[flang-commits] [flang] [llvm] [Flang] [OpenMP] Add semantic checks for detach clause in task (PR #119172)

[Krzysztof Parzyszek via flang-commits]

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@@ -2739,6 +2739,59 @@ void OmpStructureChecker::Leave(const parser::OmpClauseList &) {
         llvm::omp::Clause::OMPC_copyprivate, {llvm::omp::Clause::OMPC_nowait});
   }
 
+  if (GetContext().directive == llvm::omp::Directive::OMPD_task) {
+    if (auto *d_clause{FindClause(llvm::omp::Clause::OMPC_detach)}) {
+      // OpenMP 5.0: Task construct restrictions
+      CheckNotAllowedIfClause(
+          llvm::omp::Clause::OMPC_detach, {llvm::omp::Clause::OMPC_mergeable});
+
+      // OpenMP 5.2: Task construct restrictions
+      if (FindClause(llvm::omp::Clause::OMPC_final)) {
+        context_.Say(GetContext().clauseSource,
+            "If a DETACH clause appears on a directive, then the encountering task must not be a FINAL task"_err_en_US);
+      }
+
+      const auto &detachClause{
+          std::get<parser::OmpClause::Detach>(d_clause->u)};
+      if (const auto *name{parser::Unwrap<parser::Name>(detachClause.v.v)}) {
+        if (name->symbol) {
+          std::string eventHandleSymName{name->ToString()};
+          auto checkVarAppearsInDataEnvClause = [&](const parser::OmpObjectList
+                                                        &objs,
+                                                    std::string clause) {
+            for (const auto &obj : objs.v) {
+              if (const parser::Name *objName{
+                      parser::Unwrap<parser::Name>(obj)}) {
+                if (objName->ToString() == eventHandleSymName) {
+                  context_.Say(GetContext().clauseSource,
+                      "A variable: `%s` that appears in a DETACH clause cannot appear on %s clause on the same construct"_err_en_US,
+                      eventHandleSymName, clause);
+                }
+              }
+            }
+          };
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kparzysz wrote:

Please compare symbols, not names.  You can compare the results of `&symbol->GetUltimate()` to be accurate.

https://github.com/llvm/llvm-project/pull/119172