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llvm-project/clang/lib/StaticAnalyzer/Checkers/ContainerModeling.cpp

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//===-- ContainerModeling.cpp -------------------------------------*- 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
//
//===----------------------------------------------------------------------===//
//
// Defines a modeling-checker for modeling STL container-like containers.
//
//===----------------------------------------------------------------------===//
#include "clang/StaticAnalyzer/Checkers/BuiltinCheckerRegistration.h"
#include "clang/AST/DeclTemplate.h"
#include "clang/Driver/DriverDiagnostic.h"
#include "clang/StaticAnalyzer/Core/BugReporter/BugType.h"
#include "clang/StaticAnalyzer/Core/Checker.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/CallEvent.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/DynamicType.h"
#include "Iterator.h"
#include <utility>
using namespace clang;
using namespace ento;
using namespace iterator;
namespace {
class ContainerModeling
: public Checker<check::PostCall, check::LiveSymbols, check::DeadSymbols> {
void handleBegin(CheckerContext &C, const Expr *CE, SVal RetVal,
SVal Cont) const;
void handleEnd(CheckerContext &C, const Expr *CE, SVal RetVal,
SVal Cont) const;
void handleAssignment(CheckerContext &C, SVal Cont, const Expr *CE = nullptr,
SVal OldCont = UndefinedVal()) const;
void handleAssign(CheckerContext &C, SVal Cont, const Expr *ContE) const;
void handleClear(CheckerContext &C, SVal Cont, const Expr *ContE) const;
void handlePushBack(CheckerContext &C, SVal Cont, const Expr *ContE) const;
void handlePopBack(CheckerContext &C, SVal Cont, const Expr *ContE) const;
void handlePushFront(CheckerContext &C, SVal Cont, const Expr *ContE) const;
void handlePopFront(CheckerContext &C, SVal Cont, const Expr *ContE) const;
void handleInsert(CheckerContext &C, SVal Cont, SVal Iter) const;
void handleErase(CheckerContext &C, SVal Cont, SVal Iter) const;
void handleErase(CheckerContext &C, SVal Cont, SVal Iter1, SVal Iter2) const;
void handleEraseAfter(CheckerContext &C, SVal Cont, SVal Iter) const;
void handleEraseAfter(CheckerContext &C, SVal Cont, SVal Iter1,
SVal Iter2) const;
const NoteTag *getChangeTag(CheckerContext &C, StringRef Text,
const MemRegion *ContReg,
const Expr *ContE) const;
void printState(raw_ostream &Out, ProgramStateRef State, const char *NL,
const char *Sep) const override;
public:
ContainerModeling() = default;
void checkPostCall(const CallEvent &Call, CheckerContext &C) const;
void checkLiveSymbols(ProgramStateRef State, SymbolReaper &SR) const;
void checkDeadSymbols(SymbolReaper &SR, CheckerContext &C) const;
using NoItParamFn = void (ContainerModeling::*)(CheckerContext &, SVal,
const Expr *) const;
using OneItParamFn = void (ContainerModeling::*)(CheckerContext &, SVal,
SVal) const;
using TwoItParamFn = void (ContainerModeling::*)(CheckerContext &, SVal, SVal,
SVal) const;
CallDescriptionMap<NoItParamFn> NoIterParamFunctions = {
{{0, "clear", 0},
&ContainerModeling::handleClear},
{{0, "assign", 2},
&ContainerModeling::handleAssign},
{{0, "push_back", 1},
&ContainerModeling::handlePushBack},
{{0, "emplace_back", 1},
&ContainerModeling::handlePushBack},
{{0, "pop_back", 0},
&ContainerModeling::handlePopBack},
{{0, "push_front", 1},
&ContainerModeling::handlePushFront},
{{0, "emplace_front", 1},
&ContainerModeling::handlePushFront},
{{0, "pop_front", 0},
&ContainerModeling::handlePopFront},
};
CallDescriptionMap<OneItParamFn> OneIterParamFunctions = {
{{0, "insert", 2},
&ContainerModeling::handleInsert},
{{0, "emplace", 2},
&ContainerModeling::handleInsert},
{{0, "erase", 1},
&ContainerModeling::handleErase},
{{0, "erase_after", 1},
&ContainerModeling::handleEraseAfter},
};
CallDescriptionMap<TwoItParamFn> TwoIterParamFunctions = {
{{0, "erase", 2},
&ContainerModeling::handleErase},
{{0, "erase_after", 2},
&ContainerModeling::handleEraseAfter},
};
};
bool isBeginCall(const FunctionDecl *Func);
bool isEndCall(const FunctionDecl *Func);
bool hasSubscriptOperator(ProgramStateRef State, const MemRegion *Reg);
bool frontModifiable(ProgramStateRef State, const MemRegion *Reg);
