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| author | Nick Alcock <nick.alcock@oracle.com> | 2020-06-11 20:19:07 +0100 |
|---|---|---|
| committer | Nick Alcock <nick.alcock@oracle.com> | 2020-07-22 18:05:32 +0100 |
| commit | fa03171fb46381f904c3434bd0e3d23b54783b2f (patch) | |
| tree | 6944f4f31eeeb2f5aebba24f1cd8e2994ccc5afb /ld | |
| parent | 7cdfc3462fbbb27727ddd83d356cf79af8854740 (diff) | |
| download | gdb-fa03171fb46381f904c3434bd0e3d23b54783b2f.zip gdb-fa03171fb46381f904c3434bd0e3d23b54783b2f.tar.gz gdb-fa03171fb46381f904c3434bd0e3d23b54783b2f.tar.bz2 | |
ld: do not produce one empty output .ctf section for every input .ctf
The trick we use to prevent ld doing as it does for almost all other
sections and copying the input CTF section into the output has recently
broken, causing output to be produced with a valid CTF section followed
by massive numbers of CTF sections, one per .ctf in the input (minus
one, for the one that was filled out by ctf_link). Their size is being
forcibly set to zero, but they're still present, wasting space and
looking ridiculous.
This is not right:
ld/ld-new :
section size addr
.interp 28 4194984
[...]
.bss 21840 6788544
.comment 92 0
.ctf 87242 0
.ctf 0 0
.ctf 0 0
[snip 131 more empty sections]
.gnu.build.attributes 7704 6818576
.debug_aranges 6592 0
.debug_info 4488859 0
.debug_abbrev 150099 0
.debug_line 796759 0
.debug_str 237926 0
.debug_loc 2247302 0
.debug_ranges 237920 0
Total 10865285
The fix is to exclude these unwanted input sections from being present
in the output. We tried this before and it broke things, because if you
exclude all the .ctf sections there isn't going to be one in the output
so there is nowhere to put the deduplicated CTF. The solution to that is
really simple: set SEC_EXCLUDE on *all but one* CTF section. We don't
care which one (they're all the same once their size has been zeroed),
so just pick the first we see.
ld/
* ldlang.c (ldlang_open_ctf): Set SEC_EXCLUDE on all but the
first input .ctf section.
Diffstat (limited to 'ld')
| -rw-r--r-- | ld/ChangeLog | 5 | ||||
| -rw-r--r-- | ld/ldlang.c | 5 |
2 files changed, 9 insertions, 1 deletions
diff --git a/ld/ChangeLog b/ld/ChangeLog index bd0c6cc..c0f6eca 100644 --- a/ld/ChangeLog +++ b/ld/ChangeLog @@ -1,5 +1,10 @@ 2020-07-22 Nick Alcock <nick.alcock@oracle.com> + * ldlang.c (ldlang_open_ctf): Set SEC_EXCLUDE on all but the + first input .ctf section. + +2020-07-22 Nick Alcock <nick.alcock@oracle.com> + * configure.ac (enable_libctf): Substitute it. * Makefile.am (enablings.exp): New. (EXTRA_DEJAGNU_SITE_CONFIG): Add it. diff --git a/ld/ldlang.c b/ld/ldlang.c index bf29144..6943adf 100644 --- a/ld/ldlang.c +++ b/ld/ldlang.c @@ -3700,12 +3700,15 @@ ldlang_open_ctf (void) } /* Prevent the contents of this section from being written, while - requiring the section itself to be duplicated in the output. */ + requiring the section itself to be duplicated in the output, but only + once. */ /* This section must exist if ctf_bfdopen() succeeded. */ sect = bfd_get_section_by_name (file->the_bfd, ".ctf"); sect->size = 0; sect->flags |= SEC_NEVER_LOAD | SEC_HAS_CONTENTS | SEC_LINKER_CREATED; + if (any_ctf) + sect->flags |= SEC_EXCLUDE; any_ctf = 1; } |