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//===- ExprEngine.h - Path-Sensitive Expression-Level Dataflow --*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file defines a meta-engine for path-sensitive dataflow analysis that
// is built on CoreEngine, but provides the boilerplate to execute transfer
// functions and build the ExplodedGraph at the expression level.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_CLANG_STATICANALYZER_CORE_PATHSENSITIVE_EXPRENGINE_H
#define LLVM_CLANG_STATICANALYZER_CORE_PATHSENSITIVE_EXPRENGINE_H
#include "clang/AST/Expr.h"
#include "clang/AST/Type.h"
#include "clang/Analysis/CFG.h"
#include "clang/Analysis/DomainSpecific/ObjCNoReturn.h"
#include "clang/Analysis/ProgramPoint.h"
#include "clang/Basic/LLVM.h"
#include "clang/StaticAnalyzer/Core/CheckerManager.h"
#include "clang/StaticAnalyzer/Core/BugReporter/BugReporter.h"
#include "clang/StaticAnalyzer/Core/BugReporter/BugReporterVisitors.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/AnalysisManager.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/CoreEngine.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/FunctionSummary.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/ProgramState.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/ProgramStateTrait.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/ProgramState_Fwd.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/Store.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/SValBuilder.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/SVals.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/WorkList.h"
#include "llvm/ADT/ArrayRef.h"
#include <cassert>
#include <optional>
#include <utility>
namespace clang {
class AnalysisDeclContextManager;
class AnalyzerOptions;
class ASTContext;
class CFGBlock;
class CFGElement;
class ConstructionContext;
class CXXBindTemporaryExpr;
class CXXCatchStmt;
class CXXConstructExpr;
class CXXDeleteExpr;
class CXXNewExpr;
class CXXThisExpr;
class Decl;
class DeclStmt;
class GCCAsmStmt;
class LambdaExpr;
class LocationContext;
class MaterializeTemporaryExpr;
class MSAsmStmt;
class NamedDecl;
class ObjCAtSynchronizedStmt;
class ObjCForCollectionStmt;
class ObjCIvarRefExpr;
class ObjCMessageExpr;
class ReturnStmt;
class Stmt;
namespace cross_tu {
class CrossTranslationUnitContext;
} // namespace cross_tu
namespace ento {
class AnalysisManager;
class BasicValueFactory;
class CallEvent;
class CheckerManager;
class ConstraintManager;
class ExplodedNodeSet;
class ExplodedNode;
class IndirectGotoNodeBuilder;
class MemRegion;
class NodeBuilderContext;
class NodeBuilderWithSinks;
class ProgramState;
class ProgramStateManager;
class RegionAndSymbolInvalidationTraits;
class SymbolManager;
class SwitchNodeBuilder;
/// Hints for figuring out of a call should be inlined during evalCall().
struct EvalCallOptions {
/// This call is a constructor or a destructor for which we do not currently
/// compute the this-region correctly.
bool IsCtorOrDtorWithImproperlyModeledTargetRegion = false;
/// This call is a constructor or a destructor for a single element within
/// an array, a part of array construction or destruction.
bool IsArrayCtorOrDtor = false;
/// This call is a constructor or a destructor of a temporary value.
bool IsTemporaryCtorOrDtor = false;
/// This call is a constructor for a temporary that is lifetime-extended
/// by binding it to a reference-type field within an aggregate,
/// for example 'A { const C &c; }; A a = { C() };'
bool IsTemporaryLifetimeExtendedViaAggregate = false;
/// This call is a pre-C++17 elidable constructor that we failed to elide
/// because we failed to compute the target region into which
/// this constructor would have been ultimately elided. Analysis that
/// we perform in this case is still correct but it behaves differently,
/// as if copy elision is disabled.
bool IsElidableCtorThatHasNotBeenElided = false;
EvalCallOptions() {}
};
class ExprEngine {
void anchor();
public:
/// The modes of inlining, which override the default analysis-wide settings.
enum InliningModes {
/// Follow the default settings for inlining callees.
Inline_Regular = 0,
/// Do minimal inlining of callees.
Inline_Minimal = 0x1
};
private:
cross_tu::CrossTranslationUnitContext &CTU;
bool IsCTUEnabled;
AnalysisManager &AMgr;
AnalysisDeclContextManager &AnalysisDeclContexts;
CoreEngine Engine;
/// G - the simulation graph.
ExplodedGraph &G;
/// StateMgr - Object that manages the data for all created states.
ProgramStateManager StateMgr;
/// SymMgr - Object that manages the symbol information.
SymbolManager &SymMgr;
/// MRMgr - MemRegionManager object that creates memory regions.
MemRegionManager &MRMgr;
/// svalBuilder - SValBuilder object that creates SVals from expressions.
SValBuilder &svalBuilder;
unsigned int currStmtIdx = 0;
const NodeBuilderContext *currBldrCtx = nullptr;
/// Helper object to determine if an Objective-C message expression
/// implicitly never returns.
ObjCNoReturn ObjCNoRet;
/// The BugReporter associated with this engine. It is important that
/// this object be placed at the very end of member variables so that its
/// destructor is called before the rest of the ExprEngine is destroyed.