bool backModifiable(ProgramStateRef State, const MemRegion *Reg);
SymbolRef getContainerBegin(ProgramStateRef State, const MemRegion *Cont);
SymbolRef getContainerEnd(ProgramStateRef State, const MemRegion *Cont);
ProgramStateRef createContainerBegin(ProgramStateRef State,
const MemRegion *Cont, const Expr *E,
QualType T, const LocationContext *LCtx,
unsigned BlockCount);
ProgramStateRef createContainerEnd(ProgramStateRef State, const MemRegion *Cont,
const Expr *E, QualType T,
const LocationContext *LCtx,
unsigned BlockCount);
ProgramStateRef setContainerData(ProgramStateRef State, const MemRegion *Cont,
const ContainerData &CData);
ProgramStateRef invalidateAllIteratorPositions(ProgramStateRef State,
const MemRegion *Cont);
ProgramStateRef
invalidateAllIteratorPositionsExcept(ProgramStateRef State,
const MemRegion *Cont, SymbolRef Offset,
BinaryOperator::Opcode Opc);
ProgramStateRef invalidateIteratorPositions(ProgramStateRef State,
SymbolRef Offset,
BinaryOperator::Opcode Opc);
ProgramStateRef invalidateIteratorPositions(ProgramStateRef State,
SymbolRef Offset1,
BinaryOperator::Opcode Opc1,
SymbolRef Offset2,
BinaryOperator::Opcode Opc2);
ProgramStateRef reassignAllIteratorPositions(ProgramStateRef State,
const MemRegion *Cont,
const MemRegion *NewCont);
ProgramStateRef reassignAllIteratorPositionsUnless(ProgramStateRef State,
const MemRegion *Cont,
const MemRegion *NewCont,
SymbolRef Offset,
BinaryOperator::Opcode Opc);
ProgramStateRef rebaseSymbolInIteratorPositionsIf(
ProgramStateRef State, SValBuilder &SVB, SymbolRef OldSym,
SymbolRef NewSym, SymbolRef CondSym, BinaryOperator::Opcode Opc);
SymbolRef rebaseSymbol(ProgramStateRef State, SValBuilder &SVB, SymbolRef Expr,
SymbolRef OldSym, SymbolRef NewSym);
bool hasLiveIterators(ProgramStateRef State, const MemRegion *Cont);
} // namespace
void ContainerModeling::checkPostCall(const CallEvent &Call,
CheckerContext &C) const {
const auto *Func = dyn_cast_or_null<FunctionDecl>(Call.getDecl());
if (!Func)
return;
if (Func->isOverloadedOperator()) {
const auto Op = Func->getOverloadedOperator();
if (Op == OO_Equal) {
// Overloaded 'operator=' must be a non-static member function.
const auto *InstCall = cast<CXXInstanceCall>(&Call);
if (cast<CXXMethodDecl>(Func)->isMoveAssignmentOperator()) {
handleAssignment(C, InstCall->getCXXThisVal(), Call.getOriginExpr(),
Call.getArgSVal(0));
return;
}
handleAssignment(C, InstCall->getCXXThisVal());
return;
}
} else {
if (const auto *InstCall = dyn_cast<CXXInstanceCall>(&Call)) {
const NoItParamFn *Handler0 = NoIterParamFunctions.lookup(Call);
if (Handler0) {
(this->**Handler0)(C, InstCall->getCXXThisVal(),
InstCall->getCXXThisExpr());
return;
}
const OneItParamFn *Handler1 = OneIterParamFunctions.lookup(Call);
if (Handler1) {
(this->**Handler1)(C, InstCall->getCXXThisVal(), Call.getArgSVal(0));
return;
}
const TwoItParamFn *Handler2 = TwoIterParamFunctions.lookup(Call);
if (Handler2) {
(this->**Handler2)(C, InstCall->getCXXThisVal(), Call.getArgSVal(0),
Call.getArgSVal(1));
return;
}
const auto *OrigExpr = Call.getOriginExpr();
if (!OrigExpr)
return;
if (isBeginCall(Func)) {
handleBegin(C, OrigExpr, Call.getReturnValue(),
InstCall->getCXXThisVal());
return;
}
if (isEndCall(Func)) {
handleEnd(C, OrigExpr, Call.getReturnValue(),
InstCall->getCXXThisVal());
return;
}
}
}
}
void ContainerModeling::checkLiveSymbols(ProgramStateRef State,
SymbolReaper &SR) const {
// Keep symbolic expressions of container begins and ends alive
auto ContMap = State->get<ContainerMap>();
for (const auto &Cont : ContMap) {
const auto CData = Cont.second;
if (CData.getBegin()) {
SR.markLive(CData.getBegin());
if(const auto *SIE = dyn_cast<SymIntExpr>(CData.getBegin()))
SR.markLive(SIE->getLHS());
}
if (CData.getEnd()) {
SR.markLive(CData.getEnd());
if(const auto *SIE = dyn_cast<SymIntExpr>(CData.getEnd()))
SR.markLive(SIE->getLHS());
}
}
}
void ContainerModeling::checkDeadSymbols(SymbolReaper &SR,
CheckerContext &C) const {
// Cleanup
auto State = C.getState();
auto ContMap = State->get<ContainerMap>();
for (const auto &Cont : ContMap) {
if (!SR.isLiveRegion(Cont.first)) {
// We must keep the container data while it has live iterators to be able
// to compare them to the begin and the end of the container.
