| // 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/Analysis/PathSensitive/SValuator.h" |
| #include "clang/Analysis/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)); |
| } |
| |
| SValuator::CastResult SValuator::EvalCast(SVal val, const GRState *state, |
| QualType castTy, QualType originalTy){ |
| |
| if (val.isUnknownOrUndef() || castTy == originalTy) |
| return CastResult(state, val); |
| |
| ASTContext &C = ValMgr.getContext(); |
| |
| // For const casts, just propagate the value. |
| if (!castTy->isVariableArrayType() && !originalTy->isVariableArrayType()) |
| if (C.hasSameUnqualifiedType(castTy, originalTy)) |
| return CastResult(state, val); |
| |
| // Check for casts from pointers to integers. |
| if (castTy->isIntegerType() && Loc::IsLocType(originalTy)) |
| return CastResult(state, 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 ? CastResult(state, loc::MemRegionVal(R)) |
| : CastResult(state, UnknownVal()); |
| } |
| return CastResult(state, LV->getLoc()); |
| } |
| goto DispatchCast; |
| } |
| |
| // Just pass through function and block pointers. |
| if (originalTy->isBlockPointerType() || originalTy->isFunctionPointerType()) { |
| assert(Loc::IsLocType(castTy)); |
| return CastResult(state, 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 CastResult(state, 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 CastResult(state, 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 ? CastResult(state, loc::MemRegionVal(R)) |
| : CastResult(state, UnknownVal()); |
| } |
| |
| DispatchCast: |
| // All other cases. |
| return CastResult(state, |
| isa<Loc>(val) ? EvalCastL(cast<Loc>(val), castTy) |
| : EvalCastNL(cast<NonLoc>(val), castTy)); |
| } |
| |
| SValuator::DefinedOrUnknownCastResult |
| SValuator::EvalCast(DefinedOrUnknownSVal V, const GRState *ST, |
| QualType castTy, QualType originalType) { |
| SValuator::CastResult X = EvalCast((SVal) V, ST, castTy, originalType); |
| return DefinedOrUnknownCastResult(X.getState(), |
| cast<DefinedOrUnknownSVal>(X.getSVal())); |
| } |