/// \brief \arg Loc is the end of a statement range. This returns the location
/// of the semicolon following the statement.
/// If no semicolon is found or the location is inside a macro, the returned
/// source location will be invalid.
SourceLocation trans::findSemiAfterLocation(SourceLocation loc,
ASTContext &Ctx) {
SourceManager &SM = Ctx.getSourceManager();
if (loc.isMacroID()) {
if (!Lexer::isAtEndOfMacroExpansion(loc, SM, Ctx.getLangOptions()))
return SourceLocation();
loc = SM.getExpansionRange(loc).second;
}
loc = Lexer::getLocForEndOfToken(loc, /*Offset=*/0, SM, Ctx.getLangOptions());
// Break down the source location.
std::pair<FileID, unsigned> locInfo = SM.getDecomposedLoc(loc);
// Try to load the file buffer.
bool invalidTemp = false;
StringRef file = SM.getBufferData(locInfo.first, &invalidTemp);
if (invalidTemp)
return SourceLocation();
const char *tokenBegin = file.data() + locInfo.second;
// Lex from the start of the given location.
Lexer lexer(SM.getLocForStartOfFile(locInfo.first),
Ctx.getLangOptions(),
file.begin(), tokenBegin, file.end());
Token tok;
lexer.LexFromRawLexer(tok);
if (tok.isNot(tok::semi))
return SourceLocation();
return tok.getLocation();
}
Cl Expr::ClassifyImpl(ASTContext &Ctx, SourceLocation *Loc) const {
assert(!TR->isReferenceType() && "Expressions can't have reference type.");
Cl::Kinds kind = ClassifyInternal(Ctx, this);
// C99 6.3.2.1: An lvalue is an expression with an object type or an
// incomplete type other than void.
if (!Ctx.getLangOptions().CPlusPlus) {
// Thus, no functions.
if (TR->isFunctionType() || TR == Ctx.OverloadTy)
kind = Cl::CL_Function;
// No void either, but qualified void is OK because it is "other than void".
else if (TR->isVoidType() && !Ctx.getCanonicalType(TR).hasQualifiers())
kind = Cl::CL_Void;
}
// Enable this assertion for testing.
switch (kind) {
case Cl::CL_LValue: assert(getValueKind() == VK_LValue); break;
case Cl::CL_XValue: assert(getValueKind() == VK_XValue); break;
case Cl::CL_Function:
case Cl::CL_Void:
case Cl::CL_DuplicateVectorComponents:
case Cl::CL_MemberFunction:
case Cl::CL_SubObjCPropertySetting:
case Cl::CL_ClassTemporary:
case Cl::CL_PRValue: assert(getValueKind() == VK_RValue); break;
}
Cl::ModifiableType modifiable = Cl::CM_Untested;
if (Loc)
modifiable = IsModifiable(Ctx, this, kind, *Loc);
return Classification(kind, modifiable);
}
bool trans::canApplyWeak(ASTContext &Ctx, QualType type,
bool AllowOnUnknownClass) {
if (!Ctx.getLangOptions().ObjCRuntimeHasWeak)
return false;
QualType T = type;
if (T.isNull())
return false;
while (const PointerType *ptr = T->getAs<PointerType>())
T = ptr->getPointeeType();
if (const ObjCObjectPointerType *ObjT = T->getAs<ObjCObjectPointerType>()) {
ObjCInterfaceDecl *Class = ObjT->getInterfaceDecl();
if (!AllowOnUnknownClass && (!Class || Class->getName() == "NSObject"))
return false; // id/NSObject is not safe for weak.
if (!AllowOnUnknownClass && Class->isForwardDecl())
return false; // forward classes are not verifiable, therefore not safe.
if (Class->isArcWeakrefUnavailable())
return false;
if (isClassInWeakBlacklist(Class))
return false;
}
return true;
}
/// \brief Returns a value indicating whether this function
/// corresponds to a builtin function.
///
/// The function corresponds to a built-in function if it is
/// declared at translation scope or within an extern "C" block and
/// its name matches with the name of a builtin. The returned value
/// will be 0 for functions that do not correspond to a builtin, a
/// value of type \c Builtin::ID if in the target-independent range
/// \c [1,Builtin::First), or a target-specific builtin value.
unsigned FunctionDecl::getBuiltinID(ASTContext &Context) const {
if (!getIdentifier() || !getIdentifier()->getBuiltinID())
return 0;
unsigned BuiltinID = getIdentifier()->getBuiltinID();
if (!Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID))
return BuiltinID;
// This function has the name of a known C library
// function. Determine whether it actually refers to the C library
// function or whether it just has the same name.
