/********************************************************************** variable.c - $Author$ $Date$ created at: Tue Apr 19 23:55:15 JST 1994 Copyright (C) 1993-2003 Yukihiro Matsumoto Copyright (C) 2000 Network Applied Communication Laboratory, Inc. Copyright (C) 2000 Information-technology Promotion Agency, Japan **********************************************************************/ #include "ruby.h" #include "env.h" #include "node.h" #include "st.h" #include "util.h" static st_table *rb_global_tbl; st_table *rb_class_tbl; static ID autoload, classpath, tmp_classpath; void Init_var_tables() { rb_global_tbl = st_init_numtable(); rb_class_tbl = st_init_numtable(); autoload = rb_intern("__autoload__"); classpath = rb_intern("__classpath__"); tmp_classpath = rb_intern("__tmp_classpath__"); } struct fc_result { ID name; VALUE klass; VALUE path; VALUE track; struct fc_result *prev; }; static VALUE fc_path(fc, name) struct fc_result *fc; ID name; { VALUE path, tmp; path = rb_str_new2(rb_id2name(name)); while (fc) { if (fc->track == rb_cObject) break; if (ROBJECT(fc->track)->iv_tbl && st_lookup(ROBJECT(fc->track)->iv_tbl, classpath, &tmp)) { tmp = rb_str_dup(tmp); rb_str_cat2(tmp, "::"); rb_str_append(tmp, path); return tmp; } tmp = rb_str_new2(rb_id2name(fc->name)); rb_str_cat2(tmp, "::"); rb_str_append(tmp, path); path = tmp; fc = fc->prev; } return path; } static int fc_i(key, value, res) ID key; VALUE value; struct fc_result *res; { if (!rb_is_const_id(key)) return ST_CONTINUE; if (value == res->klass) { res->path = fc_path(res, key); return ST_STOP; } switch (TYPE(value)) { case T_MODULE: case T_CLASS: if (!RCLASS(value)->iv_tbl) return ST_CONTINUE; else { struct fc_result arg; struct fc_result *list; list = res; while (list) { if (list->track == value) return ST_CONTINUE; list = list->prev; } arg.name = key; arg.path = 0; arg.klass = res->klass; arg.track = value; arg.prev = res; st_foreach(RCLASS(value)->iv_tbl, fc_i, (st_data_t)&arg); if (arg.path) { res->path = arg.path; return ST_STOP; } } break; default: break; } return ST_CONTINUE; } static VALUE find_class_path(klass) VALUE klass; { struct fc_result arg; arg.name = 0; arg.path = 0; arg.klass = klass; arg.track = rb_cObject; arg.prev = 0; if (RCLASS(rb_cObject)->iv_tbl) { st_foreach(RCLASS(rb_cObject)->iv_tbl, fc_i, (st_data_t)&arg); } if (arg.path == 0) { st_foreach(rb_class_tbl, fc_i, (st_data_t)&arg); } if (arg.path) { if (!ROBJECT(klass)->iv_tbl) { ROBJECT(klass)->iv_tbl = st_init_numtable(); } st_insert(ROBJECT(klass)->iv_tbl, classpath, arg.path); st_delete(RCLASS(klass)->iv_tbl, &tmp_classpath, 0); return arg.path; } return Qnil; } static VALUE classname(klass) VALUE klass; { VALUE path = Qnil; klass = rb_class_real(klass); if (!klass) klass = rb_cObject; if (ROBJECT(klass)->iv_tbl) { if (!st_lookup(ROBJECT(klass)->iv_tbl, classpath, &path)) { ID classid = rb_intern("__classid__"); if (!st_lookup(ROBJECT(klass)->iv_tbl, classid, &path)) { return find_class_path(klass); } path = rb_str_new2(rb_id2name(SYM2ID(path))); st_insert(ROBJECT(klass)->iv_tbl, classpath, path); st_delete(RCLASS(klass)->iv_tbl, (st_data_t*)&classid, 0); } if (TYPE(path) != T_STRING) { rb_bug("class path is not set properly"); } return path; } return find_class_path(klass); } /* * call-seq: * mod.name => string * * Returns the name of the module <i>mod</i>. */ VALUE rb_mod_name(mod) VALUE mod; { VALUE path = classname(mod); if (!NIL_P(path)) return rb_str_dup(path); return rb_str_new(0,0); } VALUE rb_class_path(klass) VALUE klass; { VALUE path = classname(klass); if (!NIL_P(path)) return path; if (RCLASS(klass)->iv_tbl && st_lookup(RCLASS(klass)->iv_tbl, tmp_classpath, &path)) { return path; } else { char *s = "Class"; if (TYPE(klass) == T_MODULE) { if (rb_obj_class(klass) == rb_cModule) { s = "Module"; } else { s = rb_class2name(RBASIC(klass)->klass); } } path = rb_str_new(0, 2 + strlen(s) + 3 + 2 * SIZEOF_LONG + 1); sprintf(RSTRING(path)->ptr, "#<%s:0x%lx>", s, klass); RSTRING(path)->len = strlen(RSTRING(path)->ptr); rb_ivar_set(klass, tmp_classpath, path); return path; } } void rb_set_class_path(klass, under, name) VALUE klass, under; const char *name; { VALUE str; if (under == rb_cObject) { str = rb_str_new2(name); } else { str = rb_str_dup(rb_class_path(under)); rb_str_cat2(str, "::"); rb_str_cat2(str, name); } rb_ivar_set(klass, classpath, str); } VALUE rb_path2class(path) const char *path; { const char *pbeg, *p; ID id; VALUE c = rb_cObject; if (path[0] == '#') { rb_raise(rb_eArgError, "can't retrieve anonymous class %s", path); } pbeg = p = path; while (*p) { VALUE str; while (*p && *p != ':') p++; str = rb_str_new(pbeg, p-pbeg); id = rb_intern(RSTRING(str)->ptr); if (p[0] == ':') { if (p[1] != ':') goto undefined_class; p += 2; pbeg = p; } if (!rb_const_defined(c, id)) { undefined_class: rb_raise(rb_eArgError, "undefined class/module %.