text: /*
   * This file is part of the MicroPython project, http://micropython.org/
   *
   * The MIT License (MIT)
   *
   * Copyright (c) 2013, 2014 Damien P. George
   * Copyright (c) 2014-2018 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 <string.h>
  #include <assert.h>
  
  #include "py/objtuple.h"
  #include "py/objfun.h"
  #include "py/runtime.h"
  #include "py/bc.h"
  #include "py/stackctrl.h"
  
  #if MICROPY_DEBUG_VERBOSE // print debugging info
  #define DEBUG_PRINT (1)
  #else // don't print debugging info
  #define DEBUG_PRINT (0)
  #define DEBUG_printf(...) (void)0
  #endif
  
  // Note: the "name" entry in mp_obj_type_t for a function type must be
  // MP_QSTR_function because it is used to determine if an object is of generic
  // function type.
  
  /******************************************************************************/
  /* builtin functions                                                          */
  
  STATIC mp_obj_t fun_builtin_0_call(mp_obj_t self_in, size_t n_args, size_t n_kw, const mp_obj_t *args) {
      (void)args;
      assert(mp_obj_is_type(self_in, &mp_type_fun_builtin_0));
      mp_obj_fun_builtin_fixed_t *self = MP_OBJ_TO_PTR(self_in);
      mp_arg_check_num(n_args, n_kw, 0, 0, false);
      return self->fun._0();
  }
  
  const mp_obj_type_t mp_type_fun_builtin_0 = {
      { &mp_type_type },
      .name = MP_QSTR_function,
      .call = fun_builtin_0_call,
      .unary_op = mp_generic_unary_op,
  };
  
  STATIC mp_obj_t fun_builtin_1_call(mp_obj_t self_in, size_t n_args, size_t n_kw, const mp_obj_t *args) {
      assert(mp_obj_is_type(self_in, &mp_type_fun_builtin_1));
      mp_obj_fun_builtin_fixed_t *self = MP_OBJ_TO_PTR(self_in);
      mp_arg_check_num(n_args, n_kw, 1, 1, false);
      return self->fun._1(args[0]);
  }
  
  const mp_obj_type_t mp_type_fun_builtin_1 = {
      { &mp_type_type },
      .name = MP_QSTR_function,
      .call = fun_builtin_1_call,
      .unary_op = mp_generic_unary_op,
  };
  
  STATIC mp_obj_t fun_builtin_2_call(mp_obj_t self_in, size_t n_args, size_t n_kw, const mp_obj_t *args) {
      assert(mp_obj_is_type(self_in, &mp_type_fun_builtin_2));
      mp_obj_fun_builtin_fixed_t *self = MP_OBJ_TO_PTR(self_in);
      mp_arg_check_num(n_args, n_kw, 2, 2, false);
      return self->fun._2(args[0], args[1]);
  }
  
  const mp_obj_type_t mp_type_fun_builtin_2 = {
      { &mp_type_type },
      .name = MP_QSTR_function,
      .call = fun_builtin_2_call,
      .unary_op = mp_generic_unary_op,
  };
  
  STATIC mp_obj_t fun_builtin_3_call(mp_obj_t self_in, size_t n_args, size_t n_kw, const mp_obj_t *args) {
      assert(mp_obj_is_type(self_in, &mp_type_fun_builtin_3));
      mp_obj_fun_builtin_fixed_t *self = MP_OBJ_TO_PTR(self_in);
      mp_arg_check_num(n_args, n_kw, 3, 3, false);
      return self->fun._3(args[0], args[1], args[2]);
  }
  
  const mp_obj_type_t mp_type_fun_builtin_3 = {
      { &mp_type_type },
      .name = MP_QSTR_function,
      .call = fun_builtin_3_call,
      .unary_op = mp_generic_unary_op,
  };
  
  STATIC mp_obj_t fun_builtin_var_call(mp_obj_t self_in, size_t n_args, size_t n_kw, const mp_obj_t *args) {
      assert(mp_obj_is_type(self_in, &mp_type_fun_builtin_var));
      mp_obj_fun_builtin_var_t *self = MP_OBJ_TO_PTR(self_in);
  
