1 //===-- TemplateBase.h - Core classes for 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.
8 //===----------------------------------------------------------------------===//
10 // This file provides definitions which are common for all kinds of
11 // template representation.
13 //===----------------------------------------------------------------------===//
15 #ifndef LLVM_CLANG_AST_TEMPLATEBASE_H
16 #define LLVM_CLANG_AST_TEMPLATEBASE_H
18 #include "clang/AST/TemplateName.h"
19 #include "clang/AST/Type.h"
20 #include "llvm/ADT/APSInt.h"
21 #include "llvm/ADT/SmallVector.h"
22 #include "llvm/ADT/iterator_range.h"
23 #include "llvm/Support/Compiler.h"
24 #include "llvm/Support/ErrorHandling.h"
25 #include "llvm/Support/TrailingObjects.h"
28 class FoldingSetNodeID;
33 class DiagnosticBuilder;
35 struct PrintingPolicy;
39 /// \brief Represents a template argument.
40 class TemplateArgument {
42 /// \brief The kind of template argument we're storing.
44 /// \brief Represents an empty template argument, e.g., one that has not
47 /// The template argument is a type.
49 /// The template argument is a declaration that was provided for a pointer,
50 /// reference, or pointer to member non-type template parameter.
52 /// The template argument is a null pointer or null pointer to member that
53 /// was provided for a non-type template parameter.
55 /// The template argument is an integral value stored in an llvm::APSInt
56 /// that was provided for an integral non-type template parameter.
58 /// The template argument is a template name that was provided for a
59 /// template template parameter.
61 /// The template argument is a pack expansion of a template name that was
62 /// provided for a template template parameter.
64 /// The template argument is an expression, and we've not resolved it to one
65 /// of the other forms yet, either because it's dependent or because we're
66 /// representing a non-canonical template argument (for instance, in a
67 /// TemplateSpecializationType). Also used to represent a non-dependent
68 /// __uuidof expression (a Microsoft extension).
70 /// The template argument is actually a parameter pack. Arguments are stored
71 /// in the Args struct.
76 /// \brief The kind of template argument we're storing.
85 // We store a decomposed APSInt with the data allocated by ASTContext if
86 // BitWidth > 64. The memory may be shared between multiple
87 // TemplateArgument instances.
88 unsigned BitWidth : 31;
89 unsigned IsUnsigned : 1;
91 uint64_t VAL; ///< Used to store the <= 64 bits integer value.
92 const uint64_t *pVal; ///< Used to store the >64 bits integer value.
99 const TemplateArgument *Args;
103 unsigned NumExpansions;
114 struct TA TemplateArg;
115 struct TV TypeOrValue;
118 TemplateArgument(TemplateName, bool) = delete;
121 /// \brief Construct an empty, invalid template argument.
123 TypeOrValue.Kind = Null;
127 /// \brief Construct a template type argument.
128 TemplateArgument(QualType T, bool isNullPtr = false) {
129 TypeOrValue.Kind = isNullPtr ? NullPtr : Type;
130 TypeOrValue.V = reinterpret_cast<uintptr_t>(T.getAsOpaquePtr());
133 /// \brief Construct a template argument that refers to a
134 /// declaration, which is either an external declaration or a
135 /// template declaration.
136 TemplateArgument(ValueDecl *D, QualType QT) {
137 assert(D && "Expected decl");
138 DeclArg.Kind = Declaration;
139 DeclArg.QT = QT.getAsOpaquePtr();
143 /// \brief Construct an integral constant template argument. The memory to
144 /// store the value is allocated with Ctx.
145 TemplateArgument(ASTContext &Ctx, const llvm::APSInt &Value, QualType Type);
147 /// \brief Construct an integral constant template argument with the same
148 /// value as Other but a different type.
149 TemplateArgument(const TemplateArgument &Other, QualType Type) {
150 Integer = Other.Integer;
151 Integer.Type = Type.getAsOpaquePtr();
154 /// \brief Construct a template argument that is a template.
156 /// This form of template argument is generally used for template template
157 /// parameters. However, the template name could be a dependent template
158 /// name that ends up being instantiated to a function template whose address
161 /// \param Name The template name.
162 TemplateArgument(TemplateName Name) {
163 TemplateArg.Kind = Template;
164 TemplateArg.Name = Name.getAsVoidPointer();
165 TemplateArg.NumExpansions = 0;
168 /// \brief Construct a template argument that is a template pack expansion.
