On Mon, October 24, 2011 22:52, David Dean wrote: > My bots are hitting an assert after this change:
Thanks for letting me know. Reverted in r142872. I've reproduced this. The root cause looks to be that we're missing an lvalue-to-rvalue conversion for the LHS of '->' in some cases. > Assertion failed: (E->isRValue() && > E->getType()->hasPointerRepresentation()), function EvaluatePointer, file > /Users/buildslave/zorg/buildbot/smooshlab/slave-0.8/build.clang-x86_64-darwin > 10-gcc42-RA/llvm/tools/clang/lib/AST/ExprConstant.cpp, line 778. > 0 clang 0x0000000101af0eb2 > llvm::SmallVectorTemplateBase<llvm_regmatch_t, false>::grow(unsigned long) + > 338 > 1 clang 0x0000000101af1e33 > llvm::SmallVectorTemplateBase<llvm_regmatch_t, false>::grow(unsigned long) + > 4307 > 2 libSystem.B.dylib 0x00007fff8573b67a _sigtramp + 26 > 3 libSystem.B.dylib 0x0000000000000004 _sigtramp + 2056014244 > 4 clang 0x0000000101af1332 > llvm::SmallVectorTemplateBase<llvm_regmatch_t, false>::grow(unsigned long) + > 1490 > 5 clang 0x0000000100bbd9a2 > clang::Expr::Classification::getModifiable() const + 85250 > 6 clang 0x0000000100bbf4e3 > clang::Expr::Classification::getModifiable() const + 92227 > 7 clang 0x0000000100baffea > clang::Expr::Classification::getModifiable() const + 29514 > 8 clang 0x0000000100bbe6b4 > clang::Expr::Classification::getModifiable() const + 88596 > 9 clang 0x0000000100bbcd2f > clang::Expr::Classification::getModifiable() const + 82063 > 10 clang 0x0000000100bbd9e6 > clang::Expr::Classification::getModifiable() const + 85318 > 11 clang 0x0000000100bbfe25 > clang::Expr::Classification::getModifiable() const + 94597 > 12 clang 0x0000000100baca0d > clang::Expr::Classification::getModifiable() const + 15725 > 13 clang 0x0000000100bb4121 > clang::Expr::Classification::getModifiable() const + 46209 > 14 clang 0x0000000100bb5fc0 > clang::Expr::Classification::getModifiable() const + 54048 > 15 clang 0x0000000100bb6415 > clang::Expr::Classification::getModifiable() const + 55157 > 16 clang 0x00000001008dbf82 llvm::DenseMap<clang::Stmt const*, > clang::CFGBlock const*, llvm::DenseMapInfo<clang::Stmt const*>, > llvm::DenseMapInfo<clang::CFGBlock const*> >::grow(unsigned int) + 87314 > 17 clang 0x00000001008d5b4d llvm::DenseMap<clang::Stmt const*, > clang::CFGBlock const*, llvm::DenseMapInfo<clang::Stmt const*>, > llvm::DenseMapInfo<clang::CFGBlock const*> >::grow(unsigned int) + 61661 > 18 clang 0x00000001008d842c llvm::DenseMap<clang::Stmt const*, > clang::CFGBlock const*, llvm::DenseMapInfo<clang::Stmt const*>, > llvm::DenseMapInfo<clang::CFGBlock const*> >::grow(unsigned int) + 72124 > 19 clang 0x00000001008d5e1f llvm::DenseMap<clang::Stmt const*, > clang::CFGBlock const*, llvm::DenseMapInfo<clang::Stmt const*>, > llvm::DenseMapInfo<clang::CFGBlock const*> >::grow(unsigned int) + 62383 > 20 clang 0x00000001008d58ee llvm::DenseMap<clang::Stmt const*, > clang::CFGBlock const*, llvm::DenseMapInfo<clang::Stmt const*>, > llvm::DenseMapInfo<clang::CFGBlock const*> >::grow(unsigned int) + 61054 > 21 clang 0x00000001008dc099 llvm::DenseMap<clang::Stmt const*, > clang::CFGBlock const*, llvm::DenseMapInfo<clang::Stmt const*>, > llvm::DenseMapInfo<clang::CFGBlock const*> >::grow(unsigned int) + 87593 > 22 clang 0x00000001008dce30 llvm::DenseMap<clang::Stmt const*, > clang::CFGBlock const*, llvm::DenseMapInfo<clang::Stmt const*>, > llvm::DenseMapInfo<clang::CFGBlock const*> >::grow(unsigned int) + 91072 > 23 clang 0x00000001008c0be9 llvm::DenseMap<clang::ento::SymbolData > const*, clang::ento::SymbolReaper::SymbolStatus, > llvm::DenseMapInfo<clang::ento::SymbolData const*>, > llvm::DenseMapInfo<clang::ento::SymbolReaper::SymbolStatus> >::grow(unsigned > int) + 3033 24 clang 0x00000001003b0016 > clang::Parser::ConsumeAnyToken() + 22310 > 25 clang 0x00000001003d86e8 clang::Expr** > llvm::PointerUnion<clang::Expr*, clang::Expr**>::get<clang::Expr**>() const + > 38152 > 26 clang 0x0000000100479e2d > clang::CanQual<clang::ReferenceType>::CreateUnsafe(clang::QualType) + 127789 > 27 clang 0x0000000100732b4b > llvm::cast_retty<clang::TemplateSpecializationType, > clang::CanQual<clang::Type> >::ret_type > llvm::cast<clang::TemplateSpecializationType, clang::CanQual<clang::Type> > >(clang::CanQual<clang::Type> const&) + 54219 > 28 clang 0x0000000100733657 > llvm::cast_retty<clang::TemplateSpecializationType, > clang::CanQual<clang::Type> >::ret_type > llvm::cast<clang::TemplateSpecializationType, clang::CanQual<clang::Type> > >(clang::CanQual<clang::Type> const&) + 57047 > 29 clang 0x0000000100733105 > llvm::cast_retty<clang::TemplateSpecializationType, > clang::CanQual<clang::Type> >::ret_type > llvm::cast<clang::TemplateSpecializationType, clang::CanQual<clang::Type> > >(clang::CanQual<clang::Type> const&) + 55685 > 30 clang 0x0000000100733657 > llvm::cast_retty<clang::TemplateSpecializationType, > clang::CanQual<clang::Type> >::ret_type > llvm::cast<clang::TemplateSpecializationType, clang::CanQual<clang::Type> > >(clang::CanQual<clang::Type> const&) + 