Bug Summary

File:tools/clang/lib/Sema/SemaTemplateDeduction.cpp
Warning:line 755, column 3
Potential leak of memory pointed to by 'SawIndices.X'

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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 -mrelocation-model pic -pic-level 2 -mthread-model posix -relaxed-aliasing -fmath-errno -masm-verbose -mconstructor-aliases -munwind-tables -fuse-init-array -target-cpu x86-64 -dwarf-column-info -debugger-tuning=gdb -momit-leaf-frame-pointer -ffunction-sections -fdata-sections -resource-dir /usr/lib/llvm-8/lib/clang/8.0.0 -D _DEBUG -D _GNU_SOURCE -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D __STDC_LIMIT_MACROS -I /build/llvm-toolchain-snapshot-8~svn345461/build-llvm/tools/clang/lib/Sema -I /build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/Sema -I /build/llvm-toolchain-snapshot-8~svn345461/tools/clang/include -I /build/llvm-toolchain-snapshot-8~svn345461/build-llvm/tools/clang/include -I /build/llvm-toolchain-snapshot-8~svn345461/build-llvm/include -I /build/llvm-toolchain-snapshot-8~svn345461/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/include/clang/8.0.0/include/ -internal-isystem /usr/local/include -internal-isystem /usr/lib/llvm-8/lib/clang/8.0.0/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++11 -fdeprecated-macro -fdebug-compilation-dir /build/llvm-toolchain-snapshot-8~svn345461/build-llvm/tools/clang/lib/Sema -ferror-limit 19 -fmessage-length 0 -fvisibility-inlines-hidden -fobjc-runtime=gcc -fno-common -fdiagnostics-show-option -vectorize-loops -vectorize-slp -analyzer-output=html -analyzer-config stable-report-filename=true -o /tmp/scan-build-2018-10-27-211344-32123-1 -x c++ /build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/Sema/SemaTemplateDeduction.cpp -faddrsig

/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/Sema/SemaTemplateDeduction.cpp

1//===- SemaTemplateDeduction.cpp - Template Argument Deduction ------------===//
2//
3// The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This file implements C++ template argument deduction.
11//
12//===----------------------------------------------------------------------===//
13
14#include "clang/Sema/TemplateDeduction.h"
15#include "TreeTransform.h"
16#include "TypeLocBuilder.h"
17#include "clang/AST/ASTContext.h"
18#include "clang/AST/ASTLambda.h"
19#include "clang/AST/Decl.h"
20#include "clang/AST/DeclAccessPair.h"
21#include "clang/AST/DeclBase.h"
22#include "clang/AST/DeclCXX.h"
23#include "clang/AST/DeclTemplate.h"
24#include "clang/AST/DeclarationName.h"
25#include "clang/AST/Expr.h"
26#include "clang/AST/ExprCXX.h"
27#include "clang/AST/NestedNameSpecifier.h"
28#include "clang/AST/TemplateBase.h"
29#include "clang/AST/TemplateName.h"
30#include "clang/AST/Type.h"
31#include "clang/AST/TypeLoc.h"
32#include "clang/AST/UnresolvedSet.h"
33#include "clang/Basic/AddressSpaces.h"
34#include "clang/Basic/ExceptionSpecificationType.h"
35#include "clang/Basic/LLVM.h"
36#include "clang/Basic/LangOptions.h"
37#include "clang/Basic/PartialDiagnostic.h"
38#include "clang/Basic/SourceLocation.h"
39#include "clang/Basic/Specifiers.h"
40#include "clang/Sema/Ownership.h"
41#include "clang/Sema/Sema.h"
42#include "clang/Sema/Template.h"
43#include "llvm/ADT/APInt.h"
44#include "llvm/ADT/APSInt.h"
45#include "llvm/ADT/ArrayRef.h"
46#include "llvm/ADT/DenseMap.h"
47#include "llvm/ADT/FoldingSet.h"
48#include "llvm/ADT/Optional.h"
49#include "llvm/ADT/SmallBitVector.h"
50#include "llvm/ADT/SmallPtrSet.h"
51#include "llvm/ADT/SmallVector.h"
52#include "llvm/Support/Casting.h"
53#include "llvm/Support/Compiler.h"
54#include "llvm/Support/ErrorHandling.h"
55#include <algorithm>
56#include <cassert>
57#include <tuple>
58#include <utility>
59
60namespace clang {
61
62 /// Various flags that control template argument deduction.
63 ///
64 /// These flags can be bitwise-OR'd together.
65 enum TemplateDeductionFlags {
66 /// No template argument deduction flags, which indicates the
67 /// strictest results for template argument deduction (as used for, e.g.,
68 /// matching class template partial specializations).
69 TDF_None = 0,
70
71 /// Within template argument deduction from a function call, we are
72 /// matching with a parameter type for which the original parameter was
73 /// a reference.
74 TDF_ParamWithReferenceType = 0x1,
75
76 /// Within template argument deduction from a function call, we
77 /// are matching in a case where we ignore cv-qualifiers.
78 TDF_IgnoreQualifiers = 0x02,
79
80 /// Within template argument deduction from a function call,
81 /// we are matching in a case where we can perform template argument
82 /// deduction from a template-id of a derived class of the argument type.
83 TDF_DerivedClass = 0x04,
84
85 /// Allow non-dependent types to differ, e.g., when performing
86 /// template argument deduction from a function call where conversions
87 /// may apply.
88 TDF_SkipNonDependent = 0x08,
89
90 /// Whether we are performing template argument deduction for
91 /// parameters and arguments in a top-level template argument
92 TDF_TopLevelParameterTypeList = 0x10,
93
94 /// Within template argument deduction from overload resolution per
95 /// C++ [over.over] allow matching function types that are compatible in
96 /// terms of noreturn and default calling convention adjustments, or
97 /// similarly matching a declared template specialization against a
98 /// possible template, per C++ [temp.deduct.decl]. In either case, permit
99 /// deduction where the parameter is a function type that can be converted
100 /// to the argument type.
101 TDF_AllowCompatibleFunctionType = 0x20,
102
103 /// Within template argument deduction for a conversion function, we are
104 /// matching with an argument type for which the original argument was
105 /// a reference.
106 TDF_ArgWithReferenceType = 0x40,
107 };
108}
109
110using namespace clang;
111using namespace sema;
112
113/// Compare two APSInts, extending and switching the sign as
114/// necessary to compare their values regardless of underlying type.
115static bool hasSameExtendedValue(llvm::APSInt X, llvm::APSInt Y) {
116 if (Y.getBitWidth() > X.getBitWidth())
117 X = X.extend(Y.getBitWidth());
118 else if (Y.getBitWidth() < X.getBitWidth())
119 Y = Y.extend(X.getBitWidth());
120
121 // If there is a signedness mismatch, correct it.
122 if (X.isSigned() != Y.isSigned()) {
123 // If the signed value is negative, then the values cannot be the same.
124 if ((Y.isSigned() && Y.isNegative()) || (X.isSigned() && X.isNegative()))
125 return false;
126
127 Y.setIsSigned(true);
128 X.setIsSigned(true);
129 }
130
131 return X == Y;
132}
133
134static Sema::TemplateDeductionResult
135DeduceTemplateArguments(Sema &S,
136 TemplateParameterList *TemplateParams,
137 const TemplateArgument &Param,
138 TemplateArgument Arg,
139 TemplateDeductionInfo &Info,
140 SmallVectorImpl<DeducedTemplateArgument> &Deduced);
141
142static Sema::TemplateDeductionResult
143DeduceTemplateArgumentsByTypeMatch(Sema &S,
144 TemplateParameterList *TemplateParams,
145 QualType Param,
146 QualType Arg,
147 TemplateDeductionInfo &Info,
148 SmallVectorImpl<DeducedTemplateArgument> &
149 Deduced,
150 unsigned TDF,
151 bool PartialOrdering = false,
152 bool DeducedFromArrayBound = false);
153
154static Sema::TemplateDeductionResult
155DeduceTemplateArguments(Sema &S, TemplateParameterList *TemplateParams,
156 ArrayRef<TemplateArgument> Params,
157 ArrayRef<TemplateArgument> Args,
158 TemplateDeductionInfo &Info,
159 SmallVectorImpl<DeducedTemplateArgument> &Deduced,
160 bool NumberOfArgumentsMustMatch);
161
162static void MarkUsedTemplateParameters(ASTContext &Ctx,
163 const TemplateArgument &TemplateArg,
164 bool OnlyDeduced, unsigned Depth,
165 llvm::SmallBitVector &Used);
166
167static void MarkUsedTemplateParameters(ASTContext &Ctx, QualType T,
168 bool OnlyDeduced, unsigned Level,
169 llvm::SmallBitVector &Deduced);
170
171/// If the given expression is of a form that permits the deduction
172/// of a non-type template parameter, return the declaration of that
173/// non-type template parameter.
174static NonTypeTemplateParmDecl *
175getDeducedParameterFromExpr(TemplateDeductionInfo &Info, Expr *E) {
176 // If we are within an alias template, the expression may have undergone
177 // any number of parameter substitutions already.
178 while (true) {
179 if (ImplicitCastExpr *IC = dyn_cast<ImplicitCastExpr>(E))
180 E = IC->getSubExpr();
181 else if (SubstNonTypeTemplateParmExpr *Subst =
182 dyn_cast<SubstNonTypeTemplateParmExpr>(E))
183 E = Subst->getReplacement();
184 else
185 break;
186 }
187
188 if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E))
189 if (auto *NTTP = dyn_cast<NonTypeTemplateParmDecl>(DRE->getDecl()))
190 if (NTTP->getDepth() == Info.getDeducedDepth())
191 return NTTP;
192
193 return nullptr;
194}
195
196/// Determine whether two declaration pointers refer to the same
197/// declaration.
198static bool isSameDeclaration(Decl *X, Decl *Y) {
199 if (NamedDecl *NX = dyn_cast<NamedDecl>(X))
200 X = NX->getUnderlyingDecl();
201 if (NamedDecl *NY = dyn_cast<NamedDecl>(Y))
202 Y = NY->getUnderlyingDecl();
203
204 return X->getCanonicalDecl() == Y->getCanonicalDecl();
205}
206
207/// Verify that the given, deduced template arguments are compatible.
208///
209/// \returns The deduced template argument, or a NULL template argument if
210/// the deduced template arguments were incompatible.
211static DeducedTemplateArgument
212checkDeducedTemplateArguments(ASTContext &Context,
213 const DeducedTemplateArgument &X,
214 const DeducedTemplateArgument &Y) {
215 // We have no deduction for one or both of the arguments; they're compatible.
216 if (X.isNull())
217 return Y;
218 if (Y.isNull())
219 return X;
220
221 // If we have two non-type template argument values deduced for the same
222 // parameter, they must both match the type of the parameter, and thus must
223 // match each other's type. As we're only keeping one of them, we must check
224 // for that now. The exception is that if either was deduced from an array
225 // bound, the type is permitted to differ.
226 if (!X.wasDeducedFromArrayBound() && !Y.wasDeducedFromArrayBound()) {
227 QualType XType = X.getNonTypeTemplateArgumentType();
228 if (!XType.isNull()) {
229 QualType YType = Y.getNonTypeTemplateArgumentType();
230 if (YType.isNull() || !Context.hasSameType(XType, YType))
231 return DeducedTemplateArgument();
232 }
233 }
234
235 switch (X.getKind()) {
236 case TemplateArgument::Null:
237 llvm_unreachable("Non-deduced template arguments handled above")::llvm::llvm_unreachable_internal("Non-deduced template arguments handled above"
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 237)
;
238
239 case TemplateArgument::Type:
240 // If two template type arguments have the same type, they're compatible.
241 if (Y.getKind() == TemplateArgument::Type &&
242 Context.hasSameType(X.getAsType(), Y.getAsType()))
243 return X;
244
245 // If one of the two arguments was deduced from an array bound, the other
246 // supersedes it.
247 if (X.wasDeducedFromArrayBound() != Y.wasDeducedFromArrayBound())
248 return X.wasDeducedFromArrayBound() ? Y : X;
249
250 // The arguments are not compatible.
251 return DeducedTemplateArgument();
252
253 case TemplateArgument::Integral:
254 // If we deduced a constant in one case and either a dependent expression or
255 // declaration in another case, keep the integral constant.
256 // If both are integral constants with the same value, keep that value.
257 if (Y.getKind() == TemplateArgument::Expression ||
258 Y.getKind() == TemplateArgument::Declaration ||
259 (Y.getKind() == TemplateArgument::Integral &&
260 hasSameExtendedValue(X.getAsIntegral(), Y.getAsIntegral())))
261 return X.wasDeducedFromArrayBound() ? Y : X;
262
263 // All other combinations are incompatible.
264 return DeducedTemplateArgument();
265
266 case TemplateArgument::Template:
267 if (Y.getKind() == TemplateArgument::Template &&
268 Context.hasSameTemplateName(X.getAsTemplate(), Y.getAsTemplate()))
269 return X;
270
271 // All other combinations are incompatible.
272 return DeducedTemplateArgument();
273
274 case TemplateArgument::TemplateExpansion:
275 if (Y.getKind() == TemplateArgument::TemplateExpansion &&
276 Context.hasSameTemplateName(X.getAsTemplateOrTemplatePattern(),
277 Y.getAsTemplateOrTemplatePattern()))
278 return X;
279
280 // All other combinations are incompatible.
281 return DeducedTemplateArgument();
282
283 case TemplateArgument::Expression: {
284 if (Y.getKind() != TemplateArgument::Expression)
285 return checkDeducedTemplateArguments(Context, Y, X);
286
287 // Compare the expressions for equality
288 llvm::FoldingSetNodeID ID1, ID2;
289 X.getAsExpr()->Profile(ID1, Context, true);
290 Y.getAsExpr()->Profile(ID2, Context, true);
291 if (ID1 == ID2)
292 return X.wasDeducedFromArrayBound() ? Y : X;
293
294 // Differing dependent expressions are incompatible.
295 return DeducedTemplateArgument();
296 }
297
298 case TemplateArgument::Declaration:
299 assert(!X.wasDeducedFromArrayBound())((!X.wasDeducedFromArrayBound()) ? static_cast<void> (0
) : __assert_fail ("!X.wasDeducedFromArrayBound()", "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 299, __PRETTY_FUNCTION__))
;
300
301 // If we deduced a declaration and a dependent expression, keep the
302 // declaration.
303 if (Y.getKind() == TemplateArgument::Expression)
304 return X;
305
306 // If we deduced a declaration and an integral constant, keep the
307 // integral constant and whichever type did not come from an array
308 // bound.
309 if (Y.getKind() == TemplateArgument::Integral) {
310 if (Y.wasDeducedFromArrayBound())
311 return TemplateArgument(Context, Y.getAsIntegral(),
312 X.getParamTypeForDecl());
313 return Y;
314 }
315
316 // If we deduced two declarations, make sure that they refer to the
317 // same declaration.
318 if (Y.getKind() == TemplateArgument::Declaration &&
319 isSameDeclaration(X.getAsDecl(), Y.getAsDecl()))
320 return X;
321
322 // All other combinations are incompatible.
323 return DeducedTemplateArgument();
324
325 case TemplateArgument::NullPtr:
326 // If we deduced a null pointer and a dependent expression, keep the
327 // null pointer.
328 if (Y.getKind() == TemplateArgument::Expression)
329 return X;
330
331 // If we deduced a null pointer and an integral constant, keep the
332 // integral constant.
333 if (Y.getKind() == TemplateArgument::Integral)
334 return Y;
335
336 // If we deduced two null pointers, they are the same.
337 if (Y.getKind() == TemplateArgument::NullPtr)
338 return X;
339
340 // All other combinations are incompatible.
341 return DeducedTemplateArgument();
342
343 case TemplateArgument::Pack: {
344 if (Y.getKind() != TemplateArgument::Pack ||
345 X.pack_size() != Y.pack_size())
346 return DeducedTemplateArgument();
347
348 llvm::SmallVector<TemplateArgument, 8> NewPack;
349 for (TemplateArgument::pack_iterator XA = X.pack_begin(),
350 XAEnd = X.pack_end(),
351 YA = Y.pack_begin();
352 XA != XAEnd; ++XA, ++YA) {
353 TemplateArgument Merged = checkDeducedTemplateArguments(
354 Context, DeducedTemplateArgument(*XA, X.wasDeducedFromArrayBound()),
355 DeducedTemplateArgument(*YA, Y.wasDeducedFromArrayBound()));
356 if (Merged.isNull())
357 return DeducedTemplateArgument();
358 NewPack.push_back(Merged);
359 }
360
361 return DeducedTemplateArgument(
362 TemplateArgument::CreatePackCopy(Context, NewPack),
363 X.wasDeducedFromArrayBound() && Y.wasDeducedFromArrayBound());
364 }
365 }
366
367 llvm_unreachable("Invalid TemplateArgument Kind!")::llvm::llvm_unreachable_internal("Invalid TemplateArgument Kind!"
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 367)
;
368}
369
370/// Deduce the value of the given non-type template parameter
371/// as the given deduced template argument. All non-type template parameter
372/// deduction is funneled through here.
373static Sema::TemplateDeductionResult DeduceNonTypeTemplateArgument(
374 Sema &S, TemplateParameterList *TemplateParams,
375 NonTypeTemplateParmDecl *NTTP, const DeducedTemplateArgument &NewDeduced,
376 QualType ValueType, TemplateDeductionInfo &Info,
377 SmallVectorImpl<DeducedTemplateArgument> &Deduced) {
378 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-8~svn345461/tools/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 379, __PRETTY_FUNCTION__))
379 "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-8~svn345461/tools/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 379, __PRETTY_FUNCTION__))
;
380
381 DeducedTemplateArgument Result = checkDeducedTemplateArguments(
382 S.Context, Deduced[NTTP->getIndex()], NewDeduced);
383 if (Result.isNull()) {
384 Info.Param = NTTP;
385 Info.FirstArg = Deduced[NTTP->getIndex()];
386 Info.SecondArg = NewDeduced;
387 return Sema::TDK_Inconsistent;
388 }
389
390 Deduced[NTTP->getIndex()] = Result;
391 if (!S.getLangOpts().CPlusPlus17)
392 return Sema::TDK_Success;
393
394 if (NTTP->isExpandedParameterPack())
395 // FIXME: We may still need to deduce parts of the type here! But we
396 // don't have any way to find which slice of the type to use, and the
397 // type stored on the NTTP itself is nonsense. Perhaps the type of an
398 // expanded NTTP should be a pack expansion type?
399 return Sema::TDK_Success;
400
401 // Get the type of the parameter for deduction. If it's a (dependent) array
402 // or function type, we will not have decayed it yet, so do that now.
403 QualType ParamType = S.Context.getAdjustedParameterType(NTTP->getType());
404 if (auto *Expansion = dyn_cast<PackExpansionType>(ParamType))
405 ParamType = Expansion->getPattern();
406
407 // FIXME: It's not clear how deduction of a parameter of reference
408 // type from an argument (of non-reference type) should be performed.
409 // For now, we just remove reference types from both sides and let
410 // the final check for matching types sort out the mess.
411 return DeduceTemplateArgumentsByTypeMatch(
412 S, TemplateParams, ParamType.getNonReferenceType(),
413 ValueType.getNonReferenceType(), Info, Deduced, TDF_SkipNonDependent,
414 /*PartialOrdering=*/false,
415 /*ArrayBound=*/NewDeduced.wasDeducedFromArrayBound());
416}
417
418/// Deduce the value of the given non-type template parameter
419/// from the given integral constant.
420static Sema::TemplateDeductionResult DeduceNonTypeTemplateArgument(
421 Sema &S, TemplateParameterList *TemplateParams,
422 NonTypeTemplateParmDecl *NTTP, const llvm::APSInt &Value,
423 QualType ValueType, bool DeducedFromArrayBound, TemplateDeductionInfo &Info,
424 SmallVectorImpl<DeducedTemplateArgument> &Deduced) {
425 return DeduceNonTypeTemplateArgument(
426 S, TemplateParams, NTTP,
427 DeducedTemplateArgument(S.Context, Value, ValueType,
428 DeducedFromArrayBound),
429 ValueType, Info, Deduced);
430}
431
432/// Deduce the value of the given non-type template parameter
433/// from the given null pointer template argument type.
434static Sema::TemplateDeductionResult DeduceNullPtrTemplateArgument(
435 Sema &S, TemplateParameterList *TemplateParams,
436 NonTypeTemplateParmDecl *NTTP, QualType NullPtrType,
437 TemplateDeductionInfo &Info,
438 SmallVectorImpl<DeducedTemplateArgument> &Deduced) {
439 Expr *Value =
440 S.ImpCastExprToType(new (S.Context) CXXNullPtrLiteralExpr(
441 S.Context.NullPtrTy, NTTP->getLocation()),
442 NullPtrType, CK_NullToPointer)
443 .get();
444 return DeduceNonTypeTemplateArgument(S, TemplateParams, NTTP,
445 DeducedTemplateArgument(Value),
446 Value->getType(), Info, Deduced);
447}
448
449/// Deduce the value of the given non-type template parameter
450/// from the given type- or value-dependent expression.
451///
452/// \returns true if deduction succeeded, false otherwise.
453static Sema::TemplateDeductionResult DeduceNonTypeTemplateArgument(
454 Sema &S, TemplateParameterList *TemplateParams,
455 NonTypeTemplateParmDecl *NTTP, Expr *Value, TemplateDeductionInfo &Info,
456 SmallVectorImpl<DeducedTemplateArgument> &Deduced) {
457 return DeduceNonTypeTemplateArgument(S, TemplateParams, NTTP,
458 DeducedTemplateArgument(Value),
459 Value->getType(), Info, Deduced);
460}
461
462/// Deduce the value of the given non-type template parameter
463/// from the given declaration.
464///
465/// \returns true if deduction succeeded, false otherwise.
466static Sema::TemplateDeductionResult DeduceNonTypeTemplateArgument(
467 Sema &S, TemplateParameterList *TemplateParams,
468 NonTypeTemplateParmDecl *NTTP, ValueDecl *D, QualType T,
469 TemplateDeductionInfo &Info,
470 SmallVectorImpl<DeducedTemplateArgument> &Deduced) {
471 D = D ? cast<ValueDecl>(D->getCanonicalDecl()) : nullptr;
472 TemplateArgument New(D, T);
473 return DeduceNonTypeTemplateArgument(
474 S, TemplateParams, NTTP, DeducedTemplateArgument(New), T, Info, Deduced);
475}
476
477static Sema::TemplateDeductionResult
478DeduceTemplateArguments(Sema &S,
479 TemplateParameterList *TemplateParams,
480 TemplateName Param,
481 TemplateName Arg,
482 TemplateDeductionInfo &Info,
483 SmallVectorImpl<DeducedTemplateArgument> &Deduced) {
484 TemplateDecl *ParamDecl = Param.getAsTemplateDecl();
485 if (!ParamDecl) {
486 // The parameter type is dependent and is not a template template parameter,
487 // so there is nothing that we can deduce.
488 return Sema::TDK_Success;
489 }
490
491 if (TemplateTemplateParmDecl *TempParam
492 = dyn_cast<TemplateTemplateParmDecl>(ParamDecl)) {
493 // If we're not deducing at this depth, there's nothing to deduce.
494 if (TempParam->getDepth() != Info.getDeducedDepth())
495 return Sema::TDK_Success;
496
497 DeducedTemplateArgument NewDeduced(S.Context.getCanonicalTemplateName(Arg));
498 DeducedTemplateArgument Result = checkDeducedTemplateArguments(S.Context,
499 Deduced[TempParam->getIndex()],
500 NewDeduced);
501 if (Result.isNull()) {
502 Info.Param = TempParam;
503 Info.FirstArg = Deduced[TempParam->getIndex()];
504 Info.SecondArg = NewDeduced;
505 return Sema::TDK_Inconsistent;
506 }
507
508 Deduced[TempParam->getIndex()] = Result;
509 return Sema::TDK_Success;
510 }
511
512 // Verify that the two template names are equivalent.
513 if (S.Context.hasSameTemplateName(Param, Arg))
514 return Sema::TDK_Success;
515
516 // Mismatch of non-dependent template parameter to argument.
517 Info.FirstArg = TemplateArgument(Param);
518 Info.SecondArg = TemplateArgument(Arg);
519 return Sema::TDK_NonDeducedMismatch;
520}
521
522/// Deduce the template arguments by comparing the template parameter
523/// type (which is a template-id) with the template argument type.
524///
525/// \param S the Sema
526///
527/// \param TemplateParams the template parameters that we are deducing
528///
529/// \param Param the parameter type
530///
531/// \param Arg the argument type
532///
533/// \param Info information about the template argument deduction itself
534///
535/// \param Deduced the deduced template arguments
536///
537/// \returns the result of template argument deduction so far. Note that a
538/// "success" result means that template argument deduction has not yet failed,
539/// but it may still fail, later, for other reasons.
540static Sema::TemplateDeductionResult
541DeduceTemplateArguments(Sema &S,
542 TemplateParameterList *TemplateParams,
543 const TemplateSpecializationType *Param,
544 QualType Arg,
545 TemplateDeductionInfo &Info,
546 SmallVectorImpl<DeducedTemplateArgument> &Deduced) {
547 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-8~svn345461/tools/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 547, __PRETTY_FUNCTION__))
;
548
549 // Treat an injected-class-name as its underlying template-id.
550 if (auto *Injected = dyn_cast<InjectedClassNameType>(Arg))
551 Arg = Injected->getInjectedSpecializationType();
552
553 // Check whether the template argument is a dependent template-id.
554 if (const TemplateSpecializationType *SpecArg
555 = dyn_cast<TemplateSpecializationType>(Arg)) {
556 // Perform template argument deduction for the template name.
557 if (Sema::TemplateDeductionResult Result
558 = DeduceTemplateArguments(S, TemplateParams,
559 Param->getTemplateName(),
560 SpecArg->getTemplateName(),
561 Info, Deduced))
562 return Result;
563
564
565 // Perform template argument deduction on each template
566 // argument. Ignore any missing/extra arguments, since they could be
567 // filled in by default arguments.
568 return DeduceTemplateArguments(S, TemplateParams,
569 Param->template_arguments(),
570 SpecArg->template_arguments(), Info, Deduced,
571 /*NumberOfArgumentsMustMatch=*/false);
572 }
573
574 // If the argument type is a class template specialization, we
575 // perform template argument deduction using its template
576 // arguments.
577 const RecordType *RecordArg = dyn_cast<RecordType>(Arg);
578 if (!RecordArg) {
579 Info.FirstArg = TemplateArgument(QualType(Param, 0));
580 Info.SecondArg = TemplateArgument(Arg);
581 return Sema::TDK_NonDeducedMismatch;
582 }
583
584 ClassTemplateSpecializationDecl *SpecArg
585 = dyn_cast<ClassTemplateSpecializationDecl>(RecordArg->getDecl());
586 if (!SpecArg) {
587 Info.FirstArg = TemplateArgument(QualType(Param, 0));
588 Info.SecondArg = TemplateArgument(Arg);
589 return Sema::TDK_NonDeducedMismatch;
590 }
591
592 // Perform template argument deduction for the template name.
593 if (Sema::TemplateDeductionResult Result
594 = DeduceTemplateArguments(S,
595 TemplateParams,
596 Param->getTemplateName(),
597 TemplateName(SpecArg->getSpecializedTemplate()),
598 Info, Deduced))
599 return Result;
600
601 // Perform template argument deduction for the template arguments.
602 return DeduceTemplateArguments(S, TemplateParams, Param->template_arguments(),
603 SpecArg->getTemplateArgs().asArray(), Info,
604 Deduced, /*NumberOfArgumentsMustMatch=*/true);
605}
606
607/// Determines whether the given type is an opaque type that
608/// might be more qualified when instantiated.
609static bool IsPossiblyOpaquelyQualifiedType(QualType T) {
610 switch (T->getTypeClass()) {
611 case Type::TypeOfExpr:
612 case Type::TypeOf:
613 case Type::DependentName:
614 case Type::Decltype:
615 case Type::UnresolvedUsing:
616 case Type::TemplateTypeParm:
617 return true;
618
619 case Type::ConstantArray:
620 case Type::IncompleteArray:
621 case Type::VariableArray:
622 case Type::DependentSizedArray:
623 return IsPossiblyOpaquelyQualifiedType(
624 cast<ArrayType>(T)->getElementType());
625
626 default:
627 return false;
628 }
629}
630
631/// Helper function to build a TemplateParameter when we don't
632/// know its type statically.
633static TemplateParameter makeTemplateParameter(Decl *D) {
634 if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(D))
635 return TemplateParameter(TTP);
636 if (NonTypeTemplateParmDecl *NTTP = dyn_cast<NonTypeTemplateParmDecl>(D))
637 return TemplateParameter(NTTP);
638
639 return TemplateParameter(cast<TemplateTemplateParmDecl>(D));
640}
641
642/// If \p Param is an expanded parameter pack, get the number of expansions.
643static Optional<unsigned> getExpandedPackSize(NamedDecl *Param) {
644 if (auto *NTTP = dyn_cast<NonTypeTemplateParmDecl>(Param))
645 if (NTTP->isExpandedParameterPack())
646 return NTTP->getNumExpansionTypes();
647
648 if (auto *TTP = dyn_cast<TemplateTemplateParmDecl>(Param))
649 if (TTP->isExpandedParameterPack())
650 return TTP->getNumExpansionTemplateParameters();
651
652 return None;
653}
654
655/// A pack that we're currently deducing.
656struct clang::DeducedPack {
657 // The index of the pack.
658 unsigned Index;
659
660 // The old value of the pack before we started deducing it.
661 DeducedTemplateArgument Saved;
662
663 // A deferred value of this pack from an inner deduction, that couldn't be
664 // deduced because this deduction hadn't happened yet.
665 DeducedTemplateArgument DeferredDeduction;
666
667 // The new value of the pack.
668 SmallVector<DeducedTemplateArgument, 4> New;
669
670 // The outer deduction for this pack, if any.
671 DeducedPack *Outer = nullptr;
672
673 DeducedPack(unsigned Index) : Index(Index) {}
674};
675
676namespace {
677
678/// A scope in which we're performing pack deduction.
679class PackDeductionScope {
680public:
681 /// Prepare to deduce the packs named within Pattern.
682 PackDeductionScope(Sema &S, TemplateParameterList *TemplateParams,
683 SmallVectorImpl<DeducedTemplateArgument> &Deduced,
684 TemplateDeductionInfo &Info, TemplateArgument Pattern)
685 : S(S), TemplateParams(TemplateParams), Deduced(Deduced), Info(Info) {
686 unsigned NumNamedPacks = addPacks(Pattern);
14
Calling 'PackDeductionScope::addPacks'
687 finishConstruction(NumNamedPacks);
688 }
689
690 /// Prepare to directly deduce arguments of the parameter with index \p Index.
691 PackDeductionScope(Sema &S, TemplateParameterList *TemplateParams,
692 SmallVectorImpl<DeducedTemplateArgument> &Deduced,
693 TemplateDeductionInfo &Info, unsigned Index)
694 : S(S), TemplateParams(TemplateParams), Deduced(Deduced), Info(Info) {
695 addPack(Index);
696 finishConstruction(1);
697 }
698
699private:
700 void addPack(unsigned Index) {
701 // Save the deduced template argument for the parameter pack expanded
702 // by this pack expansion, then clear out the deduction.
703 DeducedPack Pack(Index);
704 Pack.Saved = Deduced[Index];
705 Deduced[Index] = TemplateArgument();
706
707 // FIXME: What if we encounter multiple packs with different numbers of
708 // pre-expanded expansions? (This should already have been diagnosed
709 // during substitution.)
710 if (Optional<unsigned> ExpandedPackExpansions =
711 getExpandedPackSize(TemplateParams->getParam(Index)))
712 FixedNumExpansions = ExpandedPackExpansions;
713
714 Packs.push_back(Pack);
715 }
716
717 unsigned addPacks(TemplateArgument Pattern) {
718 // Compute the set of template parameter indices that correspond to
719 // parameter packs expanded by the pack expansion.
720 llvm::SmallBitVector SawIndices(TemplateParams->size());
15
Calling constructor for 'SmallBitVector'
19
Returning from constructor for 'SmallBitVector'
721
722 auto AddPack = [&](unsigned Index) {
723 if (SawIndices[Index])
724 return;
725 SawIndices[Index] = true;
726 addPack(Index);
727 };
728
729 // First look for unexpanded packs in the pattern.
730 SmallVector<UnexpandedParameterPack, 2> Unexpanded;
731 S.collectUnexpandedParameterPacks(Pattern, Unexpanded);
732 for (unsigned I = 0, N = Unexpanded.size(); I != N; ++I) {
20
Assuming 'I' is equal to 'N'
21
Loop condition is false. Execution continues on line 738
733 unsigned Depth, Index;
734 std::tie(Depth, Index) = getDepthAndIndex(Unexpanded[I]);
735 if (Depth == Info.getDeducedDepth())
736 AddPack(Index);
737 }
738 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-8~svn345461/tools/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 738, __PRETTY_FUNCTION__))
;
739
740 unsigned NumNamedPacks = Packs.size();
741
742 // We can also have deduced template parameters that do not actually
743 // appear in the pattern, but can be deduced by it (the type of a non-type
744 // template parameter pack, in particular). These won't have prevented us
745 // from partially expanding the pack.
746 llvm::SmallBitVector Used(TemplateParams->size());
747 MarkUsedTemplateParameters(S.Context, Pattern, /*OnlyDeduced*/true,
748 Info.getDeducedDepth(), Used);
749 for (int Index = Used.find_first(); Index != -1;
22
Assuming the condition is false
23
Loop condition is false. Execution continues on line 754
750 Index = Used.find_next(Index))
751 if (TemplateParams->getParam(Index)->isParameterPack())
752 AddPack(Index);
753
754 return NumNamedPacks;
755 }
24
Potential leak of memory pointed to by 'SawIndices.X'
756
757 void finishConstruction(unsigned NumNamedPacks) {
758 // Dig out the partially-substituted pack, if there is one.
