vm_args.c

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

  vm_args.c - process method call arguments.

  $Author$

  Copyright (C) 2014- Yukihiro Matsumoto

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

NORETURN(static void raise_argument_error(rb_thread_t *th, const rb_iseq_t *iseq, const VALUE exc));
NORETURN(static void argument_arity_error(rb_thread_t *th, const rb_iseq_t *iseq, const int miss_argc, const int min_argc, const int max_argc));
NORETURN(static void argument_kw_error(rb_thread_t *th, const rb_iseq_t *iseq, const char *error, const VALUE keys));
VALUE rb_keyword_error_new(const char *error, VALUE keys); /* class.c */
static VALUE method_missing(VALUE obj, ID id, int argc, const VALUE *argv,
                            enum method_missing_reason call_status);

struct args_info {
    /* basic args info */
    VALUE *argv;
    int argc;
    const struct rb_call_info_kw_arg *kw_arg;

    /* additional args info */
    int rest_index;
    VALUE *kw_argv;
    VALUE rest;
};

enum arg_setup_type {
    arg_setup_method,
    arg_setup_block
};

static inline int
args_argc(struct args_info *args)
{
    if (args->rest == Qfalse) {
        return args->argc;
    }
    else {
        return args->argc + RARRAY_LENINT(args->rest) - args->rest_index;
    }
}

static inline void
args_extend(struct args_info *args, const int min_argc)
{
    int i;

    if (args->rest) {
        args->rest = rb_ary_dup(args->rest);
        VM_ASSERT(args->rest_index == 0);
        for (i=args->argc + RARRAY_LENINT(args->rest); i<min_argc; i++) {
            rb_ary_push(args->rest, Qnil);
        }
    }
    else {
        for (i=args->argc; i<min_argc; i++) {
            args->argv[args->argc++] = Qnil;
        }
    }
}

static inline void
args_reduce(struct args_info *args, int over_argc)
{
    if (args->rest) {
        const long len = RARRAY_LEN(args->rest);

        if (len > over_argc) {
            args->rest = rb_ary_dup(args->rest);
            rb_ary_resize(args->rest, len - over_argc);
            return;
        }
        else {
            args->rest = Qfalse;
            over_argc -= len;
        }
    }

    VM_ASSERT(args->argc >= over_argc);
    args->argc -= over_argc;
}

static inline int
args_check_block_arg0(struct args_info *args, rb_thread_t *th)
{
    VALUE ary = Qnil;

    if (args->rest && RARRAY_LEN(args->rest) == 1) {
        VALUE arg0 = RARRAY_AREF(args->rest, 0);
        ary = rb_check_array_type(arg0);
    }
    else if (args->argc == 1) {
        VALUE arg0 = args->argv[0];
        ary = rb_check_array_type(arg0);
        args->argv[0] = arg0; /* see: https://bugs.ruby-lang.org/issues/8484 */
    }

    if (!NIL_P(ary)) {
        args->rest = ary;
        args->rest_index = 0;
        args->argc = 0;
        return TRUE;
    }

    return FALSE;
}

static inline void
args_copy(struct args_info *args)
{
    if (args->rest != Qfalse) {
        int argc = args->argc;
        args->argc = 0;
        args->rest = rb_ary_dup(args->rest); /* make dup */

        /*
         * argv: [m0, m1, m2, m3]
         * rest: [a0, a1, a2, a3, a4, a5]
         *                ^
         *                rest_index
         *
         * #=> first loop
         *
         * argv: [m0, m1]
         * rest: [m2, m3, a2, a3, a4, a5]
         *        ^
         *        rest_index
         *
         * #=> 2nd loop
         *
         * argv: [] (argc == 0)
         * rest: [m0, m1, m2, m3, a2, a3, a4, a5]
         *        ^
         *        rest_index
         */
        while (args->rest_index > 0 && argc > 0) {
            RARRAY_ASET(args->rest, --args->rest_index, args->argv[--argc]);
        }
        while (argc > 0) {
            rb_ary_unshift(args->rest, args->argv[--argc]);
        }
    }
    else if (args->argc > 0) {
        args->rest = rb_ary_new_from_values(args->argc, args->argv);
        args->rest_index = 0;
        args->argc = 0;
    }
}

