[flang-commits] [flang] [FLANG][OMP] Add error message for invalid dependence type in taskwait construct (#219234). (PR #220837)

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https://github.com/laoshd created https://github.com/llvm/llvm-project/pull/220837

This PR is to fix #219234.

>From 9b342c5102a628f551ab2acc2314cea0ccc08558 Mon Sep 17 00:00:00 2001
From: Shandong Lao <shandong.lao at hpe.com>
Date: Thu, 3 Sep 2026 02:59:54 -0500
Subject: [PATCH] [FLANG][OMP] #219234: Add error message for invalid
 dependence type in taskwait construct.

---
 flang/lib/Semantics/check-omp-structure.cpp | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/flang/lib/Semantics/check-omp-structure.cpp b/flang/lib/Semantics/check-omp-structure.cpp
index 274efa64d03d0..762c9bf8a9be7 100644
--- a/flang/lib/Semantics/check-omp-structure.cpp
+++ b/flang/lib/Semantics/check-omp-structure.cpp
@@ -5116,6 +5116,14 @@ void OmpStructureChecker::Enter(const parser::OmpClause::Depend &x) {
       context_.Say(GetContext().clauseSource,
           "The SINK and SOURCE dependence types can only be used with the ORDERED directive, used here in the %s construct"_err_en_US,
           parser::omp::GetUpperName(dir, version));
+    } else if (dir == llvm::omp::OMPD_taskwait &&
+        taskDep->GetTaskDepType() ==
+            parser::OmpTaskDependenceType::Value::Mutexinoutset) {
+      // A depend clause on a taskwait construct must not have
+      // mutexinoutset as dependence-type.
+      context_.Say(GetContext().clauseSource,
+          "A DEPEND clause on a TASKWAIT construct must not have %s as dependence type"_err_en_US,
+          "MUTEXINOUTSET");
     }
   }
   if (taskDep) {