C++ QualType::isMemberPointerType方法代码示例

void MicrosoftCXXNameMangler::mangleType(QualType T) {
  // Only operate on the canonical type!
  T = getASTContext().getCanonicalType(T);
  
  Qualifiers Quals = T.getLocalQualifiers();
  if (Quals) {
    // We have to mangle these now, while we still have enough information.
    // <pointer-cvr-qualifiers> ::= P  # pointer
    //                          ::= Q  # const pointer
    //                          ::= R  # volatile pointer
    //                          ::= S  # const volatile pointer
    if (T->isAnyPointerType() || T->isMemberPointerType() ||
        T->isBlockPointerType()) {
      if (!Quals.hasVolatile())
        Out << 'Q';
      else {
        if (!Quals.hasConst())
          Out << 'R';
        else
          Out << 'S';
      }
    } else
      // Just emit qualifiers like normal.
      // NB: When we mangle a pointer/reference type, and the pointee
      // type has no qualifiers, the lack of qualifier gets mangled
      // in there.
      mangleQualifiers(Quals, false);
  } else if (T->isAnyPointerType() || T->isMemberPointerType() ||
             T->isBlockPointerType()) {
    Out << 'P';
  }
  switch (T->getTypeClass()) {
#define ABSTRACT_TYPE(CLASS, PARENT)
#define NON_CANONICAL_TYPE(CLASS, PARENT) \
case Type::CLASS: \
llvm_unreachable("can't mangle non-canonical type " #CLASS "Type"); \
return;
#define TYPE(CLASS, PARENT) \
case Type::CLASS: \
mangleType(static_cast<const CLASS##Type*>(T.getTypePtr())); \
break;
#include "clang/AST/TypeNodes.def"
  }
}

/// CastsAwayConstness - Check if the pointer conversion from SrcType to
/// DestType casts away constness as defined in C++ 5.2.11p8ff. This is used by
/// the cast checkers.  Both arguments must denote pointer (possibly to member)
/// types.
bool
CastsAwayConstness(Sema &Self, QualType SrcType, QualType DestType)
{
  // Casting away constness is defined in C++ 5.2.11p8 with reference to
  // C++ 4.4. We piggyback on Sema::IsQualificationConversion for this, since
  // the rules are non-trivial. So first we construct Tcv *...cv* as described
  // in C++ 5.2.11p8.
  assert((SrcType->isPointerType() || SrcType->isMemberPointerType()) &&
         "Source type is not pointer or pointer to member.");
  assert((DestType->isPointerType() || DestType->isMemberPointerType()) &&
         "Destination type is not pointer or pointer to member.");

  QualType UnwrappedSrcType = SrcType, UnwrappedDestType = DestType;
  llvm::SmallVector<unsigned, 8> cv1, cv2;

  // Find the qualifications.
  while (Self.UnwrapSimilarPointerTypes(UnwrappedSrcType, UnwrappedDestType)) {
    cv1.push_back(UnwrappedSrcType.getCVRQualifiers());
    cv2.push_back(UnwrappedDestType.getCVRQualifiers());
  }
  assert(cv1.size() > 0 && "Must have at least one pointer level.");

  // Construct void pointers with those qualifiers (in reverse order of
  // unwrapping, of course).
  QualType SrcConstruct = Self.Context.VoidTy;
  QualType DestConstruct = Self.Context.VoidTy;
  for (llvm::SmallVector<unsigned, 8>::reverse_iterator i1 = cv1.rbegin(),
                                                        i2 = cv2.rbegin();
       i1 != cv1.rend(); ++i1, ++i2)
  {
    SrcConstruct = Self.Context.getPointerType(
      SrcConstruct.getQualifiedType(*i1));
    DestConstruct = Self.Context.getPointerType(
      DestConstruct.getQualifiedType(*i2));
  }

  // Test if they're compatible.
  return SrcConstruct != DestConstruct &&
    !Self.IsQualificationConversion(SrcConstruct, DestConstruct);
}

