Diff: main.cpp

Revision:

0:e7eb8eab3aa9

diff -r 000000000000 -r e7eb8eab3aa9 main.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Wed Mar 25 17:38:21 2015 +0000
@@ -0,0 +1,515 @@
+/*
+** mirb - Embeddable Interactive Ruby Shell
+**
+** This program takes code from the user in
+** an interactive way and executes it
+** immediately. It's a REPL...
+*/
+
+#include "mbed.h"
+ 
+Serial pc(USBTX, USBRX);
+
+#include <stdlib.h>
+#include <string.h>
+#include <stdio.h>
+#include <ctype.h>
+
+#ifdef ENABLE_READLINE
+#include <readline/readline.h>
+#include <readline/history.h>
+#define MIRB_ADD_HISTORY(line) add_history(line)
+#define MIRB_READLINE(ch) readline(ch)
+#define MIRB_WRITE_HISTORY(path) write_history(path)
+#define MIRB_READ_HISTORY(path) read_history(path)
+#define MIRB_USING_HISTORY() using_history()
+#elif defined(ENABLE_LINENOISE)
+#define ENABLE_READLINE
+#include <linenoise.h>
+#define MIRB_ADD_HISTORY(line) linenoiseHistoryAdd(line)
+#define MIRB_READLINE(ch) linenoise(ch)
+#define MIRB_WRITE_HISTORY(path) linenoiseHistorySave(path)
+#define MIRB_READ_HISTORY(path) linenoiseHistoryLoad(history_path)
+#define MIRB_USING_HISTORY()
+#endif
+
+#include "mruby.h"
+#include "mruby/array.h"
+#include "mruby/proc.h"
+#include "mruby/compile.h"
+#include "mruby/string.h"
+
+#ifdef ENABLE_READLINE
+
+static const char history_file_name[] = ".mirb_history";
+
+static char *
+get_history_path(mrb_state *mrb)
+{
+  char *path = NULL;
+  const char *home = getenv("HOME");
+
+#ifdef _WIN32
+  if (home != NULL) {
+    home = getenv("USERPROFILE");
+  }
+#endif
+
+  if (home != NULL) {
+    int len = snprintf(NULL, 0, "%s/%s", home, history_file_name);
+    if (len >= 0) {
+      size_t size = len + 1;
+      path = (char *)mrb_malloc_simple(mrb, size);
+      if (path != NULL) {
+        int n = snprintf(path, size, "%s/%s", home, history_file_name);
+        if (n != len) {
+          mrb_free(mrb, path);
+          path = NULL;
+        }
+      }
+    }
+  }
+
+  return path;
+}
+
+#endif
+
+static void
+p(mrb_state *mrb, mrb_value obj, int prompt)
+{
+  obj = mrb_funcall(mrb, obj, "inspect", 0);
+  if (prompt) {
+    if (!mrb->exc) {
+      pc.printf(" => ");
+    }
+    else {
+      obj = mrb_funcall(mrb, mrb_obj_value(mrb->exc), "inspect", 0);
+    }
+  }
+  fwrite(RSTRING_PTR(obj), RSTRING_LEN(obj), 1, stdout);
+  putc('\n', stdout);
+}
+
+/* Guess if the user might want to enter more
+ * or if he wants an evaluation of his code now */
+static mrb_bool
+is_code_block_open(struct mrb_parser_state *parser)
+{
+  mrb_bool code_block_open = FALSE;
+
+  /* check for heredoc */
+  if (parser->parsing_heredoc != NULL) return TRUE;
+  if (parser->heredoc_end_now) {
+    parser->heredoc_end_now = FALSE;
+    return FALSE;
+  }
+
+  /* check for unterminated string */
+  if (parser->lex_strterm) return TRUE;
+
+  /* check if parser error are available */
+  if (0 < parser->nerr) {
+    const char unexpected_end[] = "syntax error, unexpected $end";
+    const char *message = parser->error_buffer[0].message;
+
+    /* a parser error occur, we have to check if */
+    /* we need to read one more line or if there is */
+    /* a different issue which we have to show to */
+    /* the user */
+
+    if (strncmp(message, unexpected_end, sizeof(unexpected_end) - 1) == 0) {
+      code_block_open = TRUE;
+    }
+    else if (strcmp(message, "syntax error, unexpected keyword_end") == 0) {
+      code_block_open = FALSE;
+    }
+    else if (strcmp(message, "syntax error, unexpected tREGEXP_BEG") == 0) {
+      code_block_open = FALSE;
+    }
+    return code_block_open;
+  }
+
+  switch (parser->lstate) {
+
+  /* all states which need more code */
+
+  case EXPR_BEG:
+    /* beginning of a statement, */
+    /* that means previous line ended */
+    code_block_open = FALSE;
+    break;
+  case EXPR_DOT:
+    /* a message dot was the last token, */
+    /* there has to come more */
+    code_block_open = TRUE;
+    break;
+  case EXPR_CLASS:
+    /* a class keyword is not enough! */
+    /* we need also a name of the class */
+    code_block_open = TRUE;
