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
   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 "input-file.h"
  25 #include "sb.h"
  26 #include "listing.h"
  27
  28 /*
  29  * O/S independent module to supply buffers of sanitised source code
  30  * to rest of assembler.  We get sanitised input data of arbitrary length.
  31  * We break these buffers on line boundaries, recombine pieces that
  32  * were broken across buffers, and return a buffer of full lines to
  33  * the caller.
  34  * The last partial line begins the next buffer we build and return to caller.
  35  * The buffer returned to caller is preceded by BEFORE_STRING and followed
  36  * by AFTER_STRING, as sentinels. The last character before AFTER_STRING
  37  * is a newline.
  38  * Also looks after line numbers, for e.g. error messages.
  39  */
  40
  41 /*
  42  * We don't care how filthy our buffers are, but our callers assume
  43  * that the following sanitation has already been done.
  44  *
  45  * No comments, reduce a comment to a space.
  46  * Reduce a tab to a space unless it is 1st char of line.
  47  * All multiple tabs and spaces collapsed into 1 char. Tab only
  48  *   legal if 1st char of line.
  49  * # line file statements converted to .line x;.file y; statements.
  50  * Escaped newlines at end of line: remove them but add as many newlines
  51  *   to end of statement as you removed in the middle, to synch line numbers.
  52  */
  53 \f
  54 #define BEFORE_STRING ("\n")
  55 #define AFTER_STRING ("\0")     /* memcpy of 0 chars might choke.  */
  56 #define BEFORE_SIZE (1)
  57 #define AFTER_SIZE  (1)
  58
  59 #ifndef TC_EOL_IN_INSN
  60 #define TC_EOL_IN_INSN(P) 0
  61 #endif
  62
  63 static char *buffer_start;      /*->1st char of full buffer area.  */
  64 static char *partial_where;     /*->after last full line in buffer.  */
  65 static int partial_size;        /* >=0. Number of chars in partial line in buffer.  */
  66
  67 /* Because we need AFTER_STRING just after last full line, it clobbers
  68    1st part of partial line. So we preserve 1st part of partial line
  69    here.  */
  70 static char save_source[AFTER_SIZE];
  71
  72 /* What is the largest size buffer that input_file_give_next_buffer()
  73    could return to us?  */
  74 static unsigned int buffer_length;
  75
  76 /* The index into an sb structure we are reading from.  -1 if none.  */
  77 static int 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 int from_sb_is_expansion = 1;
  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 char *physical_input_file;
 100 static char *logical_input_file;
 101
 102 typedef unsigned int line_numberT;      /* 1-origin line number in a source file.  */
 103 /* A line ends in '\n' or eof.  */
 104
 105 static line_numberT 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   unsigned int        buffer_length;
 115   char *              physical_input_file;
 116   char *              logical_input_file;
 117   line_numberT        physical_input_line;
 118   int                 logical_input_line;
 119   int                 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 }
 307
 308 char *
 309 input_scrub_next_buffer (char **bufp)
 310 {
 311   register char *limit;         /*->just after last char of buffer.  */
 312
 313   if (sb_index >= 0)
 314     {
 315       if (sb_index >= from_sb.len)
 316         {
 317           sb_kill (&from_sb);
 318           if (from_sb_is_expansion
 319               )
 320             {
 321               cond_finish_check (macro_nest);
 322 #ifdef md_macro_end
 323               /* Allow the target to clean up per-macro expansion
 324                  data.  */
 325               md_macro_end ();
 326 #endif
 327             }
 328           --macro_nest;
 329           partial_where = NULL;
 330           if (next_saved_file != NULL)
 331             *bufp = input_scrub_pop (next_saved_file);
 332           return partial_where;
 333         }
 334
 335       partial_where = from_sb.ptr + from_sb.len;
 336       partial_size = 0;
 337       *bufp = from_sb.ptr + sb_index;
 338       sb_index = from_sb.len;
 339       return partial_where;
 340     }
 341
 342   *bufp = buffer_start + BEFORE_SIZE;
 343
 344   if (partial_size)
 345     {
 346       memcpy (buffer_start + BEFORE_SIZE, partial_where,
 347               (unsigned int) partial_size);
 348       memcpy (buffer_start + BEFORE_SIZE, save_source, AFTER_SIZE);
 349     }
 350   limit = input_file_give_next_buffer (buffer_start
 351                                        + BEFORE_SIZE
 352                                        + partial_size);
 353   if (limit)
 354     {
 355       register char *p;         /* Find last newline.  */
 356       /* Terminate the buffer to avoid confusing TC_EOL_IN_INSN.  */
 357       *limit = '\0';
 358       for (p = limit - 1; *p != '\n' || TC_EOL_IN_INSN (p); --p)
 359         ;
 360       ++p;
 361
