Bug Summary

File:clang/lib/Sema/SemaTemplateDeduction.cpp
Warning:line 3666, column 31
Called C++ object pointer is null

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clang -cc1 -triple x86_64-pc-linux-gnu -analyze -disable-free -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 -mthread-model posix -mframe-pointer=none -relaxed-aliasing -fmath-errno -fno-rounding-math -masm-verbose -mconstructor-aliases -munwind-tables -fuse-init-array -target-cpu x86-64 -dwarf-column-info -debugger-tuning=gdb -ffunction-sections -fdata-sections -resource-dir /usr/lib/llvm-10/lib/clang/10.0.0 -D CLANG_VENDOR="Debian " -D _DEBUG -D _GNU_SOURCE -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D __STDC_LIMIT_MACROS -I /build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/build-llvm/tools/clang/lib/Sema -I /build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema -I /build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/include -I /build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/build-llvm/tools/clang/include -I /build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/build-llvm/include -I /build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/llvm/include -U NDEBUG -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/c++/6.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/x86_64-linux-gnu/c++/6.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/x86_64-linux-gnu/c++/6.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/c++/6.3.0/backward -internal-isystem /usr/local/include -internal-isystem /usr/lib/llvm-10/lib/clang/10.0.0/include -internal-externc-isystem /usr/include/x86_64-linux-gnu -internal-externc-isystem /include -internal-externc-isystem /usr/include -O2 -Wno-unused-parameter -Wwrite-strings -Wno-missing-field-initializers -Wno-long-long -Wno-maybe-uninitialized -Wno-comment -std=c++14 -fdeprecated-macro -fdebug-compilation-dir /build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/build-llvm/tools/clang/lib/Sema -fdebug-prefix-map=/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809=. -ferror-limit 19 -fmessage-length 0 -fvisibility-inlines-hidden -stack-protector 2 -fgnuc-version=4.2.1 -fobjc-runtime=gcc -fno-common -fdiagnostics-show-option -vectorize-loops -vectorize-slp -analyzer-output=html -analyzer-config stable-report-filename=true -faddrsig -o /tmp/scan-build-2019-12-07-102640-14763-1 -x c++ /build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp

/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/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/TemplateBase.h"
28#include "clang/AST/TemplateName.h"
29#include "clang/AST/Type.h"
30#include "clang/AST/TypeLoc.h"
31#include "clang/AST/UnresolvedSet.h"
32#include "clang/Basic/AddressSpaces.h"
33#include "clang/Basic/ExceptionSpecificationType.h"
34#include "clang/Basic/LLVM.h"
35#include "clang/Basic/LangOptions.h"
36#include "clang/Basic/PartialDiagnostic.h"
37#include "clang/Basic/SourceLocation.h"
38#include "clang/Basic/Specifiers.h"
39#include "clang/Sema/Ownership.h"
40#include "clang/Sema/Sema.h"
41#include "clang/Sema/Template.h"
42#include "llvm/ADT/APInt.h"
43#include "llvm/ADT/APSInt.h"
44#include "llvm/ADT/ArrayRef.h"
45#include "llvm/ADT/DenseMap.h"
46#include "llvm/ADT/FoldingSet.h"
47#include "llvm/ADT/Optional.h"
48#include "llvm/ADT/SmallBitVector.h"
49#include "llvm/ADT/SmallPtrSet.h"
50#include "llvm/ADT/SmallVector.h"
51#include "llvm/Support/Casting.h"
52#include "llvm/Support/Compiler.h"
53#include "llvm/Support/ErrorHandling.h"
54#include <algorithm>
55#include <cassert>
56#include <tuple>
57#include <utility>
58
59namespace clang {
60
61 /// Various flags that control template argument deduction.
62 ///
63 /// These flags can be bitwise-OR'd together.
64 enum TemplateDeductionFlags {
65 /// No template argument deduction flags, which indicates the
66 /// strictest results for template argument deduction (as used for, e.g.,
67 /// matching class template partial specializations).
68 TDF_None = 0,
69
70 /// Within template argument deduction from a function call, we are
71 /// matching with a parameter type for which the original parameter was
72 /// a reference.
73 TDF_ParamWithReferenceType = 0x1,
74
75 /// Within template argument deduction from a function call, we
76 /// are matching in a case where we ignore cv-qualifiers.
77 TDF_IgnoreQualifiers = 0x02,
78
79 /// Within template argument deduction from a function call,
80 /// we are matching in a case where we can perform template argument
81 /// deduction from a template-id of a derived class of the argument type.
82 TDF_DerivedClass = 0x04,
83
84 /// Allow non-dependent types to differ, e.g., when performing
85 /// template argument deduction from a function call where conversions
86 /// may apply.
87 TDF_SkipNonDependent = 0x08,
88
89 /// Whether we are performing template argument deduction for
90 /// parameters and arguments in a top-level template argument
91 TDF_TopLevelParameterTypeList = 0x10,
92
93 /// Within template argument deduction from overload resolution per
94 /// C++ [over.over] allow matching function types that are compatible in
95 /// terms of noreturn and default calling convention adjustments, or
96 /// similarly matching a declared template specialization against a
97 /// possible template, per C++ [temp.deduct.decl]. In either case, permit
98 /// deduction where the parameter is a function type that can be converted
99 /// to the argument type.
100 TDF_AllowCompatibleFunctionType = 0x20,
101
102 /// Within template argument deduction for a conversion function, we are
103 /// matching with an argument type for which the original argument was
104 /// a reference.
105 TDF_ArgWithReferenceType = 0x40,
106 };
107}
108
109using namespace clang;
110using namespace sema;
111
112/// Compare two APSInts, extending and switching the sign as
113/// necessary to compare their values regardless of underlying type.
114static bool hasSameExtendedValue(llvm::APSInt X, llvm::APSInt Y) {
115 if (Y.getBitWidth() > X.getBitWidth())
116 X = X.extend(Y.getBitWidth());
117 else if (Y.getBitWidth() < X.getBitWidth())
118 Y = Y.extend(X.getBitWidth());
119
120 // If there is a signedness mismatch, correct it.
121 if (X.isSigned() != Y.isSigned()) {
122 // If the signed value is negative, then the values cannot be the same.
123 if ((Y.isSigned() && Y.isNegative()) || (X.isSigned() && X.isNegative()))
124 return false;
125
126 Y.setIsSigned(true);
127 X.setIsSigned(true);
128 }
129
130 return X == Y;
131}
132
133static Sema::TemplateDeductionResult
134DeduceTemplateArguments(Sema &S,
135 TemplateParameterList *TemplateParams,
136 const TemplateArgument &Param,
137 TemplateArgument Arg,
138 TemplateDeductionInfo &Info,
139 SmallVectorImpl<DeducedTemplateArgument> &Deduced);
140
141static Sema::TemplateDeductionResult
142DeduceTemplateArgumentsByTypeMatch(Sema &S,
143 TemplateParameterList *TemplateParams,
144 QualType Param,
145 QualType Arg,
146 TemplateDeductionInfo &Info,
147 SmallVectorImpl<DeducedTemplateArgument> &
148 Deduced,
149 unsigned TDF,
150 bool PartialOrdering = false,
151 bool DeducedFromArrayBound = false);
152
153static Sema::TemplateDeductionResult
154DeduceTemplateArguments(Sema &S, TemplateParameterList *TemplateParams,
155 ArrayRef<TemplateArgument> Params,
156 ArrayRef<TemplateArgument> Args,
157 TemplateDeductionInfo &Info,
158 SmallVectorImpl<DeducedTemplateArgument> &Deduced,
159 bool NumberOfArgumentsMustMatch);
160
161static void MarkUsedTemplateParameters(ASTContext &Ctx,
162 const TemplateArgument &TemplateArg,
163 bool OnlyDeduced, unsigned Depth,
164 llvm::SmallBitVector &Used);
165
166static void MarkUsedTemplateParameters(ASTContext &Ctx, QualType T,
167 bool OnlyDeduced, unsigned Level,
168 llvm::SmallBitVector &Deduced);
169
170/// If the given expression is of a form that permits the deduction
171/// of a non-type template parameter, return the declaration of that
172/// non-type template parameter.
173static NonTypeTemplateParmDecl *
174getDeducedParameterFromExpr(TemplateDeductionInfo &Info, Expr *E) {
175 // If we are within an alias template, the expression may have undergone
176 // any number of parameter substitutions already.
177 while (true) {
178 if (ImplicitCastExpr *IC = dyn_cast<ImplicitCastExpr>(E))
179 E = IC->getSubExpr();
180 else if (ConstantExpr *CE = dyn_cast<ConstantExpr>(E))
181 E = CE->getSubExpr();
182 else if (SubstNonTypeTemplateParmExpr *Subst =
183 dyn_cast<SubstNonTypeTemplateParmExpr>(E))
184 E = Subst->getReplacement();
185 else
186 break;
187 }
188
189 if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E))
190 if (auto *NTTP = dyn_cast<NonTypeTemplateParmDecl>(DRE->getDecl()))
191 if (NTTP->getDepth() == Info.getDeducedDepth())
192 return NTTP;
193
194 return nullptr;
195}
196
197/// Determine whether two declaration pointers refer to the same
198/// declaration.
199static bool isSameDeclaration(Decl *X, Decl *Y) {
200 if (NamedDecl *NX = dyn_cast<NamedDecl>(X))
201 X = NX->getUnderlyingDecl();
202 if (NamedDecl *NY = dyn_cast<NamedDecl>(Y))
203 Y = NY->getUnderlyingDecl();
204
205 return X->getCanonicalDecl() == Y->getCanonicalDecl();
206}
207
208/// Verify that the given, deduced template arguments are compatible.
209///
210/// \returns The deduced template argument, or a NULL template argument if
211/// the deduced template arguments were incompatible.
212static DeducedTemplateArgument
213checkDeducedTemplateArguments(ASTContext &Context,
214 const DeducedTemplateArgument &X,
215 const DeducedTemplateArgument &Y) {
216 // We have no deduction for one or both of the arguments; they're compatible.
217 if (X.isNull())
218 return Y;
219 if (Y.isNull())
220 return X;
221
222 // If we have two non-type template argument values deduced for the same
223 // parameter, they must both match the type of the parameter, and thus must
224 // match each other's type. As we're only keeping one of them, we must check
225 // for that now. The exception is that if either was deduced from an array
226 // bound, the type is permitted to differ.
227 if (!X.wasDeducedFromArrayBound() && !Y.wasDeducedFromArrayBound()) {
228 QualType XType = X.getNonTypeTemplateArgumentType();
229 if (!XType.isNull()) {
230 QualType YType = Y.getNonTypeTemplateArgumentType();
231 if (YType.isNull() || !Context.hasSameType(XType, YType))
232 return DeducedTemplateArgument();
233 }
234 }
235
236 switch (X.getKind()) {
237 case TemplateArgument::Null:
238 llvm_unreachable("Non-deduced template arguments handled above")::llvm::llvm_unreachable_internal("Non-deduced template arguments handled above"
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 238)
;
239
240 case TemplateArgument::Type:
241 // If two template type arguments have the same type, they're compatible.
242 if (Y.getKind() == TemplateArgument::Type &&
243 Context.hasSameType(X.getAsType(), Y.getAsType()))
244 return X;
245
246 // If one of the two arguments was deduced from an array bound, the other
247 // supersedes it.
248 if (X.wasDeducedFromArrayBound() != Y.wasDeducedFromArrayBound())
249 return X.wasDeducedFromArrayBound() ? Y : X;
250
251 // The arguments are not compatible.
252 return DeducedTemplateArgument();
253
254 case TemplateArgument::Integral:
255 // If we deduced a constant in one case and either a dependent expression or
256 // declaration in another case, keep the integral constant.
257 // If both are integral constants with the same value, keep that value.
258 if (Y.getKind() == TemplateArgument::Expression ||
259 Y.getKind() == TemplateArgument::Declaration ||
260 (Y.getKind() == TemplateArgument::Integral &&
261 hasSameExtendedValue(X.getAsIntegral(), Y.getAsIntegral())))
262 return X.wasDeducedFromArrayBound() ? Y : X;
263
264 // All other combinations are incompatible.
265 return DeducedTemplateArgument();
266
267 case TemplateArgument::Template:
268 if (Y.getKind() == TemplateArgument::Template &&
269 Context.hasSameTemplateName(X.getAsTemplate(), Y.getAsTemplate()))
270 return X;
271
272 // All other combinations are incompatible.
273 return DeducedTemplateArgument();
274
275 case TemplateArgument::TemplateExpansion:
276 if (Y.getKind() == TemplateArgument::TemplateExpansion &&
277 Context.hasSameTemplateName(X.getAsTemplateOrTemplatePattern(),
278 Y.getAsTemplateOrTemplatePattern()))
279 return X;
280
281 // All other combinations are incompatible.
282 return DeducedTemplateArgument();
283
284 case TemplateArgument::Expression: {
285 if (Y.getKind() != TemplateArgument::Expression)
286 return checkDeducedTemplateArguments(Context, Y, X);
287
288 // Compare the expressions for equality
289 llvm::FoldingSetNodeID ID1, ID2;
290 X.getAsExpr()->Profile(ID1, Context, true);
291 Y.getAsExpr()->Profile(ID2, Context, true);
292 if (ID1 == ID2)
293 return X.wasDeducedFromArrayBound() ? Y : X;
294
295 // Differing dependent expressions are incompatible.
296 return DeducedTemplateArgument();
297 }
298
299 case TemplateArgument::Declaration:
300 assert(!X.wasDeducedFromArrayBound())((!X.wasDeducedFromArrayBound()) ? static_cast<void> (0
) : __assert_fail ("!X.wasDeducedFromArrayBound()", "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 300, __PRETTY_FUNCTION__))
;
301
302 // If we deduced a declaration and a dependent expression, keep the
303 // declaration.
304 if (Y.getKind() == TemplateArgument::Expression)
305 return X;
306
307 // If we deduced a declaration and an integral constant, keep the
308 // integral constant and whichever type did not come from an array
309 // bound.
310 if (Y.getKind() == TemplateArgument::Integral) {
311 if (Y.wasDeducedFromArrayBound())
312 return TemplateArgument(Context, Y.getAsIntegral(),
313 X.getParamTypeForDecl());
314 return Y;
315 }
316
317 // If we deduced two declarations, make sure that they refer to the
318 // same declaration.
319 if (Y.getKind() == TemplateArgument::Declaration &&
320 isSameDeclaration(X.getAsDecl(), Y.getAsDecl()))
321 return X;
322
323 // All other combinations are incompatible.
324 return DeducedTemplateArgument();
325
326 case TemplateArgument::NullPtr:
327 // If we deduced a null pointer and a dependent expression, keep the
328 // null pointer.
329 if (Y.getKind() == TemplateArgument::Expression)
330 return X;
331
332 // If we deduced a null pointer and an integral constant, keep the
333 // integral constant.
334 if (Y.getKind() == TemplateArgument::Integral)
335 return Y;
336
337 // If we deduced two null pointers, they are the same.
338 if (Y.getKind() == TemplateArgument::NullPtr)
339 return X;
340
341 // All other combinations are incompatible.
342 return DeducedTemplateArgument();
343
344 case TemplateArgument::Pack: {
345 if (Y.getKind() != TemplateArgument::Pack ||
346 X.pack_size() != Y.pack_size())
347 return DeducedTemplateArgument();
348
349 llvm::SmallVector<TemplateArgument, 8> NewPack;
350 for (TemplateArgument::pack_iterator XA = X.pack_begin(),
351 XAEnd = X.pack_end(),
352 YA = Y.pack_begin();
353 XA != XAEnd; ++XA, ++YA) {
354 TemplateArgument Merged = checkDeducedTemplateArguments(
355 Context, DeducedTemplateArgument(*XA, X.wasDeducedFromArrayBound()),
356 DeducedTemplateArgument(*YA, Y.wasDeducedFromArrayBound()));
357 if (Merged.isNull())
358 return DeducedTemplateArgument();
359 NewPack.push_back(Merged);
360 }
361
362 return DeducedTemplateArgument(
363 TemplateArgument::CreatePackCopy(Context, NewPack),
364 X.wasDeducedFromArrayBound() && Y.wasDeducedFromArrayBound());
365 }
366 }
367
368 llvm_unreachable("Invalid TemplateArgument Kind!")::llvm::llvm_unreachable_internal("Invalid TemplateArgument Kind!"
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 368)
;
369}
370
371/// Deduce the value of the given non-type template parameter
372/// as the given deduced template argument. All non-type template parameter
373/// deduction is funneled through here.
374static Sema::TemplateDeductionResult DeduceNonTypeTemplateArgument(
375 Sema &S, TemplateParameterList *TemplateParams,
376 NonTypeTemplateParmDecl *NTTP, const DeducedTemplateArgument &NewDeduced,
377 QualType ValueType, TemplateDeductionInfo &Info,
378 SmallVectorImpl<DeducedTemplateArgument> &Deduced) {
379 assert(NTTP->getDepth() == Info.getDeducedDepth() &&((NTTP->getDepth() == Info.getDeducedDepth() && "deducing non-type template argument with wrong depth"
) ? static_cast<void> (0) : __assert_fail ("NTTP->getDepth() == Info.getDeducedDepth() && \"deducing non-type template argument with wrong depth\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 380, __PRETTY_FUNCTION__))
380 "deducing non-type template argument with wrong depth")((NTTP->getDepth() == Info.getDeducedDepth() && "deducing non-type template argument with wrong depth"
) ? static_cast<void> (0) : __assert_fail ("NTTP->getDepth() == Info.getDeducedDepth() && \"deducing non-type template argument with wrong depth\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 380, __PRETTY_FUNCTION__))
;
381
382 DeducedTemplateArgument Result = checkDeducedTemplateArguments(
383 S.Context, Deduced[NTTP->getIndex()], NewDeduced);
384 if (Result.isNull()) {
385 Info.Param = NTTP;
386 Info.FirstArg = Deduced[NTTP->getIndex()];
387 Info.SecondArg = NewDeduced;
388 return Sema::TDK_Inconsistent;
389 }
390
391 Deduced[NTTP->getIndex()] = Result;
392 if (!S.getLangOpts().CPlusPlus17)
393 return Sema::TDK_Success;
394
395 if (NTTP->isExpandedParameterPack())
396 // FIXME: We may still need to deduce parts of the type here! But we
397 // don't have any way to find which slice of the type to use, and the
398 // type stored on the NTTP itself is nonsense. Perhaps the type of an
399 // expanded NTTP should be a pack expansion type?
400 return Sema::TDK_Success;
401
402 // Get the type of the parameter for deduction. If it's a (dependent) array
403 // or function type, we will not have decayed it yet, so do that now.
404 QualType ParamType = S.Context.getAdjustedParameterType(NTTP->getType());
405 if (auto *Expansion = dyn_cast<PackExpansionType>(ParamType))
406 ParamType = Expansion->getPattern();
407
408 // FIXME: It's not clear how deduction of a parameter of reference
409 // type from an argument (of non-reference type) should be performed.
410 // For now, we just remove reference types from both sides and let
411 // the final check for matching types sort out the mess.
412 return DeduceTemplateArgumentsByTypeMatch(
413 S, TemplateParams, ParamType.getNonReferenceType(),
414 ValueType.getNonReferenceType(), Info, Deduced, TDF_SkipNonDependent,
415 /*PartialOrdering=*/false,
416 /*ArrayBound=*/NewDeduced.wasDeducedFromArrayBound());
417}
418
419/// Deduce the value of the given non-type template parameter
420/// from the given integral constant.
421static Sema::TemplateDeductionResult DeduceNonTypeTemplateArgument(
422 Sema &S, TemplateParameterList *TemplateParams,
423 NonTypeTemplateParmDecl *NTTP, const llvm::APSInt &Value,
424 QualType ValueType, bool DeducedFromArrayBound, TemplateDeductionInfo &Info,
425 SmallVectorImpl<DeducedTemplateArgument> &Deduced) {
426 return DeduceNonTypeTemplateArgument(
427 S, TemplateParams, NTTP,
428 DeducedTemplateArgument(S.Context, Value, ValueType,
429 DeducedFromArrayBound),
430 ValueType, Info, Deduced);
431}
432
433/// Deduce the value of the given non-type template parameter
434/// from the given null pointer template argument type.
435static Sema::TemplateDeductionResult DeduceNullPtrTemplateArgument(
436 Sema &S, TemplateParameterList *TemplateParams,
437 NonTypeTemplateParmDecl *NTTP, QualType NullPtrType,
438 TemplateDeductionInfo &Info,
439 SmallVectorImpl<DeducedTemplateArgument> &Deduced) {
440 Expr *Value =
441 S.ImpCastExprToType(new (S.Context) CXXNullPtrLiteralExpr(
442 S.Context.NullPtrTy, NTTP->getLocation()),
443 NullPtrType, CK_NullToPointer)
444 .get();
445 return DeduceNonTypeTemplateArgument(S, TemplateParams, NTTP,
446 DeducedTemplateArgument(Value),
447 Value->getType(), Info, Deduced);
448}
449
450/// Deduce the value of the given non-type template parameter
451/// from the given type- or value-dependent expression.
452///
453/// \returns true if deduction succeeded, false otherwise.
454static Sema::TemplateDeductionResult DeduceNonTypeTemplateArgument(
455 Sema &S, TemplateParameterList *TemplateParams,
456 NonTypeTemplateParmDecl *NTTP, Expr *Value, TemplateDeductionInfo &Info,
457 SmallVectorImpl<DeducedTemplateArgument> &Deduced) {
458 return DeduceNonTypeTemplateArgument(S, TemplateParams, NTTP,
459 DeducedTemplateArgument(Value),
460 Value->getType(), Info, Deduced);
461}
462
463/// Deduce the value of the given non-type template parameter
464/// from the given declaration.
465///
466/// \returns true if deduction succeeded, false otherwise.
467static Sema::TemplateDeductionResult DeduceNonTypeTemplateArgument(
468 Sema &S, TemplateParameterList *TemplateParams,
469 NonTypeTemplateParmDecl *NTTP, ValueDecl *D, QualType T,
470 TemplateDeductionInfo &Info,
471 SmallVectorImpl<DeducedTemplateArgument> &Deduced) {
472 D = D ? cast<ValueDecl>(D->getCanonicalDecl()) : nullptr;
473 TemplateArgument New(D, T);
474 return DeduceNonTypeTemplateArgument(
475 S, TemplateParams, NTTP, DeducedTemplateArgument(New), T, Info, Deduced);
476}
477
478static Sema::TemplateDeductionResult
479DeduceTemplateArguments(Sema &S,
480 TemplateParameterList *TemplateParams,
481 TemplateName Param,
482 TemplateName Arg,
483 TemplateDeductionInfo &Info,
484 SmallVectorImpl<DeducedTemplateArgument> &Deduced) {
485 TemplateDecl *ParamDecl = Param.getAsTemplateDecl();
486 if (!ParamDecl) {
487 // The parameter type is dependent and is not a template template parameter,
488 // so there is nothing that we can deduce.
489 return Sema::TDK_Success;
490 }
491
492 if (TemplateTemplateParmDecl *TempParam
493 = dyn_cast<TemplateTemplateParmDecl>(ParamDecl)) {
494 // If we're not deducing at this depth, there's nothing to deduce.
495 if (TempParam->getDepth() != Info.getDeducedDepth())
496 return Sema::TDK_Success;
497
498 DeducedTemplateArgument NewDeduced(S.Context.getCanonicalTemplateName(Arg));
499 DeducedTemplateArgument Result = checkDeducedTemplateArguments(S.Context,
500 Deduced[TempParam->getIndex()],
501 NewDeduced);
502 if (Result.isNull()) {
503 Info.Param = TempParam;
504 Info.FirstArg = Deduced[TempParam->getIndex()];
505 Info.SecondArg = NewDeduced;
506 return Sema::TDK_Inconsistent;
507 }
508
509 Deduced[TempParam->getIndex()] = Result;
510 return Sema::TDK_Success;
511 }
512
513 // Verify that the two template names are equivalent.
514 if (S.Context.hasSameTemplateName(Param, Arg))
515 return Sema::TDK_Success;
516
517 // Mismatch of non-dependent template parameter to argument.
518 Info.FirstArg = TemplateArgument(Param);
519 Info.SecondArg = TemplateArgument(Arg);
520 return Sema::TDK_NonDeducedMismatch;
521}
522
523/// Deduce the template arguments by comparing the template parameter
524/// type (which is a template-id) with the template argument type.
525///
526/// \param S the Sema
527///
528/// \param TemplateParams the template parameters that we are deducing
529///
530/// \param Param the parameter type
531///
532/// \param Arg the argument type
533///
534/// \param Info information about the template argument deduction itself
535///
536/// \param Deduced the deduced template arguments
537///
538/// \returns the result of template argument deduction so far. Note that a
539/// "success" result means that template argument deduction has not yet failed,
540/// but it may still fail, later, for other reasons.
541static Sema::TemplateDeductionResult
542DeduceTemplateArguments(Sema &S,
543 TemplateParameterList *TemplateParams,
544 const TemplateSpecializationType *Param,
545 QualType Arg,
546 TemplateDeductionInfo &Info,
547 SmallVectorImpl<DeducedTemplateArgument> &Deduced) {
548 assert(Arg.isCanonical() && "Argument type must be canonical")((Arg.isCanonical() && "Argument type must be canonical"
) ? static_cast<void> (0) : __assert_fail ("Arg.isCanonical() && \"Argument type must be canonical\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 548, __PRETTY_FUNCTION__))
;
549
550 // Treat an injected-class-name as its underlying template-id.
551 if (auto *Injected = dyn_cast<InjectedClassNameType>(Arg))
552 Arg = Injected->getInjectedSpecializationType();
553
554 // Check whether the template argument is a dependent template-id.
555 if (const TemplateSpecializationType *SpecArg
556 = dyn_cast<TemplateSpecializationType>(Arg)) {
557 // Perform template argument deduction for the template name.
558 if (Sema::TemplateDeductionResult Result
559 = DeduceTemplateArguments(S, TemplateParams,
560 Param->getTemplateName(),
561 SpecArg->getTemplateName(),
562 Info, Deduced))
563 return Result;
564
565
566 // Perform template argument deduction on each template
567 // argument. Ignore any missing/extra arguments, since they could be
568 // filled in by default arguments.
569 return DeduceTemplateArguments(S, TemplateParams,
570 Param->template_arguments(),
571 SpecArg->template_arguments(), Info, Deduced,
572 /*NumberOfArgumentsMustMatch=*/false);
573 }
574
575 // If the argument type is a class template specialization, we
576 // perform template argument deduction using its template
577 // arguments.
578 const RecordType *RecordArg = dyn_cast<RecordType>(Arg);
579 if (!RecordArg) {
580 Info.FirstArg = TemplateArgument(QualType(Param, 0));
581 Info.SecondArg = TemplateArgument(Arg);
582 return Sema::TDK_NonDeducedMismatch;
583 }
584
585 ClassTemplateSpecializationDecl *SpecArg
586 = dyn_cast<ClassTemplateSpecializationDecl>(RecordArg->getDecl());
587 if (!SpecArg) {
588 Info.FirstArg = TemplateArgument(QualType(Param, 0));
589 Info.SecondArg = TemplateArgument(Arg);
590 return Sema::TDK_NonDeducedMismatch;
591 }
592
593 // Perform template argument deduction for the template name.
594 if (Sema::TemplateDeductionResult Result
595 = DeduceTemplateArguments(S,
596 TemplateParams,
597 Param->getTemplateName(),
598 TemplateName(SpecArg->getSpecializedTemplate()),
599 Info, Deduced))
600 return Result;
601
602 // Perform template argument deduction for the template arguments.
603 return DeduceTemplateArguments(S, TemplateParams, Param->template_arguments(),
604 SpecArg->getTemplateArgs().asArray(), Info,
605 Deduced, /*NumberOfArgumentsMustMatch=*/true);
606}
607
608/// Determines whether the given type is an opaque type that
609/// might be more qualified when instantiated.
610static bool IsPossiblyOpaquelyQualifiedType(QualType T) {
611 switch (T->getTypeClass()) {
612 case Type::TypeOfExpr:
613 case Type::TypeOf:
614 case Type::DependentName:
615 case Type::Decltype:
616 case Type::UnresolvedUsing:
617 case Type::TemplateTypeParm:
618 return true;
619
620 case Type::ConstantArray:
621 case Type::IncompleteArray:
622 case Type::VariableArray:
623 case Type::DependentSizedArray:
624 return IsPossiblyOpaquelyQualifiedType(
625 cast<ArrayType>(T)->getElementType());
626
627 default:
628 return false;
629 }
630}
631
632/// Helper function to build a TemplateParameter when we don't
633/// know its type statically.
634static TemplateParameter makeTemplateParameter(Decl *D) {
635 if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(D))
636 return TemplateParameter(TTP);
637 if (NonTypeTemplateParmDecl *NTTP = dyn_cast<NonTypeTemplateParmDecl>(D))
638 return TemplateParameter(NTTP);
639
640 return TemplateParameter(cast<TemplateTemplateParmDecl>(D));
641}
642
643/// If \p Param is an expanded parameter pack, get the number of expansions.
644static Optional<unsigned> getExpandedPackSize(NamedDecl *Param) {
645 if (auto *NTTP = dyn_cast<NonTypeTemplateParmDecl>(Param))
646 if (NTTP->isExpandedParameterPack())
647 return NTTP->getNumExpansionTypes();
648
649 if (auto *TTP = dyn_cast<TemplateTemplateParmDecl>(Param))
650 if (TTP->isExpandedParameterPack())
651 return TTP->getNumExpansionTemplateParameters();
652
653 return None;
654}
655
656/// A pack that we're currently deducing.
657struct clang::DeducedPack {
658 // The index of the pack.
659 unsigned Index;
660
661 // The old value of the pack before we started deducing it.
662 DeducedTemplateArgument Saved;
663
664 // A deferred value of this pack from an inner deduction, that couldn't be
665 // deduced because this deduction hadn't happened yet.
666 DeducedTemplateArgument DeferredDeduction;
667
668 // The new value of the pack.
669 SmallVector<DeducedTemplateArgument, 4> New;
670
671 // The outer deduction for this pack, if any.
672 DeducedPack *Outer = nullptr;
673
674 DeducedPack(unsigned Index) : Index(Index) {}
675};
676
677namespace {
678
679/// A scope in which we're performing pack deduction.
680class PackDeductionScope {
681public:
682 /// Prepare to deduce the packs named within Pattern.
683 PackDeductionScope(Sema &S, TemplateParameterList *TemplateParams,
684 SmallVectorImpl<DeducedTemplateArgument> &Deduced,
685 TemplateDeductionInfo &Info, TemplateArgument Pattern)
686 : S(S), TemplateParams(TemplateParams), Deduced(Deduced), Info(Info) {
687 unsigned NumNamedPacks = addPacks(Pattern);
688 finishConstruction(NumNamedPacks);
689 }
690
691 /// Prepare to directly deduce arguments of the parameter with index \p Index.
692 PackDeductionScope(Sema &S, TemplateParameterList *TemplateParams,
693 SmallVectorImpl<DeducedTemplateArgument> &Deduced,
694 TemplateDeductionInfo &Info, unsigned Index)
695 : S(S), TemplateParams(TemplateParams), Deduced(Deduced), Info(Info) {
696 addPack(Index);
697 finishConstruction(1);
698 }
699
700private:
701 void addPack(unsigned Index) {
702 // Save the deduced template argument for the parameter pack expanded
703 // by this pack expansion, then clear out the deduction.
704 DeducedPack Pack(Index);
705 Pack.Saved = Deduced[Index];
706 Deduced[Index] = TemplateArgument();
707
708 // FIXME: What if we encounter multiple packs with different numbers of
709 // pre-expanded expansions? (This should already have been diagnosed
710 // during substitution.)
711 if (Optional<unsigned> ExpandedPackExpansions =
712 getExpandedPackSize(TemplateParams->getParam(Index)))
713 FixedNumExpansions = ExpandedPackExpansions;
714
715 Packs.push_back(Pack);
716 }
717
718 unsigned addPacks(TemplateArgument Pattern) {
719 // Compute the set of template parameter indices that correspond to
720 // parameter packs expanded by the pack expansion.
721 llvm::SmallBitVector SawIndices(TemplateParams->size());
722
723 auto AddPack = [&](unsigned Index) {
724 if (SawIndices[Index])
725 return;
726 SawIndices[Index] = true;
727 addPack(Index);
728 };
729
730 // First look for unexpanded packs in the pattern.
731 SmallVector<UnexpandedParameterPack, 2> Unexpanded;
732 S.collectUnexpandedParameterPacks(Pattern, Unexpanded);
733 for (unsigned I = 0, N = Unexpanded.size(); I != N; ++I) {
734 unsigned Depth, Index;
735 std::tie(Depth, Index) = getDepthAndIndex(Unexpanded[I]);
736 if (Depth == Info.getDeducedDepth())
737 AddPack(Index);
738 }
739 assert(!Packs.empty() && "Pack expansion without unexpanded packs?")((!Packs.empty() && "Pack expansion without unexpanded packs?"
) ? static_cast<void> (0) : __assert_fail ("!Packs.empty() && \"Pack expansion without unexpanded packs?\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 739, __PRETTY_FUNCTION__))
;
740
741 unsigned NumNamedPacks = Packs.size();
742
743 // We can also have deduced template parameters that do not actually
744 // appear in the pattern, but can be deduced by it (the type of a non-type
745 // template parameter pack, in particular). These won't have prevented us
746 // from partially expanding the pack.
747 llvm::SmallBitVector Used(TemplateParams->size());
748 MarkUsedTemplateParameters(S.Context, Pattern, /*OnlyDeduced*/true,
749 Info.getDeducedDepth(), Used);
750 for (int Index = Used.find_first(); Index != -1;
751 Index = Used.find_next(Index))
752 if (TemplateParams->getParam(Index)->isParameterPack())
753 AddPack(Index);
754
755 return NumNamedPacks;
756 }
757
758 void finishConstruction(unsigned NumNamedPacks) {
759 // Dig out the partially-substituted pack, if there is one.
760 const TemplateArgument *PartialPackArgs = nullptr;
761 unsigned NumPartialPackArgs = 0;
762 std::pair<unsigned, unsigned> PartialPackDepthIndex(-1u, -1u);
763 if (auto *Scope = S.CurrentInstantiationScope)
764 if (auto *Partial = Scope->getPartiallySubstitutedPack(
765 &PartialPackArgs, &NumPartialPackArgs))
766 PartialPackDepthIndex = getDepthAndIndex(Partial);
767
768 // This pack expansion will have been partially or fully expanded if
769 // it only names explicitly-specified parameter packs (including the
770 // partially-substituted one, if any).
