[Analyzer] Check function name size before indexing.

https://reviews.llvm.org/D37908

llvm-svn: 313385

clang/lib/StaticAnalyzer/Checkers/RetainCountChecker.cpp

@@ -1211,7 +1211,8 @@ RetainSummaryManager::getFunctionSummary(const FunctionDecl *FD) {
 
     // Check for release functions, the only kind of functions that we care
     // about that don't return a pointer type.
-    if (FName[0] == 'C' && (FName[1] == 'F' || FName[1] == 'G')) {
+    if (FName.size() >= 2 &&
+        FName[0] == 'C' && (FName[1] == 'F' || FName[1] == 'G')) {
       // Test for 'CGCF'.
       FName = FName.substr(FName.startswith("CGCF") ? 4 : 2);
 

clang/test/Analysis/retain-release.mm

@@ -461,3 +461,5 @@ void	radar13722286::PrepareBitmap() {
 	}
 }
 
+// rdar://34210609
+void _() { _(); }; // no-warning