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 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 static int input_file_get (char *, int); 33 34 /* This variable is non-zero if the file currently being read should be 35 preprocessed by app. It is zero if the file can be read straight in. */ 36 int preprocess = 0; 37 38 /* This code opens a file, then delivers BUFFER_SIZE character 39 chunks of the file on demand. 40 BUFFER_SIZE is supposed to be a number chosen for speed. 41 The caller only asks once what BUFFER_SIZE is, and asks before 42 the nature of the input files (if any) is known. */ 43 44 #define BUFFER_SIZE (32 * 1024) 45 46 /* We use static data: the data area is not sharable. */ 47 48 static FILE *f_in; 49 static char *file_name; 50 51 /* Struct for saving the state of this module for file includes. */ 52 struct saved_file 53 { 54 FILE * f_in; 55 char * file_name; 56 int preprocess; 57 char * app_save; 58 }; 59 60 /* These hooks accommodate most operating systems. */ 61 62 void 63 input_file_begin (void) 64 { 65 f_in = (FILE *) 0; 66 } 67 68 void 69 input_file_end (void) 70 { 71 } 72 73 /* Return BUFFER_SIZE. */ 74 unsigned int 75 input_file_buffer_size (void) 76 { 77 return (BUFFER_SIZE); 78 } 79 80 /* Push the state of our input, returning a pointer to saved info that 81 can be restored with input_file_pop (). */ 82 83 char * 84 input_file_push (void) 85 { 86 register struct saved_file *saved; 87 88 saved = (struct saved_file *) xmalloc (sizeof *saved); 89 90 saved->f_in = f_in; 91 saved->file_name = file_name; 92 saved->preprocess = preprocess; 93 if (preprocess) 94 saved->app_save = app_push (); 95 96 /* Initialize for new file. */ 97 input_file_begin (); 98 99 return (char *) saved; 100 } 101 102 void 103 input_file_pop (char *arg) 104 { 105 register struct saved_file *saved = (struct saved_file *) arg; 106 107 input_file_end (); /* Close out old file. */ 108 109 f_in = saved->f_in; 110 file_name = saved->file_name; 111 preprocess = saved->preprocess; 112 if (preprocess) 113 app_pop (saved->app_save); 114 115 free (arg); 116 } 117 118 void 119 input_file_open (char *filename, /* "" means use stdin. Must not be 0. */ 120 int pre) 121 { 122 int c; 123 char buf[80]; 124 125 preprocess = pre; 126 127 assert (filename != 0); /* Filename may not be NULL. */ 128 if (filename[0]) 129 { 130 f_in = fopen (filename, FOPEN_RT); 131 file_name = filename; 132 } 133 else 134 { 135 /* Use stdin for the input file. */ 136 f_in = stdin; 137 /* For error messages. */ 138 file_name = _("{standard input}"); 139 } 140 141 if (f_in == NULL) 142 { 143 as_bad (_("can't open %s for reading: %s"), 144 file_name, xstrerror (errno)); 145 return; 146 } 147 148 c = getc (f_in); 149 150 if (ferror (f_in)) 151 { 152 as_bad (_("can't read from %s: %s"), 153 file_name, xstrerror (errno)); 154 155 fclose (f_in); 156 f_in = NULL; 157 return; 158 } 159 160 if (c == '#') 161 { 162 /* Begins with comment, may not want to preprocess. */ 163 c = getc (f_in); 164 if (c == 'N') 165 { 166 if (fgets (buf, sizeof (buf), f_in) 167 && !strncmp (buf, "O_APP", 5) && ISSPACE (buf[5])) 168 preprocess = 0; 169 if (!strchr (buf, '\n')) 170 ungetc ('#', f_in); /* It was longer. */ 171 else 172 ungetc ('\n', f_in); 173 } 174 else if (c == 'A') 175 { 176 if (fgets (buf, sizeof (buf), f_in) 177 && !strncmp (buf, "PP", 2) && ISSPACE (buf[2])) 178 preprocess = 1; 179 if (!strchr (buf, '\n')) 180 ungetc ('#', f_in); 181 else 182 ungetc ('\n', f_in); 183 } 184 else if (c == '\n') 185 ungetc ('\n', f_in); 186 else 187 ungetc ('#', f_in); 188 } 189 else 190 ungetc (c, f_in); 191 } 192 193 /* Close input file. */ 194 195 void 196 input_file_close (void) 197 { 198 /* Don't close a null file pointer. */ 199 if (f_in != NULL) 200 fclose (f_in); 201 202 f_in = 0; 203 } 204 205 /* This function is passed to do_scrub_chars. */ 206 207 static int 208 input_file_get (char *buf, int buflen) 209 { 210 int size; 211 212 size = fread (buf, sizeof (char), buflen, f_in); 213 if (size < 0) 214 { 215 as_bad (_("can't read from %s: %s"), file_name, xstrerror (errno)); 216 size = 0; 217 } 218 return size; 219 } 220 221 /* Read a buffer from the input file. */ 222 223 char * 224 input_file_give_next_buffer (char *where /* Where to place 1st character of new buffer. */) 225 { 226 char *return_value; /* -> Last char of what we read, + 1. */ 227 register int size; 228 229 if (f_in == (FILE *) 0) 230 return 0; 231 /* fflush (stdin); could be done here if you want to synchronise 232 stdin and stdout, for the case where our input file is stdin. 233 Since the assembler shouldn't do any output to stdout, we 234 don't bother to synch output and input. */ 235 if (preprocess) 236 size = do_scrub_chars (input_file_get, where, BUFFER_SIZE); 237 else 238 size = fread (where, sizeof (char), BUFFER_SIZE, f_in); 239 if (size < 0) 240 { 241 as_bad (_("can't read from %s: %s"), file_name, xstrerror (errno)); 242 size = 0; 243 } 244 if (size) 245 return_value = where + size; 246 else 247 { 248 if (fclose (f_in)) 249 as_warn (_("can't close %s: %s"), file_name, xstrerror (errno)); 250 251 f_in = (FILE *) 0; 252 return_value = 0; 253 } 254 255 return return_value; 256 } 257