771 bool IsExpanded = true;
772 for (unsigned I = 0; I != NumNamedPacks; ++I) {
773 if (Packs[I].Index >= Info.getNumExplicitArgs()) {
774 IsExpanded = false;
775 IsPartiallyExpanded = false;
776 break;
777 }
778 if (PartialPackDepthIndex ==
779 std::make_pair(Info.getDeducedDepth(), Packs[I].Index)) {
780 IsPartiallyExpanded = true;
781 }
782 }
783
784 // Skip over the pack elements that were expanded into separate arguments.
785 // If we partially expanded, this is the number of partial arguments.
786 if (IsPartiallyExpanded)
787 PackElements += NumPartialPackArgs;
788 else if (IsExpanded)
789 PackElements += *FixedNumExpansions;
790
791 for (auto &Pack : Packs) {
792 if (Info.PendingDeducedPacks.size() > Pack.Index)
793 Pack.Outer = Info.PendingDeducedPacks[Pack.Index];
794 else
795 Info.PendingDeducedPacks.resize(Pack.Index + 1);
796 Info.PendingDeducedPacks[Pack.Index] = &Pack;
797
798 if (PartialPackDepthIndex ==
799 std::make_pair(Info.getDeducedDepth(), Pack.Index)) {
800 Pack.New.append(PartialPackArgs, PartialPackArgs + NumPartialPackArgs);
801 // We pre-populate the deduced value of the partially-substituted
802 // pack with the specified value. This is not entirely correct: the
803 // value is supposed to have been substituted, not deduced, but the
804 // cases where this is observable require an exact type match anyway.
805 //
806 // FIXME: If we could represent a "depth i, index j, pack elem k"
807 // parameter, we could substitute the partially-substituted pack
808 // everywhere and avoid this.
809 if (!IsPartiallyExpanded)
810 Deduced[Pack.Index] = Pack.New[PackElements];
811 }
812 }
813 }
814
815public:
816 ~PackDeductionScope() {
817 for (auto &Pack : Packs)
818 Info.PendingDeducedPacks[Pack.Index] = Pack.Outer;
819 }
820
821 /// Determine whether this pack has already been partially expanded into a
822 /// sequence of (prior) function parameters / template arguments.
823 bool isPartiallyExpanded() { return IsPartiallyExpanded; }
824
825 /// Determine whether this pack expansion scope has a known, fixed arity.
826 /// This happens if it involves a pack from an outer template that has
827 /// (notionally) already been expanded.
828 bool hasFixedArity() { return FixedNumExpansions.hasValue(); }
829
830 /// Determine whether the next element of the argument is still part of this
831 /// pack. This is the case unless the pack is already expanded to a fixed
832 /// length.
833 bool hasNextElement() {
834 return !FixedNumExpansions || *FixedNumExpansions > PackElements;
835 }
836
837 /// Move to deducing the next element in each pack that is being deduced.
838 void nextPackElement() {
839 // Capture the deduced template arguments for each parameter pack expanded
840 // by this pack expansion, add them to the list of arguments we've deduced
841 // for that pack, then clear out the deduced argument.
842 for (auto &Pack : Packs) {
843 DeducedTemplateArgument &DeducedArg = Deduced[Pack.Index];
844 if (!Pack.New.empty() || !DeducedArg.isNull()) {
845 while (Pack.New.size() < PackElements)
846 Pack.New.push_back(DeducedTemplateArgument());
847 if (Pack.New.size() == PackElements)
848 Pack.New.push_back(DeducedArg);
849 else
850 Pack.New[PackElements] = DeducedArg;
851 DeducedArg = Pack.New.size() > PackElements + 1
852 ? Pack.New[PackElements + 1]
853 : DeducedTemplateArgument();
854 }
855 }
856 ++PackElements;
857 }
858
859 /// Finish template argument deduction for a set of argument packs,
860 /// producing the argument packs and checking for consistency with prior
861 /// deductions.
862 Sema::TemplateDeductionResult
863 finish(bool TreatNoDeductionsAsNonDeduced = true) {
864 // Build argument packs for each of the parameter packs expanded by this
865 // pack expansion.
866 for (auto &Pack : Packs) {
867 // Put back the old value for this pack.
868 Deduced[Pack.Index] = Pack.Saved;
869
870 // If we are deducing the size of this pack even if we didn't deduce any
871 // values for it, then make sure we build a pack of the right size.
872 // FIXME: Should we always deduce the size, even if the pack appears in
873 // a non-deduced context?
874 if (!TreatNoDeductionsAsNonDeduced)
875 Pack.New.resize(PackElements);
876
877 // Build or find a new value for this pack.
878 DeducedTemplateArgument NewPack;
879 if (PackElements && Pack.New.empty()) {
880 if (Pack.DeferredDeduction.isNull()) {
881 // We were not able to deduce anything for this parameter pack
882 // (because it only appeared in non-deduced contexts), so just
883 // restore the saved argument pack.
884 continue;
885 }
886
887 NewPack = Pack.DeferredDeduction;
888 Pack.DeferredDeduction = TemplateArgument();
889 } else if (Pack.New.empty()) {
890 // If we deduced an empty argument pack, create it now.
891 NewPack = DeducedTemplateArgument(TemplateArgument::getEmptyPack());
892 } else {
893 TemplateArgument *ArgumentPack =
894 new (S.Context) TemplateArgument[Pack.New.size()];
895 std::copy(Pack.New.begin(), Pack.New.end(), ArgumentPack);
896 NewPack = DeducedTemplateArgument(
897 TemplateArgument(llvm::makeArrayRef(ArgumentPack, Pack.New.size())),
898 // FIXME: This is wrong, it's possible that some pack elements are
899 // deduced from an array bound and others are not:
900 // template<typename ...T, T ...V> void g(const T (&...p)[V]);
901 // g({1, 2, 3}, {{}, {}});
902 // ... should deduce T = {int, size_t (from array bound)}.
903 Pack.New[0].wasDeducedFromArrayBound());
904 }
905
906 // Pick where we're going to put the merged pack.
907 DeducedTemplateArgument *Loc;
908 if (Pack.Outer) {
909 if (Pack.Outer->DeferredDeduction.isNull()) {
910 // Defer checking this pack until we have a complete pack to compare
911 // it against.
912 Pack.Outer->DeferredDeduction = NewPack;
913 continue;
914 }
915 Loc = &Pack.Outer->DeferredDeduction;
916 } else {
917 Loc = &Deduced[Pack.Index];
918 }
919
920 // Check the new pack matches any previous value.
921 DeducedTemplateArgument OldPack = *Loc;
922 DeducedTemplateArgument Result =
923 checkDeducedTemplateArguments(S.Context, OldPack, NewPack);
924
925 // If we deferred a deduction of this pack, check that one now too.
926 if (!Result.isNull() && !Pack.DeferredDeduction.isNull()) {
927 OldPack = Result;
928 NewPack = Pack.DeferredDeduction;
929 Result = checkDeducedTemplateArguments(S.Context, OldPack, NewPack);
930 }
931
932 NamedDecl *Param = TemplateParams->getParam(Pack.Index);
933 if (Result.isNull()) {
934 Info.Param = makeTemplateParameter(Param);
935 Info.FirstArg = OldPack;
936 Info.SecondArg = NewPack;
937 return Sema::TDK_Inconsistent;
938 }
939
940 // If we have a pre-expanded pack and we didn't deduce enough elements
941 // for it, fail deduction.
942 if (Optional<unsigned> Expansions = getExpandedPackSize(Param)) {
943 if (*Expansions != PackElements) {
944 Info.Param = makeTemplateParameter(Param);
945 Info.FirstArg = Result;
946 return Sema::TDK_IncompletePack;
947 }
948 }
949
950 *Loc = Result;
951 }
952
953 return Sema::TDK_Success;
954 }
955
956private:
957 Sema &S;
958 TemplateParameterList *TemplateParams;
959 SmallVectorImpl<DeducedTemplateArgument> &Deduced;
960 TemplateDeductionInfo &Info;
961 unsigned PackElements = 0;
962 bool IsPartiallyExpanded = false;
963 /// The number of expansions, if we have a fully-expanded pack in this scope.
964 Optional<unsigned> FixedNumExpansions;
965
966 SmallVector<DeducedPack, 2> Packs;
967};
968
969} // namespace
970
971/// Deduce the template arguments by comparing the list of parameter
972/// types to the list of argument types, as in the parameter-type-lists of
973/// function types (C++ [temp.deduct.type]p10).
974///
975/// \param S The semantic analysis object within which we are deducing
976///
977/// \param TemplateParams The template parameters that we are deducing
978///
979/// \param Params The list of parameter types
980///
981/// \param NumParams The number of types in \c Params
982///
983/// \param Args The list of argument types
984///
985/// \param NumArgs The number of types in \c Args
986///
987/// \param Info information about the template argument deduction itself
988///
989/// \param Deduced the deduced template arguments
990///
991/// \param TDF bitwise OR of the TemplateDeductionFlags bits that describe
992/// how template argument deduction is performed.
993///
994/// \param PartialOrdering If true, we are performing template argument
995/// deduction for during partial ordering for a call
996/// (C++0x [temp.deduct.partial]).
997///
998/// \returns the result of template argument deduction so far. Note that a
999/// "success" result means that template argument deduction has not yet failed,
1000/// but it may still fail, later, for other reasons.
1001static Sema::TemplateDeductionResult
1002DeduceTemplateArguments(Sema &S,
1003 TemplateParameterList *TemplateParams,
1004 const QualType *Params, unsigned NumParams,
1005 const QualType *Args, unsigned NumArgs,
1006 TemplateDeductionInfo &Info,
1007 SmallVectorImpl<DeducedTemplateArgument> &Deduced,
1008 unsigned TDF,
1009 bool PartialOrdering = false) {
1010 // C++0x [temp.deduct.type]p10:
1011 // Similarly, if P has a form that contains (T), then each parameter type
1012 // Pi of the respective parameter-type- list of P is compared with the
1013 // corresponding parameter type Ai of the corresponding parameter-type-list
1014 // of A. [...]
1015 unsigned ArgIdx = 0, ParamIdx = 0;
1016 for (; ParamIdx != NumParams; ++ParamIdx) {
1017 // Check argument types.
1018 const PackExpansionType *Expansion
1019 = dyn_cast<PackExpansionType>(Params[ParamIdx]);
1020 if (!Expansion) {
1021 // Simple case: compare the parameter and argument types at this point.
1022
1023 // Make sure we have an argument.
1024 if (ArgIdx >= NumArgs)
1025 return Sema::TDK_MiscellaneousDeductionFailure;
1026
1027 if (isa<PackExpansionType>(Args[ArgIdx])) {
1028 // C++0x [temp.deduct.type]p22:
1029 // If the original function parameter associated with A is a function
1030 // parameter pack and the function parameter associated with P is not
1031 // a function parameter pack, then template argument deduction fails.
1032 return Sema::TDK_MiscellaneousDeductionFailure;
1033 }
1034
1035 if (Sema::TemplateDeductionResult Result
1036 = DeduceTemplateArgumentsByTypeMatch(S, TemplateParams,
1037 Params[ParamIdx], Args[ArgIdx],
1038 Info, Deduced, TDF,
1039 PartialOrdering))
1040 return Result;
1041
1042 ++ArgIdx;
1043 continue;
1044 }
1045
1046 // C++0x [temp.deduct.type]p10:
1047 // If the parameter-declaration corresponding to Pi is a function
1048 // parameter pack, then the type of its declarator- id is compared with
1049 // each remaining parameter type in the parameter-type-list of A. Each
1050 // comparison deduces template arguments for subsequent positions in the
1051 // template parameter packs expanded by the function parameter pack.
1052
1053 QualType Pattern = Expansion->getPattern();
1054 PackDeductionScope PackScope(S, TemplateParams, Deduced, Info, Pattern);
1055
1056 // A pack scope with fixed arity is not really a pack any more, so is not
1057 // a non-deduced context.
1058 if (ParamIdx + 1 == NumParams || PackScope.hasFixedArity()) {
1059 for (; ArgIdx < NumArgs && PackScope.hasNextElement(); ++ArgIdx) {
1060 // Deduce template arguments from the pattern.
1061 if (Sema::TemplateDeductionResult Result
1062 = DeduceTemplateArgumentsByTypeMatch(S, TemplateParams, Pattern,
1063 Args[ArgIdx], Info, Deduced,
1064 TDF, PartialOrdering))
1065 return Result;
1066
1067 PackScope.nextPackElement();
1068 }
1069 } else {
1070 // C++0x [temp.deduct.type]p5:
1071 // The non-deduced contexts are:
1072 // - A function parameter pack that does not occur at the end of the
1073 // parameter-declaration-clause.
1074 //
1075 // FIXME: There is no wording to say what we should do in this case. We
1076 // choose to resolve this by applying the same rule that is applied for a
1077 // function call: that is, deduce all contained packs to their
1078 // explicitly-specified values (or to <> if there is no such value).
1079 //
1080 // This is seemingly-arbitrarily different from the case of a template-id
1081 // with a non-trailing pack-expansion in its arguments, which renders the
1082 // entire template-argument-list a non-deduced context.
1083
1084 // If the parameter type contains an explicitly-specified pack that we
1085 // could not expand, skip the number of parameters notionally created
1086 // by the expansion.
1087 Optional<unsigned> NumExpansions = Expansion->getNumExpansions();
1088 if (NumExpansions && !PackScope.isPartiallyExpanded()) {
1089 for (unsigned I = 0; I != *NumExpansions && ArgIdx < NumArgs;
1090 ++I, ++ArgIdx)
1091 PackScope.nextPackElement();
1092 }
1093 }
1094
1095 // Build argument packs for each of the parameter packs expanded by this
1096 // pack expansion.
1097 if (auto Result = PackScope.finish())
1098 return Result;
1099 }
1100
1101 // Make sure we don't have any extra arguments.
1102 if (ArgIdx < NumArgs)
1103 return Sema::TDK_MiscellaneousDeductionFailure;
1104
1105 return Sema::TDK_Success;
1106}
1107
1108/// Determine whether the parameter has qualifiers that the argument
1109/// lacks. Put another way, determine whether there is no way to add
1110/// a deduced set of qualifiers to the ParamType that would result in
1111/// its qualifiers matching those of the ArgType.
1112static bool hasInconsistentOrSupersetQualifiersOf(QualType ParamType,
1113 QualType ArgType) {
1114 Qualifiers ParamQs = ParamType.getQualifiers();
1115 Qualifiers ArgQs = ArgType.getQualifiers();
1116
1117 if (ParamQs == ArgQs)
1118 return false;
1119
1120 // Mismatched (but not missing) Objective-C GC attributes.
1121 if (ParamQs.getObjCGCAttr() != ArgQs.getObjCGCAttr() &&
1122 ParamQs.hasObjCGCAttr())
1123 return true;
1124
1125 // Mismatched (but not missing) address spaces.
1126 if (ParamQs.getAddressSpace() != ArgQs.getAddressSpace() &&
1127 ParamQs.hasAddressSpace())
1128 return true;
1129
1130 // Mismatched (but not missing) Objective-C lifetime qualifiers.
1131 if (ParamQs.getObjCLifetime() != ArgQs.getObjCLifetime() &&
1132 ParamQs.hasObjCLifetime())
1133 return true;
1134
1135 // CVR qualifiers inconsistent or a superset.
1136 return (ParamQs.getCVRQualifiers() & ~ArgQs.getCVRQualifiers()) != 0;
1137}
1138
1139/// Compare types for equality with respect to possibly compatible
1140/// function types (noreturn adjustment, implicit calling conventions). If any
1141/// of parameter and argument is not a function, just perform type comparison.
1142///
1143/// \param Param the template parameter type.
1144///
1145/// \param Arg the argument type.
1146bool Sema::isSameOrCompatibleFunctionType(CanQualType Param,
1147 CanQualType Arg) {
1148 const FunctionType *ParamFunction = Param->getAs<FunctionType>(),
1149 *ArgFunction = Arg->getAs<FunctionType>();
1150
1151 // Just compare if not functions.
1152 if (!ParamFunction || !ArgFunction)
1153 return Param == Arg;
1154
1155 // Noreturn and noexcept adjustment.
1156 QualType AdjustedParam;
1157 if (IsFunctionConversion(Param, Arg, AdjustedParam))
1158 return Arg == Context.getCanonicalType(AdjustedParam);
1159
1160 // FIXME: Compatible calling conventions.
1161
1162 return Param == Arg;
1163}
1164
1165/// Get the index of the first template parameter that was originally from the
1166/// innermost template-parameter-list. This is 0 except when we concatenate
1167/// the template parameter lists of a class template and a constructor template
1168/// when forming an implicit deduction guide.
1169static unsigned getFirstInnerIndex(FunctionTemplateDecl *FTD) {
1170 auto *Guide = dyn_cast<CXXDeductionGuideDecl>(FTD->getTemplatedDecl());
1171 if (!Guide || !Guide->isImplicit())
1172 return 0;
1173 return Guide->getDeducedTemplate()->getTemplateParameters()->size();
1174}
1175
1176/// Determine whether a type denotes a forwarding reference.
1177static bool isForwardingReference(QualType Param, unsigned FirstInnerIndex) {
1178 // C++1z [temp.deduct.call]p3:
1179 // A forwarding reference is an rvalue reference to a cv-unqualified
1180 // template parameter that does not represent a template parameter of a
1181 // class template.
1182 if (auto *ParamRef = Param->getAs<RValueReferenceType>()) {
1183 if (ParamRef->getPointeeType().getQualifiers())
1184 return false;
1185 auto *TypeParm = ParamRef->getPointeeType()->getAs<TemplateTypeParmType>();
1186 return TypeParm && TypeParm->getIndex() >= FirstInnerIndex;
1187 }
1188 return false;
1189}
1190
1191/// Deduce the template arguments by comparing the parameter type and
1192/// the argument type (C++ [temp.deduct.type]).
1193///
1194/// \param S the semantic analysis object within which we are deducing
1195///
1196/// \param TemplateParams the template parameters that we are deducing
1197///
1198/// \param ParamIn the parameter type
1199///
1200/// \param ArgIn the argument type
1201///
1202/// \param Info information about the template argument deduction itself
1203///
1204/// \param Deduced the deduced template arguments
1205///
1206/// \param TDF bitwise OR of the TemplateDeductionFlags bits that describe
1207/// how template argument deduction is performed.
1208///
1209/// \param PartialOrdering Whether we're performing template argument deduction
1210/// in the context of partial ordering (C++0x [temp.deduct.partial]).
1211///
1212/// \returns the result of template argument deduction so far. Note that a
1213/// "success" result means that template argument deduction has not yet failed,
1214/// but it may still fail, later, for other reasons.
1215static Sema::TemplateDeductionResult
1216DeduceTemplateArgumentsByTypeMatch(Sema &S,
1217 TemplateParameterList *TemplateParams,
1218 QualType ParamIn, QualType ArgIn,
1219 TemplateDeductionInfo &Info,
1220 SmallVectorImpl<DeducedTemplateArgument> &Deduced,
1221 unsigned TDF,
1222 bool PartialOrdering,
1223 bool DeducedFromArrayBound) {
1224 // We only want to look at the canonical types, since typedefs and
1225 // sugar are not part of template argument deduction.
1226 QualType Param = S.Context.getCanonicalType(ParamIn);
1227 QualType Arg = S.Context.getCanonicalType(ArgIn);
1228
1229 // If the argument type is a pack expansion, look at its pattern.
1230 // This isn't explicitly called out
1231 if (const PackExpansionType *ArgExpansion
1232 = dyn_cast<PackExpansionType>(Arg))
1233 Arg = ArgExpansion->getPattern();
1234
1235 if (PartialOrdering) {
1236 // C++11 [temp.deduct.partial]p5:
1237 // Before the partial ordering is done, certain transformations are
1238 // performed on the types used for partial ordering:
1239 // - If P is a reference type, P is replaced by the type referred to.
1240 const ReferenceType *ParamRef = Param->getAs<ReferenceType>();
1241 if (ParamRef)
1242 Param = ParamRef->getPointeeType();
1243
1244 // - If A is a reference type, A is replaced by the type referred to.
1245 const ReferenceType *ArgRef = Arg->getAs<ReferenceType>();
1246 if (ArgRef)
1247 Arg = ArgRef->getPointeeType();
1248
1249 if (ParamRef && ArgRef && S.Context.hasSameUnqualifiedType(Param, Arg)) {
1250 // C++11 [temp.deduct.partial]p9:
1251 // If, for a given type, deduction succeeds in both directions (i.e.,
1252 // the types are identical after the transformations above) and both
1253 // P and A were reference types [...]:
1254 // - if [one type] was an lvalue reference and [the other type] was
1255 // not, [the other type] is not considered to be at least as
1256 // specialized as [the first type]
1257 // - if [one type] is more cv-qualified than [the other type],
1258 // [the other type] is not considered to be at least as specialized
1259 // as [the first type]
1260 // Objective-C ARC adds:
1261 // - [one type] has non-trivial lifetime, [the other type] has
1262 // __unsafe_unretained lifetime, and the types are otherwise
1263 // identical
1264 //
1265 // A is "considered to be at least as specialized" as P iff deduction
1266 // succeeds, so we model this as a deduction failure. Note that
1267 // [the first type] is P and [the other type] is A here; the standard
1268 // gets this backwards.
1269 Qualifiers ParamQuals = Param.getQualifiers();
1270 Qualifiers ArgQuals = Arg.getQualifiers();
1271 if ((ParamRef->isLValueReferenceType() &&
1272 !ArgRef->isLValueReferenceType()) ||
1273 ParamQuals.isStrictSupersetOf(ArgQuals) ||
1274 (ParamQuals.hasNonTrivialObjCLifetime() &&
1275 ArgQuals.getObjCLifetime() == Qualifiers::OCL_ExplicitNone &&
1276 ParamQuals.withoutObjCLifetime() ==
1277 ArgQuals.withoutObjCLifetime())) {
1278 Info.FirstArg = TemplateArgument(ParamIn);
1279 Info.SecondArg = TemplateArgument(ArgIn);
1280 return Sema::TDK_NonDeducedMismatch;
1281 }
1282 }
1283
1284 // C++11 [temp.deduct.partial]p7:
1285 // Remove any top-level cv-qualifiers:
1286 // - If P is a cv-qualified type, P is replaced by the cv-unqualified
1287 // version of P.
1288 Param = Param.getUnqualifiedType();
1289 // - If A is a cv-qualified type, A is replaced by the cv-unqualified
1290 // version of A.
1291 Arg = Arg.getUnqualifiedType();
1292 } else {
1293 // C++0x [temp.deduct.call]p4 bullet 1:
1294 // - If the original P is a reference type, the deduced A (i.e., the type
1295 // referred to by the reference) can be more cv-qualified than the
1296 // transformed A.
1297 if (TDF & TDF_ParamWithReferenceType) {
1298 Qualifiers Quals;
1299 QualType UnqualParam = S.Context.getUnqualifiedArrayType(Param, Quals);
1300 Quals.setCVRQualifiers(Quals.getCVRQualifiers() &
1301 Arg.getCVRQualifiers());
1302 Param = S.Context.getQualifiedType(UnqualParam, Quals);
1303 }
1304
1305 if ((TDF & TDF_TopLevelParameterTypeList) && !Param->isFunctionType()) {
1306 // C++0x [temp.deduct.type]p10:
1307 // If P and A are function types that originated from deduction when
1308 // taking the address of a function template (14.8.2.2) or when deducing
1309 // template arguments from a function declaration (14.8.2.6) and Pi and
1310 // Ai are parameters of the top-level parameter-type-list of P and A,
1311 // respectively, Pi is adjusted if it is a forwarding reference and Ai
1312 // is an lvalue reference, in
1313 // which case the type of Pi is changed to be the template parameter
1314 // type (i.e., T&& is changed to simply T). [ Note: As a result, when
1315 // Pi is T&& and Ai is X&, the adjusted Pi will be T, causing T to be
1316 // deduced as X&. - end note ]
1317 TDF &= ~TDF_TopLevelParameterTypeList;
1318 if (isForwardingReference(Param, 0) && Arg->isLValueReferenceType())
1319 Param = Param->getPointeeType();
1320 }
1321 }
1322
1323 // C++ [temp.deduct.type]p9:
1324 // A template type argument T, a template template argument TT or a
1325 // template non-type argument i can be deduced if P and A have one of
1326 // the following forms:
1327 //
1328 // T
1329 // cv-list T
1330 if (const TemplateTypeParmType *TemplateTypeParm
1331 = Param->getAs<TemplateTypeParmType>()) {
1332 // Just skip any attempts to deduce from a placeholder type or a parameter
1333 // at a different depth.
1334 if (Arg->isPlaceholderType() ||
1335 Info.getDeducedDepth() != TemplateTypeParm->getDepth())
1336 return Sema::TDK_Success;
1337
1338 unsigned Index = TemplateTypeParm->getIndex();
1339 bool RecanonicalizeArg = false;
1340
1341 // If the argument type is an array type, move the qualifiers up to the
1342 // top level, so they can be matched with the qualifiers on the parameter.
1343 if (isa<ArrayType>(Arg)) {
1344 Qualifiers Quals;
1345 Arg = S.Context.getUnqualifiedArrayType(Arg, Quals);
1346 if (Quals) {
1347 Arg = S.Context.getQualifiedType(Arg, Quals);
1348 RecanonicalizeArg = true;
1349 }
1350 }
1351
1352 // The argument type can not be less qualified than the parameter
1353 // type.
1354 if (!(TDF & TDF_IgnoreQualifiers) &&
1355 hasInconsistentOrSupersetQualifiersOf(Param, Arg)) {
1356 Info.Param = cast<TemplateTypeParmDecl>(TemplateParams->getParam(Index));
1357 Info.FirstArg = TemplateArgument(Param);
1358 Info.SecondArg = TemplateArgument(Arg);
1359 return Sema::TDK_Underqualified;
1360 }
1361
1362 // Do not match a function type with a cv-qualified type.
1363 // http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#1584
1364 if (Arg->isFunctionType() && Param.hasQualifiers()) {
1365 return Sema::TDK_NonDeducedMismatch;
1366 }
1367
1368 assert(TemplateTypeParm->getDepth() == Info.getDeducedDepth() &&((TemplateTypeParm->getDepth() == Info.getDeducedDepth() &&
"saw template type parameter with wrong depth") ? static_cast
<void> (0) : __assert_fail ("TemplateTypeParm->getDepth() == Info.getDeducedDepth() && \"saw template type parameter with wrong depth\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 1369, __PRETTY_FUNCTION__))
1369 "saw template type parameter with wrong depth")((TemplateTypeParm->getDepth() == Info.getDeducedDepth() &&
"saw template type parameter with wrong depth") ? static_cast
<void> (0) : __assert_fail ("TemplateTypeParm->getDepth() == Info.getDeducedDepth() && \"saw template type parameter with wrong depth\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 1369, __PRETTY_FUNCTION__))
;
1370 assert(Arg != S.Context.OverloadTy && "Unresolved overloaded function")((Arg != S.Context.OverloadTy && "Unresolved overloaded function"
) ? static_cast<void> (0) : __assert_fail ("Arg != S.Context.OverloadTy && \"Unresolved overloaded function\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 1370, __PRETTY_FUNCTION__))
;
1371 QualType DeducedType = Arg;
1372
1373 // Remove any qualifiers on the parameter from the deduced type.
1374 // We checked the qualifiers for consistency above.
1375 Qualifiers DeducedQs = DeducedType.getQualifiers();
1376 Qualifiers ParamQs = Param.getQualifiers();
1377 DeducedQs.removeCVRQualifiers(ParamQs.getCVRQualifiers());
1378 if (ParamQs.hasObjCGCAttr())
1379 DeducedQs.removeObjCGCAttr();
1380 if (ParamQs.hasAddressSpace())
1381 DeducedQs.removeAddressSpace();
1382 if (ParamQs.hasObjCLifetime())
1383 DeducedQs.removeObjCLifetime();
1384
1385 // Objective-C ARC:
1386 // If template deduction would produce a lifetime qualifier on a type
1387 // that is not a lifetime type, template argument deduction fails.
1388 if (ParamQs.hasObjCLifetime() && !DeducedType->isObjCLifetimeType() &&
1389 !DeducedType->isDependentType()) {
1390 Info.Param = cast<TemplateTypeParmDecl>(TemplateParams->getParam(Index));
1391 Info.FirstArg = TemplateArgument(Param);
1392 Info.SecondArg = TemplateArgument(Arg);
1393 return Sema::TDK_Underqualified;
1394 }
1395
1396 // Objective-C ARC:
1397 // If template deduction would produce an argument type with lifetime type
1398 // but no lifetime qualifier, the __strong lifetime qualifier is inferred.
1399 if (S.getLangOpts().ObjCAutoRefCount &&
1400 DeducedType->isObjCLifetimeType() &&
1401 !DeducedQs.hasObjCLifetime())
1402 DeducedQs.setObjCLifetime(Qualifiers::OCL_Strong);
1403
1404 DeducedType = S.Context.getQualifiedType(DeducedType.getUnqualifiedType(),
1405 DeducedQs);
1406
1407 if (RecanonicalizeArg)
1408 DeducedType = S.Context.getCanonicalType(DeducedType);
1409
1410 DeducedTemplateArgument NewDeduced(DeducedType, DeducedFromArrayBound);
1411 DeducedTemplateArgument Result = checkDeducedTemplateArguments(S.Context,
1412 Deduced[Index],
1413 NewDeduced);
1414 if (Result.isNull()) {
1415 Info.Param = cast<TemplateTypeParmDecl>(TemplateParams->getParam(Index));
1416 Info.FirstArg = Deduced[Index];
1417 Info.SecondArg = NewDeduced;
1418 return Sema::TDK_Inconsistent;
1419 }
1420
1421 Deduced[Index] = Result;
1422 return Sema::TDK_Success;
1423 }
1424
1425 // Set up the template argument deduction information for a failure.
1426 Info.FirstArg = TemplateArgument(ParamIn);
1427 Info.SecondArg = TemplateArgument(ArgIn);
1428
1429 // If the parameter is an already-substituted template parameter
1430 // pack, do nothing: we don't know which of its arguments to look
1431 // at, so we have to wait until all of the parameter packs in this
1432 // expansion have arguments.
1433 if (isa<SubstTemplateTypeParmPackType>(Param))
1434 return Sema::TDK_Success;
1435
1436 // Check the cv-qualifiers on the parameter and argument types.
1437 CanQualType CanParam = S.Context.getCanonicalType(Param);
1438 CanQualType CanArg = S.Context.getCanonicalType(Arg);
1439 if (!(TDF & TDF_IgnoreQualifiers)) {
1440 if (TDF & TDF_ParamWithReferenceType) {
1441 if (hasInconsistentOrSupersetQualifiersOf(Param, Arg))
1442 return Sema::TDK_NonDeducedMismatch;
1443 } else if (TDF & TDF_ArgWithReferenceType) {
1444 // C++ [temp.deduct.conv]p4:
1445 // If the original A is a reference type, A can be more cv-qualified
1446 // than the deduced A
1447 if (!Arg.getQualifiers().compatiblyIncludes(Param.getQualifiers()))
1448 return Sema::TDK_NonDeducedMismatch;
1449
1450 // Strip out all extra qualifiers from the argument to figure out the
1451 // type we're converting to, prior to the qualification conversion.
1452 Qualifiers Quals;
1453 Arg = S.Context.getUnqualifiedArrayType(Arg, Quals);
1454 Arg = S.Context.getQualifiedType(Arg, Param.getQualifiers());
1455 } else if (!IsPossiblyOpaquelyQualifiedType(Param)) {
1456 if (Param.getCVRQualifiers() != Arg.getCVRQualifiers())
1457 return Sema::TDK_NonDeducedMismatch;
1458 }
1459
1460 // If the parameter type is not dependent, there is nothing to deduce.
1461 if (!Param->isDependentType()) {
1462 if (!(TDF & TDF_SkipNonDependent)) {
1463 bool NonDeduced =
1464 (TDF & TDF_AllowCompatibleFunctionType)
1465 ? !S.isSameOrCompatibleFunctionType(CanParam, CanArg)
1466 : Param != Arg;
1467 if (NonDeduced) {
1468 return Sema::TDK_NonDeducedMismatch;
1469 }
1470 }
1471 return Sema::TDK_Success;
1472 }
1473 } else if (!Param->isDependentType()) {
1474 CanQualType ParamUnqualType = CanParam.getUnqualifiedType(),
1475 ArgUnqualType = CanArg.getUnqualifiedType();
1476 bool Success =
1477 (TDF & TDF_AllowCompatibleFunctionType)
1478 ? S.isSameOrCompatibleFunctionType(ParamUnqualType, ArgUnqualType)
1479 : ParamUnqualType == ArgUnqualType;
1480 if (Success)
1481 return Sema::TDK_Success;
1482 }
1483
1484 switch (Param->getTypeClass()) {
1485 // Non-canonical types cannot appear here.
1486#define NON_CANONICAL_TYPE(Class, Base) \
1487 case Type::Class: llvm_unreachable("deducing non-canonical type: " #Class)::llvm::llvm_unreachable_internal("deducing non-canonical type: "
#Class, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 1487)
;
1488#define TYPE(Class, Base)
1489#include "clang/AST/TypeNodes.inc"
1490
1491 case Type::TemplateTypeParm:
1492 case Type::SubstTemplateTypeParmPack:
1493 llvm_unreachable("Type nodes handled above")::llvm::llvm_unreachable_internal("Type nodes handled above",
"/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 1493)
;
1494
1495 // These types cannot be dependent, so simply check whether the types are
1496 // the same.
