expression matches any of the fields.
1951 for (const auto *it : UD->fields()) {
1952 if (IsStandardConversion(S, From, it->getType(), InOverloadResolution, SCS,
1953 CStyle, /*ObjCWritebackConversion=*/false)) {
1954 ToType = it->getType();
1955 return true;
1956 }
1957 }
1958 return false;
1959}
1960
1961/// IsIntegralPromotion - Determines whether the conversion from the
1962/// expression From (whose potentially-adjusted type is FromType) to
1963/// ToType is an integral promotion (C++ 4.5). If so, returns true and
1964/// sets PromotedType to the promoted type.
1965bool Sema::IsIntegralPromotion(Expr *From, QualType FromType, QualType ToType) {
1966 const BuiltinType *To = ToType->getAs<BuiltinType>();
1967 // All integers are built-in.
1968 if (!To) {
1969 return false;
1970 }
1971
1972 // An rvalue of type char, signed char, unsigned char, short int, or
1973 // unsigned short int can be converted to an rvalue of type int if
1974 // int can represent all the values of the source type; otherwise,
1975 // the source rvalue can be converted to an rvalue of type unsigned
1976 // int (C++ 4.5p1).
1977 if (FromType->isPromotableIntegerType() && !FromType->isBooleanType() &&
1978 !FromType->isEnumeralType()) {
1979 if (// We can promote any signed, promotable integer type to an int
1980 (FromType->isSignedIntegerType() ||
1981 // We can promote any unsigned integer type whose size is
1982 // less than int to an int.
1983 Context.getTypeSize(FromType) < Context.getTypeSize(ToType))) {
1984 return To->getKind() == BuiltinType::Int;
1985 }
1986
1987 return To->getKind() == BuiltinType::UInt;
1988 }
1989
1990 // C++11 [conv.prom]p3:
1991 // A prvalue of an unscoped enumeration type whose underlying type is not
1992 // fixed (7.2) can be converted to an rvalue a prvalue of the first of the
1993 // following types that can represent all the values of the enumeration
1994 // (i.e., the values in the range bmin to bmax as described in 7.2): int,
1995 // unsigned int, long int, unsigned long int, long long int, or unsigned
1996 // long long int. If none of the types in that list can represent all the
1997 // values of the enumeration, an rvalue a prvalue of an unscoped enumeration
1998 // type can be converted to an rvalue a prvalue of the extended integer type
1999 // with lowest integer conversion rank (4.13) greater than the rank of long
2000 // long in which all the values of the enumeration can be represented. If
2001 // there are two such extended types, the signed one is chosen.
2002 // C++11 [conv.prom]p4:
2003 // A prvalue of an unscoped enumeration type whose underlying type is fixed
2004 // can be converted to a prvalue of its underlying type. Moreover, if
2005 // integral promotion can be applied to its underlying type, a prvalue of an
2006 // unscoped enumeration type whose underlying type is fixed can also be
2007 // converted to a prvalue of the promoted underlying type.
2008 if (const EnumType *FromEnumType = FromType->getAs<EnumType>()) {
2009 // C++0x 7.2p9: Note that this implicit enum to int conversion is not
2010 // provided for a scoped enumeration.
2011 if (FromEnumType->getDecl()->isScoped())
2012 return false;
2013
2014 // We can perform an integral promotion to the underlying type of the enum,
2015 // even if that's not the promoted type. Note that the check for promoting
2016 // the underlying type is based on the type alone, and does not consider
2017 // the bitfield-ness of the actual source expression.
2018 if (FromEnumType->getDecl()->isFixed()) {
2019 QualType Underlying = FromEnumType->getDecl()->getIntegerType();
2020 return Context.hasSameUnqualifiedType(Underlying, ToType) ||
2021 IsIntegralPromotion(nullptr, Underlying, ToType);
2022 }
2023
2024 // We have already pre-calculated the promotion type, so this is trivial.
2025 if (ToType->isIntegerType() &&
2026 isCompleteType(From->getBeginLoc(), FromType))
2027 return Context.hasSameUnqualifiedType(
2028 ToType, FromEnumType->getDecl()->getPromotionType());
2029
2030 // C++ [conv.prom]p5:
2031 // If the bit-field has an enumerated type, it is treated as any other
2032 // value of that type for promotion purposes.
2033 //
2034 // ... so do not fall through into the bit-field checks below in C++.
2035 if (getLangOpts().CPlusPlus)
2036 return false;
2037 }
2038
2039 // C++0x [conv.prom]p2:
2040 // A prvalue of type char16_t, char32_t, or wchar_t (3.9.1) can be converted
2041 // to an rvalue a prvalue of the first of the following types that can
2042 // represent all the values of its underlying type: int, unsigned int,
2043 // long int, unsigned long int, long long int, or unsigned long long int.
2044 // If none of the types in that list can represent all the values of its
2045 // underlying type, an rvalue a prvalue of type char16_t, char32_t,
2046 // or wchar_t can be converted to an rvalue a prvalue of its underlying
2047 // type.
2048 if (FromType->isAnyCharacterType() && !FromType->isCharType() &&
2049 ToType->isIntegerType()) {
2050 // Determine whether the type we're converting from is signed or
2051 // unsigned.
2052 bool FromIsSigned = FromType->isSignedIntegerType();
2053 uint64_t FromSize = Context.getTypeSize(FromType);
2054
2055 // The types we'll try to promote to, in the appropriate
2056 // order. Try each of these types.
2057 QualType PromoteTypes[6] = {
2058 Context.IntTy, Context.UnsignedIntTy,
2059 Context.LongTy, Context.UnsignedLongTy ,
2060 Context.LongLongTy, Context.UnsignedLongLongTy
2061 };
2062 for (int Idx = 0; Idx < 6; ++Idx) {
2063 uint64_t ToSize = Context.getTypeSize(PromoteTypes[Idx]);
2064 if (FromSize < ToSize ||
2065 (FromSize == ToSize &&
2066 FromIsSigned == PromoteTypes[Idx]->isSignedIntegerType())) {
2067 // We found the type that we can promote to. If this is the
2068 // type we wanted, we have a promotion. Otherwise, no
2069 // promotion.
2070 return Context.hasSameUnqualifiedType(ToType, PromoteTypes[Idx]);
2071 }
2072 }
2073 }
2074
2075 // An rvalue for an integral bit-field (9.6) can be converted to an
2076 // rvalue of type int if int can represent all the values of the
2077 // bit-field; otherwise, it can be converted to unsigned int if
2078 // unsigned int can represent all the values of the bit-field. If
2079 // the bit-field is larger yet, no integral promotion applies to
2080 // it. If the bit-field has an enumerated type, it is treated as any
2081 // other value of that type for promotion purposes (C++ 4.5p3).
2082 // FIXME: We should delay checking of bit-fields until we actually perform the
2083 // conversion.
2084 //
2085 // FIXME: In C, only bit-fields of types _Bool, int, or unsigned int may be
2086 // promoted, per C11 6.3.1.1/2. We promote all bit-fields (including enum
2087 // bit-fields and those whose underlying type is larger than int) for GCC
2088 // compatibility.
2089 if (From) {
2090 if (FieldDecl *MemberDecl = From->getSourceBitField()) {
2091 llvm::APSInt BitWidth;
2092 if (FromType->isIntegralType(Context) &&
2093 MemberDecl->getBitWidth()->isIntegerConstantExpr(BitWidth, Context)) {
2094 llvm::APSInt ToSize(BitWidth.getBitWidth(), BitWidth.isUnsigned());
2095 ToSize = Context.getTypeSize(ToType);
2096
2097 // Are we promoting to an int from a bitfield that fits in an int?
2098 if (BitWidth < ToSize ||
2099 (FromType->isSignedIntegerType() && BitWidth <= ToSize)) {
2100 return To->getKind() == BuiltinType::Int;
2101 }
2102
2103 // Are we promoting to an unsigned int from an unsigned bitfield
2104 // that fits into an unsigned int?
2105 if (FromType->isUnsignedIntegerType() && BitWidth <= ToSize) {
2106 return To->getKind() == BuiltinType::UInt;
2107 }
2108
2109 return false;
2110 }
2111 }
2112 }
2113
2114 // An rvalue of type bool can be converted to an rvalue of type int,
2115 // with false becoming zero and true becoming one (C++ 4.5p4).
2116 if (FromType->isBooleanType() && To->getKind() == BuiltinType::Int) {
2117 return true;
2118 }
2119
2120 return false;
2121}
2122
2123/// IsFloatingPointPromotion - Determines whether the conversion from
2124/// FromType to ToType is a floating point promotion (C++ 4.6). If so,
2125/// returns true and sets PromotedType to the promoted type.
2126bool Sema::IsFloatingPointPromotion(QualType FromType, QualType ToType) {
2127 if (const BuiltinType *FromBuiltin = FromType->getAs<BuiltinType>())
2128 if (const BuiltinType *ToBuiltin = ToType->getAs<BuiltinType>()) {
2129 /// An rvalue of type float can be converted to an rvalue of type
2130 /// double. (C++ 4.6p1).
2131 if (FromBuiltin->getKind() == BuiltinType::Float &&
2132 ToBuiltin->getKind() == BuiltinType::Double)
2133 return true;
2134
2135 // C99 6.3.1.5p1:
2136 // When a float is promoted to double or long double, or a
2137 // double is promoted to long double [...].
2138 if (!getLangOpts().CPlusPlus &&
2139 (FromBuiltin->getKind() == BuiltinType::Float ||
2140 FromBuiltin->getKind() == BuiltinType::Double) &&
2141 (ToBuiltin->getKind() == BuiltinType::LongDouble ||
2142 ToBuiltin->getKind() == BuiltinType::Float128))
2143 return true;
2144
2145 // Half can be promoted to float.
2146 if (!getLangOpts().NativeHalfType &&
2147 FromBuiltin->getKind() == BuiltinType::Half &&
2148 ToBuiltin->getKind() == BuiltinType::Float)
2149 return true;
2150 }
2151
2152 return false;
2153}
2154
2155/// Determine if a conversion is a complex promotion.
2156///
2157/// A complex promotion is defined as a complex -> complex conversion
2158/// where the conversion between the underlying real types is a
2159/// floating-point or integral promotion.
2160bool Sema::IsComplexPromotion(QualType FromType, QualType ToType) {
2161 const ComplexType *FromComplex = FromType->getAs<ComplexType>();
2162 if (!FromComplex)
2163 return false;
2164
2165 const ComplexType *ToComplex = ToType->getAs<ComplexType>();
2166 if (!ToComplex)
2167 return false;
2168
2169 return IsFloatingPointPromotion(FromComplex->getElementType(),
2170 ToComplex->getElementType()) ||
2171 IsIntegralPromotion(nullptr, FromComplex->getElementType(),
2172 ToComplex->getElementType());
2173}
2174
2175/// BuildSimilarlyQualifiedPointerType - In a pointer conversion from
2176/// the pointer type FromPtr to a pointer to type ToPointee, with the
2177/// same type qualifiers as FromPtr has on its pointee type. ToType,
2178/// if non-empty, will be a pointer to ToType that may or may not have
2179/// the right set of qualifiers on its pointee.
2180///
2181static QualType
2182BuildSimilarlyQualifiedPointerType(const Type *FromPtr,
2183 QualType ToPointee, QualType ToType,
2184 ASTContext &Context,
2185 bool StripObjCLifetime = false) {
2186 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-9~svn360825/tools/clang/lib/Sema/SemaOverload.cpp"
, 2188, __PRETTY_FUNCTION__))
2187 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-9~svn360825/tools/clang/lib/Sema/SemaOverload.cpp"
, 2188, __PRETTY_FUNCTION__))
2188 "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-9~svn360825/tools/clang/lib/Sema/SemaOverload.cpp"
, 2188, __PRETTY_FUNCTION__))
;
2189
2190 /// Conversions to 'id' subsume cv-qualifier conversions.
2191 if (ToType->isObjCIdType() || ToType->isObjCQualifiedIdType())
2192 return ToType.getUnqualifiedType();
2193
2194 QualType CanonFromPointee
2195 = Context.getCanonicalType(FromPtr->getPointeeType());
2196 QualType CanonToPointee = Context.getCanonicalType(ToPointee);
2197 Qualifiers Quals = CanonFromPointee.getQualifiers();
2198
2199 if (StripObjCLifetime)
2200 Quals.removeObjCLifetime();
2201
2202 // Exact qualifier match -> return the pointer type we're converting to.
2203 if (CanonToPointee.getLocalQualifiers() == Quals) {
2204 // ToType is exactly what we need. Return it.
2205 if (!ToType.isNull())
2206 return ToType.getUnqualifiedType();
2207
2208 // Build a pointer to ToPointee. It has the right qualifiers
2209 // already.
2210 if (isa<ObjCObjectPointerType>(ToType))
2211 return Context.getObjCObjectPointerType(ToPointee);
2212 return Context.getPointerType(ToPointee);
2213 }
2214
2215 // Just build a canonical type that has the right qualifiers.
2216 QualType QualifiedCanonToPointee
2217 = Context.getQualifiedType(CanonToPointee.getLocalUnqualifiedType(), Quals);
2218
2219 if (isa<ObjCObjectPointerType>(ToType))
2220 return Context.getObjCObjectPointerType(QualifiedCanonToPointee);
2221 return Context.getPointerType(QualifiedCanonToPointee);
2222}
2223
2224static bool isNullPointerConstantForConversion(Expr *Expr,
2225 bool InOverloadResolution,
2226 ASTContext &Context) {
2227 // Handle value-dependent integral null pointer constants correctly.
2228 // http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#903
2229 if (Expr->isValueDependent() && !Expr->isTypeDependent() &&
2230 Expr->getType()->isIntegerType() && !Expr->getType()->isEnumeralType())
2231 return !InOverloadResolution;
2232
2233 return Expr->isNullPointerConstant(Context,
2234 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull
2235 : Expr::NPC_ValueDependentIsNull);
2236}
2237
2238/// IsPointerConversion - Determines whether the conversion of the
2239/// expression From, which has the (possibly adjusted) type FromType,
2240/// can be converted to the type ToType via a pointer conversion (C++
2241/// 4.10). If so, returns true and places the converted type (that
2242/// might differ from ToType in its cv-qualifiers at some level) into
2243/// ConvertedType.
2244///
2245/// This routine also supports conversions to and from block pointers
2246/// and conversions with Objective-C's 'id', 'id<protocols...>', and
2247/// pointers to interfaces. FIXME: Once we've determined the
2248/// appropriate overloading rules for Objective-C, we may want to
2249/// split the Objective-C checks into a different routine; however,
2250/// GCC seems to consider all of these conversions to be pointer
2251/// conversions, so for now they live here. IncompatibleObjC will be
2252/// set if the conversion is an allowed Objective-C conversion that
2253/// should result in a warning.
2254bool Sema::IsPointerConversion(Expr *From, QualType FromType, QualType ToType,
2255 bool InOverloadResolution,
2256 QualType& ConvertedType,
2257 bool &IncompatibleObjC) {
2258 IncompatibleObjC = false;
2259 if (isObjCPointerConversion(FromType, ToType, ConvertedType,
2260 IncompatibleObjC))
2261 return true;
2262
2263 // Conversion from a null pointer constant to any Objective-C pointer type.
2264 if (ToType->isObjCObjectPointerType() &&
2265 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) {
2266 ConvertedType = ToType;
2267 return true;
2268 }
2269
2270 // Blocks: Block pointers can be converted to void*.
2271 if (FromType->isBlockPointerType() && ToType->isPointerType() &&
2272 ToType->getAs<PointerType>()->getPointeeType()->isVoidType()) {
2273 ConvertedType = ToType;
2274 return true;
2275 }
2276 // Blocks: A null pointer constant can be converted to a block
2277 // pointer type.
2278 if (ToType->isBlockPointerType() &&
2279 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) {
2280 ConvertedType = ToType;
2281 return true;
2282 }
2283
2284 // If the left-hand-side is nullptr_t, the right side can be a null
2285 // pointer constant.
2286 if (ToType->isNullPtrType() &&
2287 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) {
2288 ConvertedType = ToType;
2289 return true;
2290 }
2291
2292 const PointerType* ToTypePtr = ToType->getAs<PointerType>();
2293 if (!ToTypePtr)
2294 return false;
2295
2296 // A null pointer constant can be converted to a pointer type (C++ 4.10p1).
2297 if (isNullPointerConstantForConversion(From, InOverloadResolution, Context)) {
2298 ConvertedType = ToType;
2299 return true;
2300 }
2301
2302 // Beyond this point, both types need to be pointers
2303 // , including objective-c pointers.
2304 QualType ToPointeeType = ToTypePtr->getPointeeType();
2305 if (FromType->isObjCObjectPointerType() && ToPointeeType->isVoidType() &&
2306 !getLangOpts().ObjCAutoRefCount) {
2307 ConvertedType = BuildSimilarlyQualifiedPointerType(
2308 FromType->getAs<ObjCObjectPointerType>(),
2309 ToPointeeType,
2310 ToType, Context);
2311 return true;
2312 }
2313 const PointerType *FromTypePtr = FromType->getAs<PointerType>();
2314 if (!FromTypePtr)
2315 return false;
2316
2317 QualType FromPointeeType = FromTypePtr->getPointeeType();
2318
2319 // If the unqualified pointee types are the same, this can't be a
2320 // pointer conversion, so don't do all of the work below.
2321 if (Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType))
2322 return false;
2323
2324 // An rvalue of type "pointer to cv T," where T is an object type,
2325 // can be converted to an rvalue of type "pointer to cv void" (C++
2326 // 4.10p2).
2327 if (FromPointeeType->isIncompleteOrObjectType() &&
2328 ToPointeeType->isVoidType()) {
2329 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr,
2330 ToPointeeType,
2331 ToType, Context,
2332 /*StripObjCLifetime=*/true);
2333 return true;
2334 }
2335
2336 // MSVC allows implicit function to void* type conversion.
2337 if (getLangOpts().MSVCCompat && FromPointeeType->isFunctionType() &&
2338 ToPointeeType->isVoidType()) {
2339 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr,
2340 ToPointeeType,
2341 ToType, Context);
2342 return true;
2343 }
2344
2345 // When we're overloading in C, we allow a special kind of pointer
2346 // conversion for compatible-but-not-identical pointee types.
2347 if (!getLangOpts().CPlusPlus &&
2348 Context.typesAreCompatible(FromPointeeType, ToPointeeType)) {
2349 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr,
2350 ToPointeeType,
2351 ToType, Context);
2352 return true;
2353 }
2354
2355 // C++ [conv.ptr]p3:
2356 //
2357 // An rvalue of type "pointer to cv D," where D is a class type,
2358 // can be converted to an rvalue of type "pointer to cv B," where
2359 // B is a base class (clause 10) of D. If B is an inaccessible
2360 // (clause 11) or ambiguous (10.2) base class of D, a program that
2361 // necessitates this conversion is ill-formed. The result of the
2362 // conversion is a pointer to the base class sub-object of the
2363 // derived class object. The null pointer value is converted to
2364 // the null pointer value of the destination type.
2365 //
2366 // Note that we do not check for ambiguity or inaccessibility
2367 // here. That is handled by CheckPointerConversion.
2368 if (getLangOpts().CPlusPlus && FromPointeeType->isRecordType() &&
2369 ToPointeeType->isRecordType() &&
2370 !Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType) &&
2371 IsDerivedFrom(From->getBeginLoc(), FromPointeeType, ToPointeeType)) {
2372 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr,
2373 ToPointeeType,
2374 ToType, Context);
2375 return true;
2376 }
2377
2378 if (FromPointeeType->isVectorType() && ToPointeeType->isVectorType() &&
2379 Context.areCompatibleVectorTypes(FromPointeeType, ToPointeeType)) {
2380 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr,
2381 ToPointeeType,
2382 ToType, Context);
2383 return true;
2384 }
2385
2386 return false;
2387}
2388
2389/// Adopt the given qualifiers for the given type.
2390static QualType AdoptQualifiers(ASTContext &Context, QualType T, Qualifiers Qs){
2391 Qualifiers TQs = T.getQualifiers();
2392
2393 // Check whether qualifiers already match.
2394 if (TQs == Qs)
2395 return T;
2396
2397 if (Qs.compatiblyIncludes(TQs))
2398 return Context.getQualifiedType(T, Qs);
2399
2400 return Context.getQualifiedType(T.getUnqualifiedType(), Qs);
2401}
2402
2403/// isObjCPointerConversion - Determines whether this is an
2404/// Objective-C pointer conversion. Subroutine of IsPointerConversion,
2405/// with the same arguments and return values.
2406bool Sema::isObjCPointerConversion(QualType FromType, QualType ToType,
2407 QualType& ConvertedType,
2408 bool &IncompatibleObjC) {
2409 if (!getLangOpts().ObjC)
2410 return false;
2411
2412 // The set of qualifiers on the type we're converting from.
2413 Qualifiers FromQualifiers = FromType.getQualifiers();
2414
2415 // First, we handle all conversions on ObjC object pointer types.
2416 const ObjCObjectPointerType* ToObjCPtr =
2417 ToType->getAs<ObjCObjectPointerType>();
2418 const ObjCObjectPointerType *FromObjCPtr =
2419 FromType->getAs<ObjCObjectPointerType>();
2420
2421 if (ToObjCPtr && FromObjCPtr) {
2422 // If the pointee types are the same (ignoring qualifications),
2423 // then this is not a pointer conversion.
2424 if (Context.hasSameUnqualifiedType(ToObjCPtr->getPointeeType(),
2425 FromObjCPtr->getPointeeType()))
2426 return false;
2427
2428 // Conversion between Objective-C pointers.
2429 if (Context.canAssignObjCInterfaces(ToObjCPtr, FromObjCPtr)) {
2430 const ObjCInterfaceType* LHS = ToObjCPtr->getInterfaceType();
2431 const ObjCInterfaceType* RHS = FromObjCPtr->getInterfaceType();
2432 if (getLangOpts().CPlusPlus && LHS && RHS &&
2433 !ToObjCPtr->getPointeeType().isAtLeastAsQualifiedAs(
2434 FromObjCPtr->getPointeeType()))
2435 return false;
2436 ConvertedType = BuildSimilarlyQualifiedPointerType(FromObjCPtr,
2437 ToObjCPtr->getPointeeType(),
2438 ToType, Context);
2439 ConvertedType = AdoptQualifiers(Context, ConvertedType, FromQualifiers);
2440 return true;
2441 }
2442
2443 if (Context.canAssignObjCInterfaces(FromObjCPtr, ToObjCPtr)) {
2444 // Okay: this is some kind of implicit downcast of Objective-C
2445 // interfaces, which is permitted. However, we're going to
2446 // complain about it.
2447 IncompatibleObjC = true;
2448 ConvertedType = BuildSimilarlyQualifiedPointerType(FromObjCPtr,
2449 ToObjCPtr->getPointeeType(),
2450 ToType, Context);
2451 ConvertedType = AdoptQualifiers(Context, ConvertedType, FromQualifiers);
2452 return true;
2453 }
2454 }
2455 // Beyond this point, both types need to be C pointers or block pointers.
2456 QualType ToPointeeType;
2457 if (const PointerType *ToCPtr = ToType->getAs<PointerType>())
2458 ToPointeeType = ToCPtr->getPointeeType();
2459 else if (const BlockPointerType *ToBlockPtr =
2460 ToType->getAs<BlockPointerType>()) {
2461 // Objective C++: We're able to convert from a pointer to any object
2462 // to a block pointer type.
2463 if (FromObjCPtr && FromObjCPtr->isObjCBuiltinType()) {
2464 ConvertedType = AdoptQualifiers(Context, ToType, FromQualifiers);
2465 return true;
2466 }
2467 ToPointeeType = ToBlockPtr->getPointeeType();
2468 }
2469 else if (FromType->getAs<BlockPointerType>() &&
2470 ToObjCPtr && ToObjCPtr->isObjCBuiltinType()) {
2471 // Objective C++: We're able to convert from a block pointer type to a
2472 // pointer to any object.
