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Diffstat (limited to 'gnu/llvm/tools/clang/lib/AST/ExprClassification.cpp')
| -rw-r--r-- | gnu/llvm/tools/clang/lib/AST/ExprClassification.cpp | 707 |
1 files changed, 0 insertions, 707 deletions
diff --git a/gnu/llvm/tools/clang/lib/AST/ExprClassification.cpp b/gnu/llvm/tools/clang/lib/AST/ExprClassification.cpp deleted file mode 100644 index e1d6a1c9edc..00000000000 --- a/gnu/llvm/tools/clang/lib/AST/ExprClassification.cpp +++ /dev/null @@ -1,707 +0,0 @@ -//===- ExprClassification.cpp - Expression AST Node Implementation --------===// -// -// The LLVM Compiler Infrastructure -// -// This file is distributed under the University of Illinois Open Source -// License. See LICENSE.TXT for details. -// -//===----------------------------------------------------------------------===// -// -// This file implements Expr::classify. -// -//===----------------------------------------------------------------------===// - -#include "clang/AST/Expr.h" -#include "clang/AST/ASTContext.h" -#include "clang/AST/DeclCXX.h" -#include "clang/AST/DeclObjC.h" -#include "clang/AST/DeclTemplate.h" -#include "clang/AST/ExprCXX.h" -#include "clang/AST/ExprObjC.h" -#include "llvm/Support/ErrorHandling.h" - -using namespace clang; - -using Cl = Expr::Classification; - -static Cl::Kinds ClassifyInternal(ASTContext &Ctx, const Expr *E); -static Cl::Kinds ClassifyDecl(ASTContext &Ctx, const Decl *D); -static Cl::Kinds ClassifyUnnamed(ASTContext &Ctx, QualType T); -static Cl::Kinds ClassifyMemberExpr(ASTContext &Ctx, const MemberExpr *E); -static Cl::Kinds ClassifyBinaryOp(ASTContext &Ctx, const BinaryOperator *E); -static Cl::Kinds ClassifyConditional(ASTContext &Ctx, - const Expr *trueExpr, - const Expr *falseExpr); -static Cl::ModifiableType IsModifiable(ASTContext &Ctx, const Expr *E, - Cl::Kinds Kind, SourceLocation &Loc); - -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.getLangOpts().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". - // Void "lvalues" are classified as addressable void values, which are void - // expressions whose address can be taken. - else if (TR->isVoidType() && !TR.hasQualifiers()) - kind = (kind == Cl::CL_LValue ? Cl::CL_AddressableVoid : 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_AddressableVoid: - case Cl::CL_DuplicateVectorComponents: - case Cl::CL_MemberFunction: - case Cl::CL_SubObjCPropertySetting: - case Cl::CL_ClassTemporary: - case Cl::CL_ArrayTemporary: - case Cl::CL_ObjCMessageRValue: - 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); -} - -/// Classify an expression which creates a temporary, based on its type. -static Cl::Kinds ClassifyTemporary(QualType T) { - if (T->isRecordType()) - return Cl::CL_ClassTemporary; - if (T->isArrayType()) - return Cl::CL_ArrayTemporary; - - // No special classification: these don't behave differently from normal - // prvalues. - return Cl::CL_PRValue; -} - -static Cl::Kinds ClassifyExprValueKind(const LangOptions &Lang, - const Expr *E, - ExprValueKind Kind) { - switch (Kind) { - case VK_RValue: - return Lang.CPlusPlus ? ClassifyTemporary(E->getType()) : 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."); -} - -static Cl::Kinds ClassifyInternal(ASTContext &Ctx, const Expr *E) { - // This function takes the first stab at classifying expressions. - const LangOptions &Lang = Ctx.getLangOpts(); - - switch (E->getStmtClass()) { - 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"); - - // 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::ObjCSubscriptRefExprClass: - case Expr::ObjCPropertyRefExprClass: - // C++ [expr.typeid]p1: The result of a typeid expression is an lvalue of... - case Expr::CXXTypeidExprClass: - // Unresolved lookups and uncorrected typos get classified as lvalues. - // FIXME: Is this wise? Should they get their own kind? - case Expr::UnresolvedLookupExprClass: - case Expr::UnresolvedMemberExprClass: - case Expr::TypoExprClass: - case Expr::DependentCoawaitExprClass: - case Expr::CXXDependentScopeMemberExprClass: - case Expr::DependentScopeDeclRefExprClass: - // ObjC instance variables are lvalues - // FIXME: ObjC++0x might have different rules - case Expr::ObjCIvarRefExprClass: - case