diff options
Diffstat (limited to 'lib/Analysis/MemoryBuiltins.cpp')
| -rw-r--r-- | lib/Analysis/MemoryBuiltins.cpp | 39 |
1 files changed, 30 insertions, 9 deletions
diff --git a/lib/Analysis/MemoryBuiltins.cpp b/lib/Analysis/MemoryBuiltins.cpp index 8d99ec3..b986b32 100644 --- a/lib/Analysis/MemoryBuiltins.cpp +++ b/lib/Analysis/MemoryBuiltins.cpp @@ -64,7 +64,7 @@ static const AllocFnsTy AllocationFnData[] = { {"realloc", ReallocLike, 2, 1, -1}, {"reallocf", ReallocLike, 2, 1, -1}, {"strdup", StrDupLike, 1, -1, -1}, - {"strndup", StrDupLike, 2, -1, -1} + {"strndup", StrDupLike, 2, 1, -1} }; @@ -358,11 +358,16 @@ ObjectSizeOffsetVisitor::ObjectSizeOffsetVisitor(const TargetData *TD, SizeOffsetType ObjectSizeOffsetVisitor::compute(Value *V) { V = V->stripPointerCasts(); + if (Instruction *I = dyn_cast<Instruction>(V)) { + // If we have already seen this instruction, bail out. Cycles can happen in + // unreachable code after constant propagation. + if (!SeenInsts.insert(I)) + return unknown(); - if (GEPOperator *GEP = dyn_cast<GEPOperator>(V)) - return visitGEPOperator(*GEP); - if (Instruction *I = dyn_cast<Instruction>(V)) + if (GEPOperator *GEP = dyn_cast<GEPOperator>(V)) + return visitGEPOperator(*GEP); return visit(*I); + } if (Argument *A = dyn_cast<Argument>(V)) return visitArgument(*A); if (ConstantPointerNull *P = dyn_cast<ConstantPointerNull>(V)) @@ -371,9 +376,12 @@ SizeOffsetType ObjectSizeOffsetVisitor::compute(Value *V) { return visitGlobalVariable(*GV); if (UndefValue *UV = dyn_cast<UndefValue>(V)) return visitUndefValue(*UV); - if (ConstantExpr *CE = dyn_cast<ConstantExpr>(V)) + if (ConstantExpr *CE = dyn_cast<ConstantExpr>(V)) { if (CE->getOpcode() == Instruction::IntToPtr) return unknown(); // clueless + if (CE->getOpcode() == Instruction::GetElementPtr) + return visitGEPOperator(cast<GEPOperator>(*CE)); + } DEBUG(dbgs() << "ObjectSizeOffsetVisitor::compute() unhandled value: " << *V << '\n'); @@ -414,8 +422,21 @@ SizeOffsetType ObjectSizeOffsetVisitor::visitCallSite(CallSite CS) { // handle strdup-like functions separately if (FnData->AllocTy == StrDupLike) { - // TODO - return unknown(); + APInt Size(IntTyBits, GetStringLength(CS.getArgument(0))); + if (!Size) + return unknown(); + + // strndup limits strlen + if (FnData->FstParam > 0) { + ConstantInt *Arg= dyn_cast<ConstantInt>(CS.getArgument(FnData->FstParam)); + if (!Arg) + return unknown(); + + APInt MaxSize = Arg->getValue().zextOrSelf(IntTyBits); + if (Size.ugt(MaxSize)) + Size = MaxSize + 1; + } + return std::make_pair(Size, Zero); } ConstantInt *Arg = dyn_cast<ConstantInt>(CS.getArgument(FnData->FstParam)); @@ -512,8 +533,7 @@ SizeOffsetType ObjectSizeOffsetVisitor::visitInstruction(Instruction &I) { ObjectSizeOffsetEvaluator::ObjectSizeOffsetEvaluator(const TargetData *TD, LLVMContext &Context) -: TD(TD), Context(Context), Builder(Context, TargetFolder(TD)), -Visitor(TD, Context) { +: TD(TD), Context(Context), Builder(Context, TargetFolder(TD)) { IntTy = TD->getIntPtrType(Context); Zero = ConstantInt::get(IntTy, 0); } @@ -538,6 +558,7 @@ SizeOffsetEvalType ObjectSizeOffsetEvaluator::compute(Value *V) { } SizeOffsetEvalType ObjectSizeOffsetEvaluator::compute_(Value *V) { + ObjectSizeOffsetVisitor Visitor(TD, Context); SizeOffsetType Const = Visitor.compute(V); if (Visitor.bothKnown(Const)) return std::make_pair(ConstantInt::get(Context, Const.first), |