1 /* input_scrub.c - Break up input buffers into whole numbers of lines.
2 Copyright (C) 1987-2016 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 3, 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 the Free
18 Software Foundation, 51 Franklin Street - Fifth Floor, Boston, MA
19 02110-1301, USA. */
20
21 #include "as.h"
22 #include "filenames.h"
23 #include "input-file.h"
24 #include "sb.h"
25 #include "listing.h"
26
27 /*
28 * O/S independent module to supply buffers of sanitised source code
29 * to rest of assembler. We get sanitised input data of arbitrary length.
30 * We break these buffers on line boundaries, recombine pieces that
31 * were broken across buffers, and return a buffer of full lines to
32 * the caller.
33 * The last partial line begins the next buffer we build and return to caller.
34 * The buffer returned to caller is preceded by BEFORE_STRING and followed
35 * by AFTER_STRING, as sentinels. The last character before AFTER_STRING
36 * is a newline.
37 * Also looks after line numbers, for e.g. error messages.
38 */
39
40 /*
41 * We don't care how filthy our buffers are, but our callers assume
42 * that the following sanitation has already been done.
43 *
44 * No comments, reduce a comment to a space.
45 * Reduce a tab to a space unless it is 1st char of line.
46 * All multiple tabs and spaces collapsed into 1 char. Tab only
47 * legal if 1st char of line.
48 * # line file statements converted to .line x;.file y; statements.
49 * Escaped newlines at end of line: remove them but add as many newlines
50 * to end of statement as you removed in the middle, to synch line numbers.
51 */
52
53 #define BEFORE_STRING ("\n")
54 #define AFTER_STRING ("\0") /* memcpy of 0 chars might choke. */
55 #define BEFORE_SIZE (1)
56 #define AFTER_SIZE (1)
57
58 #ifndef TC_EOL_IN_INSN
59 #define TC_EOL_IN_INSN(P) 0
60 #endif
61
62 static char *buffer_start; /*->1st char of full buffer area. */
63 static char *partial_where; /*->after last full line in buffer. */
64 static int partial_size; /* >=0. Number of chars in partial line in buffer. */
65
66 /* Because we need AFTER_STRING just after last full line, it clobbers
67 1st part of partial line. So we preserve 1st part of partial line
68 here. */
69 static char save_source[AFTER_SIZE];
70
71 /* What is the largest size buffer that input_file_give_next_buffer()
72 could return to us? */
73 static unsigned int buffer_length;
74
75 /* The index into an sb structure we are reading from. -1 if none. */
76 static size_t sb_index = -1;
77
78 /* If we are reading from an sb structure, this is it. */
79 static sb from_sb;
80
81 /* Should we do a conditional check on from_sb? */
82 static int from_sb_is_expansion = 1;
83
84 /* The number of nested sb structures we have included. */
85 int macro_nest;
86
87 /* We can have more than one source file open at once, though the info for all
88 but the latest one are saved off in a struct input_save. These files remain
89 open, so we are limited by the number of open files allowed by the
90 underlying OS. We may also sequentially read more than one source file in an
91 assembly. */
92
93 /* We must track the physical file and line number for error messages. We also
94 track a "logical" file and line number corresponding to (C?) compiler
95 source line numbers. Whenever we open a file we must fill in
96 physical_input_file. So if it is NULL we have not opened any files yet. */
97
98 static const char *physical_input_file;
99 static const char *logical_input_file;
100
101 /* 1-origin line number in a source file. */
102 /* A line ends in '\n' or eof. */
103 static unsigned int physical_input_line;
104 static int logical_input_line;
105
106 /* Struct used to save the state of the input handler during include files */
107 struct input_save {
108 char * buffer_start;
109 char * partial_where;
110 int partial_size;
111 char save_source[AFTER_SIZE];
112 size_t buffer_length;
113 const char * physical_input_file;
114 const char * logical_input_file;
115 unsigned int physical_input_line;
116 int logical_input_line;
117 size_t sb_index;
118 sb from_sb;
119 int from_sb_is_expansion; /* Should we do a conditional check? */
120 struct input_save * next_saved_file; /* Chain of input_saves. */
121 char * input_file_save; /* Saved state of input routines. */
122 char * saved_position; /* Caller's saved position in buf. */
123 };
124
125 static struct input_save *input_scrub_push (char *saved_position);
126 static char *input_scrub_pop (struct input_save *arg);
127
128 /* Saved information about the file that .include'd this one. When we hit EOF,
129 we automatically pop to that file. */
130
131 static struct input_save *next_saved_file;
132
133 /* Push the state of input reading and scrubbing so that we can #include.
