r341570 - [OPENMP] Fix PR38823: Do not emit vtable if it is not used in target

[Alexey Bataev via cfe-commits]

Author: abataev
Date: Thu Sep  6 10:56:28 2018
New Revision: 341570

URL: http://llvm.org/viewvc/llvm-project?rev=341570&view=rev
Log:
[OPENMP] Fix PR38823: Do not emit vtable if it is not used in target
context.

If the explicit template instantiation definition defined outside of the
target context, its vtable should not be marked as used. This is true
for other situations where the compiler want to emit vtables
unconditionally.

Modified:
    cfe/trunk/lib/Sema/SemaDeclCXX.cpp
    cfe/trunk/test/OpenMP/declare_target_codegen.cpp

Modified: cfe/trunk/lib/Sema/SemaDeclCXX.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaDeclCXX.cpp?rev=341570&r1=341569&r2=341570&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaDeclCXX.cpp (original)
+++ cfe/trunk/lib/Sema/SemaDeclCXX.cpp Thu Sep  6 10:56:28 2018
@@ -14903,6 +14903,11 @@ void Sema::MarkVTableUsed(SourceLocation
   if (!Class->isDynamicClass() || Class->isDependentContext() ||
       CurContext->isDependentContext() || isUnevaluatedContext())
     return;
+  // Do not mark as used if compiling for the device outside of the target
+  // region.
+  if (LangOpts.OpenMP && LangOpts.OpenMPIsDevice &&
+      !isInOpenMPDeclareTargetContext() && !getCurFunctionDecl())
+    return;
 
   // Try to insert this class into the map.
   LoadExternalVTableUses();

Modified: cfe/trunk/test/OpenMP/declare_target_codegen.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/OpenMP/declare_target_codegen.cpp?rev=341570&r1=341569&r2=341570&view=diff
==============================================================================
--- cfe/trunk/test/OpenMP/declare_target_codegen.cpp (original)
+++ cfe/trunk/test/OpenMP/declare_target_codegen.cpp Thu Sep  6 10:56:28 2018
@@ -12,7 +12,8 @@
 
 // SIMD-ONLY-NOT: {{__kmpc|__tgt}}
 
-// CHECK-NOT: define {{.*}}{{baz1|baz4|maini1}}
+// CHECK-NOT: define {{.*}}{{baz1|baz4|maini1|Base}}
+// CHECK-DAG: Bake
 // CHECK-NOT: @{{hhh|ggg|fff|eee}} =
 // CHECK-DAG: @aaa = external global i32,
 // CHECK-DAG: @bbb = global i32 0,
@@ -140,9 +141,25 @@ int baz5() {
   return a;
 }
 
+template <typename T>
+struct Base {
+  virtual ~Base() {}
+};
+
+template class Base<int>;
+
+template <typename T>
+struct Bake {
+  virtual ~Bake() {}
+};
+
+#pragma omp declare target
+template class Bake<int>;
+#pragma omp end declare target
+
 // CHECK-DAG: declare extern_weak signext i32 @__create()
 
-// CHECK-NOT: define {{.*}}{{baz1|baz4|maini1}}
+// CHECK-NOT: define {{.*}}{{baz1|baz4|maini1|Base}}
 
 // CHECK-DAG: !{i32 1, !"aaa", i32 0, i32 {{[0-9]+}}}
 // CHECK-DAG: !{i32 1, !"ccc", i32 0, i32 {{[0-9]+}}}