guile/libguile/modules.c

/* Copyright 1998,2000-2004,2006-2012,2017-2019
     Free Software Foundation, Inc.

   This file is part of Guile.

   Guile is free software: you can redistribute it and/or modify it
   under the terms of the GNU Lesser General Public License as published
   by the Free Software Foundation, either version 3 of the License, or
   (at your option) any later version.

   Guile is distributed in the hope that it will be useful, but WITHOUT
   ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
   FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
   License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with Guile.  If not, see
   <https://www.gnu.org/licenses/>.  */



#ifdef HAVE_CONFIG_H
# include <config.h>
#endif

#include <stdarg.h>

#include "boolean.h"
#include "deprecation.h"
#include "eval.h"
#include "fluids.h"
#include "gsubr.h"
#include "hashtab.h"
#include "keywords.h"
#include "list.h"
#include "pairs.h"
#include "procprop.h"
#include "smob.h"
#include "struct.h"
#include "symbols.h"
#include "threads.h"
#include "variable.h"
#include "vectors.h"

#include "modules.h"


int scm_module_system_booted_p = 0;

scm_t_bits scm_module_tag;

/* The current module, a fluid. */
static SCM the_module;

/* Most of the module system is implemented in Scheme. These bindings from
   boot-9 are needed to provide the Scheme interface. */
static SCM the_root_module_var;
static SCM module_make_local_var_x_var;
static SCM define_module_star_var;
static SCM process_use_modules_var;
static SCM resolve_module_var;
static SCM module_public_interface_var;
static SCM module_export_x_var;
static SCM default_duplicate_binding_procedures_var;

/* The #:ensure keyword.  */
static SCM k_ensure;


static SCM unbound_variable (const char *func, SCM sym)
{
  scm_error (scm_from_latin1_symbol ("unbound-variable"), func,
             "Unbound variable: ~S", scm_list_1 (sym), SCM_BOOL_F);
}

SCM
scm_the_root_module (void)
{
  if (scm_module_system_booted_p)
    return SCM_VARIABLE_REF (the_root_module_var);
  else
    return SCM_BOOL_F;
}

SCM
scm_i_current_module (scm_thread *thread)
{
  if (scm_module_system_booted_p)
    return scm_i_fluid_ref (thread, the_module);
  else
    return SCM_BOOL_F;
}

SCM_DEFINE (scm_current_module, "current-module", 0, 0, 0,
	    (),
	    "Return the current module.")
#define FUNC_NAME s_scm_current_module
{
  return scm_i_current_module (SCM_I_CURRENT_THREAD);
}
#undef FUNC_NAME

static void scm_post_boot_init_modules (void);

SCM_DEFINE (scm_set_current_module, "set-current-module", 1, 0, 0,
	    (SCM module),
	    "Set the current module to @var{module} and return\n"
	    "the previous current module.")
#define FUNC_NAME s_scm_set_current_module
{
  SCM old;

  if (!scm_module_system_booted_p)
    scm_post_boot_init_modules ();

  SCM_VALIDATE_MODULE (SCM_ARG1, module);

  old = scm_current_module ();
  scm_fluid_set_x (the_module, module);

  return old;
}
#undef FUNC_NAME

SCM_DEFINE (scm_interaction_environment, "interaction-environment", 0, 0, 0,
	    (),
	    "Return a specifier for the environment that contains\n"
	    "implementation--defined bindings, typically a superset of those\n"
	    "listed in the report.  The intent is that this procedure will\n"
	    "return the environment in which the implementation would\n"
	    "evaluate expressions dynamically typed by the user.")
#define FUNC_NAME s_scm_interaction_environment
{
  return scm_current_module ();
}
#undef FUNC_NAME

SCM
scm_c_call_with_current_module (SCM module,
				SCM (*func)(void *), void *data)
{
  return scm_c_with_fluid (the_module, module, func, data);
}

void
scm_dynwind_current_module (SCM module)
{
  scm_dynwind_fluid (the_module, module);
}