Expr::FunctionParmPackExprClass: - case Expr::MSPropertyRefExprClass: - case Expr::MSPropertySubscriptExprClass: - case Expr::OMPArraySectionExprClass: - return Cl::CL_LValue; - - // C99 6.5.2.5p5 says that compound literals are lvalues. - // In C++, they're prvalue temporaries, except for file-scope arrays. - case Expr::CompoundLiteralExprClass: - return !E->isLValue() ? ClassifyTemporary(E->getType()) : Cl::CL_LValue; - - // Expressions that are prvalues. - case Expr::CXXBoolLiteralExprClass: - case Expr::CXXPseudoDestructorExprClass: - case Expr::UnaryExprOrTypeTraitExprClass: - 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::ConvertVectorExprClass: - case Expr::IntegerLiteralClass: - case Expr::FixedPointLiteralClass: - 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::TypeTraitExprClass: - case Expr::ArrayTypeTraitExprClass: - case Expr::ExpressionTraitExprClass: - case Expr::ObjCSelectorExprClass: - case Expr::ObjCProtocolExprClass: - case Expr::ObjCStringLiteralClass: - case Expr::ObjCBoxedExprClass: - case Expr::ObjCArrayLiteralClass: - case Expr::ObjCDictionaryLiteralClass: - case Expr::ObjCBoolLiteralExprClass: - case Expr::ObjCAvailabilityCheckExprClass: - case Expr::ParenListExprClass: - case Expr::SizeOfPackExprClass: - case Expr::SubstNonTypeTemplateParmPackExprClass: - case Expr::AsTypeExprClass: - case Expr::ObjCIndirectCopyRestoreExprClass: - case Expr::AtomicExprClass: - case Expr::CXXFoldExprClass: - case Expr::ArrayInitLoopExprClass: - case Expr::ArrayInitIndexExprClass: - case Expr::NoInitExprClass: - case Expr::DesignatedInitUpdateExprClass: - return Cl::CL_PRValue; - - case Expr::ConstantExprClass: - return ClassifyInternal(Ctx, cast<ConstantExpr>(E)->getSubExpr()); - - // Next come the complicated cases. - case Expr::SubstNonTypeTemplateParmExprClass: - return ClassifyInternal(Ctx, - cast<SubstNonTypeTemplateParmExpr>(E)->getReplacement()); - - // C, C++98 [expr.sub]p1: The result is an lvalue of type "T". - // C++11 (DR1213): in the case of an array operand, the result is an lvalue - // if that operand is an lvalue and an xvalue otherwise. - // 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()); - if (Lang.CPlusPlus11) { - // Step over the array-to-pointer decay if present, but not over the - // temporary materialization. - auto *Base = cast<ArraySubscriptExpr>(E)->getBase()->IgnoreImpCasts(); - if (Base->getType()->isArrayType()) - return ClassifyInternal(Ctx, Base); - } - 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: - if (E->getType() == Ctx.UnknownAnyTy) - return isa<FunctionDecl>(cast<DeclRefExpr>(E)->getDecl()) - ? Cl::CL_PRValue : Cl::CL_LValue; - return ClassifyDecl(Ctx, cast<DeclRefExpr>(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, E->getValueKind()); - - // Pseudo-object expressions can produce l-values with reference magic. - case Expr::PseudoObjectExprClass: - return ClassifyExprValueKind(Lang, E, - cast<PseudoObjectExpr>(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, 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()); - - // C11 6.5.1.1p4: [A generic selection] is an lvalue, a function designator, - // or a void expression if its result expression is, respectively, an - // lvalue, a function designator, or a void expression. - case Expr::GenericSelectionExprClass: - if (cast<GenericSelectionExpr>(E)->isResultDependent()) - return Cl::CL_PRValue; - return ClassifyInternal(Ctx,cast<GenericSelectionExpr>(E)->getResultExpr()); - - 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::UserDefinedLiteralClass: - case Expr::CUDAKernelCallExprClass: - return ClassifyUnnamed(Ctx, cast<CallExpr>(E)->getCallReturnType(Ctx)); - - // __builtin_choose_expr is equivalent to the chosen expression. - case Expr::ChooseExprClass: - return ClassifyInternal(Ctx, cast<ChooseExpr>(E)->getChosenSubExpr()); - - // Extended vector element access is an lvalue unless there are duplicates - // in the shuffle expression. - case Expr::ExtVectorElementExprClass: - if (cast<ExtVectorElementExpr>(E)->containsDuplicateElements()) - return Cl::CL_DuplicateVectorComponents; - if (cast<ExtVectorElementExpr>(E)->isArrow()) - return Cl::CL_LValue; - return ClassifyInternal(Ctx, cast<ExtVectorElementExpr>(E)->getBase()); - - // Simply