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| author | Fangrui Song <maskray@google.com> | 2021-04-16 11:26:39 -0700 |
|---|---|---|
| committer | Fangrui Song <maskray@google.com> | 2021-04-16 11:26:39 -0700 |
| commit | cd6ae7ea5431c2b8f16201fb0e2c413bf8d2df06 (patch) | |
| tree | 68d5b5402097696b3e3898fad40a143720da0438 /config.h.in | |
| parent | 1a8605b6cd257e8a74e29b5b71c057211f5fb847 (diff) | |
| download | glibc-cd6ae7ea5431c2b8f16201fb0e2c413bf8d2df06.tar glibc-cd6ae7ea5431c2b8f16201fb0e2c413bf8d2df06.tar.gz glibc-cd6ae7ea5431c2b8f16201fb0e2c413bf8d2df06.tar.bz2 glibc-cd6ae7ea5431c2b8f16201fb0e2c413bf8d2df06.zip | |
Set the retain attribute on _elf_set_element if CC supports [BZ #27492]
So that text_set_element/data_set_element/bss_set_element defined
variables will be retained by the linker.
Note: 'used' and 'retain' are orthogonal: 'used' makes sure the variable
will not be optimized out; 'retain' prevents section garbage collection
if the linker support SHF_GNU_RETAIN.
GNU ld 2.37 and LLD 13 will support -z start-stop-gc which allow C
identifier name sections to be GCed even if there are live
__start_/__stop_ references.
Without the change, there are some static linking problems, e.g.
_IO_cleanup (libio/genops.c) may be discarded by ld --gc-sections, so
stdout is not flushed on exit.
Note: GCC may warning 'retain' attribute ignored while __has_attribute(retain)
is 1 (https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99587).
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
Diffstat (limited to 'config.h.in')
| -rw-r--r-- | config.h.in | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/config.h.in b/config.h.in index ca1547ae67..96a08c7757 100644 --- a/config.h.in +++ b/config.h.in @@ -187,6 +187,9 @@ /* Define if gcc supports attribute ifunc. */ #undef HAVE_GCC_IFUNC +/* Define if CC supports attribute retain. */ +#undef HAVE_GNU_RETAIN + /* Define if the linker defines __ehdr_start. */ #undef HAVE_EHDR_START |