Bug Summary

File:clang/lib/Sema/SemaOverload.cpp
Warning:line 2807, column 30
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 -setup-static-analyzer -analyzer-config-compatibility-mode=true -mrelocation-model pic -pic-level 2 -mthread-model posix -mframe-pointer=none -relaxed-aliasing -fmath-errno -fno-rounding-math -masm-verbose -mconstructor-aliases -munwind-tables -fuse-init-array -target-cpu x86-64 -dwarf-column-info -debugger-tuning=gdb -ffunction-sections -fdata-sections -resource-dir /usr/lib/llvm-10/lib/clang/10.0.0 -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-10~+201911111502510600c19528f1809/build-llvm/tools/clang/lib/Sema -I /build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema -I /build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/include -I /build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/build-llvm/tools/clang/include -I /build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/build-llvm/include -I /build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/llvm/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/local/include -internal-isystem /usr/lib/llvm-10/lib/clang/10.0.0/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++14 -fdeprecated-macro -fdebug-compilation-dir /build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/build-llvm/tools/clang/lib/Sema -fdebug-prefix-map=/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809=. -ferror-limit 19 -fmessage-length 0 -fvisibility-inlines-hidden -stack-protector 2 -fgnuc-version=4.2.1 -fobjc-runtime=gcc -fno-common -fdiagnostics-show-option -vectorize-loops -vectorize-slp -analyzer-output=html -analyzer-config stable-report-filename=true -faddrsig -o /tmp/scan-build-2019-12-07-102640-14763-1 -x c++ /build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaOverload.cpp

/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaOverload.cpp

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(ASTContext &Ctx,
261 const Expr *Converted) {
262 // We can have cleanups wrapping the converted expression; these need to be
263 // preserved so that destructors run if necessary.
264 if (auto *EWC = dyn_cast<ExprWithCleanups>(Converted)) {
265 Expr *Inner =
266 const_cast<Expr *>(IgnoreNarrowingConversion(Ctx, EWC->getSubExpr()));
267 return ExprWithCleanups::Create(Ctx, Inner, EWC->cleanupsHaveSideEffects(),
268 EWC->getObjects());
269 }
270
271 while (auto *ICE = dyn_cast<ImplicitCastExpr>(Converted)) {
272 switch (ICE->getCastKind()) {
273 case CK_NoOp:
274 case CK_IntegralCast:
275 case CK_IntegralToBoolean:
276 case CK_IntegralToFloating:
277 case CK_BooleanToSignedIntegral:
278 case CK_FloatingToIntegral:
279 case CK_FloatingToBoolean:
280 case CK_FloatingCast:
281 Converted = ICE->getSubExpr();
282 continue;
283
284 default:
285 return Converted;
286 }
287 }
288
289 return Converted;
290}
291
292/// Check if this standard conversion sequence represents a narrowing
293/// conversion, according to C++11 [dcl.init.list]p7.
294///
295/// \param Ctx The AST context.
296/// \param Converted The result of applying this standard conversion sequence.
297/// \param ConstantValue If this is an NK_Constant_Narrowing conversion, the
298/// value of the expression prior to the narrowing conversion.
299/// \param ConstantType If this is an NK_Constant_Narrowing conversion, the
300/// type of the expression prior to the narrowing conversion.
301/// \param IgnoreFloatToIntegralConversion If true type-narrowing conversions
302/// from floating point types to integral types should be ignored.
303NarrowingKind StandardConversionSequence::getNarrowingKind(
304 ASTContext &Ctx, const Expr *Converted, APValue &ConstantValue,
305 QualType &ConstantType, bool IgnoreFloatToIntegralConversion) const {
306 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-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaOverload.cpp"
, 306, __PRETTY_FUNCTION__))
;
307
308 // C++11 [dcl.init.list]p7:
309 // A narrowing conversion is an implicit conversion ...
310 QualType FromType = getToType(0);
311 QualType ToType = getToType(1);
312
313 // A conversion to an enumeration type is narrowing if the conversion to
314 // the underlying type is narrowing. This only arises for expressions of
315 // the form 'Enum{init}'.
316 if (auto *ET = ToType->getAs<EnumType>())
317 ToType = ET->getDecl()->getIntegerType();
318
319 switch (Second) {
320 // 'bool' is an integral type; dispatch to the right place to handle it.
321 case ICK_Boolean_Conversion:
322 if (FromType->isRealFloatingType())
323 goto FloatingIntegralConversion;
324 if (FromType->isIntegralOrUnscopedEnumerationType())
325 goto IntegralConversion;
326 // Boolean conversions can be from pointers and pointers to members
327 // [conv.bool], and those aren't considered narrowing conversions.
328 return NK_Not_Narrowing;
329
330 // -- from a floating-point type to an integer type, or
331 //
332 // -- from an integer type or unscoped enumeration type to a floating-point
333 // type, except where the source is a constant expression and the actual
334 // value after conversion will fit into the target type and will produce
335 // the original value when converted back to the original type, or
336 case ICK_Floating_Integral:
337 FloatingIntegralConversion:
338 if (FromType->isRealFloatingType() && ToType->isIntegralType(Ctx)) {
339 return NK_Type_Narrowing;
340 } else if (FromType->isIntegralOrUnscopedEnumerationType() &&
341 ToType->isRealFloatingType()) {
342 if (IgnoreFloatToIntegralConversion)
343 return NK_Not_Narrowing;
344 llvm::APSInt IntConstantValue;
345 const Expr *Initializer = IgnoreNarrowingConversion(Ctx, Converted);
346 assert(Initializer && "Unknown conversion expression")((Initializer && "Unknown conversion expression") ? static_cast
<void> (0) : __assert_fail ("Initializer && \"Unknown conversion expression\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaOverload.cpp"
, 346, __PRETTY_FUNCTION__))
;
347
348 // If it's value-dependent, we can't tell whether it's narrowing.
349 if (Initializer->isValueDependent())
350 return NK_Dependent_Narrowing;
351
352 if (Initializer->isIntegerConstantExpr(IntConstantValue, Ctx)) {
353 // Convert the integer to the floating type.
354 llvm::APFloat Result(Ctx.getFloatTypeSemantics(ToType));
355 Result.convertFromAPInt(IntConstantValue, IntConstantValue.isSigned(),
356 llvm::APFloat::rmNearestTiesToEven);
357 // And back.
358 llvm::APSInt ConvertedValue = IntConstantValue;
359 bool ignored;
360 Result.convertToInteger(ConvertedValue,
361 llvm::APFloat::rmTowardZero, &ignored);
362 // If the resulting value is different, this was a narrowing conversion.
363 if (IntConstantValue != ConvertedValue) {
364 ConstantValue = APValue(IntConstantValue);
365 ConstantType = Initializer->getType();
366 return NK_Constant_Narrowing;
367 }
368 } else {
369 // Variables are always narrowings.
370 return NK_Variable_Narrowing;
371 }
372 }
373 return NK_Not_Narrowing;
374
375 // -- from long double to double or float, or from double to float, except
376 // where the source is a constant expression and the actual value after
377 // conversion is within the range of values that can be represented (even
378 // if it cannot be represented exactly), or
379 case ICK_Floating_Conversion:
380 if (FromType->isRealFloatingType() && ToType->isRealFloatingType() &&
381 Ctx.getFloatingTypeOrder(FromType, ToType) == 1) {
382 // FromType is larger than ToType.
383 const Expr *Initializer = IgnoreNarrowingConversion(Ctx, Converted);
384
385 // If it's value-dependent, we can't tell whether it's narrowing.
386 if (Initializer->isValueDependent())
387 return NK_Dependent_Narrowing;
388
389 if (Initializer->isCXX11ConstantExpr(Ctx, &ConstantValue)) {
390 // Constant!
391 assert(ConstantValue.isFloat())((ConstantValue.isFloat()) ? static_cast<void> (0) : __assert_fail
("ConstantValue.isFloat()", "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaOverload.cpp"
, 391, __PRETTY_FUNCTION__))
;
392 llvm::APFloat FloatVal = ConstantValue.getFloat();
393 // Convert the source value into the target type.
394 bool ignored;
395 llvm::APFloat::opStatus ConvertStatus = FloatVal.convert(
396 Ctx.getFloatTypeSemantics(ToType),
397 llvm::APFloat::rmNearestTiesToEven, &ignored);
398 // If there was no overflow, the source value is within the range of
399 // values that can be represented.
400 if (ConvertStatus & llvm::APFloat::opOverflow) {
401 ConstantType = Initializer->getType();
402 return NK_Constant_Narrowing;
403 }
404 } else {
405 return NK_Variable_Narrowing;
406 }
407 }
408 return NK_Not_Narrowing;
409
410 // -- from an integer type or unscoped enumeration type to an integer type
411 // that cannot represent all the values of the original type, except where
412 // the source is a constant expression and the actual value after
413 // conversion will fit into the target type and will produce the original
414 // value when converted back to the original type.
415 case ICK_Integral_Conversion:
416 IntegralConversion: {
417 assert(FromType->isIntegralOrUnscopedEnumerationType())((FromType->isIntegralOrUnscopedEnumerationType()) ? static_cast
<void> (0) : __assert_fail ("FromType->isIntegralOrUnscopedEnumerationType()"
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaOverload.cpp"
, 417, __PRETTY_FUNCTION__))
;
418 assert(ToType->isIntegralOrUnscopedEnumerationType())((ToType->isIntegralOrUnscopedEnumerationType()) ? static_cast
<void> (0) : __assert_fail ("ToType->isIntegralOrUnscopedEnumerationType()"
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaOverload.cpp"
, 418, __PRETTY_FUNCTION__))
;
419 const bool FromSigned = FromType->isSignedIntegerOrEnumerationType();
420 const unsigned FromWidth = Ctx.getIntWidth(FromType);
421 const bool ToSigned = ToType->isSignedIntegerOrEnumerationType();
422 const unsigned ToWidth = Ctx.getIntWidth(ToType);
423
424 if (FromWidth > ToWidth ||
425 (FromWidth == ToWidth && FromSigned != ToSigned) ||
426 (FromSigned && !ToSigned)) {
427 // Not all values of FromType can be represented in ToType.
428 llvm::APSInt InitializerValue;
429 const Expr *Initializer = IgnoreNarrowingConversion(Ctx, Converted);
430
431 // If it's value-dependent, we can't tell whether it's narrowing.
432 if (Initializer->isValueDependent())
433 return NK_Dependent_Narrowing;
434
435 if (!Initializer->isIntegerConstantExpr(InitializerValue, Ctx)) {
436 // Such conversions on variables are always narrowing.
437 return NK_Variable_Narrowing;
438 }
439 bool Narrowing = false;
440 if (FromWidth < ToWidth) {
441 // Negative -> unsigned is narrowing. Otherwise, more bits is never
442 // narrowing.
443 if (InitializerValue.isSigned() && InitializerValue.isNegative())
444 Narrowing = true;
445 } else {
446 // Add a bit to the InitializerValue so we don't have to worry about
447 // signed vs. unsigned comparisons.
448 InitializerValue = InitializerValue.extend(
449 InitializerValue.getBitWidth() + 1);
450 // Convert the initializer to and from the target width and signed-ness.
451 llvm::APSInt ConvertedValue = InitializerValue;
452 ConvertedValue = ConvertedValue.trunc(ToWidth);
453 ConvertedValue.setIsSigned(ToSigned);
454 ConvertedValue = ConvertedValue.extend(InitializerValue.getBitWidth());
455 ConvertedValue.setIsSigned(InitializerValue.isSigned());
456 // If the result is different, this was a narrowing conversion.
457 if (ConvertedValue != InitializerValue)
458 Narrowing = true;
459 }
460 if (Narrowing) {
461 ConstantType = Initializer->getType();
462 ConstantValue = APValue(InitializerValue);
463 return NK_Constant_Narrowing;
464 }
465 }
466 return NK_Not_Narrowing;
467 }
468
469 default:
470 // Other kinds of conversions are not narrowings.
471 return NK_Not_Narrowing;
472 }
473}
474
475/// dump - Print this standard conversion sequence to standard
476/// error. Useful for debugging overloading issues.
477LLVM_DUMP_METHOD__attribute__((noinline)) __attribute__((__used__)) void StandardConversionSequence::dump() const {
478 raw_ostream &OS = llvm::errs();
479 bool PrintedSomething = false;
480 if (First != ICK_Identity) {
481 OS << GetImplicitConversionName(First);
482 PrintedSomething = true;
483 }
484
485 if (Second != ICK_Identity) {
486 if (PrintedSomething) {
487 OS << " -> ";
488 }
489 OS << GetImplicitConversionName(Second);
490
491 if (CopyConstructor) {
492 OS << " (by copy constructor)";
493 } else if (DirectBinding) {
494 OS << " (direct reference binding)";
495 } else if (ReferenceBinding) {
496 OS << " (reference binding)";
497 }
498 PrintedSomething = true;
499 }
500
501 if (Third != ICK_Identity) {
502 if (PrintedSomething) {
503 OS << " -> ";
504 }
505 OS << GetImplicitConversionName(Third);
506 PrintedSomething = true;
507 }
508
509 if (!PrintedSomething) {
510 OS << "No conversions required";
511 }
512}
513
514/// dump - Print this user-defined conversion sequence to standard
515/// error. Useful for debugging overloading issues.
516void UserDefinedConversionSequence::dump() const {
517 raw_ostream &OS = llvm::errs();
518 if (Before.First || Before.Second || Before.Third) {
519 Before.dump();
520 OS << " -> ";
521 }
522 if (ConversionFunction)
523 OS << '\'' << *ConversionFunction << '\'';
524 else
525 OS << "aggregate initialization";
526 if (After.First || After.Second || After.Third) {
527 OS << " -> ";
528 After.dump();
529 }
530}
531
532/// dump - Print this implicit conversion sequence to standard
533/// error. Useful for debugging overloading issues.
534void ImplicitConversionSequence::dump() const {
535 raw_ostream &OS = llvm::errs();
536 if (isStdInitializerListElement())
537 OS << "Worst std::initializer_list element conversion: ";
538 switch (ConversionKind) {
539 case StandardConversion:
540 OS << "Standard conversion: ";
541 Standard.dump();
542 break;
543 case UserDefinedConversion:
544 OS << "User-defined conversion: ";
545 UserDefined.dump();
546 break;
547 case EllipsisConversion:
548 OS << "Ellipsis conversion";
549 break;
550 case AmbiguousConversion:
551 OS << "Ambiguous conversion";
552 break;
553 case BadConversion:
554 OS << "Bad conversion";
555 break;
556 }
557
558 OS << "\n";
559}
560
561void AmbiguousConversionSequence::construct() {
562 new (&conversions()) ConversionSet();
563}
564
565void AmbiguousConversionSequence::destruct() {
566 conversions().~ConversionSet();
567}
568
569void
570AmbiguousConversionSequence::copyFrom(const AmbiguousConversionSequence &O) {
571 FromTypePtr = O.FromTypePtr;
572 ToTypePtr = O.ToTypePtr;
573 new (&conversions()) ConversionSet(O.conversions());
574}
575
576namespace {
577 // Structure used by DeductionFailureInfo to store
578 // template argument information.
579 struct DFIArguments {
580 TemplateArgument FirstArg;
581 TemplateArgument SecondArg;
582 };
583 // Structure used by DeductionFailureInfo to store
584 // template parameter and template argument information.
585 struct DFIParamWithArguments : DFIArguments {
586 TemplateParameter Param;
587 };
588 // Structure used by DeductionFailureInfo to store template argument
589 // information and the index of the problematic call argument.
590 struct DFIDeducedMismatchArgs : DFIArguments {
591 TemplateArgumentList *TemplateArgs;
592 unsigned CallArgIndex;
593 };
594}
595
596/// Convert from Sema's representation of template deduction information
597/// to the form used in overload-candidate information.
598DeductionFailureInfo
599clang::MakeDeductionFailureInfo(ASTContext &Context,
600 Sema::TemplateDeductionResult TDK,
601 TemplateDeductionInfo &Info) {
602 DeductionFailureInfo Result;
603 Result.Result = static_cast<unsigned>(TDK);
604 Result.HasDiagnostic = false;
605 switch (TDK) {
606 case Sema::TDK_Invalid:
607 case Sema::TDK_InstantiationDepth:
608 case Sema::TDK_TooManyArguments:
609 case Sema::TDK_TooFewArguments:
610 case Sema::TDK_MiscellaneousDeductionFailure:
611 case Sema::TDK_CUDATargetMismatch:
612 Result.Data = nullptr;
613 break;
614
615 case Sema::TDK_Incomplete:
616 case Sema::TDK_InvalidExplicitArguments:
617 Result.Data = Info.Param.getOpaqueValue();
618 break;
619
620 case Sema::TDK_DeducedMismatch:
621 case Sema::TDK_DeducedMismatchNested: {
622 // FIXME: Should allocate from normal heap so that we can free this later.
623 auto *Saved = new (Context) DFIDeducedMismatchArgs;
624 Saved->FirstArg = Info.FirstArg;
625 Saved->SecondArg = Info.SecondArg;
626 Saved->TemplateArgs = Info.take();
627 Saved->CallArgIndex = Info.CallArgIndex;
628 Result.Data = Saved;
629 break;
630 }
631
632 case Sema::TDK_NonDeducedMismatch: {
633 // FIXME: Should allocate from normal heap so that we can free this later.
634 DFIArguments *Saved = new (Context) DFIArguments;
635 Saved->FirstArg = Info.FirstArg;
636 Saved->SecondArg = Info.SecondArg;
637 Result.Data = Saved;
638 break;
639 }
640
641 case Sema::TDK_IncompletePack:
642 // FIXME: It's slightly wasteful to allocate two TemplateArguments for this.
643 case Sema::TDK_Inconsistent:
644 case Sema::TDK_Underqualified: {
645 // FIXME: Should allocate from normal heap so that we can free this later.
646 DFIParamWithArguments *Saved = new (Context) DFIParamWithArguments;
647 Saved->Param = Info.Param;
648 Saved->FirstArg = Info.FirstArg;
649 Saved->SecondArg = Info.SecondArg;
650 Result.Data = Saved;
651 break;
652 }
653
654 case Sema::TDK_SubstitutionFailure:
655 Result.Data = Info.take();
656 if (Info.hasSFINAEDiagnostic()) {
657 PartialDiagnosticAt *Diag = new (Result.Diagnostic) PartialDiagnosticAt(
658 SourceLocation(), PartialDiagnostic::NullDiagnostic());
659 Info.takeSFINAEDiagnostic(*Diag);
660 Result.HasDiagnostic = true;
661 }
662 break;
663
664 case Sema::TDK_Success:
665 case Sema::TDK_NonDependentConversionFailure:
666 llvm_unreachable("not a deduction failure")::llvm::llvm_unreachable_internal("not a deduction failure", "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaOverload.cpp"
, 666)
;
667 }
668
669 return Result;
670}
671
672void DeductionFailureInfo::Destroy() {
673 switch (static_cast<Sema::TemplateDeductionResult>(Result)) {
674 case Sema::TDK_Success:
675 case Sema::TDK_Invalid:
676 case Sema::TDK_InstantiationDepth:
677 case Sema::TDK_Incomplete:
678 case Sema::TDK_TooManyArguments:
679 case Sema::TDK_TooFewArguments:
680 case Sema::TDK_InvalidExplicitArguments:
681 case Sema::TDK_CUDATargetMismatch:
682 case Sema::TDK_NonDependentConversionFailure:
683 break;
684
685 case Sema::TDK_IncompletePack:
686 case Sema::TDK_Inconsistent:
687 case Sema::TDK_Underqualified:
688 case Sema::TDK_DeducedMismatch:
689 case Sema::TDK_DeducedMismatchNested:
690 case Sema::TDK_NonDeducedMismatch:
691 // FIXME: Destroy the data?
692 Data = nullptr;
693 break;
694
695 case Sema::TDK_SubstitutionFailure:
696 // FIXME: Destroy the template argument list?
697 Data = nullptr;
698 if (PartialDiagnosticAt *Diag = getSFINAEDiagnostic()) {
699 Diag->~PartialDiagnosticAt();
700 HasDiagnostic = false;
701 }
702 break;
703
704 // Unhandled
705 case Sema::TDK_MiscellaneousDeductionFailure:
706 break;
707 }
708}
709
710PartialDiagnosticAt *DeductionFailureInfo::getSFINAEDiagnostic() {
711 if (HasDiagnostic)
712 return static_cast<PartialDiagnosticAt*>(static_cast<void*>(Diagnostic));
713 return nullptr;
714}
715
716TemplateParameter DeductionFailureInfo::getTemplateParameter() {
717 switch (static_cast<Sema::TemplateDeductionResult>(Result)) {
718 case Sema::TDK_Success:
719 case Sema::TDK_Invalid:
720 case Sema::TDK_InstantiationDepth:
721 case Sema::TDK_TooManyArguments:
722 case Sema::TDK_TooFewArguments:
723 case Sema::TDK_SubstitutionFailure:
724 case Sema::TDK_DeducedMismatch:
725 case Sema::TDK_DeducedMismatchNested:
726 case Sema::TDK_NonDeducedMismatch:
727 case Sema::TDK_CUDATargetMismatch:
728 case Sema::TDK_NonDependentConversionFailure:
729 return TemplateParameter();
730
731 case Sema::TDK_Incomplete:
732 case Sema::TDK_InvalidExplicitArguments:
733 return TemplateParameter::getFromOpaqueValue(Data);
734
735 case Sema::TDK_IncompletePack:
736 case Sema::TDK_Inconsistent:
737 case Sema::TDK_Underqualified:
738 return static_cast<DFIParamWithArguments*>(Data)->Param;
739
740 // Unhandled
741 case Sema::TDK_MiscellaneousDeductionFailure:
742 break;
743 }
744
745 return TemplateParameter();
746}
747
748TemplateArgumentList *DeductionFailureInfo::getTemplateArgumentList() {
749 switch (static_cast<Sema::TemplateDeductionResult>(Result)) {
750 case Sema::TDK_Success:
751 case Sema::TDK_Invalid:
752 case Sema::TDK_InstantiationDepth:
753 case Sema::TDK_TooManyArguments:
754 case Sema::TDK_TooFewArguments:
755 case Sema::TDK_Incomplete:
756 case Sema::TDK_IncompletePack:
757 case Sema::TDK_InvalidExplicitArguments:
758 case Sema::TDK_Inconsistent:
759 case Sema::TDK_Underqualified:
760 case Sema::TDK_NonDeducedMismatch:
761 case Sema::TDK_CUDATargetMismatch:
762 case Sema::TDK_NonDependentConversionFailure:
763 return nullptr;
764
765 case Sema::TDK_DeducedMismatch:
766 case Sema::TDK_DeducedMismatchNested:
767 return static_cast<DFIDeducedMismatchArgs*>(Data)->TemplateArgs;
768
769 case Sema::TDK_SubstitutionFailure:
770 return static_cast<TemplateArgumentList*>(Data);
771
772 // Unhandled
773 case Sema::TDK_MiscellaneousDeductionFailure:
774 break;
775 }
776
777 return nullptr;
778}
779
780const TemplateArgument *DeductionFailureInfo::getFirstArg() {
781 switch (static_cast<Sema::TemplateDeductionResult>(Result)) {
782 case Sema::TDK_Success:
783 case Sema::TDK_Invalid:
784 case Sema::TDK_InstantiationDepth:
785 case Sema::TDK_Incomplete:
786 case Sema::TDK_TooManyArguments:
787 case Sema::TDK_TooFewArguments:
788 case Sema::TDK_InvalidExplicitArguments:
789 case Sema::TDK_SubstitutionFailure:
790 case Sema::TDK_CUDATargetMismatch:
791 case Sema::TDK_NonDependentConversionFailure:
792 return nullptr;
793
794 case Sema::TDK_IncompletePack:
795 case Sema::TDK_Inconsistent:
796 case Sema::TDK_Underqualified:
797 case Sema::TDK_DeducedMismatch:
798 case Sema::TDK_DeducedMismatchNested:
799 case Sema::TDK_NonDeducedMismatch:
800 return &static_cast<DFIArguments*>(Data)->FirstArg;
801
802 // Unhandled
803 case Sema::TDK_MiscellaneousDeductionFailure:
804 break;
805 }
806
807 return nullptr;
808}
809
810const TemplateArgument *DeductionFailureInfo::getSecondArg() {
811 switch (static_cast<Sema::TemplateDeductionResult>(Result)) {
812 case Sema::TDK_Success:
813 case Sema::TDK_Invalid:
814 case Sema::TDK_InstantiationDepth:
815 case Sema::TDK_Incomplete:
816 case Sema::TDK_IncompletePack:
817 case Sema::TDK_TooManyArguments:
818 case Sema::TDK_TooFewArguments:
819 case Sema::TDK_InvalidExplicitArguments:
820 case Sema::TDK_SubstitutionFailure:
821 case Sema::TDK_CUDATargetMismatch:
822 case Sema::TDK_NonDependentConversionFailure:
823 return nullptr;
824
825 case Sema::TDK_Inconsistent:
826 case Sema::TDK_Underqualified:
827 case Sema::TDK_DeducedMismatch:
828 case Sema::TDK_DeducedMismatchNested:
829 case Sema::TDK_NonDeducedMismatch:
830 return &static_cast<DFIArguments*>(Data)->SecondArg;
831
832 // Unhandled
833 case Sema::TDK_MiscellaneousDeductionFailure:
834 break;
835 }
836
837 return nullptr;
838}
839
840llvm::Optional<unsigned> DeductionFailureInfo::getCallArgIndex() {
841 switch (static_cast<Sema::TemplateDeductionResult>(Result)) {
842 case Sema::TDK_DeducedMismatch:
843 case Sema::TDK_DeducedMismatchNested:
844 return static_cast<DFIDeducedMismatchArgs*>(Data)->CallArgIndex;
845
846 default:
847 return llvm::None;
848 }
849}
850
851bool OverloadCandidateSet::OperatorRewriteInfo::shouldAddReversed(
852 OverloadedOperatorKind Op) {
853 if (!AllowRewrittenCandidates)
854 return false;
855 return Op == OO_EqualEqual || Op == OO_Spaceship;
856}
857
858bool OverloadCandidateSet::OperatorRewriteInfo::shouldAddReversed(
859 ASTContext &Ctx, const FunctionDecl *FD) {
860 if (!shouldAddReversed(FD->getDeclName().getCXXOverloadedOperator()))
861 return false;
862 // Don't bother adding a reversed candidate that can never be a better
863 // match than the non-reversed version.
864 return FD->getNumParams() != 2 ||
865 !Ctx.hasSameUnqualifiedType(FD->getParamDecl(0)->getType(),
866 FD->getParamDecl(1)->getType()) ||
867 FD->hasAttr<EnableIfAttr>();
868}
869
870void OverloadCandidateSet::destroyCandidates() {
871 for (iterator i = begin(), e = end(); i != e; ++i) {
872 for (auto &C : i->Conversions)
873 C.~ImplicitConversionSequence();
874 if (!i->Viable && i->FailureKind == ovl_fail_bad_deduction)
875 i->DeductionFailure.Destroy();
876 }
877}
878
879void OverloadCandidateSet::clear(CandidateSetKind CSK) {
880 destroyCandidates();
881 SlabAllocator.Reset();
882 NumInlineBytesUsed = 0;
883 Candidates.clear();
884 Functions.clear();
885 Kind = CSK;
886}
887
888namespace {
889 class UnbridgedCastsSet {
890 struct Entry {
891 Expr **Addr;
892 Expr *Saved;
893 };
894 SmallVector<Entry, 2> Entries;
895
896 public:
897 void save(Sema &S, Expr *&E) {
898 assert(E->hasPlaceholderType(BuiltinType::ARCUnbridgedCast))((E->hasPlaceholderType(BuiltinType::ARCUnbridgedCast)) ? static_cast
<void> (0) : __assert_fail ("E->hasPlaceholderType(BuiltinType::ARCUnbridgedCast)"
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaOverload.cpp"
, 898, __PRETTY_FUNCTION__))
;
899 Entry entry = { &E, E };
900 Entries.push_back(entry);
901 E = S.stripARCUnbridgedCast(E);
902 }
903
904 void restore() {
905 for (SmallVectorImpl<Entry>::iterator
906 i = Entries.begin(), e = Entries.end(); i != e; ++i)
907 *i->Addr = i->Saved;
908 }
909 };
910}
911
912/// checkPlaceholderForOverload - Do any interesting placeholder-like
913/// preprocessing on the given expression.
914///
915/// \param unbridgedCasts a collection to which to add unbridged casts;
916/// without this, they will be immediately diagnosed as errors
917///
918/// Return true on unrecoverable error.
919static bool
920checkPlaceholderForOverload(Sema &S, Expr *&E,
921 UnbridgedCastsSet *unbridgedCasts = nullptr) {
922 if (const BuiltinType *placeholder = E->getType()->getAsPlaceholderType()) {
923 // We can't handle overloaded expressions here because overload
924 // resolution might reasonably tweak them.
925 if (placeholder->getKind() == BuiltinType::Overload) return false;
926
927 // If the context potentially accepts unbridged ARC casts, strip
928 // the unbridged cast and add it to the collection for later restoration.
929 if (placeholder->getKind() == BuiltinType::ARCUnbridgedCast &&
930 unbridgedCasts) {
931 unbridgedCasts->save(S, E);
932 return false;
933 }
934
935 // Go ahead and check everything else.
936 ExprResult result = S.CheckPlaceholderExpr(E);
937 if (result.isInvalid())
938 return true;
939
940 E = result.get();
941 return false;
942 }
943
944 // Nothing to do.
945 return false;
946}
947
948/// checkArgPlaceholdersForOverload - Check a set of call operands for
949/// placeholders.
950static bool checkArgPlaceholdersForOverload(Sema &S,
951 MultiExprArg Args,
952 UnbridgedCastsSet &unbridged) {
953 for (unsigned i = 0, e = Args.size(); i != e; ++i)
954 if (checkPlaceholderForOverload(S, Args[i], &unbridged))
955 return true;
956
957 return false;
958}
959
960/// Determine whether the given New declaration is an overload of the
961/// declarations in Old. This routine returns Ovl_Match or Ovl_NonFunction if
962/// New and Old cannot be overloaded, e.g., if New has the same signature as
963/// some function in Old (C++ 1.3.10) or if the Old declarations aren't
964/// functions (or function templates) at all. When it does return Ovl_Match or
965/// Ovl_NonFunction, MatchedDecl will point to the decl that New cannot be
966/// overloaded with. This decl may be a UsingShadowDecl on top of the underlying
967/// declaration.
968///
969/// Example: Given the following input:
970///
971/// void f(int, float); // #1
972/// void f(int, int); // #2
973/// int f(int, int); // #3
974///
975/// When we process #1, there is no previous declaration of "f", so IsOverload
976/// will not be used.
977///
978/// When we process #2, Old contains only the FunctionDecl for #1. By comparing
979/// the parameter types, we see that #1 and #2 are overloaded (since they have
980/// different signatures), so this routine returns Ovl_Overload; MatchedDecl is
981/// unchanged.
982///
983/// When we process #3, Old is an overload set containing #1 and #2. We compare
984/// the signatures of #3 to #1 (they're overloaded, so we do nothing) and then
985/// #3 to #2. Since the signatures of #3 and #2 are identical (return types of
986/// functions are not part of the signature), IsOverload returns Ovl_Match and
987/// MatchedDecl will be set to point to the FunctionDecl for #2.
988///
989/// 'NewIsUsingShadowDecl' indicates that 'New' is being introduced into a class
990/// by a using declaration. The rules for whether to hide shadow declarations
991/// ignore some properties which otherwise figure into a function template's
992/// signature.
993Sema::OverloadKind
994Sema::CheckOverload(Scope *S, FunctionDecl *New, const LookupResult &Old,
995 NamedDecl *&Match, bool NewIsUsingDecl) {
996 for (LookupResult::iterator I = Old.begin(), E = Old.end();
997 I != E; ++I) {
998 NamedDecl *OldD = *I;
999
1000 bool OldIsUsingDecl = false;
1001 if (isa<UsingShadowDecl>(OldD)) {
1002 OldIsUsingDecl = true;
1003
1004 // We can always introduce two using declarations into the same
1005 // context, even if they have identical signatures.
1006 if (NewIsUsingDecl) continue;
1007
1008 OldD = cast<UsingShadowDecl>(OldD)->getTargetDecl();
1009 }
1010
1011 // A using-declaration does not conflict with another declaration
1012 // if one of them is hidden.
1013 if ((OldIsUsingDecl || NewIsUsingDecl) && !isVisible(*I))
1014 continue;
1015
1016 // If either declaration was introduced by a using declaration,
1017 // we'll need to use slightly different rules for matching.
1018 // Essentially, these rules are the normal rules, except that
1019 // function templates hide function templates with different
1020 // return types or template parameter lists.
