Annotation of GNUtools/cc/bi-lexer.c, revision 1.1

1.1     ! root        1: /* Lexer for scanner of bytecode definition file.
        !             2:    Copyright (C) 1993 Free Software Foundation, Inc.
        !             3: 
        !             4: This file is part of GNU CC.
        !             5: 
        !             6: GNU CC is free software; you can redistribute it and/or modify
        !             7: it under the terms of the GNU General Public License as published by
        !             8: the Free Software Foundation; either version 2, or (at your option)
        !             9: any later version.
        !            10: 
        !            11: GNU CC is distributed in the hope that it will be useful,
        !            12: but WITHOUT ANY WARRANTY; without even the implied warranty of
        !            13: MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
        !            14: GNU General Public License for more details.
        !            15: 
        !            16: You should have received a copy of the GNU General Public License
        !            17: along with GNU CC; see the file COPYING.  If not, write to
        !            18: the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.  */
        !            19: 
        !            20: #include <stdio.h>
        !            21: #include "hconfig.h"
        !            22: #include "bi-parser.h"
        !            23: 
        !            24: /* Current read buffer and point */
        !            25: static char *buffer = NULL;
        !            26: static char *inpoint = NULL;
        !            27: 
        !            28: 
        !            29: /* Safely allocate NBYTES bytes of memory. Reuturns pointer to block of
        !            30:    memory. */
        !            31: 
        !            32: static char *
        !            33: xmalloc (nbytes)
        !            34:      int nbytes;
        !            35: {
        !            36:   char *tmp = (char *) malloc (nbytes);
        !            37: 
        !            38:   if (!tmp)
        !            39:     {
        !            40:       fprintf (stderr, "can't allocate %d bytes (out of virtual memory)\n", nbytes);
        !            41:       exit (FATAL_EXIT_CODE);
        !            42:     }
        !            43: 
        !            44:   return tmp;
        !            45: }
        !            46: 
        !            47: 
        !            48: /* Safely reallocate BLOCK so its size becomes NBYTES.
        !            49:    The block returned may be different from the one supplied. */
        !            50: 
        !            51: static char *
        !            52: xrealloc (block, nbytes)
        !            53:      char *block;
        !            54:      int nbytes;
        !            55: {
        !            56:   char *tmp = (block
        !            57:               ? (char *) realloc (block, nbytes)
        !            58:               : (char *) malloc (nbytes));
        !            59: 
        !            60:   if (!tmp)
        !            61:     {
        !            62:       fprintf (stderr, "can't reallocate %d bytes (out of virtual memory)\n", nbytes);
        !            63:       exit (FATAL_EXIT_CODE);
        !            64:     }
        !            65: 
        !            66:   return tmp;
        !            67: }
        !            68: 
        !            69: 
        !            70: /* Scan for string token on standard input.  A string is, for our
        !            71:    purposes here, a sequence of characters that starts with the regexp
        !            72:    ``[^ #\t\n(),]'' and is then followed by the regexp ``[^#(),]*''. Any
        !            73:    character is accepted if preceded by a backslash, "\\".  It is assumed
        !            74:    that the first character has already been checked by the main loop. */
        !            75: 
        !            76: static char *
        !            77: scan_string ()
        !            78: {
        !            79:   char *buffer = NULL;
        !            80:   char *point = NULL;
        !            81:   int buffer_size = 0;
        !            82:   int c;
        !            83: 
        !            84:   while ((c = getc (stdin)) != EOF
        !            85:         && c != '#' && c != '(' && c != ')' && c != ',')
        !            86:     {
        !            87:       /* Extend buffer, if necessary (minus two so there's room for the NUL
        !            88:         trailer as well as another character if this one is a backslash).  */
        !            89:       if (!buffer_size || (point - buffer >= buffer_size-2))
        !            90:        {
        !            91:          int previous_point_index = point - buffer;
        !            92: 
        !            93:          buffer_size = (!buffer_size ? 32 : buffer_size * 2);
        !            94:          if (!buffer)
        !            95:            buffer = xmalloc (buffer_size);
        !            96:          else
        !            97:            buffer = xrealloc (buffer, buffer_size);
        !            98:          
        !            99:          point = buffer + previous_point_index;
        !           100:        }
        !           101:       *point++ = c & 0xff;
        !           102: 
        !           103:       if (c == '\\')
        !           104:        {
        !           105:          c = getc (stdin);
        !           106: 
        !           107:          /* Catch special case: backslash at end of file */
        !           108:          if (c == EOF)
        !           109:            break;
        !           110: 
        !           111:          *point++ = c;
        !           112:        }
        !           113:     }
        !           114:   *point = 0;
        !           115: 
        !           116:   if (c != EOF)
        !           117:     ungetc (c, stdin);
        !           118: 
        !           119:   return buffer;
        !           120: }
        !           121: 
        !           122: 
        !           123: int
        !           124: yylex ()
        !           125: {
        !           126:   int c;
        !           127:   char *token;
        !           128: 
        !           129: 
        !           130:   /* First char determines what token we're looking at */
        !           131:   for (;;)
        !           132:     {
        !           133:       c = getc (stdin);
        !           134: 
        !           135:       switch (c)
        !           136:        {
        !           137:        case EOF:
        !           138:          return 0;
        !           139:          
        !           140:        case ' ':
        !           141:        case '\t':
        !           142:        case '\n':
        !           143:          /* Ignore whitespace */
        !           144:          continue;
        !           145:          
        !           146:        case '#':
        !           147:          /* Comments advance to next line */
        !           148:          while ((c = getc (stdin)) != '\n' && c != EOF);
        !           149:          continue;
        !           150:          
        !           151:        default:
        !           152:          if (c != '(' && c != ')' && c != '\\' && c != ',')
        !           153:            {
        !           154:              ungetc (c, stdin);
        !           155:              yylval.string = scan_string ();
        !           156: 
        !           157:              /* Check if string is "define_operator"; if so, return
        !           158:                 a DEFOP token instead.  */
        !           159:              if (!strcmp (yylval.string, "define_operator"))
        !           160:                {
        !           161:                  free (yylval.string);
        !           162:                  yylval.string = 0;
        !           163:                  return DEFOP;
        !           164:                }
        !           165:              return STRING;
        !           166:            }
        !           167:          return c & 0xff;
        !           168:        }
        !           169:     }
        !           170: }

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