759 const TemplateArgument *PartialPackArgs = nullptr;
760 unsigned NumPartialPackArgs = 0;
761 std::pair<unsigned, unsigned> PartialPackDepthIndex(-1u, -1u);
762 if (auto *Scope = S.CurrentInstantiationScope)
763 if (auto *Partial = Scope->getPartiallySubstitutedPack(
764 &PartialPackArgs, &NumPartialPackArgs))
765 PartialPackDepthIndex = getDepthAndIndex(Partial);
766
767 // This pack expansion will have been partially or fully expanded if
768 // it only names explicitly-specified parameter packs (including the
769 // partially-substituted one, if any).
770 bool IsExpanded = true;
771 for (unsigned I = 0; I != NumNamedPacks; ++I) {
772 if (Packs[I].Index >= Info.getNumExplicitArgs()) {
773 IsExpanded = false;
774 IsPartiallyExpanded = false;
775 break;
776 }
777 if (PartialPackDepthIndex ==
778 std::make_pair(Info.getDeducedDepth(), Packs[I].Index)) {
779 IsPartiallyExpanded = true;
780 }
781 }
782
783 // Skip over the pack elements that were expanded into separate arguments.
784 // If we partially expanded, this is the number of partial arguments.
785 if (IsPartiallyExpanded)
786 PackElements += NumPartialPackArgs;
787 else if (IsExpanded)
788 PackElements += *FixedNumExpansions;
789
790 for (auto &Pack : Packs) {
791 if (Info.PendingDeducedPacks.size() > Pack.Index)
792 Pack.Outer = Info.PendingDeducedPacks[Pack.Index];
793 else
794 Info.PendingDeducedPacks.resize(Pack.Index + 1);
795 Info.PendingDeducedPacks[Pack.Index] = &Pack;
796
797 if (PartialPackDepthIndex ==
798 std::make_pair(Info.getDeducedDepth(), Pack.Index)) {
799 Pack.New.append(PartialPackArgs, PartialPackArgs + NumPartialPackArgs);
800 // We pre-populate the deduced value of the partially-substituted
801 // pack with the specified value. This is not entirely correct: the
802 // value is supposed to have been substituted, not deduced, but the
803 // cases where this is observable require an exact type match anyway.
804 //
805 // FIXME: If we could represent a "depth i, index j, pack elem k"
806 // parameter, we could substitute the partially-substituted pack
807 // everywhere and avoid this.
808 if (!IsPartiallyExpanded)
809 Deduced[Pack.Index] = Pack.New[PackElements];
810 }
811 }
812 }
813
814public:
815 ~PackDeductionScope() {
816 for (auto &Pack : Packs)
817 Info.PendingDeducedPacks[Pack.Index] = Pack.Outer;
818 }
819
820 /// Determine whether this pack has already been partially expanded into a
821 /// sequence of (prior) function parameters / template arguments.
822 bool isPartiallyExpanded() { return IsPartiallyExpanded; }
823
824 /// Determine whether this pack expansion scope has a known, fixed arity.
825 /// This happens if it involves a pack from an outer template that has
826 /// (notionally) already been expanded.
827 bool hasFixedArity() { return FixedNumExpansions.hasValue(); }
828
829 /// Determine whether the next element of the argument is still part of this
830 /// pack. This is the case unless the pack is already expanded to a fixed
831 /// length.
832 bool hasNextElement() {
833 return !FixedNumExpansions || *FixedNumExpansions > PackElements;
834 }
835
836 /// Move to deducing the next element in each pack that is being deduced.
837 void nextPackElement() {
838 // Capture the deduced template arguments for each parameter pack expanded
839 // by this pack expansion, add them to the list of arguments we've deduced
840 // for that pack, then clear out the deduced argument.
841 for (auto &Pack : Packs) {
842 DeducedTemplateArgument &DeducedArg = Deduced[Pack.Index];
843 if (!Pack.New.empty() || !DeducedArg.isNull()) {
844 while (Pack.New.size() < PackElements)
845 Pack.New.push_back(DeducedTemplateArgument());
846 if (Pack.New.size() == PackElements)
847 Pack.New.push_back(DeducedArg);
848 else
849 Pack.New[PackElements] = DeducedArg;
850 DeducedArg = Pack.New.size() > PackElements + 1
851 ? Pack.New[PackElements + 1]
852 : DeducedTemplateArgument();
853 }
854 }
855 ++PackElements;
856 }
857
858 /// Finish template argument deduction for a set of argument packs,
859 /// producing the argument packs and checking for consistency with prior
860 /// deductions.
861 Sema::TemplateDeductionResult
862 finish(bool TreatNoDeductionsAsNonDeduced = true) {
863 // Build argument packs for each of the parameter packs expanded by this
864 // pack expansion.
865 for (auto &Pack : Packs) {
866 // Put back the old value for this pack.
867 Deduced[Pack.Index] = Pack.Saved;
868
869 // If we are deducing the size of this pack even if we didn't deduce any
870 // values for it, then make sure we build a pack of the right size.
871 // FIXME: Should we always deduce the size, even if the pack appears in
872 // a non-deduced context?
873 if (!TreatNoDeductionsAsNonDeduced)
874 Pack.New.resize(PackElements);
875
876 // Build or find a new value for this pack.
877 DeducedTemplateArgument NewPack;
878 if (PackElements && Pack.New.empty()) {
879 if (Pack.DeferredDeduction.isNull()) {
880 // We were not able to deduce anything for this parameter pack
881 // (because it only appeared in non-deduced contexts), so just
882 // restore the saved argument pack.
883 continue;
884 }
885
886 NewPack = Pack.DeferredDeduction;
887 Pack.DeferredDeduction = TemplateArgument();
888 } else if (Pack.New.empty()) {
889 // If we deduced an empty argument pack, create it now.
890 NewPack = DeducedTemplateArgument(TemplateArgument::getEmptyPack());
891 } else {
892 TemplateArgument *ArgumentPack =
893 new (S.Context) TemplateArgument[Pack.New.size()];
894 std::copy(Pack.New.begin(), Pack.New.end(), ArgumentPack);
895 NewPack = DeducedTemplateArgument(
896 TemplateArgument(llvm::makeArrayRef(ArgumentPack, Pack.New.size())),
897 // FIXME: This is wrong, it's possible that some pack elements are
898 // deduced from an array bound and others are not:
899 // template<typename ...T, T ...V> void g(const T (&...p)[V]);
900 // g({1, 2, 3}, {{}, {}});
901 // ... should deduce T = {int, size_t (from array bound)}.
902 Pack.New[0].wasDeducedFromArrayBound());
903 }
904
905 // Pick where we're going to put the merged pack.
906 DeducedTemplateArgument *Loc;
907 if (Pack.Outer) {
908 if (Pack.Outer->DeferredDeduction.isNull()) {
909 // Defer checking this pack until we have a complete pack to compare
910 // it against.
911 Pack.Outer->DeferredDeduction = NewPack;
912 continue;
913 }
914 Loc = &Pack.Outer->DeferredDeduction;
915 } else {
916 Loc = &Deduced[Pack.Index];
917 }
918
919 // Check the new pack matches any previous value.
920 DeducedTemplateArgument OldPack = *Loc;
921 DeducedTemplateArgument Result =
922 checkDeducedTemplateArguments(S.Context, OldPack, NewPack);
923
924 // If we deferred a deduction of this pack, check that one now too.
925 if (!Result.isNull() && !Pack.DeferredDeduction.isNull()) {
926 OldPack = Result;
927 NewPack = Pack.DeferredDeduction;
928 Result = checkDeducedTemplateArguments(S.Context, OldPack, NewPack);
929 }
930
931 NamedDecl *Param = TemplateParams->getParam(Pack.Index);
932 if (Result.isNull()) {
933 Info.Param = makeTemplateParameter(Param);
934 Info.FirstArg = OldPack;
935 Info.SecondArg = NewPack;
936 return Sema::TDK_Inconsistent;
937 }
938
939 // If we have a pre-expanded pack and we didn't deduce enough elements
940 // for it, fail deduction.
941 if (Optional<unsigned> Expansions = getExpandedPackSize(Param)) {
942 if (*Expansions != PackElements) {
943 Info.Param = makeTemplateParameter(Param);
944 Info.FirstArg = Result;
945 return Sema::TDK_IncompletePack;
946 }
947 }
948
949 *Loc = Result;
950 }
951
952 return Sema::TDK_Success;
953 }
954
955private:
956 Sema &S;
957 TemplateParameterList *TemplateParams;
958 SmallVectorImpl<DeducedTemplateArgument> &Deduced;
959 TemplateDeductionInfo &Info;
960 unsigned PackElements = 0;
961 bool IsPartiallyExpanded = false;
962 /// The number of expansions, if we have a fully-expanded pack in this scope.
963 Optional<unsigned> FixedNumExpansions;
964
965 SmallVector<DeducedPack, 2> Packs;
966};
967
968} // namespace
969
970/// Deduce the template arguments by comparing the list of parameter
971/// types to the list of argument types, as in the parameter-type-lists of
972/// function types (C++ [temp.deduct.type]p10).
973///
974/// \param S The semantic analysis object within which we are deducing
975///
976/// \param TemplateParams The template parameters that we are deducing
977///
978/// \param Params The list of parameter types
979///
980/// \param NumParams The number of types in \c Params
981///
982/// \param Args The list of argument types
983///
984/// \param NumArgs The number of types in \c Args
985///
986/// \param Info information about the template argument deduction itself
987///
988/// \param Deduced the deduced template arguments
989///
990/// \param TDF bitwise OR of the TemplateDeductionFlags bits that describe
991/// how template argument deduction is performed.
992///
993/// \param PartialOrdering If true, we are performing template argument
994/// deduction for during partial ordering for a call
995/// (C++0x [temp.deduct.partial]).
996///
997/// \returns the result of template argument deduction so far. Note that a
998/// "success" result means that template argument deduction has not yet failed,
999/// but it may still fail, later, for other reasons.
1000static Sema::TemplateDeductionResult
1001DeduceTemplateArguments(Sema &S,
1002 TemplateParameterList *TemplateParams,
1003 const QualType *Params, unsigned NumParams,
1004 const QualType *Args, unsigned NumArgs,
1005 TemplateDeductionInfo &Info,
1006 SmallVectorImpl<DeducedTemplateArgument> &Deduced,
1007 unsigned TDF,
1008 bool PartialOrdering = false) {
1009 // C++0x [temp.deduct.type]p10:
1010 // Similarly, if P has a form that contains (T), then each parameter type
1011 // Pi of the respective parameter-type- list of P is compared with the
1012 // corresponding parameter type Ai of the corresponding parameter-type-list
1013 // of A. [...]
1014 unsigned ArgIdx = 0, ParamIdx = 0;
1015 for (; ParamIdx != NumParams; ++ParamIdx) {
1016 // Check argument types.
1017 const PackExpansionType *Expansion
1018 = dyn_cast<PackExpansionType>(Params[ParamIdx]);
1019 if (!Expansion) {
1020 // Simple case: compare the parameter and argument types at this point.
1021
1022 // Make sure we have an argument.
1023 if (ArgIdx >= NumArgs)
1024 return Sema::TDK_MiscellaneousDeductionFailure;
1025
1026 if (isa<PackExpansionType>(Args[ArgIdx])) {
1027 // C++0x [temp.deduct.type]p22:
1028 // If the original function parameter associated with A is a function
1029 // parameter pack and the function parameter associated with P is not
1030 // a function parameter pack, then template argument deduction fails.
1031 return Sema::TDK_MiscellaneousDeductionFailure;
1032 }
1033
1034 if (Sema::TemplateDeductionResult Result
1035 = DeduceTemplateArgumentsByTypeMatch(S, TemplateParams,
1036 Params[ParamIdx], Args[ArgIdx],
1037 Info, Deduced, TDF,
1038 PartialOrdering))
1039 return Result;
1040
1041 ++ArgIdx;
1042 continue;
1043 }
1044
1045 // C++0x [temp.deduct.type]p10:
1046 // If the parameter-declaration corresponding to Pi is a function
1047 // parameter pack, then the type of its declarator- id is compared with
1048 // each remaining parameter type in the parameter-type-list of A. Each
1049 // comparison deduces template arguments for subsequent positions in the
1050 // template parameter packs expanded by the function parameter pack.
1051
1052 QualType Pattern = Expansion->getPattern();
1053 PackDeductionScope PackScope(S, TemplateParams, Deduced, Info, Pattern);
1054
1055 // A pack scope with fixed arity is not really a pack any more, so is not
1056 // a non-deduced context.
1057 if (ParamIdx + 1 == NumParams || PackScope.hasFixedArity()) {
1058 for (; ArgIdx < NumArgs && PackScope.hasNextElement(); ++ArgIdx) {
1059 // Deduce template arguments from the pattern.
1060 if (Sema::TemplateDeductionResult Result
1061 = DeduceTemplateArgumentsByTypeMatch(S, TemplateParams, Pattern,
1062 Args[ArgIdx], Info, Deduced,
1063 TDF, PartialOrdering))
1064 return Result;
1065
1066 PackScope.nextPackElement();
1067 }
1068 } else {
1069 // C++0x [temp.deduct.type]p5:
1070 // The non-deduced contexts are:
1071 // - A function parameter pack that does not occur at the end of the
1072 // parameter-declaration-clause.
1073 //
1074 // FIXME: There is no wording to say what we should do in this case. We
1075 // choose to resolve this by applying the same rule that is applied for a
1076 // function call: that is, deduce all contained packs to their
1077 // explicitly-specified values (or to <> if there is no such value).
1078 //
1079 // This is seemingly-arbitrarily different from the case of a template-id
1080 // with a non-trailing pack-expansion in its arguments, which renders the
1081 // entire template-argument-list a non-deduced context.
1082
1083 // If the parameter type contains an explicitly-specified pack that we
1084 // could not expand, skip the number of parameters notionally created
1085 // by the expansion.
1086 Optional<unsigned> NumExpansions = Expansion->getNumExpansions();
1087 if (NumExpansions && !PackScope.isPartiallyExpanded()) {
1088 for (unsigned I = 0; I != *NumExpansions && ArgIdx < NumArgs;
1089 ++I, ++ArgIdx)
1090 PackScope.nextPackElement();
1091 }
1092 }
1093
1094 // Build argument packs for each of the parameter packs expanded by this
1095 // pack expansion.
1096 if (auto Result = PackScope.finish())
1097 return Result;
1098 }
1099
1100 // Make sure we don't have any extra arguments.
1101 if (ArgIdx < NumArgs)
1102 return Sema::TDK_MiscellaneousDeductionFailure;
1103
1104 return Sema::TDK_Success;
1105}
1106
1107/// Determine whether the parameter has qualifiers that the argument
1108/// lacks. Put another way, determine whether there is no way to add
1109/// a deduced set of qualifiers to the ParamType that would result in
1110/// its qualifiers matching those of the ArgType.
1111static bool hasInconsistentOrSupersetQualifiersOf(QualType ParamType,
1112 QualType ArgType) {
1113 Qualifiers ParamQs = ParamType.getQualifiers();
1114 Qualifiers ArgQs = ArgType.getQualifiers();
1115
1116 if (ParamQs == ArgQs)
1117 return false;
1118
1119 // Mismatched (but not missing) Objective-C GC attributes.
1120 if (ParamQs.getObjCGCAttr() != ArgQs.getObjCGCAttr() &&
1121 ParamQs.hasObjCGCAttr())
1122 return true;
1123
1124 // Mismatched (but not missing) address spaces.
1125 if (ParamQs.getAddressSpace() != ArgQs.getAddressSpace() &&
1126 ParamQs.hasAddressSpace())
1127 return true;
1128
1129 // Mismatched (but not missing) Objective-C lifetime qualifiers.
1130 if (ParamQs.getObjCLifetime() != ArgQs.getObjCLifetime() &&
1131 ParamQs.hasObjCLifetime())
1132 return true;
1133
1134 // CVR qualifiers inconsistent or a superset.
1135 return (ParamQs.getCVRQualifiers() & ~ArgQs.getCVRQualifiers()) != 0;
1136}
1137
1138/// Compare types for equality with respect to possibly compatible
1139/// function types (noreturn adjustment, implicit calling conventions). If any
1140/// of parameter and argument is not a function, just perform type comparison.
1141///
1142/// \param Param the template parameter type.
1143///
1144/// \param Arg the argument type.
1145bool Sema::isSameOrCompatibleFunctionType(CanQualType Param,
1146 CanQualType Arg) {
1147 const FunctionType *ParamFunction = Param->getAs<FunctionType>(),
1148 *ArgFunction = Arg->getAs<FunctionType>();
1149
1150 // Just compare if not functions.
1151 if (!ParamFunction || !ArgFunction)
1152 return Param == Arg;
1153
1154 // Noreturn and noexcept adjustment.
1155 QualType AdjustedParam;
1156 if (IsFunctionConversion(Param, Arg, AdjustedParam))
1157 return Arg == Context.getCanonicalType(AdjustedParam);
1158
1159 // FIXME: Compatible calling conventions.
1160
1161 return Param == Arg;
1162}
1163
1164/// Get the index of the first template parameter that was originally from the
1165/// innermost template-parameter-list. This is 0 except when we concatenate
1166/// the template parameter lists of a class template and a constructor template
1167/// when forming an implicit deduction guide.
1168static unsigned getFirstInnerIndex(FunctionTemplateDecl *FTD) {
1169 auto *Guide = dyn_cast<CXXDeductionGuideDecl>(FTD->getTemplatedDecl());
1170 if (!Guide || !Guide->isImplicit())
1171 return 0;
1172 return Guide->getDeducedTemplate()->getTemplateParameters()->size();
1173}
1174
1175/// Determine whether a type denotes a forwarding reference.
1176static bool isForwardingReference(QualType Param, unsigned FirstInnerIndex) {
1177 // C++1z [temp.deduct.call]p3:
1178 // A forwarding reference is an rvalue reference to a cv-unqualified
1179 // template parameter that does not represent a template parameter of a
1180 // class template.
1181 if (auto *ParamRef = Param->getAs<RValueReferenceType>()) {
1182 if (ParamRef->getPointeeType().getQualifiers())
1183 return false;
1184 auto *TypeParm = ParamRef->getPointeeType()->getAs<TemplateTypeParmType>();
1185 return TypeParm && TypeParm->getIndex() >= FirstInnerIndex;
1186 }
1187 return false;
1188}
1189
1190/// Deduce the template arguments by comparing the parameter type and
1191/// the argument type (C++ [temp.deduct.type]).
1192///
1193/// \param S the semantic analysis object within which we are deducing
1194///
1195/// \param TemplateParams the template parameters that we are deducing
1196///
1197/// \param ParamIn the parameter type
1198///
1199/// \param ArgIn the argument type
1200///
1201/// \param Info information about the template argument deduction itself
1202///
1203/// \param Deduced the deduced template arguments
1204///
1205/// \param TDF bitwise OR of the TemplateDeductionFlags bits that describe
1206/// how template argument deduction is performed.
1207///
1208/// \param PartialOrdering Whether we're performing template argument deduction
1209/// in the context of partial ordering (C++0x [temp.deduct.partial]).
1210///
1211/// \returns the result of template argument deduction so far. Note that a
1212/// "success" result means that template argument deduction has not yet failed,
1213/// but it may still fail, later, for other reasons.
1214static Sema::TemplateDeductionResult
1215DeduceTemplateArgumentsByTypeMatch(Sema &S,
1216 TemplateParameterList *TemplateParams,
1217 QualType ParamIn, QualType ArgIn,
1218 TemplateDeductionInfo &Info,
1219 SmallVectorImpl<DeducedTemplateArgument> &Deduced,
1220 unsigned TDF,
1221 bool PartialOrdering,
1222 bool DeducedFromArrayBound) {
1223 // We only want to look at the canonical types, since typedefs and
1224 // sugar are not part of template argument deduction.
1225 QualType Param = S.Context.getCanonicalType(ParamIn);
1226 QualType Arg = S.Context.getCanonicalType(ArgIn);
1227
1228 // If the argument type is a pack expansion, look at its pattern.
1229 // This isn't explicitly called out
1230 if (const PackExpansionType *ArgExpansion
1231 = dyn_cast<PackExpansionType>(Arg))
1232 Arg = ArgExpansion->getPattern();
1233
1234 if (PartialOrdering) {
1235 // C++11 [temp.deduct.partial]p5:
1236 // Before the partial ordering is done, certain transformations are
1237 // performed on the types used for partial ordering:
1238 // - If P is a reference type, P is replaced by the type referred to.
1239 const ReferenceType *ParamRef = Param->getAs<ReferenceType>();
1240 if (ParamRef)
1241 Param = ParamRef->getPointeeType();
1242
1243 // - If A is a reference type, A is replaced by the type referred to.
1244 const ReferenceType *ArgRef = Arg->getAs<ReferenceType>();
1245 if (ArgRef)
1246 Arg = ArgRef->getPointeeType();
1247
1248 if (ParamRef && ArgRef && S.Context.hasSameUnqualifiedType(Param, Arg)) {
1249 // C++11 [temp.deduct.partial]p9:
1250 // If, for a given type, deduction succeeds in both directions (i.e.,
1251 // the types are identical after the transformations above) and both
1252 // P and A were reference types [...]:
1253 // - if [one type] was an lvalue reference and [the other type] was
1254 // not, [the other type] is not considered to be at least as
1255 // specialized as [the first type]
1256 // - if [one type] is more cv-qualified than [the other type],
1257 // [the other type] is not considered to be at least as specialized
1258 // as [the first type]
1259 // Objective-C ARC adds:
1260 // - [one type] has non-trivial lifetime, [the other type] has
1261 // __unsafe_unretained lifetime, and the types are otherwise
1262 // identical
1263 //
1264 // A is "considered to be at least as specialized" as P iff deduction
1265 // succeeds, so we model this as a deduction failure. Note that
1266 // [the first type] is P and [the other type] is A here; the standard
1267 // gets this backwards.
1268 Qualifiers ParamQuals = Param.getQualifiers();
1269 Qualifiers ArgQuals = Arg.getQualifiers();
1270 if ((ParamRef->isLValueReferenceType() &&
1271 !ArgRef->isLValueReferenceType()) ||
1272 ParamQuals.isStrictSupersetOf(ArgQuals) ||
1273 (ParamQuals.hasNonTrivialObjCLifetime() &&
1274 ArgQuals.getObjCLifetime() == Qualifiers::OCL_ExplicitNone &&
1275 ParamQuals.withoutObjCLifetime() ==
1276 ArgQuals.withoutObjCLifetime())) {
1277 Info.FirstArg = TemplateArgument(ParamIn);
1278 Info.SecondArg = TemplateArgument(ArgIn);
1279 return Sema::TDK_NonDeducedMismatch;
1280 }
1281 }
1282
1283 // C++11 [temp.deduct.partial]p7:
1284 // Remove any top-level cv-qualifiers:
1285 // - If P is a cv-qualified type, P is replaced by the cv-unqualified
1286 // version of P.
1287 Param = Param.getUnqualifiedType();
1288 // - If A is a cv-qualified type, A is replaced by the cv-unqualified
1289 // version of A.
1290 Arg = Arg.getUnqualifiedType();
1291 } else {
1292 // C++0x [temp.deduct.call]p4 bullet 1:
1293 // - If the original P is a reference type, the deduced A (i.e., the type
1294 // referred to by the reference) can be more cv-qualified than the
1295 // transformed A.
1296 if (TDF & TDF_ParamWithReferenceType) {
1297 Qualifiers Quals;
1298 QualType UnqualParam = S.Context.getUnqualifiedArrayType(Param, Quals);
1299 Quals.setCVRQualifiers(Quals.getCVRQualifiers() &
1300 Arg.getCVRQualifiers());
1301 Param = S.Context.getQualifiedType(UnqualParam, Quals);
1302 }
1303
1304 if ((TDF & TDF_TopLevelParameterTypeList) && !Param->isFunctionType()) {
1305 // C++0x [temp.deduct.type]p10:
1306 // If P and A are function types that originated from deduction when
1307 // taking the address of a function template (14.8.2.2) or when deducing
1308 // template arguments from a function declaration (14.8.2.6) and Pi and
1309 // Ai are parameters of the top-level parameter-type-list of P and A,
1310 // respectively, Pi is adjusted if it is a forwarding reference and Ai
1311 // is an lvalue reference, in
1312 // which case the type of Pi is changed to be the template parameter
1313 // type (i.e., T&& is changed to simply T). [ Note: As a result, when
1314 // Pi is T&& and Ai is X&, the adjusted Pi will be T, causing T to be
1315 // deduced as X&. - end note ]
1316 TDF &= ~TDF_TopLevelParameterTypeList;
1317 if (isForwardingReference(Param, 0) && Arg->isLValueReferenceType())
1318 Param = Param->getPointeeType();
1319 }
1320 }
1321
1322 // C++ [temp.deduct.type]p9:
1323 // A template type argument T, a template template argument TT or a
1324 // template non-type argument i can be deduced if P and A have one of
1325 // the following forms:
1326 //
1327 // T
1328 // cv-list T
1329 if (const TemplateTypeParmType *TemplateTypeParm
1330 = Param->getAs<TemplateTypeParmType>()) {
1331 // Just skip any attempts to deduce from a placeholder type or a parameter
1332 // at a different depth.
1333 if (Arg->isPlaceholderType() ||
1334 Info.getDeducedDepth() != TemplateTypeParm->getDepth())
1335 return Sema::TDK_Success;
1336
1337 unsigned Index = TemplateTypeParm->getIndex();
1338 bool RecanonicalizeArg = false;
1339
1340 // If the argument type is an array type, move the qualifiers up to the
1341 // top level, so they can be matched with the qualifiers on the parameter.
1342 if (isa<ArrayType>(Arg)) {
1343 Qualifiers Quals;
1344 Arg = S.Context.getUnqualifiedArrayType(Arg, Quals);
1345 if (Quals) {
1346 Arg = S.Context.getQualifiedType(Arg, Quals);
1347 RecanonicalizeArg = true;
1348 }
1349 }
1350
1351 // The argument type can not be less qualified than the parameter
1352 // type.
1353 if (!(TDF & TDF_IgnoreQualifiers) &&
1354 hasInconsistentOrSupersetQualifiersOf(Param, Arg)) {
1355 Info.Param = cast<TemplateTypeParmDecl>(TemplateParams->getParam(Index));
1356 Info.FirstArg = TemplateArgument(Param);
1357 Info.SecondArg = TemplateArgument(Arg);
1358 return Sema::TDK_Underqualified;
1359 }
1360
1361 // Do not match a function type with a cv-qualified type.
1362 // http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#1584
1363 if (Arg->isFunctionType() && Param.hasQualifiers()) {
1364 return Sema::TDK_NonDeducedMismatch;
1365 }
1366
1367 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-8~svn345461/tools/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 1368, __PRETTY_FUNCTION__))
1368 "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-8~svn345461/tools/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 1368, __PRETTY_FUNCTION__))
;
1369 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-8~svn345461/tools/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 1369, __PRETTY_FUNCTION__))
;
1370 QualType DeducedType = Arg;
1371
1372 // Remove any qualifiers on the parameter from the deduced type.
1373 // We checked the qualifiers for consistency above.
1374 Qualifiers DeducedQs = DeducedType.getQualifiers();
1375 Qualifiers ParamQs = Param.getQualifiers();
1376 DeducedQs.removeCVRQualifiers(ParamQs.getCVRQualifiers());
1377 if (ParamQs.hasObjCGCAttr())
1378 DeducedQs.removeObjCGCAttr();
1379 if (ParamQs.hasAddressSpace())
1380 DeducedQs.removeAddressSpace();
1381 if (ParamQs.hasObjCLifetime())
1382 DeducedQs.removeObjCLifetime();
1383
1384 // Objective-C ARC:
1385 // If template deduction would produce a lifetime qualifier on a type
1386 // that is not a lifetime type, template argument deduction fails.
1387 if (ParamQs.hasObjCLifetime() && !DeducedType->isObjCLifetimeType() &&
1388 !DeducedType->isDependentType()) {
1389 Info.Param = cast<TemplateTypeParmDecl>(TemplateParams->getParam(Index));
1390 Info.FirstArg = TemplateArgument(Param);
1391 Info.SecondArg = TemplateArgument(Arg);
1392 return Sema::TDK_Underqualified;
1393 }
1394
1395 // Objective-C ARC:
1396 // If template deduction would produce an argument type with lifetime type
1397 // but no lifetime qualifier, the __strong lifetime qualifier is inferred.
1398 if (S.getLangOpts().ObjCAutoRefCount &&
1399 DeducedType->isObjCLifetimeType() &&
1400 !DeducedQs.hasObjCLifetime())
1401 DeducedQs.setObjCLifetime(Qualifiers::OCL_Strong);
1402
1403 DeducedType = S.Context.getQualifiedType(DeducedType.getUnqualifiedType(),
1404 DeducedQs);
1405
1406 if (RecanonicalizeArg)
1407 DeducedType = S.Context.getCanonicalType(DeducedType);
1408
1409 DeducedTemplateArgument NewDeduced(DeducedType, DeducedFromArrayBound);
1410 DeducedTemplateArgument Result = checkDeducedTemplateArguments(S.Context,
1411 Deduced[Index],
1412 NewDeduced);
1413 if (Result.isNull()) {
1414 Info.Param = cast<TemplateTypeParmDecl>(TemplateParams->getParam(Index));
1415 Info.FirstArg = Deduced[Index];
1416 Info.SecondArg = NewDeduced;
1417 return Sema::TDK_Inconsistent;
1418 }
1419
1420 Deduced[Index] = Result;
1421 return Sema::TDK_Success;
1422 }
1423
1424 // Set up the template argument deduction information for a failure.
1425 Info.FirstArg = TemplateArgument(ParamIn);
1426 Info.SecondArg = TemplateArgument(ArgIn);
1427
1428 // If the parameter is an already-substituted template parameter
1429 // pack, do nothing: we don't know which of its arguments to look
1430 // at, so we have to wait until all of the parameter packs in this
1431 // expansion have arguments.
1432 if (isa<SubstTemplateTypeParmPackType>(Param))
1433 return Sema::TDK_Success;
1434
1435 // Check the cv-qualifiers on the parameter and argument types.
1436 CanQualType CanParam = S.Context.getCanonicalType(Param);
1437 CanQualType CanArg = S.Context.getCanonicalType(Arg);
1438 if (!(TDF & TDF_IgnoreQualifiers)) {
1439 if (TDF & TDF_ParamWithReferenceType) {
1440 if (hasInconsistentOrSupersetQualifiersOf(Param, Arg))
1441 return Sema::TDK_NonDeducedMismatch;
1442 } else if (TDF & TDF_ArgWithReferenceType) {
1443 // C++ [temp.deduct.conv]p4:
1444 // If the original A is a reference type, A can be more cv-qualified
1445 // than the deduced A
1446 if (!Arg.getQualifiers().compatiblyIncludes(Param.getQualifiers()))
1447 return Sema::TDK_NonDeducedMismatch;
1448
1449 // Strip out all extra qualifiers from the argument to figure out the
1450 // type we're converting to, prior to the qualification conversion.
1451 Qualifiers Quals;
1452 Arg = S.Context.getUnqualifiedArrayType(Arg, Quals);
1453 Arg = S.Context.getQualifiedType(Arg, Param.getQualifiers());
1454 } else if (!IsPossiblyOpaquelyQualifiedType(Param)) {
1455 if (Param.getCVRQualifiers() != Arg.getCVRQualifiers())
1456 return Sema::TDK_NonDeducedMismatch;
1457 }
1458
1459 // If the parameter type is not dependent, there is nothing to deduce.
1460 if (!Param->isDependentType()) {
1461 if (!(TDF & TDF_SkipNonDependent)) {
1462 bool NonDeduced =
1463 (TDF & TDF_AllowCompatibleFunctionType)
1464 ? !S.isSameOrCompatibleFunctionType(CanParam, CanArg)
1465 : Param != Arg;
1466 if (NonDeduced) {
1467 return Sema::TDK_NonDeducedMismatch;
1468 }
1469 }
1470 return Sema::TDK_Success;
1471 }
1472 } else if (!Param->isDependentType()) {
1473 CanQualType ParamUnqualType = CanParam.getUnqualifiedType(),
1474 ArgUnqualType = CanArg.getUnqualifiedType();
1475 bool Success =
1476 (TDF & TDF_AllowCompatibleFunctionType)
1477 ? S.isSameOrCompatibleFunctionType(ParamUnqualType, ArgUnqualType)
1478 : ParamUnqualType == ArgUnqualType;
1479 if (Success)
1480 return Sema::TDK_Success;
1481 }
1482
1483 switch (Param->getTypeClass()) {
1484 // Non-canonical types cannot appear here.
1485#define NON_CANONICAL_TYPE(Class, Base) \
1486 case Type::Class: llvm_unreachable("deducing non-canonical type: " #Class)::llvm::llvm_unreachable_internal("deducing non-canonical type: "
#Class, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 1486)
;
1487#define TYPE(Class, Base)
1488#include "clang/AST/TypeNodes.def"
1489
1490 case Type::TemplateTypeParm:
1491 case Type::SubstTemplateTypeParmPack:
1492 llvm_unreachable("Type nodes handled above")::llvm::llvm_unreachable_internal("Type nodes handled above",
"/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 1492)
;
1493
1494 // These types cannot be dependent, so simply check whether the types are
1495 // the same.
