CStringChecker.cpp [plain text]
#include "ClangSACheckers.h"
#include "InterCheckerAPI.h"
#include "clang/StaticAnalyzer/Core/Checker.h"
#include "clang/StaticAnalyzer/Core/CheckerManager.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h"
#include "clang/StaticAnalyzer/Core/BugReporter/BugType.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/ProgramStateTrait.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/StringSwitch.h"
using namespace clang;
using namespace ento;
namespace {
class CStringChecker : public Checker< eval::Call,
check::PreStmt<DeclStmt>,
check::LiveSymbols,
check::DeadSymbols,
check::RegionChanges
> {
mutable OwningPtr<BugType> BT_Null,
BT_Bounds,
BT_Overlap,
BT_NotCString,
BT_AdditionOverflow;
mutable const char *CurrentFunctionDescription;
public:
struct CStringChecksFilter {
DefaultBool CheckCStringNullArg;
DefaultBool CheckCStringOutOfBounds;
DefaultBool CheckCStringBufferOverlap;
DefaultBool CheckCStringNotNullTerm;
};
CStringChecksFilter Filter;
static void *getTag() { static int tag; return &tag; }
bool evalCall(const CallExpr *CE, CheckerContext &C) const;
void checkPreStmt(const DeclStmt *DS, CheckerContext &C) const;
void checkLiveSymbols(ProgramStateRef state, SymbolReaper &SR) const;
void checkDeadSymbols(SymbolReaper &SR, CheckerContext &C) const;
bool wantsRegionChangeUpdate(ProgramStateRef state) const;
ProgramStateRef
checkRegionChanges(ProgramStateRef state,
const StoreManager::InvalidatedSymbols *,
ArrayRef<const MemRegion *> ExplicitRegions,
ArrayRef<const MemRegion *> Regions,
const CallEvent *Call) const;
typedef void (CStringChecker::*FnCheck)(CheckerContext &,
const CallExpr *) const;
void evalMemcpy(CheckerContext &C, const CallExpr *CE) const;
void evalMempcpy(CheckerContext &C, const CallExpr *CE) const;
void evalMemmove(CheckerContext &C, const CallExpr *CE) const;
void evalBcopy(CheckerContext &C, const CallExpr *CE) const;
void evalCopyCommon(CheckerContext &C, const CallExpr *CE,
ProgramStateRef state,
const Expr *Size,
const Expr *Source,
const Expr *Dest,
bool Restricted = false,
bool IsMempcpy = false) const;
void evalMemcmp(CheckerContext &C, const CallExpr *CE) const;
void evalstrLength(CheckerContext &C, const CallExpr *CE) const;
void evalstrnLength(CheckerContext &C, const CallExpr *CE) const;
void evalstrLengthCommon(CheckerContext &C,
const CallExpr *CE,
bool IsStrnlen = false) const;
void evalStrcpy(CheckerContext &C, const CallExpr *CE) const;
void evalStrncpy(CheckerContext &C, const CallExpr *CE) const;
void evalStpcpy(CheckerContext &C, const CallExpr *CE) const;
void evalStrcpyCommon(CheckerContext &C,
const CallExpr *CE,
bool returnEnd,
bool isBounded,
bool isAppending) const;
void evalStrcat(CheckerContext &C, const CallExpr *CE) const;
void evalStrncat(CheckerContext &C, const CallExpr *CE) const;
void evalStrcmp(CheckerContext &C, const CallExpr *CE) const;
void evalStrncmp(CheckerContext &C, const CallExpr *CE) const;
void evalStrcasecmp(CheckerContext &C, const CallExpr *CE) const;
void evalStrncasecmp(CheckerContext &C, const CallExpr *CE) const;
void evalStrcmpCommon(CheckerContext &C,
const CallExpr *CE,
bool isBounded = false,
bool ignoreCase = false) const;
std::pair<ProgramStateRef , ProgramStateRef >
static assumeZero(CheckerContext &C,
ProgramStateRef state, SVal V, QualType Ty);
static ProgramStateRef setCStringLength(ProgramStateRef state,
const MemRegion *MR,
SVal strLength);
static SVal getCStringLengthForRegion(CheckerContext &C,
ProgramStateRef &state,
const Expr *Ex,
const MemRegion *MR,
bool hypothetical);
SVal getCStringLength(CheckerContext &C,
ProgramStateRef &state,
const Expr *Ex,
SVal Buf,
bool hypothetical = false) const;
const StringLiteral *getCStringLiteral(CheckerContext &C,
ProgramStateRef &state,
const Expr *expr,
SVal val) const;
static ProgramStateRef InvalidateBuffer(CheckerContext &C,
ProgramStateRef state,
const Expr *Ex, SVal V);
static bool SummarizeRegion(raw_ostream &os, ASTContext &Ctx,
const MemRegion *MR);
ProgramStateRef checkNonNull(CheckerContext &C,
ProgramStateRef state,
const Expr *S,
SVal l) const;
ProgramStateRef CheckLocation(CheckerContext &C,
ProgramStateRef state,
const Expr *S,
SVal l,
const char *message = NULL) const;
ProgramStateRef CheckBufferAccess(CheckerContext &C,
ProgramStateRef state,
const Expr *Size,
const Expr *FirstBuf,
const Expr *SecondBuf,
const char *firstMessage = NULL,
const char *secondMessage = NULL,
bool WarnAboutSize = false) const;
ProgramStateRef CheckBufferAccess(CheckerContext &C,
ProgramStateRef state,
const Expr *Size,
const Expr *Buf,
const char *message = NULL,
bool WarnAboutSize = false) const {
return CheckBufferAccess(C, state, Size, Buf, NULL, message, NULL,
WarnAboutSize);
}
ProgramStateRef CheckOverlap(CheckerContext &C,
ProgramStateRef state,
const Expr *Size,
const Expr *First,
const Expr *Second) const;
void emitOverlapBug(CheckerContext &C,
ProgramStateRef state,
const Stmt *First,
const Stmt *Second) const;
ProgramStateRef checkAdditionOverflow(CheckerContext &C,
ProgramStateRef state,
NonLoc left,
NonLoc right) const;
};
class CStringLength {
public:
typedef llvm::ImmutableMap<const MemRegion *, SVal> EntryMap;
};
}
namespace clang {
namespace ento {
template <>
struct ProgramStateTrait<CStringLength>
: public ProgramStatePartialTrait<CStringLength::EntryMap> {