2473 ConvertedType = AdoptQualifiers(Context, ToType, FromQualifiers);
2474 return true;
2475 }
2476 else
2477 return false;
2478
2479 QualType FromPointeeType;
2480 if (const PointerType *FromCPtr = FromType->getAs<PointerType>())
2481 FromPointeeType = FromCPtr->getPointeeType();
2482 else if (const BlockPointerType *FromBlockPtr =
2483 FromType->getAs<BlockPointerType>())
2484 FromPointeeType = FromBlockPtr->getPointeeType();
2485 else
2486 return false;
2487
2488 // If we have pointers to pointers, recursively check whether this
2489 // is an Objective-C conversion.
2490 if (FromPointeeType->isPointerType() && ToPointeeType->isPointerType() &&
2491 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType,
2492 IncompatibleObjC)) {
2493 // We always complain about this conversion.
2494 IncompatibleObjC = true;
2495 ConvertedType = Context.getPointerType(ConvertedType);
2496 ConvertedType = AdoptQualifiers(Context, ConvertedType, FromQualifiers);
2497 return true;
2498 }
2499 // Allow conversion of pointee being objective-c pointer to another one;
2500 // as in I* to id.
2501 if (FromPointeeType->getAs<ObjCObjectPointerType>() &&
2502 ToPointeeType->getAs<ObjCObjectPointerType>() &&
2503 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType,
2504 IncompatibleObjC)) {
2505
2506 ConvertedType = Context.getPointerType(ConvertedType);
2507 ConvertedType = AdoptQualifiers(Context, ConvertedType, FromQualifiers);
2508 return true;
2509 }
2510
2511 // If we have pointers to functions or blocks, check whether the only
2512 // differences in the argument and result types are in Objective-C
2513 // pointer conversions. If so, we permit the conversion (but
2514 // complain about it).
2515 const FunctionProtoType *FromFunctionType
2516 = FromPointeeType->getAs<FunctionProtoType>();
2517 const FunctionProtoType *ToFunctionType
2518 = ToPointeeType->getAs<FunctionProtoType>();
2519 if (FromFunctionType && ToFunctionType) {
2520 // If the function types are exactly the same, this isn't an
2521 // Objective-C pointer conversion.
2522 if (Context.getCanonicalType(FromPointeeType)
2523 == Context.getCanonicalType(ToPointeeType))
2524 return false;
2525
2526 // Perform the quick checks that will tell us whether these
2527 // function types are obviously different.
2528 if (FromFunctionType->getNumParams() != ToFunctionType->getNumParams() ||
2529 FromFunctionType->isVariadic() != ToFunctionType->isVariadic() ||
2530 FromFunctionType->getMethodQuals() != ToFunctionType->getMethodQuals())
2531 return false;
2532
2533 bool HasObjCConversion = false;
2534 if (Context.getCanonicalType(FromFunctionType->getReturnType()) ==
2535 Context.getCanonicalType(ToFunctionType->getReturnType())) {
2536 // Okay, the types match exactly. Nothing to do.
2537 } else if (isObjCPointerConversion(FromFunctionType->getReturnType(),
2538 ToFunctionType->getReturnType(),
2539 ConvertedType, IncompatibleObjC)) {
2540 // Okay, we have an Objective-C pointer conversion.
2541 HasObjCConversion = true;
2542 } else {
2543 // Function types are too different. Abort.
2544 return false;
2545 }
2546
2547 // Check argument types.
2548 for (unsigned ArgIdx = 0, NumArgs = FromFunctionType->getNumParams();
2549 ArgIdx != NumArgs; ++ArgIdx) {
2550 QualType FromArgType = FromFunctionType->getParamType(ArgIdx);
2551 QualType ToArgType = ToFunctionType->getParamType(ArgIdx);
2552 if (Context.getCanonicalType(FromArgType)
2553 == Context.getCanonicalType(ToArgType)) {
2554 // Okay, the types match exactly. Nothing to do.
2555 } else if (isObjCPointerConversion(FromArgType, ToArgType,
2556 ConvertedType, IncompatibleObjC)) {
2557 // Okay, we have an Objective-C pointer conversion.
2558 HasObjCConversion = true;
2559 } else {
2560 // Argument types are too different. Abort.
2561 return false;
2562 }
2563 }
2564
2565 if (HasObjCConversion) {
2566 // We had an Objective-C conversion. Allow this pointer
2567 // conversion, but complain about it.
2568 ConvertedType = AdoptQualifiers(Context, ToType, FromQualifiers);
2569 IncompatibleObjC = true;
2570 return true;
2571 }
2572 }
2573
2574 return false;
2575}
2576
2577/// Determine whether this is an Objective-C writeback conversion,
2578/// used for parameter passing when performing automatic reference counting.
2579///
2580/// \param FromType The type we're converting form.
2581///
2582/// \param ToType The type we're converting to.
2583///
2584/// \param ConvertedType The type that will be produced after applying
2585/// this conversion.
2586bool Sema::isObjCWritebackConversion(QualType FromType, QualType ToType,
2587 QualType &ConvertedType) {
2588 if (!getLangOpts().ObjCAutoRefCount ||
2589 Context.hasSameUnqualifiedType(FromType, ToType))
2590 return false;
2591
2592 // Parameter must be a pointer to __autoreleasing (with no other qualifiers).
2593 QualType ToPointee;
2594 if (const PointerType *ToPointer = ToType->getAs<PointerType>())
2595 ToPointee = ToPointer->getPointeeType();
2596 else
2597 return false;
2598
2599 Qualifiers ToQuals = ToPointee.getQualifiers();
2600 if (!ToPointee->isObjCLifetimeType() ||
2601 ToQuals.getObjCLifetime() != Qualifiers::OCL_Autoreleasing ||
2602 !ToQuals.withoutObjCLifetime().empty())
2603 return false;
2604
2605 // Argument must be a pointer to __strong to __weak.
2606 QualType FromPointee;
2607 if (const PointerType *FromPointer = FromType->getAs<PointerType>())
2608 FromPointee = FromPointer->getPointeeType();
2609 else
2610 return false;
2611
2612 Qualifiers FromQuals = FromPointee.getQualifiers();
2613 if (!FromPointee->isObjCLifetimeType() ||
2614 (FromQuals.getObjCLifetime() != Qualifiers::OCL_Strong &&
2615 FromQuals.getObjCLifetime() != Qualifiers::OCL_Weak))
2616 return false;
2617
2618 // Make sure that we have compatible qualifiers.
2619 FromQuals.setObjCLifetime(Qualifiers::OCL_Autoreleasing);
2620 if (!ToQuals.compatiblyIncludes(FromQuals))
2621 return false;
2622
2623 // Remove qualifiers from the pointee type we're converting from; they
2624 // aren't used in the compatibility check belong, and we'll be adding back
2625 // qualifiers (with __autoreleasing) if the compatibility check succeeds.
2626 FromPointee = FromPointee.getUnqualifiedType();
2627
2628 // The unqualified form of the pointee types must be compatible.
2629 ToPointee = ToPointee.getUnqualifiedType();
2630 bool IncompatibleObjC;
2631 if (Context.typesAreCompatible(FromPointee, ToPointee))
2632 FromPointee = ToPointee;
2633 else if (!isObjCPointerConversion(FromPointee, ToPointee, FromPointee,
2634 IncompatibleObjC))
2635 return false;
2636
2637 /// Construct the type we're converting to, which is a pointer to
2638 /// __autoreleasing pointee.
2639 FromPointee = Context.getQualifiedType(FromPointee, FromQuals);
2640 ConvertedType = Context.getPointerType(FromPointee);
2641 return true;
2642}
2643
2644bool Sema::IsBlockPointerConversion(QualType FromType, QualType ToType,
2645 QualType& ConvertedType) {
2646 QualType ToPointeeType;
2647 if (const BlockPointerType *ToBlockPtr =
2648 ToType->getAs<BlockPointerType>())
2649 ToPointeeType = ToBlockPtr->getPointeeType();
2650 else
2651 return false;
2652
2653 QualType FromPointeeType;
2654 if (const BlockPointerType *FromBlockPtr =
2655 FromType->getAs<BlockPointerType>())
2656 FromPointeeType = FromBlockPtr->getPointeeType();
2657 else
2658 return false;
2659 // We have pointer to blocks, check whether the only
2660 // differences in the argument and result types are in Objective-C
2661 // pointer conversions. If so, we permit the conversion.
2662
2663 const FunctionProtoType *FromFunctionType
2664 = FromPointeeType->getAs<FunctionProtoType>();
2665 const FunctionProtoType *ToFunctionType
2666 = ToPointeeType->getAs<FunctionProtoType>();
2667
2668 if (!FromFunctionType || !ToFunctionType)
2669 return false;
2670
2671 if (Context.hasSameType(FromPointeeType, ToPointeeType))
2672 return true;
2673
2674 // Perform the quick checks that will tell us whether these
2675 // function types are obviously different.
2676 if (FromFunctionType->getNumParams() != ToFunctionType->getNumParams() ||
2677 FromFunctionType->isVariadic() != ToFunctionType->isVariadic())
2678 return false;
2679
2680 FunctionType::ExtInfo FromEInfo = FromFunctionType->getExtInfo();
2681 FunctionType::ExtInfo ToEInfo = ToFunctionType->getExtInfo();
2682 if (FromEInfo != ToEInfo)
2683 return false;
2684
2685 bool IncompatibleObjC = false;
2686 if (Context.hasSameType(FromFunctionType->getReturnType(),
2687 ToFunctionType->getReturnType())) {
2688 // Okay, the types match exactly. Nothing to do.
2689 } else {
2690 QualType RHS = FromFunctionType->getReturnType();
2691 QualType LHS = ToFunctionType->getReturnType();
2692 if ((!getLangOpts().CPlusPlus || !RHS->isRecordType()) &&
2693 !RHS.hasQualifiers() && LHS.hasQualifiers())
2694 LHS = LHS.getUnqualifiedType();
2695
2696 if (Context.hasSameType(RHS,LHS)) {
2697 // OK exact match.
2698 } else if (isObjCPointerConversion(RHS, LHS,
2699 ConvertedType, IncompatibleObjC)) {
2700 if (IncompatibleObjC)
2701 return false;
2702 // Okay, we have an Objective-C pointer conversion.
2703 }
2704 else
2705 return false;
2706 }
2707
2708 // Check argument types.
2709 for (unsigned ArgIdx = 0, NumArgs = FromFunctionType->getNumParams();
2710 ArgIdx != NumArgs; ++ArgIdx) {
2711 IncompatibleObjC = false;
2712 QualType FromArgType = FromFunctionType->getParamType(ArgIdx);
2713 QualType ToArgType = ToFunctionType->getParamType(ArgIdx);
2714 if (Context.hasSameType(FromArgType, ToArgType)) {
2715 // Okay, the types match exactly. Nothing to do.
2716 } else if (isObjCPointerConversion(ToArgType, FromArgType,
2717 ConvertedType, IncompatibleObjC)) {
2718 if (IncompatibleObjC)
2719 return false;
2720 // Okay, we have an Objective-C pointer conversion.
2721 } else
2722 // Argument types are too different. Abort.
2723 return false;
2724 }
2725
2726 SmallVector<FunctionProtoType::ExtParameterInfo, 4> NewParamInfos;
2727 bool CanUseToFPT, CanUseFromFPT;
2728 if (!Context.mergeExtParameterInfo(ToFunctionType, FromFunctionType,
2729 CanUseToFPT, CanUseFromFPT,
2730 NewParamInfos))
2731 return false;
2732
2733 ConvertedType = ToType;
2734 return true;
2735}
2736
2737enum {
2738 ft_default,
2739 ft_different_class,
2740 ft_parameter_arity,
2741 ft_parameter_mismatch,
2742 ft_return_type,
2743 ft_qualifer_mismatch,
2744 ft_noexcept
2745};
2746
2747/// Attempts to get the FunctionProtoType from a Type. Handles
2748/// MemberFunctionPointers properly.
2749static const FunctionProtoType *tryGetFunctionProtoType(QualType FromType) {
2750 if (auto *FPT = FromType->getAs<FunctionProtoType>())
2751 return FPT;
2752
2753 if (auto *MPT = FromType->getAs<MemberPointerType>())
2754 return MPT->getPointeeType()->getAs<FunctionProtoType>();
2755
2756 return nullptr;
2757}
2758
2759/// HandleFunctionTypeMismatch - Gives diagnostic information for differeing
2760/// function types. Catches different number of parameter, mismatch in
2761/// parameter types, and different return types.
2762void Sema::HandleFunctionTypeMismatch(PartialDiagnostic &PDiag,
2763 QualType FromType, QualType ToType) {
2764 // If either type is not valid, include no extra info.
2765 if (FromType.isNull() || ToType.isNull()) {
2766 PDiag << ft_default;
2767 return;
2768 }
2769
2770 // Get the function type from the pointers.
2771 if (FromType->isMemberPointerType() && ToType->isMemberPointerType()) {
2772 const MemberPointerType *FromMember = FromType->getAs<MemberPointerType>(),
2773 *ToMember = ToType->getAs<MemberPointerType>();
2774 if (!Context.hasSameType(FromMember->getClass(), ToMember->getClass())) {
2775 PDiag << ft_different_class << QualType(ToMember->getClass(), 0)
2776 << QualType(FromMember->getClass(), 0);
2777 return;
2778 }
2779 FromType = FromMember->getPointeeType();
2780 ToType = ToMember->getPointeeType();
2781 }
2782
2783 if (FromType->isPointerType())
2784 FromType = FromType->getPointeeType();
2785 if (ToType->isPointerType())
2786 ToType = ToType->getPointeeType();
2787
2788 // Remove references.
2789 FromType = FromType.getNonReferenceType();
2790 ToType = ToType.getNonReferenceType();
2791
2792 // Don't print extra info for non-specialized template functions.
2793 if (FromType->isInstantiationDependentType() &&
2794 !FromType->getAs<TemplateSpecializationType>()) {
2795 PDiag << ft_default;
2796 return;
2797 }
2798
2799 // No extra info for same types.
2800 if (Context.hasSameType(FromType, ToType)) {
2801 PDiag << ft_default;
2802 return;
2803 }
2804
2805 const FunctionProtoType *FromFunction = tryGetFunctionProtoType(FromType),
2806 *ToFunction = tryGetFunctionProtoType(ToType);
2807
2808 // Both types need to be function types.
2809 if (!FromFunction || !ToFunction) {
2810 PDiag << ft_default;
2811 return;
2812 }
2813
2814 if (FromFunction->getNumParams() != ToFunction->getNumParams()) {
2815 PDiag << ft_parameter_arity << ToFunction->getNumParams()
2816 << FromFunction->getNumParams();
2817 return;
2818 }
2819
2820 // Handle different parameter types.
2821 unsigned ArgPos;
2822 if (!FunctionParamTypesAreEqual(FromFunction, ToFunction, &ArgPos)) {
2823 PDiag << ft_parameter_mismatch << ArgPos + 1
2824 << ToFunction->getParamType(ArgPos)
2825 << FromFunction->getParamType(ArgPos);
2826 return;
2827 }
2828
2829 // Handle different return type.
2830 if (!Context.hasSameType(FromFunction->getReturnType(),
2831 ToFunction->getReturnType())) {
2832 PDiag << ft_return_type << ToFunction->getReturnType()
2833 << FromFunction->getReturnType();
2834 return;
2835 }
2836
2837 if (FromFunction->getMethodQuals() != ToFunction->getMethodQuals()) {
2838 PDiag << ft_qualifer_mismatch << ToFunction->getMethodQuals()
2839 << FromFunction->getMethodQuals();
2840 return;
2841 }
2842
2843 // Handle exception specification differences on canonical type (in C++17
2844 // onwards).
2845 if (cast<FunctionProtoType>(FromFunction->getCanonicalTypeUnqualified())
2846 ->isNothrow() !=
2847 cast<FunctionProtoType>(ToFunction->getCanonicalTypeUnqualified())
2848 ->isNothrow()) {
2849 PDiag << ft_noexcept;
2850 return;
2851 }
2852
2853 // Unable to find a difference, so add no extra info.
2854 PDiag << ft_default;
2855}
2856
2857/// FunctionParamTypesAreEqual - This routine checks two function proto types
2858/// for equality of their argument types. Caller has already checked that
2859/// they have same number of arguments. If the parameters are different,
2860/// ArgPos will have the parameter index of the first different parameter.
2861bool Sema::FunctionParamTypesAreEqual(const FunctionProtoType *OldType,
2862 const FunctionProtoType *NewType,
2863 unsigned *ArgPos) {
2864 for (FunctionProtoType::param_type_iterator O = OldType->param_type_begin(),
2865 N = NewType->param_type_begin(),
2866 E = OldType->param_type_end();
2867 O && (O != E); ++O, ++N) {
2868 if (!Context.hasSameType(O->getUnqualifiedType(),
2869 N->getUnqualifiedType())) {
2870 if (ArgPos)
2871 *ArgPos = O - OldType->param_type_begin();
2872 return false;
2873 }
2874 }
2875 return true;
2876}
2877
2878/// CheckPointerConversion - Check the pointer conversion from the
2879/// expression From to the type ToType. This routine checks for
2880/// ambiguous or inaccessible derived-to-base pointer
2881/// conversions for which IsPointerConversion has already returned
2882/// true. It returns true and produces a diagnostic if there was an
2883/// error, or returns false otherwise.
2884bool Sema::CheckPointerConversion(Expr *From, QualType ToType,
2885 CastKind &Kind,
2886 CXXCastPath& BasePath,
2887 bool IgnoreBaseAccess,
2888 bool Diagnose) {
2889 QualType FromType = From->getType();
2890 bool IsCStyleOrFunctionalCast = IgnoreBaseAccess;
2891
2892 Kind = CK_BitCast;
2893
2894 if (Diagnose && !IsCStyleOrFunctionalCast && !FromType->isAnyPointerType() &&
2895 From->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNotNull) ==
2896 Expr::NPCK_ZeroExpression) {
2897 if (Context.hasSameUnqualifiedType(From->getType(), Context.BoolTy))
2898 DiagRuntimeBehavior(From->getExprLoc(), From,
2899 PDiag(diag::warn_impcast_bool_to_null_pointer)
2900 << ToType << From->getSourceRange());
2901 else if (!isUnevaluatedContext())
2902 Diag(From->getExprLoc(), diag::warn_non_literal_null_pointer)
2903 << ToType << From->getSourceRange();
2904 }
2905 if (const PointerType *ToPtrType = ToType->getAs<PointerType>()) {
2906 if (const PointerType *FromPtrType = FromType->getAs<PointerType>()) {
2907 QualType FromPointeeType = FromPtrType->getPointeeType(),
2908 ToPointeeType = ToPtrType->getPointeeType();
2909
2910 if (FromPointeeType->isRecordType() && ToPointeeType->isRecordType() &&
2911 !Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType)) {
2912 // We must have a derived-to-base conversion. Check an
2913 // ambiguous or inaccessible conversion.
2914 unsigned InaccessibleID = 0;
2915 unsigned AmbigiousID = 0;
2916 if (Diagnose) {
2917 InaccessibleID = diag::err_upcast_to_inaccessible_base;
2918 AmbigiousID = diag::err_ambiguous_derived_to_base_conv;
2919 }
2920 if (CheckDerivedToBaseConversion(
2921 FromPointeeType, ToPointeeType, InaccessibleID, AmbigiousID,
2922 From->getExprLoc(), From->getSourceRange(), DeclarationName(),
2923 &BasePath, IgnoreBaseAccess))
2924 return true;
2925
2926 // The conversion was successful.
2927 Kind = CK_DerivedToBase;
2928 }
2929
2930 if (Diagnose && !IsCStyleOrFunctionalCast &&
2931 FromPointeeType->isFunctionType() && ToPointeeType->isVoidType()) {
2932 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-9~svn360825/tools/clang/lib/Sema/SemaOverload.cpp"
, 2933, __PRETTY_FUNCTION__))
2933 "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-9~svn360825/tools/clang/lib/Sema/SemaOverload.cpp"
, 2933, __PRETTY_FUNCTION__))
;
2934 Diag(From->getExprLoc(), diag::ext_ms_impcast_fn_obj)
2935 << From->getSourceRange();
2936 }
2937 }
2938 } else if (const ObjCObjectPointerType *ToPtrType =
2939 ToType->getAs<ObjCObjectPointerType>()) {
2940 if (const ObjCObjectPointerType *FromPtrType =
2941 FromType->getAs<ObjCObjectPointerType>()) {
2942 // Objective-C++ conversions are always okay.
2943 // FIXME: We should have a different class of conversions for the
2944 // Objective-C++ implicit conversions.
2945 if (FromPtrType->isObjCBuiltinType() || ToPtrType->isObjCBuiltinType())
2946 return false;
2947 } else if (FromType->isBlockPointerType()) {
2948 Kind = CK_BlockPointerToObjCPointerCast;
2949 } else {
2950 Kind = CK_CPointerToObjCPointerCast;
2951 }
2952 } else if (ToType->isBlockPointerType()) {
2953 if (!FromType->isBlockPointerType())
2954 Kind = CK_AnyPointerToBlockPointerCast;
2955 }
2956
2957 // We shouldn't fall into this case unless it's valid for other
2958 // reasons.
2959 if (From->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull))
2960 Kind = CK_NullToPointer;
2961
2962 return false;
2963}
2964
2965/// IsMemberPointerConversion - Determines whether the conversion of the
2966/// expression From, which has the (possibly adjusted) type FromType, can be
2967/// converted to the type ToType via a member pointer conversion (C++ 4.11).
2968/// If so, returns true and places the converted type (that might differ from
2969/// ToType in its cv-qualifiers at some level) into ConvertedType.
2970bool Sema::IsMemberPointerConversion(Expr *From, QualType FromType,
2971 QualType ToType,
2972 bool InOverloadResolution,
2973 QualType &ConvertedType) {
2974 const MemberPointerType *ToTypePtr = ToType->getAs<MemberPointerType>();
2975 if (!ToTypePtr)
2976 return false;
2977
2978 // A null pointer constant can be converted to a member pointer (C++ 4.11p1)
2979 if (From->isNullPointerConstant(Context,
2980 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull
2981 : Expr::NPC_ValueDependentIsNull)) {
2982 ConvertedType = ToType;
2983 return true;
2984 }
2985
2986 // Otherwise, both types have to be member pointers.
2987 const MemberPointerType *FromTypePtr = FromType->getAs<MemberPointerType>();
2988 if (!FromTypePtr)
2989 return false;
2990
2991 // A pointer to member of B can be converted to a pointer to member of D,
2992 // where D is derived from B (C++ 4.11p2).
2993 QualType FromClass(FromTypePtr->getClass(), 0);
2994 QualType ToClass(ToTypePtr->getClass(), 0);
2995
2996 if (!Context.hasSameUnqualifiedType(FromClass, ToClass) &&
2997 IsDerivedFrom(From->getBeginLoc(), ToClass, FromClass)) {
2998 ConvertedType = Context.getMemberPointerType(FromTypePtr->getPointeeType(),
2999 ToClass.getTypePtr());
3000 return true;
3001 }
3002
3003 return false;
3004}
3005
3006/// CheckMemberPointerConversion - Check the member pointer conversion from the
3007/// expression From to the type ToType. This routine checks for ambiguous or
3008/// virtual or inaccessible base-to-derived member pointer conversions
3009/// for which IsMemberPointerConversion has already returned true. It returns
3010/// true and produces a diagnostic if there was an error, or returns false
3011/// otherwise.
