Enable assembly output of local commons for AIX

Summary:
This patch enable assembly output of local commons for AIX using .lcomm
directives. Adds a EmitXCOFFLocalCommonSymbol to MCStreamer so we can emit the
AIX version of .lcomm assembly directives which include a csect name. Handle the
case of BSS locals in PPCAIXAsmPrinter by using EmitXCOFFLocalCommonSymbol. Adds
a test for generating .lcomm on AIX Targets.

Reviewers: cebowleratibm, hubert.reinterpretcast, Xiangling_L, jasonliu, sfertile

Reviewed By: sfertile

Subscribers: wuzish, nemanjai, hiraditya, kbarton, MaskRay, jsji, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D64825

llvm-svn: 368306

1 files changed, 4 insertions, 0 deletions

diff --git a/llvm/lib/MC/MCStreamer.cpp b/llvm/lib/MC/MCStreamer.cpp
index 254eb2c..2e36fe7 100644
--- a/llvm/lib/MC/MCStreamer.cpp
+++ b/llvm/lib/MC/MCStreamer.cpp
@@ -1055,6 +1055,10 @@ void MCStreamer::EmitCOFFSymbolStorageClass(int StorageClass) {
 void MCStreamer::EmitCOFFSymbolType(int Type) {
   llvm_unreachable("this directive only supported on COFF targets");
 }
+void MCStreamer::EmitXCOFFLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size,
+                                            unsigned ByteAlign) {
+  llvm_unreachable("this directive only supported on XCOFF targets");
+}
 void MCStreamer::emitELFSize(MCSymbol *Symbol, const MCExpr *Value) {}
 void MCStreamer::emitELFSymverDirective(StringRef AliasName,
                                         const MCSymbol *Aliasee) {}