gcc/read-md.c

   1 /* MD reader for GCC.
   2    Copyright (C) 1987, 1988, 1991, 1994, 1997, 1998, 1999, 2000, 2001, 2002,
   3    2003, 2004, 2005, 2006, 2007, 2008, 2010, 2011, 2012
   4    Free Software Foundation, Inc.
   5
   6 This file is part of GCC.
   7
   8 GCC is free software; you can redistribute it and/or modify it under
   9 the terms of the GNU General Public License as published by the Free
  10 Software Foundation; either version 3, or (at your option) any later
  11 version.
  12
  13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  15 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  16 for more details.
  17
  18 You should have received a copy of the GNU General Public License
  19 along with GCC; see the file COPYING3.  If not see
  20 <http://www.gnu.org/licenses/>.  */
  21
  22 #include "bconfig.h"
  23 #include "system.h"
  24 #include "coretypes.h"
  25 #include "hashtab.h"
  26 #include "errors.h"
  27 #include "read-md.h"
  28
  29 /* Associates PTR (which can be a string, etc.) with the file location
  30    specified by FILENAME and LINENO.  */
  31 struct ptr_loc {
  32   const void *ptr;
  33   const char *filename;
  34   int lineno;
  35 };
  36
  37 /* A singly-linked list of filenames.  */
  38 struct file_name_list {
  39   struct file_name_list *next;
  40   const char *fname;
  41 };
  42
  43 /* Obstack used for allocating MD strings.  */
  44 struct obstack string_obstack;
  45
  46 /* A table of ptr_locs, hashed on the PTR field.  */
  47 static htab_t ptr_locs;
  48
  49 /* An obstack for the above.  Plain xmalloc is a bit heavyweight for a
  50    small structure like ptr_loc.  */
  51 static struct obstack ptr_loc_obstack;
  52
  53 /* A hash table of triples (A, B, C), where each of A, B and C is a condition
  54    and A is equivalent to "B && C".  This is used to keep track of the source
  55    of conditions that are made up of separate MD strings (such as the split
  56    condition of a define_insn_and_split).  */
  57 static htab_t joined_conditions;
  58
  59 /* An obstack for allocating joined_conditions entries.  */
  60 static struct obstack joined_conditions_obstack;
  61
  62 /* The file we are reading.  */
  63 FILE *read_md_file;
  64
  65 /* The filename of READ_MD_FILE.  */
  66 const char *read_md_filename;
  67
  68 /* The current line number in READ_MD_FILE.  */
  69 int read_md_lineno;
  70
  71 /* The name of the toplevel file that indirectly included READ_MD_FILE.  */
  72 const char *in_fname;
  73
  74 /* The directory part of IN_FNAME.  NULL if IN_FNAME is a bare filename.  */
  75 static char *base_dir;
  76
  77 /* The first directory to search.  */
  78 static struct file_name_list *first_dir_md_include;
  79
  80 /* A pointer to the null terminator of the md include chain.  */
  81 static struct file_name_list **last_dir_md_include_ptr = &first_dir_md_include;
  82
  83 /* This callback will be invoked whenever an md include directive is
  84    processed.  To be used for creation of the dependency file.  */
  85 void (*include_callback) (const char *);
  86
  87 /* The current maximum length of directory names in the search path
  88    for include files.  (Altered as we get more of them.)  */
  89 static size_t max_include_len;
  90
  91 /* A table of md_constant structures, hashed by name.  Null if no
  92    constant expansion should occur.  */
  93 static htab_t md_constants;
  94
  95 /* A table of enum_type structures, hashed by name.  */
  96 static htab_t enum_types;
  97
  98 static void handle_file (directive_handler_t);
  99
 100 /* Given an object that starts with a char * name field, return a hash
 101    code for its name.  */
 102
 103 hashval_t
 104 leading_string_hash (const void *def)
 105 {
 106   return htab_hash_string (*(const char *const *) def);
 107 }
 108
 109 /* Given two objects that start with char * name fields, return true if
 110    they have the same name.  */
 111
 112 int
 113 leading_string_eq_p (const void *def1, const void *def2)
 114 {
 115   return strcmp (*(const char *const *) def1,
 116                  *(const char *const *) def2) == 0;
 117 }
 118
 119 /* Return a hash value for the pointer pointed to by DEF.  */
 120
 121 static hashval_t
 122 leading_ptr_hash (const void *def)
 123 {
 124   return htab_hash_pointer (*(const void *const *) def);