3012bool Sema::CheckMemberPointerConversion(Expr *From, QualType ToType,
3013 CastKind &Kind,
3014 CXXCastPath &BasePath,
3015 bool IgnoreBaseAccess) {
3016 QualType FromType = From->getType();
3017 const MemberPointerType *FromPtrType = FromType->getAs<MemberPointerType>();
3018 if (!FromPtrType) {
3019 // This must be a null pointer to member pointer conversion
3020 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-9~svn360825/tools/clang/lib/Sema/SemaOverload.cpp"
, 3022, __PRETTY_FUNCTION__))
3021 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-9~svn360825/tools/clang/lib/Sema/SemaOverload.cpp"
, 3022, __PRETTY_FUNCTION__))
3022 "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-9~svn360825/tools/clang/lib/Sema/SemaOverload.cpp"
, 3022, __PRETTY_FUNCTION__))
;
3023 Kind = CK_NullToMemberPointer;
3024 return false;
3025 }
3026
3027 const MemberPointerType *ToPtrType = ToType->getAs<MemberPointerType>();
3028 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-9~svn360825/tools/clang/lib/Sema/SemaOverload.cpp"
, 3029, __PRETTY_FUNCTION__))
3029 "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-9~svn360825/tools/clang/lib/Sema/SemaOverload.cpp"
, 3029, __PRETTY_FUNCTION__))
;
3030
3031 QualType FromClass = QualType(FromPtrType->getClass(), 0);
3032 QualType ToClass = QualType(ToPtrType->getClass(), 0);
3033
3034 // FIXME: What about dependent types?
3035 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-9~svn360825/tools/clang/lib/Sema/SemaOverload.cpp"
, 3035, __PRETTY_FUNCTION__))
;
3036 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-9~svn360825/tools/clang/lib/Sema/SemaOverload.cpp"
, 3036, __PRETTY_FUNCTION__))
;
3037
3038 CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
3039 /*DetectVirtual=*/true);
3040 bool DerivationOkay =
3041 IsDerivedFrom(From->getBeginLoc(), ToClass, FromClass, Paths);
3042 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-9~svn360825/tools/clang/lib/Sema/SemaOverload.cpp"
, 3043, __PRETTY_FUNCTION__))
3043 "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-9~svn360825/tools/clang/lib/Sema/SemaOverload.cpp"
, 3043, __PRETTY_FUNCTION__))
;
3044 (void)DerivationOkay;
3045
3046 if (Paths.isAmbiguous(Context.getCanonicalType(FromClass).
3047 getUnqualifiedType())) {
3048 std::string PathDisplayStr = getAmbiguousPathsDisplayString(Paths);
3049 Diag(From->getExprLoc(), diag::err_ambiguous_memptr_conv)
3050 << 0 << FromClass << ToClass << PathDisplayStr << From->getSourceRange();
3051 return true;
3052 }
3053
3054 if (const RecordType *VBase = Paths.getDetectedVirtual()) {
3055 Diag(From->getExprLoc(), diag::err_memptr_conv_via_virtual)
3056 << FromClass << ToClass << QualType(VBase, 0)
3057 << From->getSourceRange();
3058 return true;
3059 }
3060
3061 if (!IgnoreBaseAccess)
3062 CheckBaseClassAccess(From->getExprLoc(), FromClass, ToClass,
3063 Paths.front(),
3064 diag::err_downcast_from_inaccessible_base);
3065
3066 // Must be a base to derived member conversion.
3067 BuildBasePathArray(Paths, BasePath);
3068 Kind = CK_BaseToDerivedMemberPointer;
3069 return false;
3070}
3071
3072/// Determine whether the lifetime conversion between the two given
3073/// qualifiers sets is nontrivial.
3074static bool isNonTrivialObjCLifetimeConversion(Qualifiers FromQuals,
3075 Qualifiers ToQuals) {
3076 // Converting anything to const __unsafe_unretained is trivial.
3077 if (ToQuals.hasConst() &&
3078 ToQuals.getObjCLifetime() == Qualifiers::OCL_ExplicitNone)
3079 return false;
3080
3081 return true;
3082}
3083
3084/// IsQualificationConversion - Determines whether the conversion from
3085/// an rvalue of type FromType to ToType is a qualification conversion
3086/// (C++ 4.4).
3087///
3088/// \param ObjCLifetimeConversion Output parameter that will be set to indicate
3089/// when the qualification conversion involves a change in the Objective-C
3090/// object lifetime.
3091bool
3092Sema::IsQualificationConversion(QualType FromType, QualType ToType,
3093 bool CStyle, bool &ObjCLifetimeConversion) {
3094 FromType = Context.getCanonicalType(FromType);
3095 ToType = Context.getCanonicalType(ToType);
3096 ObjCLifetimeConversion = false;
3097
3098 // If FromType and ToType are the same type, this is not a
3099 // qualification conversion.
3100 if (FromType.getUnqualifiedType() == ToType.getUnqualifiedType())
3101 return false;
3102
3103 // (C++ 4.4p4):
3104 // A conversion can add cv-qualifiers at levels other than the first
3105 // in multi-level pointers, subject to the following rules: [...]
3106 bool PreviousToQualsIncludeConst = true;
3107 bool UnwrappedAnyPointer = false;
3108 while (Context.UnwrapSimilarTypes(FromType, ToType)) {
3109 // Within each iteration of the loop, we check the qualifiers to
3110 // determine if this still looks like a qualification
3111 // conversion. Then, if all is well, we unwrap one more level of
3112 // pointers or pointers-to-members and do it all again
3113 // until there are no more pointers or pointers-to-members left to
3114 // unwrap.
3115 UnwrappedAnyPointer = true;
3116
3117 Qualifiers FromQuals = FromType.getQualifiers();
3118 Qualifiers ToQuals = ToType.getQualifiers();
3119
3120 // Ignore __unaligned qualifier if this type is void.
3121 if (ToType.getUnqualifiedType()->isVoidType())
3122 FromQuals.removeUnaligned();
3123
3124 // Objective-C ARC:
3125 // Check Objective-C lifetime conversions.
3126 if (FromQuals.getObjCLifetime() != ToQuals.getObjCLifetime() &&
3127 UnwrappedAnyPointer) {
3128 if (ToQuals.compatiblyIncludesObjCLifetime(FromQuals)) {
3129 if (isNonTrivialObjCLifetimeConversion(FromQuals, ToQuals))
3130 ObjCLifetimeConversion = true;
3131 FromQuals.removeObjCLifetime();
3132 ToQuals.removeObjCLifetime();
3133 } else {
3134 // Qualification conversions cannot cast between different
3135 // Objective-C lifetime qualifiers.
3136 return false;
3137 }
3138 }
3139
3140 // Allow addition/removal of GC attributes but not changing GC attributes.
3141 if (FromQuals.getObjCGCAttr() != ToQuals.getObjCGCAttr() &&
3142 (!FromQuals.hasObjCGCAttr() || !ToQuals.hasObjCGCAttr())) {
3143 FromQuals.removeObjCGCAttr();
3144 ToQuals.removeObjCGCAttr();
3145 }
3146
3147 // -- for every j > 0, if const is in cv 1,j then const is in cv
3148 // 2,j, and similarly for volatile.
3149 if (!CStyle && !ToQuals.compatiblyIncludes(FromQuals))
3150 return false;
3151
3152 // -- if the cv 1,j and cv 2,j are different, then const is in
3153 // every cv for 0 < k < j.
3154 if (!CStyle && FromQuals.getCVRQualifiers() != ToQuals.getCVRQualifiers()
3155 && !PreviousToQualsIncludeConst)
3156 return false;
3157
3158 // Keep track of whether all prior cv-qualifiers in the "to" type
3159 // include const.
3160 PreviousToQualsIncludeConst
3161 = PreviousToQualsIncludeConst && ToQuals.hasConst();
3162 }
3163
3164 // Allows address space promotion by language rules implemented in
3165 // Type::Qualifiers::isAddressSpaceSupersetOf.
3166 Qualifiers FromQuals = FromType.getQualifiers();
3167 Qualifiers ToQuals = ToType.getQualifiers();
3168 if (!ToQuals.isAddressSpaceSupersetOf(FromQuals) &&
3169 !FromQuals.isAddressSpaceSupersetOf(ToQuals)) {
3170 return false;
3171 }
3172
3173 // We are left with FromType and ToType being the pointee types
3174 // after unwrapping the original FromType and ToType the same number
3175 // of types. If we unwrapped any pointers, and if FromType and
3176 // ToType have the same unqualified type (since we checked
3177 // qualifiers above), then this is a qualification conversion.
3178 return UnwrappedAnyPointer && Context.hasSameUnqualifiedType(FromType,ToType);
3179}
3180
3181/// - Determine whether this is a conversion from a scalar type to an
3182/// atomic type.
3183///
3184/// If successful, updates \c SCS's second and third steps in the conversion
3185/// sequence to finish the conversion.
3186static bool tryAtomicConversion(Sema &S, Expr *From, QualType ToType,
3187 bool InOverloadResolution,
3188 StandardConversionSequence &SCS,
3189 bool CStyle) {
3190 const AtomicType *ToAtomic = ToType->getAs<AtomicType>();
3191 if (!ToAtomic)
3192 return false;
3193
3194 StandardConversionSequence InnerSCS;
3195 if (!IsStandardConversion(S, From, ToAtomic->getValueType(),
3196 InOverloadResolution, InnerSCS,
3197 CStyle, /*AllowObjCWritebackConversion=*/false))
3198 return false;
3199
3200 SCS.Second = InnerSCS.Second;
3201 SCS.setToType(1, InnerSCS.getToType(1));
3202 SCS.Third = InnerSCS.Third;
3203 SCS.QualificationIncludesObjCLifetime
3204 = InnerSCS.QualificationIncludesObjCLifetime;
3205 SCS.setToType(2, InnerSCS.getToType(2));
3206 return true;
3207}
3208
3209static bool isFirstArgumentCompatibleWithType(ASTContext &Context,
3210 CXXConstructorDecl *Constructor,
3211 QualType Type) {
3212 const FunctionProtoType *CtorType =
3213 Constructor->getType()->getAs<FunctionProtoType>();
3214 if (CtorType->getNumParams() > 0) {
3215 QualType FirstArg = CtorType->getParamType(0);
3216 if (Context.hasSameUnqualifiedType(Type, FirstArg.getNonReferenceType()))
3217 return true;
3218 }
3219 return false;
3220}
3221
3222static OverloadingResult
3223IsInitializerListConstructorConversion(Sema &S, Expr *From, QualType ToType,
3224 CXXRecordDecl *To,
3225 UserDefinedConversionSequence &User,
3226 OverloadCandidateSet &CandidateSet,
3227 bool AllowExplicit) {
3228 CandidateSet.clear(OverloadCandidateSet::CSK_InitByUserDefinedConversion);
3229 for (auto *D : S.LookupConstructors(To)) {
3230 auto Info = getConstructorInfo(D);
3231 if (!Info)
3232 continue;
3233
3234 bool Usable = !Info.Constructor->isInvalidDecl() &&
3235 S.isInitListConstructor(Info.Constructor) &&
3236 (AllowExplicit || !Info.Constructor->isExplicit());
3237 if (Usable) {
3238 // If the first argument is (a reference to) the target type,
3239 // suppress conversions.
3240 bool SuppressUserConversions = isFirstArgumentCompatibleWithType(
3241 S.Context, Info.Constructor, ToType);
3242 if (Info.ConstructorTmpl)
3243 S.AddTemplateOverloadCandidate(Info.ConstructorTmpl, Info.FoundDecl,
3244 /*ExplicitArgs*/ nullptr, From,
3245 CandidateSet, SuppressUserConversions,
3246 /*PartialOverloading*/ false,
3247 AllowExplicit);
3248 else
3249 S.AddOverloadCandidate(Info.Constructor, Info.FoundDecl, From,
3250 CandidateSet, SuppressUserConversions,
3251 /*PartialOverloading*/ false, AllowExplicit);
3252 }
3253 }
3254
3255 bool HadMultipleCandidates = (CandidateSet.size() > 1);
3256
3257 OverloadCandidateSet::iterator Best;
3258 switch (auto Result =
3259 CandidateSet.BestViableFunction(S, From->getBeginLoc(), Best)) {
3260 case OR_Deleted:
3261 case OR_Success: {
3262 // Record the standard conversion we used and the conversion function.
3263 CXXConstructorDecl *Constructor = cast<CXXConstructorDecl>(Best->Function);
3264 QualType ThisType = Constructor->getThisType();
3265 // Initializer lists don't have conversions as such.
3266 User.Before.setAsIdentityConversion();
3267 User.HadMultipleCandidates = HadMultipleCandidates;
3268 User.ConversionFunction = Constructor;
3269 User.FoundConversionFunction = Best->FoundDecl;
3270 User.After.setAsIdentityConversion();
3271 User.After.setFromType(ThisType->getAs<PointerType>()->getPointeeType());
3272 User.After.setAllToTypes(ToType);
3273 return Result;
3274 }
3275
3276 case OR_No_Viable_Function:
3277 return OR_No_Viable_Function;
3278 case OR_Ambiguous:
3279 return OR_Ambiguous;
3280 }
3281
3282 llvm_unreachable("Invalid OverloadResult!")::llvm::llvm_unreachable_internal("Invalid OverloadResult!", "/build/llvm-toolchain-snapshot-9~svn360825/tools/clang/lib/Sema/SemaOverload.cpp"
, 3282)
;
3283}
3284
3285/// Determines whether there is a user-defined conversion sequence
3286/// (C++ [over.ics.user]) that converts expression From to the type
3287/// ToType. If such a conversion exists, User will contain the
3288/// user-defined conversion sequence that performs such a conversion
3289/// and this routine will return true. Otherwise, this routine returns
3290/// false and User is unspecified.
3291///
3292/// \param AllowExplicit true if the conversion should consider C++0x
3293/// "explicit" conversion functions as well as non-explicit conversion
3294/// functions (C++0x [class.conv.fct]p2).
3295///
3296/// \param AllowObjCConversionOnExplicit true if the conversion should
3297/// allow an extra Objective-C pointer conversion on uses of explicit
3298/// constructors. Requires \c AllowExplicit to also be set.
3299static OverloadingResult
3300IsUserDefinedConversion(Sema &S, Expr *From, QualType ToType,
3301 UserDefinedConversionSequence &User,
3302 OverloadCandidateSet &CandidateSet,
3303 bool AllowExplicit,
3304 bool AllowObjCConversionOnExplicit) {
3305 assert(AllowExplicit || !AllowObjCConversionOnExplicit)((AllowExplicit || !AllowObjCConversionOnExplicit) ? static_cast
<void> (0) : __assert_fail ("AllowExplicit || !AllowObjCConversionOnExplicit"
, "/build/llvm-toolchain-snapshot-9~svn360825/tools/clang/lib/Sema/SemaOverload.cpp"
, 3305, __PRETTY_FUNCTION__))
;
3306 CandidateSet.clear(OverloadCandidateSet::CSK_InitByUserDefinedConversion);
3307
3308 // Whether we will only visit constructors.
3309 bool ConstructorsOnly = false;
3310
3311 // If the type we are conversion to is a class type, enumerate its
3312 // constructors.
3313 if (const RecordType *ToRecordType = ToType->getAs<RecordType>()) {
3314 // C++ [over.match.ctor]p1:
3315 // When objects of class type are direct-initialized (8.5), or
3316 // copy-initialized from an expression of the same or a
3317 // derived class type (8.5), overload resolution selects the
3318 // constructor. [...] For copy-initialization, the candidate
3319 // functions are all the converting constructors (12.3.1) of
3320 // that class. The argument list is the expression-list within
3321 // the parentheses of the initializer.
3322 if (S.Context.hasSameUnqualifiedType(ToType, From->getType()) ||
3323 (From->getType()->getAs<RecordType>() &&
3324 S.IsDerivedFrom(From->getBeginLoc(), From->getType(), ToType)))
3325 ConstructorsOnly = true;
3326
3327 if (!S.isCompleteType(From->getExprLoc(), ToType)) {
3328 // We're not going to find any constructors.
3329 } else if (CXXRecordDecl *ToRecordDecl
3330 = dyn_cast<CXXRecordDecl>(ToRecordType->getDecl())) {
3331
3332 Expr **Args = &From;
3333 unsigned NumArgs = 1;
3334 bool ListInitializing = false;
3335 if (InitListExpr *InitList = dyn_cast<InitListExpr>(From)) {
3336 // But first, see if there is an init-list-constructor that will work.
3337 OverloadingResult Result = IsInitializerListConstructorConversion(
3338 S, From, ToType, ToRecordDecl, User, CandidateSet, AllowExplicit);
3339 if (Result != OR_No_Viable_Function)
3340 return Result;
3341 // Never mind.
3342 CandidateSet.clear(
3343 OverloadCandidateSet::CSK_InitByUserDefinedConversion);
3344
3345 // If we're list-initializing, we pass the individual elements as
3346 // arguments, not the entire list.
3347 Args = InitList->getInits();
3348 NumArgs = InitList->getNumInits();
3349 ListInitializing = true;
3350 }
3351
3352 for (auto *D : S.LookupConstructors(ToRecordDecl)) {
3353 auto Info = getConstructorInfo(D);
3354 if (!Info)
3355 continue;
3356
3357 bool Usable = !Info.Constructor->isInvalidDecl();
3358 if (ListInitializing)
3359 Usable = Usable && (AllowExplicit || !Info.Constructor->isExplicit());
3360 else
3361 Usable = Usable &&
3362 Info.Constructor->isConvertingConstructor(AllowExplicit);
3363 if (Usable) {
3364 bool SuppressUserConversions = !ConstructorsOnly;
3365 if (SuppressUserConversions && ListInitializing) {
3366 SuppressUserConversions = false;
3367 if (NumArgs == 1) {
3368 // If the first argument is (a reference to) the target type,
3369 // suppress conversions.
3370 SuppressUserConversions = isFirstArgumentCompatibleWithType(
3371 S.Context, Info.Constructor, ToType);
3372 }
3373 }
3374 if (Info.ConstructorTmpl)
3375 S.AddTemplateOverloadCandidate(
3376 Info.ConstructorTmpl, Info.FoundDecl,
3377 /*ExplicitArgs*/ nullptr, llvm::makeArrayRef(Args, NumArgs),
3378 CandidateSet, SuppressUserConversions,
3379 /*PartialOverloading*/ false, AllowExplicit);
3380 else
3381 // Allow one user-defined conversion when user specifies a
3382 // From->ToType conversion via an static cast (c-style, etc).
3383 S.AddOverloadCandidate(Info.Constructor, Info.FoundDecl,
3384 llvm::makeArrayRef(Args, NumArgs),
3385 CandidateSet, SuppressUserConversions,
3386 /*PartialOverloading*/ false, AllowExplicit);
3387 }
3388 }
3389 }
3390 }
3391
3392 // Enumerate conversion functions, if we're allowed to.
3393 if (ConstructorsOnly || isa<InitListExpr>(From)) {
3394 } else if (!S.isCompleteType(From->getBeginLoc(), From->getType())) {
3395 // No conversion functions from incomplete types.
3396 } else if (const RecordType *FromRecordType =
3397 From->getType()->getAs<RecordType>()) {
3398 if (CXXRecordDecl *FromRecordDecl
3399 = dyn_cast<CXXRecordDecl>(FromRecordType->getDecl())) {
3400 // Add all of the conversion functions as candidates.
3401 const auto &Conversions = FromRecordDecl->getVisibleConversionFunctions();
3402 for (auto I = Conversions.begin(), E = Conversions.end(); I != E; ++I) {
3403 DeclAccessPair FoundDecl = I.getPair();
3404 NamedDecl *D = FoundDecl.getDecl();
3405 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext());
3406 if (isa<UsingShadowDecl>(D))
3407 D = cast<UsingShadowDecl>(D)->getTargetDecl();
3408
3409 CXXConversionDecl *Conv;
3410 FunctionTemplateDecl *ConvTemplate;
3411 if ((ConvTemplate = dyn_cast<FunctionTemplateDecl>(D)))
3412 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl());
3413 else
3414 Conv = cast<CXXConversionDecl>(D);
3415
3416 if (AllowExplicit || !Conv->isExplicit()) {
3417 if (ConvTemplate)
3418 S.AddTemplateConversionCandidate(
3419 ConvTemplate, FoundDecl, ActingContext, From, ToType,
3420 CandidateSet, AllowObjCConversionOnExplicit, AllowExplicit);
3421 else
3422 S.AddConversionCandidate(
3423 Conv, FoundDecl, ActingContext, From, ToType, CandidateSet,
3424 AllowObjCConversionOnExplicit, AllowExplicit);
3425 }
3426 }
3427 }
3428 }
3429
3430 bool HadMultipleCandidates = (CandidateSet.size() > 1);
3431
3432 OverloadCandidateSet::iterator Best;
3433 switch (auto Result =
3434 CandidateSet.BestViableFunction(S, From->getBeginLoc(), Best)) {
3435 case OR_Success:
3436 case OR_Deleted:
3437 // Record the standard conversion we used and the conversion function.
3438 if (CXXConstructorDecl *Constructor
3439 = dyn_cast<CXXConstructorDecl>(Best->Function)) {
3440 // C++ [over.ics.user]p1:
3441 // If the user-defined conversion is specified by a
3442 // constructor (12.3.1), the initial standard conversion
3443 // sequence converts the source type to the type required by
3444 // the argument of the constructor.
3445 //
3446 QualType ThisType = Constructor->getThisType();
3447 if (isa<InitListExpr>(From)) {
3448 // Initializer lists don't have conversions as such.
3449 User.Before.setAsIdentityConversion();
3450 } else {
3451 if (Best->Conversions[0].isEllipsis())
3452 User.EllipsisConversion = true;
3453 else {
3454 User.Before = Best->Conversions[0].Standard;
3455 User.EllipsisConversion = false;
3456 }
3457 }
3458 User.HadMultipleCandidates = HadMultipleCandidates;
3459 User.ConversionFunction = Constructor;
3460 User.FoundConversionFunction = Best->FoundDecl;
3461 User.After.setAsIdentityConversion();
3462 User.After.setFromType(ThisType->getAs<PointerType>()->getPointeeType());
3463 User.After.setAllToTypes(ToType);
3464 return Result;
3465 }
3466 if (CXXConversionDecl *Conversion
3467 = dyn_cast<CXXConversionDecl>(Best->Function)) {
3468 // C++ [over.ics.user]p1:
3469 //
3470 // [...] If the user-defined conversion is specified by a
3471 // conversion function (12.3.2), the initial standard
3472 // conversion sequence converts the source type to the
3473 // implicit object parameter of the conversion function.
3474 User.Before = Best->Conversions[0].Standard;
3475 User.HadMultipleCandidates = HadMultipleCandidates;
3476 User.ConversionFunction = Conversion;
3477 User.FoundConversionFunction = Best->FoundDecl;
3478 User.EllipsisConversion = false;
3479
3480 // C++ [over.ics.user]p2:
3481 // The second standard conversion sequence converts the
3482 // result of the user-defined conversion to the target type
3483 // for the sequence. Since an implicit conversion sequence
3484 // is an initialization, the special rules for
3485 // initialization by user-defined conversion apply when
3486 // selecting the best user-defined conversion for a
3487 // user-defined conversion sequence (see 13.3.3 and
3488 // 13.3.3.1).
3489 User.After = Best->FinalConversion;
3490 return Result;
3491 }
3492 llvm_unreachable("Not a constructor or conversion function?")::llvm::llvm_unreachable_internal("Not a constructor or conversion function?"