1021 bool UseMemberUsingDeclRules =
1022 (OldIsUsingDecl || NewIsUsingDecl) && CurContext->isRecord() &&
1023 !New->getFriendObjectKind();
1024
1025 if (FunctionDecl *OldF = OldD->getAsFunction()) {
1026 if (!IsOverload(New, OldF, UseMemberUsingDeclRules)) {
1027 if (UseMemberUsingDeclRules && OldIsUsingDecl) {
1028 HideUsingShadowDecl(S, cast<UsingShadowDecl>(*I));
1029 continue;
1030 }
1031
1032 if (!isa<FunctionTemplateDecl>(OldD) &&
1033 !shouldLinkPossiblyHiddenDecl(*I, New))
1034 continue;
1035
1036 Match = *I;
1037 return Ovl_Match;
1038 }
1039
1040 // Builtins that have custom typechecking or have a reference should
1041 // not be overloadable or redeclarable.
1042 if (!getASTContext().canBuiltinBeRedeclared(OldF)) {
1043 Match = *I;
1044 return Ovl_NonFunction;
1045 }
1046 } else if (isa<UsingDecl>(OldD) || isa<UsingPackDecl>(OldD)) {
1047 // We can overload with these, which can show up when doing
1048 // redeclaration checks for UsingDecls.
1049 assert(Old.getLookupKind() == LookupUsingDeclName)((Old.getLookupKind() == LookupUsingDeclName) ? static_cast<
void> (0) : __assert_fail ("Old.getLookupKind() == LookupUsingDeclName"
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaOverload.cpp"
, 1049, __PRETTY_FUNCTION__))
;
1050 } else if (isa<TagDecl>(OldD)) {
1051 // We can always overload with tags by hiding them.
1052 } else if (auto *UUD = dyn_cast<UnresolvedUsingValueDecl>(OldD)) {
1053 // Optimistically assume that an unresolved using decl will
1054 // overload; if it doesn't, we'll have to diagnose during
1055 // template instantiation.
1056 //
1057 // Exception: if the scope is dependent and this is not a class
1058 // member, the using declaration can only introduce an enumerator.
1059 if (UUD->getQualifier()->isDependent() && !UUD->isCXXClassMember()) {
1060 Match = *I;
1061 return Ovl_NonFunction;
1062 }
1063 } else {
1064 // (C++ 13p1):
1065 // Only function declarations can be overloaded; object and type
1066 // declarations cannot be overloaded.
1067 Match = *I;
1068 return Ovl_NonFunction;
1069 }
1070 }
1071
1072 // C++ [temp.friend]p1:
1073 // For a friend function declaration that is not a template declaration:
1074 // -- if the name of the friend is a qualified or unqualified template-id,
1075 // [...], otherwise
1076 // -- if the name of the friend is a qualified-id and a matching
1077 // non-template function is found in the specified class or namespace,
1078 // the friend declaration refers to that function, otherwise,
1079 // -- if the name of the friend is a qualified-id and a matching function
1080 // template is found in the specified class or namespace, the friend
1081 // declaration refers to the deduced specialization of that function
1082 // template, otherwise
1083 // -- the name shall be an unqualified-id [...]
1084 // If we get here for a qualified friend declaration, we've just reached the
1085 // third bullet. If the type of the friend is dependent, skip this lookup
1086 // until instantiation.
1087 if (New->getFriendObjectKind() && New->getQualifier() &&
1088 !New->getDescribedFunctionTemplate() &&
1089 !New->getDependentSpecializationInfo() &&
1090 !New->getType()->isDependentType()) {
1091 LookupResult TemplateSpecResult(LookupResult::Temporary, Old);
1092 TemplateSpecResult.addAllDecls(Old);
1093 if (CheckFunctionTemplateSpecialization(New, nullptr, TemplateSpecResult,
1094 /*QualifiedFriend*/true)) {
1095 New->setInvalidDecl();
1096 return Ovl_Overload;
1097 }
1098
1099 Match = TemplateSpecResult.getAsSingle<FunctionDecl>();
1100 return Ovl_Match;
1101 }
1102
1103 return Ovl_Overload;
1104}
1105
1106bool Sema::IsOverload(FunctionDecl *New, FunctionDecl *Old,
1107 bool UseMemberUsingDeclRules, bool ConsiderCudaAttrs) {
1108 // C++ [basic.start.main]p2: This function shall not be overloaded.
1109 if (New->isMain())
1110 return false;
1111
1112 // MSVCRT user defined entry points cannot be overloaded.
1113 if (New->isMSVCRTEntryPoint())
1114 return false;
1115
1116 FunctionTemplateDecl *OldTemplate = Old->getDescribedFunctionTemplate();
1117 FunctionTemplateDecl *NewTemplate = New->getDescribedFunctionTemplate();
1118
1119 // C++ [temp.fct]p2:
1120 // A function template can be overloaded with other function templates
1121 // and with normal (non-template) functions.
1122 if ((OldTemplate == nullptr) != (NewTemplate == nullptr))
1123 return true;
1124
1125 // Is the function New an overload of the function Old?
1126 QualType OldQType = Context.getCanonicalType(Old->getType());
1127 QualType NewQType = Context.getCanonicalType(New->getType());
1128
1129 // Compare the signatures (C++ 1.3.10) of the two functions to
1130 // determine whether they are overloads. If we find any mismatch
1131 // in the signature, they are overloads.
1132
1133 // If either of these functions is a K&R-style function (no
1134 // prototype), then we consider them to have matching signatures.
1135 if (isa<FunctionNoProtoType>(OldQType.getTypePtr()) ||
1136 isa<FunctionNoProtoType>(NewQType.getTypePtr()))
1137 return false;
1138
1139 const FunctionProtoType *OldType = cast<FunctionProtoType>(OldQType);
1140 const FunctionProtoType *NewType = cast<FunctionProtoType>(NewQType);
1141
1142 // The signature of a function includes the types of its
1143 // parameters (C++ 1.3.10), which includes the presence or absence
1144 // of the ellipsis; see C++ DR 357).
1145 if (OldQType != NewQType &&
1146 (OldType->getNumParams() != NewType->getNumParams() ||
1147 OldType->isVariadic() != NewType->isVariadic() ||
1148 !FunctionParamTypesAreEqual(OldType, NewType)))
1149 return true;
1150
1151 // C++ [temp.over.link]p4:
1152 // The signature of a function template consists of its function
1153 // signature, its return type and its template parameter list. The names
1154 // of the template parameters are significant only for establishing the
1155 // relationship between the template parameters and the rest of the
1156 // signature.
1157 //
1158 // We check the return type and template parameter lists for function
1159 // templates first; the remaining checks follow.
1160 //
1161 // However, we don't consider either of these when deciding whether
1162 // a member introduced by a shadow declaration is hidden.
1163 if (!UseMemberUsingDeclRules && NewTemplate &&
1164 (!TemplateParameterListsAreEqual(NewTemplate->getTemplateParameters(),
1165 OldTemplate->getTemplateParameters(),
1166 false, TPL_TemplateMatch) ||
1167 !Context.hasSameType(Old->getDeclaredReturnType(),
1168 New->getDeclaredReturnType())))
1169 return true;
1170
1171 // If the function is a class member, its signature includes the
1172 // cv-qualifiers (if any) and ref-qualifier (if any) on the function itself.
1173 //
1174 // As part of this, also check whether one of the member functions
1175 // is static, in which case they are not overloads (C++
1176 // 13.1p2). While not part of the definition of the signature,
1177 // this check is important to determine whether these functions
1178 // can be overloaded.
1179 CXXMethodDecl *OldMethod = dyn_cast<CXXMethodDecl>(Old);
1180 CXXMethodDecl *NewMethod = dyn_cast<CXXMethodDecl>(New);
1181 if (OldMethod && NewMethod &&
1182 !OldMethod->isStatic() && !NewMethod->isStatic()) {
1183 if (OldMethod->getRefQualifier() != NewMethod->getRefQualifier()) {
1184 if (!UseMemberUsingDeclRules &&
1185 (OldMethod->getRefQualifier() == RQ_None ||
1186 NewMethod->getRefQualifier() == RQ_None)) {
1187 // C++0x [over.load]p2:
1188 // - Member function declarations with the same name and the same
1189 // parameter-type-list as well as member function template
1190 // declarations with the same name, the same parameter-type-list, and
1191 // the same template parameter lists cannot be overloaded if any of
1192 // them, but not all, have a ref-qualifier (8.3.5).
1193 Diag(NewMethod->getLocation(), diag::err_ref_qualifier_overload)
1194 << NewMethod->getRefQualifier() << OldMethod->getRefQualifier();
1195 Diag(OldMethod->getLocation(), diag::note_previous_declaration);
1196 }
1197 return true;
1198 }
1199
1200 // We may not have applied the implicit const for a constexpr member
1201 // function yet (because we haven't yet resolved whether this is a static
1202 // or non-static member function). Add it now, on the assumption that this
1203 // is a redeclaration of OldMethod.
1204 auto OldQuals = OldMethod->getMethodQualifiers();
1205 auto NewQuals = NewMethod->getMethodQualifiers();
1206 if (!getLangOpts().CPlusPlus14 && NewMethod->isConstexpr() &&
1207 !isa<CXXConstructorDecl>(NewMethod))
1208 NewQuals.addConst();
1209 // We do not allow overloading based off of '__restrict'.
1210 OldQuals.removeRestrict();
1211 NewQuals.removeRestrict();
1212 if (OldQuals != NewQuals)
1213 return true;
1214 }
1215
1216 // Though pass_object_size is placed on parameters and takes an argument, we
1217 // consider it to be a function-level modifier for the sake of function
1218 // identity. Either the function has one or more parameters with
1219 // pass_object_size or it doesn't.
1220 if (functionHasPassObjectSizeParams(New) !=
1221 functionHasPassObjectSizeParams(Old))
1222 return true;
1223
1224 // enable_if attributes are an order-sensitive part of the signature.
1225 for (specific_attr_iterator<EnableIfAttr>
1226 NewI = New->specific_attr_begin<EnableIfAttr>(),
1227 NewE = New->specific_attr_end<EnableIfAttr>(),
1228 OldI = Old->specific_attr_begin<EnableIfAttr>(),
1229 OldE = Old->specific_attr_end<EnableIfAttr>();
1230 NewI != NewE || OldI != OldE; ++NewI, ++OldI) {
1231 if (NewI == NewE || OldI == OldE)
1232 return true;
1233 llvm::FoldingSetNodeID NewID, OldID;
1234 NewI->getCond()->Profile(NewID, Context, true);
1235 OldI->getCond()->Profile(OldID, Context, true);
1236 if (NewID != OldID)
1237 return true;
1238 }
1239
1240 if (getLangOpts().CUDA && ConsiderCudaAttrs) {
1241 // Don't allow overloading of destructors. (In theory we could, but it
1242 // would be a giant change to clang.)
1243 if (isa<CXXDestructorDecl>(New))
1244 return false;
1245
1246 CUDAFunctionTarget NewTarget = IdentifyCUDATarget(New),
1247 OldTarget = IdentifyCUDATarget(Old);
1248 if (NewTarget == CFT_InvalidTarget)
1249 return false;
1250
1251 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-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaOverload.cpp"
, 1251, __PRETTY_FUNCTION__))
;
1252
1253 // Allow overloading of functions with same signature and different CUDA
1254 // target attributes.
1255 return NewTarget != OldTarget;
1256 }
1257
1258 // The signatures match; this is not an overload.
1259 return false;
1260}
1261
1262/// Tries a user-defined conversion from From to ToType.
1263///
1264/// Produces an implicit conversion sequence for when a standard conversion
1265/// is not an option. See TryImplicitConversion for more information.
1266static ImplicitConversionSequence
1267TryUserDefinedConversion(Sema &S, Expr *From, QualType ToType,
1268 bool SuppressUserConversions,
1269 bool AllowExplicit,
1270 bool InOverloadResolution,
1271 bool CStyle,
1272 bool AllowObjCWritebackConversion,
1273 bool AllowObjCConversionOnExplicit) {
1274 ImplicitConversionSequence ICS;
1275
1276 if (SuppressUserConversions) {
1277 // We're not in the case above, so there is no conversion that
1278 // we can perform.
1279 ICS.setBad(BadConversionSequence::no_conversion, From, ToType);
1280 return ICS;
1281 }
1282
1283 // Attempt user-defined conversion.
1284 OverloadCandidateSet Conversions(From->getExprLoc(),
1285 OverloadCandidateSet::CSK_Normal);
1286 switch (IsUserDefinedConversion(S, From, ToType, ICS.UserDefined,
1287 Conversions, AllowExplicit,
1288 AllowObjCConversionOnExplicit)) {
1289 case OR_Success:
1290 case OR_Deleted:
1291 ICS.setUserDefined();
1292 // C++ [over.ics.user]p4:
1293 // A conversion of an expression of class type to the same class
1294 // type is given Exact Match rank, and a conversion of an
1295 // expression of class type to a base class of that type is
1296 // given Conversion rank, in spite of the fact that a copy
1297 // constructor (i.e., a user-defined conversion function) is
1298 // called for those cases.
1299 if (CXXConstructorDecl *Constructor
1300 = dyn_cast<CXXConstructorDecl>(ICS.UserDefined.ConversionFunction)) {
1301 QualType FromCanon
1302 = S.Context.getCanonicalType(From->getType().getUnqualifiedType());
1303 QualType ToCanon
1304 = S.Context.getCanonicalType(ToType).getUnqualifiedType();
1305 if (Constructor->isCopyConstructor() &&
1306 (FromCanon == ToCanon ||
1307 S.IsDerivedFrom(From->getBeginLoc(), FromCanon, ToCanon))) {
1308 // Turn this into a "standard" conversion sequence, so that it
1309 // gets ranked with standard conversion sequences.
1310 DeclAccessPair Found = ICS.UserDefined.FoundConversionFunction;
1311 ICS.setStandard();
1312 ICS.Standard.setAsIdentityConversion();
1313 ICS.Standard.setFromType(From->getType());
1314 ICS.Standard.setAllToTypes(ToType);
1315 ICS.Standard.CopyConstructor = Constructor;
1316 ICS.Standard.FoundCopyConstructor = Found;
1317 if (ToCanon != FromCanon)
1318 ICS.Standard.Second = ICK_Derived_To_Base;
1319 }
1320 }
1321 break;
1322
1323 case OR_Ambiguous:
1324 ICS.setAmbiguous();
1325 ICS.Ambiguous.setFromType(From->getType());
1326 ICS.Ambiguous.setToType(ToType);
1327 for (OverloadCandidateSet::iterator Cand = Conversions.begin();
1328 Cand != Conversions.end(); ++Cand)
1329 if (Cand->Best)
1330 ICS.Ambiguous.addConversion(Cand->FoundDecl, Cand->Function);
1331 break;
1332
1333 // Fall through.
1334 case OR_No_Viable_Function:
1335 ICS.setBad(BadConversionSequence::no_conversion, From, ToType);
1336 break;
1337 }
1338
1339 return ICS;
1340}
1341
1342/// TryImplicitConversion - Attempt to perform an implicit conversion
1343/// from the given expression (Expr) to the given type (ToType). This
1344/// function returns an implicit conversion sequence that can be used
1345/// to perform the initialization. Given
1346///
1347/// void f(float f);
1348/// void g(int i) { f(i); }
1349///
1350/// this routine would produce an implicit conversion sequence to
1351/// describe the initialization of f from i, which will be a standard
1352/// conversion sequence containing an lvalue-to-rvalue conversion (C++
1353/// 4.1) followed by a floating-integral conversion (C++ 4.9).
1354//
1355/// Note that this routine only determines how the conversion can be
1356/// performed; it does not actually perform the conversion. As such,
1357/// it will not produce any diagnostics if no conversion is available,
1358/// but will instead return an implicit conversion sequence of kind
1359/// "BadConversion".
1360///
1361/// If @p SuppressUserConversions, then user-defined conversions are
1362/// not permitted.
1363/// If @p AllowExplicit, then explicit user-defined conversions are
1364/// permitted.
1365///
1366/// \param AllowObjCWritebackConversion Whether we allow the Objective-C
1367/// writeback conversion, which allows __autoreleasing id* parameters to
1368/// be initialized with __strong id* or __weak id* arguments.
1369static ImplicitConversionSequence
1370TryImplicitConversion(Sema &S, Expr *From, QualType ToType,
1371 bool SuppressUserConversions,
1372 bool AllowExplicit,
1373 bool InOverloadResolution,
1374 bool CStyle,
1375 bool AllowObjCWritebackConversion,
1376 bool AllowObjCConversionOnExplicit) {
1377 ImplicitConversionSequence ICS;
1378 if (IsStandardConversion(S, From, ToType, InOverloadResolution,
1379 ICS.Standard, CStyle, AllowObjCWritebackConversion)){
1380 ICS.setStandard();
1381 return ICS;
1382 }
1383
1384 if (!S.getLangOpts().CPlusPlus) {
1385 ICS.setBad(BadConversionSequence::no_conversion, From, ToType);
1386 return ICS;
1387 }
1388
1389 // C++ [over.ics.user]p4:
1390 // A conversion of an expression of class type to the same class
1391 // type is given Exact Match rank, and a conversion of an
1392 // expression of class type to a base class of that type is
1393 // given Conversion rank, in spite of the fact that a copy/move
1394 // constructor (i.e., a user-defined conversion function) is
1395 // called for those cases.
1396 QualType FromType = From->getType();
1397 if (ToType->getAs<RecordType>() && FromType->getAs<RecordType>() &&
1398 (S.Context.hasSameUnqualifiedType(FromType, ToType) ||
1399 S.IsDerivedFrom(From->getBeginLoc(), FromType, ToType))) {
1400 ICS.setStandard();
1401 ICS.Standard.setAsIdentityConversion();
1402 ICS.Standard.setFromType(FromType);
1403 ICS.Standard.setAllToTypes(ToType);
1404
1405 // We don't actually check at this point whether there is a valid
1406 // copy/move constructor, since overloading just assumes that it
1407 // exists. When we actually perform initialization, we'll find the
1408 // appropriate constructor to copy the returned object, if needed.
1409 ICS.Standard.CopyConstructor = nullptr;
1410
1411 // Determine whether this is considered a derived-to-base conversion.
1412 if (!S.Context.hasSameUnqualifiedType(FromType, ToType))
1413 ICS.Standard.Second = ICK_Derived_To_Base;
1414
1415 return ICS;
1416 }
1417
1418 return TryUserDefinedConversion(S, From, ToType, SuppressUserConversions,
1419 AllowExplicit, InOverloadResolution, CStyle,
1420 AllowObjCWritebackConversion,
1421 AllowObjCConversionOnExplicit);
1422}
1423
1424ImplicitConversionSequence
1425Sema::TryImplicitConversion(Expr *From, QualType ToType,
1426 bool SuppressUserConversions,
1427 bool AllowExplicit,
1428 bool InOverloadResolution,
1429 bool CStyle,
1430 bool AllowObjCWritebackConversion) {
1431 return ::TryImplicitConversion(*this, From, ToType,
1432 SuppressUserConversions, AllowExplicit,
1433 InOverloadResolution, CStyle,
1434 AllowObjCWritebackConversion,
1435 /*AllowObjCConversionOnExplicit=*/false);
1436}
1437
1438/// PerformImplicitConversion - Perform an implicit conversion of the
1439/// expression From to the type ToType. Returns the
1440/// converted expression. Flavor is the kind of conversion we're
1441/// performing, used in the error message. If @p AllowExplicit,
1442/// explicit user-defined conversions are permitted.
1443ExprResult
1444Sema::PerformImplicitConversion(Expr *From, QualType ToType,
1445 AssignmentAction Action, bool AllowExplicit) {
1446 ImplicitConversionSequence ICS;
1447 return PerformImplicitConversion(From, ToType, Action, AllowExplicit, ICS);
1448}
1449
1450ExprResult
1451Sema::PerformImplicitConversion(Expr *From, QualType ToType,
1452 AssignmentAction Action, bool AllowExplicit,
1453 ImplicitConversionSequence& ICS) {
1454 if (checkPlaceholderForOverload(*this, From))
1455 return ExprError();
1456
1457 // Objective-C ARC: Determine whether we will allow the writeback conversion.
1458 bool AllowObjCWritebackConversion
1459 = getLangOpts().ObjCAutoRefCount &&
1460 (Action == AA_Passing || Action == AA_Sending);
1461 if (getLangOpts().ObjC)
1462 CheckObjCBridgeRelatedConversions(From->getBeginLoc(), ToType,
1463 From->getType(), From);
1464 ICS = ::TryImplicitConversion(*this, From, ToType,
1465 /*SuppressUserConversions=*/false,
1466 AllowExplicit,
1467 /*InOverloadResolution=*/false,
1468 /*CStyle=*/false,
1469 AllowObjCWritebackConversion,
1470 /*AllowObjCConversionOnExplicit=*/false);
1471 return PerformImplicitConversion(From, ToType, ICS, Action);
1472}
1473
1474/// Determine whether the conversion from FromType to ToType is a valid
1475/// conversion that strips "noexcept" or "noreturn" off the nested function
1476/// type.
1477bool Sema::IsFunctionConversion(QualType FromType, QualType ToType,
1478 QualType &ResultTy) {
1479 if (Context.hasSameUnqualifiedType(FromType, ToType))
1480 return false;
1481
1482 // Permit the conversion F(t __attribute__((noreturn))) -> F(t)
1483 // or F(t noexcept) -> F(t)
1484 // where F adds one of the following at most once:
1485 // - a pointer
1486 // - a member pointer
1487 // - a block pointer
1488 // Changes here need matching changes in FindCompositePointerType.
1489 CanQualType CanTo = Context.getCanonicalType(ToType);
1490 CanQualType CanFrom = Context.getCanonicalType(FromType);
1491 Type::TypeClass TyClass = CanTo->getTypeClass();
1492 if (TyClass != CanFrom->getTypeClass()) return false;
1493 if (TyClass != Type::FunctionProto && TyClass != Type::FunctionNoProto) {
1494 if (TyClass == Type::Pointer) {
1495 CanTo = CanTo.castAs<PointerType>()->getPointeeType();
1496 CanFrom = CanFrom.castAs<PointerType>()->getPointeeType();
1497 } else if (TyClass == Type::BlockPointer) {
1498 CanTo = CanTo.castAs<BlockPointerType>()->getPointeeType();
1499 CanFrom = CanFrom.castAs<BlockPointerType>()->getPointeeType();
1500 } else if (TyClass == Type::MemberPointer) {
1501 auto ToMPT = CanTo.castAs<MemberPointerType>();
1502 auto FromMPT = CanFrom.castAs<MemberPointerType>();
1503 // A function pointer conversion cannot change the class of the function.
1504 if (ToMPT->getClass() != FromMPT->getClass())
1505 return false;
1506 CanTo = ToMPT->getPointeeType();
1507 CanFrom = FromMPT->getPointeeType();
1508 } else {
1509 return false;
1510 }
1511
1512 TyClass = CanTo->getTypeClass();
1513 if (TyClass != CanFrom->getTypeClass()) return false;
1514 if (TyClass != Type::FunctionProto && TyClass != Type::FunctionNoProto)
1515 return false;
1516 }
1517
1518 const auto *FromFn = cast<FunctionType>(CanFrom);
1519 FunctionType::ExtInfo FromEInfo = FromFn->getExtInfo();
1520
1521 const auto *ToFn = cast<FunctionType>(CanTo);
1522 FunctionType::ExtInfo ToEInfo = ToFn->getExtInfo();
1523
1524 bool Changed = false;
1525
1526 // Drop 'noreturn' if not present in target type.
1527 if (FromEInfo.getNoReturn() && !ToEInfo.getNoReturn()) {
1528 FromFn = Context.adjustFunctionType(FromFn, FromEInfo.withNoReturn(false));
1529 Changed = true;
1530 }
1531
1532 // Drop 'noexcept' if not present in target type.
1533 if (const auto *FromFPT = dyn_cast<FunctionProtoType>(FromFn)) {
1534 const auto *ToFPT = cast<FunctionProtoType>(ToFn);
1535 if (FromFPT->isNothrow() && !ToFPT->isNothrow()) {
1536 FromFn = cast<FunctionType>(
1537 Context.getFunctionTypeWithExceptionSpec(QualType(FromFPT, 0),
1538 EST_None)
1539 .getTypePtr());
1540 Changed = true;
1541 }
1542
1543 // Convert FromFPT's ExtParameterInfo if necessary. The conversion is valid
1544 // only if the ExtParameterInfo lists of the two function prototypes can be
1545 // merged and the merged list is identical to ToFPT's ExtParameterInfo list.
1546 SmallVector<FunctionProtoType::ExtParameterInfo, 4> NewParamInfos;
1547 bool CanUseToFPT, CanUseFromFPT;
1548 if (Context.mergeExtParameterInfo(ToFPT, FromFPT, CanUseToFPT,
1549 CanUseFromFPT, NewParamInfos) &&
1550 CanUseToFPT && !CanUseFromFPT) {
1551 FunctionProtoType::ExtProtoInfo ExtInfo = FromFPT->getExtProtoInfo();
1552 ExtInfo.ExtParameterInfos =
1553 NewParamInfos.empty() ? nullptr : NewParamInfos.data();
1554 QualType QT = Context.getFunctionType(FromFPT->getReturnType(),
1555 FromFPT->getParamTypes(), ExtInfo);
1556 FromFn = QT->getAs<FunctionType>();
1557 Changed = true;
1558 }
1559 }
1560
1561 if (!Changed)
1562 return false;
1563
1564 assert(QualType(FromFn, 0).isCanonical())((QualType(FromFn, 0).isCanonical()) ? static_cast<void>
(0) : __assert_fail ("QualType(FromFn, 0).isCanonical()", "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaOverload.cpp"
, 1564, __PRETTY_FUNCTION__))
;
1565 if (QualType(FromFn, 0) != CanTo) return false;
1566
1567 ResultTy = ToType;
1568 return true;
1569}
1570
1571/// Determine whether the conversion from FromType to ToType is a valid
1572/// vector conversion.
1573///
1574/// \param ICK Will be set to the vector conversion kind, if this is a vector
1575/// conversion.
1576static bool IsVectorConversion(Sema &S, QualType FromType,
1577 QualType ToType, ImplicitConversionKind &ICK) {
1578 // We need at least one of these types to be a vector type to have a vector
1579 // conversion.
1580 if (!ToType->isVectorType() && !FromType->isVectorType())
1581 return false;
1582
1583 // Identical types require no conversions.
1584 if (S.Context.hasSameUnqualifiedType(FromType, ToType))
1585 return false;
1586
1587 // There are no conversions between extended vector types, only identity.
1588 if (ToType->isExtVectorType()) {
1589 // There are no conversions between extended vector types other than the
1590 // identity conversion.
1591 if (FromType->isExtVectorType())
1592 return false;
1593
1594 // Vector splat from any arithmetic type to a vector.
1595 if (FromType->isArithmeticType()) {
1596 ICK = ICK_Vector_Splat;
1597 return true;
1598 }
1599 }
1600
1601 // We can perform the conversion between vector types in the following cases:
1602 // 1)vector types are equivalent AltiVec and GCC vector types
1603 // 2)lax vector conversions are permitted and the vector types are of the
1604 // same size
1605 if (ToType->isVectorType() && FromType->isVectorType()) {
1606 if (S.Context.areCompatibleVectorTypes(FromType, ToType) ||
1607 S.isLaxVectorConversion(FromType, ToType)) {
1608 ICK = ICK_Vector_Conversion;
1609 return true;
1610 }
1611 }
1612
1613 return false;
1614}
1615
1616static bool tryAtomicConversion(Sema &S, Expr *From, QualType ToType,
1617 bool InOverloadResolution,
1618 StandardConversionSequence &SCS,
1619 bool CStyle);
1620
1621/// IsStandardConversion - Determines whether there is a standard
1622/// conversion sequence (C++ [conv], C++ [over.ics.scs]) from the
1623/// expression From to the type ToType. Standard conversion sequences
1624/// only consider non-class types; for conversions that involve class
1625/// types, use TryImplicitConversion. If a conversion exists, SCS will
1626/// contain the standard conversion sequence required to perform this
1627/// conversion and this routine will return true. Otherwise, this
1628/// routine will return false and the value of SCS is unspecified.
1629static bool IsStandardConversion(Sema &S, Expr* From, QualType ToType,
1630 bool InOverloadResolution,
1631 StandardConversionSequence &SCS,
1632 bool CStyle,
1633 bool AllowObjCWritebackConversion) {
1634 QualType FromType = From->getType();
1635
1636 // Standard conversions (C++ [conv])
1637 SCS.setAsIdentityConversion();
1638 SCS.IncompatibleObjC = false;
1639 SCS.setFromType(FromType);
1640 SCS.CopyConstructor = nullptr;
1641
1642 // There are no standard conversions for class types in C++, so
1643 // abort early. When overloading in C, however, we do permit them.
1644 if (S.getLangOpts().CPlusPlus &&
1645 (FromType->isRecordType() || ToType->isRecordType()))
1646 return false;
1647
1648 // The first conversion can be an lvalue-to-rvalue conversion,
1649 // array-to-pointer conversion, or function-to-pointer conversion
1650 // (C++ 4p1).
1651
1652 if (FromType == S.Context.OverloadTy) {
1653 DeclAccessPair AccessPair;
1654 if (FunctionDecl *Fn
1655 = S.ResolveAddressOfOverloadedFunction(From, ToType, false,
1656 AccessPair)) {
1657 // We were able to resolve the address of the overloaded function,
1658 // so we can convert to the type of that function.
1659 FromType = Fn->getType();
1660 SCS.setFromType(FromType);
1661
1662 // we can sometimes resolve &foo<int> regardless of ToType, so check
1663 // if the type matches (identity) or we are converting to bool
1664 if (!S.Context.hasSameUnqualifiedType(
1665 S.ExtractUnqualifiedFunctionType(ToType), FromType)) {
1666 QualType resultTy;
1667 // if the function type matches except for [[noreturn]], it's ok
1668 if (!S.IsFunctionConversion(FromType,
1669 S.ExtractUnqualifiedFunctionType(ToType), resultTy))
1670 // otherwise, only a boolean conversion is standard
1671 if (!ToType->isBooleanType())
1672 return false;
1673 }
1674
1675 // Check if the "from" expression is taking the address of an overloaded
1676 // function and recompute the FromType accordingly. Take advantage of the
1677 // fact that non-static member functions *must* have such an address-of
1678 // expression.
1679 CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn);
1680 if (Method && !Method->isStatic()) {
1681 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-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaOverload.cpp"
, 1682, __PRETTY_FUNCTION__))
1682 "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-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaOverload.cpp"
, 1682, __PRETTY_FUNCTION__))
;
1683 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-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaOverload.cpp"
, 1685, __PRETTY_FUNCTION__))
1684 == 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-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaOverload.cpp"
, 1685, __PRETTY_FUNCTION__))
1685 "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-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaOverload.cpp"
, 1685, __PRETTY_FUNCTION__))
;
1686 const Type *ClassType
1687 = S.Context.getTypeDeclType(Method->getParent()).getTypePtr();
1688 FromType = S.Context.getMemberPointerType(FromType, ClassType);
1689 } else if (isa<UnaryOperator>(From->IgnoreParens())) {
1690 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-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaOverload.cpp"
, 1692, __PRETTY_FUNCTION__))
1691 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-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaOverload.cpp"
, 1692, __PRETTY_FUNCTION__))
1692 "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-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaOverload.cpp"
, 1692, __PRETTY_FUNCTION__))
;
1693 FromType = S.Context.getPointerType(FromType);
1694 }
1695
1696 // Check that we've computed the proper type after overload resolution.
1697 // FIXME: FixOverloadedFunctionReference has side-effects; we shouldn't
1698 // be calling it from within an NDEBUG block.
1699 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-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaOverload.cpp"
, 1701, __PRETTY_FUNCTION__))
1700 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-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaOverload.cpp"
, 1701, __PRETTY_FUNCTION__))
1701 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-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaOverload.cpp"
, 1701, __PRETTY_FUNCTION__))
;
1702 } else {
1703 return false;
1704 }
1705 }
1706 // Lvalue-to-rvalue conversion (C++11 4.1):
1707 // A glvalue (3.10) of a non-function, non-array type T can
1708 // be converted to a prvalue.
1709 bool argIsLValue = From->isGLValue();
1710 if (argIsLValue &&
1711 !FromType->isFunctionType() && !FromType->isArrayType() &&
1712 S.Context.getCanonicalType(FromType) != S.Context.OverloadTy) {
1713 SCS.First = ICK_Lvalue_To_Rvalue;
1714
1715 // C11 6.3.2.1p2:
1716 // ... if the lvalue has atomic type, the value has the non-atomic version
1717 // of the type of the lvalue ...
1718 if (const AtomicType *Atomic = FromType->getAs<AtomicType>())
1719 FromType = Atomic->getValueType();
1720
1721 // If T is a non-class type, the type of the rvalue is the
1722 // cv-unqualified version of T. Otherwise, the type of the rvalue
1723 // is T (C++ 4.1p1). C++ can't get here with class types; in C, we
1724 // just strip the qualifiers because they don't matter.
