ruby--ruby/insnhelper.ci

/* -*-c-*- */
/**********************************************************************

  insnhelper.ci - instruction helper functions.

  $Author$
  $Date$

  Copyright (C) 2007 Koichi Sasada

**********************************************************************/

/* finish iseq array */

#include "insns.inc"

#if OPT_STACK_CACHING
static VALUE yarv_finish_insn_seq[1] = { BIN(finish_SC_ax_ax) };
#elif OPT_CALL_THREADED_CODE
static VALUE const yarv_finish_insn_seq[1] = { 0 };
#else
static VALUE yarv_finish_insn_seq[1] = { BIN(finish) };
#endif

/* control stack frame */

static inline rb_control_frame_t *
vm_push_frame(rb_thread_t *th, rb_iseq_t *iseq, VALUE magic,
	      VALUE self, VALUE specval, VALUE *pc,
	      VALUE *sp, VALUE *lfp, int local_size)
{
    VALUE *dfp;
    rb_control_frame_t *cfp;
    int i;

    /* nil initialize */
    for (i=0; i < local_size; i++) {
	*sp = Qnil;
	sp++;
    }

    /* set special val */
    *sp = GC_GUARDED_PTR(specval);
    dfp = sp;

    if (lfp == 0) {
	lfp = sp;
    }

    cfp = th->cfp = th->cfp - 1;
    cfp->pc = pc;
    cfp->sp = sp + 1;
    cfp->bp = sp + 1;
    cfp->iseq = iseq;
    cfp->magic = magic;
    cfp->self = self;
    cfp->lfp = lfp;
    cfp->dfp = dfp;
    cfp->proc = 0;

#define COLLECT_PROFILE 0
#if COLLECT_PROFILE
    cfp->prof_time_self = clock();
    cfp->prof_time_chld = 0;
#endif

    return cfp;
}

static inline void
vm_pop_frame(rb_thread_t *th)
{
#if COLLECT_PROFILE
    rb_control_frame_t *cfp = th->cfp;

    if (RUBY_VM_NORMAL_ISEQ_P(cfp->iseq)) {
	VALUE current_time = clock();
	rb_control_frame_t *cfp = th->cfp;
	cfp->prof_time_self = current_time - cfp->prof_time_self;
	(cfp+1)->prof_time_chld += cfp->prof_time_self;

	cfp->iseq->profile.count++;
	cfp->iseq->profile.time_cumu = cfp->prof_time_self;
	cfp->iseq->profile.time_self = cfp->prof_time_self - cfp->prof_time_chld;
    }
    else if (0 /* c method? */) {

    }
#endif
    th->cfp = RUBY_VM_PREVIOUS_CONTROL_FRAME(th->cfp);
}

/* method dispatch */

static inline int
vm_callee_setup_arg(rb_thread_t *th, rb_iseq_t *iseq,
		    int argc, VALUE *argv, rb_block_t **block)
{
    const int m = iseq->argc;
    const int orig_argc = argc;

    if (iseq->arg_simple) {
	/* simple check */
	if (argc != m) {
	    rb_raise(rb_eArgError, "wrong number of arguments (%d for %d)",
		     argc, m);
	}
	return 0;
    }
    else {
	VALUE * const dst = argv;
	int opt_pc = 0;

	/* mandatory */
	if (argc < (m + iseq->arg_post_len)) { /* check with post arg */
	    rb_raise(rb_eArgError, "wrong number of arguments (%d for %d)",
		     argc, m + iseq->arg_post_len);
	}

	argv += m;
	argc -= m;

	/* post arguments */
	if (iseq->arg_post_len) {
	    int i;

	    if (!(orig_argc < iseq->arg_post_start)) {
		VALUE *new_argv = ALLOCA_N(VALUE, argc);
		MEMCPY(new_argv, argv, VALUE, argc);
		argv = new_argv;
	    }

	    for (i=0; i<iseq->arg_post_len; i++) {
		dst[iseq->arg_post_start + iseq->arg_post_len - (i + 1)] = argv[argc - 1];
		argc = argc - 1;
	    }
	}

