2652 lines
97 KiB
C++
2652 lines
97 KiB
C++
//== RegionStore.cpp - Field-sensitive store model --------------*- C++ -*--==//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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//
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// This file defines a basic region store model. In this model, we do have field
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// sensitivity. But we assume nothing about the heap shape. So recursive data
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// structures are largely ignored. Basically we do 1-limiting analysis.
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// Parameter pointers are assumed with no aliasing. Pointee objects of
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// parameters are created lazily.
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//
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//===----------------------------------------------------------------------===//
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#include "clang/AST/Attr.h"
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#include "clang/AST/CharUnits.h"
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#include "clang/ASTMatchers/ASTMatchFinder.h"
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#include "clang/Analysis/Analyses/LiveVariables.h"
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#include "clang/Analysis/AnalysisDeclContext.h"
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#include "clang/Basic/JsonSupport.h"
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#include "clang/Basic/TargetInfo.h"
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#include "clang/StaticAnalyzer/Core/PathSensitive/AnalysisManager.h"
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#include "clang/StaticAnalyzer/Core/PathSensitive/CallEvent.h"
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#include "clang/StaticAnalyzer/Core/PathSensitive/DynamicSize.h"
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#include "clang/StaticAnalyzer/Core/PathSensitive/MemRegion.h"
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#include "clang/StaticAnalyzer/Core/PathSensitive/ProgramState.h"
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#include "clang/StaticAnalyzer/Core/PathSensitive/ProgramStateTrait.h"
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#include "clang/StaticAnalyzer/Core/PathSensitive/SubEngine.h"
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#include "llvm/ADT/ImmutableMap.h"
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#include "llvm/ADT/Optional.h"
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#include "llvm/Support/raw_ostream.h"
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#include <utility>
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using namespace clang;
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using namespace ento;
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//===----------------------------------------------------------------------===//
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// Representation of binding keys.
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//===----------------------------------------------------------------------===//
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namespace {
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class BindingKey {
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public:
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enum Kind { Default = 0x0, Direct = 0x1 };
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private:
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enum { Symbolic = 0x2 };
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llvm::PointerIntPair<const MemRegion *, 2> P;
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uint64_t Data;
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/// Create a key for a binding to region \p r, which has a symbolic offset
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/// from region \p Base.
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explicit BindingKey(const SubRegion *r, const SubRegion *Base, Kind k)
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: P(r, k | Symbolic), Data(reinterpret_cast<uintptr_t>(Base)) {
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assert(r && Base && "Must have known regions.");
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assert(getConcreteOffsetRegion() == Base && "Failed to store base region");
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}
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/// Create a key for a binding at \p offset from base region \p r.
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explicit BindingKey(const MemRegion *r, uint64_t offset, Kind k)
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: P(r, k), Data(offset) {
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assert(r && "Must have known regions.");
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assert(getOffset() == offset && "Failed to store offset");
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assert((r == r->getBaseRegion() || isa<ObjCIvarRegion>(r) ||
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isa <CXXDerivedObjectRegion>(r)) &&
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"Not a base");
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}
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public:
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bool isDirect() const { return P.getInt() & Direct; }
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bool hasSymbolicOffset() const { return P.getInt() & Symbolic; }
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const MemRegion *getRegion() const { return P.getPointer(); }
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uint64_t getOffset() const {
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assert(!hasSymbolicOffset());
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return Data;
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}
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const SubRegion *getConcreteOffsetRegion() const {
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assert(hasSymbolicOffset());
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return reinterpret_cast<const SubRegion *>(static_cast<uintptr_t>(Data));
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}
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const MemRegion *getBaseRegion() const {
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if (hasSymbolicOffset())
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return getConcreteOffsetRegion()->getBaseRegion();
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return getRegion()->getBaseRegion();
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}
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void Profile(llvm::FoldingSetNodeID& ID) const {
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ID.AddPointer(P.getOpaqueValue());
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ID.AddInteger(Data);
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}
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static BindingKey Make(const MemRegion *R, Kind k);
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bool operator<(const BindingKey &X) const {
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if (P.getOpaqueValue() < X.P.getOpaqueValue())
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return true;
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if (P.getOpaqueValue() > X.P.getOpaqueValue())
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return false;
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return Data < X.Data;
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}
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bool operator==(const BindingKey &X) const {
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return P.getOpaqueValue() == X.P.getOpaqueValue() &&
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Data == X.Data;
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}
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LLVM_DUMP_METHOD void dump() const;
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};
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} // end anonymous namespace
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BindingKey BindingKey::Make(const MemRegion *R, Kind k) {
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const RegionOffset &RO = R->getAsOffset();
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if (RO.hasSymbolicOffset())
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return BindingKey(cast<SubRegion>(R), cast<SubRegion>(RO.getRegion()), k);
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return BindingKey(RO.getRegion(), RO.getOffset(), k);
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}
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namespace llvm {
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static inline raw_ostream &operator<<(raw_ostream &Out, BindingKey K) {
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Out << "\"kind\": \"" << (K.isDirect() ? "Direct" : "Default")
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<< "\", \"offset\": ";
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if (!K.hasSymbolicOffset())
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Out << K.getOffset();
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else
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Out << "null";
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return Out;
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}
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} // namespace llvm
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#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
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void BindingKey::dump() const { llvm::errs() << *this; }
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#endif
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//===----------------------------------------------------------------------===//
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// Actual Store type.
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//===----------------------------------------------------------------------===//
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typedef llvm::ImmutableMap<BindingKey, SVal> ClusterBindings;
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typedef llvm::ImmutableMapRef<BindingKey, SVal> ClusterBindingsRef;
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typedef std::pair<BindingKey, SVal> BindingPair;
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typedef llvm::ImmutableMap<const MemRegion *, ClusterBindings>
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RegionBindings;
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namespace {
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class RegionBindingsRef : public llvm::ImmutableMapRef<const MemRegion *,
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ClusterBindings> {
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ClusterBindings::Factory *CBFactory;
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// This flag indicates whether the current bindings are within the analysis
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// that has started from main(). It affects how we perform loads from
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// global variables that have initializers: if we have observed the
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// program execution from the start and we know that these variables
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// have not been overwritten yet, we can be sure that their initializers
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// are still relevant. This flag never gets changed when the bindings are
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// updated, so it could potentially be moved into RegionStoreManager
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// (as if it's the same bindings but a different loading procedure)
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// however that would have made the manager needlessly stateful.
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bool IsMainAnalysis;
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public:
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typedef llvm::ImmutableMapRef<const MemRegion *, ClusterBindings>
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ParentTy;
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RegionBindingsRef(ClusterBindings::Factory &CBFactory,
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const RegionBindings::TreeTy *T,
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RegionBindings::TreeTy::Factory *F,
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bool IsMainAnalysis)
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: llvm::ImmutableMapRef<const MemRegion *, ClusterBindings>(T, F),
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CBFactory(&CBFactory), IsMainAnalysis(IsMainAnalysis) {}
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RegionBindingsRef(const ParentTy &P,
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ClusterBindings::Factory &CBFactory,
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bool IsMainAnalysis)
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: llvm::ImmutableMapRef<const MemRegion *, ClusterBindings>(P),
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CBFactory(&CBFactory), IsMainAnalysis(IsMainAnalysis) {}
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RegionBindingsRef add(key_type_ref K, data_type_ref D) const {
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return RegionBindingsRef(static_cast<const ParentTy *>(this)->add(K, D),
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*CBFactory, IsMainAnalysis);
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}
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RegionBindingsRef remove(key_type_ref K) const {
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return RegionBindingsRef(static_cast<const ParentTy *>(this)->remove(K),
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*CBFactory, IsMainAnalysis);
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}
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RegionBindingsRef addBinding(BindingKey K, SVal V) const;
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RegionBindingsRef addBinding(const MemRegion *R,
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BindingKey::Kind k, SVal V) const;
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const SVal *lookup(BindingKey K) const;
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const SVal *lookup(const MemRegion *R, BindingKey::Kind k) const;
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using llvm::ImmutableMapRef<const MemRegion *, ClusterBindings>::lookup;
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RegionBindingsRef removeBinding(BindingKey K);
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RegionBindingsRef removeBinding(const MemRegion *R,
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BindingKey::Kind k);
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RegionBindingsRef removeBinding(const MemRegion *R) {
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return removeBinding(R, BindingKey::Direct).
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removeBinding(R, BindingKey::Default);
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}
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Optional<SVal> getDirectBinding(const MemRegion *R) const;
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/// getDefaultBinding - Returns an SVal* representing an optional default
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/// binding associated with a region and its subregions.
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Optional<SVal> getDefaultBinding(const MemRegion *R) const;
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/// Return the internal tree as a Store.
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Store asStore() const {
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llvm::PointerIntPair<Store, 1, bool> Ptr = {
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asImmutableMap().getRootWithoutRetain(), IsMainAnalysis};
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return reinterpret_cast<Store>(Ptr.getOpaqueValue());
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}
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bool isMainAnalysis() const {
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return IsMainAnalysis;
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}
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void printJson(raw_ostream &Out, const char *NL = "\n",
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unsigned int Space = 0, bool IsDot = false) const {
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for (iterator I = begin(); I != end(); ++I) {
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// TODO: We might need a .printJson for I.getKey() as well.
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Indent(Out, Space, IsDot)
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<< "{ \"cluster\": \"" << I.getKey() << "\", \"pointer\": \""
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<< (const void *)I.getKey() << "\", \"items\": [" << NL;
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++Space;
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const ClusterBindings &CB = I.getData();
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for (ClusterBindings::iterator CI = CB.begin(); CI != CB.end(); ++CI) {
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Indent(Out, Space, IsDot) << "{ " << CI.getKey() << ", \"value\": ";
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CI.getData().printJson(Out, /*AddQuotes=*/true);
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Out << " }";
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if (std::next(CI) != CB.end())
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Out << ',';
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Out << NL;
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}
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--Space;
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Indent(Out, Space, IsDot) << "]}";
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if (std::next(I) != end())
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Out << ',';
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Out << NL;
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}
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}
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LLVM_DUMP_METHOD void dump() const { printJson(llvm::errs()); }
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};
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} // end anonymous namespace
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typedef const RegionBindingsRef& RegionBindingsConstRef;
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Optional<SVal> RegionBindingsRef::getDirectBinding(const MemRegion *R) const {
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return Optional<SVal>::create(lookup(R, BindingKey::Direct));
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}
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Optional<SVal> RegionBindingsRef::getDefaultBinding(const MemRegion *R) const {
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return Optional<SVal>::create(lookup(R, BindingKey::Default));
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}
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RegionBindingsRef RegionBindingsRef::addBinding(BindingKey K, SVal V) const {
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const MemRegion *Base = K.getBaseRegion();
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const ClusterBindings *ExistingCluster = lookup(Base);
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ClusterBindings Cluster =
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(ExistingCluster ? *ExistingCluster : CBFactory->getEmptyMap());
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ClusterBindings NewCluster = CBFactory->add(Cluster, K, V);
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return add(Base, NewCluster);
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}
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RegionBindingsRef RegionBindingsRef::addBinding(const MemRegion *R,
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BindingKey::Kind k,
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SVal V) const {
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return addBinding(BindingKey::Make(R, k), V);
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}
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const SVal *RegionBindingsRef::lookup(BindingKey K) const {
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const ClusterBindings *Cluster = lookup(K.getBaseRegion());
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if (!Cluster)
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return nullptr;
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return Cluster->lookup(K);
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}
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const SVal *RegionBindingsRef::lookup(const MemRegion *R,
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BindingKey::Kind k) const {
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return lookup(BindingKey::Make(R, k));
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}
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RegionBindingsRef RegionBindingsRef::removeBinding(BindingKey K) {
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const MemRegion *Base = K.getBaseRegion();
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const ClusterBindings *Cluster = lookup(Base);
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if (!Cluster)
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return *this;
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ClusterBindings NewCluster = CBFactory->remove(*Cluster, K);
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if (NewCluster.isEmpty())
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return remove(Base);
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return add(Base, NewCluster);
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}
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RegionBindingsRef RegionBindingsRef::removeBinding(const MemRegion *R,
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BindingKey::Kind k){
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return removeBinding(BindingKey::Make(R, k));
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}
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//===----------------------------------------------------------------------===//
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// Fine-grained control of RegionStoreManager.
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//===----------------------------------------------------------------------===//
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namespace {
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struct minimal_features_tag {};
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struct maximal_features_tag {};
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class RegionStoreFeatures {
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bool SupportsFields;
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public:
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RegionStoreFeatures(minimal_features_tag) :
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SupportsFields(false) {}
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RegionStoreFeatures(maximal_features_tag) :
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SupportsFields(true) {}
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void enableFields(bool t) { SupportsFields = t; }
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bool supportsFields() const { return SupportsFields; }
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};
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}
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//===----------------------------------------------------------------------===//
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// Main RegionStore logic.
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//===----------------------------------------------------------------------===//
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namespace {
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class InvalidateRegionsWorker;
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class RegionStoreManager : public StoreManager {
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public:
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const RegionStoreFeatures Features;
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RegionBindings::Factory RBFactory;
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mutable ClusterBindings::Factory CBFactory;
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typedef std::vector<SVal> SValListTy;
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private:
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typedef llvm::DenseMap<const LazyCompoundValData *,
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SValListTy> LazyBindingsMapTy;
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LazyBindingsMapTy LazyBindingsMap;
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/// The largest number of fields a struct can have and still be
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/// considered "small".
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///
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/// This is currently used to decide whether or not it is worth "forcing" a
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/// LazyCompoundVal on bind.
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///
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/// This is controlled by 'region-store-small-struct-limit' option.
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/// To disable all small-struct-dependent behavior, set the option to "0".
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unsigned SmallStructLimit;
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/// A helper used to populate the work list with the given set of
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/// regions.
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void populateWorkList(InvalidateRegionsWorker &W,
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ArrayRef<SVal> Values,
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InvalidatedRegions *TopLevelRegions);
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public:
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RegionStoreManager(ProgramStateManager& mgr, const RegionStoreFeatures &f)
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: StoreManager(mgr), Features(f),
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RBFactory(mgr.getAllocator()), CBFactory(mgr.getAllocator()),
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SmallStructLimit(0) {
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SubEngine &Eng = StateMgr.getOwningEngine();
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AnalyzerOptions &Options = Eng.getAnalysisManager().options;
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SmallStructLimit = Options.RegionStoreSmallStructLimit;
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}
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/// setImplicitDefaultValue - Set the default binding for the provided
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/// MemRegion to the value implicitly defined for compound literals when
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/// the value is not specified.
