[lttng-dev] [PATCH lttng-tools] Add with-sessiond-bin configure option

[Simon Marchi]

I also cleaned up the little check_sessiond function. The check using
access(2) was only done for the command line option, but I think it is a
good idea to do it wherever the path comes from.

closes #441

Signed-off-by: Simon Marchi <simon.marchi at polymtl.ca>
---
 configure.ac          |   17 +++++++++++++++++
 src/bin/lttng/lttng.c |   37 ++++++++++++++++++++-----------------
 2 files changed, 37 insertions(+), 17 deletions(-)

diff --git a/configure.ac b/configure.ac
index 71fbb60..7349713 100644
--- a/configure.ac
+++ b/configure.ac
@@ -91,12 +91,20 @@ AC_ARG_WITH([consumerd64-libdir],
 	[CONSUMERD64_LIBDIR=''])
 AC_SUBST([CONSUMERD64_LIBDIR])
 
+AC_ARG_WITH([sessiond-bin],
+	AS_HELP_STRING([--with-sessiond-bin],
+	[Location of the sessiond executable (including the filename)]),
+	[SESSIOND_BIN="$withval"],
+	[SESSIOND_BIN=''])
+AC_SUBST([SESSIOND_BIN])
+
 AC_DEFINE_UNQUOTED([CONFIG_CONSUMERD32_BIN], "$CONSUMERD32_BIN", [Location of the 32-bit consumerd executable.])
 AC_DEFINE_UNQUOTED([CONFIG_CONSUMERD64_BIN], "$CONSUMERD64_BIN", [Location of the 64-bit consumerd executable])
 AC_DEFINE_UNQUOTED([CONFIG_CONSUMERD32_LIBDIR], "$CONSUMERD32_LIBDIR", [Search for consumerd 32-bit libraries in this location.])
 AC_DEFINE_UNQUOTED([CONFIG_CONSUMERD64_LIBDIR], "$CONSUMERD64_LIBDIR", [Search for consumerd 64-bit libraries in this location.])
 AC_DEFINE_UNQUOTED([CONFIG_BABELTRACE_BIN], "$BABELTRACE_BIN", [Location of the babeltrace viewer executable.])
 AC_DEFINE_UNQUOTED([CONFIG_LTTV_GUI_BIN], "$LTTV_GUI_BIN", [Location of the lttv GUI viewer executable.])
+AC_DEFINE_UNQUOTED([CONFIG_SESSIOND_BIN], "$SESSIOND_BIN", [Location of the sessiond executable.])
 
 # Check for pthread
 AC_CHECK_LIB([pthread], [pthread_create], [],
@@ -383,6 +391,15 @@ AS_ECHO("`eval eval echo $libdir`")
 # If we build the sessiond, print the paths it will use
 AS_IF([test "x$consumerd_only" = "xno"],[
 	AS_ECHO()
+	AS_ECHO_N("The lttng command will look for the lttng-sessiond executable at: ")
+	AS_IF([test "$SESSIOND_BIN" = ""],[
+		AS_ECHO_N("`eval eval echo $bindir`")
+		AS_ECHO("/lttng-sessiond")
+	],[
+		AS_ECHO("$SESSIOND_BIN")
+	])
+
+	AS_ECHO()
 	AS_ECHO("The sessiond daemon will look in the following directories: ")
 	AS_ECHO_N("32-bit consumerd executable at: ")
 	AS_IF([test "$CONSUMERD32_BIN" = ""],[
diff --git a/src/bin/lttng/lttng.c b/src/bin/lttng/lttng.c
index 8562144..4097956 100644
--- a/src/bin/lttng/lttng.c
+++ b/src/bin/lttng/lttng.c
@@ -346,35 +346,38 @@ end:
 static int check_sessiond(void)
 {
 	int ret;
-	char *pathname = NULL, *alloc_pathname = NULL;
+	char *pathname = NULL;
 
 	ret = lttng_session_daemon_alive();
 	if (ret == 0) {	/* not alive */
 		/* Try command line option path */
-		if (opt_sessiond_path != NULL) {
-			ret = access(opt_sessiond_path, F_OK | X_OK);
-			if (ret < 0) {
-				ERR("No such file or access denied: %s", opt_sessiond_path);
-				goto end;
-			}
-			pathname = opt_sessiond_path;
-		} else {
-			/* Try LTTNG_SESSIOND_PATH env variable */
+		pathname = opt_sessiond_path;
+
+		/* Try LTTNG_SESSIOND_PATH env variable */
+		if (pathname == NULL) {
 			pathname = getenv(DEFAULT_SESSIOND_PATH_ENV);
 		}
 
-		/* Let's rock and roll */
+		/* Try with configured path */
 		if (pathname == NULL) {
-			ret = asprintf(&alloc_pathname, INSTALL_BIN_PATH "/lttng-sessiond");
-			if (ret < 0) {
-				perror("asprintf spawn sessiond");
-				goto end;
+			if (CONFIG_SESSIOND_BIN[0] != '\0') {
+				pathname = CONFIG_SESSIOND_BIN;
 			}
-			pathname = alloc_pathname;
+		}
+
+		/* Let's rock and roll while trying the default path */
+		if (pathname == NULL) {
+			pathname = INSTALL_BIN_PATH "/lttng-sessiond";
+		}
+
+		/* Check existence and permissions */
+		ret = access(pathname, F_OK | X_OK);
+		if (ret < 0) {
+			ERR("No such file or access denied: %s", pathname);
+			goto end;
 		}
 
 		ret = spawn_sessiond(pathname);
-		free(alloc_pathname);
 		if (ret < 0) {
 			ERR("Problem occurred when starting %s", pathname);
 			goto end;
-- 
1.7.1