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 --- diff.c | 9 +++------ 1 file changed, 3 insertions(+), 6 deletions(-) (limited to 'diff.c') diff --git a/diff.c b/diff.c index 699b21f4e3..f08e663b86 100644 --- a/diff.c +++ b/diff.c @@ -118,8 +118,7 @@ static int parse_funcname_pattern(const char *var, const char *ep, const char *v pp->next = funcname_pattern_list; funcname_pattern_list = pp; } - if (pp->pattern) - free(pp->pattern); + free(pp->pattern); pp->pattern = xstrdup(value); return 0; } @@ -492,10 +491,8 @@ static void free_diff_words_data(struct emit_callback *ecbdata) ecbdata->diff_words->plus.text.size) diff_words_show(ecbdata->diff_words); - if (ecbdata->diff_words->minus.text.ptr) - free (ecbdata->diff_words->minus.text.ptr); - if (ecbdata->diff_words->plus.text.ptr) - free (ecbdata->diff_words->plus.text.ptr); + free (ecbdata->diff_words->minus.text.ptr); + free (ecbdata->diff_words->plus.text.ptr); free(ecbdata->diff_words); ecbdata->diff_words = NULL; } -- cgit v1.2.1