1496 case Type::Builtin:
1497 case Type::VariableArray:
1498 case Type::Vector:
1499 case Type::FunctionNoProto:
1500 case Type::Record:
1501 case Type::Enum:
1502 case Type::ObjCObject:
1503 case Type::ObjCInterface:
1504 case Type::ObjCObjectPointer:
1505 if (TDF & TDF_SkipNonDependent)
1506 return Sema::TDK_Success;
1507
1508 if (TDF & TDF_IgnoreQualifiers) {
1509 Param = Param.getUnqualifiedType();
1510 Arg = Arg.getUnqualifiedType();
1511 }
1512
1513 return Param == Arg? Sema::TDK_Success : Sema::TDK_NonDeducedMismatch;
1514
1515 // _Complex T [placeholder extension]
1516 case Type::Complex:
1517 if (const ComplexType *ComplexArg = Arg->getAs<ComplexType>())
1518 return DeduceTemplateArgumentsByTypeMatch(S, TemplateParams,
1519 cast<ComplexType>(Param)->getElementType(),
1520 ComplexArg->getElementType(),
1521 Info, Deduced, TDF);
1522
1523 return Sema::TDK_NonDeducedMismatch;
1524
1525 // _Atomic T [extension]
1526 case Type::Atomic:
1527 if (const AtomicType *AtomicArg = Arg->getAs<AtomicType>())
1528 return DeduceTemplateArgumentsByTypeMatch(S, TemplateParams,
1529 cast<AtomicType>(Param)->getValueType(),
1530 AtomicArg->getValueType(),
1531 Info, Deduced, TDF);
1532
1533 return Sema::TDK_NonDeducedMismatch;
1534
1535 // T *
1536 case Type::Pointer: {
1537 QualType PointeeType;
1538 if (const PointerType *PointerArg = Arg->getAs<PointerType>()) {
1539 PointeeType = PointerArg->getPointeeType();
1540 } else if (const ObjCObjectPointerType *PointerArg
1541 = Arg->getAs<ObjCObjectPointerType>()) {
1542 PointeeType = PointerArg->getPointeeType();
1543 } else {
1544 return Sema::TDK_NonDeducedMismatch;
1545 }
1546
1547 unsigned SubTDF = TDF & (TDF_IgnoreQualifiers | TDF_DerivedClass);
1548 return DeduceTemplateArgumentsByTypeMatch(S, TemplateParams,
1549 cast<PointerType>(Param)->getPointeeType(),
1550 PointeeType,
1551 Info, Deduced, SubTDF);
1552 }
1553
1554 // T &
1555 case Type::LValueReference: {
1556 const LValueReferenceType *ReferenceArg =
1557 Arg->getAs<LValueReferenceType>();
1558 if (!ReferenceArg)
1559 return Sema::TDK_NonDeducedMismatch;
1560
1561 return DeduceTemplateArgumentsByTypeMatch(S, TemplateParams,
1562 cast<LValueReferenceType>(Param)->getPointeeType(),
1563 ReferenceArg->getPointeeType(), Info, Deduced, 0);
1564 }
1565
1566 // T && [C++0x]
1567 case Type::RValueReference: {
1568 const RValueReferenceType *ReferenceArg =
1569 Arg->getAs<RValueReferenceType>();
1570 if (!ReferenceArg)
1571 return Sema::TDK_NonDeducedMismatch;
1572
1573 return DeduceTemplateArgumentsByTypeMatch(S, TemplateParams,
1574 cast<RValueReferenceType>(Param)->getPointeeType(),
1575 ReferenceArg->getPointeeType(),
1576 Info, Deduced, 0);
1577 }
1578
1579 // T [] (implied, but not stated explicitly)
1580 case Type::IncompleteArray: {
1581 const IncompleteArrayType *IncompleteArrayArg =
1582 S.Context.getAsIncompleteArrayType(Arg);
1583 if (!IncompleteArrayArg)
1584 return Sema::TDK_NonDeducedMismatch;
1585
1586 unsigned SubTDF = TDF & TDF_IgnoreQualifiers;
1587 return DeduceTemplateArgumentsByTypeMatch(S, TemplateParams,
1588 S.Context.getAsIncompleteArrayType(Param)->getElementType(),
1589 IncompleteArrayArg->getElementType(),
1590 Info, Deduced, SubTDF);
1591 }
1592
1593 // T [integer-constant]
1594 case Type::ConstantArray: {
1595 const ConstantArrayType *ConstantArrayArg =
1596 S.Context.getAsConstantArrayType(Arg);
1597 if (!ConstantArrayArg)
1598 return Sema::TDK_NonDeducedMismatch;
1599
1600 const ConstantArrayType *ConstantArrayParm =
1601 S.Context.getAsConstantArrayType(Param);
1602 if (ConstantArrayArg->getSize() != ConstantArrayParm->getSize())
1603 return Sema::TDK_NonDeducedMismatch;
1604
1605 unsigned SubTDF = TDF & TDF_IgnoreQualifiers;
1606 return DeduceTemplateArgumentsByTypeMatch(S, TemplateParams,
1607 ConstantArrayParm->getElementType(),
1608 ConstantArrayArg->getElementType(),
1609 Info, Deduced, SubTDF);
1610 }
1611
1612 // type [i]
1613 case Type::DependentSizedArray: {
1614 const ArrayType *ArrayArg = S.Context.getAsArrayType(Arg);
1615 if (!ArrayArg)
1616 return Sema::TDK_NonDeducedMismatch;
1617
1618 unsigned SubTDF = TDF & TDF_IgnoreQualifiers;
1619
1620 // Check the element type of the arrays
1621 const DependentSizedArrayType *DependentArrayParm
1622 = S.Context.getAsDependentSizedArrayType(Param);
1623 if (Sema::TemplateDeductionResult Result
1624 = DeduceTemplateArgumentsByTypeMatch(S, TemplateParams,
1625 DependentArrayParm->getElementType(),
1626 ArrayArg->getElementType(),
1627 Info, Deduced, SubTDF))
1628 return Result;
1629
1630 // Determine the array bound is something we can deduce.
1631 NonTypeTemplateParmDecl *NTTP
1632 = getDeducedParameterFromExpr(Info, DependentArrayParm->getSizeExpr());
1633 if (!NTTP)
1634 return Sema::TDK_Success;
1635
1636 // We can perform template argument deduction for the given non-type
1637 // template parameter.
1638 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-8~svn345461/tools/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 1639, __PRETTY_FUNCTION__))
1639 "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-8~svn345461/tools/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 1639, __PRETTY_FUNCTION__))
;
1640 if (const ConstantArrayType *ConstantArrayArg
1641 = dyn_cast<ConstantArrayType>(ArrayArg)) {
1642 llvm::APSInt Size(ConstantArrayArg->getSize());
1643 return DeduceNonTypeTemplateArgument(S, TemplateParams, NTTP, Size,
1644 S.Context.getSizeType(),
1645 /*ArrayBound=*/true,
1646 Info, Deduced);
1647 }
1648 if (const DependentSizedArrayType *DependentArrayArg
1649 = dyn_cast<DependentSizedArrayType>(ArrayArg))
1650 if (DependentArrayArg->getSizeExpr())
1651 return DeduceNonTypeTemplateArgument(S, TemplateParams, NTTP,
1652 DependentArrayArg->getSizeExpr(),
1653 Info, Deduced);
1654
1655 // Incomplete type does not match a dependently-sized array type
1656 return Sema::TDK_NonDeducedMismatch;
1657 }
1658
1659 // type(*)(T)
1660 // T(*)()
1661 // T(*)(T)
1662 case Type::FunctionProto: {
1663 unsigned SubTDF = TDF & TDF_TopLevelParameterTypeList;
1664 const FunctionProtoType *FunctionProtoArg =
1665 dyn_cast<FunctionProtoType>(Arg);
1666 if (!FunctionProtoArg)
1667 return Sema::TDK_NonDeducedMismatch;
1668
1669 const FunctionProtoType *FunctionProtoParam =
1670 cast<FunctionProtoType>(Param);
1671
1672 if (FunctionProtoParam->getTypeQuals()
1673 != FunctionProtoArg->getTypeQuals() ||
1674 FunctionProtoParam->getRefQualifier()
1675 != FunctionProtoArg->getRefQualifier() ||
1676 FunctionProtoParam->isVariadic() != FunctionProtoArg->isVariadic())
1677 return Sema::TDK_NonDeducedMismatch;
1678
1679 // Check return types.
1680 if (auto Result = DeduceTemplateArgumentsByTypeMatch(
1681 S, TemplateParams, FunctionProtoParam->getReturnType(),
1682 FunctionProtoArg->getReturnType(), Info, Deduced, 0))
1683 return Result;
1684
1685 // Check parameter types.
1686 if (auto Result = DeduceTemplateArguments(
1687 S, TemplateParams, FunctionProtoParam->param_type_begin(),
1688 FunctionProtoParam->getNumParams(),
1689 FunctionProtoArg->param_type_begin(),
1690 FunctionProtoArg->getNumParams(), Info, Deduced, SubTDF))
1691 return Result;
1692
1693 if (TDF & TDF_AllowCompatibleFunctionType)
1694 return Sema::TDK_Success;
1695
1696 // FIXME: Per core-2016/10/1019 (no corresponding core issue yet), permit
1697 // deducing through the noexcept-specifier if it's part of the canonical
1698 // type. libstdc++ relies on this.
1699 Expr *NoexceptExpr = FunctionProtoParam->getNoexceptExpr();
1700 if (NonTypeTemplateParmDecl *NTTP =
1701 NoexceptExpr ? getDeducedParameterFromExpr(Info, NoexceptExpr)
1702 : nullptr) {
1703 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-8~svn345461/tools/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 1704, __PRETTY_FUNCTION__))
1704 "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-8~svn345461/tools/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 1704, __PRETTY_FUNCTION__))
;
1705
1706 llvm::APSInt Noexcept(1);
1707 switch (FunctionProtoArg->canThrow()) {
1708 case CT_Cannot:
1709 Noexcept = 1;
1710 LLVM_FALLTHROUGH[[clang::fallthrough]];
1711
1712 case CT_Can:
1713 // We give E in noexcept(E) the "deduced from array bound" treatment.
1714 // FIXME: Should we?
1715 return DeduceNonTypeTemplateArgument(
1716 S, TemplateParams, NTTP, Noexcept, S.Context.BoolTy,
1717 /*ArrayBound*/true, Info, Deduced);
1718
1719 case CT_Dependent:
1720 if (Expr *ArgNoexceptExpr = FunctionProtoArg->getNoexceptExpr())
1721 return DeduceNonTypeTemplateArgument(
1722 S, TemplateParams, NTTP, ArgNoexceptExpr, Info, Deduced);
1723 // Can't deduce anything from throw(T...).
1724 break;
1725 }
1726 }
1727 // FIXME: Detect non-deduced exception specification mismatches?
1728 //
1729 // Careful about [temp.deduct.call] and [temp.deduct.conv], which allow
1730 // top-level differences in noexcept-specifications.
1731
1732 return Sema::TDK_Success;
1733 }
1734
1735 case Type::InjectedClassName:
1736 // Treat a template's injected-class-name as if the template
1737 // specialization type had been used.
1738 Param = cast<InjectedClassNameType>(Param)
1739 ->getInjectedSpecializationType();
1740 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-8~svn345461/tools/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 1741, __PRETTY_FUNCTION__))
1741 "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-8~svn345461/tools/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 1741, __PRETTY_FUNCTION__))
;
1742 LLVM_FALLTHROUGH[[clang::fallthrough]];
1743
1744 // template-name<T> (where template-name refers to a class template)
1745 // template-name<i>
1746 // TT<T>
1747 // TT<i>
1748 // TT<>
1749 case Type::TemplateSpecialization: {
1750 const TemplateSpecializationType *SpecParam =
1751 cast<TemplateSpecializationType>(Param);
1752
1753 // When Arg cannot be a derived class, we can just try to deduce template
1754 // arguments from the template-id.
1755 const RecordType *RecordT = Arg->getAs<RecordType>();
1756 if (!(TDF & TDF_DerivedClass) || !RecordT)
1757 return DeduceTemplateArguments(S, TemplateParams, SpecParam, Arg, Info,
1758 Deduced);
1759
1760 SmallVector<DeducedTemplateArgument, 8> DeducedOrig(Deduced.begin(),
1761 Deduced.end());
1762
1763 Sema::TemplateDeductionResult Result = DeduceTemplateArguments(
1764 S, TemplateParams, SpecParam, Arg, Info, Deduced);
1765
1766 if (Result == Sema::TDK_Success)
1767 return Result;
1768
1769 // We cannot inspect base classes as part of deduction when the type
1770 // is incomplete, so either instantiate any templates necessary to
1771 // complete the type, or skip over it if it cannot be completed.
1772 if (!S.isCompleteType(Info.getLocation(), Arg))
1773 return Result;
1774
1775 // C++14 [temp.deduct.call] p4b3:
1776 // If P is a class and P has the form simple-template-id, then the
1777 // transformed A can be a derived class of the deduced A. Likewise if
1778 // P is a pointer to a class of the form simple-template-id, the
1779 // transformed A can be a pointer to a derived class pointed to by the
1780 // deduced A.
1781 //
1782 // These alternatives are considered only if type deduction would
1783 // otherwise fail. If they yield more than one possible deduced A, the
1784 // type deduction fails.
1785
1786 // Reset the incorrectly deduced argument from above.
1787 Deduced = DeducedOrig;
1788
1789 // Use data recursion to crawl through the list of base classes.
1790 // Visited contains the set of nodes we have already visited, while
1791 // ToVisit is our stack of records that we still need to visit.
1792 llvm::SmallPtrSet<const RecordType *, 8> Visited;
1793 SmallVector<const RecordType *, 8> ToVisit;
1794 ToVisit.push_back(RecordT);
1795 bool Successful = false;
1796 SmallVector<DeducedTemplateArgument, 8> SuccessfulDeduced;
1797 while (!ToVisit.empty()) {
1798 // Retrieve the next class in the inheritance hierarchy.
1799 const RecordType *NextT = ToVisit.pop_back_val();
1800
1801 // If we have already seen this type, skip it.
1802 if (!Visited.insert(NextT).second)
1803 continue;
1804
1805 // If this is a base class, try to perform template argument
1806 // deduction from it.
1807 if (NextT != RecordT) {
1808 TemplateDeductionInfo BaseInfo(Info.getLocation());
1809 Sema::TemplateDeductionResult BaseResult =
1810 DeduceTemplateArguments(S, TemplateParams, SpecParam,
1811 QualType(NextT, 0), BaseInfo, Deduced);
1812
1813 // If template argument deduction for this base was successful,
1814 // note that we had some success. Otherwise, ignore any deductions
1815 // from this base class.
1816 if (BaseResult == Sema::TDK_Success) {
1817 // If we've already seen some success, then deduction fails due to
1818 // an ambiguity (temp.deduct.call p5).
1819 if (Successful)
1820 return Sema::TDK_MiscellaneousDeductionFailure;
1821
1822 Successful = true;
1823 std::swap(SuccessfulDeduced, Deduced);
1824
1825 Info.Param = BaseInfo.Param;
1826 Info.FirstArg = BaseInfo.FirstArg;
1827 Info.SecondArg = BaseInfo.SecondArg;
1828 }
1829
1830 Deduced = DeducedOrig;
1831 }
1832
1833 // Visit base classes
1834 CXXRecordDecl *Next = cast<CXXRecordDecl>(NextT->getDecl());
1835 for (const auto &Base : Next->bases()) {
1836 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-8~svn345461/tools/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 1837, __PRETTY_FUNCTION__))
1837 "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-8~svn345461/tools/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 1837, __PRETTY_FUNCTION__))
;
1838 ToVisit.push_back(Base.getType()->getAs<RecordType>());
1839 }
1840 }
1841
1842 if (Successful) {
1843 std::swap(SuccessfulDeduced, Deduced);
1844 return Sema::TDK_Success;
1845 }
1846
1847 return Result;
1848 }
1849
1850 // T type::*
1851 // T T::*
1852 // T (type::*)()
1853 // type (T::*)()
1854 // type (type::*)(T)
1855 // type (T::*)(T)
1856 // T (type::*)(T)
1857 // T (T::*)()
1858 // T (T::*)(T)
1859 case Type::MemberPointer: {
1860 const MemberPointerType *MemPtrParam = cast<MemberPointerType>(Param);
1861 const MemberPointerType *MemPtrArg = dyn_cast<MemberPointerType>(Arg);
1862 if (!MemPtrArg)
1863 return Sema::TDK_NonDeducedMismatch;
1864
1865 QualType ParamPointeeType = MemPtrParam->getPointeeType();
1866 if (ParamPointeeType->isFunctionType())
1867 S.adjustMemberFunctionCC(ParamPointeeType, /*IsStatic=*/true,
1868 /*IsCtorOrDtor=*/false, Info.getLocation());
1869 QualType ArgPointeeType = MemPtrArg->getPointeeType();
1870 if (ArgPointeeType->isFunctionType())
1871 S.adjustMemberFunctionCC(ArgPointeeType, /*IsStatic=*/true,
1872 /*IsCtorOrDtor=*/false, Info.getLocation());
1873
1874 if (Sema::TemplateDeductionResult Result
1875 = DeduceTemplateArgumentsByTypeMatch(S, TemplateParams,
1876 ParamPointeeType,
1877 ArgPointeeType,
1878 Info, Deduced,
1879 TDF & TDF_IgnoreQualifiers))
1880 return Result;
1881
1882 return DeduceTemplateArgumentsByTypeMatch(S, TemplateParams,
1883 QualType(MemPtrParam->getClass(), 0),
1884 QualType(MemPtrArg->getClass(), 0),
1885 Info, Deduced,
1886 TDF & TDF_IgnoreQualifiers);
1887 }
1888
1889 // (clang extension)
1890 //
1891 // type(^)(T)
1892 // T(^)()
1893 // T(^)(T)
1894 case Type::BlockPointer: {
1895 const BlockPointerType *BlockPtrParam = cast<BlockPointerType>(Param);
1896 const BlockPointerType *BlockPtrArg = dyn_cast<BlockPointerType>(Arg);
1897
1898 if (!BlockPtrArg)
1899 return Sema::TDK_NonDeducedMismatch;
1900
1901 return DeduceTemplateArgumentsByTypeMatch(S, TemplateParams,
1902 BlockPtrParam->getPointeeType(),
1903 BlockPtrArg->getPointeeType(),
1904 Info, Deduced, 0);
1905 }
1906
1907 // (clang extension)
1908 //
1909 // T __attribute__(((ext_vector_type(<integral constant>))))
1910 case Type::ExtVector: {
1911 const ExtVectorType *VectorParam = cast<ExtVectorType>(Param);
1912 if (const ExtVectorType *VectorArg = dyn_cast<ExtVectorType>(Arg)) {
1913 // Make sure that the vectors have the same number of elements.
1914 if (VectorParam->getNumElements() != VectorArg->getNumElements())
1915 return Sema::TDK_NonDeducedMismatch;
1916
1917 // Perform deduction on the element types.
1918 return DeduceTemplateArgumentsByTypeMatch(S, TemplateParams,
1919 VectorParam->getElementType(),
1920 VectorArg->getElementType(),
1921 Info, Deduced, TDF);
1922 }
1923
1924 if (const DependentSizedExtVectorType *VectorArg
1925 = dyn_cast<DependentSizedExtVectorType>(Arg)) {
1926 // We can't check the number of elements, since the argument has a
1927 // dependent number of elements. This can only occur during partial
1928 // ordering.
1929
1930 // Perform deduction on the element types.
1931 return DeduceTemplateArgumentsByTypeMatch(S, TemplateParams,
1932 VectorParam->getElementType(),
1933 VectorArg->getElementType(),
1934 Info, Deduced, TDF);
1935 }
1936
1937 return Sema::TDK_NonDeducedMismatch;
1938 }
1939
1940 case Type::DependentVector: {
1941 const auto *VectorParam = cast<DependentVectorType>(Param);
1942
1943 if (const auto *VectorArg = dyn_cast<VectorType>(Arg)) {
1944 // Perform deduction on the element types.
1945 if (Sema::TemplateDeductionResult Result =
1946 DeduceTemplateArgumentsByTypeMatch(
1947 S, TemplateParams, VectorParam->getElementType(),
1948 VectorArg->getElementType(), Info, Deduced, TDF))
1949 return Result;
1950
1951 // Perform deduction on the vector size, if we can.
1952 NonTypeTemplateParmDecl *NTTP =
1953 getDeducedParameterFromExpr(Info, VectorParam->getSizeExpr());
1954 if (!NTTP)
1955 return Sema::TDK_Success;
1956
1957 llvm::APSInt ArgSize(S.Context.getTypeSize(S.Context.IntTy), false);
1958 ArgSize = VectorArg->getNumElements();
1959 // Note that we use the "array bound" rules here; just like in that
1960 // case, we don't have any particular type for the vector size, but
1961 // we can provide one if necessary.
1962 return DeduceNonTypeTemplateArgument(S, TemplateParams, NTTP, ArgSize,
1963 S.Context.UnsignedIntTy, true,
1964 Info, Deduced);
1965 }
1966
1967 if (const auto *VectorArg = dyn_cast<DependentVectorType>(Arg)) {
1968 // Perform deduction on the element types.
1969 if (Sema::TemplateDeductionResult Result =
1970 DeduceTemplateArgumentsByTypeMatch(
1971 S, TemplateParams, VectorParam->getElementType(),
1972 VectorArg->getElementType(), Info, Deduced, TDF))
1973 return Result;
1974
1975 // Perform deduction on the vector size, if we can.
1976 NonTypeTemplateParmDecl *NTTP = getDeducedParameterFromExpr(
1977 Info, VectorParam->getSizeExpr());
1978 if (!NTTP)
1979 return Sema::TDK_Success;
1980
1981 return DeduceNonTypeTemplateArgument(
1982 S, TemplateParams, NTTP, VectorArg->getSizeExpr(), Info, Deduced);
1983 }
1984
1985 return Sema::TDK_NonDeducedMismatch;
1986 }
1987
1988 // (clang extension)
1989 //
1990 // T __attribute__(((ext_vector_type(N))))
1991 case Type::DependentSizedExtVector: {
1992 const DependentSizedExtVectorType *VectorParam
1993 = cast<DependentSizedExtVectorType>(Param);
1994
1995 if (const ExtVectorType *VectorArg = dyn_cast<ExtVectorType>(Arg)) {
1996 // Perform deduction on the element types.
1997 if (Sema::TemplateDeductionResult Result
1998 = DeduceTemplateArgumentsByTypeMatch(S, TemplateParams,
1999 VectorParam->getElementType(),
2000 VectorArg->getElementType(),
2001 Info, Deduced, TDF))
2002 return Result;
2003
2004 // Perform deduction on the vector size, if we can.
2005 NonTypeTemplateParmDecl *NTTP
2006 = getDeducedParameterFromExpr(Info, VectorParam->getSizeExpr());
2007 if (!NTTP)
2008 return Sema::TDK_Success;
2009
2010 llvm::APSInt ArgSize(S.Context.getTypeSize(S.Context.IntTy), false);
2011 ArgSize = VectorArg->getNumElements();
2012 // Note that we use the "array bound" rules here; just like in that
2013 // case, we don't have any particular type for the vector size, but
2014 // we can provide one if necessary.
2015 return DeduceNonTypeTemplateArgument(S, TemplateParams, NTTP, ArgSize,
2016 S.Context.IntTy, true, Info,
2017 Deduced);
2018 }
2019
2020 if (const DependentSizedExtVectorType *VectorArg
2021 = dyn_cast<DependentSizedExtVectorType>(Arg)) {
2022 // Perform deduction on the element types.
2023 if (Sema::TemplateDeductionResult Result
2024 = DeduceTemplateArgumentsByTypeMatch(S, TemplateParams,
2025 VectorParam->getElementType(),
2026 VectorArg->getElementType(),
2027 Info, Deduced, TDF))
2028 return Result;
2029
2030 // Perform deduction on the vector size, if we can.
2031 NonTypeTemplateParmDecl *NTTP
2032 = getDeducedParameterFromExpr(Info, VectorParam->getSizeExpr());
2033 if (!NTTP)
2034 return Sema::TDK_Success;
2035
2036 return DeduceNonTypeTemplateArgument(S, TemplateParams, NTTP,
2037 VectorArg->getSizeExpr(),
2038 Info, Deduced);
2039 }
2040
2041 return Sema::TDK_NonDeducedMismatch;
2042 }
2043
2044 // (clang extension)
2045 //
2046 // T __attribute__(((address_space(N))))
2047 case Type::DependentAddressSpace: {
2048 const DependentAddressSpaceType *AddressSpaceParam =
2049 cast<DependentAddressSpaceType>(Param);
2050
2051 if (const DependentAddressSpaceType *AddressSpaceArg =
2052 dyn_cast<DependentAddressSpaceType>(Arg)) {
2053 // Perform deduction on the pointer type.
2054 if (Sema::TemplateDeductionResult Result =
2055 DeduceTemplateArgumentsByTypeMatch(
2056 S, TemplateParams, AddressSpaceParam->getPointeeType(),
2057 AddressSpaceArg->getPointeeType(), Info, Deduced, TDF))
2058 return Result;
2059
2060 // Perform deduction on the address space, if we can.
2061 NonTypeTemplateParmDecl *NTTP = getDeducedParameterFromExpr(
2062 Info, AddressSpaceParam->getAddrSpaceExpr());
2063 if (!NTTP)
2064 return Sema::TDK_Success;
2065
2066 return DeduceNonTypeTemplateArgument(
2067 S, TemplateParams, NTTP, AddressSpaceArg->getAddrSpaceExpr(), Info,
2068 Deduced);
2069 }
2070
2071 if (isTargetAddressSpace(Arg.getAddressSpace())) {
2072 llvm::APSInt ArgAddressSpace(S.Context.getTypeSize(S.Context.IntTy),
2073 false);
2074 ArgAddressSpace = toTargetAddressSpace(Arg.getAddressSpace());
2075
2076 // Perform deduction on the pointer types.
2077 if (Sema::TemplateDeductionResult Result =
2078 DeduceTemplateArgumentsByTypeMatch(
2079 S, TemplateParams, AddressSpaceParam->getPointeeType(),
2080 S.Context.removeAddrSpaceQualType(Arg), Info, Deduced, TDF))
2081 return Result;
2082
2083 // Perform deduction on the address space, if we can.
2084 NonTypeTemplateParmDecl *NTTP = getDeducedParameterFromExpr(
2085 Info, AddressSpaceParam->getAddrSpaceExpr());
2086 if (!NTTP)
2087 return Sema::TDK_Success;
2088
2089 return DeduceNonTypeTemplateArgument(S, TemplateParams, NTTP,
2090 ArgAddressSpace, S.Context.IntTy,
2091 true, Info, Deduced);
2092 }
2093
2094 return Sema::TDK_NonDeducedMismatch;
2095 }
2096
2097 case Type::TypeOfExpr:
2098 case Type::TypeOf:
2099 case Type::DependentName:
2100 case Type::UnresolvedUsing:
2101 case Type::Decltype:
2102 case Type::UnaryTransform:
2103 case Type::Auto:
2104 case Type::DeducedTemplateSpecialization:
2105 case Type::DependentTemplateSpecialization:
2106 case Type::PackExpansion:
2107 case Type::Pipe:
2108 // No template argument deduction for these types
2109 return Sema::TDK_Success;
2110 }
2111
2112 llvm_unreachable("Invalid Type Class!")::llvm::llvm_unreachable_internal("Invalid Type Class!", "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 2112)
;
2113}
2114
2115static Sema::TemplateDeductionResult
2116DeduceTemplateArguments(Sema &S,
2117 TemplateParameterList *TemplateParams,
2118 const TemplateArgument &Param,
2119 TemplateArgument Arg,
2120 TemplateDeductionInfo &Info,
2121 SmallVectorImpl<DeducedTemplateArgument> &Deduced) {
2122 // If the template argument is a pack expansion, perform template argument
2123 // deduction against the pattern of that expansion. This only occurs during
2124 // partial ordering.
2125 if (Arg.isPackExpansion())
2126 Arg = Arg.getPackExpansionPattern();
2127
2128 switch (Param.getKind()) {
2129 case TemplateArgument::Null:
2130 llvm_unreachable("Null template argument in parameter list")::llvm::llvm_unreachable_internal("Null template argument in parameter list"
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 2130)
;
2131
2132 case TemplateArgument::Type:
2133 if (Arg.getKind() == TemplateArgument::Type)
2134 return DeduceTemplateArgumentsByTypeMatch(S, TemplateParams,
2135 Param.getAsType(),
2136 Arg.getAsType(),
2137 Info, Deduced, 0);
2138 Info.FirstArg = Param;
2139 Info.SecondArg = Arg;
2140 return Sema::TDK_NonDeducedMismatch;
2141
2142 case TemplateArgument::Template:
2143 if (Arg.getKind() == TemplateArgument::Template)
2144 return DeduceTemplateArguments(S, TemplateParams,
2145 Param.getAsTemplate(),
2146 Arg.getAsTemplate(), Info, Deduced);
2147 Info.FirstArg = Param;
2148 Info.SecondArg = Arg;
2149 return Sema::TDK_NonDeducedMismatch;
2150
2151 case TemplateArgument::TemplateExpansion:
2152 llvm_unreachable("caller should handle pack expansions")::llvm::llvm_unreachable_internal("caller should handle pack expansions"
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 2152)
;
2153
2154 case TemplateArgument::Declaration:
2155 if (Arg.getKind() == TemplateArgument::Declaration &&
2156 isSameDeclaration(Param.getAsDecl(), Arg.getAsDecl()))
2157 return Sema::TDK_Success;
2158
2159 Info.FirstArg = Param;
2160 Info.SecondArg = Arg;
2161 return Sema::TDK_NonDeducedMismatch;
2162
2163 case TemplateArgument::NullPtr:
2164 if (Arg.getKind() == TemplateArgument::NullPtr &&
2165 S.Context.hasSameType(Param.getNullPtrType(), Arg.getNullPtrType()))
2166 return Sema::TDK_Success;
2167
2168 Info.FirstArg = Param;
2169 Info.SecondArg = Arg;
2170 return Sema::TDK_NonDeducedMismatch;
2171
2172 case TemplateArgument::Integral:
2173 if (Arg.getKind() == TemplateArgument::Integral) {
2174 if (hasSameExtendedValue(Param.getAsIntegral(), Arg.getAsIntegral()))
2175 return Sema::TDK_Success;
2176
2177 Info.FirstArg = Param;
2178 Info.SecondArg = Arg;
2179 return Sema::TDK_NonDeducedMismatch;
2180 }
2181
2182 if (Arg.getKind() == TemplateArgument::Expression) {
2183 Info.FirstArg = Param;
2184 Info.SecondArg = Arg;
2185 return Sema::TDK_NonDeducedMismatch;
2186 }
2187
2188 Info.FirstArg = Param;
2189 Info.SecondArg = Arg;
2190 return Sema::TDK_NonDeducedMismatch;
2191
2192 case TemplateArgument::Expression:
2193 if (NonTypeTemplateParmDecl *NTTP
2194 = getDeducedParameterFromExpr(Info, Param.getAsExpr())) {
2195 if (Arg.getKind() == TemplateArgument::Integral)
2196 return DeduceNonTypeTemplateArgument(S, TemplateParams, NTTP,
2197 Arg.getAsIntegral(),
2198 Arg.getIntegralType(),
2199 /*ArrayBound=*/false,
2200 Info, Deduced);
2201 if (Arg.getKind() == TemplateArgument::NullPtr)
2202 return DeduceNullPtrTemplateArgument(S, TemplateParams, NTTP,
2203 Arg.getNullPtrType(),
2204 Info, Deduced);
2205 if (Arg.getKind() == TemplateArgument::Expression)
2206 return DeduceNonTypeTemplateArgument(S, TemplateParams, NTTP,
2207 Arg.getAsExpr(), Info, Deduced);
2208 if (Arg.getKind() == TemplateArgument::Declaration)
2209 return DeduceNonTypeTemplateArgument(S, TemplateParams, NTTP,
2210 Arg.getAsDecl(),
2211 Arg.getParamTypeForDecl(),
2212 Info, Deduced);
2213
2214 Info.FirstArg = Param;
2215 Info.SecondArg = Arg;
2216 return Sema::TDK_NonDeducedMismatch;
2217 }
2218
2219 // Can't deduce anything, but that's okay.
2220 return Sema::TDK_Success;
2221
2222 case TemplateArgument::Pack:
2223 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-8~svn345461/tools/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 2223)
;
2224 }
2225
2226 llvm_unreachable("Invalid TemplateArgument Kind!")::llvm::llvm_unreachable_internal("Invalid TemplateArgument Kind!"
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 2226)
;
2227}
2228
2229/// Determine whether there is a template argument to be used for
2230/// deduction.
2231///
2232/// This routine "expands" argument packs in-place, overriding its input
2233/// parameters so that \c Args[ArgIdx] will be the available template argument.
2234///
2235/// \returns true if there is another template argument (which will be at
2236/// \c Args[ArgIdx]), false otherwise.
2237static bool hasTemplateArgumentForDeduction(ArrayRef<TemplateArgument> &Args,
2238 unsigned &ArgIdx) {
2239 if (ArgIdx == Args.size())
2240 return false;
2241
2242 const TemplateArgument &Arg = Args[ArgIdx];
2243 if (Arg.getKind() != TemplateArgument::Pack)
2244 return true;
2245
2246 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-8~svn345461/tools/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 2246, __PRETTY_FUNCTION__))
;
2247 Args = Arg.pack_elements();
2248 ArgIdx = 0;
2249 return ArgIdx < Args.size();
2250}
2251
2252/// Determine whether the given set of template arguments has a pack
2253/// expansion that is not the last template argument.
