Bug Summary

File:tools/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 -analyzer-config-compatibility-mode=true -mrelocation-model pic -pic-level 2 -mthread-model posix -mframe-pointer=none -relaxed-aliasing -fmath-errno -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~svn374877/build-llvm/tools/clang/lib/Sema -I /build/llvm-toolchain-snapshot-10~svn374877/tools/clang/lib/Sema -I /build/llvm-toolchain-snapshot-10~svn374877/tools/clang/include -I /build/llvm-toolchain-snapshot-10~svn374877/build-llvm/tools/clang/include -I /build/llvm-toolchain-snapshot-10~svn374877/build-llvm/include -I /build/llvm-toolchain-snapshot-10~svn374877/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~svn374877/build-llvm/tools/clang/lib/Sema -fdebug-prefix-map=/build/llvm-toolchain-snapshot-10~svn374877=. -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-2019-10-15-233810-7101-1 -x c++ /build/llvm-toolchain-snapshot-10~svn374877/tools/clang/lib/Sema/SemaTemplateDeduction.cpp

/build/llvm-toolchain-snapshot-10~svn374877/tools/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~svn374877/tools/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~svn374877/tools/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~svn374877/tools/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~svn374877/tools/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~svn374877/tools/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~svn374877/tools/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~svn374877/tools/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~svn374877/tools/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~svn374877/tools/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~svn374877/tools/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~svn374877/tools/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~svn374877/tools/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~svn374877/tools/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~svn374877/tools/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~svn374877/tools/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~svn374877/tools/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~svn374877/tools/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~svn374877/tools/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~svn374877/tools/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~svn374877/tools/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~svn374877/tools/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~svn374877/tools/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~svn374877/tools/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~svn374877/tools/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~svn374877/tools/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~svn374877/tools/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~svn374877/tools/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~svn374877/tools/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~svn374877/tools/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~svn374877/tools/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~svn374877/tools/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~svn374877/tools/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~svn374877/tools/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~svn374877/tools/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~svn374877/tools/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~svn374877/tools/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~svn374877/tools/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~svn374877/tools/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 FunctionProtoType *Proto 3830 = Function->getType()->getAs<FunctionProtoType>(); 3831 if (Proto->isTemplateVariadic()) 3832 /* Do nothing */; 3833 else if (!Proto->isVariadic()) 3834 return TDK_TooManyArguments; 3835 } 3836 3837 // The types of the parameters from which we will perform template argument 3838 // deduction. 3839 LocalInstantiationScope InstScope(*this); 3840 TemplateParameterList *TemplateParams 3841 = FunctionTemplate->getTemplateParameters(); 3842 SmallVector<DeducedTemplateArgument, 4> Deduced; 3843 SmallVector<QualType, 8> ParamTypes; 3844 unsigned NumExplicitlySpecified = 0; 3845 if (ExplicitTemplateArgs) {
5
Assuming 'ExplicitTemplateArgs' is null
6
Taking false branch
3846 TemplateDeductionResult Result = 3847 SubstituteExplicitTemplateArguments(FunctionTemplate, 3848 *ExplicitTemplateArgs, 3849 Deduced, 3850 ParamTypes, 3851 nullptr, 3852 Info); 3853 if (Result) 3854 return Result; 3855 3856 NumExplicitlySpecified = Deduced.size(); 3857 } else { 3858 // Just fill in the parameter types from the function declaration. 3859 for (unsigned I = 0; I != NumParams; ++I)
7
Assuming 'I' is equal to 'NumParams'
8
Loop condition is false. Execution continues on line 3863
3860 ParamTypes.push_back(Function->getParamDecl(I)->getType()); 3861 } 3862 3863 SmallVector<OriginalCallArg, 8> OriginalCallArgs; 3864 3865 // Deduce an argument of type ParamType from an expression with index ArgIdx. 3866 auto DeduceCallArgument = [&](QualType ParamType, unsigned ArgIdx) { 3867 // C++ [demp.deduct.call]p1: (DR1391) 3868 // Template argument deduction is done by comparing each function template 3869 // parameter that contains template-parameters that participate in 3870 // template argument deduction ... 3871 if (!hasDeducibleTemplateParameters(*this, FunctionTemplate, ParamType))
15
Taking false branch
3872 return Sema::TDK_Success; 3873 3874 // ... with the type of the corresponding argument 3875 return DeduceTemplateArgumentsFromCallArgument(
16
Calling 'DeduceTemplateArgumentsFromCallArgument'
3876 *this, TemplateParams, FirstInnerIndex, ParamType, Args[ArgIdx], Info, Deduced, 3877 OriginalCallArgs, /*Decomposed*/false, ArgIdx, /*TDF*/ 0); 3878 }; 3879 3880 // Deduce template arguments from the function parameters. 3881 Deduced.resize(TemplateParams->size()); 3882 SmallVector<QualType, 8> ParamTypesForArgChecking; 3883 for (unsigned ParamIdx = 0, NumParamTypes = ParamTypes.size(), ArgIdx = 0;
10
Loop condition is true. Entering loop body
3884 ParamIdx != NumParamTypes; ++ParamIdx) {
9
Assuming 'ParamIdx' is not equal to 'NumParamTypes'
3885 QualType ParamType = ParamTypes[ParamIdx]; 3886 3887 const PackExpansionType *ParamExpansion = 3888 dyn_cast<PackExpansionType>(ParamType); 3889 if (!ParamExpansion
10.1
'ParamExpansion' is null
10.1
'ParamExpansion' is null
10.1
'ParamExpansion' is null
) {
11
Taking true branch
3890 // Simple case: matching a function parameter to a function argument. 3891 if (ArgIdx >= Args.size())
12
Assuming the condition is false
13
Taking false branch
3892 break; 3893 3894 ParamTypesForArgChecking.push_back(ParamType); 3895 if (auto Result = DeduceCallArgument(ParamType, ArgIdx++))
14
Calling 'operator()'
3896 return Result; 3897 3898 continue; 3899 } 3900 3901 QualType ParamPattern = ParamExpansion->getPattern(); 3902 PackDeductionScope PackScope(*this, TemplateParams, Deduced, Info, 3903 ParamPattern); 3904 3905 // C++0x [temp.deduct.call]p1: 3906 // For a function parameter pack that occurs at the end of the 3907 // parameter-declaration-list, the type A of each remaining argument of 3908 // the call is compared with the type P of the declarator-id of the 3909 // function parameter pack. Each comparison deduces template arguments 3910 // for subsequent positions in the template parameter packs expanded by 3911 // the function parameter pack. When a function parameter pack appears 3912 // in a non-deduced context [not at the end of the list], the type of 3913 // that parameter pack is never deduced. 3914 // 3915 // FIXME: The above rule allows the size of the parameter pack to change 3916 // after we skip it (in the non-deduced case). That makes no sense, so 3917 // we instead notionally deduce the pack against N arguments, where N is 3918 // the length of the explicitly-specified pack if it's expanded by the 3919 // parameter pack and 0 otherwise, and we treat each deduction as a 3920 // non-deduced context. 3921 if (ParamIdx + 1 == NumParamTypes || PackScope.hasFixedArity()) { 3922 for (; ArgIdx < Args.size() && PackScope.hasNextElement(); 3923 PackScope.nextPackElement(), ++ArgIdx) { 3924 ParamTypesForArgChecking.push_back(ParamPattern); 3925 if (auto Result = DeduceCallArgument(ParamPattern, ArgIdx)) 3926 return Result; 3927 } 3928 } else { 3929 // If the parameter type contains an explicitly-specified pack that we 3930 // could not expand, skip the number of parameters notionally created 3931 // by the expansion. 3932 Optional<unsigned> NumExpansions = ParamExpansion->getNumExpansions(); 3933 if (NumExpansions && !PackScope.isPartiallyExpanded()) { 3934 for (unsigned I = 0; I != *NumExpansions && ArgIdx < Args.size(); 3935 ++I, ++ArgIdx) { 3936 ParamTypesForArgChecking.push_back(ParamPattern); 3937 // FIXME: Should we add OriginalCallArgs for these? What if the 3938 // corresponding argument is a list? 3939 PackScope.nextPackElement(); 3940 } 3941 } 3942 } 3943 3944 // Build argument packs for each of the parameter packs expanded by this 3945 // pack expansion. 3946 if (auto Result = PackScope.finish()) 3947 return Result; 3948 } 3949 3950 // Capture the context in which the function call is made. This is the context 3951 // that is needed when the accessibility of template arguments is checked. 