| Message ID | 20210924155000.1259649-1-someguy@effective-light.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [v8,1/2] grep: refactor next_match() and match_one_pattern() for external use | expand |
Hamza Mahfooz <someguy@effective-light.com> writes: > These changes are made in preparation of, the colorization support for the > "git log" subcommands that, rely on regex functionality (i.e. "--author", > "--committer" and "--grep"). These changes are necessary primarily because > match_one_pattern() expects header lines to be prefixed, however, in > pretty, the prefixes are stripped from the lines because the name-email > pairs need to go through additional parsing, before they can be printed and > because next_match() doesn't handle the case of > "ctx == GREP_CONTEXT_HEAD" at all. So, teach next_match() how to handle the > new case and move match_one_pattern()'s core logic to > headless_match_one_pattern() while preserving match_one_pattern()'s uses > that depend on the additional processing. > > Signed-off-by: Hamza Mahfooz <someguy@effective-light.com> > --- > v5: separate grep changes from pretty changes. > > v6: rescope some variables. > > v7: export header_field[] and allow for subsequent matches on header lines > in match_one_pattern(). > > v8: add headless_match_one_pattern() and move header_field[] back. This looks a lot more sensible split compared to the previous round. > --- > grep.c | 83 ++++++++++++++++++++++++++++++++++++---------------------- > grep.h | 4 +++ > 2 files changed, 55 insertions(+), 32 deletions(-) > > diff --git a/grep.c b/grep.c > index 14fe8a0fd2..e46b046638 100644 > --- a/grep.c > +++ b/grep.c > @@ -944,37 +944,19 @@ static struct { > { "reflog ", 7 }, > }; > > -static int match_one_pattern(struct grep_pat *p, > - const char *bol, const char *eol, > - enum grep_context ctx, > - regmatch_t *pmatch, int eflags) > +static int headerless_match_one_pattern(struct grep_pat *p, > + const char *bol, const char *eol, > + enum grep_context ctx, > + regmatch_t *pmatch, int eflags) > { > int hit = 0; > const char *start = bol; > > if ((p->token != GREP_PATTERN) && > - ((p->token == GREP_PATTERN_HEAD) != (ctx == GREP_CONTEXT_HEAD))) > + ((p->token == GREP_PATTERN_HEAD) != (ctx == GREP_CONTEXT_HEAD)) && > + ((p->token == GREP_PATTERN_BODY) != (ctx == GREP_CONTEXT_BODY))) I _think_ it makes sense to have this additional "if looking for something in the body, do not bother if we are not in body", but I wonder if that is a bugfix that has nothing to do with this topic. In other words, even if for whatever reason we decide that it is not worth painting the hits in "git log --grep=<pattern> --author=<who>" output, would the addition to this single condition to the original code, with or without the refactoring, fix some existing bug? If so, perhaps that can be a separate patch with a test that demonstrates the bug fixed. With this change mixed in, it is unclear if this step is pure refactoring that does not break the existing callers of the code path. If it is not a bugfix, we need to explain the reason why this additional condition is necessary in the proposed log message (I am assuming that this change is needed to get the end result working). > +static int match_one_pattern(struct grep_pat *p, > + const char *bol, const char *eol, > + enum grep_context ctx, regmatch_t *pmatch, > + int eflags) > +{ > + const char *field; > + size_t len; > + > + if (p->token == GREP_PATTERN_HEAD) { > + assert(p->field < ARRAY_SIZE(header_field)); > + field = header_field[p->field].field; > + len = header_field[p->field].len; > + if (strncmp(bol, field, len)) > + return 0; > + bol += len; > + > + switch (p->field) { > + case GREP_HEADER_AUTHOR: > + case GREP_HEADER_COMMITTER: > + strip_timestamp(bol, &eol); > + break; > + default: > + break; > + } > + } > + > + return headerless_match_one_pattern(p, bol, eol, ctx, pmatch, eflags); > +} So, match_one_pattern() after all the above changes behaves almost identically for existing callers, except that it has the "pattern for body should only apply to the body text" condition added, which may affect the behaviour. > @@ -1143,7 +1155,7 @@ static int match_next_pattern(struct grep_pat *p, > { > regmatch_t match; > > - if (!match_one_pattern(p, bol, eol, ctx, &match, eflags)) > + if (!headerless_match_one_pattern(p, bol, eol, ctx, &match, eflags)) > return 0; > if (match.rm_so < 0 || match.rm_eo < 0) > return 0; Since this "next" thing is designed to be repeatedly called, we use the new helper that is meant for <bol, eol> after we preprocessed the header and the trailing timestamp away, which makes sense, I guess. But the caller needs to do the preprocessing before it makes the first call to match_next_pattern() on any given line to adjust bol and eol. > @@ -1158,22 +1170,28 @@ static int match_next_pattern(struct grep_pat *p, > return 1; > } > > -static int next_match(struct grep_opt *opt, > - const char *bol, const char *eol, > - enum grep_context ctx, regmatch_t *pmatch, int eflags) > +int grep_next_match(struct grep_opt *opt, > + const char *bol, const char *eol, > + enum grep_context ctx, regmatch_t *pmatch, > + enum grep_header_field field, int eflags) > { > struct grep_pat *p; > int hit = 0; > > pmatch->rm_so = pmatch->rm_eo = -1; > if (bol < eol) { > - for (p = opt->pattern_list; p; p = p->next) { > + for (p = ((ctx == GREP_CONTEXT_HEAD) > + ? opt->header_list : opt->pattern_list); > + p; p = p->next) { > switch (p->token) { > case GREP_PATTERN: /* atom */ > case GREP_PATTERN_HEAD: > case GREP_PATTERN_BODY: > - hit |= match_next_pattern(p, bol, eol, ctx, > - pmatch, eflags); > + if ((field == GREP_HEADER_FIELD_MAX) || > + (p->field == field)) > + hit |= match_next_pattern(p, bol, eol, > + ctx, pmatch, > + eflags); ... and this caller apparently does not. It is made the responsibility of the callers of grep_next_match() to adjust bol and eol before calling it. > break; > default: > break; > @@ -1261,7 +1279,8 @@ static void show_line(struct grep_opt *opt, > else if (sign == '=') > line_color = opt->colors[GREP_COLOR_FUNCTION]; > } > - while (next_match(opt, bol, eol, ctx, &match, eflags)) { > + while (grep_next_match(opt, bol, eol, ctx, &match, > + GREP_HEADER_FIELD_MAX, eflags)) { ... which is this caller, show_line(), which is the only caller of grep_next_match(). But this function is not taught to strip headers and timestamp from <bol, eol>, either, so it is the responsibility of the callers of show_line(). I _think_ all the current callers of show_line() handle the blob contents found by "git grep" and not "git log --grep/--author", and there is no GREP_PATTERN_HEAD/GREP_PATTERN_BODY given, but I may be mistaken. With the current set of callers, do we ever call next_match() with a pattern with p->token set to GREP_PATTERN_HEAD or _BODY? I am wondering why we even have those cases covered in the switch statement in the previous hunk. match_one_pattern() of course must be prepared to see the HEAD and BODY requests because match_expr_eval() is evantually called via grep_buffer() interface to implement "git log --grep/--author", but I do not think next_match() would be called in that code path. The handling of GREP_PATTERN_HEAD and GREP_PATTERN_BODY in next_match(), which I am wondering about, came from 7e8f59d5 (grep: color patterns in output, 2009-03-07). Anyway, let's read on. > diff --git a/grep.h b/grep.h > index 3cb8a83ae8..521068308e 100644 > --- a/grep.h > +++ b/grep.h > @@ -190,6 +190,10 @@ void append_header_grep_pattern(struct grep_opt *, enum grep_header_field, const > void compile_grep_patterns(struct grep_opt *opt); > void free_grep_patterns(struct grep_opt *opt); > int grep_buffer(struct grep_opt *opt, const char *buf, unsigned long size); > +int grep_next_match(struct grep_opt *opt, > + const char *bol, const char *eol, > + enum grep_context ctx, regmatch_t *pmatch, > + enum grep_header_field field, int eflags); As this is made external, it at least needs a comment on the (somewhat strange) field parameter, especially the fact that "no, this is not grepping in the header lines in a commit object" is signalled by a special GREP_HEADER_FIELD_MAX value. > > struct grep_source { > char *name; Other than that, looks much cleaner than the previous round. Thanks.