PathSensitiveBugReporter BR;
/// The functions which have been analyzed through inlining. This is owned by
/// AnalysisConsumer. It can be null.
SetOfConstDecls *VisitedCallees;
/// The flag, which specifies the mode of inlining for the engine.
InliningModes HowToInline;
public:
ExprEngine(cross_tu::CrossTranslationUnitContext &CTU, AnalysisManager &mgr,
SetOfConstDecls *VisitedCalleesIn,
FunctionSummariesTy *FS, InliningModes HowToInlineIn);
virtual ~ExprEngine() = default;
/// Returns true if there is still simulation state on the worklist.
bool ExecuteWorkList(const LocationContext *L, unsigned Steps = 150000) {
assert(L->inTopFrame());
BR.setAnalysisEntryPoint(L->getDecl());
return Engine.ExecuteWorkList(L, Steps, nullptr);
}
/// getContext - Return the ASTContext associated with this analysis.
ASTContext &getContext() const { return AMgr.getASTContext(); }
AnalysisManager &getAnalysisManager() { return AMgr; }
AnalysisDeclContextManager &getAnalysisDeclContextManager() {
return AMgr.getAnalysisDeclContextManager();
}
CheckerManager &getCheckerManager() const {
return *AMgr.getCheckerManager();
}
SValBuilder &getSValBuilder() { return svalBuilder; }
BugReporter &getBugReporter() { return BR; }
cross_tu::CrossTranslationUnitContext *
getCrossTranslationUnitContext() {
return &CTU;
}
const NodeBuilderContext &getBuilderContext() {
assert(currBldrCtx);
return *currBldrCtx;
}
const Stmt *getStmt() const;
const LocationContext *getRootLocationContext() const {
assert(G.roots_begin() != G.roots_end());
return (*G.roots_begin())->getLocation().getLocationContext();
}
CFGBlock::ConstCFGElementRef getCFGElementRef() const {
const CFGBlock *blockPtr = currBldrCtx ? currBldrCtx->getBlock() : nullptr;
return {blockPtr, currStmtIdx};
}
/// Dump graph to the specified filename.
/// If filename is empty, generate a temporary one.
/// \return The filename the graph is written into.
std::string DumpGraph(bool trim = false, StringRef Filename="");
/// Dump the graph consisting of the given nodes to a specified filename.
/// Generate a temporary filename if it's not provided.
/// \return The filename the graph is written into.
std::string DumpGraph(ArrayRef<const ExplodedNode *> Nodes,
StringRef Filename = "");
/// Visualize the ExplodedGraph created by executing the simulation.
void ViewGraph(bool trim = false);
/// Visualize a trimmed ExplodedGraph that only contains paths to the given
/// nodes.
void ViewGraph(ArrayRef<const ExplodedNode *> Nodes);
/// getInitialState - Return the initial state used for the root vertex
/// in the ExplodedGraph.
ProgramStateRef getInitialState(const LocationContext *InitLoc);
ExplodedGraph &getGraph() { return G; }
const ExplodedGraph &getGraph() const { return G; }
/// Run the analyzer's garbage collection - remove dead symbols and
/// bindings from the state.
///
/// Checkers can participate in this process with two callbacks:
/// \c checkLiveSymbols and \c checkDeadSymbols. See the CheckerDocumentation
/// class for more information.
///
/// \param Node The predecessor node, from which the processing should start.
/// \param Out The returned set of output nodes.
/// \param ReferenceStmt The statement which is about to be processed.
/// Everything needed for this statement should be considered live.
/// A null statement means that everything in child LocationContexts
/// is dead.
/// \param LC The location context of the \p ReferenceStmt. A null location
/// context means that we have reached the end of analysis and that
/// all statements and local variables should be considered dead.
/// \param DiagnosticStmt Used as a location for any warnings that should
/// occur while removing the dead (e.g. leaks). By default, the
/// \p ReferenceStmt is used.
/// \param K Denotes whether this is a pre- or post-statement purge. This
/// must only be ProgramPoint::PostStmtPurgeDeadSymbolsKind if an
/// entire location context is being cleared, in which case the
/// \p ReferenceStmt must either be a ReturnStmt or \c NULL. Otherwise,
/// it must be ProgramPoint::PreStmtPurgeDeadSymbolsKind (the default)
/// and \p ReferenceStmt must be valid (non-null).
void removeDead(ExplodedNode *Node, ExplodedNodeSet &Out,
const Stmt *ReferenceStmt, const LocationContext *LC,
const Stmt *DiagnosticStmt = nullptr,
ProgramPoint::Kind K = ProgramPoint::PreStmtPurgeDeadSymbolsKind);
/// processCFGElement - Called by CoreEngine. Used to generate new successor
/// nodes by processing the 'effects' of a CFG element.