      // check number of arguments
      mp_arg_check_num_sig(n_args, n_kw, self->sig);
  
      if (self->sig & 1) {
          // 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 self->fun.kw(n_args, args, &kw_args);
  
      } else {
          // function takes a variable number of arguments, but no keywords
  
          return self->fun.var(n_args, args);
      }
  }
  
  const mp_obj_type_t mp_type_fun_builtin_var = {
      { &mp_type_type },
      .name = MP_QSTR_function,
      .call = fun_builtin_var_call,
      .unary_op = mp_generic_unary_op,
  };
  
  /******************************************************************************/
  /* byte code functions                                                        */
  
  qstr mp_obj_code_get_name(const byte *code_info) {
      code_info = mp_decode_uint_skip(code_info); // skip code_info_size entry
      #if MICROPY_PERSISTENT_CODE
      return code_info[0] | (code_info[1] << 8);
      #else
      return mp_decode_uint_value(code_info);
      #endif
  }
  
  #if MICROPY_EMIT_NATIVE
  STATIC const mp_obj_type_t mp_type_fun_native;
  #endif
  
  qstr mp_obj_fun_get_name(mp_const_obj_t fun_in) {
      const mp_obj_fun_bc_t *fun = MP_OBJ_TO_PTR(fun_in);
      #if MICROPY_EMIT_NATIVE
      if (fun->base.type == &mp_type_fun_native || fun->base.type == &mp_type_native_gen_wrap) {
          // TODO native functions don't have name stored
          return MP_QSTR_;
      }
      #endif
  
      const byte *bc = fun->bytecode;
      bc = mp_decode_uint_skip(bc); // skip n_state
      bc = mp_decode_uint_skip(bc); // skip n_exc_stack
      bc++; // skip scope_params
      bc++; // skip n_pos_args
      bc++; // skip n_kwonly_args
      bc++; // skip n_def_pos_args
      return mp_obj_code_get_name(bc);
  }
  
  #if MICROPY_CPYTHON_COMPAT
  STATIC void fun_bc_print(const mp_print_t *print, mp_obj_t o_in, mp_print_kind_t kind) {
      (void)kind;
      mp_obj_fun_bc_t *o = MP_OBJ_TO_PTR(o_in);
      mp_printf(print, "<function %q at 0x%p>", mp_obj_fun_get_name(o_in), o);
  }
  #endif
  
  #if DEBUG_PRINT
  STATIC void dump_args(const mp_obj_t *a, size_t sz) {
      DEBUG_printf("%p: ", a);
      for (size_t i = 0; i < sz; i++) {
          DEBUG_printf("%p ", a[i]);
      }
      DEBUG_printf("\n");
  }
  #else
  #define dump_args(...) (void)0
  #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 try to use the heap, with fallback to stack allocation.
  #define VM_MAX_STATE_ON_STACK (11 * sizeof(mp_uint_t))
  
  #define DECODE_CODESTATE_SIZE(bytecode, n_state_out_var, state_size_out_var) \
      { \
          /* bytecode prelude: state size and exception stack size */               \
          n_state_out_var = mp_decode_uint_value(bytecode);                         \
          size_t n_exc_stack = mp_decode_uint_value(mp_decode_uint_skip(bytecode)); \
                                                                                    \
          /* state size in bytes */                                                 \
          state_size_out_var = n_state_out_var * sizeof(mp_obj_t)                   \
                             + n_exc_stack * sizeof(mp_exc_stack_t);                \
      }
  
  #define INIT_CODESTATE(code_state, _fun_bc, n_args, n_kw, args) \
      code_state->fun_bc = _fun_bc; \
      code_state->ip = 0; \
      mp_setup_code_state(code_state, n_args, n_kw, args); \
      code_state->old_globals = mp_globals_get();
  
