path: root/include/clang/AST/DeclTemplate.h

//===-- DeclTemplate.h - Classes for representing C++ templates -*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
//  This file defines the C++ template declaration subclasses.
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_CLANG_AST_DECLTEMPLATE_H
#define LLVM_CLANG_AST_DECLTEMPLATE_H

#include "clang/AST/DeclCXX.h"
#include "llvm/ADT/APSInt.h"
#include "llvm/ADT/FoldingSet.h"
#include "llvm/ADT/PointerUnion.h"
#include <limits>

namespace clang {

class TemplateParameterList;
class TemplateDecl;
class FunctionTemplateDecl;
class ClassTemplateDecl;
class ClassTemplatePartialSpecializationDecl;
class TemplateTypeParmDecl;
class NonTypeTemplateParmDecl;
class TemplateTemplateParmDecl;

/// \brief Stores a template parameter of any kind.
typedef llvm::PointerUnion3<TemplateTypeParmDecl*, NonTypeTemplateParmDecl*,
                            TemplateTemplateParmDecl*> TemplateParameter;

/// TemplateParameterList - Stores a list of template parameters for a
/// TemplateDecl and its derived classes.
class TemplateParameterList {
  /// The location of the 'template' keyword.
  SourceLocation TemplateLoc;

  /// The locations of the '<' and '>' angle brackets.
  SourceLocation LAngleLoc, RAngleLoc;

  /// The number of template parameters in this template
  /// parameter list.
  unsigned NumParams;

  TemplateParameterList(SourceLocation TemplateLoc, SourceLocation LAngleLoc,
                        Decl **Params, unsigned NumParams,
                        SourceLocation RAngleLoc);

public:
  static TemplateParameterList *Create(ASTContext &C, 
                                       SourceLocation TemplateLoc,
                                       SourceLocation LAngleLoc,
                                       Decl **Params,
                                       unsigned NumParams,
                                       SourceLocation RAngleLoc);

  /// iterator - Iterates through the template parameters in this list.
  typedef Decl** iterator;

  /// const_iterator - Iterates through the template parameters in this list.
  typedef Decl* const* const_iterator;

  iterator begin() { return reinterpret_cast<Decl **>(this + 1); }
  const_iterator begin() const {
    return reinterpret_cast<Decl * const *>(this + 1);
  }
  iterator end() { return begin() + NumParams; }
  const_iterator end() const { return begin() + NumParams; }

  unsigned size() const { return NumParams; }

  Decl* getParam(unsigned Idx) {
    assert(Idx < size() && "Template parameter index out-of-range");
    return begin()[Idx];
  }

  const Decl* getParam(unsigned Idx) const {
    assert(Idx < size() && "Template parameter index out-of-range");
    return begin()[Idx];
  }

  /// \btief Returns the minimum number of arguments needed to form a
  /// template specialization. This may be fewer than the number of
  /// template parameters, if some of the parameters have default
  /// arguments or if there is a parameter pack.
  unsigned getMinRequiredArguments() const;

  SourceLocation getTemplateLoc() const { return TemplateLoc; }
  SourceLocation getLAngleLoc() const { return LAngleLoc; }
  SourceLocation getRAngleLoc() const { return RAngleLoc; }

  SourceRange getSourceRange() const {
    return SourceRange(TemplateLoc, RAngleLoc);
  }
};

/// \brief Represents a template argument within a class template
/// specialization.
class TemplateArgument {
  union {
    uintptr_t TypeOrValue;
    struct {
      char Value[sizeof(llvm::APSInt)];
      void *Type;
    } Integer;
    struct {
      TemplateArgument *Args;
      unsigned NumArgs;
      bool CopyArgs;
    } Args;
  };
  
  /// \brief Location of the beginning of this template argument.
  SourceLocation StartLoc;
  
public:
  /// \brief The type of template argument we're storing.
  enum ArgKind {
    Null = 0,
    /// The template argument is a type. Its value is stored in the
    /// TypeOrValue field.
    Type = 1,
    /// The template argument is a declaration
    Declaration = 2,
    /// The template argument is an integral value stored in an llvm::APSInt.
    Integral = 3,
    /// The template argument is a value- or type-dependent expression
    /// stored in an Expr*.
    Expression = 4,
    
    /// The template argument is actually a parameter pack. Arguments are stored
    /// in the Args struct.
    Pack =