tok.c

   1 #include <ctype.h>
   2 #include <unistd.h>
   3 #include <string.h>
   4 #include "tok.h"
   5
   6 static char buf[BUFSIZE];
   7 static int len;
   8 static int cur;
   9 static char name[NAMELEN];
  10 static int next;
  11
  12 static struct {
  13         char *name;
  14         unsigned id;
  15 } kwds[] = {
  16         {"void", TOK_VOID},
  17         {"static", TOK_STATIC},
  18         {"return", TOK_RETURN},
  19         {"unsigned", TOK_UNSIGNED},
  20         {"signed", TOK_SIGNED},
  21         {"short", TOK_SHORT},
  22         {"long", TOK_LONG},
  23         {"int", TOK_INT},
  24         {"char", TOK_CHAR},
  25         {"struct", TOK_STRUCT},
  26         {"enum", TOK_ENUM},
  27         {"if", TOK_IF},
  28         {"else", TOK_ELSE},
  29         {"for", TOK_FOR},
  30         {"while", TOK_WHILE},
  31         {"do", TOK_DO},
  32         {"switch", TOK_SWITCH},
  33         {"case", TOK_CASE},
  34         {"sizeof", TOK_SIZEOF},
  35 };
  36
  37 static char *tok3[] = {
  38         "<<", ">>", "++", "--", "<<=", ">>=", "...", "+=", "-=", "*=", "/=",
  39         "%=", "|=", "&=", "^=", "&&", "||", "==", "!=", "<=", ">="
  40 };
  41
  42 static int get_tok3(int num)
  43 {
  44         int i;
  45         for (i = 0; i < ARRAY_SIZE(tok3); i++)
  46                 if (num == TOK3(tok3[i]))
  47                         return num;
  48         return 0;
  49 }
  50
  51 static int id_char(int c)
  52 {
  53         return isalnum(c) || c == '_';
  54 }
  55
  56 int tok_get(void)
  57 {
  58         int num;
  59         if (next != -1) {
  60                 int tok = next;
  61                 next = -1;
  62                 return tok;
  63         }
  64         while (cur < len && isspace(buf[cur]))
  65                 cur++;
  66         if (cur == len)
  67                 return TOK_EOF;
  68         if (isdigit(buf[cur])) {
  69                 char *s = name;
  70                 while (cur < len && isdigit(buf[cur]))
  71                         *s++ = buf[cur++];
  72                 *s = '\0';
  73                 return TOK_NUM;
  74         }
  75         if (id_char(buf[cur])) {
  76                 char *s = name;
  77                 int i;
  78                 while (cur < len && id_char(buf[cur]))
  79                         *s++ = buf[cur++];
  80                 *s = '\0';
  81                 for (i = 0; i < ARRAY_SIZE(kwds); i++)
  82                         if (!strcmp(kwds[i].name, name))
  83                                 return kwds[i].id;
  84                 return TOK_NAME;
  85         }
  86         if ((num = get_tok3(TOK3(buf + cur)))) {
  87                 cur += 3;
  88                 return num;
  89         }
  90         if ((num = get_tok3(TOK2(buf + cur)))) {
  91                 cur += 2;
  92                 return num;
  93         }
  94         if (strchr(";,{}()[]<>*&!=+-/%?:|^", buf[cur]))
  95                 return buf[cur++];
  96         return -1;
  97 }
  98
  99 int tok_see(void)
 100 {
 101         if (next == -1)
 102                 next = tok_get();
 103         return next;
 104 }
 105
 106 void tok_init(int fd)
 107 {
 108         int n = 0;
 109         while ((n = read(fd, buf + len, sizeof(buf) - len)) > 0)
 110                 len += n;
 111         next = -1;
 112 }
 113
 114 char *tok_id(void)
 115 {
 116         return name;
 117 }