Avoid unnecessary "if-before-free" tests.
authorJim Meyering <meyering@redhat.com>
Thu, 31 Jan 2008 17:26:32 +0000 (18:26 +0100)
committerJunio C Hamano <gitster@pobox.com>
Fri, 22 Feb 2008 22:14:40 +0000 (14:14 -0800)
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>
17 files changed:
builtin-blame.c
builtin-branch.c
builtin-fast-export.c
builtin-http-fetch.c
builtin-pack-objects.c
builtin-revert.c
connect.c
diff.c
dir.c
http-push.c
imap-send.c
interpolate.c
pretty.c
remote.c
setup.c
sha1_name.c
xdiff-interface.c

index 59d7237..bfd562d 100644 (file)
@@ -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);
        }
 }
index 9edf2eb..7917700 100644 (file)
@@ -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)
index f741df5..49b54de 100755 (executable)
@@ -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);
index 7f450c6..299093f 100644 (file)
@@ -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;
 }
index d2bb12e..7dff653 100644 (file)
@@ -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;
index e219859..b6dee6a 100644 (file)
@@ -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;
 }
index 5ac3572..d12b105 100644 (file)
--- a/connect.c
+++ b/connect.c
@@ -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);
                }
 
diff --git a/diff.c b/diff.c
index 699b21f..f08e663 100644 (file)
--- 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;
        }
diff --git a/dir.c b/dir.c
index 1f507da..edc458e 100644 (file)
--- a/dir.c
+++ b/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)
index 0beb740..406270f 100644 (file)
@@ -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);
index 9025d9a..10cce15 100644 (file)
@@ -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)
index 6ef53f2..7f03bd9 100644 (file)
@@ -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);
index 997f583..4bf3be2 100644 (file)
--- a/pretty.c
+++ b/pretty.c
@@ -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;
        }
index 6b56473..ae1ef57 100644 (file)
--- a/remote.c
+++ b/remote.c
@@ -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;
        }
diff --git a/setup.c b/setup.c
index dc247a8..89c81e5 100644 (file)
--- a/setup.c
+++ b/setup.c
@@ -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;
        }
index c2805e7..9d088cc 100644 (file)
@@ -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);
index 4b8e5cc..bba2364 100644 (file)
@@ -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;
        }
 }