static void *GDMIndex() { return CStringChecker::getTag(); }
};
}
}
std::pair<ProgramStateRef , ProgramStateRef >
CStringChecker::assumeZero(CheckerContext &C, ProgramStateRef state, SVal V,
QualType Ty) {
DefinedSVal *val = dyn_cast<DefinedSVal>(&V);
if (!val)
return std::pair<ProgramStateRef , ProgramStateRef >(state, state);
SValBuilder &svalBuilder = C.getSValBuilder();
DefinedOrUnknownSVal zero = svalBuilder.makeZeroVal(Ty);
return state->assume(svalBuilder.evalEQ(state, *val, zero));
}
ProgramStateRef CStringChecker::checkNonNull(CheckerContext &C,
ProgramStateRef state,
const Expr *S, SVal l) const {
if (!state)
return NULL;
ProgramStateRef stateNull, stateNonNull;
llvm::tie(stateNull, stateNonNull) = assumeZero(C, state, l, S->getType());
if (stateNull && !stateNonNull) {
if (!Filter.CheckCStringNullArg)
return NULL;
ExplodedNode *N = C.generateSink(stateNull);
if (!N)
return NULL;
if (!BT_Null)
BT_Null.reset(new BuiltinBug("Unix API",
"Null pointer argument in call to byte string function"));
SmallString<80> buf;
llvm::raw_svector_ostream os(buf);
assert(CurrentFunctionDescription);
os << "Null pointer argument in call to " << CurrentFunctionDescription;
BuiltinBug *BT = static_cast<BuiltinBug*>(BT_Null.get());
BugReport *report = new BugReport(*BT, os.str(), N);
report->addRange(S->getSourceRange());
bugreporter::trackNullOrUndefValue(N, S, *report);
C.EmitReport(report);
return NULL;
}
assert(stateNonNull);
return stateNonNull;
}
ProgramStateRef CStringChecker::CheckLocation(CheckerContext &C,
ProgramStateRef state,
const Expr *S, SVal l,
const char *warningMsg) const {
if (!state)
return NULL;
const MemRegion *R = l.getAsRegion();
if (!R)
return state;
const ElementRegion *ER = dyn_cast<ElementRegion>(R);
if (!ER)
return state;
assert(ER->getValueType() == C.getASTContext().CharTy &&
"CheckLocation should only be called with char* ElementRegions");
const SubRegion *superReg = cast<SubRegion>(ER->getSuperRegion());
SValBuilder &svalBuilder = C.getSValBuilder();
SVal Extent =
svalBuilder.convertToArrayIndex(superReg->getExtent(svalBuilder));
DefinedOrUnknownSVal Size = cast<DefinedOrUnknownSVal>(Extent);
DefinedOrUnknownSVal Idx = cast<DefinedOrUnknownSVal>(ER->getIndex());
ProgramStateRef StInBound = state->assumeInBound(Idx, Size, true);
ProgramStateRef StOutBound = state->assumeInBound(Idx, Size, false);
if (StOutBound && !StInBound) {
ExplodedNode *N = C.generateSink(StOutBound);
if (!N)
return NULL;
if (!BT_Bounds) {
BT_Bounds.reset(new BuiltinBug("Out-of-bound array access",
"Byte string function accesses out-of-bound array element"));
}
BuiltinBug *BT = static_cast<BuiltinBug*>(BT_Bounds.get());
BugReport *report;
if (warningMsg) {
report = new BugReport(*BT, warningMsg, N);
} else {
assert(CurrentFunctionDescription);
assert(CurrentFunctionDescription[0] != '\0');
SmallString<80> buf;
llvm::raw_svector_ostream os(buf);
os << (char)toupper(CurrentFunctionDescription[0])
<< &CurrentFunctionDescription[1]
<< " accesses out-of-bound array element";
report = new BugReport(*BT, os.str(), N);
}
report->addRange(S->getSourceRange());
C.EmitReport(report);
return NULL;
}
return StInBound;
}
ProgramStateRef CStringChecker::CheckBufferAccess(CheckerContext &C,
ProgramStateRef state,
const Expr *Size,
const Expr *FirstBuf,
const Expr *SecondBuf,
const char *firstMessage,
const char *secondMessage,
bool WarnAboutSize) const {
if (!state)
return NULL;
SValBuilder &svalBuilder = C.getSValBuilder();
ASTContext &Ctx = svalBuilder.getContext();
const LocationContext *LCtx = C.getLocationContext();
QualType sizeTy = Size->getType();
QualType PtrTy = Ctx.getPointerType(Ctx.CharTy);
SVal BufVal = state->getSVal(FirstBuf, LCtx);
state = checkNonNull(C, state, FirstBuf, BufVal);
if (!state)
return NULL;
if (!Filter.CheckCStringOutOfBounds)
return state;
SVal LengthVal = state->getSVal(Size, LCtx);
NonLoc *Length = dyn_cast<NonLoc>(&LengthVal);
if (!Length)
return state;
NonLoc One = cast<NonLoc>(svalBuilder.makeIntVal(1, sizeTy));
NonLoc LastOffset = cast<NonLoc>(svalBuilder.evalBinOpNN(state, BO_Sub,
*Length, One, sizeTy));
SVal BufStart = svalBuilder.evalCast(BufVal, PtrTy, FirstBuf->getType());
if (Loc *BufLoc = dyn_cast<Loc>(&BufStart)) {
const Expr *warningExpr = (WarnAboutSize ? Size : FirstBuf);
SVal BufEnd = svalBuilder.evalBinOpLN(state, BO_Add, *BufLoc,
LastOffset, PtrTy);
state = CheckLocation(C, state, warningExpr, BufEnd, firstMessage);
if (!state)
return NULL;
}
if (SecondBuf) {
BufVal = state->getSVal(SecondBuf, LCtx);
state = checkNonNull(C, state, SecondBuf, BufVal);
if (!state)
return NULL;
BufStart = svalBuilder.evalCast(BufVal, PtrTy, SecondBuf->getType());
if (Loc *BufLoc = dyn_cast<Loc>(&BufStart)) {
const Expr *warningExpr = (WarnAboutSize ? Size : SecondBuf);
SVal BufEnd = svalBuilder.evalBinOpLN(state, BO_Add, *BufLoc,
LastOffset, PtrTy);
state = CheckLocation(C, state, warningExpr, BufEnd, secondMessage);
}
}
return state;
}
ProgramStateRef CStringChecker::CheckOverlap(CheckerContext &C,
ProgramStateRef state,
const Expr *Size,
const Expr *First,
const Expr *Second) const {
if (!Filter.CheckCStringBufferOverlap)
return state;
if (!state)
return NULL;
ProgramStateRef stateTrue, stateFalse;
const LocationContext *LCtx = C.getLocationContext();
SVal firstVal = state->getSVal(First, LCtx);
SVal secondVal = state->getSVal(Second, LCtx);
