wiretap: register most built-in file types from its module.

Remove most of the built-in file types from the table in
wiretap/file_access.c and, instead, have the file types register
themselves, using wtap_register_file_type_subtypes().

This reduces the source code changes needed to add a new file type from
three (add the handler, add the file type to the table in file_access.c,
add a #define for the file type in wiretap/wtap.h) to one (add the
handler).  (It also requires adding the handler's source file to
wiretap/CMakeLists.txt, but that's required in both cases.)

A few remain because the WTAP_FILE_TYPE_SUBTYPE_ #define is used
elsewhere; that needs to be fixed.

Fix the wiretap/CMakefile.txt file to scan k12text.l, as that now
contains a registration routine.  In the process, avoid scanning files
that don't implement a file type and won't ever have a registration
routine.

Add a Lua routine to fetch the total number of file types; we use that
in some code to construct the wtap_filetypes table, which we need to do
in order to continue to have all the values that used to come from the
WTAP_FILE_TYPE_SUBTYPE_ types.

While we're at it, add modelines to a file that lacked them.

1 files changed, 17 insertions, 1 deletions

diff --git a/wiretap/ascendtext.c b/wiretap/ascendtext.c
index a03b313878..420999b149 100644
--- a/wiretap/ascendtext.c
+++ b/wiretap/ascendtext.c
@@ -83,6 +83,10 @@ static gboolean ascend_seek_read(wtap *wth, gint64 seek_off,
         wtap_rec *rec, Buffer *buf,
         int *err, gchar **err_info);
 
+static int ascend_file_type_subtype = -1;
+
+void register_ascend(void);
+
 /* Seeks to the beginning of the next packet, and returns the
    byte offset at which the header for that packet begins.
    Returns -1 on failure. */
@@ -261,7 +265,7 @@ wtap_open_return_val ascend_open(wtap *wth, int *err, gchar **err_info)
         return WTAP_OPEN_NOT_MINE;
     }
 
-    wth->file_type_subtype = WTAP_FILE_TYPE_SUBTYPE_ASCEND;
+    wth->file_type_subtype = ascend_file_type_subtype;
     wth->file_encap = WTAP_ENCAP_ASCEND;
 
     wth->snapshot_length = ASCEND_MAX_PKT_LEN;
@@ -452,3 +456,15 @@ static gboolean ascend_seek_read(wtap *wth, gint64 seek_off,
     }
     return TRUE;
 }
+
+static const struct file_type_subtype_info ascend_info = {
+    "Lucent/Ascend access server trace", "ascend", "txt", NULL,
+    FALSE, FALSE, 0,
+    NULL, NULL, NULL
+};
+
+void register_ascend(void)
+{
+    ascend_file_type_subtype = wtap_register_file_type_subtypes(&ascend_info,
+                                                                WTAP_FILE_TYPE_SUBTYPE_UNKNOWN);
+}