  #if MICROPY_STACKLESS
  mp_code_state_t *mp_obj_fun_bc_prepare_codestate(mp_obj_t self_in, size_t n_args, size_t n_kw, const mp_obj_t *args) {
      MP_STACK_CHECK();
      mp_obj_fun_bc_t *self = MP_OBJ_TO_PTR(self_in);
  
      size_t n_state, state_size;
      DECODE_CODESTATE_SIZE(self->bytecode, n_state, state_size);
  
      mp_code_state_t *code_state;
      #if MICROPY_ENABLE_PYSTACK
      code_state = mp_pystack_alloc(sizeof(mp_code_state_t) + state_size);
      #else
      // If we use m_new_obj_var(), then on no memory, MemoryError will be
      // raised. But this is not correct exception for a function call,
      // RuntimeError should be raised instead. So, we use m_new_obj_var_maybe(),
      // return NULL, then vm.c takes the needed action (either raise
      // RuntimeError or fallback to stack allocation).
      code_state = m_new_obj_var_maybe(mp_code_state_t, byte, state_size);
      if (!code_state) {
          return NULL;
      }
      #endif
  
      #if MICROPY_ACCESS_CODE_STATE
      MP_STATE_THREAD(code_state) = code_state;
      #endif
  
      INIT_CODESTATE(code_state, self, n_args, n_kw, args);
  
      // execute the byte code with the correct globals context
      mp_globals_set(self->globals);
  
      return code_state;
  }
  #endif
  
  STATIC mp_obj_t fun_bc_call(mp_obj_t self_in, size_t n_args, size_t n_kw, const mp_obj_t *args) {
      MP_STACK_CHECK();
  
      DEBUG_printf("Input n_args: " UINT_FMT ", n_kw: " UINT_FMT "\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 = MP_OBJ_TO_PTR(self_in);
  
      size_t n_state, state_size;
      DECODE_CODESTATE_SIZE(self->bytecode, n_state, state_size);
  
      // allocate state for locals and stack
      mp_code_state_t *code_state = NULL;
      #if MICROPY_ENABLE_PYSTACK
      code_state = mp_pystack_alloc(sizeof(mp_code_state_t) + state_size);
      #else
      if (state_size > VM_MAX_STATE_ON_STACK) {
          code_state = m_new_obj_var_maybe(mp_code_state_t, byte, state_size);
          #if MICROPY_DEBUG_VM_STACK_OVERFLOW
          if (code_state != NULL) {
              memset(code_state->state, 0, state_size);
          }
          #endif
      }
      if (code_state == NULL) {
          code_state = alloca(sizeof(mp_code_state_t) + state_size);
          #if MICROPY_DEBUG_VM_STACK_OVERFLOW
          memset(code_state->state, 0, state_size);
          #endif
          state_size = 0; // indicate that we allocated using alloca
      }
      #endif
  
      #if MICROPY_ACCESS_CODE_STATE
      MP_STATE_THREAD(code_state) = code_state;
      #endif
  
      INIT_CODESTATE(code_state, self, n_args, n_kw, args);
  
      // execute the byte code with the correct globals context
      mp_globals_set(self->globals);
      mp_vm_return_kind_t vm_return_kind = mp_execute_bytecode(code_state, MP_OBJ_NULL);
      mp_globals_set(code_state->old_globals);
  
      #if MICROPY_DEBUG_VM_STACK_OVERFLOW
      if (vm_return_kind == MP_VM_RETURN_NORMAL) {
          if (code_state->sp < code_state->state) {
              mp_printf(MICROPY_DEBUG_PRINTER, "VM stack underflow: " INT_FMT "\n", code_state->sp - code_state->state);
              assert(0);
          }
      }
      const byte *bytecode_ptr = mp_decode_uint_skip(mp_decode_uint_skip(self->bytecode));
      size_t n_pos_args = bytecode_ptr[1];
      size_t n_kwonly_args = bytecode_ptr[2];
      // We can't check the case when an exception is returned in state[0]
      // 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 && n_pos_args + n_kwonly_args == 0)) {
          // Just check to see that we have at least 1 null object left in the state.
          bool overflow = true;
          for (size_t i = 0; i < n_state - n_pos_args - n_kwonly_args; ++i) {
              if (code_state->state[i] == MP_OBJ_NULL) {
                  overflow = false;
                  break;
              }
          }
          if (overflow) {
              mp_printf(MICROPY_DEBUG_PRINTER, "VM stack overflow state=%p n_state+1=" UINT_FMT "\n", code_state->state, n_state);
              assert(0);
          }
      }
      #endif
  
      mp_obj_t result;
      if (vm_return_kind == MP_VM_RETURN_NORMAL) {
          // return value is in *sp
          result = *code_state->sp;
      } else {
          // must be an exception because normal functions can't yield
          assert(vm_return_kind == MP_VM_RETURN_EXCEPTION);
          // returned exception is in state[0]
          result = code_state->state[0];
      }
  