Loc *firstLoc = dyn_cast<Loc>(&firstVal);
if (!firstLoc)
return state;
Loc *secondLoc = dyn_cast<Loc>(&secondVal);
if (!secondLoc)
return state;
SValBuilder &svalBuilder = C.getSValBuilder();
llvm::tie(stateTrue, stateFalse) =
state->assume(svalBuilder.evalEQ(state, *firstLoc, *secondLoc));
if (stateTrue && !stateFalse) {
emitOverlapBug(C, stateTrue, First, Second);
return NULL;
}
assert(stateFalse);
state = stateFalse;
QualType cmpTy = svalBuilder.getConditionType();
SVal reverse = svalBuilder.evalBinOpLL(state, BO_GT,
*firstLoc, *secondLoc, cmpTy);
DefinedOrUnknownSVal *reverseTest = dyn_cast<DefinedOrUnknownSVal>(&reverse);
if (!reverseTest)
return state;
llvm::tie(stateTrue, stateFalse) = state->assume(*reverseTest);
if (stateTrue) {
if (stateFalse) {
return state;
} else {
Loc *tmpLoc = firstLoc;
firstLoc = secondLoc;
secondLoc = tmpLoc;
const Expr *tmpExpr = First;
First = Second;
Second = tmpExpr;
}
}
SVal LengthVal = state->getSVal(Size, LCtx);
NonLoc *Length = dyn_cast<NonLoc>(&LengthVal);
if (!Length)
return state;
ASTContext &Ctx = svalBuilder.getContext();
QualType CharPtrTy = Ctx.getPointerType(Ctx.CharTy);
SVal FirstStart = svalBuilder.evalCast(*firstLoc, CharPtrTy,
First->getType());
Loc *FirstStartLoc = dyn_cast<Loc>(&FirstStart);
if (!FirstStartLoc)
return state;
SVal FirstEnd = svalBuilder.evalBinOpLN(state, BO_Add,
*FirstStartLoc, *Length, CharPtrTy);
Loc *FirstEndLoc = dyn_cast<Loc>(&FirstEnd);
if (!FirstEndLoc)
return state;
SVal Overlap = svalBuilder.evalBinOpLL(state, BO_GT,
*FirstEndLoc, *secondLoc, cmpTy);
DefinedOrUnknownSVal *OverlapTest = dyn_cast<DefinedOrUnknownSVal>(&Overlap);
if (!OverlapTest)
return state;
llvm::tie(stateTrue, stateFalse) = state->assume(*OverlapTest);
if (stateTrue && !stateFalse) {
emitOverlapBug(C, stateTrue, First, Second);
return NULL;
}
assert(stateFalse);
return stateFalse;
}
void CStringChecker::emitOverlapBug(CheckerContext &C, ProgramStateRef state,
const Stmt *First, const Stmt *Second) const {
ExplodedNode *N = C.generateSink(state);
if (!N)
return;
if (!BT_Overlap)
BT_Overlap.reset(new BugType("Unix API", "Improper arguments"));
BugReport *report =
new BugReport(*BT_Overlap,
"Arguments must not be overlapping buffers", N);
report->addRange(First->getSourceRange());
report->addRange(Second->getSourceRange());
C.EmitReport(report);
}
ProgramStateRef CStringChecker::checkAdditionOverflow(CheckerContext &C,
ProgramStateRef state,
NonLoc left,
NonLoc right) const {
if (!Filter.CheckCStringOutOfBounds)
return state;
if (!state)
return NULL;
SValBuilder &svalBuilder = C.getSValBuilder();
BasicValueFactory &BVF = svalBuilder.getBasicValueFactory();
QualType sizeTy = svalBuilder.getContext().getSizeType();
const llvm::APSInt &maxValInt = BVF.getMaxValue(sizeTy);
NonLoc maxVal = svalBuilder.makeIntVal(maxValInt);
SVal maxMinusRight;
if (isa<nonloc::ConcreteInt>(right)) {
maxMinusRight = svalBuilder.evalBinOpNN(state, BO_Sub, maxVal, right,
sizeTy);
} else {
maxMinusRight = svalBuilder.evalBinOpNN(state, BO_Sub, maxVal, left,
sizeTy);
left = right;
}
if (NonLoc *maxMinusRightNL = dyn_cast<NonLoc>(&maxMinusRight)) {
QualType cmpTy = svalBuilder.getConditionType();
SVal willOverflow = svalBuilder.evalBinOpNN(state, BO_GT, left,
*maxMinusRightNL, cmpTy);
ProgramStateRef stateOverflow, stateOkay;
llvm::tie(stateOverflow, stateOkay) =
state->assume(cast<DefinedOrUnknownSVal>(willOverflow));
if (stateOverflow && !stateOkay) {
ExplodedNode *N = C.generateSink(stateOverflow);
if (!N)
return NULL;
if (!BT_AdditionOverflow)
BT_AdditionOverflow.reset(new BuiltinBug("API",
"Sum of expressions causes overflow"));
const char *warning =
"This expression will create a string whose length is too big to "
"be represented as a size_t";
BugReport *report = new BugReport(*BT_AdditionOverflow, warning, N);
C.EmitReport(report);
return NULL;
}
assert(stateOkay);
state = stateOkay;
}
return state;
}
ProgramStateRef CStringChecker::setCStringLength(ProgramStateRef state,
const MemRegion *MR,
SVal strLength) {
assert(!strLength.isUndef() && "Attempt to set an undefined string length");
MR = MR->StripCasts();
switch (MR->getKind()) {
case MemRegion::StringRegionKind:
return state;
case MemRegion::SymbolicRegionKind:
case MemRegion::AllocaRegionKind:
case MemRegion::VarRegionKind:
case MemRegion::FieldRegionKind:
case MemRegion::ObjCIvarRegionKind:
break;
case MemRegion::ElementRegionKind:
return state;
default:
return state;
}
if (strLength.isUnknown())
return state->remove<CStringLength>(MR);
return state->set<CStringLength>(MR, strLength);
}
SVal CStringChecker::getCStringLengthForRegion(CheckerContext &C,
ProgramStateRef &state,
const Expr *Ex,
const MemRegion *MR,
bool hypothetical) {
if (!hypothetical) {
const SVal *Recorded = state->get<CStringLength>(MR);
if (Recorded)
return *Recorded;
}
SValBuilder &svalBuilder = C.getSValBuilder();
QualType sizeTy = svalBuilder.getContext().getSizeType();
SVal strLength = svalBuilder.getMetadataSymbolVal(CStringChecker::getTag(),
MR, Ex, sizeTy,
C.blockCount());
if (!hypothetical)
state = state->set<CStringLength>(MR, strLength);
return strLength;
}
SVal CStringChecker::getCStringLength(CheckerContext &C, ProgramStateRef &state,
const Expr *Ex, SVal Buf,
bool hypothetical) const {
const MemRegion *MR = Buf.getAsRegion();
if (!MR) {
