text: /*
   * This file is part of the MicroPython project, http://micropython.org/
   *
   * The MIT License (MIT)
   *
   * Copyright (c) 2013, 2014 Damien P. George
   *
   * 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 <stdlib.h>
  #include <stdio.h>
  #include <stdint.h>
  #include <string.h>
  
  #include "py/compile.h"
  #include "py/runtime.h"
  #include "py/repl.h"
  #include "py/gc.h"
  #include "py/frozenmod.h"
  #include "py/mphal.h"
  #if MICROPY_HW_ENABLE_USB
  #include "irq.h"
  #include "usb.h"
  #endif
  #include "lib/mp-readline/readline.h"
  #include "lib/utils/pyexec.h"
  #include "genhdr/mpversion.h"
  
  pyexec_mode_kind_t pyexec_mode_kind = PYEXEC_MODE_FRIENDLY_REPL;
  int pyexec_system_exit = 0;
  
  #if MICROPY_REPL_INFO
  STATIC bool repl_display_debugging_info = 0;
  #endif
  
  #define EXEC_FLAG_PRINT_EOF (1)
  #define EXEC_FLAG_ALLOW_DEBUGGING (2)
  #define EXEC_FLAG_IS_REPL (4)
  #define EXEC_FLAG_SOURCE_IS_RAW_CODE (8)
  #define EXEC_FLAG_SOURCE_IS_VSTR (16)
  #define EXEC_FLAG_SOURCE_IS_FILENAME (32)
  #define EXEC_FLAG_SOURCE_IS_READER (64)
  
  // parses, compiles and executes the code in the lexer
  // frees the lexer before returning
  // EXEC_FLAG_PRINT_EOF prints 2 EOF chars: 1 after normal output, 1 after exception output
  // EXEC_FLAG_ALLOW_DEBUGGING allows debugging info to be printed after executing the code
  // EXEC_FLAG_IS_REPL is used for REPL inputs (flag passed on to mp_compile)
  STATIC int parse_compile_execute(const void *source, mp_parse_input_kind_t input_kind, int exec_flags) {
      int ret = 0;
      #if MICROPY_REPL_INFO
      uint32_t start = 0;
      #endif
  
      #ifdef MICROPY_BOARD_BEFORE_PYTHON_EXEC
      MICROPY_BOARD_BEFORE_PYTHON_EXEC(input_kind, exec_flags);
      #endif
  
      // by default a SystemExit exception returns 0
      pyexec_system_exit = 0;
  
      nlr_buf_t nlr;
      nlr.ret_val = NULL;
      if (nlr_push(&nlr) == 0) {
          mp_obj_t module_fun;
          #if MICROPY_MODULE_FROZEN_MPY
          if (exec_flags & EXEC_FLAG_SOURCE_IS_RAW_CODE) {
              // source is a raw_code object, create the function
              module_fun = mp_make_function_from_raw_code(source, MP_OBJ_NULL, MP_OBJ_NULL);
          } else
          #endif
          {
              #if MICROPY_ENABLE_COMPILER
              mp_lexer_t *lex;
              if (exec_flags & EXEC_FLAG_SOURCE_IS_VSTR) {
                  const vstr_t *vstr = source;
                  lex = mp_lexer_new_from_str_len(MP_QSTR__lt_stdin_gt_, vstr->buf, vstr->len, 0);
              } else if (exec_flags & EXEC_FLAG_SOURCE_IS_READER) {
                  lex = mp_lexer_new(MP_QSTR__lt_stdin_gt_, *(mp_reader_t *)source);
              } else if (exec_flags & EXEC_FLAG_SOURCE_IS_FILENAME) {
                  lex = mp_lexer_new_from_file(source);
              } else {
                  lex = (mp_lexer_t *)source;
              }
              // source is a lexer, parse and compile the script
              qstr source_name = lex->source_name;
              mp_parse_tree_t parse_tree = mp_parse(lex, input_kind);
              module_fun = mp_compile(&parse_tree, source_name, exec_flags & EXEC_FLAG_IS_REPL);
              #else
              mp_raise_msg(&mp_type_RuntimeError, MP_ERROR_TEXT("script compilation not supported"));
              #endif
          }
  
