Re: [PATCH 1/6] Makefile: symlink the same way under "symlinks" and "no hardlinks"
From: Junio C Hamano <hidden>
Date: 2021-03-29 22:18:28
Ævar Arnfjörð Bjarmason [off-list ref] writes:
In particular INSTALL_SYMLINKS=Y will result in a link tree like:
bin/git
libexec/git -> ../bin/git
libexec/git-add -> ../bin/git
Whereas NO_INSTALL_HARDLINKS=Y in cases where the "ln" would fail would result in:
bin/git
libexec/git
libexec/git-add -> git
I.e. we duplicated the "git" between the bin/ and libexec/
directories (by default they're hardlinked), and potentially had had
e.g. "git-add" pointing at the libexec/git hardlink (or more likely if
"ln" is failing, a copy), instead of the bin/git.
Now we'll instead use the same symlinks to point to the bindir. I
don't see any reason not to do so, and no breakage related to this has
been reported with INSTALL_SYMLINKS in all this time. I just did it
this way to maintain bug-for-bug compatibility at the time.Makes sense. I do not see a reason why libexec/git-add that points at ../bin/git would cause problems, either.
quoted hunk
+# Define NO_INSTALL_HARDLINKS if you'd like to have programs in bin/ +# and libexec/ either symlinked (we try with INSTALL_SYMLINKS first), +# or if that fails fall back on a "cp" instead of a "ln". Useful for +# when you don't want hardlinks at all.
So without INSTALL_SYMLINKS and with NO_INSTALL_HARDLINKS, the only remaining choice is "cp". With both set, we favour "ln -s" over "cp" and do not allow "ln". With INSTALL_SYMLINKS and without NO_INSTALL_HARDLINKS, we try "ln -s", "ln" and finally "cp". With neither, we try "ln" and fall back to "cp"? That precedence order does make sense.
quoted hunk
@@ -3019,33 +3020,30 @@ endif } && \ for p in $(filter $(install_bindir_programs),$(BUILT_INS)); do \ $(RM) "$$bindir/$$p" && \ - test -n "$(INSTALL_SYMLINKS)" && \ + test -n "$(INSTALL_SYMLINKS)" -o "$(NO_INSTALL_HARDLINKS)" && \
I had an impression that we avoid -o/-a used with "test" (instead we'd use "test && test" or "test || test")? In either case, if we are told to favor "ln -s", or told not to use "ln", we try "ln -s"? That does not make much sense to me, though. What do I need to do if I do not ever want symbolic links? Is it impossible now?
quoted hunk
ln -s "git$X" "$$bindir/$$p" || \ { test -z "$(NO_INSTALL_HARDLINKS)" && \ ln "$$bindir/git$X" "$$bindir/$$p" 2>/dev/null || \ - ln -s "git$X" "$$bindir/$$p" 2>/dev/null || \ cp "$$bindir/git$X" "$$bindir/$$p" || exit; }; \ done && \ for p in $(BUILT_INS); do \ $(RM) "$$execdir/$$p" && \ if test -z "$(SKIP_DASHED_BUILT_INS)"; \ then \ - test -n "$(INSTALL_SYMLINKS)" && \ + test -n "$(INSTALL_SYMLINKS)" -o "$(NO_INSTALL_HARDLINKS)" && \
Perhaps the same comment applies here and to the next hunk, too?
quoted hunk
ln -s "$$destdir_from_execdir_SQ/$(bindir_relative_SQ)/git$X" "$$execdir/$$p" || \ { test -z "$(NO_INSTALL_HARDLINKS)" && \ ln "$$execdir/git$X" "$$execdir/$$p" 2>/dev/null || \ - ln -s "git$X" "$$execdir/$$p" 2>/dev/null || \ cp "$$execdir/git$X" "$$execdir/$$p" || exit; }; \ fi \ done && \ remote_curl_aliases="$(REMOTE_CURL_ALIASES)" && \ for p in $$remote_curl_aliases; do \ $(RM) "$$execdir/$$p" && \ - test -n "$(INSTALL_SYMLINKS)" && \ + test -n "$(INSTALL_SYMLINKS)" -o "$(NO_INSTALL_HARDLINKS)" && \ ln -s "git-remote-http$X" "$$execdir/$$p" || \ { test -z "$(NO_INSTALL_HARDLINKS)" && \ ln "$$execdir/git-remote-http$X" "$$execdir/$$p" 2>/dev/null || \ - ln -s "git-remote-http$X" "$$execdir/$$p" 2>/dev/null || \ cp "$$execdir/git-remote-http$X" "$$execdir/$$p" || exit; } \ done && \ ./check_bindir "z$$bindir" "z$$execdir" "$$bindir/git-add$X"