Chris Lattner has strong opinions about directory
layout. :)
Rename the 'EntoSA' directories to 'StaticAnalyzer'.
Internally we will still use the 'ento' namespace
for the analyzer engine (unless there are further
sabre rattlings...).
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@122514 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/StaticAnalyzer/Store.cpp b/lib/StaticAnalyzer/Store.cpp
new file mode 100644
index 0000000..f1b8338
--- /dev/null
+++ b/lib/StaticAnalyzer/Store.cpp
@@ -0,0 +1,334 @@
+//== Store.cpp - Interface for maps from Locations to Values ----*- C++ -*--==//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defined the types Store and StoreManager.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/StaticAnalyzer/PathSensitive/Store.h"
+#include "clang/StaticAnalyzer/PathSensitive/GRState.h"
+#include "clang/AST/CharUnits.h"
+
+using namespace clang;
+using namespace ento;
+
+StoreManager::StoreManager(GRStateManager &stateMgr)
+ : svalBuilder(stateMgr.getSValBuilder()), StateMgr(stateMgr),
+ MRMgr(svalBuilder.getRegionManager()), Ctx(stateMgr.getContext()) {}
+
+Store StoreManager::EnterStackFrame(const GRState *state,
+ const StackFrameContext *frame) {
+ return state->getStore();
+}
+
+const MemRegion *StoreManager::MakeElementRegion(const MemRegion *Base,
+ QualType EleTy, uint64_t index) {
+ NonLoc idx = svalBuilder.makeArrayIndex(index);
+ return MRMgr.getElementRegion(EleTy, idx, Base, svalBuilder.getContext());
+}
+
+// FIXME: Merge with the implementation of the same method in MemRegion.cpp
+static bool IsCompleteType(ASTContext &Ctx, QualType Ty) {
+ if (const RecordType *RT = Ty->getAs<RecordType>()) {
+ const RecordDecl *D = RT->getDecl();
+ if (!D->getDefinition())
+ return false;
+ }
+
+ return true;
+}
+
+const ElementRegion *StoreManager::GetElementZeroRegion(const MemRegion *R,
+ QualType T) {
+ NonLoc idx = svalBuilder.makeZeroArrayIndex();
+ assert(!T.isNull());
+ return MRMgr.getElementRegion(T, idx, R, Ctx);
+}
+
+const MemRegion *StoreManager::CastRegion(const MemRegion *R, QualType CastToTy) {
+
+ ASTContext& Ctx = StateMgr.getContext();
+
+ // Handle casts to Objective-C objects.
+ if (CastToTy->isObjCObjectPointerType())
+ return R->StripCasts();
+
+ if (CastToTy->isBlockPointerType()) {
+ // FIXME: We may need different solutions, depending on the symbol
+ // involved. Blocks can be casted to/from 'id', as they can be treated
+ // as Objective-C objects. This could possibly be handled by enhancing
+ // our reasoning of downcasts of symbolic objects.
+ if (isa<CodeTextRegion>(R) || isa<SymbolicRegion>(R))
+ return R;
+
+ // We don't know what to make of it. Return a NULL region, which
+ // will be interpretted as UnknownVal.
+ return NULL;
+ }
+
+ // Now assume we are casting from pointer to pointer. Other cases should
+ // already be handled.
+ QualType PointeeTy = CastToTy->getAs<PointerType>()->getPointeeType();
+ QualType CanonPointeeTy = Ctx.getCanonicalType(PointeeTy);
+
+ // Handle casts to void*. We just pass the region through.
+ if (CanonPointeeTy.getLocalUnqualifiedType() == Ctx.VoidTy)
+ return R;
+
+ // Handle casts from compatible types.
+ if (R->isBoundable())
+ if (const TypedRegion *TR = dyn_cast<TypedRegion>(R)) {
+ QualType ObjTy = Ctx.getCanonicalType(TR->getValueType());
+ if (CanonPointeeTy == ObjTy)
+ return R;
+ }
+
+ // Process region cast according to the kind of the region being cast.
+ switch (R->getKind()) {
+ case MemRegion::CXXThisRegionKind:
+ case MemRegion::GenericMemSpaceRegionKind:
+ case MemRegion::StackLocalsSpaceRegionKind:
+ case MemRegion::StackArgumentsSpaceRegionKind:
+ case MemRegion::HeapSpaceRegionKind:
+ case MemRegion::UnknownSpaceRegionKind:
+ case MemRegion::NonStaticGlobalSpaceRegionKind:
+ case MemRegion::StaticGlobalSpaceRegionKind: {
+ assert(0 && "Invalid region cast");
+ break;
+ }
+
+ case MemRegion::FunctionTextRegionKind:
+ case MemRegion::BlockTextRegionKind:
+ case MemRegion::BlockDataRegionKind:
+ case MemRegion::StringRegionKind:
+ // FIXME: Need to handle arbitrary downcasts.
