Re: [PATCH] [gold] Unlock external members of thin archives.

[Cary Coutant <ccoutant at google dot com>]

> gold/
>         * archive.cc (Archive::get_elf_object_for_member): Unlock external
>         members of thin archives so that they may be used by plugins.

Thanks! This is the problem, but Archive::include_member() is supposed
to be responsible for unlocking external members of thin archives, and
does it properly except in the plugin case. I've chosen to fix this by
adding an RAII class to unlock the object when include_member()
returns. I've also modified the test plugin library a bit to make it
easy to add a test case for claiming members of a thin archive.

The failure to unlock these objects is actually the cause of PR 15660
(at least I'm pretty certain of that), which complains that the linker
is running out of file descriptors when linking a very large
application using LTO. The gcc LTO plugin doesn't use the
get_input_file API, so the problem went undetected until actually
running out of available file descriptors.

-cary



2015-02-03  Cary Coutant  <ccoutant@google.com>
            Peter Collingbourne  <pcc@google.com>

gold/
        PR gold/15660
        * archive.cc (Thin_archive_object_unlocker): New class.
        (Archive::include_member): Unlock external members of thin archives.
        * testsuite/Makefile.am (plugin_test_1): Rename .syms files.
        (plugin_test_2): Likewise.
        (plugin_test_3): Likewise.
        (plugin_test_4): Likewise.
        (plugin_test_5): Likewise.
        (plugin_test_6): Likewise.
        (plugin_test_7): Likewise.
        (plugin_test_8): Likewise.
        (plugin_test_9): Likewise.
        (plugin_test_10): Likewise.
        (plugin_test_11): New test case.
        * testsuite/Makefile.in: Regenerate.
        * testsuite/plugin_test.c (claim_file_hook): Check for parallel .syms
        file to decide whether to claim file.
        (all_symbols_read_hook): Likewise.
        * testsuite/plugin_test_1.sh: Adjust expected output.
        * testsuite/plugin_test_2.sh: Likewise.
        * testsuite/plugin_test_3.sh: Likewise.
        * testsuite/plugin_test_6.sh: Likewise.
        * testsuite/plugin_test_tls.sh: Likewise.
        * testsuite/plugin_test_11.sh: New testcase.

Attachment: patch-pr15660.txt
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