| 1 | /* input_file.c - Deal with Input Files - |
| 2 | Copyright (C) 1987, 90, 91, 92, 93, 94, 95, 98, 1999 |
| 3 | Free Software Foundation, Inc. |
| 4 | |
| 5 | This file is part of GAS, the GNU Assembler. |
| 6 | |
| 7 | GAS is free software; you can redistribute it and/or modify |
| 8 | it under the terms of the GNU General Public License as published by |
| 9 | the Free Software Foundation; either version 2, or (at your option) |
| 10 | any later version. |
| 11 | |
| 12 | GAS is distributed in the hope that it will be useful, |
| 13 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 15 | GNU General Public License for more details. |
| 16 | |
| 17 | You should have received a copy of the GNU General Public License |
| 18 | along with GAS; see the file COPYING. If not, write to the Free |
| 19 | Software Foundation, 59 Temple Place - Suite 330, Boston, MA |
| 20 | 02111-1307, USA. */ |
| 21 | |
| 22 | /* |
| 23 | * Confines all details of reading source bytes to this module. |
| 24 | * All O/S specific crocks should live here. |
| 25 | * What we lose in "efficiency" we gain in modularity. |
| 26 | * Note we don't need to #include the "as.h" file. No common coupling! |
| 27 | */ |
| 28 | |
| 29 | #include <stdio.h> |
| 30 | #include <string.h> |
| 31 | |
| 32 | #include "as.h" |
| 33 | #include "input-file.h" |
| 34 | |
| 35 | static int input_file_get PARAMS ((char *, int)); |
| 36 | |
| 37 | /* This variable is non-zero if the file currently being read should be |
| 38 | preprocessed by app. It is zero if the file can be read straight in. |
| 39 | */ |
| 40 | int preprocess = 0; |
| 41 | |
| 42 | /* |
| 43 | * This code opens a file, then delivers BUFFER_SIZE character |
| 44 | * chunks of the file on demand. |
| 45 | * BUFFER_SIZE is supposed to be a number chosen for speed. |
| 46 | * The caller only asks once what BUFFER_SIZE is, and asks before |
| 47 | * the nature of the input files (if any) is known. |
| 48 | */ |
| 49 | |
| 50 | #define BUFFER_SIZE (32 * 1024) |
| 51 | |
| 52 | /* |
| 53 | * We use static data: the data area is not sharable. |
| 54 | */ |
| 55 | |
| 56 | static FILE *f_in; |
| 57 | static char *file_name; |
| 58 | |
| 59 | /* Struct for saving the state of this module for file includes. */ |
| 60 | struct saved_file |
| 61 | { |
| 62 | FILE *f_in; |
| 63 | char *file_name; |
| 64 | int preprocess; |
| 65 | char *app_save; |
| 66 | }; |
| 67 | \f |
| 68 | /* These hooks accomodate most operating systems. */ |
| 69 | |
| 70 | void |
| 71 | input_file_begin () |
| 72 | { |
| 73 | f_in = (FILE *) 0; |
| 74 | } |
| 75 | |
| 76 | void |
| 77 | input_file_end () |
| 78 | { |
| 79 | } |
| 80 | |
| 81 | /* Return BUFFER_SIZE. */ |
| 82 | unsigned int |
| 83 | input_file_buffer_size () |
| 84 | { |
| 85 | return (BUFFER_SIZE); |
| 86 | } |
| 87 | |
| 88 | int |
| 89 | input_file_is_open () |
| 90 | { |
| 91 | return f_in != (FILE *) 0; |
| 92 | } |
| 93 | |
| 94 | /* Push the state of our input, returning a pointer to saved info that |
| 95 | can be restored with input_file_pop (). */ |
| 96 | char * |
| 97 | input_file_push () |
| 98 | { |
| 99 | register struct saved_file *saved; |
| 100 | |
| 101 | saved = (struct saved_file *) xmalloc (sizeof *saved); |
| 102 | |
| 103 | saved->f_in = f_in; |
| 104 | saved->file_name = file_name; |
| 105 | saved->preprocess = preprocess; |
| 106 | if (preprocess) |
| 107 | saved->app_save = app_push (); |
| 108 | |
| 109 | input_file_begin (); /* Initialize for new file */ |
| 110 | |
| 111 | return (char *) saved; |
| 112 | } |
| 113 | |
| 114 | void |
| 115 | input_file_pop (arg) |
| 116 | char *arg; |
| 117 | { |
| 118 | register struct saved_file *saved = (struct saved_file *) arg; |
| 119 | |
