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, 2006
   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 2, 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 static char *buffer_start;      /*->1st char of full buffer area.  */
  60 static char *partial_where;     /*->after last full line in buffer.  */
  61 static int partial_size;        /* >=0. Number of chars in partial line in buffer.  */
  62
  63 /* Because we need AFTER_STRING just after last full line, it clobbers
  64    1st part of partial line. So we preserve 1st part of partial line
  65    here.  */
  66 static char save_source[AFTER_SIZE];
  67
  68 /* What is the largest size buffer that input_file_give_next_buffer()
  69    could return to us?  */
  70 static unsigned int buffer_length;
  71
  72 /* The index into an sb structure we are reading from.  -1 if none.  */
  73 static int sb_index = -1;
  74
  75 /* If we are reading from an sb structure, this is it.  */
  76 static sb from_sb;
  77
  78 /* Should we do a conditional check on from_sb? */
  79 static int from_sb_is_expansion = 1;
  80
  81 /* The number of nested sb structures we have included.  */
  82 int macro_nest;
  83
  84 /* We can have more than one source file open at once, though the info for all
  85    but the latest one are saved off in a struct input_save.  These files remain
  86    open, so we are limited by the number of open files allowed by the
  87    underlying OS. We may also sequentially read more than one source file in an
  88    assembly.  */
  89
  90 /* We must track the physical file and line number for error messages. We also
  91    track a "logical" file and line number corresponding to (C?)  compiler
  92    source line numbers.  Whenever we open a file we must fill in
  93    physical_input_file. So if it is NULL we have not opened any files yet.  */
  94
  95 static char *physical_input_file;
  96 static char *logical_input_file;
  97
  98 typedef unsigned int line_numberT;      /* 1-origin line number in a source file.  */
  99 /* A line ends in '\n' or eof.  */
 100
 101 static line_numberT physical_input_line;
 102 static int logical_input_line;
 103
 104 /* Struct used to save the state of the input handler during include files */
 105 struct input_save {
 106   char *              buffer_start;
 107   char *              partial_where;
 108   int                 partial_size;
 109   char                save_source[AFTER_SIZE];
 110   unsigned int        buffer_length;
 111   char *              physical_input_file;
 112   char *              logical_input_file;
 113   line_numberT        physical_input_line;
 114   int                 logical_input_line;
 115   int                 sb_index;
 116   sb                  from_sb;
 117   int                 from_sb_is_expansion; /* Should we do a conditional check?  */
 118   struct input_save * next_saved_file;  /* Chain of input_saves.  */
 119   char *              input_file_save;  /* Saved state of input routines.  */
 120   char *              saved_position;   /* Caller's saved position in buf.  */
 121 };
 122
 123 static struct input_save *input_scrub_push (char *saved_position);
 124 static char *input_scrub_pop (struct input_save *arg);
 125
 126 /* Saved information about the file that .include'd this one.  When we hit EOF,
 127    we automatically pop to that file.  */
 128
 129 static struct input_save *next_saved_file;
 130
 131 /* Push the state of input reading and scrubbing so that we can #include.
 132    The return value is a 'void *' (fudged for old compilers) to a save
 133    area, which can be restored by passing it to input_scrub_pop().  */
 134
 135 static struct input_save *
 136 input_scrub_push (char *saved_position)
 137 {
 138   register struct input_save *saved;
 139
 140   saved = (struct input_save *) xmalloc (sizeof *saved);
 141
 142   saved->saved_position = saved_position;
 143   saved->buffer_start = buffer_start;
 144   saved->partial_where = partial_where;
 145   saved->partial_size = partial_size;
 146   saved->buffer_length = buffer_length;
 147   saved->physical_input_file = physical_input_file;
 148   saved->logical_input_file = logical_input_file;
 149   saved->physical_input_line = physical_input_line;
 150   saved->logical_input_line = logical_input_line;
 151   saved->sb_index = sb_index;
 152   saved->from_sb = from_sb;
 153   saved->from_sb_is_expansion = from_sb_is_expansion;
 154   memcpy (saved->save_source, save_source, sizeof (save_source));
 155   saved->next_saved_file = next_saved_file;
 156   saved->input_file_save = input_file_push ();
 157
 158   input_file_begin ();          /* Reinitialize! */
 159   logical_input_line = -1;
 160   logical_input_file = (char *) NULL;
 161   buffer_length = input_file_buffer_size ();
 162   sb_index = -1;
 163
 164   buffer_start = xmalloc ((BEFORE_SIZE + buffer_length + buffer_length + AFTER_SIZE));
