1 /* input_file.c - Deal with Input Files -
2 Copyright (C) 1987-2014 Free Software Foundation, Inc.
4 This file is part of GAS, the GNU Assembler.
6 GAS is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 3, or (at your option)
11 GAS is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with GAS; see the file COPYING. If not, write to the Free
18 Software Foundation, 51 Franklin Street - Fifth Floor, Boston, MA
21 /* Confines all details of reading source bytes to this module.
22 All O/S specific crocks should live here.
23 What we lose in "efficiency" we gain in modularity.
24 Note we don't need to #include the "as.h" file. No common coupling! */
27 #include "input-file.h"
28 #include "safe-ctype.h"
30 /* This variable is non-zero if the file currently being read should be
31 preprocessed by app. It is zero if the file can be read straight in. */
34 /* This code opens a file, then delivers BUFFER_SIZE character
35 chunks of the file on demand.
36 BUFFER_SIZE is supposed to be a number chosen for speed.
37 The caller only asks once what BUFFER_SIZE is, and asks before
38 the nature of the input files (if any) is known. */
40 #define BUFFER_SIZE (32 * 1024)
42 /* We use static data: the data area is not sharable. */
45 static char *file_name
;
47 /* Struct for saving the state of this module for file includes. */
56 /* These hooks accommodate most operating systems. */
59 input_file_begin (void)
69 /* Return BUFFER_SIZE. */
71 input_file_buffer_size (void)
76 /* Push the state of our input, returning a pointer to saved info that
77 can be restored with input_file_pop (). */
80 input_file_push (void)
82 register struct saved_file
*saved
;
84 saved
= (struct saved_file
*) xmalloc (sizeof *saved
);
87 saved
->file_name
= file_name
;
88 saved
->preprocess
= preprocess
;
90 saved
->app_save
= app_push ();
92 /* Initialize for new file. */
95 return (char *) saved
;
99 input_file_pop (char *arg
)
101 register struct saved_file
*saved
= (struct saved_file
*) arg
;
103 input_file_end (); /* Close out old file. */
106 file_name
= saved
->file_name
;
107 preprocess
= saved
->preprocess
;
109 app_pop (saved
->app_save
);
115 input_file_open (char *filename
, /* "" means use stdin. Must not be 0. */
123 gas_assert (filename
!= 0); /* Filename may not be NULL. */
126 f_in
= fopen (filename
, FOPEN_RT
);
127 file_name
= filename
;
131 /* Use stdin for the input file. */
133 /* For error messages. */
134 file_name
= _("{standard input}");
139 as_bad (_("can't open %s for reading: %s"),
140 file_name
, xstrerror (errno
));
148 as_bad (_("can't read from %s: %s"),
149 file_name
, xstrerror (errno
));
156 /* Check for an empty input file. */
163 gas_assert (c
!= EOF
);
167 /* Begins with comment, may not want to preprocess. */
171 if (fgets (buf
, sizeof (buf
), f_in
)
172 && !strncmp (buf
, "O_APP", 5) && ISSPACE (buf
[5]))
174 if (!strchr (buf
, '\n'))
175 ungetc ('#', f_in
); /* It was longer. */
181 if (fgets (buf
, sizeof (buf
), f_in
)
182 && !strncmp (buf
, "PP", 2) && ISSPACE (buf
[2]))
184 if (!strchr (buf
, '\n'))
198 /* Close input file. */
201 input_file_close (void)
203 /* Don't close a null file pointer. */
210 /* This function is passed to do_scrub_chars. */
213 input_file_get (char *buf
, size_t buflen
)
220 size
= fread (buf
, sizeof (char), buflen
, f_in
);
222 as_bad (_("can't read from %s: %s"), file_name
, xstrerror (errno
));
226 /* Read a buffer from the input file. */
229 input_file_give_next_buffer (char *where
/* Where to place 1st character of new buffer. */)
231 char *return_value
; /* -> Last char of what we read, + 1. */
234 if (f_in
== (FILE *) 0)
236 /* fflush (stdin); could be done here if you want to synchronise
237 stdin and stdout, for the case where our input file is stdin.
238 Since the assembler shouldn't do any output to stdout, we
239 don't bother to synch output and input. */
241 size
= do_scrub_chars (input_file_get
, where
, BUFFER_SIZE
);
243 size
= input_file_get (where
, BUFFER_SIZE
);
246 return_value
= where
+ size
;
250 as_warn (_("can't close %s: %s"), file_name
, xstrerror (errno
));
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