Fresh start

1 files changed, 2371 insertions, 0 deletions

diff --git a/jni/ruby/iseq.c b/jni/ruby/iseq.c
new file mode 100644
index 0000000..1754837
--- /dev/null
+++ b/jni/ruby/iseq.c
@@ -0,0 +1,2371 @@
+/**********************************************************************
+
+  iseq.c -
+
+  $Author: nagachika $
+  created at: 2006-07-11(Tue) 09:00:03 +0900
+
+  Copyright (C) 2006 Koichi Sasada
+
+**********************************************************************/
+
+#include "internal.h"
+#include "ruby/util.h"
+#include "eval_intern.h"
+
+#ifdef HAVE_DLADDR
+# include <dlfcn.h>
+#endif
+
+/* #define RUBY_MARK_FREE_DEBUG 1 */
+#include "gc.h"
+#include "vm_core.h"
+#include "iseq.h"
+
+#include "insns.inc"
+#include "insns_info.inc"
+
+#define ISEQ_MAJOR_VERSION 2
+#define ISEQ_MINOR_VERSION 2
+
+VALUE rb_cISeq;
+
+#define hidden_obj_p(obj) (!SPECIAL_CONST_P(obj) && !RBASIC(obj)->klass)
+
+static inline VALUE
+obj_resurrect(VALUE obj)
+{
+    if (hidden_obj_p(obj)) {
+	switch (BUILTIN_TYPE(obj)) {
+	  case T_STRING:
+	    obj = rb_str_resurrect(obj);
+	    break;
+	  case T_ARRAY:
+	    obj = rb_ary_resurrect(obj);
+	    break;
+	}
+    }
+    return obj;
+}
+
+static void
+compile_data_free(struct iseq_compile_data *compile_data)
+{
+    if (compile_data) {
+	struct iseq_compile_data_storage *cur, *next;
+	cur = compile_data->storage_head;
+	while (cur) {
+	    next = cur->next;
+	    ruby_xfree(cur);
+	    cur = next;
+	}
+	ruby_xfree(compile_data);
+    }
+}
+
+static void
+iseq_free(void *ptr)
+{
+    rb_iseq_t *iseq;
+    RUBY_FREE_ENTER("iseq");
+
+    if (ptr) {
+	int i;
+	iseq = ptr;
+	if (!iseq->orig) {
+	    /* It's possible that strings are freed */
+	    if (0) {
+		RUBY_GC_INFO("%s @ %s\n", RSTRING_PTR(iseq->location.label),
+					  RSTRING_PTR(iseq->location.path));
+	    }
+
+	    RUBY_FREE_UNLESS_NULL(iseq->iseq_encoded);
+	    RUBY_FREE_UNLESS_NULL(iseq->line_info_table);
+	    RUBY_FREE_UNLESS_NULL(iseq->local_table);
+	    RUBY_FREE_UNLESS_NULL(iseq->is_entries);
+	    if (iseq->callinfo_entries) {
+		for (i=0; i<iseq->callinfo_size; i++) {
+		    /* TODO: revisit callinfo data structure */
+		    rb_call_info_kw_arg_t *kw_arg = iseq->callinfo_entries[i].kw_arg;
+		    RUBY_FREE_UNLESS_NULL(kw_arg);
+		}
+		RUBY_FREE_UNLESS_NULL(iseq->callinfo_entries);
+	    }
+	    RUBY_FREE_UNLESS_NULL(iseq->catch_table);
+	    RUBY_FREE_UNLESS_NULL(iseq->param.opt_table);
+	    if (iseq->param.keyword != NULL) {
+		RUBY_FREE_UNLESS_NULL(iseq->param.keyword->default_values);
+		RUBY_FREE_UNLESS_NULL(iseq->param.keyword);
+	    }
+	    compile_data_free(iseq->compile_data);
+	    RUBY_FREE_UNLESS_NULL(iseq->iseq);
+	}
+	ruby_xfree(ptr);
+    }
+    RUBY_FREE_LEAVE("iseq");
+}
+
+static void
+iseq_mark(void *ptr)
+{
+    RUBY_MARK_ENTER("iseq");
+
+    if (ptr) {
+	rb_iseq_t *iseq = ptr;
+
+	RUBY_GC_INFO("%s @ %s\n", RSTRING_PTR(iseq->location.label), RSTRING_PTR(iseq->location.path));
+	RUBY_MARK_UNLESS_NULL(iseq->mark_ary);
+
+	RUBY_MARK_UNLESS_NULL(iseq->location.label);
+	RUBY_MARK_UNLESS_NULL(iseq->location.base_label);
+	RUBY_MARK_UNLESS_NULL(iseq->location.path);
+	RUBY_MARK_UNLESS_NULL(iseq->location.absolute_path);
+
+	RUBY_MARK_UNLESS_NULL((VALUE)iseq->cref_stack);
+	RUBY_MARK_UNLESS_NULL(iseq->klass);
+	RUBY_MARK_UNLESS_NULL(iseq->coverage);
+	RUBY_MARK_UNLESS_NULL(iseq->orig);
+
+	if (iseq->compile_data != 0) {
+	    struct iseq_compile_data *const compile_data = iseq->compile_data;
+	    RUBY_MARK_UNLESS_NULL(compile_data->mark_ary);
+	    RUBY_MARK_UNLESS_NULL(compile_data->err_info);
+	    RUBY_MARK_UNLESS_NULL(compile_data->catch_table_ary);
+	}
+    }
+    RUBY_MARK_LEAVE("iseq");
+}
+
+static size_t
+iseq_memsize(const void *ptr)
+{
+    size_t size = sizeof(rb_iseq_t);
+    const rb_iseq_t *iseq;
+
+    if (ptr) {
+	iseq = ptr;
+	if (!iseq->orig) {
+	    size += iseq->iseq_size * sizeof(VALUE);
+	    size += iseq->line_info_size * sizeof(struct iseq_line_info_entry);
+	    size += iseq->local_table_size * sizeof(ID);
+	    if (iseq->catch_table) {
+		size += iseq_catch_table_bytes(iseq->catch_table->size);
+	    }
+	    size += (iseq->param.opt_num + 1) * sizeof(VALUE);
+	    if (iseq->param.keyword != NULL) {
+		size += sizeof(struct rb_iseq_param_keyword);
+		size += sizeof(VALUE) * (iseq->param.keyword->num - iseq->param.keyword->required_num);
+	    }
+	    size += iseq->is_size * sizeof(union iseq_inline_storage_entry);
+	    size += iseq->callinfo_size * sizeof(rb_call_info_t);
+
+	    if (iseq->compile_data) {
+		struct iseq_compile_data_storage *cur;
+
+		cur = iseq->compile_data->storage_head;
+		while (cur) {
+		    size += cur->size + SIZEOF_ISEQ_COMPILE_DATA_STORAGE;
+		    cur = cur->next;
+		}
+		size += sizeof(struct iseq_compile_data);
+	    }
+	    if (iseq->iseq) {
+		size += iseq->iseq_size * sizeof(VALUE);
+	    }
+	}
+    }
+
+    return size;
+}
+
+static const rb_data_type_t iseq_data_type = {
+    "iseq",
+    {
+	iseq_mark,
+	iseq_free,
+	iseq_memsize,
+    },              /* functions */
+    0, 0,
+    RUBY_TYPED_FREE_IMMEDIATELY | RUBY_TYPED_PROMOTED1 /* start from age == 2 */ | RUBY_TYPED_WB_PROTECTED
+};
+
+static VALUE
+iseq_alloc(VALUE klass)
+{
+    rb_iseq_t *iseq;
+    return TypedData_Make_Struct(klass, rb_iseq_t, &iseq_data_type, iseq);
+}
+
+static rb_iseq_location_t *
+iseq_location_setup(rb_iseq_t *iseq, VALUE path, VALUE absolute_path, VALUE name, VALUE first_lineno)
+{
+    rb_iseq_location_t *loc = &iseq->location;
+    RB_OBJ_WRITE(iseq->self, &loc->path, path);
+    if (RTEST(absolute_path) && rb_str_cmp(path, absolute_path) == 0) {
+	RB_OBJ_WRITE(iseq->self, &loc->absolute_path, path);
+    }
+    else {
+	RB_OBJ_WRITE(iseq->self, &loc->absolute_path, absolute_path);
+    }
+    RB_OBJ_WRITE(iseq->self, &loc->label, name);
+    RB_OBJ_WRITE(iseq->self, &loc->base_label, name);
+    loc->first_lineno = first_lineno;
+    return loc;
+}
+
+#define ISEQ_SET_CREF(iseq, cref) RB_OBJ_WRITE((iseq)->self, &(iseq)->cref_stack, (cref))
+
+static void
+set_relation(rb_iseq_t *iseq, const VALUE parent)
+{
+    const VALUE type = iseq->type;
+    rb_thread_t *th = GET_THREAD();
+    rb_iseq_t *piseq;
+
+    /* set class nest stack */
+    if (type == ISEQ_TYPE_TOP) {
+	/* toplevel is private */
+	RB_OBJ_WRITE(iseq->self, &iseq->cref_stack, NEW_CREF(rb_cObject));
+	iseq->cref_stack->nd_refinements = Qnil;
+	iseq->cref_stack->nd_visi = NOEX_PRIVATE;
+	if (th->top_wrapper) {
+	    NODE *cref = NEW_CREF(th->top_wrapper);
+	    cref->nd_refinements = Qnil;
+	    cref->nd_visi = NOEX_PRIVATE;
+	    RB_OBJ_WRITE(cref, &cref->nd_next, iseq->cref_stack);
+	    ISEQ_SET_CREF(iseq, cref);
+	}
+	iseq->local_iseq = iseq;
+    }
+    else if (type == ISEQ_TYPE_METHOD || type == ISEQ_TYPE_CLASS) {
+	ISEQ_SET_CREF(iseq, NEW_CREF(0)); /* place holder */
+	iseq->cref_stack->nd_refinements = Qnil;
+	iseq->local_iseq = iseq;
+    }
+    else if (RTEST(parent)) {
+	GetISeqPtr(parent, piseq);
+	ISEQ_SET_CREF(iseq, piseq->cref_stack);
+	iseq->local_iseq = piseq->local_iseq;
+    }
+
+    if (RTEST(parent)) {
+	GetISeqPtr(parent, piseq);
+	iseq->parent_iseq = piseq;
+    }
+
+    if (type == ISEQ_TYPE_MAIN) {
+	iseq->local_iseq = iseq;
+    }
+}
+
+void
+rb_iseq_add_mark_object(rb_iseq_t *iseq, VALUE obj)
+{
+    if (!RTEST(iseq->mark_ary)) {
+	RB_OBJ_WRITE(iseq->self, &iseq->mark_ary, rb_ary_tmp_new(3));
+	RBASIC_CLEAR_CLASS(iseq->mark_ary);
+    }
+    rb_ary_push(iseq->mark_ary, obj);
+}
+
+static VALUE
+prepare_iseq_build(rb_iseq_t *iseq,
+		   VALUE name, VALUE path, VALUE absolute_path, VALUE first_lineno,
+		   VALUE parent, enum iseq_type type,
+		   const rb_compile_option_t *option)
+{
+    iseq->type = type;
+    RB_OBJ_WRITE(iseq->self, &iseq->klass, 0);
+    set_relation(iseq, parent);
+
+    name = rb_fstring(name);
+    path = rb_fstring(path);
+    if (RTEST(absolute_path)) absolute_path = rb_fstring(absolute_path);
+    iseq_location_setup(iseq, path, absolute_path, name, first_lineno);
+    if (iseq != iseq->local_iseq) {
+	RB_OBJ_WRITE(iseq->self, &iseq->location.base_label, iseq->local_iseq->location.label);
+    }
+    iseq->defined_method_id = 0;
+    RB_OBJ_WRITE(iseq->self, &iseq->mark_ary, 0);
+
+    iseq->compile_data = ZALLOC(struct iseq_compile_data);
+    RB_OBJ_WRITE(iseq->self, &iseq->compile_data->err_info, Qnil);
+    RB_OBJ_WRITE(iseq->self, &iseq->compile_data->mark_ary, rb_ary_tmp_new(3));
+
+    iseq->compile_data->storage_head = iseq->compile_data->storage_current =
+      (struct iseq_compile_data_storage *)
+	ALLOC_N(char, INITIAL_ISEQ_COMPILE_DATA_STORAGE_BUFF_SIZE +
+		SIZEOF_ISEQ_COMPILE_DATA_STORAGE);
+