void processCFGElement(const CFGElement E, ExplodedNode *Pred,
unsigned StmtIdx, NodeBuilderContext *Ctx);
void ProcessStmt(const Stmt *S, ExplodedNode *Pred);
void ProcessLoopExit(const Stmt* S, ExplodedNode *Pred);
void ProcessInitializer(const CFGInitializer I, ExplodedNode *Pred);
void ProcessImplicitDtor(const CFGImplicitDtor D, ExplodedNode *Pred);
void ProcessNewAllocator(const CXXNewExpr *NE, ExplodedNode *Pred);
void ProcessAutomaticObjDtor(const CFGAutomaticObjDtor D,
ExplodedNode *Pred, ExplodedNodeSet &Dst);
void ProcessDeleteDtor(const CFGDeleteDtor D,
ExplodedNode *Pred, ExplodedNodeSet &Dst);
void ProcessBaseDtor(const CFGBaseDtor D,
ExplodedNode *Pred, ExplodedNodeSet &Dst);
void ProcessMemberDtor(const CFGMemberDtor D,
ExplodedNode *Pred, ExplodedNodeSet &Dst);
void ProcessTemporaryDtor(const CFGTemporaryDtor D,
ExplodedNode *Pred, ExplodedNodeSet &Dst);
/// Called by CoreEngine when processing the entrance of a CFGBlock.
void processCFGBlockEntrance(const BlockEdge &L,
NodeBuilderWithSinks &nodeBuilder,
ExplodedNode *Pred);
/// ProcessBranch - Called by CoreEngine. Used to generate successor
/// nodes by processing the 'effects' of a branch condition.
void processBranch(const Stmt *Condition,
NodeBuilderContext& BuilderCtx,
ExplodedNode *Pred,
ExplodedNodeSet &Dst,
const CFGBlock *DstT,
const CFGBlock *DstF);
/// Called by CoreEngine.
/// Used to generate successor nodes for temporary destructors depending
/// on whether the corresponding constructor was visited.
void processCleanupTemporaryBranch(const CXXBindTemporaryExpr *BTE,
NodeBuilderContext &BldCtx,
ExplodedNode *Pred, ExplodedNodeSet &Dst,
const CFGBlock *DstT,
const CFGBlock *DstF);
/// Called by CoreEngine. Used to processing branching behavior
/// at static initializers.
void processStaticInitializer(const DeclStmt *DS,
NodeBuilderContext& BuilderCtx,
ExplodedNode *Pred,
ExplodedNodeSet &Dst,
const CFGBlock *DstT,
const CFGBlock *DstF);
/// processIndirectGoto - Called by CoreEngine. Used to generate successor
/// nodes by processing the 'effects' of a computed goto jump.
void processIndirectGoto(IndirectGotoNodeBuilder& builder);
/// ProcessSwitch - Called by CoreEngine. Used to generate successor
/// nodes by processing the 'effects' of a switch statement.
void processSwitch(SwitchNodeBuilder& builder);
/// Called by CoreEngine. Used to notify checkers that processing a
/// function has begun. Called for both inlined and top-level functions.
void processBeginOfFunction(NodeBuilderContext &BC,
ExplodedNode *Pred, ExplodedNodeSet &Dst,
const BlockEdge &L);
/// Called by CoreEngine. Used to notify checkers that processing a
/// function has ended. Called for both inlined and top-level functions.
void processEndOfFunction(NodeBuilderContext& BC,
ExplodedNode *Pred,
const ReturnStmt *RS = nullptr);
/// Remove dead bindings/symbols before exiting a function.
void removeDeadOnEndOfFunction(NodeBuilderContext& BC,
ExplodedNode *Pred,
ExplodedNodeSet &Dst);
/// Generate the entry node of the callee.
void processCallEnter(NodeBuilderContext& BC, CallEnter CE,
ExplodedNode *Pred);
/// Generate the sequence of nodes that simulate the call exit and the post
/// visit for CallExpr.
void processCallExit(ExplodedNode *Pred);
/// Called by CoreEngine when the analysis worklist has terminated.
void processEndWorklist();
/// evalAssume - Callback function invoked by the ConstraintManager when
/// making assumptions about state values.
ProgramStateRef processAssume(ProgramStateRef state, SVal cond,
bool assumption);
/// processRegionChanges - Called by ProgramStateManager whenever a change is made
/// to the store. Used to update checkers that track region values.
ProgramStateRef
processRegionChanges(ProgramStateRef state,
const InvalidatedSymbols *invalidated,
ArrayRef<const MemRegion *> ExplicitRegions,
ArrayRef<const MemRegion *> Regions,
const LocationContext *LCtx,
const CallEvent *Call);
inline ProgramStateRef
processRegionChange(ProgramStateRef state,
const MemRegion* MR,
const LocationContext *LCtx) {
return processRegionChanges(state, nullptr, MR, MR, LCtx, nullptr);
}
/// printJson - Called by ProgramStateManager to print checker-specific data.
void printJson(raw_ostream &Out, ProgramStateRef State,
const LocationContext *LCtx, const char *NL,
unsigned int Space, bool IsDot) const;
ProgramStateManager &getStateManager() { return StateMgr; }
StoreManager &getStoreManager() { return StateMgr.getStoreManager(); }
ConstraintManager &getConstraintManager() {
return StateMgr.getConstraintManager();
}
// FIXME: Remove when we migrate over to just using SValBuilder.