static inline const VALUE *
args_rest_argv(struct args_info *args)
{
    return RARRAY_CONST_PTR(args->rest) + args->rest_index;
}

static inline VALUE
args_rest_array(struct args_info *args)
{
    VALUE ary;

    if (args->rest) {
        ary = rb_ary_subseq(args->rest, args->rest_index, RARRAY_LEN(args->rest) - args->rest_index);
        args->rest = 0;
    }
    else {
        ary = rb_ary_new();
    }
    return ary;
}

static int
keyword_hash_p(VALUE *kw_hash_ptr, VALUE *rest_hash_ptr, rb_thread_t *th)
{
    *rest_hash_ptr = rb_check_hash_type(*kw_hash_ptr);

    if (!NIL_P(*rest_hash_ptr)) {
        VALUE hash = rb_extract_keywords(rest_hash_ptr);
        if (!hash) hash = Qnil;
        *kw_hash_ptr = hash;
        return TRUE;
    }
    else {
        *kw_hash_ptr = Qnil;
        return FALSE;
    }
}

static VALUE
args_pop_keyword_hash(struct args_info *args, VALUE *kw_hash_ptr, rb_thread_t *th)
{
    VALUE rest_hash;

    if (args->rest == Qfalse) {
      from_argv:
        VM_ASSERT(args->argc > 0);
        *kw_hash_ptr = args->argv[args->argc-1];

        if (keyword_hash_p(kw_hash_ptr, &rest_hash, th)) {
            if (rest_hash) {
                args->argv[args->argc-1] = rest_hash;
            }
            else {
                args->argc--;
                return TRUE;
            }
        }
    }
    else {
        long len = RARRAY_LEN(args->rest);

        if (len > 0) {
            *kw_hash_ptr = RARRAY_AREF(args->rest, len - 1);

            if (keyword_hash_p(kw_hash_ptr, &rest_hash, th)) {
                if (rest_hash) {
                    RARRAY_ASET(args->rest, len - 1, rest_hash);
                }
                else {
                    args->rest = rb_ary_dup(args->rest);
                    rb_ary_pop(args->rest);
                    return TRUE;
                }
            }
        }
        else {
            goto from_argv;
        }
    }

    return FALSE;
}

static int
args_kw_argv_to_hash(struct args_info *args)
{
    const struct rb_call_info_kw_arg *kw_arg = args->kw_arg;
    const VALUE *const passed_keywords = kw_arg->keywords;
    const int kw_len = kw_arg->keyword_len;
    VALUE h = rb_hash_new_with_size(kw_len);
    const int kw_start = args->argc - kw_len;
    const VALUE * const kw_argv = args->argv + kw_start;
    int i;

    args->argc = kw_start + 1;
    for (i=0; i<kw_len; i++) {
        rb_hash_aset(h, passed_keywords[i], kw_argv[i]);
    }

    args->argv[args->argc - 1] = h;

    return args->argc;
}

static void
args_stored_kw_argv_to_hash(struct args_info *args)
{
    int i;
    const struct rb_call_info_kw_arg *kw_arg = args->kw_arg;
    const VALUE *const passed_keywords = kw_arg->keywords;
    const int passed_keyword_len = kw_arg->keyword_len;
    VALUE h = rb_hash_new_with_size(passed_keyword_len);

    for (i=0; i<passed_keyword_len; i++) {
        rb_hash_aset(h, passed_keywords[i], args->kw_argv[i]);
    }
    args->kw_argv = NULL;

    if (args->rest) {
        args->rest = rb_ary_dup(args->rest);
        rb_ary_push(args->rest, h);
    }
    else {
        args->argv[args->argc++] = h;
    }
}

static inline void
args_setup_lead_parameters(struct args_info *args, int argc, VALUE *locals)
{
    if (args->argc >= argc) {
        /* do noting */
        args->argc -= argc;
        args->argv += argc;
    }
    else {
        int i, j;
        const VALUE *argv = args_rest_argv(args);

        for (i=args->argc, j=0; i<argc; i++, j++) {
            locals[i] = argv[j];
        }
        args->rest_index += argc - args->argc;
        args->argc = 0;
    }
}

