| Message ID | 20240111080417.59346-1-mi.al.lohmann@gmail.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | builtin/revert.c: refactor using an enum for cmd-action | expand |
Hi Michael On 11/01/2024 08:04, Michael Lohmann wrote: > This is done to avoid having to keep the char values in sync in > different places and also to get compiler warnings on non-exhaustive > switches. I think this is a reasonable change, thanks for working on it. > The newly introduced `revert_action`-enum aligns with the > builtin/rebase.c `action`-enum though the name `revert_action` is chosen > to better differentiate it from `replay_opts->action` with a different > function. For rebase the equivalent of the latter is > `rebase_options->type` and `rebase_options->action` corresponds to the > `cmd` variable in revert.c. > > In the rebase `action` enum there is the enumeration constant > `ACTION_NONE` which is not particularly descriptive, since it seems to > imply that no action should be taken. Instead it signals a start of a > revert/cherry-pick process, so here `REVERT_ACTION_START` was chosen. I think ACTION_NONE was intended to covey that the user did not pass one of the OPT_CMDMODE() options like "--continue" as there isn't a "--start" option. I don't have a strong opinion between "_NONE" and "_START". > +enum revert_action { > + REVERT_ACTION_START = 0, > + REVERT_ACTION_CONTINUE, > + REVERT_ACTION_SKIP, > + REVERT_ACTION_ABORT, > + REVERT_ACTION_QUIT, > +}; The "REVERT_" prefix is a bit unfortunate as this is used by cherry-pick as well but it does match the filename. As this enum is only used in this file I'd be quite happy to drop the "REVERT_" prefix. (I don't think we need to go messing with the "action" member of struct replay_opts to do that) > /* Check for incompatible command line arguments */ > - if (cmd) { > - char *this_operation; > - if (cmd == 'q') > + { > + char *this_operation = 0; style note: we use "NULL" rather than "0" when initializing pointers. Ideally this would be a "const char *" as we assign string literals but that is not a new problem with this patch. > + switch (cmd) { > + case REVERT_ACTION_START: > + break; I can see the attraction of using an exhaustive switch() here but as we don't want to do anything in the _START case it gets a bit messy with the extra conditional below. I wonder if we'd be better to replace "if (cmd) {" with "if (cmd != REVERT_ACTION_START) {". Alternatively if you want to stick with the switch then declaring "this_operation" at the beginning of the function would mean you can get rid of the new "{}" block. > + case REVERT_ACTION_QUIT: > this_operation = "--quit"; > - else if (cmd == 'c') > + break; > + case REVERT_ACTION_CONTINUE: > this_operation = "--continue"; > - else if (cmd == 's') > + break; > + case REVERT_ACTION_SKIP: > this_operation = "--skip"; > - else { > - assert(cmd == 'a'); > + break; > + case REVERT_ACTION_ABORT: > this_operation = "--abort"; > + break; > } > > - verify_opt_compatible(me, this_operation, > - "--no-commit", opts->no_commit, > - "--signoff", opts->signoff, > - "--mainline", opts->mainline, > - "--strategy", opts->strategy ? 1 : 0, > - "--strategy-option", opts->xopts.nr ? 1 : 0, > - "-x", opts->record_origin, > - "--ff", opts->allow_ff, > - "--rerere-autoupdate", opts->allow_rerere_auto == RERERE_AUTOUPDATE, > - "--no-rerere-autoupdate", opts->allow_rerere_auto == RERERE_NOAUTOUPDATE, > - NULL); > + if (this_operation) The extra indentation here is unfortunate as some of the lines are rather long already. In the current code it is clear that we only call verify_opt_compatible() when cmd is non-nul, I think it would be clearer to use "if (cmd != REVERT_ACTION_START)" here. > + verify_opt_compatible(me, this_operation, > + "--no-commit", opts->no_commit, > + "--signoff", opts->signoff, > + "--mainline", opts->mainline, > + "--strategy", opts->strategy ? 1 : 0, > + "--strategy-option", opts->xopts.nr ? 1 : 0, > + "-x", opts->record_origin, > + "--ff", opts->allow_ff, > + "--rerere-autoupdate", opts->allow_rerere_auto == RERERE_AUTOUPDATE, > + "--no-rerere-autoupdate", opts->allow_rerere_auto == RERERE_NOAUTOUPDATE, > + NULL); > } > [...] > - if (cmd) { > - opts->revs = NULL; > - } else { > + if (cmd == REVERT_ACTION_START) { I was momentarily confused by this change but you're reversing the conditional. I agree that the result is an improvement. Best Wishes Phillip
Phillip Wood <phillip.wood123@gmail.com> writes: > I think ACTION_NONE was intended to covey that the user did not pass > one of the OPT_CMDMODE() options like "--continue" as there isn't a > "--start" option. I don't have a strong opinion between "_NONE" and > "_START". I agree with you why NONE is called as such. If "revert" does not take "--start" (I do not remember offhand), I would think it would be better to follow suit.