// If this is a static function, it's not a builtin.
if (getStorageClass() == Static)
return 0;
// If this function is at translation-unit scope and we're not in
// C++, it refers to the C library function.
if (!Context.getLangOptions().CPlusPlus &&
getDeclContext()->isTranslationUnit())
return BuiltinID;
// If the function is in an extern "C" linkage specification and is
// not marked "overloadable", it's the real function.
if (isa<LinkageSpecDecl>(getDeclContext()) &&
cast<LinkageSpecDecl>(getDeclContext())->getLanguage()
== LinkageSpecDecl::lang_c &&
!getAttr<OverloadableAttr>())
return BuiltinID;
// Not a builtin
return 0;
}
static Cl::Kinds ClassifyBinaryOp(ASTContext &Ctx, const BinaryOperator *E) {
assert(Ctx.getLangOptions().CPlusPlus &&
"This is only relevant for C++.");
// C++ [expr.ass]p1: All [...] return an lvalue referring to the left operand.
// Except we override this for writes to ObjC properties.
if (E->isAssignmentOp())
return (E->getLHS()->getObjectKind() == OK_ObjCProperty
? Cl::CL_PRValue : Cl::CL_LValue);
// C++ [expr.comma]p1: the result is of the same value category as its right
// operand, [...].
if (E->getOpcode() == BO_Comma)
return ClassifyInternal(Ctx, E->getRHS());
// C++ [expr.mptr.oper]p6: The result of a .* expression whose second operand
// is a pointer to a data member is of the same value category as its first
// operand.
if (E->getOpcode() == BO_PtrMemD)
return E->getType()->isFunctionType() ? Cl::CL_MemberFunction :
ClassifyInternal(Ctx, E->getLHS());
// C++ [expr.mptr.oper]p6: The result of an ->* expression is an lvalue if its
// second operand is a pointer to data member and a prvalue otherwise.
if (E->getOpcode() == BO_PtrMemI)
return E->getType()->isFunctionType() ?
Cl::CL_MemberFunction : Cl::CL_LValue;
// All other binary operations are prvalues.
return Cl::CL_PRValue;
}
/// isRequiredDecl - Check if this is a "required" Decl, which must be seen by
/// consumers of the AST.
///
/// Such decls will always be deserialized from the PCH file, so we would like
/// this to be as restrictive as possible. Currently the predicate is driven by
/// code generation requirements, if other clients have a different notion of
/// what is "required" then we may have to consider an alternate scheme where
/// clients can iterate over the top-level decls and get information on them,
/// without necessary deserializing them. We could explicitly require such
/// clients to use a separate API call to "realize" the decl. This should be
/// relatively painless since they would presumably only do it for top-level
/// decls.
//
// FIXME: This predicate is essentially IRgen's predicate to determine whether a
// declaration can be deferred. Merge them somehow.
static bool isRequiredDecl(const Decl *D, ASTContext &Context) {
// File scoped assembly must be seen.
if (isa<FileScopeAsmDecl>(D))
return true;
// Otherwise if this isn't a function or a file scoped variable it doesn't
// need to be seen.
if (const VarDecl *VD = dyn_cast<VarDecl>(D)) {
if (!VD->isFileVarDecl())
return false;
} else if (!isa<FunctionDecl>(D))
return false;
// Aliases and used decls must be seen.
if (D->hasAttr<AliasAttr>() || D->hasAttr<UsedAttr>())
return true;
if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
// Forward declarations don't need to be seen.
if (!FD->isThisDeclarationADefinition())
return false;
// Constructors and destructors must be seen.
if (FD->hasAttr<ConstructorAttr>() || FD->hasAttr<DestructorAttr>())
return true;
// Otherwise, this is required unless it is static.
//
// FIXME: Inlines.
return FD->getStorageClass() != FunctionDecl::Static;
} else {
const VarDecl *VD = cast<VarDecl>(D);
// In C++, this doesn't need to be seen if it is marked "extern".
if (Context.getLangOptions().CPlusPlus && !VD->getInit() &&
(VD->getStorageClass() == VarDecl::Extern ||
VD->isExternC()))
return false;
// In C, this doesn't need to be seen unless it is a definition.
if (!Context.getLangOptions().CPlusPlus && !VD->getInit())
return false;
// Otherwise, this is required unless it is static.
return VD->getStorageClass() != VarDecl::Static;
}
}
bool VarDecl::isTentativeDefinition(ASTContext &Context) const {
if (!isFileVarDecl() || Context.getLangOptions().CPlusPlus)
return false;
const VarDecl *Def = 0;
return (!getDefinition(Def) &&
(getStorageClass() == None || getStorageClass() == Static));
}
static Cl::Kinds ClassifyMemberExpr(ASTContext &Ctx, const MemberExpr *E) {
if (E->getType() == Ctx.UnknownAnyTy)
return (isa<FunctionDecl>(E->getMemberDecl())
? Cl::CL_PRValue : Cl::CL_LValue);
// Handle C first, it's easier.
if (!Ctx.getLangOptions().CPlusPlus) {
// C99 6.5.2.3p3
// For dot access, the expression is an lvalue if the first part is. For
// arrow access, it always is an lvalue.
if (E->isArrow())
return Cl::CL_LValue;
// ObjC property accesses are not lvalues, but get special treatment.
