//= CStringChecker.h - Checks calls to C string functions ----------*- C++ -*-//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This defines CStringChecker, which is an assortment of checks on calls
// to functions in <string.h>.
//
//===----------------------------------------------------------------------===//
#include "ClangSACheckers.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/GRStateTrait.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 llvm::OwningPtr<BugType> BT_Null, BT_Bounds, BT_BoundsWrite,
BT_Overlap, BT_NotCString;
public:
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(const GRState *state, SymbolReaper &SR) const;
void checkDeadSymbols(SymbolReaper &SR, CheckerContext &C) const;
bool wantsRegionChangeUpdate(const GRState *state) const;
const GRState *checkRegionChanges(const GRState *state,
const StoreManager::InvalidatedSymbols *,
const MemRegion * const *Begin,
const MemRegion * const *End) 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,
const GRState *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;
// Utility methods
std::pair<const GRState*, const GRState*>
static assumeZero(CheckerContext &C,
const GRState *state, SVal V, QualType Ty);
static const GRState *setCStringLength(const GRState *state,
const MemRegion *MR, SVal strLength);
static SVal getCStringLengthForRegion(CheckerContext &C,
const GRState *&state,
const Expr *Ex, const MemRegion *MR);
SVal getCStringLength(CheckerContext &C, const GRState *&state,
const Expr *Ex, SVal Buf) const;
const StringLiteral *getCStringLiteral(CheckerContext &C,
const GRState *&state,
const Expr *expr,
SVal val) const;
static const GRState *InvalidateBuffer(CheckerContext &C,
const GRState *state,
const Expr *Ex, SVal V);
static bool SummarizeRegion(llvm::raw_ostream& os, ASTContext& Ctx,
const MemRegion *MR);
// Re-usable checks
const GRState *checkNonNull(CheckerContext &C, const GRState *state,
const Expr *S, SVal l) const;
const GRState *CheckLocation(CheckerContext &C, const GRState *state,
const Expr *S, SVal l,
bool IsDestination = false) const;
const GRState *CheckBufferAccess(CheckerContext &C, const GRState *state,
const Expr *Size,
const Expr *FirstBuf,
const Expr *SecondBuf = NULL,
bool FirstIsDestination = false) const;
const GRState *CheckOverlap(CheckerContext &C, const GRState *state,
const Expr *Size, const Expr *First,
const Expr *Second) const;
void emitOverlapBug(CheckerContext &C, const GRState *state,
const Stmt *First, const Stmt *Second) const;
};
class CStringLength {
public:
typedef llvm::ImmutableMap<const MemRegion *, SVal> EntryMap;
};
} //end anonymous namespace
namespace clang {
namespace ento {
template <>
struct GRStateTrait<CStringLength>
: public GRStatePartialTrait<CStringLength::EntryMap> {
static void *GDMIndex() { return CStringChecker::getTag(); }
};
}
}
//===----------------------------------------------------------------------===//
// Individual checks and utility methods.
//===----------------------------------------------------------------------===//
std::pair<const GRState*, const GRState*>
CStringChecker::assumeZero(CheckerContext &C, const GRState *state, SVal V,
QualType Ty) {
DefinedSVal *val = dyn_cast<DefinedSVal>(&V);
if (!val)
return std::pair<const GRState*, const GRState *>(state, state);
SValBuilder &svalBuilder = C.getSValBuilder();
DefinedOrUnknownSVal zero = svalBuilder.makeZeroVal(Ty);
return state->assume(svalBuilder.evalEQ(state, *val, zero));
}
const GRState *CStringChecker::checkNonNull(CheckerContext &C,
const GRState *state,
const Expr *S, SVal l) const {
// If a previous check has failed, propagate the failure.
if (!state)
return NULL;
const GRState *stateNull, *stateNonNull;
llvm::tie(stateNull, stateNonNull) = assumeZero(C, state, l, S->getType());
if (stateNull && !stateNonNull) {
ExplodedNode *N = C.generateSink(stateNull);
if (!N)
return NULL;
if (!BT_Null)
BT_Null.reset(new BuiltinBug("API",
"Null pointer argument in call to byte string function"));
// Generate a report for this bug.
BuiltinBug *BT = static_cast<BuiltinBug*>(BT_Null.get());
EnhancedBugReport *report = new EnhancedBugReport(*BT,
BT->getDescription(), N);
report->addRange(S->getSourceRange());
report->addVisitorCreator(bugreporter::registerTrackNullOrUndefValue, S);
C.EmitReport(report);
return NULL;
}
// From here on, assume that the value is non-null.
assert(stateNonNull);
return stateNonNull;
}
// FIXME: This was originally copied from ArrayBoundChecker.cpp. Refactor?
const GRState *CStringChecker::CheckLocation(CheckerContext &C,
const GRState *state,
const Expr *S, SVal l,
bool IsDestination) const {
// If a previous check has failed, propagate the failure.
if (!state)
return NULL;
// Check for out of bound array element access.
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");
// Get the size of the array.
const SubRegion *superReg = cast<SubRegion>(ER->getSuperRegion());
SValBuilder &svalBuilder = C.getSValBuilder();
SVal Extent = svalBuilder.convertToArrayIndex(superReg->getExtent(svalBuilder));
DefinedOrUnknownSVal Size = cast<DefinedOrUnknownSVal>(Extent);
// Get the index of the accessed element.
