C++ TemplateArgumentLoc::getSourceRange方法代码示例

bool ReduceClassTemplateParameter::reducePartialSpec(
       const ClassTemplatePartialSpecializationDecl *PartialD)
{
  const CXXRecordDecl *CXXRD = TheClassTemplateDecl->getTemplatedDecl();
  // it CXXRD has definition, skip it to avoid duplication
  if (CXXRD->hasDefinition())
    return false;

  if (!isValidForReduction(PartialD))
    return false;
  
  const ASTTemplateArgumentListInfo *ArgList = 
    PartialD->getTemplateArgsAsWritten();
  const TemplateArgumentLoc *ArgLocs = ArgList->getTemplateArgs();
  unsigned NumArgsAsWritten = ArgList->NumTemplateArgs;
  
  const TemplateArgumentLoc FirstArgLoc = ArgLocs[0];
  SourceRange FirstRange = FirstArgLoc.getSourceRange();
  SourceLocation StartLoc = FirstRange.getBegin();

  const TemplateArgumentLoc LastArgLoc = ArgLocs[NumArgsAsWritten - 1];
  SourceRange LastRange = LastArgLoc.getSourceRange();
  SourceLocation EndLoc = 
    RewriteHelper->getEndLocationUntil(LastRange, '>');

  RewriteHelper->removeTextFromLeftAt(SourceRange(StartLoc, EndLoc), '<', EndLoc);
  return true;
}

void ClassTemplateToClass::rewriteClassTemplatePartialSpecs(void)
{
  SmallVector<ClassTemplatePartialSpecializationDecl *, 10> PartialDecls;
  TheClassTemplateDecl->getPartialSpecializations(PartialDecls);

  for (SmallVector<ClassTemplatePartialSpecializationDecl *, 10>::iterator 
         I = PartialDecls.begin(), E = PartialDecls.end(); I != E; ++I) {
    const ClassTemplatePartialSpecializationDecl *PartialD = (*I);
    removeTemplateAndParameter(PartialD->getSourceRange().getBegin(), 
                               PartialD->getTemplateParameters());

    TemplateArgumentLoc *ArgLocs = PartialD->getTemplateArgsAsWritten();
    TransAssert(ArgLocs && "Invalid ArgLocs!");
    TemplateArgumentLoc FirstArgLoc = ArgLocs[0];
    SourceLocation StartLoc = FirstArgLoc.getSourceRange().getBegin();

    unsigned NumArgs = PartialD->getNumTemplateArgsAsWritten();
    TransAssert((NumArgs > 0) && "Invalid NumArgs!");
    TemplateArgumentLoc LastArgLoc = ArgLocs[NumArgs - 1];
    SourceRange LastRange = LastArgLoc.getSourceRange();
    SourceLocation EndLoc = RewriteHelper->getEndLocationUntil(LastRange, '>');
    
    RewriteHelper->removeTextFromLeftAt(SourceRange(StartLoc, EndLoc),
                                        '<', EndLoc);
  }
}

// ISSUE: The transformation is known to go wrong in the following case:
// template<typename T1, typename T2> struct S;
// template<typename T1, typename T2> struct S<T2, T1>;
void ReduceClassTemplateParameter::removeParameterFromPartialSpecs()
{
  SmallVector<ClassTemplatePartialSpecializationDecl *, 10> PartialDecls;
  TheClassTemplateDecl->getPartialSpecializations(PartialDecls);

  for (SmallVector<ClassTemplatePartialSpecializationDecl *, 10>::iterator 
         I = PartialDecls.begin(), E = PartialDecls.end(); I != E; ++I) {
    const ClassTemplatePartialSpecializationDecl *PartialD = (*I);
    
    const ASTTemplateArgumentListInfo *ArgList = 
      PartialD->getTemplateArgsAsWritten();
    const TemplateArgumentLoc *ArgLocs = ArgList->getTemplateArgs();
    unsigned NumArgs = ArgList->NumTemplateArgs;
    
    if (!ArgLocs)
      continue;