+    RB_OBJ_WRITE(iseq->self, &iseq->compile_data->catch_table_ary, rb_ary_new());
+    iseq->compile_data->storage_head->pos = 0;
+    iseq->compile_data->storage_head->next = 0;
+    iseq->compile_data->storage_head->size =
+      INITIAL_ISEQ_COMPILE_DATA_STORAGE_BUFF_SIZE;
+    iseq->compile_data->option = option;
+    iseq->compile_data->last_coverable_line = -1;
+
+    RB_OBJ_WRITE(iseq->self, &iseq->coverage, Qfalse);
+    if (!GET_THREAD()->parse_in_eval) {
+	VALUE coverages = rb_get_coverages();
+	if (RTEST(coverages)) {
+	    RB_OBJ_WRITE(iseq->self, &iseq->coverage, rb_hash_lookup(coverages, path));
+	    if (NIL_P(iseq->coverage)) RB_OBJ_WRITE(iseq->self, &iseq->coverage, Qfalse);
+	}
+    }
+
+    return Qtrue;
+}
+
+static VALUE
+cleanup_iseq_build(rb_iseq_t *iseq)
+{
+    struct iseq_compile_data *data = iseq->compile_data;
+    VALUE err = data->err_info;
+    iseq->compile_data = 0;
+    compile_data_free(data);
+
+    if (RTEST(err)) {
+	rb_funcall2(err, rb_intern("set_backtrace"), 1, &iseq->location.path);
+	rb_exc_raise(err);
+    }
+    return Qtrue;
+}
+
+static rb_compile_option_t COMPILE_OPTION_DEFAULT = {
+    OPT_INLINE_CONST_CACHE, /* int inline_const_cache; */
+    OPT_PEEPHOLE_OPTIMIZATION, /* int peephole_optimization; */
+    OPT_TAILCALL_OPTIMIZATION, /* int tailcall_optimization */
+    OPT_SPECIALISED_INSTRUCTION, /* int specialized_instruction; */
+    OPT_OPERANDS_UNIFICATION, /* int operands_unification; */
+    OPT_INSTRUCTIONS_UNIFICATION, /* int instructions_unification; */
+    OPT_STACK_CACHING, /* int stack_caching; */
+    OPT_TRACE_INSTRUCTION, /* int trace_instruction */
+};
+static const rb_compile_option_t COMPILE_OPTION_FALSE = {0};
+
+static void
+make_compile_option(rb_compile_option_t *option, VALUE opt)
+{
+    if (opt == Qnil) {
+	*option = COMPILE_OPTION_DEFAULT;
+    }
+    else if (opt == Qfalse) {
+	*option = COMPILE_OPTION_FALSE;
+    }
+    else if (opt == Qtrue) {
+	int i;
+	for (i = 0; i < (int)(sizeof(rb_compile_option_t) / sizeof(int)); ++i)
+	    ((int *)option)[i] = 1;
+    }
+    else if (CLASS_OF(opt) == rb_cHash) {
+	*option = COMPILE_OPTION_DEFAULT;
+
+#define SET_COMPILE_OPTION(o, h, mem) \
+  { VALUE flag = rb_hash_aref((h), ID2SYM(rb_intern(#mem))); \
+      if (flag == Qtrue)  { (o)->mem = 1; } \
+      else if (flag == Qfalse)  { (o)->mem = 0; } \
+  }
+#define SET_COMPILE_OPTION_NUM(o, h, mem) \
+  { VALUE num = rb_hash_aref(opt, ID2SYM(rb_intern(#mem))); \
+      if (!NIL_P(num)) (o)->mem = NUM2INT(num); \
+  }
+	SET_COMPILE_OPTION(option, opt, inline_const_cache);
+	SET_COMPILE_OPTION(option, opt, peephole_optimization);
+	SET_COMPILE_OPTION(option, opt, tailcall_optimization);
+	SET_COMPILE_OPTION(option, opt, specialized_instruction);
+	SET_COMPILE_OPTION(option, opt, operands_unification);
+	SET_COMPILE_OPTION(option, opt, instructions_unification);
+	SET_COMPILE_OPTION(option, opt, stack_caching);
+	SET_COMPILE_OPTION(option, opt, trace_instruction);
+	SET_COMPILE_OPTION_NUM(option, opt, debug_level);
+#undef SET_COMPILE_OPTION
+#undef SET_COMPILE_OPTION_NUM
+    }
+    else {
+	rb_raise(rb_eTypeError, "Compile option must be Hash/true/false/nil");
+    }
+}
+
+static VALUE
+make_compile_option_value(rb_compile_option_t *option)
+{
+    VALUE opt = rb_hash_new();
+#define SET_COMPILE_OPTION(o, h, mem) \
+  rb_hash_aset((h), ID2SYM(rb_intern(#mem)), (o)->mem ? Qtrue : Qfalse)
+#define SET_COMPILE_OPTION_NUM(o, h, mem) \
+  rb_hash_aset((h), ID2SYM(rb_intern(#mem)), INT2NUM((o)->mem))
+    {
+	SET_COMPILE_OPTION(option, opt, inline_const_cache);
+	SET_COMPILE_OPTION(option, opt, peephole_optimization);
+	SET_COMPILE_OPTION(option, opt, tailcall_optimization);
+	SET_COMPILE_OPTION(option, opt, specialized_instruction);
+	SET_COMPILE_OPTION(option, opt, operands_unification);
+	SET_COMPILE_OPTION(option, opt, instructions_unification);
+	SET_COMPILE_OPTION(option, opt, stack_caching);
+	SET_COMPILE_OPTION(option, opt, trace_instruction);
+	SET_COMPILE_OPTION_NUM(option, opt, debug_level);
+    }
+#undef SET_COMPILE_OPTION
+#undef SET_COMPILE_OPTION_NUM
+    return opt;
+}
+
+VALUE
+rb_iseq_new(NODE *node, VALUE name, VALUE path, VALUE absolute_path,
+	    VALUE parent, enum iseq_type type)
+{
+    return rb_iseq_new_with_opt(node, name, path, absolute_path, INT2FIX(0), parent, type,
+				&COMPILE_OPTION_DEFAULT);
+}
+
+VALUE
+rb_iseq_new_top(NODE *node, VALUE name, VALUE path, VALUE absolute_path, VALUE parent)
+{
+    return rb_iseq_new_with_opt(node, name, path, absolute_path, INT2FIX(0), parent, ISEQ_TYPE_TOP,
+				&COMPILE_OPTION_DEFAULT);
+}
+
+VALUE
+rb_iseq_new_main(NODE *node, VALUE path, VALUE absolute_path)
+{
+    rb_thread_t *th = GET_THREAD();
+    VALUE parent = th->base_block->iseq->self;
+    return rb_iseq_new_with_opt(node, rb_str_new2("<main>"), path, absolute_path, INT2FIX(0),
+				parent, ISEQ_TYPE_MAIN, &COMPILE_OPTION_DEFAULT);
+}
+
+VALUE
+rb_iseq_new_with_opt(NODE *node, VALUE name, VALUE path, VALUE absolute_path,
+		     VALUE first_lineno, VALUE parent, enum iseq_type type,
+		     const rb_compile_option_t *option)
+{
+    /* TODO: argument check */
+    rb_iseq_t *iseq;
+    VALUE self = iseq_alloc(rb_cISeq);
+
+    GetISeqPtr(self, iseq);
+    iseq->self = self;
+
+    if (!option) option = &COMPILE_OPTION_DEFAULT;
+    prepare_iseq_build(iseq, name, path, absolute_path, first_lineno, parent,
+		       type, option);
+
+    rb_iseq_compile_node(self, node);
+    cleanup_iseq_build(iseq);
+    return self;
+}
+
+#define CHECK_ARRAY(v)   rb_convert_type((v), T_ARRAY, "Array", "to_ary")
+#define CHECK_HASH(v)    rb_convert_type((v), T_HASH, "Hash", "to_hash")
+#define CHECK_STRING(v)  rb_convert_type((v), T_STRING, "String", "to_str")
+#define CHECK_SYMBOL(v)  rb_convert_type((v), T_SYMBOL, "Symbol", "to_sym")
+static inline VALUE CHECK_INTEGER(VALUE v) {(void)NUM2LONG(v); return v;}
+
+static enum iseq_type
+iseq_type_from_sym(VALUE type)
+{
+    const ID id_top = rb_intern("top");
+    const ID id_method = rb_intern("method");
+    const ID id_block = rb_intern("block");
+    const ID id_class = rb_intern("class");
+    const ID id_rescue = rb_intern("rescue");
+    const ID id_ensure = rb_intern("ensure");
+    const ID id_eval = rb_intern("eval");
+    const ID id_main = rb_intern("main");
+    const ID id_defined_guard = rb_intern("defined_guard");
+    /* ensure all symbols are static or pinned down before
+     * conversion */
+    const ID typeid = rb_check_id(&type);
+    if (typeid == id_top) return ISEQ_TYPE_TOP;
+    if (typeid == id_method) return ISEQ_TYPE_METHOD;
+    if (typeid == id_block) return ISEQ_TYPE_BLOCK;
+    if (typeid == id_class) return ISEQ_TYPE_CLASS;
+    if (typeid == id_rescue) return ISEQ_TYPE_RESCUE;
+    if (typeid == id_ensure) return ISEQ_TYPE_ENSURE;
+    if (typeid == id_eval) return ISEQ_TYPE_EVAL;
+    if (typeid == id_main) return ISEQ_TYPE_MAIN;
+    if (typeid == id_defined_guard) return ISEQ_TYPE_DEFINED_GUARD;
+    return (enum iseq_type)-1;
+}
+
+static VALUE
+iseq_load(VALUE self, VALUE data, VALUE parent, VALUE opt)
+{
+    VALUE iseqval = iseq_alloc(self);
+
+    VALUE magic, version1, version2, format_type, misc;
+    VALUE name, path, absolute_path, first_lineno;
+    VALUE type, body, locals, params, exception;
+
+    st_data_t iseq_type;
+    rb_iseq_t *iseq;
+    rb_compile_option_t option;
+    int i = 0;
+
+    /* [magic, major_version, minor_version, format_type, misc,
+     *  label, path, first_lineno,
+     *  type, locals, args, exception_table, body]
+     */
+
+    data        = CHECK_ARRAY(data);
+
+    magic       = CHECK_STRING(rb_ary_entry(data, i++));
+    version1    = CHECK_INTEGER(rb_ary_entry(data, i++));
+    version2    = CHECK_INTEGER(rb_ary_entry(data, i++));
+    format_type = CHECK_INTEGER(rb_ary_entry(data, i++));
+    misc        = CHECK_HASH(rb_ary_entry(data, i++));
+    ((void)magic, (void)version1, (void)version2, (void)format_type);
+
+    name        = CHECK_STRING(rb_ary_entry(data, i++));
+    path        = CHECK_STRING(rb_ary_entry(data, i++));
+    absolute_path = rb_ary_entry(data, i++);
+    absolute_path = NIL_P(absolute_path) ? Qnil : CHECK_STRING(absolute_path);
+    first_lineno = CHECK_INTEGER(rb_ary_entry(data, i++));
+
+    type        = CHECK_SYMBOL(rb_ary_entry(data, i++));
+    locals      = CHECK_ARRAY(rb_ary_entry(data, i++));
+    params      = CHECK_HASH(rb_ary_entry(data, i++));
+    exception   = CHECK_ARRAY(rb_ary_entry(data, i++));
+    body        = CHECK_ARRAY(rb_ary_entry(data, i++));
+
+    GetISeqPtr(iseqval, iseq);
+    iseq->self = iseqval;
+    iseq->local_iseq = iseq;
+