      #if MICROPY_ENABLE_PYSTACK
      mp_pystack_free(code_state);
      #else
      // free the state if it was allocated on the heap
      if (state_size != 0) {
          m_del_var(mp_code_state_t, byte, state_size, code_state);
      }
      #endif
  
      if (vm_return_kind == MP_VM_RETURN_NORMAL) {
          return result;
      } else { // MP_VM_RETURN_EXCEPTION
          nlr_raise(result);
      }
  }
  
  #if MICROPY_PY_FUNCTION_ATTRS
  void mp_obj_fun_bc_attr(mp_obj_t self_in, qstr attr, mp_obj_t *dest) {
      if (dest[0] != MP_OBJ_NULL) {
          // not load attribute
          return;
      }
      if (attr == MP_QSTR___name__) {
          dest[0] = MP_OBJ_NEW_QSTR(mp_obj_fun_get_name(self_in));
      }
  }
  #endif
  
  #if MICROPY_PY_FUNCTION_CONSTRUCTOR
  STATIC mp_obj_t fun_bc_make_new(const mp_obj_type_t *type, size_t n_args, size_t n_kw, const mp_obj_t *args) {
      // code, const_table, globals, argdefs
      mp_arg_check_num(n_args, n_kw, 3, 4, false);
  
      mp_buffer_info_t bufinfo;
      mp_get_buffer_raise(args[0], &bufinfo, MP_BUFFER_READ);
      const byte *bytecode = bufinfo.buf;
      mp_get_buffer_raise(args[1], &bufinfo, MP_BUFFER_READ);
  
      mp_obj_t argdefs = MP_OBJ_NULL;
      if (n_args > 3) {
          argdefs = args[3];
      }
  
      mp_obj_t fun = mp_obj_new_fun_bc(argdefs, MP_OBJ_NULL, bytecode, bufinfo.buf);
      mp_obj_fun_bc_t *o = MP_OBJ_TO_PTR(fun);
      o->globals = args[2];
  
      return fun;
  }
  #endif
  
  const mp_obj_type_t mp_type_fun_bc = {
      { &mp_type_type },
      .name = MP_QSTR_function,
      #if MICROPY_PY_FUNCTION_CONSTRUCTOR
      .make_new = fun_bc_make_new,
      #endif
  #if MICROPY_CPYTHON_COMPAT
      .print = fun_bc_print,
  #endif
      .call = fun_bc_call,
      .unary_op = mp_generic_unary_op,
  #if MICROPY_PY_FUNCTION_ATTRS
      .attr = mp_obj_fun_bc_attr,
  #endif
  };
  
  mp_obj_t mp_obj_new_fun_bc(mp_obj_t def_args_in, mp_obj_t def_kw_args, const byte *code, const mp_uint_t *const_table) {
      size_t n_def_args = 0;
      size_t n_extra_args = 0;
      mp_obj_tuple_t *def_args = MP_OBJ_TO_PTR(def_args_in);
      if (def_args_in != MP_OBJ_NULL) {
          assert(mp_obj_is_type(def_args_in, &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->bytecode = code;
      o->const_table = const_table;
      if (def_args != 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 MP_OBJ_FROM_PTR(o);
  }
  
  /******************************************************************************/
  /* native functions                                                           */
  
  #if MICROPY_EMIT_NATIVE
  
  STATIC mp_obj_t fun_native_call(mp_obj_t self_in, size_t n_args, size_t n_kw, const mp_obj_t *args) {
      MP_STACK_CHECK();
      mp_obj_fun_bc_t *self = self_in;
      mp_call_fun_t fun = MICROPY_MAKE_POINTER_CALLABLE((void*)self->bytecode);
      return fun(self_in, n_args, n_kw, args);
  }
  
