From f6aa7ecc34373f32621b05659d5d2447d690be18 Mon Sep 17 00:00:00 2001 From: Johannes Schindelin Date: Fri, 13 Dec 2019 08:07:48 +0000 Subject: built-in add -i: start implementing the `patch` functionality in C In the previous steps, we re-implemented the main loop of `git add -i` in C, and most of the commands. Notably, we left out the actual functionality of `patch`, as the relevant code makes up more than half of `git-add--interactive.perl`, and is actually pretty independent of the rest of the commands. With this commit, we start to tackle that `patch` part. For better separation of concerns, we keep the code in a separate file, `add-patch.c`. The new code is still guarded behind the `add.interactive.useBuiltin` config setting, and for the moment, it can only be called via `git add -p`. The actual functionality follows the original implementation of 5cde71d64aff (git-add --interactive, 2006-12-10), but not too closely (for example, we use string offsets rather than copying strings around, and after seeing whether the `k` and `j` commands are applicable, in the C version we remember which previous/next hunk was undecided, and use it rather than looking again when the user asked to jump). As a further deviation from that commit, We also use a comma instead of a slash to separate the available commands in the prompt, as the current version of the Perl script does this, and we also add a line about the question mark ("print help") to the help text. While it is tempting to use this conversion of `git add -p` as an excuse to work on `apply_all_patches()` so that it does _not_ want to read a file from `stdin` or from a file, but accepts, say, an `strbuf` instead, we will refrain from this particular rabbit hole at this stage. Signed-off-by: Johannes Schindelin Signed-off-by: Junio C Hamano --- add-patch.c | 265 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 265 insertions(+) create mode 100644 add-patch.c (limited to 'add-patch.c') diff --git a/add-patch.c b/add-patch.c new file mode 100644 index 0000000000..d1b1a080e4 --- /dev/null +++ b/add-patch.c @@ -0,0 +1,265 @@ +#include "cache.h" +#include "add-interactive.h" +#include "strbuf.h" +#include "run-command.h" +#include "argv-array.h" +#include "pathspec.h" + +struct hunk { + size_t start, end; + enum { UNDECIDED_HUNK = 0, SKIP_HUNK, USE_HUNK } use; +}; + +struct add_p_state { + struct repository *r; + struct strbuf answer, buf; + + /* parsed diff */ + struct strbuf plain; + struct hunk head; + struct hunk *hunk; + size_t hunk_nr, hunk_alloc; +}; + +static void setup_child_process(struct add_p_state *s, + struct child_process *cp, ...) +{ + va_list ap; + const char *arg; + + va_start(ap, cp); + while ((arg = va_arg(ap, const char *))) + argv_array_push(&cp->args, arg); + va_end(ap); + + cp->git_cmd = 1; + argv_array_pushf(&cp->env_array, + INDEX_ENVIRONMENT "=%s", s->r->index_file); +} + +static int parse_diff(struct add_p_state *s, const struct pathspec *ps) +{ + struct strbuf *plain = &s->plain; + struct child_process cp = CHILD_PROCESS_INIT; + char *p, *pend; + size_t i; + struct hunk *hunk = NULL; + int res; + + /* Use `--no-color` explicitly, just in case `diff.color = always`. */ + setup_child_process(s, &cp, + "diff-files", "-p", "--no-color", "--", NULL); + for (i = 0; i < ps->nr; i++) + argv_array_push(&cp.args, ps->items[i].original); + + res = capture_command(&cp, plain, 0); + if (res) + return error(_("could not parse diff")); + if (!plain->len) + return 0; + strbuf_complete_line(plain); + + /* parse hunks */ + p = plain->buf; + pend = p + plain->len; + while (p != pend) { + char *eol = memchr(p, '\n', pend - p); + if (!eol) + eol = pend; + + if (starts_with(p, "diff ")) { + if (p != plain->buf) + BUG("multi-file diff not yet handled"); + hunk = &s->head; + } else if (p == plain->buf) + BUG("diff starts with unexpected line:\n" + "%.