Bug Summary

File:clang/lib/Sema/SemaTemplateDeduction.cpp
Warning:line 2171, column 31
Called C++ object pointer is null

Annotated Source Code

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clang -cc1 -cc1 -triple x86_64-pc-linux-gnu -analyze -disable-free -clear-ast-before-backend -disable-llvm-verifier -discard-value-names -main-file-name SemaTemplateDeduction.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 -mframe-pointer=none -relaxed-aliasing -fmath-errno -fno-rounding-math -mconstructor-aliases -funwind-tables=2 -target-cpu x86-64 -tune-cpu generic -debugger-tuning=gdb -ffunction-sections -fdata-sections -fcoverage-compilation-dir=/build/llvm-toolchain-snapshot-14~++20211110111138+cffbfd01e37b/build-llvm -resource-dir /usr/lib/llvm-14/lib/clang/14.0.0 -D CLANG_ROUND_TRIP_CC1_ARGS=ON -D _DEBUG -D _GNU_SOURCE -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D __STDC_LIMIT_MACROS -I tools/clang/lib/Sema -I /build/llvm-toolchain-snapshot-14~++20211110111138+cffbfd01e37b/clang/lib/Sema -I /build/llvm-toolchain-snapshot-14~++20211110111138+cffbfd01e37b/clang/include -I tools/clang/include -I include -I /build/llvm-toolchain-snapshot-14~++20211110111138+cffbfd01e37b/llvm/include -D NDEBUG -U NDEBUG -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../include/c++/10 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../include/x86_64-linux-gnu/c++/10 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../include/c++/10/backward -internal-isystem /usr/lib/llvm-14/lib/clang/14.0.0/include -internal-isystem /usr/local/include -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../x86_64-linux-gnu/include -internal-externc-isystem /usr/include/x86_64-linux-gnu -internal-externc-isystem /include -internal-externc-isystem /usr/include -O2 -Wno-unused-command-line-argument -Wno-unknown-warning-option -Wno-unused-parameter -Wwrite-strings -Wno-missing-field-initializers -Wno-long-long -Wno-maybe-uninitialized -Wno-class-memaccess -Wno-redundant-move -Wno-pessimizing-move -Wno-noexcept-type -Wno-comment -std=c++14 -fdeprecated-macro -fdebug-compilation-dir=/build/llvm-toolchain-snapshot-14~++20211110111138+cffbfd01e37b/build-llvm -ferror-limit 19 -fvisibility-inlines-hidden -fgnuc-version=4.2.1 -fcolor-diagnostics -vectorize-loops -vectorize-slp -analyzer-output=html -analyzer-config stable-report-filename=true -faddrsig -D__GCC_HAVE_DWARF2_CFI_ASM=1 -o /tmp/scan-build-2021-11-10-160236-22541-1 -x c++ /build/llvm-toolchain-snapshot-14~++20211110111138+cffbfd01e37b/clang/lib/Sema/SemaTemplateDeduction.cpp
1//===- SemaTemplateDeduction.cpp - Template Argument Deduction ------------===//
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 implements C++ template argument deduction.
10//
11//===----------------------------------------------------------------------===//
12
13#include "clang/Sema/TemplateDeduction.h"
14#include "TreeTransform.h"
15#include "TypeLocBuilder.h"
16#include "clang/AST/ASTContext.h"
17#include "clang/AST/ASTLambda.h"
18#include "clang/AST/Decl.h"
19#include "clang/AST/DeclAccessPair.h"
20#include "clang/AST/DeclBase.h"
21#include "clang/AST/DeclCXX.h"
22#include "clang/AST/DeclTemplate.h"
23#include "clang/AST/DeclarationName.h"
24#include "clang/AST/Expr.h"
25#include "clang/AST/ExprCXX.h"
26#include "clang/AST/NestedNameSpecifier.h"
27#include "clang/AST/RecursiveASTVisitor.h"
28#include "clang/AST/TemplateBase.h"
29#include "clang/AST/TemplateName.h"
30#include "clang/AST/Type.h"
31#include "clang/AST/TypeLoc.h"
32#include "clang/AST/UnresolvedSet.h"
33#include "clang/Basic/AddressSpaces.h"
34#include "clang/Basic/ExceptionSpecificationType.h"
35#include "clang/Basic/LLVM.h"
36#include "clang/Basic/LangOptions.h"
37#include "clang/Basic/PartialDiagnostic.h"
38#include "clang/Basic/SourceLocation.h"
39#include "clang/Basic/Specifiers.h"
40#include "clang/Sema/Ownership.h"
41#include "clang/Sema/Sema.h"
42#include "clang/Sema/Template.h"
43#include "llvm/ADT/APInt.h"
44#include "llvm/ADT/APSInt.h"
45#include "llvm/ADT/ArrayRef.h"
46#include "llvm/ADT/DenseMap.h"
47#include "llvm/ADT/FoldingSet.h"
48#include "llvm/ADT/Optional.h"
49#include "llvm/ADT/SmallBitVector.h"
50#include "llvm/ADT/SmallPtrSet.h"
51#include "llvm/ADT/SmallVector.h"
52#include "llvm/Support/Casting.h"
53#include "llvm/Support/Compiler.h"
54#include "llvm/Support/ErrorHandling.h"
55#include <algorithm>
56#include <cassert>
57#include <tuple>
58#include <utility>
59
60namespace clang {
61
62 /// Various flags that control template argument deduction.
63 ///
64 /// These flags can be bitwise-OR'd together.
65 enum TemplateDeductionFlags {
66 /// No template argument deduction flags, which indicates the
67 /// strictest results for template argument deduction (as used for, e.g.,
68 /// matching class template partial specializations).
69 TDF_None = 0,
70
71 /// Within template argument deduction from a function call, we are
72 /// matching with a parameter type for which the original parameter was
73 /// a reference.
74 TDF_ParamWithReferenceType = 0x1,
75
76 /// Within template argument deduction from a function call, we
77 /// are matching in a case where we ignore cv-qualifiers.
78 TDF_IgnoreQualifiers = 0x02,
79
80 /// Within template argument deduction from a function call,
81 /// we are matching in a case where we can perform template argument
82 /// deduction from a template-id of a derived class of the argument type.
83 TDF_DerivedClass = 0x04,
84
85 /// Allow non-dependent types to differ, e.g., when performing
86 /// template argument deduction from a function call where conversions
87 /// may apply.
88 TDF_SkipNonDependent = 0x08,
89
90 /// Whether we are performing template argument deduction for
91 /// parameters and arguments in a top-level template argument
92 TDF_TopLevelParameterTypeList = 0x10,
93
94 /// Within template argument deduction from overload resolution per
95 /// C++ [over.over] allow matching function types that are compatible in
96 /// terms of noreturn and default calling convention adjustments, or
97 /// similarly matching a declared template specialization against a
98 /// possible template, per C++ [temp.deduct.decl]. In either case, permit
99 /// deduction where the parameter is a function type that can be converted
100 /// to the argument type.
101 TDF_AllowCompatibleFunctionType = 0x20,
102
103 /// Within template argument deduction for a conversion function, we are
104 /// matching with an argument type for which the original argument was
105 /// a reference.
106 TDF_ArgWithReferenceType = 0x40,
107 };
108}
109
110using namespace clang;
111using namespace sema;
112
113/// Compare two APSInts, extending and switching the sign as
114/// necessary to compare their values regardless of underlying type.
115static bool hasSameExtendedValue(llvm::APSInt X, llvm::APSInt Y) {
116 if (Y.getBitWidth() > X.getBitWidth())
117 X = X.extend(Y.getBitWidth());
118 else if (Y.getBitWidth() < X.getBitWidth())
119 Y = Y.extend(X.getBitWidth());
120
121 // If there is a signedness mismatch, correct it.
122 if (X.isSigned() != Y.isSigned()) {
123 // If the signed value is negative, then the values cannot be the same.
124 if ((Y.isSigned() && Y.isNegative()) || (X.isSigned() && X.isNegative()))
125 return false;
126
127 Y.setIsSigned(true);
128 X.setIsSigned(true);
129 }
130
131 return X == Y;
132}
133
134static Sema::TemplateDeductionResult
135DeduceTemplateArguments(Sema &S,
136 TemplateParameterList *TemplateParams,
137 const TemplateArgument &Param,
138 TemplateArgument Arg,
139 TemplateDeductionInfo &Info,
140 SmallVectorImpl<DeducedTemplateArgument> &Deduced);
141
142static Sema::TemplateDeductionResult
143DeduceTemplateArgumentsByTypeMatch(Sema &S,
144 TemplateParameterList *TemplateParams,
145 QualType Param,
146 QualType Arg,
147 TemplateDeductionInfo &Info,
148 SmallVectorImpl<DeducedTemplateArgument> &
149 Deduced,
150 unsigned TDF,
151 bool PartialOrdering = false,
152 bool DeducedFromArrayBound = false);
153
154static Sema::TemplateDeductionResult
155DeduceTemplateArguments(Sema &S, TemplateParameterList *TemplateParams,
156 ArrayRef<TemplateArgument> Params,
157 ArrayRef<TemplateArgument> Args,
158 TemplateDeductionInfo &Info,
159 SmallVectorImpl<DeducedTemplateArgument> &Deduced,
160 bool NumberOfArgumentsMustMatch);
161
162static void MarkUsedTemplateParameters(ASTContext &Ctx,
163 const TemplateArgument &TemplateArg,
164 bool OnlyDeduced, unsigned Depth,
165 llvm::SmallBitVector &Used);
166
167static void MarkUsedTemplateParameters(ASTContext &Ctx, QualType T,
168 bool OnlyDeduced, unsigned Level,
169 llvm::SmallBitVector &Deduced);
170
171/// If the given expression is of a form that permits the deduction
172/// of a non-type template parameter, return the declaration of that
173/// non-type template parameter.
174static const NonTypeTemplateParmDecl *
175getDeducedParameterFromExpr(const Expr *E, unsigned Depth) {
176 // If we are within an alias template, the expression may have undergone
177 // any number of parameter substitutions already.
178 while (true) {
179 if (const auto *IC = dyn_cast<ImplicitCastExpr>(E))
180 E = IC->getSubExpr();
181 else if (const auto *CE = dyn_cast<ConstantExpr>(E))
182 E = CE->getSubExpr();
183 else if (const auto *Subst = dyn_cast<SubstNonTypeTemplateParmExpr>(E))
184 E = Subst->getReplacement();
185 else if (const auto *CCE = dyn_cast<CXXConstructExpr>(E)) {
186 // Look through implicit copy construction from an lvalue of the same type.
187 if (CCE->getParenOrBraceRange().isValid())
188 break;
189 // Note, there could be default arguments.
190 assert(CCE->getNumArgs() >= 1 && "implicit construct expr should have 1 arg")(static_cast <bool> (CCE->getNumArgs() >= 1 &&
"implicit construct expr should have 1 arg") ? void (0) : __assert_fail
("CCE->getNumArgs() >= 1 && \"implicit construct expr should have 1 arg\""
, "/build/llvm-toolchain-snapshot-14~++20211110111138+cffbfd01e37b/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 190, __extension__ __PRETTY_FUNCTION__))
;
191 E = CCE->getArg(0);
192 } else
193 break;
194 }
195
196 if (const auto *DRE = dyn_cast<DeclRefExpr>(E))
197 if (const auto *NTTP = dyn_cast<NonTypeTemplateParmDecl>(DRE->getDecl()))
198 if (NTTP->getDepth() == Depth)
199 return NTTP;
200
201 return nullptr;
202}
203
204static const NonTypeTemplateParmDecl *
205getDeducedParameterFromExpr(TemplateDeductionInfo &Info, Expr *E) {
206 return getDeducedParameterFromExpr(E, Info.getDeducedDepth());
207}
208
209/// Determine whether two declaration pointers refer to the same
210/// declaration.
211static bool isSameDeclaration(Decl *X, Decl *Y) {
212 if (NamedDecl *NX = dyn_cast<NamedDecl>(X))
213 X = NX->getUnderlyingDecl();
214 if (NamedDecl *NY = dyn_cast<NamedDecl>(Y))
215 Y = NY->getUnderlyingDecl();
216
217 return X->getCanonicalDecl() == Y->getCanonicalDecl();
218}
219
220/// Verify that the given, deduced template arguments are compatible.
221///
222/// \returns The deduced template argument, or a NULL template argument if
223/// the deduced template arguments were incompatible.
224static DeducedTemplateArgument
225checkDeducedTemplateArguments(ASTContext &Context,
226 const DeducedTemplateArgument &X,
227 const DeducedTemplateArgument &Y) {
228 // We have no deduction for one or both of the arguments; they're compatible.
229 if (X.isNull())
230 return Y;
231 if (Y.isNull())
232 return X;
233
234 // If we have two non-type template argument values deduced for the same
235 // parameter, they must both match the type of the parameter, and thus must
236 // match each other's type. As we're only keeping one of them, we must check
237 // for that now. The exception is that if either was deduced from an array
238 // bound, the type is permitted to differ.
239 if (!X.wasDeducedFromArrayBound() && !Y.wasDeducedFromArrayBound()) {
240 QualType XType = X.getNonTypeTemplateArgumentType();
241 if (!XType.isNull()) {
242 QualType YType = Y.getNonTypeTemplateArgumentType();
243 if (YType.isNull() || !Context.hasSameType(XType, YType))
244 return DeducedTemplateArgument();
245 }
246 }
247
248 switch (X.getKind()) {
249 case TemplateArgument::Null:
250 llvm_unreachable("Non-deduced template arguments handled above")::llvm::llvm_unreachable_internal("Non-deduced template arguments handled above"
, "/build/llvm-toolchain-snapshot-14~++20211110111138+cffbfd01e37b/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 250)
;
251
252 case TemplateArgument::Type:
253 // If two template type arguments have the same type, they're compatible.
254 if (Y.getKind() == TemplateArgument::Type &&
255 Context.hasSameType(X.getAsType(), Y.getAsType()))
256 return X;
257
258 // If one of the two arguments was deduced from an array bound, the other
259 // supersedes it.
260 if (X.wasDeducedFromArrayBound() != Y.wasDeducedFromArrayBound())
261 return X.wasDeducedFromArrayBound() ? Y : X;
262
263 // The arguments are not compatible.
264 return DeducedTemplateArgument();
265
266 case TemplateArgument::Integral:
267 // If we deduced a constant in one case and either a dependent expression or
268 // declaration in another case, keep the integral constant.
269 // If both are integral constants with the same value, keep that value.
270 if (Y.getKind() == TemplateArgument::Expression ||
271 Y.getKind() == TemplateArgument::Declaration ||
272 (Y.getKind() == TemplateArgument::Integral &&
273 hasSameExtendedValue(X.getAsIntegral(), Y.getAsIntegral())))
274 return X.wasDeducedFromArrayBound() ? Y : X;
275
276 // All other combinations are incompatible.
277 return DeducedTemplateArgument();
278
279 case TemplateArgument::Template:
280 if (Y.getKind() == TemplateArgument::Template &&
281 Context.hasSameTemplateName(X.getAsTemplate(), Y.getAsTemplate()))
282 return X;
283
284 // All other combinations are incompatible.
285 return DeducedTemplateArgument();
286
287 case TemplateArgument::TemplateExpansion:
288 if (Y.getKind() == TemplateArgument::TemplateExpansion &&
289 Context.hasSameTemplateName(X.getAsTemplateOrTemplatePattern(),
290 Y.getAsTemplateOrTemplatePattern()))
291 return X;
292
293 // All other combinations are incompatible.
294 return DeducedTemplateArgument();
295
296 case TemplateArgument::Expression: {
297 if (Y.getKind() != TemplateArgument::Expression)
298 return checkDeducedTemplateArguments(Context, Y, X);
299
300 // Compare the expressions for equality
301 llvm::FoldingSetNodeID ID1, ID2;
302 X.getAsExpr()->Profile(ID1, Context, true);
303 Y.getAsExpr()->Profile(ID2, Context, true);
304 if (ID1 == ID2)
305 return X.wasDeducedFromArrayBound() ? Y : X;
306
307 // Differing dependent expressions are incompatible.
308 return DeducedTemplateArgument();
309 }
310
311 case TemplateArgument::Declaration:
312 assert(!X.wasDeducedFromArrayBound())(static_cast <bool> (!X.wasDeducedFromArrayBound()) ? void
(0) : __assert_fail ("!X.wasDeducedFromArrayBound()", "/build/llvm-toolchain-snapshot-14~++20211110111138+cffbfd01e37b/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 312, __extension__ __PRETTY_FUNCTION__))
;
313
314 // If we deduced a declaration and a dependent expression, keep the
315 // declaration.
316 if (Y.getKind() == TemplateArgument::Expression)
317 return X;
318
319 // If we deduced a declaration and an integral constant, keep the
320 // integral constant and whichever type did not come from an array
321 // bound.
322 if (Y.getKind() == TemplateArgument::Integral) {
323 if (Y.wasDeducedFromArrayBound())
324 return TemplateArgument(Context, Y.getAsIntegral(),
325 X.getParamTypeForDecl());
326 return Y;
327 }
328
329 // If we deduced two declarations, make sure that they refer to the
330 // same declaration.
331 if (Y.getKind() == TemplateArgument::Declaration &&
332 isSameDeclaration(X.getAsDecl(), Y.getAsDecl()))
333 return X;
334
335 // All other combinations are incompatible.
336 return DeducedTemplateArgument();
337
338 case TemplateArgument::NullPtr:
339 // If we deduced a null pointer and a dependent expression, keep the
340 // null pointer.
341 if (Y.getKind() == TemplateArgument::Expression)
342 return X;
343
344 // If we deduced a null pointer and an integral constant, keep the
345 // integral constant.
346 if (Y.getKind() == TemplateArgument::Integral)
347 return Y;
348
349 // If we deduced two null pointers, they are the same.
350 if (Y.getKind() == TemplateArgument::NullPtr)
351 return X;
352
353 // All other combinations are incompatible.
354 return DeducedTemplateArgument();
355
356 case TemplateArgument::Pack: {
357 if (Y.getKind() != TemplateArgument::Pack ||
358 X.pack_size() != Y.pack_size())
359 return DeducedTemplateArgument();
360
361 llvm::SmallVector<TemplateArgument, 8> NewPack;
362 for (TemplateArgument::pack_iterator XA = X.pack_begin(),
363 XAEnd = X.pack_end(),
364 YA = Y.pack_begin();
365 XA != XAEnd; ++XA, ++YA) {
366 TemplateArgument Merged = checkDeducedTemplateArguments(
367 Context, DeducedTemplateArgument(*XA, X.wasDeducedFromArrayBound()),
368 DeducedTemplateArgument(*YA, Y.wasDeducedFromArrayBound()));
369 if (Merged.isNull() && !(XA->isNull() && YA->isNull()))
370 return DeducedTemplateArgument();
371 NewPack.push_back(Merged);
372 }
373
374 return DeducedTemplateArgument(
375 TemplateArgument::CreatePackCopy(Context, NewPack),
376 X.wasDeducedFromArrayBound() && Y.wasDeducedFromArrayBound());
377 }
378 }
379
380 llvm_unreachable("Invalid TemplateArgument Kind!")::llvm::llvm_unreachable_internal("Invalid TemplateArgument Kind!"
, "/build/llvm-toolchain-snapshot-14~++20211110111138+cffbfd01e37b/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 380)
;
381}
382
383/// Deduce the value of the given non-type template parameter
384/// as the given deduced template argument. All non-type template parameter
385/// deduction is funneled through here.
386static Sema::TemplateDeductionResult DeduceNonTypeTemplateArgument(
387 Sema &S, TemplateParameterList *TemplateParams,
388 const NonTypeTemplateParmDecl *NTTP, const DeducedTemplateArgument &NewDeduced,
389 QualType ValueType, TemplateDeductionInfo &Info,
390 SmallVectorImpl<DeducedTemplateArgument> &Deduced) {
391 assert(NTTP->getDepth() == Info.getDeducedDepth() &&(static_cast <bool> (NTTP->getDepth() == Info.getDeducedDepth
() && "deducing non-type template argument with wrong depth"
) ? void (0) : __assert_fail ("NTTP->getDepth() == Info.getDeducedDepth() && \"deducing non-type template argument with wrong depth\""
, "/build/llvm-toolchain-snapshot-14~++20211110111138+cffbfd01e37b/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 392, __extension__ __PRETTY_FUNCTION__))
392 "deducing non-type template argument with wrong depth")(static_cast <bool> (NTTP->getDepth() == Info.getDeducedDepth
() && "deducing non-type template argument with wrong depth"
) ? void (0) : __assert_fail ("NTTP->getDepth() == Info.getDeducedDepth() && \"deducing non-type template argument with wrong depth\""
, "/build/llvm-toolchain-snapshot-14~++20211110111138+cffbfd01e37b/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 392, __extension__ __PRETTY_FUNCTION__))
;
393
394 DeducedTemplateArgument Result = checkDeducedTemplateArguments(
395 S.Context, Deduced[NTTP->getIndex()], NewDeduced);
396 if (Result.isNull()) {
397 Info.Param = const_cast<NonTypeTemplateParmDecl*>(NTTP);
398 Info.FirstArg = Deduced[NTTP->getIndex()];
399 Info.SecondArg = NewDeduced;
400 return Sema::TDK_Inconsistent;
401 }
402
403 Deduced[NTTP->getIndex()] = Result;
404 if (!S.getLangOpts().CPlusPlus17)
405 return Sema::TDK_Success;
406
407 if (NTTP->isExpandedParameterPack())
408 // FIXME: We may still need to deduce parts of the type here! But we
409 // don't have any way to find which slice of the type to use, and the
410 // type stored on the NTTP itself is nonsense. Perhaps the type of an
411 // expanded NTTP should be a pack expansion type?
412 return Sema::TDK_Success;
413
414 // Get the type of the parameter for deduction. If it's a (dependent) array
415 // or function type, we will not have decayed it yet, so do that now.
416 QualType ParamType = S.Context.getAdjustedParameterType(NTTP->getType());
417 if (auto *Expansion = dyn_cast<PackExpansionType>(ParamType))
418 ParamType = Expansion->getPattern();
419
420 // FIXME: It's not clear how deduction of a parameter of reference
421 // type from an argument (of non-reference type) should be performed.
422 // For now, we just remove reference types from both sides and let
423 // the final check for matching types sort out the mess.
424 ValueType = ValueType.getNonReferenceType();
425 if (ParamType->isReferenceType())
426 ParamType = ParamType.getNonReferenceType();
427 else
428 // Top-level cv-qualifiers are irrelevant for a non-reference type.
429 ValueType = ValueType.getUnqualifiedType();
430
431 return DeduceTemplateArgumentsByTypeMatch(
432 S, TemplateParams, ParamType, ValueType, Info, Deduced,
433 TDF_SkipNonDependent, /*PartialOrdering=*/false,
434 /*ArrayBound=*/NewDeduced.wasDeducedFromArrayBound());
435}
436
437/// Deduce the value of the given non-type template parameter
438/// from the given integral constant.
439static Sema::TemplateDeductionResult DeduceNonTypeTemplateArgument(
440 Sema &S, TemplateParameterList *TemplateParams,
441 const NonTypeTemplateParmDecl *NTTP, const llvm::APSInt &Value,
442 QualType ValueType, bool DeducedFromArrayBound, TemplateDeductionInfo &Info,
443 SmallVectorImpl<DeducedTemplateArgument> &Deduced) {
444 return DeduceNonTypeTemplateArgument(
445 S, TemplateParams, NTTP,
446 DeducedTemplateArgument(S.Context, Value, ValueType,
447 DeducedFromArrayBound),
448 ValueType, Info, Deduced);
449}
450
451/// Deduce the value of the given non-type template parameter
452/// from the given null pointer template argument type.
453static Sema::TemplateDeductionResult DeduceNullPtrTemplateArgument(
454 Sema &S, TemplateParameterList *TemplateParams,
455 const NonTypeTemplateParmDecl *NTTP, QualType NullPtrType,
456 TemplateDeductionInfo &Info,
457 SmallVectorImpl<DeducedTemplateArgument> &Deduced) {
458 Expr *Value = S.ImpCastExprToType(
459 new (S.Context) CXXNullPtrLiteralExpr(S.Context.NullPtrTy,
460 NTTP->getLocation()),
461 NullPtrType,
462 NullPtrType->isMemberPointerType() ? CK_NullToMemberPointer
463 : CK_NullToPointer)
464 .get();
465 return DeduceNonTypeTemplateArgument(S, TemplateParams, NTTP,
466 DeducedTemplateArgument(Value),
467 Value->getType(), Info, Deduced);
468}
469
470/// Deduce the value of the given non-type template parameter
471/// from the given type- or value-dependent expression.
472///
473/// \returns true if deduction succeeded, false otherwise.
474static Sema::TemplateDeductionResult DeduceNonTypeTemplateArgument(
475 Sema &S, TemplateParameterList *TemplateParams,
476 const NonTypeTemplateParmDecl *NTTP, Expr *Value, TemplateDeductionInfo &Info,
477 SmallVectorImpl<DeducedTemplateArgument> &Deduced) {
478 return DeduceNonTypeTemplateArgument(S, TemplateParams, NTTP,
479 DeducedTemplateArgument(Value),
480 Value->getType(), Info, Deduced);
481}
482
483/// Deduce the value of the given non-type template parameter
484/// from the given declaration.
485///
486/// \returns true if deduction succeeded, false otherwise.
487static Sema::TemplateDeductionResult DeduceNonTypeTemplateArgument(
488 Sema &S, TemplateParameterList *TemplateParams,
489 const NonTypeTemplateParmDecl *NTTP, ValueDecl *D, QualType T,
490 TemplateDeductionInfo &Info,
491 SmallVectorImpl<DeducedTemplateArgument> &Deduced) {
492 D = D ? cast<ValueDecl>(D->getCanonicalDecl()) : nullptr;
493 TemplateArgument New(D, T);
494 return DeduceNonTypeTemplateArgument(
495 S, TemplateParams, NTTP, DeducedTemplateArgument(New), T, Info, Deduced);
496}
497
498static Sema::TemplateDeductionResult
499DeduceTemplateArguments(Sema &S,
500 TemplateParameterList *TemplateParams,
501 TemplateName Param,
502 TemplateName Arg,
503 TemplateDeductionInfo &Info,
504 SmallVectorImpl<DeducedTemplateArgument> &Deduced) {
505 TemplateDecl *ParamDecl = Param.getAsTemplateDecl();
506 if (!ParamDecl) {
507 // The parameter type is dependent and is not a template template parameter,
508 // so there is nothing that we can deduce.
509 return Sema::TDK_Success;
510 }
511
512 if (TemplateTemplateParmDecl *TempParam
513 = dyn_cast<TemplateTemplateParmDecl>(ParamDecl)) {
514 // If we're not deducing at this depth, there's nothing to deduce.
515 if (TempParam->getDepth() != Info.getDeducedDepth())
516 return Sema::TDK_Success;
517
518 DeducedTemplateArgument NewDeduced(S.Context.getCanonicalTemplateName(Arg));
519 DeducedTemplateArgument Result = checkDeducedTemplateArguments(S.Context,
520 Deduced[TempParam->getIndex()],
521 NewDeduced);
522 if (Result.isNull()) {
523 Info.Param = TempParam;
524 Info.FirstArg = Deduced[TempParam->getIndex()];
525 Info.SecondArg = NewDeduced;
526 return Sema::TDK_Inconsistent;
527 }
528
529 Deduced[TempParam->getIndex()] = Result;
530 return Sema::TDK_Success;
531 }
532
533 // Verify that the two template names are equivalent.
534 if (S.Context.hasSameTemplateName(Param, Arg))
535 return Sema::TDK_Success;
536
537 // Mismatch of non-dependent template parameter to argument.
538 Info.FirstArg = TemplateArgument(Param);
539 Info.SecondArg = TemplateArgument(Arg);
540 return Sema::TDK_NonDeducedMismatch;
541}
542
543/// Deduce the template arguments by comparing the template parameter
544/// type (which is a template-id) with the template argument type.
545///
546/// \param S the Sema
547///
548/// \param TemplateParams the template parameters that we are deducing
549///
550/// \param Param the parameter type
551///
552/// \param Arg the argument type
553///
554/// \param Info information about the template argument deduction itself
555///
556/// \param Deduced the deduced template arguments
557///
558/// \returns the result of template argument deduction so far. Note that a
559/// "success" result means that template argument deduction has not yet failed,
560/// but it may still fail, later, for other reasons.
561static Sema::TemplateDeductionResult
562DeduceTemplateArguments(Sema &S,
563 TemplateParameterList *TemplateParams,
564 const TemplateSpecializationType *Param,
565 QualType Arg,
566 TemplateDeductionInfo &Info,
567 SmallVectorImpl<DeducedTemplateArgument> &Deduced) {
568 assert(Arg.isCanonical() && "Argument type must be canonical")(static_cast <bool> (Arg.isCanonical() && "Argument type must be canonical"
) ? void (0) : __assert_fail ("Arg.isCanonical() && \"Argument type must be canonical\""
, "/build/llvm-toolchain-snapshot-14~++20211110111138+cffbfd01e37b/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 568, __extension__ __PRETTY_FUNCTION__))
;
569
570 // Treat an injected-class-name as its underlying template-id.
571 if (auto *Injected = dyn_cast<InjectedClassNameType>(Arg))
572 Arg = Injected->getInjectedSpecializationType();
573
574 // Check whether the template argument is a dependent template-id.
575 if (const TemplateSpecializationType *SpecArg
576 = dyn_cast<TemplateSpecializationType>(Arg)) {
577 // Perform template argument deduction for the template name.
578 if (Sema::TemplateDeductionResult Result
579 = DeduceTemplateArguments(S, TemplateParams,
580 Param->getTemplateName(),
581 SpecArg->getTemplateName(),
582 Info, Deduced))
583 return Result;
584
585
586 // Perform template argument deduction on each template
587 // argument. Ignore any missing/extra arguments, since they could be
588 // filled in by default arguments.
589 return DeduceTemplateArguments(S, TemplateParams,
590 Param->template_arguments(),
591 SpecArg->template_arguments(), Info, Deduced,
592 /*NumberOfArgumentsMustMatch=*/false);
593 }
594
595 // If the argument type is a class template specialization, we
596 // perform template argument deduction using its template
597 // arguments.
598 const RecordType *RecordArg = dyn_cast<RecordType>(Arg);
599 if (!RecordArg) {
600 Info.FirstArg = TemplateArgument(QualType(Param, 0));
601 Info.SecondArg = TemplateArgument(Arg);
602 return Sema::TDK_NonDeducedMismatch;
603 }
604
605 ClassTemplateSpecializationDecl *SpecArg
606 = dyn_cast<ClassTemplateSpecializationDecl>(RecordArg->getDecl());
607 if (!SpecArg) {
608 Info.FirstArg = TemplateArgument(QualType(Param, 0));
609 Info.SecondArg = TemplateArgument(Arg);
610 return Sema::TDK_NonDeducedMismatch;
611 }
612
613 // Perform template argument deduction for the template name.
614 if (Sema::TemplateDeductionResult Result
615 = DeduceTemplateArguments(S,
616 TemplateParams,
617 Param->getTemplateName(),
618 TemplateName(SpecArg->getSpecializedTemplate()),
619 Info, Deduced))
620 return Result;
621
622 // Perform template argument deduction for the template arguments.
623 return DeduceTemplateArguments(S, TemplateParams, Param->template_arguments(),
624 SpecArg->getTemplateArgs().asArray(), Info,
625 Deduced, /*NumberOfArgumentsMustMatch=*/true);
626}
627
628/// Determines whether the given type is an opaque type that
629/// might be more qualified when instantiated.
630static bool IsPossiblyOpaquelyQualifiedType(QualType T) {
631 switch (T->getTypeClass()) {
632 case Type::TypeOfExpr:
633 case Type::TypeOf:
634 case Type::DependentName:
635 case Type::Decltype:
636 case Type::UnresolvedUsing:
637 case Type::TemplateTypeParm:
638 return true;
639
640 case Type::ConstantArray:
641 case Type::IncompleteArray:
642 case Type::VariableArray:
643 case Type::DependentSizedArray:
644 return IsPossiblyOpaquelyQualifiedType(
645 cast<ArrayType>(T)->getElementType());
646
647 default:
648 return false;
649 }
650}
651
652/// Helper function to build a TemplateParameter when we don't
653/// know its type statically.
654static TemplateParameter makeTemplateParameter(Decl *D) {
655 if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(D))
656 return TemplateParameter(TTP);
657 if (NonTypeTemplateParmDecl *NTTP = dyn_cast<NonTypeTemplateParmDecl>(D))
658 return TemplateParameter(NTTP);
659
660 return TemplateParameter(cast<TemplateTemplateParmDecl>(D));
661}
662
663/// A pack that we're currently deducing.
664struct clang::DeducedPack {
665 // The index of the pack.
666 unsigned Index;
667
668 // The old value of the pack before we started deducing it.
669 DeducedTemplateArgument Saved;
670
671 // A deferred value of this pack from an inner deduction, that couldn't be
672 // deduced because this deduction hadn't happened yet.
673 DeducedTemplateArgument DeferredDeduction;
674
675 // The new value of the pack.
676 SmallVector<DeducedTemplateArgument, 4> New;
677
678 // The outer deduction for this pack, if any.
679 DeducedPack *Outer = nullptr;
680
681 DeducedPack(unsigned Index) : Index(Index) {}
682};
683
684namespace {
685
686/// A scope in which we're performing pack deduction.
687class PackDeductionScope {
688public:
689 /// Prepare to deduce the packs named within Pattern.
690 PackDeductionScope(Sema &S, TemplateParameterList *TemplateParams,
691 SmallVectorImpl<DeducedTemplateArgument> &Deduced,
692 TemplateDeductionInfo &Info, TemplateArgument Pattern)
693 : S(S), TemplateParams(TemplateParams), Deduced(Deduced), Info(Info) {
694 unsigned NumNamedPacks = addPacks(Pattern);
695 finishConstruction(NumNamedPacks);
696 }
697
698 /// Prepare to directly deduce arguments of the parameter with index \p Index.
699 PackDeductionScope(Sema &S, TemplateParameterList *TemplateParams,
700 SmallVectorImpl<DeducedTemplateArgument> &Deduced,
701 TemplateDeductionInfo &Info, unsigned Index)
702 : S(S), TemplateParams(TemplateParams), Deduced(Deduced), Info(Info) {
703 addPack(Index);
704 finishConstruction(1);
705 }
706
707private:
708 void addPack(unsigned Index) {
709 // Save the deduced template argument for the parameter pack expanded
710 // by this pack expansion, then clear out the deduction.
711 DeducedPack Pack(Index);
712 Pack.Saved = Deduced[Index];
713 Deduced[Index] = TemplateArgument();
714
715 // FIXME: What if we encounter multiple packs with different numbers of
716 // pre-expanded expansions? (This should already have been diagnosed
717 // during substitution.)
718 if (Optional<unsigned> ExpandedPackExpansions =
719 getExpandedPackSize(TemplateParams->getParam(Index)))
720 FixedNumExpansions = ExpandedPackExpansions;
721
722 Packs.push_back(Pack);
723 }
724
725 unsigned addPacks(TemplateArgument Pattern) {
726 // Compute the set of template parameter indices that correspond to
727 // parameter packs expanded by the pack expansion.
728 llvm::SmallBitVector SawIndices(TemplateParams->size());
729 llvm::SmallVector<TemplateArgument, 4> ExtraDeductions;
730
731 auto AddPack = [&](unsigned Index) {
732 if (SawIndices[Index])
733 return;
734 SawIndices[Index] = true;
735 addPack(Index);
736
737 // Deducing a parameter pack that is a pack expansion also constrains the
738 // packs appearing in that parameter to have the same deduced arity. Also,
739 // in C++17 onwards, deducing a non-type template parameter deduces its
740 // type, so we need to collect the pending deduced values for those packs.
741 if (auto *NTTP = dyn_cast<NonTypeTemplateParmDecl>(
742 TemplateParams->getParam(Index))) {
743 if (!NTTP->isExpandedParameterPack())
744 if (auto *Expansion = dyn_cast<PackExpansionType>(NTTP->getType()))
745 ExtraDeductions.push_back(Expansion->getPattern());
746 }
747 // FIXME: Also collect the unexpanded packs in any type and template
748 // parameter packs that are pack expansions.