134 The return value is a 'void *' (fudged for old compilers) to a save
135 area, which can be restored by passing it to input_scrub_pop(). */
136
137 static struct input_save *
input_scrub_push(char * saved_position)138 input_scrub_push (char *saved_position)
139 {
140 struct input_save *saved;
141
142 saved = XNEW (struct input_save);
143
144 saved->saved_position = saved_position;
145 saved->buffer_start = buffer_start;
146 saved->partial_where = partial_where;
147 saved->partial_size = partial_size;
148 saved->buffer_length = buffer_length;
149 saved->physical_input_file = physical_input_file;
150 saved->logical_input_file = logical_input_file;
151 saved->physical_input_line = physical_input_line;
152 saved->logical_input_line = logical_input_line;
153 saved->sb_index = sb_index;
154 saved->from_sb = from_sb;
155 saved->from_sb_is_expansion = from_sb_is_expansion;
156 memcpy (saved->save_source, save_source, sizeof (save_source));
157 saved->next_saved_file = next_saved_file;
158 saved->input_file_save = input_file_push ();
159
160 input_file_begin (); /* Reinitialize! */
161 logical_input_line = -1;
162 logical_input_file = NULL;
163 buffer_length = input_file_buffer_size ();
164 sb_index = -1;
165
166 buffer_start = XNEWVEC (char, (BEFORE_SIZE + buffer_length
167 + buffer_length + AFTER_SIZE + 1));
168 memcpy (buffer_start, BEFORE_STRING, (int) BEFORE_SIZE);
169
170 return saved;
171 }
172
173 static char *
input_scrub_pop(struct input_save * saved)174 input_scrub_pop (struct input_save *saved)
175 {
176 char *saved_position;
177
178 input_scrub_end (); /* Finish off old buffer */
179
180 input_file_pop (saved->input_file_save);
181 saved_position = saved->saved_position;
182 buffer_start = saved->buffer_start;
183 buffer_length = saved->buffer_length;
184 physical_input_file = saved->physical_input_file;
185 logical_input_file = saved->logical_input_file;
186 physical_input_line = saved->physical_input_line;
187 logical_input_line = saved->logical_input_line;
188 sb_index = saved->sb_index;
189 from_sb = saved->from_sb;
190 from_sb_is_expansion = saved->from_sb_is_expansion;
191 partial_where = saved->partial_where;
192 partial_size = saved->partial_size;
193 next_saved_file = saved->next_saved_file;
194 memcpy (save_source, saved->save_source, sizeof (save_source));
195
196 free (saved);
197 return saved_position;
198 }
199
200 void
input_scrub_begin(void)201 input_scrub_begin (void)
202 {
203 know (strlen (BEFORE_STRING) == BEFORE_SIZE);
204 know (strlen (AFTER_STRING) == AFTER_SIZE
205 || (AFTER_STRING[0] == '\0' && AFTER_SIZE == 1));
206
207 input_file_begin ();
208
209 buffer_length = input_file_buffer_size ();
210
211 buffer_start = XNEWVEC (char, (BEFORE_SIZE + buffer_length
212 + buffer_length + AFTER_SIZE + 1));
213 memcpy (buffer_start, BEFORE_STRING, (int) BEFORE_SIZE);
214
215 /* Line number things. */
216 logical_input_line = -1;
217 logical_input_file = NULL;
218 physical_input_file = NULL; /* No file read yet. */
219 next_saved_file = NULL; /* At EOF, don't pop to any other file */
220 do_scrub_begin (flag_m68k_mri);
221 }
222
223 void
input_scrub_end(void)224 input_scrub_end (void)
225 {
226 if (buffer_start)
227 {
228 free (buffer_start);
229 buffer_start = 0;
230 input_file_end ();
231 }
232 }
233
234 /* Start reading input from a new file.
