aboutsummaryrefslogtreecommitdiff
path: root/gas/input-scrub.c
blob: f5f2af214a2424194ea4e581f20d0ea4da5896e1 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
/* input_scrub.c - Break up input buffers into whole numbers of lines.
   Copyright (C) 1987-2016 Free Software Foundation, Inc.

   This file is part of GAS, the GNU Assembler.

   GAS is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3, or (at your option)
   any later version.

   GAS is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with GAS; see the file COPYING.  If not, write to the Free
   Software Foundation, 51 Franklin Street - Fifth Floor, Boston, MA
   02110-1301, USA.  */

#include "as.h"
#include "filenames.h"
#include "input-file.h"
#include "sb.h"
#include "listing.h"

/*
 * O/S independent module to supply buffers of sanitised source code
 * to rest of assembler.  We get sanitised input data of arbitrary length.
 * We break these buffers on line boundaries, recombine pieces that
 * were broken across buffers, and return a buffer of full lines to
 * the caller.
 * The last partial line begins the next buffer we build and return to caller.
 * The buffer returned to caller is preceded by BEFORE_STRING and followed
 * by AFTER_STRING, as sentinels. The last character before AFTER_STRING
 * is a newline.
 * Also looks after line numbers, for e.g. error messages.
 */

/*
 * We don't care how filthy our buffers are, but our callers assume
 * that the following sanitation has already been done.
 *
 * No comments, reduce a comment to a space.
 * Reduce a tab to a space unless it is 1st char of line.
 * All multiple tabs and spaces collapsed into 1 char. Tab only
 *   legal if 1st char of line.
 * # line file statements converted to .line x;.file y; statements.
 * Escaped newlines at end of line: remove them but add as many newlines
 *   to end of statement as you removed in the middle, to synch line numbers.
 */

#define BEFORE_STRING ("\n")
#define AFTER_STRING ("\0")	/* memcpy of 0 chars might choke.  */
#define BEFORE_SIZE (1)
#define AFTER_SIZE  (1)

#ifndef TC_EOL_IN_INSN
#define TC_EOL_IN_INSN(P) 0
#endif

static char *buffer_start;	/*->1st char of full buffer area.  */
static char *partial_where;	/*->after last full line in buffer.  */
static size_t partial_size;	/* >=0. Number of chars in partial line in buffer.  */

/* Because we need AFTER_STRING just after last full line, it clobbers
   1st part of partial line. So we preserve 1st part of partial line
   here.  */
static char save_source[AFTER_SIZE];

/* The size of the input buffer we concatenate
   input_file_give_next_buffer chunks into.  Excludes the BEFORE and
   AFTER counts.  */
static size_t buffer_length;

/* The index into an sb structure we are reading from.  -1 if none.  */
static size_t sb_index = -1;

/* If we are reading from an sb structure, this is it.  */
static sb from_sb;

/* Should we do a conditional check on from_sb? */
static int from_sb_is_expansion = 1;

/* The number of nested sb structures we have included.  */
int macro_nest;

/* We can have more than one source file open at once, though the info for all
   but the latest one are saved off in a struct input_save.  These files remain
   open, so we are limited by the number of open files allowed by the
   underlying OS. We may also sequentially read more than one source file in an
   assembly.  */

/* We must track the physical file and line number for error messages. We also
   track a "logical" file and line number corresponding to (C?)  compiler
   source line numbers.  Whenever we open a file we must fill in
   physical_input_file. So if it is NULL we have not opened any files yet.  */

static const char *physical_input_file;
static const char *logical_input_file;

/* 1-origin line number in a source file.  */
/* A line ends in '\n' or eof.  */
static unsigned int physical_input_line;
static int logical_input_line;

/* Struct used to save the state of the input handler during include files */
struct input_save {
  char *              buffer_start;
  char *              partial_where;
  size_t              partial_size;
  char                save_source[AFTER_SIZE];
  size_t              buffer_length;
  const char *              physical_input_file;
  const char *              logical_input_file;
  unsigned int        physical_input_line;
  int                 logical_input_line;
  size_t              sb_index;
  sb                  from_sb;
  int                 from_sb_is_expansion; /* Should we do a conditional check?  */
  struct input_save * next_saved_file;	/* Chain of input_saves.  */
  char *              input_file_save;	/* Saved state of input routines.  */
  char *              saved_position;	/* Caller's saved position in buf.  */
};

static struct input_save *input_scrub_push (char *saved_position);
static char *input_scrub_pop (struct input_save *arg);

/* Saved information about the file that .include'd this one.  When we hit EOF,
   we automatically pop to that file.  */

static struct input_save *next_saved_file;

/* Initialize input buffering.  */

static void
input_scrub_reinit (void)
{
  input_file_begin ();		/* Reinitialize! */
  logical_input_line = -1;
  logical_input_file = NULL;

  buffer_length = input_file_buffer_size () * 2;
  buffer_start = XNEWVEC (char, BEFORE_SIZE + AFTER_SIZE + 1 + buffer_length);
  memcpy (buffer_start, BEFORE_STRING, (int) BEFORE_SIZE);
}

