git/list[1] front-page[2] threads[3] people[4] search[5] about
 

Re: [PATCH] parse-options: detect attempt to add a duplicate short option name

From
Junio C Hamano <gitster@pobox.com>
Date
Sep 3, 2014, 21:05 UTC
Message-ID
<xmqqoauwwh2c.fsf@gitster.dls.corp.google.com>
In-Reply-To
<54077A3E.20703@web.de>
René Scharfe <l.s.r@web.de> writes:
> Compact and useful, I like it.
>
> You might want to squash in something like this, though.  Without it
> t1502 fails because -b is defined twice there.

Thanks. I like it to see that the check automatically propagates even to scripts ;-)

It bugged me enough that we didn't identify which short option letter we were complaining about and that opts->short_name is defined as an "int", which may cause us to overstep char[128], I ended up doing it this way instead, though. It no longer is so compact, even though it may still have the same usefulness.

We might want to tighten the type of the short_name member to unsigned char, but I didn't go that far yet, at least in this step.

-- >8 --
Subject: [PATCH] parse-options: detect attempt to add a duplicate short option name

It is easy to overlook an already assigned single-letter option name and try to use it for a new one. Help the developer to catch it before such a mistake escapes the lab.

Helped-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 parse-options.c               | 15 +++++++++++++++
 t/t1502-rev-parse-parseopt.sh |  4 ++--
 2 files changed, 17 insertions(+), 2 deletions(-)
diff --git a/parse-options.c b/parse-options.c
index b536896..70227e9 100644
--- a/parse-options.c
+++ b/parse-options.c
@@ -345,12 +345,27 @@ static void check_typos(const char *arg, const struct option *options)
 static void parse_options_check(const struct option *opts)
 {
 	int err = 0;
+	char short_opts[128];
+
+	memset(short_opts, '\0', sizeof(short_opts));
 
 	for (; opts->type != OPTION_END; opts++) {
 		if ((opts->flags & PARSE_OPT_LASTARG_DEFAULT) &&
 		    (opts->flags & PARSE_OPT_OPTARG))
 			err |= optbug(opts, "uses incompatible flags "
 					"LASTARG_DEFAULT and OPTARG");
+		if (opts->short_name) {
+			struct strbuf errmsg = STRBUF_INIT;
+			if (opts->short_name < ' ' || 0x7F <= opts->short_name)
+				strbuf_addf(&errmsg, "invalid short name (0x%02x)",
+					    opts->short_name);
+			else if (short_opts[opts->short_name]++)
+				strbuf_addf(&errmsg, "short name %c already used",
+					    opts->short_name);
+			if (errmsg.len)
+				err |= optbug(opts, errmsg.buf);
+			strbuf_release(&errmsg);
+		}
 		if (opts->flags & PARSE_OPT_NODASH &&
 		    ((opts->flags & PARSE_OPT_OPTARG) ||
 		     !(opts->flags & PARSE_OPT_NOARG) ||
diff --git a/t/t1502-rev-parse-parseopt.sh b/t/t1502-rev-parse-parseopt.sh
index 922423e..ebe7c3b 100755
--- a/t/t1502-rev-parse-parseopt.sh
+++ b/t/t1502-rev-parse-parseopt.sh
@@ -19,7 +19,7 @@ sed -e 's/^|//' >expect <<\END_EXPECT
 |    -d, --data[=...]      short and long option with an optional argument
 |
 |Argument hints
-|    -b <arg>              short option required argument
+|    -B <arg>              short option required argument
 |    --bar2 <arg>          long option required argument
 |    -e, --fuz <with-space>
 |                          short and long option required argument
@@ -51,7 +51,7 @@ sed -e 's/^|//' >optionspec <<\EOF
 |d,data?   short and long option with an optional argument
 |
 | Argument hints
-|b=arg     short option required argument
+|B=arg     short option required argument
 |bar2=arg  long option required argument
 |e,fuz=with-space  short and long option required argument
 |s?some    short option optional argument
-- 
2.1.0-394-g3e31896
Previous: René ScharfeNext: René Scharfe
Message 8 of 20 in “Teach revert/cherry-pick the --no-verify option”
  1. 0/3 Teach revert/cherry-pick the --no-verify optionJohan Herland, Sep 3, 2014
  2. 1/3 t7503/4: Add failing testcases for revert/cherry-pick --no-verifyJohan Herland, Sep 3, 2014
  3. Junio C HamanoSep 3, 2014
  4. 2/3 revert/cherry-pick: Add --no-verify option, and pass it on to commitJohan Herland, Sep 3, 2014
  5. Junio C HamanoSep 3, 2014
  6. parse-options: detect attempt to add a duplicate short option nameJunio C Hamano, Sep 3, 2014
  7. René ScharfeSep 3, 2014
  8. Junio C HamanoSep 3, 2014
  9. René ScharfeSep 3, 2014
  10. Junio C HamanoSep 3, 2014
  11. René ScharfeSep 4, 2014
  12. Junio C HamanoSep 4, 2014
  13. Junio C HamanoSep 4, 2014
  14. Jonathan NiederSep 3, 2014
  15. Jonathan NiederSep 3, 2014
  16. Johan HerlandSep 4, 2014
  17. 3/3 revert/cherry-pick --no-verify: Update documentationJohan Herland, Sep 3, 2014
  18. Junio C HamanoSep 3, 2014
  19. Fabian RuchSep 5, 2014
  20. Johan HerlandSep 8, 2014

Read the whole thread, see it on lore, or plain text.

$ cat FOOTERMessages come from the public archive at lore.kernel.org/git, fetched every hour. The front page is chosen and written each morning by an AI editor and can be wrong; the threads themselves are the record. About and API. For agents: an MCP server at https://gitlist.dev/mcp, and any thread, story or person page as Markdown by adding .md to its URL (or sending Accept: text/markdown). Details in /llms.txt.