Bug Summary

File:clang/lib/Sema/SemaOverload.cpp
Warning:line 3247, column 7
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
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()) {
2799 PDiag << ft_default;
2800 return;
2801 }
2802
2803 // Get the function type from the pointers.
2804 if (FromType->isMemberPointerType() && ToType->isMemberPointerType()) {
2805 const MemberPointerType *FromMember = FromType->getAs<MemberPointerType>(),
2806 *ToMember = ToType->getAs<MemberPointerType>();
2807 if (!Context.hasSameType(FromMember->getClass(), ToMember->getClass())) {
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 =
24
'CtorType' initialized to a null pointer value
3246 Constructor->getType()->getAs<FunctionProtoType>();
23
Assuming the object is not a 'FunctionProtoType'
3247 if (CtorType->getNumParams() > 0) {
25
Called C++ object pointer is null
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)
18
Taking false branch
3265 continue;
3266
3267 bool Usable = !Info.Constructor->isInvalidDecl() &&
19
Assuming the condition is true
3268 S.isInitListConstructor(Info.Constructor) &&
20
Assuming the condition is true
3269 (AllowExplicit
20.1
'AllowExplicit' is false
|| !Info.Constructor->isExplicit());
3270 if (Usable
20.2
'Usable' is true
) {
21
Taking true branch
3271 // If the first argument is (a reference to) the target type,
3272 // suppress conversions.
3273 bool SuppressUserConversions = isFirstArgumentCompatibleWithType(
22
Calling '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
4.1
'AllowExplicit' is false
4.2
'AllowObjCConversionOnExplicit' is false
(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__))
;
5
'?' condition is true
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>()) {
6
Assuming the object is a 'RecordType'
7
Assuming 'ToRecordType' is non-null
8
Taking true branch
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()) ||
9
Assuming the condition is false
11
Taking false branch
3356 (From->getType()->getAs<RecordType>() &&
10
Assuming the object is not a 'RecordType'
3357 S.IsDerivedFrom(From->getBeginLoc(), From->getType(), ToType))) 3358 ConstructorsOnly = true; 3359 3360 if (!S.isCompleteType(From->getExprLoc(), ToType)) {
12
Taking false branch
3361 // We're not going to find any constructors. 3362 } else if (CXXRecordDecl *ToRecordDecl
13.1
'ToRecordDecl' is non-null
14
Taking true branch
3363 = dyn_cast<CXXRecordDecl>(ToRecordType->getDecl())) {
13
Assuming the object is a 'CXXRecordDecl'
3364 3365 Expr **Args = &From; 3366 unsigned NumArgs = 1; 3367 bool ListInitializing = false; 3368 if (InitListExpr *InitList
15.1
'InitList' is non-null
= dyn_cast<InitListExpr>(From)) {
15
Assuming 'From' is a 'InitListExpr'
16
Taking true branch
3369 // But first, see if there is an init-list-constructor that will work. 3370 OverloadingResult Result = IsInitializerListConstructorConversion(
17
Calling '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,
4
Calling 'IsUserDefinedConversion'
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))
1
Taking false branch
5402 return ExprError(); 5403 5404 ImplicitConversionSequence ICS = TryContextuallyConvertToBool(*this, From); 5405 if (!ICS.isBad())
2
Taking false branch
5406 return PerformImplicitConversion(From, Context.BoolTy, ICS, AA_Converting); 5407 5408 if (!DiagnoseMultipleUserDefinedConversion(From, Context.BoolTy))
3
Calling 'Sema::DiagnoseMultipleUserDefinedConversion'
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