static inline void
args_setup_post_parameters(struct args_info *args, int argc, VALUE *locals)
{
    long len;
    args_copy(args);
    len = RARRAY_LEN(args->rest);
    MEMCPY(locals, RARRAY_CONST_PTR(args->rest) + len - argc, VALUE, argc);
    rb_ary_resize(args->rest, len - argc);
}

static inline int
args_setup_opt_parameters(struct args_info *args, int opt_max, VALUE *locals)
{
    int i;

    if (args->argc >= opt_max) {
        args->argc -= opt_max;
        args->argv += opt_max;
        i = opt_max;
    }
    else {
        int j;
        i = args->argc;
        args->argc = 0;

        if (args->rest) {
            int len = RARRAY_LENINT(args->rest);
            const VALUE *argv = RARRAY_CONST_PTR(args->rest);

            for (; i<opt_max && args->rest_index < len; i++, args->rest_index++) {
                locals[i] = argv[args->rest_index];
            }
        }

        /* initialize by nil */
        for (j=i; j<opt_max; j++) {
            locals[j] = Qnil;
        }
    }

    return i;
}

static inline void
args_setup_rest_parameter(struct args_info *args, VALUE *locals)
{
    args_copy(args);
    *locals = args_rest_array(args);
}

static VALUE
make_unknown_kw_hash(const VALUE *passed_keywords, int passed_keyword_len, const VALUE *kw_argv)
{
    int i;
    VALUE obj = rb_ary_tmp_new(1);

    for (i=0; i<passed_keyword_len; i++) {
        if (kw_argv[i] != Qundef) {
            rb_ary_push(obj, passed_keywords[i]);
        }
    }
    return obj;
}

static VALUE
make_rest_kw_hash(const VALUE *passed_keywords, int passed_keyword_len, const VALUE *kw_argv)
{
    int i;
    VALUE obj = rb_hash_new_with_size(passed_keyword_len);

    for (i=0; i<passed_keyword_len; i++) {
        if (kw_argv[i] != Qundef) {
            rb_hash_aset(obj, passed_keywords[i], kw_argv[i]);
        }
    }
    return obj;
}

static inline int
args_setup_kw_parameters_lookup(const ID key, VALUE *ptr, const VALUE *const passed_keywords, VALUE *passed_values, const int passed_keyword_len)
{
    int i;
    const VALUE keyname = ID2SYM(key);

    for (i=0; i<passed_keyword_len; i++) {
        if (keyname == passed_keywords[i]) {
            *ptr = passed_values[i];
            passed_values[i] = Qundef;
            return TRUE;
        }
    }

    return FALSE;
}

static void
args_setup_kw_parameters(VALUE* const passed_values, const int passed_keyword_len, const VALUE *const passed_keywords,
                         const rb_iseq_t * const iseq, VALUE * const locals)
{
    const ID *acceptable_keywords = iseq->body->param.keyword->table;
    const int req_key_num = iseq->body->param.keyword->required_num;
    const int key_num = iseq->body->param.keyword->num;
    const VALUE * const default_values = iseq->body->param.keyword->default_values;
    VALUE missing = 0;
    int i, di, found = 0;
    int unspecified_bits = 0;
    VALUE unspecified_bits_value = Qnil;

    for (i=0; i<req_key_num; i++) {
        ID key = acceptable_keywords[i];
        if (args_setup_kw_parameters_lookup(key, &locals[i], passed_keywords, passed_values, passed_keyword_len)) {
            found++;
        }
        else {
            if (!missing) missing = rb_ary_tmp_new(1);
            rb_ary_push(missing, ID2SYM(key));
        }
    }

    if (missing) argument_kw_error(GET_THREAD(), iseq, "missing", missing);

    for (di=0; i<key_num; i++, di++) {
        if (args_setup_kw_parameters_lookup(acceptable_keywords[i], &locals[i], passed_keywords, passed_values, passed_keyword_len)) {
            found++;
        }
        else {
            if (default_values[di] == Qundef) {
                locals[i] = Qnil;

                if (LIKELY(i < 32)) { /* TODO: 32 -> Fixnum's max bits */
                    unspecified_bits |= 0x01 << di;
                }
                else {
                    if (NIL_P(unspecified_bits_value)) {
                        /* fixnum -> hash */
                        int j;
                        unspecified_bits_value = rb_hash_new();