/*
  convert "A B C" to scheme list (A B C)
 */
static SCM
convert_module_name (const char *name)
{
  SCM list = SCM_EOL;
  SCM *tail = &list;

  const char *ptr;
  while (*name)
    {
      while (*name == ' ')
	name++;
      ptr = name;
      while (*ptr && *ptr != ' ')
	ptr++;
      if (ptr > name)
	{
	  SCM sym = scm_from_utf8_symboln (name, ptr-name);
	  *tail = scm_cons (sym, SCM_EOL);
	  tail = SCM_CDRLOC (*tail);
	}
      name = ptr;
    }

  return list;
}

SCM
scm_c_resolve_module (const char *name)
{
  return scm_resolve_module (convert_module_name (name));
}

SCM
scm_resolve_module (SCM name)
{
  return scm_call_1 (SCM_VARIABLE_REF (resolve_module_var), name);
}

SCM
scm_maybe_resolve_module (SCM name)
{
  return scm_call_3 (SCM_VARIABLE_REF (resolve_module_var), name,
                     k_ensure, SCM_BOOL_F);
}

SCM
scm_c_define_module (const char *name,
		     void (*init)(void *), void *data)
{
  SCM module = scm_call_1 (SCM_VARIABLE_REF (define_module_star_var),
			   convert_module_name (name));
  if (init)
    scm_c_call_with_current_module (module, (SCM (*)(void*))init, data);
  return module;
}

void
scm_c_use_module (const char *name)
{
  scm_call_1 (SCM_VARIABLE_REF (process_use_modules_var),
	      scm_list_1 (scm_list_1 (convert_module_name (name))));
}

SCM
scm_module_export (SCM module, SCM namelist)
{
  return scm_call_2 (SCM_VARIABLE_REF (module_export_x_var),
		     module, namelist);
}


/*
  @code{scm_c_export}(@var{name-list})

  @code{scm_c_export} exports the named bindings from the current
  module, making them visible to users of the module. This function
  takes a list of string arguments, terminated by NULL, e.g.

  @example
    scm_c_export ("add-double-record", "bamboozle-money", NULL);
  @end example
*/
void
scm_c_export (const char *name, ...)
{
  if (name)
    {
      va_list ap;
      SCM names = scm_cons (scm_from_utf8_symbol (name), SCM_EOL);
      SCM *tail = SCM_CDRLOC (names);
      va_start (ap, name);
      while (1)
	{
	  const char *n = va_arg (ap, const char *);
	  if (n == NULL)
	    break;
	  *tail = scm_cons (scm_from_utf8_symbol (n), SCM_EOL);
	  tail = SCM_CDRLOC (*tail);
	}
      va_end (ap);
      scm_module_export (scm_current_module (), names);
    }
}


/*
 * C level implementation of the standard eval closure
 *
 * This increases loading speed substantially.  The code may be
 * replaced by something based on environments.[ch], in a future
 * release.
 */

/* Return the list of default duplicate binding handlers (procedures).  */
static inline SCM
default_duplicate_binding_handlers (void)
{
  SCM get_handlers;

  get_handlers = SCM_VARIABLE_REF (default_duplicate_binding_procedures_var);

  return (scm_call_0 (get_handlers));
}

/* Each module has an "import obarray" that may be accessed concurrently
   by several threads.  This mutex protects access to any obarray.  This
   is coarse-grain but (1) pthread mutexes are quite cheap, and (2)
   Scheme "programs" have a cache for free variables anyway.  */
static scm_i_pthread_mutex_t import_obarray_mutex =
  SCM_I_PTHREAD_MUTEX_INITIALIZER;