Expr *Base = E->getBase()->IgnoreParens();
if (isa<ObjCPropertyRefExpr>(Base))
return Cl::CL_SubObjCPropertySetting;
return ClassifyInternal(Ctx, Base);
}
NamedDecl *Member = E->getMemberDecl();
// C++ [expr.ref]p3: E1->E2 is converted to the equivalent form (*(E1)).E2.
// C++ [expr.ref]p4: If E2 is declared to have type "reference to T", then
// E1.E2 is an lvalue.
if (ValueDecl *Value = dyn_cast<ValueDecl>(Member))
if (Value->getType()->isReferenceType())
return Cl::CL_LValue;
// Otherwise, one of the following rules applies.
// -- If E2 is a static member [...] then E1.E2 is an lvalue.
if (isa<VarDecl>(Member) && Member->getDeclContext()->isRecord())
return Cl::CL_LValue;
// -- If E2 is a non-static data member [...]. If E1 is an lvalue, then
// E1.E2 is an lvalue; if E1 is an xvalue, then E1.E2 is an xvalue;
// otherwise, it is a prvalue.
if (isa<FieldDecl>(Member)) {
// *E1 is an lvalue
if (E->isArrow())
return Cl::CL_LValue;
Expr *Base = E->getBase()->IgnoreParenImpCasts();
if (isa<ObjCPropertyRefExpr>(Base))
return Cl::CL_SubObjCPropertySetting;
return ClassifyInternal(Ctx, E->getBase());
}
// -- If E2 is a [...] member function, [...]
// -- If it refers to a static member function [...], then E1.E2 is an
// lvalue; [...]
// -- Otherwise [...] E1.E2 is a prvalue.
if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Member))
return Method->isStatic() ? Cl::CL_LValue : Cl::CL_MemberFunction;
// -- If E2 is a member enumerator [...], the expression E1.E2 is a prvalue.
// So is everything else we haven't handled yet.
return Cl::CL_PRValue;
}
/// ClassifyUnnamed - Return the classification of an expression yielding an
/// unnamed value of the given type. This applies in particular to function
/// calls and casts.
static Cl::Kinds ClassifyUnnamed(ASTContext &Ctx, QualType T) {
// In C, function calls are always rvalues.
if (!Ctx.getLangOptions().CPlusPlus) return Cl::CL_PRValue;
// C++ [expr.call]p10: A function call is an lvalue if the result type is an
// lvalue reference type or an rvalue reference to function type, an xvalue
// if the result type is an rvalue refernence to object type, and a prvalue
// otherwise.
if (T->isLValueReferenceType())
return Cl::CL_LValue;
const RValueReferenceType *RV = T->getAs<RValueReferenceType>();
if (!RV) // Could still be a class temporary, though.
return T->isRecordType() ? Cl::CL_ClassTemporary : Cl::CL_PRValue;
return RV->getPointeeType()->isFunctionType() ? Cl::CL_LValue : Cl::CL_XValue;
}
bool FunctionDecl::isExternC(ASTContext &Context) const {
// In C, any non-static, non-overloadable function has external
// linkage.
if (!Context.getLangOptions().CPlusPlus)
return getStorageClass() != Static && !getAttr<OverloadableAttr>();
for (const DeclContext *DC = getDeclContext(); !DC->isTranslationUnit();
DC = DC->getParent()) {
if (const LinkageSpecDecl *Linkage = dyn_cast<LinkageSpecDecl>(DC)) {
if (Linkage->getLanguage() == LinkageSpecDecl::lang_c)
return getStorageClass() != Static &&
!getAttr<OverloadableAttr>();
break;
}
}
return false;
}
static void printSourceRange(CharSourceRange range, ASTContext &Ctx,
raw_ostream &OS) {
SourceManager &SM = Ctx.getSourceManager();
const LangOptions &langOpts = Ctx.getLangOptions();
PresumedLoc PL = SM.getPresumedLoc(range.getBegin());
OS << llvm::sys::path::filename(PL.getFilename());
OS << " [" << PL.getLine() << ":"
<< PL.getColumn();
OS << " - ";
SourceLocation end = range.getEnd();
PL = SM.getPresumedLoc(end);
unsigned endCol = PL.getColumn() - 1;
if (!range.isTokenRange())
endCol += Lexer::MeasureTokenLength(end, SM, langOpts);
OS << PL.getLine() << ":" << endCol << "]";
}
static Cl::Kinds ClassifyConditional(ASTContext &Ctx, const Expr *True,
const Expr *False) {
assert(Ctx.getLangOptions().CPlusPlus &&
"This is only relevant for C++.");
// C++ [expr.cond]p2
// If either the second or the third operand has type (cv) void, [...]