+    break;
+  case EXPR_FNAME:
+    /* a method name is necessary */
+    code_block_open = TRUE;
+    break;
+  case EXPR_VALUE:
+    /* if, elsif, etc. without condition */
+    code_block_open = TRUE;
+    break;
+
+  /* now all the states which are closed */
+
+  case EXPR_ARG:
+    /* an argument is the last token */
+    code_block_open = FALSE;
+    break;
+
+  /* all states which are unsure */
+
+  case EXPR_CMDARG:
+    break;
+  case EXPR_END:
+    /* an expression was ended */
+    break;
+  case EXPR_ENDARG:
+    /* closing parenthese */
+    break;
+  case EXPR_ENDFN:
+    /* definition end */
+    break;
+  case EXPR_MID:
+    /* jump keyword like break, return, ... */
+    break;
+  case EXPR_MAX_STATE:
+    /* don't know what to do with this token */
+    break;
+  default:
+    /* this state is unexpected! */
+    break;
+  }
+
+  return code_block_open;
+}
+
+
+#if defined(__cplusplus)
+extern "C" {
+#endif
+void mrb_show_version(mrb_state *);
+void mrb_show_copyright(mrb_state *);
+#if defined(__cplusplus)
+}
+#endif
+
+struct _args {
+  mrb_bool verbose      : 1;
+  int argc;
+  char** argv;
+};
+
+static void
+usage(const char *name)
+{
+  static const char *const usage_msg[] = {
+  "switches:",
+  "-v           print version number, then run in verbose mode",
+  "--verbose    run in verbose mode",
+  "--version    print the version",
+  "--copyright  print the copyright",
+  NULL
+  };
+  const char *const *p = usage_msg;
+
+  pc.printf("Usage: %s [switches]\n", name);
+  while (*p)
+    pc.printf("  %s\n", *p++);
+}
+
+static int
+parse_args(mrb_state *mrb, int argc, char **argv, struct _args *args)
+{
+  static const struct _args args_zero = { 0 };
+
+  *args = args_zero;
+
+  for (argc--,argv++; argc > 0; argc--,argv++) {
+    char *item;
+    if (argv[0][0] != '-') break;
+
+    item = argv[0] + 1;
+    switch (*item++) {
+    case 'v':
+      if (!args->verbose) mrb_show_version(mrb);
+      args->verbose = TRUE;
+      break;
+    case '-':
+      if (strcmp((*argv) + 2, "version") == 0) {
+        mrb_show_version(mrb);
+        exit(EXIT_SUCCESS);
+      }
+      else if (strcmp((*argv) + 2, "verbose") == 0) {
+        args->verbose = TRUE;
+        break;
+      }
+      else if (strcmp((*argv) + 2, "copyright") == 0) {
+        mrb_show_copyright(mrb);
+        exit(EXIT_SUCCESS);
+      }
+    default:
+      return EXIT_FAILURE;
+    }
+  }
+  return EXIT_SUCCESS;
+}
+
+static void
+cleanup(mrb_state *mrb, struct _args *args)
+{
+  mrb_close(mrb);
+}
+
+/* Print a short remark for the user */
+static void
+print_hint(void)
+{
+  pc.printf("mirb - Embeddable Interactive Ruby Shell\n\n");
+}
+
+#ifndef ENABLE_READLINE
+/* Print the command line prompt of the REPL */
+static void
+print_cmdline(int code_block_open)
+{
+  if (code_block_open) {
+    pc.printf("* ");
+  }
+  else {
+    pc.printf("> ");
+  }
+}
+#endif
+
+#if defined(__cplusplus)
+extern "C" {
+#endif
+void mrb_codedump_all(mrb_state*, struct RProc*);
+#if defined(__cplusplus)
+}
+#endif
+
+static int
+check_keyword(const char *buf, const char *word)
+{
+  const char *p = buf;
+  size_t len = strlen(word);
+
+  /* skip preceding spaces */
+  while (*p && isspace((unsigned char)*p)) {
+    p++;
+  }
+  /* check keyword */
+  if (strncmp(p, word, len) != 0) {
+    return 0;
+  }
+  p += len;
+  /* skip trailing spaces */
+  while (*p) {
+    if (!isspace((unsigned char)*p)) return 0;
+    p++;
+  }
+  return 1;
+}
+
+char *mirb_argv[] = {
+    "mirb"
+};
+
+int
+main(void)
+{
+  int argc = 1;
+  char **argv = mirb_argv;
+  char ruby_code[1024] = { 0 };
+  char last_code_line[1024] = { 0 };
+#ifndef ENABLE_READLINE
+  int last_char;
+  int char_index;
+#else
+  char *history_path;
+#endif
+  mrbc_context *cxt;
+  struct mrb_parser_state *parser;
+  mrb_state *mrb;
+  mrb_value result;
+  struct _args args;
+  int n;
+  mrb_bool code_block_open = FALSE;
+  int ai;
+  unsigned int stack_keep = 0;
+
+  /* new interpreter instance */
+  mrb = mrb_open();
+  if (mrb == NULL) {
+    pc.printf("Invalid mrb interpreter, exiting mirb\n");
+    return EXIT_FAILURE;
