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, 6 insertions, 3 deletions

diff --git a/daemon/sfdisk.c b/daemon/sfdisk.c
index 8221ffa8..1ce69629 100644
--- a/daemon/sfdisk.c
+++ b/daemon/sfdisk.c
@@ -29,6 +29,9 @@
 #include "daemon.h"
 #include "actions.h"
 
+GUESTFSD_EXT_CMD(str_sfdisk, sfdisk);
+GUESTFSD_EXT_CMD(str_blockdev, blockdev);
+
 static int
 sfdisk (const char *device, int n, int cyls, int heads, int sectors,
         const char *extra_flag,
@@ -38,7 +41,7 @@ sfdisk (const char *device, int n, int cyls, int heads, int sectors,
   char buf[256];
   int i;
 
-  strcpy (buf, "sfdisk");
+  strcpy (buf, str_sfdisk);
 
   if (n > 0)
     sprintf (buf + strlen (buf), " -N %d", n);
@@ -101,7 +104,7 @@ sfdisk (const char *device, int n, int cyls, int heads, int sectors,
    * other component.  In any case, reread the partition table
    * unconditionally here.
    */
-  (void) command (NULL, NULL, "blockdev", "--rereadpt", device, NULL);
+  (void) command (NULL, NULL, str_blockdev, "--rereadpt", device, NULL);
 
   udev_settle ();
 
@@ -136,7 +139,7 @@ sfdisk_flag (const char *device, const char *flag)
   char *out, *err;
   int r;
 
-  r = command (&out, &err, "sfdisk", flag, device, NULL);
+  r = command (&out, &err, str_sfdisk, flag, device, NULL);
   if (r == -1) {
     reply_with_error ("%s: %s", device, err);
     free (out);