57047 > 31 clang 0x0000000100733105 > llvm::cast_retty<clang::TemplateSpecializationType, > clang::CanQual<clang::Type> >::ret_type > llvm::cast<clang::TemplateSpecializationType, clang::CanQual<clang::Type> > >(clang::CanQual<clang::Type> const&) + 55685 > 32 clang 0x0000000100733657 > llvm::cast_retty<clang::TemplateSpecializationType, > clang::CanQual<clang::Type> >::ret_type > llvm::cast<clang::TemplateSpecializationType, clang::CanQual<clang::Type> > >(clang::CanQual<clang::Type> const&) + 57047 > 33 clang 0x00000001003d890d clang::Expr** > llvm::PointerUnion<clang::Expr*, clang::Expr**>::get<clang::Expr**>() const + > 38701 > 34 clang 0x00000001003a8baf > llvm::SmallVectorTemplateBase<clang::ParsedTemplateArgument, > false>::grow(unsigned long) + 71839 > 35 clang 0x000000010032518b llvm::IRBuilder<true, > llvm::ConstantFolder, llvm::IRBuilderDefaultInserter<true> > >::CreateGEP(llvm::Value*, llvm::Value*, llvm::Twine const&) + 859 > 36 clang 0x00000001002ee24c llvm::ValueMapCallbackVH<llvm::Value > const*, llvm::TrackingVH<llvm::Value>, llvm::ValueMapConfig<llvm::Value > const*>, llvm::DenseMapInfo<llvm::TrackingVH<llvm::Value> > > >::allUsesReplacedWith(llvm::Value*) + 4156 > 37 clang 0x0000000100030853 llvm::DenseMap<clang::IdentifierInfo > const*, unsigned int, llvm::DenseMapInfo<clang::IdentifierInfo const*>, > llvm::DenseMapInfo<unsigned int> >::grow(unsigned int) + 25475 > 38 clang 0x000000010000b645 llvm::raw_ostream::operator<<(char > const*) + 1893 39 clang 0x0000000100002358 > 40 clang 0x000000010000a38e std::vector<std::string, > std::allocator<std::string> >::operator=(std::vector<std::string, > std::allocator<std::string> > const&) + 13774 > 41 clang 0x0000000100000c34 > Stack dump: > 0. Program arguments: > /Users/buildslave/zorg/buildbot/smooshlab/slave-0.8/build.clang-x86_64-darwin > 10-RA/host-compiler/bin/clang -cc1 -triple x86_64-apple-macosx10.6.6 > -emit-obj -disable-free -main-file-name CommandLine.cpp -pic-level 1 > -mdisable-fp-elim -masm-verbose -munwind-tables -target-cpu core2 > -target-linker-version 123.4 -coverage-file > /Users/buildslave/zorg/buildbot/smooshlab/slave-0.8/build.clang-x86_64-darwin > 10-RA/clang-build/lib/Support/Release+Asserts/CommandLine.o -resource-dir > /Users/buildslave/zorg/buildbot/smooshlab/slave-0.8/build.clang-x86_64-darwin > 10-RA/host-compiler/bin/../lib/clang/3.1 -dependency-file > /Users/buildslave/zorg/buildbot/smooshlab/slave-0.8/build.clang-x86_64-darwin > 10-RA/clang-build/lib/Support/Release+Asserts/CommandLine.d.tmp -MP -MT > /Users/buildslave/zorg/buildbot/smooshlab/slave-0.8/build.clang-x86_64-darwin > 10-RA/clang-build/lib/Support/Release+Asserts/CommandLine.o -MT > /Users/buildslave/zorg/buildbot/smooshlab/slave-0.8/build.clang-x86_64-darwin > 10-RA/clang-build/lib/Support/Release+Asserts/CommandLine.d -D _DEBUG -D > _GNU_SOURCE -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D > __STDC_LIMIT_MACROS -I > /Users/buildslave/zorg/buildbot/smooshlab/slave-0.8/build.clang-x86_64-darwin > 10-RA/clang-build/include -I > /Users/buildslave/zorg/buildbot/smooshlab/slave-0.8/build.clang-x86_64-darwin > 10-RA/clang-build/lib/Support -I > /Users/buildslave/zorg/buildbot/smooshlab/slave-0.8/build.clang-x86_64-darwin > 10-RA/llvm/include -I > /Users/buildslave/zorg/buildbot/smooshlab/slave-0.8/build.clang-x86_64-darwin > 10-RA/llvm/lib/Support -fmodule-cache-path > /var/folders/K2/K2x7HyV8GZSimPbqHtjYKE+++TQ/-Tmp-/clang-module-cache -O3 > -Woverloaded-virtual -Wcast-qual -Wall -W -Wno-unused-parameter > -Wwrite-strings -fconst-strings -fdeprecated-macro -fdebug-compilation-dir > /Users/buildslave/zorg/buildbot/smooshlab/slave-0.8/build.clang-x86_64-darwin > 10-RA/clang-build/lib/Support -ferror-limit 19 -fmessage-length 0 > -stack-protector 1 -fblocks -fobjc-dispatch-method=mixed -fno-common > -fdiagnostics-show-option -o > /Users/buildslave/zorg/buildbot/smooshlab/slave-0.8/build.clang-x86_64-darwin > 10-RA/clang-build/lib/Support/Release+Asserts/CommandLine.o -x c++ > /Users/buildslave/zorg/buildbot/smooshlab/slave-0.8/build.clang-x86_64-darwin > 10-RA/llvm/lib/Support/CommandLine.cpp > 1. <eof> parser at end of file > 2. > /Users/buildslave/zorg/buildbot/smooshlab/slave-0.8/build.clang-x86_64-darwin > 10-RA/llvm/include/llvm/ADT/StringMap.h:295:18: instantiating function > definition 'find' 3. > /Users/buildslave/zorg/buildbot/smooshlab/slave-0.8/build.clang-x86_64-darwin > 10-RA/llvm/include/llvm/ADT/StringMap.h:417:12: instantiating function > definition 'StringMapConstIterator' 4. > /Users/buildslave/zorg/buildbot/smooshlab/slave-0.8/build.clang-x86_64-darwin > 10-RA/llvm/include/llvm/ADT/StringMap.h:447:8: instantiating function > definition 'AdvancePastEmptyBuckets' clang: error: unable to execute command: > Illegal instruction > clang: error: clang frontend command failed due to signal 2 (use -v to see > invocation) clang: note: diagnostic msg: Please submit a bug report