          // execute code
          mp_hal_set_interrupt_char(CHAR_CTRL_C); // allow ctrl-C to interrupt us
          #if MICROPY_REPL_INFO
          start = mp_hal_ticks_ms();
          #endif
          mp_call_function_0(module_fun);
          mp_hal_set_interrupt_char(-1); // disable interrupt
          mp_handle_pending(true); // handle any pending exceptions (and any callbacks)
          nlr_pop();
          ret = 1;
          if (exec_flags & EXEC_FLAG_PRINT_EOF) {
              mp_hal_stdout_tx_strn("\x04", 1);
          }
      } else {
          // uncaught exception
          mp_hal_set_interrupt_char(-1); // disable interrupt
          mp_handle_pending(false); // clear any pending exceptions (and run any callbacks)
  
          if (exec_flags & EXEC_FLAG_SOURCE_IS_READER) {
              const mp_reader_t *reader = source;
              reader->close(reader->data);
          }
  
          // print EOF after normal output
          if (exec_flags & EXEC_FLAG_PRINT_EOF) {
              mp_hal_stdout_tx_strn("\x04", 1);
          }
          // check for SystemExit
          if (mp_obj_is_subclass_fast(MP_OBJ_FROM_PTR(((mp_obj_base_t *)nlr.ret_val)->type), MP_OBJ_FROM_PTR(&mp_type_SystemExit))) {
              // at the moment, the value of SystemExit is unused
              ret = pyexec_system_exit;
          } else {
              mp_obj_print_exception(&mp_plat_print, MP_OBJ_FROM_PTR(nlr.ret_val));
              ret = 0;
          }
      }
  
      #if MICROPY_REPL_INFO
      // display debugging info if wanted
      if ((exec_flags & EXEC_FLAG_ALLOW_DEBUGGING) && repl_display_debugging_info) {
          mp_uint_t ticks = mp_hal_ticks_ms() - start; // TODO implement a function that does this properly
          printf("took " UINT_FMT " ms\n", ticks);
          // qstr info
          {
              size_t n_pool, n_qstr, n_str_data_bytes, n_total_bytes;
              qstr_pool_info(&n_pool, &n_qstr, &n_str_data_bytes, &n_total_bytes);
              printf("qstr:\n  n_pool=%u\n  n_qstr=%u\n  "
                  "n_str_data_bytes=%u\n  n_total_bytes=%u\n",
                  (unsigned)n_pool, (unsigned)n_qstr, (unsigned)n_str_data_bytes, (unsigned)n_total_bytes);
          }
  
          #if MICROPY_ENABLE_GC
          // run collection and print GC info
          gc_collect();
          gc_dump_info();
          #endif
      }
      #endif
  
      if (exec_flags & EXEC_FLAG_PRINT_EOF) {
          mp_hal_stdout_tx_strn("\x04", 1);
      }
  
      #ifdef MICROPY_BOARD_AFTER_PYTHON_EXEC
      MICROPY_BOARD_AFTER_PYTHON_EXEC(input_kind, exec_flags, nlr.ret_val, &ret);
      #endif
  
      return ret;
  }
  
  #if MICROPY_ENABLE_COMPILER
  
  // This can be configured by a port (and even configured to a function to be
  // computed dynamically) to indicate the maximum number of bytes that can be
  // held in the stdin buffer.
  #ifndef MICROPY_REPL_STDIN_BUFFER_MAX
  #define MICROPY_REPL_STDIN_BUFFER_MAX (256)
  #endif
  
  typedef struct _mp_reader_stdin_t {
      bool eof;
      uint16_t window_max;
      uint16_t window_remain;
  } mp_reader_stdin_t;
  
