1 /* input_scrub.c - Break up input buffers into whole numbers of lines.
2 Copyright (C) 1987-2022 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 size_t 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 /* The size of the input buffer we concatenate
72 input_file_give_next_buffer chunks into. Excludes the BEFORE and
73 AFTER counts. */
74 static size_t buffer_length;
75
76 /* The index into an sb structure we are reading from. -1 if none. */
77 static size_t sb_index = -1;
78
79 /* If we are reading from an sb structure, this is it. */
80 static sb from_sb;
81
82 /* Should we do a conditional check on from_sb? */
83 static enum expansion from_sb_expansion = expanding_none;
84
85 /* The number of nested sb structures we have included. */
86 int macro_nest;
87
88 /* We can have more than one source file open at once, though the info for all
89 but the latest one are saved off in a struct input_save. These files remain
90 open, so we are limited by the number of open files allowed by the
91 underlying OS. We may also sequentially read more than one source file in an
92 assembly. */
93
94 /* We must track the physical file and line number for error messages. We also
95 track a "logical" file and line number corresponding to (C?) compiler
96 source line numbers. Whenever we open a file we must fill in
97 physical_input_file. So if it is NULL we have not opened any files yet. */
98
99 static const char *physical_input_file;
100 static const char *logical_input_file;
101
102 /* 1-origin line number in a source file. */
103 /* A line ends in '\n' or eof. */
104 static unsigned int physical_input_line;
105 static unsigned int logical_input_line;
106
107 /* Struct used to save the state of the input handler during include files */
108 struct input_save {
109 char * buffer_start;
110 char * partial_where;
111 size_t partial_size;
112 char save_source[AFTER_SIZE];
113 size_t buffer_length;
114 const char * physical_input_file;
115 const char * logical_input_file;
116 unsigned int physical_input_line;
117 unsigned int logical_input_line;
118 size_t sb_index;
119 sb from_sb;
120 enum expansion from_sb_expansion; /* Should we do a conditional check? */
121 struct input_save * next_saved_file; /* Chain of input_saves. */
122 char * input_file_save; /* Saved state of input routines. */
123 char * saved_position; /* Caller's saved position in buf. */
124 };
125
126 static struct input_save *input_scrub_push (char *saved_position);
127 static char *input_scrub_pop (struct input_save *arg);
128
129 /* Saved information about the file that .include'd this one. When we hit EOF,
130 we automatically pop to that file. */
131
132 static struct input_save *next_saved_file;
133
134 /* Initialize input buffering. */
135
136 static void
input_scrub_reinit(void)137 input_scrub_reinit (void)
138 {
139 input_file_begin (); /* Reinitialize! */
140 logical_input_line = -1u;
141 logical_input_file = NULL;
142 sb_index = -1;
143
144 buffer_length = input_file_buffer_size () * 2;
145 buffer_start = XNEWVEC (char, BEFORE_SIZE + AFTER_SIZE + 1 + buffer_length);
146 memcpy (buffer_start, BEFORE_STRING, (int) BEFORE_SIZE);
147 }
148
149 /* Push the state of input reading and scrubbing so that we can #include.