DefinedOrUnknownSVal Idx = cast<DefinedOrUnknownSVal>(ER->getIndex());
const GRState *StInBound = state->assumeInBound(Idx, Size, true);
const GRState *StOutBound = state->assumeInBound(Idx, Size, false);
if (StOutBound && !StInBound) {
ExplodedNode *N = C.generateSink(StOutBound);
if (!N)
return NULL;
BuiltinBug *BT;
if (IsDestination) {
if (!BT_BoundsWrite) {
BT_BoundsWrite.reset(new BuiltinBug("Out-of-bound array access",
"Byte string function overflows destination buffer"));
}
BT = static_cast<BuiltinBug*>(BT_BoundsWrite.get());
} else {
if (!BT_Bounds) {
BT_Bounds.reset(new BuiltinBug("Out-of-bound array access",
"Byte string function accesses out-of-bound array element"));
}
BT = static_cast<BuiltinBug*>(BT_Bounds.get());
}
// FIXME: It would be nice to eventually make this diagnostic more clear,
// e.g., by referencing the original declaration or by saying *why* this
// reference is outside the range.
// Generate a report for this bug.
RangedBugReport *report = new RangedBugReport(*BT, BT->getDescription(), N);
report->addRange(S->getSourceRange());
C.EmitReport(report);
return NULL;
}
// Array bound check succeeded. From this point forward the array bound
// should always succeed.
return StInBound;
}
const GRState *CStringChecker::CheckBufferAccess(CheckerContext &C,
const GRState *state,
const Expr *Size,
const Expr *FirstBuf,
const Expr *SecondBuf,
bool FirstIsDestination) const {
// If a previous check has failed, propagate the failure.
if (!state)
return NULL;
SValBuilder &svalBuilder = C.getSValBuilder();
ASTContext &Ctx = C.getASTContext();
QualType sizeTy = Size->getType();
QualType PtrTy = Ctx.getPointerType(Ctx.CharTy);
// Check that the first buffer is non-null.
SVal BufVal = state->getSVal(FirstBuf);
state = checkNonNull(C, state, FirstBuf, BufVal);
if (!state)
return NULL;
// Get the access length and make sure it is known.
SVal LengthVal = state->getSVal(Size);
NonLoc *Length = dyn_cast<NonLoc>(&LengthVal);
if (!Length)
return state;
// Compute the offset of the last element to be accessed: size-1.
NonLoc One = cast<NonLoc>(svalBuilder.makeIntVal(1, sizeTy));
NonLoc LastOffset = cast<NonLoc>(svalBuilder.evalBinOpNN(state, BO_Sub,
*Length, One, sizeTy));
// Check that the first buffer is sufficiently long.
SVal BufStart = svalBuilder.evalCast(BufVal, PtrTy, FirstBuf->getType());
if (Loc *BufLoc = dyn_cast<Loc>(&BufStart)) {
SVal BufEnd = svalBuilder.evalBinOpLN(state, BO_Add, *BufLoc,
LastOffset, PtrTy);
state = CheckLocation(C, state, FirstBuf, BufEnd, FirstIsDestination);
// If the buffer isn't large enough, abort.
if (!state)
return NULL;
}
// If there's a second buffer, check it as well.
if (SecondBuf) {
BufVal = state->getSVal(SecondBuf);
state = checkNonNull(C, state, SecondBuf, BufVal);
if (!state)
return NULL;
BufStart = svalBuilder.evalCast(BufVal, PtrTy, SecondBuf->getType());
if (Loc *BufLoc = dyn_cast<Loc>(&BufStart)) {
SVal BufEnd = svalBuilder.evalBinOpLN(state, BO_Add, *BufLoc,
LastOffset, PtrTy);
state = CheckLocation(C, state, SecondBuf, BufEnd);
}
}
// Large enough or not, return this state!
return state;
}
const GRState *CStringChecker::CheckOverlap(CheckerContext &C,
const GRState *state,
const Expr *Size,
const Expr *First,
const Expr *Second) const {
// Do a simple check for overlap: if the two arguments are from the same
// buffer, see if the end of the first is greater than the start of the second
// or vice versa.
// If a previous check has failed, propagate the failure.
if (!state)
return NULL;
const GRState *stateTrue, *stateFalse;
// Get the buffer values and make sure they're known locations.
SVal firstVal = state->getSVal(First);
SVal secondVal = state->getSVal(Second);
Loc *firstLoc = dyn_cast<Loc>(&firstVal);
if (!firstLoc)
return state;
Loc *secondLoc = dyn_cast<Loc>(&secondVal);
if (!secondLoc)
return state;
// Are the two values the same?
SValBuilder &svalBuilder = C.getSValBuilder();
llvm::tie(stateTrue, stateFalse) =
state->assume(svalBuilder.evalEQ(state, *firstLoc, *secondLoc));
if (stateTrue && !stateFalse) {
// If the values are known to be equal, that's automatically an overlap.
emitOverlapBug(C, stateTrue, First, Second);
return NULL;
}
// assume the two expressions are not equal.
assert(stateFalse);
state = stateFalse;
// Which value comes first?
ASTContext &Ctx = svalBuilder.getContext();
QualType cmpTy = Ctx.IntTy;
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) {
// If we don't know which one comes first, we can't perform this test.
return state;
} else {
// Switch the values so that firstVal is before secondVal.
Loc *tmpLoc = firstLoc;
firstLoc = secondLoc;
secondLoc = tmpLoc;
// Switch the Exprs as well, so that they still correspond.
const Expr *tmpExpr = First;
First = Second;
Second = tmpExpr;
}
}
// Get the length, and make sure it too is known.