  STATIC mp_uint_t mp_reader_stdin_readbyte(void *data) {
      mp_reader_stdin_t *reader = (mp_reader_stdin_t *)data;
  
      if (reader->eof) {
          return MP_READER_EOF;
      }
  
      int c = mp_hal_stdin_rx_chr();
  
      if (c == CHAR_CTRL_C || c == CHAR_CTRL_D) {
          reader->eof = true;
          mp_hal_stdout_tx_strn("\x04", 1); // indicate end to host
          if (c == CHAR_CTRL_C) {
              #if MICROPY_KBD_EXCEPTION
              MP_STATE_VM(mp_kbd_exception).traceback_data = NULL;
              nlr_raise(MP_OBJ_FROM_PTR(&MP_STATE_VM(mp_kbd_exception)));
              #else
              mp_raise_type(&mp_type_KeyboardInterrupt);
              #endif
          } else {
              return MP_READER_EOF;
          }
      }
  
      if (--reader->window_remain == 0) {
          mp_hal_stdout_tx_strn("\x01", 1); // indicate window available to host
          reader->window_remain = reader->window_max;
      }
  
      return c;
  }
  
  STATIC void mp_reader_stdin_close(void *data) {
      mp_reader_stdin_t *reader = (mp_reader_stdin_t *)data;
      if (!reader->eof) {
          reader->eof = true;
          mp_hal_stdout_tx_strn("\x04", 1); // indicate end to host
          for (;;) {
              int c = mp_hal_stdin_rx_chr();
              if (c == CHAR_CTRL_C || c == CHAR_CTRL_D) {
                  break;
              }
          }
      }
  }
  
  STATIC void mp_reader_new_stdin(mp_reader_t *reader, mp_reader_stdin_t *reader_stdin, uint16_t buf_max) {
      // Make flow-control window half the buffer size, and indicate to the host that 2x windows are
      // free (sending the window size implicitly indicates that a window is free, and then the 0x01
      // indicates that another window is free).
      size_t window = buf_max / 2;
      char reply[3] = { window & 0xff, window >> 8, 0x01 };
      mp_hal_stdout_tx_strn(reply, sizeof(reply));
  
      reader_stdin->eof = false;
      reader_stdin->window_max = window;
      reader_stdin->window_remain = window;
      reader->data = reader_stdin;
      reader->readbyte = mp_reader_stdin_readbyte;
      reader->close = mp_reader_stdin_close;
  }
  
  STATIC int do_reader_stdin(int c) {
      if (c != 'A') {
          // Unsupported command.
          mp_hal_stdout_tx_strn("R\x00", 2);
          return 0;
      }
  
      // Indicate reception of command.
      mp_hal_stdout_tx_strn("R\x01", 2);
  
      mp_reader_t reader;
      mp_reader_stdin_t reader_stdin;
      mp_reader_new_stdin(&reader, &reader_stdin, MICROPY_REPL_STDIN_BUFFER_MAX);
      int exec_flags = EXEC_FLAG_PRINT_EOF | EXEC_FLAG_SOURCE_IS_READER;
      return parse_compile_execute(&reader, MP_PARSE_FILE_INPUT, exec_flags);
  }
  
  #if MICROPY_REPL_EVENT_DRIVEN
  
  typedef struct _repl_t {
      // This structure originally also held current REPL line,
      // but it was moved to MP_STATE_VM(repl_line) as containing
      // root pointer. Still keep structure in case more state
      // will be added later.
      // vstr_t line;
      bool cont_line;
      bool paste_mode;
  } repl_t;
  
  repl_t repl;
  
  STATIC int pyexec_raw_repl_process_char(int c);
  STATIC int pyexec_friendly_repl_process_char(int c);
  
  void pyexec_event_repl_init(void) {
      MP_STATE_VM(repl_line) = vstr_new(32);
      repl.cont_line = false;
      repl.paste_mode = false;
      // no prompt before printing friendly REPL banner or entering raw REPL
      readline_init(MP_STATE_VM(repl_line), "");
      if (pyexec_mode_kind == PYEXEC_MODE_RAW_REPL) {
          pyexec_raw_repl_process_char(CHAR_CTRL_A);
      } else {
          pyexec_friendly_repl_process_char(CHAR_CTRL_B);
      }
  }
  