749 };
750
751 auto Collect = [&](TemplateArgument Pattern) {
752 SmallVector<UnexpandedParameterPack, 2> Unexpanded;
753 S.collectUnexpandedParameterPacks(Pattern, Unexpanded);
754 for (unsigned I = 0, N = Unexpanded.size(); I != N; ++I) {
755 unsigned Depth, Index;
756 std::tie(Depth, Index) = getDepthAndIndex(Unexpanded[I]);
757 if (Depth == Info.getDeducedDepth())
758 AddPack(Index);
759 }
760 };
761
762 // Look for unexpanded packs in the pattern.
763 Collect(Pattern);
764 assert(!Packs.empty() && "Pack expansion without unexpanded packs?")(static_cast <bool> (!Packs.empty() && "Pack expansion without unexpanded packs?"
) ? void (0) : __assert_fail ("!Packs.empty() && \"Pack expansion without unexpanded packs?\""
, "/build/llvm-toolchain-snapshot-14~++20211110111138+cffbfd01e37b/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 764, __extension__ __PRETTY_FUNCTION__))
;
765
766 unsigned NumNamedPacks = Packs.size();
767
768 // Also look for unexpanded packs that are indirectly deduced by deducing
769 // the sizes of the packs in this pattern.
770 while (!ExtraDeductions.empty())
771 Collect(ExtraDeductions.pop_back_val());
772
773 return NumNamedPacks;
774 }
775
776 void finishConstruction(unsigned NumNamedPacks) {
777 // Dig out the partially-substituted pack, if there is one.
778 const TemplateArgument *PartialPackArgs = nullptr;
779 unsigned NumPartialPackArgs = 0;
780 std::pair<unsigned, unsigned> PartialPackDepthIndex(-1u, -1u);
781 if (auto *Scope = S.CurrentInstantiationScope)
782 if (auto *Partial = Scope->getPartiallySubstitutedPack(
783 &PartialPackArgs, &NumPartialPackArgs))
784 PartialPackDepthIndex = getDepthAndIndex(Partial);
785
786 // This pack expansion will have been partially or fully expanded if
787 // it only names explicitly-specified parameter packs (including the
788 // partially-substituted one, if any).
789 bool IsExpanded = true;
790 for (unsigned I = 0; I != NumNamedPacks; ++I) {
791 if (Packs[I].Index >= Info.getNumExplicitArgs()) {
792 IsExpanded = false;
793 IsPartiallyExpanded = false;
794 break;
795 }
796 if (PartialPackDepthIndex ==
797 std::make_pair(Info.getDeducedDepth(), Packs[I].Index)) {
798 IsPartiallyExpanded = true;
799 }
800 }
801
802 // Skip over the pack elements that were expanded into separate arguments.
803 // If we partially expanded, this is the number of partial arguments.
804 if (IsPartiallyExpanded)
805 PackElements += NumPartialPackArgs;
806 else if (IsExpanded)
807 PackElements += *FixedNumExpansions;
808
809 for (auto &Pack : Packs) {
810 if (Info.PendingDeducedPacks.size() > Pack.Index)
811 Pack.Outer = Info.PendingDeducedPacks[Pack.Index];
812 else
813 Info.PendingDeducedPacks.resize(Pack.Index + 1);
814 Info.PendingDeducedPacks[Pack.Index] = &Pack;
815
816 if (PartialPackDepthIndex ==
817 std::make_pair(Info.getDeducedDepth(), Pack.Index)) {
818 Pack.New.append(PartialPackArgs, PartialPackArgs + NumPartialPackArgs);
819 // We pre-populate the deduced value of the partially-substituted
820 // pack with the specified value. This is not entirely correct: the
821 // value is supposed to have been substituted, not deduced, but the
822 // cases where this is observable require an exact type match anyway.
823 //
824 // FIXME: If we could represent a "depth i, index j, pack elem k"
825 // parameter, we could substitute the partially-substituted pack
826 // everywhere and avoid this.
827 if (!IsPartiallyExpanded)
828 Deduced[Pack.Index] = Pack.New[PackElements];
829 }
830 }
831 }
832
833public:
834 ~PackDeductionScope() {
835 for (auto &Pack : Packs)
836 Info.PendingDeducedPacks[Pack.Index] = Pack.Outer;
837 }
838
839 /// Determine whether this pack has already been partially expanded into a
840 /// sequence of (prior) function parameters / template arguments.
841 bool isPartiallyExpanded() { return IsPartiallyExpanded; }
842
843 /// Determine whether this pack expansion scope has a known, fixed arity.
844 /// This happens if it involves a pack from an outer template that has
845 /// (notionally) already been expanded.
846 bool hasFixedArity() { return FixedNumExpansions.hasValue(); }
847
848 /// Determine whether the next element of the argument is still part of this
849 /// pack. This is the case unless the pack is already expanded to a fixed
850 /// length.
851 bool hasNextElement() {
852 return !FixedNumExpansions || *FixedNumExpansions > PackElements;
853 }
854
855 /// Move to deducing the next element in each pack that is being deduced.
856 void nextPackElement() {
857 // Capture the deduced template arguments for each parameter pack expanded
858 // by this pack expansion, add them to the list of arguments we've deduced
859 // for that pack, then clear out the deduced argument.
860 for (auto &Pack : Packs) {
861 DeducedTemplateArgument &DeducedArg = Deduced[Pack.Index];
862 if (!Pack.New.empty() || !DeducedArg.isNull()) {
863 while (Pack.New.size() < PackElements)
864 Pack.New.push_back(DeducedTemplateArgument());
865 if (Pack.New.size() == PackElements)
866 Pack.New.push_back(DeducedArg);
867 else
868 Pack.New[PackElements] = DeducedArg;
869 DeducedArg = Pack.New.size() > PackElements + 1
870 ? Pack.New[PackElements + 1]
871 : DeducedTemplateArgument();
872 }
873 }
874 ++PackElements;
875 }
876
877 /// Finish template argument deduction for a set of argument packs,
878 /// producing the argument packs and checking for consistency with prior
879 /// deductions.
880 Sema::TemplateDeductionResult finish() {
881 // Build argument packs for each of the parameter packs expanded by this
882 // pack expansion.
883 for (auto &Pack : Packs) {
884 // Put back the old value for this pack.
885 Deduced[Pack.Index] = Pack.Saved;
886
887 // Always make sure the size of this pack is correct, even if we didn't
888 // deduce any values for it.
889 //
890 // FIXME: This isn't required by the normative wording, but substitution
891 // and post-substitution checking will always fail if the arity of any
892 // pack is not equal to the number of elements we processed. (Either that
893 // or something else has gone *very* wrong.) We're permitted to skip any
894 // hard errors from those follow-on steps by the intent (but not the
895 // wording) of C++ [temp.inst]p8:
896 //
897 // If the function selected by overload resolution can be determined
898 // without instantiating a class template definition, it is unspecified
899 // whether that instantiation actually takes place
900 Pack.New.resize(PackElements);
901
902 // Build or find a new value for this pack.
903 DeducedTemplateArgument NewPack;
904 if (Pack.New.empty()) {
905 // If we deduced an empty argument pack, create it now.
906 NewPack = DeducedTemplateArgument(TemplateArgument::getEmptyPack());
907 } else {
908 TemplateArgument *ArgumentPack =
909 new (S.Context) TemplateArgument[Pack.New.size()];
910 std::copy(Pack.New.begin(), Pack.New.end(), ArgumentPack);
911 NewPack = DeducedTemplateArgument(
912 TemplateArgument(llvm::makeArrayRef(ArgumentPack, Pack.New.size())),
913 // FIXME: This is wrong, it's possible that some pack elements are
914 // deduced from an array bound and others are not:
915 // template<typename ...T, T ...V> void g(const T (&...p)[V]);
916 // g({1, 2, 3}, {{}, {}});
917 // ... should deduce T = {int, size_t (from array bound)}.
918 Pack.New[0].wasDeducedFromArrayBound());
919 }
920
921 // Pick where we're going to put the merged pack.
922 DeducedTemplateArgument *Loc;
923 if (Pack.Outer) {
924 if (Pack.Outer->DeferredDeduction.isNull()) {
925 // Defer checking this pack until we have a complete pack to compare
926 // it against.
927 Pack.Outer->DeferredDeduction = NewPack;
928 continue;
929 }
930 Loc = &Pack.Outer->DeferredDeduction;
931 } else {
932 Loc = &Deduced[Pack.Index];
933 }
934
935 // Check the new pack matches any previous value.
936 DeducedTemplateArgument OldPack = *Loc;
937 DeducedTemplateArgument Result =
938 checkDeducedTemplateArguments(S.Context, OldPack, NewPack);
939
940 // If we deferred a deduction of this pack, check that one now too.
941 if (!Result.isNull() && !Pack.DeferredDeduction.isNull()) {
942 OldPack = Result;
943 NewPack = Pack.DeferredDeduction;
944 Result = checkDeducedTemplateArguments(S.Context, OldPack, NewPack);
945 }
946
947 NamedDecl *Param = TemplateParams->getParam(Pack.Index);
948 if (Result.isNull()) {
949 Info.Param = makeTemplateParameter(Param);
950 Info.FirstArg = OldPack;
951 Info.SecondArg = NewPack;
952 return Sema::TDK_Inconsistent;
953 }
954
955 // If we have a pre-expanded pack and we didn't deduce enough elements
956 // for it, fail deduction.
957 if (Optional<unsigned> Expansions = getExpandedPackSize(Param)) {
958 if (*Expansions != PackElements) {
959 Info.Param = makeTemplateParameter(Param);
960 Info.FirstArg = Result;
961 return Sema::TDK_IncompletePack;
962 }
963 }
964
965 *Loc = Result;
966 }
967
968 return Sema::TDK_Success;
969 }
970
971private:
972 Sema &S;
973 TemplateParameterList *TemplateParams;
974 SmallVectorImpl<DeducedTemplateArgument> &Deduced;
975 TemplateDeductionInfo &Info;
976 unsigned PackElements = 0;
977 bool IsPartiallyExpanded = false;
978 /// The number of expansions, if we have a fully-expanded pack in this scope.
979 Optional<unsigned> FixedNumExpansions;
980
981 SmallVector<DeducedPack, 2> Packs;
982};
983
984} // namespace
985
986/// Deduce the template arguments by comparing the list of parameter
987/// types to the list of argument types, as in the parameter-type-lists of
988/// function types (C++ [temp.deduct.type]p10).
989///
990/// \param S The semantic analysis object within which we are deducing
991///
992/// \param TemplateParams The template parameters that we are deducing
993///
994/// \param Params The list of parameter types
995///
996/// \param NumParams The number of types in \c Params
997///
998/// \param Args The list of argument types
999///
1000/// \param NumArgs The number of types in \c Args
1001///
1002/// \param Info information about the template argument deduction itself
1003///
1004/// \param Deduced the deduced template arguments
1005///
1006/// \param TDF bitwise OR of the TemplateDeductionFlags bits that describe
1007/// how template argument deduction is performed.
1008///
1009/// \param PartialOrdering If true, we are performing template argument
1010/// deduction for during partial ordering for a call
1011/// (C++0x [temp.deduct.partial]).
1012///
1013/// \returns the result of template argument deduction so far. Note that a
1014/// "success" result means that template argument deduction has not yet failed,
1015/// but it may still fail, later, for other reasons.
1016static Sema::TemplateDeductionResult
1017DeduceTemplateArguments(Sema &S,
1018 TemplateParameterList *TemplateParams,
1019 const QualType *Params, unsigned NumParams,
1020 const QualType *Args, unsigned NumArgs,
1021 TemplateDeductionInfo &Info,
1022 SmallVectorImpl<DeducedTemplateArgument> &Deduced,
1023 unsigned TDF,
1024 bool PartialOrdering = false) {
1025 // C++0x [temp.deduct.type]p10:
1026 // Similarly, if P has a form that contains (T), then each parameter type
1027 // Pi of the respective parameter-type- list of P is compared with the
1028 // corresponding parameter type Ai of the corresponding parameter-type-list
1029 // of A. [...]
1030 unsigned ArgIdx = 0, ParamIdx = 0;
1031 for (; ParamIdx != NumParams; ++ParamIdx) {
1032 // Check argument types.
1033 const PackExpansionType *Expansion
1034 = dyn_cast<PackExpansionType>(Params[ParamIdx]);
1035 if (!Expansion) {
1036 // Simple case: compare the parameter and argument types at this point.
1037
1038 // Make sure we have an argument.
1039 if (ArgIdx >= NumArgs)
1040 return Sema::TDK_MiscellaneousDeductionFailure;
1041
1042 if (isa<PackExpansionType>(Args[ArgIdx])) {
1043 // C++0x [temp.deduct.type]p22:
1044 // If the original function parameter associated with A is a function
1045 // parameter pack and the function parameter associated with P is not
1046 // a function parameter pack, then template argument deduction fails.
1047 return Sema::TDK_MiscellaneousDeductionFailure;
1048 }
1049
1050 if (Sema::TemplateDeductionResult Result
1051 = DeduceTemplateArgumentsByTypeMatch(S, TemplateParams,
1052 Params[ParamIdx], Args[ArgIdx],
1053 Info, Deduced, TDF,
1054 PartialOrdering))
1055 return Result;
1056
1057 ++ArgIdx;
1058 continue;
1059 }
1060
1061 // C++0x [temp.deduct.type]p10:
1062 // If the parameter-declaration corresponding to Pi is a function
1063 // parameter pack, then the type of its declarator- id is compared with
1064 // each remaining parameter type in the parameter-type-list of A. Each
1065 // comparison deduces template arguments for subsequent positions in the
1066 // template parameter packs expanded by the function parameter pack.
1067
1068 QualType Pattern = Expansion->getPattern();
1069 PackDeductionScope PackScope(S, TemplateParams, Deduced, Info, Pattern);
1070
1071 // A pack scope with fixed arity is not really a pack any more, so is not
1072 // a non-deduced context.
1073 if (ParamIdx + 1 == NumParams || PackScope.hasFixedArity()) {
1074 for (; ArgIdx < NumArgs && PackScope.hasNextElement(); ++ArgIdx) {
1075 // Deduce template arguments from the pattern.
1076 if (Sema::TemplateDeductionResult Result
1077 = DeduceTemplateArgumentsByTypeMatch(S, TemplateParams, Pattern,
1078 Args[ArgIdx], Info, Deduced,
1079 TDF, PartialOrdering))
1080 return Result;
1081
1082 PackScope.nextPackElement();
1083 }
1084 } else {
1085 // C++0x [temp.deduct.type]p5:
1086 // The non-deduced contexts are:
1087 // - A function parameter pack that does not occur at the end of the
1088 // parameter-declaration-clause.
1089 //
1090 // FIXME: There is no wording to say what we should do in this case. We
1091 // choose to resolve this by applying the same rule that is applied for a
1092 // function call: that is, deduce all contained packs to their
1093 // explicitly-specified values (or to <> if there is no such value).
1094 //
1095 // This is seemingly-arbitrarily different from the case of a template-id
1096 // with a non-trailing pack-expansion in its arguments, which renders the
1097 // entire template-argument-list a non-deduced context.
1098
1099 // If the parameter type contains an explicitly-specified pack that we
1100 // could not expand, skip the number of parameters notionally created
1101 // by the expansion.
1102 Optional<unsigned> NumExpansions = Expansion->getNumExpansions();
1103 if (NumExpansions && !PackScope.isPartiallyExpanded()) {
1104 for (unsigned I = 0; I != *NumExpansions && ArgIdx < NumArgs;
1105 ++I, ++ArgIdx)
1106 PackScope.nextPackElement();
1107 }
1108 }
1109
1110 // Build argument packs for each of the parameter packs expanded by this
1111 // pack expansion.
1112 if (auto Result = PackScope.finish())
1113 return Result;
1114 }
1115
1116 // Make sure we don't have any extra arguments.
1117 if (ArgIdx < NumArgs)
1118 return Sema::TDK_MiscellaneousDeductionFailure;
1119
1120 return Sema::TDK_Success;
1121}
1122
1123/// Determine whether the parameter has qualifiers that the argument
1124/// lacks. Put another way, determine whether there is no way to add
1125/// a deduced set of qualifiers to the ParamType that would result in
1126/// its qualifiers matching those of the ArgType.
1127static bool hasInconsistentOrSupersetQualifiersOf(QualType ParamType,
1128 QualType ArgType) {
1129 Qualifiers ParamQs = ParamType.getQualifiers();
1130 Qualifiers ArgQs = ArgType.getQualifiers();
1131
1132 if (ParamQs == ArgQs)
1133 return false;
1134
1135 // Mismatched (but not missing) Objective-C GC attributes.
1136 if (ParamQs.getObjCGCAttr() != ArgQs.getObjCGCAttr() &&
1137 ParamQs.hasObjCGCAttr())
1138 return true;
1139
1140 // Mismatched (but not missing) address spaces.
1141 if (ParamQs.getAddressSpace() != ArgQs.getAddressSpace() &&
1142 ParamQs.hasAddressSpace())
1143 return true;
1144
1145 // Mismatched (but not missing) Objective-C lifetime qualifiers.
1146 if (ParamQs.getObjCLifetime() != ArgQs.getObjCLifetime() &&
1147 ParamQs.hasObjCLifetime())
1148 return true;
1149
1150 // CVR qualifiers inconsistent or a superset.
1151 return (ParamQs.getCVRQualifiers() & ~ArgQs.getCVRQualifiers()) != 0;
1152}
1153
1154/// Compare types for equality with respect to possibly compatible
1155/// function types (noreturn adjustment, implicit calling conventions). If any
1156/// of parameter and argument is not a function, just perform type comparison.
1157///
1158/// \param Param the template parameter type.
1159///
1160/// \param Arg the argument type.
1161bool Sema::isSameOrCompatibleFunctionType(CanQualType Param,
1162 CanQualType Arg) {
1163 const FunctionType *ParamFunction = Param->getAs<FunctionType>(),
1164 *ArgFunction = Arg->getAs<FunctionType>();
1165
1166 // Just compare if not functions.
1167 if (!ParamFunction || !ArgFunction)
1168 return Param == Arg;
1169
1170 // Noreturn and noexcept adjustment.
1171 QualType AdjustedParam;
1172 if (IsFunctionConversion(Param, Arg, AdjustedParam))
1173 return Arg == Context.getCanonicalType(AdjustedParam);
1174
1175 // FIXME: Compatible calling conventions.
1176
1177 return Param == Arg;
1178}
1179
1180/// Get the index of the first template parameter that was originally from the
1181/// innermost template-parameter-list. This is 0 except when we concatenate
1182/// the template parameter lists of a class template and a constructor template
1183/// when forming an implicit deduction guide.
1184static unsigned getFirstInnerIndex(FunctionTemplateDecl *FTD) {
1185 auto *Guide = dyn_cast<CXXDeductionGuideDecl>(FTD->getTemplatedDecl());
1186 if (!Guide || !Guide->isImplicit())
1187 return 0;
1188 return Guide->getDeducedTemplate()->getTemplateParameters()->size();
1189}
1190
1191/// Determine whether a type denotes a forwarding reference.
1192static bool isForwardingReference(QualType Param, unsigned FirstInnerIndex) {
1193 // C++1z [temp.deduct.call]p3:
1194 // A forwarding reference is an rvalue reference to a cv-unqualified
1195 // template parameter that does not represent a template parameter of a
1196 // class template.
1197 if (auto *ParamRef = Param->getAs<RValueReferenceType>()) {
1198 if (ParamRef->getPointeeType().getQualifiers())
1199 return false;
1200 auto *TypeParm = ParamRef->getPointeeType()->getAs<TemplateTypeParmType>();
1201 return TypeParm && TypeParm->getIndex() >= FirstInnerIndex;
1202 }
1203 return false;
1204}
1205
1206/// Attempt to deduce the template arguments by checking the base types
1207/// according to (C++20 [temp.deduct.call] p4b3.
1208///
1209/// \param S the semantic analysis object within which we are deducing.
1210///
1211/// \param RecordT the top level record object we are deducing against.
1212///
1213/// \param TemplateParams the template parameters that we are deducing.
1214///
1215/// \param SpecParam the template specialization parameter type.
1216///
1217/// \param Info information about the template argument deduction itself.
1218///
1219/// \param Deduced the deduced template arguments.
1220///
1221/// \returns the result of template argument deduction with the bases. "invalid"
1222/// means no matches, "success" found a single item, and the
1223/// "MiscellaneousDeductionFailure" result happens when the match is ambiguous.
1224static Sema::TemplateDeductionResult DeduceTemplateBases(
1225 Sema &S, const RecordType *RecordT, TemplateParameterList *TemplateParams,
1226 const TemplateSpecializationType *SpecParam, TemplateDeductionInfo &Info,
1227 SmallVectorImpl<DeducedTemplateArgument> &Deduced) {
1228 // C++14 [temp.deduct.call] p4b3:
1229 // If P is a class and P has the form simple-template-id, then the
1230 // transformed A can be a derived class of the deduced A. Likewise if
1231 // P is a pointer to a class of the form simple-template-id, the
1232 // transformed A can be a pointer to a derived class pointed to by the
1233 // deduced A. However, if there is a class C that is a (direct or
1234 // indirect) base class of D and derived (directly or indirectly) from a
1235 // class B and that would be a valid deduced A, the deduced A cannot be
1236 // B or pointer to B, respectively.
1237 //
1238 // These alternatives are considered only if type deduction would
1239 // otherwise fail. If they yield more than one possible deduced A, the
1240 // type deduction fails.
1241
1242 // Use a breadth-first search through the bases to collect the set of
1243 // successful matches. Visited contains the set of nodes we have already
1244 // visited, while ToVisit is our stack of records that we still need to
1245 // visit. Matches contains a list of matches that have yet to be
1246 // disqualified.
1247 llvm::SmallPtrSet<const RecordType *, 8> Visited;
1248 SmallVector<const RecordType *, 8> ToVisit;
1249 // We iterate over this later, so we have to use MapVector to ensure
1250 // determinism.
1251 llvm::MapVector<const RecordType *, SmallVector<DeducedTemplateArgument, 8>>
1252 Matches;
1253
1254 auto AddBases = [&Visited, &ToVisit](const RecordType *RT) {
1255 CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl());
1256 for (const auto &Base : RD->bases()) {
1257 assert(Base.getType()->isRecordType() &&(static_cast <bool> (Base.getType()->isRecordType() &&
"Base class that isn't a record?") ? void (0) : __assert_fail
("Base.getType()->isRecordType() && \"Base class that isn't a record?\""
, "/build/llvm-toolchain-snapshot-14~++20211110111138+cffbfd01e37b/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 1258, __extension__ __PRETTY_FUNCTION__))
1258 "Base class that isn't a record?")(static_cast <bool> (Base.getType()->isRecordType() &&
"Base class that isn't a record?") ? void (0) : __assert_fail
("Base.getType()->isRecordType() && \"Base class that isn't a record?\""
, "/build/llvm-toolchain-snapshot-14~++20211110111138+cffbfd01e37b/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 1258, __extension__ __PRETTY_FUNCTION__))
;
1259 const RecordType *RT = Base.getType()->getAs<RecordType>();
1260 if (Visited.insert(RT).second)
1261 ToVisit.push_back(Base.getType()->getAs<RecordType>());
1262 }
1263 };
1264
1265 // Set up the loop by adding all the bases.
1266 AddBases(RecordT);
1267
1268 // Search each path of bases until we either run into a successful match
1269 // (where all bases of it are invalid), or we run out of bases.
1270 while (!ToVisit.empty()) {
1271 const RecordType *NextT = ToVisit.pop_back_val();
1272
1273 SmallVector<DeducedTemplateArgument, 8> DeducedCopy(Deduced.begin(),
1274 Deduced.end());
1275 TemplateDeductionInfo BaseInfo(TemplateDeductionInfo::ForBase, Info);
1276 Sema::TemplateDeductionResult BaseResult =
1277 DeduceTemplateArguments(S, TemplateParams, SpecParam,
1278 QualType(NextT, 0), BaseInfo, DeducedCopy);
1279
1280 // If this was a successful deduction, add it to the list of matches,
1281 // otherwise we need to continue searching its bases.
1282 if (BaseResult == Sema::TDK_Success)
1283 Matches.insert({NextT, DeducedCopy});
1284 else
1285 AddBases(NextT);
1286 }
1287
1288 // At this point, 'Matches' contains a list of seemingly valid bases, however
1289 // in the event that we have more than 1 match, it is possible that the base
1290 // of one of the matches might be disqualified for being a base of another
1291 // valid match. We can count on cyclical instantiations being invalid to
1292 // simplify the disqualifications. That is, if A & B are both matches, and B
1293 // inherits from A (disqualifying A), we know that A cannot inherit from B.
1294 if (Matches.size() > 1) {
1295 Visited.clear();
1296 for (const auto &Match : Matches)
1297 AddBases(Match.first);
1298
1299 // We can give up once we have a single item (or have run out of things to
1300 // search) since cyclical inheritance isn't valid.
1301 while (Matches.size() > 1 && !ToVisit.empty()) {
1302 const RecordType *NextT = ToVisit.pop_back_val();
1303 Matches.erase(NextT);
1304
1305 // Always add all bases, since the inheritance tree can contain
1306 // disqualifications for multiple matches.
1307 AddBases(NextT);
1308 }
1309 }
1310
1311 if (Matches.empty())
1312 return Sema::TDK_Invalid;
1313 if (Matches.size() > 1)
1314 return Sema::TDK_MiscellaneousDeductionFailure;
1315
1316 std::swap(Matches.front().second, Deduced);
1317 return Sema::TDK_Success;
1318}
1319
1320/// Deduce the template arguments by comparing the parameter type and
1321/// the argument type (C++ [temp.deduct.type]).
1322///
1323/// \param S the semantic analysis object within which we are deducing
1324///
1325/// \param TemplateParams the template parameters that we are deducing
1326///
1327/// \param ParamIn the parameter type
1328///
1329/// \param ArgIn the argument type
1330///
1331/// \param Info information about the template argument deduction itself
1332///
1333/// \param Deduced the deduced template arguments
1334///
1335/// \param TDF bitwise OR of the TemplateDeductionFlags bits that describe
1336/// how template argument deduction is performed.
1337///
1338/// \param PartialOrdering Whether we're performing template argument deduction
1339/// in the context of partial ordering (C++0x [temp.deduct.partial]).
1340///
1341/// \returns the result of template argument deduction so far. Note that a
1342/// "success" result means that template argument deduction has not yet failed,
1343/// but it may still fail, later, for other reasons.
1344static Sema::TemplateDeductionResult
1345DeduceTemplateArgumentsByTypeMatch(Sema &S,
1346 TemplateParameterList *TemplateParams,
1347 QualType ParamIn, QualType ArgIn,
1348 TemplateDeductionInfo &Info,
1349 SmallVectorImpl<DeducedTemplateArgument> &Deduced,
1350 unsigned TDF,
1351 bool PartialOrdering,
1352 bool DeducedFromArrayBound) {
1353 // We only want to look at the canonical types, since typedefs and
1354 // sugar are not part of template argument deduction.
1355 QualType Param = S.Context.getCanonicalType(ParamIn);
1356 QualType Arg = S.Context.getCanonicalType(ArgIn);
1357
1358 // If the argument type is a pack expansion, look at its pattern.
