[flang-commits] [flang] [flang][OpenMP] Improve diagnosing invalid operators in DECLARE_REDUCTION (PR #232353)

[via flang-commits]

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@@ -771,8 +771,26 @@ void OmpStructureChecker::Enter(const parser::OmpMetadirectiveDirective &x) {
   EnterDirectiveNest(MetadirectiveNest);
 }
 
-void OmpStructureChecker::Leave(const parser::OmpMetadirectiveDirective &) {
-  ExitDirectiveNest(MetadirectiveNest);
+void OmpStructureChecker::Leave(const parser::OmpMetadirectiveDirective &x) {
+  // Perform semantic checks on declarative variants on this METADIRECTIVE.
+  if (!partStack_.empty() && partStack_.back() == PartKind::SpecificationPart) {
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MattPD wrote:

Flang now rejects the explicit AT(COMPILATION) case, but it still accepts the same `/` declaration with `otherwise(error)` under `-fsyntax-only`. Is it possible to also diagnose `/` in the implicit compilation-time form? Flang built from [the PR's merge base](https://github.com/llvm/llvm-project/commit/ccda5d7abf91e00b91c743ed1e6a1cd200b42997) rejects it.

https://github.com/llvm/llvm-project/pull/232353