2254static bool hasPackExpansionBeforeEnd(ArrayRef<TemplateArgument> Args) {
2255 bool FoundPackExpansion = false;
2256 for (const auto &A : Args) {
2257 if (FoundPackExpansion)
2258 return true;
2259
2260 if (A.getKind() == TemplateArgument::Pack)
2261 return hasPackExpansionBeforeEnd(A.pack_elements());
2262
2263 // FIXME: If this is a fixed-arity pack expansion from an outer level of
2264 // templates, it should not be treated as a pack expansion.
2265 if (A.isPackExpansion())
2266 FoundPackExpansion = true;
2267 }
2268
2269 return false;
2270}
2271
2272static Sema::TemplateDeductionResult
2273DeduceTemplateArguments(Sema &S, TemplateParameterList *TemplateParams,
2274 ArrayRef<TemplateArgument> Params,
2275 ArrayRef<TemplateArgument> Args,
2276 TemplateDeductionInfo &Info,
2277 SmallVectorImpl<DeducedTemplateArgument> &Deduced,
2278 bool NumberOfArgumentsMustMatch) {
2279 // C++0x [temp.deduct.type]p9:
2280 // If the template argument list of P contains a pack expansion that is not
2281 // the last template argument, the entire template argument list is a
2282 // non-deduced context.
2283 if (hasPackExpansionBeforeEnd(Params))
2284 return Sema::TDK_Success;
2285
2286 // C++0x [temp.deduct.type]p9:
2287 // If P has a form that contains <T> or <i>, then each argument Pi of the
2288 // respective template argument list P is compared with the corresponding
2289 // argument Ai of the corresponding template argument list of A.
2290 unsigned ArgIdx = 0, ParamIdx = 0;
2291 for (; hasTemplateArgumentForDeduction(Params, ParamIdx); ++ParamIdx) {
2292 if (!Params[ParamIdx].isPackExpansion()) {
2293 // The simple case: deduce template arguments by matching Pi and Ai.
2294
2295 // Check whether we have enough arguments.
2296 if (!hasTemplateArgumentForDeduction(Args, ArgIdx))
2297 return NumberOfArgumentsMustMatch
2298 ? Sema::TDK_MiscellaneousDeductionFailure
2299 : Sema::TDK_Success;
2300
2301 // C++1z [temp.deduct.type]p9:
2302 // During partial ordering, if Ai was originally a pack expansion [and]
2303 // Pi is not a pack expansion, template argument deduction fails.
2304 if (Args[ArgIdx].isPackExpansion())
2305 return Sema::TDK_MiscellaneousDeductionFailure;
2306
2307 // Perform deduction for this Pi/Ai pair.
2308 if (Sema::TemplateDeductionResult Result
2309 = DeduceTemplateArguments(S, TemplateParams,
2310 Params[ParamIdx], Args[ArgIdx],
2311 Info, Deduced))
2312 return Result;
2313
2314 // Move to the next argument.
2315 ++ArgIdx;
2316 continue;
2317 }
2318
2319 // The parameter is a pack expansion.
2320
2321 // C++0x [temp.deduct.type]p9:
2322 // If Pi is a pack expansion, then the pattern of Pi is compared with
2323 // each remaining argument in the template argument list of A. Each
2324 // comparison deduces template arguments for subsequent positions in the
2325 // template parameter packs expanded by Pi.
2326 TemplateArgument Pattern = Params[ParamIdx].getPackExpansionPattern();
2327
2328 // Prepare to deduce the packs within the pattern.
2329 PackDeductionScope PackScope(S, TemplateParams, Deduced, Info, Pattern);
2330
2331 // Keep track of the deduced template arguments for each parameter pack
2332 // expanded by this pack expansion (the outer index) and for each
2333 // template argument (the inner SmallVectors).
2334 for (; hasTemplateArgumentForDeduction(Args, ArgIdx) &&
2335 PackScope.hasNextElement();
2336 ++ArgIdx) {
2337 // Deduce template arguments from the pattern.
2338 if (Sema::TemplateDeductionResult Result
2339 = DeduceTemplateArguments(S, TemplateParams, Pattern, Args[ArgIdx],
2340 Info, Deduced))
2341 return Result;
2342
2343 PackScope.nextPackElement();
2344 }
2345
2346 // Build argument packs for each of the parameter packs expanded by this
2347 // pack expansion.
2348 if (auto Result = PackScope.finish())
2349 return Result;
2350 }
2351
2352 return Sema::TDK_Success;
2353}
2354
2355static Sema::TemplateDeductionResult
2356DeduceTemplateArguments(Sema &S,
2357 TemplateParameterList *TemplateParams,
2358 const TemplateArgumentList &ParamList,
2359 const TemplateArgumentList &ArgList,
2360 TemplateDeductionInfo &Info,
2361 SmallVectorImpl<DeducedTemplateArgument> &Deduced) {
2362 return DeduceTemplateArguments(S, TemplateParams, ParamList.asArray(),
2363 ArgList.asArray(), Info, Deduced,
2364 /*NumberOfArgumentsMustMatch*/false);
2365}
2366
2367/// Determine whether two template arguments are the same.
2368static bool isSameTemplateArg(ASTContext &Context,
2369 TemplateArgument X,
2370 const TemplateArgument &Y,
2371 bool PackExpansionMatchesPack = false) {
2372 // If we're checking deduced arguments (X) against original arguments (Y),
2373 // we will have flattened packs to non-expansions in X.
2374 if (PackExpansionMatchesPack && X.isPackExpansion() && !Y.isPackExpansion())
2375 X = X.getPackExpansionPattern();
2376
2377 if (X.getKind() != Y.getKind())
2378 return false;
2379
2380 switch (X.getKind()) {
2381 case TemplateArgument::Null:
2382 llvm_unreachable("Comparing NULL template argument")::llvm::llvm_unreachable_internal("Comparing NULL template argument"
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 2382)
;
2383
2384 case TemplateArgument::Type:
2385 return Context.getCanonicalType(X.getAsType()) ==
2386 Context.getCanonicalType(Y.getAsType());
2387
2388 case TemplateArgument::Declaration:
2389 return isSameDeclaration(X.getAsDecl(), Y.getAsDecl());
2390
2391 case TemplateArgument::NullPtr:
2392 return Context.hasSameType(X.getNullPtrType(), Y.getNullPtrType());
2393
2394 case TemplateArgument::Template:
2395 case TemplateArgument::TemplateExpansion:
2396 return Context.getCanonicalTemplateName(
2397 X.getAsTemplateOrTemplatePattern()).getAsVoidPointer() ==
2398 Context.getCanonicalTemplateName(
2399 Y.getAsTemplateOrTemplatePattern()).getAsVoidPointer();
2400
2401 case TemplateArgument::Integral:
2402 return hasSameExtendedValue(X.getAsIntegral(), Y.getAsIntegral());
2403
2404 case TemplateArgument::Expression: {
2405 llvm::FoldingSetNodeID XID, YID;
2406 X.getAsExpr()->Profile(XID, Context, true);
2407 Y.getAsExpr()->Profile(YID, Context, true);
2408 return XID == YID;
2409 }
2410
2411 case TemplateArgument::Pack:
2412 if (X.pack_size() != Y.pack_size())
2413 return false;
2414
2415 for (TemplateArgument::pack_iterator XP = X.pack_begin(),
2416 XPEnd = X.pack_end(),
2417 YP = Y.pack_begin();
2418 XP != XPEnd; ++XP, ++YP)
2419 if (!isSameTemplateArg(Context, *XP, *YP, PackExpansionMatchesPack))
2420 return false;
2421
2422 return true;
2423 }
2424
2425 llvm_unreachable("Invalid TemplateArgument Kind!")::llvm::llvm_unreachable_internal("Invalid TemplateArgument Kind!"
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 2425)
;
2426}
2427
2428/// Allocate a TemplateArgumentLoc where all locations have
2429/// been initialized to the given location.
2430///
2431/// \param Arg The template argument we are producing template argument
2432/// location information for.
2433///
2434/// \param NTTPType For a declaration template argument, the type of
2435/// the non-type template parameter that corresponds to this template
2436/// argument. Can be null if no type sugar is available to add to the
2437/// type from the template argument.
2438///
2439/// \param Loc The source location to use for the resulting template
2440/// argument.
2441TemplateArgumentLoc
2442Sema::getTrivialTemplateArgumentLoc(const TemplateArgument &Arg,
2443 QualType NTTPType, SourceLocation Loc) {
2444 switch (Arg.getKind()) {
2445 case TemplateArgument::Null:
2446 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-8~svn345461/tools/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 2446)
;
2447
2448 case TemplateArgument::Type:
2449 return TemplateArgumentLoc(
2450 Arg, Context.getTrivialTypeSourceInfo(Arg.getAsType(), Loc));
2451
2452 case TemplateArgument::Declaration: {
2453 if (NTTPType.isNull())
2454 NTTPType = Arg.getParamTypeForDecl();
2455 Expr *E = BuildExpressionFromDeclTemplateArgument(Arg, NTTPType, Loc)
2456 .getAs<Expr>();
2457 return TemplateArgumentLoc(TemplateArgument(E), E);
2458 }
2459
2460 case TemplateArgument::NullPtr: {
2461 if (NTTPType.isNull())
2462 NTTPType = Arg.getNullPtrType();
2463 Expr *E = BuildExpressionFromDeclTemplateArgument(Arg, NTTPType, Loc)
2464 .getAs<Expr>();
2465 return TemplateArgumentLoc(TemplateArgument(NTTPType, /*isNullPtr*/true),
2466 E);
2467 }
2468
2469 case TemplateArgument::Integral: {
2470 Expr *E =
2471 BuildExpressionFromIntegralTemplateArgument(Arg, Loc).getAs<Expr>();
2472 return TemplateArgumentLoc(TemplateArgument(E), E);
2473 }
2474
2475 case TemplateArgument::Template:
2476 case TemplateArgument::TemplateExpansion: {
2477 NestedNameSpecifierLocBuilder Builder;
2478 TemplateName Template = Arg.getAsTemplate();
2479 if (DependentTemplateName *DTN = Template.getAsDependentTemplateName())
2480 Builder.MakeTrivial(Context, DTN->getQualifier(), Loc);
2481 else if (QualifiedTemplateName *QTN =
2482 Template.getAsQualifiedTemplateName())
2483 Builder.MakeTrivial(Context, QTN->getQualifier(), Loc);
2484
2485 if (Arg.getKind() == TemplateArgument::Template)
2486 return TemplateArgumentLoc(Arg, Builder.getWithLocInContext(Context),
2487 Loc);
2488
2489 return TemplateArgumentLoc(Arg, Builder.getWithLocInContext(Context),
2490 Loc, Loc);
2491 }
2492
2493 case TemplateArgument::Expression:
2494 return TemplateArgumentLoc(Arg, Arg.getAsExpr());
2495
2496 case TemplateArgument::Pack:
2497 return TemplateArgumentLoc(Arg, TemplateArgumentLocInfo());
2498 }
2499
2500 llvm_unreachable("Invalid TemplateArgument Kind!")::llvm::llvm_unreachable_internal("Invalid TemplateArgument Kind!"
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 2500)
;
2501}
2502
2503/// Convert the given deduced template argument and add it to the set of
2504/// fully-converted template arguments.
2505static bool
2506ConvertDeducedTemplateArgument(Sema &S, NamedDecl *Param,
2507 DeducedTemplateArgument Arg,
2508 NamedDecl *Template,
2509 TemplateDeductionInfo &Info,
2510 bool IsDeduced,
2511 SmallVectorImpl<TemplateArgument> &Output) {
2512 auto ConvertArg = [&](DeducedTemplateArgument Arg,
2513 unsigned ArgumentPackIndex) {
2514 // Convert the deduced template argument into a template
2515 // argument that we can check, almost as if the user had written
2516 // the template argument explicitly.
2517 TemplateArgumentLoc ArgLoc =
2518 S.getTrivialTemplateArgumentLoc(Arg, QualType(), Info.getLocation());
2519
2520 // Check the template argument, converting it as necessary.
2521 return S.CheckTemplateArgument(
2522 Param, ArgLoc, Template, Template->getLocation(),
2523 Template->getSourceRange().getEnd(), ArgumentPackIndex, Output,
2524 IsDeduced
2525 ? (Arg.wasDeducedFromArrayBound() ? Sema::CTAK_DeducedFromArrayBound
2526 : Sema::CTAK_Deduced)
2527 : Sema::CTAK_Specified);
2528 };
2529
2530 if (Arg.getKind() == TemplateArgument::Pack) {
2531 // This is a template argument pack, so check each of its arguments against
2532 // the template parameter.
2533 SmallVector<TemplateArgument, 2> PackedArgsBuilder;
2534 for (const auto &P : Arg.pack_elements()) {
2535 // When converting the deduced template argument, append it to the
2536 // general output list. We need to do this so that the template argument
2537 // checking logic has all of the prior template arguments available.
2538 DeducedTemplateArgument InnerArg(P);
2539 InnerArg.setDeducedFromArrayBound(Arg.wasDeducedFromArrayBound());
2540 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-8~svn345461/tools/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 2541, __PRETTY_FUNCTION__))
2541 "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-8~svn345461/tools/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 2541, __PRETTY_FUNCTION__))
;
2542 if (P.isNull()) {
2543 // We deduced arguments for some elements of this pack, but not for
2544 // all of them. This happens if we get a conditionally-non-deduced
2545 // context in a pack expansion (such as an overload set in one of the
2546 // arguments).
2547 S.Diag(Param->getLocation(),
2548 diag::err_template_arg_deduced_incomplete_pack)
2549 << Arg << Param;
2550 return true;
2551 }
2552 if (ConvertArg(InnerArg, PackedArgsBuilder.size()))
2553 return true;
2554
2555 // Move the converted template argument into our argument pack.
2556 PackedArgsBuilder.push_back(Output.pop_back_val());
2557 }
2558
2559 // If the pack is empty, we still need to substitute into the parameter
2560 // itself, in case that substitution fails.
2561 if (PackedArgsBuilder.empty()) {
2562 LocalInstantiationScope Scope(S);
2563 TemplateArgumentList TemplateArgs(TemplateArgumentList::OnStack, Output);
2564 MultiLevelTemplateArgumentList Args(TemplateArgs);
2565
2566 if (auto *NTTP = dyn_cast<NonTypeTemplateParmDecl>(Param)) {
2567 Sema::InstantiatingTemplate Inst(S, Template->getLocation(), Template,
2568 NTTP, Output,
2569 Template->getSourceRange());
2570 if (Inst.isInvalid() ||
2571 S.SubstType(NTTP->getType(), Args, NTTP->getLocation(),
2572 NTTP->getDeclName()).isNull())
2573 return true;
2574 } else if (auto *TTP = dyn_cast<TemplateTemplateParmDecl>(Param)) {
2575 Sema::InstantiatingTemplate Inst(S, Template->getLocation(), Template,
2576 TTP, Output,
2577 Template->getSourceRange());
2578 if (Inst.isInvalid() || !S.SubstDecl(TTP, S.CurContext, Args))
2579 return true;
2580 }
2581 // For type parameters, no substitution is ever required.
2582 }
2583
2584 // Create the resulting argument pack.
2585 Output.push_back(
2586 TemplateArgument::CreatePackCopy(S.Context, PackedArgsBuilder));
2587 return false;
2588 }
2589
2590 return ConvertArg(Arg, 0);
2591}
2592
2593// FIXME: This should not be a template, but
2594// ClassTemplatePartialSpecializationDecl sadly does not derive from
2595// TemplateDecl.
2596template<typename TemplateDeclT>
2597static Sema::TemplateDeductionResult ConvertDeducedTemplateArguments(
2598 Sema &S, TemplateDeclT *Template, bool IsDeduced,
2599 SmallVectorImpl<DeducedTemplateArgument> &Deduced,
2600 TemplateDeductionInfo &Info, SmallVectorImpl<TemplateArgument> &Builder,
2601 LocalInstantiationScope *CurrentInstantiationScope = nullptr,
2602 unsigned NumAlreadyConverted = 0, bool PartialOverloading = false) {
2603 TemplateParameterList *TemplateParams = Template->getTemplateParameters();
2604
2605 for (unsigned I = 0, N = TemplateParams->size(); I != N; ++I) {
2606 NamedDecl *Param = TemplateParams->getParam(I);
2607
2608 // C++0x [temp.arg.explicit]p3:
2609 // A trailing template parameter pack (14.5.3) not otherwise deduced will
2610 // be deduced to an empty sequence of template arguments.
2611 // FIXME: Where did the word "trailing" come from?
2612 if (Deduced[I].isNull() && Param->isTemplateParameterPack()) {
2613 if (auto Result = PackDeductionScope(S, TemplateParams, Deduced, Info, I)
2614 .finish(/*TreatNoDeductionsAsNonDeduced*/false))
2615 return Result;
2616 }
2617
2618 if (!Deduced[I].isNull()) {
2619 if (I < NumAlreadyConverted) {
2620 // We may have had explicitly-specified template arguments for a
2621 // template parameter pack (that may or may not have been extended
2622 // via additional deduced arguments).
2623 if (Param->isParameterPack() && CurrentInstantiationScope &&
2624 CurrentInstantiationScope->getPartiallySubstitutedPack() == Param) {
2625 // Forget the partially-substituted pack; its substitution is now
2626 // complete.
2627 CurrentInstantiationScope->ResetPartiallySubstitutedPack();
2628 // We still need to check the argument in case it was extended by
2629 // deduction.
2630 } else {
2631 // We have already fully type-checked and converted this
2632 // argument, because it was explicitly-specified. Just record the
2633 // presence of this argument.
2634 Builder.push_back(Deduced[I]);
2635 continue;
2636 }
2637 }
2638
2639 // We may have deduced this argument, so it still needs to be
2640 // checked and converted.
2641 if (ConvertDeducedTemplateArgument(S, Param, Deduced[I], Template, Info,
2642 IsDeduced, Builder)) {
2643 Info.Param = makeTemplateParameter(Param);
2644 // FIXME: These template arguments are temporary. Free them!
2645 Info.reset(TemplateArgumentList::CreateCopy(S.Context, Builder));
2646 return Sema::TDK_SubstitutionFailure;
2647 }
2648
2649 continue;
2650 }
2651
2652 // Substitute into the default template argument, if available.
2653 bool HasDefaultArg = false;
2654 TemplateDecl *TD = dyn_cast<TemplateDecl>(Template);
2655 if (!TD) {
2656 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-8~svn345461/tools/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 2657, __PRETTY_FUNCTION__))
2657 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-8~svn345461/tools/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 2657, __PRETTY_FUNCTION__))
;
2658 return Sema::TDK_Incomplete;
2659 }
2660
2661 TemplateArgumentLoc DefArg = S.SubstDefaultTemplateArgumentIfAvailable(
2662 TD, TD->getLocation(), TD->getSourceRange().getEnd(), Param, Builder,
2663 HasDefaultArg);
2664
2665 // If there was no default argument, deduction is incomplete.
2666 if (DefArg.getArgument().isNull()) {
2667 Info.Param = makeTemplateParameter(
2668 const_cast<NamedDecl *>(TemplateParams->getParam(I)));
2669 Info.reset(TemplateArgumentList::CreateCopy(S.Context, Builder));
2670 if (PartialOverloading) break;
2671
2672 return HasDefaultArg ? Sema::TDK_SubstitutionFailure
2673 : Sema::TDK_Incomplete;
2674 }
2675
2676 // Check whether we can actually use the default argument.
2677 if (S.CheckTemplateArgument(Param, DefArg, TD, TD->getLocation(),
2678 TD->getSourceRange().getEnd(), 0, Builder,
2679 Sema::CTAK_Specified)) {
2680 Info.Param = makeTemplateParameter(
2681 const_cast<NamedDecl *>(TemplateParams->getParam(I)));
2682 // FIXME: These template arguments are temporary. Free them!
2683 Info.reset(TemplateArgumentList::CreateCopy(S.Context, Builder));
2684 return Sema::TDK_SubstitutionFailure;
2685 }
2686
2687 // If we get here, we successfully used the default template argument.
2688 }
2689
2690 return Sema::TDK_Success;
2691}
2692
2693static DeclContext *getAsDeclContextOrEnclosing(Decl *D) {
2694 if (auto *DC = dyn_cast<DeclContext>(D))
2695 return DC;
2696 return D->getDeclContext();
2697}
2698
2699template<typename T> struct IsPartialSpecialization {
2700 static constexpr bool value = false;
2701};
2702template<>
2703struct IsPartialSpecialization<ClassTemplatePartialSpecializationDecl> {
2704 static constexpr bool value = true;
2705};
2706template<>
2707struct IsPartialSpecialization<VarTemplatePartialSpecializationDecl> {
2708 static constexpr bool value = true;
2709};
2710
2711/// Complete template argument deduction for a partial specialization.
2712template <typename T>
2713static typename std::enable_if<IsPartialSpecialization<T>::value,
2714 Sema::TemplateDeductionResult>::type
2715FinishTemplateArgumentDeduction(
2716 Sema &S, T *Partial, bool IsPartialOrdering,
2717 const TemplateArgumentList &TemplateArgs,
2718 SmallVectorImpl<DeducedTemplateArgument> &Deduced,
2719 TemplateDeductionInfo &Info) {
2720 // Unevaluated SFINAE context.
2721 EnterExpressionEvaluationContext Unevaluated(
2722 S, Sema::ExpressionEvaluationContext::Unevaluated);
2723 Sema::SFINAETrap Trap(S);
2724
2725 Sema::ContextRAII SavedContext(S, getAsDeclContextOrEnclosing(Partial));
2726
2727 // C++ [temp.deduct.type]p2:
2728 // [...] or if any template argument remains neither deduced nor
2729 // explicitly specified, template argument deduction fails.
2730 SmallVector<TemplateArgument, 4> Builder;
2731 if (auto Result = ConvertDeducedTemplateArguments(
2732 S, Partial, IsPartialOrdering, Deduced, Info, Builder))
2733 return Result;
2734
2735 // Form the template argument list from the deduced template arguments.
2736 TemplateArgumentList *DeducedArgumentList
2737 = TemplateArgumentList::CreateCopy(S.Context, Builder);
2738
2739 Info.reset(DeducedArgumentList);
2740
2741 // Substitute the deduced template arguments into the template
2742 // arguments of the class template partial specialization, and
2743 // verify that the instantiated template arguments are both valid
2744 // and are equivalent to the template arguments originally provided
2745 // to the class template.
2746 LocalInstantiationScope InstScope(S);
2747 auto *Template = Partial->getSpecializedTemplate();
2748 const ASTTemplateArgumentListInfo *PartialTemplArgInfo =
2749 Partial->getTemplateArgsAsWritten();
2750 const TemplateArgumentLoc *PartialTemplateArgs =
2751 PartialTemplArgInfo->getTemplateArgs();
2752
2753 TemplateArgumentListInfo InstArgs(PartialTemplArgInfo->LAngleLoc,
2754 PartialTemplArgInfo->RAngleLoc);
2755
2756 if (S.Subst(PartialTemplateArgs, PartialTemplArgInfo->NumTemplateArgs,
2757 InstArgs, MultiLevelTemplateArgumentList(*DeducedArgumentList))) {
2758 unsigned ArgIdx = InstArgs.size(), ParamIdx = ArgIdx;
2759 if (ParamIdx >= Partial->getTemplateParameters()->size())
2760 ParamIdx = Partial->getTemplateParameters()->size() - 1;
2761
2762 Decl *Param = const_cast<NamedDecl *>(
2763 Partial->getTemplateParameters()->getParam(ParamIdx));
2764 Info.Param = makeTemplateParameter(Param);
2765 Info.FirstArg = PartialTemplateArgs[ArgIdx].getArgument();
2766 return Sema::TDK_SubstitutionFailure;
2767 }
2768
2769 SmallVector<TemplateArgument, 4> ConvertedInstArgs;
2770 if (S.CheckTemplateArgumentList(Template, Partial->getLocation(), InstArgs,
2771 false, ConvertedInstArgs))
2772 return Sema::TDK_SubstitutionFailure;
2773
2774 TemplateParameterList *TemplateParams = Template->getTemplateParameters();
2775 for (unsigned I = 0, E = TemplateParams->size(); I != E; ++I) {
2776 TemplateArgument InstArg = ConvertedInstArgs.data()[I];
2777 if (!isSameTemplateArg(S.Context, TemplateArgs[I], InstArg)) {
2778 Info.Param = makeTemplateParameter(TemplateParams->getParam(I));
2779 Info.FirstArg = TemplateArgs[I];
2780 Info.SecondArg = InstArg;
2781 return Sema::TDK_NonDeducedMismatch;
2782 }
2783 }
2784
2785 if (Trap.hasErrorOccurred())
2786 return Sema::TDK_SubstitutionFailure;
2787
2788 return Sema::TDK_Success;
2789}
2790
2791/// Complete template argument deduction for a class or variable template,
2792/// when partial ordering against a partial specialization.
2793// FIXME: Factor out duplication with partial specialization version above.
2794static Sema::TemplateDeductionResult FinishTemplateArgumentDeduction(
2795 Sema &S, TemplateDecl *Template, bool PartialOrdering,
2796 const TemplateArgumentList &TemplateArgs,
2797 SmallVectorImpl<DeducedTemplateArgument> &Deduced,
2798 TemplateDeductionInfo &Info) {
2799 // Unevaluated SFINAE context.
2800 EnterExpressionEvaluationContext Unevaluated(
2801 S, Sema::ExpressionEvaluationContext::Unevaluated);
2802 Sema::SFINAETrap Trap(S);
2803
2804 Sema::ContextRAII SavedContext(S, getAsDeclContextOrEnclosing(Template));
2805
2806 // C++ [temp.deduct.type]p2:
2807 // [...] or if any template argument remains neither deduced nor
2808 // explicitly specified, template argument deduction fails.
2809 SmallVector<TemplateArgument, 4> Builder;
2810 if (auto Result = ConvertDeducedTemplateArguments(
2811 S, Template, /*IsDeduced*/PartialOrdering, Deduced, Info, Builder))
2812 return Result;
2813
2814 // Check that we produced the correct argument list.
2815 TemplateParameterList *TemplateParams = Template->getTemplateParameters();
2816 for (unsigned I = 0, E = TemplateParams->size(); I != E; ++I) {
2817 TemplateArgument InstArg = Builder[I];
2818 if (!isSameTemplateArg(S.Context, TemplateArgs[I], InstArg,
2819 /*PackExpansionMatchesPack*/true)) {
2820 Info.Param = makeTemplateParameter(TemplateParams->getParam(I));
2821 Info.FirstArg = TemplateArgs[I];
2822 Info.SecondArg = InstArg;
2823 return Sema::TDK_NonDeducedMismatch;
2824 }
2825 }
2826
2827 if (Trap.hasErrorOccurred())
2828 return Sema::TDK_SubstitutionFailure;
2829
2830 return Sema::TDK_Success;
2831}
2832
2833
2834/// Perform template argument deduction to determine whether
2835/// the given template arguments match the given class template
2836/// partial specialization per C++ [temp.class.spec.match].
2837Sema::TemplateDeductionResult
2838Sema::DeduceTemplateArguments(ClassTemplatePartialSpecializationDecl *Partial,
2839 const TemplateArgumentList &TemplateArgs,
2840 TemplateDeductionInfo &Info) {
2841 if (Partial->isInvalidDecl())
2842 return TDK_Invalid;
2843
2844 // C++ [temp.class.spec.match]p2:
2845 // A partial specialization matches a given actual template
2846 // argument list if the template arguments of the partial
2847 // specialization can be deduced from the actual template argument
2848 // list (14.8.2).
2849
2850 // Unevaluated SFINAE context.
2851 EnterExpressionEvaluationContext Unevaluated(
2852 *this, Sema::ExpressionEvaluationContext::Unevaluated);
2853 SFINAETrap Trap(*this);
2854
2855 SmallVector<DeducedTemplateArgument, 4> Deduced;
2856 Deduced.resize(Partial->getTemplateParameters()->size());
2857 if (TemplateDeductionResult Result
2858 = ::DeduceTemplateArguments(*this,
2859 Partial->getTemplateParameters(),
2860 Partial->getTemplateArgs(),
2861 TemplateArgs, Info, Deduced))
2862 return Result;
2863
2864 SmallVector<TemplateArgument, 4> DeducedArgs(Deduced.begin(), Deduced.end());
2865 InstantiatingTemplate Inst(*this, Info.getLocation(), Partial, DeducedArgs,
2866 Info);
2867 if (Inst.isInvalid())
2868 return TDK_InstantiationDepth;
2869
2870 if (Trap.hasErrorOccurred())
2871 return Sema::TDK_SubstitutionFailure;
2872
2873 return ::FinishTemplateArgumentDeduction(
2874 *this, Partial, /*PartialOrdering=*/false, TemplateArgs, Deduced, Info);
2875}
2876
2877/// Perform template argument deduction to determine whether
2878/// the given template arguments match the given variable template
2879/// partial specialization per C++ [temp.class.spec.match].
2880Sema::TemplateDeductionResult
2881Sema::DeduceTemplateArguments(VarTemplatePartialSpecializationDecl *Partial,
2882 const TemplateArgumentList &TemplateArgs,
2883 TemplateDeductionInfo &Info) {
2884 if (Partial->isInvalidDecl())
2885 return TDK_Invalid;
2886
2887 // C++ [temp.class.spec.match]p2:
2888 // A partial specialization matches a given actual template
2889 // argument list if the template arguments of the partial
2890 // specialization can be deduced from the actual template argument
2891 // list (14.8.2).
2892
2893 // Unevaluated SFINAE context.
2894 EnterExpressionEvaluationContext Unevaluated(
2895 *this, Sema::ExpressionEvaluationContext::Unevaluated);
2896 SFINAETrap Trap(*this);
2897
2898 SmallVector<DeducedTemplateArgument, 4> Deduced;
2899 Deduced.resize(Partial->getTemplateParameters()->size());
2900 if (TemplateDeductionResult Result = ::DeduceTemplateArguments(
2901 *this, Partial->getTemplateParameters(), Partial->getTemplateArgs(),
2902 TemplateArgs, Info, Deduced))
2903 return Result;
2904
2905 SmallVector<TemplateArgument, 4> DeducedArgs(Deduced.begin(), Deduced.end());
2906 InstantiatingTemplate Inst(*this, Info.getLocation(), Partial, DeducedArgs,
2907 Info);
2908 if (Inst.isInvalid())
2909 return TDK_InstantiationDepth;
2910
2911 if (Trap.hasErrorOccurred())
2912 return Sema::TDK_SubstitutionFailure;
2913
2914 return ::FinishTemplateArgumentDeduction(
2915 *this, Partial, /*PartialOrdering=*/false, TemplateArgs, Deduced, Info);
2916}
2917
2918/// Determine whether the given type T is a simple-template-id type.
2919static bool isSimpleTemplateIdType(QualType T) {
2920 if (const TemplateSpecializationType *Spec
2921 = T->getAs<TemplateSpecializationType>())
2922 return Spec->getTemplateName().getAsTemplateDecl() != nullptr;
2923
2924 // C++17 [temp.local]p2:
2925 // the injected-class-name [...] is equivalent to the template-name followed
2926 // by the template-arguments of the class template specialization or partial
2927 // specialization enclosed in <>
2928 // ... which means it's equivalent to a simple-template-id.
2929 //
2930 // This only arises during class template argument deduction for a copy
2931 // deduction candidate, where it permits slicing.
2932 if (T->getAs<InjectedClassNameType>())
2933 return true;
2934
2935 return false;
2936}
2937
2938/// Substitute the explicitly-provided template arguments into the
2939/// given function template according to C++ [temp.arg.explicit].
2940///
2941/// \param FunctionTemplate the function template into which the explicit
2942/// template arguments will be substituted.
2943///
2944/// \param ExplicitTemplateArgs the explicitly-specified template
2945/// arguments.
2946///
2947/// \param Deduced the deduced template arguments, which will be populated
2948/// with the converted and checked explicit template arguments.
2949///
2950/// \param ParamTypes will be populated with the instantiated function
2951/// parameters.
2952///
2953/// \param FunctionType if non-NULL, the result type of the function template
2954/// will also be instantiated and the pointed-to value will be updated with
2955/// the instantiated function type.
2956///
2957/// \param Info if substitution fails for any reason, this object will be
2958/// populated with more information about the failure.
2959///
2960/// \returns TDK_Success if substitution was successful, or some failure
2961/// condition.
2962Sema::TemplateDeductionResult
2963Sema::SubstituteExplicitTemplateArguments(
2964 FunctionTemplateDecl *FunctionTemplate,
2965 TemplateArgumentListInfo &ExplicitTemplateArgs,
2966 SmallVectorImpl<DeducedTemplateArgument> &Deduced,
2967 SmallVectorImpl<QualType> &ParamTypes,
2968 QualType *FunctionType,
2969 TemplateDeductionInfo &Info) {
2970 FunctionDecl *Function = FunctionTemplate->getTemplatedDecl();
2971 TemplateParameterList *TemplateParams
2972 = FunctionTemplate->getTemplateParameters();
2973
2974 if (ExplicitTemplateArgs.size() == 0) {
2975 // No arguments to substitute; just copy over the parameter types and
2976 // fill in the function type.
2977 for (auto P : Function->parameters())
2978 ParamTypes.push_back(P->getType());
2979
2980 if (FunctionType)
2981 *FunctionType = Function->getType();
2982 return TDK_Success;
2983 }
2984
2985 // Unevaluated SFINAE context.
2986 EnterExpressionEvaluationContext Unevaluated(
2987 *this, Sema::ExpressionEvaluationContext::Unevaluated);
2988 SFINAETrap Trap(*this);
2989
2990 // C++ [temp.arg.explicit]p3:
2991 // Template arguments that are present shall be specified in the
2992 // declaration order of their corresponding template-parameters. The
2993 // template argument list shall not specify more template-arguments than
2994 // there are corresponding template-parameters.