| 120 | input_file_end (); /* Close out old file */ |
| 121 | |
| 122 | f_in = saved->f_in; |
| 123 | file_name = saved->file_name; |
| 124 | preprocess = saved->preprocess; |
| 125 | if (preprocess) |
| 126 | app_pop (saved->app_save); |
| 127 | |
| 128 | free (arg); |
| 129 | } |
| 130 | \f |
| 131 | void |
| 132 | input_file_open (filename, pre) |
| 133 | char *filename; /* "" means use stdin. Must not be 0. */ |
| 134 | int pre; |
| 135 | { |
| 136 | int c; |
| 137 | char buf[80]; |
| 138 | |
| 139 | preprocess = pre; |
| 140 | |
| 141 | assert (filename != 0); /* Filename may not be NULL. */ |
| 142 | if (filename[0]) |
| 143 | { /* We have a file name. Suck it and see. */ |
| 144 | f_in = fopen (filename, "r"); |
| 145 | file_name = filename; |
| 146 | } |
| 147 | else |
| 148 | { /* use stdin for the input file. */ |
| 149 | f_in = stdin; |
| 150 | file_name = _("{standard input}"); /* For error messages. */ |
| 151 | } |
| 152 | if (f_in == (FILE *) 0) |
| 153 | { |
| 154 | as_bad (_("Can't open %s for reading."), file_name); |
| 155 | as_perror ("%s", file_name); |
| 156 | return; |
| 157 | } |
| 158 | |
| 159 | c = getc (f_in); |
| 160 | if (c == '#') |
| 161 | { /* Begins with comment, may not want to preprocess */ |
| 162 | c = getc (f_in); |
| 163 | if (c == 'N') |
| 164 | { |
| 165 | fgets (buf, 80, f_in); |
| 166 | if (!strcmp (buf, "O_APP\n")) |
| 167 | preprocess = 0; |
| 168 | if (!strchr (buf, '\n')) |
| 169 | ungetc ('#', f_in); /* It was longer */ |
| 170 | else |
| 171 | ungetc ('\n', f_in); |
| 172 | } |
| 173 | else if (c == '\n') |
| 174 | ungetc ('\n', f_in); |
| 175 | else |
| 176 | ungetc ('#', f_in); |
| 177 | } |
| 178 | else |
| 179 | ungetc (c, f_in); |
| 180 | } |
| 181 | |
| 182 | /* Close input file. */ |
| 183 | void |
| 184 | input_file_close () |
| 185 | { |
| 186 | if (f_in != NULL) |
| 187 | { |
| 188 | fclose (f_in); |
| 189 | } /* don't close a null file pointer */ |
| 190 | f_in = 0; |
| 191 | } /* input_file_close() */ |
| 192 | |
| 193 | /* This function is passed to do_scrub_chars. */ |
| 194 | |
| 195 | static int |
| 196 | input_file_get (buf, buflen) |
| 197 | char *buf; |
| 198 | int buflen; |
| 199 | { |
| 200 | int size; |
| 201 | |
| 202 | size = fread (buf, sizeof (char), buflen, f_in); |
| 203 | if (size < 0) |
| 204 | { |
| 205 | as_perror (_("Can't read from %s"), file_name); |
| 206 | size = 0; |
| 207 | } |
| 208 | return size; |
| 209 | } |
| 210 | |
| 211 | /* Read a buffer from the input file. */ |
| 212 | |
| 213 | char * |
| 214 | input_file_give_next_buffer (where) |
| 215 | char *where; /* Where to place 1st character of new buffer. */ |
| 216 | { |
| 217 | char *return_value; /* -> Last char of what we read, + 1. */ |
| 218 | register int size; |
| 219 | |
| 220 | if (f_in == (FILE *) 0) |
| 221 | return 0; |
| 222 | /* |
| 223 | * fflush (stdin); could be done here if you want to synchronise |
| 224 | * stdin and stdout, for the case where our input file is stdin. |
| 225 | * Since the assembler shouldn't do any output to stdout, we |
| 226 | * don't bother to synch output and input. |
| 227 | */ |
| 228 | if (preprocess) |
| 229 | size = do_scrub_chars (input_file_get, where, BUFFER_SIZE); |
| 230 | else |
| 231 | size = fread (where, sizeof (char), BUFFER_SIZE, f_in); |
| 232 | if (size < 0) |
| 233 | { |
| 234 | as_perror (_("Can't read from %s"), file_name); |
| 235 | size = 0; |
| 236 | } |
| 237 | if (size) |
| 238 | return_value = where + size; |
| 239 | else |
| 240 | { |
| 241 | if (fclose (f_in)) |
| 242 | as_perror (_("Can't close %s"), file_name); |
| 243 | f_in = (FILE *) 0; |
| 244 | return_value = 0; |
| 245 | } |
| 246 | return (return_value); |
| 247 | } |
| 248 | |
| 249 | /* end of input-file.c */ |