py/objfun.c - lite/micropython - Linaro Git Browser

 /*
  * This file is part of the Micro Python project, http://micropython.org/
  *
  * The MIT License (MIT)
  *
  * Copyright (c) 2013, 2014 Damien P. George
  * Copyright (c) 2014 Paul Sokolovsky
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
  * in the Software without restriction, including without limitation the rights
  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  * copies of the Software, and to permit persons to whom the Software is
  * furnished to do so, subject to the following conditions:
  *
  * The above copyright notice and this permission notice shall be included in
  * all copies or substantial portions of the Software.
  *
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */

 #include <stdbool.h>
 #include <string.h>
 #include <assert.h>

 #include "mpconfig.h"
 #include "nlr.h"
 #include "misc.h"
 #include "qstr.h"
 #include "obj.h"
 #include "objtuple.h"
 #include "objfun.h"
 #include "runtime0.h"
 #include "runtime.h"
 #include "bc.h"
 #include "stackctrl.h"

 #if 0 // print debugging info
 #define DEBUG_PRINT (1)
 #else // don't print debugging info
 #define DEBUG_printf(...) (void)0
 #endif

 /******************************************************************************/
 /* native functions                                                           */

 // mp_obj_fun_native_t defined in obj.h

 STATIC mp_obj_t fun_binary_op(int op, mp_obj_t lhs_in, mp_obj_t rhs_in) {
     switch (op) {
         case MP_BINARY_OP_EQUAL:
             // These objects can be equal only if it's the same underlying structure,
             // we don't even need to check for 2nd arg type.
             return MP_BOOL(lhs_in == rhs_in);
     }
     return MP_OBJ_NULL; // op not supported
 }

 STATIC mp_obj_t fun_native_call(mp_obj_t self_in, uint n_args, uint n_kw, const mp_obj_t *args) {
     assert(MP_OBJ_IS_TYPE(self_in, &mp_type_fun_native));
     mp_obj_fun_native_t *self = self_in;

     // check number of arguments
     mp_arg_check_num(n_args, n_kw, self->n_args_min, self->n_args_max, self->is_kw);

     if (self->is_kw) {
         // function allows keywords

         // we create a map directly from the given args array
         mp_map_t kw_args;
         mp_map_init_fixed_table(&kw_args, n_kw, args + n_args);

         return ((mp_fun_kw_t)self->fun)(n_args, args, &kw_args);

     } else if (self->n_args_min <= 3 && self->n_args_min == self->n_args_max) {
         // function requires a fixed number of arguments

         // dispatch function call
         switch (self->n_args_min) {
             case 0:
                 return ((mp_fun_0_t)self->fun)();

             case 1:
                 return ((mp_fun_1_t)self->fun)(args[0]);

             case 2:
                 return ((mp_fun_2_t)self->fun)(args[0], args[1]);

             case 3:
                 return ((mp_fun_3_t)self->fun)(args[0], args[1], args[2]);

             default:
                 assert(0);
                 return mp_const_none;
         }

     } else {
         // function takes a variable number of arguments, but no keywords

         return ((mp_fun_var_t)self->fun)(n_args, args);
     }
 }

 const mp_obj_type_t mp_type_fun_native = {
     { &mp_type_type },
     .name = MP_QSTR_function,
     .call = fun_native_call,
     .binary_op = fun_binary_op,
 };

 // fun must have the correct signature for n_args fixed arguments
 mp_obj_t mp_make_function_n(int n_args, void *fun) {
     mp_obj_fun_native_t *o = m_new_obj(mp_obj_fun_native_t);
     o->base.type = &mp_type_fun_native;
     o->is_kw = false;
     o->n_args_min = n_args;
     o->n_args_max = n_args;
     o->fun = fun;
     return o;
 }

 mp_obj_t mp_make_function_var(int n_args_min, mp_fun_var_t fun) {
     mp_obj_fun_native_t *o = m_new_obj(mp_obj_fun_native_t);
     o->base.type = &mp_type_fun_native;
     o->is_kw = false;
     o->n_args_min = n_args_min;
     o->n_args_max = MP_OBJ_FUN_ARGS_MAX;
     o->fun = fun;
     return o;
 }

 // min and max are inclusive
 mp_obj_t mp_make_function_var_between(int n_args_min, int n_args_max, mp_fun_var_t fun) {
     mp_obj_fun_native_t *o = m_new_obj(mp_obj_fun_native_t);
     o->base.type = &mp_type_fun_native;
     o->is_kw = false;
     o->n_args_min = n_args_min;
     o->n_args_max = n_args_max;
     o->fun = fun;
     return o;
 }

 /******************************************************************************/
 /* byte code functions                                                        */

 const char *mp_obj_code_get_name(const byte *code_info) {
     qstr block_name = code_info[8] | (code_info[9] << 8) | (code_info[10] << 16) | (code_info[11] << 24);
     return qstr_str(block_name);
 }

 const char *mp_obj_fun_get_name(mp_const_obj_t fun_in) {
     const mp_obj_fun_bc_t *fun = fun_in;
     const byte *code_info = fun->bytecode;
     return mp_obj_code_get_name(code_info);
 }

 #if MICROPY_CPYTHON_COMPAT
 STATIC void fun_bc_print(void (*print)(void *env, const char *fmt, ...), void *env, mp_obj_t o_in, mp_print_kind_t kind) {
     mp_obj_fun_bc_t *o = o_in;
     print(env, "<function %s at 0x%x>", mp_obj_fun_get_name(o), o);
 }
 #endif

 #if DEBUG_PRINT
 STATIC void dump_args(const mp_obj_t *a, int sz) {
     DEBUG_printf("%p: ", a);
     for (int i = 0; i < sz; i++) {
         DEBUG_printf("%p ", a[i]);
     }
     DEBUG_printf("\n");
 }
 #else
 #define dump_args(...) (void)0
 #endif