    // handle a special case where we could reduce a partial specialization
    // to a class template definition, e.g.:
    //   template<typename T1, typename T2> struct A;
    //   template<typename T1> struct A<T1, int> { };
    // ==>
    //   template<typename T1> struct A;
    //   template<typename T1> struct A { };
    if (reducePartialSpec(PartialD))
      continue;

    if ((TheParameterIndex >= NumArgs) && hasDefaultArg)
      return;

    TransAssert((TheParameterIndex < NumArgs) && 
                 "Bad NumArgs from partial template decl!");
    TemplateArgumentLoc ArgLoc = ArgLocs[TheParameterIndex];

    TemplateArgument Arg = ArgLoc.getArgument();
    removeOneParameterFromPartialDecl(PartialD, Arg);
     
    SourceRange Range = ArgLoc.getSourceRange();

    if (NumArgs == 1) {
      SourceLocation StartLoc = Range.getBegin();
      SourceLocation EndLoc = 
        RewriteHelper->getEndLocationUntil(Range, '>');
      EndLoc = EndLoc.getLocWithOffset(-1);
      TheRewriter.RemoveText(SourceRange(StartLoc, EndLoc));
    }
    else if ((TheParameterIndex + 1) == NumArgs) {
      // Seems there is no getRAngleLoc() utility for 
      // template arguments from a partial specialization
      SourceLocation EndLoc = 
        RewriteHelper->getEndLocationUntil(Range, '>');
      EndLoc = EndLoc.getLocWithOffset(-1);
      RewriteHelper->removeTextFromLeftAt(Range, ',', EndLoc);
    }
    else {
      RewriteHelper->removeTextUntil(Range, ',');
    }
  }
}

bool ReduceClassTemplateParameterRewriteVisitor::
       VisitTemplateSpecializationTypeLoc(TemplateSpecializationTypeLoc Loc)
{
  // Invalidation can be introduced by constructor's initialization list, e.g.:
  // template<typename T1, typename T2> class A { };
  // class B : public A<int, int> {
  //   int m;
  //   B(int x) : m(x) {}
  // };
  // In RecursiveASTVisitor.h, TraverseConstructorInitializer will visit the part
  // of initializing base class's, i.e. through base's default constructor 
  if (Loc.getBeginLoc().isInvalid())
    return true;
  const TemplateSpecializationType *Ty = 
    dyn_cast<TemplateSpecializationType>(Loc.getTypePtr());
  TransAssert(Ty && "Invalid TemplateSpecializationType!");

  TemplateName TmplName = Ty->getTemplateName();
  if (!ConsumerInstance->referToTheTemplateDecl(TmplName))
    return true;

  unsigned NumArgs = Loc.getNumArgs();
  // I would put a stronger assert here, i.e., 
  // " (ConsumerInstance->TheParameterIndex >= NumArgs) && 
  // ConsumerInstance->hasDefaultArg "
  // but sometimes ill-formed input could yield incomplete
  // info, e.g., for two template decls which refer to the same
  // template def, one decl could have a non-null default arg,
  // while another decl's default arg field could be null. 
  if (ConsumerInstance->TheParameterIndex >= NumArgs)
    return true;

  TransAssert((ConsumerInstance->TheParameterIndex < NumArgs) &&
              "TheParameterIndex cannot be greater than NumArgs!");
  TemplateArgumentLoc ArgLoc = Loc.getArgLoc(ConsumerInstance->TheParameterIndex);
  SourceRange Range = ArgLoc.getSourceRange();

  if (NumArgs == 1) {
    ConsumerInstance->TheRewriter.ReplaceText(SourceRange(Loc.getLAngleLoc(),
                                                          Loc.getRAngleLoc()),
                                              "<>");
  }
  else if ((ConsumerInstance->TheParameterIndex + 1) == NumArgs) {
    SourceLocation EndLoc = Loc.getRAngleLoc();
    EndLoc = EndLoc.getLocWithOffset(-1);
    ConsumerInstance->RewriteHelper->removeTextFromLeftAt(
                                       Range, ',', EndLoc);
  }
  else {
    ConsumerInstance->RewriteHelper->removeTextUntil(Range, ',');
  }
  return true;
}

void ASTDumper::dumpTemplateArgumentLoc(const TemplateArgumentLoc &A) {
  dumpTemplateArgument(A.getArgument(), A.getSourceRange());
}