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
   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, 59 Temple Place - Suite 330, Boston, MA
  21    02111-1307, USA.  */
  22
  23 #include <errno.h>              /* Need this to make errno declaration right */
  24 #include "as.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 static char *buffer_start;      /*->1st char of full buffer area.  */
  61 static char *partial_where;     /*->after last full line in buffer.  */
  62 static int partial_size;        /* >=0. Number of chars in partial line in buffer.  */
  63
  64 /* Because we need AFTER_STRING just after last full line, it clobbers
  65    1st part of partial line. So we preserve 1st part of partial line
  66    here.  */
  67 static char save_source[AFTER_SIZE];
  68
  69 /* What is the largest size buffer that input_file_give_next_buffer()
  70    could return to us?  */
  71 static unsigned int buffer_length;
  72
  73 /* The index into an sb structure we are reading from.  -1 if none.  */
  74 static int sb_index = -1;
  75
  76 /* If we are reading from an sb structure, this is it.  */
  77 static sb from_sb;
  78
  79 /* Should we do a conditional check on from_sb? */
  80 static int from_sb_is_expansion = 1;
  81
  82 /* The number of nested sb structures we have included.  */
  83 int macro_nest;
  84
  85 /* We can have more than one source file open at once, though the info for all
  86    but the latest one are saved off in a struct input_save.  These files remain
  87    open, so we are limited by the number of open files allowed by the
  88    underlying OS. We may also sequentially read more than one source file in an
  89    assembly.  */
  90
  91 /* We must track the physical file and line number for error messages. We also
  92    track a "logical" file and line number corresponding to (C?)  compiler
  93    source line numbers.  Whenever we open a file we must fill in
  94    physical_input_file. So if it is NULL we have not opened any files yet.  */
  95
  96 static char *physical_input_file;
  97 static char *logical_input_file;
  98
  99 typedef unsigned int line_numberT;      /* 1-origin line number in a source file.  */
 100 /* A line ends in '\n' or eof.  */
 101
 102 static line_numberT physical_input_line;
 103 static int logical_input_line;
 104
 105 /* Struct used to save the state of the input handler during include files */
 106 struct input_save {
 107   char *              buffer_start;
 108   char *              partial_where;
 109   int                 partial_size;
 110   char                save_source[AFTER_SIZE];
 111   unsigned int        buffer_length;
 112   char *              physical_input_file;
 113   char *              logical_input_file;
 114   line_numberT        physical_input_line;
 115   int                 logical_input_line;
 116   int                 sb_index;
 117   sb                  from_sb;
 118   int                 from_sb_is_expansion; /* Should we do a conditional check?  */
 119   struct input_save * next_saved_file;  /* Chain of input_saves.  */
 120   char *              input_file_save;  /* Saved state of input routines.  */
 121   char *              saved_position;   /* Caller's saved position in buf.  */
 122 };
 123
 124 static struct input_save *input_scrub_push (char *saved_position);
 125 static char *input_scrub_pop (struct input_save *arg);
 126
 127 /* Saved information about the file that .include'd this one.  When we hit EOF,
 128    we automatically pop to that file.  */
 129
 130 static struct input_save *next_saved_file;
 131
 132 /* Push the state of input reading and scrubbing so that we can #include.
 133    The return value is a 'void *' (fudged for old compilers) to a save
 134    area, which can be restored by passing it to input_scrub_pop().  */
 135
 136 static struct input_save *
 137 input_scrub_push (char *saved_position)
 138 {
 139   register struct input_save *saved;
 140
 141   saved = (struct input_save *) xmalloc (sizeof *saved);
 142
 143   saved->saved_position = saved_position;
 144   saved->buffer_start = buffer_start;
 145   saved->partial_where = partial_where;
 146   saved->partial_size = partial_size;
 147   saved->buffer_length = buffer_length;
 148   saved->physical_input_file = physical_input_file;
 149   saved->logical_input_file = logical_input_file;
 150   saved->physical_input_line = physical_input_line;
 151   saved->logical_input_line = logical_input_line;
 152   saved->sb_index = sb_index;
 153   saved->from_sb = from_sb;
 154   saved->from_sb_is_expansion = from_sb_is_expansion;
 155   memcpy (saved->save_source, save_source, sizeof (save_source));
 156   saved->next_saved_file = next_saved_file;
 157   saved->input_file_save = input_file_push ();
 158
 159   input_file_begin ();          /* Reinitialize! */
 160   logical_input_line = -1;
 161   logical_input_file = (char *) NULL;
 162   buffer_length = input_file_buffer_size ();