/* Push the state of input reading and scrubbing so that we can #include.
   The return value is a 'void *' (fudged for old compilers) to a save
   area, which can be restored by passing it to input_scrub_pop().  */

static struct input_save *
input_scrub_push (char *saved_position)
{
  struct input_save *saved;

  saved = XNEW (struct input_save);

  saved->saved_position = saved_position;
  saved->buffer_start = buffer_start;
  saved->partial_where = partial_where;
  saved->partial_size = partial_size;
  saved->buffer_length = buffer_length;
  saved->physical_input_file = physical_input_file;
  saved->logical_input_file = logical_input_file;
  saved->physical_input_line = physical_input_line;
  saved->logical_input_line = logical_input_line;
  saved->sb_index = sb_index;
  saved->from_sb = from_sb;
  saved->from_sb_is_expansion = from_sb_is_expansion;
  memcpy (saved->save_source, save_source, sizeof (save_source));
  saved->next_saved_file = next_saved_file;
  saved->input_file_save = input_file_push ();

  sb_index = -1;

  input_scrub_reinit ();

  return saved;
}

static char *
input_scrub_pop (struct input_save *saved)
{
  char *saved_position;

  input_scrub_end ();		/* Finish off old buffer */

  input_file_pop (saved->input_file_save);
  saved_position = saved->saved_position;
  buffer_start = saved->buffer_start;
  buffer_length = saved->buffer_length;
  physical_input_file = saved->physical_input_file;
  logical_input_file = saved->logical_input_file;
  physical_input_line = saved->physical_input_line;
  logical_input_line = saved->logical_input_line;
  sb_index = saved->sb_index;
  from_sb = saved->from_sb;
  from_sb_is_expansion = saved->from_sb_is_expansion;
  partial_where = saved->partial_where;
  partial_size = saved->partial_size;
  next_saved_file = saved->next_saved_file;
  memcpy (save_source, saved->save_source, sizeof (save_source));

  free (saved);
  return saved_position;
}

void
input_scrub_begin (void)
{
  know (strlen (BEFORE_STRING) == BEFORE_SIZE);
  know (strlen (AFTER_STRING) == AFTER_SIZE
	|| (AFTER_STRING[0] == '\0' && AFTER_SIZE == 1));

  physical_input_file = NULL;	/* No file read yet.  */
  next_saved_file = NULL;	/* At EOF, don't pop to any other file */
  input_scrub_reinit ();
  do_scrub_begin (flag_m68k_mri);
}

void
input_scrub_end (void)
{
  if (buffer_start)
    {
      free (buffer_start);
      buffer_start = 0;
      input_file_end ();
    }
}

/* Start reading input from a new file.
   Return start of caller's part of buffer.  */

char *
input_scrub_new_file (const char *filename)
{
  input_file_open (filename, !flag_no_comments);
  physical_input_file = filename[0] ? filename : _("{standard input}");
  physical_input_line = 0;

  partial_size = 0;
  return (buffer_start + BEFORE_SIZE);
}

/* Include a file from the current file.  Save our state, cause it to
   be restored on EOF, and begin handling a new file.  Same result as
   input_scrub_new_file.  */

char *
input_scrub_include_file (const char *filename, char *position)
{
  next_saved_file = input_scrub_push (position);
  return input_scrub_new_file (filename);
}

/* Start getting input from an sb structure.  This is used when
   expanding a macro.  */

void
input_scrub_include_sb (sb *from, char *position, int is_expansion)
{
  int newline;

  if (macro_nest > max_macro_nest)
    as_fatal (_("macros nested too deeply"));
  ++macro_nest;

#ifdef md_macro_start
  if (is_expansion)
    {
      md_macro_start ();
    }
#endif

  next_saved_file = input_scrub_push (position);

  /* Allocate sufficient space: from->len + optional newline.  */
  newline = from->len >= 1 && from->ptr[0] != '\n';
  sb_build (&from_sb, from->len + newline);
  from_sb_is_expansion = is_expansion;
  if (newline)
    {
      /* Add the sentinel required by read.c.  */
      sb_add_char (&from_sb, '\n');
    }
  sb_scrub_and_add_sb (&from_sb, from);

  /* Make sure the parser looks at defined contents when it scans for
     e.g. end-of-line at the end of a macro.  */
  sb_terminate (&from_sb);

  sb_index = 1;