+    iseq_type = iseq_type_from_sym(type);
+    if (iseq_type == (enum iseq_type)-1) {
+	rb_raise(rb_eTypeError, "unsupport type: :%"PRIsVALUE, rb_sym2str(type));
+    }
+
+    if (parent == Qnil) {
+	parent = 0;
+    }
+
+    make_compile_option(&option, opt);
+
+    prepare_iseq_build(iseq, name, path, absolute_path, first_lineno,
+		       parent, (enum iseq_type)iseq_type, &option);
+
+    rb_iseq_build_from_ary(iseq, misc, locals, params, exception, body);
+
+    cleanup_iseq_build(iseq);
+    return iseqval;
+}
+
+/*
+ * :nodoc:
+ */
+static VALUE
+iseq_s_load(int argc, VALUE *argv, VALUE self)
+{
+    VALUE data, opt=Qnil;
+    rb_scan_args(argc, argv, "11", &data, &opt);
+
+    return iseq_load(self, data, 0, opt);
+}
+
+VALUE
+rb_iseq_load(VALUE data, VALUE parent, VALUE opt)
+{
+    return iseq_load(rb_cISeq, data, parent, opt);
+}
+
+VALUE
+rb_iseq_compile_with_option(VALUE src, VALUE file, VALUE absolute_path, VALUE line, rb_block_t *base_block, VALUE opt)
+{
+    int state;
+    rb_thread_t *th = GET_THREAD();
+    rb_block_t *prev_base_block = th->base_block;
+    VALUE iseqval = Qundef;
+
+    th->base_block = base_block;
+
+    TH_PUSH_TAG(th);
+    if ((state = EXEC_TAG()) == 0) {
+	VALUE parser;
+	int ln = NUM2INT(line);
+	NODE *node;
+	rb_compile_option_t option;
+
+	StringValueCStr(file);
+	make_compile_option(&option, opt);
+
+	parser = rb_parser_new();
+
+	if (RB_TYPE_P((src), T_FILE))
+	    node = rb_parser_compile_file_path(parser, file, src, ln);
+	else {
+	    StringValue(src);
+	    node = rb_parser_compile_string_path(parser, file, src, ln);
+
+	    if (!node) {
+		rb_exc_raise(GET_THREAD()->errinfo);	/* TODO: check err */
+	    }
+	}
+
+	if (base_block && base_block->iseq) {
+	    iseqval = rb_iseq_new_with_opt(node, base_block->iseq->location.label,
+					   file, absolute_path, line, base_block->iseq->self,
+					   ISEQ_TYPE_EVAL, &option);
+	}
+	else {
+	    iseqval = rb_iseq_new_with_opt(node, rb_str_new2("<compiled>"), file, absolute_path, line, Qfalse,
+					   ISEQ_TYPE_TOP, &option);
+	}
+    }
+    TH_POP_TAG();
+
+    th->base_block = prev_base_block;
+
+    if (state) {
+	JUMP_TAG(state);
+    }
+
+    return iseqval;
+}
+
+VALUE
+rb_iseq_compile(VALUE src, VALUE file, VALUE line)
+{
+    return rb_iseq_compile_with_option(src, file, Qnil, line, 0, Qnil);
+}
+
+VALUE
+rb_iseq_compile_on_base(VALUE src, VALUE file, VALUE line, rb_block_t *base_block)
+{
+    return rb_iseq_compile_with_option(src, file, Qnil, line, base_block, Qnil);
+}
+
+/*
+ *  call-seq:
+ *     InstructionSequence.compile(source[, file[, path[, line[, options]]]]) -> iseq
+ *     InstructionSequence.new(source[, file[, path[, line[, options]]]]) -> iseq
+ *
+ *  Takes +source+, a String of Ruby code and compiles it to an
+ *  InstructionSequence.
+ *
+ *  Optionally takes +file+, +path+, and +line+ which describe the filename,
+ *  absolute path and first line number of the ruby code in +source+ which are
+ *  metadata attached to the returned +iseq+.
+ *
+ *  +options+, which can be +true+, +false+ or a +Hash+, is used to
+ *  modify the default behavior of the Ruby iseq compiler.
+ *
+ *  For details regarding valid compile options see ::compile_option=.
+ *
+ *     RubyVM::InstructionSequence.compile("a = 1 + 2")
+ *     #=> <RubyVM::InstructionSequence:<compiled>@<compiled>>
+ *
+ */
+static VALUE
+iseq_s_compile(int argc, VALUE *argv, VALUE self)
+{
+    VALUE src, file = Qnil, path = Qnil, line = INT2FIX(1), opt = Qnil;
+
+    rb_secure(1);
+
+    rb_scan_args(argc, argv, "14", &src, &file, &path, &line, &opt);
+    if (NIL_P(file)) file = rb_str_new2("<compiled>");
+    if (NIL_P(line)) line = INT2FIX(1);
+
+    return rb_iseq_compile_with_option(src, file, path, line, 0, opt);
+}
+
+/*
+ *  call-seq:
+ *      InstructionSequence.compile_file(file[, options]) -> iseq
+ *
+ *  Takes +file+, a String with the location of a Ruby source file, reads,
+ *  parses and compiles the file, and returns +iseq+, the compiled
+ *  InstructionSequence with source location metadata set.
+ *
+ *  Optionally takes +options+, which can be +true+, +false+ or a +Hash+, to
+ *  modify the default behavior of the Ruby iseq compiler.
+ *
+ *  For details regarding valid compile options see ::compile_option=.
+ *
+ *      # /tmp/hello.rb
+ *      puts "Hello, world!"
+ *
+ *      # elsewhere
+ *      RubyVM::InstructionSequence.compile_file("/tmp/hello.rb")
+ *      #=> <RubyVM::InstructionSequence:<main>@/tmp/hello.rb>
+ */
+static VALUE
+iseq_s_compile_file(int argc, VALUE *argv, VALUE self)
+{
+    VALUE file, line = INT2FIX(1), opt = Qnil;
+    VALUE parser;
+    VALUE f;
+    NODE *node;
+    const char *fname;
+    rb_compile_option_t option;
+
+    rb_secure(1);
+    rb_scan_args(argc, argv, "11", &file, &opt);
+    FilePathValue(file);
+    fname = StringValueCStr(file);
+
+    f = rb_file_open_str(file, "r");
+
+    parser = rb_parser_new();
+    node = rb_parser_compile_file(parser, fname, f, NUM2INT(line));
+
+    rb_io_close(f);
+
+    make_compile_option(&option, opt);
+    return rb_iseq_new_with_opt(node, rb_str_new2("<main>"), file,
+				rb_realpath_internal(Qnil, file, 1), line, Qfalse,
+				ISEQ_TYPE_TOP, &option);
+}
+
+/*
+ *  call-seq:
+ *     InstructionSequence.compile_option = options
+ *
+ *  Sets the default values for various optimizations in the Ruby iseq
+ *  compiler.
+ *
+ *  Possible values for +options+ include +true+, which enables all options,
+ *  +false+ which disables all options, and +nil+ which leaves all options
+ *  unchanged.
+ *
+ *  You can also pass a +Hash+ of +options+ that you want to change, any
+ *  options not present in the hash will be left unchanged.
+ *
+ *  Possible option names (which are keys in +options+) which can be set to
+ *  +true+ or +false+ include:
+ *
+ *  * +:inline_const_cache+
+ *  * +:instructions_unification+
+ *  * +:operands_unification+
+ *  * +:peephole_optimization+
+ *  * +:specialized_instruction+
+ *  * +:stack_caching+
+ *  * +:tailcall_optimization+
+ *  * +:trace_instruction+
+ *
+ *  Additionally, +:debug_level+ can be set to an integer.
+ *
+ *  These default options can be overwritten for a single run of the iseq
+ *  compiler by passing any of the above values as the +options+ parameter to
+ *  ::new, ::compile and ::compile_file.
+ */
+static VALUE
+iseq_s_compile_option_set(VALUE self, VALUE opt)
+{
+    rb_compile_option_t option;
+    rb_secure(1);
+    make_compile_option(&option, opt);
+    COMPILE_OPTION_DEFAULT = option;
+    return opt;
+}
+
+/*
+ *  call-seq:
+ *     InstructionSequence.compile_option -> options
+ *
+ *  Returns a hash of default options used by the Ruby iseq compiler.
+ *
+ *  For details, see InstructionSequence.compile_option=.
+ */
+static VALUE
+iseq_s_compile_option_get(VALUE self)
+{
+    return make_compile_option_value(&COMPILE_OPTION_DEFAULT);
+}
+
+static rb_iseq_t *
+iseq_check(VALUE val)
+{
+    rb_iseq_t *iseq;
+    GetISeqPtr(val, iseq);
+    if (!iseq->location.label) {
+	rb_raise(rb_eTypeError, "uninitialized InstructionSequence");
+    }
+    return iseq;
+}
+
+/*
+ *  call-seq:
+ *     iseq.eval -> obj
+ *
+ *  Evaluates the instruction sequence and returns the result.
+ *
+ *      RubyVM::InstructionSequence.compile("1 + 2").eval #=> 3
+ */
+static VALUE
+iseq_eval(VALUE self)
+{
+    rb_secure(1);
+    return rb_iseq_eval(self);
+}
+
+/*
+ *  Returns a human-readable string representation of this instruction
+ *  sequence, including the #label and #path.
+ */
+static VALUE
+iseq_inspect(VALUE self)
+{
+    rb_iseq_t *iseq;
+    GetISeqPtr(self, iseq);
+    if (!iseq->location.label) {
+        return rb_sprintf("#<%s: uninitialized>", rb_obj_classname(self));
+    }
+
+    return rb_sprintf("<%s:%s@%s>",
+                      rb_obj_classname(self),
+		      RSTRING_PTR(iseq->location.label), RSTRING_PTR(iseq->location.path));
+}
+
+/*
+ *  Returns the path of this instruction sequence.
+ *
+ *  <code><compiled></code> if the iseq was evaluated from a string.
+ *
+ *  For example, using irb:
+ *
+ *	iseq = RubyVM::InstructionSequence.compile('num = 1 + 2')
+ *	#=> <RubyVM::InstructionSequence:<compiled>@<compiled>>
+ *	iseq.path
+ *	#=> "<compiled>"
+ *
+ *  Using ::compile_file:
+ *
+ *	# /tmp/method.rb
+ *	def hello
+ *	  puts "hello, world"
+ *	end
+ *
+ *	# in irb
+ *	> iseq = RubyVM::InstructionSequence.compile_file('/tmp/method.rb')
+ *	> iseq.path #=> /tmp/method.rb
+ */
+VALUE
+rb_iseq_path(VALUE self)
+{
+    rb_iseq_t *iseq;
+    GetISeqPtr(self, iseq);
+    return iseq->location.path;
+}
+
+/*
+ *  Returns the absolute path of this instruction sequence.