if (!hasLiveIterators(State, Cont.first)) {
State = State->remove<ContainerMap>(Cont.first);
}
}
}
C.addTransition(State);
}
void ContainerModeling::handleBegin(CheckerContext &C, const Expr *CE,
SVal RetVal, SVal Cont) const {
const auto *ContReg = Cont.getAsRegion();
if (!ContReg)
return;
ContReg = ContReg->getMostDerivedObjectRegion();
// If the container already has a begin symbol then use it. Otherwise first
// create a new one.
auto State = C.getState();
auto BeginSym = getContainerBegin(State, ContReg);
if (!BeginSym) {
State = createContainerBegin(State, ContReg, CE, C.getASTContext().LongTy,
C.getLocationContext(), C.blockCount());
BeginSym = getContainerBegin(State, ContReg);
}
State = setIteratorPosition(State, RetVal,
IteratorPosition::getPosition(ContReg, BeginSym));
C.addTransition(State);
}
void ContainerModeling::handleEnd(CheckerContext &C, const Expr *CE,
SVal RetVal, SVal Cont) const {
const auto *ContReg = Cont.getAsRegion();
if (!ContReg)
return;
ContReg = ContReg->getMostDerivedObjectRegion();
// If the container already has an end symbol then use it. Otherwise first
// create a new one.
auto State = C.getState();
auto EndSym = getContainerEnd(State, ContReg);
if (!EndSym) {
State = createContainerEnd(State, ContReg, CE, C.getASTContext().LongTy,
C.getLocationContext(), C.blockCount());
EndSym = getContainerEnd(State, ContReg);
}
State = setIteratorPosition(State, RetVal,
IteratorPosition::getPosition(ContReg, EndSym));
C.addTransition(State);
}
void ContainerModeling::handleAssignment(CheckerContext &C, SVal Cont,
const Expr *CE, SVal OldCont) const {
const auto *ContReg = Cont.getAsRegion();
if (!ContReg)
return;
ContReg = ContReg->getMostDerivedObjectRegion();
// Assignment of a new value to a container always invalidates all its
// iterators
auto State = C.getState();
const auto CData = getContainerData(State, ContReg);
if (CData) {
State = invalidateAllIteratorPositions(State, ContReg);
}
// In case of move, iterators of the old container (except the past-end
// iterators) remain valid but refer to the new container
if (!OldCont.isUndef()) {
const auto *OldContReg = OldCont.getAsRegion();
if (OldContReg) {
OldContReg = OldContReg->getMostDerivedObjectRegion();
const auto OldCData = getContainerData(State, OldContReg);
if (OldCData) {
if (const auto OldEndSym = OldCData->getEnd()) {
// If we already assigned an "end" symbol to the old container, then
// first reassign all iterator positions to the new container which
// are not past the container (thus not greater or equal to the
// current "end" symbol).
State = reassignAllIteratorPositionsUnless(State, OldContReg, ContReg,
OldEndSym, BO_GE);
auto &SymMgr = C.getSymbolManager();
auto &SVB = C.getSValBuilder();
// Then generate and assign a new "end" symbol for the new container.
auto NewEndSym =
SymMgr.conjureSymbol(CE, C.getLocationContext(),
C.getASTContext().LongTy, C.blockCount());
State = assumeNoOverflow(State, NewEndSym, 4);
if (CData) {
State = setContainerData(State, ContReg, CData->newEnd(NewEndSym));
} else {
State = setContainerData(State, ContReg,
ContainerData::fromEnd(NewEndSym));
}
// Finally, replace the old "end" symbol in the already reassigned
// iterator positions with the new "end" symbol.
State = rebaseSymbolInIteratorPositionsIf(
State, SVB, OldEndSym, NewEndSym, OldEndSym, BO_LT);
} else {
// There was no "end" symbol assigned yet to the old container,
// so reassign all iterator positions to the new container.
State = reassignAllIteratorPositions(State, OldContReg, ContReg);
}
if (const auto OldBeginSym = OldCData->getBegin()) {
// If we already assigned a "begin" symbol to the old container, then
// assign it to the new container and remove it from the old one.
if (CData) {
State =
setContainerData(State, ContReg, CData->newBegin(OldBeginSym));
} else {
State = setContainerData(State, ContReg,
ContainerData::fromBegin(OldBeginSym));
}
State =
setContainerData(State, OldContReg, OldCData->newBegin(nullptr));
}
} else {
// There was neither "begin" nor "end" symbol assigned yet to the old
// container, so reassign all iterator positions to the new container.
