| 1 | /* input_file.c - Deal with Input Files - |
| 2 | Copyright 1987, 1990, 1991, 1992, 1993, 1994, 1995, 1999, 2000, 2001, |
| 3 | 2002, 2003, 2005, 2006, 2007, 2009, 2012 |
| 4 | Free Software Foundation, Inc. |
| 5 | |
| 6 | This file is part of GAS, the GNU Assembler. |
| 7 | |
| 8 | GAS is free software; you can redistribute it and/or modify |
| 9 | it under the terms of the GNU General Public License as published by |
| 10 | the Free Software Foundation; either version 3, or (at your option) |
| 11 | any later version. |
| 12 | |
| 13 | GAS is distributed in the hope that it will be useful, |
| 14 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 16 | GNU General Public License for more details. |
| 17 | |
| 18 | You should have received a copy of the GNU General Public License |
| 19 | along with GAS; see the file COPYING. If not, write to the Free |
| 20 | Software Foundation, 51 Franklin Street - Fifth Floor, Boston, MA |
| 21 | 02110-1301, USA. */ |
| 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 | #include "as.h" |
| 29 | #include "input-file.h" |
| 30 | #include "safe-ctype.h" |
| 31 | |
| 32 | /* This variable is non-zero if the file currently being read should be |
| 33 | preprocessed by app. It is zero if the file can be read straight in. */ |
| 34 | int preprocess = 0; |
| 35 | |
| 36 | /* This code opens a file, then delivers BUFFER_SIZE character |
| 37 | chunks of the file on demand. |
| 38 | BUFFER_SIZE is supposed to be a number chosen for speed. |
| 39 | The caller only asks once what BUFFER_SIZE is, and asks before |
| 40 | the nature of the input files (if any) is known. */ |
| 41 | |
| 42 | #define BUFFER_SIZE (32 * 1024) |
| 43 | |
| 44 | /* We use static data: the data area is not sharable. */ |
| 45 | |
| 46 | static FILE *f_in; |
| 47 | static char *file_name; |
| 48 | |
| 49 | /* Struct for saving the state of this module for file includes. */ |
| 50 | struct saved_file |
| 51 | { |
| 52 | FILE * f_in; |
| 53 | char * file_name; |
| 54 | int preprocess; |
| 55 | char * app_save; |
| 56 | }; |
| 57 | \f |
| 58 | /* These hooks accommodate most operating systems. */ |
| 59 | |
| 60 | void |
| 61 | input_file_begin (void) |
| 62 | { |
| 63 | f_in = (FILE *) 0; |
| 64 | } |
| 65 | |
| 66 | void |
| 67 | input_file_end (void) |
| 68 | { |
| 69 | } |
| 70 | |
| 71 | /* Return BUFFER_SIZE. */ |
| 72 | size_t |
| 73 | input_file_buffer_size (void) |
| 74 | { |
| 75 | return (BUFFER_SIZE); |
| 76 | } |
| 77 | |
| 78 | /* Push the state of our input, returning a pointer to saved info that |
| 79 | can be restored with input_file_pop (). */ |
| 80 | |
| 81 | char * |
| 82 | input_file_push (void) |
| 83 | { |
| 84 | register struct saved_file *saved; |
| 85 | |
| 86 | saved = (struct saved_file *) xmalloc (sizeof *saved); |
| 87 | |
| 88 | saved->f_in = f_in; |
| 89 | saved->file_name = file_name; |
| 90 | saved->preprocess = preprocess; |
| 91 | if (preprocess) |
| 92 | saved->app_save = app_push (); |
| 93 | |
| 94 | /* Initialize for new file. */ |
| 95 | input_file_begin (); |
| 96 | |
| 97 | return (char *) saved; |
| 98 | } |
| 99 | |
| 100 | void |
| 101 | input_file_pop (char *arg) |
| 102 | { |
| 103 | register struct saved_file *saved = (struct saved_file *) arg; |
| 104 | |
| 105 | input_file_end (); /* Close out old file. */ |
| 106 | |
| 107 | f_in = saved->f_in; |
| 108 | file_name = saved->file_name; |
| 109 | preprocess = saved->preprocess; |
| 110 | if (preprocess) |
| 111 | app_pop (saved->app_save); |
| 112 | |
| 113 | free (arg); |
| 114 | } |
| 115 | \f |
| 116 | void |
| 117 | input_file_open (char *filename, /* "" means use stdin. Must not be 0. */ |
| 118 | int pre) |
| 119 | { |
| 120 | int c; |
| 121 | char buf[80]; |
| 122 | |
| 123 | preprocess = pre; |
| 124 | |
