path: root/lib/AST/DeclTemplate.cpp

//===--- DeclTemplate.cpp - Template Declaration AST Node Implementation --===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements the C++ related Decl classes for templates.
//
//===----------------------------------------------------------------------===//

#include "clang/AST/DeclTemplate.h"
#include "clang/AST/ASTContext.h"
#include "clang/AST/ASTMutationListener.h"
#include "clang/AST/DeclCXX.h"
#include "clang/AST/Expr.h"
#include "clang/AST/ExprCXX.h"
#include "clang/AST/TypeLoc.h"
#include "clang/Basic/IdentifierTable.h"
#include "llvm/ADT/STLExtras.h"
#include <memory>
using namespace clang;

//===----------------------------------------------------------------------===//
// TemplateParameterList Implementation
//===----------------------------------------------------------------------===//

TemplateParameterList::TemplateParameterList(SourceLocation TemplateLoc,
                                             SourceLocation LAngleLoc,
                                             NamedDecl **Params, unsigned NumParams,
                                             SourceLocation RAngleLoc)
  : TemplateLoc(TemplateLoc), LAngleLoc(LAngleLoc), RAngleLoc(RAngleLoc),
    NumParams(NumParams), ContainsUnexpandedParameterPack(false) {
  assert(this->NumParams == NumParams && "Too many template parameters");
  for (unsigned Idx = 0; Idx < NumParams; ++Idx) {
    NamedDecl *P = Params[Idx];
    begin()[Idx] = P;

    if (!P->isTemplateParameterPack()) {
      if (NonTypeTemplateParmDecl *NTTP = dyn_cast<NonTypeTemplateParmDecl>(P))
        if (NTTP->getType()->containsUnexpandedParameterPack())
          ContainsUnexpandedParameterPack = true;

      if (TemplateTemplateParmDecl *TTP = dyn_cast<TemplateTemplateParmDecl>(P))
        if (TTP->getTemplateParameters()->containsUnexpandedParameterPack())
          ContainsUnexpandedParameterPack = true;

      // FIXME: If a default argument contains an unexpanded parameter pack, the
      // template parameter list does too.
    }
  }
}

TemplateParameterList *
TemplateParameterList::Create(const ASTContext &C, SourceLocation TemplateLoc,
                              SourceLocation LAngleLoc, NamedDecl **Params,
                              unsigned NumParams, SourceLocation RAngleLoc) {
  unsigned Size = sizeof(TemplateParameterList) 
                + sizeof(NamedDecl *) * NumParams;
  unsigned Align = std::max(llvm::alignOf<TemplateParameterList>(),
                            llvm::alignOf<NamedDecl*>());
  void *Mem = C.Allocate(Size, Align);
  return new (Mem) TemplateParameterList(TemplateLoc, LAngleLoc, Params,
                                         NumParams, RAngleLoc);
}

unsigned TemplateParameterList::getMinRequiredArguments() const {
  unsigned NumRequiredArgs = 0;
  for (iterator P = const_cast<TemplateParameterList *>(this)->begin(), 
             PEnd = const_cast<TemplateParameterList *>(this)->end(); 
       P != PEnd; ++P) {
    if ((*P)->isTemplateParameterPack()) {
      if (NonTypeTemplateParmDecl *NTTP = dyn_cast<NonTypeTemplateParmDecl>(*P))
        if (NTTP->isExpandedParameterPack()) {
          NumRequiredArgs += NTTP->getNumExpansionTypes();
          continue;
        }
      
      break;
    }
  
    if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(*P)) {
      if (TTP->hasDefaultArgument())
        break;
    } else if (NonTypeTemplateParmDecl *NTTP 
                                    = dyn_cast<NonTypeTemplateParmDecl>(*P)) {
      if (NTTP->hasDefaultArgument())
        break;
    } else if (cast<TemplateTemplateParmDecl>(*P)->hasDefaultArgument())
      break;
    
    ++NumRequiredArgs;
  }
  
  return NumRequiredArgs;
}

unsigned TemplateParameterList::getDepth() const {
  if (size() == 0)
    return 0;
  
  const NamedDecl *FirstParm = getParam(0);
  if (const TemplateTypeParmDecl *TTP
        = dyn_cast<TemplateTypeParmDecl>(FirstParm))
    return TTP->getDepth();
  else if (const NonTypeTemplateParmDecl *NTTP 
             = dyn_cast<NonTypeTemplateParmDecl>(FirstParm))
    return NTTP->getDepth();
  else
    return cast<TemplateTemplateParmDecl>(FirstParm)->getDepth();
}

static void AdoptTemplateParameterList(TemplateParameterList *Params,
                                       DeclContext *Owner) {
  for (TemplateParameterList::iterator P = Params->begin(), 
                                    PEnd = Params->end();
       P != PEnd; ++P) {
    (*P)->setDeclContext(Owner);
    
    if (TemplateTemplateParmDecl *TTP = dyn_cast<TemplateTemplateParmDecl>(*P))
      AdoptTemplateParameterList(TTP->getTemplateParameters(), Owner);
  }
}

//===----------------------------------------------------------------------===//
// RedeclarableTemplateDecl Implementation
//===----------------------------------------------------------------------===//