It looks like only the presence of the entry is important, but by
convention, GNU ld and lld set 0 to a DT_AARCH64_VARIANT_PCS dynamic
entry, so we should follow suit.
Keeping DEC Alpha support is difficult because there are no Alpha
machines available for toolchain developers, and even if there were,
no modern Linux distros still support Alpha. For example, Debian
dropped Alpha support in Debian 6.0. As a result, I cannot test my
linker with real-world programs.
In fact, I believe mold has never been able to link real-world large
programs. Object files for Alpha are compiled with the small code
model by default, so it is not easy to support it in the linker.
There's no means to verify that my implementation is correct for Alpha
because Alpha's psABI has never been published by DEC. The most
"reliable" source of correctness is GNU ld's source code and comments.
Last but not least, I believe there are literally zero mold/Alpha
users. Unlike some other retro computers like the m68k, Alpha doesn't
seem to get much love from the community, perhaps because the
availability of Alpha machines was limited in the first place, even in
the 90s.
Therefore, I'll remove Alpha support now. If there's someone who wants
to keep it, we can resurrect and re-test it.
This change should make the mold binary size a little smaller.
This commit reverts 0612ea41f1 and
instead solves the original issue with a different approach.
Now, if a hidden symbol was resolved to a DSO symbol, we'll redo
symbol resolution so that the symbol won't be resolved to the same one
next time.
This should fix our build-all buildbot.
Assume both `foo.a` and `bar.so` define the same symbol `baz`.
If `baz`'s symbol visibility is hidden, it needs to be resolved within
the output file, i.e., from `foo.a`. However, previously, such symbol
was resolved to the one in `bar.so`.
To fix the problem, we'll lower the symbol priority for DSOs.
Fixes https://github.com/rui314/mold/issues/1342
Word-size absolute relocations, such as R_X86_64_64, are special from
the linker's point of view because only such symbols can be promoted
to dynamic symbols. This patch handles them separately.