// FIXME: should rewrite according to the cast kind.
SVal SValBuilder::evalCast(SVal val, QualType castTy, QualType originalTy) {
  castTy = Context.getCanonicalType(castTy);
  originalTy = Context.getCanonicalType(originalTy);
  if (val.isUnknownOrUndef() || castTy == originalTy)
    return val;

  if (castTy->isBooleanType()) {
    if (val.isUnknownOrUndef())
      return val;
    if (val.isConstant())
      return makeTruthVal(!val.isZeroConstant(), castTy);
    if (!Loc::isLocType(originalTy) &&
        !originalTy->isIntegralOrEnumerationType() &&
        !originalTy->isMemberPointerType())
      return UnknownVal();
    if (SymbolRef Sym = val.getAsSymbol(true)) {
      BasicValueFactory &BVF = getBasicValueFactory();
      // FIXME: If we had a state here, we could see if the symbol is known to
      // be zero, but we don't.
      return makeNonLoc(Sym, BO_NE, BVF.getValue(0, Sym->getType()), castTy);
    }
    // Loc values are not always true, they could be weakly linked functions.
    if (Optional<Loc> L = val.getAs<Loc>())
      return evalCastFromLoc(*L, castTy);

    Loc L = val.castAs<nonloc::LocAsInteger>().getLoc();
    return evalCastFromLoc(L, castTy);
  }

  // For const casts, casts to void, just propagate the value.
  if (!castTy->isVariableArrayType() && !originalTy->isVariableArrayType())
    if (shouldBeModeledWithNoOp(Context, Context.getPointerType(castTy),
                                         Context.getPointerType(originalTy)))
      return val;
  
  // Check for casts from pointers to integers.
  if (castTy->isIntegralOrEnumerationType() && Loc::isLocType(originalTy))
    return evalCastFromLoc(val.castAs<Loc>(), castTy);

  // Check for casts from integers to pointers.
  if (Loc::isLocType(castTy) && originalTy->isIntegralOrEnumerationType()) {
    if (Optional<nonloc::LocAsInteger> LV = val.getAs<nonloc::LocAsInteger>()) {
      if (const MemRegion *R = LV->getLoc().getAsRegion()) {
        StoreManager &storeMgr = StateMgr.getStoreManager();
        R = storeMgr.castRegion(R, castTy);
        return R ? SVal(loc::MemRegionVal(R)) : UnknownVal();
      }
      return LV->getLoc();
    }
    return dispatchCast(val, castTy);
  }

  // Just pass through function and block pointers.
  if (originalTy->isBlockPointerType() || originalTy->isFunctionPointerType()) {
    assert(Loc::isLocType(castTy));
    return val;
  }

  // Check for casts from array type to another type.
  if (const ArrayType *arrayT =
                      dyn_cast<ArrayType>(originalTy.getCanonicalType())) {
    // We will always decay to a pointer.
    QualType elemTy = arrayT->getElementType();
    val = StateMgr.ArrayToPointer(val.castAs<Loc>(), elemTy);

    // Are we casting from an array to a pointer?  If so just pass on
    // the decayed value.
    if (castTy->isPointerType() || castTy->isReferenceType())
      return val;

    // Are we casting from an array to an integer?  If so, cast the decayed
    // pointer value to an integer.
    assert(castTy->isIntegralOrEnumerationType());

    // FIXME: Keep these here for now in case we decide soon that we
    // need the original decayed type.
    //    QualType elemTy = cast<ArrayType>(originalTy)->getElementType();
    //    QualType pointerTy = C.getPointerType(elemTy);
    return evalCastFromLoc(val.castAs<Loc>(), castTy);
  }

  // Check for casts from a region to a specific type.
  if (const MemRegion *R = val.getAsRegion()) {
    // Handle other casts of locations to integers.
    if (castTy->isIntegralOrEnumerationType())
      return evalCastFromLoc(loc::MemRegionVal(R), castTy);

    // FIXME: We should handle the case where we strip off view layers to get
    //  to a desugared type.
    if (!Loc::isLocType(castTy)) {
      // FIXME: There can be gross cases where one casts the result of a function
      // (that returns a pointer) to some other value that happens to fit
      // within that pointer value.  We currently have no good way to
      // model such operations.  When this happens, the underlying operation
      // is that the caller is reasoning about bits.  Conceptually we are
      // layering a "view" of a location on top of those bits.  Perhaps
      // we need to be more lazy about mutual possible views, even on an
      // SVal?  This may be necessary for bit-level reasoning as well.
      return UnknownVal();
//.........这里部分代码省略.........