 STATIC NORETURN void fun_pos_args_mismatch(mp_obj_fun_bc_t *f, uint expected, uint given) {
 #if MICROPY_ERROR_REPORTING == MICROPY_ERROR_REPORTING_TERSE
     // Generic message, to be reused for other argument issues
     nlr_raise(mp_obj_new_exception_msg(&mp_type_TypeError,
         "argument num/types mismatch"));
 #elif MICROPY_ERROR_REPORTING == MICROPY_ERROR_REPORTING_NORMAL
     nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_TypeError,
         "function takes %d positional arguments but %d were given", expected, given));
 #elif MICROPY_ERROR_REPORTING == MICROPY_ERROR_REPORTING_DETAILED
     nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_TypeError,
         "%s() takes %d positional arguments but %d were given",
         mp_obj_fun_get_name(f), expected, given));
 #endif
 }

 // With this macro you can tune the maximum number of function state bytes
 // that will be allocated on the stack.  Any function that needs more
 // than this will use the heap.
 #define VM_MAX_STATE_ON_STACK (10 * sizeof(mp_uint_t))

 // Set this to enable a simple stack overflow check.
 #define VM_DETECT_STACK_OVERFLOW (0)

 // code_state should have ->ip filled in (pointing past code info block),
 // as well as ->n_state.
 void mp_setup_code_state(mp_code_state *code_state, mp_obj_t self_in, uint n_args, uint n_kw, const mp_obj_t *args) {
     // This function is pretty complicated.  It's main aim is to be efficient in speed and RAM
     // usage for the common case of positional only args.
     mp_obj_fun_bc_t *self = self_in;
     mp_uint_t n_state = code_state->n_state;
     const byte *ip = code_state->ip;

     code_state->code_info = self->bytecode;
     code_state->sp = &code_state->state[0] - 1;
     code_state->exc_sp = (mp_exc_stack_t*)(code_state->state + n_state) - 1;

     // zero out the local stack to begin with
     memset(code_state->state, 0, n_state * sizeof(*code_state->state));

     const mp_obj_t *kwargs = args + n_args;

     // var_pos_kw_args points to the stack where the var-args tuple, and var-kw dict, should go (if they are needed)
     mp_obj_t *var_pos_kw_args = &code_state->state[n_state - 1 - self->n_pos_args - self->n_kwonly_args];

     // check positional arguments

     if (n_args > self->n_pos_args) {
         // given more than enough arguments
         if (!self->takes_var_args) {
             fun_pos_args_mismatch(self, self->n_pos_args, n_args);
         }
         // put extra arguments in varargs tuple
         *var_pos_kw_args-- = mp_obj_new_tuple(n_args - self->n_pos_args, args + self->n_pos_args);
         n_args = self->n_pos_args;
     } else {
         if (self->takes_var_args) {
             DEBUG_printf("passing empty tuple as *args\n");
             *var_pos_kw_args-- = mp_const_empty_tuple;
         }
         // Apply processing and check below only if we don't have kwargs,
         // otherwise, kw handling code below has own extensive checks.
         if (n_kw == 0 && !self->has_def_kw_args) {
             if (n_args >= self->n_pos_args - self->n_def_args) {
                 // given enough arguments, but may need to use some default arguments
                 for (uint i = n_args; i < self->n_pos_args; i++) {
                     code_state->state[n_state - 1 - i] = self->extra_args[i - (self->n_pos_args - self->n_def_args)];
                 }
             } else {
                 fun_pos_args_mismatch(self, self->n_pos_args - self->n_def_args, n_args);
             }
         }
     }

     // copy positional args into state
     for (uint i = 0; i < n_args; i++) {
         code_state->state[n_state - 1 - i] = args[i];
     }

     // check keyword arguments

     if (n_kw != 0 || self->has_def_kw_args) {
         DEBUG_printf("Initial args: ");
         dump_args(code_state->state + n_state - self->n_pos_args - self->n_kwonly_args, self->n_pos_args + self->n_kwonly_args);

         mp_obj_t dict = MP_OBJ_NULL;
         if (self->takes_kw_args) {
             dict = mp_obj_new_dict(n_kw); // TODO: better go conservative with 0?
             *var_pos_kw_args = dict;
         }

         for (uint i = 0; i < n_kw; i++) {
             qstr arg_name = MP_OBJ_QSTR_VALUE(kwargs[2 * i]);
             for (uint j = 0; j < self->n_pos_args + self->n_kwonly_args; j++) {
                 if (arg_name == self->args[j]) {
                     if (code_state->state[n_state - 1 - j] != MP_OBJ_NULL) {
                         nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_TypeError,
                             "function got multiple values for argument '%s'", qstr_str(arg_name)));
                     }
                     code_state->state[n_state - 1 - j] = kwargs[2 * i + 1];
                     goto continue2;
                 }
             }
             // Didn't find name match with positional args
             if (!self->takes_kw_args) {
                 nlr_raise(mp_obj_new_exception_msg(&mp_type_TypeError, "function does not take keyword arguments"));
             }
             mp_obj_dict_store(dict, kwargs[2 * i], kwargs[2 * i + 1]);
 continue2:;
         }

         DEBUG_printf("Args with kws flattened: ");
         dump_args(code_state->state + n_state - self->n_pos_args - self->n_kwonly_args, self->n_pos_args + self->n_kwonly_args);

         // fill in defaults for positional args
         mp_obj_t *d = &code_state->state[n_state - self->n_pos_args];
         mp_obj_t *s = &self->extra_args[self->n_def_args - 1];
         for (int i = self->n_def_args; i > 0; i--, d++, s--) {
             if (*d == MP_OBJ_NULL) {
                 *d = *s;
             }
         }

         DEBUG_printf("Args after filling default positional: ");
         dump_args(code_state->state + n_state - self->n_pos_args - self->n_kwonly_args, self->n_pos_args + self->n_kwonly_args);

         // Check that all mandatory positional args are specified
         while (d < &code_state->state[n_state]) {
             if (*d++ == MP_OBJ_NULL) {
                 nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_TypeError,
                     "function missing required positional argument #%d", &code_state->state[n_state] - d));
             }
         }