1497 case Type::Builtin:
1498 case Type::VariableArray:
1499 case Type::Vector:
1500 case Type::FunctionNoProto:
1501 case Type::Record:
1502 case Type::Enum:
1503 case Type::ObjCObject:
1504 case Type::ObjCInterface:
1505 case Type::ObjCObjectPointer:
1506 if (TDF & TDF_SkipNonDependent)
1507 return Sema::TDK_Success;
1508
1509 if (TDF & TDF_IgnoreQualifiers) {
1510 Param = Param.getUnqualifiedType();
1511 Arg = Arg.getUnqualifiedType();
1512 }
1513
1514 return Param == Arg? Sema::TDK_Success : Sema::TDK_NonDeducedMismatch;
1515
1516 // _Complex T [placeholder extension]
1517 case Type::Complex:
1518 if (const ComplexType *ComplexArg = Arg->getAs<ComplexType>())
1519 return DeduceTemplateArgumentsByTypeMatch(S, TemplateParams,
1520 cast<ComplexType>(Param)->getElementType(),
1521 ComplexArg->getElementType(),
1522 Info, Deduced, TDF);
1523
1524 return Sema::TDK_NonDeducedMismatch;
1525
1526 // _Atomic T [extension]
1527 case Type::Atomic:
1528 if (const AtomicType *AtomicArg = Arg->getAs<AtomicType>())
1529 return DeduceTemplateArgumentsByTypeMatch(S, TemplateParams,
1530 cast<AtomicType>(Param)->getValueType(),
1531 AtomicArg->getValueType(),
1532 Info, Deduced, TDF);
1533
1534 return Sema::TDK_NonDeducedMismatch;
1535
1536 // T *
1537 case Type::Pointer: {
1538 QualType PointeeType;
1539 if (const PointerType *PointerArg = Arg->getAs<PointerType>()) {
1540 PointeeType = PointerArg->getPointeeType();
1541 } else if (const ObjCObjectPointerType *PointerArg
1542 = Arg->getAs<ObjCObjectPointerType>()) {
1543 PointeeType = PointerArg->getPointeeType();
1544 } else {
1545 return Sema::TDK_NonDeducedMismatch;
1546 }
1547
1548 unsigned SubTDF = TDF & (TDF_IgnoreQualifiers | TDF_DerivedClass);
1549 return DeduceTemplateArgumentsByTypeMatch(S, TemplateParams,
1550 cast<PointerType>(Param)->getPointeeType(),
1551 PointeeType,
1552 Info, Deduced, SubTDF);
1553 }
1554
1555 // T &
1556 case Type::LValueReference: {
1557 const LValueReferenceType *ReferenceArg =
1558 Arg->getAs<LValueReferenceType>();
1559 if (!ReferenceArg)
1560 return Sema::TDK_NonDeducedMismatch;
1561
1562 return DeduceTemplateArgumentsByTypeMatch(S, TemplateParams,
1563 cast<LValueReferenceType>(Param)->getPointeeType(),
1564 ReferenceArg->getPointeeType(), Info, Deduced, 0);
1565 }
1566
1567 // T && [C++0x]
1568 case Type::RValueReference: {
1569 const RValueReferenceType *ReferenceArg =
1570 Arg->getAs<RValueReferenceType>();
1571 if (!ReferenceArg)
1572 return Sema::TDK_NonDeducedMismatch;
1573
1574 return DeduceTemplateArgumentsByTypeMatch(S, TemplateParams,
1575 cast<RValueReferenceType>(Param)->getPointeeType(),
1576 ReferenceArg->getPointeeType(),
1577 Info, Deduced, 0);
1578 }
1579
1580 // T [] (implied, but not stated explicitly)
1581 case Type::IncompleteArray: {
1582 const IncompleteArrayType *IncompleteArrayArg =
1583 S.Context.getAsIncompleteArrayType(Arg);
1584 if (!IncompleteArrayArg)
1585 return Sema::TDK_NonDeducedMismatch;
1586
1587 unsigned SubTDF = TDF & TDF_IgnoreQualifiers;
1588 return DeduceTemplateArgumentsByTypeMatch(S, TemplateParams,
1589 S.Context.getAsIncompleteArrayType(Param)->getElementType(),
1590 IncompleteArrayArg->getElementType(),
1591 Info, Deduced, SubTDF);
1592 }
1593
1594 // T [integer-constant]
1595 case Type::ConstantArray: {
1596 const ConstantArrayType *ConstantArrayArg =
1597 S.Context.getAsConstantArrayType(Arg);
1598 if (!ConstantArrayArg)
1599 return Sema::TDK_NonDeducedMismatch;
1600
1601 const ConstantArrayType *ConstantArrayParm =
1602 S.Context.getAsConstantArrayType(Param);
1603 if (ConstantArrayArg->getSize() != ConstantArrayParm->getSize())
1604 return Sema::TDK_NonDeducedMismatch;
1605
1606 unsigned SubTDF = TDF & TDF_IgnoreQualifiers;
1607 return DeduceTemplateArgumentsByTypeMatch(S, TemplateParams,
1608 ConstantArrayParm->getElementType(),
1609 ConstantArrayArg->getElementType(),
1610 Info, Deduced, SubTDF);
1611 }
1612
1613 // type [i]
1614 case Type::DependentSizedArray: {
1615 const ArrayType *ArrayArg = S.Context.getAsArrayType(Arg);
1616 if (!ArrayArg)
1617 return Sema::TDK_NonDeducedMismatch;
1618
1619 unsigned SubTDF = TDF & TDF_IgnoreQualifiers;
1620
1621 // Check the element type of the arrays
1622 const DependentSizedArrayType *DependentArrayParm
1623 = S.Context.getAsDependentSizedArrayType(Param);
1624 if (Sema::TemplateDeductionResult Result
1625 = DeduceTemplateArgumentsByTypeMatch(S, TemplateParams,
1626 DependentArrayParm->getElementType(),
1627 ArrayArg->getElementType(),
1628 Info, Deduced, SubTDF))
1629 return Result;
1630
1631 // Determine the array bound is something we can deduce.
1632 NonTypeTemplateParmDecl *NTTP
1633 = getDeducedParameterFromExpr(Info, DependentArrayParm->getSizeExpr());
1634 if (!NTTP)
1635 return Sema::TDK_Success;
1636
1637 // We can perform template argument deduction for the given non-type
1638 // template parameter.
1639 assert(NTTP->getDepth() == Info.getDeducedDepth() &&((NTTP->getDepth() == Info.getDeducedDepth() && "saw non-type template parameter with wrong depth"
) ? static_cast<void> (0) : __assert_fail ("NTTP->getDepth() == Info.getDeducedDepth() && \"saw non-type template parameter with wrong depth\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 1640, __PRETTY_FUNCTION__))
1640 "saw non-type template parameter with wrong depth")((NTTP->getDepth() == Info.getDeducedDepth() && "saw non-type template parameter with wrong depth"
) ? static_cast<void> (0) : __assert_fail ("NTTP->getDepth() == Info.getDeducedDepth() && \"saw non-type template parameter with wrong depth\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 1640, __PRETTY_FUNCTION__))
;
1641 if (const ConstantArrayType *ConstantArrayArg
1642 = dyn_cast<ConstantArrayType>(ArrayArg)) {
1643 llvm::APSInt Size(ConstantArrayArg->getSize());
1644 return DeduceNonTypeTemplateArgument(S, TemplateParams, NTTP, Size,
1645 S.Context.getSizeType(),
1646 /*ArrayBound=*/true,
1647 Info, Deduced);
1648 }
1649 if (const DependentSizedArrayType *DependentArrayArg
1650 = dyn_cast<DependentSizedArrayType>(ArrayArg))
1651 if (DependentArrayArg->getSizeExpr())
1652 return DeduceNonTypeTemplateArgument(S, TemplateParams, NTTP,
1653 DependentArrayArg->getSizeExpr(),
1654 Info, Deduced);
1655
1656 // Incomplete type does not match a dependently-sized array type
1657 return Sema::TDK_NonDeducedMismatch;
1658 }
1659
1660 // type(*)(T)
1661 // T(*)()
1662 // T(*)(T)
1663 case Type::FunctionProto: {
1664 unsigned SubTDF = TDF & TDF_TopLevelParameterTypeList;
1665 const FunctionProtoType *FunctionProtoArg =
1666 dyn_cast<FunctionProtoType>(Arg);
1667 if (!FunctionProtoArg)
1668 return Sema::TDK_NonDeducedMismatch;
1669
1670 const FunctionProtoType *FunctionProtoParam =
1671 cast<FunctionProtoType>(Param);
1672
1673 if (FunctionProtoParam->getMethodQuals()
1674 != FunctionProtoArg->getMethodQuals() ||
1675 FunctionProtoParam->getRefQualifier()
1676 != FunctionProtoArg->getRefQualifier() ||
1677 FunctionProtoParam->isVariadic() != FunctionProtoArg->isVariadic())
1678 return Sema::TDK_NonDeducedMismatch;
1679
1680 // Check return types.
1681 if (auto Result = DeduceTemplateArgumentsByTypeMatch(
1682 S, TemplateParams, FunctionProtoParam->getReturnType(),
1683 FunctionProtoArg->getReturnType(), Info, Deduced, 0))
1684 return Result;
1685
1686 // Check parameter types.
1687 if (auto Result = DeduceTemplateArguments(
1688 S, TemplateParams, FunctionProtoParam->param_type_begin(),
1689 FunctionProtoParam->getNumParams(),
1690 FunctionProtoArg->param_type_begin(),
1691 FunctionProtoArg->getNumParams(), Info, Deduced, SubTDF))
1692 return Result;
1693
1694 if (TDF & TDF_AllowCompatibleFunctionType)
1695 return Sema::TDK_Success;
1696
1697 // FIXME: Per core-2016/10/1019 (no corresponding core issue yet), permit
1698 // deducing through the noexcept-specifier if it's part of the canonical
1699 // type. libstdc++ relies on this.
1700 Expr *NoexceptExpr = FunctionProtoParam->getNoexceptExpr();
1701 if (NonTypeTemplateParmDecl *NTTP =
1702 NoexceptExpr ? getDeducedParameterFromExpr(Info, NoexceptExpr)
1703 : nullptr) {
1704 assert(NTTP->getDepth() == Info.getDeducedDepth() &&((NTTP->getDepth() == Info.getDeducedDepth() && "saw non-type template parameter with wrong depth"
) ? static_cast<void> (0) : __assert_fail ("NTTP->getDepth() == Info.getDeducedDepth() && \"saw non-type template parameter with wrong depth\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 1705, __PRETTY_FUNCTION__))
1705 "saw non-type template parameter with wrong depth")((NTTP->getDepth() == Info.getDeducedDepth() && "saw non-type template parameter with wrong depth"
) ? static_cast<void> (0) : __assert_fail ("NTTP->getDepth() == Info.getDeducedDepth() && \"saw non-type template parameter with wrong depth\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 1705, __PRETTY_FUNCTION__))
;
1706
1707 llvm::APSInt Noexcept(1);
1708 switch (FunctionProtoArg->canThrow()) {
1709 case CT_Cannot:
1710 Noexcept = 1;
1711 LLVM_FALLTHROUGH[[gnu::fallthrough]];
1712
1713 case CT_Can:
1714 // We give E in noexcept(E) the "deduced from array bound" treatment.
1715 // FIXME: Should we?
1716 return DeduceNonTypeTemplateArgument(
1717 S, TemplateParams, NTTP, Noexcept, S.Context.BoolTy,
1718 /*ArrayBound*/true, Info, Deduced);
1719
1720 case CT_Dependent:
1721 if (Expr *ArgNoexceptExpr = FunctionProtoArg->getNoexceptExpr())
1722 return DeduceNonTypeTemplateArgument(
1723 S, TemplateParams, NTTP, ArgNoexceptExpr, Info, Deduced);
1724 // Can't deduce anything from throw(T...).
1725 break;
1726 }
1727 }
1728 // FIXME: Detect non-deduced exception specification mismatches?
1729 //
1730 // Careful about [temp.deduct.call] and [temp.deduct.conv], which allow
1731 // top-level differences in noexcept-specifications.
1732
1733 return Sema::TDK_Success;
1734 }
1735
1736 case Type::InjectedClassName:
1737 // Treat a template's injected-class-name as if the template
1738 // specialization type had been used.
1739 Param = cast<InjectedClassNameType>(Param)
1740 ->getInjectedSpecializationType();
1741 assert(isa<TemplateSpecializationType>(Param) &&((isa<TemplateSpecializationType>(Param) && "injected class name is not a template specialization type"
) ? static_cast<void> (0) : __assert_fail ("isa<TemplateSpecializationType>(Param) && \"injected class name is not a template specialization type\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 1742, __PRETTY_FUNCTION__))
1742 "injected class name is not a template specialization type")((isa<TemplateSpecializationType>(Param) && "injected class name is not a template specialization type"
) ? static_cast<void> (0) : __assert_fail ("isa<TemplateSpecializationType>(Param) && \"injected class name is not a template specialization type\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 1742, __PRETTY_FUNCTION__))
;
1743 LLVM_FALLTHROUGH[[gnu::fallthrough]];
1744
1745 // template-name<T> (where template-name refers to a class template)
1746 // template-name<i>
1747 // TT<T>
1748 // TT<i>
1749 // TT<>
1750 case Type::TemplateSpecialization: {
1751 const TemplateSpecializationType *SpecParam =
1752 cast<TemplateSpecializationType>(Param);
1753
1754 // When Arg cannot be a derived class, we can just try to deduce template
1755 // arguments from the template-id.
1756 const RecordType *RecordT = Arg->getAs<RecordType>();
1757 if (!(TDF & TDF_DerivedClass) || !RecordT)
1758 return DeduceTemplateArguments(S, TemplateParams, SpecParam, Arg, Info,
1759 Deduced);
1760
1761 SmallVector<DeducedTemplateArgument, 8> DeducedOrig(Deduced.begin(),
1762 Deduced.end());
1763
1764 Sema::TemplateDeductionResult Result = DeduceTemplateArguments(
1765 S, TemplateParams, SpecParam, Arg, Info, Deduced);
1766
1767 if (Result == Sema::TDK_Success)
1768 return Result;
1769
1770 // We cannot inspect base classes as part of deduction when the type
1771 // is incomplete, so either instantiate any templates necessary to
1772 // complete the type, or skip over it if it cannot be completed.
1773 if (!S.isCompleteType(Info.getLocation(), Arg))
1774 return Result;
1775
1776 // C++14 [temp.deduct.call] p4b3:
1777 // If P is a class and P has the form simple-template-id, then the
1778 // transformed A can be a derived class of the deduced A. Likewise if
1779 // P is a pointer to a class of the form simple-template-id, the
1780 // transformed A can be a pointer to a derived class pointed to by the
1781 // deduced A.
1782 //
1783 // These alternatives are considered only if type deduction would
1784 // otherwise fail. If they yield more than one possible deduced A, the
1785 // type deduction fails.
1786
1787 // Reset the incorrectly deduced argument from above.
1788 Deduced = DeducedOrig;
1789
1790 // Use data recursion to crawl through the list of base classes.
1791 // Visited contains the set of nodes we have already visited, while
1792 // ToVisit is our stack of records that we still need to visit.
1793 llvm::SmallPtrSet<const RecordType *, 8> Visited;
1794 SmallVector<const RecordType *, 8> ToVisit;
1795 ToVisit.push_back(RecordT);
1796 bool Successful = false;
1797 SmallVector<DeducedTemplateArgument, 8> SuccessfulDeduced;
1798 while (!ToVisit.empty()) {
1799 // Retrieve the next class in the inheritance hierarchy.
1800 const RecordType *NextT = ToVisit.pop_back_val();
1801
1802 // If we have already seen this type, skip it.
1803 if (!Visited.insert(NextT).second)
1804 continue;
1805
1806 // If this is a base class, try to perform template argument
1807 // deduction from it.
1808 if (NextT != RecordT) {
1809 TemplateDeductionInfo BaseInfo(Info.getLocation());
1810 Sema::TemplateDeductionResult BaseResult =
1811 DeduceTemplateArguments(S, TemplateParams, SpecParam,
1812 QualType(NextT, 0), BaseInfo, Deduced);
1813
1814 // If template argument deduction for this base was successful,
1815 // note that we had some success. Otherwise, ignore any deductions
1816 // from this base class.
1817 if (BaseResult == Sema::TDK_Success) {
1818 // If we've already seen some success, then deduction fails due to
1819 // an ambiguity (temp.deduct.call p5).
1820 if (Successful)
1821 return Sema::TDK_MiscellaneousDeductionFailure;
1822
1823 Successful = true;
1824 std::swap(SuccessfulDeduced, Deduced);
1825
1826 Info.Param = BaseInfo.Param;
1827 Info.FirstArg = BaseInfo.FirstArg;
1828 Info.SecondArg = BaseInfo.SecondArg;
1829 }
1830
1831 Deduced = DeducedOrig;
1832 }
1833
1834 // Visit base classes
1835 CXXRecordDecl *Next = cast<CXXRecordDecl>(NextT->getDecl());
1836 for (const auto &Base : Next->bases()) {
1837 assert(Base.getType()->isRecordType() &&((Base.getType()->isRecordType() && "Base class that isn't a record?"
) ? static_cast<void> (0) : __assert_fail ("Base.getType()->isRecordType() && \"Base class that isn't a record?\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 1838, __PRETTY_FUNCTION__))
1838 "Base class that isn't a record?")((Base.getType()->isRecordType() && "Base class that isn't a record?"
) ? static_cast<void> (0) : __assert_fail ("Base.getType()->isRecordType() && \"Base class that isn't a record?\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 1838, __PRETTY_FUNCTION__))
;
1839 ToVisit.push_back(Base.getType()->getAs<RecordType>());
1840 }
1841 }
1842
1843 if (Successful) {
1844 std::swap(SuccessfulDeduced, Deduced);
1845 return Sema::TDK_Success;
1846 }
1847
1848 return Result;
1849 }
1850
1851 // T type::*
1852 // T T::*
1853 // T (type::*)()
1854 // type (T::*)()
1855 // type (type::*)(T)
1856 // type (T::*)(T)
1857 // T (type::*)(T)
1858 // T (T::*)()
1859 // T (T::*)(T)
1860 case Type::MemberPointer: {
1861 const MemberPointerType *MemPtrParam = cast<MemberPointerType>(Param);
1862 const MemberPointerType *MemPtrArg = dyn_cast<MemberPointerType>(Arg);
1863 if (!MemPtrArg)
1864 return Sema::TDK_NonDeducedMismatch;
1865
1866 QualType ParamPointeeType = MemPtrParam->getPointeeType();
1867 if (ParamPointeeType->isFunctionType())
1868 S.adjustMemberFunctionCC(ParamPointeeType, /*IsStatic=*/true,
1869 /*IsCtorOrDtor=*/false, Info.getLocation());
1870 QualType ArgPointeeType = MemPtrArg->getPointeeType();
1871 if (ArgPointeeType->isFunctionType())
1872 S.adjustMemberFunctionCC(ArgPointeeType, /*IsStatic=*/true,
1873 /*IsCtorOrDtor=*/false, Info.getLocation());
1874
1875 if (Sema::TemplateDeductionResult Result
1876 = DeduceTemplateArgumentsByTypeMatch(S, TemplateParams,
1877 ParamPointeeType,
1878 ArgPointeeType,
1879 Info, Deduced,
1880 TDF & TDF_IgnoreQualifiers))
1881 return Result;
1882
1883 return DeduceTemplateArgumentsByTypeMatch(S, TemplateParams,
1884 QualType(MemPtrParam->getClass(), 0),
1885 QualType(MemPtrArg->getClass(), 0),
1886 Info, Deduced,
1887 TDF & TDF_IgnoreQualifiers);
1888 }
1889
1890 // (clang extension)
1891 //
1892 // type(^)(T)
1893 // T(^)()
1894 // T(^)(T)
1895 case Type::BlockPointer: {
1896 const BlockPointerType *BlockPtrParam = cast<BlockPointerType>(Param);
1897 const BlockPointerType *BlockPtrArg = dyn_cast<BlockPointerType>(Arg);
1898
1899 if (!BlockPtrArg)
1900 return Sema::TDK_NonDeducedMismatch;
1901
1902 return DeduceTemplateArgumentsByTypeMatch(S, TemplateParams,
1903 BlockPtrParam->getPointeeType(),
1904 BlockPtrArg->getPointeeType(),
1905 Info, Deduced, 0);
1906 }
1907
1908 // (clang extension)
1909 //
1910 // T __attribute__(((ext_vector_type(<integral constant>))))
1911 case Type::ExtVector: {
1912 const ExtVectorType *VectorParam = cast<ExtVectorType>(Param);
1913 if (const ExtVectorType *VectorArg = dyn_cast<ExtVectorType>(Arg)) {
1914 // Make sure that the vectors have the same number of elements.
1915 if (VectorParam->getNumElements() != VectorArg->getNumElements())
1916 return Sema::TDK_NonDeducedMismatch;
1917
1918 // Perform deduction on the element types.
1919 return DeduceTemplateArgumentsByTypeMatch(S, TemplateParams,
1920 VectorParam->getElementType(),
1921 VectorArg->getElementType(),
1922 Info, Deduced, TDF);
1923 }
1924
1925 if (const DependentSizedExtVectorType *VectorArg
1926 = dyn_cast<DependentSizedExtVectorType>(Arg)) {
1927 // We can't check the number of elements, since the argument has a
1928 // dependent number of elements. This can only occur during partial
1929 // ordering.
1930
1931 // Perform deduction on the element types.
1932 return DeduceTemplateArgumentsByTypeMatch(S, TemplateParams,
1933 VectorParam->getElementType(),
1934 VectorArg->getElementType(),
1935 Info, Deduced, TDF);
1936 }
1937
1938 return Sema::TDK_NonDeducedMismatch;
1939 }
1940
1941 case Type::DependentVector: {
1942 const auto *VectorParam = cast<DependentVectorType>(Param);
1943
1944 if (const auto *VectorArg = dyn_cast<VectorType>(Arg)) {
1945 // Perform deduction on the element types.
1946 if (Sema::TemplateDeductionResult Result =
1947 DeduceTemplateArgumentsByTypeMatch(
1948 S, TemplateParams, VectorParam->getElementType(),
1949 VectorArg->getElementType(), Info, Deduced, TDF))
1950 return Result;
1951
1952 // Perform deduction on the vector size, if we can.
1953 NonTypeTemplateParmDecl *NTTP =
1954 getDeducedParameterFromExpr(Info, VectorParam->getSizeExpr());
1955 if (!NTTP)
1956 return Sema::TDK_Success;
1957
1958 llvm::APSInt ArgSize(S.Context.getTypeSize(S.Context.IntTy), false);
1959 ArgSize = VectorArg->getNumElements();
1960 // Note that we use the "array bound" rules here; just like in that
1961 // case, we don't have any particular type for the vector size, but
1962 // we can provide one if necessary.
1963 return DeduceNonTypeTemplateArgument(S, TemplateParams, NTTP, ArgSize,
1964 S.Context.UnsignedIntTy, true,
1965 Info, Deduced);
1966 }
1967
1968 if (const auto *VectorArg = dyn_cast<DependentVectorType>(Arg)) {
1969 // Perform deduction on the element types.
1970 if (Sema::TemplateDeductionResult Result =
1971 DeduceTemplateArgumentsByTypeMatch(
1972 S, TemplateParams, VectorParam->getElementType(),
1973 VectorArg->getElementType(), Info, Deduced, TDF))
1974 return Result;
1975
1976 // Perform deduction on the vector size, if we can.
1977 NonTypeTemplateParmDecl *NTTP = getDeducedParameterFromExpr(
1978 Info, VectorParam->getSizeExpr());
1979 if (!NTTP)
1980 return Sema::TDK_Success;
1981
1982 return DeduceNonTypeTemplateArgument(
1983 S, TemplateParams, NTTP, VectorArg->getSizeExpr(), Info, Deduced);
1984 }
1985
1986 return Sema::TDK_NonDeducedMismatch;
1987 }
1988
1989 // (clang extension)
1990 //
1991 // T __attribute__(((ext_vector_type(N))))
1992 case Type::DependentSizedExtVector: {
1993 const DependentSizedExtVectorType *VectorParam
1994 = cast<DependentSizedExtVectorType>(Param);
1995
1996 if (const ExtVectorType *VectorArg = dyn_cast<ExtVectorType>(Arg)) {
1997 // Perform deduction on the element types.
1998 if (Sema::TemplateDeductionResult Result
1999 = DeduceTemplateArgumentsByTypeMatch(S, TemplateParams,
2000 VectorParam->getElementType(),
2001 VectorArg->getElementType(),
2002 Info, Deduced, TDF))
2003 return Result;
2004
2005 // Perform deduction on the vector size, if we can.
2006 NonTypeTemplateParmDecl *NTTP
2007 = getDeducedParameterFromExpr(Info, VectorParam->getSizeExpr());
2008 if (!NTTP)
2009 return Sema::TDK_Success;
2010
2011 llvm::APSInt ArgSize(S.Context.getTypeSize(S.Context.IntTy), false);
2012 ArgSize = VectorArg->getNumElements();
2013 // Note that we use the "array bound" rules here; just like in that
2014 // case, we don't have any particular type for the vector size, but
2015 // we can provide one if necessary.
2016 return DeduceNonTypeTemplateArgument(S, TemplateParams, NTTP, ArgSize,
2017 S.Context.IntTy, true, Info,
2018 Deduced);
2019 }
2020
2021 if (const DependentSizedExtVectorType *VectorArg
2022 = dyn_cast<DependentSizedExtVectorType>(Arg)) {
2023 // Perform deduction on the element types.
2024 if (Sema::TemplateDeductionResult Result
2025 = DeduceTemplateArgumentsByTypeMatch(S, TemplateParams,
2026 VectorParam->getElementType(),
2027 VectorArg->getElementType(),
2028 Info, Deduced, TDF))
2029 return Result;
2030
2031 // Perform deduction on the vector size, if we can.
2032 NonTypeTemplateParmDecl *NTTP
2033 = getDeducedParameterFromExpr(Info, VectorParam->getSizeExpr());
2034 if (!NTTP)
2035 return Sema::TDK_Success;
2036
2037 return DeduceNonTypeTemplateArgument(S, TemplateParams, NTTP,
2038 VectorArg->getSizeExpr(),
2039 Info, Deduced);
2040 }
2041
2042 return Sema::TDK_NonDeducedMismatch;
2043 }
2044
2045 // (clang extension)
2046 //
2047 // T __attribute__(((address_space(N))))
2048 case Type::DependentAddressSpace: {
2049 const DependentAddressSpaceType *AddressSpaceParam =
2050 cast<DependentAddressSpaceType>(Param);
2051
2052 if (const DependentAddressSpaceType *AddressSpaceArg =
2053 dyn_cast<DependentAddressSpaceType>(Arg)) {
2054 // Perform deduction on the pointer type.
2055 if (Sema::TemplateDeductionResult Result =
2056 DeduceTemplateArgumentsByTypeMatch(
2057 S, TemplateParams, AddressSpaceParam->getPointeeType(),
2058 AddressSpaceArg->getPointeeType(), Info, Deduced, TDF))
2059 return Result;
2060
2061 // Perform deduction on the address space, if we can.
2062 NonTypeTemplateParmDecl *NTTP = getDeducedParameterFromExpr(
2063 Info, AddressSpaceParam->getAddrSpaceExpr());
2064 if (!NTTP)
2065 return Sema::TDK_Success;
2066
2067 return DeduceNonTypeTemplateArgument(
2068 S, TemplateParams, NTTP, AddressSpaceArg->getAddrSpaceExpr(), Info,
2069 Deduced);
2070 }
2071
2072 if (isTargetAddressSpace(Arg.getAddressSpace())) {
2073 llvm::APSInt ArgAddressSpace(S.Context.getTypeSize(S.Context.IntTy),
2074 false);
2075 ArgAddressSpace = toTargetAddressSpace(Arg.getAddressSpace());
2076
2077 // Perform deduction on the pointer types.
2078 if (Sema::TemplateDeductionResult Result =
2079 DeduceTemplateArgumentsByTypeMatch(
2080 S, TemplateParams, AddressSpaceParam->getPointeeType(),
2081 S.Context.removeAddrSpaceQualType(Arg), Info, Deduced, TDF))
2082 return Result;
2083
2084 // Perform deduction on the address space, if we can.
2085 NonTypeTemplateParmDecl *NTTP = getDeducedParameterFromExpr(
2086 Info, AddressSpaceParam->getAddrSpaceExpr());
2087 if (!NTTP)
2088 return Sema::TDK_Success;
2089
2090 return DeduceNonTypeTemplateArgument(S, TemplateParams, NTTP,
2091 ArgAddressSpace, S.Context.IntTy,
2092 true, Info, Deduced);
2093 }
2094
2095 return Sema::TDK_NonDeducedMismatch;
2096 }
2097
2098 case Type::TypeOfExpr:
2099 case Type::TypeOf:
2100 case Type::DependentName:
2101 case Type::UnresolvedUsing:
2102 case Type::Decltype:
2103 case Type::UnaryTransform:
2104 case Type::Auto:
2105 case Type::DeducedTemplateSpecialization:
2106 case Type::DependentTemplateSpecialization:
2107 case Type::PackExpansion:
2108 case Type::Pipe:
2109 // No template argument deduction for these types
2110 return Sema::TDK_Success;
2111 }
2112
2113 llvm_unreachable("Invalid Type Class!")::llvm::llvm_unreachable_internal("Invalid Type Class!", "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 2113)
;
2114}
2115
2116static Sema::TemplateDeductionResult
2117DeduceTemplateArguments(Sema &S,
2118 TemplateParameterList *TemplateParams,
2119 const TemplateArgument &Param,
2120 TemplateArgument Arg,
2121 TemplateDeductionInfo &Info,
2122 SmallVectorImpl<DeducedTemplateArgument> &Deduced) {
2123 // If the template argument is a pack expansion, perform template argument
2124 // deduction against the pattern of that expansion. This only occurs during
2125 // partial ordering.
2126 if (Arg.isPackExpansion())
2127 Arg = Arg.getPackExpansionPattern();
2128
2129 switch (Param.getKind()) {
2130 case TemplateArgument::Null:
2131 llvm_unreachable("Null template argument in parameter list")::llvm::llvm_unreachable_internal("Null template argument in parameter list"
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 2131)
;
2132
2133 case TemplateArgument::Type:
2134 if (Arg.getKind() == TemplateArgument::Type)
2135 return DeduceTemplateArgumentsByTypeMatch(S, TemplateParams,
2136 Param.getAsType(),
2137 Arg.getAsType(),
2138 Info, Deduced, 0);
2139 Info.FirstArg = Param;
2140 Info.SecondArg = Arg;
2141 return Sema::TDK_NonDeducedMismatch;
2142
2143 case TemplateArgument::Template:
2144 if (Arg.getKind() == TemplateArgument::Template)
2145 return DeduceTemplateArguments(S, TemplateParams,
2146 Param.getAsTemplate(),
2147 Arg.getAsTemplate(), Info, Deduced);
2148 Info.FirstArg = Param;
2149 Info.SecondArg = Arg;
2150 return Sema::TDK_NonDeducedMismatch;
2151
2152 case TemplateArgument::TemplateExpansion:
2153 llvm_unreachable("caller should handle pack expansions")::llvm::llvm_unreachable_internal("caller should handle pack expansions"
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 2153)
;
2154
2155 case TemplateArgument::Declaration:
2156 if (Arg.getKind() == TemplateArgument::Declaration &&
2157 isSameDeclaration(Param.getAsDecl(), Arg.getAsDecl()))
2158 return Sema::TDK_Success;
2159
2160 Info.FirstArg = Param;
2161 Info.SecondArg = Arg;
2162 return Sema::TDK_NonDeducedMismatch;
2163
2164 case TemplateArgument::NullPtr:
2165 if (Arg.getKind() == TemplateArgument::NullPtr &&
2166 S.Context.hasSameType(Param.getNullPtrType(), Arg.getNullPtrType()))
2167 return Sema::TDK_Success;
2168
2169 Info.FirstArg = Param;
2170 Info.SecondArg = Arg;
2171 return Sema::TDK_NonDeducedMismatch;
2172
2173 case TemplateArgument::Integral:
2174 if (Arg.getKind() == TemplateArgument::Integral) {
2175 if (hasSameExtendedValue(Param.getAsIntegral(), Arg.getAsIntegral()))
2176 return Sema::TDK_Success;
2177
2178 Info.FirstArg = Param;
2179 Info.SecondArg = Arg;
2180 return Sema::TDK_NonDeducedMismatch;
2181 }
2182
2183 if (Arg.getKind() == TemplateArgument::Expression) {
2184 Info.FirstArg = Param;
2185 Info.SecondArg = Arg;
2186 return Sema::TDK_NonDeducedMismatch;
2187 }
2188
2189 Info.FirstArg = Param;
2190 Info.SecondArg = Arg;
2191 return Sema::TDK_NonDeducedMismatch;
2192
2193 case TemplateArgument::Expression:
2194 if (NonTypeTemplateParmDecl *NTTP
2195 = getDeducedParameterFromExpr(Info, Param.getAsExpr())) {
2196 if (Arg.getKind() == TemplateArgument::Integral)
2197 return DeduceNonTypeTemplateArgument(S, TemplateParams, NTTP,
2198 Arg.getAsIntegral(),
2199 Arg.getIntegralType(),
2200 /*ArrayBound=*/false,
2201 Info, Deduced);
2202 if (Arg.getKind() == TemplateArgument::NullPtr)
2203 return DeduceNullPtrTemplateArgument(S, TemplateParams, NTTP,
2204 Arg.getNullPtrType(),
2205 Info, Deduced);
2206 if (Arg.getKind() == TemplateArgument::Expression)
2207 return DeduceNonTypeTemplateArgument(S, TemplateParams, NTTP,
2208 Arg.getAsExpr(), Info, Deduced);
2209 if (Arg.getKind() == TemplateArgument::Declaration)
2210 return DeduceNonTypeTemplateArgument(S, TemplateParams, NTTP,
2211 Arg.getAsDecl(),
2212 Arg.getParamTypeForDecl(),
2213 Info, Deduced);
2214
2215 Info.FirstArg = Param;
2216 Info.SecondArg = Arg;
2217 return Sema::TDK_NonDeducedMismatch;
2218 }
2219
2220 // Can't deduce anything, but that's okay.
2221 return Sema::TDK_Success;
2222
2223 case TemplateArgument::Pack:
2224 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-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 2224)
;
2225 }
2226
2227 llvm_unreachable("Invalid TemplateArgument Kind!")::llvm::llvm_unreachable_internal("Invalid TemplateArgument Kind!"
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 2227)
;
2228}
2229
2230/// Determine whether there is a template argument to be used for
2231/// deduction.
2232///
2233/// This routine "expands" argument packs in-place, overriding its input
2234/// parameters so that \c Args[ArgIdx] will be the available template argument.
2235///
2236/// \returns true if there is another template argument (which will be at
2237/// \c Args[ArgIdx]), false otherwise.
2238static bool hasTemplateArgumentForDeduction(ArrayRef<TemplateArgument> &Args,
2239 unsigned &ArgIdx) {
2240 if (ArgIdx == Args.size())
2241 return false;
2242
2243 const TemplateArgument &Arg = Args[ArgIdx];
2244 if (Arg.getKind() != TemplateArgument::Pack)
2245 return true;
2246
2247 assert(ArgIdx == Args.size() - 1 && "Pack not at the end of argument list?")((ArgIdx == Args.size() - 1 && "Pack not at the end of argument list?"
) ? static_cast<void> (0) : __assert_fail ("ArgIdx == Args.size() - 1 && \"Pack not at the end of argument list?\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 2247, __PRETTY_FUNCTION__))
;
2248 Args = Arg.pack_elements();
2249 ArgIdx = 0;
2250 return ArgIdx < Args.size();
2251}
2252
2253/// Determine whether the given set of template arguments has a pack
2254/// expansion that is not the last template argument.