+ *
+ *  +nil+ if the iseq was evaluated from a string.
+ *
+ *  For example, using ::compile_file:
+ *
+ *	# /tmp/method.rb
+ *	def hello
+ *	  puts "hello, world"
+ *	end
+ *
+ *	# in irb
+ *	> iseq = RubyVM::InstructionSequence.compile_file('/tmp/method.rb')
+ *	> iseq.absolute_path #=> /tmp/method.rb
+ */
+VALUE
+rb_iseq_absolute_path(VALUE self)
+{
+    rb_iseq_t *iseq;
+    GetISeqPtr(self, iseq);
+    return iseq->location.absolute_path;
+}
+
+/*  Returns the label of this instruction sequence.
+ *
+ *  <code><main></code> if it's at the top level, <code><compiled></code> if it
+ *  was evaluated from a string.
+ *
+ *  For example, using irb:
+ *
+ *	iseq = RubyVM::InstructionSequence.compile('num = 1 + 2')
+ *	#=> <RubyVM::InstructionSequence:<compiled>@<compiled>>
+ *	iseq.label
+ *	#=> "<compiled>"
+ *
+ *  Using ::compile_file:
+ *
+ *	# /tmp/method.rb
+ *	def hello
+ *	  puts "hello, world"
+ *	end
+ *
+ *	# in irb
+ *	> iseq = RubyVM::InstructionSequence.compile_file('/tmp/method.rb')
+ *	> iseq.label #=> <main>
+ */
+VALUE
+rb_iseq_label(VALUE self)
+{
+    rb_iseq_t *iseq;
+    GetISeqPtr(self, iseq);
+    return iseq->location.label;
+}
+
+/*  Returns the base label of this instruction sequence.
+ *
+ *  For example, using irb:
+ *
+ *	iseq = RubyVM::InstructionSequence.compile('num = 1 + 2')
+ *	#=> <RubyVM::InstructionSequence:<compiled>@<compiled>>
+ *	iseq.base_label
+ *	#=> "<compiled>"
+ *
+ *  Using ::compile_file:
+ *
+ *	# /tmp/method.rb
+ *	def hello
+ *	  puts "hello, world"
+ *	end
+ *
+ *	# in irb
+ *	> iseq = RubyVM::InstructionSequence.compile_file('/tmp/method.rb')
+ *	> iseq.base_label #=> <main>
+ */
+VALUE
+rb_iseq_base_label(VALUE self)
+{
+    rb_iseq_t *iseq;
+    GetISeqPtr(self, iseq);
+    return iseq->location.base_label;
+}
+
+/*  Returns the number of the first source line where the instruction sequence
+ *  was loaded from.
+ *
+ *  For example, using irb:
+ *
+ *	iseq = RubyVM::InstructionSequence.compile('num = 1 + 2')
+ *	#=> <RubyVM::InstructionSequence:<compiled>@<compiled>>
+ *	iseq.first_lineno
+ *	#=> 1
+ */
+VALUE
+rb_iseq_first_lineno(VALUE self)
+{
+    rb_iseq_t *iseq;
+    GetISeqPtr(self, iseq);
+    return iseq->location.first_lineno;
+}
+
+VALUE
+rb_iseq_klass(VALUE self)
+{
+    rb_iseq_t *iseq;
+    GetISeqPtr(self, iseq);
+    return iseq->local_iseq->klass;
+}
+
+VALUE
+rb_iseq_method_name(VALUE self)
+{
+    rb_iseq_t *iseq, *local_iseq;
+    GetISeqPtr(self, iseq);
+    local_iseq = iseq->local_iseq;
+    if (local_iseq->type == ISEQ_TYPE_METHOD) {
+	return local_iseq->location.base_label;
+    }
+    else {
+	return Qnil;
+    }
+}
+
+static
+VALUE iseq_data_to_ary(rb_iseq_t *iseq);
+
+/*
+ *  call-seq:
+ *     iseq.to_a -> ary
+ *
+ *  Returns an Array with 14 elements representing the instruction sequence
+ *  with the following data:
+ *
+ *  [magic]
+ *    A string identifying the data format. <b>Always
+ *    +YARVInstructionSequence/SimpleDataFormat+.</b>
+ *
+ *  [major_version]
+ *    The major version of the instruction sequence.
+ *
+ *  [minor_version]
+ *    The minor version of the instruction sequence.
+ *
+ *  [format_type]
+ *    A number identifying the data format. <b>Always 1</b>.
+ *
+ *  [misc]
+ *    A hash containing:
+ *
+ *    [+:arg_size+]
+ *	the total number of arguments taken by the method or the block (0 if
+ *	_iseq_ doesn't represent a method or block)
+ *    [+:local_size+]
+ *	the number of local variables + 1
+ *    [+:stack_max+]
+ *	used in calculating the stack depth at which a SystemStackError is
+ *	thrown.
+ *
+ *  [#label]
+ *    The name of the context (block, method, class, module, etc.) that this
+ *    instruction sequence belongs to.
+ *
+ *    <code><main></code> if it's at the top level, <code><compiled></code> if
+ *    it was evaluated from a string.
+ *
+ *  [#path]
+ *    The relative path to the Ruby file where the instruction sequence was
+ *    loaded from.
+ *
+ *    <code><compiled></code> if the iseq was evaluated from a string.
+ *
+ *  [#absolute_path]
+ *    The absolute path to the Ruby file where the instruction sequence was
+ *    loaded from.
+ *
+ *    +nil+ if the iseq was evaluated from a string.
+ *
+ *  [#first_lineno]
+ *    The number of the first source line where the instruction sequence was
+ *    loaded from.
+ *
+ *  [type]
+ *    The type of the instruction sequence.
+ *
+ *    Valid values are +:top+, +:method+, +:block+, +:class+, +:rescue+,
+ *    +:ensure+, +:eval+, +:main+, and +:defined_guard+.
+ *
+ *  [locals]
+ *    An array containing the names of all arguments and local variables as
+ *    symbols.
+ *
+ *  [params]
+ *    An Hash object containing parameter information.
+ *
+ *    More info about these values can be found in +vm_core.h+.
+ *
+ *  [catch_table]
+ *    A list of exceptions and control flow operators (rescue, next, redo,
+ *    break, etc.).
+ *
+ *  [bytecode]
+ *    An array of arrays containing the instruction names and operands that
+ *    make up the body of the instruction sequence.
+ *
+ *  Note that this format is MRI specific and version dependent.
+ *
+ */
+static VALUE
+iseq_to_a(VALUE self)
+{
+    rb_iseq_t *iseq = iseq_check(self);
+    rb_secure(1);
+    return iseq_data_to_ary(iseq);
+}
+
+/* TODO: search algorithm is brute force.
+         this should be binary search or so. */
+
+static struct iseq_line_info_entry *
+get_line_info(const rb_iseq_t *iseq, size_t pos)
+{
+    size_t i = 0, size = iseq->line_info_size;
+    struct iseq_line_info_entry *table = iseq->line_info_table;
+    const int debug = 0;
+
+    if (debug) {
+	printf("size: %"PRIdSIZE"\n", size);
+	printf("table[%"PRIdSIZE"]: position: %d, line: %d, pos: %"PRIdSIZE"\n",
+	       i, table[i].position, table[i].line_no, pos);
+    }
+
+    if (size == 0) {
+	return 0;
+    }
+    else if (size == 1) {
+	return &table[0];
+    }
+    else {
+	for (i=1; i<size; i++) {
+	    if (debug) printf("table[%"PRIdSIZE"]: position: %d, line: %d, pos: %"PRIdSIZE"\n",
+			      i, table[i].position, table[i].line_no, pos);
+
+	    if (table[i].position == pos) {
+		return &table[i];
+	    }
+	    if (table[i].position > pos) {
+		return &table[i-1];
+	    }
+	}
+    }
+    return &table[i-1];
+}
+
+static unsigned int
+find_line_no(const rb_iseq_t *iseq, size_t pos)
+{
+    struct iseq_line_info_entry *entry = get_line_info(iseq, pos);
+    if (entry) {
+	return entry->line_no;
+    }
+    else {
+	return 0;
+    }
+}
+
+unsigned int
+rb_iseq_line_no(const rb_iseq_t *iseq, size_t pos)
+{
+    if (pos == 0) {
+	return find_line_no(iseq, pos);
+    }
+    else {
+	return find_line_no(iseq, pos - 1);
+    }
+}
+
+static VALUE
+id_to_name(ID id, VALUE default_value)
+{
+    VALUE str = rb_id2str(id);
+    if (!str) {
+	str = default_value;
+    }
+    else if (!rb_str_symname_p(str)) {
+	str = rb_str_inspect(str);
+    }
+    return str;
+}
+
+VALUE
+rb_insn_operand_intern(const rb_iseq_t *iseq,
+		       VALUE insn, int op_no, VALUE op,
+		       int len, size_t pos, const VALUE *pnop, VALUE child)
+{
+    const char *types = insn_op_types(insn);
+    char type = types[op_no];
+    VALUE ret;
+
+    switch (type) {
+      case TS_OFFSET:		/* LONG */
+	ret = rb_sprintf("%"PRIdVALUE, (VALUE)(pos + len + op));
+	break;
+
+      case TS_NUM:		/* ULONG */
+	ret = rb_sprintf("%"PRIuVALUE, op);
+	break;
+
+      case TS_LINDEX:{
+	if (insn == BIN(getlocal) || insn == BIN(setlocal)) {
+	    if (pnop) {
+		const rb_iseq_t *diseq = iseq;
+		VALUE level = *pnop, i;
+
+		for (i = 0; i < level; i++) {
+		    diseq = diseq->parent_iseq;
+		}
+		ret = id_to_name(diseq->local_table[diseq->local_size - op], INT2FIX('*'));
+	    }
+	    else {
+		ret = rb_sprintf("%"PRIuVALUE, op);
+	    }
+	}
+	else {
+	    ret = rb_inspect(INT2FIX(op));
+	}
+	break;
+      }
+      case TS_ID:		/* ID (symbol) */
+	op = ID2SYM(op);
+
+      case TS_VALUE:		/* VALUE */
+	op = obj_resurrect(op);
+	ret = rb_inspect(op);
+	if (CLASS_OF(op) == rb_cISeq) {
+	    if (child) {
+		rb_ary_push(child, op);
+	    }
+	}
+	break;
+
+      case TS_ISEQ:		/* iseq */
+	{
+	    rb_iseq_t *iseq = (rb_iseq_t *)op;
+	    if (iseq) {
+		ret = iseq->location.label;
+		if (child) {
+		    rb_ary_push(child, iseq->self);
+		}
+	    }
+	    else {
+		ret = rb_str_new2("nil");
+	    }
+	    break;
+	}