         // Check that all mandatory keyword args are specified
         // Fill in default kw args if we have them
         for (uint i = 0; i < self->n_kwonly_args; i++) {
             if (code_state->state[n_state - 1 - self->n_pos_args - i] == MP_OBJ_NULL) {
                 mp_map_elem_t *elem = NULL;
                 if (self->has_def_kw_args) {
                     elem = mp_map_lookup(&((mp_obj_dict_t*)self->extra_args[self->n_def_args])->map, MP_OBJ_NEW_QSTR(self->args[self->n_pos_args + i]), MP_MAP_LOOKUP);
                 }
                 if (elem != NULL) {
                     code_state->state[n_state - 1 - self->n_pos_args - i] = elem->value;
                 } else {
                     nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_TypeError,
                         "function missing required keyword argument '%s'", qstr_str(self->args[self->n_pos_args + i])));
                 }
             }
         }

     } else {
         // no keyword arguments given
         if (self->n_kwonly_args != 0) {
             nlr_raise(mp_obj_new_exception_msg(&mp_type_TypeError,
                 "function missing keyword-only argument"));
         }
         if (self->takes_kw_args) {
             *var_pos_kw_args = mp_obj_new_dict(0);
         }
     }

     // bytecode prelude: initialise closed over variables
     for (uint n_local = *ip++; n_local > 0; n_local--) {
         uint local_num = *ip++;
         code_state->state[n_state - 1 - local_num] = mp_obj_new_cell(code_state->state[n_state - 1 - local_num]);
     }

     // now that we skipped over the prelude, set the ip for the VM
     code_state->ip = ip;

     DEBUG_printf("Calling: n_pos_args=%d, n_kwonly_args=%d\n", self->n_pos_args, self->n_kwonly_args);
     dump_args(code_state->state + n_state - self->n_pos_args - self->n_kwonly_args, self->n_pos_args + self->n_kwonly_args);
     dump_args(code_state->state, n_state);
 }


 STATIC mp_obj_t fun_bc_call(mp_obj_t self_in, uint n_args, uint n_kw, const mp_obj_t *args) {
     MP_STACK_CHECK();

     DEBUG_printf("Input n_args: %d, n_kw: %d\n", n_args, n_kw);
     DEBUG_printf("Input pos args: ");
     dump_args(args, n_args);
     DEBUG_printf("Input kw args: ");
     dump_args(args + n_args, n_kw * 2);
     mp_obj_fun_bc_t *self = self_in;
     DEBUG_printf("Func n_def_args: %d\n", self->n_def_args);

     const byte *ip = self->bytecode;

     // get code info size, and skip line number table
     mp_uint_t code_info_size = ip[0] | (ip[1] << 8) | (ip[2] << 16) | (ip[3] << 24);
     ip += code_info_size;

     // bytecode prelude: state size and exception stack size; 16 bit uints
     mp_uint_t n_state = ip[0] | (ip[1] << 8);
     mp_uint_t n_exc_stack = ip[2] | (ip[3] << 8);
     ip += 4;

 #if VM_DETECT_STACK_OVERFLOW
     n_state += 1;
 #endif

     // allocate state for locals and stack
     uint state_size = n_state * sizeof(mp_obj_t) + n_exc_stack * sizeof(mp_exc_stack_t);
     mp_code_state *code_state;
     if (state_size > VM_MAX_STATE_ON_STACK) {
         code_state = m_new_obj_var(mp_code_state, byte, state_size);
     } else {
         code_state = alloca(sizeof(mp_code_state) + state_size);
     }

     code_state->n_state = n_state;
     code_state->ip = ip;
     mp_setup_code_state(code_state, self_in, n_args, n_kw, args);

     // execute the byte code with the correct globals context
     mp_obj_dict_t *old_globals = mp_globals_get();
     mp_globals_set(self->globals);
     mp_vm_return_kind_t vm_return_kind = mp_execute_bytecode(code_state, MP_OBJ_NULL);
     mp_globals_set(old_globals);

 #if VM_DETECT_STACK_OVERFLOW
     if (vm_return_kind == MP_VM_RETURN_NORMAL) {
         if (code_state->sp < code_state->state) {
             printf("VM stack underflow: " INT_FMT "\n", code_state->sp - code_state->state);
             assert(0);
         }
     }
     // We can't check the case when an exception is returned in state[n_state - 1]
     // and there are no arguments, because in this case our detection slot may have
     // been overwritten by the returned exception (which is allowed).
     if (!(vm_return_kind == MP_VM_RETURN_EXCEPTION && self->n_pos_args + self->n_kwonly_args == 0)) {
         // Just check to see that we have at least 1 null object left in the state.
         bool overflow = true;
         for (uint i = 0; i < n_state - self->n_pos_args - self->n_kwonly_args; i++) {
             if (code_state->state[i] == MP_OBJ_NULL) {
                 overflow = false;
                 break;
             }
         }
         if (overflow) {
             printf("VM stack overflow state=%p n_state+1=" UINT_FMT "\n", code_state->state, n_state);
             assert(0);
         }
     }
 #endif

     mp_obj_t result;
     switch (vm_return_kind) {
         case MP_VM_RETURN_NORMAL:
             // return value is in *sp
             result = *code_state->sp;
             break;

         case MP_VM_RETURN_EXCEPTION:
             // return value is in state[n_state - 1]
             result = code_state->state[n_state - 1];
             break;

         case MP_VM_RETURN_YIELD: // byte-code shouldn't yield
         default:
             assert(0);
             result = mp_const_none;
             vm_return_kind = MP_VM_RETURN_NORMAL;
             break;
     }