to > http://llvm.org/bugs/ and include command line arguments and all diagnostic > information. > > llvm[1]: Compiling CrashRecoveryContext.cpp for Release+Asserts build > > > > > On 24 Oct 2011, at 2:07 PM, Richard Smith wrote: > > >> Author: rsmith >> Date: Mon Oct 24 16:07:08 2011 >> New Revision: 142844 >> >> >> URL: http://llvm.org/viewvc/llvm-project?rev=142844&view=rev >> Log: >> Constant expression evaluation: evaluate lvalues as lvalues, and rvalues as >> rvalues, as C++11 constant evaluation semantics require. DeclRefs referring >> to references can now use the normal initialization-caching codepath, which >> incidentally fixes a crash in cyclic initialization of references. >> >> Modified: >> cfe/trunk/include/clang/AST/Expr.h cfe/trunk/lib/AST/ExprConstant.cpp >> cfe/trunk/test/SemaCXX/i-c-e-cxx.cpp >> >> Modified: cfe/trunk/include/clang/AST/Expr.h >> URL: >> http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/AST/Expr.h?rev= >> 142844&r1=142843&r2=142844&view=diff >> ============================================================================ >> == >> --- cfe/trunk/include/clang/AST/Expr.h (original) >> +++ cfe/trunk/include/clang/AST/Expr.h Mon Oct 24 16:07:08 2011 >> @@ -465,7 +465,8 @@ >> /// Evaluate - Return true if this is a constant which we can fold using >> /// any crazy technique (that has nothing to do with language standards) >> that /// we want to. If this function returns true, it returns the folded >> constant - /// in Result. >> + /// in Result. If this expression is a glvalue, an lvalue-to-rvalue >> conversion + /// will be applied. >> bool Evaluate(EvalResult &Result, const ASTContext &Ctx) const; >> >> /// EvaluateAsBooleanCondition - Return true if this is a constant >> >> >> Modified: cfe/trunk/lib/AST/ExprConstant.cpp >> URL: >> http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/AST/ExprConstant.cpp?rev= >> 142844&r1=142843&r2=142844&view=diff >> ============================================================================ >> == >> --- cfe/trunk/lib/AST/ExprConstant.cpp (original) >> +++ cfe/trunk/lib/AST/ExprConstant.cpp Mon Oct 24 16:07:08 2011 >> @@ -151,7 +151,7 @@ >> return true; } >> >> >> -static bool EvalPointerValueAsBool(LValue& Value, bool& Result) { >> +static bool EvalPointerValueAsBool(const LValue &Value, bool &Result) { >> const Expr* Base = Value.Base; >> >> // A null base expression indicates a null pointer. These are always >> @@ -183,40 +183,44 @@ >> return true; } >> >> >> -static bool HandleConversionToBool(const Expr* E, bool& Result, >> - EvalInfo &Info) { >> - if (E->getType()->isIntegralOrEnumerationType()) { >> - APSInt IntResult; >> - if (!EvaluateInteger(E, IntResult, Info)) >> - return false; >> - Result = IntResult != 0; >> +static bool HandleConversionToBool(const APValue &Val, bool &Result) { >> + switch (Val.getKind()) { >> + case APValue::Uninitialized: >> + return false; >> + case APValue::Int: >> + Result = Val.getInt().getBoolValue(); >> return true; - } else if (E->getType()->isRealFloatingType()) { >> - APFloat FloatResult(0.0); >> - if (!EvaluateFloat(E, FloatResult, Info)) >> - return false; >> - Result = !FloatResult.isZero(); >> + case APValue::Float: >> + Result = !Val.getFloat().isZero(); >> return true; - } else if (E->getType()->hasPointerRepresentation()) { >> - LValue PointerResult; >> - if (!EvaluatePointer(E, PointerResult, Info)) >> - return false; >> - return EvalPointerValueAsBool(PointerResult, Result); >> - } else if (E->getType()->isAnyComplexType()) { >> - ComplexValue ComplexResult; >> - if (!EvaluateComplex(E, ComplexResult, Info)) >> - return false; >> - if (ComplexResult.isComplexFloat()) { >> - Result = !ComplexResult.getComplexFloatReal().isZero() || >> - !ComplexResult.getComplexFloatImag().isZero(); >> - } else { >> - Result = ComplexResult.getComplexIntReal().getBoolValue() || >> - ComplexResult.getComplexIntImag().getBoolValue(); >> - } >> + case APValue::ComplexInt: >> + Result = Val.getComplexIntReal().getBoolValue() || >> + Val.getComplexIntImag().getBoolValue(); >> return true; + case APValue::ComplexFloat: >> + Result = !Val.getComplexFloatReal().isZero() || >> + !Val.getComplexFloatImag().isZero(); >> + return true; >> + case APValue::LValue: >> + { >> + LValue PointerResult; >> + PointerResult.setFrom(Val); >> + return EvalPointerValueAsBool(PointerResult, Result); >> + } >> + case APValue::Vector: >> + return false; >> } >> >> >> - return false; >> + llvm_unreachable("unknown APValue kind"); >> +} >> + >> +static bool EvaluateAsBooleanCondition(const Expr *E, bool &Result, >> + EvalInfo &Info) { >> + assert(E->isRValue() && "missing lvalue-to-rvalue conv in bool >> condition"); + APValue Val; >> + if (!Evaluate(Val, Info, E)) >> + return false; >> + return HandleConversionToBool(Val, Result); >> } >> >> >> static APSInt HandleFloatToIntCast(QualType DestType, QualType SrcType, @@ >> -278,10 +282,11 @@ >> >> >> VD->setEvaluatingValue(); >> >> >> - // FIXME: If the