git.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: "René Scharfe" <l.s.r@web.de>
To: Johannes Schindelin <johannes.schindelin@gmx.de>, git@vger.kernel.org
Cc: Junio C Hamano <gitster@pobox.com>
Subject: Re: [PATCH 2/2] nedmalloc: work around overzealous GCC 6 warning
Date: Thu, 4 Aug 2016 23:56:54 +0200	[thread overview]
Message-ID: <57A3BA26.5080601@web.de> (raw)
In-Reply-To: <57360f4885bdd5c36e190bea288f1e1f7f706071.1470326812.git.johannes.schindelin@gmx.de>

Am 04.08.2016 um 18:07 schrieb Johannes Schindelin:
> With GCC 6, the strdup() function is declared with the "nonnull"
> attribute, stating that it is not allowed to pass a NULL value as
> parameter.
>
> In nedmalloc()'s reimplementation of strdup(), Postel's Law is heeded
> and NULL parameters are handled gracefully. GCC 6 complains about that
> now because it thinks that NULL cannot be passed to strdup() anyway.
>
> Let's just shut up GCC >= 6 in that case and go on with our lives.

This version of strdup() is only compiled if nedmalloc is used instead
of the system allocator.  That means we can't rely on strdup() being
able to take NULL -- some (most?) platforms won't like it.  Removing
the NULL check would be a more general and overall easier way out, no?

But it should check the result of malloc() before copying.
---
  compat/nedmalloc/nedmalloc.c | 8 +++-----
  1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/compat/nedmalloc/nedmalloc.c b/compat/nedmalloc/nedmalloc.c
index a0a16eb..cc18f0c 100644
--- a/compat/nedmalloc/nedmalloc.c
+++ b/compat/nedmalloc/nedmalloc.c
@@ -955,12 +955,10 @@ void **nedpindependent_comalloc(nedpool *p, size_t 
elems, size_t *sizes, void **
   */
  char *strdup(const char *s1)
  {
-	char *s2 = 0;
-	if (s1) {
-		size_t len = strlen(s1) + 1;
-		s2 = malloc(len);
+	size_t len = strlen(s1) + 1;
+	char *s2 = malloc(len);
+	if (s2)
  		memcpy(s2, s1, len);
-	}
  	return s2;
  }
  #endif
-- 
2.9.2


  parent reply	other threads:[~2016-08-04 21:57 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-08-04 16:07 [PATCH 0/2] Patches to let Git build with GCC 6 and DEVELOPER=SureWhyNot Johannes Schindelin
2016-08-04 16:07 ` [PATCH 1/2] nedmalloc: fix misleading indentation Johannes Schindelin
2016-08-04 16:07 ` [PATCH 2/2] nedmalloc: work around overzealous GCC 6 warning Johannes Schindelin
2016-08-04 17:41   ` Junio C Hamano
2016-08-05 15:38     ` Johannes Schindelin
2016-08-04 21:56   ` René Scharfe [this message]
2016-08-04 22:33     ` Junio C Hamano
2016-08-04 22:39     ` Junio C Hamano
2016-08-05  5:36       ` Johannes Sixt
2016-08-05  5:40         ` Johannes Sixt
2016-08-05  6:24           ` Junio C Hamano
2016-08-05  7:42             ` Jeff King
2016-08-05 15:34       ` Johannes Schindelin
2016-08-05 16:13         ` Junio C Hamano
2016-08-06  8:19           ` Johannes Schindelin
2016-08-05 21:57         ` Junio C Hamano
2016-08-05 22:30           ` René Scharfe

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=57A3BA26.5080601@web.de \
    --to=l.s.r@web.de \
    --cc=git@vger.kernel.org \
    --cc=gitster@pobox.com \
    --cc=johannes.schindelin@gmx.de \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).