Make clear in the release notes and inline comments that

this is a conservative fix and not a complete solution
to the no-return function analysis.

Author: snarang181

clang/docs/ReleaseNotes.rst

@@ -648,11 +648,12 @@ Improvements to Clang's diagnostics
   #GH69470, #GH59391, #GH58172, #GH46215, #GH45915, #GH45891, #GH44490,
   #GH36703, #GH32903, #GH23312, #GH69874.
 
-- Clang no longer warns about missing return statements (-Wreturn-type)
-  if the final statement of a non-void function is a `throw` expression
-  or a call to a function that is known to always throw. This avoids
-  false positives in code patterns where control flow is intentionally
-  terminated via exceptions.
+- Clang now avoids issuing `-Wreturn-type` warnings in some cases where
+  the final statement of a non-void function is a `throw` expression, or
+  a call to a function that is trivially known to always throw (i.e., its
+  body consists solely of a `throw` statement). This avoids certain
+  false positives in exception-heavy code, though only simple patterns
+  are currently recognized.
 
 
 Improvements to Clang's time-trace

clang/lib/Sema/AnalysisBasedWarnings.cpp

@@ -624,6 +624,11 @@ struct CheckFallThroughDiagnostics {
   }
 };
 
+// FIXME: This is a shallow best-effort check. Currently, we only handle
+// cases where the function body consists of a single `throw` expression,
+// possibly wrapped in an `ExprWithCleanups`. We do not perform general
+// control-flow analysis or handle more complex throwing patterns.
+// Consider expanding this to handle more cases in the future.
 bool isKnownToAlwaysThrow(const FunctionDecl *FD) {
   if (!FD->hasBody())
     return false;
@@ -704,7 +709,7 @@ static void CheckFallThroughForBody(Sema &S, const Decl *D, const Stmt *Body,
     } else if (!ReturnsVoid && CD.diag_FallThrough_ReturnsNonVoid) {
       // If the final statement is a call to an always-throwing function,
       // don't warn about the fall-through.
-      if (const auto *FD = dyn_cast<FunctionDecl>(D)) {
+      if (const auto *FD = D->getAsFunction()) {
         if (const auto *CS = dyn_cast<CompoundStmt>(Body);
             CS && !CS->body_empty()) {
           const Stmt *LastStmt = CS->body_back();