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RegionBindingsRef setImplicitDefaultValue(RegionBindingsConstRef B,
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const MemRegion *R, QualType T);
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/// ArrayToPointer - Emulates the "decay" of an array to a pointer
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/// type. 'Array' represents the lvalue of the array being decayed
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/// to a pointer, and the returned SVal represents the decayed
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/// version of that lvalue (i.e., a pointer to the first element of
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/// the array). This is called by ExprEngine when evaluating
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/// casts from arrays to pointers.
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SVal ArrayToPointer(Loc Array, QualType ElementTy) override;
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/// Creates the Store that correctly represents memory contents before
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/// the beginning of the analysis of the given top-level stack frame.
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StoreRef getInitialStore(const LocationContext *InitLoc) override {
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bool IsMainAnalysis = false;
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if (const auto *FD = dyn_cast<FunctionDecl>(InitLoc->getDecl()))
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IsMainAnalysis = FD->isMain() && !Ctx.getLangOpts().CPlusPlus;
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return StoreRef(RegionBindingsRef(
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RegionBindingsRef::ParentTy(RBFactory.getEmptyMap(), RBFactory),
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CBFactory, IsMainAnalysis).asStore(), *this);
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}
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//===-------------------------------------------------------------------===//
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// Binding values to regions.
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//===-------------------------------------------------------------------===//
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RegionBindingsRef invalidateGlobalRegion(MemRegion::Kind K,
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const Expr *Ex,
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unsigned Count,
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const LocationContext *LCtx,
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RegionBindingsRef B,
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InvalidatedRegions *Invalidated);
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StoreRef invalidateRegions(Store store,
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ArrayRef<SVal> Values,
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const Expr *E, unsigned Count,
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const LocationContext *LCtx,
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const CallEvent *Call,
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InvalidatedSymbols &IS,
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RegionAndSymbolInvalidationTraits &ITraits,
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InvalidatedRegions *Invalidated,
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InvalidatedRegions *InvalidatedTopLevel) override;
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bool scanReachableSymbols(Store S, const MemRegion *R,
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ScanReachableSymbols &Callbacks) override;
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RegionBindingsRef removeSubRegionBindings(RegionBindingsConstRef B,
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const SubRegion *R);
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public: // Part of public interface to class.
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StoreRef Bind(Store store, Loc LV, SVal V) override {
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return StoreRef(bind(getRegionBindings(store), LV, V).asStore(), *this);
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}
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RegionBindingsRef bind(RegionBindingsConstRef B, Loc LV, SVal V);
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// BindDefaultInitial is only used to initialize a region with
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// a default value.
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StoreRef BindDefaultInitial(Store store, const MemRegion *R,
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SVal V) override {
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RegionBindingsRef B = getRegionBindings(store);
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// Use other APIs when you have to wipe the region that was initialized
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// earlier.
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assert(!(B.getDefaultBinding(R) || B.getDirectBinding(R)) &&
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"Double initialization!");
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B = B.addBinding(BindingKey::Make(R, BindingKey::Default), V);
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return StoreRef(B.asImmutableMap().getRootWithoutRetain(), *this);
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}
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// BindDefaultZero is used for zeroing constructors that may accidentally
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// overwrite existing bindings.
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StoreRef BindDefaultZero(Store store, const MemRegion *R) override {
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// FIXME: The offsets of empty bases can be tricky because of
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// of the so called "empty base class optimization".
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// If a base class has been optimized out
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// we should not try to create a binding, otherwise we should.
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// Unfortunately, at the moment ASTRecordLayout doesn't expose
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// the actual sizes of the empty bases
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// and trying to infer them from offsets/alignments
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// seems to be error-prone and non-trivial because of the trailing padding.
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// As a temporary mitigation we don't create bindings for empty bases.
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if (const auto *BR = dyn_cast<CXXBaseObjectRegion>(R))
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if (BR->getDecl()->isEmpty())
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return StoreRef(store, *this);
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RegionBindingsRef B = getRegionBindings(store);
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SVal V = svalBuilder.makeZeroVal(Ctx.CharTy);
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B = removeSubRegionBindings(B, cast<SubRegion>(R));
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B = B.addBinding(BindingKey::Make(R, BindingKey::Default), V);
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return StoreRef(B.asImmutableMap().getRootWithoutRetain(), *this);
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}
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/// Attempt to extract the fields of \p LCV and bind them to the struct region
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/// \p R.
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///
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/// This path is used when it seems advantageous to "force" loading the values
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/// within a LazyCompoundVal to bind memberwise to the struct region, rather
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/// than using a Default binding at the base of the entire region. This is a
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/// heuristic attempting to avoid building long chains of LazyCompoundVals.
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///
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/// \returns The updated store bindings, or \c None if binding non-lazily
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/// would be too expensive.
|
|
Optional<RegionBindingsRef> tryBindSmallStruct(RegionBindingsConstRef B,
|
|
const TypedValueRegion *R,
|
|
const RecordDecl *RD,
|
|
nonloc::LazyCompoundVal LCV);
|
|
|
|
/// BindStruct - Bind a compound value to a structure.
|
|
RegionBindingsRef bindStruct(RegionBindingsConstRef B,
|
|
const TypedValueRegion* R, SVal V);
|
|
|
|
/// BindVector - Bind a compound value to a vector.
|
|
RegionBindingsRef bindVector(RegionBindingsConstRef B,
|
|
const TypedValueRegion* R, SVal V);
|
|
|
|
RegionBindingsRef bindArray(RegionBindingsConstRef B,
|
|
const TypedValueRegion* R,
|
|
SVal V);
|
|
|
|
/// Clears out all bindings in the given region and assigns a new value
|
|
/// as a Default binding.
|
|
RegionBindingsRef bindAggregate(RegionBindingsConstRef B,
|
|
const TypedRegion *R,
|
|
SVal DefaultVal);
|
|
|
|
/// Create a new store with the specified binding removed.
|
|
/// \param ST the original store, that is the basis for the new store.
|
|
/// \param L the location whose binding should be removed.
|
|
StoreRef killBinding(Store ST, Loc L) override;
|
|
|
|
void incrementReferenceCount(Store store) override {
|
|
getRegionBindings(store).manualRetain();
|
|
}
|
|
|
|
/// If the StoreManager supports it, decrement the reference count of
|
|
/// the specified Store object. If the reference count hits 0, the memory
|
|
/// associated with the object is recycled.
|
|
void decrementReferenceCount(Store store) override {
|
|
getRegionBindings(store).manualRelease();
|
|
}
|
|
|
|
bool includedInBindings(Store store, const MemRegion *region) const override;
|
|
|
|
/// Return the value bound to specified location in a given state.
|
|
///
|
|
/// The high level logic for this method is this:
|
|
/// getBinding (L)
|
|
/// if L has binding
|
|
/// return L's binding
|
|
/// else if L is in killset
|
|
/// return unknown
|
|
/// else
|
|
/// if L is on stack or heap
|
|
/// return undefined
|
|
/// else
|
|
/// return symbolic
|
|
SVal getBinding(Store S, Loc L, QualType T) override {
|
|
return getBinding(getRegionBindings(S), L, T);
|
|
}
|
|
|
|
Optional<SVal> getDefaultBinding(Store S, const MemRegion *R) override {
|
|
RegionBindingsRef B = getRegionBindings(S);
|
|
// Default bindings are always applied over a base region so look up the
|
|
// base region's default binding, otherwise the lookup will fail when R
|
|
// is at an offset from R->getBaseRegion().
|
|
return B.getDefaultBinding(R->getBaseRegion());
|
|
}
|
|
|
|
SVal getBinding(RegionBindingsConstRef B, Loc L, QualType T = QualType());
|
|
|
|
SVal getBindingForElement(RegionBindingsConstRef B, const ElementRegion *R);
|
|
|
|
SVal getBindingForField(RegionBindingsConstRef B, const FieldRegion *R);
|
|
|
|
SVal getBindingForObjCIvar(RegionBindingsConstRef B, const ObjCIvarRegion *R);
|
|
|
|
SVal getBindingForVar(RegionBindingsConstRef B, const VarRegion *R);
|
|
|
|
SVal getBindingForLazySymbol(const TypedValueRegion *R);
|
|
|
|
SVal getBindingForFieldOrElementCommon(RegionBindingsConstRef B,
|
|
const TypedValueRegion *R,
|
|
QualType Ty);
|
|
|
|
SVal getLazyBinding(const SubRegion *LazyBindingRegion,
|
|
RegionBindingsRef LazyBinding);
|
|
|
|
/// Get bindings for the values in a struct and return a CompoundVal, used
|
|
/// when doing struct copy:
|
|
/// struct s x, y;
|
|
/// x = y;
|
|
/// y's value is retrieved by this method.
|
|
SVal getBindingForStruct(RegionBindingsConstRef B, const TypedValueRegion *R);
|
|
SVal getBindingForArray(RegionBindingsConstRef B, const TypedValueRegion *R);
|
|
NonLoc createLazyBinding(RegionBindingsConstRef B, const TypedValueRegion *R);
|
|
|
|
/// Used to lazily generate derived symbols for bindings that are defined
|
|
/// implicitly by default bindings in a super region.
|
|
///
|
|
/// Note that callers may need to specially handle LazyCompoundVals, which
|
|
/// are returned as is in case the caller needs to treat them differently.
|
|
Optional<SVal> getBindingForDerivedDefaultValue(RegionBindingsConstRef B,
|
|
const MemRegion *superR,
|
|
const TypedValueRegion *R,
|
|
QualType Ty);
|
|
|
|
/// Get the state and region whose binding this region \p R corresponds to.
|
|
///
|
|
/// If there is no lazy binding for \p R, the returned value will have a null
|
|
/// \c second. Note that a null pointer can represents a valid Store.
|
|
std::pair<Store, const SubRegion *>
|
|
findLazyBinding(RegionBindingsConstRef B, const SubRegion *R,
|
|
const SubRegion *originalRegion);
|
|
|
|
/// Returns the cached set of interesting SVals contained within a lazy
|
|
/// binding.
|
|
///
|
|
/// The precise value of "interesting" is determined for the purposes of
|
|
/// RegionStore's internal analysis. It must always contain all regions and
|
|
/// symbols, but may omit constants and other kinds of SVal.
|
|
const SValListTy &getInterestingValues(nonloc::LazyCompoundVal LCV);
|
|
|
|
//===------------------------------------------------------------------===//
|
|
// State pruning.
|
|
//===------------------------------------------------------------------===//
|
|
|
|
/// removeDeadBindings - Scans the RegionStore of 'state' for dead values.
|
|
/// It returns a new Store with these values removed.
|
|
StoreRef removeDeadBindings(Store store, const StackFrameContext *LCtx,
|
|
SymbolReaper& SymReaper) override;
|
|
|
|
//===------------------------------------------------------------------===//
|
|
// Utility methods.
|
|
//===------------------------------------------------------------------===//
|
|
|
|
RegionBindingsRef getRegionBindings(Store store) const {
|
|
llvm::PointerIntPair<Store, 1, bool> Ptr;
|
|
Ptr.setFromOpaqueValue(const_cast<void *>(store));
|
|
return RegionBindingsRef(
|
|
CBFactory,
|
|
static_cast<const RegionBindings::TreeTy *>(Ptr.getPointer()),
|
|
RBFactory.getTreeFactory(),
|
|
Ptr.getInt());
|
|
}
|
|
|
|
void printJson(raw_ostream &Out, Store S, const char *NL = "\n",
|
|
unsigned int Space = 0, bool IsDot = false) const override;
|
|
|
|
void iterBindings(Store store, BindingsHandler& f) override {
|
|
RegionBindingsRef B = getRegionBindings(store);
|
|
for (RegionBindingsRef::iterator I = B.begin(), E = B.end(); I != E; ++I) {
|
|
const ClusterBindings &Cluster = I.getData();
|
|
for (ClusterBindings::iterator CI = Cluster.begin(), CE = Cluster.end();
|
|
CI != CE; ++CI) {
|
|
const BindingKey &K = CI.getKey();
|
|
if (!K.isDirect())
|
|
continue;
|
|
if (const SubRegion *R = dyn_cast<SubRegion>(K.getRegion())) {
|
|
// FIXME: Possibly incorporate the offset?
|
|
if (!f.HandleBinding(*this, store, R, CI.getData()))
|
|
return;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
};
|
|
|
|
} // end anonymous namespace
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
// RegionStore creation.
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
std::unique_ptr<StoreManager>
|
|
ento::CreateRegionStoreManager(ProgramStateManager &StMgr) {
|
|
RegionStoreFeatures F = maximal_features_tag();
|
|
return std::make_unique<RegionStoreManager>(StMgr, F);
|
|
}
|
|
|
|
std::unique_ptr<StoreManager>
|
|
ento::CreateFieldsOnlyRegionStoreManager(ProgramStateManager &StMgr) {
|
|
RegionStoreFeatures F = minimal_features_tag();
|
|
F.enableFields(true);
|
|
return std::make_unique<RegionStoreManager>(StMgr, F);
|
|
}
|
|
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
// Region Cluster analysis.