if (loc::GotoLabel *Label = dyn_cast<loc::GotoLabel>(&Buf)) {
if (!Filter.CheckCStringNotNullTerm)
return UndefinedVal();
if (ExplodedNode *N = C.addTransition(state)) {
if (!BT_NotCString)
BT_NotCString.reset(new BuiltinBug("Unix API",
"Argument is not a null-terminated string."));
SmallString<120> buf;
llvm::raw_svector_ostream os(buf);
assert(CurrentFunctionDescription);
os << "Argument to " << CurrentFunctionDescription
<< " is the address of the label '" << Label->getLabel()->getName()
<< "', which is not a null-terminated string";
BugReport *report = new BugReport(*BT_NotCString,
os.str(), N);
report->addRange(Ex->getSourceRange());
C.EmitReport(report);
}
return UndefinedVal();
}
return UnknownVal();
}
MR = MR->StripCasts();
switch (MR->getKind()) {
case MemRegion::StringRegionKind: {
SValBuilder &svalBuilder = C.getSValBuilder();
QualType sizeTy = svalBuilder.getContext().getSizeType();
const StringLiteral *strLit = cast<StringRegion>(MR)->getStringLiteral();
return svalBuilder.makeIntVal(strLit->getByteLength(), sizeTy);
}
case MemRegion::SymbolicRegionKind:
case MemRegion::AllocaRegionKind:
case MemRegion::VarRegionKind:
case MemRegion::FieldRegionKind:
case MemRegion::ObjCIvarRegionKind:
return getCStringLengthForRegion(C, state, Ex, MR, hypothetical);
case MemRegion::CompoundLiteralRegionKind:
return UnknownVal();
case MemRegion::ElementRegionKind:
return UnknownVal();
default:
if (!Filter.CheckCStringNotNullTerm)
return UndefinedVal();
if (ExplodedNode *N = C.addTransition(state)) {
if (!BT_NotCString)
BT_NotCString.reset(new BuiltinBug("Unix API",
"Argument is not a null-terminated string."));
SmallString<120> buf;
llvm::raw_svector_ostream os(buf);
assert(CurrentFunctionDescription);
os << "Argument to " << CurrentFunctionDescription << " is ";
if (SummarizeRegion(os, C.getASTContext(), MR))
os << ", which is not a null-terminated string";
else
os << "not a null-terminated string";
BugReport *report = new BugReport(*BT_NotCString,
os.str(), N);
report->addRange(Ex->getSourceRange());
C.EmitReport(report);
}
return UndefinedVal();
}
}
const StringLiteral *CStringChecker::getCStringLiteral(CheckerContext &C,
ProgramStateRef &state, const Expr *expr, SVal val) const {
const MemRegion *bufRegion = val.getAsRegion();
if (!bufRegion)
return NULL;
bufRegion = bufRegion->StripCasts();
const StringRegion *strRegion= dyn_cast<StringRegion>(bufRegion);
if (!strRegion)
return NULL;
return strRegion->getStringLiteral();
}
ProgramStateRef CStringChecker::InvalidateBuffer(CheckerContext &C,
ProgramStateRef state,
const Expr *E, SVal V) {
Loc *L = dyn_cast<Loc>(&V);
if (!L)
return state;
if (loc::MemRegionVal* MR = dyn_cast<loc::MemRegionVal>(L)) {
const MemRegion *R = MR->getRegion()->StripCasts();
if (const ElementRegion *ER = dyn_cast<ElementRegion>(R)) {
R = ER->getSuperRegion();
}
const LocationContext *LCtx = C.getPredecessor()->getLocationContext();
return state->invalidateRegions(R, E, C.blockCount(), LCtx);
}
return state->killBinding(*L);
}
bool CStringChecker::SummarizeRegion(raw_ostream &os, ASTContext &Ctx,
const MemRegion *MR) {
const TypedValueRegion *TVR = dyn_cast<TypedValueRegion>(MR);
switch (MR->getKind()) {
case MemRegion::FunctionTextRegionKind: {
const NamedDecl *FD = cast<FunctionTextRegion>(MR)->getDecl();
if (FD)
os << "the address of the function '" << *FD << '\'';
else
os << "the address of a function";
return true;
}
case MemRegion::BlockTextRegionKind:
os << "block text";
return true;
case MemRegion::BlockDataRegionKind:
os << "a block";
return true;
case MemRegion::CXXThisRegionKind:
case MemRegion::CXXTempObjectRegionKind:
os << "a C++ temp object of type " << TVR->getValueType().getAsString();
return true;
case MemRegion::VarRegionKind:
os << "a variable of type" << TVR->getValueType().getAsString();
return true;
case MemRegion::FieldRegionKind:
os << "a field of type " << TVR->getValueType().getAsString();
return true;
case MemRegion::ObjCIvarRegionKind:
os << "an instance variable of type " << TVR->getValueType().getAsString();
return true;
default:
return false;
}
}
void CStringChecker::evalCopyCommon(CheckerContext &C,
const CallExpr *CE,
ProgramStateRef state,
const Expr *Size, const Expr *Dest,
const Expr *Source, bool Restricted,
bool IsMempcpy) const {
CurrentFunctionDescription = "memory copy function";
const LocationContext *LCtx = C.getLocationContext();
SVal sizeVal = state->getSVal(Size, LCtx);
QualType sizeTy = Size->getType();
ProgramStateRef stateZeroSize, stateNonZeroSize;
llvm::tie(stateZeroSize, stateNonZeroSize) =
assumeZero(C, state, sizeVal, sizeTy);
SVal destVal = state->getSVal(Dest, LCtx);
if (stateZeroSize && !stateNonZeroSize) {
stateZeroSize = stateZeroSize->BindExpr(CE, LCtx, destVal);
C.addTransition(stateZeroSize);
return;
}
if (stateNonZeroSize) {
state = stateNonZeroSize;
state = checkNonNull(C, state, Dest, destVal);
if (!state)
return;
SVal srcVal = state->getSVal(Source, LCtx);
state = checkNonNull(C, state, Source, srcVal);
if (!state)
return;
const char * const writeWarning =
"Memory copy function overflows destination buffer";
state = CheckBufferAccess(C, state, Size, Dest, Source,
writeWarning, NULL);
if (Restricted)
state = CheckOverlap(C, state, Size, Dest, Source);
if (!state)
return;
if (IsMempcpy) {
loc::MemRegionVal *destRegVal = dyn_cast<loc::MemRegionVal>(&destVal);
