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, 18 insertions, 1 deletions

diff --git a/wiretap/commview.c b/wiretap/commview.c
index 08910dad16..68d04ef76a 100644
--- a/wiretap/commview.c
+++ b/wiretap/commview.c
@@ -89,6 +89,10 @@ static gboolean commview_read_header(commview_header_t *cv_hdr, FILE_T fh,
 static gboolean commview_dump(wtap_dumper *wdh,	const wtap_rec *rec,
 			      const guint8 *pd, int *err, gchar **err_info);
 
+static int commview_file_type_subtype = -1;
+
+void register_commview(void);
+
 wtap_open_return_val commview_open(wtap *wth, int *err, gchar **err_info)
 {
 	commview_header_t cv_hdr;
@@ -122,7 +126,7 @@ wtap_open_return_val commview_open(wtap *wth, int *err, gchar **err_info)
 	wth->subtype_read = commview_read;
 	wth->subtype_seek_read = commview_seek_read;
 
-	wth->file_type_subtype = WTAP_FILE_TYPE_SUBTYPE_COMMVIEW;
+	wth->file_type_subtype = commview_file_type_subtype;
 	wth->file_encap = WTAP_ENCAP_PER_PACKET;
 	wth->file_tsprec = WTAP_TSPREC_USEC;
 
@@ -596,6 +600,19 @@ static gboolean commview_dump(wtap_dumper *wdh,
 	return TRUE;
 }
 
+static const struct file_type_subtype_info commview_info = {
+	"TamoSoft CommView", "commview", "ncf", NULL,
+	FALSE, FALSE, 0,
+	commview_dump_can_write_encap, commview_dump_open, NULL
+};
+
+void register_commview(void)
+{
+	commview_file_type_subtype =
+	    wtap_register_file_type_subtypes(&commview_info,
+	        WTAP_FILE_TYPE_SUBTYPE_UNKNOWN);
+}
+
 /*
  * Editor modelines  -  https://www.wireshark.org/tools/modelines.html
  *