PING^2: [PATCH] Support -fuse-ld=bfd and -fuse-ld=gold

[H.J. Lu]

On Fri, Dec 7, 2012 at 5:15 AM, H.J. Lu <hjl.tools@gmail.com> wrote:
> On Wed, Nov 28, 2012 at 8:18 PM, H.J. Lu <hjl.tools@gmail.com> wrote:
>>
>> Binutils supports 2 linkers, ld.gold and ld.bfd.  One of them is
>> configured as the default linker, ld, which is used by GCC.  Sometimes,
>> we want to use the alternate linker with GCC at run-time.  This patch
>> adds -fuse-ld=bfd and -fuse-ld=gold options to GCC driver.  It changes
>> collect2.c to pick either ld.bfd or ld.gold.  It also adds
>> ORIGINAL_LD_BFD_FOR_TARGET and ORIGINAL_LD_GOLD_FOR_TARGET to
>> exec-tool.in to add -fuse-ld=bfd and -fuse-ld=gold support to
>> collect-ld.  Since ld.bfd nor ld.gold know the new options, you
>> will get
>>
>> # ./xgcc -B./  /tmp/x.c -fuse-ld=gold -v
>> ...
>> ./collect-ld --eh-frame-hdr -m elf_x86_64 -dynamic-linker /lib64/ld-linux-x86-64.so.2 -fuse-ld=gold /lib/../lib64/crt1.o /lib/../lib64/crti.o ./crtbegin.o -L. -L/lib/../lib64 -L/usr/lib/../lib64 /tmp/cclVWcGz.o -v -lgcc --as-needed -lgcc_s --no-as-needed -lc -lgcc --as-needed -lgcc_s --no-as-needed ./crtend.o /lib/../lib64/crtn.o
>> GNU gold (Linux/GNU Binutils 2.23.51.0.7.20121127) 1.11
>> /usr/local/bin/ld.gold: fatal error: -f/--auxiliary may not be used without -shared
>> collect2: error: ld returned 1 exit status
>>
>> This is because we pass everything to ld and ld.bfd/ld.gold doesn't
>> understand -fuse-ld=bfd/-fuse-ld=gold.  It isn't a problem for collect2
>> since it will filter-out -fuse-ld=bfd/-fuse-ld=gold.  I will submit a
>> binutils patch to ignore -fuse-ld=bfd/-fuse-ld=gold, similar to -flto
>> options.
>>
>> OK to install?
>>
>> Thanks.
>>
>>
>> H.J.
>> ---
>> 2012-11-28   Nick Clifton  <nickc@redhat.com>
>>              Matthias Klose <doko@debian.org>
>>              Doug Kwan  <dougkwan@google.com>
>>              H.J. Lu  <hongjiu.lu@intel.com>
>>
>>         PR driver/55470
>>         * collect2.c (main): Support -fuse-ld=bfd and -fuse-ld=gold.
>>
>>         * common.opt: Add fuse-ld=bfd and fuse-ld=gold.
>>
>>         * gcc.c (LINK_COMMAND_SPEC): Pass -fuse-ld=* to collect2.
>>
>>         * opts.c (comman_handle_option): Ignore -fuse-ld=bfd and
>>         -fuse-ld=gold.
>>
>>         * doc/invoke.texi: Document -fuse-ld=bfd and -fuse-ld=gold.
>
> Here is the minimum patch for 4.8.  OK to install?
>
>

Hi Joseph,

Can you review this?

Thanks.


H.J.