*s", p-path, path); } c = rb_const_get_at(c, id); switch (TYPE(c)) { case T_MODULE: case T_CLASS: break; default: rb_raise(rb_eTypeError, "%s does not refer class/module", path); } } return c; } void rb_name_class(klass, id) VALUE klass; ID id; { rb_iv_set(klass, "__classid__", ID2SYM(id)); } char * rb_class2name(klass) VALUE klass; { return RSTRING(rb_class_path(klass))->ptr; } char * rb_obj_classname(obj) VALUE obj; { return rb_class2name(CLASS_OF(obj)); } struct trace_var { int removed; void (*func)(); VALUE data; struct trace_var *next; }; struct global_variable { int counter; void *data; VALUE (*getter)(); void (*setter)(); void (*marker)(); int block_trace; struct trace_var *trace; }; struct global_entry { struct global_variable *var; ID id; }; static VALUE undef_getter(); static void undef_setter(); static void undef_marker(); static VALUE val_getter(); static void val_setter(); static void val_marker(); static VALUE var_getter(); static void var_setter(); static void var_marker(); struct global_entry* rb_global_entry(id) ID id; { struct global_entry *entry; if (!st_lookup(rb_global_tbl, id, (st_data_t *)&entry)) { struct global_variable *var; entry = ALLOC(struct global_entry); var = ALLOC(struct global_variable); entry->id = id; entry->var = var; var->counter = 1; var->data = 0; var->getter = undef_getter; var->setter = undef_setter; var->marker = undef_marker; var->block_trace = 0; var->trace = 0; st_add_direct(rb_global_tbl, id, (st_data_t)entry); } return entry; } static VALUE undef_getter(id) ID id; { rb_warning("global variable `%s' not initialized", rb_id2name(id)); return Qnil; } static void undef_setter(val, id, data, var) VALUE val; ID id; void *data; struct global_variable *var; { var->getter = val_getter; var->setter = val_setter; var->marker = val_marker; var->data = (void*)val; } static void undef_marker() { } static VALUE val_getter(id, val) ID id; VALUE val; { return val; } static void val_setter(val, id, data, var) VALUE val; ID id; void *data; struct global_variable *var; { var->data = (void*)val; } static void val_marker(data) VALUE data; { if (data) rb_gc_mark_maybe(data); } static VALUE var_getter(id, var) ID id; VALUE *var; { if (!var) return Qnil; return *var; } static void var_setter(val, id, var) VALUE val; ID id; VALUE *var; { *var = val; } static void var_marker(var) VALUE *var; { if (var) rb_gc_mark_maybe(*var); } static void readonly_setter(val, id, var) VALUE val; ID id; void *var; { rb_name_error(id, "%s is a read-only variable", rb_id2name(id)); } static int mark_global_entry(key, entry) ID key; struct global_entry *entry; { struct trace_var *trace; struct global_variable *var = entry->var; (*var->marker)(var->data); trace = var->trace; while (trace) { if (trace->data) rb_gc_mark_maybe(trace->data); trace = trace->next; } return ST_CONTINUE; } void rb_gc_mark_global_tbl() { st_foreach(rb_global_tbl, mark_global_entry, 0); } static ID global_id(name) const char *name; { ID id; if (name[0] == '$') id = rb_intern(name); else { char *buf = ALLOCA_N(char, strlen(name)+2); buf[0] = '$'; strcpy(buf+1, name); id = rb_intern(buf); } return id; } void rb_define_hooked_variable(name, var, getter, setter) const char *name; VALUE *var; VALUE (*getter)(); void (*setter)(); { struct global_variable *gvar; ID id = global_id(name); gvar = rb_global_entry(id)->var; gvar->data = (void*)var; gvar->getter = getter?getter:var_getter; gvar->setter = setter?setter:var_setter; gvar->marker = var_marker; } void rb_define_variable(name, var) const char *name; VALUE *var; { rb_define_hooked_variable(name, var, 0, 0); } void rb_define_readonly_variable(name, var) const char *name; VALUE *var; { rb_define_hooked_variable(name, var, 0, readonly_setter); } void rb_define_virtual_variable(name, getter, setter) const char *name; VALUE (*getter)(); void (*setter)(); { if (!getter) getter = val_getter; if (!setter) setter = readonly_setter; rb_define_hooked_variable(name, 0, getter, setter); } static void rb_trace_eval(cmd, val) VALUE cmd, val; { rb_eval_cmd(cmd, rb_ary_new3(1, val), 0); } /* * call-seq: * trace_var(symbol, cmd ) => nil * trace_var(symbol) {|val| block } => nil * * Controls tracing of assignments to global variables. The parameter * +symbol_ identifies the variable (as either a string name or a * symbol identifier). _cmd_ (which may be a string or a * +Proc+ object) or block is executed whenever the variable * is assigned. The block or +Proc+ object receives the * variable's new value as a parameter. Also see * <code>Kernel::untrace_var</code>. * * trace_var :$_, proc {|v| puts "$_ is now '#{v}'" } * $_ = "hello" * $_ = ' there' * * <em>produces:</em> * * $_ is now 'hello' * $_ is now ' there' */ VALUE rb_f_trace_var(argc, argv) int argc; VALUE *argv; { VALUE var, cmd; struct global_entry *entry; struct trace_var *trace; rb_secure(4); if (rb_scan_args(argc, argv, "11", &var, &cmd) == 1) { cmd = rb_block_proc(); } if (NIL_P(cmd)) { return rb_f_untrace_var(argc, argv); } entry = rb_global_entry(rb_to_id(var)); if (OBJ_TAINTED(cmd)) { rb_raise(rb_eSecurityError, "Insecure: tainted variable trace"); } trace = ALLOC(struct trace_var); trace->next = entry->var->trace; trace->func = rb_trace_eval; trace->data = cmd; trace->removed = 0; entry->var->trace = trace; return Qnil; } static void remove_trace(var) struct global_variable *var; { struct trace_var *trace = var->trace; struct trace_var t; struct trace_var *next; t.next = trace; trace = &t; while (trace->next) { next = trace->next; if (next->removed) { trace->next = next->next; free(next); } else { trace = next; } } var->trace = t.next; } /* * call-seq: * untrace_var(symbol [, cmd] ) => array or nil * * Removes tracing for the specified command on the given global * variable and returns +nil+. If no command is specified, * removes all tracing for that variable and returns an array * containing the commands actually removed. */ VALUE rb_f_untrace_var(argc, argv) int argc; VALUE *argv; { VALUE var, cmd; ID id; struct global_entry *entry; struct trace_var *trace; rb_scan_args(argc, argv, "11", &var, &cmd); id = rb_to_id(var); if (!st_lookup(rb_global_tbl, id, (st_data_t *)&entry)) { rb_name_error(id, "undefined global variable %s", rb_id2name(id)); } trace = entry->var->trace; if (NIL_P(cmd)) { VALUE ary = rb_ary_new(); while (trace) { struct trace_var *next = trace->next; rb_ary_push(ary, (VALUE)trace->data); trace->removed = 1; trace = next; } if (!entry->var->block_trace) remove_trace(entry->var); return ary; } else { while (trace) { if (trace->data == cmd) { trace->removed = 1; if (!entry->var->block_trace) remove_trace(entry->var); return rb_ary_new3(1, cmd); } trace = trace->next; } } return Qnil; } VALUE rb_gvar_get(entry) struct global_entry *entry; { struct global_variable *var = entry->var; return (*var->getter)(entry->id, var->data, var); } struct trace_data { struct trace_var *trace; VALUE val; }; static VALUE trace_ev(data) struct trace_data *data; { struct trace_var *trace = data->trace; while (trace) { (*trace->func)(trace->data, data->val); trace = trace->next; } return Qnil; /* not reached */ } static VALUE trace_en(var) struct global_variable *var; { var->block_trace = 0; remove_trace(var); return Qnil; /* not reached */ } VALUE rb_gvar_set(entry, val) struct global_entry *entry; VALUE val; { struct trace_data trace; struct global_variable *var = entry->var; if (rb_safe_level() >= 4) rb_raise(rb_eSecurityError, "Insecure: can't change global variable value"); (*var->setter)(val, entry->id, var->data, var); if (var->trace && !var->block_trace) { var->block_trace = 1; trace.trace = var->trace; trace.val = val; rb_ensure(trace_ev, (VALUE)&trace, trace_en, (VALUE)var); } return val; } VALUE rb_gv_set(name, val) const char *name; VALUE val; { struct global_entry *entry; entry = rb_global_entry(global_id(name)); return rb_gvar_set(entry, val); } VALUE rb_gv_get(name) const char *name; { struct global_entry *entry; entry = rb_global_entry(global_id(name)); return rb_gvar_get(entry); } VALUE rb_gvar_defined(entry) struct global_entry *entry; { if (entry->var->getter == undef_getter) return Qfalse; return Qtrue; } static int gvar_i(key, entry, ary) ID