1725 FromType = FromType.getUnqualifiedType();
1726 } else if (FromType->isArrayType()) {
1727 // Array-to-pointer conversion (C++ 4.2)
1728 SCS.First = ICK_Array_To_Pointer;
1729
1730 // An lvalue or rvalue of type "array of N T" or "array of unknown
1731 // bound of T" can be converted to an rvalue of type "pointer to
1732 // T" (C++ 4.2p1).
1733 FromType = S.Context.getArrayDecayedType(FromType);
1734
1735 if (S.IsStringLiteralToNonConstPointerConversion(From, ToType)) {
1736 // This conversion is deprecated in C++03 (D.4)
1737 SCS.DeprecatedStringLiteralToCharPtr = true;
1738
1739 // For the purpose of ranking in overload resolution
1740 // (13.3.3.1.1), this conversion is considered an
1741 // array-to-pointer conversion followed by a qualification
1742 // conversion (4.4). (C++ 4.2p2)
1743 SCS.Second = ICK_Identity;
1744 SCS.Third = ICK_Qualification;
1745 SCS.QualificationIncludesObjCLifetime = false;
1746 SCS.setAllToTypes(FromType);
1747 return true;
1748 }
1749 } else if (FromType->isFunctionType() && argIsLValue) {
1750 // Function-to-pointer conversion (C++ 4.3).
1751 SCS.First = ICK_Function_To_Pointer;
1752
1753 if (auto *DRE = dyn_cast<DeclRefExpr>(From->IgnoreParenCasts()))
1754 if (auto *FD = dyn_cast<FunctionDecl>(DRE->getDecl()))
1755 if (!S.checkAddressOfFunctionIsAvailable(FD))
1756 return false;
1757
1758 // An lvalue of function type T can be converted to an rvalue of
1759 // type "pointer to T." The result is a pointer to the
1760 // function. (C++ 4.3p1).
1761 FromType = S.Context.getPointerType(FromType);
1762 } else {
1763 // We don't require any conversions for the first step.
1764 SCS.First = ICK_Identity;
1765 }
1766 SCS.setToType(0, FromType);
1767
1768 // The second conversion can be an integral promotion, floating
1769 // point promotion, integral conversion, floating point conversion,
1770 // floating-integral conversion, pointer conversion,
1771 // pointer-to-member conversion, or boolean conversion (C++ 4p1).
1772 // For overloading in C, this can also be a "compatible-type"
1773 // conversion.
1774 bool IncompatibleObjC = false;
1775 ImplicitConversionKind SecondICK = ICK_Identity;
1776 if (S.Context.hasSameUnqualifiedType(FromType, ToType)) {
1777 // The unqualified versions of the types are the same: there's no
1778 // conversion to do.
1779 SCS.Second = ICK_Identity;
1780 } else if (S.IsIntegralPromotion(From, FromType, ToType)) {
1781 // Integral promotion (C++ 4.5).
1782 SCS.Second = ICK_Integral_Promotion;
1783 FromType = ToType.getUnqualifiedType();
1784 } else if (S.IsFloatingPointPromotion(FromType, ToType)) {
1785 // Floating point promotion (C++ 4.6).
1786 SCS.Second = ICK_Floating_Promotion;
1787 FromType = ToType.getUnqualifiedType();
1788 } else if (S.IsComplexPromotion(FromType, ToType)) {
1789 // Complex promotion (Clang extension)
1790 SCS.Second = ICK_Complex_Promotion;
1791 FromType = ToType.getUnqualifiedType();
1792 } else if (ToType->isBooleanType() &&
1793 (FromType->isArithmeticType() ||
1794 FromType->isAnyPointerType() ||
1795 FromType->isBlockPointerType() ||
1796 FromType->isMemberPointerType() ||
1797 FromType->isNullPtrType())) {
1798 // Boolean conversions (C++ 4.12).
1799 SCS.Second = ICK_Boolean_Conversion;
1800 FromType = S.Context.BoolTy;
1801 } else if (FromType->isIntegralOrUnscopedEnumerationType() &&
1802 ToType->isIntegralType(S.Context)) {
1803 // Integral conversions (C++ 4.7).
1804 SCS.Second = ICK_Integral_Conversion;
1805 FromType = ToType.getUnqualifiedType();
1806 } else if (FromType->isAnyComplexType() && ToType->isAnyComplexType()) {
1807 // Complex conversions (C99 6.3.1.6)
1808 SCS.Second = ICK_Complex_Conversion;
1809 FromType = ToType.getUnqualifiedType();
1810 } else if ((FromType->isAnyComplexType() && ToType->isArithmeticType()) ||
1811 (ToType->isAnyComplexType() && FromType->isArithmeticType())) {
1812 // Complex-real conversions (C99 6.3.1.7)
1813 SCS.Second = ICK_Complex_Real;
1814 FromType = ToType.getUnqualifiedType();
1815 } else if (FromType->isRealFloatingType() && ToType->isRealFloatingType()) {
1816 // FIXME: disable conversions between long double and __float128 if
1817 // their representation is different until there is back end support
1818 // We of course allow this conversion if long double is really double.
1819 if (&S.Context.getFloatTypeSemantics(FromType) !=
1820 &S.Context.getFloatTypeSemantics(ToType)) {
1821 bool Float128AndLongDouble = ((FromType == S.Context.Float128Ty &&
1822 ToType == S.Context.LongDoubleTy) ||
1823 (FromType == S.Context.LongDoubleTy &&
1824 ToType == S.Context.Float128Ty));
1825 if (Float128AndLongDouble &&
1826 (&S.Context.getFloatTypeSemantics(S.Context.LongDoubleTy) ==
1827 &llvm::APFloat::PPCDoubleDouble()))
1828 return false;
1829 }
1830 // Floating point conversions (C++ 4.8).
1831 SCS.Second = ICK_Floating_Conversion;
1832 FromType = ToType.getUnqualifiedType();
1833 } else if ((FromType->isRealFloatingType() &&
1834 ToType->isIntegralType(S.Context)) ||
1835 (FromType->isIntegralOrUnscopedEnumerationType() &&
1836 ToType->isRealFloatingType())) {
1837 // Floating-integral conversions (C++ 4.9).
1838 SCS.Second = ICK_Floating_Integral;
1839 FromType = ToType.getUnqualifiedType();
1840 } else if (S.IsBlockPointerConversion(FromType, ToType, FromType)) {
1841 SCS.Second = ICK_Block_Pointer_Conversion;
1842 } else if (AllowObjCWritebackConversion &&
1843 S.isObjCWritebackConversion(FromType, ToType, FromType)) {
1844 SCS.Second = ICK_Writeback_Conversion;
1845 } else if (S.IsPointerConversion(From, FromType, ToType, InOverloadResolution,
1846 FromType, IncompatibleObjC)) {
1847 // Pointer conversions (C++ 4.10).
1848 SCS.Second = ICK_Pointer_Conversion;
1849 SCS.IncompatibleObjC = IncompatibleObjC;
1850 FromType = FromType.getUnqualifiedType();
1851 } else if (S.IsMemberPointerConversion(From, FromType, ToType,
1852 InOverloadResolution, FromType)) {
1853 // Pointer to member conversions (4.11).
1854 SCS.Second = ICK_Pointer_Member;
1855 } else if (IsVectorConversion(S, FromType, ToType, SecondICK)) {
1856 SCS.Second = SecondICK;
1857 FromType = ToType.getUnqualifiedType();
1858 } else if (!S.getLangOpts().CPlusPlus &&
1859 S.Context.typesAreCompatible(ToType, FromType)) {
1860 // Compatible conversions (Clang extension for C function overloading)
1861 SCS.Second = ICK_Compatible_Conversion;
1862 FromType = ToType.getUnqualifiedType();
1863 } else if (IsTransparentUnionStandardConversion(S, From, ToType,
1864 InOverloadResolution,
1865 SCS, CStyle)) {
1866 SCS.Second = ICK_TransparentUnionConversion;
1867 FromType = ToType;
1868 } else if (tryAtomicConversion(S, From, ToType, InOverloadResolution, SCS,
1869 CStyle)) {
1870 // tryAtomicConversion has updated the standard conversion sequence
1871 // appropriately.
1872 return true;
1873 } else if (ToType->isEventT() &&
1874 From->isIntegerConstantExpr(S.getASTContext()) &&
1875 From->EvaluateKnownConstInt(S.getASTContext()) == 0) {
1876 SCS.Second = ICK_Zero_Event_Conversion;
1877 FromType = ToType;
1878 } else if (ToType->isQueueT() &&
1879 From->isIntegerConstantExpr(S.getASTContext()) &&
1880 (From->EvaluateKnownConstInt(S.getASTContext()) == 0)) {
1881 SCS.Second = ICK_Zero_Queue_Conversion;
1882 FromType = ToType;
1883 } else if (ToType->isSamplerT() &&
1884 From->isIntegerConstantExpr(S.getASTContext())) {
1885 SCS.Second = ICK_Compatible_Conversion;
1886 FromType = ToType;
1887 } else {
1888 // No second conversion required.
1889 SCS.Second = ICK_Identity;
1890 }
1891 SCS.setToType(1, FromType);
1892
1893 // The third conversion can be a function pointer conversion or a
1894 // qualification conversion (C++ [conv.fctptr], [conv.qual]).
1895 bool ObjCLifetimeConversion;
1896 if (S.IsFunctionConversion(FromType, ToType, FromType)) {
1897 // Function pointer conversions (removing 'noexcept') including removal of
1898 // 'noreturn' (Clang extension).
1899 SCS.Third = ICK_Function_Conversion;
1900 } else if (S.IsQualificationConversion(FromType, ToType, CStyle,
1901 ObjCLifetimeConversion)) {
1902 SCS.Third = ICK_Qualification;
1903 SCS.QualificationIncludesObjCLifetime = ObjCLifetimeConversion;
1904 FromType = ToType;
1905 } else {
1906 // No conversion required
1907 SCS.Third = ICK_Identity;
1908 }
1909
1910 // C++ [over.best.ics]p6:
1911 // [...] Any difference in top-level cv-qualification is
1912 // subsumed by the initialization itself and does not constitute
1913 // a conversion. [...]
1914 QualType CanonFrom = S.Context.getCanonicalType(FromType);
1915 QualType CanonTo = S.Context.getCanonicalType(ToType);
1916 if (CanonFrom.getLocalUnqualifiedType()
1917 == CanonTo.getLocalUnqualifiedType() &&
1918 CanonFrom.getLocalQualifiers() != CanonTo.getLocalQualifiers()) {
1919 FromType = ToType;
1920 CanonFrom = CanonTo;
1921 }
1922
1923 SCS.setToType(2, FromType);
1924
1925 if (CanonFrom == CanonTo)
1926 return true;
1927
1928 // If we have not converted the argument type to the parameter type,
1929 // this is a bad conversion sequence, unless we're resolving an overload in C.
1930 if (S.getLangOpts().CPlusPlus || !InOverloadResolution)
1931 return false;
1932
1933 ExprResult ER = ExprResult{From};
1934 Sema::AssignConvertType Conv =
1935 S.CheckSingleAssignmentConstraints(ToType, ER,
1936 /*Diagnose=*/false,
1937 /*DiagnoseCFAudited=*/false,
1938 /*ConvertRHS=*/false);
1939 ImplicitConversionKind SecondConv;
1940 switch (Conv) {
1941 case Sema::Compatible:
1942 SecondConv = ICK_C_Only_Conversion;
1943 break;
1944 // For our purposes, discarding qualifiers is just as bad as using an
1945 // incompatible pointer. Note that an IncompatiblePointer conversion can drop
1946 // qualifiers, as well.
1947 case Sema::CompatiblePointerDiscardsQualifiers:
1948 case Sema::IncompatiblePointer:
1949 case Sema::IncompatiblePointerSign:
1950 SecondConv = ICK_Incompatible_Pointer_Conversion;
1951 break;
1952 default:
1953 return false;
1954 }
1955
1956 // First can only be an lvalue conversion, so we pretend that this was the
1957 // second conversion. First should already be valid from earlier in the
1958 // function.
1959 SCS.Second = SecondConv;
1960 SCS.setToType(1, ToType);
1961
1962 // Third is Identity, because Second should rank us worse than any other
1963 // conversion. This could also be ICK_Qualification, but it's simpler to just
1964 // lump everything in with the second conversion, and we don't gain anything
1965 // from making this ICK_Qualification.
1966 SCS.Third = ICK_Identity;
1967 SCS.setToType(2, ToType);
1968 return true;
1969}
1970
1971static bool
1972IsTransparentUnionStandardConversion(Sema &S, Expr* From,
1973 QualType &ToType,
1974 bool InOverloadResolution,
1975 StandardConversionSequence &SCS,
1976 bool CStyle) {
1977
1978 const RecordType *UT = ToType->getAsUnionType();
1979 if (!UT || !UT->getDecl()->hasAttr<TransparentUnionAttr>())
1980 return false;
1981 // The field to initialize within the transparent union.
1982 RecordDecl *UD = UT->getDecl();
1983 // It's compatible if the expression matches any of the fields.
1984 for (const auto *it : UD->fields()) {
1985 if (IsStandardConversion(S, From, it->getType(), InOverloadResolution, SCS,
1986 CStyle, /*AllowObjCWritebackConversion=*/false)) {
1987 ToType = it->getType();
1988 return true;
1989 }
1990 }
1991 return false;
1992}
1993
1994/// IsIntegralPromotion - Determines whether the conversion from the
1995/// expression From (whose potentially-adjusted type is FromType) to
1996/// ToType is an integral promotion (C++ 4.5). If so, returns true and
1997/// sets PromotedType to the promoted type.
1998bool Sema::IsIntegralPromotion(Expr *From, QualType FromType, QualType ToType) {
1999 const BuiltinType *To = ToType->getAs<BuiltinType>();
2000 // All integers are built-in.
2001 if (!To) {
2002 return false;
2003 }
2004
2005 // An rvalue of type char, signed char, unsigned char, short int, or
2006 // unsigned short int can be converted to an rvalue of type int if
2007 // int can represent all the values of the source type; otherwise,
2008 // the source rvalue can be converted to an rvalue of type unsigned
2009 // int (C++ 4.5p1).
2010 if (FromType->isPromotableIntegerType() && !FromType->isBooleanType() &&
2011 !FromType->isEnumeralType()) {
2012 if (// We can promote any signed, promotable integer type to an int
2013 (FromType->isSignedIntegerType() ||
2014 // We can promote any unsigned integer type whose size is
2015 // less than int to an int.
2016 Context.getTypeSize(FromType) < Context.getTypeSize(ToType))) {
2017 return To->getKind() == BuiltinType::Int;
2018 }
2019
2020 return To->getKind() == BuiltinType::UInt;
2021 }
2022
2023 // C++11 [conv.prom]p3:
2024 // A prvalue of an unscoped enumeration type whose underlying type is not
2025 // fixed (7.2) can be converted to an rvalue a prvalue of the first of the
2026 // following types that can represent all the values of the enumeration
2027 // (i.e., the values in the range bmin to bmax as described in 7.2): int,
2028 // unsigned int, long int, unsigned long int, long long int, or unsigned
2029 // long long int. If none of the types in that list can represent all the
2030 // values of the enumeration, an rvalue a prvalue of an unscoped enumeration
2031 // type can be converted to an rvalue a prvalue of the extended integer type
2032 // with lowest integer conversion rank (4.13) greater than the rank of long
2033 // long in which all the values of the enumeration can be represented. If
2034 // there are two such extended types, the signed one is chosen.
2035 // C++11 [conv.prom]p4:
2036 // A prvalue of an unscoped enumeration type whose underlying type is fixed
2037 // can be converted to a prvalue of its underlying type. Moreover, if
2038 // integral promotion can be applied to its underlying type, a prvalue of an
2039 // unscoped enumeration type whose underlying type is fixed can also be
2040 // converted to a prvalue of the promoted underlying type.
2041 if (const EnumType *FromEnumType = FromType->getAs<EnumType>()) {
2042 // C++0x 7.2p9: Note that this implicit enum to int conversion is not
2043 // provided for a scoped enumeration.
2044 if (FromEnumType->getDecl()->isScoped())
2045 return false;
2046
2047 // We can perform an integral promotion to the underlying type of the enum,
2048 // even if that's not the promoted type. Note that the check for promoting
2049 // the underlying type is based on the type alone, and does not consider
2050 // the bitfield-ness of the actual source expression.
2051 if (FromEnumType->getDecl()->isFixed()) {
2052 QualType Underlying = FromEnumType->getDecl()->getIntegerType();
2053 return Context.hasSameUnqualifiedType(Underlying, ToType) ||
2054 IsIntegralPromotion(nullptr, Underlying, ToType);
2055 }
2056
2057 // We have already pre-calculated the promotion type, so this is trivial.
2058 if (ToType->isIntegerType() &&
2059 isCompleteType(From->getBeginLoc(), FromType))
2060 return Context.hasSameUnqualifiedType(
2061 ToType, FromEnumType->getDecl()->getPromotionType());
2062
2063 // C++ [conv.prom]p5:
2064 // If the bit-field has an enumerated type, it is treated as any other
2065 // value of that type for promotion purposes.
2066 //
2067 // ... so do not fall through into the bit-field checks below in C++.
2068 if (getLangOpts().CPlusPlus)
2069 return false;
2070 }
2071
2072 // C++0x [conv.prom]p2:
2073 // A prvalue of type char16_t, char32_t, or wchar_t (3.9.1) can be converted
2074 // to an rvalue a prvalue of the first of the following types that can
2075 // represent all the values of its underlying type: int, unsigned int,
2076 // long int, unsigned long int, long long int, or unsigned long long int.
2077 // If none of the types in that list can represent all the values of its
2078 // underlying type, an rvalue a prvalue of type char16_t, char32_t,
2079 // or wchar_t can be converted to an rvalue a prvalue of its underlying
2080 // type.
2081 if (FromType->isAnyCharacterType() && !FromType->isCharType() &&
2082 ToType->isIntegerType()) {
2083 // Determine whether the type we're converting from is signed or
2084 // unsigned.
2085 bool FromIsSigned = FromType->isSignedIntegerType();
2086 uint64_t FromSize = Context.getTypeSize(FromType);
2087
2088 // The types we'll try to promote to, in the appropriate
2089 // order. Try each of these types.
2090 QualType PromoteTypes[6] = {
2091 Context.IntTy, Context.UnsignedIntTy,
2092 Context.LongTy, Context.UnsignedLongTy ,
2093 Context.LongLongTy, Context.UnsignedLongLongTy
2094 };
2095 for (int Idx = 0; Idx < 6; ++Idx) {
2096 uint64_t ToSize = Context.getTypeSize(PromoteTypes[Idx]);
2097 if (FromSize < ToSize ||
2098 (FromSize == ToSize &&
2099 FromIsSigned == PromoteTypes[Idx]->isSignedIntegerType())) {
2100 // We found the type that we can promote to. If this is the
2101 // type we wanted, we have a promotion. Otherwise, no
2102 // promotion.
2103 return Context.hasSameUnqualifiedType(ToType, PromoteTypes[Idx]);
2104 }
2105 }
2106 }
2107
2108 // An rvalue for an integral bit-field (9.6) can be converted to an
2109 // rvalue of type int if int can represent all the values of the
2110 // bit-field; otherwise, it can be converted to unsigned int if
2111 // unsigned int can represent all the values of the bit-field. If
2112 // the bit-field is larger yet, no integral promotion applies to
2113 // it. If the bit-field has an enumerated type, it is treated as any
2114 // other value of that type for promotion purposes (C++ 4.5p3).
2115 // FIXME: We should delay checking of bit-fields until we actually perform the
2116 // conversion.
2117 //
2118 // FIXME: In C, only bit-fields of types _Bool, int, or unsigned int may be
2119 // promoted, per C11 6.3.1.1/2. We promote all bit-fields (including enum
2120 // bit-fields and those whose underlying type is larger than int) for GCC
2121 // compatibility.
2122 if (From) {
2123 if (FieldDecl *MemberDecl = From->getSourceBitField()) {
2124 llvm::APSInt BitWidth;
2125 if (FromType->isIntegralType(Context) &&
2126 MemberDecl->getBitWidth()->isIntegerConstantExpr(BitWidth, Context)) {
2127 llvm::APSInt ToSize(BitWidth.getBitWidth(), BitWidth.isUnsigned());
2128 ToSize = Context.getTypeSize(ToType);
2129
2130 // Are we promoting to an int from a bitfield that fits in an int?
2131 if (BitWidth < ToSize ||
2132 (FromType->isSignedIntegerType() && BitWidth <= ToSize)) {
2133 return To->getKind() == BuiltinType::Int;
2134 }
2135
2136 // Are we promoting to an unsigned int from an unsigned bitfield
2137 // that fits into an unsigned int?
2138 if (FromType->isUnsignedIntegerType() && BitWidth <= ToSize) {
2139 return To->getKind() == BuiltinType::UInt;
2140 }
2141
2142 return false;
2143 }
2144 }
2145 }
2146
2147 // An rvalue of type bool can be converted to an rvalue of type int,
2148 // with false becoming zero and true becoming one (C++ 4.5p4).
2149 if (FromType->isBooleanType() && To->getKind() == BuiltinType::Int) {
2150 return true;
2151 }
2152
2153 return false;
2154}
2155
2156/// IsFloatingPointPromotion - Determines whether the conversion from
2157/// FromType to ToType is a floating point promotion (C++ 4.6). If so,
2158/// returns true and sets PromotedType to the promoted type.
2159bool Sema::IsFloatingPointPromotion(QualType FromType, QualType ToType) {
2160 if (const BuiltinType *FromBuiltin = FromType->getAs<BuiltinType>())
2161 if (const BuiltinType *ToBuiltin = ToType->getAs<BuiltinType>()) {
2162 /// An rvalue of type float can be converted to an rvalue of type
2163 /// double. (C++ 4.6p1).
2164 if (FromBuiltin->getKind() == BuiltinType::Float &&
2165 ToBuiltin->getKind() == BuiltinType::Double)
2166 return true;
2167
2168 // C99 6.3.1.5p1:
2169 // When a float is promoted to double or long double, or a
2170 // double is promoted to long double [...].
2171 if (!getLangOpts().CPlusPlus &&
2172 (FromBuiltin->getKind() == BuiltinType::Float ||
2173 FromBuiltin->getKind() == BuiltinType::Double) &&
2174 (ToBuiltin->getKind() == BuiltinType::LongDouble ||
2175 ToBuiltin->getKind() == BuiltinType::Float128))
2176 return true;
2177
2178 // Half can be promoted to float.
2179 if (!getLangOpts().NativeHalfType &&
2180 FromBuiltin->getKind() == BuiltinType::Half &&
2181 ToBuiltin->getKind() == BuiltinType::Float)
2182 return true;
2183 }
2184
2185 return false;
2186}
2187
2188/// Determine if a conversion is a complex promotion.
2189///
2190/// A complex promotion is defined as a complex -> complex conversion
2191/// where the conversion between the underlying real types is a
2192/// floating-point or integral promotion.
2193bool Sema::IsComplexPromotion(QualType FromType, QualType ToType) {
2194 const ComplexType *FromComplex = FromType->getAs<ComplexType>();
2195 if (!FromComplex)
2196 return false;
2197
2198 const ComplexType *ToComplex = ToType->getAs<ComplexType>();
2199 if (!ToComplex)
2200 return false;
2201
2202 return IsFloatingPointPromotion(FromComplex->getElementType(),
2203 ToComplex->getElementType()) ||
2204 IsIntegralPromotion(nullptr, FromComplex->getElementType(),
2205 ToComplex->getElementType());
2206}
2207
2208/// BuildSimilarlyQualifiedPointerType - In a pointer conversion from
2209/// the pointer type FromPtr to a pointer to type ToPointee, with the
2210/// same type qualifiers as FromPtr has on its pointee type. ToType,
2211/// if non-empty, will be a pointer to ToType that may or may not have
2212/// the right set of qualifiers on its pointee.
2213///
2214static QualType
2215BuildSimilarlyQualifiedPointerType(const Type *FromPtr,
2216 QualType ToPointee, QualType ToType,
2217 ASTContext &Context,
2218 bool StripObjCLifetime = false) {
2219 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-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaOverload.cpp"
, 2221, __PRETTY_FUNCTION__))
2220 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-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaOverload.cpp"
, 2221, __PRETTY_FUNCTION__))
2221 "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-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaOverload.cpp"
, 2221, __PRETTY_FUNCTION__))
;
2222
2223 /// Conversions to 'id' subsume cv-qualifier conversions.
2224 if (ToType->isObjCIdType() || ToType->isObjCQualifiedIdType())
2225 return ToType.getUnqualifiedType();
2226
2227 QualType CanonFromPointee
2228 = Context.getCanonicalType(FromPtr->getPointeeType());
2229 QualType CanonToPointee = Context.getCanonicalType(ToPointee);
2230 Qualifiers Quals = CanonFromPointee.getQualifiers();
2231
2232 if (StripObjCLifetime)
2233 Quals.removeObjCLifetime();
2234
2235 // Exact qualifier match -> return the pointer type we're converting to.
2236 if (CanonToPointee.getLocalQualifiers() == Quals) {
2237 // ToType is exactly what we need. Return it.
2238 if (!ToType.isNull())
2239 return ToType.getUnqualifiedType();
2240
2241 // Build a pointer to ToPointee. It has the right qualifiers
2242 // already.
2243 if (isa<ObjCObjectPointerType>(ToType))
2244 return Context.getObjCObjectPointerType(ToPointee);
2245 return Context.getPointerType(ToPointee);
2246 }
2247
2248 // Just build a canonical type that has the right qualifiers.
2249 QualType QualifiedCanonToPointee
2250 = Context.getQualifiedType(CanonToPointee.getLocalUnqualifiedType(), Quals);
2251
2252 if (isa<ObjCObjectPointerType>(ToType))
2253 return Context.getObjCObjectPointerType(QualifiedCanonToPointee);
2254 return Context.getPointerType(QualifiedCanonToPointee);
2255}
2256
2257static bool isNullPointerConstantForConversion(Expr *Expr,
2258 bool InOverloadResolution,
2259 ASTContext &Context) {
2260 // Handle value-dependent integral null pointer constants correctly.
2261 // http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#903
2262 if (Expr->isValueDependent() && !Expr->isTypeDependent() &&
2263 Expr->getType()->isIntegerType() && !Expr->getType()->isEnumeralType())
2264 return !InOverloadResolution;
2265
2266 return Expr->isNullPointerConstant(Context,
2267 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull
2268 : Expr::NPC_ValueDependentIsNull);
2269}
2270
2271/// IsPointerConversion - Determines whether the conversion of the
2272/// expression From, which has the (possibly adjusted) type FromType,
2273/// can be converted to the type ToType via a pointer conversion (C++
2274/// 4.10). If so, returns true and places the converted type (that
2275/// might differ from ToType in its cv-qualifiers at some level) into
2276/// ConvertedType.
2277///
2278/// This routine also supports conversions to and from block pointers
2279/// and conversions with Objective-C's 'id', 'id<protocols...>', and
2280/// pointers to interfaces. FIXME: Once we've determined the
2281/// appropriate overloading rules for Objective-C, we may want to
2282/// split the Objective-C checks into a different routine; however,
2283/// GCC seems to consider all of these conversions to be pointer
2284/// conversions, so for now they live here. IncompatibleObjC will be
2285/// set if the conversion is an allowed Objective-C conversion that
2286/// should result in a warning.
2287bool Sema::IsPointerConversion(Expr *From, QualType FromType, QualType ToType,
2288 bool InOverloadResolution,
2289 QualType& ConvertedType,
2290 bool &IncompatibleObjC) {
2291 IncompatibleObjC = false;
2292 if (isObjCPointerConversion(FromType, ToType, ConvertedType,
2293 IncompatibleObjC))
2294 return true;
2295
2296 // Conversion from a null pointer constant to any Objective-C pointer type.
2297 if (ToType->isObjCObjectPointerType() &&
2298 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) {
2299 ConvertedType = ToType;
2300 return true;
2301 }
2302
2303 // Blocks: Block pointers can be converted to void*.
2304 if (FromType->isBlockPointerType() && ToType->isPointerType() &&
2305 ToType->castAs<PointerType>()->getPointeeType()->isVoidType()) {
2306 ConvertedType = ToType;
2307 return true;
2308 }
2309 // Blocks: A null pointer constant can be converted to a block
2310 // pointer type.
2311 if (ToType->isBlockPointerType() &&
2312 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) {
2313 ConvertedType = ToType;
2314 return true;
2315 }
2316
2317 // If the left-hand-side is nullptr_t, the right side can be a null
2318 // pointer constant.
2319 if (ToType->isNullPtrType() &&
2320 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) {
2321 ConvertedType = ToType;
2322 return true;
2323 }
2324
2325 const PointerType* ToTypePtr = ToType->getAs<PointerType>();
2326 if (!ToTypePtr)
2327 return false;
2328
2329 // A null pointer constant can be converted to a pointer type (C++ 4.10p1).
2330 if (isNullPointerConstantForConversion(From, InOverloadResolution, Context)) {
2331 ConvertedType = ToType;
2332 return true;
2333 }
2334
2335 // Beyond this point, both types need to be pointers
2336 // , including objective-c pointers.
2337 QualType ToPointeeType = ToTypePtr->getPointeeType();
2338 if (FromType->isObjCObjectPointerType() && ToPointeeType->isVoidType() &&
2339 !getLangOpts().ObjCAutoRefCount) {
2340 ConvertedType = BuildSimilarlyQualifiedPointerType(
2341 FromType->getAs<ObjCObjectPointerType>(),
2342 ToPointeeType,
2343 ToType, Context);
2344 return true;
2345 }
2346 const PointerType *FromTypePtr = FromType->getAs<PointerType>();
2347 if (!FromTypePtr)
2348 return false;
2349
2350 QualType FromPointeeType = FromTypePtr->getPointeeType();
2351
2352 // If the unqualified pointee types are the same, this can't be a
2353 // pointer conversion, so don't do all of the work below.
2354 if (Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType))
2355 return false;
2356
2357 // An rvalue of type "pointer to cv T," where T is an object type,
2358 // can be converted to an rvalue of type "pointer to cv void" (C++
2359 // 4.10p2).
2360 if (FromPointeeType->isIncompleteOrObjectType() &&
2361 ToPointeeType->isVoidType()) {
2362 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr,
2363 ToPointeeType,
2364 ToType, Context,
2365 /*StripObjCLifetime=*/true);
2366 return true;
2367 }
2368
2369 // MSVC allows implicit function to void* type conversion.
2370 if (getLangOpts().MSVCCompat && FromPointeeType->isFunctionType() &&
2371 ToPointeeType->isVoidType()) {
2372 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr,
2373 ToPointeeType,
2374 ToType, Context);
2375 return true;
2376 }
2377
2378 // When we're overloading in C, we allow a special kind of pointer
2379 // conversion for compatible-but-not-identical pointee types.
2380 if (!getLangOpts().CPlusPlus &&
2381 Context.typesAreCompatible(FromPointeeType, ToPointeeType)) {
2382 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr,
2383 ToPointeeType,
2384 ToType, Context);
2385 return true;
2386 }
2387
2388 // C++ [conv.ptr]p3:
2389 //
2390 // An rvalue of type "pointer to cv D," where D is a class type,
2391 // can be converted to an rvalue of type "pointer to cv B," where
2392 // B is a base class (clause 10) of D. If B is an inaccessible
2393 // (clause 11) or ambiguous (10.2) base class of D, a program that
2394 // necessitates this conversion is ill-formed. The result of the
2395 // conversion is a pointer to the base class sub-object of the
2396 // derived class object. The null pointer value is converted to
2397 // the null pointer value of the destination type.
2398 //
2399 // Note that we do not check for ambiguity or inaccessibility
2400 // here. That is handled by CheckPointerConversion.
2401 if (getLangOpts().CPlusPlus && FromPointeeType->isRecordType() &&
2402 ToPointeeType->isRecordType() &&
2403 !Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType) &&
2404 IsDerivedFrom(From->getBeginLoc(), FromPointeeType, ToPointeeType)) {
2405 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr,
2406 ToPointeeType,
2407 ToType, Context);
2408 return true;
2409 }
2410
2411 if (FromPointeeType->isVectorType() && ToPointeeType->isVectorType() &&
2412 Context.areCompatibleVectorTypes(FromPointeeType, ToPointeeType)) {
2413 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr,
2414 ToPointeeType,
2415 ToType, Context);
2416 return true;
2417 }
2418
2419 return false;
2420}
2421
2422/// Adopt the given qualifiers for the given type.
2423static QualType AdoptQualifiers(ASTContext &Context, QualType T, Qualifiers Qs){
2424 Qualifiers TQs = T.getQualifiers();
2425
2426 // Check whether qualifiers already match.
2427 if (TQs == Qs)
2428 return T;
2429
2430 if (Qs.compatiblyIncludes(TQs))
2431 return Context.getQualifiedType(T, Qs);
2432
2433 return Context.getQualifiedType(T.getUnqualifiedType(), Qs);
2434}
2435
2436/// isObjCPointerConversion - Determines whether this is an
2437/// Objective-C pointer conversion. Subroutine of IsPointerConversion,
2438/// with the same arguments and return values.
