1 //===------- SemaTemplate.h - C++ Templates ---------------------*- C++ -*-===/
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //===----------------------------------------------------------------------===/
9 // This file provides types used in the semantic analysis of C++ templates.
11 //===----------------------------------------------------------------------===/
12 #ifndef LLVM_CLANG_SEMA_TEMPLATE_H
13 #define LLVM_CLANG_SEMA_TEMPLATE_H
15 #include "clang/AST/DeclTemplate.h"
16 #include "clang/AST/DeclVisitor.h"
17 #include "clang/Sema/Sema.h"
18 #include "llvm/ADT/SmallVector.h"
23 /// \brief Data structure that captures multiple levels of template argument
24 /// lists for use in template instantiation.
26 /// Multiple levels of template arguments occur when instantiating the
27 /// definitions of member templates. For example:
30 /// template<typename T>
39 /// When instantiating X<int>::Y<17>::f, the multi-level template argument
40 /// list will contain a template argument list (int) at depth 0 and a
41 /// template argument list (17) at depth 1.
42 class MultiLevelTemplateArgumentList {
43 /// \brief The template argument list at a certain template depth
44 typedef ArrayRef<TemplateArgument> ArgList;
46 /// \brief The template argument lists, stored from the innermost template
47 /// argument list (first) to the outermost template argument list (last).
48 SmallVector<ArgList, 4> TemplateArgumentLists;
51 /// \brief Construct an empty set of template argument lists.
52 MultiLevelTemplateArgumentList() { }
54 /// \brief Construct a single-level template argument list.
56 MultiLevelTemplateArgumentList(const TemplateArgumentList &TemplateArgs) {
57 addOuterTemplateArguments(&TemplateArgs);
60 /// \brief Determine the number of levels in this template argument
62 unsigned getNumLevels() const { return TemplateArgumentLists.size(); }
64 /// \brief Retrieve the template argument at a given depth and index.
65 const TemplateArgument &operator()(unsigned Depth, unsigned Index) const {
66 assert(Depth < TemplateArgumentLists.size());
67 assert(Index < TemplateArgumentLists[getNumLevels() - Depth - 1].size());
68 return TemplateArgumentLists[getNumLevels() - Depth - 1][Index];
71 /// \brief Determine whether there is a non-NULL template argument at the
72 /// given depth and index.
74 /// There must exist a template argument list at the given depth.
75 bool hasTemplateArgument(unsigned Depth, unsigned Index) const {
76 assert(Depth < TemplateArgumentLists.size());
78 if (Index >= TemplateArgumentLists[getNumLevels() - Depth - 1].size())
81 return !(*this)(Depth, Index).isNull();
84 /// \brief Clear out a specific template argument.
85 void setArgument(unsigned Depth, unsigned Index,
86 TemplateArgument Arg) {
87 assert(Depth < TemplateArgumentLists.size());
88 assert(Index < TemplateArgumentLists[getNumLevels() - Depth - 1].size());
89 const_cast<TemplateArgument&>(
90 TemplateArgumentLists[getNumLevels() - Depth - 1][Index])
94 /// \brief Add a new outermost level to the multi-level template argument
96 void addOuterTemplateArguments(const TemplateArgumentList *TemplateArgs) {
97 addOuterTemplateArguments(ArgList(TemplateArgs->data(),
98 TemplateArgs->size()));
101 /// \brief Add a new outmost level to the multi-level template argument
103 void addOuterTemplateArguments(const TemplateArgument *Args,
105 addOuterTemplateArguments(ArgList(Args, NumArgs));
108 /// \brief Add a new outmost level to the multi-level template argument
110 void addOuterTemplateArguments(ArgList Args) {
111 TemplateArgumentLists.push_back(Args);
114 /// \brief Retrieve the innermost template argument list.
115 const ArgList &getInnermost() const {
116 return TemplateArgumentLists.front();
120 /// \brief The context in which partial ordering of function templates occurs.
122 /// \brief Partial ordering of function templates for a function call.
124 /// \brief Partial ordering of function templates for a call to a
125 /// conversion function.