// the result [...] is a prvalue.
if (True->getType()->isVoidType() || False->getType()->isVoidType())
return Cl::CL_PRValue;
// Note that at this point, we have already performed all conversions
// according to [expr.cond]p3.
// C++ [expr.cond]p4: If the second and third operands are glvalues of the
// same value category [...], the result is of that [...] value category.
// C++ [expr.cond]p5: Otherwise, the result is a prvalue.
Cl::Kinds LCl = ClassifyInternal(Ctx, True),
RCl = ClassifyInternal(Ctx, False);
return LCl == RCl ? LCl : Cl::CL_PRValue;
}
Cl Expr::ClassifyImpl(ASTContext &Ctx, SourceLocation *Loc) const {
assert(!TR->isReferenceType() && "Expressions can't have reference type.");
Cl::Kinds kind = ClassifyInternal(Ctx, this);
// C99 6.3.2.1: An lvalue is an expression with an object type or an
// incomplete type other than void.
if (!Ctx.getLangOptions().CPlusPlus) {
// Thus, no functions.
if (TR->isFunctionType() || TR == Ctx.OverloadTy)
kind = Cl::CL_Function;
// No void either, but qualified void is OK because it is "other than void".
else if (TR->isVoidType() && !Ctx.getCanonicalType(TR).hasQualifiers())
kind = Cl::CL_Void;
}
Cl::ModifiableType modifiable = Cl::CM_Untested;
if (Loc)
modifiable = IsModifiable(Ctx, this, kind, *Loc);
return Classification(kind, modifiable);
}
bool VarDecl::isExternC(ASTContext &Context) const {
if (!Context.getLangOptions().CPlusPlus)
return (getDeclContext()->isTranslationUnit() &&
getStorageClass() != Static) ||
(getDeclContext()->isFunctionOrMethod() && hasExternalStorage());
for (const DeclContext *DC = getDeclContext(); !DC->isTranslationUnit();
DC = DC->getParent()) {
if (const LinkageSpecDecl *Linkage = dyn_cast<LinkageSpecDecl>(DC)) {
if (Linkage->getLanguage() == LinkageSpecDecl::lang_c)
return getStorageClass() != Static;
break;
}
if (DC->isFunctionOrMethod())
return false;
}
return false;
}
/// ClassifyDecl - Return the classification of an expression referencing the
/// given declaration.
static Cl::Kinds ClassifyDecl(ASTContext &Ctx, const Decl *D) {
// C++ [expr.prim.general]p6: The result is an lvalue if the entity is a
// function, variable, or data member and a prvalue otherwise.
// In C, functions are not lvalues.
// In addition, NonTypeTemplateParmDecl derives from VarDecl but isn't an
// lvalue unless it's a reference type (C++ [temp.param]p6), so we need to
// special-case this.
if (isa<CXXMethodDecl>(D) && cast<CXXMethodDecl>(D)->isInstance())
return Cl::CL_MemberFunction;
bool islvalue;
if (const NonTypeTemplateParmDecl *NTTParm =
dyn_cast<NonTypeTemplateParmDecl>(D))
islvalue = NTTParm->getType()->isReferenceType();
else
islvalue = isa<VarDecl>(D) || isa<FieldDecl>(D) ||
(Ctx.getLangOptions().CPlusPlus &&
(isa<FunctionDecl>(D) || isa<FunctionTemplateDecl>(D)));
return islvalue ? Cl::CL_LValue : Cl::CL_PRValue;
}
static Cl::ModifiableType IsModifiable(ASTContext &Ctx, const Expr *E,
Cl::Kinds Kind, SourceLocation &Loc) {
// As a general rule, we only care about lvalues. But there are some rvalues
// for which we want to generate special results.
if (Kind == Cl::CL_PRValue) {
// For the sake of better diagnostics, we want to specifically recognize
// use of the GCC cast-as-lvalue extension.
if (const ExplicitCastExpr *CE =
dyn_cast<ExplicitCastExpr>(E->IgnoreParens())) {
if (CE->getSubExpr()->IgnoreParenImpCasts()->isLValue()) {
Loc = CE->getExprLoc();
return Cl::CM_LValueCast;
}
}
}
if (Kind != Cl::CL_LValue)
return Cl::CM_RValue;
// This is the lvalue case.
// Functions are lvalues in C++, but not modifiable. (C++ [basic.lval]p6)
if (Ctx.getLangOptions().CPlusPlus && E->getType()->isFunctionType())
return Cl::CM_Function;
// You cannot assign to a variable outside a block from within the block if
// it is not marked __block, e.g.