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
namespace {
|
|
/// Used to determine which global regions are automatically included in the
|
|
/// initial worklist of a ClusterAnalysis.
|
|
enum GlobalsFilterKind {
|
|
/// Don't include any global regions.
|
|
GFK_None,
|
|
/// Only include system globals.
|
|
GFK_SystemOnly,
|
|
/// Include all global regions.
|
|
GFK_All
|
|
};
|
|
|
|
template <typename DERIVED>
|
|
class ClusterAnalysis {
|
|
protected:
|
|
typedef llvm::DenseMap<const MemRegion *, const ClusterBindings *> ClusterMap;
|
|
typedef const MemRegion * WorkListElement;
|
|
typedef SmallVector<WorkListElement, 10> WorkList;
|
|
|
|
llvm::SmallPtrSet<const ClusterBindings *, 16> Visited;
|
|
|
|
WorkList WL;
|
|
|
|
RegionStoreManager &RM;
|
|
ASTContext &Ctx;
|
|
SValBuilder &svalBuilder;
|
|
|
|
RegionBindingsRef B;
|
|
|
|
|
|
protected:
|
|
const ClusterBindings *getCluster(const MemRegion *R) {
|
|
return B.lookup(R);
|
|
}
|
|
|
|
/// Returns true if all clusters in the given memspace should be initially
|
|
/// included in the cluster analysis. Subclasses may provide their
|
|
/// own implementation.
|
|
bool includeEntireMemorySpace(const MemRegion *Base) {
|
|
return false;
|
|
}
|
|
|
|
public:
|
|
ClusterAnalysis(RegionStoreManager &rm, ProgramStateManager &StateMgr,
|
|
RegionBindingsRef b)
|
|
: RM(rm), Ctx(StateMgr.getContext()),
|
|
svalBuilder(StateMgr.getSValBuilder()), B(std::move(b)) {}
|
|
|
|
RegionBindingsRef getRegionBindings() const { return B; }
|
|
|
|
bool isVisited(const MemRegion *R) {
|
|
return Visited.count(getCluster(R));
|
|
}
|
|
|
|
void GenerateClusters() {
|
|
// Scan the entire set of bindings and record the region clusters.
|
|
for (RegionBindingsRef::iterator RI = B.begin(), RE = B.end();
|
|
RI != RE; ++RI){
|
|
const MemRegion *Base = RI.getKey();
|
|
|
|
const ClusterBindings &Cluster = RI.getData();
|
|
assert(!Cluster.isEmpty() && "Empty clusters should be removed");
|
|
static_cast<DERIVED*>(this)->VisitAddedToCluster(Base, Cluster);
|
|
|
|
// If the base's memspace should be entirely invalidated, add the cluster
|
|
// to the workspace up front.
|
|
if (static_cast<DERIVED*>(this)->includeEntireMemorySpace(Base))
|
|
AddToWorkList(WorkListElement(Base), &Cluster);
|
|
}
|
|
}
|
|
|
|
bool AddToWorkList(WorkListElement E, const ClusterBindings *C) {
|
|
if (C && !Visited.insert(C).second)
|
|
return false;
|
|
WL.push_back(E);
|
|
return true;
|
|
}
|
|
|
|
bool AddToWorkList(const MemRegion *R) {
|
|
return static_cast<DERIVED*>(this)->AddToWorkList(R);
|
|
}
|
|
|
|
void RunWorkList() {
|
|
while (!WL.empty()) {
|
|
WorkListElement E = WL.pop_back_val();
|
|
const MemRegion *BaseR = E;
|
|
|
|
static_cast<DERIVED*>(this)->VisitCluster(BaseR, getCluster(BaseR));
|
|
}
|
|
}
|
|
|
|
void VisitAddedToCluster(const MemRegion *baseR, const ClusterBindings &C) {}
|
|
void VisitCluster(const MemRegion *baseR, const ClusterBindings *C) {}
|
|
|
|
void VisitCluster(const MemRegion *BaseR, const ClusterBindings *C,
|
|
bool Flag) {
|
|
static_cast<DERIVED*>(this)->VisitCluster(BaseR, C);
|
|
}
|
|
};
|
|
}
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
// Binding invalidation.
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
bool RegionStoreManager::scanReachableSymbols(Store S, const MemRegion *R,
|
|
ScanReachableSymbols &Callbacks) {
|
|
assert(R == R->getBaseRegion() && "Should only be called for base regions");
|
|
RegionBindingsRef B = getRegionBindings(S);
|
|
const ClusterBindings *Cluster = B.lookup(R);
|
|
|
|
if (!Cluster)
|
|
return true;
|
|
|
|
for (ClusterBindings::iterator RI = Cluster->begin(), RE = Cluster->end();
|
|
RI != RE; ++RI) {
|
|
if (!Callbacks.scan(RI.getData()))
|
|
return false;
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
static inline bool isUnionField(const FieldRegion *FR) {
|
|
return FR->getDecl()->getParent()->isUnion();
|
|
}
|
|
|
|
typedef SmallVector<const FieldDecl *, 8> FieldVector;
|
|
|
|
static void getSymbolicOffsetFields(BindingKey K, FieldVector &Fields) {
|
|
assert(K.hasSymbolicOffset() && "Not implemented for concrete offset keys");
|
|
|
|
const MemRegion *Base = K.getConcreteOffsetRegion();
|
|
const MemRegion *R = K.getRegion();
|
|
|
|
while (R != Base) {
|
|
if (const FieldRegion *FR = dyn_cast<FieldRegion>(R))
|
|
if (!isUnionField(FR))
|
|
Fields.push_back(FR->getDecl());
|
|
|
|
R = cast<SubRegion>(R)->getSuperRegion();
|
|
}
|
|
}
|
|
|
|
static bool isCompatibleWithFields(BindingKey K, const FieldVector &Fields) {
|
|
assert(K.hasSymbolicOffset() && "Not implemented for concrete offset keys");
|
|
|
|
if (Fields.empty())
|
|
return true;
|
|
|
|
FieldVector FieldsInBindingKey;
|
|
getSymbolicOffsetFields(K, FieldsInBindingKey);
|
|
|
|
ptrdiff_t Delta = FieldsInBindingKey.size() - Fields.size();
|
|
if (Delta >= 0)
|
|
return std::equal(FieldsInBindingKey.begin() + Delta,
|
|
FieldsInBindingKey.end(),
|
|
Fields.begin());
|
|
else
|
|
return std::equal(FieldsInBindingKey.begin(), FieldsInBindingKey.end(),
|
|
Fields.begin() - Delta);
|
|
}
|
|
|
|
/// Collects all bindings in \p Cluster that may refer to bindings within
|
|
/// \p Top.
|
|
///
|
|
/// Each binding is a pair whose \c first is the key (a BindingKey) and whose
|
|
/// \c second is the value (an SVal).
|
|
///
|
|
/// The \p IncludeAllDefaultBindings parameter specifies whether to include
|
|
/// default bindings that may extend beyond \p Top itself, e.g. if \p Top is
|
|
/// an aggregate within a larger aggregate with a default binding.
|
|
static void
|
|
collectSubRegionBindings(SmallVectorImpl<BindingPair> &Bindings,
|
|
SValBuilder &SVB, const ClusterBindings &Cluster,
|
|
const SubRegion *Top, BindingKey TopKey,
|
|
bool IncludeAllDefaultBindings) {
|
|
FieldVector FieldsInSymbolicSubregions;
|
|
if (TopKey.hasSymbolicOffset()) {
|
|
getSymbolicOffsetFields(TopKey, FieldsInSymbolicSubregions);
|
|
Top = TopKey.getConcreteOffsetRegion();
|
|
TopKey = BindingKey::Make(Top, BindingKey::Default);
|
|
}
|
|
|
|
// Find the length (in bits) of the region being invalidated.
|
|
uint64_t Length = UINT64_MAX;
|
|
SVal Extent = Top->getMemRegionManager().getStaticSize(Top, SVB);
|
|
if (Optional<nonloc::ConcreteInt> ExtentCI =
|
|
Extent.getAs<nonloc::ConcreteInt>()) {
|
|
const llvm::APSInt &ExtentInt = ExtentCI->getValue();
|
|
assert(ExtentInt.isNonNegative() || ExtentInt.isUnsigned());
|
|
// Extents are in bytes but region offsets are in bits. Be careful!
|
|
Length = ExtentInt.getLimitedValue() * SVB.getContext().getCharWidth();
|
|
} else if (const FieldRegion *FR = dyn_cast<FieldRegion>(Top)) {
|
|
if (FR->getDecl()->isBitField())
|
|
Length = FR->getDecl()->getBitWidthValue(SVB.getContext());
|
|
}
|
|
|
|
for (ClusterBindings::iterator I = Cluster.begin(), E = Cluster.end();
|
|
I != E; ++I) {
|
|
BindingKey NextKey = I.getKey();
|
|
if (NextKey.getRegion() == TopKey.getRegion()) {
|
|
// FIXME: This doesn't catch the case where we're really invalidating a
|
|
// region with a symbolic offset. Example:
|
|
// R: points[i].y
|
|
// Next: points[0].x
|
|
|
|
if (NextKey.getOffset() > TopKey.getOffset() &&
|
|
NextKey.getOffset() - TopKey.getOffset() < Length) {
|
|
// Case 1: The next binding is inside the region we're invalidating.
|
|
// Include it.
|
|
Bindings.push_back(*I);
|
|
|
|
} else if (NextKey.getOffset() == TopKey.getOffset()) {
|
|
// Case 2: The next binding is at the same offset as the region we're
|
|
// invalidating. In this case, we need to leave default bindings alone,
|
|
// since they may be providing a default value for a regions beyond what
|
|
// we're invalidating.
|
|
// FIXME: This is probably incorrect; consider invalidating an outer
|
|
// struct whose first field is bound to a LazyCompoundVal.
|
|
if (IncludeAllDefaultBindings || NextKey.isDirect())
|
|
Bindings.push_back(*I);
|
|
}
|
|
|
|
} else if (NextKey.hasSymbolicOffset()) {
|
|
const MemRegion *Base = NextKey.getConcreteOffsetRegion();
|
|
if (Top->isSubRegionOf(Base) && Top != Base) {
|
|
// Case 3: The next key is symbolic and we just changed something within
|
|
// its concrete region. We don't know if the binding is still valid, so
|
|
// we'll be conservative and include it.
|
|
if (IncludeAllDefaultBindings || NextKey.isDirect())
|
|
if (isCompatibleWithFields(NextKey, FieldsInSymbolicSubregions))
|
|
Bindings.push_back(*I);
|
|
} else if (const SubRegion *BaseSR = dyn_cast<SubRegion>(Base)) {
|
|
// Case 4: The next key is symbolic, but we changed a known
|
|
// super-region. In this case the binding is certainly included.
|
|
if (BaseSR->isSubRegionOf(Top))
|
|
if (isCompatibleWithFields(NextKey, FieldsInSymbolicSubregions))
|
|
Bindings.push_back(*I);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
static void
|
|
collectSubRegionBindings(SmallVectorImpl<BindingPair> &Bindings,
|
|
SValBuilder &SVB, const ClusterBindings &Cluster,
|
|
const SubRegion *Top, bool IncludeAllDefaultBindings) {
|
|
collectSubRegionBindings(Bindings, SVB, Cluster, Top,
|
|
BindingKey::Make(Top, BindingKey::Default),
|
|
IncludeAllDefaultBindings);
|
|
}
|
|
|
|
RegionBindingsRef
|
|
RegionStoreManager::removeSubRegionBindings(RegionBindingsConstRef B,
|
|
const SubRegion *Top) {
|
|
BindingKey TopKey = BindingKey::Make(Top, BindingKey::Default);
|
|
const MemRegion *ClusterHead = TopKey.getBaseRegion();
|
|
|
|
if (Top == ClusterHead) {
|
|
// We can remove an entire cluster's bindings all in one go.
|
|
return B.remove(Top);
|
|
}
|
|
|
|
const ClusterBindings *Cluster = B.lookup(ClusterHead);
|
|
if (!Cluster) {
|
|
// If we're invalidating a region with a symbolic offset, we need to make
|
|
// sure we don't treat the base region as uninitialized anymore.
|
|
if (TopKey.hasSymbolicOffset()) {
|
|
const SubRegion *Concrete = TopKey.getConcreteOffsetRegion();
|
|
return B.addBinding(Concrete, BindingKey::Default, UnknownVal());
|
|
}
|
|
return B;
|
|
}
|
|
|
|
SmallVector<BindingPair, 32> Bindings;
|
|
collectSubRegionBindings(Bindings, svalBuilder, *Cluster, Top, TopKey,
|
|
/*IncludeAllDefaultBindings=*/false);
|
|
|
|
ClusterBindingsRef Result(*Cluster, CBFactory);
|
|
for (SmallVectorImpl<BindingPair>::const_iterator I = Bindings.begin(),
|
|
E = Bindings.end();
|
|
I != E; ++I)
|
|
Result = Result.remove(I->first);
|
|
|
|
// If we're invalidating a region with a symbolic offset, we need to make sure
|
|
// we don't treat the base region as uninitialized anymore.
|
|
// FIXME: This isn't very precise; see the example in
|
|
// collectSubRegionBindings.
|
|
if (TopKey.hasSymbolicOffset()) {
|
|
const SubRegion *Concrete = TopKey.getConcreteOffsetRegion();
|
|
Result = Result.add(BindingKey::Make(Concrete, BindingKey::Default),
|
|
UnknownVal());
|
|
}
|
|
|
|
if (Result.isEmpty())
|
|
return B.remove(ClusterHead);
|
|
return B.add(ClusterHead, Result.asImmutableMap());
|
|
}
|
|
|
|
namespace {
|
|
class InvalidateRegionsWorker : public ClusterAnalysis<InvalidateRegionsWorker>
|
|
{
|
|
const Expr *Ex;
|
|
unsigned Count;
|
|
const LocationContext *LCtx;
|
|
InvalidatedSymbols &IS;
|
|
RegionAndSymbolInvalidationTraits &ITraits;
|
|
StoreManager::InvalidatedRegions *Regions;
|
|
GlobalsFilterKind GlobalsFilter;
|
|
public:
|
|
InvalidateRegionsWorker(RegionStoreManager &rm,
|
|
ProgramStateManager &stateMgr,
|
|
RegionBindingsRef b,
|
|
const Expr *ex, unsigned count,
|
|
const LocationContext *lctx,
|
|
InvalidatedSymbols &is,
|
|
RegionAndSymbolInvalidationTraits &ITraitsIn,
|
|
StoreManager::InvalidatedRegions *r,
|
|
GlobalsFilterKind GFK)
|
|
: ClusterAnalysis<InvalidateRegionsWorker>(rm, stateMgr, b),
|
|
Ex(ex), Count(count), LCtx(lctx), IS(is), ITraits(ITraitsIn), Regions(r),
|
|
GlobalsFilter(GFK) {}
|
|
|
|
void VisitCluster(const MemRegion *baseR, const ClusterBindings *C);
|
|
void VisitBinding(SVal V);
|
|
|
|
using ClusterAnalysis::AddToWorkList;
|
|
|
|
bool AddToWorkList(const MemRegion *R);
|
|
|
|
/// Returns true if all clusters in the memory space for \p Base should be
|
|
/// be invalidated.
|
|
bool includeEntireMemorySpace(const MemRegion *Base);
|
|
|
|
/// Returns true if the memory space of the given region is one of the global
|
|
/// regions specially included at the start of invalidation.
