[OpenMP] Diagnose missing cases of statements between target and teams directives

[• davidsh]

Summary

Clang fails to diagnose cases such as
#pragma omp target

while(0) {
  #pragma omp teams
  {}
}

[sfantao]

Hi David,

This fix looks good but you have to add a regression test for it.

Thanks,
Samuel

[kkwli0]

The changes look fine to me. Thanks.

[sfantao]

Thanks David,

Let's wait for Alexey to see if he has any concerns related to this patch.

Thanks again,
Samuel

[ABataev]

LG with a small nit

lib/Sema/SemaOpenMP.cpp

6384–6386

I'd prefer something like this:

auto *OED = dyn_cast<OMPExecutableDirective>(S);
OMPTeamsFound = OED && isOpenMPTeamsDirective(OED->getDirectiveKind());

[• davidsh]

Address a comment.

[ABataev]

LG

[kkwli0]

At revision: 273908

lib/Sema/SemaOpenMP.cpp

if (auto *CS = dyn_cast<CompoundStmt>(S)) {
         if (!OED || !isOpenMPTeamsDirective(OED->getDirectiveKind())) {
           OMPTeamsFound = false;
           break;
         }
         ++I;
       }
       assert(I != CS->body_end() && "Not found statement");
       S = *I;
+    } else {
+      auto *OED = dyn_cast<OMPExecutableDirective>(S);
+      OMPTeamsFound = OED && isOpenMPTeamsDirective(OED->getDirectiveKind());
     }
     if (!OMPTeamsFound) {
       Diag(StartLoc, diag::err_omp_target_contains_not_only_teams);
       Diag(DSAStack->getInnerTeamsRegionLoc(),
            diag::note_omp_nested_teams_construct_here);
       Diag(S->getLocStart(), diag::note_omp_nested_statement_here)
           << isa<OMPExecutableDirective>(S);
       return StmtError();
     }

test/OpenMP/nesting_of_regions.cpp

#pragma omp teams
     ++a;
   }
 #pragma omp target // expected-error {{target construct with nested teams region contains statements outside of the teams construct}}
   {
     ++a;           // expected-note {{statement outside teams construct here}}
 #pragma omp teams  // expected-note {{nested teams construct here}}
     ++a;
   }
+#pragma omp target // expected-error {{target construct with nested teams region contains statements outside of the teams construct}}
+  {
+    while (0)      // expected-note {{statement outside teams construct here}}
+#pragma omp teams  // expected-note {{nested teams construct here}}
+    ++a;
+  }
 #pragma omp target
   {
 #pragma omp taskloop
   for (int i = 0; i < 10; ++i)
     ++a;
   }
 #pragma omp target
   {