From: Junio C Hamano <gitster@pobox.com>
To: Jeff King <peff@peff.net>
Cc: Johannes Sixt <j.sixt@viscovery.net>, git@vger.kernel.org
Subject: Re: [PATCH 8/4] match-trees: drop "x = x" initializations
Date: Fri, 22 Mar 2013 14:33:16 -0700 [thread overview]
Message-ID: <7vtxo35dcz.fsf@alter.siamese.dyndns.org> (raw)
In-Reply-To: <7v1ub76s8c.fsf@alter.siamese.dyndns.org> (Junio C. Hamano's message of "Fri, 22 Mar 2013 14:26:43 -0700")
Junio C Hamano <gitster@pobox.com> writes:
> These three are all updated by the same tree_entry_extract() call,
> and whenever we use mode[12] we use path[12], so if it decides path1
> is used or assigned, it should be able to tell mode1 is, too.
>
> Unsatisfactory, it surely is...
And immediately after I wrote the above, I am greeted by this:
gcc (Debian 4.4.5-8) 4.4.5
match-trees.c:75: error: 'elem1' may be used uninitialized in this function
match-trees.c:77: error: 'path1' may be used uninitialized in this function
and this crazy one on top squelches it.
If you flip the order of four lines that extracts only when size is
non-zero to extract first from two into elem2, then the warning is
given for elem2/path2 but not for elem1/path1.
I'll initialize all of them to nonsense values for now.
diff --git a/match-trees.c b/match-trees.c
index 4360f10..88981e8 100644
--- a/match-trees.c
+++ b/match-trees.c
@@ -72,9 +72,9 @@ static int score_trees(const unsigned char *hash1, const unsigned char *hash2)
die("%s is not a tree", sha1_to_hex(hash2));
init_tree_desc(&two, two_buf, size);
while (one.size || two.size) {
- const unsigned char *elem1;
+ const unsigned char *elem1 = NULL;
const unsigned char *elem2;
- const char *path1;
+ const char *path1 = NULL;
const char *path2;
unsigned mode1 = 0; /* make gcc happy */
unsigned mode2 = 0; /* make gcc happy */
next prev parent reply other threads:[~2013-03-22 21:33 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-03-21 11:03 [PATCH 0/4] drop some "int x = x" hacks to silence gcc warnings Jeff King
2013-03-21 11:05 ` [PATCH 1/4] wt-status: fix possible use of uninitialized variable Jeff King
2013-03-21 19:49 ` Jonathan Nieder
2013-03-21 19:55 ` Junio C Hamano
2013-03-21 19:58 ` Jonathan Nieder
2013-03-22 16:15 ` Jeff King
2013-03-21 11:08 ` [PATCH 2/4] fast-import: use pointer-to-pointer to keep list tail Jeff King
2013-03-21 20:43 ` Jonathan Nieder
2013-03-21 11:10 ` [PATCH 3/4] drop some obsolete "x = x" compiler warning hacks Jeff King
2013-03-21 15:16 ` Erik Faye-Lund
2013-03-21 20:47 ` Jonathan Nieder
2013-03-24 7:17 ` Torsten Bögershausen
2013-03-21 11:13 ` [PATCH 4/4] transport: drop "int cmp = cmp" hack Jeff King
2013-03-21 20:59 ` Jonathan Nieder
2013-03-24 4:00 ` Junio C Hamano
2013-03-24 9:32 ` Jeff King
2013-03-24 14:54 ` Torsten Bögershausen
2013-03-25 19:50 ` Junio C Hamano
2013-03-25 21:06 ` Jeff King
2013-03-25 21:55 ` Junio C Hamano
2013-03-21 11:45 ` [PATCH 0/4] drop some "int x = x" hacks to silence gcc warnings Johannes Sixt
2013-03-21 11:55 ` Jeff King
2013-03-21 14:58 ` Junio C Hamano
2013-03-21 15:19 ` Junio C Hamano
2013-03-21 15:44 ` Jeff King
2013-03-21 15:44 ` [PATCH 5/4] fast-import: clarify "inline" logic in file_change_m Jeff King
2013-03-21 15:45 ` [PATCH 6/4] run-command: always set failed_errno in start_command Jeff King
2013-03-21 21:02 ` [PATCH 0/4] drop some "int x = x" hacks to silence gcc warnings Jonathan Nieder
2013-03-22 16:18 ` Jeff King
2013-03-22 16:19 ` [PATCH 7/4] submodule: clarify logic in show_submodule_summary Jeff King
2013-03-22 21:10 ` Junio C Hamano
2013-03-22 16:21 ` [PATCH 8/4] match-trees: drop "x = x" initializations Jeff King
2013-03-22 21:26 ` Junio C Hamano
2013-03-22 21:33 ` Junio C Hamano [this message]
2013-03-22 21:36 ` Jeff King
2013-03-23 18:57 ` René Scharfe
2013-03-24 4:55 ` Junio C Hamano
2013-03-24 10:01 ` Jeff King
2013-03-24 22:46 ` René Scharfe
2013-03-25 16:10 ` Junio C Hamano
2013-03-21 13:44 ` [PATCH 0/4] drop some "int x = x" hacks to silence gcc warnings Joachim Schmitz
2013-03-21 13:56 ` Joachim Schmitz
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