 362       while (p <= buffer_start + BEFORE_SIZE)
 363         {
 364           int limoff;
 365
 366           limoff = limit - buffer_start;
 367           buffer_length += input_file_buffer_size ();
 368           buffer_start = (char *) xrealloc (buffer_start,
 369                                             (BEFORE_SIZE
 370                                              + 2 * buffer_length
 371                                              + AFTER_SIZE));
 372           *bufp = buffer_start + BEFORE_SIZE;
 373           limit = input_file_give_next_buffer (buffer_start + limoff);
 374
 375           if (limit == NULL)
 376             {
 377               as_warn (_("partial line at end of file ignored"));
 378               partial_where = NULL;
 379               if (next_saved_file)
 380                 *bufp = input_scrub_pop (next_saved_file);
 381               return NULL;
 382             }
 383
 384           /* Terminate the buffer to avoid confusing TC_EOL_IN_INSN.  */
 385           *limit = '\0';
 386           for (p = limit - 1; *p != '\n' || TC_EOL_IN_INSN (p); --p)
 387             ;
 388           ++p;
 389         }
 390
 391       partial_where = p;
 392       partial_size = limit - p;
 393       memcpy (save_source, partial_where, (int) AFTER_SIZE);
 394       memcpy (partial_where, AFTER_STRING, (int) AFTER_SIZE);
 395     }
 396   else
 397     {
 398       partial_where = 0;
 399       if (partial_size > 0)
 400         {
 401           as_warn (_("partial line at end of file ignored"));
 402         }
 403
 404       /* Tell the listing we've finished the file.  */
 405       LISTING_EOF ();
 406
 407       /* If we should pop to another file at EOF, do it.  */
 408       if (next_saved_file)
 409         {
 410           *bufp = input_scrub_pop (next_saved_file);    /* Pop state */
 411           /* partial_where is now correct to return, since we popped it.  */
 412         }
 413     }
 414   return (partial_where);
 415 }
 416 \f
 417 /* The remaining part of this file deals with line numbers, error
 418    messages and so on.  Return TRUE if we opened any file.  */
 419
 420 int
 421 seen_at_least_1_file (void)
 422 {
 423   return (physical_input_file != NULL);
 424 }
 425
 426 void
 427 bump_line_counters (void)
 428 {
 429   if (sb_index < 0)
 430     {
 431       ++physical_input_line;
 432       if (logical_input_line >= 0)
 433         ++logical_input_line;
 434     }
 435 }
 436 \f
 437 /* Tells us what the new logical line number and file are.
 438    If the line_number is -1, we don't change the current logical line
 439    number.  If it is -2, we decrement the logical line number (this is
 440    to support the .appfile pseudo-op inserted into the stream by
 441    do_scrub_chars).
 442    If the fname is NULL, we don't change the current logical file name.
 443    Returns nonzero if the filename actually changes.  */
 444
 445 int
 446 new_logical_line_flags (char *fname, /* DON'T destroy it!  We point to it!  */
 447                         int line_number,
 448                         int flags)
 449 {
 450   switch (flags)
 451     {
 452     case 0:
 453       break;
 454     case 1:
 455       if (line_number != -1)
 456         abort ();
 457       break;
 458     case 1 << 1:
 459     case 1 << 2:
 460       /* FIXME: we could check that include nesting is correct.  */
 461       break;
 462     default:
 463       abort ();
 464     }
 465
 466   if (line_number >= 0)
 467     logical_input_line = line_number;
 468   else if (line_number == -1 && fname && !*fname && (flags & (1 << 2)))
 469     {
 470       logical_input_file = physical_input_file;
 471       logical_input_line = physical_input_line;
 472       fname = NULL;
 473     }
 474
 475   if (fname
 476       && (logical_input_file == NULL
 477           || strcmp (logical_input_file, fname)))
 478     {
 479       logical_input_file = fname;
 480       return 1;
 481     }
 482   else
 483     return 0;
 484 }
 485
 486 int
 487 new_logical_line (char *fname, int line_number)
 488 {
 489   return new_logical_line_flags (fname, line_number, 0);
 490 }
 491
 492 \f
 493 /* Return the current file name and line number.
 494    namep should be char * const *, but there are compilers which screw
 495    up declarations like that, and it's easier to avoid it.  */
 496
 497 void
 498 as_where (char **namep, unsigned int *linep)
 499 {
 500   if (logical_input_file != NULL
 501       && (linep == NULL || logical_input_line >= 0))
 502     {
 503       *namep = logical_input_file;
 504       if (linep != NULL)
 505         *linep = logical_input_line;
 506     }
 507   else if (physical_input_file != NULL)
 508     {
 509       *namep = physical_input_file;
 510       if (linep != NULL)
 511         *linep = physical_input_line;
 512     }
 513   else
 514     {
 515       *namep = 0;
 516       if (linep != NULL)
 517         *linep = 0;
 518     }
 519 }