	/* opt arguments */
	if (iseq->arg_opts) {
	    const int opts = iseq->arg_opts - 1 /* no opt */;

	    if (iseq->arg_rest == -1 && argc > opts) {
		rb_raise(rb_eArgError, "wrong number of arguments (%d for %d)", orig_argc, m + opts);
	    }

	    if (argc > opts) {
		argc -= opts;
		argv += opts;
		opt_pc = iseq->arg_opt_tbl[opts]; /* no opt */
	    }
	    else {
		opt_pc = iseq->arg_opt_tbl[argc];
		argc = 0;
	    }
	}

	/* rest arguments */
	if (iseq->arg_rest != -1) {
	    dst[iseq->arg_rest] = rb_ary_new4(argc, argv);
	}

	/* block arguments */
	if (block && iseq->arg_block != -1) {
	    VALUE blockval = Qnil;
	    rb_block_t * const blockptr = *block;

	    if (blockptr) {
		/* make Proc object */
		if (blockptr->proc == 0) {
		    rb_proc_t *proc;

		    th->mark_stack_len = orig_argc; /* for GC */
		    blockval = vm_make_proc(th, th->cfp, blockptr);
		    th->mark_stack_len = 0;

		    GetProcPtr(blockval, proc);
		    *block = &proc->block;
		}
		else {
		    blockval = blockptr->proc;
		}
	    }

	    dst[iseq->arg_block] = blockval; /* Proc or nil */
	}

	return opt_pc;
    }
}

static inline int
caller_setup_args(rb_thread_t *th, rb_control_frame_t *cfp, VALUE flag,
		  int argc, rb_iseq_t *blockiseq, rb_block_t **block)
{
    rb_block_t *blockptr = 0;

    if (block) {
	if (flag & VM_CALL_ARGS_BLOCKARG_BIT) {
	    rb_proc_t *po;
	    VALUE proc;

	    proc = *(--cfp->sp);

	    if (proc != Qnil) {
		if (!rb_obj_is_proc(proc)) {
		    proc = rb_check_convert_type(proc, T_DATA, "Proc", "to_proc");
		    if (!rb_obj_is_proc(proc)) {
			rb_raise(rb_eTypeError,
				 "wrong argument type %s (expected Proc)",
				 rb_obj_classname(proc));
		    }
		}
		GetProcPtr(proc, po);
		blockptr = &po->block;
		RUBY_VM_GET_BLOCK_PTR_IN_CFP(cfp)->proc = proc;
		*block = blockptr;
	    }
	}
	else if (blockiseq) {
	    blockptr = RUBY_VM_GET_BLOCK_PTR_IN_CFP(cfp);
	    blockptr->iseq = blockiseq;
	    blockptr->proc = 0;
	    *block = blockptr;
	}
    }

    /* expand top of stack? */
    if (flag & VM_CALL_ARGS_SPLAT_BIT) {
	VALUE ary = *(cfp->sp - 1);
	VALUE *ptr;
	int i;
	VALUE tmp = rb_check_convert_type(ary, T_ARRAY, "Array", "to_splat");

	if (NIL_P(tmp)) {
	    /* do nothing */
	}
	else {
	    int len = RARRAY_LEN(tmp);
	    ptr = RARRAY_PTR(tmp);
	    cfp->sp -= 1;

	    CHECK_STACK_OVERFLOW(cfp, len);

	    for (i = 0; i < len; i++) {
		*cfp->sp++ = ptr[i];
	    }
	    argc += i-1;
	}
    }

    return argc;
}

static inline VALUE
call_cfunc(VALUE (*func)(), VALUE recv, int len, int argc, const VALUE *argv)
{
    /* printf("len: %d, argc: %d\n", len, argc); */

    if (len >= 0 && argc != len) {
	rb_raise(rb_eArgError, "wrong number of arguments(%d for %d)",
		 argc, len);
    }

