NJU_PA/nemu/src/monitor/sdb/sdb.c

/***************************************************************************************
* Copyright (c) 2014-2022 Zihao Yu, Nanjing University
*
* NEMU is licensed under Mulan PSL v2.
* You can use this software according to the terms and conditions of the Mulan PSL v2.
* You may obtain a copy of Mulan PSL v2 at:
*          http://license.coscl.org.cn/MulanPSL2
*
* THIS SOFTWARE IS PROVIDED ON AN "AS IS" BASIS, WITHOUT WARRANTIES OF ANY KIND,
* EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO NON-INFRINGEMENT,
* MERCHANTABILITY OR FIT FOR A PARTICULAR PURPOSE.
*
* See the Mulan PSL v2 for more details.
***************************************************************************************/

#include <isa.h>
#include <cpu/cpu.h>
#include <readline/readline.h>
#include <readline/history.h>
#include <memory/vaddr.h>
#include "sdb.h"

static int is_batch_mode = false;

void init_regex();
void init_wp_pool();

/* We use the `readline' library to provide more flexibility to read from stdin. */
static char* rl_gets() {
  static char *line_read = NULL;

  if (line_read) {
    free(line_read);
    line_read = NULL;
  }

  line_read = readline("(nemu) ");

  if (line_read && *line_read) {
    add_history(line_read);
  }

  return line_read;
}

/* print the help message, when name is NULL will print all of it */
static bool p_help(char *name);

static int cmd_c(char *args) {
  cpu_exec(UINT64_MAX);
  return 0;
}

static int cmd_q(char *args) {
  set_nemu_state(NEMU_END, 0, 0);
  return -1;
}

static int cmd_help(char *args);

static int cmd_si(char *args) {
  /* extract the first argument */
  char *arg = strtok(NULL, " ");
  if (arg == NULL) {
    arg = "1";
  }
  cpu_exec(atoi(arg));
  return 0;
}

static int cmd_info(char *args) {
  char *arg = strtok(NULL, " ");
  if (arg[0] == 'r') {
    isa_reg_display();
  } else if (arg[0] == 'w') {
    printf("Watchpoint:\n");
  } else {
    p_help("info");
  }
  return 0;
}

static int cmd_x(char *args) {
  char *arg0 = strtok(NULL, " ");
  char *arg1 = strtok(NULL, " ");
  if (arg0 == NULL || arg1 == NULL) {
    goto END;
  }

  vaddr_t addr = 0;
  if (!sscanf(arg1, FMT_PADDR, &addr)) {
    goto END;
  }

  size_t N = atoi(arg0);
  if (N <= 0) N = 1;

  for (size_t i = 0; i < N; i++) {
    printf(FMT_PADDR": "FMT_WORD"\n", addr, vaddr_read(addr, 4));
    addr += 4;
  }
  return 0;
END:
  p_help("x");
  return 0;
}

static int cmd_p(char *args) {
  bool success = false;
  expr(args, &success);
  return success;
}

static int cmd_w(char *args) { return 0; }

static int cmd_d(char *args) { return 0; }

static struct {
  const char *name;
  const char *description;
  int (*handler) (char *);
} cmd_table [] = {
  { "help", "Display information about all supported commands", cmd_help },
  { "c", "Continue the execution of the program", cmd_c },
  { "q", "Exit NEMU", cmd_q },
  { "si", "si [N]: To make a program pause after executing N (default 1) instructions", cmd_si },
  { "info", "info r: Display registers stats, info w: Display watch points value", cmd_info },
  { "x", "x N EXPR: To evaluate an expression EXPR and output the result as "\
         "a starting memory address in hexadecimal format, "\
         "followed by the next N consecutive 4-byte addresses in hexadecimal form", cmd_x },
  { "p", "p EXPR: To evaluate an expression EXPR and output the result", cmd_p },
  { "w", "w EXPR: To pause the program when the value of an expression EXPR changes, "\
        "you can create a monitoring loop that checks the value of EXPR at regular intervals. "\
        "When the value changes, the program will pause.", cmd_w },
  { "d", "d N: To remove a watchpoint with a specific index N", cmd_d },
  /* TODO: Add more commands */

};

#define NR_CMD ARRLEN(cmd_table)

static bool p_help(char *name) {
  for (int i = 0; i < NR_CMD; i ++) {
    if (name == NULL) {
      printf("%s - %s\n", cmd_table[i].name, cmd_table[i].description);
      continue;
    }
    if (strcmp(name, cmd_table[i].name) == 0) {
      printf("%s - %s\n", cmd_table[i].name, cmd_table[i].description);
      return true;
    }
  }
  return true ? name == NULL : false;
}

static int cmd_help(char *args) {
  /* extract the first argument */
  char *arg = strtok(NULL, " ");

  if (p_help(arg) == false) {
    printf("Unknown command '%s'\n", arg);
  }
  return 0;
}

void sdb_set_batch_mode() {
  is_batch_mode = true;
}

void sdb_mainloop() {
  if (is_batch_mode) {
    cmd_c(NULL);
    return;
  }

  for (char *str; (str = rl_gets()) != NULL; ) {
    char *str_end = str + strlen(str);

    /* extract the first token as the command */
    char *cmd = strtok(str, " ");
    if (cmd == NULL) { continue; }

    /* treat the remaining string as the arguments,
     * which may need further parsing
     */
    char *args = cmd + strlen(cmd) + 1;
    if (args >= str_end) {
      args = NULL;
    }

#ifdef CONFIG_DEVICE
    extern void sdl_clear_event_queue();
    sdl_clear_event_queue();
#endif

    int i;
    for (i = 0; i < NR_CMD; i ++) {
      if (strcmp(cmd, cmd_table[i].name) == 0) {
        if (cmd_table[i].handler(args) < 0) { return; }
        break;
      }
    }

    if (i == NR_CMD) { printf("Unknown command '%s'\n", cmd); }
  }
}

void init_sdb() {
  /* Compile the regular expressions. */
  init_regex();

  /* Initialize the watchpoint pool. */
  init_wp_pool();
}