+      case TS_GENTRY:
+	{
+	    struct rb_global_entry *entry = (struct rb_global_entry *)op;
+	    ret = rb_str_dup(rb_id2str(entry->id));
+	}
+	break;
+
+      case TS_IC:
+	ret = rb_sprintf("<is:%"PRIdPTRDIFF">", (union iseq_inline_storage_entry *)op - iseq->is_entries);
+	break;
+
+      case TS_CALLINFO:
+	{
+	    rb_call_info_t *ci = (rb_call_info_t *)op;
+	    VALUE ary = rb_ary_new();
+
+	    if (ci->mid) {
+		rb_ary_push(ary, rb_sprintf("mid:%"PRIsVALUE, rb_id2str(ci->mid)));
+	    }
+
+	    rb_ary_push(ary, rb_sprintf("argc:%d", ci->orig_argc));
+
+	    if (ci->kw_arg) {
+		rb_ary_push(ary, rb_sprintf("kw:%d", ci->kw_arg->keyword_len));
+	    }
+	    if (ci->blockiseq) {
+		if (child) {
+		    rb_ary_push(child, ci->blockiseq->self);
+		}
+		rb_ary_push(ary, rb_sprintf("block:%"PRIsVALUE, ci->blockiseq->location.label));
+	    }
+
+	    if (ci->flag) {
+		VALUE flags = rb_ary_new();
+		if (ci->flag & VM_CALL_ARGS_SPLAT) rb_ary_push(flags, rb_str_new2("ARGS_SPLAT"));
+		if (ci->flag & VM_CALL_ARGS_BLOCKARG) rb_ary_push(flags, rb_str_new2("ARGS_BLOCKARG"));
+		if (ci->flag & VM_CALL_FCALL) rb_ary_push(flags, rb_str_new2("FCALL"));
+		if (ci->flag & VM_CALL_VCALL) rb_ary_push(flags, rb_str_new2("VCALL"));
+		if (ci->flag & VM_CALL_TAILCALL) rb_ary_push(flags, rb_str_new2("TAILCALL"));
+		if (ci->flag & VM_CALL_SUPER) rb_ary_push(flags, rb_str_new2("SUPER"));
+		if (ci->flag & VM_CALL_OPT_SEND) rb_ary_push(flags, rb_str_new2("SNED")); /* maybe not reachable */
+		if (ci->flag & VM_CALL_ARGS_SIMPLE) rb_ary_push(flags, rb_str_new2("ARGS_SIMPLE")); /* maybe not reachable */
+		rb_ary_push(ary, rb_ary_join(flags, rb_str_new2("|")));
+	    }
+	    ret = rb_sprintf("<callinfo!%"PRIsVALUE">", rb_ary_join(ary, rb_str_new2(", ")));
+	}
+	break;
+
+      case TS_CDHASH:
+	ret = rb_str_new2("<cdhash>");
+	break;
+
+      case TS_FUNCPTR:
+	{
+#ifdef HAVE_DLADDR
+	    Dl_info info;
+	    if (dladdr((void *)op, &info) && info.dli_sname) {
+		ret = rb_str_new_cstr(info.dli_sname);
+		break;
+	    }
+#endif
+	    ret = rb_str_new2("<funcptr>");
+	}
+	break;
+
+      default:
+	rb_bug("insn_operand_intern: unknown operand type: %c", type);
+    }
+    return ret;
+}
+
+/**
+ * Disassemble a instruction
+ * Iseq -> Iseq inspect object
+ */
+int
+rb_iseq_disasm_insn(VALUE ret, const VALUE *iseq, size_t pos,
+		    const rb_iseq_t *iseqdat, VALUE child)
+{
+    VALUE insn = iseq[pos];
+    int len = insn_len(insn);
+    int j;
+    const char *types = insn_op_types(insn);
+    VALUE str = rb_str_new(0, 0);
+    const char *insn_name_buff;
+
+    insn_name_buff = insn_name(insn);
+    if (1) {
+	rb_str_catf(str, "%04"PRIdSIZE" %-16s ", pos, insn_name_buff);
+    }
+    else {
+	rb_str_catf(str, "%04"PRIdSIZE" %-16.*s ", pos,
+		    (int)strcspn(insn_name_buff, "_"), insn_name_buff);
+    }
+
+    for (j = 0; types[j]; j++) {
+	const char *types = insn_op_types(insn);
+	VALUE opstr = rb_insn_operand_intern(iseqdat, insn, j, iseq[pos + j + 1],
+					     len, pos, &iseq[pos + j + 2],
+					     child);
+	rb_str_concat(str, opstr);
+
+	if (types[j + 1]) {
+	    rb_str_cat2(str, ", ");
+	}
+    }
+
+    {
+	unsigned int line_no = find_line_no(iseqdat, pos);
+	unsigned int prev = pos == 0 ? 0 : find_line_no(iseqdat, pos - 1);
+	if (line_no && line_no != prev) {
+	    long slen = RSTRING_LEN(str);
+	    slen = (slen > 70) ? 0 : (70 - slen);
+	    str = rb_str_catf(str, "%*s(%4d)", (int)slen, "", line_no);
+	}
+    }
+
+    if (ret) {
+	rb_str_cat2(str, "\n");
+	rb_str_concat(ret, str);
+    }
+    else {
+	printf("%s\n", RSTRING_PTR(str));
+    }
+    return len;
+}
+
+static const char *
+catch_type(int type)
+{
+    switch (type) {
+      case CATCH_TYPE_RESCUE:
+	return "rescue";
+      case CATCH_TYPE_ENSURE:
+	return "ensure";
+      case CATCH_TYPE_RETRY:
+	return "retry";
+      case CATCH_TYPE_BREAK:
+	return "break";
+      case CATCH_TYPE_REDO:
+	return "redo";
+      case CATCH_TYPE_NEXT:
+	return "next";
+      default:
+	rb_bug("unknown catch type (%d)", type);
+	return 0;
+    }
+}
+
+/*
+ *  call-seq:
+ *     iseq.disasm -> str
+ *     iseq.disassemble -> str
+ *
+ *  Returns the instruction sequence as a +String+ in human readable form.
+ *
+ *    puts RubyVM::InstructionSequence.compile('1 + 2').disasm
+ *
+ *  Produces:
+ *
+ *    == disasm: <RubyVM::InstructionSequence:<compiled>@<compiled>>==========
+ *    0000 trace            1                                               (   1)
+ *    0002 putobject        1
+ *    0004 putobject        2
+ *    0006 opt_plus         <ic:1>
+ *    0008 leave
+ */
+VALUE
+rb_iseq_disasm(VALUE self)
+{
+    rb_iseq_t *iseqdat = iseq_check(self); /* TODO: rename to iseq */
+    VALUE *iseq;
+    VALUE str = rb_str_new(0, 0);
+    VALUE child = rb_ary_new();
+    unsigned int size;
+    int i;
+    long l;
+    ID *tbl;
+    size_t n;
+    enum {header_minlen = 72};
+
+    rb_secure(1);
+
+    size = iseqdat->iseq_size;
+
+    rb_str_cat2(str, "== disasm: ");
+
+    rb_str_concat(str, iseq_inspect(iseqdat->self));
+    if ((l = RSTRING_LEN(str)) < header_minlen) {
+	rb_str_resize(str, header_minlen);
+	memset(RSTRING_PTR(str) + l, '=', header_minlen - l);
+    }
+    rb_str_cat2(str, "\n");
+
+    /* show catch table information */
+    if (iseqdat->catch_table) {
+	rb_str_cat2(str, "== catch table\n");
+    }
+    if (iseqdat->catch_table) for (i = 0; i < iseqdat->catch_table->size; i++) {
+	struct iseq_catch_table_entry *entry = &iseqdat->catch_table->entries[i];
+	rb_str_catf(str,
+		    "| catch type: %-6s st: %04d ed: %04d sp: %04d cont: %04d\n",
+		    catch_type((int)entry->type), (int)entry->start,
+		    (int)entry->end, (int)entry->sp, (int)entry->cont);
+	if (entry->iseq) {
+	    rb_str_concat(str, rb_iseq_disasm(entry->iseq));
+	}
+    }
+    if (iseqdat->catch_table) {
+	rb_str_cat2(str, "|-------------------------------------"
+		    "-----------------------------------\n");
+    }
+
+    /* show local table information */
+    tbl = iseqdat->local_table;
+
+    if (tbl) {
+	rb_str_catf(str,
+		    "local table (size: %d, argc: %d "
+		    "[opts: %d, rest: %d, post: %d, block: %d, kw: %d@%d, kwrest: %d])\n",
+		    iseqdat->local_size,
+		    iseqdat->param.lead_num,
+		    iseqdat->param.opt_num,
+		    iseqdat->param.flags.has_rest ? iseqdat->param.rest_start : -1,
+		    iseqdat->param.post_num,
+		    iseqdat->param.flags.has_block ? iseqdat->param.block_start : -1,
+		    iseqdat->param.flags.has_kw ? iseqdat->param.keyword->num : -1,
+		    iseqdat->param.flags.has_kw ? iseqdat->param.keyword->required_num : -1,
+		    iseqdat->param.flags.has_kwrest ? iseqdat->param.keyword->rest_start : -1);
+
+	for (i = 0; i < iseqdat->local_table_size; i++) {
+	    long width;
+	    VALUE name = id_to_name(tbl[i], 0);
+	    char argi[0x100] = "";
+	    char opti[0x100] = "";
+
+	    if (iseqdat->param.flags.has_opt) {
+		int argc = iseqdat->param.lead_num;
+		int opts = iseqdat->param.opt_num;
+		if (i >= argc && i < argc + opts) {
+		    snprintf(opti, sizeof(opti), "Opt=%"PRIdVALUE,
+			     iseqdat->param.opt_table[i - argc]);
+		}
+	    }
+
+	    snprintf(argi, sizeof(argi), "%s%s%s%s%s",	/* arg, opts, rest, post  block */
+		     iseqdat->param.lead_num > i ? "Arg" : "",
+		     opti,
+		     (iseqdat->param.flags.has_rest && iseqdat->param.rest_start == i) ? "Rest" : "",
+		     (iseqdat->param.flags.has_post && iseqdat->param.post_start <= i && i < iseqdat->param.post_start + iseqdat->param.post_num) ? "Post" : "",
+		     (iseqdat->param.flags.has_block && iseqdat->param.block_start == i) ? "Block" : "");
+
+	    rb_str_catf(str, "[%2d] ", iseqdat->local_size - i);
+	    width = RSTRING_LEN(str) + 11;
+	    if (name)
+		rb_str_append(str, name);
+	    else
+		rb_str_cat2(str, "?");
+	    if (*argi) rb_str_catf(str, "<%s>", argi);
+	    if ((width -= RSTRING_LEN(str)) > 0) rb_str_catf(str, "%*s", (int)width, "");
+	}
+	rb_str_cat2(str, "\n");
+    }
+
+    /* show each line */
+    iseq = rb_iseq_original_iseq(iseqdat);
+    for (n = 0; n < size;) {
+	n += rb_iseq_disasm_insn(str, iseq, n, iseqdat, child);
+    }
+
+    for (i = 0; i < RARRAY_LEN(child); i++) {
+	VALUE isv = rb_ary_entry(child, i);
+	rb_str_concat(str, rb_iseq_disasm(isv));
+    }
+
+    return str;
+}
+
+/*
+ *  Returns the instruction sequence containing the given proc or method.