     // free the state if it was allocated on the heap
     if (state_size > VM_MAX_STATE_ON_STACK) {
         m_del_var(mp_code_state, byte, state_size, code_state);
     }

     if (vm_return_kind == MP_VM_RETURN_NORMAL) {
         return result;
     } else { // MP_VM_RETURN_EXCEPTION
         nlr_raise(result);
     }
 }

 const mp_obj_type_t mp_type_fun_bc = {
     { &mp_type_type },
     .name = MP_QSTR_function,
 #if MICROPY_CPYTHON_COMPAT
     .print = fun_bc_print,
 #endif
     .call = fun_bc_call,
     .binary_op = fun_binary_op,
 };

 mp_obj_t mp_obj_new_fun_bc(uint scope_flags, qstr *args, uint n_pos_args, uint n_kwonly_args, mp_obj_t def_args_in, mp_obj_t def_kw_args, const byte *code) {
     uint n_def_args = 0;
     uint n_extra_args = 0;
     mp_obj_tuple_t *def_args = def_args_in;
     if (def_args != MP_OBJ_NULL) {
         assert(MP_OBJ_IS_TYPE(def_args, &mp_type_tuple));
         n_def_args = def_args->len;
         n_extra_args = def_args->len;
     }
     if (def_kw_args != MP_OBJ_NULL) {
         n_extra_args += 1;
     }
     mp_obj_fun_bc_t *o = m_new_obj_var(mp_obj_fun_bc_t, mp_obj_t, n_extra_args);
     o->base.type = &mp_type_fun_bc;
     o->globals = mp_globals_get();
     o->args = args;
     o->n_pos_args = n_pos_args;
     o->n_kwonly_args = n_kwonly_args;
     o->n_def_args = n_def_args;
     o->has_def_kw_args = def_kw_args != MP_OBJ_NULL;
     o->takes_var_args = (scope_flags & MP_SCOPE_FLAG_VARARGS) != 0;
     o->takes_kw_args = (scope_flags & MP_SCOPE_FLAG_VARKEYWORDS) != 0;
     o->bytecode = code;
     if (def_args != MP_OBJ_NULL) {
         memcpy(o->extra_args, def_args->items, n_def_args * sizeof(mp_obj_t));
     }
     if (def_kw_args != MP_OBJ_NULL) {
         o->extra_args[n_def_args] = def_kw_args;
     }
     return o;
 }

 /******************************************************************************/
 /* inline assembler functions                                                 */

 typedef struct _mp_obj_fun_asm_t {
     mp_obj_base_t base;
     int n_args;
     void *fun;
 } mp_obj_fun_asm_t;

 typedef mp_uint_t (*inline_asm_fun_0_t)();
 typedef mp_uint_t (*inline_asm_fun_1_t)(mp_uint_t);
 typedef mp_uint_t (*inline_asm_fun_2_t)(mp_uint_t, mp_uint_t);
 typedef mp_uint_t (*inline_asm_fun_3_t)(mp_uint_t, mp_uint_t, mp_uint_t);

 // convert a Micro Python object to a sensible value for inline asm
 STATIC mp_uint_t convert_obj_for_inline_asm(mp_obj_t obj) {
     // TODO for byte_array, pass pointer to the array
     if (MP_OBJ_IS_SMALL_INT(obj)) {
         return MP_OBJ_SMALL_INT_VALUE(obj);
     } else if (obj == mp_const_none) {
         return 0;
     } else if (obj == mp_const_false) {
         return 0;
     } else if (obj == mp_const_true) {
         return 1;
     } else if (MP_OBJ_IS_STR(obj)) {
         // pointer to the string (it's probably constant though!)
         uint l;
         return (mp_uint_t)mp_obj_str_get_data(obj, &l);
     } else {
         mp_obj_type_t *type = mp_obj_get_type(obj);
         if (0) {
 #if MICROPY_PY_BUILTINS_FLOAT
         } else if (type == &mp_type_float) {
             // convert float to int (could also pass in float registers)
             return (mp_int_t)mp_obj_float_get(obj);
 #endif
         } else if (type == &mp_type_tuple) {
             // pointer to start of tuple (could pass length, but then could use len(x) for that)
             uint len;
             mp_obj_t *items;
             mp_obj_tuple_get(obj, &len, &items);
             return (mp_uint_t)items;
         } else if (type == &mp_type_list) {
             // pointer to start of list (could pass length, but then could use len(x) for that)
             uint len;
             mp_obj_t *items;
             mp_obj_list_get(obj, &len, &items);
             return (mp_uint_t)items;
         } else {
             mp_buffer_info_t bufinfo;
             if (mp_get_buffer(obj, &bufinfo, MP_BUFFER_WRITE)) {
                 // supports the buffer protocol, return a pointer to the data
                 return (mp_uint_t)bufinfo.buf;
             } else {
                 // just pass along a pointer to the object
                 return (mp_uint_t)obj;
             }
         }
     }
 }

 // convert a return value from inline asm to a sensible Micro Python object
 STATIC mp_obj_t convert_val_from_inline_asm(mp_uint_t val) {
     return MP_OBJ_NEW_SMALL_INT(val);
 }

 STATIC mp_obj_t fun_asm_call(mp_obj_t self_in, uint n_args, uint n_kw, const mp_obj_t *args) {
     mp_obj_fun_asm_t *self = self_in;

     mp_arg_check_num(n_args, n_kw, self->n_args, self->n_args, false);

     mp_uint_t ret;
     if (n_args == 0) {
         ret = ((inline_asm_fun_0_t)self->fun)();
     } else if (n_args == 1) {
         ret = ((inline_asm_fun_1_t)self->fun)(convert_obj_for_inline_asm(args[0]));
     } else if (n_args == 2) {
         ret = ((inline_asm_fun_2_t)self->fun)(convert_obj_for_inline_asm(args[0]), convert_obj_for_inline_asm(args[1]));
     } else if (n_args == 3) {
         ret = ((inline_asm_fun_3_t)self->fun)(convert_obj_for_inline_asm(args[0]), convert_obj_for_inline_asm(args[1]), convert_obj_for_inline_asm(args[2]));
     } else {
         assert(0);
         ret = 0;
     }

     return convert_val_from_inline_asm(ret);
 }

 STATIC const mp_obj_type_t mp_type_fun_asm = {
     { &mp_type_type },
     .name = MP_QSTR_function,
     .call = fun_asm_call,
     .binary_op = fun_binary_op,
 };

 mp_obj_t mp_obj_new_fun_asm(uint n_args, void *fun) {
     mp_obj_fun_asm_t *o = m_new_obj(mp_obj_fun_asm_t);
     o->base.type = &mp_type_fun_asm;
     o->n_args = n_args;
     o->fun = fun;
     return o;
 }
	/*
	* This file is part of the Micro Python project, http://micropython.org/
	*
	* The MIT License (MIT)
	*
	* Copyright (c) 2013, 2014 Damien P. George
	* Copyright (c) 2014 Paul Sokolovsky
	*
	* Permission is hereby granted, free of charge, to any person obtaining a copy
	* of this software and associated documentation files (the "Software"), to deal
	* in the Software without restriction, including without limitation the rights
	* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
	* copies of the Software, and to permit persons to whom the Software is
	* furnished to do so, subject to the following conditions:
	*
	* The above copyright notice and this permission notice shall be included in
	* all copies or substantial portions of the Software.
	*
	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
	* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
	* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
	* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
	* THE SOFTWARE.
	*/