 125 }
 126
 127 /* Return true if DEF1 and DEF2 are pointers to the same pointer.  */
 128
 129 static int
 130 leading_ptr_eq_p (const void *def1, const void *def2)
 131 {
 132   return *(const void *const *) def1 == *(const void *const *) def2;
 133 }
 134
 135 /* Associate PTR with the file position given by FILENAME and LINENO.  */
 136
 137 static void
 138 set_md_ptr_loc (const void *ptr, const char *filename, int lineno)
 139 {
 140   struct ptr_loc *loc;
 141
 142   loc = (struct ptr_loc *) obstack_alloc (&ptr_loc_obstack,
 143                                           sizeof (struct ptr_loc));
 144   loc->ptr = ptr;
 145   loc->filename = filename;
 146   loc->lineno = lineno;
 147   *htab_find_slot (ptr_locs, loc, INSERT) = loc;
 148 }
 149
 150 /* Return the position associated with pointer PTR.  Return null if no
 151    position was set.  */
 152
 153 static const struct ptr_loc *
 154 get_md_ptr_loc (const void *ptr)
 155 {
 156   return (const struct ptr_loc *) htab_find (ptr_locs, &ptr);
 157 }
 158
 159 /* Associate NEW_PTR with the same file position as OLD_PTR.  */
 160
 161 void
 162 copy_md_ptr_loc (const void *new_ptr, const void *old_ptr)
 163 {
 164   const struct ptr_loc *loc = get_md_ptr_loc (old_ptr);
 165   if (loc != 0)
 166     set_md_ptr_loc (new_ptr, loc->filename, loc->lineno);
 167 }
 168
 169 /* If PTR is associated with a known file position, print a #line
 170    directive for it to OUTF.  */
 171
 172 void
 173 fprint_md_ptr_loc (FILE *outf, const void *ptr)
 174 {
 175   const struct ptr_loc *loc = get_md_ptr_loc (ptr);
 176   if (loc != 0)
 177     fprintf (outf, "#line %d \"%s\"\n", loc->lineno, loc->filename);
 178 }
 179
 180 /* Special fprint_md_ptr_loc for writing to STDOUT.  */
 181 void
 182 print_md_ptr_loc (const void *ptr)
 183 {
 184   fprint_md_ptr_loc (stdout, ptr);
 185 }
 186
 187 /* Return a condition that satisfies both COND1 and COND2.  Either string
 188    may be null or empty.  */
 189
 190 const char *
 191 join_c_conditions (const char *cond1, const char *cond2)
 192 {
 193   char *result;
 194   const void **entry;
 195
 196   if (cond1 == 0 || cond1[0] == 0)
 197     return cond2;
 198
 199   if (cond2 == 0 || cond2[0] == 0)
 200     return cond1;
 201
 202   if (strcmp (cond1, cond2) == 0)
 203     return cond1;
 204
 205   result = concat ("(", cond1, ") && (", cond2, ")", NULL);
 206   obstack_ptr_grow (&joined_conditions_obstack, result);
 207   obstack_ptr_grow (&joined_conditions_obstack, cond1);
 208   obstack_ptr_grow (&joined_conditions_obstack, cond2);
 209   entry = XOBFINISH (&joined_conditions_obstack, const void **);
 210   *htab_find_slot (joined_conditions, entry, INSERT) = entry;
 211   return result;
 212 }
 213
 214 /* Print condition COND to OUTF, wrapped in brackets.  If COND was created
 215    by join_c_conditions, recursively invoke this function for the original
 216    conditions and join the result with "&&".  Otherwise print a #line
 217    directive for COND if its original file position is known.  */
 218
 219 void
 220 fprint_c_condition (FILE *outf, const char *cond)
 221 {
 222   const char **halves = (const char **) htab_find (joined_conditions, &cond);
 223   if (halves != 0)
 224     {
 225       fprintf (outf, "(");
 226       fprint_c_condition (outf, halves[1]);
 227       fprintf (outf, " && ");
 228       fprint_c_condition (outf, halves[2]);
 229       fprintf (outf, ")");
 230     }
 231   else
 232     {
 233       fputc ('\n', outf);
 234       fprint_md_ptr_loc (outf, cond);
 235       fprintf (outf, "(%s)", cond);
 236     }
 237 }
 238
 239 /* Special fprint_c_condition for writing to STDOUT.  */
 240
 241 void
 242 print_c_condition (const char *cond)
 243 {
 244   fprint_c_condition (stdout, cond);
 245 }
 246
 247 /* A vfprintf-like function for reporting an error against line LINENO
 248    of the current MD file.  */
 249
 250 static void ATTRIBUTE_PRINTF(2,0)
 251 message_with_line_1 (int lineno, const char *msg, va_list ap)
 252 {
 253   fprintf (stderr, "%s:%d: ", read_md_filename, lineno);
 254   vfprintf (stderr, msg, ap);
 255   fputc ('\n', stderr);
 256 }
 257
 258 /* A printf-like function for reporting an error against line LINENO
 259    in the current MD file.  */
 260
 261 void
 262 message_with_line (int lineno, const char *msg, ...)