look at the actual default argument. - case Expr::CXXDefaultArgExprClass: - return ClassifyInternal(Ctx, cast<CXXDefaultArgExpr>(E)->getExpr()); - - // Same idea for default initializers. - case Expr::CXXDefaultInitExprClass: - return ClassifyInternal(Ctx, cast<CXXDefaultInitExpr>(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: - case Expr::ObjCBridgedCastExprClass: - // 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::CXXUnresolvedConstructExprClass: - return ClassifyUnnamed(Ctx, - cast<CXXUnresolvedConstructExpr>(E)->getTypeAsWritten()); - - case Expr::BinaryConditionalOperatorClass: { - if (!Lang.CPlusPlus) return Cl::CL_PRValue; - const auto *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 auto *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()) { - Cl::Kinds kind = ClassifyUnnamed(Ctx, Method->getReturnType()); - return (kind == Cl::CL_PRValue) ? Cl::CL_ObjCMessageRValue : kind; - } - return Cl::CL_PRValue; - - // Some C++ expressions are always class temporaries. - case Expr::CXXConstructExprClass: - case Expr::CXXInheritedCtorInitExprClass: - case Expr::CXXTemporaryObjectExprClass: - case Expr::LambdaExprClass: - case Expr::CXXStdInitializerListExprClass: - 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 auto *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()); - - case Expr::MaterializeTemporaryExprClass: - return cast<MaterializeTemporaryExpr>(E)->isBoundToLvalueReference() - ? Cl::CL_LValue - : Cl::CL_XValue; - - case Expr::InitListExprClass: - // An init list can be an lvalue if it is bound to a reference and - // contains only one element. In that case, we look at that element - // for an exact classification. Init list creation takes care of the - // value kind for us, so we only need to fine-tune. - if (E->isRValue()) - return ClassifyExprValueKind(Lang, E, E->getValueKind()); - assert(cast<InitListExpr>(E)->getNumInits() == 1 && - "Only 1-element init lists can be glvalues."); - return ClassifyInternal(Ctx, cast<InitListExpr>(E)->getInit(0)); - - case Expr::CoawaitExprClass: - case Expr::CoyieldExprClass: - return ClassifyInternal(Ctx, cast<CoroutineSuspendExpr>(E)->getResumeExpr()); - } - - llvm_unreachable("unhandled expression kind in classification"); -} - -/// 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 auto *NTTParm = dyn_cast<NonTypeTemplateParmDecl>(D)) - islvalue = NTTParm->getType()->isReferenceType(); - else - islvalue = isa<VarDecl>(D) || isa<FieldDecl>(D) || - isa<IndirectFieldDecl>(D) || - isa<BindingDecl>(D) || - (Ctx.getLangOpts().CPlusPlus && - (isa<FunctionDecl>(D) || isa<MSPropertyDecl>(D) || - isa<FunctionTemplateDecl>(D))); - - return islvalue ? Cl::CL_LValue : 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.getLangOpts().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 reference to object type, and a prvalue - // otherwise. - if (T->isLValueReferenceType()) - return Cl::CL_LValue; - const auto *RV = T->getAs<RValueReferenceType>(); - if (!RV) // Could still be a class temporary, though. - return ClassifyTemporary(T); - - return RV->getPointeeType()->isFunctionType() ? Cl::CL_LValue : Cl::CL_XValue; -} - -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.getLangOpts().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 (const auto *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 (const auto *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; -} - -static Cl::Kinds ClassifyBinaryOp(ASTContext &Ctx, const BinaryOperator *E) { - assert(Ctx.getLangOpts().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() || - E->hasPlaceholderType(BuiltinType::BoundMember)) - ? 