/// CheckConstCast - Check that a const_cast\<DestType\>(SrcExpr) is valid.
/// Refer to C++ 5.2.11 for details. const_cast is typically used in code
/// like this:
/// const char *str = "literal";
/// legacy_function(const_cast\<char*\>(str));
void
CheckConstCast(Sema &Self, Expr *&SrcExpr, QualType DestType,
               const SourceRange &OpRange, const SourceRange &DestRange)
{
  QualType OrigDestType = DestType, OrigSrcType = SrcExpr->getType();

  DestType = Self.Context.getCanonicalType(DestType);
  QualType SrcType = SrcExpr->getType();
  if (const LValueReferenceType *DestTypeTmp =
        DestType->getAsLValueReferenceType()) {
    if (SrcExpr->isLvalue(Self.Context) != Expr::LV_Valid) {
      // Cannot cast non-lvalue to lvalue reference type.
      Self.Diag(OpRange.getBegin(), diag::err_bad_cxx_cast_rvalue)
        << "const_cast" << OrigDestType << SrcExpr->getSourceRange();
      return;
    }

    // C++ 5.2.11p4: An lvalue of type T1 can be [cast] to an lvalue of type T2
    //   [...] if a pointer to T1 can be [cast] to the type pointer to T2.
    DestType = Self.Context.getPointerType(DestTypeTmp->getPointeeType());
    SrcType = Self.Context.getPointerType(SrcType);
  } else {
    // C++ 5.2.11p1: Otherwise, the result is an rvalue and the
    //   lvalue-to-rvalue, array-to-pointer, and function-to-pointer standard
    //   conversions are performed on the expression.
    Self.DefaultFunctionArrayConversion(SrcExpr);
    SrcType = SrcExpr->getType();
  }

  // C++ 5.2.11p5: For a const_cast involving pointers to data members [...]
  //   the rules for const_cast are the same as those used for pointers.

  if (!DestType->isPointerType() && !DestType->isMemberPointerType()) {
    // Cannot cast to non-pointer, non-reference type. Note that, if DestType
    // was a reference type, we converted it to a pointer above.
    // The status of rvalue references isn't entirely clear, but it looks like
    // conversion to them is simply invalid.
    // C++ 5.2.11p3: For two pointer types [...]
    Self.Diag(OpRange.getBegin(), diag::err_bad_const_cast_dest)
      << OrigDestType << DestRange;
    return;
  }
  if (DestType->isFunctionPointerType() ||
      DestType->isMemberFunctionPointerType()) {
    // Cannot cast direct function pointers.
    // C++ 5.2.11p2: [...] where T is any object type or the void type [...]
    // T is the ultimate pointee of source and target type.
    Self.Diag(OpRange.getBegin(), diag::err_bad_const_cast_dest)
      << OrigDestType << DestRange;
    return;
  }
  SrcType = Self.Context.getCanonicalType(SrcType);

  // Unwrap the pointers. Ignore qualifiers. Terminate early if the types are
  // completely equal.
  // FIXME: const_cast should probably not be able to convert between pointers
  // to different address spaces.
  // C++ 5.2.11p3 describes the core semantics of const_cast. All cv specifiers
  // in multi-level pointers may change, but the level count must be the same,
  // as must be the final pointee type.
  while (SrcType != DestType &&
         Self.UnwrapSimilarPointerTypes(SrcType, DestType)) {
    SrcType = SrcType.getUnqualifiedType();
    DestType = DestType.getUnqualifiedType();
  }

  // Doug Gregor said to disallow this until users complain.
#if 0
  // If we end up with constant arrays of equal size, unwrap those too. A cast
  // from const int [N] to int (&)[N] is invalid by my reading of the
  // standard, but g++ accepts it even with -ansi -pedantic.
  // No more than one level, though, so don't embed this in the unwrap loop
  // above.
  const ConstantArrayType *SrcTypeArr, *DestTypeArr;
  if ((SrcTypeArr = Self.Context.getAsConstantArrayType(SrcType)) &&
     (DestTypeArr = Self.Context.getAsConstantArrayType(DestType)))
  {
    if (SrcTypeArr->getSize() != DestTypeArr->getSize()) {
      // Different array sizes.
      Self.Diag(OpRange.getBegin(), diag::err_bad_cxx_cast_generic)
        << "const_cast" << OrigDestType << OrigSrcType << OpRange;
      return;
    }
    SrcType = SrcTypeArr->getElementType().getUnqualifiedType();
    DestType = DestTypeArr->getElementType().getUnqualifiedType();
  }
#endif