127 /// \brief Partial ordering of function templates in other contexts, e.g.,
128 /// taking the address of a function template or matching a function
129 /// template specialization to a function template.
133 // This is lame but unavoidable in a world without forward
134 // declarations of enums. The alternatives are to either pollute
135 // Sema.h (by including this file) or sacrifice type safety (by
136 // making Sema.h declare things as enums).
137 class TemplatePartialOrderingContext {
140 TemplatePartialOrderingContext(TPOC Value) : Value(Value) {}
141 operator TPOC() const { return Value; }
144 /// \brief Captures a template argument whose value has been deduced
145 /// via c++ template argument deduction.
146 class DeducedTemplateArgument : public TemplateArgument {
147 /// \brief For a non-type template argument, whether the value was
148 /// deduced from an array bound.
149 bool DeducedFromArrayBound;
152 DeducedTemplateArgument()
153 : TemplateArgument(), DeducedFromArrayBound(false) { }
155 DeducedTemplateArgument(const TemplateArgument &Arg,
156 bool DeducedFromArrayBound = false)
157 : TemplateArgument(Arg), DeducedFromArrayBound(DeducedFromArrayBound) { }
159 /// \brief Construct an integral non-type template argument that
160 /// has been deduced, possibly from an array bound.
161 DeducedTemplateArgument(ASTContext &Ctx,
162 const llvm::APSInt &Value,
164 bool DeducedFromArrayBound)
165 : TemplateArgument(Ctx, Value, ValueType),
166 DeducedFromArrayBound(DeducedFromArrayBound) { }
168 /// \brief For a non-type template argument, determine whether the
169 /// template argument was deduced from an array bound.
170 bool wasDeducedFromArrayBound() const { return DeducedFromArrayBound; }
172 /// \brief Specify whether the given non-type template argument
173 /// was deduced from an array bound.
174 void setDeducedFromArrayBound(bool Deduced) {
175 DeducedFromArrayBound = Deduced;
179 /// \brief A stack-allocated class that identifies which local
180 /// variable declaration instantiations are present in this scope.
182 /// A new instance of this class type will be created whenever we
183 /// instantiate a new function declaration, which will have its own
184 /// set of parameter declarations.
185 class LocalInstantiationScope {
187 /// \brief A set of declarations.
188 typedef SmallVector<Decl *, 4> DeclArgumentPack;
191 /// \brief Reference to the semantic analysis that is performing
192 /// this template instantiation.
195 typedef llvm::SmallDenseMap<
196 const Decl *, llvm::PointerUnion<Decl *, DeclArgumentPack *>, 4>
199 /// \brief A mapping from local declarations that occur
200 /// within a template to their instantiations.
202 /// This mapping is used during instantiation to keep track of,
203 /// e.g., function parameter and variable declarations. For example,
207 /// template<typename T> T add(T x, T y) { return x + y; }
210 /// when we instantiate add<int>, we will introduce a mapping from
211 /// the ParmVarDecl for 'x' that occurs in the template to the
212 /// instantiated ParmVarDecl for 'x'.
214 /// For a parameter pack, the local instantiation scope may contain a
215 /// set of instantiated parameters. This is stored as a DeclArgumentPack
217 LocalDeclsMap LocalDecls;
219 /// \brief The set of argument packs we've allocated.
220 SmallVector<DeclArgumentPack *, 1> ArgumentPacks;
222 /// \brief The outer scope, which contains local variable
223 /// definitions from some other instantiation (that may not be
224 /// relevant to this particular scope).
225 LocalInstantiationScope *Outer;
227 /// \brief Whether we have already exited this scope.
230 /// \brief Whether to combine this scope with the outer scope, such that
231 /// lookup will search our outer scope.
232 bool CombineWithOuterScope;
234 /// \brief If non-NULL, the template parameter pack that has been
235 /// partially substituted per C++0x [temp.arg.explicit]p9.
236 NamedDecl *PartiallySubstitutedPack;
238 /// \brief If \c PartiallySubstitutedPack is non-null, the set of
239 /// explicitly-specified template arguments in that pack.