State = reassignAllIteratorPositions(State, OldContReg, ContReg);
}
}
}
C.addTransition(State);
}
void ContainerModeling::handleAssign(CheckerContext &C, SVal Cont,
const Expr *ContE) const {
const auto *ContReg = Cont.getAsRegion();
if (!ContReg)
return;
ContReg = ContReg->getMostDerivedObjectRegion();
// The assign() operation invalidates all the iterators
auto State = C.getState();
State = invalidateAllIteratorPositions(State, ContReg);
C.addTransition(State);
}
void ContainerModeling::handleClear(CheckerContext &C, SVal Cont,
const Expr *ContE) const {
const auto *ContReg = Cont.getAsRegion();
if (!ContReg)
return;
ContReg = ContReg->getMostDerivedObjectRegion();
// The clear() operation invalidates all the iterators, except the past-end
// iterators of list-like containers
auto State = C.getState();
if (!hasSubscriptOperator(State, ContReg) ||
!backModifiable(State, ContReg)) {
const auto CData = getContainerData(State, ContReg);
if (CData) {
if (const auto EndSym = CData->getEnd()) {
State =
invalidateAllIteratorPositionsExcept(State, ContReg, EndSym, BO_GE);
C.addTransition(State);
return;
}
}
}
const NoteTag *ChangeTag =
getChangeTag(C, "became empty", ContReg, ContE);
State = invalidateAllIteratorPositions(State, ContReg);
C.addTransition(State, ChangeTag);
}
void ContainerModeling::handlePushBack(CheckerContext &C, SVal Cont,
const Expr *ContE) const {
const auto *ContReg = Cont.getAsRegion();
if (!ContReg)
return;
ContReg = ContReg->getMostDerivedObjectRegion();
// For deque-like containers invalidate all iterator positions
auto State = C.getState();
if (hasSubscriptOperator(State, ContReg) && frontModifiable(State, ContReg)) {
State = invalidateAllIteratorPositions(State, ContReg);
C.addTransition(State);
return;
}
const auto CData = getContainerData(State, ContReg);
if (!CData)
return;
// For vector-like containers invalidate the past-end iterator positions
if (const auto EndSym = CData->getEnd()) {
if (hasSubscriptOperator(State, ContReg)) {
State = invalidateIteratorPositions(State, EndSym, BO_GE);
}
auto &SymMgr = C.getSymbolManager();
auto &BVF = SymMgr.getBasicVals();
auto &SVB = C.getSValBuilder();
const auto newEndSym =
SVB.evalBinOp(State, BO_Add,
nonloc::SymbolVal(EndSym),
nonloc::ConcreteInt(BVF.getValue(llvm::APSInt::get(1))),
SymMgr.getType(EndSym)).getAsSymbol();
const NoteTag *ChangeTag =
getChangeTag(C, "extended to the back by 1 position", ContReg, ContE);
State = setContainerData(State, ContReg, CData->newEnd(newEndSym));
C.addTransition(State, ChangeTag);
}
}
void ContainerModeling::handlePopBack(CheckerContext &C, SVal Cont,
const Expr *ContE) const {
const auto *ContReg = Cont.getAsRegion();
if (!ContReg)
return;
ContReg = ContReg->getMostDerivedObjectRegion();
auto State = C.getState();
const auto CData = getContainerData(State, ContReg);
if (!CData)
return;
if (const auto EndSym = CData->getEnd()) {
auto &SymMgr = C.getSymbolManager();
auto &BVF = SymMgr.getBasicVals();
auto &SVB = C.getSValBuilder();
const auto BackSym =
SVB.evalBinOp(State, BO_Sub,
nonloc::SymbolVal(EndSym),
nonloc::ConcreteInt(BVF.getValue(llvm::APSInt::get(1))),
SymMgr.getType(EndSym)).getAsSymbol();
const NoteTag *ChangeTag =
getChangeTag(C, "shrank from the back by 1 position", ContReg, ContE);
// For vector-like and deque-like containers invalidate the last and the
// past-end iterator positions. For list-like containers only invalidate
// the last position
if (hasSubscriptOperator(State, ContReg) &&
backModifiable(State, ContReg)) {
State = invalidateIteratorPositions(State, BackSym, BO_GE);
State = setContainerData(State, ContReg, CData->newEnd(nullptr));
} else {
State = invalidateIteratorPositions(State, BackSym, BO_EQ);
}
auto newEndSym = BackSym;
State = setContainerData(State, ContReg, CData->newEnd(newEndSym));
C.addTransition(State, ChangeTag);
}
}
void ContainerModeling::handlePushFront(CheckerContext &C, SVal Cont,
const Expr *ContE) const {
const auto *ContReg = Cont.getAsRegion();
if (!ContReg)
return;
ContReg = ContReg->getMostDerivedObjectRegion();
// For deque-like containers invalidate all iterator positions
auto State = C.getState();
if (hasSubscriptOperator(State, ContReg)) {
State = invalidateAllIteratorPositions(State, ContReg);
C.addTransition(State);
} else {
const auto CData = getContainerData(State, ContReg);
if (!CData)
return;
