gas/input-scrub.c

   1 /* input_scrub.c - Break up input buffers into whole numbers of lines.
   2    Copyright 1987, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
   3    2000, 2001, 2003, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012
   4    Free Software Foundation, Inc.
   5
   6    This file is part of GAS, the GNU Assembler.
   7
   8    GAS is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 3, or (at your option)
  11    any later version.
  12
  13    GAS is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with GAS; see the file COPYING.  If not, write to the Free
  20    Software Foundation, 51 Franklin Street - Fifth Floor, Boston, MA
  21    02110-1301, USA.  */
  22
  23 #include "as.h"
  24 #include "filenames.h"
  25 #include "input-file.h"
  26 #include "sb.h"
  27 #include "listing.h"
  28
  29 /*
  30  * O/S independent module to supply buffers of sanitised source code
  31  * to rest of assembler.  We get sanitised input data of arbitrary length.
  32  * We break these buffers on line boundaries, recombine pieces that
  33  * were broken across buffers, and return a buffer of full lines to
  34  * the caller.
  35  * The last partial line begins the next buffer we build and return to caller.
  36  * The buffer returned to caller is preceded by BEFORE_STRING and followed
  37  * by AFTER_STRING, as sentinels. The last character before AFTER_STRING
  38  * is a newline.
  39  * Also looks after line numbers, for e.g. error messages.
  40  */
  41
  42 /*
  43  * We don't care how filthy our buffers are, but our callers assume
  44  * that the following sanitation has already been done.
  45  *
  46  * No comments, reduce a comment to a space.
  47  * Reduce a tab to a space unless it is 1st char of line.
  48  * All multiple tabs and spaces collapsed into 1 char. Tab only
  49  *   legal if 1st char of line.
  50  * # line file statements converted to .line x;.file y; statements.
  51  * Escaped newlines at end of line: remove them but add as many newlines
  52  *   to end of statement as you removed in the middle, to synch line numbers.
  53  */
  54 \f
  55 #define BEFORE_STRING ("\n")
  56 #define AFTER_STRING ("\0")     /* memcpy of 0 chars might choke.  */
  57 #define BEFORE_SIZE (1)
  58 #define AFTER_SIZE  (1)
  59
  60 #ifndef TC_EOL_IN_INSN
  61 #define TC_EOL_IN_INSN(P) 0
  62 #endif
  63
  64 static char *buffer_start;      /*->1st char of full buffer area.  */
  65 static char *partial_where;     /*->after last full line in buffer.  */
  66 static int partial_size;        /* >=0. Number of chars in partial line in buffer.  */
  67
  68 /* Because we need AFTER_STRING just after last full line, it clobbers
  69    1st part of partial line. So we preserve 1st part of partial line
  70    here.  */
  71 static char save_source[AFTER_SIZE];
  72
  73 /* What is the largest size buffer that input_file_give_next_buffer()
  74    could return to us?  */
  75 static unsigned int buffer_length;
  76
  77 /* The index into an sb structure we are reading from.  -1 if none.  */
  78 static size_t sb_index = -1;
  79
  80 /* If we are reading from an sb structure, this is it.  */
  81 static sb from_sb;
  82
  83 /* Should we do a conditional check on from_sb? */
  84 static int from_sb_is_expansion = 1;
  85
  86 /* The number of nested sb structures we have included.  */
  87 int macro_nest;
  88
  89 /* We can have more than one source file open at once, though the info for all
  90    but the latest one are saved off in a struct input_save.  These files remain
  91    open, so we are limited by the number of open files allowed by the
  92    underlying OS. We may also sequentially read more than one source file in an
  93    assembly.  */
  94
  95 /* We must track the physical file and line number for error messages. We also
  96    track a "logical" file and line number corresponding to (C?)  compiler
  97    source line numbers.  Whenever we open a file we must fill in
  98    physical_input_file. So if it is NULL we have not opened any files yet.  */
  99
 100 static char *physical_input_file;
 101 static char *logical_input_file;
 102
 103 /* 1-origin line number in a source file.  */
 104 /* A line ends in '\n' or eof.  */
 105 static unsigned int physical_input_line;
 106 static int logical_input_line;
 107
 108 /* Struct used to save the state of the input handler during include files */
 109 struct input_save {
 110   char *              buffer_start;
 111   char *              partial_where;
 112   int                 partial_size;
 113   char                save_source[AFTER_SIZE];
 114   size_t              buffer_length;
 115   char *              physical_input_file;
 116   char *              logical_input_file;
 117   unsigned int        physical_input_line;
 118   int                 logical_input_line;
 119   size_t              sb_index;
 120   sb                  from_sb;
 121   int                 from_sb_is_expansion; /* Should we do a conditional check?  */
 122   struct input_save * next_saved_file;  /* Chain of input_saves.  */
 123   char *              input_file_save;  /* Saved state of input routines.  */
 124   char *              saved_position;   /* Caller's saved position in buf.  */
 125 };
 126
 127 static struct input_save *input_scrub_push (char *saved_position);
 128 static char *input_scrub_pop (struct input_save *arg);
 129
 130 /* Saved information about the file that .include'd this one.  When we hit EOF,
 131    we automatically pop to that file.  */
 132
 133 static struct input_save *next_saved_file;
 134
 135 /* Push the state of input reading and scrubbing so that we can #include.
