[clang] [analyzer] New optin.taint.TaintAlloc checker for catching unbounded memory allocation calls (PR #92420)

[Donát Nagy via cfe-commits]

================
@@ -1779,18 +1797,76 @@ ProgramStateRef MallocChecker::MallocMemAux(CheckerContext &C,
                                             const CallEvent &Call,
                                             const Expr *SizeEx, SVal Init,
                                             ProgramStateRef State,
-                                            AllocationFamily Family) {
+                                            AllocationFamily Family) const {
   if (!State)
     return nullptr;
 
   assert(SizeEx);
   return MallocMemAux(C, Call, C.getSVal(SizeEx), Init, State, Family);
 }
 
+void MallocChecker::reportTaintBug(StringRef Msg, ProgramStateRef State,
+                                   CheckerContext &C,
+                                   llvm::ArrayRef<SymbolRef> TaintedSyms,
+                                   AllocationFamily Family) const {
+
+  if (!ChecksEnabled[CK_TaintAllocChecker])
+    return;
----------------
NagyDonat wrote:

Move this check to `CheckTaintedness` -- there is no reason to calculate taint information if it won't be reported.

https://github.com/llvm/llvm-project/pull/92420