input-file.c revision 89857
1/* input_file.c - Deal with Input Files - 2 Copyright 1987, 1990, 1991, 1992, 1993, 1994, 1995, 1999, 2000, 2001 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/* Confines all details of reading source bytes to this module. 23 All O/S specific crocks should live here. 24 What we lose in "efficiency" we gain in modularity. 25 Note we don't need to #include the "as.h" file. No common coupling! */ 26 27#include <stdio.h> 28#include <string.h> 29#include "as.h" 30#include "input-file.h" 31#include "safe-ctype.h" 32 33static int input_file_get PARAMS ((char *, int)); 34 35/* This variable is non-zero if the file currently being read should be 36 preprocessed by app. It is zero if the file can be read straight in. */ 37int preprocess = 0; 38 39/* This code opens a file, then delivers BUFFER_SIZE character 40 chunks of the file on demand. 41 BUFFER_SIZE is supposed to be a number chosen for speed. 42 The caller only asks once what BUFFER_SIZE is, and asks before 43 the nature of the input files (if any) is known. */ 44 45#define BUFFER_SIZE (32 * 1024) 46 47/* We use static data: the data area is not sharable. */ 48 49static FILE *f_in; 50static char *file_name; 51 52/* Struct for saving the state of this module for file includes. */ 53struct saved_file 54 { 55 FILE * f_in; 56 char * file_name; 57 int preprocess; 58 char * app_save; 59 }; 60 61/* These hooks accomodate most operating systems. */ 62 63void 64input_file_begin () 65{ 66 f_in = (FILE *) 0; 67} 68 69void 70input_file_end () 71{ 72} 73 74/* Return BUFFER_SIZE. */ 75unsigned int 76input_file_buffer_size () 77{ 78 return (BUFFER_SIZE); 79} 80 81int 82input_file_is_open () 83{ 84 return f_in != (FILE *) 0; 85} 86 87/* Push the state of our input, returning a pointer to saved info that 88 can be restored with input_file_pop (). */ 89 90char * 91input_file_push () 92{ 93 register struct saved_file *saved; 94 95 saved = (struct saved_file *) xmalloc (sizeof *saved); 96 97 saved->f_in = f_in; 98 saved->file_name = file_name; 99 saved->preprocess = preprocess; 100 if (preprocess) 101 saved->app_save = app_push (); 102 103 /* Initialize for new file. */ 104 input_file_begin (); 105 106 return (char *) saved; 107} 108 109void 110input_file_pop (arg) 111 char *arg; 112{ 113 register struct saved_file *saved = (struct saved_file *) arg; 114 115 input_file_end (); /* Close out old file. */ 116 117 f_in = saved->f_in; 118 file_name = saved->file_name; 119 preprocess = saved->preprocess; 120 if (preprocess) 121 app_pop (saved->app_save); 122 123 free (arg); 124} 125 126void 127input_file_open (filename, pre) 128 char *filename; /* "" means use stdin. Must not be 0. */ 129 int pre; 130{ 131 int c; 132 char buf[80]; 133 134 preprocess = pre; 135 136 assert (filename != 0); /* Filename may not be NULL. */ 137 if (filename[0]) 138 { /* We have a file name. Suck it and see. */ 139 f_in = fopen (filename, FOPEN_RT); 140 file_name = filename; 141 } 142 else 143 { /* use stdin for the input file. */ 144 f_in = stdin; 145 file_name = _("{standard input}"); /* For error messages. */ 146 } 147 if (f_in == (FILE *) 0) 148 { 149 as_bad (_("can't open %s for reading"), file_name); 150 as_perror ("%s", file_name); 151 return; 152 } 153 154 c = getc (f_in); 155 if (c == '#') 156 { 157 /* Begins with comment, may not want to preprocess. */ 158 c = getc (f_in); 159 if (c == 'N') 160 { 161 fgets (buf, 80, f_in); 162 if (!strncmp (buf, "O_APP", 5) && ISSPACE (buf[5])) 163 preprocess = 0; 164 if (!strchr (buf, '\n')) 165 ungetc ('#', f_in); /* It was longer. */ 166 else 167 ungetc ('\n', f_in); 168 } 169 else if (c == 'A') 170 { 171 fgets (buf, 80, f_in); 172 if (!strncmp (buf, "PP", 2) && ISSPACE (buf[2])) 173 preprocess = 1; 174 if (!strchr (buf, '\n')) 175 ungetc ('#', f_in); 176 else 177 ungetc ('\n', f_in); 178 } 179 else if (c == '\n') 180 ungetc ('\n', f_in); 181 else 182 ungetc ('#', f_in); 183 } 184 else 185 ungetc (c, f_in); 186} 187 188/* Close input file. */ 189 190void 191input_file_close () 192{ 193 /* Don't close a null file pointer. */ 194 if (f_in != NULL) 195 fclose (f_in); 196 197 f_in = 0; 198} 199 200/* This function is passed to do_scrub_chars. */ 201 202static int 203input_file_get (buf, buflen) 204 char *buf; 205 int buflen; 206{ 207 int size; 208 209 size = fread (buf, sizeof (char), buflen, f_in); 210 if (size < 0) 211 { 212 as_perror (_("Can't read from %s"), file_name); 213 size = 0; 214 } 215 return size; 216} 217 218/* Read a buffer from the input file. */ 219 220char * 221input_file_give_next_buffer (where) 222 char *where; /* Where to place 1st character of new buffer. */ 223{ 224 char *return_value; /* -> Last char of what we read, + 1. */ 225 register int size; 226 227 if (f_in == (FILE *) 0) 228 return 0; 229 /* fflush (stdin); could be done here if you want to synchronise 230 stdin and stdout, for the case where our input file is stdin. 231 Since the assembler shouldn't do any output to stdout, we 232 don't bother to synch output and input. */ 233 if (preprocess) 234 size = do_scrub_chars (input_file_get, where, BUFFER_SIZE); 235 else 236 size = fread (where, sizeof (char), BUFFER_SIZE, f_in); 237 if (size < 0) 238 { 239 as_perror (_("Can't read from %s"), file_name); 240 size = 0; 241 } 242 if (size) 243 return_value = where + size; 244 else 245 { 246 if (fclose (f_in)) 247 as_perror (_("Can't close %s"), file_name); 248 f_in = (FILE *) 0; 249 return_value = 0; 250 } 251 252 return return_value; 253} 254