*s\n", (int)(eol - p), p); + else if (starts_with(p, "@@ ")) { + s->hunk_nr++; + ALLOC_GROW(s->hunk, s->hunk_nr, + s->hunk_alloc); + hunk = s->hunk + s->hunk_nr - 1; + memset(hunk, 0, sizeof(*hunk)); + + hunk->start = p - plain->buf; + } + + p = eol == pend ? pend : eol + 1; + hunk->end = p - plain->buf; + } + + return 0; +} + +static void render_hunk(struct add_p_state *s, struct hunk *hunk, + struct strbuf *out) +{ + strbuf_add(out, s->plain.buf + hunk->start, + hunk->end - hunk->start); +} + +static void reassemble_patch(struct add_p_state *s, struct strbuf *out) +{ + struct hunk *hunk; + size_t i; + + render_hunk(s, &s->head, out); + + for (i = 0; i < s->hunk_nr; i++) { + hunk = s->hunk + i; + if (hunk->use == USE_HUNK) + render_hunk(s, hunk, out); + } +} + +static const char help_patch_text[] = +N_("y - stage this hunk\n" + "n - do not stage this hunk\n" + "a - stage this and all the remaining hunks\n" + "d - do not stage this hunk nor any of the remaining hunks\n" + "j - leave this hunk undecided, see next undecided hunk\n" + "J - leave this hunk undecided, see next hunk\n" + "k - leave this hunk undecided, see previous undecided hunk\n" + "K - leave this hunk undecided, see previous hunk\n" + "? - print help\n"); + +static int patch_update_file(struct add_p_state *s) +{ + size_t hunk_index = 0; + ssize_t i, undecided_previous, undecided_next; + struct hunk *hunk; + char ch; + struct child_process cp = CHILD_PROCESS_INIT; + + if (!s->hunk_nr) + return 0; + + strbuf_reset(&s->buf); + render_hunk(s, &s->head, &s->buf); + fputs(s->buf.buf, stdout); + for (;;) { + if (hunk_index >= s->hunk_nr) + hunk_index = 0; + hunk = s->hunk + hunk_index; + + undecided_previous = -1; + for (i = hunk_index - 1; i >= 0; i--) + if (s->hunk[i].use == UNDECIDED_HUNK) { + undecided_previous = i; + break; + } + + undecided_next = -1; + for (i = hunk_index + 1; i < s->hunk_nr; i++) + if (s->hunk[i].use == UNDECIDED_HUNK) { + undecided_next = i; + break; + } + + /* Everything decided? */ + if (undecided_previous < 0 && undecided_next < 0 && + hunk->use != UNDECIDED_HUNK) + break; + + strbuf_reset(&s->buf); + render_hunk(s, hunk, &s->buf); + fputs(s->buf.buf, stdout); + + strbuf_reset(&s->buf); + if (undecided_previous >= 0) + strbuf_addstr(&s->buf, ",k"); + if (hunk_index) + strbuf_addstr(&s->buf, ",K"); + if (undecided_next >= 0) + strbuf_addstr(&s->buf, ",j"); + if (hunk_index + 1 < s->hunk_nr) + strbuf_addstr(&s->buf, ",J"); + printf("(%"PRIuMAX"/%"PRIuMAX") ", + (uintmax_t)hunk_index + 1, (uintmax_t)s->hunk_nr); + printf(_("Stage this hunk [y,n,a,d%s,?]? "), s->buf.buf); + fflush(stdout); + if (strbuf_getline(&s->answer, stdin) == EOF) + break; + strbuf_trim_trailing_newline(&s->answer); + + if (!s->answer.len) + continue; + ch = tolower(s->answer.buf[0]); + if (ch == 'y') { + hunk->use = USE_HUNK; +soft_increment: + hunk_index = undecided_next < 0 ? + s->hunk_nr : undecided_next; + } else if (ch == 'n') { + hunk->use = SKIP_HUNK; + goto soft_increment; + } else if (ch == 'a') { + for (; hunk_index < s->hunk_nr; hunk_index++) { + hunk = s->hunk + hunk_index; + if (hunk->use == UNDECIDED_HUNK) + hunk->use = USE_HUNK; + } + } else if (ch == 'd') { + for (; hunk_index < s->hunk_nr; hunk_index++) { + hunk = s->hunk + hunk_index; + if (hunk->use == UNDECIDED_HUNK) + hunk->use = SKIP_HUNK; + } + } else if (hunk_index && s->answer.buf[0] == 'K') + hunk_index--; + else if (hunk_index + 1 < s->hunk_nr && + s->answer.buf[0] == 'J') + hunk_index++; + else if (undecided_previous >= 0 && + s->answer.buf[0] == 'k') + hunk_index = undecided_previous; + else if (undecided_next >= 0 && s->answer.buf[0] == 'j') + hunk_index = undecided_next; + else + puts(_(help_patch_text)); + } + + /* Any hunk to be used? */ + for (i = 0; i < s->hunk_nr; i++) + if (s->hunk[i].use == USE_HUNK) + break; + + if (i < s->hunk_nr) { + /* At least one hunk selected: apply */ + strbuf_reset(&s->buf); + reassemble_patch(s, &s->buf); + + discard_index(s->r->index); + setup_child_process(s, &cp, "apply", "--cached", NULL); + if (pipe_command(&cp, s->buf.buf, s->buf.len, + NULL, 0, NULL, 0)) + error(_("'git apply --cached' failed")); + if (!repo_read_index(s->r)) + repo_refresh_and_write_index(s->r, REFRESH_QUIET, 0, + 1, NULL, NULL, NULL); + } + + putchar('\n'); + return 0; +} + +int run_add_p(struct repository *r, const struct pathspec *ps) +{ + struct add_p_state s = { r, STRBUF_INIT, STRBUF_INIT, STRBUF_INIT }; + + if (discard_index(r->index) < 0 || repo_read_index(r) < 0 || + repo_refresh_and_write_index(r, REFRESH_QUIET, 0, 1, + NULL, NULL, NULL) < 0 || + parse_diff(&s, ps) < 0) { + strbuf_release(&s.plain); + return -1; + } + + if (s.hunk_nr) + patch_update_file(&s); + + strbuf_release(&s.answer); + strbuf_release(&s.buf); + strbuf_release(&s.plain); + return 0; +} -- cgit v1.2.3