240 const TemplateArgument *ArgsInPartiallySubstitutedPack;
242 /// \brief If \c PartiallySubstitutedPack, the number of
243 /// explicitly-specified template arguments in
244 /// ArgsInPartiallySubstitutedPack.
245 unsigned NumArgsInPartiallySubstitutedPack;
247 // This class is non-copyable
248 LocalInstantiationScope(
249 const LocalInstantiationScope &) LLVM_DELETED_FUNCTION;
250 void operator=(const LocalInstantiationScope &) LLVM_DELETED_FUNCTION;
253 LocalInstantiationScope(Sema &SemaRef, bool CombineWithOuterScope = false)
254 : SemaRef(SemaRef), Outer(SemaRef.CurrentInstantiationScope),
255 Exited(false), CombineWithOuterScope(CombineWithOuterScope),
256 PartiallySubstitutedPack(0)
258 SemaRef.CurrentInstantiationScope = this;
261 ~LocalInstantiationScope() {
265 const Sema &getSema() const { return SemaRef; }
267 /// \brief Exit this local instantiation scope early.
272 for (unsigned I = 0, N = ArgumentPacks.size(); I != N; ++I)
273 delete ArgumentPacks[I];
275 SemaRef.CurrentInstantiationScope = Outer;
279 /// \brief Clone this scope, and all outer scopes, down to the given
281 LocalInstantiationScope *cloneScopes(LocalInstantiationScope *Outermost) {
282 if (this == Outermost) return this;
283 LocalInstantiationScope *newScope =
284 new LocalInstantiationScope(SemaRef, CombineWithOuterScope);
288 newScope->Outer = Outer->cloneScopes(Outermost);
290 newScope->PartiallySubstitutedPack = PartiallySubstitutedPack;
291 newScope->ArgsInPartiallySubstitutedPack = ArgsInPartiallySubstitutedPack;
292 newScope->NumArgsInPartiallySubstitutedPack =
293 NumArgsInPartiallySubstitutedPack;
295 for (LocalDeclsMap::iterator I = LocalDecls.begin(), E = LocalDecls.end();
297 const Decl *D = I->first;
298 llvm::PointerUnion<Decl *, DeclArgumentPack *> &Stored =
299 newScope->LocalDecls[D];
300 if (I->second.is<Decl *>()) {
301 Stored = I->second.get<Decl *>();
303 DeclArgumentPack *OldPack = I->second.get<DeclArgumentPack *>();
304 DeclArgumentPack *NewPack = new DeclArgumentPack(*OldPack);
306 newScope->ArgumentPacks.push_back(NewPack);
312 /// \brief deletes the given scope, and all otuer scopes, down to the
313 /// given outermost scope.
314 static void deleteScopes(LocalInstantiationScope *Scope,
315 LocalInstantiationScope *Outermost) {
316 while (Scope && Scope != Outermost) {
317 LocalInstantiationScope *Out = Scope->Outer;
323 /// \brief Find the instantiation of the declaration D within the current
324 /// instantiation scope.
326 /// \param D The declaration whose instantiation we are searching for.
328 /// \returns A pointer to the declaration or argument pack of declarations
329 /// to which the declaration \c D is instantiataed, if found. Otherwise,
331 llvm::PointerUnion<Decl *, DeclArgumentPack *> *
332 findInstantiationOf(const Decl *D);
334 void InstantiatedLocal(const Decl *D, Decl *Inst);
335 void InstantiatedLocalPackArg(const Decl *D, Decl *Inst);
336 void MakeInstantiatedLocalArgPack(const Decl *D);
338 /// \brief Note that the given parameter pack has been partially substituted
339 /// via explicit specification of template arguments
340 /// (C++0x [temp.arg.explicit]p9).
342 /// \param Pack The parameter pack, which will always be a template
345 /// \param ExplicitArgs The explicitly-specified template arguments provided
346 /// for this parameter pack.
348 /// \param NumExplicitArgs The number of explicitly-specified template
349 /// arguments provided for this parameter pack.