2995 SmallVector<TemplateArgument, 4> Builder;
2996
2997 // Enter a new template instantiation context where we check the
2998 // explicitly-specified template arguments against this function template,
2999 // and then substitute them into the function parameter types.
3000 SmallVector<TemplateArgument, 4> DeducedArgs;
3001 InstantiatingTemplate Inst(
3002 *this, Info.getLocation(), FunctionTemplate, DeducedArgs,
3003 CodeSynthesisContext::ExplicitTemplateArgumentSubstitution, Info);
3004 if (Inst.isInvalid())
3005 return TDK_InstantiationDepth;
3006
3007 if (CheckTemplateArgumentList(FunctionTemplate, SourceLocation(),
3008 ExplicitTemplateArgs, true, Builder, false) ||
3009 Trap.hasErrorOccurred()) {
3010 unsigned Index = Builder.size();
3011 if (Index >= TemplateParams->size())
3012 return TDK_SubstitutionFailure;
3013 Info.Param = makeTemplateParameter(TemplateParams->getParam(Index));
3014 return TDK_InvalidExplicitArguments;
3015 }
3016
3017 // Form the template argument list from the explicitly-specified
3018 // template arguments.
3019 TemplateArgumentList *ExplicitArgumentList
3020 = TemplateArgumentList::CreateCopy(Context, Builder);
3021 Info.setExplicitArgs(ExplicitArgumentList);
3022
3023 // Template argument deduction and the final substitution should be
3024 // done in the context of the templated declaration. Explicit
3025 // argument substitution, on the other hand, needs to happen in the
3026 // calling context.
3027 ContextRAII SavedContext(*this, FunctionTemplate->getTemplatedDecl());
3028
3029 // If we deduced template arguments for a template parameter pack,
3030 // note that the template argument pack is partially substituted and record
3031 // the explicit template arguments. They'll be used as part of deduction
3032 // for this template parameter pack.
3033 unsigned PartiallySubstitutedPackIndex = -1u;
3034 if (!Builder.empty()) {
3035 const TemplateArgument &Arg = Builder.back();
3036 if (Arg.getKind() == TemplateArgument::Pack) {
3037 auto *Param = TemplateParams->getParam(Builder.size() - 1);
3038 // If this is a fully-saturated fixed-size pack, it should be
3039 // fully-substituted, not partially-substituted.
3040 Optional<unsigned> Expansions = getExpandedPackSize(Param);
3041 if (!Expansions || Arg.pack_size() < *Expansions) {
3042 PartiallySubstitutedPackIndex = Builder.size() - 1;
3043 CurrentInstantiationScope->SetPartiallySubstitutedPack(
3044 Param, Arg.pack_begin(), Arg.pack_size());
3045 }
3046 }
3047 }
3048
3049 const FunctionProtoType *Proto
3050 = Function->getType()->getAs<FunctionProtoType>();
3051 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-8~svn345461/tools/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 3051, __PRETTY_FUNCTION__))
;
3052
3053 // Isolate our substituted parameters from our caller.
3054 LocalInstantiationScope InstScope(*this, /*MergeWithOuterScope*/true);
3055
3056 ExtParameterInfoBuilder ExtParamInfos;
3057
3058 // Instantiate the types of each of the function parameters given the
3059 // explicitly-specified template arguments. If the function has a trailing
3060 // return type, substitute it after the arguments to ensure we substitute
3061 // in lexical order.
3062 if (Proto->hasTrailingReturn()) {
3063 if (SubstParmTypes(Function->getLocation(), Function->parameters(),
3064 Proto->getExtParameterInfosOrNull(),
3065 MultiLevelTemplateArgumentList(*ExplicitArgumentList),
3066 ParamTypes, /*params*/ nullptr, ExtParamInfos))
3067 return TDK_SubstitutionFailure;
3068 }
3069
3070 // Instantiate the return type.
3071 QualType ResultType;
3072 {
3073 // C++11 [expr.prim.general]p3:
3074 // If a declaration declares a member function or member function
3075 // template of a class X, the expression this is a prvalue of type
3076 // "pointer to cv-qualifier-seq X" between the optional cv-qualifer-seq
3077 // and the end of the function-definition, member-declarator, or
3078 // declarator.
3079 unsigned ThisTypeQuals = 0;
3080 CXXRecordDecl *ThisContext = nullptr;
3081 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Function)) {
3082 ThisContext = Method->getParent();
3083 ThisTypeQuals = Method->getTypeQualifiers();
3084 }
3085
3086 CXXThisScopeRAII ThisScope(*this, ThisContext, ThisTypeQuals,
3087 getLangOpts().CPlusPlus11);
3088
3089 ResultType =
3090 SubstType(Proto->getReturnType(),
3091 MultiLevelTemplateArgumentList(*ExplicitArgumentList),
3092 Function->getTypeSpecStartLoc(), Function->getDeclName());
3093 if (ResultType.isNull() || Trap.hasErrorOccurred())
3094 return TDK_SubstitutionFailure;
3095 }
3096
3097 // Instantiate the types of each of the function parameters given the
3098 // explicitly-specified template arguments if we didn't do so earlier.
3099 if (!Proto->hasTrailingReturn() &&
3100 SubstParmTypes(Function->getLocation(), Function->parameters(),
3101 Proto->getExtParameterInfosOrNull(),
3102 MultiLevelTemplateArgumentList(*ExplicitArgumentList),
3103 ParamTypes, /*params*/ nullptr, ExtParamInfos))
3104 return TDK_SubstitutionFailure;
3105
3106 if (FunctionType) {
3107 auto EPI = Proto->getExtProtoInfo();
3108 EPI.ExtParameterInfos = ExtParamInfos.getPointerOrNull(ParamTypes.size());
3109
3110 // In C++1z onwards, exception specifications are part of the function type,
3111 // so substitution into the type must also substitute into the exception
3112 // specification.
3113 SmallVector<QualType, 4> ExceptionStorage;
3114 if (getLangOpts().CPlusPlus17 &&
3115 SubstExceptionSpec(
3116 Function->getLocation(), EPI.ExceptionSpec, ExceptionStorage,
3117 MultiLevelTemplateArgumentList(*ExplicitArgumentList)))
3118 return TDK_SubstitutionFailure;
3119
3120 *FunctionType = BuildFunctionType(ResultType, ParamTypes,
3121 Function->getLocation(),
3122 Function->getDeclName(),
3123 EPI);
3124 if (FunctionType->isNull() || Trap.hasErrorOccurred())
3125 return TDK_SubstitutionFailure;
3126 }
3127
3128 // C++ [temp.arg.explicit]p2:
3129 // Trailing template arguments that can be deduced (14.8.2) may be
3130 // omitted from the list of explicit template-arguments. If all of the
3131 // template arguments can be deduced, they may all be omitted; in this
3132 // case, the empty template argument list <> itself may also be omitted.
3133 //
3134 // Take all of the explicitly-specified arguments and put them into
3135 // the set of deduced template arguments. The partially-substituted
3136 // parameter pack, however, will be set to NULL since the deduction
3137 // mechanism handles the partially-substituted argument pack directly.
3138 Deduced.reserve(TemplateParams->size());
3139 for (unsigned I = 0, N = ExplicitArgumentList->size(); I != N; ++I) {
3140 const TemplateArgument &Arg = ExplicitArgumentList->get(I);
3141 if (I == PartiallySubstitutedPackIndex)
3142 Deduced.push_back(DeducedTemplateArgument());
3143 else
3144 Deduced.push_back(Arg);
3145 }
3146
3147 return TDK_Success;
3148}
3149
3150/// Check whether the deduced argument type for a call to a function
3151/// template matches the actual argument type per C++ [temp.deduct.call]p4.
3152static Sema::TemplateDeductionResult
3153CheckOriginalCallArgDeduction(Sema &S, TemplateDeductionInfo &Info,
3154 Sema::OriginalCallArg OriginalArg,
3155 QualType DeducedA) {
3156 ASTContext &Context = S.Context;
3157
3158 auto Failed = [&]() -> Sema::TemplateDeductionResult {
3159 Info.FirstArg = TemplateArgument(DeducedA);
3160 Info.SecondArg = TemplateArgument(OriginalArg.OriginalArgType);
3161 Info.CallArgIndex = OriginalArg.ArgIdx;
3162 return OriginalArg.DecomposedParam ? Sema::TDK_DeducedMismatchNested
3163 : Sema::TDK_DeducedMismatch;
3164 };
3165
3166 QualType A = OriginalArg.OriginalArgType;
3167 QualType OriginalParamType = OriginalArg.OriginalParamType;
3168
3169 // Check for type equality (top-level cv-qualifiers are ignored).
3170 if (Context.hasSameUnqualifiedType(A, DeducedA))
3171 return Sema::TDK_Success;
3172
3173 // Strip off references on the argument types; they aren't needed for
3174 // the following checks.
3175 if (const ReferenceType *DeducedARef = DeducedA->getAs<ReferenceType>())
3176 DeducedA = DeducedARef->getPointeeType();
3177 if (const ReferenceType *ARef = A->getAs<ReferenceType>())
3178 A = ARef->getPointeeType();
3179
3180 // C++ [temp.deduct.call]p4:
3181 // [...] However, there are three cases that allow a difference:
3182 // - If the original P is a reference type, the deduced A (i.e., the
3183 // type referred to by the reference) can be more cv-qualified than
3184 // the transformed A.
3185 if (const ReferenceType *OriginalParamRef
3186 = OriginalParamType->getAs<ReferenceType>()) {
3187 // We don't want to keep the reference around any more.
3188 OriginalParamType = OriginalParamRef->getPointeeType();
3189
3190 // FIXME: Resolve core issue (no number yet): if the original P is a
3191 // reference type and the transformed A is function type "noexcept F",
3192 // the deduced A can be F.
3193 QualType Tmp;
3194 if (A->isFunctionType() && S.IsFunctionConversion(A, DeducedA, Tmp))
3195 return Sema::TDK_Success;
3196
3197 Qualifiers AQuals = A.getQualifiers();
3198 Qualifiers DeducedAQuals = DeducedA.getQualifiers();
3199
3200 // Under Objective-C++ ARC, the deduced type may have implicitly
3201 // been given strong or (when dealing with a const reference)
3202 // unsafe_unretained lifetime. If so, update the original
3203 // qualifiers to include this lifetime.
3204 if (S.getLangOpts().ObjCAutoRefCount &&
3205 ((DeducedAQuals.getObjCLifetime() == Qualifiers::OCL_Strong &&
3206 AQuals.getObjCLifetime() == Qualifiers::OCL_None) ||
3207 (DeducedAQuals.hasConst() &&
3208 DeducedAQuals.getObjCLifetime() == Qualifiers::OCL_ExplicitNone))) {
3209 AQuals.setObjCLifetime(DeducedAQuals.getObjCLifetime());
3210 }
3211
3212 if (AQuals == DeducedAQuals) {
3213 // Qualifiers match; there's nothing to do.
3214 } else if (!DeducedAQuals.compatiblyIncludes(AQuals)) {
3215 return Failed();
3216 } else {
3217 // Qualifiers are compatible, so have the argument type adopt the
3218 // deduced argument type's qualifiers as if we had performed the
3219 // qualification conversion.
3220 A = Context.getQualifiedType(A.getUnqualifiedType(), DeducedAQuals);
3221 }
3222 }
3223
3224 // - The transformed A can be another pointer or pointer to member
3225 // type that can be converted to the deduced A via a function pointer
3226 // conversion and/or a qualification conversion.
3227 //
3228 // Also allow conversions which merely strip __attribute__((noreturn)) from
3229 // function types (recursively).
3230 bool ObjCLifetimeConversion = false;
3231 QualType ResultTy;
3232 if ((A->isAnyPointerType() || A->isMemberPointerType()) &&
3233 (S.IsQualificationConversion(A, DeducedA, false,
3234 ObjCLifetimeConversion) ||
3235 S.IsFunctionConversion(A, DeducedA, ResultTy)))
3236 return Sema::TDK_Success;
3237
3238 // - If P is a class and P has the form simple-template-id, then the
3239 // transformed A can be a derived class of the deduced A. [...]
3240 // [...] Likewise, if P is a pointer to a class of the form
3241 // simple-template-id, the transformed A can be a pointer to a
3242 // derived class pointed to by the deduced A.
3243 if (const PointerType *OriginalParamPtr
3244 = OriginalParamType->getAs<PointerType>()) {
3245 if (const PointerType *DeducedAPtr = DeducedA->getAs<PointerType>()) {
3246 if (const PointerType *APtr = A->getAs<PointerType>()) {
3247 if (A->getPointeeType()->isRecordType()) {
3248 OriginalParamType = OriginalParamPtr->getPointeeType();
3249 DeducedA = DeducedAPtr->getPointeeType();
3250 A = APtr->getPointeeType();
3251 }
3252 }
3253 }
3254 }
3255
3256 if (Context.hasSameUnqualifiedType(A, DeducedA))
3257 return Sema::TDK_Success;
3258
3259 if (A->isRecordType() && isSimpleTemplateIdType(OriginalParamType) &&
3260 S.IsDerivedFrom(Info.getLocation(), A, DeducedA))
3261 return Sema::TDK_Success;
3262
3263 return Failed();
3264}
3265
3266/// Find the pack index for a particular parameter index in an instantiation of
3267/// a function template with specific arguments.
3268///
3269/// \return The pack index for whichever pack produced this parameter, or -1
3270/// if this was not produced by a parameter. Intended to be used as the
3271/// ArgumentPackSubstitutionIndex for further substitutions.
3272// FIXME: We should track this in OriginalCallArgs so we don't need to
3273// reconstruct it here.
3274static unsigned getPackIndexForParam(Sema &S,
3275 FunctionTemplateDecl *FunctionTemplate,
3276 const MultiLevelTemplateArgumentList &Args,
3277 unsigned ParamIdx) {
3278 unsigned Idx = 0;
3279 for (auto *PD : FunctionTemplate->getTemplatedDecl()->parameters()) {
3280 if (PD->isParameterPack()) {
3281 unsigned NumExpansions =
3282 S.getNumArgumentsInExpansion(PD->getType(), Args).getValueOr(1);
3283 if (Idx + NumExpansions > ParamIdx)
3284 return ParamIdx - Idx;
3285 Idx += NumExpansions;
3286 } else {
3287 if (Idx == ParamIdx)
3288 return -1; // Not a pack expansion
3289 ++Idx;
3290 }
3291 }
3292
3293 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-8~svn345461/tools/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 3293)
;
3294}
3295
3296/// Finish template argument deduction for a function template,
3297/// checking the deduced template arguments for completeness and forming
3298/// the function template specialization.
3299///
3300/// \param OriginalCallArgs If non-NULL, the original call arguments against
3301/// which the deduced argument types should be compared.
3302Sema::TemplateDeductionResult Sema::FinishTemplateArgumentDeduction(
3303 FunctionTemplateDecl *FunctionTemplate,
3304 SmallVectorImpl<DeducedTemplateArgument> &Deduced,
3305 unsigned NumExplicitlySpecified, FunctionDecl *&Specialization,
3306 TemplateDeductionInfo &Info,
3307 SmallVectorImpl<OriginalCallArg> const *OriginalCallArgs,
3308 bool PartialOverloading, llvm::function_ref<bool()> CheckNonDependent) {
3309 // Unevaluated SFINAE context.
3310 EnterExpressionEvaluationContext Unevaluated(
3311 *this, Sema::ExpressionEvaluationContext::Unevaluated);
3312 SFINAETrap Trap(*this);
3313
3314 // Enter a new template instantiation context while we instantiate the
3315 // actual function declaration.
3316 SmallVector<TemplateArgument, 4> DeducedArgs(Deduced.begin(), Deduced.end());
3317 InstantiatingTemplate Inst(
3318 *this, Info.getLocation(), FunctionTemplate, DeducedArgs,
3319 CodeSynthesisContext::DeducedTemplateArgumentSubstitution, Info);
3320 if (Inst.isInvalid())
3321 return TDK_InstantiationDepth;
3322
3323 ContextRAII SavedContext(*this, FunctionTemplate->getTemplatedDecl());
3324
3325 // C++ [temp.deduct.type]p2:
3326 // [...] or if any template argument remains neither deduced nor
3327 // explicitly specified, template argument deduction fails.
3328 SmallVector<TemplateArgument, 4> Builder;
3329 if (auto Result = ConvertDeducedTemplateArguments(
3330 *this, FunctionTemplate, /*IsDeduced*/true, Deduced, Info, Builder,
3331 CurrentInstantiationScope, NumExplicitlySpecified,
3332 PartialOverloading))
3333 return Result;
3334
3335 // C++ [temp.deduct.call]p10: [DR1391]
3336 // If deduction succeeds for all parameters that contain
3337 // template-parameters that participate in template argument deduction,
3338 // and all template arguments are explicitly specified, deduced, or
3339 // obtained from default template arguments, remaining parameters are then
3340 // compared with the corresponding arguments. For each remaining parameter
3341 // P with a type that was non-dependent before substitution of any
3342 // explicitly-specified template arguments, if the corresponding argument
3343 // A cannot be implicitly converted to P, deduction fails.
3344 if (CheckNonDependent())
3345 return TDK_NonDependentConversionFailure;
3346
3347 // Form the template argument list from the deduced template arguments.
3348 TemplateArgumentList *DeducedArgumentList
3349 = TemplateArgumentList::CreateCopy(Context, Builder);
3350 Info.reset(DeducedArgumentList);
3351
3352 // Substitute the deduced template arguments into the function template
3353 // declaration to produce the function template specialization.
3354 DeclContext *Owner = FunctionTemplate->getDeclContext();
3355 if (FunctionTemplate->getFriendObjectKind())
3356 Owner = FunctionTemplate->getLexicalDeclContext();
3357 MultiLevelTemplateArgumentList SubstArgs(*DeducedArgumentList);
3358 Specialization = cast_or_null<FunctionDecl>(
3359 SubstDecl(FunctionTemplate->getTemplatedDecl(), Owner, SubstArgs));
3360 if (!Specialization || Specialization->isInvalidDecl())
3361 return TDK_SubstitutionFailure;
3362
3363 assert(Specialization->getPrimaryTemplate()->getCanonicalDecl() ==((Specialization->getPrimaryTemplate()->getCanonicalDecl
() == FunctionTemplate->getCanonicalDecl()) ? static_cast<
void> (0) : __assert_fail ("Specialization->getPrimaryTemplate()->getCanonicalDecl() == FunctionTemplate->getCanonicalDecl()"
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 3364, __PRETTY_FUNCTION__))
3364 FunctionTemplate->getCanonicalDecl())((Specialization->getPrimaryTemplate()->getCanonicalDecl
() == FunctionTemplate->getCanonicalDecl()) ? static_cast<
void> (0) : __assert_fail ("Specialization->getPrimaryTemplate()->getCanonicalDecl() == FunctionTemplate->getCanonicalDecl()"
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 3364, __PRETTY_FUNCTION__))
;
3365
3366 // If the template argument list is owned by the function template
3367 // specialization, release it.
3368 if (Specialization->getTemplateSpecializationArgs() == DeducedArgumentList &&
3369 !Trap.hasErrorOccurred())
3370 Info.take();
3371
3372 // There may have been an error that did not prevent us from constructing a
3373 // declaration. Mark the declaration invalid and return with a substitution
3374 // failure.
3375 if (Trap.hasErrorOccurred()) {
3376 Specialization->setInvalidDecl(true);
3377 return TDK_SubstitutionFailure;
3378 }
3379
3380 if (OriginalCallArgs) {
3381 // C++ [temp.deduct.call]p4:
3382 // In general, the deduction process attempts to find template argument
3383 // values that will make the deduced A identical to A (after the type A
3384 // is transformed as described above). [...]
3385 llvm::SmallDenseMap<std::pair<unsigned, QualType>, QualType> DeducedATypes;
3386 for (unsigned I = 0, N = OriginalCallArgs->size(); I != N; ++I) {
3387 OriginalCallArg OriginalArg = (*OriginalCallArgs)[I];
3388
3389 auto ParamIdx = OriginalArg.ArgIdx;
3390 if (ParamIdx >= Specialization->getNumParams())
3391 // FIXME: This presumably means a pack ended up smaller than we
3392 // expected while deducing. Should this not result in deduction
3393 // failure? Can it even happen?
3394 continue;
3395
3396 QualType DeducedA;
3397 if (!OriginalArg.DecomposedParam) {
3398 // P is one of the function parameters, just look up its substituted
3399 // type.
3400 DeducedA = Specialization->getParamDecl(ParamIdx)->getType();
3401 } else {
3402 // P is a decomposed element of a parameter corresponding to a
3403 // braced-init-list argument. Substitute back into P to find the
3404 // deduced A.
3405 QualType &CacheEntry =
3406 DeducedATypes[{ParamIdx, OriginalArg.OriginalParamType}];
3407 if (CacheEntry.isNull()) {
3408 ArgumentPackSubstitutionIndexRAII PackIndex(
3409 *this, getPackIndexForParam(*this, FunctionTemplate, SubstArgs,
3410 ParamIdx));
3411 CacheEntry =
3412 SubstType(OriginalArg.OriginalParamType, SubstArgs,
3413 Specialization->getTypeSpecStartLoc(),
3414 Specialization->getDeclName());
3415 }
3416 DeducedA = CacheEntry;
3417 }
3418
3419 if (auto TDK =
3420 CheckOriginalCallArgDeduction(*this, Info, OriginalArg, DeducedA))
3421 return TDK;
3422 }
3423 }
3424
3425 // If we suppressed any diagnostics while performing template argument
3426 // deduction, and if we haven't already instantiated this declaration,
3427 // keep track of these diagnostics. They'll be emitted if this specialization
3428 // is actually used.
3429 if (Info.diag_begin() != Info.diag_end()) {
3430 SuppressedDiagnosticsMap::iterator
3431 Pos = SuppressedDiagnostics.find(Specialization->getCanonicalDecl());
3432 if (Pos == SuppressedDiagnostics.end())
3433 SuppressedDiagnostics[Specialization->getCanonicalDecl()]
3434 .append(Info.diag_begin(), Info.diag_end());
3435 }
3436
3437 return TDK_Success;
3438}
3439
3440/// Gets the type of a function for template-argument-deducton
3441/// purposes when it's considered as part of an overload set.
3442static QualType GetTypeOfFunction(Sema &S, const OverloadExpr::FindResult &R,
3443 FunctionDecl *Fn) {
3444 // We may need to deduce the return type of the function now.
3445 if (S.getLangOpts().CPlusPlus14 && Fn->getReturnType()->isUndeducedType() &&
3446 S.DeduceReturnType(Fn, R.Expression->getExprLoc(), /*Diagnose*/ false))
3447 return {};
3448
3449 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn))
3450 if (Method->isInstance()) {
3451 // An instance method that's referenced in a form that doesn't
3452 // look like a member pointer is just invalid.
3453 if (!R.HasFormOfMemberPointer)
3454 return {};
3455
3456 return S.Context.getMemberPointerType(Fn->getType(),
3457 S.Context.getTypeDeclType(Method->getParent()).getTypePtr());
3458 }
3459
3460 if (!R.IsAddressOfOperand) return Fn->getType();
3461 return S.Context.getPointerType(Fn->getType());
3462}
3463
3464/// Apply the deduction rules for overload sets.
3465///
3466/// \return the null type if this argument should be treated as an
3467/// undeduced context
3468static QualType
3469ResolveOverloadForDeduction(Sema &S, TemplateParameterList *TemplateParams,
3470 Expr *Arg, QualType ParamType,
3471 bool ParamWasReference) {
3472
3473 OverloadExpr::FindResult R = OverloadExpr::find(Arg);
3474
3475 OverloadExpr *Ovl = R.Expression;
3476
3477 // C++0x [temp.deduct.call]p4
3478 unsigned TDF = 0;
3479 if (ParamWasReference)
3480 TDF |= TDF_ParamWithReferenceType;
3481 if (R.IsAddressOfOperand)
3482 TDF |= TDF_IgnoreQualifiers;
3483
3484 // C++0x [temp.deduct.call]p6:
3485 // When P is a function type, pointer to function type, or pointer
3486 // to member function type:
3487
3488 if (!ParamType->isFunctionType() &&
3489 !ParamType->isFunctionPointerType() &&
3490 !ParamType->isMemberFunctionPointerType()) {
3491 if (Ovl->hasExplicitTemplateArgs()) {
3492 // But we can still look for an explicit specialization.
3493 if (FunctionDecl *ExplicitSpec
3494 = S.ResolveSingleFunctionTemplateSpecialization(Ovl))
3495 return GetTypeOfFunction(S, R, ExplicitSpec);
3496 }
3497
3498 DeclAccessPair DAP;
3499 if (FunctionDecl *Viable =
3500 S.resolveAddressOfOnlyViableOverloadCandidate(Arg, DAP))
3501 return GetTypeOfFunction(S, R, Viable);
3502
3503 return {};
3504 }
3505
3506 // Gather the explicit template arguments, if any.
3507 TemplateArgumentListInfo ExplicitTemplateArgs;
3508 if (Ovl->hasExplicitTemplateArgs())
3509 Ovl->copyTemplateArgumentsInto(ExplicitTemplateArgs);
3510 QualType Match;
3511 for (UnresolvedSetIterator I = Ovl->decls_begin(),
3512 E = Ovl->decls_end(); I != E; ++I) {
3513 NamedDecl *D = (*I)->getUnderlyingDecl();
3514
3515 if (FunctionTemplateDecl *FunTmpl = dyn_cast<FunctionTemplateDecl>(D)) {
3516 // - If the argument is an overload set containing one or more
3517 // function templates, the parameter is treated as a
3518 // non-deduced context.
3519 if (!Ovl->hasExplicitTemplateArgs())
3520 return {};
3521
3522 // Otherwise, see if we can resolve a function type
3523 FunctionDecl *Specialization = nullptr;
3524 TemplateDeductionInfo Info(Ovl->getNameLoc());
3525 if (S.DeduceTemplateArguments(FunTmpl, &ExplicitTemplateArgs,
3526 Specialization, Info))
3527 continue;
3528
3529 D = Specialization;
3530 }
3531
3532 FunctionDecl *Fn = cast<FunctionDecl>(D);
3533 QualType ArgType = GetTypeOfFunction(S, R, Fn);
3534 if (ArgType.isNull()) continue;
3535
3536 // Function-to-pointer conversion.
3537 if (!ParamWasReference && ParamType->isPointerType() &&
3538 ArgType->isFunctionType())
3539 ArgType = S.Context.getPointerType(ArgType);
3540
3541 // - If the argument is an overload set (not containing function
3542 // templates), trial argument deduction is attempted using each
3543 // of the members of the set. If deduction succeeds for only one
3544 // of the overload set members, that member is used as the
3545 // argument value for the deduction. If deduction succeeds for
3546 // more than one member of the overload set the parameter is
3547 // treated as a non-deduced context.
3548
3549 // We do all of this in a fresh context per C++0x [temp.deduct.type]p2:
3550 // Type deduction is done independently for each P/A pair, and
3551 // the deduced template argument values are then combined.
3552 // So we do not reject deductions which were made elsewhere.
3553 SmallVector<DeducedTemplateArgument, 8>
3554 Deduced(TemplateParams->size());
3555 TemplateDeductionInfo Info(Ovl->getNameLoc());
3556 Sema::TemplateDeductionResult Result
3557 = DeduceTemplateArgumentsByTypeMatch(S, TemplateParams, ParamType,
3558 ArgType, Info, Deduced, TDF);
3559 if (Result) continue;
3560 if (!Match.isNull())
3561 return {};
3562 Match = ArgType;
3563 }
3564
3565 return Match;
3566}
3567
3568/// Perform the adjustments to the parameter and argument types
3569/// described in C++ [temp.deduct.call].
3570///
3571/// \returns true if the caller should not attempt to perform any template
3572/// argument deduction based on this P/A pair because the argument is an
3573/// overloaded function set that could not be resolved.
3574static bool AdjustFunctionParmAndArgTypesForDeduction(
3575 Sema &S, TemplateParameterList *TemplateParams, unsigned FirstInnerIndex,
3576 QualType &ParamType, QualType &ArgType, Expr *Arg, unsigned &TDF) {
3577 // C++0x [temp.deduct.call]p3:
3578 // If P is a cv-qualified type, the top level cv-qualifiers of P's type
3579 // are ignored for type deduction.
3580 if (ParamType.hasQualifiers())
3581 ParamType = ParamType.getUnqualifiedType();
3582
3583 // [...] If P is a reference type, the type referred to by P is
3584 // used for type deduction.
3585 const ReferenceType *ParamRefType = ParamType->getAs<ReferenceType>();
3586 if (ParamRefType)
3587 ParamType = ParamRefType->getPointeeType();
3588
3589 // Overload sets usually make this parameter an undeduced context,
3590 // but there are sometimes special circumstances. Typically
3591 // involving a template-id-expr.
3592 if (ArgType == S.Context.OverloadTy) {
3593 ArgType = ResolveOverloadForDeduction(S, TemplateParams,
3594 Arg, ParamType,
3595 ParamRefType != nullptr);
3596 if (ArgType.isNull())
3597 return true;
3598 }
3599
3600 if (ParamRefType) {
3601 // If the argument has incomplete array type, try to complete its type.
3602 if (ArgType->isIncompleteArrayType()) {
3603 S.completeExprArrayBound(Arg);
3604 ArgType = Arg->getType();
3605 }
3606
3607 // C++1z [temp.deduct.call]p3:
3608 // If P is a forwarding reference and the argument is an lvalue, the type
3609 // "lvalue reference to A" is used in place of A for type deduction.
3610 if (isForwardingReference(QualType(ParamRefType, 0), FirstInnerIndex) &&
3611 Arg->isLValue())
3612 ArgType = S.Context.getLValueReferenceType(ArgType);
3613 } else {
3614 // C++ [temp.deduct.call]p2:
3615 // If P is not a reference type:
3616 // - If A is an array type, the pointer type produced by the
3617 // array-to-pointer standard conversion (4.2) is used in place of
3618 // A for type deduction; otherwise,
3619 if (ArgType->isArrayType())
3620 ArgType = S.Context.getArrayDecayedType(ArgType);
3621 // - If A is a function type, the pointer type produced by the
3622 // function-to-pointer standard conversion (4.3) is used in place
3623 // of A for type deduction; otherwise,
3624 else if (ArgType->isFunctionType())
3625 ArgType = S.Context.getPointerType(ArgType);
3626 else {
3627 // - If A is a cv-qualified type, the top level cv-qualifiers of A's
3628 // type are ignored for type deduction.
3629 ArgType = ArgType.getUnqualifiedType();
3630 }
3631 }
3632
3633 // C++0x [temp.deduct.call]p4:
3634 // In general, the deduction process attempts to find template argument
3635 // values that will make the deduced A identical to A (after the type A
3636 // is transformed as described above). [...]
3637 TDF = TDF_SkipNonDependent;
3638
3639 // - If the original P is a reference type, the deduced A (i.e., the
3640 // type referred to by the reference) can be more cv-qualified than
3641 // the transformed A.
3642 if (ParamRefType)
3643 TDF |= TDF_ParamWithReferenceType;
3644 // - The transformed A can be another pointer or pointer to member
3645 // type that can be converted to the deduced A via a qualification
3646 // conversion (4.4).
3647 if (ArgType->isPointerType() || ArgType->isMemberPointerType() ||
3648 ArgType->isObjCObjectPointerType())
3649 TDF |= TDF_IgnoreQualifiers;
3650 // - If P is a class and P has the form simple-template-id, then the
3651 // transformed A can be a derived class of the deduced A. Likewise,
3652 // if P is a pointer to a class of the form simple-template-id, the
3653 // transformed A can be a pointer to a derived class pointed to by
3654 // the deduced A.
3655 if (isSimpleTemplateIdType(ParamType) ||
3656 (isa<PointerType>(ParamType) &&
3657 isSimpleTemplateIdType(
3658 ParamType->getAs<PointerType>()->getPointeeType())))
3659 TDF |= TDF_DerivedClass;
3660
3661 return false;
3662}
3663
3664static bool
3665hasDeducibleTemplateParameters(Sema &S, FunctionTemplateDecl *FunctionTemplate,
3666 QualType T);
3667
3668static Sema::TemplateDeductionResult DeduceTemplateArgumentsFromCallArgument(
3669 Sema &S, TemplateParameterList *TemplateParams, unsigned FirstInnerIndex,
3670 QualType ParamType, Expr *Arg, TemplateDeductionInfo &Info,
3671 SmallVectorImpl<DeducedTemplateArgument> &Deduced,
3672 SmallVectorImpl<Sema::OriginalCallArg> &OriginalCallArgs,
3673 bool DecomposedParam, unsigned ArgIdx, unsigned TDF);
3674
3675/// Attempt template argument deduction from an initializer list
3676/// deemed to be an argument in a function call.
3677static Sema::TemplateDeductionResult DeduceFromInitializerList(
3678 Sema &S, TemplateParameterList *TemplateParams, QualType AdjustedParamType,
3679 InitListExpr *ILE, TemplateDeductionInfo &Info,
3680 SmallVectorImpl<DeducedTemplateArgument> &Deduced,
3681 SmallVectorImpl<Sema::OriginalCallArg> &OriginalCallArgs, unsigned ArgIdx,
3682 unsigned TDF) {
3683 // C++ [temp.deduct.call]p1: (CWG 1591)
3684 // If removing references and cv-qualifiers from P gives
3685 // std::initializer_list<P0> or P0[N] for some P0 and N and the argument is
3686 // a non-empty initializer list, then deduction is performed instead for
3687 // each element of the initializer list, taking P0 as a function template
3688 // parameter type and the initializer element as its argument
3689 //
3690 // We've already removed references and cv-qualifiers here.
