[COFF] Add support for aligncomm directives

These are emitted for comm symbols in object files, when targeting
a GNU environment.

Alternatively, just ignore them since we already align CommonChunk
to the natural size of the content (up to 32 bytes). That would only
trade away the possibility to overalign small symbols, which doesn't
sound like something that might not need to be handled?

Differential Revision: https://reviews.llvm.org/D36304

llvm-svn: 310871

1 files changed, 4 insertions, 0 deletions

diff --git a/lld/COFF/Chunks.cpp b/lld/COFF/Chunks.cpp
index 297cde2f5ae..43bb4d4c8f2 100644
--- a/lld/COFF/Chunks.cpp
+++ b/lld/COFF/Chunks.cpp
@@ -377,6 +377,10 @@ CommonChunk::CommonChunk(const COFFSymbolRef S) : Sym(S) {
   Align = std::min(uint64_t(32), PowerOf2Ceil(Sym.getValue()));
 }
 
+void CommonChunk::setAlign(uint32_t NewAlign) {
+  Align = std::max(Align, NewAlign);
+}
+
 uint32_t CommonChunk::getPermissions() const {
   return IMAGE_SCN_CNT_UNINITIALIZED_DATA | IMAGE_SCN_MEM_READ |
          IMAGE_SCN_MEM_WRITE;