	#include <stdbool.h>
	#include <string.h>
	#include <assert.h>

	#include "mpconfig.h"
	#include "nlr.h"
	#include "misc.h"
	#include "qstr.h"
	#include "obj.h"
	#include "objtuple.h"
	#include "objfun.h"
	#include "runtime0.h"
	#include "runtime.h"
	#include "bc.h"
	#include "stackctrl.h"

	#if 0 // print debugging info
	#define DEBUG_PRINT (1)
	#else // don't print debugging info
	#define DEBUG_printf(...) (void)0
	#endif

	/******************************************************************************/
	/* native functions */

	// mp_obj_fun_native_t defined in obj.h

	STATIC mp_obj_t fun_binary_op(int op, mp_obj_t lhs_in, mp_obj_t rhs_in) {
	switch (op) {
	case MP_BINARY_OP_EQUAL:
	// These objects can be equal only if it's the same underlying structure,
	// we don't even need to check for 2nd arg type.
	return MP_BOOL(lhs_in == rhs_in);
	}
	return MP_OBJ_NULL; // op not supported
	}

	STATIC mp_obj_t fun_native_call(mp_obj_t self_in, uint n_args, uint n_kw, const mp_obj_t *args) {
	assert(MP_OBJ_IS_TYPE(self_in, &mp_type_fun_native));
	mp_obj_fun_native_t *self = self_in;

	// check number of arguments
	mp_arg_check_num(n_args, n_kw, self->n_args_min, self->n_args_max, self->is_kw);

	if (self->is_kw) {
	// function allows keywords

	// we create a map directly from the given args array
	mp_map_t kw_args;
	mp_map_init_fixed_table(&kw_args, n_kw, args + n_args);

	return ((mp_fun_kw_t)self->fun)(n_args, args, &kw_args);

	} else if (self->n_args_min <= 3 && self->n_args_min == self->n_args_max) {
	// function requires a fixed number of arguments

	// dispatch function call
	switch (self->n_args_min) {
	case 0:
	return ((mp_fun_0_t)self->fun)();

	case 1:
	return ((mp_fun_1_t)self->fun)(args[0]);

	case 2:
	return ((mp_fun_2_t)self->fun)(args[0], args[1]);

	case 3:
	return ((mp_fun_3_t)self->fun)(args[0], args[1], args[2]);

	default:
	assert(0);
	return mp_const_none;
	}

	} else {
	// function takes a variable number of arguments, but no keywords

	return ((mp_fun_var_t)self->fun)(n_args, args);
	}
	}

	const mp_obj_type_t mp_type_fun_native = {
	{ &mp_type_type },
	.name = MP_QSTR_function,
	.call = fun_native_call,
	.binary_op = fun_binary_op,
	};

	// fun must have the correct signature for n_args fixed arguments
	mp_obj_t mp_make_function_n(int n_args, void *fun) {
	mp_obj_fun_native_t *o = m_new_obj(mp_obj_fun_native_t);
	o->base.type = &mp_type_fun_native;
	o->is_kw = false;
	o->n_args_min = n_args;
	o->n_args_max = n_args;
	o->fun = fun;
	return o;
	}

	mp_obj_t mp_make_function_var(int n_args_min, mp_fun_var_t fun) {
	mp_obj_fun_native_t *o = m_new_obj(mp_obj_fun_native_t);
	o->base.type = &mp_type_fun_native;
	o->is_kw = false;
	o->n_args_min = n_args_min;
	o->n_args_max = MP_OBJ_FUN_ARGS_MAX;
	o->fun = fun;
	return o;
	}

	// min and max are inclusive
	mp_obj_t mp_make_function_var_between(int n_args_min, int n_args_max, mp_fun_var_t fun) {
	mp_obj_fun_native_t *o = m_new_obj(mp_obj_fun_native_t);
	o->base.type = &mp_type_fun_native;
	o->is_kw = false;
	o->n_args_min = n_args_min;
	o->n_args_max = n_args_max;
	o->fun = fun;
	return o;
	}

	/******************************************************************************/
	/* byte code functions */

	const char mp_obj_code_get_name(const byte code_info) {
	qstr block_name = code_info[8] \| (code_info[9] << 8) \| (code_info[10] << 16) \| (code_info[11] << 24);
	return qstr_str(block_name);
	}

	const char *mp_obj_fun_get_name(mp_const_obj_t fun_in) {
	const mp_obj_fun_bc_t *fun = fun_in;
	const byte *code_info = fun->bytecode;
	return mp_obj_code_get_name(code_info);
	}

	#if MICROPY_CPYTHON_COMPAT
	STATIC void fun_bc_print(void (print)(void env, const char fmt, ...), void env, mp_obj_t o_in, mp_print_kind_t kind) {
	mp_obj_fun_bc_t *o = o_in;
	print(env, "<function %s at 0x%x>", mp_obj_fun_get_name(o), o);
	}
	#endif

	#if DEBUG_PRINT
	STATIC void dump_args(const mp_obj_t *a, int sz) {
	DEBUG_printf("%p: ", a);
	for (int i = 0; i < sz; i++) {
	DEBUG_printf("%p ", a[i]);
	}
	DEBUG_printf("\n");
	}
	#else
	#define dump_args(...) (void)0
	#endif

