# [PATCH] parse-options: fix clang opterror() -Wunused-value warning

2 messages from 2013-08-09 to 2013-08-09. Participants: Eric Sunshine, Jeff King.
Thread: https://gitlist.dev/t/34651

## Eric Sunshine, 2013-08-09 09:06

Subject: [PATCH] parse-options: fix clang opterror() -Wunused-value warning
Message-ID: <1376039177-17560-1-git-send-email-sunshine@sunshineco.com>
URL: https://gitlist.dev/e/1376039177-17560-1-git-send-email-sunshine%40sunshineco.com

```
a469a1019352b8ef (silence some -Wuninitialized false positives;
2012-12-15) triggered "unused value" warnings when the return value of
opterror() and several other error-related functions was not used.
5ded807f7c0be10e (fix clang -Wunused-value warnings for error functions;
2013-01-16) applied a fix by adding #if !defined(__clang__) in cache.h
and git-compat-util.h, but misspelled it as #if !defined(clang) in
parse-options.h. Fix this.

This mistake went unnoticed because existing callers of opterror()
utilize its return value.  1158826394e162c5 (parse-options: add
OPT_CMDMODE(); 2013-07-30), however, adds a new invocation of opterror()
which ignores the return value, thus triggering the "unused value"
warning.

Signed-off-by: Eric Sunshine <sunshine@sunshineco.com>
---
 parse-options.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/parse-options.h b/parse-options.h
index aeab9aa..8736006 100644
--- a/parse-options.h
+++ b/parse-options.h
@@ -182,7 +182,7 @@ extern NORETURN void usage_msg_opt(const char *msg,
 
 extern int optbug(const struct option *opt, const char *reason);
 extern int opterror(const struct option *opt, const char *reason, int flags);
-#if defined(__GNUC__) && ! defined(clang)
+#if defined(__GNUC__) && ! defined(__clang__)
 #define opterror(o,r,f) (opterror((o),(r),(f)), -1)
 #endif
 
-- 
1.8.4.rc1.428.gcd48621

```

## Jeff King, 2013-08-09 10:32

Subject: Re: [PATCH] parse-options: fix clang opterror() -Wunused-value warning
Message-ID: <20130809103249.GA18878@sigill.intra.peff.net>
URL: https://gitlist.dev/e/20130809103249.GA18878%40sigill.intra.peff.net
In-Reply-To: <1376039177-17560-1-git-send-email-sunshine@sunshineco.com>

```
On Fri, Aug 09, 2013 at 05:06:17AM -0400, Eric Sunshine wrote:

> a469a1019352b8ef (silence some -Wuninitialized false positives;
> 2012-12-15) triggered "unused value" warnings when the return value of
> opterror() and several other error-related functions was not used.
> 5ded807f7c0be10e (fix clang -Wunused-value warnings for error functions;
> 2013-01-16) applied a fix by adding #if !defined(__clang__) in cache.h
> and git-compat-util.h, but misspelled it as #if !defined(clang) in
> parse-options.h. Fix this.
> 
> This mistake went unnoticed because existing callers of opterror()
> utilize its return value.  1158826394e162c5 (parse-options: add
> OPT_CMDMODE(); 2013-07-30), however, adds a new invocation of opterror()
> which ignores the return value, thus triggering the "unused value"
> warning.

Oops.

Patch looks obviously correct. Thanks for a nice explanation of what
happened.

-Peff

```