150 The return value is a 'void *' (fudged for old compilers) to a save
151 area, which can be restored by passing it to input_scrub_pop(). */
152
153 static struct input_save *
input_scrub_push(char * saved_position)154 input_scrub_push (char *saved_position)
155 {
156 struct input_save *saved;
157
158 saved = XNEW (struct input_save);
159
160 saved->saved_position = saved_position;
161 saved->buffer_start = buffer_start;
162 saved->partial_where = partial_where;
163 saved->partial_size = partial_size;
164 saved->buffer_length = buffer_length;
165 saved->physical_input_file = physical_input_file;
166 saved->logical_input_file = logical_input_file;
167 saved->physical_input_line = physical_input_line;
168 saved->logical_input_line = logical_input_line;
169 saved->sb_index = sb_index;
170 saved->from_sb = from_sb;
171 saved->from_sb_expansion = from_sb_expansion;
172 memcpy (saved->save_source, save_source, sizeof (save_source));
173 saved->next_saved_file = next_saved_file;
174 saved->input_file_save = input_file_push ();
175
176 input_scrub_reinit ();
177
178 return saved;
179 }
180
181 static char *
input_scrub_pop(struct input_save * saved)182 input_scrub_pop (struct input_save *saved)
183 {
184 char *saved_position;
185
186 input_scrub_end (); /* Finish off old buffer */
187
188 input_file_pop (saved->input_file_save);
189 saved_position = saved->saved_position;
190 buffer_start = saved->buffer_start;
191 buffer_length = saved->buffer_length;
192 physical_input_file = saved->physical_input_file;
193 logical_input_file = saved->logical_input_file;
194 physical_input_line = saved->physical_input_line;
195 logical_input_line = saved->logical_input_line;
196 sb_index = saved->sb_index;
197 from_sb = saved->from_sb;
198 from_sb_expansion = saved->from_sb_expansion;
199 partial_where = saved->partial_where;
200 partial_size = saved->partial_size;
201 next_saved_file = saved->next_saved_file;
202 memcpy (save_source, saved->save_source, sizeof (save_source));
203
204 free (saved);
205 return saved_position;
206 }
207
208 void
input_scrub_begin(void)209 input_scrub_begin (void)
210 {
211 know (strlen (BEFORE_STRING) == BEFORE_SIZE);
212 know (strlen (AFTER_STRING) == AFTER_SIZE
213 || (AFTER_STRING[0] == '\0' && AFTER_SIZE == 1));
214
215 physical_input_file = NULL; /* No file read yet. */
216 next_saved_file = NULL; /* At EOF, don't pop to any other file */
217 input_scrub_reinit ();
218 do_scrub_begin (flag_m68k_mri);
219 }
220
221 void
input_scrub_end(void)222 input_scrub_end (void)
223 {
224 if (buffer_start)
225 {
226 free (buffer_start);
227 buffer_start = 0;
228 input_file_end ();
229 }
230 }
231
232 /* Start reading input from a new file.
233 Return start of caller's part of buffer. */
234
235 char *
input_scrub_new_file(const char * filename)236 input_scrub_new_file (const char *filename)
237 {
238 input_file_open (filename, !flag_no_comments);
239 physical_input_file = filename[0] ? filename : _("{standard input}");
240 physical_input_line = 0;
241
242 partial_size = 0;
243 return (buffer_start + BEFORE_SIZE);
244 }
245
246 /* Include a file from the current file. Save our state, cause it to
247 be restored on EOF, and begin handling a new file. Same result as
248 input_scrub_new_file. */
249
250 char *
input_scrub_include_file(const char * filename,char * position)251 input_scrub_include_file (const char *filename, char *position)
252 {
253 next_saved_file = input_scrub_push (position);
254 from_sb_expansion = expanding_none;
255 return input_scrub_new_file (filename);
256 }
257
258 /* Start getting input from an sb structure. This is used when
259 expanding a macro. */
260
261 void
input_scrub_include_sb(sb * from,char * position,enum expansion expansion)262 input_scrub_include_sb (sb *from, char *position, enum expansion expansion)
263 {
264 int newline;
265
266 if (macro_nest > max_macro_nest)
267 as_fatal (_("macros nested too deeply"));
268 ++macro_nest;
269
270 gas_assert (expansion < expanding_nested);
271
272 #ifdef md_macro_start
273 if (expansion == expanding_macro)
274 {
275 md_macro_start ();
276 }
277 #endif
278
279 next_saved_file = input_scrub_push (position);
280
281 /* Allocate sufficient space: from->len plus optional newline
282 plus two ".linefile " directives, plus a little more for other
283 expansion. */
284 newline = from->len >= 1 && from->ptr[0] != '\n';
285 sb_build (&from_sb, from->len + newline + 2 * sizeof (".linefile") + 30);
286 if (expansion == expanding_repeat && from_sb_expansion >= expanding_macro)