/* Resolve the import of SYM in MODULE, where SYM is currently provided by
   both IFACE1 as VAR1 and IFACE2 as VAR2.  Return the variable chosen by the
   duplicate binding handlers or `#f'.  */
static inline SCM
resolve_duplicate_binding (SCM module, SCM sym,
			   SCM iface1, SCM var1,
			   SCM iface2, SCM var2)
{
  SCM args[8];
  SCM handlers;
  SCM result = SCM_BOOL_F;

  if (scm_is_eq (var1, var2))
    return var1;
  
  args[0] = module;
  args[1] = sym;
  args[2] = iface1;
  args[3] = SCM_VARIABLE_REF (var1);
  if (SCM_UNBNDP (args[3]))
    args[3] = SCM_BOOL_F;
  args[4] = iface2;
  args[5] = SCM_VARIABLE_REF (var2);
  if (SCM_UNBNDP (args[5]))
    args[5] = SCM_BOOL_F;

  scm_i_pthread_mutex_lock (&import_obarray_mutex);
  args[6] = scm_hashq_ref (SCM_MODULE_IMPORT_OBARRAY (module), sym, SCM_BOOL_F);
  scm_i_pthread_mutex_unlock (&import_obarray_mutex);

  args[7] = SCM_BOOL_F;
      
  handlers = SCM_MODULE_DUPLICATE_HANDLERS (module);
  if (scm_is_false (handlers))
    handlers = default_duplicate_binding_handlers ();

  for (; scm_is_pair (handlers); handlers = SCM_CDR (handlers))
    {
      if (scm_is_true (args[6])) 
        {
          args[7] = SCM_VARIABLE_REF (args[6]);
          if (SCM_UNBNDP (args[7]))
            args[7] = SCM_BOOL_F;
        }
      
      result = scm_call_n (SCM_CAR (handlers), args, 8);

      if (scm_is_true (result))
        return result;
    }

  return SCM_BOOL_F;
}

/* No lock is needed for access to this variable, as there are no
   threads before modules are booted.  */
SCM scm_pre_modules_obarray;

/* Lookup SYM as an imported variable of MODULE.  */
static inline SCM
module_imported_variable (SCM module, SCM sym)
{
#define SCM_BOUND_THING_P scm_is_true
  register SCM var, imports;

  /* Search cached imported bindings.  */
  imports = SCM_MODULE_IMPORT_OBARRAY (module);

  scm_i_pthread_mutex_lock (&import_obarray_mutex);
  var = scm_hashq_ref (imports, sym, SCM_UNDEFINED);
  scm_i_pthread_mutex_unlock (&import_obarray_mutex);

  if (SCM_BOUND_THING_P (var))
    return var;

  {
    /* Search the use list for yet uncached imported bindings, possibly
       resolving duplicates as needed and caching the result in the import
       obarray.  */
    SCM uses;
    SCM found_var = SCM_BOOL_F, found_iface = SCM_BOOL_F;

    for (uses = SCM_MODULE_USES (module);
	 scm_is_pair (uses);
	 uses = SCM_CDR (uses))
      {
	SCM iface;

	iface = SCM_CAR (uses);
	var = scm_module_variable (iface, sym);

	if (SCM_BOUND_THING_P (var))
	  {
	    if (SCM_BOUND_THING_P (found_var))
	      {
		/* SYM is a duplicate binding (imported more than once) so we
		   need to resolve it.  */
                found_var = resolve_duplicate_binding (module, sym,
                                                       found_iface, found_var,
                                                       iface, var);

                /* Note that it could be that FOUND_VAR doesn't belong
                   either to FOUND_IFACE or to IFACE, if it was created
                   by merge-generics.  The right thing to do there would
                   be to treat the import obarray as the iface, but the
                   import obarray isn't actually a module.  Oh well.  */
		if (scm_is_eq (found_var, var))
		  found_iface = iface;
	      }
	    else
	      /* Keep track of the variable we found and check for other
		 occurences of SYM in the use list.  */
	      found_var = var, found_iface = iface;
	  }
      }

