1 | /* Lexer for scanner of bytecode definition file. |
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2 | Copyright (C) 1993, 1995 Free Software Foundation, Inc. |
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3 | |
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4 | This file is part of GNU CC. |
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5 | |
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6 | GNU CC is free software; you can redistribute it and/or modify |
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7 | it under the terms of the GNU General Public License as published by |
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8 | the Free Software Foundation; either version 2, or (at your option) |
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9 | any later version. |
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10 | |
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11 | GNU CC is distributed in the hope that it will be useful, |
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12 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
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13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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14 | GNU General Public License for more details. |
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15 | |
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16 | You should have received a copy of the GNU General Public License |
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17 | along with GNU CC; see the file COPYING. If not, write to |
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18 | the Free Software Foundation, 59 Temple Place - Suite 330, |
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19 | Boston, MA 02111-1307, USA. */ |
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20 | |
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21 | #include <stdio.h> |
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22 | #include "hconfig.h" |
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23 | #include "bi-parser.h" |
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24 | |
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25 | |
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26 | /* Safely allocate NBYTES bytes of memory. Returns pointer to block of |
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27 | memory. */ |
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28 | |
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29 | static char * |
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30 | xmalloc (nbytes) |
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31 | int nbytes; |
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32 | { |
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33 | char *tmp = (char *) malloc (nbytes); |
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34 | |
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35 | if (!tmp) |
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36 | { |
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37 | fprintf (stderr, "can't allocate %d bytes (out of virtual memory)\n", nbytes); |
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38 | exit (FATAL_EXIT_CODE); |
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39 | } |
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40 | |
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41 | return tmp; |
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42 | } |
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43 | |
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44 | |
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45 | /* Safely reallocate BLOCK so its size becomes NBYTES. |
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46 | The block returned may be different from the one supplied. */ |
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47 | |
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48 | static char * |
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49 | xrealloc (block, nbytes) |
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50 | char *block; |
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51 | int nbytes; |
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52 | { |
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53 | char *tmp = (block |
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54 | ? (char *) realloc (block, nbytes) |
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55 | : (char *) malloc (nbytes)); |
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56 | |
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57 | if (!tmp) |
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58 | { |
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59 | fprintf (stderr, "can't reallocate %d bytes (out of virtual memory)\n", nbytes); |
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60 | exit (FATAL_EXIT_CODE); |
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61 | } |
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62 | |
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63 | return tmp; |
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64 | } |
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65 | |
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66 | |
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67 | /* Scan for string token on standard input. A string is, for our |
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68 | purposes here, a sequence of characters that starts with the regexp |
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69 | ``[^ #\t\n(),]'' and is then followed by the regexp ``[^#(),]*''. Any |
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70 | character is accepted if preceded by a backslash, "\\". It is assumed |
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71 | that the first character has already been checked by the main loop. */ |
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72 | |
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73 | static char * |
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74 | scan_string () |
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75 | { |
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76 | char *buffer = NULL; |
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77 | char *point = NULL; |
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78 | int buffer_size = 0; |
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79 | int c; |
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80 | |
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81 | while ((c = getc (stdin)) != EOF |
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82 | && c != '#' && c != '(' && c != ')' && c != ',') |
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83 | { |
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84 | /* Extend buffer, if necessary (minus two so there's room for the NUL |
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85 | trailer as well as another character if this one is a backslash). */ |
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86 | if (!buffer_size || (point - buffer >= buffer_size-2)) |
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87 | { |
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88 | int previous_point_index = point - buffer; |
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89 | |
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90 | buffer_size = (!buffer_size ? 32 : buffer_size * 2); |
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91 | if (!buffer) |
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92 | buffer = xmalloc (buffer_size); |
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93 | else |
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94 | buffer = xrealloc (buffer, buffer_size); |
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95 | |
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96 | point = buffer + previous_point_index; |
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97 | } |
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98 | *point++ = c & 0xff; |
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99 | |
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100 | if (c == '\\') |
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101 | { |
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102 | c = getc (stdin); |
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103 | |
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104 | /* Catch special case: backslash at end of file */ |
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105 | if (c == EOF) |
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106 | break; |
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107 | |
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108 | *point++ = c; |
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109 | } |
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110 | } |
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111 | *point = 0; |
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112 | |
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113 | if (c != EOF) |
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114 | ungetc (c, stdin); |
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115 | |
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116 | return buffer; |
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117 | } |
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118 | |
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119 | |
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120 | int |
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121 | yylex () |
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122 | { |
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123 | int c; |
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124 | char *token; |
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125 | |
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126 | |
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127 | /* First char determines what token we're looking at */ |
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128 | for (;;) |
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129 | { |
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130 | c = getc (stdin); |
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131 | |
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132 | switch (c) |
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133 | { |
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134 | case EOF: |
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135 | return 0; |
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136 | |
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137 | case ' ': |
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138 | case '\t': |
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139 | case '\n': |
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140 | /* Ignore whitespace */ |
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141 | continue; |
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142 | |
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143 | case '#': |
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144 | /* Comments advance to next line */ |
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145 | while ((c = getc (stdin)) != '\n' && c != EOF); |
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146 | continue; |
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147 | |
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148 | default: |
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149 | if (c != '(' && c != ')' && c != '\\' && c != ',') |
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150 | { |
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151 | ungetc (c, stdin); |
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152 | yylval.string = scan_string (); |
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153 | |
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154 | /* Check if string is "define_operator"; if so, return |
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155 | a DEFOP token instead. */ |
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156 | if (!strcmp (yylval.string, "define_operator")) |
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157 | { |
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158 | free (yylval.string); |
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159 | yylval.string = 0; |
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160 | return DEFOP; |
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161 | } |
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162 | return STRING; |
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163 | } |
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164 | return c & 0xff; |
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165 | } |
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166 | } |
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167 | } |
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