|
|
bool isInitiallyIncludedGlobalRegion(const MemRegion *R);
|
|
};
|
|
}
|
|
|
|
bool InvalidateRegionsWorker::AddToWorkList(const MemRegion *R) {
|
|
bool doNotInvalidateSuperRegion = ITraits.hasTrait(
|
|
R, RegionAndSymbolInvalidationTraits::TK_DoNotInvalidateSuperRegion);
|
|
const MemRegion *BaseR = doNotInvalidateSuperRegion ? R : R->getBaseRegion();
|
|
return AddToWorkList(WorkListElement(BaseR), getCluster(BaseR));
|
|
}
|
|
|
|
void InvalidateRegionsWorker::VisitBinding(SVal V) {
|
|
// A symbol? Mark it touched by the invalidation.
|
|
if (SymbolRef Sym = V.getAsSymbol())
|
|
IS.insert(Sym);
|
|
|
|
if (const MemRegion *R = V.getAsRegion()) {
|
|
AddToWorkList(R);
|
|
return;
|
|
}
|
|
|
|
// Is it a LazyCompoundVal? All references get invalidated as well.
|
|
if (Optional<nonloc::LazyCompoundVal> LCS =
|
|
V.getAs<nonloc::LazyCompoundVal>()) {
|
|
|
|
const RegionStoreManager::SValListTy &Vals = RM.getInterestingValues(*LCS);
|
|
|
|
for (RegionStoreManager::SValListTy::const_iterator I = Vals.begin(),
|
|
E = Vals.end();
|
|
I != E; ++I)
|
|
VisitBinding(*I);
|
|
|
|
return;
|
|
}
|
|
}
|
|
|
|
void InvalidateRegionsWorker::VisitCluster(const MemRegion *baseR,
|
|
const ClusterBindings *C) {
|
|
|
|
bool PreserveRegionsContents =
|
|
ITraits.hasTrait(baseR,
|
|
RegionAndSymbolInvalidationTraits::TK_PreserveContents);
|
|
|
|
if (C) {
|
|
for (ClusterBindings::iterator I = C->begin(), E = C->end(); I != E; ++I)
|
|
VisitBinding(I.getData());
|
|
|
|
// Invalidate regions contents.
|
|
if (!PreserveRegionsContents)
|
|
B = B.remove(baseR);
|
|
}
|
|
|
|
if (const auto *TO = dyn_cast<TypedValueRegion>(baseR)) {
|
|
if (const auto *RD = TO->getValueType()->getAsCXXRecordDecl()) {
|
|
|
|
// Lambdas can affect all static local variables without explicitly
|
|
// capturing those.
|
|
// We invalidate all static locals referenced inside the lambda body.
|
|
if (RD->isLambda() && RD->getLambdaCallOperator()->getBody()) {
|
|
using namespace ast_matchers;
|
|
|
|
const char *DeclBind = "DeclBind";
|
|
StatementMatcher RefToStatic = stmt(hasDescendant(declRefExpr(
|
|
to(varDecl(hasStaticStorageDuration()).bind(DeclBind)))));
|
|
auto Matches =
|
|
match(RefToStatic, *RD->getLambdaCallOperator()->getBody(),
|
|
RD->getASTContext());
|
|
|
|
for (BoundNodes &Match : Matches) {
|
|
auto *VD = Match.getNodeAs<VarDecl>(DeclBind);
|
|
const VarRegion *ToInvalidate =
|
|
RM.getRegionManager().getVarRegion(VD, LCtx);
|
|
AddToWorkList(ToInvalidate);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
// BlockDataRegion? If so, invalidate captured variables that are passed
|
|
// by reference.
|
|
if (const BlockDataRegion *BR = dyn_cast<BlockDataRegion>(baseR)) {
|
|
for (BlockDataRegion::referenced_vars_iterator
|
|
BI = BR->referenced_vars_begin(), BE = BR->referenced_vars_end() ;
|
|
BI != BE; ++BI) {
|
|
const VarRegion *VR = BI.getCapturedRegion();
|
|
const VarDecl *VD = VR->getDecl();
|
|
if (VD->hasAttr<BlocksAttr>() || !VD->hasLocalStorage()) {
|
|
AddToWorkList(VR);
|
|
}
|
|
else if (Loc::isLocType(VR->getValueType())) {
|
|
// Map the current bindings to a Store to retrieve the value
|
|
// of the binding. If that binding itself is a region, we should
|
|
// invalidate that region. This is because a block may capture
|
|
// a pointer value, but the thing pointed by that pointer may
|
|
// get invalidated.
|
|
SVal V = RM.getBinding(B, loc::MemRegionVal(VR));
|
|
if (Optional<Loc> L = V.getAs<Loc>()) {
|
|
if (const MemRegion *LR = L->getAsRegion())
|
|
AddToWorkList(LR);
|
|
}
|
|
}
|
|
}
|
|
return;
|
|
}
|
|
|
|
// Symbolic region?
|
|
if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(baseR))
|
|
IS.insert(SR->getSymbol());
|
|
|
|
// Nothing else should be done in the case when we preserve regions context.
|
|
if (PreserveRegionsContents)
|
|
return;
|
|
|
|
// Otherwise, we have a normal data region. Record that we touched the region.
|
|
if (Regions)
|
|
Regions->push_back(baseR);
|
|
|
|
if (isa<AllocaRegion>(baseR) || isa<SymbolicRegion>(baseR)) {
|
|
// Invalidate the region by setting its default value to
|
|
// conjured symbol. The type of the symbol is irrelevant.
|
|
DefinedOrUnknownSVal V =
|
|
svalBuilder.conjureSymbolVal(baseR, Ex, LCtx, Ctx.IntTy, Count);
|
|
B = B.addBinding(baseR, BindingKey::Default, V);
|
|
return;
|
|
}
|
|
|
|
if (!baseR->isBoundable())
|
|
return;
|
|
|
|
const TypedValueRegion *TR = cast<TypedValueRegion>(baseR);
|
|
QualType T = TR->getValueType();
|
|
|
|
if (isInitiallyIncludedGlobalRegion(baseR)) {
|
|
// If the region is a global and we are invalidating all globals,
|
|
// erasing the entry is good enough. This causes all globals to be lazily
|
|
// symbolicated from the same base symbol.
|
|
return;
|
|
}
|
|
|
|
if (T->isRecordType()) {
|
|
// Invalidate the region by setting its default value to
|
|
// conjured symbol. The type of the symbol is irrelevant.
|
|
DefinedOrUnknownSVal V = svalBuilder.conjureSymbolVal(baseR, Ex, LCtx,
|
|
Ctx.IntTy, Count);
|
|
B = B.addBinding(baseR, BindingKey::Default, V);
|
|
return;
|
|
}
|
|
|
|
if (const ArrayType *AT = Ctx.getAsArrayType(T)) {
|
|
bool doNotInvalidateSuperRegion = ITraits.hasTrait(
|
|
baseR,
|
|
RegionAndSymbolInvalidationTraits::TK_DoNotInvalidateSuperRegion);
|
|
|
|
if (doNotInvalidateSuperRegion) {
|
|
// We are not doing blank invalidation of the whole array region so we
|
|
// have to manually invalidate each elements.
|
|
Optional<uint64_t> NumElements;
|
|
|
|
// Compute lower and upper offsets for region within array.
|
|
if (const ConstantArrayType *CAT = dyn_cast<ConstantArrayType>(AT))
|
|
NumElements = CAT->getSize().getZExtValue();
|
|
if (!NumElements) // We are not dealing with a constant size array
|
|
goto conjure_default;
|
|
QualType ElementTy = AT->getElementType();
|
|
uint64_t ElemSize = Ctx.getTypeSize(ElementTy);
|
|
const RegionOffset &RO = baseR->getAsOffset();
|
|
const MemRegion *SuperR = baseR->getBaseRegion();
|
|
if (RO.hasSymbolicOffset()) {
|
|
// If base region has a symbolic offset,
|
|
// we revert to invalidating the super region.
|
|
if (SuperR)
|
|
AddToWorkList(SuperR);
|
|
goto conjure_default;
|
|
}
|
|
|
|
uint64_t LowerOffset = RO.getOffset();
|
|
uint64_t UpperOffset = LowerOffset + *NumElements * ElemSize;
|
|
bool UpperOverflow = UpperOffset < LowerOffset;
|
|
|
|
// Invalidate regions which are within array boundaries,
|
|
// or have a symbolic offset.
|
|
if (!SuperR)
|
|
goto conjure_default;
|
|
|
|
const ClusterBindings *C = B.lookup(SuperR);
|
|
if (!C)
|
|
goto conjure_default;
|
|
|
|
for (ClusterBindings::iterator I = C->begin(), E = C->end(); I != E;
|
|
++I) {
|
|
const BindingKey &BK = I.getKey();
|
|
Optional<uint64_t> ROffset =
|
|
BK.hasSymbolicOffset() ? Optional<uint64_t>() : BK.getOffset();
|
|
|
|
// Check offset is not symbolic and within array's boundaries.
|
|
// Handles arrays of 0 elements and of 0-sized elements as well.
|
|
if (!ROffset ||
|
|
((*ROffset >= LowerOffset && *ROffset < UpperOffset) ||
|
|
(UpperOverflow &&
|
|
(*ROffset >= LowerOffset || *ROffset < UpperOffset)) ||
|
|
(LowerOffset == UpperOffset && *ROffset == LowerOffset))) {
|
|
B = B.removeBinding(I.getKey());
|
|
// Bound symbolic regions need to be invalidated for dead symbol
|
|
// detection.
|
|
SVal V = I.getData();
|
|
const MemRegion *R = V.getAsRegion();
|
|
if (R && isa<SymbolicRegion>(R))
|
|
VisitBinding(V);
|
|
}
|
|
}
|
|
}
|
|
conjure_default:
|
|
// Set the default value of the array to conjured symbol.
|
|
DefinedOrUnknownSVal V =
|
|
svalBuilder.conjureSymbolVal(baseR, Ex, LCtx,
|
|
AT->getElementType(), Count);
|
|
B = B.addBinding(baseR, BindingKey::Default, V);
|
|
return;
|
|
}
|
|
|
|
DefinedOrUnknownSVal V = svalBuilder.conjureSymbolVal(baseR, Ex, LCtx,
|
|
T,Count);
|
|
assert(SymbolManager::canSymbolicate(T) || V.isUnknown());
|
|
B = B.addBinding(baseR, BindingKey::Direct, V);
|
|
}
|
|
|
|
bool InvalidateRegionsWorker::isInitiallyIncludedGlobalRegion(
|
|
const MemRegion *R) {
|
|
switch (GlobalsFilter) {
|
|
case GFK_None:
|
|
return false;
|
|
case GFK_SystemOnly:
|
|
return isa<GlobalSystemSpaceRegion>(R->getMemorySpace());
|
|
case GFK_All:
|
|
return isa<NonStaticGlobalSpaceRegion>(R->getMemorySpace());
|
|
}
|
|
|
|
llvm_unreachable("unknown globals filter");
|
|
}
|
|
|
|
bool InvalidateRegionsWorker::includeEntireMemorySpace(const MemRegion *Base) {
|
|
if (isInitiallyIncludedGlobalRegion(Base))
|
|
return true;
|
|
|
|
const MemSpaceRegion *MemSpace = Base->getMemorySpace();
|
|
return ITraits.hasTrait(MemSpace,
|
|
RegionAndSymbolInvalidationTraits::TK_EntireMemSpace);
|
|
}
|
|
|
|
RegionBindingsRef
|
|
RegionStoreManager::invalidateGlobalRegion(MemRegion::Kind K,
|
|
const Expr *Ex,
|
|
unsigned Count,
|
|
const LocationContext *LCtx,
|
|
RegionBindingsRef B,
|
|
InvalidatedRegions *Invalidated) {
|
|
// Bind the globals memory space to a new symbol that we will use to derive
|
|
// the bindings for all globals.
|
|
const GlobalsSpaceRegion *GS = MRMgr.getGlobalsRegion(K);
|
|
SVal V = svalBuilder.conjureSymbolVal(/* symbolTag = */ (const void*) GS, Ex, LCtx,
|
|
/* type does not matter */ Ctx.IntTy,
|
|
Count);
|
|
|
|
B = B.removeBinding(GS)
|
|
.addBinding(BindingKey::Make(GS, BindingKey::Default), V);
|
|
|
|
// Even if there are no bindings in the global scope, we still need to
|
|
// record that we touched it.
|
|
if (Invalidated)
|
|
Invalidated->push_back(GS);
|
|
|
|
return B;
|
|
}
|
|
|
|
void RegionStoreManager::populateWorkList(InvalidateRegionsWorker &W,
|
|
ArrayRef<SVal> Values,
|
|
InvalidatedRegions *TopLevelRegions) {
|
|
for (ArrayRef<SVal>::iterator I = Values.begin(),
|
|
E = Values.end(); I != E; ++I) {
|
|
SVal V = *I;
|
|
if (Optional<nonloc::LazyCompoundVal> LCS =
|
|
V.getAs<nonloc::LazyCompoundVal>()) {
|
|
|
|
const SValListTy &Vals = getInterestingValues(*LCS);
|
|
|
|
for (SValListTy::const_iterator I = Vals.begin(),
|
|
E = Vals.end(); I != E; ++I) {
|
|
// Note: the last argument is false here because these are
|
|
// non-top-level regions.
|
|
if (const MemRegion *R = (*I).getAsRegion())
|
|
W.AddToWorkList(R);
|
|
}
|
|
continue;
|
|
}
|
|
|
|
if (const MemRegion *R = V.getAsRegion()) {
|
|
if (TopLevelRegions)
|
|
TopLevelRegions->push_back(R);
|
|
W.AddToWorkList(R);
|
|
continue;
|
|
}
|
|
}
|
|
}
|
|
|
|
StoreRef
|
|
RegionStoreManager::invalidateRegions(Store store,
|
|
ArrayRef<SVal> Values,
|
|
const Expr *Ex, unsigned Count,
|
|
const LocationContext *LCtx,
|
|
const CallEvent *Call,
|
|
InvalidatedSymbols &IS,
|
|
RegionAndSymbolInvalidationTraits &ITraits,
|
|
InvalidatedRegions *TopLevelRegions,
|
|
InvalidatedRegions *Invalidated) {
|
|
GlobalsFilterKind GlobalsFilter;
|
|
if (Call) {
|
|
if (Call->isInSystemHeader())
|
|
GlobalsFilter = GFK_SystemOnly;
|
|
else
|
|
GlobalsFilter = GFK_All;
|
|
} else {
|
|
GlobalsFilter = GFK_None;
|
|
}
|
|
|
|
RegionBindingsRef B = getRegionBindings(store);
|
|
InvalidateRegionsWorker W(*this, StateMgr, B, Ex, Count, LCtx, IS, ITraits,
|
|
Invalidated, GlobalsFilter);
|
|
|
|
// Scan the bindings and generate the clusters.
|
|
W.GenerateClusters();
|
|
|
|
// Add the regions to the worklist.
|
|
populateWorkList(W, Values, TopLevelRegions);
|
|
|
|
W.RunWorkList();
|
|
|
|
// Return the new bindings.
|
|
B = W.getRegionBindings();
|
|
|
|
// For calls, determine which global regions should be invalidated and
|
|
// invalidate them. (Note that function-static and immutable globals are never
|
|
// invalidated by this.)
|
|
// TODO: This could possibly be more precise with modules.
|
|
switch (GlobalsFilter) {
|
|
case GFK_All:
|
|
B = invalidateGlobalRegion(MemRegion::GlobalInternalSpaceRegionKind,
|
|
Ex, Count, LCtx, B, Invalidated);
|
|
LLVM_FALLTHROUGH;
|
|
case GFK_SystemOnly:
|
|
B = invalidateGlobalRegion(MemRegion::GlobalSystemSpaceRegionKind,
|
|
Ex, Count, LCtx, B, Invalidated);
|
|
LLVM_FALLTHROUGH;
|
|
case GFK_None:
|
|
break;
|
|
}
|
|
|
|
return StoreRef(B.asStore(), *this);
|
|
}
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
// Location and region casting.