170 /// This form of template argument is generally used for template template
171 /// parameters. However, the template name could be a dependent template
172 /// name that ends up being instantiated to a function template whose address
175 /// \param Name The template name.
177 /// \param NumExpansions The number of expansions that will be generated by
179 TemplateArgument(TemplateName Name, Optional<unsigned> NumExpansions) {
180 TemplateArg.Kind = TemplateExpansion;
181 TemplateArg.Name = Name.getAsVoidPointer();
183 TemplateArg.NumExpansions = *NumExpansions + 1;
185 TemplateArg.NumExpansions = 0;
188 /// \brief Construct a template argument that is an expression.
190 /// This form of template argument only occurs in template argument
191 /// lists used for dependent types and for expression; it will not
192 /// occur in a non-dependent, canonical template argument list.
193 TemplateArgument(Expr *E) {
194 TypeOrValue.Kind = Expression;
195 TypeOrValue.V = reinterpret_cast<uintptr_t>(E);
198 /// \brief Construct a template argument that is a template argument pack.
200 /// We assume that storage for the template arguments provided
201 /// outlives the TemplateArgument itself.
202 explicit TemplateArgument(ArrayRef<TemplateArgument> Args) {
203 this->Args.Kind = Pack;
204 this->Args.Args = Args.data();
205 this->Args.NumArgs = Args.size();
208 static TemplateArgument getEmptyPack() { return TemplateArgument(None); }
210 /// \brief Create a new template argument pack by copying the given set of
211 /// template arguments.
212 static TemplateArgument CreatePackCopy(ASTContext &Context,
213 ArrayRef<TemplateArgument> Args);
215 /// \brief Return the kind of stored template argument.
216 ArgKind getKind() const { return (ArgKind)TypeOrValue.Kind; }
218 /// \brief Determine whether this template argument has no value.
219 bool isNull() const { return getKind() == Null; }
221 /// \brief Whether this template argument is dependent on a template
222 /// parameter such that its result can change from one instantiation to
224 bool isDependent() const;
226 /// \brief Whether this template argument is dependent on a template
228 bool isInstantiationDependent() const;
230 /// \brief Whether this template argument contains an unexpanded
232 bool containsUnexpandedParameterPack() const;
234 /// \brief Determine whether this template argument is a pack expansion.
235 bool isPackExpansion() const;
237 /// \brief Retrieve the type for a type template argument.
238 QualType getAsType() const {
239 assert(getKind() == Type && "Unexpected kind");
240 return QualType::getFromOpaquePtr(reinterpret_cast<void*>(TypeOrValue.V));
243 /// \brief Retrieve the declaration for a declaration non-type
244 /// template argument.
245 ValueDecl *getAsDecl() const {
246 assert(getKind() == Declaration && "Unexpected kind");
250 QualType getParamTypeForDecl() const {
251 assert(getKind() == Declaration && "Unexpected kind");
252 return QualType::getFromOpaquePtr(DeclArg.QT);
255 /// \brief Retrieve the type for null non-type template argument.
256 QualType getNullPtrType() const {
257 assert(getKind() == NullPtr && "Unexpected kind");
258 return QualType::getFromOpaquePtr(reinterpret_cast<void*>(TypeOrValue.V));
261 /// \brief Retrieve the template name for a template name argument.
262 TemplateName getAsTemplate() const {
263 assert(getKind() == Template && "Unexpected kind");
264 return TemplateName::getFromVoidPointer(TemplateArg.Name);
267 /// \brief Retrieve the template argument as a template name; if the argument
268 /// is a pack expansion, return the pattern as a template name.
269 TemplateName getAsTemplateOrTemplatePattern() const {
270 assert((getKind() == Template || getKind() == TemplateExpansion) &&
273 return TemplateName::getFromVoidPointer(TemplateArg.Name);
276 /// \brief Retrieve the number of expansions that a template template argument
277 /// expansion will produce, if known.
278 Optional<unsigned> getNumTemplateExpansions() const;
280 /// \brief Retrieve the template argument as an integral value.
281 // FIXME: Provide a way to read the integral data without copying the value.