BasicValueFactory &getBasicVals() {
return StateMgr.getBasicVals();
}
SymbolManager &getSymbolManager() { return SymMgr; }
MemRegionManager &getRegionManager() { return MRMgr; }
DataTag::Factory &getDataTags() { return Engine.getDataTags(); }
// Functions for external checking of whether we have unfinished work
bool wasBlocksExhausted() const { return Engine.wasBlocksExhausted(); }
bool hasEmptyWorkList() const { return !Engine.getWorkList()->hasWork(); }
bool hasWorkRemaining() const { return Engine.hasWorkRemaining(); }
const CoreEngine &getCoreEngine() const { return Engine; }
public:
/// Visit - Transfer function logic for all statements. Dispatches to
/// other functions that handle specific kinds of statements.
void Visit(const Stmt *S, ExplodedNode *Pred, ExplodedNodeSet &Dst);
/// VisitArrayInitLoopExpr - Transfer function for array init loop.
void VisitArrayInitLoopExpr(const ArrayInitLoopExpr *Ex, ExplodedNode *Pred,
ExplodedNodeSet &Dst);
/// VisitArraySubscriptExpr - Transfer function for array accesses.
void VisitArraySubscriptExpr(const ArraySubscriptExpr *Ex,
ExplodedNode *Pred,
ExplodedNodeSet &Dst);
/// VisitGCCAsmStmt - Transfer function logic for inline asm.
void VisitGCCAsmStmt(const GCCAsmStmt *A, ExplodedNode *Pred,
ExplodedNodeSet &Dst);
/// VisitMSAsmStmt - Transfer function logic for MS inline asm.
void VisitMSAsmStmt(const MSAsmStmt *A, ExplodedNode *Pred,
ExplodedNodeSet &Dst);
/// VisitBlockExpr - Transfer function logic for BlockExprs.
void VisitBlockExpr(const BlockExpr *BE, ExplodedNode *Pred,
ExplodedNodeSet &Dst);
/// VisitLambdaExpr - Transfer function logic for LambdaExprs.
void VisitLambdaExpr(const LambdaExpr *LE, ExplodedNode *Pred,
ExplodedNodeSet &Dst);
/// VisitBinaryOperator - Transfer function logic for binary operators.
void VisitBinaryOperator(const BinaryOperator* B, ExplodedNode *Pred,
ExplodedNodeSet &Dst);
/// VisitCall - Transfer function for function calls.
void VisitCallExpr(const CallExpr *CE, ExplodedNode *Pred,
ExplodedNodeSet &Dst);
/// VisitCast - Transfer function logic for all casts (implicit and explicit).
void VisitCast(const CastExpr *CastE, const Expr *Ex, ExplodedNode *Pred,
ExplodedNodeSet &Dst);
/// VisitCompoundLiteralExpr - Transfer function logic for compound literals.
void VisitCompoundLiteralExpr(const CompoundLiteralExpr *CL,
ExplodedNode *Pred, ExplodedNodeSet &Dst);
/// Transfer function logic for DeclRefExprs and BlockDeclRefExprs.
void VisitCommonDeclRefExpr(const Expr *DR, const NamedDecl *D,
ExplodedNode *Pred, ExplodedNodeSet &Dst);
/// VisitDeclStmt - Transfer function logic for DeclStmts.
void VisitDeclStmt(const DeclStmt *DS, ExplodedNode *Pred,
ExplodedNodeSet &Dst);
/// VisitGuardedExpr - Transfer function logic for ?, __builtin_choose
void VisitGuardedExpr(const Expr *Ex, const Expr *L, const Expr *R,
ExplodedNode *Pred, ExplodedNodeSet &Dst);
void VisitInitListExpr(const InitListExpr *E, ExplodedNode *Pred,
ExplodedNodeSet &Dst);
/// VisitLogicalExpr - Transfer function logic for '&&', '||'
void VisitLogicalExpr(const BinaryOperator* B, ExplodedNode *Pred,
ExplodedNodeSet &Dst);
/// VisitMemberExpr - Transfer function for member expressions.
void VisitMemberExpr(const MemberExpr *M, ExplodedNode *Pred,
ExplodedNodeSet &Dst);
/// VisitAtomicExpr - Transfer function for builtin atomic expressions
void VisitAtomicExpr(const AtomicExpr *E, ExplodedNode *Pred,
ExplodedNodeSet &Dst);
/// Transfer function logic for ObjCAtSynchronizedStmts.
void VisitObjCAtSynchronizedStmt(const ObjCAtSynchronizedStmt *S,
ExplodedNode *Pred, ExplodedNodeSet &Dst);
/// Transfer function logic for computing the lvalue of an Objective-C ivar.
void VisitLvalObjCIvarRefExpr(const ObjCIvarRefExpr *DR, ExplodedNode *Pred,
ExplodedNodeSet &Dst);
/// VisitObjCForCollectionStmt - Transfer function logic for
/// ObjCForCollectionStmt.
void VisitObjCForCollectionStmt(const ObjCForCollectionStmt *S,
ExplodedNode *Pred, ExplodedNodeSet &Dst);
void VisitObjCMessage(const ObjCMessageExpr *ME, ExplodedNode *Pred,
ExplodedNodeSet &Dst);
/// VisitReturnStmt - Transfer function logic for return statements.
void VisitReturnStmt(const ReturnStmt *R, ExplodedNode *Pred,
ExplodedNodeSet &Dst);
/// VisitOffsetOfExpr - Transfer function for offsetof.