  STATIC int pyexec_raw_repl_process_char(int c) {
      if (c == CHAR_CTRL_A) {
          // reset raw REPL
          if (vstr_len(MP_STATE_VM(repl_line)) == 2 && vstr_str(MP_STATE_VM(repl_line))[0] == CHAR_CTRL_E) {
              int ret = do_reader_stdin(vstr_str(MP_STATE_VM(repl_line))[1]);
              if (ret & PYEXEC_FORCED_EXIT) {
                  return ret;
              }
              goto reset;
          }
          mp_hal_stdout_tx_str("raw REPL; CTRL-B to exit\r\n");
          goto reset;
      } else if (c == CHAR_CTRL_B) {
          // change to friendly REPL
          pyexec_mode_kind = PYEXEC_MODE_FRIENDLY_REPL;
          vstr_reset(MP_STATE_VM(repl_line));
          repl.cont_line = false;
          repl.paste_mode = false;
          pyexec_friendly_repl_process_char(CHAR_CTRL_B);
          return 0;
      } else if (c == CHAR_CTRL_C) {
          // clear line
          vstr_reset(MP_STATE_VM(repl_line));
          return 0;
      } else if (c == CHAR_CTRL_D) {
          // input finished
      } else {
          // let through any other raw 8-bit value
          vstr_add_byte(MP_STATE_VM(repl_line), c);
          return 0;
      }
  
      // indicate reception of command
      mp_hal_stdout_tx_str("OK");
  
      if (MP_STATE_VM(repl_line)->len == 0) {
          // exit for a soft reset
          mp_hal_stdout_tx_str("\r\n");
          vstr_clear(MP_STATE_VM(repl_line));
          return PYEXEC_FORCED_EXIT;
      }
  
      int ret = parse_compile_execute(MP_STATE_VM(repl_line), MP_PARSE_FILE_INPUT, EXEC_FLAG_PRINT_EOF | EXEC_FLAG_SOURCE_IS_VSTR);
      if (ret & PYEXEC_FORCED_EXIT) {
          return ret;
      }
  
  reset:
      vstr_reset(MP_STATE_VM(repl_line));
      mp_hal_stdout_tx_str(">");
  
      return 0;
  }
  
  STATIC int pyexec_friendly_repl_process_char(int c) {
      if (repl.paste_mode) {
          if (c == CHAR_CTRL_C) {
              // cancel everything
              mp_hal_stdout_tx_str("\r\n");
              goto input_restart;
          } else if (c == CHAR_CTRL_D) {
              // end of input
              mp_hal_stdout_tx_str("\r\n");
              int ret = parse_compile_execute(MP_STATE_VM(repl_line), MP_PARSE_FILE_INPUT, EXEC_FLAG_ALLOW_DEBUGGING | EXEC_FLAG_IS_REPL | EXEC_FLAG_SOURCE_IS_VSTR);
              if (ret & PYEXEC_FORCED_EXIT) {
                  return ret;
              }
              goto input_restart;
          } else {
              // add char to buffer and echo
              vstr_add_byte(MP_STATE_VM(repl_line), c);
              if (c == '\r') {
                  mp_hal_stdout_tx_str("\r\n=== ");
              } else {
                  char buf[1] = {c};
                  mp_hal_stdout_tx_strn(buf, 1);
              }
              return 0;
          }
      }
  
      int ret = readline_process_char(c);
  
