diff options
Diffstat (limited to 'contrib/llvm/tools/clang/lib/Checker/SValuator.cpp')
-rw-r--r-- | contrib/llvm/tools/clang/lib/Checker/SValuator.cpp | 157 |
1 files changed, 157 insertions, 0 deletions
diff --git a/contrib/llvm/tools/clang/lib/Checker/SValuator.cpp b/contrib/llvm/tools/clang/lib/Checker/SValuator.cpp new file mode 100644 index 0000000..542fc1b --- /dev/null +++ b/contrib/llvm/tools/clang/lib/Checker/SValuator.cpp @@ -0,0 +1,157 @@ +// SValuator.cpp - Basic class for all SValuator implementations --*- C++ -*--// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +// This file defines SValuator, the base class for all (complete) SValuator +// implementations. +// +//===----------------------------------------------------------------------===// + +#include "clang/Checker/PathSensitive/SValuator.h" +#include "clang/Checker/PathSensitive/GRState.h" + +using namespace clang; + + +SVal SValuator::EvalBinOp(const GRState *ST, BinaryOperator::Opcode Op, + SVal L, SVal R, QualType T) { + + if (L.isUndef() || R.isUndef()) + return UndefinedVal(); + + if (L.isUnknown() || R.isUnknown()) + return UnknownVal(); + + if (isa<Loc>(L)) { + if (isa<Loc>(R)) + return EvalBinOpLL(Op, cast<Loc>(L), cast<Loc>(R), T); + + return EvalBinOpLN(ST, Op, cast<Loc>(L), cast<NonLoc>(R), T); + } + + if (isa<Loc>(R)) { + // Support pointer arithmetic where the increment/decrement operand + // is on the left and the pointer on the right. + assert(Op == BinaryOperator::Add || Op == BinaryOperator::Sub); + + // Commute the operands. + return EvalBinOpLN(ST, Op, cast<Loc>(R), cast<NonLoc>(L), T); + } + + return EvalBinOpNN(ST, Op, cast<NonLoc>(L), cast<NonLoc>(R), T); +} + +DefinedOrUnknownSVal SValuator::EvalEQ(const GRState *ST, + DefinedOrUnknownSVal L, + DefinedOrUnknownSVal R) { + return cast<DefinedOrUnknownSVal>(EvalBinOp(ST, BinaryOperator::EQ, L, R, + ValMgr.getContext().IntTy)); +} + +SVal SValuator::EvalCast(SVal val, QualType castTy, QualType originalTy) { + if (val.isUnknownOrUndef() || castTy == originalTy) + return val; + + ASTContext &C = ValMgr.getContext(); + + // For const casts, just propagate the value. + if (!castTy->isVariableArrayType() && !originalTy->isVariableArrayType()) + if (C.hasSameUnqualifiedType(castTy, originalTy)) + return val; + + // Check for casts to real or complex numbers. We don't handle these at all + // right now. + if (castTy->isFloatingType() || castTy->isAnyComplexType()) + return UnknownVal(); + + // Check for casts from integers to integers. + if (castTy->isIntegerType() && originalTy->isIntegerType()) + return EvalCastNL(cast<NonLoc>(val), castTy); + + // Check for casts from pointers to integers. + if (castTy->isIntegerType() && Loc::IsLocType(originalTy)) + return EvalCastL(cast<Loc>(val), castTy); + + // Check for casts from integers to pointers. + if (Loc::IsLocType(castTy) && originalTy->isIntegerType()) { + if (nonloc::LocAsInteger *LV = dyn_cast<nonloc::LocAsInteger>(&val)) { + if (const MemRegion *R = LV->getLoc().getAsRegion()) { + StoreManager &storeMgr = ValMgr.getStateManager().getStoreManager(); + R = storeMgr.CastRegion(R, castTy); + return R ? SVal(loc::MemRegionVal(R)) : UnknownVal(); + } + return LV->getLoc(); + } + goto DispatchCast; + } + + // Just pass through function and block pointers. + if (originalTy->isBlockPointerType() || originalTy->isFunctionPointerType()) { + assert(Loc::IsLocType(castTy)); + return val; + } + + // Check for casts from array type to another type. + if (originalTy->isArrayType()) { + // We will always decay to a pointer. + val = ValMgr.getStateManager().ArrayToPointer(cast<Loc>(val)); + + // Are we casting from an array to a pointer? If so just pass on + // the decayed value. + if (castTy->isPointerType()) + return val; + + // Are we casting from an array to an integer? If so, cast the decayed + // pointer value to an integer. + assert(castTy->isIntegerType()); + + // FIXME: Keep these here for now in case we decide soon that we + // need the original decayed type. + // QualType elemTy = cast<ArrayType>(originalTy)->getElementType(); + // QualType pointerTy = C.getPointerType(elemTy); + return EvalCastL(cast<Loc>(val), castTy); + } + + // Check for casts from a region to a specific type. + if (const MemRegion *R = val.getAsRegion()) { + // FIXME: We should handle the case where we strip off view layers to get + // to a desugared type. + + assert(Loc::IsLocType(castTy)); + // We get a symbolic function pointer for a dereference of a function + // pointer, but it is of function type. Example: + + // struct FPRec { + // void (*my_func)(int * x); + // }; + // + // int bar(int x); + // + // int f1_a(struct FPRec* foo) { + // int x; + // (*foo->my_func)(&x); + // return bar(x)+1; // no-warning + // } + + assert(Loc::IsLocType(originalTy) || originalTy->isFunctionType() || + originalTy->isBlockPointerType()); + + StoreManager &storeMgr = ValMgr.getStateManager().getStoreManager(); + + // Delegate to store manager to get the result of casting a region to a + // different type. If the MemRegion* returned is NULL, this expression + // evaluates to UnknownVal. + R = storeMgr.CastRegion(R, castTy); + return R ? SVal(loc::MemRegionVal(R)) : UnknownVal(); + } + +DispatchCast: + // All other cases. + return isa<Loc>(val) ? EvalCastL(cast<Loc>(val), castTy) + : EvalCastNL(cast<NonLoc>(val), castTy); +} |