3952 DeclContext *CallingCtx = CurContext; 3953 3954 return FinishTemplateArgumentDeduction( 3955 FunctionTemplate, Deduced, NumExplicitlySpecified, Specialization, Info, 3956 &OriginalCallArgs, PartialOverloading, [&, CallingCtx]() { 3957 ContextRAII SavedContext(*this, CallingCtx); 3958 return CheckNonDependent(ParamTypesForArgChecking); 3959 }); 3960} 3961 3962QualType Sema::adjustCCAndNoReturn(QualType ArgFunctionType, 3963 QualType FunctionType, 3964 bool AdjustExceptionSpec) { 3965 if (ArgFunctionType.isNull()) 3966 return ArgFunctionType; 3967 3968 const FunctionProtoType *FunctionTypeP = 3969 FunctionType->castAs<FunctionProtoType>(); 3970 const FunctionProtoType *ArgFunctionTypeP = 3971 ArgFunctionType->getAs<FunctionProtoType>(); 3972 3973 FunctionProtoType::ExtProtoInfo EPI = ArgFunctionTypeP->getExtProtoInfo(); 3974 bool Rebuild = false; 3975 3976 CallingConv CC = FunctionTypeP->getCallConv(); 3977 if (EPI.ExtInfo.getCC() != CC) { 3978 EPI.ExtInfo = EPI.ExtInfo.withCallingConv(CC); 3979 Rebuild = true; 3980 } 3981 3982 bool NoReturn = FunctionTypeP->getNoReturnAttr(); 3983 if (EPI.ExtInfo.getNoReturn() != NoReturn) { 3984 EPI.ExtInfo = EPI.ExtInfo.withNoReturn(NoReturn); 3985 Rebuild = true; 3986 } 3987 3988 if (AdjustExceptionSpec && (FunctionTypeP->hasExceptionSpec() || 3989 ArgFunctionTypeP->hasExceptionSpec())) { 3990 EPI.ExceptionSpec = FunctionTypeP->getExtProtoInfo().ExceptionSpec; 3991 Rebuild = true; 3992 } 3993 3994 if (!Rebuild) 3995 return ArgFunctionType; 3996 3997 return Context.getFunctionType(ArgFunctionTypeP->getReturnType(), 3998 ArgFunctionTypeP->getParamTypes(), EPI); 3999} 4000 4001/// Deduce template arguments when taking the address of a function 4002/// template (C++ [temp.deduct.funcaddr]) or matching a specialization to 4003/// a template. 4004/// 4005/// \param FunctionTemplate the function template for which we are performing 4006/// template argument deduction. 4007/// 4008/// \param ExplicitTemplateArgs the explicitly-specified template 4009/// arguments. 4010/// 4011/// \param ArgFunctionType the function type that will be used as the 4012/// "argument" type (A) when performing template argument deduction from the 4013/// function template's function type. This type may be NULL, if there is no 4014/// argument type to compare against, in C++0x [temp.arg.explicit]p3. 4015/// 4016/// \param Specialization if template argument deduction was successful, 4017/// this will be set to the function template specialization produced by 4018/// template argument deduction. 4019/// 4020/// \param Info the argument will be updated to provide additional information 4021/// about template argument deduction. 4022/// 4023/// \param IsAddressOfFunction If \c true, we are deducing as part of taking 4024/// the address of a function template per [temp.deduct.funcaddr] and 4025/// [over.over]. If \c false, we are looking up a function template 4026/// specialization based on its signature, per [temp.deduct.decl]. 4027/// 4028/// \returns the result of template argument deduction. 4029Sema::TemplateDeductionResult Sema::DeduceTemplateArguments( 4030 FunctionTemplateDecl *FunctionTemplate, 4031 TemplateArgumentListInfo *ExplicitTemplateArgs, QualType ArgFunctionType, 4032 FunctionDecl *&Specialization, TemplateDeductionInfo &Info, 4033 bool IsAddressOfFunction) { 4034 if (FunctionTemplate->isInvalidDecl()) 4035 return TDK_Invalid; 4036 4037 FunctionDecl *Function = FunctionTemplate->getTemplatedDecl(); 4038 TemplateParameterList *TemplateParams 4039 = FunctionTemplate->getTemplateParameters(); 4040 QualType FunctionType = Function->getType(); 4041 4042 // Substitute any explicit template arguments. 4043 LocalInstantiationScope InstScope(*this); 4044 SmallVector<DeducedTemplateArgument, 4> Deduced; 4045 unsigned NumExplicitlySpecified = 0; 4046 SmallVector<QualType, 4> ParamTypes; 4047 if (ExplicitTemplateArgs) { 4048 if (TemplateDeductionResult Result 4049 = SubstituteExplicitTemplateArguments(FunctionTemplate, 4050 *ExplicitTemplateArgs, 4051 Deduced, ParamTypes, 4052 &FunctionType, Info)) 4053 return Result; 4054 4055 NumExplicitlySpecified = Deduced.size(); 4056 } 4057 4058 // When taking the address of a function, we require convertibility of 4059 // the resulting function type. Otherwise, we allow arbitrary mismatches 4060 // of calling convention and noreturn. 4061 if (!IsAddressOfFunction) 4062 ArgFunctionType = adjustCCAndNoReturn(ArgFunctionType, FunctionType, 4063 /*AdjustExceptionSpec*/false); 4064 4065 // Unevaluated SFINAE context. 4066 EnterExpressionEvaluationContext Unevaluated( 4067 *this, Sema::ExpressionEvaluationContext::Unevaluated); 4068 SFINAETrap Trap(*this); 4069 4070 Deduced.resize(TemplateParams->size()); 4071 4072 // If the function has a deduced return type, substitute it for a dependent 4073 // type so that we treat it as a non-deduced context in what follows. If we 4074 // are looking up by signature, the signature type should also have a deduced 4075 // return type, which we instead expect to exactly match. 4076 bool HasDeducedReturnType = false; 4077 if (getLangOpts().CPlusPlus14 && IsAddressOfFunction && 4078 Function->getReturnType()->getContainedAutoType()) { 4079 FunctionType = SubstAutoType(FunctionType, Context.DependentTy); 4080 HasDeducedReturnType = true; 4081 } 4082 4083 if (!ArgFunctionType.isNull()) { 4084 unsigned TDF = 4085 TDF_TopLevelParameterTypeList | TDF_AllowCompatibleFunctionType; 4086 // Deduce template arguments from the function type. 4087 if (TemplateDeductionResult Result 4088 = DeduceTemplateArgumentsByTypeMatch(*this, TemplateParams, 4089 FunctionType, ArgFunctionType, 4090 Info, Deduced, TDF)) 4091 return Result; 4092 } 4093 4094 if (TemplateDeductionResult Result 4095 = FinishTemplateArgumentDeduction(FunctionTemplate, Deduced, 4096 NumExplicitlySpecified, 4097 Specialization, Info)) 4098 return Result; 4099 4100 // If the function has a deduced return type, deduce it now, so we can check 4101 // that the deduced function type matches the requested type. 4102 if (HasDeducedReturnType && 4103 Specialization->getReturnType()->isUndeducedType() && 4104 DeduceReturnType(Specialization, Info.getLocation(), false)) 4105 return TDK_MiscellaneousDeductionFailure; 4106 4107 // If the function has a dependent exception specification, resolve it now, 4108 // so we can check that the exception specification matches. 4109 auto *SpecializationFPT = 4110 Specialization->getType()->castAs<FunctionProtoType>(); 4111 if (getLangOpts().CPlusPlus17 && 4112 isUnresolvedExceptionSpec(SpecializationFPT->getExceptionSpecType()) && 4113 !ResolveExceptionSpec(Info.getLocation(), SpecializationFPT)) 4114 return TDK_MiscellaneousDeductionFailure; 4115 4116 // Adjust the exception specification of the argument to match the 4117 // substituted and resolved type we just formed. (Calling convention and 4118 // noreturn can't be dependent, so we don't actually need this for them 4119 // right now.) 4120 QualType SpecializationType = Specialization->getType(); 4121 if (!IsAddressOfFunction) 4122 ArgFunctionType = adjustCCAndNoReturn(ArgFunctionType, SpecializationType, 4123 /*AdjustExceptionSpec*/true); 4124 4125 // If the requested function type does not match the actual type of the 4126 // specialization with respect to arguments of compatible pointer to function 4127 // types, template argument deduction fails. 4128 if (!ArgFunctionType.isNull()) { 4129 if (IsAddressOfFunction && 4130 !isSameOrCompatibleFunctionType( 4131 Context.getCanonicalType(SpecializationType), 4132 Context.getCanonicalType(ArgFunctionType))) 4133 return TDK_MiscellaneousDeductionFailure; 4134 4135 if (!IsAddressOfFunction && 4136 !Context.hasSameType(SpecializationType, ArgFunctionType)) 4137 return TDK_MiscellaneousDeductionFailure; 4138 } 4139 4140 return TDK_Success; 4141} 4142 4143/// Deduce template arguments for a templated conversion 4144/// function (C++ [temp.deduct.conv]) and, if successful, produce a 4145/// conversion function template specialization. 4146Sema::TemplateDeductionResult 4147Sema::DeduceTemplateArguments(FunctionTemplateDecl *ConversionTemplate, 4148 QualType ToType, 4149 CXXConversionDecl *&Specialization, 4150 TemplateDeductionInfo &Info) { 4151 if (ConversionTemplate->isInvalidDecl()) 4152 return TDK_Invalid; 4153 4154 CXXConversionDecl *ConversionGeneric 4155 = cast<CXXConversionDecl>(ConversionTemplate->getTemplatedDecl()); 4156 4157 QualType FromType = ConversionGeneric->getConversionType(); 4158 4159 // Canonicalize the types for deduction. 4160 QualType P = Context.getCanonicalType(FromType); 4161 QualType A = Context.getCanonicalType(ToType); 4162 4163 // C++0x [temp.deduct.conv]p2: 4164 // If P is a reference type, the type referred to by P is used for 4165 // type deduction. 4166 if (const ReferenceType *PRef = P->getAs<ReferenceType>()) 4167 P = PRef->getPointeeType(); 4168 4169 // C++0x [temp.deduct.conv]p4: 4170 // [...] If A is a reference type, the type referred to by A is used 4171 // for type deduction. 4172 if (const ReferenceType *ARef = A->getAs<ReferenceType>()) { 4173 A = ARef->getPointeeType(); 4174 // We work around a defect in the standard here: cv-qualifiers are also 4175 // removed from P and A in this case, unless P was a reference type. This 4176 // seems to mostly match what other compilers are doing. 4177 if (!FromType->getAs<ReferenceType>()) { 4178 A = A.getUnqualifiedType(); 4179 P = P.getUnqualifiedType(); 4180 } 4181 4182 // C++ [temp.deduct.conv]p3: 4183 // 4184 // If A is not a reference type: 4185 } else { 4186 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~svn374877/tools/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 4186, __PRETTY_FUNCTION__))
