Do not allocate space for common symbols with -r

Currently ld.lld -r allocates space for common symbols, whereas ld.bfd
-r doesn't.  As a result the OpenBSD makefile bits for creating libraries
fail as they use ld -X -r to strip local symbols, which results in
duplicate symbol errors because space for the common symbols has been
allocated.

The diff also implements the --define-commons option such that allocation
of commons can be forced even if -r is used.

Patch by Mark Kettenis.

llvm-svn: 292878

1 files changed, 2 insertions, 0 deletions

diff --git a/lld/ELF/Driver.cpp b/lld/ELF/Driver.cpp
index eeda973daae..b6b417e8665 100644
--- a/lld/ELF/Driver.cpp
+++ b/lld/ELF/Driver.cpp
@@ -498,6 +498,8 @@ void LinkerDriver::readConfigs(opt::InputArgList &Args) {
   Config->Pie = getArg(Args, OPT_pie, OPT_nopie, false);
   Config->PrintGcSections = Args.hasArg(OPT_print_gc_sections);
   Config->Relocatable = Args.hasArg(OPT_relocatable);
+  Config->DefineCommon = getArg(Args, OPT_define_common, OPT_no_define_common,
+                                !Config->Relocatable);
   Config->Discard = getDiscardOption(Args);
   Config->SaveTemps = Args.hasArg(OPT_save_temps);
   Config->SingleRoRx = Args.hasArg(OPT_no_rosegment);