      if (!repl.cont_line) {
  
          if (ret == CHAR_CTRL_A) {
              // change to raw REPL
              pyexec_mode_kind = PYEXEC_MODE_RAW_REPL;
              mp_hal_stdout_tx_str("\r\n");
              pyexec_raw_repl_process_char(CHAR_CTRL_A);
              return 0;
          } else if (ret == CHAR_CTRL_B) {
              // reset friendly REPL
              mp_hal_stdout_tx_str("\r\n");
              mp_hal_stdout_tx_str("MicroPython " MICROPY_GIT_TAG " on " MICROPY_BUILD_DATE "; " MICROPY_HW_BOARD_NAME " with " MICROPY_HW_MCU_NAME "\r\n");
              #if MICROPY_PY_BUILTINS_HELP
              mp_hal_stdout_tx_str("Type \"help()\" for more information.\r\n");
              #endif
              goto input_restart;
          } else if (ret == CHAR_CTRL_C) {
              // break
              mp_hal_stdout_tx_str("\r\n");
              goto input_restart;
          } else if (ret == CHAR_CTRL_D) {
              // exit for a soft reset
              mp_hal_stdout_tx_str("\r\n");
              vstr_clear(MP_STATE_VM(repl_line));
              return PYEXEC_FORCED_EXIT;
          } else if (ret == CHAR_CTRL_E) {
              // paste mode
              mp_hal_stdout_tx_str("\r\npaste mode; Ctrl-C to cancel, Ctrl-D to finish\r\n=== ");
              vstr_reset(MP_STATE_VM(repl_line));
              repl.paste_mode = true;
              return 0;
          }
  
          if (ret < 0) {
              return 0;
          }
  
          if (!mp_repl_continue_with_input(vstr_null_terminated_str(MP_STATE_VM(repl_line)))) {
              goto exec;
          }
  
          vstr_add_byte(MP_STATE_VM(repl_line), '\n');
          repl.cont_line = true;
          readline_note_newline("... ");
          return 0;
  
      } else {
  
          if (ret == CHAR_CTRL_C) {
              // cancel everything
              mp_hal_stdout_tx_str("\r\n");
              repl.cont_line = false;
              goto input_restart;
          } else if (ret == CHAR_CTRL_D) {
              // stop entering compound statement
              goto exec;
          }
  
          if (ret < 0) {
              return 0;
          }
  
          if (mp_repl_continue_with_input(vstr_null_terminated_str(MP_STATE_VM(repl_line)))) {
              vstr_add_byte(MP_STATE_VM(repl_line), '\n');
              readline_note_newline("... ");
              return 0;
          }
  
      exec:;
          int ret = parse_compile_execute(MP_STATE_VM(repl_line), MP_PARSE_SINGLE_INPUT, EXEC_FLAG_ALLOW_DEBUGGING | EXEC_FLAG_IS_REPL | EXEC_FLAG_SOURCE_IS_VSTR);
          if (ret & PYEXEC_FORCED_EXIT) {
              return ret;
          }
  
      input_restart:
          vstr_reset(MP_STATE_VM(repl_line));
          repl.cont_line = false;
          repl.paste_mode = false;
          readline_init(MP_STATE_VM(repl_line), ">>> ");
          return 0;
      }
  }
  
  uint8_t pyexec_repl_active;
  int pyexec_event_repl_process_char(int c) {
      pyexec_repl_active = 1;
      int res;
      if (pyexec_mode_kind == PYEXEC_MODE_RAW_REPL) {
          res = pyexec_raw_repl_process_char(c);
      } else {
          res = pyexec_friendly_repl_process_char(c);
      }
      pyexec_repl_active = 0;
      return res;
  }
  
  #else // MICROPY_REPL_EVENT_DRIVEN
  
  int pyexec_raw_repl(void) {
      vstr_t line;
      vstr_init(&line, 32);
  
  raw_repl_reset:
      mp_hal_stdout_tx_str("raw REPL; CTRL-B to exit\r\n");
  
