1 /* input_file.c - Deal with Input Files - 2 Copyright 1987, 1990, 1991, 1992, 1993, 1994, 1995, 1999, 2000, 2001, 3 2002, 2003, 2005 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 2, 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 <stdio.h> 29 #include <string.h> 30 #include <errno.h> 31 #include "as.h" 32 #include "input-file.h" 33 #include "safe-ctype.h" 34 35 static int input_file_get (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 int preprocess = 0; 40 41 /* This code opens a file, then delivers BUFFER_SIZE character 42 chunks of the file on demand. 43 BUFFER_SIZE is supposed to be a number chosen for speed. 44 The caller only asks once what BUFFER_SIZE is, and asks before 45 the nature of the input files (if any) is known. */ 46 47 #define BUFFER_SIZE (32 * 1024) 48 49 /* We use static data: the data area is not sharable. */ 50 51 static FILE *f_in; 52 static char *file_name; 53 54 /* Struct for saving the state of this module for file includes. */ 55 struct saved_file 56 { 57 FILE * f_in; 58 char * file_name; 59 int preprocess; 60 char * app_save; 61 }; 62 63 /* These hooks accommodate most operating systems. */ 64 65 void 66 input_file_begin (void) 67 { 68 f_in = (FILE *) 0; 69 } 70 71 void 72 input_file_end (void) 73 { 74 } 75 76 /* Return BUFFER_SIZE. */ 77 unsigned int 78 input_file_buffer_size (void) 79 { 80 return (BUFFER_SIZE); 81 } 82 83 /* Push the state of our input, returning a pointer to saved info that 84 can be restored with input_file_pop (). */ 85 86 char * 87 input_file_push (void) 88 { 89 register struct saved_file *saved; 90 91 saved = (struct saved_file *) xmalloc (sizeof *saved); 92 93 saved->f_in = f_in; 94 saved->file_name = file_name; 95 saved->preprocess = preprocess; 96 if (preprocess) 97 saved->app_save = app_push (); 98 99 /* Initialize for new file. */ 100 input_file_begin (); 101 102 return (char *) saved; 103 } 104 105 void 106 input_file_pop (char *arg) 107 { 108 register struct saved_file *saved = (struct saved_file *) arg; 109 110 input_file_end (); /* Close out old file. */ 111 112 f_in = saved->f_in; 113 file_name = saved->file_name; 114 preprocess = saved->preprocess; 115 if (preprocess) 116 app_pop (saved->app_save); 117 118 free (arg); 119 } 120 121 void 122 input_file_open (char *filename, /* "" means use stdin. Must not be 0. */ 123 int pre) 124 { 125 int c; 126 char buf[80]; 127 128 preprocess = pre; 129 130 assert (filename != 0); /* Filename may not be NULL. */ 131 if (filename[0]) 132 { 133 f_in = fopen (filename, FOPEN_RT); 134 file_name = filename; 135 } 136 else 137 { 138 /* Use stdin for the input file. */ 139 f_in = stdin; 140 /* For error messages. */ 141 file_name = _("{standard input}"); 142 } 143 144 if (f_in == NULL) 145 { 146 bfd_set_error (bfd_error_system_call); 147 as_perror (_("Can't open %s for reading"), file_name); 148 return; 149 } 150 151 c = getc (f_in); 152 153 if (ferror (f_in)) 154 { 155 bfd_set_error (bfd_error_system_call); 156 as_perror (_("Can't open %s for reading"), file_name); 157 158 fclose (f_in); 159 f_in = NULL; 160 return; 161 } 162 163 if (c == '#') 164 { 165 /* Begins with comment, may not want to preprocess. */ 166 c = getc (f_in); 167 if (c == 'N') 168 { 169 fgets (buf, 80, f_in); 170 if (!strncmp (buf, "O_APP", 5) && ISSPACE (buf[5])) 171 preprocess = 0; 172 if (!strchr (buf, '\n')) 173 ungetc ('#', f_in); /* It was longer. */ 174 else 175 ungetc ('\n', f_in); 176 } 177 else if (c == 'A') 178 { 179 fgets (buf, 80, f_in); 180 if (!strncmp (buf, "PP", 2) && ISSPACE (buf[2])) 181 preprocess = 1; 182 if (!strchr (buf, '\n')) 183 ungetc ('#', f_in); 184 else 185 ungetc ('\n', f_in); 186 } 187 else if (c == '\n') 188 ungetc ('\n', f_in); 189 else 190 ungetc ('#', f_in); 191 } 192 else 193 ungetc (c, f_in); 194 } 195 196 /* Close input file. */ 197 198 void 199 input_file_close (void) 200 { 201 /* Don't close a null file pointer. */ 202 if (f_in != NULL) 203 fclose (f_in); 204 205 f_in = 0; 206 } 207 208 /* This function is passed to do_scrub_chars. */ 209 210 static int 211 input_file_get (char *buf, int buflen) 212 { 213 int size; 214 215 size = fread (buf, sizeof (char), buflen, f_in); 216 if (size < 0) 217 { 218 bfd_set_error (bfd_error_system_call); 219 as_perror (_("Can't read from %s"), file_name); 220 size = 0; 221 } 222 return size; 223 } 224 225 /* Read a buffer from the input file. */ 226 227 char * 228 input_file_give_next_buffer (char *where /* Where to place 1st character of new buffer. */) 229 { 230 char *return_value; /* -> Last char of what we read, + 1. */ 231 register int size; 232 233 if (f_in == (FILE *) 0) 234 return 0; 235 /* fflush (stdin); could be done here if you want to synchronise 236 stdin and stdout, for the case where our input file is stdin. 237 Since the assembler shouldn't do any output to stdout, we 238 don't bother to synch output and input. */ 239 if (preprocess) 240 size = do_scrub_chars (input_file_get, where, BUFFER_SIZE); 241 else 242 size = fread (where, sizeof (char), BUFFER_SIZE, f_in); 243 if (size < 0) 244 { 245 bfd_set_error (bfd_error_system_call); 246 as_perror (_("Can't read from %s"), file_name); 247 size = 0; 248 } 249 if (size) 250 return_value = where + size; 251 else 252 { 253 if (fclose (f_in)) 254 { 255 bfd_set_error (bfd_error_system_call); 256 as_perror (_("Can't close %s"), file_name); 257 } 258 f_in = (FILE *) 0; 259 return_value = 0; 260 } 261 262 return return_value; 263 } 264