[nrf fromtree] logging: log_cmds: Enable log commands for shell with the logging frontend

When shell is integrated with the logging frontend then pointer to
the logging backend in the shell structure is null. When null pointer
is found assume that it is a shell instance with logging frontend
integration and use frontend in the logging commands.

Signed-off-by: Krzysztof Chruściński <[email protected]>
(cherry picked from commit 60d8482)

Author: nordic-krch

subsys/logging/Kconfig.misc

@@ -6,7 +6,7 @@ menu "Misc"
 config LOG_CMDS
 	bool "Shell commands"
 	depends on SHELL
-	depends on !LOG_FRONTEND_ONLY && !LOG_MODE_MINIMAL
+	depends on !LOG_MODE_MINIMAL
 
 config LOG_TEST_CLEAR_MESSAGE_SPACE
 	bool "Clear message after allocation"

subsys/logging/log_cmds.c

@@ -58,8 +58,8 @@ static const struct log_backend *backend_find(char const *name)
 
 static bool shell_state_precheck(const struct shell *sh)
 {
-	if (sh->log_backend->control_block->state
-				== SHELL_LOG_BACKEND_UNINIT) {
+	if (sh->log_backend &&
+	    (sh->log_backend->control_block->state == SHELL_LOG_BACKEND_UNINIT)) {
 		shell_error(sh, "Shell log backend not initialized.");
 		return false;
 	}
@@ -142,8 +142,7 @@ static int cmd_log_self_status(const struct shell *sh,
 		return 0;
 	}
 
-	log_status(sh, sh->log_backend->backend, argc, argv);
-	return 0;
+	return log_status(sh, sh->log_backend ? sh->log_backend->backend : NULL, argc, argv);
 }
 
 static int cmd_log_backend_status(const struct shell *sh,
@@ -246,7 +245,7 @@ static int cmd_log_self_enable(const struct shell *sh,
 		return 0;
 	}
 
-	return log_enable(sh, sh->log_backend->backend, argc, argv);
+	return log_enable(sh, sh->log_backend ? sh->log_backend->backend : NULL, argc, argv);
 }
 
 static int cmd_log_backend_enable(const struct shell *sh,
@@ -271,7 +270,7 @@ static int cmd_log_self_disable(const struct shell *sh,
 		return 0;
 	}
 
-	return log_disable(sh, sh->log_backend->backend, argc, argv);
+	return log_disable(sh, sh->log_backend ? sh->log_backend->backend : NULL, argc, argv);
 }
 
 static int cmd_log_backend_disable(const struct shell *sh,
@@ -327,7 +326,7 @@ static int cmd_log_self_halt(const struct shell *sh,
 		return 0;
 	}
 
-	return log_halt(sh, sh->log_backend->backend, argc, argv);
+	return log_halt(sh, sh->log_backend ? sh->log_backend->backend : NULL, argc, argv);
 }
 
 static int cmd_log_backend_halt(const struct shell *sh,
@@ -359,7 +358,7 @@ static int cmd_log_self_go(const struct shell *sh,
 		return 0;
 	}
 
-	return log_go(sh, sh->log_backend->backend, argc, argv);
+	return log_go(sh, sh->log_backend ? sh->log_backend->backend : NULL, argc, argv);
 }
 
 static int cmd_log_backend_go(const struct shell *sh,