SVal LengthVal = state->getSVal(Size);
NonLoc *Length = dyn_cast<NonLoc>(&LengthVal);
if (!Length)
return state;
// Convert the first buffer's start address to char*.
// Bail out if the cast fails.
QualType CharPtrTy = Ctx.getPointerType(Ctx.CharTy);
SVal FirstStart = svalBuilder.evalCast(*firstLoc, CharPtrTy, First->getType());
Loc *FirstStartLoc = dyn_cast<Loc>(&FirstStart);
if (!FirstStartLoc)
return state;
// Compute the end of the first buffer. Bail out if THAT fails.
SVal FirstEnd = svalBuilder.evalBinOpLN(state, BO_Add,
*FirstStartLoc, *Length, CharPtrTy);
Loc *FirstEndLoc = dyn_cast<Loc>(&FirstEnd);
if (!FirstEndLoc)
return state;
// Is the end of the first buffer past the start of the second buffer?
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) {
// Overlap!
emitOverlapBug(C, stateTrue, First, Second);
return NULL;
}
// assume the two expressions don't overlap.
assert(stateFalse);
return stateFalse;
}
void CStringChecker::emitOverlapBug(CheckerContext &C, const GRState *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"));
// Generate a report for this bug.
RangedBugReport *report =
new RangedBugReport(*BT_Overlap,
"Arguments must not be overlapping buffers", N);
report->addRange(First->getSourceRange());
report->addRange(Second->getSourceRange());
C.EmitReport(report);
}
const GRState *CStringChecker::setCStringLength(const GRState *state,
const MemRegion *MR,
SVal strLength) {
assert(!strLength.isUndef() && "Attempt to set an undefined string length");
if (strLength.isUnknown())
return state;
MR = MR->StripCasts();
switch (MR->getKind()) {
case MemRegion::StringRegionKind:
// FIXME: This can happen if we strcpy() into a string region. This is
// undefined [C99 6.4.5p6], but we should still warn about it.
return state;
case MemRegion::SymbolicRegionKind:
case MemRegion::AllocaRegionKind:
case MemRegion::VarRegionKind:
case MemRegion::FieldRegionKind:
case MemRegion::ObjCIvarRegionKind:
return state->set<CStringLength>(MR, strLength);
case MemRegion::ElementRegionKind:
// FIXME: Handle element regions by upper-bounding the parent region's
// string length.
return state;
default:
// Other regions (mostly non-data) can't have a reliable C string length.
// For now, just ignore the change.
// FIXME: These are rare but not impossible. We should output some kind of
// warning for things like strcpy((char[]){'a', 0}, "b");
return state;
}
}
SVal CStringChecker::getCStringLengthForRegion(CheckerContext &C,
const GRState *&state,
const Expr *Ex,
const MemRegion *MR) {
// If there's a recorded length, go ahead and return it.
const SVal *Recorded = state->get<CStringLength>(MR);
if (Recorded)
return *Recorded;
// Otherwise, get a new symbol and update the state.
unsigned Count = C.getNodeBuilder().getCurrentBlockCount();
SValBuilder &svalBuilder = C.getSValBuilder();
QualType sizeTy = svalBuilder.getContext().getSizeType();
SVal strLength = svalBuilder.getMetadataSymbolVal(CStringChecker::getTag(),
MR, Ex, sizeTy, Count);
state = state->set<CStringLength>(MR, strLength);
return strLength;
}
SVal CStringChecker::getCStringLength(CheckerContext &C, const GRState *&state,
const Expr *Ex, SVal Buf) const {
const MemRegion *MR = Buf.getAsRegion();
if (!MR) {
// If we can't get a region, see if it's something we /know/ isn't a
// C string. In the context of locations, the only time we can issue such
// a warning is for labels.
if (loc::GotoLabel *Label = dyn_cast<loc::GotoLabel>(&Buf)) {
if (ExplodedNode *N = C.generateNode(state)) {
if (!BT_NotCString)
BT_NotCString.reset(new BuiltinBug("API",
"Argument is not a null-terminated string."));
llvm::SmallString<120> buf;
llvm::raw_svector_ostream os(buf);
os << "Argument to byte string function is the address of the label '"
<< Label->getLabel()->getName()
<< "', which is not a null-terminated string";
// Generate a report for this bug.
EnhancedBugReport *report = new EnhancedBugReport(*BT_NotCString,
os.str(), N);
report->addRange(Ex->getSourceRange());
C.EmitReport(report);
}
return UndefinedVal();
}
// If it's not a region and not a label, give up.
return UnknownVal();
}
// If we have a region, strip casts from it and see if we can figure out
// its length. For anything we can't figure out, just return UnknownVal.
MR = MR->StripCasts();
switch (MR->getKind()) {
case MemRegion::StringRegionKind: {
// Modifying the contents of string regions is undefined [C99 6.4.5p6],
// so we can assume that the byte length is the correct C string length.
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);
case MemRegion::CompoundLiteralRegionKind:
// FIXME: Can we track this? Is it necessary?
return UnknownVal();
case MemRegion::ElementRegionKind:
// FIXME: How can we handle this? It's not good enough to subtract the
// offset from the base string length; consider "123\x00567" and &a[5].
return UnknownVal();
default:
// Other regions (mostly non-data) can't have a reliable C string length.
// In this case, an error is emitted and UndefinedVal is returned.