 263 {
 264   va_list ap;
 265
 266   va_start (ap, msg);
 267   message_with_line_1 (lineno, msg, ap);
 268   va_end (ap);
 269 }
 270
 271 /* Like message_with_line, but treat the condition as an error.  */
 272
 273 void
 274 error_with_line (int lineno, const char *msg, ...)
 275 {
 276   va_list ap;
 277
 278   va_start (ap, msg);
 279   message_with_line_1 (lineno, msg, ap);
 280   va_end (ap);
 281   have_error = 1;
 282 }
 283
 284 /* A printf-like function for reporting an error against the current
 285    position in the MD file.  */
 286
 287 void
 288 fatal_with_file_and_line (const char *msg, ...)
 289 {
 290   char context[64];
 291   size_t i;
 292   int c;
 293   va_list ap;
 294
 295   va_start (ap, msg);
 296
 297   fprintf (stderr, "%s:%d: ", read_md_filename, read_md_lineno);
 298   vfprintf (stderr, msg, ap);
 299   putc ('\n', stderr);
 300
 301   /* Gather some following context.  */
 302   for (i = 0; i < sizeof (context)-1; ++i)
 303     {
 304       c = read_char ();
 305       if (c == EOF)
 306         break;
 307       if (c == '\r' || c == '\n')
 308         {
 309           unread_char (c);
 310           break;
 311         }
 312       context[i] = c;
 313     }
 314   context[i] = '\0';
 315
 316   fprintf (stderr, "%s:%d: following context is `%s'\n",
 317            read_md_filename, read_md_lineno, context);
 318
 319   va_end (ap);
 320   exit (1);
 321 }
 322
 323 /* Report that we found character ACTUAL when we expected to find
 324    character EXPECTED.  */
 325
 326 void
 327 fatal_expected_char (int expected, int actual)
 328 {
 329   if (actual == EOF)
 330     fatal_with_file_and_line ("expected character `%c', found EOF",
 331                               expected);
 332   else
 333     fatal_with_file_and_line ("expected character `%c', found `%c'",
 334                               expected, actual);
 335 }
 336
 337 /* Read chars from the MD file until a non-whitespace char and return that.
 338    Comments, both Lisp style and C style, are treated as whitespace.  */
 339
 340 int
 341 read_skip_spaces (void)
 342 {
 343   int c;
 344
 345   while (1)
 346     {
 347       c = read_char ();
 348       switch (c)
 349         {
 350         case ' ': case '\t': case '\f': case '\r': case '\n':
 351           break;
 352
 353         case ';':
 354           do
 355             c = read_char ();
 356           while (c != '\n' && c != EOF);
 357           break;
 358
 359         case '/':
 360           {
 361             int prevc;
 362             c = read_char ();
 363             if (c != '*')
 364               {
 365                 unread_char (c);
 366                 fatal_with_file_and_line ("stray '/' in file");
 367               }
 368
 369             prevc = 0;
 370             while ((c = read_char ()) && c != EOF)
 371               {
 372                 if (prevc == '*' && c == '/')
 373                   break;
 374                 prevc = c;
 375               }
 376           }
 377           break;
 378
 379         default:
 380           return c;
 381         }
 382     }
 383 }
 384
 385 /* Read an rtx code name into NAME.  It is terminated by any of the
 386    punctuation chars of rtx printed syntax.  */
 387
 388 void
 389 read_name (struct md_name *name)
 390 {
 391   int c;
 392   size_t i;
 393
 394   c = read_skip_spaces ();
 395
 396   i = 0;
 397   while (1)
 398     {
 399       if (c == ' ' || c == '\n' || c == '\t' || c == '\f' || c == '\r'
 400           || c == EOF)
 401         break;
 402       if (c == ':' || c == ')' || c == ']' || c == '"' || c == '/'
 403           || c == '(' || c == '[')
 404         {
 405           unread_char (c);
 406           break;
 407         }
 408
 409       if (i == sizeof (name->buffer) - 1)
 410         fatal_with_file_and_line ("name too long");
 411       name->buffer[i++] = c;
 412
 413       c = read_char ();
 414     }
 415
 416   if (i == 0)
 417     fatal_with_file_and_line ("missing name or number");
 418
 419   name->buffer[i] = 0;
 420   name->string = name->buffer;
 421
 422   if (md_constants)
 423     {
 424       /* Do constant expansion.  */
 425       struct md_constant *def;
 426
 427       do
 428         {
 429           struct md_constant tmp_def;
 430
 431           tmp_def.name = name->string;
 432           def = (struct md_constant *) htab_find (md_constants, &tmp_def);
 433           if (def)
 434             name->string = def->value;
 435         }
 436       while (def);
 437     }
 438 }
 439
 440 /* Subroutine of the string readers.  Handles backslash escapes.
