diff options
Diffstat (limited to 'm4/module.c')
| -rw-r--r-- | m4/module.c | 151 |
1 files changed, 75 insertions, 76 deletions
diff --git a/m4/module.c b/m4/module.c index ebedcffe..a2215f0e 100644 --- a/m4/module.c +++ b/m4/module.c @@ -39,10 +39,17 @@ * libdld or lt_dlpreload from libtool if shared libraries are not * available on the host machine. * - * An M4 module will usually define an external symbol called - * `m4_builtin_table'. This symbol points to a table of `m4_builtin'. - * The table is saved as libltdl caller data and each definition therein - * is added to the symbol table. + * An M4 module will usually define an external symbol named after the + * basename of the loadable module: + * + * void + * mymod_LTX_m4_init_module (m4 *context, m4_module *module, + * m4_obstack *obs) + * + * The function is only called the first time the module is included + * and generally uses either `m4_install_builtins' or + * `m4_install_macros' (or both!) to register whatever builtins and + * macros are provided by the module. * * To load a module, call m4_module_load(), which searches for the * module in directories from M4PATH. The search path is initialized @@ -50,20 +57,10 @@ * time default where the modules shipped with M4 itself are installed. * `m4_module_load' returns NULL on failure, or else an opaque module * handle for the newly mapped vm segment containing the module code. - * If the module is not already loaded, m4_module_load() retrieves its - * value for the symbol `m4_builtin_table', which is installed using - * set_module_builtin_table(). - * - * In addition to builtin functions, you can also define static macro - * expansions in the `m4_macro_table' symbol. If you define this symbol - * in your modules, it should be an array of `m4_macro's, mapping macro - * names to the expansion text. Any macros defined in `m4_macro_table' - * are installed into the M4 symbol table with set_module_macro_table(). - * - * Each time a module is loaded, the module function prototyped as - * "M4INIT_HANDLER (<module name>)" is called, if defined. Any value - * stored in OBS by this function becomes the expansion of the macro - * which called it. + * If the module is not already loaded, m4_module_load() the builtins + * and macros registered by `mymod_LTX_m4_init_module' are installed + * into the symbol table using `install_builtin_table' and `install_ + * macro_table' respectively. **/ #define MODULE_SELF_NAME "!myself!" @@ -73,8 +70,9 @@ static const char* module_dlerror (void); static void install_builtin_table (m4*, m4_module *); static void install_macro_table (m4*, m4_module *); -static int m4__module_interface (lt_dlhandle handle, - const char *id_string); +static int compare_builtin_CB (const void *a, const void *b); +static int m4__module_interface (lt_dlhandle handle, + const char *id_string); static lt_dlinterface_id iface_id = NULL; @@ -117,6 +115,36 @@ m4_module_import (m4 *context, const char *module_name, return symbol_address; } +void +m4_install_builtins (m4 *context, m4_module *module, const m4_builtin *bp) +{ + assert (context); + assert (module); + assert (bp); + + const m4_builtin *tmp; + m4__builtin *builtin; + for (tmp = bp; tmp->name; tmp++) + module->builtins_len++; + module->builtins = (m4__builtin *) xnmalloc (module->builtins_len, + sizeof *module->builtins); + for (builtin = module->builtins; bp->name != NULL; bp++, builtin++) + { + /* Sanity check that builtins meet the required interface. */ + assert (bp->min_args <= bp->max_args); + assert (bp->min_args > 0 || + (bp->flags & (M4_BUILTIN_BLIND|M4_BUILTIN_SIDE_EFFECT)) == 0); + assert (bp->max_args || + (bp->flags & M4_BUILTIN_FLATTEN_ARGS) == 0); + assert ((bp->flags & ~M4_BUILTIN_FLAGS_MASK) == 0); + memcpy (&builtin->builtin, bp, sizeof *bp); + builtin->builtin.name = xstrdup (bp->name); + builtin->module = module; + } + qsort (module->builtins, module->builtins_len, + sizeof *module->builtins, compare_builtin_CB); +} + static void install_builtin_table (m4 *context, m4_module *module) { @@ -144,6 +172,16 @@ install_builtin_table (m4 *context, m4_module *module) m4_get_module_name (module)); } +void +m4_install_macros (m4 *context, m4_module *module, const m4_macro *mp) +{ + assert (context); + assert (module); + assert (mp); + + module->macros = (m4_macro *) mp; +} + static void install_macro_table (m4 *context, m4_module *module) { @@ -152,7 +190,7 @@ install_macro_table (m4 *context, m4_module *module) assert (context); assert (module); - mp = (const m4_macro *) lt_dlsym (module->handle, MACRO_SYMBOL); + mp = module->macros; if (mp) { @@ -174,7 +212,7 @@ install_macro_table (m4 *context, m4_module *module) m4_debug_message (context, M4_DEBUG_TRACE_MODULE, _("module %s: macros loaded"), - m4_get_module_name (module)); + m4_get_module_name (module)); } } @@ -209,9 +247,7 @@ m4__module_interface (lt_dlhandle handle, const char *id_string) return 0; /* A valid m4 module must provide at least one of these symbols. */ - return !(lt_dlsym (handle, INIT_SYMBOL) - || lt_dlsym (handle, BUILTIN_SYMBOL) - || lt_dlsym (handle, MACRO_SYMBOL)); + return !(lt_dlsym (handle, INIT_SYMBOL)); } @@ -379,46 +415,10 @@ m4__module_open (m4 *context, const char *name, m4_obstack *obs) { void *old; const char *err; - const m4_builtin *bp; module = (m4_module *) xzalloc (sizeof *module); module->handle = handle; - /* TODO - change module interface to return function pointer - that supplies both table and length of table, rather than - returning data pointer that must have a sentinel - entry? */ - bp = (m4_builtin *) lt_dlsym (module->handle, BUILTIN_SYMBOL); - if (bp) - { - const m4_builtin *tmp; - m4__builtin *builtin; - for (tmp = bp; tmp->name; tmp++) - module->builtins_len++; - module->builtins = - (m4__builtin *) xnmalloc (module->builtins_len, - sizeof *module->builtins); - for (builtin = module->builtins; bp->name != NULL; - bp++, builtin++) - { - /* Sanity check that builtins meet the required - interface. */ - assert (bp->min_args <= bp->max_args); - assert (bp->min_args > 0 - || (bp->flags & (M4_BUILTIN_BLIND - | M4_BUILTIN_SIDE_EFFECT)) == 0); - assert (bp->max_args - || (bp->flags & M4_BUILTIN_FLATTEN_ARGS) == 0); - assert ((bp->flags & ~M4_BUILTIN_FLAGS_MASK) == 0); - - memcpy (&builtin->builtin, bp, sizeof *bp); - builtin->builtin.name = xstrdup (bp->name); - builtin->module = module; - } - } - qsort (module->builtins, module->builtins_len, - sizeof *module->builtins, compare_builtin_CB); - /* clear out any stale errors, since we have to use lt_dlerror to distinguish between success and failure. */ @@ -429,23 +429,22 @@ m4__module_open (m4 *context, const char *name, m4_obstack *obs) if (err) m4_error (context, EXIT_FAILURE, 0, NULL, _("unable to load module `%s': %s"), name, err); - } - /* Find and run any initializing function in the opened module, - each time the module is opened. */ - init_func = (m4_module_init_func *) lt_dlsym (handle, INIT_SYMBOL); - if (init_func) - { - init_func (context, module, obs); + /* Find and run any initializing function in the opened module, + the first time the module is opened. */ + init_func = (m4_module_init_func *) lt_dlsym (handle, INIT_SYMBOL); + if (init_func) + { + init_func (context, module, obs); - m4_debug_message (context, M4_DEBUG_TRACE_MODULE, - _("module %s: init hook called"), name); - } - else if (!lt_dlsym (handle, BUILTIN_SYMBOL) - && !lt_dlsym (handle, MACRO_SYMBOL)) - { - m4_error (context, EXIT_FAILURE, 0, NULL, - _("module `%s' has no entry points"), name); + m4_debug_message (context, M4_DEBUG_TRACE_MODULE, + _("module %s: init hook called"), name); + } + else + { + m4_error (context, EXIT_FAILURE, 0, NULL, + _("module `%s' has no entry point"), name); + } } m4_debug_message (context, M4_DEBUG_TRACE_MODULE, |