+ *
+ *  For example, using irb:
+ *
+ *	# a proc
+ *	> p = proc { num = 1 + 2 }
+ *	> RubyVM::InstructionSequence.of(p)
+ *	> #=> <RubyVM::InstructionSequence:block in irb_binding@(irb)>
+ *
+ *	# for a method
+ *	> def foo(bar); puts bar; end
+ *	> RubyVM::InstructionSequence.of(method(:foo))
+ *	> #=> <RubyVM::InstructionSequence:foo@(irb)>
+ *
+ *  Using ::compile_file:
+ *
+ *	# /tmp/iseq_of.rb
+ *	def hello
+ *	  puts "hello, world"
+ *	end
+ *
+ *	$a_global_proc = proc { str = 'a' + 'b' }
+ *
+ *	# in irb
+ *	> require '/tmp/iseq_of.rb'
+ *
+ *	# first the method hello
+ *	> RubyVM::InstructionSequence.of(method(:hello))
+ *	> #=> #<RubyVM::InstructionSequence:0x007fb73d7cb1d0>
+ *
+ *	# then the global proc
+ *	> RubyVM::InstructionSequence.of($a_global_proc)
+ *	> #=> #<RubyVM::InstructionSequence:0x007fb73d7caf78>
+ */
+static VALUE
+iseq_s_of(VALUE klass, VALUE body)
+{
+    VALUE ret = Qnil;
+    rb_iseq_t *iseq;
+
+    rb_secure(1);
+
+    if (rb_obj_is_proc(body)) {
+	rb_proc_t *proc;
+	GetProcPtr(body, proc);
+	iseq = proc->block.iseq;
+	if (RUBY_VM_NORMAL_ISEQ_P(iseq)) {
+	    ret = iseq->self;
+	}
+    }
+    else if ((iseq = rb_method_get_iseq(body)) != 0) {
+	ret = iseq->self;
+    }
+    return ret;
+}
+
+/*
+ *  call-seq:
+ *     InstructionSequence.disasm(body) -> str
+ *     InstructionSequence.disassemble(body) -> str
+ *
+ *  Takes +body+, a Method or Proc object, and returns a String with the
+ *  human readable instructions for +body+.
+ *
+ *  For a Method object:
+ *
+ *    # /tmp/method.rb
+ *    def hello
+ *      puts "hello, world"
+ *    end
+ *
+ *    puts RubyVM::InstructionSequence.disasm(method(:hello))
+ *
+ *  Produces:
+ *
+ *    == disasm: <RubyVM::InstructionSequence:hello@/tmp/method.rb>============
+ *    0000 trace            8                                               (   1)
+ *    0002 trace            1                                               (   2)
+ *    0004 putself
+ *    0005 putstring        "hello, world"
+ *    0007 send             :puts, 1, nil, 8, <ic:0>
+ *    0013 trace            16                                              (   3)
+ *    0015 leave                                                            (   2)
+ *
+ *  For a Proc:
+ *
+ *    # /tmp/proc.rb
+ *    p = proc { num = 1 + 2 }
+ *    puts RubyVM::InstructionSequence.disasm(p)
+ *
+ *  Produces:
+ *
+ *    == disasm: <RubyVM::InstructionSequence:block in <main>@/tmp/proc.rb>===
+ *    == catch table
+ *    | catch type: redo   st: 0000 ed: 0012 sp: 0000 cont: 0000
+ *    | catch type: next   st: 0000 ed: 0012 sp: 0000 cont: 0012
+ *    |------------------------------------------------------------------------
+ *    local table (size: 2, argc: 0 [opts: 0, rest: -1, post: 0, block: -1] s1)
+ *    [ 2] num
+ *    0000 trace            1                                               (   1)
+ *    0002 putobject        1
+ *    0004 putobject        2
+ *    0006 opt_plus         <ic:1>
+ *    0008 dup
+ *    0009 setlocal         num, 0
+ *    0012 leave
+ *
+ */
+
+static VALUE
+iseq_s_disasm(VALUE klass, VALUE body)
+{
+    VALUE iseqval = iseq_s_of(klass, body);
+    return NIL_P(iseqval) ? Qnil : rb_iseq_disasm(iseqval);
+}
+
+const char *
+ruby_node_name(int node)
+{
+    switch (node) {
+#include "node_name.inc"
+      default:
+	rb_bug("unknown node (%d)", node);
+	return 0;
+    }
+}
+
+#define DECL_SYMBOL(name) \
+  static VALUE sym_##name
+
+#define INIT_SYMBOL(name) \
+  sym_##name = ID2SYM(rb_intern(#name))
+
+static VALUE
+register_label(struct st_table *table, unsigned long idx)
+{
+    VALUE sym = rb_str_intern(rb_sprintf("label_%lu", idx));
+    st_insert(table, idx, sym);
+    return sym;
+}
+
+static VALUE
+exception_type2symbol(VALUE type)
+{
+    ID id;
+    switch (type) {
+      case CATCH_TYPE_RESCUE: CONST_ID(id, "rescue"); break;
+      case CATCH_TYPE_ENSURE: CONST_ID(id, "ensure"); break;
+      case CATCH_TYPE_RETRY:  CONST_ID(id, "retry");  break;
+      case CATCH_TYPE_BREAK:  CONST_ID(id, "break");  break;
+      case CATCH_TYPE_REDO:   CONST_ID(id, "redo");   break;
+      case CATCH_TYPE_NEXT:   CONST_ID(id, "next");   break;
+      default:
+	rb_bug("...");
+    }
+    return ID2SYM(id);
+}
+
+static int
+cdhash_each(VALUE key, VALUE value, VALUE ary)
+{
+    rb_ary_push(ary, obj_resurrect(key));
+    rb_ary_push(ary, value);
+    return ST_CONTINUE;
+}
+
+static VALUE
+iseq_data_to_ary(rb_iseq_t *iseq)
+{
+    long i;
+    size_t ti;
+    unsigned int pos;
+    unsigned int line = 0;
+    VALUE *seq, *iseq_original;
+
+    VALUE val = rb_ary_new();
+    VALUE type; /* Symbol */
+    VALUE locals = rb_ary_new();
+    VALUE params = rb_hash_new();
+    VALUE body = rb_ary_new(); /* [[:insn1, ...], ...] */
+    VALUE nbody;
+    VALUE exception = rb_ary_new(); /* [[....]] */
+    VALUE misc = rb_hash_new();
+
+    static VALUE insn_syms[VM_INSTRUCTION_SIZE];
+    struct st_table *labels_table = st_init_numtable();
+
+    DECL_SYMBOL(top);
+    DECL_SYMBOL(method);
+    DECL_SYMBOL(block);
+    DECL_SYMBOL(class);
+    DECL_SYMBOL(rescue);
+    DECL_SYMBOL(ensure);
+    DECL_SYMBOL(eval);
+    DECL_SYMBOL(main);
+    DECL_SYMBOL(defined_guard);
+
+    if (sym_top == 0) {
+	int i;
+	for (i=0; i<VM_INSTRUCTION_SIZE; i++) {
+	    insn_syms[i] = ID2SYM(rb_intern(insn_name(i)));
+	}
+	INIT_SYMBOL(top);
+	INIT_SYMBOL(method);
+	INIT_SYMBOL(block);
+	INIT_SYMBOL(class);
+	INIT_SYMBOL(rescue);
+	INIT_SYMBOL(ensure);
+	INIT_SYMBOL(eval);
+	INIT_SYMBOL(main);
+	INIT_SYMBOL(defined_guard);
+    }
+
+    /* type */
+    switch (iseq->type) {
+      case ISEQ_TYPE_TOP:    type = sym_top;    break;
+      case ISEQ_TYPE_METHOD: type = sym_method; break;
+      case ISEQ_TYPE_BLOCK:  type = sym_block;  break;
+      case ISEQ_TYPE_CLASS:  type = sym_class;  break;
+      case ISEQ_TYPE_RESCUE: type = sym_rescue; break;
+      case ISEQ_TYPE_ENSURE: type = sym_ensure; break;
+      case ISEQ_TYPE_EVAL:   type = sym_eval;   break;
+      case ISEQ_TYPE_MAIN:   type = sym_main;   break;
+      case ISEQ_TYPE_DEFINED_GUARD: type = sym_defined_guard; break;
+      default: rb_bug("unsupported iseq type");
+    };
+
+    /* locals */
+    for (i=0; i<iseq->local_table_size; i++) {
+	ID lid = iseq->local_table[i];
+	if (lid) {
+	    if (rb_id2str(lid)) {
+		rb_ary_push(locals, ID2SYM(lid));
+	    }
+	    else { /* hidden variable from id_internal() */
+		rb_ary_push(locals, ULONG2NUM(iseq->local_table_size-i+1));
+	    }
+	}
+	else {
+	    rb_ary_push(locals, ID2SYM(rb_intern("#arg_rest")));
+	}
+    }
+
+    /* params */
+    {
+	int j;
+
+	if (iseq->param.flags.has_opt) {
+          int len = iseq->param.opt_num + 1;
+          VALUE arg_opt_labels = rb_ary_new2(len);
+
+          for (j = 0; j < len; j++) {
+              VALUE l = register_label(labels_table, iseq->param.opt_table[j]);
+              rb_ary_push(arg_opt_labels, l);
+          }
+          rb_hash_aset(params, ID2SYM(rb_intern("opt")), arg_opt_labels);
+        }
+
+	/* commit */
+	if (iseq->param.flags.has_lead) rb_hash_aset(params, ID2SYM(rb_intern("lead_num")), INT2FIX(iseq->param.lead_num));
+	if (iseq->param.flags.has_post) rb_hash_aset(params, ID2SYM(rb_intern("post_num")), INT2FIX(iseq->param.post_num));
+	if (iseq->param.flags.has_post) rb_hash_aset(params, ID2SYM(rb_intern("post_start")), INT2FIX(iseq->param.post_start));
+	if (iseq->param.flags.has_rest) rb_hash_aset(params, ID2SYM(rb_intern("rest_start")), INT2FIX(iseq->param.rest_start));
+	if (iseq->param.flags.has_block) rb_hash_aset(params, ID2SYM(rb_intern("block_start")), INT2FIX(iseq->param.block_start));
+	if (iseq->param.flags.has_kw) {
+	    VALUE keywords = rb_ary_new();
+	    int i, j;
+	    for (i=0; i<iseq->param.keyword->required_num; i++) {
+		rb_ary_push(keywords, ID2SYM(iseq->param.keyword->table[i]));
+	    }
+	    for (j=0; i<iseq->param.keyword->num; i++, j++) {
+		VALUE key = rb_ary_new_from_args(1, ID2SYM(iseq->param.keyword->table[i]));
+		if (iseq->param.keyword->default_values[j] != Qundef) {
+		    rb_ary_push(key, iseq->param.keyword->default_values[j]);
+		}
+		rb_ary_push(keywords, key);
+	    }
+
+	    rb_hash_aset(params, ID2SYM(rb_intern("kwbits")),
+	                 INT2FIX(iseq->param.keyword->bits_start));
+	    rb_hash_aset(params, ID2SYM(rb_intern("keyword")), keywords);
+	}
+	if (iseq->param.flags.has_kwrest) rb_hash_aset(params, ID2SYM(rb_intern("kwrest")), INT2FIX(iseq->param.keyword->rest_start));
+	if (iseq->param.flags.ambiguous_param0) rb_hash_aset(params, ID2SYM(rb_intern("ambiguous_param0")), Qtrue);
+    }
+
+    /* body */
+    iseq_original = rb_iseq_original_iseq(iseq);
+
+    for (seq = iseq_original; seq < iseq_original + iseq->iseq_size; ) {
+	VALUE insn = *seq++;
+	int j, len = insn_len(insn);
+	VALUE *nseq = seq + len - 1;
