date API: add and use a date_mode_release()

Fix a memory leak in the parse_date_format() function by providing a
new date_mode_release() companion function.

By using this in "t/helper/test-date.c" we can mark the
"t0006-date.sh" test as passing when git is compiled with
SANITIZE=leak, and whitelist it to run under
"GIT_TEST_PASSING_SANITIZE_LEAK=true" by adding
"TEST_PASSES_SANITIZE_LEAK=true" to the test itself.

The other tests that expose this memory leak (i.e. take the
"mode->type == DATE_STRFTIME" branch in parse_date_format()) are
"t6300-for-each-ref.sh" and "t7004-tag.sh". The former is due to an
easily fixed leak in "ref-filter.c", and brings the failures in
"t6300-for-each-ref.sh" down from 51 to 48.

Fixing the remaining leaks will have to wait until there's a
release_revisions() in "revision.c", as they have to do with leaks via
"struct rev_info".

There is also a leak in "builtin/blame.c" due to its call to
parse_date_format() to parse the "blame.date" configuration. However
as it declares a file-level "static struct date_mode blame_date_mode"
to track the data, LSAN will not report it as a leak. It's possible to
get valgrind(1) to complain about it with e.g.:

    valgrind --leak-check=full --show-leak-kinds=all ./git -P -c blame.date=format:%Y blame README.md

But let's focus on things LSAN complains about, and are thus
observable with "TEST_PASSES_SANITIZE_LEAK=true". We should get to
fixing memory leaks in "builtin/blame.c", but as doing so would
require some re-arrangement of cmd_blame() let's leave it for some
other time.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/date.c b/date.c
index 54c709e4a089acfff0f060683abad9ea4e84cf8c..68a260c214d333f61bf1c9156405520e8fc9c361 100644 (file)
--- a/date.c
+++ b/date.c
@@ -993,6 +993,11 @@ void parse_date_format(const char *format, struct date_mode *mode)
                die("unknown date format %s", format);
 }
 
+void date_mode_release(struct date_mode *mode)
+{
+       free((char *)mode->strftime_fmt);
+}
+
 void datestamp(struct strbuf *out)
 {
        time_t now;

diff --git a/date.h b/date.h
index bbd6a6477b50ee5ba3b2e6f9a08e301dfa010317..5d4eaba0a90e39f8684bb5500695ba07b5ea5521 100644 (file)
--- a/date.h
+++ b/date.h
@@ -50,10 +50,17 @@ const char *show_date(timestamp_t time, int timezone, const struct date_mode *mo
  *
  * When the "date_mode_type" is DATE_STRFTIME the "strftime_fmt"
  * member of "struct date_mode" will be a malloc()'d format string to
- * be used with strbuf_addftime().
+ * be used with strbuf_addftime(), in which case you'll need to call
+ * date_mode_release() later.
  */
 void parse_date_format(const char *format, struct date_mode *mode);
 
+/**
+ * Release a "struct date_mode", currently only required if
+ * parse_date_format() has parsed a "DATE_STRFTIME" format.
+ */
+void date_mode_release(struct date_mode *mode);
+
 void show_date_relative(timestamp_t time, struct strbuf *timebuf);
 int parse_date(const char *date, struct strbuf *out);
 int parse_date_basic(const char *date, timestamp_t *timestamp, int *offset);

diff --git a/ref-filter.c b/ref-filter.c
index 3399bde932f7e8c7de5acbaff95c8ed9013d37c1..7838bd22b8db1bd52859361a4f3b7789c2cf4b5b 100644 (file)
--- a/ref-filter.c
+++ b/ref-filter.c
@@ -1276,6 +1276,7 @@ static void grab_date(const char *buf, struct atom_value *v, const char *atomnam
                goto bad;
        v->s = xstrdup(show_date(timestamp, tz, &date_mode));
        v->value = timestamp;
+       date_mode_release(&date_mode);
        return;
  bad:
        v->s = xstrdup("");

diff --git a/t/helper/test-date.c b/t/helper/test-date.c
index 111071e1dd16d0cf81dce5cbea0e2f075bdbd0bc..45951b1df87c7bf90a25cc1497344681ae42a161 100644 (file)
--- a/t/helper/test-date.c
+++ b/t/helper/test-date.c
@@ -54,6 +54,8 @@ static void show_dates(const char **argv, const char *format)
 
                printf("%s -> %s\n", *argv, show_date(t, tz, &mode));
        }
+
+       date_mode_release(&mode);
 }
 
 static void parse_dates(const char **argv)

diff --git a/t/t0006-date.sh b/t/t0006-date.sh
index 794186961eebcc0edc8442b8d730287a5ff2c67a..2490162071e700e8a69d0e6311b6f22eda4e7046 100755 (executable)
--- a/t/t0006-date.sh
+++ b/t/t0006-date.sh
@@ -1,6 +1,8 @@
 #!/bin/sh
 
 test_description='test date parsing and printing'
+
+TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 
 # arbitrary reference time: 2009-08-30 19:20:00