[clang][OpenMP] OpenMP 6.0 updates to restrictions with order/concurrent (#125621)

From OpenMP 6.0 features list
- OpenMP directives in concurrent loop regions
- atomics constructs on concurrent loop regions
- Lift nesting restriction on concurrent loop

Testing
- Updated test/OpenMP/for_order_messages.cpp
- check-all

Author: ddpagan

clang/include/clang/Basic/OpenMPKinds.h

@@ -399,6 +399,14 @@ bool isOpenMPInformationalDirective(OpenMPDirectiveKind DKind);
 /// \return true - if the above condition is met for this directive
 /// otherwise - false.
 bool isOpenMPCapturingDirective(OpenMPDirectiveKind DKind);
+
+/// Checks if the specified directive is an order concurrent nestable
+/// directive that can be nested within region corresponding to construct
+/// on which order clause was specified with concurrent as ordering argument.
+/// \param DKind Specified directive.
+/// \return true - if the above condition is met for this directive
+/// otherwise - false.
+bool isOpenMPOrderConcurrentNestableDirective(OpenMPDirectiveKind DKind);
 }
 
 template <>

clang/lib/Basic/OpenMPKinds.cpp

@@ -765,6 +765,12 @@ bool clang::isOpenMPCapturingDirective(OpenMPDirectiveKind DKind) {
   return false;
 }
 
+bool clang::isOpenMPOrderConcurrentNestableDirective(
+    OpenMPDirectiveKind DKind) {
+  return DKind == OMPD_atomic || DKind == OMPD_loop || DKind == OMPD_simd ||
+         DKind == OMPD_parallel || isOpenMPLoopTransformationDirective(DKind);
+}
+
 void clang::getOpenMPCaptureRegions(
     SmallVectorImpl<OpenMPDirectiveKind> &CaptureRegions,
     OpenMPDirectiveKind DKind) {

clang/lib/Sema/SemaOpenMP.cpp

@@ -4788,13 +4788,26 @@ static bool checkNestingOfRegions(Sema &SemaRef, const DSAStackTy *Stack,
       getLeafOrCompositeConstructs(ParentRegion, LeafOrComposite);
   OpenMPDirectiveKind EnclosingConstruct = ParentLOC.back();
 
-  if (SemaRef.LangOpts.OpenMP >= 51 && Stack->isParentOrderConcurrent() &&
-      CurrentRegion != OMPD_simd && CurrentRegion != OMPD_loop &&
-      CurrentRegion != OMPD_parallel &&
-      !isOpenMPCombinedParallelADirective(CurrentRegion)) {
-    SemaRef.Diag(StartLoc, diag::err_omp_prohibited_region_order)
-        << getOpenMPDirectiveName(CurrentRegion);
-    return true;
+  if (Stack->isParentOrderConcurrent()) {
+    bool InvalidOrderNesting = false;
+    if ((SemaRef.LangOpts.OpenMP == 51 || SemaRef.LangOpts.OpenMP == 52) &&
+        CurrentRegion != OMPD_simd && CurrentRegion != OMPD_loop &&
+        CurrentRegion != OMPD_parallel &&
+        !isOpenMPCombinedParallelADirective(CurrentRegion)) {
+      InvalidOrderNesting = true;
+    } else if (SemaRef.LangOpts.OpenMP >= 60 &&
+               !isOpenMPOrderConcurrentNestableDirective(CurrentRegion)) {
+      // OpenMP 6.0 [12.3 order Clause, Restrictions]
+      // Only regions that correspond to order-concurrent-nestable constructs
+      // or order-concurrent-nestable routines may be strictly nested regions
+      // of regions that correspond to constructs on which the order clause is
+      // specified with concurrent as the ordering argument.
+      InvalidOrderNesting = true;
+    }
+    if (InvalidOrderNesting) {
+      SemaRef.Diag(StartLoc, diag::err_omp_prohibited_region_order)
+          << getOpenMPDirectiveName(CurrentRegion);
+    }
   }
   if (isOpenMPSimdDirective(ParentRegion) &&
       ((SemaRef.LangOpts.OpenMP <= 45 && CurrentRegion != OMPD_ordered) ||
@@ -7114,7 +7127,8 @@ ExprResult SemaOpenMP::ActOnOpenMPCall(ExprResult Call, Scope *Scope,
   if (!CalleeFnDecl)
     return Call;
 
