[AIX][llvm-ar] Use the Correct Kind for Bitcode File Inputs

[qiongsiwu1]

Summary

On AIX, when the input files are LLVM bitcode files, llvm-ar should set the archive kind to K_AIXBIG as well, instead of leaving it to the default K_GNU.

[qiongsiwu1]

Fix a typo in the test case comment.

[qiongsiwu1]

Clean up the test a bit.

[daltenty]

LGTM with minor nit. Thanks!

llvm/test/tools/llvm-ar/aix-bitcode.test

2

nit: Small nit as this really isn't dependant on what platform the tool runs on, just what platform the bitcode file is for.

[qiongsiwu1]

Thanks @daltenty ! The comment is revised.

[qiongsiwu1]

The pre-commit test failure is most likely resolved by https://github.com/llvm/llvm-project/commit/78d8d016490909ac759c6f76c5f8679bc7a58b2e and not related to this patch. I will land this patch.

llvm/lib/Object/ArchiveWriter.cpp

object::Archive::Kind NewArchiveMember::detectKindFromObject() const {
 
   // If we're adding a bitcode file to the archive, detect the Archive kind
   // based on the target triple.
   LLVMContext Context;
   if (identify_magic(MemBufferRef.getBuffer()) == file_magic::bitcode) {
     if (auto ObjOrErr = object::SymbolicFile::createSymbolicFile(
             MemBufferRef, file_magic::bitcode, &Context)) {
       auto &IRObject = cast<object::IRObjectFile>(**ObjOrErr);
-      return Triple(IRObject.getTargetTriple()).isOSDarwin()
+      auto TargetTriple = Triple(IRObject.getTargetTriple());
+      return TargetTriple.isOSDarwin()
                  ? object::Archive::K_DARWIN
-                 : object::Archive::K_GNU;
+                 : (TargetTriple.isOSAIX() ? object::Archive::K_AIXBIG
+                                           : object::Archive::K_GNU);
     } else {
       // Squelch the error in case this was not a SymbolicFile.
       consumeError(ObjOrErr.takeError());
     }
   }
 
   return object::Archive::getDefaultKindForHost();
 }

llvm/test/tools/llvm-ar/Inputs/aix-foo.ll

+target datalayout = "E-m:a-Fi64-i64:64-n32:64-S128-v256:256:256-v512:512:512"
+target triple = "powerpc64-ibm-aix7.2.0.0"
+
+define signext i32 @foo() {
+entry:
+  ret i32 42
+}
+

llvm/test/tools/llvm-ar/aix-bitcode.test

+# Check if llvm-ar correctly archives bitcode files for AIX.
+# RUN: rm -rf %t && mkdir -p %t
+# RUN: llvm-as %S/Inputs/aix-foo.ll -o %t/aix-foo.bc
+# RUN: llvm-ar qc %t/aix-foo.a %t/aix-foo.bc
+# RUN: FileCheck %s --input-file=%t/aix-foo.a
+
+# CHECK:  bigaf