key; struct global_entry *entry; VALUE ary; { rb_ary_push(ary, rb_str_new2(rb_id2name(key))); return ST_CONTINUE; } /* * call-seq: * global_variables => array * * Returns an array of the names of global variables. * * global_variables.grep /std/ #=> ["$stderr", "$stdout", "$stdin"] */ VALUE rb_f_global_variables() { VALUE ary = rb_ary_new(); char buf[4]; char *s = "&`'+123456789"; st_foreach(rb_global_tbl, gvar_i, ary); if (!NIL_P(rb_backref_get())) { while (*s) { sprintf(buf, "$%c", *s++); rb_ary_push(ary, rb_str_new2(buf)); } } return ary; } void rb_alias_variable(name1, name2) ID name1; ID name2; { struct global_entry *entry1, *entry2; if (rb_safe_level() >= 4) rb_raise(rb_eSecurityError, "Insecure: can't alias global variable"); entry2 = rb_global_entry(name2); if (!st_lookup(rb_global_tbl, name1, (st_data_t *)&entry1)) { entry1 = ALLOC(struct global_entry); entry1->id = name1; st_add_direct(rb_global_tbl, name1, (st_data_t)entry1); } else if (entry1->var != entry2->var) { struct global_variable *var = entry1->var; if (var->block_trace) { rb_raise(rb_eRuntimeError, "can't alias in tracer"); } var->counter--; if (var->counter == 0) { struct trace_var *trace = var->trace; while (trace) { struct trace_var *next = trace->next; free(trace); trace = next; } free(var); } } else { return; } entry2->var->counter++; entry1->var = entry2->var; } static int special_generic_ivar = 0; static st_table *generic_iv_tbl; st_table* rb_generic_ivar_table(obj) VALUE obj; { st_table *tbl; if (!FL_TEST(obj, FL_EXIVAR)) return 0; if (!generic_iv_tbl) return 0; if (!st_lookup(generic_iv_tbl, obj, (st_data_t *)&tbl)) return 0; return tbl; } static VALUE generic_ivar_get(obj, id) VALUE obj; ID id; { st_table *tbl; VALUE val; if (generic_iv_tbl) { if (st_lookup(generic_iv_tbl, obj, (st_data_t *)&tbl)) { if (st_lookup(tbl, id, &val)) { return val; } } } rb_warning("instance variable %s not initialized", rb_id2name(id)); return Qnil; } static void generic_ivar_set(obj, id, val) VALUE obj; ID id; VALUE val; { st_table *tbl; if (rb_special_const_p(obj)) { special_generic_ivar = 1; } if (!generic_iv_tbl) { generic_iv_tbl = st_init_numtable(); } if (!st_lookup(generic_iv_tbl, obj, (st_data_t *)&tbl)) { FL_SET(obj, FL_EXIVAR); tbl = st_init_numtable(); st_add_direct(generic_iv_tbl, obj, (st_data_t)tbl); st_add_direct(tbl, id, val); return; } st_insert(tbl, id, val); } static VALUE generic_ivar_defined(obj, id) VALUE obj; ID id; { st_table *tbl; VALUE val; if (!generic_iv_tbl) return Qfalse; if (!st_lookup(generic_iv_tbl, obj, (st_data_t *)&tbl)) return Qfalse; if (st_lookup(tbl, id, &val)) { return Qtrue; } return Qfalse; } static int generic_ivar_remove(obj, id, valp) VALUE obj; ID id; VALUE *valp; { st_table *tbl; int status; if (!generic_iv_tbl) return 0; if (!st_lookup(generic_iv_tbl, obj, (st_data_t *)&tbl)) return 0; status = st_delete(tbl, &id, valp); if (tbl->num_entries == 0) { st_delete(generic_iv_tbl, &obj, (st_data_t *)&tbl); st_free_table(tbl); } return status; } void rb_mark_generic_ivar(obj) VALUE obj; { st_table *tbl; if (!generic_iv_tbl) return; if (st_lookup(generic_iv_tbl, obj, (st_data_t *)&tbl)) { rb_mark_tbl(tbl); } } static int givar_mark_i(key, value) ID key; VALUE value; { rb_gc_mark(value); return ST_CONTINUE; } static int givar_i(obj, tbl) VALUE obj; st_table *tbl; { if (rb_special_const_p(obj)) { st_foreach(tbl, givar_mark_i, 0); } return ST_CONTINUE; } void rb_mark_generic_ivar_tbl() { if (!generic_iv_tbl) return; if (special_generic_ivar == 0) return; st_foreach(generic_iv_tbl, givar_i, 0); } void rb_free_generic_ivar(obj) VALUE obj; { st_table *tbl; if (st_delete(generic_iv_tbl, &obj, (st_data_t *)&tbl)) st_free_table(tbl); } void rb_copy_generic_ivar(clone, obj) VALUE clone, obj; { st_table *tbl; if (!generic_iv_tbl) return; if (st_lookup(generic_iv_tbl, obj, (st_data_t *)&tbl)) { st_table *old; if (st_lookup(generic_iv_tbl, clone, (st_data_t *)&old)) { st_free_table(old); st_insert(generic_iv_tbl, clone, (st_data_t)st_copy(tbl)); } else { st_add_direct(generic_iv_tbl, clone, (st_data_t)st_copy(tbl)); } } } static VALUE ivar_get(obj, id, warn) VALUE obj; ID id; int warn; { VALUE val; switch (TYPE(obj)) { case T_OBJECT: case T_CLASS: case T_MODULE: if (ROBJECT(obj)->iv_tbl && st_lookup(ROBJECT(obj)->iv_tbl, id, &val)) return val; break; default: if (FL_TEST(obj, FL_EXIVAR) || rb_special_const_p(obj)) return generic_ivar_get(obj, id); break; } if (warn && ruby_verbose) { rb_warning("instance variable %s not initialized", rb_id2name(id)); } return Qnil; } VALUE rb_ivar_get(obj, id) VALUE obj; ID id; { return ivar_get(obj, id, Qtrue); } VALUE rb_attr_get(obj, id) VALUE obj; ID id; { return ivar_get(obj, id, Qfalse); } VALUE rb_ivar_set(obj, id, val) VALUE obj; ID id; VALUE val; { if (!OBJ_TAINTED(obj) && rb_safe_level() >= 4) rb_raise(rb_eSecurityError, "Insecure: can't modify instance variable"); if (OBJ_FROZEN(obj)) rb_error_frozen("object"); switch (TYPE(obj)) { case T_OBJECT: case T_CLASS: case T_MODULE: if (!ROBJECT(obj)->iv_tbl) ROBJECT(obj)->iv_tbl = st_init_numtable(); st_insert(ROBJECT(obj)->iv_tbl, id, val); break; default: generic_ivar_set(obj, id, val); break; } return val; } VALUE rb_ivar_defined(obj, id) VALUE obj; ID id; { switch (TYPE(obj)) { case T_OBJECT: case T_CLASS: case T_MODULE: if (ROBJECT(obj)->iv_tbl && st_lookup(ROBJECT(obj)->iv_tbl, id, 0)) return Qtrue; break; default: if (FL_TEST(obj, FL_EXIVAR) || rb_special_const_p(obj)) return generic_ivar_defined(obj, id); break; } return Qfalse; } static int ivar_i(key, entry, ary) ID key; struct global_entry *entry; VALUE ary; { if (rb_is_instance_id(key)) { rb_ary_push(ary, rb_str_new2(rb_id2name(key))); } return ST_CONTINUE; } /* * call-seq: * obj.instance_variables => array * * Returns an array of instance variable names for the receiver. Note * that simply defining an accessor does not create the corresponding * instance variable. * * class Fred * attr_accessor :a1 * def initialize * @iv = 3 * end * end * Fred.new.instance_variables #=> ["@iv"] */ VALUE rb_obj_instance_variables(obj) VALUE obj; { VALUE ary; ary = rb_ary_new(); switch (TYPE(obj)) { case T_OBJECT: case T_CLASS: case T_MODULE: if (ROBJECT(obj)->iv_tbl) { st_foreach(ROBJECT(obj)->iv_tbl, ivar_i, ary); } break; default: if (!generic_iv_tbl) break; if (FL_TEST(obj, FL_EXIVAR) || rb_special_const_p(obj)) { st_table *tbl; if (st_lookup(generic_iv_tbl, obj, (st_data_t *)&tbl)) { st_foreach(tbl, ivar_i, ary); } } break; } return ary; } /* * call-seq: * obj.remove_instance_variable(symbol) => obj * * Removes the named instance variable from <i>obj</i>, returning that * variable's value. * * class Dummy * attr_reader :var * def initialize * @var = 99 * end * def remove * remove_instance_variable(:@var) * end * end * d = Dummy.new * d.var #=> 99 * d.remove #=> 99 * d.var #=> nil */ VALUE rb_obj_remove_instance_variable(obj, name) VALUE obj, name; { VALUE val = Qnil; ID id = rb_to_id(name); if (!OBJ_TAINTED(obj) && rb_safe_level() >= 4) rb_raise(rb_eSecurityError, "Insecure: can't modify instance variable"); if (OBJ_FROZEN(obj)) rb_error_frozen("object"); if (!rb_is_instance_id(id)) { rb_name_error(id, "`%s' is not allowed as an instance variable name", rb_id2name(id)); } switch (TYPE(obj)) { case T_OBJECT: case T_CLASS: case T_MODULE: if (ROBJECT(obj)->iv_tbl && st_delete(ROBJECT(obj)->iv_tbl, (st_data_t*)&id, &val)) { return val; } break; default: if (FL_TEST(obj, FL_EXIVAR) || rb_special_const_p(obj)) { if (generic_ivar_remove(obj, id, &val)) { return val; } } break; } rb_name_error(id, "instance variable %s not defined", rb_id2name(id)); return Qnil; /* not reached */ } NORETURN(static void uninitialized_constant _((VALUE, ID))); static void uninitialized_constant(klass, id) VALUE klass; ID id; { if (klass && klass != rb_cObject) rb_name_error(id, "uninitialized constant %s::%s", RSTRING(rb_class_path(klass))->ptr, rb_id2name(id)); else { rb_name_error(id, "uninitialized constant %s", rb_id2name(id)); } } static VALUE const_missing(klass, id) VALUE klass; ID id; { return rb_funcall(klass, rb_intern("const_missing"), 1, ID2SYM(id)); } /* * call-seq: * mod.const_missing(sym) => obj * * Invoked when a reference is made to an undefined constant in * <i>mod</i>. It is passed a symbol for the undefined constant, and * returns a value to be used for that constant. The * following code is a (very bad) example: if reference is made to * an undefined constant, it attempts to load a file whose name is * the lowercase version of the constant (thus class <code>Fred</code> is * assumed to be in file <code>fred.rb</code>). If found, it returns the * value of the loaded class. It therefore implements a