+  }
+  mrb_define_global_const(mrb, "ARGV", mrb_ary_new_capa(mrb, 0));
+
+  n = parse_args(mrb, argc, argv, &args);
+  if (n == EXIT_FAILURE) {
+    cleanup(mrb, &args);
+    usage(argv[0]);
+    return n;
+  }
+
+#ifdef ENABLE_READLINE
+  history_path = get_history_path(mrb);
+  if (history_path == NULL) {
+    pc.printf("failed to get history path\n");
+    mrb_close(mrb);
+    return EXIT_FAILURE;
+  }
+
+  MIRB_USING_HISTORY();
+  MIRB_READ_HISTORY(history_path);
+#endif
+
+  print_hint();
+
+  cxt = mrbc_context_new(mrb);
+  cxt->capture_errors = TRUE;
+  cxt->lineno = 1;
+  mrbc_filename(mrb, cxt, "(mirb)");
+  if (args.verbose) cxt->dump_result = TRUE;
+
+  ai = mrb_gc_arena_save(mrb);
+
+  while (TRUE) {
+#ifndef ENABLE_READLINE
+    print_cmdline(code_block_open);
+
+    char_index = 0;
+    while ((last_char = pc.getc()) != '\n') {
+      pc.printf("%c", last_char);
+      if (last_char == EOF) break;
+      if (char_index > sizeof(last_code_line)-2) {
+        pc.printf("input string too long\n");
+        continue;
+      }
+      if (last_char == '\x08') {
+        if (char_index > 0) char_index--;
+        continue;
+      } else {
+        last_code_line[char_index++] = last_char;
+      }
+    }
+    pc.printf("\n");
+    
+    if (last_char == EOF) {
+      pc.printf("\n");
+      break;
+    }
+
+    last_code_line[char_index++] = '\n';
+    last_code_line[char_index] = '\0';
+#else
+    char* line = MIRB_READLINE(code_block_open ? "* " : "> ");
+    if (line == NULL) {
+      printf("\n");
+      break;
+    }
+    if (strlen(line) > sizeof(last_code_line)-2) {
+      pc.printf("input string too long\n");
+      continue;
+    }
+    strcpy(last_code_line, line);
+    strcat(last_code_line, "\n");
+    MIRB_ADD_HISTORY(line);
+    free(line);
+#endif
+
+    if (code_block_open) {
+      if (strlen(ruby_code)+strlen(last_code_line) > sizeof(ruby_code)-1) {
+        pc.printf("concatenated input string too long\n");
+        continue;
+      }
+      strcat(ruby_code, last_code_line);
+    }
+    else {
+      if (check_keyword(last_code_line, "quit") || check_keyword(last_code_line, "exit")) {
+        break;
+      }
+      strcpy(ruby_code, last_code_line);
+    }
+
+    /* parse code */
+    parser = mrb_parser_new(mrb);
+    if (parser == NULL) {
+      pc.printf("create parser state error\n");
+      break;
+    }
+    parser->s = ruby_code;
+    parser->send = ruby_code + strlen(ruby_code);
+    parser->lineno = cxt->lineno;
+    mrb_parser_parse(parser, cxt);
+    code_block_open = is_code_block_open(parser);
+
+    if (code_block_open) {
+      /* no evaluation of code */
+    }
+    else {
+      if (0 < parser->nerr) {
+        /* syntax error */
+        pc.printf("line %d: %s\n", parser->error_buffer[0].lineno, parser->error_buffer[0].message);
+      }
+      else {
+        /* generate bytecode */
+        struct RProc *proc = mrb_generate_code(mrb, parser);
+        if (proc == NULL) {
+          pc.printf("codegen error\n");
+          mrb_parser_free(parser);
+          break;
+        }
+
+        if (args.verbose) {
+          mrb_codedump_all(mrb, proc);
+        }
+        /* pass a proc for evaulation */
+        /* evaluate the bytecode */
+        result = mrb_context_run(mrb,
+            proc,
+            mrb_top_self(mrb),
+            stack_keep);
+        stack_keep = proc->body.irep->nlocals;
+        /* did an exception occur? */
+        if (mrb->exc) {
+          p(mrb, mrb_obj_value(mrb->exc), 0);
+          mrb->exc = 0;
+        }
+        else {
+          /* no */
+          if (!mrb_respond_to(mrb, result, mrb_intern_lit(mrb, "inspect"))){
+            result = mrb_any_to_s(mrb, result);
+          }
+          p(mrb, result, 1);
+        }
+      }
+      ruby_code[0] = '\0';
+      last_code_line[0] = '\0';
+      mrb_gc_arena_restore(mrb, ai);
+    }
+    mrb_parser_free(parser);
+    cxt->lineno++;
+  }
+  
+#ifdef ENABLE_READLINE
+  MIRB_WRITE_HISTORY(history_path);
+  mrb_free(mrb, history_path);
+#endif
+
+  mrbc_context_free(mrb, cxt);
+  mrb_close(mrb);
+  
+  return 0;
+}