X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FAnalysis%2FLint.cpp;h=38d677d502a750f34a10d38e35c90ce88f009305;hb=39b5abf507b43da6b92f68b86406e0015ead18e9;hp=b1aa4ca6884d21fd38294d82ef9ddc7b3e974db6;hpb=d3b6e41ffb6aae6a1efc31b0a9f9050234570841;p=oota-llvm.git diff --git a/lib/Analysis/Lint.cpp b/lib/Analysis/Lint.cpp index b1aa4ca6884..38d677d502a 100644 --- a/lib/Analysis/Lint.cpp +++ b/lib/Analysis/Lint.cpp @@ -70,8 +70,8 @@ namespace { void visitCallSite(CallSite CS); void visitMemoryReference(Instruction &I, Value *Ptr, - unsigned Size, unsigned Align, - const Type *Ty, unsigned Flags); + uint64_t Size, unsigned Align, + Type *Ty, unsigned Flags); void visitCallInst(CallInst &I); void visitInvokeInst(InvokeInst &I); @@ -108,7 +108,9 @@ namespace { raw_string_ostream MessagesStr; static char ID; // Pass identification, replacement for typeid - Lint() : FunctionPass(&ID), MessagesStr(Messages) {} + Lint() : FunctionPass(ID), MessagesStr(Messages) { + initializeLintPass(*PassRegistry::getPassRegistry()); + } virtual bool runOnFunction(Function &F); @@ -129,12 +131,6 @@ namespace { } } - void WriteType(const Type *T) { - if (!T) return; - MessagesStr << ' '; - WriteTypeSymbolic(MessagesStr, T, Mod); - } - // CheckFailed - A check failed, so print out the condition and the message // that failed. This provides a nice place to put a breakpoint if you want // to see why something is not correct. @@ -147,28 +143,16 @@ namespace { WriteValue(V3); WriteValue(V4); } - - void CheckFailed(const Twine &Message, const Value *V1, - const Type *T2, const Value *V3 = 0) { - MessagesStr << Message.str() << "\n"; - WriteValue(V1); - WriteType(T2); - WriteValue(V3); - } - - void CheckFailed(const Twine &Message, const Type *T1, - const Type *T2 = 0, const Type *T3 = 0) { - MessagesStr << Message.str() << "\n"; - WriteType(T1); - WriteType(T2); - WriteType(T3); - } }; } char Lint::ID = 0; -static RegisterPass -X("lint", "Statically lint-checks LLVM IR", false, true); +INITIALIZE_PASS_BEGIN(Lint, "lint", "Statically lint-checks LLVM IR", + false, true) +INITIALIZE_PASS_DEPENDENCY(DominatorTree) +INITIALIZE_AG_DEPENDENCY(AliasAnalysis) +INITIALIZE_PASS_END(Lint, "lint", "Statically lint-checks LLVM IR", + false, true) // Assert - We know that cond should be true, if not print an error message. #define Assert(C, M) \ @@ -201,20 +185,23 @@ void Lint::visitFunction(Function &F) { // fairly common mistake to neglect to name a function. Assert1(F.hasName() || F.hasLocalLinkage(), "Unusual: Unnamed function with non-local linkage", &F); + + // TODO: Check for irreducible control flow. } void Lint::visitCallSite(CallSite CS) { Instruction &I = *CS.getInstruction(); Value *Callee = CS.getCalledValue(); - visitMemoryReference(I, Callee, ~0u, 0, 0, MemRef::Callee); + visitMemoryReference(I, Callee, AliasAnalysis::UnknownSize, + 0, 0, MemRef::Callee); if (Function *F = dyn_cast(findValue(Callee, /*OffsetOk=*/false))) { Assert1(CS.getCallingConv() == F->getCallingConv(), "Undefined behavior: Caller and callee calling convention differ", &I); - const FunctionType *FT = F->getFunctionType(); + FunctionType *FT = F->getFunctionType(); unsigned NumActualArgs = unsigned(CS.arg_end()-CS.arg_begin()); Assert1(FT->isVarArg() ? @@ -223,7 +210,12 @@ void Lint::visitCallSite(CallSite CS) { "Undefined behavior: Call argument count mismatches callee " "argument count", &I); + Assert1(FT->getReturnType() == I.getType(), + "Undefined behavior: Call return type mismatches " + "callee return type", &I); + // Check argument types (in case the callee was casted) and attributes. + // TODO: Verify that caller and callee attributes are compatible. Function::arg_iterator PI = F->arg_begin(), PE = F->arg_end(); CallSite::arg_iterator AI = CS.arg_begin(), AE = CS.arg_end(); for (; AI != AE; ++AI) { @@ -234,20 +226,21 @@ void Lint::visitCallSite(CallSite CS) { "Undefined behavior: Call argument type mismatches " "callee parameter type", &I); - // Check that noalias arguments