1359 // This isn't explicitly called out
1360 if (const PackExpansionType *ArgExpansion
0.1
'ArgExpansion' is null
1
Taking false branch
1361 = dyn_cast<PackExpansionType>(Arg)) 1362 Arg = ArgExpansion->getPattern(); 1363 1364 if (PartialOrdering) {
2
Assuming 'PartialOrdering' is false
3
Taking false branch
1365 // C++11 [temp.deduct.partial]p5: 1366 // Before the partial ordering is done, certain transformations are 1367 // performed on the types used for partial ordering: 1368 // - If P is a reference type, P is replaced by the type referred to. 1369 const ReferenceType *ParamRef = Param->getAs<ReferenceType>(); 1370 if (ParamRef) 1371 Param = ParamRef->getPointeeType(); 1372 1373 // - If A is a reference type, A is replaced by the type referred to. 1374 const ReferenceType *ArgRef = Arg->getAs<ReferenceType>(); 1375 if (ArgRef) 1376 Arg = ArgRef->getPointeeType(); 1377 1378 if (ParamRef && ArgRef && S.Context.hasSameUnqualifiedType(Param, Arg)) { 1379 // C++11 [temp.deduct.partial]p9: 1380 // If, for a given type, deduction succeeds in both directions (i.e., 1381 // the types are identical after the transformations above) and both 1382 // P and A were reference types [...]: 1383 // - if [one type] was an lvalue reference and [the other type] was 1384 // not, [the other type] is not considered to be at least as 1385 // specialized as [the first type] 1386 // - if [one type] is more cv-qualified than [the other type], 1387 // [the other type] is not considered to be at least as specialized 1388 // as [the first type] 1389 // Objective-C ARC adds: 1390 // - [one type] has non-trivial lifetime, [the other type] has 1391 // __unsafe_unretained lifetime, and the types are otherwise 1392 // identical 1393 // 1394 // A is "considered to be at least as specialized" as P iff deduction 1395 // succeeds, so we model this as a deduction failure. Note that 1396 // [the first type] is P and [the other type] is A here; the standard 1397 // gets this backwards. 1398 Qualifiers ParamQuals = Param.getQualifiers(); 1399 Qualifiers ArgQuals = Arg.getQualifiers(); 1400 if ((ParamRef->isLValueReferenceType() && 1401 !ArgRef->isLValueReferenceType()) || 1402 ParamQuals.isStrictSupersetOf(ArgQuals) || 1403 (ParamQuals.hasNonTrivialObjCLifetime() && 1404 ArgQuals.getObjCLifetime() == Qualifiers::OCL_ExplicitNone && 1405 ParamQuals.withoutObjCLifetime() == 1406 ArgQuals.withoutObjCLifetime())) { 1407 Info.FirstArg = TemplateArgument(ParamIn); 1408 Info.SecondArg = TemplateArgument(ArgIn); 1409 return Sema::TDK_NonDeducedMismatch; 1410 } 1411 } 1412 1413 // C++11 [temp.deduct.partial]p7: 1414 // Remove any top-level cv-qualifiers: 1415 // - If P is a cv-qualified type, P is replaced by the cv-unqualified 1416 // version of P. 1417 Param = Param.getUnqualifiedType(); 1418 // - If A is a cv-qualified type, A is replaced by the cv-unqualified 1419 // version of A. 1420 Arg = Arg.getUnqualifiedType(); 1421 } else { 1422 // C++0x [temp.deduct.call]p4 bullet 1: 1423 // - If the original P is a reference type, the deduced A (i.e., the type 1424 // referred to by the reference) can be more cv-qualified than the 1425 // transformed A. 1426 if (TDF & TDF_ParamWithReferenceType) {
4
Assuming the condition is false
1427 Qualifiers Quals; 1428 QualType UnqualParam = S.Context.getUnqualifiedArrayType(Param, Quals); 1429 Quals.setCVRQualifiers(Quals.getCVRQualifiers() & 1430 Arg.getCVRQualifiers()); 1431 Param = S.Context.getQualifiedType(UnqualParam, Quals); 1432 } 1433 1434 if ((TDF & TDF_TopLevelParameterTypeList) && !Param->isFunctionType()) {
5
Assuming the condition is false
1435 // C++0x [temp.deduct.type]p10: 1436 // If P and A are function types that originated from deduction when 1437 // taking the address of a function template (14.8.2.2) or when deducing 1438 // template arguments from a function declaration (14.8.2.6) and Pi and 1439 // Ai are parameters of the top-level parameter-type-list of P and A, 1440 // respectively, Pi is adjusted if it is a forwarding reference and Ai 1441 // is an lvalue reference, in 1442 // which case the type of Pi is changed to be the template parameter 1443 // type (i.e., T&& is changed to simply T). [ Note: As a result, when 1444 // Pi is T&& and Ai is X&, the adjusted Pi will be T, causing T to be 1445 // deduced as X&. - end note ] 1446 TDF &= ~TDF_TopLevelParameterTypeList; 1447 if (isForwardingReference(Param, 0) && Arg->isLValueReferenceType()) 1448 Param = Param->getPointeeType(); 1449 } 1450 } 1451 1452 // C++ [temp.deduct.type]p9: 1453 // A template type argument T, a template template argument TT or a 1454 // template non-type argument i can be deduced if P and A have one of 1455 // the following forms: 1456 // 1457 // T 1458 // cv-list T 1459 if (const TemplateTypeParmType *TemplateTypeParm
6.1
'TemplateTypeParm' is null
7
Taking false branch
1460 = Param->getAs<TemplateTypeParmType>()) {
6
Assuming the object is not a 'TemplateTypeParmType'
1461 // Just skip any attempts to deduce from a placeholder type or a parameter 1462 // at a different depth. 1463 if (Arg->isPlaceholderType() || 1464 Info.getDeducedDepth() != TemplateTypeParm->getDepth()) 1465 return Sema::TDK_Success; 1466 1467 unsigned Index = TemplateTypeParm->getIndex(); 1468 bool RecanonicalizeArg = false; 1469 1470 // If the argument type is an array type, move the qualifiers up to the 1471 // top level, so they can be matched with the qualifiers on the parameter. 1472 if (isa<ArrayType>(Arg)) { 1473 Qualifiers Quals; 1474 Arg = S.Context.getUnqualifiedArrayType(Arg, Quals); 1475 if (Quals) { 1476 Arg = S.Context.getQualifiedType(Arg, Quals); 1477 RecanonicalizeArg = true; 1478 } 1479 } 1480 1481 // The argument type can not be less qualified than the parameter 1482 // type. 1483 if (!(TDF & TDF_IgnoreQualifiers) && 1484 hasInconsistentOrSupersetQualifiersOf(Param, Arg)) { 1485 Info.Param = cast<TemplateTypeParmDecl>(TemplateParams->getParam(Index)); 1486 Info.FirstArg = TemplateArgument(Param); 1487 Info.SecondArg = TemplateArgument(Arg); 1488 return Sema::TDK_Underqualified; 1489 } 1490 1491 // Do not match a function type with a cv-qualified type. 1492 // http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#1584 1493 if (Arg->isFunctionType() && Param.hasQualifiers()) { 1494 return Sema::TDK_NonDeducedMismatch; 1495 } 1496 1497 assert(TemplateTypeParm->getDepth() == Info.getDeducedDepth() &&(static_cast <bool> (TemplateTypeParm->getDepth() ==
Info.getDeducedDepth() && "saw template type parameter with wrong depth"
) ? void (0) : __assert_fail ("TemplateTypeParm->getDepth() == Info.getDeducedDepth() && \"saw template type parameter with wrong depth\""
, "/build/llvm-toolchain-snapshot-14~++20211110111138+cffbfd01e37b/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 1498, __extension__ __PRETTY_FUNCTION__))
1498 "saw template type parameter with wrong depth")(static_cast <bool> (TemplateTypeParm->getDepth() ==
Info.getDeducedDepth() && "saw template type parameter with wrong depth"
) ? void (0) : __assert_fail ("TemplateTypeParm->getDepth() == Info.getDeducedDepth() && \"saw template type parameter with wrong depth\""
, "/build/llvm-toolchain-snapshot-14~++20211110111138+cffbfd01e37b/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 1498, __extension__ __PRETTY_FUNCTION__))
; 1499 assert(Arg != S.Context.OverloadTy && "Unresolved overloaded function")(static_cast <bool> (Arg != S.Context.OverloadTy &&
"Unresolved overloaded function") ? void (0) : __assert_fail
("Arg != S.Context.OverloadTy && \"Unresolved overloaded function\""
, "/build/llvm-toolchain-snapshot-14~++20211110111138+cffbfd01e37b/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 1499, __extension__ __PRETTY_FUNCTION__))
; 1500 QualType DeducedType = Arg; 1501 1502 // Remove any qualifiers on the parameter from the deduced type. 1503 // We checked the qualifiers for consistency above. 1504 Qualifiers DeducedQs = DeducedType.getQualifiers(); 1505 Qualifiers ParamQs = Param.getQualifiers(); 1506 DeducedQs.removeCVRQualifiers(ParamQs.getCVRQualifiers()); 1507 if (ParamQs.hasObjCGCAttr()) 1508 DeducedQs.removeObjCGCAttr(); 1509 if (ParamQs.hasAddressSpace()) 1510 DeducedQs.removeAddressSpace(); 1511 if (ParamQs.hasObjCLifetime()) 1512 DeducedQs.removeObjCLifetime(); 1513 1514 // Objective-C ARC: 1515 // If template deduction would produce a lifetime qualifier on a type 1516 // that is not a lifetime type, template argument deduction fails. 1517 if (ParamQs.hasObjCLifetime() && !DeducedType->isObjCLifetimeType() && 1518 !DeducedType->isDependentType()) { 1519 Info.Param = cast<TemplateTypeParmDecl>(TemplateParams->getParam(Index)); 1520 Info.FirstArg = TemplateArgument(Param); 1521 Info.SecondArg = TemplateArgument(Arg); 1522 return Sema::TDK_Underqualified; 1523 } 1524 1525 // Objective-C ARC: 1526 // If template deduction would produce an argument type with lifetime type 1527 // but no lifetime qualifier, the __strong lifetime qualifier is inferred. 1528 if (S.getLangOpts().ObjCAutoRefCount && 1529 DeducedType->isObjCLifetimeType() && 1530 !DeducedQs.hasObjCLifetime()) 1531 DeducedQs.setObjCLifetime(Qualifiers::OCL_Strong); 1532 1533 DeducedType = S.Context.getQualifiedType(DeducedType.getUnqualifiedType(), 1534 DeducedQs); 1535 1536 if (RecanonicalizeArg) 1537 DeducedType = S.Context.getCanonicalType(DeducedType); 1538 1539 DeducedTemplateArgument NewDeduced(DeducedType, DeducedFromArrayBound); 1540 DeducedTemplateArgument Result = checkDeducedTemplateArguments(S.Context, 1541 Deduced[Index], 1542 NewDeduced); 1543 if (Result.isNull()) { 1544 Info.Param = cast<TemplateTypeParmDecl>(TemplateParams->getParam(Index)); 1545 Info.FirstArg = Deduced[Index]; 1546 Info.SecondArg = NewDeduced; 1547 return Sema::TDK_Inconsistent; 1548 } 1549 1550 Deduced[Index] = Result; 1551 return Sema::TDK_Success; 1552 } 1553 1554 // Set up the template argument deduction information for a failure. 1555 Info.FirstArg = TemplateArgument(ParamIn); 1556 Info.SecondArg = TemplateArgument(ArgIn); 1557 1558 // If the parameter is an already-substituted template parameter 1559 // pack, do nothing: we don't know which of its arguments to look 1560 // at, so we have to wait until all of the parameter packs in this 1561 // expansion have arguments. 1562 if (isa<SubstTemplateTypeParmPackType>(Param))
8
Assuming 'Param' is not a 'SubstTemplateTypeParmPackType'
9
Taking false branch
1563 return Sema::TDK_Success; 1564 1565 // Check the cv-qualifiers on the parameter and argument types. 1566 CanQualType CanParam = S.Context.getCanonicalType(Param); 1567 CanQualType CanArg = S.Context.getCanonicalType(Arg); 1568 if (!(TDF & TDF_IgnoreQualifiers)) {
10
Assuming the condition is true
11
Taking true branch
1569 if (TDF & TDF_ParamWithReferenceType) {
12
Taking false branch
1570 if (hasInconsistentOrSupersetQualifiersOf(Param, Arg)) 1571 return Sema::TDK_NonDeducedMismatch; 1572 } else if (TDF & TDF_ArgWithReferenceType) {
13
Assuming the condition is false
14
Taking false branch
1573 // C++ [temp.deduct.conv]p4: 1574 // If the original A is a reference type, A can be more cv-qualified 1575 // than the deduced A 1576 if (!Arg.getQualifiers().compatiblyIncludes(Param.getQualifiers())) 1577 return Sema::TDK_NonDeducedMismatch; 1578 1579 // Strip out all extra qualifiers from the argument to figure out the 1580 // type we're converting to, prior to the qualification conversion. 1581 Qualifiers Quals; 1582 Arg = S.Context.getUnqualifiedArrayType(Arg, Quals); 1583 Arg = S.Context.getQualifiedType(Arg, Param.getQualifiers()); 1584 } else if (!IsPossiblyOpaquelyQualifiedType(Param)) {
15
Taking true branch
1585 if (Param.getCVRQualifiers() != Arg.getCVRQualifiers())
16
Assuming the condition is false
17
Taking false branch
1586 return Sema::TDK_NonDeducedMismatch; 1587 } 1588 1589 // If the parameter type is not dependent, there is nothing to deduce. 1590 if (!Param->isDependentType()) {
18
Assuming the condition is false
19
Taking false branch
1591 if (!(TDF & TDF_SkipNonDependent)) { 1592 bool NonDeduced = 1593 (TDF & TDF_AllowCompatibleFunctionType) 1594 ? !S.isSameOrCompatibleFunctionType(CanParam, CanArg) 1595 : Param != Arg; 1596 if (NonDeduced) { 1597 return Sema::TDK_NonDeducedMismatch; 1598 } 1599 } 1600 return Sema::TDK_Success; 1601 } 1602 } else if (!Param->isDependentType()) { 1603 if (!(TDF & TDF_SkipNonDependent)) { 1604 CanQualType ParamUnqualType = CanParam.getUnqualifiedType(), 1605 ArgUnqualType = CanArg.getUnqualifiedType(); 1606 bool Success = 1607 (TDF & TDF_AllowCompatibleFunctionType) 1608 ? S.isSameOrCompatibleFunctionType(ParamUnqualType, ArgUnqualType) 1609 : ParamUnqualType == ArgUnqualType; 1610 if (Success) 1611 return Sema::TDK_Success; 1612 } else { 1613 return Sema::TDK_Success; 1614 } 1615 } 1616 1617 switch (Param->getTypeClass()) {
20
Control jumps to 'case DependentSizedMatrix:' at line 2137
1618 // Non-canonical types cannot appear here. 1619#define NON_CANONICAL_TYPE(Class, Base) \ 1620 case Type::Class: llvm_unreachable("deducing non-canonical type: " #Class)::llvm::llvm_unreachable_internal("deducing non-canonical type: "
#Class, "/build/llvm-toolchain-snapshot-14~++20211110111138+cffbfd01e37b/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 1620)
;
1621#define TYPE(Class, Base) 1622#include "clang/AST/TypeNodes.inc" 1623 1624 case Type::TemplateTypeParm: 1625 case Type::SubstTemplateTypeParmPack: 1626 llvm_unreachable("Type nodes handled above")::llvm::llvm_unreachable_internal("Type nodes handled above",
"/build/llvm-toolchain-snapshot-14~++20211110111138+cffbfd01e37b/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 1626)
; 1627 1628 // These types cannot be dependent, so simply check whether the types are 1629 // the same. 1630 case Type::Builtin: 1631 case Type::VariableArray: 1632 case Type::Vector: 1633 case Type::FunctionNoProto: 1634 case Type::Record: 1635 case Type::Enum: 1636 case Type::ObjCObject: 1637 case Type::ObjCInterface: 1638 case Type::ObjCObjectPointer: 1639 case Type::ExtInt: 1640 if (TDF & TDF_SkipNonDependent) 1641 return Sema::TDK_Success; 1642 1643 if (TDF & TDF_IgnoreQualifiers) { 1644 Param = Param.getUnqualifiedType(); 1645 Arg = Arg.getUnqualifiedType(); 1646 } 1647 1648 return Param == Arg? Sema::TDK_Success : Sema::TDK_NonDeducedMismatch; 1649 1650 // _Complex T [placeholder extension] 1651 case Type::Complex: 1652 if (const ComplexType *ComplexArg = Arg->getAs<ComplexType>()) 1653 return DeduceTemplateArgumentsByTypeMatch(S, TemplateParams, 1654 cast<ComplexType>(Param)->getElementType(), 1655 ComplexArg->getElementType(), 1656 Info, Deduced, TDF); 1657 1658 return Sema::TDK_NonDeducedMismatch; 1659 1660 // _Atomic T [extension] 1661 case Type::Atomic: 1662 if (const AtomicType *AtomicArg = Arg->getAs<AtomicType>()) 1663 return DeduceTemplateArgumentsByTypeMatch(S, TemplateParams, 1664 cast<AtomicType>(Param)->getValueType(), 1665 AtomicArg->getValueType(), 1666 Info, Deduced, TDF); 1667 1668 return Sema::TDK_NonDeducedMismatch; 1669 1670 // T * 1671 case Type::Pointer: { 1672 QualType PointeeType; 1673 if (const PointerType *PointerArg = Arg->getAs<PointerType>()) { 1674 PointeeType = PointerArg->getPointeeType(); 1675 } else if (const ObjCObjectPointerType *PointerArg 1676 = Arg->getAs<ObjCObjectPointerType>()) { 1677 PointeeType = PointerArg->getPointeeType(); 1678 } else { 1679 return Sema::TDK_NonDeducedMismatch; 1680 } 1681 1682 unsigned SubTDF = TDF & (TDF_IgnoreQualifiers | TDF_DerivedClass); 1683 return DeduceTemplateArgumentsByTypeMatch(S, TemplateParams, 1684 cast<PointerType>(Param)->getPointeeType(), 1685 PointeeType, 1686 Info, Deduced, SubTDF); 1687 } 1688 1689 // T & 1690 case Type::LValueReference: { 1691 const LValueReferenceType *ReferenceArg = 1692 Arg->getAs<LValueReferenceType>(); 1693 if (!ReferenceArg) 1694 return Sema::TDK_NonDeducedMismatch; 1695 1696 return DeduceTemplateArgumentsByTypeMatch(S, TemplateParams, 1697 cast<LValueReferenceType>(Param)->getPointeeType(), 1698 ReferenceArg->getPointeeType(), Info, Deduced, 0); 1699 } 1700 1701 // T && [C++0x] 1702 case Type::RValueReference: { 1703 const RValueReferenceType *ReferenceArg = 1704 Arg->getAs<RValueReferenceType>(); 1705 if (!ReferenceArg) 1706 return Sema::TDK_NonDeducedMismatch; 1707 1708 return DeduceTemplateArgumentsByTypeMatch(S, TemplateParams, 1709 cast<RValueReferenceType>(Param)->getPointeeType(), 1710 ReferenceArg->getPointeeType(), 1711 Info, Deduced, 0); 1712 } 1713 1714 // T [] (implied, but not stated explicitly) 1715 case Type::IncompleteArray: { 1716 const IncompleteArrayType *IncompleteArrayArg = 1717 S.Context.getAsIncompleteArrayType(Arg); 1718 if (!IncompleteArrayArg) 1719 return Sema::TDK_NonDeducedMismatch; 1720 1721 unsigned SubTDF = TDF & TDF_IgnoreQualifiers; 1722 return DeduceTemplateArgumentsByTypeMatch(S, TemplateParams, 1723 S.Context.getAsIncompleteArrayType(Param)->getElementType(), 1724 IncompleteArrayArg->getElementType(), 1725 Info, Deduced, SubTDF); 1726 } 1727 1728 // T [integer-constant] 1729 case Type::ConstantArray: { 1730 const ConstantArrayType *ConstantArrayArg = 1731 S.Context.getAsConstantArrayType(Arg); 1732 if (!ConstantArrayArg) 1733 return Sema::TDK_NonDeducedMismatch; 1734 1735 const ConstantArrayType *ConstantArrayParm = 1736 S.Context.getAsConstantArrayType(Param); 1737 if (ConstantArrayArg->getSize() != ConstantArrayParm->getSize()) 1738 return Sema::TDK_NonDeducedMismatch; 1739 1740 unsigned SubTDF = TDF & TDF_IgnoreQualifiers; 1741 return DeduceTemplateArgumentsByTypeMatch(S, TemplateParams, 1742 ConstantArrayParm->getElementType(), 1743 ConstantArrayArg->getElementType(), 1744 Info, Deduced, SubTDF); 1745 } 1746 1747 // type [i] 1748 case Type::DependentSizedArray: { 1749 const ArrayType *ArrayArg = S.Context.getAsArrayType(Arg); 1750 if (!ArrayArg) 1751 return Sema::TDK_NonDeducedMismatch; 1752 1753 unsigned SubTDF = TDF & TDF_IgnoreQualifiers; 1754 1755 // Check the element type of the arrays 1756 const DependentSizedArrayType *DependentArrayParm 1757 = S.Context.getAsDependentSizedArrayType(Param); 1758 if (Sema::TemplateDeductionResult Result 1759 = DeduceTemplateArgumentsByTypeMatch(S, TemplateParams, 1760 DependentArrayParm->getElementType(), 1761 ArrayArg->getElementType(), 1762 Info, Deduced, SubTDF)) 1763 return Result; 1764 1765 // Determine the array bound is something we can deduce. 1766 const NonTypeTemplateParmDecl *NTTP 1767 = getDeducedParameterFromExpr(Info, DependentArrayParm->getSizeExpr()); 1768 if (!NTTP) 1769 return Sema::TDK_Success; 1770 1771 // We can perform template argument deduction for the given non-type 1772 // template parameter. 1773 assert(NTTP->getDepth() == Info.getDeducedDepth() &&(static_cast <bool> (NTTP->getDepth() == Info.getDeducedDepth
() && "saw non-type template parameter with wrong depth"
) ? void (0) : __assert_fail ("NTTP->getDepth() == Info.getDeducedDepth() && \"saw non-type template parameter with wrong depth\""
, "/build/llvm-toolchain-snapshot-14~++20211110111138+cffbfd01e37b/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 1774, __extension__ __PRETTY_FUNCTION__))
1774 "saw non-type template parameter with wrong depth")(static_cast <bool> (NTTP->getDepth() == Info.getDeducedDepth
() && "saw non-type template parameter with wrong depth"
) ? void (0) : __assert_fail ("NTTP->getDepth() == Info.getDeducedDepth() && \"saw non-type template parameter with wrong depth\""
, "/build/llvm-toolchain-snapshot-14~++20211110111138+cffbfd01e37b/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 1774, __extension__ __PRETTY_FUNCTION__))
; 1775 if (const ConstantArrayType *ConstantArrayArg 1776 = dyn_cast<ConstantArrayType>(ArrayArg)) { 1777 llvm::APSInt Size(ConstantArrayArg->getSize()); 1778 return DeduceNonTypeTemplateArgument(S, TemplateParams, NTTP, Size, 1779 S.Context.getSizeType(), 1780 /*ArrayBound=*/true, 1781 Info, Deduced); 1782 } 1783 if (const DependentSizedArrayType *DependentArrayArg 1784 = dyn_cast<DependentSizedArrayType>(ArrayArg)) 1785 if (DependentArrayArg->getSizeExpr()) 1786 return DeduceNonTypeTemplateArgument(S, TemplateParams, NTTP, 1787 DependentArrayArg->getSizeExpr(), 1788 Info, Deduced); 1789 1790 // Incomplete type does not match a dependently-sized array type 1791 return Sema::TDK_NonDeducedMismatch; 1792 } 1793 1794 // type(*)(T) 1795 // T(*)() 1796 // T(*)(T) 1797 case Type::FunctionProto: { 1798 unsigned SubTDF = TDF & TDF_TopLevelParameterTypeList; 1799 const FunctionProtoType *FunctionProtoArg = 1800 dyn_cast<FunctionProtoType>(Arg); 1801 if (!FunctionProtoArg) 1802 return Sema::TDK_NonDeducedMismatch; 1803 1804 const FunctionProtoType *FunctionProtoParam = 1805 cast<FunctionProtoType>(Param); 1806 1807 if (FunctionProtoParam->getMethodQuals() 1808 != FunctionProtoArg->getMethodQuals() || 1809 FunctionProtoParam->getRefQualifier() 1810 != FunctionProtoArg->getRefQualifier() || 1811 FunctionProtoParam->isVariadic() != FunctionProtoArg->isVariadic()) 1812 return Sema::TDK_NonDeducedMismatch; 1813 1814 // Check return types. 1815 if (auto Result = DeduceTemplateArgumentsByTypeMatch( 1816 S, TemplateParams, FunctionProtoParam->getReturnType(), 1817 FunctionProtoArg->getReturnType(), Info, Deduced, 0)) 1818 return Result; 1819 1820 // Check parameter types. 1821 if (auto Result = DeduceTemplateArguments( 1822 S, TemplateParams, FunctionProtoParam->param_type_begin(), 1823 FunctionProtoParam->getNumParams(), 1824 FunctionProtoArg->param_type_begin(), 1825 FunctionProtoArg->getNumParams(), Info, Deduced, SubTDF)) 1826 return Result; 1827 1828 if (TDF & TDF_AllowCompatibleFunctionType) 1829 return Sema::TDK_Success; 1830 1831 // FIXME: Per core-2016/10/1019 (no corresponding core issue yet), permit 1832 // deducing through the noexcept-specifier if it's part of the canonical 1833 // type. libstdc++ relies on this. 1834 Expr *NoexceptExpr = FunctionProtoParam->getNoexceptExpr(); 1835 if (const NonTypeTemplateParmDecl *NTTP = 1836 NoexceptExpr ? getDeducedParameterFromExpr(Info, NoexceptExpr) 1837 : nullptr) { 1838 assert(NTTP->getDepth() == Info.getDeducedDepth() &&(static_cast <bool> (NTTP->getDepth() == Info.getDeducedDepth
() && "saw non-type template parameter with wrong depth"
) ? void (0) : __assert_fail ("NTTP->getDepth() == Info.getDeducedDepth() && \"saw non-type template parameter with wrong depth\""
, "/build/llvm-toolchain-snapshot-14~++20211110111138+cffbfd01e37b/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 1839, __extension__ __PRETTY_FUNCTION__))
1839 "saw non-type template parameter with wrong depth")(static_cast <bool> (NTTP->getDepth() == Info.getDeducedDepth
() && "saw non-type template parameter with wrong depth"
) ? void (0) : __assert_fail ("NTTP->getDepth() == Info.getDeducedDepth() && \"saw non-type template parameter with wrong depth\""
, "/build/llvm-toolchain-snapshot-14~++20211110111138+cffbfd01e37b/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 1839, __extension__ __PRETTY_FUNCTION__))
; 1840 1841 llvm::APSInt Noexcept(1); 1842 switch (FunctionProtoArg->canThrow()) { 1843 case CT_Cannot: 1844 Noexcept = 1; 1845 LLVM_FALLTHROUGH[[gnu::fallthrough]]; 1846 1847 case CT_Can: 1848 // We give E in noexcept(E) the "deduced from array bound" treatment. 1849 // FIXME: Should we? 1850 return DeduceNonTypeTemplateArgument( 1851 S, TemplateParams, NTTP, Noexcept, S.Context.BoolTy, 1852 /*ArrayBound*/true, Info, Deduced); 1853 1854 case CT_Dependent: 1855 if (Expr *ArgNoexceptExpr = FunctionProtoArg->getNoexceptExpr()) 1856 return DeduceNonTypeTemplateArgument( 1857 S, TemplateParams, NTTP, ArgNoexceptExpr, Info, Deduced); 1858 // Can't deduce anything from throw(T...). 1859 break; 1860 } 1861 } 1862 // FIXME: Detect non-deduced exception specification mismatches? 1863 // 1864 // Careful about [temp.deduct.call] and [temp.deduct.conv], which allow 1865 // top-level differences in noexcept-specifications. 1866 1867 return Sema::TDK_Success; 1868 } 1869 1870 case Type::InjectedClassName: 1871 // Treat a template's injected-class-name as if the template 1872 // specialization type had been used. 1873 Param = cast<InjectedClassNameType>(Param) 1874 ->getInjectedSpecializationType(); 1875 assert(isa<TemplateSpecializationType>(Param) &&(static_cast <bool> (isa<TemplateSpecializationType>
(Param) && "injected class name is not a template specialization type"
) ? void (0) : __assert_fail ("isa<TemplateSpecializationType>(Param) && \"injected class name is not a template specialization type\""
, "/build/llvm-toolchain-snapshot-14~++20211110111138+cffbfd01e37b/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 1876, __extension__ __PRETTY_FUNCTION__))
1876 "injected class name is not a template specialization type")(static_cast <bool> (isa<TemplateSpecializationType>
(Param) && "injected class name is not a template specialization type"
) ? void (0) : __assert_fail ("isa<TemplateSpecializationType>(Param) && \"injected class name is not a template specialization type\""
, "/build/llvm-toolchain-snapshot-14~++20211110111138+cffbfd01e37b/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 1876, __extension__ __PRETTY_FUNCTION__))
; 1877 LLVM_FALLTHROUGH[[gnu::fallthrough]]; 1878 1879 // template-name<T> (where template-name refers to a class template) 1880 // template-name<i> 1881 // TT<T> 1882 // TT<i> 1883 // TT<> 1884 case Type::TemplateSpecialization: { 1885 const TemplateSpecializationType *SpecParam = 1886 cast<TemplateSpecializationType>(Param); 1887 1888 // When Arg cannot be a derived class, we can just try to deduce template 1889 // arguments from the template-id. 1890 const RecordType *RecordT = Arg->getAs<RecordType>(); 1891 if (!(TDF & TDF_DerivedClass) || !RecordT) 1892 return DeduceTemplateArguments(S, TemplateParams, SpecParam, Arg, Info, 1893 Deduced); 1894 1895 SmallVector<DeducedTemplateArgument, 8> DeducedOrig(Deduced.begin(), 1896 Deduced.end()); 1897 1898 Sema::TemplateDeductionResult Result = DeduceTemplateArguments( 1899 S, TemplateParams, SpecParam, Arg, Info, Deduced); 1900 1901 if (Result == Sema::TDK_Success) 1902 return Result; 1903 1904 // We cannot inspect base classes as part of deduction when the type 1905 // is incomplete, so either instantiate any templates necessary to 1906 // complete the type, or skip over it if it cannot be completed. 1907 if (!S.isCompleteType(Info.getLocation(), Arg)) 1908 return Result; 1909 1910 // Reset the incorrectly deduced argument from above. 1911 Deduced = DeducedOrig; 1912 1913 // Check bases according to C++14 [temp.deduct.call] p4b3: 1914 Sema::TemplateDeductionResult BaseResult = DeduceTemplateBases( 1915 S, RecordT, TemplateParams, SpecParam, Info, Deduced); 1916 1917 if (BaseResult != Sema::TDK_Invalid) 1918 return BaseResult; 1919 return Result; 1920 } 1921 1922 // T type::* 1923 // T T::* 1924 // T (type::*)() 1925 // type (T::*)() 1926 // type (type::*)(T) 1927 // type (T::*)(T) 1928 // T (type::*)(T) 1929 // T (T::*)() 1930 // T (T::*)(T) 1931 case Type::MemberPointer: { 1932 const MemberPointerType *MemPtrParam = cast<MemberPointerType>(Param); 1933 const MemberPointerType *MemPtrArg = dyn_cast<MemberPointerType>(Arg); 1934 if (!MemPtrArg) 1935 return Sema::TDK_NonDeducedMismatch; 1936 1937 QualType ParamPointeeType = MemPtrParam->getPointeeType(); 1938 if (ParamPointeeType->isFunctionType()) 1939 S.adjustMemberFunctionCC(ParamPointeeType, /*IsStatic=*/true, 1940 /*IsCtorOrDtor=*/false, Info.getLocation()); 1941 QualType ArgPointeeType = MemPtrArg->getPointeeType(); 1942 if (ArgPointeeType->isFunctionType()) 1943 S.adjustMemberFunctionCC(ArgPointeeType, /*IsStatic=*/true, 1944 /*IsCtorOrDtor=*/false, Info.getLocation()); 1945 1946 if (Sema::TemplateDeductionResult Result 1947 = DeduceTemplateArgumentsByTypeMatch(S, TemplateParams, 1948 ParamPointeeType, 1949 ArgPointeeType, 1950 Info, Deduced, 1951 TDF & TDF_IgnoreQualifiers)) 1952 return Result; 1953 1954 return DeduceTemplateArgumentsByTypeMatch(S, TemplateParams, 1955 QualType(MemPtrParam->getClass(), 0), 1956 QualType(MemPtrArg->getClass(), 0), 1957 Info, Deduced, 1958 TDF & TDF_IgnoreQualifiers); 1959 } 1960 1961 // (clang extension) 1962 // 1963 // type(^)(T) 1964 // T(^)() 1965 // T(^)(T) 1966 case Type::BlockPointer: { 1967 const BlockPointerType *BlockPtrParam = cast<BlockPointerType>(Param); 1968 const BlockPointerType *BlockPtrArg = dyn_cast<BlockPointerType>(Arg); 1969 1970 if (!BlockPtrArg) 1971 return Sema::TDK_NonDeducedMismatch; 1972 1973 return DeduceTemplateArgumentsByTypeMatch(S, TemplateParams, 1974 BlockPtrParam->getPointeeType(), 1975 BlockPtrArg->getPointeeType(), 1976 Info, Deduced, 0); 1977 } 1978 1979 // (clang extension) 1980 // 1981 // T __attribute__(((ext_vector_type(<integral constant>)))) 1982 case Type::ExtVector: { 1983 const ExtVectorType *VectorParam = cast<ExtVectorType>(Param); 1984 if (const ExtVectorType *VectorArg = dyn_cast<ExtVectorType>(Arg)) { 1985 // Make sure that the vectors have the same number of elements. 1986 if (VectorParam->getNumElements() != VectorArg->getNumElements()) 1987 return Sema::TDK_NonDeducedMismatch; 1988 1989 // Perform deduction on the element types. 1990 return DeduceTemplateArgumentsByTypeMatch(S, TemplateParams, 1991 VectorParam->getElementType(), 1992 VectorArg->getElementType(), 1993 Info, Deduced, TDF); 1994 } 1995 1996 if (const DependentSizedExtVectorType *VectorArg 1997 = dyn_cast<DependentSizedExtVectorType>(Arg)) { 1998 // We can't check the number of elements, since the argument has a 1999 // dependent number of elements. This can only occur during partial 2000 // ordering. 2001 2002 // Perform deduction on the element types. 2003 return DeduceTemplateArgumentsByTypeMatch(S, TemplateParams, 2004 VectorParam->getElementType(), 2005 VectorArg->getElementType(), 2006 Info, Deduced, TDF); 2007 } 2008 2009 return Sema::TDK_NonDeducedMismatch; 2010 } 2011 2012 case Type::DependentVector: { 2013 const auto *VectorParam = cast<DependentVectorType>(Param); 2014 2015 if (const auto *VectorArg = dyn_cast<VectorType>(Arg)) { 2016 // Perform deduction on the element types. 2017 if (Sema::TemplateDeductionResult Result = 2018 DeduceTemplateArgumentsByTypeMatch( 2019 S, TemplateParams, VectorParam->getElementType(), 2020 VectorArg->getElementType(), Info, Deduced, TDF)) 2021 return Result; 2022 2023 // Perform deduction on the vector size, if we can. 2024 const NonTypeTemplateParmDecl *NTTP = 2025 getDeducedParameterFromExpr(Info, VectorParam->getSizeExpr()); 2026 if (!NTTP) 2027 return Sema::TDK_Success; 2028 2029 llvm::APSInt ArgSize(S.Context.getTypeSize(S.Context.IntTy), false); 2030 ArgSize = VectorArg->getNumElements(); 2031 // Note that we use the "array bound" rules here; just like in that 2032 // case, we don't have any particular type for the vector size, but 2033 // we can provide one if necessary. 2034 return DeduceNonTypeTemplateArgument(S, TemplateParams, NTTP, ArgSize, 2035 S.Context.UnsignedIntTy, true, 2036 Info, Deduced); 2037 } 2038 2039 if (const auto *VectorArg = dyn_cast<DependentVectorType>(Arg)) { 2040 // Perform deduction on the element types. 2041 if (Sema::TemplateDeductionResult Result = 2042 DeduceTemplateArgumentsByTypeMatch( 2043 S, TemplateParams, VectorParam->getElementType(), 2044 VectorArg->getElementType(), Info, Deduced, TDF)) 2045 return Result; 2046 2047 // Perform deduction on the vector size, if we can. 2048 const NonTypeTemplateParmDecl *NTTP = getDeducedParameterFromExpr( 2049 Info, VectorParam->getSizeExpr()); 2050 if (!NTTP) 2051 return Sema::TDK_Success; 2052 2053 return DeduceNonTypeTemplateArgument( 2054 S, TemplateParams, NTTP, VectorArg->getSizeExpr(), Info, Deduced); 2055 } 2056 2057 return Sema::TDK_NonDeducedMismatch; 2058 } 2059 2060 // (clang extension) 2061 // 2062 // T __attribute__(((ext_vector_type(N)))) 2063 case Type::DependentSizedExtVector: { 2064 const DependentSizedExtVectorType *VectorParam 2065 = cast<DependentSizedExtVectorType>(Param); 2066 2067 if (const ExtVectorType *VectorArg = dyn_cast<ExtVectorType>(Arg)) { 2068 // Perform deduction on the element types. 2069 if (Sema::TemplateDeductionResult Result 2070 = DeduceTemplateArgumentsByTypeMatch(S, TemplateParams, 2071 VectorParam->getElementType(), 2072 VectorArg->getElementType(), 2073 Info, Deduced, TDF)) 2074 return Result; 2075 2076 // Perform deduction on the vector size, if we can. 2077 const NonTypeTemplateParmDecl *NTTP = 2078 getDeducedParameterFromExpr(Info, VectorParam->getSizeExpr()); 2079 if (!NTTP) 2080 return Sema::TDK_Success; 2081 2082 llvm::APSInt ArgSize(S.Context.getTypeSize(S.Context.IntTy), false); 2083 ArgSize = VectorArg->getNumElements(); 2084 // Note that we use the "array bound" rules here; just like in that 2085 // case, we don't have any particular type for the vector size, but 2086 // we can provide one if necessary. 2087 return DeduceNonTypeTemplateArgument(S, TemplateParams, NTTP, ArgSize, 2088 S.Context.IntTy, true, Info, 2089 Deduced); 2090 } 2091 2092 if (const DependentSizedExtVectorType *VectorArg 2093 = dyn_cast<DependentSizedExtVectorType>(Arg)) { 2094 // Perform deduction on the element types. 2095 if (Sema::TemplateDeductionResult Result 2096 = DeduceTemplateArgumentsByTypeMatch(S, TemplateParams, 2097 VectorParam->getElementType(), 2098 VectorArg->getElementType(), 2099 Info, Deduced, TDF)) 2100 return Result; 2101 2102 // Perform deduction on the vector size, if we can. 2103 const NonTypeTemplateParmDecl *NTTP = 2104 getDeducedParameterFromExpr(Info, VectorParam->getSizeExpr()); 2105 if (!NTTP) 2106 return Sema::TDK_Success; 2107 2108 return DeduceNonTypeTemplateArgument(S, TemplateParams, NTTP, 2109 VectorArg->getSizeExpr(), 2110 Info, Deduced); 2111 } 2112 2113 return Sema::TDK_NonDeducedMismatch; 2114 } 2115 2116 // (clang extension) 2117 // 2118 // T __attribute__((matrix_type(<integral constant>, 2119 // <integral constant>))) 2120 case Type::ConstantMatrix: { 2121 const ConstantMatrixType *MatrixArg = dyn_cast<ConstantMatrixType>(Arg); 2122 if (!MatrixArg) 2123 return Sema::TDK_NonDeducedMismatch; 2124 2125 const ConstantMatrixType *MatrixParam = cast<ConstantMatrixType>(Param); 2126 // Check that the dimensions are the same 2127 if (MatrixParam->getNumRows() != MatrixArg->getNumRows() || 2128 MatrixParam->getNumColumns() != MatrixArg->getNumColumns()) { 2129 return Sema::TDK_NonDeducedMismatch; 2130 } 2131 // Perform deduction on element types. 2132 return DeduceTemplateArgumentsByTypeMatch( 2133 S, TemplateParams, MatrixParam->getElementType(), 2134 MatrixArg->getElementType(), Info, Deduced, TDF); 2135 } 2136 2137 case Type::DependentSizedMatrix: { 2138 const MatrixType *MatrixArg = dyn_cast<MatrixType>(Arg); 2139 if (!MatrixArg)
21
Assuming 'MatrixArg' is non-null
22
Taking false branch
2140 return Sema::TDK_NonDeducedMismatch; 2141 2142 // Check the element type of the matrixes. 2143 const DependentSizedMatrixType *MatrixParam = 2144 cast<DependentSizedMatrixType>(Param); 2145 if (Sema::TemplateDeductionResult Result =
23
Assuming 'Result' is 0
24
Taking false branch
2146 DeduceTemplateArgumentsByTypeMatch( 2147 S, TemplateParams, MatrixParam->getElementType(), 2148 MatrixArg->getElementType(), Info, Deduced, TDF)) 2149 return Result; 2150 2151 // Try to deduce a matrix dimension. 2152 auto DeduceMatrixArg = 2153 [&S, &Info, &Deduced, &TemplateParams]( 2154 Expr *ParamExpr, const MatrixType *Arg, 2155 unsigned (ConstantMatrixType::*GetArgDimension)() const, 2156 Expr *(DependentSizedMatrixType::*GetArgDimensionExpr)() const) { 2157 const auto *ArgConstMatrix = dyn_cast<ConstantMatrixType>(Arg);
26
Assuming 'Arg' is not a 'ConstantMatrixType'
2158 const auto *ArgDepMatrix = dyn_cast<DependentSizedMatrixType>(Arg);
27
Assuming 'Arg' is not a 'DependentSizedMatrixType'
28
'ArgDepMatrix' initialized to a null pointer value
2159 if (!ParamExpr->isValueDependent()) {
29
Assuming the condition is true
30
Taking true branch
2160 Optional<llvm::APSInt> ParamConst = 2161 ParamExpr->getIntegerConstantExpr(S.Context); 2162 if (!ParamConst)
31
Assuming the condition is false
32
Taking false branch
2163 return Sema::TDK_NonDeducedMismatch; 2164 2165 if (ArgConstMatrix
32.1
'ArgConstMatrix' is null
) {
33
Taking false branch
2166 if ((ArgConstMatrix->*GetArgDimension)() == *ParamConst) 2167 return Sema::TDK_Success; 2168 return Sema::TDK_NonDeducedMismatch; 2169 } 2170 2171 Expr *ArgExpr = (ArgDepMatrix->*GetArgDimensionExpr)();
34
Called C++ object pointer is null
2172 if (Optional<llvm::APSInt> ArgConst = 2173 ArgExpr->getIntegerConstantExpr(S.Context)) 2174 if (*ArgConst == *ParamConst) 2175 return Sema::TDK_Success; 2176 return Sema::TDK_NonDeducedMismatch; 2177 } 2178 2179 const NonTypeTemplateParmDecl *NTTP = 2180 getDeducedParameterFromExpr(Info, ParamExpr); 2181 if (!NTTP) 2182 return Sema::TDK_Success; 2183 2184 if (ArgConstMatrix) { 2185 llvm::APSInt ArgConst( 2186 S.Context.getTypeSize(S.Context.getSizeType())); 2187 ArgConst = (ArgConstMatrix->*GetArgDimension)(); 2188 return DeduceNonTypeTemplateArgument( 2189 S, TemplateParams, NTTP, ArgConst, S.Context.getSizeType(), 2190 /*ArrayBound=*/true, Info, Deduced); 2191 } 2192 2193 return DeduceNonTypeTemplateArgument( 2194 S, TemplateParams, NTTP, (ArgDepMatrix->*GetArgDimensionExpr)(), 2195 Info, Deduced); 2196 }; 2197 2198 auto Result = DeduceMatrixArg(MatrixParam->getRowExpr(), MatrixArg,
25
Calling 'operator()'
2199 &ConstantMatrixType::getNumRows, 2200 &DependentSizedMatrixType::getRowExpr); 2201 if (Result) 2202 return Result; 2203 2204 return DeduceMatrixArg(MatrixParam->getColumnExpr(), MatrixArg, 2205 &ConstantMatrixType::getNumColumns, 2206 &DependentSizedMatrixType::getColumnExpr); 2207 } 2208 2209 // (clang extension) 2210 // 2211 // T __attribute__(((address_space(N)))) 2212 case Type::DependentAddressSpace: { 2213 const DependentAddressSpaceType *AddressSpaceParam = 2214 cast<DependentAddressSpaceType>(Param); 2215 2216 if (const DependentAddressSpaceType *AddressSpaceArg = 2217 dyn_cast<DependentAddressSpaceType>(Arg)) { 2218 // Perform deduction on the pointer type. 2219 if (Sema::TemplateDeductionResult Result = 2220 DeduceTemplateArgumentsByTypeMatch( 2221 S, TemplateParams, AddressSpaceParam->getPointeeType(), 2222 AddressSpaceArg->getPointeeType(), Info, Deduced, TDF)) 2223 return Result; 2224 2225 // Perform deduction on the address space, if we can. 2226 const NonTypeTemplateParmDecl *NTTP = getDeducedParameterFromExpr( 2227 Info, AddressSpaceParam->getAddrSpaceExpr()); 2228 if (!NTTP) 2229 return Sema::TDK_Success; 2230 2231 return DeduceNonTypeTemplateArgument( 2232 S, TemplateParams, NTTP, AddressSpaceArg->getAddrSpaceExpr(), Info, 2233 Deduced); 2234 } 2235 2236 if (isTargetAddressSpace(Arg.getAddressSpace())) { 2237 llvm::APSInt ArgAddressSpace(S.Context.getTypeSize(S.Context.IntTy), 2238 false); 2239 ArgAddressSpace = toTargetAddressSpace(Arg.getAddressSpace()); 2240 2241 // Perform deduction on the pointer types. 2242 if (Sema::TemplateDeductionResult Result = 2243 DeduceTemplateArgumentsByTypeMatch( 2244 S, TemplateParams, AddressSpaceParam->getPointeeType(), 2245 S.Context.removeAddrSpaceQualType(Arg), Info, Deduced, TDF)) 2246 return Result; 2247 2248 // Perform deduction on the address space, if we can. 2249 const NonTypeTemplateParmDecl *NTTP = getDeducedParameterFromExpr( 2250 Info, AddressSpaceParam->getAddrSpaceExpr()); 2251 if (!NTTP) 2252 return Sema::TDK_Success; 2253 2254 return DeduceNonTypeTemplateArgument(S, TemplateParams, NTTP, 2255 ArgAddressSpace, S.Context.IntTy, 2256 true, Info, Deduced); 2257 } 2258 2259 return Sema::TDK_NonDeducedMismatch; 2260 } 2261 case Type::DependentExtInt: { 2262 const auto *IntParam = cast<DependentExtIntType>(Param); 2263 2264 if (const auto *IntArg = dyn_cast<ExtIntType>(Arg)){ 2265 if (IntParam->isUnsigned() != IntArg->isUnsigned()) 2266 return Sema::TDK_NonDeducedMismatch; 2267 2268 const NonTypeTemplateParmDecl *NTTP = 2269 getDeducedParameterFromExpr(Info, IntParam->getNumBitsExpr()); 2270 if (!NTTP) 2271 return Sema::TDK_Success; 2272 2273 llvm::APSInt ArgSize(S.Context.getTypeSize(S.Context.IntTy), false); 2274 ArgSize = IntArg->getNumBits(); 2275 2276 return DeduceNonTypeTemplateArgument(S, TemplateParams, NTTP, ArgSize, 2277 S.Context.IntTy, true, Info, 2278 Deduced); 2279 } 2280 2281 if (const auto *IntArg = dyn_cast<DependentExtIntType>(Arg)) { 2282 if (IntParam->isUnsigned() != IntArg->isUnsigned()) 2283 return Sema::TDK_NonDeducedMismatch; 2284 return Sema::TDK_Success; 2285 } 2286 return Sema::TDK_NonDeducedMismatch; 2287 } 2288 2289 case Type::TypeOfExpr: 2290 case Type::TypeOf: 2291 case Type::DependentName: 2292 case Type::UnresolvedUsing: 2293 case Type::Decltype: 2294 case Type::UnaryTransform: 2295 case Type::Auto: 2296 case Type::DeducedTemplateSpecialization: 2297 case Type::DependentTemplateSpecialization: 2298 case Type::PackExpansion: 2299 case Type::Pipe: 2300 // No template argument deduction for these types 2301 return Sema::TDK_Success; 2302 } 2303 2304 llvm_unreachable("Invalid Type Class!")::llvm::llvm_unreachable_internal("Invalid Type Class!", "/build/llvm-toolchain-snapshot-14~++20211110111138+cffbfd01e37b/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 2304)
; 2305} 2306 2307static Sema::TemplateDeductionResult 2308DeduceTemplateArguments(Sema &S, 2309 TemplateParameterList *TemplateParams, 2310 const TemplateArgument &Param, 2311 TemplateArgument Arg, 2312 TemplateDeductionInfo &Info, 2313 SmallVectorImpl<DeducedTemplateArgument> &Deduced) { 2314 // If the template argument is a pack expansion, perform template argument 2315 // deduction against the pattern of that expansion. This only occurs during 2316 // partial ordering. 2317 if (Arg.isPackExpansion()) 2318 Arg = Arg.getPackExpansionPattern(); 2319 2320 switch (Param.getKind()) { 2321 case TemplateArgument::Null: 2322 llvm_unreachable("Null template argument in parameter list")::llvm::llvm_unreachable_internal("Null template argument in parameter list"
, "/build/llvm-toolchain-snapshot-14~++20211110111138+cffbfd01e37b/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 2322)
; 2323 2324 case TemplateArgument::Type: 2325 if (Arg.getKind() == TemplateArgument::Type) 2326 return DeduceTemplateArgumentsByTypeMatch(S, TemplateParams, 2327 Param.getAsType(), 2328 Arg.getAsType(), 2329 Info, Deduced, 0); 2330 Info.FirstArg = Param; 2331 Info.SecondArg = Arg; 2332 return Sema::TDK_NonDeducedMismatch; 2333 2334 case TemplateArgument::Template: 2335 if (Arg.getKind() == TemplateArgument::Template) 2336 return DeduceTemplateArguments(S, TemplateParams, 2337 Param.getAsTemplate(), 2338 Arg.getAsTemplate(), Info, Deduced); 2339 Info.FirstArg = Param; 2340 Info.SecondArg = Arg; 2341 return Sema::TDK_NonDeducedMismatch; 2342 2343 case TemplateArgument::TemplateExpansion: 2344 llvm_unreachable("caller should handle pack expansions")::llvm::llvm_unreachable_internal("caller should handle pack expansions"
, "/build/llvm-toolchain-snapshot-14~++20211110111138+cffbfd01e37b/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 2344)
; 2345 2346 case TemplateArgument::Declaration: 2347 if (Arg.getKind() == TemplateArgument::Declaration && 2348 isSameDeclaration(Param.getAsDecl(), Arg.getAsDecl())) 2349 return Sema::TDK_Success; 2350 2351 Info.FirstArg = Param; 2352 Info.SecondArg = Arg; 2353 return Sema::TDK_NonDeducedMismatch; 2354 2355 case TemplateArgument::NullPtr: 2356 if (Arg.getKind() == TemplateArgument::NullPtr && 2357 S.Context.hasSameType(Param.getNullPtrType(), Arg.getNullPtrType())) 2358 return Sema::TDK_Success; 2359 2360 Info.FirstArg = Param; 2361 Info.SecondArg = Arg; 2362 return Sema::TDK_NonDeducedMismatch; 2363 2364 case TemplateArgument::Integral: 2365 if (Arg.getKind() == TemplateArgument::Integral) { 2366 if (hasSameExtendedValue(Param.getAsIntegral(), Arg.getAsIntegral())) 2367 return Sema::TDK_Success; 2368 2369 Info.FirstArg = Param; 2370 Info.SecondArg = Arg; 2371 return Sema::TDK_NonDeducedMismatch; 2372 } 2373 2374 if (Arg.getKind() == TemplateArgument::Expression) { 2375 Info.FirstArg = Param; 2376 Info.SecondArg = Arg; 2377 return Sema::TDK_NonDeducedMismatch; 2378 } 2379 2380 Info.FirstArg = Param; 2381 Info.SecondArg = Arg; 2382 return Sema::TDK_NonDeducedMismatch; 2383 2384 case TemplateArgument::Expression: 2385 if (const NonTypeTemplateParmDecl *NTTP = 2386 getDeducedParameterFromExpr(Info, Param.getAsExpr())) { 2387 if (Arg.getKind() == TemplateArgument::Integral) 2388 return DeduceNonTypeTemplateArgument(S, TemplateParams, NTTP, 2389 Arg.getAsIntegral(), 2390 Arg.getIntegralType(), 2391 /*ArrayBound=*/false, 2392 Info, Deduced); 2393 if (Arg.getKind() == TemplateArgument::NullPtr) 2394 return DeduceNullPtrTemplateArgument(S, TemplateParams, NTTP, 2395 Arg.getNullPtrType(), 2396 Info, Deduced); 2397 if (Arg.getKind() == TemplateArgument::Expression) 2398 return DeduceNonTypeTemplateArgument(S, TemplateParams, NTTP, 2399 Arg.getAsExpr(), Info, Deduced); 2400 if (Arg.getKind() == TemplateArgument::Declaration) 2401 return DeduceNonTypeTemplateArgument(S, TemplateParams, NTTP, 2402 Arg.getAsDecl(), 2403 Arg.getParamTypeForDecl(), 2404 Info, Deduced); 2405 2406 Info.FirstArg = Param; 2407 Info.SecondArg = Arg; 2408 return Sema::TDK_NonDeducedMismatch; 2409 } 2410 2411 // Can't deduce anything, but that's okay. 2412 return Sema::TDK_Success; 2413 2414 case TemplateArgument::Pack: 2415 llvm_unreachable("Argument packs should be expanded by the caller!")::llvm::llvm_unreachable_internal("Argument packs should be expanded by the caller!"
