path: root/lib/Sema/SemaTemplateInstantiateDecl.cpp

//===--- SemaTemplateInstantiateDecl.cpp - C++ Template Decl Instantiation ===/
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//===----------------------------------------------------------------------===/
//
//  This file implements C++ template instantiation for declarations.
//
//===----------------------------------------------------------------------===/
#include "Sema.h"
#include "clang/AST/ASTConsumer.h"
#include "clang/AST/ASTContext.h"
#include "clang/AST/DeclTemplate.h"
#include "clang/AST/DeclVisitor.h"
#include "clang/AST/Expr.h"
#include "llvm/Support/Compiler.h"

using namespace clang;

namespace {
  class VISIBILITY_HIDDEN TemplateDeclInstantiator 
    : public DeclVisitor<TemplateDeclInstantiator, Decl *> {
    Sema &SemaRef;
    DeclContext *Owner;
    const TemplateArgumentList &TemplateArgs;
    
  public:
    typedef Sema::OwningExprResult OwningExprResult;

    TemplateDeclInstantiator(Sema &SemaRef, DeclContext *Owner,
                             const TemplateArgumentList &TemplateArgs)
      : SemaRef(SemaRef), Owner(Owner), TemplateArgs(TemplateArgs) { }
    
    // FIXME: Once we get closer to completion, replace these manually-written
    // declarations with automatically-generated ones from
    // clang/AST/DeclNodes.def.
    Decl *VisitTranslationUnitDecl(TranslationUnitDecl *D);
    Decl *VisitNamespaceDecl(NamespaceDecl *D);
    Decl *VisitTypedefDecl(TypedefDecl *D);
    Decl *VisitVarDecl(VarDecl *D);
    Decl *VisitFieldDecl(FieldDecl *D);
    Decl *VisitStaticAssertDecl(StaticAssertDecl *D);
    Decl *VisitEnumDecl(EnumDecl *D);
    Decl *VisitEnumConstantDecl(EnumConstantDecl *D);
    Decl *VisitFunctionDecl(FunctionDecl *D);
    Decl *VisitCXXRecordDecl(CXXRecordDecl *D);
    Decl *VisitCXXMethodDecl(CXXMethodDecl *D);
    Decl *VisitCXXConstructorDecl(CXXConstructorDecl *D);
    Decl *VisitCXXDestructorDecl(CXXDestructorDecl *D);
    Decl *VisitCXXConversionDecl(CXXConversionDecl *D);
    ParmVarDecl *VisitParmVarDecl(ParmVarDecl *D);
    Decl *VisitOriginalParmVarDecl(OriginalParmVarDecl *D);

    // Base case. FIXME: Remove once we can instantiate everything.
    Decl *VisitDecl(Decl *) { 
      assert(false && "Template instantiation of unknown declaration kind!");
      return 0;
    }

    // Helper functions for instantiating methods.
    QualType InstantiateFunctionType(FunctionDecl *D,
                             llvm::SmallVectorImpl<ParmVarDecl *> &Params);
    bool InitFunctionInstantiation(FunctionDecl *New, FunctionDecl *Tmpl);
    bool InitMethodInstantiation(CXXMethodDecl *New, CXXMethodDecl *Tmpl);
  };
}

Decl *
TemplateDeclInstantiator::VisitTranslationUnitDecl(TranslationUnitDecl *D) {
  assert(false && "Translation units cannot be instantiated");
  return D;
}

Decl *
TemplateDeclInstantiator::VisitNamespaceDecl(NamespaceDecl *D) {
  assert(false && "Namespaces cannot be instantiated");
  return D;
}

Decl *TemplateDeclInstantiator::VisitTypedefDecl(TypedefDecl *D) {
  bool Invalid = false;
  QualType T = D->getUnderlyingType();
  if (T->isDependentType()) {
    T = SemaRef.InstantiateType(T, TemplateArgs, 
                                D->getLocation(), D->getDeclName());
    if (T.isNull()) {
      Invalid = true;
      T = SemaRef.Context.IntTy;
    }
  }
       
  // Create the new typedef
  TypedefDecl *Typedef
    = TypedefDecl::Create(SemaRef.Context, Owner, D->getLocation(),
                          D->getIdentifier(), T);
  if (Invalid)
    Typedef->setInvalidDecl();

  Owner->addDecl(Typedef);
    
  return Typedef;
}

Decl *TemplateDeclInstantiator::VisitVarDecl(VarDecl *D) {
  // Instantiate the type of the declaration
  QualType T = SemaRef.InstantiateType(D->getType(), TemplateArgs,
                                       D->getTypeSpecStartLoc(),
                                       D->getDeclName());
  if (T.isNull())
    return 0;

  // Build the instantiated declaration
  VarDecl *Var = VarDecl::Create(SemaRef.Context, Owner,
                                 D->getLocation(), D->getIdentifier(),
                                 T, D->getStorageClass