3691 if (!ILE->getNumInits())
3692 return Sema::TDK_Success;
3693
3694 QualType ElTy;
3695 auto *ArrTy = S.Context.getAsArrayType(AdjustedParamType);
3696 if (ArrTy)
3697 ElTy = ArrTy->getElementType();
3698 else if (!S.isStdInitializerList(AdjustedParamType, &ElTy)) {
3699 // Otherwise, an initializer list argument causes the parameter to be
3700 // considered a non-deduced context
3701 return Sema::TDK_Success;
3702 }
3703
3704 // Deduction only needs to be done for dependent types.
3705 if (ElTy->isDependentType()) {
3706 for (Expr *E : ILE->inits()) {
3707 if (auto Result = DeduceTemplateArgumentsFromCallArgument(
3708 S, TemplateParams, 0, ElTy, E, Info, Deduced, OriginalCallArgs, true,
3709 ArgIdx, TDF))
3710 return Result;
3711 }
3712 }
3713
3714 // in the P0[N] case, if N is a non-type template parameter, N is deduced
3715 // from the length of the initializer list.
3716 if (auto *DependentArrTy = dyn_cast_or_null<DependentSizedArrayType>(ArrTy)) {
3717 // Determine the array bound is something we can deduce.
3718 if (NonTypeTemplateParmDecl *NTTP =
3719 getDeducedParameterFromExpr(Info, DependentArrTy->getSizeExpr())) {
3720 // We can perform template argument deduction for the given non-type
3721 // template parameter.
3722 // C++ [temp.deduct.type]p13:
3723 // The type of N in the type T[N] is std::size_t.
3724 QualType T = S.Context.getSizeType();
3725 llvm::APInt Size(S.Context.getIntWidth(T), ILE->getNumInits());
3726 if (auto Result = DeduceNonTypeTemplateArgument(
3727 S, TemplateParams, NTTP, llvm::APSInt(Size), T,
3728 /*ArrayBound=*/true, Info, Deduced))
3729 return Result;
3730 }
3731 }
3732
3733 return Sema::TDK_Success;
3734}
3735
3736/// Perform template argument deduction per [temp.deduct.call] for a
3737/// single parameter / argument pair.
3738static Sema::TemplateDeductionResult DeduceTemplateArgumentsFromCallArgument(
3739 Sema &S, TemplateParameterList *TemplateParams, unsigned FirstInnerIndex,
3740 QualType ParamType, Expr *Arg, TemplateDeductionInfo &Info,
3741 SmallVectorImpl<DeducedTemplateArgument> &Deduced,
3742 SmallVectorImpl<Sema::OriginalCallArg> &OriginalCallArgs,
3743 bool DecomposedParam, unsigned ArgIdx, unsigned TDF) {
3744 QualType ArgType = Arg->getType();
3745 QualType OrigParamType = ParamType;
3746
3747 // If P is a reference type [...]
3748 // If P is a cv-qualified type [...]
3749 if (AdjustFunctionParmAndArgTypesForDeduction(
3750 S, TemplateParams, FirstInnerIndex, ParamType, ArgType, Arg, TDF))
3751 return Sema::TDK_Success;
3752
3753 // If [...] the argument is a non-empty initializer list [...]
3754 if (InitListExpr *ILE = dyn_cast<InitListExpr>(Arg))
3755 return DeduceFromInitializerList(S, TemplateParams, ParamType, ILE, Info,
3756 Deduced, OriginalCallArgs, ArgIdx, TDF);
3757
3758 // [...] the deduction process attempts to find template argument values
3759 // that will make the deduced A identical to A
3760 //
3761 // Keep track of the argument type and corresponding parameter index,
3762 // so we can check for compatibility between the deduced A and A.
3763 OriginalCallArgs.push_back(
3764 Sema::OriginalCallArg(OrigParamType, DecomposedParam, ArgIdx, ArgType));
3765 return DeduceTemplateArgumentsByTypeMatch(S, TemplateParams, ParamType,
3766 ArgType, Info, Deduced, TDF);
3767}
3768
3769/// Perform template argument deduction from a function call
3770/// (C++ [temp.deduct.call]).
3771///
3772/// \param FunctionTemplate the function template for which we are performing
3773/// template argument deduction.
3774///
3775/// \param ExplicitTemplateArgs the explicit template arguments provided
3776/// for this call.
3777///
3778/// \param Args the function call arguments
3779///
3780/// \param Specialization if template argument deduction was successful,
3781/// this will be set to the function template specialization produced by
3782/// template argument deduction.
3783///
3784/// \param Info the argument will be updated to provide additional information
3785/// about template argument deduction.
3786///
3787/// \param CheckNonDependent A callback to invoke to check conversions for
3788/// non-dependent parameters, between deduction and substitution, per DR1391.
3789/// If this returns true, substitution will be skipped and we return
3790/// TDK_NonDependentConversionFailure. The callback is passed the parameter
3791/// types (after substituting explicit template arguments).
3792///
3793/// \returns the result of template argument deduction.
3794Sema::TemplateDeductionResult Sema::DeduceTemplateArguments(
3795 FunctionTemplateDecl *FunctionTemplate,
3796 TemplateArgumentListInfo *ExplicitTemplateArgs, ArrayRef<Expr *> Args,
3797 FunctionDecl *&Specialization, TemplateDeductionInfo &Info,
3798 bool PartialOverloading,
3799 llvm::function_ref<bool(ArrayRef<QualType>)> CheckNonDependent) {
3800 if (FunctionTemplate->isInvalidDecl())
1
Assuming the condition is false
2
Taking false branch
3801 return TDK_Invalid;
3802
3803 FunctionDecl *Function = FunctionTemplate->getTemplatedDecl();
3804 unsigned NumParams = Function->getNumParams();
3805
3806 unsigned FirstInnerIndex = getFirstInnerIndex(FunctionTemplate);
3807
3808 // C++ [temp.deduct.call]p1:
3809 // Template argument deduction is done by comparing each function template
3810 // parameter type (call it P) with the type of the corresponding argument
3811 // of the call (call it A) as described below.
3812 if (Args.size() < Function->getMinRequiredArguments() && !PartialOverloading)
3
Assuming the condition is false
3813 return TDK_TooFewArguments;
3814 else if (TooManyArguments(NumParams, Args.size(), PartialOverloading)) {
4
Taking false branch
3815 const FunctionProtoType *Proto
3816 = Function->getType()->getAs<FunctionProtoType>();
3817 if (Proto->isTemplateVariadic())
3818 /* Do nothing */;
3819 else if (!Proto->isVariadic())
3820 return TDK_TooManyArguments;
3821 }
3822
3823 // The types of the parameters from which we will perform template argument
3824 // deduction.
3825 LocalInstantiationScope InstScope(*this);
3826 TemplateParameterList *TemplateParams
3827 = FunctionTemplate->getTemplateParameters();
3828 SmallVector<DeducedTemplateArgument, 4> Deduced;
3829 SmallVector<QualType, 8> ParamTypes;
3830 unsigned NumExplicitlySpecified = 0;
3831 if (ExplicitTemplateArgs) {
5
Assuming 'ExplicitTemplateArgs' is null
6
Taking false branch
3832 TemplateDeductionResult Result =
3833 SubstituteExplicitTemplateArguments(FunctionTemplate,
3834 *ExplicitTemplateArgs,
3835 Deduced,
3836 ParamTypes,
3837 nullptr,
3838 Info);
3839 if (Result)
3840 return Result;
3841
3842 NumExplicitlySpecified = Deduced.size();
3843 } else {
3844 // Just fill in the parameter types from the function declaration.
3845 for (unsigned I = 0; I != NumParams; ++I)
7
Assuming 'I' is equal to 'NumParams'
8
Loop condition is false. Execution continues on line 3849
3846 ParamTypes.push_back(Function->getParamDecl(I)->getType());
3847 }
3848
3849 SmallVector<OriginalCallArg, 8> OriginalCallArgs;
3850
3851 // Deduce an argument of type ParamType from an expression with index ArgIdx.
3852 auto DeduceCallArgument = [&](QualType ParamType, unsigned ArgIdx) {
3853 // C++ [demp.deduct.call]p1: (DR1391)
3854 // Template argument deduction is done by comparing each function template
3855 // parameter that contains template-parameters that participate in
3856 // template argument deduction ...
3857 if (!hasDeducibleTemplateParameters(*this, FunctionTemplate, ParamType))
3858 return Sema::TDK_Success;
3859
3860 // ... with the type of the corresponding argument
3861 return DeduceTemplateArgumentsFromCallArgument(
3862 *this, TemplateParams, FirstInnerIndex, ParamType, Args[ArgIdx], Info, Deduced,
3863 OriginalCallArgs, /*Decomposed*/false, ArgIdx, /*TDF*/ 0);
3864 };
3865
3866 // Deduce template arguments from the function parameters.
3867 Deduced.resize(TemplateParams->size());
3868 SmallVector<QualType, 8> ParamTypesForArgChecking;
3869 for (unsigned ParamIdx = 0, NumParamTypes = ParamTypes.size(), ArgIdx = 0;
10
Loop condition is true. Entering loop body
3870 ParamIdx != NumParamTypes; ++ParamIdx) {
9
Assuming 'ParamIdx' is not equal to 'NumParamTypes'
3871 QualType ParamType = ParamTypes[ParamIdx];
3872
3873 const PackExpansionType *ParamExpansion =
3874 dyn_cast<PackExpansionType>(ParamType);
3875 if (!ParamExpansion) {
11
Assuming 'ParamExpansion' is non-null
12
Taking false branch
3876 // Simple case: matching a function parameter to a function argument.
3877 if (ArgIdx >= Args.size())
3878 break;
3879
3880 ParamTypesForArgChecking.push_back(ParamType);
3881 if (auto Result = DeduceCallArgument(ParamType, ArgIdx++))
3882 return Result;
3883
3884 continue;
3885 }
3886
3887 QualType ParamPattern = ParamExpansion->getPattern();
3888 PackDeductionScope PackScope(*this, TemplateParams, Deduced, Info,
13
Calling constructor for 'PackDeductionScope'
3889 ParamPattern);
3890
3891 // C++0x [temp.deduct.call]p1:
3892 // For a function parameter pack that occurs at the end of the
3893 // parameter-declaration-list, the type A of each remaining argument of
3894 // the call is compared with the type P of the declarator-id of the
3895 // function parameter pack. Each comparison deduces template arguments
3896 // for subsequent positions in the template parameter packs expanded by
3897 // the function parameter pack. When a function parameter pack appears
3898 // in a non-deduced context [not at the end of the list], the type of
3899 // that parameter pack is never deduced.
3900 //
3901 // FIXME: The above rule allows the size of the parameter pack to change
3902 // after we skip it (in the non-deduced case). That makes no sense, so
3903 // we instead notionally deduce the pack against N arguments, where N is
3904 // the length of the explicitly-specified pack if it's expanded by the
3905 // parameter pack and 0 otherwise, and we treat each deduction as a
3906 // non-deduced context.
3907 if (ParamIdx + 1 == NumParamTypes || PackScope.hasFixedArity()) {
3908 for (; ArgIdx < Args.size() && PackScope.hasNextElement();
3909 PackScope.nextPackElement(), ++ArgIdx) {
3910 ParamTypesForArgChecking.push_back(ParamPattern);
3911 if (auto Result = DeduceCallArgument(ParamPattern, ArgIdx))
3912 return Result;
3913 }
3914 } else {
3915 // If the parameter type contains an explicitly-specified pack that we
3916 // could not expand, skip the number of parameters notionally created
3917 // by the expansion.
3918 Optional<unsigned> NumExpansions = ParamExpansion->getNumExpansions();
3919 if (NumExpansions && !PackScope.isPartiallyExpanded()) {
3920 for (unsigned I = 0; I != *NumExpansions && ArgIdx < Args.size();
3921 ++I, ++ArgIdx) {
3922 ParamTypesForArgChecking.push_back(ParamPattern);
3923 // FIXME: Should we add OriginalCallArgs for these? What if the
3924 // corresponding argument is a list?
3925 PackScope.nextPackElement();
3926 }
3927 }
3928 }
3929
3930 // Build argument packs for each of the parameter packs expanded by this
3931 // pack expansion.
3932 if (auto Result = PackScope.finish())
3933 return Result;
3934 }
3935
3936 // Capture the context in which the function call is made. This is the context
3937 // that is needed when the accessibility of template arguments is checked.
3938 DeclContext *CallingCtx = CurContext;
3939
3940 return FinishTemplateArgumentDeduction(
3941 FunctionTemplate, Deduced, NumExplicitlySpecified, Specialization, Info,
3942 &OriginalCallArgs, PartialOverloading, [&, CallingCtx]() {
3943 ContextRAII SavedContext(*this, CallingCtx);
3944 return CheckNonDependent(ParamTypesForArgChecking);
3945 });
3946}
3947
3948QualType Sema::adjustCCAndNoReturn(QualType ArgFunctionType,
3949 QualType FunctionType,
3950 bool AdjustExceptionSpec) {
3951 if (ArgFunctionType.isNull())
3952 return ArgFunctionType;
3953
3954 const FunctionProtoType *FunctionTypeP =
3955 FunctionType->castAs<FunctionProtoType>();
3956 const FunctionProtoType *ArgFunctionTypeP =
3957 ArgFunctionType->getAs<FunctionProtoType>();
3958
3959 FunctionProtoType::ExtProtoInfo EPI = ArgFunctionTypeP->getExtProtoInfo();
3960 bool Rebuild = false;
3961
3962 CallingConv CC = FunctionTypeP->getCallConv();
3963 if (EPI.ExtInfo.getCC() != CC) {
3964 EPI.ExtInfo = EPI.ExtInfo.withCallingConv(CC);
3965 Rebuild = true;
3966 }
3967
3968 bool NoReturn = FunctionTypeP->getNoReturnAttr();
3969 if (EPI.ExtInfo.getNoReturn() != NoReturn) {
3970 EPI.ExtInfo = EPI.ExtInfo.withNoReturn(NoReturn);
3971 Rebuild = true;
3972 }
3973
3974 if (AdjustExceptionSpec && (FunctionTypeP->hasExceptionSpec() ||
3975 ArgFunctionTypeP->hasExceptionSpec())) {
3976 EPI.ExceptionSpec = FunctionTypeP->getExtProtoInfo().ExceptionSpec;
3977 Rebuild = true;
3978 }
3979
3980 if (!Rebuild)
3981 return ArgFunctionType;
3982
3983 return Context.getFunctionType(ArgFunctionTypeP->getReturnType(),
3984 ArgFunctionTypeP->getParamTypes(), EPI);
3985}
3986
3987/// Deduce template arguments when taking the address of a function
3988/// template (C++ [temp.deduct.funcaddr]) or matching a specialization to
3989/// a template.
3990///
3991/// \param FunctionTemplate the function template for which we are performing
3992/// template argument deduction.
3993///
3994/// \param ExplicitTemplateArgs the explicitly-specified template
3995/// arguments.
3996///
3997/// \param ArgFunctionType the function type that will be used as the
3998/// "argument" type (A) when performing template argument deduction from the
3999/// function template's function type. This type may be NULL, if there is no
4000/// argument type to compare against, in C++0x [temp.arg.explicit]p3.
4001///
4002/// \param Specialization if template argument deduction was successful,
4003/// this will be set to the function template specialization produced by
4004/// template argument deduction.
4005///
4006/// \param Info the argument will be updated to provide additional information
4007/// about template argument deduction.
4008///
4009/// \param IsAddressOfFunction If \c true, we are deducing as part of taking
4010/// the address of a function template per [temp.deduct.funcaddr] and
4011/// [over.over]. If \c false, we are looking up a function template
4012/// specialization based on its signature, per [temp.deduct.decl].
4013///
4014/// \returns the result of template argument deduction.
4015Sema::TemplateDeductionResult Sema::DeduceTemplateArguments(
4016 FunctionTemplateDecl *FunctionTemplate,
4017 TemplateArgumentListInfo *ExplicitTemplateArgs, QualType ArgFunctionType,
4018 FunctionDecl *&Specialization, TemplateDeductionInfo &Info,
4019 bool IsAddressOfFunction) {
4020 if (FunctionTemplate->isInvalidDecl())
4021 return TDK_Invalid;
4022
4023 FunctionDecl *Function = FunctionTemplate->getTemplatedDecl();
4024 TemplateParameterList *TemplateParams
4025 = FunctionTemplate->getTemplateParameters();
4026 QualType FunctionType = Function->getType();
4027
4028 // Substitute any explicit template arguments.
4029 LocalInstantiationScope InstScope(*this);
4030 SmallVector<DeducedTemplateArgument, 4> Deduced;
4031 unsigned NumExplicitlySpecified = 0;
4032 SmallVector<QualType, 4> ParamTypes;
4033 if (ExplicitTemplateArgs) {
4034 if (TemplateDeductionResult Result
4035 = SubstituteExplicitTemplateArguments(FunctionTemplate,
4036 *ExplicitTemplateArgs,
4037 Deduced, ParamTypes,
4038 &FunctionType, Info))
4039 return Result;
4040
4041 NumExplicitlySpecified = Deduced.size();
4042 }
4043
4044 // When taking the address of a function, we require convertibility of
4045 // the resulting function type. Otherwise, we allow arbitrary mismatches
4046 // of calling convention and noreturn.
4047 if (!IsAddressOfFunction)
4048 ArgFunctionType = adjustCCAndNoReturn(ArgFunctionType, FunctionType,
4049 /*AdjustExceptionSpec*/false);
4050
4051 // Unevaluated SFINAE context.
4052 EnterExpressionEvaluationContext Unevaluated(
4053 *this, Sema::ExpressionEvaluationContext::Unevaluated);
4054 SFINAETrap Trap(*this);
4055
4056 Deduced.resize(TemplateParams->size());
4057
4058 // If the function has a deduced return type, substitute it for a dependent
4059 // type so that we treat it as a non-deduced context in what follows. If we
4060 // are looking up by signature, the signature type should also have a deduced
4061 // return type, which we instead expect to exactly match.
4062 bool HasDeducedReturnType = false;
4063 if (getLangOpts().CPlusPlus14 && IsAddressOfFunction &&
4064 Function->getReturnType()->getContainedAutoType()) {
4065 FunctionType = SubstAutoType(FunctionType, Context.DependentTy);
4066 HasDeducedReturnType = true;
4067 }
4068
4069 if (!ArgFunctionType.isNull()) {
4070 unsigned TDF =
4071 TDF_TopLevelParameterTypeList | TDF_AllowCompatibleFunctionType;
4072 // Deduce template arguments from the function type.
4073 if (TemplateDeductionResult Result
4074 = DeduceTemplateArgumentsByTypeMatch(*this, TemplateParams,
4075 FunctionType, ArgFunctionType,
4076 Info, Deduced, TDF))
4077 return Result;
4078 }
4079
4080 if (TemplateDeductionResult Result
4081 = FinishTemplateArgumentDeduction(FunctionTemplate, Deduced,
4082 NumExplicitlySpecified,
4083 Specialization, Info))
4084 return Result;
4085
4086 // If the function has a deduced return type, deduce it now, so we can check
4087 // that the deduced function type matches the requested type.
4088 if (HasDeducedReturnType &&
4089 Specialization->getReturnType()->isUndeducedType() &&
4090 DeduceReturnType(Specialization, Info.getLocation(), false))
4091 return TDK_MiscellaneousDeductionFailure;
4092
4093 // If the function has a dependent exception specification, resolve it now,
4094 // so we can check that the exception specification matches.
4095 auto *SpecializationFPT =
4096 Specialization->getType()->castAs<FunctionProtoType>();
4097 if (getLangOpts().CPlusPlus17 &&
4098 isUnresolvedExceptionSpec(SpecializationFPT->getExceptionSpecType()) &&
4099 !ResolveExceptionSpec(Info.getLocation(), SpecializationFPT))
4100 return TDK_MiscellaneousDeductionFailure;
4101
4102 // Adjust the exception specification of the argument to match the
4103 // substituted and resolved type we just formed. (Calling convention and
4104 // noreturn can't be dependent, so we don't actually need this for them
4105 // right now.)
4106 QualType SpecializationType = Specialization->getType();
4107 if (!IsAddressOfFunction)
4108 ArgFunctionType = adjustCCAndNoReturn(ArgFunctionType, SpecializationType,
4109 /*AdjustExceptionSpec*/true);
4110
4111 // If the requested function type does not match the actual type of the
4112 // specialization with respect to arguments of compatible pointer to function
4113 // types, template argument deduction fails.
4114 if (!ArgFunctionType.isNull()) {
4115 if (IsAddressOfFunction &&
4116 !isSameOrCompatibleFunctionType(
4117 Context.getCanonicalType(SpecializationType),
4118 Context.getCanonicalType(ArgFunctionType)))
4119 return TDK_MiscellaneousDeductionFailure;
4120
4121 if (!IsAddressOfFunction &&
4122 !Context.hasSameType(SpecializationType, ArgFunctionType))
4123 return TDK_MiscellaneousDeductionFailure;
4124 }
4125
4126 return TDK_Success;
4127}
4128
4129/// Deduce template arguments for a templated conversion
4130/// function (C++ [temp.deduct.conv]) and, if successful, produce a
4131/// conversion function template specialization.
4132Sema::TemplateDeductionResult
4133Sema::DeduceTemplateArguments(FunctionTemplateDecl *ConversionTemplate,
4134 QualType ToType,
4135 CXXConversionDecl *&Specialization,
4136 TemplateDeductionInfo &Info) {
4137 if (ConversionTemplate->isInvalidDecl())
4138 return TDK_Invalid;
4139
4140 CXXConversionDecl *ConversionGeneric
4141 = cast<CXXConversionDecl>(ConversionTemplate->getTemplatedDecl());
4142
4143 QualType FromType = ConversionGeneric->getConversionType();
4144
4145 // Canonicalize the types for deduction.
4146 QualType P = Context.getCanonicalType(FromType);
4147 QualType A = Context.getCanonicalType(ToType);
4148
4149 // C++0x [temp.deduct.conv]p2:
4150 // If P is a reference type, the type referred to by P is used for
4151 // type deduction.
4152 if (const ReferenceType *PRef = P->getAs<ReferenceType>())
4153 P = PRef->getPointeeType();
4154
4155 // C++0x [temp.deduct.conv]p4:
4156 // [...] If A is a reference type, the type referred to by A is used
4157 // for type deduction.
4158 if (const ReferenceType *ARef = A->getAs<ReferenceType>()) {
4159 A = ARef->getPointeeType();
4160 // We work around a defect in the standard here: cv-qualifiers are also
4161 // removed from P and A in this case, unless P was a reference type. This
4162 // seems to mostly match what other compilers are doing.
4163 if (!FromType->getAs<ReferenceType>()) {
4164 A = A.getUnqualifiedType();
4165 P = P.getUnqualifiedType();
4166 }
4167
4168 // C++ [temp.deduct.conv]p3:
4169 //
4170 // If A is not a reference type:
4171 } else {
4172 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-8~svn345461/tools/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 4172, __PRETTY_FUNCTION__))
;
4173
4174 // - If P is an array type, the pointer type produced by the
4175 // array-to-pointer standard conversion (4.2) is used in place
4176 // of P for type deduction; otherwise,
4177 if (P->isArrayType())
4178 P = Context.getArrayDecayedType(P);
4179 // - If P is a function type, the pointer type produced by the
4180 // function-to-pointer standard conversion (4.3) is used in
4181 // place of P for type deduction; otherwise,
4182 else if (P->isFunctionType())
4183 P = Context.getPointerType(P);
4184 // - If P is a cv-qualified type, the top level cv-qualifiers of
4185 // P's type are ignored for type deduction.
4186 else
4187 P = P.getUnqualifiedType();
4188
4189 // C++0x [temp.deduct.conv]p4:
4190 // If A is a cv-qualified type, the top level cv-qualifiers of A's
4191 // type are ignored for type deduction. If A is a reference type, the type
4192 // referred to by A is used for type deduction.
4193 A = A.getUnqualifiedType();
4194 }
4195
4196 // Unevaluated SFINAE context.
4197 EnterExpressionEvaluationContext Unevaluated(
4198 *this, Sema::ExpressionEvaluationContext::Unevaluated);
4199 SFINAETrap Trap(*this);
4200
4201 // C++ [temp.deduct.conv]p1:
4202 // Template argument deduction is done by comparing the return
4203 // type of the template conversion function (call it P) with the
4204 // type that is required as the result of the conversion (call it
4205 // A) as described in 14.8.2.4.
4206 TemplateParameterList *TemplateParams
4207 = ConversionTemplate->getTemplateParameters();
4208 SmallVector<DeducedTemplateArgument, 4> Deduced;
4209 Deduced.resize(TemplateParams->size());
4210
4211 // C++0x [temp.deduct.conv]p4:
4212 // In general, the deduction process attempts to find template
4213 // argument values that will make the deduced A identical to
4214 // A. However, there are two cases that allow a difference:
4215 unsigned TDF = 0;
4216 // - If the original A is a reference type, A can be more
4217 // cv-qualified than the deduced A (i.e., the type referred to
4218 // by the reference)
4219 if (ToType->isReferenceType())
4220 TDF |= TDF_ArgWithReferenceType;
4221 // - The deduced A can be another pointer or pointer to member
4222 // type that can be converted to A via a qualification
4223 // conversion.
4224 //
4225 // (C++0x [temp.deduct.conv]p6 clarifies that this only happens when
4226 // both P and A are pointers or member pointers. In this case, we
4227 // just ignore cv-qualifiers completely).
4228 if ((P->isPointerType() && A->isPointerType()) ||
4229 (P->isMemberPointerType() && A->isMemberPointerType()))
4230 TDF |= TDF_IgnoreQualifiers;
4231 if (TemplateDeductionResult Result
4232 = DeduceTemplateArgumentsByTypeMatch(*this, TemplateParams,
4233 P, A, Info, Deduced, TDF))
4234 return Result;
4235
4236 // Create an Instantiation Scope for finalizing the operator.
4237 LocalInstantiationScope InstScope(*this);
4238 // Finish template argument deduction.
4239 FunctionDecl *ConversionSpecialized = nullptr;
4240 TemplateDeductionResult Result
4241 = FinishTemplateArgumentDeduction(ConversionTemplate, Deduced, 0,
4242 ConversionSpecialized, Info);
4243 Specialization = cast_or_null<CXXConversionDecl>(ConversionSpecialized);
4244 return Result;
4245}
4246
4247/// Deduce template arguments for a function template when there is
4248/// nothing to deduce against (C++0x [temp.arg.explicit]p3).
4249///
4250/// \param FunctionTemplate the function template for which we are performing
4251/// template argument deduction.
4252///
4253/// \param ExplicitTemplateArgs the explicitly-specified template
4254/// arguments.
4255///
4256/// \param Specialization if template argument deduction was successful,
4257/// this will be set to the function template specialization produced by
4258/// template argument deduction.
4259///
4260/// \param Info the argument will be updated to provide additional information
4261/// about template argument deduction.
4262///
4263/// \param IsAddressOfFunction If \c true, we are deducing as part of taking
4264/// the address of a function template in a context where we do not have a
4265/// target type, per [over.over]. If \c false, we are looking up a function
4266/// template specialization based on its signature, which only happens when
4267/// deducing a function parameter type from an argument that is a template-id
4268/// naming a function template specialization.
4269///
4270/// \returns the result of template argument deduction.
4271Sema::TemplateDeductionResult Sema::DeduceTemplateArguments(
4272 FunctionTemplateDecl *FunctionTemplate,
4273 TemplateArgumentListInfo *ExplicitTemplateArgs,
4274 FunctionDecl *&Specialization, TemplateDeductionInfo &Info,
4275 bool IsAddressOfFunction) {
4276 return DeduceTemplateArguments(FunctionTemplate, ExplicitTemplateArgs,
4277 QualType(), Specialization, Info,
4278 IsAddressOfFunction);
4279}
4280
4281namespace {
4282
4283 /// Substitute the 'auto' specifier or deduced template specialization type
4284 /// specifier within a type for a given replacement type.
4285 class SubstituteDeducedTypeTransform :
4286 public TreeTransform<SubstituteDeducedTypeTransform> {
4287 QualType Replacement;
4288 bool UseTypeSugar;
4289
4290 public:
4291 SubstituteDeducedTypeTransform(Sema &SemaRef, QualType Replacement,
4292 bool UseTypeSugar = true)
4293 : TreeTransform<SubstituteDeducedTypeTransform>(SemaRef),
4294 Replacement(Replacement), UseTypeSugar(UseTypeSugar) {}
4295
4296 QualType TransformDesugared(TypeLocBuilder &TLB, DeducedTypeLoc TL) {
4297 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-8~svn345461/tools/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 4298, __PRETTY_FUNCTION__))
4298 "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-8~svn345461/tools/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 4298, __PRETTY_FUNCTION__))
;
4299 QualType Result = Replacement;
4300 TemplateTypeParmTypeLoc NewTL = TLB.push<TemplateTypeParmTypeLoc>(Result);
4301 NewTL.setNameLoc(TL.getNameLoc());
4302 return Result;
4303 }
4304
4305 QualType TransformAutoType(TypeLocBuilder &TLB, AutoTypeLoc TL) {
4306 // If we're building the type pattern to deduce against, don't wrap the
4307 // substituted type in an AutoType. Certain template deduction rules
4308 // apply only when a template type parameter appears directly (and not if
4309 // the parameter is found through desugaring). For instance:
4310 // auto &&lref = lvalue;
4311 // must transform into "rvalue reference to T" not "rvalue reference to
4312 // auto type deduced as T" in order for [temp.deduct.call]p3 to apply.
4313 //
4314 // FIXME: Is this still necessary?
4315 if (!UseTypeSugar)
4316 return TransformDesugared(TLB, TL);
4317
4318 QualType Result = SemaRef.Context.getAutoType(
4319 Replacement, TL.getTypePtr()->getKeyword(), Replacement.isNull());
4320 auto NewTL = TLB.push<AutoTypeLoc>(Result);
4321 NewTL.setNameLoc(TL.getNameLoc());
4322 return Result;
4323 }
4324
4325 QualType TransformDeducedTemplateSpecializationType(
4326 TypeLocBuilder &TLB, DeducedTemplateSpecializationTypeLoc TL) {
4327 if (!UseTypeSugar)
4328 return TransformDesugared(TLB, TL);
4329
4330 QualType Result = SemaRef.Context.getDeducedTemplateSpecializationType(
4331 TL.getTypePtr()->getTemplateName(),
4332 Replacement, Replacement.isNull());
4333 auto NewTL = TLB.push<DeducedTemplateSpecializationTypeLoc>(Result);
4334 NewTL.setNameLoc(TL.getNameLoc());
4335 return Result;
4336 }
4337
4338 ExprResult TransformLambdaExpr(LambdaExpr *E) {
4339 // Lambdas never need to be transformed.
4340 return E;
4341 }
4342
4343 QualType Apply(TypeLoc TL) {
4344 // Create some scratch storage for the transformed type locations.
4345 // FIXME: We're just going to throw this information away. Don't build it.
4346 TypeLocBuilder TLB;
4347 TLB.reserve(TL.getFullDataSize());
4348 return TransformType(TLB, TL);
4349 }
4350 };
4351
4352} // namespace
4353
4354Sema::DeduceAutoResult
4355Sema::DeduceAutoType(TypeSourceInfo *Type, Expr *&Init, QualType &Result,
4356 Optional<unsigned> DependentDeductionDepth) {
4357 return DeduceAutoType(Type->getTypeLoc(), Init, Result,
4358 DependentDeductionDepth);
4359}
4360
4361/// Attempt to produce an informative diagostic explaining why auto deduction
4362/// failed.
4363/// \return \c true if diagnosed, \c false if not.
4364static bool diagnoseAutoDeductionFailure(Sema &S,
4365 Sema::TemplateDeductionResult TDK,
4366 TemplateDeductionInfo &Info,
4367 ArrayRef<SourceRange> Ranges) {
4368 switch (TDK) {
4369 case Sema::TDK_Inconsistent: {
4370 // Inconsistent deduction means we were deducing from an initializer list.
4371 auto D = S.Diag(Info.getLocation(), diag::err_auto_inconsistent_deduction);
4372 D << Info.FirstArg << Info.SecondArg;
4373 for (auto R : Ranges)
4374 D << R;
4375 return true;
4376 }
4377
4378 // FIXME: Are there other cases for which a custom diagnostic is more useful
4379 // than the basic "types don't match" diagnostic?
4380
4381 default:
4382 return false;
4383 }
4384}
4385
4386/// Deduce the type for an auto type-specifier (C++11 [dcl.spec.auto]p6)
4387///
4388/// Note that this is done even if the initializer is dependent. (This is
4389/// necessary to support partial ordering of templates using 'auto'.)
4390/// A dependent type will be produced when deducing from a dependent type.
4391///
4392/// \param Type the type pattern using the auto type-specifier.
4393/// \param Init the initializer for the variable whose type is to be deduced.
4394/// \param Result if type deduction was successful, this will be set to the
4395/// deduced type.
4396/// \param DependentDeductionDepth Set if we should permit deduction in
4397/// dependent cases. This is necessary for template partial ordering with
4398/// 'auto' template parameters. The value specified is the template
4399/// parameter depth at which we should perform 'auto' deduction.