initializer isn't a constant expression, propagate up >> any - // diagnostic explaining why not. >> Expr::EvalResult EResult; >> - if (Init->Evaluate(EResult, Info.Ctx) && !EResult.HasSideEffects) >> + EvalInfo InitInfo(Info.Ctx, EResult); >> + // FIXME: The caller will need to know whether the value was a constant >> + // expression. If not, we should propagate up a diagnostic. >> + if (Evaluate(EResult.Val, InitInfo, Init)) >> VD->setEvaluatedValue(EResult.Val); >> else VD->setEvaluatedValue(APValue()); >> @@ -294,6 +299,52 @@ >> return Quals.hasConst() && !Quals.hasVolatile(); } >> >> >> +bool HandleLValueToRValueConversion(EvalInfo &Info, QualType Type, >> + const LValue &LValue, APValue &RValue) >> { >> + const Expr *Base = LValue.Base; >> + >> + // FIXME: Indirection through a null pointer deserves a diagnostic. >> + if (!Base) >> + return false; >> + >> + // FIXME: Support accessing subobjects of objects of literal types. A >> simple + // byte offset is insufficient for C++11 semantics: we need to >> know how the + // reference was formed (which union member was named, for >> instance). + // FIXME: Support subobjects of StringLiteral and >> PredefinedExpr. >> + if (!LValue.Offset.isZero()) >> + return false; >> + >> + if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(Base)) { >> + // In C++, const, non-volatile integers initialized with ICEs are ICEs. >> + // In C, they can also be folded, although they are not ICEs. >> + // In C++0x, constexpr variables are constant expressions too. >> + // We allow folding any const variable of literal type initialized with >> + // a constant expression. >> + const VarDecl *VD = dyn_cast<VarDecl>(DRE->getDecl()); >> + if (VD && IsConstNonVolatile(VD->getType()) && Type->isLiteralType()) { >> + APValue *V = EvaluateVarDeclInit(Info, VD); >> + if (V && !V->isUninit()) { >> + RValue = *V; >> + return true; >> + } >> + } >> + return false; >> + } >> + >> + // FIXME: C++11: Support MaterializeTemporaryExpr in LValueExprEvaluator >> and + // here. >> + >> + // In C99, a CompoundLiteralExpr is an lvalue, and we defer evaluating >> the + // initializer until now for such expressions. Such an expression >> can't be + // an ICE in C, so this only matters for fold. >> + if (const CompoundLiteralExpr *CLE = dyn_cast<CompoundLiteralExpr>(Base)) >> { >> + assert(!Info.getLangOpts().CPlusPlus && "lvalue compound literal in >> c++?"); + return Evaluate(RValue, Info, CLE->getInitializer()); >> + } >> + >> + return false; >> +} >> + >> namespace { class HasSideEffect : public ConstStmtVisitor<HasSideEffect, >> bool> >> { >> @@ -454,7 +505,7 @@ >> return DerivedError(E); >> >> bool cond; - if (!HandleConversionToBool(E->getCond(), cond, Info)) >> + if (!EvaluateAsBooleanCondition(E->getCond(), cond, Info)) >> return DerivedError(E); >> >> return StmtVisitorTy::Visit(cond ? E->getTrueExpr() : E->getFalseExpr()); @@ >> -462,10 +513,10 @@ >> >> >> RetTy VisitConditionalOperator(const ConditionalOperator *E) { >> bool BoolResult; - if (!HandleConversionToBool(E->getCond(), BoolResult, >> Info)) >> + if (!EvaluateAsBooleanCondition(E->getCond(), BoolResult, Info)) >> return DerivedError(E); >> >> - Expr* EvalExpr = BoolResult ? E->getTrueExpr() : E->getFalseExpr(); >> + Expr *EvalExpr = BoolResult ? E->getTrueExpr() : E->getFalseExpr(); >> return StmtVisitorTy::Visit(EvalExpr); } >> >> >> @@ -477,6 +528,9 @@ >> return DerivedSuccess(*value, E); } >> >> >> + RetTy VisitCompoundLiteralExpr(const CompoundLiteralExpr *E) { >> + return StmtVisitorTy::Visit(E->getInitializer()); >> + } >> RetTy VisitInitListExpr(const InitListExpr *E) { >> if (Info.getLangOpts().CPlusPlus0x) { if (E->getNumInits() == 0) @@ -493,6 >> +547,28 @@ >> return DerivedValueInitialization(E); } >> >> >> + RetTy VisitCastExpr(const CastExpr *E) { >> + switch (E->getCastKind()) { >> + default: >> + break; >> + >> + case CK_NoOp: >> + return StmtVisitorTy::Visit(E->getSubExpr()); >> + >> + case CK_LValueToRValue: { >> + LValue LVal; >> + if (EvaluateLValue(E->getSubExpr(), LVal, Info)) { >> + APValue RVal; >> + if (HandleLValueToRValueConversion(Info, E->getType(), LVal, RVal)) >> + return DerivedSuccess(RVal, E); >> + } >> + break; >> + } >> + } >> + >> + return DerivedError(E); >> + } >> + >> /// Visit a value which is evaluated, but whose value is ignored. >> void VisitIgnoredValue(const Expr *E) { APValue Scratch; >> @@ -505,6 +581,10 @@ >> >> >> //===---------------------------------------------------------------------- >> ===// >> // LValue Evaluation >> +// >> +// This is used for evaluating lvalues (in C and C++), xvalues (in C++11), >> +// function designators (in C), decl references to void objects (in C), and >> +// temporaries (if building with -Wno-address-of-temporary). >> //===----------------------------------------------------------------------= >> ==// >> namespace { class LValueExprEvaluator @@ -542,13 +622,13 @@ >> bool VisitCastExpr(const CastExpr *E) { switch (E->getCastKind()) { default: >> - return false; >> + return ExprEvaluatorBaseTy::VisitCastExpr(E); >> >> >> - case CK_NoOp: >> case CK_LValueBitCast: return Visit(E->getSubExpr()); >> >> - // FIXME: Support CK_DerivedToBase and friends. >> + // FIXME: Support CK_DerivedToBase and CK_UncheckedDerivedToBase. >> + // Reuse PointerExprEvaluator::VisitCastExpr for these. >> } >> } >> >> >> @@ -557,6 +637,11 @@ >> }; >> } // end anonymous namespace >> >> >> +/// Evaluate an expression as an lvalue. This can be legitimately called >> on +/// expressions which are not glvalues, in a few cases: >> +/// * function designators in C, >> +/// * "extern void" objects, >> +/// * temporaries, if building with -Wno-address-of-temporary. >> static bool EvaluateLValue(const Expr* E, LValue& Result, EvalInfo &Info) { >> return LValueExprEvaluator(Info, Result).Visit(E); } >> @@ -570,22 +655,24 @@ >> // Reference parameters can refer to anything even if they have an >> // "initializer" in the form of a default argument. >> if (!isa<ParmVarDecl>(VD)) { - // FIXME: Check whether VD might be >> overridden! - >> - // Check for recursive initializers of references. >> - if (PrevDecl == VD) >> - return Error(E); >> - PrevDecl = VD; >> - if (const Expr *Init = VD->getAnyInitializer()) >> - return Visit(Init); >> + APValue *V = EvaluateVarDeclInit(Info, VD); >> + if (V && !V->isUninit()) { >> + assert(V->isLValue() && "reference init not glvalue"); >> + Result.Base = V->getLValueBase(); >> + Result.Offset = V->getLValueOffset(); >> + return true; >> + } >> } >> } >> >> >> - return ExprEvaluatorBaseTy::VisitDeclRefExpr(E); >> + return Error(E); >> } >> >> >> bool LValueExprEvaluator::VisitCompoundLiteralExpr(const CompoundLiteralExpr >> *E) { >> + assert(!Info.getLangOpts().CPlusPlus && "lvalue compound literal in >> c++?"); + // Defer visiting the literal until the lvalue-to-rvalue >> conversion. We can + // only see this when folding in C, so there's no >> standard to follow here. return Success(E); } >> >> >> @@ -617,6 +704,10 @@ >> } >> >> >> bool LValueExprEvaluator::VisitArraySubscriptExpr(const ArraySubscriptExpr >> *E) { >> + // FIXME: Deal with vectors as array subscript bases. >> + if (E->getBase()->getType()->isVectorType()) >> + return false; >> + >> if (!EvaluatePointer(E->getBase(), Result, Info)) return false; >> >> @@ -684,7 +775,7 @@ >> } // end anonymous namespace >> >> >> static bool EvaluatePointer(const Expr* E, LValue& Result, EvalInfo &Info) >> { >> - assert(E->getType()->hasPointerRepresentation()); >> + assert(E->isRValue() && E->getType()->hasPointerRepresentation()); >> return PointerExprEvaluator(Info, Result).Visit(E); } >> >> >> @@ -740,7 +831,6 @@ >> default: >> break; >> >> - case CK_NoOp: >> case CK_BitCast: case CK_CPointerToObjCPointerCast: case >> CK_BlockPointerToObjCPointerCast: >> @@ -810,7 +900,7 @@ >> return EvaluateLValue(SubExpr, Result, Info); } >> >> >> - return false; >> + return ExprEvaluatorBaseTy::VisitCastExpr(E); >> } >> >> >> bool PointerExprEvaluator::VisitCallExpr(const CallExpr *E) { @@ -852,7 >> +942,6 @@ >> bool VisitUnaryReal(const UnaryOperator *E) { return Visit(E->getSubExpr()); >> } >> bool VisitCastExpr(const CastExpr* E); - bool >> VisitCompoundLiteralExpr(const CompoundLiteralExpr *E); >> bool VisitInitListExpr(const InitListExpr *E); bool VisitUnaryImag(const >> UnaryOperator *E); >> // FIXME: Missing: unary -, unary ~, binary add/sub/mul/div, >> @@ -864,8 +953,7 @@ >> } // end anonymous namespace >> >> >> static bool EvaluateVector(const Expr* E, APValue& Result, EvalInfo &Info) >> { >> - if (!E->getType()->isVectorType()) >> - return false; >> + assert(E->isRValue() && E->getType()->isVectorType() &&"not a vector >> rvalue"); return VectorExprEvaluator(Info, Result).Visit(E); } >> >> >> @@ -927,20 +1015,12 @@ >> } >> return Success(Elts, E); } >> - case CK_LValueToRValue: >> - case CK_NoOp: >> - return Visit(SE); >> default: >> - return Error(E); >> + return ExprEvaluatorBaseTy::VisitCastExpr(E); >> } >> } >> >> >> bool -VectorExprEvaluator::VisitCompoundLiteralExpr(const >> CompoundLiteralExpr *E) { >> - return Visit(E->getInitializer()); >> -} >> - >> -bool >> VectorExprEvaluator::VisitInitListExpr(const InitListExpr *E) { >> const VectorType *VT = E->getType()->castAs<VectorType>(); unsigned NumInits >> = E->getNumInits(); >> @@ -1022,6 +1102,10 @@ >> >> >> //===---------------------------------------------------------------------- >> ===// >> // Integer Evaluation >> +// >> +// As a GNU extension, we support casting pointers to sufficiently-wide >> integer +// types and back in constant folding. Integer values are thus >> represented +// either as an integer-valued APValue, or as an lvalue-valued >> APValue. >> //===----------------------------------------------------------------------= >> ==// >> >> >> namespace { @@ -1105,8 +1189,7 @@ >> } >> bool VisitMemberExpr(const MemberExpr *E) { if (CheckReferencedDecl(E, >> E->getMemberDecl())) { >> - // Conservatively