; 4187 4188 // - If P is an array type, the pointer type produced by the 4189 // array-to-pointer standard conversion (4.2) is used in place 4190 // of P for type deduction; otherwise, 4191 if (P->isArrayType()) 4192 P = Context.getArrayDecayedType(P); 4193 // - If P is a function type, the pointer type produced by the 4194 // function-to-pointer standard conversion (4.3) is used in 4195 // place of P for type deduction; otherwise, 4196 else if (P->isFunctionType()) 4197 P = Context.getPointerType(P); 4198 // - If P is a cv-qualified type, the top level cv-qualifiers of 4199 // P's type are ignored for type deduction. 4200 else 4201 P = P.getUnqualifiedType(); 4202 4203 // C++0x [temp.deduct.conv]p4: 4204 // If A is a cv-qualified type, the top level cv-qualifiers of A's 4205 // type are ignored for type deduction. If A is a reference type, the type 4206 // referred to by A is used for type deduction. 4207 A = A.getUnqualifiedType(); 4208 } 4209 4210 // Unevaluated SFINAE context. 4211 EnterExpressionEvaluationContext Unevaluated( 4212 *this, Sema::ExpressionEvaluationContext::Unevaluated); 4213 SFINAETrap Trap(*this); 4214 4215 // C++ [temp.deduct.conv]p1: 4216 // Template argument deduction is done by comparing the return 4217 // type of the template conversion function (call it P) with the 4218 // type that is required as the result of the conversion (call it 4219 // A) as described in 14.8.2.4. 4220 TemplateParameterList *TemplateParams 4221 = ConversionTemplate->getTemplateParameters(); 4222 SmallVector<DeducedTemplateArgument, 4> Deduced; 4223 Deduced.resize(TemplateParams->size()); 4224 4225 // C++0x [temp.deduct.conv]p4: 4226 // In general, the deduction process attempts to find template 4227 // argument values that will make the deduced A identical to 4228 // A. However, there are two cases that allow a difference: 4229 unsigned TDF = 0; 4230 // - If the original A is a reference type, A can be more 4231 // cv-qualified than the deduced A (i.e., the type referred to 4232 // by the reference) 4233 if (ToType->isReferenceType()) 4234 TDF |= TDF_ArgWithReferenceType; 4235 // - The deduced A can be another pointer or pointer to member 4236 // type that can be converted to A via a qualification 4237 // conversion. 4238 // 4239 // (C++0x [temp.deduct.conv]p6 clarifies that this only happens when 4240 // both P and A are pointers or member pointers. In this case, we 4241 // just ignore cv-qualifiers completely). 4242 if ((P->isPointerType() && A->isPointerType()) || 4243 (P->isMemberPointerType() && A->isMemberPointerType())) 4244 TDF |= TDF_IgnoreQualifiers; 4245 if (TemplateDeductionResult Result 4246 = DeduceTemplateArgumentsByTypeMatch(*this, TemplateParams, 4247 P, A, Info, Deduced, TDF)) 4248 return Result; 4249 4250 // Create an Instantiation Scope for finalizing the operator. 4251 LocalInstantiationScope InstScope(*this); 4252 // Finish template argument deduction. 4253 FunctionDecl *ConversionSpecialized = nullptr; 4254 TemplateDeductionResult Result 4255 = FinishTemplateArgumentDeduction(ConversionTemplate, Deduced, 0, 4256 ConversionSpecialized, Info); 4257 Specialization = cast_or_null<CXXConversionDecl>(ConversionSpecialized); 4258 return Result; 4259} 4260 4261/// Deduce template arguments for a function template when there is 4262/// nothing to deduce against (C++0x [temp.arg.explicit]p3). 4263/// 4264/// \param FunctionTemplate the function template for which we are performing 4265/// template argument deduction. 4266/// 4267/// \param ExplicitTemplateArgs the explicitly-specified template 4268/// arguments. 4269/// 4270/// \param Specialization if template argument deduction was successful, 4271/// this will be set to the function template specialization produced by 4272/// template argument deduction. 4273/// 4274/// \param Info the argument will be updated to provide additional information 4275/// about template argument deduction. 4276/// 4277/// \param IsAddressOfFunction If \c true, we are deducing as part of taking 4278/// the address of a function template in a context where we do not have a 4279/// target type, per [over.over]. If \c false, we are looking up a function 4280/// template specialization based on its signature, which only happens when 4281/// deducing a function parameter type from an argument that is a template-id 4282/// naming a function template specialization. 4283/// 4284/// \returns the result of template argument deduction. 4285Sema::TemplateDeductionResult Sema::DeduceTemplateArguments( 4286 FunctionTemplateDecl *FunctionTemplate, 4287 TemplateArgumentListInfo *ExplicitTemplateArgs, 4288 FunctionDecl *&Specialization, TemplateDeductionInfo &Info, 4289 bool IsAddressOfFunction) { 4290 return DeduceTemplateArguments(FunctionTemplate, ExplicitTemplateArgs, 4291 QualType(), Specialization, Info, 4292 IsAddressOfFunction); 4293} 4294 4295namespace { 4296 struct DependentAuto { bool IsPack; }; 4297 4298 /// Substitute the 'auto' specifier or deduced template specialization type 4299 /// specifier within a type for a given replacement type. 4300 class SubstituteDeducedTypeTransform : 4301 public TreeTransform<SubstituteDeducedTypeTransform> { 4302 QualType Replacement; 4303 bool ReplacementIsPack; 4304 bool UseTypeSugar; 4305 4306 public: 4307 SubstituteDeducedTypeTransform(Sema &SemaRef, DependentAuto DA) 4308 : TreeTransform<SubstituteDeducedTypeTransform>(SemaRef), Replacement(), 4309 ReplacementIsPack(DA.IsPack), UseTypeSugar(true) {} 4310 4311 SubstituteDeducedTypeTransform(Sema &SemaRef, QualType Replacement, 4312 bool UseTypeSugar = true) 4313 : TreeTransform<SubstituteDeducedTypeTransform>(SemaRef), 4314 Replacement(Replacement), ReplacementIsPack(false), 4315 UseTypeSugar(UseTypeSugar) {} 4316 4317 QualType TransformDesugared(TypeLocBuilder &TLB, DeducedTypeLoc TL) { 4318 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~svn374877/tools/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 4319, __PRETTY_FUNCTION__))
4319 "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~svn374877/tools/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 4319, __PRETTY_FUNCTION__))
; 4320 QualType Result = Replacement; 4321 TemplateTypeParmTypeLoc NewTL = TLB.push<TemplateTypeParmTypeLoc>(Result); 4322 NewTL.setNameLoc(TL.getNameLoc()); 4323 return Result; 4324 } 4325 4326 QualType TransformAutoType(TypeLocBuilder &TLB, AutoTypeLoc TL) { 4327 // If we're building the type pattern to deduce against, don't wrap the 4328 // substituted type in an AutoType. Certain template deduction rules 4329 // apply only when a template type parameter appears directly (and not if 4330 // the parameter is found through desugaring). For instance: 4331 // auto &&lref = lvalue; 4332 // must transform into "rvalue reference to T" not "rvalue reference to 4333 // auto type deduced as T" in order for [temp.deduct.call]p3 to apply. 4334 // 4335 // FIXME: Is this still necessary? 4336 if (!UseTypeSugar) 4337 return TransformDesugared(TLB, TL); 4338 4339 QualType Result = SemaRef.Context.getAutoType( 4340 Replacement, TL.getTypePtr()->getKeyword(), Replacement.isNull(), 4341 ReplacementIsPack); 4342 auto NewTL = TLB.push<AutoTypeLoc>(Result); 4343 NewTL.setNameLoc(TL.getNameLoc()); 4344 return Result; 4345 } 4346 4347 QualType TransformDeducedTemplateSpecializationType( 4348 TypeLocBuilder &TLB, DeducedTemplateSpecializationTypeLoc TL) { 4349 if (!UseTypeSugar) 4350 return TransformDesugared(TLB, TL); 4351 4352 QualType Result = SemaRef.Context.getDeducedTemplateSpecializationType( 4353 TL.getTypePtr()->getTemplateName(), 4354 Replacement, Replacement.isNull()); 4355 auto NewTL = TLB.push<DeducedTemplateSpecializationTypeLoc>(Result); 4356 NewTL.setNameLoc(TL.getNameLoc()); 4357 return Result; 4358 } 4359 4360 ExprResult TransformLambdaExpr(LambdaExpr *E) { 4361 // Lambdas never need to be transformed. 4362 return E; 4363 } 4364 4365 QualType Apply(TypeLoc TL) { 4366 // Create some scratch storage for the transformed type locations. 4367 // FIXME: We're just going to throw this information away. Don't build it. 4368 TypeLocBuilder TLB; 4369 TLB.reserve(TL.getFullDataSize()); 4370 return TransformType(TLB, TL); 4371 } 4372 }; 4373 4374} // namespace 4375 4376Sema::DeduceAutoResult 4377Sema::DeduceAutoType(TypeSourceInfo *Type, Expr *&Init, QualType &Result, 4378 Optional<unsigned> DependentDeductionDepth) { 4379 return DeduceAutoType(Type->getTypeLoc(), Init, Result, 4380 DependentDeductionDepth); 4381} 4382 4383/// Attempt to produce an informative diagostic explaining why auto deduction 4384/// failed. 4385/// \return \c true if diagnosed, \c false if not. 4386static bool diagnoseAutoDeductionFailure(Sema &S, 4387 Sema::TemplateDeductionResult TDK, 4388 TemplateDeductionInfo &Info, 4389 ArrayRef<SourceRange> Ranges) { 4390 switch (TDK) { 4391 case Sema::TDK_Inconsistent: { 4392 // Inconsistent deduction means we were deducing from an initializer list. 4393 auto D = S.Diag(Info.getLocation(), diag::err_auto_inconsistent_deduction); 4394 D << Info.FirstArg << Info.SecondArg; 4395 for (auto R : Ranges) 4396 D << R; 4397 return true; 4398 } 4399 4400 // FIXME: Are there other cases for which a custom diagnostic is more useful 4401 // than the basic "types don't match" diagnostic? 4402 4403 default: 4404 return false; 4405 } 4406} 4407 4408/// Deduce the type for an auto type-specifier (C++11 [dcl.spec.auto]p6) 4409/// 4410/// Note that this is done even if the initializer is dependent. (This is 4411/// necessary to support partial ordering of templates using 'auto'.) 4412/// A dependent type will be produced when deducing from a dependent type. 4413/// 4414/// \param Type the type pattern using the auto type-specifier. 4415/// \param Init the initializer for the variable whose type is to be deduced. 4416/// \param Result if type deduction was successful, this will be set to the 4417/// deduced type. 4418/// \param DependentDeductionDepth Set if we should permit deduction in 4419/// dependent cases. This is necessary for template partial ordering with 4420/// 'auto' template parameters. The value specified is the template 4421/// parameter depth at which we should perform 'auto' deduction. 4422Sema::DeduceAutoResult 4423Sema::DeduceAutoType(TypeLoc Type, Expr *&Init, QualType &Result, 4424 Optional<unsigned> DependentDeductionDepth) { 4425 if (Init->getType()->isNonOverloadPlaceholderType()) { 4426 ExprResult NonPlaceholder = CheckPlaceholderExpr(Init); 4427 if (NonPlaceholder.isInvalid()) 4428 return DAR_FailedAlreadyDiagnosed; 4429 Init = NonPlaceholder.get(); 4430 } 4431 4432 DependentAuto DependentResult = { 4433 /*.IsPack = */ (bool)Type.getAs<PackExpansionTypeLoc>()}; 4434 4435 if (!DependentDeductionDepth && 4436 (Type.getType()->isDependentType() || Init->isTypeDependent())) { 4437 Result = SubstituteDeducedTypeTransform(*this, DependentResult).Apply(Type); 4438 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~svn374877/tools/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 4438, __PRETTY_FUNCTION__))