assert(destRegVal && "Destination should be a known MemRegionVal here");
NonLoc *lenValNonLoc = dyn_cast<NonLoc>(&sizeVal);
if (lenValNonLoc) {
SVal lastElement = C.getSValBuilder().evalBinOpLN(state, BO_Add,
*destRegVal,
*lenValNonLoc,
Dest->getType());
state = state->BindExpr(CE, LCtx, lastElement);
} else {
SVal result = C.getSValBuilder().conjureSymbolVal(0, CE, LCtx,
C.blockCount());
state = state->BindExpr(CE, LCtx, result);
}
} else {
state = state->BindExpr(CE, LCtx, destVal);
}
state = InvalidateBuffer(C, state, Dest,
state->getSVal(Dest, C.getLocationContext()));
C.addTransition(state);
}
}
void CStringChecker::evalMemcpy(CheckerContext &C, const CallExpr *CE) const {
if (CE->getNumArgs() < 3)
return;
const Expr *Dest = CE->getArg(0);
ProgramStateRef state = C.getState();
evalCopyCommon(C, CE, state, CE->getArg(2), Dest, CE->getArg(1), true);
}
void CStringChecker::evalMempcpy(CheckerContext &C, const CallExpr *CE) const {
if (CE->getNumArgs() < 3)
return;
const Expr *Dest = CE->getArg(0);
ProgramStateRef state = C.getState();
evalCopyCommon(C, CE, state, CE->getArg(2), Dest, CE->getArg(1), true, true);
}
void CStringChecker::evalMemmove(CheckerContext &C, const CallExpr *CE) const {
if (CE->getNumArgs() < 3)
return;
const Expr *Dest = CE->getArg(0);
ProgramStateRef state = C.getState();
evalCopyCommon(C, CE, state, CE->getArg(2), Dest, CE->getArg(1));
}
void CStringChecker::evalBcopy(CheckerContext &C, const CallExpr *CE) const {
if (CE->getNumArgs() < 3)
return;
evalCopyCommon(C, CE, C.getState(),
CE->getArg(2), CE->getArg(1), CE->getArg(0));
}
void CStringChecker::evalMemcmp(CheckerContext &C, const CallExpr *CE) const {
if (CE->getNumArgs() < 3)
return;
CurrentFunctionDescription = "memory comparison function";
const Expr *Left = CE->getArg(0);
const Expr *Right = CE->getArg(1);
const Expr *Size = CE->getArg(2);
ProgramStateRef state = C.getState();
SValBuilder &svalBuilder = C.getSValBuilder();
const LocationContext *LCtx = C.getLocationContext();
SVal sizeVal = state->getSVal(Size, LCtx);
QualType sizeTy = Size->getType();
ProgramStateRef stateZeroSize, stateNonZeroSize;
llvm::tie(stateZeroSize, stateNonZeroSize) =
assumeZero(C, state, sizeVal, sizeTy);
if (stateZeroSize) {
state = stateZeroSize;
state = state->BindExpr(CE, LCtx,
svalBuilder.makeZeroVal(CE->getType()));
C.addTransition(state);
}
if (stateNonZeroSize) {
state = stateNonZeroSize;
DefinedOrUnknownSVal LV =
cast<DefinedOrUnknownSVal>(state->getSVal(Left, LCtx));
DefinedOrUnknownSVal RV =
cast<DefinedOrUnknownSVal>(state->getSVal(Right, LCtx));
DefinedOrUnknownSVal SameBuf = svalBuilder.evalEQ(state, LV, RV);
ProgramStateRef StSameBuf, StNotSameBuf;
llvm::tie(StSameBuf, StNotSameBuf) = state->assume(SameBuf);
if (StSameBuf) {
state = StSameBuf;
state = CheckBufferAccess(C, state, Size, Left);
if (state) {
state = StSameBuf->BindExpr(CE, LCtx,
svalBuilder.makeZeroVal(CE->getType()));
C.addTransition(state);
}
}
if (StNotSameBuf) {
state = StNotSameBuf;
state = CheckBufferAccess(C, state, Size, Left, Right);
if (state) {
SVal CmpV = svalBuilder.conjureSymbolVal(0, CE, LCtx, C.blockCount());
state = state->BindExpr(CE, LCtx, CmpV);
C.addTransition(state);
}
}
}
}
void CStringChecker::evalstrLength(CheckerContext &C,
const CallExpr *CE) const {
if (CE->getNumArgs() < 1)
return;
evalstrLengthCommon(C, CE, false);
}
void CStringChecker::evalstrnLength(CheckerContext &C,
const CallExpr *CE) const {
if (CE->getNumArgs() < 2)
return;
evalstrLengthCommon(C, CE, true);
}
void CStringChecker::evalstrLengthCommon(CheckerContext &C, const CallExpr *CE,
bool IsStrnlen) const {
CurrentFunctionDescription = "string length function";
ProgramStateRef state = C.getState();
const LocationContext *LCtx = C.getLocationContext();
if (IsStrnlen) {
const Expr *maxlenExpr = CE->getArg(1);
SVal maxlenVal = state->getSVal(maxlenExpr, LCtx);
ProgramStateRef stateZeroSize, stateNonZeroSize;
llvm::tie(stateZeroSize, stateNonZeroSize) =
assumeZero(C, state, maxlenVal, maxlenExpr->getType());
if (stateZeroSize) {
SVal zero = C.getSValBuilder().makeZeroVal(CE->getType());
stateZeroSize = stateZeroSize->BindExpr(CE, LCtx, zero);
C.addTransition(stateZeroSize);
}
if (!stateNonZeroSize)
return;
state = stateNonZeroSize;
}
const Expr *Arg = CE->getArg(0);
SVal ArgVal = state->getSVal(Arg, LCtx);
state = checkNonNull(C, state, Arg, ArgVal);
if (!state)
return;
SVal strLength = getCStringLength(C, state, Arg, ArgVal);
if (strLength.isUndef())
return;
DefinedOrUnknownSVal result = UnknownVal();
if (IsStrnlen) {
QualType cmpTy = C.getSValBuilder().getConditionType();
const Expr *maxlenExpr = CE->getArg(1);
SVal maxlenVal = state->getSVal(maxlenExpr, LCtx);
NonLoc *strLengthNL = dyn_cast<NonLoc>(&strLength);
NonLoc *maxlenValNL = dyn_cast<NonLoc>(&maxlenVal);
if (strLengthNL && maxlenValNL) {
ProgramStateRef stateStringTooLong, stateStringNotTooLong;
llvm::tie(stateStringTooLong, stateStringNotTooLong) =
state->assume(cast<DefinedOrUnknownSVal>
(C.getSValBuilder().evalBinOpNN(state, BO_GT,
*strLengthNL,
*maxlenValNL,
cmpTy)));
if (stateStringTooLong && !stateStringNotTooLong) {
result = *maxlenValNL;
} else if (stateStringNotTooLong && !stateStringTooLong) {
result = *strLengthNL;
}
}
if (result.isUnknown()) {
result = C.getSValBuilder().conjureSymbolVal(0, CE, LCtx, C.blockCount());
NonLoc *resultNL = cast<NonLoc>(&result);