, "/build/llvm-toolchain-snapshot-14~++20211110111138+cffbfd01e37b/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 2415)
; 2416 } 2417 2418 llvm_unreachable("Invalid TemplateArgument Kind!")::llvm::llvm_unreachable_internal("Invalid TemplateArgument Kind!"
, "/build/llvm-toolchain-snapshot-14~++20211110111138+cffbfd01e37b/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 2418)
; 2419} 2420 2421/// Determine whether there is a template argument to be used for 2422/// deduction. 2423/// 2424/// This routine "expands" argument packs in-place, overriding its input 2425/// parameters so that \c Args[ArgIdx] will be the available template argument. 2426/// 2427/// \returns true if there is another template argument (which will be at 2428/// \c Args[ArgIdx]), false otherwise. 2429static bool hasTemplateArgumentForDeduction(ArrayRef<TemplateArgument> &Args, 2430 unsigned &ArgIdx) { 2431 if (ArgIdx == Args.size()) 2432 return false; 2433 2434 const TemplateArgument &Arg = Args[ArgIdx]; 2435 if (Arg.getKind() != TemplateArgument::Pack) 2436 return true; 2437 2438 assert(ArgIdx == Args.size() - 1 && "Pack not at the end of argument list?")(static_cast <bool> (ArgIdx == Args.size() - 1 &&
"Pack not at the end of argument list?") ? void (0) : __assert_fail
("ArgIdx == Args.size() - 1 && \"Pack not at the end of argument list?\""
, "/build/llvm-toolchain-snapshot-14~++20211110111138+cffbfd01e37b/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 2438, __extension__ __PRETTY_FUNCTION__))
; 2439 Args = Arg.pack_elements(); 2440 ArgIdx = 0; 2441 return ArgIdx < Args.size(); 2442} 2443 2444/// Determine whether the given set of template arguments has a pack 2445/// expansion that is not the last template argument. 2446static bool hasPackExpansionBeforeEnd(ArrayRef<TemplateArgument> Args) { 2447 bool FoundPackExpansion = false; 2448 for (const auto &A : Args) { 2449 if (FoundPackExpansion) 2450 return true; 2451 2452 if (A.getKind() == TemplateArgument::Pack) 2453 return hasPackExpansionBeforeEnd(A.pack_elements()); 2454 2455 // FIXME: If this is a fixed-arity pack expansion from an outer level of 2456 // templates, it should not be treated as a pack expansion. 2457 if (A.isPackExpansion()) 2458 FoundPackExpansion = true; 2459 } 2460 2461 return false; 2462} 2463 2464static Sema::TemplateDeductionResult 2465DeduceTemplateArguments(Sema &S, TemplateParameterList *TemplateParams, 2466 ArrayRef<TemplateArgument> Params, 2467 ArrayRef<TemplateArgument> Args, 2468 TemplateDeductionInfo &Info, 2469 SmallVectorImpl<DeducedTemplateArgument> &Deduced, 2470 bool NumberOfArgumentsMustMatch) { 2471 // C++0x [temp.deduct.type]p9: 2472 // If the template argument list of P contains a pack expansion that is not 2473 // the last template argument, the entire template argument list is a 2474 // non-deduced context. 2475 if (hasPackExpansionBeforeEnd(Params)) 2476 return Sema::TDK_Success; 2477 2478 // C++0x [temp.deduct.type]p9: 2479 // If P has a form that contains <T> or <i>, then each argument Pi of the 2480 // respective template argument list P is compared with the corresponding 2481 // argument Ai of the corresponding template argument list of A. 2482 unsigned ArgIdx = 0, ParamIdx = 0; 2483 for (; hasTemplateArgumentForDeduction(Params, ParamIdx); ++ParamIdx) { 2484 if (!Params[ParamIdx].isPackExpansion()) { 2485 // The simple case: deduce template arguments by matching Pi and Ai. 2486 2487 // Check whether we have enough arguments. 2488 if (!hasTemplateArgumentForDeduction(Args, ArgIdx)) 2489 return NumberOfArgumentsMustMatch 2490 ? Sema::TDK_MiscellaneousDeductionFailure 2491 : Sema::TDK_Success; 2492 2493 // C++1z [temp.deduct.type]p9: 2494 // During partial ordering, if Ai was originally a pack expansion [and] 2495 // Pi is not a pack expansion, template argument deduction fails. 2496 if (Args[ArgIdx].isPackExpansion()) 2497 return Sema::TDK_MiscellaneousDeductionFailure; 2498 2499 // Perform deduction for this Pi/Ai pair. 2500 if (Sema::TemplateDeductionResult Result 2501 = DeduceTemplateArguments(S, TemplateParams, 2502 Params[ParamIdx], Args[ArgIdx], 2503 Info, Deduced)) 2504 return Result; 2505 2506 // Move to the next argument. 2507 ++ArgIdx; 2508 continue; 2509 } 2510 2511 // The parameter is a pack expansion. 2512 2513 // C++0x [temp.deduct.type]p9: 2514 // If Pi is a pack expansion, then the pattern of Pi is compared with 2515 // each remaining argument in the template argument list of A. Each 2516 // comparison deduces template arguments for subsequent positions in the 2517 // template parameter packs expanded by Pi. 2518 TemplateArgument Pattern = Params[ParamIdx].getPackExpansionPattern(); 2519 2520 // Prepare to deduce the packs within the pattern. 2521 PackDeductionScope PackScope(S, TemplateParams, Deduced, Info, Pattern); 2522 2523 // Keep track of the deduced template arguments for each parameter pack 2524 // expanded by this pack expansion (the outer index) and for each 2525 // template argument (the inner SmallVectors). 2526 for (; hasTemplateArgumentForDeduction(Args, ArgIdx) && 2527 PackScope.hasNextElement(); 2528 ++ArgIdx) { 2529 // Deduce template arguments from the pattern. 2530 if (Sema::TemplateDeductionResult Result 2531 = DeduceTemplateArguments(S, TemplateParams, Pattern, Args[ArgIdx], 2532 Info, Deduced)) 2533 return Result; 2534 2535 PackScope.nextPackElement(); 2536 } 2537 2538 // Build argument packs for each of the parameter packs expanded by this 2539 // pack expansion. 2540 if (auto Result = PackScope.finish()) 2541 return Result; 2542 } 2543 2544 return Sema::TDK_Success; 2545} 2546 2547static Sema::TemplateDeductionResult 2548DeduceTemplateArguments(Sema &S, 2549 TemplateParameterList *TemplateParams, 2550 const TemplateArgumentList &ParamList, 2551 const TemplateArgumentList &ArgList, 2552 TemplateDeductionInfo &Info, 2553 SmallVectorImpl<DeducedTemplateArgument> &Deduced) { 2554 return DeduceTemplateArguments(S, TemplateParams, ParamList.asArray(), 2555 ArgList.asArray(), Info, Deduced, 2556 /*NumberOfArgumentsMustMatch*/false); 2557} 2558 2559/// Determine whether two template arguments are the same. 2560static bool isSameTemplateArg(ASTContext &Context, 2561 TemplateArgument X, 2562 const TemplateArgument &Y, 2563 bool PackExpansionMatchesPack = false) { 2564 // If we're checking deduced arguments (X) against original arguments (Y), 2565 // we will have flattened packs to non-expansions in X. 2566 if (PackExpansionMatchesPack && X.isPackExpansion() && !Y.isPackExpansion()) 2567 X = X.getPackExpansionPattern(); 2568 2569 if (X.getKind() != Y.getKind()) 2570 return false; 2571 2572 switch (X.getKind()) { 2573 case TemplateArgument::Null: 2574 llvm_unreachable("Comparing NULL template argument")::llvm::llvm_unreachable_internal("Comparing NULL template argument"
, "/build/llvm-toolchain-snapshot-14~++20211110111138+cffbfd01e37b/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 2574)
; 2575 2576 case TemplateArgument::Type: 2577 return Context.getCanonicalType(X.getAsType()) == 2578 Context.getCanonicalType(Y.getAsType()); 2579 2580 case TemplateArgument::Declaration: 2581 return isSameDeclaration(X.getAsDecl(), Y.getAsDecl()); 2582 2583 case TemplateArgument::NullPtr: 2584 return Context.hasSameType(X.getNullPtrType(), Y.getNullPtrType()); 2585 2586 case TemplateArgument::Template: 2587 case TemplateArgument::TemplateExpansion: 2588 return Context.getCanonicalTemplateName( 2589 X.getAsTemplateOrTemplatePattern()).getAsVoidPointer() == 2590 Context.getCanonicalTemplateName( 2591 Y.getAsTemplateOrTemplatePattern()).getAsVoidPointer(); 2592 2593 case TemplateArgument::Integral: 2594 return hasSameExtendedValue(X.getAsIntegral(), Y.getAsIntegral()); 2595 2596 case TemplateArgument::Expression: { 2597 llvm::FoldingSetNodeID XID, YID; 2598 X.getAsExpr()->Profile(XID, Context, true); 2599 Y.getAsExpr()->Profile(YID, Context, true); 2600 return XID == YID; 2601 } 2602 2603 case TemplateArgument::Pack: 2604 if (X.pack_size() != Y.pack_size()) 2605 return false; 2606 2607 for (TemplateArgument::pack_iterator XP = X.pack_begin(), 2608 XPEnd = X.pack_end(), 2609 YP = Y.pack_begin(); 2610 XP != XPEnd; ++XP, ++YP) 2611 if (!isSameTemplateArg(Context, *XP, *YP, PackExpansionMatchesPack)) 2612 return false; 2613 2614 return true; 2615 } 2616 2617 llvm_unreachable("Invalid TemplateArgument Kind!")::llvm::llvm_unreachable_internal("Invalid TemplateArgument Kind!"
, "/build/llvm-toolchain-snapshot-14~++20211110111138+cffbfd01e37b/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 2617)
; 2618} 2619 2620/// Allocate a TemplateArgumentLoc where all locations have 2621/// been initialized to the given location. 2622/// 2623/// \param Arg The template argument we are producing template argument 2624/// location information for. 2625/// 2626/// \param NTTPType For a declaration template argument, the type of 2627/// the non-type template parameter that corresponds to this template 2628/// argument. Can be null if no type sugar is available to add to the 2629/// type from the template argument. 2630/// 2631/// \param Loc The source location to use for the resulting template 2632/// argument. 2633TemplateArgumentLoc 2634Sema::getTrivialTemplateArgumentLoc(const TemplateArgument &Arg, 2635 QualType NTTPType, SourceLocation Loc) { 2636 switch (Arg.getKind()) { 2637 case TemplateArgument::Null: 2638 llvm_unreachable("Can't get a NULL template argument here")::llvm::llvm_unreachable_internal("Can't get a NULL template argument here"
, "/build/llvm-toolchain-snapshot-14~++20211110111138+cffbfd01e37b/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 2638)
; 2639 2640 case TemplateArgument::Type: 2641 return TemplateArgumentLoc( 2642 Arg, Context.getTrivialTypeSourceInfo(Arg.getAsType(), Loc)); 2643 2644 case TemplateArgument::Declaration: { 2645 if (NTTPType.isNull()) 2646 NTTPType = Arg.getParamTypeForDecl(); 2647 Expr *E = BuildExpressionFromDeclTemplateArgument(Arg, NTTPType, Loc) 2648 .getAs<Expr>(); 2649 return TemplateArgumentLoc(TemplateArgument(E), E); 2650 } 2651 2652 case TemplateArgument::NullPtr: { 2653 if (NTTPType.isNull()) 2654 NTTPType = Arg.getNullPtrType(); 2655 Expr *E = BuildExpressionFromDeclTemplateArgument(Arg, NTTPType, Loc) 2656 .getAs<Expr>(); 2657 return TemplateArgumentLoc(TemplateArgument(NTTPType, /*isNullPtr*/true), 2658 E); 2659 } 2660 2661 case TemplateArgument::Integral: { 2662 Expr *E = 2663 BuildExpressionFromIntegralTemplateArgument(Arg, Loc).getAs<Expr>(); 2664 return TemplateArgumentLoc(TemplateArgument(E), E); 2665 } 2666 2667 case TemplateArgument::Template: 2668 case TemplateArgument::TemplateExpansion: { 2669 NestedNameSpecifierLocBuilder Builder; 2670 TemplateName Template = Arg.getAsTemplateOrTemplatePattern(); 2671 if (DependentTemplateName *DTN = Template.getAsDependentTemplateName()) 2672 Builder.MakeTrivial(Context, DTN->getQualifier(), Loc); 2673 else if (QualifiedTemplateName *QTN = 2674 Template.getAsQualifiedTemplateName()) 2675 Builder.MakeTrivial(Context, QTN->getQualifier(), Loc); 2676 2677 if (Arg.getKind() == TemplateArgument::Template) 2678 return TemplateArgumentLoc(Context, Arg, 2679 Builder.getWithLocInContext(Context), Loc); 2680 2681 return TemplateArgumentLoc( 2682 Context, Arg, Builder.getWithLocInContext(Context), Loc, Loc); 2683 } 2684 2685 case TemplateArgument::Expression: 2686 return TemplateArgumentLoc(Arg, Arg.getAsExpr()); 2687 2688 case TemplateArgument::Pack: 2689 return TemplateArgumentLoc(Arg, TemplateArgumentLocInfo()); 2690 } 2691 2692 llvm_unreachable("Invalid TemplateArgument Kind!")::llvm::llvm_unreachable_internal("Invalid TemplateArgument Kind!"
, "/build/llvm-toolchain-snapshot-14~++20211110111138+cffbfd01e37b/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 2692)
; 2693} 2694 2695TemplateArgumentLoc 2696Sema::getIdentityTemplateArgumentLoc(NamedDecl *TemplateParm, 2697 SourceLocation Location) { 2698 return getTrivialTemplateArgumentLoc( 2699 Context.getInjectedTemplateArg(TemplateParm), QualType(), Location); 2700} 2701 2702/// Convert the given deduced template argument and add it to the set of 2703/// fully-converted template arguments. 2704static bool 2705ConvertDeducedTemplateArgument(Sema &S, NamedDecl *Param, 2706 DeducedTemplateArgument Arg, 2707 NamedDecl *Template, 2708 TemplateDeductionInfo &Info, 2709 bool IsDeduced, 2710 SmallVectorImpl<TemplateArgument> &Output) { 2711 auto ConvertArg = [&](DeducedTemplateArgument Arg, 2712 unsigned ArgumentPackIndex) { 2713 // Convert the deduced template argument into a template 2714 // argument that we can check, almost as if the user had written 2715 // the template argument explicitly. 2716 TemplateArgumentLoc ArgLoc = 2717 S.getTrivialTemplateArgumentLoc(Arg, QualType(), Info.getLocation()); 2718 2719 // Check the template argument, converting it as necessary. 2720 return S.CheckTemplateArgument( 2721 Param, ArgLoc, Template, Template->getLocation(), 2722 Template->getSourceRange().getEnd(), ArgumentPackIndex, Output, 2723 IsDeduced 2724 ? (Arg.wasDeducedFromArrayBound() ? Sema::CTAK_DeducedFromArrayBound 2725 : Sema::CTAK_Deduced) 2726 : Sema::CTAK_Specified); 2727 }; 2728 2729 if (Arg.getKind() == TemplateArgument::Pack) { 2730 // This is a template argument pack, so check each of its arguments against 2731 // the template parameter. 2732 SmallVector<TemplateArgument, 2> PackedArgsBuilder; 2733 for (const auto &P : Arg.pack_elements()) { 2734 // When converting the deduced template argument, append it to the 2735 // general output list. We need to do this so that the template argument 2736 // checking logic has all of the prior template arguments available. 2737 DeducedTemplateArgument InnerArg(P); 2738 InnerArg.setDeducedFromArrayBound(Arg.wasDeducedFromArrayBound()); 2739 assert(InnerArg.getKind() != TemplateArgument::Pack &&(static_cast <bool> (InnerArg.getKind() != TemplateArgument
::Pack && "deduced nested pack") ? void (0) : __assert_fail
("InnerArg.getKind() != TemplateArgument::Pack && \"deduced nested pack\""
, "/build/llvm-toolchain-snapshot-14~++20211110111138+cffbfd01e37b/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 2740, __extension__ __PRETTY_FUNCTION__))
2740 "deduced nested pack")(static_cast <bool> (InnerArg.getKind() != TemplateArgument
::Pack && "deduced nested pack") ? void (0) : __assert_fail
("InnerArg.getKind() != TemplateArgument::Pack && \"deduced nested pack\""
, "/build/llvm-toolchain-snapshot-14~++20211110111138+cffbfd01e37b/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 2740, __extension__ __PRETTY_FUNCTION__))
; 2741 if (P.isNull()) { 2742 // We deduced arguments for some elements of this pack, but not for 2743 // all of them. This happens if we get a conditionally-non-deduced 2744 // context in a pack expansion (such as an overload set in one of the 2745 // arguments). 2746 S.Diag(Param->getLocation(), 2747 diag::err_template_arg_deduced_incomplete_pack) 2748 << Arg << Param; 2749 return true; 2750 } 2751 if (ConvertArg(InnerArg, PackedArgsBuilder.size())) 2752 return true; 2753 2754 // Move the converted template argument into our argument pack. 2755 PackedArgsBuilder.push_back(Output.pop_back_val()); 2756 } 2757 2758 // If the pack is empty, we still need to substitute into the parameter 2759 // itself, in case that substitution fails. 2760 if (PackedArgsBuilder.empty()) { 2761 LocalInstantiationScope Scope(S); 2762 TemplateArgumentList TemplateArgs(TemplateArgumentList::OnStack, Output); 2763 MultiLevelTemplateArgumentList Args(TemplateArgs); 2764 2765 if (auto *NTTP = dyn_cast<NonTypeTemplateParmDecl>(Param)) { 2766 Sema::InstantiatingTemplate Inst(S, Template->getLocation(), Template, 2767 NTTP, Output, 2768 Template->getSourceRange()); 2769 if (Inst.isInvalid() || 2770 S.SubstType(NTTP->getType(), Args, NTTP->getLocation(), 2771 NTTP->getDeclName()).isNull()) 2772 return true; 2773 } else if (auto *TTP = dyn_cast<TemplateTemplateParmDecl>(Param)) { 2774 Sema::InstantiatingTemplate Inst(S, Template->getLocation(), Template, 2775 TTP, Output, 2776 Template->getSourceRange()); 2777 if (Inst.isInvalid() || !S.SubstDecl(TTP, S.CurContext, Args)) 2778 return true; 2779 } 2780 // For type parameters, no substitution is ever required. 2781 } 2782 2783 // Create the resulting argument pack. 2784 Output.push_back( 2785 TemplateArgument::CreatePackCopy(S.Context, PackedArgsBuilder)); 2786 return false; 2787 } 2788 2789 return ConvertArg(Arg, 0); 2790} 2791 2792// FIXME: This should not be a template, but 2793// ClassTemplatePartialSpecializationDecl sadly does not derive from 2794// TemplateDecl. 2795template<typename TemplateDeclT> 2796static Sema::TemplateDeductionResult ConvertDeducedTemplateArguments( 2797 Sema &S, TemplateDeclT *Template, bool IsDeduced, 2798 SmallVectorImpl<DeducedTemplateArgument> &Deduced, 2799 TemplateDeductionInfo &Info, SmallVectorImpl<TemplateArgument> &Builder, 2800 LocalInstantiationScope *CurrentInstantiationScope = nullptr, 2801 unsigned NumAlreadyConverted = 0, bool PartialOverloading = false) { 2802 TemplateParameterList *TemplateParams = Template->getTemplateParameters(); 2803 2804 for (unsigned I = 0, N = TemplateParams->size(); I != N; ++I) { 2805 NamedDecl *Param = TemplateParams->getParam(I); 2806 2807 // C++0x [temp.arg.explicit]p3: 2808 // A trailing template parameter pack (14.5.3) not otherwise deduced will 2809 // be deduced to an empty sequence of template arguments. 2810 // FIXME: Where did the word "trailing" come from? 2811 if (Deduced[I].isNull() && Param->isTemplateParameterPack()) { 2812 if (auto Result = 2813 PackDeductionScope(S, TemplateParams, Deduced, Info, I).finish()) 2814 return Result; 2815 } 2816 2817 if (!Deduced[I].isNull()) { 2818 if (I < NumAlreadyConverted) { 2819 // We may have had explicitly-specified template arguments for a 2820 // template parameter pack (that may or may not have been extended 2821 // via additional deduced arguments). 2822 if (Param->isParameterPack() && CurrentInstantiationScope && 2823 CurrentInstantiationScope->getPartiallySubstitutedPack() == Param) { 2824 // Forget the partially-substituted pack; its substitution is now 2825 // complete. 2826 CurrentInstantiationScope->ResetPartiallySubstitutedPack(); 2827 // We still need to check the argument in case it was extended by 2828 // deduction. 2829 } else { 2830 // We have already fully type-checked and converted this 2831 // argument, because it was explicitly-specified. Just record the 2832 // presence of this argument. 2833 Builder.push_back(Deduced[I]); 2834 continue; 2835 } 2836 } 2837 2838 // We may have deduced this argument, so it still needs to be 2839 // checked and converted. 2840 if (ConvertDeducedTemplateArgument(S, Param, Deduced[I], Template, Info, 2841 IsDeduced, Builder)) { 2842 Info.Param = makeTemplateParameter(Param); 2843 // FIXME: These template arguments are temporary. Free them! 2844 Info.reset(TemplateArgumentList::CreateCopy(S.Context, Builder)); 2845 return Sema::TDK_SubstitutionFailure; 2846 } 2847 2848 continue; 2849 } 2850 2851 // Substitute into the default template argument, if available. 2852 bool HasDefaultArg = false; 2853 TemplateDecl *TD = dyn_cast<TemplateDecl>(Template); 2854 if (!TD) { 2855 assert(isa<ClassTemplatePartialSpecializationDecl>(Template) ||(static_cast <bool> (isa<ClassTemplatePartialSpecializationDecl
>(Template) || isa<VarTemplatePartialSpecializationDecl
>(Template)) ? void (0) : __assert_fail ("isa<ClassTemplatePartialSpecializationDecl>(Template) || isa<VarTemplatePartialSpecializationDecl>(Template)"
, "/build/llvm-toolchain-snapshot-14~++20211110111138+cffbfd01e37b/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 2856, __extension__ __PRETTY_FUNCTION__))
2856 isa<VarTemplatePartialSpecializationDecl>(Template))(static_cast <bool> (isa<ClassTemplatePartialSpecializationDecl
>(Template) || isa<VarTemplatePartialSpecializationDecl
>(Template)) ? void (0) : __assert_fail ("isa<ClassTemplatePartialSpecializationDecl>(Template) || isa<VarTemplatePartialSpecializationDecl>(Template)"
, "/build/llvm-toolchain-snapshot-14~++20211110111138+cffbfd01e37b/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 2856, __extension__ __PRETTY_FUNCTION__))
; 2857 return Sema::TDK_Incomplete; 2858 } 2859 2860 TemplateArgumentLoc DefArg; 2861 { 2862 Qualifiers ThisTypeQuals; 2863 CXXRecordDecl *ThisContext = nullptr; 2864 if (auto *Rec = dyn_cast<CXXRecordDecl>(TD->getDeclContext())) 2865 if (Rec->isLambda()) 2866 if (auto *Method = dyn_cast<CXXMethodDecl>(Rec->getDeclContext())) { 2867 ThisContext = Method->getParent(); 2868 ThisTypeQuals = Method->getMethodQualifiers(); 2869 } 2870 2871 Sema::CXXThisScopeRAII ThisScope(S, ThisContext, ThisTypeQuals, 2872 S.getLangOpts().CPlusPlus17); 2873 2874 DefArg = S.SubstDefaultTemplateArgumentIfAvailable( 2875 TD, TD->getLocation(), TD->getSourceRange().getEnd(), Param, Builder, 2876 HasDefaultArg); 2877 } 2878 2879 // If there was no default argument, deduction is incomplete. 2880 if (DefArg.getArgument().isNull()) { 2881 Info.Param = makeTemplateParameter( 2882 const_cast<NamedDecl *>(TemplateParams->getParam(I))); 2883 Info.reset(TemplateArgumentList::CreateCopy(S.Context, Builder)); 2884 if (PartialOverloading) break; 2885 2886 return HasDefaultArg ? Sema::TDK_SubstitutionFailure 2887 : Sema::TDK_Incomplete; 2888 } 2889 2890 // Check whether we can actually use the default argument. 2891 if (S.CheckTemplateArgument(Param, DefArg, TD, TD->getLocation(), 2892 TD->getSourceRange().getEnd(), 0, Builder, 2893 Sema::CTAK_Specified)) { 2894 Info.Param = makeTemplateParameter( 2895 const_cast<NamedDecl *>(TemplateParams->getParam(I))); 2896 // FIXME: These template arguments are temporary. Free them! 2897 Info.reset(TemplateArgumentList::CreateCopy(S.Context, Builder)); 2898 return Sema::TDK_SubstitutionFailure; 2899 } 2900 2901 // If we get here, we successfully used the default template argument. 2902 } 2903 2904 return Sema::TDK_Success; 2905} 2906 2907static DeclContext *getAsDeclContextOrEnclosing(Decl *D) { 2908 if (auto *DC = dyn_cast<DeclContext>(D)) 2909 return DC; 2910 return D->getDeclContext(); 2911} 2912 2913template<typename T> struct IsPartialSpecialization { 2914 static constexpr bool value = false; 2915}; 2916template<> 2917struct IsPartialSpecialization<ClassTemplatePartialSpecializationDecl> { 2918 static constexpr bool value = true; 2919}; 2920template<> 2921struct IsPartialSpecialization<VarTemplatePartialSpecializationDecl> { 2922 static constexpr bool value = true; 2923}; 2924 2925template<typename TemplateDeclT> 2926static Sema::TemplateDeductionResult 2927CheckDeducedArgumentConstraints(Sema& S, TemplateDeclT *Template, 2928 ArrayRef<TemplateArgument> DeducedArgs, 2929 TemplateDeductionInfo& Info) { 2930 llvm::SmallVector<const Expr *, 3> AssociatedConstraints; 2931 Template->getAssociatedConstraints(AssociatedConstraints); 2932 if (S.CheckConstraintSatisfaction(Template, AssociatedConstraints, 2933 DeducedArgs, Info.getLocation(), 2934 Info.AssociatedConstraintsSatisfaction) || 2935 !Info.AssociatedConstraintsSatisfaction.IsSatisfied) { 2936 Info.reset(TemplateArgumentList::CreateCopy(S.Context, DeducedArgs)); 2937 return Sema::TDK_ConstraintsNotSatisfied; 2938 } 2939 return Sema::TDK_Success; 2940} 2941 2942/// Complete template argument deduction for a partial specialization. 2943template <typename T> 2944static std::enable_if_t<IsPartialSpecialization<T>::value, 2945 Sema::TemplateDeductionResult> 2946FinishTemplateArgumentDeduction( 2947 Sema &S, T *Partial, bool IsPartialOrdering, 2948 const TemplateArgumentList &TemplateArgs, 2949 SmallVectorImpl<DeducedTemplateArgument> &Deduced, 2950 TemplateDeductionInfo &Info) { 2951 // Unevaluated SFINAE context. 2952 EnterExpressionEvaluationContext Unevaluated( 2953 S, Sema::ExpressionEvaluationContext::Unevaluated); 2954 Sema::SFINAETrap Trap(S); 2955 2956 Sema::ContextRAII SavedContext(S, getAsDeclContextOrEnclosing(Partial)); 2957 2958 // C++ [temp.deduct.type]p2: 2959 // [...] or if any template argument remains neither deduced nor 2960 // explicitly specified, template argument deduction fails. 2961 SmallVector<TemplateArgument, 4> Builder; 2962 if (auto Result = ConvertDeducedTemplateArguments( 2963 S, Partial, IsPartialOrdering, Deduced, Info, Builder)) 2964 return Result; 2965 2966 // Form the template argument list from the deduced template arguments. 2967 TemplateArgumentList *DeducedArgumentList 2968 = TemplateArgumentList::CreateCopy(S.Context, Builder); 2969 2970 Info.reset(DeducedArgumentList); 2971 2972 // Substitute the deduced template arguments into the template 2973 // arguments of the class template partial specialization, and 2974 // verify that the instantiated template arguments are both valid 2975 // and are equivalent to the template arguments originally provided 2976 // to the class template. 2977 LocalInstantiationScope InstScope(S); 2978 auto *Template = Partial->getSpecializedTemplate(); 2979 const ASTTemplateArgumentListInfo *PartialTemplArgInfo = 2980 Partial->getTemplateArgsAsWritten(); 2981 2982 TemplateArgumentListInfo InstArgs(PartialTemplArgInfo->LAngleLoc, 2983 PartialTemplArgInfo->RAngleLoc); 2984 2985 if (S.SubstTemplateArguments( 2986 PartialTemplArgInfo->arguments(), 2987 MultiLevelTemplateArgumentList(*DeducedArgumentList), InstArgs)) { 2988 unsigned ArgIdx = InstArgs.size(), ParamIdx = ArgIdx; 2989 if (ParamIdx >= Partial->getTemplateParameters()->size()) 2990 ParamIdx = Partial->getTemplateParameters()->size() - 1; 2991 2992 Decl *Param = const_cast<NamedDecl *>( 2993 Partial->getTemplateParameters()->getParam(ParamIdx)); 2994 Info.Param = makeTemplateParameter(Param); 2995 Info.FirstArg = (*PartialTemplArgInfo)[ArgIdx].getArgument(); 2996 return Sema::TDK_SubstitutionFailure; 2997 } 2998 2999 bool ConstraintsNotSatisfied; 3000 SmallVector<TemplateArgument, 4> ConvertedInstArgs; 3001 if (S.CheckTemplateArgumentList(Template, Partial->getLocation(), InstArgs, 3002 false, ConvertedInstArgs, 3003 /*UpdateArgsWithConversions=*/true, 3004 &ConstraintsNotSatisfied)) 3005 return ConstraintsNotSatisfied ? Sema::TDK_ConstraintsNotSatisfied : 3006 Sema::TDK_SubstitutionFailure; 3007 3008 TemplateParameterList *TemplateParams = Template->getTemplateParameters(); 3009 for (unsigned I = 0, E = TemplateParams->size(); I != E; ++I) { 3010 TemplateArgument InstArg = ConvertedInstArgs.data()[I]; 3011 if (!isSameTemplateArg(S.Context, TemplateArgs[I], InstArg)) { 3012 Info.Param = makeTemplateParameter(TemplateParams->getParam(I)); 3013 Info.FirstArg = TemplateArgs[I]; 3014 Info.SecondArg = InstArg; 3015 return Sema::TDK_NonDeducedMismatch; 3016 } 3017 } 3018 3019 if (Trap.hasErrorOccurred()) 3020 return Sema::TDK_SubstitutionFailure; 3021 3022 if (auto Result = CheckDeducedArgumentConstraints(S, Partial, Builder, Info)) 3023 return Result; 3024 3025 return Sema::TDK_Success; 3026} 3027 3028/// Complete template argument deduction for a class or variable template, 3029/// when partial ordering against a partial specialization. 3030// FIXME: Factor out duplication with partial specialization version above. 3031static Sema::TemplateDeductionResult FinishTemplateArgumentDeduction( 3032 Sema &S, TemplateDecl *Template, bool PartialOrdering, 3033 const TemplateArgumentList &TemplateArgs, 3034 SmallVectorImpl<DeducedTemplateArgument> &Deduced, 3035 TemplateDeductionInfo &Info) { 3036 // Unevaluated SFINAE context. 3037 EnterExpressionEvaluationContext Unevaluated( 3038 S, Sema::ExpressionEvaluationContext::Unevaluated); 3039 Sema::SFINAETrap Trap(S); 3040 3041 Sema::ContextRAII SavedContext(S, getAsDeclContextOrEnclosing(Template)); 3042 3043 // C++ [temp.deduct.type]p2: 3044 // [...] or if any template argument remains neither deduced nor 3045 // explicitly specified, template argument deduction fails. 3046 SmallVector<TemplateArgument, 4> Builder; 3047 if (auto Result = ConvertDeducedTemplateArguments( 3048 S, Template, /*IsDeduced*/PartialOrdering, Deduced, Info, Builder)) 3049 return Result; 3050 3051 // Check that we produced the correct argument list. 3052 TemplateParameterList *TemplateParams = Template->getTemplateParameters(); 3053 for (unsigned I = 0, E = TemplateParams->size(); I != E; ++I) { 3054 TemplateArgument InstArg = Builder[I]; 3055 if (!isSameTemplateArg(S.Context, TemplateArgs[I], InstArg, 3056 /*PackExpansionMatchesPack*/true)) { 3057 Info.Param = makeTemplateParameter(TemplateParams->getParam(I)); 3058 Info.FirstArg = TemplateArgs[I]; 3059 Info.SecondArg = InstArg; 3060 return Sema::TDK_NonDeducedMismatch; 3061 } 3062 } 3063 3064 if (Trap.hasErrorOccurred()) 3065 return Sema::TDK_SubstitutionFailure; 3066 3067 if (auto Result = CheckDeducedArgumentConstraints(S, Template, Builder, 3068 Info)) 3069 return Result; 3070 3071 return Sema::TDK_Success; 3072} 3073 3074/// Perform template argument deduction to determine whether 3075/// the given template arguments match the given class template 3076/// partial specialization per C++ [temp.class.spec.match]. 3077Sema::TemplateDeductionResult 3078Sema::DeduceTemplateArguments(ClassTemplatePartialSpecializationDecl *Partial, 3079 const TemplateArgumentList &TemplateArgs, 3080 TemplateDeductionInfo &Info) { 3081 if (Partial->isInvalidDecl()) 3082 return TDK_Invalid; 3083 3084 // C++ [temp.class.spec.match]p2: 3085 // A partial specialization matches a given actual template 3086 // argument list if the template arguments of the partial 3087 // specialization can be deduced from the actual template argument 3088 // list (14.8.2). 3089 3090 // Unevaluated SFINAE context. 3091 EnterExpressionEvaluationContext Unevaluated( 3092 *this, Sema::ExpressionEvaluationContext::Unevaluated); 3093 SFINAETrap Trap(*this); 3094 3095 // This deduction has no relation to any outer instantiation we might be 3096 // performing. 