default clause replaced by otherwise clause for metadirective in OpenMP 5.2 (#125648)

This PR replaces the `default` clause with the `otherwise` clause for
the `metadirective` in OpenMP. The `otherwise` clause serves as a
fallback condition when no directive from the `when` clauses is
selected. In the `when` clause, context selectors define traits
evaluated to determine the directive to be applied.

1 files changed, 20 insertions, 0 deletions

diff --git a/clang/lib/Parse/ParseOpenMP.cpp b/clang/lib/Parse/ParseOpenMP.cpp
index 42e6aac..3b86847 100644
--- a/clang/lib/Parse/ParseOpenMP.cpp
+++ b/clang/lib/Parse/ParseOpenMP.cpp
@@ -2759,6 +2759,19 @@ StmtResult Parser::ParseOpenMPDeclarativeOrExecutableDirective(
       OpenMPClauseKind CKind = Tok.isAnnotation()
                                    ? OMPC_unknown
                                    : getOpenMPClauseKind(PP.getSpelling(Tok));
+      // Check if the clause is unrecognized.
+      if (getLangOpts().OpenMP < 52 &&
+          (CKind == OMPC_unknown || CKind == OMPC_otherwise)) {
+        Diag(Tok, diag::err_omp_unknown_clause)
+            << PP.getSpelling(Tok) << "metadirective";
+      }
+      if (getLangOpts().OpenMP >= 52 && CKind == OMPC_unknown) {
+        Diag(Tok, diag::err_omp_unknown_clause)
+            << PP.getSpelling(Tok) << "metadirective";
+      }
+      if (CKind == OMPC_default && getLangOpts().OpenMP >= 52) {
+        Diag(Tok, diag::warn_omp_default_deprecated);
+      }
       SourceLocation Loc = ConsumeToken();
 
       // Parse '('.
@@ -2785,6 +2798,13 @@ StmtResult Parser::ParseOpenMPDeclarativeOrExecutableDirective(
           return Directive;
         }
       }
+      if (CKind == OMPC_otherwise) {
+        // Check for 'otherwise' keyword.
+        if (Tok.is(tok::identifier) &&
+            Tok.getIdentifierInfo()->getName() == "otherwise") {
+          ConsumeToken(); // Consume 'otherwise'
+        }
+      }
       // Skip Directive for now. We will parse directive in the second iteration
       int paren = 0;
       while (Tok.isNot(tok::r_paren) || paren != 0) {