diff --git a/grep.c b/grep.c index 14fe8a0fd2..e46b046638 100644 --- a/grep.c +++ b/grep.c @@ -944,37 +944,19 @@ static struct { { "reflog ", 7 }, }; -static int match_one_pattern(struct grep_pat *p, - const char *bol, const char *eol, - enum grep_context ctx, - regmatch_t *pmatch, int eflags) +static int headerless_match_one_pattern(struct grep_pat *p, + const char *bol, const char *eol, + enum grep_context ctx, + regmatch_t *pmatch, int eflags) { int hit = 0; const char *start = bol; if ((p->token != GREP_PATTERN) && - ((p->token == GREP_PATTERN_HEAD) != (ctx == GREP_CONTEXT_HEAD))) + ((p->token == GREP_PATTERN_HEAD) != (ctx == GREP_CONTEXT_HEAD)) && + ((p->token == GREP_PATTERN_BODY) != (ctx == GREP_CONTEXT_BODY))) return 0; - if (p->token == GREP_PATTERN_HEAD) { - const char *field; - size_t len; - assert(p->field < ARRAY_SIZE(header_field)); - field = header_field[p->field].field; - len = header_field[p->field].len; - if (strncmp(bol, field, len)) - return 0; - bol += len; - switch (p->field) { - case GREP_HEADER_AUTHOR: - case GREP_HEADER_COMMITTER: - strip_timestamp(bol, &eol); - break; - default: - break; - } - } - again: hit = patmatch(p, bol, eol, pmatch, eflags); @@ -1025,6 +1007,36 @@ static int match_one_pattern(struct grep_pat *p, return hit; } +static int match_one_pattern(struct grep_pat *p, + const char *bol, const char *eol, + enum grep_context ctx, regmatch_t *pmatch, + int eflags) +{ + const char *field; + size_t len; + + if (p->token == GREP_PATTERN_HEAD) { + assert(p->field < ARRAY_SIZE(header_field)); + field = header_field[p->field].field; + len = header_field[p->field].len; + if (strncmp(bol, field, len)) + return 0; + bol += len; + + switch (p->field) { + case GREP_HEADER_AUTHOR: + case GREP_HEADER_COMMITTER: + strip_timestamp(bol, &eol); + break; + default: + break; + } + } + + return headerless_match_one_pattern(p, bol, eol, ctx, pmatch, eflags); +} + + static int match_expr_eval(struct grep_opt *opt, struct grep_expr *x, const char *bol, const char *eol, enum grep_context ctx, ssize_t *col, @@ -1143,7 +1155,7 @@ static int match_next_pattern(struct grep_pat *p, { regmatch_t match; - if (!match_one_pattern(p, bol, eol, ctx, &match, eflags)) + if (!headerless_match_one_pattern(p, bol, eol, ctx, &match, eflags)) return 0; if (match.rm_so < 0 || match.rm_eo < 0) return 0; @@ -1158,22 +1170,28 @@ static int match_next_pattern(struct grep_pat *p, return 1; } -static int next_match(struct grep_opt *opt, - const char *bol, const char *eol, - enum grep_context ctx, regmatch_t *pmatch, int eflags) +int grep_next_match(struct grep_opt *opt, + const char *bol, const char *eol, + enum grep_context ctx, regmatch_t *pmatch, + enum grep_header_field field, int eflags) { struct grep_pat *p; int hit = 0; pmatch->rm_so = pmatch->rm_eo = -1; if (bol < eol) { - for (p = opt->pattern_list; p; p = p->next) { + for (p = ((ctx == GREP_CONTEXT_HEAD) + ? opt->header_list : opt->pattern_list); + p; p = p->next) { switch (p->token) { case GREP_PATTERN: /* atom */ case GREP_PATTERN_HEAD: case GREP_PATTERN_BODY: - hit |= match_next_pattern(p, bol, eol, ctx, - pmatch, eflags); + if ((field == GREP_HEADER_FIELD_MAX) || + (p->field == field)) + hit |= match_next_pattern(p, bol, eol, + ctx, pmatch, + eflags); break; default: break; @@ -1261,7 +1279,8 @@ static void show_line(struct grep_opt *opt, else if (sign == '=') line_color = opt->colors[GREP_COLOR_FUNCTION]; } - while (next_match(opt, bol, eol, ctx, &match, eflags)) { + while (grep_next_match(opt, bol, eol, ctx, &match, + GREP_HEADER_FIELD_MAX, eflags)) { if (match.rm_so == match.rm_eo) break; diff --git a/grep.h b/grep.h index 3cb8a83ae8..521068308e 100644 --- a/grep.h +++ b/grep.h @@ -190,6 +190,10 @@ void append_header_grep_pattern(struct grep_opt *, enum grep_header_field, const void compile_grep_patterns(struct grep_opt *opt); void free_grep_patterns(struct grep_opt *opt); int grep_buffer(struct grep_opt *opt, const char *buf, unsigned long size); +int grep_next_match(struct grep_opt *opt, + const char *bol, const char *eol, + enum grep_context ctx, regmatch_t *pmatch, + enum grep_header_field field, int eflags); struct grep_source { char *name;
These changes are made in preparation of, the colorization support for the "git log" subcommands that, rely on regex functionality (i.e. "--author", "--committer" and "--grep"). These changes are necessary primarily because match_one_pattern() expects header lines to be prefixed, however, in pretty, the prefixes are stripped from the lines because the name-email pairs need to go through additional parsing, before they can be printed and because next_match() doesn't handle the case of "ctx == GREP_CONTEXT_HEAD" at all. So, teach next_match() how to handle the new case and move match_one_pattern()'s core logic to headless_match_one_pattern() while preserving match_one_pattern()'s uses that depend on the additional processing. Signed-off-by: Hamza Mahfooz <someguy@effective-light.com> --- v5: separate grep changes from pretty changes. v6: rescope some variables. v7: export header_field[] and allow for subsequent matches on header lines in match_one_pattern(). v8: add headless_match_one_pattern() and move header_field[] back. --- grep.c | 83 ++++++++++++++++++++++++++++++++++++---------------------- grep.h | 4 +++ 2 files changed, 55 insertions(+), 32 deletions(-)