// The caller should always be prepared to handle this case.
if (ExplodedNode *N = C.generateNode(state)) {
if (!BT_NotCString)
BT_NotCString.reset(new BuiltinBug("API",
"Argument is not a null-terminated string."));
llvm::SmallString<120> buf;
llvm::raw_svector_ostream os(buf);
os << "Argument to byte string function is ";
if (SummarizeRegion(os, C.getASTContext(), MR))
os << ", which is not a null-terminated string";
else
os << "not a null-terminated string";
// Generate a report for this bug.
EnhancedBugReport *report = new EnhancedBugReport(*BT_NotCString,
os.str(), N);
report->addRange(Ex->getSourceRange());
C.EmitReport(report);
}
return UndefinedVal();
}
}
const StringLiteral *CStringChecker::getCStringLiteral(CheckerContext &C,
const GRState *&state, const Expr *expr, SVal val) const {
// Get the memory region pointed to by the val.
const MemRegion *bufRegion = val.getAsRegion();
if (!bufRegion)
return NULL;
// Strip casts off the memory region.
bufRegion = bufRegion->StripCasts();
// Cast the memory region to a string region.
const StringRegion *strRegion= dyn_cast<StringRegion>(bufRegion);
if (!strRegion)
return NULL;
// Return the actual string in the string region.
return strRegion->getStringLiteral();
}
const GRState *CStringChecker::InvalidateBuffer(CheckerContext &C,
const GRState *state,
const Expr *E, SVal V) {
Loc *L = dyn_cast<Loc>(&V);
if (!L)
return state;
// FIXME: This is a simplified version of what's in CFRefCount.cpp -- it makes
// some assumptions about the value that CFRefCount can't. Even so, it should
// probably be refactored.
if (loc::MemRegionVal* MR = dyn_cast<loc::MemRegionVal>(L)) {
const MemRegion *R = MR->getRegion()->StripCasts();
// Are we dealing with an ElementRegion? If so, we should be invalidating
// the super-region.
if (const ElementRegion *ER = dyn_cast<ElementRegion>(R)) {
R = ER->getSuperRegion();
// FIXME: What about layers of ElementRegions?
}
// Invalidate this region.
unsigned Count = C.getNodeBuilder().getCurrentBlockCount();
return state->invalidateRegion(R, E, Count, NULL);
}
// If we have a non-region value by chance, just remove the binding.
// FIXME: is this necessary or correct? This handles the non-Region
// cases. Is it ever valid to store to these?
return state->unbindLoc(*L);
}
bool CStringChecker::SummarizeRegion(llvm::raw_ostream& os, ASTContext& Ctx,
const MemRegion *MR) {
const TypedRegion *TR = dyn_cast<TypedRegion>(MR);
if (!TR)
return false;
switch (TR->getKind()) {
case MemRegion::FunctionTextRegionKind: {
const FunctionDecl *FD = cast<FunctionTextRegion>(TR)->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 " << TR->getValueType().getAsString();
return true;
case MemRegion::VarRegionKind:
os << "a variable of type" << TR->getValueType().getAsString();
return true;
case MemRegion::FieldRegionKind:
os << "a field of type " << TR->getValueType().getAsString();
return true;
case MemRegion::ObjCIvarRegionKind:
os << "an instance variable of type " << TR->getValueType().getAsString();
return true;
default:
return false;
}
}
//===----------------------------------------------------------------------===//
// evaluation of individual function calls.
//===----------------------------------------------------------------------===//
void CStringChecker::evalCopyCommon(CheckerContext &C,
const CallExpr *CE,
const GRState *state,
const Expr *Size, const Expr *Dest,
const Expr *Source, bool Restricted,
bool IsMempcpy) const {
// See if the size argument is zero.
SVal sizeVal = state->getSVal(Size);
QualType sizeTy = Size->getType();
const GRState *stateZeroSize, *stateNonZeroSize;
llvm::tie(stateZeroSize, stateNonZeroSize) = assumeZero(C, state, sizeVal, sizeTy);
// Get the value of the Dest.
SVal destVal = state->getSVal(Dest);
// If the size is zero, there won't be any actual memory access, so
// just bind the return value to the destination buffer and return.
if (stateZeroSize) {
stateZeroSize = stateZeroSize->BindExpr(CE, destVal);
C.addTransition(stateZeroSize);
}
// If the size can be nonzero, we have to check the other arguments.
if (stateNonZeroSize) {
state = stateNonZeroSize;
// Ensure the destination is not null. If it is NULL there will be a
// NULL pointer dereference.
state = checkNonNull(C, state, Dest, destVal);
if (!state)
return;
// Get the value of the Src.
SVal srcVal = state->getSVal(Source);
// Ensure the source is not null. If it is NULL there will be a
// NULL pointer dereference.
state = checkNonNull(C, state, Source, srcVal);
if (!state)
return;
// Ensure the accesses are valid and that the buffers do not overlap.
state = CheckBufferAccess(C, state, Size, Dest, Source,
/* FirstIsDst = */ true);
if (Restricted)
state = CheckOverlap(C, state, Size, Dest, Source);
if (!state)
return;
// If this is mempcpy, get the byte after the last byte copied and
// bind the expr.
if (IsMempcpy) {
loc::MemRegionVal *destRegVal = dyn_cast<loc::MemRegionVal>(&destVal);
assert(destRegVal && "Destination should be a known MemRegionVal here");
// Get the length to copy.
NonLoc *lenValNonLoc = dyn_cast<NonLoc>(&sizeVal);
if (lenValNonLoc) {
// Get the byte after the last byte copied.
