modules: store loaded modules in context struct.

* m4/m4private.h (struct m4_module): Add a next pointer.
(struct m4): Add a module list pointer.
* m4/module.c (m4__module_open): Initialise the next pointer and
update the list head when a new module is successfully opened.
(m4_module_next): Replace the ugly libltdl twiddling with a
straight forward module list traversal one-liner!
Add a context parameter. Adjust all callers.

Signed-off-by: Gary V. Vaughan <gary@gnu.org>

6 files changed, 28 insertions, 38 deletions

diff --git a/m4/builtin.c b/m4/builtin.c
index c5107534..b495e5cb 100644
--- a/m4/builtin.c
+++ b/m4/builtin.c
@@ -39,9 +39,9 @@ compare_builtin_name_CB (const void *name, const void *b)
    symbol value, suitable for use in the symbol table or for an
    argument to m4_push_builtin.  */
 m4_symbol_value * M4_GNUC_PURE
-m4_builtin_find_by_name (m4_module *module, const char *name)
+m4_builtin_find_by_name (m4 *context, m4_module *module, const char *name)
 {
-  m4_module *cur = module ? module : m4_module_next (NULL);
+  m4_module *cur = module ? module : m4_module_next (context, NULL);
   m4__builtin *bp;
 
   do
@@ -55,7 +55,7 @@ m4_builtin_find_by_name (m4_module *module, const char *name)
           return token;
         }
     }
-  while (!module && (cur = m4_module_next (cur)));
+  while (!module && (cur = m4_module_next (context, cur)));
 
   return NULL;
 }
@@ -65,9 +65,9 @@ m4_builtin_find_by_name (m4_module *module, const char *name)
    malloc'd symbol value, suitable for use in the symbol table or for
    an argument to m4_push_builtin.  */
 m4_symbol_value * M4_GNUC_PURE
-m4_builtin_find_by_func (m4_module *module, m4_builtin_func *func)
+m4_builtin_find_by_func (m4 *context, m4_module *module, m4_builtin_func *func)
 {
-  m4_module *cur = module ? module : m4_module_next (NULL);
+  m4_module *cur = module ? module : m4_module_next (context, NULL);
   size_t i;
 
   do
@@ -81,7 +81,7 @@ m4_builtin_find_by_func (m4_module *module, m4_builtin_func *func)
             return token;
           }
     }
-  while (!module && (cur = m4_module_next (cur)));
+  while (!module && (cur = m4_module_next (context, cur)));
 
   return 0;
 }
diff --git a/m4/m4module.h b/m4/m4module.h
index 92710a7e..038a428b 100644
--- a/m4/m4module.h
+++ b/m4/m4module.h
@@ -241,7 +241,7 @@ extern void         m4_install_builtins (m4*, m4_module *, const m4_builtin*);
 extern void         m4_install_macros   (m4*, m4_module *, const m4_macro*);
 
 extern const char * m4_get_module_name (const m4_module *);
-extern m4_module *  m4_module_next     (m4_module *);
+extern m4_module *  m4_module_next     (m4*, m4_module *);
 
 
 
@@ -330,8 +330,8 @@ extern void             m4_set_symbol_value_placeholder (m4_symbol_value *,
 
 /* --- BUILTIN MANAGEMENT --- */
 
-extern m4_symbol_value  *m4_builtin_find_by_name (m4_module *, const char *);
-extern m4_symbol_value  *m4_builtin_find_by_func (m4_module *,
+extern m4_symbol_value  *m4_builtin_find_by_name (m4 *, m4_module *, const char *);
+extern m4_symbol_value  *m4_builtin_find_by_func (m4 *, m4_module *,
                                                   m4_builtin_func *);
 
 
diff --git a/m4/m4private.h b/m4/m4private.h
index 916330ca..dbda70ca 100644
--- a/m4/m4private.h
+++ b/m4/m4private.h
@@ -59,6 +59,7 @@ typedef unsigned int bool_bitfield;
 struct m4 {
   m4_symbol_table *     symtab;
   m4_syntax_table *     syntax;
+  m4_module *           modules;
 
   const char *          current_file;   /* Current input file.  */
   int                   current_line;   /* Current input line.  */
@@ -183,6 +184,7 @@ struct m4_module
   m4__builtin *builtins;        /* Sorted array of builtins.  */
   m4_macro *macros;		/* Unsorted array of macros.  */
   size_t builtins_len;          /* Number of builtins.  */
+  m4_module *next;
 };
 
 extern void         m4__module_init (m4 *context);
diff --git a/m4/module.c b/m4/module.c
index db26198a..dce0f5bf 100644
--- a/m4/module.c
+++ b/m4/module.c
@@ -246,26 +246,11 @@ m4__module_interface (lt_dlhandle handle, const char *id_string)
 }
 