, "/build/llvm-toolchain-snapshot-9~svn360825/tools/clang/lib/Sema/SemaOverload.cpp"
, 3492)
;
3493
3494 case OR_No_Viable_Function:
3495 return OR_No_Viable_Function;
3496
3497 case OR_Ambiguous:
3498 return OR_Ambiguous;
3499 }
3500
3501 llvm_unreachable("Invalid OverloadResult!")::llvm::llvm_unreachable_internal("Invalid OverloadResult!", "/build/llvm-toolchain-snapshot-9~svn360825/tools/clang/lib/Sema/SemaOverload.cpp"
, 3501)
;
3502}
3503
3504bool
3505Sema::DiagnoseMultipleUserDefinedConversion(Expr *From, QualType ToType) {
3506 ImplicitConversionSequence ICS;
3507 OverloadCandidateSet CandidateSet(From->getExprLoc(),
3508 OverloadCandidateSet::CSK_Normal);
3509 OverloadingResult OvResult =
3510 IsUserDefinedConversion(*this, From, ToType, ICS.UserDefined,
3511 CandidateSet, false, false);
3512
3513 if (!(OvResult == OR_Ambiguous ||
3514 (OvResult == OR_No_Viable_Function && !CandidateSet.empty())))
3515 return false;
3516
3517 auto Cands = CandidateSet.CompleteCandidates(*this, OCD_AllCandidates, From);
3518 if (OvResult == OR_Ambiguous)
3519 Diag(From->getBeginLoc(), diag::err_typecheck_ambiguous_condition)
3520 << From->getType() << ToType << From->getSourceRange();
3521 else { // OR_No_Viable_Function && !CandidateSet.empty()
3522 if (!RequireCompleteType(From->getBeginLoc(), ToType,
3523 diag::err_typecheck_nonviable_condition_incomplete,
3524 From->getType(), From->getSourceRange()))
3525 Diag(From->getBeginLoc(), diag::err_typecheck_nonviable_condition)
3526 << false << From->getType() << From->getSourceRange() << ToType;
3527 }
3528
3529 CandidateSet.NoteCandidates(
3530 *this, From, Cands);
3531 return true;
3532}
3533
3534/// Compare the user-defined conversion functions or constructors
3535/// of two user-defined conversion sequences to determine whether any ordering
3536/// is possible.
3537static ImplicitConversionSequence::CompareKind
3538compareConversionFunctions(Sema &S, FunctionDecl *Function1,
3539 FunctionDecl *Function2) {
3540 if (!S.getLangOpts().ObjC || !S.getLangOpts().CPlusPlus11)
3541 return ImplicitConversionSequence::Indistinguishable;
3542
3543 // Objective-C++:
3544 // If both conversion functions are implicitly-declared conversions from
3545 // a lambda closure type to a function pointer and a block pointer,
3546 // respectively, always prefer the conversion to a function pointer,
3547 // because the function pointer is more lightweight and is more likely
3548 // to keep code working.
3549 CXXConversionDecl *Conv1 = dyn_cast_or_null<CXXConversionDecl>(Function1);
3550 if (!Conv1)
3551 return ImplicitConversionSequence::Indistinguishable;
3552
3553 CXXConversionDecl *Conv2 = dyn_cast<CXXConversionDecl>(Function2);
3554 if (!Conv2)
3555 return ImplicitConversionSequence::Indistinguishable;
3556
3557 if (Conv1->getParent()->isLambda() && Conv2->getParent()->isLambda()) {
3558 bool Block1 = Conv1->getConversionType()->isBlockPointerType();
3559 bool Block2 = Conv2->getConversionType()->isBlockPointerType();
3560 if (Block1 != Block2)
3561 return Block1 ? ImplicitConversionSequence::Worse
3562 : ImplicitConversionSequence::Better;
3563 }
3564
3565 return ImplicitConversionSequence::Indistinguishable;
3566}
3567
3568static bool hasDeprecatedStringLiteralToCharPtrConversion(
3569 const ImplicitConversionSequence &ICS) {
3570 return (ICS.isStandard() && ICS.Standard.DeprecatedStringLiteralToCharPtr) ||
3571 (ICS.isUserDefined() &&
3572 ICS.UserDefined.Before.DeprecatedStringLiteralToCharPtr);
3573}
3574
3575/// CompareImplicitConversionSequences - Compare two implicit
3576/// conversion sequences to determine whether one is better than the
3577/// other or if they are indistinguishable (C++ 13.3.3.2).
3578static ImplicitConversionSequence::CompareKind
3579CompareImplicitConversionSequences(Sema &S, SourceLocation Loc,
3580 const ImplicitConversionSequence& ICS1,
3581 const ImplicitConversionSequence& ICS2)
3582{
3583 // (C++ 13.3.3.2p2): When comparing the basic forms of implicit
3584 // conversion sequences (as defined in 13.3.3.1)
3585 // -- a standard conversion sequence (13.3.3.1.1) is a better
3586 // conversion sequence than a user-defined conversion sequence or
3587 // an ellipsis conversion sequence, and
3588 // -- a user-defined conversion sequence (13.3.3.1.2) is a better
3589 // conversion sequence than an ellipsis conversion sequence
3590 // (13.3.3.1.3).
3591 //
3592 // C++0x [over.best.ics]p10:
3593 // For the purpose of ranking implicit conversion sequences as
3594 // described in 13.3.3.2, the ambiguous conversion sequence is
3595 // treated as a user-defined sequence that is indistinguishable
3596 // from any other user-defined conversion sequence.
3597
3598 // String literal to 'char *' conversion has been deprecated in C++03. It has
3599 // been removed from C++11. We still accept this conversion, if it happens at
3600 // the best viable function. Otherwise, this conversion is considered worse
3601 // than ellipsis conversion. Consider this as an extension; this is not in the
3602 // standard. For example:
3603 //
3604 // int &f(...); // #1
3605 // void f(char*); // #2
3606 // void g() { int &r = f("foo"); }
3607 //
3608 // In C++03, we pick #2 as the best viable function.
3609 // In C++11, we pick #1 as the best viable function, because ellipsis
3610 // conversion is better than string-literal to char* conversion (since there
3611 // is no such conversion in C++11). If there was no #1 at all or #1 couldn't
3612 // convert arguments, #2 would be the best viable function in C++11.
3613 // If the best viable function has this conversion, a warning will be issued
3614 // in C++03, or an ExtWarn (+SFINAE failure) will be issued in C++11.
3615
3616 if (S.getLangOpts().CPlusPlus11 && !S.getLangOpts().WritableStrings &&
3617 hasDeprecatedStringLiteralToCharPtrConversion(ICS1) !=
3618 hasDeprecatedStringLiteralToCharPtrConversion(ICS2))
3619 return hasDeprecatedStringLiteralToCharPtrConversion(ICS1)
3620 ? ImplicitConversionSequence::Worse
3621 : ImplicitConversionSequence::Better;
3622
3623 if (ICS1.getKindRank() < ICS2.getKindRank())
3624 return ImplicitConversionSequence::Better;
3625 if (ICS2.getKindRank() < ICS1.getKindRank())
3626 return ImplicitConversionSequence::Worse;
3627
3628 // The following checks require both conversion sequences to be of
3629 // the same kind.
3630 if (ICS1.getKind() != ICS2.getKind())
3631 return ImplicitConversionSequence::Indistinguishable;
3632
3633 ImplicitConversionSequence::CompareKind Result =
3634 ImplicitConversionSequence::Indistinguishable;
3635
3636 // Two implicit conversion sequences of the same form are
3637 // indistinguishable conversion sequences unless one of the
3638 // following rules apply: (C++ 13.3.3.2p3):
3639
3640 // List-initialization sequence L1 is a better conversion sequence than
3641 // list-initialization sequence L2 if:
3642 // - L1 converts to std::initializer_list<X> for some X and L2 does not, or,
3643 // if not that,
3644 // - L1 converts to type "array of N1 T", L2 converts to type "array of N2 T",
3645 // and N1 is smaller than N2.,
3646 // even if one of the other rules in this paragraph would otherwise apply.
3647 if (!ICS1.isBad()) {
3648 if (ICS1.isStdInitializerListElement() &&
3649 !ICS2.isStdInitializerListElement())
3650 return ImplicitConversionSequence::Better;
3651 if (!ICS1.isStdInitializerListElement() &&
3652 ICS2.isStdInitializerListElement())
3653 return ImplicitConversionSequence::Worse;
3654 }
3655
3656 if (ICS1.isStandard())
3657 // Standard conversion sequence S1 is a better conversion sequence than
3658 // standard conversion sequence S2 if [...]
3659 Result = CompareStandardConversionSequences(S, Loc,
3660 ICS1.Standard, ICS2.Standard);
3661 else if (ICS1.isUserDefined()) {
3662 // User-defined conversion sequence U1 is a better conversion
3663 // sequence than another user-defined conversion sequence U2 if
3664 // they contain the same user-defined conversion function or
3665 // constructor and if the second standard conversion sequence of
3666 // U1 is better than the second standard conversion sequence of
3667 // U2 (C++ 13.3.3.2p3).
3668 if (ICS1.UserDefined.ConversionFunction ==
3669 ICS2.UserDefined.ConversionFunction)
3670 Result = CompareStandardConversionSequences(S, Loc,
3671 ICS1.UserDefined.After,
3672 ICS2.UserDefined.After);
3673 else
3674 Result = compareConversionFunctions(S,
3675 ICS1.UserDefined.ConversionFunction,
3676 ICS2.UserDefined.ConversionFunction);
3677 }
3678
3679 return Result;
3680}
3681
3682// Per 13.3.3.2p3, compare the given standard conversion sequences to
3683// determine if one is a proper subset of the other.
3684static ImplicitConversionSequence::CompareKind
3685compareStandardConversionSubsets(ASTContext &Context,
3686 const StandardConversionSequence& SCS1,
3687 const StandardConversionSequence& SCS2) {
3688 ImplicitConversionSequence::CompareKind Result
3689 = ImplicitConversionSequence::Indistinguishable;
3690
3691 // the identity conversion sequence is considered to be a subsequence of
3692 // any non-identity conversion sequence
3693 if (SCS1.isIdentityConversion() && !SCS2.isIdentityConversion())
3694 return ImplicitConversionSequence::Better;
3695 else if (!SCS1.isIdentityConversion() && SCS2.isIdentityConversion())
3696 return ImplicitConversionSequence::Worse;
3697
3698 if (SCS1.Second != SCS2.Second) {
3699 if (SCS1.Second == ICK_Identity)
3700 Result = ImplicitConversionSequence::Better;
3701 else if (SCS2.Second == ICK_Identity)
3702 Result = ImplicitConversionSequence::Worse;
3703 else
3704 return ImplicitConversionSequence::Indistinguishable;
3705 } else if (!Context.hasSimilarType(SCS1.getToType(1), SCS2.getToType(1)))
3706 return ImplicitConversionSequence::Indistinguishable;
3707
3708 if (SCS1.Third == SCS2.Third) {
3709 return Context.hasSameType(SCS1.getToType(2), SCS2.getToType(2))? Result
3710 : ImplicitConversionSequence::Indistinguishable;
3711 }
3712
3713 if (SCS1.Third == ICK_Identity)
3714 return Result == ImplicitConversionSequence::Worse
3715 ? ImplicitConversionSequence::Indistinguishable
3716 : ImplicitConversionSequence::Better;
3717
3718 if (SCS2.Third == ICK_Identity)
3719 return Result == ImplicitConversionSequence::Better
3720 ? ImplicitConversionSequence::Indistinguishable
3721 : ImplicitConversionSequence::Worse;
3722
3723 return ImplicitConversionSequence::Indistinguishable;
3724}
3725
3726/// Determine whether one of the given reference bindings is better
3727/// than the other based on what kind of bindings they are.
3728static bool
3729isBetterReferenceBindingKind(const StandardConversionSequence &SCS1,
3730 const StandardConversionSequence &SCS2) {
3731 // C++0x [over.ics.rank]p3b4:
3732 // -- S1 and S2 are reference bindings (8.5.3) and neither refers to an
3733 // implicit object parameter of a non-static member function declared
3734 // without a ref-qualifier, and *either* S1 binds an rvalue reference
3735 // to an rvalue and S2 binds an lvalue reference *or S1 binds an
3736 // lvalue reference to a function lvalue and S2 binds an rvalue
3737 // reference*.
3738 //
3739 // FIXME: Rvalue references. We're going rogue with the above edits,
3740 // because the semantics in the current C++0x working paper (N3225 at the
3741 // time of this writing) break the standard definition of std::forward
3742 // and std::reference_wrapper when dealing with references to functions.
3743 // Proposed wording changes submitted to CWG for consideration.
3744 if (SCS1.BindsImplicitObjectArgumentWithoutRefQualifier ||
3745 SCS2.BindsImplicitObjectArgumentWithoutRefQualifier)
3746 return false;
3747
3748 return (!SCS1.IsLvalueReference && SCS1.BindsToRvalue &&
3749 SCS2.IsLvalueReference) ||
3750 (SCS1.IsLvalueReference && SCS1.BindsToFunctionLvalue &&
3751 !SCS2.IsLvalueReference && SCS2.BindsToFunctionLvalue);
3752}
3753
3754/// CompareStandardConversionSequences - Compare two standard
3755/// conversion sequences to determine whether one is better than the
3756/// other or if they are indistinguishable (C++ 13.3.3.2p3).
3757static ImplicitConversionSequence::CompareKind
3758CompareStandardConversionSequences(Sema &S, SourceLocation Loc,
3759 const StandardConversionSequence& SCS1,
3760 const StandardConversionSequence& SCS2)
3761{
3762 // Standard conversion sequence S1 is a better conversion sequence
3763 // than standard conversion sequence S2 if (C++ 13.3.3.2p3):
3764
3765 // -- S1 is a proper subsequence of S2 (comparing the conversion
3766 // sequences in the canonical form defined by 13.3.3.1.1,
3767 // excluding any Lvalue Transformation; the identity conversion
3768 // sequence is considered to be a subsequence of any
3769 // non-identity conversion sequence) or, if not that,
3770 if (ImplicitConversionSequence::CompareKind CK
3771 = compareStandardConversionSubsets(S.Context, SCS1, SCS2))
3772 return CK;
3773
3774 // -- the rank of S1 is better than the rank of S2 (by the rules
3775 // defined below), or, if not that,
3776 ImplicitConversionRank Rank1 = SCS1.getRank();
3777 ImplicitConversionRank Rank2 = SCS2.getRank();
3778 if (Rank1 < Rank2)
3779 return ImplicitConversionSequence::Better;
3780 else if (Rank2 < Rank1)
3781 return ImplicitConversionSequence::Worse;
3782
3783 // (C++ 13.3.3.2p4): Two conversion sequences with the same rank
3784 // are indistinguishable unless one of the following rules
3785 // applies:
3786
3787 // A conversion that is not a conversion of a pointer, or
3788 // pointer to member, to bool is better than another conversion
3789 // that is such a conversion.
3790 if (SCS1.isPointerConversionToBool() != SCS2.isPointerConversionToBool())
3791 return SCS2.isPointerConversionToBool()
3792 ? ImplicitConversionSequence::Better
3793 : ImplicitConversionSequence::Worse;
3794
3795 // C++ [over.ics.rank]p4b2:
3796 //
3797 // If class B is derived directly or indirectly from class A,
3798 // conversion of B* to A* is better than conversion of B* to
3799 // void*, and conversion of A* to void* is better than conversion
3800 // of B* to void*.
3801 bool SCS1ConvertsToVoid
3802 = SCS1.isPointerConversionToVoidPointer(S.Context);
3803 bool SCS2ConvertsToVoid
3804 = SCS2.isPointerConversionToVoidPointer(S.Context);
3805 if (SCS1ConvertsToVoid != SCS2ConvertsToVoid) {
3806 // Exactly one of the conversion sequences is a conversion to
3807 // a void pointer; it's the worse conversion.
3808 return SCS2ConvertsToVoid ? ImplicitConversionSequence::Better
3809 : ImplicitConversionSequence::Worse;
3810 } else if (!SCS1ConvertsToVoid && !SCS2ConvertsToVoid) {
3811 // Neither conversion sequence converts to a void pointer; compare
3812 // their derived-to-base conversions.
3813 if (ImplicitConversionSequence::CompareKind DerivedCK
3814 = CompareDerivedToBaseConversions(S, Loc, SCS1, SCS2))
3815 return DerivedCK;
3816 } else if (SCS1ConvertsToVoid && SCS2ConvertsToVoid &&
3817 !S.Context.hasSameType(SCS1.getFromType(), SCS2.getFromType())) {
3818 // Both conversion sequences are conversions to void
3819 // pointers. Compare the source types to determine if there's an
3820 // inheritance relationship in their sources.
3821 QualType FromType1 = SCS1.getFromType();
3822 QualType FromType2 = SCS2.getFromType();
3823
3824 // Adjust the types we're converting from via the array-to-pointer
3825 // conversion, if we need to.
3826 if (SCS1.First == ICK_Array_To_Pointer)
3827 FromType1 = S.Context.getArrayDecayedType(FromType1);
3828 if (SCS2.First == ICK_Array_To_Pointer)
3829 FromType2 = S.Context.getArrayDecayedType(FromType2);
3830
3831 QualType FromPointee1 = FromType1->getPointeeType().getUnqualifiedType();
3832 QualType FromPointee2 = FromType2->getPointeeType().getUnqualifiedType();
3833
3834 if (S.IsDerivedFrom(Loc, FromPointee2, FromPointee1))
3835 return ImplicitConversionSequence::Better;
3836 else if (S.IsDerivedFrom(Loc, FromPointee1, FromPointee2))
3837 return ImplicitConversionSequence::Worse;
3838
3839 // Objective-C++: If one interface is more specific than the
3840 // other, it is the better one.
3841 const ObjCObjectPointerType* FromObjCPtr1
3842 = FromType1->getAs<ObjCObjectPointerType>();
3843 const ObjCObjectPointerType* FromObjCPtr2
3844 = FromType2->getAs<ObjCObjectPointerType>();
3845 if (FromObjCPtr1 && FromObjCPtr2) {
3846 bool AssignLeft = S.Context.canAssignObjCInterfaces(FromObjCPtr1,
3847 FromObjCPtr2);
3848 bool AssignRight = S.Context.canAssignObjCInterfaces(FromObjCPtr2,
3849 FromObjCPtr1);
3850 if (AssignLeft != AssignRight) {
3851 return AssignLeft? ImplicitConversionSequence::Better
3852 : ImplicitConversionSequence::Worse;
3853 }
3854 }
3855 }
3856
3857 // Compare based on qualification conversions (C++ 13.3.3.2p3,
3858 // bullet 3).
3859 if (ImplicitConversionSequence::CompareKind QualCK
3860 = CompareQualificationConversions(S, SCS1, SCS2))
3861 return QualCK;
3862
3863 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding) {
3864 // Check for a better reference binding based on the kind of bindings.
3865 if (isBetterReferenceBindingKind(SCS1, SCS2))
3866 return ImplicitConversionSequence::Better;
3867 else if (isBetterReferenceBindingKind(SCS2, SCS1))
3868 return ImplicitConversionSequence::Worse;
3869
3870 // C++ [over.ics.rank]p3b4:
3871 // -- S1 and S2 are reference bindings (8.5.3), and the types to
3872 // which the references refer are the same type except for
3873 // top-level cv-qualifiers, and the type to which the reference
3874 // initialized by S2 refers is more cv-qualified than the type
3875 // to which the reference initialized by S1 refers.
3876 QualType T1 = SCS1.getToType(2);
3877 QualType T2 = SCS2.getToType(2);
3878 T1 = S.Context.getCanonicalType(T1);
3879 T2 = S.Context.getCanonicalType(T2);
3880 Qualifiers T1Quals, T2Quals;
3881 QualType UnqualT1 = S.Context.getUnqualifiedArrayType(T1, T1Quals);
3882 QualType UnqualT2 = S.Context.getUnqualifiedArrayType(T2, T2Quals);
3883 if (UnqualT1 == UnqualT2) {
3884 // Objective-C++ ARC: If the references refer to objects with different
3885 // lifetimes, prefer bindings that don't change lifetime.
3886 if (SCS1.ObjCLifetimeConversionBinding !=
3887 SCS2.ObjCLifetimeConversionBinding) {
3888 return SCS1.ObjCLifetimeConversionBinding
3889 ? ImplicitConversionSequence::Worse
3890 : ImplicitConversionSequence::Better;
3891 }
3892
3893 // If the type is an array type, promote the element qualifiers to the
3894 // type for comparison.
3895 if (isa<ArrayType>(T1) && T1Quals)
3896 T1 = S.Context.getQualifiedType(UnqualT1, T1Quals);
3897 if (isa<ArrayType>(T2) && T2Quals)
3898 T2 = S.Context.getQualifiedType(UnqualT2, T2Quals);
3899 if (T2.isMoreQualifiedThan(T1))
3900 return ImplicitConversionSequence::Better;
3901 else if (T1.isMoreQualifiedThan(T2))
3902 return ImplicitConversionSequence::Worse;
3903 }
3904 }
3905
3906 // In Microsoft mode, prefer an integral conversion to a
3907 // floating-to-integral conversion if the integral conversion
3908 // is between types of the same size.
3909 // For example:
3910 // void f(float);
3911 // void f(int);
3912 // int main {
3913 // long a;
3914 // f(a);
3915 // }
3916 // Here, MSVC will call f(int) instead of generating a compile error
3917 // as clang will do in standard mode.
3918 if (S.getLangOpts().MSVCCompat && SCS1.Second == ICK_Integral_Conversion &&
3919 SCS2.Second == ICK_Floating_Integral &&
3920 S.Context.getTypeSize(SCS1.getFromType()) ==
3921 S.Context.getTypeSize(SCS1.getToType(2)))
3922 return ImplicitConversionSequence::Better;
3923
3924 // Prefer a compatible vector conversion over a lax vector conversion
3925 // For example:
3926 //
3927 // typedef float __v4sf __attribute__((__vector_size__(16)));
3928 // void f(vector float);
3929 // void f(vector signed int);
3930 // int main() {
3931 // __v4sf a;
3932 // f(a);
3933 // }
3934 // Here, we'd like to choose f(vector float) and not
3935 // report an ambiguous call error
3936 if (SCS1.Second == ICK_Vector_Conversion &&
3937 SCS2.Second == ICK_Vector_Conversion) {
3938 bool SCS1IsCompatibleVectorConversion = S.Context.areCompatibleVectorTypes(
3939 SCS1.getFromType(), SCS1.getToType(2));
3940 bool SCS2IsCompatibleVectorConversion = S.Context.areCompatibleVectorTypes(
3941 SCS2.getFromType(), SCS2.getToType(2));
3942
3943 if (SCS1IsCompatibleVectorConversion != SCS2IsCompatibleVectorConversion)
3944 return SCS1IsCompatibleVectorConversion
3945 ? ImplicitConversionSequence::Better
3946 : ImplicitConversionSequence::Worse;
3947 }
3948
3949 return ImplicitConversionSequence::Indistinguishable;
3950}
3951
3952/// CompareQualificationConversions - Compares two standard conversion
3953/// sequences to determine whether they can be ranked based on their
3954/// qualification conversions (C++ 13.3.3.2p3 bullet 3).
3955static ImplicitConversionSequence::CompareKind
3956CompareQualificationConversions(Sema &S,
3957 const StandardConversionSequence& SCS1,
3958 const StandardConversionSequence& SCS2) {
3959 // C++ 13.3.3.2p3:
3960 // -- S1 and S2 differ only in their qualification conversion and
3961 // yield similar types T1 and T2 (C++ 4.4), respectively, and the
3962 // cv-qualification signature of type T1 is a proper subset of
3963 // the cv-qualification signature of type T2, and S1 is not the
3964 // deprecated string literal array-to-pointer conversion (4.2).
3965 if (SCS1.First != SCS2.First || SCS1.Second != SCS2.Second ||
3966 SCS1.Third != SCS2.Third || SCS1.Third != ICK_Qualification)
3967 return ImplicitConversionSequence::Indistinguishable;
3968
3969 // FIXME: the example in the standard doesn't use a qualification
3970 // conversion (!)