 136    The return value is a 'void *' (fudged for old compilers) to a save
 137    area, which can be restored by passing it to input_scrub_pop().  */
 138
 139 static struct input_save *
 140 input_scrub_push (char *saved_position)
 141 {
 142   register struct input_save *saved;
 143
 144   saved = (struct input_save *) xmalloc (sizeof *saved);
 145
 146   saved->saved_position = saved_position;
 147   saved->buffer_start = buffer_start;
 148   saved->partial_where = partial_where;
 149   saved->partial_size = partial_size;
 150   saved->buffer_length = buffer_length;
 151   saved->physical_input_file = physical_input_file;
 152   saved->logical_input_file = logical_input_file;
 153   saved->physical_input_line = physical_input_line;
 154   saved->logical_input_line = logical_input_line;
 155   saved->sb_index = sb_index;
 156   saved->from_sb = from_sb;
 157   saved->from_sb_is_expansion = from_sb_is_expansion;
 158   memcpy (saved->save_source, save_source, sizeof (save_source));
 159   saved->next_saved_file = next_saved_file;
 160   saved->input_file_save = input_file_push ();
 161
 162   input_file_begin ();          /* Reinitialize! */
 163   logical_input_line = -1;
 164   logical_input_file = (char *) NULL;
 165   buffer_length = input_file_buffer_size ();
 166   sb_index = -1;
 167
 168   buffer_start = (char *) xmalloc ((BEFORE_SIZE + buffer_length
 169                                     + buffer_length + AFTER_SIZE));
 170   memcpy (buffer_start, BEFORE_STRING, (int) BEFORE_SIZE);
 171
 172   return saved;
 173 }
 174
 175 static char *
 176 input_scrub_pop (struct input_save *saved)
 177 {
 178   char *saved_position;
 179
 180   input_scrub_end ();           /* Finish off old buffer */
 181
 182   input_file_pop (saved->input_file_save);
 183   saved_position = saved->saved_position;
 184   buffer_start = saved->buffer_start;
 185   buffer_length = saved->buffer_length;
 186   physical_input_file = saved->physical_input_file;
 187   logical_input_file = saved->logical_input_file;
 188   physical_input_line = saved->physical_input_line;
 189   logical_input_line = saved->logical_input_line;
 190   sb_index = saved->sb_index;
 191   from_sb = saved->from_sb;
 192   from_sb_is_expansion = saved->from_sb_is_expansion;
 193   partial_where = saved->partial_where;
 194   partial_size = saved->partial_size;
 195   next_saved_file = saved->next_saved_file;
 196   memcpy (save_source, saved->save_source, sizeof (save_source));
 197
 198   free (saved);
 199   return saved_position;
 200 }
 201 \f
 202 void
 203 input_scrub_begin (void)
 204 {
 205   know (strlen (BEFORE_STRING) == BEFORE_SIZE);
 206   know (strlen (AFTER_STRING) == AFTER_SIZE
 207         || (AFTER_STRING[0] == '\0' && AFTER_SIZE == 1));
 208
 209   input_file_begin ();
 210
 211   buffer_length = input_file_buffer_size ();
 212
 213   buffer_start = (char *) xmalloc ((BEFORE_SIZE + buffer_length
 214                                     + buffer_length + AFTER_SIZE));
 215   memcpy (buffer_start, BEFORE_STRING, (int) BEFORE_SIZE);
 216
 217   /* Line number things.  */
 218   logical_input_line = -1;
 219   logical_input_file = (char *) NULL;
 220   physical_input_file = NULL;   /* No file read yet.  */
 221   next_saved_file = NULL;       /* At EOF, don't pop to any other file */
 222   do_scrub_begin (flag_m68k_mri);
 223 }
 224
 225 void
 226 input_scrub_end (void)
 227 {
 228   if (buffer_start)
 229     {
 230       free (buffer_start);
 231       buffer_start = 0;
 232       input_file_end ();
 233     }
 234 }
 235
 236 /* Start reading input from a new file.
