[clang][OpenMP] Implement isOpenMPCapturingDirective (#97090)

Check if the given directive can capture variables, and thus needs a
captured statement.

Simplify some code using this function.

Author: kparzysz

clang/include/clang/Basic/OpenMPKinds.h

@@ -376,6 +376,12 @@ bool checkFailClauseParameter(OpenMPClauseKind FailClauseParameter);
 /// \return true - if the above condition is met for this directive
 /// otherwise - false.
 bool isOpenMPExecutableDirective(OpenMPDirectiveKind DKind);
+
+/// Checks if the specified directive can capture variables.
+/// \param DKind Specified directive.
+/// \return true - if the above condition is met for this directive
+/// otherwise - false.
+bool isOpenMPCapturingDirective(OpenMPDirectiveKind DKind);
 }
 
 #endif

clang/lib/Basic/OpenMPKinds.cpp

@@ -709,10 +709,44 @@ bool clang::isOpenMPExecutableDirective(OpenMPDirectiveKind DKind) {
   return Cat == Category::Executable || Cat == Category::Subsidiary;
 }
 
+bool clang::isOpenMPCapturingDirective(OpenMPDirectiveKind DKind) {
+  if (isOpenMPExecutableDirective(DKind)) {
+    switch (DKind) {
+    case OMPD_atomic:
+    case OMPD_barrier:
+    case OMPD_cancel:
+    case OMPD_cancellation_point:
+    case OMPD_critical:
+    case OMPD_depobj:
+    case OMPD_error:
+    case OMPD_flush:
+    case OMPD_masked:
+    case OMPD_master:
+    case OMPD_section:
+    case OMPD_taskwait:
+    case OMPD_taskyield:
+      return false;
+    default:
+      return !isOpenMPLoopTransformationDirective(DKind);
+    }
+  }
+  // Non-executable directives.
+  switch (DKind) {
+  case OMPD_metadirective:
+  case OMPD_nothing:
+    return true;
+  default:
+    break;
+  }
+  return false;
+}
+
 void clang::getOpenMPCaptureRegions(
     SmallVectorImpl<OpenMPDirectiveKind> &CaptureRegions,
     OpenMPDirectiveKind DKind) {
   assert(unsigned(DKind) < llvm::omp::Directive_enumSize);
+  assert(isOpenMPCapturingDirective(DKind) && "Expecting capturing directive");
+
   switch (DKind) {
   case OMPD_metadirective:
     CaptureRegions.push_back(OMPD_metadirective);
@@ -799,48 +833,18 @@ void clang::getOpenMPCaptureRegions(
   case OMPD_for:
   case OMPD_for_simd:
   case OMPD_sections:
-  case OMPD_section:
   case OMPD_single:
-  case OMPD_master:
-  case OMPD_critical:
   case OMPD_taskgroup:
   case OMPD_distribute:
   case OMPD_ordered:
-  case OMPD_atomic:
   case OMPD_target_data:
   case OMPD_distribute_simd:
   case OMPD_scope:
   case OMPD_dispatch:
     CaptureRegions.push_back(OMPD_unknown);
     break;
-  case OMPD_tile:
-  case OMPD_unroll:
-    // loop transformations do not introduce captures.
-    break;
-  case OMPD_threadprivate:
-  case OMPD_allocate:
-  case OMPD_taskyield:
-  case OMPD_barrier:
-  case OMPD_error:
-  case OMPD_taskwait:
-  case OMPD_cancellation_point:
-  case OMPD_cancel:
-  case OMPD_flush:
-  case OMPD_depobj:
-  case OMPD_scan:
-  case OMPD_declare_reduction:
-  case OMPD_declare_mapper:
-  case OMPD_declare_simd:
-  case OMPD_declare_target:
-  case OMPD_end_declare_target:
-  case OMPD_requires:
-  case OMPD_declare_variant:
-  case OMPD_begin_declare_variant:
-  case OMPD_end_declare_variant:
-    llvm_unreachable("OpenMP Directive is not allowed");
-  case OMPD_unknown:
   default:
-    llvm_unreachable("Unknown OpenMP directive");
+    llvm_unreachable("Unhandled OpenMP directive");
   }
 }
 

clang/lib/Sema/SemaOpenMP.cpp

@@ -4862,11 +4862,7 @@ StmtResult SemaOpenMP::ActOnOpenMPRegionEnd(StmtResult S,
                                             ArrayRef<OMPClause *> Clauses) {
   handleDeclareVariantConstructTrait(DSAStack, DSAStack->getCurrentDirective(),
                                      /* ScopeEntry */ false);
-  if (DSAStack->getCurrentDirective() == OMPD_atomic ||
-      DSAStack->getCurrentDirective() == OMPD_critical ||
-      DSAStack->getCurrentDirective() == OMPD_section ||
-      DSAStack->getCurrentDirective() == OMPD_master ||
-      DSAStack->getCurrentDirective() == OMPD_masked)
+  if (!isOpenMPCapturingDirective(DSAStack->getCurrentDirective()))
     return S;
 
   bool ErrorFound = false;
@@ -4909,10 +4905,6 @@ StmtResult SemaOpenMP::ActOnOpenMPRegionEnd(StmtResult S,
         }
       }
       DSAStack->setForceVarCapturing(/*V=*/false);
-    } else if (isOpenMPLoopTransformationDirective(
-                   DSAStack->getCurrentDirective())) {
-      assert(CaptureRegions.empty() &&
-             "No captured regions in loop transformation directives.");
     } else if (CaptureRegions.size() > 1 ||
                CaptureRegions.back() != OMPD_unknown) {
       if (auto *C = OMPClauseWithPreInit::get(Clause))
@@ -6396,9 +6388,7 @@ StmtResult SemaOpenMP::ActOnOpenMPExecutableDirective(
     ClausesWithImplicit.append(Clauses.begin(), Clauses.end());
   }
   if (AStmt && !SemaRef.CurContext->isDependentContext() &&
-      Kind != OMPD_atomic && Kind != OMPD_critical && Kind != OMPD_section &&
-      Kind != OMPD_master && Kind != OMPD_masked &&
-      !isOpenMPLoopTransformationDirective(Kind)) {
+      isOpenMPCapturingDirective(Kind)) {
     assert(isa<CapturedStmt>(AStmt) && "Captured statement expected");
 
     // Check default data sharing attributes for referenced variables.