    switch (len) {
      case -2:
	return (*func) (recv, rb_ary_new4(argc, argv));
	break;
      case -1:
	return (*func) (argc, argv, recv);
	break;
      case 0:
	return (*func) (recv);
	break;
      case 1:
	return (*func) (recv, argv[0]);
	break;
      case 2:
	return (*func) (recv, argv[0], argv[1]);
	break;
      case 3:
	return (*func) (recv, argv[0], argv[1], argv[2]);
	break;
      case 4:
	return (*func) (recv, argv[0], argv[1], argv[2], argv[3]);
	break;
      case 5:
	return (*func) (recv, argv[0], argv[1], argv[2], argv[3], argv[4]);
	break;
      case 6:
	return (*func) (recv, argv[0], argv[1], argv[2], argv[3], argv[4],
			argv[5]);
	break;
      case 7:
	return (*func) (recv, argv[0], argv[1], argv[2], argv[3], argv[4],
			argv[5], argv[6]);
	break;
      case 8:
	return (*func) (recv, argv[0], argv[1], argv[2], argv[3], argv[4],
			argv[5], argv[6], argv[7]);
	break;
      case 9:
	return (*func) (recv, argv[0], argv[1], argv[2], argv[3], argv[4],
			argv[5], argv[6], argv[7], argv[8]);
	break;
      case 10:
	return (*func) (recv, argv[0], argv[1], argv[2], argv[3], argv[4],
			argv[5], argv[6], argv[7], argv[8], argv[9]);
	break;
      case 11:
	return (*func) (recv, argv[0], argv[1], argv[2], argv[3], argv[4],
			argv[5], argv[6], argv[7], argv[8], argv[9],
			argv[10]);
	break;
      case 12:
	return (*func) (recv, argv[0], argv[1], argv[2], argv[3], argv[4],
			argv[5], argv[6], argv[7], argv[8], argv[9],
			argv[10], argv[11]);
	break;
      case 13:
	return (*func) (recv, argv[0], argv[1], argv[2], argv[3], argv[4],
			argv[5], argv[6], argv[7], argv[8], argv[9], argv[10],
			argv[11], argv[12]);
	break;
      case 14:
	return (*func) (recv, argv[0], argv[1], argv[2], argv[3], argv[4],
			argv[5], argv[6], argv[7], argv[8], argv[9], argv[10],
			argv[11], argv[12], argv[13]);
	break;
      case 15:
	return (*func) (recv, argv[0], argv[1], argv[2], argv[3], argv[4],
			argv[5], argv[6], argv[7], argv[8], argv[9], argv[10],
			argv[11], argv[12], argv[13], argv[14]);
	break;
      default:
	rb_raise(rb_eArgError, "too many arguments(%d)", len);
	break;
    }
    return Qnil;		/* not reached */
}

static inline VALUE
vm_call_cfunc(rb_thread_t *th, rb_control_frame_t *reg_cfp, int num,
	      ID id, VALUE recv, VALUE klass, NODE *mn, rb_block_t *blockptr)
{
    VALUE val;

    EXEC_EVENT_HOOK(th, RUBY_EVENT_C_CALL, recv, id, klass);
    {
	rb_control_frame_t *cfp =
	  vm_push_frame(th, 0, FRAME_MAGIC_CFUNC,
			recv, (VALUE) blockptr, 0, reg_cfp->sp, 0, 1);

	cfp->method_id = id;
	cfp->method_klass = klass;

	reg_cfp->sp -= num + 1;

	val = call_cfunc(mn->nd_cfnc, recv, mn->nd_argc, num, reg_cfp->sp + 1);

	if (reg_cfp != th->cfp + 1) {
	    rb_bug("cfp consistency error - send");
	}
	vm_pop_frame(th);
    }
    EXEC_EVENT_HOOK(th, RUBY_EVENT_C_RETURN, recv, id, klass);

    return val;
}

static inline VALUE
vm_call_bmethod(rb_thread_t *th, ID id, VALUE procval, VALUE recv,
		VALUE klass, int argc, VALUE *argv)
{
    rb_control_frame_t *cfp = th->cfp;
    rb_proc_t *proc;
    VALUE val;

    /* control block frame */
    (cfp-2)->method_id = id;
    (cfp-2)->method_klass = klass;

    GetProcPtr(procval, proc);
    val = vm_invoke_proc(th, proc, recv, argc, argv);
    return val;
}

static inline VALUE
vm_method_missing(rb_thread_t *th, ID id, VALUE recv, int num,
		  rb_block_t *blockptr, int opt)
{
    rb_control_frame_t *reg_cfp = th->cfp;
    VALUE *argv = STACK_ADDR_FROM_TOP(num + 1);
    VALUE val;
    argv[0] = ID2SYM(id);
    th->method_missing_reason = opt;
    th->passed_block = blockptr;
    val = rb_funcall2(recv, idMethodMissing, num + 1, argv);
    POPN(num + 1);
    return val;
}

static inline void
vm_setup_method(rb_thread_t *th, rb_control_frame_t *cfp,
		int argc, rb_block_t *blockptr, VALUE flag,
		VALUE iseqval, VALUE recv, VALUE klass)
{
    rb_iseq_t *iseq;
    int opt_pc, i;
    VALUE *rsp = cfp->sp - argc;
    VALUE *sp;