3971 QualType T1 = SCS1.getToType(2);
3972 QualType T2 = SCS2.getToType(2);
3973 T1 = S.Context.getCanonicalType(T1);
3974 T2 = S.Context.getCanonicalType(T2);
3975 Qualifiers T1Quals, T2Quals;
3976 QualType UnqualT1 = S.Context.getUnqualifiedArrayType(T1, T1Quals);
3977 QualType UnqualT2 = S.Context.getUnqualifiedArrayType(T2, T2Quals);
3978
3979 // If the types are the same, we won't learn anything by unwrapped
3980 // them.
3981 if (UnqualT1 == UnqualT2)
3982 return ImplicitConversionSequence::Indistinguishable;
3983
3984 // If the type is an array type, promote the element qualifiers to the type
3985 // for comparison.
3986 if (isa<ArrayType>(T1) && T1Quals)
3987 T1 = S.Context.getQualifiedType(UnqualT1, T1Quals);
3988 if (isa<ArrayType>(T2) && T2Quals)
3989 T2 = S.Context.getQualifiedType(UnqualT2, T2Quals);
3990
3991 ImplicitConversionSequence::CompareKind Result
3992 = ImplicitConversionSequence::Indistinguishable;
3993
3994 // Objective-C++ ARC:
3995 // Prefer qualification conversions not involving a change in lifetime
3996 // to qualification conversions that do not change lifetime.
3997 if (SCS1.QualificationIncludesObjCLifetime !=
3998 SCS2.QualificationIncludesObjCLifetime) {
3999 Result = SCS1.QualificationIncludesObjCLifetime
4000 ? ImplicitConversionSequence::Worse
4001 : ImplicitConversionSequence::Better;
4002 }
4003
4004 while (S.Context.UnwrapSimilarTypes(T1, T2)) {
4005 // Within each iteration of the loop, we check the qualifiers to
4006 // determine if this still looks like a qualification
4007 // conversion. Then, if all is well, we unwrap one more level of
4008 // pointers or pointers-to-members and do it all again
4009 // until there are no more pointers or pointers-to-members left
4010 // to unwrap. This essentially mimics what
4011 // IsQualificationConversion does, but here we're checking for a
4012 // strict subset of qualifiers.
4013 if (T1.getQualifiers().withoutObjCLifetime() ==
4014 T2.getQualifiers().withoutObjCLifetime())
4015 // The qualifiers are the same, so this doesn't tell us anything
4016 // about how the sequences rank.
4017 // ObjC ownership quals are omitted above as they interfere with
4018 // the ARC overload rule.
4019 ;
4020 else if (T2.isMoreQualifiedThan(T1)) {
4021 // T1 has fewer qualifiers, so it could be the better sequence.
4022 if (Result == ImplicitConversionSequence::Worse)
4023 // Neither has qualifiers that are a subset of the other's
4024 // qualifiers.
4025 return ImplicitConversionSequence::Indistinguishable;
4026
4027 Result = ImplicitConversionSequence::Better;
4028 } else if (T1.isMoreQualifiedThan(T2)) {
4029 // T2 has fewer qualifiers, so it could be the better sequence.
4030 if (Result == ImplicitConversionSequence::Better)
4031 // Neither has qualifiers that are a subset of the other's
4032 // qualifiers.
4033 return ImplicitConversionSequence::Indistinguishable;
4034
4035 Result = ImplicitConversionSequence::Worse;
4036 } else {
4037 // Qualifiers are disjoint.
4038 return ImplicitConversionSequence::Indistinguishable;
4039 }
4040
4041 // If the types after this point are equivalent, we're done.
4042 if (S.Context.hasSameUnqualifiedType(T1, T2))
4043 break;
4044 }
4045
4046 // Check that the winning standard conversion sequence isn't using
4047 // the deprecated string literal array to pointer conversion.
4048 switch (Result) {
4049 case ImplicitConversionSequence::Better:
4050 if (SCS1.DeprecatedStringLiteralToCharPtr)
4051 Result = ImplicitConversionSequence::Indistinguishable;
4052 break;
4053
4054 case ImplicitConversionSequence::Indistinguishable:
4055 break;
4056
4057 case ImplicitConversionSequence::Worse:
4058 if (SCS2.DeprecatedStringLiteralToCharPtr)
4059 Result = ImplicitConversionSequence::Indistinguishable;
4060 break;
4061 }
4062
4063 return Result;
4064}
4065
4066/// CompareDerivedToBaseConversions - Compares two standard conversion
4067/// sequences to determine whether they can be ranked based on their
4068/// various kinds of derived-to-base conversions (C++
4069/// [over.ics.rank]p4b3). As part of these checks, we also look at
4070/// conversions between Objective-C interface types.
4071static ImplicitConversionSequence::CompareKind
4072CompareDerivedToBaseConversions(Sema &S, SourceLocation Loc,
4073 const StandardConversionSequence& SCS1,
4074 const StandardConversionSequence& SCS2) {
4075 QualType FromType1 = SCS1.getFromType();
4076 QualType ToType1 = SCS1.getToType(1);
4077 QualType FromType2 = SCS2.getFromType();
4078 QualType ToType2 = SCS2.getToType(1);
4079
4080 // Adjust the types we're converting from via the array-to-pointer
4081 // conversion, if we need to.
4082 if (SCS1.First == ICK_Array_To_Pointer)
4083 FromType1 = S.Context.getArrayDecayedType(FromType1);
4084 if (SCS2.First == ICK_Array_To_Pointer)
4085 FromType2 = S.Context.getArrayDecayedType(FromType2);
4086
4087 // Canonicalize all of the types.
4088 FromType1 = S.Context.getCanonicalType(FromType1);
4089 ToType1 = S.Context.getCanonicalType(ToType1);
4090 FromType2 = S.Context.getCanonicalType(FromType2);
4091 ToType2 = S.Context.getCanonicalType(ToType2);
4092
4093 // C++ [over.ics.rank]p4b3:
4094 //
4095 // If class B is derived directly or indirectly from class A and
4096 // class C is derived directly or indirectly from B,
4097 //
4098 // Compare based on pointer conversions.
4099 if (SCS1.Second == ICK_Pointer_Conversion &&
4100 SCS2.Second == ICK_Pointer_Conversion &&
4101 /*FIXME: Remove if Objective-C id conversions get their own rank*/
4102 FromType1->isPointerType() && FromType2->isPointerType() &&
4103 ToType1->isPointerType() && ToType2->isPointerType()) {
4104 QualType FromPointee1
4105 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType();
4106 QualType ToPointee1
4107 = ToType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType();
4108 QualType FromPointee2
4109 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType();
4110 QualType ToPointee2
4111 = ToType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType();
4112
4113 // -- conversion of C* to B* is better than conversion of C* to A*,
4114 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) {
4115 if (S.IsDerivedFrom(Loc, ToPointee1, ToPointee2))
4116 return ImplicitConversionSequence::Better;
4117 else if (S.IsDerivedFrom(Loc, ToPointee2, ToPointee1))
4118 return ImplicitConversionSequence::Worse;
4119 }
4120
4121 // -- conversion of B* to A* is better than conversion of C* to A*,
4122 if (FromPointee1 != FromPointee2 && ToPointee1 == ToPointee2) {
4123 if (S.IsDerivedFrom(Loc, FromPointee2, FromPointee1))
4124 return ImplicitConversionSequence::Better;
4125 else if (S.IsDerivedFrom(Loc, FromPointee1, FromPointee2))
4126 return ImplicitConversionSequence::Worse;
4127 }
4128 } else if (SCS1.Second == ICK_Pointer_Conversion &&
4129 SCS2.Second == ICK_Pointer_Conversion) {
4130 const ObjCObjectPointerType *FromPtr1
4131 = FromType1->getAs<ObjCObjectPointerType>();
4132 const ObjCObjectPointerType *FromPtr2
4133 = FromType2->getAs<ObjCObjectPointerType>();
4134 const ObjCObjectPointerType *ToPtr1
4135 = ToType1->getAs<ObjCObjectPointerType>();
4136 const ObjCObjectPointerType *ToPtr2
4137 = ToType2->getAs<ObjCObjectPointerType>();
4138
4139 if (FromPtr1 && FromPtr2 && ToPtr1 && ToPtr2) {
4140 // Apply the same conversion ranking rules for Objective-C pointer types
4141 // that we do for C++ pointers to class types. However, we employ the
4142 // Objective-C pseudo-subtyping relationship used for assignment of
4143 // Objective-C pointer types.
4144 bool FromAssignLeft
4145 = S.Context.canAssignObjCInterfaces(FromPtr1, FromPtr2);
4146 bool FromAssignRight
4147 = S.Context.canAssignObjCInterfaces(FromPtr2, FromPtr1);
4148 bool ToAssignLeft
4149 = S.Context.canAssignObjCInterfaces(ToPtr1, ToPtr2);
4150 bool ToAssignRight
4151 = S.Context.canAssignObjCInterfaces(ToPtr2, ToPtr1);
4152
4153 // A conversion to an a non-id object pointer type or qualified 'id'
4154 // type is better than a conversion to 'id'.
4155 if (ToPtr1->isObjCIdType() &&
4156 (ToPtr2->isObjCQualifiedIdType() || ToPtr2->getInterfaceDecl()))
4157 return ImplicitConversionSequence::Worse;
4158 if (ToPtr2->isObjCIdType() &&
4159 (ToPtr1->isObjCQualifiedIdType() || ToPtr1->getInterfaceDecl()))
4160 return ImplicitConversionSequence::Better;
4161
4162 // A conversion to a non-id object pointer type is better than a
4163 // conversion to a qualified 'id' type
4164 if (ToPtr1->isObjCQualifiedIdType() && ToPtr2->getInterfaceDecl())
4165 return ImplicitConversionSequence::Worse;
4166 if (ToPtr2->isObjCQualifiedIdType() && ToPtr1->getInterfaceDecl())
4167 return ImplicitConversionSequence::Better;
4168
4169 // A conversion to an a non-Class object pointer type or qualified 'Class'
4170 // type is better than a conversion to 'Class'.
4171 if (ToPtr1->isObjCClassType() &&
4172 (ToPtr2->isObjCQualifiedClassType() || ToPtr2->getInterfaceDecl()))
4173 return ImplicitConversionSequence::Worse;
4174 if (ToPtr2->isObjCClassType() &&
4175 (ToPtr1->isObjCQualifiedClassType() || ToPtr1->getInterfaceDecl()))
4176 return ImplicitConversionSequence::Better;
4177
4178 // A conversion to a non-Class object pointer type is better than a
4179 // conversion to a qualified 'Class' type.
4180 if (ToPtr1->isObjCQualifiedClassType() && ToPtr2->getInterfaceDecl())
4181 return ImplicitConversionSequence::Worse;
4182 if (ToPtr2->isObjCQualifiedClassType() && ToPtr1->getInterfaceDecl())
4183 return ImplicitConversionSequence::Better;
4184
4185 // -- "conversion of C* to B* is better than conversion of C* to A*,"
4186 if (S.Context.hasSameType(FromType1, FromType2) &&
4187 !FromPtr1->isObjCIdType() && !FromPtr1->isObjCClassType() &&
4188 (ToAssignLeft != ToAssignRight)) {
4189 if (FromPtr1->isSpecialized()) {
4190 // "conversion of B<A> * to B * is better than conversion of B * to
4191 // C *.
4192 bool IsFirstSame =
4193 FromPtr1->getInterfaceDecl() == ToPtr1->getInterfaceDecl();
4194 bool IsSecondSame =
4195 FromPtr1->getInterfaceDecl() == ToPtr2->getInterfaceDecl();
4196 if (IsFirstSame) {
4197 if (!IsSecondSame)
4198 return ImplicitConversionSequence::Better;
4199 } else if (IsSecondSame)
4200 return ImplicitConversionSequence::Worse;
4201 }
4202 return ToAssignLeft? ImplicitConversionSequence::Worse
4203 : ImplicitConversionSequence::Better;
4204 }
4205
4206 // -- "conversion of B* to A* is better than conversion of C* to A*,"
4207 if (S.Context.hasSameUnqualifiedType(ToType1, ToType2) &&
4208 (FromAssignLeft != FromAssignRight))
4209 return FromAssignLeft? ImplicitConversionSequence::Better
4210 : ImplicitConversionSequence::Worse;
4211 }
4212 }
4213
4214 // Ranking of member-pointer types.
4215 if (SCS1.Second == ICK_Pointer_Member && SCS2.Second == ICK_Pointer_Member &&
4216 FromType1->isMemberPointerType() && FromType2->isMemberPointerType() &&
4217 ToType1->isMemberPointerType() && ToType2->isMemberPointerType()) {
4218 const MemberPointerType * FromMemPointer1 =
4219 FromType1->getAs<MemberPointerType>();
4220 const MemberPointerType * ToMemPointer1 =
4221 ToType1->getAs<MemberPointerType>();
4222 const MemberPointerType * FromMemPointer2 =
4223 FromType2->getAs<MemberPointerType>();
4224 const MemberPointerType * ToMemPointer2 =
4225 ToType2->getAs<MemberPointerType>();
4226 const Type *FromPointeeType1 = FromMemPointer1->getClass();
4227 const Type *ToPointeeType1 = ToMemPointer1->getClass();
4228 const Type *FromPointeeType2 = FromMemPointer2->getClass();
4229 const Type *ToPointeeType2 = ToMemPointer2->getClass();
4230 QualType FromPointee1 = QualType(FromPointeeType1, 0).getUnqualifiedType();
4231 QualType ToPointee1 = QualType(ToPointeeType1, 0).getUnqualifiedType();
4232 QualType FromPointee2 = QualType(FromPointeeType2, 0).getUnqualifiedType();
4233 QualType ToPointee2 = QualType(ToPointeeType2, 0).getUnqualifiedType();
4234 // conversion of A::* to B::* is better than conversion of A::* to C::*,
4235 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) {
4236 if (S.IsDerivedFrom(Loc, ToPointee1, ToPointee2))
4237 return ImplicitConversionSequence::Worse;
4238 else if (S.IsDerivedFrom(Loc, ToPointee2, ToPointee1))
4239 return ImplicitConversionSequence::Better;
4240 }
4241 // conversion of B::* to C::* is better than conversion of A::* to C::*
4242 if (ToPointee1 == ToPointee2 && FromPointee1 != FromPointee2) {
4243 if (S.IsDerivedFrom(Loc, FromPointee1, FromPointee2))
4244 return ImplicitConversionSequence::Better;
4245 else if (S.IsDerivedFrom(Loc, FromPointee2, FromPointee1))
4246 return ImplicitConversionSequence::Worse;
4247 }
4248 }
4249
4250 if (SCS1.Second == ICK_Derived_To_Base) {
4251 // -- conversion of C to B is better than conversion of C to A,
4252 // -- binding of an expression of type C to a reference of type
4253 // B& is better than binding an expression of type C to a
4254 // reference of type A&,
4255 if (S.Context.hasSameUnqualifiedType(FromType1, FromType2) &&
4256 !S.Context.hasSameUnqualifiedType(ToType1, ToType2)) {
4257 if (S.IsDerivedFrom(Loc, ToType1, ToType2))
4258 return ImplicitConversionSequence::Better;
4259 else if (S.IsDerivedFrom(Loc, ToType2, ToType1))
4260 return ImplicitConversionSequence::Worse;
4261 }
4262
4263 // -- conversion of B to A is better than conversion of C to A.
4264 // -- binding of an expression of type B to a reference of type
4265 // A& is better than binding an expression of type C to a
4266 // reference of type A&,
4267 if (!S.Context.hasSameUnqualifiedType(FromType1, FromType2) &&
4268 S.Context.hasSameUnqualifiedType(ToType1, ToType2)) {
4269 if (S.IsDerivedFrom(Loc, FromType2, FromType1))
4270 return ImplicitConversionSequence::Better;
4271 else if (S.IsDerivedFrom(Loc, FromType1, FromType2))
4272 return ImplicitConversionSequence::Worse;
4273 }
4274 }
4275
4276 return ImplicitConversionSequence::Indistinguishable;
4277}
4278
4279/// Determine whether the given type is valid, e.g., it is not an invalid
4280/// C++ class.
4281static bool isTypeValid(QualType T) {
4282 if (CXXRecordDecl *Record = T->getAsCXXRecordDecl())
4283 return !Record->isInvalidDecl();
4284
4285 return true;
4286}
4287
4288/// CompareReferenceRelationship - Compare the two types T1 and T2 to
4289/// determine whether they are reference-related,
4290/// reference-compatible, reference-compatible with added
4291/// qualification, or incompatible, for use in C++ initialization by
4292/// reference (C++ [dcl.ref.init]p4). Neither type can be a reference
4293/// type, and the first type (T1) is the pointee type of the reference
4294/// type being initialized.
4295Sema::ReferenceCompareResult
4296Sema::CompareReferenceRelationship(SourceLocation Loc,
4297 QualType OrigT1, QualType OrigT2,
4298 bool &DerivedToBase,
4299 bool &ObjCConversion,
4300 bool &ObjCLifetimeConversion) {
4301 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-9~svn360825/tools/clang/lib/Sema/SemaOverload.cpp"
, 4302, __PRETTY_FUNCTION__))
4302 "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-9~svn360825/tools/clang/lib/Sema/SemaOverload.cpp"
, 4302, __PRETTY_FUNCTION__))
;
4303 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-9~svn360825/tools/clang/lib/Sema/SemaOverload.cpp"
, 4303, __PRETTY_FUNCTION__))
;
4304
4305 QualType T1 = Context.getCanonicalType(OrigT1);
4306 QualType T2 = Context.getCanonicalType(OrigT2);
4307 Qualifiers T1Quals, T2Quals;
4308 QualType UnqualT1 = Context.getUnqualifiedArrayType(T1, T1Quals);
4309 QualType UnqualT2 = Context.getUnqualifiedArrayType(T2, T2Quals);
4310
4311 // C++ [dcl.init.ref]p4:
4312 // Given types "cv1 T1" and "cv2 T2," "cv1 T1" is
4313 // reference-related to "cv2 T2" if T1 is the same type as T2, or
4314 // T1 is a base class of T2.
4315 DerivedToBase = false;
4316 ObjCConversion = false;
4317 ObjCLifetimeConversion = false;
4318 QualType ConvertedT2;
4319 if (UnqualT1 == UnqualT2) {
4320 // Nothing to do.
4321 } else if (isCompleteType(Loc, OrigT2) &&
4322 isTypeValid(UnqualT1) && isTypeValid(UnqualT2) &&
4323 IsDerivedFrom(Loc, UnqualT2, UnqualT1))
4324 DerivedToBase = true;
4325 else if (UnqualT1->isObjCObjectOrInterfaceType() &&
4326 UnqualT2->isObjCObjectOrInterfaceType() &&
4327 Context.canBindObjCObjectType(UnqualT1, UnqualT2))
4328 ObjCConversion = true;
4329 else if (UnqualT2->isFunctionType() &&
4330 IsFunctionConversion(UnqualT2, UnqualT1, ConvertedT2))
4331 // C++1z [dcl.init.ref]p4:
4332 // cv1 T1" is reference-compatible with "cv2 T2" if [...] T2 is "noexcept
4333 // function" and T1 is "function"
4334 //
4335 // We extend this to also apply to 'noreturn', so allow any function
4336 // conversion between function types.
4337 return Ref_Compatible;
4338 else
4339 return Ref_Incompatible;
4340
4341 // At this point, we know that T1 and T2 are reference-related (at
4342 // least).
4343
4344 // If the type is an array type, promote the element qualifiers to the type
4345 // for comparison.
4346 if (isa<ArrayType>(T1) && T1Quals)
4347 T1 = Context.getQualifiedType(UnqualT1, T1Quals);
4348 if (isa<ArrayType>(T2) && T2Quals)
4349 T2 = Context.getQualifiedType(UnqualT2, T2Quals);
4350
4351 // C++ [dcl.init.ref]p4:
4352 // "cv1 T1" is reference-compatible with "cv2 T2" if T1 is
4353 // reference-related to T2 and cv1 is the same cv-qualification
4354 // as, or greater cv-qualification than, cv2. For purposes of
4355 // overload resolution, cases for which cv1 is greater
4356 // cv-qualification than cv2 are identified as
4357 // reference-compatible with added qualification (see 13.3.3.2).
4358 //
4359 // Note that we also require equivalence of Objective-C GC and address-space
4360 // qualifiers when performing these computations, so that e.g., an int in
4361 // address space 1 is not reference-compatible with an int in address
4362 // space 2.
4363 if (T1Quals.getObjCLifetime() != T2Quals.getObjCLifetime() &&
4364 T1Quals.compatiblyIncludesObjCLifetime(T2Quals)) {
4365 if (isNonTrivialObjCLifetimeConversion(T2Quals, T1Quals))
4366 ObjCLifetimeConversion = true;
4367
4368 T1Quals.removeObjCLifetime();
4369 T2Quals.removeObjCLifetime();
4370 }
4371
4372 // MS compiler ignores __unaligned qualifier for references; do the same.
4373 T1Quals.removeUnaligned();
4374 T2Quals.removeUnaligned();
4375
4376 if (T1Quals.compatiblyIncludes(T2Quals))
4377 return Ref_Compatible;
4378 else
4379 return Ref_Related;
4380}
4381
4382/// Look for a user-defined conversion to a value reference-compatible
4383/// with DeclType. Return true if something definite is found.
4384static bool
4385FindConversionForRefInit(Sema &S, ImplicitConversionSequence &ICS,
4386 QualType DeclType, SourceLocation DeclLoc,
4387 Expr *Init, QualType T2, bool AllowRvalues,
4388 bool AllowExplicit) {
4389 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-9~svn360825/tools/clang/lib/Sema/SemaOverload.cpp"
, 4389, __PRETTY_FUNCTION__))
;
4390 CXXRecordDecl *T2RecordDecl
4391 = dyn_cast<CXXRecordDecl>(T2->getAs<RecordType>()->getDecl());
4392
4393 OverloadCandidateSet CandidateSet(
4394 DeclLoc, OverloadCandidateSet::CSK_InitByUserDefinedConversion);
4395 const auto &Conversions = T2RecordDecl->getVisibleConversionFunctions();
4396 for (auto I = Conversions.begin(), E = Conversions.end(); I != E; ++I) {
4397 NamedDecl *D = *I;
4398 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(D->getDeclContext());
4399 if (isa<UsingShadowDecl>(D))
4400 D = cast<UsingShadowDecl>(D)->getTargetDecl();
4401
4402 FunctionTemplateDecl *ConvTemplate
4403 = dyn_cast<FunctionTemplateDecl>(D);
4404 CXXConversionDecl *Conv;
4405 if (ConvTemplate)
4406 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl());
4407 else
4408 Conv = cast<CXXConversionDecl>(D);
4409
4410 // If this is an explicit conversion, and we're not allowed to consider
4411 // explicit conversions, skip it.
4412 if (!AllowExplicit && Conv->isExplicit())
4413 continue;
4414
4415 if (AllowRvalues) {
4416 bool DerivedToBase = false;
4417 bool ObjCConversion = false;
4418 bool ObjCLifetimeConversion = false;
4419
4420 // If we are initializing an rvalue reference, don't permit conversion
4421 // functions that return lvalues.
4422 if (!ConvTemplate && DeclType->isRValueReferenceType()) {
4423 const ReferenceType *RefType
4424 = Conv->getConversionType()->getAs<LValueReferenceType>();
4425 if (RefType && !RefType->getPointeeType()->isFunctionType())
4426 continue;
4427 }
4428
4429 if (!ConvTemplate &&
4430 S.CompareReferenceRelationship(
4431 DeclLoc,
4432 Conv->getConversionType().getNonReferenceType()
4433 .getUnqualifiedType(),
4434 DeclType.getNonReferenceType().getUnqualifiedType(),
4435 DerivedToBase, ObjCConversion, ObjCLifetimeConversion) ==
4436 Sema::Ref_Incompatible)
4437 continue;
4438 } else {
4439 // If the conversion function doesn't return a reference type,
4440 // it can't be considered for this conversion. An rvalue reference
4441 // is only acceptable if its referencee is a function type.