+	VALUE ary = rb_ary_new2(len);
+
+	rb_ary_push(ary, insn_syms[insn]);
+	for (j=0; j<len-1; j++, seq++) {
+	    switch (insn_op_type(insn, j)) {
+	      case TS_OFFSET: {
+		unsigned long idx = nseq - iseq_original + *seq;
+		rb_ary_push(ary, register_label(labels_table, idx));
+		break;
+	      }
+	      case TS_LINDEX:
+	      case TS_NUM:
+		rb_ary_push(ary, INT2FIX(*seq));
+		break;
+	      case TS_VALUE:
+		rb_ary_push(ary, obj_resurrect(*seq));
+		break;
+	      case TS_ISEQ:
+		{
+		    rb_iseq_t *iseq = (rb_iseq_t *)*seq;
+		    if (iseq) {
+			VALUE val = iseq_data_to_ary(iseq);
+			rb_ary_push(ary, val);
+		    }
+		    else {
+			rb_ary_push(ary, Qnil);
+		    }
+		}
+		break;
+	      case TS_GENTRY:
+		{
+		    struct rb_global_entry *entry = (struct rb_global_entry *)*seq;
+		    rb_ary_push(ary, ID2SYM(entry->id));
+		}
+		break;
+	      case TS_IC:
+		{
+		    union iseq_inline_storage_entry *is = (union iseq_inline_storage_entry *)*seq;
+		    rb_ary_push(ary, INT2FIX(is - iseq->is_entries));
+		}
+		break;
+	      case TS_CALLINFO:
+		{
+		    rb_call_info_t *ci = (rb_call_info_t *)*seq;
+		    VALUE e = rb_hash_new();
+		    int orig_argc = ci->orig_argc;
+
+		    rb_hash_aset(e, ID2SYM(rb_intern("mid")), ci->mid ? ID2SYM(ci->mid) : Qnil);
+		    rb_hash_aset(e, ID2SYM(rb_intern("flag")), UINT2NUM(ci->flag));
+		    rb_hash_aset(e, ID2SYM(rb_intern("blockptr")), ci->blockiseq ? iseq_data_to_ary(ci->blockiseq) : Qnil);
+
+		    if (ci->kw_arg) {
+			int i;
+			VALUE kw = rb_ary_new2((long)ci->kw_arg->keyword_len);
+
+			orig_argc -= ci->kw_arg->keyword_len;
+			for (i = 0; i < ci->kw_arg->keyword_len; i++) {
+			    rb_ary_push(kw, ID2SYM(ci->kw_arg->keywords[i]));
+			}
+			rb_hash_aset(e, ID2SYM(rb_intern("kw_arg")), kw);
+		    }
+
+		    rb_hash_aset(e, ID2SYM(rb_intern("orig_argc")),
+				INT2FIX(orig_argc));
+		    rb_ary_push(ary, e);
+	        }
+		break;
+	      case TS_ID:
+		rb_ary_push(ary, ID2SYM(*seq));
+		break;
+	      case TS_CDHASH:
+		{
+		    VALUE hash = *seq;
+		    VALUE val = rb_ary_new();
+		    int i;
+
+		    rb_hash_foreach(hash, cdhash_each, val);
+
+		    for (i=0; i<RARRAY_LEN(val); i+=2) {
+			VALUE pos = FIX2INT(rb_ary_entry(val, i+1));
+			unsigned long idx = nseq - iseq_original + pos;
+
+			rb_ary_store(val, i+1,
+				     register_label(labels_table, idx));
+		    }
+		    rb_ary_push(ary, val);
+		}
+		break;
+	      case TS_FUNCPTR:
+		{
+#if SIZEOF_VALUE <= SIZEOF_LONG
+		    VALUE val = LONG2NUM((SIGNED_VALUE)*seq);
+#else
+		    VALUE val = LL2NUM((SIGNED_VALUE)*seq);
+#endif
+		    rb_ary_push(ary, val);
+		}
+		break;
+	      default:
+		rb_bug("unknown operand: %c", insn_op_type(insn, j));
+	    }
+	}
+	rb_ary_push(body, ary);
+    }
+
+    nbody = body;
+
+    /* exception */
+    if (iseq->catch_table) for (i=0; i<iseq->catch_table->size; i++) {
+	VALUE ary = rb_ary_new();
+	struct iseq_catch_table_entry *entry = &iseq->catch_table->entries[i];
+	rb_ary_push(ary, exception_type2symbol(entry->type));
+	if (entry->iseq) {
+	    rb_iseq_t *eiseq;
+	    GetISeqPtr(entry->iseq, eiseq);
+	    rb_ary_push(ary, iseq_data_to_ary(eiseq));
+	}
+	else {
+	    rb_ary_push(ary, Qnil);
+	}
+	rb_ary_push(ary, register_label(labels_table, entry->start));
+	rb_ary_push(ary, register_label(labels_table, entry->end));
+	rb_ary_push(ary, register_label(labels_table, entry->cont));
+	rb_ary_push(ary, UINT2NUM(entry->sp));
+	rb_ary_push(exception, ary);
+    }
+
+    /* make body with labels and insert line number */
+    body = rb_ary_new();
+    ti = 0;
+
+    for (i=0, pos=0; i<RARRAY_LEN(nbody); i++) {
+	VALUE ary = RARRAY_AREF(nbody, i);
+	st_data_t label;
+
+	if (st_lookup(labels_table, pos, &label)) {
+	    rb_ary_push(body, (VALUE)label);
+	}
+
+	if (ti < iseq->line_info_size && iseq->line_info_table[ti].position == pos) {
+	    line = iseq->line_info_table[ti].line_no;
+	    rb_ary_push(body, INT2FIX(line));
+	    ti++;
+	}
+
+	rb_ary_push(body, ary);
+	pos += RARRAY_LENINT(ary); /* reject too huge data */
+    }
+    RB_GC_GUARD(nbody);
+
+    st_free_table(labels_table);
+
+    rb_hash_aset(misc, ID2SYM(rb_intern("arg_size")), INT2FIX(iseq->param.size));
+    rb_hash_aset(misc, ID2SYM(rb_intern("local_size")), INT2FIX(iseq->local_size));
+    rb_hash_aset(misc, ID2SYM(rb_intern("stack_max")), INT2FIX(iseq->stack_max));
+
+    /* TODO: compatibility issue */
+    /*
+     * [:magic, :major_version, :minor_version, :format_type, :misc,
+     *  :name, :path, :absolute_path, :start_lineno, :type, :locals, :args,
+     *  :catch_table, :bytecode]
+     */
+    rb_ary_push(val, rb_str_new2("YARVInstructionSequence/SimpleDataFormat"));
+    rb_ary_push(val, INT2FIX(ISEQ_MAJOR_VERSION)); /* major */
+    rb_ary_push(val, INT2FIX(ISEQ_MINOR_VERSION)); /* minor */
+    rb_ary_push(val, INT2FIX(1));
+    rb_ary_push(val, misc);
+    rb_ary_push(val, iseq->location.label);
+    rb_ary_push(val, iseq->location.path);
+    rb_ary_push(val, iseq->location.absolute_path);
+    rb_ary_push(val, iseq->location.first_lineno);
+    rb_ary_push(val, type);
+    rb_ary_push(val, locals);
+    rb_ary_push(val, params);
+    rb_ary_push(val, exception);
+    rb_ary_push(val, body);
+    return val;
+}
+
+VALUE
+rb_iseq_clone(VALUE iseqval, VALUE newcbase)
+{
+    VALUE newiseq = iseq_alloc(rb_cISeq);
+    rb_iseq_t *iseq0, *iseq1;
+
+    GetISeqPtr(iseqval, iseq0);
+    GetISeqPtr(newiseq, iseq1);
+
+    MEMCPY(iseq1, iseq0, rb_iseq_t, 1); /* TODO: write barrier? */
+
+    iseq1->self = newiseq;
+    if (!iseq1->orig) {
+	RB_OBJ_WRITE(iseq1->self, &iseq1->orig, iseqval);
+    }
+    if (iseq0->local_iseq == iseq0) {
+	iseq1->local_iseq = iseq1;
+    }
+    if (newcbase) {
+	ISEQ_SET_CREF(iseq1, NEW_CREF(newcbase));
+	RB_OBJ_WRITE(iseq1->cref_stack, &iseq1->cref_stack->nd_refinements, iseq0->cref_stack->nd_refinements);
+	iseq1->cref_stack->nd_visi = iseq0->cref_stack->nd_visi;
+	if (iseq0->cref_stack->nd_next) {
+	    RB_OBJ_WRITE(iseq1->cref_stack, &iseq1->cref_stack->nd_next, iseq0->cref_stack->nd_next);
+	}
+	RB_OBJ_WRITE(iseq1->self, &iseq1->klass, newcbase);
+    }
+
+    return newiseq;
+}
+
+VALUE
+rb_iseq_parameters(const rb_iseq_t *iseq, int is_proc)
+{
+    int i, r;
+    VALUE a, args = rb_ary_new2(iseq->param.size);
+    ID req, opt, rest, block, key, keyrest;
+#define PARAM_TYPE(type) rb_ary_push(a = rb_ary_new2(2), ID2SYM(type))
+#define PARAM_ID(i) iseq->local_table[(i)]
+#define PARAM(i, type) (		      \
+	PARAM_TYPE(type),		      \
+	rb_id2str(PARAM_ID(i)) ?	      \
+	rb_ary_push(a, ID2SYM(PARAM_ID(i))) : \
+	a)
+
+    CONST_ID(req, "req");
+    CONST_ID(opt, "opt");
+    if (is_proc) {
+	for (i = 0; i < iseq->param.lead_num; i++) {
+	    PARAM_TYPE(opt);
+	    rb_ary_push(a, rb_id2str(PARAM_ID(i)) ? ID2SYM(PARAM_ID(i)) : Qnil);
+	    rb_ary_push(args, a);
+	}
+    }
+    else {
+	for (i = 0; i < iseq->param.lead_num; i++) {
+	    rb_ary_push(args, PARAM(i, req));
+	}
+    }
+    r = iseq->param.lead_num + iseq->param.opt_num;
+    for (; i < r; i++) {
+	PARAM_TYPE(opt);
+	if (rb_id2str(PARAM_ID(i))) {
+	    rb_ary_push(a, ID2SYM(PARAM_ID(i)));
+	}
+	rb_ary_push(args, a);
+    }
+    if (iseq->param.flags.has_rest) {
+	CONST_ID(rest, "rest");
+	rb_ary_push(args, PARAM(iseq->param.rest_start, rest));
+    }
+    r = iseq->param.post_start + iseq->param.post_num;
+    if (is_proc) {
+	for (i = iseq->param.post_start; i < r; i++) {
+	    PARAM_TYPE(opt);
+	    rb_ary_push(a, rb_id2str(PARAM_ID(i)) ? ID2SYM(PARAM_ID(i)) : Qnil);
+	    rb_ary_push(args, a);
+	}
+    }
+    else {
+	for (i = iseq->param.post_start; i < r; i++) {
+	    rb_ary_push(args, PARAM(i, req));
+	}
+    }
+    if (iseq->param.flags.has_kw) {
+	i = 0;
+	if (iseq->param.keyword->required_num > 0) {
+	    ID keyreq;
+	    CONST_ID(keyreq, "keyreq");
+	    for (; i < iseq->param.keyword->required_num; i++) {
+		PARAM_TYPE(keyreq);
+		if (rb_id2str(iseq->param.keyword->table[i])) {
+		    rb_ary_push(a, ID2SYM(iseq->param.keyword->table[i]));
+		}
+		rb_ary_push(args, a);
+	    }
+	}
+	CONST_ID(key, "key");
+	for (; i < iseq->param.keyword->num; i++) {
+	    PARAM_TYPE(key);
+	    if (rb_id2str(iseq->param.keyword->table[i])) {
+		rb_ary_push(a, ID2SYM(iseq->param.keyword->table[i]));
+	    }
+	    rb_ary_push(args, a);
+	}
+    }
+    if (iseq->param.flags.has_kwrest) {
+	CONST_ID(keyrest, "keyrest");
+	rb_ary_push(args, PARAM(iseq->param.keyword->rest_start, keyrest));
+    }
+    if (iseq->param.flags.has_block) {
+	CONST_ID(block, "block");
+	rb_ary_push(args, PARAM(iseq->param.block_start, block));
+    }
+    return args;
+}
+
+VALUE
+rb_iseq_defined_string(enum defined_type type)
+{
+    static const char expr_names[][18] = {
+	"nil",
+	"instance-variable",
+	"local-variable",
+	"global-variable",
+	"class variable",
+	"constant",
+	"method",
+	"yield",
+	"super",