if (const auto BeginSym = CData->getBegin()) {
auto &SymMgr = C.getSymbolManager();
auto &BVF = SymMgr.getBasicVals();
auto &SVB = C.getSValBuilder();
const auto newBeginSym =
SVB.evalBinOp(State, BO_Sub,
nonloc::SymbolVal(BeginSym),
nonloc::ConcreteInt(BVF.getValue(llvm::APSInt::get(1))),
SymMgr.getType(BeginSym)).getAsSymbol();
const NoteTag *ChangeTag =
getChangeTag(C, "extended to the front by 1 position", ContReg, ContE);
State = setContainerData(State, ContReg, CData->newBegin(newBeginSym));
C.addTransition(State, ChangeTag);
}
}
}
void ContainerModeling::handlePopFront(CheckerContext &C, SVal Cont,
const Expr *ContE) const {
const auto *ContReg = Cont.getAsRegion();
if (!ContReg)
return;
ContReg = ContReg->getMostDerivedObjectRegion();
auto State = C.getState();
const auto CData = getContainerData(State, ContReg);
if (!CData)
return;
// For deque-like containers invalidate all iterator positions. For list-like
// iterators only invalidate the first position
if (const auto BeginSym = CData->getBegin()) {
if (hasSubscriptOperator(State, ContReg)) {
State = invalidateIteratorPositions(State, BeginSym, BO_LE);
} else {
State = invalidateIteratorPositions(State, BeginSym, BO_EQ);
}
auto &SymMgr = C.getSymbolManager();
auto &BVF = SymMgr.getBasicVals();
auto &SVB = C.getSValBuilder();
const auto newBeginSym =
SVB.evalBinOp(State, BO_Add,
nonloc::SymbolVal(BeginSym),
nonloc::ConcreteInt(BVF.getValue(llvm::APSInt::get(1))),
SymMgr.getType(BeginSym)).getAsSymbol();
const NoteTag *ChangeTag =
getChangeTag(C, "shrank from the front by 1 position", ContReg, ContE);
State = setContainerData(State, ContReg, CData->newBegin(newBeginSym));
C.addTransition(State, ChangeTag);
}
}
void ContainerModeling::handleInsert(CheckerContext &C, SVal Cont,
SVal Iter) const {
const auto *ContReg = Cont.getAsRegion();
if (!ContReg)
return;
ContReg = ContReg->getMostDerivedObjectRegion();
auto State = C.getState();
const auto *Pos = getIteratorPosition(State, Iter);
if (!Pos)
return;
// For deque-like containers invalidate all iterator positions. For
// vector-like containers invalidate iterator positions after the insertion.
if (hasSubscriptOperator(State, ContReg) && backModifiable(State, ContReg)) {
if (frontModifiable(State, ContReg)) {
State = invalidateAllIteratorPositions(State, ContReg);
} else {
State = invalidateIteratorPositions(State, Pos->getOffset(), BO_GE);
}
if (const auto *CData = getContainerData(State, ContReg)) {
if (const auto EndSym = CData->getEnd()) {
State = invalidateIteratorPositions(State, EndSym, BO_GE);
State = setContainerData(State, ContReg, CData->newEnd(nullptr));
}
}
C.addTransition(State);
}
}
void ContainerModeling::handleErase(CheckerContext &C, SVal Cont,
SVal Iter) const {
const auto *ContReg = Cont.getAsRegion();
if (!ContReg)
return;
ContReg = ContReg->getMostDerivedObjectRegion();
auto State = C.getState();
const auto *Pos = getIteratorPosition(State, Iter);
if (!Pos)
return;
// For deque-like containers invalidate all iterator positions. For
// vector-like containers invalidate iterator positions at and after the
// deletion. For list-like containers only invalidate the deleted position.
if (hasSubscriptOperator(State, ContReg) && backModifiable(State, ContReg)) {
if (frontModifiable(State, ContReg)) {
State = invalidateAllIteratorPositions(State, ContReg);
} else {
State = invalidateIteratorPositions(State, Pos->getOffset(), BO_GE);
}
if (const auto *CData = getContainerData(State, ContReg)) {
if (const auto EndSym = CData->getEnd()) {
State = invalidateIteratorPositions(State, EndSym, BO_GE);
State = setContainerData(State, ContReg, CData->newEnd(nullptr));
}
}
} else {
State = invalidateIteratorPositions(State, Pos->getOffset(), BO_EQ);
}
C.addTransition(State);
}
void ContainerModeling::handleErase(CheckerContext &C, SVal Cont, SVal Iter1,
SVal Iter2) const {
const auto *ContReg = Cont.getAsRegion();
if (!ContReg)
return;
ContReg = ContReg->getMostDerivedObjectRegion();
auto State = C.getState();
const auto *Pos1 = getIteratorPosition(State, Iter1);
const auto *Pos2 = getIteratorPosition(State, Iter2);
if (!Pos1 || !Pos2)
return;
// For deque-like containers invalidate all iterator positions. For
// vector-like containers invalidate iterator positions at and after the
// deletion range. For list-like containers only invalidate the deleted
// position range [first..last].
