[clang] [alpha.webkit.UncountedLocalVarsChecker] Allow uncounted object references within trivial statements (PR #82229)

[Ryosuke Niwa via cfe-commits]

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@@ -189,18 +202,16 @@ class UncountedLocalVarsChecker
                 dyn_cast_or_null<VarDecl>(Ref->getFoundDecl())) {
           const auto *MaybeGuardianArgType =
               MaybeGuardian->getType().getTypePtr();
-          if (!MaybeGuardianArgType)
-            return;
-          const CXXRecordDecl *const MaybeGuardianArgCXXRecord =
-              MaybeGuardianArgType->getAsCXXRecordDecl();
-          if (!MaybeGuardianArgCXXRecord)
-            return;
-
-          if (MaybeGuardian->isLocalVarDecl() &&
-              (isRefCounted(MaybeGuardianArgCXXRecord) ||
-               isRefcountedStringsHack(MaybeGuardian)) &&
-              isGuardedScopeEmbeddedInGuardianScope(V, MaybeGuardian)) {
-            return;
+          if (MaybeGuardianArgType) {
+            const CXXRecordDecl *const MaybeGuardianArgCXXRecord =
+                MaybeGuardianArgType->getAsCXXRecordDecl();
+            if (MaybeGuardianArgCXXRecord) {
+              if (MaybeGuardian->isLocalVarDecl() &&
+                  (isRefCounted(MaybeGuardianArgCXXRecord) ||
+                   isRefcountedStringsHack(MaybeGuardian)) &&
+                  isGuardedScopeEmbeddedInGuardianScope(V, MaybeGuardian))
+                return;
+            }
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rniwa wrote:

So before this PR, those early exits took place when `MaybeGuardianArgType` was `nullptr` or if `MaybeGuardianArgType` wasn't a `CXXRecordDecl`. This PR changes so that we only return when all these conditions hold true or when it's a `ParmVarDecl`.

https://github.com/llvm/llvm-project/pull/82229