; 4439 return DAR_Succeeded; 4440 } 4441 4442 // Find the depth of template parameter to synthesize. 4443 unsigned Depth = DependentDeductionDepth.getValueOr(0); 4444 4445 // If this is a 'decltype(auto)' specifier, do the decltype dance. 4446 // Since 'decltype(auto)' can only occur at the top of the type, we 4447 // don't need to go digging for it. 4448 if (const AutoType *AT = Type.getType()->getAs<AutoType>()) { 4449 if (AT->isDecltypeAuto()) { 4450 if (isa<InitListExpr>(Init)) { 4451 Diag(Init->getBeginLoc(), diag::err_decltype_auto_initializer_list); 4452 return DAR_FailedAlreadyDiagnosed; 4453 } 4454 4455 ExprResult ER = CheckPlaceholderExpr(Init); 4456 if (ER.isInvalid()) 4457 return DAR_FailedAlreadyDiagnosed; 4458 Init = ER.get(); 4459 QualType Deduced = BuildDecltypeType(Init, Init->getBeginLoc(), false); 4460 if (Deduced.isNull()) 4461 return DAR_FailedAlreadyDiagnosed; 4462 // FIXME: Support a non-canonical deduced type for 'auto'. 4463 Deduced = Context.getCanonicalType(Deduced); 4464 Result = SubstituteDeducedTypeTransform(*this, Deduced).Apply(Type); 4465 if (Result.isNull()) 4466 return DAR_FailedAlreadyDiagnosed; 4467 return DAR_Succeeded; 4468 } else if (!getLangOpts().CPlusPlus) { 4469 if (isa<InitListExpr>(Init)) { 4470 Diag(Init->getBeginLoc(), diag::err_auto_init_list_from_c); 4471 return DAR_FailedAlreadyDiagnosed; 4472 } 4473 } 4474 } 4475 4476 SourceLocation Loc = Init->getExprLoc(); 4477 4478 LocalInstantiationScope InstScope(*this); 4479 4480 // Build template<class TemplParam> void Func(FuncParam); 4481 TemplateTypeParmDecl *TemplParam = TemplateTypeParmDecl::Create( 4482 Context, nullptr, SourceLocation(), Loc, Depth, 0, nullptr, false, false); 4483 QualType TemplArg = QualType(TemplParam->getTypeForDecl(), 0); 4484 NamedDecl *TemplParamPtr = TemplParam; 4485 FixedSizeTemplateParameterListStorage<1, false> TemplateParamsSt( 4486 Loc, Loc, TemplParamPtr, Loc, nullptr); 4487 4488 QualType FuncParam = 4489 SubstituteDeducedTypeTransform(*this, TemplArg, /*UseTypeSugar*/false) 4490 .Apply(Type); 4491 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~svn374877/tools/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 4492, __PRETTY_FUNCTION__))
4492 "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~svn374877/tools/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 4492, __PRETTY_FUNCTION__))
; 4493 4494 // Deduce type of TemplParam in Func(Init) 4495 SmallVector<DeducedTemplateArgument, 1> Deduced; 4496 Deduced.resize(1); 4497 4498 TemplateDeductionInfo Info(Loc, Depth); 4499 4500 // If deduction failed, don't diagnose if the initializer is dependent; it 4501 // might acquire a matching type in the instantiation. 4502 auto DeductionFailed = [&](TemplateDeductionResult TDK, 4503 ArrayRef<SourceRange> Ranges) -> DeduceAutoResult { 4504 if (Init->isTypeDependent()) { 4505 Result = 4506 SubstituteDeducedTypeTransform(*this, DependentResult).Apply(Type); 4507 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~svn374877/tools/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 4507, __PRETTY_FUNCTION__))
; 4508 return DAR_Succeeded; 4509 } 4510 if (diagnoseAutoDeductionFailure(*this, TDK, Info, Ranges)) 4511 return DAR_FailedAlreadyDiagnosed; 4512 return DAR_Failed; 4513 }; 4514 4515 SmallVector<OriginalCallArg, 4> OriginalCallArgs; 4516 4517 InitListExpr *InitList = dyn_cast<InitListExpr>(Init); 4518 if (InitList) { 4519 // Notionally, we substitute std::initializer_list<T> for 'auto' and deduce 4520 // against that. Such deduction only succeeds if removing cv-qualifiers and 4521 // references results in std::initializer_list<T>. 4522 if (!Type.getType().getNonReferenceType()->getAs<AutoType>()) 4523 return DAR_Failed; 4524 4525 // Resolving a core issue: a braced-init-list containing any designators is 4526 // a non-deduced context. 4527 for (Expr *E : InitList->inits()) 4528 if (isa<DesignatedInitExpr>(E)) 4529 return DAR_Failed; 4530 4531 SourceRange DeducedFromInitRange; 4532 for (unsigned i = 0, e = InitList->getNumInits(); i < e; ++i) { 4533 Expr *Init = InitList->getInit(i); 4534 4535 if (auto TDK = DeduceTemplateArgumentsFromCallArgument( 4536 *this, TemplateParamsSt.get(), 0, TemplArg, Init, 4537 Info, Deduced, OriginalCallArgs, /*Decomposed*/ true, 4538 /*ArgIdx*/ 0, /*TDF*/ 0)) 4539 return DeductionFailed(TDK, {DeducedFromInitRange, 4540 Init->getSourceRange()}); 4541 4542 if (DeducedFromInitRange.isInvalid() && 4543 Deduced[0].getKind() != TemplateArgument::Null) 4544 DeducedFromInitRange = Init->getSourceRange(); 4545 } 4546 } else { 4547 if (!getLangOpts().CPlusPlus && Init->refersToBitField()) { 4548 Diag(Loc, diag::err_auto_bitfield); 4549 return DAR_FailedAlreadyDiagnosed; 4550 } 4551 4552 if (auto TDK = DeduceTemplateArgumentsFromCallArgument( 4553 *this, TemplateParamsSt.get(), 0, FuncParam, Init, Info, Deduced, 4554 OriginalCallArgs, /*Decomposed*/ false, /*ArgIdx*/ 0, /*TDF*/ 0)) 4555 return DeductionFailed(TDK, {}); 4556 } 4557 4558 // Could be null if somehow 'auto' appears in a non-deduced context. 4559 if (Deduced[0].getKind() != TemplateArgument::Type) 4560 return DeductionFailed(TDK_Incomplete, {}); 4561 4562 QualType DeducedType = Deduced[0].getAsType(); 4563 4564 if (InitList) { 4565 DeducedType = BuildStdInitializerList(DeducedType, Loc); 4566 if (DeducedType.isNull()) 4567 return DAR_FailedAlreadyDiagnosed; 4568 } 4569 4570 Result = SubstituteDeducedTypeTransform(*this, DeducedType).Apply(Type); 4571 if (Result.isNull()) 4572 return DAR_FailedAlreadyDiagnosed; 4573 4574 // Check that the deduced argument type is compatible with the original 4575 // argument type per C++ [temp.deduct.call]p4. 4576 QualType DeducedA = InitList ? Deduced[0].getAsType() : Result; 4577 for (const OriginalCallArg &OriginalArg : OriginalCallArgs) { 4578 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~svn374877/tools/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 4579, __PRETTY_FUNCTION__))
4579 "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~svn374877/tools/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 4579, __PRETTY_FUNCTION__))
; 4580 if (auto TDK = 4581 CheckOriginalCallArgDeduction(*this, Info, OriginalArg, DeducedA)) { 4582 Result = QualType(); 4583 return DeductionFailed(TDK, {}); 4584 } 4585 } 4586 4587 return DAR_Succeeded; 4588} 4589 4590QualType Sema::SubstAutoType(QualType TypeWithAuto, 4591 QualType TypeToReplaceAuto) { 4592 if (TypeToReplaceAuto->isDependentType()) 4593 return SubstituteDeducedTypeTransform( 4594 *this, DependentAuto{ 4595 TypeToReplaceAuto->containsUnexpandedParameterPack()}) 4596 .TransformType(TypeWithAuto); 4597 return SubstituteDeducedTypeTransform(*this, TypeToReplaceAuto) 4598 .TransformType(TypeWithAuto); 4599} 4600 4601TypeSourceInfo *Sema::SubstAutoTypeSourceInfo(TypeSourceInfo *TypeWithAuto, 4602 QualType TypeToReplaceAuto) { 4603 if (TypeToReplaceAuto->isDependentType()) 4604 return SubstituteDeducedTypeTransform( 4605 *this, 4606 DependentAuto{ 4607 TypeToReplaceAuto->containsUnexpandedParameterPack()}) 4608 .TransformType(TypeWithAuto); 4609 return SubstituteDeducedTypeTransform(*this, TypeToReplaceAuto) 4610 .TransformType(TypeWithAuto); 4611} 4612 4613QualType Sema::ReplaceAutoType(QualType TypeWithAuto, 4614 QualType TypeToReplaceAuto) { 4615 return SubstituteDeducedTypeTransform(*this, TypeToReplaceAuto, 4616 /*UseTypeSugar*/ false) 4617 .TransformType(TypeWithAuto); 4618} 4619 4620void Sema::DiagnoseAutoDeductionFailure(VarDecl *VDecl, Expr *Init) { 4621 if (isa<InitListExpr>(Init)) 4622 Diag(VDecl->getLocation(), 4623 VDecl->isInitCapture() 4624 ? diag::err_init_capture_deduction_failure_from_init_list 4625 : diag::err_auto_var_deduction_failure_from_init_list) 4626 << VDecl->getDeclName() << VDecl->getType() << Init->getSourceRange(); 4627 else 4628 Diag(VDecl->getLocation(), 4629 VDecl->isInitCapture() ? diag::err_init_capture_deduction_failure 4630 : diag::err_auto_var_deduction_failure) 4631 << VDecl->getDeclName() << VDecl->getType() << Init->getType() 4632 << Init->getSourceRange(); 4633} 4634 4635bool Sema::DeduceReturnType(FunctionDecl *FD, SourceLocation Loc, 4636 bool Diagnose) { 4637 assert(FD->getReturnType()->isUndeducedType())((FD->getReturnType()->isUndeducedType()) ? static_cast
<void> (0) : __assert_fail ("FD->getReturnType()->isUndeducedType()"
, "/build/llvm-toolchain-snapshot-10~svn374877/tools/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 4637, __PRETTY_FUNCTION__))
; 4638 4639 // For a lambda's conversion operator, deduce any 'auto' or 'decltype(auto)' 4640 // within the return type from the call operator's type. 4641 if (isLambdaConversionOperator(FD)) { 4642 CXXRecordDecl *Lambda = cast<CXXMethodDecl>(FD)->getParent(); 4643 FunctionDecl *CallOp = Lambda->getLambdaCallOperator(); 4644 4645 // For a generic lambda, instantiate the call operator if needed. 4646 if (auto *Args = FD->getTemplateSpecializationArgs()) { 4647 CallOp = InstantiateFunctionDeclaration( 4648 CallOp->getDescribedFunctionTemplate(), Args, Loc); 4649 if (!CallOp || CallOp->isInvalidDecl()) 4650 return true; 4651 4652 // We might need to deduce the return type by instantiating the definition 4653 // of the operator() function. 4654 if (CallOp->getReturnType()->isUndeducedType()) { 4655 runWithSufficientStackSpace(Loc, [&] { 4656 InstantiateFunctionDefinition(Loc, CallOp); 4657 }); 4658 } 4659 } 4660 4661 if (CallOp->isInvalidDecl()) 4662 return true; 4663 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~svn374877/tools/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 4664, __PRETTY_FUNCTION__))
4664 "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~svn374877/tools/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 4664, __PRETTY_FUNCTION__))
; 4665 4666 // Build the new return type from scratch. 4667 QualType RetType = getLambdaConversionFunctionResultType( 4668 CallOp->getType()->castAs<FunctionProtoType>()); 4669 if (FD->getReturnType()->getAs<PointerType>()) 4670 RetType = Context.getPointerType(RetType); 4671 else { 4672 assert(FD->getReturnType()->getAs<BlockPointerType>())((FD->getReturnType()->getAs<BlockPointerType>())