                        for (j=0; j<32; j++) {
                            if (unspecified_bits & (0x01 << j)) {
                                rb_hash_aset(unspecified_bits_value, INT2FIX(j), Qtrue);
                            }
                        }
                    }
                    rb_hash_aset(unspecified_bits_value, INT2FIX(di), Qtrue);
                }
            }
            else {
                locals[i] = default_values[di];
            }
        }
    }

    if (iseq->body->param.flags.has_kwrest) {
        const int rest_hash_index = key_num + 1;
        locals[rest_hash_index] = make_rest_kw_hash(passed_keywords, passed_keyword_len, passed_values);
    }
    else {
        if (found != passed_keyword_len) {
            VALUE keys = make_unknown_kw_hash(passed_keywords, passed_keyword_len, passed_values);
            argument_kw_error(GET_THREAD(), iseq, "unknown", keys);
        }
    }

    if (NIL_P(unspecified_bits_value)) {
        unspecified_bits_value = INT2FIX(unspecified_bits);
    }
    locals[key_num] = unspecified_bits_value;
}

static inline void
args_setup_kw_rest_parameter(VALUE keyword_hash, VALUE *locals)
{
    locals[0] = NIL_P(keyword_hash) ? rb_hash_new() : rb_hash_dup(keyword_hash);
}

static inline void
args_setup_block_parameter(rb_thread_t *th, struct rb_calling_info *calling, VALUE *locals)
{
    VALUE block_handler = calling->block_handler;
    VALUE blockval = Qnil;

    if (block_handler != VM_BLOCK_HANDLER_NONE) {

        switch (vm_block_handler_type(block_handler)) {
          case block_handler_type_iseq:
          case block_handler_type_ifunc:
            blockval = rb_vm_make_proc(th, VM_BH_TO_CAPT_BLOCK(block_handler), rb_cProc);
            break;
          case block_handler_type_symbol:
            blockval = rb_sym_to_proc(VM_BH_TO_SYMBOL(block_handler));
            break;
          case block_handler_type_proc:
            blockval = VM_BH_TO_PROC(block_handler);
            break;
        }
    }
    *locals = blockval;
}

struct fill_values_arg {
    VALUE *keys;
    VALUE *vals;
    int argc;
};

static int
fill_keys_values(st_data_t key, st_data_t val, st_data_t ptr)
{
    struct fill_values_arg *arg = (struct fill_values_arg *)ptr;
    int i = arg->argc++;
    arg->keys[i] = (VALUE)key;
    arg->vals[i] = (VALUE)val;
    return ST_CONTINUE;
}

static int
setup_parameters_complex(rb_thread_t * const th, const rb_iseq_t * const iseq,
                         struct rb_calling_info *const calling,
                         const struct rb_call_info *ci,
                         VALUE * const locals, const enum arg_setup_type arg_setup_type)
{
    const int min_argc = iseq->body->param.lead_num + iseq->body->param.post_num;
    const int max_argc = (iseq->body->param.flags.has_rest == FALSE) ? min_argc + iseq->body->param.opt_num : UNLIMITED_ARGUMENTS;
    int opt_pc = 0;
    int given_argc;
    struct args_info args_body, *args;
    VALUE keyword_hash = Qnil;
    VALUE * const orig_sp = th->ec.cfp->sp;
    unsigned int i;

    /*
     * Extend SP for GC.
     *
     * [pushed values] [uninitialized values]
     * <- ci->argc -->
     * <- iseq->body->param.size------------>
     * ^ locals        ^ sp
     *
     * =>
     * [pushed values] [initialized values  ]
     * <- ci->argc -->
     * <- iseq->body->param.size------------>
     * ^ locals                             ^ sp
     */
    for (i=calling->argc; i<iseq->body->param.size; i++) {
        locals[i] = Qnil;
    }
    th->ec.cfp->sp = &locals[i];

