periperidip
commented
4 years ago Most of that business logic is implemented in submodule.c.`
How does one distinguish between which function to add in the aforementioned file and in submodule--helper.c?
It appears that
cmd_add,cmd_init,cmd_deinit, (partially)cmd_update, (partially)cmd_set_branchandcmd_summarystill need to be ported whilecmd_foreach,cmd_status,cmd_syncandcmd_absorbgitdirsalready use the submodule--helper-provided built-in code.
I think that cmd_init and cmd_deinit have been converted(unless some partial conversion is left). Those left for conversion are: cmd_summary, cmd_set_branch, cmd_set_url and cmd_add. Also, if cmd_update is partially converted then what exactly is left to convert in the subcommand? On observation of code in submodule--helper.c, it seems that set-branch and set-url have many helpers created already as part of other commands, hence they may be prove to be useful at the end.
It is highly recommended to contribute this work in small chunks, e.g. as soon as cmd_set_branch is done, even if it is not working yet (in which case it should be marked as request for help). The hardest part, as with every project, is to get started, from there on it will be easier.
I have started work on cmd_summary() and have implemented the frontend function module_summary() as of now. I aim to implement big chunks of the subcommand in the coming days.
dscho
pratikghule
phil-blain
The
git-submodule.shscript weighs in with just over 1,000 lines. That is a rather tall order, so most likely it will take the equivalent of multiple Google Summer of Code projects to finish.Taking a bit of a deeper look into the
git-submodule.shscript, we see a peculiar pattern in some of the subcommands, e.g. incmd_foreach: https://github.com/git/git/blob/v2.21.0/git-submodule.sh#L320-L349Essentially, it spends two handfuls of lines on option parsing, and then the real business logic is performed by the
submodule--helper, which is already a built-in.Most of that business logic is implemented in
submodule.c.The important part is to identify those commands in
git-submodule.shthat do not yet follow this pattern "parse options then hand off to submodule--helper". See more on that below.The commit history of the commands that do use the
submodule--helperwill help see how they were converted, what conventions were used, whether there were recurring patterns, etc. This style should be imitated for the rest of the conversion.An important thing to realize is that it is not so much a conversion as a re-implementation, and the best way to go about it is incremental.
Take for example the
git submodule initsubcommand. It has been re-implemented in C a long time ago, and the shell script version merely parses the command-line arguments and then passes them on to the built-ingit submodule--helpercommand:https://github.com/git/git/blob/v2.24.1/git-submodule.sh#L361-L390
It probably would make sense to study the initial re-implementation (or "port"): 3604242f080a813d6f20a7394def422d1e55b30e
It appears that
cmd_add,cmd_init,cmd_deinit, (partially)cmd_update, (partially)cmd_set_branchandcmd_summarystill need to be ported whilecmd_foreach,cmd_status,cmd_syncandcmd_absorbgitdirsalready use thesubmodule--helper-provided built-in code.The easiest of the sub-commands that still need to be ported might be
cmd_set_branch. In the git.git fork of the contributor who started the porting effort, there are some branches that might or might not have useful commits in them, but given thatset_branchalready calls thesubmodule--helpera couple of times and does little on its own, it might make sense to just do that port "from scratch".The idea here will be to pass the options using the construct
${GIT_QUIET:+--quiet}(which expands to--quietif$GIT_QUIETwould expand to a non-empty string) to thesubmodule--helper, and to add a new sub-command to said helper, by implementingstatic int set_branch(int argc, const char **argv, const char *prefix)inbuiltin/submodule--helper.cand appending the corresponding entry to thecommandsarray.Likewise, it should be easy to figure out which functions are used by the
submodule--helperto perform the actions asked for by the current shell script functioncmd_set_branch, and call them directly from the newly-implementedset_branch()function inbuiltin/submodule--helper.c.It is highly recommended to contribute this work in small chunks, e.g. as soon as
cmd_set_branchis done, even if it is not working yet (in which case it should be marked as request for help). The hardest part, as with every project, is to get started, from there on it will be easier.