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
/// ArrayToPointer - Emulates the "decay" of an array to a pointer
|
|
/// type. 'Array' represents the lvalue of the array being decayed
|
|
/// to a pointer, and the returned SVal represents the decayed
|
|
/// version of that lvalue (i.e., a pointer to the first element of
|
|
/// the array). This is called by ExprEngine when evaluating casts
|
|
/// from arrays to pointers.
|
|
SVal RegionStoreManager::ArrayToPointer(Loc Array, QualType T) {
|
|
if (Array.getAs<loc::ConcreteInt>())
|
|
return Array;
|
|
|
|
if (!Array.getAs<loc::MemRegionVal>())
|
|
return UnknownVal();
|
|
|
|
const SubRegion *R =
|
|
cast<SubRegion>(Array.castAs<loc::MemRegionVal>().getRegion());
|
|
NonLoc ZeroIdx = svalBuilder.makeZeroArrayIndex();
|
|
return loc::MemRegionVal(MRMgr.getElementRegion(T, ZeroIdx, R, Ctx));
|
|
}
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
// Loading values from regions.
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
SVal RegionStoreManager::getBinding(RegionBindingsConstRef B, Loc L, QualType T) {
|
|
assert(!L.getAs<UnknownVal>() && "location unknown");
|
|
assert(!L.getAs<UndefinedVal>() && "location undefined");
|
|
|
|
// For access to concrete addresses, return UnknownVal. Checks
|
|
// for null dereferences (and similar errors) are done by checkers, not
|
|
// the Store.
|
|
// FIXME: We can consider lazily symbolicating such memory, but we really
|
|
// should defer this when we can reason easily about symbolicating arrays
|
|
// of bytes.
|
|
if (L.getAs<loc::ConcreteInt>()) {
|
|
return UnknownVal();
|
|
}
|
|
if (!L.getAs<loc::MemRegionVal>()) {
|
|
return UnknownVal();
|
|
}
|
|
|
|
const MemRegion *MR = L.castAs<loc::MemRegionVal>().getRegion();
|
|
|
|
if (isa<BlockDataRegion>(MR)) {
|
|
return UnknownVal();
|
|
}
|
|
|
|
if (!isa<TypedValueRegion>(MR)) {
|
|
if (T.isNull()) {
|
|
if (const TypedRegion *TR = dyn_cast<TypedRegion>(MR))
|
|
T = TR->getLocationType()->getPointeeType();
|
|
else if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(MR))
|
|
T = SR->getSymbol()->getType()->getPointeeType();
|
|
}
|
|
assert(!T.isNull() && "Unable to auto-detect binding type!");
|
|
assert(!T->isVoidType() && "Attempting to dereference a void pointer!");
|
|
MR = GetElementZeroRegion(cast<SubRegion>(MR), T);
|
|
} else {
|
|
T = cast<TypedValueRegion>(MR)->getValueType();
|
|
}
|
|
|
|
// FIXME: Perhaps this method should just take a 'const MemRegion*' argument
|
|
// instead of 'Loc', and have the other Loc cases handled at a higher level.
|
|
const TypedValueRegion *R = cast<TypedValueRegion>(MR);
|
|
QualType RTy = R->getValueType();
|
|
|
|
// FIXME: we do not yet model the parts of a complex type, so treat the
|
|
// whole thing as "unknown".
|
|
if (RTy->isAnyComplexType())
|
|
return UnknownVal();
|
|
|
|
// FIXME: We should eventually handle funny addressing. e.g.:
|
|
//
|
|
// int x = ...;
|
|
// int *p = &x;
|
|
// char *q = (char*) p;
|
|
// char c = *q; // returns the first byte of 'x'.
|
|
//
|
|
// Such funny addressing will occur due to layering of regions.
|
|
if (RTy->isStructureOrClassType())
|
|
return getBindingForStruct(B, R);
|
|
|
|
// FIXME: Handle unions.
|
|
if (RTy->isUnionType())
|
|
return createLazyBinding(B, R);
|
|
|
|
if (RTy->isArrayType()) {
|
|
if (RTy->isConstantArrayType())
|
|
return getBindingForArray(B, R);
|
|
else
|
|
return UnknownVal();
|
|
}
|
|
|
|
// FIXME: handle Vector types.
|
|
if (RTy->isVectorType())
|
|
return UnknownVal();
|
|
|
|
if (const FieldRegion* FR = dyn_cast<FieldRegion>(R))
|
|
return CastRetrievedVal(getBindingForField(B, FR), FR, T);
|
|
|
|
if (const ElementRegion* ER = dyn_cast<ElementRegion>(R)) {
|
|
// FIXME: Here we actually perform an implicit conversion from the loaded
|
|
// value to the element type. Eventually we want to compose these values
|
|
// more intelligently. For example, an 'element' can encompass multiple
|
|
// bound regions (e.g., several bound bytes), or could be a subset of
|
|
// a larger value.
|
|
return CastRetrievedVal(getBindingForElement(B, ER), ER, T);
|
|
}
|
|
|
|
if (const ObjCIvarRegion *IVR = dyn_cast<ObjCIvarRegion>(R)) {
|
|
// FIXME: Here we actually perform an implicit conversion from the loaded
|
|
// value to the ivar type. What we should model is stores to ivars
|
|
// that blow past the extent of the ivar. If the address of the ivar is
|
|
// reinterpretted, it is possible we stored a different value that could
|
|
// fit within the ivar. Either we need to cast these when storing them
|
|
// or reinterpret them lazily (as we do here).
|
|
return CastRetrievedVal(getBindingForObjCIvar(B, IVR), IVR, T);
|
|
}
|
|
|
|
if (const VarRegion *VR = dyn_cast<VarRegion>(R)) {
|
|
// FIXME: Here we actually perform an implicit conversion from the loaded
|
|
// value to the variable type. What we should model is stores to variables
|
|
// that blow past the extent of the variable. If the address of the
|
|
// variable is reinterpretted, it is possible we stored a different value
|
|
// that could fit within the variable. Either we need to cast these when
|
|
// storing them or reinterpret them lazily (as we do here).
|
|
return CastRetrievedVal(getBindingForVar(B, VR), VR, T);
|
|
}
|
|
|
|
const SVal *V = B.lookup(R, BindingKey::Direct);
|
|
|
|
// Check if the region has a binding.
|
|
if (V)
|
|
return *V;
|
|
|
|
// The location does not have a bound value. This means that it has
|
|
// the value it had upon its creation and/or entry to the analyzed
|
|
// function/method. These are either symbolic values or 'undefined'.
|
|
if (R->hasStackNonParametersStorage()) {
|
|
// All stack variables are considered to have undefined values
|
|
// upon creation. All heap allocated blocks are considered to
|
|
// have undefined values as well unless they are explicitly bound
|
|
// to specific values.
|
|
return UndefinedVal();
|
|
}
|
|
|
|
// All other values are symbolic.
|
|
return svalBuilder.getRegionValueSymbolVal(R);
|
|
}
|
|
|
|
static QualType getUnderlyingType(const SubRegion *R) {
|
|
QualType RegionTy;
|
|
if (const TypedValueRegion *TVR = dyn_cast<TypedValueRegion>(R))
|
|
RegionTy = TVR->getValueType();
|
|
|
|
if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(R))
|
|
RegionTy = SR->getSymbol()->getType();
|
|
|
|
return RegionTy;
|
|
}
|
|
|
|
/// Checks to see if store \p B has a lazy binding for region \p R.
|
|
///
|
|
/// If \p AllowSubregionBindings is \c false, a lazy binding will be rejected
|
|
/// if there are additional bindings within \p R.
|
|
///
|
|
/// Note that unlike RegionStoreManager::findLazyBinding, this will not search
|
|
/// for lazy bindings for super-regions of \p R.
|
|
static Optional<nonloc::LazyCompoundVal>
|
|
getExistingLazyBinding(SValBuilder &SVB, RegionBindingsConstRef B,
|
|
const SubRegion *R, bool AllowSubregionBindings) {
|
|
Optional<SVal> V = B.getDefaultBinding(R);
|
|
if (!V)
|
|
return None;
|
|
|
|
Optional<nonloc::LazyCompoundVal> LCV = V->getAs<nonloc::LazyCompoundVal>();
|
|
if (!LCV)
|
|
return None;
|
|
|
|
// If the LCV is for a subregion, the types might not match, and we shouldn't
|
|
// reuse the binding.
|
|
QualType RegionTy = getUnderlyingType(R);
|
|
if (!RegionTy.isNull() &&
|
|
!RegionTy->isVoidPointerType()) {
|
|
QualType SourceRegionTy = LCV->getRegion()->getValueType();
|
|
if (!SVB.getContext().hasSameUnqualifiedType(RegionTy, SourceRegionTy))
|
|
return None;
|
|
}
|
|
|
|
if (!AllowSubregionBindings) {
|
|
// If there are any other bindings within this region, we shouldn't reuse
|
|
// the top-level binding.
|
|
SmallVector<BindingPair, 16> Bindings;
|
|
collectSubRegionBindings(Bindings, SVB, *B.lookup(R->getBaseRegion()), R,
|
|
/*IncludeAllDefaultBindings=*/true);
|
|
if (Bindings.size() > 1)
|
|
return None;
|
|
}
|
|
|
|
return *LCV;
|
|
}
|
|
|
|
|
|
std::pair<Store, const SubRegion *>
|
|
RegionStoreManager::findLazyBinding(RegionBindingsConstRef B,
|
|
const SubRegion *R,
|
|
const SubRegion *originalRegion) {
|
|
if (originalRegion != R) {
|
|
if (Optional<nonloc::LazyCompoundVal> V =
|
|
getExistingLazyBinding(svalBuilder, B, R, true))
|
|
return std::make_pair(V->getStore(), V->getRegion());
|
|
}
|
|
|
|
typedef std::pair<Store, const SubRegion *> StoreRegionPair;
|
|
StoreRegionPair Result = StoreRegionPair();
|
|
|
|
if (const ElementRegion *ER = dyn_cast<ElementRegion>(R)) {
|
|
Result = findLazyBinding(B, cast<SubRegion>(ER->getSuperRegion()),
|
|
originalRegion);
|
|
|
|
if (Result.second)
|
|
Result.second = MRMgr.getElementRegionWithSuper(ER, Result.second);
|
|
|
|
} else if (const FieldRegion *FR = dyn_cast<FieldRegion>(R)) {
|
|
Result = findLazyBinding(B, cast<SubRegion>(FR->getSuperRegion()),
|
|
originalRegion);
|
|
|
|
if (Result.second)
|
|
Result.second = MRMgr.getFieldRegionWithSuper(FR, Result.second);
|
|
|
|
} else if (const CXXBaseObjectRegion *BaseReg =
|
|
dyn_cast<CXXBaseObjectRegion>(R)) {
|
|
// C++ base object region is another kind of region that we should blast
|
|
// through to look for lazy compound value. It is like a field region.
|
|
Result = findLazyBinding(B, cast<SubRegion>(BaseReg->getSuperRegion()),
|
|
originalRegion);
|
|
|
|
if (Result.second)
|
|
Result.second = MRMgr.getCXXBaseObjectRegionWithSuper(BaseReg,
|
|
Result.second);
|
|
}
|
|
|
|
return Result;
|
|
}
|
|
|
|
SVal RegionStoreManager::getBindingForElement(RegionBindingsConstRef B,
|
|
const ElementRegion* R) {
|
|
// We do not currently model bindings of the CompoundLiteralregion.
|
|
if (isa<CompoundLiteralRegion>(R->getBaseRegion()))
|
|
return UnknownVal();
|
|
|
|
// Check if the region has a binding.
|
|
if (const Optional<SVal> &V = B.getDirectBinding(R))
|
|
return *V;
|
|
|
|
const MemRegion* superR = R->getSuperRegion();
|
|
|
|
// Check if the region is an element region of a string literal.
|
|
if (const StringRegion *StrR = dyn_cast<StringRegion>(superR)) {
|
|
// FIXME: Handle loads from strings where the literal is treated as
|
|
// an integer, e.g., *((unsigned int*)"hello")
|
|
QualType T = Ctx.getAsArrayType(StrR->getValueType())->getElementType();
|
|
if (!Ctx.hasSameUnqualifiedType(T, R->getElementType()))
|
|
return UnknownVal();
|
|
|
|
const StringLiteral *Str = StrR->getStringLiteral();
|
|
SVal Idx = R->getIndex();
|
|
if (Optional<nonloc::ConcreteInt> CI = Idx.getAs<nonloc::ConcreteInt>()) {
|
|
int64_t i = CI->getValue().getSExtValue();
|
|
// Abort on string underrun. This can be possible by arbitrary
|
|
// clients of getBindingForElement().
