commit 64a9e3c530b0b034ff7de1277dd648ba5b95c6f6
author Jonas Hahnfeld <Hahnfeld@itc.rwth-aachen.de> Wed Feb 22 06:49:10 2017 +0000
committer Jonas Hahnfeld <Hahnfeld@itc.rwth-aachen.de> Wed Feb 22 06:49:10 2017 +0000
tree cf4a41a36f6e7790a24777fde8063f131c412a87
parent 9011aca5f4e8b3761626fd99cfb04dd260a40df8

[OpenMP] Generate better diagnostics for cancel and cancellation point

checkNestingOfRegions uses CancelRegion to determine whether cancel and
cancellation point are valid in the given nesting. This leads to unuseful
diagnostics if CancelRegion is invalid. The given test case has produced:
  region cannot be closely nested inside 'parallel' region

As a solution, introduce checkCancelRegion and call it first to get the
expected error:
  one of 'for', 'parallel', 'sections' or 'taskgroup' is expected

Differential Revision: https://reviews.llvm.org/D30135

llvm-svn: 295808

clang/lib/Sema/SemaOpenMP.cpp

diff --git a/clang/lib/Sema/SemaOpenMP.cpp b/clang/lib/Sema/SemaOpenMP.cpp
index 8711505..7d47997 100644
--- a/clang/lib/Sema/SemaOpenMP.cpp
+++ b/clang/lib/Sema/SemaOpenMP.cpp
@@ -1956,7 +1956,23 @@
   return SR;
 }
 
-static bool CheckNestingOfRegions(Sema &SemaRef, DSAStackTy *Stack,
+static bool checkCancelRegion(Sema &SemaRef, OpenMPDirectiveKind CurrentRegion,
+                              OpenMPDirectiveKind CancelRegion,
+                              SourceLocation StartLoc) {
+  // CancelRegion is only needed for cancel and cancellation_point.
+  if (CurrentRegion != OMPD_cancel && CurrentRegion != OMPD_cancellation_point)
+    return false;
+
+  if (CancelRegion == OMPD_parallel || CancelRegion == OMPD_for ||
+      CancelRegion == OMPD_sections || CancelRegion == OMPD_taskgroup)
+    return false;
+
+  SemaRef.Diag(StartLoc, diag::err_omp_wrong_cancel_region)
+      << getOpenMPDirectiveName(CancelRegion);
+  return true;
+}
+
+static bool checkNestingOfRegions(Sema &SemaRef, DSAStackTy *Stack,
                                   OpenMPDirectiveKind CurrentRegion,
                                   const DeclarationNameInfo &CurrentName,
                                   OpenMPDirectiveKind CancelRegion,
@@ -2256,7 +2272,9 @@
     OpenMPDirectiveKind CancelRegion, ArrayRef<OMPClause *> Clauses,
     Stmt *AStmt, SourceLocation StartLoc, SourceLocation EndLoc) {
   StmtResult Res = StmtError();
-  if (CheckNestingOfRegions(*this, DSAStack, Kind, DirName, CancelRegion,
+  // First check CancelRegion which is then used in checkNestingOfRegions.
+  if (checkCancelRegion(*this, Kind, CancelRegion, StartLoc) ||
+      checkNestingOfRegions(*this, DSAStack, Kind, DirName, CancelRegion,
                             StartLoc))
     return StmtError();
 
@@ -5860,12 +5878,6 @@
 Sema::ActOnOpenMPCancellationPointDirective(SourceLocation StartLoc,
                                             SourceLocation EndLoc,
                                             OpenMPDirectiveKind CancelRegion) {
-  if (CancelRegion != OMPD_parallel && CancelRegion != OMPD_for &&
-      CancelRegion != OMPD_sections && CancelRegion != OMPD_taskgroup) {
-    Diag(StartLoc, diag::err_omp_wrong_cancel_region)
-        << getOpenMPDirectiveName(CancelRegion);
-    return StmtError();
-  }
   if (DSAStack->isParentNowaitRegion()) {
     Diag(StartLoc, diag::err_omp_parent_cancel_region_nowait) << 0;
     return StmtError();
@@ -5882,12 +5894,6 @@
                                             SourceLocation StartLoc,
                                             SourceLocation EndLoc,
                                             OpenMPDirectiveKind CancelRegion) {
-  if (CancelRegion != OMPD_parallel && CancelRegion != OMPD_for &&
-      CancelRegion != OMPD_sections && CancelRegion != OMPD_taskgroup) {
-    Diag(StartLoc, diag::err_omp_wrong_cancel_region)
-        << getOpenMPDirectiveName(CancelRegion);
-    return StmtError();
-  }
   if (DSAStack->isParentNowaitRegion()) {
     Diag(StartLoc, diag::err_omp_parent_cancel_region_nowait) << 1;
     return StmtError();