    /* setup args */
    args = &args_body;
    given_argc = args->argc = calling->argc;
    args->argv = locals;

    if (ci->flag & VM_CALL_KWARG) {
        args->kw_arg = ((struct rb_call_info_with_kwarg *)ci)->kw_arg;

        if (iseq->body->param.flags.has_kw) {
            int kw_len = args->kw_arg->keyword_len;
            /* copy kw_argv */
            args->kw_argv = ALLOCA_N(VALUE, kw_len);
            args->argc -= kw_len;
            given_argc -= kw_len;
            MEMCPY(args->kw_argv, locals + args->argc, VALUE, kw_len);
        }
        else {
            args->kw_argv = NULL;
            given_argc = args_kw_argv_to_hash(args);
        }
    }
    else {
        args->kw_arg = NULL;
        args->kw_argv = NULL;
    }

    if (ci->flag & VM_CALL_ARGS_SPLAT) {
        args->rest = locals[--args->argc];
        args->rest_index = 0;
        given_argc += RARRAY_LENINT(args->rest) - 1;
    }
    else {
        args->rest = Qfalse;
    }

    switch (arg_setup_type) {
      case arg_setup_method:
        break; /* do nothing special */
      case arg_setup_block:
        if (given_argc == 1 &&
            (min_argc > 0 || iseq->body->param.opt_num > 1 ||
             iseq->body->param.flags.has_kw || iseq->body->param.flags.has_kwrest) &&
            !iseq->body->param.flags.ambiguous_param0 &&
            args_check_block_arg0(args, th)) {
            given_argc = RARRAY_LENINT(args->rest);
        }
        break;
    }

    /* argc check */
    if (given_argc < min_argc) {
        if (given_argc == min_argc - 1 && args->kw_argv) {
            args_stored_kw_argv_to_hash(args);
            given_argc = args_argc(args);
        }
        else {
            if (arg_setup_type == arg_setup_block) {
                CHECK_VM_STACK_OVERFLOW(th->ec.cfp, min_argc);
                given_argc = min_argc;
                args_extend(args, min_argc);
            }
            else {
                argument_arity_error(th, iseq, given_argc, min_argc, max_argc);
            }
        }
    }

    if (given_argc > min_argc &&
        (iseq->body->param.flags.has_kw || iseq->body->param.flags.has_kwrest ||
         (!iseq->body->param.flags.has_rest && given_argc > max_argc &&
          (ci->flag & VM_CALL_KW_SPLAT))) &&
        args->kw_argv == NULL) {
        if (args_pop_keyword_hash(args, &keyword_hash, th)) {
            given_argc--;
        }
    }

    if (given_argc > max_argc && max_argc != UNLIMITED_ARGUMENTS) {
        if (arg_setup_type == arg_setup_block) {
            /* truncate */
            args_reduce(args, given_argc - max_argc);
            given_argc = max_argc;
        }
        else {
            argument_arity_error(th, iseq, given_argc, min_argc, max_argc);
        }
    }

    if (iseq->body->param.flags.has_lead) {
        args_setup_lead_parameters(args, iseq->body->param.lead_num, locals + 0);
    }

    if (iseq->body->param.flags.has_post) {
        args_setup_post_parameters(args, iseq->body->param.post_num, locals + iseq->body->param.post_start);
    }

    if (iseq->body->param.flags.has_opt) {
        int opt = args_setup_opt_parameters(args, iseq->body->param.opt_num, locals + iseq->body->param.lead_num);
        opt_pc = (int)iseq->body->param.opt_table[opt];
    }

    if (iseq->body->param.flags.has_rest) {
        args_setup_rest_parameter(args, locals + iseq->body->param.rest_start);
    }

    if (iseq->body->param.flags.has_kw) {
        VALUE * const klocals = locals + iseq->body->param.keyword->bits_start - iseq->body->param.keyword->num;

        if (args->kw_argv != NULL) {
            const struct rb_call_info_kw_arg *kw_arg = args->kw_arg;
            args_setup_kw_parameters(args->kw_argv, kw_arg->keyword_len, kw_arg->keywords, iseq, klocals);
        }
        else if (!NIL_P(keyword_hash)) {
            int kw_len = rb_long2int(RHASH_SIZE(keyword_hash));
            struct fill_values_arg arg;
            /* copy kw_argv */
            arg.keys = args->kw_argv = ALLOCA_N(VALUE, kw_len * 2);
            arg.vals = arg.keys + kw_len;
            arg.argc = 0;
            rb_hash_foreach(keyword_hash, fill_keys_values, (VALUE)&arg);
            VM_ASSERT(arg.argc == kw_len);
            args_setup_kw_parameters(arg.vals, kw_len, arg.keys, iseq, klocals);
        }
        else {
            VM_ASSERT(args_argc(args) == 0);
            args_setup_kw_parameters(NULL, 0, NULL, iseq, klocals);
        }
    }
    else if (iseq->body->param.flags.has_kwrest) {
        args_setup_kw_rest_parameter(keyword_hash, locals + iseq->body->param.keyword->rest_start);
    }
    else if (!NIL_P(keyword_hash) && RHASH_SIZE(keyword_hash) > 0) {
        argument_kw_error(th, iseq, "unknown", rb_hash_keys(keyword_hash));
    }

