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-rw-r--r--lib/StaticAnalyzer/Checkers/CStringChecker.cpp112
1 files changed, 59 insertions, 53 deletions
diff --git a/lib/StaticAnalyzer/Checkers/CStringChecker.cpp b/lib/StaticAnalyzer/Checkers/CStringChecker.cpp
index a6a256a..f2f5c1e 100644
--- a/lib/StaticAnalyzer/Checkers/CStringChecker.cpp
+++ b/lib/StaticAnalyzer/Checkers/CStringChecker.cpp
@@ -42,6 +42,7 @@ public:
bool wantsRegionChangeUpdate(const GRState *state) const;
const GRState *checkRegionChanges(const GRState *state,
+ const StoreManager::InvalidatedSymbols *,
const MemRegion * const *Begin,
const MemRegion * const *End) const;
@@ -77,6 +78,7 @@ public:
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;
@@ -711,16 +713,13 @@ void CStringChecker::evalCopyCommon(CheckerContext &C,
// 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 (IsMempcpy)
- state->BindExpr(CE, destVal);
- else
- state->BindExpr(CE, sizeVal);
- return;
}
// 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.
@@ -737,42 +736,55 @@ void CStringChecker::evalCopyCommon(CheckerContext &C,
if (!state)
return;
- // Ensure the buffers do not overlap.
- state = stateNonZeroSize;
+ // 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) {
-
- // 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);
-
- // Get the length to copy.
- SVal lenVal = state->getSVal(Size);
- NonLoc *lenValNonLoc = dyn_cast<NonLoc>(&lenVal);
-
+ 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);
}
- // 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);
+ } 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);
}
}
@@ -782,7 +794,7 @@ void CStringChecker::evalMemcpy(CheckerContext &C, const CallExpr *CE) const {
// The return value is the address of the destination buffer.
const Expr *Dest = CE->getArg(0);
const GRState *state = C.getState();
- state = state->BindExpr(CE, state->getSVal(Dest));
+
evalCopyCommon(C, CE, state, CE->getArg(2), Dest, CE->getArg(1), true);
}
@@ -800,7 +812,7 @@ void CStringChecker::evalMemmove(CheckerContext &C, const CallExpr *CE) const {
// The return value is the address of the destination buffer.
const Expr *Dest = CE->getArg(0);
const GRState *state = C.getState();
- state = state->BindExpr(CE, state->getSVal(Dest));
+
evalCopyCommon(C, CE, state, CE->getArg(2), Dest, CE->getArg(1));
}
@@ -953,7 +965,7 @@ void CStringChecker::evalStrcpy(CheckerContext &C, const CallExpr *CE) const {
}
void CStringChecker::evalStrncpy(CheckerContext &C, const CallExpr *CE) const {
- // char *strcpy(char *restrict dst, const char *restrict src);
+ // char *strncpy(char *restrict dst, const char *restrict src, size_t n);
evalStrcpyCommon(C, CE,
/* returnEnd = */ false,
/* isBounded = */ true,
@@ -1128,6 +1140,12 @@ void CStringChecker::evalStrcasecmp(CheckerContext &C,
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();
@@ -1181,31 +1199,17 @@ void CStringChecker::evalStrcmpCommon(CheckerContext &C, const CallExpr *CE,
return;
llvm::APSInt lenInt(CI->getValue());
- // Compare using the bounds provided like strncmp() does.
- if (ignoreCase) {
- // TODO Implement compare_lower(RHS, n) in LLVM StringRef.
- // result = s1StrRef.compare_lower(s2StrRef,
- // (size_t)lenInt.getLimitedValue());
+ // Create substrings of each to compare the prefix.
+ s1StrRef = s1StrRef.substr(0, (size_t)lenInt.getLimitedValue());
+ s2StrRef = s2StrRef.substr(0, (size_t)lenInt.getLimitedValue());
+ }
- // For now, give up.
- return;
- } else {
- // Create substrings of each to compare the prefix.
- llvm::StringRef s1SubStr =
- s1StrRef.substr(0, (size_t)lenInt.getLimitedValue());
- llvm::StringRef s2SubStr =
- s2StrRef.substr(0, (size_t)lenInt.getLimitedValue());
-
- // Compare the substrings.
- result = s1SubStr.compare(s2SubStr);
- }
+ 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.
- if (ignoreCase) {
- result = s1StrRef.compare_lower(s2StrRef);
- } else {
- result = s1StrRef.compare(s2StrRef);
- }
+ result = s1StrRef.compare(s2StrRef);
}
// Build the SVal of the comparison to bind the return value.
@@ -1243,11 +1247,11 @@ bool CStringChecker::evalCall(const CallExpr *CE, CheckerContext &C) const {
FnCheck evalFunction = llvm::StringSwitch<FnCheck>(Name)
.Cases("memcpy", "__memcpy_chk", &CStringChecker::evalMemcpy)
- .Case("mempcpy", &CStringChecker::evalMempcpy)
+ .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("strncpy", "__strncpy_chk", &CStringChecker::evalStrncpy)
.Cases("stpcpy", "__stpcpy_chk", &CStringChecker::evalStpcpy)
.Cases("strcat", "__strcat_chk", &CStringChecker::evalStrcat)
.Cases("strncat", "__strncat_chk", &CStringChecker::evalStrncat)
@@ -1256,6 +1260,7 @@ bool CStringChecker::evalCall(const CallExpr *CE, CheckerContext &C) const {
.Case("strcmp", &CStringChecker::evalStrcmp)
.Case("strncmp", &CStringChecker::evalStrncmp)
.Case("strcasecmp", &CStringChecker::evalStrcasecmp)
+ .Case("strncasecmp", &CStringChecker::evalStrncasecmp)
.Case("bcopy", &CStringChecker::evalBcopy)
.Default(NULL);
@@ -1311,6 +1316,7 @@ bool CStringChecker::wantsRegionChangeUpdate(const GRState *state) const {
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>();
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