diff --git a/builtin/revert.c b/builtin/revert.c index 89821bab95..b5278b7a3b 100644 --- a/builtin/revert.c +++ b/builtin/revert.c @@ -20,6 +20,14 @@ * Copyright (c) 2005 Junio C Hamano */ +enum revert_action { + REVERT_ACTION_START = 0, + REVERT_ACTION_CONTINUE, + REVERT_ACTION_SKIP, + REVERT_ACTION_ABORT, + REVERT_ACTION_QUIT, +}; + static const char * const revert_usage[] = { N_("git revert [--[no-]edit] [-n] [-m <parent-number>] [-s] [-S[<keyid>]] <commit>..."), N_("git revert (--continue | --skip | --abort | --quit)"), @@ -85,12 +93,12 @@ static int run_sequencer(int argc, const char **argv, const char *prefix, const char * const * usage_str = revert_or_cherry_pick_usage(opts); const char *me = action_name(opts); const char *cleanup_arg = NULL; - int cmd = 0; + enum revert_action cmd = REVERT_ACTION_START; struct option base_options[] = { - OPT_CMDMODE(0, "quit", &cmd, N_("end revert or cherry-pick sequence"), 'q'), - OPT_CMDMODE(0, "continue", &cmd, N_("resume revert or cherry-pick sequence"), 'c'), - OPT_CMDMODE(0, "abort", &cmd, N_("cancel revert or cherry-pick sequence"), 'a'), - OPT_CMDMODE(0, "skip", &cmd, N_("skip current commit and continue"), 's'), + OPT_CMDMODE(0, "quit", &cmd, N_("end revert or cherry-pick sequence"), REVERT_ACTION_QUIT), + OPT_CMDMODE(0, "continue", &cmd, N_("resume revert or cherry-pick sequence"), REVERT_ACTION_CONTINUE), + OPT_CMDMODE(0, "abort", &cmd, N_("cancel revert or cherry-pick sequence"), REVERT_ACTION_ABORT), + OPT_CMDMODE(0, "skip", &cmd, N_("skip current commit and continue"), REVERT_ACTION_SKIP), OPT_CLEANUP(&cleanup_arg), OPT_BOOL('n', "no-commit", &opts->no_commit, N_("don't automatically commit")), OPT_BOOL('e', "edit", &opts->edit, N_("edit the commit message")), @@ -144,30 +152,37 @@ static int run_sequencer(int argc, const char **argv, const char *prefix, } /* Check for incompatible command line arguments */ - if (cmd) { - char *this_operation; - if (cmd == 'q') + { + char *this_operation = 0; + switch (cmd) { + case REVERT_ACTION_START: + break; + case REVERT_ACTION_QUIT: this_operation = "--quit"; - else if (cmd == 'c') + break; + case REVERT_ACTION_CONTINUE: this_operation = "--continue"; - else if (cmd == 's') + break; + case REVERT_ACTION_SKIP: this_operation = "--skip"; - else { - assert(cmd == 'a'); + break; + case REVERT_ACTION_ABORT: this_operation = "--abort"; + break; } - verify_opt_compatible(me, this_operation, - "--no-commit", opts->no_commit, - "--signoff", opts->signoff, - "--mainline", opts->mainline, - "--strategy", opts->strategy ? 1 : 0, - "--strategy-option", opts->xopts.nr ? 1 : 0, - "-x", opts->record_origin, - "--ff", opts->allow_ff, - "--rerere-autoupdate", opts->allow_rerere_auto == RERERE_AUTOUPDATE, - "--no-rerere-autoupdate", opts->allow_rerere_auto == RERERE_NOAUTOUPDATE, - NULL); + if (this_operation) + verify_opt_compatible(me, this_operation, + "--no-commit", opts->no_commit, + "--signoff", opts->signoff, + "--mainline", opts->mainline, + "--strategy", opts->strategy ? 1 : 0, + "--strategy-option", opts->xopts.nr ? 