perverse * kind of autoload facility. * * def Object.const_missing(name) * @looked_for ||= {} * str_name = name.to_s * raise "Class not found: #{name}" if @looked_for[str_name] * @looked_for[str_name] = 1 * file = str_name.downcase * require file * klass = const_get(name) * return klass if klass * raise "Class not found: #{name}" * end * */ VALUE rb_mod_const_missing(klass, name) VALUE klass, name; { ruby_frame = ruby_frame->prev; /* pop frame for "const_missing" */ uninitialized_constant(klass, rb_to_id(name)); return Qnil; /* not reached */ } static struct st_table * check_autoload_table(av) VALUE av; { Check_Type(av, T_DATA); if (RDATA(av)->dmark != (RUBY_DATA_FUNC)rb_mark_tbl || RDATA(av)->dfree != (RUBY_DATA_FUNC)st_free_table) { rb_raise(rb_eTypeError, "wrong autoload table: %s", RSTRING(rb_inspect(av))->ptr); } return (struct st_table *)DATA_PTR(av); } void rb_autoload(mod, id, file) VALUE mod; ID id; const char *file; { VALUE av, fn; struct st_table *tbl; if (!rb_is_const_id(id)) { rb_raise(rb_eNameError, "autoload must be constant name", rb_id2name(id)); } if (!file || !*file) { rb_raise(rb_eArgError, "empty file name"); } if ((tbl = RCLASS(mod)->iv_tbl) && st_lookup(tbl, id, &av) && av != Qundef) return; rb_const_set(mod, id, Qundef); tbl = RCLASS(mod)->iv_tbl; if (st_lookup(tbl, autoload, &av)) { tbl = check_autoload_table(av); } else { av = Data_Wrap_Struct(rb_cData, rb_mark_tbl, st_free_table, 0); st_add_direct(tbl, autoload, av); DATA_PTR(av) = tbl = st_init_numtable(); } fn = rb_str_new2(file); FL_UNSET(fn, FL_TAINT); OBJ_FREEZE(fn); st_insert(tbl, id, (st_data_t)rb_node_newnode(NODE_MEMO, fn, ruby_safe_level, 0)); } static NODE* autoload_delete(mod, id) VALUE mod; ID id; { VALUE val; st_data_t load = 0; st_delete(RCLASS(mod)->iv_tbl, (st_data_t*)&id, 0); if (st_lookup(RCLASS(mod)->iv_tbl, autoload, &val)) { struct st_table *tbl = check_autoload_table(val); st_delete(tbl, (st_data_t*)&id, &load); if (tbl->num_entries == 0) { DATA_PTR(val) = 0; st_free_table(tbl); id = autoload; if (st_delete(RCLASS(mod)->iv_tbl, (st_data_t*)&id, &val)) { rb_gc_force_recycle(val); } } } return (NODE *)load; } void rb_autoload_load(klass, id) VALUE klass; ID id; { VALUE file; NODE *load = autoload_delete(klass, id); if (!load || !(file = load->nd_lit) || rb_provided(RSTRING(file)->ptr)) { const_missing(klass, id); } rb_require_safe(file, load->nd_nth); } static VALUE autoload_file(mod, id) VALUE mod; ID id; { VALUE val, file; struct st_table *tbl; st_data_t load; if (!st_lookup(RCLASS(mod)->iv_tbl, autoload, &val) || !(tbl = check_autoload_table(val)) || !st_lookup(tbl, id, &load)) { return Qnil; } file = ((NODE *)load)->nd_lit; Check_Type(file, T_STRING); if (!RSTRING(file)->ptr) { rb_raise(rb_eArgError, "empty file name"); } if (!rb_provided(RSTRING(file)->ptr)) { return file; } /* already loaded but not defined */ st_delete(tbl, (st_data_t*)&id, 0); if (!tbl->num_entries) { DATA_PTR(val) = 0; st_free_table(tbl); id = autoload; if (st_delete(RCLASS(mod)->iv_tbl, (st_data_t*)&id, &val)) { rb_gc_force_recycle(val); } } return Qnil; } VALUE rb_autoload_p(mod, id) VALUE mod; ID id; { struct st_table *tbl = RCLASS(mod)->iv_tbl; VALUE val; if (!tbl || !st_lookup(tbl, id, &val) || val != Qundef) { return Qnil; } return autoload_file(mod, id); } static VALUE rb_const_get_0(klass, id, exclude, recurse) VALUE klass; ID id; int exclude, recurse; { VALUE value, tmp; int mod_retry = 0; tmp = klass; retry: while (tmp) { while (RCLASS(tmp)->iv_tbl && st_lookup(RCLASS(tmp)->iv_tbl,id,&value)) { if (value == Qundef) { rb_autoload_load(tmp, id); continue; } if (exclude && tmp == rb_cObject && klass != rb_cObject) { rb_warn("toplevel constant %s referenced by %s::%s", rb_id2name(id), rb_class2name(klass), rb_id2name(id)); } return value; } if (!recurse && klass != rb_cObject) break; tmp = RCLASS(tmp)->super; } if (!exclude && !mod_retry && BUILTIN_TYPE(klass) == T_MODULE) { mod_retry = 1; tmp = rb_cObject; goto retry; } return const_missing(klass, id); } VALUE rb_const_get_from(klass, id) VALUE klass; ID id; { return rb_const_get_0(klass, id, Qtrue, Qtrue); } VALUE rb_const_get(klass, id) VALUE klass; ID id; { return rb_const_get_0(klass, id, Qfalse, Qtrue); } VALUE rb_const_get_at(klass, id) VALUE klass; ID id; { return rb_const_get_0(klass, id, Qtrue, Qfalse); } /* * call-seq: * remove_const(sym) => obj * * Removes the definition of the given constant, returning that * constant's value. Predefined classes and singleton objects (such as * <i>true</i>) cannot be removed. */ VALUE rb_mod_remove_const(mod, name) VALUE mod, name; { ID id = rb_to_id(name); VALUE val; if (!rb_is_const_id(id)) { rb_name_error(id, "`%s' is not allowed as a constant name", rb_id2name(id)); } if (!OBJ_TAINTED(mod) && rb_safe_level() >= 4) rb_raise(rb_eSecurityError, "Insecure: can't remove constant"); if (OBJ_FROZEN(mod)) rb_error_frozen("class/module"); if (RCLASS(mod)->iv_tbl && st_delete(ROBJECT(mod)->iv_tbl, (st_data_t*)&id, &val)) { if (val == Qundef) { autoload_delete(mod, id); val = Qnil; } return val; } if (rb_const_defined_at(mod, id)) { rb_name_error(id, "cannot remove %s::%s", rb_class2name(mod), rb_id2name(id)); } rb_name_error(id, "constant %s::%s not defined", rb_class2name(mod), rb_id2name(id)); return Qnil; /* not reached */ } static int sv_i(key, value, tbl) ID key; VALUE value; st_table *tbl; { if (rb_is_const_id(key)) { if (!st_lookup(tbl, key, 0)) { st_insert(tbl, key, key); } } return ST_CONTINUE; } void* rb_mod_const_at(mod, data) VALUE mod; void *data; { st_table *tbl = data; if (!tbl) { tbl = st_init_numtable(); } if (RCLASS(mod)->iv_tbl) { st_foreach(RCLASS(mod)->iv_tbl, sv_i, (st_data_t)tbl); } return tbl; } void* rb_mod_const_of(mod, data) VALUE mod; void *data; { VALUE tmp = mod; for (;;) { data = rb_mod_const_at(tmp, data); tmp = RCLASS(tmp)->super; if (!tmp) break; if (tmp == rb_cObject && mod != rb_cObject) break; } return data; } static int list_i(key, value, ary) ID key, value; VALUE ary; { rb_ary_push(ary, rb_str_new2(rb_id2name(key))); return ST_CONTINUE; } VALUE rb_const_list(data) void *data; { st_table *tbl = data; VALUE ary; if (!tbl) return rb_ary_new2(0); ary = rb_ary_new2(tbl->num_entries); st_foreach(tbl, list_i, ary); st_free_table(tbl); return ary; } /* * call-seq: * mod.constants => array * * Returns an array of the names of the constants accessible in * <i>mod</i>. This includes the names of constants in any included * modules (example at start of section). */ VALUE rb_mod_constants(mod) VALUE mod; { return rb_const_list(rb_mod_const_of(mod, 0)); } static int rb_const_defined_0(klass, id, exclude, recurse) VALUE klass; ID id; int exclude, recurse; { VALUE value, tmp; int mod_retry = 0; tmp = klass; retry: while (tmp) { if (RCLASS(tmp)->iv_tbl && st_lookup(RCLASS(tmp)->iv_tbl, id, &value)) { if (value == Qundef && NIL_P(autoload_file(klass, id))) return Qfalse; return Qtrue; } if (!recurse && klass != rb_cObject) break; tmp = RCLASS(tmp)->super; } if (!exclude && !mod_retry && BUILTIN_TYPE(klass) == T_MODULE) { mod_retry = 1; tmp = rb_cObject; goto retry; } return Qfalse; } int rb_const_defined_from(klass, id) VALUE klass; ID id; { return rb_const_defined_0(klass, id, Qtrue, Qtrue); } int rb_const_defined(klass, id) VALUE klass; ID id; { return rb_const_defined_0(klass, id, Qfalse, Qtrue); } int rb_const_defined_at(klass, id) VALUE klass; ID id; { return rb_const_defined_0(klass, id, Qtrue, Qfalse); } static void mod_av_set(klass, id, val, isconst) VALUE klass; ID id; VALUE val; int isconst; { char *dest = isconst ? "constant" : "class variable"; if (!OBJ_TAINTED(klass) && rb_safe_level() >= 4) rb_raise(rb_eSecurityError, "Insecure: can't set %s", dest); if (OBJ_FROZEN(klass)) { if (BUILTIN_TYPE(klass) == T_MODULE) { rb_error_frozen("module"); } else { rb_error_frozen("class"); } } if (!RCLASS(klass)->iv_tbl) { RCLASS(klass)->iv_tbl = st_init_numtable(); } else if (isconst) { VALUE value = Qfalse; if (st_lookup(RCLASS(klass)->iv_tbl, id, &value)) { if (value == Qundef) autoload_delete(klass, id); else rb_warn("already initialized %s %s", dest, rb_id2name(id)); } } st_insert(RCLASS(klass)->iv_tbl, id, val); } void rb_const_set(klass, id, val) VALUE klass; ID id; VALUE val; { mod_av_set(klass, id, val, Qtrue); } void rb_define_const(klass, name, val) VALUE klass; const char *name; VALUE val; { ID id = rb_intern(name); if (!rb_is_const_id(id)) { rb_warn("rb_define_const: invalide name `%s' for constant", name); } if (klass == rb_cObject) { rb_secure(4); } rb_const_set(klass, id, val); } void rb_define_global_const(name, val) const char *name; VALUE val; { rb_define_const(rb_cObject, name, val); } static VALUE original_module(c) VALUE