if (hasSubscriptOperator(State, ContReg) && backModifiable(State, ContReg)) {
if (frontModifiable(State, ContReg)) {
State = invalidateAllIteratorPositions(State, ContReg);
} else {
State = invalidateIteratorPositions(State, Pos1->getOffset(), BO_GE);
}
if (const auto *CData = getContainerData(State, ContReg)) {
if (const auto EndSym = CData->getEnd()) {
State = invalidateIteratorPositions(State, EndSym, BO_GE);
State = setContainerData(State, ContReg, CData->newEnd(nullptr));
}
}
} else {
State = invalidateIteratorPositions(State, Pos1->getOffset(), BO_GE,
Pos2->getOffset(), BO_LT);
}
C.addTransition(State);
}
void ContainerModeling::handleEraseAfter(CheckerContext &C, SVal Cont,
SVal Iter) const {
auto State = C.getState();
const auto *Pos = getIteratorPosition(State, Iter);
if (!Pos)
return;
// Invalidate the deleted iterator position, which is the position of the
// parameter plus one.
auto &SymMgr = C.getSymbolManager();
auto &BVF = SymMgr.getBasicVals();
auto &SVB = C.getSValBuilder();
const auto NextSym =
SVB.evalBinOp(State, BO_Add,
nonloc::SymbolVal(Pos->getOffset()),
nonloc::ConcreteInt(BVF.getValue(llvm::APSInt::get(1))),
SymMgr.getType(Pos->getOffset())).getAsSymbol();
State = invalidateIteratorPositions(State, NextSym, BO_EQ);
C.addTransition(State);
}
void ContainerModeling::handleEraseAfter(CheckerContext &C, SVal Cont,
SVal Iter1, SVal Iter2) const {
auto State = C.getState();
const auto *Pos1 = getIteratorPosition(State, Iter1);
const auto *Pos2 = getIteratorPosition(State, Iter2);
if (!Pos1 || !Pos2)
return;
// Invalidate the deleted iterator position range (first..last)
State = invalidateIteratorPositions(State, Pos1->getOffset(), BO_GT,
Pos2->getOffset(), BO_LT);
C.addTransition(State);
}
const NoteTag *ContainerModeling::getChangeTag(CheckerContext &C,
StringRef Text,
const MemRegion *ContReg,
const Expr *ContE) const {
StringRef Name;
// First try to get the name of the variable from the region
if (const auto *DR = dyn_cast<DeclRegion>(ContReg)) {
Name = DR->getDecl()->getName();
// If the region is not a `DeclRegion` then use the expression instead
} else if (const auto *DRE =
dyn_cast<DeclRefExpr>(ContE->IgnoreParenCasts())) {
Name = DRE->getDecl()->getName();
}
return C.getNoteTag(
[Text, Name, ContReg](PathSensitiveBugReport &BR) -> std::string {
if (!BR.isInteresting(ContReg))
return "";
SmallString<256> Msg;
llvm::raw_svector_ostream Out(Msg);
Out << "Container " << (!Name.empty() ? ("'" + Name.str() + "' ") : "" )
<< Text;
return std::string(Out.str());
});
}
void ContainerModeling::printState(raw_ostream &Out, ProgramStateRef State,
const char *NL, const char *Sep) const {
auto ContMap = State->get<ContainerMap>();
if (!ContMap.isEmpty()) {
Out << Sep << "Container Data :" << NL;
for (const auto &Cont : ContMap) {
Cont.first->dumpToStream(Out);
Out << " : [ ";
const auto CData = Cont.second;
if (CData.getBegin())
CData.getBegin()->dumpToStream(Out);
else
Out << "<Unknown>";
Out << " .. ";
if (CData.getEnd())
CData.getEnd()->dumpToStream(Out);
else
Out << "<Unknown>";
Out << " ]";
}
}
}
namespace {
bool isBeginCall(const FunctionDecl *Func) {
const auto *IdInfo = Func->getIdentifier();
if (!IdInfo)
return false;
return IdInfo->getName().endswith_lower("begin");
}
bool isEndCall(const FunctionDecl *Func) {
const auto *IdInfo = Func->getIdentifier();
if (!IdInfo)
return false;
return IdInfo->getName().endswith_lower("end");
}
const CXXRecordDecl *getCXXRecordDecl(ProgramStateRef State,
const MemRegion *Reg) {
auto TI = getDynamicTypeInfo(State, Reg);
if (!TI.isValid())
return nullptr;
auto Type = TI.getType();
if (const auto *RefT = Type->getAs<ReferenceType>()) {
Type = RefT->getPointeeType();
}
return Type->getUnqualifiedDesugaredType()->getAsCXXRecordDecl();
}
bool hasSubscriptOperator(ProgramStateRef State, const MemRegion *Reg) {
const auto *CRD = getCXXRecordDecl(State, Reg);
if (!CRD)
return false;
for (const auto *Method : CRD->methods()) {
if (!Method->isOverloadedOperator())
continue;
const auto OPK = Method->getOverloadedOperator();
if (OPK == OO_Subscript) {
return true;
}
}
