From 8e0f70033b2bd1679a6e5971978fdc3ee09bdb72 Mon Sep 17 00:00:00 2001 From: Jim Meyering Date: Thu, 31 Jan 2008 18:26:32 +0100 Subject: Avoid unnecessary "if-before-free" tests. This change removes all obvious useless if-before-free tests. E.g., it replaces code like this: if (some_expression) free (some_expression); with the now-equivalent: free (some_expression); It is equivalent not just because POSIX has required free(NULL) to work for a long time, but simply because it has worked for so long that no reasonable porting target fails the test. Here's some evidence from nearly 1.5 years ago: http://www.winehq.org/pipermail/wine-patches/2006-October/031544.html FYI, the change below was prepared by running the following: git ls-files -z | xargs -0 \ perl -0x3b -pi -e \ 's/\bif\s*\(\s*(\S+?)(?:\s*!=\s*NULL)?\s*\)\s+(free\s*\(\s*\1\s*\))/$2/s' Note however, that it doesn't handle brace-enclosed blocks like "if (x) { free (x); }". But that's ok, since there were none like that in git sources. Beware: if you do use the above snippet, note that it can produce syntactically invalid C code. That happens when the affected "if"-statement has a matching "else". E.g., it would transform this if (x) free (x); else foo (); into this: free (x); else foo (); There were none of those here, either. If you're interested in automating detection of the useless tests, you might like the useless-if-before-free script in gnulib: [it *does* detect brace-enclosed free statements, and has a --name=S option to make it detect free-like functions with different names] http://git.sv.gnu.org/gitweb/?p=gnulib.git;a=blob;f=build-aux/useless-if-before-free Addendum: Remove one more (in imap-send.c), spotted by Jean-Luc Herren . Signed-off-by: Jim Meyering Signed-off-by: Junio C Hamano --- xdiff-interface.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) (limited to 'xdiff-interface.c') diff --git a/xdiff-interface.c b/xdiff-interface.c index 4b8e5cca80..bba236428a 100644 --- a/xdiff-interface.c +++ b/xdiff-interface.c @@ -233,8 +233,7 @@ void xdiff_set_find_func(xdemitconf_t *xecfg, const char *value) expression = value; if (regcomp(®->re, expression, 0)) die("Invalid regexp to look for hunk header: %s", expression); - if (buffer) - free(buffer); + free(buffer); value = ep + 1; } } -- cgit v1.2.1