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// 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;
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 (C.getCanonicalType(castTy).getUnqualifiedType() ==
C.getCanonicalType(originalTy).getUnqualifiedType())
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)) {
// Just unpackage the lval and return it.
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.
const StoreManager::CastResult& Res = storeMgr.CastRegion(state, R, castTy);
// Inspect the result. If the MemRegion* returned is NULL, this
// expression evaluates to UnknownVal.
R = Res.getRegion();
if (R)
return CastResult(Res.getState(), loc::MemRegionVal(R));
return CastResult(Res.getState(), UnknownVal());
}
// All other cases.
DispatchCast:
return CastResult(state,
isa<Loc>(val) ? EvalCastL(cast<Loc>(val), castTy)
: EvalCastNL(cast<NonLoc>(val), castTy));
}
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