void VisitOffsetOfExpr(const OffsetOfExpr *Ex, ExplodedNode *Pred,
ExplodedNodeSet &Dst);
/// VisitUnaryExprOrTypeTraitExpr - Transfer function for sizeof.
void VisitUnaryExprOrTypeTraitExpr(const UnaryExprOrTypeTraitExpr *Ex,
ExplodedNode *Pred, ExplodedNodeSet &Dst);
/// VisitUnaryOperator - Transfer function logic for unary operators.
void VisitUnaryOperator(const UnaryOperator* B, ExplodedNode *Pred,
ExplodedNodeSet &Dst);
/// Handle ++ and -- (both pre- and post-increment).
void VisitIncrementDecrementOperator(const UnaryOperator* U,
ExplodedNode *Pred,
ExplodedNodeSet &Dst);
void VisitCXXBindTemporaryExpr(const CXXBindTemporaryExpr *BTE,
ExplodedNodeSet &PreVisit,
ExplodedNodeSet &Dst);
void VisitCXXCatchStmt(const CXXCatchStmt *CS, ExplodedNode *Pred,
ExplodedNodeSet &Dst);
void VisitCXXThisExpr(const CXXThisExpr *TE, ExplodedNode *Pred,
ExplodedNodeSet & Dst);
void VisitCXXConstructExpr(const CXXConstructExpr *E, ExplodedNode *Pred,
ExplodedNodeSet &Dst);
void VisitCXXInheritedCtorInitExpr(const CXXInheritedCtorInitExpr *E,
ExplodedNode *Pred, ExplodedNodeSet &Dst);
void VisitCXXDestructor(QualType ObjectType, const MemRegion *Dest,
const Stmt *S, bool IsBaseDtor,
ExplodedNode *Pred, ExplodedNodeSet &Dst,
EvalCallOptions &Options);
void VisitCXXNewAllocatorCall(const CXXNewExpr *CNE,
ExplodedNode *Pred,
ExplodedNodeSet &Dst);
void VisitCXXNewExpr(const CXXNewExpr *CNE, ExplodedNode *Pred,
ExplodedNodeSet &Dst);
void VisitCXXDeleteExpr(const CXXDeleteExpr *CDE, ExplodedNode *Pred,
ExplodedNodeSet &Dst);
/// Create a C++ temporary object for an rvalue.
void CreateCXXTemporaryObject(const MaterializeTemporaryExpr *ME,
ExplodedNode *Pred,
ExplodedNodeSet &Dst);
/// evalEagerlyAssumeBinOpBifurcation - Given the nodes in 'Src', eagerly assume symbolic
/// expressions of the form 'x != 0' and generate new nodes (stored in Dst)
/// with those assumptions.
void evalEagerlyAssumeBinOpBifurcation(ExplodedNodeSet &Dst, ExplodedNodeSet &Src,
const Expr *Ex);
static std::pair<const ProgramPointTag *, const ProgramPointTag *>
geteagerlyAssumeBinOpBifurcationTags();
ProgramStateRef handleLValueBitCast(ProgramStateRef state, const Expr *Ex,
const LocationContext *LCtx, QualType T,
QualType ExTy, const CastExpr *CastE,
StmtNodeBuilder &Bldr,
ExplodedNode *Pred);
void handleUOExtension(ExplodedNode *N, const UnaryOperator *U,
StmtNodeBuilder &Bldr);
public:
SVal evalBinOp(ProgramStateRef ST, BinaryOperator::Opcode Op,
SVal LHS, SVal RHS, QualType T) {
return svalBuilder.evalBinOp(ST, Op, LHS, RHS, T);
}
/// Retreives which element is being constructed in a non-POD type array.
static std::optional<unsigned>
getIndexOfElementToConstruct(ProgramStateRef State, const CXXConstructExpr *E,
const LocationContext *LCtx);
/// Retreives which element is being destructed in a non-POD type array.
static std::optional<unsigned>
getPendingArrayDestruction(ProgramStateRef State,
const LocationContext *LCtx);
/// Retreives the size of the array in the pending ArrayInitLoopExpr.
static std::optional<unsigned>
getPendingInitLoop(ProgramStateRef State, const CXXConstructExpr *E,
const LocationContext *LCtx);
/// By looking at a certain item that may be potentially part of an object's
/// ConstructionContext, retrieve such object's location. A particular
/// statement can be transparently passed as \p Item in most cases.
static std::optional<SVal>
getObjectUnderConstruction(ProgramStateRef State,
const ConstructionContextItem &Item,
const LocationContext *LC);
/// Call PointerEscape callback when a value escapes as a result of bind.
ProgramStateRef processPointerEscapedOnBind(
ProgramStateRef State, ArrayRef<std::pair<SVal, SVal>> LocAndVals,
const LocationContext *LCtx, PointerEscapeKind Kind,
const CallEvent *Call);
/// Call PointerEscape callback when a value escapes as a result of
/// region invalidation.
/// \param[in] ITraits Specifies invalidation traits for regions/symbols.