SVal lastElement = C.getSValBuilder().evalBinOpLN(state, BO_Add,
*destRegVal,
*lenValNonLoc,
Dest->getType());
// The byte after the last byte copied is the return value.
state = state->BindExpr(CE, lastElement);
} else {
// If we don't know how much we copied, we can at least
// conjure a return value for later.
unsigned Count = C.getNodeBuilder().getCurrentBlockCount();
SVal result =
C.getSValBuilder().getConjuredSymbolVal(NULL, CE, Count);
state = state->BindExpr(CE, result);
}
} else {
// All other copies return the destination buffer.
// (Well, bcopy() has a void return type, but this won't hurt.)
state = state->BindExpr(CE, destVal);
}
// Invalidate the destination.
// FIXME: Even if we can't perfectly model the copy, we should see if we
// can use LazyCompoundVals to copy the source values into the destination.
// This would probably remove any existing bindings past the end of the
// copied region, but that's still an improvement over blank invalidation.
state = InvalidateBuffer(C, state, Dest, state->getSVal(Dest));
C.addTransition(state);
}
}
void CStringChecker::evalMemcpy(CheckerContext &C, const CallExpr *CE) const {
// void *memcpy(void *restrict dst, const void *restrict src, size_t n);
// The return value is the address of the destination buffer.
const Expr *Dest = CE->getArg(0);
const GRState *state = C.getState();
evalCopyCommon(C, CE, state, CE->getArg(2), Dest, CE->getArg(1), true);
}
void CStringChecker::evalMempcpy(CheckerContext &C, const CallExpr *CE) const {
// void *mempcpy(void *restrict dst, const void *restrict src, size_t n);
// The return value is a pointer to the byte following the last written byte.
const Expr *Dest = CE->getArg(0);
const GRState *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 {
// void *memmove(void *dst, const void *src, size_t n);
// The return value is the address of the destination buffer.
const Expr *Dest = CE->getArg(0);
const GRState *state = C.getState();
evalCopyCommon(C, CE, state, CE->getArg(2), Dest, CE->getArg(1));
}
void CStringChecker::evalBcopy(CheckerContext &C, const CallExpr *CE) const {
// void bcopy(const void *src, void *dst, size_t n);
evalCopyCommon(C, CE, C.getState(),
CE->getArg(2), CE->getArg(1), CE->getArg(0));
}
void CStringChecker::evalMemcmp(CheckerContext &C, const CallExpr *CE) const {
// int memcmp(const void *s1, const void *s2, size_t n);
const Expr *Left = CE->getArg(0);
const Expr *Right = CE->getArg(1);
const Expr *Size = CE->getArg(2);
const GRState *state = C.getState();
SValBuilder &svalBuilder = C.getSValBuilder();
// See if the size argument is zero.
SVal sizeVal = state->getSVal(Size);
QualType sizeTy = Size->getType();
const GRState *stateZeroSize, *stateNonZeroSize;
llvm::tie(stateZeroSize, stateNonZeroSize) =
assumeZero(C, state, sizeVal, sizeTy);
// If the size can be zero, the result will be 0 in that case, and we don't
// have to check either of the buffers.
if (stateZeroSize) {
state = stateZeroSize;
state = state->BindExpr(CE, svalBuilder.makeZeroVal(CE->getType()));
C.addTransition(state);
}
// If the size can be nonzero, we have to check the other arguments.
if (stateNonZeroSize) {
state = stateNonZeroSize;
// If we know the two buffers are the same, we know the result is 0.
// First, get the two buffers' addresses. Another checker will have already
// made sure they're not undefined.
DefinedOrUnknownSVal LV = cast<DefinedOrUnknownSVal>(state->getSVal(Left));
DefinedOrUnknownSVal RV = cast<DefinedOrUnknownSVal>(state->getSVal(Right));
// See if they are the same.
DefinedOrUnknownSVal SameBuf = svalBuilder.evalEQ(state, LV, RV);
const GRState *StSameBuf, *StNotSameBuf;
llvm::tie(StSameBuf, StNotSameBuf) = state->assume(SameBuf);
// If the two arguments might be the same buffer, we know the result is zero,
// and we only need to check one size.
if (StSameBuf) {
state = StSameBuf;
state = CheckBufferAccess(C, state, Size, Left);
if (state) {
state = StSameBuf->BindExpr(CE, svalBuilder.makeZeroVal(CE->getType()));
C.addTransition(state);
}
}
// If the two arguments might be different buffers, we have to check the
// size of both of them.
if (StNotSameBuf) {
state = StNotSameBuf;
state = CheckBufferAccess(C, state, Size, Left, Right);
if (state) {
// The return value is the comparison result, which we don't know.
unsigned Count = C.getNodeBuilder().getCurrentBlockCount();
SVal CmpV = svalBuilder.getConjuredSymbolVal(NULL, CE, Count);
state = state->BindExpr(CE, CmpV);
C.addTransition(state);
}
}
}
}
void CStringChecker::evalstrLength(CheckerContext &C,
const CallExpr *CE) const {
// size_t strlen(const char *s);
evalstrLengthCommon(C, CE, /* IsStrnlen = */ false);
}
void CStringChecker::evalstrnLength(CheckerContext &C,
const CallExpr *CE) const {
// size_t strnlen(const char *s, size_t maxlen);
evalstrLengthCommon(C, CE, /* IsStrnlen = */ true);
}
void CStringChecker::evalstrLengthCommon(CheckerContext &C, const CallExpr *CE,
bool IsStrnlen) const {
const GRState *state = C.getState();
const Expr *Arg = CE->getArg(0);
SVal ArgVal = state->getSVal(Arg);
// Check that the argument is non-null.