+	"self",
+	"true",
+	"false",
+	"assignment",
+	"expression",
+    };
+    const char *estr;
+    VALUE *defs, str;
+
+    if ((unsigned)(type - 1) >= (unsigned)numberof(expr_names)) return 0;
+    estr = expr_names[type - 1];
+    if (!estr[0]) return 0;
+    defs = GET_VM()->defined_strings;
+    if (!defs) {
+	defs = ruby_xcalloc(numberof(expr_names), sizeof(VALUE));
+	GET_VM()->defined_strings = defs;
+    }
+    str = defs[type-1];
+    if (!str) {
+	str = rb_str_new_cstr(estr);
+	OBJ_FREEZE(str);
+	defs[type-1] = str;
+	rb_gc_register_mark_object(str);
+    }
+    return str;
+}
+
+/* ruby2cext */
+
+VALUE
+rb_iseq_build_for_ruby2cext(
+    const rb_iseq_t *iseq_template,
+    const rb_insn_func_t *func,
+    const struct iseq_line_info_entry *line_info_table,
+    const char **local_table,
+    const VALUE *arg_opt_table,
+    const struct iseq_catch_table_entry *catch_table,
+    const char *name,
+    const char *path,
+    const unsigned short first_lineno)
+{
+    unsigned long i;
+    VALUE iseqval = iseq_alloc(rb_cISeq);
+    rb_iseq_t *iseq;
+    GetISeqPtr(iseqval, iseq);
+
+    /* copy iseq */
+    MEMCPY(iseq, iseq_template, rb_iseq_t, 1); /* TODO: write barrier, *iseq = *iseq_template; */
+    RB_OBJ_WRITE(iseq->self, &iseq->location.label, rb_str_new2(name));
+    RB_OBJ_WRITE(iseq->self, &iseq->location.path, rb_str_new2(path));
+    iseq->location.first_lineno = UINT2NUM(first_lineno);
+    RB_OBJ_WRITE(iseq->self, &iseq->mark_ary, 0);
+    iseq->self = iseqval;
+
+    iseq->iseq_encoded = ALLOC_N(VALUE, iseq->iseq_size);
+
+    for (i=0; i<iseq->iseq_size; i+=2) {
+	iseq->iseq_encoded[i] = BIN(opt_call_c_function);
+	iseq->iseq_encoded[i+1] = (VALUE)func;
+    }
+
+    rb_iseq_translate_threaded_code(iseq);
+
+#define ALLOC_AND_COPY(dst, src, type, size) do { \
+  if (size) { \
+      (dst) = ALLOC_N(type, (size)); \
+      MEMCPY((dst), (src), type, (size)); \
+  } \
+} while (0)
+
+    ALLOC_AND_COPY(iseq->line_info_table, line_info_table,
+		   struct iseq_line_info_entry, iseq->line_info_size);
+
+    /*
+     * FIXME: probably broken, but this function is probably unused
+     * and should be removed
+     */
+    if (iseq->catch_table) {
+	MEMCPY(&iseq->catch_table->entries, catch_table,
+	    struct iseq_catch_table_entry, iseq->catch_table->size);
+    }
+
+    ALLOC_AND_COPY(iseq->param.opt_table, arg_opt_table, VALUE, iseq->param.opt_num + 1);
+
+    set_relation(iseq, 0);
+
+    return iseqval;
+}
+
+/* Experimental tracing support: trace(line) -> trace(specified_line)
+ * MRI Specific.
+ */
+
+int
+rb_iseq_line_trace_each(VALUE iseqval, int (*func)(int line, rb_event_flag_t *events_ptr, void *d), void *data)
+{
+    int trace_num = 0;
+    unsigned int pos;
+    size_t insn;
+    rb_iseq_t *iseq;
+    int cont = 1;
+    VALUE *iseq_original;
+    GetISeqPtr(iseqval, iseq);
+
+    iseq_original = rb_iseq_original_iseq(iseq);
+    for (pos = 0; cont && pos < iseq->iseq_size; pos += insn_len(insn)) {
+	insn = iseq_original[pos];
+
+	if (insn == BIN(trace)) {
+	    rb_event_flag_t current_events;
+
+	    current_events = (rb_event_flag_t)iseq_original[pos+1];
+
+	    if (current_events & RUBY_EVENT_LINE) {
+		rb_event_flag_t events = current_events & RUBY_EVENT_SPECIFIED_LINE;
+		trace_num++;
+
+		if (func) {
+		    int line = find_line_no(iseq, pos);
+		    /* printf("line: %d\n", line); */
+		    cont = (*func)(line, &events, data);
+		    if (current_events != events) {
+			iseq_original[pos+1] = iseq->iseq_encoded[pos+1] =
+			  (VALUE)(current_events | (events & RUBY_EVENT_SPECIFIED_LINE));
+		    }
+		}
+	    }
+	}
+    }
+    return trace_num;
+}
+
+static int
+collect_trace(int line, rb_event_flag_t *events_ptr, void *ptr)
+{
+    VALUE result = (VALUE)ptr;
+    rb_ary_push(result, INT2NUM(line));
+    return 1;
+}
+
+/*
+ * <b>Experimental MRI specific feature, only available as C level api.</b>
+ *
+ * Returns all +specified_line+ events.
+ */
+VALUE
+rb_iseq_line_trace_all(VALUE iseqval)
+{
+    VALUE result = rb_ary_new();
+    rb_iseq_line_trace_each(iseqval, collect_trace, (void *)result);
+    return result;
+}
+
+struct set_specifc_data {
+    int pos;
+    int set;
+    int prev; /* 1: set, 2: unset, 0: not found */
+};
+
+static int
+line_trace_specify(int line, rb_event_flag_t *events_ptr, void *ptr)
+{
+    struct set_specifc_data *data = (struct set_specifc_data *)ptr;
+
+    if (data->pos == 0) {
+	data->prev = *events_ptr & RUBY_EVENT_SPECIFIED_LINE ? 1 : 2;
+	if (data->set) {
+	    *events_ptr = *events_ptr | RUBY_EVENT_SPECIFIED_LINE;
+	}
+	else {
+	    *events_ptr = *events_ptr & ~RUBY_EVENT_SPECIFIED_LINE;
+	}
+	return 0; /* found */
+    }
+    else {
+	data->pos--;
+	return 1;
+    }
+}
+
+/*
+ * <b>Experimental MRI specific feature, only available as C level api.</b>
+ *
+ * Set a +specified_line+ event at the given line position, if the +set+
+ * parameter is +true+.
+ *
+ * This method is useful for building a debugger breakpoint at a specific line.
+ *
+ * A TypeError is raised if +set+ is not boolean.
+ *
+ * If +pos+ is a negative integer a TypeError exception is raised.
+ */
+VALUE
+rb_iseq_line_trace_specify(VALUE iseqval, VALUE pos, VALUE set)
+{
+    struct set_specifc_data data;
+
+    data.prev = 0;
+    data.pos = NUM2INT(pos);
+    if (data.pos < 0) rb_raise(rb_eTypeError, "`pos' is negative");
+
+    switch (set) {
+      case Qtrue:  data.set = 1; break;
+      case Qfalse: data.set = 0; break;
+      default:
+	rb_raise(rb_eTypeError, "`set' should be true/false");
+    }
+
+    rb_iseq_line_trace_each(iseqval, line_trace_specify, (void *)&data);
+
+    if (data.prev == 0) {
+	rb_raise(rb_eTypeError, "`pos' is out of range.");
+    }
+    return data.prev == 1 ? Qtrue : Qfalse;
+}
+
+/*
+ *  Document-class: RubyVM::InstructionSequence
+ *
+ *  The InstructionSequence class represents a compiled sequence of
+ *  instructions for the Ruby Virtual Machine.
+ *
+ *  With it, you can get a handle to the instructions that make up a method or
+ *  a proc, compile strings of Ruby code down to VM instructions, and
+ *  disassemble instruction sequences to strings for easy inspection. It is
+ *  mostly useful if you want to learn how the Ruby VM works, but it also lets
+ *  you control various settings for the Ruby iseq compiler.
+ *
+ *  You can find the source for the VM instructions in +insns.def+ in the Ruby
+ *  source.
+ *
+ *  The instruction sequence results will almost certainly change as Ruby
+ *  changes, so example output in this documentation may be different from what
+ *  you see.
+ */
+
+void
+Init_ISeq(void)
+{
+    /* declare ::RubyVM::InstructionSequence */
+    rb_cISeq = rb_define_class_under(rb_cRubyVM, "InstructionSequence", rb_cObject);
+    rb_define_alloc_func(rb_cISeq, iseq_alloc);
+    rb_define_method(rb_cISeq, "inspect", iseq_inspect, 0);
+    rb_define_method(rb_cISeq, "disasm", rb_iseq_disasm, 0);
+    rb_define_method(rb_cISeq, "disassemble", rb_iseq_disasm, 0);
+    rb_define_method(rb_cISeq, "to_a", iseq_to_a, 0);
+    rb_define_method(rb_cISeq, "eval", iseq_eval, 0);
+
+    /* location APIs */
+    rb_define_method(rb_cISeq, "path", rb_iseq_path, 0);
+    rb_define_method(rb_cISeq, "absolute_path", rb_iseq_absolute_path, 0);
+    rb_define_method(rb_cISeq, "label", rb_iseq_label, 0);
+    rb_define_method(rb_cISeq, "base_label", rb_iseq_base_label, 0);
+    rb_define_method(rb_cISeq, "first_lineno", rb_iseq_first_lineno, 0);
+
+#if 0
+    /* Now, it is experimental. No discussions, no tests. */
+    /* They can be used from C level. Please give us feedback. */
+    rb_define_method(rb_cISeq, "line_trace_all", rb_iseq_line_trace_all, 0);
+    rb_define_method(rb_cISeq, "line_trace_specify", rb_iseq_line_trace_specify, 2);
+#else
+    (void)rb_iseq_line_trace_all;
+    (void)rb_iseq_line_trace_specify;
+#endif
+
+#if 0 /* TBD */
+    rb_define_private_method(rb_cISeq, "marshal_dump", iseq_marshal_dump, 0);
+    rb_define_private_method(rb_cISeq, "marshal_load", iseq_marshal_load, 1);
+#endif
+
+    /* disable this feature because there is no verifier. */
+    /* rb_define_singleton_method(rb_cISeq, "load", iseq_s_load, -1); */
+    (void)iseq_s_load;
+
+    rb_define_singleton_method(rb_cISeq, "compile", iseq_s_compile, -1);
+    rb_define_singleton_method(rb_cISeq, "new", iseq_s_compile, -1);
+    rb_define_singleton_method(rb_cISeq, "compile_file", iseq_s_compile_file, -1);
+    rb_define_singleton_method(rb_cISeq, "compile_option", iseq_s_compile_option_get, 0);
+    rb_define_singleton_method(rb_cISeq, "compile_option=", iseq_s_compile_option_set, 1);
+    rb_define_singleton_method(rb_cISeq, "disasm", iseq_s_disasm, 1);
+    rb_define_singleton_method(rb_cISeq, "disassemble", iseq_s_disasm, 1);
+    rb_define_singleton_method(rb_cISeq, "of", iseq_s_of, 1);
+}