Annotation of GNUtools/cc/bi-lexer.c, revision 1.1.1.1

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: }

unix.superglobalmegacorp.com

This archive runs on limited infrastructure. Preserving old code on modern bandwidth. Automated agents are requested to crawl responsibly.