 
-/* Return successive loaded modules that pass the interface test registered
-   with the interface id.  */
+/* Return successive loaded modules. */
 m4_module *
-m4_module_next (m4_module *module)
+m4_module_next (m4 *context, m4_module *module)
 {
-  lt_dlhandle handle = module ? module->handle : NULL;
-  assert (iface_id);
-
-  /* Resident modules still show up in the lt_dlhandle_iterate loop
-     after they have been unloaded from m4.  */
-  do
-    {
-      handle = lt_dlhandle_iterate (iface_id, handle);
-      if (!handle)
-        return NULL;
-      module = (m4_module *) lt_dlcaller_get_data (iface_id, handle);
-    }
-  while (!module);
-  assert (module->handle == handle);
-  return module;
+  return module ? module->next : context->modules;
 }
 
 /* Return the first loaded module that passes the registered interface test
@@ -414,6 +399,9 @@ m4__module_open (m4 *context, const char *name, m4_obstack *obs)
           module = (m4_module *) xzalloc (sizeof *module);
           module->name   = xstrdup (name);
           module->handle = handle;
+	  module->next   = context->modules;
+
+	  context->modules = module;
 
           /* clear out any stale errors, since we have to use
              lt_dlerror to distinguish between success and
diff --git a/modules/gnu.c b/modules/gnu.c
index 5c9b0eed..96c75475 100644
--- a/modules/gnu.c
+++ b/modules/gnu.c
@@ -417,7 +417,7 @@ M4BUILTIN_HANDLER (builtin)
           name = M4ARG (2);
           len = M4ARGLEN (2);
           if (len == strlen (name))
-            value = m4_builtin_find_by_name (NULL, name);
+            value = m4_builtin_find_by_name (context, NULL, name);
           if (value)
             {
               m4_push_builtin (context, obs, value);
@@ -435,7 +435,7 @@ M4BUILTIN_HANDLER (builtin)
       name = M4ARG (1);
       len = M4ARGLEN (1);
       if (len == strlen (name))
-        value = m4_builtin_find_by_name (NULL, name);
+        value = m4_builtin_find_by_name (context, NULL, name);
       if (value == NULL)
         {
           if (m4_is_debug_bit (context, M4_DEBUG_TRACE_DEREF))
@@ -1007,7 +1007,7 @@ M4BUILTIN_HANDLER (m4modules)
 {
   /* The expansion of this builtin is a comma separated list of
      loaded modules.  */
-  m4_module *module = m4_module_next (NULL);
+  m4_module *module = m4_module_next (context, NULL);
 
   if (module)
     do
@@ -1015,7 +1015,7 @@ M4BUILTIN_HANDLER (m4modules)
         m4_shipout_string (context, obs, m4_get_module_name (module), SIZE_MAX,
                            true);
 
-        if ((module = m4_module_next (module)))
+        if ((module = m4_module_next (context, module)))
           obstack_1grow (obs, ',');
       }
     while (module);
diff --git a/src/freeze.c b/src/freeze.c
index 5ac913d8..d2e9ea62 100644
--- a/src/freeze.c
+++ b/src/freeze.c
@@ -33,7 +33,7 @@
 static  void  produce_mem_dump          (FILE *, const char *, size_t);
 static  void  produce_resyntax_dump     (m4 *, FILE *);
 static  void  produce_syntax_dump       (FILE *, m4_syntax_table *, char);
-static  void  produce_module_dump       (FILE *, m4_module *);
+static  void  produce_module_dump       (m4 *, FILE *, m4_module *);
 static  void  produce_symbol_dump       (m4 *, FILE *, m4_symbol_table *);
 static  void *dump_symbol_CB            (m4_symbol_table *, const char *,
                                          size_t, m4_symbol *, void *);
@@ -148,17 +148,17 @@ produce_debugmode_state (FILE *file, int flags)
 }
 
 /* The modules must be dumped in the order in which they will be
-   reloaded from the frozen file.  libltdl stores handles in a push
+   reloaded from the frozen file.  We store handles in a push
    down stack, so we need to dump them in the reverse order to that.  */
 static void
-produce_module_dump (FILE *file, m4_module *module)
+produce_module_dump (m4 *context, FILE *file, m4_module *module)
 {
   const char *name = m4_get_module_name (module);
   size_t len = strlen (name);
 
-  module = m4_module_next (module);
+  module = m4_module_next (context, module);
   if (module)
-    produce_module_dump (file, module);
+    produce_module_dump (context, file, module);
 
   xfprintf (file, "M%zu\n", len);
   produce_mem_dump (file, name, len);
@@ -322,7 +322,7 @@ produce_frozen_state (m4 *context, const char *name)
   produce_debugmode_state (file, m4_get_debug_level_opt (context));
 
   /* Dump all loaded modules.  */
-  produce_module_dump (file, m4_module_next (NULL));
+  produce_module_dump (context, file, m4_module_next (context, NULL));
 
   /* Dump all symbols.  */
   produce_symbol_dump (context, file, M4SYMTAB);
@@ -713,7 +713,7 @@ ill-formed frozen file, invalid module %s encountered"),
                                                 string[2], number[2]));
                 module = m4__module_find (string[2]);
               }
-            token = m4_builtin_find_by_name (module, string[1]);
+            token = m4_builtin_find_by_name (context, module, string[1]);
 
             if (token == NULL)
               {