assume a MemberExpr will have side-effects >> - Info.EvalStatus.HasSideEffects = true; >> + VisitIgnoredValue(E->getBase()); >> return true; } >> >> >> @@ -1161,14 +1244,20 @@ >> }; >> } // end anonymous namespace >> >> >> +/// EvaluateIntegerOrLValue - Evaluate an rvalue integral-typed >> expression, and +/// produce either the integer value or a pointer. >> +/// >> +/// GCC has a heinous extension which folds casts between pointer types and >> +/// pointer-sized integral types. We support this by allowing the >> evaluation of +/// an integer rvalue to produce a pointer (represented as an >> lvalue) instead. +/// Some simple arithmetic on such values is supported >> (they are treated much >> +/// like char*). >> static bool EvaluateIntegerOrLValue(const Expr* E, APValue &Result, EvalInfo >> &Info) { >> - assert(E->getType()->isIntegralOrEnumerationType()); >> + assert(E->isRValue() && E->getType()->isIntegralOrEnumerationType()); >> return IntExprEvaluator(Info, Result).Visit(E); } >> >> >> static bool EvaluateInteger(const Expr* E, APSInt &Result, EvalInfo &Info) >> { >> - assert(E->getType()->isIntegralOrEnumerationType()); >> - >> APValue Val; >> if (!EvaluateIntegerOrLValue(E, Val, Info) || !Val.isInt()) return false; @@ >> -1197,18 +1286,6 @@ >> return Success(Val, E); } >> } >> - >> - // In C++, const, non-volatile integers initialized with ICEs are ICEs. >> - // In C, they can also be folded, although they are not ICEs. >> - if (IsConstNonVolatile(E->getType())) { >> - if (const VarDecl *VD = dyn_cast<VarDecl>(D)) { >> - APValue *V = EvaluateVarDeclInit(Info, VD); >> - if (V && V->isInt()) >> - return Success(V->getInt(), E); >> - } >> - } >> - >> - // Otherwise, random variable references are not constants. >> return false; } >> >> >> @@ -1411,6 +1488,9 @@ >> } >> >> >> bool IntExprEvaluator::VisitBinaryOperator(const BinaryOperator *E) { + if >> (E->isAssignmentOp()) >> + return Error(E->getOperatorLoc(), diag::note_invalid_subexpr_in_ice, >> E); >> + >> if (E->getOpcode() == BO_Comma) { VisitIgnoredValue(E->getLHS()); >> return Visit(E->getRHS()); @@ -1421,20 +1501,20 @@ >> // necessarily integral >> bool lhsResult, rhsResult; >> >> - if (HandleConversionToBool(E->getLHS(), lhsResult, Info)) { >> + if (EvaluateAsBooleanCondition(E->getLHS(), lhsResult, Info)) { >> // We were able to evaluate the LHS, see if we can get away with not >> // evaluating the RHS: 0 && X -> 0, 1 || X -> 1 >> if (lhsResult == (E->getOpcode() == BO_LOr)) return Success(lhsResult, E); >> >> - if (HandleConversionToBool(E->getRHS(), rhsResult, Info)) { >> + if (EvaluateAsBooleanCondition(E->getRHS(), rhsResult, Info)) { >> if (E->getOpcode() == BO_LOr) return Success(lhsResult || rhsResult, E); else >> return Success(lhsResult && rhsResult, E); } >> } else { >> - if (HandleConversionToBool(E->getRHS(), rhsResult, Info)) { >> + if (EvaluateAsBooleanCondition(E->getRHS(), rhsResult, Info)) { >> // We can't evaluate the LHS; however, sometimes the result >> // is determined by the RHS: X && 0 -> 0, X || 1 -> 1. >> if (rhsResult == (E->getOpcode() == BO_LOr) || @@ -1590,58 +1670,60 @@ >> } >> >> >> // The LHS of a constant expr is always evaluated and needed. >> - if (!Visit(E->getLHS())) >> + APValue LHSVal; >> + if (!EvaluateIntegerOrLValue(E->getLHS(), LHSVal, Info)) >> return false; // error in subexpression. >> >> - APValue RHSVal; >> - if (!EvaluateIntegerOrLValue(E->getRHS(), RHSVal, Info)) >> + if (!Visit(E->getRHS())) >> return false; + APValue &RHSVal = Result; >> >> >> // Handle cases like (unsigned long)&a + 4. >> - if (E->isAdditiveOp() && Result.isLValue() && RHSVal.isInt()) { >> - CharUnits Offset = Result.getLValueOffset(); >> + if (E->isAdditiveOp() && LHSVal.isLValue() && RHSVal.isInt()) { >> + CharUnits Offset = LHSVal.getLValueOffset(); >> CharUnits AdditionalOffset = CharUnits::fromQuantity( >> RHSVal.getInt().getZExtValue()); >> if (E->getOpcode() == BO_Add) Offset += AdditionalOffset; >> else Offset -= AdditionalOffset; >> - Result = APValue(Result.getLValueBase(), Offset); >> + Result = APValue(LHSVal.getLValueBase(), Offset); >> return true; } >> >> >> // Handle cases like 4 + (unsigned long)&a >> if (E->getOpcode() == BO_Add && - RHSVal.isLValue() && Result.isInt()) >> { >> + RHSVal.isLValue() && LHSVal.isInt()) { >> CharUnits Offset = RHSVal.getLValueOffset(); >> - Offset += CharUnits::fromQuantity(Result.getInt().getZExtValue()); >> + Offset += CharUnits::fromQuantity(LHSVal.getInt().getZExtValue()); >> Result = APValue(RHSVal.getLValueBase(), Offset); >> return true; } >> >> >> // All the following cases expect both operands to be an integer >> - if (!Result.isInt() || !RHSVal.isInt()) >> + if (!LHSVal.isInt() || !RHSVal.isInt()) >> return false; >> >> - APSInt& RHS = RHSVal.getInt(); >> + APSInt &LHS = LHSVal.getInt(); >> + APSInt &RHS = RHSVal.getInt(); >> >> >> switch (E->getOpcode()) { default: >> return Error(E->getOperatorLoc(), diag::note_invalid_subexpr_in_ice, E); - >> case