  /* These variables are reset by input_scrub_push.  Restore them
     since we are, after all, still at the same point in the file.  */
  logical_input_line = next_saved_file->logical_input_line;
  logical_input_file = next_saved_file->logical_input_file;
}

void
input_scrub_close (void)
{
  input_file_close ();
  physical_input_line = 0;
  logical_input_line = -1;
}

char *
input_scrub_next_buffer (char **bufp)
{
  char *limit;		/*->just after last char of buffer.  */

  if (sb_index != (size_t) -1)
    {
      if (sb_index >= from_sb.len)
	{
	  sb_kill (&from_sb);
	  if (from_sb_is_expansion)
	    {
	      cond_finish_check (macro_nest);
#ifdef md_macro_end
	      /* Allow the target to clean up per-macro expansion
	         data.  */
	      md_macro_end ();
#endif
	    }
	  --macro_nest;
	  partial_where = NULL;
	  partial_size = 0;
	  if (next_saved_file != NULL)
	    *bufp = input_scrub_pop (next_saved_file);
	  return partial_where;
	}

      partial_where = from_sb.ptr + from_sb.len;
      partial_size = 0;
      *bufp = from_sb.ptr + sb_index;
      sb_index = from_sb.len;
      return partial_where;
    }

  if (partial_size)
    {
      memmove (buffer_start + BEFORE_SIZE, partial_where, partial_size);
      memcpy (buffer_start + BEFORE_SIZE, save_source, AFTER_SIZE);
    }

  while (1)
    {
      char *p;
      char *start = buffer_start + BEFORE_SIZE + partial_size;

      *bufp = buffer_start + BEFORE_SIZE;
      limit = input_file_give_next_buffer (start);
      if (!limit)
	{
	  if (!partial_size)
	    /* End of this file.  */
	    break;

	  as_warn (_("end of file not at end of a line; newline inserted"));
	  p = buffer_start + BEFORE_SIZE + partial_size;
	  *p++ = '\n';
	  limit = p;
	}
      else
	{
	  /* Terminate the buffer to avoid confusing TC_EOL_IN_INSN.  */
	  *limit = '\0';

	  /* Find last newline.  */
	  for (p = limit - 1; *p != '\n' || TC_EOL_IN_INSN (p); --p)
	    if (p < start)
	      goto read_more;
	  ++p;
	}

      /* We found a newline in the newly read chars.  */
      partial_where = p;
      partial_size = limit - p;

      /* Save the fragment after that last newline.  */
      memcpy (save_source, partial_where, (int) AFTER_SIZE);
      memcpy (partial_where, AFTER_STRING, (int) AFTER_SIZE);
      return partial_where;

    read_more:
      /* Didn't find a newline.  Read more text.  */
      partial_size = limit - (buffer_start + BEFORE_SIZE);
      if (buffer_length - input_file_buffer_size () < partial_size)
	{
	  /* Increase the buffer when it doesn't have room for the
	     next block of input.  */
	  buffer_length *= 2;
	  buffer_start = XRESIZEVEC (char, buffer_start,
				     (buffer_length
				      + BEFORE_SIZE + AFTER_SIZE + 1));
	}
    }

  /* Tell the listing we've finished the file.  */
  LISTING_EOF ();

  /* If we should pop to another file at EOF, do it.  */
  partial_where = NULL;
  if (next_saved_file)
    *bufp = input_scrub_pop (next_saved_file);

  return partial_where;
}

/* The remaining part of this file deals with line numbers, error
   messages and so on.  Return TRUE if we opened any file.  */

int
seen_at_least_1_file (void)
{
  return (physical_input_file != NULL);
}

void
bump_line_counters (void)
{
  if (sb_index == (size_t) -1)
    {
      ++physical_input_line;
      if (logical_input_line >= 0)
	++logical_input_line;
    }
}

/* Tells us what the new logical line number and file are.
   If the line_number is -1, we don't change the current logical line
   number.  If it is -2, we decrement the logical line number (this is
   to support the .appfile pseudo-op inserted into the stream by
   do_scrub_chars).
   If the fname is NULL, we don't change the current logical file name.
   Returns nonzero if the filename actually changes.  */

int
new_logical_line_flags (const char *fname, /* DON'T destroy it!  We point to it!  */
			int line_number,
			int flags)
{
  switch (flags)
    {
    case 0:
      break;
    case 1:
      if (line_number != -1)
	abort ();
      break;
    case 1 << 1:
    case 1 << 2:
      /* FIXME: we could check that include nesting is correct.  */
      break;
    default:
      abort ();
    }

  if (line_number >= 0)
    logical_input_line = line_number;
  else if (line_number == -1 && fname && !*fname && (flags & (1 << 2)))
    {
      logical_input_file = physical_input_file;
      logical_input_line = physical_input_line;
      fname = NULL;
    }

  if (fname
      && (logical_input_file == NULL
	  || filename_cmp (logical_input_file, fname)))
    {
      logical_input_file = fname;
      return 1;
    }
  else
    return 0;
}

int
new_logical_line (const char *fname, int line_number)
{
  return new_logical_line_flags (fname, line_number, 0);
}


/* Return the current file name and line number.  */

const char *
as_where (unsigned int *linep)
{
  if (logical_input_file != NULL
      && (linep == NULL || logical_input_line >= 0))
    {
      if (linep != NULL)
	*linep = logical_input_line;
      return logical_input_file;
    }
  else if (physical_input_file != NULL)
    {
      if (linep != NULL)
	*linep = physical_input_line;
      return physical_input_file;
    }
  else
    {
      if (linep != NULL)
	*linep = 0;
      return NULL;
    }
}