2439bool Sema::isObjCPointerConversion(QualType FromType, QualType ToType,
2440 QualType& ConvertedType,
2441 bool &IncompatibleObjC) {
2442 if (!getLangOpts().ObjC)
2443 return false;
2444
2445 // The set of qualifiers on the type we're converting from.
2446 Qualifiers FromQualifiers = FromType.getQualifiers();
2447
2448 // First, we handle all conversions on ObjC object pointer types.
2449 const ObjCObjectPointerType* ToObjCPtr =
2450 ToType->getAs<ObjCObjectPointerType>();
2451 const ObjCObjectPointerType *FromObjCPtr =
2452 FromType->getAs<ObjCObjectPointerType>();
2453
2454 if (ToObjCPtr && FromObjCPtr) {
2455 // If the pointee types are the same (ignoring qualifications),
2456 // then this is not a pointer conversion.
2457 if (Context.hasSameUnqualifiedType(ToObjCPtr->getPointeeType(),
2458 FromObjCPtr->getPointeeType()))
2459 return false;
2460
2461 // Conversion between Objective-C pointers.
2462 if (Context.canAssignObjCInterfaces(ToObjCPtr, FromObjCPtr)) {
2463 const ObjCInterfaceType* LHS = ToObjCPtr->getInterfaceType();
2464 const ObjCInterfaceType* RHS = FromObjCPtr->getInterfaceType();
2465 if (getLangOpts().CPlusPlus && LHS && RHS &&
2466 !ToObjCPtr->getPointeeType().isAtLeastAsQualifiedAs(
2467 FromObjCPtr->getPointeeType()))
2468 return false;
2469 ConvertedType = BuildSimilarlyQualifiedPointerType(FromObjCPtr,
2470 ToObjCPtr->getPointeeType(),
2471 ToType, Context);
2472 ConvertedType = AdoptQualifiers(Context, ConvertedType, FromQualifiers);
2473 return true;
2474 }
2475
2476 if (Context.canAssignObjCInterfaces(FromObjCPtr, ToObjCPtr)) {
2477 // Okay: this is some kind of implicit downcast of Objective-C
2478 // interfaces, which is permitted. However, we're going to
2479 // complain about it.
2480 IncompatibleObjC = true;
2481 ConvertedType = BuildSimilarlyQualifiedPointerType(FromObjCPtr,
2482 ToObjCPtr->getPointeeType(),
2483 ToType, Context);
2484 ConvertedType = AdoptQualifiers(Context, ConvertedType, FromQualifiers);
2485 return true;
2486 }
2487 }
2488 // Beyond this point, both types need to be C pointers or block pointers.
2489 QualType ToPointeeType;
2490 if (const PointerType *ToCPtr = ToType->getAs<PointerType>())
2491 ToPointeeType = ToCPtr->getPointeeType();
2492 else if (const BlockPointerType *ToBlockPtr =
2493 ToType->getAs<BlockPointerType>()) {
2494 // Objective C++: We're able to convert from a pointer to any object
2495 // to a block pointer type.
2496 if (FromObjCPtr && FromObjCPtr->isObjCBuiltinType()) {
2497 ConvertedType = AdoptQualifiers(Context, ToType, FromQualifiers);
2498 return true;
2499 }
2500 ToPointeeType = ToBlockPtr->getPointeeType();
2501 }
2502 else if (FromType->getAs<BlockPointerType>() &&
2503 ToObjCPtr && ToObjCPtr->isObjCBuiltinType()) {
2504 // Objective C++: We're able to convert from a block pointer type to a
2505 // pointer to any object.
2506 ConvertedType = AdoptQualifiers(Context, ToType, FromQualifiers);
2507 return true;
2508 }
2509 else
2510 return false;
2511
2512 QualType FromPointeeType;
2513 if (const PointerType *FromCPtr = FromType->getAs<PointerType>())
2514 FromPointeeType = FromCPtr->getPointeeType();
2515 else if (const BlockPointerType *FromBlockPtr =
2516 FromType->getAs<BlockPointerType>())
2517 FromPointeeType = FromBlockPtr->getPointeeType();
2518 else
2519 return false;
2520
2521 // If we have pointers to pointers, recursively check whether this
2522 // is an Objective-C conversion.
2523 if (FromPointeeType->isPointerType() && ToPointeeType->isPointerType() &&
2524 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType,
2525 IncompatibleObjC)) {
2526 // We always complain about this conversion.
2527 IncompatibleObjC = true;
2528 ConvertedType = Context.getPointerType(ConvertedType);
2529 ConvertedType = AdoptQualifiers(Context, ConvertedType, FromQualifiers);
2530 return true;
2531 }
2532 // Allow conversion of pointee being objective-c pointer to another one;
2533 // as in I* to id.
2534 if (FromPointeeType->getAs<ObjCObjectPointerType>() &&
2535 ToPointeeType->getAs<ObjCObjectPointerType>() &&
2536 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType,
2537 IncompatibleObjC)) {
2538
2539 ConvertedType = Context.getPointerType(ConvertedType);
2540 ConvertedType = AdoptQualifiers(Context, ConvertedType, FromQualifiers);
2541 return true;
2542 }
2543
2544 // If we have pointers to functions or blocks, check whether the only
2545 // differences in the argument and result types are in Objective-C
2546 // pointer conversions. If so, we permit the conversion (but
2547 // complain about it).
2548 const FunctionProtoType *FromFunctionType
2549 = FromPointeeType->getAs<FunctionProtoType>();
2550 const FunctionProtoType *ToFunctionType
2551 = ToPointeeType->getAs<FunctionProtoType>();
2552 if (FromFunctionType && ToFunctionType) {
2553 // If the function types are exactly the same, this isn't an
2554 // Objective-C pointer conversion.
2555 if (Context.getCanonicalType(FromPointeeType)
2556 == Context.getCanonicalType(ToPointeeType))
2557 return false;
2558
2559 // Perform the quick checks that will tell us whether these
2560 // function types are obviously different.
2561 if (FromFunctionType->getNumParams() != ToFunctionType->getNumParams() ||
2562 FromFunctionType->isVariadic() != ToFunctionType->isVariadic() ||
2563 FromFunctionType->getMethodQuals() != ToFunctionType->getMethodQuals())
2564 return false;
2565
2566 bool HasObjCConversion = false;
2567 if (Context.getCanonicalType(FromFunctionType->getReturnType()) ==
2568 Context.getCanonicalType(ToFunctionType->getReturnType())) {
2569 // Okay, the types match exactly. Nothing to do.
2570 } else if (isObjCPointerConversion(FromFunctionType->getReturnType(),
2571 ToFunctionType->getReturnType(),
2572 ConvertedType, IncompatibleObjC)) {
2573 // Okay, we have an Objective-C pointer conversion.
2574 HasObjCConversion = true;
2575 } else {
2576 // Function types are too different. Abort.
2577 return false;
2578 }
2579
2580 // Check argument types.
2581 for (unsigned ArgIdx = 0, NumArgs = FromFunctionType->getNumParams();
2582 ArgIdx != NumArgs; ++ArgIdx) {
2583 QualType FromArgType = FromFunctionType->getParamType(ArgIdx);
2584 QualType ToArgType = ToFunctionType->getParamType(ArgIdx);
2585 if (Context.getCanonicalType(FromArgType)
2586 == Context.getCanonicalType(ToArgType)) {
2587 // Okay, the types match exactly. Nothing to do.
2588 } else if (isObjCPointerConversion(FromArgType, ToArgType,
2589 ConvertedType, IncompatibleObjC)) {
2590 // Okay, we have an Objective-C pointer conversion.
2591 HasObjCConversion = true;
2592 } else {
2593 // Argument types are too different. Abort.
2594 return false;
2595 }
2596 }
2597
2598 if (HasObjCConversion) {
2599 // We had an Objective-C conversion. Allow this pointer
2600 // conversion, but complain about it.
2601 ConvertedType = AdoptQualifiers(Context, ToType, FromQualifiers);
2602 IncompatibleObjC = true;
2603 return true;
2604 }
2605 }
2606
2607 return false;
2608}
2609
2610/// Determine whether this is an Objective-C writeback conversion,
2611/// used for parameter passing when performing automatic reference counting.
2612///
2613/// \param FromType The type we're converting form.
2614///
2615/// \param ToType The type we're converting to.
2616///
2617/// \param ConvertedType The type that will be produced after applying
2618/// this conversion.
2619bool Sema::isObjCWritebackConversion(QualType FromType, QualType ToType,
2620 QualType &ConvertedType) {
2621 if (!getLangOpts().ObjCAutoRefCount ||
2622 Context.hasSameUnqualifiedType(FromType, ToType))
2623 return false;
2624
2625 // Parameter must be a pointer to __autoreleasing (with no other qualifiers).
2626 QualType ToPointee;
2627 if (const PointerType *ToPointer = ToType->getAs<PointerType>())
2628 ToPointee = ToPointer->getPointeeType();
2629 else
2630 return false;
2631
2632 Qualifiers ToQuals = ToPointee.getQualifiers();
2633 if (!ToPointee->isObjCLifetimeType() ||
2634 ToQuals.getObjCLifetime() != Qualifiers::OCL_Autoreleasing ||
2635 !ToQuals.withoutObjCLifetime().empty())
2636 return false;
2637
2638 // Argument must be a pointer to __strong to __weak.
2639 QualType FromPointee;
2640 if (const PointerType *FromPointer = FromType->getAs<PointerType>())
2641 FromPointee = FromPointer->getPointeeType();
2642 else
2643 return false;
2644
2645 Qualifiers FromQuals = FromPointee.getQualifiers();
2646 if (!FromPointee->isObjCLifetimeType() ||
2647 (FromQuals.getObjCLifetime() != Qualifiers::OCL_Strong &&
2648 FromQuals.getObjCLifetime() != Qualifiers::OCL_Weak))
2649 return false;
2650
2651 // Make sure that we have compatible qualifiers.
2652 FromQuals.setObjCLifetime(Qualifiers::OCL_Autoreleasing);
2653 if (!ToQuals.compatiblyIncludes(FromQuals))
2654 return false;
2655
2656 // Remove qualifiers from the pointee type we're converting from; they
2657 // aren't used in the compatibility check belong, and we'll be adding back
2658 // qualifiers (with __autoreleasing) if the compatibility check succeeds.
2659 FromPointee = FromPointee.getUnqualifiedType();
2660
2661 // The unqualified form of the pointee types must be compatible.
2662 ToPointee = ToPointee.getUnqualifiedType();
2663 bool IncompatibleObjC;
2664 if (Context.typesAreCompatible(FromPointee, ToPointee))
2665 FromPointee = ToPointee;
2666 else if (!isObjCPointerConversion(FromPointee, ToPointee, FromPointee,
2667 IncompatibleObjC))
2668 return false;
2669
2670 /// Construct the type we're converting to, which is a pointer to
2671 /// __autoreleasing pointee.
2672 FromPointee = Context.getQualifiedType(FromPointee, FromQuals);
2673 ConvertedType = Context.getPointerType(FromPointee);
2674 return true;
2675}
2676
2677bool Sema::IsBlockPointerConversion(QualType FromType, QualType ToType,
2678 QualType& ConvertedType) {
2679 QualType ToPointeeType;
2680 if (const BlockPointerType *ToBlockPtr =
2681 ToType->getAs<BlockPointerType>())
2682 ToPointeeType = ToBlockPtr->getPointeeType();
2683 else
2684 return false;
2685
2686 QualType FromPointeeType;
2687 if (const BlockPointerType *FromBlockPtr =
2688 FromType->getAs<BlockPointerType>())
2689 FromPointeeType = FromBlockPtr->getPointeeType();
2690 else
2691 return false;
2692 // We have pointer to blocks, check whether the only
2693 // differences in the argument and result types are in Objective-C
2694 // pointer conversions. If so, we permit the conversion.
2695
2696 const FunctionProtoType *FromFunctionType
2697 = FromPointeeType->getAs<FunctionProtoType>();
2698 const FunctionProtoType *ToFunctionType
2699 = ToPointeeType->getAs<FunctionProtoType>();
2700
2701 if (!FromFunctionType || !ToFunctionType)
2702 return false;
2703
2704 if (Context.hasSameType(FromPointeeType, ToPointeeType))
2705 return true;
2706
2707 // Perform the quick checks that will tell us whether these
2708 // function types are obviously different.
2709 if (FromFunctionType->getNumParams() != ToFunctionType->getNumParams() ||
2710 FromFunctionType->isVariadic() != ToFunctionType->isVariadic())
2711 return false;
2712
2713 FunctionType::ExtInfo FromEInfo = FromFunctionType->getExtInfo();
2714 FunctionType::ExtInfo ToEInfo = ToFunctionType->getExtInfo();
2715 if (FromEInfo != ToEInfo)
2716 return false;
2717
2718 bool IncompatibleObjC = false;
2719 if (Context.hasSameType(FromFunctionType->getReturnType(),
2720 ToFunctionType->getReturnType())) {
2721 // Okay, the types match exactly. Nothing to do.
2722 } else {
2723 QualType RHS = FromFunctionType->getReturnType();
2724 QualType LHS = ToFunctionType->getReturnType();
2725 if ((!getLangOpts().CPlusPlus || !RHS->isRecordType()) &&
2726 !RHS.hasQualifiers() && LHS.hasQualifiers())
2727 LHS = LHS.getUnqualifiedType();
2728
2729 if (Context.hasSameType(RHS,LHS)) {
2730 // OK exact match.
2731 } else if (isObjCPointerConversion(RHS, LHS,
2732 ConvertedType, IncompatibleObjC)) {
2733 if (IncompatibleObjC)
2734 return false;
2735 // Okay, we have an Objective-C pointer conversion.
2736 }
2737 else
2738 return false;
2739 }
2740
2741 // Check argument types.
2742 for (unsigned ArgIdx = 0, NumArgs = FromFunctionType->getNumParams();
2743 ArgIdx != NumArgs; ++ArgIdx) {
2744 IncompatibleObjC = false;
2745 QualType FromArgType = FromFunctionType->getParamType(ArgIdx);
2746 QualType ToArgType = ToFunctionType->getParamType(ArgIdx);
2747 if (Context.hasSameType(FromArgType, ToArgType)) {
2748 // Okay, the types match exactly. Nothing to do.
2749 } else if (isObjCPointerConversion(ToArgType, FromArgType,
2750 ConvertedType, IncompatibleObjC)) {
2751 if (IncompatibleObjC)
2752 return false;
2753 // Okay, we have an Objective-C pointer conversion.
2754 } else
2755 // Argument types are too different. Abort.
2756 return false;
2757 }
2758
2759 SmallVector<FunctionProtoType::ExtParameterInfo, 4> NewParamInfos;
2760 bool CanUseToFPT, CanUseFromFPT;
2761 if (!Context.mergeExtParameterInfo(ToFunctionType, FromFunctionType,
2762 CanUseToFPT, CanUseFromFPT,
2763 NewParamInfos))
2764 return false;
2765
2766 ConvertedType = ToType;
2767 return true;
2768}
2769
2770enum {
2771 ft_default,
2772 ft_different_class,
2773 ft_parameter_arity,
2774 ft_parameter_mismatch,
2775 ft_return_type,
2776 ft_qualifer_mismatch,
2777 ft_noexcept
2778};
2779
2780/// Attempts to get the FunctionProtoType from a Type. Handles
2781/// MemberFunctionPointers properly.
2782static const FunctionProtoType *tryGetFunctionProtoType(QualType FromType) {
2783 if (auto *FPT = FromType->getAs<FunctionProtoType>())
2784 return FPT;
2785
2786 if (auto *MPT = FromType->getAs<MemberPointerType>())
2787 return MPT->getPointeeType()->getAs<FunctionProtoType>();
2788
2789 return nullptr;
2790}
2791
2792/// HandleFunctionTypeMismatch - Gives diagnostic information for differeing
2793/// function types. Catches different number of parameter, mismatch in
2794/// parameter types, and different return types.
2795void Sema::HandleFunctionTypeMismatch(PartialDiagnostic &PDiag,
2796 QualType FromType, QualType ToType) {
2797 // If either type is not valid, include no extra info.
2798 if (FromType.isNull() || ToType.isNull()) {
13
Calling 'QualType::isNull'
19
Returning from 'QualType::isNull'
20
Calling 'QualType::isNull'
26
Returning from 'QualType::isNull'
27
Taking false branch
2799 PDiag << ft_default;
2800 return;
2801 }
2802
2803 // Get the function type from the pointers.
2804 if (FromType->isMemberPointerType() && ToType->isMemberPointerType()) {
28
Calling 'Type::isMemberPointerType'
31
Returning from 'Type::isMemberPointerType'
32
Calling 'Type::isMemberPointerType'
35
Returning from 'Type::isMemberPointerType'
36
Taking true branch
2805 const MemberPointerType *FromMember = FromType->getAs<MemberPointerType>(),
37
Assuming the object is not a 'MemberPointerType'
38
'FromMember' initialized to a null pointer value
2806 *ToMember = ToType->getAs<MemberPointerType>();
39
Assuming the object is not a 'MemberPointerType'
2807 if (!Context.hasSameType(FromMember->getClass(), ToMember->getClass())) {
40
Called C++ object pointer is null
2808 PDiag << ft_different_class << QualType(ToMember->getClass(), 0)
2809 << QualType(FromMember->getClass(), 0);
2810 return;
2811 }
2812 FromType = FromMember->getPointeeType();
2813 ToType = ToMember->getPointeeType();
2814 }
2815
2816 if (FromType->isPointerType())
2817 FromType = FromType->getPointeeType();
2818 if (ToType->isPointerType())
2819 ToType = ToType->getPointeeType();
2820
2821 // Remove references.
2822 FromType = FromType.getNonReferenceType();
2823 ToType = ToType.getNonReferenceType();
2824
2825 // Don't print extra info for non-specialized template functions.
2826 if (FromType->isInstantiationDependentType() &&
2827 !FromType->getAs<TemplateSpecializationType>()) {
2828 PDiag << ft_default;
2829 return;
2830 }
2831
2832 // No extra info for same types.
2833 if (Context.hasSameType(FromType, ToType)) {
2834 PDiag << ft_default;
2835 return;
2836 }
2837
2838 const FunctionProtoType *FromFunction = tryGetFunctionProtoType(FromType),
2839 *ToFunction = tryGetFunctionProtoType(ToType);
2840
2841 // Both types need to be function types.
2842 if (!FromFunction || !ToFunction) {
2843 PDiag << ft_default;
2844 return;
2845 }
2846
2847 if (FromFunction->getNumParams() != ToFunction->getNumParams()) {
2848 PDiag << ft_parameter_arity << ToFunction->getNumParams()
2849 << FromFunction->getNumParams();
2850 return;
2851 }
2852
2853 // Handle different parameter types.
2854 unsigned ArgPos;
2855 if (!FunctionParamTypesAreEqual(FromFunction, ToFunction, &ArgPos)) {
2856 PDiag << ft_parameter_mismatch << ArgPos + 1
2857 << ToFunction->getParamType(ArgPos)
2858 << FromFunction->getParamType(ArgPos);
2859 return;
2860 }
2861
2862 // Handle different return type.
2863 if (!Context.hasSameType(FromFunction->getReturnType(),
2864 ToFunction->getReturnType())) {
2865 PDiag << ft_return_type << ToFunction->getReturnType()
2866 << FromFunction->getReturnType();
2867 return;
2868 }
2869
2870 if (FromFunction->getMethodQuals() != ToFunction->getMethodQuals()) {
2871 PDiag << ft_qualifer_mismatch << ToFunction->getMethodQuals()
2872 << FromFunction->getMethodQuals();
2873 return;
2874 }
2875
2876 // Handle exception specification differences on canonical type (in C++17
2877 // onwards).
2878 if (cast<FunctionProtoType>(FromFunction->getCanonicalTypeUnqualified())
2879 ->isNothrow() !=
2880 cast<FunctionProtoType>(ToFunction->getCanonicalTypeUnqualified())
2881 ->isNothrow()) {
2882 PDiag << ft_noexcept;
2883 return;
2884 }
2885
2886 // Unable to find a difference, so add no extra info.
2887 PDiag << ft_default;
2888}
2889
2890/// FunctionParamTypesAreEqual - This routine checks two function proto types
2891/// for equality of their argument types. Caller has already checked that
2892/// they have same number of arguments. If the parameters are different,
2893/// ArgPos will have the parameter index of the first different parameter.
2894bool Sema::FunctionParamTypesAreEqual(const FunctionProtoType *OldType,
2895 const FunctionProtoType *NewType,
2896 unsigned *ArgPos) {
2897 for (FunctionProtoType::param_type_iterator O = OldType->param_type_begin(),
2898 N = NewType->param_type_begin(),
2899 E = OldType->param_type_end();
2900 O && (O != E); ++O, ++N) {
2901 if (!Context.hasSameType(O->getUnqualifiedType(),
2902 N->getUnqualifiedType())) {
2903 if (ArgPos)
2904 *ArgPos = O - OldType->param_type_begin();
2905 return false;
2906 }
2907 }
2908 return true;
2909}
2910
2911/// CheckPointerConversion - Check the pointer conversion from the
2912/// expression From to the type ToType. This routine checks for
2913/// ambiguous or inaccessible derived-to-base pointer
2914/// conversions for which IsPointerConversion has already returned
2915/// true. It returns true and produces a diagnostic if there was an
2916/// error, or returns false otherwise.
2917bool Sema::CheckPointerConversion(Expr *From, QualType ToType,
2918 CastKind &Kind,
2919 CXXCastPath& BasePath,
2920 bool IgnoreBaseAccess,
2921 bool Diagnose) {
2922 QualType FromType = From->getType();
2923 bool IsCStyleOrFunctionalCast = IgnoreBaseAccess;
2924
2925 Kind = CK_BitCast;
2926
2927 if (Diagnose && !IsCStyleOrFunctionalCast && !FromType->isAnyPointerType() &&
2928 From->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNotNull) ==
2929 Expr::NPCK_ZeroExpression) {
2930 if (Context.hasSameUnqualifiedType(From->getType(), Context.BoolTy))
2931 DiagRuntimeBehavior(From->getExprLoc(), From,
2932 PDiag(diag::warn_impcast_bool_to_null_pointer)
2933 << ToType << From->getSourceRange());
2934 else if (!isUnevaluatedContext())
2935 Diag(From->getExprLoc(), diag::warn_non_literal_null_pointer)
2936 << ToType << From->getSourceRange();
2937 }
2938 if (const PointerType *ToPtrType = ToType->getAs<PointerType>()) {
2939 if (const PointerType *FromPtrType = FromType->getAs<PointerType>()) {
2940 QualType FromPointeeType = FromPtrType->getPointeeType(),
2941 ToPointeeType = ToPtrType->getPointeeType();
2942
2943 if (FromPointeeType->isRecordType() && ToPointeeType->isRecordType() &&
2944 !Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType)) {
2945 // We must have a derived-to-base conversion. Check an
2946 // ambiguous or inaccessible conversion.
2947 unsigned InaccessibleID = 0;
2948 unsigned AmbigiousID = 0;
2949 if (Diagnose) {
2950 InaccessibleID = diag::err_upcast_to_inaccessible_base;
2951 AmbigiousID = diag::err_ambiguous_derived_to_base_conv;
2952 }
2953 if (CheckDerivedToBaseConversion(
2954 FromPointeeType, ToPointeeType, InaccessibleID, AmbigiousID,
2955 From->getExprLoc(), From->getSourceRange(), DeclarationName(),
2956 &BasePath, IgnoreBaseAccess))
2957 return true;
2958
2959 // The conversion was successful.
2960 Kind = CK_DerivedToBase;
2961 }
2962
2963 if (Diagnose && !IsCStyleOrFunctionalCast &&
2964 FromPointeeType->isFunctionType() && ToPointeeType->isVoidType()) {
2965 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-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaOverload.cpp"
, 2966, __PRETTY_FUNCTION__))
2966 "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-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaOverload.cpp"
, 2966, __PRETTY_FUNCTION__))
;
2967 Diag(From->getExprLoc(), diag::ext_ms_impcast_fn_obj)
2968 << From->getSourceRange();
2969 }
2970 }
2971 } else if (const ObjCObjectPointerType *ToPtrType =
2972 ToType->getAs<ObjCObjectPointerType>()) {
2973 if (const ObjCObjectPointerType *FromPtrType =
2974 FromType->getAs<ObjCObjectPointerType>()) {
2975 // Objective-C++ conversions are always okay.
2976 // FIXME: We should have a different class of conversions for the
2977 // Objective-C++ implicit conversions.
2978 if (FromPtrType->isObjCBuiltinType() || ToPtrType->isObjCBuiltinType())
2979 return false;
2980 } else if (FromType->isBlockPointerType()) {
2981 Kind = CK_BlockPointerToObjCPointerCast;
2982 } else {
2983 Kind = CK_CPointerToObjCPointerCast;
2984 }
2985 } else if (ToType->isBlockPointerType()) {
2986 if (!FromType->isBlockPointerType())
2987 Kind = CK_AnyPointerToBlockPointerCast;
2988 }
2989
2990 // We shouldn't fall into this case unless it's valid for other
2991 // reasons.
2992 if (From->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull))
2993 Kind = CK_NullToPointer;
2994
2995 return false;
2996}
2997
2998/// IsMemberPointerConversion - Determines whether the conversion of the
2999/// expression From, which has the (possibly adjusted) type FromType, can be
3000/// converted to the type ToType via a member pointer conversion (C++ 4.11).
3001/// If so, returns true and places the converted type (that might differ from
3002/// ToType in its cv-qualifiers at some level) into ConvertedType.
3003bool Sema::IsMemberPointerConversion(Expr *From, QualType FromType,
3004 QualType ToType,
3005 bool InOverloadResolution,
3006 QualType &ConvertedType) {
3007 const MemberPointerType *ToTypePtr = ToType->getAs<MemberPointerType>();
3008 if (!ToTypePtr)
3009 return false;
3010
3011 // A null pointer constant can be converted to a member pointer (C++ 4.11p1)
3012 if (From->isNullPointerConstant(Context,
3013 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull
3014 : Expr::NPC_ValueDependentIsNull)) {
3015 ConvertedType = ToType;
3016 return true;
3017 }
3018
3019 // Otherwise, both types have to be member pointers.
3020 const MemberPointerType *FromTypePtr = FromType->getAs<MemberPointerType>();
3021 if (!FromTypePtr)
3022 return false;
3023
3024 // A pointer to member of B can be converted to a pointer to member of D,
3025 // where D is derived from B (C++ 4.11p2).
3026 QualType FromClass(FromTypePtr->getClass(), 0);
3027 QualType ToClass(ToTypePtr->getClass(), 0);
3028
3029 if (!Context.hasSameUnqualifiedType(FromClass, ToClass) &&
3030 IsDerivedFrom(From->getBeginLoc(), ToClass, FromClass)) {
3031 ConvertedType = Context.getMemberPointerType(FromTypePtr->getPointeeType(),
3032 ToClass.getTypePtr());
3033 return true;
3034 }
3035
3036 return false;
3037}
3038
3039/// CheckMemberPointerConversion - Check the member pointer conversion from the
3040/// expression From to the type ToType. This routine checks for ambiguous or
3041/// virtual or inaccessible base-to-derived member pointer conversions
3042/// for which IsMemberPointerConversion has already returned true. It returns
3043/// true and produces a diagnostic if there was an error, or returns false
3044/// otherwise.
3045bool Sema::CheckMemberPointerConversion(Expr *From, QualType ToType,
3046 CastKind &Kind,
3047 CXXCastPath &BasePath,
3048 bool IgnoreBaseAccess) {
3049 QualType FromType = From->getType();
3050 const MemberPointerType *FromPtrType = FromType->getAs<MemberPointerType>();
3051 if (!FromPtrType) {
3052 // This must be a null pointer to member pointer conversion
3053 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-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaOverload.cpp"
, 3055, __PRETTY_FUNCTION__))
3054 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-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaOverload.cpp"
, 3055, __PRETTY_FUNCTION__))
3055 "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-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaOverload.cpp"
, 3055, __PRETTY_FUNCTION__))
;
3056 Kind = CK_NullToMemberPointer;
3057 return false;
3058 }
3059
3060 const MemberPointerType *ToPtrType = ToType->getAs<MemberPointerType>();
3061 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-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaOverload.cpp"
, 3062, __PRETTY_FUNCTION__))
3062 "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-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaOverload.cpp"
, 3062, __PRETTY_FUNCTION__))
;
3063
3064 QualType FromClass = QualType(FromPtrType->getClass(), 0);
3065 QualType ToClass = QualType(ToPtrType->getClass(), 0);
3066
3067 // FIXME: What about dependent types?
3068 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-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaOverload.cpp"
, 3068, __PRETTY_FUNCTION__))
;
3069 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-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaOverload.cpp"
, 3069, __PRETTY_FUNCTION__))
;
3070
3071 CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
3072 /*DetectVirtual=*/true);
3073 bool DerivationOkay =
3074 IsDerivedFrom(From->getBeginLoc(), ToClass, FromClass, Paths);
3075 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-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaOverload.cpp"
, 3076, __PRETTY_FUNCTION__))
3076 "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-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaOverload.cpp"
, 3076, __PRETTY_FUNCTION__))
;
3077 (void)DerivationOkay;
3078
3079 if (Paths.isAmbiguous(Context.getCanonicalType(FromClass).
3080 getUnqualifiedType())) {
3081 std::string PathDisplayStr = getAmbiguousPathsDisplayString(Paths);
3082 Diag(From->getExprLoc(), diag::err_ambiguous_memptr_conv)
3083 << 0 << FromClass << ToClass << PathDisplayStr << From->getSourceRange();
3084 return true;
3085 }
3086
3087 if (const RecordType *VBase = Paths.getDetectedVirtual()) {
3088 Diag(From->getExprLoc(), diag::err_memptr_conv_via_virtual)
3089 << FromClass << ToClass << QualType(VBase, 0)
3090 << From->getSourceRange();
3091 return true;
3092 }
3093
3094 if (!IgnoreBaseAccess)
3095 CheckBaseClassAccess(From->getExprLoc(), FromClass, ToClass,
3096 Paths.front(),
3097 diag::err_downcast_from_inaccessible_base);
3098
3099 // Must be a base to derived member conversion.
3100 BuildBasePathArray(Paths, BasePath);
3101 Kind = CK_BaseToDerivedMemberPointer;
3102 return false;
3103}
3104
3105/// Determine whether the lifetime conversion between the two given
3106/// qualifiers sets is nontrivial.
3107static bool isNonTrivialObjCLifetimeConversion(Qualifiers FromQuals,
3108 Qualifiers ToQuals) {
3109 // Converting anything to const __unsafe_unretained is trivial.
3110 if (ToQuals.hasConst() &&
3111 ToQuals.getObjCLifetime() == Qualifiers::OCL_ExplicitNone)
3112 return false;
3113
3114 return true;
3115}
3116
3117/// IsQualificationConversion - Determines whether the conversion from
3118/// an rvalue of type FromType to ToType is a qualification conversion
3119/// (C++ 4.4).
3120///
3121/// \param ObjCLifetimeConversion Output parameter that will be set to indicate
3122/// when the qualification conversion involves a change in the Objective-C
3123/// object lifetime.
3124bool
3125Sema::IsQualificationConversion(QualType FromType, QualType ToType,
3126 bool CStyle, bool &ObjCLifetimeConversion) {
3127 FromType = Context.getCanonicalType(FromType);
3128 ToType = Context.getCanonicalType(ToType);
3129 ObjCLifetimeConversion = false;
3130
3131 // If FromType and ToType are the same type, this is not a
3132 // qualification conversion.
3133 if (FromType.getUnqualifiedType() == ToType.getUnqualifiedType())
3134 return false;
3135
3136 // (C++ 4.4p4):
3137 // A conversion can add cv-qualifiers at levels other than the first
3138 // in multi-level pointers, subject to the following rules: [...]
3139 bool PreviousToQualsIncludeConst = true;
3140 bool UnwrappedAnyPointer = false;
3141 while (Context.UnwrapSimilarTypes(FromType, ToType)) {
3142 // Within each iteration of the loop, we check the qualifiers to
3143 // determine if this still looks like a qualification
3144 // conversion. Then, if all is well, we unwrap one more level of
3145 // pointers or pointers-to-members and do it all again
3146 // until there are no more pointers or pointers-to-members left to
3147 // unwrap.
3148 UnwrappedAnyPointer = true;
3149
3150 Qualifiers FromQuals = FromType.getQualifiers();
3151 Qualifiers ToQuals = ToType.getQualifiers();
3152
3153 // Ignore __unaligned qualifier if this type is void.
3154 if (ToType.getUnqualifiedType()->isVoidType())
3155 FromQuals.removeUnaligned();
3156
3157 // Objective-C ARC:
3158 // Check Objective-C lifetime conversions.