 237    Return start of caller's part of buffer.  */
 238
 239 char *
 240 input_scrub_new_file (char *filename)
 241 {
 242   input_file_open (filename, !flag_no_comments);
 243   physical_input_file = filename[0] ? filename : _("{standard input}");
 244   physical_input_line = 0;
 245
 246   partial_size = 0;
 247   return (buffer_start + BEFORE_SIZE);
 248 }
 249
 250 /* Include a file from the current file.  Save our state, cause it to
 251    be restored on EOF, and begin handling a new file.  Same result as
 252    input_scrub_new_file.  */
 253
 254 char *
 255 input_scrub_include_file (char *filename, char *position)
 256 {
 257   next_saved_file = input_scrub_push (position);
 258   return input_scrub_new_file (filename);
 259 }
 260
 261 /* Start getting input from an sb structure.  This is used when
 262    expanding a macro.  */
 263
 264 void
 265 input_scrub_include_sb (sb *from, char *position, int is_expansion)
 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   sb_new (&from_sb);
 281   from_sb_is_expansion = is_expansion;
 282   if (from->len >= 1 && from->ptr[0] != '\n')
 283     {
 284       /* Add the sentinel required by read.c.  */
 285       sb_add_char (&from_sb, '\n');
 286     }
 287   sb_scrub_and_add_sb (&from_sb, from);
 288
 289   /* Make sure the parser looks at defined contents when it scans for
 290      e.g. end-of-line at the end of a macro.  */
 291   sb_add_char (&from_sb, 0);
 292   from_sb.len--;
 293
 294   sb_index = 1;
 295
 296   /* These variables are reset by input_scrub_push.  Restore them
 297      since we are, after all, still at the same point in the file.  */
 298   logical_input_line = next_saved_file->logical_input_line;
 299   logical_input_file = next_saved_file->logical_input_file;
 300 }
 301
 302 void
 303 input_scrub_close (void)
 304 {
 305   input_file_close ();
 306   physical_input_line = 0;
 307   logical_input_line = -1;
 308 }
 309
 310 char *
 311 input_scrub_next_buffer (char **bufp)
 312 {
 313   register char *limit;         /*->just after last char of buffer.  */
 314
 315   if (sb_index != (size_t) -1)
 316     {
 317       if (sb_index >= from_sb.len)
 318         {
 319           sb_kill (&from_sb);
 320           if (from_sb_is_expansion)
 321             {
 322               cond_finish_check (macro_nest);
 323 #ifdef md_macro_end
 324               /* Allow the target to clean up per-macro expansion
 325                  data.  */
 326               md_macro_end ();
 327 #endif
 328             }
 329           --macro_nest;
 330           partial_where = NULL;
 331           if (next_saved_file != NULL)
 332             *bufp = input_scrub_pop (next_saved_file);
 333           return partial_where;
 334         }
 335
 336       partial_where = from_sb.ptr + from_sb.len;
 337       partial_size = 0;
 338       *bufp = from_sb.ptr + sb_index;
 339       sb_index = from_sb.len;
 340       return partial_where;
 341     }
 342
 343   *bufp = buffer_start + BEFORE_SIZE;
 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   limit = input_file_give_next_buffer (buffer_start
 352                                        + BEFORE_SIZE
 353                                        + partial_size);
 354   if (limit)
 355     {
 356       register char *p;         /* Find last newline.  */
 357       /* Terminate the buffer to avoid confusing TC_EOL_IN_INSN.  */
 358       *limit = '\0';
 359       for (p = limit - 1; *p != '\n' || TC_EOL_IN_INSN (p); --p)
 360         ;
 361       ++p;
 362
 363       while (p <= buffer_start + BEFORE_SIZE)
 364         {
 365           int limoff;
 366
 367           limoff = limit - buffer_start;
 368           buffer_length += input_file_buffer_size ();
 369           buffer_start = (char *) xrealloc (buffer_start,
 370                                             (BEFORE_SIZE
 371                                              + 2 * buffer_length
 372                                              + AFTER_SIZE));
 373           *bufp = buffer_start + BEFORE_SIZE;
 374           limit = input_file_give_next_buffer (buffer_start + limoff);
 375
 376           if (limit == NULL)
 377             {
 378               as_warn (_("partial line at end of file ignored"));