4442
4443 const ReferenceType *RefType =
4444 Conv->getConversionType()->getAs<ReferenceType>();
4445 if (!RefType ||
4446 (!RefType->isLValueReferenceType() &&
4447 !RefType->getPointeeType()->isFunctionType()))
4448 continue;
4449 }
4450
4451 if (ConvTemplate)
4452 S.AddTemplateConversionCandidate(
4453 ConvTemplate, I.getPair(), ActingDC, Init, DeclType, CandidateSet,
4454 /*AllowObjCConversionOnExplicit=*/false, AllowExplicit);
4455 else
4456 S.AddConversionCandidate(
4457 Conv, I.getPair(), ActingDC, Init, DeclType, CandidateSet,
4458 /*AllowObjCConversionOnExplicit=*/false, AllowExplicit);
4459 }
4460
4461 bool HadMultipleCandidates = (CandidateSet.size() > 1);
4462
4463 OverloadCandidateSet::iterator Best;
4464 switch (CandidateSet.BestViableFunction(S, DeclLoc, Best)) {
4465 case OR_Success:
4466 // C++ [over.ics.ref]p1:
4467 //
4468 // [...] If the parameter binds directly to the result of
4469 // applying a conversion function to the argument
4470 // expression, the implicit conversion sequence is a
4471 // user-defined conversion sequence (13.3.3.1.2), with the
4472 // second standard conversion sequence either an identity
4473 // conversion or, if the conversion function returns an
4474 // entity of a type that is a derived class of the parameter
4475 // type, a derived-to-base Conversion.
4476 if (!Best->FinalConversion.DirectBinding)
4477 return false;
4478
4479 ICS.setUserDefined();
4480 ICS.UserDefined.Before = Best->Conversions[0].Standard;
4481 ICS.UserDefined.After = Best->FinalConversion;
4482 ICS.UserDefined.HadMultipleCandidates = HadMultipleCandidates;
4483 ICS.UserDefined.ConversionFunction = Best->Function;
4484 ICS.UserDefined.FoundConversionFunction = Best->FoundDecl;
4485 ICS.UserDefined.EllipsisConversion = false;
4486 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-9~svn360825/tools/clang/lib/Sema/SemaOverload.cpp"
, 4488, __PRETTY_FUNCTION__))
4487 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-9~svn360825/tools/clang/lib/Sema/SemaOverload.cpp"
, 4488, __PRETTY_FUNCTION__))
4488 "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-9~svn360825/tools/clang/lib/Sema/SemaOverload.cpp"
, 4488, __PRETTY_FUNCTION__))
;
4489 return true;
4490
4491 case OR_Ambiguous:
4492 ICS.setAmbiguous();
4493 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin();
4494 Cand != CandidateSet.end(); ++Cand)
4495 if (Cand->Viable)
4496 ICS.Ambiguous.addConversion(Cand->FoundDecl, Cand->Function);
4497 return true;
4498
4499 case OR_No_Viable_Function:
4500 case OR_Deleted:
4501 // There was no suitable conversion, or we found a deleted
4502 // conversion; continue with other checks.
4503 return false;
4504 }
4505
4506 llvm_unreachable("Invalid OverloadResult!")::llvm::llvm_unreachable_internal("Invalid OverloadResult!", "/build/llvm-toolchain-snapshot-9~svn360825/tools/clang/lib/Sema/SemaOverload.cpp"
, 4506)
;
4507}
4508
4509/// Compute an implicit conversion sequence for reference
4510/// initialization.
4511static ImplicitConversionSequence
4512TryReferenceInit(Sema &S, Expr *Init, QualType DeclType,
4513 SourceLocation DeclLoc,
4514 bool SuppressUserConversions,
4515 bool AllowExplicit) {
4516 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-9~svn360825/tools/clang/lib/Sema/SemaOverload.cpp"
, 4516, __PRETTY_FUNCTION__))
;
4517
4518 // Most paths end in a failed conversion.
4519 ImplicitConversionSequence ICS;
4520 ICS.setBad(BadConversionSequence::no_conversion, Init, DeclType);
4521
4522 QualType T1 = DeclType->getAs<ReferenceType>()->getPointeeType();
4523 QualType T2 = Init->getType();
4524
4525 // If the initializer is the address of an overloaded function, try
4526 // to resolve the overloaded function. If all goes well, T2 is the
4527 // type of the resulting function.
4528 if (S.Context.getCanonicalType(T2) == S.Context.OverloadTy) {
4529 DeclAccessPair Found;
4530 if (FunctionDecl *Fn = S.ResolveAddressOfOverloadedFunction(Init, DeclType,
4531 false, Found))
4532 T2 = Fn->getType();
4533 }
4534
4535 // Compute some basic properties of the types and the initializer.
4536 bool isRValRef = DeclType->isRValueReferenceType();
4537 bool DerivedToBase = false;
4538 bool ObjCConversion = false;
4539 bool ObjCLifetimeConversion = false;
4540 Expr::Classification InitCategory = Init->Classify(S.Context);
4541 Sema::ReferenceCompareResult RefRelationship
4542 = S.CompareReferenceRelationship(DeclLoc, T1, T2, DerivedToBase,
4543 ObjCConversion, ObjCLifetimeConversion);
4544
4545
4546 // C++0x [dcl.init.ref]p5:
4547 // A reference to type "cv1 T1" is initialized by an expression
4548 // of type "cv2 T2" as follows:
4549
4550 // -- If reference is an lvalue reference and the initializer expression
4551 if (!isRValRef) {
4552 // -- is an lvalue (but is not a bit-field), and "cv1 T1" is
4553 // reference-compatible with "cv2 T2," or
4554 //
4555 // Per C++ [over.ics.ref]p4, we don't check the bit-field property here.
4556 if (InitCategory.isLValue() && RefRelationship == Sema::Ref_Compatible) {
4557 // C++ [over.ics.ref]p1:
4558 // When a parameter of reference type binds directly (8.5.3)
4559 // to an argument expression, the implicit conversion sequence
4560 // is the identity conversion, unless the argument expression
4561 // has a type that is a derived class of the parameter type,
4562 // in which case the implicit conversion sequence is a
4563 // derived-to-base Conversion (13.3.3.1).
4564 ICS.setStandard();
4565 ICS.Standard.First = ICK_Identity;
4566 ICS.Standard.Second = DerivedToBase? ICK_Derived_To_Base
4567 : ObjCConversion? ICK_Compatible_Conversion
4568 : ICK_Identity;
4569 ICS.Standard.Third = ICK_Identity;
4570 ICS.Standard.FromTypePtr = T2.getAsOpaquePtr();
4571 ICS.Standard.setToType(0, T2);
4572 ICS.Standard.setToType(1, T1);
4573 ICS.Standard.setToType(2, T1);
4574 ICS.Standard.ReferenceBinding = true;
4575 ICS.Standard.DirectBinding = true;
4576 ICS.Standard.IsLvalueReference = !isRValRef;
4577 ICS.Standard.BindsToFunctionLvalue = T2->isFunctionType();
4578 ICS.Standard.BindsToRvalue = false;
4579 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier = false;
4580 ICS.Standard.ObjCLifetimeConversionBinding = ObjCLifetimeConversion;
4581 ICS.Standard.CopyConstructor = nullptr;
4582 ICS.Standard.DeprecatedStringLiteralToCharPtr = false;
4583
4584 // Nothing more to do: the inaccessibility/ambiguity check for
4585 // derived-to-base conversions is suppressed when we're
4586 // computing the implicit conversion sequence (C++
4587 // [over.best.ics]p2).
4588 return ICS;
4589 }
4590
4591 // -- has a class type (i.e., T2 is a class type), where T1 is
4592 // not reference-related to T2, and can be implicitly
4593 // converted to an lvalue of type "cv3 T3," where "cv1 T1"
4594 // is reference-compatible with "cv3 T3" 92) (this
4595 // conversion is selected by enumerating the applicable
4596 // conversion functions (13.3.1.6) and choosing the best
4597 // one through overload resolution (13.3)),
4598 if (!SuppressUserConversions && T2->isRecordType() &&
4599 S.isCompleteType(DeclLoc, T2) &&
4600 RefRelationship == Sema::Ref_Incompatible) {
4601 if (FindConversionForRefInit(S, ICS, DeclType, DeclLoc,
4602 Init, T2, /*AllowRvalues=*/false,
4603 AllowExplicit))
4604 return ICS;
4605 }
4606 }
4607
4608 // -- Otherwise, the reference shall be an lvalue reference to a
4609 // non-volatile const type (i.e., cv1 shall be const), or the reference
4610 // shall be an rvalue reference.
4611 if (!isRValRef && (!T1.isConstQualified() || T1.isVolatileQualified()))
4612 return ICS;
4613
4614 // -- If the initializer expression
4615 //
4616 // -- is an xvalue, class prvalue, array prvalue or function
4617 // lvalue and "cv1 T1" is reference-compatible with "cv2 T2", or
4618 if (RefRelationship == Sema::Ref_Compatible &&
4619 (InitCategory.isXValue() ||
4620 (InitCategory.isPRValue() && (T2->isRecordType() || T2->isArrayType())) ||
4621 (InitCategory.isLValue() && T2->isFunctionType()))) {
4622 ICS.setStandard();
4623 ICS.Standard.First = ICK_Identity;
4624 ICS.Standard.Second = DerivedToBase? ICK_Derived_To_Base
4625 : ObjCConversion? ICK_Compatible_Conversion
4626 : ICK_Identity;
4627 ICS.Standard.Third = ICK_Identity;
4628 ICS.Standard.FromTypePtr = T2.getAsOpaquePtr();
4629 ICS.Standard.setToType(0, T2);
4630 ICS.Standard.setToType(1, T1);
4631 ICS.Standard.setToType(2, T1);
4632 ICS.Standard.ReferenceBinding = true;
4633 // In C++0x, this is always a direct binding. In C++98/03, it's a direct
4634 // binding unless we're binding to a class prvalue.
4635 // Note: Although xvalues wouldn't normally show up in C++98/03 code, we
4636 // allow the use of rvalue references in C++98/03 for the benefit of
4637 // standard library implementors; therefore, we need the xvalue check here.
4638 ICS.Standard.DirectBinding =
4639 S.getLangOpts().CPlusPlus11 ||
4640 !(InitCategory.isPRValue() || T2->isRecordType());
4641 ICS.Standard.IsLvalueReference = !isRValRef;
4642 ICS.Standard.BindsToFunctionLvalue = T2->isFunctionType();
4643 ICS.Standard.BindsToRvalue = InitCategory.isRValue();
4644 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier = false;
4645 ICS.Standard.ObjCLifetimeConversionBinding = ObjCLifetimeConversion;
4646 ICS.Standard.CopyConstructor = nullptr;
4647 ICS.Standard.DeprecatedStringLiteralToCharPtr = false;
4648 return ICS;
4649 }
4650
4651 // -- has a class type (i.e., T2 is a class type), where T1 is not
4652 // reference-related to T2, and can be implicitly converted to
4653 // an xvalue, class prvalue, or function lvalue of type
4654 // "cv3 T3", where "cv1 T1" is reference-compatible with
4655 // "cv3 T3",
4656 //
4657 // then the reference is bound to the value of the initializer
4658 // expression in the first case and to the result of the conversion
4659 // in the second case (or, in either case, to an appropriate base
4660 // class subobject).
4661 if (!SuppressUserConversions && RefRelationship == Sema::Ref_Incompatible &&
4662 T2->isRecordType() && S.isCompleteType(DeclLoc, T2) &&
4663 FindConversionForRefInit(S, ICS, DeclType, DeclLoc,
4664 Init, T2, /*AllowRvalues=*/true,
4665 AllowExplicit)) {
4666 // In the second case, if the reference is an rvalue reference
4667 // and the second standard conversion sequence of the
4668 // user-defined conversion sequence includes an lvalue-to-rvalue
4669 // conversion, the program is ill-formed.
4670 if (ICS.isUserDefined() && isRValRef &&
4671 ICS.UserDefined.After.First == ICK_Lvalue_To_Rvalue)
4672 ICS.setBad(BadConversionSequence::no_conversion, Init, DeclType);
4673
4674 return ICS;
4675 }
4676
4677 // A temporary of function type cannot be created; don't even try.
4678 if (T1->isFunctionType())
4679 return ICS;
4680
4681 // -- Otherwise, a temporary of type "cv1 T1" is created and
4682 // initialized from the initializer expression using the
4683 // rules for a non-reference copy initialization (8.5). The
4684 // reference is then bound to the temporary. If T1 is
4685 // reference-related to T2, cv1 must be the same
4686 // cv-qualification as, or greater cv-qualification than,
4687 // cv2; otherwise, the program is ill-formed.
4688 if (RefRelationship == Sema::Ref_Related) {
4689 // If cv1 == cv2 or cv1 is a greater cv-qualified than cv2, then
4690 // we would be reference-compatible or reference-compatible with
4691 // added qualification. But that wasn't the case, so the reference
4692 // initialization fails.
4693 //
4694 // Note that we only want to check address spaces and cvr-qualifiers here.
4695 // ObjC GC, lifetime and unaligned qualifiers aren't important.
4696 Qualifiers T1Quals = T1.getQualifiers();
4697 Qualifiers T2Quals = T2.getQualifiers();
4698 T1Quals.removeObjCGCAttr();
4699 T1Quals.removeObjCLifetime();
4700 T2Quals.removeObjCGCAttr();
4701 T2Quals.removeObjCLifetime();
4702 // MS compiler ignores __unaligned qualifier for references; do the same.
4703 T1Quals.removeUnaligned();
4704 T2Quals.removeUnaligned();
4705 if (!T1Quals.compatiblyIncludes(T2Quals))
4706 return ICS;
4707 }
4708
4709 // If at least one of the types is a class type, the types are not
4710 // related, and we aren't allowed any user conversions, the
4711 // reference binding fails. This case is important for breaking
4712 // recursion, since TryImplicitConversion below will attempt to
4713 // create a temporary through the use of a copy constructor.
4714 if (SuppressUserConversions && RefRelationship == Sema::Ref_Incompatible &&
4715 (T1->isRecordType() || T2->isRecordType()))
4716 return ICS;
4717
4718 // If T1 is reference-related to T2 and the reference is an rvalue
4719 // reference, the initializer expression shall not be an lvalue.
4720 if (RefRelationship >= Sema::Ref_Related &&
4721 isRValRef && Init->Classify(S.Context).isLValue())
4722 return ICS;
4723
4724 // C++ [over.ics.ref]p2:
4725 // When a parameter of reference type is not bound directly to
4726 // an argument expression, the conversion sequence is the one
4727 // required to convert the argument expression to the
4728 // underlying type of the reference according to
4729 // 13.3.3.1. Conceptually, this conversion sequence corresponds
4730 // to copy-initializing a temporary of the underlying type with
4731 // the argument expression. Any difference in top-level
4732 // cv-qualification is subsumed by the initialization itself
4733 // and does not constitute a conversion.
4734 ICS = TryImplicitConversion(S, Init, T1, SuppressUserConversions,
4735 /*AllowExplicit=*/false,
4736 /*InOverloadResolution=*/false,
4737 /*CStyle=*/false,
4738 /*AllowObjCWritebackConversion=*/false,
4739 /*AllowObjCConversionOnExplicit=*/false);
4740
4741 // Of course, that's still a reference binding.
4742 if (ICS.isStandard()) {
4743 ICS.Standard.ReferenceBinding = true;
4744 ICS.Standard.IsLvalueReference = !isRValRef;
4745 ICS.Standard.BindsToFunctionLvalue = false;
4746 ICS.Standard.BindsToRvalue = true;
4747 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier = false;
4748 ICS.Standard.ObjCLifetimeConversionBinding = false;
4749 } else if (ICS.isUserDefined()) {
4750 const ReferenceType *LValRefType =
4751 ICS.UserDefined.ConversionFunction->getReturnType()
4752 ->getAs<LValueReferenceType>();
4753
4754 // C++ [over.ics.ref]p3:
4755 // Except for an implicit object parameter, for which see 13.3.1, a
4756 // standard conversion sequence cannot be formed if it requires [...]
4757 // binding an rvalue reference to an lvalue other than a function
4758 // lvalue.
4759 // Note that the function case is not possible here.
4760 if (DeclType->isRValueReferenceType() && LValRefType) {
4761 // FIXME: This is the wrong BadConversionSequence. The problem is binding
4762 // an rvalue reference to a (non-function) lvalue, not binding an lvalue
4763 // reference to an rvalue!
4764 ICS.setBad(BadConversionSequence::lvalue_ref_to_rvalue, Init, DeclType);
4765 return ICS;
4766 }
4767
4768 ICS.UserDefined.After.ReferenceBinding = true;
4769 ICS.UserDefined.After.IsLvalueReference = !isRValRef;
4770 ICS.UserDefined.After.BindsToFunctionLvalue = false;
4771 ICS.UserDefined.After.BindsToRvalue = !LValRefType;
4772 ICS.UserDefined.After.BindsImplicitObjectArgumentWithoutRefQualifier = false;
4773 ICS.UserDefined.After.ObjCLifetimeConversionBinding = false;
4774 }
4775
4776 return ICS;
4777}
4778
4779static ImplicitConversionSequence
4780TryCopyInitialization(Sema &S, Expr *From, QualType ToType,
4781 bool SuppressUserConversions,
4782 bool InOverloadResolution,
4783 bool AllowObjCWritebackConversion,
4784 bool AllowExplicit = false);
4785
4786/// TryListConversion - Try to copy-initialize a value of type ToType from the
4787/// initializer list From.
4788static ImplicitConversionSequence
4789TryListConversion(Sema &S, InitListExpr *From, QualType ToType,
4790 bool SuppressUserConversions,
4791 bool InOverloadResolution,
4792 bool AllowObjCWritebackConversion) {
4793 // C++11 [over.ics.list]p1:
4794 // When an argument is an initializer list, it is not an expression and
4795 // special rules apply for converting it to a parameter type.
4796
4797 ImplicitConversionSequence Result;
4798 Result.setBad(BadConversionSequence::no_conversion, From, ToType);
4799
4800 // We need a complete type for what follows. Incomplete types can never be
4801 // initialized from init lists.
4802 if (!S.isCompleteType(From->getBeginLoc(), ToType))
4803 return Result;
4804
4805 // Per DR1467:
4806 // If the parameter type is a class X and the initializer list has a single
4807 // element of type cv U, where U is X or a class derived from X, the
4808 // implicit conversion sequence is the one required to convert the element
4809 // to the parameter type.
4810 //
4811 // Otherwise, if the parameter type is a character array [... ]
4812 // and the initializer list has a single element that is an
4813 // appropriately-typed string literal (8.5.2 [dcl.init.string]), the
4814 // implicit conversion sequence is the identity conversion.
4815 if (From->getNumInits() == 1) {
4816 if (ToType->isRecordType()) {
4817 QualType InitType = From->getInit(0)->getType();
4818 if (S.Context.hasSameUnqualifiedType(InitType, ToType) ||
4819 S.IsDerivedFrom(From->getBeginLoc(), InitType, ToType))
4820 return TryCopyInitialization(S, From->getInit(0), ToType,
4821 SuppressUserConversions,
4822 InOverloadResolution,
4823 AllowObjCWritebackConversion);
4824 }
4825 // FIXME: Check the other conditions here: array of character type,
4826 // initializer is a string literal.
4827 if (ToType->isArrayType()) {
4828 InitializedEntity Entity =
4829 InitializedEntity::InitializeParameter(S.Context, ToType,
4830 /*Consumed=*/false);
4831 if (S.CanPerformCopyInitialization(Entity, From)) {
4832 Result.setStandard();
4833 Result.Standard.setAsIdentityConversion();
4834 Result.Standard.setFromType(ToType);
4835 Result.Standard.setAllToTypes(ToType);
4836 return Result;
4837 }
4838 }
4839 }
4840
4841 // C++14 [over.ics.list]p2: Otherwise, if the parameter type [...] (below).
4842 // C++11 [over.ics.list]p2:
4843 // If the parameter type is std::initializer_list<X> or "array of X" and
4844 // all the elements can be implicitly converted to X, the implicit
4845 // conversion sequence is the worst conversion necessary to convert an
4846 // element of the list to X.
4847 //
4848 // C++14 [over.ics.list]p3:
4849 // Otherwise, if the parameter type is "array of N X", if the initializer
4850 // list has exactly N elements or if it has fewer than N elements and X is
4851 // default-constructible, and if all the elements of the initializer list
4852 // can be implicitly converted to X, the implicit conversion sequence is
4853 // the worst conversion necessary to convert an element of the list to X.
4854 //
4855 // FIXME: We're missing a lot of these checks.
4856 bool toStdInitializerList = false;
4857 QualType X;
4858 if (ToType->isArrayType())
4859 X = S.Context.getAsArrayType(ToType)->getElementType();
4860 else
4861 toStdInitializerList = S.isStdInitializerList(ToType, &X);
4862 if (!X.isNull()) {
4863 for (unsigned i = 0, e = From->getNumInits(); i < e; ++i) {
4864 Expr *Init = From->getInit(i);
4865 ImplicitConversionSequence ICS =
4866 TryCopyInitialization(S, Init, X, SuppressUserConversions,
4867 InOverloadResolution,
4868 AllowObjCWritebackConversion);
4869 // If a single element isn't convertible, fail.
4870 if (ICS.isBad()) {
4871 Result = ICS;
4872 break;
4873 }
4874 // Otherwise, look for the worst conversion.
4875 if (Result.isBad() || CompareImplicitConversionSequences(
4876 S, From->getBeginLoc(), ICS, Result) ==
4877 ImplicitConversionSequence::Worse)
4878 Result = ICS;
4879 }
4880
4881 // For an empty list, we won't have computed any conversion sequence.
4882 // Introduce the identity conversion sequence.
4883 if (From->getNumInits() == 0) {
4884 Result.setStandard();
4885 Result.Standard.setAsIdentityConversion();
4886 Result.Standard.setFromType(ToType);
4887 Result.Standard.setAllToTypes(ToType);
4888 }
4889
4890 Result.setStdInitializerListElement(toStdInitializerList);
4891 return Result;
4892 }
4893
4894 // C++14 [over.ics.list]p4:
4895 // C++11 [over.ics.list]p3:
4896 // Otherwise, if the parameter is a non-aggregate class X and overload
4897 // resolution chooses a single best constructor [...] the implicit
4898 // conversion sequence is a user-defined conversion sequence. If multiple
4899 // constructors are viable but none is better than the others, the
4900 // implicit conversion sequence is a user-defined conversion sequence.
4901 if (ToType->isRecordType() && !ToType->isAggregateType()) {
4902 // This function can deal with initializer lists.
4903 return TryUserDefinedConversion(S, From, ToType, SuppressUserConversions,
4904 /*AllowExplicit=*/false,
4905 InOverloadResolution, /*CStyle=*/false,
4906 AllowObjCWritebackConversion,
4907 /*AllowObjCConversionOnExplicit=*/false);
4908 }
4909
4910 // C++14 [over.ics.list]p5:
4911 // C++11 [over.ics.list]p4:
4912 // Otherwise, if the parameter has an aggregate type which can be
4913 // initialized from the initializer list [...] the implicit conversion
4914 // sequence is a user-defined conversion sequence.
4915 if (ToType->isAggregateType()) {
4916 // Type is an aggregate, argument is an init list. At this point it comes
4917 // down to checking whether the initialization works.