BO_Mul: return Success(Result.getInt() * RHS, E); - case BO_Add: >> return Success(Result.getInt() + RHS, E); - case BO_Sub: return >> Success(Result.getInt() - RHS, E); >> - case BO_And: return Success(Result.getInt() & RHS, E); >> - case BO_Xor: return Success(Result.getInt() ^ RHS, E); >> - case BO_Or: return Success(Result.getInt() | RHS, E); >> + case BO_Mul: return Success(LHS * RHS, E); >> + case BO_Add: return Success(LHS + RHS, E); >> + case BO_Sub: return Success(LHS - RHS, E); >> + case BO_And: return Success(LHS & RHS, E); >> + case BO_Xor: return Success(LHS ^ RHS, E); >> + case BO_Or: return Success(LHS | RHS, E); >> case BO_Div: if (RHS == 0) return Error(E->getOperatorLoc(), >> diag::note_expr_divide_by_zero, E); >> - return Success(Result.getInt() / RHS, E); >> + return Success(LHS / RHS, E); >> case BO_Rem: if (RHS == 0) return Error(E->getOperatorLoc(), >> diag::note_expr_divide_by_zero, E); >> - return Success(Result.getInt() % RHS, E); >> + return Success(LHS % RHS, E); >> case BO_Shl: { // During constant-folding, a negative shift is an opposite >> shift. if (RHS.isSigned() && RHS.isNegative()) { @@ -1651,8 +1733,8 @@ >> >> >> shift_left: >> unsigned SA - = (unsigned) >> RHS.getLimitedValue(Result.getInt().getBitWidth()-1); >> - return Success(Result.getInt() << SA, E); >> + = (unsigned) RHS.getLimitedValue(LHS.getBitWidth()-1); >> + return Success(LHS << SA, E); >> } >> case BO_Shr: { // During constant-folding, a negative shift is an opposite >> shift. @@ -1663,16 +1745,16 @@ >> >> >> shift_right: >> unsigned SA = - (unsigned) >> RHS.getLimitedValue(Result.getInt().getBitWidth()-1); >> - return Success(Result.getInt() >> SA, E); >> + (unsigned) RHS.getLimitedValue(LHS.getBitWidth()-1); >> + return Success(LHS >> SA, E); >> } >> >> >> - case BO_LT: return Success(Result.getInt() < RHS, E); >> - case BO_GT: return Success(Result.getInt() > RHS, E); >> - case BO_LE: return Success(Result.getInt() <= RHS, E); >> - case BO_GE: return Success(Result.getInt() >= RHS, E); >> - case BO_EQ: return Success(Result.getInt() == RHS, E); >> - case BO_NE: return Success(Result.getInt() != RHS, E); >> + case BO_LT: return Success(LHS < RHS, E); >> + case BO_GT: return Success(LHS > RHS, E); >> + case BO_LE: return Success(LHS <= RHS, E); >> + case BO_GE: return Success(LHS >= RHS, E); >> + case BO_EQ: return Success(LHS == RHS, E); >> + case BO_NE: return Success(LHS != RHS, E); >> } >> } >> >> >> @@ -1833,7 +1915,7 @@ >> if (E->getOpcode() == UO_LNot) { // LNot's operand isn't necessarily an >> integer, so we handle it specially. bool bres; - if >> (!HandleConversionToBool(E->getSubExpr(), bres, Info)) >> + if (!EvaluateAsBooleanCondition(E->getSubExpr(), bres, Info)) >> return false; return Success(!bres, E); } >> @@ -1918,7 +2000,7 @@ >> >> >> case CK_LValueToRValue: case CK_NoOp: - return Visit(E->getSubExpr()); >> + return ExprEvaluatorBaseTy::VisitCastExpr(E); >> >> >> case CK_MemberPointerToBoolean: case CK_PointerToBoolean: @@ -1927,7 +2009,7 >> @@ >> case CK_FloatingComplexToBoolean: case CK_IntegralComplexToBoolean: { bool >> BoolResult; >> - if (!HandleConversionToBool(SubExpr, BoolResult, Info)) >> + if (!EvaluateAsBooleanCondition(SubExpr, BoolResult, Info)) >> return false; return Success(BoolResult, E); } >> @@ -2050,15 +2132,13 @@ >> bool VisitUnaryReal(const UnaryOperator *E); bool VisitUnaryImag(const >> UnaryOperator *E); >> >> >> - bool VisitDeclRefExpr(const DeclRefExpr *E); >> - >> // FIXME: Missing: array subscript of vector, member of vector, >> // ImplicitValueInitExpr >> }; >> } // end anonymous namespace >> >> >> static bool EvaluateFloat(const Expr* E, APFloat& Result, EvalInfo &Info) { >> - assert(E->getType()->isRealFloatingType()); >> + assert(E->isRValue() && E->getType()->isRealFloatingType()); >> return FloatExprEvaluator(Info, Result).Visit(E); } >> >> >> @@ -2141,21 +2221,6 @@ >> } >> } >> >> >> -bool FloatExprEvaluator::VisitDeclRefExpr(const DeclRefExpr *E) { >> - if (ExprEvaluatorBaseTy::VisitDeclRefExpr(E)) >> - return true; >> - >> - const VarDecl *VD = dyn_cast<VarDecl>(E->getDecl()); >> - if (VD && IsConstNonVolatile(VD->getType())) { >> - APValue *V = EvaluateVarDeclInit(Info, VD); >> - if (V && V->isFloat()) { >> - Result = V->getFloat(); >> - return true; >> - } >> - } >> - return false; >> -} >> - >> bool FloatExprEvaluator::VisitUnaryReal(const UnaryOperator *E) { if >> (E->getSubExpr()->getType()->isAnyComplexType()) { >> ComplexValue CV; >> @@ -2245,11 +2310,7 @@ >> >> >> switch (E->getCastKind()) { default: >> - return false; >> - >> - case CK_LValueToRValue: >> - case CK_NoOp: >> - return Visit(SubExpr); >> + return ExprEvaluatorBaseTy::VisitCastExpr(E); >> >> >> case CK_IntegralToFloating: { APSInt IntResult; >> @@ -2317,7 +2378,7 @@ >> >> >> static bool EvaluateComplex(const Expr *E, ComplexValue &Result, EvalInfo >> &Info) { >> - assert(E->getType()->isAnyComplexType()); >> + assert(E->isRValue() && E->getType()->isAnyComplexType()); >> return