      for (;;) {
          vstr_reset(&line);
          mp_hal_stdout_tx_str(">");
          for (;;) {
              int c = mp_hal_stdin_rx_chr();
              if (c == CHAR_CTRL_A) {
                  // reset raw REPL
                  if (vstr_len(&line) == 2 && vstr_str(&line)[0] == CHAR_CTRL_E) {
                      int ret = do_reader_stdin(vstr_str(&line)[1]);
                      if (ret & PYEXEC_FORCED_EXIT) {
                          return ret;
                      }
                      vstr_reset(&line);
                      mp_hal_stdout_tx_str(">");
                      continue;
                  }
                  goto raw_repl_reset;
              } else if (c == CHAR_CTRL_B) {
                  // change to friendly REPL
                  mp_hal_stdout_tx_str("\r\n");
                  vstr_clear(&line);
                  pyexec_mode_kind = PYEXEC_MODE_FRIENDLY_REPL;
                  return 0;
              } else if (c == CHAR_CTRL_C) {
                  // clear line
                  vstr_reset(&line);
              } else if (c == CHAR_CTRL_D) {
                  // input finished
                  break;
              } else {
                  // let through any other raw 8-bit value
                  vstr_add_byte(&line, c);
              }
          }
  
          // indicate reception of command
          mp_hal_stdout_tx_str("OK");
  
          if (line.len == 0) {
              // exit for a soft reset
              mp_hal_stdout_tx_str("\r\n");
              vstr_clear(&line);
              return PYEXEC_FORCED_EXIT;
          }
  
          int ret = parse_compile_execute(&line, MP_PARSE_FILE_INPUT, EXEC_FLAG_PRINT_EOF | EXEC_FLAG_SOURCE_IS_VSTR);
          if (ret & PYEXEC_FORCED_EXIT) {
              return ret;
          }
      }
  }
  
  int pyexec_friendly_repl(void) {
      vstr_t line;
      vstr_init(&line, 32);
  
  friendly_repl_reset:
      mp_hal_stdout_tx_str("MicroPython " MICROPY_GIT_TAG " on " MICROPY_BUILD_DATE "; " MICROPY_HW_BOARD_NAME " with " MICROPY_HW_MCU_NAME "\r\n");
      #if MICROPY_PY_BUILTINS_HELP
      mp_hal_stdout_tx_str("Type \"help()\" for more information.\r\n");
      #endif
  
      // to test ctrl-C
      /*
      {
          uint32_t x[4] = {0x424242, 0xdeaddead, 0x242424, 0xdeadbeef};
          for (;;) {
              nlr_buf_t nlr;
              printf("pyexec_repl: %p\n", x);
              mp_hal_set_interrupt_char(CHAR_CTRL_C);
              if (nlr_push(&nlr) == 0) {
                  for (;;) {
                  }
              } else {
                  printf("break\n");
              }
          }
      }
      */
  
      for (;;) {
      input_restart:
  
          #if MICROPY_HW_ENABLE_USB
          if (usb_vcp_is_enabled()) {
              // If the user gets to here and interrupts are disabled then
              // they'll never see the prompt, traceback etc. The USB REPL needs
              // interrupts to be enabled or no transfers occur. So we try to
              // do the user a favor and reenable interrupts.
              if (query_irq() == IRQ_STATE_DISABLED) {
                  enable_irq(IRQ_STATE_ENABLED);
                  mp_hal_stdout_tx_str("MPY: enabling IRQs\r\n");
              }
          }
          #endif
  
          // If the GC is locked at this point there is no way out except a reset,
          // so force the GC to be unlocked to help the user debug what went wrong.
          if (MP_STATE_MEM(gc_lock_depth) != 0) {
              MP_STATE_MEM(gc_lock_depth) = 0;
          }
  
          vstr_reset(&line);
          int ret = readline(&line, ">>> ");
          mp_parse_input_kind_t parse_input_kind = MP_PARSE_SINGLE_INPUT;
  