+ case MemRegion::SymbolicRegionKind:
+ case MemRegion::AllocaRegionKind:
+ case MemRegion::CompoundLiteralRegionKind:
+ case MemRegion::FieldRegionKind:
+ case MemRegion::ObjCIvarRegionKind:
+ case MemRegion::VarRegionKind:
+ case MemRegion::CXXTempObjectRegionKind:
+ case MemRegion::CXXBaseObjectRegionKind:
+ return MakeElementRegion(R, PointeeTy);
+
+ case MemRegion::ElementRegionKind: {
+ // If we are casting from an ElementRegion to another type, the
+ // algorithm is as follows:
+ //
+ // (1) Compute the "raw offset" of the ElementRegion from the
+ // base region. This is done by calling 'getAsRawOffset()'.
+ //
+ // (2a) If we get a 'RegionRawOffset' after calling
+ // 'getAsRawOffset()', determine if the absolute offset
+ // can be exactly divided into chunks of the size of the
+ // casted-pointee type. If so, create a new ElementRegion with
+ // the pointee-cast type as the new ElementType and the index
+ // being the offset divded by the chunk size. If not, create
+ // a new ElementRegion at offset 0 off the raw offset region.
+ //
+ // (2b) If we don't a get a 'RegionRawOffset' after calling
+ // 'getAsRawOffset()', it means that we are at offset 0.
+ //
+ // FIXME: Handle symbolic raw offsets.
+
+ const ElementRegion *elementR = cast<ElementRegion>(R);
+ const RegionRawOffset &rawOff = elementR->getAsArrayOffset();
+ const MemRegion *baseR = rawOff.getRegion();
+
+ // If we cannot compute a raw offset, throw up our hands and return
+ // a NULL MemRegion*.
+ if (!baseR)
+ return NULL;
+
+ CharUnits off = CharUnits::fromQuantity(rawOff.getByteOffset());
+
+ if (off.isZero()) {
+ // Edge case: we are at 0 bytes off the beginning of baseR. We
+ // check to see if type we are casting to is the same as the base
+ // region. If so, just return the base region.
+ if (const TypedRegion *TR = dyn_cast<TypedRegion>(baseR)) {
+ QualType ObjTy = Ctx.getCanonicalType(TR->getValueType());
+ QualType CanonPointeeTy = Ctx.getCanonicalType(PointeeTy);
+ if (CanonPointeeTy == ObjTy)
+ return baseR;
+ }
+
+ // Otherwise, create a new ElementRegion at offset 0.
+ return MakeElementRegion(baseR, PointeeTy);
+ }
+
+ // We have a non-zero offset from the base region. We want to determine
+ // if the offset can be evenly divided by sizeof(PointeeTy). If so,
+ // we create an ElementRegion whose index is that value. Otherwise, we
+ // create two ElementRegions, one that reflects a raw offset and the other
+ // that reflects the cast.
+
+ // Compute the index for the new ElementRegion.
+ int64_t newIndex = 0;
+ const MemRegion *newSuperR = 0;
+
+ // We can only compute sizeof(PointeeTy) if it is a complete type.
+ if (IsCompleteType(Ctx, PointeeTy)) {
+ // Compute the size in **bytes**.
+ CharUnits pointeeTySize = Ctx.getTypeSizeInChars(PointeeTy);
+ if (!pointeeTySize.isZero()) {
+ // Is the offset a multiple of the size? If so, we can layer the
+ // ElementRegion (with elementType == PointeeTy) directly on top of
+ // the base region.
+ if (off % pointeeTySize == 0) {
+ newIndex = off / pointeeTySize;
+ newSuperR = baseR;
+ }
+ }
+ }
+
+ if (!newSuperR) {
+ // Create an intermediate ElementRegion to represent the raw byte.
+ // This will be the super region of the final ElementRegion.
+ newSuperR = MakeElementRegion(baseR, Ctx.CharTy, off.getQuantity());
+ }
+
+ return MakeElementRegion(newSuperR, PointeeTy, newIndex);
+ }
+ }
+
+ assert(0 && "unreachable");
+ return 0;
+}
+
+
+/// CastRetrievedVal - Used by subclasses of StoreManager to implement
+/// implicit casts that arise from loads from regions that are reinterpreted
+/// as another region.
+SVal StoreManager::CastRetrievedVal(SVal V, const TypedRegion *R,
+ QualType castTy, bool performTestOnly) {
+
+ if (castTy.isNull())
+ return V;
+
+ ASTContext &Ctx = svalBuilder.getContext();
+
+ if (performTestOnly) {
+ // Automatically translate references to pointers.