282 llvm::APSInt getAsIntegral() const {
283 assert(getKind() == Integral && "Unexpected kind");
284 using namespace llvm;
285 if (Integer.BitWidth <= 64)
286 return APSInt(APInt(Integer.BitWidth, Integer.VAL), Integer.IsUnsigned);
288 unsigned NumWords = APInt::getNumWords(Integer.BitWidth);
289 return APSInt(APInt(Integer.BitWidth, makeArrayRef(Integer.pVal, NumWords)),
293 /// \brief Retrieve the type of the integral value.
294 QualType getIntegralType() const {
295 assert(getKind() == Integral && "Unexpected kind");
296 return QualType::getFromOpaquePtr(Integer.Type);
299 void setIntegralType(QualType T) {
300 assert(getKind() == Integral && "Unexpected kind");
301 Integer.Type = T.getAsOpaquePtr();
304 /// \brief Retrieve the template argument as an expression.
305 Expr *getAsExpr() const {
306 assert(getKind() == Expression && "Unexpected kind");
307 return reinterpret_cast<Expr *>(TypeOrValue.V);
310 /// \brief Iterator that traverses the elements of a template argument pack.
311 typedef const TemplateArgument * pack_iterator;
313 /// \brief Iterator referencing the first argument of a template argument
315 pack_iterator pack_begin() const {
316 assert(getKind() == Pack);
320 /// \brief Iterator referencing one past the last argument of a template
322 pack_iterator pack_end() const {
323 assert(getKind() == Pack);
324 return Args.Args + Args.NumArgs;
327 /// \brief Iterator range referencing all of the elements of a template
329 llvm::iterator_range<pack_iterator> pack_elements() const {
330 return llvm::make_range(pack_begin(), pack_end());
333 /// \brief The number of template arguments in the given template argument
335 unsigned pack_size() const {
336 assert(getKind() == Pack);
340 /// \brief Return the array of arguments in this template argument pack.
341 ArrayRef<TemplateArgument> getPackAsArray() const {
342 assert(getKind() == Pack);
343 return llvm::makeArrayRef(Args.Args, Args.NumArgs);
346 /// \brief Determines whether two template arguments are superficially the
348 bool structurallyEquals(const TemplateArgument &Other) const;
350 /// \brief When the template argument is a pack expansion, returns
351 /// the pattern of the pack expansion.
352 TemplateArgument getPackExpansionPattern() const;
354 /// \brief Print this template argument to the given output stream.
355 void print(const PrintingPolicy &Policy, raw_ostream &Out) const;
357 /// \brief Used to insert TemplateArguments into FoldingSets.
358 void Profile(llvm::FoldingSetNodeID &ID, const ASTContext &Context) const;
361 /// Location information for a TemplateArgument.
362 struct TemplateArgumentLocInfo {
366 // FIXME: We'd like to just use the qualifier in the TemplateName,
367 // but template arguments get canonicalized too quickly.
368 NestedNameSpecifier *Qualifier;
369 void *QualifierLocData;
370 unsigned TemplateNameLoc;
371 unsigned EllipsisLoc;
377 TypeSourceInfo *Declarator;
381 TemplateArgumentLocInfo();
383 TemplateArgumentLocInfo(TypeSourceInfo *TInfo) : Declarator(TInfo) {}
385 TemplateArgumentLocInfo(Expr *E) : Expression(E) {}
387 TemplateArgumentLocInfo(NestedNameSpecifierLoc QualifierLoc,
388 SourceLocation TemplateNameLoc,
389 SourceLocation EllipsisLoc)
391 Template.Qualifier = QualifierLoc.getNestedNameSpecifier();
392 Template.QualifierLocData = QualifierLoc.getOpaqueData();
393 Template.TemplateNameLoc = TemplateNameLoc.getRawEncoding();
394 Template.EllipsisLoc = EllipsisLoc.getRawEncoding();
397 TypeSourceInfo *getAsTypeSourceInfo() const {
401 Expr *getAsExpr() const {
405 NestedNameSpecifierLoc getTemplateQualifierLoc() const {
406 return NestedNameSpecifierLoc(Template.Qualifier,
407 Template.QualifierLocData);
410 SourceLocation getTemplateNameLoc() const {
411 return SourceLocation::getFromRawEncoding(Template.TemplateNameLoc);
414 SourceLocation getTemplateEllipsisLoc() const {
415 return SourceLocation::getFromRawEncoding(Template.EllipsisLoc);
419 /// Location wrapper for a TemplateArgument. TemplateArgument is to
420 /// TemplateArgumentLoc as Type is to TypeLoc.