 441    Caller has read the backslash, but not placed it into the obstack.  */
 442
 443 static void
 444 read_escape (void)
 445 {
 446   int c = read_char ();
 447
 448   switch (c)
 449     {
 450       /* Backslash-newline is replaced by nothing, as in C.  */
 451     case '\n':
 452       return;
 453
 454       /* \" \' \\ are replaced by the second character.  */
 455     case '\\':
 456     case '"':
 457     case '\'':
 458       break;
 459
 460       /* Standard C string escapes:
 461          \a \b \f \n \r \t \v
 462          \[0-7] \x
 463          all are passed through to the output string unmolested.
 464          In normal use these wind up in a string constant processed
 465          by the C compiler, which will translate them appropriately.
 466          We do not bother checking that \[0-7] are followed by up to
 467          two octal digits, or that \x is followed by N hex digits.
 468          \? \u \U are left out because they are not in traditional C.  */
 469     case 'a': case 'b': case 'f': case 'n': case 'r': case 't': case 'v':
 470     case '0': case '1': case '2': case '3': case '4': case '5': case '6':
 471     case '7': case 'x':
 472       obstack_1grow (&string_obstack, '\\');
 473       break;
 474
 475       /* \; makes stuff for a C string constant containing
 476          newline and tab.  */
 477     case ';':
 478       obstack_grow (&string_obstack, "\\n\\t", 4);
 479       return;
 480
 481       /* pass anything else through, but issue a warning.  */
 482     default:
 483       fprintf (stderr, "%s:%d: warning: unrecognized escape \\%c\n",
 484                read_md_filename, read_md_lineno, c);
 485       obstack_1grow (&string_obstack, '\\');
 486       break;
 487     }
 488
 489   obstack_1grow (&string_obstack, c);
 490 }
 491
 492 /* Read a double-quoted string onto the obstack.  Caller has scanned
 493    the leading quote.  */
 494
 495 char *
 496 read_quoted_string (void)
 497 {
 498   int c;
 499
 500   while (1)
 501     {
 502       c = read_char (); /* Read the string  */
 503       if (c == '\\')
 504         {
 505           read_escape ();
 506           continue;
 507         }
 508       else if (c == '"' || c == EOF)
 509         break;
 510
 511       obstack_1grow (&string_obstack, c);
 512     }
 513
 514   obstack_1grow (&string_obstack, 0);
 515   return XOBFINISH (&string_obstack, char *);
 516 }
 517
 518 /* Read a braced string (a la Tcl) onto the string obstack.  Caller
 519    has scanned the leading brace.  Note that unlike quoted strings,
 520    the outermost braces _are_ included in the string constant.  */
 521
 522 static char *
 523 read_braced_string (void)
 524 {
 525   int c;
 526   int brace_depth = 1;  /* caller-processed */
 527   unsigned long starting_read_md_lineno = read_md_lineno;
 528
 529   obstack_1grow (&string_obstack, '{');
 530   while (brace_depth)
 531     {
 532       c = read_char (); /* Read the string  */
 533
 534       if (c == '{')
 535         brace_depth++;
 536       else if (c == '}')
 537         brace_depth--;
 538       else if (c == '\\')
 539         {
 540           read_escape ();
 541           continue;
 542         }
 543       else if (c == EOF)
 544         fatal_with_file_and_line
 545           ("missing closing } for opening brace on line %lu",
 546            starting_read_md_lineno);
 547
 548       obstack_1grow (&string_obstack, c);
 549     }
 550
 551   obstack_1grow (&string_obstack, 0);
 552   return XOBFINISH (&string_obstack, char *);
 553 }
 554
 555 /* Read some kind of string constant.  This is the high-level routine
 556    used by read_rtx.  It handles surrounding parentheses, leading star,
 557    and dispatch to the appropriate string constant reader.  */
 558
 559 char *
 560 read_string (int star_if_braced)
 561 {
 562   char *stringbuf;
 563   int saw_paren = 0;
 564   int c, old_lineno;
 565
 566   c = read_skip_spaces ();
 567   if (c == '(')
 568     {
 569       saw_paren = 1;
 570       c = read_skip_spaces ();
 571     }
 572
 573   old_lineno = read_md_lineno;
 574   if (c == '"')
 575     stringbuf = read_quoted_string ();
 576   else if (c == '{')
 577     {
 578       if (star_if_braced)
 579         obstack_1grow (&string_obstack, '*');
 580       stringbuf = read_braced_string ();
 581     }
 582   else
 583     fatal_with_file_and_line ("expected `\"' or `{', found `%c'", c);