-  if (getLangOpts().OpenMP >= 51 && CalleeFnDecl->getIdentifier() &&
+  if (getLangOpts().OpenMP >= 51 && getLangOpts().OpenMP < 60 &&
+      CalleeFnDecl->getIdentifier() &&
       CalleeFnDecl->getName().starts_with_insensitive("omp_")) {
     // checking for any calls inside an Order region
     if (Scope && Scope->isOpenMPOrderClauseScope())

clang/test/OpenMP/for_order_messages.cpp

@@ -1,8 +1,12 @@
 // RUN: %clang_cc1 -fsyntax-only -fopenmp -fopenmp-version=50 -triple x86_64-unknown-unknown -verify=expected,omp50 %s -Wuninitialized
-// RUN: %clang_cc1 -fsyntax-only -fopenmp -triple x86_64-unknown-unknown -verify=expected,omp51 %s -Wuninitialized
+// RUN: %clang_cc1 -fsyntax-only -fopenmp -fopenmp-version=51 -triple x86_64-unknown-unknown -verify=expected,omp51 %s -Wuninitialized
+// RUN: %clang_cc1 -fsyntax-only -fopenmp -fopenmp-version=52 -triple x86_64-unknown-unknown -verify=expected,omp51 %s -Wuninitialized
+// RUN: %clang_cc1 -fsyntax-only -fopenmp -fopenmp-version=60 -triple x86_64-unknown-unknown -verify=expected,omp60 %s -Wuninitialized
 
 // RUN: %clang_cc1 -fsyntax-only -fopenmp-simd -fopenmp-version=50 -triple x86_64-unknown-unknown -verify=expected,omp50 %s -Wuninitialized
-// RUN: %clang_cc1 -fsyntax-only -fopenmp-simd -triple x86_64-unknown-unknown -verify=expected,omp51 %s -Wuninitialized
+// RUN: %clang_cc1 -fsyntax-only -fopenmp-simd -fopenmp-version=51 -triple x86_64-unknown-unknown -verify=expected,omp51 %s -Wuninitialized
+// RUN: %clang_cc1 -fsyntax-only -fopenmp-simd -fopenmp-version=52 -triple x86_64-unknown-unknown -verify=expected,omp51 %s -Wuninitialized
+// RUN: %clang_cc1 -fsyntax-only -fopenmp-simd -fopenmp-version=60 -triple x86_64-unknown-unknown -verify=expected,omp60 %s -Wuninitialized
 
 extern int omp_get_num_threads  (void);
 
@@ -35,13 +39,61 @@ int main(int argc, char **argv) {
 
 #pragma omp parallel for order(reproducible: concurrent) // omp50-error {{expected 'concurrent' in OpenMP clause 'order'}}
   for (int i = 0; i < 10; ++i) {
-#pragma omp target //omp51-error {{construct 'target' not allowed in a region associated with a directive with 'order' clause}}
+#pragma omp target //omp51-error {{construct 'target' not allowed in a region associated with a directive with 'order' clause}} omp60-error {{construct 'target' not allowed in a region associated with a directive with 'order' clause}}
       A++;
   }
 
 #pragma omp parallel for order(unconstrained: concurrent) // omp50-error {{expected 'concurrent' in OpenMP clause 'order'}}
   for (int i = 0; i < 10; ++i) {
-#pragma omp target //omp51-error {{construct 'target' not allowed in a region associated with a directive with 'order' clause}}
+#pragma omp target //omp51-error {{construct 'target' not allowed in a region associated with a directive with 'order' clause}} omp60-error {{construct 'target' not allowed in a region associated with a directive with 'order' clause}}
       A++;
   }
+
+#pragma omp loop bind(parallel) order(concurrent)
+  for (int i = 0; i < 10; ++i) {
+#pragma omp parallel for //omp60-error {{construct 'parallel for' not allowed in a region associated with a directive with 'order' clause}}
+    for (int j = 0; j < 10; ++j) {
+      A += j;
+    }
+  }
+
+#pragma omp distribute order(concurrent)
+  for (int i = 0; i < 10; ++i) {
+#pragma omp parallel for simd //omp60-error {{construct 'parallel for simd' not allowed in a region associated with a directive with 'order' clause}}
+    for (int j = 0; j < 10; ++j) {
+      A += j;
+    }
+  }
+
+#pragma omp for order(concurrent)
+  for (int i = 0; i < 10; ++i) {
+#pragma omp parallel master //omp60-error {{construct 'parallel master' not allowed in a region associated with a directive with 'order' clause}}
+    for (int j = 0; j < 10; ++j) {
+      A += j;
+    }
+  }
+
+#pragma omp for order(concurrent)
+  for (int i = 0; i < 10; ++i) {
+#pragma omp parallel master taskloop //omp60-error {{construct 'parallel master taskloop' not allowed in a region associated with a directive with 'order' clause}}
+    for (int j = 0; j < 10; ++j) {
+      A += j;
+    }
+  }
+
+#pragma omp for order(concurrent)
+  for (int i = 0; i < 10; ++i) {
+#pragma omp parallel master taskloop simd //omp60-error {{construct 'parallel master taskloop simd' not allowed in a region associated with a directive with 'order' clause}}
+    for (int j = 0; j < 10; ++j) {
+      A += j;
+    }
+  }
+
+#pragma omp for order(concurrent)
+  for (int i = 0; i < 10; ++i) {
+    #pragma omp parallel sections //omp60-error {{construct 'parallel sections' not allowed in a region associated with a directive with 'order' clause}}
+    {
+      A++;
+    }
+  }
 }