287 expansion = expanding_nested;
288 from_sb_expansion = expansion;
289 if (newline)
290 {
291 /* Add the sentinel required by read.c. */
292 sb_add_char (&from_sb, '\n');
293 }
294 sb_scrub_and_add_sb (&from_sb, from);
295
296 /* Make sure the parser looks at defined contents when it scans for
297 e.g. end-of-line at the end of a macro. */
298 sb_terminate (&from_sb);
299
300 sb_index = 1;
301
302 /* These variables are reset by input_scrub_push. Restore them
303 since we are, after all, still at the same point in the file. */
304 logical_input_line = next_saved_file->logical_input_line;
305 logical_input_file = next_saved_file->logical_input_file;
306 }
307
308 void
input_scrub_close(void)309 input_scrub_close (void)
310 {
311 input_file_close ();
312 physical_input_line = 0;
313 logical_input_line = -1u;
314 }
315
316 char *
input_scrub_next_buffer(char ** bufp)317 input_scrub_next_buffer (char **bufp)
318 {
319 char *limit; /*->just after last char of buffer. */
320
321 if (sb_index != (size_t) -1)
322 {
323 if (sb_index >= from_sb.len)
324 {
325 sb_kill (&from_sb);
326 if (from_sb_expansion == expanding_macro)
327 {
328 cond_finish_check (macro_nest);
329 #ifdef md_macro_end
330 /* Allow the target to clean up per-macro expansion
331 data. */
332 md_macro_end ();
333 #endif
334 }
335 --macro_nest;
336 partial_where = NULL;
337 partial_size = 0;
338 if (next_saved_file != NULL)
339 *bufp = input_scrub_pop (next_saved_file);
340 return partial_where;
341 }
342
343 partial_where = from_sb.ptr + from_sb.len;
344 partial_size = 0;
345 *bufp = from_sb.ptr + sb_index;
346 sb_index = from_sb.len;
347 return partial_where;
348 }
349
350 if (partial_size)
351 {
352 memmove (buffer_start + BEFORE_SIZE, partial_where, partial_size);
353 memcpy (buffer_start + BEFORE_SIZE, save_source, AFTER_SIZE);
354 }
355
356 while (1)
357 {
358 char *p;
359 char *start = buffer_start + BEFORE_SIZE + partial_size;
360
361 *bufp = buffer_start + BEFORE_SIZE;
362 limit = input_file_give_next_buffer (start);
363 if (!limit)
364 {
365 if (!partial_size)
366 /* End of this file. */
367 break;
368
369 as_warn (_("end of file not at end of a line; newline inserted"));
370 p = buffer_start + BEFORE_SIZE + partial_size;
371 *p++ = '\n';
372 limit = p;
373 }
374 else
375 {
376 /* Terminate the buffer to avoid confusing TC_EOL_IN_INSN. */
377 *limit = '\0';
378
379 /* Find last newline. */
380 for (p = limit - 1; *p != '\n' || TC_EOL_IN_INSN (p); --p)
381 if (p < start)
382 goto read_more;
383 ++p;
384 }
385
386 if (multibyte_handling == multibyte_warn)
387 (void) scan_for_multibyte_characters ((const unsigned char *) p,
388 (const unsigned char *) limit,
389 true /* Generate warnings */);
390
391 /* We found a newline in the newly read chars. */
392 partial_where = p;
393 partial_size = limit - p;
394
395 /* Save the fragment after that last newline. */
396 memcpy (save_source, partial_where, (int) AFTER_SIZE);
397 memcpy (partial_where, AFTER_STRING, (int) AFTER_SIZE);
398 return partial_where;
399
400 read_more:
401 /* Didn't find a newline. Read more text. */
402 partial_size = limit - (buffer_start + BEFORE_SIZE);
403 if (buffer_length - input_file_buffer_size () < partial_size)
404 {
405 /* Increase the buffer when it doesn't have room for the
406 next block of input. */
407 buffer_length *= 2;
408 buffer_start = XRESIZEVEC (char, buffer_start,
409 (buffer_length
410 + BEFORE_SIZE + AFTER_SIZE + 1));
411 }
412 }
413
414 /* Tell the listing we've finished the file. */
415 LISTING_EOF ();
416
417 /* If we should pop to another file at EOF, do it. */
418 partial_where = NULL;
419 if (next_saved_file)
420 *bufp = input_scrub_pop (next_saved_file);
421
422 return partial_where;
423 }
424
425 /* The remaining part of this file deals with line numbers, error
426 messages and so on. Return TRUE if we opened any file. */
427
428 int
seen_at_least_1_file(void)429 seen_at_least_1_file (void)
430 {
431 return (physical_input_file != NULL);
432 }
433
434 void
bump_line_counters(void)435 bump_line_counters (void)
436 {
437 if (sb_index == (size_t) -1)
438 ++physical_input_line;
439
440 /* PR gas/16908 workaround: Don't bump logical line numbers while
441 expanding macros, unless file (and maybe line; see as_where()) are
442 used inside the macro. */
443 if (logical_input_line != -1u && from_sb_expansion < expanding_macro)
444 ++logical_input_line;
445 }
446
447 /* Tells us what the new logical line number and file are.