if (strLengthNL) {
state = state->assume(cast<DefinedOrUnknownSVal>
(C.getSValBuilder().evalBinOpNN(state, BO_LE,
*resultNL,
*strLengthNL,
cmpTy)), true);
}
if (maxlenValNL) {
state = state->assume(cast<DefinedOrUnknownSVal>
(C.getSValBuilder().evalBinOpNN(state, BO_LE,
*resultNL,
*maxlenValNL,
cmpTy)), true);
}
}
} else {
result = cast<DefinedOrUnknownSVal>(strLength);
if (result.isUnknown()) {
result = C.getSValBuilder().conjureSymbolVal(0, CE, LCtx, C.blockCount());
}
}
assert(!result.isUnknown() && "Should have conjured a value by now");
state = state->BindExpr(CE, LCtx, result);
C.addTransition(state);
}
void CStringChecker::evalStrcpy(CheckerContext &C, const CallExpr *CE) const {
if (CE->getNumArgs() < 2)
return;
evalStrcpyCommon(C, CE,
false,
false,
false);
}
void CStringChecker::evalStrncpy(CheckerContext &C, const CallExpr *CE) const {
if (CE->getNumArgs() < 3)
return;
evalStrcpyCommon(C, CE,
false,
true,
false);
}
void CStringChecker::evalStpcpy(CheckerContext &C, const CallExpr *CE) const {
if (CE->getNumArgs() < 2)
return;
evalStrcpyCommon(C, CE,
true,
false,
false);
}
void CStringChecker::evalStrcat(CheckerContext &C, const CallExpr *CE) const {
if (CE->getNumArgs() < 2)
return;
evalStrcpyCommon(C, CE,
false,
false,
true);
}
void CStringChecker::evalStrncat(CheckerContext &C, const CallExpr *CE) const {
if (CE->getNumArgs() < 3)
return;
evalStrcpyCommon(C, CE,
false,
true,
true);
}
void CStringChecker::evalStrcpyCommon(CheckerContext &C, const CallExpr *CE,
bool returnEnd, bool isBounded,
bool isAppending) const {
CurrentFunctionDescription = "string copy function";
ProgramStateRef state = C.getState();
const LocationContext *LCtx = C.getLocationContext();
const Expr *Dst = CE->getArg(0);
SVal DstVal = state->getSVal(Dst, LCtx);
state = checkNonNull(C, state, Dst, DstVal);
if (!state)
return;
const Expr *srcExpr = CE->getArg(1);
SVal srcVal = state->getSVal(srcExpr, LCtx);
state = checkNonNull(C, state, srcExpr, srcVal);
if (!state)
return;
SVal strLength = getCStringLength(C, state, srcExpr, srcVal);
if (strLength.isUndef())
return;
SValBuilder &svalBuilder = C.getSValBuilder();
QualType cmpTy = svalBuilder.getConditionType();
QualType sizeTy = svalBuilder.getContext().getSizeType();
SVal amountCopied = UnknownVal();
SVal maxLastElementIndex = UnknownVal();
const char *boundWarning = NULL;
if (isBounded) {
const Expr *lenExpr = CE->getArg(2);
SVal lenVal = state->getSVal(lenExpr, LCtx);
lenVal = svalBuilder.evalCast(lenVal, sizeTy, lenExpr->getType());
NonLoc *strLengthNL = dyn_cast<NonLoc>(&strLength);
NonLoc *lenValNL = dyn_cast<NonLoc>(&lenVal);
if (strLengthNL && lenValNL) {
ProgramStateRef stateSourceTooLong, stateSourceNotTooLong;
llvm::tie(stateSourceTooLong, stateSourceNotTooLong) =
state->assume(cast<DefinedOrUnknownSVal>
(svalBuilder.evalBinOpNN(state, BO_GE, *strLengthNL,
*lenValNL, cmpTy)));
if (stateSourceTooLong && !stateSourceNotTooLong) {
state = stateSourceTooLong;
amountCopied = lenVal;
} else if (!stateSourceTooLong && stateSourceNotTooLong) {
state = stateSourceNotTooLong;
amountCopied = strLength;
}
}
if (lenValNL) {
if (isAppending) {
SVal dstStrLength = getCStringLength(C, state, Dst, DstVal);
if (dstStrLength.isUndef())
return;
if (NonLoc *dstStrLengthNL = dyn_cast<NonLoc>(&dstStrLength)) {
maxLastElementIndex = svalBuilder.evalBinOpNN(state, BO_Add,
*lenValNL,
*dstStrLengthNL,
sizeTy);
boundWarning = "Size argument is greater than the free space in the "
"destination buffer";
}
} else {
ProgramStateRef StateZeroSize, StateNonZeroSize;
llvm::tie(StateZeroSize, StateNonZeroSize) =
assumeZero(C, state, *lenValNL, sizeTy);
if (StateZeroSize && !StateNonZeroSize) {
StateZeroSize = StateZeroSize->BindExpr(CE, LCtx, DstVal);
C.addTransition(StateZeroSize);
return;
}
NonLoc one = cast<NonLoc>(svalBuilder.makeIntVal(1, sizeTy));
maxLastElementIndex = svalBuilder.evalBinOpNN(state, BO_Sub, *lenValNL,
one, sizeTy);
boundWarning = "Size argument is greater than the length of the "
"destination buffer";
}
}
if (amountCopied.isUnknown() && !isAppending) {
amountCopied = getCStringLength(C, state, lenExpr, srcVal, true);
assert(!amountCopied.isUndef());
if (NonLoc *amountCopiedNL = dyn_cast<NonLoc>(&amountCopied)) {
if (lenValNL) {
SVal copiedLessThanBound = svalBuilder.evalBinOpNN(state, BO_LE,
*amountCopiedNL,
*lenValNL,
cmpTy);
state = state->assume(cast<DefinedOrUnknownSVal>(copiedLessThanBound),
true);
if (!state)
return;
}
if (strLengthNL) {
SVal copiedLessThanSrc = svalBuilder.evalBinOpNN(state, BO_LE,
*amountCopiedNL,
*strLengthNL,
cmpTy);
state = state->assume(cast<DefinedOrUnknownSVal>(copiedLessThanSrc),
true);
if (!state)
return;
}
}
}
} else {
amountCopied = strLength;
}
assert(state);
SVal finalStrLength = UnknownVal();
if (isAppending) {
SVal dstStrLength = getCStringLength(C, state, Dst, DstVal);
if (dstStrLength.isUndef())
return;
NonLoc *srcStrLengthNL = dyn_cast<NonLoc>(&amountCopied);
NonLoc *dstStrLengthNL = dyn_cast<NonLoc>(&dstStrLength);
if (srcStrLengthNL && dstStrLengthNL) {
state = checkAdditionOverflow(C, state, *srcStrLengthNL, *dstStrLengthNL);
if (!state)
return;
finalStrLength = svalBuilder.evalBinOpNN(state, BO_Add, *srcStrLengthNL,
*dstStrLengthNL, sizeTy);
}
if (finalStrLength.isUnknown()) {
finalStrLength = getCStringLength(C, state, CE, DstVal, true);
assert(!finalStrLength.isUndef());
