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252b5132 RH |
1 | /* input_file.c - Deal with Input Files - |
2 | Copyright (C) 1987, 1990, 1991, 1992, 1998 Free Software Foundation, Inc. | |
3 | ||
4 | This file is part of GAS, the GNU Assembler. | |
5 | ||
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 2, or (at your option) | |
9 | any later version. | |
10 | ||
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. | |
15 | ||
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 | |
18 | the Free Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ | |
19 | ||
20 | /* | |
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! | |
25 | */ | |
26 | ||
27 | #include <stdio.h> | |
28 | #include <string.h> | |
29 | ||
30 | #include "as.h" | |
31 | #include "input-file.h" | |
32 | ||
33 | static int input_file_get PARAMS ((char **)); | |
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. | |
37 | */ | |
38 | int preprocess = 0; | |
39 | ||
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 | ||
48 | #define BUFFER_SIZE (32 * 1024) | |
49 | ||
50 | /* | |
51 | * We use static data: the data area is not sharable. | |
52 | */ | |
53 | ||
54 | static FILE *f_in; | |
55 | static char *file_name; | |
56 | ||
57 | /* Struct for saving the state of this module for file includes. */ | |
58 | struct saved_file | |
59 | { | |
60 | FILE *f_in; | |
61 | char *file_name; | |
62 | int preprocess; | |
63 | char *app_save; | |
64 | }; | |
65 | \f | |
66 | /* These hooks accomodate most operating systems. */ | |
67 | ||
68 | void | |
69 | input_file_begin () | |
70 | { | |
71 | f_in = (FILE *) 0; | |
72 | } | |
73 | ||
74 | void | |
75 | input_file_end () | |
76 | { | |
77 | } | |
78 | ||
79 | /* Return BUFFER_SIZE. */ | |
80 | unsigned int | |
81 | input_file_buffer_size () | |
82 | { | |
83 | return (BUFFER_SIZE); | |
84 | } | |
85 | ||
86 | int | |
87 | input_file_is_open () | |
88 | { | |
89 | return f_in != (FILE *) 0; | |
90 | } | |
91 | ||
92 | /* Push the state of our input, returning a pointer to saved info that | |
93 | can be restored with input_file_pop (). */ | |
94 | char * | |
95 | input_file_push () | |
96 | { | |
97 | register struct saved_file *saved; | |
98 | ||
99 | saved = (struct saved_file *) xmalloc (sizeof *saved); | |
100 | ||
101 | saved->f_in = f_in; | |
102 | saved->file_name = file_name; | |
103 | saved->preprocess = preprocess; | |
104 | if (preprocess) | |
105 | saved->app_save = app_push (); | |
106 | ||
107 | input_file_begin (); /* Initialize for new file */ | |
108 | ||
109 | return (char *) saved; | |
110 | } | |
111 | ||
112 | void | |
113 | input_file_pop (arg) | |
114 | char *arg; | |
115 | { | |
116 | register struct saved_file *saved = (struct saved_file *) arg; | |
117 | ||
118 | input_file_end (); /* Close out old file */ | |
119 | ||
120 | f_in = saved->f_in; | |
121 | file_name = saved->file_name; | |
122 | preprocess = saved->preprocess; | |
123 | if (preprocess) | |
124 | app_pop (saved->app_save); | |
125 | ||
126 | free (arg); | |
127 | } | |
128 | \f | |
129 | void | |
130 | input_file_open (filename, pre) | |
131 | char *filename; /* "" means use stdin. Must not be 0. */ | |
132 | int pre; | |
133 | { | |
134 | int c; | |
135 | char buf[80]; | |
136 | ||
137 | preprocess = pre; | |
138 | ||
139 | assert (filename != 0); /* Filename may not be NULL. */ | |
140 | if (filename[0]) | |
141 | { /* We have a file name. Suck it and see. */ | |
142 | f_in = fopen (filename, "r"); | |
143 | file_name = filename; | |
144 | } | |
145 | else | |
146 | { /* use stdin for the input file. */ | |
147 | f_in = stdin; | |
148 | file_name = _("{standard input}"); /* For error messages. */ | |
149 | } | |
150 | if (f_in == (FILE *) 0) | |
151 | { | |
152 | as_bad (_("Can't open %s for reading."), file_name); | |
153 | as_perror ("%s", file_name); | |
154 | return; | |
155 | } | |
156 | ||
157 | c = getc (f_in); | |
158 | if (c == '#') | |
159 | { /* Begins with comment, may not want to preprocess */ | |
160 | c = getc (f_in); | |
161 | if (c == 'N') | |
162 | { | |
163 | fgets (buf, 80, f_in); | |
164 | if (!strcmp (buf, "O_APP\n")) | |
165 | preprocess = 0; | |
166 | if (!strchr (buf, '\n')) | |
167 | ungetc ('#', f_in); /* It was longer */ | |
168 | else | |
169 | ungetc ('\n', f_in); | |
170 | } | |
171 | else if (c == '\n') | |
172 | ungetc ('\n', f_in); | |
173 | else | |
174 | ungetc ('#', f_in); | |
175 | } | |
176 | else | |
177 | ungetc (c, f_in); | |
178 | } | |
179 | ||
180 | /* Close input file. */ | |
181 | void | |
182 | input_file_close () | |
183 | { | |
184 | if (f_in != NULL) | |
185 | { | |
186 | fclose (f_in); | |
187 | } /* don't close a null file pointer */ | |
188 | f_in = 0; | |
189 | } /* input_file_close() */ | |
190 | ||
191 | /* This function is passed to do_scrub_chars. */ | |
192 | ||
193 | static int | |
194 | input_file_get (from) | |
195 | char **from; | |
196 | { | |
197 | static char buf[BUFFER_SIZE]; | |
198 | int size; | |
199 | ||
200 | size = fread (buf, sizeof (char), sizeof buf, f_in); | |
201 | if (size < 0) | |
202 | { | |
203 | as_perror (_("Can't read from %s"), file_name); | |
204 | size = 0; | |
205 | } | |
206 | *from = buf; | |
207 | return size; | |
208 | } | |
209 | ||
210 | /* Read a buffer from the input file. */ | |
211 | ||
212 | char * | |
213 | input_file_give_next_buffer (where) | |
214 | char *where; /* Where to place 1st character of new buffer. */ | |
215 | { | |
216 | char *return_value; /* -> Last char of what we read, + 1. */ | |
217 | register int size; | |
218 | ||
219 | if (f_in == (FILE *) 0) | |
220 | return 0; | |
221 | /* | |
222 | * fflush (stdin); could be done here if you want to synchronise | |
223 | * stdin and stdout, for the case where our input file is stdin. | |
224 | * Since the assembler shouldn't do any output to stdout, we | |
225 | * don't bother to synch output and input. | |
226 | */ | |
227 | if (preprocess) | |
228 | size = do_scrub_chars (input_file_get, where, BUFFER_SIZE); | |
229 | else | |
230 | size = fread (where, sizeof (char), BUFFER_SIZE, f_in); | |
231 | if (size < 0) | |
232 | { | |
233 | as_perror (_("Can't read from %s"), file_name); | |
234 | size = 0; | |
235 | } | |
236 | if (size) | |
237 | return_value = where + size; | |
238 | else | |
239 | { | |
240 | if (fclose (f_in)) | |
241 | as_perror (_("Can't close %s"), file_name); | |
242 | f_in = (FILE *) 0; | |
243 | return_value = 0; | |
244 | } | |
245 | return (return_value); | |
246 | } | |
247 | ||
248 | /* end of input-file.c */ |