[v3,0/3] Optionally skip linking/copying the built-ins

Message

Kazuhiro Kato via GitGitGadget Aug. 26, 2020, 11:56 a.m. UTC

The dashed form of the built-ins is so passé.

Incidentally, this also handles the .pdb issue in MSVC's install Makefile
target that Peff pointed out in the context of the "slimming down" patch
series
[https://lore.kernel.org/git/[e-mail]/]
.

This addresses https://github.com/gitgitgadget/git/issues/406

Changes since v2:

 * Reworded and clarified the commit messages of the second and third patch.

Changes since v1:

 * Fixed check-docs under SKIP_DASHED_BUILT_INS
 * Renamed ALL_PROGRAMS_AND_BUILT_INS to ALL_COMMANDS_TO_INSTALL to reflect
   its purpose better.
 * Revamped the commit message of patch 2/3 and 3/3.

Johannes Schindelin (3):
  msvc: copy the correct `.pdb` files in the Makefile target `install`
  Optionally skip linking/copying the built-ins
  ci: stop linking built-ins to the dashed versions

 Makefile                  | 71 +++++++++++++++++++++------------------
 ci/run-build-and-tests.sh |  2 +-
 2 files changed, 40 insertions(+), 33 deletions(-)


base-commit: 878e727637ec5815ccb3301eb994a54df95b21b8
Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-411%2Fdscho%2Foptionally-skip-dashed-built-ins-v3
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-411/dscho/optionally-skip-dashed-built-ins-v3
Pull-Request: https://github.com/gitgitgadget/git/pull/411

Range-diff vs v2:

 1:  1880a0e4bf = 1:  1880a0e4bf msvc: copy the correct `.pdb` files in the Makefile target `install`
 2:  166bd0d8fb ! 2:  52deafded5 Optionally skip linking/copying the built-ins
     @@ Commit message
          executable to the dashed name in `libexec/git-core/`), in practice, it
          is probably almost irrelevant.
      
     -    In fact, some platforms (such as Windows) only started gaining
     -    meaningful Git support _after_ the dashed form was deprecated, and
     -    therefore one would expect that all this hard-linking is unnecessary on
     -    those platforms.
     +    However, we *do* care about keeping people's scripts working (even if
     +    they were written before the non-dashed form started to be recommended).
     +
     +    Keeping this backwards-compatibility is not necessarily cheap, though:
     +    even so much as amending the tip commit in a git.git checkout will
     +    require re-linking all of those dashed commands. On this developer's
     +    laptop, this makes a noticeable difference:
     +
     +            $ touch version.c && time make
     +                CC version.o
     +                AR libgit.a
     +                LINK git-bugreport.exe
     +                [... 11 similar lines ...]
     +                LN/CP git-remote-https.exe
     +                LN/CP git-remote-ftp.exe
     +                LN/CP git-remote-ftps.exe
     +                LINK git.exe
     +                BUILTIN git-add.exe
     +                [... 123 similar lines ...]
     +                BUILTIN all
     +                SUBDIR git-gui
     +                SUBDIR gitk-git
     +                SUBDIR templates
     +                LINK t/helper/test-fake-ssh.exe
     +                LINK t/helper/test-line-buffer.exe
     +                LINK t/helper/test-svn-fe.exe
     +                LINK t/helper/test-tool.exe
     +
     +            real    0m36.633s
     +            user    0m3.794s
     +            sys     0m14.141s
     +
     +            $ touch version.c && time make SKIP_DASHED_BUILT_INS=1
     +                CC version.o
     +                AR libgit.a
     +                LINK git-bugreport.exe
     +                [... 11 similar lines ...]
     +                LN/CP git-remote-https.exe
     +                LN/CP git-remote-ftp.exe
     +                LN/CP git-remote-ftps.exe
     +                LINK git.exe
     +                BUILTIN git-receive-pack.exe
     +                BUILTIN git-upload-archive.exe
     +                BUILTIN git-upload-pack.exe
     +                BUILTIN all
     +                SUBDIR git-gui
     +                SUBDIR gitk-git
     +                SUBDIR templates
     +                LINK t/helper/test-fake-ssh.exe
     +                LINK t/helper/test-line-buffer.exe
     +                LINK t/helper/test-svn-fe.exe
     +                LINK t/helper/test-tool.exe
     +
     +            real    0m23.717s
     +            user    0m1.562s
     +            sys     0m5.210s
     +
     +    Also, `.zip` files do not have any standardized support for hard-links,
     +    therefore "zipping up" the executables will result in inflated disk
     +    usage. (To keep down the size of the "MinGit" variant of Git for
     +    Windows, which is distributed as a `.zip` file, the hard-links are
     +    excluded specifically.)
      
          In addition to that, some programs that are regularly used to assess
          disk usage fail to realize that those are hard-links, and heavily
          overcount disk usage. Most notably, this was the case with Windows
     -    Explorer up until the last couple of Windows 10 versions.
     +    Explorer up until the last couple of Windows 10 versions. See e.g.
     +    https://github.com/msysgit/msysgit/issues/58.
      
     -    To save on the time needed to hard-link these dashed commands, and to
     -    eventually stop shipping with those hard-links on Windows, let's
     +    To save on the time needed to hard-link these dashed commands, with the
     +    plan to eventually stop shipping with those hard-links on Windows, let's
          introduce a Makefile knob to skip generating them.
      
          Signed-off-by: Johannes Schindelin <[e-mail]>
 3:  ea23ba5e26 ! 3:  99a5328492 ci: stop linking built-ins to the dashed versions
     @@ Commit message
          the dashed form, even if we deprecated that a _long_ time ago.
      
          For that reason, we just introduced a Makefile knob to skip linking
     -    them. TO make sure that this keeps working, teach the CI
     +    them. To make sure that this keeps working, teach the CI
          (and PR) builds to skip generating those hard-links.
      
     +    This is actually not such a big change: e4597aae6590 (run test suite
     +    without dashed git-commands in PATH, 2009-12-02) made sure that our test
     +    suite does not require dashed commands. With this Makefile knob, the
     +    commitment is just a little stronger (running tests with `--with-dashes`
     +    would _still_ not see the dashed form of the built-ins).
     +
     +    There is a subtle change in behavior with this patch, though: as we no
     +    longer even _build_ the dashed executables, running the test suite would
     +    fail if any of Git's scripted commands (e.g. `git-request-pull`) still
     +    This would have succeeded previously (and would have been unintentional,
     +    of course) because `bin-wrappers/git` sets `GIT_EXEC_PATH` to the
     +    top-level directory (which would still have contained, say,
     +    `git-rev-parse`).
     +
          Signed-off-by: Johannes Schindelin <[e-mail]>
      
       ## ci/run-build-and-tests.sh ##