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() || - E->hasPlaceholderType(BuiltinType::BoundMember)) - ? Cl::CL_MemberFunction - : Cl::CL_LValue; - - // All other binary operations are prvalues. - return Cl::CL_PRValue; -} - -static Cl::Kinds ClassifyConditional(ASTContext &Ctx, const Expr *True, - const Expr *False) { - assert(Ctx.getLangOpts().CPlusPlus && - "This is only relevant for C++."); - - // C++ [expr.cond]p2 - // If either the second or the third operand has type (cv) void, - // one of the following shall hold: - if (True->getType()->isVoidType() || False->getType()->isVoidType()) { - // The second or the third operand (but not both) is a (possibly - // parenthesized) throw-expression; the result is of the [...] value - // category of the other. - bool TrueIsThrow = isa<CXXThrowExpr>(True->IgnoreParenImpCasts()); - bool FalseIsThrow = isa<CXXThrowExpr>(False->IgnoreParenImpCasts()); - if (const Expr *NonThrow = TrueIsThrow ? (FalseIsThrow ? nullptr : False) - : (FalseIsThrow ? True : nullptr)) - return ClassifyInternal(Ctx, NonThrow); - - // [Otherwise] the result [...] is a prvalue. - 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; -} - -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 auto *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.getLangOpts().CPlusPlus && E->getType()->isFunctionType()) - return Cl::CM_Function; - - // Assignment to a property in ObjC is an implicit setter access. But a - // setter might not exist. - if (const auto *Expr = dyn_cast<ObjCPropertyRefExpr>(E)) { - if (Expr->isImplicitProperty() && - Expr->getImplicitPropertySetter() == nullptr) - return Cl::CM_NoSetterProperty; - } - - CanQualType CT = Ctx.getCanonicalType(E->getType()); - // Const stuff is obviously not modifiable. - if (CT.isConstQualified()) - return Cl::CM_ConstQualified; - if (Ctx.getLangOpts().OpenCL && - CT.getQualifiers().getAddressSpace() == LangAS::opencl_constant) - return Cl::CM_ConstAddrSpace; - - // 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>()) - if (R->hasConstFields()) - return Cl::CM_ConstQualifiedField; - - return Cl::CM_Modifiable; -} - -Expr::LValueClassification Expr::ClassifyLValue(ASTContext &Ctx) const { - Classification VC = Classify(Ctx); - switch (VC.getKind()) { - case Cl::CL_LValue: return LV_Valid; - case Cl::CL_XValue: return LV_InvalidExpression; - case Cl::CL_Function: return LV_NotObjectType; - case Cl::CL_Void: return LV_InvalidExpression; - case Cl::CL_AddressableVoid: return LV_IncompleteVoidType; - case Cl::CL_DuplicateVectorComponents: return LV_DuplicateVectorComponents; - case Cl::CL_MemberFunction: return LV_MemberFunction; - case Cl::CL_SubObjCPropertySetting: return LV_SubObjCPropertySetting; - case Cl::CL_ClassTemporary: return LV_ClassTemporary; - case Cl::CL_ArrayTemporary: return LV_ArrayTemporary; - case Cl::CL_ObjCMessageRValue: return LV_InvalidMessageExpression; - case Cl::CL_PRValue: return LV_InvalidExpression; - } - llvm_unreachable("Unhandled kind"); -} - -Expr::isModifiableLvalueResult -Expr::isModifiableLvalue(ASTContext &Ctx, SourceLocation *Loc) const { - SourceLocation dummy; - Classification VC = ClassifyModifiable(Ctx, Loc ? *Loc : dummy); - switch (VC.getKind()) { - case Cl::CL_LValue: break; - case Cl::CL_XValue: return MLV_InvalidExpression; - case Cl::CL_Function: return MLV_NotObjectType; - case Cl::CL_Void: return MLV_InvalidExpression; - case Cl::CL_AddressableVoid: return MLV_IncompleteVoidType; - case Cl::CL_DuplicateVectorComponents: return MLV_DuplicateVectorComponents; - case Cl::CL_MemberFunction: return MLV_MemberFunction; - case Cl::CL_SubObjCPropertySetting: return MLV_SubObjCPropertySetting; - case Cl::CL_ClassTemporary: return MLV_ClassTemporary; - case Cl::CL_ArrayTemporary: return MLV_ArrayTemporary; - case Cl::CL_ObjCMessageRValue: return MLV_InvalidMessageExpression; - case Cl::CL_PRValue: - return VC.getModifiable() == Cl::CM_LValueCast ? - MLV_LValueCast : MLV_InvalidExpression; - } - assert(VC.getKind() == Cl::CL_LValue && "Unhandled kind"); - switch (VC.getModifiable()) { - case Cl::CM_Untested: llvm_unreachable("Did not test modifiability"); - case Cl::CM_Modifiable: return MLV_Valid; - case Cl::CM_RValue: llvm_unreachable("CM_RValue and CL_LValue don't match"); - case Cl::CM_Function: return MLV_NotObjectType; - case Cl::CM_LValueCast: - llvm_unreachable("CM_LValueCast and CL_LValue don't match"); - case Cl::CM_NoSetterProperty: return MLV_NoSetterProperty; - case Cl::CM_ConstQualified: return MLV_ConstQualified; - case Cl::CM_ConstQualifiedField: return MLV_ConstQualifiedField; - case Cl::CM_ConstAddrSpace: return MLV_ConstAddrSpace; - case Cl::CM_ArrayType: return MLV_ArrayType; - case Cl::CM_IncompleteType: return MLV_IncompleteType; - } - llvm_unreachable("Unhandled modifiable type"); -} |