    if (iseq->body->param.flags.has_block) {
        args_setup_block_parameter(th, calling, locals + iseq->body->param.block_start);
    }

#if 0
    {
        int i;
        for (i=0; i<iseq->body->param.size; i++) {
            fprintf(stderr, "local[%d] = %p\n", i, (void *)locals[i]);
        }
    }
#endif

    th->ec.cfp->sp = orig_sp;
    return opt_pc;
}

static void
raise_argument_error(rb_thread_t *th, const rb_iseq_t *iseq, const VALUE exc)
{
    VALUE at;

    if (iseq) {
        vm_push_frame(th, iseq, VM_FRAME_MAGIC_DUMMY | VM_ENV_FLAG_LOCAL, Qnil /* self */,
                      VM_BLOCK_HANDLER_NONE /* specval*/, Qfalse /* me or cref */,
                      iseq->body->iseq_encoded,
                      th->ec.cfp->sp, 0, 0 /* stack_max */);
        at = rb_threadptr_backtrace_object(th);
        rb_vm_pop_frame(th);
    }
    else {
        at = rb_threadptr_backtrace_object(th);
    }

    rb_ivar_set(exc, idBt_locations, at);
    rb_exc_set_backtrace(exc, at);
    rb_exc_raise(exc);
}

static void
argument_arity_error(rb_thread_t *th, const rb_iseq_t *iseq, const int miss_argc, const int min_argc, const int max_argc)
{
    VALUE exc = rb_arity_error_new(miss_argc, min_argc, max_argc);
    if (iseq->body->param.flags.has_kw) {
        const struct rb_iseq_param_keyword *const kw = iseq->body->param.keyword;
        const ID *keywords = kw->table;
        int req_key_num = kw->required_num;
        if (req_key_num > 0) {
            static const char required[] = "; required keywords";
            VALUE mesg = rb_attr_get(exc, idMesg);
            rb_str_resize(mesg, RSTRING_LEN(mesg)-1);
            rb_str_cat(mesg, required, sizeof(required) - 1 - (req_key_num == 1));
            rb_str_cat_cstr(mesg, ":");
            do {
                rb_str_cat_cstr(mesg, " ");
                rb_str_append(mesg, rb_id2str(*keywords++));
                rb_str_cat_cstr(mesg, ",");
            } while (--req_key_num);
            RSTRING_PTR(mesg)[RSTRING_LEN(mesg)-1] = ')';
        }
    }
    raise_argument_error(th, iseq, exc);
}

static void
argument_kw_error(rb_thread_t *th, const rb_iseq_t *iseq, const char *error, const VALUE keys)
{
    raise_argument_error(th, iseq, rb_keyword_error_new(error, keys));
}

static inline void
vm_caller_setup_arg_splat(rb_control_frame_t *cfp, struct rb_calling_info *calling)
{
    int argc = calling->argc;
    VALUE *argv = cfp->sp - argc;
    VALUE ary = argv[argc-1];

    cfp->sp--;

    if (!NIL_P(ary)) {
        const VALUE *ptr = RARRAY_CONST_PTR(ary);
        long len = RARRAY_LEN(ary), i;

        CHECK_VM_STACK_OVERFLOW(cfp, len);