2255static bool hasPackExpansionBeforeEnd(ArrayRef<TemplateArgument> Args) {
2256 bool FoundPackExpansion = false;
2257 for (const auto &A : Args) {
2258 if (FoundPackExpansion)
2259 return true;
2260
2261 if (A.getKind() == TemplateArgument::Pack)
2262 return hasPackExpansionBeforeEnd(A.pack_elements());
2263
2264 // FIXME: If this is a fixed-arity pack expansion from an outer level of
2265 // templates, it should not be treated as a pack expansion.
2266 if (A.isPackExpansion())
2267 FoundPackExpansion = true;
2268 }
2269
2270 return false;
2271}
2272
2273static Sema::TemplateDeductionResult
2274DeduceTemplateArguments(Sema &S, TemplateParameterList *TemplateParams,
2275 ArrayRef<TemplateArgument> Params,
2276 ArrayRef<TemplateArgument> Args,
2277 TemplateDeductionInfo &Info,
2278 SmallVectorImpl<DeducedTemplateArgument> &Deduced,
2279 bool NumberOfArgumentsMustMatch) {
2280 // C++0x [temp.deduct.type]p9:
2281 // If the template argument list of P contains a pack expansion that is not
2282 // the last template argument, the entire template argument list is a
2283 // non-deduced context.
2284 if (hasPackExpansionBeforeEnd(Params))
2285 return Sema::TDK_Success;
2286
2287 // C++0x [temp.deduct.type]p9:
2288 // If P has a form that contains <T> or <i>, then each argument Pi of the
2289 // respective template argument list P is compared with the corresponding
2290 // argument Ai of the corresponding template argument list of A.
2291 unsigned ArgIdx = 0, ParamIdx = 0;
2292 for (; hasTemplateArgumentForDeduction(Params, ParamIdx); ++ParamIdx) {
2293 if (!Params[ParamIdx].isPackExpansion()) {
2294 // The simple case: deduce template arguments by matching Pi and Ai.
2295
2296 // Check whether we have enough arguments.
2297 if (!hasTemplateArgumentForDeduction(Args, ArgIdx))
2298 return NumberOfArgumentsMustMatch
2299 ? Sema::TDK_MiscellaneousDeductionFailure
2300 : Sema::TDK_Success;
2301
2302 // C++1z [temp.deduct.type]p9:
2303 // During partial ordering, if Ai was originally a pack expansion [and]
2304 // Pi is not a pack expansion, template argument deduction fails.
2305 if (Args[ArgIdx].isPackExpansion())
2306 return Sema::TDK_MiscellaneousDeductionFailure;
2307
2308 // Perform deduction for this Pi/Ai pair.
2309 if (Sema::TemplateDeductionResult Result
2310 = DeduceTemplateArguments(S, TemplateParams,
2311 Params[ParamIdx], Args[ArgIdx],
2312 Info, Deduced))
2313 return Result;
2314
2315 // Move to the next argument.
2316 ++ArgIdx;
2317 continue;
2318 }
2319
2320 // The parameter is a pack expansion.
2321
2322 // C++0x [temp.deduct.type]p9:
2323 // If Pi is a pack expansion, then the pattern of Pi is compared with
2324 // each remaining argument in the template argument list of A. Each
2325 // comparison deduces template arguments for subsequent positions in the
2326 // template parameter packs expanded by Pi.
2327 TemplateArgument Pattern = Params[ParamIdx].getPackExpansionPattern();
2328
2329 // Prepare to deduce the packs within the pattern.
2330 PackDeductionScope PackScope(S, TemplateParams, Deduced, Info, Pattern);
2331
2332 // Keep track of the deduced template arguments for each parameter pack
2333 // expanded by this pack expansion (the outer index) and for each
2334 // template argument (the inner SmallVectors).
2335 for (; hasTemplateArgumentForDeduction(Args, ArgIdx) &&
2336 PackScope.hasNextElement();
2337 ++ArgIdx) {
2338 // Deduce template arguments from the pattern.
2339 if (Sema::TemplateDeductionResult Result
2340 = DeduceTemplateArguments(S, TemplateParams, Pattern, Args[ArgIdx],
2341 Info, Deduced))
2342 return Result;
2343
2344 PackScope.nextPackElement();
2345 }
2346
2347 // Build argument packs for each of the parameter packs expanded by this
2348 // pack expansion.
2349 if (auto Result = PackScope.finish())
2350 return Result;
2351 }
2352
2353 return Sema::TDK_Success;
2354}
2355
2356static Sema::TemplateDeductionResult
2357DeduceTemplateArguments(Sema &S,
2358 TemplateParameterList *TemplateParams,
2359 const TemplateArgumentList &ParamList,
2360 const TemplateArgumentList &ArgList,
2361 TemplateDeductionInfo &Info,
2362 SmallVectorImpl<DeducedTemplateArgument> &Deduced) {
2363 return DeduceTemplateArguments(S, TemplateParams, ParamList.asArray(),
2364 ArgList.asArray(), Info, Deduced,
2365 /*NumberOfArgumentsMustMatch*/false);
2366}
2367
2368/// Determine whether two template arguments are the same.
2369static bool isSameTemplateArg(ASTContext &Context,
2370 TemplateArgument X,
2371 const TemplateArgument &Y,
2372 bool PackExpansionMatchesPack = false) {
2373 // If we're checking deduced arguments (X) against original arguments (Y),
2374 // we will have flattened packs to non-expansions in X.
2375 if (PackExpansionMatchesPack && X.isPackExpansion() && !Y.isPackExpansion())
2376 X = X.getPackExpansionPattern();
2377
2378 if (X.getKind() != Y.getKind())
2379 return false;
2380
2381 switch (X.getKind()) {
2382 case TemplateArgument::Null:
2383 llvm_unreachable("Comparing NULL template argument")::llvm::llvm_unreachable_internal("Comparing NULL template argument"
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 2383)
;
2384
2385 case TemplateArgument::Type:
2386 return Context.getCanonicalType(X.getAsType()) ==
2387 Context.getCanonicalType(Y.getAsType());
2388
2389 case TemplateArgument::Declaration:
2390 return isSameDeclaration(X.getAsDecl(), Y.getAsDecl());
2391
2392 case TemplateArgument::NullPtr:
2393 return Context.hasSameType(X.getNullPtrType(), Y.getNullPtrType());
2394
2395 case TemplateArgument::Template:
2396 case TemplateArgument::TemplateExpansion:
2397 return Context.getCanonicalTemplateName(
2398 X.getAsTemplateOrTemplatePattern()).getAsVoidPointer() ==
2399 Context.getCanonicalTemplateName(
2400 Y.getAsTemplateOrTemplatePattern()).getAsVoidPointer();
2401
2402 case TemplateArgument::Integral:
2403 return hasSameExtendedValue(X.getAsIntegral(), Y.getAsIntegral());
2404
2405 case TemplateArgument::Expression: {
2406 llvm::FoldingSetNodeID XID, YID;
2407 X.getAsExpr()->Profile(XID, Context, true);
2408 Y.getAsExpr()->Profile(YID, Context, true);
2409 return XID == YID;
2410 }
2411
2412 case TemplateArgument::Pack:
2413 if (X.pack_size() != Y.pack_size())
2414 return false;
2415
2416 for (TemplateArgument::pack_iterator XP = X.pack_begin(),
2417 XPEnd = X.pack_end(),
2418 YP = Y.pack_begin();
2419 XP != XPEnd; ++XP, ++YP)
2420 if (!isSameTemplateArg(Context, *XP, *YP, PackExpansionMatchesPack))
2421 return false;
2422
2423 return true;
2424 }
2425
2426 llvm_unreachable("Invalid TemplateArgument Kind!")::llvm::llvm_unreachable_internal("Invalid TemplateArgument Kind!"
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 2426)
;
2427}
2428
2429/// Allocate a TemplateArgumentLoc where all locations have
2430/// been initialized to the given location.
2431///
2432/// \param Arg The template argument we are producing template argument
2433/// location information for.
2434///
2435/// \param NTTPType For a declaration template argument, the type of
2436/// the non-type template parameter that corresponds to this template
2437/// argument. Can be null if no type sugar is available to add to the
2438/// type from the template argument.
2439///
2440/// \param Loc The source location to use for the resulting template
2441/// argument.
2442TemplateArgumentLoc
2443Sema::getTrivialTemplateArgumentLoc(const TemplateArgument &Arg,
2444 QualType NTTPType, SourceLocation Loc) {
2445 switch (Arg.getKind()) {
2446 case TemplateArgument::Null:
2447 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-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 2447)
;
2448
2449 case TemplateArgument::Type:
2450 return TemplateArgumentLoc(
2451 Arg, Context.getTrivialTypeSourceInfo(Arg.getAsType(), Loc));
2452
2453 case TemplateArgument::Declaration: {
2454 if (NTTPType.isNull())
2455 NTTPType = Arg.getParamTypeForDecl();
2456 Expr *E = BuildExpressionFromDeclTemplateArgument(Arg, NTTPType, Loc)
2457 .getAs<Expr>();
2458 return TemplateArgumentLoc(TemplateArgument(E), E);
2459 }
2460
2461 case TemplateArgument::NullPtr: {
2462 if (NTTPType.isNull())
2463 NTTPType = Arg.getNullPtrType();
2464 Expr *E = BuildExpressionFromDeclTemplateArgument(Arg, NTTPType, Loc)
2465 .getAs<Expr>();
2466 return TemplateArgumentLoc(TemplateArgument(NTTPType, /*isNullPtr*/true),
2467 E);
2468 }
2469
2470 case TemplateArgument::Integral: {
2471 Expr *E =
2472 BuildExpressionFromIntegralTemplateArgument(Arg, Loc).getAs<Expr>();
2473 return TemplateArgumentLoc(TemplateArgument(E), E);
2474 }
2475
2476 case TemplateArgument::Template:
2477 case TemplateArgument::TemplateExpansion: {
2478 NestedNameSpecifierLocBuilder Builder;
2479 TemplateName Template = Arg.getAsTemplate();
2480 if (DependentTemplateName *DTN = Template.getAsDependentTemplateName())
2481 Builder.MakeTrivial(Context, DTN->getQualifier(), Loc);
2482 else if (QualifiedTemplateName *QTN =
2483 Template.getAsQualifiedTemplateName())
2484 Builder.MakeTrivial(Context, QTN->getQualifier(), Loc);
2485
2486 if (Arg.getKind() == TemplateArgument::Template)
2487 return TemplateArgumentLoc(Arg, Builder.getWithLocInContext(Context),
2488 Loc);
2489
2490 return TemplateArgumentLoc(Arg, Builder.getWithLocInContext(Context),
2491 Loc, Loc);
2492 }
2493
2494 case TemplateArgument::Expression:
2495 return TemplateArgumentLoc(Arg, Arg.getAsExpr());
2496
2497 case TemplateArgument::Pack:
2498 return TemplateArgumentLoc(Arg, TemplateArgumentLocInfo());
2499 }
2500
2501 llvm_unreachable("Invalid TemplateArgument Kind!")::llvm::llvm_unreachable_internal("Invalid TemplateArgument Kind!"
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 2501)
;
2502}
2503
2504/// Convert the given deduced template argument and add it to the set of
2505/// fully-converted template arguments.
2506static bool
2507ConvertDeducedTemplateArgument(Sema &S, NamedDecl *Param,
2508 DeducedTemplateArgument Arg,
2509 NamedDecl *Template,
2510 TemplateDeductionInfo &Info,
2511 bool IsDeduced,
2512 SmallVectorImpl<TemplateArgument> &Output) {
2513 auto ConvertArg = [&](DeducedTemplateArgument Arg,
2514 unsigned ArgumentPackIndex) {
2515 // Convert the deduced template argument into a template
2516 // argument that we can check, almost as if the user had written
2517 // the template argument explicitly.
2518 TemplateArgumentLoc ArgLoc =
2519 S.getTrivialTemplateArgumentLoc(Arg, QualType(), Info.getLocation());
2520
2521 // Check the template argument, converting it as necessary.
2522 return S.CheckTemplateArgument(
2523 Param, ArgLoc, Template, Template->getLocation(),
2524 Template->getSourceRange().getEnd(), ArgumentPackIndex, Output,
2525 IsDeduced
2526 ? (Arg.wasDeducedFromArrayBound() ? Sema::CTAK_DeducedFromArrayBound
2527 : Sema::CTAK_Deduced)
2528 : Sema::CTAK_Specified);
2529 };
2530
2531 if (Arg.getKind() == TemplateArgument::Pack) {
2532 // This is a template argument pack, so check each of its arguments against
2533 // the template parameter.
2534 SmallVector<TemplateArgument, 2> PackedArgsBuilder;
2535 for (const auto &P : Arg.pack_elements()) {
2536 // When converting the deduced template argument, append it to the
2537 // general output list. We need to do this so that the template argument
2538 // checking logic has all of the prior template arguments available.
2539 DeducedTemplateArgument InnerArg(P);
2540 InnerArg.setDeducedFromArrayBound(Arg.wasDeducedFromArrayBound());
2541 assert(InnerArg.getKind() != TemplateArgument::Pack &&((InnerArg.getKind() != TemplateArgument::Pack && "deduced nested pack"
) ? static_cast<void> (0) : __assert_fail ("InnerArg.getKind() != TemplateArgument::Pack && \"deduced nested pack\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 2542, __PRETTY_FUNCTION__))
2542 "deduced nested pack")((InnerArg.getKind() != TemplateArgument::Pack && "deduced nested pack"
) ? static_cast<void> (0) : __assert_fail ("InnerArg.getKind() != TemplateArgument::Pack && \"deduced nested pack\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 2542, __PRETTY_FUNCTION__))
;
2543 if (P.isNull()) {
2544 // We deduced arguments for some elements of this pack, but not for
2545 // all of them. This happens if we get a conditionally-non-deduced
2546 // context in a pack expansion (such as an overload set in one of the
2547 // arguments).
2548 S.Diag(Param->getLocation(),
2549 diag::err_template_arg_deduced_incomplete_pack)
2550 << Arg << Param;
2551 return true;
2552 }
2553 if (ConvertArg(InnerArg, PackedArgsBuilder.size()))
2554 return true;
2555
2556 // Move the converted template argument into our argument pack.
2557 PackedArgsBuilder.push_back(Output.pop_back_val());
2558 }
2559
2560 // If the pack is empty, we still need to substitute into the parameter
2561 // itself, in case that substitution fails.
2562 if (PackedArgsBuilder.empty()) {
2563 LocalInstantiationScope Scope(S);
2564 TemplateArgumentList TemplateArgs(TemplateArgumentList::OnStack, Output);
2565 MultiLevelTemplateArgumentList Args(TemplateArgs);
2566
2567 if (auto *NTTP = dyn_cast<NonTypeTemplateParmDecl>(Param)) {
2568 Sema::InstantiatingTemplate Inst(S, Template->getLocation(), Template,
2569 NTTP, Output,
2570 Template->getSourceRange());
2571 if (Inst.isInvalid() ||
2572 S.SubstType(NTTP->getType(), Args, NTTP->getLocation(),
2573 NTTP->getDeclName()).isNull())
2574 return true;
2575 } else if (auto *TTP = dyn_cast<TemplateTemplateParmDecl>(Param)) {
2576 Sema::InstantiatingTemplate Inst(S, Template->getLocation(), Template,
2577 TTP, Output,
2578 Template->getSourceRange());
2579 if (Inst.isInvalid() || !S.SubstDecl(TTP, S.CurContext, Args))
2580 return true;
2581 }
2582 // For type parameters, no substitution is ever required.
2583 }
2584
2585 // Create the resulting argument pack.
2586 Output.push_back(
2587 TemplateArgument::CreatePackCopy(S.Context, PackedArgsBuilder));
2588 return false;
2589 }
2590
2591 return ConvertArg(Arg, 0);
2592}
2593
2594// FIXME: This should not be a template, but
2595// ClassTemplatePartialSpecializationDecl sadly does not derive from
2596// TemplateDecl.
2597template<typename TemplateDeclT>
2598static Sema::TemplateDeductionResult ConvertDeducedTemplateArguments(
2599 Sema &S, TemplateDeclT *Template, bool IsDeduced,
2600 SmallVectorImpl<DeducedTemplateArgument> &Deduced,
2601 TemplateDeductionInfo &Info, SmallVectorImpl<TemplateArgument> &Builder,
2602 LocalInstantiationScope *CurrentInstantiationScope = nullptr,
2603 unsigned NumAlreadyConverted = 0, bool PartialOverloading = false) {
2604 TemplateParameterList *TemplateParams = Template->getTemplateParameters();
2605
2606 for (unsigned I = 0, N = TemplateParams->size(); I != N; ++I) {
2607 NamedDecl *Param = TemplateParams->getParam(I);
2608
2609 // C++0x [temp.arg.explicit]p3:
2610 // A trailing template parameter pack (14.5.3) not otherwise deduced will
2611 // be deduced to an empty sequence of template arguments.
2612 // FIXME: Where did the word "trailing" come from?
2613 if (Deduced[I].isNull() && Param->isTemplateParameterPack()) {
2614 if (auto Result = PackDeductionScope(S, TemplateParams, Deduced, Info, I)
2615 .finish(/*TreatNoDeductionsAsNonDeduced*/false))
2616 return Result;
2617 }
2618
2619 if (!Deduced[I].isNull()) {
2620 if (I < NumAlreadyConverted) {
2621 // We may have had explicitly-specified template arguments for a
2622 // template parameter pack (that may or may not have been extended
2623 // via additional deduced arguments).
2624 if (Param->isParameterPack() && CurrentInstantiationScope &&
2625 CurrentInstantiationScope->getPartiallySubstitutedPack() == Param) {
2626 // Forget the partially-substituted pack; its substitution is now
2627 // complete.
2628 CurrentInstantiationScope->ResetPartiallySubstitutedPack();
2629 // We still need to check the argument in case it was extended by
2630 // deduction.
2631 } else {
2632 // We have already fully type-checked and converted this
2633 // argument, because it was explicitly-specified. Just record the
2634 // presence of this argument.
2635 Builder.push_back(Deduced[I]);
2636 continue;
2637 }
2638 }
2639
2640 // We may have deduced this argument, so it still needs to be
2641 // checked and converted.
2642 if (ConvertDeducedTemplateArgument(S, Param, Deduced[I], Template, Info,
2643 IsDeduced, Builder)) {
2644 Info.Param = makeTemplateParameter(Param);
2645 // FIXME: These template arguments are temporary. Free them!
2646 Info.reset(TemplateArgumentList::CreateCopy(S.Context, Builder));
2647 return Sema::TDK_SubstitutionFailure;
2648 }
2649
2650 continue;
2651 }
2652
2653 // Substitute into the default template argument, if available.
2654 bool HasDefaultArg = false;
2655 TemplateDecl *TD = dyn_cast<TemplateDecl>(Template);
2656 if (!TD) {
2657 assert(isa<ClassTemplatePartialSpecializationDecl>(Template) ||((isa<ClassTemplatePartialSpecializationDecl>(Template)
|| isa<VarTemplatePartialSpecializationDecl>(Template)
) ? static_cast<void> (0) : __assert_fail ("isa<ClassTemplatePartialSpecializationDecl>(Template) || isa<VarTemplatePartialSpecializationDecl>(Template)"
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 2658, __PRETTY_FUNCTION__))
2658 isa<VarTemplatePartialSpecializationDecl>(Template))((isa<ClassTemplatePartialSpecializationDecl>(Template)
|| isa<VarTemplatePartialSpecializationDecl>(Template)
) ? static_cast<void> (0) : __assert_fail ("isa<ClassTemplatePartialSpecializationDecl>(Template) || isa<VarTemplatePartialSpecializationDecl>(Template)"
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 2658, __PRETTY_FUNCTION__))
;
2659 return Sema::TDK_Incomplete;
2660 }
2661
2662 TemplateArgumentLoc DefArg = S.SubstDefaultTemplateArgumentIfAvailable(
2663 TD, TD->getLocation(), TD->getSourceRange().getEnd(), Param, Builder,
2664 HasDefaultArg);
2665
2666 // If there was no default argument, deduction is incomplete.
2667 if (DefArg.getArgument().isNull()) {
2668 Info.Param = makeTemplateParameter(
2669 const_cast<NamedDecl *>(TemplateParams->getParam(I)));
2670 Info.reset(TemplateArgumentList::CreateCopy(S.Context, Builder));
2671 if (PartialOverloading) break;
2672
2673 return HasDefaultArg ? Sema::TDK_SubstitutionFailure
2674 : Sema::TDK_Incomplete;
2675 }
2676
2677 // Check whether we can actually use the default argument.
2678 if (S.CheckTemplateArgument(Param, DefArg, TD, TD->getLocation(),
2679 TD->getSourceRange().getEnd(), 0, Builder,
2680 Sema::CTAK_Specified)) {
2681 Info.Param = makeTemplateParameter(
2682 const_cast<NamedDecl *>(TemplateParams->getParam(I)));
2683 // FIXME: These template arguments are temporary. Free them!
2684 Info.reset(TemplateArgumentList::CreateCopy(S.Context, Builder));
2685 return Sema::TDK_SubstitutionFailure;
2686 }
2687
2688 // If we get here, we successfully used the default template argument.
2689 }
2690
2691 return Sema::TDK_Success;
2692}
2693
2694static DeclContext *getAsDeclContextOrEnclosing(Decl *D) {
2695 if (auto *DC = dyn_cast<DeclContext>(D))
2696 return DC;
2697 return D->getDeclContext();
2698}
2699
2700template<typename T> struct IsPartialSpecialization {
2701 static constexpr bool value = false;
2702};
2703template<>
2704struct IsPartialSpecialization<ClassTemplatePartialSpecializationDecl> {
2705 static constexpr bool value = true;
2706};
2707template<>
2708struct IsPartialSpecialization<VarTemplatePartialSpecializationDecl> {
2709 static constexpr bool value = true;
2710};
2711
2712/// Complete template argument deduction for a partial specialization.
2713template <typename T>
2714static typename std::enable_if<IsPartialSpecialization<T>::value,
2715 Sema::TemplateDeductionResult>::type
2716FinishTemplateArgumentDeduction(
2717 Sema &S, T *Partial, bool IsPartialOrdering,
2718 const TemplateArgumentList &TemplateArgs,
2719 SmallVectorImpl<DeducedTemplateArgument> &Deduced,
2720 TemplateDeductionInfo &Info) {
2721 // Unevaluated SFINAE context.
2722 EnterExpressionEvaluationContext Unevaluated(
2723 S, Sema::ExpressionEvaluationContext::Unevaluated);
2724 Sema::SFINAETrap Trap(S);
2725
2726 Sema::ContextRAII SavedContext(S, getAsDeclContextOrEnclosing(Partial));
2727
2728 // C++ [temp.deduct.type]p2:
2729 // [...] or if any template argument remains neither deduced nor
2730 // explicitly specified, template argument deduction fails.
2731 SmallVector<TemplateArgument, 4> Builder;
2732 if (auto Result = ConvertDeducedTemplateArguments(
2733 S, Partial, IsPartialOrdering, Deduced, Info, Builder))
2734 return Result;
2735
2736 // Form the template argument list from the deduced template arguments.
2737 TemplateArgumentList *DeducedArgumentList
2738 = TemplateArgumentList::CreateCopy(S.Context, Builder);
2739
2740 Info.reset(DeducedArgumentList);
2741
2742 // Substitute the deduced template arguments into the template
2743 // arguments of the class template partial specialization, and
2744 // verify that the instantiated template arguments are both valid
2745 // and are equivalent to the template arguments originally provided
2746 // to the class template.
2747 LocalInstantiationScope InstScope(S);
2748 auto *Template = Partial->getSpecializedTemplate();
2749 const ASTTemplateArgumentListInfo *PartialTemplArgInfo =
2750 Partial->getTemplateArgsAsWritten();
2751 const TemplateArgumentLoc *PartialTemplateArgs =
2752 PartialTemplArgInfo->getTemplateArgs();
2753
2754 TemplateArgumentListInfo InstArgs(PartialTemplArgInfo->LAngleLoc,
2755 PartialTemplArgInfo->RAngleLoc);
2756
2757 if (S.Subst(PartialTemplateArgs, PartialTemplArgInfo->NumTemplateArgs,
2758 InstArgs, MultiLevelTemplateArgumentList(*DeducedArgumentList))) {
2759 unsigned ArgIdx = InstArgs.size(), ParamIdx = ArgIdx;
2760 if (ParamIdx >= Partial->getTemplateParameters()->size())
2761 ParamIdx = Partial->getTemplateParameters()->size() - 1;
2762
2763 Decl *Param = const_cast<NamedDecl *>(
2764 Partial->getTemplateParameters()->getParam(ParamIdx));
2765 Info.Param = makeTemplateParameter(Param);
2766 Info.FirstArg = PartialTemplateArgs[ArgIdx].getArgument();
2767 return Sema::TDK_SubstitutionFailure;
2768 }
2769
2770 SmallVector<TemplateArgument, 4> ConvertedInstArgs;
2771 if (S.CheckTemplateArgumentList(Template, Partial->getLocation(), InstArgs,
2772 false, ConvertedInstArgs))
2773 return Sema::TDK_SubstitutionFailure;
2774
2775 TemplateParameterList *TemplateParams = Template->getTemplateParameters();
2776 for (unsigned I = 0, E = TemplateParams->size(); I != E; ++I) {
2777 TemplateArgument InstArg = ConvertedInstArgs.data()[I];
2778 if (!isSameTemplateArg(S.Context, TemplateArgs[I], InstArg)) {
2779 Info.Param = makeTemplateParameter(TemplateParams->getParam(I));
2780 Info.FirstArg = TemplateArgs[I];
2781 Info.SecondArg = InstArg;
2782 return Sema::TDK_NonDeducedMismatch;
2783 }
2784 }
2785
2786 if (Trap.hasErrorOccurred())
2787 return Sema::TDK_SubstitutionFailure;
2788
2789 return Sema::TDK_Success;
2790}
2791
2792/// Complete template argument deduction for a class or variable template,
2793/// when partial ordering against a partial specialization.
2794// FIXME: Factor out duplication with partial specialization version above.
2795static Sema::TemplateDeductionResult FinishTemplateArgumentDeduction(
2796 Sema &S, TemplateDecl *Template, bool PartialOrdering,
2797 const TemplateArgumentList &TemplateArgs,
2798 SmallVectorImpl<DeducedTemplateArgument> &Deduced,
2799 TemplateDeductionInfo &Info) {
2800 // Unevaluated SFINAE context.
2801 EnterExpressionEvaluationContext Unevaluated(
2802 S, Sema::ExpressionEvaluationContext::Unevaluated);
2803 Sema::SFINAETrap Trap(S);
2804
2805 Sema::ContextRAII SavedContext(S, getAsDeclContextOrEnclosing(Template));
2806
2807 // C++ [temp.deduct.type]p2:
2808 // [...] or if any template argument remains neither deduced nor
2809 // explicitly specified, template argument deduction fails.
2810 SmallVector<TemplateArgument, 4> Builder;
2811 if (auto Result = ConvertDeducedTemplateArguments(
2812 S, Template, /*IsDeduced*/PartialOrdering, Deduced, Info, Builder))
2813 return Result;
2814
2815 // Check that we produced the correct argument list.
2816 TemplateParameterList *TemplateParams = Template->getTemplateParameters();
2817 for (unsigned I = 0, E = TemplateParams->size(); I != E; ++I) {
2818 TemplateArgument InstArg = Builder[I];
2819 if (!isSameTemplateArg(S.Context, TemplateArgs[I], InstArg,
2820 /*PackExpansionMatchesPack*/true)) {
2821 Info.Param = makeTemplateParameter(TemplateParams->getParam(I));
2822 Info.FirstArg = TemplateArgs[I];
2823 Info.SecondArg = InstArg;
2824 return Sema::TDK_NonDeducedMismatch;
2825 }
2826 }
2827
2828 if (Trap.hasErrorOccurred())
2829 return Sema::TDK_SubstitutionFailure;
2830
2831 return Sema::TDK_Success;
2832}
2833
2834
2835/// Perform template argument deduction to determine whether
2836/// the given template arguments match the given class template
2837/// partial specialization per C++ [temp.class.spec.match].
2838Sema::TemplateDeductionResult
2839Sema::DeduceTemplateArguments(ClassTemplatePartialSpecializationDecl *Partial,
2840 const TemplateArgumentList &TemplateArgs,
2841 TemplateDeductionInfo &Info) {
2842 if (Partial->isInvalidDecl())
2843 return TDK_Invalid;
2844
2845 // C++ [temp.class.spec.match]p2:
2846 // A partial specialization matches a given actual template
2847 // argument list if the template arguments of the partial
2848 // specialization can be deduced from the actual template argument
2849 // list (14.8.2).
2850
2851 // Unevaluated SFINAE context.
2852 EnterExpressionEvaluationContext Unevaluated(
2853 *this, Sema::ExpressionEvaluationContext::Unevaluated);
2854 SFINAETrap Trap(*this);
2855
2856 SmallVector<DeducedTemplateArgument, 4> Deduced;
2857 Deduced.resize(Partial->getTemplateParameters()->size());
2858 if (TemplateDeductionResult Result
2859 = ::DeduceTemplateArguments(*this,
2860 Partial->getTemplateParameters(),
2861 Partial->getTemplateArgs(),
2862 TemplateArgs, Info, Deduced))
2863 return Result;
2864
2865 SmallVector<TemplateArgument, 4> DeducedArgs(Deduced.begin(), Deduced.end());
2866 InstantiatingTemplate Inst(*this, Info.getLocation(), Partial, DeducedArgs,
2867 Info);
2868 if (Inst.isInvalid())
2869 return TDK_InstantiationDepth;
2870
2871 if (Trap.hasErrorOccurred())
2872 return Sema::TDK_SubstitutionFailure;
2873
2874 return ::FinishTemplateArgumentDeduction(
2875 *this, Partial, /*IsPartialOrdering=*/false, TemplateArgs, Deduced, Info);
2876}
2877
2878/// Perform template argument deduction to determine whether
2879/// the given template arguments match the given variable template
2880/// partial specialization per C++ [temp.class.spec.match].
2881Sema::TemplateDeductionResult
2882Sema::DeduceTemplateArguments(VarTemplatePartialSpecializationDecl *Partial,
2883 const TemplateArgumentList &TemplateArgs,
2884 TemplateDeductionInfo &Info) {
2885 if (Partial->isInvalidDecl())
2886 return TDK_Invalid;
2887
2888 // C++ [temp.class.spec.match]p2:
2889 // A partial specialization matches a given actual template
2890 // argument list if the template arguments of the partial
2891 // specialization can be deduced from the actual template argument
2892 // list (14.8.2).
2893
2894 // Unevaluated SFINAE context.
2895 EnterExpressionEvaluationContext Unevaluated(
2896 *this, Sema::ExpressionEvaluationContext::Unevaluated);
2897 SFINAETrap Trap(*this);
2898
2899 SmallVector<DeducedTemplateArgument, 4> Deduced;
2900 Deduced.resize(Partial->getTemplateParameters()->size());
2901 if (TemplateDeductionResult Result = ::DeduceTemplateArguments(
2902 *this, Partial->getTemplateParameters(), Partial->getTemplateArgs(),
2903 TemplateArgs, Info, Deduced))
2904 return Result;
2905
2906 SmallVector<TemplateArgument, 4> DeducedArgs(Deduced.begin(), Deduced.end());
2907 InstantiatingTemplate Inst(*this, Info.getLocation(), Partial, DeducedArgs,
2908 Info);
2909 if (Inst.isInvalid())
2910 return TDK_InstantiationDepth;
2911
2912 if (Trap.hasErrorOccurred())
2913 return Sema::TDK_SubstitutionFailure;
2914
2915 return ::FinishTemplateArgumentDeduction(
2916 *this, Partial, /*IsPartialOrdering=*/false, TemplateArgs, Deduced, Info);
2917}
2918
2919/// Determine whether the given type T is a simple-template-id type.
