diff options
author | Richard Smith <richard-llvm@metafoo.co.uk> | 2012-02-18 22:04:06 +0000 |
---|---|---|
committer | Richard Smith <richard-llvm@metafoo.co.uk> | 2012-02-18 22:04:06 +0000 |
commit | 86024013d4c3728122c58fa07a2a67e6c15837ef (patch) | |
tree | 1d9ee12ad5d09f5c35f44f6fe06d876dd8c5ffc9 /lib/AST/ExprConstant.cpp | |
parent | e215ba1c2a3f29fe2cbc4cfb0e532cd204970c49 (diff) |
Implement constant expression support for __real__ and __imag__ on lvalue
complex numbers. Treat complex numbers as arrays of the corresponding component
type, in order to make std::complex behave properly if implemented in terms of
_Complex T.
Apparently libstdc++'s std::complex is implemented this way, and we were
rejecting a member like this:
constexpr double real() { return __real__ val; }
because it was marked constexpr but unable to produce a constant expression.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@150895 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/AST/ExprConstant.cpp')
-rw-r--r-- | lib/AST/ExprConstant.cpp | 91 |
1 files changed, 85 insertions, 6 deletions
diff --git a/lib/AST/ExprConstant.cpp b/lib/AST/ExprConstant.cpp index fcba037afc..dda6e84922 100644 --- a/lib/AST/ExprConstant.cpp +++ b/lib/AST/ExprConstant.cpp @@ -105,6 +105,11 @@ namespace { Type = CAT->getElementType(); ArraySize = CAT->getSize().getZExtValue(); MostDerivedLength = I + 1; + } else if (Type->isAnyComplexType()) { + const ComplexType *CT = Type->castAs<ComplexType>(); + Type = CT->getElementType(); + ArraySize = 2; + MostDerivedLength = I + 1; } else if (const FieldDecl *FD = getAsField(Path[I])) { Type = FD->getType(); ArraySize = 0; @@ -120,7 +125,7 @@ namespace { // The order of this enum is important for diagnostics. enum CheckSubobjectKind { CSK_Base, CSK_Derived, CSK_Field, CSK_ArrayToPointer, CSK_ArrayIndex, - CSK_This + CSK_This, CSK_Real, CSK_Imag }; /// A path from a glvalue to a subobject of that glvalue. @@ -221,6 +226,18 @@ namespace { MostDerivedPathLength = Entries.size(); } } + /// Update this designator to refer to the given complex component. + void addComplexUnchecked(QualType EltTy, bool Imag) { + PathEntry Entry; + Entry.ArrayIndex = Imag; + Entries.push_back(Entry); + + // This is technically a most-derived object, though in practice this + // is unlikely to matter. + MostDerivedType = EltTy; + MostDerivedArraySize = 2; + MostDerivedPathLength = Entries.size(); + } void diagnosePointerArithmetic(EvalInfo &Info, const Expr *E, uint64_t N); /// Add N to the address of this subobject. void adjustIndex(EvalInfo &Info, const Expr *E, uint64_t N) { @@ -792,6 +809,10 @@ namespace { checkSubobject(Info, E, CSK_ArrayToPointer); Designator.addArrayUnchecked(CAT); } + void addComplex(EvalInfo &Info, const Expr *E, QualType EltTy, bool Imag) { + checkSubobject(Info, E, Imag ? CSK_Imag : CSK_Real); + Designator.addComplexUnchecked(EltTy, Imag); + } void adjustIndex(EvalInfo &Info, const Expr *E, uint64_t N) { if (!checkNullPointer(Info, E, CSK_ArrayIndex)) return; @@ -1420,6 +1441,24 @@ static bool HandleLValueArrayAdjustment(EvalInfo &Info, const Expr *E, return true; } +/// Update an lvalue to refer to a component of a complex number. +/// \param Info - Information about the ongoing evaluation. +/// \param LVal - The lvalue to be updated. +/// \param EltTy - The complex number's component type. +/// \param Imag - False for the real component, true for the imaginary. +static bool HandleLValueComplexElement(EvalInfo &Info, const Expr *E, + LValue &LVal, QualType EltTy, + bool