// void takeclosure(void (^C)(void));
// void func() { int x = 1; takeclosure(^{ x = 7; }); }
if (const BlockDeclRefExpr *BDR = dyn_cast<BlockDeclRefExpr>(E)) {
if (!BDR->isByRef() && isa<VarDecl>(BDR->getDecl()))
return Cl::CM_NotBlockQualified;
}
// Assignment to a property in ObjC is an implicit setter access. But a
// setter might not exist.
if (const ObjCPropertyRefExpr *Expr = dyn_cast<ObjCPropertyRefExpr>(E)) {
if (Expr->isImplicitProperty() && Expr->getImplicitPropertySetter() == 0)
return Cl::CM_NoSetterProperty;
}
CanQualType CT = Ctx.getCanonicalType(E->getType());
// Const stuff is obviously not modifiable.
if (CT.isConstQualified())
return Cl::CM_ConstQualified;
// Arrays are not modifiable, only their elements are.
if (CT->isArrayType())
return Cl::CM_ArrayType;
// Incomplete types are not modifiable.
if (CT->isIncompleteType())
return Cl::CM_IncompleteType;
// Records with any const fields (recursively) are not modifiable.
if (const RecordType *R = CT->getAs<RecordType>()) {
assert((E->getObjectKind() == OK_ObjCProperty ||
!Ctx.getLangOptions().CPlusPlus) &&
"C++ struct assignment should be resolved by the "
"copy assignment operator.");
if (R->hasConstFields())
return Cl::CM_ConstQualified;
}
return Cl::CM_Modifiable;
}
bool FunctionDecl::isMain(ASTContext &Context) const {
return !Context.getLangOptions().Freestanding &&
getDeclContext()->getLookupContext()->isTranslationUnit() &&
getIdentifier() && getIdentifier()->isStr("main");
}
static Cl::Kinds ClassifyInternal(ASTContext &Ctx, const Expr *E) {
// This function takes the first stab at classifying expressions.
const LangOptions &Lang = Ctx.getLangOptions();
switch (E->getStmtClass()) {
// First come the expressions that are always lvalues, unconditionally.
case Expr::ObjCIsaExprClass:
// C++ [expr.prim.general]p1: A string literal is an lvalue.
case Expr::StringLiteralClass:
// @encode is equivalent to its string
case Expr::ObjCEncodeExprClass:
// __func__ and friends are too.
case Expr::PredefinedExprClass:
// Property references are lvalues
case Expr::ObjCPropertyRefExprClass:
case Expr::ObjCImplicitSetterGetterRefExprClass:
// C++ [expr.typeid]p1: The result of a typeid expression is an lvalue of...
case Expr::CXXTypeidExprClass:
// Unresolved lookups get classified as lvalues.
// FIXME: Is this wise? Should they get their own kind?
case Expr::UnresolvedLookupExprClass:
case Expr::UnresolvedMemberExprClass:
// ObjC instance variables are lvalues
// FIXME: ObjC++0x might have different rules
case Expr::ObjCIvarRefExprClass:
// C99 6.5.2.5p5 says that compound literals are lvalues.
// FIXME: C++ might have a different opinion.
case Expr::CompoundLiteralExprClass:
return Cl::CL_LValue;
// Next come the complicated cases.
// C++ [expr.sub]p1: The result is an lvalue of type "T".
// However, subscripting vector types is more like member access.
case Expr::ArraySubscriptExprClass:
if (cast<ArraySubscriptExpr>(E)->getBase()->getType()->isVectorType())
return ClassifyInternal(Ctx, cast<ArraySubscriptExpr>(E)->getBase());
return Cl::CL_LValue;
// C++ [expr.prim.general]p3: The result is an lvalue if the entity is a
// function or variable and a prvalue otherwise.
case Expr::DeclRefExprClass:
return ClassifyDecl(Ctx, cast<DeclRefExpr>(E)->getDecl());
// We deal with names referenced from blocks the same way.
case Expr::BlockDeclRefExprClass:
return ClassifyDecl(Ctx, cast<BlockDeclRefExpr>(E)->getDecl());
// Member access is complex.
case Expr::MemberExprClass:
return ClassifyMemberExpr(Ctx, cast<MemberExpr>(E));
case Expr::UnaryOperatorClass:
switch (cast<UnaryOperator>(E)->getOpcode()) {
// C++ [expr.unary.op]p1: The unary * operator performs indirection:
// [...] the result is an lvalue referring to the object or function
// to which the expression points.
case UO_Deref:
return Cl::CL_LValue;
// GNU extensions, simply look through them.
case UO_Real:
case UO_Imag:
case UO_Extension:
return ClassifyInternal(Ctx, cast<UnaryOperator>(E)->getSubExpr());
// C++ [expr.pre.incr]p1: The result is the updated operand; it is an
// lvalue, [...]