don't alias other arguments. The - // AliasAnalysis API isn't expressive enough for what we really want - // to do. Known partial overlap is not distinguished from the case - // where nothing is known. + // Check that noalias arguments don't alias other arguments. This is + // not fully precise because we don't know the sizes of the dereferenced + // memory regions. if (Formal->hasNoAliasAttr() && Actual->getType()->isPointerTy()) - for (CallSite::arg_iterator BI = CS.arg_begin(); BI != AE; ++BI) { - Assert1(AI == BI || - AA->alias(*AI, ~0u, *BI, ~0u) != AliasAnalysis::MustAlias, - "Unusual: noalias argument aliases another argument", &I); - } + for (CallSite::arg_iterator BI = CS.arg_begin(); BI != AE; ++BI) + if (AI != BI && (*BI)->getType()->isPointerTy()) { + AliasAnalysis::AliasResult Result = AA->alias(*AI, *BI); + Assert1(Result != AliasAnalysis::MustAlias && + Result != AliasAnalysis::PartialAlias, + "Unusual: noalias argument aliases another argument", &I); + } // Check that an sret argument points to valid memory. if (Formal->hasStructRetAttr() && Actual->getType()->isPointerTy()) { - const Type *Ty = + Type *Ty = cast(Formal->getType())->getElementType(); visitMemoryReference(I, Actual, AA->getTypeStoreSize(Ty), TD ? TD->getABITypeAlignment(Ty) : 0, @@ -276,15 +269,17 @@ void Lint::visitCallSite(CallSite CS) { case Intrinsic::memcpy: { MemCpyInst *MCI = cast(&I); // TODO: If the size is known, use it. - visitMemoryReference(I, MCI->getDest(), ~0u, MCI->getAlignment(), 0, + visitMemoryReference(I, MCI->getDest(), AliasAnalysis::UnknownSize, + MCI->getAlignment(), 0, MemRef::Write); - visitMemoryReference(I, MCI->getSource(), ~0u, MCI->getAlignment(), 0, + visitMemoryReference(I, MCI->getSource(), AliasAnalysis::UnknownSize, + MCI->getAlignment(), 0, MemRef::Read); // Check that the memcpy arguments don't overlap. The AliasAnalysis API // isn't expressive enough for what we really want to do. Known partial // overlap is not distinguished from the case where nothing is known. - unsigned Size = 0; + uint64_t Size = 0; if (const ConstantInt *Len = dyn_cast(findValue(MCI->getLength(), /*OffsetOk=*/false))) @@ -298,16 +293,19 @@ void Lint::visitCallSite(CallSite CS) { case Intrinsic::memmove: { MemMoveInst *MMI = cast(&I); // TODO: If the size is known, use it. - visitMemoryReference(I, MMI->getDest(), ~0u, MMI->getAlignment(), 0, + visitMemoryReference(I, MMI->getDest(), AliasAnalysis::UnknownSize, + MMI->getAlignment(), 0, MemRef::Write); - visitMemoryReference(I, MMI->getSource(), ~0u, MMI->getAlignment(), 0, + visitMemoryReference(I, MMI->getSource(), AliasAnalysis::UnknownSize, + MMI->getAlignment(), 0, MemRef::Read); break; } case Intrinsic::memset: { MemSetInst *MSI = cast(&I); // TODO: If the size is known, use it. - visitMemoryReference(I, MSI->getDest(), ~0u, MSI->getAlignment(), 0, + visitMemoryReference(I, MSI->getDest(), AliasAnalysis::UnknownSize, + MSI->getAlignment(), 0, MemRef::Write); break; } @@ -317,24 +315,26 @@ void Lint::visitCallSite(CallSite CS) { "Undefined behavior: va_start called in a non-varargs function", &I); - visitMemoryReference(I, CS.getArgument(0), ~0u, 0, 0, - MemRef::Read | MemRef::Write); + visitMemoryReference(I, CS.getArgument(0), AliasAnalysis::UnknownSize, + 0, 0, MemRef::Read | MemRef::Write); break; case Intrinsic::vacopy: - visitMemoryReference(I, CS.getArgument(0), ~0u, 0, 0, MemRef::Write); - visitMemoryReference(I, CS.getArgument(1), ~0u, 0, 0, MemRef::Read); + visitMemoryReference(I, CS.getArgument(0), AliasAnalysis::UnknownSize, + 0, 0, MemRef::Write); + visitMemoryReference(I, CS.getArgument(1), AliasAnalysis::UnknownSize, + 0, 0, MemRef::Read); break; case Intrinsic::vaend: - visitMemoryReference(I, CS.getArgument(0), ~0u, 0, 0, - MemRef::Read | MemRef::Write); + visitMemoryReference(I, CS.getArgument(0), AliasAnalysis::UnknownSize, + 0, 0, MemRef::Read | MemRef::Write); break; case Intrinsic::stackrestore: // Stackrestore doesn't read or write memory, but it sets the // stack pointer, which the compiler may read from or write to // at any time, so check it for both readability and writeability. - visitMemoryReference(I, CS.getArgument(0), ~0u, 0, 0, - MemRef::Read | MemRef::Write); + visitMemoryReference(I, CS.getArgument(0), AliasAnalysis::UnknownSize, + 0, 0, MemRef::Read | MemRef::Write); break; } } @@ -361,9 +361,10 @@ void Lint::visitReturnInst(ReturnInst &I) { } // TODO: Check that the reference is in bounds. +// TODO: Check readnone/readonly function attributes. void Lint::visitMemoryReference(Instruction &I, - Value *Ptr, unsigned Size, unsigned Align, - const Type *Ty, unsigned Flags) { + Value *Ptr, uint64_t Size, unsigned Align, + Type *Ty, unsigned Flags) { // If no memory is being referenced, it doesn't matter if the pointer // is valid. if (Size == 0) @@ -501,15 +502,21 @@ void Lint::visitAllocaInst(AllocaInst &I) { // This isn't undefined behavior, it's just an obvious pessimization. Assert1(&I.getParent()->getParent()->getEntryBlock() == I.getParent(), "Pessimization: Static alloca outside of entry block", &I); + + // TODO: Check for an unusual size (MSB set?) } void Lint::visitVAArgInst(VAArgInst &I) { - visitMemoryReference(I, I.getOperand(0), ~0u, 0, 0, + visitMemoryReference(I, I.getOperand(0), AliasAnalysis::UnknownSize, 0, 0, MemRef::Read | MemRef::Write); } void Lint::visitIndirectBrInst(IndirectBrInst &I) { - visitMemoryReference(I, I.getAddress(), ~0u, 0, 0, MemRef::Branchee); + visitMemoryReference(I, I.getAddress(), AliasAnalysis::UnknownSize, 0, 0, + MemRef::Branchee); + + Assert1(I.getNumDestinations() != 0, + "Undefined behavior: indirectbr with no destinations", &I); } void Lint::visitExtractElementInst(ExtractElementInst &I) { @@ -560,7 +567,7 @@ Value *Lint::findValueImpl(Value *V, bool OffsetOk, // TODO: Look through eliminable cast pairs. // TODO: Look through calls with unique return values. // TODO: Look through vector insert/extract/shuffle. - V = OffsetOk ? V->getUnderlyingObject() : V->stripPointerCasts(); + V = OffsetOk ? GetUnderlyingObject(V, TD) : V->stripPointerCasts(); if (LoadInst *L = dyn_cast(V)) { BasicBlock::iterator BBI = L; BasicBlock *BB = L->getParent(); @@ -576,16 +583,16 @@ Value *Lint::findValueImpl(Value *V, bool OffsetOk, BBI = BB->end(); } } else if (PHINode *PN = dyn_cast(V)) { - if (Value *W = PN->hasConstantValue(DT)) - return findValueImpl(W, OffsetOk, Visited); + if (Value *W = PN->hasConstantValue()) + if (W != V) + return findValueImpl(W, OffsetOk, Visited); } else if (CastInst *CI = dyn_cast(V)) { if (CI->isNoopCast(TD ? TD->getIntPtrType(V->getContext()) : Type::getInt64Ty(V->getContext()))) return findValueImpl(CI->getOperand(0), OffsetOk, Visited); } else if (ExtractValueInst *Ex = dyn_cast(V)) { if (Value *W = FindInsertedValue(Ex->getAggregateOperand(), - Ex->idx_begin(), - Ex->idx_end())) + Ex->getIndices())) if (W != V) return findValueImpl(W, OffsetOk, Visited); } else if (ConstantExpr *CE = dyn_cast(V)) { @@ -598,10 +605,8 @@ Value *Lint::findValueImpl(Value *V, bool OffsetOk, Type::getInt64Ty(V->getContext()))) return findValueImpl(CE->getOperand(0), OffsetOk, Visited); } else if (CE->getOpcode() == Instruction::ExtractValue) { - const SmallVector &Indices = CE->getIndices(); - if (Value *W = FindInsertedValue(CE->getOperand(0), - Indices.begin(), - Indices.end())) + ArrayRef Indices = CE->getIndices(); + if (Value *W = FindInsertedValue(CE->getOperand(0), Indices)) if (W != V) return findValueImpl(W, OffsetOk, Visited); } @@ -609,9 +614,8 @@ Value *Lint::findValueImpl(Value *V, bool OffsetOk, // As a last resort, try SimplifyInstruction or constant folding. if (Instruction *Inst = dyn_cast(V)) { - if (Value *W = SimplifyInstruction(Inst, TD)) - if (W != Inst) - return findValueImpl(W, OffsetOk, Visited); + if (Value *W = SimplifyInstruction(Inst, TD, DT)) + return findValueImpl(W, OffsetOk, Visited); } else if (ConstantExpr *CE = dyn_cast(V)) { if (Value *W = ConstantFoldConstantExpression(CE, TD)) if (W != V)