3097 LocalInstantiationScope InstantiationScope(*this); 3098 3099 SmallVector<DeducedTemplateArgument, 4> Deduced; 3100 Deduced.resize(Partial->getTemplateParameters()->size()); 3101 if (TemplateDeductionResult Result 3102 = ::DeduceTemplateArguments(*this, 3103 Partial->getTemplateParameters(), 3104 Partial->getTemplateArgs(), 3105 TemplateArgs, Info, Deduced)) 3106 return Result; 3107 3108 SmallVector<TemplateArgument, 4> DeducedArgs(Deduced.begin(), Deduced.end()); 3109 InstantiatingTemplate Inst(*this, Info.getLocation(), Partial, DeducedArgs, 3110 Info); 3111 if (Inst.isInvalid()) 3112 return TDK_InstantiationDepth; 3113 3114 if (Trap.hasErrorOccurred()) 3115 return Sema::TDK_SubstitutionFailure; 3116 3117 TemplateDeductionResult Result; 3118 runWithSufficientStackSpace(Info.getLocation(), [&] { 3119 Result = ::FinishTemplateArgumentDeduction(*this, Partial, 3120 /*IsPartialOrdering=*/false, 3121 TemplateArgs, Deduced, Info); 3122 }); 3123 return Result; 3124} 3125 3126/// Perform template argument deduction to determine whether 3127/// the given template arguments match the given variable template 3128/// partial specialization per C++ [temp.class.spec.match]. 3129Sema::TemplateDeductionResult 3130Sema::DeduceTemplateArguments(VarTemplatePartialSpecializationDecl *Partial, 3131 const TemplateArgumentList &TemplateArgs, 3132 TemplateDeductionInfo &Info) { 3133 if (Partial->isInvalidDecl()) 3134 return TDK_Invalid; 3135 3136 // C++ [temp.class.spec.match]p2: 3137 // A partial specialization matches a given actual template 3138 // argument list if the template arguments of the partial 3139 // specialization can be deduced from the actual template argument 3140 // list (14.8.2). 3141 3142 // Unevaluated SFINAE context. 3143 EnterExpressionEvaluationContext Unevaluated( 3144 *this, Sema::ExpressionEvaluationContext::Unevaluated); 3145 SFINAETrap Trap(*this); 3146 3147 // This deduction has no relation to any outer instantiation we might be 3148 // performing. 3149 LocalInstantiationScope InstantiationScope(*this); 3150 3151 SmallVector<DeducedTemplateArgument, 4> Deduced; 3152 Deduced.resize(Partial->getTemplateParameters()->size()); 3153 if (TemplateDeductionResult Result = ::DeduceTemplateArguments( 3154 *this, Partial->getTemplateParameters(), Partial->getTemplateArgs(), 3155 TemplateArgs, Info, Deduced)) 3156 return Result; 3157 3158 SmallVector<TemplateArgument, 4> DeducedArgs(Deduced.begin(), Deduced.end()); 3159 InstantiatingTemplate Inst(*this, Info.getLocation(), Partial, DeducedArgs, 3160 Info); 3161 if (Inst.isInvalid()) 3162 return TDK_InstantiationDepth; 3163 3164 if (Trap.hasErrorOccurred()) 3165 return Sema::TDK_SubstitutionFailure; 3166 3167 TemplateDeductionResult Result; 3168 runWithSufficientStackSpace(Info.getLocation(), [&] { 3169 Result = ::FinishTemplateArgumentDeduction(*this, Partial, 3170 /*IsPartialOrdering=*/false, 3171 TemplateArgs, Deduced, Info); 3172 }); 3173 return Result; 3174} 3175 3176/// Determine whether the given type T is a simple-template-id type. 3177static bool isSimpleTemplateIdType(QualType T) { 3178 if (const TemplateSpecializationType *Spec 3179 = T->getAs<TemplateSpecializationType>()) 3180 return Spec->getTemplateName().getAsTemplateDecl() != nullptr; 3181 3182 // C++17 [temp.local]p2: 3183 // the injected-class-name [...] is equivalent to the template-name followed 3184 // by the template-arguments of the class template specialization or partial 3185 // specialization enclosed in <> 3186 // ... which means it's equivalent to a simple-template-id. 3187 // 3188 // This only arises during class template argument deduction for a copy 3189 // deduction candidate, where it permits slicing. 3190 if (T->getAs<InjectedClassNameType>()) 3191 return true; 3192 3193 return false; 3194} 3195 3196/// Substitute the explicitly-provided template arguments into the 3197/// given function template according to C++ [temp.arg.explicit]. 3198/// 3199/// \param FunctionTemplate the function template into which the explicit 3200/// template arguments will be substituted. 3201/// 3202/// \param ExplicitTemplateArgs the explicitly-specified template 3203/// arguments. 3204/// 3205/// \param Deduced the deduced template arguments, which will be populated 3206/// with the converted and checked explicit template arguments. 3207/// 3208/// \param ParamTypes will be populated with the instantiated function 3209/// parameters. 3210/// 3211/// \param FunctionType if non-NULL, the result type of the function template 3212/// will also be instantiated and the pointed-to value will be updated with 3213/// the instantiated function type. 3214/// 3215/// \param Info if substitution fails for any reason, this object will be 3216/// populated with more information about the failure. 3217/// 3218/// \returns TDK_Success if substitution was successful, or some failure 3219/// condition. 3220Sema::TemplateDeductionResult 3221Sema::SubstituteExplicitTemplateArguments( 3222 FunctionTemplateDecl *FunctionTemplate, 3223 TemplateArgumentListInfo &ExplicitTemplateArgs, 3224 SmallVectorImpl<DeducedTemplateArgument> &Deduced, 3225 SmallVectorImpl<QualType> &ParamTypes, 3226 QualType *FunctionType, 3227 TemplateDeductionInfo &Info) { 3228 FunctionDecl *Function = FunctionTemplate->getTemplatedDecl(); 3229 TemplateParameterList *TemplateParams 3230 = FunctionTemplate->getTemplateParameters(); 3231 3232 if (ExplicitTemplateArgs.size() == 0) { 3233 // No arguments to substitute; just copy over the parameter types and 3234 // fill in the function type. 3235 for (auto P : Function->parameters()) 3236 ParamTypes.push_back(P->getType()); 3237 3238 if (FunctionType) 3239 *FunctionType = Function->getType(); 3240 return TDK_Success; 3241 } 3242 3243 // Unevaluated SFINAE context. 3244 EnterExpressionEvaluationContext Unevaluated( 3245 *this, Sema::ExpressionEvaluationContext::Unevaluated); 3246 SFINAETrap Trap(*this); 3247 3248 // C++ [temp.arg.explicit]p3: 3249 // Template arguments that are present shall be specified in the 3250 // declaration order of their corresponding template-parameters. The 3251 // template argument list shall not specify more template-arguments than 3252 // there are corresponding template-parameters. 3253 SmallVector<TemplateArgument, 4> Builder; 3254 3255 // Enter a new template instantiation context where we check the 3256 // explicitly-specified template arguments against this function template, 3257 // and then substitute them into the function parameter types. 3258 SmallVector<TemplateArgument, 4> DeducedArgs; 3259 InstantiatingTemplate Inst( 3260 *this, Info.getLocation(), FunctionTemplate, DeducedArgs, 3261 CodeSynthesisContext::ExplicitTemplateArgumentSubstitution, Info); 3262 if (Inst.isInvalid()) 3263 return TDK_InstantiationDepth; 3264 3265 if (CheckTemplateArgumentList(FunctionTemplate, SourceLocation(), 3266 ExplicitTemplateArgs, true, Builder, false) || 3267 Trap.hasErrorOccurred()) { 3268 unsigned Index = Builder.size(); 3269 if (Index >= TemplateParams->size()) 3270 return TDK_SubstitutionFailure; 3271 Info.Param = makeTemplateParameter(TemplateParams->getParam(Index)); 3272 return TDK_InvalidExplicitArguments; 3273 } 3274 3275 // Form the template argument list from the explicitly-specified 3276 // template arguments. 3277 TemplateArgumentList *ExplicitArgumentList 3278 = TemplateArgumentList::CreateCopy(Context, Builder); 3279 Info.setExplicitArgs(ExplicitArgumentList); 3280 3281 // Template argument deduction and the final substitution should be 3282 // done in the context of the templated declaration. Explicit 3283 // argument substitution, on the other hand, needs to happen in the 3284 // calling context. 3285 ContextRAII SavedContext(*this, FunctionTemplate->getTemplatedDecl()); 3286 3287 // If we deduced template arguments for a template parameter pack, 3288 // note that the template argument pack is partially substituted and record 3289 // the explicit template arguments. They'll be used as part of deduction 3290 // for this template parameter pack. 3291 unsigned PartiallySubstitutedPackIndex = -1u; 3292 if (!Builder.empty()) { 3293 const TemplateArgument &Arg = Builder.back(); 3294 if (Arg.getKind() == TemplateArgument::Pack) { 3295 auto *Param = TemplateParams->getParam(Builder.size() - 1); 3296 // If this is a fully-saturated fixed-size pack, it should be 3297 // fully-substituted, not partially-substituted. 3298 Optional<unsigned> Expansions = getExpandedPackSize(Param); 3299 if (!Expansions || Arg.pack_size() < *Expansions) { 3300 PartiallySubstitutedPackIndex = Builder.size() - 1; 3301 CurrentInstantiationScope->SetPartiallySubstitutedPack( 3302 Param, Arg.pack_begin(), Arg.pack_size()); 3303 } 3304 } 3305 } 3306 3307 const FunctionProtoType *Proto 3308 = Function->getType()->getAs<FunctionProtoType>(); 3309 assert(Proto && "Function template does not have a prototype?")(static_cast <bool> (Proto && "Function template does not have a prototype?"
) ? void (0) : __assert_fail ("Proto && \"Function template does not have a prototype?\""
, "/build/llvm-toolchain-snapshot-14~++20211110111138+cffbfd01e37b/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 3309, __extension__ __PRETTY_FUNCTION__))
; 3310 3311 // Isolate our substituted parameters from our caller. 3312 LocalInstantiationScope InstScope(*this, /*MergeWithOuterScope*/true); 3313 3314 ExtParameterInfoBuilder ExtParamInfos; 3315 3316 // Instantiate the types of each of the function parameters given the 3317 // explicitly-specified template arguments. If the function has a trailing 3318 // return type, substitute it after the arguments to ensure we substitute 3319 // in lexical order. 3320 if (Proto->hasTrailingReturn()) { 3321 if (SubstParmTypes(Function->getLocation(), Function->parameters(), 3322 Proto->getExtParameterInfosOrNull(), 3323 MultiLevelTemplateArgumentList(*ExplicitArgumentList), 3324 ParamTypes, /*params*/ nullptr, ExtParamInfos)) 3325 return TDK_SubstitutionFailure; 3326 } 3327 3328 // Instantiate the return type. 3329 QualType ResultType; 3330 { 3331 // C++11 [expr.prim.general]p3: 3332 // If a declaration declares a member function or member function 3333 // template of a class X, the expression this is a prvalue of type 3334 // "pointer to cv-qualifier-seq X" between the optional cv-qualifer-seq 3335 // and the end of the function-definition, member-declarator, or 3336 // declarator. 3337 Qualifiers ThisTypeQuals; 3338 CXXRecordDecl *ThisContext = nullptr; 3339 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Function)) { 3340 ThisContext = Method->getParent(); 3341 ThisTypeQuals = Method->getMethodQualifiers(); 3342 } 3343 3344 CXXThisScopeRAII ThisScope(*this, ThisContext, ThisTypeQuals, 3345 getLangOpts().CPlusPlus11); 3346 3347 ResultType = 3348 SubstType(Proto->getReturnType(), 3349 MultiLevelTemplateArgumentList(*ExplicitArgumentList), 3350 Function->getTypeSpecStartLoc(), Function->getDeclName()); 3351 if (ResultType.isNull() || Trap.hasErrorOccurred()) 3352 return TDK_SubstitutionFailure; 3353 // CUDA: Kernel function must have 'void' return type. 3354 if (getLangOpts().CUDA) 3355 if (Function->hasAttr<CUDAGlobalAttr>() && !ResultType->isVoidType()) { 3356 Diag(Function->getLocation(), diag::err_kern_type_not_void_return) 3357 << Function->getType() << Function->getSourceRange(); 3358 return TDK_SubstitutionFailure; 3359 } 3360 } 3361 3362 // Instantiate the types of each of the function parameters given the 3363 // explicitly-specified template arguments if we didn't do so earlier. 3364 if (!Proto->hasTrailingReturn() && 3365 SubstParmTypes(Function->getLocation(), Function->parameters(), 3366 Proto->getExtParameterInfosOrNull(), 3367 MultiLevelTemplateArgumentList(*ExplicitArgumentList), 3368 ParamTypes, /*params*/ nullptr, ExtParamInfos)) 3369 return TDK_SubstitutionFailure; 3370 3371 if (FunctionType) { 3372 auto EPI = Proto->getExtProtoInfo(); 3373 EPI.ExtParameterInfos = ExtParamInfos.getPointerOrNull(ParamTypes.size()); 3374 3375 // In C++1z onwards, exception specifications are part of the function type, 3376 // so substitution into the type must also substitute into the exception 3377 // specification. 3378 SmallVector<QualType, 4> ExceptionStorage; 3379 if (getLangOpts().CPlusPlus17 && 3380 SubstExceptionSpec( 3381 Function->getLocation(), EPI.ExceptionSpec, ExceptionStorage, 3382 MultiLevelTemplateArgumentList(*ExplicitArgumentList))) 3383 return TDK_SubstitutionFailure; 3384 3385 *FunctionType = BuildFunctionType(ResultType, ParamTypes, 3386 Function->getLocation(), 3387 Function->getDeclName(), 3388 EPI); 3389 if (FunctionType->isNull() || Trap.hasErrorOccurred()) 3390 return TDK_SubstitutionFailure; 3391 } 3392 3393 // C++ [temp.arg.explicit]p2: 3394 // Trailing template arguments that can be deduced (14.8.2) may be 3395 // omitted from the list of explicit template-arguments. If all of the 3396 // template arguments can be deduced, they may all be omitted; in this 3397 // case, the empty template argument list <> itself may also be omitted. 3398 // 3399 // Take all of the explicitly-specified arguments and put them into 3400 // the set of deduced template arguments. The partially-substituted 3401 // parameter pack, however, will be set to NULL since the deduction 3402 // mechanism handles the partially-substituted argument pack directly. 3403 Deduced.reserve(TemplateParams->size()); 3404 for (unsigned I = 0, N = ExplicitArgumentList->size(); I != N; ++I) { 3405 const TemplateArgument &Arg = ExplicitArgumentList->get(I); 3406 if (I == PartiallySubstitutedPackIndex) 3407 Deduced.push_back(DeducedTemplateArgument()); 3408 else 3409 Deduced.push_back(Arg); 3410 } 3411 3412 return TDK_Success; 3413} 3414 3415/// Check whether the deduced argument type for a call to a function 3416/// template matches the actual argument type per C++ [temp.deduct.call]p4. 3417static Sema::TemplateDeductionResult 3418CheckOriginalCallArgDeduction(Sema &S, TemplateDeductionInfo &Info, 3419 Sema::OriginalCallArg OriginalArg, 3420 QualType DeducedA) { 3421 ASTContext &Context = S.Context; 3422 3423 auto Failed = [&]() -> Sema::TemplateDeductionResult { 3424 Info.FirstArg = TemplateArgument(DeducedA); 3425 Info.SecondArg = TemplateArgument(OriginalArg.OriginalArgType); 3426 Info.CallArgIndex = OriginalArg.ArgIdx; 3427 return OriginalArg.DecomposedParam ? Sema::TDK_DeducedMismatchNested 3428 : Sema::TDK_DeducedMismatch; 3429 }; 3430 3431 QualType A = OriginalArg.OriginalArgType; 3432 QualType OriginalParamType = OriginalArg.OriginalParamType; 3433 3434 // Check for type equality (top-level cv-qualifiers are ignored). 3435 if (Context.hasSameUnqualifiedType(A, DeducedA)) 3436 return Sema::TDK_Success; 3437 3438 // Strip off references on the argument types; they aren't needed for 3439 // the following checks. 3440 if (const ReferenceType *DeducedARef = DeducedA->getAs<ReferenceType>()) 3441 DeducedA = DeducedARef->getPointeeType(); 3442 if (const ReferenceType *ARef = A->getAs<ReferenceType>()) 3443 A = ARef->getPointeeType(); 3444 3445 // C++ [temp.deduct.call]p4: 3446 // [...] However, there are three cases that allow a difference: 3447 // - If the original P is a reference type, the deduced A (i.e., the 3448 // type referred to by the reference) can be more cv-qualified than 3449 // the transformed A. 3450 if (const ReferenceType *OriginalParamRef 3451 = OriginalParamType->getAs<ReferenceType>()) { 3452 // We don't want to keep the reference around any more. 3453 OriginalParamType = OriginalParamRef->getPointeeType(); 3454 3455 // FIXME: Resolve core issue (no number yet): if the original P is a 3456 // reference type and the transformed A is function type "noexcept F", 3457 // the deduced A can be F. 3458 QualType Tmp; 3459 if (A->isFunctionType() && S.IsFunctionConversion(A, DeducedA, Tmp)) 3460 return Sema::TDK_Success; 3461 3462 Qualifiers AQuals = A.getQualifiers(); 3463 Qualifiers DeducedAQuals = DeducedA.getQualifiers(); 3464 3465 // Under Objective-C++ ARC, the deduced type may have implicitly 3466 // been given strong or (when dealing with a const reference) 3467 // unsafe_unretained lifetime. If so, update the original 3468 // qualifiers to include this lifetime. 3469 if (S.getLangOpts().ObjCAutoRefCount && 3470 ((DeducedAQuals.getObjCLifetime() == Qualifiers::OCL_Strong && 3471 AQuals.getObjCLifetime() == Qualifiers::OCL_None) || 3472 (DeducedAQuals.hasConst() && 3473 DeducedAQuals.getObjCLifetime() == Qualifiers::OCL_ExplicitNone))) { 3474 AQuals.setObjCLifetime(DeducedAQuals.getObjCLifetime()); 3475 } 3476 3477 if (AQuals == DeducedAQuals) { 3478 // Qualifiers match; there's nothing to do. 3479 } else if (!DeducedAQuals.compatiblyIncludes(AQuals)) { 3480 return Failed(); 3481 } else { 3482 // Qualifiers are compatible, so have the argument type adopt the 3483 // deduced argument type's qualifiers as if we had performed the 3484 // qualification conversion. 3485 A = Context.getQualifiedType(A.getUnqualifiedType(), DeducedAQuals); 3486 } 3487 } 3488 3489 // - The transformed A can be another pointer or pointer to member 3490 // type that can be converted to the deduced A via a function pointer 3491 // conversion and/or a qualification conversion. 3492 // 3493 // Also allow conversions which merely strip __attribute__((noreturn)) from 3494 // function types (recursively). 3495 bool ObjCLifetimeConversion = false; 3496 QualType ResultTy; 3497 if ((A->isAnyPointerType() || A->isMemberPointerType()) && 3498 (S.IsQualificationConversion(A, DeducedA, false, 3499 ObjCLifetimeConversion) || 3500 S.IsFunctionConversion(A, DeducedA, ResultTy))) 3501 return Sema::TDK_Success; 3502 3503 // - If P is a class and P has the form simple-template-id, then the 3504 // transformed A can be a derived class of the deduced A. [...] 3505 // [...] Likewise, if P is a pointer to a class of the form 3506 // simple-template-id, the transformed A can be a pointer to a 3507 // derived class pointed to by the deduced A. 3508 if (const PointerType *OriginalParamPtr 3509 = OriginalParamType->getAs<PointerType>()) { 3510 if (const PointerType *DeducedAPtr = DeducedA->getAs<PointerType>()) { 3511 if (const PointerType *APtr = A->getAs<PointerType>()) { 3512 if (A->getPointeeType()->isRecordType()) { 3513 OriginalParamType = OriginalParamPtr->getPointeeType(); 3514 DeducedA = DeducedAPtr->getPointeeType(); 3515 A = APtr->getPointeeType(); 3516 } 3517 } 3518 } 3519 } 3520 3521 if (Context.hasSameUnqualifiedType(A, DeducedA)) 3522 return Sema::TDK_Success; 3523 3524 if (A->isRecordType() && isSimpleTemplateIdType(OriginalParamType) && 3525 S.IsDerivedFrom(Info.getLocation(), A, DeducedA)) 3526 return Sema::TDK_Success; 3527 3528 return Failed(); 3529} 3530 3531/// Find the pack index for a particular parameter index in an instantiation of 3532/// a function template with specific arguments. 3533/// 3534/// \return The pack index for whichever pack produced this parameter, or -1 3535/// if this was not produced by a parameter. Intended to be used as the 3536/// ArgumentPackSubstitutionIndex for further substitutions. 3537// FIXME: We should track this in OriginalCallArgs so we don't need to 3538// reconstruct it here. 3539static unsigned getPackIndexForParam(Sema &S, 3540 FunctionTemplateDecl *FunctionTemplate, 3541 const MultiLevelTemplateArgumentList &Args, 3542 unsigned ParamIdx) { 3543 unsigned Idx = 0; 3544 for (auto *PD : FunctionTemplate->getTemplatedDecl()->parameters()) { 3545 if (PD->isParameterPack()) { 3546 unsigned NumExpansions = 3547 S.getNumArgumentsInExpansion(PD->getType(), Args).getValueOr(1); 3548 if (Idx + NumExpansions > ParamIdx) 3549 return ParamIdx - Idx; 3550 Idx += NumExpansions; 3551 } else { 3552 if (Idx == ParamIdx) 3553 return -1; // Not a pack expansion 3554 ++Idx; 3555 } 3556 } 3557 3558 llvm_unreachable("parameter index would not be produced from template")::llvm::llvm_unreachable_internal("parameter index would not be produced from template"
, "/build/llvm-toolchain-snapshot-14~++20211110111138+cffbfd01e37b/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 3558)
; 3559} 3560 3561/// Finish template argument deduction for a function template, 3562/// checking the deduced template arguments for completeness and forming 3563/// the function template specialization. 3564/// 3565/// \param OriginalCallArgs If non-NULL, the original call arguments against 3566/// which the deduced argument types should be compared. 3567Sema::TemplateDeductionResult Sema::FinishTemplateArgumentDeduction( 3568 FunctionTemplateDecl *FunctionTemplate, 3569 SmallVectorImpl<DeducedTemplateArgument> &Deduced, 3570 unsigned NumExplicitlySpecified, FunctionDecl *&Specialization, 3571 TemplateDeductionInfo &Info, 3572 SmallVectorImpl<OriginalCallArg> const *OriginalCallArgs, 3573 bool PartialOverloading, llvm::function_ref<bool()> CheckNonDependent) { 3574 // Unevaluated SFINAE context. 3575 EnterExpressionEvaluationContext Unevaluated( 3576 *this, Sema::ExpressionEvaluationContext::Unevaluated); 3577 SFINAETrap Trap(*this); 3578 3579 // Enter a new template instantiation context while we instantiate the 3580 // actual function declaration. 3581 SmallVector<TemplateArgument, 4> DeducedArgs(Deduced.begin(), Deduced.end()); 3582 InstantiatingTemplate Inst( 3583 *this, Info.getLocation(), FunctionTemplate, DeducedArgs, 3584 CodeSynthesisContext::DeducedTemplateArgumentSubstitution, Info); 3585 if (Inst.isInvalid()) 3586 return TDK_InstantiationDepth; 3587 3588 ContextRAII SavedContext(*this, FunctionTemplate->getTemplatedDecl()); 3589 3590 // C++ [temp.deduct.type]p2: 3591 // [...] or if any template argument remains neither deduced nor 3592 // explicitly specified, template argument deduction fails. 3593 SmallVector<TemplateArgument, 4> Builder; 3594 if (auto Result = ConvertDeducedTemplateArguments( 3595 *this, FunctionTemplate, /*IsDeduced*/true, Deduced, Info, Builder, 3596 CurrentInstantiationScope, NumExplicitlySpecified, 3597 PartialOverloading)) 3598 return Result; 3599 3600 // C++ [temp.deduct.call]p10: [DR1391] 3601 // If deduction succeeds for all parameters that contain 3602 // template-parameters that participate in template argument deduction, 3603 // and all template arguments are explicitly specified, deduced, or 3604 // obtained from default template arguments, remaining parameters are then 3605 // compared with the corresponding arguments. For each remaining parameter 3606 // P with a type that was non-dependent before substitution of any 3607 // explicitly-specified template arguments, if the corresponding argument 3608 // A cannot be implicitly converted to P, deduction fails. 3609 if (CheckNonDependent()) 3610 return TDK_NonDependentConversionFailure; 3611 3612 // Form the template argument list from the deduced template arguments. 3613 TemplateArgumentList *DeducedArgumentList 3614 = TemplateArgumentList::CreateCopy(Context, Builder); 3615 Info.reset(DeducedArgumentList); 3616 3617 // Substitute the deduced template arguments into the function template 3618 // declaration to produce the function template specialization. 3619 DeclContext *Owner = FunctionTemplate->getDeclContext(); 3620 if (FunctionTemplate->getFriendObjectKind()) 3621 Owner = FunctionTemplate->getLexicalDeclContext(); 3622 MultiLevelTemplateArgumentList SubstArgs(*DeducedArgumentList); 3623 Specialization = cast_or_null<FunctionDecl>( 3624 SubstDecl(FunctionTemplate->getTemplatedDecl(), Owner, SubstArgs)); 3625 if (!Specialization || Specialization->isInvalidDecl()) 3626 return TDK_SubstitutionFailure; 3627 3628 assert(Specialization->getPrimaryTemplate()->getCanonicalDecl() ==(static_cast <bool> (Specialization->getPrimaryTemplate
()->getCanonicalDecl() == FunctionTemplate->getCanonicalDecl
()) ? void (0) : __assert_fail ("Specialization->getPrimaryTemplate()->getCanonicalDecl() == FunctionTemplate->getCanonicalDecl()"
, "/build/llvm-toolchain-snapshot-14~++20211110111138+cffbfd01e37b/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 3629, __extension__ __PRETTY_FUNCTION__))
3629 FunctionTemplate->getCanonicalDecl())(static_cast <bool> (Specialization->getPrimaryTemplate
()->getCanonicalDecl() == FunctionTemplate->getCanonicalDecl
()) ? void (0) : __assert_fail ("Specialization->getPrimaryTemplate()->getCanonicalDecl() == FunctionTemplate->getCanonicalDecl()"
, "/build/llvm-toolchain-snapshot-14~++20211110111138+cffbfd01e37b/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 3629, __extension__ __PRETTY_FUNCTION__))
; 3630 3631 // If the template argument list is owned by the function template 3632 // specialization, release it. 3633 if (Specialization->getTemplateSpecializationArgs() == DeducedArgumentList && 3634 !Trap.hasErrorOccurred()) 3635 Info.take(); 3636 3637 // There may have been an error that did not prevent us from constructing a 3638 // declaration. Mark the declaration invalid and return with a substitution 3639 // failure. 3640 if (Trap.hasErrorOccurred()) { 3641 Specialization->setInvalidDecl(true); 3642 return TDK_SubstitutionFailure; 3643 } 3644 3645 // C++2a [temp.deduct]p5 3646 // [...] When all template arguments have been deduced [...] all uses of 3647 // template parameters [...] are replaced with the corresponding deduced 3648 // or default argument values. 3649 // [...] If the function template has associated constraints 3650 // ([temp.constr.decl]), those constraints are checked for satisfaction 3651 // ([temp.constr.constr]). If the constraints are not satisfied, type 3652 // deduction fails. 3653 if (!PartialOverloading || 3654 (Builder.size() == FunctionTemplate->getTemplateParameters()->size())) { 3655 if (CheckInstantiatedFunctionTemplateConstraints(Info.getLocation(), 3656 Specialization, Builder, Info.AssociatedConstraintsSatisfaction)) 3657 return TDK_MiscellaneousDeductionFailure; 3658 3659 if (!Info.AssociatedConstraintsSatisfaction.IsSatisfied) { 3660 Info.reset(TemplateArgumentList::CreateCopy(Context, Builder)); 3661 return TDK_ConstraintsNotSatisfied; 3662 } 3663 } 3664 3665 if (OriginalCallArgs) { 3666 // C++ [temp.deduct.call]p4: 3667 // In general, the deduction process attempts to find template argument 3668 // values that will make the deduced A identical to A (after the type A 3669 // is transformed as described above). [...] 3670 llvm::SmallDenseMap<std::pair<unsigned, QualType>, QualType> DeducedATypes; 3671 for (unsigned I = 0, N = OriginalCallArgs->size(); I != N; ++I) { 3672 OriginalCallArg OriginalArg = (*OriginalCallArgs)[I]; 3673 3674 auto ParamIdx = OriginalArg.ArgIdx; 3675 if (ParamIdx >= Specialization->getNumParams()) 3676 // FIXME: This presumably means a pack ended up smaller than we 3677 // expected while deducing. Should this not result in deduction 3678 // failure? Can it even happen? 3679 continue; 3680 3681 QualType DeducedA; 3682 if (!OriginalArg.DecomposedParam) { 3683 // P is one of the function parameters, just look up its substituted 3684 // type. 3685 DeducedA = Specialization->getParamDecl(ParamIdx)->getType(); 3686 } else { 3687 // P is a decomposed element of a parameter corresponding to a 3688 // braced-init-list argument. Substitute back into P to find the 3689 // deduced A. 3690 QualType &CacheEntry = 3691 DeducedATypes[{ParamIdx, OriginalArg.OriginalParamType}]; 3692 if (CacheEntry.isNull()) { 3693 ArgumentPackSubstitutionIndexRAII PackIndex( 3694 *this, getPackIndexForParam(*this, FunctionTemplate, SubstArgs, 3695 ParamIdx)); 3696 CacheEntry = 3697 SubstType(OriginalArg.OriginalParamType, SubstArgs, 3698 Specialization->getTypeSpecStartLoc(), 3699 Specialization->getDeclName()); 3700 } 3701 DeducedA = CacheEntry; 3702 } 3703 3704 if (auto TDK = 3705 CheckOriginalCallArgDeduction(*this, Info, OriginalArg, DeducedA)) 3706 return TDK; 3707 } 3708 } 3709 3710 // If we suppressed any diagnostics while performing template argument 3711 // deduction, and if we haven't already instantiated this declaration, 3712 // keep track of these diagnostics. They'll be emitted if this specialization 3713 // is actually used. 3714 if (Info.diag_begin() != Info.diag_end()) { 3715 SuppressedDiagnosticsMap::iterator 3716 Pos = SuppressedDiagnostics.find(Specialization->getCanonicalDecl()); 3717 if (Pos == SuppressedDiagnostics.end()) 3718 SuppressedDiagnostics[Specialization->getCanonicalDecl()] 3719 .append(Info.diag_begin(), Info.diag_end()); 3720 } 3721 3722 return TDK_Success; 3723} 3724 3725/// Gets the type of a function for template-argument-deducton 3726/// purposes when it's considered as part of an overload set. 3727static QualType GetTypeOfFunction(Sema &S, const OverloadExpr::FindResult &R, 3728 FunctionDecl *Fn) { 3729 // We may need to deduce the return type of the function now. 3730 if (S.getLangOpts().CPlusPlus14 && Fn->getReturnType()->isUndeducedType() && 3731 S.DeduceReturnType(Fn, R.Expression->getExprLoc(), /*Diagnose*/ false)) 3732 return {}; 3733 3734 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) 3735 if (Method->isInstance()) { 3736 // An instance method that's referenced in a form that doesn't 3737 // look like a member pointer is just invalid. 3738 if (!R.HasFormOfMemberPointer) 3739 return {}; 3740 3741 return S.Context.getMemberPointerType(Fn->getType(), 3742 S.Context.getTypeDeclType(Method->getParent()).getTypePtr()); 3743 } 3744 3745 if (!R.IsAddressOfOperand) return Fn->getType(); 3746 return S.Context.getPointerType(Fn->getType()); 3747} 3748 3749/// Apply the deduction rules for overload sets. 3750/// 3751/// \return the null type if this argument should be treated as an 3752/// undeduced context 3753static QualType 3754ResolveOverloadForDeduction(Sema &S, TemplateParameterList *TemplateParams, 3755 Expr *Arg, QualType ParamType, 3756 bool ParamWasReference) { 3757 3758 OverloadExpr::FindResult R = OverloadExpr::find(Arg); 3759 3760 OverloadExpr *Ovl = R.Expression; 3761 3762 // C++0x [temp.deduct.call]p4 3763 unsigned TDF = 0; 3764 if (ParamWasReference) 3765 TDF |= TDF_ParamWithReferenceType; 3766 if (R.IsAddressOfOperand) 3767 TDF |= TDF_IgnoreQualifiers; 3768 3769 // C++0x [temp.deduct.call]p6: 3770 // When P is a function type, pointer to function type, or pointer 3771 // to member function type: 3772 3773 if (!ParamType->isFunctionType() && 3774 !ParamType->isFunctionPointerType() && 3775 !ParamType->isMemberFunctionPointerType()) { 3776 if (Ovl->hasExplicitTemplateArgs()) { 3777 // But we can still look for an explicit specialization. 