FYI: 31-gary-m4_sysval-to-m4-module.patch

[Gary V. Vaughan]

Applied to HEAD.
--
  ())_.  Gary V. Vaughan    gary@(oranda.demon.co.uk|gnu.org)
  ( '/   Research Scientist http://www.oranda.demon.co.uk       ,_())____
  / )=   GNU Hacker         http://www.gnu.org/software/libtool  \'      `&
`(_~)_   Tech' Author       http://sources.redhat.com/autobook   =`---d__/

Index: ChangeLog
from  Gary V. Vaughan  <address@hidden>

        An experiment: There is loads of code in libm4 which should be in
        the m4 module, but is also used by another module. Just because
        some linkers won't cope with calls across dynamic runtime loaded
        objects I initially left the code in libm4.  It will tidy the
        module api immensely if this code moves to the right place, I just
        need to remember to invent a suitable calling mechanism at some
        point.  For now, only modules that are statically linked and
        preloaded will get this treatment, so the only platforms that will
        break are those that require all symbols to be resolved at link
        time.

        * TODO: Reminder that what I am doing could reduce portability
        unless I do something more robust later.
        * m4/m4module.h (m4_sysval): No longer exported from libm4.
        * m4/utility.c (m4_sysval): No longer declared in libm4.
        * modules/Makefile.am: Reformatting.
        * modules/m4.c (m4_sysval): Declare it at place of use.
        * modules/gnu.c (m4_sysval): Import it for use in esyscmd.

Index: TODO
===================================================================
RCS file: /cvsroot/m4/m4/TODO,v
retrieving revision 1.10
diff -u -p -u -r1.10 TODO
--- TODO 16 Jun 2003 10:43:44 -0000 1.10
+++ TODO 24 Jul 2003 11:37:19 -0000
@@ -102,6 +102,20 @@ for any of these ideas or if you have ot
     asked to load a frozen file that requires versions of modules with
     interface versions unsupported by the current release.
 
+  + Some liberties are take with preloaded modules using one another's
+    symbols.  This only works (portably) because the modules that do it
+    (m4.so and gnu.so) are both statically linked into the core.  Need to
+    investigate how this can be supported for any module, on platforms that
+    don't support backlinking.  Maybe exporting symbol name/address pairs
+    into a table maintained by libm4, and only using module symbols through
+    that table in other modules.
+
+  + On a related note, modules should be able to declare that they require
+    other modules to be loaded before they can work -- and the module loader
+    should take care of that.  Should such required modules be fully loaded
+    into the symbol table?  Or merely loaded into memory so that the C level
+    code is callable?
+
   + Setting of the module search path within m4 scripts:
 
        append(__modulepath__, `/some/modules/live/here')
Index: m4/m4module.h
===================================================================
RCS file: /cvsroot/m4/m4/m4/m4module.h,v
retrieving revision 1.58
diff -u -p -u -r1.58 m4module.h
--- m4/m4module.h 23 Jul 2003 16:20:50 -0000 1.58
+++ m4/m4module.h 24 Jul 2003 11:37:19 -0000
@@ -303,10 +303,6 @@ extern void        m4_debug_message_prefix (m4 
        }                                               } M4_STMT_END
 
 
-/* Exit code from last "syscmd" command.  */
-extern int m4_sysval;
-
-
 
 /* --- SYNTAX TABLE DEFINITIONS --- */
 
Index: m4/utility.c
===================================================================
RCS file: /cvsroot/m4/m4/m4/utility.c,v
retrieving revision 1.31
diff -u -p -u -r1.31 utility.c
--- m4/utility.c 23 Jul 2003 16:20:50 -0000 1.31
+++ m4/utility.c 24 Jul 2003 11:37:19 -0000
@@ -26,8 +26,6 @@
 
 static int dumpdef_cmp (const void *s1, const void *s2);
 
-/* Exit code from last "syscmd" command.  */
-int m4_sysval = 0;
 
 
 /* Give friendly warnings if a builtin macro is passed an
Index: modules/Makefile.am
===================================================================
RCS file: /cvsroot/m4/m4/modules/Makefile.am,v
retrieving revision 1.18
diff -u -p -u -r1.18 Makefile.am
--- modules/Makefile.am 30 May 2003 15:13:32 -0000 1.18
+++ modules/Makefile.am 24 Jul 2003 11:37:19 -0000
@@ -40,9 +40,9 @@ if USE_GMP
 pkglibexec_LTLIBRARIES += mpeval.la
 endif
 
-gnu_la_SOURCES = gnu.c
+gnu_la_SOURCES       = gnu.c
 EXTRA_gnu_la_SOURCES = format.c
-gnu_la_LDFLAGS = -module
+gnu_la_LDFLAGS       = -module
 
 load_la_SOURCES = load.c
 load_la_LDFLAGS = -module
@@ -78,4 +78,3 @@ time_la_LDFLAGS = -module
 BUILT_SOURCES = perlxsi.c
 perlxsi.c:
        perl -MExtUtils::Embed -e xsinit -- -o perlxsi.c
-
Index: modules/gnu.c
===================================================================
RCS file: /cvsroot/m4/m4/modules/gnu.c,v
retrieving revision 1.26
diff -u -p -u -r1.26 gnu.c
--- modules/gnu.c 23 Jul 2003 16:20:50 -0000 1.26
+++ modules/gnu.c 24 Jul 2003 11:37:19 -0000
@@ -503,6 +503,9 @@ M4BUILTIN_HANDLER (syncoutput)
 /**
  * esyscmd(SHELL-COMMAND)
  **/
+
+extern int m4_sysval;
+
 M4BUILTIN_HANDLER (esyscmd)
 {
   FILE *pin;
Index: modules/m4.c
===================================================================
RCS file: /cvsroot/m4/m4/modules/m4.c,v
retrieving revision 1.48
diff -u -p -u -r1.48 m4.c
--- modules/m4.c 23 Jul 2003 16:20:50 -0000 1.48
+++ modules/m4.c 24 Jul 2003 11:37:19 -0000
@@ -337,6 +337,10 @@ M4BUILTIN_HANDLER (defn)
 
 /* This section contains macros to handle the builtins "syscmd"
    and "sysval".  */
+
+/* Exit code from last "syscmd" command (also used by gnu module).  */
+int m4_sysval = 0;
+
 M4BUILTIN_HANDLER (syscmd)
 {
   m4_debug_flush_files (context);