return false;
}
bool frontModifiable(ProgramStateRef State, const MemRegion *Reg) {
const auto *CRD = getCXXRecordDecl(State, Reg);
if (!CRD)
return false;
for (const auto *Method : CRD->methods()) {
if (!Method->getDeclName().isIdentifier())
continue;
if (Method->getName() == "push_front" || Method->getName() == "pop_front") {
return true;
}
}
return false;
}
bool backModifiable(ProgramStateRef State, const MemRegion *Reg) {
const auto *CRD = getCXXRecordDecl(State, Reg);
if (!CRD)
return false;
for (const auto *Method : CRD->methods()) {
if (!Method->getDeclName().isIdentifier())
continue;
if (Method->getName() == "push_back" || Method->getName() == "pop_back") {
return true;
}
}
return false;
}
SymbolRef getContainerBegin(ProgramStateRef State, const MemRegion *Cont) {
const auto *CDataPtr = getContainerData(State, Cont);
if (!CDataPtr)
return nullptr;
return CDataPtr->getBegin();
}
SymbolRef getContainerEnd(ProgramStateRef State, const MemRegion *Cont) {
const auto *CDataPtr = getContainerData(State, Cont);
if (!CDataPtr)
return nullptr;
return CDataPtr->getEnd();
}
ProgramStateRef createContainerBegin(ProgramStateRef State,
const MemRegion *Cont, const Expr *E,
QualType T, const LocationContext *LCtx,
unsigned BlockCount) {
// Only create if it does not exist
const auto *CDataPtr = getContainerData(State, Cont);
if (CDataPtr && CDataPtr->getBegin())
return State;
auto &SymMgr = State->getSymbolManager();
const SymbolConjured *Sym = SymMgr.conjureSymbol(E, LCtx, T, BlockCount,
"begin");
State = assumeNoOverflow(State, Sym, 4);
if (CDataPtr) {
const auto CData = CDataPtr->newBegin(Sym);
return setContainerData(State, Cont, CData);
}
const auto CData = ContainerData::fromBegin(Sym);
return setContainerData(State, Cont, CData);
}
ProgramStateRef createContainerEnd(ProgramStateRef State, const MemRegion *Cont,
const Expr *E, QualType T,
const LocationContext *LCtx,
unsigned BlockCount) {
// Only create if it does not exist
const auto *CDataPtr = getContainerData(State, Cont);
if (CDataPtr && CDataPtr->getEnd())
return State;
auto &SymMgr = State->getSymbolManager();
const SymbolConjured *Sym = SymMgr.conjureSymbol(E, LCtx, T, BlockCount,
"end");
State = assumeNoOverflow(State, Sym, 4);
if (CDataPtr) {
const auto CData = CDataPtr->newEnd(Sym);
return setContainerData(State, Cont, CData);
}
const auto CData = ContainerData::fromEnd(Sym);
return setContainerData(State, Cont, CData);
}
ProgramStateRef setContainerData(ProgramStateRef State, const MemRegion *Cont,
const ContainerData &CData) {
return State->set<ContainerMap>(Cont, CData);
}
template <typename Condition, typename Process>
ProgramStateRef processIteratorPositions(ProgramStateRef State, Condition Cond,
Process Proc) {
auto &RegionMapFactory = State->get_context<IteratorRegionMap>();
auto RegionMap = State->get<IteratorRegionMap>();
bool Changed = false;
for (const auto &Reg : RegionMap) {
if (Cond(Reg.second)) {
RegionMap = RegionMapFactory.add(RegionMap, Reg.first, Proc(Reg.second));
Changed = true;
}
}
if (Changed)
State = State->set<IteratorRegionMap>(RegionMap);
auto &SymbolMapFactory = State->get_context<IteratorSymbolMap>();
auto SymbolMap = State->get<IteratorSymbolMap>();
Changed = false;
for (const auto &Sym : SymbolMap) {
if (Cond(Sym.second)) {
SymbolMap = SymbolMapFactory.add(SymbolMap, Sym.first, Proc(Sym.second));
Changed = true;
}
}
if (Changed)
State = State->set<IteratorSymbolMap>(SymbolMap);
return State;
}
ProgramStateRef invalidateAllIteratorPositions(ProgramStateRef State,
const MemRegion *Cont) {
auto MatchCont = [&](const IteratorPosition &Pos) {
return Pos.getContainer() == Cont;
};
auto Invalidate = [&](const IteratorPosition &Pos) {
return Pos.invalidate();
};
return processIteratorPositions(State, MatchCont, Invalidate);
}
ProgramStateRef
invalidateAllIteratorPositionsExcept(ProgramStateRef State,
const MemRegion *Cont, SymbolRef Offset,
BinaryOperator::Opcode Opc) {
auto MatchContAndCompare = [&](const IteratorPosition &Pos) {
return Pos.getContainer() == Cont &&
!compare(State, Pos.getOffset(), Offset, Opc);
};
