[OpenMP] Diagnose function name on the link clause

[kkwli0]

Summary

This patch is to add diagnose when a function name is specified on the link clause. According to the OpenMP spec, only the list items that exclude the function name are allowed on the link clause.

void foo() {}
#pragma omp declare target link(foo)

d2.c:2:33: error: function name is not allowed in 'link' clause
#pragma omp declare target link(foo)
                                ^
d2.c:1:6: note: 'foo' defined here
void foo() {}
     ^
1 error generated.

[ABataev]

lib/Sema/SemaOpenMP.cpp

12576 ↗

(On Diff #125983)

I would like to see this some in check functions, like checkDeclIsAllowedInOpenMPTarget rather than here

[kkwli0]

lib/Sema/SemaOpenMP.cpp

12576 ↗

(On Diff #125983)

Sure. I will move the check into checkDeclIsAllowedInOpenMPTarget.

[ABataev]

lib/Sema/SemaOpenMP.cpp

12671 ↗

(On Diff #126025)

You can get DeclarationNameInfo from the FunctionDecl:

FD->getNameInfo()

[kkwli0]

lib/Sema/SemaOpenMP.cpp

12671 ↗

(On Diff #126025)

This FD->getNameInfo() will only give the name info from the function definition. What we need here is the name info for 'foo' that appears on the pragma in order to give us

d2.c:2:33: error: function name is not allowed in 'link' clause
#pragma omp declare target link(foo)
                                ^

[ABataev]

lib/Sema/SemaOpenMP.cpp

12671 ↗

(On Diff #126025)

Then just pass SourceLocation

[kkwli0]

lib/Sema/SemaOpenMP.cpp

12671 ↗

(On Diff #126025)

Sure.

[ABataev]

LG

cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td

def err_omp_invalid_target_decl : Error<
   "%0 used in declare target directive is not a variable or a function name">;
 def err_omp_declare_target_multiple : Error<
   "%0 appears multiple times in clauses on the same declare target directive">;
 def err_omp_declare_target_to_and_link : Error<
   "%0 must not appear in both clauses 'to' and 'link'">;
 def warn_omp_not_in_target_context : Warning<
   "declaration is not declared in any declare target region">,
   InGroup<OpenMPTarget>;
+def err_omp_function_in_link_clause : Error<
+  "function name is not allowed in 'link' clause">;
 def err_omp_aligned_expected_array_or_ptr : Error<
   "argument of aligned clause should be array"
   "%select{ or pointer|, pointer, reference to array or reference to pointer}1"
   ", not %0">;
 def err_omp_aligned_twice : Error<
   "%select{a variable|a parameter|'this'}0 cannot appear in more than one aligned clause">;
 def err_omp_local_var_in_threadprivate_init : Error<
   "variable with local storage in initial value of threadprivate variable">;

cfe/trunk/include/clang/Sema/Sema.h

public:
   /// Called at the end of target region i.e. '#pragme omp end declare target'.
   void ActOnFinishOpenMPDeclareTargetDirective();
   /// Called on correct id-expression from the '#pragma omp declare target'.
   void ActOnOpenMPDeclareTargetName(Scope *CurScope, CXXScopeSpec &ScopeSpec,
                                     const DeclarationNameInfo &Id,
                                     OMPDeclareTargetDeclAttr::MapTypeTy MT,
                                     NamedDeclSetType &SameDirectiveDecls);
   /// Check declaration inside target region.
-  void checkDeclIsAllowedInOpenMPTarget(Expr *E, Decl *D);
+  void checkDeclIsAllowedInOpenMPTarget(Expr *E, Decl *D,
+                                        SourceLocation IdLoc = SourceLocation());
   /// Return true inside OpenMP declare target region.
   bool isInOpenMPDeclareTargetContext() const {
     return IsInOpenMPDeclareTargetContext;
   }
   /// Return true inside OpenMP target region.
   bool isInOpenMPTargetExecutionDirective() const;
   /// Return true if (un)supported features for the current target should be
   /// diagnosed if OpenMP (offloading) is enabled.

cfe/trunk/lib/Sema/SemaOpenMP.cpp

if (isa<VarDecl>(ND) || isa<FunctionDecl>(ND)) {
     if (!SameDirectiveDecls.insert(cast<NamedDecl>(ND->getCanonicalDecl())))
       Diag(Id.getLoc(), diag::err_omp_declare_target_multiple) << Id.getName();
 