3778 if (FunctionDecl *ExplicitSpec 3779 = S.ResolveSingleFunctionTemplateSpecialization(Ovl)) 3780 return GetTypeOfFunction(S, R, ExplicitSpec); 3781 } 3782 3783 DeclAccessPair DAP; 3784 if (FunctionDecl *Viable = 3785 S.resolveAddressOfSingleOverloadCandidate(Arg, DAP)) 3786 return GetTypeOfFunction(S, R, Viable); 3787 3788 return {}; 3789 } 3790 3791 // Gather the explicit template arguments, if any. 3792 TemplateArgumentListInfo ExplicitTemplateArgs; 3793 if (Ovl->hasExplicitTemplateArgs()) 3794 Ovl->copyTemplateArgumentsInto(ExplicitTemplateArgs); 3795 QualType Match; 3796 for (UnresolvedSetIterator I = Ovl->decls_begin(), 3797 E = Ovl->decls_end(); I != E; ++I) { 3798 NamedDecl *D = (*I)->getUnderlyingDecl(); 3799 3800 if (FunctionTemplateDecl *FunTmpl = dyn_cast<FunctionTemplateDecl>(D)) { 3801 // - If the argument is an overload set containing one or more 3802 // function templates, the parameter is treated as a 3803 // non-deduced context. 3804 if (!Ovl->hasExplicitTemplateArgs()) 3805 return {}; 3806 3807 // Otherwise, see if we can resolve a function type 3808 FunctionDecl *Specialization = nullptr; 3809 TemplateDeductionInfo Info(Ovl->getNameLoc()); 3810 if (S.DeduceTemplateArguments(FunTmpl, &ExplicitTemplateArgs, 3811 Specialization, Info)) 3812 continue; 3813 3814 D = Specialization; 3815 } 3816 3817 FunctionDecl *Fn = cast<FunctionDecl>(D); 3818 QualType ArgType = GetTypeOfFunction(S, R, Fn); 3819 if (ArgType.isNull()) continue; 3820 3821 // Function-to-pointer conversion. 3822 if (!ParamWasReference && ParamType->isPointerType() && 3823 ArgType->isFunctionType()) 3824 ArgType = S.Context.getPointerType(ArgType); 3825 3826 // - If the argument is an overload set (not containing function 3827 // templates), trial argument deduction is attempted using each 3828 // of the members of the set. If deduction succeeds for only one 3829 // of the overload set members, that member is used as the 3830 // argument value for the deduction. If deduction succeeds for 3831 // more than one member of the overload set the parameter is 3832 // treated as a non-deduced context. 3833 3834 // We do all of this in a fresh context per C++0x [temp.deduct.type]p2: 3835 // Type deduction is done independently for each P/A pair, and 3836 // the deduced template argument values are then combined. 3837 // So we do not reject deductions which were made elsewhere. 3838 SmallVector<DeducedTemplateArgument, 8> 3839 Deduced(TemplateParams->size()); 3840 TemplateDeductionInfo Info(Ovl->getNameLoc()); 3841 Sema::TemplateDeductionResult Result 3842 = DeduceTemplateArgumentsByTypeMatch(S, TemplateParams, ParamType, 3843 ArgType, Info, Deduced, TDF); 3844 if (Result) continue; 3845 if (!Match.isNull()) 3846 return {}; 3847 Match = ArgType; 3848 } 3849 3850 return Match; 3851} 3852 3853/// Perform the adjustments to the parameter and argument types 3854/// described in C++ [temp.deduct.call]. 3855/// 3856/// \returns true if the caller should not attempt to perform any template 3857/// argument deduction based on this P/A pair because the argument is an 3858/// overloaded function set that could not be resolved. 3859static bool AdjustFunctionParmAndArgTypesForDeduction( 3860 Sema &S, TemplateParameterList *TemplateParams, unsigned FirstInnerIndex, 3861 QualType &ParamType, QualType &ArgType, Expr *Arg, unsigned &TDF) { 3862 // C++0x [temp.deduct.call]p3: 3863 // If P is a cv-qualified type, the top level cv-qualifiers of P's type 3864 // are ignored for type deduction. 3865 if (ParamType.hasQualifiers()) 3866 ParamType = ParamType.getUnqualifiedType(); 3867 3868 // [...] If P is a reference type, the type referred to by P is 3869 // used for type deduction. 3870 const ReferenceType *ParamRefType = ParamType->getAs<ReferenceType>(); 3871 if (ParamRefType) 3872 ParamType = ParamRefType->getPointeeType(); 3873 3874 // Overload sets usually make this parameter an undeduced context, 3875 // but there are sometimes special circumstances. Typically 3876 // involving a template-id-expr. 3877 if (ArgType == S.Context.OverloadTy) { 3878 ArgType = ResolveOverloadForDeduction(S, TemplateParams, 3879 Arg, ParamType, 3880 ParamRefType != nullptr); 3881 if (ArgType.isNull()) 3882 return true; 3883 } 3884 3885 if (ParamRefType) { 3886 // If the argument has incomplete array type, try to complete its type. 3887 if (ArgType->isIncompleteArrayType()) 3888 ArgType = S.getCompletedType(Arg); 3889 3890 // C++1z [temp.deduct.call]p3: 3891 // If P is a forwarding reference and the argument is an lvalue, the type 3892 // "lvalue reference to A" is used in place of A for type deduction. 3893 if (isForwardingReference(QualType(ParamRefType, 0), FirstInnerIndex) && 3894 Arg->isLValue()) { 3895 if (S.getLangOpts().OpenCL && !ArgType.hasAddressSpace()) 3896 ArgType = S.Context.getAddrSpaceQualType( 3897 ArgType, S.Context.getDefaultOpenCLPointeeAddrSpace()); 3898 ArgType = S.Context.getLValueReferenceType(ArgType); 3899 } 3900 } else { 3901 // C++ [temp.deduct.call]p2: 3902 // If P is not a reference type: 3903 // - If A is an array type, the pointer type produced by the 3904 // array-to-pointer standard conversion (4.2) is used in place of 3905 // A for type deduction; otherwise, 3906 if (ArgType->isArrayType()) 3907 ArgType = S.Context.getArrayDecayedType(ArgType); 3908 // - If A is a function type, the pointer type produced by the 3909 // function-to-pointer standard conversion (4.3) is used in place 3910 // of A for type deduction; otherwise, 3911 else if (ArgType->isFunctionType()) 3912 ArgType = S.Context.getPointerType(ArgType); 3913 else { 3914 // - If A is a cv-qualified type, the top level cv-qualifiers of A's 3915 // type are ignored for type deduction. 3916 ArgType = ArgType.getUnqualifiedType(); 3917 } 3918 } 3919 3920 // C++0x [temp.deduct.call]p4: 3921 // In general, the deduction process attempts to find template argument 3922 // values that will make the deduced A identical to A (after the type A 3923 // is transformed as described above). [...] 3924 TDF = TDF_SkipNonDependent; 3925 3926 // - If the original P is a reference type, the deduced A (i.e., the 3927 // type referred to by the reference) can be more cv-qualified than 3928 // the transformed A. 3929 if (ParamRefType) 3930 TDF |= TDF_ParamWithReferenceType; 3931 // - The transformed A can be another pointer or pointer to member 3932 // type that can be converted to the deduced A via a qualification 3933 // conversion (4.4). 3934 if (ArgType->isPointerType() || ArgType->isMemberPointerType() || 3935 ArgType->isObjCObjectPointerType()) 3936 TDF |= TDF_IgnoreQualifiers; 3937 // - If P is a class and P has the form simple-template-id, then the 3938 // transformed A can be a derived class of the deduced A. Likewise, 3939 // if P is a pointer to a class of the form simple-template-id, the 3940 // transformed A can be a pointer to a derived class pointed to by 3941 // the deduced A. 3942 if (isSimpleTemplateIdType(ParamType) || 3943 (isa<PointerType>(ParamType) && 3944 isSimpleTemplateIdType( 3945 ParamType->castAs<PointerType>()->getPointeeType()))) 3946 TDF |= TDF_DerivedClass; 3947 3948 return false; 3949} 3950 3951static bool 3952hasDeducibleTemplateParameters(Sema &S, FunctionTemplateDecl *FunctionTemplate, 3953 QualType T); 3954 3955static Sema::TemplateDeductionResult DeduceTemplateArgumentsFromCallArgument( 3956 Sema &S, TemplateParameterList *TemplateParams, unsigned FirstInnerIndex, 3957 QualType ParamType, Expr *Arg, TemplateDeductionInfo &Info, 3958 SmallVectorImpl<DeducedTemplateArgument> &Deduced, 3959 SmallVectorImpl<Sema::OriginalCallArg> &OriginalCallArgs, 3960 bool DecomposedParam, unsigned ArgIdx, unsigned TDF); 3961 3962/// Attempt template argument deduction from an initializer list 3963/// deemed to be an argument in a function call. 3964static Sema::TemplateDeductionResult DeduceFromInitializerList( 3965 Sema &S, TemplateParameterList *TemplateParams, QualType AdjustedParamType, 3966 InitListExpr *ILE, TemplateDeductionInfo &Info, 3967 SmallVectorImpl<DeducedTemplateArgument> &Deduced, 3968 SmallVectorImpl<Sema::OriginalCallArg> &OriginalCallArgs, unsigned ArgIdx, 3969 unsigned TDF) { 3970 // C++ [temp.deduct.call]p1: (CWG 1591) 3971 // If removing references and cv-qualifiers from P gives 3972 // std::initializer_list<P0> or P0[N] for some P0 and N and the argument is 3973 // a non-empty initializer list, then deduction is performed instead for 3974 // each element of the initializer list, taking P0 as a function template 3975 // parameter type and the initializer element as its argument 3976 // 3977 // We've already removed references and cv-qualifiers here. 3978 if (!ILE->getNumInits()) 3979 return Sema::TDK_Success; 3980 3981 QualType ElTy; 3982 auto *ArrTy = S.Context.getAsArrayType(AdjustedParamType); 3983 if (ArrTy) 3984 ElTy = ArrTy->getElementType(); 3985 else if (!S.isStdInitializerList(AdjustedParamType, &ElTy)) { 3986 // Otherwise, an initializer list argument causes the parameter to be 3987 // considered a non-deduced context 3988 return Sema::TDK_Success; 3989 } 3990 3991 // Resolving a core issue: a braced-init-list containing any designators is 3992 // a non-deduced context. 3993 for (Expr *E : ILE->inits()) 3994 if (isa<DesignatedInitExpr>(E)) 3995 return Sema::TDK_Success; 3996 3997 // Deduction only needs to be done for dependent types. 3998 if (ElTy->isDependentType()) { 3999 for (Expr *E : ILE->inits()) { 4000 if (auto Result = DeduceTemplateArgumentsFromCallArgument( 4001 S, TemplateParams, 0, ElTy, E, Info, Deduced, OriginalCallArgs, true, 4002 ArgIdx, TDF)) 4003 return Result; 4004 } 4005 } 4006 4007 // in the P0[N] case, if N is a non-type template parameter, N is deduced 4008 // from the length of the initializer list. 4009 if (auto *DependentArrTy = dyn_cast_or_null<DependentSizedArrayType>(ArrTy)) { 4010 // Determine the array bound is something we can deduce. 4011 if (const NonTypeTemplateParmDecl *NTTP = 4012 getDeducedParameterFromExpr(Info, DependentArrTy->getSizeExpr())) { 4013 // We can perform template argument deduction for the given non-type 4014 // template parameter. 4015 // C++ [temp.deduct.type]p13: 4016 // The type of N in the type T[N] is std::size_t. 4017 QualType T = S.Context.getSizeType(); 4018 llvm::APInt Size(S.Context.getIntWidth(T), ILE->getNumInits()); 4019 if (auto Result = DeduceNonTypeTemplateArgument( 4020 S, TemplateParams, NTTP, llvm::APSInt(Size), T, 4021 /*ArrayBound=*/true, Info, Deduced)) 4022 return Result; 4023 } 4024 } 4025 4026 return Sema::TDK_Success; 4027} 4028 4029/// Perform template argument deduction per [temp.deduct.call] for a 4030/// single parameter / argument pair. 4031static Sema::TemplateDeductionResult DeduceTemplateArgumentsFromCallArgument( 4032 Sema &S, TemplateParameterList *TemplateParams, unsigned FirstInnerIndex, 4033 QualType ParamType, Expr *Arg, TemplateDeductionInfo &Info, 4034 SmallVectorImpl<DeducedTemplateArgument> &Deduced, 4035 SmallVectorImpl<Sema::OriginalCallArg> &OriginalCallArgs, 4036 bool DecomposedParam, unsigned ArgIdx, unsigned TDF) { 4037 QualType ArgType = Arg->getType(); 4038 QualType OrigParamType = ParamType; 4039 4040 // If P is a reference type [...] 4041 // If P is a cv-qualified type [...] 4042 if (AdjustFunctionParmAndArgTypesForDeduction( 4043 S, TemplateParams, FirstInnerIndex, ParamType, ArgType, Arg, TDF)) 4044 return Sema::TDK_Success; 4045 4046 // If [...] the argument is a non-empty initializer list [...] 4047 if (InitListExpr *ILE = dyn_cast<InitListExpr>(Arg)) 4048 return DeduceFromInitializerList(S, TemplateParams, ParamType, ILE, Info, 4049 Deduced, OriginalCallArgs, ArgIdx, TDF); 4050 4051 // [...] the deduction process attempts to find template argument values 4052 // that will make the deduced A identical to A 4053 // 4054 // Keep track of the argument type and corresponding parameter index, 4055 // so we can check for compatibility between the deduced A and A. 4056 OriginalCallArgs.push_back( 4057 Sema::OriginalCallArg(OrigParamType, DecomposedParam, ArgIdx, ArgType)); 4058 return DeduceTemplateArgumentsByTypeMatch(S, TemplateParams, ParamType, 4059 ArgType, Info, Deduced, TDF); 4060} 4061 4062/// Perform template argument deduction from a function call 4063/// (C++ [temp.deduct.call]). 4064/// 4065/// \param FunctionTemplate the function template for which we are performing 4066/// template argument deduction. 4067/// 4068/// \param ExplicitTemplateArgs the explicit template arguments provided 4069/// for this call. 4070/// 4071/// \param Args the function call arguments 4072/// 4073/// \param Specialization if template argument deduction was successful, 4074/// this will be set to the function template specialization produced by 4075/// template argument deduction. 4076/// 4077/// \param Info the argument will be updated to provide additional information 4078/// about template argument deduction. 4079/// 4080/// \param CheckNonDependent A callback to invoke to check conversions for 4081/// non-dependent parameters, between deduction and substitution, per DR1391. 4082/// If this returns true, substitution will be skipped and we return 4083/// TDK_NonDependentConversionFailure. The callback is passed the parameter 4084/// types (after substituting explicit template arguments). 4085/// 4086/// \returns the result of template argument deduction. 4087Sema::TemplateDeductionResult Sema::DeduceTemplateArguments( 4088 FunctionTemplateDecl *FunctionTemplate, 4089 TemplateArgumentListInfo *ExplicitTemplateArgs, ArrayRef<Expr *> Args, 4090 FunctionDecl *&Specialization, TemplateDeductionInfo &Info, 4091 bool PartialOverloading, 4092 llvm::function_ref<bool(ArrayRef<QualType>)> CheckNonDependent) { 4093 if (FunctionTemplate->isInvalidDecl()) 4094 return TDK_Invalid; 4095 4096 FunctionDecl *Function = FunctionTemplate->getTemplatedDecl(); 4097 unsigned NumParams = Function->getNumParams(); 4098 4099 unsigned FirstInnerIndex = getFirstInnerIndex(FunctionTemplate); 4100 4101 // C++ [temp.deduct.call]p1: 4102 // Template argument deduction is done by comparing each function template 4103 // parameter type (call it P) with the type of the corresponding argument 4104 // of the call (call it A) as described below. 4105 if (Args.size() < Function->getMinRequiredArguments() && !PartialOverloading) 4106 return TDK_TooFewArguments; 4107 else if (TooManyArguments(NumParams, Args.size(), PartialOverloading)) { 4108 const auto *Proto = Function->getType()->castAs<FunctionProtoType>(); 4109 if (Proto->isTemplateVariadic()) 4110 /* Do nothing */; 4111 else if (!Proto->isVariadic()) 4112 return TDK_TooManyArguments; 4113 } 4114 4115 // The types of the parameters from which we will perform template argument 4116 // deduction. 4117 LocalInstantiationScope InstScope(*this); 4118 TemplateParameterList *TemplateParams 4119 = FunctionTemplate->getTemplateParameters(); 4120 SmallVector<DeducedTemplateArgument, 4> Deduced; 4121 SmallVector<QualType, 8> ParamTypes; 4122 unsigned NumExplicitlySpecified = 0; 4123 if (ExplicitTemplateArgs) { 4124 TemplateDeductionResult Result; 4125 runWithSufficientStackSpace(Info.getLocation(), [&] { 4126 Result = SubstituteExplicitTemplateArguments( 4127 FunctionTemplate, *ExplicitTemplateArgs, Deduced, ParamTypes, nullptr, 4128 Info); 4129 }); 4130 if (Result) 4131 return Result; 4132 4133 NumExplicitlySpecified = Deduced.size(); 4134 } else { 4135 // Just fill in the parameter types from the function declaration. 4136 for (unsigned I = 0; I != NumParams; ++I) 4137 ParamTypes.push_back(Function->getParamDecl(I)->getType()); 4138 } 4139 4140 SmallVector<OriginalCallArg, 8> OriginalCallArgs; 4141 4142 // Deduce an argument of type ParamType from an expression with index ArgIdx. 4143 auto DeduceCallArgument = [&](QualType ParamType, unsigned ArgIdx) { 4144 // C++ [demp.deduct.call]p1: (DR1391) 4145 // Template argument deduction is done by comparing each function template 4146 // parameter that contains template-parameters that participate in 4147 // template argument deduction ... 4148 if (!hasDeducibleTemplateParameters(*this, FunctionTemplate, ParamType)) 4149 return Sema::TDK_Success; 4150 4151 // ... with the type of the corresponding argument 4152 return DeduceTemplateArgumentsFromCallArgument( 4153 *this, TemplateParams, FirstInnerIndex, ParamType, Args[ArgIdx], Info, Deduced, 4154 OriginalCallArgs, /*Decomposed*/false, ArgIdx, /*TDF*/ 0); 4155 }; 4156 4157 // Deduce template arguments from the function parameters. 4158 Deduced.resize(TemplateParams->size()); 4159 SmallVector<QualType, 8> ParamTypesForArgChecking; 4160 for (unsigned ParamIdx = 0, NumParamTypes = ParamTypes.size(), ArgIdx = 0; 4161 ParamIdx != NumParamTypes; ++ParamIdx) { 4162 QualType ParamType = ParamTypes[ParamIdx]; 4163 4164 const PackExpansionType *ParamExpansion = 4165 dyn_cast<PackExpansionType>(ParamType); 4166 if (!ParamExpansion) { 4167 // Simple case: matching a function parameter to a function argument. 4168 if (ArgIdx >= Args.size()) 4169 break; 4170 4171 ParamTypesForArgChecking.push_back(ParamType); 4172 if (auto Result = DeduceCallArgument(ParamType, ArgIdx++)) 4173 return Result; 4174 4175 continue; 4176 } 4177 4178 QualType ParamPattern = ParamExpansion->getPattern(); 4179 PackDeductionScope PackScope(*this, TemplateParams, Deduced, Info, 4180 ParamPattern); 4181 4182 // C++0x [temp.deduct.call]p1: 4183 // For a function parameter pack that occurs at the end of the 4184 // parameter-declaration-list, the type A of each remaining argument of 4185 // the call is compared with the type P of the declarator-id of the 4186 // function parameter pack. Each comparison deduces template arguments 4187 // for subsequent positions in the template parameter packs expanded by 4188 // the function parameter pack. When a function parameter pack appears 4189 // in a non-deduced context [not at the end of the list], the type of 4190 // that parameter pack is never deduced. 4191 // 4192 // FIXME: The above rule allows the size of the parameter pack to change 4193 // after we skip it (in the non-deduced case). That makes no sense, so 4194 // we instead notionally deduce the pack against N arguments, where N is 4195 // the length of the explicitly-specified pack if it's expanded by the 4196 // parameter pack and 0 otherwise, and we treat each deduction as a 4197 // non-deduced context. 4198 if (ParamIdx + 1 == NumParamTypes || PackScope.hasFixedArity()) { 4199 for (; ArgIdx < Args.size() && PackScope.hasNextElement(); 4200 PackScope.nextPackElement(), ++ArgIdx) { 4201 ParamTypesForArgChecking.push_back(ParamPattern); 4202 if (auto Result = DeduceCallArgument(ParamPattern, ArgIdx)) 4203 return Result; 4204 } 4205 } else { 4206 // If the parameter type contains an explicitly-specified pack that we 4207 // could not expand, skip the number of parameters notionally created 4208 // by the expansion. 4209 Optional<unsigned> NumExpansions = ParamExpansion->getNumExpansions(); 4210 if (NumExpansions && !PackScope.isPartiallyExpanded()) { 4211 for (unsigned I = 0; I != *NumExpansions && ArgIdx < Args.size(); 4212 ++I, ++ArgIdx) { 4213 ParamTypesForArgChecking.push_back(ParamPattern); 4214 // FIXME: Should we add OriginalCallArgs for these? What if the 4215 // corresponding argument is a list? 4216 PackScope.nextPackElement(); 4217 } 4218 } 4219 } 4220 4221 // Build argument packs for each of the parameter packs expanded by this 4222 // pack expansion. 4223 if (auto Result = PackScope.finish()) 4224 return Result; 4225 } 4226 4227 // Capture the context in which the function call is made. This is the context 4228 // that is needed when the accessibility of template arguments is checked. 4229 DeclContext *CallingCtx = CurContext; 4230 4231 TemplateDeductionResult Result; 4232 runWithSufficientStackSpace(Info.getLocation(), [&] { 4233 Result = FinishTemplateArgumentDeduction( 4234 FunctionTemplate, Deduced, NumExplicitlySpecified, Specialization, Info, 4235 &OriginalCallArgs, PartialOverloading, [&, CallingCtx]() { 4236 ContextRAII SavedContext(*this, CallingCtx); 4237 return CheckNonDependent(ParamTypesForArgChecking); 4238 }); 4239 }); 4240 return Result; 4241} 4242 4243QualType Sema::adjustCCAndNoReturn(QualType ArgFunctionType, 4244 QualType FunctionType, 4245 bool AdjustExceptionSpec) { 4246 if (ArgFunctionType.isNull()) 4247 return ArgFunctionType; 4248 4249 const auto *FunctionTypeP = FunctionType->castAs<FunctionProtoType>(); 4250 const auto *ArgFunctionTypeP = ArgFunctionType->castAs<FunctionProtoType>(); 4251 FunctionProtoType::ExtProtoInfo EPI = ArgFunctionTypeP->getExtProtoInfo(); 4252 bool Rebuild = false; 4253 4254 CallingConv CC = FunctionTypeP->getCallConv(); 4255 if (EPI.ExtInfo.getCC() != CC) { 4256 EPI.ExtInfo = EPI.ExtInfo.withCallingConv(CC); 4257 Rebuild = true; 4258 } 4259 4260 bool NoReturn = FunctionTypeP->getNoReturnAttr(); 4261 if (EPI.ExtInfo.getNoReturn() != NoReturn) { 4262 EPI.ExtInfo = EPI.ExtInfo.withNoReturn(NoReturn); 4263 Rebuild = true; 4264 } 4265 4266 if (AdjustExceptionSpec && (FunctionTypeP->hasExceptionSpec() || 4267 ArgFunctionTypeP->hasExceptionSpec())) { 4268 EPI.ExceptionSpec = FunctionTypeP->getExtProtoInfo().ExceptionSpec; 4269 Rebuild = true; 4270 } 4271 4272 if (!Rebuild) 4273 return ArgFunctionType; 4274 4275 return Context.getFunctionType(ArgFunctionTypeP->getReturnType(), 4276 ArgFunctionTypeP->getParamTypes(), EPI); 4277} 4278 4279/// Deduce template arguments when taking the address of a function 4280/// template (C++ [temp.deduct.funcaddr]) or matching a specialization to 4281/// a template. 4282/// 4283/// \param FunctionTemplate the function template for which we are performing 4284/// template argument deduction. 4285/// 4286/// \param ExplicitTemplateArgs the explicitly-specified template 4287/// arguments. 4288/// 4289/// \param ArgFunctionType the function type that will be used as the 4290/// "argument" type (A) when performing template argument deduction from the 4291/// function template's function type. This type may be NULL, if there is no 4292/// argument type to compare against, in C++0x [temp.arg.explicit]p3. 4293/// 4294/// \param Specialization if template argument deduction was successful, 4295/// this will be set to the function template specialization produced by 4296/// template argument deduction. 4297/// 4298/// \param Info the argument will be updated to provide additional information 4299/// about template argument deduction. 4300/// 4301/// \param IsAddressOfFunction If \c true, we are deducing as part of taking 4302/// the address of a function template per [temp.deduct.funcaddr] and 4303/// [over.over]. If \c false, we are looking up a function template 4304/// specialization based on its signature, per [temp.deduct.decl]. 4305/// 4306/// \returns the result of template argument deduction. 4307Sema::TemplateDeductionResult Sema::DeduceTemplateArguments( 4308 FunctionTemplateDecl *FunctionTemplate, 4309 TemplateArgumentListInfo *ExplicitTemplateArgs, QualType ArgFunctionType, 4310 FunctionDecl *&Specialization, TemplateDeductionInfo &Info, 4311 bool IsAddressOfFunction) { 4312 if (FunctionTemplate->isInvalidDecl()) 4313 return TDK_Invalid; 4314 4315 FunctionDecl *Function = FunctionTemplate->getTemplatedDecl(); 4316 TemplateParameterList *TemplateParams 4317 = FunctionTemplate->getTemplateParameters(); 4318 QualType FunctionType = Function->getType(); 4319 4320 // Substitute any explicit template arguments. 4321 LocalInstantiationScope InstScope(*this); 4322 SmallVector<DeducedTemplateArgument, 4> Deduced; 4323 unsigned NumExplicitlySpecified = 0; 4324 SmallVector<QualType, 4> ParamTypes; 4325 if (ExplicitTemplateArgs) { 4326 TemplateDeductionResult Result; 4327 runWithSufficientStackSpace(Info.getLocation(), [&] { 4328 Result = SubstituteExplicitTemplateArguments( 4329 FunctionTemplate, *ExplicitTemplateArgs, Deduced, ParamTypes, 4330 &FunctionType, Info); 4331 }); 4332 if (Result) 4333 return Result; 4334 4335 NumExplicitlySpecified = Deduced.size(); 4336 } 4337 4338 // When taking the address of a function, we require convertibility of 4339 // the resulting function type. Otherwise, we allow arbitrary mismatches 4340 // of calling convention and noreturn. 4341 if (!IsAddressOfFunction) 4342 ArgFunctionType = adjustCCAndNoReturn(ArgFunctionType, FunctionType, 4343 /*AdjustExceptionSpec*/false); 4344 4345 // Unevaluated SFINAE context. 4346 EnterExpressionEvaluationContext Unevaluated( 4347 *this, Sema::ExpressionEvaluationContext::Unevaluated); 4348 SFINAETrap Trap(*this); 4349 4350 Deduced.resize(TemplateParams->size()); 4351 4352 // If the function has a deduced return type, substitute it for a dependent 4353 // type so that we treat it as a non-deduced context in what follows. If we 4354 // are looking up by signature, the signature type should also have a deduced 4355 // return type, which we instead expect to exactly match. 4356 bool HasDeducedReturnType = false; 4357 if (getLangOpts().CPlusPlus14 && IsAddressOfFunction && 4358 Function->getReturnType()->getContainedAutoType()) { 4359 FunctionType = SubstAutoType(FunctionType, Context.DependentTy); 4360 HasDeducedReturnType = true; 4361 } 4362 4363 if (!ArgFunctionType.isNull() && !FunctionType.isNull()) { 4364 unsigned TDF = 4365 TDF_TopLevelParameterTypeList | TDF_AllowCompatibleFunctionType; 4366 // Deduce template arguments from the function type. 4367 if (TemplateDeductionResult Result 4368 = DeduceTemplateArgumentsByTypeMatch(*this, TemplateParams, 4369 FunctionType, ArgFunctionType, 4370 Info, Deduced, TDF)) 4371 return Result; 4372 } 4373 4374 TemplateDeductionResult Result; 4375 runWithSufficientStackSpace(Info.getLocation(), [&] { 4376 Result = FinishTemplateArgumentDeduction(FunctionTemplate, Deduced, 4377 NumExplicitlySpecified, 4378 Specialization, Info); 4379 }); 4380 if (Result) 4381 return Result; 4382 4383 // If the function has a deduced return type, deduce it now, so we can check 4384 // that the deduced function type matches the requested type. 4385 if (HasDeducedReturnType && 4386 Specialization->getReturnType()->isUndeducedType() && 4387 DeduceReturnType(Specialization, Info.getLocation(), false)) 4388 return TDK_MiscellaneousDeductionFailure; 4389 4390 // If the function has a dependent exception specification, resolve it now, 4391 // so we can check that the exception specification matches. 4392 auto *SpecializationFPT = 4393 Specialization->getType()->castAs<FunctionProtoType>(); 4394 if (getLangOpts().CPlusPlus17 && 4395 isUnresolvedExceptionSpec(SpecializationFPT->getExceptionSpecType()) && 4396 !ResolveExceptionSpec(Info.getLocation(), SpecializationFPT)) 4397 return TDK_MiscellaneousDeductionFailure; 4398 4399 // Adjust the exception specification of the argument to match the 4400 // substituted and resolved type we just formed. (Calling convention and 4401 // noreturn can't be dependent, so we don't actually need this for them 4402 // right now.) 4403 QualType SpecializationType = Specialization->getType(); 4404 if (!IsAddressOfFunction) 4405 ArgFunctionType = adjustCCAndNoReturn(ArgFunctionType, SpecializationType, 4406 /*AdjustExceptionSpec*/true); 4407 4408 // If the requested function type does not match the actual type of the 4409 // specialization with respect to arguments of compatible pointer to function 4410 // types, template argument deduction fails. 4411 if (!ArgFunctionType.isNull()) { 4412 if (IsAddressOfFunction && 4413 !isSameOrCompatibleFunctionType( 4414 Context.getCanonicalType(SpecializationType), 4415 Context.getCanonicalType(ArgFunctionType))) 4416 return TDK_MiscellaneousDeductionFailure; 4417 4418 if (!IsAddressOfFunction && 4419 !Context.hasSameType(SpecializationType, ArgFunctionType)) 4420 return TDK_MiscellaneousDeductionFailure; 4421 } 4422 4423 return TDK_Success; 4424} 4425 4426/// Deduce template arguments for a templated conversion 4427/// function (C++ [temp.deduct.conv]) and, if successful, produce a 4428/// conversion function template specialization. 4429Sema::TemplateDeductionResult 4430Sema::DeduceTemplateArguments(FunctionTemplateDecl *ConversionTemplate, 4431 QualType ToType, 4432 CXXConversionDecl *&Specialization, 4433 TemplateDeductionInfo &Info) { 4434 if (ConversionTemplate->isInvalidDecl()) 4435 return TDK_Invalid; 4436 4437 CXXConversionDecl *ConversionGeneric 4438 = cast<CXXConversionDecl>(ConversionTemplate->getTemplatedDecl()); 4439 4440 QualType FromType = ConversionGeneric->getConversionType(); 4441 4442 // Canonicalize the types for deduction. 4443 QualType P = Context.getCanonicalType(FromType); 4444 QualType A = Context.getCanonicalType(ToType); 4445 4446 // C++0x [temp.deduct.conv]p2: 4447 // If P is a reference type, the type referred to by P is used for 4448 // type deduction. 4449 if (const ReferenceType *PRef = P->getAs<ReferenceType>()) 4450 P = PRef->getPointeeType(); 4451 4452 // C++0x [temp.deduct.conv]p4: 4453 // [...] If A is a reference type, the type referred to by A is used 4454 // for type deduction. 4455 if (const ReferenceType *ARef = A->getAs<ReferenceType>()) { 4456 A = ARef->getPointeeType(); 4457 // We work around a defect in the standard here: cv-qualifiers are also 4458 // removed from P and A in this case, unless P was a reference type. This 4459 // seems to mostly match what other compilers are doing. 4460 if (!FromType->getAs<ReferenceType>()) { 4461 A = A.getUnqualifiedType(); 4462 P = P.getUnqualifiedType(); 4463 } 4464 4465 // C++ [temp.deduct.conv]p3: 4466 // 4467 // If A is not a reference type: 4468 } else { 4469 assert(!A->isReferenceType() && "Reference types were handled above")(static_cast <bool> (!A->isReferenceType() &&
"Reference types were handled above") ? void (0) : __assert_fail
("!A->isReferenceType() && \"Reference types were handled above\""
, "/build/llvm-toolchain-snapshot-14~++20211110111138+cffbfd01e37b/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 4469, __extension__ __PRETTY_FUNCTION__))