 379               partial_where = NULL;
 380               if (next_saved_file)
 381                 *bufp = input_scrub_pop (next_saved_file);
 382               return NULL;
 383             }
 384
 385           /* Terminate the buffer to avoid confusing TC_EOL_IN_INSN.  */
 386           *limit = '\0';
 387           for (p = limit - 1; *p != '\n' || TC_EOL_IN_INSN (p); --p)
 388             ;
 389           ++p;
 390         }
 391
 392       partial_where = p;
 393       partial_size = limit - p;
 394       memcpy (save_source, partial_where, (int) AFTER_SIZE);
 395       memcpy (partial_where, AFTER_STRING, (int) AFTER_SIZE);
 396     }
 397   else
 398     {
 399       partial_where = 0;
 400       if (partial_size > 0)
 401         {
 402           as_warn (_("partial line at end of file ignored"));
 403         }
 404
 405       /* Tell the listing we've finished the file.  */
 406       LISTING_EOF ();
 407
 408       /* If we should pop to another file at EOF, do it.  */
 409       if (next_saved_file)
 410         {
 411           *bufp = input_scrub_pop (next_saved_file);    /* Pop state */
 412           /* partial_where is now correct to return, since we popped it.  */
 413         }
 414     }
 415   return (partial_where);
 416 }
 417 \f
 418 /* The remaining part of this file deals with line numbers, error
 419    messages and so on.  Return TRUE if we opened any file.  */
 420
 421 int
 422 seen_at_least_1_file (void)
 423 {
 424   return (physical_input_file != NULL);
 425 }
 426
 427 void
 428 bump_line_counters (void)
 429 {
 430   if (sb_index == (size_t) -1)
 431     {
 432       ++physical_input_line;
 433       if (logical_input_line >= 0)
 434         ++logical_input_line;
 435     }
 436 }
 437 \f
 438 /* Tells us what the new logical line number and file are.
 439    If the line_number is -1, we don't change the current logical line
 440    number.  If it is -2, we decrement the logical line number (this is
 441    to support the .appfile pseudo-op inserted into the stream by
 442    do_scrub_chars).
 443    If the fname is NULL, we don't change the current logical file name.
 444    Returns nonzero if the filename actually changes.  */
 445
 446 int
 447 new_logical_line_flags (char *fname, /* DON'T destroy it!  We point to it!  */
 448                         int line_number,
 449                         int flags)
 450 {
 451   switch (flags)
 452     {
 453     case 0:
 454       break;
 455     case 1:
 456       if (line_number != -1)
 457         abort ();
 458       break;
 459     case 1 << 1:
 460     case 1 << 2:
 461       /* FIXME: we could check that include nesting is correct.  */
 462       break;
 463     default:
 464       abort ();
 465     }
 466
 467   if (line_number >= 0)
 468     logical_input_line = line_number;
 469   else if (line_number == -1 && fname && !*fname && (flags & (1 << 2)))
 470     {
 471       logical_input_file = physical_input_file;
 472       logical_input_line = physical_input_line;
 473       fname = NULL;
 474     }
 475
 476   if (fname
 477       && (logical_input_file == NULL
 478           || filename_cmp (logical_input_file, fname)))
 479     {
 480       logical_input_file = fname;
 481       return 1;
 482     }
 483   else
 484     return 0;
 485 }
 486
 487 int
 488 new_logical_line (char *fname, int line_number)
 489 {
 490   return new_logical_line_flags (fname, line_number, 0);
 491 }
 492
 493 \f
 494 /* Return the current file name and line number.
 495    namep should be char * const *, but there are compilers which screw
 496    up declarations like that, and it's easier to avoid it.  */
 497
 498 void
 499 as_where (char **namep, unsigned int *linep)
 500 {
 501   if (logical_input_file != NULL
 502       && (linep == NULL || logical_input_line >= 0))
 503     {
 504       *namep = logical_input_file;
 505       if (linep != NULL)
 506         *linep = logical_input_line;
 507     }
 508   else if (physical_input_file != NULL)
 509     {
 510       *namep = physical_input_file;
 511       if (linep != NULL)
 512         *linep = physical_input_line;
 513     }
 514   else
 515     {
 516       *namep = 0;
 517       if (linep != NULL)
 518         *linep = 0;
 519     }
 520 }