path: root/lib/Sema/SemaTemplateInstantiate.cpp

//===------- SemaTemplateInstantiate.cpp - C++ Template 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.
//
//===----------------------------------------------------------------------===/

#include "Sema.h"
#include "clang/AST/ASTContext.h"
#include "clang/AST/Expr.h"
#include "clang/AST/DeclTemplate.h"
#include "clang/Parse/DeclSpec.h"
#include "clang/Basic/LangOptions.h"
#include "llvm/Support/Compiler.h"

using namespace clang;

//===----------------------------------------------------------------------===/
// Template Instantiation Support
//===----------------------------------------------------------------------===/

/// \brief Retrieve the template argument list that should be used to
/// instantiate the given declaration.
const TemplateArgumentList &
Sema::getTemplateInstantiationArgs(NamedDecl *D) {
  if (ClassTemplateSpecializationDecl *Spec 
        = dyn_cast<ClassTemplateSpecializationDecl>(D))
    return Spec->getTemplateArgs();

  DeclContext *EnclosingTemplateCtx = D->getDeclContext();
  while (!isa<ClassTemplateSpecializationDecl>(EnclosingTemplateCtx)) {
    assert(!EnclosingTemplateCtx->isFileContext() &&
           "Tried to get the instantiation arguments of a non-template");
    EnclosingTemplateCtx = EnclosingTemplateCtx->getParent();
  }

  ClassTemplateSpecializationDecl *EnclosingTemplate 
    = cast<ClassTemplateSpecializationDecl>(EnclosingTemplateCtx);
  return EnclosingTemplate->getTemplateArgs();
}

Sema::InstantiatingTemplate::
InstantiatingTemplate(Sema &SemaRef, SourceLocation PointOfInstantiation,
                      Decl *Entity,
                      SourceRange InstantiationRange)
  :  SemaRef(SemaRef) {

  Invalid = CheckInstantiationDepth(PointOfInstantiation,
                                    InstantiationRange);
  if (!Invalid) {
    ActiveTemplateInstantiation Inst;
    Inst.Kind = ActiveTemplateInstantiation::TemplateInstantiation;
    Inst.PointOfInstantiation = PointOfInstantiation;
    Inst.Entity = reinterpret_cast<uintptr_t>(Entity);
    Inst.TemplateArgs = 0;
    Inst.NumTemplateArgs = 0;
    Inst.InstantiationRange = InstantiationRange;
    SemaRef.ActiveTemplateInstantiations.push_back(Inst);
    Invalid = false;
  }
}

Sema::InstantiatingTemplate::InstantiatingTemplate(Sema &SemaRef, 
                                         SourceLocation PointOfInstantiation,
                                         TemplateDecl *Template,
                                         const TemplateArgument *TemplateArgs,
                                         unsigned NumTemplateArgs,
                                         SourceRange InstantiationRange)
  : SemaRef(SemaRef) {

  Invalid = CheckInstantiationDepth(PointOfInstantiation,
                                    InstantiationRange);
  if (!Invalid) {
    ActiveTemplateInstantiation Inst;
    Inst.Kind 
      = ActiveTemplateInstantiation::DefaultTemplateArgumentInstantiation;
    Inst.PointOfInstantiation = PointOfInstantiation;
    Inst.Entity = reinterpret_cast<uintptr_t>(Template);
    Inst.TemplateArgs = TemplateArgs;
    Inst.NumTemplateArgs = NumTemplateArgs;
    Inst.InstantiationRange = InstantiationRange;
    SemaRef.ActiveTemplateInstantiations.push_back(Inst);
    Invalid = false;
  }
}

void Sema::InstantiatingTemplate::Clear() {
  if (!Invalid) {
    SemaRef.ActiveTemplateInstantiations.pop_back();
    Invalid = true;
  }
}

bool Sema::InstantiatingTemplate::CheckInstantiationDepth(
                                        SourceLocation PointOfInstantiation,
                                           SourceRange InstantiationRange) {
  if (SemaRef.ActiveTemplateInstantiations.size() 
       <= SemaRef.getLangOptions().InstantiationDepth)
    return false;

  SemaRef.Diag(PointOfInstantiation, 
               diag::err_template_recursion_depth_exceeded)
    << SemaRef.getLangOptions().InstantiationDepth
    << InstantiationRange;
  SemaRef.Diag(PointOfInstantiation, diag::note_template_recursion_depth)
    << SemaRef.getLangOptions().InstantiationDepth;
  return true;
}

/// \brief Prints the current instantiation stack through a series of
/// notes.
void Sema::PrintInstantiationStack() {
  for (llvm::SmallVector<ActiveTemplateInstantiation, 16>::reverse_iterator
         Active = ActiveTemplateInstantiations.rbegin(),
         ActiveEnd = ActiveTemplateInstantiations.rend();
       Active != ActiveEnd;
       ++Active) {
    switch (Active->Kind) {
    case ActiveTemplateInstantiation::TemplateInstantiation: {
      Decl *D = reinterpret_cast<Decl *>(Active->Entity);
      if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(D)) {
        unsigned DiagID = diag::note_template_member_class_here;
        if (isa<ClassTemplateSpecializationDecl>(Record))
          DiagID = diag::note_template_class_instantiation_here;
        Diags.Report(FullSourceLoc(Active->PointOfInstantiation, SourceMgr), 
                     DiagID)
          << Context.getTypeDeclType(Record)
          << Active->InstantiationRange;