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git/builtin/name-rev.c
Johannes Schindelin 5308224633 name-rev: avoid leaking memory in the deref case
When the `name_rev()` function is asked to dereference the tip name, it
allocates memory. But when it turns out that another tip already
described the commit better than the current one, we forgot to release
the memory.

Pointed out by Coverity.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-05-08 12:18:20 +09:00

452 lines
11 KiB
C

#include "builtin.h"
#include "cache.h"
#include "commit.h"
#include "tag.h"
#include "refs.h"
#include "parse-options.h"
#include "sha1-lookup.h"
#define CUTOFF_DATE_SLOP 86400 /* one day */
typedef struct rev_name {
const char *tip_name;
unsigned long taggerdate;
int generation;
int distance;
} rev_name;
static long cutoff = LONG_MAX;
/* How many generations are maximally preferred over _one_ merge traversal? */
#define MERGE_TRAVERSAL_WEIGHT 65535
static void name_rev(struct commit *commit,
const char *tip_name, unsigned long taggerdate,
int generation, int distance,
int deref)
{
struct rev_name *name = (struct rev_name *)commit->util;
struct commit_list *parents;
int parent_number = 1;
char *to_free = NULL;
parse_commit(commit);
if (commit->date < cutoff)
return;
if (deref) {
tip_name = to_free = xstrfmt("%s^0", tip_name);
if (generation)
die("generation: %d, but deref?", generation);
}
if (name == NULL) {
name = xmalloc(sizeof(rev_name));
commit->util = name;
goto copy_data;
} else if (name->taggerdate > taggerdate ||
(name->taggerdate == taggerdate &&
name->distance > distance)) {
copy_data:
name->tip_name = tip_name;
name->taggerdate = taggerdate;
name->generation = generation;
name->distance = distance;
} else {
free(to_free);
return;
}
for (parents = commit->parents;
parents;
parents = parents->next, parent_number++) {
if (parent_number > 1) {
size_t len;
char *new_name;
strip_suffix(tip_name, "^0", &len);
if (generation > 0)
new_name = xstrfmt("%.*s~%d^%d", (int)len, tip_name,
generation, parent_number);
else
new_name = xstrfmt("%.*s^%d", (int)len, tip_name,
parent_number);
name_rev(parents->item, new_name, taggerdate, 0,
distance + MERGE_TRAVERSAL_WEIGHT, 0);
} else {
name_rev(parents->item, tip_name, taggerdate,
generation + 1, distance + 1, 0);
}
}
}
static int subpath_matches(const char *path, const char *filter)
{
const char *subpath = path;
while (subpath) {
if (!wildmatch(filter, subpath, 0, NULL))
return subpath - path;
subpath = strchr(subpath, '/');
if (subpath)
subpath++;
}
return -1;
}
static const char *name_ref_abbrev(const char *refname, int shorten_unambiguous)
{
if (shorten_unambiguous)
refname = shorten_unambiguous_ref(refname, 0);
else if (starts_with(refname, "refs/heads/"))
refname = refname + 11;
else if (starts_with(refname, "refs/"))
refname = refname + 5;
return refname;
}
struct name_ref_data {
int tags_only;
int name_only;
struct string_list ref_filters;
struct string_list exclude_filters;
};
static struct tip_table {
struct tip_table_entry {
unsigned char sha1[20];
const char *refname;
} *table;
int nr;
int alloc;
int sorted;
} tip_table;
static void add_to_tip_table(const unsigned char *sha1, const char *refname,
int shorten_unambiguous)
{
refname = name_ref_abbrev(refname, shorten_unambiguous);
ALLOC_GROW(tip_table.table, tip_table.nr + 1, tip_table.alloc);
hashcpy(tip_table.table[tip_table.nr].sha1, sha1);
tip_table.table[tip_table.nr].refname = xstrdup(refname);
tip_table.nr++;
tip_table.sorted = 0;
}
static int tipcmp(const void *a_, const void *b_)
{
const struct tip_table_entry *a = a_, *b = b_;
return hashcmp(a->sha1, b->sha1);
}
static int name_ref(const char *path, const struct object_id *oid, int flags, void *cb_data)
{
struct object *o = parse_object(oid->hash);
struct name_ref_data *data = cb_data;
int can_abbreviate_output = data->tags_only && data->name_only;
int deref = 0;
unsigned long taggerdate = ULONG_MAX;
if (data->tags_only && !starts_with(path, "refs/tags/"))
return 0;
if (data->exclude_filters.nr) {
struct string_list_item *item;
for_each_string_list_item(item, &data->exclude_filters) {
if (subpath_matches(path, item->string) >= 0)
return 0;
}
}
if (data->ref_filters.nr) {
struct string_list_item *item;
int matched = 0;
/* See if any of the patterns match. */
for_each_string_list_item(item, &data->ref_filters) {
/*
* Check all patterns even after finding a match, so
* that we can see if a match with a subpath exists.
