[BPF] handle external global properly

Previous commit 6bc58e6d3dbd ("[BPF] do not generate unused local/global types")
tried to exclude global variable from type generation. The condition is:
     if (Global.hasExternalLinkage())
       continue;
This is not right. It also excluded initialized globals.

The correct condition (from AssemblyWriter::printGlobal()) is:
  if (!GV->hasInitializer() && GV->hasExternalLinkage())
    Out << "external ";

Let us do the same in BTF type generation. Also added a test for it.

Signed-off-by: Yonghong Song <yhs@fb.com>
llvm-svn: 356279

1 files changed, 1 insertions, 1 deletions

diff --git a/llvm/lib/Target/BPF/BTFDebug.cpp b/llvm/lib/Target/BPF/BTFDebug.cpp
index 5d1d96fa4cd..d00bc015835 100644
--- a/llvm/lib/Target/BPF/BTFDebug.cpp
+++ b/llvm/lib/Target/BPF/BTFDebug.cpp
@@ -751,7 +751,7 @@ void BTFDebug::endModule() {
   const Module *M = MMI->getModule();
   for (const GlobalVariable &Global : M->globals()) {
     // Ignore external globals for now.
-    if (Global.hasExternalLinkage())
+    if (!Global.hasInitializer() && Global.hasExternalLinkage())
       continue;
 
     SmallVector<DIGlobalVariableExpression *, 1> GVs;