    if (SCM_BOUND_THING_P (found_var))
      {
	/* Save the lookup result for future reference.  */
        scm_i_pthread_mutex_lock (&import_obarray_mutex);
	(void) scm_hashq_set_x (imports, sym, found_var);
        scm_i_pthread_mutex_unlock (&import_obarray_mutex);
	return found_var;
      }
  }

  return SCM_BOOL_F;
#undef SCM_BOUND_THING_P
}

SCM_DEFINE (scm_module_local_variable, "module-local-variable", 2, 0, 0,
	    (SCM module, SCM sym),
	    "Return the variable bound to @var{sym} in @var{module}.  Return "
	    "@code{#f} is @var{sym} is not bound locally in @var{module}.")
#define FUNC_NAME s_scm_module_local_variable
{
#define SCM_BOUND_THING_P(b) \
  (scm_is_true (b))

  register SCM b;

  if (scm_module_system_booted_p)
    SCM_VALIDATE_MODULE (1, module);

  SCM_VALIDATE_SYMBOL (2, sym);

  if (scm_is_false (module))
    return scm_hashq_ref (scm_pre_modules_obarray, sym, SCM_UNDEFINED);

  /* 1. Check module obarray */
  b = scm_hashq_ref (SCM_MODULE_OBARRAY (module), sym, SCM_UNDEFINED);
  if (SCM_BOUND_THING_P (b))
    return b;

  /* At this point we should just be able to return #f, but there is the
     possibility that a custom binder establishes a mapping for this
     variable.

     However a custom binder should be called only if there is no
     imported binding with the name SYM. So here instead of the order:

       2. Search imported bindings.  In order to be consistent with
          `module-variable', the binder gets called only when no
          imported binding matches SYM.
  
       3. Query the custom binder.

     we first check if there is a binder at all, and if not, just return
     #f directly.
  */

  {
    SCM binder = SCM_MODULE_BINDER (module);

    if (scm_is_true (binder))
      {
        /* 2. */
        b = module_imported_variable (module, sym);
        if (SCM_BOUND_THING_P (b))
          return SCM_BOOL_F;

        /* 3. */
	b = scm_call_3 (binder, module, sym, SCM_BOOL_F);
	if (SCM_BOUND_THING_P (b))
	  return b;
      }
  }

  return SCM_BOOL_F;

#undef SCM_BOUND_THING_P
}
#undef FUNC_NAME

SCM_DEFINE (scm_module_variable, "module-variable", 2, 0, 0,
	    (SCM module, SCM sym),
	    "Return the variable bound to @var{sym} in @var{module}.  This "
	    "may be both a local variable or an imported variable.  Return "
	    "@code{#f} is @var{sym} is not bound in @var{module}.")
#define FUNC_NAME s_scm_module_variable
{
#define SCM_BOUND_THING_P(b) \
  (scm_is_true (b))

  register SCM var;

  if (scm_module_system_booted_p)
    SCM_VALIDATE_MODULE (1, module);

  SCM_VALIDATE_SYMBOL (2, sym);

  if (scm_is_false (module))
    return scm_hashq_ref (scm_pre_modules_obarray, sym, SCM_UNDEFINED);

  /* 1. Check module obarray */
  var = scm_hashq_ref (SCM_MODULE_OBARRAY (module), sym, SCM_UNDEFINED);
  if (SCM_BOUND_THING_P (var))
    return var;

  /* 2. Search among the imported variables.  */
  var = module_imported_variable (module, sym);
  if (SCM_BOUND_THING_P (var))
    return var;

  {
    /* 3. Query the custom binder.  */
    SCM binder;

    binder = SCM_MODULE_BINDER (module);
    if (scm_is_true (binder))
      {
	var = scm_call_3 (binder, module, sym, SCM_BOOL_F);
	if (SCM_BOUND_THING_P (var))
	  return var;
      }
  }

  return SCM_BOOL_F;