auto Invalidate = [&](const IteratorPosition &Pos) {
return Pos.invalidate();
};
return processIteratorPositions(State, MatchContAndCompare, Invalidate);
}
ProgramStateRef invalidateIteratorPositions(ProgramStateRef State,
SymbolRef Offset,
BinaryOperator::Opcode Opc) {
auto Compare = [&](const IteratorPosition &Pos) {
return compare(State, Pos.getOffset(), Offset, Opc);
};
auto Invalidate = [&](const IteratorPosition &Pos) {
return Pos.invalidate();
};
return processIteratorPositions(State, Compare, Invalidate);
}
ProgramStateRef invalidateIteratorPositions(ProgramStateRef State,
SymbolRef Offset1,
BinaryOperator::Opcode Opc1,
SymbolRef Offset2,
BinaryOperator::Opcode Opc2) {
auto Compare = [&](const IteratorPosition &Pos) {
return compare(State, Pos.getOffset(), Offset1, Opc1) &&
compare(State, Pos.getOffset(), Offset2, Opc2);
};
auto Invalidate = [&](const IteratorPosition &Pos) {
return Pos.invalidate();
};
return processIteratorPositions(State, Compare, Invalidate);
}
ProgramStateRef reassignAllIteratorPositions(ProgramStateRef State,
const MemRegion *Cont,
const MemRegion *NewCont) {
auto MatchCont = [&](const IteratorPosition &Pos) {
return Pos.getContainer() == Cont;
};
auto ReAssign = [&](const IteratorPosition &Pos) {
return Pos.reAssign(NewCont);
};
return processIteratorPositions(State, MatchCont, ReAssign);
}
ProgramStateRef reassignAllIteratorPositionsUnless(ProgramStateRef State,
const MemRegion *Cont,
const MemRegion *NewCont,
SymbolRef Offset,
BinaryOperator::Opcode Opc) {
auto MatchContAndCompare = [&](const IteratorPosition &Pos) {
return Pos.getContainer() == Cont &&
!compare(State, Pos.getOffset(), Offset, Opc);
};
auto ReAssign = [&](const IteratorPosition &Pos) {
return Pos.reAssign(NewCont);
};
return processIteratorPositions(State, MatchContAndCompare, ReAssign);
}
// This function rebases symbolic expression `OldSym + Int` to `NewSym + Int`,
// `OldSym - Int` to `NewSym - Int` and `OldSym` to `NewSym` in any iterator
// position offsets where `CondSym` is true.
ProgramStateRef rebaseSymbolInIteratorPositionsIf(
ProgramStateRef State, SValBuilder &SVB, SymbolRef OldSym,
SymbolRef NewSym, SymbolRef CondSym, BinaryOperator::Opcode Opc) {
auto LessThanEnd = [&](const IteratorPosition &Pos) {
return compare(State, Pos.getOffset(), CondSym, Opc);
};
auto RebaseSymbol = [&](const IteratorPosition &Pos) {
return Pos.setTo(rebaseSymbol(State, SVB, Pos.getOffset(), OldSym,
NewSym));
};
return processIteratorPositions(State, LessThanEnd, RebaseSymbol);
}
// This function rebases symbolic expression `OldExpr + Int` to `NewExpr + Int`,
// `OldExpr - Int` to `NewExpr - Int` and `OldExpr` to `NewExpr` in expression
// `OrigExpr`.
SymbolRef rebaseSymbol(ProgramStateRef State, SValBuilder &SVB,
SymbolRef OrigExpr, SymbolRef OldExpr,
SymbolRef NewSym) {
auto &SymMgr = SVB.getSymbolManager();
auto Diff = SVB.evalBinOpNN(State, BO_Sub, nonloc::SymbolVal(OrigExpr),
nonloc::SymbolVal(OldExpr),
SymMgr.getType(OrigExpr));
const auto DiffInt = Diff.getAs<nonloc::ConcreteInt>();
if (!DiffInt)
return OrigExpr;
return SVB.evalBinOpNN(State, BO_Add, *DiffInt, nonloc::SymbolVal(NewSym),
SymMgr.getType(OrigExpr)).getAsSymbol();
}
bool hasLiveIterators(ProgramStateRef State, const MemRegion *Cont) {
auto RegionMap = State->get<IteratorRegionMap>();
for (const auto &Reg : RegionMap) {
if (Reg.second.getContainer() == Cont)
return true;
}
auto SymbolMap = State->get<IteratorSymbolMap>();
for (const auto &Sym : SymbolMap) {
if (Sym.second.getContainer() == Cont)
return true;
}
return false;
}
} // namespace
void ento::registerContainerModeling(CheckerManager &mgr) {
mgr.registerChecker<ContainerModeling>();
}
bool ento::shouldRegisterContainerModeling(const CheckerManager &mgr) {
if (!mgr.getLangOpts().CPlusPlus)
return false;
if (!mgr.getAnalyzerOptions().ShouldAggressivelySimplifyBinaryOperation) {
mgr.getASTContext().getDiagnostics().Report(
diag::err_analyzer_checker_incompatible_analyzer_option)
<< "aggressive-binary-operation-simplification" << "false";
return false;
}
return true;
}
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