 163   sb_index = -1;
 164
 165   buffer_start = xmalloc ((BEFORE_SIZE + buffer_length + buffer_length + AFTER_SIZE));
 166   memcpy (buffer_start, BEFORE_STRING, (int) BEFORE_SIZE);
 167
 168   return saved;
 169 }
 170
 171 static char *
 172 input_scrub_pop (struct input_save *saved)
 173 {
 174   char *saved_position;
 175
 176   input_scrub_end ();           /* Finish off old buffer */
 177
 178   input_file_pop (saved->input_file_save);
 179   saved_position = saved->saved_position;
 180   buffer_start = saved->buffer_start;
 181   buffer_length = saved->buffer_length;
 182   physical_input_file = saved->physical_input_file;
 183   logical_input_file = saved->logical_input_file;
 184   physical_input_line = saved->physical_input_line;
 185   logical_input_line = saved->logical_input_line;
 186   sb_index = saved->sb_index;
 187   from_sb = saved->from_sb;
 188   from_sb_is_expansion = saved->from_sb_is_expansion;
 189   partial_where = saved->partial_where;
 190   partial_size = saved->partial_size;
 191   next_saved_file = saved->next_saved_file;
 192   memcpy (save_source, saved->save_source, sizeof (save_source));
 193
 194   free (saved);
 195   return saved_position;
 196 }
 197 \f
 198 void
 199 input_scrub_begin (void)
 200 {
 201   know (strlen (BEFORE_STRING) == BEFORE_SIZE);
 202   know (strlen (AFTER_STRING) == AFTER_SIZE
 203         || (AFTER_STRING[0] == '\0' && AFTER_SIZE == 1));
 204
 205   input_file_begin ();
 206
 207   buffer_length = input_file_buffer_size ();
 208
 209   buffer_start = xmalloc ((BEFORE_SIZE + buffer_length + buffer_length + AFTER_SIZE));
 210   memcpy (buffer_start, BEFORE_STRING, (int) BEFORE_SIZE);
 211
 212   /* Line number things.  */
 213   logical_input_line = -1;
 214   logical_input_file = (char *) NULL;
 215   physical_input_file = NULL;   /* No file read yet.  */
 216   next_saved_file = NULL;       /* At EOF, don't pop to any other file */
 217   do_scrub_begin (flag_m68k_mri);
 218 }
 219
 220 void
 221 input_scrub_end (void)
 222 {
 223   if (buffer_start)
 224     {
 225       free (buffer_start);
 226       buffer_start = 0;
 227       input_file_end ();
 228     }
 229 }
 230
 231 /* Start reading input from a new file.
 232    Return start of caller's part of buffer.  */
 233
 234 char *
 235 input_scrub_new_file (char *filename)
 236 {
 237   input_file_open (filename, !flag_no_comments);
 238   physical_input_file = filename[0] ? filename : _("{standard input}");
 239   physical_input_line = 0;
 240
 241   partial_size = 0;
 242   return (buffer_start + BEFORE_SIZE);
 243 }
 244
 245 /* Include a file from the current file.  Save our state, cause it to
 246    be restored on EOF, and begin handling a new file.  Same result as
 247    input_scrub_new_file.  */
 248
 249 char *
 250 input_scrub_include_file (char *filename, char *position)
 251 {
 252   next_saved_file = input_scrub_push (position);
 253   return input_scrub_new_file (filename);
 254 }
 255
 256 /* Start getting input from an sb structure.  This is used when
 257    expanding a macro.  */
 258
 259 void
 260 input_scrub_include_sb (sb *from, char *position, int is_expansion)
 261 {
 262   if (macro_nest > max_macro_nest)
 263     as_fatal (_("macros nested too deeply"));
 264   ++macro_nest;
 265
 266 #ifdef md_macro_start
 267   if (is_expansion)
 268     {
 269       md_macro_start ();
 270     }
 271 #endif
 272
 273   next_saved_file = input_scrub_push (position);
 274
 275   sb_new (&from_sb);
 276   from_sb_is_expansion = is_expansion;
 277   if (from->len >= 1 && from->ptr[0] != '\n')
 278     {
 279       /* Add the sentinel required by read.c.  */
 280       sb_add_char (&from_sb, '\n');
 281     }
 282   sb_add_sb (&from_sb, from);
 283   sb_index = 1;
 284
 285   /* These variables are reset by input_scrub_push.  Restore them
 286      since we are, after all, still at the same point in the file.  */
 287   logical_input_line = next_saved_file->logical_input_line;
 288   logical_input_file = next_saved_file->logical_input_file;
 289 }
 290
 291 void
 292 input_scrub_close (void)
 293 {
 294   input_file_close ();
 295 }
 296
 297 char *
 298 input_scrub_next_buffer (char **bufp)
 299 {
 300   register char *limit;         /*->just after last char of buffer.  */
 301
 302   if (sb_index >= 0)
 303     {
 304       if (sb_index >= from_sb.len)
 305         {
 306           sb_kill (&from_sb);
 307           if (from_sb_is_expansion
 308               )
 309             {
 310               cond_finish_check (macro_nest);
 311 #ifdef md_macro_end
 312               /* Allow the target to clean up per-macro expansion
 313                  data.  */
 314               md_macro_end ();
 315 #endif
 316             }
 317           --macro_nest;
 318           partial_where = NULL;
 319           if (next_saved_file != NULL)
 320             *bufp = input_scrub_pop (next_saved_file);
 321           return partial_where;