	STATIC NORETURN void fun_pos_args_mismatch(mp_obj_fun_bc_t *f, uint expected, uint given) {
	#if MICROPY_ERROR_REPORTING == MICROPY_ERROR_REPORTING_TERSE
	// Generic message, to be reused for other argument issues
	nlr_raise(mp_obj_new_exception_msg(&mp_type_TypeError,
	"argument num/types mismatch"));
	#elif MICROPY_ERROR_REPORTING == MICROPY_ERROR_REPORTING_NORMAL
	nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_TypeError,
	"function takes %d positional arguments but %d were given", expected, given));
	#elif MICROPY_ERROR_REPORTING == MICROPY_ERROR_REPORTING_DETAILED
	nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_TypeError,
	"%s() takes %d positional arguments but %d were given",
	mp_obj_fun_get_name(f), expected, given));
	#endif
	}

	// With this macro you can tune the maximum number of function state bytes
	// that will be allocated on the stack. Any function that needs more
	// than this will use the heap.
	#define VM_MAX_STATE_ON_STACK (10 * sizeof(mp_uint_t))

	// Set this to enable a simple stack overflow check.
	#define VM_DETECT_STACK_OVERFLOW (0)

	// code_state should have ->ip filled in (pointing past code info block),
	// as well as ->n_state.
	void mp_setup_code_state(mp_code_state code_state, mp_obj_t self_in, uint n_args, uint n_kw, const mp_obj_t args) {
	// This function is pretty complicated. It's main aim is to be efficient in speed and RAM
	// usage for the common case of positional only args.
	mp_obj_fun_bc_t *self = self_in;
	mp_uint_t n_state = code_state->n_state;
	const byte *ip = code_state->ip;

	code_state->code_info = self->bytecode;
	code_state->sp = &code_state->state[0] - 1;
	code_state->exc_sp = (mp_exc_stack_t*)(code_state->state + n_state) - 1;

	// zero out the local stack to begin with
	memset(code_state->state, 0, n_state * sizeof(*code_state->state));

	const mp_obj_t *kwargs = args + n_args;

	// var_pos_kw_args points to the stack where the var-args tuple, and var-kw dict, should go (if they are needed)
	mp_obj_t *var_pos_kw_args = &code_state->state[n_state - 1 - self->n_pos_args - self->n_kwonly_args];

	// check positional arguments

	if (n_args > self->n_pos_args) {
	// given more than enough arguments
	if (!self->takes_var_args) {
	fun_pos_args_mismatch(self, self->n_pos_args, n_args);
	}
	// put extra arguments in varargs tuple
	*var_pos_kw_args-- = mp_obj_new_tuple(n_args - self->n_pos_args, args + self->n_pos_args);
	n_args = self->n_pos_args;
	} else {
	if (self->takes_var_args) {
	DEBUG_printf("passing empty tuple as *args\n");
	*var_pos_kw_args-- = mp_const_empty_tuple;
	}
	// Apply processing and check below only if we don't have kwargs,
	// otherwise, kw handling code below has own extensive checks.
	if (n_kw == 0 && !self->has_def_kw_args) {
	if (n_args >= self->n_pos_args - self->n_def_args) {
	// given enough arguments, but may need to use some default arguments
	for (uint i = n_args; i < self->n_pos_args; i++) {
	code_state->state[n_state - 1 - i] = self->extra_args[i - (self->n_pos_args - self->n_def_args)];
	}
	} else {
	fun_pos_args_mismatch(self, self->n_pos_args - self->n_def_args, n_args);
	}
	}
	}

	// copy positional args into state
	for (uint i = 0; i < n_args; i++) {
	code_state->state[n_state - 1 - i] = args[i];
	}

	// check keyword arguments

	if (n_kw != 0 \|\| self->has_def_kw_args) {
	DEBUG_printf("Initial args: ");
	dump_args(code_state->state + n_state - self->n_pos_args - self->n_kwonly_args, self->n_pos_args + self->n_kwonly_args);

	mp_obj_t dict = MP_OBJ_NULL;
	if (self->takes_kw_args) {
	dict = mp_obj_new_dict(n_kw); // TODO: better go conservative with 0?
	*var_pos_kw_args = dict;
	}

	for (uint i = 0; i < n_kw; i++) {
	qstr arg_name = MP_OBJ_QSTR_VALUE(kwargs[2 * i]);
	for (uint j = 0; j < self->n_pos_args + self->n_kwonly_args; j++) {
	if (arg_name == self->args[j]) {
	if (code_state->state[n_state - 1 - j] != MP_OBJ_NULL) {
	nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_TypeError,
	"function got multiple values for argument '%s'", qstr_str(arg_name)));
	}
	code_state->state[n_state - 1 - j] = kwargs[2 * i + 1];
	goto continue2;
	}
	}
	// Didn't find name match with positional args
	if (!self->takes_kw_args) {
	nlr_raise(mp_obj_new_exception_msg(&mp_type_TypeError, "function does not take keyword arguments"));
	}
	mp_obj_dict_store(dict, kwargs[2 * i], kwargs[2 * i + 1]);
	continue2:;
	}

	DEBUG_printf("Args with kws flattened: ");
	dump_args(code_state->state + n_state - self->n_pos_args - self->n_kwonly_args, self->n_pos_args + self->n_kwonly_args);

	// fill in defaults for positional args
	mp_obj_t *d = &code_state->state[n_state - self->n_pos_args];
	mp_obj_t *s = &self->extra_args[self->n_def_args - 1];
	for (int i = self->n_def_args; i > 0; i--, d++, s--) {
	if (*d == MP_OBJ_NULL) {
	d = s;
	}
	}

	DEBUG_printf("Args after filling default positional: ");
	dump_args(code_state->state + n_state - self->n_pos_args - self->n_kwonly_args, self->n_pos_args + self->n_kwonly_args);

	// Check that all mandatory positional args are specified
	while (d < &code_state->state[n_state]) {
	if (*d++ == MP_OBJ_NULL) {
	nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_TypeError,
	"function missing required positional argument #%d", &code_state->state[n_state] - d));
	}
	}