ComplexExprEvaluator(Info, Result).Visit(E); } >> >> >> @@ -2390,7 +2451,7 @@ >> >> >> case CK_LValueToRValue: case CK_NoOp: - return Visit(E->getSubExpr()); >> + return ExprEvaluatorBaseTy::VisitCastExpr(E); >> >> >> case CK_Dependent: case CK_GetObjCProperty: @@ -2634,27 +2695,28 @@ >> //===----------------------------------------------------------------------= >> ==// >> >> >> static bool Evaluate(APValue &Result, EvalInfo &Info, const Expr *E) { - if >> (E->getType()->isVectorType()) { >> + // In C, function designators are not lvalues, but we evaluate them as if >> they + // are. >> + if (E->isGLValue() || E->getType()->isFunctionType()) { >> + LValue LV; >> + if (!EvaluateLValue(E, LV, Info)) >> + return false; >> + LV.moveInto(Result); >> + } else if (E->getType()->isVectorType()) { >> if (!EvaluateVector(E, Result, Info)) return false; } else if >> (E->getType()->isIntegralOrEnumerationType()) { >> if (!IntExprEvaluator(Info, Result).Visit(E)) return false; - if >> (Result.isLValue() && >> - !IsGlobalLValue(Result.getLValueBase())) >> - return false; >> } else if (E->getType()->hasPointerRepresentation()) { >> LValue LV; >> if (!EvaluatePointer(E, LV, Info)) return false; - if >> (!IsGlobalLValue(LV.Base)) >> - return false; >> LV.moveInto(Result); >> } else if (E->getType()->isRealFloatingType()) { >> llvm::APFloat F(0.0); >> if (!EvaluateFloat(E, F, Info)) return false; - >> Result = APValue(F); >> } else if (E->getType()->isAnyComplexType()) { >> ComplexValue C; >> @@ -2670,25 +2732,43 @@ >> /// Evaluate - Return true if this is a constant which we can fold using >> /// any crazy technique (that has nothing to do with language standards) >> that /// we want to. If this function returns true, it returns the folded >> constant -/// in Result. >> +/// in Result. If this expression is a glvalue, an lvalue-to-rvalue >> conversion +/// will be applied to the result. >> bool Expr::Evaluate(EvalResult &Result, const ASTContext &Ctx) const { >> EvalInfo Info(Ctx, Result); >> - return ::Evaluate(Result.Val, Info, this); >> + >> + if (!::Evaluate(Result.Val, Info, this)) >> + return false; >> + >> + if (isGLValue()) { >> + LValue LV; >> + LV.setFrom(Result.Val); >> + return HandleLValueToRValueConversion(Info, getType(), LV, Result.Val); >> + } else if (Result.Val.isLValue()) { >> + // FIXME: We don't allow expressions to fold to references to locals. >> Code >> + // which calls Evaluate() isn't ready for that yet. For instance, we >> don't + // have any checking that the initializer of a pointer in C is an >> address + // constant. >> + if (!IsGlobalLValue(Result.Val.getLValueBase())) >> + return false; >> + } >> + >> + return true; >> } >> >> >> bool Expr::EvaluateAsBooleanCondition(bool &Result, const ASTContext &Ctx) >> const { - EvalStatus Scratch; >> - EvalInfo Info(Ctx, Scratch); >> - >> - return HandleConversionToBool(this, Result, Info); >> + EvalResult Scratch; >> + return Evaluate(Scratch, Ctx) && HandleConversionToBool(Scratch.Val, >> Result); >> } >> >> >> bool Expr::EvaluateAsInt(APSInt &Result, const ASTContext &Ctx) const { - >> EvalStatus Scratch; >> - EvalInfo Info(Ctx, Scratch); >> - >> - return EvaluateInteger(this, Result, Info) && !Scratch.HasSideEffects; >> + EvalResult ExprResult; >> + if (!Evaluate(ExprResult, Ctx) || ExprResult.HasSideEffects || >> + !ExprResult.Val.isInt()) >> + return false; >> + Result = ExprResult.Val.getInt(); >> + return true; >> } >> >> >> bool Expr::EvaluateAsLValue(EvalResult &Result, const ASTContext &Ctx) >> const { @@ -3184,11 +3264,7 @@ >> if (Loc) *Loc = d.Loc; return false; } >> - EvalResult EvalResult; >> - if (!Evaluate(EvalResult, Ctx)) >> + if (!EvaluateAsInt(Result, Ctx)) >> llvm_unreachable("ICE cannot be evaluated!"); - >> assert(!EvalResult.HasSideEffects && "ICE with side effects!"); - >> assert(EvalResult.Val.isInt() && "ICE that isn't integer!"); - Result = >> EvalResult.Val.getInt(); >> return true; } >> >> >> Modified: cfe/trunk/test/SemaCXX/i-c-e-cxx.cpp >> URL: >> http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/i-c-e-cxx.cpp?re >> v=142844&r1=142843&r2=142844&view=diff >> =========================================================================== >> === >> --- cfe/trunk/test/SemaCXX/i-c-e-cxx.cpp (original) >> +++ cfe/trunk/test/SemaCXX/i-c-e-cxx.cpp Mon Oct 24 16:07:08 2011 >> @@ -66,3 +66,6 @@ >> int arr[nonconst]; // expected-warning {{folded to constant array as an >> extension}} const int castfloat = static_cast<int>(1.0); int arr2[castfloat]; >> // ok >> + >> +extern const int &Recurse1; >> +const int &Recurse2 = Recurse1, &Recurse1 = Recurse2; >> >> >> >> _______________________________________________ >> cfe-commits mailing list [email protected] >> http://lists.cs.uiuc.edu/mailman/listinfo/cfe-commits >> > > -David > > > > _______________________________________________ cfe-commits mailing list [email protected] http://lists.cs.uiuc.edu/mailman/listinfo/cfe-commits