3159 if (FromQuals.getObjCLifetime() != ToQuals.getObjCLifetime() &&
3160 UnwrappedAnyPointer) {
3161 if (ToQuals.compatiblyIncludesObjCLifetime(FromQuals)) {
3162 if (isNonTrivialObjCLifetimeConversion(FromQuals, ToQuals))
3163 ObjCLifetimeConversion = true;
3164 FromQuals.removeObjCLifetime();
3165 ToQuals.removeObjCLifetime();
3166 } else {
3167 // Qualification conversions cannot cast between different
3168 // Objective-C lifetime qualifiers.
3169 return false;
3170 }
3171 }
3172
3173 // Allow addition/removal of GC attributes but not changing GC attributes.
3174 if (FromQuals.getObjCGCAttr() != ToQuals.getObjCGCAttr() &&
3175 (!FromQuals.hasObjCGCAttr() || !ToQuals.hasObjCGCAttr())) {
3176 FromQuals.removeObjCGCAttr();
3177 ToQuals.removeObjCGCAttr();
3178 }
3179
3180 // -- for every j > 0, if const is in cv 1,j then const is in cv
3181 // 2,j, and similarly for volatile.
3182 if (!CStyle && !ToQuals.compatiblyIncludes(FromQuals))
3183 return false;
3184
3185 // -- if the cv 1,j and cv 2,j are different, then const is in
3186 // every cv for 0 < k < j.
3187 if (!CStyle && FromQuals.getCVRQualifiers() != ToQuals.getCVRQualifiers()
3188 && !PreviousToQualsIncludeConst)
3189 return false;
3190
3191 // Keep track of whether all prior cv-qualifiers in the "to" type
3192 // include const.
3193 PreviousToQualsIncludeConst
3194 = PreviousToQualsIncludeConst && ToQuals.hasConst();
3195 }
3196
3197 // Allows address space promotion by language rules implemented in
3198 // Type::Qualifiers::isAddressSpaceSupersetOf.
3199 Qualifiers FromQuals = FromType.getQualifiers();
3200 Qualifiers ToQuals = ToType.getQualifiers();
3201 if (!ToQuals.isAddressSpaceSupersetOf(FromQuals) &&
3202 !FromQuals.isAddressSpaceSupersetOf(ToQuals)) {
3203 return false;
3204 }
3205
3206 // We are left with FromType and ToType being the pointee types
3207 // after unwrapping the original FromType and ToType the same number
3208 // of types. If we unwrapped any pointers, and if FromType and
3209 // ToType have the same unqualified type (since we checked
3210 // qualifiers above), then this is a qualification conversion.
3211 return UnwrappedAnyPointer && Context.hasSameUnqualifiedType(FromType,ToType);
3212}
3213
3214/// - Determine whether this is a conversion from a scalar type to an
3215/// atomic type.
3216///
3217/// If successful, updates \c SCS's second and third steps in the conversion
3218/// sequence to finish the conversion.
3219static bool tryAtomicConversion(Sema &S, Expr *From, QualType ToType,
3220 bool InOverloadResolution,
3221 StandardConversionSequence &SCS,
3222 bool CStyle) {
3223 const AtomicType *ToAtomic = ToType->getAs<AtomicType>();
3224 if (!ToAtomic)
3225 return false;
3226
3227 StandardConversionSequence InnerSCS;
3228 if (!IsStandardConversion(S, From, ToAtomic->getValueType(),
3229 InOverloadResolution, InnerSCS,
3230 CStyle, /*AllowObjCWritebackConversion=*/false))
3231 return false;
3232
3233 SCS.Second = InnerSCS.Second;
3234 SCS.setToType(1, InnerSCS.getToType(1));
3235 SCS.Third = InnerSCS.Third;
3236 SCS.QualificationIncludesObjCLifetime
3237 = InnerSCS.QualificationIncludesObjCLifetime;
3238 SCS.setToType(2, InnerSCS.getToType(2));
3239 return true;
3240}
3241
3242static bool isFirstArgumentCompatibleWithType(ASTContext &Context,
3243 CXXConstructorDecl *Constructor,
3244 QualType Type) {
3245 const FunctionProtoType *CtorType =
3246 Constructor->getType()->getAs<FunctionProtoType>();
3247 if (CtorType->getNumParams() > 0) {
3248 QualType FirstArg = CtorType->getParamType(0);
3249 if (Context.hasSameUnqualifiedType(Type, FirstArg.getNonReferenceType()))
3250 return true;
3251 }
3252 return false;
3253}
3254
3255static OverloadingResult
3256IsInitializerListConstructorConversion(Sema &S, Expr *From, QualType ToType,
3257 CXXRecordDecl *To,
3258 UserDefinedConversionSequence &User,
3259 OverloadCandidateSet &CandidateSet,
3260 bool AllowExplicit) {
3261 CandidateSet.clear(OverloadCandidateSet::CSK_InitByUserDefinedConversion);
3262 for (auto *D : S.LookupConstructors(To)) {
3263 auto Info = getConstructorInfo(D);
3264 if (!Info)
3265 continue;
3266
3267 bool Usable = !Info.Constructor->isInvalidDecl() &&
3268 S.isInitListConstructor(Info.Constructor) &&
3269 (AllowExplicit || !Info.Constructor->isExplicit());
3270 if (Usable) {
3271 // If the first argument is (a reference to) the target type,
3272 // suppress conversions.
3273 bool SuppressUserConversions = isFirstArgumentCompatibleWithType(
3274 S.Context, Info.Constructor, ToType);
3275 if (Info.ConstructorTmpl)
3276 S.AddTemplateOverloadCandidate(Info.ConstructorTmpl, Info.FoundDecl,
3277 /*ExplicitArgs*/ nullptr, From,
3278 CandidateSet, SuppressUserConversions,
3279 /*PartialOverloading*/ false,
3280 AllowExplicit);
3281 else
3282 S.AddOverloadCandidate(Info.Constructor, Info.FoundDecl, From,
3283 CandidateSet, SuppressUserConversions,
3284 /*PartialOverloading*/ false, AllowExplicit);
3285 }
3286 }
3287
3288 bool HadMultipleCandidates = (CandidateSet.size() > 1);
3289
3290 OverloadCandidateSet::iterator Best;
3291 switch (auto Result =
3292 CandidateSet.BestViableFunction(S, From->getBeginLoc(), Best)) {
3293 case OR_Deleted:
3294 case OR_Success: {
3295 // Record the standard conversion we used and the conversion function.
3296 CXXConstructorDecl *Constructor = cast<CXXConstructorDecl>(Best->Function);
3297 QualType ThisType = Constructor->getThisType();
3298 // Initializer lists don't have conversions as such.
3299 User.Before.setAsIdentityConversion();
3300 User.HadMultipleCandidates = HadMultipleCandidates;
3301 User.ConversionFunction = Constructor;
3302 User.FoundConversionFunction = Best->FoundDecl;
3303 User.After.setAsIdentityConversion();
3304 User.After.setFromType(ThisType->castAs<PointerType>()->getPointeeType());
3305 User.After.setAllToTypes(ToType);
3306 return Result;
3307 }
3308
3309 case OR_No_Viable_Function:
3310 return OR_No_Viable_Function;
3311 case OR_Ambiguous:
3312 return OR_Ambiguous;
3313 }
3314
3315 llvm_unreachable("Invalid OverloadResult!")::llvm::llvm_unreachable_internal("Invalid OverloadResult!", "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaOverload.cpp"
, 3315)
;
3316}
3317
3318/// Determines whether there is a user-defined conversion sequence
3319/// (C++ [over.ics.user]) that converts expression From to the type
3320/// ToType. If such a conversion exists, User will contain the
3321/// user-defined conversion sequence that performs such a conversion
3322/// and this routine will return true. Otherwise, this routine returns
3323/// false and User is unspecified.
3324///
3325/// \param AllowExplicit true if the conversion should consider C++0x
3326/// "explicit" conversion functions as well as non-explicit conversion
3327/// functions (C++0x [class.conv.fct]p2).
3328///
3329/// \param AllowObjCConversionOnExplicit true if the conversion should
3330/// allow an extra Objective-C pointer conversion on uses of explicit
3331/// constructors. Requires \c AllowExplicit to also be set.
3332static OverloadingResult
3333IsUserDefinedConversion(Sema &S, Expr *From, QualType ToType,
3334 UserDefinedConversionSequence &User,
3335 OverloadCandidateSet &CandidateSet,
3336 bool AllowExplicit,
3337 bool AllowObjCConversionOnExplicit) {
3338 assert(AllowExplicit || !AllowObjCConversionOnExplicit)((AllowExplicit || !AllowObjCConversionOnExplicit) ? static_cast
<void> (0) : __assert_fail ("AllowExplicit || !AllowObjCConversionOnExplicit"
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaOverload.cpp"
, 3338, __PRETTY_FUNCTION__))
;
3339 CandidateSet.clear(OverloadCandidateSet::CSK_InitByUserDefinedConversion);
3340
3341 // Whether we will only visit constructors.
3342 bool ConstructorsOnly = false;
3343
3344 // If the type we are conversion to is a class type, enumerate its
3345 // constructors.
3346 if (const RecordType *ToRecordType = ToType->getAs<RecordType>()) {
3347 // C++ [over.match.ctor]p1:
3348 // When objects of class type are direct-initialized (8.5), or
3349 // copy-initialized from an expression of the same or a
3350 // derived class type (8.5), overload resolution selects the
3351 // constructor. [...] For copy-initialization, the candidate
3352 // functions are all the converting constructors (12.3.1) of
3353 // that class. The argument list is the expression-list within
3354 // the parentheses of the initializer.
3355 if (S.Context.hasSameUnqualifiedType(ToType, From->getType()) ||
3356 (From->getType()->getAs<RecordType>() &&
3357 S.IsDerivedFrom(From->getBeginLoc(), From->getType(), ToType)))
3358 ConstructorsOnly = true;
3359
3360 if (!S.isCompleteType(From->getExprLoc(), ToType)) {
3361 // We're not going to find any constructors.
3362 } else if (CXXRecordDecl *ToRecordDecl
3363 = dyn_cast<CXXRecordDecl>(ToRecordType->getDecl())) {
3364
3365 Expr **Args = &From;
3366 unsigned NumArgs = 1;
3367 bool ListInitializing = false;
3368 if (InitListExpr *InitList = dyn_cast<InitListExpr>(From)) {
3369 // But first, see if there is an init-list-constructor that will work.
3370 OverloadingResult Result = IsInitializerListConstructorConversion(
3371 S, From, ToType, ToRecordDecl, User, CandidateSet, AllowExplicit);
3372 if (Result != OR_No_Viable_Function)
3373 return Result;
3374 // Never mind.
3375 CandidateSet.clear(
3376 OverloadCandidateSet::CSK_InitByUserDefinedConversion);
3377
3378 // If we're list-initializing, we pass the individual elements as
3379 // arguments, not the entire list.
3380 Args = InitList->getInits();
3381 NumArgs = InitList->getNumInits();
3382 ListInitializing = true;
3383 }
3384
3385 for (auto *D : S.LookupConstructors(ToRecordDecl)) {
3386 auto Info = getConstructorInfo(D);
3387 if (!Info)
3388 continue;
3389
3390 bool Usable = !Info.Constructor->isInvalidDecl();
3391 if (ListInitializing)
3392 Usable = Usable && (AllowExplicit || !Info.Constructor->isExplicit());
3393 else
3394 Usable = Usable &&
3395 Info.Constructor->isConvertingConstructor(AllowExplicit);
3396 if (Usable) {
3397 bool SuppressUserConversions = !ConstructorsOnly;
3398 if (SuppressUserConversions && ListInitializing) {
3399 SuppressUserConversions = false;
3400 if (NumArgs == 1) {
3401 // If the first argument is (a reference to) the target type,
3402 // suppress conversions.
3403 SuppressUserConversions = isFirstArgumentCompatibleWithType(
3404 S.Context, Info.Constructor, ToType);
3405 }
3406 }
3407 if (Info.ConstructorTmpl)
3408 S.AddTemplateOverloadCandidate(
3409 Info.ConstructorTmpl, Info.FoundDecl,
3410 /*ExplicitArgs*/ nullptr, llvm::makeArrayRef(Args, NumArgs),
3411 CandidateSet, SuppressUserConversions,
3412 /*PartialOverloading*/ false, AllowExplicit);
3413 else
3414 // Allow one user-defined conversion when user specifies a
3415 // From->ToType conversion via an static cast (c-style, etc).
3416 S.AddOverloadCandidate(Info.Constructor, Info.FoundDecl,
3417 llvm::makeArrayRef(Args, NumArgs),
3418 CandidateSet, SuppressUserConversions,
3419 /*PartialOverloading*/ false, AllowExplicit);
3420 }
3421 }
3422 }
3423 }
3424
3425 // Enumerate conversion functions, if we're allowed to.
3426 if (ConstructorsOnly || isa<InitListExpr>(From)) {
3427 } else if (!S.isCompleteType(From->getBeginLoc(), From->getType())) {
3428 // No conversion functions from incomplete types.
3429 } else if (const RecordType *FromRecordType =
3430 From->getType()->getAs<RecordType>()) {
3431 if (CXXRecordDecl *FromRecordDecl
3432 = dyn_cast<CXXRecordDecl>(FromRecordType->getDecl())) {
3433 // Add all of the conversion functions as candidates.
3434 const auto &Conversions = FromRecordDecl->getVisibleConversionFunctions();
3435 for (auto I = Conversions.begin(), E = Conversions.end(); I != E; ++I) {
3436 DeclAccessPair FoundDecl = I.getPair();
3437 NamedDecl *D = FoundDecl.getDecl();
3438 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext());
3439 if (isa<UsingShadowDecl>(D))
3440 D = cast<UsingShadowDecl>(D)->getTargetDecl();
3441
3442 CXXConversionDecl *Conv;
3443 FunctionTemplateDecl *ConvTemplate;
3444 if ((ConvTemplate = dyn_cast<FunctionTemplateDecl>(D)))
3445 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl());
3446 else
3447 Conv = cast<CXXConversionDecl>(D);
3448
3449 if (AllowExplicit || !Conv->isExplicit()) {
3450 if (ConvTemplate)
3451 S.AddTemplateConversionCandidate(
3452 ConvTemplate, FoundDecl, ActingContext, From, ToType,
3453 CandidateSet, AllowObjCConversionOnExplicit, AllowExplicit);
3454 else
3455 S.AddConversionCandidate(
3456 Conv, FoundDecl, ActingContext, From, ToType, CandidateSet,
3457 AllowObjCConversionOnExplicit, AllowExplicit);
3458 }
3459 }
3460 }
3461 }
3462
3463 bool HadMultipleCandidates = (CandidateSet.size() > 1);
3464
3465 OverloadCandidateSet::iterator Best;
3466 switch (auto Result =
3467 CandidateSet.BestViableFunction(S, From->getBeginLoc(), Best)) {
3468 case OR_Success:
3469 case OR_Deleted:
3470 // Record the standard conversion we used and the conversion function.
3471 if (CXXConstructorDecl *Constructor
3472 = dyn_cast<CXXConstructorDecl>(Best->Function)) {
3473 // C++ [over.ics.user]p1:
3474 // If the user-defined conversion is specified by a
3475 // constructor (12.3.1), the initial standard conversion
3476 // sequence converts the source type to the type required by
3477 // the argument of the constructor.
3478 //
3479 QualType ThisType = Constructor->getThisType();
3480 if (isa<InitListExpr>(From)) {
3481 // Initializer lists don't have conversions as such.
3482 User.Before.setAsIdentityConversion();
3483 } else {
3484 if (Best->Conversions[0].isEllipsis())
3485 User.EllipsisConversion = true;
3486 else {
3487 User.Before = Best->Conversions[0].Standard;
3488 User.EllipsisConversion = false;
3489 }
3490 }
3491 User.HadMultipleCandidates = HadMultipleCandidates;
3492 User.ConversionFunction = Constructor;
3493 User.FoundConversionFunction = Best->FoundDecl;
3494 User.After.setAsIdentityConversion();
3495 User.After.setFromType(ThisType->castAs<PointerType>()->getPointeeType());
3496 User.After.setAllToTypes(ToType);
3497 return Result;
3498 }
3499 if (CXXConversionDecl *Conversion
3500 = dyn_cast<CXXConversionDecl>(Best->Function)) {
3501 // C++ [over.ics.user]p1:
3502 //
3503 // [...] If the user-defined conversion is specified by a
3504 // conversion function (12.3.2), the initial standard
3505 // conversion sequence converts the source type to the
3506 // implicit object parameter of the conversion function.
3507 User.Before = Best->Conversions[0].Standard;
3508 User.HadMultipleCandidates = HadMultipleCandidates;
3509 User.ConversionFunction = Conversion;
3510 User.FoundConversionFunction = Best->FoundDecl;
3511 User.EllipsisConversion = false;
3512
3513 // C++ [over.ics.user]p2:
3514 // The second standard conversion sequence converts the
3515 // result of the user-defined conversion to the target type
3516 // for the sequence. Since an implicit conversion sequence
3517 // is an initialization, the special rules for
3518 // initialization by user-defined conversion apply when
3519 // selecting the best user-defined conversion for a
3520 // user-defined conversion sequence (see 13.3.3 and
3521 // 13.3.3.1).
3522 User.After = Best->FinalConversion;
3523 return Result;
3524 }
3525 llvm_unreachable("Not a constructor or conversion function?")::llvm::llvm_unreachable_internal("Not a constructor or conversion function?"
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaOverload.cpp"
, 3525)
;
3526
3527 case OR_No_Viable_Function:
3528 return OR_No_Viable_Function;
3529
3530 case OR_Ambiguous:
3531 return OR_Ambiguous;
3532 }
3533
3534 llvm_unreachable("Invalid OverloadResult!")::llvm::llvm_unreachable_internal("Invalid OverloadResult!", "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaOverload.cpp"
, 3534)
;
3535}
3536
3537bool
3538Sema::DiagnoseMultipleUserDefinedConversion(Expr *From, QualType ToType) {
3539 ImplicitConversionSequence ICS;
3540 OverloadCandidateSet CandidateSet(From->getExprLoc(),
3541 OverloadCandidateSet::CSK_Normal);
3542 OverloadingResult OvResult =
3543 IsUserDefinedConversion(*this, From, ToType, ICS.UserDefined,
3544 CandidateSet, false, false);
3545
3546 if (!(OvResult == OR_Ambiguous ||
3547 (OvResult == OR_No_Viable_Function && !CandidateSet.empty())))
3548 return false;
3549
3550 auto Cands = CandidateSet.CompleteCandidates(
3551 *this,
3552 OvResult == OR_Ambiguous ? OCD_AmbiguousCandidates : OCD_AllCandidates,
3553 From);
3554 if (OvResult == OR_Ambiguous)
3555 Diag(From->getBeginLoc(), diag::err_typecheck_ambiguous_condition)
3556 << From->getType() << ToType << From->getSourceRange();
3557 else { // OR_No_Viable_Function && !CandidateSet.empty()
3558 if (!RequireCompleteType(From->getBeginLoc(), ToType,
3559 diag::err_typecheck_nonviable_condition_incomplete,
3560 From->getType(), From->getSourceRange()))
3561 Diag(From->getBeginLoc(), diag::err_typecheck_nonviable_condition)
3562 << false << From->getType() << From->getSourceRange() << ToType;
3563 }
3564
3565 CandidateSet.NoteCandidates(
3566 *this, From, Cands);
3567 return true;
3568}
3569
3570/// Compare the user-defined conversion functions or constructors
3571/// of two user-defined conversion sequences to determine whether any ordering
3572/// is possible.
3573static ImplicitConversionSequence::CompareKind
3574compareConversionFunctions(Sema &S, FunctionDecl *Function1,
3575 FunctionDecl *Function2) {
3576 if (!S.getLangOpts().ObjC || !S.getLangOpts().CPlusPlus11)
3577 return ImplicitConversionSequence::Indistinguishable;
3578
3579 // Objective-C++:
3580 // If both conversion functions are implicitly-declared conversions from
3581 // a lambda closure type to a function pointer and a block pointer,
3582 // respectively, always prefer the conversion to a function pointer,
3583 // because the function pointer is more lightweight and is more likely
3584 // to keep code working.
3585 CXXConversionDecl *Conv1 = dyn_cast_or_null<CXXConversionDecl>(Function1);
3586 if (!Conv1)
3587 return ImplicitConversionSequence::Indistinguishable;
3588
3589 CXXConversionDecl *Conv2 = dyn_cast<CXXConversionDecl>(Function2);
3590 if (!Conv2)
3591 return ImplicitConversionSequence::Indistinguishable;
3592
3593 if (Conv1->getParent()->isLambda() && Conv2->getParent()->isLambda()) {
3594 bool Block1 = Conv1->getConversionType()->isBlockPointerType();
3595 bool Block2 = Conv2->getConversionType()->isBlockPointerType();
3596 if (Block1 != Block2)
3597 return Block1 ? ImplicitConversionSequence::Worse
3598 : ImplicitConversionSequence::Better;
3599 }
3600
3601 return ImplicitConversionSequence::Indistinguishable;
3602}
3603
3604static bool hasDeprecatedStringLiteralToCharPtrConversion(
3605 const ImplicitConversionSequence &ICS) {
3606 return (ICS.isStandard() && ICS.Standard.DeprecatedStringLiteralToCharPtr) ||
3607 (ICS.isUserDefined() &&
3608 ICS.UserDefined.Before.DeprecatedStringLiteralToCharPtr);
3609}
3610
3611/// CompareImplicitConversionSequences - Compare two implicit
3612/// conversion sequences to determine whether one is better than the
3613/// other or if they are indistinguishable (C++ 13.3.3.2).
3614static ImplicitConversionSequence::CompareKind
3615CompareImplicitConversionSequences(Sema &S, SourceLocation Loc,
3616 const ImplicitConversionSequence& ICS1,
3617 const ImplicitConversionSequence& ICS2)
3618{
3619 // (C++ 13.3.3.2p2): When comparing the basic forms of implicit
3620 // conversion sequences (as defined in 13.3.3.1)
3621 // -- a standard conversion sequence (13.3.3.1.1) is a better
3622 // conversion sequence than a user-defined conversion sequence or
3623 // an ellipsis conversion sequence, and
3624 // -- a user-defined conversion sequence (13.3.3.1.2) is a better
3625 // conversion sequence than an ellipsis conversion sequence
3626 // (13.3.3.1.3).
3627 //
3628 // C++0x [over.best.ics]p10:
3629 // For the purpose of ranking implicit conversion sequences as
3630 // described in 13.3.3.2, the ambiguous conversion sequence is
3631 // treated as a user-defined sequence that is indistinguishable
3632 // from any other user-defined conversion sequence.
3633
3634 // String literal to 'char *' conversion has been deprecated in C++03. It has
3635 // been removed from C++11. We still accept this conversion, if it happens at
3636 // the best viable function. Otherwise, this conversion is considered worse
3637 // than ellipsis conversion. Consider this as an extension; this is not in the
3638 // standard. For example:
3639 //
3640 // int &f(...); // #1
3641 // void f(char*); // #2
3642 // void g() { int &r = f("foo"); }
3643 //
3644 // In C++03, we pick #2 as the best viable function.
3645 // In C++11, we pick #1 as the best viable function, because ellipsis
3646 // conversion is better than string-literal to char* conversion (since there
3647 // is no such conversion in C++11). If there was no #1 at all or #1 couldn't
3648 // convert arguments, #2 would be the best viable function in C++11.
3649 // If the best viable function has this conversion, a warning will be issued
3650 // in C++03, or an ExtWarn (+SFINAE failure) will be issued in C++11.
3651
3652 if (S.getLangOpts().CPlusPlus11 && !S.getLangOpts().WritableStrings &&
3653 hasDeprecatedStringLiteralToCharPtrConversion(ICS1) !=
3654 hasDeprecatedStringLiteralToCharPtrConversion(ICS2))
3655 return hasDeprecatedStringLiteralToCharPtrConversion(ICS1)
3656 ? ImplicitConversionSequence::Worse
3657 : ImplicitConversionSequence::Better;
3658
3659 if (ICS1.getKindRank() < ICS2.getKindRank())
3660 return ImplicitConversionSequence::Better;
3661 if (ICS2.getKindRank() < ICS1.getKindRank())
3662 return ImplicitConversionSequence::Worse;
3663
3664 // The following checks require both conversion sequences to be of
3665 // the same kind.
3666 if (ICS1.getKind() != ICS2.getKind())
3667 return ImplicitConversionSequence::Indistinguishable;
3668
3669 ImplicitConversionSequence::CompareKind Result =
3670 ImplicitConversionSequence::Indistinguishable;
3671
3672 // Two implicit conversion sequences of the same form are
3673 // indistinguishable conversion sequences unless one of the
3674 // following rules apply: (C++ 13.3.3.2p3):
3675
3676 // List-initialization sequence L1 is a better conversion sequence than
3677 // list-initialization sequence L2 if:
3678 // - L1 converts to std::initializer_list<X> for some X and L2 does not, or,
3679 // if not that,
3680 // - L1 converts to type "array of N1 T", L2 converts to type "array of N2 T",
3681 // and N1 is smaller than N2.,
3682 // even if one of the other rules in this paragraph would otherwise apply.
3683 if (!ICS1.isBad()) {
3684 if (ICS1.isStdInitializerListElement() &&
3685 !ICS2.isStdInitializerListElement())
3686 return ImplicitConversionSequence::Better;
3687 if (!ICS1.isStdInitializerListElement() &&
3688 ICS2.isStdInitializerListElement())
3689 return ImplicitConversionSequence::Worse;
3690 }
3691
3692 if (ICS1.isStandard())
3693 // Standard conversion sequence S1 is a better conversion sequence than
3694 // standard conversion sequence S2 if [...]
3695 Result = CompareStandardConversionSequences(S, Loc,
3696 ICS1.Standard, ICS2.Standard);
3697 else if (ICS1.isUserDefined()) {
3698 // User-defined conversion sequence U1 is a better conversion
3699 // sequence than another user-defined conversion sequence U2 if
3700 // they contain the same user-defined conversion function or
3701 // constructor and if the second standard conversion sequence of
3702 // U1 is better than the second standard conversion sequence of
3703 // U2 (C++ 13.3.3.2p3).
3704 if (ICS1.UserDefined.ConversionFunction ==
3705 ICS2.UserDefined.ConversionFunction)
3706 Result = CompareStandardConversionSequences(S, Loc,
3707 ICS1.UserDefined.After,
3708 ICS2.UserDefined.After);
3709 else
3710 Result = compareConversionFunctions(S,
3711 ICS1.UserDefined.ConversionFunction,
3712 ICS2.UserDefined.ConversionFunction);
3713 }
3714
3715 return Result;
3716}
3717
3718// Per 13.3.3.2p3, compare the given standard conversion sequences to
3719// determine if one is a proper subset of the other.
3720static ImplicitConversionSequence::CompareKind
3721compareStandardConversionSubsets(ASTContext &Context,
3722 const StandardConversionSequence& SCS1,
3723 const StandardConversionSequence& SCS2) {
3724 ImplicitConversionSequence::CompareKind Result
3725 = ImplicitConversionSequence::Indistinguishable;
3726
3727 // the identity conversion sequence is considered to be a subsequence of
3728 // any non-identity conversion sequence
3729 if (SCS1.isIdentityConversion() && !SCS2.isIdentityConversion())
3730 return ImplicitConversionSequence::Better;
3731 else if (!SCS1.isIdentityConversion() && SCS2.isIdentityConversion())
3732 return ImplicitConversionSequence::Worse;
3733
3734 if (SCS1.Second != SCS2.Second) {
3735 if (SCS1.Second == ICK_Identity)
3736 Result = ImplicitConversionSequence::Better;
3737 else if (SCS2.Second == ICK_Identity)
3738 Result = ImplicitConversionSequence::Worse;
3739 else
3740 return ImplicitConversionSequence::Indistinguishable;
3741 } else if (!Context.hasSimilarType(SCS1.getToType(1), SCS2.getToType(1)))
3742 return ImplicitConversionSequence::Indistinguishable;
3743
3744 if (SCS1.Third == SCS2.Third) {
3745 return Context.hasSameType(SCS1.getToType(2), SCS2.getToType(2))? Result
3746 : ImplicitConversionSequence::Indistinguishable;
3747 }
3748
3749 if (SCS1.Third == ICK_Identity)
3750 return Result == ImplicitConversionSequence::Worse
3751 ? ImplicitConversionSequence::Indistinguishable
3752 : ImplicitConversionSequence::Better;
3753
3754 if (SCS2.Third == ICK_Identity)
3755 return Result == ImplicitConversionSequence::Better
3756 ? ImplicitConversionSequence::Indistinguishable
3757 : ImplicitConversionSequence::Worse;
3758
3759 return ImplicitConversionSequence::Indistinguishable;
3760}
3761
3762/// Determine whether one of the given reference bindings is better
3763/// than the other based on what kind of bindings they are.
3764static bool
3765isBetterReferenceBindingKind(const StandardConversionSequence &SCS1,
3766 const StandardConversionSequence &SCS2) {
3767 // C++0x [over.ics.rank]p3b4:
3768 // -- S1 and S2 are reference bindings (8.5.3) and neither refers to an
3769 // implicit object parameter of a non-static member function declared
3770 // without a ref-qualifier, and *either* S1 binds an rvalue reference
3771 // to an rvalue and S2 binds an lvalue reference *or S1 binds an
3772 // lvalue reference to a function lvalue and S2 binds an rvalue
3773 // reference*.
3774 //
3775 // FIXME: Rvalue references. We're going rogue with the above edits,
3776 // because the semantics in the current C++0x working paper (N3225 at the
3777 // time of this writing) break the standard definition of std::forward
3778 // and std::reference_wrapper when dealing with references to functions.
3779 // Proposed wording changes submitted to CWG for consideration.
3780 if (SCS1.BindsImplicitObjectArgumentWithoutRefQualifier ||
3781 SCS2.BindsImplicitObjectArgumentWithoutRefQualifier)
3782 return false;
3783
3784 return (!SCS1.IsLvalueReference && SCS1.BindsToRvalue &&
3785 SCS2.IsLvalueReference) ||
3786 (SCS1.IsLvalueReference && SCS1.BindsToFunctionLvalue &&
3787 !SCS2.IsLvalueReference && SCS2.BindsToFunctionLvalue);
3788}
3789
3790enum class FixedEnumPromotion {
3791 None,
3792 ToUnderlyingType,
3793 ToPromotedUnderlyingType
3794};
3795
3796/// Returns kind of fixed enum promotion the \a SCS uses.
3797static FixedEnumPromotion
3798getFixedEnumPromtion(Sema &S, const StandardConversionSequence &SCS) {
3799
3800 if (SCS.Second != ICK_Integral_Promotion)
3801 return FixedEnumPromotion::None;
3802
3803 QualType FromType = SCS.getFromType();
3804 if (!FromType->isEnumeralType())
3805 return FixedEnumPromotion::None;
3806
3807 EnumDecl *Enum = FromType->getAs<EnumType>()->getDecl();
3808 if (!Enum->isFixed())
3809 return FixedEnumPromotion::None;
3810
3811 QualType UnderlyingType = Enum->getIntegerType();
3812 if (S.Context.hasSameType(SCS.getToType(1), UnderlyingType))
3813 return FixedEnumPromotion::ToUnderlyingType;
3814
3815 return FixedEnumPromotion::ToPromotedUnderlyingType;
3816}
3817
3818/// CompareStandardConversionSequences - Compare two standard
3819/// conversion sequences to determine whether one is better than the
3820/// other or if they are indistinguishable (C++ 13.3.3.2p3).
3821static ImplicitConversionSequence::CompareKind
3822CompareStandardConversionSequences(Sema &S, SourceLocation Loc,
3823 const StandardConversionSequence& SCS1,
3824 const StandardConversionSequence& SCS2)
3825{
3826 // Standard conversion sequence S1 is a better conversion sequence
3827 // than standard conversion sequence S2 if (C++ 13.3.3.2p3):
3828
3829 // -- S1 is a proper subsequence of S2 (comparing the conversion
3830 // sequences in the canonical form defined by 13.3.3.1.1,
3831 // excluding any Lvalue Transformation; the identity conversion
3832 // sequence is considered to be a subsequence of any
3833 // non-identity conversion sequence) or, if not that,
3834 if (ImplicitConversionSequence::CompareKind CK
3835 = compareStandardConversionSubsets(S.Context, SCS1, SCS2))
3836 return CK;
3837
3838 // -- the rank of S1 is better than the rank of S2 (by the rules
3839 // defined below), or, if not that,
3840 ImplicitConversionRank Rank1 = SCS1.getRank();
3841 ImplicitConversionRank Rank2 = SCS2.getRank();
3842 if (Rank1 < Rank2)
3843 return ImplicitConversionSequence::Better;
3844 else if (Rank2 < Rank1)
3845 return ImplicitConversionSequence::Worse;
3846
3847 // (C++ 13.3.3.2p4): Two conversion sequences with the same rank
3848 // are indistinguishable unless one of the following rules
3849 // applies:
3850
3851 // A conversion that is not a conversion of a pointer, or
3852 // pointer to member, to bool is better than another conversion
3853 // that is such a conversion.