 584
 585   if (saw_paren)
 586     {
 587       c = read_skip_spaces ();
 588       if (c != ')')
 589         fatal_expected_char (')', c);
 590     }
 591
 592   set_md_ptr_loc (stringbuf, read_md_filename, old_lineno);
 593   return stringbuf;
 594 }
 595
 596 /* Skip the rest of a construct that started at line LINENO and that
 597    is currently nested by DEPTH levels of parentheses.  */
 598
 599 void
 600 read_skip_construct (int depth, int lineno)
 601 {
 602   struct md_name name;
 603   int c;
 604
 605   do
 606     {
 607       c = read_skip_spaces ();
 608       if (c == EOF)
 609         {
 610           error_with_line (lineno, "unterminated construct");
 611           exit (1);
 612         }
 613       switch (c)
 614         {
 615         case '(':
 616           depth++;
 617           break;
 618
 619         case ')':
 620           depth--;
 621           break;
 622
 623         case ':':
 624         case '[':
 625         case ']':
 626         case '/':
 627           break;
 628
 629         case '\"':
 630         case '{':
 631           unread_char (c);
 632           read_string (false);
 633           break;
 634
 635         default:
 636           unread_char (c);
 637           read_name (&name);
 638           break;
 639         }
 640     }
 641   while (depth > 0);
 642   unread_char (c);
 643 }
 644
 645 /* Given a string, return the number of comma-separated elements in it.
 646    Return 0 for the null string.  */
 647
 648 int
 649 n_comma_elts (const char *s)
 650 {
 651   int n;
 652
 653   if (*s == '\0')
 654     return 0;
 655
 656   for (n = 1; *s; s++)
 657     if (*s == ',')
 658       n++;
 659
 660   return n;
 661 }
 662
 663 /* Given a pointer to a (char *), return a pointer to the beginning of the
 664    next comma-separated element in the string.  Advance the pointer given
 665    to the end of that element.  Return NULL if at end of string.  Caller
 666    is responsible for copying the string if necessary.  White space between
 667    a comma and an element is ignored.  */
 668
 669 const char *
 670 scan_comma_elt (const char **pstr)
 671 {
 672   const char *start;
 673   const char *p = *pstr;
 674
 675   if (*p == ',')
 676     p++;
 677   while (ISSPACE(*p))
 678     p++;
 679
 680   if (*p == '\0')
 681     return NULL;
 682
 683   start = p;
 684
 685   while (*p != ',' && *p != '\0')
 686     p++;
 687
 688   *pstr = p;
 689   return start;
 690 }
 691
 692 /* Convert STRING to uppercase.  */
 693
 694 void
 695 upcase_string (char *string)
 696 {
 697   int i;
 698
 699   for (i = 0; string[i]; i++)
 700     string[i] = TOUPPER (string[i]);
 701 }
 702
 703 /* Add a NAME = VALUE definition to md_constants-style hash table DEFS,
 704    where both NAME and VALUE are malloc()ed strings.  PARENT_ENUM is the
 705    enum to which NAME belongs, or null if NAME is a stand-alone constant.  */
 706
 707 static struct md_constant *
 708 add_constant (htab_t defs, char *name, char *value,
 709               struct enum_type *parent_enum)
 710 {
 711   struct md_constant *def, tmp_def;
 712   void **entry_ptr;
 713
 714   tmp_def.name = name;
 715   entry_ptr = htab_find_slot (defs, &tmp_def, INSERT);
 716   if (*entry_ptr)
 717     {
 718       def = (struct md_constant *) *entry_ptr;
 719       if (strcmp (def->value, value) != 0)
 720         fatal_with_file_and_line ("redefinition of `%s', was `%s', now `%s'",
 721                                   def->name, def->value, value);
 722       else if (parent_enum || def->parent_enum)
 723         fatal_with_file_and_line ("redefinition of `%s'", def->name);
 724       free (name);
 725       free (value);
 726     }
 727   else
 728     {
 729       def = XNEW (struct md_constant);
 730       def->name = name;
 731       def->value = value;
 732       def->parent_enum = parent_enum;
 733       *entry_ptr = def;
 734     }
 735   return def;
 736 }
 737
 738 /* Process a define_constants directive, starting with the optional space
 739    after the "define_constants".  */
 740
 741 static void
 742 handle_constants (void)
 743 {
 744   int c;
 745   htab_t defs;
 746
 747   c = read_skip_spaces ();
 748   if (c != '[')
 749     fatal_expected_char ('[', c);
 750
 751   /* Disable constant expansion during definition processing.  */
 752   defs = md_constants;
 753   md_constants = 0;