350 void SetPartiallySubstitutedPack(NamedDecl *Pack,
351 const TemplateArgument *ExplicitArgs,
352 unsigned NumExplicitArgs);
354 /// \brief Reset the partially-substituted pack when it is no longer of
356 void ResetPartiallySubstitutedPack() {
357 assert(PartiallySubstitutedPack && "No partially-substituted pack");
358 PartiallySubstitutedPack = 0;
359 ArgsInPartiallySubstitutedPack = 0;
360 NumArgsInPartiallySubstitutedPack = 0;
363 /// \brief Retrieve the partially-substitued template parameter pack.
365 /// If there is no partially-substituted parameter pack, returns NULL.
366 NamedDecl *getPartiallySubstitutedPack(
367 const TemplateArgument **ExplicitArgs = 0,
368 unsigned *NumExplicitArgs = 0) const;
371 class TemplateDeclInstantiator
372 : public DeclVisitor<TemplateDeclInstantiator, Decl *>
375 Sema::ArgumentPackSubstitutionIndexRAII SubstIndex;
377 const MultiLevelTemplateArgumentList &TemplateArgs;
378 Sema::LateInstantiatedAttrVec* LateAttrs;
379 LocalInstantiationScope *StartingScope;
381 /// \brief A list of out-of-line class template partial
382 /// specializations that will need to be instantiated after the
383 /// enclosing class's instantiation is complete.
384 SmallVector<std::pair<ClassTemplateDecl *,
385 ClassTemplatePartialSpecializationDecl *>, 4>
386 OutOfLinePartialSpecs;
389 TemplateDeclInstantiator(Sema &SemaRef, DeclContext *Owner,
390 const MultiLevelTemplateArgumentList &TemplateArgs)
392 SubstIndex(SemaRef, SemaRef.ArgumentPackSubstitutionIndex),
393 Owner(Owner), TemplateArgs(TemplateArgs), LateAttrs(0), StartingScope(0)
396 // FIXME: Once we get closer to completion, replace these manually-written
397 // declarations with automatically-generated ones from
398 // clang/AST/DeclNodes.inc.
399 Decl *VisitTranslationUnitDecl(TranslationUnitDecl *D);
400 Decl *VisitLabelDecl(LabelDecl *D);
401 Decl *VisitNamespaceDecl(NamespaceDecl *D);
402 Decl *VisitNamespaceAliasDecl(NamespaceAliasDecl *D);
403 Decl *VisitTypedefDecl(TypedefDecl *D);
404 Decl *VisitTypeAliasDecl(TypeAliasDecl *D);
405 Decl *VisitTypeAliasTemplateDecl(TypeAliasTemplateDecl *D);
406 Decl *VisitVarDecl(VarDecl *D);
407 Decl *VisitAccessSpecDecl(AccessSpecDecl *D);
408 Decl *VisitFieldDecl(FieldDecl *D);
409 Decl *VisitMSPropertyDecl(MSPropertyDecl *D);
410 Decl *VisitIndirectFieldDecl(IndirectFieldDecl *D);
411 Decl *VisitStaticAssertDecl(StaticAssertDecl *D);
412 Decl *VisitEnumDecl(EnumDecl *D);
413 Decl *VisitEnumConstantDecl(EnumConstantDecl *D);
414 Decl *VisitFriendDecl(FriendDecl *D);
415 Decl *VisitFunctionDecl(FunctionDecl *D,
416 TemplateParameterList *TemplateParams = 0);
417 Decl *VisitCXXRecordDecl(CXXRecordDecl *D);
418 Decl *VisitCXXMethodDecl(CXXMethodDecl *D,
419 TemplateParameterList *TemplateParams = 0,
420 bool IsClassScopeSpecialization = false);
421 Decl *VisitCXXConstructorDecl(CXXConstructorDecl *D);
422 Decl *VisitCXXDestructorDecl(CXXDestructorDecl *D);
423 Decl *VisitCXXConversionDecl(CXXConversionDecl *D);
424 ParmVarDecl *VisitParmVarDecl(ParmVarDecl *D);
425 Decl *VisitClassTemplateDecl(ClassTemplateDecl *D);
426 Decl *VisitClassTemplatePartialSpecializationDecl(
427 ClassTemplatePartialSpecializationDecl *D);
