Object: pad out BSD archive members to 8-bytes
ld64 requires its archive members to be 8-byte aligned for 64-bit
content and 4-byte aligned for 32-bit content. Opt for the larger
alignment requirement. This ensures that ld64 can consume archives
generated by llvm-ar.
Thanks to Kevin Enderby for the hint about the ld64/cctools behaviours!
Resolves PR28361!
llvm-svn: 294615
diff --git a/llvm/lib/Object/ArchiveWriter.cpp b/llvm/lib/Object/ArchiveWriter.cpp
index 4504724..fc827d3 100644
--- a/llvm/lib/Object/ArchiveWriter.cpp
+++ b/llvm/lib/Object/ArchiveWriter.cpp
@@ -395,18 +395,28 @@
std::vector<unsigned> MemberOffset;
for (const NewArchiveMember &M : NewMembers) {
MemoryBufferRef File = M.Buf->getMemBufferRef();
+ unsigned Padding = 0;
unsigned Pos = Out.tell();
MemberOffset.push_back(Pos);
+ // ld64 expects the members to be 8-byte aligned for 64-bit content and at
+ // least 4-byte aligned for 32-bit content. Opt for the larger encoding
+ // uniformly. This matches the behaviour with cctools and ensures that ld64
+ // is happy with archives that we generate.
+ if (Kind == object::Archive::K_BSD)
+ Padding = OffsetToAlignment(M.Buf->getBufferSize(), 8);
+
printMemberHeader(Out, Kind, Thin,
sys::path::filename(M.Buf->getBufferIdentifier()),
StringMapIndexIter, M.ModTime, M.UID, M.GID, M.Perms,
- M.Buf->getBufferSize());
+ M.Buf->getBufferSize() + Padding);
if (!Thin)
Out << File.getBuffer();
+ while (Padding--)
+ Out << '\n';
if (Out.tell() % 2)
Out << '\n';
}