// Not so in C.
case UO_PreInc:
case UO_PreDec:
return Lang.CPlusPlus ? Cl::CL_LValue : Cl::CL_PRValue;
default:
return Cl::CL_PRValue;
}
// Implicit casts are lvalues if they're lvalue casts. Other than that, we
// only specifically record class temporaries.
case Expr::ImplicitCastExprClass:
switch (cast<ImplicitCastExpr>(E)->getValueKind()) {
case VK_RValue:
return Lang.CPlusPlus && E->getType()->isRecordType() ?
Cl::CL_ClassTemporary : Cl::CL_PRValue;
case VK_LValue:
return Cl::CL_LValue;
case VK_XValue:
return Cl::CL_XValue;
}
llvm_unreachable("Invalid value category of implicit cast.");
// C++ [expr.prim.general]p4: The presence of parentheses does not affect
// whether the expression is an lvalue.
case Expr::ParenExprClass:
return ClassifyInternal(Ctx, cast<ParenExpr>(E)->getSubExpr());
case Expr::BinaryOperatorClass:
case Expr::CompoundAssignOperatorClass:
// C doesn't have any binary expressions that are lvalues.
if (Lang.CPlusPlus)
return ClassifyBinaryOp(Ctx, cast<BinaryOperator>(E));
return Cl::CL_PRValue;
case Expr::CallExprClass:
case Expr::CXXOperatorCallExprClass:
case Expr::CXXMemberCallExprClass:
return ClassifyUnnamed(Ctx, cast<CallExpr>(E)->getCallReturnType());
// __builtin_choose_expr is equivalent to the chosen expression.
case Expr::ChooseExprClass:
return ClassifyInternal(Ctx, cast<ChooseExpr>(E)->getChosenSubExpr(Ctx));
// Extended vector element access is an lvalue unless there are duplicates
// in the shuffle expression.
case Expr::ExtVectorElementExprClass:
return cast<ExtVectorElementExpr>(E)->containsDuplicateElements() ?
Cl::CL_DuplicateVectorComponents : Cl::CL_LValue;
// Simply look at the actual default argument.
case Expr::CXXDefaultArgExprClass:
return ClassifyInternal(Ctx, cast<CXXDefaultArgExpr>(E)->getExpr());
// Same idea for temporary binding.
case Expr::CXXBindTemporaryExprClass:
return ClassifyInternal(Ctx, cast<CXXBindTemporaryExpr>(E)->getSubExpr());
// And the temporary lifetime guard.
case Expr::CXXExprWithTemporariesClass:
return ClassifyInternal(Ctx, cast<CXXExprWithTemporaries>(E)->getSubExpr());
// Casts depend completely on the target type. All casts work the same.
case Expr::CStyleCastExprClass:
case Expr::CXXFunctionalCastExprClass:
case Expr::CXXStaticCastExprClass:
case Expr::CXXDynamicCastExprClass:
case Expr::CXXReinterpretCastExprClass:
case Expr::CXXConstCastExprClass:
// Only in C++ can casts be interesting at all.
if (!Lang.CPlusPlus) return Cl::CL_PRValue;
return ClassifyUnnamed(Ctx, cast<ExplicitCastExpr>(E)->getTypeAsWritten());
case Expr::ConditionalOperatorClass:
// Once again, only C++ is interesting.
if (!Lang.CPlusPlus) return Cl::CL_PRValue;
return ClassifyConditional(Ctx, cast<ConditionalOperator>(E));
// ObjC message sends are effectively function calls, if the target function
// is known.
case Expr::ObjCMessageExprClass:
if (const ObjCMethodDecl *Method =
cast<ObjCMessageExpr>(E)->getMethodDecl()) {
return ClassifyUnnamed(Ctx, Method->getResultType());
}
// Some C++ expressions are always class temporaries.
case Expr::CXXConstructExprClass:
case Expr::CXXTemporaryObjectExprClass:
case Expr::CXXScalarValueInitExprClass:
return Cl::CL_ClassTemporary;
// Everything we haven't handled is a prvalue.
default:
return Cl::CL_PRValue;
}
}
static Cl::Kinds ClassifyInternal(ASTContext &Ctx, const Expr *E) {
// This function takes the first stab at classifying expressions.
const LangOptions &Lang = Ctx.getLangOptions();
switch (E->getStmtClass()) {
// First come the expressions that are always lvalues, unconditionally.
case Stmt::NoStmtClass:
#define ABSTRACT_STMT(Kind)
#define STMT(Kind, Base) case Expr::Kind##Class:
#define EXPR(Kind, Base)
#include "clang/AST/StmtNodes.inc"
llvm_unreachable("cannot classify a statement");
break;
case Expr::ObjCIsaExprClass:
// C++ [expr.prim.general]p1: A string literal is an lvalue.
case Expr::StringLiteralClass:
// @encode is equivalent to its string
case Expr::ObjCEncodeExprClass:
// __func__ and friends are too.
case Expr::PredefinedExprClass:
// Property references are lvalues
case Expr::ObjCPropertyRefExprClass:
// C++ [expr.typeid]p1: The result of a typeid expression is an lvalue of...
case Expr::CXXTypeidExprClass:
// Unresolved lookups get classified as lvalues.