2920static bool isSimpleTemplateIdType(QualType T) {
2921 if (const TemplateSpecializationType *Spec
36.1
'Spec' is non-null
36.1
'Spec' is non-null
36.1
'Spec' is non-null
37
Taking true branch
2922 = T->getAs<TemplateSpecializationType>())
36
Assuming the object is a 'TemplateSpecializationType'
2923 return Spec->getTemplateName().getAsTemplateDecl() != nullptr;
38
Assuming the condition is false
39
Returning zero, which participates in a condition later
2924 2925 // C++17 [temp.local]p2: 2926 // the injected-class-name [...] is equivalent to the template-name followed 2927 // by the template-arguments of the class template specialization or partial 2928 // specialization enclosed in <> 2929 // ... which means it's equivalent to a simple-template-id. 2930 // 2931 // This only arises during class template argument deduction for a copy 2932 // deduction candidate, where it permits slicing. 2933 if (T->getAs<InjectedClassNameType>()) 2934 return true; 2935 2936 return false; 2937} 2938 2939/// Substitute the explicitly-provided template arguments into the 2940/// given function template according to C++ [temp.arg.explicit]. 2941/// 2942/// \param FunctionTemplate the function template into which the explicit 2943/// template arguments will be substituted. 2944/// 2945/// \param ExplicitTemplateArgs the explicitly-specified template 2946/// arguments. 2947/// 2948/// \param Deduced the deduced template arguments, which will be populated 2949/// with the converted and checked explicit template arguments. 2950/// 2951/// \param ParamTypes will be populated with the instantiated function 2952/// parameters. 2953/// 2954/// \param FunctionType if non-NULL, the result type of the function template 2955/// will also be instantiated and the pointed-to value will be updated with 2956/// the instantiated function type. 2957/// 2958/// \param Info if substitution fails for any reason, this object will be 2959/// populated with more information about the failure. 2960/// 2961/// \returns TDK_Success if substitution was successful, or some failure 2962/// condition. 2963Sema::TemplateDeductionResult 2964Sema::SubstituteExplicitTemplateArguments( 2965 FunctionTemplateDecl *FunctionTemplate, 2966 TemplateArgumentListInfo &ExplicitTemplateArgs, 2967 SmallVectorImpl<DeducedTemplateArgument> &Deduced, 2968 SmallVectorImpl<QualType> &ParamTypes, 2969 QualType *FunctionType, 2970 TemplateDeductionInfo &Info) { 2971 FunctionDecl *Function = FunctionTemplate->getTemplatedDecl(); 2972 TemplateParameterList *TemplateParams 2973 = FunctionTemplate->getTemplateParameters(); 2974 2975 if (ExplicitTemplateArgs.size() == 0) { 2976 // No arguments to substitute; just copy over the parameter types and 2977 // fill in the function type. 2978 for (auto P : Function->parameters()) 2979 ParamTypes.push_back(P->getType()); 2980 2981 if (FunctionType) 2982 *FunctionType = Function->getType(); 2983 return TDK_Success; 2984 } 2985 2986 // Unevaluated SFINAE context. 2987 EnterExpressionEvaluationContext Unevaluated( 2988 *this, Sema::ExpressionEvaluationContext::Unevaluated); 2989 SFINAETrap Trap(*this); 2990 2991 // C++ [temp.arg.explicit]p3: 2992 // Template arguments that are present shall be specified in the 2993 // declaration order of their corresponding template-parameters. The 2994 // template argument list shall not specify more template-arguments than 2995 // there are corresponding template-parameters. 2996 SmallVector<TemplateArgument, 4> Builder; 2997 2998 // Enter a new template instantiation context where we check the 2999 // explicitly-specified template arguments against this function template, 3000 // and then substitute them into the function parameter types. 3001 SmallVector<TemplateArgument, 4> DeducedArgs; 3002 InstantiatingTemplate Inst( 3003 *this, Info.getLocation(), FunctionTemplate, DeducedArgs, 3004 CodeSynthesisContext::ExplicitTemplateArgumentSubstitution, Info); 3005 if (Inst.isInvalid()) 3006 return TDK_InstantiationDepth; 3007 3008 if (CheckTemplateArgumentList(FunctionTemplate, SourceLocation(), 3009 ExplicitTemplateArgs, true, Builder, false) || 3010 Trap.hasErrorOccurred()) { 3011 unsigned Index = Builder.size(); 3012 if (Index >= TemplateParams->size()) 3013 return TDK_SubstitutionFailure; 3014 Info.Param = makeTemplateParameter(TemplateParams->getParam(Index)); 3015 return TDK_InvalidExplicitArguments; 3016 } 3017 3018 // Form the template argument list from the explicitly-specified 3019 // template arguments. 3020 TemplateArgumentList *ExplicitArgumentList 3021 = TemplateArgumentList::CreateCopy(Context, Builder); 3022 Info.setExplicitArgs(ExplicitArgumentList); 3023 3024 // Template argument deduction and the final substitution should be 3025 // done in the context of the templated declaration. Explicit 3026 // argument substitution, on the other hand, needs to happen in the 3027 // calling context. 3028 ContextRAII SavedContext(*this, FunctionTemplate->getTemplatedDecl()); 3029 3030 // If we deduced template arguments for a template parameter pack, 3031 // note that the template argument pack is partially substituted and record 3032 // the explicit template arguments. They'll be used as part of deduction 3033 // for this template parameter pack. 3034 unsigned PartiallySubstitutedPackIndex = -1u; 3035 if (!Builder.empty()) { 3036 const TemplateArgument &Arg = Builder.back(); 3037 if (Arg.getKind() == TemplateArgument::Pack) { 3038 auto *Param = TemplateParams->getParam(Builder.size() - 1); 3039 // If this is a fully-saturated fixed-size pack, it should be 3040 // fully-substituted, not partially-substituted. 3041 Optional<unsigned> Expansions = getExpandedPackSize(Param); 3042 if (!Expansions || Arg.pack_size() < *Expansions) { 3043 PartiallySubstitutedPackIndex = Builder.size() - 1; 3044 CurrentInstantiationScope->SetPartiallySubstitutedPack( 3045 Param, Arg.pack_begin(), Arg.pack_size()); 3046 } 3047 } 3048 } 3049 3050 const FunctionProtoType *Proto 3051 = Function->getType()->getAs<FunctionProtoType>(); 3052 assert(Proto && "Function template does not have a prototype?")((Proto && "Function template does not have a prototype?"
) ? static_cast<void> (0) : __assert_fail ("Proto && \"Function template does not have a prototype?\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 3052, __PRETTY_FUNCTION__))
; 3053 3054 // Isolate our substituted parameters from our caller. 3055 LocalInstantiationScope InstScope(*this, /*MergeWithOuterScope*/true); 3056 3057 ExtParameterInfoBuilder ExtParamInfos; 3058 3059 // Instantiate the types of each of the function parameters given the 3060 // explicitly-specified template arguments. If the function has a trailing 3061 // return type, substitute it after the arguments to ensure we substitute 3062 // in lexical order. 3063 if (Proto->hasTrailingReturn()) { 3064 if (SubstParmTypes(Function->getLocation(), Function->parameters(), 3065 Proto->getExtParameterInfosOrNull(), 3066 MultiLevelTemplateArgumentList(*ExplicitArgumentList), 3067 ParamTypes, /*params*/ nullptr, ExtParamInfos)) 3068 return TDK_SubstitutionFailure; 3069 } 3070 3071 // Instantiate the return type. 3072 QualType ResultType; 3073 { 3074 // C++11 [expr.prim.general]p3: 3075 // If a declaration declares a member function or member function 3076 // template of a class X, the expression this is a prvalue of type 3077 // "pointer to cv-qualifier-seq X" between the optional cv-qualifer-seq 3078 // and the end of the function-definition, member-declarator, or 3079 // declarator. 3080 Qualifiers ThisTypeQuals; 3081 CXXRecordDecl *ThisContext = nullptr; 3082 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Function)) { 3083 ThisContext = Method->getParent(); 3084 ThisTypeQuals = Method->getMethodQualifiers(); 3085 } 3086 3087 CXXThisScopeRAII ThisScope(*this, ThisContext, ThisTypeQuals, 3088 getLangOpts().CPlusPlus11); 3089 3090 ResultType = 3091 SubstType(Proto->getReturnType(), 3092 MultiLevelTemplateArgumentList(*ExplicitArgumentList), 3093 Function->getTypeSpecStartLoc(), Function->getDeclName()); 3094 if (ResultType.isNull() || Trap.hasErrorOccurred()) 3095 return TDK_SubstitutionFailure; 3096 // CUDA: Kernel function must have 'void' return type. 3097 if (getLangOpts().CUDA) 3098 if (Function->hasAttr<CUDAGlobalAttr>() && !ResultType->isVoidType()) { 3099 Diag(Function->getLocation(), diag::err_kern_type_not_void_return) 3100 << Function->getType() << Function->getSourceRange(); 3101 return TDK_SubstitutionFailure; 3102 } 3103 } 3104 3105 // Instantiate the types of each of the function parameters given the 3106 // explicitly-specified template arguments if we didn't do so earlier. 3107 if (!Proto->hasTrailingReturn() && 3108 SubstParmTypes(Function->getLocation(), Function->parameters(), 3109 Proto->getExtParameterInfosOrNull(), 3110 MultiLevelTemplateArgumentList(*ExplicitArgumentList), 3111 ParamTypes, /*params*/ nullptr, ExtParamInfos)) 3112 return TDK_SubstitutionFailure; 3113 3114 if (FunctionType) { 3115 auto EPI = Proto->getExtProtoInfo(); 3116 EPI.ExtParameterInfos = ExtParamInfos.getPointerOrNull(ParamTypes.size()); 3117 3118 // In C++1z onwards, exception specifications are part of the function type, 3119 // so substitution into the type must also substitute into the exception 3120 // specification. 3121 SmallVector<QualType, 4> ExceptionStorage; 3122 if (getLangOpts().CPlusPlus17 && 3123 SubstExceptionSpec( 3124 Function->getLocation(), EPI.ExceptionSpec, ExceptionStorage, 3125 MultiLevelTemplateArgumentList(*ExplicitArgumentList))) 3126 return TDK_SubstitutionFailure; 3127 3128 *FunctionType = BuildFunctionType(ResultType, ParamTypes, 3129 Function->getLocation(), 3130 Function->getDeclName(), 3131 EPI); 3132 if (FunctionType->isNull() || Trap.hasErrorOccurred()) 3133 return TDK_SubstitutionFailure; 3134 } 3135 3136 // C++ [temp.arg.explicit]p2: 3137 // Trailing template arguments that can be deduced (14.8.2) may be 3138 // omitted from the list of explicit template-arguments. If all of the 3139 // template arguments can be deduced, they may all be omitted; in this 3140 // case, the empty template argument list <> itself may also be omitted. 3141 // 3142 // Take all of the explicitly-specified arguments and put them into 3143 // the set of deduced template arguments. The partially-substituted 3144 // parameter pack, however, will be set to NULL since the deduction 3145 // mechanism handles the partially-substituted argument pack directly. 3146 Deduced.reserve(TemplateParams->size()); 3147 for (unsigned I = 0, N = ExplicitArgumentList->size(); I != N; ++I) { 3148 const TemplateArgument &Arg = ExplicitArgumentList->get(I); 3149 if (I == PartiallySubstitutedPackIndex) 3150 Deduced.push_back(DeducedTemplateArgument()); 3151 else 3152 Deduced.push_back(Arg); 3153 } 3154 3155 return TDK_Success; 3156} 3157 3158/// Check whether the deduced argument type for a call to a function 3159/// template matches the actual argument type per C++ [temp.deduct.call]p4. 3160static Sema::TemplateDeductionResult 3161CheckOriginalCallArgDeduction(Sema &S, TemplateDeductionInfo &Info, 3162 Sema::OriginalCallArg OriginalArg, 3163 QualType DeducedA) { 3164 ASTContext &Context = S.Context; 3165 3166 auto Failed = [&]() -> Sema::TemplateDeductionResult { 3167 Info.FirstArg = TemplateArgument(DeducedA); 3168 Info.SecondArg = TemplateArgument(OriginalArg.OriginalArgType); 3169 Info.CallArgIndex = OriginalArg.ArgIdx; 3170 return OriginalArg.DecomposedParam ? Sema::TDK_DeducedMismatchNested 3171 : Sema::TDK_DeducedMismatch; 3172 }; 3173 3174 QualType A = OriginalArg.OriginalArgType; 3175 QualType OriginalParamType = OriginalArg.OriginalParamType; 3176 3177 // Check for type equality (top-level cv-qualifiers are ignored). 3178 if (Context.hasSameUnqualifiedType(A, DeducedA)) 3179 return Sema::TDK_Success; 3180 3181 // Strip off references on the argument types; they aren't needed for 3182 // the following checks. 3183 if (const ReferenceType *DeducedARef = DeducedA->getAs<ReferenceType>()) 3184 DeducedA = DeducedARef->getPointeeType(); 3185 if (const ReferenceType *ARef = A->getAs<ReferenceType>()) 3186 A = ARef->getPointeeType(); 3187 3188 // C++ [temp.deduct.call]p4: 3189 // [...] However, there are three cases that allow a difference: 3190 // - If the original P is a reference type, the deduced A (i.e., the 3191 // type referred to by the reference) can be more cv-qualified than 3192 // the transformed A. 3193 if (const ReferenceType *OriginalParamRef 3194 = OriginalParamType->getAs<ReferenceType>()) { 3195 // We don't want to keep the reference around any more. 3196 OriginalParamType = OriginalParamRef->getPointeeType(); 3197 3198 // FIXME: Resolve core issue (no number yet): if the original P is a 3199 // reference type and the transformed A is function type "noexcept F", 3200 // the deduced A can be F. 3201 QualType Tmp; 3202 if (A->isFunctionType() && S.IsFunctionConversion(A, DeducedA, Tmp)) 3203 return Sema::TDK_Success; 3204 3205 Qualifiers AQuals = A.getQualifiers(); 3206 Qualifiers DeducedAQuals = DeducedA.getQualifiers(); 3207 3208 // Under Objective-C++ ARC, the deduced type may have implicitly 3209 // been given strong or (when dealing with a const reference) 3210 // unsafe_unretained lifetime. If so, update the original 3211 // qualifiers to include this lifetime. 3212 if (S.getLangOpts().ObjCAutoRefCount && 3213 ((DeducedAQuals.getObjCLifetime() == Qualifiers::OCL_Strong && 3214 AQuals.getObjCLifetime() == Qualifiers::OCL_None) || 3215 (DeducedAQuals.hasConst() && 3216 DeducedAQuals.getObjCLifetime() == Qualifiers::OCL_ExplicitNone))) { 3217 AQuals.setObjCLifetime(DeducedAQuals.getObjCLifetime()); 3218 } 3219 3220 if (AQuals == DeducedAQuals) { 3221 // Qualifiers match; there's nothing to do. 3222 } else if (!DeducedAQuals.compatiblyIncludes(AQuals)) { 3223 return Failed(); 3224 } else { 3225 // Qualifiers are compatible, so have the argument type adopt the 3226 // deduced argument type's qualifiers as if we had performed the 3227 // qualification conversion. 3228 A = Context.getQualifiedType(A.getUnqualifiedType(), DeducedAQuals); 3229 } 3230 } 3231 3232 // - The transformed A can be another pointer or pointer to member 3233 // type that can be converted to the deduced A via a function pointer 3234 // conversion and/or a qualification conversion. 3235 // 3236 // Also allow conversions which merely strip __attribute__((noreturn)) from 3237 // function types (recursively). 3238 bool ObjCLifetimeConversion = false; 3239 QualType ResultTy; 3240 if ((A->isAnyPointerType() || A->isMemberPointerType()) && 3241 (S.IsQualificationConversion(A, DeducedA, false, 3242 ObjCLifetimeConversion) || 3243 S.IsFunctionConversion(A, DeducedA, ResultTy))) 3244 return Sema::TDK_Success; 3245 3246 // - If P is a class and P has the form simple-template-id, then the 3247 // transformed A can be a derived class of the deduced A. [...] 3248 // [...] Likewise, if P is a pointer to a class of the form 3249 // simple-template-id, the transformed A can be a pointer to a 3250 // derived class pointed to by the deduced A. 3251 if (const PointerType *OriginalParamPtr 3252 = OriginalParamType->getAs<PointerType>()) { 3253 if (const PointerType *DeducedAPtr = DeducedA->getAs<PointerType>()) { 3254 if (const PointerType *APtr = A->getAs<PointerType>()) { 3255 if (A->getPointeeType()->isRecordType()) { 3256 OriginalParamType = OriginalParamPtr->getPointeeType(); 3257 DeducedA = DeducedAPtr->getPointeeType(); 3258 A = APtr->getPointeeType(); 3259 } 3260 } 3261 } 3262 } 3263 3264 if (Context.hasSameUnqualifiedType(A, DeducedA)) 3265 return Sema::TDK_Success; 3266 3267 if (A->isRecordType() && isSimpleTemplateIdType(OriginalParamType) && 3268 S.IsDerivedFrom(Info.getLocation(), A, DeducedA)) 3269 return Sema::TDK_Success; 3270 3271 return Failed(); 3272} 3273 3274/// Find the pack index for a particular parameter index in an instantiation of 3275/// a function template with specific arguments. 3276/// 3277/// \return The pack index for whichever pack produced this parameter, or -1 3278/// if this was not produced by a parameter. Intended to be used as the 3279/// ArgumentPackSubstitutionIndex for further substitutions. 3280// FIXME: We should track this in OriginalCallArgs so we don't need to 3281// reconstruct it here. 3282static unsigned getPackIndexForParam(Sema &S, 3283 FunctionTemplateDecl *FunctionTemplate, 3284 const MultiLevelTemplateArgumentList &Args, 3285 unsigned ParamIdx) { 3286 unsigned Idx = 0; 3287 for (auto *PD : FunctionTemplate->getTemplatedDecl()->parameters()) { 3288 if (PD->isParameterPack()) { 3289 unsigned NumExpansions = 3290 S.getNumArgumentsInExpansion(PD->getType(), Args).getValueOr(1); 3291 if (Idx + NumExpansions > ParamIdx) 3292 return ParamIdx - Idx; 3293 Idx += NumExpansions; 3294 } else { 3295 if (Idx == ParamIdx) 3296 return -1; // Not a pack expansion 3297 ++Idx; 3298 } 3299 } 3300 3301 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-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 3301)
; 3302} 3303 3304/// Finish template argument deduction for a function template, 3305/// checking the deduced template arguments for completeness and forming 3306/// the function template specialization. 3307/// 3308/// \param OriginalCallArgs If non-NULL, the original call arguments against 3309/// which the deduced argument types should be compared. 3310Sema::TemplateDeductionResult Sema::FinishTemplateArgumentDeduction( 3311 FunctionTemplateDecl *FunctionTemplate, 3312 SmallVectorImpl<DeducedTemplateArgument> &Deduced, 3313 unsigned NumExplicitlySpecified, FunctionDecl *&Specialization, 3314 TemplateDeductionInfo &Info, 3315 SmallVectorImpl<OriginalCallArg> const *OriginalCallArgs, 3316 bool PartialOverloading, llvm::function_ref<bool()> CheckNonDependent) { 3317 // Unevaluated SFINAE context. 3318 EnterExpressionEvaluationContext Unevaluated( 3319 *this, Sema::ExpressionEvaluationContext::Unevaluated); 3320 SFINAETrap Trap(*this); 3321 3322 // Enter a new template instantiation context while we instantiate the 3323 // actual function declaration. 3324 SmallVector<TemplateArgument, 4> DeducedArgs(Deduced.begin(), Deduced.end()); 3325 InstantiatingTemplate Inst( 3326 *this, Info.getLocation(), FunctionTemplate, DeducedArgs, 3327 CodeSynthesisContext::DeducedTemplateArgumentSubstitution, Info); 3328 if (Inst.isInvalid()) 3329 return TDK_InstantiationDepth; 3330 3331 ContextRAII SavedContext(*this, FunctionTemplate->getTemplatedDecl()); 3332 3333 // C++ [temp.deduct.type]p2: 3334 // [...] or if any template argument remains neither deduced nor 3335 // explicitly specified, template argument deduction fails. 3336 SmallVector<TemplateArgument, 4> Builder; 3337 if (auto Result = ConvertDeducedTemplateArguments( 3338 *this, FunctionTemplate, /*IsDeduced*/true, Deduced, Info, Builder, 3339 CurrentInstantiationScope, NumExplicitlySpecified, 3340 PartialOverloading)) 3341 return Result; 3342 3343 // C++ [temp.deduct.call]p10: [DR1391] 3344 // If deduction succeeds for all parameters that contain 3345 // template-parameters that participate in template argument deduction, 3346 // and all template arguments are explicitly specified, deduced, or 3347 // obtained from default template arguments, remaining parameters are then 3348 // compared with the corresponding arguments. For each remaining parameter 3349 // P with a type that was non-dependent before substitution of any 3350 // explicitly-specified template arguments, if the corresponding argument 3351 // A cannot be implicitly converted to P, deduction fails. 3352 if (CheckNonDependent()) 3353 return TDK_NonDependentConversionFailure; 3354 3355 // Form the template argument list from the deduced template arguments. 3356 TemplateArgumentList *DeducedArgumentList 3357 = TemplateArgumentList::CreateCopy(Context, Builder); 3358 Info.reset(DeducedArgumentList); 3359 3360 // Substitute the deduced template arguments into the function template 3361 // declaration to produce the function template specialization. 3362 DeclContext *Owner = FunctionTemplate->getDeclContext(); 3363 if (FunctionTemplate->getFriendObjectKind()) 3364 Owner = FunctionTemplate->getLexicalDeclContext(); 3365 MultiLevelTemplateArgumentList SubstArgs(*DeducedArgumentList); 3366 Specialization = cast_or_null<FunctionDecl>( 3367 SubstDecl(FunctionTemplate->getTemplatedDecl(), Owner, SubstArgs)); 3368 if (!Specialization || Specialization->isInvalidDecl()) 3369 return TDK_SubstitutionFailure; 3370 3371 assert(Specialization->getPrimaryTemplate()->getCanonicalDecl() ==((Specialization->getPrimaryTemplate()->getCanonicalDecl
() == FunctionTemplate->getCanonicalDecl()) ? static_cast<
void> (0) : __assert_fail ("Specialization->getPrimaryTemplate()->getCanonicalDecl() == FunctionTemplate->getCanonicalDecl()"
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 3372, __PRETTY_FUNCTION__))
3372 FunctionTemplate->getCanonicalDecl())((Specialization->getPrimaryTemplate()->getCanonicalDecl
() == FunctionTemplate->getCanonicalDecl()) ? static_cast<
void> (0) : __assert_fail ("Specialization->getPrimaryTemplate()->getCanonicalDecl() == FunctionTemplate->getCanonicalDecl()"
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 3372, __PRETTY_FUNCTION__))
; 3373 3374 // If the template argument list is owned by the function template 3375 // specialization, release it. 3376 if (Specialization->getTemplateSpecializationArgs() == DeducedArgumentList && 3377 !Trap.hasErrorOccurred()) 3378 Info.take(); 3379 3380 // There may have been an error that did not prevent us from constructing a 3381 // declaration. Mark the declaration invalid and return with a substitution 3382 // failure. 3383 if (Trap.hasErrorOccurred()) { 3384 Specialization->setInvalidDecl(true); 3385 return TDK_SubstitutionFailure; 3386 } 3387 3388 if (OriginalCallArgs) { 3389 // C++ [temp.deduct.call]p4: 3390 // In general, the deduction process attempts to find template argument 3391 // values that will make the deduced A identical to A (after the type A 3392 // is transformed as described above). [...] 3393 llvm::SmallDenseMap<std::pair<unsigned, QualType>, QualType> DeducedATypes; 3394 for (unsigned I = 0, N = OriginalCallArgs->size(); I != N; ++I) { 3395 OriginalCallArg OriginalArg = (*OriginalCallArgs)[I]; 3396 3397 auto ParamIdx = OriginalArg.ArgIdx; 3398 if (ParamIdx >= Specialization->getNumParams()) 3399 // FIXME: This presumably means a pack ended up smaller than we 3400 // expected while deducing. Should this not result in deduction 3401 // failure? Can it even happen? 3402 continue; 3403 3404 QualType DeducedA; 3405 if (!OriginalArg.DecomposedParam) { 3406 // P is one of the function parameters, just look up its substituted 3407 // type. 3408 DeducedA = Specialization->getParamDecl(ParamIdx)->getType(); 3409 } else { 3410 // P is a decomposed element of a parameter corresponding to a 3411 // braced-init-list argument. Substitute back into P to find the 3412 // deduced A. 3413 QualType &CacheEntry = 3414 DeducedATypes[{ParamIdx, OriginalArg.OriginalParamType}]; 3415 if (CacheEntry.isNull()) { 3416 ArgumentPackSubstitutionIndexRAII PackIndex( 3417 *this, getPackIndexForParam(*this, FunctionTemplate, SubstArgs, 3418 ParamIdx)); 3419 CacheEntry = 3420 SubstType(OriginalArg.OriginalParamType, SubstArgs, 3421 Specialization->getTypeSpecStartLoc(), 3422 Specialization->getDeclName()); 3423 } 3424 DeducedA = CacheEntry; 3425 } 3426 3427 if (auto TDK = 3428 CheckOriginalCallArgDeduction(*this, Info, OriginalArg, DeducedA)) 3429 return TDK; 3430 } 3431 } 3432 3433 // If we suppressed any diagnostics while performing template argument 3434 // deduction, and if we haven't already instantiated this declaration, 3435 // keep track of these diagnostics. They'll be emitted if this specialization 3436 // is actually used. 3437 if (Info.diag_begin() != Info.diag_end()) { 3438 SuppressedDiagnosticsMap::iterator 3439 Pos = SuppressedDiagnostics.find(Specialization->getCanonicalDecl()); 3440 if (Pos == SuppressedDiagnostics.end()) 3441 SuppressedDiagnostics[Specialization->getCanonicalDecl()] 3442 .append(Info.diag_begin(), Info.diag_end()); 3443 } 3444 3445 return TDK_Success; 3446} 3447 3448/// Gets the type of a function for template-argument-deducton 3449/// purposes when it's considered as part of an overload set. 3450static QualType GetTypeOfFunction(Sema &S, const OverloadExpr::FindResult &R, 3451 FunctionDecl *Fn) { 3452 // We may need to deduce the return type of the function now. 3453 if (S.getLangOpts().CPlusPlus14 && Fn->getReturnType()->isUndeducedType() && 3454 S.DeduceReturnType(Fn, R.Expression->getExprLoc(), /*Diagnose*/ false)) 3455 return {}; 3456 3457 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) 3458 if (Method->isInstance()) { 3459 // An instance method that's referenced in a form that doesn't 3460 // look like a member pointer is just invalid. 3461 if (!R.HasFormOfMemberPointer) 3462 return {}; 3463 3464 return S.Context.getMemberPointerType(Fn->getType(), 3465 S.Context.getTypeDeclType(Method->getParent()).getTypePtr()); 3466 } 3467 3468 if (!R.IsAddressOfOperand) return Fn->getType(); 3469 return S.Context.getPointerType(Fn->getType()); 3470} 3471 3472/// Apply the deduction rules for overload sets. 3473/// 3474/// \return the null type if this argument should be treated as an 3475/// undeduced context 3476static QualType 3477ResolveOverloadForDeduction(Sema &S, TemplateParameterList *TemplateParams, 3478 Expr *Arg, QualType ParamType, 3479 bool ParamWasReference) { 3480 3481 OverloadExpr::FindResult R = OverloadExpr::find(Arg); 3482 3483 OverloadExpr *Ovl = R.Expression; 3484 3485 // C++0x [temp.deduct.call]p4 3486 unsigned TDF = 0; 3487 if (ParamWasReference) 3488 TDF |= TDF_ParamWithReferenceType; 3489 if (R.IsAddressOfOperand) 3490 TDF |= TDF_IgnoreQualifiers; 3491 3492 // C++0x [temp.deduct.call]p6: 3493 // When P is a function type, pointer to function type, or pointer 3494 // to member function type: 3495 3496 if (!ParamType->isFunctionType() && 3497 !ParamType->isFunctionPointerType() && 3498 !ParamType->isMemberFunctionPointerType()) { 3499 if (Ovl->hasExplicitTemplateArgs()) { 3500 // But we can still look for an explicit specialization. 3501 if (FunctionDecl *ExplicitSpec 3502 = S.ResolveSingleFunctionTemplateSpecialization(Ovl)) 3503 return GetTypeOfFunction(S, R, ExplicitSpec); 3504 } 3505 3506 DeclAccessPair DAP; 3507 if (FunctionDecl *Viable = 3508 S.resolveAddressOfOnlyViableOverloadCandidate(Arg, DAP)) 3509 return GetTypeOfFunction(S, R, Viable); 3510 3511 return {}; 3512 } 3513 3514 // Gather the explicit template arguments, if any. 3515 TemplateArgumentListInfo ExplicitTemplateArgs; 3516 if (Ovl->hasExplicitTemplateArgs()) 3517 Ovl->copyTemplateArgumentsInto(ExplicitTemplateArgs); 3518 QualType Match; 3519 for (UnresolvedSetIterator I = Ovl->decls_begin(), 3520 E = Ovl->decls_end(); I != E; ++I) { 3521 NamedDecl *D = (*I)->getUnderlyingDecl(); 3522 3523 if (FunctionTemplateDecl *FunTmpl = dyn_cast<FunctionTemplateDecl>(D)) { 3524 // - If the argument is an overload set containing one or more 3525 // function templates, the parameter is treated as a 3526 // non-deduced context. 3527 if (!Ovl->hasExplicitTemplateArgs()) 3528 return {}; 3529 3530 // Otherwise, see if we can resolve a function type 3531 FunctionDecl *Specialization = nullptr; 3532 TemplateDeductionInfo Info(Ovl->getNameLoc()); 3533 if (S.DeduceTemplateArguments(FunTmpl, &ExplicitTemplateArgs, 3534 Specialization, Info)) 3535 continue; 3536 3537 D = Specialization; 3538 } 3539 3540 FunctionDecl *Fn = cast<FunctionDecl>(D); 3541 QualType ArgType = GetTypeOfFunction(S, R, Fn); 3542 if (ArgType.isNull()) continue; 3543 3544 // Function-to-pointer conversion. 3545 if (!ParamWasReference && ParamType->isPointerType() && 3546 ArgType->isFunctionType()) 3547 ArgType = S.Context.getPointerType(ArgType); 3548 3549 // - If the argument is an overload set (not containing function 3550 // templates), trial argument deduction is attempted using each 3551 // of the members of the set. If deduction succeeds for only one 3552 // of the overload set members, that member is used as the 3553 // argument value for the deduction. If deduction succeeds for 3554 // more than one member of the overload set the parameter is 3555 // treated as a non-deduced context. 3556 3557 // We do all of this in a fresh context per C++0x [temp.deduct.type]p2: 3558 // Type deduction is done independently for each P/A pair, and 3559 // the deduced template argument values are then combined. 3560 // So we do not reject deductions which were made elsewhere. 3561 SmallVector<DeducedTemplateArgument, 8> 3562 Deduced(TemplateParams->size()); 3563 TemplateDeductionInfo Info(Ovl->getNameLoc()); 3564 Sema::TemplateDeductionResult Result 3565 = DeduceTemplateArgumentsByTypeMatch(S, TemplateParams, ParamType, 3566 ArgType, Info, Deduced, TDF); 3567 if (Result) continue; 3568 if (!Match.isNull()) 3569 return {}; 3570 Match = ArgType; 3571 } 3572 3573 return Match; 3574} 3575 3576/// Perform the adjustments to the parameter and argument types 3577/// described in C++ [temp.deduct.call]. 3578/// 3579/// \returns true if the caller should not attempt to perform any template 3580/// argument deduction based on this P/A pair because the argument is an 3581/// overloaded function set that could not be resolved. 3582static bool AdjustFunctionParmAndArgTypesForDeduction( 3583 Sema &S, TemplateParameterList *TemplateParams, unsigned FirstInnerIndex, 3584 QualType &ParamType, QualType &ArgType, Expr *Arg, unsigned &TDF) { 3585 // C++0x [temp.deduct.call]p3: 3586 // If P is a cv-qualified type, the top level cv-qualifiers of P's type 3587 // are ignored for type deduction. 3588 if (ParamType.hasQualifiers())
18
Assuming the condition is false
19
Taking false branch
3589 ParamType = ParamType.getUnqualifiedType(); 3590 3591 // [...] If P is a reference type, the type referred to by P is 3592 // used for type deduction. 3593 const ReferenceType *ParamRefType = ParamType->getAs<ReferenceType>();
20
Assuming the object is not a 'ReferenceType'
3594 if (ParamRefType
20.1
'ParamRefType' is null
20.1
'ParamRefType' is null
20.1
'ParamRefType' is null
)
21
Taking false branch
3595 ParamType = ParamRefType->getPointeeType(); 3596 3597 // Overload sets usually make this parameter an undeduced context, 3598 // but there are sometimes special circumstances. Typically 3599 // involving a template-id-expr. 3600 if (ArgType == S.Context.OverloadTy) {
22
Calling 'operator=='
28
Returning from 'operator=='
29
Taking false branch
3601 ArgType = ResolveOverloadForDeduction(S, TemplateParams, 3602 Arg, ParamType, 3603 ParamRefType != nullptr); 3604 if (ArgType.isNull()) 3605 return true; 3606 } 3607 3608 if (ParamRefType
29.1
'ParamRefType' is null
29.1
'ParamRefType' is null
29.1
'ParamRefType' is null
) {
30
Taking false branch
3609 // If the argument has incomplete array type, try to complete its type. 3610 if (ArgType->isIncompleteArrayType()) { 3611 S.completeExprArrayBound(Arg); 3612 ArgType = Arg->getType(); 3613 } 3614 3615 // C++1z [temp.deduct.call]p3: 3616 // If P is a forwarding reference and the argument is an lvalue, the type 3617 // "lvalue reference to A" is used in place of A for type deduction. 3618 if (isForwardingReference(QualType(ParamRefType, 0), FirstInnerIndex) && 3619 Arg->isLValue()) 3620 ArgType = S.Context.getLValueReferenceType(ArgType); 3621 } else { 3622 // C++ [temp.deduct.call]p2: 3623 // If P is not a reference type: 3624 // - If A is an array type, the pointer type produced by the 3625 // array-to-pointer standard conversion (4.2) is used in place of 3626 // A for type deduction; otherwise, 3627 if (ArgType->isArrayType())
31
Taking false branch
3628 ArgType = S.Context.getArrayDecayedType(ArgType); 3629 // - If A is a function type, the pointer type produced by the 3630 // function-to-pointer standard conversion (4.3) is used in place 3631 // of A for type deduction; otherwise, 3632 else if (ArgType->isFunctionType())
32
Taking true branch
3633 ArgType = S.Context.getPointerType(ArgType); 3634 else { 3635 // - If A is a cv-qualified type, the top level cv-qualifiers of A's 3636 // type are ignored for type deduction. 3637 ArgType = ArgType.getUnqualifiedType(); 3638 } 3639 } 3640 3641 // C++0x [temp.deduct.call]p4: 3642 // In general, the deduction process attempts to find template argument 3643 // values that will make the deduced A identical to A (after the type A 3644 // is transformed as described above). [...] 3645 TDF = TDF_SkipNonDependent; 3646 3647 // - If the original P is a reference type, the deduced A (i.e., the 3648 // type referred to by the reference) can be more cv-qualified than 3649 // the transformed A. 3650 if (ParamRefType
32.1
'ParamRefType' is null
32.1
'ParamRefType' is null
32.1
'ParamRefType' is null
)
33
Taking false branch
3651 TDF |= TDF_ParamWithReferenceType; 3652 // - The transformed A can be another pointer or pointer to member 3653 // type that can be converted to the deduced A via a qualification 3654 // conversion (4.4). 3655 if (ArgType->isPointerType() || ArgType->isMemberPointerType() ||
34
Taking false branch
3656 ArgType->isObjCObjectPointerType()) 3657 TDF |= TDF_IgnoreQualifiers; 3658 // - If P is a class and P has the form simple-template-id, then the 3659 // transformed A can be a derived class of the deduced A. Likewise, 3660 // if P is a pointer to a class of the form simple-template-id, the 3661 // transformed A can be a pointer to a derived class pointed to by 3662 // the deduced A. 3663 if (isSimpleTemplateIdType(ParamType) ||
35
Calling 'isSimpleTemplateIdType'
40
Returning from 'isSimpleTemplateIdType'
3664 (isa<PointerType>(ParamType) &&
41
Assuming 'ParamType' is a 'PointerType'
3665 isSimpleTemplateIdType( 3666 ParamType->getAs<PointerType>()->getPointeeType())))
42
Assuming the object is not a 'PointerType'
43
Called C++ object pointer is null
3667 TDF |= TDF_DerivedClass; 3668 3669 return false; 3670} 3671 3672static bool 3673hasDeducibleTemplateParameters(Sema &S, FunctionTemplateDecl *FunctionTemplate, 3674 QualType T); 3675 3676static Sema::TemplateDeductionResult DeduceTemplateArgumentsFromCallArgument( 3677 Sema &S, TemplateParameterList *TemplateParams, unsigned FirstInnerIndex, 3678 QualType ParamType, Expr *Arg, TemplateDeductionInfo &Info, 3679 SmallVectorImpl<DeducedTemplateArgument> &Deduced, 3680 SmallVectorImpl<Sema::OriginalCallArg> &OriginalCallArgs, 3681 bool DecomposedParam, unsigned ArgIdx, unsigned TDF); 3682 3683/// Attempt template argument deduction from an initializer list 3684/// deemed to be an argument in a function call. 3685static Sema::TemplateDeductionResult DeduceFromInitializerList( 3686 Sema &S, TemplateParameterList *TemplateParams, QualType AdjustedParamType, 3687 InitListExpr *ILE, TemplateDeductionInfo &Info, 3688 SmallVectorImpl<DeducedTemplateArgument> &Deduced, 3689 SmallVectorImpl<Sema::OriginalCallArg> &OriginalCallArgs, unsigned ArgIdx, 3690 unsigned TDF) { 3691 // C++ [temp.deduct.call]p1: (CWG 1591) 3692 // If removing references and cv-qualifiers from P gives 3693 // std::initializer_list<P0> or P0[N] for some P0 and N and the argument is 3694 // a non-empty initializer list, then deduction is performed instead for 3695 // each element of the initializer list, taking P0 as a function template 3696 // parameter type and the initializer element as its argument 3697 // 3698 // We've already removed references and cv-qualifiers here. 3699 if (!ILE->getNumInits()) 3700 return Sema::TDK_Success; 3701 3702 QualType ElTy; 3703 auto *ArrTy = S.Context.getAsArrayType(AdjustedParamType); 3704 if (ArrTy) 3705 ElTy = ArrTy->getElementType(); 3706 else if (!S.isStdInitializerList(AdjustedParamType, &ElTy)) { 3707 // Otherwise, an initializer list argument causes the parameter to be 3708 // considered a non-deduced context 3709 return Sema::TDK_Success; 3710 } 3711 3712 // Resolving a core issue: a braced-init-list containing any designators is 3713 // a non-deduced context. 3714 for (Expr *E : ILE->inits()) 3715 if (isa<DesignatedInitExpr>(E)) 3716 return Sema::TDK_Success; 3717 3718 // Deduction only needs to be done for dependent types. 3719 if (ElTy->isDependentType()) { 3720 for (Expr *E : ILE->inits()) { 3721 if (auto Result = DeduceTemplateArgumentsFromCallArgument( 3722 S, TemplateParams, 0, ElTy, E, Info, Deduced, OriginalCallArgs, true, 3723 ArgIdx, TDF)) 3724 return Result; 3725 } 3726 } 3727 3728 // in the P0[N] case, if N is a non-type template parameter, N is deduced 3729 // from the length of the initializer list. 3730 if (auto *DependentArrTy = dyn_cast_or_null<DependentSizedArrayType>(ArrTy)) { 3731 // Determine the array bound is something we can deduce. 3732 if (NonTypeTemplateParmDecl *NTTP = 3733 getDeducedParameterFromExpr(Info, DependentArrTy->getSizeExpr())) { 3734 // We can perform template argument deduction for the given non-type 3735 // template parameter. 3736 // C++ [temp.deduct.type]p13: 3737 // The type of N in the type T[N] is std::size_t. 3738 QualType T = S.Context.getSizeType(); 3739 llvm::APInt Size(S.Context.getIntWidth(T), ILE->getNumInits()); 3740 if (auto Result = DeduceNonTypeTemplateArgument( 3741 S, TemplateParams, NTTP, llvm::APSInt(Size), T, 3742 /*ArrayBound=*/true, Info, Deduced)) 3743 return Result; 3744 } 3745 } 3746 3747 return Sema::TDK_Success; 3748} 3749 3750/// Perform template argument deduction per [temp.deduct.call] for a 3751/// single parameter / argument pair. 3752static Sema::TemplateDeductionResult DeduceTemplateArgumentsFromCallArgument( 3753 Sema &S, TemplateParameterList *TemplateParams, unsigned FirstInnerIndex, 3754 QualType ParamType, Expr *Arg, TemplateDeductionInfo &Info, 3755 SmallVectorImpl<DeducedTemplateArgument> &Deduced, 3756 SmallVectorImpl<Sema::OriginalCallArg> &OriginalCallArgs, 3757 bool DecomposedParam, unsigned ArgIdx, unsigned TDF) { 3758 QualType ArgType = Arg->getType(); 3759 QualType OrigParamType = ParamType; 3760 3761 // If P is a reference type [...] 3762 // If P is a cv-qualified type [...] 3763 if (AdjustFunctionParmAndArgTypesForDeduction(