 754   while ( (c = read_skip_spaces ()) != ']')
 755     {
 756       struct md_name name, value;
 757
 758       if (c != '(')
 759         fatal_expected_char ('(', c);
 760
 761       read_name (&name);
 762       read_name (&value);
 763       add_constant (defs, xstrdup (name.string), xstrdup (value.string), 0);
 764
 765       c = read_skip_spaces ();
 766       if (c != ')')
 767         fatal_expected_char (')', c);
 768     }
 769   md_constants = defs;
 770 }
 771
 772 /* For every constant definition, call CALLBACK with two arguments:
 773    a pointer a pointer to the constant definition and INFO.
 774    Stop when CALLBACK returns zero.  */
 775
 776 void
 777 traverse_md_constants (htab_trav callback, void *info)
 778 {
 779   htab_traverse (md_constants, callback, info);
 780 }
 781
 782 /* Return a malloc()ed decimal string that represents number NUMBER.  */
 783
 784 static char *
 785 decimal_string (int number)
 786 {
 787   /* A safe overestimate.  +1 for sign, +1 for null terminator.  */
 788   char buffer[sizeof (int) * CHAR_BIT + 1 + 1];
 789
 790   sprintf (buffer, "%d", number);
 791   return xstrdup (buffer);
 792 }
 793
 794 /* Process a define_enum or define_c_enum directive, starting with
 795    the optional space after the "define_enum".  LINENO is the line
 796    number on which the directive started and MD_P is true if the
 797    directive is a define_enum rather than a define_c_enum.  */
 798
 799 static void
 800 handle_enum (int lineno, bool md_p)
 801 {
 802   char *enum_name, *value_name;
 803   struct md_name name;
 804   struct enum_type *def;
 805   struct enum_value *ev;
 806   void **slot;
 807   int c;
 808
 809   enum_name = read_string (false);
 810   slot = htab_find_slot (enum_types, &enum_name, INSERT);
 811   if (*slot)
 812     {
 813       def = (struct enum_type *) *slot;
 814       if (def->md_p != md_p)
 815         error_with_line (lineno, "redefining `%s' as a different type of enum",
 816                          enum_name);
 817     }
 818   else
 819     {
 820       def = XNEW (struct enum_type);
 821       def->name = enum_name;
 822       def->md_p = md_p;
 823       def->values = 0;
 824       def->tail_ptr = &def->values;
 825       def->num_values = 0;
 826       *slot = def;
 827     }
 828
 829   c = read_skip_spaces ();
 830   if (c != '[')
 831     fatal_expected_char ('[', c);
 832
 833   while ((c = read_skip_spaces ()) != ']')
 834     {
 835       if (c == EOF)
 836         {
 837           error_with_line (lineno, "unterminated construct");
 838           exit (1);
 839         }
 840       unread_char (c);
 841       read_name (&name);
 842
 843       ev = XNEW (struct enum_value);
 844       ev->next = 0;
 845       if (md_p)
 846         {
 847           value_name = concat (def->name, "_", name.string, NULL);
 848           upcase_string (value_name);
 849           ev->name = xstrdup (name.string);
 850         }
 851       else
 852         {
 853           value_name = xstrdup (name.string);
 854           ev->name = value_name;
 855         }
 856       ev->def = add_constant (md_constants, value_name,
 857                               decimal_string (def->num_values), def);
 858
 859       *def->tail_ptr = ev;
 860       def->tail_ptr = &ev->next;
 861       def->num_values++;
 862     }
 863 }
 864
 865 /* Try to find the definition of the given enum.  Return null on failure.  */
 866
 867 struct enum_type *
 868 lookup_enum_type (const char *name)
 869 {
 870   return (struct enum_type *) htab_find (enum_types, &name);
 871 }
 872
 873 /* For every enum definition, call CALLBACK with two arguments:
 874    a pointer to the constant definition and INFO.  Stop when CALLBACK
 875    returns zero.  */
 876
 877 void
 878 traverse_enum_types (htab_trav callback, void *info)
 879 {
 880   htab_traverse (enum_types, callback, info);
 881 }
 882
 883 /* Process an "include" directive, starting with the optional space
 884    after the "include".  Read in the file and use HANDLE_DIRECTIVE
 885    to process each unknown directive.  LINENO is the line number on
 886    which the "include" occured.  */
 887
 888 static void
 889 handle_include (int lineno, directive_handler_t handle_directive)
 890 {
 891   const char *filename;
 892   const char *old_filename;
 893   int old_lineno;
 894   char *pathname;
 895   FILE *input_file, *old_file;
 896
 897   filename = read_string (false);