? static_cast<void> (0) : __assert_fail ("FD->getReturnType()->getAs<BlockPointerType>()"
, "/build/llvm-toolchain-snapshot-10~svn374877/tools/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 4672, __PRETTY_FUNCTION__))
; 4673 RetType = Context.getBlockPointerType(RetType); 4674 } 4675 Context.adjustDeducedFunctionResultType(FD, RetType); 4676 return false; 4677 } 4678 4679 if (FD->getTemplateInstantiationPattern()) { 4680 runWithSufficientStackSpace(Loc, [&] { 4681 InstantiateFunctionDefinition(Loc, FD); 4682 }); 4683 } 4684 4685 bool StillUndeduced = FD->getReturnType()->isUndeducedType(); 4686 if (StillUndeduced && Diagnose && !FD->isInvalidDecl()) { 4687 Diag(Loc, diag::err_auto_fn_used_before_defined) << FD; 4688 Diag(FD->getLocation(), diag::note_callee_decl) << FD; 4689 } 4690 4691 return StillUndeduced; 4692} 4693 4694/// If this is a non-static member function, 4695static void 4696AddImplicitObjectParameterType(ASTContext &Context, 4697 CXXMethodDecl *Method, 4698 SmallVectorImpl<QualType> &ArgTypes) { 4699 // C++11 [temp.func.order]p3: 4700 // [...] The new parameter is of type "reference to cv A," where cv are 4701 // the cv-qualifiers of the function template (if any) and A is 4702 // the class of which the function template is a member. 4703 // 4704 // The standard doesn't say explicitly, but we pick the appropriate kind of 4705 // reference type based on [over.match.funcs]p4. 4706 QualType ArgTy = Context.getTypeDeclType(Method->getParent()); 4707 ArgTy = Context.getQualifiedType(ArgTy, Method->getMethodQualifiers()); 4708 if (Method->getRefQualifier() == RQ_RValue) 4709 ArgTy = Context.getRValueReferenceType(ArgTy); 4710 else 4711 ArgTy = Context.getLValueReferenceType(ArgTy); 4712 ArgTypes.push_back(ArgTy); 4713} 4714 4715/// Determine whether the function template \p FT1 is at least as 4716/// specialized as \p FT2. 4717static bool isAtLeastAsSpecializedAs(Sema &S, 4718 SourceLocation Loc, 4719 FunctionTemplateDecl *FT1, 4720 FunctionTemplateDecl *FT2, 4721 TemplatePartialOrderingContext TPOC, 4722 unsigned NumCallArguments1) { 4723 FunctionDecl *FD1 = FT1->getTemplatedDecl(); 4724 FunctionDecl *FD2 = FT2->getTemplatedDecl(); 4725 const FunctionProtoType *Proto1 = FD1->getType()->getAs<FunctionProtoType>(); 4726 const FunctionProtoType *Proto2 = FD2->getType()->getAs<FunctionProtoType>(); 4727 4728 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~svn374877/tools/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 4728, __PRETTY_FUNCTION__))
; 4729 TemplateParameterList *TemplateParams = FT2->getTemplateParameters(); 4730 SmallVector<DeducedTemplateArgument, 4> Deduced; 4731 Deduced.resize(TemplateParams->size()); 4732 4733 // C++0x [temp.deduct.partial]p3: 4734 // The types used to determine the ordering depend on the context in which 4735 // the partial ordering is done: 4736 TemplateDeductionInfo Info(Loc); 4737 SmallVector<QualType, 4> Args2; 4738 switch (TPOC) { 4739 case TPOC_Call: { 4740 // - In the context of a function call, the function parameter types are 4741 // used. 4742 CXXMethodDecl *Method1 = dyn_cast<CXXMethodDecl>(FD1); 4743 CXXMethodDecl *Method2 = dyn_cast<CXXMethodDecl>(FD2); 4744 4745 // C++11 [temp.func.order]p3: 4746 // [...] If only one of the function templates is a non-static 4747 // member, that function template is considered to have a new 4748 // first parameter inserted in its function parameter list. The 4749 // new parameter is of type "reference to cv A," where cv are 4750 // the cv-qualifiers of the function template (if any) and A is 4751 // the class of which the function template is a member. 4752 // 4753 // Note that we interpret this to mean "if one of the function 4754 // templates is a non-static member and the other is a non-member"; 4755 // otherwise, the ordering rules for static functions against non-static 4756 // functions don't make any sense. 4757 // 4758 // C++98/03 doesn't have this provision but we've extended DR532 to cover 4759 // it as wording was broken prior to it. 4760 SmallVector<QualType, 4> Args1; 4761 4762 unsigned NumComparedArguments = NumCallArguments1; 4763 4764 if (!Method2 && Method1 && !Method1->isStatic()) { 4765 // Compare 'this' from Method1 against first parameter from Method2. 4766 AddImplicitObjectParameterType(S.Context, Method1, Args1); 4767 ++NumComparedArguments; 4768 } else if (!Method1 && Method2 && !Method2->isStatic()) { 4769 // Compare 'this' from Method2 against first parameter from Method1. 4770 AddImplicitObjectParameterType(S.Context, Method2, Args2); 4771 } 4772 4773 Args1.insert(Args1.end(), Proto1->param_type_begin(), 4774 Proto1->param_type_end()); 4775 Args2.insert(Args2.end(), Proto2->param_type_begin(), 4776 Proto2->param_type_end()); 4777 4778 // C++ [temp.func.order]p5: 4779 // The presence of unused ellipsis and default arguments has no effect on 4780 // the partial ordering of function templates. 4781 if (Args1.size() > NumComparedArguments) 4782 Args1.resize(NumComparedArguments); 4783 if (Args2.size() > NumComparedArguments) 4784 Args2.resize(NumComparedArguments); 4785 if (DeduceTemplateArguments(S, TemplateParams, Args2.data(), Args2.size(), 4786 Args1.data(), Args1.size(), Info, Deduced, 4787 TDF_None, /*PartialOrdering=*/true)) 4788 return false; 4789 4790 break; 4791 } 4792 4793 case TPOC_Conversion: 4794 // - In the context of a call to a conversion operator, the return types 4795 // of the conversion function templates are used. 4796 if (DeduceTemplateArgumentsByTypeMatch( 4797 S, TemplateParams, Proto2->getReturnType(), Proto1->getReturnType(), 4798 Info, Deduced, TDF_None, 4799 /*PartialOrdering=*/true)) 4800 return false; 4801 break; 4802 4803 case TPOC_Other: 4804 // - In other contexts (14.6.6.2) the function template's function type 4805 // is used. 4806 if (DeduceTemplateArgumentsByTypeMatch(S, TemplateParams, 4807 FD2->getType(), FD1->getType(), 4808 Info, Deduced, TDF_None, 4809 /*PartialOrdering=*/true)) 4810 return false; 4811 break; 4812 } 4813 4814 // C++0x [temp.deduct.partial]p11: 4815 // In most cases, all template parameters must have values in order for 4816 // deduction to succeed, but for partial ordering purposes a template 4817 // parameter may remain without a value provided it is not used in the 4818 // types being used for partial ordering. [ Note: a template parameter used 4819 // in a non-deduced context is considered used. -end note] 4820 unsigned ArgIdx = 0, NumArgs = Deduced.size(); 4821 for (; ArgIdx != NumArgs; ++ArgIdx) 4822 if (Deduced[ArgIdx].isNull()) 4823 break; 4824 4825 // FIXME: We fail to implement [temp.deduct.type]p1 along this path. We need 4826 // to substitute the deduced arguments back into the template and check that 4827 // we get the right type. 4828 4829 if (ArgIdx == NumArgs) { 4830 // All template arguments were deduced. FT1 is at least as specialized 4831 // as FT2. 4832 return true; 4833 } 4834 4835 // Figure out which template parameters were used. 4836 llvm::SmallBitVector UsedParameters(TemplateParams->size()); 4837 switch (TPOC) { 4838 case TPOC_Call: 4839 for (unsigned I = 0, N = Args2.size(); I != N; ++I) 4840 ::MarkUsedTemplateParameters(S.Context, Args2[I], false, 4841 TemplateParams->getDepth(), 4842 UsedParameters); 4843 break; 4844 4845 case TPOC_Conversion: 4846 ::MarkUsedTemplateParameters(S.Context, Proto2->getReturnType(), false, 4847 TemplateParams->getDepth(), UsedParameters); 4848 break; 4849 4850 case TPOC_Other: 4851 ::MarkUsedTemplateParameters(S.Context, FD2->getType(), false, 4852 TemplateParams->getDepth(), 4853 UsedParameters); 4854 break; 4855 } 4856 4857 for (; ArgIdx != NumArgs; ++ArgIdx) 4858 // If this argument had no value deduced but was used in one of the types 4859 // used for partial ordering, then deduction fails. 4860 if (Deduced[ArgIdx].isNull() && UsedParameters[ArgIdx]) 4861 return false; 4862 4863 return true; 4864} 4865 4866/// Determine whether this a function template whose parameter-type-list 4867/// ends with a function parameter pack. 4868static bool isVariadicFunctionTemplate(FunctionTemplateDecl *FunTmpl) { 4869 FunctionDecl *Function = FunTmpl->getTemplatedDecl(); 4870 unsigned NumParams = Function->getNumParams(); 4871 if (NumParams == 0) 4872 return false; 4873 4874 ParmVarDecl *Last = Function->getParamDecl(NumParams - 1); 4875 if (!Last->isParameterPack()) 4876 return false; 4877 4878 // Make sure that no previous parameter is a parameter pack. 4879 while (--NumParams > 0) { 4880 if (Function->getParamDecl(NumParams - 1)->isParameterPack()) 4881 return false; 4882 } 4883 4884 return true; 4885} 4886 4887/// Returns the more specialized function template according 4888/// to the rules of function template partial ordering (C++ [temp.func.order]). 4889/// 4890/// \param FT1 the first function template 4891/// 4892/// \param FT2 the second function template 4893/// 4894/// \param TPOC the context in which we are performing partial ordering of 4895/// function templates. 4896/// 4897/// \param NumCallArguments1 The number of arguments in the call to FT1, used 4898/// only when \c TPOC is \c TPOC_Call. 4899/// 4900/// \param NumCallArguments2 The number of arguments in the call to FT2, used 4901/// only when \c TPOC is \c TPOC_Call. 4902/// 4903/// \returns the more specialized function template. If neither 4904/// template is more specialized, returns NULL. 4905FunctionTemplateDecl * 4906Sema::getMoreSpecializedTemplate(FunctionTemplateDecl *FT1, 4907 FunctionTemplateDecl *FT2, 4908 SourceLocation Loc, 4909 TemplatePartialOrderingContext TPOC, 4910 unsigned NumCallArguments1, 4911 unsigned NumCallArguments2) { 4912 bool Better1 = isAtLeastAsSpecializedAs(*this, Loc, FT1, FT2, TPOC, 4913 NumCallArguments1); 4914 bool Better2 = isAtLeastAsSpecializedAs(*this, Loc, FT2, FT1, TPOC, 4915 NumCallArguments2); 4916 4917 if (Better1 != Better2) // We have a clear winner 4918 return Better1 ? FT1 : FT2; 4919 4920 if (!Better1 && !Better2) // Neither is better than the other 4921 return nullptr; 4922 4923 // FIXME: This mimics what GCC implements, but doesn't match up with the 4924 // proposed resolution for core issue 692. This area needs to be sorted out, 4925 // but for now we attempt to maintain compatibility. 