4918 // FIXME: Find out whether this parameter is consumed or not.
4919 // FIXME: Expose SemaInit's aggregate initialization code so that we don't
4920 // need to call into the initialization code here; overload resolution
4921 // should not be doing that.
4922 InitializedEntity Entity =
4923 InitializedEntity::InitializeParameter(S.Context, ToType,
4924 /*Consumed=*/false);
4925 if (S.CanPerformCopyInitialization(Entity, From)) {
4926 Result.setUserDefined();
4927 Result.UserDefined.Before.setAsIdentityConversion();
4928 // Initializer lists don't have a type.
4929 Result.UserDefined.Before.setFromType(QualType());
4930 Result.UserDefined.Before.setAllToTypes(QualType());
4931
4932 Result.UserDefined.After.setAsIdentityConversion();
4933 Result.UserDefined.After.setFromType(ToType);
4934 Result.UserDefined.After.setAllToTypes(ToType);
4935 Result.UserDefined.ConversionFunction = nullptr;
4936 }
4937 return Result;
4938 }
4939
4940 // C++14 [over.ics.list]p6:
4941 // C++11 [over.ics.list]p5:
4942 // Otherwise, if the parameter is a reference, see 13.3.3.1.4.
4943 if (ToType->isReferenceType()) {
4944 // The standard is notoriously unclear here, since 13.3.3.1.4 doesn't
4945 // mention initializer lists in any way. So we go by what list-
4946 // initialization would do and try to extrapolate from that.
4947
4948 QualType T1 = ToType->getAs<ReferenceType>()->getPointeeType();
4949
4950 // If the initializer list has a single element that is reference-related
4951 // to the parameter type, we initialize the reference from that.
4952 if (From->getNumInits() == 1) {
4953 Expr *Init = From->getInit(0);
4954
4955 QualType T2 = Init->getType();
4956
4957 // If the initializer is the address of an overloaded function, try
4958 // to resolve the overloaded function. If all goes well, T2 is the
4959 // type of the resulting function.
4960 if (S.Context.getCanonicalType(T2) == S.Context.OverloadTy) {
4961 DeclAccessPair Found;
4962 if (FunctionDecl *Fn = S.ResolveAddressOfOverloadedFunction(
4963 Init, ToType, false, Found))
4964 T2 = Fn->getType();
4965 }
4966
4967 // Compute some basic properties of the types and the initializer.
4968 bool dummy1 = false;
4969 bool dummy2 = false;
4970 bool dummy3 = false;
4971 Sema::ReferenceCompareResult RefRelationship =
4972 S.CompareReferenceRelationship(From->getBeginLoc(), T1, T2, dummy1,
4973 dummy2, dummy3);
4974
4975 if (RefRelationship >= Sema::Ref_Related) {
4976 return TryReferenceInit(S, Init, ToType, /*FIXME*/ From->getBeginLoc(),
4977 SuppressUserConversions,
4978 /*AllowExplicit=*/false);
4979 }
4980 }
4981
4982 // Otherwise, we bind the reference to a temporary created from the
4983 // initializer list.
4984 Result = TryListConversion(S, From, T1, SuppressUserConversions,
4985 InOverloadResolution,
4986 AllowObjCWritebackConversion);
4987 if (Result.isFailure())
4988 return Result;
4989 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-9~svn360825/tools/clang/lib/Sema/SemaOverload.cpp"
, 4990, __PRETTY_FUNCTION__))
4990 "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-9~svn360825/tools/clang/lib/Sema/SemaOverload.cpp"
, 4990, __PRETTY_FUNCTION__))
;
4991
4992 // Can we even bind to a temporary?
4993 if (ToType->isRValueReferenceType() ||
4994 (T1.isConstQualified() && !T1.isVolatileQualified())) {
4995 StandardConversionSequence &SCS = Result.isStandard() ? Result.Standard :
4996 Result.UserDefined.After;
4997 SCS.ReferenceBinding = true;
4998 SCS.IsLvalueReference = ToType->isLValueReferenceType();
4999 SCS.BindsToRvalue = true;
5000 SCS.BindsToFunctionLvalue = false;
5001 SCS.BindsImplicitObjectArgumentWithoutRefQualifier = false;
5002 SCS.ObjCLifetimeConversionBinding = false;
5003 } else
5004 Result.setBad(BadConversionSequence::lvalue_ref_to_rvalue,
5005 From, ToType);
5006 return Result;
5007 }
5008
5009 // C++14 [over.ics.list]p7:
5010 // C++11 [over.ics.list]p6:
5011 // Otherwise, if the parameter type is not a class:
5012 if (!ToType->isRecordType()) {
5013 // - if the initializer list has one element that is not itself an
5014 // initializer list, the implicit conversion sequence is the one
5015 // required to convert the element to the parameter type.
5016 unsigned NumInits = From->getNumInits();
5017 if (NumInits == 1 && !isa<InitListExpr>(From->getInit(0)))
5018 Result = TryCopyInitialization(S, From->getInit(0), ToType,
5019 SuppressUserConversions,
5020 InOverloadResolution,
5021 AllowObjCWritebackConversion);
5022 // - if the initializer list has no elements, the implicit conversion
5023 // sequence is the identity conversion.
5024 else if (NumInits == 0) {
5025 Result.setStandard();
5026 Result.Standard.setAsIdentityConversion();
5027 Result.Standard.setFromType(ToType);
5028 Result.Standard.setAllToTypes(ToType);
5029 }
5030 return Result;
5031 }
5032
5033 // C++14 [over.ics.list]p8:
5034 // C++11 [over.ics.list]p7:
5035 // In all cases other than those enumerated above, no conversion is possible
5036 return Result;
5037}
5038
5039/// TryCopyInitialization - Try to copy-initialize a value of type
5040/// ToType from the expression From. Return the implicit conversion
5041/// sequence required to pass this argument, which may be a bad
5042/// conversion sequence (meaning that the argument cannot be passed to
5043/// a parameter of this type). If @p SuppressUserConversions, then we
5044/// do not permit any user-defined conversion sequences.
5045static ImplicitConversionSequence
5046TryCopyInitialization(Sema &S, Expr *From, QualType ToType,
5047 bool SuppressUserConversions,
5048 bool InOverloadResolution,
5049 bool AllowObjCWritebackConversion,
5050 bool AllowExplicit) {
5051 if (InitListExpr *FromInitList = dyn_cast<InitListExpr>(From))
5052 return TryListConversion(S, FromInitList, ToType, SuppressUserConversions,
5053 InOverloadResolution,AllowObjCWritebackConversion);
5054
5055 if (ToType->isReferenceType())
5056 return TryReferenceInit(S, From, ToType,
5057 /*FIXME:*/ From->getBeginLoc(),
5058 SuppressUserConversions, AllowExplicit);
5059
5060 return TryImplicitConversion(S, From, ToType,
5061 SuppressUserConversions,
5062 /*AllowExplicit=*/false,
5063 InOverloadResolution,
5064 /*CStyle=*/false,
5065 AllowObjCWritebackConversion,
5066 /*AllowObjCConversionOnExplicit=*/false);
5067}
5068
5069static bool TryCopyInitialization(const CanQualType FromQTy,
5070 const CanQualType ToQTy,
5071 Sema &S,
5072 SourceLocation Loc,
5073 ExprValueKind FromVK) {
5074 OpaqueValueExpr TmpExpr(Loc, FromQTy, FromVK);
5075 ImplicitConversionSequence ICS =
5076 TryCopyInitialization(S, &TmpExpr, ToQTy, true, true, false);
5077
5078 return !ICS.isBad();
5079}
5080
5081/// TryObjectArgumentInitialization - Try to initialize the object
5082/// parameter of the given member function (@c Method) from the
5083/// expression @p From.
5084static ImplicitConversionSequence
5085TryObjectArgumentInitialization(Sema &S, SourceLocation Loc, QualType FromType,
5086 Expr::Classification FromClassification,
5087 CXXMethodDecl *Method,
5088 CXXRecordDecl *ActingContext) {
5089 QualType ClassType = S.Context.getTypeDeclType(ActingContext);
5090 // [class.dtor]p2: A destructor can be invoked for a const, volatile or
5091 // const volatile object.
5092 Qualifiers Quals;
5093 if (isa<CXXDestructorDecl>(Method)) {
5094 Quals.addConst();
5095 Quals.addVolatile();
5096 } else {
5097 Quals = Method->getMethodQualifiers();
5098 }
5099
5100 QualType ImplicitParamType = S.Context.getQualifiedType(ClassType, Quals);
5101
5102 // Set up the conversion sequence as a "bad" conversion, to allow us
5103 // to exit early.
5104 ImplicitConversionSequence ICS;
5105
5106 // We need to have an object of class type.
5107 if (const PointerType *PT = FromType->getAs<PointerType>()) {
5108 FromType = PT->getPointeeType();
5109
5110 // When we had a pointer, it's implicitly dereferenced, so we
5111 // better have an lvalue.
5112 assert(FromClassification.isLValue())((FromClassification.isLValue()) ? static_cast<void> (0
) : __assert_fail ("FromClassification.isLValue()", "/build/llvm-toolchain-snapshot-9~svn360825/tools/clang/lib/Sema/SemaOverload.cpp"
, 5112, __PRETTY_FUNCTION__))
;
5113 }
5114
5115 assert(FromType->isRecordType())((FromType->isRecordType()) ? static_cast<void> (0) :
__assert_fail ("FromType->isRecordType()", "/build/llvm-toolchain-snapshot-9~svn360825/tools/clang/lib/Sema/SemaOverload.cpp"
, 5115, __PRETTY_FUNCTION__))
;
5116
5117 // C++0x [over.match.funcs]p4:
5118 // For non-static member functions, the type of the implicit object
5119 // parameter is
5120 //
5121 // - "lvalue reference to cv X" for functions declared without a
5122 // ref-qualifier or with the & ref-qualifier
5123 // - "rvalue reference to cv X" for functions declared with the &&
5124 // ref-qualifier
5125 //
5126 // where X is the class of which the function is a member and cv is the
5127 // cv-qualification on the member function declaration.
5128 //
5129 // However, when finding an implicit conversion sequence for the argument, we
5130 // are not allowed to perform user-defined conversions
5131 // (C++ [over.match.funcs]p5). We perform a simplified version of
5132 // reference binding here, that allows class rvalues to bind to
5133 // non-constant references.
5134
5135 // First check the qualifiers.
5136 QualType FromTypeCanon = S.Context.getCanonicalType(FromType);
5137 if (ImplicitParamType.getCVRQualifiers()
5138 != FromTypeCanon.getLocalCVRQualifiers() &&
5139 !ImplicitParamType.isAtLeastAsQualifiedAs(FromTypeCanon)) {
5140 ICS.setBad(BadConversionSequence::bad_qualifiers,
5141 FromType, ImplicitParamType);
5142 return ICS;
5143 }
5144
5145 if (FromTypeCanon.getQualifiers().hasAddressSpace()) {
5146 Qualifiers QualsImplicitParamType = ImplicitParamType.getQualifiers();
5147 Qualifiers QualsFromType = FromTypeCanon.getQualifiers();
5148 if (!QualsImplicitParamType.isAddressSpaceSupersetOf(QualsFromType)) {
5149 ICS.setBad(BadConversionSequence::bad_qualifiers,
5150 FromType, ImplicitParamType);
5151 return ICS;
5152 }
5153 }
5154
5155 // Check that we have either the same type or a derived type. It
5156 // affects the conversion rank.
5157 QualType ClassTypeCanon = S.Context.getCanonicalType(ClassType);
5158 ImplicitConversionKind SecondKind;
5159 if (ClassTypeCanon == FromTypeCanon.getLocalUnqualifiedType()) {
5160 SecondKind = ICK_Identity;
5161 } else if (S.IsDerivedFrom(Loc, FromType, ClassType))
5162 SecondKind = ICK_Derived_To_Base;
5163 else {
5164 ICS.setBad(BadConversionSequence::unrelated_class,
5165 FromType, ImplicitParamType);
5166 return ICS;
5167 }
5168
5169 // Check the ref-qualifier.
5170 switch (Method->getRefQualifier()) {
5171 case RQ_None:
5172 // Do nothing; we don't care about lvalueness or rvalueness.
5173 break;
5174
5175 case RQ_LValue:
5176 if (!FromClassification.isLValue() && !Quals.hasOnlyConst()) {
5177 // non-const lvalue reference cannot bind to an rvalue
5178 ICS.setBad(BadConversionSequence::lvalue_ref_to_rvalue, FromType,
5179 ImplicitParamType);
5180 return ICS;
5181 }
5182 break;
5183
5184 case RQ_RValue:
5185 if (!FromClassification.isRValue()) {
5186 // rvalue reference cannot bind to an lvalue
5187 ICS.setBad(BadConversionSequence::rvalue_ref_to_lvalue, FromType,
5188 ImplicitParamType);
5189 return ICS;
5190 }
5191 break;
5192 }
5193
5194 // Success. Mark this as a reference binding.
5195 ICS.setStandard();
5196 ICS.Standard.setAsIdentityConversion();
5197 ICS.Standard.Second = SecondKind;
5198 ICS.Standard.setFromType(FromType);
5199 ICS.Standard.setAllToTypes(ImplicitParamType);
5200 ICS.Standard.ReferenceBinding = true;
5201 ICS.Standard.DirectBinding = true;
5202 ICS.Standard.IsLvalueReference = Method->getRefQualifier() != RQ_RValue;
5203 ICS.Standard.BindsToFunctionLvalue = false;
5204 ICS.Standard.BindsToRvalue = FromClassification.isRValue();
5205 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier
5206 = (Method->getRefQualifier() == RQ_None);
5207 return ICS;
5208}
5209
5210/// PerformObjectArgumentInitialization - Perform initialization of
5211/// the implicit object parameter for the given Method with the given
5212/// expression.
5213ExprResult
5214Sema::PerformObjectArgumentInitialization(Expr *From,
5215 NestedNameSpecifier *Qualifier,
5216 NamedDecl *FoundDecl,
5217 CXXMethodDecl *Method) {
5218 QualType FromRecordType, DestType;
5219 QualType ImplicitParamRecordType =
5220 Method->getThisType()->getAs<PointerType>()->getPointeeType();
5221
5222 Expr::Classification FromClassification;
5223 if (const PointerType *PT = From->getType()->getAs<PointerType>()) {
5224 FromRecordType = PT->getPointeeType();
5225 DestType = Method->getThisType();
5226 FromClassification = Expr::Classification::makeSimpleLValue();
5227 } else {
5228 FromRecordType = From->getType();
5229 DestType = ImplicitParamRecordType;
5230 FromClassification = From->Classify(Context);
5231
5232 // When performing member access on an rvalue, materialize a temporary.
5233 if (From->isRValue()) {
5234 From = CreateMaterializeTemporaryExpr(FromRecordType, From,
5235 Method->getRefQualifier() !=
5236 RefQualifierKind::RQ_RValue);
5237 }
5238 }
5239
5240 // Note that we always use the true parent context when performing
5241 // the actual argument initialization.
5242 ImplicitConversionSequence ICS = TryObjectArgumentInitialization(
5243 *this, From->getBeginLoc(), From->getType(), FromClassification, Method,
5244 Method->getParent());
5245 if (ICS.isBad()) {
5246 switch (ICS.Bad.Kind) {
5247 case BadConversionSequence::bad_qualifiers: {
5248 Qualifiers FromQs = FromRecordType.getQualifiers();
5249 Qualifiers ToQs = DestType.getQualifiers();
5250 unsigned CVR = FromQs.getCVRQualifiers() & ~ToQs.getCVRQualifiers();
5251 if (CVR) {
5252 Diag(From->getBeginLoc(), diag::err_member_function_call_bad_cvr)
5253 << Method->getDeclName() << FromRecordType << (CVR - 1)
5254 << From->getSourceRange();
5255 Diag(Method->getLocation(), diag::note_previous_decl)
5256 << Method->getDeclName();
5257 return ExprError();
5258 }
5259 break;
5260 }
5261
5262 case BadConversionSequence::lvalue_ref_to_rvalue:
5263 case BadConversionSequence::rvalue_ref_to_lvalue: {
5264 bool IsRValueQualified =
5265 Method->getRefQualifier() == RefQualifierKind::RQ_RValue;
5266 Diag(From->getBeginLoc(), diag::err_member_function_call_bad_ref)
5267 << Method->getDeclName() << FromClassification.isRValue()
5268 << IsRValueQualified;
5269 Diag(Method->getLocation(), diag::note_previous_decl)
5270 << Method->getDeclName();
5271 return ExprError();
5272 }
5273
5274 case BadConversionSequence::no_conversion:
5275 case BadConversionSequence::unrelated_class:
5276 break;
5277 }
5278
5279 return Diag(From->getBeginLoc(), diag::err_member_function_call_bad_type)
5280 << ImplicitParamRecordType << FromRecordType
5281 << From->getSourceRange();
5282 }
5283
5284 if (ICS.Standard.Second == ICK_Derived_To_Base) {
5285 ExprResult FromRes =
5286 PerformObjectMemberConversion(From, Qualifier, FoundDecl, Method);
5287 if (FromRes.isInvalid())
5288 return ExprError();
5289 From = FromRes.get();
5290 }
5291
5292 if (!Context.hasSameType(From->getType(), DestType)) {
5293 CastKind CK;
5294 if (FromRecordType.getAddressSpace() != DestType.getAddressSpace())
5295 CK = CK_AddressSpaceConversion;
5296 else
5297 CK = CK_NoOp;
5298 From = ImpCastExprToType(From, DestType, CK, From->getValueKind()).get();
5299 }
5300 return From;
5301}
5302
5303/// TryContextuallyConvertToBool - Attempt to contextually convert the
5304/// expression From to bool (C++0x [conv]p3).
5305static ImplicitConversionSequence
5306TryContextuallyConvertToBool(Sema &S, Expr *From) {
5307 return TryImplicitConversion(S, From, S.Context.BoolTy,
5308 /*SuppressUserConversions=*/false,
5309 /*AllowExplicit=*/true,
5310 /*InOverloadResolution=*/false,
5311 /*CStyle=*/false,
5312 /*AllowObjCWritebackConversion=*/false,
5313 /*AllowObjCConversionOnExplicit=*/false);
5314}
5315
5316/// PerformContextuallyConvertToBool - Perform a contextual conversion
5317/// of the expression From to bool (C++0x [conv]p3).
5318ExprResult Sema::PerformContextuallyConvertToBool(Expr *From) {
5319 if (checkPlaceholderForOverload(*this, From))
5320 return ExprError();
5321
5322 ImplicitConversionSequence ICS = TryContextuallyConvertToBool(*this, From);
5323 if (!ICS.isBad())
5324 return PerformImplicitConversion(From, Context.BoolTy, ICS, AA_Converting);
5325
5326 if (!DiagnoseMultipleUserDefinedConversion(From, Context.BoolTy))
5327 return Diag(From->getBeginLoc(), diag::err_typecheck_bool_condition)
5328 << From->getType() << From->getSourceRange();
5329 return ExprError();
5330}
5331
5332/// Check that the specified conversion is permitted in a converted constant
5333/// expression, according to C++11 [expr.const]p3. Return true if the conversion
5334/// is acceptable.
5335static bool CheckConvertedConstantConversions(Sema &S,
5336 StandardConversionSequence &SCS) {
5337 // Since we know that the target type is an integral or unscoped enumeration
5338 // type, most conversion kinds are impossible. All possible First and Third
5339 // conversions are fine.
5340 switch (SCS.Second) {
5341 case ICK_Identity:
5342 case ICK_Function_Conversion:
5343 case ICK_Integral_Promotion:
5344 case ICK_Integral_Conversion: // Narrowing conversions are checked elsewhere.
5345 case ICK_Zero_Queue_Conversion:
5346 return true;
5347
5348 case ICK_Boolean_Conversion:
5349 // Conversion from an integral or unscoped enumeration type to bool is
5350 // classified as ICK_Boolean_Conversion, but it's also arguably an integral
5351 // conversion, so we allow it in a converted constant expression.
5352 //
5353 // FIXME: Per core issue 1407, we should not allow this, but that breaks
5354 // a lot of popular code. We should at least add a warning for this
5355 // (non-conforming) extension.
5356 return SCS.getFromType()->isIntegralOrUnscopedEnumerationType() &&
5357 SCS.getToType(2)->isBooleanType();
5358
5359 case ICK_Pointer_Conversion:
5360 case ICK_Pointer_Member:
5361 // C++1z: null pointer conversions and null member pointer conversions are
5362 // only permitted if the source type is std::nullptr_t.
5363 return SCS.getFromType()->isNullPtrType();
5364
5365 case ICK_Floating_Promotion:
5366 case ICK_Complex_Promotion:
5367 case ICK_Floating_Conversion:
5368 case ICK_Complex_Conversion:
5369 case ICK_Floating_Integral:
5370 case ICK_Compatible_Conversion:
5371 case ICK_Derived_To_Base:
5372 case ICK_Vector_Conversion:
5373 case ICK_Vector_Splat:
5374 case ICK_Complex_Real:
5375 case ICK_Block_Pointer_Conversion:
5376 case ICK_TransparentUnionConversion:
5377 case ICK_Writeback_Conversion:
5378 case ICK_Zero_Event_Conversion:
5379 case ICK_C_Only_Conversion:
5380 case ICK_Incompatible_Pointer_Conversion:
5381 return false;
5382
5383 case ICK_Lvalue_To_Rvalue:
5384 case ICK_Array_To_Pointer:
5385 case ICK_Function_To_Pointer:
5386 llvm_unreachable("found a first conversion kind in Second")::llvm::llvm_unreachable_internal("found a first conversion kind in Second"
, "/build/llvm-toolchain-snapshot-9~svn360825/tools/clang/lib/Sema/SemaOverload.cpp"
, 5386)
;
5387
5388 case ICK_Qualification:
5389 llvm_unreachable("found a third conversion kind in Second")::llvm::llvm_unreachable_internal("found a third conversion kind in Second"
, "/build/llvm-toolchain-snapshot-9~svn360825/tools/clang/lib/Sema/SemaOverload.cpp"
, 5389)
;
5390
5391 case ICK_Num_Conversion_Kinds:
5392 break;
5393 }
5394
5395 llvm_unreachable("unknown conversion kind")::llvm::llvm_unreachable_internal("unknown conversion kind", "/build/llvm-toolchain-snapshot-9~svn360825/tools/clang/lib/Sema/SemaOverload.cpp"
, 5395)
;
5396}
5397
5398/// CheckConvertedConstantExpression - Check that the expression From is a
5399/// converted constant expression of type T, perform the conversion and produce
5400/// the converted expression, per C++11 [expr.const]p3.
5401static ExprResult CheckConvertedConstantExpression(Sema &S, Expr *From,
5402 QualType T, APValue &Value,
5403 Sema::CCEKind CCE,
5404 bool RequireInt) {
5405 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-9~svn360825/tools/clang/lib/Sema/SemaOverload.cpp"
, 5406, __PRETTY_FUNCTION__))
5406 "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-9~svn360825/tools/clang/lib/Sema/SemaOverload.cpp"
, 5406, __PRETTY_FUNCTION__))
;
5407
5408 if (checkPlaceholderForOverload(S, From))
5409 return ExprError();
5410
5411 // C++1z [expr.const]p3:
5412 // A converted constant expression of type T is an expression,
5413 // implicitly converted to type T, where the converted
5414 // expression is a constant expression and the implicit conversion
5415 // sequence contains only [... list of conversions ...].
5416 // C++1z [stmt.if]p2:
5417 // If the if statement is of the form if constexpr, the value of the
5418 // condition shall be a contextually converted constant expression of type
5419 // bool.