state = checkNonNull(C, state, Arg, ArgVal);
if (state) {
SVal strLength = getCStringLength(C, state, Arg, ArgVal);
// If the argument isn't a valid C string, there's no valid state to
// transition to.
if (strLength.isUndef())
return;
// If the check is for strnlen() then bind the return value to no more than
// the maxlen value.
if (IsStrnlen) {
const Expr *maxlenExpr = CE->getArg(1);
SVal maxlenVal = state->getSVal(maxlenExpr);
NonLoc *strLengthNL = dyn_cast<NonLoc>(&strLength);
NonLoc *maxlenValNL = dyn_cast<NonLoc>(&maxlenVal);
QualType cmpTy = C.getSValBuilder().getContext().IntTy;
const GRState *stateTrue, *stateFalse;
// Check if the strLength is greater than or equal to the maxlen
llvm::tie(stateTrue, stateFalse) =
state->assume(cast<DefinedOrUnknownSVal>
(C.getSValBuilder().evalBinOpNN(state, BO_GE,
*strLengthNL, *maxlenValNL,
cmpTy)));
// If the strLength is greater than or equal to the maxlen, set strLength
// to maxlen
if (stateTrue && !stateFalse) {
strLength = maxlenVal;
}
}
// If getCStringLength couldn't figure out the length, conjure a return
// value, so it can be used in constraints, at least.
if (strLength.isUnknown()) {
unsigned Count = C.getNodeBuilder().getCurrentBlockCount();
strLength = C.getSValBuilder().getConjuredSymbolVal(NULL, CE, Count);
}
// Bind the return value.
state = state->BindExpr(CE, strLength);
C.addTransition(state);
}
}
void CStringChecker::evalStrcpy(CheckerContext &C, const CallExpr *CE) const {
// char *strcpy(char *restrict dst, const char *restrict src);
evalStrcpyCommon(C, CE,
/* returnEnd = */ false,
/* isBounded = */ false,
/* isAppending = */ false);
}
void CStringChecker::evalStrncpy(CheckerContext &C, const CallExpr *CE) const {
// char *strncpy(char *restrict dst, const char *restrict src, size_t n);
evalStrcpyCommon(C, CE,
/* returnEnd = */ false,
/* isBounded = */ true,
/* isAppending = */ false);
}
void CStringChecker::evalStpcpy(CheckerContext &C, const CallExpr *CE) const {
// char *stpcpy(char *restrict dst, const char *restrict src);
evalStrcpyCommon(C, CE,
/* returnEnd = */ true,
/* isBounded = */ false,
/* isAppending = */ false);
}
void CStringChecker::evalStrcat(CheckerContext &C, const CallExpr *CE) const {
//char *strcat(char *restrict s1, const char *restrict s2);
evalStrcpyCommon(C, CE,
/* returnEnd = */ false,
/* isBounded = */ false,
/* isAppending = */ true);
}
void CStringChecker::evalStrncat(CheckerContext &C, const CallExpr *CE) const {
//char *strncat(char *restrict s1, const char *restrict s2, size_t n);
evalStrcpyCommon(C, CE,
/* returnEnd = */ false,
/* isBounded = */ true,
/* isAppending = */ true);
}
void CStringChecker::evalStrcpyCommon(CheckerContext &C, const CallExpr *CE,
bool returnEnd, bool isBounded,
bool isAppending) const {
const GRState *state = C.getState();
// Check that the destination is non-null.
const Expr *Dst = CE->getArg(0);
SVal DstVal = state->getSVal(Dst);
state = checkNonNull(C, state, Dst, DstVal);
if (!state)
return;
// Check that the source is non-null.
const Expr *srcExpr = CE->getArg(1);
SVal srcVal = state->getSVal(srcExpr);
state = checkNonNull(C, state, srcExpr, srcVal);
if (!state)
return;
// Get the string length of the source.
SVal strLength = getCStringLength(C, state, srcExpr, srcVal);
// If the source isn't a valid C string, give up.
if (strLength.isUndef())
return;
// If the function is strncpy, strncat, etc... it is bounded.
if (isBounded) {
// Get the max number of characters to copy.
const Expr *lenExpr = CE->getArg(2);
SVal lenVal = state->getSVal(lenExpr);
// Cast the length to a NonLoc SVal. If it is not a NonLoc then give up.
NonLoc *strLengthNL = dyn_cast<NonLoc>(&strLength);
if (!strLengthNL)
return;
// Cast the max length to a NonLoc SVal. If it is not a NonLoc then give up.
NonLoc *lenValNL = dyn_cast<NonLoc>(&lenVal);
if (!lenValNL)
return;
QualType cmpTy = C.getSValBuilder().getContext().IntTy;
const GRState *stateTrue, *stateFalse;
// Check if the max number to copy is less than the length of the src.
llvm::tie(stateTrue, stateFalse) =
state->assume(cast<DefinedOrUnknownSVal>
(C.getSValBuilder().evalBinOpNN(state, BO_GT,
*strLengthNL, *lenValNL,
cmpTy)));
if (stateTrue) {
// Max number to copy is less than the length of the src, so the actual
// strLength copied is the max number arg.
strLength = lenVal;
}
}
// If this is an appending function (strcat, strncat...) then set the
// string length to strlen(src) + strlen(dst) since the buffer will
// ultimately contain both.
if (isAppending) {
// Get the string length of the destination, or give up.