    /* TODO: eliminate it */
    GetISeqPtr(iseqval, iseq);

    opt_pc = vm_callee_setup_arg(th, iseq, argc, rsp, &blockptr);
    sp = rsp + iseq->arg_size;

    /* stack overflow check */
    CHECK_STACK_OVERFLOW(cfp, iseq->stack_max + 0x10);

    if (flag & VM_CALL_TAILCALL_BIT) {
	VALUE *p_rsp;
	cfp = ++th->cfp; /* pop cf */
	p_rsp = th->cfp->sp;

	/* copy arguments */
	for (i=0; i < (sp - rsp); i++) {
	    p_rsp[i] = rsp[i];
	}

	sp -= rsp - p_rsp;

	/* clear local variables */
	for (i = 0; i < iseq->local_size - iseq->arg_size; i++) {
	    *sp++ = Qnil;
	}

	vm_push_frame(th, iseq,
		      FRAME_MAGIC_METHOD, recv, (VALUE) blockptr,
		      iseq->iseq_encoded + opt_pc, sp, 0, 0);
    }
    else {
	if (0) printf("local_size: %d, arg_size: %d\n",
		      iseq->local_size, iseq->arg_size);

	/* clear local variables */
	for (i = 0; i < iseq->local_size - iseq->arg_size; i++) {
	    *sp++ = Qnil;
	}

	vm_push_frame(th, iseq,
		      FRAME_MAGIC_METHOD, recv, (VALUE) blockptr,
		      iseq->iseq_encoded + opt_pc, sp, 0, 0);

	cfp->sp = rsp - 1 /* recv */;
    }
}

static inline VALUE
vm_call_method(rb_thread_t *th, rb_control_frame_t *cfp,
	       int num, rb_block_t *blockptr, VALUE flag,
	       ID id, NODE *mn, VALUE recv, VALUE klass)
{
    VALUE val;

  start_method_dispatch:

    /* method missing */
    if (mn == 0) {
	if (id == idMethodMissing) {
	    rb_bug("method missing");
	}
	else {
	    int stat = 0;
	    if (flag & VM_CALL_VCALL_BIT) {
		stat |= NOEX_VCALL;
	    }
	    if (flag & VM_CALL_SUPER_BIT) {
		stat |= NOEX_SUPER;
	    }
	    val = vm_method_missing(th, id, recv, num, blockptr, stat);
	}
    }
    else if (!(flag & VM_CALL_FCALL_BIT) &&
	     (mn->nd_noex & NOEX_MASK) & NOEX_PRIVATE) {
	int stat = NOEX_PRIVATE;
	if (flag & VM_CALL_VCALL_BIT) {
	    stat |= NOEX_VCALL;
	}
	val = vm_method_missing(th, id, recv, num, blockptr, stat);
    }
    else if ((mn->nd_noex & NOEX_MASK) & NOEX_PROTECTED) {
	VALUE defined_class = mn->nd_clss;

	if (TYPE(defined_class) == T_ICLASS) {
	    defined_class = RBASIC(defined_class)->klass;
	}

	if (!rb_obj_is_kind_of(cfp->self, rb_class_real(defined_class))) {
	    val = vm_method_missing(th, id, recv, num, blockptr, NOEX_PROTECTED);
	}
	else {
	    goto normal_method_dispatch;
	}
    }

    /* dispatch method */
    else {
	NODE *node;
      normal_method_dispatch:

	node = mn->nd_body;
	switch (nd_type(node)) {
	  case RUBY_VM_METHOD_NODE:{
	      vm_setup_method(th, cfp, num, blockptr, flag, (VALUE)node->nd_body, recv, klass);
	      return Qundef;
	  }
	  case NODE_CFUNC:{
	      val = vm_call_cfunc(th, cfp, num, id, recv, klass, node, blockptr);
	      break;
	  }
	  case NODE_ATTRSET:{
	      val = rb_ivar_set(recv, node->nd_vid, *(cfp->sp - 1));
	      cfp->sp -= 2;
	      break;
	  }
	  case NODE_IVAR:{
	      val = rb_ivar_get(recv, node->nd_vid);
	      cfp->sp -= 1;
	      break;
	  }
	  case NODE_BMETHOD:{
	      VALUE *argv = cfp->sp - num;
	      val = vm_call_bmethod(th, id, node->nd_cval, recv, klass, num, argv);
	      cfp->sp += - num - 1;
	      break;
	  }
	  case NODE_ZSUPER:{
	      klass = RCLASS(mn->nd_clss)->super;
	      mn = rb_method_node(klass, id);

	      if (mn != 0) {
		  goto normal_method_dispatch;
	      }
	      else {
		  goto start_method_dispatch;
	      }
	  }
	  default:{
	      printf("node: %s\n", ruby_node_name(nd_type(node)));
	      rb_bug("eval_invoke_method: unreachable");
	      /* unreachable */
	      break;
	  }
	}
    }

    RUBY_VM_CHECK_INTS();
    return val;
}

/* yield */

static inline int
block_proc_is_lambda(VALUE procval)
{
    rb_proc_t *proc;

    if (procval) {
	GetProcPtr(procval, proc);
	return proc->is_lambda;
    }
    else {
	return 0;
    }
}

static inline VALUE
vm_yield_with_cfunc(rb_thread_t *th, rb_block_t *block,
		    VALUE self, int argc, VALUE *argv)
{
    NODE *ifunc = (NODE *) block->iseq;
    VALUE val;
    VALUE arg;
    int lambda = block_proc_is_lambda(block->proc);

    if (lambda) {
	arg = rb_ary_new4(argc, argv);
    }
    else {
	if (argc == 1) {
	    arg = *argv;
	}
	else if (argc > 1) {
	    arg = rb_ary_new4(argc, argv);
	}
	else {
	    arg = rb_ary_new();
	}
    }

    vm_push_frame(th, 0, FRAME_MAGIC_IFUNC,
		  self, (VALUE)block->dfp,
		  0, th->cfp->sp, block->lfp, 1);

    val = (*ifunc->nd_cfnc) (arg, ifunc->nd_tval, Qnil);

    th->cfp++;
    return val;
}

static inline int
vm_yield_setup_args(rb_thread_t *th, rb_iseq_t *iseq,
		    int argc, VALUE *argv, int lambda)
{
    if (0) { /* for debug */
	printf("     argc: %d\n", argc);
	printf("iseq argc: %d\n", iseq->argc);
	printf("iseq opts: %d\n", iseq->arg_opts);
	printf("iseq rest: %d\n", iseq->arg_rest);
	printf("iseq post: %d\n", iseq->arg_post_len);
	printf("iseq blck: %d\n", iseq->arg_block);
	printf("iseq smpl: %d\n", iseq->arg_simple);
	printf("   lambda: %s\n", lambda ? "true" : "false");
    }

    if (lambda) {
	/* call as method */
	if (iseq->arg_block != -1) {
	    volatile VALUE procval = Qnil;

	    if (rb_block_given_p()) {
		rb_block_t *blockptr;
		rb_proc_t *proc;
		procval = rb_block_proc();
		GetProcPtr(procval, proc);
		blockptr = &proc->block;
		return vm_callee_setup_arg(th, iseq, argc, argv, &blockptr);
	    }
	}
	return vm_callee_setup_arg(th, iseq, argc, argv, 0);
    }
    else {
	int i;
	const int m = iseq->argc;

	th->mark_stack_len = argc;

	/*
	 * yield [1, 2]
	 *  => {|a|} => a = [1, 2]
	 *  => {|a, b|} => a, b = [1, 2]
	 */
	if (iseq->arg_simple != 2 && m > 0 && argc == 1 && TYPE(argv[0]) == T_ARRAY) {
	    VALUE ary = argv[0];
	    th->mark_stack_len = argc = RARRAY_LEN(ary);

