Allow freezing the trace status of macros.

* src/freeze.c (produce_symbol_dump): Let undefined traced macros
through.
(dump_symbol_CB): Also freeze trace state.
* tests/freeze.at (reloading traced macros): New test.
* doc/m4.texinfo (Using frozen files): Update documentation to
mention new state.
(Frozen file format 1): Improve synchronization with branch.
(Frozen file format 2): Reorder directives, and add `d', `t'.
* NEWS: Document this change.

Signed-off-by: Eric Blake <ebb9@byu.net>

1 files changed, 6 insertions, 5 deletions

diff --git a/NEWS b/NEWS
index ea0385bc..6d2624d2 100644
--- a/NEWS
+++ b/NEWS
@@ -195,11 +195,12 @@ promoted to 2.0.
 
 *** The syntax of frozen files format V2 has been improved to save
     additional state.  This includes the `R' directive for default regular
-    expression syntax.  Also, a V2 file can now be represented completely
-    in ASCII, thanks to escape sequences.  Unfortunately, files frozen by
-    M4 1.4q that contain \ in macros cannot be read by 1.9b, but since 1.4q
-    was not widely distributed, this is not expected to be much of an
-    issue, and comes with the territory of using a beta release.
+    expression syntax, the `t' directive for traced macros, and the `d'
+    directive for debug mode.  Also, a V2 file can now be represented
+    completely in ASCII, thanks to escape sequences.  Unfortunately, files
+    frozen by M4 1.4q cannot be read by 1.9b, but since 1.4q was not widely
+    distributed, this is not expected to be much of an issue, and comes
+    with the territory of using a beta release.
   - FIXME: format 2 still needs to catch more missing state; once 2.0 is
     released, any further changes would introduce format 3.