* When a user asked for 'refs/tags/v*' and 'v1.*',
* both of which match, the user is showing her
* willingness to accept a shortened output by having
* the 'v1.*' in the acceptable refnames, so we
* shouldn't stop when seeing 'refs/tags/v1.4' matches
* 'refs/tags/v*'. We should show it as 'v1.4'.
*/
switch (subpath_matches(path, item->string)) {
case -1: /* did not match */
break;
case 0: /* matched fully */
matched = 1;
break;
default: /* matched subpath */
matched = 1;
can_abbreviate_output = 1;
break;
}
}
/* If none of the patterns matched, stop now */
if (!matched)
return 0;
}
add_to_tip_table(oid->hash, path, can_abbreviate_output);
while (o && o->type == OBJ_TAG) {
struct tag *t = (struct tag *) o;
if (!t->tagged)
break; /* broken repository */
o = parse_object(t->tagged->oid.hash);
deref = 1;
taggerdate = t->date;
}
if (o && o->type == OBJ_COMMIT) {
struct commit *commit = (struct commit *)o;
path = name_ref_abbrev(path, can_abbreviate_output);
name_rev(commit, xstrdup(path), taggerdate, 0, 0, deref);
}
return 0;
}
static const unsigned char *nth_tip_table_ent(size_t ix, void *table_)
{
struct tip_table_entry *table = table_;
return table[ix].sha1;
}
static const char *get_exact_ref_match(const struct object *o)
{
int found;
if (!tip_table.table || !tip_table.nr)
return NULL;
if (!tip_table.sorted) {
QSORT(tip_table.table, tip_table.nr, tipcmp);
tip_table.sorted = 1;
}
found = sha1_pos(o->oid.hash, tip_table.table, tip_table.nr,
nth_tip_table_ent);
if (0 <= found)
return tip_table.table[found].refname;
return NULL;
}
/* may return a constant string or use "buf" as scratch space */
static const char *get_rev_name(const struct object *o, struct strbuf *buf)
{
struct rev_name *n;
struct commit *c;
if (o->type != OBJ_COMMIT)
return get_exact_ref_match(o);
c = (struct commit *) o;
n = c->util;
if (!n)
return NULL;
if (!n->generation)
return n->tip_name;
else {
int len = strlen(n->tip_name);
if (len > 2 && !strcmp(n->tip_name + len - 2, "^0"))
len -= 2;
strbuf_reset(buf);
strbuf_addf(buf, "%.*s~%d", len, n->tip_name, n->generation);
return buf->buf;
}
}
static void show_name(const struct object *obj,
const char *caller_name,
int always, int allow_undefined, int name_only)
{
const char *name;
const struct object_id *oid = &obj->oid;
struct strbuf buf = STRBUF_INIT;
if (!name_only)
printf("%s ", caller_name ? caller_name : oid_to_hex(oid));
name = get_rev_name(obj, &buf);
if (name)
printf("%s\n", name);
else if (allow_undefined)
printf("undefined\n");
else if (always)
printf("%s\n", find_unique_abbrev(oid->hash, DEFAULT_ABBREV));
else
die("cannot describe '%s'", oid_to_hex(oid));
strbuf_release(&buf);
}
static char const * const name_rev_usage[] = {
N_("git name-rev [<options>] <commit>..."),
N_("git name-rev [<options>] --all"),
N_("git name-rev [<options>] --stdin"),
NULL
};
static void name_rev_line(char *p, struct name_ref_data *data)
{
struct strbuf buf = STRBUF_INIT;
int forty = 0;
char *p_start;
for (p_start = p; *p; p++) {
#define ishex(x) (isdigit((x)) || ((x) >= 'a' && (x) <= 'f'))
if (!ishex(*p))
forty = 0;
else if (++forty == 40 &&
!ishex(*(p+1))) {
unsigned char sha1[40];
const char *name = NULL;
char c = *(p+1);
int p_len = p - p_start + 1;
forty = 0;
*(p+1) = 0;