421 class TemplateArgumentLoc {
422 TemplateArgument Argument;
423 TemplateArgumentLocInfo LocInfo;
426 TemplateArgumentLoc() {}
428 TemplateArgumentLoc(const TemplateArgument &Argument,
429 TemplateArgumentLocInfo Opaque)
430 : Argument(Argument), LocInfo(Opaque) {
433 TemplateArgumentLoc(const TemplateArgument &Argument, TypeSourceInfo *TInfo)
434 : Argument(Argument), LocInfo(TInfo) {
435 assert(Argument.getKind() == TemplateArgument::Type);
438 TemplateArgumentLoc(const TemplateArgument &Argument, Expr *E)
439 : Argument(Argument), LocInfo(E) {
440 assert(Argument.getKind() == TemplateArgument::Expression);
443 TemplateArgumentLoc(const TemplateArgument &Argument,
444 NestedNameSpecifierLoc QualifierLoc,
445 SourceLocation TemplateNameLoc,
446 SourceLocation EllipsisLoc = SourceLocation())
447 : Argument(Argument), LocInfo(QualifierLoc, TemplateNameLoc, EllipsisLoc) {
448 assert(Argument.getKind() == TemplateArgument::Template ||
449 Argument.getKind() == TemplateArgument::TemplateExpansion);
452 /// \brief - Fetches the primary location of the argument.
453 SourceLocation getLocation() const {
454 if (Argument.getKind() == TemplateArgument::Template ||
455 Argument.getKind() == TemplateArgument::TemplateExpansion)
456 return getTemplateNameLoc();
458 return getSourceRange().getBegin();
461 /// \brief - Fetches the full source range of the argument.
462 SourceRange getSourceRange() const LLVM_READONLY;
464 const TemplateArgument &getArgument() const {
468 TemplateArgumentLocInfo getLocInfo() const {
472 TypeSourceInfo *getTypeSourceInfo() const {
473 assert(Argument.getKind() == TemplateArgument::Type);
474 return LocInfo.getAsTypeSourceInfo();
477 Expr *getSourceExpression() const {
478 assert(Argument.getKind() == TemplateArgument::Expression);
479 return LocInfo.getAsExpr();
482 Expr *getSourceDeclExpression() const {
483 assert(Argument.getKind() == TemplateArgument::Declaration);
484 return LocInfo.getAsExpr();
487 Expr *getSourceNullPtrExpression() const {
488 assert(Argument.getKind() == TemplateArgument::NullPtr);
489 return LocInfo.getAsExpr();
492 Expr *getSourceIntegralExpression() const {
493 assert(Argument.getKind() == TemplateArgument::Integral);
494 return LocInfo.getAsExpr();
497 NestedNameSpecifierLoc getTemplateQualifierLoc() const {
498 assert(Argument.getKind() == TemplateArgument::Template ||
499 Argument.getKind() == TemplateArgument::TemplateExpansion);
500 return LocInfo.getTemplateQualifierLoc();
503 SourceLocation getTemplateNameLoc() const {
504 assert(Argument.getKind() == TemplateArgument::Template ||
505 Argument.getKind() == TemplateArgument::TemplateExpansion);
506 return LocInfo.getTemplateNameLoc();
509 SourceLocation getTemplateEllipsisLoc() const {
510 assert(Argument.getKind() == TemplateArgument::TemplateExpansion);
511 return LocInfo.getTemplateEllipsisLoc();
515 /// A convenient class for passing around template argument
516 /// information. Designed to be passed by reference.
517 class TemplateArgumentListInfo {
518 SmallVector<TemplateArgumentLoc, 8> Arguments;
519 SourceLocation LAngleLoc;
520 SourceLocation RAngleLoc;
522 // This can leak if used in an AST node, use ASTTemplateArgumentListInfo
524 void *operator new(size_t bytes, ASTContext &C) = delete;
527 TemplateArgumentListInfo() {}
529 TemplateArgumentListInfo(SourceLocation LAngleLoc,
530 SourceLocation RAngleLoc)
531 : LAngleLoc(LAngleLoc), RAngleLoc(RAngleLoc) {}
533 SourceLocation getLAngleLoc() const { return LAngleLoc; }
534 SourceLocation getRAngleLoc() const { return RAngleLoc; }
536 void setLAngleLoc(SourceLocation Loc) { LAngleLoc = Loc; }
537 void setRAngleLoc(SourceLocation Loc) { RAngleLoc = Loc; }
539 unsigned size() const { return Arguments.size(); }
541 const TemplateArgumentLoc *getArgumentArray() const {
542 return Arguments.data();
545 llvm::ArrayRef<TemplateArgumentLoc> arguments() const {
549 const TemplateArgumentLoc &operator[](unsigned I) const {
553 TemplateArgumentLoc &operator[](unsigned I) {
557 void addArgument(const TemplateArgumentLoc &Loc) {
558 Arguments.push_back(Loc);
562 /// \brief Represents an explicit template argument list in C++, e.g.,
563 /// the "<int>" in "sort<int>".