  // Since we're dealing in canonical types, the remainder must be the same.
  if (SrcType != DestType) {
    // Cast between unrelated types.
    Self.Diag(OpRange.getBegin(), diag::err_bad_cxx_cast_generic)
      << "const_cast" << OrigDestType << OrigSrcType << OpRange;
    return;
  }
//.........这里部分代码省略.........

/// TryConstCast - See if a const_cast from source to destination is allowed,
/// and perform it if it is.
static TryCastResult TryConstCast(Sema &Self, Expr *SrcExpr, QualType DestType,
                                  bool CStyle, unsigned &msg) {
  DestType = Self.Context.getCanonicalType(DestType);
  QualType SrcType = SrcExpr->getType();
  if (const LValueReferenceType *DestTypeTmp =
        DestType->getAs<LValueReferenceType>()) {
    if (SrcExpr->isLvalue(Self.Context) != Expr::LV_Valid) {
      // Cannot const_cast non-lvalue to lvalue reference type. But if this
      // is C-style, static_cast might find a way, so we simply suggest a
      // message and tell the parent to keep searching.
      msg = diag::err_bad_cxx_cast_rvalue;
      return TC_NotApplicable;
    }

    // C++ 5.2.11p4: An lvalue of type T1 can be [cast] to an lvalue of type T2
    //   [...] if a pointer to T1 can be [cast] to the type pointer to T2.
    DestType = Self.Context.getPointerType(DestTypeTmp->getPointeeType());
    SrcType = Self.Context.getPointerType(SrcType);
  }

  // C++ 5.2.11p5: For a const_cast involving pointers to data members [...]
  //   the rules for const_cast are the same as those used for pointers.

  if (!DestType->isPointerType() && !DestType->isMemberPointerType()) {
    // Cannot cast to non-pointer, non-reference type. Note that, if DestType
    // was a reference type, we converted it to a pointer above.
    // The status of rvalue references isn't entirely clear, but it looks like
    // conversion to them is simply invalid.
    // C++ 5.2.11p3: For two pointer types [...]
    if (!CStyle)
      msg = diag::err_bad_const_cast_dest;
    return TC_NotApplicable;
  }
  if (DestType->isFunctionPointerType() ||
      DestType->isMemberFunctionPointerType()) {
    // Cannot cast direct function pointers.
    // C++ 5.2.11p2: [...] where T is any object type or the void type [...]
    // T is the ultimate pointee of source and target type.
    if (!CStyle)
      msg = diag::err_bad_const_cast_dest;
    return TC_NotApplicable;
  }
  SrcType = Self.Context.getCanonicalType(SrcType);

  // Unwrap the pointers. Ignore qualifiers. Terminate early if the types are
  // completely equal.
  // FIXME: const_cast should probably not be able to convert between pointers
  // to different address spaces.
  // C++ 5.2.11p3 describes the core semantics of const_cast. All cv specifiers
  // in multi-level pointers may change, but the level count must be the same,
  // as must be the final pointee type.
  while (SrcType != DestType &&
         Self.UnwrapSimilarPointerTypes(SrcType, DestType)) {
    SrcType = SrcType.getUnqualifiedType();
    DestType = DestType.getUnqualifiedType();
  }

  // Since we're dealing in canonical types, the remainder must be the same.
  if (SrcType != DestType)
    return TC_NotApplicable;

  return TC_Success;
}

  Expr* ValueExtractionSynthesizer::SynthesizeSVRInit(Expr* E) {
    if (!m_gClingVD)
      FindAndCacheRuntimeDecls();

    // Build a reference to gCling
    ExprResult gClingDRE
      = m_Sema->BuildDeclRefExpr(m_gClingVD, m_Context->VoidPtrTy,
                                 VK_RValue, SourceLocation());
    // We have the wrapper as Sema's CurContext
    FunctionDecl* FD = cast<FunctionDecl>(m_Sema->CurContext);

