Eliminates an assert in the strncpy/strncat checker caused by not validating a cast was successful. If the value of an argument was unknown, the cast would result in a NULL pointer which was later being dereferenced.

This fixes Bugzilla #9806.

llvm-svn: 130422

1 files changed, 7 insertions, 0 deletions

diff --git a/clang/lib/StaticAnalyzer/Checkers/CStringChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/CStringChecker.cpp
index 8e9c7899b0d..534b887f3b2 100644
--- a/clang/lib/StaticAnalyzer/Checkers/CStringChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/CStringChecker.cpp
@@ -1017,8 +1017,15 @@ void CStringChecker::evalStrcpyCommon(CheckerContext &C, const CallExpr *CE,
     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;