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.
6 This file is part of GAS, the GNU Assembler.
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)
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.
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
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! */
29 #include "input-file.h"
30 #include "safe-ctype.h"
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. */
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. */
42 #define BUFFER_SIZE (32 * 1024)
44 /* We use static data: the data area is not sharable. */
47 static char *file_name
;
49 /* Struct for saving the state of this module for file includes. */
58 /* These hooks accommodate most operating systems. */
61 input_file_begin (void)
71 /* Return BUFFER_SIZE. */
73 input_file_buffer_size (void)
78 /* Push the state of our input, returning a pointer to saved info that
79 can be restored with input_file_pop (). */
82 input_file_push (void)
84 register struct saved_file
*saved
;
86 saved
= (struct saved_file
*) xmalloc (sizeof *saved
);
89 saved
->file_name
= file_name
;
90 saved
->preprocess
= preprocess
;
92 saved
->app_save
= app_push ();
94 /* Initialize for new file. */
97 return (char *) saved
;
101 input_file_pop (char *arg
)
103 register struct saved_file
*saved
= (struct saved_file
*) arg
;
105 input_file_end (); /* Close out old file. */
108 file_name
= saved
->file_name
;
109 preprocess
= saved
->preprocess
;
111 app_pop (saved
->app_save
);
117 input_file_open (char *filename
, /* "" means use stdin. Must not be 0. */
125 gas_assert (filename
!= 0); /* Filename may not be NULL. */
128 f_in
= fopen (filename
, FOPEN_RT
);
129 file_name
= filename
;
133 /* Use stdin for the input file. */
135 /* For error messages. */
136 file_name
= _("{standard input}");
141 as_bad (_("can't open %s for reading: %s"),
142 file_name
, xstrerror (errno
));
150 as_bad (_("can't read from %s: %s"),
151 file_name
, xstrerror (errno
));
158 /* Check for an empty input file. */
165 gas_assert (c
!= EOF
);
169 /* Begins with comment, may not want to preprocess. */
173 if (fgets (buf
, sizeof (buf
), f_in
)
174 && !strncmp (buf
, "O_APP", 5) && ISSPACE (buf
[5]))
176 if (!strchr (buf
, '\n'))
177 ungetc ('#', f_in
); /* It was longer. */
183 if (fgets (buf
, sizeof (buf
), f_in
)
184 && !strncmp (buf
, "PP", 2) && ISSPACE (buf
[2]))
186 if (!strchr (buf
, '\n'))
200 /* Close input file. */
203 input_file_close (void)
205 /* Don't close a null file pointer. */
212 /* This function is passed to do_scrub_chars. */
215 input_file_get (char *buf
, size_t buflen
)
222 size
= fread (buf
, sizeof (char), buflen
, f_in
);
224 as_bad (_("can't read from %s: %s"), file_name
, xstrerror (errno
));
228 /* Read a buffer from the input file. */
231 input_file_give_next_buffer (char *where
/* Where to place 1st character of new buffer. */)
233 char *return_value
; /* -> Last char of what we read, + 1. */
236 if (f_in
== (FILE *) 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. */
243 size
= do_scrub_chars (input_file_get
, where
, BUFFER_SIZE
);
245 size
= input_file_get (where
, BUFFER_SIZE
);
248 return_value
= where
+ size
;
252 as_warn (_("can't close %s: %s"), file_name
, xstrerror (errno
));
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