235 Return start of caller's part of buffer. */
236
237 char *
input_scrub_new_file(const char * filename)238 input_scrub_new_file (const char *filename)
239 {
240 input_file_open (filename, !flag_no_comments);
241 physical_input_file = filename[0] ? filename : _("{standard input}");
242 physical_input_line = 0;
243
244 partial_size = 0;
245 return (buffer_start + BEFORE_SIZE);
246 }
247
248 /* Include a file from the current file. Save our state, cause it to
249 be restored on EOF, and begin handling a new file. Same result as
250 input_scrub_new_file. */
251
252 char *
input_scrub_include_file(const char * filename,char * position)253 input_scrub_include_file (const char *filename, char *position)
254 {
255 next_saved_file = input_scrub_push (position);
256 return input_scrub_new_file (filename);
257 }
258
259 /* Start getting input from an sb structure. This is used when
260 expanding a macro. */
261
262 void
input_scrub_include_sb(sb * from,char * position,int is_expansion)263 input_scrub_include_sb (sb *from, char *position, int is_expansion)
264 {
265 int newline;
266
267 if (macro_nest > max_macro_nest)
268 as_fatal (_("macros nested too deeply"));
269 ++macro_nest;
270
271 #ifdef md_macro_start
272 if (is_expansion)
273 {
274 md_macro_start ();
275 }
276 #endif
277
278 next_saved_file = input_scrub_push (position);
279
280 /* Allocate sufficient space: from->len + optional newline. */
281 newline = from->len >= 1 && from->ptr[0] != '\n';
282 sb_build (&from_sb, from->len + newline);
283 from_sb_is_expansion = is_expansion;
284 if (newline)
285 {
286 /* Add the sentinel required by read.c. */
287 sb_add_char (&from_sb, '\n');
288 }
289 sb_scrub_and_add_sb (&from_sb, from);
290
291 /* Make sure the parser looks at defined contents when it scans for
292 e.g. end-of-line at the end of a macro. */
293 sb_terminate (&from_sb);
294
295 sb_index = 1;
296
297 /* These variables are reset by input_scrub_push. Restore them
298 since we are, after all, still at the same point in the file. */
299 logical_input_line = next_saved_file->logical_input_line;
300 logical_input_file = next_saved_file->logical_input_file;
301 }
302
303 void
input_scrub_close(void)304 input_scrub_close (void)
305 {
306 input_file_close ();
307 physical_input_line = 0;
308 logical_input_line = -1;
309 }
310
311 char *
input_scrub_next_buffer(char ** bufp)312 input_scrub_next_buffer (char **bufp)
313 {
314 char *limit; /*->just after last char of buffer. */
315
316 if (sb_index != (size_t) -1)
317 {
318 if (sb_index >= from_sb.len)
319 {
320 sb_kill (&from_sb);
321 if (from_sb_is_expansion)
322 {
323 cond_finish_check (macro_nest);
324 #ifdef md_macro_end
325 /* Allow the target to clean up per-macro expansion
326 data. */
327 md_macro_end ();
328 #endif
329 }
330 --macro_nest;
331 partial_where = NULL;
332 partial_size = 0;
333 if (next_saved_file != NULL)
334 *bufp = input_scrub_pop (next_saved_file);
335 return partial_where;
336 }
337
338 partial_where = from_sb.ptr + from_sb.len;
339 partial_size = 0;
340 *bufp = from_sb.ptr + sb_index;
341 sb_index = from_sb.len;
342 return partial_where;
343 }
344
345 if (partial_size)
346 {
347 memmove (buffer_start + BEFORE_SIZE, partial_where,
348 (unsigned int) partial_size);
349 memcpy (buffer_start + BEFORE_SIZE, save_source, AFTER_SIZE);
350 }
351
352 while (1)
353 {
354 char *p;
355
356 *bufp = buffer_start + BEFORE_SIZE;
357 limit = input_file_give_next_buffer (buffer_start
358 + BEFORE_SIZE
359 + partial_size);
360 if (!limit)
361 {
362 if (partial_size == 0)
363 break;
364
365 as_warn (_("end of file not at end of a line; newline inserted"));