17
Calling 'AdjustFunctionParmAndArgTypesForDeduction'
3764 S, TemplateParams, FirstInnerIndex, ParamType, ArgType, Arg, TDF)) 3765 return Sema::TDK_Success; 3766 3767 // If [...] the argument is a non-empty initializer list [...] 3768 if (InitListExpr *ILE = dyn_cast<InitListExpr>(Arg)) 3769 return DeduceFromInitializerList(S, TemplateParams, ParamType, ILE, Info, 3770 Deduced, OriginalCallArgs, ArgIdx, TDF); 3771 3772 // [...] the deduction process attempts to find template argument values 3773 // that will make the deduced A identical to A 3774 // 3775 // Keep track of the argument type and corresponding parameter index, 3776 // so we can check for compatibility between the deduced A and A. 3777 OriginalCallArgs.push_back( 3778 Sema::OriginalCallArg(OrigParamType, DecomposedParam, ArgIdx, ArgType)); 3779 return DeduceTemplateArgumentsByTypeMatch(S, TemplateParams, ParamType, 3780 ArgType, Info, Deduced, TDF); 3781} 3782 3783/// Perform template argument deduction from a function call 3784/// (C++ [temp.deduct.call]). 3785/// 3786/// \param FunctionTemplate the function template for which we are performing 3787/// template argument deduction. 3788/// 3789/// \param ExplicitTemplateArgs the explicit template arguments provided 3790/// for this call. 3791/// 3792/// \param Args the function call arguments 3793/// 3794/// \param Specialization if template argument deduction was successful, 3795/// this will be set to the function template specialization produced by 3796/// template argument deduction. 3797/// 3798/// \param Info the argument will be updated to provide additional information 3799/// about template argument deduction. 3800/// 3801/// \param CheckNonDependent A callback to invoke to check conversions for 3802/// non-dependent parameters, between deduction and substitution, per DR1391. 3803/// If this returns true, substitution will be skipped and we return 3804/// TDK_NonDependentConversionFailure. The callback is passed the parameter 3805/// types (after substituting explicit template arguments). 3806/// 3807/// \returns the result of template argument deduction. 3808Sema::TemplateDeductionResult Sema::DeduceTemplateArguments( 3809 FunctionTemplateDecl *FunctionTemplate, 3810 TemplateArgumentListInfo *ExplicitTemplateArgs, ArrayRef<Expr *> Args, 3811 FunctionDecl *&Specialization, TemplateDeductionInfo &Info, 3812 bool PartialOverloading, 3813 llvm::function_ref<bool(ArrayRef<QualType>)> CheckNonDependent) { 3814 if (FunctionTemplate->isInvalidDecl())
1
Assuming the condition is false
2
Taking false branch
3815 return TDK_Invalid; 3816 3817 FunctionDecl *Function = FunctionTemplate->getTemplatedDecl(); 3818 unsigned NumParams = Function->getNumParams(); 3819 3820 unsigned FirstInnerIndex = getFirstInnerIndex(FunctionTemplate); 3821 3822 // C++ [temp.deduct.call]p1: 3823 // Template argument deduction is done by comparing each function template 3824 // parameter type (call it P) with the type of the corresponding argument 3825 // of the call (call it A) as described below. 3826 if (Args.size() < Function->getMinRequiredArguments() && !PartialOverloading)
3
Assuming the condition is false
3827 return TDK_TooFewArguments; 3828 else if (TooManyArguments(NumParams, Args.size(), PartialOverloading)) {
4
Taking false branch
3829 const auto *Proto = Function->getType()->castAs<FunctionProtoType>(); 3830 if (Proto->isTemplateVariadic()) 3831 /* Do nothing */; 3832 else if (!Proto->isVariadic()) 3833 return TDK_TooManyArguments; 3834 } 3835 3836 // The types of the parameters from which we will perform template argument 3837 // deduction. 3838 LocalInstantiationScope InstScope(*this); 3839 TemplateParameterList *TemplateParams 3840 = FunctionTemplate->getTemplateParameters(); 3841 SmallVector<DeducedTemplateArgument, 4> Deduced; 3842 SmallVector<QualType, 8> ParamTypes; 3843 unsigned NumExplicitlySpecified = 0; 3844 if (ExplicitTemplateArgs) {
5
Assuming 'ExplicitTemplateArgs' is null
6
Taking false branch
3845 TemplateDeductionResult Result = 3846 SubstituteExplicitTemplateArguments(FunctionTemplate, 3847 *ExplicitTemplateArgs, 3848 Deduced, 3849 ParamTypes, 3850 nullptr, 3851 Info); 3852 if (Result) 3853 return Result; 3854 3855 NumExplicitlySpecified = Deduced.size(); 3856 } else { 3857 // Just fill in the parameter types from the function declaration. 3858 for (unsigned I = 0; I != NumParams; ++I)
7
Assuming 'I' is equal to 'NumParams'
8
Loop condition is false. Execution continues on line 3862
3859 ParamTypes.push_back(Function->getParamDecl(I)->getType()); 3860 } 3861 3862 SmallVector<OriginalCallArg, 8> OriginalCallArgs; 3863 3864 // Deduce an argument of type ParamType from an expression with index ArgIdx. 3865 auto DeduceCallArgument = [&](QualType ParamType, unsigned ArgIdx) { 3866 // C++ [demp.deduct.call]p1: (DR1391) 3867 // Template argument deduction is done by comparing each function template 3868 // parameter that contains template-parameters that participate in 3869 // template argument deduction ... 3870 if (!hasDeducibleTemplateParameters(*this, FunctionTemplate, ParamType))
15
Taking false branch
3871 return Sema::TDK_Success; 3872 3873 // ... with the type of the corresponding argument 3874 return DeduceTemplateArgumentsFromCallArgument(
16
Calling 'DeduceTemplateArgumentsFromCallArgument'
3875 *this, TemplateParams, FirstInnerIndex, ParamType, Args[ArgIdx], Info, Deduced, 3876 OriginalCallArgs, /*Decomposed*/false, ArgIdx, /*TDF*/ 0); 3877 }; 3878 3879 // Deduce template arguments from the function parameters. 3880 Deduced.resize(TemplateParams->size()); 3881 SmallVector<QualType, 8> ParamTypesForArgChecking; 3882 for (unsigned ParamIdx = 0, NumParamTypes = ParamTypes.size(), ArgIdx = 0;
10
Loop condition is true. Entering loop body
3883 ParamIdx != NumParamTypes; ++ParamIdx) {
9
Assuming 'ParamIdx' is not equal to 'NumParamTypes'
3884 QualType ParamType = ParamTypes[ParamIdx]; 3885 3886 const PackExpansionType *ParamExpansion = 3887 dyn_cast<PackExpansionType>(ParamType); 3888 if (!ParamExpansion
10.1
'ParamExpansion' is null
10.1
'ParamExpansion' is null
10.1
'ParamExpansion' is null
) {
11
Taking true branch
3889 // Simple case: matching a function parameter to a function argument. 3890 if (ArgIdx >= Args.size())
12
Assuming the condition is false
13
Taking false branch
3891 break; 3892 3893 ParamTypesForArgChecking.push_back(ParamType); 3894 if (auto Result = DeduceCallArgument(ParamType, ArgIdx++))
14
Calling 'operator()'
3895 return Result; 3896 3897 continue; 3898 } 3899 3900 QualType ParamPattern = ParamExpansion->getPattern(); 3901 PackDeductionScope PackScope(*this, TemplateParams, Deduced, Info, 3902 ParamPattern); 3903 3904 // C++0x [temp.deduct.call]p1: 3905 // For a function parameter pack that occurs at the end of the 3906 // parameter-declaration-list, the type A of each remaining argument of 3907 // the call is compared with the type P of the declarator-id of the 3908 // function parameter pack. Each comparison deduces template arguments 3909 // for subsequent positions in the template parameter packs expanded by 3910 // the function parameter pack. When a function parameter pack appears 3911 // in a non-deduced context [not at the end of the list], the type of 3912 // that parameter pack is never deduced. 3913 // 3914 // FIXME: The above rule allows the size of the parameter pack to change 3915 // after we skip it (in the non-deduced case). That makes no sense, so 3916 // we instead notionally deduce the pack against N arguments, where N is 3917 // the length of the explicitly-specified pack if it's expanded by the 3918 // parameter pack and 0 otherwise, and we treat each deduction as a 3919 // non-deduced context. 3920 if (ParamIdx + 1 == NumParamTypes || PackScope.hasFixedArity()) { 3921 for (; ArgIdx < Args.size() && PackScope.hasNextElement(); 3922 PackScope.nextPackElement(), ++ArgIdx) { 3923 ParamTypesForArgChecking.push_back(ParamPattern); 3924 if (auto Result = DeduceCallArgument(ParamPattern, ArgIdx)) 3925 return Result; 3926 } 3927 } else { 3928 // If the parameter type contains an explicitly-specified pack that we 3929 // could not expand, skip the number of parameters notionally created 3930 // by the expansion. 3931 Optional<unsigned> NumExpansions = ParamExpansion->getNumExpansions(); 3932 if (NumExpansions && !PackScope.isPartiallyExpanded()) { 3933 for (unsigned I = 0; I != *NumExpansions && ArgIdx < Args.size(); 3934 ++I, ++ArgIdx) { 3935 ParamTypesForArgChecking.push_back(ParamPattern); 3936 // FIXME: Should we add OriginalCallArgs for these? What if the 3937 // corresponding argument is a list? 3938 PackScope.nextPackElement(); 3939 } 3940 } 3941 } 3942 3943 // Build argument packs for each of the parameter packs expanded by this 3944 // pack expansion. 3945 if (auto Result = PackScope.finish()) 3946 return Result; 3947 } 3948 3949 // Capture the context in which the function call is made. This is the context 3950 // that is needed when the accessibility of template arguments is checked. 3951 DeclContext *CallingCtx = CurContext; 3952 3953 return FinishTemplateArgumentDeduction( 3954 FunctionTemplate, Deduced, NumExplicitlySpecified, Specialization, Info, 3955 &OriginalCallArgs, PartialOverloading, [&, CallingCtx]() { 3956 ContextRAII SavedContext(*this, CallingCtx); 3957 return CheckNonDependent(ParamTypesForArgChecking); 3958 }); 3959} 3960 3961QualType Sema::adjustCCAndNoReturn(QualType ArgFunctionType, 3962 QualType FunctionType, 3963 bool AdjustExceptionSpec) { 3964 if (ArgFunctionType.isNull()) 3965 return ArgFunctionType; 3966 3967 const auto *FunctionTypeP = FunctionType->castAs<FunctionProtoType>(); 3968 const auto *ArgFunctionTypeP = ArgFunctionType->castAs<FunctionProtoType>(); 3969 FunctionProtoType::ExtProtoInfo EPI = ArgFunctionTypeP->getExtProtoInfo(); 3970 bool Rebuild = false; 3971 3972 CallingConv CC = FunctionTypeP->getCallConv(); 3973 if (EPI.ExtInfo.getCC() != CC) { 3974 EPI.ExtInfo = EPI.ExtInfo.withCallingConv(CC); 3975 Rebuild = true; 3976 } 3977 3978 bool NoReturn = FunctionTypeP->getNoReturnAttr(); 3979 if (EPI.ExtInfo.getNoReturn() != NoReturn) { 3980 EPI.ExtInfo = EPI.ExtInfo.withNoReturn(NoReturn); 3981 Rebuild = true; 3982 } 3983 3984 if (AdjustExceptionSpec && (FunctionTypeP->hasExceptionSpec() || 3985 ArgFunctionTypeP->hasExceptionSpec())) { 3986 EPI.ExceptionSpec = FunctionTypeP->getExtProtoInfo().ExceptionSpec; 3987 Rebuild = true; 3988 } 3989 3990 if (!Rebuild) 3991 return ArgFunctionType; 3992 3993 return Context.getFunctionType(ArgFunctionTypeP->getReturnType(), 3994 ArgFunctionTypeP->getParamTypes(), EPI); 3995} 3996 3997/// Deduce template arguments when taking the address of a function 3998/// template (C++ [temp.deduct.funcaddr]) or matching a specialization to 3999/// a template. 4000/// 4001/// \param FunctionTemplate the function template for which we are performing 4002/// template argument deduction. 4003/// 4004/// \param ExplicitTemplateArgs the explicitly-specified template 4005/// arguments. 4006/// 4007/// \param ArgFunctionType the function type that will be used as the 4008/// "argument" type (A) when performing template argument deduction from the 4009/// function template's function type. This type may be NULL, if there is no 4010/// argument type to compare against, in C++0x [temp.arg.explicit]p3. 4011/// 4012/// \param Specialization if template argument deduction was successful, 4013/// this will be set to the function template specialization produced by 4014/// template argument deduction. 4015/// 4016/// \param Info the argument will be updated to provide additional information 4017/// about template argument deduction. 4018/// 4019/// \param IsAddressOfFunction If \c true, we are deducing as part of taking 4020/// the address of a function template per [temp.deduct.funcaddr] and 4021/// [over.over]. If \c false, we are looking up a function template 4022/// specialization based on its signature, per [temp.deduct.decl]. 4023/// 4024/// \returns the result of template argument deduction. 4025Sema::TemplateDeductionResult Sema::DeduceTemplateArguments( 4026 FunctionTemplateDecl *FunctionTemplate, 4027 TemplateArgumentListInfo *ExplicitTemplateArgs, QualType ArgFunctionType, 4028 FunctionDecl *&Specialization, TemplateDeductionInfo &Info, 4029 bool IsAddressOfFunction) { 4030 if (FunctionTemplate->isInvalidDecl()) 4031 return TDK_Invalid; 4032 4033 FunctionDecl *Function = FunctionTemplate->getTemplatedDecl(); 4034 TemplateParameterList *TemplateParams 4035 = FunctionTemplate->getTemplateParameters(); 4036 QualType FunctionType = Function->getType(); 4037 4038 // Substitute any explicit template arguments. 4039 LocalInstantiationScope InstScope(*this); 4040 SmallVector<DeducedTemplateArgument, 4> Deduced; 4041 unsigned NumExplicitlySpecified = 0; 4042 SmallVector<QualType, 4> ParamTypes; 4043 if (ExplicitTemplateArgs) { 4044 if (TemplateDeductionResult Result 4045 = SubstituteExplicitTemplateArguments(FunctionTemplate, 4046 *ExplicitTemplateArgs, 4047 Deduced, ParamTypes, 4048 &FunctionType, Info)) 4049 return Result; 4050 4051 NumExplicitlySpecified = Deduced.size(); 4052 } 4053 4054 // When taking the address of a function, we require convertibility of 4055 // the resulting function type. Otherwise, we allow arbitrary mismatches 4056 // of calling convention and noreturn. 4057 if (!IsAddressOfFunction) 4058 ArgFunctionType = adjustCCAndNoReturn(ArgFunctionType, FunctionType, 4059 /*AdjustExceptionSpec*/false); 4060 4061 // Unevaluated SFINAE context. 4062 EnterExpressionEvaluationContext Unevaluated( 4063 *this, Sema::ExpressionEvaluationContext::Unevaluated); 4064 SFINAETrap Trap(*this); 4065 4066 Deduced.resize(TemplateParams->size()); 4067 4068 // If the function has a deduced return type, substitute it for a dependent 4069 // type so that we treat it as a non-deduced context in what follows. If we 4070 // are looking up by signature, the signature type should also have a deduced 4071 // return type, which we instead expect to exactly match. 4072 bool HasDeducedReturnType = false; 4073 if (getLangOpts().CPlusPlus14 && IsAddressOfFunction && 4074 Function->getReturnType()->getContainedAutoType()) { 4075 FunctionType = SubstAutoType(FunctionType, Context.DependentTy); 4076 HasDeducedReturnType = true; 4077 } 4078 4079 if (!ArgFunctionType.isNull()) { 4080 unsigned TDF = 4081 TDF_TopLevelParameterTypeList | TDF_AllowCompatibleFunctionType; 4082 // Deduce template arguments from the function type. 4083 if (TemplateDeductionResult Result 4084 = DeduceTemplateArgumentsByTypeMatch(*this, TemplateParams, 4085 FunctionType, ArgFunctionType, 4086 Info, Deduced, TDF)) 4087 return Result; 4088 } 4089 4090 if (TemplateDeductionResult Result 4091 = FinishTemplateArgumentDeduction(FunctionTemplate, Deduced, 4092 NumExplicitlySpecified, 4093 Specialization, Info)) 4094 return Result; 4095 4096 // If the function has a deduced return type, deduce it now, so we can check 4097 // that the deduced function type matches the requested type. 4098 if (HasDeducedReturnType && 4099 Specialization->getReturnType()->isUndeducedType() && 4100 DeduceReturnType(Specialization, Info.getLocation(), false)) 4101 return TDK_MiscellaneousDeductionFailure; 4102 4103 // If the function has a dependent exception specification, resolve it now, 4104 // so we can check that the exception specification matches. 4105 auto *SpecializationFPT = 4106 Specialization->getType()->castAs<FunctionProtoType>(); 4107 if (getLangOpts().CPlusPlus17 && 4108 isUnresolvedExceptionSpec(SpecializationFPT->getExceptionSpecType()) && 4109 !ResolveExceptionSpec(Info.getLocation(), SpecializationFPT)) 4110 return TDK_MiscellaneousDeductionFailure; 4111 4112 // Adjust the exception specification of the argument to match the 4113 // substituted and resolved type we just formed. (Calling convention and 4114 // noreturn can't be dependent, so we don't actually need this for them 4115 // right now.) 4116 QualType SpecializationType = Specialization->getType(); 4117 if (!IsAddressOfFunction) 4118 ArgFunctionType = adjustCCAndNoReturn(ArgFunctionType, SpecializationType, 4119 /*AdjustExceptionSpec*/true); 4120 4121 // If the requested function type does not match the actual type of the 4122 // specialization with respect to arguments of compatible pointer to function 4123 // types, template argument deduction fails. 4124 if (!ArgFunctionType.isNull()) { 4125 if (IsAddressOfFunction && 4126 !isSameOrCompatibleFunctionType( 4127 Context.getCanonicalType(SpecializationType), 4128 Context.getCanonicalType(ArgFunctionType))) 4129 return TDK_MiscellaneousDeductionFailure; 4130 4131 if (!IsAddressOfFunction && 4132 !Context.hasSameType(SpecializationType, ArgFunctionType)) 4133 return TDK_MiscellaneousDeductionFailure; 4134 } 4135 4136 return TDK_Success; 4137} 4138 4139/// Deduce template arguments for a templated conversion 4140/// function (C++ [temp.deduct.conv]) and, if successful, produce a 4141/// conversion function template specialization. 4142Sema::TemplateDeductionResult 4143Sema::DeduceTemplateArguments(FunctionTemplateDecl *ConversionTemplate, 4144 QualType ToType, 4145 CXXConversionDecl *&Specialization, 4146 TemplateDeductionInfo &Info) { 4147 if (ConversionTemplate->isInvalidDecl()) 4148 return TDK_Invalid; 4149 4150 CXXConversionDecl *ConversionGeneric 4151 = cast<CXXConversionDecl>(ConversionTemplate->getTemplatedDecl()); 4152 4153 QualType FromType = ConversionGeneric->getConversionType(); 4154 4155 // Canonicalize the types for deduction. 4156 QualType P = Context.getCanonicalType(FromType); 4157 QualType A = Context.getCanonicalType(ToType); 4158 4159 // C++0x [temp.deduct.conv]p2: 4160 // If P is a reference type, the type referred to by P is used for 4161 // type deduction. 4162 if (const ReferenceType *PRef = P->getAs<ReferenceType>()) 4163 P = PRef->getPointeeType(); 4164 4165 // C++0x [temp.deduct.conv]p4: 4166 // [...] If A is a reference type, the type referred to by A is used 4167 // for type deduction. 4168 if (const ReferenceType *ARef = A->getAs<ReferenceType>()) { 4169 A = ARef->getPointeeType(); 4170 // We work around a defect in the standard here: cv-qualifiers are also 4171 // removed from P and A in this case, unless P was a reference type. This 4172 // seems to mostly match what other compilers are doing. 4173 if (!FromType->getAs<ReferenceType>()) { 4174 A = A.getUnqualifiedType(); 4175 P = P.getUnqualifiedType(); 4176 } 4177 4178 // C++ [temp.deduct.conv]p3: 4179 // 4180 // If A is not a reference type: 4181 } else { 4182 assert(!A->isReferenceType() && "Reference types were handled above")((!A->isReferenceType() && "Reference types were handled above"
) ? static_cast<void> (0) : __assert_fail ("!A->isReferenceType() && \"Reference types were handled above\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 4182, __PRETTY_FUNCTION__))
; 4183 4184 // - If P is an array type, the pointer type produced by the 4185 // array-to-pointer standard conversion (4.2) is used in place 4186 // of P for type deduction; otherwise, 4187 if (P->isArrayType()) 4188 P = Context.getArrayDecayedType(P); 4189 // - If P is a function type, the pointer type produced by the 4190 // function-to-pointer standard conversion (4.3) is used in 4191 // place of P for type deduction; otherwise, 4192 else if (P->isFunctionType()) 4193 P = Context.getPointerType(P); 4194 // - If P is a cv-qualified type, the top level cv-qualifiers of 4195 // P's type are ignored for type deduction. 4196 else 4197 P = P.getUnqualifiedType(); 4198 4199 // C++0x [temp.deduct.conv]p4: 4200 // If A is a cv-qualified type, the top level cv-qualifiers of A's 4201 // type are ignored for type deduction. If A is a reference type, the type 4202 // referred to by A is used for type deduction. 4203 A = A.getUnqualifiedType(); 4204 } 4205 4206 // Unevaluated SFINAE context. 4207 EnterExpressionEvaluationContext Unevaluated( 4208 *this, Sema::ExpressionEvaluationContext::Unevaluated); 4209 SFINAETrap Trap(*this); 4210 4211 // C++ [temp.deduct.conv]p1: 4212 // Template argument deduction is done by comparing the return 4213 // type of the template conversion function (call it P) with the 4214 // type that is required as the result of the conversion (call it 4215 // A) as described in 14.8.2.4. 4216 TemplateParameterList *TemplateParams 4217 = ConversionTemplate->getTemplateParameters(); 4218 SmallVector<DeducedTemplateArgument, 4> Deduced; 4219 Deduced.resize(TemplateParams->size()); 4220 4221 // C++0x [temp.deduct.conv]p4: 4222 // In general, the deduction process attempts to find template 4223 // argument values that will make the deduced A identical to 4224 // A. However, there are two cases that allow a difference: 4225 unsigned TDF = 0; 4226 // - If the original A is a reference type, A can be more 4227 // cv-qualified than the deduced A (i.e., the type referred to 4228 // by the reference) 4229 if (ToType->isReferenceType()) 4230 TDF |= TDF_ArgWithReferenceType; 4231 // - The deduced A can be another pointer or pointer to member 4232 // type that can be converted to A via a qualification 4233 // conversion. 4234 // 4235 // (C++0x [temp.deduct.conv]p6 clarifies that this only happens when 4236 // both P and A are pointers or member pointers. In this case, we 4237 // just ignore cv-qualifiers completely). 4238 if ((P->isPointerType() && A->isPointerType()) || 4239 (P->isMemberPointerType() && A->isMemberPointerType())) 4240 TDF |= TDF_IgnoreQualifiers; 4241 if (TemplateDeductionResult Result 4242 = DeduceTemplateArgumentsByTypeMatch(*this, TemplateParams, 4243 P, A, Info, Deduced, TDF)) 4244 return Result; 4245 4246 // Create an Instantiation Scope for finalizing the operator. 4247 LocalInstantiationScope InstScope(*this); 4248 // Finish template argument deduction. 4249 FunctionDecl *ConversionSpecialized = nullptr; 4250 TemplateDeductionResult Result 4251 = FinishTemplateArgumentDeduction(ConversionTemplate, Deduced, 0, 4252 ConversionSpecialized, Info); 4253 Specialization = cast_or_null<CXXConversionDecl>(ConversionSpecialized); 4254 return Result; 4255} 4256 4257/// Deduce template arguments for a function template when there is 4258/// nothing to deduce against (C++0x [temp.arg.explicit]p3). 4259/// 4260/// \param FunctionTemplate the function template for which we are performing 4261/// template argument deduction. 4262/// 4263/// \param ExplicitTemplateArgs the explicitly-specified template 4264/// arguments. 4265/// 4266/// \param Specialization if template argument deduction was successful, 4267/// this will be set to the function template specialization produced by 4268/// template argument deduction. 4269/// 4270/// \param Info the argument will be updated to provide additional information 4271/// about template argument deduction. 4272/// 4273/// \param IsAddressOfFunction If \c true, we are deducing as part of taking 4274/// the address of a function template in a context where we do not have a 4275/// target type, per [over.over]. If \c false, we are looking up a function 4276/// template specialization based on its signature, which only happens when 4277/// deducing a function parameter type from an argument that is a template-id 4278/// naming a function template specialization. 4279/// 4280/// \returns the result of template argument deduction. 4281Sema::TemplateDeductionResult Sema::DeduceTemplateArguments( 4282 FunctionTemplateDecl *FunctionTemplate, 4283 TemplateArgumentListInfo *ExplicitTemplateArgs, 4284 FunctionDecl *&Specialization, TemplateDeductionInfo &Info, 4285 bool IsAddressOfFunction) { 4286 return DeduceTemplateArguments(FunctionTemplate, ExplicitTemplateArgs, 4287 QualType(), Specialization, Info, 4288 IsAddressOfFunction); 4289} 4290 4291namespace { 4292 struct DependentAuto { bool IsPack; }; 4293 4294 /// Substitute the 'auto' specifier or deduced template specialization type 4295 /// specifier within a type for a given replacement type. 4296 class SubstituteDeducedTypeTransform : 4297 public TreeTransform<SubstituteDeducedTypeTransform> { 4298 QualType Replacement; 4299 bool ReplacementIsPack; 4300 bool UseTypeSugar; 4301 4302 public: 4303 SubstituteDeducedTypeTransform(Sema &SemaRef, DependentAuto DA) 4304 : TreeTransform<SubstituteDeducedTypeTransform>(SemaRef), Replacement(), 4305 ReplacementIsPack(DA.IsPack), UseTypeSugar(true) {} 4306 4307 SubstituteDeducedTypeTransform(Sema &SemaRef, QualType Replacement, 4308 bool UseTypeSugar = true) 4309 : TreeTransform<SubstituteDeducedTypeTransform>(SemaRef), 4310 Replacement(Replacement), ReplacementIsPack(false), 4311 UseTypeSugar(UseTypeSugar) {} 4312 4313 QualType TransformDesugared(TypeLocBuilder &TLB, DeducedTypeLoc TL) { 4314 assert(isa<TemplateTypeParmType>(Replacement) &&((isa<TemplateTypeParmType>(Replacement) && "unexpected unsugared replacement kind"
) ? static_cast<void> (0) : __assert_fail ("isa<TemplateTypeParmType>(Replacement) && \"unexpected unsugared replacement kind\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 4315, __PRETTY_FUNCTION__))
4315 "unexpected unsugared replacement kind")((isa<TemplateTypeParmType>(Replacement) && "unexpected unsugared replacement kind"
) ? static_cast<void> (0) : __assert_fail ("isa<TemplateTypeParmType>(Replacement) && \"unexpected unsugared replacement kind\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 4315, __PRETTY_FUNCTION__))
; 4316 QualType Result = Replacement; 4317 TemplateTypeParmTypeLoc NewTL = TLB.push<TemplateTypeParmTypeLoc>(Result); 4318 NewTL.setNameLoc(TL.getNameLoc()); 4319 return Result; 4320 } 4321 4322 QualType TransformAutoType(TypeLocBuilder &TLB, AutoTypeLoc TL) { 4323 // If we're building the type pattern to deduce against, don't wrap the 4324 // substituted type in an AutoType. Certain template deduction rules 4325 // apply only when a template type parameter appears directly (and not if 4326 // the parameter is found through desugaring). For instance: 4327 // auto &&lref = lvalue; 4328 // must transform into "rvalue reference to T" not "rvalue reference to 4329 // auto type deduced as T" in order for [temp.deduct.call]p3 to apply. 4330 // 4331 // FIXME: Is this still necessary? 4332 if (!UseTypeSugar) 4333 return TransformDesugared(TLB, TL); 4334 4335 QualType Result = SemaRef.Context.getAutoType( 4336 Replacement, TL.getTypePtr()->getKeyword(), Replacement.isNull(), 4337 ReplacementIsPack); 4338 auto NewTL = TLB.push<AutoTypeLoc>(Result); 4339 NewTL.setNameLoc(TL.getNameLoc()); 4340 return Result; 4341 } 4342 4343 QualType TransformDeducedTemplateSpecializationType( 4344 TypeLocBuilder &TLB, DeducedTemplateSpecializationTypeLoc TL) { 4345 if (!UseTypeSugar) 4346 return TransformDesugared(TLB, TL); 4347 4348 QualType Result = SemaRef.Context.getDeducedTemplateSpecializationType( 4349 TL.getTypePtr()->getTemplateName(), 4350 Replacement, Replacement.isNull()); 4351 auto NewTL = TLB.push<DeducedTemplateSpecializationTypeLoc>(Result); 4352 NewTL.setNameLoc(TL.getNameLoc()); 4353 return Result; 4354 } 4355 4356 ExprResult TransformLambdaExpr(LambdaExpr *E) { 4357 // Lambdas never need to be transformed. 4358 return E; 4359 } 4360 4361 QualType Apply(TypeLoc TL) { 4362 // Create some scratch storage for the transformed type locations. 4363 // FIXME: We're just going to throw this information away. Don't build it. 4364 TypeLocBuilder TLB; 4365 TLB.reserve(TL.getFullDataSize()); 4366 return TransformType(TLB, TL); 4367 } 4368 }; 4369 4370} // namespace 4371 4372Sema::DeduceAutoResult 4373Sema::DeduceAutoType(TypeSourceInfo *Type, Expr *&Init, QualType &Result, 4374 Optional<unsigned> DependentDeductionDepth) { 4375 return DeduceAutoType(Type->getTypeLoc(), Init, Result, 4376 DependentDeductionDepth); 4377} 4378 4379/// Attempt to produce an informative diagostic explaining why auto deduction 4380/// failed. 4381/// \return \c true if diagnosed, \c false if not. 4382static bool diagnoseAutoDeductionFailure(Sema &S, 4383 Sema::TemplateDeductionResult TDK, 4384 TemplateDeductionInfo &Info, 4385 ArrayRef<SourceRange> Ranges) { 4386 switch (TDK) { 4387 case Sema::TDK_Inconsistent: { 4388 // Inconsistent deduction means we were deducing from an initializer list. 4389 auto D = S.Diag(Info.getLocation(), diag::err_auto_inconsistent_deduction); 4390 D << Info.FirstArg << Info.SecondArg; 4391 for (auto R : Ranges) 4392 D << R; 4393 return true; 4394 } 4395 4396 // FIXME: Are there other cases for which a custom diagnostic is more useful 4397 // than the basic "types don't match" diagnostic? 4398 4399 default: 4400 return false; 4401 } 4402} 4403 4404/// Deduce the type for an auto type-specifier (C++11 [dcl.spec.auto]p6) 4405/// 4406/// Note that this is done even if the initializer is dependent. (This is 4407/// necessary to support partial ordering of templates using 'auto'.) 4408/// A dependent type will be produced when deducing from a dependent type. 4409/// 4410/// \param Type the type pattern using the auto type-specifier. 4411/// \param Init the initializer for the variable whose type is to be deduced. 4412/// \param Result if type deduction was successful, this will be set to the 4413/// deduced type. 4414/// \param DependentDeductionDepth Set if we should permit deduction in 4415/// dependent cases. This is necessary for template partial ordering with 4416/// 'auto' template parameters. The value specified is the template 4417/// parameter depth at which we should perform 'auto' deduction. 4418Sema::DeduceAutoResult 4419Sema::DeduceAutoType(TypeLoc Type, Expr *&Init, QualType &Result, 4420 Optional<unsigned> DependentDeductionDepth) { 4421 if (Init->getType()->isNonOverloadPlaceholderType()) { 4422 ExprResult NonPlaceholder = CheckPlaceholderExpr(Init); 4423 if (NonPlaceholder.isInvalid()) 4424 return DAR_FailedAlreadyDiagnosed; 4425 Init = NonPlaceholder.get(); 4426 } 4427 4428 DependentAuto DependentResult = { 4429 /*.IsPack = */ (bool)Type.getAs<PackExpansionTypeLoc>()}; 4430 4431 if (!DependentDeductionDepth && 4432 (Type.getType()->isDependentType() || Init->isTypeDependent())) { 4433 Result = SubstituteDeducedTypeTransform(*this, DependentResult).Apply(Type); 4434 assert(!Result.isNull() && "substituting DependentTy can't fail")((!Result.isNull() && "substituting DependentTy can't fail"
) ? static_cast<void> (0) : __assert_fail ("!Result.isNull() && \"substituting DependentTy can't fail\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 4434, __PRETTY_FUNCTION__))
; 4435 return DAR_Succeeded; 4436 } 4437 4438 // Find the depth of template parameter to synthesize. 4439 unsigned Depth = DependentDeductionDepth.getValueOr(0); 4440 4441 // If this is a 'decltype(auto)' specifier, do the decltype dance. 4442 // Since 'decltype(auto)' can only occur at the top of the type, we 4443 // don't need to go digging for it. 4444 if (const AutoType *AT = Type.getType()->getAs<AutoType>()) { 4445 if (AT->isDecltypeAuto()) { 4446 if (isa<InitListExpr>(Init)) { 4447 Diag(Init->getBeginLoc(), diag::err_decltype_auto_initializer_list); 4448 return DAR_FailedAlreadyDiagnosed; 4449 } 4450 4451 ExprResult ER = CheckPlaceholderExpr(Init); 4452 if (ER.isInvalid()) 4453 return DAR_FailedAlreadyDiagnosed; 4454 Init = ER.get(); 4455 QualType Deduced = BuildDecltypeType(Init, Init->getBeginLoc(), false); 4456 if (Deduced.isNull()) 4457 return DAR_FailedAlreadyDiagnosed; 4458 // FIXME: Support a non-canonical deduced type for 'auto'. 4459 Deduced = Context.getCanonicalType(Deduced); 4460 Result = SubstituteDeducedTypeTransform(*this, Deduced).Apply(Type); 4461 if (Result.isNull()) 4462 return DAR_FailedAlreadyDiagnosed; 4463 return DAR_Succeeded; 4464 } else if (!getLangOpts().CPlusPlus) { 4465 if (isa<InitListExpr>(Init)) { 4466 Diag(Init->getBeginLoc(), diag::err_auto_init_list_from_c); 4467 return DAR_FailedAlreadyDiagnosed; 4468 } 4469 } 4470 } 4471 4472 SourceLocation Loc = Init->getExprLoc(); 4473 4474 LocalInstantiationScope InstScope(*this); 4475 4476 // Build template<class TemplParam> void Func(FuncParam); 4477 TemplateTypeParmDecl *TemplParam = TemplateTypeParmDecl::Create( 4478 Context, nullptr, SourceLocation(), Loc, Depth, 0, nullptr, false, false); 4479 QualType TemplArg = QualType(TemplParam->getTypeForDecl(), 0); 4480 NamedDecl *TemplParamPtr = TemplParam; 4481 FixedSizeTemplateParameterListStorage<1, false> TemplateParamsSt( 4482 Loc, Loc, TemplParamPtr, Loc, nullptr); 4483 4484 QualType FuncParam = 4485 SubstituteDeducedTypeTransform(*this, TemplArg, /*UseTypeSugar*/false) 4486 .Apply(Type); 4487 assert(!FuncParam.isNull() &&((!FuncParam.isNull() && "substituting template parameter for 'auto' failed"
) ? static_cast<void> (0) : __assert_fail ("!FuncParam.isNull() && \"substituting template parameter for 'auto' failed\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 4488, __PRETTY_FUNCTION__))
4488 "substituting template parameter for 'auto' failed")((!FuncParam.isNull() && "substituting template parameter for 'auto' failed"
) ? static_cast<void> (0) : __assert_fail ("!FuncParam.isNull() && \"substituting template parameter for 'auto' failed\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 4488, __PRETTY_FUNCTION__))
; 4489 4490 // Deduce type of TemplParam in Func(Init) 4491 SmallVector<DeducedTemplateArgument, 1> Deduced; 4492 Deduced.resize(1); 4493 4494 TemplateDeductionInfo Info(Loc, Depth); 4495 4496 // If deduction failed, don't diagnose if the initializer is dependent; it 4497 // might acquire a matching type in the instantiation. 4498 auto DeductionFailed = [&](TemplateDeductionResult TDK, 4499 ArrayRef<SourceRange> Ranges) -> DeduceAutoResult { 4500 if (Init->isTypeDependent()) { 4501 Result = 4502 SubstituteDeducedTypeTransform(*this, DependentResult).Apply(Type); 4503 assert(!Result.isNull() && "substituting DependentTy can't fail")((!Result.isNull() && "substituting DependentTy can't fail"
) ? static_cast<void> (0) : __assert_fail ("!Result.isNull() && \"substituting DependentTy can't fail\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 4503, __PRETTY_FUNCTION__))
; 4504 return DAR_Succeeded; 4505 } 4506 if (diagnoseAutoDeductionFailure(*this, TDK, Info, Ranges)) 4507 return DAR_FailedAlreadyDiagnosed; 4508 return DAR_Failed; 4509 }; 4510 4511 SmallVector<OriginalCallArg, 4> OriginalCallArgs; 4512 4513 InitListExpr *InitList = dyn_cast<InitListExpr>(Init); 4514 if (InitList) { 4515 // Notionally, we substitute std::initializer_list<T> for 'auto' and deduce 4516 // against that. Such deduction only succeeds if removing cv-qualifiers and 4517 // references results in std::initializer_list<T>. 4518 if (!Type.getType().getNonReferenceType()->getAs<AutoType>()) 4519 return DAR_Failed; 4520 4521 // Resolving a core issue: a braced-init-list containing any designators is 4522 // a non-deduced context. 4523 for (Expr *E : InitList->inits()) 4524 if (isa<DesignatedInitExpr>(E)) 4525 return DAR_Failed; 4526 4527 SourceRange DeducedFromInitRange; 4528 for (unsigned i = 0, e = InitList->getNumInits(); i < e; ++i) { 4529 Expr *Init = InitList->getInit(i); 4530 4531 if (auto TDK = DeduceTemplateArgumentsFromCallArgument( 4532 *this, TemplateParamsSt.get(), 0, TemplArg, Init, 4533 Info, Deduced, OriginalCallArgs, /*Decomposed*/ true, 4534 /*ArgIdx*/ 0, /*TDF*/ 0)) 4535 return DeductionFailed(TDK, {DeducedFromInitRange, 4536 Init->getSourceRange()}); 4537 4538 if (DeducedFromInitRange.isInvalid() && 4539 Deduced[0].getKind() != TemplateArgument::Null) 4540 DeducedFromInitRange = Init->getSourceRange(); 4541 } 4542 } else { 4543 if (!getLangOpts().CPlusPlus && Init->refersToBitField()) { 4544 Diag(Loc, diag::err_auto_bitfield); 4545 return DAR_FailedAlreadyDiagnosed; 4546 } 4547 4548 if (auto TDK = DeduceTemplateArgumentsFromCallArgument( 4549 *this, TemplateParamsSt.get(), 0, FuncParam, Init, Info, Deduced, 4550 OriginalCallArgs, /*Decomposed*/ false, /*ArgIdx*/ 0, /*TDF*/ 0)) 4551 return DeductionFailed(TDK, {}); 4552 } 4553 4554 // Could be null if somehow 'auto' appears in a non-deduced context. 4555 if (Deduced[0].getKind() != TemplateArgument::Type) 4556 return DeductionFailed(TDK_Incomplete, {}); 4557 4558 QualType DeducedType = Deduced[0].getAsType(); 4559 4560 if (InitList) { 4561 DeducedType = BuildStdInitializerList(DeducedType, Loc); 4562 if (DeducedType.isNull()) 4563 return DAR_FailedAlreadyDiagnosed; 4564 } 4565 4566 Result = SubstituteDeducedTypeTransform(*this, DeducedType).Apply(Type); 4567 if (Result.isNull()) 4568 return DAR_FailedAlreadyDiagnosed; 4569 4570 // Check that the deduced argument type is compatible with the original 4571 // argument type per C++ [temp.deduct.call]p4. 4572 QualType DeducedA = InitList ? Deduced[0].getAsType() : Result; 4573 for (const OriginalCallArg &OriginalArg : OriginalCallArgs) { 4574 assert((bool)InitList == OriginalArg.DecomposedParam &&(((bool)InitList == OriginalArg.DecomposedParam && "decomposed non-init-list in auto deduction?"