	// Check that all mandatory keyword args are specified
	// Fill in default kw args if we have them
	for (uint i = 0; i < self->n_kwonly_args; i++) {
	if (code_state->state[n_state - 1 - self->n_pos_args - i] == MP_OBJ_NULL) {
	mp_map_elem_t *elem = NULL;
	if (self->has_def_kw_args) {
	elem = mp_map_lookup(&((mp_obj_dict_t*)self->extra_args[self->n_def_args])->map, MP_OBJ_NEW_QSTR(self->args[self->n_pos_args + i]), MP_MAP_LOOKUP);
	}
	if (elem != NULL) {
	code_state->state[n_state - 1 - self->n_pos_args - i] = elem->value;
	} else {
	nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_TypeError,
	"function missing required keyword argument '%s'", qstr_str(self->args[self->n_pos_args + i])));
	}
	}
	}

	} else {
	// no keyword arguments given
	if (self->n_kwonly_args != 0) {
	nlr_raise(mp_obj_new_exception_msg(&mp_type_TypeError,
	"function missing keyword-only argument"));
	}
	if (self->takes_kw_args) {
	*var_pos_kw_args = mp_obj_new_dict(0);
	}
	}

	// bytecode prelude: initialise closed over variables
	for (uint n_local = *ip++; n_local > 0; n_local--) {
	uint local_num = *ip++;
	code_state->state[n_state - 1 - local_num] = mp_obj_new_cell(code_state->state[n_state - 1 - local_num]);
	}

	// now that we skipped over the prelude, set the ip for the VM
	code_state->ip = ip;

	DEBUG_printf("Calling: n_pos_args=%d, n_kwonly_args=%d\n", self->n_pos_args, self->n_kwonly_args);
	dump_args(code_state->state + n_state - self->n_pos_args - self->n_kwonly_args, self->n_pos_args + self->n_kwonly_args);
	dump_args(code_state->state, n_state);
	}


	STATIC mp_obj_t fun_bc_call(mp_obj_t self_in, uint n_args, uint n_kw, const mp_obj_t *args) {
	MP_STACK_CHECK();

	DEBUG_printf("Input n_args: %d, n_kw: %d\n", n_args, n_kw);
	DEBUG_printf("Input pos args: ");
	dump_args(args, n_args);
	DEBUG_printf("Input kw args: ");
	dump_args(args + n_args, n_kw * 2);
	mp_obj_fun_bc_t *self = self_in;
	DEBUG_printf("Func n_def_args: %d\n", self->n_def_args);

	const byte *ip = self->bytecode;

	// get code info size, and skip line number table
	mp_uint_t code_info_size = ip[0] \| (ip[1] << 8) \| (ip[2] << 16) \| (ip[3] << 24);
	ip += code_info_size;

	// bytecode prelude: state size and exception stack size; 16 bit uints
	mp_uint_t n_state = ip[0] \| (ip[1] << 8);
	mp_uint_t n_exc_stack = ip[2] \| (ip[3] << 8);
	ip += 4;

	#if VM_DETECT_STACK_OVERFLOW
	n_state += 1;
	#endif

	// allocate state for locals and stack
	uint state_size = n_state * sizeof(mp_obj_t) + n_exc_stack * sizeof(mp_exc_stack_t);
	mp_code_state *code_state;
	if (state_size > VM_MAX_STATE_ON_STACK) {
	code_state = m_new_obj_var(mp_code_state, byte, state_size);
	} else {
	code_state = alloca(sizeof(mp_code_state) + state_size);
	}

	code_state->n_state = n_state;
	code_state->ip = ip;
	mp_setup_code_state(code_state, self_in, n_args, n_kw, args);

	// execute the byte code with the correct globals context
	mp_obj_dict_t *old_globals = mp_globals_get();
	mp_globals_set(self->globals);
	mp_vm_return_kind_t vm_return_kind = mp_execute_bytecode(code_state, MP_OBJ_NULL);
	mp_globals_set(old_globals);

	#if VM_DETECT_STACK_OVERFLOW
	if (vm_return_kind == MP_VM_RETURN_NORMAL) {
	if (code_state->sp < code_state->state) {
	printf("VM stack underflow: " INT_FMT "\n", code_state->sp - code_state->state);
	assert(0);
	}
	}
	// We can't check the case when an exception is returned in state[n_state - 1]
	// and there are no arguments, because in this case our detection slot may have
	// been overwritten by the returned exception (which is allowed).
	if (!(vm_return_kind == MP_VM_RETURN_EXCEPTION && self->n_pos_args + self->n_kwonly_args == 0)) {
	// Just check to see that we have at least 1 null object left in the state.
	bool overflow = true;
	for (uint i = 0; i < n_state - self->n_pos_args - self->n_kwonly_args; i++) {
	if (code_state->state[i] == MP_OBJ_NULL) {
	overflow = false;
	break;
	}
	}
	if (overflow) {
	printf("VM stack overflow state=%p n_state+1=" UINT_FMT "\n", code_state->state, n_state);
	assert(0);
	}
	}
	#endif

	mp_obj_t result;
	switch (vm_return_kind) {
	case MP_VM_RETURN_NORMAL:
	// return value is in *sp
	result = *code_state->sp;
	break;

	case MP_VM_RETURN_EXCEPTION:
	// return value is in state[n_state - 1]
	result = code_state->state[n_state - 1];
	break;

	case MP_VM_RETURN_YIELD: // byte-code shouldn't yield
	default:
	assert(0);
	result = mp_const_none;
	vm_return_kind = MP_VM_RETURN_NORMAL;
	break;
	}