     if (!ND->hasAttr<OMPDeclareTargetDeclAttr>()) {
       Attr *A = OMPDeclareTargetDeclAttr::CreateImplicit(Context, MT);
       ND->addAttr(A);
       if (ASTMutationListener *ML = Context.getASTMutationListener())
         ML->DeclarationMarkedOpenMPDeclareTarget(ND, A);
-      checkDeclIsAllowedInOpenMPTarget(nullptr, ND);
+      checkDeclIsAllowedInOpenMPTarget(nullptr, ND, Id.getLoc());
     } else if (ND->getAttr<OMPDeclareTargetDeclAttr>()->getMapType() != MT) {
       Diag(Id.getLoc(), diag::err_omp_declare_target_to_and_link)
           << Id.getName();
     }
   } else
     Diag(Id.getLoc(), diag::err_omp_invalid_target_decl) << Id.getName();
 }
 
static bool checkValueDeclInTarget(SourceLocation SL, SourceRange SR,
                                    ValueDecl *VD) {
   if (VD->hasAttr<OMPDeclareTargetDeclAttr>())
     return true;
   if (!CheckTypeMappable(SL, SR, SemaRef, Stack, VD->getType()))
     return false;
   return true;
 }
 
-void Sema::checkDeclIsAllowedInOpenMPTarget(Expr *E, Decl *D) {
+void Sema::checkDeclIsAllowedInOpenMPTarget(Expr *E, Decl *D,
+                                            SourceLocation IdLoc) {
   if (!D || D->isInvalidDecl())
     return;
   SourceRange SR = E ? E->getSourceRange() : D->getSourceRange();
   SourceLocation SL = E ? E->getLocStart() : D->getLocation();
   // 2.10.6: threadprivate variable cannot appear in a declare target directive.
   if (VarDecl *VD = dyn_cast<VarDecl>(D)) {
     if (DSAStack->isThreadPrivate(VD)) {
       Diag(SL, diag::err_omp_threadprivate_in_target);
if ((E || !VD->getType()->isIncompleteType()) &&
             Context, OMPDeclareTargetDeclAttr::MT_To);
         VD->addAttr(A);
         if (ASTMutationListener *ML = Context.getASTMutationListener())
           ML->DeclarationMarkedOpenMPDeclareTarget(VD, A);
       }
       return;
     }
   }
+  if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
+    if (FD->hasAttr<OMPDeclareTargetDeclAttr>() &&
+        (FD->getAttr<OMPDeclareTargetDeclAttr>()->getMapType() ==
+         OMPDeclareTargetDeclAttr::MT_Link)) {
+      assert(IdLoc.isValid() && "Source location is expected");
+      Diag(IdLoc, diag::err_omp_function_in_link_clause);
+      Diag(FD->getLocation(), diag::note_defined_here) << FD;
+      return;
+    }
+  }
   if (!E) {
     // Checking declaration inside declare target region.
     if (!D->hasAttr<OMPDeclareTargetDeclAttr>() &&
         (isa<VarDecl>(D) || isa<FunctionDecl>(D))) {
       Attr *A = OMPDeclareTargetDeclAttr::CreateImplicit(
           Context, OMPDeclareTargetDeclAttr::MT_To);
       D->addAttr(A);
       if (ASTMutationListener *ML = Context.getASTMutationListener())

cfe/trunk/test/OpenMP/declare_target_ast_print.cpp

 // CHECK: #pragma omp declare target
 // CHECK: int b3;
 // CHECK: #pragma omp end declare target
 // CHECK: #pragma omp declare target
 // CHECK: void f2()
 // CHECK: #pragma omp end declare target
 
 int c1, c2, c3;
-void f3() {
-}
-#pragma omp declare target link(c1) link(c2), link(c3, f3)
+#pragma omp declare target link(c1) link(c2), link(c3)
 // CHECK: #pragma omp declare target link
 // CHECK: int c1;
 // CHECK: #pragma omp end declare target
 // CHECK: #pragma omp declare target link
 // CHECK: int c2;
 // CHECK: #pragma omp end declare target
 // CHECK: #pragma omp declare target link
 // CHECK: int c3;
 // CHECK: #pragma omp end declare target
-// CHECK: #pragma omp declare target link
-// CHECK: void f3()
-// CHECK: #pragma omp end declare target
 
 struct SSSt {
 #pragma omp declare target
   static int a;
   int b;
 #pragma omp end declare target
 };
 

cfe/trunk/test/OpenMP/declare_target_messages.cpp

 #pragma omp declare target map(a) // expected-error {{unexpected 'map' clause, only 'to' or 'link' clauses expected}}
 
 #pragma omp declare target to(foo1) // expected-error {{use of undeclared identifier 'foo1'}}
 
 #pragma omp declare target link(foo2) // expected-error {{use of undeclared identifier 'foo2'}}
 
 void c(); // expected-warning {{declaration is not declared in any declare target region}}
 
+void func() {} // expected-note {{'func' defined here}}
+
+#pragma omp declare target link(func) // expected-error {{function name is not allowed in 'link' clause}}
+
 extern int b;
 
 struct NonT {
   int a;
 };
 
 typedef int sint;