4926 bool Variadic1 = isVariadicFunctionTemplate(FT1); 4927 bool Variadic2 = isVariadicFunctionTemplate(FT2); 4928 if (Variadic1 != Variadic2) 4929 return Variadic1? FT2 : FT1; 4930 4931 return nullptr; 4932} 4933 4934/// Determine if the two templates are equivalent. 4935static bool isSameTemplate(TemplateDecl *T1, TemplateDecl *T2) { 4936 if (T1 == T2) 4937 return true; 4938 4939 if (!T1 || !T2) 4940 return false; 4941 4942 return T1->getCanonicalDecl() == T2->getCanonicalDecl(); 4943} 4944 4945/// Retrieve the most specialized of the given function template 4946/// specializations. 4947/// 4948/// \param SpecBegin the start iterator of the function template 4949/// specializations that we will be comparing. 4950/// 4951/// \param SpecEnd the end iterator of the function template 4952/// specializations, paired with \p SpecBegin. 4953/// 4954/// \param Loc the location where the ambiguity or no-specializations 4955/// diagnostic should occur. 4956/// 4957/// \param NoneDiag partial diagnostic used to diagnose cases where there are 4958/// no matching candidates. 4959/// 4960/// \param AmbigDiag partial diagnostic used to diagnose an ambiguity, if one 4961/// occurs. 4962/// 4963/// \param CandidateDiag partial diagnostic used for each function template 4964/// specialization that is a candidate in the ambiguous ordering. One parameter 4965/// in this diagnostic should be unbound, which will correspond to the string 4966/// describing the template arguments for the function template specialization. 4967/// 4968/// \returns the most specialized function template specialization, if 4969/// found. Otherwise, returns SpecEnd. 4970UnresolvedSetIterator Sema::getMostSpecialized( 4971 UnresolvedSetIterator SpecBegin, UnresolvedSetIterator SpecEnd, 4972 TemplateSpecCandidateSet &FailedCandidates, 4973 SourceLocation Loc, const PartialDiagnostic &NoneDiag, 4974 const PartialDiagnostic &AmbigDiag, const PartialDiagnostic &CandidateDiag, 4975 bool Complain, QualType TargetType) { 4976 if (SpecBegin == SpecEnd) { 4977 if (Complain) { 4978 Diag(Loc, NoneDiag); 4979 FailedCandidates.NoteCandidates(*this, Loc); 4980 } 4981 return SpecEnd; 4982 } 4983 4984 if (SpecBegin + 1 == SpecEnd) 4985 return SpecBegin; 4986 4987 // Find the function template that is better than all of the templates it 4988 // has been compared to. 4989 UnresolvedSetIterator Best = SpecBegin; 4990 FunctionTemplateDecl *BestTemplate 4991 = cast<FunctionDecl>(*Best)->getPrimaryTemplate(); 4992 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~svn374877/tools/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 4992, __PRETTY_FUNCTION__))
; 4993 for (UnresolvedSetIterator I = SpecBegin + 1; I != SpecEnd; ++I) { 4994 FunctionTemplateDecl *Challenger 4995 = cast<FunctionDecl>(*I)->getPrimaryTemplate(); 4996 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~svn374877/tools/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 4996, __PRETTY_FUNCTION__))
; 4997 if (isSameTemplate(getMoreSpecializedTemplate(BestTemplate, Challenger, 4998 Loc, TPOC_Other, 0, 0), 4999 Challenger)) { 5000 Best = I; 5001 BestTemplate = Challenger; 5002 } 5003 } 5004 5005 // Make sure that the "best" function template is more specialized than all 5006 // of the others. 5007 bool Ambiguous = false; 5008 for (UnresolvedSetIterator I = SpecBegin; I != SpecEnd; ++I) { 5009 FunctionTemplateDecl *Challenger 5010 = cast<FunctionDecl>(*I)->getPrimaryTemplate(); 5011 if (I != Best && 5012 !isSameTemplate(getMoreSpecializedTemplate(BestTemplate, Challenger, 5013 Loc, TPOC_Other, 0, 0), 5014 BestTemplate)) { 5015 Ambiguous = true; 5016 break; 5017 } 5018 } 5019 5020 if (!Ambiguous) { 5021 // We found an answer. Return it. 5022 return Best; 5023 } 5024 5025 // Diagnose the ambiguity. 5026 if (Complain) { 5027 Diag(Loc, AmbigDiag); 5028 5029 // FIXME: Can we order the candidates in some sane way? 5030 for (UnresolvedSetIterator I = SpecBegin; I != SpecEnd; ++I) { 5031 PartialDiagnostic PD = CandidateDiag; 5032 const auto *FD = cast<FunctionDecl>(*I); 5033 PD << FD << getTemplateArgumentBindingsText( 5034 FD->getPrimaryTemplate()->getTemplateParameters(), 5035 *FD->getTemplateSpecializationArgs()); 5036 if (!TargetType.isNull()) 5037 HandleFunctionTypeMismatch(PD, FD->getType(), TargetType); 5038 Diag((*I)->getLocation(), PD); 5039 } 5040 } 5041 5042 return SpecEnd; 5043} 5044 5045/// Determine whether one partial specialization, P1, is at least as 5046/// specialized than another, P2. 5047/// 5048/// \tparam TemplateLikeDecl The kind of P2, which must be a 5049/// TemplateDecl or {Class,Var}TemplatePartialSpecializationDecl. 5050/// \param T1 The injected-class-name of P1 (faked for a variable template). 5051/// \param T2 The injected-class-name of P2 (faked for a variable template). 5052template<typename TemplateLikeDecl> 5053static bool isAtLeastAsSpecializedAs(Sema &S, QualType T1, QualType T2, 5054 TemplateLikeDecl *P2, 5055 TemplateDeductionInfo &Info) { 5056 // C++ [temp.class.order]p1: 5057 // For two class template partial specializations, the first is at least as 5058 // specialized as the second if, given the following rewrite to two 5059 // function templates, the first function template is at least as 5060 // specialized as the second according to the ordering rules for function 5061 // templates (14.6.6.2): 5062 // - the first function template has the same template parameters as the 5063 // first partial specialization and has a single function parameter 5064 // whose type is a class template specialization with the template 5065 // arguments of the first partial specialization, and 5066 // - the second function template has the same template parameters as the 5067 // second partial specialization and has a single function parameter 5068 // whose type is a class template specialization with the template 5069 // arguments of the second partial specialization. 5070 // 5071 // Rather than synthesize function templates, we merely perform the 5072 // equivalent partial ordering by performing deduction directly on 5073 // the template arguments of the class template partial 5074 // specializations. This computation is slightly simpler than the 5075 // general problem of function template partial ordering, because 5076 // class template partial specializations are more constrained. We 5077 // know that every template parameter is deducible from the class 5078 // template partial specialization's template arguments, for 5079 // example. 5080 SmallVector<DeducedTemplateArgument, 4> Deduced; 5081 5082 // Determine whether P1 is at least as specialized as P2. 5083 Deduced.resize(P2->getTemplateParameters()->size()); 5084 if (DeduceTemplateArgumentsByTypeMatch(S, P2->getTemplateParameters(), 5085 T2, T1, Info, Deduced, TDF_None, 5086 /*PartialOrdering=*/true)) 5087 return false; 5088 5089 SmallVector<TemplateArgument, 4> DeducedArgs(Deduced.begin(), 5090 Deduced.end()); 5091 Sema::InstantiatingTemplate Inst(S, Info.getLocation(), P2, DeducedArgs, 5092 Info); 5093 auto *TST1 = T1->castAs<TemplateSpecializationType>(); 5094 if (FinishTemplateArgumentDeduction( 5095 S, P2, /*IsPartialOrdering=*/true, 5096 TemplateArgumentList(TemplateArgumentList::OnStack, 5097 TST1->template_arguments()), 5098 Deduced, Info)) 5099 return false; 5100 5101 return true; 5102} 5103 5104/// Returns the more specialized class template partial specialization 5105/// according to the rules of partial ordering of class template partial 5106/// specializations (C++ [temp.class.order]). 5107/// 5108/// \param PS1 the first class template partial specialization 5109/// 5110/// \param PS2 the second class template partial specialization 5111/// 5112/// \returns the more specialized class template partial specialization. If 5113/// neither partial specialization is more specialized, returns NULL. 5114ClassTemplatePartialSpecializationDecl * 5115Sema::getMoreSpecializedPartialSpecialization( 5116 ClassTemplatePartialSpecializationDecl *PS1, 5117 ClassTemplatePartialSpecializationDecl *PS2, 5118 SourceLocation Loc) { 5119 QualType PT1 = PS1->getInjectedSpecializationType(); 5120 QualType PT2 = PS2->getInjectedSpecializationType(); 5121 5122 TemplateDeductionInfo Info(Loc); 5123 bool Better1 = isAtLeastAsSpecializedAs(*this, PT1, PT2, PS2, Info); 5124 bool Better2 = isAtLeastAsSpecializedAs(*this, PT2, PT1, PS1, Info); 5125 5126 if (Better1 == Better2) 5127 return nullptr; 5128 5129 return Better1 ? PS1 : PS2; 5130} 5131 5132bool Sema::isMoreSpecializedThanPrimary( 5133 ClassTemplatePartialSpecializationDecl *Spec, TemplateDeductionInfo &Info) { 5134 ClassTemplateDecl *Primary = Spec->getSpecializedTemplate(); 5135 QualType PrimaryT = Primary->getInjectedClassNameSpecialization(); 5136 QualType PartialT = Spec->getInjectedSpecializationType(); 5137 if (!isAtLeastAsSpecializedAs(*this, PartialT, PrimaryT, Primary, Info)) 5138 return false; 5139 if (isAtLeastAsSpecializedAs(*this, PrimaryT, PartialT, Spec, Info)) { 5140 Info.clearSFINAEDiagnostic(); 5141 return false; 5142 } 5143 return true; 5144} 5145 5146VarTemplatePartialSpecializationDecl * 5147Sema::getMoreSpecializedPartialSpecialization( 5148 VarTemplatePartialSpecializationDecl *PS1, 5149 VarTemplatePartialSpecializationDecl *PS2, SourceLocation Loc) { 5150 // Pretend the variable template specializations are class template 5151 // specializations and form a fake injected class name type for comparison. 5152 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~svn374877/tools/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 5154, __PRETTY_FUNCTION__))
5153 "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~svn374877/tools/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 5154, __PRETTY_FUNCTION__))