// FIXME: Is this wise? Should they get their own kind?
case Expr::UnresolvedLookupExprClass:
case Expr::UnresolvedMemberExprClass:
case Expr::CXXDependentScopeMemberExprClass:
case Expr::CXXUnresolvedConstructExprClass:
case Expr::DependentScopeDeclRefExprClass:
// ObjC instance variables are lvalues
// FIXME: ObjC++0x might have different rules
case Expr::ObjCIvarRefExprClass:
return Cl::CL_LValue;
// C99 6.5.2.5p5 says that compound literals are lvalues.
// In C++, they're class temporaries.
case Expr::CompoundLiteralExprClass:
return Ctx.getLangOptions().CPlusPlus? Cl::CL_ClassTemporary
: Cl::CL_LValue;
// Expressions that are prvalues.
case Expr::CXXBoolLiteralExprClass:
case Expr::CXXPseudoDestructorExprClass:
case Expr::SizeOfAlignOfExprClass:
case Expr::CXXNewExprClass:
case Expr::CXXThisExprClass:
case Expr::CXXNullPtrLiteralExprClass:
case Expr::ImaginaryLiteralClass:
case Expr::GNUNullExprClass:
case Expr::OffsetOfExprClass:
case Expr::CXXThrowExprClass:
case Expr::ShuffleVectorExprClass:
case Expr::IntegerLiteralClass:
case Expr::CharacterLiteralClass:
case Expr::AddrLabelExprClass:
case Expr::CXXDeleteExprClass:
case Expr::ImplicitValueInitExprClass:
case Expr::BlockExprClass:
case Expr::FloatingLiteralClass:
case Expr::CXXNoexceptExprClass:
case Expr::CXXScalarValueInitExprClass:
case Expr::UnaryTypeTraitExprClass:
case Expr::BinaryTypeTraitExprClass:
case Expr::ObjCSelectorExprClass:
case Expr::ObjCProtocolExprClass:
case Expr::ObjCStringLiteralClass:
case Expr::ParenListExprClass:
case Expr::InitListExprClass:
case Expr::SizeOfPackExprClass:
case Expr::SubstNonTypeTemplateParmPackExprClass:
return Cl::CL_PRValue;
// Next come the complicated cases.
// C++ [expr.sub]p1: The result is an lvalue of type "T".
// However, subscripting vector types is more like member access.
case Expr::ArraySubscriptExprClass:
if (cast<ArraySubscriptExpr>(E)->getBase()->getType()->isVectorType())
return ClassifyInternal(Ctx, cast<ArraySubscriptExpr>(E)->getBase());
return Cl::CL_LValue;
// C++ [expr.prim.general]p3: The result is an lvalue if the entity is a
// function or variable and a prvalue otherwise.
case Expr::DeclRefExprClass:
return ClassifyDecl(Ctx, cast<DeclRefExpr>(E)->getDecl());
// We deal with names referenced from blocks the same way.
case Expr::BlockDeclRefExprClass:
return ClassifyDecl(Ctx, cast<BlockDeclRefExpr>(E)->getDecl());
// Member access is complex.
case Expr::MemberExprClass:
return ClassifyMemberExpr(Ctx, cast<MemberExpr>(E));
case Expr::UnaryOperatorClass:
switch (cast<UnaryOperator>(E)->getOpcode()) {
// C++ [expr.unary.op]p1: The unary * operator performs indirection:
// [...] the result is an lvalue referring to the object or function
// to which the expression points.
case UO_Deref:
return Cl::CL_LValue;
// GNU extensions, simply look through them.
case UO_Extension:
return ClassifyInternal(Ctx, cast<UnaryOperator>(E)->getSubExpr());
// Treat _Real and _Imag basically as if they were member
// expressions: l-value only if the operand is a true l-value.
case UO_Real:
case UO_Imag: {
const Expr *Op = cast<UnaryOperator>(E)->getSubExpr()->IgnoreParens();
Cl::Kinds K = ClassifyInternal(Ctx, Op);
if (K != Cl::CL_LValue) return K;
if (isa<ObjCPropertyRefExpr>(Op))
return Cl::CL_SubObjCPropertySetting;
return Cl::CL_LValue;
}
// C++ [expr.pre.incr]p1: The result is the updated operand; it is an
// lvalue, [...]