) ? static_cast<void> (0) : __assert_fail ("(bool)InitList == OriginalArg.DecomposedParam && \"decomposed non-init-list in auto deduction?\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 4575, __PRETTY_FUNCTION__))
4575 "decomposed non-init-list in auto deduction?")(((bool)InitList == OriginalArg.DecomposedParam && "decomposed non-init-list in auto deduction?"
) ? static_cast<void> (0) : __assert_fail ("(bool)InitList == OriginalArg.DecomposedParam && \"decomposed non-init-list in auto deduction?\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 4575, __PRETTY_FUNCTION__))
; 4576 if (auto TDK = 4577 CheckOriginalCallArgDeduction(*this, Info, OriginalArg, DeducedA)) { 4578 Result = QualType(); 4579 return DeductionFailed(TDK, {}); 4580 } 4581 } 4582 4583 return DAR_Succeeded; 4584} 4585 4586QualType Sema::SubstAutoType(QualType TypeWithAuto, 4587 QualType TypeToReplaceAuto) { 4588 if (TypeToReplaceAuto->isDependentType()) 4589 return SubstituteDeducedTypeTransform( 4590 *this, DependentAuto{ 4591 TypeToReplaceAuto->containsUnexpandedParameterPack()}) 4592 .TransformType(TypeWithAuto); 4593 return SubstituteDeducedTypeTransform(*this, TypeToReplaceAuto) 4594 .TransformType(TypeWithAuto); 4595} 4596 4597TypeSourceInfo *Sema::SubstAutoTypeSourceInfo(TypeSourceInfo *TypeWithAuto, 4598 QualType TypeToReplaceAuto) { 4599 if (TypeToReplaceAuto->isDependentType()) 4600 return SubstituteDeducedTypeTransform( 4601 *this, 4602 DependentAuto{ 4603 TypeToReplaceAuto->containsUnexpandedParameterPack()}) 4604 .TransformType(TypeWithAuto); 4605 return SubstituteDeducedTypeTransform(*this, TypeToReplaceAuto) 4606 .TransformType(TypeWithAuto); 4607} 4608 4609QualType Sema::ReplaceAutoType(QualType TypeWithAuto, 4610 QualType TypeToReplaceAuto) { 4611 return SubstituteDeducedTypeTransform(*this, TypeToReplaceAuto, 4612 /*UseTypeSugar*/ false) 4613 .TransformType(TypeWithAuto); 4614} 4615 4616void Sema::DiagnoseAutoDeductionFailure(VarDecl *VDecl, Expr *Init) { 4617 if (isa<InitListExpr>(Init)) 4618 Diag(VDecl->getLocation(), 4619 VDecl->isInitCapture() 4620 ? diag::err_init_capture_deduction_failure_from_init_list 4621 : diag::err_auto_var_deduction_failure_from_init_list) 4622 << VDecl->getDeclName() << VDecl->getType() << Init->getSourceRange(); 4623 else 4624 Diag(VDecl->getLocation(), 4625 VDecl->isInitCapture() ? diag::err_init_capture_deduction_failure 4626 : diag::err_auto_var_deduction_failure) 4627 << VDecl->getDeclName() << VDecl->getType() << Init->getType() 4628 << Init->getSourceRange(); 4629} 4630 4631bool Sema::DeduceReturnType(FunctionDecl *FD, SourceLocation Loc, 4632 bool Diagnose) { 4633 assert(FD->getReturnType()->isUndeducedType())((FD->getReturnType()->isUndeducedType()) ? static_cast
<void> (0) : __assert_fail ("FD->getReturnType()->isUndeducedType()"
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 4633, __PRETTY_FUNCTION__))
; 4634 4635 // For a lambda's conversion operator, deduce any 'auto' or 'decltype(auto)' 4636 // within the return type from the call operator's type. 4637 if (isLambdaConversionOperator(FD)) { 4638 CXXRecordDecl *Lambda = cast<CXXMethodDecl>(FD)->getParent(); 4639 FunctionDecl *CallOp = Lambda->getLambdaCallOperator(); 4640 4641 // For a generic lambda, instantiate the call operator if needed. 4642 if (auto *Args = FD->getTemplateSpecializationArgs()) { 4643 CallOp = InstantiateFunctionDeclaration( 4644 CallOp->getDescribedFunctionTemplate(), Args, Loc); 4645 if (!CallOp || CallOp->isInvalidDecl()) 4646 return true; 4647 4648 // We might need to deduce the return type by instantiating the definition 4649 // of the operator() function. 4650 if (CallOp->getReturnType()->isUndeducedType()) { 4651 runWithSufficientStackSpace(Loc, [&] { 4652 InstantiateFunctionDefinition(Loc, CallOp); 4653 }); 4654 } 4655 } 4656 4657 if (CallOp->isInvalidDecl()) 4658 return true; 4659 assert(!CallOp->getReturnType()->isUndeducedType() &&((!CallOp->getReturnType()->isUndeducedType() &&
"failed to deduce lambda return type") ? static_cast<void
> (0) : __assert_fail ("!CallOp->getReturnType()->isUndeducedType() && \"failed to deduce lambda return type\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 4660, __PRETTY_FUNCTION__))
4660 "failed to deduce lambda return type")((!CallOp->getReturnType()->isUndeducedType() &&
"failed to deduce lambda return type") ? static_cast<void
> (0) : __assert_fail ("!CallOp->getReturnType()->isUndeducedType() && \"failed to deduce lambda return type\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 4660, __PRETTY_FUNCTION__))
; 4661 4662 // Build the new return type from scratch. 4663 QualType RetType = getLambdaConversionFunctionResultType( 4664 CallOp->getType()->castAs<FunctionProtoType>()); 4665 if (FD->getReturnType()->getAs<PointerType>()) 4666 RetType = Context.getPointerType(RetType); 4667 else { 4668 assert(FD->getReturnType()->getAs<BlockPointerType>())((FD->getReturnType()->getAs<BlockPointerType>())
? static_cast<void> (0) : __assert_fail ("FD->getReturnType()->getAs<BlockPointerType>()"
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 4668, __PRETTY_FUNCTION__))
; 4669 RetType = Context.getBlockPointerType(RetType); 4670 } 4671 Context.adjustDeducedFunctionResultType(FD, RetType); 4672 return false; 4673 } 4674 4675 if (FD->getTemplateInstantiationPattern()) { 4676 runWithSufficientStackSpace(Loc, [&] { 4677 InstantiateFunctionDefinition(Loc, FD); 4678 }); 4679 } 4680 4681 bool StillUndeduced = FD->getReturnType()->isUndeducedType(); 4682 if (StillUndeduced && Diagnose && !FD->isInvalidDecl()) { 4683 Diag(Loc, diag::err_auto_fn_used_before_defined) << FD; 4684 Diag(FD->getLocation(), diag::note_callee_decl) << FD; 4685 } 4686 4687 return StillUndeduced; 4688} 4689 4690/// If this is a non-static member function, 4691static void 4692AddImplicitObjectParameterType(ASTContext &Context, 4693 CXXMethodDecl *Method, 4694 SmallVectorImpl<QualType> &ArgTypes) { 4695 // C++11 [temp.func.order]p3: 4696 // [...] The new parameter is of type "reference to cv A," where cv are 4697 // the cv-qualifiers of the function template (if any) and A is 4698 // the class of which the function template is a member. 4699 // 4700 // The standard doesn't say explicitly, but we pick the appropriate kind of 4701 // reference type based on [over.match.funcs]p4. 4702 QualType ArgTy = Context.getTypeDeclType(Method->getParent()); 4703 ArgTy = Context.getQualifiedType(ArgTy, Method->getMethodQualifiers()); 4704 if (Method->getRefQualifier() == RQ_RValue) 4705 ArgTy = Context.getRValueReferenceType(ArgTy); 4706 else 4707 ArgTy = Context.getLValueReferenceType(ArgTy); 4708 ArgTypes.push_back(ArgTy); 4709} 4710 4711/// Determine whether the function template \p FT1 is at least as 4712/// specialized as \p FT2. 4713static bool isAtLeastAsSpecializedAs(Sema &S, 4714 SourceLocation Loc, 4715 FunctionTemplateDecl *FT1, 4716 FunctionTemplateDecl *FT2, 4717 TemplatePartialOrderingContext TPOC, 4718 unsigned NumCallArguments1) { 4719 FunctionDecl *FD1 = FT1->getTemplatedDecl(); 4720 FunctionDecl *FD2 = FT2->getTemplatedDecl(); 4721 const FunctionProtoType *Proto1 = FD1->getType()->getAs<FunctionProtoType>(); 4722 const FunctionProtoType *Proto2 = FD2->getType()->getAs<FunctionProtoType>(); 4723 4724 assert(Proto1 && Proto2 && "Function templates must have prototypes")((Proto1 && Proto2 && "Function templates must have prototypes"
) ? static_cast<void> (0) : __assert_fail ("Proto1 && Proto2 && \"Function templates must have prototypes\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 4724, __PRETTY_FUNCTION__))
; 4725 TemplateParameterList *TemplateParams = FT2->getTemplateParameters(); 4726 SmallVector<DeducedTemplateArgument, 4> Deduced; 4727 Deduced.resize(TemplateParams->size()); 4728 4729 // C++0x [temp.deduct.partial]p3: 4730 // The types used to determine the ordering depend on the context in which 4731 // the partial ordering is done: 4732 TemplateDeductionInfo Info(Loc); 4733 SmallVector<QualType, 4> Args2; 4734 switch (TPOC) { 4735 case TPOC_Call: { 4736 // - In the context of a function call, the function parameter types are 4737 // used. 4738 CXXMethodDecl *Method1 = dyn_cast<CXXMethodDecl>(FD1); 4739 CXXMethodDecl *Method2 = dyn_cast<CXXMethodDecl>(FD2); 4740 4741 // C++11 [temp.func.order]p3: 4742 // [...] If only one of the function templates is a non-static 4743 // member, that function template is considered to have a new 4744 // first parameter inserted in its function parameter list. The 4745 // new parameter is of type "reference to cv A," where cv are 4746 // the cv-qualifiers of the function template (if any) and A is 4747 // the class of which the function template is a member. 4748 // 4749 // Note that we interpret this to mean "if one of the function 4750 // templates is a non-static member and the other is a non-member"; 4751 // otherwise, the ordering rules for static functions against non-static 4752 // functions don't make any sense. 4753 // 4754 // C++98/03 doesn't have this provision but we've extended DR532 to cover 4755 // it as wording was broken prior to it. 4756 SmallVector<QualType, 4> Args1; 4757 4758 unsigned NumComparedArguments = NumCallArguments1; 4759 4760 if (!Method2 && Method1 && !Method1->isStatic()) { 4761 // Compare 'this' from Method1 against first parameter from Method2. 4762 AddImplicitObjectParameterType(S.Context, Method1, Args1); 4763 ++NumComparedArguments; 4764 } else if (!Method1 && Method2 && !Method2->isStatic()) { 4765 // Compare 'this' from Method2 against first parameter from Method1. 4766 AddImplicitObjectParameterType(S.Context, Method2, Args2); 4767 } 4768 4769 Args1.insert(Args1.end(), Proto1->param_type_begin(), 4770 Proto1->param_type_end()); 4771 Args2.insert(Args2.end(), Proto2->param_type_begin(), 4772 Proto2->param_type_end()); 4773 4774 // C++ [temp.func.order]p5: 4775 // The presence of unused ellipsis and default arguments has no effect on 4776 // the partial ordering of function templates. 4777 if (Args1.size() > NumComparedArguments) 4778 Args1.resize(NumComparedArguments); 4779 if (Args2.size() > NumComparedArguments) 4780 Args2.resize(NumComparedArguments); 4781 if (DeduceTemplateArguments(S, TemplateParams, Args2.data(), Args2.size(), 4782 Args1.data(), Args1.size(), Info, Deduced, 4783 TDF_None, /*PartialOrdering=*/true)) 4784 return false; 4785 4786 break; 4787 } 4788 4789 case TPOC_Conversion: 4790 // - In the context of a call to a conversion operator, the return types 4791 // of the conversion function templates are used. 4792 if (DeduceTemplateArgumentsByTypeMatch( 4793 S, TemplateParams, Proto2->getReturnType(), Proto1->getReturnType(), 4794 Info, Deduced, TDF_None, 4795 /*PartialOrdering=*/true)) 4796 return false; 4797 break; 4798 4799 case TPOC_Other: 4800 // - In other contexts (14.6.6.2) the function template's function type 4801 // is used. 4802 if (DeduceTemplateArgumentsByTypeMatch(S, TemplateParams, 4803 FD2->getType(), FD1->getType(), 4804 Info, Deduced, TDF_None, 4805 /*PartialOrdering=*/true)) 4806 return false; 4807 break; 4808 } 4809 4810 // C++0x [temp.deduct.partial]p11: 4811 // In most cases, all template parameters must have values in order for 4812 // deduction to succeed, but for partial ordering purposes a template 4813 // parameter may remain without a value provided it is not used in the 4814 // types being used for partial ordering. [ Note: a template parameter used 4815 // in a non-deduced context is considered used. -end note] 4816 unsigned ArgIdx = 0, NumArgs = Deduced.size(); 4817 for (; ArgIdx != NumArgs; ++ArgIdx) 4818 if (Deduced[ArgIdx].isNull()) 4819 break; 4820 4821 // FIXME: We fail to implement [temp.deduct.type]p1 along this path. We need 4822 // to substitute the deduced arguments back into the template and check that 4823 // we get the right type. 4824 4825 if (ArgIdx == NumArgs) { 4826 // All template arguments were deduced. FT1 is at least as specialized 4827 // as FT2. 4828 return true; 4829 } 4830 4831 // Figure out which template parameters were used. 4832 llvm::SmallBitVector UsedParameters(TemplateParams->size()); 4833 switch (TPOC) { 4834 case TPOC_Call: 4835 for (unsigned I = 0, N = Args2.size(); I != N; ++I) 4836 ::MarkUsedTemplateParameters(S.Context, Args2[I], false, 4837 TemplateParams->getDepth(), 4838 UsedParameters); 4839 break; 4840 4841 case TPOC_Conversion: 4842 ::MarkUsedTemplateParameters(S.Context, Proto2->getReturnType(), false, 4843 TemplateParams->getDepth(), UsedParameters); 4844 break; 4845 4846 case TPOC_Other: 4847 ::MarkUsedTemplateParameters(S.Context, FD2->getType(), false, 4848 TemplateParams->getDepth(), 4849 UsedParameters); 4850 break; 4851 } 4852 4853 for (; ArgIdx != NumArgs; ++ArgIdx) 4854 // If this argument had no value deduced but was used in one of the types 4855 // used for partial ordering, then deduction fails. 4856 if (Deduced[ArgIdx].isNull() && UsedParameters[ArgIdx]) 4857 return false; 4858 4859 return true; 4860} 4861 4862/// Determine whether this a function template whose parameter-type-list 4863/// ends with a function parameter pack. 4864static bool isVariadicFunctionTemplate(FunctionTemplateDecl *FunTmpl) { 4865 FunctionDecl *Function = FunTmpl->getTemplatedDecl(); 4866 unsigned NumParams = Function->getNumParams(); 4867 if (NumParams == 0) 4868 return false; 4869 4870 ParmVarDecl *Last = Function->getParamDecl(NumParams - 1); 4871 if (!Last->isParameterPack()) 4872 return false; 4873 4874 // Make sure that no previous parameter is a parameter pack. 4875 while (--NumParams > 0) { 4876 if (Function->getParamDecl(NumParams - 1)->isParameterPack()) 4877 return false; 4878 } 4879 4880 return true; 4881} 4882 4883/// Returns the more specialized function template according 4884/// to the rules of function template partial ordering (C++ [temp.func.order]). 4885/// 4886/// \param FT1 the first function template 4887/// 4888/// \param FT2 the second function template 4889/// 4890/// \param TPOC the context in which we are performing partial ordering of 4891/// function templates. 4892/// 4893/// \param NumCallArguments1 The number of arguments in the call to FT1, used 4894/// only when \c TPOC is \c TPOC_Call. 4895/// 4896/// \param NumCallArguments2 The number of arguments in the call to FT2, used 4897/// only when \c TPOC is \c TPOC_Call. 4898/// 4899/// \returns the more specialized function template. If neither 4900/// template is more specialized, returns NULL. 4901FunctionTemplateDecl * 4902Sema::getMoreSpecializedTemplate(FunctionTemplateDecl *FT1, 4903 FunctionTemplateDecl *FT2, 4904 SourceLocation Loc, 4905 TemplatePartialOrderingContext TPOC, 4906 unsigned NumCallArguments1, 4907 unsigned NumCallArguments2) { 4908 bool Better1 = isAtLeastAsSpecializedAs(*this, Loc, FT1, FT2, TPOC, 4909 NumCallArguments1); 4910 bool Better2 = isAtLeastAsSpecializedAs(*this, Loc, FT2, FT1, TPOC, 4911 NumCallArguments2); 4912 4913 if (Better1 != Better2) // We have a clear winner 4914 return Better1 ? FT1 : FT2; 4915 4916 if (!Better1 && !Better2) // Neither is better than the other 4917 return nullptr; 4918 4919 // FIXME: This mimics what GCC implements, but doesn't match up with the 4920 // proposed resolution for core issue 692. This area needs to be sorted out, 4921 // but for now we attempt to maintain compatibility. 4922 bool Variadic1 = isVariadicFunctionTemplate(FT1); 4923 bool Variadic2 = isVariadicFunctionTemplate(FT2); 4924 if (Variadic1 != Variadic2) 4925 return Variadic1? FT2 : FT1; 4926 4927 return nullptr; 4928} 4929 4930/// Determine if the two templates are equivalent. 4931static bool isSameTemplate(TemplateDecl *T1, TemplateDecl *T2) { 4932 if (T1 == T2) 4933 return true; 4934 4935 if (!T1 || !T2) 4936 return false; 4937 4938 return T1->getCanonicalDecl() == T2->getCanonicalDecl(); 4939} 4940 4941/// Retrieve the most specialized of the given function template 4942/// specializations. 4943/// 4944/// \param SpecBegin the start iterator of the function template 4945/// specializations that we will be comparing. 4946/// 4947/// \param SpecEnd the end iterator of the function template 4948/// specializations, paired with \p SpecBegin. 4949/// 4950/// \param Loc the location where the ambiguity or no-specializations 4951/// diagnostic should occur. 4952/// 4953/// \param NoneDiag partial diagnostic used to diagnose cases where there are 4954/// no matching candidates. 4955/// 4956/// \param AmbigDiag partial diagnostic used to diagnose an ambiguity, if one 4957/// occurs. 4958/// 4959/// \param CandidateDiag partial diagnostic used for each function template 4960/// specialization that is a candidate in the ambiguous ordering. One parameter 4961/// in this diagnostic should be unbound, which will correspond to the string 4962/// describing the template arguments for the function template specialization. 4963/// 4964/// \returns the most specialized function template specialization, if 4965/// found. Otherwise, returns SpecEnd. 4966UnresolvedSetIterator Sema::getMostSpecialized( 4967 UnresolvedSetIterator SpecBegin, UnresolvedSetIterator SpecEnd, 4968 TemplateSpecCandidateSet &FailedCandidates, 4969 SourceLocation Loc, const PartialDiagnostic &NoneDiag, 4970 const PartialDiagnostic &AmbigDiag, const PartialDiagnostic &CandidateDiag, 4971 bool Complain, QualType TargetType) { 4972 if (SpecBegin == SpecEnd) { 4973 if (Complain) { 4974 Diag(Loc, NoneDiag); 4975 FailedCandidates.NoteCandidates(*this, Loc); 4976 } 4977 return SpecEnd; 4978 } 4979 4980 if (SpecBegin + 1 == SpecEnd) 4981 return SpecBegin; 4982 4983 // Find the function template that is better than all of the templates it 4984 // has been compared to. 4985 UnresolvedSetIterator Best = SpecBegin; 4986 FunctionTemplateDecl *BestTemplate 4987 = cast<FunctionDecl>(*Best)->getPrimaryTemplate(); 4988 assert(BestTemplate && "Not a function template specialization?")((BestTemplate && "Not a function template specialization?"
) ? static_cast<void> (0) : __assert_fail ("BestTemplate && \"Not a function template specialization?\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 4988, __PRETTY_FUNCTION__))
; 4989 for (UnresolvedSetIterator I = SpecBegin + 1; I != SpecEnd; ++I) { 4990 FunctionTemplateDecl *Challenger 4991 = cast<FunctionDecl>(*I)->getPrimaryTemplate(); 4992 assert(Challenger && "Not a function template specialization?")((Challenger && "Not a function template specialization?"