5154 " 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~svn374877/tools/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 5154, __PRETTY_FUNCTION__))
; 5155 TemplateName Name(PS1->getSpecializedTemplate()); 5156 TemplateName CanonTemplate = Context.getCanonicalTemplateName(Name); 5157 QualType PT1 = Context.getTemplateSpecializationType( 5158 CanonTemplate, PS1->getTemplateArgs().asArray()); 5159 QualType PT2 = Context.getTemplateSpecializationType( 5160 CanonTemplate, PS2->getTemplateArgs().asArray()); 5161 5162 TemplateDeductionInfo Info(Loc); 5163 bool Better1 = isAtLeastAsSpecializedAs(*this, PT1, PT2, PS2, Info); 5164 bool Better2 = isAtLeastAsSpecializedAs(*this, PT2, PT1, PS1, Info); 5165 5166 if (Better1 == Better2) 5167 return nullptr; 5168 5169 return Better1 ? PS1 : PS2; 5170} 5171 5172bool Sema::isMoreSpecializedThanPrimary( 5173 VarTemplatePartialSpecializationDecl *Spec, TemplateDeductionInfo &Info) { 5174 TemplateDecl *Primary = Spec->getSpecializedTemplate(); 5175 // FIXME: Cache the injected template arguments rather than recomputing 5176 // them for each partial specialization. 5177 SmallVector<TemplateArgument, 8> PrimaryArgs; 5178 Context.getInjectedTemplateArgs(Primary->getTemplateParameters(), 5179 PrimaryArgs); 5180 5181 TemplateName CanonTemplate = 5182 Context.getCanonicalTemplateName(TemplateName(Primary)); 5183 QualType PrimaryT = Context.getTemplateSpecializationType( 5184 CanonTemplate, PrimaryArgs); 5185 QualType PartialT = Context.getTemplateSpecializationType( 5186 CanonTemplate, Spec->getTemplateArgs().asArray()); 5187 if (!isAtLeastAsSpecializedAs(*this, PartialT, PrimaryT, Primary, Info)) 5188 return false; 5189 if (isAtLeastAsSpecializedAs(*this, PrimaryT, PartialT, Spec, Info)) { 5190 Info.clearSFINAEDiagnostic(); 5191 return false; 5192 } 5193 return true; 5194} 5195 5196bool Sema::isTemplateTemplateParameterAtLeastAsSpecializedAs( 5197 TemplateParameterList *P, TemplateDecl *AArg, SourceLocation Loc) { 5198 // C++1z [temp.arg.template]p4: (DR 150) 5199 // A template template-parameter P is at least as specialized as a 5200 // template template-argument A if, given the following rewrite to two 5201 // function templates... 5202 5203 // Rather than synthesize function templates, we merely perform the 5204 // equivalent partial ordering by performing deduction directly on 5205 // the template parameter lists of the template template parameters. 5206 // 5207 // Given an invented class template X with the template parameter list of 5208 // A (including default arguments): 5209 TemplateName X = Context.getCanonicalTemplateName(TemplateName(AArg)); 5210 TemplateParameterList *A = AArg->getTemplateParameters(); 5211 5212 // - Each function template has a single function parameter whose type is 5213 // a specialization of X with template arguments corresponding to the 5214 // template parameters from the respective function template 5215 SmallVector<TemplateArgument, 8> AArgs; 5216 Context.getInjectedTemplateArgs(A, AArgs); 5217 5218 // Check P's arguments against A's parameter list. This will fill in default 5219 // template arguments as needed. AArgs are already correct by construction. 5220 // We can't just use CheckTemplateIdType because that will expand alias 5221 // templates. 5222 SmallVector<TemplateArgument, 4> PArgs; 5223 { 5224 SFINAETrap Trap(*this); 5225 5226 Context.getInjectedTemplateArgs(P, PArgs); 5227 TemplateArgumentListInfo PArgList(P->getLAngleLoc(), P->getRAngleLoc()); 5228 for (unsigned I = 0, N = P->size(); I != N; ++I) { 5229 // Unwrap packs that getInjectedTemplateArgs wrapped around pack 5230 // expansions, to form an "as written" argument list. 5231 TemplateArgument Arg = PArgs[I]; 5232 if (Arg.getKind() == TemplateArgument::Pack) { 5233 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~svn374877/tools/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 5233, __PRETTY_FUNCTION__))
; 5234 Arg = *Arg.pack_begin(); 5235 } 5236 PArgList.addArgument(getTrivialTemplateArgumentLoc( 5237 Arg, QualType(), P->getParam(I)->getLocation())); 5238 } 5239 PArgs.clear(); 5240 5241 // C++1z [temp.arg.template]p3: 5242 // If the rewrite produces an invalid type, then P is not at least as 5243 // specialized as A. 5244 if (CheckTemplateArgumentList(AArg, Loc, PArgList, false, PArgs) || 5245 Trap.hasErrorOccurred()) 5246 return false; 5247 } 5248 5249 QualType AType = Context.getTemplateSpecializationType(X, AArgs); 5250 QualType PType = Context.getTemplateSpecializationType(X, PArgs); 5251 5252 // ... the function template corresponding to P is at least as specialized 5253 // as the function template corresponding to A according to the partial 5254 // ordering rules for function templates. 5255 TemplateDeductionInfo Info(Loc, A->getDepth()); 5256 return isAtLeastAsSpecializedAs(*this, PType, AType, AArg, Info); 5257} 5258 5259/// Mark the template parameters that are used by the given 5260/// expression. 5261static void 5262MarkUsedTemplateParameters(ASTContext &Ctx, 5263 const Expr *E, 5264 bool OnlyDeduced, 5265 unsigned Depth, 5266 llvm::SmallBitVector &Used) { 5267 // We can deduce from a pack expansion. 5268 if (const PackExpansionExpr *Expansion = dyn_cast<PackExpansionExpr>(E)) 5269 E = Expansion->getPattern(); 5270 5271 // Skip through any implicit casts we added while type-checking, and any 5272 // substitutions performed by template alias expansion. 5273 while (true) { 5274 if (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) 5275 E = ICE->getSubExpr(); 5276 else if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(E)) 5277 E = CE->getSubExpr(); 5278 else if (const SubstNonTypeTemplateParmExpr *Subst = 5279 dyn_cast<SubstNonTypeTemplateParmExpr>(E)) 5280 E = Subst->getReplacement(); 5281 else 5282 break; 5283 } 5284 5285 // FIXME: if !OnlyDeduced, we have to walk the whole subexpression to 5286 // find other occurrences of template parameters. 5287 const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E); 5288 if (!DRE) 5289 return; 5290 5291 const NonTypeTemplateParmDecl *NTTP 5292 = dyn_cast<NonTypeTemplateParmDecl>(DRE->getDecl()); 5293 if (!NTTP) 5294 return; 5295 5296 if (NTTP->getDepth() == Depth) 5297 Used[NTTP->getIndex()] = true; 5298 5299 // In C++17 mode, additional arguments may be deduced from the type of a 5300 // non-type argument. 5301 if (Ctx.getLangOpts().CPlusPlus17) 5302 MarkUsedTemplateParameters(Ctx, NTTP->getType(), OnlyDeduced, Depth, Used); 5303} 5304 5305/// Mark the template parameters that are used by the given 5306/// nested name specifier. 5307static void 5308MarkUsedTemplateParameters(ASTContext &Ctx, 5309 NestedNameSpecifier *NNS, 5310 bool OnlyDeduced, 5311 unsigned Depth, 5312 llvm::SmallBitVector &Used) { 5313 if (!NNS) 5314 return; 5315 5316 MarkUsedTemplateParameters(Ctx, NNS->getPrefix(), OnlyDeduced, Depth, 5317 Used); 5318 MarkUsedTemplateParameters(Ctx, QualType(NNS->getAsType(), 0), 5319 OnlyDeduced, Depth, Used); 5320} 5321 5322/// Mark the template parameters that are used by the given 5323/// template name. 5324static void 5325MarkUsedTemplateParameters(ASTContext &Ctx, 5326 TemplateName Name, 5327 bool OnlyDeduced, 5328 unsigned Depth, 5329 llvm::SmallBitVector &Used) { 5330 if (TemplateDecl *Template = Name.getAsTemplateDecl()) { 5331 if (TemplateTemplateParmDecl *TTP 5332 = dyn_cast<TemplateTemplateParmDecl>(Template)) { 5333 if (TTP->getDepth() == Depth) 5334 Used[TTP->getIndex()] = true; 5335 } 5336 return; 5337 } 5338 5339 if (QualifiedTemplateName *QTN = Name.getAsQualifiedTemplateName()) 5340 MarkUsedTemplateParameters(Ctx, QTN->getQualifier(), OnlyDeduced, 5341 Depth, Used); 5342 if (DependentTemplateName *DTN = Name.getAsDependentTemplateName()) 5343 MarkUsedTemplateParameters(Ctx, DTN->getQualifier(), OnlyDeduced, 5344 Depth, Used); 5345} 5346 5347/// Mark the template parameters that are used by the given 5348/// type. 5349static void 5350MarkUsedTemplateParameters(ASTContext &Ctx, QualType T, 5351 bool OnlyDeduced, 5352 unsigned Depth, 5353 llvm::SmallBitVector &Used) { 5354 if (T.isNull()) 5355 return; 5356 5357 // Non-dependent types have nothing deducible 5358 if (!T->isDependentType()) 5359 return; 5360 5361 T = Ctx.getCanonicalType(T); 5362 switch (T->getTypeClass()) { 5363 case Type::Pointer: 5364 MarkUsedTemplateParameters(Ctx, 5365 cast<PointerType>(T)->getPointeeType(), 5366 OnlyDeduced, 5367 Depth, 5368 Used); 5369 break; 5370 5371 case Type::BlockPointer: 5372 MarkUsedTemplateParameters(Ctx, 5373 cast<BlockPointerType>(T)->getPointeeType(), 5374 OnlyDeduced, 5375 Depth, 5376 Used); 5377 break; 5378 5379 case Type::LValueReference: 5380 case Type::RValueReference: 5381 MarkUsedTemplateParameters(Ctx, 5382 cast<ReferenceType>(T)->getPointeeType(), 5383 OnlyDeduced, 5384 Depth, 5385 Used); 5386 break; 5387 5388 case Type::MemberPointer: { 5389 const MemberPointerType *MemPtr = cast<MemberPointerType>(T.getTypePtr()); 5390 MarkUsedTemplateParameters(Ctx, MemPtr->getPointeeType(), OnlyDeduced, 5391 Depth, Used); 5392 MarkUsedTemplateParameters(Ctx, QualType(MemPtr->getClass(), 0), 5393 OnlyDeduced, Depth, Used); 5394 break; 5395 } 5396 5397 case Type::DependentSizedArray: 5398 MarkUsedTemplateParameters(Ctx, 5399 cast<DependentSizedArrayType>(T)->getSizeExpr(), 5400 OnlyDeduced, Depth, Used); 5401 // Fall through to check the element type 5402 LLVM_FALLTHROUGH[[gnu::fallthrough]]; 5403 5404 case Type::ConstantArray: 5405 case Type::IncompleteArray: 5406 MarkUsedTemplateParameters(Ctx, 5407 cast<ArrayType>(T)->getElementType(), 5408 OnlyDeduced, Depth, Used); 5409 break; 5410 5411 case Type::Vector: 5412 case Type::ExtVector: 5413 MarkUsedTemplateParameters(Ctx, 5414 cast<VectorType>(T)->getElementType(), 5415 OnlyDeduced, Depth, Used); 5416 break; 5417 5418 case Type::DependentVector: { 5419 const auto *VecType = cast<DependentVectorType>(T); 5420 MarkUsedTemplateParameters(Ctx, VecType->getElementType(), OnlyDeduced, 5421 Depth, Used); 5422 MarkUsedTemplateParameters(Ctx, VecType->getSizeExpr(), OnlyDeduced, Depth, 5423 Used); 5424 break; 5425 } 5426 case Type::DependentSizedExtVector: { 5427 const DependentSizedExtVectorType *VecType 5428 = cast<DependentSizedExtVectorType>(T); 5429 MarkUsedTemplateParameters(Ctx, VecType->getElementType(), OnlyDeduced, 5430 Depth, Used); 5431 MarkUsedTemplateParameters(Ctx, VecType->getSizeExpr(), OnlyDeduced, 5432 Depth, Used); 5433 break; 5434 } 5435 5436 case Type::DependentAddressSpace: { 5437 const DependentAddressSpaceType *DependentASType = 5438 cast<DependentAddressSpaceType>(T); 5439 MarkUsedTemplateParameters(Ctx, DependentASType->getPointeeType(), 5440 OnlyDeduced, Depth, Used); 5441 MarkUsedTemplateParameters(Ctx, 5442 DependentASType->getAddrSpaceExpr(), 5443 OnlyDeduced, Depth, Used); 5444 break; 5445 } 5446 5447 case Type::FunctionProto: { 5448 const FunctionProtoType *Proto = cast<FunctionProtoType>(T); 5449 MarkUsedTemplateParameters(Ctx, Proto->getReturnType(), OnlyDeduced, Depth, 5450 Used); 5451 for (unsigned I = 0, N = Proto->getNumParams(); I != N; ++I) { 5452 // C++17 [temp.deduct.type]p5: 5453 // The non-deduced contexts are: [...] 