 322         }
 323
 324       partial_where = from_sb.ptr + from_sb.len;
 325       partial_size = 0;
 326       *bufp = from_sb.ptr + sb_index;
 327       sb_index = from_sb.len;
 328       return partial_where;
 329     }
 330
 331   *bufp = buffer_start + BEFORE_SIZE;
 332
 333   if (partial_size)
 334     {
 335       memcpy (buffer_start + BEFORE_SIZE, partial_where,
 336               (unsigned int) partial_size);
 337       memcpy (buffer_start + BEFORE_SIZE, save_source, AFTER_SIZE);
 338     }
 339   limit = input_file_give_next_buffer (buffer_start
 340                                        + BEFORE_SIZE
 341                                        + partial_size);
 342   if (limit)
 343     {
 344       register char *p;         /* Find last newline.  */
 345
 346       for (p = limit - 1; *p != '\n'; --p)
 347         ;
 348       ++p;
 349
 350       while (p <= buffer_start + BEFORE_SIZE)
 351         {
 352           int limoff;
 353
 354           limoff = limit - buffer_start;
 355           buffer_length += input_file_buffer_size ();
 356           buffer_start = xrealloc (buffer_start,
 357                                    (BEFORE_SIZE
 358                                     + 2 * buffer_length
 359                                     + AFTER_SIZE));
 360           *bufp = buffer_start + BEFORE_SIZE;
 361           limit = input_file_give_next_buffer (buffer_start + limoff);
 362
 363           if (limit == NULL)
 364             {
 365               as_warn (_("partial line at end of file ignored"));
 366               partial_where = NULL;
 367               if (next_saved_file)
 368                 *bufp = input_scrub_pop (next_saved_file);
 369               return NULL;
 370             }
 371
 372           for (p = limit - 1; *p != '\n'; --p)
 373             ;
 374           ++p;
 375         }
 376
 377       partial_where = p;
 378       partial_size = limit - p;
 379       memcpy (save_source, partial_where, (int) AFTER_SIZE);
 380       memcpy (partial_where, AFTER_STRING, (int) AFTER_SIZE);
 381     }
 382   else
 383     {
 384       partial_where = 0;
 385       if (partial_size > 0)
 386         {
 387           as_warn (_("partial line at end of file ignored"));
 388         }
 389
 390       /* Tell the listing we've finished the file.  */
 391       LISTING_EOF ();
 392
 393       /* If we should pop to another file at EOF, do it.  */
 394       if (next_saved_file)
 395         {
 396           *bufp = input_scrub_pop (next_saved_file);    /* Pop state */
 397           /* partial_where is now correct to return, since we popped it.  */
 398         }
 399     }
 400   return (partial_where);
 401 }
 402 \f
 403 /* The remaining part of this file deals with line numbers, error
 404    messages and so on.  Return TRUE if we opened any file.  */
 405
 406 int
 407 seen_at_least_1_file (void)
 408 {
 409   return (physical_input_file != NULL);
 410 }
 411
 412 void
 413 bump_line_counters (void)
 414 {
 415   if (sb_index < 0)
 416     {
 417       ++physical_input_line;
 418       if (logical_input_line >= 0)
 419         ++logical_input_line;
 420     }
 421 }
 422 \f
 423 /* Tells us what the new logical line number and file are.
 424    If the line_number is -1, we don't change the current logical line
 425    number.  If it is -2, we decrement the logical line number (this is
 426    to support the .appfile pseudo-op inserted into the stream by
 427    do_scrub_chars).
 428    If the fname is NULL, we don't change the current logical file name.
 429    Returns nonzero if the filename actually changes.  */
 430
 431 int
 432 new_logical_line (char *fname, /* DON'T destroy it!  We point to it!  */
 433                   int line_number)
 434 {
 435   if (line_number >= 0)
 436     logical_input_line = line_number;
 437   else if (line_number == -2 && logical_input_line > 0)
 438     --logical_input_line;
 439
 440   if (fname
 441       && (logical_input_file == NULL
 442           || strcmp (logical_input_file, fname)))
 443     {
 444       logical_input_file = fname;
 445       return 1;
 446     }
 447   else
 448     return 0;
 449 }
 450 \f
 451 /* Return the current file name and line number.
 452    namep should be char * const *, but there are compilers which screw
 453    up declarations like that, and it's easier to avoid it.  */
 454
 455 void
 456 as_where (char **namep, unsigned int *linep)
 457 {
 458   if (logical_input_file != NULL
 459       && (linep == NULL || logical_input_line >= 0))
 460     {
 461       *namep = logical_input_file;
 462       if (linep != NULL)
 463         *linep = logical_input_line;
 464     }
 465   else if (physical_input_file != NULL)
 466     {
 467       *namep = physical_input_file;
 468       if (linep != NULL)
 469         *linep = physical_input_line;
 470     }
 471   else
 472     {
 473       *namep = 0;
 474       if (linep != NULL)
 475         *linep = 0;
 476     }
 477 }