366 p = buffer_start + BEFORE_SIZE + partial_size;
367 *p++ = '\n';
368 limit = p;
369 }
370 else
371 {
372 /* Terminate the buffer to avoid confusing TC_EOL_IN_INSN. */
373 *limit = '\0';
374
375 /* Find last newline. */
376 for (p = limit - 1; *p != '\n' || TC_EOL_IN_INSN (p); --p)
377 ;
378 ++p;
379 }
380
381 if (p != buffer_start + BEFORE_SIZE)
382 {
383 partial_where = p;
384 partial_size = limit - p;
385 memcpy (save_source, partial_where, (int) AFTER_SIZE);
386 memcpy (partial_where, AFTER_STRING, (int) AFTER_SIZE);
387 return partial_where;
388 }
389
390 partial_size = limit - (buffer_start + BEFORE_SIZE);
391 buffer_length += input_file_buffer_size ();
392 buffer_start = XRESIZEVEC (char, buffer_start,
393 (BEFORE_SIZE
394 + 2 * buffer_length
395 + AFTER_SIZE + 1));
396 }
397
398 /* Tell the listing we've finished the file. */
399 LISTING_EOF ();
400
401 /* If we should pop to another file at EOF, do it. */
402 partial_where = NULL;
403 if (next_saved_file)
404 *bufp = input_scrub_pop (next_saved_file);
405
406 return partial_where;
407 }
408
409 /* The remaining part of this file deals with line numbers, error
410 messages and so on. Return TRUE if we opened any file. */
411
412 int
seen_at_least_1_file(void)413 seen_at_least_1_file (void)
414 {
415 return (physical_input_file != NULL);
416 }
417
418 void
bump_line_counters(void)419 bump_line_counters (void)
420 {
421 if (sb_index == (size_t) -1)
422 {
423 ++physical_input_line;
424 if (logical_input_line >= 0)
425 ++logical_input_line;
426 }
427 }
428
429 /* Tells us what the new logical line number and file are.
430 If the line_number is -1, we don't change the current logical line
431 number. If it is -2, we decrement the logical line number (this is
432 to support the .appfile pseudo-op inserted into the stream by
433 do_scrub_chars).
434 If the fname is NULL, we don't change the current logical file name.
435 Returns nonzero if the filename actually changes. */
436
437 int
new_logical_line_flags(const char * fname,int line_number,int flags)438 new_logical_line_flags (const char *fname, /* DON'T destroy it! We point to it! */
439 int line_number,
440 int flags)
441 {
442 switch (flags)
443 {
444 case 0:
445 break;
446 case 1:
447 if (line_number != -1)
448 abort ();
449 break;
450 case 1 << 1:
451 case 1 << 2:
452 /* FIXME: we could check that include nesting is correct. */
453 break;
454 default:
455 abort ();
456 }
457
458 if (line_number >= 0)
459 logical_input_line = line_number;
460 else if (line_number == -1 && fname && !*fname && (flags & (1 << 2)))
461 {
462 logical_input_file = physical_input_file;
463 logical_input_line = physical_input_line;
464 fname = NULL;
465 }
466
467 if (fname
468 && (logical_input_file == NULL
469 || filename_cmp (logical_input_file, fname)))
470 {
471 logical_input_file = fname;
472 return 1;
473 }
474 else
475 return 0;
476 }
477
478 int
new_logical_line(const char * fname,int line_number)479 new_logical_line (const char *fname, int line_number)
480 {
481 return new_logical_line_flags (fname, line_number, 0);
482 }
483
484
485 /* Return the current file name and line number. */
486
487 const char *
as_where(unsigned int * linep)488 as_where (unsigned int *linep)
489 {
490 if (logical_input_file != NULL
491 && (linep == NULL || logical_input_line >= 0))
492 {
493 if (linep != NULL)
494 *linep = logical_input_line;
495 return logical_input_file;
496 }
497 else if (physical_input_file != NULL)
498 {
499 if (linep != NULL)
500 *linep = physical_input_line;
501 return physical_input_file;
502 }
503 else
504 {
505 if (linep != NULL)
506 *linep = 0;
507 return NULL;
508 }
509 }
510