    ExprWithCleanups* Cleanups = 0;
    // In case of ExprWithCleanups we need to extend its 'scope' to the call.
    if (E && isa<ExprWithCleanups>(E)) {
      Cleanups = cast<ExprWithCleanups>(E);
      E = Cleanups->getSubExpr();
    }

    // Build a reference to Value* in the wrapper, should be
    // the only argument of the wrapper.
    SourceLocation locStart = (E) ? E->getLocStart() : FD->getLocStart();
    SourceLocation locEnd = (E) ? E->getLocEnd() : FD->getLocEnd();
    ExprResult wrapperSVRDRE
      = m_Sema->BuildDeclRefExpr(FD->getParamDecl(0), m_Context->VoidPtrTy,
                                 VK_RValue, locStart);
    QualType ETy = (E) ? E->getType() : m_Context->VoidTy;
    QualType desugaredTy = ETy.getDesugaredType(*m_Context);

    // The expr result is transported as reference, pointer, array, float etc
    // based on the desugared type. We should still expose the typedef'ed
    // (sugared) type to the cling::Value.
    if (desugaredTy->isRecordType() && E->getValueKind() == VK_LValue) {
      // returning a lvalue (not a temporary): the value should contain
      // a reference to the lvalue instead of copying it.
      desugaredTy = m_Context->getLValueReferenceType(desugaredTy);
      ETy = m_Context->getLValueReferenceType(ETy);
    }
    Expr* ETyVP
      = utils::Synthesize::CStyleCastPtrExpr(m_Sema, m_Context->VoidPtrTy,
                                             (uintptr_t)ETy.getAsOpaquePtr());

    // Pass whether to Value::dump() or not:
    Expr* EVPOn
      = new (*m_Context) CharacterLiteral(getCompilationOpts().ValuePrinting,
                                          CharacterLiteral::Ascii,
                                          m_Context->CharTy,
                                          SourceLocation());

    llvm::SmallVector<Expr*, 6> CallArgs;
    CallArgs.push_back(gClingDRE.get());
    CallArgs.push_back(wrapperSVRDRE.get());
    CallArgs.push_back(ETyVP);
    CallArgs.push_back(EVPOn);

    ExprResult Call;
    SourceLocation noLoc = locStart;
    if (desugaredTy->isVoidType()) {
      // In cases where the cling::Value gets reused we need to reset the
      // previous settings to void.
      // We need to synthesize setValueNoAlloc(...), E, because we still need
      // to run E.

      // FIXME: Suboptimal: this discards the already created AST nodes.
      QualType vpQT = m_Context->VoidPtrTy;
      QualType vQT = m_Context->VoidTy;
      Expr* vpQTVP
        = utils::Synthesize::CStyleCastPtrExpr(m_Sema, vpQT,
                                               (uintptr_t)vQT.getAsOpaquePtr());
      CallArgs[2] = vpQTVP;


      Call = m_Sema->ActOnCallExpr(/*Scope*/0, m_UnresolvedNoAlloc,
                                   locStart, CallArgs, locEnd);

      if (E)
        Call = m_Sema->CreateBuiltinBinOp(locStart, BO_Comma, Call.get(), E);

    }
    else if (desugaredTy->isRecordType() || desugaredTy->isConstantArrayType()
             || desugaredTy->isMemberPointerType()) {
      // 2) object types :
      // check existence of copy constructor before call
      if (!desugaredTy->isMemberPointerType()
          && !availableCopyConstructor(desugaredTy, m_Sema))
        return E;
      // call new (setValueWithAlloc(gCling, &SVR, ETy)) (E)
      Call = m_Sema->ActOnCallExpr(/*Scope*/0, m_UnresolvedWithAlloc,
                                   locStart, CallArgs, locEnd);
      Expr* placement = Call.get();
      if (const ConstantArrayType* constArray
          = dyn_cast<ConstantArrayType>(desugaredTy.getTypePtr())) {
        CallArgs.clear();
        CallArgs.push_back(E);
        CallArgs.push_back(placement);
        size_t arrSize
          = m_Context->getConstantArrayElementCount(constArray);
        Expr* arrSizeExpr
          = utils::Synthesize::IntegerLiteralExpr(*m_Context, arrSize);

        CallArgs.push_back(arrSizeExpr);
//.........这里部分代码省略.........