|
|
if (i < 0)
|
|
return UndefinedVal();
|
|
int64_t length = Str->getLength();
|
|
// Technically, only i == length is guaranteed to be null.
|
|
// However, such overflows should be caught before reaching this point;
|
|
// the only time such an access would be made is if a string literal was
|
|
// used to initialize a larger array.
|
|
char c = (i >= length) ? '\0' : Str->getCodeUnit(i);
|
|
return svalBuilder.makeIntVal(c, T);
|
|
}
|
|
} else if (const VarRegion *VR = dyn_cast<VarRegion>(superR)) {
|
|
// Check if the containing array has an initialized value that we can trust.
|
|
// We can trust a const value or a value of a global initializer in main().
|
|
const VarDecl *VD = VR->getDecl();
|
|
if (VD->getType().isConstQualified() ||
|
|
R->getElementType().isConstQualified() ||
|
|
(B.isMainAnalysis() && VD->hasGlobalStorage())) {
|
|
if (const Expr *Init = VD->getAnyInitializer()) {
|
|
if (const auto *InitList = dyn_cast<InitListExpr>(Init)) {
|
|
// The array index has to be known.
|
|
if (auto CI = R->getIndex().getAs<nonloc::ConcreteInt>()) {
|
|
int64_t i = CI->getValue().getSExtValue();
|
|
// If it is known that the index is out of bounds, we can return
|
|
// an undefined value.
|
|
if (i < 0)
|
|
return UndefinedVal();
|
|
|
|
if (auto CAT = Ctx.getAsConstantArrayType(VD->getType()))
|
|
if (CAT->getSize().sle(i))
|
|
return UndefinedVal();
|
|
|
|
// If there is a list, but no init, it must be zero.
|
|
if (i >= InitList->getNumInits())
|
|
return svalBuilder.makeZeroVal(R->getElementType());
|
|
|
|
if (const Expr *ElemInit = InitList->getInit(i))
|
|
if (Optional<SVal> V = svalBuilder.getConstantVal(ElemInit))
|
|
return *V;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
// Check for loads from a code text region. For such loads, just give up.
|
|
if (isa<CodeTextRegion>(superR))
|
|
return UnknownVal();
|
|
|
|
// Handle the case where we are indexing into a larger scalar object.
|
|
// For example, this handles:
|
|
// int x = ...
|
|
// char *y = &x;
|
|
// return *y;
|
|
// FIXME: This is a hack, and doesn't do anything really intelligent yet.
|
|
const RegionRawOffset &O = R->getAsArrayOffset();
|
|
|
|
// If we cannot reason about the offset, return an unknown value.
|
|
if (!O.getRegion())
|
|
return UnknownVal();
|
|
|
|
if (const TypedValueRegion *baseR =
|
|
dyn_cast_or_null<TypedValueRegion>(O.getRegion())) {
|
|
QualType baseT = baseR->getValueType();
|
|
if (baseT->isScalarType()) {
|
|
QualType elemT = R->getElementType();
|
|
if (elemT->isScalarType()) {
|
|
if (Ctx.getTypeSizeInChars(baseT) >= Ctx.getTypeSizeInChars(elemT)) {
|
|
if (const Optional<SVal> &V = B.getDirectBinding(superR)) {
|
|
if (SymbolRef parentSym = V->getAsSymbol())
|
|
return svalBuilder.getDerivedRegionValueSymbolVal(parentSym, R);
|
|
|
|
if (V->isUnknownOrUndef())
|
|
return *V;
|
|
// Other cases: give up. We are indexing into a larger object
|
|
// that has some value, but we don't know how to handle that yet.
|
|
return UnknownVal();
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
return getBindingForFieldOrElementCommon(B, R, R->getElementType());
|
|
}
|
|
|
|
SVal RegionStoreManager::getBindingForField(RegionBindingsConstRef B,
|
|
const FieldRegion* R) {
|
|
|
|
// Check if the region has a binding.
|
|
if (const Optional<SVal> &V = B.getDirectBinding(R))
|
|
return *V;
|
|
|
|
// Is the field declared constant and has an in-class initializer?
|
|
const FieldDecl *FD = R->getDecl();
|
|
QualType Ty = FD->getType();
|
|
if (Ty.isConstQualified())
|
|
if (const Expr *Init = FD->getInClassInitializer())
|
|
if (Optional<SVal> V = svalBuilder.getConstantVal(Init))
|
|
return *V;
|
|
|
|
// If the containing record was initialized, try to get its constant value.
|
|
const MemRegion* superR = R->getSuperRegion();
|
|
if (const auto *VR = dyn_cast<VarRegion>(superR)) {
|
|
const VarDecl *VD = VR->getDecl();
|
|
QualType RecordVarTy = VD->getType();
|
|
unsigned Index = FD->getFieldIndex();
|
|
// Either the record variable or the field has an initializer that we can
|
|
// trust. We trust initializers of constants and, additionally, respect
|
|
// initializers of globals when analyzing main().
|
|
if (RecordVarTy.isConstQualified() || Ty.isConstQualified() ||
|
|
(B.isMainAnalysis() && VD->hasGlobalStorage()))
|
|
if (const Expr *Init = VD->getAnyInitializer())
|
|
if (const auto *InitList = dyn_cast<InitListExpr>(Init)) {
|
|
if (Index < InitList->getNumInits()) {
|
|
if (const Expr *FieldInit = InitList->getInit(Index))
|
|
if (Optional<SVal> V = svalBuilder.getConstantVal(FieldInit))
|
|
return *V;
|
|
} else {
|
|
return svalBuilder.makeZeroVal(Ty);
|
|
}
|
|
}
|
|
}
|
|
|
|
return getBindingForFieldOrElementCommon(B, R, Ty);
|
|
}
|
|
|
|
Optional<SVal>
|
|
RegionStoreManager::getBindingForDerivedDefaultValue(RegionBindingsConstRef B,
|
|
const MemRegion *superR,
|
|
const TypedValueRegion *R,
|
|
QualType Ty) {
|
|
|
|
if (const Optional<SVal> &D = B.getDefaultBinding(superR)) {
|
|
const SVal &val = D.getValue();
|
|
if (SymbolRef parentSym = val.getAsSymbol())
|
|
return svalBuilder.getDerivedRegionValueSymbolVal(parentSym, R);
|
|
|
|
if (val.isZeroConstant())
|
|
return svalBuilder.makeZeroVal(Ty);
|
|
|
|
if (val.isUnknownOrUndef())
|
|
return val;
|
|
|
|
// Lazy bindings are usually handled through getExistingLazyBinding().
|
|
// We should unify these two code paths at some point.
|
|
if (val.getAs<nonloc::LazyCompoundVal>() ||
|
|
val.getAs<nonloc::CompoundVal>())
|
|
return val;
|
|
|
|
llvm_unreachable("Unknown default value");
|
|
}
|
|
|
|
return None;
|
|
}
|
|
|
|
SVal RegionStoreManager::getLazyBinding(const SubRegion *LazyBindingRegion,
|
|
RegionBindingsRef LazyBinding) {
|
|
SVal Result;
|
|
if (const ElementRegion *ER = dyn_cast<ElementRegion>(LazyBindingRegion))
|
|
Result = getBindingForElement(LazyBinding, ER);
|
|
else
|
|
Result = getBindingForField(LazyBinding,
|
|
cast<FieldRegion>(LazyBindingRegion));
|
|
|
|
// FIXME: This is a hack to deal with RegionStore's inability to distinguish a
|
|
// default value for /part/ of an aggregate from a default value for the
|
|
// /entire/ aggregate. The most common case of this is when struct Outer
|
|
// has as its first member a struct Inner, which is copied in from a stack
|
|
// variable. In this case, even if the Outer's default value is symbolic, 0,
|
|
// or unknown, it gets overridden by the Inner's default value of undefined.
|
|
//
|
|
// This is a general problem -- if the Inner is zero-initialized, the Outer
|
|
// will now look zero-initialized. The proper way to solve this is with a
|
|
// new version of RegionStore that tracks the extent of a binding as well
|
|
// as the offset.
|
|
//
|
|
// This hack only takes care of the undefined case because that can very
|
|
// quickly result in a warning.
|
|
if (Result.isUndef())
|
|
Result = UnknownVal();
|
|
|
|
return Result;
|
|
}
|
|
|
|
SVal
|
|
RegionStoreManager::getBindingForFieldOrElementCommon(RegionBindingsConstRef B,
|
|
const TypedValueRegion *R,
|
|
QualType Ty) {
|
|
|
|
// At this point we have already checked in either getBindingForElement or
|
|
// getBindingForField if 'R' has a direct binding.
|
|
|
|
// Lazy binding?
|
|
Store lazyBindingStore = nullptr;
|
|
const SubRegion *lazyBindingRegion = nullptr;
|
|
std::tie(lazyBindingStore, lazyBindingRegion) = findLazyBinding(B, R, R);
|
|
if (lazyBindingRegion)
|
|
return getLazyBinding(lazyBindingRegion,
|
|
getRegionBindings(lazyBindingStore));
|
|
|
|
// Record whether or not we see a symbolic index. That can completely
|
|
// be out of scope of our lookup.
|
|
bool hasSymbolicIndex = false;
|
|
|
|
// FIXME: This is a hack to deal with RegionStore's inability to distinguish a
|
|
// default value for /part/ of an aggregate from a default value for the
|
|
// /entire/ aggregate. The most common case of this is when struct Outer
|
|
// has as its first member a struct Inner, which is copied in from a stack
|
|
// variable. In this case, even if the Outer's default value is symbolic, 0,
|
|
// or unknown, it gets overridden by the Inner's default value of undefined.
|
|
//
|
|
// This is a general problem -- if the Inner is zero-initialized, the Outer
|
|
// will now look zero-initialized. The proper way to solve this is with a
|
|
// new version of RegionStore that tracks the extent of a binding as well
|
|
// as the offset.
|
|
//
|
|
// This hack only takes care of the undefined case because that can very
|
|
// quickly result in a warning.
|
|
bool hasPartialLazyBinding = false;
|
|
|
|
const SubRegion *SR = R;
|
|
while (SR) {
|
|
const MemRegion *Base = SR->getSuperRegion();
|
|
if (Optional<SVal> D = getBindingForDerivedDefaultValue(B, Base, R, Ty)) {
|
|
if (D->getAs<nonloc::LazyCompoundVal>()) {
|
|
hasPartialLazyBinding = true;
|
|
break;
|
|
}
|
|
|
|
return *D;
|
|
}
|
|
|
|
if (const ElementRegion *ER = dyn_cast<ElementRegion>(Base)) {
|
|
NonLoc index = ER->getIndex();
|
|
if (!index.isConstant())
|
|
hasSymbolicIndex = true;
|
|
}
|
|
|
|
// If our super region is a field or element itself, walk up the region
|
|
// hierarchy to see if there is a default value installed in an ancestor.
|
|
SR = dyn_cast<SubRegion>(Base);
|
|
}
|
|
|
|
if (R->hasStackNonParametersStorage()) {
|
|
if (isa<ElementRegion>(R)) {
|
|
// Currently we don't reason specially about Clang-style vectors. Check
|
|
// if superR is a vector and if so return Unknown.
|
|
if (const TypedValueRegion *typedSuperR =
|
|
dyn_cast<TypedValueRegion>(R->getSuperRegion())) {
|
|
if (typedSuperR->getValueType()->isVectorType())
|
|
return UnknownVal();
|
|
}
|
|
}
|
|
|
|
// FIXME: We also need to take ElementRegions with symbolic indexes into
|
|
// account. This case handles both directly accessing an ElementRegion
|
|
// with a symbolic offset, but also fields within an element with
|
|
// a symbolic offset.
|
|
if (hasSymbolicIndex)
|
|
return UnknownVal();
|
|
|
|
// Additionally allow introspection of a block's internal layout.
|
|
if (!hasPartialLazyBinding && !isa<BlockDataRegion>(R->getBaseRegion()))
|
|
return UndefinedVal();
|
|
}
|
|
|
|
// All other values are symbolic.
|
|
return svalBuilder.getRegionValueSymbolVal(R);
|
|
}
|
|
|
|
SVal RegionStoreManager::getBindingForObjCIvar(RegionBindingsConstRef B,
|
|
const ObjCIvarRegion* R) {
|
|
// Check if the region has a binding.
|
|
if (const Optional<SVal> &V = B.getDirectBinding(R))
|
|
return *V;
|
|
|
|
const MemRegion *superR = R->getSuperRegion();
|
|
|
|
// Check if the super region has a default binding.
|
|
if (const Optional<SVal> &V = B.getDefaultBinding(superR)) {
|
|
if (SymbolRef parentSym = V->getAsSymbol())
|
|
return svalBuilder.getDerivedRegionValueSymbolVal(parentSym, R);
|
|
|
|
// Other cases: give up.
|
|
return UnknownVal();
|
|
}
|
|
|
|
return getBindingForLazySymbol(R);
|
|
}
|
|
|
|
SVal RegionStoreManager::getBindingForVar(RegionBindingsConstRef B,
|
|
const VarRegion *R) {
|
|
|
|
// Check if the region has a binding.
|
|
if (Optional<SVal> V = B.getDirectBinding(R))
|
|
return *V;
|
|
|
|
if (Optional<SVal> V = B.getDefaultBinding(R))
|
|
return *V;
|
|
|
|
// Lazily derive a value for the VarRegion.
|
|
const VarDecl *VD = R->getDecl();
|
|
const MemSpaceRegion *MS = R->getMemorySpace();
|
|
|
|
// Arguments are always symbolic.
|
|
if (isa<StackArgumentsSpaceRegion>(MS))
|
|
return svalBuilder.getRegionValueSymbolVal(R);
|
|
|
|
// Is 'VD' declared constant? If so, retrieve the constant value.
|
|
if (VD->getType().isConstQualified()) {
|
|
if (const Expr *Init = VD->getAnyInitializer()) {
|
|
if (Optional<SVal> V = svalBuilder.getConstantVal(Init))
|
|
return *V;
|
|
|
|
// If the variable is const qualified and has an initializer but
|
|
// we couldn't evaluate initializer to a value, treat the value as
|
|
// unknown.
|
|
return UnknownVal();
|
|
}
|
|
}
|
|
|
|
// This must come after the check for constants because closure-captured
|
|
// constant variables may appear in UnknownSpaceRegion.