if (NonLoc *finalStrLengthNL = dyn_cast<NonLoc>(&finalStrLength)) {
if (srcStrLengthNL) {
SVal sourceInResult = svalBuilder.evalBinOpNN(state, BO_GE,
*finalStrLengthNL,
*srcStrLengthNL,
cmpTy);
state = state->assume(cast<DefinedOrUnknownSVal>(sourceInResult),
true);
if (!state)
return;
}
if (dstStrLengthNL) {
SVal destInResult = svalBuilder.evalBinOpNN(state, BO_GE,
*finalStrLengthNL,
*dstStrLengthNL,
cmpTy);
state = state->assume(cast<DefinedOrUnknownSVal>(destInResult),
true);
if (!state)
return;
}
}
}
} else {
finalStrLength = amountCopied;
}
SVal Result = (returnEnd ? UnknownVal() : DstVal);
assert(state);
if (loc::MemRegionVal *dstRegVal = dyn_cast<loc::MemRegionVal>(&DstVal)) {
QualType ptrTy = Dst->getType();
if (boundWarning) {
if (NonLoc *maxLastNL = dyn_cast<NonLoc>(&maxLastElementIndex)) {
SVal maxLastElement = svalBuilder.evalBinOpLN(state, BO_Add, *dstRegVal,
*maxLastNL, ptrTy);
state = CheckLocation(C, state, CE->getArg(2), maxLastElement,
boundWarning);
if (!state)
return;
}
}
if (NonLoc *knownStrLength = dyn_cast<NonLoc>(&finalStrLength)) {
SVal lastElement = svalBuilder.evalBinOpLN(state, BO_Add, *dstRegVal,
*knownStrLength, ptrTy);
if (!boundWarning) {
const char * const warningMsg =
"String copy function overflows destination buffer";
state = CheckLocation(C, state, Dst, lastElement, warningMsg);
if (!state)
return;
}
if (returnEnd)
Result = lastElement;
}
state = InvalidateBuffer(C, state, Dst, *dstRegVal);
if (isBounded && !isAppending) {
if (amountCopied != strLength)
finalStrLength = UnknownVal();
}
state = setCStringLength(state, dstRegVal->getRegion(), finalStrLength);
}
assert(state);
if (returnEnd && Result.isUnknown()) {
Result = svalBuilder.conjureSymbolVal(0, CE, LCtx, C.blockCount());
}
state = state->BindExpr(CE, LCtx, Result);
C.addTransition(state);
}
void CStringChecker::evalStrcmp(CheckerContext &C, const CallExpr *CE) const {
if (CE->getNumArgs() < 2)
return;
evalStrcmpCommon(C, CE, false, false);
}
void CStringChecker::evalStrncmp(CheckerContext &C, const CallExpr *CE) const {
if (CE->getNumArgs() < 3)
return;
evalStrcmpCommon(C, CE, true, false);
}
void CStringChecker::evalStrcasecmp(CheckerContext &C,
const CallExpr *CE) const {
if (CE->getNumArgs() < 2)
return;
evalStrcmpCommon(C, CE, false, true);
}
void CStringChecker::evalStrncasecmp(CheckerContext &C,
const CallExpr *CE) const {
if (CE->getNumArgs() < 3)
return;
evalStrcmpCommon(C, CE, true, true);
}
void CStringChecker::evalStrcmpCommon(CheckerContext &C, const CallExpr *CE,
bool isBounded, bool ignoreCase) const {
CurrentFunctionDescription = "string comparison function";
ProgramStateRef state = C.getState();
const LocationContext *LCtx = C.getLocationContext();
const Expr *s1 = CE->getArg(0);
SVal s1Val = state->getSVal(s1, LCtx);
state = checkNonNull(C, state, s1, s1Val);
if (!state)
return;
const Expr *s2 = CE->getArg(1);
SVal s2Val = state->getSVal(s2, LCtx);
state = checkNonNull(C, state, s2, s2Val);
if (!state)
return;
SVal s1Length = getCStringLength(C, state, s1, s1Val);
if (s1Length.isUndef())
return;
SVal s2Length = getCStringLength(C, state, s2, s2Val);
if (s2Length.isUndef())
return;
DefinedOrUnknownSVal LV = cast<DefinedOrUnknownSVal>(s1Val);
DefinedOrUnknownSVal RV = cast<DefinedOrUnknownSVal>(s2Val);
SValBuilder &svalBuilder = C.getSValBuilder();
DefinedOrUnknownSVal SameBuf = svalBuilder.evalEQ(state, LV, RV);
ProgramStateRef StSameBuf, StNotSameBuf;
llvm::tie(StSameBuf, StNotSameBuf) = state->assume(SameBuf);
if (StSameBuf) {
StSameBuf = StSameBuf->BindExpr(CE, LCtx,
svalBuilder.makeZeroVal(CE->getType()));
C.addTransition(StSameBuf);
if (!StNotSameBuf)
return;
}
assert(StNotSameBuf);
state = StNotSameBuf;
const StringLiteral *s1StrLiteral = getCStringLiteral(C, state, s1, s1Val);
const StringLiteral *s2StrLiteral = getCStringLiteral(C, state, s2, s2Val);
bool canComputeResult = false;
if (s1StrLiteral && s2StrLiteral) {
StringRef s1StrRef = s1StrLiteral->getString();
StringRef s2StrRef = s2StrLiteral->getString();
if (isBounded) {
const Expr *lenExpr = CE->getArg(2);
SVal lenVal = state->getSVal(lenExpr, LCtx);
if (const llvm::APSInt *len = svalBuilder.getKnownValue(state, lenVal)) {
s1StrRef = s1StrRef.substr(0, (size_t)len->getZExtValue());
s2StrRef = s2StrRef.substr(0, (size_t)len->getZExtValue());
canComputeResult = true;
}
} else {
canComputeResult = true;
}
if (canComputeResult) {
size_t s1Term = s1StrRef.find('\0');
if (s1Term != StringRef::npos)
s1StrRef = s1StrRef.substr(0, s1Term);
size_t s2Term = s2StrRef.find('\0');
if (s2Term != StringRef::npos)
s2StrRef = s2StrRef.substr(0, s2Term);
int result;
if (ignoreCase) {
result = s1StrRef.compare_lower(s2StrRef);
} else {
result = s1StrRef.compare(s2StrRef);
}
SVal resultVal = svalBuilder.makeIntVal(result, CE->getType());
state = state->BindExpr(CE, LCtx, resultVal);
}
}
if (!canComputeResult) {
SVal resultVal = svalBuilder.conjureSymbolVal(0, CE, LCtx, C.blockCount());
state = state->BindExpr(CE, LCtx, resultVal);
}
C.addTransition(state);
}
bool CStringChecker::evalCall(const CallExpr *CE, CheckerContext &C) const {
const FunctionDecl *FDecl = C.getCalleeDecl(CE);
if (!FDecl)
return false;
FnCheck evalFunction = 0;
if (C.isCLibraryFunction(FDecl, "memcpy"))
evalFunction = &CStringChecker::evalMemcpy;
else if (C.isCLibraryFunction(FDecl, "mempcpy"))