| 125 | gas_assert (filename != 0); /* Filename may not be NULL. */ |
| 126 | if (filename[0]) |
| 127 | { |
| 128 | f_in = fopen (filename, FOPEN_RT); |
| 129 | file_name = filename; |
| 130 | } |
| 131 | else |
| 132 | { |
| 133 | /* Use stdin for the input file. */ |
| 134 | f_in = stdin; |
| 135 | /* For error messages. */ |
| 136 | file_name = _("{standard input}"); |
| 137 | } |
| 138 | |
| 139 | if (f_in == NULL) |
| 140 | { |
| 141 | as_bad (_("can't open %s for reading: %s"), |
| 142 | file_name, xstrerror (errno)); |
| 143 | return; |
| 144 | } |
| 145 | |
| 146 | c = getc (f_in); |
| 147 | |
| 148 | if (ferror (f_in)) |
| 149 | { |
| 150 | as_bad (_("can't read from %s: %s"), |
| 151 | file_name, xstrerror (errno)); |
| 152 | |
| 153 | fclose (f_in); |
| 154 | f_in = NULL; |
| 155 | return; |
| 156 | } |
| 157 | |
| 158 | /* Check for an empty input file. */ |
| 159 | if (feof (f_in)) |
| 160 | { |
| 161 | fclose (f_in); |
| 162 | f_in = NULL; |
| 163 | return; |
| 164 | } |
| 165 | gas_assert (c != EOF); |
| 166 | |
| 167 | if (c == '#') |
| 168 | { |
| 169 | /* Begins with comment, may not want to preprocess. */ |
| 170 | c = getc (f_in); |
| 171 | if (c == 'N') |
| 172 | { |
| 173 | if (fgets (buf, sizeof (buf), f_in) |
| 174 | && !strncmp (buf, "O_APP", 5) && ISSPACE (buf[5])) |
| 175 | preprocess = 0; |
| 176 | if (!strchr (buf, '\n')) |
| 177 | ungetc ('#', f_in); /* It was longer. */ |
| 178 | else |
| 179 | ungetc ('\n', f_in); |
| 180 | } |
| 181 | else if (c == 'A') |
| 182 | { |
| 183 | if (fgets (buf, sizeof (buf), f_in) |
| 184 | && !strncmp (buf, "PP", 2) && ISSPACE (buf[2])) |
| 185 | preprocess = 1; |
| 186 | if (!strchr (buf, '\n')) |
| 187 | ungetc ('#', f_in); |
| 188 | else |
| 189 | ungetc ('\n', f_in); |
| 190 | } |
| 191 | else if (c == '\n') |
| 192 | ungetc ('\n', f_in); |
| 193 | else |
| 194 | ungetc ('#', f_in); |
| 195 | } |
| 196 | else |
| 197 | ungetc (c, f_in); |
| 198 | } |
| 199 | |
| 200 | /* Close input file. */ |
| 201 | |
| 202 | void |
| 203 | input_file_close (void) |
| 204 | { |
| 205 | /* Don't close a null file pointer. */ |
| 206 | if (f_in != NULL) |
| 207 | fclose (f_in); |
| 208 | |
| 209 | f_in = 0; |
| 210 | } |
| 211 | |
| 212 | /* This function is passed to do_scrub_chars. */ |
| 213 | |
| 214 | static size_t |
| 215 | input_file_get (char *buf, size_t buflen) |
| 216 | { |
| 217 | size_t size; |
| 218 | |
| 219 | if (feof (f_in)) |
| 220 | return 0; |
| 221 | |
| 222 | size = fread (buf, sizeof (char), buflen, f_in); |
| 223 | if (ferror (f_in)) |
| 224 | as_bad (_("can't read from %s: %s"), file_name, xstrerror (errno)); |
| 225 | return size; |
| 226 | } |
| 227 | |
| 228 | /* Read a buffer from the input file. */ |
| 229 | |
| 230 | char * |
| 231 | input_file_give_next_buffer (char *where /* Where to place 1st character of new buffer. */) |
| 232 | { |
| 233 | char *return_value; /* -> Last char of what we read, + 1. */ |
| 234 | size_t size; |
| 235 | |
| 236 | if (f_in == (FILE *) 0) |
| 237 | return 0; |
| 238 | /* fflush (stdin); could be done here if you want to synchronise |
| 239 | stdin and stdout, for the case where our input file is stdin. |
| 240 | Since the assembler shouldn't do any output to stdout, we |
| 241 | don't bother to synch output and input. */ |
| 242 | if (preprocess) |
| 243 | size = do_scrub_chars (input_file_get, where, BUFFER_SIZE); |
| 244 | else |
| 245 | size = input_file_get (where, BUFFER_SIZE); |
| 246 | |
| 247 | if (size) |
| 248 | return_value = where + size; |
| 249 | else |
| 250 | { |
| 251 | if (fclose (f_in)) |
| 252 | as_warn (_("can't close %s: %s"), file_name, xstrerror (errno)); |
| 253 | |
| 254 | f_in = (FILE *) 0; |
| 255 | return_value = 0; |
| 256 | } |
| 257 | |
| 258 | return return_value; |
| 259 | } |