// Not so in C.
case UO_PreInc:
case UO_PreDec:
return Lang.CPlusPlus ? Cl::CL_LValue : Cl::CL_PRValue;
default:
return Cl::CL_PRValue;
}
case Expr::OpaqueValueExprClass:
return ClassifyExprValueKind(Lang, E,
cast<OpaqueValueExpr>(E)->getValueKind());
// Implicit casts are lvalues if they're lvalue casts. Other than that, we
// only specifically record class temporaries.
case Expr::ImplicitCastExprClass:
return ClassifyExprValueKind(Lang, E,
cast<ImplicitCastExpr>(E)->getValueKind());
// C++ [expr.prim.general]p4: The presence of parentheses does not affect
// whether the expression is an lvalue.
case Expr::ParenExprClass:
return ClassifyInternal(Ctx, cast<ParenExpr>(E)->getSubExpr());
case Expr::BinaryOperatorClass:
case Expr::CompoundAssignOperatorClass:
// C doesn't have any binary expressions that are lvalues.
if (Lang.CPlusPlus)
return ClassifyBinaryOp(Ctx, cast<BinaryOperator>(E));
return Cl::CL_PRValue;
case Expr::CallExprClass:
case Expr::CXXOperatorCallExprClass:
case Expr::CXXMemberCallExprClass:
case Expr::CUDAKernelCallExprClass:
return ClassifyUnnamed(Ctx, cast<CallExpr>(E)->getCallReturnType());
// __builtin_choose_expr is equivalent to the chosen expression.
case Expr::ChooseExprClass:
return ClassifyInternal(Ctx, cast<ChooseExpr>(E)->getChosenSubExpr(Ctx));
// Extended vector element access is an lvalue unless there are duplicates
// in the shuffle expression.
case Expr::ExtVectorElementExprClass:
return cast<ExtVectorElementExpr>(E)->containsDuplicateElements() ?
Cl::CL_DuplicateVectorComponents : Cl::CL_LValue;
// Simply look at the actual default argument.
case Expr::CXXDefaultArgExprClass:
return ClassifyInternal(Ctx, cast<CXXDefaultArgExpr>(E)->getExpr());
// Same idea for temporary binding.
case Expr::CXXBindTemporaryExprClass:
return ClassifyInternal(Ctx, cast<CXXBindTemporaryExpr>(E)->getSubExpr());
// And the cleanups guard.
case Expr::ExprWithCleanupsClass:
return ClassifyInternal(Ctx, cast<ExprWithCleanups>(E)->getSubExpr());
// Casts depend completely on the target type. All casts work the same.
case Expr::CStyleCastExprClass:
case Expr::CXXFunctionalCastExprClass:
case Expr::CXXStaticCastExprClass:
case Expr::CXXDynamicCastExprClass:
case Expr::CXXReinterpretCastExprClass:
case Expr::CXXConstCastExprClass:
// Only in C++ can casts be interesting at all.
if (!Lang.CPlusPlus) return Cl::CL_PRValue;
return ClassifyUnnamed(Ctx, cast<ExplicitCastExpr>(E)->getTypeAsWritten());
case Expr::BinaryConditionalOperatorClass: {
if (!Lang.CPlusPlus) return Cl::CL_PRValue;
const BinaryConditionalOperator *co = cast<BinaryConditionalOperator>(E);
return ClassifyConditional(Ctx, co->getTrueExpr(), co->getFalseExpr());
}
case Expr::ConditionalOperatorClass: {
// Once again, only C++ is interesting.
if (!Lang.CPlusPlus) return Cl::CL_PRValue;
const ConditionalOperator *co = cast<ConditionalOperator>(E);
return ClassifyConditional(Ctx, co->getTrueExpr(), co->getFalseExpr());
}
// ObjC message sends are effectively function calls, if the target function
// is known.
case Expr::ObjCMessageExprClass:
if (const ObjCMethodDecl *Method =
cast<ObjCMessageExpr>(E)->getMethodDecl()) {
return ClassifyUnnamed(Ctx, Method->getResultType());
}
return Cl::CL_PRValue;
// Some C++ expressions are always class temporaries.
case Expr::CXXConstructExprClass:
case Expr::CXXTemporaryObjectExprClass:
return Cl::CL_ClassTemporary;
case Expr::VAArgExprClass:
return ClassifyUnnamed(Ctx, E->getType());
case Expr::DesignatedInitExprClass:
return ClassifyInternal(Ctx, cast<DesignatedInitExpr>(E)->getInit());
case Expr::StmtExprClass: {
const CompoundStmt *S = cast<StmtExpr>(E)->getSubStmt();
if (const Expr *LastExpr = dyn_cast_or_null<Expr>(S->body_back()))
return ClassifyUnnamed(Ctx, LastExpr->getType());
return Cl::CL_PRValue;
}
case Expr::CXXUuidofExprClass:
return Cl::CL_LValue;
case Expr::PackExpansionExprClass:
return ClassifyInternal(Ctx, cast<PackExpansionExpr>(E)->getPattern());
}
llvm_unreachable("unhandled expression kind in classification");
return Cl::CL_LValue;
}
void HTMLPrinter::Initialize(ASTContext &context) {
R.setSourceMgr(context.getSourceManager(), context.getLangOptions());
}