c; { if (TYPE(c) == T_ICLASS) return RBASIC(c)->klass; return c; } static void cvar_override_check(id, a) ID id; VALUE a; { VALUE base = original_module(a); a = RCLASS(a)->super; while (a) { if (RCLASS(a)->iv_tbl) { if (st_lookup(RCLASS(a)->iv_tbl,id,0)) { rb_warning("class variable %s of %s is overridden by %s", rb_id2name(id), rb_class2name(original_module(a)), rb_class2name(base)); } } a = RCLASS(a)->super; } } void rb_cvar_set(klass, id, val, warn) VALUE klass; ID id; VALUE val; int warn; { VALUE tmp; tmp = klass; while (tmp) { if (RCLASS(tmp)->iv_tbl && st_lookup(RCLASS(tmp)->iv_tbl,id,0)) { if (OBJ_FROZEN(tmp)) rb_error_frozen("class/module"); if (!OBJ_TAINTED(tmp) && rb_safe_level() >= 4) rb_raise(rb_eSecurityError, "Insecure: can't modify class variable"); if (warn && RTEST(ruby_verbose) && klass != tmp) { rb_warning("already initialized class variable %s", rb_id2name(id)); } st_insert(RCLASS(tmp)->iv_tbl,id,val); if (RTEST(ruby_verbose)) { cvar_override_check(id, tmp); } return; } tmp = RCLASS(tmp)->super; } mod_av_set(klass, id, val, Qfalse); } VALUE rb_cvar_get(klass, id) VALUE klass; ID id; { VALUE value; VALUE tmp; tmp = klass; while (tmp) { if (RCLASS(tmp)->iv_tbl) { if (st_lookup(RCLASS(tmp)->iv_tbl,id,&value)) { if (RTEST(ruby_verbose)) { cvar_override_check(id, tmp); } return value; } } tmp = RCLASS(tmp)->super; } rb_name_error(id,"uninitialized class variable %s in %s", rb_id2name(id), rb_class2name(klass)); return Qnil; /* not reached */ } VALUE rb_cvar_defined(klass, id) VALUE klass; ID id; { VALUE tmp; tmp = klass; while (tmp) { if (RCLASS(tmp)->iv_tbl && st_lookup(RCLASS(tmp)->iv_tbl,id,0)) { return Qtrue; } tmp = RCLASS(tmp)->super; } return Qfalse; } void rb_cv_set(klass, name, val) VALUE klass; const char *name; VALUE val; { ID id = rb_intern(name); if (!rb_is_class_id(id)) { rb_name_error(id, "wrong class variable name %s", name); } rb_cvar_set(klass, id, val, Qfalse); } VALUE rb_cv_get(klass, name) VALUE klass; const char *name; { ID id = rb_intern(name); if (!rb_is_class_id(id)) { rb_name_error(id, "wrong class variable name %s", name); } return rb_cvar_get(klass, id); } void rb_define_class_variable(klass, name, val) VALUE klass; const char *name; VALUE val; { ID id = rb_intern(name); if (!rb_is_class_id(id)) { rb_name_error(id, "wrong class variable name %s", name); } rb_cvar_set(klass, id, val, Qtrue); } static int cv_i(key, value, ary) ID key; VALUE value; VALUE ary; { if (rb_is_class_id(key)) { VALUE kval = rb_str_new2(rb_id2name(key)); if (!rb_ary_includes(ary, kval)) { rb_ary_push(ary, kval); } } return ST_CONTINUE; } /* * call-seq: * mod.class_variables => array * * Returns an array of the names of class variables in <i>mod</i> and * the ancestors of <i>mod</i>. * * class One * @@var1 = 1 * end * class Two < One * @@var2 = 2 * end * One.class_variables #=> ["@@var1"] * Two.class_variables #=> ["@@var2", "@@var1"] */ VALUE rb_mod_class_variables(obj) VALUE obj; { VALUE ary = rb_ary_new(); for (;;) { if (RCLASS(obj)->iv_tbl) { st_foreach(RCLASS(obj)->iv_tbl, cv_i, ary); } obj = RCLASS(obj)->super; if (!obj) break; } return ary; } /* * call-seq: * remove_class_variable(sym) => obj * * Removes the definition of the <i>sym</i>, returning that * constant's value. * * class Dummy * @@var = 99 * puts @@var * remove_class_variable(:@@var) * puts(defined? @@var) * end * * <em>produces:</em> * * 99 * nil */ VALUE rb_mod_remove_cvar(mod, name) VALUE mod, name; { ID id = rb_to_id(name); VALUE val; if (!rb_is_class_id(id)) { rb_name_error(id, "wrong class variable name %s", rb_id2name(id)); } if (!OBJ_TAINTED(mod) && rb_safe_level() >= 4) rb_raise(rb_eSecurityError, "Insecure: can't remove class variable"); if (OBJ_FROZEN(mod)) rb_error_frozen("class/module"); if (RCLASS(mod)->iv_tbl && st_delete(ROBJECT(mod)->iv_tbl, (st_data_t*)&id, &val)) { return val; } if (rb_cvar_defined(mod, id)) { rb_name_error(id, "cannot remove %s for %s", rb_id2name(id), rb_class2name(mod)); } rb_name_error(id, "class variable %s not defined for %s", rb_id2name(id), rb_class2name(mod)); return Qnil; /* not reached */ } VALUE rb_iv_get(obj, name) VALUE obj; const char *name; { ID id = rb_intern(name); return rb_ivar_get(obj, id); } VALUE rb_iv_set(obj, name, val) VALUE obj; const char *name; VALUE val; { ID id = rb_intern(name); return rb_ivar_set(obj, id, val); }