428 Decl *VisitFunctionTemplateDecl(FunctionTemplateDecl *D);
429 Decl *VisitTemplateTypeParmDecl(TemplateTypeParmDecl *D);
430 Decl *VisitNonTypeTemplateParmDecl(NonTypeTemplateParmDecl *D);
431 Decl *VisitTemplateTemplateParmDecl(TemplateTemplateParmDecl *D);
432 Decl *VisitUsingDirectiveDecl(UsingDirectiveDecl *D);
433 Decl *VisitUsingDecl(UsingDecl *D);
434 Decl *VisitUsingShadowDecl(UsingShadowDecl *D);
435 Decl *VisitUnresolvedUsingValueDecl(UnresolvedUsingValueDecl *D);
436 Decl *VisitUnresolvedUsingTypenameDecl(UnresolvedUsingTypenameDecl *D);
437 Decl *VisitClassScopeFunctionSpecializationDecl(
438 ClassScopeFunctionSpecializationDecl *D);
439 Decl *VisitOMPThreadPrivateDecl(OMPThreadPrivateDecl *D);
441 // Base case. FIXME: Remove once we can instantiate everything.
442 Decl *VisitDecl(Decl *D) {
443 unsigned DiagID = SemaRef.getDiagnostics().getCustomDiagID(
444 DiagnosticsEngine::Error,
445 "cannot instantiate %0 yet");
446 SemaRef.Diag(D->getLocation(), DiagID)
447 << D->getDeclKindName();
452 // Enable late instantiation of attributes. Late instantiated attributes
453 // will be stored in LA.
454 void enableLateAttributeInstantiation(Sema::LateInstantiatedAttrVec *LA) {
456 StartingScope = SemaRef.CurrentInstantiationScope;
459 // Disable late instantiation of attributes.
460 void disableLateAttributeInstantiation() {
465 LocalInstantiationScope *getStartingScope() const { return StartingScope; }
468 SmallVectorImpl<std::pair<ClassTemplateDecl *,
469 ClassTemplatePartialSpecializationDecl *> >
471 delayed_partial_spec_iterator;
473 /// \brief Return an iterator to the beginning of the set of
474 /// "delayed" partial specializations, which must be passed to
475 /// InstantiateClassTemplatePartialSpecialization once the class
476 /// definition has been completed.
477 delayed_partial_spec_iterator delayed_partial_spec_begin() {
478 return OutOfLinePartialSpecs.begin();
481 /// \brief Return an iterator to the end of the set of
482 /// "delayed" partial specializations, which must be passed to
483 /// InstantiateClassTemplatePartialSpecialization once the class
484 /// definition has been completed.
485 delayed_partial_spec_iterator delayed_partial_spec_end() {
486 return OutOfLinePartialSpecs.end();
489 // Helper functions for instantiating methods.
490 TypeSourceInfo *SubstFunctionType(FunctionDecl *D,
491 SmallVectorImpl<ParmVarDecl *> &Params);
492 bool InitFunctionInstantiation(FunctionDecl *New, FunctionDecl *Tmpl);
493 bool InitMethodInstantiation(CXXMethodDecl *New, CXXMethodDecl *Tmpl);
495 TemplateParameterList *
496 SubstTemplateParams(TemplateParameterList *List);
498 bool SubstQualifier(const DeclaratorDecl *OldDecl,
499 DeclaratorDecl *NewDecl);
500 bool SubstQualifier(const TagDecl *OldDecl,
503 Decl *InstantiateTypedefNameDecl(TypedefNameDecl *D, bool IsTypeAlias);
504 ClassTemplatePartialSpecializationDecl *
505 InstantiateClassTemplatePartialSpecialization(
506 ClassTemplateDecl *ClassTemplate,
507 ClassTemplatePartialSpecializationDecl *PartialSpec);
508 void InstantiateEnumDefinition(EnumDecl *Enum, EnumDecl *Pattern);
512 #endif // LLVM_CLANG_SEMA_TEMPLATE_H