4400Sema::DeduceAutoResult
4401Sema::DeduceAutoType(TypeLoc Type, Expr *&Init, QualType &Result,
4402 Optional<unsigned> DependentDeductionDepth) {
4403 if (Init->getType()->isNonOverloadPlaceholderType()) {
4404 ExprResult NonPlaceholder = CheckPlaceholderExpr(Init);
4405 if (NonPlaceholder.isInvalid())
4406 return DAR_FailedAlreadyDiagnosed;
4407 Init = NonPlaceholder.get();
4408 }
4409
4410 if (!DependentDeductionDepth &&
4411 (Type.getType()->isDependentType() || Init->isTypeDependent())) {
4412 Result = SubstituteDeducedTypeTransform(*this, QualType()).Apply(Type);
4413 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-8~svn345461/tools/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 4413, __PRETTY_FUNCTION__))
;
4414 return DAR_Succeeded;
4415 }
4416
4417 // Find the depth of template parameter to synthesize.
4418 unsigned Depth = DependentDeductionDepth.getValueOr(0);
4419
4420 // If this is a 'decltype(auto)' specifier, do the decltype dance.
4421 // Since 'decltype(auto)' can only occur at the top of the type, we
4422 // don't need to go digging for it.
4423 if (const AutoType *AT = Type.getType()->getAs<AutoType>()) {
4424 if (AT->isDecltypeAuto()) {
4425 if (isa<InitListExpr>(Init)) {
4426 Diag(Init->getBeginLoc(), diag::err_decltype_auto_initializer_list);
4427 return DAR_FailedAlreadyDiagnosed;
4428 }
4429
4430 QualType Deduced = BuildDecltypeType(Init, Init->getBeginLoc(), false);
4431 if (Deduced.isNull())
4432 return DAR_FailedAlreadyDiagnosed;
4433 // FIXME: Support a non-canonical deduced type for 'auto'.
4434 Deduced = Context.getCanonicalType(Deduced);
4435 Result = SubstituteDeducedTypeTransform(*this, Deduced).Apply(Type);
4436 if (Result.isNull())
4437 return DAR_FailedAlreadyDiagnosed;
4438 return DAR_Succeeded;
4439 } else if (!getLangOpts().CPlusPlus) {
4440 if (isa<InitListExpr>(Init)) {
4441 Diag(Init->getBeginLoc(), diag::err_auto_init_list_from_c);
4442 return DAR_FailedAlreadyDiagnosed;
4443 }
4444 }
4445 }
4446
4447 SourceLocation Loc = Init->getExprLoc();
4448
4449 LocalInstantiationScope InstScope(*this);
4450
4451 // Build template<class TemplParam> void Func(FuncParam);
4452 TemplateTypeParmDecl *TemplParam = TemplateTypeParmDecl::Create(
4453 Context, nullptr, SourceLocation(), Loc, Depth, 0, nullptr, false, false);
4454 QualType TemplArg = QualType(TemplParam->getTypeForDecl(), 0);
4455 NamedDecl *TemplParamPtr = TemplParam;
4456 FixedSizeTemplateParameterListStorage<1, false> TemplateParamsSt(
4457 Loc, Loc, TemplParamPtr, Loc, nullptr);
4458
4459 QualType FuncParam =
4460 SubstituteDeducedTypeTransform(*this, TemplArg, /*UseTypeSugar*/false)
4461 .Apply(Type);
4462 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-8~svn345461/tools/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 4463, __PRETTY_FUNCTION__))
4463 "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-8~svn345461/tools/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 4463, __PRETTY_FUNCTION__))
;
4464
4465 // Deduce type of TemplParam in Func(Init)
4466 SmallVector<DeducedTemplateArgument, 1> Deduced;
4467 Deduced.resize(1);
4468
4469 TemplateDeductionInfo Info(Loc, Depth);
4470
4471 // If deduction failed, don't diagnose if the initializer is dependent; it
4472 // might acquire a matching type in the instantiation.
4473 auto DeductionFailed = [&](TemplateDeductionResult TDK,
4474 ArrayRef<SourceRange> Ranges) -> DeduceAutoResult {
4475 if (Init->isTypeDependent()) {
4476 Result = SubstituteDeducedTypeTransform(*this, QualType()).Apply(Type);
4477 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-8~svn345461/tools/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 4477, __PRETTY_FUNCTION__))
;
4478 return DAR_Succeeded;
4479 }
4480 if (diagnoseAutoDeductionFailure(*this, TDK, Info, Ranges))
4481 return DAR_FailedAlreadyDiagnosed;
4482 return DAR_Failed;
4483 };
4484
4485 SmallVector<OriginalCallArg, 4> OriginalCallArgs;
4486
4487 InitListExpr *InitList = dyn_cast<InitListExpr>(Init);
4488 if (InitList) {
4489 // Notionally, we substitute std::initializer_list<T> for 'auto' and deduce
4490 // against that. Such deduction only succeeds if removing cv-qualifiers and
4491 // references results in std::initializer_list<T>.
4492 if (!Type.getType().getNonReferenceType()->getAs<AutoType>())
4493 return DAR_Failed;
4494
4495 SourceRange DeducedFromInitRange;
4496 for (unsigned i = 0, e = InitList->getNumInits(); i < e; ++i) {
4497 Expr *Init = InitList->getInit(i);
4498
4499 if (auto TDK = DeduceTemplateArgumentsFromCallArgument(
4500 *this, TemplateParamsSt.get(), 0, TemplArg, Init,
4501 Info, Deduced, OriginalCallArgs, /*Decomposed*/ true,
4502 /*ArgIdx*/ 0, /*TDF*/ 0))
4503 return DeductionFailed(TDK, {DeducedFromInitRange,
4504 Init->getSourceRange()});
4505
4506 if (DeducedFromInitRange.isInvalid() &&
4507 Deduced[0].getKind() != TemplateArgument::Null)
4508 DeducedFromInitRange = Init->getSourceRange();
4509 }
4510 } else {
4511 if (!getLangOpts().CPlusPlus && Init->refersToBitField()) {
4512 Diag(Loc, diag::err_auto_bitfield);
4513 return DAR_FailedAlreadyDiagnosed;
4514 }
4515
4516 if (auto TDK = DeduceTemplateArgumentsFromCallArgument(
4517 *this, TemplateParamsSt.get(), 0, FuncParam, Init, Info, Deduced,
4518 OriginalCallArgs, /*Decomposed*/ false, /*ArgIdx*/ 0, /*TDF*/ 0))
4519 return DeductionFailed(TDK, {});
4520 }
4521
4522 // Could be null if somehow 'auto' appears in a non-deduced context.
4523 if (Deduced[0].getKind() != TemplateArgument::Type)
4524 return DeductionFailed(TDK_Incomplete, {});
4525
4526 QualType DeducedType = Deduced[0].getAsType();
4527
4528 if (InitList) {
4529 DeducedType = BuildStdInitializerList(DeducedType, Loc);
4530 if (DeducedType.isNull())
4531 return DAR_FailedAlreadyDiagnosed;
4532 }
4533
4534 Result = SubstituteDeducedTypeTransform(*this, DeducedType).Apply(Type);
4535 if (Result.isNull())
4536 return DAR_FailedAlreadyDiagnosed;
4537
4538 // Check that the deduced argument type is compatible with the original
4539 // argument type per C++ [temp.deduct.call]p4.
4540 QualType DeducedA = InitList ? Deduced[0].getAsType() : Result;
4541 for (const OriginalCallArg &OriginalArg : OriginalCallArgs) {
4542 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-8~svn345461/tools/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 4543, __PRETTY_FUNCTION__))
4543 "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-8~svn345461/tools/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 4543, __PRETTY_FUNCTION__))
;
4544 if (auto TDK =
4545 CheckOriginalCallArgDeduction(*this, Info, OriginalArg, DeducedA)) {
4546 Result = QualType();
4547 return DeductionFailed(TDK, {});
4548 }
4549 }
4550
4551 return DAR_Succeeded;
4552}
4553
4554QualType Sema::SubstAutoType(QualType TypeWithAuto,
4555 QualType TypeToReplaceAuto) {
4556 if (TypeToReplaceAuto->isDependentType())
4557 TypeToReplaceAuto = QualType();
4558 return SubstituteDeducedTypeTransform(*this, TypeToReplaceAuto)
4559 .TransformType(TypeWithAuto);
4560}
4561
4562TypeSourceInfo *Sema::SubstAutoTypeSourceInfo(TypeSourceInfo *TypeWithAuto,
4563 QualType TypeToReplaceAuto) {
4564 if (TypeToReplaceAuto->isDependentType())
4565 TypeToReplaceAuto = QualType();
4566 return SubstituteDeducedTypeTransform(*this, TypeToReplaceAuto)
4567 .TransformType(TypeWithAuto);
4568}
4569
4570QualType Sema::ReplaceAutoType(QualType TypeWithAuto,
4571 QualType TypeToReplaceAuto) {
4572 return SubstituteDeducedTypeTransform(*this, TypeToReplaceAuto,
4573 /*UseTypeSugar*/ false)
4574 .TransformType(TypeWithAuto);
4575}
4576
4577void Sema::DiagnoseAutoDeductionFailure(VarDecl *VDecl, Expr *Init) {
4578 if (isa<InitListExpr>(Init))
4579 Diag(VDecl->getLocation(),
4580 VDecl->isInitCapture()
4581 ? diag::err_init_capture_deduction_failure_from_init_list
4582 : diag::err_auto_var_deduction_failure_from_init_list)
4583 << VDecl->getDeclName() << VDecl->getType() << Init->getSourceRange();
4584 else
4585 Diag(VDecl->getLocation(),
4586 VDecl->isInitCapture() ? diag::err_init_capture_deduction_failure
4587 : diag::err_auto_var_deduction_failure)
4588 << VDecl->getDeclName() << VDecl->getType() << Init->getType()
4589 << Init->getSourceRange();
4590}
4591
4592bool Sema::DeduceReturnType(FunctionDecl *FD, SourceLocation Loc,
4593 bool Diagnose) {
4594 assert(FD->getReturnType()->isUndeducedType())((FD->getReturnType()->isUndeducedType()) ? static_cast
<void> (0) : __assert_fail ("FD->getReturnType()->isUndeducedType()"
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 4594, __PRETTY_FUNCTION__))
;
4595
4596 // For a lambda's conversion operator, deduce any 'auto' or 'decltype(auto)'
4597 // within the return type from the call operator's type.
4598 if (isLambdaConversionOperator(FD)) {
4599 CXXRecordDecl *Lambda = cast<CXXMethodDecl>(FD)->getParent();
4600 FunctionDecl *CallOp = Lambda->getLambdaCallOperator();
4601
4602 // For a generic lambda, instantiate the call operator if needed.
4603 if (auto *Args = FD->getTemplateSpecializationArgs()) {
4604 CallOp = InstantiateFunctionDeclaration(
4605 CallOp->getDescribedFunctionTemplate(), Args, Loc);
4606 if (!CallOp || CallOp->isInvalidDecl())
4607 return true;
4608
4609 // We might need to deduce the return type by instantiating the definition
4610 // of the operator() function.
4611 if (CallOp->getReturnType()->isUndeducedType())
4612 InstantiateFunctionDefinition(Loc, CallOp);
4613 }
4614
4615 if (CallOp->isInvalidDecl())
4616 return true;
4617 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-8~svn345461/tools/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 4618, __PRETTY_FUNCTION__))
4618 "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-8~svn345461/tools/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 4618, __PRETTY_FUNCTION__))
;
4619
4620 // Build the new return type from scratch.
4621 QualType RetType = getLambdaConversionFunctionResultType(
4622 CallOp->getType()->castAs<FunctionProtoType>());
4623 if (FD->getReturnType()->getAs<PointerType>())
4624 RetType = Context.getPointerType(RetType);
4625 else {
4626 assert(FD->getReturnType()->getAs<BlockPointerType>())((FD->getReturnType()->getAs<BlockPointerType>())
? static_cast<void> (0) : __assert_fail ("FD->getReturnType()->getAs<BlockPointerType>()"
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 4626, __PRETTY_FUNCTION__))
;
4627 RetType = Context.getBlockPointerType(RetType);
4628 }
4629 Context.adjustDeducedFunctionResultType(FD, RetType);
4630 return false;
4631 }
4632
4633 if (FD->getTemplateInstantiationPattern())
4634 InstantiateFunctionDefinition(Loc, FD);
4635
4636 bool StillUndeduced = FD->getReturnType()->isUndeducedType();
4637 if (StillUndeduced && Diagnose && !FD->isInvalidDecl()) {
4638 Diag(Loc, diag::err_auto_fn_used_before_defined) << FD;
4639 Diag(FD->getLocation(), diag::note_callee_decl) << FD;
4640 }
4641
4642 return StillUndeduced;
4643}
4644
4645/// If this is a non-static member function,
4646static void
4647AddImplicitObjectParameterType(ASTContext &Context,
4648 CXXMethodDecl *Method,
4649 SmallVectorImpl<QualType> &ArgTypes) {
4650 // C++11 [temp.func.order]p3:
4651 // [...] The new parameter is of type "reference to cv A," where cv are
4652 // the cv-qualifiers of the function template (if any) and A is
4653 // the class of which the function template is a member.
4654 //
4655 // The standard doesn't say explicitly, but we pick the appropriate kind of
4656 // reference type based on [over.match.funcs]p4.
4657 QualType ArgTy = Context.getTypeDeclType(Method->getParent());
4658 ArgTy = Context.getQualifiedType(ArgTy,
4659 Qualifiers::fromCVRMask(Method->getTypeQualifiers()));
4660 if (Method->getRefQualifier() == RQ_RValue)
4661 ArgTy = Context.getRValueReferenceType(ArgTy);
4662 else
4663 ArgTy = Context.getLValueReferenceType(ArgTy);
4664 ArgTypes.push_back(ArgTy);
4665}
4666
4667/// Determine whether the function template \p FT1 is at least as
4668/// specialized as \p FT2.
4669static bool isAtLeastAsSpecializedAs(Sema &S,
4670 SourceLocation Loc,
4671 FunctionTemplateDecl *FT1,
4672 FunctionTemplateDecl *FT2,
4673 TemplatePartialOrderingContext TPOC,
4674 unsigned NumCallArguments1) {
4675 FunctionDecl *FD1 = FT1->getTemplatedDecl();
4676 FunctionDecl *FD2 = FT2->getTemplatedDecl();
4677 const FunctionProtoType *Proto1 = FD1->getType()->getAs<FunctionProtoType>();
4678 const FunctionProtoType *Proto2 = FD2->getType()->getAs<FunctionProtoType>();
4679
4680 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-8~svn345461/tools/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 4680, __PRETTY_FUNCTION__))
;
4681 TemplateParameterList *TemplateParams = FT2->getTemplateParameters();
4682 SmallVector<DeducedTemplateArgument, 4> Deduced;
4683 Deduced.resize(TemplateParams->size());
4684
4685 // C++0x [temp.deduct.partial]p3:
4686 // The types used to determine the ordering depend on the context in which
4687 // the partial ordering is done:
4688 TemplateDeductionInfo Info(Loc);
4689 SmallVector<QualType, 4> Args2;
4690 switch (TPOC) {
4691 case TPOC_Call: {
4692 // - In the context of a function call, the function parameter types are
4693 // used.
4694 CXXMethodDecl *Method1 = dyn_cast<CXXMethodDecl>(FD1);
4695 CXXMethodDecl *Method2 = dyn_cast<CXXMethodDecl>(FD2);
4696
4697 // C++11 [temp.func.order]p3:
4698 // [...] If only one of the function templates is a non-static
4699 // member, that function template is considered to have a new
4700 // first parameter inserted in its function parameter list. The
4701 // new parameter is of type "reference to cv A," where cv are
4702 // the cv-qualifiers of the function template (if any) and A is
4703 // the class of which the function template is a member.
4704 //
4705 // Note that we interpret this to mean "if one of the function
4706 // templates is a non-static member and the other is a non-member";
4707 // otherwise, the ordering rules for static functions against non-static
4708 // functions don't make any sense.
4709 //
4710 // C++98/03 doesn't have this provision but we've extended DR532 to cover
4711 // it as wording was broken prior to it.
4712 SmallVector<QualType, 4> Args1;
4713
4714 unsigned NumComparedArguments = NumCallArguments1;
4715
4716 if (!Method2 && Method1 && !Method1->isStatic()) {
4717 // Compare 'this' from Method1 against first parameter from Method2.
4718 AddImplicitObjectParameterType(S.Context, Method1, Args1);
4719 ++NumComparedArguments;
4720 } else if (!Method1 && Method2 && !Method2->isStatic()) {
4721 // Compare 'this' from Method2 against first parameter from Method1.
4722 AddImplicitObjectParameterType(S.Context, Method2, Args2);
4723 }
4724
4725 Args1.insert(Args1.end(), Proto1->param_type_begin(),
4726 Proto1->param_type_end());
4727 Args2.insert(Args2.end(), Proto2->param_type_begin(),
4728 Proto2->param_type_end());
4729
4730 // C++ [temp.func.order]p5:
4731 // The presence of unused ellipsis and default arguments has no effect on
4732 // the partial ordering of function templates.
4733 if (Args1.size() > NumComparedArguments)
4734 Args1.resize(NumComparedArguments);
4735 if (Args2.size() > NumComparedArguments)
4736 Args2.resize(NumComparedArguments);
4737 if (DeduceTemplateArguments(S, TemplateParams, Args2.data(), Args2.size(),
4738 Args1.data(), Args1.size(), Info, Deduced,
4739 TDF_None, /*PartialOrdering=*/true))
4740 return false;
4741
4742 break;
4743 }
4744
4745 case TPOC_Conversion:
4746 // - In the context of a call to a conversion operator, the return types
4747 // of the conversion function templates are used.
4748 if (DeduceTemplateArgumentsByTypeMatch(
4749 S, TemplateParams, Proto2->getReturnType(), Proto1->getReturnType(),
4750 Info, Deduced, TDF_None,
4751 /*PartialOrdering=*/true))
4752 return false;
4753 break;
4754
4755 case TPOC_Other:
4756 // - In other contexts (14.6.6.2) the function template's function type
4757 // is used.
4758 if (DeduceTemplateArgumentsByTypeMatch(S, TemplateParams,
4759 FD2->getType(), FD1->getType(),
4760 Info, Deduced, TDF_None,
4761 /*PartialOrdering=*/true))
4762 return false;
4763 break;
4764 }
4765
4766 // C++0x [temp.deduct.partial]p11:
4767 // In most cases, all template parameters must have values in order for
4768 // deduction to succeed, but for partial ordering purposes a template
4769 // parameter may remain without a value provided it is not used in the
4770 // types being used for partial ordering. [ Note: a template parameter used
4771 // in a non-deduced context is considered used. -end note]
4772 unsigned ArgIdx = 0, NumArgs = Deduced.size();
4773 for (; ArgIdx != NumArgs; ++ArgIdx)
4774 if (Deduced[ArgIdx].isNull())
4775 break;
4776
4777 // FIXME: We fail to implement [temp.deduct.type]p1 along this path. We need
4778 // to substitute the deduced arguments back into the template and check that
4779 // we get the right type.
4780
4781 if (ArgIdx == NumArgs) {
4782 // All template arguments were deduced. FT1 is at least as specialized
4783 // as FT2.
4784 return true;
4785 }
4786
4787 // Figure out which template parameters were used.
4788 llvm::SmallBitVector UsedParameters(TemplateParams->size());
4789 switch (TPOC) {
4790 case TPOC_Call:
4791 for (unsigned I = 0, N = Args2.size(); I != N; ++I)
4792 ::MarkUsedTemplateParameters(S.Context, Args2[I], false,
4793 TemplateParams->getDepth(),
4794 UsedParameters);
4795 break;
4796
4797 case TPOC_Conversion:
4798 ::MarkUsedTemplateParameters(S.Context, Proto2->getReturnType(), false,
4799 TemplateParams->getDepth(), UsedParameters);
4800 break;
4801
4802 case TPOC_Other:
4803 ::MarkUsedTemplateParameters(S.Context, FD2->getType(), false,
4804 TemplateParams->getDepth(),
4805 UsedParameters);
4806 break;
4807 }
4808
4809 for (; ArgIdx != NumArgs; ++ArgIdx)
4810 // If this argument had no value deduced but was used in one of the types
4811 // used for partial ordering, then deduction fails.
4812 if (Deduced[ArgIdx].isNull() && UsedParameters[ArgIdx])
4813 return false;
4814
4815 return true;
4816}
4817
4818/// Determine whether this a function template whose parameter-type-list
4819/// ends with a function parameter pack.
4820static bool isVariadicFunctionTemplate(FunctionTemplateDecl *FunTmpl) {
4821 FunctionDecl *Function = FunTmpl->getTemplatedDecl();
4822 unsigned NumParams = Function->getNumParams();
4823 if (NumParams == 0)
4824 return false;
4825
4826 ParmVarDecl *Last = Function->getParamDecl(NumParams - 1);
4827 if (!Last->isParameterPack())
4828 return false;
4829
4830 // Make sure that no previous parameter is a parameter pack.
4831 while (--NumParams > 0) {
4832 if (Function->getParamDecl(NumParams - 1)->isParameterPack())
4833 return false;
4834 }
4835
4836 return true;
4837}
4838
4839/// Returns the more specialized function template according
4840/// to the rules of function template partial ordering (C++ [temp.func.order]).
4841///
4842/// \param FT1 the first function template
4843///
4844/// \param FT2 the second function template
4845///
4846/// \param TPOC the context in which we are performing partial ordering of
4847/// function templates.
4848///
4849/// \param NumCallArguments1 The number of arguments in the call to FT1, used
4850/// only when \c TPOC is \c TPOC_Call.
4851///
4852/// \param NumCallArguments2 The number of arguments in the call to FT2, used
4853/// only when \c TPOC is \c TPOC_Call.
4854///
4855/// \returns the more specialized function template. If neither
4856/// template is more specialized, returns NULL.
4857FunctionTemplateDecl *
4858Sema::getMoreSpecializedTemplate(FunctionTemplateDecl *FT1,
4859 FunctionTemplateDecl *FT2,
4860 SourceLocation Loc,
4861 TemplatePartialOrderingContext TPOC,
4862 unsigned NumCallArguments1,
4863 unsigned NumCallArguments2) {
4864 bool Better1 = isAtLeastAsSpecializedAs(*this, Loc, FT1, FT2, TPOC,
4865 NumCallArguments1);
4866 bool Better2 = isAtLeastAsSpecializedAs(*this, Loc, FT2, FT1, TPOC,
4867 NumCallArguments2);
4868
4869 if (Better1 != Better2) // We have a clear winner
4870 return Better1 ? FT1 : FT2;
4871
4872 if (!Better1 && !Better2) // Neither is better than the other
4873 return nullptr;
4874
4875 // FIXME: This mimics what GCC implements, but doesn't match up with the
4876 // proposed resolution for core issue 692. This area needs to be sorted out,
4877 // but for now we attempt to maintain compatibility.
4878 bool Variadic1 = isVariadicFunctionTemplate(FT1);
4879 bool Variadic2 = isVariadicFunctionTemplate(FT2);
4880 if (Variadic1 != Variadic2)
4881 return Variadic1? FT2 : FT1;
4882
4883 return nullptr;
4884}
4885
4886/// Determine if the two templates are equivalent.
4887static bool isSameTemplate(TemplateDecl *T1, TemplateDecl *T2) {
4888 if (T1 == T2)
4889 return true;
4890
4891 if (!T1 || !T2)
4892 return false;
4893
4894 return T1->getCanonicalDecl() == T2->getCanonicalDecl();
4895}
4896
4897/// Retrieve the most specialized of the given function template
4898/// specializations.
4899///
4900/// \param SpecBegin the start iterator of the function template
4901/// specializations that we will be comparing.
4902///
4903/// \param SpecEnd the end iterator of the function template
4904/// specializations, paired with \p SpecBegin.
4905///
4906/// \param Loc the location where the ambiguity or no-specializations
4907/// diagnostic should occur.
4908///
4909/// \param NoneDiag partial diagnostic used to diagnose cases where there are
4910/// no matching candidates.
4911///
4912/// \param AmbigDiag partial diagnostic used to diagnose an ambiguity, if one
4913/// occurs.
4914///
4915/// \param CandidateDiag partial diagnostic used for each function template
4916/// specialization that is a candidate in the ambiguous ordering. One parameter
4917/// in this diagnostic should be unbound, which will correspond to the string
4918/// describing the template arguments for the function template specialization.
4919///
4920/// \returns the most specialized function template specialization, if
4921/// found. Otherwise, returns SpecEnd.
4922UnresolvedSetIterator Sema::getMostSpecialized(
4923 UnresolvedSetIterator SpecBegin, UnresolvedSetIterator SpecEnd,
4924 TemplateSpecCandidateSet &FailedCandidates,
4925 SourceLocation Loc, const PartialDiagnostic &NoneDiag,
4926 const PartialDiagnostic &AmbigDiag, const PartialDiagnostic &CandidateDiag,
4927 bool Complain, QualType TargetType) {
4928 if (SpecBegin == SpecEnd) {
4929 if (Complain) {
4930 Diag(Loc, NoneDiag);
4931 FailedCandidates.NoteCandidates(*this, Loc);
4932 }
4933 return SpecEnd;
4934 }
4935
4936 if (SpecBegin + 1 == SpecEnd)
4937 return SpecBegin;
4938
4939 // Find the function template that is better than all of the templates it
4940 // has been compared to.
4941 UnresolvedSetIterator Best = SpecBegin;
4942 FunctionTemplateDecl *BestTemplate
4943 = cast<FunctionDecl>(*Best)->getPrimaryTemplate();
4944 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-8~svn345461/tools/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 4944, __PRETTY_FUNCTION__))
;
4945 for (UnresolvedSetIterator I = SpecBegin + 1; I != SpecEnd; ++I) {
4946 FunctionTemplateDecl *Challenger
4947 = cast<FunctionDecl>(*I)->getPrimaryTemplate();
4948 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-8~svn345461/tools/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 4948, __PRETTY_FUNCTION__))
;
4949 if (isSameTemplate(getMoreSpecializedTemplate(BestTemplate, Challenger,
4950 Loc, TPOC_Other, 0, 0),
4951 Challenger)) {
4952 Best = I;
4953 BestTemplate = Challenger;
4954 }
4955 }
4956
4957 // Make sure that the "best" function template is more specialized than all
4958 // of the others.
4959 bool Ambiguous = false;
4960 for (UnresolvedSetIterator I = SpecBegin; I != SpecEnd; ++I) {
4961 FunctionTemplateDecl *Challenger
4962 = cast<FunctionDecl>(*I)->getPrimaryTemplate();
4963 if (I != Best &&
4964 !isSameTemplate(getMoreSpecializedTemplate(BestTemplate, Challenger,
4965 Loc, TPOC_Other, 0, 0),
4966 BestTemplate)) {
4967 Ambiguous = true;
4968 break;
4969 }
4970 }
4971
4972 if (!Ambiguous) {
4973 // We found an answer. Return it.
4974 return Best;
4975 }
4976
4977 // Diagnose the ambiguity.
4978 if (Complain) {
4979 Diag(Loc, AmbigDiag);
4980
4981 // FIXME: Can we order the candidates in some sane way?
4982 for (UnresolvedSetIterator I = SpecBegin; I != SpecEnd; ++I) {
4983 PartialDiagnostic PD = CandidateDiag;
4984 const auto *FD = cast<FunctionDecl>(*I);
4985 PD << FD << getTemplateArgumentBindingsText(
4986 FD->getPrimaryTemplate()->getTemplateParameters(),
4987 *FD->getTemplateSpecializationArgs());
4988 if (!TargetType.isNull())
4989 HandleFunctionTypeMismatch(PD, FD->getType(), TargetType);
4990 Diag((*I)->getLocation(), PD);
4991 }
4992 }
4993
4994 return SpecEnd;
4995}
4996
4997/// Determine whether one partial specialization, P1, is at least as
4998/// specialized than another, P2.
4999///
5000/// \tparam TemplateLikeDecl The kind of P2, which must be a
5001/// TemplateDecl or {Class,Var}TemplatePartialSpecializationDecl.
5002/// \param T1 The injected-class-name of P1 (faked for a variable template).
5003/// \param T2 The injected-class-name of P2 (faked for a variable template).
5004template<typename TemplateLikeDecl>
5005static bool isAtLeastAsSpecializedAs(Sema &S, QualType T1, QualType T2,
5006 TemplateLikeDecl *P2,
5007 TemplateDeductionInfo &Info) {
5008 // C++ [temp.class.order]p1:
5009 // For two class template partial specializations, the first is at least as
5010 // specialized as the second if, given the following rewrite to two
5011 // function templates, the first function template is at least as
5012 // specialized as the second according to the ordering rules for function
5013 // templates (14.6.6.2):
5014 // - the first function template has the same template parameters as the
5015 // first partial specialization and has a single function parameter
5016 // whose type is a class template specialization with the template
5017 // arguments of the first partial specialization, and
5018 // - the second function template has the same template parameters as the
5019 // second partial specialization and has a single function parameter
5020 // whose type is a class template specialization with the template
5021 // arguments of the second partial specialization.
5022 //
5023 // Rather than synthesize function templates, we merely perform the
5024 // equivalent partial ordering by performing deduction directly on
5025 // the template arguments of the class template partial
5026 // specializations. This computation is slightly simpler than the
5027 // general problem of function template partial ordering, because
5028 // class template partial specializations are more constrained. We
5029 // know that every template parameter is deducible from the class
5030 // template partial specialization's template arguments, for
5031 // example.
5032 SmallVector<DeducedTemplateArgument, 4> Deduced;
5033
5034 // Determine whether P1 is at least as specialized as P2.
5035 Deduced.resize(P2->getTemplateParameters()->size());
5036 if (DeduceTemplateArgumentsByTypeMatch(S, P2->getTemplateParameters(),
5037 T2, T1, Info, Deduced, TDF_None,
5038 /*PartialOrdering=*/true))
5039 return false;
5040
5041 SmallVector<TemplateArgument, 4> DeducedArgs(Deduced.begin(),
5042 Deduced.end());
5043 Sema::InstantiatingTemplate Inst(S, Info.getLocation(), P2, DeducedArgs,
5044 Info);
5045 auto *TST1 = T1->castAs<TemplateSpecializationType>();
5046 if (FinishTemplateArgumentDeduction(
5047 S, P2, /*PartialOrdering=*/true,
5048 TemplateArgumentList(TemplateArgumentList::OnStack,
5049 TST1->template_arguments()),
5050 Deduced, Info))
5051 return false;
5052
5053 return true;
5054}
5055
5056/// Returns the more specialized class template partial specialization
5057/// according to the rules of partial ordering of class template partial
5058/// specializations (C++ [temp.class.order]).
5059///
5060/// \param PS1 the first class template partial specialization
5061///
5062/// \param PS2 the second class template partial specialization
5063///
5064/// \returns the more specialized class template partial specialization. If
5065/// neither partial specialization is more specialized, returns NULL.
5066ClassTemplatePartialSpecializationDecl *
5067Sema::getMoreSpecializedPartialSpecialization(
5068 ClassTemplatePartialSpecializationDecl *PS1,
5069 ClassTemplatePartialSpecializationDecl *PS2,
5070 SourceLocation Loc) {
5071 QualType PT1 = PS1->getInjectedSpecializationType();
5072 QualType PT2 = PS2->getInjectedSpecializationType();
5073
5074 TemplateDeductionInfo Info(Loc);
5075 bool Better1 = isAtLeastAsSpecializedAs(*this, PT1, PT2, PS2, Info);
5076 bool Better2 = isAtLeastAsSpecializedAs(*this, PT2, PT1, PS1, Info);
5077
5078 if (Better1 == Better2)
5079 return nullptr;
5080
5081 return Better1 ? PS1 : PS2;
5082}
5083
5084bool Sema::isMoreSpecializedThanPrimary(
5085 ClassTemplatePartialSpecializationDecl *Spec, TemplateDeductionInfo &Info) {
5086 ClassTemplateDecl *Primary = Spec->getSpecializedTemplate();
5087 QualType PrimaryT = Primary->getInjectedClassNameSpecialization();
5088 QualType PartialT = Spec->getInjectedSpecializationType();
5089 if (!isAtLeastAsSpecializedAs(*this, PartialT, PrimaryT, Primary, Info))
5090 return false;
5091 if (isAtLeastAsSpecializedAs(*this, PrimaryT, PartialT, Spec, Info)) {
5092 Info.clearSFINAEDiagnostic();
5093 return false;
5094 }
5095 return true;
5096}
5097
5098VarTemplatePartialSpecializationDecl *
5099Sema::getMoreSpecializedPartialSpecialization(
5100 VarTemplatePartialSpecializationDecl *PS1,
5101 VarTemplatePartialSpecializationDecl *PS2, SourceLocation Loc) {
5102 // Pretend the variable template specializations are class template
5103 // specializations and form a fake injected class name type for comparison.
5104 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-8~svn345461/tools/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 5106, __PRETTY_FUNCTION__))
5105 "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-8~svn345461/tools/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 5106, __PRETTY_FUNCTION__))
5106 " 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-8~svn345461/tools/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 5106, __PRETTY_FUNCTION__))
;
5107 TemplateName Name(PS1->getSpecializedTemplate());
5108 TemplateName CanonTemplate = Context.getCanonicalTemplateName(Name);
5109 QualType PT1 = Context.getTemplateSpecializationType(
5110 CanonTemplate, PS1->getTemplateArgs().asArray());
5111 QualType PT2 = Context.getTemplateSpecializationType(
5112 CanonTemplate, PS2->getTemplateArgs().asArray());
5113
5114 TemplateDeductionInfo Info(Loc);
5115 bool Better1 = isAtLeastAsSpecializedAs(*this, PT1, PT2, PS2, Info);
5116 bool Better2 = isAtLeastAsSpecializedAs(*this, PT2, PT1, PS1, Info);
5117
5118 if (Better1 == Better2)
5119 return nullptr;
5120
5121 return Better1 ? PS1 : PS2;
5122}
5123
5124bool Sema::isMoreSpecializedThanPrimary(
5125 VarTemplatePartialSpecializationDecl *Spec, TemplateDeductionInfo &Info) {
5126 TemplateDecl *Primary = Spec->getSpecializedTemplate();
5127 // FIXME: Cache the injected template arguments rather than recomputing
5128 // them for each partial specialization.