|
|
if (isa<UnknownSpaceRegion>(MS))
|
|
return svalBuilder.getRegionValueSymbolVal(R);
|
|
|
|
if (isa<GlobalsSpaceRegion>(MS)) {
|
|
QualType T = VD->getType();
|
|
|
|
// If we're in main(), then global initializers have not become stale yet.
|
|
if (B.isMainAnalysis())
|
|
if (const Expr *Init = VD->getAnyInitializer())
|
|
if (Optional<SVal> V = svalBuilder.getConstantVal(Init))
|
|
return *V;
|
|
|
|
// Function-scoped static variables are default-initialized to 0; if they
|
|
// have an initializer, it would have been processed by now.
|
|
// FIXME: This is only true when we're starting analysis from main().
|
|
// We're losing a lot of coverage here.
|
|
if (isa<StaticGlobalSpaceRegion>(MS))
|
|
return svalBuilder.makeZeroVal(T);
|
|
|
|
if (Optional<SVal> V = getBindingForDerivedDefaultValue(B, MS, R, T)) {
|
|
assert(!V->getAs<nonloc::LazyCompoundVal>());
|
|
return V.getValue();
|
|
}
|
|
|
|
return svalBuilder.getRegionValueSymbolVal(R);
|
|
}
|
|
|
|
return UndefinedVal();
|
|
}
|
|
|
|
SVal RegionStoreManager::getBindingForLazySymbol(const TypedValueRegion *R) {
|
|
// All other values are symbolic.
|
|
return svalBuilder.getRegionValueSymbolVal(R);
|
|
}
|
|
|
|
const RegionStoreManager::SValListTy &
|
|
RegionStoreManager::getInterestingValues(nonloc::LazyCompoundVal LCV) {
|
|
// First, check the cache.
|
|
LazyBindingsMapTy::iterator I = LazyBindingsMap.find(LCV.getCVData());
|
|
if (I != LazyBindingsMap.end())
|
|
return I->second;
|
|
|
|
// If we don't have a list of values cached, start constructing it.
|
|
SValListTy List;
|
|
|
|
const SubRegion *LazyR = LCV.getRegion();
|
|
RegionBindingsRef B = getRegionBindings(LCV.getStore());
|
|
|
|
// If this region had /no/ bindings at the time, there are no interesting
|
|
// values to return.
|
|
const ClusterBindings *Cluster = B.lookup(LazyR->getBaseRegion());
|
|
if (!Cluster)
|
|
return (LazyBindingsMap[LCV.getCVData()] = std::move(List));
|
|
|
|
SmallVector<BindingPair, 32> Bindings;
|
|
collectSubRegionBindings(Bindings, svalBuilder, *Cluster, LazyR,
|
|
/*IncludeAllDefaultBindings=*/true);
|
|
for (SmallVectorImpl<BindingPair>::const_iterator I = Bindings.begin(),
|
|
E = Bindings.end();
|
|
I != E; ++I) {
|
|
SVal V = I->second;
|
|
if (V.isUnknownOrUndef() || V.isConstant())
|
|
continue;
|
|
|
|
if (Optional<nonloc::LazyCompoundVal> InnerLCV =
|
|
V.getAs<nonloc::LazyCompoundVal>()) {
|
|
const SValListTy &InnerList = getInterestingValues(*InnerLCV);
|
|
List.insert(List.end(), InnerList.begin(), InnerList.end());
|
|
continue;
|
|
}
|
|
|
|
List.push_back(V);
|
|
}
|
|
|
|
return (LazyBindingsMap[LCV.getCVData()] = std::move(List));
|
|
}
|
|
|
|
NonLoc RegionStoreManager::createLazyBinding(RegionBindingsConstRef B,
|
|
const TypedValueRegion *R) {
|
|
if (Optional<nonloc::LazyCompoundVal> V =
|
|
getExistingLazyBinding(svalBuilder, B, R, false))
|
|
return *V;
|
|
|
|
return svalBuilder.makeLazyCompoundVal(StoreRef(B.asStore(), *this), R);
|
|
}
|
|
|
|
static bool isRecordEmpty(const RecordDecl *RD) {
|
|
if (!RD->field_empty())
|
|
return false;
|
|
if (const CXXRecordDecl *CRD = dyn_cast<CXXRecordDecl>(RD))
|
|
return CRD->getNumBases() == 0;
|
|
return true;
|
|
}
|
|
|
|
SVal RegionStoreManager::getBindingForStruct(RegionBindingsConstRef B,
|
|
const TypedValueRegion *R) {
|
|
const RecordDecl *RD = R->getValueType()->castAs<RecordType>()->getDecl();
|
|
if (!RD->getDefinition() || isRecordEmpty(RD))
|
|
return UnknownVal();
|
|
|
|
return createLazyBinding(B, R);
|
|
}
|
|
|
|
SVal RegionStoreManager::getBindingForArray(RegionBindingsConstRef B,
|
|
const TypedValueRegion *R) {
|
|
assert(Ctx.getAsConstantArrayType(R->getValueType()) &&
|
|
"Only constant array types can have compound bindings.");
|
|
|
|
return createLazyBinding(B, R);
|
|
}
|
|
|
|
bool RegionStoreManager::includedInBindings(Store store,
|
|
const MemRegion *region) const {
|
|
RegionBindingsRef B = getRegionBindings(store);
|
|
region = region->getBaseRegion();
|
|
|
|
// Quick path: if the base is the head of a cluster, the region is live.
|
|
if (B.lookup(region))
|
|
return true;
|
|
|
|
// Slow path: if the region is the VALUE of any binding, it is live.
|
|
for (RegionBindingsRef::iterator RI = B.begin(), RE = B.end(); RI != RE; ++RI) {
|
|
const ClusterBindings &Cluster = RI.getData();
|
|
for (ClusterBindings::iterator CI = Cluster.begin(), CE = Cluster.end();
|
|
CI != CE; ++CI) {
|
|
const SVal &D = CI.getData();
|
|
if (const MemRegion *R = D.getAsRegion())
|
|
if (R->getBaseRegion() == region)
|
|
return true;
|
|
}
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
// Binding values to regions.
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
StoreRef RegionStoreManager::killBinding(Store ST, Loc L) {
|
|
if (Optional<loc::MemRegionVal> LV = L.getAs<loc::MemRegionVal>())
|
|
if (const MemRegion* R = LV->getRegion())
|
|
return StoreRef(getRegionBindings(ST).removeBinding(R)
|
|
.asImmutableMap()
|
|
.getRootWithoutRetain(),
|
|
*this);
|
|
|
|
return StoreRef(ST, *this);
|
|
}
|
|
|
|
RegionBindingsRef
|
|
RegionStoreManager::bind(RegionBindingsConstRef B, Loc L, SVal V) {
|
|
if (L.getAs<loc::ConcreteInt>())
|
|
return B;
|
|
|
|
// If we get here, the location should be a region.
|
|
const MemRegion *R = L.castAs<loc::MemRegionVal>().getRegion();
|
|
|
|
// Check if the region is a struct region.
|
|
if (const TypedValueRegion* TR = dyn_cast<TypedValueRegion>(R)) {
|
|
QualType Ty = TR->getValueType();
|
|
if (Ty->isArrayType())
|
|
return bindArray(B, TR, V);
|
|
if (Ty->isStructureOrClassType())
|
|
return bindStruct(B, TR, V);
|
|
if (Ty->isVectorType())
|
|
return bindVector(B, TR, V);
|
|
if (Ty->isUnionType())
|
|
return bindAggregate(B, TR, V);
|
|
}
|
|
|
|
if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(R)) {
|
|
// Binding directly to a symbolic region should be treated as binding
|
|
// to element 0.
|
|
QualType T = SR->getSymbol()->getType();
|
|
if (T->isAnyPointerType() || T->isReferenceType())
|
|
T = T->getPointeeType();
|
|
|
|
R = GetElementZeroRegion(SR, T);
|
|
}
|
|
|
|
assert((!isa<CXXThisRegion>(R) || !B.lookup(R)) &&
|
|
"'this' pointer is not an l-value and is not assignable");
|
|
|
|
// Clear out bindings that may overlap with this binding.
|
|
RegionBindingsRef NewB = removeSubRegionBindings(B, cast<SubRegion>(R));
|
|
return NewB.addBinding(BindingKey::Make(R, BindingKey::Direct), V);
|
|
}
|
|
|
|
RegionBindingsRef
|
|
RegionStoreManager::setImplicitDefaultValue(RegionBindingsConstRef B,
|
|
const MemRegion *R,
|
|
QualType T) {
|
|
SVal V;
|
|
|
|
if (Loc::isLocType(T))
|
|
V = svalBuilder.makeNull();
|
|
else if (T->isIntegralOrEnumerationType())
|
|
V = svalBuilder.makeZeroVal(T);
|
|
else if (T->isStructureOrClassType() || T->isArrayType()) {
|
|
// Set the default value to a zero constant when it is a structure
|
|
// or array. The type doesn't really matter.
|
|
V = svalBuilder.makeZeroVal(Ctx.IntTy);
|
|
}
|
|
else {
|
|
// We can't represent values of this type, but we still need to set a value
|
|
// to record that the region has been initialized.
|
|
// If this assertion ever fires, a new case should be added above -- we
|
|
// should know how to default-initialize any value we can symbolicate.
|
|
assert(!SymbolManager::canSymbolicate(T) && "This type is representable");
|
|
V = UnknownVal();
|
|
}
|
|
|
|
return B.addBinding(R, BindingKey::Default, V);
|
|
}
|
|
|
|
RegionBindingsRef
|
|
RegionStoreManager::bindArray(RegionBindingsConstRef B,
|
|
const TypedValueRegion* R,
|
|
SVal Init) {
|
|
|
|
const ArrayType *AT =cast<ArrayType>(Ctx.getCanonicalType(R->getValueType()));
|
|
QualType ElementTy = AT->getElementType();
|
|
Optional<uint64_t> Size;
|
|
|
|
if (const ConstantArrayType* CAT = dyn_cast<ConstantArrayType>(AT))
|
|
Size = CAT->getSize().getZExtValue();
|
|
|
|
// Check if the init expr is a literal. If so, bind the rvalue instead.
|
|
// FIXME: It's not responsibility of the Store to transform this lvalue
|
|
// to rvalue. ExprEngine or maybe even CFG should do this before binding.
|
|
if (Optional<loc::MemRegionVal> MRV = Init.getAs<loc::MemRegionVal>()) {
|
|
SVal V = getBinding(B.asStore(), *MRV, R->getValueType());
|
|
return bindAggregate(B, R, V);
|
|
}
|
|
|
|
// Handle lazy compound values.
|
|
if (Init.getAs<nonloc::LazyCompoundVal>())
|
|
return bindAggregate(B, R, Init);
|
|
|
|
if (Init.isUnknown())
|
|
return bindAggregate(B, R, UnknownVal());
|
|
|
|
// Remaining case: explicit compound values.
|
|
const nonloc::CompoundVal& CV = Init.castAs<nonloc::CompoundVal>();
|
|
nonloc::CompoundVal::iterator VI = CV.begin(), VE = CV.end();
|
|
uint64_t i = 0;
|
|
|
|
RegionBindingsRef NewB(B);
|
|
|
|
for (; Size.hasValue() ? i < Size.getValue() : true ; ++i, ++VI) {
|
|
// The init list might be shorter than the array length.
|
|
if (VI == VE)
|
|
break;
|
|
|
|
const NonLoc &Idx = svalBuilder.makeArrayIndex(i);
|
|
const ElementRegion *ER = MRMgr.getElementRegion(ElementTy, Idx, R, Ctx);
|
|
|
|
if (ElementTy->isStructureOrClassType())
|
|
NewB = bindStruct(NewB, ER, *VI);
|
|
else if (ElementTy->isArrayType())
|
|
NewB = bindArray(NewB, ER, *VI);
|
|
else
|
|
NewB = bind(NewB, loc::MemRegionVal(ER), *VI);
|
|
}
|
|
|
|
// If the init list is shorter than the array length (or the array has
|
|
// variable length), set the array default value. Values that are already set
|
|
// are not overwritten.
|
|
if (!Size.hasValue() || i < Size.getValue())
|
|
NewB = setImplicitDefaultValue(NewB, R, ElementTy);
|
|
|
|
return NewB;
|
|
}
|
|
|
|
RegionBindingsRef RegionStoreManager::bindVector(RegionBindingsConstRef B,
|
|
const TypedValueRegion* R,
|
|
SVal V) {
|
|
QualType T = R->getValueType();
|
|
const VectorType *VT = T->castAs<VectorType>(); // Use castAs for typedefs.
|
|
|
|
// Handle lazy compound values and symbolic values.
|
|
if (V.getAs<nonloc::LazyCompoundVal>() || V.getAs<nonloc::SymbolVal>())
|
|
return bindAggregate(B, R, V);
|
|
|
|
// We may get non-CompoundVal accidentally due to imprecise cast logic or
|
|
// that we are binding symbolic struct value. Kill the field values, and if
|
|
// the value is symbolic go and bind it as a "default" binding.
|
|
if (!V.getAs<nonloc::CompoundVal>()) {
|
|
return bindAggregate(B, R, UnknownVal());
|
|
}
|
|
|
|
QualType ElemType = VT->getElementType();
|
|
nonloc::CompoundVal CV = V.castAs<nonloc::CompoundVal>();
|
|
nonloc::CompoundVal::iterator VI = CV.begin(), VE = CV.end();
|
|
unsigned index = 0, numElements = VT->getNumElements();
|
|
RegionBindingsRef NewB(B);
|
|
|
|
for ( ; index != numElements ; ++index) {
|
|
if (VI == VE)
|
|
break;
|
|
|
|
NonLoc Idx = svalBuilder.makeArrayIndex(index);
|
|
const ElementRegion *ER = MRMgr.getElementRegion(ElemType, Idx, R, Ctx);
|
|
|
|
if (ElemType->isArrayType())
|
|
NewB = bindArray(NewB, ER, *VI);
|
|
else if (ElemType->isStructureOrClassType())
|
|
NewB = bindStruct(NewB, ER, *VI);
|
|
else
|
|
NewB = bind(NewB, loc::MemRegionVal(ER), *VI);
|
|
}
|
|
return NewB;
|
|
}
|
|
|
|
Optional<RegionBindingsRef>
|
|
RegionStoreManager::tryBindSmallStruct(RegionBindingsConstRef B,
|
|
const TypedValueRegion *R,
|
|
const RecordDecl *RD,
|
|
nonloc::LazyCompoundVal LCV) {
|
|
FieldVector Fields;
|
|
|
|
if (const CXXRecordDecl *Class = dyn_cast<CXXRecordDecl>(RD))
|
|
if (Class->getNumBases() != 0 || Class->getNumVBases() != 0)
|
|
return None;
|
|
|
|
for (const auto *FD : RD->fields()) {
|
|
if (FD->isUnnamedBitfield())
|
|
continue;
|
|
|
|
// If there are too many fields, or if any of the fields are aggregates,
|
|
// just use the LCV as a default binding.