448 If the line_number is -1, we don't change the current logical line
449 number.
450 If fname is NULL, we don't change the current logical file name, unless
451 bit 3 of flags is set.
452 Returns nonzero if the filename actually changes. */
453
454 void
new_logical_line_flags(const char * fname,int line_number,int flags)455 new_logical_line_flags (const char *fname, /* DON'T destroy it! We point to it! */
456 int line_number,
457 int flags)
458 {
459 switch (flags)
460 {
461 case 0:
462 break;
463 case 1:
464 if (line_number != -1)
465 abort ();
466 break;
467 case 1 << 1:
468 case 1 << 2:
469 /* FIXME: we could check that include nesting is correct. */
470 break;
471 case 1 << 3:
472 if (line_number < 0 || fname != NULL || next_saved_file == NULL)
473 abort ();
474 /* PR gas/16908 workaround: Ignore updates when nested inside a macro
475 expansion. */
476 if (from_sb_expansion == expanding_nested)
477 return;
478 if (next_saved_file->logical_input_file)
479 fname = next_saved_file->logical_input_file;
480 else
481 fname = next_saved_file->physical_input_file;
482 break;
483 default:
484 abort ();
485 }
486
487 if (line_number >= 0)
488 logical_input_line = line_number;
489 else if (line_number == -1 && fname && !*fname && (flags & (1 << 2)))
490 {
491 logical_input_file = physical_input_file;
492 logical_input_line = physical_input_line;
493 fname = NULL;
494 }
495
496 if (fname
497 && (logical_input_file == NULL
498 || filename_cmp (logical_input_file, fname)))
499 logical_input_file = fname;
500
501 /* When encountering file or line changes inside a macro, arrange for
502 bump_line_counters() to henceforth increment the logical line number
503 again, just like it does when expanding repeats. See as_where() for
504 why changing file or line alone doesn't alter expansion mode. */
505 if (from_sb_expansion == expanding_macro
506 && logical_input_file != NULL
507 && logical_input_line != -1u)
508 from_sb_expansion = expanding_repeat;
509 }
510
511 void
new_logical_line(const char * fname,int line_number)512 new_logical_line (const char *fname, int line_number)
513 {
514 new_logical_line_flags (fname, line_number, 0);
515 }
516
517
518 /* Return the current physical input file name and line number, if known */
519
520 const char *
as_where_physical(unsigned int * linep)521 as_where_physical (unsigned int *linep)
522 {
523 if (physical_input_file != NULL)
524 {
525 if (linep != NULL)
526 *linep = physical_input_line;
527 return physical_input_file;
528 }
529
530 if (linep != NULL)
531 *linep = 0;
532 return NULL;
533 }
534
535 /* Return the current file name and line number. */
536
537 const char *
as_where(unsigned int * linep)538 as_where (unsigned int *linep)
539 {
540 if (logical_input_file != NULL
541 && (linep == NULL || logical_input_line != -1u))
542 {
543 if (linep != NULL)
544 *linep = logical_input_line;
545 return logical_input_file;
546 }
547
548 return as_where_physical (linep);
549 }
550
551