From: Simon Marchi <simon.marchi@efficios.com>
Date: Mon, 3 Apr 2023 01:09:56 +0000 (-0400)
Subject: cli: use return value of g_string_free
X-Git-Url: http://git.efficios.com/?p=babeltrace.git;a=commitdiff_plain;h=2e4a3da35892bf53e49936532a3a04e4c6819cb3

cli: use return value of g_string_free

When building against glib 2.76, I see:

      CC       babeltrace2-cfg-cli-args.o
    In file included from /usr/include/glib-2.0/glib/giochannel.h:36,
                     from /usr/include/glib-2.0/glib.h:56,
                     from /home/simark/src/babeltrace/src/common/assert.h:12,
                     from /home/simark/src/babeltrace/src/logging/log.h:27,
                     from /home/simark/src/babeltrace/src/cli/logging.h:11,
                     from /home/simark/src/babeltrace/src/cli/babeltrace2-cfg-cli-args.c:10:
    /home/simark/src/babeltrace/src/cli/babeltrace2-cfg-cli-args.c: In function ‘plugin_comp_cls_names’:
    /usr/include/glib-2.0/glib/gstring.h:72:5: error: ignoring return value of ‘g_string_free_and_steal’ declared with attribute ‘warn_unused_result’ [-Werror=unused-result]
       68 |   (__builtin_constant_p (free_segment) ?        \
          |   ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
       69 |     ((free_segment) ?                           \
          |     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
       70 |       (g_string_free) ((str), (free_segment)) : \
          |       ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
       71 |       g_string_free_and_steal (str))            \
          |       ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
       72 |     :                                           \
          |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
       73 |     (g_string_free) ((str), (free_segment)))
          |     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    /home/simark/src/babeltrace/src/cli/babeltrace2-cfg-cli-args.c:136:25: note: in expansion of macro ‘g_string_free’
      136 |                         g_string_free(gs_name, FALSE);
          |                         ^~~~~~~~~~~~~

glib made g_string_free warn about unused results in this commit:

  https://gitlab.gnome.org/GNOME/glib/-/commit/c3d07a625a407b56432f4b8c60295fd32ee1ee2b

Fix that by changing our code to get the released value from the return
value of g_string_free, rather than doing it in two steps..  No
functional changes intended.

Change-Id: I62f4002d0487165b7c9d33f471937185f3bc0f82
Reviewed-on: https://review.lttng.org/c/babeltrace/+/9728
Tested-by: jenkins <jenkins@lttng.org>
Reviewed-by: Philippe Proulx <eeppeliteloop@gmail.com>
---

diff --git a/src/cli/babeltrace2-cfg-cli-args.c b/src/cli/babeltrace2-cfg-cli-args.c
index 6c187b4f..a0da0ddf 100644
--- a/src/cli/babeltrace2-cfg-cli-args.c
+++ b/src/cli/babeltrace2-cfg-cli-args.c
@@ -132,17 +132,14 @@ void plugin_comp_cls_names(const char *arg, char **name, char **plugin,
 			*name = NULL;
 			g_string_free(gs_name, TRUE);
 		} else {
-			*name = gs_name->str;
-			g_string_free(gs_name, FALSE);
+			*name = g_string_free(gs_name, FALSE);
 		}
 	} else {
 		g_string_free(gs_name, TRUE);
 	}
 
-	*plugin = gs_plugin->str;
-	*comp_cls = gs_comp_cls->str;
-	g_string_free(gs_plugin, FALSE);
-	g_string_free(gs_comp_cls, FALSE);
+	*plugin = g_string_free(gs_plugin, FALSE);
+	*comp_cls = g_string_free(gs_comp_cls, FALSE);
 	gs_name = NULL;
 	gs_plugin = NULL;
 	gs_comp_cls = NULL;
@@ -3088,10 +3085,8 @@ int split_timerange(const char *arg, char **begin, char **end)
 
 	BT_ASSERT(begin);
 	BT_ASSERT(end);
-	*begin = g_begin->str;
-	*end = g_end->str;
-	g_string_free(g_begin, FALSE);
-	g_string_free(g_end, FALSE);
+	*begin = g_string_free(g_begin, FALSE);
+	*end = g_string_free(g_end, FALSE);
 	g_begin = NULL;
 	g_end = NULL;
 	goto end;