	// free the state if it was allocated on the heap
	if (state_size > VM_MAX_STATE_ON_STACK) {
	m_del_var(mp_code_state, byte, state_size, code_state);
	}

	if (vm_return_kind == MP_VM_RETURN_NORMAL) {
	return result;
	} else { // MP_VM_RETURN_EXCEPTION
	nlr_raise(result);
	}
	}

	const mp_obj_type_t mp_type_fun_bc = {
	{ &mp_type_type },
	.name = MP_QSTR_function,
	#if MICROPY_CPYTHON_COMPAT
	.print = fun_bc_print,
	#endif
	.call = fun_bc_call,
	.binary_op = fun_binary_op,
	};

	mp_obj_t mp_obj_new_fun_bc(uint scope_flags, qstr args, uint n_pos_args, uint n_kwonly_args, mp_obj_t def_args_in, mp_obj_t def_kw_args, const byte code) {
	uint n_def_args = 0;
	uint n_extra_args = 0;
	mp_obj_tuple_t *def_args = def_args_in;
	if (def_args != MP_OBJ_NULL) {
	assert(MP_OBJ_IS_TYPE(def_args, &mp_type_tuple));
	n_def_args = def_args->len;
	n_extra_args = def_args->len;
	}
	if (def_kw_args != MP_OBJ_NULL) {
	n_extra_args += 1;
	}
	mp_obj_fun_bc_t *o = m_new_obj_var(mp_obj_fun_bc_t, mp_obj_t, n_extra_args);
	o->base.type = &mp_type_fun_bc;
	o->globals = mp_globals_get();
	o->args = args;
	o->n_pos_args = n_pos_args;
	o->n_kwonly_args = n_kwonly_args;
	o->n_def_args = n_def_args;
	o->has_def_kw_args = def_kw_args != MP_OBJ_NULL;
	o->takes_var_args = (scope_flags & MP_SCOPE_FLAG_VARARGS) != 0;
	o->takes_kw_args = (scope_flags & MP_SCOPE_FLAG_VARKEYWORDS) != 0;
	o->bytecode = code;
	if (def_args != MP_OBJ_NULL) {
	memcpy(o->extra_args, def_args->items, n_def_args * sizeof(mp_obj_t));
	}
	if (def_kw_args != MP_OBJ_NULL) {
	o->extra_args[n_def_args] = def_kw_args;
	}
	return o;
	}

	/******************************************************************************/
	/* inline assembler functions */

	typedef struct _mp_obj_fun_asm_t {
	mp_obj_base_t base;
	int n_args;
	void *fun;
	} mp_obj_fun_asm_t;

	typedef mp_uint_t (*inline_asm_fun_0_t)();
	typedef mp_uint_t (*inline_asm_fun_1_t)(mp_uint_t);
	typedef mp_uint_t (*inline_asm_fun_2_t)(mp_uint_t, mp_uint_t);
	typedef mp_uint_t (*inline_asm_fun_3_t)(mp_uint_t, mp_uint_t, mp_uint_t);

	// convert a Micro Python object to a sensible value for inline asm
	STATIC mp_uint_t convert_obj_for_inline_asm(mp_obj_t obj) {
	// TODO for byte_array, pass pointer to the array
	if (MP_OBJ_IS_SMALL_INT(obj)) {
	return MP_OBJ_SMALL_INT_VALUE(obj);
	} else if (obj == mp_const_none) {
	return 0;
	} else if (obj == mp_const_false) {
	return 0;
	} else if (obj == mp_const_true) {
	return 1;
	} else if (MP_OBJ_IS_STR(obj)) {
	// pointer to the string (it's probably constant though!)
	uint l;
	return (mp_uint_t)mp_obj_str_get_data(obj, &l);
	} else {
	mp_obj_type_t *type = mp_obj_get_type(obj);
	if (0) {
	#if MICROPY_PY_BUILTINS_FLOAT
	} else if (type == &mp_type_float) {
	// convert float to int (could also pass in float registers)
	return (mp_int_t)mp_obj_float_get(obj);
	#endif
	} else if (type == &mp_type_tuple) {
	// pointer to start of tuple (could pass length, but then could use len(x) for that)
	uint len;
	mp_obj_t *items;
	mp_obj_tuple_get(obj, &len, &items);
	return (mp_uint_t)items;
	} else if (type == &mp_type_list) {
	// pointer to start of list (could pass length, but then could use len(x) for that)
	uint len;
	mp_obj_t *items;
	mp_obj_list_get(obj, &len, &items);
	return (mp_uint_t)items;
	} else {
	mp_buffer_info_t bufinfo;
	if (mp_get_buffer(obj, &bufinfo, MP_BUFFER_WRITE)) {
	// supports the buffer protocol, return a pointer to the data
	return (mp_uint_t)bufinfo.buf;
	} else {
	// just pass along a pointer to the object
	return (mp_uint_t)obj;
	}
	}
	}
	}

	// convert a return value from inline asm to a sensible Micro Python object
	STATIC mp_obj_t convert_val_from_inline_asm(mp_uint_t val) {
	return MP_OBJ_NEW_SMALL_INT(val);
	}

	STATIC mp_obj_t fun_asm_call(mp_obj_t self_in, uint n_args, uint n_kw, const mp_obj_t *args) {
	mp_obj_fun_asm_t *self = self_in;

	mp_arg_check_num(n_args, n_kw, self->n_args, self->n_args, false);

	mp_uint_t ret;
	if (n_args == 0) {
	ret = ((inline_asm_fun_0_t)self->fun)();
	} else if (n_args == 1) {
	ret = ((inline_asm_fun_1_t)self->fun)(convert_obj_for_inline_asm(args[0]));
	} else if (n_args == 2) {
	ret = ((inline_asm_fun_2_t)self->fun)(convert_obj_for_inline_asm(args[0]), convert_obj_for_inline_asm(args[1]));
	} else if (n_args == 3) {
	ret = ((inline_asm_fun_3_t)self->fun)(convert_obj_for_inline_asm(args[0]), convert_obj_for_inline_asm(args[1]), convert_obj_for_inline_asm(args[2]));
	} else {
	assert(0);
	ret = 0;
	}

	return convert_val_from_inline_asm(ret);
	}

	STATIC const mp_obj_type_t mp_type_fun_asm = {
	{ &mp_type_type },
	.name = MP_QSTR_function,
	.call = fun_asm_call,
	.binary_op = fun_binary_op,
	};

	mp_obj_t mp_obj_new_fun_asm(uint n_args, void *fun) {
	mp_obj_fun_asm_t *o = m_new_obj(mp_obj_fun_asm_t);
	o->base.type = &mp_type_fun_asm;
	o->n_args = n_args;
	o->fun = fun;
	return o;
	}