	    CHECK_STACK_OVERFLOW(th->cfp, argc);

	    for (i=0; i<argc; i++) {
		argv[i] = RARRAY_PTR(ary)[i];
	    }
	}

	for (i=argc; i<m; i++) {
	    argv[i] = Qnil;
	}

	if (iseq->arg_rest == -1) {
	    if (m < argc) {
		/*
		 * yield 1, 2
		 * => {|a|} # truncate
		 */
		th->mark_stack_len = argc = m;
	    }
	}
	else {
	    int r = iseq->arg_rest;

	    if (iseq->arg_post_len) {
		int len = iseq->arg_post_len;
		int start = iseq->arg_post_start;
		int rsize = argc - m;
		int psize = rsize;
		VALUE ary;

		if (rsize < 0) rsize = 0;
		if (psize > len) psize = len;

		ary = rb_ary_new4(rsize, &argv[r]);

		if (0) {
		    printf(" argc: %d\n", argc);
		    printf("  len: %d\n", len);
		    printf("start: %d\n", start);
		    printf("rsize: %d\n", rsize);
		}

		/* copy post argument */
		for (i=0; i<psize; i++) {
		    argv[start + psize - i - 1] = rb_ary_pop(ary);
		}

		for (; i<len; i++) {
		    argv[start + i] = Qnil;
		}
		argv[r] = ary;
	    }
	    else {
		if (argc < r) {
		    /* yield 1
		     * => {|a, b, *r|}
		     */
		    for (i=argc; i<r; i++) {
			argv[i] = Qnil;
		    }
		    argv[r] = rb_ary_new();
		}
		else {
		    argv[r] = rb_ary_new4(argc-r, &argv[r]);
		}
	    }

	    th->mark_stack_len = iseq->arg_size;
	}

	/* {|&b|} */
	if (iseq->arg_block != -1) {
	    VALUE proc = Qnil;

	    if (rb_block_given_p()) {
		proc = rb_block_proc();
	    }

	    argv[iseq->arg_block] = proc;
	    th->mark_stack_len = iseq->arg_block + 1;
	}

	th->mark_stack_len = 0;
	return 0;
    }
}

/* cref */

static NODE *
lfp_get_special_cref(VALUE *lfp)
{
    struct RValues *values;
    if (((VALUE)(values = (void *)lfp[-1])) != Qnil && values->basic.klass) {
	return (NODE *)values->basic.klass;
    }
    else {
	return 0;
    }
}

static struct RValues *
new_value(void)
{
    struct RValues *val = RVALUES(rb_newobj());
    OBJSETUP(val, 0, T_VALUES);
    val->v1 = val->v2 = val->v3 = Qnil;
    return val;
}

static VALUE *
lfp_svar(VALUE *lfp, int cnt)
{
    struct RValues *val;
    rb_thread_t *th = GET_THREAD();

    if (th->local_lfp != lfp) {
	val = (struct RValues *)lfp[-1];
	if ((VALUE)val == Qnil) {
	    val = new_value();
	    lfp[-1] = (VALUE)val;
	}
    }
    else {
	val = (struct RValues *)th->local_svar;
	if ((VALUE)val == Qnil) {
	    val = new_value();
	    th->local_svar = (VALUE)val;
	}
    }
    switch (cnt) {
      case -1:
	return &val->basic.klass;
      case 0:
	return &val->v1;
      case 1:
	return &val->v2;
      default:{
	VALUE ary;
	if ((ary = val->v3) == Qnil) {
	    ary = val->v3 = rb_ary_new();
	}
	if (RARRAY_LEN(ary) <= cnt) {
	    rb_ary_store(ary, cnt, Qnil);
	}
	return &RARRAY_PTR(ary)[cnt];
      }
    }
}

static NODE *
get_cref(rb_iseq_t *iseq, VALUE *lfp)
{
    NODE *cref;
    if ((cref = lfp_get_special_cref(lfp)) != 0) {
	/* */
    }
    else if ((cref = iseq->cref_stack) != 0) {
	/* */
    }
    else {
	rb_bug("get_cref: unreachable");
    }
    return cref;
}

static inline VALUE
vm_get_ev_const(rb_thread_t *th, rb_iseq_t *iseq,
		VALUE klass, ID id, int is_defined)
{
    VALUE val;

    if (klass == Qnil) {
	/* in current lexical scope */
	NODE *root_cref = get_cref(iseq, th->cfp->lfp);
	NODE *cref = root_cref;

	while (cref && cref->nd_next) {
	    klass = cref->nd_clss;
	    cref = cref->nd_next;