1 : 0, + "-x", opts->record_origin, + "--ff", opts->allow_ff, + "--rerere-autoupdate", opts->allow_rerere_auto == RERERE_AUTOUPDATE, + "--no-rerere-autoupdate", opts->allow_rerere_auto == RERERE_NOAUTOUPDATE, + NULL); } if (!opts->strategy && opts->default_strategy) { @@ -183,9 +198,7 @@ static int run_sequencer(int argc, const char **argv, const char *prefix, "--edit", opts->edit > 0, NULL); - if (cmd) { - opts->revs = NULL; - } else { + if (cmd == REVERT_ACTION_START) { struct setup_revision_opt s_r_opt; opts->revs = xmalloc(sizeof(*opts->revs)); repo_init_revisions(the_repository, opts->revs, NULL); @@ -198,6 +211,8 @@ static int run_sequencer(int argc, const char **argv, const char *prefix, memset(&s_r_opt, 0, sizeof(s_r_opt)); s_r_opt.assume_dashdash = 1; argc = setup_revisions(argc, argv, opts->revs, &s_r_opt); + } else { + opts->revs = NULL; } if (argc > 1) @@ -210,19 +225,22 @@ static int run_sequencer(int argc, const char **argv, const char *prefix, opts->strategy = xstrdup(getenv("GIT_TEST_MERGE_ALGORITHM")); free(options); - if (cmd == 'q') { + switch (cmd) { + case REVERT_ACTION_QUIT: { int ret = sequencer_remove_state(opts); if (!ret) remove_branch_state(the_repository, 0); return ret; } - if (cmd == 'c') + case REVERT_ACTION_CONTINUE: return sequencer_continue(the_repository, opts); - if (cmd == 'a') + case REVERT_ACTION_ABORT: return sequencer_rollback(the_repository, opts); - if (cmd == 's') + case REVERT_ACTION_SKIP: return sequencer_skip(the_repository, opts); - return sequencer_pick_revisions(the_repository, opts); + case REVERT_ACTION_START: + return sequencer_pick_revisions(the_repository, opts); + } } int cmd_revert(int argc, const char **argv, const char *prefix)
This is done to avoid having to keep the char values in sync in different places and also to get compiler warnings on non-exhaustive switches. The newly introduced `revert_action`-enum aligns with the builtin/rebase.c `action`-enum though the name `revert_action` is chosen to better differentiate it from `replay_opts->action` with a different function. For rebase the equivalent of the latter is `rebase_options->type` and `rebase_options->action` corresponds to the `cmd` variable in revert.c. In the rebase `action` enum there is the enumeration constant `ACTION_NONE` which is not particularly descriptive, since it seems to imply that no action should be taken. Instead it signals a start of a revert/cherry-pick process, so here `REVERT_ACTION_START` was chosen. Co-authored-by: Wanja Henze <wanja.hentze@bevuta.com> Signed-off-by: Michael Lohmann <mi.al.lohmann@gmail.com> --- Hello! When I was working on `revert/cherry-pick --show-current-patch` (still needs a little bit more discussion, if actually wanted, see thread [1]) I found the construct with the `cmd` as an int a bit irritating. I hope this patch makes it more obvious what is actually going on. Is there a reason why `ACTION_NONE` was chosen as a name in builtin/rebase.c? My best guess is that it came along because it is the implied action when no other specific action is passed in, but I don't find that particularly descriptive on what its actual function is... (Yes, naming things is hard... :D) An alternative to prefixing the enum name with "revert_" would be to rename `replay_opts->action` to `replay_opts->type` so it aligns with rebase. Would you prefer that instead? Cheers Michael [1] https://lore.kernel.org/git/20231218121048.68290-1-mi.al.lohmann@gmail.com/ builtin/revert.c | 80 +++++++++++++++++++++++++++++------------------- 1 file changed, 49 insertions(+), 31 deletions(-)