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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 <jlh@gmx.ch>.

Signed-off-by: Jim Meyering <meyering@redhat.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
  • Loading branch information...
1 parent 22c430a commit 8e0f70033b2bd1679a6e5971978fdc3ee09bdb72 Jim Meyering committed with gitster Jan 31, 2008
Showing with 28 additions and 55 deletions.
  1. +1 −2 builtin-blame.c
  2. +3 −6 builtin-branch.c
  3. +1 −2 builtin-fast-export.c
  4. +1 −2 builtin-http-fetch.c
  5. +1 −2 builtin-pack-objects.c
  6. +1 −2 builtin-revert.c
  7. +1 −2 connect.c
  8. +3 −6 diff.c
  9. +1 −2 dir.c
  10. +6 −12 http-push.c
  11. +2 −3 imap-send.c
  12. +1 −2 interpolate.c
  13. +1 −2 pretty.c
  14. +1 −2 remote.c
  15. +1 −2 setup.c
  16. +2 −4 sha1_name.c
  17. +1 −2 xdiff-interface.c
View
@@ -123,8 +123,7 @@ static inline struct origin *origin_incref(struct origin *o)
static void origin_decref(struct origin *o)
{
if (o && --o->refcnt <= 0) {
- if (o->file.ptr)
- free(o->file.ptr);
+ free(o->file.ptr);
free(o);
}
}
View
@@ -126,8 +126,7 @@ static int delete_branches(int argc, const char **argv, int force, int kinds)
continue;
}
- if (name)
- free(name);
+ free(name);
name = xstrdup(mkpath(fmt, argv[i]));
if (!resolve_ref(name, sha1, 1, NULL)) {
@@ -172,8 +171,7 @@ static int delete_branches(int argc, const char **argv, int force, int kinds)
}
}
- if (name)
- free(name);
+ free(name);
return(ret);
}
@@ -490,8 +488,7 @@ static void create_branch(const char *name, const char *start_name,
if (write_ref_sha1(lock, sha1, msg) < 0)
die("Failed to write ref: %s.", strerror(errno));
- if (real_ref)
- free(real_ref);
+ free(real_ref);
}
static void rename_branch(const char *oldname, const char *newname, int force)
View
@@ -196,8 +196,7 @@ static void handle_commit(struct commit *commit, struct rev_info *rev)
? strlen(reencoded) : message
? strlen(message) : 0),
reencoded ? reencoded : message ? message : "");
- if (reencoded)
- free(reencoded);
+ free(reencoded);
for (i = 0, p = commit->parents; p; p = p->next) {
int mark = get_object_mark(&p->item->object);
View
@@ -80,8 +80,7 @@ int cmd_http_fetch(int argc, const char **argv, const char *prefix)
walker_free(walker);
- if (rewritten_url)
- free(rewritten_url);
+ free(rewritten_url);
return rc;
}
View
@@ -1428,8 +1428,7 @@ static int try_delta(struct unpacked *trg, struct unpacked *src,
* accounting lock. Compiler will optimize the strangeness
* away when THREADED_DELTA_SEARCH is not defined.
*/
- if (trg_entry->delta_data)
- free(trg_entry->delta_data);
+ free(trg_entry->delta_data);
cache_lock();
if (trg_entry->delta_data) {
delta_cache_size -= trg_entry->delta_size;
View
@@ -397,8 +397,7 @@ static int revert_or_cherry_pick(int argc, const char **argv)
else
return execl_git_cmd("commit", "-n", "-F", defmsg, NULL);
}
- if (reencoded_message)
- free(reencoded_message);
+ free(reencoded_message);
return 0;
}
View
@@ -68,8 +68,7 @@ struct ref **get_remote_heads(int in, struct ref **list,
name_len = strlen(name);
if (len != name_len + 41) {
- if (server_capabilities)
- free(server_capabilities);
+ free(server_capabilities);
server_capabilities = xstrdup(name + name_len + 1);
}
View
9 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;
}
View
3 dir.c
@@ -704,8 +704,7 @@ static struct path_simplify *create_simplify(const char **pathspec)
static void free_simplify(struct path_simplify *simplify)
{
- if (simplify)
- free(simplify);
+ free(simplify);
}
int read_directory(struct dir_struct *dir, const char *path, const char *base, int baselen, const char **pathspec)
View