3854 if (SCS1.isPointerConversionToBool() != SCS2.isPointerConversionToBool())
3855 return SCS2.isPointerConversionToBool()
3856 ? ImplicitConversionSequence::Better
3857 : ImplicitConversionSequence::Worse;
3858
3859 // C++14 [over.ics.rank]p4b2:
3860 // This is retroactively applied to C++11 by CWG 1601.
3861 //
3862 // A conversion that promotes an enumeration whose underlying type is fixed
3863 // to its underlying type is better than one that promotes to the promoted
3864 // underlying type, if the two are different.
3865 FixedEnumPromotion FEP1 = getFixedEnumPromtion(S, SCS1);
3866 FixedEnumPromotion FEP2 = getFixedEnumPromtion(S, SCS2);
3867 if (FEP1 != FixedEnumPromotion::None && FEP2 != FixedEnumPromotion::None &&
3868 FEP1 != FEP2)
3869 return FEP1 == FixedEnumPromotion::ToUnderlyingType
3870 ? ImplicitConversionSequence::Better
3871 : ImplicitConversionSequence::Worse;
3872
3873 // C++ [over.ics.rank]p4b2:
3874 //
3875 // If class B is derived directly or indirectly from class A,
3876 // conversion of B* to A* is better than conversion of B* to
3877 // void*, and conversion of A* to void* is better than conversion
3878 // of B* to void*.
3879 bool SCS1ConvertsToVoid
3880 = SCS1.isPointerConversionToVoidPointer(S.Context);
3881 bool SCS2ConvertsToVoid
3882 = SCS2.isPointerConversionToVoidPointer(S.Context);
3883 if (SCS1ConvertsToVoid != SCS2ConvertsToVoid) {
3884 // Exactly one of the conversion sequences is a conversion to
3885 // a void pointer; it's the worse conversion.
3886 return SCS2ConvertsToVoid ? ImplicitConversionSequence::Better
3887 : ImplicitConversionSequence::Worse;
3888 } else if (!SCS1ConvertsToVoid && !SCS2ConvertsToVoid) {
3889 // Neither conversion sequence converts to a void pointer; compare
3890 // their derived-to-base conversions.
3891 if (ImplicitConversionSequence::CompareKind DerivedCK
3892 = CompareDerivedToBaseConversions(S, Loc, SCS1, SCS2))
3893 return DerivedCK;
3894 } else if (SCS1ConvertsToVoid && SCS2ConvertsToVoid &&
3895 !S.Context.hasSameType(SCS1.getFromType(), SCS2.getFromType())) {
3896 // Both conversion sequences are conversions to void
3897 // pointers. Compare the source types to determine if there's an
3898 // inheritance relationship in their sources.
3899 QualType FromType1 = SCS1.getFromType();
3900 QualType FromType2 = SCS2.getFromType();
3901
3902 // Adjust the types we're converting from via the array-to-pointer
3903 // conversion, if we need to.
3904 if (SCS1.First == ICK_Array_To_Pointer)
3905 FromType1 = S.Context.getArrayDecayedType(FromType1);
3906 if (SCS2.First == ICK_Array_To_Pointer)
3907 FromType2 = S.Context.getArrayDecayedType(FromType2);
3908
3909 QualType FromPointee1 = FromType1->getPointeeType().getUnqualifiedType();
3910 QualType FromPointee2 = FromType2->getPointeeType().getUnqualifiedType();
3911
3912 if (S.IsDerivedFrom(Loc, FromPointee2, FromPointee1))
3913 return ImplicitConversionSequence::Better;
3914 else if (S.IsDerivedFrom(Loc, FromPointee1, FromPointee2))
3915 return ImplicitConversionSequence::Worse;
3916
3917 // Objective-C++: If one interface is more specific than the
3918 // other, it is the better one.
3919 const ObjCObjectPointerType* FromObjCPtr1
3920 = FromType1->getAs<ObjCObjectPointerType>();
3921 const ObjCObjectPointerType* FromObjCPtr2
3922 = FromType2->getAs<ObjCObjectPointerType>();
3923 if (FromObjCPtr1 && FromObjCPtr2) {
3924 bool AssignLeft = S.Context.canAssignObjCInterfaces(FromObjCPtr1,
3925 FromObjCPtr2);
3926 bool AssignRight = S.Context.canAssignObjCInterfaces(FromObjCPtr2,
3927 FromObjCPtr1);
3928 if (AssignLeft != AssignRight) {
3929 return AssignLeft? ImplicitConversionSequence::Better
3930 : ImplicitConversionSequence::Worse;
3931 }
3932 }
3933 }
3934
3935 // Compare based on qualification conversions (C++ 13.3.3.2p3,
3936 // bullet 3).
3937 if (ImplicitConversionSequence::CompareKind QualCK
3938 = CompareQualificationConversions(S, SCS1, SCS2))
3939 return QualCK;
3940
3941 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding) {
3942 // Check for a better reference binding based on the kind of bindings.
3943 if (isBetterReferenceBindingKind(SCS1, SCS2))
3944 return ImplicitConversionSequence::Better;
3945 else if (isBetterReferenceBindingKind(SCS2, SCS1))
3946 return ImplicitConversionSequence::Worse;
3947
3948 // C++ [over.ics.rank]p3b4:
3949 // -- S1 and S2 are reference bindings (8.5.3), and the types to
3950 // which the references refer are the same type except for
3951 // top-level cv-qualifiers, and the type to which the reference
3952 // initialized by S2 refers is more cv-qualified than the type
3953 // to which the reference initialized by S1 refers.
3954 QualType T1 = SCS1.getToType(2);
3955 QualType T2 = SCS2.getToType(2);
3956 T1 = S.Context.getCanonicalType(T1);
3957 T2 = S.Context.getCanonicalType(T2);
3958 Qualifiers T1Quals, T2Quals;
3959 QualType UnqualT1 = S.Context.getUnqualifiedArrayType(T1, T1Quals);
3960 QualType UnqualT2 = S.Context.getUnqualifiedArrayType(T2, T2Quals);
3961 if (UnqualT1 == UnqualT2) {
3962 // Objective-C++ ARC: If the references refer to objects with different
3963 // lifetimes, prefer bindings that don't change lifetime.
3964 if (SCS1.ObjCLifetimeConversionBinding !=
3965 SCS2.ObjCLifetimeConversionBinding) {
3966 return SCS1.ObjCLifetimeConversionBinding
3967 ? ImplicitConversionSequence::Worse
3968 : ImplicitConversionSequence::Better;
3969 }
3970
3971 // If the type is an array type, promote the element qualifiers to the
3972 // type for comparison.
3973 if (isa<ArrayType>(T1) && T1Quals)
3974 T1 = S.Context.getQualifiedType(UnqualT1, T1Quals);
3975 if (isa<ArrayType>(T2) && T2Quals)
3976 T2 = S.Context.getQualifiedType(UnqualT2, T2Quals);
3977 if (T2.isMoreQualifiedThan(T1))
3978 return ImplicitConversionSequence::Better;
3979 else if (T1.isMoreQualifiedThan(T2))
3980 return ImplicitConversionSequence::Worse;
3981 }
3982 }
3983
3984 // In Microsoft mode, prefer an integral conversion to a
3985 // floating-to-integral conversion if the integral conversion
3986 // is between types of the same size.
3987 // For example:
3988 // void f(float);
3989 // void f(int);
3990 // int main {
3991 // long a;
3992 // f(a);
3993 // }
3994 // Here, MSVC will call f(int) instead of generating a compile error
3995 // as clang will do in standard mode.
3996 if (S.getLangOpts().MSVCCompat && SCS1.Second == ICK_Integral_Conversion &&
3997 SCS2.Second == ICK_Floating_Integral &&
3998 S.Context.getTypeSize(SCS1.getFromType()) ==
3999 S.Context.getTypeSize(SCS1.getToType(2)))
4000 return ImplicitConversionSequence::Better;
4001
4002 // Prefer a compatible vector conversion over a lax vector conversion
4003 // For example:
4004 //
4005 // typedef float __v4sf __attribute__((__vector_size__(16)));
4006 // void f(vector float);
4007 // void f(vector signed int);
4008 // int main() {
4009 // __v4sf a;
4010 // f(a);
4011 // }
4012 // Here, we'd like to choose f(vector float) and not
4013 // report an ambiguous call error
4014 if (SCS1.Second == ICK_Vector_Conversion &&
4015 SCS2.Second == ICK_Vector_Conversion) {
4016 bool SCS1IsCompatibleVectorConversion = S.Context.areCompatibleVectorTypes(
4017 SCS1.getFromType(), SCS1.getToType(2));
4018 bool SCS2IsCompatibleVectorConversion = S.Context.areCompatibleVectorTypes(
4019 SCS2.getFromType(), SCS2.getToType(2));
4020
4021 if (SCS1IsCompatibleVectorConversion != SCS2IsCompatibleVectorConversion)
4022 return SCS1IsCompatibleVectorConversion
4023 ? ImplicitConversionSequence::Better
4024 : ImplicitConversionSequence::Worse;
4025 }
4026
4027 return ImplicitConversionSequence::Indistinguishable;
4028}
4029
4030/// CompareQualificationConversions - Compares two standard conversion
4031/// sequences to determine whether they can be ranked based on their
4032/// qualification conversions (C++ 13.3.3.2p3 bullet 3).
4033static ImplicitConversionSequence::CompareKind
4034CompareQualificationConversions(Sema &S,
4035 const StandardConversionSequence& SCS1,
4036 const StandardConversionSequence& SCS2) {
4037 // C++ 13.3.3.2p3:
4038 // -- S1 and S2 differ only in their qualification conversion and
4039 // yield similar types T1 and T2 (C++ 4.4), respectively, and the
4040 // cv-qualification signature of type T1 is a proper subset of
4041 // the cv-qualification signature of type T2, and S1 is not the
4042 // deprecated string literal array-to-pointer conversion (4.2).
4043 if (SCS1.First != SCS2.First || SCS1.Second != SCS2.Second ||
4044 SCS1.Third != SCS2.Third || SCS1.Third != ICK_Qualification)
4045 return ImplicitConversionSequence::Indistinguishable;
4046
4047 // FIXME: the example in the standard doesn't use a qualification
4048 // conversion (!)
4049 QualType T1 = SCS1.getToType(2);
4050 QualType T2 = SCS2.getToType(2);
4051 T1 = S.Context.getCanonicalType(T1);
4052 T2 = S.Context.getCanonicalType(T2);
4053 Qualifiers T1Quals, T2Quals;
4054 QualType UnqualT1 = S.Context.getUnqualifiedArrayType(T1, T1Quals);
4055 QualType UnqualT2 = S.Context.getUnqualifiedArrayType(T2, T2Quals);
4056
4057 // If the types are the same, we won't learn anything by unwrapped
4058 // them.
4059 if (UnqualT1 == UnqualT2)
4060 return ImplicitConversionSequence::Indistinguishable;
4061
4062 // If the type is an array type, promote the element qualifiers to the type
4063 // for comparison.
4064 if (isa<ArrayType>(T1) && T1Quals)
4065 T1 = S.Context.getQualifiedType(UnqualT1, T1Quals);
4066 if (isa<ArrayType>(T2) && T2Quals)
4067 T2 = S.Context.getQualifiedType(UnqualT2, T2Quals);
4068
4069 ImplicitConversionSequence::CompareKind Result
4070 = ImplicitConversionSequence::Indistinguishable;
4071
4072 // Objective-C++ ARC:
4073 // Prefer qualification conversions not involving a change in lifetime
4074 // to qualification conversions that do not change lifetime.
4075 if (SCS1.QualificationIncludesObjCLifetime !=
4076 SCS2.QualificationIncludesObjCLifetime) {
4077 Result = SCS1.QualificationIncludesObjCLifetime
4078 ? ImplicitConversionSequence::Worse
4079 : ImplicitConversionSequence::Better;
4080 }
4081
4082 while (S.Context.UnwrapSimilarTypes(T1, T2)) {
4083 // Within each iteration of the loop, we check the qualifiers to
4084 // determine if this still looks like a qualification
4085 // conversion. Then, if all is well, we unwrap one more level of
4086 // pointers or pointers-to-members and do it all again
4087 // until there are no more pointers or pointers-to-members left
4088 // to unwrap. This essentially mimics what
4089 // IsQualificationConversion does, but here we're checking for a
4090 // strict subset of qualifiers.
4091 if (T1.getQualifiers().withoutObjCLifetime() ==
4092 T2.getQualifiers().withoutObjCLifetime())
4093 // The qualifiers are the same, so this doesn't tell us anything
4094 // about how the sequences rank.
4095 // ObjC ownership quals are omitted above as they interfere with
4096 // the ARC overload rule.
4097 ;
4098 else if (T2.isMoreQualifiedThan(T1)) {
4099 // T1 has fewer qualifiers, so it could be the better sequence.
4100 if (Result == ImplicitConversionSequence::Worse)
4101 // Neither has qualifiers that are a subset of the other's
4102 // qualifiers.
4103 return ImplicitConversionSequence::Indistinguishable;
4104
4105 Result = ImplicitConversionSequence::Better;
4106 } else if (T1.isMoreQualifiedThan(T2)) {
4107 // T2 has fewer qualifiers, so it could be the better sequence.
4108 if (Result == ImplicitConversionSequence::Better)
4109 // Neither has qualifiers that are a subset of the other's
4110 // qualifiers.
4111 return ImplicitConversionSequence::Indistinguishable;
4112
4113 Result = ImplicitConversionSequence::Worse;
4114 } else {
4115 // Qualifiers are disjoint.
4116 return ImplicitConversionSequence::Indistinguishable;
4117 }
4118
4119 // If the types after this point are equivalent, we're done.
4120 if (S.Context.hasSameUnqualifiedType(T1, T2))
4121 break;
4122 }
4123
4124 // Check that the winning standard conversion sequence isn't using
4125 // the deprecated string literal array to pointer conversion.
4126 switch (Result) {
4127 case ImplicitConversionSequence::Better:
4128 if (SCS1.DeprecatedStringLiteralToCharPtr)
4129 Result = ImplicitConversionSequence::Indistinguishable;
4130 break;
4131
4132 case ImplicitConversionSequence::Indistinguishable:
4133 break;
4134
4135 case ImplicitConversionSequence::Worse:
4136 if (SCS2.DeprecatedStringLiteralToCharPtr)
4137 Result = ImplicitConversionSequence::Indistinguishable;
4138 break;
4139 }
4140
4141 return Result;
4142}
4143
4144/// CompareDerivedToBaseConversions - Compares two standard conversion
4145/// sequences to determine whether they can be ranked based on their
4146/// various kinds of derived-to-base conversions (C++
4147/// [over.ics.rank]p4b3). As part of these checks, we also look at
4148/// conversions between Objective-C interface types.
4149static ImplicitConversionSequence::CompareKind
4150CompareDerivedToBaseConversions(Sema &S, SourceLocation Loc,
4151 const StandardConversionSequence& SCS1,
4152 const StandardConversionSequence& SCS2) {
4153 QualType FromType1 = SCS1.getFromType();
4154 QualType ToType1 = SCS1.getToType(1);
4155 QualType FromType2 = SCS2.getFromType();
4156 QualType ToType2 = SCS2.getToType(1);
4157
4158 // Adjust the types we're converting from via the array-to-pointer
4159 // conversion, if we need to.
4160 if (SCS1.First == ICK_Array_To_Pointer)
4161 FromType1 = S.Context.getArrayDecayedType(FromType1);
4162 if (SCS2.First == ICK_Array_To_Pointer)
4163 FromType2 = S.Context.getArrayDecayedType(FromType2);
4164
4165 // Canonicalize all of the types.
4166 FromType1 = S.Context.getCanonicalType(FromType1);
4167 ToType1 = S.Context.getCanonicalType(ToType1);
4168 FromType2 = S.Context.getCanonicalType(FromType2);
4169 ToType2 = S.Context.getCanonicalType(ToType2);
4170
4171 // C++ [over.ics.rank]p4b3:
4172 //
4173 // If class B is derived directly or indirectly from class A and
4174 // class C is derived directly or indirectly from B,
4175 //
4176 // Compare based on pointer conversions.
4177 if (SCS1.Second == ICK_Pointer_Conversion &&
4178 SCS2.Second == ICK_Pointer_Conversion &&
4179 /*FIXME: Remove if Objective-C id conversions get their own rank*/
4180 FromType1->isPointerType() && FromType2->isPointerType() &&
4181 ToType1->isPointerType() && ToType2->isPointerType()) {
4182 QualType FromPointee1 =
4183 FromType1->castAs<PointerType>()->getPointeeType().getUnqualifiedType();
4184 QualType ToPointee1 =
4185 ToType1->castAs<PointerType>()->getPointeeType().getUnqualifiedType();
4186 QualType FromPointee2 =
4187 FromType2->castAs<PointerType>()->getPointeeType().getUnqualifiedType();
4188 QualType ToPointee2 =
4189 ToType2->castAs<PointerType>()->getPointeeType().getUnqualifiedType();
4190
4191 // -- conversion of C* to B* is better than conversion of C* to A*,
4192 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) {
4193 if (S.IsDerivedFrom(Loc, ToPointee1, ToPointee2))
4194 return ImplicitConversionSequence::Better;
4195 else if (S.IsDerivedFrom(Loc, ToPointee2, ToPointee1))
4196 return ImplicitConversionSequence::Worse;
4197 }
4198
4199 // -- conversion of B* to A* is better than conversion of C* to A*,
4200 if (FromPointee1 != FromPointee2 && ToPointee1 == ToPointee2) {
4201 if (S.IsDerivedFrom(Loc, FromPointee2, FromPointee1))
4202 return ImplicitConversionSequence::Better;
4203 else if (S.IsDerivedFrom(Loc, FromPointee1, FromPointee2))
4204 return ImplicitConversionSequence::Worse;
4205 }
4206 } else if (SCS1.Second == ICK_Pointer_Conversion &&
4207 SCS2.Second == ICK_Pointer_Conversion) {
4208 const ObjCObjectPointerType *FromPtr1
4209 = FromType1->getAs<ObjCObjectPointerType>();
4210 const ObjCObjectPointerType *FromPtr2
4211 = FromType2->getAs<ObjCObjectPointerType>();
4212 const ObjCObjectPointerType *ToPtr1
4213 = ToType1->getAs<ObjCObjectPointerType>();
4214 const ObjCObjectPointerType *ToPtr2
4215 = ToType2->getAs<ObjCObjectPointerType>();
4216
4217 if (FromPtr1 && FromPtr2 && ToPtr1 && ToPtr2) {
4218 // Apply the same conversion ranking rules for Objective-C pointer types
4219 // that we do for C++ pointers to class types. However, we employ the
4220 // Objective-C pseudo-subtyping relationship used for assignment of
4221 // Objective-C pointer types.
4222 bool FromAssignLeft
4223 = S.Context.canAssignObjCInterfaces(FromPtr1, FromPtr2);
4224 bool FromAssignRight
4225 = S.Context.canAssignObjCInterfaces(FromPtr2, FromPtr1);
4226 bool ToAssignLeft
4227 = S.Context.canAssignObjCInterfaces(ToPtr1, ToPtr2);
4228 bool ToAssignRight
4229 = S.Context.canAssignObjCInterfaces(ToPtr2, ToPtr1);
4230
4231 // A conversion to an a non-id object pointer type or qualified 'id'
4232 // type is better than a conversion to 'id'.
4233 if (ToPtr1->isObjCIdType() &&
4234 (ToPtr2->isObjCQualifiedIdType() || ToPtr2->getInterfaceDecl()))
4235 return ImplicitConversionSequence::Worse;
4236 if (ToPtr2->isObjCIdType() &&
4237 (ToPtr1->isObjCQualifiedIdType() || ToPtr1->getInterfaceDecl()))
4238 return ImplicitConversionSequence::Better;
4239
4240 // A conversion to a non-id object pointer type is better than a
4241 // conversion to a qualified 'id' type
4242 if (ToPtr1->isObjCQualifiedIdType() && ToPtr2->getInterfaceDecl())
4243 return ImplicitConversionSequence::Worse;
4244 if (ToPtr2->isObjCQualifiedIdType() && ToPtr1->getInterfaceDecl())
4245 return ImplicitConversionSequence::Better;
4246
4247 // A conversion to an a non-Class object pointer type or qualified 'Class'
4248 // type is better than a conversion to 'Class'.
4249 if (ToPtr1->isObjCClassType() &&
4250 (ToPtr2->isObjCQualifiedClassType() || ToPtr2->getInterfaceDecl()))
4251 return ImplicitConversionSequence::Worse;
4252 if (ToPtr2->isObjCClassType() &&
4253 (ToPtr1->isObjCQualifiedClassType() || ToPtr1->getInterfaceDecl()))
4254 return ImplicitConversionSequence::Better;
4255
4256 // A conversion to a non-Class object pointer type is better than a
4257 // conversion to a qualified 'Class' type.
4258 if (ToPtr1->isObjCQualifiedClassType() && ToPtr2->getInterfaceDecl())
4259 return ImplicitConversionSequence::Worse;
4260 if (ToPtr2->isObjCQualifiedClassType() && ToPtr1->getInterfaceDecl())
4261 return ImplicitConversionSequence::Better;
4262
4263 // -- "conversion of C* to B* is better than conversion of C* to A*,"
4264 if (S.Context.hasSameType(FromType1, FromType2) &&
4265 !FromPtr1->isObjCIdType() && !FromPtr1->isObjCClassType() &&
4266 (ToAssignLeft != ToAssignRight)) {
4267 if (FromPtr1->isSpecialized()) {
4268 // "conversion of B<A> * to B * is better than conversion of B * to
4269 // C *.
4270 bool IsFirstSame =
4271 FromPtr1->getInterfaceDecl() == ToPtr1->getInterfaceDecl();
4272 bool IsSecondSame =
4273 FromPtr1->getInterfaceDecl() == ToPtr2->getInterfaceDecl();
4274 if (IsFirstSame) {
4275 if (!IsSecondSame)
4276 return ImplicitConversionSequence::Better;
4277 } else if (IsSecondSame)
4278 return ImplicitConversionSequence::Worse;
4279 }
4280 return ToAssignLeft? ImplicitConversionSequence::Worse
4281 : ImplicitConversionSequence::Better;
4282 }
4283
4284 // -- "conversion of B* to A* is better than conversion of C* to A*,"
4285 if (S.Context.hasSameUnqualifiedType(ToType1, ToType2) &&
4286 (FromAssignLeft != FromAssignRight))
4287 return FromAssignLeft? ImplicitConversionSequence::Better
4288 : ImplicitConversionSequence::Worse;
4289 }
4290 }
4291
4292 // Ranking of member-pointer types.
4293 if (SCS1.Second == ICK_Pointer_Member && SCS2.Second == ICK_Pointer_Member &&
4294 FromType1->isMemberPointerType() && FromType2->isMemberPointerType() &&
4295 ToType1->isMemberPointerType() && ToType2->isMemberPointerType()) {
4296 const MemberPointerType * FromMemPointer1 =
4297 FromType1->getAs<MemberPointerType>();
4298 const MemberPointerType * ToMemPointer1 =
4299 ToType1->getAs<MemberPointerType>();
4300 const MemberPointerType * FromMemPointer2 =
4301 FromType2->getAs<MemberPointerType>();
4302 const MemberPointerType * ToMemPointer2 =
4303 ToType2->getAs<MemberPointerType>();
4304 const Type *FromPointeeType1 = FromMemPointer1->getClass();
4305 const Type *ToPointeeType1 = ToMemPointer1->getClass();
4306 const Type *FromPointeeType2 = FromMemPointer2->getClass();
4307 const Type *ToPointeeType2 = ToMemPointer2->getClass();
4308 QualType FromPointee1 = QualType(FromPointeeType1, 0).getUnqualifiedType();
4309 QualType ToPointee1 = QualType(ToPointeeType1, 0).getUnqualifiedType();
4310 QualType FromPointee2 = QualType(FromPointeeType2, 0).getUnqualifiedType();
4311 QualType ToPointee2 = QualType(ToPointeeType2, 0).getUnqualifiedType();
4312 // conversion of A::* to B::* is better than conversion of A::* to C::*,
4313 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) {
4314 if (S.IsDerivedFrom(Loc, ToPointee1, ToPointee2))
4315 return ImplicitConversionSequence::Worse;
4316 else if (S.IsDerivedFrom(Loc, ToPointee2, ToPointee1))
4317 return ImplicitConversionSequence::Better;
4318 }
4319 // conversion of B::* to C::* is better than conversion of A::* to C::*
4320 if (ToPointee1 == ToPointee2 && FromPointee1 != FromPointee2) {
4321 if (S.IsDerivedFrom(Loc, FromPointee1, FromPointee2))
4322 return ImplicitConversionSequence::Better;
4323 else if (S.IsDerivedFrom(Loc, FromPointee2, FromPointee1))
4324 return ImplicitConversionSequence::Worse;
4325 }
4326 }
4327
4328 if (SCS1.Second == ICK_Derived_To_Base) {
4329 // -- conversion of C to B is better than conversion of C to A,
4330 // -- binding of an expression of type C to a reference of type
4331 // B& is better than binding an expression of type C to a
4332 // reference of type A&,
4333 if (S.Context.hasSameUnqualifiedType(FromType1, FromType2) &&
4334 !S.Context.hasSameUnqualifiedType(ToType1, ToType2)) {
4335 if (S.IsDerivedFrom(Loc, ToType1, ToType2))
4336 return ImplicitConversionSequence::Better;
4337 else if (S.IsDerivedFrom(Loc, ToType2, ToType1))
4338 return ImplicitConversionSequence::Worse;
4339 }
4340
4341 // -- conversion of B to A is better than conversion of C to A.
4342 // -- binding of an expression of type B to a reference of type
4343 // A& is better than binding an expression of type C to a
4344 // reference of type A&,
4345 if (!S.Context.hasSameUnqualifiedType(FromType1, FromType2) &&
4346 S.Context.hasSameUnqualifiedType(ToType1, ToType2)) {
4347 if (S.IsDerivedFrom(Loc, FromType2, FromType1))
4348 return ImplicitConversionSequence::Better;
4349 else if (S.IsDerivedFrom(Loc, FromType1, FromType2))
4350 return ImplicitConversionSequence::Worse;
4351 }
4352 }
4353
4354 return ImplicitConversionSequence::Indistinguishable;
4355}
4356
4357/// Determine whether the given type is valid, e.g., it is not an invalid
4358/// C++ class.
4359static bool isTypeValid(QualType T) {
4360 if (CXXRecordDecl *Record = T->getAsCXXRecordDecl())
4361 return !Record->isInvalidDecl();
4362
4363 return true;
4364}
4365
4366/// CompareReferenceRelationship - Compare the two types T1 and T2 to
4367/// determine whether they are reference-related,
4368/// reference-compatible, reference-compatible with added
4369/// qualification, or incompatible, for use in C++ initialization by
4370/// reference (C++ [dcl.ref.init]p4). Neither type can be a reference
4371/// type, and the first type (T1) is the pointee type of the reference
4372/// type being initialized.
4373Sema::ReferenceCompareResult
4374Sema::CompareReferenceRelationship(SourceLocation Loc,
4375 QualType OrigT1, QualType OrigT2,
4376 bool &DerivedToBase,
4377 bool &ObjCConversion,
4378 bool &ObjCLifetimeConversion,
4379 bool &FunctionConversion) {
4380 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-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaOverload.cpp"
, 4381, __PRETTY_FUNCTION__))
4381 "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-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaOverload.cpp"
, 4381, __PRETTY_FUNCTION__))
;
4382 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-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaOverload.cpp"
, 4382, __PRETTY_FUNCTION__))
;
4383
4384 QualType T1 = Context.getCanonicalType(OrigT1);
4385 QualType T2 = Context.getCanonicalType(OrigT2);
4386 Qualifiers T1Quals, T2Quals;
4387 QualType UnqualT1 = Context.getUnqualifiedArrayType(T1, T1Quals);
4388 QualType UnqualT2 = Context.getUnqualifiedArrayType(T2, T2Quals);
4389
4390 // C++ [dcl.init.ref]p4:
4391 // Given types "cv1 T1" and "cv2 T2," "cv1 T1" is
4392 // reference-related to "cv2 T2" if T1 is the same type as T2, or
4393 // T1 is a base class of T2.
4394 DerivedToBase = false;
4395 ObjCConversion = false;
4396 ObjCLifetimeConversion = false;
4397 QualType ConvertedT2;
4398 if (UnqualT1 == UnqualT2) {
4399 // Nothing to do.
4400 } else if (isCompleteType(Loc, OrigT2) &&
4401 isTypeValid(UnqualT1) && isTypeValid(UnqualT2) &&
4402 IsDerivedFrom(Loc, UnqualT2, UnqualT1))
4403 DerivedToBase = true;
4404 else if (UnqualT1->isObjCObjectOrInterfaceType() &&
4405 UnqualT2->isObjCObjectOrInterfaceType() &&
4406 Context.canBindObjCObjectType(UnqualT1, UnqualT2))
4407 ObjCConversion = true;
4408 else if (UnqualT2->isFunctionType() &&
4409 IsFunctionConversion(UnqualT2, UnqualT1, ConvertedT2)) {
4410 // C++1z [dcl.init.ref]p4:
4411 // cv1 T1" is reference-compatible with "cv2 T2" if [...] T2 is "noexcept
4412 // function" and T1 is "function"
4413 //
4414 // We extend this to also apply to 'noreturn', so allow any function
4415 // conversion between function types.
4416 FunctionConversion = true;
4417 return Ref_Compatible;
4418 } else
4419 return Ref_Incompatible;
4420
4421 // At this point, we know that T1 and T2 are reference-related (at
4422 // least).
4423
4424 // If the type is an array type, promote the element qualifiers to the type
4425 // for comparison.
4426 if (isa<ArrayType>(T1) && T1Quals)
4427 T1 = Context.getQualifiedType(UnqualT1, T1Quals);
4428 if (isa<ArrayType>(T2) && T2Quals)
4429 T2 = Context.getQualifiedType(UnqualT2, T2Quals);
4430
4431 // C++ [dcl.init.ref]p4:
4432 // "cv1 T1" is reference-compatible with "cv2 T2" if T1 is
4433 // reference-related to T2 and cv1 is the same cv-qualification
4434 // as, or greater cv-qualification than, cv2. For purposes of
4435 // overload resolution, cases for which cv1 is greater
4436 // cv-qualification than cv2 are identified as
4437 // reference-compatible with added qualification (see 13.3.3.2).
4438 //
4439 // Note that we also require equivalence of Objective-C GC and address-space
4440 // qualifiers when performing these computations, so that e.g., an int in
4441 // address space 1 is not reference-compatible with an int in address
4442 // space 2.
4443 if (T1Quals.getObjCLifetime() != T2Quals.getObjCLifetime() &&
4444 T1Quals.compatiblyIncludesObjCLifetime(T2Quals)) {
4445 if (isNonTrivialObjCLifetimeConversion(T2Quals, T1Quals))
4446 ObjCLifetimeConversion = true;
4447
4448 T1Quals.removeObjCLifetime();
4449 T2Quals.removeObjCLifetime();
4450 }
4451
4452 // MS compiler ignores __unaligned qualifier for references; do the same.
4453 T1Quals.removeUnaligned();
4454 T2Quals.removeUnaligned();
4455
4456 if (T1Quals.compatiblyIncludes(T2Quals))
4457 return Ref_Compatible;
4458 else
4459 return Ref_Related;
4460}
4461
4462/// Look for a user-defined conversion to a value reference-compatible
4463/// with DeclType. Return true if something definite is found.
4464static bool
4465FindConversionForRefInit(Sema &S, ImplicitConversionSequence &ICS,
4466 QualType DeclType, SourceLocation DeclLoc,
4467 Expr *Init, QualType T2, bool AllowRvalues,
4468 bool AllowExplicit) {
4469 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-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaOverload.cpp"
, 4469, __PRETTY_FUNCTION__))
;
4470 CXXRecordDecl *T2RecordDecl
4471 = dyn_cast<CXXRecordDecl>(T2->castAs<RecordType>()->getDecl());
4472
4473 OverloadCandidateSet CandidateSet(
4474 DeclLoc, OverloadCandidateSet::CSK_InitByUserDefinedConversion);
4475 const auto &Conversions = T2RecordDecl->getVisibleConversionFunctions();
4476 for (auto I = Conversions.begin(), E = Conversions.end(); I != E; ++I) {
4477 NamedDecl *D = *I;
4478 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(D->getDeclContext());
4479 if (isa<UsingShadowDecl>(D))
4480 D = cast<UsingShadowDecl>(D)->getTargetDecl();
4481
4482 FunctionTemplateDecl *ConvTemplate
4483 = dyn_cast<FunctionTemplateDecl>(D);
4484 CXXConversionDecl *Conv;
4485 if (ConvTemplate)
4486 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl());
4487 else
4488 Conv = cast<CXXConversionDecl>(D);
4489
4490 // If this is an explicit conversion, and we're not allowed to consider
4491 // explicit conversions, skip it.
