https://gcc.gnu.org/bugzilla/show_bug.cgi?id=192
Fangrui Song <i at maskray dot me> changed:
What |Removed |Added
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CC| |i at maskray dot me
--- Comment #19 from Fangrui Song <i at maskray dot me> ---
(In reply to Jakub Jelinek from comment #14)
> This doesn't really look like a good idea to me. Instead, perhaps ld's
> --gc-sections or new special option should just remove unused string
> literals from mergeable sections.
> With your patch, I bet you lose e.g. all tail merging. Consider:
> const char *used1 () { return "foo bar baz blah blah"; }
> in one TU and
> const char *used2 () { return "bar baz blah blah"; }
> in another. The linker necessarily knows which strings (or other data) in
> mergeable sections are used and which are unused.
I second Jakub's idea that the linker should perform the constant merge (which
is implemented in LLD): the cost of a section header (sizeof(Elf64_Shdr)=64) +
a section name (".rodata.xxx.str1.1") is quite large.
Created a GNU ld (and gold) feature request:
https://sourceware.org/bugzilla/show_bug.cgi?id=26622