#undef SCM_BOUND_THING_P
}
#undef FUNC_NAME

SCM
scm_module_ensure_local_variable (SCM module, SCM sym)
#define FUNC_NAME "module-ensure-local-variable"
{
  if (SCM_LIKELY (scm_module_system_booted_p))
    {
      SCM_VALIDATE_MODULE (1, module);
      SCM_VALIDATE_SYMBOL (2, sym);

      return scm_call_2 (SCM_VARIABLE_REF (module_make_local_var_x_var),
                         module, sym);
    }

  {
    SCM handle, var;

    handle = scm_hashq_create_handle_x (scm_pre_modules_obarray,
                                        sym, SCM_BOOL_F);
    var = SCM_CDR (handle);

    if (scm_is_false (var))
      {
        var = scm_make_variable (SCM_UNDEFINED);
        SCM_SETCDR (handle, var);
      }

    return var;
  }
}
#undef FUNC_NAME

SCM_SYMBOL (sym_macroexpand, "macroexpand");

SCM_DEFINE (scm_module_transformer, "module-transformer", 1, 0, 0,
	    (SCM module),
	    "Returns the syntax expander for the given module.")
#define FUNC_NAME s_scm_module_transformer
{
  if (SCM_UNLIKELY (scm_is_false (module)))
    {
      SCM v = scm_hashq_ref (scm_pre_modules_obarray,
                             sym_macroexpand,
                             SCM_BOOL_F);
      if (scm_is_false (v))
        SCM_MISC_ERROR ("no module, and `macroexpand' unbound", SCM_EOL);
      return SCM_VARIABLE_REF (v);
    }
  else
    {
      SCM_VALIDATE_MODULE (SCM_ARG1, module);
      return SCM_MODULE_TRANSFORMER (module);
    }
}
#undef FUNC_NAME

SCM
scm_current_module_transformer ()
{
  return scm_module_transformer (scm_current_module ());
}

SCM_DEFINE (scm_module_import_interface, "module-import-interface", 2, 0, 0,
	    (SCM module, SCM sym),
	    "Return the module or interface from which @var{sym} is imported "
	    "in @var{module}.  If @var{sym} is not imported (i.e., it is not "
	    "defined in @var{module} or it is a module-local binding instead "
	    "of an imported one), then @code{#f} is returned.")
#define FUNC_NAME s_scm_module_import_interface
{
  SCM var, result = SCM_BOOL_F;

  SCM_VALIDATE_MODULE (1, module);
  SCM_VALIDATE_SYMBOL (2, sym);

  var = scm_module_variable (module, sym);
  if (scm_is_true (var))
    {
      /* Look for the module that provides VAR.  */
      SCM local_var;

      local_var = scm_hashq_ref (SCM_MODULE_OBARRAY (module), sym,
				 SCM_UNDEFINED);
      if (scm_is_eq (local_var, var))
	result = module;
      else
	{
	  /* Look for VAR among the used modules.  */
	  SCM uses, imported_var;

	  for (uses = SCM_MODULE_USES (module);
	       scm_is_pair (uses) && scm_is_false (result);
	       uses = SCM_CDR (uses))
	    {
	      imported_var = scm_module_variable (SCM_CAR (uses), sym);
	      if (scm_is_eq (imported_var, var))
		result = SCM_CAR (uses);
	    }
	}
    }

  return result;
}
#undef FUNC_NAME

SCM
scm_module_public_interface (SCM module)
{
  return scm_call_1 (SCM_VARIABLE_REF (module_public_interface_var), module);
}

SCM
scm_c_module_lookup (SCM module, const char *name)
{
  return scm_module_lookup (module, scm_from_utf8_symbol (name));
}

SCM
scm_module_lookup (SCM module, SCM sym)
#define FUNC_NAME "module-lookup"
{
  SCM var;
  var = scm_module_variable (module, sym);
  if (scm_is_false (var))
    unbound_variable (FUNC_NAME, sym);
  return var;
}
#undef FUNC_NAME