SVal dstStrLength = getCStringLength(C, state, Dst, DstVal);
if (dstStrLength.isUndef())
return;
NonLoc *srcStrLengthNL = dyn_cast<NonLoc>(&strLength);
NonLoc *dstStrLengthNL = dyn_cast<NonLoc>(&dstStrLength);
// If src or dst cast to NonLoc is NULL, give up.
if ((!srcStrLengthNL) || (!dstStrLengthNL))
return;
QualType addTy = C.getSValBuilder().getContext().getSizeType();
strLength = C.getSValBuilder().evalBinOpNN(state, BO_Add,
*srcStrLengthNL, *dstStrLengthNL,
addTy);
}
SVal Result = (returnEnd ? UnknownVal() : DstVal);
// If the destination is a MemRegion, try to check for a buffer overflow and
// record the new string length.
if (loc::MemRegionVal *dstRegVal = dyn_cast<loc::MemRegionVal>(&DstVal)) {
// If the length is known, we can check for an overflow.
if (NonLoc *knownStrLength = dyn_cast<NonLoc>(&strLength)) {
SVal lastElement =
C.getSValBuilder().evalBinOpLN(state, BO_Add, *dstRegVal,
*knownStrLength, Dst->getType());
state = CheckLocation(C, state, Dst, lastElement, /* IsDst = */ true);
if (!state)
return;
// If this is a stpcpy-style copy, the last element is the return value.
if (returnEnd)
Result = lastElement;
}
// Invalidate the destination. This must happen before we set the C string
// length because invalidation will clear the length.
// FIXME: Even if we can't perfectly model the copy, we should see if we
// can use LazyCompoundVals to copy the source values into the destination.
// This would probably remove any existing bindings past the end of the
// string, but that's still an improvement over blank invalidation.
state = InvalidateBuffer(C, state, Dst, *dstRegVal);
// Set the C string length of the destination.
state = setCStringLength(state, dstRegVal->getRegion(), strLength);
}
// If this is a stpcpy-style copy, but we were unable to check for a buffer
// overflow, we still need a result. Conjure a return value.
if (returnEnd && Result.isUnknown()) {
SValBuilder &svalBuilder = C.getSValBuilder();
unsigned Count = C.getNodeBuilder().getCurrentBlockCount();
strLength = svalBuilder.getConjuredSymbolVal(NULL, CE, Count);
}
// Set the return value.
state = state->BindExpr(CE, Result);
C.addTransition(state);
}
void CStringChecker::evalStrcmp(CheckerContext &C, const CallExpr *CE) const {
//int strcmp(const char *restrict s1, const char *restrict s2);
evalStrcmpCommon(C, CE, /* isBounded = */ false, /* ignoreCase = */ false);
}
void CStringChecker::evalStrncmp(CheckerContext &C, const CallExpr *CE) const {
//int strncmp(const char *restrict s1, const char *restrict s2, size_t n);
evalStrcmpCommon(C, CE, /* isBounded = */ true, /* ignoreCase = */ false);
}
void CStringChecker::evalStrcasecmp(CheckerContext &C,
const CallExpr *CE) const {
//int strcasecmp(const char *restrict s1, const char *restrict s2);
evalStrcmpCommon(C, CE, /* isBounded = */ false, /* ignoreCase = */ true);
}
void CStringChecker::evalStrncasecmp(CheckerContext &C,
const CallExpr *CE) const {
//int strncasecmp(const char *restrict s1, const char *restrict s2, size_t n);
evalStrcmpCommon(C, CE, /* isBounded = */ true, /* ignoreCase = */ true);
}
void CStringChecker::evalStrcmpCommon(CheckerContext &C, const CallExpr *CE,
bool isBounded, bool ignoreCase) const {
const GRState *state = C.getState();
// Check that the first string is non-null
const Expr *s1 = CE->getArg(0);
SVal s1Val = state->getSVal(s1);
state = checkNonNull(C, state, s1, s1Val);
if (!state)
return;
// Check that the second string is non-null.
const Expr *s2 = CE->getArg(1);
SVal s2Val = state->getSVal(s2);
state = checkNonNull(C, state, s2, s2Val);
if (!state)
return;
// Get the string length of the first string or give up.
SVal s1Length = getCStringLength(C, state, s1, s1Val);
if (s1Length.isUndef())
return;
// Get the string length of the second string or give up.
SVal s2Length = getCStringLength(C, state, s2, s2Val);
if (s2Length.isUndef())
return;
// Get the string literal of the first string.
const StringLiteral *s1StrLiteral = getCStringLiteral(C, state, s1, s1Val);
if (!s1StrLiteral)
return;
llvm::StringRef s1StrRef = s1StrLiteral->getString();
// Get the string literal of the second string.
const StringLiteral *s2StrLiteral = getCStringLiteral(C, state, s2, s2Val);
if (!s2StrLiteral)
return;
llvm::StringRef s2StrRef = s2StrLiteral->getString();
int result;
if (isBounded) {
// Get the max number of characters to compare.
const Expr *lenExpr = CE->getArg(2);
SVal lenVal = state->getSVal(lenExpr);
// Dynamically cast the length to a ConcreteInt. If it is not a ConcreteInt
// then give up, otherwise get the value and use it as the bounds.
nonloc::ConcreteInt *CI = dyn_cast<nonloc::ConcreteInt>(&lenVal);
if (!CI)
return;
llvm::APSInt lenInt(CI->getValue());
// Create substrings of each to compare the prefix.
s1StrRef = s1StrRef.substr(0, (size_t)lenInt.getLimitedValue());
s2StrRef = s2StrRef.substr(0, (size_t)lenInt.getLimitedValue());
}
if (ignoreCase) {
// Compare string 1 to string 2 the same way strcasecmp() does.
result = s1StrRef.compare_lower(s2StrRef);
} else {
// Compare string 1 to string 2 the same way strcmp() does.
result = s1StrRef.compare(s2StrRef);
}
// Build the SVal of the comparison to bind the return value.
