Am 13.03.2018 um 21:39 schrieb Ævar Arnfjörð Bjarmason:
Add a INSTALL_SYMLINKS option which if enabled, changes the default
hardlink installation method to one where the relevant binaries in
libexec/git-core are symlinked back to ../../bin, instead of being
hardlinked.
This new option also overrides the behavior of the existing
NO_*_HARDLINKS variables which in some cases would produce symlinks
within to libexec/, e.g. "git-add" symlinked to "git" which would be
copy of the "git" found in bin/, now "git-add" in libexec/ is always
going to be symlinked to the "git" found in the bin/ directory.
It is important to leave the default at hard-linking the binaries,
because on Windows symbolic links are second class citizens (they
require special privileges and there is a distinction between link
targets being files or directories). Hard links work well.
This option is being added because:
1) I think it makes what we're doing a lot more obvious. E.g. I'd
never noticed that the libexec binaries were really just hardlinks
since e.g. ls(1) won't show that in any obvious way. You need to
start stat(1)-ing things and look at the inodes to see what's
going on.
2) Some tools have very crappy support for hardlinks, e.g. the Git
shipped with GitLab is much bigger than it should be because
they're using a chef module that doesn't know about hardlinks, see
https://github.com/chef/omnibus/issues/827
I've also ran into other related issues that I think are explained
s/ran/run/
by this, e.g. compiling git with debugging and rpm refusing to
install a ~200MB git package with 2GB left on the FS, I think that
was because it doesn't consider hardlinks, just the sum of the
byte size of everything in the package.
As for the implementation, the "../../bin" noted above will vary given
some given some values of "../.." and "bin" depending on the depth of
s/given some//
the gitexecdir relative to the destdir, and the "bindir" target,
e.g. setting "bindir=/tmp/git/binaries gitexecdir=foo/bar/baz" will do
the right thing and produce this result:
$ file /tmp/git/foo/bar/baz/git-add
/tmp/git/foo/bar/baz/git-add: symbolic link to ../../../binaries/git
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@xxxxxxxxx>
---
Makefile | 46 +++++++++++++++++++++++++++++++---------------
1 file changed, 31 insertions(+), 15 deletions(-)
diff --git a/Makefile b/Makefile
index ee0b6c8940..ac7616422d 100644
--- a/Makefile
+++ b/Makefile
@@ -329,6 +329,13 @@ all::
# when hardlinking a file to another name and unlinking the original file right
# away (some NTFS drivers seem to zero the contents in that scenario).
#
+# Define INSTALL_SYMLINKS if you prefer to have everything that can be
+# symlinked between bin/ and libexec/ to use relative symlinks between
+# the two. This option overrides NO_CROSS_DIRECTORY_HARDLINKS and
s/ between the two//
+# NO_INSTALL_HARDLINKS which will also use symlinking by indirection
+# within the same directory in some cases, INSTALL_SYMLINKS will
+# always symlink to the final target directly.
"the final target"? Do you mean "the git executable installed in
$bindir" or something like this?
+#
# Define NO_CROSS_DIRECTORY_HARDLINKS if you plan to distribute the installed
# programs as a tar, where bin/ and libexec/ might be on different file systems.
#
@@ -2594,35 +2601,44 @@ endif
bindir=$$(cd '$(DESTDIR_SQ)$(bindir_SQ)' && pwd) && \
execdir=$$(cd '$(DESTDIR_SQ)$(gitexec_instdir_SQ)' && pwd) && \
+ destdir_from_execdir_SQ=$$(echo '$(gitexecdir_relative_SQ)' | sed -e 's|[^/][^/]*|..|g') && \
{ test "$$bindir/" = "$$execdir/" || \
for p in git$X $(filter $(install_bindir_programs),$(ALL_PROGRAMS)); do \
$(RM) "$$execdir/$$p" && \
- test -z "$(NO_INSTALL_HARDLINKS)$(NO_CROSS_DIRECTORY_HARDLINKS)" && \
- ln "$$bindir/$$p" "$$execdir/$$p" 2>/dev/null || \
- cp "$$bindir/$$p" "$$execdir/$$p" || exit; \
+ test -n "$(INSTALL_SYMLINKS)" && \
+ ln -s "$$destdir_from_execdir_SQ/$(bindir_relative_SQ)/$$p" "$$execdir/$$p" || \
+ { test -z "$(NO_INSTALL_HARDLINKS)$(NO_CROSS_DIRECTORY_HARDLINKS)" && \
+ ln "$$bindir/$$p" "$$execdir/$$p" 2>/dev/null || \
+ cp "$$bindir/$$p" "$$execdir/$$p" || exit; } \
I think that it is unnecessary to place the later options in {} brackets
because && and || have equal precedence in shell scripts. That is:
want symlinks? &&
make symlinks ||
want hard links? &&
make hard links ||
make copies ||
exit
Of course, it means that when symlinking fails, it falls back to hard
links (if permitted) or copies, whichever works. But that also happens
with your version.
(Ditto in the rest of the hunk, which I don't repeat here.)
-- Hannes