564 /// This is safe to be used inside an AST node, in contrast with
565 /// TemplateArgumentListInfo.
566 struct ASTTemplateArgumentListInfo final
567 : private llvm::TrailingObjects<ASTTemplateArgumentListInfo,
568 TemplateArgumentLoc> {
570 friend TrailingObjects;
572 ASTTemplateArgumentListInfo(const TemplateArgumentListInfo &List);
575 /// \brief The source location of the left angle bracket ('<').
576 SourceLocation LAngleLoc;
578 /// \brief The source location of the right angle bracket ('>').
579 SourceLocation RAngleLoc;
581 /// \brief The number of template arguments in TemplateArgs.
582 unsigned NumTemplateArgs;
584 /// \brief Retrieve the template arguments
585 const TemplateArgumentLoc *getTemplateArgs() const {
586 return getTrailingObjects<TemplateArgumentLoc>();
589 const TemplateArgumentLoc &operator[](unsigned I) const {
590 return getTemplateArgs()[I];
593 static const ASTTemplateArgumentListInfo *
594 Create(ASTContext &C, const TemplateArgumentListInfo &List);
597 /// \brief Represents an explicit template argument list in C++, e.g.,
598 /// the "<int>" in "sort<int>".
600 /// It is intended to be used as a trailing object on AST nodes, and
601 /// as such, doesn't contain the array of TemplateArgumentLoc itself,
602 /// but expects the containing object to also provide storage for
604 struct LLVM_ALIGNAS(LLVM_PTR_SIZE) ASTTemplateKWAndArgsInfo {
605 /// \brief The source location of the left angle bracket ('<').
606 SourceLocation LAngleLoc;
608 /// \brief The source location of the right angle bracket ('>').
609 SourceLocation RAngleLoc;
611 /// \brief The source location of the template keyword; this is used
612 /// as part of the representation of qualified identifiers, such as
613 /// S<T>::template apply<T>. Will be empty if this expression does
614 /// not have a template keyword.
615 SourceLocation TemplateKWLoc;
617 /// \brief The number of template arguments in TemplateArgs.
618 unsigned NumTemplateArgs;
620 void initializeFrom(SourceLocation TemplateKWLoc,
621 const TemplateArgumentListInfo &List,
622 TemplateArgumentLoc *OutArgArray);
623 void initializeFrom(SourceLocation TemplateKWLoc,
624 const TemplateArgumentListInfo &List,
625 TemplateArgumentLoc *OutArgArray, bool &Dependent,
626 bool &InstantiationDependent,
627 bool &ContainsUnexpandedParameterPack);
628 void initializeFrom(SourceLocation TemplateKWLoc);
630 void copyInto(const TemplateArgumentLoc *ArgArray,
631 TemplateArgumentListInfo &List) const;
634 const DiagnosticBuilder &operator<<(const DiagnosticBuilder &DB,
635 const TemplateArgument &Arg);
637 inline TemplateSpecializationType::iterator
638 TemplateSpecializationType::end() const {
639 return getArgs() + getNumArgs();
642 inline DependentTemplateSpecializationType::iterator
643 DependentTemplateSpecializationType::end() const {
644 return getArgs() + getNumArgs();
647 inline const TemplateArgument &
648 TemplateSpecializationType::getArg(unsigned Idx) const {
649 assert(Idx < getNumArgs() && "Template argument out of range");
650 return getArgs()[Idx];
653 inline const TemplateArgument &
654 DependentTemplateSpecializationType::getArg(unsigned Idx) const {
655 assert(Idx < getNumArgs() && "Template argument out of range");
656 return getArgs()[Idx];
659 } // end namespace clang