[OpenMP] Handle non-function context before checking for diagnostic emission

[pmrao]

Summary

Ensure that we are in a function declaration context before checking
the diagnostic emission status, to avoid dereferencing a NULL function
declaration.

[erichkeane]

clang/lib/Sema/SemaOpenMP.cpp

1946

Tabs here instead of spaces.

I think this is the right fix for SYCL, but @bader should double-check that he's ok with this or OMP.

[pmrao]

clang/lib/Sema/SemaOpenMP.cpp

1946

Tabs here instead of spaces.

Are you suggesting that I change the spaces to tabs instead?

[erichkeane]

clang/lib/Sema/SemaOpenMP.cpp

1946

The reverse. Change the tabs you have at the beginning of the line to spaces. I believe that is what the double-arrow character in Phab represents (a tab).

[pmrao]

clang/lib/Sema/SemaOpenMP.cpp

1946

Oh! I misunderstood then. I thought phab was indicating that there are no changes in the line, except new indentation.

I didn't use tabs in my source file. I don't see it in the character set. Perhaps something introduced it during the upload. I will check.

[erichkeane]

clang/lib/Sema/SemaOpenMP.cpp

1946

Oh, it looks like you're right, that must be a new feature of Phab that looks shockingly like an old one :) I don't see tabs in the downloaded diff file, so consider that comment 'done'.

[jdoerfert]

looks reasonable to me

[bader]

LGTM.

clang/lib/Sema/SemaDecl.cpp

 }
 
 Decl *Sema::getObjCDeclContext() const {
   return (dyn_cast_or_null<ObjCContainerDecl>(CurContext));
 }
 
 Sema::FunctionEmissionStatus Sema::getEmissionStatus(FunctionDecl *FD,
                                                      bool Final) {
+  assert(FD && "Expected non-null FunctionDecl");
+
   // SYCL functions can be template, so we check if they have appropriate
   // attribute prior to checking if it is a template.
   if (LangOpts.SYCLIsDevice && FD->hasAttr<SYCLKernelAttr>())
     return FunctionEmissionStatus::Emitted;
 
   // Templates are emitted when they're instantiated.
   if (FD->isDependentContext())
     return FunctionEmissionStatus::TemplateDiscarded;

clang/lib/Sema/SemaOpenMP.cpp

Sema::SemaDiagnosticBuilder Sema::diagIfOpenMPDeviceCode(SourceLocation Loc,
   return SemaDiagnosticBuilder(Kind, Loc, DiagID, FD, *this);
 }
 
 Sema::SemaDiagnosticBuilder Sema::diagIfOpenMPHostCode(SourceLocation Loc,
                                                        unsigned DiagID,
                                                        FunctionDecl *FD) {
   assert(LangOpts.OpenMP && !LangOpts.OpenMPIsDevice &&
          "Expected OpenMP host compilation.");
-  FunctionEmissionStatus FES = getEmissionStatus(FD);
+
   SemaDiagnosticBuilder::Kind Kind = SemaDiagnosticBuilder::K_Nop;
+  if (FD) {
+    FunctionEmissionStatus FES = getEmissionStatus(FD);
     switch (FES) {
     case FunctionEmissionStatus::Emitted:
       Kind = SemaDiagnosticBuilder::K_Immediate;
       break;
     case FunctionEmissionStatus::Unknown:
       Kind = SemaDiagnosticBuilder::K_Deferred;
       break;
     case FunctionEmissionStatus::TemplateDiscarded:
     case FunctionEmissionStatus::OMPDiscarded:
     case FunctionEmissionStatus::CUDADiscarded:
       Kind = SemaDiagnosticBuilder::K_Nop;
       break;
     }
+  }
 
   return SemaDiagnosticBuilder(Kind, Loc, DiagID, FD, *this);
 }
 
 static OpenMPDefaultmapClauseKind
 getVariableCategoryFromDecl(const LangOptions &LO, const ValueDecl *VD) {
   if (LO.OpenMP <= 45) {
     if (VD->getType().getNonReferenceType()->isScalarType())

clang/test/OpenMP/simd_null_pointer_access.cpp

+// RUN: %clang_cc1 -fopenmp-simd -fsycl -fsycl-is-device -triple spir64 -verify -fsyntax-only %s
+
+// Test that in the presence of SYCL options, that null function
+// declarations are accounted for when checking to emit diagnostics.
+
+// expected-no-diagnostics
+
+__thread void *x;