[Clang][OpenMP] throw compilation error instead of crash in Stmt::OMPScopeDirectiveClass case (#77535) (#84135)

Fix #77535, Change unstable assertion into compilation error, and add a
test for it.

2 files changed, 10 insertions, 1 deletions

diff --git a/clang/lib/CodeGen/CGStmt.cpp b/clang/lib/CodeGen/CGStmt.cpp
index 41ac511..39222c0 100644
--- a/clang/lib/CodeGen/CGStmt.cpp
+++ b/clang/lib/CodeGen/CGStmt.cpp
@@ -414,7 +414,8 @@ void CodeGenFunction::EmitStmt(const Stmt *S, ArrayRef<const Attr *> Attrs) {
     CGM.ErrorUnsupported(S, "OpenMP dispatch directive");
     break;
   case Stmt::OMPScopeDirectiveClass:
-    llvm_unreachable("scope not supported with FE outlining");
+    CGM.ErrorUnsupported(S, "scope with FE outlining");
+    break;
   case Stmt::OMPMaskedDirectiveClass:
     EmitOMPMaskedDirective(cast<OMPMaskedDirective>(*S));
     break;
diff --git a/clang/test/OpenMP/error_unsupport_feature.c b/clang/test/OpenMP/error_unsupport_feature.c
new file mode 100644
index 0000000..611a8b4
--- /dev/null
+++ b/clang/test/OpenMP/error_unsupport_feature.c
@@ -0,0 +1,8 @@
+// RUN: %clang_cc1 -emit-llvm -verify -fopenmp %s
+
+int main () {
+  int r = 0;
+#pragma omp scope reduction(+:r) // expected-error {{cannot compile this scope with FE outlining yet}}
+  r++;
+  return r;
+}