Imag) { + if (Imag) { + CharUnits SizeOfComponent; + if (!HandleSizeof(Info, E->getExprLoc(), EltTy, SizeOfComponent)) + return false; + LVal.Offset += SizeOfComponent; + } + LVal.addComplex(Info, E, EltTy, Imag); + return true; +} + /// Try to evaluate the initializer for a variable declaration. static bool EvaluateVarDeclInit(EvalInfo &Info, const Expr *E, const VarDecl *VD, @@ -1566,6 +1605,25 @@ static bool ExtractSubobject(EvalInfo &Info, const Expr *E, else O = &O->getArrayFiller(); ObjType = CAT->getElementType(); + } else if (ObjType->isAnyComplexType()) { + // Next subobject is a complex number. + uint64_t Index = Sub.Entries[I].ArrayIndex; + if (Index > 1) { + Info.Diag(E->getExprLoc(), Info.getLangOpts().CPlusPlus0x ? + (unsigned)diag::note_constexpr_read_past_end : + (unsigned)diag::note_invalid_subexpr_in_const_expr); + return false; + } + assert(I == N - 1 && "extracting subobject of scalar?"); + if (O->isComplexInt()) { + Obj = CCValue(Index ? O->getComplexIntImag() + : O->getComplexIntReal()); + } else { + assert(O->isComplexFloat()); + Obj = CCValue(Index ? O->getComplexFloatImag() + : O->getComplexFloatReal()); + } + return true; } else if (const FieldDecl *Field = getAsField(Sub.Entries[I])) { if (Field->isMutable()) { Info.Diag(E->getExprLoc(), diag::note_constexpr_ltor_mutable, 1) @@ -1628,13 +1686,17 @@ static unsigned FindDesignatorMismatch(QualType ObjType, bool &WasArrayIndex) { unsigned I = 0, N = std::min(A.Entries.size(), B.Entries.size()); for (/**/; I != N; ++I) { - if (!ObjType.isNull() && ObjType->isArrayType()) { + if (!ObjType.isNull() && + (ObjType->isArrayType() || ObjType->isAnyComplexType())) { // Next subobject is an array element. if (A.Entries[I].ArrayIndex != B.Entries[I].ArrayIndex) { WasArrayIndex = true; return I; } - ObjType = ObjType->castAsArrayTypeUnsafe()->getElementType(); + if (ObjType->isAnyComplexType()) + ObjType = ObjType->castAs<ComplexType>()->getElementType(); + else + ObjType = ObjType->castAsArrayTypeUnsafe()->getElementType(); } else { if (A.Entries[I].BaseOrMember != B.Entries[I].BaseOrMember) { WasArrayIndex = false; @@ -2870,6 +2932,8 @@ public: bool VisitCXXTypeidExpr(const CXXTypeidExpr *E); bool VisitArraySubscriptExpr(const ArraySubscriptExpr *E); bool VisitUnaryDeref(const UnaryOperator *E); + bool VisitUnaryReal(const UnaryOperator *E); + bool VisitUnaryImag(const UnaryOperator *E); bool VisitCastExpr(const CastExpr *E) { switch (E->getCastKind()) { @@ -2889,9 +2953,6 @@ public: return HandleBaseToDerivedCast(Info, E, Result); } } - - // FIXME: Missing: __real__, __imag__ - }; } // end anonymous namespace @@ -3015,6 +3076,24 @@ bool LValueExprEvaluator::VisitUnaryDeref(const UnaryOperator *E) { return EvaluatePointer(E->getSubExpr(), Result, Info); } +bool LValueExprEvaluator::VisitUnaryReal(const UnaryOperator *E) { + if (!Visit(E->getSubExpr())) + return false; + // __real is a no-op on scalar lvalues. + if (E->getSubExpr()->getType()->isAnyComplexType()) + HandleLValueComplexElement(Info, E, Result, E->getType(), false); + return true; +} + +bool LValueExprEvaluator::VisitUnaryImag(const UnaryOperator *E) { + assert(E->getSubExpr()->getType()->isAnyComplexType() && + "lvalue __imag__ on scalar?"); + if (!Visit(E->getSubExpr())) + return false; + HandleLValueComplexElement(Info, E, Result, E->getType(), true); + return true; +} + //===----------------------------------------------------------------------===// // Pointer Evaluation //===----------------------------------------------------------------------===// |