path: root/lib/Sema/SemaExceptionSpec.cpp

//===--- SemaExceptionSpec.cpp - C++ Exception Specifications ---*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file provides Sema routines for C++ exception specification testing.
//
//===----------------------------------------------------------------------===//

#include "clang/Sema/SemaInternal.h"
#include "clang/AST/CXXInheritance.h"
#include "clang/AST/Expr.h"
#include "clang/AST/ExprCXX.h"
#include "clang/AST/TypeLoc.h"
#include "clang/Lex/Preprocessor.h"
#include "clang/Basic/Diagnostic.h"
#include "clang/Basic/SourceManager.h"
#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/ADT/SmallString.h"

namespace clang {

static const FunctionProtoType *GetUnderlyingFunction(QualType T)
{
  if (const PointerType *PtrTy = T->getAs<PointerType>())
    T = PtrTy->getPointeeType();
  else if (const ReferenceType *RefTy = T->getAs<ReferenceType>())
    T = RefTy->getPointeeType();
  else if (const MemberPointerType *MPTy = T->getAs<MemberPointerType>())
    T = MPTy->getPointeeType();
  return T->getAs<FunctionProtoType>();
}

/// CheckSpecifiedExceptionType - Check if the given type is valid in an
/// exception specification. Incomplete types, or pointers to incomplete types
/// other than void are not allowed.
bool Sema::CheckSpecifiedExceptionType(QualType T, const SourceRange &Range) {

  // This check (and the similar one below) deals with issue 437, that changes
  // C++ 9.2p2 this way:
  // Within the class member-specification, the class is regarded as complete
  // within function bodies, default arguments, exception-specifications, and
  // constructor ctor-initializers (including such things in nested classes).
  if (T->isRecordType() && T->getAs<RecordType>()->isBeingDefined())
    return false;
    
  // C++ 15.4p2: A type denoted in an exception-specification shall not denote
  //   an incomplete type.
  if (RequireCompleteType(Range.getBegin(), T,
                          diag::err_incomplete_in_exception_spec,
                          /*direct*/0, Range))
    return true;

  // C++ 15.4p2: A type denoted in an exception-specification shall not denote
  //   an incomplete type a pointer or reference to an incomplete type, other
  //   than (cv) void*.
  int kind;
  if (const PointerType* IT = T->getAs<PointerType>()) {
    T = IT->getPointeeType();
    kind = 1;
  } else if (const ReferenceType* IT = T->getAs<ReferenceType>()) {
    T = IT->getPointeeType();
    kind = 2;
  } else
    return false;

  // Again as before
  if (T->isRecordType() && T->getAs<RecordType>()->isBeingDefined())
    return false;
    
  if (!T->isVoidType() &&
      RequireCompleteType(Range.getBegin(), T,
                          diag::err_incomplete_in_exception_spec, kind, Range))
    return true;

  return false;
}

/// CheckDistantExceptionSpec - Check if the given type is a pointer or pointer
/// to member to a function with an exception specification. This means that
/// it is invalid to add another level of indirection.
bool Sema::CheckDistantExceptionSpec(QualType T) {
  if (const PointerType *PT = T->getAs<PointerType>())
    T = PT->getPointeeType();
  else if (const MemberPointerType *PT = T->getAs<MemberPointerType>())
    T = PT->getPointeeType();
  else
    return false;

  const FunctionProtoType *FnT = T->getAs<FunctionProtoType>();
  if (!FnT)
    return false;

  return FnT->hasExceptionSpec();
}

const FunctionProtoType *
Sema::ResolveExceptionSpec(SourceLocation Loc, const FunctionProtoType *FPT) {
  // FIXME: If FD is a special member, we should delay computing its exception
  // specification until this point.
  if (FPT->getExceptionSpecType() != EST_Uninstantiated)
    return FPT;

  FunctionDecl *SourceDecl = FPT->getExceptionSpecDecl();
  const FunctionProtoType *SourceFPT =
      SourceDecl->getType()->castAs<FunctionProtoType>();

  if (SourceFPT->getExceptionSpecType() != EST_Uninstantiated)
    return SourceFPT;

  // Instantiate the exception specification now.
  InstantiateExceptionSpec(Loc, SourceDecl);

  return SourceDecl->getType()->castAs<FunctionProtoType>();