5420 ImplicitConversionSequence ICS =
5421 CCE == Sema::CCEK_ConstexprIf || CCE == Sema::CCEK_ExplicitBool
5422 ? TryContextuallyConvertToBool(S, From)
5423 : TryCopyInitialization(S, From, T,
5424 /*SuppressUserConversions=*/false,
5425 /*InOverloadResolution=*/false,
5426 /*AllowObjcWritebackConversion=*/false,
5427 /*AllowExplicit=*/false);
5428 StandardConversionSequence *SCS = nullptr;
5429 switch (ICS.getKind()) {
5430 case ImplicitConversionSequence::StandardConversion:
5431 SCS = &ICS.Standard;
5432 break;
5433 case ImplicitConversionSequence::UserDefinedConversion:
5434 // We are converting to a non-class type, so the Before sequence
5435 // must be trivial.
5436 SCS = &ICS.UserDefined.After;
5437 break;
5438 case ImplicitConversionSequence::AmbiguousConversion:
5439 case ImplicitConversionSequence::BadConversion:
5440 if (!S.DiagnoseMultipleUserDefinedConversion(From, T))
5441 return S.Diag(From->getBeginLoc(),
5442 diag::err_typecheck_converted_constant_expression)
5443 << From->getType() << From->getSourceRange() << T;
5444 return ExprError();
5445
5446 case ImplicitConversionSequence::EllipsisConversion:
5447 llvm_unreachable("ellipsis conversion in converted constant expression")::llvm::llvm_unreachable_internal("ellipsis conversion in converted constant expression"
, "/build/llvm-toolchain-snapshot-9~svn360825/tools/clang/lib/Sema/SemaOverload.cpp"
, 5447)
;
5448 }
5449
5450 // Check that we would only use permitted conversions.
5451 if (!CheckConvertedConstantConversions(S, *SCS)) {
5452 return S.Diag(From->getBeginLoc(),
5453 diag::err_typecheck_converted_constant_expression_disallowed)
5454 << From->getType() << From->getSourceRange() << T;
5455 }
5456 // [...] and where the reference binding (if any) binds directly.
5457 if (SCS->ReferenceBinding && !SCS->DirectBinding) {
5458 return S.Diag(From->getBeginLoc(),
5459 diag::err_typecheck_converted_constant_expression_indirect)
5460 << From->getType() << From->getSourceRange() << T;
5461 }
5462
5463 ExprResult Result =
5464 S.PerformImplicitConversion(From, T, ICS, Sema::AA_Converting);
5465 if (Result.isInvalid())
5466 return Result;
5467
5468 // Check for a narrowing implicit conversion.
5469 APValue PreNarrowingValue;
5470 QualType PreNarrowingType;
5471 switch (SCS->getNarrowingKind(S.Context, Result.get(), PreNarrowingValue,
5472 PreNarrowingType)) {
5473 case NK_Dependent_Narrowing:
5474 // Implicit conversion to a narrower type, but the expression is
5475 // value-dependent so we can't tell whether it's actually narrowing.
5476 case NK_Variable_Narrowing:
5477 // Implicit conversion to a narrower type, and the value is not a constant
5478 // expression. We'll diagnose this in a moment.
5479 case NK_Not_Narrowing:
5480 break;
5481
5482 case NK_Constant_Narrowing:
5483 S.Diag(From->getBeginLoc(), diag::ext_cce_narrowing)
5484 << CCE << /*Constant*/ 1
5485 << PreNarrowingValue.getAsString(S.Context, PreNarrowingType) << T;
5486 break;
5487
5488 case NK_Type_Narrowing:
5489 S.Diag(From->getBeginLoc(), diag::ext_cce_narrowing)
5490 << CCE << /*Constant*/ 0 << From->getType() << T;
5491 break;
5492 }
5493
5494 if (Result.get()->isValueDependent()) {
5495 Value = APValue();
5496 return Result;
5497 }
5498
5499 // Check the expression is a constant expression.
5500 SmallVector<PartialDiagnosticAt, 8> Notes;
5501 Expr::EvalResult Eval;
5502 Eval.Diag = &Notes;
5503 Expr::ConstExprUsage Usage = CCE == Sema::CCEK_TemplateArg
5504 ? Expr::EvaluateForMangling
5505 : Expr::EvaluateForCodeGen;
5506
5507 if (!Result.get()->EvaluateAsConstantExpr(Eval, Usage, S.Context) ||
5508 (RequireInt && !Eval.Val.isInt())) {
5509 // The expression can't be folded, so we can't keep it at this position in
5510 // the AST.
5511 Result = ExprError();
5512 } else {
5513 Value = Eval.Val;
5514
5515 if (Notes.empty()) {
5516 // It's a constant expression.
5517 return ConstantExpr::Create(S.Context, Result.get());
5518 }
5519 }
5520
5521 // It's not a constant expression. Produce an appropriate diagnostic.
5522 if (Notes.size() == 1 &&
5523 Notes[0].second.getDiagID() == diag::note_invalid_subexpr_in_const_expr)
5524 S.Diag(Notes[0].first, diag::err_expr_not_cce) << CCE;
5525 else {
5526 S.Diag(From->getBeginLoc(), diag::err_expr_not_cce)
5527 << CCE << From->getSourceRange();
5528 for (unsigned I = 0; I < Notes.size(); ++I)
5529 S.Diag(Notes[I].first, Notes[I].second);
5530 }
5531 return ExprError();
5532}
5533
5534ExprResult Sema::CheckConvertedConstantExpression(Expr *From, QualType T,
5535 APValue &Value, CCEKind CCE) {
5536 return ::CheckConvertedConstantExpression(*this, From, T, Value, CCE, false);
5537}
5538
5539ExprResult Sema::CheckConvertedConstantExpression(Expr *From, QualType T,
5540 llvm::APSInt &Value,
5541 CCEKind CCE) {
5542 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-9~svn360825/tools/clang/lib/Sema/SemaOverload.cpp"
, 5542, __PRETTY_FUNCTION__))
;
5543
5544 APValue V;
5545 auto R = ::CheckConvertedConstantExpression(*this, From, T, V, CCE, true);
5546 if (!R.isInvalid() && !R.get()->isValueDependent())
5547 Value = V.getInt();
5548 return R;
5549}
5550
5551
5552/// dropPointerConversions - If the given standard conversion sequence
5553/// involves any pointer conversions, remove them. This may change
5554/// the result type of the conversion sequence.
5555static void dropPointerConversion(StandardConversionSequence &SCS) {
5556 if (SCS.Second == ICK_Pointer_Conversion) {
5557 SCS.Second = ICK_Identity;
5558 SCS.Third = ICK_Identity;
5559 SCS.ToTypePtrs[2] = SCS.ToTypePtrs[1] = SCS.ToTypePtrs[0];
5560 }
5561}
5562
5563/// TryContextuallyConvertToObjCPointer - Attempt to contextually
5564/// convert the expression From to an Objective-C pointer type.
5565static ImplicitConversionSequence
5566TryContextuallyConvertToObjCPointer(Sema &S, Expr *From) {
5567 // Do an implicit conversion to 'id'.
5568 QualType Ty = S.Context.getObjCIdType();
5569 ImplicitConversionSequence ICS
5570 = TryImplicitConversion(S, From, Ty,
5571 // FIXME: Are these flags correct?
5572 /*SuppressUserConversions=*/false,
5573 /*AllowExplicit=*/true,
5574 /*InOverloadResolution=*/false,
5575 /*CStyle=*/false,
5576 /*AllowObjCWritebackConversion=*/false,
5577 /*AllowObjCConversionOnExplicit=*/true);
5578
5579 // Strip off any final conversions to 'id'.
5580 switch (ICS.getKind()) {
5581 case ImplicitConversionSequence::BadConversion:
5582 case ImplicitConversionSequence::AmbiguousConversion:
5583 case ImplicitConversionSequence::EllipsisConversion:
5584 break;
5585
5586 case ImplicitConversionSequence::UserDefinedConversion:
5587 dropPointerConversion(ICS.UserDefined.After);
5588 break;
5589
5590 case ImplicitConversionSequence::StandardConversion:
5591 dropPointerConversion(ICS.Standard);
5592 break;
5593 }
5594
5595 return ICS;
5596}
5597
5598/// PerformContextuallyConvertToObjCPointer - Perform a contextual
5599/// conversion of the expression From to an Objective-C pointer type.
5600/// Returns a valid but null ExprResult if no conversion sequence exists.
5601ExprResult Sema::PerformContextuallyConvertToObjCPointer(Expr *From) {
5602 if (checkPlaceholderForOverload(*this, From))
5603 return ExprError();
5604
5605 QualType Ty = Context.getObjCIdType();
5606 ImplicitConversionSequence ICS =
5607 TryContextuallyConvertToObjCPointer(*this, From);
5608 if (!ICS.isBad())
5609 return PerformImplicitConversion(From, Ty, ICS, AA_Converting);
5610 return ExprResult();
5611}
5612
5613/// Determine whether the provided type is an integral type, or an enumeration
5614/// type of a permitted flavor.
5615bool Sema::ICEConvertDiagnoser::match(QualType T) {
5616 return AllowScopedEnumerations ? T->isIntegralOrEnumerationType()
5617 : T->isIntegralOrUnscopedEnumerationType();
5618}
5619
5620static ExprResult
5621diagnoseAmbiguousConversion(Sema &SemaRef, SourceLocation Loc, Expr *From,
5622 Sema::ContextualImplicitConverter &Converter,
5623 QualType T, UnresolvedSetImpl &ViableConversions) {
5624
5625 if (Converter.Suppress)
5626 return ExprError();
5627
5628 Converter.diagnoseAmbiguous(SemaRef, Loc, T) << From->getSourceRange();
5629 for (unsigned I = 0, N = ViableConversions.size(); I != N; ++I) {
5630 CXXConversionDecl *Conv =
5631 cast<CXXConversionDecl>(ViableConversions[I]->getUnderlyingDecl());
5632 QualType ConvTy = Conv->getConversionType().getNonReferenceType();
5633 Converter.noteAmbiguous(SemaRef, Conv, ConvTy);
5634 }
5635 return From;
5636}
5637
5638static bool
5639diagnoseNoViableConversion(Sema &SemaRef, SourceLocation Loc, Expr *&From,
5640 Sema::ContextualImplicitConverter &Converter,
5641 QualType T, bool HadMultipleCandidates,
5642 UnresolvedSetImpl &ExplicitConversions) {
5643 if (ExplicitConversions.size() == 1 && !Converter.Suppress) {
5644 DeclAccessPair Found = ExplicitConversions[0];
5645 CXXConversionDecl *Conversion =
5646 cast<CXXConversionDecl>(Found->getUnderlyingDecl());
5647
5648 // The user probably meant to invoke the given explicit
5649 // conversion; use it.
5650 QualType ConvTy = Conversion->getConversionType().getNonReferenceType();
5651 std::string TypeStr;
5652 ConvTy.getAsStringInternal(TypeStr, SemaRef.getPrintingPolicy());
5653
5654 Converter.diagnoseExplicitConv(SemaRef, Loc, T, ConvTy)
5655 << FixItHint::CreateInsertion(From->getBeginLoc(),
5656 "static_cast<" + TypeStr + ">(")
5657 << FixItHint::CreateInsertion(
5658 SemaRef.getLocForEndOfToken(From->getEndLoc()), ")");
5659 Converter.noteExplicitConv(SemaRef, Conversion, ConvTy);
5660
5661 // If we aren't in a SFINAE context, build a call to the
5662 // explicit conversion function.
5663 if (SemaRef.isSFINAEContext())
5664 return true;
5665
5666 SemaRef.CheckMemberOperatorAccess(From->getExprLoc(), From, nullptr, Found);
5667 ExprResult Result = SemaRef.BuildCXXMemberCallExpr(From, Found, Conversion,
5668 HadMultipleCandidates);
5669 if (Result.isInvalid())
5670 return true;
5671 // Record usage of conversion in an implicit cast.
5672 From = ImplicitCastExpr::Create(SemaRef.Context, Result.get()->getType(),
5673 CK_UserDefinedConversion, Result.get(),
5674 nullptr, Result.get()->getValueKind());
5675 }
5676 return false;
5677}
5678
5679static bool recordConversion(Sema &SemaRef, SourceLocation Loc, Expr *&From,
5680 Sema::ContextualImplicitConverter &Converter,
5681 QualType T, bool HadMultipleCandidates,
5682 DeclAccessPair &Found) {
5683 CXXConversionDecl *Conversion =
5684 cast<CXXConversionDecl>(Found->getUnderlyingDecl());
5685 SemaRef.CheckMemberOperatorAccess(From->getExprLoc(), From, nullptr, Found);
5686
5687 QualType ToType = Conversion->getConversionType().getNonReferenceType();
5688 if (!Converter.SuppressConversion) {
5689 if (SemaRef.isSFINAEContext())
5690 return true;
5691
5692 Converter.diagnoseConversion(SemaRef, Loc, T, ToType)
5693 << From->getSourceRange();
5694 }
5695
5696 ExprResult Result = SemaRef.BuildCXXMemberCallExpr(From, Found, Conversion,
5697 HadMultipleCandidates);
5698 if (Result.isInvalid())
5699 return true;
5700 // Record usage of conversion in an implicit cast.
5701 From = ImplicitCastExpr::Create(SemaRef.Context, Result.get()->getType(),
5702 CK_UserDefinedConversion, Result.get(),
5703 nullptr, Result.get()->getValueKind());
5704 return false;
5705}
5706
5707static ExprResult finishContextualImplicitConversion(
5708 Sema &SemaRef, SourceLocation Loc, Expr *From,
5709 Sema::ContextualImplicitConverter &Converter) {
5710 if (!Converter.match(From->getType()) && !Converter.Suppress)
5711 Converter.diagnoseNoMatch(SemaRef, Loc, From->getType())
5712 << From->getSourceRange();
5713
5714 return SemaRef.DefaultLvalueConversion(From);
5715}
5716
5717static void
5718collectViableConversionCandidates(Sema &SemaRef, Expr *From, QualType ToType,
5719 UnresolvedSetImpl &ViableConversions,
5720 OverloadCandidateSet &CandidateSet) {
5721 for (unsigned I = 0, N = ViableConversions.size(); I != N; ++I) {
5722 DeclAccessPair FoundDecl = ViableConversions[I];
5723 NamedDecl *D = FoundDecl.getDecl();
5724 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext());
5725 if (isa<UsingShadowDecl>(D))
5726 D = cast<UsingShadowDecl>(D)->getTargetDecl();
5727
5728 CXXConversionDecl *Conv;
5729 FunctionTemplateDecl *ConvTemplate;
5730 if ((ConvTemplate = dyn_cast<FunctionTemplateDecl>(D)))
5731 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl());
5732 else
5733 Conv = cast<CXXConversionDecl>(D);
5734
5735 if (ConvTemplate)
5736 SemaRef.AddTemplateConversionCandidate(
5737 ConvTemplate, FoundDecl, ActingContext, From, ToType, CandidateSet,
5738 /*AllowObjCConversionOnExplicit=*/false, /*AllowExplicit*/ true);
5739 else
5740 SemaRef.AddConversionCandidate(Conv, FoundDecl, ActingContext, From,
5741 ToType, CandidateSet,
5742 /*AllowObjCConversionOnExplicit=*/false,
5743 /*AllowExplicit*/ true);
5744 }
5745}
5746
5747/// Attempt to convert the given expression to a type which is accepted
5748/// by the given converter.
5749///
5750/// This routine will attempt to convert an expression of class type to a
5751/// type accepted by the specified converter. In C++11 and before, the class
5752/// must have a single non-explicit conversion function converting to a matching
5753/// type. In C++1y, there can be multiple such conversion functions, but only
5754/// one target type.
5755///
5756/// \param Loc The source location of the construct that requires the
5757/// conversion.
5758///
5759/// \param From The expression we're converting from.
5760///
5761/// \param Converter Used to control and diagnose the conversion process.
5762///
5763/// \returns The expression, converted to an integral or enumeration type if
5764/// successful.
5765ExprResult Sema::PerformContextualImplicitConversion(
5766 SourceLocation Loc, Expr *From, ContextualImplicitConverter &Converter) {
5767 // We can't perform any more checking for type-dependent expressions.
5768 if (From->isTypeDependent())
5769 return From;
5770
5771 // Process placeholders immediately.
5772 if (From->hasPlaceholderType()) {
5773 ExprResult result = CheckPlaceholderExpr(From);
5774 if (result.isInvalid())
5775 return result;
5776 From = result.get();
5777 }
5778
5779 // If the expression already has a matching type, we're golden.
5780 QualType T = From->getType();
5781 if (Converter.match(T))
5782 return DefaultLvalueConversion(From);
5783
5784 // FIXME: Check for missing '()' if T is a function type?
5785
5786 // We can only perform contextual implicit conversions on objects of class
5787 // type.
5788 const RecordType *RecordTy = T->getAs<RecordType>();
5789 if (!RecordTy || !getLangOpts().CPlusPlus) {
5790 if (!Converter.Suppress)
5791 Converter.diagnoseNoMatch(*this, Loc, T) << From->getSourceRange();
5792 return From;
5793 }
5794
5795 // We must have a complete class type.
5796 struct TypeDiagnoserPartialDiag : TypeDiagnoser {
5797 ContextualImplicitConverter &Converter;
5798 Expr *From;
5799
5800 TypeDiagnoserPartialDiag(ContextualImplicitConverter &Converter, Expr *From)
5801 : Converter(Converter), From(From) {}
5802
5803 void diagnose(Sema &S, SourceLocation Loc, QualType T) override {
5804 Converter.diagnoseIncomplete(S, Loc, T) << From->getSourceRange();
5805 }
5806 } IncompleteDiagnoser(Converter, From);
5807
5808 if (Converter.Suppress ? !isCompleteType(Loc, T)
5809 : RequireCompleteType(Loc, T, IncompleteDiagnoser))
5810 return From;
5811
5812 // Look for a conversion to an integral or enumeration type.
5813 UnresolvedSet<4>
5814 ViableConversions; // These are *potentially* viable in C++1y.
5815 UnresolvedSet<4> ExplicitConversions;
5816 const auto &Conversions =
5817 cast<CXXRecordDecl>(RecordTy->getDecl())->getVisibleConversionFunctions();
5818
5819 bool HadMultipleCandidates =
5820 (std::distance(Conversions.begin(), Conversions.end()) > 1);
5821
5822 // To check that there is only one target type, in C++1y:
5823 QualType ToType;
5824 bool HasUniqueTargetType = true;
5825
5826 // Collect explicit or viable (potentially in C++1y) conversions.
5827 for (auto I = Conversions.begin(), E = Conversions.end(); I != E; ++I) {
5828 NamedDecl *D = (*I)->getUnderlyingDecl();
5829 CXXConversionDecl *Conversion;
5830 FunctionTemplateDecl *ConvTemplate = dyn_cast<FunctionTemplateDecl>(D);
5831 if (ConvTemplate) {
5832 if (getLangOpts().CPlusPlus14)
5833 Conversion = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl());
5834 else
5835 continue; // C++11 does not consider conversion operator templates(?).
5836 } else
5837 Conversion = cast<CXXConversionDecl>(D);
5838
5839 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-9~svn360825/tools/clang/lib/Sema/SemaOverload.cpp"
, 5841, __PRETTY_FUNCTION__))
5840 "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-9~svn360825/tools/clang/lib/Sema/SemaOverload.cpp"
, 5841, __PRETTY_FUNCTION__))
5841 "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-9~svn360825/tools/clang/lib/Sema/SemaOverload.cpp"
, 5841, __PRETTY_FUNCTION__))
;
5842
5843 QualType CurToType = Conversion->getConversionType().getNonReferenceType();
5844 if (Converter.match(CurToType) || ConvTemplate) {
5845
5846 if (Conversion->isExplicit()) {
5847 // FIXME: For C++1y, do we need this restriction?
5848 // cf. diagnoseNoViableConversion()
5849 if (!ConvTemplate)
5850 ExplicitConversions.addDecl(I.getDecl(), I.getAccess());
5851 } else {
5852 if (!ConvTemplate && getLangOpts().CPlusPlus14) {
5853 if (ToType.isNull())
5854 ToType = CurToType.getUnqualifiedType();
5855 else if (HasUniqueTargetType &&
5856 (CurToType.getUnqualifiedType() != ToType))
5857 HasUniqueTargetType = false;
5858 }
5859 ViableConversions.addDecl(I.getDecl(), I.getAccess());
5860 }
5861 }
5862 }
5863
5864 if (getLangOpts().CPlusPlus14) {
5865 // C++1y [conv]p6:
5866 // ... An expression e of class type E appearing in such a context
5867 // is said to be contextually implicitly converted to a specified
5868 // type T and is well-formed if and only if e can be implicitly
5869 // converted to a type T that is determined as follows: E is searched
5870 // for conversion functions whose return type is cv T or reference to
5871 // cv T such that T is allowed by the context. There shall be
5872 // exactly one such T.
5873
5874 // If no unique T is found:
5875 if (ToType.isNull()) {
5876 if (diagnoseNoViableConversion(*this, Loc, From, Converter, T,
5877 HadMultipleCandidates,
5878 ExplicitConversions))
5879 return ExprError();
5880 return finishContextualImplicitConversion(*this, Loc, From, Converter);
5881 }
5882
5883 // If more than one unique Ts are found:
5884 if (!HasUniqueTargetType)
5885 return diagnoseAmbiguousConversion(*this, Loc, From, Converter, T,
5886 ViableConversions);
5887
5888 // If one unique T is found:
5889 // First, build a candidate set from the previously recorded
5890 // potentially viable conversions.
5891 OverloadCandidateSet CandidateSet(Loc, OverloadCandidateSet::CSK_Normal);
5892 collectViableConversionCandidates(*this, From, ToType, ViableConversions,
5893 CandidateSet);
5894
5895 // Then, perform overload resolution over the candidate set.
5896 OverloadCandidateSet::iterator Best;
5897 switch (CandidateSet.BestViableFunction(*this, Loc, Best)) {
5898 case OR_Success: {
5899 // Apply this conversion.
5900 DeclAccessPair Found =
5901 DeclAccessPair::make(Best->Function, Best->FoundDecl.getAccess());
5902 if (recordConversion(*this, Loc, From, Converter, T,
5903 HadMultipleCandidates, Found))
5904 return ExprError();
5905 break;
5906 }
5907 case OR_Ambiguous:
5908 return diagnoseAmbiguousConversion(*this, Loc, From, Converter, T,
5909 ViableConversions);
5910 case OR_No_Viable_Function:
5911 if (diagnoseNoViableConversion(*this, Loc, From, Converter, T,
5912 HadMultipleCandidates,
5913 ExplicitConversions))
5914 return ExprError();
5915 LLVM_FALLTHROUGH[[clang::fallthrough]];
5916 case OR_Deleted:
5917 // We'll complain below about a non-integral condition type.
5918 break;
5919 }
5920 } else {
5921 switch (ViableConversions.size()) {
5922 case 0: {
5923 if (diagnoseNoViableConversion(*this, Loc, From, Converter, T,
5924 HadMultipleCandidates,
5925 ExplicitConversions))
5926 return ExprError();
5927
5928 // We'll complain below about a non-integral condition type.
5929 break;
5930 }
5931 case 1: {
5932 // Apply this conversion.
5933 DeclAccessPair Found = ViableConversions[0];
5934 if (recordConversion(*this, Loc, From, Converter, T,
5935 HadMultipleCandidates, Found))
5936 return ExprError();
5937 break;
5938 }
5939 default:
5940 return diagnoseAmbiguousConversion(*this, Loc, From, Converter, T,
5941 ViableConversions);
5942 }
5943 }
5944
5945 return finishContextualImplicitConversion(*this, Loc, From, Converter);
5946}
5947
5948/// IsAcceptableNonMemberOperatorCandidate - Determine whether Fn is
5949