4492 if (!AllowExplicit && Conv->isExplicit())
4493 continue;
4494
4495 if (AllowRvalues) {
4496 bool DerivedToBase = false;
4497 bool ObjCConversion = false;
4498 bool ObjCLifetimeConversion = false;
4499 bool FunctionConversion = false;
4500
4501 // If we are initializing an rvalue reference, don't permit conversion
4502 // functions that return lvalues.
4503 if (!ConvTemplate && DeclType->isRValueReferenceType()) {
4504 const ReferenceType *RefType
4505 = Conv->getConversionType()->getAs<LValueReferenceType>();
4506 if (RefType && !RefType->getPointeeType()->isFunctionType())
4507 continue;
4508 }
4509
4510 if (!ConvTemplate &&
4511 S.CompareReferenceRelationship(
4512 DeclLoc,
4513 Conv->getConversionType()
4514 .getNonReferenceType()
4515 .getUnqualifiedType(),
4516 DeclType.getNonReferenceType().getUnqualifiedType(),
4517 DerivedToBase, ObjCConversion, ObjCLifetimeConversion,
4518 FunctionConversion) == Sema::Ref_Incompatible)
4519 continue;
4520 } else {
4521 // If the conversion function doesn't return a reference type,
4522 // it can't be considered for this conversion. An rvalue reference
4523 // is only acceptable if its referencee is a function type.
4524
4525 const ReferenceType *RefType =
4526 Conv->getConversionType()->getAs<ReferenceType>();
4527 if (!RefType ||
4528 (!RefType->isLValueReferenceType() &&
4529 !RefType->getPointeeType()->isFunctionType()))
4530 continue;
4531 }
4532
4533 if (ConvTemplate)
4534 S.AddTemplateConversionCandidate(
4535 ConvTemplate, I.getPair(), ActingDC, Init, DeclType, CandidateSet,
4536 /*AllowObjCConversionOnExplicit=*/false, AllowExplicit);
4537 else
4538 S.AddConversionCandidate(
4539 Conv, I.getPair(), ActingDC, Init, DeclType, CandidateSet,
4540 /*AllowObjCConversionOnExplicit=*/false, AllowExplicit);
4541 }
4542
4543 bool HadMultipleCandidates = (CandidateSet.size() > 1);
4544
4545 OverloadCandidateSet::iterator Best;
4546 switch (CandidateSet.BestViableFunction(S, DeclLoc, Best)) {
4547 case OR_Success:
4548 // C++ [over.ics.ref]p1:
4549 //
4550 // [...] If the parameter binds directly to the result of
4551 // applying a conversion function to the argument
4552 // expression, the implicit conversion sequence is a
4553 // user-defined conversion sequence (13.3.3.1.2), with the
4554 // second standard conversion sequence either an identity
4555 // conversion or, if the conversion function returns an
4556 // entity of a type that is a derived class of the parameter
4557 // type, a derived-to-base Conversion.
4558 if (!Best->FinalConversion.DirectBinding)
4559 return false;
4560
4561 ICS.setUserDefined();
4562 ICS.UserDefined.Before = Best->Conversions[0].Standard;
4563 ICS.UserDefined.After = Best->FinalConversion;
4564 ICS.UserDefined.HadMultipleCandidates = HadMultipleCandidates;
4565 ICS.UserDefined.ConversionFunction = Best->Function;
4566 ICS.UserDefined.FoundConversionFunction = Best->FoundDecl;
4567 ICS.UserDefined.EllipsisConversion = false;
4568 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-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaOverload.cpp"
, 4570, __PRETTY_FUNCTION__))
4569 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-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaOverload.cpp"
, 4570, __PRETTY_FUNCTION__))
4570 "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-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaOverload.cpp"
, 4570, __PRETTY_FUNCTION__))
;
4571 return true;
4572
4573 case OR_Ambiguous:
4574 ICS.setAmbiguous();
4575 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin();
4576 Cand != CandidateSet.end(); ++Cand)
4577 if (Cand->Best)
4578 ICS.Ambiguous.addConversion(Cand->FoundDecl, Cand->Function);
4579 return true;
4580
4581 case OR_No_Viable_Function:
4582 case OR_Deleted:
4583 // There was no suitable conversion, or we found a deleted
4584 // conversion; continue with other checks.
4585 return false;
4586 }
4587
4588 llvm_unreachable("Invalid OverloadResult!")::llvm::llvm_unreachable_internal("Invalid OverloadResult!", "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaOverload.cpp"
, 4588)
;
4589}
4590
4591/// Compute an implicit conversion sequence for reference
4592/// initialization.
4593static ImplicitConversionSequence
4594TryReferenceInit(Sema &S, Expr *Init, QualType DeclType,
4595 SourceLocation DeclLoc,
4596 bool SuppressUserConversions,
4597 bool AllowExplicit) {
4598 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-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaOverload.cpp"
, 4598, __PRETTY_FUNCTION__))
;
4599
4600 // Most paths end in a failed conversion.
4601 ImplicitConversionSequence ICS;
4602 ICS.setBad(BadConversionSequence::no_conversion, Init, DeclType);
4603
4604 QualType T1 = DeclType->castAs<ReferenceType>()->getPointeeType();
4605 QualType T2 = Init->getType();
4606
4607 // If the initializer is the address of an overloaded function, try
4608 // to resolve the overloaded function. If all goes well, T2 is the
4609 // type of the resulting function.
4610 if (S.Context.getCanonicalType(T2) == S.Context.OverloadTy) {
4611 DeclAccessPair Found;
4612 if (FunctionDecl *Fn = S.ResolveAddressOfOverloadedFunction(Init, DeclType,
4613 false, Found))
4614 T2 = Fn->getType();
4615 }
4616
4617 // Compute some basic properties of the types and the initializer.
4618 bool isRValRef = DeclType->isRValueReferenceType();
4619 bool DerivedToBase = false;
4620 bool ObjCConversion = false;
4621 bool ObjCLifetimeConversion = false;
4622 bool FunctionConversion = false;
4623 Expr::Classification InitCategory = Init->Classify(S.Context);
4624 Sema::ReferenceCompareResult RefRelationship = S.CompareReferenceRelationship(
4625 DeclLoc, T1, T2, DerivedToBase, ObjCConversion, ObjCLifetimeConversion,
4626 FunctionConversion);
4627
4628 // C++0x [dcl.init.ref]p5:
4629 // A reference to type "cv1 T1" is initialized by an expression
4630 // of type "cv2 T2" as follows:
4631
4632 // -- If reference is an lvalue reference and the initializer expression
4633 if (!isRValRef) {
4634 // -- is an lvalue (but is not a bit-field), and "cv1 T1" is
4635 // reference-compatible with "cv2 T2," or
4636 //
4637 // Per C++ [over.ics.ref]p4, we don't check the bit-field property here.
4638 if (InitCategory.isLValue() && RefRelationship == Sema::Ref_Compatible) {
4639 // C++ [over.ics.ref]p1:
4640 // When a parameter of reference type binds directly (8.5.3)
4641 // to an argument expression, the implicit conversion sequence
4642 // is the identity conversion, unless the argument expression
4643 // has a type that is a derived class of the parameter type,
4644 // in which case the implicit conversion sequence is a
4645 // derived-to-base Conversion (13.3.3.1).
4646 ICS.setStandard();
4647 ICS.Standard.First = ICK_Identity;
4648 ICS.Standard.Second = DerivedToBase? ICK_Derived_To_Base
4649 : ObjCConversion? ICK_Compatible_Conversion
4650 : ICK_Identity;
4651 ICS.Standard.Third = ICK_Identity;
4652 ICS.Standard.FromTypePtr = T2.getAsOpaquePtr();
4653 ICS.Standard.setToType(0, T2);
4654 ICS.Standard.setToType(1, T1);
4655 ICS.Standard.setToType(2, T1);
4656 ICS.Standard.ReferenceBinding = true;
4657 ICS.Standard.DirectBinding = true;
4658 ICS.Standard.IsLvalueReference = !isRValRef;
4659 ICS.Standard.BindsToFunctionLvalue = T2->isFunctionType();
4660 ICS.Standard.BindsToRvalue = false;
4661 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier = false;
4662 ICS.Standard.ObjCLifetimeConversionBinding = ObjCLifetimeConversion;
4663 ICS.Standard.CopyConstructor = nullptr;
4664 ICS.Standard.DeprecatedStringLiteralToCharPtr = false;
4665
4666 // Nothing more to do: the inaccessibility/ambiguity check for
4667 // derived-to-base conversions is suppressed when we're
4668 // computing the implicit conversion sequence (C++
4669 // [over.best.ics]p2).
4670 return ICS;
4671 }
4672
4673 // -- has a class type (i.e., T2 is a class type), where T1 is
4674 // not reference-related to T2, and can be implicitly
4675 // converted to an lvalue of type "cv3 T3," where "cv1 T1"
4676 // is reference-compatible with "cv3 T3" 92) (this
4677 // conversion is selected by enumerating the applicable
4678 // conversion functions (13.3.1.6) and choosing the best
4679 // one through overload resolution (13.3)),
4680 if (!SuppressUserConversions && T2->isRecordType() &&
4681 S.isCompleteType(DeclLoc, T2) &&
4682 RefRelationship == Sema::Ref_Incompatible) {
4683 if (FindConversionForRefInit(S, ICS, DeclType, DeclLoc,
4684 Init, T2, /*AllowRvalues=*/false,
4685 AllowExplicit))
4686 return ICS;
4687 }
4688 }
4689
4690 // -- Otherwise, the reference shall be an lvalue reference to a
4691 // non-volatile const type (i.e., cv1 shall be const), or the reference
4692 // shall be an rvalue reference.
4693 if (!isRValRef && (!T1.isConstQualified() || T1.isVolatileQualified()))
4694 return ICS;
4695
4696 // -- If the initializer expression
4697 //
4698 // -- is an xvalue, class prvalue, array prvalue or function
4699 // lvalue and "cv1 T1" is reference-compatible with "cv2 T2", or
4700 if (RefRelationship == Sema::Ref_Compatible &&
4701 (InitCategory.isXValue() ||
4702 (InitCategory.isPRValue() && (T2->isRecordType() || T2->isArrayType())) ||
4703 (InitCategory.isLValue() && T2->isFunctionType()))) {
4704 ICS.setStandard();
4705 ICS.Standard.First = ICK_Identity;
4706 ICS.Standard.Second = DerivedToBase? ICK_Derived_To_Base
4707 : ObjCConversion? ICK_Compatible_Conversion
4708 : ICK_Identity;
4709 ICS.Standard.Third = ICK_Identity;
4710 ICS.Standard.FromTypePtr = T2.getAsOpaquePtr();
4711 ICS.Standard.setToType(0, T2);
4712 ICS.Standard.setToType(1, T1);
4713 ICS.Standard.setToType(2, T1);
4714 ICS.Standard.ReferenceBinding = true;
4715 // In C++0x, this is always a direct binding. In C++98/03, it's a direct
4716 // binding unless we're binding to a class prvalue.
4717 // Note: Although xvalues wouldn't normally show up in C++98/03 code, we
4718 // allow the use of rvalue references in C++98/03 for the benefit of
4719 // standard library implementors; therefore, we need the xvalue check here.
4720 ICS.Standard.DirectBinding =
4721 S.getLangOpts().CPlusPlus11 ||
4722 !(InitCategory.isPRValue() || T2->isRecordType());
4723 ICS.Standard.IsLvalueReference = !isRValRef;
4724 ICS.Standard.BindsToFunctionLvalue = T2->isFunctionType();
4725 ICS.Standard.BindsToRvalue = InitCategory.isRValue();
4726 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier = false;
4727 ICS.Standard.ObjCLifetimeConversionBinding = ObjCLifetimeConversion;
4728 ICS.Standard.CopyConstructor = nullptr;
4729 ICS.Standard.DeprecatedStringLiteralToCharPtr = false;
4730 return ICS;
4731 }
4732
4733 // -- has a class type (i.e., T2 is a class type), where T1 is not
4734 // reference-related to T2, and can be implicitly converted to
4735 // an xvalue, class prvalue, or function lvalue of type
4736 // "cv3 T3", where "cv1 T1" is reference-compatible with
4737 // "cv3 T3",
4738 //
4739 // then the reference is bound to the value of the initializer
4740 // expression in the first case and to the result of the conversion
4741 // in the second case (or, in either case, to an appropriate base
4742 // class subobject).
4743 if (!SuppressUserConversions && RefRelationship == Sema::Ref_Incompatible &&
4744 T2->isRecordType() && S.isCompleteType(DeclLoc, T2) &&
4745 FindConversionForRefInit(S, ICS, DeclType, DeclLoc,
4746 Init, T2, /*AllowRvalues=*/true,
4747 AllowExplicit)) {
4748 // In the second case, if the reference is an rvalue reference
4749 // and the second standard conversion sequence of the
4750 // user-defined conversion sequence includes an lvalue-to-rvalue
4751 // conversion, the program is ill-formed.
4752 if (ICS.isUserDefined() && isRValRef &&
4753 ICS.UserDefined.After.First == ICK_Lvalue_To_Rvalue)
4754 ICS.setBad(BadConversionSequence::no_conversion, Init, DeclType);
4755
4756 return ICS;
4757 }
4758
4759 // A temporary of function type cannot be created; don't even try.
4760 if (T1->isFunctionType())
4761 return ICS;
4762
4763 // -- Otherwise, a temporary of type "cv1 T1" is created and
4764 // initialized from the initializer expression using the
4765 // rules for a non-reference copy initialization (8.5). The
4766 // reference is then bound to the temporary. If T1 is
4767 // reference-related to T2, cv1 must be the same
4768 // cv-qualification as, or greater cv-qualification than,
4769 // cv2; otherwise, the program is ill-formed.
4770 if (RefRelationship == Sema::Ref_Related) {
4771 // If cv1 == cv2 or cv1 is a greater cv-qualified than cv2, then
4772 // we would be reference-compatible or reference-compatible with
4773 // added qualification. But that wasn't the case, so the reference
4774 // initialization fails.
4775 //
4776 // Note that we only want to check address spaces and cvr-qualifiers here.
4777 // ObjC GC, lifetime and unaligned qualifiers aren't important.
4778 Qualifiers T1Quals = T1.getQualifiers();
4779 Qualifiers T2Quals = T2.getQualifiers();
4780 T1Quals.removeObjCGCAttr();
4781 T1Quals.removeObjCLifetime();
4782 T2Quals.removeObjCGCAttr();
4783 T2Quals.removeObjCLifetime();
4784 // MS compiler ignores __unaligned qualifier for references; do the same.
4785 T1Quals.removeUnaligned();
4786 T2Quals.removeUnaligned();
4787 if (!T1Quals.compatiblyIncludes(T2Quals))
4788 return ICS;
4789 }
4790
4791 // If at least one of the types is a class type, the types are not
4792 // related, and we aren't allowed any user conversions, the
4793 // reference binding fails. This case is important for breaking
4794 // recursion, since TryImplicitConversion below will attempt to
4795 // create a temporary through the use of a copy constructor.
4796 if (SuppressUserConversions && RefRelationship == Sema::Ref_Incompatible &&
4797 (T1->isRecordType() || T2->isRecordType()))
4798 return ICS;
4799
4800 // If T1 is reference-related to T2 and the reference is an rvalue
4801 // reference, the initializer expression shall not be an lvalue.
4802 if (RefRelationship >= Sema::Ref_Related &&
4803 isRValRef && Init->Classify(S.Context).isLValue())
4804 return ICS;
4805
4806 // C++ [over.ics.ref]p2:
4807 // When a parameter of reference type is not bound directly to
4808 // an argument expression, the conversion sequence is the one
4809 // required to convert the argument expression to the
4810 // underlying type of the reference according to
4811 // 13.3.3.1. Conceptually, this conversion sequence corresponds
4812 // to copy-initializing a temporary of the underlying type with
4813 // the argument expression. Any difference in top-level
4814 // cv-qualification is subsumed by the initialization itself
4815 // and does not constitute a conversion.
4816 ICS = TryImplicitConversion(S, Init, T1, SuppressUserConversions,
4817 /*AllowExplicit=*/false,
4818 /*InOverloadResolution=*/false,
4819 /*CStyle=*/false,
4820 /*AllowObjCWritebackConversion=*/false,
4821 /*AllowObjCConversionOnExplicit=*/false);
4822
4823 // Of course, that's still a reference binding.
4824 if (ICS.isStandard()) {
4825 ICS.Standard.ReferenceBinding = true;
4826 ICS.Standard.IsLvalueReference = !isRValRef;
4827 ICS.Standard.BindsToFunctionLvalue = false;
4828 ICS.Standard.BindsToRvalue = true;
4829 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier = false;
4830 ICS.Standard.ObjCLifetimeConversionBinding = false;
4831 } else if (ICS.isUserDefined()) {
4832 const ReferenceType *LValRefType =
4833 ICS.UserDefined.ConversionFunction->getReturnType()
4834 ->getAs<LValueReferenceType>();
4835
4836 // C++ [over.ics.ref]p3:
4837 // Except for an implicit object parameter, for which see 13.3.1, a
4838 // standard conversion sequence cannot be formed if it requires [...]
4839 // binding an rvalue reference to an lvalue other than a function
4840 // lvalue.
4841 // Note that the function case is not possible here.
4842 if (DeclType->isRValueReferenceType() && LValRefType) {
4843 // FIXME: This is the wrong BadConversionSequence. The problem is binding
4844 // an rvalue reference to a (non-function) lvalue, not binding an lvalue
4845 // reference to an rvalue!
4846 ICS.setBad(BadConversionSequence::lvalue_ref_to_rvalue, Init, DeclType);
4847 return ICS;
4848 }
4849
4850 ICS.UserDefined.After.ReferenceBinding = true;
4851 ICS.UserDefined.After.IsLvalueReference = !isRValRef;
4852 ICS.UserDefined.After.BindsToFunctionLvalue = false;
4853 ICS.UserDefined.After.BindsToRvalue = !LValRefType;
4854 ICS.UserDefined.After.BindsImplicitObjectArgumentWithoutRefQualifier = false;
4855 ICS.UserDefined.After.ObjCLifetimeConversionBinding = false;
4856 }
4857
4858 return ICS;
4859}
4860
4861static ImplicitConversionSequence
4862TryCopyInitialization(Sema &S, Expr *From, QualType ToType,
4863 bool SuppressUserConversions,
4864 bool InOverloadResolution,
4865 bool AllowObjCWritebackConversion,
4866 bool AllowExplicit = false);
4867
4868/// TryListConversion - Try to copy-initialize a value of type ToType from the
4869/// initializer list From.
4870static ImplicitConversionSequence
4871TryListConversion(Sema &S, InitListExpr *From, QualType ToType,
4872 bool SuppressUserConversions,
4873 bool InOverloadResolution,
4874 bool AllowObjCWritebackConversion) {
4875 // C++11 [over.ics.list]p1:
4876 // When an argument is an initializer list, it is not an expression and
4877 // special rules apply for converting it to a parameter type.
4878
4879 ImplicitConversionSequence Result;
4880 Result.setBad(BadConversionSequence::no_conversion, From, ToType);
4881
4882 // We need a complete type for what follows. Incomplete types can never be
4883 // initialized from init lists.
4884 if (!S.isCompleteType(From->getBeginLoc(), ToType))
4885 return Result;
4886
4887 // Per DR1467:
4888 // If the parameter type is a class X and the initializer list has a single
4889 // element of type cv U, where U is X or a class derived from X, the
4890 // implicit conversion sequence is the one required to convert the element
4891 // to the parameter type.
4892 //
4893 // Otherwise, if the parameter type is a character array [... ]
4894 // and the initializer list has a single element that is an
4895 // appropriately-typed string literal (8.5.2 [dcl.init.string]), the
4896 // implicit conversion sequence is the identity conversion.
4897 if (From->getNumInits() == 1) {
4898 if (ToType->isRecordType()) {
4899 QualType InitType = From->getInit(0)->getType();
4900 if (S.Context.hasSameUnqualifiedType(InitType, ToType) ||
4901 S.IsDerivedFrom(From->getBeginLoc(), InitType, ToType))
4902 return TryCopyInitialization(S, From->getInit(0), ToType,
4903 SuppressUserConversions,
4904 InOverloadResolution,
4905 AllowObjCWritebackConversion);
4906 }
4907 // FIXME: Check the other conditions here: array of character type,
4908 // initializer is a string literal.
4909 if (ToType->isArrayType()) {
4910 InitializedEntity Entity =
4911 InitializedEntity::InitializeParameter(S.Context, ToType,
4912 /*Consumed=*/false);
4913 if (S.CanPerformCopyInitialization(Entity, From)) {
4914 Result.setStandard();
4915 Result.Standard.setAsIdentityConversion();
4916 Result.Standard.setFromType(ToType);
4917 Result.Standard.setAllToTypes(ToType);
4918 return Result;
4919 }
4920 }
4921 }
4922
4923 // C++14 [over.ics.list]p2: Otherwise, if the parameter type [...] (below).
4924 // C++11 [over.ics.list]p2:
4925 // If the parameter type is std::initializer_list<X> or "array of X" and
4926 // all the elements can be implicitly converted to X, the implicit
4927 // conversion sequence is the worst conversion necessary to convert an
4928 // element of the list to X.
4929 //
4930 // C++14 [over.ics.list]p3:
4931 // Otherwise, if the parameter type is "array of N X", if the initializer
4932 // list has exactly N elements or if it has fewer than N elements and X is
4933 // default-constructible, and if all the elements of the initializer list
4934 // can be implicitly converted to X, the implicit conversion sequence is
4935 // the worst conversion necessary to convert an element of the list to X.
4936 //
4937 // FIXME: We're missing a lot of these checks.
4938 bool toStdInitializerList = false;
4939 QualType X;
4940 if (ToType->isArrayType())
4941 X = S.Context.getAsArrayType(ToType)->getElementType();
4942 else
4943 toStdInitializerList = S.isStdInitializerList(ToType, &X);
4944 if (!X.isNull()) {
4945 for (unsigned i = 0, e = From->getNumInits(); i < e; ++i) {
4946 Expr *Init = From->getInit(i);
4947 ImplicitConversionSequence ICS =
4948 TryCopyInitialization(S, Init, X, SuppressUserConversions,
4949 InOverloadResolution,
4950 AllowObjCWritebackConversion);
4951 // If a single element isn't convertible, fail.
4952 if (ICS.isBad()) {
4953 Result = ICS;
4954 break;
4955 }
4956 // Otherwise, look for the worst conversion.
4957 if (Result.isBad() || CompareImplicitConversionSequences(
4958 S, From->getBeginLoc(), ICS, Result) ==
4959 ImplicitConversionSequence::Worse)
4960 Result = ICS;
4961 }
4962
4963 // For an empty list, we won't have computed any conversion sequence.
4964 // Introduce the identity conversion sequence.
4965 if (From->getNumInits() == 0) {
4966 Result.setStandard();
4967 Result.Standard.setAsIdentityConversion();
4968 Result.Standard.setFromType(ToType);
4969 Result.Standard.setAllToTypes(ToType);
4970 }
4971
4972 Result.setStdInitializerListElement(toStdInitializerList);
4973 return Result;
4974 }
4975
4976 // C++14 [over.ics.list]p4:
4977 // C++11 [over.ics.list]p3:
4978 // Otherwise, if the parameter is a non-aggregate class X and overload
4979 // resolution chooses a single best constructor [...] the implicit
4980 // conversion sequence is a user-defined conversion sequence. If multiple
4981 // constructors are viable but none is better than the others, the
4982 // implicit conversion sequence is a user-defined conversion sequence.
4983 if (ToType->isRecordType() && !ToType->isAggregateType()) {
4984 // This function can deal with initializer lists.
4985 return TryUserDefinedConversion(S, From, ToType, SuppressUserConversions,
4986 /*AllowExplicit=*/false,
4987 InOverloadResolution, /*CStyle=*/false,
4988 AllowObjCWritebackConversion,
4989 /*AllowObjCConversionOnExplicit=*/false);
4990 }
4991
4992 // C++14 [over.ics.list]p5:
4993 // C++11 [over.ics.list]p4:
4994 // Otherwise, if the parameter has an aggregate type which can be
4995 // initialized from the initializer list [...] the implicit conversion
4996 // sequence is a user-defined conversion sequence.
4997 if (ToType->isAggregateType()) {
4998 // Type is an aggregate, argument is an init list. At this point it comes
4999 // down to checking whether the initialization works.
5000 // FIXME: Find out whether this parameter is consumed or not.
5001 InitializedEntity Entity =
5002 InitializedEntity::InitializeParameter(S.Context, ToType,
5003 /*Consumed=*/false);
5004 if (S.CanPerformAggregateInitializationForOverloadResolution(Entity,
5005 From)) {
5006 Result.setUserDefined();
5007 Result.UserDefined.Before.setAsIdentityConversion();
5008 // Initializer lists don't have a type.
5009 Result.UserDefined.Before.setFromType(QualType());
5010 Result.UserDefined.Before.setAllToTypes(QualType());
5011
5012 Result.UserDefined.After.setAsIdentityConversion();
5013 Result.UserDefined.After.setFromType(ToType);
5014 Result.UserDefined.After.setAllToTypes(ToType);
5015 Result.UserDefined.ConversionFunction = nullptr;
5016 }
5017 return Result;
5018 }
5019
5020 // C++14 [over.ics.list]p6:
5021 // C++11 [over.ics.list]p5:
5022 // Otherwise, if the parameter is a reference, see 13.3.3.1.4.
5023 if (ToType->isReferenceType()) {
5024 // The standard is notoriously unclear here, since 13.3.3.1.4 doesn't
5025 // mention initializer lists in any way. So we go by what list-
5026 // initialization would do and try to extrapolate from that.
5027
5028 QualType T1 = ToType->castAs<ReferenceType>()->getPointeeType();
5029
5030 // If the initializer list has a single element that is reference-related
5031 // to the parameter type, we initialize the reference from that.
5032 if (From->getNumInits() == 1) {
5033 Expr *Init = From->getInit(0);
5034
5035 QualType T2 = Init->getType();
5036
5037 // If the initializer is the address of an overloaded function, try
5038 // to resolve the overloaded function. If all goes well, T2 is the
5039 // type of the resulting function.
5040 if (S.Context.getCanonicalType(T2) == S.Context.OverloadTy) {
5041 DeclAccessPair Found;
5042 if (FunctionDecl *Fn = S.ResolveAddressOfOverloadedFunction(
5043 Init, ToType, false, Found))
5044 T2 = Fn->getType();
5045 }
5046
5047 // Compute some basic properties of the types and the initializer.
5048 bool dummy1 = false;
5049 bool dummy2 = false;
5050 bool dummy3 = false;
5051 bool dummy4 = false;
5052 Sema::ReferenceCompareResult RefRelationship =
5053 S.CompareReferenceRelationship(From->getBeginLoc(), T1, T2, dummy1,
5054 dummy2, dummy3, dummy4);
5055
5056 if (RefRelationship >= Sema::Ref_Related) {
5057 return TryReferenceInit(S, Init, ToType, /*FIXME*/ From->getBeginLoc(),
5058 SuppressUserConversions,
5059 /*AllowExplicit=*/false);
5060 }
5061 }
5062
5063 // Otherwise, we bind the reference to a temporary created from the
5064 // initializer list.
5065 Result = TryListConversion(S, From, T1, SuppressUserConversions,
5066 InOverloadResolution,
5067 AllowObjCWritebackConversion);
5068 if (Result.isFailure())
5069 return Result;
5070 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-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaOverload.cpp"
, 5071, __PRETTY_FUNCTION__))
5071 "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-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaOverload.cpp"
, 5071, __PRETTY_FUNCTION__))
;
5072
5073 // Can we even bind to a temporary?
5074 if (ToType->isRValueReferenceType() ||
5075 (T1.isConstQualified() && !T1.isVolatileQualified())) {
5076 StandardConversionSequence &SCS = Result.isStandard() ? Result.Standard :
5077 Result.UserDefined.After;
5078 SCS.ReferenceBinding = true;
5079 SCS.IsLvalueReference = ToType->isLValueReferenceType();
5080 SCS.BindsToRvalue = true;
5081 SCS.BindsToFunctionLvalue = false;
5082 SCS.BindsImplicitObjectArgumentWithoutRefQualifier = false;
5083 SCS.ObjCLifetimeConversionBinding = false;
5084 } else
5085 Result.setBad(BadConversionSequence::lvalue_ref_to_rvalue,
5086 From, ToType);
5087 return Result;
5088 }
5089
5090 // C++14 [over.ics.list]p7:
5091 // C++11 [over.ics.list]p6:
5092 // Otherwise, if the parameter type is not a class:
5093 if (!ToType->isRecordType()) {
5094 // - if the initializer list has one element that is not itself an
5095 // initializer list, the implicit conversion sequence is the one
5096 // required to convert the element to the parameter type.
5097 unsigned NumInits = From->getNumInits();
5098 if (NumInits == 1 && !isa<InitListExpr>(From->getInit(0)))
5099 Result = TryCopyInitialization(S, From->getInit(0), ToType,
5100 SuppressUserConversions,
5101 InOverloadResolution,
5102 AllowObjCWritebackConversion);
5103 // - if the initializer list has no elements, the implicit conversion
5104 // sequence is the identity conversion.
5105 else if (NumInits == 0) {
5106 Result.setStandard();
5107 Result.Standard.setAsIdentityConversion();
5108 Result.Standard.setFromType(ToType);
5109 Result.Standard.setAllToTypes(ToType);
5110 }
5111 return Result;
5112 }
5113
5114 // C++14 [over.ics.list]p8:
5115 // C++11 [over.ics.list]p7:
5116 // In all cases other than those enumerated above, no conversion is possible
5117 return Result;
5118}
5119
5120/// TryCopyInitialization - Try to copy-initialize a value of type
5121/// ToType from the expression From. Return the implicit conversion
5122/// sequence required to pass this argument, which may be a bad
5123/// conversion sequence (meaning that the argument cannot be passed to
5124/// a parameter of this type). If @p SuppressUserConversions, then we
5125/// do not permit any user-defined conversion sequences.
5126static ImplicitConversionSequence
5127TryCopyInitialization(Sema &S, Expr *From, QualType ToType,
5128 bool SuppressUserConversions,
5129 bool InOverloadResolution,
5130 bool AllowObjCWritebackConversion,
5131 bool AllowExplicit) {
5132 if (InitListExpr *FromInitList = dyn_cast<InitListExpr>(From))
5133 return TryListConversion(S, FromInitList, ToType, SuppressUserConversions,
5134 InOverloadResolution,AllowObjCWritebackConversion);
5135
5136 if (ToType->isReferenceType())
5137 return TryReferenceInit(S, From, ToType,
5138 /*FIXME:*/ From->getBeginLoc(),
5139 SuppressUserConversions, AllowExplicit);
5140
5141 return TryImplicitConversion(S, From, ToType,
5142 SuppressUserConversions,
5143 /*AllowExplicit=*/false,
5144 InOverloadResolution,
5145 /*CStyle=*/false,
5146 AllowObjCWritebackConversion,
5147 /*AllowObjCConversionOnExplicit=*/false);
5148}
5149
5150static bool TryCopyInitialization(const CanQualType FromQTy,
5151 const CanQualType ToQTy,
5152 Sema &S,
5153 SourceLocation Loc,
5154 ExprValueKind FromVK) {
5155 OpaqueValueExpr TmpExpr(Loc, FromQTy, FromVK);
5156 ImplicitConversionSequence ICS =
5157 TryCopyInitialization(S, &TmpExpr, ToQTy, true, true, false);
5158
5159 return !ICS.isBad();
5160}
5161
5162/// TryObjectArgumentInitialization - Try to initialize the object
5163/// parameter of the given member function (@c Method) from the
5164/// expression @p From.
5165static ImplicitConversionSequence
5166TryObjectArgumentInitialization(Sema &S, SourceLocation Loc, QualType FromType,
5167 Expr::Classification FromClassification,
5168 CXXMethodDecl *Method,
5169 CXXRecordDecl *ActingContext) {
5170 QualType ClassType = S.Context.getTypeDeclType(ActingContext);
5171 // [class.dtor]p2: A destructor can be invoked for a const, volatile or
5172 // const volatile object.
5173 Qualifiers Quals = Method->getMethodQualifiers();
5174 if (isa<CXXDestructorDecl>(Method)) {
5175 Quals.addConst();
5176 Quals.addVolatile();
5177 }
5178
5179 QualType ImplicitParamType = S.Context.getQualifiedType(ClassType, Quals);
5180
5181 // Set up the conversion sequence as a "bad" conversion, to allow us
5182 // to exit early.
5183 ImplicitConversionSequence ICS;
5184
5185 // We need to have an object of class type.