	    if (klass == 0) {
		continue;
	    }
	    if (NIL_P(klass)) {
		if (is_defined) {
		    /* TODO: check */
		    return 1;
		}
		else {
		    klass = CLASS_OF(th->cfp->self);
		    return rb_const_get(klass, id);
		}
	    }
	  search_continue:
	    if (RCLASS(klass)->iv_tbl &&
		st_lookup(RCLASS(klass)->iv_tbl, id, &val)) {
		if (val == Qundef) {
		    rb_autoload_load(klass, id);
		    goto search_continue;
		}
		else {
		    if (is_defined) {
			return 1;
		    }
		    else {
			return val;
		    }
		}
	    }
	}
	klass = root_cref->nd_clss;
	if (is_defined) {
	    return rb_const_defined(klass, id);
	}
	else {
	    return rb_const_get(klass, id);
	}
    }
    else {
	switch (TYPE(klass)) {
	  case T_CLASS:
	  case T_MODULE:
	    break;
	  default:
	    rb_raise(rb_eTypeError, "%s is not a class/module",
		     RSTRING_PTR(rb_obj_as_string(klass)));
	}
	if (is_defined) {
	    return rb_const_defined(klass, id);
	}
	else {
	    return rb_const_get(klass, id);
	}
    }
}

static inline VALUE
vm_get_cvar_base(rb_thread_t *th, rb_iseq_t *iseq)
{
    NODE *cref = get_cref(iseq, th->cfp->lfp);
    VALUE klass = Qnil;

    if (cref) {
	klass = cref->nd_clss;
	if (!cref->nd_next) {
	    rb_warn("class variable access from toplevel");
	}
    }
    if (NIL_P(klass)) {
	rb_raise(rb_eTypeError, "no class variables available");
    }
    return klass;
}

static inline void
vm_define_method(rb_thread_t *th, VALUE obj,
		   ID id, rb_iseq_t *miseq, rb_num_t is_singleton, NODE *cref)
{
    NODE *newbody;
    int noex = cref->nd_visi;
    VALUE klass = cref->nd_clss;

    if (is_singleton) {
	if (FIXNUM_P(obj) || SYMBOL_P(obj)) {
	    rb_raise(rb_eTypeError,
		     "can't define singleton method \"%s\" for %s",
		     rb_id2name(id), rb_obj_classname(obj));
	}

	if (OBJ_FROZEN(obj)) {
	    rb_error_frozen("object");
	}

	klass = rb_singleton_class(obj);
	noex = NOEX_PUBLIC;
    }

    /* dup */
    COPY_CREF(miseq->cref_stack, cref);
    miseq->klass = klass;
    miseq->defined_method_id = id;
    newbody = NEW_NODE(RUBY_VM_METHOD_NODE, 0, miseq->self, 0);
    rb_add_method(klass, id, newbody, noex);

    if (!is_singleton && noex == NOEX_MODFUNC) {
	rb_add_method(rb_singleton_class(klass), id, newbody, NOEX_PUBLIC);
    }
    INC_VM_STATE_VERSION();
}

static inline NODE *
vm_method_search(VALUE id, VALUE klass, IC ic)
{
    NODE *mn;

#if OPT_INLINE_METHOD_CACHE
    {
	if (LIKELY(klass == ic->ic_klass) &&
	    LIKELY(GET_VM_STATE_VERSION() == ic->ic_vmstat)) {
	    mn = ic->ic_method;
	}
	else {
	    mn = rb_method_node(klass, id);
	    ic->ic_klass = klass;
	    ic->ic_method = mn;
	    ic->ic_vmstat = GET_VM_STATE_VERSION();
	}
    }
#else
    mn = rb_method_node(klass, id);
#endif
    return mn;
}

static VALUE
vm_search_super_klass(VALUE klass, VALUE recv)
{
    if (BUILTIN_TYPE(klass) == T_CLASS) {
	klass = RCLASS(klass)->super;
    }
    else if (BUILTIN_TYPE(klass) == T_MODULE) {
	VALUE k = CLASS_OF(recv);
	while (k) {
	    if (BUILTIN_TYPE(k) == T_ICLASS && RBASIC(k)->klass == klass) {
		klass = RCLASS(k)->super;
		break;
	    }
	    k = RCLASS(k)->super;
	}
    }
    return klass;
}

static void
call_yarv_end_proc(VALUE data)
{
    rb_proc_call(data, rb_ary_new2(0));
}