 898   input_file = NULL;
 899
 900   /* If the specified file name is absolute, skip the include stack.  */
 901   if (!IS_ABSOLUTE_PATH (filename))
 902     {
 903       struct file_name_list *stackp;
 904
 905       /* Search the directory path, trying to open the file.  */
 906       for (stackp = first_dir_md_include; stackp; stackp = stackp->next)
 907         {
 908           static const char sep[2] = { DIR_SEPARATOR, '\0' };
 909
 910           pathname = concat (stackp->fname, sep, filename, NULL);
 911           input_file = fopen (pathname, "r");
 912           if (input_file != NULL)
 913             break;
 914           free (pathname);
 915         }
 916     }
 917
 918   /* If we haven't managed to open the file yet, try combining the
 919      filename with BASE_DIR.  */
 920   if (input_file == NULL)
 921     {
 922       if (base_dir)
 923         pathname = concat (base_dir, filename, NULL);
 924       else
 925         pathname = xstrdup (filename);
 926       input_file = fopen (pathname, "r");
 927     }
 928
 929   if (input_file == NULL)
 930     {
 931       free (pathname);
 932       error_with_line (lineno, "include file `%s' not found", filename);
 933       return;
 934     }
 935
 936   /* Save the old cursor.  Note that the LINENO argument to this
 937      function is the beginning of the include statement, while
 938      read_md_lineno has already been advanced.  */
 939   old_file = read_md_file;
 940   old_filename = read_md_filename;
 941   old_lineno = read_md_lineno;
 942
 943   if (include_callback)
 944     include_callback (pathname);
 945
 946   read_md_file = input_file;
 947   read_md_filename = pathname;
 948   handle_file (handle_directive);
 949
 950   /* Restore the old cursor.  */
 951   read_md_file = old_file;
 952   read_md_filename = old_filename;
 953   read_md_lineno = old_lineno;
 954
 955   /* Do not free the pathname.  It is attached to the various rtx
 956      queue elements.  */
 957 }
 958
 959 /* Process the current file, assuming that read_md_file and
 960    read_md_filename are valid.  Use HANDLE_DIRECTIVE to handle
 961    unknown directives.  */
 962
 963 static void
 964 handle_file (directive_handler_t handle_directive)
 965 {
 966   struct md_name directive;
 967   int c, lineno;
 968
 969   read_md_lineno = 1;
 970   while ((c = read_skip_spaces ()) != EOF)
 971     {
 972       lineno = read_md_lineno;
 973       if (c != '(')
 974         fatal_expected_char ('(', c);
 975
 976       read_name (&directive);
 977       if (strcmp (directive.string, "define_constants") == 0)
 978         handle_constants ();
 979       else if (strcmp (directive.string, "define_enum") == 0)
 980         handle_enum (lineno, true);
 981       else if (strcmp (directive.string, "define_c_enum") == 0)
 982         handle_enum (lineno, false);
 983       else if (strcmp (directive.string, "include") == 0)
 984         handle_include (lineno, handle_directive);
 985       else if (handle_directive)
 986         handle_directive (lineno, directive.string);
 987       else
 988         read_skip_construct (1, lineno);
 989
 990       c = read_skip_spaces ();
 991       if (c != ')')
 992         fatal_expected_char (')', c);
 993     }
 994   fclose (read_md_file);
 995 }
 996
 997 /* Like handle_file, but for top-level files.  Set up in_fname and
 998    base_dir accordingly.  */
 999
1000 static void
1001 handle_toplevel_file (directive_handler_t handle_directive)
1002 {
1003   const char *base;
1004
1005   in_fname = read_md_filename;
1006   base = lbasename (in_fname);
1007   if (base == in_fname)
1008     base_dir = NULL;
1009   else
1010     base_dir = xstrndup (in_fname, base - in_fname);
1011
1012   handle_file (handle_directive);
1013 }
1014
1015 /* Parse a -I option with argument ARG.  */
1016
1017 static void
1018 parse_include (const char *arg)
1019 {
1020   struct file_name_list *dirtmp;
1021
1022   dirtmp = XNEW (struct file_name_list);
1023   dirtmp->next = 0;
1024   dirtmp->fname = arg;
1025   *last_dir_md_include_ptr = dirtmp;
1026   last_dir_md_include_ptr = &dirtmp->next;
1027   if (strlen (dirtmp->fname) > max_include_len)
1028     max_include_len = strlen (dirtmp->fname);
1029 }
1030
1031 /* The main routine for reading .md files.  Try to process all the .md
1032    files specified on the command line and return true if no error occured.