5186 if (const PointerType *PT = FromType->getAs<PointerType>()) {
5187 FromType = PT->getPointeeType();
5188
5189 // When we had a pointer, it's implicitly dereferenced, so we
5190 // better have an lvalue.
5191 assert(FromClassification.isLValue())((FromClassification.isLValue()) ? static_cast<void> (0
) : __assert_fail ("FromClassification.isLValue()", "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaOverload.cpp"
, 5191, __PRETTY_FUNCTION__))
;
5192 }
5193
5194 assert(FromType->isRecordType())((FromType->isRecordType()) ? static_cast<void> (0) :
__assert_fail ("FromType->isRecordType()", "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaOverload.cpp"
, 5194, __PRETTY_FUNCTION__))
;
5195
5196 // C++0x [over.match.funcs]p4:
5197 // For non-static member functions, the type of the implicit object
5198 // parameter is
5199 //
5200 // - "lvalue reference to cv X" for functions declared without a
5201 // ref-qualifier or with the & ref-qualifier
5202 // - "rvalue reference to cv X" for functions declared with the &&
5203 // ref-qualifier
5204 //
5205 // where X is the class of which the function is a member and cv is the
5206 // cv-qualification on the member function declaration.
5207 //
5208 // However, when finding an implicit conversion sequence for the argument, we
5209 // are not allowed to perform user-defined conversions
5210 // (C++ [over.match.funcs]p5). We perform a simplified version of
5211 // reference binding here, that allows class rvalues to bind to
5212 // non-constant references.
5213
5214 // First check the qualifiers.
5215 QualType FromTypeCanon = S.Context.getCanonicalType(FromType);
5216 if (ImplicitParamType.getCVRQualifiers()
5217 != FromTypeCanon.getLocalCVRQualifiers() &&
5218 !ImplicitParamType.isAtLeastAsQualifiedAs(FromTypeCanon)) {
5219 ICS.setBad(BadConversionSequence::bad_qualifiers,
5220 FromType, ImplicitParamType);
5221 return ICS;
5222 }
5223
5224 if (FromTypeCanon.getQualifiers().hasAddressSpace()) {
5225 Qualifiers QualsImplicitParamType = ImplicitParamType.getQualifiers();
5226 Qualifiers QualsFromType = FromTypeCanon.getQualifiers();
5227 if (!QualsImplicitParamType.isAddressSpaceSupersetOf(QualsFromType)) {
5228 ICS.setBad(BadConversionSequence::bad_qualifiers,
5229 FromType, ImplicitParamType);
5230 return ICS;
5231 }
5232 }
5233
5234 // Check that we have either the same type or a derived type. It
5235 // affects the conversion rank.
5236 QualType ClassTypeCanon = S.Context.getCanonicalType(ClassType);
5237 ImplicitConversionKind SecondKind;
5238 if (ClassTypeCanon == FromTypeCanon.getLocalUnqualifiedType()) {
5239 SecondKind = ICK_Identity;
5240 } else if (S.IsDerivedFrom(Loc, FromType, ClassType))
5241 SecondKind = ICK_Derived_To_Base;
5242 else {
5243 ICS.setBad(BadConversionSequence::unrelated_class,
5244 FromType, ImplicitParamType);
5245 return ICS;
5246 }
5247
5248 // Check the ref-qualifier.
5249 switch (Method->getRefQualifier()) {
5250 case RQ_None:
5251 // Do nothing; we don't care about lvalueness or rvalueness.
5252 break;
5253
5254 case RQ_LValue:
5255 if (!FromClassification.isLValue() && !Quals.hasOnlyConst()) {
5256 // non-const lvalue reference cannot bind to an rvalue
5257 ICS.setBad(BadConversionSequence::lvalue_ref_to_rvalue, FromType,
5258 ImplicitParamType);
5259 return ICS;
5260 }
5261 break;
5262
5263 case RQ_RValue:
5264 if (!FromClassification.isRValue()) {
5265 // rvalue reference cannot bind to an lvalue
5266 ICS.setBad(BadConversionSequence::rvalue_ref_to_lvalue, FromType,
5267 ImplicitParamType);
5268 return ICS;
5269 }
5270 break;
5271 }
5272
5273 // Success. Mark this as a reference binding.
5274 ICS.setStandard();
5275 ICS.Standard.setAsIdentityConversion();
5276 ICS.Standard.Second = SecondKind;
5277 ICS.Standard.setFromType(FromType);
5278 ICS.Standard.setAllToTypes(ImplicitParamType);
5279 ICS.Standard.ReferenceBinding = true;
5280 ICS.Standard.DirectBinding = true;
5281 ICS.Standard.IsLvalueReference = Method->getRefQualifier() != RQ_RValue;
5282 ICS.Standard.BindsToFunctionLvalue = false;
5283 ICS.Standard.BindsToRvalue = FromClassification.isRValue();
5284 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier
5285 = (Method->getRefQualifier() == RQ_None);
5286 return ICS;
5287}
5288
5289/// PerformObjectArgumentInitialization - Perform initialization of
5290/// the implicit object parameter for the given Method with the given
5291/// expression.
5292ExprResult
5293Sema::PerformObjectArgumentInitialization(Expr *From,
5294 NestedNameSpecifier *Qualifier,
5295 NamedDecl *FoundDecl,
5296 CXXMethodDecl *Method) {
5297 QualType FromRecordType, DestType;
5298 QualType ImplicitParamRecordType =
5299 Method->getThisType()->castAs<PointerType>()->getPointeeType();
5300
5301 Expr::Classification FromClassification;
5302 if (const PointerType *PT = From->getType()->getAs<PointerType>()) {
5303 FromRecordType = PT->getPointeeType();
5304 DestType = Method->getThisType();
5305 FromClassification = Expr::Classification::makeSimpleLValue();
5306 } else {
5307 FromRecordType = From->getType();
5308 DestType = ImplicitParamRecordType;
5309 FromClassification = From->Classify(Context);
5310
5311 // When performing member access on an rvalue, materialize a temporary.
5312 if (From->isRValue()) {
5313 From = CreateMaterializeTemporaryExpr(FromRecordType, From,
5314 Method->getRefQualifier() !=
5315 RefQualifierKind::RQ_RValue);
5316 }
5317 }
5318
5319 // Note that we always use the true parent context when performing
5320 // the actual argument initialization.
5321 ImplicitConversionSequence ICS = TryObjectArgumentInitialization(
5322 *this, From->getBeginLoc(), From->getType(), FromClassification, Method,
5323 Method->getParent());
5324 if (ICS.isBad()) {
5325 switch (ICS.Bad.Kind) {
5326 case BadConversionSequence::bad_qualifiers: {
5327 Qualifiers FromQs = FromRecordType.getQualifiers();
5328 Qualifiers ToQs = DestType.getQualifiers();
5329 unsigned CVR = FromQs.getCVRQualifiers() & ~ToQs.getCVRQualifiers();
5330 if (CVR) {
5331 Diag(From->getBeginLoc(), diag::err_member_function_call_bad_cvr)
5332 << Method->getDeclName() << FromRecordType << (CVR - 1)
5333 << From->getSourceRange();
5334 Diag(Method->getLocation(), diag::note_previous_decl)
5335 << Method->getDeclName();
5336 return ExprError();
5337 }
5338 break;
5339 }
5340
5341 case BadConversionSequence::lvalue_ref_to_rvalue:
5342 case BadConversionSequence::rvalue_ref_to_lvalue: {
5343 bool IsRValueQualified =
5344 Method->getRefQualifier() == RefQualifierKind::RQ_RValue;
5345 Diag(From->getBeginLoc(), diag::err_member_function_call_bad_ref)
5346 << Method->getDeclName() << FromClassification.isRValue()
5347 << IsRValueQualified;
5348 Diag(Method->getLocation(), diag::note_previous_decl)
5349 << Method->getDeclName();
5350 return ExprError();
5351 }
5352
5353 case BadConversionSequence::no_conversion:
5354 case BadConversionSequence::unrelated_class:
5355 break;
5356 }
5357
5358 return Diag(From->getBeginLoc(), diag::err_member_function_call_bad_type)
5359 << ImplicitParamRecordType << FromRecordType
5360 << From->getSourceRange();
5361 }
5362
5363 if (ICS.Standard.Second == ICK_Derived_To_Base) {
5364 ExprResult FromRes =
5365 PerformObjectMemberConversion(From, Qualifier, FoundDecl, Method);
5366 if (FromRes.isInvalid())
5367 return ExprError();
5368 From = FromRes.get();
5369 }
5370
5371 if (!Context.hasSameType(From->getType(), DestType)) {
5372 CastKind CK;
5373 QualType PteeTy = DestType->getPointeeType();
5374 LangAS DestAS =
5375 PteeTy.isNull() ? DestType.getAddressSpace() : PteeTy.getAddressSpace();
5376 if (FromRecordType.getAddressSpace() != DestAS)
5377 CK = CK_AddressSpaceConversion;
5378 else
5379 CK = CK_NoOp;
5380 From = ImpCastExprToType(From, DestType, CK, From->getValueKind()).get();
5381 }
5382 return From;
5383}
5384
5385/// TryContextuallyConvertToBool - Attempt to contextually convert the
5386/// expression From to bool (C++0x [conv]p3).
5387static ImplicitConversionSequence
5388TryContextuallyConvertToBool(Sema &S, Expr *From) {
5389 return TryImplicitConversion(S, From, S.Context.BoolTy,
5390 /*SuppressUserConversions=*/false,
5391 /*AllowExplicit=*/true,
5392 /*InOverloadResolution=*/false,
5393 /*CStyle=*/false,
5394 /*AllowObjCWritebackConversion=*/false,
5395 /*AllowObjCConversionOnExplicit=*/false);
5396}
5397
5398/// PerformContextuallyConvertToBool - Perform a contextual conversion
5399/// of the expression From to bool (C++0x [conv]p3).
5400ExprResult Sema::PerformContextuallyConvertToBool(Expr *From) {
5401 if (checkPlaceholderForOverload(*this, From))
5402 return ExprError();
5403
5404 ImplicitConversionSequence ICS = TryContextuallyConvertToBool(*this, From);
5405 if (!ICS.isBad())
5406 return PerformImplicitConversion(From, Context.BoolTy, ICS, AA_Converting);
5407
5408 if (!DiagnoseMultipleUserDefinedConversion(From, Context.BoolTy))
5409 return Diag(From->getBeginLoc(), diag::err_typecheck_bool_condition)
5410 << From->getType() << From->getSourceRange();
5411 return ExprError();
5412}
5413
5414/// Check that the specified conversion is permitted in a converted constant
5415/// expression, according to C++11 [expr.const]p3. Return true if the conversion
5416/// is acceptable.
5417static bool CheckConvertedConstantConversions(Sema &S,
5418 StandardConversionSequence &SCS) {
5419 // Since we know that the target type is an integral or unscoped enumeration
5420 // type, most conversion kinds are impossible. All possible First and Third
5421 // conversions are fine.
5422 switch (SCS.Second) {
5423 case ICK_Identity:
5424 case ICK_Function_Conversion:
5425 case ICK_Integral_Promotion:
5426 case ICK_Integral_Conversion: // Narrowing conversions are checked elsewhere.
5427 case ICK_Zero_Queue_Conversion:
5428 return true;
5429
5430 case ICK_Boolean_Conversion:
5431 // Conversion from an integral or unscoped enumeration type to bool is
5432 // classified as ICK_Boolean_Conversion, but it's also arguably an integral
5433 // conversion, so we allow it in a converted constant expression.
5434 //
5435 // FIXME: Per core issue 1407, we should not allow this, but that breaks
5436 // a lot of popular code. We should at least add a warning for this
5437 // (non-conforming) extension.
5438 return SCS.getFromType()->isIntegralOrUnscopedEnumerationType() &&
5439 SCS.getToType(2)->isBooleanType();
5440
5441 case ICK_Pointer_Conversion:
5442 case ICK_Pointer_Member:
5443 // C++1z: null pointer conversions and null member pointer conversions are
5444 // only permitted if the source type is std::nullptr_t.
5445 return SCS.getFromType()->isNullPtrType();
5446
5447 case ICK_Floating_Promotion:
5448 case ICK_Complex_Promotion:
5449 case ICK_Floating_Conversion:
5450 case ICK_Complex_Conversion:
5451 case ICK_Floating_Integral:
5452 case ICK_Compatible_Conversion:
5453 case ICK_Derived_To_Base:
5454 case ICK_Vector_Conversion:
5455 case ICK_Vector_Splat:
5456 case ICK_Complex_Real:
5457 case ICK_Block_Pointer_Conversion:
5458 case ICK_TransparentUnionConversion:
5459 case ICK_Writeback_Conversion:
5460 case ICK_Zero_Event_Conversion:
5461 case ICK_C_Only_Conversion:
5462 case ICK_Incompatible_Pointer_Conversion:
5463 return false;
5464
5465 case ICK_Lvalue_To_Rvalue:
5466 case ICK_Array_To_Pointer:
5467 case ICK_Function_To_Pointer:
5468 llvm_unreachable("found a first conversion kind in Second")::llvm::llvm_unreachable_internal("found a first conversion kind in Second"
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaOverload.cpp"
, 5468)
;
5469
5470 case ICK_Qualification:
5471 llvm_unreachable("found a third conversion kind in Second")::llvm::llvm_unreachable_internal("found a third conversion kind in Second"
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaOverload.cpp"
, 5471)
;
5472
5473 case ICK_Num_Conversion_Kinds:
5474 break;
5475 }
5476
5477 llvm_unreachable("unknown conversion kind")::llvm::llvm_unreachable_internal("unknown conversion kind", "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaOverload.cpp"
, 5477)
;
5478}
5479
5480/// CheckConvertedConstantExpression - Check that the expression From is a
5481/// converted constant expression of type T, perform the conversion and produce
5482/// the converted expression, per C++11 [expr.const]p3.
5483static ExprResult CheckConvertedConstantExpression(Sema &S, Expr *From,
5484 QualType T, APValue &Value,
5485 Sema::CCEKind CCE,
5486 bool RequireInt) {
5487 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-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaOverload.cpp"
, 5488, __PRETTY_FUNCTION__))
5488 "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-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaOverload.cpp"
, 5488, __PRETTY_FUNCTION__))
;
5489
5490 if (checkPlaceholderForOverload(S, From))
5491 return ExprError();
5492
5493 // C++1z [expr.const]p3:
5494 // A converted constant expression of type T is an expression,
5495 // implicitly converted to type T, where the converted
5496 // expression is a constant expression and the implicit conversion
5497 // sequence contains only [... list of conversions ...].
5498 // C++1z [stmt.if]p2:
5499 // If the if statement is of the form if constexpr, the value of the
5500 // condition shall be a contextually converted constant expression of type
5501 // bool.
5502 ImplicitConversionSequence ICS =
5503 CCE == Sema::CCEK_ConstexprIf || CCE == Sema::CCEK_ExplicitBool
5504 ? TryContextuallyConvertToBool(S, From)
5505 : TryCopyInitialization(S, From, T,
5506 /*SuppressUserConversions=*/false,
5507 /*InOverloadResolution=*/false,
5508 /*AllowObjCWritebackConversion=*/false,
5509 /*AllowExplicit=*/false);
5510 StandardConversionSequence *SCS = nullptr;
5511 switch (ICS.getKind()) {
5512 case ImplicitConversionSequence::StandardConversion:
5513 SCS = &ICS.Standard;
5514 break;
5515 case ImplicitConversionSequence::UserDefinedConversion:
5516 // We are converting to a non-class type, so the Before sequence
5517 // must be trivial.
5518 SCS = &ICS.UserDefined.After;
5519 break;
5520 case ImplicitConversionSequence::AmbiguousConversion:
5521 case ImplicitConversionSequence::BadConversion:
5522 if (!S.DiagnoseMultipleUserDefinedConversion(From, T))
5523 return S.Diag(From->getBeginLoc(),
5524 diag::err_typecheck_converted_constant_expression)
5525 << From->getType() << From->getSourceRange() << T;
5526 return ExprError();
5527
5528 case ImplicitConversionSequence::EllipsisConversion:
5529 llvm_unreachable("ellipsis conversion in converted constant expression")::llvm::llvm_unreachable_internal("ellipsis conversion in converted constant expression"
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaOverload.cpp"
, 5529)
;
5530 }
5531
5532 // Check that we would only use permitted conversions.
5533 if (!CheckConvertedConstantConversions(S, *SCS)) {
5534 return S.Diag(From->getBeginLoc(),
5535 diag::err_typecheck_converted_constant_expression_disallowed)
5536 << From->getType() << From->getSourceRange() << T;
5537 }
5538 // [...] and where the reference binding (if any) binds directly.
5539 if (SCS->ReferenceBinding && !SCS->DirectBinding) {
5540 return S.Diag(From->getBeginLoc(),
5541 diag::err_typecheck_converted_constant_expression_indirect)
5542 << From->getType() << From->getSourceRange() << T;
5543 }
5544
5545 ExprResult Result =
5546 S.PerformImplicitConversion(From, T, ICS, Sema::AA_Converting);
5547 if (Result.isInvalid())
5548 return Result;
5549
5550 // C++2a [intro.execution]p5:
5551 // A full-expression is [...] a constant-expression [...]
5552 Result =
5553 S.ActOnFinishFullExpr(Result.get(), From->getExprLoc(),
5554 /*DiscardedValue=*/false, /*IsConstexpr=*/true);
5555 if (Result.isInvalid())
5556 return Result;
5557
5558 // Check for a narrowing implicit conversion.
5559 APValue PreNarrowingValue;
5560 QualType PreNarrowingType;
5561 switch (SCS->getNarrowingKind(S.Context, Result.get(), PreNarrowingValue,
5562 PreNarrowingType)) {
5563 case NK_Dependent_Narrowing:
5564 // Implicit conversion to a narrower type, but the expression is
5565 // value-dependent so we can't tell whether it's actually narrowing.
5566 case NK_Variable_Narrowing:
5567 // Implicit conversion to a narrower type, and the value is not a constant
5568 // expression. We'll diagnose this in a moment.
5569 case NK_Not_Narrowing:
5570 break;
5571
5572 case NK_Constant_Narrowing:
5573 S.Diag(From->getBeginLoc(), diag::ext_cce_narrowing)
5574 << CCE << /*Constant*/ 1
5575 << PreNarrowingValue.getAsString(S.Context, PreNarrowingType) << T;
5576 break;
5577
5578 case NK_Type_Narrowing:
5579 S.Diag(From->getBeginLoc(), diag::ext_cce_narrowing)
5580 << CCE << /*Constant*/ 0 << From->getType() << T;
5581 break;
5582 }
5583
5584 if (Result.get()->isValueDependent()) {
5585 Value = APValue();
5586 return Result;
5587 }
5588
5589 // Check the expression is a constant expression.
5590 SmallVector<PartialDiagnosticAt, 8> Notes;
5591 Expr::EvalResult Eval;
5592 Eval.Diag = &Notes;
5593 Expr::ConstExprUsage Usage = CCE == Sema::CCEK_TemplateArg
5594 ? Expr::EvaluateForMangling
5595 : Expr::EvaluateForCodeGen;
5596
5597 if (!Result.get()->EvaluateAsConstantExpr(Eval, Usage, S.Context) ||
5598 (RequireInt && !Eval.Val.isInt())) {
5599 // The expression can't be folded, so we can't keep it at this position in
5600 // the AST.
5601 Result = ExprError();
5602 } else {
5603 Value = Eval.Val;
5604
5605 if (Notes.empty()) {
5606 // It's a constant expression.
5607 return ConstantExpr::Create(S.Context, Result.get(), Value);
5608 }
5609 }
5610
5611 // It's not a constant expression. Produce an appropriate diagnostic.
5612 if (Notes.size() == 1 &&
5613 Notes[0].second.getDiagID() == diag::note_invalid_subexpr_in_const_expr)
5614 S.Diag(Notes[0].first, diag::err_expr_not_cce) << CCE;
5615 else {
5616 S.Diag(From->getBeginLoc(), diag::err_expr_not_cce)
5617 << CCE << From->getSourceRange();
5618 for (unsigned I = 0; I < Notes.size(); ++I)
5619 S.Diag(Notes[I].first, Notes[I].second);
5620 }
5621 return ExprError();
5622}
5623
5624ExprResult Sema::CheckConvertedConstantExpression(Expr *From, QualType T,
5625 APValue &Value, CCEKind CCE) {
5626 return ::CheckConvertedConstantExpression(*this, From, T, Value, CCE, false);
5627}
5628
5629ExprResult Sema::CheckConvertedConstantExpression(Expr *From, QualType T,
5630 llvm::APSInt &Value,
5631 CCEKind CCE) {
5632 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-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaOverload.cpp"
, 5632, __PRETTY_FUNCTION__))
;
5633
5634 APValue V;
5635 auto R = ::CheckConvertedConstantExpression(*this, From, T, V, CCE, true);
5636 if (!R.isInvalid() && !R.get()->isValueDependent())
5637 Value = V.getInt();
5638 return R;
5639}
5640
5641
5642/// dropPointerConversions - If the given standard conversion sequence
5643/// involves any pointer conversions, remove them. This may change
5644/// the result type of the conversion sequence.
5645static void dropPointerConversion(StandardConversionSequence &SCS) {
5646 if (SCS.Second == ICK_Pointer_Conversion) {
5647 SCS.Second = ICK_Identity;
5648 SCS.Third = ICK_Identity;
5649 SCS.ToTypePtrs[2] = SCS.ToTypePtrs[1] = SCS.ToTypePtrs[0];
5650 }
5651}
5652
5653/// TryContextuallyConvertToObjCPointer - Attempt to contextually
5654/// convert the expression From to an Objective-C pointer type.
5655static ImplicitConversionSequence
5656TryContextuallyConvertToObjCPointer(Sema &S, Expr *From) {
5657 // Do an implicit conversion to 'id'.
5658 QualType Ty = S.Context.getObjCIdType();
5659 ImplicitConversionSequence ICS
5660 = TryImplicitConversion(S, From, Ty,
5661 // FIXME: Are these flags correct?
5662 /*SuppressUserConversions=*/false,
5663 /*AllowExplicit=*/true,
5664 /*InOverloadResolution=*/false,
5665 /*CStyle=*/false,
5666 /*AllowObjCWritebackConversion=*/false,
5667 /*AllowObjCConversionOnExplicit=*/true);
5668
5669 // Strip off any final conversions to 'id'.
5670 switch (ICS.getKind()) {
5671 case ImplicitConversionSequence::BadConversion:
5672 case ImplicitConversionSequence::AmbiguousConversion:
5673 case ImplicitConversionSequence::EllipsisConversion:
5674 break;
5675
5676 case ImplicitConversionSequence::UserDefinedConversion:
5677 dropPointerConversion(ICS.UserDefined.After);
5678 break;
5679
5680 case ImplicitConversionSequence::StandardConversion:
5681 dropPointerConversion(ICS.Standard);
5682 break;
5683 }
5684
5685 return ICS;
5686}
5687
5688/// PerformContextuallyConvertToObjCPointer - Perform a contextual
5689/// conversion of the expression From to an Objective-C pointer type.
5690/// Returns a valid but null ExprResult if no conversion sequence exists.
5691ExprResult Sema::PerformContextuallyConvertToObjCPointer(Expr *From) {
5692 if (checkPlaceholderForOverload(*this, From))
5693 return ExprError();
5694
5695 QualType Ty = Context.getObjCIdType();
5696 ImplicitConversionSequence ICS =
5697 TryContextuallyConvertToObjCPointer(*this, From);
5698 if (!ICS.isBad())
5699 return PerformImplicitConversion(From, Ty, ICS, AA_Converting);
5700 return ExprResult();
5701}
5702
5703/// Determine whether the provided type is an integral type, or an enumeration
5704/// type of a permitted flavor.
5705bool Sema::ICEConvertDiagnoser::match(QualType T) {
5706 return AllowScopedEnumerations ? T->isIntegralOrEnumerationType()
5707 : T->isIntegralOrUnscopedEnumerationType();
5708}
5709
5710static ExprResult
5711diagnoseAmbiguousConversion(Sema &SemaRef, SourceLocation Loc, Expr *From,
5712 Sema::ContextualImplicitConverter &Converter,
5713 QualType T, UnresolvedSetImpl &ViableConversions) {
5714
5715 if (Converter.Suppress)
5716 return ExprError();
5717
5718 Converter.diagnoseAmbiguous(SemaRef, Loc, T) << From->getSourceRange();
5719 for (unsigned I = 0, N = ViableConversions.size(); I != N; ++I) {
5720 CXXConversionDecl *Conv =
5721 cast<CXXConversionDecl>(ViableConversions[I]->getUnderlyingDecl());
5722 QualType ConvTy = Conv->getConversionType().getNonReferenceType();
5723 Converter.noteAmbiguous(SemaRef, Conv, ConvTy);
5724 }
5725 return From;
5726}
5727
5728static bool
5729diagnoseNoViableConversion(Sema &SemaRef, SourceLocation Loc, Expr *&From,
5730 Sema::ContextualImplicitConverter &Converter,
5731 QualType T, bool HadMultipleCandidates,
5732 UnresolvedSetImpl &ExplicitConversions) {
5733 if (ExplicitConversions.size() == 1 && !Converter.Suppress) {
5734 DeclAccessPair Found = ExplicitConversions[0];
5735 CXXConversionDecl *Conversion =
5736 cast<CXXConversionDecl>(Found->getUnderlyingDecl());
5737
5738 // The user probably meant to invoke the given explicit
5739 // conversion; use it.
5740 QualType ConvTy = Conversion->getConversionType().getNonReferenceType();
5741 std::string TypeStr;
5742 ConvTy.getAsStringInternal(TypeStr, SemaRef.getPrintingPolicy());
5743
5744 Converter.diagnoseExplicitConv(SemaRef, Loc, T, ConvTy)
5745 << FixItHint::CreateInsertion(From->getBeginLoc(),
5746 "static_cast<" + TypeStr + ">(")
5747 << FixItHint::CreateInsertion(
5748 SemaRef.getLocForEndOfToken(From->getEndLoc()), ")");
5749 Converter.noteExplicitConv(SemaRef, Conversion, ConvTy);
5750
5751 // If we aren't in a SFINAE context, build a call to the
5752 // explicit conversion function.
5753 if (SemaRef.isSFINAEContext())
5754 return true;
5755
5756 SemaRef.CheckMemberOperatorAccess(From->getExprLoc(), From, nullptr, Found);
5757 ExprResult Result = SemaRef.BuildCXXMemberCallExpr(From, Found, Conversion,
5758 HadMultipleCandidates);
5759 if (Result.isInvalid())
5760 return true;
5761 // Record usage of conversion in an implicit cast.
5762 From = ImplicitCastExpr::Create(SemaRef.Context, Result.get()->getType(),
5763 CK_UserDefinedConversion, Result.get(),
5764 nullptr, Result.get()->getValueKind());
5765 }
5766 return false;
5767}
5768
5769static bool recordConversion(Sema &SemaRef, SourceLocation Loc, Expr *&From,
5770 Sema::ContextualImplicitConverter &Converter,
5771 QualType T, bool HadMultipleCandidates,
5772 DeclAccessPair &Found) {
5773 CXXConversionDecl *Conversion =
5774 cast<CXXConversionDecl>(Found->getUnderlyingDecl());
5775 SemaRef.CheckMemberOperatorAccess(From->getExprLoc(), From, nullptr, Found);
5776
5777 QualType ToType = Conversion->getConversionType().getNonReferenceType();
5778 if (!Converter.SuppressConversion) {
5779 if (SemaRef.isSFINAEContext())
5780 return true;
5781
5782 Converter.diagnoseConversion(SemaRef, Loc, T, ToType)
5783 << From->getSourceRange();
5784 }
5785
5786 ExprResult Result = SemaRef.BuildCXXMemberCallExpr(From, Found, Conversion,
5787 HadMultipleCandidates);
5788 if (Result.isInvalid())
5789 return true;
5790 // Record usage of conversion in an implicit cast.
5791 From = ImplicitCastExpr::Create(SemaRef.Context, Result.get()->getType(),
5792 CK_UserDefinedConversion, Result.get(),
5793 nullptr, Result.get()->getValueKind());
5794 return false;
5795}
5796
5797static ExprResult finishContextualImplicitConversion(
5798 Sema &SemaRef, SourceLocation Loc, Expr *From,
5799 Sema::ContextualImplicitConverter &Converter) {
5800 if (!Converter.match(From->getType()) && !Converter.Suppress)
5801 Converter.diagnoseNoMatch(SemaRef, Loc, From->getType())
5802 << From->getSourceRange();
5803
5804 return SemaRef.DefaultLvalueConversion(From);
5805}
5806
5807static void
5808collectViableConversionCandidates(Sema &SemaRef, Expr *From, QualType ToType,
5809 UnresolvedSetImpl &ViableConversions,
5810 OverloadCandidateSet &CandidateSet) {
5811 for (unsigned I = 0, N = ViableConversions.size(); I != N; ++I) {
5812 DeclAccessPair FoundDecl = ViableConversions[I];
5813 NamedDecl *D = FoundDecl.getDecl();
5814 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext());
5815 if (isa<UsingShadowDecl>(D))
5816 D = cast<UsingShadowDecl>(D)->getTargetDecl();
5817
5818 CXXConversionDecl *Conv;
5819 FunctionTemplateDecl *ConvTemplate;
5820 if ((ConvTemplate = dyn_cast<FunctionTemplateDecl>(D)))
5821 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl());
5822 else
5823 Conv = cast<CXXConversionDecl>(D);
5824
5825 if (ConvTemplate)
5826 SemaRef.AddTemplateConversionCandidate(
5827 ConvTemplate, FoundDecl, ActingContext, From, ToType, CandidateSet,
5828 /*AllowObjCConversionOnExplicit=*/false, /*AllowExplicit*/ true);
5829 else
5830 SemaRef.AddConversionCandidate(Conv, FoundDecl, ActingContext, From,
5831 ToType, CandidateSet,
5832 /*AllowObjCConversionOnExplicit=*/false,
5833 /*AllowExplicit*/ true);
5834 }
5835}
5836
5837/// Attempt to convert the given expression to a type which is accepted
5838/// by the given converter.
5839///
5840/// This routine will attempt to convert an expression of class type to a
5841/// type accepted by the specified converter. In C++11 and before, the class
5842/// must have a single non-explicit conversion function converting to a matching
5843/// type. In C++1y, there can be multiple such conversion functions, but only
5844/// one target type.
5845///
5846/// \param Loc The source location of the construct that requires the
5847/// conversion.
5848///
5849/// \param From The expression we're converting from.
5850///
5851/// \param Converter Used to control and diagnose the conversion process.
5852///
5853/// \returns The expression, converted to an integral or enumeration type if
5854/// successful.
5855ExprResult Sema::PerformContextualImplicitConversion(
5856 SourceLocation Loc, Expr *From, ContextualImplicitConverter &Converter) {
5857 // We can't perform any more checking for type-dependent expressions.
5858 if (From->isTypeDependent())
5859 return From;
5860
5861 // Process placeholders immediately.
5862 if (From->hasPlaceholderType()) {
5863 ExprResult result = CheckPlaceholderExpr(From);
5864 if (result.isInvalid())
5865 return result;
5866 From = result.get();
5867 }
5868
5869 // If the expression already has a matching type, we're golden.
5870 QualType T = From->getType();
5871 if (Converter.match(T))
5872 return DefaultLvalueConversion(From);
5873
5874 // FIXME: Check for missing '()' if T is a function type?
5875
5876 // We can only perform contextual implicit conversions on objects of class
5877 // type.
5878 const RecordType *RecordTy = T->getAs<RecordType>();
5879 if (!RecordTy || !getLangOpts().CPlusPlus) {
5880 if (!Converter.Suppress)
5881 Converter.diagnoseNoMatch(*this, Loc, T) << From->getSourceRange();
5882 return From;
5883 }
5884
5885 // We must have a complete class type.
5886 struct TypeDiagnoserPartialDiag : TypeDiagnoser {
5887 ContextualImplicitConverter &Converter;
5888 Expr *From;
5889
5890 TypeDiagnoserPartialDiag(ContextualImplicitConverter &Converter, Expr *From)
5891 : Converter(Converter), From(From) {}
5892
5893 void diagnose(Sema &S, SourceLocation Loc, QualType T) override {
5894 Converter.diagnoseIncomplete(S, Loc, T) << From->getSourceRange();
5895 }
5896 } IncompleteDiagnoser(Converter, From);
5897
5898 if (Converter.Suppress ? !isCompleteType(Loc, T)
5899 : RequireCompleteType(Loc, T, IncompleteDiagnoser))
5900 return From;
5901
5902 // Look for a conversion to an integral or enumeration type.
5903 UnresolvedSet<4>
5904 ViableConversions; // These are *potentially* viable in C++1y.
5905 UnresolvedSet<4> ExplicitConversions;
5906 const auto &Conversions =
5907 cast<CXXRecordDecl>(RecordTy->getDecl())->getVisibleConversionFunct