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

static inline void
vm_caller_setup_arg_kw(rb_control_frame_t *cfp, struct rb_calling_info *calling, const struct rb_call_info *ci)
{
    struct rb_call_info_with_kwarg *ci_kw = (struct rb_call_info_with_kwarg *)ci;
    const VALUE *const passed_keywords = ci_kw->kw_arg->keywords;
    const int kw_len = ci_kw->kw_arg->keyword_len;
    const VALUE h = rb_hash_new_with_size(kw_len);
    VALUE *sp = cfp->sp;
    int i;

    for (i=0; i<kw_len; i++) {
        rb_hash_aset(h, passed_keywords[i], (sp - kw_len)[i]);
    }
    (sp-kw_len)[0] = h;

    cfp->sp -= kw_len - 1;
    calling->argc -= kw_len - 1;
}

static VALUE
vm_to_proc(VALUE proc)
{
    if (UNLIKELY(!rb_obj_is_proc(proc))) {
        VALUE b;
        b = rb_check_convert_type_with_id(proc, T_DATA, "Proc", idTo_proc);

        if (NIL_P(b) || !rb_obj_is_proc(b)) {
            rb_raise(rb_eTypeError,
                     "wrong argument type %s (expected Proc)",
                     rb_obj_classname(proc));
        }
        return b;
    }
    else {
        return proc;
    }
}

static VALUE
refine_sym_proc_call(RB_BLOCK_CALL_FUNC_ARGLIST(yielded_arg, callback_arg))
{
    VALUE obj;
    ID mid;
    const rb_callable_method_entry_t *me;
    rb_thread_t *th;

    if (argc-- < 1) {
        rb_raise(rb_eArgError, "no receiver given");
    }
    obj = *argv++;
    mid = SYM2ID(callback_arg);
    me = rb_callable_method_entry_with_refinements(CLASS_OF(obj), mid, NULL);
    th = GET_THREAD();
    if (!NIL_P(blockarg)) {
        vm_passed_block_handler_set(th, blockarg);
    }
    if (!me) {
        return method_missing(obj, mid, argc, argv, MISSING_NOENTRY);
    }
    return vm_call0(th, obj, mid, argc, argv, me);
}

static void
vm_caller_setup_arg_block(const rb_thread_t *th, rb_control_frame_t *reg_cfp,
                          struct rb_calling_info *calling, const struct rb_call_info *ci, rb_iseq_t *blockiseq, const int is_super)
{
    if (ci->flag & VM_CALL_ARGS_BLOCKARG) {
        VALUE block_code = *(--reg_cfp->sp);

        if (NIL_P(block_code)) {
            calling->block_handler = VM_BLOCK_HANDLER_NONE;
        }
        else {
            if (SYMBOL_P(block_code) && rb_method_basic_definition_p(rb_cSymbol, idTo_proc)) {
                const rb_cref_t *cref = vm_env_cref(reg_cfp->ep);
                if (cref && !NIL_P(cref->refinements)) {
                    VALUE ref = cref->refinements;
                    VALUE func = rb_hash_lookup(ref, block_code);
                    if (NIL_P(func)) {
                        /* TODO: limit cached funcs */
                        func = rb_func_proc_new(refine_sym_proc_call, block_code);
                        rb_hash_aset(ref, block_code, func);
                    }
                    block_code = func;
                }
                calling->block_handler = block_code;
            }
            else {
                calling->block_handler = vm_to_proc(block_code);
            }
        }
    }
    else if (blockiseq != NULL) { /* likely */
        struct rb_captured_block *captured = VM_CFP_TO_CAPTURED_BLOCK(reg_cfp);
        captured->code.iseq = blockiseq;
        calling->block_handler = VM_BH_FROM_ISEQ_BLOCK(captured);
    }
    else {
        if (is_super) {
            calling->block_handler = GET_BLOCK_HANDLER();
        }
        else {
            calling->block_handler = VM_BLOCK_HANDLER_NONE;
        }
    }
}

#define IS_ARGS_SPLAT(ci)   ((ci)->flag & VM_CALL_ARGS_SPLAT)
#define IS_ARGS_KEYWORD(ci) ((ci)->flag & VM_CALL_KWARG)

#define CALLER_SETUP_ARG(cfp, calling, ci) do { \
    if (UNLIKELY(IS_ARGS_SPLAT(ci))) vm_caller_setup_arg_splat((cfp), (calling)); \
    if (UNLIKELY(IS_ARGS_KEYWORD(ci))) vm_caller_setup_arg_kw((cfp), (calling), (ci)); \
} while (0)