5454 // -- A function parameter pack that does not occur at the end of the 5455 // parameter-declaration-list. 5456 if (!OnlyDeduced || I + 1 == N || 5457 !Proto->getParamType(I)->getAs<PackExpansionType>()) { 5458 MarkUsedTemplateParameters(Ctx, Proto->getParamType(I), OnlyDeduced, 5459 Depth, Used); 5460 } else { 5461 // FIXME: C++17 [temp.deduct.call]p1: 5462 // When a function parameter pack appears in a non-deduced context, 5463 // the type of that pack is never deduced. 5464 // 5465 // We should also track a set of "never deduced" parameters, and 5466 // subtract that from the list of deduced parameters after marking. 5467 } 5468 } 5469 if (auto *E = Proto->getNoexceptExpr()) 5470 MarkUsedTemplateParameters(Ctx, E, OnlyDeduced, Depth, Used); 5471 break; 5472 } 5473 5474 case Type::TemplateTypeParm: { 5475 const TemplateTypeParmType *TTP = cast<TemplateTypeParmType>(T); 5476 if (TTP->getDepth() == Depth) 5477 Used[TTP->getIndex()] = true; 5478 break; 5479 } 5480 5481 case Type::SubstTemplateTypeParmPack: { 5482 const SubstTemplateTypeParmPackType *Subst 5483 = cast<SubstTemplateTypeParmPackType>(T); 5484 MarkUsedTemplateParameters(Ctx, 5485 QualType(Subst->getReplacedParameter(), 0), 5486 OnlyDeduced, Depth, Used); 5487 MarkUsedTemplateParameters(Ctx, Subst->getArgumentPack(), 5488 OnlyDeduced, Depth, Used); 5489 break; 5490 } 5491 5492 case Type::InjectedClassName: 5493 T = cast<InjectedClassNameType>(T)->getInjectedSpecializationType(); 5494 LLVM_FALLTHROUGH[[gnu::fallthrough]]; 5495 5496 case Type::TemplateSpecialization: { 5497 const TemplateSpecializationType *Spec 5498 = cast<TemplateSpecializationType>(T); 5499 MarkUsedTemplateParameters(Ctx, Spec->getTemplateName(), OnlyDeduced, 5500 Depth, Used); 5501 5502 // C++0x [temp.deduct.type]p9: 5503 // If the template argument list of P contains a pack expansion that is 5504 // not the last template argument, the entire template argument list is a 5505 // non-deduced context. 5506 if (OnlyDeduced && 5507 hasPackExpansionBeforeEnd(Spec->template_arguments())) 5508 break; 5509 5510 for (unsigned I = 0, N = Spec->getNumArgs(); I != N; ++I) 5511 MarkUsedTemplateParameters(Ctx, Spec->getArg(I), OnlyDeduced, Depth, 5512 Used); 5513 break; 5514 } 5515 5516 case Type::Complex: 5517 if (!OnlyDeduced) 5518 MarkUsedTemplateParameters(Ctx, 5519 cast<ComplexType>(T)->getElementType(), 5520 OnlyDeduced, Depth, Used); 5521 break; 5522 5523 case Type::Atomic: 5524 if (!OnlyDeduced) 5525 MarkUsedTemplateParameters(Ctx, 5526 cast<AtomicType>(T)->getValueType(), 5527 OnlyDeduced, Depth, Used); 5528 break; 5529 5530 case Type::DependentName: 5531 if (!OnlyDeduced) 5532 MarkUsedTemplateParameters(Ctx, 5533 cast<DependentNameType>(T)->getQualifier(), 5534 OnlyDeduced, Depth, Used); 5535 break; 5536 5537 case Type::DependentTemplateSpecialization: { 5538 // C++14 [temp.deduct.type]p5: 5539 // The non-deduced contexts are: 5540 // -- The nested-name-specifier of a type that was specified using a 5541 // qualified-id 5542 // 5543 // C++14 [temp.deduct.type]p6: 5544 // When a type name is specified in a way that includes a non-deduced 5545 // context, all of the types that comprise that type name are also 5546 // non-deduced. 5547 if (OnlyDeduced) 5548 break; 5549 5550 const DependentTemplateSpecializationType *Spec 5551 = cast<DependentTemplateSpecializationType>(T); 5552 5553 MarkUsedTemplateParameters(Ctx, Spec->getQualifier(), 5554 OnlyDeduced, Depth, Used); 5555 5556 for (unsigned I = 0, N = Spec->getNumArgs(); I != N; ++I) 5557 MarkUsedTemplateParameters(Ctx, Spec->getArg(I), OnlyDeduced, Depth, 5558 Used); 5559 break; 5560 } 5561 5562 case Type::TypeOf: 5563 if (!OnlyDeduced) 5564 MarkUsedTemplateParameters(Ctx, 5565 cast<TypeOfType>(T)->getUnderlyingType(), 5566 OnlyDeduced, Depth, Used); 5567 break; 5568 5569 case Type::TypeOfExpr: 5570 if (!OnlyDeduced) 5571 MarkUsedTemplateParameters(Ctx, 5572 cast<TypeOfExprType>(T)->getUnderlyingExpr(), 5573 OnlyDeduced, Depth, Used); 5574 break; 5575 5576 case Type::Decltype: 5577 if (!OnlyDeduced) 5578 MarkUsedTemplateParameters(Ctx, 5579 cast<DecltypeType>(T)->getUnderlyingExpr(), 5580 OnlyDeduced, Depth, Used); 5581 break; 5582 5583 case Type::UnaryTransform: 5584 if (!OnlyDeduced) 5585 MarkUsedTemplateParameters(Ctx, 5586 cast<UnaryTransformType>(T)->getUnderlyingType(), 5587 OnlyDeduced, Depth, Used); 5588 break; 5589 5590 case Type::PackExpansion: 5591 MarkUsedTemplateParameters(Ctx, 5592 cast<PackExpansionType>(T)->getPattern(), 5593 OnlyDeduced, Depth, Used); 5594 break; 5595 5596 case Type::Auto: 5597 case Type::DeducedTemplateSpecialization: 5598 MarkUsedTemplateParameters(Ctx, 5599 cast<DeducedType>(T)->getDeducedType(), 5600 OnlyDeduced, Depth, Used); 5601 break; 5602 5603 // None of these types have any template parameters in them. 5604 case Type::Builtin: 5605 case Type::VariableArray: 5606 case Type::FunctionNoProto: 5607 case Type::Record: 5608 case Type::Enum: 5609 case Type::ObjCInterface: 5610 case Type::ObjCObject: 5611 case Type::ObjCObjectPointer: 5612 case Type::UnresolvedUsing: 5613 case Type::Pipe: 5614#define TYPE(Class, Base) 5615#define ABSTRACT_TYPE(Class, Base) 5616#define DEPENDENT_TYPE(Class, Base) 5617#define NON_CANONICAL_TYPE(Class, Base) case Type::Class: 5618#include "clang/AST/TypeNodes.inc" 5619 break; 5620 } 5621} 5622 5623/// Mark the template parameters that are used by this 5624/// template argument. 5625static void 5626MarkUsedTemplateParameters(ASTContext &Ctx, 5627 const TemplateArgument &TemplateArg, 5628 bool OnlyDeduced, 5629 unsigned Depth, 5630 llvm::SmallBitVector &Used) { 5631 switch (TemplateArg.getKind()) { 5632 case TemplateArgument::Null: 5633 case TemplateArgument::Integral: 5634 case TemplateArgument::Declaration: 5635 break; 5636 5637 case TemplateArgument::NullPtr: 5638 MarkUsedTemplateParameters(Ctx, TemplateArg.getNullPtrType(), OnlyDeduced, 5639 Depth, Used); 5640 break; 5641 5642 case TemplateArgument::Type: 5643 MarkUsedTemplateParameters(Ctx, TemplateArg.getAsType(), OnlyDeduced, 5644 Depth, Used); 5645 break; 5646 5647 case TemplateArgument::Template: 5648 case TemplateArgument::TemplateExpansion: 5649 MarkUsedTemplateParameters(Ctx, 5650 TemplateArg.getAsTemplateOrTemplatePattern(), 5651 OnlyDeduced, Depth, Used); 5652 break; 5653 5654 case TemplateArgument::Expression: 5655 MarkUsedTemplateParameters(Ctx, TemplateArg.getAsExpr(), OnlyDeduced, 5656 Depth, Used); 5657 break; 5658 5659 case TemplateArgument::Pack: 5660 for (const auto &P : TemplateArg.pack_elements()) 5661 MarkUsedTemplateParameters(Ctx, P, OnlyDeduced, Depth, Used); 5662 break; 5663 } 5664} 5665 5666/// Mark which template parameters can be deduced from a given 5667/// template argument list. 5668/// 5669/// \param TemplateArgs the template argument list from which template 5670/// parameters will be deduced. 5671/// 5672/// \param Used a bit vector whose elements will be set to \c true 5673/// to indicate when the corresponding template parameter will be 5674/// deduced. 5675void 5676Sema::MarkUsedTemplateParameters(const TemplateArgumentList &TemplateArgs, 5677 bool OnlyDeduced, unsigned Depth, 5678 llvm::SmallBitVector &Used) { 5679 // C++0x [temp.deduct.type]p9: 5680 // If the template argument list of P contains a pack expansion that is not 5681 // the last template argument, the entire template argument list is a 5682 // non-deduced context. 5683 if (OnlyDeduced && 5684 hasPackExpansionBeforeEnd(TemplateArgs.asArray())) 5685 return; 5686 5687 for (unsigned I = 0, N = TemplateArgs.size(); I != N; ++I) 5688 ::MarkUsedTemplateParameters(Context, TemplateArgs[I], OnlyDeduced, 5689 Depth, Used); 5690} 5691 5692/// Marks all of the template parameters that will be deduced by a 5693/// call to the given function template. 5694void Sema::MarkDeducedTemplateParameters( 5695 ASTContext &Ctx, const FunctionTemplateDecl *FunctionTemplate, 5696 llvm::SmallBitVector &Deduced) { 5697 TemplateParameterList *TemplateParams 5698 = FunctionTemplate->getTemplateParameters(); 5699 Deduced.clear(); 5700 Deduced.resize(TemplateParams->size()); 5701 5702 FunctionDecl *Function = FunctionTemplate->getTemplatedDecl(); 5703 for (unsigned I = 0, N = Function->getNumParams(); I != N; ++I) 5704 ::MarkUsedTemplateParameters(Ctx, Function->getParamDecl(I)->getType(), 5705 true, TemplateParams->getDepth(), Deduced); 5706} 5707 5708bool hasDeducibleTemplateParameters(Sema &S, 5709 FunctionTemplateDecl *FunctionTemplate, 5710 QualType T) { 5711 if (!T->isDependentType()) 5712 return false; 5713 5714 TemplateParameterList *TemplateParams 5715 = FunctionTemplate->getTemplateParameters(); 5716 llvm::SmallBitVector Deduced(TemplateParams->size()); 5717 ::MarkUsedTemplateParameters(S.Context, T, true, TemplateParams->getDepth(), 5718 Deduced); 5719 5720 return Deduced.any(); 5721}

/build/llvm-toolchain-snapshot-10~svn374877/tools/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;
194 R.Mask &= ~Q.Mask;
195 return Q;
196 }
197
198 Qualifiers Q;