  STATIC const mp_obj_type_t mp_type_fun_native = {
      { &mp_type_type },
      .name = MP_QSTR_function,
      .call = fun_native_call,
      .unary_op = mp_generic_unary_op,
  };
  
  mp_obj_t mp_obj_new_fun_native(mp_obj_t def_args_in, mp_obj_t def_kw_args, const void *fun_data, const mp_uint_t *const_table) {
      mp_obj_fun_bc_t *o = mp_obj_new_fun_bc(def_args_in, def_kw_args, (const byte*)fun_data, const_table);
      o->base.type = &mp_type_fun_native;
      return o;
  }
  
  #endif // MICROPY_EMIT_NATIVE
  
  /******************************************************************************/
  /* inline assembler functions                                                 */
  
  #if MICROPY_EMIT_INLINE_ASM
  
  typedef struct _mp_obj_fun_asm_t {
      mp_obj_base_t base;
      size_t n_args;
      const void *fun_data; // GC must be able to trace this pointer
      mp_uint_t type_sig;
  } mp_obj_fun_asm_t;
  
  typedef mp_uint_t (*inline_asm_fun_0_t)(void);
  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);
  typedef mp_uint_t (*inline_asm_fun_4_t)(mp_uint_t, mp_uint_t, mp_uint_t, mp_uint_t);
  
  // convert a MicroPython 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_type(obj, &mp_type_int)) {
          return mp_obj_int_get_truncated(obj);
      } else if (mp_obj_is_str(obj)) {
          // pointer to the string (it's probably constant though!)
          size_t l;
          return (mp_uint_t)mp_obj_str_get_data(obj, &l);
      } else {
          mp_obj_type_t *type = mp_obj_get_type(obj);
  #if MICROPY_PY_BUILTINS_FLOAT
          if (type == &mp_type_float) {
              // convert float to int (could also pass in float registers)
              return (mp_int_t)mp_obj_float_get(obj);
          } else
  #endif
          if (type == &mp_type_tuple || type == &mp_type_list) {
              // pointer to start of tuple (could pass length, but then could use len(x) for that)
              size_t len;
              mp_obj_t *items;
              mp_obj_get_array(obj, &len, &items);
              return (mp_uint_t)items;
          } else {
              mp_buffer_info_t bufinfo;
              if (mp_get_buffer(obj, &bufinfo, MP_BUFFER_READ)) {
                  // 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;
              }
          }
      }
  }
  
  STATIC mp_obj_t fun_asm_call(mp_obj_t self_in, size_t n_args, size_t 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);
  
      const void *fun = MICROPY_MAKE_POINTER_CALLABLE(self->fun_data);
  
      mp_uint_t ret;
      if (n_args == 0) {
          ret = ((inline_asm_fun_0_t)fun)();
      } else if (n_args == 1) {
          ret = ((inline_asm_fun_1_t)fun)(convert_obj_for_inline_asm(args[0]));
      } else if (n_args == 2) {
          ret = ((inline_asm_fun_2_t)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)fun)(convert_obj_for_inline_asm(args[0]), convert_obj_for_inline_asm(args[1]), convert_obj_for_inline_asm(args[2]));
      } else {
          // compiler allows at most 4 arguments
          assert(n_args == 4);
          ret = ((inline_asm_fun_4_t)fun)(
              convert_obj_for_inline_asm(args[0]),
              convert_obj_for_inline_asm(args[1]),
              convert_obj_for_inline_asm(args[2]),
              convert_obj_for_inline_asm(args[3])
          );
      }
  
      return mp_native_to_obj(ret, self->type_sig);
  }
  
  STATIC const mp_obj_type_t mp_type_fun_asm = {
      { &mp_type_type },
      .name = MP_QSTR_function,
      .call = fun_asm_call,
      .unary_op = mp_generic_unary_op,
  };
  
  mp_obj_t mp_obj_new_fun_asm(size_t n_args, const void *fun_data, mp_uint_t type_sig) {
      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_data = fun_data;
      o->type_sig = type_sig;
      return o;
  }
  
  #endif // MICROPY_EMIT_INLINE_ASM
  