Module#constant_source_location [Feature #10771]

1 files changed, 100 insertions, 0 deletions

diff --git a/object.c b/object.c
index 17964bb5c8..9536cd36f2 100644
--- a/object.c
+++ b/object.c
@@ -2720,6 +2720,105 @@ rb_mod_const_defined(int argc, VALUE *argv, VALUE mod)
     return Qtrue;
 }
 
+static VALUE
+rb_mod_const_source_location(int argc, VALUE *argv, VALUE mod)
+{
+    VALUE name, recur, loc = Qnil;
+    rb_encoding *enc;
+    const char *pbeg, *p, *path, *pend;
+    ID id;
+
+    rb_check_arity(argc, 1, 2);
+    name = argv[0];
+    recur = (argc == 1) ? Qtrue : argv[1];
+
+    if (SYMBOL_P(name)) {
+	if (!rb_is_const_sym(name)) goto wrong_name;
+	id = rb_check_id(&name);
+	if (!id) return Qnil;
+	return RTEST(recur) ? rb_const_source_location(mod, id) : rb_const_source_location_at(mod, id);
+    }
+
+    path = StringValuePtr(name);
+    enc = rb_enc_get(name);
+
+    if (!rb_enc_asciicompat(enc)) {
+	rb_raise(rb_eArgError, "invalid class path encoding (non ASCII)");
+    }
+
+    pbeg = p = path;
+    pend = path + RSTRING_LEN(name);
+
+    if (p >= pend || !*p) {
+      wrong_name:
+	rb_name_err_raise(wrong_constant_name, mod, name);
+    }
+
+    if (p + 2 < pend && p[0] == ':' && p[1] == ':') {
+	mod = rb_cObject;
+	p += 2;
+	pbeg = p;
+    }
+
+    while (p < pend) {
+	VALUE part;
+	long len, beglen;
+
+	while (p < pend && *p != ':') p++;
+
+	if (pbeg == p) goto wrong_name;
+
+	id = rb_check_id_cstr(pbeg, len = p-pbeg, enc);
+	beglen = pbeg-path;
+
+	if (p < pend && p[0] == ':') {
+	    if (p + 2 >= pend || p[1] != ':') goto wrong_name;
+	    p += 2;
+	    pbeg = p;
+	}
+
+	if (!id) {
+	    part = rb_str_subseq(name, beglen, len);
+	    OBJ_FREEZE(part);
+	    if (!rb_is_const_name(part)) {
+		name = part;
+		goto wrong_name;
+	    }
+	    else {
+		return Qnil;
+	    }
+	}
+	if (!rb_is_const_id(id)) {
+	    name = ID2SYM(id);
+	    goto wrong_name;
+	}
+	if (p < pend) {
+	    if (RTEST(recur)) {
+		mod = rb_const_get(mod, id);
+	    }
+	    else {
+		mod = rb_const_get_at(mod, id);
+	    }
+	    if (!RB_TYPE_P(mod, T_MODULE) && !RB_TYPE_P(mod, T_CLASS)) {
+		rb_raise(rb_eTypeError, "%"PRIsVALUE" does not refer to class/module",
+			 QUOTE(name));
+	    }
+	}
+	else {
+	    if (RTEST(recur)) {
+		loc = rb_const_source_location(mod, id);
+	    }
+	    else {
+		loc = rb_const_source_location_at(mod, id);
+	    }
+	    break;
+	}
+	recur = Qfalse;
+    }
+
+    return loc;
+}
+
 /*
  *  call-seq:
  *     obj.instance_variable_get(symbol)    -> obj
@@ -4249,6 +4348,7 @@ InitVM_Object(void)
     rb_define_method(rb_cModule, "const_get", rb_mod_const_get, -1);
     rb_define_method(rb_cModule, "const_set", rb_mod_const_set, 2);
     rb_define_method(rb_cModule, "const_defined?", rb_mod_const_defined, -1);
+    rb_define_method(rb_cModule, "const_source_location", rb_mod_const_source_location, -1);
     rb_define_private_method(rb_cModule, "remove_const",
 			     rb_mod_remove_const, 1); /* in variable.c */
     rb_define_method(rb_cModule, "const_missing",