if (!get_sha1(p - 39, sha1)) {
struct object *o =
lookup_object(sha1);
if (o)
name = get_rev_name(o, &buf);
}
*(p+1) = c;
if (!name)
continue;
if (data->name_only)
printf("%.*s%s", p_len - 40, p_start, name);
else
printf("%.*s (%s)", p_len, p_start, name);
p_start = p + 1;
}
}
/* flush */
if (p_start != p)
fwrite(p_start, p - p_start, 1, stdout);
strbuf_release(&buf);
}
int cmd_name_rev(int argc, const char **argv, const char *prefix)
{
struct object_array revs = OBJECT_ARRAY_INIT;
int all = 0, transform_stdin = 0, allow_undefined = 1, always = 0, peel_tag = 0;
struct name_ref_data data = { 0, 0, STRING_LIST_INIT_NODUP, STRING_LIST_INIT_NODUP };
struct option opts[] = {
OPT_BOOL(0, "name-only", &data.name_only, N_("print only names (no SHA-1)")),
OPT_BOOL(0, "tags", &data.tags_only, N_("only use tags to name the commits")),
OPT_STRING_LIST(0, "refs", &data.ref_filters, N_("pattern"),
N_("only use refs matching <pattern>")),
OPT_STRING_LIST(0, "exclude", &data.exclude_filters, N_("pattern"),
N_("ignore refs matching <pattern>")),
OPT_GROUP(""),
OPT_BOOL(0, "all", &all, N_("list all commits reachable from all refs")),
OPT_BOOL(0, "stdin", &transform_stdin, N_("read from stdin")),
OPT_BOOL(0, "undefined", &allow_undefined, N_("allow to print `undefined` names (default)")),
OPT_BOOL(0, "always", &always,
N_("show abbreviated commit object as fallback")),
{
/* A Hidden OPT_BOOL */
OPTION_SET_INT, 0, "peel-tag", &peel_tag, NULL,
N_("dereference tags in the input (internal use)"),
PARSE_OPT_NOARG | PARSE_OPT_HIDDEN, NULL, 1,
},
OPT_END(),
};
git_config(git_default_config, NULL);
argc = parse_options(argc, argv, prefix, opts, name_rev_usage, 0);
if (all + transform_stdin + !!argc > 1) {
error("Specify either a list, or --all, not both!");
usage_with_options(name_rev_usage, opts);
}
if (all || transform_stdin)
cutoff = 0;
for (; argc; argc--, argv++) {
unsigned char sha1[20];
struct object *object;
struct commit *commit;
if (get_sha1(*argv, sha1)) {
fprintf(stderr, "Could not get sha1 for %s. Skipping.\n",
*argv);
continue;
}
commit = NULL;
object = parse_object(sha1);
if (object) {
struct object *peeled = deref_tag(object, *argv, 0);
if (peeled && peeled->type == OBJ_COMMIT)
commit = (struct commit *)peeled;
}
if (!object) {
fprintf(stderr, "Could not get object for %s. Skipping.\n",
*argv);
continue;
}
if (commit) {
if (cutoff > commit->date)
cutoff = commit->date;
}
if (peel_tag) {
if (!commit) {
fprintf(stderr, "Could not get commit for %s. Skipping.\n",
*argv);
continue;
}
object = (struct object *)commit;
}
add_object_array(object, *argv, &revs);
}
if (cutoff)
cutoff = cutoff - CUTOFF_DATE_SLOP;
for_each_ref(name_ref, &data);
if (transform_stdin) {
char buffer[2048];
while (!feof(stdin)) {
char *p = fgets(buffer, sizeof(buffer), stdin);
if (!p)
break;
name_rev_line(p, &data);
}
} else if (all) {
int i, max;
max = get_max_object_index();
for (i = 0; i < max; i++) {
struct object *obj = get_indexed_object(i);
if (!obj || obj->type != OBJ_COMMIT)
continue;
show_name(obj, NULL,
always, allow_undefined, data.name_only);
}
} else {
int i;
for (i = 0; i < revs.nr; i++)
show_name(revs.objects[i].item, revs.objects[i].name,
always, allow_undefined, data.name_only);
}
return 0;
}