[clang] [clang][analyzer] Model more getline/getdelim pre and postconditions (PR #83027)

[Balázs Kéri via cfe-commits]

================
@@ -1158,6 +1173,118 @@ void StreamChecker::evalUngetc(const FnDescription *Desc, const CallEvent &Call,
   C.addTransition(StateFailed);
 }
 
+ProgramStateRef
+StreamChecker::ensurePtrNotNull(SVal PtrVal, const Expr *PtrExpr,
+                                CheckerContext &C, ProgramStateRef State,
+                                const StringRef PtrDescr) const {
----------------
balazske wrote:

This looks like a generally usable function, for example if buffer in `fread` or `fwrite` is checked for null pointer. For this a special bug report for "NULL size" does not work, but a generic NULL pointer bug report can work. Probably this function can be merged with `ensureStreamNonNull` too.

https://github.com/llvm/llvm-project/pull/83027