ProgramStateRef notifyCheckersOfPointerEscape(
ProgramStateRef State,
const InvalidatedSymbols *Invalidated,
ArrayRef<const MemRegion *> ExplicitRegions,
const CallEvent *Call,
RegionAndSymbolInvalidationTraits &ITraits);
private:
/// evalBind - Handle the semantics of binding a value to a specific location.
/// This method is used by evalStore, VisitDeclStmt, and others.
void evalBind(ExplodedNodeSet &Dst, const Stmt *StoreE, ExplodedNode *Pred,
SVal location, SVal Val, bool atDeclInit = false,
const ProgramPoint *PP = nullptr);
ProgramStateRef
processPointerEscapedOnBind(ProgramStateRef State,
SVal Loc, SVal Val,
const LocationContext *LCtx);
/// A simple wrapper when you only need to notify checkers of pointer-escape
/// of some values.
ProgramStateRef escapeValues(ProgramStateRef State, ArrayRef<SVal> Vs,
PointerEscapeKind K,
const CallEvent *Call = nullptr) const;
public:
// FIXME: 'tag' should be removed, and a LocationContext should be used
// instead.
// FIXME: Comment on the meaning of the arguments, when 'St' may not
// be the same as Pred->state, and when 'location' may not be the
// same as state->getLValue(Ex).
/// Simulate a read of the result of Ex.
void evalLoad(ExplodedNodeSet &Dst,
const Expr *NodeEx, /* Eventually will be a CFGStmt */
const Expr *BoundExpr,
ExplodedNode *Pred,
ProgramStateRef St,
SVal location,
const ProgramPointTag *tag = nullptr,
QualType LoadTy = QualType());
// FIXME: 'tag' should be removed, and a LocationContext should be used
// instead.
void evalStore(ExplodedNodeSet &Dst, const Expr *AssignE, const Expr *StoreE,
ExplodedNode *Pred, ProgramStateRef St, SVal TargetLV, SVal Val,
const ProgramPointTag *tag = nullptr);
/// Return the CFG element corresponding to the worklist element
/// that is currently being processed by ExprEngine.
CFGElement getCurrentCFGElement() {
return (*currBldrCtx->getBlock())[currStmtIdx];
}
/// Create a new state in which the call return value is binded to the
/// call origin expression.
ProgramStateRef bindReturnValue(const CallEvent &Call,
const LocationContext *LCtx,
ProgramStateRef State);
/// Evaluate a call, running pre- and post-call checkers and allowing checkers
/// to be responsible for handling the evaluation of the call itself.
void evalCall(ExplodedNodeSet &Dst, ExplodedNode *Pred,
const CallEvent &Call);
/// Default implementation of call evaluation.
void defaultEvalCall(NodeBuilder &B, ExplodedNode *Pred,
const CallEvent &Call,
const EvalCallOptions &CallOpts = {});
/// Find location of the object that is being constructed by a given
/// constructor. This should ideally always succeed but due to not being
/// fully implemented it sometimes indicates that it failed via its
/// out-parameter CallOpts; in such cases a fake temporary region is
/// returned, which is better than nothing but does not represent
/// the actual behavior of the program. The Idx parameter is used if we
/// construct an array of objects. In that case it points to the index
/// of the continuous memory region.
/// E.g.:
/// For `int arr[4]` this index can be 0,1,2,3.
/// For `int arr2[3][3]` this index can be 0,1,...,7,8.
/// A multi-dimensional array is also a continuous memory location in a
/// row major order, so for arr[0][0] Idx is 0 and for arr[2][2] Idx is 8.
SVal computeObjectUnderConstruction(const Expr *E, ProgramStateRef State,
const NodeBuilderContext *BldrCtx,
const LocationContext *LCtx,
const ConstructionContext *CC,
EvalCallOptions &CallOpts,
unsigned Idx = 0);
/// Update the program state with all the path-sensitive information
/// that's necessary to perform construction of an object with a given
/// syntactic construction context. V and CallOpts have to be obtained from
/// computeObjectUnderConstruction() invoked with the same set of
/// the remaining arguments (E, State, LCtx, CC).
ProgramStateRef updateObjectsUnderConstruction(
SVal V, const Expr *E, ProgramStateRef State, const LocationContext *LCtx,
const ConstructionContext *CC, const EvalCallOptions &CallOpts);
/// A convenient wrapper around computeObjectUnderConstruction
/// and updateObjectsUnderConstruction.
std::pair<ProgramStateRef, SVal> handleConstructionContext(
const Expr *E, ProgramStateRef State, const NodeBuilderContext *BldrCtx,
const LocationContext *LCtx, const ConstructionContext *CC,
EvalCallOptions &CallOpts, unsigned Idx = 0) {
SVal V = computeObjectUnderConstruction(E, State, BldrCtx, LCtx, CC,
CallOpts, Idx);
State = updateObjectsUnderConstruction(V, E, State, LCtx, CC, CallOpts);
return std::make_pair(State, V);
}
private:
ProgramStateRef finishArgumentConstruction(ProgramStateRef State,
const CallEvent &Call);
void finishArgumentConstruction(ExplodedNodeSet &Dst, ExplodedNode *Pred,
const CallEvent &Call);
void evalLocation(ExplodedNodeSet &Dst,
const Stmt *NodeEx, /* This will eventually be a CFGStmt */
const Stmt *BoundEx,
ExplodedNode *Pred,
ProgramStateRef St,
SVal location,
bool isLoad);
/// Count the stack depth and determine if the call is recursive.
void examineStackFrames(const Decl *D, const LocationContext *LCtx,
bool &IsRecursive, unsigned &StackDepth);
enum CallInlinePolicy {
CIP_Allowed,
CIP_DisallowedOnce,
CIP_DisallowedAlways
};
/// See if a particular call should be inlined, by only looking
/// at the call event and the current state of analysis.