+ QualType T = R->getValueType();
+ if (const ReferenceType *RT = T->getAs<ReferenceType>())
+ T = Ctx.getPointerType(RT->getPointeeType());
+
+ assert(svalBuilder.getContext().hasSameUnqualifiedType(castTy, T));
+ return V;
+ }
+
+ if (const Loc *L = dyn_cast<Loc>(&V))
+ return svalBuilder.evalCastL(*L, castTy);
+ else if (const NonLoc *NL = dyn_cast<NonLoc>(&V))
+ return svalBuilder.evalCastNL(*NL, castTy);
+
+ return V;
+}
+
+SVal StoreManager::getLValueFieldOrIvar(const Decl* D, SVal Base) {
+ if (Base.isUnknownOrUndef())
+ return Base;
+
+ Loc BaseL = cast<Loc>(Base);
+ const MemRegion* BaseR = 0;
+
+ switch (BaseL.getSubKind()) {
+ case loc::MemRegionKind:
+ BaseR = cast<loc::MemRegionVal>(BaseL).getRegion();
+ break;
+
+ case loc::GotoLabelKind:
+ // These are anormal cases. Flag an undefined value.
+ return UndefinedVal();
+
+ case loc::ConcreteIntKind:
+ // While these seem funny, this can happen through casts.
+ // FIXME: What we should return is the field offset. For example,
+ // add the field offset to the integer value. That way funny things
+ // like this work properly: &(((struct foo *) 0xa)->f)
+ return Base;
+
+ default:
+ assert(0 && "Unhandled Base.");
+ return Base;
+ }
+
+ // NOTE: We must have this check first because ObjCIvarDecl is a subclass
+ // of FieldDecl.
+ if (const ObjCIvarDecl *ID = dyn_cast<ObjCIvarDecl>(D))
+ return loc::MemRegionVal(MRMgr.getObjCIvarRegion(ID, BaseR));
+
+ return loc::MemRegionVal(MRMgr.getFieldRegion(cast<FieldDecl>(D), BaseR));
+}
+
+SVal StoreManager::getLValueElement(QualType elementType, NonLoc Offset,
+ SVal Base) {
+
+ // If the base is an unknown or undefined value, just return it back.
+ // FIXME: For absolute pointer addresses, we just return that value back as
+ // well, although in reality we should return the offset added to that
+ // value.
+ if (Base.isUnknownOrUndef() || isa<loc::ConcreteInt>(Base))
+ return Base;
+
+ const MemRegion* BaseRegion = cast<loc::MemRegionVal>(Base).getRegion();
+
+ // Pointer of any type can be cast and used as array base.
+ const ElementRegion *ElemR = dyn_cast<ElementRegion>(BaseRegion);
+
+ // Convert the offset to the appropriate size and signedness.
+ Offset = cast<NonLoc>(svalBuilder.convertToArrayIndex(Offset));
+
+ if (!ElemR) {
+ //
+ // If the base region is not an ElementRegion, create one.
+ // This can happen in the following example:
+ //
+ // char *p = __builtin_alloc(10);
+ // p[1] = 8;
+ //
+ // Observe that 'p' binds to an AllocaRegion.
+ //
+ return loc::MemRegionVal(MRMgr.getElementRegion(elementType, Offset,
+ BaseRegion, Ctx));
+ }
+
+ SVal BaseIdx = ElemR->getIndex();
+
+ if (!isa<nonloc::ConcreteInt>(BaseIdx))
+ return UnknownVal();
+
+ const llvm::APSInt& BaseIdxI = cast<nonloc::ConcreteInt>(BaseIdx).getValue();
+
+ // Only allow non-integer offsets if the base region has no offset itself.
+ // FIXME: This is a somewhat arbitrary restriction. We should be using
+ // SValBuilder here to add the two offsets without checking their types.
+ if (!isa<nonloc::ConcreteInt>(Offset)) {
+ if (isa<ElementRegion>(BaseRegion->StripCasts()))
+ return UnknownVal();
+
+ return loc::MemRegionVal(MRMgr.getElementRegion(elementType, Offset,
+ ElemR->getSuperRegion(),
+ Ctx));
+ }
+
+ const llvm::APSInt& OffI = cast<nonloc::ConcreteInt>(Offset).getValue();
+ assert(BaseIdxI.isSigned());
+
+ // Compute the new index.
+ nonloc::ConcreteInt NewIdx(svalBuilder.getBasicValueFactory().getValue(BaseIdxI +
+ OffI));
+
+ // Construct the new ElementRegion.
+ const MemRegion *ArrayR = ElemR->getSuperRegion();
+ return loc::MemRegionVal(MRMgr.getElementRegion(elementType, NewIdx, ArrayR,
+ Ctx));
+}