evalFunction = &CStringChecker::evalMempcpy;
else if (C.isCLibraryFunction(FDecl, "memcmp"))
evalFunction = &CStringChecker::evalMemcmp;
else if (C.isCLibraryFunction(FDecl, "memmove"))
evalFunction = &CStringChecker::evalMemmove;
else if (C.isCLibraryFunction(FDecl, "strcpy"))
evalFunction = &CStringChecker::evalStrcpy;
else if (C.isCLibraryFunction(FDecl, "strncpy"))
evalFunction = &CStringChecker::evalStrncpy;
else if (C.isCLibraryFunction(FDecl, "stpcpy"))
evalFunction = &CStringChecker::evalStpcpy;
else if (C.isCLibraryFunction(FDecl, "strcat"))
evalFunction = &CStringChecker::evalStrcat;
else if (C.isCLibraryFunction(FDecl, "strncat"))
evalFunction = &CStringChecker::evalStrncat;
else if (C.isCLibraryFunction(FDecl, "strlen"))
evalFunction = &CStringChecker::evalstrLength;
else if (C.isCLibraryFunction(FDecl, "strnlen"))
evalFunction = &CStringChecker::evalstrnLength;
else if (C.isCLibraryFunction(FDecl, "strcmp"))
evalFunction = &CStringChecker::evalStrcmp;
else if (C.isCLibraryFunction(FDecl, "strncmp"))
evalFunction = &CStringChecker::evalStrncmp;
else if (C.isCLibraryFunction(FDecl, "strcasecmp"))
evalFunction = &CStringChecker::evalStrcasecmp;
else if (C.isCLibraryFunction(FDecl, "strncasecmp"))
evalFunction = &CStringChecker::evalStrncasecmp;
else if (C.isCLibraryFunction(FDecl, "bcopy"))
evalFunction = &CStringChecker::evalBcopy;
else if (C.isCLibraryFunction(FDecl, "bcmp"))
evalFunction = &CStringChecker::evalMemcmp;
if (!evalFunction)
return false;
assert(!(CurrentFunctionDescription = NULL));
(this->*evalFunction)(C, CE);
if (!C.isDifferent())
return false;
return true;
}
void CStringChecker::checkPreStmt(const DeclStmt *DS, CheckerContext &C) const {
ProgramStateRef state = C.getState();
for (DeclStmt::const_decl_iterator I = DS->decl_begin(), E = DS->decl_end();
I != E; ++I) {
const VarDecl *D = dyn_cast<VarDecl>(*I);
if (!D)
continue;
if (!D->getType()->isArrayType())
continue;
const Expr *Init = D->getInit();
if (!Init)
continue;
if (!isa<StringLiteral>(Init))
continue;
Loc VarLoc = state->getLValue(D, C.getLocationContext());
const MemRegion *MR = VarLoc.getAsRegion();
if (!MR)
continue;
SVal StrVal = state->getSVal(Init, C.getLocationContext());
assert(StrVal.isValid() && "Initializer string is unknown or undefined");
DefinedOrUnknownSVal strLength
= cast<DefinedOrUnknownSVal>(getCStringLength(C, state, Init, StrVal));
state = state->set<CStringLength>(MR, strLength);
}
C.addTransition(state);
}
bool CStringChecker::wantsRegionChangeUpdate(ProgramStateRef state) const {
CStringLength::EntryMap Entries = state->get<CStringLength>();
return !Entries.isEmpty();
}
ProgramStateRef
CStringChecker::checkRegionChanges(ProgramStateRef state,
const StoreManager::InvalidatedSymbols *,
ArrayRef<const MemRegion *> ExplicitRegions,
ArrayRef<const MemRegion *> Regions,
const CallEvent *Call) const {
CStringLength::EntryMap Entries = state->get<CStringLength>();
if (Entries.isEmpty())
return state;
llvm::SmallPtrSet<const MemRegion *, 8> Invalidated;
llvm::SmallPtrSet<const MemRegion *, 32> SuperRegions;
for (ArrayRef<const MemRegion *>::iterator
I = Regions.begin(), E = Regions.end(); I != E; ++I) {
const MemRegion *MR = *I;
Invalidated.insert(MR);
SuperRegions.insert(MR);
while (const SubRegion *SR = dyn_cast<SubRegion>(MR)) {
MR = SR->getSuperRegion();
SuperRegions.insert(MR);
}
}
CStringLength::EntryMap::Factory &F = state->get_context<CStringLength>();
for (CStringLength::EntryMap::iterator I = Entries.begin(),
E = Entries.end(); I != E; ++I) {
const MemRegion *MR = I.getKey();
if (SuperRegions.count(MR)) {
Entries = F.remove(Entries, MR);
continue;
}
const MemRegion *Super = MR;
while (const SubRegion *SR = dyn_cast<SubRegion>(Super)) {
Super = SR->getSuperRegion();
if (Invalidated.count(Super)) {
Entries = F.remove(Entries, MR);
break;
}
}
}
return state->set<CStringLength>(Entries);
}
void CStringChecker::checkLiveSymbols(ProgramStateRef state,
SymbolReaper &SR) const {
CStringLength::EntryMap Entries = state->get<CStringLength>();
for (CStringLength::EntryMap::iterator I = Entries.begin(), E = Entries.end();
I != E; ++I) {
SVal Len = I.getData();
for (SymExpr::symbol_iterator si = Len.symbol_begin(),
se = Len.symbol_end(); si != se; ++si)
SR.markInUse(*si);
}
}
void CStringChecker::checkDeadSymbols(SymbolReaper &SR,
CheckerContext &C) const {
if (!SR.hasDeadSymbols())
return;
ProgramStateRef state = C.getState();
CStringLength::EntryMap Entries = state->get<CStringLength>();
if (Entries.isEmpty())
return;
CStringLength::EntryMap::Factory &F = state->get_context<CStringLength>();
for (CStringLength::EntryMap::iterator I = Entries.begin(), E = Entries.end();
I != E; ++I) {
SVal Len = I.getData();
if (SymbolRef Sym = Len.getAsSymbol()) {
if (SR.isDead(Sym))
Entries = F.remove(Entries, I.getKey());
}
}
state = state->set<CStringLength>(Entries);
C.addTransition(state);
}
#define REGISTER_CHECKER(name) \
void ento::register##name(CheckerManager &mgr) {\
static CStringChecker *TheChecker = 0; \
if (TheChecker == 0) \
TheChecker = mgr.registerChecker<CStringChecker>(); \
TheChecker->Filter.Check##name = true; \
}
REGISTER_CHECKER(CStringNullArg)
REGISTER_CHECKER(CStringOutOfBounds)
REGISTER_CHECKER(CStringBufferOverlap)
REGISTER_CHECKER(CStringNotNullTerm)
void ento::registerCStringCheckerBasic(CheckerManager &Mgr) {
registerCStringNullArg(Mgr);
}