SCM
scm_c_lookup (const char *name)
{
  return scm_lookup (scm_from_utf8_symbol (name));
}

SCM
scm_lookup (SCM sym)
{
  return scm_module_lookup (scm_current_module (), sym);
}

SCM
scm_public_variable (SCM module_name, SCM name)
{
  SCM mod, iface;
  
  mod = scm_maybe_resolve_module (module_name);

  if (scm_is_false (mod))
    scm_misc_error ("public-lookup", "Module named ~s does not exist",
                    scm_list_1 (module_name));
  
  iface = scm_module_public_interface (mod);

  if (scm_is_false (iface))
    scm_misc_error ("public-lookup", "Module ~s has no public interface",
                    scm_list_1 (mod));
  
  return scm_module_variable (iface, name);
}

SCM
scm_private_variable (SCM module_name, SCM name)
{
  SCM mod;
  
  mod = scm_maybe_resolve_module (module_name);

  if (scm_is_false (mod))
    scm_misc_error ("private-lookup", "Module named ~s does not exist",
                    scm_list_1 (module_name));
  
  return scm_module_variable (mod, name);
}

SCM
scm_c_public_variable (const char *module_name, const char *name)
{
  return scm_public_variable (convert_module_name (module_name),
                              scm_from_utf8_symbol (name));
}

SCM
scm_c_private_variable (const char *module_name, const char *name)
{
  return scm_private_variable (convert_module_name (module_name),
                               scm_from_utf8_symbol (name));
}

SCM
scm_public_lookup (SCM module_name, SCM name)
{
  SCM var;
  
  var = scm_public_variable (module_name, name);

  if (scm_is_false (var))
    scm_misc_error ("public-lookup", "No variable bound to ~s in module ~s",
                    scm_list_2 (name, module_name));
  
  return var;
}

SCM
scm_private_lookup (SCM module_name, SCM name)
{
  SCM var;
  
  var = scm_private_variable (module_name, name);

  if (scm_is_false (var))
    scm_misc_error ("private-lookup", "No variable bound to ~s in module ~s",
                    scm_list_2 (name, module_name));
  
  return var;
}

SCM
scm_c_public_lookup (const char *module_name, const char *name)
{
  return scm_public_lookup (convert_module_name (module_name),
                            scm_from_utf8_symbol (name));
}

SCM
scm_c_private_lookup (const char *module_name, const char *name)
{
  return scm_private_lookup (convert_module_name (module_name),
                             scm_from_utf8_symbol (name));
}

SCM
scm_public_ref (SCM module_name, SCM name)
{
  return scm_variable_ref (scm_public_lookup (module_name, name));
}

SCM
scm_private_ref (SCM module_name, SCM name)
{
  return scm_variable_ref (scm_private_lookup (module_name, name));
}

SCM
scm_c_public_ref (const char *module_name, const char *name)
{
  return scm_public_ref (convert_module_name (module_name),
                         scm_from_utf8_symbol (name));
}

SCM
scm_c_private_ref (const char *module_name, const char *name)
{
  return scm_private_ref (convert_module_name (module_name),
                          scm_from_utf8_symbol (name));
}

SCM
scm_c_module_define (SCM module, const char *name, SCM value)
{
  return scm_module_define (module, scm_from_utf8_symbol (name), value);
}

SCM
scm_module_define (SCM module, SCM sym, SCM value)
#define FUNC_NAME "module-define"
{
  SCM var;

  var = scm_module_ensure_local_variable (module, sym);
  SCM_VARIABLE_SET (var, value);

  return var;
}
#undef FUNC_NAME

SCM
scm_c_define (const char *name, SCM value)
{
  return scm_define (scm_from_utf8_symbol (name), value);
}

