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/Basic/Diagnostic.h"
#include "clang/Basic/SourceManager.h"
#include "clang/Lex/Preprocessor.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.
///
/// \param[in,out] T  The exception type. This will be decayed to a pointer type
///                   when the input is an array or a function type.
bool Sema::CheckSpecifiedExceptionType(QualType &T, const SourceRange &Range) {
  // C++11 [except.spec]p2:
  //   A type cv T, "array of T", or "function returning T" denoted
  //   in an exception-specification is adjusted to type T, "pointer to T", or
  //   "pointer to function returning T", respectively.
  //
  // We also apply this rule in C++98.
  if (T->isArrayType())
    T = Context.getArrayDecayedType(T);
  else if (T->isFunctionType())
    T = Context.getPointerType(T);

  int Kind = 0;
  QualType PointeeT = T;
  if (const PointerType *PT = T->getAs<PointerType>()) {
    PointeeT = PT->getPointeeType();
    Kind = 1;

    // cv void* is explicitly permitted, despite being a pointer to an
    // incomplete type.
    if (PointeeT->isVoidType())
      return false;
  } else if (const ReferenceType *RT = T->getAs<ReferenceType>()) {
    PointeeT = RT->getPointeeType();
    Kind = 2;

    if (RT->isRValueReferenceType()) {
      // C++11 [except.spec]p2:
      //   A type denoted in an exception-specification shall not denote [...]
      //   an rvalue reference type.
      Diag(Range.getBegin(), diag::err_rref_in_exception_spec)
        << T << Range;
      return true;
    }
  }

  // C++11 [except.spec]p2:
  //   A type denoted in an exception-specification shall not denote an
  //   incomplete type other than a class currently being defined [...].
  //   A type denoted in an exception-specification shall not denote a
  //   pointer or reference to an incomplete type, other than (cv) void* or a
  //   pointer or reference to a class currently being defined.
  if (!(PointeeT->isRecordType() &&
        PointeeT->getAs<RecordType>()->isBeingDefined()) &&
      RequireCompleteType(Range.getBegin(), PointeeT,
                          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 *