Re: [PATCH v2] grep: improve errors for unmatched ( and )
From: Junio C Hamano <hidden>
Date: 2024-03-23 18:07:01
Possibly related (same subject, not in this thread)
- 2024-03-23 · [PATCH v2] grep: improve errors for unmatched ( and ) · Ahelenia Ziemiańska <hidden>
Ahelenia Ziemiańska [off-list ref] writes:
Imagine you want to grep for (. Easy: $ git grep '(' fatal: unmatched parenthesis uhoh. This is plainly wrong. Unless you know specifically that (a) git grep has expression groups and that (b) the only way to work around them is by doing -- '(' or -e '(' Similarly, $ git grep ')' fatal: incomplete pattern expression: ) is somehow worse. ")" is a complete regular expression pattern. Of course, the error wants to say "group" here. In this case it's also not "incomplete", it's unmatched. But whatever. Make them return $ ./git grep '(' fatal: unmatched ( for expression group $ ./git grep ')' fatal: incomplete pattern expression group: ) which hopefully are clearer in indicating that it's not the expression that's wrong (since no pattern had been parsed at all), but rather that it's been misconstrued as a grouping operator. Link: https://bugs.debian.org/1051205 Signed-off-by: Ahelenia Ziemiańska <redacted> --- On Fri, Mar 22, 2024 at 09:41:40AM -0700, Junio C Hamano wrote:quoted
Ahelenia Ziemiańska [off-list ref] writes:quoted
uhoh. This is plainly wrong. Unless you know specifically that (a) git grep has expression groups and that (b) the only way to work around them is by doing -- '(' or -e '('I do not think "--" (end of options and beginning of pathspec) marker would work for that purpose, UNLESS you are talking about a file whose name is an open parenthesis.False. -- turns all subsequent parameters into arguments, and if there is no -e, the first argument is the pattern, and all the subsequent ones are paths. This is normal [git] grep behaviour.
Ah, thanks. I forgot that "git grep" was a oddball that allows revs come after "--" in some cases. As long as the user understands this may not work for other commands, it is OK. "-e" is the only officially supported way (which is why I mentioned it in the review comments I gave you here), so guiding users in that direction would be a better idea anyway, though. Thanks.
quoted hunk
diff --git a/grep.c b/grep.c index 5f23d1a..ac34bfe 100644 --- a/grep.c +++ b/grep.c@@ -621,7 +621,7 @@ static struct grep_expr *compile_pattern_atom(struct grep_pat **list) *list = p->next; x = compile_pattern_or(list); if (!*list || (*list)->token != GREP_CLOSE_PAREN) - die("unmatched parenthesis"); + die("unmatched ( for expression group"); *list = (*list)->next; return x; default:@@ -792,7 +792,7 @@ void compile_grep_patterns(struct grep_opt *opt) if (p) opt->pattern_expression = compile_pattern_expr(&p); if (p) - die("incomplete pattern expression: %s", p->pattern); + die("incomplete pattern expression group: %s", p->pattern); if (opt->no_body_match && opt->pattern_expression) opt->pattern_expression = grep_not_expr(opt->pattern_expression);