SCM_DEFINE (scm_define, "define!", 2, 0, 0,
	    (SCM sym, SCM value),
	    "Define @var{sym} to be @var{value} in the current module."
            "Returns the variable itself. Note that this is a procedure, "
            "not a macro.")
#define FUNC_NAME s_scm_define
{
  SCM_VALIDATE_SYMBOL (SCM_ARG1, sym);

  return scm_module_define (scm_current_module (), sym, value);
}
#undef FUNC_NAME

SCM_DEFINE (scm_module_reverse_lookup, "module-reverse-lookup", 2, 0, 0,
	    (SCM module, SCM variable),
	    "Return the symbol under which @var{variable} is bound in "
	    "@var{module} or @var{#f} if @var{variable} is not visible "
	    "from @var{module}.  If @var{module} is @code{#f}, then the "
	    "pre-module obarray is used.")
#define FUNC_NAME s_scm_module_reverse_lookup
{
  SCM obarray;
  long i, n;

  if (scm_is_false (module))
    obarray = scm_pre_modules_obarray;
  else
    {
      SCM_VALIDATE_MODULE (1, module);
      obarray = SCM_MODULE_OBARRAY (module);
    }

  SCM_VALIDATE_VARIABLE (SCM_ARG2, variable);

  if (!SCM_HASHTABLE_P (obarray))
      return SCM_BOOL_F;

  /* XXX - We do not use scm_hash_fold here to avoid searching the
     whole obarray.  We should have a scm_hash_find procedure. */

  n = SCM_HASHTABLE_N_BUCKETS (obarray);
  for (i = 0; i < n; ++i)
    {
      SCM ls = SCM_HASHTABLE_BUCKET (obarray, i), handle;
      while (!scm_is_null (ls))
	{
	  handle = SCM_CAR (ls);

          if (scm_is_eq (SCM_CDR (handle), variable))
            return SCM_CAR (handle);

	  ls = SCM_CDR (ls);
	}
    }

  if (!scm_is_false (module))
    {
      /* Try the `uses' list.  */
      SCM uses = SCM_MODULE_USES (module);
      while (scm_is_pair (uses))
	{
	  SCM sym = scm_module_reverse_lookup (SCM_CAR (uses), variable);
	  if (scm_is_true (sym))
	    return sym;
	  uses = SCM_CDR (uses);
	}
    }

  return SCM_BOOL_F;
}
#undef FUNC_NAME

SCM_DEFINE (scm_get_pre_modules_obarray, "%get-pre-modules-obarray", 0, 0, 0,
	    (),
	    "Return the obarray that is used for all new bindings before "
	    "the module system is booted.  The first call to "
	    "@code{set-current-module} will boot the module system.")
#define FUNC_NAME s_scm_get_pre_modules_obarray
{
  return scm_pre_modules_obarray;
}
#undef FUNC_NAME

SCM_SYMBOL (scm_sym_system_module, "system-module");

void
scm_modules_prehistory ()
{
  scm_pre_modules_obarray = scm_c_make_hash_table (1790);
}

void
scm_init_modules ()
{
#include "modules.x"
  module_make_local_var_x_var = scm_c_define ("module-make-local-var!",
					    SCM_UNDEFINED);
  the_module = scm_make_fluid ();
}

static void
scm_post_boot_init_modules ()
{
  SCM module_type = SCM_VARIABLE_REF (scm_c_lookup ("module-type"));
  scm_module_tag = SCM_UNPACK (module_type) + scm_tc3_struct;

  resolve_module_var = scm_c_lookup ("resolve-module");
  define_module_star_var = scm_c_lookup ("define-module*");
  process_use_modules_var = scm_c_lookup ("process-use-modules");
  module_export_x_var = scm_c_lookup ("module-export!");
  the_root_module_var = scm_c_lookup ("the-root-module");
  default_duplicate_binding_procedures_var = 
    scm_c_lookup ("default-duplicate-binding-procedures");
  module_public_interface_var = scm_c_lookup ("module-public-interface");
  k_ensure = scm_from_utf8_keyword ("ensure");

  scm_module_system_booted_p = 1;
}