CallInlinePolicy mayInlineCallKind(const CallEvent &Call,
const ExplodedNode *Pred,
AnalyzerOptions &Opts,
const EvalCallOptions &CallOpts);
/// See if the given AnalysisDeclContext is built for a function that we
/// should always inline simply because it's small enough.
/// Apart from "small" functions, we also have "large" functions
/// (cf. isLarge()), some of which are huge (cf. isHuge()), and we classify
/// the remaining functions as "medium".
bool isSmall(AnalysisDeclContext *ADC) const;
/// See if the given AnalysisDeclContext is built for a function that we
/// should inline carefully because it looks pretty large.
bool isLarge(AnalysisDeclContext *ADC) const;
/// See if the given AnalysisDeclContext is built for a function that we
/// should never inline because it's legit gigantic.
bool isHuge(AnalysisDeclContext *ADC) const;
/// See if the given AnalysisDeclContext is built for a function that we
/// should inline, just by looking at the declaration of the function.
bool mayInlineDecl(AnalysisDeclContext *ADC) const;
/// Checks our policies and decides weither the given call should be inlined.
bool shouldInlineCall(const CallEvent &Call, const Decl *D,
const ExplodedNode *Pred,
const EvalCallOptions &CallOpts = {});
/// Checks whether our policies allow us to inline a non-POD type array
/// construction.
bool shouldInlineArrayConstruction(const ProgramStateRef State,
const CXXConstructExpr *CE,
const LocationContext *LCtx);
/// Checks whether our policies allow us to inline a non-POD type array
/// destruction.
/// \param Size The size of the array.
bool shouldInlineArrayDestruction(uint64_t Size);
/// Prepares the program state for array destruction. If no error happens
/// the function binds a 'PendingArrayDestruction' entry to the state, which
/// it returns along with the index. If any error happens (we fail to read
/// the size, the index would be -1, etc.) the function will return the
/// original state along with an index of 0. The actual element count of the
/// array can be accessed by the optional 'ElementCountVal' parameter. \param
/// State The program state. \param Region The memory region where the array
/// is stored. \param ElementTy The type an element in the array. \param LCty
/// The location context. \param ElementCountVal A pointer to an optional
/// SVal. If specified, the size of the array will be returned in it. It can
/// be Unknown.
std::pair<ProgramStateRef, uint64_t> prepareStateForArrayDestruction(
const ProgramStateRef State, const MemRegion *Region,
const QualType &ElementTy, const LocationContext *LCtx,
SVal *ElementCountVal = nullptr);
/// Checks whether we construct an array of non-POD type, and decides if the
/// constructor should be inkoved once again.
bool shouldRepeatCtorCall(ProgramStateRef State, const CXXConstructExpr *E,
const LocationContext *LCtx);
void inlineCall(WorkList *WList, const CallEvent &Call, const Decl *D,
NodeBuilder &Bldr, ExplodedNode *Pred, ProgramStateRef State);
void ctuBifurcate(const CallEvent &Call, const Decl *D, NodeBuilder &Bldr,
ExplodedNode *Pred, ProgramStateRef State);
/// Returns true if the CTU analysis is running its second phase.
bool isSecondPhaseCTU() { return IsCTUEnabled && !Engine.getCTUWorkList(); }
/// Conservatively evaluate call by invalidating regions and binding
/// a conjured return value.
void conservativeEvalCall(const CallEvent &Call, NodeBuilder &Bldr,
ExplodedNode *Pred, ProgramStateRef State);
/// Either inline or process the call conservatively (or both), based
/// on DynamicDispatchBifurcation data.
void BifurcateCall(const MemRegion *BifurReg,
const CallEvent &Call, const Decl *D, NodeBuilder &Bldr,
ExplodedNode *Pred);
bool replayWithoutInlining(ExplodedNode *P, const LocationContext *CalleeLC);
/// Models a trivial copy or move constructor or trivial assignment operator
/// call with a simple bind.
void performTrivialCopy(NodeBuilder &Bldr, ExplodedNode *Pred,
const CallEvent &Call);
/// If the value of the given expression \p InitWithAdjustments is a NonLoc,
/// copy it into a new temporary object region, and replace the value of the
/// expression with that.
///
/// If \p Result is provided, the new region will be bound to this expression
/// instead of \p InitWithAdjustments.
///
/// Returns the temporary region with adjustments into the optional
/// OutRegionWithAdjustments out-parameter if a new region was indeed needed,
/// otherwise sets it to nullptr.
ProgramStateRef createTemporaryRegionIfNeeded(
ProgramStateRef State, const LocationContext *LC,
const Expr *InitWithAdjustments, const Expr *Result = nullptr,
const SubRegion **OutRegionWithAdjustments = nullptr);
/// Returns a region representing the `Idx`th element of a (possibly
/// multi-dimensional) array, for the purposes of element construction or
/// destruction.