|
|
if (Fields.size() == SmallStructLimit)
|
|
return None;
|
|
|
|
QualType Ty = FD->getType();
|
|
if (!(Ty->isScalarType() || Ty->isReferenceType()))
|
|
return None;
|
|
|
|
Fields.push_back(FD);
|
|
}
|
|
|
|
RegionBindingsRef NewB = B;
|
|
|
|
for (FieldVector::iterator I = Fields.begin(), E = Fields.end(); I != E; ++I){
|
|
const FieldRegion *SourceFR = MRMgr.getFieldRegion(*I, LCV.getRegion());
|
|
SVal V = getBindingForField(getRegionBindings(LCV.getStore()), SourceFR);
|
|
|
|
const FieldRegion *DestFR = MRMgr.getFieldRegion(*I, R);
|
|
NewB = bind(NewB, loc::MemRegionVal(DestFR), V);
|
|
}
|
|
|
|
return NewB;
|
|
}
|
|
|
|
RegionBindingsRef RegionStoreManager::bindStruct(RegionBindingsConstRef B,
|
|
const TypedValueRegion* R,
|
|
SVal V) {
|
|
if (!Features.supportsFields())
|
|
return B;
|
|
|
|
QualType T = R->getValueType();
|
|
assert(T->isStructureOrClassType());
|
|
|
|
const RecordType* RT = T->castAs<RecordType>();
|
|
const RecordDecl *RD = RT->getDecl();
|
|
|
|
if (!RD->isCompleteDefinition())
|
|
return B;
|
|
|
|
// Handle lazy compound values and symbolic values.
|
|
if (Optional<nonloc::LazyCompoundVal> LCV =
|
|
V.getAs<nonloc::LazyCompoundVal>()) {
|
|
if (Optional<RegionBindingsRef> NewB = tryBindSmallStruct(B, R, RD, *LCV))
|
|
return *NewB;
|
|
return bindAggregate(B, R, V);
|
|
}
|
|
if (V.getAs<nonloc::SymbolVal>())
|
|
return bindAggregate(B, R, V);
|
|
|
|
// We may get non-CompoundVal accidentally due to imprecise cast logic or
|
|
// that we are binding symbolic struct value. Kill the field values, and if
|
|
// the value is symbolic go and bind it as a "default" binding.
|
|
if (V.isUnknown() || !V.getAs<nonloc::CompoundVal>())
|
|
return bindAggregate(B, R, UnknownVal());
|
|
|
|
// The raw CompoundVal is essentially a symbolic InitListExpr: an (immutable)
|
|
// list of other values. It appears pretty much only when there's an actual
|
|
// initializer list expression in the program, and the analyzer tries to
|
|
// unwrap it as soon as possible.
|
|
// This code is where such unwrap happens: when the compound value is put into
|
|
// the object that it was supposed to initialize (it's an *initializer* list,
|
|
// after all), instead of binding the whole value to the whole object, we bind
|
|
// sub-values to sub-objects. Sub-values may themselves be compound values,
|
|
// and in this case the procedure becomes recursive.
|
|
// FIXME: The annoying part about compound values is that they don't carry
|
|
// any sort of information about which value corresponds to which sub-object.
|
|
// It's simply a list of values in the middle of nowhere; we expect to match
|
|
// them to sub-objects, essentially, "by index": first value binds to
|
|
// the first field, second value binds to the second field, etc.
|
|
// It would have been much safer to organize non-lazy compound values as
|
|
// a mapping from fields/bases to values.
|
|
const nonloc::CompoundVal& CV = V.castAs<nonloc::CompoundVal>();
|
|
nonloc::CompoundVal::iterator VI = CV.begin(), VE = CV.end();
|
|
|
|
RegionBindingsRef NewB(B);
|
|
|
|
// In C++17 aggregates may have base classes, handle those as well.
|
|
// They appear before fields in the initializer list / compound value.
|
|
if (const auto *CRD = dyn_cast<CXXRecordDecl>(RD)) {
|
|
// If the object was constructed with a constructor, its value is a
|
|
// LazyCompoundVal. If it's a raw CompoundVal, it means that we're
|
|
// performing aggregate initialization. The only exception from this
|
|
// rule is sending an Objective-C++ message that returns a C++ object
|
|
// to a nil receiver; in this case the semantics is to return a
|
|
// zero-initialized object even if it's a C++ object that doesn't have
|
|
// this sort of constructor; the CompoundVal is empty in this case.
|
|
assert((CRD->isAggregate() || (Ctx.getLangOpts().ObjC && VI == VE)) &&
|
|
"Non-aggregates are constructed with a constructor!");
|
|
|
|
for (const auto &B : CRD->bases()) {
|
|
// (Multiple inheritance is fine though.)
|
|
assert(!B.isVirtual() && "Aggregates cannot have virtual base classes!");
|
|
|
|
if (VI == VE)
|
|
break;
|
|
|
|
QualType BTy = B.getType();
|
|
assert(BTy->isStructureOrClassType() && "Base classes must be classes!");
|
|
|
|
const CXXRecordDecl *BRD = BTy->getAsCXXRecordDecl();
|
|
assert(BRD && "Base classes must be C++ classes!");
|
|
|
|
const CXXBaseObjectRegion *BR =
|
|
MRMgr.getCXXBaseObjectRegion(BRD, R, /*IsVirtual=*/false);
|
|
|
|
NewB = bindStruct(NewB, BR, *VI);
|
|
|
|
++VI;
|
|
}
|
|
}
|
|
|
|
RecordDecl::field_iterator FI, FE;
|
|
|
|
for (FI = RD->field_begin(), FE = RD->field_end(); FI != FE; ++FI) {
|
|
|
|
if (VI == VE)
|
|
break;
|
|
|
|
// Skip any unnamed bitfields to stay in sync with the initializers.
|
|
if (FI->isUnnamedBitfield())
|
|
continue;
|
|
|
|
QualType FTy = FI->getType();
|
|
const FieldRegion* FR = MRMgr.getFieldRegion(*FI, R);
|
|
|
|
if (FTy->isArrayType())
|
|
NewB = bindArray(NewB, FR, *VI);
|
|
else if (FTy->isStructureOrClassType())
|
|
NewB = bindStruct(NewB, FR, *VI);
|
|
else
|
|
NewB = bind(NewB, loc::MemRegionVal(FR), *VI);
|
|
++VI;
|
|
}
|
|
|
|
// There may be fewer values in the initialize list than the fields of struct.
|
|
if (FI != FE) {
|
|
NewB = NewB.addBinding(R, BindingKey::Default,
|
|
svalBuilder.makeIntVal(0, false));
|
|
}
|
|
|
|
return NewB;
|
|
}
|
|
|
|
RegionBindingsRef
|
|
RegionStoreManager::bindAggregate(RegionBindingsConstRef B,
|
|
const TypedRegion *R,
|
|
SVal Val) {
|
|
// Remove the old bindings, using 'R' as the root of all regions
|
|
// we will invalidate. Then add the new binding.
|
|
return removeSubRegionBindings(B, R).addBinding(R, BindingKey::Default, Val);
|
|
}
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
// State pruning.
|
|
//===----------------------------------------------------------------------===//
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namespace {
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class RemoveDeadBindingsWorker
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: public ClusterAnalysis<RemoveDeadBindingsWorker> {
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SmallVector<const SymbolicRegion *, 12> Postponed;
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SymbolReaper &SymReaper;
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const StackFrameContext *CurrentLCtx;
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public:
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RemoveDeadBindingsWorker(RegionStoreManager &rm,
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ProgramStateManager &stateMgr,
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RegionBindingsRef b, SymbolReaper &symReaper,
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const StackFrameContext *LCtx)
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: ClusterAnalysis<RemoveDeadBindingsWorker>(rm, stateMgr, b),
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SymReaper(symReaper), CurrentLCtx(LCtx) {}
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// Called by ClusterAnalysis.
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void VisitAddedToCluster(const MemRegion *baseR, const ClusterBindings &C);
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void VisitCluster(const MemRegion *baseR, const ClusterBindings *C);
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using ClusterAnalysis<RemoveDeadBindingsWorker>::VisitCluster;
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using ClusterAnalysis::AddToWorkList;
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bool AddToWorkList(const MemRegion *R);
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bool UpdatePostponed();
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void VisitBinding(SVal V);
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};
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}
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bool RemoveDeadBindingsWorker::AddToWorkList(const MemRegion *R) {
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const MemRegion *BaseR = R->getBaseRegion();
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return AddToWorkList(WorkListElement(BaseR), getCluster(BaseR));
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}
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void RemoveDeadBindingsWorker::VisitAddedToCluster(const MemRegion *baseR,
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const ClusterBindings &C) {
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if (const VarRegion *VR = dyn_cast<VarRegion>(baseR)) {
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if (SymReaper.isLive(VR))
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AddToWorkList(baseR, &C);
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return;
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}
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if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(baseR)) {
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if (SymReaper.isLive(SR->getSymbol()))
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AddToWorkList(SR, &C);
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else
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Postponed.push_back(SR);
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return;
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}
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if (isa<NonStaticGlobalSpaceRegion>(baseR)) {
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AddToWorkList(baseR, &C);
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return;
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}
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// CXXThisRegion in the current or parent location context is live.
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if (const CXXThisRegion *TR = dyn_cast<CXXThisRegion>(baseR)) {
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const auto *StackReg =
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cast<StackArgumentsSpaceRegion>(TR->getSuperRegion());
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const StackFrameContext *RegCtx = StackReg->getStackFrame();
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if (CurrentLCtx &&
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(RegCtx == CurrentLCtx || RegCtx->isParentOf(CurrentLCtx)))
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AddToWorkList(TR, &C);
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}
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}
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void RemoveDeadBindingsWorker::VisitCluster(const MemRegion *baseR,
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const ClusterBindings *C) {
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if (!C)
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return;
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// Mark the symbol for any SymbolicRegion with live bindings as live itself.
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// This means we should continue to track that symbol.
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if (const SymbolicRegion *SymR = dyn_cast<SymbolicRegion>(baseR))
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SymReaper.markLive(SymR->getSymbol());
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for (ClusterBindings::iterator I = C->begin(), E = C->end(); I != E; ++I) {
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// Element index of a binding key is live.
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SymReaper.markElementIndicesLive(I.getKey().getRegion());
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VisitBinding(I.getData());
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}
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}
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void RemoveDeadBindingsWorker::VisitBinding(SVal V) {
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// Is it a LazyCompoundVal? All referenced regions are live as well.
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if (Optional<nonloc::LazyCompoundVal> LCS =
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V.getAs<nonloc::LazyCompoundVal>()) {
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const RegionStoreManager::SValListTy &Vals = RM.getInterestingValues(*LCS);
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for (RegionStoreManager::SValListTy::const_iterator I = Vals.begin(),
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E = Vals.end();
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I != E; ++I)
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VisitBinding(*I);
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return;
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}
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// If V is a region, then add it to the worklist.
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if (const MemRegion *R = V.getAsRegion()) {
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AddToWorkList(R);
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SymReaper.markLive(R);
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// All regions captured by a block are also live.
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if (const BlockDataRegion *BR = dyn_cast<BlockDataRegion>(R)) {
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BlockDataRegion::referenced_vars_iterator I = BR->referenced_vars_begin(),
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E = BR->referenced_vars_end();
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for ( ; I != E; ++I)
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AddToWorkList(I.getCapturedRegion());
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}
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}
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// Update the set of live symbols.
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for (auto SI = V.symbol_begin(), SE = V.symbol_end(); SI!=SE; ++SI)
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SymReaper.markLive(*SI);
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}
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bool RemoveDeadBindingsWorker::UpdatePostponed() {
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// See if any postponed SymbolicRegions are actually live now, after
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// having done a scan.
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bool Changed = false;
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for (auto I = Postponed.begin(), E = Postponed.end(); I != E; ++I) {
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if (const SymbolicRegion *SR = *I) {
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if (SymReaper.isLive(SR->getSymbol())) {
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Changed |= AddToWorkList(SR);
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*I = nullptr;
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}
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}
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}
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return Changed;
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}
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StoreRef RegionStoreManager::removeDeadBindings(Store store,
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const StackFrameContext *LCtx,
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SymbolReaper& SymReaper) {
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RegionBindingsRef B = getRegionBindings(store);
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RemoveDeadBindingsWorker W(*this, StateMgr, B, SymReaper, LCtx);
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W.GenerateClusters();
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// Enqueue the region roots onto the worklist.
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for (SymbolReaper::region_iterator I = SymReaper.region_begin(),
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E = SymReaper.region_end(); I != E; ++I) {
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W.AddToWorkList(*I);
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}
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do W.RunWorkList(); while (W.UpdatePostponed());
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// We have now scanned the store, marking reachable regions and symbols
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// as live. We now remove all the regions that are dead from the store
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// as well as update DSymbols with the set symbols that are now dead.
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for (RegionBindingsRef::iterator I = B.begin(), E = B.end(); I != E; ++I) {
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const MemRegion *Base = I.getKey();
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// If the cluster has been visited, we know the region has been marked.
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// Otherwise, remove the dead entry.
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if (!W.isVisited(Base))
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B = B.remove(Base);
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}
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return StoreRef(B.asStore(), *this);
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}
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//===----------------------------------------------------------------------===//
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// Utility methods.
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//===----------------------------------------------------------------------===//
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void RegionStoreManager::printJson(raw_ostream &Out, Store S, const char *NL,
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unsigned int Space, bool IsDot) const {
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RegionBindingsRef Bindings = getRegionBindings(S);
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Indent(Out, Space, IsDot) << "\"store\": ";
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if (Bindings.isEmpty()) {
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Out << "null," << NL;
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return;
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}
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Out << "{ \"pointer\": \"" << Bindings.asStore() << "\", \"items\": [" << NL;
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Bindings.printJson(Out, NL, Space + 1, IsDot);
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Indent(Out, Space, IsDot) << "]}," << NL;
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}
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