Re: [coreutils] [PATCH] maint: suppress some clang scan-build warnings (original) (raw)

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

From: Jim Meyering
Subject: Re: [coreutils] [PATCH] maint: suppress some clang scan-build warnings
Date: Fri, 07 Jan 2011 08:38:48 +0100

Pádraig Brady wrote:

maint: suppress some clang scan-build warnings

* src/pr.c (chartoclump): Remove a dead store. * src/remove.c (ftsskiptree): Likewise. * src/sort.c (keywarnings): Likewise. (sort): Suppress an uninitialized pointer warning.

Thanks! That is fine, with one correction below.

I hope clang's analysis improves to the point that we can make coreutils warning-free without too much effort. I noticed that this warning about ln.c is bogus:

203 && (backup_type == no_backups || !symbolic_link)
204 && (!symbolic_link || stat (source, &source_stats) == 0)
205 && SAME_INODE (source_stats, dest_stats)

  Within the expansion of the macro 'SAME_INODE':
  The left operand of '==' is a garbage value

Here's the expansion: ((source_stats).st_ino == (dest_stats).st_ino && (source_stats).st_dev == (dest_stats).st_dev)

The problem is that clang made the assumption, a few lines above, that "symbolic_link" was true, yet doesn't deduce the consequence: whenever SAME_INODE is reached, the just-prior call to stat has succeeded, and hence has defined "source_stats".

...

diff --git a/src/sort.c b/src/sort.c ... @@ -3770,6 +3770,7 @@ sort (char *const *files, sizet nfiles, char const *outputfile, sizet nthreads) { struct buffer buf; + IFLINT (buf.buf == NULL);

ETOOLATE ;-) You must mean this:

IF_LINT (buf.buf = NULL);