///
/// On return, \p Ty will be set to the base type of the array.
///
/// If the type is not an array type at all, the original value is returned.
/// Otherwise the "IsArray" flag is set.
static SVal makeElementRegion(ProgramStateRef State, SVal LValue,
QualType &Ty, bool &IsArray, unsigned Idx = 0);
/// Common code that handles either a CXXConstructExpr or a
/// CXXInheritedCtorInitExpr.
void handleConstructor(const Expr *E, ExplodedNode *Pred,
ExplodedNodeSet &Dst);
public:
/// Note whether this loop has any more iteratios to model. These methods are
/// essentially an interface for a GDM trait. Further reading in
/// ExprEngine::VisitObjCForCollectionStmt().
[[nodiscard]] static ProgramStateRef
setWhetherHasMoreIteration(ProgramStateRef State,
const ObjCForCollectionStmt *O,
const LocationContext *LC, bool HasMoreIteraton);
[[nodiscard]] static ProgramStateRef
removeIterationState(ProgramStateRef State, const ObjCForCollectionStmt *O,
const LocationContext *LC);
[[nodiscard]] static bool hasMoreIteration(ProgramStateRef State,
const ObjCForCollectionStmt *O,
const LocationContext *LC);
private:
/// Assuming we construct an array of non-POD types, this method allows us
/// to store which element is to be constructed next.
static ProgramStateRef
setIndexOfElementToConstruct(ProgramStateRef State, const CXXConstructExpr *E,
const LocationContext *LCtx, unsigned Idx);
static ProgramStateRef
removeIndexOfElementToConstruct(ProgramStateRef State,
const CXXConstructExpr *E,
const LocationContext *LCtx);
/// Assuming we destruct an array of non-POD types, this method allows us
/// to store which element is to be destructed next.
static ProgramStateRef setPendingArrayDestruction(ProgramStateRef State,
const LocationContext *LCtx,
unsigned Idx);
static ProgramStateRef
removePendingArrayDestruction(ProgramStateRef State,
const LocationContext *LCtx);
/// Sets the size of the array in a pending ArrayInitLoopExpr.
static ProgramStateRef setPendingInitLoop(ProgramStateRef State,
const CXXConstructExpr *E,
const LocationContext *LCtx,
unsigned Idx);
static ProgramStateRef removePendingInitLoop(ProgramStateRef State,
const CXXConstructExpr *E,
const LocationContext *LCtx);
static ProgramStateRef
removeStateTraitsUsedForArrayEvaluation(ProgramStateRef State,
const CXXConstructExpr *E,
const LocationContext *LCtx);
/// Store the location of a C++ object corresponding to a statement
/// until the statement is actually encountered. For example, if a DeclStmt
/// has CXXConstructExpr as its initializer, the object would be considered
/// to be "under construction" between CXXConstructExpr and DeclStmt.
/// This allows, among other things, to keep bindings to variable's fields
/// made within the constructor alive until its declaration actually
/// goes into scope.
static ProgramStateRef
addObjectUnderConstruction(ProgramStateRef State,
const ConstructionContextItem &Item,
const LocationContext *LC, SVal V);
/// Mark the object sa fully constructed, cleaning up the state trait
/// that tracks objects under construction.
static ProgramStateRef
finishObjectConstruction(ProgramStateRef State,
const ConstructionContextItem &Item,
const LocationContext *LC);
/// If the given expression corresponds to a temporary that was used for
/// passing into an elidable copy/move constructor and that constructor
/// was actually elided, track that we also need to elide the destructor.
static ProgramStateRef elideDestructor(ProgramStateRef State,
const CXXBindTemporaryExpr *BTE,
const LocationContext *LC);
/// Stop tracking the destructor that corresponds to an elided constructor.
static ProgramStateRef
cleanupElidedDestructor(ProgramStateRef State,
const CXXBindTemporaryExpr *BTE,
const LocationContext *LC);
/// Returns true if the given expression corresponds to a temporary that
/// was constructed for passing into an elidable copy/move constructor
/// and that constructor was actually elided.
static bool isDestructorElided(ProgramStateRef State,
const CXXBindTemporaryExpr *BTE,
const LocationContext *LC);
/// Check if all objects under construction have been fully constructed
/// for the given context range (including FromLC, not including ToLC).
/// This is useful for assertions. Also checks if elided destructors
/// were cleaned up.
static bool areAllObjectsFullyConstructed(ProgramStateRef State,
const LocationContext *FromLC,
const LocationContext *ToLC);
};
/// Traits for storing the call processing policy inside GDM.
/// The GDM stores the corresponding CallExpr pointer.
// FIXME: This does not use the nice trait macros because it must be accessible
// from multiple translation units.
struct ReplayWithoutInlining{};
template <>
struct ProgramStateTrait<ReplayWithoutInlining> :
public ProgramStatePartialTrait<const void*> {
static void *GDMIndex();
};
} // namespace ento
} // namespace clang
#endif // LLVM_CLANG_STATICANALYZER_CORE_PATHSENSITIVE_EXPRENGINE_H
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