; 4470 4471 // - If P is an array type, the pointer type produced by the 4472 // array-to-pointer standard conversion (4.2) is used in place 4473 // of P for type deduction; otherwise, 4474 if (P->isArrayType()) 4475 P = Context.getArrayDecayedType(P); 4476 // - If P is a function type, the pointer type produced by the 4477 // function-to-pointer standard conversion (4.3) is used in 4478 // place of P for type deduction; otherwise, 4479 else if (P->isFunctionType()) 4480 P = Context.getPointerType(P); 4481 // - If P is a cv-qualified type, the top level cv-qualifiers of 4482 // P's type are ignored for type deduction. 4483 else 4484 P = P.getUnqualifiedType(); 4485 4486 // C++0x [temp.deduct.conv]p4: 4487 // If A is a cv-qualified type, the top level cv-qualifiers of A's 4488 // type are ignored for type deduction. If A is a reference type, the type 4489 // referred to by A is used for type deduction. 4490 A = A.getUnqualifiedType(); 4491 } 4492 4493 // Unevaluated SFINAE context. 4494 EnterExpressionEvaluationContext Unevaluated( 4495 *this, Sema::ExpressionEvaluationContext::Unevaluated); 4496 SFINAETrap Trap(*this); 4497 4498 // C++ [temp.deduct.conv]p1: 4499 // Template argument deduction is done by comparing the return 4500 // type of the template conversion function (call it P) with the 4501 // type that is required as the result of the conversion (call it 4502 // A) as described in 14.8.2.4. 4503 TemplateParameterList *TemplateParams 4504 = ConversionTemplate->getTemplateParameters(); 4505 SmallVector<DeducedTemplateArgument, 4> Deduced; 4506 Deduced.resize(TemplateParams->size()); 4507 4508 // C++0x [temp.deduct.conv]p4: 4509 // In general, the deduction process attempts to find template 4510 // argument values that will make the deduced A identical to 4511 // A. However, there are two cases that allow a difference: 4512 unsigned TDF = 0; 4513 // - If the original A is a reference type, A can be more 4514 // cv-qualified than the deduced A (i.e., the type referred to 4515 // by the reference) 4516 if (ToType->isReferenceType()) 4517 TDF |= TDF_ArgWithReferenceType; 4518 // - The deduced A can be another pointer or pointer to member 4519 // type that can be converted to A via a qualification 4520 // conversion. 4521 // 4522 // (C++0x [temp.deduct.conv]p6 clarifies that this only happens when 4523 // both P and A are pointers or member pointers. In this case, we 4524 // just ignore cv-qualifiers completely). 4525 if ((P->isPointerType() && A->isPointerType()) || 4526 (P->isMemberPointerType() && A->isMemberPointerType())) 4527 TDF |= TDF_IgnoreQualifiers; 4528 if (TemplateDeductionResult Result 4529 = DeduceTemplateArgumentsByTypeMatch(*this, TemplateParams, 4530 P, A, Info, Deduced, TDF)) 4531 return Result; 4532 4533 // Create an Instantiation Scope for finalizing the operator. 4534 LocalInstantiationScope InstScope(*this); 4535 // Finish template argument deduction. 4536 FunctionDecl *ConversionSpecialized = nullptr; 4537 TemplateDeductionResult Result; 4538 runWithSufficientStackSpace(Info.getLocation(), [&] { 4539 Result = FinishTemplateArgumentDeduction(ConversionTemplate, Deduced, 0, 4540 ConversionSpecialized, Info); 4541 }); 4542 Specialization = cast_or_null<CXXConversionDecl>(ConversionSpecialized); 4543 return Result; 4544} 4545 4546/// Deduce template arguments for a function template when there is 4547/// nothing to deduce against (C++0x [temp.arg.explicit]p3). 4548/// 4549/// \param FunctionTemplate the function template for which we are performing 4550/// template argument deduction. 4551/// 4552/// \param ExplicitTemplateArgs the explicitly-specified template 4553/// arguments. 4554/// 4555/// \param Specialization if template argument deduction was successful, 4556/// this will be set to the function template specialization produced by 4557/// template argument deduction. 4558/// 4559/// \param Info the argument will be updated to provide additional information 4560/// about template argument deduction. 4561/// 4562/// \param IsAddressOfFunction If \c true, we are deducing as part of taking 4563/// the address of a function template in a context where we do not have a 4564/// target type, per [over.over]. If \c false, we are looking up a function 4565/// template specialization based on its signature, which only happens when 4566/// deducing a function parameter type from an argument that is a template-id 4567/// naming a function template specialization. 4568/// 4569/// \returns the result of template argument deduction. 4570Sema::TemplateDeductionResult Sema::DeduceTemplateArguments( 4571 FunctionTemplateDecl *FunctionTemplate, 4572 TemplateArgumentListInfo *ExplicitTemplateArgs, 4573 FunctionDecl *&Specialization, TemplateDeductionInfo &Info, 4574 bool IsAddressOfFunction) { 4575 return DeduceTemplateArguments(FunctionTemplate, ExplicitTemplateArgs, 4576 QualType(), Specialization, Info, 4577 IsAddressOfFunction); 4578} 4579 4580namespace { 4581 struct DependentAuto { bool IsPack; }; 4582 4583 /// Substitute the 'auto' specifier or deduced template specialization type 4584 /// specifier within a type for a given replacement type. 4585 class SubstituteDeducedTypeTransform : 4586 public TreeTransform<SubstituteDeducedTypeTransform> { 4587 QualType Replacement; 4588 bool ReplacementIsPack; 4589 bool UseTypeSugar; 4590 4591 public: 4592 SubstituteDeducedTypeTransform(Sema &SemaRef, DependentAuto DA) 4593 : TreeTransform<SubstituteDeducedTypeTransform>(SemaRef), Replacement(), 4594 ReplacementIsPack(DA.IsPack), UseTypeSugar(true) {} 4595 4596 SubstituteDeducedTypeTransform(Sema &SemaRef, QualType Replacement, 4597 bool UseTypeSugar = true) 4598 : TreeTransform<SubstituteDeducedTypeTransform>(SemaRef), 4599 Replacement(Replacement), ReplacementIsPack(false), 4600 UseTypeSugar(UseTypeSugar) {} 4601 4602 QualType TransformDesugared(TypeLocBuilder &TLB, DeducedTypeLoc TL) { 4603 assert(isa<TemplateTypeParmType>(Replacement) &&(static_cast <bool> (isa<TemplateTypeParmType>(Replacement
) && "unexpected unsugared replacement kind") ? void (
0) : __assert_fail ("isa<TemplateTypeParmType>(Replacement) && \"unexpected unsugared replacement kind\""
, "/build/llvm-toolchain-snapshot-14~++20211110111138+cffbfd01e37b/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 4604, __extension__ __PRETTY_FUNCTION__))
4604 "unexpected unsugared replacement kind")(static_cast <bool> (isa<TemplateTypeParmType>(Replacement
) && "unexpected unsugared replacement kind") ? void (
0) : __assert_fail ("isa<TemplateTypeParmType>(Replacement) && \"unexpected unsugared replacement kind\""
, "/build/llvm-toolchain-snapshot-14~++20211110111138+cffbfd01e37b/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 4604, __extension__ __PRETTY_FUNCTION__))
; 4605 QualType Result = Replacement; 4606 TemplateTypeParmTypeLoc NewTL = TLB.push<TemplateTypeParmTypeLoc>(Result); 4607 NewTL.setNameLoc(TL.getNameLoc()); 4608 return Result; 4609 } 4610 4611 QualType TransformAutoType(TypeLocBuilder &TLB, AutoTypeLoc TL) { 4612 // If we're building the type pattern to deduce against, don't wrap the 4613 // substituted type in an AutoType. Certain template deduction rules 4614 // apply only when a template type parameter appears directly (and not if 4615 // the parameter is found through desugaring). For instance: 4616 // auto &&lref = lvalue; 4617 // must transform into "rvalue reference to T" not "rvalue reference to 4618 // auto type deduced as T" in order for [temp.deduct.call]p3 to apply. 4619 // 4620 // FIXME: Is this still necessary? 4621 if (!UseTypeSugar) 4622 return TransformDesugared(TLB, TL); 4623 4624 QualType Result = SemaRef.Context.getAutoType( 4625 Replacement, TL.getTypePtr()->getKeyword(), Replacement.isNull(), 4626 ReplacementIsPack, TL.getTypePtr()->getTypeConstraintConcept(), 4627 TL.getTypePtr()->getTypeConstraintArguments()); 4628 auto NewTL = TLB.push<AutoTypeLoc>(Result); 4629 NewTL.copy(TL); 4630 return Result; 4631 } 4632 4633 QualType TransformDeducedTemplateSpecializationType( 4634 TypeLocBuilder &TLB, DeducedTemplateSpecializationTypeLoc TL) { 4635 if (!UseTypeSugar) 4636 return TransformDesugared(TLB, TL); 4637 4638 QualType Result = SemaRef.Context.getDeducedTemplateSpecializationType( 4639 TL.getTypePtr()->getTemplateName(), 4640 Replacement, Replacement.isNull()); 4641 auto NewTL = TLB.push<DeducedTemplateSpecializationTypeLoc>(Result); 4642 NewTL.setNameLoc(TL.getNameLoc()); 4643 return Result; 4644 } 4645 4646 ExprResult TransformLambdaExpr(LambdaExpr *E) { 4647 // Lambdas never need to be transformed. 4648 return E; 4649 } 4650 4651 QualType Apply(TypeLoc TL) { 4652 // Create some scratch storage for the transformed type locations. 4653 // FIXME: We're just going to throw this information away. Don't build it. 4654 TypeLocBuilder TLB; 4655 TLB.reserve(TL.getFullDataSize()); 4656 return TransformType(TLB, TL); 4657 } 4658 }; 4659 4660} // namespace 4661 4662Sema::DeduceAutoResult 4663Sema::DeduceAutoType(TypeSourceInfo *Type, Expr *&Init, QualType &Result, 4664 Optional<unsigned> DependentDeductionDepth, 4665 bool IgnoreConstraints) { 4666 return DeduceAutoType(Type->getTypeLoc(), Init, Result, 4667 DependentDeductionDepth, IgnoreConstraints); 4668} 4669 4670/// Attempt to produce an informative diagostic explaining why auto deduction 4671/// failed. 4672/// \return \c true if diagnosed, \c false if not. 4673static bool diagnoseAutoDeductionFailure(Sema &S, 4674 Sema::TemplateDeductionResult TDK, 4675 TemplateDeductionInfo &Info, 4676 ArrayRef<SourceRange> Ranges) { 4677 switch (TDK) { 4678 case Sema::TDK_Inconsistent: { 4679 // Inconsistent deduction means we were deducing from an initializer list. 4680 auto D = S.Diag(Info.getLocation(), diag::err_auto_inconsistent_deduction); 4681 D << Info.FirstArg << Info.SecondArg; 4682 for (auto R : Ranges) 4683 D << R; 4684 return true; 4685 } 4686 4687 // FIXME: Are there other cases for which a custom diagnostic is more useful 4688 // than the basic "types don't match" diagnostic? 4689 4690 default: 4691 return false; 4692 } 4693} 4694 4695static Sema::DeduceAutoResult 4696CheckDeducedPlaceholderConstraints(Sema &S, const AutoType &Type, 4697 AutoTypeLoc TypeLoc, QualType Deduced) { 4698 ConstraintSatisfaction Satisfaction; 4699 ConceptDecl *Concept = Type.getTypeConstraintConcept(); 4700 TemplateArgumentListInfo TemplateArgs(TypeLoc.getLAngleLoc(), 4701 TypeLoc.getRAngleLoc()); 4702 TemplateArgs.addArgument( 4703 TemplateArgumentLoc(TemplateArgument(Deduced), 4704 S.Context.getTrivialTypeSourceInfo( 4705 Deduced, TypeLoc.getNameLoc()))); 4706 for (unsigned I = 0, C = TypeLoc.getNumArgs(); I != C; ++I) 4707 TemplateArgs.addArgument(TypeLoc.getArgLoc(I)); 4708 4709 llvm::SmallVector<TemplateArgument, 4> Converted; 4710 if (S.CheckTemplateArgumentList(Concept, SourceLocation(), TemplateArgs, 4711 /*PartialTemplateArgs=*/false, Converted)) 4712 return Sema::DAR_FailedAlreadyDiagnosed; 4713 if (S.CheckConstraintSatisfaction(Concept, {Concept->getConstraintExpr()}, 4714 Converted, TypeLoc.getLocalSourceRange(), 4715 Satisfaction)) 4716 return Sema::DAR_FailedAlreadyDiagnosed; 4717 if (!Satisfaction.IsSatisfied) { 4718 std::string Buf; 4719 llvm::raw_string_ostream OS(Buf); 4720 OS << "'" << Concept->getName(); 4721 if (TypeLoc.hasExplicitTemplateArgs()) { 4722 printTemplateArgumentList( 4723 OS, Type.getTypeConstraintArguments(), S.getPrintingPolicy(), 4724 Type.getTypeConstraintConcept()->getTemplateParameters()); 4725 } 4726 OS << "'"; 4727 OS.flush(); 4728 S.Diag(TypeLoc.getConceptNameLoc(), 4729 diag::err_placeholder_constraints_not_satisfied) 4730 << Deduced << Buf << TypeLoc.getLocalSourceRange(); 4731 S.DiagnoseUnsatisfiedConstraint(Satisfaction); 4732 return Sema::DAR_FailedAlreadyDiagnosed; 4733 } 4734 return Sema::DAR_Succeeded; 4735} 4736 4737/// Deduce the type for an auto type-specifier (C++11 [dcl.spec.auto]p6) 4738/// 4739/// Note that this is done even if the initializer is dependent. (This is 4740/// necessary to support partial ordering of templates using 'auto'.) 4741/// A dependent type will be produced when deducing from a dependent type. 4742/// 4743/// \param Type the type pattern using the auto type-specifier. 4744/// \param Init the initializer for the variable whose type is to be deduced. 4745/// \param Result if type deduction was successful, this will be set to the 4746/// deduced type. 4747/// \param DependentDeductionDepth Set if we should permit deduction in 4748/// dependent cases. This is necessary for template partial ordering with 4749/// 'auto' template parameters. The value specified is the template 4750/// parameter depth at which we should perform 'auto' deduction. 4751/// \param IgnoreConstraints Set if we should not fail if the deduced type does 4752/// not satisfy the type-constraint in the auto type. 4753Sema::DeduceAutoResult 4754Sema::DeduceAutoType(TypeLoc Type, Expr *&Init, QualType &Result, 4755 Optional<unsigned> DependentDeductionDepth, 4756 bool IgnoreConstraints) { 4757 if (Init->containsErrors()) 4758 return DAR_FailedAlreadyDiagnosed; 4759 if (Init->getType()->isNonOverloadPlaceholderType()) { 4760 ExprResult NonPlaceholder = CheckPlaceholderExpr(Init); 4761 if (NonPlaceholder.isInvalid()) 4762 return DAR_FailedAlreadyDiagnosed; 4763 Init = NonPlaceholder.get(); 4764 } 4765 4766 DependentAuto DependentResult = { 4767 /*.IsPack = */ (bool)Type.getAs<PackExpansionTypeLoc>()}; 4768 4769 if (!DependentDeductionDepth && 4770 (Type.getType()->isDependentType() || Init->isTypeDependent() || 4771 Init->containsUnexpandedParameterPack())) { 4772 Result = SubstituteDeducedTypeTransform(*this, DependentResult).Apply(Type); 4773 assert(!Result.isNull() && "substituting DependentTy can't fail")(static_cast <bool> (!Result.isNull() && "substituting DependentTy can't fail"
) ? void (0) : __assert_fail ("!Result.isNull() && \"substituting DependentTy can't fail\""
, "/build/llvm-toolchain-snapshot-14~++20211110111138+cffbfd01e37b/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 4773, __extension__ __PRETTY_FUNCTION__))
; 4774 return DAR_Succeeded; 4775 } 4776 4777 // Find the depth of template parameter to synthesize. 4778 unsigned Depth = DependentDeductionDepth.getValueOr(0); 4779 4780 // If this is a 'decltype(auto)' specifier, do the decltype dance. 4781 // Since 'decltype(auto)' can only occur at the top of the type, we 4782 // don't need to go digging for it. 4783 if (const AutoType *AT = Type.getType()->getAs<AutoType>()) { 4784 if (AT->isDecltypeAuto()) { 4785 if (isa<InitListExpr>(Init)) { 4786 Diag(Init->getBeginLoc(), diag::err_decltype_auto_initializer_list); 4787 return DAR_FailedAlreadyDiagnosed; 4788 } 4789 4790 ExprResult ER = CheckPlaceholderExpr(Init); 4791 if (ER.isInvalid()) 4792 return DAR_FailedAlreadyDiagnosed; 4793 Init = ER.get(); 4794 QualType Deduced = BuildDecltypeType(Init, Init->getBeginLoc(), false); 4795 if (Deduced.isNull()) 4796 return DAR_FailedAlreadyDiagnosed; 4797 // FIXME: Support a non-canonical deduced type for 'auto'. 4798 Deduced = Context.getCanonicalType(Deduced); 4799 if (AT->isConstrained() && !IgnoreConstraints) { 4800 auto ConstraintsResult = 4801 CheckDeducedPlaceholderConstraints(*this, *AT, 4802 Type.getContainedAutoTypeLoc(), 4803 Deduced); 4804 if (ConstraintsResult != DAR_Succeeded) 4805 return ConstraintsResult; 4806 } 4807 Result = SubstituteDeducedTypeTransform(*this, Deduced).Apply(Type); 4808 if (Result.isNull()) 4809 return DAR_FailedAlreadyDiagnosed; 4810 return DAR_Succeeded; 4811 } else if (!getLangOpts().CPlusPlus) { 4812 if (isa<InitListExpr>(Init)) { 4813 Diag(Init->getBeginLoc(), diag::err_auto_init_list_from_c); 4814 return DAR_FailedAlreadyDiagnosed; 4815 } 4816 } 4817 } 4818 4819 SourceLocation Loc = Init->getExprLoc(); 4820 4821 LocalInstantiationScope InstScope(*this); 4822 4823 // Build template<class TemplParam> void Func(FuncParam); 4824 TemplateTypeParmDecl *TemplParam = TemplateTypeParmDecl::Create( 4825 Context, nullptr, SourceLocation(), Loc, Depth, 0, nullptr, false, false, 4826 false); 4827 QualType TemplArg = QualType(TemplParam->getTypeForDecl(), 0); 4828 NamedDecl *TemplParamPtr = TemplParam; 4829 FixedSizeTemplateParameterListStorage<1, false> TemplateParamsSt( 4830 Context, Loc, Loc, TemplParamPtr, Loc, nullptr); 4831 4832 QualType FuncParam = 4833 SubstituteDeducedTypeTransform(*this, TemplArg, /*UseTypeSugar*/false) 4834 .Apply(Type); 4835 assert(!FuncParam.isNull() &&(static_cast <bool> (!FuncParam.isNull() && "substituting template parameter for 'auto' failed"
) ? void (0) : __assert_fail ("!FuncParam.isNull() && \"substituting template parameter for 'auto' failed\""
, "/build/llvm-toolchain-snapshot-14~++20211110111138+cffbfd01e37b/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 4836, __extension__ __PRETTY_FUNCTION__))
4836 "substituting template parameter for 'auto' failed")(static_cast <bool> (!FuncParam.isNull() && "substituting template parameter for 'auto' failed"
) ? void (0) : __assert_fail ("!FuncParam.isNull() && \"substituting template parameter for 'auto' failed\""
, "/build/llvm-toolchain-snapshot-14~++20211110111138+cffbfd01e37b/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 4836, __extension__ __PRETTY_FUNCTION__))
; 4837 4838 // Deduce type of TemplParam in Func(Init) 4839 SmallVector<DeducedTemplateArgument, 1> Deduced; 4840 Deduced.resize(1); 4841 4842 TemplateDeductionInfo Info(Loc, Depth); 4843 4844 // If deduction failed, don't diagnose if the initializer is dependent; it 4845 // might acquire a matching type in the instantiation. 4846 auto DeductionFailed = [&](TemplateDeductionResult TDK, 4847 ArrayRef<SourceRange> Ranges) -> DeduceAutoResult { 4848 if (Init->isTypeDependent()) { 4849 Result = 4850 SubstituteDeducedTypeTransform(*this, DependentResult).Apply(Type); 4851 assert(!Result.isNull() && "substituting DependentTy can't fail")(static_cast <bool> (!Result.isNull() && "substituting DependentTy can't fail"
) ? void (0) : __assert_fail ("!Result.isNull() && \"substituting DependentTy can't fail\""
, "/build/llvm-toolchain-snapshot-14~++20211110111138+cffbfd01e37b/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 4851, __extension__ __PRETTY_FUNCTION__))
; 4852 return DAR_Succeeded; 4853 } 4854 if (diagnoseAutoDeductionFailure(*this, TDK, Info, Ranges)) 4855 return DAR_FailedAlreadyDiagnosed; 4856 return DAR_Failed; 4857 }; 4858 4859 SmallVector<OriginalCallArg, 4> OriginalCallArgs; 4860 4861 InitListExpr *InitList = dyn_cast<InitListExpr>(Init); 4862 if (InitList) { 4863 // Notionally, we substitute std::initializer_list<T> for 'auto' and deduce 4864 // against that. Such deduction only succeeds if removing cv-qualifiers and 4865 // references results in std::initializer_list<T>. 4866 if (!Type.getType().getNonReferenceType()->getAs<AutoType>()) 4867 return DAR_Failed; 4868 4869 // Resolving a core issue: a braced-init-list containing any designators is 4870 // a non-deduced context. 4871 for (Expr *E : InitList->inits()) 4872 if (isa<DesignatedInitExpr>(E)) 4873 return DAR_Failed; 4874 4875 SourceRange DeducedFromInitRange; 4876 for (unsigned i = 0, e = InitList->getNumInits(); i < e; ++i) { 4877 Expr *Init = InitList->getInit(i); 4878 4879 if (auto TDK = DeduceTemplateArgumentsFromCallArgument( 4880 *this, TemplateParamsSt.get(), 0, TemplArg, Init, 4881 Info, Deduced, OriginalCallArgs, /*Decomposed*/ true, 4882 /*ArgIdx*/ 0, /*TDF*/ 0)) 4883 return DeductionFailed(TDK, {DeducedFromInitRange, 4884 Init->getSourceRange()}); 4885 4886 if (DeducedFromInitRange.isInvalid() && 4887 Deduced[0].getKind() != TemplateArgument::Null) 4888 DeducedFromInitRange = Init->getSourceRange(); 4889 } 4890 } else { 4891 if (!getLangOpts().CPlusPlus && Init->refersToBitField()) { 4892 Diag(Loc, diag::err_auto_bitfield); 4893 return DAR_FailedAlreadyDiagnosed; 4894 } 4895 4896 if (auto TDK = DeduceTemplateArgumentsFromCallArgument( 4897 *this, TemplateParamsSt.get(), 0, FuncParam, Init, Info, Deduced, 4898 OriginalCallArgs, /*Decomposed*/ false, /*ArgIdx*/ 0, /*TDF*/ 0)) 4899 return DeductionFailed(TDK, {}); 4900 } 4901 4902 // Could be null if somehow 'auto' appears in a non-deduced context. 4903 if (Deduced[0].getKind() != TemplateArgument::Type) 4904 return DeductionFailed(TDK_Incomplete, {}); 4905 4906 QualType DeducedType = Deduced[0].getAsType(); 4907 4908 if (InitList) { 4909 DeducedType = BuildStdInitializerList(DeducedType, Loc); 4910 if (DeducedType.isNull()) 4911 return DAR_FailedAlreadyDiagnosed; 4912 } 4913 4914 if (const auto *AT = Type.getType()->getAs<AutoType>()) { 4915 if (AT->isConstrained() && !IgnoreConstraints) { 4916 auto ConstraintsResult = 4917 CheckDeducedPlaceholderConstraints(*this, *AT, 4918 Type.getContainedAutoTypeLoc(), 4919 DeducedType); 4920 if (ConstraintsResult != DAR_Succeeded) 4921 return ConstraintsResult; 4922 } 4923 } 4924 4925 Result = SubstituteDeducedTypeTransform(*this, DeducedType).Apply(Type); 4926 if (Result.isNull()) 4927 return DAR_FailedAlreadyDiagnosed; 4928 4929 // Check that the deduced argument type is compatible with the original 4930 // argument type per C++ [temp.deduct.call]p4. 4931 QualType DeducedA = InitList ? Deduced[0].getAsType() : Result; 4932 for (const OriginalCallArg &OriginalArg : OriginalCallArgs) { 4933 assert((bool)InitList == OriginalArg.DecomposedParam &&(static_cast <bool> ((bool)InitList == OriginalArg.DecomposedParam
&& "decomposed non-init-list in auto deduction?") ? void
(0) : __assert_fail ("(bool)InitList == OriginalArg.DecomposedParam && \"decomposed non-init-list in auto deduction?\""
, "/build/llvm-toolchain-snapshot-14~++20211110111138+cffbfd01e37b/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 4934, __extension__ __PRETTY_FUNCTION__))
4934 "decomposed non-init-list in auto deduction?")(static_cast <bool> ((bool)InitList == OriginalArg.DecomposedParam
&& "decomposed non-init-list in auto deduction?") ? void
(0) : __assert_fail ("(bool)InitList == OriginalArg.DecomposedParam && \"decomposed non-init-list in auto deduction?\""
, "/build/llvm-toolchain-snapshot-14~++20211110111138+cffbfd01e37b/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 4934, __extension__ __PRETTY_FUNCTION__))
; 4935 if (auto TDK = 4936 CheckOriginalCallArgDeduction(*this, Info, OriginalArg, DeducedA)) { 4937 Result = QualType(); 4938 return DeductionFailed(TDK, {}); 4939 } 4940 } 4941 4942 return DAR_Succeeded; 4943} 4944 4945QualType Sema::SubstAutoType(QualType TypeWithAuto, 4946 QualType TypeToReplaceAuto) { 4947 if (TypeToReplaceAuto->isDependentType()) 4948 return SubstituteDeducedTypeTransform( 4949 *this, DependentAuto{ 4950 TypeToReplaceAuto->containsUnexpandedParameterPack()}) 4951 .TransformType(TypeWithAuto); 4952 return SubstituteDeducedTypeTransform(*this, TypeToReplaceAuto) 4953 .TransformType(TypeWithAuto); 4954} 4955 4956TypeSourceInfo *Sema::SubstAutoTypeSourceInfo(TypeSourceInfo *TypeWithAuto, 4957 QualType TypeToReplaceAuto) { 4958 if (TypeToReplaceAuto->isDependentType()) 4959 return SubstituteDeducedTypeTransform( 4960 *this, 4961 DependentAuto{ 4962 TypeToReplaceAuto->containsUnexpandedParameterPack()}) 4963 .TransformType(TypeWithAuto); 4964 return SubstituteDeducedTypeTransform(*this, TypeToReplaceAuto) 4965 .TransformType(TypeWithAuto); 4966} 4967 4968QualType Sema::ReplaceAutoType(QualType TypeWithAuto, 4969 QualType TypeToReplaceAuto) { 4970 return SubstituteDeducedTypeTransform(*this, TypeToReplaceAuto, 4971 /*UseTypeSugar*/ false) 4972 .TransformType(TypeWithAuto); 4973} 4974 4975TypeSourceInfo *Sema::ReplaceAutoTypeSourceInfo(TypeSourceInfo *TypeWithAuto, 4976 QualType TypeToReplaceAuto) { 4977 return SubstituteDeducedTypeTransform(*this, TypeToReplaceAuto, 4978 /*UseTypeSugar*/ false) 4979 .TransformType(TypeWithAuto); 4980} 4981 4982void Sema::DiagnoseAutoDeductionFailure(VarDecl *VDecl, Expr *Init) { 4983 if (isa<InitListExpr>(Init)) 4984 Diag(VDecl->getLocation(), 4985 VDecl->isInitCapture() 4986 ? diag::err_init_capture_deduction_failure_from_init_list 4987 : diag::err_auto_var_deduction_failure_from_init_list) 4988 << VDecl->getDeclName() << VDecl->getType() << Init->getSourceRange(); 4989 else 4990 Diag(VDecl->getLocation(), 4991 VDecl->isInitCapture() ? diag::err_init_capture_deduction_failure 4992 : diag::err_auto_var_deduction_failure) 4993 << VDecl->getDeclName() << VDecl->getType() << Init->getType() 4994 << Init->getSourceRange(); 4995} 4996 4997bool Sema::DeduceReturnType(FunctionDecl *FD, SourceLocation Loc, 4998 bool Diagnose) { 4999 assert(FD->getReturnType()->isUndeducedType())(static_cast <bool> (FD->getReturnType()->isUndeducedType
()) ? void (0) : __assert_fail ("FD->getReturnType()->isUndeducedType()"
, "/build/llvm-toolchain-snapshot-14~++20211110111138+cffbfd01e37b/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 4999, __extension__ __PRETTY_FUNCTION__))
; 5000 5001 // For a lambda's conversion operator, deduce any 'auto' or 'decltype(auto)' 5002 // within the return type from the call operator's type. 5003 if (isLambdaConversionOperator(FD)) { 5004 CXXRecordDecl *Lambda = cast<CXXMethodDecl>(FD)->getParent(); 5005 FunctionDecl *CallOp = Lambda->getLambdaCallOperator(); 5006 5007 // For a generic lambda, instantiate the call operator if needed. 5008 if (auto *Args = FD->getTemplateSpecializationArgs()) { 5009 CallOp = InstantiateFunctionDeclaration( 5010 CallOp->getDescribedFunctionTemplate(), Args, Loc); 5011 if (!CallOp || CallOp->isInvalidDecl()) 5012 return true; 5013 5014 // We might need to deduce the return type by instantiating the definition 5015 // of the operator() function. 5016 if (CallOp->getReturnType()->isUndeducedType()) { 5017 runWithSufficientStackSpace(Loc, [&] { 5018 InstantiateFunctionDefinition(Loc, CallOp); 5019 }); 5020 } 5021 } 5022 5023 if (CallOp->isInvalidDecl()) 5024 return true; 5025 assert(!CallOp->getReturnType()->isUndeducedType() &&(static_cast <bool> (!CallOp->getReturnType()->isUndeducedType
() && "failed to deduce lambda return type") ? void (
0) : __assert_fail ("!CallOp->getReturnType()->isUndeducedType() && \"failed to deduce lambda return type\""
, "/build/llvm-toolchain-snapshot-14~++20211110111138+cffbfd01e37b/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 5026, __extension__ __PRETTY_FUNCTION__))
5026 "failed to deduce lambda return type")(static_cast <bool> (!CallOp->getReturnType()->isUndeducedType
() && "failed to deduce lambda return type") ? void (
0) : __assert_fail ("!CallOp->getReturnType()->isUndeducedType() && \"failed to deduce lambda return type\""
, "/build/llvm-toolchain-snapshot-14~++20211110111138+cffbfd01e37b/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 5026, __extension__ __PRETTY_FUNCTION__))
; 5027 5028 // Build the new return type from scratch. 5029 CallingConv RetTyCC = FD->getReturnType() 5030 ->getPointeeType() 5031 ->castAs<FunctionType>() 5032 ->getCallConv(); 5033 QualType RetType = getLambdaConversionFunctionResultType( 5034 CallOp->getType()->castAs<FunctionProtoType>(), RetTyCC); 5035 if (FD->getReturnType()->getAs<PointerType>()) 5036 RetType = Context.getPointerType(RetType); 5037 else { 5038 assert(FD->getReturnType()->getAs<BlockPointerType>())(static_cast <bool> (FD->getReturnType()->getAs<
BlockPointerType>()) ? void (0) : __assert_fail ("FD->getReturnType()->getAs<BlockPointerType>()"
, "/build/llvm-toolchain-snapshot-14~++20211110111138+cffbfd01e37b/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 5038, __extension__ __PRETTY_FUNCTION__))
; 5039 RetType = Context.getBlockPointerType(RetType); 5040 } 5041 Context.adjustDeducedFunctionResultType(FD, RetType); 5042 return false; 5043 } 5044 5045 if (FD->getTemplateInstantiationPattern()) { 5046 runWithSufficientStackSpace(Loc, [&] { 5047 InstantiateFunctionDefinition(Loc, FD); 5048 }); 5049 } 5050 5051 bool StillUndeduced = FD->getReturnType()->isUndeducedType(); 5052 if (StillUndeduced && Diagnose && !FD->isInvalidDecl()) { 5053 Diag(Loc, diag::err_auto_fn_used_before_defined) << FD; 5054 Diag(FD->getLocation(), diag::note_callee_decl) << FD; 5055 } 5056 5057 return StillUndeduced; 5058} 5059 5060/// If this is a non-static member function, 5061static void 5062AddImplicitObjectParameterType(ASTContext &Context, 5063 CXXMethodDecl *Method, 5064 SmallVectorImpl<QualType> &ArgTypes) { 5065 // C++11 [temp.func.order]p3: 5066 // [...] The new parameter is of type "reference to cv A," where cv are 5067 // the cv-qualifiers of the function template (if any) and A is 5068 // the class of which the function template is a member. 5069 // 5070 // The standard doesn't say explicitly, but we pick the appropriate kind of 5071 // reference type based on [over.match.funcs]p4. 5072 QualType ArgTy = Context.getTypeDeclType(Method->getParent()); 5073 ArgTy = Context.getQualifiedType(ArgTy, Method->getMethodQualifiers()); 5074 if (Method->getRefQualifier() == RQ_RValue) 5075 ArgTy = Context.getRValueReferenceType(ArgTy); 5076 else 5077 ArgTy = Context.getLValueReferenceType(ArgTy); 5078 ArgTypes.push_back(ArgTy); 5079} 5080 5081/// Determine whether the function template \p FT1 is at least as 5082/// specialized as \p FT2. 5083static bool isAtLeastAsSpecializedAs(Sema &S, 5084 SourceLocation Loc, 5085 FunctionTemplateDecl *FT1, 5086 FunctionTemplateDecl *FT2, 5087 TemplatePartialOrderingContext TPOC, 5088 unsigned NumCallArguments1, 5089 bool Reversed) { 5090 assert(!Reversed || TPOC == TPOC_Call)(static_cast <bool> (!Reversed || TPOC == TPOC_Call) ? void
(0) : __assert_fail ("!Reversed || TPOC == TPOC_Call", "/build/llvm-toolchain-snapshot-14~++20211110111138+cffbfd01e37b/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 5090, __extension__ __PRETTY_FUNCTION__))
; 5091 5092 FunctionDecl *FD1 = FT1->getTemplatedDecl(); 5093 FunctionDecl *FD2 = FT2->getTemplatedDecl(); 5094 const FunctionProtoType *Proto1 = FD1->getType()->getAs<FunctionProtoType>(); 5095 const FunctionProtoType *Proto2 = FD2->getType()->getAs<FunctionProtoType>(); 5096 5097 assert(Proto1 && Proto2 && "Function templates must have prototypes")(static_cast <bool> (Proto1 && Proto2 &&
"Function templates must have prototypes") ? void (0) : __assert_fail
("Proto1 && Proto2 && \"Function templates must have prototypes\""
, "/build/llvm-toolchain-snapshot-14~++20211110111138+cffbfd01e37b/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 5097, __extension__ __PRETTY_FUNCTION__))