) ? static_cast<void> (0) : __assert_fail ("Challenger && \"Not a function template specialization?\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 4992, __PRETTY_FUNCTION__))
; 4993 if (isSameTemplate(getMoreSpecializedTemplate(BestTemplate, Challenger, 4994 Loc, TPOC_Other, 0, 0), 4995 Challenger)) { 4996 Best = I; 4997 BestTemplate = Challenger; 4998 } 4999 } 5000 5001 // Make sure that the "best" function template is more specialized than all 5002 // of the others. 5003 bool Ambiguous = false; 5004 for (UnresolvedSetIterator I = SpecBegin; I != SpecEnd; ++I) { 5005 FunctionTemplateDecl *Challenger 5006 = cast<FunctionDecl>(*I)->getPrimaryTemplate(); 5007 if (I != Best && 5008 !isSameTemplate(getMoreSpecializedTemplate(BestTemplate, Challenger, 5009 Loc, TPOC_Other, 0, 0), 5010 BestTemplate)) { 5011 Ambiguous = true; 5012 break; 5013 } 5014 } 5015 5016 if (!Ambiguous) { 5017 // We found an answer. Return it. 5018 return Best; 5019 } 5020 5021 // Diagnose the ambiguity. 5022 if (Complain) { 5023 Diag(Loc, AmbigDiag); 5024 5025 // FIXME: Can we order the candidates in some sane way? 5026 for (UnresolvedSetIterator I = SpecBegin; I != SpecEnd; ++I) { 5027 PartialDiagnostic PD = CandidateDiag; 5028 const auto *FD = cast<FunctionDecl>(*I); 5029 PD << FD << getTemplateArgumentBindingsText( 5030 FD->getPrimaryTemplate()->getTemplateParameters(), 5031 *FD->getTemplateSpecializationArgs()); 5032 if (!TargetType.isNull()) 5033 HandleFunctionTypeMismatch(PD, FD->getType(), TargetType); 5034 Diag((*I)->getLocation(), PD); 5035 } 5036 } 5037 5038 return SpecEnd; 5039} 5040 5041/// Determine whether one partial specialization, P1, is at least as 5042/// specialized than another, P2. 5043/// 5044/// \tparam TemplateLikeDecl The kind of P2, which must be a 5045/// TemplateDecl or {Class,Var}TemplatePartialSpecializationDecl. 5046/// \param T1 The injected-class-name of P1 (faked for a variable template). 5047/// \param T2 The injected-class-name of P2 (faked for a variable template). 5048template<typename TemplateLikeDecl> 5049static bool isAtLeastAsSpecializedAs(Sema &S, QualType T1, QualType T2, 5050 TemplateLikeDecl *P2, 5051 TemplateDeductionInfo &Info) { 5052 // C++ [temp.class.order]p1: 5053 // For two class template partial specializations, the first is at least as 5054 // specialized as the second if, given the following rewrite to two 5055 // function templates, the first function template is at least as 5056 // specialized as the second according to the ordering rules for function 5057 // templates (14.6.6.2): 5058 // - the first function template has the same template parameters as the 5059 // first partial specialization and has a single function parameter 5060 // whose type is a class template specialization with the template 5061 // arguments of the first partial specialization, and 5062 // - the second function template has the same template parameters as the 5063 // second partial specialization and has a single function parameter 5064 // whose type is a class template specialization with the template 5065 // arguments of the second partial specialization. 5066 // 5067 // Rather than synthesize function templates, we merely perform the 5068 // equivalent partial ordering by performing deduction directly on 5069 // the template arguments of the class template partial 5070 // specializations. This computation is slightly simpler than the 5071 // general problem of function template partial ordering, because 5072 // class template partial specializations are more constrained. We 5073 // know that every template parameter is deducible from the class 5074 // template partial specialization's template arguments, for 5075 // example. 5076 SmallVector<DeducedTemplateArgument, 4> Deduced; 5077 5078 // Determine whether P1 is at least as specialized as P2. 5079 Deduced.resize(P2->getTemplateParameters()->size()); 5080 if (DeduceTemplateArgumentsByTypeMatch(S, P2->getTemplateParameters(), 5081 T2, T1, Info, Deduced, TDF_None, 5082 /*PartialOrdering=*/true)) 5083 return false; 5084 5085 SmallVector<TemplateArgument, 4> DeducedArgs(Deduced.begin(), 5086 Deduced.end()); 5087 Sema::InstantiatingTemplate Inst(S, Info.getLocation(), P2, DeducedArgs, 5088 Info); 5089 auto *TST1 = T1->castAs<TemplateSpecializationType>(); 5090 if (FinishTemplateArgumentDeduction( 5091 S, P2, /*IsPartialOrdering=*/true, 5092 TemplateArgumentList(TemplateArgumentList::OnStack, 5093 TST1->template_arguments()), 5094 Deduced, Info)) 5095 return false; 5096 5097 return true; 5098} 5099 5100/// Returns the more specialized class template partial specialization 5101/// according to the rules of partial ordering of class template partial 5102/// specializations (C++ [temp.class.order]). 5103/// 5104/// \param PS1 the first class template partial specialization 5105/// 5106/// \param PS2 the second class template partial specialization 5107/// 5108/// \returns the more specialized class template partial specialization. If 5109/// neither partial specialization is more specialized, returns NULL. 5110ClassTemplatePartialSpecializationDecl * 5111Sema::getMoreSpecializedPartialSpecialization( 5112 ClassTemplatePartialSpecializationDecl *PS1, 5113 ClassTemplatePartialSpecializationDecl *PS2, 5114 SourceLocation Loc) { 5115 QualType PT1 = PS1->getInjectedSpecializationType(); 5116 QualType PT2 = PS2->getInjectedSpecializationType(); 5117 5118 TemplateDeductionInfo Info(Loc); 5119 bool Better1 = isAtLeastAsSpecializedAs(*this, PT1, PT2, PS2, Info); 5120 bool Better2 = isAtLeastAsSpecializedAs(*this, PT2, PT1, PS1, Info); 5121 5122 if (Better1 == Better2) 5123 return nullptr; 5124 5125 return Better1 ? PS1 : PS2; 5126} 5127 5128bool Sema::isMoreSpecializedThanPrimary( 5129 ClassTemplatePartialSpecializationDecl *Spec, TemplateDeductionInfo &Info) { 5130 ClassTemplateDecl *Primary = Spec->getSpecializedTemplate(); 5131 QualType PrimaryT = Primary->getInjectedClassNameSpecialization(); 5132 QualType PartialT = Spec->getInjectedSpecializationType(); 5133 if (!isAtLeastAsSpecializedAs(*this, PartialT, PrimaryT, Primary, Info)) 5134 return false; 5135 if (isAtLeastAsSpecializedAs(*this, PrimaryT, PartialT, Spec, Info)) { 5136 Info.clearSFINAEDiagnostic(); 5137 return false; 5138 } 5139 return true; 5140} 5141 5142VarTemplatePartialSpecializationDecl * 5143Sema::getMoreSpecializedPartialSpecialization( 5144 VarTemplatePartialSpecializationDecl *PS1, 5145 VarTemplatePartialSpecializationDecl *PS2, SourceLocation Loc) { 5146 // Pretend the variable template specializations are class template 5147 // specializations and form a fake injected class name type for comparison. 5148 assert(PS1->getSpecializedTemplate() == PS2->getSpecializedTemplate() &&((PS1->getSpecializedTemplate() == PS2->getSpecializedTemplate
() && "the partial specializations being compared should specialize"
" the same template.") ? static_cast<void> (0) : __assert_fail
("PS1->getSpecializedTemplate() == PS2->getSpecializedTemplate() && \"the partial specializations being compared should specialize\" \" the same template.\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 5150, __PRETTY_FUNCTION__))
5149 "the partial specializations being compared should specialize"((PS1->getSpecializedTemplate() == PS2->getSpecializedTemplate
() && "the partial specializations being compared should specialize"
" the same template.") ? static_cast<void> (0) : __assert_fail
("PS1->getSpecializedTemplate() == PS2->getSpecializedTemplate() && \"the partial specializations being compared should specialize\" \" the same template.\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 5150, __PRETTY_FUNCTION__))
5150 " the same template.")((PS1->getSpecializedTemplate() == PS2->getSpecializedTemplate
() && "the partial specializations being compared should specialize"
" the same template.") ? static_cast<void> (0) : __assert_fail
("PS1->getSpecializedTemplate() == PS2->getSpecializedTemplate() && \"the partial specializations being compared should specialize\" \" the same template.\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 5150, __PRETTY_FUNCTION__))
; 5151 TemplateName Name(PS1->getSpecializedTemplate()); 5152 TemplateName CanonTemplate = Context.getCanonicalTemplateName(Name); 5153 QualType PT1 = Context.getTemplateSpecializationType( 5154 CanonTemplate, PS1->getTemplateArgs().asArray()); 5155 QualType PT2 = Context.getTemplateSpecializationType( 5156 CanonTemplate, PS2->getTemplateArgs().asArray()); 5157 5158 TemplateDeductionInfo Info(Loc); 5159 bool Better1 = isAtLeastAsSpecializedAs(*this, PT1, PT2, PS2, Info); 5160 bool Better2 = isAtLeastAsSpecializedAs(*this, PT2, PT1, PS1, Info); 5161 5162 if (Better1 == Better2) 5163 return nullptr; 5164 5165 return Better1 ? PS1 : PS2; 5166} 5167 5168bool Sema::isMoreSpecializedThanPrimary( 5169 VarTemplatePartialSpecializationDecl *Spec, TemplateDeductionInfo &Info) { 5170 TemplateDecl *Primary = Spec->getSpecializedTemplate(); 5171 // FIXME: Cache the injected template arguments rather than recomputing 5172 // them for each partial specialization. 5173 SmallVector<TemplateArgument, 8> PrimaryArgs; 5174 Context.getInjectedTemplateArgs(Primary->getTemplateParameters(), 5175 PrimaryArgs); 5176 5177 TemplateName CanonTemplate = 5178 Context.getCanonicalTemplateName(TemplateName(Primary)); 5179 QualType PrimaryT = Context.getTemplateSpecializationType( 5180 CanonTemplate, PrimaryArgs); 5181 QualType PartialT = Context.getTemplateSpecializationType( 5182 CanonTemplate, Spec->getTemplateArgs().asArray()); 5183 if (!isAtLeastAsSpecializedAs(*this, PartialT, PrimaryT, Primary, Info)) 5184 return false; 5185 if (isAtLeastAsSpecializedAs(*this, PrimaryT, PartialT, Spec, Info)) { 5186 Info.clearSFINAEDiagnostic(); 5187 return false; 5188 } 5189 return true; 5190} 5191 5192bool Sema::isTemplateTemplateParameterAtLeastAsSpecializedAs( 5193 TemplateParameterList *P, TemplateDecl *AArg, SourceLocation Loc) { 5194 // C++1z [temp.arg.template]p4: (DR 150) 5195 // A template template-parameter P is at least as specialized as a 5196 // template template-argument A if, given the following rewrite to two 5197 // function templates... 5198 5199 // Rather than synthesize function templates, we merely perform the 5200 // equivalent partial ordering by performing deduction directly on 5201 // the template parameter lists of the template template parameters. 5202 // 5203 // Given an invented class template X with the template parameter list of 5204 // A (including default arguments): 5205 TemplateName X = Context.getCanonicalTemplateName(TemplateName(AArg)); 5206 TemplateParameterList *A = AArg->getTemplateParameters(); 5207 5208 // - Each function template has a single function parameter whose type is 5209 // a specialization of X with template arguments corresponding to the 5210 // template parameters from the respective function template 5211 SmallVector<TemplateArgument, 8> AArgs; 5212 Context.getInjectedTemplateArgs(A, AArgs); 5213 5214 // Check P's arguments against A's parameter list. This will fill in default 5215 // template arguments as needed. AArgs are already correct by construction. 5216 // We can't just use CheckTemplateIdType because that will expand alias 5217 // templates. 5218 SmallVector<TemplateArgument, 4> PArgs; 5219 { 5220 SFINAETrap Trap(*this); 5221 5222 Context.getInjectedTemplateArgs(P, PArgs); 5223 TemplateArgumentListInfo PArgList(P->getLAngleLoc(), P->getRAngleLoc()); 5224 for (unsigned I = 0, N = P->size(); I != N; ++I) { 5225 // Unwrap packs that getInjectedTemplateArgs wrapped around pack 5226 // expansions, to form an "as written" argument list. 5227 TemplateArgument Arg = PArgs[I]; 5228 if (Arg.getKind() == TemplateArgument::Pack) { 5229 assert(Arg.pack_size() == 1 && Arg.pack_begin()->isPackExpansion())((Arg.pack_size() == 1 && Arg.pack_begin()->isPackExpansion
()) ? static_cast<void> (0) : __assert_fail ("Arg.pack_size() == 1 && Arg.pack_begin()->isPackExpansion()"
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 5229, __PRETTY_FUNCTION__))
; 5230 Arg = *Arg.pack_begin(); 5231 } 5232 PArgList.addArgument(getTrivialTemplateArgumentLoc( 5233 Arg, QualType(), P->getParam(I)->getLocation())); 5234 } 5235 PArgs.clear(); 5236 5237 // C++1z [temp.arg.template]p3: 5238 // If the rewrite produces an invalid type, then P is not at least as 5239 // specialized as A. 5240 if (CheckTemplateArgumentList(AArg, Loc, PArgList, false, PArgs) || 5241 Trap.hasErrorOccurred()) 5242 return false; 5243 } 5244 5245 QualType AType = Context.getTemplateSpecializationType(X, AArgs); 5246 QualType PType = Context.getTemplateSpecializationType(X, PArgs); 5247 5248 // ... the function template corresponding to P is at least as specialized 5249 // as the function template corresponding to A according to the partial 5250 // ordering rules for function templates. 5251 TemplateDeductionInfo Info(Loc, A->getDepth()); 5252 return isAtLeastAsSpecializedAs(*this, PType, AType, AArg, Info); 5253} 5254 5255/// Mark the template parameters that are used by the given 5256/// expression. 5257static void 5258MarkUsedTemplateParameters(ASTContext &Ctx, 5259 const Expr *E, 5260 bool OnlyDeduced, 5261 unsigned Depth, 5262 llvm::SmallBitVector &Used) { 5263 // We can deduce from a pack expansion. 5264 if (const PackExpansionExpr *Expansion = dyn_cast<PackExpansionExpr>(E)) 5265 E = Expansion->getPattern(); 5266 5267 // Skip through any implicit casts we added while type-checking, and any 5268 // substitutions performed by template alias expansion. 5269 while (true) { 5270 if (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) 5271 E = ICE->getSubExpr(); 5272 else if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(E)) 5273 E = CE->getSubExpr(); 5274 else if (const SubstNonTypeTemplateParmExpr *Subst = 5275 dyn_cast<SubstNonTypeTemplateParmExpr>(E)) 5276 E = Subst->getReplacement(); 5277 else 5278 break; 5279 } 5280 5281 // FIXME: if !OnlyDeduced, we have to walk the whole subexpression to 5282 // find other occurrences of template parameters. 5283 const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E); 5284 if (!DRE) 5285 return; 5286 5287 const NonTypeTemplateParmDecl *NTTP 5288 = dyn_cast<NonTypeTemplateParmDecl>(DRE->getDecl()); 5289 if (!NTTP) 5290 return; 5291 5292 if (NTTP->getDepth() == Depth) 5293 Used[NTTP->getIndex()] = true; 5294 5295 // In C++17 mode, additional arguments may be deduced from the type of a 5296 // non-type argument. 5297 if (Ctx.getLangOpts().CPlusPlus17) 5298 MarkUsedTemplateParameters(Ctx, NTTP->getType(), OnlyDeduced, Depth, Used); 5299} 5300 5301/// Mark the template parameters that are used by the given 5302/// nested name specifier. 5303static void 5304MarkUsedTemplateParameters(ASTContext &Ctx, 5305 NestedNameSpecifier *NNS, 5306 bool OnlyDeduced, 5307 unsigned Depth, 5308 llvm::SmallBitVector &Used) { 5309 if (!NNS) 5310 return; 5311 5312 MarkUsedTemplateParameters(Ctx, NNS->getPrefix(), OnlyDeduced, Depth, 5313 Used); 5314 MarkUsedTemplateParameters(Ctx, QualType(NNS->getAsType(), 0), 5315 OnlyDeduced, Depth, Used); 5316} 5317 5318/// Mark the template parameters that are used by the given 5319/// template name. 5320static void 5321MarkUsedTemplateParameters(ASTContext &Ctx, 5322 TemplateName Name, 5323 bool OnlyDeduced, 5324 unsigned Depth, 5325 llvm::SmallBitVector &Used) { 5326 if (TemplateDecl *Template = Name.getAsTemplateDecl()) { 5327 if (TemplateTemplateParmDecl *TTP 5328 = dyn_cast<TemplateTemplateParmDecl>(Template)) { 5329 if (TTP->getDepth() == Depth) 5330 Used[TTP->getIndex()] = true; 5331 } 5332 return; 5333 } 5334 5335 if (QualifiedTemplateName *QTN = Name.getAsQualifiedTemplateName()) 5336 MarkUsedTemplateParameters(Ctx, QTN->getQualifier(), OnlyDeduced, 5337 Depth, Used); 5338 if (DependentTemplateName *DTN = Name.getAsDependentTemplateName()) 5339 MarkUsedTemplateParameters(Ctx, DTN->getQualifier(), OnlyDeduced, 5340 Depth, Used); 5341} 5342 5343/// Mark the template parameters that are used by the given 5344/// type. 5345static void 5346MarkUsedTemplateParameters(ASTContext &Ctx, QualType T, 5347 bool OnlyDeduced, 5348 unsigned Depth, 5349 llvm::SmallBitVector &Used) { 5350 if (T.isNull()) 5351 return; 5352 5353 // Non-dependent types have nothing deducible 5354 if (!T->isDependentType()) 5355 return; 5356 5357 T = Ctx.getCanonicalType(T); 5358 switch (T->getTypeClass()) { 5359 case Type::Pointer: 5360 MarkUsedTemplateParameters(Ctx, 5361 cast<PointerType>(T)->getPointeeType(), 5362 OnlyDeduced, 5363 Depth, 5364 Used); 5365 break; 5366 5367 case Type::BlockPointer: 5368 MarkUsedTemplateParameters(Ctx, 5369 cast<BlockPointerType>(T)->getPointeeType(), 5370 OnlyDeduced, 5371 Depth, 5372 Used); 5373 break; 5374 5375 case Type::LValueReference: 5376 case Type::RValueReference: 5377 MarkUsedTemplateParameters(Ctx, 5378 cast<ReferenceType>(T)->getPointeeType(), 5379 OnlyDeduced, 5380 Depth, 5381 Used); 5382 break; 5383 5384 case Type::MemberPointer: { 5385 const MemberPointerType *MemPtr = cast<MemberPointerType>(T.getTypePtr()); 5386 MarkUsedTemplateParameters(Ctx, MemPtr->getPointeeType(), OnlyDeduced, 5387 Depth, Used); 5388 MarkUsedTemplateParameters(Ctx, QualType(MemPtr->getClass(), 0), 5389 OnlyDeduced, Depth, Used); 5390 break; 5391 } 5392 5393 case Type::DependentSizedArray: 5394 MarkUsedTemplateParameters(Ctx, 5395 cast<DependentSizedArrayType>(T)->getSizeExpr(), 5396 OnlyDeduced, Depth, Used); 5397 // Fall through to check the element type 5398 LLVM_FALLTHROUGH[[gnu::fallthrough]]; 5399 5400 case Type::ConstantArray: 5401 case Type::IncompleteArray: 5402 MarkUsedTemplateParameters(Ctx, 5403 cast<ArrayType>(T)->getElementType(), 5404 OnlyDeduced, Depth, Used); 5405 break; 5406 5407 case Type::Vector: 5408 case Type::ExtVector: 5409 MarkUsedTemplateParameters(Ctx, 5410 cast<VectorType>(T)->getElementType(), 5411 OnlyDeduced, Depth, Used); 5412 break; 5413 5414 case Type::DependentVector: { 5415 const auto *VecType = cast<DependentVectorType>(T); 5416 MarkUsedTemplateParameters(Ctx, VecType->getElementType(), OnlyDeduced, 5417 Depth, Used); 5418 MarkUsedTemplateParameters(Ctx, VecType->getSizeExpr(), OnlyDeduced, Depth, 5419 Used); 5420 break; 5421 } 5422 case Type::DependentSizedExtVector: { 5423 const DependentSizedExtVectorType *VecType 5424 = cast<DependentSizedExtVectorType>(T); 5425 MarkUsedTemplateParameters(Ctx, VecType->getElementType(), OnlyDeduced, 5426 Depth, Used); 5427 MarkUsedTemplateParameters(Ctx, VecType->getSizeExpr(), OnlyDeduced, 5428 Depth, Used); 5429 break; 5430 } 5431 5432 case Type::DependentAddressSpace: { 5433 const DependentAddressSpaceType *DependentASType = 5434 cast<DependentAddressSpaceType>(T); 5435 MarkUsedTemplateParameters(Ctx, DependentASType->getPointeeType(), 5436 OnlyDeduced, Depth, Used); 5437 MarkUsedTemplateParameters(Ctx, 5438 DependentASType->getAddrSpaceExpr(), 5439 OnlyDeduced, Depth, Used); 5440 break; 5441 } 5442 5443 case Type::FunctionProto: { 5444 const FunctionProtoType *Proto = cast<FunctionProtoType>(T); 5445 MarkUsedTemplateParameters(Ctx, Proto->getReturnType(), OnlyDeduced, Depth, 5446 Used); 5447 for (unsigned I = 0, N = Proto->getNumParams(); I != N; ++I) { 5448 // C++17 [temp.deduct.type]p5: 5449 // The non-deduced contexts are: [...] 5450 // -- A function parameter pack that does not occur at the end of the 5451 // parameter-declaration-list. 5452 if (!OnlyDeduced || I + 1 == N || 5453 !Proto->getParamType(I)->getAs<PackExpansionType>()) { 5454 MarkUsedTemplateParameters(Ctx, Proto->getParamType(I), OnlyDeduced, 5455 Depth, Used); 5456 } else { 5457 // FIXME: C++17 [temp.deduct.call]p1: 5458 // When a function parameter pack appears in a non-deduced context, 5459 // the type of that pack is never deduced. 5460 // 5461 // We should also track a set of "never deduced" parameters, and 5462 // subtract that from the list of deduced parameters after marking. 5463 } 5464 } 5465 if (auto *E = Proto->getNoexceptExpr()) 5466 MarkUsedTemplateParameters(Ctx, E, OnlyDeduced, Depth, Used); 5467 break; 5468 } 5469 5470 case Type::TemplateTypeParm: { 5471 const TemplateTypeParmType *TTP = cast<TemplateTypeParmType>(T); 5472 if (TTP->getDepth() == Depth) 5473 Used[TTP->getIndex()] = true; 5474 break; 5475 } 5476 5477 case Type::SubstTemplateTypeParmPack: { 5478 const SubstTemplateTypeParmPackType *Subst 5479 = cast<SubstTemplateTypeParmPackType>(T); 5480 MarkUsedTemplateParameters(Ctx, 5481 QualType(Subst->getReplacedParameter(), 0), 5482 OnlyDeduced, Depth, Used); 5483 MarkUsedTemplateParameters(Ctx, Subst->getArgumentPack(), 5484 OnlyDeduced, Depth, Used); 5485 break; 5486 } 5487 5488 case Type::InjectedClassName: 5489 T = cast<InjectedClassNameType>(T)->getInjectedSpecializationType(); 5490 LLVM_FALLTHROUGH[[gnu::fallthrough]]; 5491 5492 case Type::TemplateSpecialization: { 5493 const TemplateSpecializationType *Spec 5494 = cast<TemplateSpecializationType>(T); 5495 MarkUsedTemplateParameters(Ctx, Spec->getTemplateName(), OnlyDeduced, 5496 Depth, Used); 5497 5498 // C++0x [temp.deduct.type]p9: 5499 // If the template argument list of P contains a pack expansion that is 5500 // not the last template argument, the entire template argument list is a 5501 // non-deduced context. 5502 if (OnlyDeduced && 5503 hasPackExpansionBeforeEnd(Spec->template_arguments())) 5504 break; 5505 5506 for (unsigned I = 0, N = Spec->getNumArgs(); I != N; ++I) 5507 MarkUsedTemplateParameters(Ctx, Spec->getArg(I), OnlyDeduced, Depth, 5508 Used); 5509 break; 5510 } 5511 5512 case Type::Complex: 5513 if (!OnlyDeduced) 5514 MarkUsedTemplateParameters(Ctx, 5515 cast<ComplexType>(T)->getElementType(), 5516 OnlyDeduced, Depth, Used); 5517 break; 5518 5519 case Type::Atomic: 5520 if (!OnlyDeduced) 5521 MarkUsedTemplateParameters(Ctx, 5522 cast<AtomicType>(T)->getValueType(), 5523 OnlyDeduced, Depth, Used); 5524 break; 5525 5526 case Type::DependentName: 5527 if (!OnlyDeduced) 5528 MarkUsedTemplateParameters(Ctx, 5529 cast<DependentNameType>(T)->getQualifier(), 5530 OnlyDeduced, Depth, Used); 5531 break; 5532 5533 case Type::DependentTemplateSpecialization: { 5534 // C++14 [temp.deduct.type]p5: 5535 // The non-deduced contexts are: 5536 // -- The nested-name-specifier of a type that was specified using a 5537 // qualified-id 5538 // 5539 // C++14 [temp.deduct.type]p6: 5540 // When a type name is specified in a way that includes a non-deduced 5541 // context, all of the types that comprise that type name are also 5542 // non-deduced. 5543 if (OnlyDeduced) 5544 break; 5545 5546 const DependentTemplateSpecializationType *Spec 5547 = cast<DependentTemplateSpecializationType>(T); 5548 5549 MarkUsedTemplateParameters(Ctx, Spec->getQualifier(), 5550 OnlyDeduced, Depth, Used); 5551 5552 for (unsigned I = 0, N = Spec->getNumArgs(); I != N; ++I) 5553 MarkUsedTemplateParameters(Ctx, Spec->getArg(I), OnlyDeduced, Depth, 5554 Used); 5555 break; 5556 } 5557 5558 case Type::TypeOf: 5559 if (!OnlyDeduced) 5560 MarkUsedTemplateParameters(Ctx, 5561 cast<TypeOfType>(T)->getUnderlyingType(), 5562 OnlyDeduced, Depth, Used); 5563 break; 5564 5565 case Type::TypeOfExpr: 5566 if (!OnlyDeduced) 5567 MarkUsedTemplateParameters(Ctx, 5568 cast<TypeOfExprType>(T)->getUnderlyingExpr(), 5569 OnlyDeduced, Depth, Used); 5570 break; 5571 5572 case Type::Decltype: 5573 if (!OnlyDeduced) 5574 MarkUsedTemplateParameters(Ctx, 5575 cast<DecltypeType>(T)->getUnderlyingExpr(), 5576 OnlyDeduced, Depth, Used); 5577 break; 5578 5579 case Type::UnaryTransform: 5580 if (!OnlyDeduced) 5581 MarkUsedTemplateParameters(Ctx, 5582 cast<UnaryTransformType>(T)->getUnderlyingType(), 5583 OnlyDeduced, Depth, Used); 5584 break; 5585 5586 case Type::PackExpansion: 5587 MarkUsedTemplateParameters(Ctx, 5588 cast<PackExpansionType>(T)->getPattern(), 5589 OnlyDeduced, Depth, Used); 5590 break; 5591 5592 case Type::Auto: 5593 case Type::DeducedTemplateSpecialization: 5594 MarkUsedTemplateParameters(Ctx, 5595 cast<DeducedType>(T)->getDeducedType(), 5596 OnlyDeduced, Depth, Used); 5597 break; 5598 5599 // None of these types have any template parameters in them. 5600 case Type::Builtin: 5601 case Type::VariableArray: 5602 case Type::FunctionNoProto: 5603 case Type::Record: 5604 case Type::Enum: 5605 case Type::ObjCInterface: 5606 case Type::ObjCObject: 5607 case Type::ObjCObjectPointer: 5608 case Type::UnresolvedUsing: 5609 case Type::Pipe: 5610#define TYPE(Class, Base) 5611#define ABSTRACT_TYPE(Class, Base) 5612#define DEPENDENT_TYPE(Class, Base) 5613#define NON_CANONICAL_TYPE(Class, Base) case Type::Class: 5614#include "clang/AST/TypeNodes.inc" 5615 break; 5616 } 5617} 5618 5619/// Mark the template parameters that are used by this 5620/// template argument. 5621static void 5622MarkUsedTemplateParameters(ASTContext &Ctx, 5623 const TemplateArgument &TemplateArg, 5624 bool OnlyDeduced, 5625 unsigned Depth, 5626 llvm::SmallBitVector &Used) { 5627 switch (TemplateArg.getKind()) { 5628 case TemplateArgument::Null: 5629 case TemplateArgument::Integral: 5630 case TemplateArgument::Declaration: 5631 break; 5632 5633 case TemplateArgument::NullPtr: 5634 MarkUsedTemplateParameters(Ctx, TemplateArg.getNullPtrType(), OnlyDeduced, 5635 Depth, Used); 5636 break; 5637 5638 case TemplateArgument::Type: 5639 MarkUsedTemplateParameters(Ctx, TemplateArg.getAsType(), OnlyDeduced, 5640 Depth, Used); 5641 break; 5642 5643 case TemplateArgument::Template: 5644 case TemplateArgument::TemplateExpansion: 5645 MarkUsedTemplateParameters(Ctx, 5646 TemplateArg.getAsTemplateOrTemplatePattern(), 5647 OnlyDeduced, Depth, Used); 5648 break; 5649 5650 case TemplateArgument::Expression: 5651 MarkUsedTemplateParameters(Ctx, TemplateArg.getAsExpr(), OnlyDeduced, 5652 Depth, Used); 5653 break; 5654 5655 case TemplateArgument::Pack: 5656 for (const auto &P : TemplateArg.pack_elements()) 5657 MarkUsedTemplateParameters(Ctx, P, OnlyDeduced, Depth, Used); 5658 break; 5659 } 5660} 5661 5662/// Mark which template parameters can be deduced from a given 5663/// template argument list. 5664/// 5665/// \param TemplateArgs the template argument list from which template 5666/// parameters will be deduced. 5667/// 5668/// \param Used a bit vector whose elements will be set to \c true 5669/// to indicate when the corresponding template parameter will be 5670/// deduced. 5671void 5672Sema::MarkUsedTemplateParameters(const TemplateArgumentList &TemplateArgs, 5673 bool OnlyDeduced, unsigned Depth, 5674 llvm::SmallBitVector &Used) { 5675 // C++0x [temp.deduct.type]p9: 5676 // If the template argument list of P contains a pack expansion that is not 5677 // the last template argument, the entire template argument list is a 5678 // non-deduced context. 5679 if (OnlyDeduced && 5680 hasPackExpansionBeforeEnd(TemplateArgs.asArray())) 5681 return; 5682 5683 for (unsigned I = 0, N = TemplateArgs.size(); I != N; ++I) 5684 ::MarkUsedTemplateParameters(Context, TemplateArgs[I], OnlyDeduced, 5685 Depth, Used); 5686} 5687 5688/// Marks all of the template parameters that will be deduced by a 5689/// call to the given function template. 5690void Sema::MarkDeducedTemplateParameters( 5691 ASTContext &Ctx, const FunctionTemplateDecl *FunctionTemplate, 5692 llvm::SmallBitVector &Deduced) { 5693 TemplateParameterList *TemplateParams 5694 = FunctionTemplate->getTemplateParameters(); 5695 Deduced.clear(); 5696 Deduced.resize(TemplateParams->size()); 5697 5698 FunctionDecl *Function = FunctionTemplate->getTemplatedDecl(); 5699 for (unsigned I = 0, N = Function->getNumParams(); I != N; ++I) 5700 ::MarkUsedTemplateParameters(Ctx, Function->getParamDecl(I)->getType(), 5701 true, TemplateParams->getDepth(), Deduced); 5702} 5703 5704bool hasDeducibleTemplateParameters(Sema &S, 5705 FunctionTemplateDecl *FunctionTemplate, 5706 QualType T) { 5707 if (!T->isDependentType()) 5708 return false; 5709 5710 TemplateParameterList *TemplateParams 5711 = FunctionTemplate->getTemplateParameters(); 5712 llvm::SmallBitVector Deduced(TemplateParams->size()); 5713 ::MarkUsedTemplateParameters(S.Context, T, true, TemplateParams->getDepth(), 5714 Deduced); 5715 5716 return Deduced.any(); 5717}

/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/include/clang/AST/Type.h

1//===- Type.h - C Language Family Type Representation -----------*- C++ -*-===//
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/// \file
10/// C Language Family Type Representation
11///
12/// This file defines the clang::Type interface and subclasses, used to
13/// represent types for languages in the C family.
14//
15//===----------------------------------------------------------------------===//
16
17#ifndef LLVM_CLANG_AST_TYPE_H
18#define LLVM_CLANG_AST_TYPE_H
19
20#include "clang/AST/NestedNameSpecifier.h"
21#include "clang/AST/TemplateName.h"
22#include "clang/Basic/AddressSpaces.h"
23#include "clang/Basic/AttrKinds.h"
24#include "clang/Basic/Diagnostic.h"
25#include "clang/Basic/ExceptionSpecificationType.h"
26#include "clang/Basic/LLVM.h"
27#include "clang/Basic/Linkage.h"
28#include "clang/Basic/PartialDiagnostic.h"
29#include "clang/Basic/SourceLocation.h"
30#include "clang/Basic/Specifiers.h"
31#include "clang/Basic/Visibility.h"
32#include "llvm/ADT/APInt.h"
33#include "llvm/ADT/APSInt.h"
34#include "llvm/ADT/ArrayRef.h"
35#include "llvm/ADT/FoldingSet.h"
36#include "llvm/ADT/None.h"
37#include "llvm/ADT/Optional.h"
38#include "llvm/ADT/PointerIntPair.h"
39#include "llvm/ADT/PointerUnion.h"
40#include "llvm/ADT/StringRef.h"
41#include "llvm/ADT/Twine.h"
42#include "llvm/ADT/iterator_range.h"
43#include "llvm/Support/Casting.h"
44#include "llvm/Support/Compiler.h"
45#include "llvm/Support/ErrorHandling.h"
46#include "llvm/Support/PointerLikeTypeTraits.h"
47#include "llvm/Support/type_traits.h"
48#include "llvm/Support/TrailingObjects.h"
49#include <cassert>
50#include <cstddef>
51#include <cstdint>
52#include <cstring>
53#include <string>
54#include <type_traits>
55#include <utility>
56
57namespace clang {
58
59class ExtQuals;
60class QualType;
61class TagDecl;
62class Type;
63
64enum {
65 TypeAlignmentInBits = 4,
66 TypeAlignment = 1 << TypeAlignmentInBits
67};
68
69} // namespace clang
70
71namespace llvm {
72
73 template <typename T>
74 struct PointerLikeTypeTraits;
75 template<>
76 struct PointerLikeTypeTraits< ::clang::Type*> {
77 static inline void *getAsVoidPointer(::clang::Type *P) { return P; }
78
79 static inline ::clang::Type *getFromVoidPointer(void *P) {
80 return static_cast< ::clang::Type*>(P);
81 }
82
83 enum { NumLowBitsAvailable = clang::TypeAlignmentInBits };
84 };
85
86 template<>
87 struct PointerLikeTypeTraits< ::clang::ExtQuals*> {
88 static inline void *getAsVoidPointer(::clang::ExtQuals *P) { return P; }
89
90 static inline ::clang::ExtQuals *getFromVoidPointer(void *P) {
91 return static_cast< ::clang::ExtQuals*>(P);
92 }
93
94 enum { NumLowBitsAvailable = clang::TypeAlignmentInBits };
95 };
96
97} // namespace llvm
98
99namespace clang {
100
101class ASTContext;
102template <typename> class CanQual;
103class CXXRecordDecl;
104class DeclContext;
105class EnumDecl;
106class Expr;
107class ExtQualsTypeCommonBase;
108class FunctionDecl;
109class IdentifierInfo;
110class NamedDecl;
111class ObjCInterfaceDecl;
112class ObjCProtocolDecl;
113class ObjCTypeParamDecl;
114struct PrintingPolicy;
115class RecordDecl;
116class Stmt;
117class TagDecl;
118class TemplateArgument;
119class TemplateArgumentListInfo;
120class TemplateArgumentLoc;
121class TemplateTypeParmDecl;
122class TypedefNameDecl;
123class UnresolvedUsingTypenameDecl;
124
125using CanQualType = CanQual<Type>;
126
127// Provide forward declarations for all of the *Type classes.
128#define TYPE(Class, Base) class Class##Type;
129#include "clang/AST/TypeNodes.inc"
130
131/// The collection of all-type qualifiers we support.
132/// Clang supports five independent qualifiers:
133/// * C99: const, volatile, and restrict
134/// * MS: __unaligned
135/// * Embedded C (TR18037): address spaces
136/// * Objective C: the GC attributes (none, weak, or strong)
137class Qualifiers {
138public:
139 enum TQ { // NOTE: These flags must be kept in sync with DeclSpec::TQ.
140 Const = 0x1,
141 Restrict = 0x2,
142 Volatile = 0x4,
143 CVRMask = Const | Volatile | Restrict
144 };
145
146 enum GC {
147 GCNone = 0,
148 Weak,
149 Strong
150 };
151
152 enum ObjCLifetime {
153 /// There is no lifetime qualification on this type.
154 OCL_None,
155
156 /// This object can be modified without requiring retains or
157 /// releases.
158 OCL_ExplicitNone,
159
160 /// Assigning into this object requires the old value to be
161 /// released and the new value to be retained. The timing of the
162 /// release of the old value is inexact: it may be moved to
163 /// immediately after the last known point where the value is
164 /// live.
165 OCL_Strong,
166
167 /// Reading or writing from this object requires a barrier call.
168 OCL_Weak,
169
170 /// Assigning into this object requires a lifetime extension.
171 OCL_Autoreleasing
172 };
173
174 enum {
175 /// The maximum supported address space number.
176 /// 23 bits should be enough for anyone.
177 MaxAddressSpace = 0x7fffffu,
178
179 /// The width of the "fast" qualifier mask.
180 FastWidth = 3,
181
182 /// The fast qualifier mask.
183 FastMask = (1 << FastWidth) - 1
184 };
185
186 /// Returns the common set of qualifiers while removing them from
187 /// the given sets.
188 static Qualifiers removeCommonQualifiers(Qualifiers &L, Qualifiers &R) {
189 // If both are only CVR-qualified, bit operations are sufficient.
190 if (!(L.Mask & ~CVRMask) && !(R.Mask & ~CVRMask)) {
191 Qualifiers Q;
192 Q.Mask = L.Mask & R.Mask;
193 L.Mask &= ~Q.Mask;