daemon: collect list of called external commands

guestfsd calls many different tools. Keeping track of all of them is
error prone. This patch introduces a new helper macro to put the command
string into its own ELF section:

GUESTFSD_EXT_CMD(C_variable, command_name);

This syntax makes it still possible to grep for used command names.

The actual usage of the collected list could be like this:

  objcopy -j .guestfsd_ext_cmds -O binary daemon/guestfsd /dev/stdout |
  tr '\0' '\n' | sort -u

The resulting output will be used to tell mkinitrd which programs to
copy into the initrd.

Signed-off-by: Olaf Hering <olaf@aepfle.de>

RWMJ:
 - Move str_vgchange at request of author.
 - Fix snprintf call in daemon/debug.c

1 files changed, 3 insertions, 1 deletions

diff --git a/daemon/du.c b/daemon/du.c
index 62f11422..4392befb 100644
--- a/daemon/du.c
+++ b/daemon/du.c
@@ -28,6 +28,8 @@
 #include "daemon.h"
 #include "actions.h"
 
+GUESTFSD_EXT_CMD(str_du, du);
+
 int64_t
 do_du (const char *path)
 {
@@ -45,7 +47,7 @@ do_du (const char *path)
 
   pulse_mode_start ();
 
-  r = command (&out, &err, "du", "-s", buf, NULL);
+  r = command (&out, &err, str_du, "-s", buf, NULL);
   free (buf);
   if (r == -1) {
     pulse_mode_cancel ();