 165   memcpy (buffer_start, BEFORE_STRING, (int) BEFORE_SIZE);
 166
 167   return saved;
 168 }
 169
 170 static char *
 171 input_scrub_pop (struct input_save *saved)
 172 {
 173   char *saved_position;
 174
 175   input_scrub_end ();           /* Finish off old buffer */
 176
 177   input_file_pop (saved->input_file_save);
 178   saved_position = saved->saved_position;
 179   buffer_start = saved->buffer_start;
 180   buffer_length = saved->buffer_length;
 181   physical_input_file = saved->physical_input_file;
 182   logical_input_file = saved->logical_input_file;
 183   physical_input_line = saved->physical_input_line;
 184   logical_input_line = saved->logical_input_line;
 185   sb_index = saved->sb_index;
 186   from_sb = saved->from_sb;
 187   from_sb_is_expansion = saved->from_sb_is_expansion;
 188   partial_where = saved->partial_where;
 189   partial_size = saved->partial_size;
 190   next_saved_file = saved->next_saved_file;
 191   memcpy (save_source, saved->save_source, sizeof (save_source));
 192
 193   free (saved);
 194   return saved_position;
 195 }
 196 \f
 197 void
 198 input_scrub_begin (void)
 199 {
 200   know (strlen (BEFORE_STRING) == BEFORE_SIZE);
 201   know (strlen (AFTER_STRING) == AFTER_SIZE
 202         || (AFTER_STRING[0] == '\0' && AFTER_SIZE == 1));
 203
 204   input_file_begin ();
 205
 206   buffer_length = input_file_buffer_size ();
 207
 208   buffer_start = xmalloc ((BEFORE_SIZE + buffer_length + buffer_length + AFTER_SIZE));
 209   memcpy (buffer_start, BEFORE_STRING, (int) BEFORE_SIZE);
 210
 211   /* Line number things.  */
 212   logical_input_line = -1;
 213   logical_input_file = (char *) NULL;
 214   physical_input_file = NULL;   /* No file read yet.  */
 215   next_saved_file = NULL;       /* At EOF, don't pop to any other file */
 216   do_scrub_begin (flag_m68k_mri);
 217 }
 218
 219 void
 220 input_scrub_end (void)
 221 {
 222   if (buffer_start)
 223     {
 224       free (buffer_start);
 225       buffer_start = 0;
 226       input_file_end ();
 227     }
 228 }
 229
 230 /* Start reading input from a new file.
 231    Return start of caller's part of buffer.  */
 232
 233 char *
 234 input_scrub_new_file (char *filename)
 235 {
 236   input_file_open (filename, !flag_no_comments);
 237   physical_input_file = filename[0] ? filename : _("{standard input}");
 238   physical_input_line = 0;
 239
 240   partial_size = 0;
 241   return (buffer_start + BEFORE_SIZE);
 242 }
 243
 244 /* Include a file from the current file.  Save our state, cause it to
 245    be restored on EOF, and begin handling a new file.  Same result as
 246    input_scrub_new_file.  */
 247
 248 char *
 249 input_scrub_include_file (char *filename, char *position)
 250 {
 251   next_saved_file = input_scrub_push (position);
 252   return input_scrub_new_file (filename);
 253 }
 254
 255 /* Start getting input from an sb structure.  This is used when
 256    expanding a macro.  */
 257
 258 void
 259 input_scrub_include_sb (sb *from, char *position, int is_expansion)
 260 {
 261   if (macro_nest > max_macro_nest)
 262     as_fatal (_("macros nested too deeply"));
 263   ++macro_nest;
 264
 265 #ifdef md_macro_start
 266   if (is_expansion)
 267     {
 268       md_macro_start ();
 269     }
 270 #endif
 271
 272   next_saved_file = input_scrub_push (position);
 273
 274   sb_new (&from_sb);
 275   from_sb_is_expansion = is_expansion;
 276   if (from->len >= 1 && from->ptr[0] != '\n')
 277     {
 278       /* Add the sentinel required by read.c.  */
 279       sb_add_char (&from_sb, '\n');
 280     }
 281   sb_scrub_and_add_sb (&from_sb, from);
 282   sb_index = 1;
 283
 284   /* These variables are reset by input_scrub_push.  Restore them
 285      since we are, after all, still at the same point in the file.  */
 286   logical_input_line = next_saved_file->logical_input_line;
 287   logical_input_file = next_saved_file->logical_input_file;
 288 }
 289
 290 void
 291 input_scrub_close (void)
 292 {
 293   input_file_close ();
 294 }
 295
 296 char *
 297 input_scrub_next_buffer (char **bufp)
 298 {
 299   register char *limit;         /*->just after last char of buffer.  */
 300
 301   if (sb_index >= 0)
 302     {
 303       if (sb_index >= from_sb.len)
 304         {
 305           sb_kill (&from_sb);
 306           if (from_sb_is_expansion
 307               )
 308             {
 309               cond_finish_check (macro_nest);
 310 #ifdef md_macro_end
 311               /* Allow the target to clean up per-macro expansion
 312                  data.  */
 313               md_macro_end ();
 314 #endif
 315             }
 316           --macro_nest;
 317           partial_where = NULL;
 318           if (next_saved_file != NULL)
 319             *bufp = input_scrub_pop (next_saved_file);
 320           return partial_where;
 321         }
 322
 323       partial_where = from_sb.ptr + from_sb.len;