; 5098 TemplateParameterList *TemplateParams = FT2->getTemplateParameters(); 5099 SmallVector<DeducedTemplateArgument, 4> Deduced; 5100 Deduced.resize(TemplateParams->size()); 5101 5102 // C++0x [temp.deduct.partial]p3: 5103 // The types used to determine the ordering depend on the context in which 5104 // the partial ordering is done: 5105 TemplateDeductionInfo Info(Loc); 5106 SmallVector<QualType, 4> Args2; 5107 switch (TPOC) { 5108 case TPOC_Call: { 5109 // - In the context of a function call, the function parameter types are 5110 // used. 5111 CXXMethodDecl *Method1 = dyn_cast<CXXMethodDecl>(FD1); 5112 CXXMethodDecl *Method2 = dyn_cast<CXXMethodDecl>(FD2); 5113 5114 // C++11 [temp.func.order]p3: 5115 // [...] If only one of the function templates is a non-static 5116 // member, that function template is considered to have a new 5117 // first parameter inserted in its function parameter list. The 5118 // new parameter is of type "reference to cv A," where cv are 5119 // the cv-qualifiers of the function template (if any) and A is 5120 // the class of which the function template is a member. 5121 // 5122 // Note that we interpret this to mean "if one of the function 5123 // templates is a non-static member and the other is a non-member"; 5124 // otherwise, the ordering rules for static functions against non-static 5125 // functions don't make any sense. 5126 // 5127 // C++98/03 doesn't have this provision but we've extended DR532 to cover 5128 // it as wording was broken prior to it. 5129 SmallVector<QualType, 4> Args1; 5130 5131 unsigned NumComparedArguments = NumCallArguments1; 5132 5133 if (!Method2 && Method1 && !Method1->isStatic()) { 5134 // Compare 'this' from Method1 against first parameter from Method2. 5135 AddImplicitObjectParameterType(S.Context, Method1, Args1); 5136 ++NumComparedArguments; 5137 } else if (!Method1 && Method2 && !Method2->isStatic()) { 5138 // Compare 'this' from Method2 against first parameter from Method1. 5139 AddImplicitObjectParameterType(S.Context, Method2, Args2); 5140 } else if (Method1 && Method2 && Reversed) { 5141 // Compare 'this' from Method1 against second parameter from Method2 5142 // and 'this' from Method2 against second parameter from Method1. 5143 AddImplicitObjectParameterType(S.Context, Method1, Args1); 5144 AddImplicitObjectParameterType(S.Context, Method2, Args2); 5145 ++NumComparedArguments; 5146 } 5147 5148 Args1.insert(Args1.end(), Proto1->param_type_begin(), 5149 Proto1->param_type_end()); 5150 Args2.insert(Args2.end(), Proto2->param_type_begin(), 5151 Proto2->param_type_end()); 5152 5153 // C++ [temp.func.order]p5: 5154 // The presence of unused ellipsis and default arguments has no effect on 5155 // the partial ordering of function templates. 5156 if (Args1.size() > NumComparedArguments) 5157 Args1.resize(NumComparedArguments); 5158 if (Args2.size() > NumComparedArguments) 5159 Args2.resize(NumComparedArguments); 5160 if (Reversed) 5161 std::reverse(Args2.begin(), Args2.end()); 5162 if (DeduceTemplateArguments(S, TemplateParams, Args2.data(), Args2.size(), 5163 Args1.data(), Args1.size(), Info, Deduced, 5164 TDF_None, /*PartialOrdering=*/true)) 5165 return false; 5166 5167 break; 5168 } 5169 5170 case TPOC_Conversion: 5171 // - In the context of a call to a conversion operator, the return types 5172 // of the conversion function templates are used. 5173 if (DeduceTemplateArgumentsByTypeMatch( 5174 S, TemplateParams, Proto2->getReturnType(), Proto1->getReturnType(), 5175 Info, Deduced, TDF_None, 5176 /*PartialOrdering=*/true)) 5177 return false; 5178 break; 5179 5180 case TPOC_Other: 5181 // - In other contexts (14.6.6.2) the function template's function type 5182 // is used. 5183 if (DeduceTemplateArgumentsByTypeMatch(S, TemplateParams, 5184 FD2->getType(), FD1->getType(), 5185 Info, Deduced, TDF_None, 5186 /*PartialOrdering=*/true)) 5187 return false; 5188 break; 5189 } 5190 5191 // C++0x [temp.deduct.partial]p11: 5192 // In most cases, all template parameters must have values in order for 5193 // deduction to succeed, but for partial ordering purposes a template 5194 // parameter may remain without a value provided it is not used in the 5195 // types being used for partial ordering. [ Note: a template parameter used 5196 // in a non-deduced context is considered used. -end note] 5197 unsigned ArgIdx = 0, NumArgs = Deduced.size(); 5198 for (; ArgIdx != NumArgs; ++ArgIdx) 5199 if (Deduced[ArgIdx].isNull()) 5200 break; 5201 5202 // FIXME: We fail to implement [temp.deduct.type]p1 along this path. We need 5203 // to substitute the deduced arguments back into the template and check that 5204 // we get the right type. 5205 5206 if (ArgIdx == NumArgs) { 5207 // All template arguments were deduced. FT1 is at least as specialized 5208 // as FT2. 5209 return true; 5210 } 5211 5212 // Figure out which template parameters were used. 5213 llvm::SmallBitVector UsedParameters(TemplateParams->size()); 5214 switch (TPOC) { 5215 case TPOC_Call: 5216 for (unsigned I = 0, N = Args2.size(); I != N; ++I) 5217 ::MarkUsedTemplateParameters(S.Context, Args2[I], false, 5218 TemplateParams->getDepth(), 5219 UsedParameters); 5220 break; 5221 5222 case TPOC_Conversion: 5223 ::MarkUsedTemplateParameters(S.Context, Proto2->getReturnType(), false, 5224 TemplateParams->getDepth(), UsedParameters); 5225 break; 5226 5227 case TPOC_Other: 5228 ::MarkUsedTemplateParameters(S.Context, FD2->getType(), false, 5229 TemplateParams->getDepth(), 5230 UsedParameters); 5231 break; 5232 } 5233 5234 for (; ArgIdx != NumArgs; ++ArgIdx) 5235 // If this argument had no value deduced but was used in one of the types 5236 // used for partial ordering, then deduction fails. 5237 if (Deduced[ArgIdx].isNull() && UsedParameters[ArgIdx]) 5238 return false; 5239 5240 return true; 5241} 5242 5243/// Determine whether this a function template whose parameter-type-list 5244/// ends with a function parameter pack. 5245static bool isVariadicFunctionTemplate(FunctionTemplateDecl *FunTmpl) { 5246 FunctionDecl *Function = FunTmpl->getTemplatedDecl(); 5247 unsigned NumParams = Function->getNumParams(); 5248 if (NumParams == 0) 5249 return false; 5250 5251 ParmVarDecl *Last = Function->getParamDecl(NumParams - 1); 5252 if (!Last->isParameterPack()) 5253 return false; 5254 5255 // Make sure that no previous parameter is a parameter pack. 5256 while (--NumParams > 0) { 5257 if (Function->getParamDecl(NumParams - 1)->isParameterPack()) 5258 return false; 5259 } 5260 5261 return true; 5262} 5263 5264/// Returns the more specialized function template according 5265/// to the rules of function template partial ordering (C++ [temp.func.order]). 5266/// 5267/// \param FT1 the first function template 5268/// 5269/// \param FT2 the second function template 5270/// 5271/// \param TPOC the context in which we are performing partial ordering of 5272/// function templates. 5273/// 5274/// \param NumCallArguments1 The number of arguments in the call to FT1, used 5275/// only when \c TPOC is \c TPOC_Call. 5276/// 5277/// \param NumCallArguments2 The number of arguments in the call to FT2, used 5278/// only when \c TPOC is \c TPOC_Call. 5279/// 5280/// \param Reversed If \c true, exactly one of FT1 and FT2 is an overload 5281/// candidate with a reversed parameter order. In this case, the corresponding 5282/// P/A pairs between FT1 and FT2 are reversed. 5283/// 5284/// \returns the more specialized function template. If neither 5285/// template is more specialized, returns NULL. 5286FunctionTemplateDecl * 5287Sema::getMoreSpecializedTemplate(FunctionTemplateDecl *FT1, 5288 FunctionTemplateDecl *FT2, 5289 SourceLocation Loc, 5290 TemplatePartialOrderingContext TPOC, 5291 unsigned NumCallArguments1, 5292 unsigned NumCallArguments2, 5293 bool Reversed) { 5294 5295 auto JudgeByConstraints = [&] () -> FunctionTemplateDecl * { 5296 llvm::SmallVector<const Expr *, 3> AC1, AC2; 5297 FT1->getAssociatedConstraints(AC1); 5298 FT2->getAssociatedConstraints(AC2); 5299 bool AtLeastAsConstrained1, AtLeastAsConstrained2; 5300 if (IsAtLeastAsConstrained(FT1, AC1, FT2, AC2, AtLeastAsConstrained1)) 5301 return nullptr; 5302 if (IsAtLeastAsConstrained(FT2, AC2, FT1, AC1, AtLeastAsConstrained2)) 5303 return nullptr; 5304 if (AtLeastAsConstrained1 == AtLeastAsConstrained2) 5305 return nullptr; 5306 return AtLeastAsConstrained1 ? FT1 : FT2; 5307 }; 5308 5309 bool Better1 = isAtLeastAsSpecializedAs(*this, Loc, FT1, FT2, TPOC, 5310 NumCallArguments1, Reversed); 5311 bool Better2 = isAtLeastAsSpecializedAs(*this, Loc, FT2, FT1, TPOC, 5312 NumCallArguments2, Reversed); 5313 5314 if (Better1 != Better2) // We have a clear winner 5315 return Better1 ? FT1 : FT2; 5316 5317 if (!Better1 && !Better2) // Neither is better than the other 5318 return JudgeByConstraints(); 5319 5320 // FIXME: This mimics what GCC implements, but doesn't match up with the 5321 // proposed resolution for core issue 692. This area needs to be sorted out, 5322 // but for now we attempt to maintain compatibility. 5323 bool Variadic1 = isVariadicFunctionTemplate(FT1); 5324 bool Variadic2 = isVariadicFunctionTemplate(FT2); 5325 if (Variadic1 != Variadic2) 5326 return Variadic1? FT2 : FT1; 5327 5328 return JudgeByConstraints(); 5329} 5330 5331/// Determine if the two templates are equivalent. 5332static bool isSameTemplate(TemplateDecl *T1, TemplateDecl *T2) { 5333 if (T1 == T2) 5334 return true; 5335 5336 if (!T1 || !T2) 5337 return false; 5338 5339 return T1->getCanonicalDecl() == T2->getCanonicalDecl(); 5340} 5341 5342/// Retrieve the most specialized of the given function template 5343/// specializations. 5344/// 5345/// \param SpecBegin the start iterator of the function template 5346/// specializations that we will be comparing. 5347/// 5348/// \param SpecEnd the end iterator of the function template 5349/// specializations, paired with \p SpecBegin. 5350/// 5351/// \param Loc the location where the ambiguity or no-specializations 5352/// diagnostic should occur. 5353/// 5354/// \param NoneDiag partial diagnostic used to diagnose cases where there are 5355/// no matching candidates. 5356/// 5357/// \param AmbigDiag partial diagnostic used to diagnose an ambiguity, if one 5358/// occurs. 5359/// 5360/// \param CandidateDiag partial diagnostic used for each function template 5361/// specialization that is a candidate in the ambiguous ordering. One parameter 5362/// in this diagnostic should be unbound, which will correspond to the string 5363/// describing the template arguments for the function template specialization. 5364/// 5365/// \returns the most specialized function template specialization, if 5366/// found. Otherwise, returns SpecEnd. 5367UnresolvedSetIterator Sema::getMostSpecialized( 5368 UnresolvedSetIterator SpecBegin, UnresolvedSetIterator SpecEnd, 5369 TemplateSpecCandidateSet &FailedCandidates, 5370 SourceLocation Loc, const PartialDiagnostic &NoneDiag, 5371 const PartialDiagnostic &AmbigDiag, const PartialDiagnostic &CandidateDiag, 5372 bool Complain, QualType TargetType) { 5373 if (SpecBegin == SpecEnd) { 5374 if (Complain) { 5375 Diag(Loc, NoneDiag); 5376 FailedCandidates.NoteCandidates(*this, Loc); 5377 } 5378 return SpecEnd; 5379 } 5380 5381 if (SpecBegin + 1 == SpecEnd) 5382 return SpecBegin; 5383 5384 // Find the function template that is better than all of the templates it 5385 // has been compared to. 5386 UnresolvedSetIterator Best = SpecBegin; 5387 FunctionTemplateDecl *BestTemplate 5388 = cast<FunctionDecl>(*Best)->getPrimaryTemplate(); 5389 assert(BestTemplate && "Not a function template specialization?")(static_cast <bool> (BestTemplate && "Not a function template specialization?"
) ? void (0) : __assert_fail ("BestTemplate && \"Not a function template specialization?\""
, "/build/llvm-toolchain-snapshot-14~++20211110111138+cffbfd01e37b/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 5389, __extension__ __PRETTY_FUNCTION__))
; 5390 for (UnresolvedSetIterator I = SpecBegin + 1; I != SpecEnd; ++I) { 5391 FunctionTemplateDecl *Challenger 5392 = cast<FunctionDecl>(*I)->getPrimaryTemplate(); 5393 assert(Challenger && "Not a function template specialization?")(static_cast <bool> (Challenger && "Not a function template specialization?"
) ? void (0) : __assert_fail ("Challenger && \"Not a function template specialization?\""
, "/build/llvm-toolchain-snapshot-14~++20211110111138+cffbfd01e37b/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 5393, __extension__ __PRETTY_FUNCTION__))
; 5394 if (isSameTemplate(getMoreSpecializedTemplate(BestTemplate, Challenger, 5395 Loc, TPOC_Other, 0, 0), 5396 Challenger)) { 5397 Best = I; 5398 BestTemplate = Challenger; 5399 } 5400 } 5401 5402 // Make sure that the "best" function template is more specialized than all 5403 // of the others. 5404 bool Ambiguous = false; 5405 for (UnresolvedSetIterator I = SpecBegin; I != SpecEnd; ++I) { 5406 FunctionTemplateDecl *Challenger 5407 = cast<FunctionDecl>(*I)->getPrimaryTemplate(); 5408 if (I != Best && 5409 !isSameTemplate(getMoreSpecializedTemplate(BestTemplate, Challenger, 5410 Loc, TPOC_Other, 0, 0), 5411 BestTemplate)) { 5412 Ambiguous = true; 5413 break; 5414 } 5415 } 5416 5417 if (!Ambiguous) { 5418 // We found an answer. Return it. 5419 return Best; 5420 } 5421 5422 // Diagnose the ambiguity. 5423 if (Complain) { 5424 Diag(Loc, AmbigDiag); 5425 5426 // FIXME: Can we order the candidates in some sane way? 5427 for (UnresolvedSetIterator I = SpecBegin; I != SpecEnd; ++I) { 5428 PartialDiagnostic PD = CandidateDiag; 5429 const auto *FD = cast<FunctionDecl>(*I); 5430 PD << FD << getTemplateArgumentBindingsText( 5431 FD->getPrimaryTemplate()->getTemplateParameters(), 5432 *FD->getTemplateSpecializationArgs()); 5433 if (!TargetType.isNull()) 5434 HandleFunctionTypeMismatch(PD, FD->getType(), TargetType); 5435 Diag((*I)->getLocation(), PD); 5436 } 5437 } 5438 5439 return SpecEnd; 5440} 5441 5442/// Determine whether one partial specialization, P1, is at least as 5443/// specialized than another, P2. 5444/// 5445/// \tparam TemplateLikeDecl The kind of P2, which must be a 5446/// TemplateDecl or {Class,Var}TemplatePartialSpecializationDecl. 5447/// \param T1 The injected-class-name of P1 (faked for a variable template). 5448/// \param T2 The injected-class-name of P2 (faked for a variable template). 5449template<typename TemplateLikeDecl> 5450static bool isAtLeastAsSpecializedAs(Sema &S, QualType T1, QualType T2, 5451 TemplateLikeDecl *P2, 5452 TemplateDeductionInfo &Info) { 5453 // C++ [temp.class.order]p1: 5454 // For two class template partial specializations, the first is at least as 5455 // specialized as the second if, given the following rewrite to two 5456 // function templates, the first function template is at least as 5457 // specialized as the second according to the ordering rules for function 5458 // templates (14.6.6.2): 5459 // - the first function template has the same template parameters as the 5460 // first partial specialization and has a single function parameter 5461 // whose type is a class template specialization with the template 5462 // arguments of the first partial specialization, and 5463 // - the second function template has the same template parameters as the 5464 // second partial specialization and has a single function parameter 5465 // whose type is a class template specialization with the template 5466 // arguments of the second partial specialization. 5467 // 5468 // Rather than synthesize function templates, we merely perform the 5469 // equivalent partial ordering by performing deduction directly on 5470 // the template arguments of the class template partial 5471 // specializations. This computation is slightly simpler than the 5472 // general problem of function template partial ordering, because 5473 // class template partial specializations are more constrained. We 5474 // know that every template parameter is deducible from the class 5475 // template partial specialization's template arguments, for 5476 // example. 5477 SmallVector<DeducedTemplateArgument, 4> Deduced; 5478 5479 // Determine whether P1 is at least as specialized as P2. 5480 Deduced.resize(P2->getTemplateParameters()->size()); 5481 if (DeduceTemplateArgumentsByTypeMatch(S, P2->getTemplateParameters(), 5482 T2, T1, Info, Deduced, TDF_None, 5483 /*PartialOrdering=*/true)) 5484 return false; 5485 5486 SmallVector<TemplateArgument, 4> DeducedArgs(Deduced.begin(), 5487 Deduced.end()); 5488 Sema::InstantiatingTemplate Inst(S, Info.getLocation(), P2, DeducedArgs, 5489 Info); 5490 if (Inst.isInvalid()) 5491 return false; 5492 5493 auto *TST1 = T1->castAs<TemplateSpecializationType>(); 5494 bool AtLeastAsSpecialized; 5495 S.runWithSufficientStackSpace(Info.getLocation(), [&] { 5496 AtLeastAsSpecialized = !FinishTemplateArgumentDeduction( 5497 S, P2, /*IsPartialOrdering=*/true, 5498 TemplateArgumentList(TemplateArgumentList::OnStack, 5499 TST1->template_arguments()), 5500 Deduced, Info); 5501 }); 5502 return AtLeastAsSpecialized; 5503} 5504 5505/// Returns the more specialized class template partial specialization 5506/// according to the rules of partial ordering of class template partial 5507/// specializations (C++ [temp.class.order]). 5508/// 5509/// \param PS1 the first class template partial specialization 5510/// 5511/// \param PS2 the second class template partial specialization 5512/// 5513/// \returns the more specialized class template partial specialization. If 5514/// neither partial specialization is more specialized, returns NULL. 5515ClassTemplatePartialSpecializationDecl * 5516Sema::getMoreSpecializedPartialSpecialization( 5517 ClassTemplatePartialSpecializationDecl *PS1, 5518 ClassTemplatePartialSpecializationDecl *PS2, 5519 SourceLocation Loc) { 5520 QualType PT1 = PS1->getInjectedSpecializationType(); 5521 QualType PT2 = PS2->getInjectedSpecializationType(); 5522 5523 TemplateDeductionInfo Info(Loc); 5524 bool Better1 = isAtLeastAsSpecializedAs(*this, PT1, PT2, PS2, Info); 5525 bool Better2 = isAtLeastAsSpecializedAs(*this, PT2, PT1, PS1, Info); 5526 5527 if (!Better1 && !Better2) 5528 return nullptr; 5529 if (Better1 && Better2) { 5530 llvm::SmallVector<const Expr *, 3> AC1, AC2; 5531 PS1->getAssociatedConstraints(AC1); 5532 PS2->getAssociatedConstraints(AC2); 5533 bool AtLeastAsConstrained1, AtLeastAsConstrained2; 5534 if (IsAtLeastAsConstrained(PS1, AC1, PS2, AC2, AtLeastAsConstrained1)) 5535 return nullptr; 5536 if (IsAtLeastAsConstrained(PS2, AC2, PS1, AC1, AtLeastAsConstrained2)) 5537 return nullptr; 5538 if (AtLeastAsConstrained1 == AtLeastAsConstrained2) 5539 return nullptr; 5540 return AtLeastAsConstrained1 ? PS1 : PS2; 5541 } 5542 5543 return Better1 ? PS1 : PS2; 5544} 5545 5546bool Sema::isMoreSpecializedThanPrimary( 5547 ClassTemplatePartialSpecializationDecl *Spec, TemplateDeductionInfo &Info) { 5548 ClassTemplateDecl *Primary = Spec->getSpecializedTemplate(); 5549 QualType PrimaryT = Primary->getInjectedClassNameSpecialization(); 5550 QualType PartialT = Spec->getInjectedSpecializationType(); 5551 if (!isAtLeastAsSpecializedAs(*this, PartialT, PrimaryT, Primary, Info)) 5552 return false; 5553 if (!isAtLeastAsSpecializedAs(*this, PrimaryT, PartialT, Spec, Info)) 5554 return true; 5555 Info.clearSFINAEDiagnostic(); 5556 llvm::SmallVector<const Expr *, 3> PrimaryAC, SpecAC; 5557 Primary->getAssociatedConstraints(PrimaryAC); 5558 Spec->getAssociatedConstraints(SpecAC); 5559 bool AtLeastAsConstrainedPrimary, AtLeastAsConstrainedSpec; 5560 if (IsAtLeastAsConstrained(Spec, SpecAC, Primary, PrimaryAC, 5561 AtLeastAsConstrainedSpec)) 5562 return false; 5563 if (!AtLeastAsConstrainedSpec) 5564 return false; 5565 if (IsAtLeastAsConstrained(Primary, PrimaryAC, Spec, SpecAC, 5566 AtLeastAsConstrainedPrimary)) 5567 return false; 5568 return !AtLeastAsConstrainedPrimary; 5569} 5570 5571VarTemplatePartialSpecializationDecl * 5572Sema::getMoreSpecializedPartialSpecialization( 5573 VarTemplatePartialSpecializationDecl *PS1, 5574 VarTemplatePartialSpecializationDecl *PS2, SourceLocation Loc) { 5575 // Pretend the variable template specializations are class template 5576 // specializations and form a fake injected class name type for comparison. 5577 assert(PS1->getSpecializedTemplate() == PS2->getSpecializedTemplate() &&(static_cast <bool> (PS1->getSpecializedTemplate() ==
PS2->getSpecializedTemplate() && "the partial specializations being compared should specialize"
" the same template.") ? void (0) : __assert_fail ("PS1->getSpecializedTemplate() == PS2->getSpecializedTemplate() && \"the partial specializations being compared should specialize\" \" the same template.\""
, "/build/llvm-toolchain-snapshot-14~++20211110111138+cffbfd01e37b/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 5579, __extension__ __PRETTY_FUNCTION__))
5578 "the partial specializations being compared should specialize"(static_cast <bool> (PS1->getSpecializedTemplate() ==
PS2->getSpecializedTemplate() && "the partial specializations being compared should specialize"
" the same template.") ? void (0) : __assert_fail ("PS1->getSpecializedTemplate() == PS2->getSpecializedTemplate() && \"the partial specializations being compared should specialize\" \" the same template.\""
, "/build/llvm-toolchain-snapshot-14~++20211110111138+cffbfd01e37b/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 5579, __extension__ __PRETTY_FUNCTION__))
5579 " the same template.")(static_cast <bool> (PS1->getSpecializedTemplate() ==
PS2->getSpecializedTemplate() && "the partial specializations being compared should specialize"
" the same template.") ? void (0) : __assert_fail ("PS1->getSpecializedTemplate() == PS2->getSpecializedTemplate() && \"the partial specializations being compared should specialize\" \" the same template.\""
, "/build/llvm-toolchain-snapshot-14~++20211110111138+cffbfd01e37b/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 5579, __extension__ __PRETTY_FUNCTION__))
; 5580 TemplateName Name(PS1->getSpecializedTemplate()); 5581 TemplateName CanonTemplate = Context.getCanonicalTemplateName(Name); 5582 QualType PT1 = Context.getTemplateSpecializationType( 5583 CanonTemplate, PS1->getTemplateArgs().asArray()); 5584 QualType PT2 = Context.getTemplateSpecializationType( 5585 CanonTemplate, PS2->getTemplateArgs().asArray()); 5586 5587 TemplateDeductionInfo Info(Loc); 5588 bool Better1 = isAtLeastAsSpecializedAs(*this, PT1, PT2, PS2, Info); 5589 bool Better2 = isAtLeastAsSpecializedAs(*this, PT2, PT1, PS1, Info); 5590 5591 if (!Better1 && !Better2) 5592 return nullptr; 5593 if (Better1 && Better2) { 5594 llvm::SmallVector<const Expr *, 3> AC1, AC2; 5595 PS1->getAssociatedConstraints(AC1); 5596 PS2->getAssociatedConstraints(AC2); 5597 bool AtLeastAsConstrained1, AtLeastAsConstrained2; 5598 if (IsAtLeastAsConstrained(PS1, AC1, PS2, AC2, AtLeastAsConstrained1)) 5599 return nullptr; 5600 if (IsAtLeastAsConstrained(PS2, AC2, PS1, AC1, AtLeastAsConstrained2)) 5601 return nullptr; 5602 if (AtLeastAsConstrained1 == AtLeastAsConstrained2) 5603 return nullptr; 5604 return AtLeastAsConstrained1 ? PS1 : PS2; 5605 } 5606 5607 return Better1 ? PS1 : PS2; 5608} 5609 5610bool Sema::isMoreSpecializedThanPrimary( 5611 VarTemplatePartialSpecializationDecl *Spec, TemplateDeductionInfo &Info) { 5612 TemplateDecl *Primary = Spec->getSpecializedTemplate(); 5613 // FIXME: Cache the injected template arguments rather than recomputing 5614 // them for each partial specialization. 5615 SmallVector<TemplateArgument, 8> PrimaryArgs; 5616 Context.getInjectedTemplateArgs(Primary->getTemplateParameters(), 5617 PrimaryArgs); 5618 5619 TemplateName CanonTemplate = 5620 Context.getCanonicalTemplateName(TemplateName(Primary)); 5621 QualType PrimaryT = Context.getTemplateSpecializationType( 5622 CanonTemplate, PrimaryArgs); 5623 QualType PartialT = Context.getTemplateSpecializationType( 5624 CanonTemplate, Spec->getTemplateArgs().asArray()); 5625 5626 if (!isAtLeastAsSpecializedAs(*this, PartialT, PrimaryT, Primary, Info)) 5627 return false; 5628 if (!isAtLeastAsSpecializedAs(*this, PrimaryT, PartialT, Spec, Info)) 5629 return true; 5630 Info.clearSFINAEDiagnostic(); 5631 llvm::SmallVector<const Expr *, 3> PrimaryAC, SpecAC; 5632 Primary->getAssociatedConstraints(PrimaryAC); 5633 Spec->getAssociatedConstraints(SpecAC); 5634 bool AtLeastAsConstrainedPrimary, AtLeastAsConstrainedSpec; 5635 if (IsAtLeastAsConstrained(Spec, SpecAC, Primary, PrimaryAC, 5636 AtLeastAsConstrainedSpec)) 5637 return false; 5638 if (!AtLeastAsConstrainedSpec) 5639 return false; 5640 if (IsAtLeastAsConstrained(Primary, PrimaryAC, Spec, SpecAC, 5641 AtLeastAsConstrainedPrimary)) 5642 return false; 5643 return !AtLeastAsConstrainedPrimary; 5644} 5645 5646bool Sema::isTemplateTemplateParameterAtLeastAsSpecializedAs( 5647 TemplateParameterList *P, TemplateDecl *AArg, SourceLocation Loc) { 5648 // C++1z [temp.arg.template]p4: (DR 150) 5649 // A template template-parameter P is at least as specialized as a 5650 // template template-argument A if, given the following rewrite to two 5651 // function templates... 5652 5653 // Rather than synthesize function templates, we merely perform the 5654 // equivalent partial ordering by performing deduction directly on 5655 // the template parameter lists of the template template parameters. 5656 // 5657 // Given an invented class template X with the template parameter list of 5658 // A (including default arguments): 5659 TemplateName X = Context.getCanonicalTemplateName(TemplateName(AArg)); 5660 TemplateParameterList *A = AArg->getTemplateParameters(); 5661 5662 // - Each function template has a single function parameter whose type is 5663 // a specialization of X with template arguments corresponding to the 5664 // template parameters from the respective function template 5665 SmallVector<TemplateArgument, 8> AArgs; 5666 Context.getInjectedTemplateArgs(A, AArgs); 5667 5668 // Check P's arguments against A's parameter list. This will fill in default 5669 // template arguments as needed. AArgs are already correct by construction. 5670 // We can't just use CheckTemplateIdType because that will expand alias 5671 // templates. 5672 SmallVector<TemplateArgument, 4> PArgs; 5673 { 5674 SFINAETrap Trap(*this); 5675 5676 Context.getInjectedTemplateArgs(P, PArgs); 5677 TemplateArgumentListInfo PArgList(P->getLAngleLoc(), 5678 P->getRAngleLoc()); 5679 for (unsigned I = 0, N = P->size(); I != N; ++I) { 5680 // Unwrap packs that getInjectedTemplateArgs wrapped around pack 5681 // expansions, to form an "as written" argument list. 5682 TemplateArgument Arg = PArgs[I]; 5683 if (Arg.getKind() == TemplateArgument::Pack) { 5684 assert(Arg.pack_size() == 1 && Arg.pack_begin()->isPackExpansion())(static_cast <bool> (Arg.pack_size() == 1 && Arg
.pack_begin()->isPackExpansion()) ? void (0) : __assert_fail
("Arg.pack_size() == 1 && Arg.pack_begin()->isPackExpansion()"
, "/build/llvm-toolchain-snapshot-14~++20211110111138+cffbfd01e37b/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 5684, __extension__ __PRETTY_FUNCTION__))
; 5685 Arg = *Arg.pack_begin(); 5686 } 5687 PArgList.addArgument(getTrivialTemplateArgumentLoc( 5688 Arg, QualType(), P->getParam(I)->getLocation())); 5689 } 5690 PArgs.clear(); 5691 5692 // C++1z [temp.arg.template]p3: 5693 // If the rewrite produces an invalid type, then P is not at least as 5694 // specialized as A. 5695 if (CheckTemplateArgumentList(AArg, Loc, PArgList, false, PArgs) || 5696 Trap.hasErrorOccurred()) 5697 return false; 5698 } 5699 5700 QualType AType = Context.getTemplateSpecializationType(X, AArgs); 5701 QualType PType = Context.getTemplateSpecializationType(X, PArgs); 5702 5703 // ... the function template corresponding to P is at least as specialized 5704 // as the function template corresponding to A according to the partial 5705 // ordering rules for function templates. 5706 TemplateDeductionInfo Info(Loc, A->getDepth()); 5707 return isAtLeastAsSpecializedAs(*this, PType, AType, AArg, Info); 5708} 5709 5710namespace { 5711struct MarkUsedTemplateParameterVisitor : 5712 RecursiveASTVisitor<MarkUsedTemplateParameterVisitor> { 5713 llvm::SmallBitVector &Used; 5714 unsigned Depth; 5715 5716 MarkUsedTemplateParameterVisitor(llvm::SmallBitVector &Used, 5717 unsigned Depth) 5718 : Used(Used), Depth(Depth) { } 5719 5720 bool VisitTemplateTypeParmType(TemplateTypeParmType *T) { 5721 if (T->getDepth() == Depth) 5722 Used[T->getIndex()] = true; 5723 return true; 5724 } 5725 5726 bool TraverseTemplateName(TemplateName Template) { 5727 if (auto *TTP = 5728 dyn_cast<TemplateTemplateParmDecl>(Template.getAsTemplateDecl())) 5729 if (TTP->getDepth() == Depth) 5730 Used[TTP->getIndex()] = true; 5731 RecursiveASTVisitor<MarkUsedTemplateParameterVisitor>:: 5732 TraverseTemplateName(Template); 5733 return true; 5734 } 5735 5736 bool VisitDeclRefExpr(DeclRefExpr *E) { 5737 if (auto *NTTP = dyn_cast<NonTypeTemplateParmDecl>(E->getDecl())) 5738 if (NTTP->getDepth() == Depth) 5739 Used[NTTP->getIndex()] = true; 5740 return true; 5741 } 5742}; 5743} 5744 5745/// Mark the template parameters that are used by the given 5746/// expression. 5747static void 5748MarkUsedTemplateParameters(ASTContext &Ctx, 5749 const Expr *E, 5750 bool OnlyDeduced, 5751 unsigned Depth, 5752 llvm::SmallBitVector &Used) { 5753 if (!OnlyDeduced) { 5754 MarkUsedTemplateParameterVisitor(Used, Depth) 5755 .TraverseStmt(const_cast<Expr *>(E)); 5756 return; 5757 } 5758 5759 // We can deduce from a pack expansion. 5760 if (const PackExpansionExpr *Expansion = dyn_cast<PackExpansionExpr>(E)) 5761 E = Expansion->getPattern(); 5762 5763 const NonTypeTemplateParmDecl *NTTP = getDeducedParameterFromExpr(E, Depth); 5764 if (!NTTP) 5765 return; 5766 5767 if (NTTP->getDepth() == Depth) 5768 Used[NTTP->getIndex()] = true; 5769 5770 // In C++17 mode, additional arguments may be deduced from the type of a 5771 // non-type argument. 5772 if (Ctx.getLangOpts().CPlusPlus17) 5773 MarkUsedTemplateParameters(Ctx, NTTP->getType(), OnlyDeduced, Depth, Used); 5774} 5775 5776/// Mark the template parameters that are used by the given 5777/// nested name specifier. 5778static void 5779MarkUsedTemplateParameters(ASTContext &Ctx, 5780 NestedNameSpecifier *NNS, 5781 bool OnlyDeduced, 5782 unsigned Depth, 5783 llvm::SmallBitVector &Used) { 5784 if (!NNS) 5785 return; 5786 5787 MarkUsedTemplateParameters(Ctx, NNS->getPrefix(), OnlyDeduced, Depth, 5788 Used); 5789 MarkUsedTemplateParameters(Ctx, QualType(NNS->getAsType(), 0), 5790 OnlyDeduced, Depth, Used); 5791} 5792 5793/// Mark the template parameters that are used by the given 5794/// template name. 5795static void 5796MarkUsedTemplateParameters(ASTContext &Ctx,