5129 SmallVector<TemplateArgument, 8> PrimaryArgs;
5130 Context.getInjectedTemplateArgs(Primary->getTemplateParameters(),
5131 PrimaryArgs);
5132
5133 TemplateName CanonTemplate =
5134 Context.getCanonicalTemplateName(TemplateName(Primary));
5135 QualType PrimaryT = Context.getTemplateSpecializationType(
5136 CanonTemplate, PrimaryArgs);
5137 QualType PartialT = Context.getTemplateSpecializationType(
5138 CanonTemplate, Spec->getTemplateArgs().asArray());
5139 if (!isAtLeastAsSpecializedAs(*this, PartialT, PrimaryT, Primary, Info))
5140 return false;
5141 if (isAtLeastAsSpecializedAs(*this, PrimaryT, PartialT, Spec, Info)) {
5142 Info.clearSFINAEDiagnostic();
5143 return false;
5144 }
5145 return true;
5146}
5147
5148bool Sema::isTemplateTemplateParameterAtLeastAsSpecializedAs(
5149 TemplateParameterList *P, TemplateDecl *AArg, SourceLocation Loc) {
5150 // C++1z [temp.arg.template]p4: (DR 150)
5151 // A template template-parameter P is at least as specialized as a
5152 // template template-argument A if, given the following rewrite to two
5153 // function templates...
5154
5155 // Rather than synthesize function templates, we merely perform the
5156 // equivalent partial ordering by performing deduction directly on
5157 // the template parameter lists of the template template parameters.
5158 //
5159 // Given an invented class template X with the template parameter list of
5160 // A (including default arguments):
5161 TemplateName X = Context.getCanonicalTemplateName(TemplateName(AArg));
5162 TemplateParameterList *A = AArg->getTemplateParameters();
5163
5164 // - Each function template has a single function parameter whose type is
5165 // a specialization of X with template arguments corresponding to the
5166 // template parameters from the respective function template
5167 SmallVector<TemplateArgument, 8> AArgs;
5168 Context.getInjectedTemplateArgs(A, AArgs);
5169
5170 // Check P's arguments against A's parameter list. This will fill in default
5171 // template arguments as needed. AArgs are already correct by construction.
5172 // We can't just use CheckTemplateIdType because that will expand alias
5173 // templates.
5174 SmallVector<TemplateArgument, 4> PArgs;
5175 {
5176 SFINAETrap Trap(*this);
5177
5178 Context.getInjectedTemplateArgs(P, PArgs);
5179 TemplateArgumentListInfo PArgList(P->getLAngleLoc(), P->getRAngleLoc());
5180 for (unsigned I = 0, N = P->size(); I != N; ++I) {
5181 // Unwrap packs that getInjectedTemplateArgs wrapped around pack
5182 // expansions, to form an "as written" argument list.
5183 TemplateArgument Arg = PArgs[I];
5184 if (Arg.getKind() == TemplateArgument::Pack) {
5185 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-8~svn345461/tools/clang/lib/Sema/SemaTemplateDeduction.cpp"
, 5185, __PRETTY_FUNCTION__))
;
5186 Arg = *Arg.pack_begin();
5187 }
5188 PArgList.addArgument(getTrivialTemplateArgumentLoc(
5189 Arg, QualType(), P->getParam(I)->getLocation()));
5190 }
5191 PArgs.clear();
5192
5193 // C++1z [temp.arg.template]p3:
5194 // If the rewrite produces an invalid type, then P is not at least as
5195 // specialized as A.
5196 if (CheckTemplateArgumentList(AArg, Loc, PArgList, false, PArgs) ||
5197 Trap.hasErrorOccurred())
5198 return false;
5199 }
5200
5201 QualType AType = Context.getTemplateSpecializationType(X, AArgs);
5202 QualType PType = Context.getTemplateSpecializationType(X, PArgs);
5203
5204 // ... the function template corresponding to P is at least as specialized
5205 // as the function template corresponding to A according to the partial
5206 // ordering rules for function templates.
5207 TemplateDeductionInfo Info(Loc, A->getDepth());
5208 return isAtLeastAsSpecializedAs(*this, PType, AType, AArg, Info);
5209}
5210
5211/// Mark the template parameters that are used by the given
5212/// expression.
5213static void
5214MarkUsedTemplateParameters(ASTContext &Ctx,
5215 const Expr *E,
5216 bool OnlyDeduced,
5217 unsigned Depth,
5218 llvm::SmallBitVector &Used) {
5219 // We can deduce from a pack expansion.
5220 if (const PackExpansionExpr *Expansion = dyn_cast<PackExpansionExpr>(E))
5221 E = Expansion->getPattern();
5222
5223 // Skip through any implicit casts we added while type-checking, and any
5224 // substitutions performed by template alias expansion.
5225 while (true) {
5226 if (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E))
5227 E = ICE->getSubExpr();
5228 else if (const SubstNonTypeTemplateParmExpr *Subst =
5229 dyn_cast<SubstNonTypeTemplateParmExpr>(E))
5230 E = Subst->getReplacement();
5231 else
5232 break;
5233 }
5234
5235 // FIXME: if !OnlyDeduced, we have to walk the whole subexpression to
5236 // find other occurrences of template parameters.
5237 const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E);
5238 if (!DRE)
5239 return;
5240
5241 const NonTypeTemplateParmDecl *NTTP
5242 = dyn_cast<NonTypeTemplateParmDecl>(DRE->getDecl());
5243 if (!NTTP)
5244 return;
5245
5246 if (NTTP->getDepth() == Depth)
5247 Used[NTTP->getIndex()] = true;
5248
5249 // In C++17 mode, additional arguments may be deduced from the type of a
5250 // non-type argument.
5251 if (Ctx.getLangOpts().CPlusPlus17)
5252 MarkUsedTemplateParameters(Ctx, NTTP->getType(), OnlyDeduced, Depth, Used);
5253}
5254
5255/// Mark the template parameters that are used by the given
5256/// nested name specifier.
5257static void
5258MarkUsedTemplateParameters(ASTContext &Ctx,
5259 NestedNameSpecifier *NNS,
5260 bool OnlyDeduced,
5261 unsigned Depth,
5262 llvm::SmallBitVector &Used) {
5263 if (!NNS)
5264 return;
5265
5266 MarkUsedTemplateParameters(Ctx, NNS->getPrefix(), OnlyDeduced, Depth,
5267 Used);
5268 MarkUsedTemplateParameters(Ctx, QualType(NNS->getAsType(), 0),
5269 OnlyDeduced, Depth, Used);
5270}
5271
5272/// Mark the template parameters that are used by the given
5273/// template name.
5274static void
5275MarkUsedTemplateParameters(ASTContext &Ctx,
5276 TemplateName Name,
5277 bool OnlyDeduced,
5278 unsigned Depth,
5279 llvm::SmallBitVector &Used) {
5280 if (TemplateDecl *Template = Name.getAsTemplateDecl()) {
5281 if (TemplateTemplateParmDecl *TTP
5282 = dyn_cast<TemplateTemplateParmDecl>(Template)) {
5283 if (TTP->getDepth() == Depth)
5284 Used[TTP->getIndex()] = true;
5285 }
5286 return;
5287 }
5288
5289 if (QualifiedTemplateName *QTN = Name.getAsQualifiedTemplateName())
5290 MarkUsedTemplateParameters(Ctx, QTN->getQualifier(), OnlyDeduced,
5291 Depth, Used);
5292 if (DependentTemplateName *DTN = Name.getAsDependentTemplateName())
5293 MarkUsedTemplateParameters(Ctx, DTN->getQualifier(), OnlyDeduced,
5294 Depth, Used);
5295}
5296
5297/// Mark the template parameters that are used by the given
5298/// type.
5299static void
5300MarkUsedTemplateParameters(ASTContext &Ctx, QualType T,
5301 bool OnlyDeduced,
5302 unsigned Depth,
5303 llvm::SmallBitVector &Used) {
5304 if (T.isNull())
5305 return;
5306
5307 // Non-dependent types have nothing deducible
5308 if (!T->isDependentType())
5309 return;
5310
5311 T = Ctx.getCanonicalType(T);
5312 switch (T->getTypeClass()) {
5313 case Type::Pointer:
5314 MarkUsedTemplateParameters(Ctx,
5315 cast<PointerType>(T)->getPointeeType(),
5316 OnlyDeduced,
5317 Depth,
5318 Used);
5319 break;
5320
5321 case Type::BlockPointer:
5322 MarkUsedTemplateParameters(Ctx,
5323 cast<BlockPointerType>(T)->getPointeeType(),
5324 OnlyDeduced,
5325 Depth,
5326 Used);
5327 break;
5328
5329 case Type::LValueReference:
5330 case Type::RValueReference:
5331 MarkUsedTemplateParameters(Ctx,
5332 cast<ReferenceType>(T)->getPointeeType(),
5333 OnlyDeduced,
5334 Depth,
5335 Used);
5336 break;
5337
5338 case Type::MemberPointer: {
5339 const MemberPointerType *MemPtr = cast<MemberPointerType>(T.getTypePtr());
5340 MarkUsedTemplateParameters(Ctx, MemPtr->getPointeeType(), OnlyDeduced,
5341 Depth, Used);
5342 MarkUsedTemplateParameters(Ctx, QualType(MemPtr->getClass(), 0),
5343 OnlyDeduced, Depth, Used);
5344 break;
5345 }
5346
5347 case Type::DependentSizedArray:
5348 MarkUsedTemplateParameters(Ctx,
5349 cast<DependentSizedArrayType>(T)->getSizeExpr(),
5350 OnlyDeduced, Depth, Used);
5351 // Fall through to check the element type
5352 LLVM_FALLTHROUGH[[clang::fallthrough]];
5353
5354 case Type::ConstantArray:
5355 case Type::IncompleteArray:
5356 MarkUsedTemplateParameters(Ctx,
5357 cast<ArrayType>(T)->getElementType(),
5358 OnlyDeduced, Depth, Used);
5359 break;
5360
5361 case Type::Vector:
5362 case Type::ExtVector:
5363 MarkUsedTemplateParameters(Ctx,
5364 cast<VectorType>(T)->getElementType(),
5365 OnlyDeduced, Depth, Used);
5366 break;
5367
5368 case Type::DependentVector: {
5369 const auto *VecType = cast<DependentVectorType>(T);
5370 MarkUsedTemplateParameters(Ctx, VecType->getElementType(), OnlyDeduced,
5371 Depth, Used);
5372 MarkUsedTemplateParameters(Ctx, VecType->getSizeExpr(), OnlyDeduced, Depth,
5373 Used);
5374 break;
5375 }
5376 case Type::DependentSizedExtVector: {
5377 const DependentSizedExtVectorType *VecType
5378 = cast<DependentSizedExtVectorType>(T);
5379 MarkUsedTemplateParameters(Ctx, VecType->getElementType(), OnlyDeduced,
5380 Depth, Used);
5381 MarkUsedTemplateParameters(Ctx, VecType->getSizeExpr(), OnlyDeduced,
5382 Depth, Used);
5383 break;
5384 }
5385
5386 case Type::DependentAddressSpace: {
5387 const DependentAddressSpaceType *DependentASType =
5388 cast<DependentAddressSpaceType>(T);
5389 MarkUsedTemplateParameters(Ctx, DependentASType->getPointeeType(),
5390 OnlyDeduced, Depth, Used);
5391 MarkUsedTemplateParameters(Ctx,
5392 DependentASType->getAddrSpaceExpr(),
5393 OnlyDeduced, Depth, Used);
5394 break;
5395 }
5396
5397 case Type::FunctionProto: {
5398 const FunctionProtoType *Proto = cast<FunctionProtoType>(T);
5399 MarkUsedTemplateParameters(Ctx, Proto->getReturnType(), OnlyDeduced, Depth,
5400 Used);
5401 for (unsigned I = 0, N = Proto->getNumParams(); I != N; ++I) {
5402 // C++17 [temp.deduct.type]p5:
5403 // The non-deduced contexts are: [...]
5404 // -- A function parameter pack that does not occur at the end of the
5405 // parameter-declaration-list.
5406 if (!OnlyDeduced || I + 1 == N ||
5407 !Proto->getParamType(I)->getAs<PackExpansionType>()) {
5408 MarkUsedTemplateParameters(Ctx, Proto->getParamType(I), OnlyDeduced,
5409 Depth, Used);
5410 } else {
5411 // FIXME: C++17 [temp.deduct.call]p1:
5412 // When a function parameter pack appears in a non-deduced context,
5413 // the type of that pack is never deduced.
5414 //
5415 // We should also track a set of "never deduced" parameters, and
5416 // subtract that from the list of deduced parameters after marking.
5417 }
5418 }
5419 if (auto *E = Proto->getNoexceptExpr())
5420 MarkUsedTemplateParameters(Ctx, E, OnlyDeduced, Depth, Used);
5421 break;
5422 }
5423
5424 case Type::TemplateTypeParm: {
5425 const TemplateTypeParmType *TTP = cast<TemplateTypeParmType>(T);
5426 if (TTP->getDepth() == Depth)
5427 Used[TTP->getIndex()] = true;
5428 break;
5429 }
5430
5431 case Type::SubstTemplateTypeParmPack: {
5432 const SubstTemplateTypeParmPackType *Subst
5433 = cast<SubstTemplateTypeParmPackType>(T);
5434 MarkUsedTemplateParameters(Ctx,
5435 QualType(Subst->getReplacedParameter(), 0),
5436 OnlyDeduced, Depth, Used);
5437 MarkUsedTemplateParameters(Ctx, Subst->getArgumentPack(),
5438 OnlyDeduced, Depth, Used);
5439 break;
5440 }
5441
5442 case Type::InjectedClassName:
5443 T = cast<InjectedClassNameType>(T)->getInjectedSpecializationType();
5444 LLVM_FALLTHROUGH[[clang::fallthrough]];
5445
5446 case Type::TemplateSpecialization: {
5447 const TemplateSpecializationType *Spec
5448 = cast<TemplateSpecializationType>(T);
5449 MarkUsedTemplateParameters(Ctx, Spec->getTemplateName(), OnlyDeduced,
5450 Depth, Used);
5451
5452 // C++0x [temp.deduct.type]p9:
5453 // If the template argument list of P contains a pack expansion that is
5454 // not the last template argument, the entire template argument list is a
5455 // non-deduced context.
5456 if (OnlyDeduced &&
5457 hasPackExpansionBeforeEnd(Spec->template_arguments()))
5458 break;
5459
5460 for (unsigned I = 0, N = Spec->getNumArgs(); I != N; ++I)
5461 MarkUsedTemplateParameters(Ctx, Spec->getArg(I), OnlyDeduced, Depth,
5462 Used);
5463 break;
5464 }
5465
5466 case Type::Complex:
5467 if (!OnlyDeduced)
5468 MarkUsedTemplateParameters(Ctx,
5469 cast<ComplexType>(T)->getElementType(),
5470 OnlyDeduced, Depth, Used);
5471 break;
5472
5473 case Type::Atomic:
5474 if (!OnlyDeduced)
5475 MarkUsedTemplateParameters(Ctx,
5476 cast<AtomicType>(T)->getValueType(),
5477 OnlyDeduced, Depth, Used);
5478 break;
5479
5480 case Type::DependentName:
5481 if (!OnlyDeduced)
5482 MarkUsedTemplateParameters(Ctx,
5483 cast<DependentNameType>(T)->getQualifier(),
5484 OnlyDeduced, Depth, Used);
5485 break;
5486
5487 case Type::DependentTemplateSpecialization: {
5488 // C++14 [temp.deduct.type]p5:
5489 // The non-deduced contexts are:
5490 // -- The nested-name-specifier of a type that was specified using a
5491 // qualified-id
5492 //
5493 // C++14 [temp.deduct.type]p6:
5494 // When a type name is specified in a way that includes a non-deduced
5495 // context, all of the types that comprise that type name are also
5496 // non-deduced.
5497 if (OnlyDeduced)
5498 break;
5499
5500 const DependentTemplateSpecializationType *Spec
5501 = cast<DependentTemplateSpecializationType>(T);
5502
5503 MarkUsedTemplateParameters(Ctx, Spec->getQualifier(),
5504 OnlyDeduced, Depth, Used);
5505
5506 for (unsigned I = 0, N = Spec->getNumArgs(); I != N; ++I)
5507 MarkUsedTemplateParameters(Ctx, Spec->getArg(I), OnlyDeduced, Depth,
5508 Used);
5509 break;
5510 }
5511
5512 case Type::TypeOf:
5513 if (!OnlyDeduced)
5514 MarkUsedTemplateParameters(Ctx,
5515 cast<TypeOfType>(T)->getUnderlyingType(),
5516 OnlyDeduced, Depth, Used);
5517 break;
5518
5519 case Type::TypeOfExpr:
5520 if (!OnlyDeduced)
5521 MarkUsedTemplateParameters(Ctx,
5522 cast<TypeOfExprType>(T)->getUnderlyingExpr(),
5523 OnlyDeduced, Depth, Used);
5524 break;
5525
5526 case Type::Decltype:
5527 if (!OnlyDeduced)
5528 MarkUsedTemplateParameters(Ctx,
5529 cast<DecltypeType>(T)->getUnderlyingExpr(),
5530 OnlyDeduced, Depth, Used);
5531 break;
5532
5533 case Type::UnaryTransform:
5534 if (!OnlyDeduced)
5535 MarkUsedTemplateParameters(Ctx,
5536 cast<UnaryTransformType>(T)->getUnderlyingType(),
5537 OnlyDeduced, Depth, Used);
5538 break;
5539
5540 case Type::PackExpansion:
5541 MarkUsedTemplateParameters(Ctx,
5542 cast<PackExpansionType>(T)->getPattern(),
5543 OnlyDeduced, Depth, Used);
5544 break;
5545
5546 case Type::Auto:
5547 case Type::DeducedTemplateSpecialization:
5548 MarkUsedTemplateParameters(Ctx,
5549 cast<DeducedType>(T)->getDeducedType(),
5550 OnlyDeduced, Depth, Used);
5551 break;
5552
5553 // None of these types have any template parameters in them.
5554 case Type::Builtin:
5555 case Type::VariableArray:
5556 case Type::FunctionNoProto:
5557 case Type::Record:
5558 case Type::Enum:
5559 case Type::ObjCInterface:
5560 case Type::ObjCObject:
5561 case Type::ObjCObjectPointer:
5562 case Type::UnresolvedUsing:
5563 case Type::Pipe:
5564#define TYPE(Class, Base)
5565#define ABSTRACT_TYPE(Class, Base)
5566#define DEPENDENT_TYPE(Class, Base)
5567#define NON_CANONICAL_TYPE(Class, Base) case Type::Class:
5568#include "clang/AST/TypeNodes.def"
5569 break;
5570 }
5571}
5572
5573/// Mark the template parameters that are used by this
5574/// template argument.
5575static void
5576MarkUsedTemplateParameters(ASTContext &Ctx,
5577 const TemplateArgument &TemplateArg,
5578 bool OnlyDeduced,
5579 unsigned Depth,
5580 llvm::SmallBitVector &Used) {
5581 switch (TemplateArg.getKind()) {
5582 case TemplateArgument::Null:
5583 case TemplateArgument::Integral:
5584 case TemplateArgument::Declaration:
5585 break;
5586
5587 case TemplateArgument::NullPtr:
5588 MarkUsedTemplateParameters(Ctx, TemplateArg.getNullPtrType(), OnlyDeduced,
5589 Depth, Used);
5590 break;
5591
5592 case TemplateArgument::Type:
5593 MarkUsedTemplateParameters(Ctx, TemplateArg.getAsType(), OnlyDeduced,
5594 Depth, Used);
5595 break;
5596
5597 case TemplateArgument::Template:
5598 case TemplateArgument::TemplateExpansion:
5599 MarkUsedTemplateParameters(Ctx,
5600 TemplateArg.getAsTemplateOrTemplatePattern(),
5601 OnlyDeduced, Depth, Used);
5602 break;
5603
5604 case TemplateArgument::Expression:
5605 MarkUsedTemplateParameters(Ctx, TemplateArg.getAsExpr(), OnlyDeduced,
5606 Depth, Used);
5607 break;
5608
5609 case TemplateArgument::Pack:
5610 for (const auto &P : TemplateArg.pack_elements())
5611 MarkUsedTemplateParameters(Ctx, P, OnlyDeduced, Depth, Used);
5612 break;
5613 }
5614}
5615
5616/// Mark which template parameters can be deduced from a given
5617/// template argument list.
5618///
5619/// \param TemplateArgs the template argument list from which template
5620/// parameters will be deduced.
5621///
5622/// \param Used a bit vector whose elements will be set to \c true
5623/// to indicate when the corresponding template parameter will be
5624/// deduced.
5625void
5626Sema::MarkUsedTemplateParameters(const TemplateArgumentList &TemplateArgs,
5627 bool OnlyDeduced, unsigned Depth,
5628 llvm::SmallBitVector &Used) {
5629 // C++0x [temp.deduct.type]p9:
5630 // If the template argument list of P contains a pack expansion that is not
5631 // the last template argument, the entire template argument list is a
5632 // non-deduced context.
5633 if (OnlyDeduced &&
5634 hasPackExpansionBeforeEnd(TemplateArgs.asArray()))
5635 return;
5636
5637 for (unsigned I = 0, N = TemplateArgs.size(); I != N; ++I)
5638 ::MarkUsedTemplateParameters(Context, TemplateArgs[I], OnlyDeduced,
5639 Depth, Used);
5640}
5641
5642/// Marks all of the template parameters that will be deduced by a
5643/// call to the given function template.
5644void Sema::MarkDeducedTemplateParameters(
5645 ASTContext &Ctx, const FunctionTemplateDecl *FunctionTemplate,
5646 llvm::SmallBitVector &Deduced) {
5647 TemplateParameterList *TemplateParams
5648 = FunctionTemplate->getTemplateParameters();
5649 Deduced.clear();
5650 Deduced.resize(TemplateParams->size());
5651
5652 FunctionDecl *Function = FunctionTemplate->getTemplatedDecl();
5653 for (unsigned I = 0, N = Function->getNumParams(); I != N; ++I)
5654 ::MarkUsedTemplateParameters(Ctx, Function->getParamDecl(I)->getType(),
5655 true, TemplateParams->getDepth(), Deduced);
5656}
5657
5658bool hasDeducibleTemplateParameters(Sema &S,
5659 FunctionTemplateDecl *FunctionTemplate,
5660 QualType T) {
5661 if (!T->isDependentType())
5662 return false;
5663
5664 TemplateParameterList *TemplateParams
5665 = FunctionTemplate->getTemplateParameters();
5666 llvm::SmallBitVector Deduced(TemplateParams->size());
5667 ::MarkUsedTemplateParameters(S.Context, T, true, TemplateParams->getDepth(),
5668 Deduced);
5669
5670 return Deduced.any();
5671}

/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/ADT/SmallBitVector.h

</
1//===- llvm/ADT/SmallBitVector.h - 'Normally small' bit vectors -*- C++ -*-===//
2//
3// The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This file implements the SmallBitVector class.
11//
12//===----------------------------------------------------------------------===//
13
14#ifndef LLVM_ADT_SMALLBITVECTOR_H
15#define LLVM_ADT_SMALLBITVECTOR_H
16
17#include "llvm/ADT/BitVector.h"
18#include "llvm/ADT/iterator_range.h"
19#include "llvm/Support/MathExtras.h"
20#include <algorithm>
21#include <cassert>
22#include <climits>
23#include <cstddef>
24#include <cstdint>
25#include <limits>
26#include <utility>
27
28namespace llvm {
29
30/// This is a 'bitvector' (really, a variable-sized bit array), optimized for
31/// the case when the array is small. It contains one pointer-sized field, which
32/// is directly used as a plain collection of bits when possible, or as a
33/// pointer to a larger heap-allocated array when necessary. This allows normal
34/// "small" cases to be fast without losing generality for large inputs.
35class SmallBitVector {
36 // TODO: In "large" mode, a pointer to a BitVector is used, leading to an
37 // unnecessary level of indirection. It would be more efficient to use a
38 // pointer to memory containing size, allocation size, and the array of bits.
39 uintptr_t X = 1;
40
41 enum {
42 // The number of bits in this class.
43 NumBaseBits = sizeof(uintptr_t) * CHAR_BIT8,
44
45 // One bit is used to discriminate between small and large mode. The
46 // remaining bits are used for the small-mode representation.
47 SmallNumRawBits = NumBaseBits - 1,
48
49 // A few more bits are used to store the size of the bit set in small mode.
50 // Theoretically this is a ceil-log2. These bits are encoded in the most
51 // significant bits of the raw bits.
52 SmallNumSizeBits = (NumBaseBits == 32 ? 5 :
53 NumBaseBits == 64 ? 6 :
54 SmallNumRawBits),
55
56 // The remaining bits are used to store the actual set in small mode.
57 SmallNumDataBits = SmallNumRawBits - SmallNumSizeBits
58 };
59
60 static_assert(NumBaseBits == 64 || NumBaseBits == 32,
61 "Unsupported word size");
62
63public:
64 using size_type = unsigned;
65
66 // Encapsulation of a single bit.
67 class reference {
68 SmallBitVector &TheVector;
69 unsigned BitPos;
70
71 public:
72 reference(SmallBitVector &b, unsigned Idx) : TheVector(b), BitPos(Idx) {}
73
74 reference(const reference&) = default;
75
76 reference& operator=(reference t) {
77 *this = bool(t);
78 return *this;
79 }
80
81 reference& operator=(bool t) {
82 if (t)
83 TheVector.set(BitPos);
84 else
85 TheVector.reset(BitPos);
86 return *this;
87 }
88
89 operator bool() const {
90 return const_cast<const SmallBitVector &>(TheVector).operator[](BitPos);
91 }
92 };
93
94private:
95 bool isSmall() const {
96 return X & uintptr_t(1);
97 }
98
99 BitVector *getPointer() const {
100 assert(!isSmall())((!isSmall()) ? static_cast<void> (0) : __assert_fail (
"!isSmall()", "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/ADT/SmallBitVector.h"
, 100, __PRETTY_FUNCTION__))
;
101 return reinterpret_cast<BitVector *>(X);
102 }
103
104 void switchToSmall(uintptr_t NewSmallBits, size_t NewSize) {
105 X = 1;
106 setSmallSize(NewSize);
107 setSmallBits(NewSmallBits);
108 }
109
110 void switchToLarge(BitVector *BV) {
111 X = reinterpret_cast<uintptr_t>(BV);
112 assert(!isSmall() && "Tried to use an unaligned pointer")((!isSmall() && "Tried to use an unaligned pointer") ?
static_cast<void> (0) : __assert_fail ("!isSmall() && \"Tried to use an unaligned pointer\""
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/ADT/SmallBitVector.h"
, 112, __PRETTY_FUNCTION__))
;
113 }
114
115 // Return all the bits used for the "small" representation; this includes
116 // bits for the size as well as the element bits.
117 uintptr_t getSmallRawBits() const {
118 assert(isSmall())((isSmall()) ? static_cast<void> (0) : __assert_fail ("isSmall()"
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/ADT/SmallBitVector.h"
, 118, __PRETTY_FUNCTION__))
;
119 return X >> 1;
120 }
121
122 void setSmallRawBits(uintptr_t NewRawBits) {
123 assert(isSmall())((isSmall()) ? static_cast<void> (0) : __assert_fail ("isSmall()"
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/ADT/SmallBitVector.h"
, 123, __PRETTY_FUNCTION__))
;
124 X = (NewRawBits << 1) | uintptr_t(1);
125 }
126
127 // Return the size.
128 size_t getSmallSize() const { return getSmallRawBits() >> SmallNumDataBits; }
129
130 void setSmallSize(size_t Size) {
131 setSmallRawBits(getSmallBits() | (Size << SmallNumDataBits));
132 }
133
134 // Return the element bits.
135 uintptr_t getSmallBits() const {
136 return getSmallRawBits() & ~(~uintptr_t(0) << getSmallSize());
137 }
138
139 void setSmallBits(uintptr_t NewBits) {
140 setSmallRawBits((NewBits & ~(~uintptr_t(0) << getSmallSize())) |
141 (getSmallSize() << SmallNumDataBits));
142 }
143
144public:
145 /// Creates an empty bitvector.
146 SmallBitVector() = default;
147
148 /// Creates a bitvector of specified number of bits. All bits are initialized
149 /// to the specified value.
150 explicit SmallBitVector(unsigned s, bool t = false) {
151 if (s <= SmallNumDataBits)
16
Assuming 's' is > SmallNumDataBits
17
Taking false branch
152 switchToSmall(t ? ~uintptr_t(0) : 0, s);
153 else
154 switchToLarge(new BitVector(s, t));
18
Memory is allocated
155 }
156
157 /// SmallBitVector copy ctor.
158 SmallBitVector(const SmallBitVector &RHS) {
159 if (RHS.isSmall())
160 X = RHS.X;
161 else
162 switchToLarge(new BitVector(*RHS.getPointer()));
163 }
164
165 SmallBitVector(SmallBitVector &&RHS) : X(RHS.X) {
166 RHS.X = 1;
167 }
168
169 ~SmallBitVector() {
170 if (!isSmall())
171 delete getPointer();
172 }
173
174 using const_set_bits_iterator = const_set_bits_iterator_impl<SmallBitVector>;
175 using set_iterator = const_set_bits_iterator;
176
177 const_set_bits_iterator set_bits_begin() const {
178 return const_set_bits_iterator(*this);
179 }
180
181 const_set_bits_iterator set_bits_end() const {
182 return const_set_bits_iterator(*this, -1);
183 }
184
185 iterator_range<const_set_bits_iterator> set_bits() const {
186 return make_range(set_bits_begin(), set_bits_end());
187 }
188
189 /// Tests whether there are no bits in this bitvector.
190 bool empty() const {
191 return isSmall() ? getSmallSize() == 0 : getPointer()->empty();
192 }
193
194 /// Returns the number of bits in this bitvector.
195 size_t size() const {
196 return isSmall() ? getSmallSize() : getPointer()->size();
197 }
198
199 /// Returns the number of bits which are set.
200 size_type count() const {
201 if (isSmall()) {
202 uintptr_t Bits = getSmallBits();
203 return countPopulation(Bits);
204 }
205 return getPointer()->count();
206 }
207
208 /// Returns true if any bit is set.
209 bool any() const {
210 if (isSmall())
211 return getSmallBits() != 0;
212 return getPointer()->any();
213 }
214
215 /// Returns true if all bits are set.
216 bool all() const {
217 if (isSmall())
218 return getSmallBits() == (uintptr_t(1) << getSmallSize()) - 1;
219 return getPointer()->all();
220 }
221
222 /// Returns true if none of the bits are set.
223 bool none() const {
224 if (isSmall())
225 return getSmallBits() == 0;
226 return getPointer()->none();
227 }
228
229 /// Returns the index of the first set bit, -1 if none of the bits are set.
230 int find_first() const {
231 if (isSmall()) {
232 uintptr_t Bits = getSmallBits();
233 if (Bits == 0)
234 return -1;
235 return countTrailingZeros(Bits);
236 }
237 return getPointer()->find_first();
238 }
239
240 int find_last() const {
241 if (isSmall()) {
242 uintptr_t Bits = getSmallBits();
243 if (Bits == 0)
244 return -1;
245 return NumBaseBits - countLeadingZeros(Bits);
246 }
247 return getPointer()->find_last();
248 }
249
250 /// Returns the index of the first unset bit, -1 if all of the bits are set.
251 int find_first_unset() const {
252 if (isSmall()) {
253 if (count() == getSmallSize())
254 return -1;
255
256 uintptr_t Bits = getSmallBits();
257 return countTrailingOnes(Bits);
258 }
259 return getPointer()->find_first_unset();
260 }
261
262 int find_last_unset() const {
263 if (isSmall()) {
264 if (count() == getSmallSize())
265 return -1;
266
267 uintptr_t Bits = getSmallBits();
268 return NumBaseBits - countLeadingOnes(Bits);
269 }
270 return getPointer()->find_last_unset();
271 }
272
273 /// Returns the index of the next set bit following the "Prev" bit.
274 /// Returns -1 if the next set bit is not found.
275 int find_next(unsigned Prev) const {
276 if (isSmall()) {
277 uintptr_t Bits = getSmallBits();
278 // Mask off previous bits.
279 Bits &= ~uintptr_t(0) << (Prev + 1);
280 if (Bits == 0 || Prev + 1 >= getSmallSize())
281 return -1;
282 return countTrailingZeros(Bits);
283 }
284 return getPointer()->find_next(Prev);
285 }
286
287 /// Returns the index of the next unset bit following the "Prev" bit.
288 /// Returns -1 if the next unset bit is not found.
289 int find_next_unset(unsigned Prev) const {
290 if (isSmall()) {
291 ++Prev;
292 uintptr_t Bits = getSmallBits();
293 // Mask in previous bits.
294 uintptr_t Mask = (1 << Prev) - 1;
295 Bits |= Mask;
296
297 if (Bits == ~uintptr_t(0) || Prev + 1 >= getSmallSize())
298 return -1;
299 return countTrailingOnes(Bits);
300 }
301 return getPointer()->find_next_unset(Prev);
302 }
303
304 /// find_prev - Returns the index of the first set bit that precedes the
305 /// the bit at \p PriorTo. Returns -1 if all previous bits are unset.
306 int find_prev(unsigned PriorTo) const {
307 if (isSmall()) {
308 if (PriorTo == 0)
309 return -1;
310
311 --PriorTo;
312 uintptr_t Bits = getSmallBits();