 324       partial_size = 0;
 325       *bufp = from_sb.ptr + sb_index;
 326       sb_index = from_sb.len;
 327       return partial_where;
 328     }
 329
 330   *bufp = buffer_start + BEFORE_SIZE;
 331
 332   if (partial_size)
 333     {
 334       memcpy (buffer_start + BEFORE_SIZE, partial_where,
 335               (unsigned int) partial_size);
 336       memcpy (buffer_start + BEFORE_SIZE, save_source, AFTER_SIZE);
 337     }
 338   limit = input_file_give_next_buffer (buffer_start
 339                                        + BEFORE_SIZE
 340                                        + partial_size);
 341   if (limit)
 342     {
 343       register char *p;         /* Find last newline.  */
 344
 345       for (p = limit - 1; *p != '\n'; --p)
 346         ;
 347       ++p;
 348
 349       while (p <= buffer_start + BEFORE_SIZE)
 350         {
 351           int limoff;
 352
 353           limoff = limit - buffer_start;
 354           buffer_length += input_file_buffer_size ();
 355           buffer_start = xrealloc (buffer_start,
 356                                    (BEFORE_SIZE
 357                                     + 2 * buffer_length
 358                                     + AFTER_SIZE));
 359           *bufp = buffer_start + BEFORE_SIZE;
 360           limit = input_file_give_next_buffer (buffer_start + limoff);
 361
 362           if (limit == NULL)
 363             {
 364               as_warn (_("partial line at end of file ignored"));
 365               partial_where = NULL;
 366               if (next_saved_file)
 367                 *bufp = input_scrub_pop (next_saved_file);
 368               return NULL;
 369             }
 370
 371           for (p = limit - 1; *p != '\n'; --p)
 372             ;
 373           ++p;
 374         }
 375
 376       partial_where = p;
 377       partial_size = limit - p;
 378       memcpy (save_source, partial_where, (int) AFTER_SIZE);
 379       memcpy (partial_where, AFTER_STRING, (int) AFTER_SIZE);
 380     }
 381   else
 382     {
 383       partial_where = 0;
 384       if (partial_size > 0)
 385         {
 386           as_warn (_("partial line at end of file ignored"));
 387         }
 388
 389       /* Tell the listing we've finished the file.  */
 390       LISTING_EOF ();
 391
 392       /* If we should pop to another file at EOF, do it.  */
 393       if (next_saved_file)
 394         {
 395           *bufp = input_scrub_pop (next_saved_file);    /* Pop state */
 396           /* partial_where is now correct to return, since we popped it.  */
 397         }
 398     }
 399   return (partial_where);
 400 }
 401 \f
 402 /* The remaining part of this file deals with line numbers, error
 403    messages and so on.  Return TRUE if we opened any file.  */
 404
 405 int
 406 seen_at_least_1_file (void)
 407 {
 408   return (physical_input_file != NULL);
 409 }
 410
 411 void
 412 bump_line_counters (void)
 413 {
 414   if (sb_index < 0)
 415     {
 416       ++physical_input_line;
 417       if (logical_input_line >= 0)
 418         ++logical_input_line;
 419     }
 420 }
 421 \f
 422 /* Tells us what the new logical line number and file are.
 423    If the line_number is -1, we don't change the current logical line
 424    number.  If it is -2, we decrement the logical line number (this is
 425    to support the .appfile pseudo-op inserted into the stream by
 426    do_scrub_chars).
 427    If the fname is NULL, we don't change the current logical file name.
 428    Returns nonzero if the filename actually changes.  */
 429
 430 int
 431 new_logical_line (char *fname, /* DON'T destroy it!  We point to it!  */
 432                   int line_number)
 433 {
 434   if (line_number >= 0)
 435     logical_input_line = line_number;
 436   else if (line_number == -2 && logical_input_line > 0)
 437     --logical_input_line;
 438
 439   if (fname
 440       && (logical_input_file == NULL
 441           || strcmp (logical_input_file, fname)))
 442     {
 443       logical_input_file = fname;
 444       return 1;
 445     }
 446   else
 447     return 0;
 448 }
 449 \f
 450 /* Return the current file name and line number.
 451    namep should be char * const *, but there are compilers which screw
 452    up declarations like that, and it's easier to avoid it.  */
 453
 454 void
 455 as_where (char **namep, unsigned int *linep)
 456 {
 457   if (logical_input_file != NULL
 458       && (linep == NULL || logical_input_line >= 0))
 459     {
 460       *namep = logical_input_file;
 461       if (linep != NULL)
 462         *linep = logical_input_line;
 463     }
 464   else if (physical_input_file != NULL)
 465     {
 466       *namep = physical_input_file;
 467       if (linep != NULL)
 468         *linep = physical_input_line;
 469     }
 470   else
 471     {
 472       *namep = 0;
 473       if (linep != NULL)
 474         *linep = 0;
 475     }
 476 }