[AIX] Emit TOC entries for ASM printing

Summary:
Emit the correct .toc psuedo op when we change to the TOC and emit
TC entries. Make sure TOC psuedos get the right symbols via overriding
getMCSymbolForTOCPseudoMO on AIX. Add a test for TOC assembly writing
and update tests to include TOC entries.

Also make sure external globals have a csect set and handle external function descriptor (originally authored by Jason Liu) so we can emit TOC entries for them.

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

Reviewed By: jasonliu

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

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D70461

1 files changed, 4 insertions, 0 deletions

diff --git a/llvm/lib/BinaryFormat/XCOFF.cpp b/llvm/lib/BinaryFormat/XCOFF.cpp
index 001b8077cd3..29ccbaea358 100644
--- a/llvm/lib/BinaryFormat/XCOFF.cpp
+++ b/llvm/lib/BinaryFormat/XCOFF.cpp
@@ -24,6 +24,10 @@ StringRef XCOFF::getMappingClassString(XCOFF::StorageMappingClass SMC) {
     return "BS";
   case XCOFF::XMC_RO:
     return "RO";
+  case XCOFF::XMC_UA:
+    return "UA";
+  case XCOFF::XMC_TC:
+    return "TC";
   default:
     report_fatal_error("Unhandled storage-mapping class.");
   }