SValBuilder &svalBuilder = C.getSValBuilder();
QualType intTy = svalBuilder.getContext().IntTy;
SVal resultVal = svalBuilder.makeIntVal(result, intTy);
// Bind the return value of the expression.
// Set the return value.
state = state->BindExpr(CE, resultVal);
C.addTransition(state);
}
//===----------------------------------------------------------------------===//
// The driver method, and other Checker callbacks.
//===----------------------------------------------------------------------===//
bool CStringChecker::evalCall(const CallExpr *CE, CheckerContext &C) const {
// Get the callee. All the functions we care about are C functions
// with simple identifiers.
const GRState *state = C.getState();
const Expr *Callee = CE->getCallee();
const FunctionDecl *FD = state->getSVal(Callee).getAsFunctionDecl();
if (!FD)
return false;
// Get the name of the callee. If it's a builtin, strip off the prefix.
IdentifierInfo *II = FD->getIdentifier();
if (!II) // if no identifier, not a simple C function
return false;
llvm::StringRef Name = II->getName();
if (Name.startswith("__builtin_"))
Name = Name.substr(10);
FnCheck evalFunction = llvm::StringSwitch<FnCheck>(Name)
.Cases("memcpy", "__memcpy_chk", &CStringChecker::evalMemcpy)
.Cases("mempcpy", "__mempcpy_chk", &CStringChecker::evalMempcpy)
.Cases("memcmp", "bcmp", &CStringChecker::evalMemcmp)
.Cases("memmove", "__memmove_chk", &CStringChecker::evalMemmove)
.Cases("strcpy", "__strcpy_chk", &CStringChecker::evalStrcpy)
//.Cases("strncpy", "__strncpy_chk", &CStringChecker::evalStrncpy)
.Cases("stpcpy", "__stpcpy_chk", &CStringChecker::evalStpcpy)
.Cases("strcat", "__strcat_chk", &CStringChecker::evalStrcat)
.Cases("strncat", "__strncat_chk", &CStringChecker::evalStrncat)
.Case("strlen", &CStringChecker::evalstrLength)
.Case("strnlen", &CStringChecker::evalstrnLength)
.Case("strcmp", &CStringChecker::evalStrcmp)
.Case("strncmp", &CStringChecker::evalStrncmp)
.Case("strcasecmp", &CStringChecker::evalStrcasecmp)
.Case("strncasecmp", &CStringChecker::evalStrncasecmp)
.Case("bcopy", &CStringChecker::evalBcopy)
.Default(NULL);
// If the callee isn't a string function, let another checker handle it.
if (!evalFunction)
return false;
// Check and evaluate the call.
(this->*evalFunction)(C, CE);
return true;
}
void CStringChecker::checkPreStmt(const DeclStmt *DS, CheckerContext &C) const {
// Record string length for char a[] = "abc";
const GRState *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;
// FIXME: Handle array fields of structs.
if (!D->getType()->isArrayType())
continue;
const Expr *Init = D->getInit();
if (!Init)
continue;
if (!isa<StringLiteral>(Init))
continue;
Loc VarLoc = state->getLValue(D, C.getPredecessor()->getLocationContext());
const MemRegion *MR = VarLoc.getAsRegion();
if (!MR)
continue;
SVal StrVal = state->getSVal(Init);
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(const GRState *state) const {
CStringLength::EntryMap Entries = state->get<CStringLength>();
return !Entries.isEmpty();
}
const GRState *
CStringChecker::checkRegionChanges(const GRState *state,
const StoreManager::InvalidatedSymbols *,
const MemRegion * const *Begin,
const MemRegion * const *End) const {
CStringLength::EntryMap Entries = state->get<CStringLength>();
if (Entries.isEmpty())
return state;
llvm::SmallPtrSet<const MemRegion *, 8> Invalidated;
llvm::SmallPtrSet<const MemRegion *, 32> SuperRegions;
// First build sets for the changed regions and their super-regions.
for ( ; Begin != End; ++Begin) {
const MemRegion *MR = *Begin;
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>();
// Then loop over the entries in the current state.
for (CStringLength::EntryMap::iterator I = Entries.begin(),
E = Entries.end(); I != E; ++I) {
const MemRegion *MR = I.getKey();
// Is this entry for a super-region of a changed region?
if (SuperRegions.count(MR)) {
Entries = F.remove(Entries, MR);
continue;
}
// Is this entry for a sub-region of a changed region?
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(const GRState *state,
SymbolReaper &SR) const {
// Mark all symbols in our string length map as valid.
CStringLength::EntryMap Entries = state->get<CStringLength>();
for (CStringLength::EntryMap::iterator I = Entries.begin(), E = Entries.end();
I != E; ++I) {
SVal Len = I.getData();
if (SymbolRef Sym = Len.getAsSymbol())
SR.markInUse(Sym);
}
}
void CStringChecker::checkDeadSymbols(SymbolReaper &SR,
CheckerContext &C) const {
if (!SR.hasDeadSymbols())
return;
const GRState *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.generateNode(state);
}
void ento::registerCStringChecker(CheckerManager &mgr) {
mgr.registerChecker<CStringChecker>();
}