Fix PR 4594 by refactoring almost all casting logic from GRExprEngine::VisitCast
to SValuator::EvalCast. In the process, the StoreManagers now use this new cast
machinery, and the hack in GRExprEngine::EvalBind to handle implicit casts
involving OSAtomicCompareAndSwap and friends has been removed (and replaced with
logic closer to the logic specific to those functions).
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@76641 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/SValuator.cpp b/lib/Analysis/SValuator.cpp
new file mode 100644
index 0000000..b06b94f
--- /dev/null
+++ b/lib/Analysis/SValuator.cpp
@@ -0,0 +1,123 @@
+// 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: For TypedViewRegions, we should handle the case where the
+ // underlying symbolic pointer is a function pointer or
+ // block pointer.
+
+ // 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));
+}
\ No newline at end of file