          if (ret == CHAR_CTRL_A) {
              // change to raw REPL
              mp_hal_stdout_tx_str("\r\n");
              vstr_clear(&line);
              pyexec_mode_kind = PYEXEC_MODE_RAW_REPL;
              return 0;
          } else if (ret == CHAR_CTRL_B) {
              // reset friendly REPL
              mp_hal_stdout_tx_str("\r\n");
              goto friendly_repl_reset;
          } else if (ret == CHAR_CTRL_C) {
              // break
              mp_hal_stdout_tx_str("\r\n");
              continue;
          } else if (ret == CHAR_CTRL_D) {
              // exit for a soft reset
              mp_hal_stdout_tx_str("\r\n");
              vstr_clear(&line);
              return PYEXEC_FORCED_EXIT;
          } else if (ret == CHAR_CTRL_E) {
              // paste mode
              mp_hal_stdout_tx_str("\r\npaste mode; Ctrl-C to cancel, Ctrl-D to finish\r\n=== ");
              vstr_reset(&line);
              for (;;) {
                  char c = mp_hal_stdin_rx_chr();
                  if (c == CHAR_CTRL_C) {
                      // cancel everything
                      mp_hal_stdout_tx_str("\r\n");
                      goto input_restart;
                  } else if (c == CHAR_CTRL_D) {
                      // end of input
                      mp_hal_stdout_tx_str("\r\n");
                      break;
                  } else {
                      // add char to buffer and echo
                      vstr_add_byte(&line, c);
                      if (c == '\r') {
                          mp_hal_stdout_tx_str("\r\n=== ");
                      } else {
                          mp_hal_stdout_tx_strn(&c, 1);
                      }
                  }
              }
              parse_input_kind = MP_PARSE_FILE_INPUT;
          } else if (vstr_len(&line) == 0) {
              continue;
          } else {
              // got a line with non-zero length, see if it needs continuing
              while (mp_repl_continue_with_input(vstr_null_terminated_str(&line))) {
                  vstr_add_byte(&line, '\n');
                  ret = readline(&line, "... ");
                  if (ret == CHAR_CTRL_C) {
                      // cancel everything
                      mp_hal_stdout_tx_str("\r\n");
                      goto input_restart;
                  } else if (ret == CHAR_CTRL_D) {
                      // stop entering compound statement
                      break;
                  }
              }
          }
  
          ret = parse_compile_execute(&line, parse_input_kind, EXEC_FLAG_ALLOW_DEBUGGING | EXEC_FLAG_IS_REPL | EXEC_FLAG_SOURCE_IS_VSTR);
          if (ret & PYEXEC_FORCED_EXIT) {
              return ret;
          }
      }
  }
  
  #endif // MICROPY_REPL_EVENT_DRIVEN
  #endif // MICROPY_ENABLE_COMPILER
  
  int pyexec_file(const char *filename) {
      return parse_compile_execute(filename, MP_PARSE_FILE_INPUT, EXEC_FLAG_SOURCE_IS_FILENAME);
  }
  
  int pyexec_file_if_exists(const char *filename) {
      #if MICROPY_MODULE_FROZEN
      if (mp_frozen_stat(filename) == MP_IMPORT_STAT_FILE) {
          return pyexec_frozen_module(filename);
      }
      #endif
      if (mp_import_stat(filename) != MP_IMPORT_STAT_FILE) {
          return 1; // success (no file is the same as an empty file executing without fail)
      }
      return pyexec_file(filename);
  }
  
  #if MICROPY_MODULE_FROZEN
  int pyexec_frozen_module(const char *name) {
      void *frozen_data;
      int frozen_type = mp_find_frozen_module(name, strlen(name), &frozen_data);
  
      switch (frozen_type) {
          #if MICROPY_MODULE_FROZEN_STR
          case MP_FROZEN_STR:
              return parse_compile_execute(frozen_data, MP_PARSE_FILE_INPUT, 0);
          #endif
  
          #if MICROPY_MODULE_FROZEN_MPY
          case MP_FROZEN_MPY:
              return parse_compile_execute(frozen_data, MP_PARSE_FILE_INPUT, EXEC_FLAG_SOURCE_IS_RAW_CODE);
          #endif
  
          default:
              printf("could not find module '%s'\n", name);
              return false;
      }
  }
  #endif
  
  #if MICROPY_REPL_INFO
  mp_obj_t pyb_set_repl_info(mp_obj_t o_value) {
      repl_display_debugging_info = mp_obj_get_int(o_value);
      return mp_const_none;
  }
  MP_DEFINE_CONST_FUN_OBJ_1(pyb_set_repl_info_obj, pyb_set_repl_info);
  #endif
  