@@ -664,8 +664,7 @@ static void release_request(struct transfer_request *request)
close(request->local_fileno);
if (request->local_stream)
fclose(request->local_stream);
- if (request->url != NULL)
- free(request->url);
+ free(request->url);
free(request);
}
@@ -1283,10 +1282,8 @@ static struct remote_lock *lock_remote(const char *path, long timeout)
strbuf_release(&in_buffer);
if (lock->token == NULL || lock->timeout <= 0) {
- if (lock->token != NULL)
- free(lock->token);
- if (lock->owner != NULL)
- free(lock->owner);
+ free(lock->token);
+ free(lock->owner);
free(url);
free(lock);
lock = NULL;
@@ -1344,8 +1341,7 @@ static int unlock_remote(struct remote_lock *lock)
prev->next = prev->next->next;
}
- if (lock->owner != NULL)
- free(lock->owner);
+ free(lock->owner);
free(lock->url);
free(lock->token);
free(lock);
@@ -2035,8 +2031,7 @@ static void fetch_symref(const char *path, char **symref, unsigned char *sha1)
}
free(url);
- if (*symref != NULL)
- free(*symref);
+ free(*symref);
*symref = NULL;
hashclr(sha1);
@@ -2435,8 +2430,7 @@ int main(int argc, char **argv)
}
cleanup:
- if (rewritten_url)
- free(rewritten_url);
+ free(rewritten_url);
if (info_ref_lock)
unlock_remote(info_ref_lock);
free(remote);
View
@@ -472,7 +472,7 @@ v_issue_imap_cmd( imap_store_t *ctx, struct imap_cmd_cb *cb,
if (socket_write( &imap->buf.sock, buf, bufl ) != bufl) {
free( cmd->cmd );
free( cmd );
- if (cb && cb->data)
+ if (cb)
free( cb->data );
return NULL;
}
@@ -858,8 +858,7 @@ get_cmd_result( imap_store_t *ctx, struct imap_cmd *tcmd )
normal:
if (cmdp->cb.done)
cmdp->cb.done( ctx, cmdp, resp );
- if (cmdp->cb.data)
- free( cmdp->cb.data );
+ free( cmdp->cb.data );
free( cmdp->cmd );
free( cmdp );
if (!tcmd || tcmd == cmdp)
View
@@ -11,8 +11,7 @@ void interp_set_entry(struct interp *table, int slot, const char *value)
char *oldval = table[slot].value;
char *newval = NULL;
- if (oldval)
- free(oldval);
+ free(oldval);
if (value)
newval = xstrdup(value);
View
@@ -30,8 +30,7 @@ enum cmit_fmt get_commit_format(const char *arg)
if (*arg == '=')
arg++;
if (!prefixcmp(arg, "format:")) {
- if (user_format)
- free(user_format);
+ free(user_format);
user_format = xstrdup(arg + 7);
return CMIT_FMT_USERFORMAT;
}
View
@@ -506,8 +506,7 @@ void free_refs(struct ref *ref)
struct ref *next;
while (ref) {
next = ref->next;
- if (ref->peer_ref)
- free(ref->peer_ref);
+ free(ref->peer_ref);
free(ref);
ref = next;
}
View
@@ -448,8 +448,7 @@ int check_repository_format_version(const char *var, const char *value)
} else if (strcmp(var, "core.worktree") == 0) {
if (!value)
return config_error_nonbool(var);
- if (git_work_tree_cfg)
- free(git_work_tree_cfg);
+ free(git_work_tree_cfg);
git_work_tree_cfg = xstrdup(value);
inside_work_tree = -1;
}
View
@@ -625,8 +625,7 @@ static int get_sha1_oneline(const char *prefix, unsigned char *sha1)
commit = pop_most_recent_commit(&list, ONELINE_SEEN);
if (!parse_object(commit->object.sha1))
continue;
- if (temp_commit_buffer)
- free(temp_commit_buffer);
+ free(temp_commit_buffer);
if (commit->buffer)
p = commit->buffer;
else {
@@ -643,8 +642,7 @@ static int get_sha1_oneline(const char *prefix, unsigned char *sha1)
break;
}
}
- if (temp_commit_buffer)
- free(temp_commit_buffer);
+ free(temp_commit_buffer);
free_commit_list(list);
for (l = backup; l; l = l->next)
clear_commit_marks(l->item, ONELINE_SEEN);
View
@@ -233,8 +233,7 @@ void xdiff_set_find_func(xdemitconf_t *xecfg, const char *value)
expression = value;
if (regcomp(&reg->re, expression, 0))
die("Invalid regexp to look for hunk header: %s", expression);
- if (buffer)
- free(buffer);
+ free(buffer);
value = ep + 1;
}
}

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