1033
1034    ARGC and ARGV are the arguments to main.
1035
1036    PARSE_OPT, if nonnull, is passed all unknown command-line arguments.
1037    It should return true if it recognizes the argument or false if a
1038    generic error should be reported.
1039
1040    If HANDLE_DIRECTIVE is nonnull, the parser calls it for each
1041    unknown directive, otherwise it just skips such directives.
1042    See the comment above the directive_handler_t definition for
1043    details about the callback's interface.  */
1044
1045 bool
1046 read_md_files (int argc, char **argv, bool (*parse_opt) (const char *),
1047                directive_handler_t handle_directive)
1048 {
1049   int i;
1050   bool no_more_options;
1051   bool already_read_stdin;
1052   int num_files;
1053
1054   /* Initialize global data.  */
1055   obstack_init (&string_obstack);
1056   ptr_locs = htab_create (161, leading_ptr_hash, leading_ptr_eq_p, 0);
1057   obstack_init (&ptr_loc_obstack);
1058   joined_conditions = htab_create (161, leading_ptr_hash, leading_ptr_eq_p, 0);
1059   obstack_init (&joined_conditions_obstack);
1060   md_constants = htab_create (31, leading_string_hash,
1061                               leading_string_eq_p, (htab_del) 0);
1062   enum_types = htab_create (31, leading_string_hash,
1063                             leading_string_eq_p, (htab_del) 0);
1064
1065   /* Unlock the stdio streams.  */
1066   unlock_std_streams ();
1067
1068   /* First we loop over all the options.  */
1069   for (i = 1; i < argc; i++)
1070     if (argv[i][0] == '-')
1071       {
1072         /* An argument consisting of exactly one dash is a request to
1073            read stdin.  This will be handled in the second loop.  */
1074         if (argv[i][1] == '\0')
1075           continue;
1076
1077         /* An argument consisting of just two dashes causes option
1078            parsing to cease.  */
1079         if (argv[i][1] == '-' && argv[i][2] == '\0')
1080           break;
1081
1082         if (argv[i][1] == 'I')
1083           {
1084             if (argv[i][2] != '\0')
1085               parse_include (argv[i] + 2);
1086             else if (++i < argc)
1087               parse_include (argv[i]);
1088             else
1089               fatal ("directory name missing after -I option");
1090             continue;
1091           }
1092
1093         /* The program may have provided a callback so it can
1094            accept its own options.  */
1095         if (parse_opt && parse_opt (argv[i]))
1096           continue;
1097
1098         fatal ("invalid option `%s'", argv[i]);
1099       }
1100
1101   /* Now loop over all input files.  */
1102   num_files = 0;
1103   no_more_options = false;
1104   already_read_stdin = false;
1105   for (i = 1; i < argc; i++)
1106     {
1107       if (argv[i][0] == '-')
1108         {
1109           if (argv[i][1] == '\0')
1110             {
1111               /* Read stdin.  */
1112               if (already_read_stdin)
1113                 fatal ("cannot read standard input twice");
1114
1115               read_md_file = stdin;
1116               read_md_filename = "<stdin>";
1117               handle_toplevel_file (handle_directive);
1118               already_read_stdin = true;
1119               continue;
1120             }
1121           else if (argv[i][1] == '-' && argv[i][2] == '\0')
1122             {
1123               /* No further arguments are to be treated as options.  */
1124               no_more_options = true;
1125               continue;
1126             }
1127           else if (!no_more_options)
1128             continue;
1129         }
1130
1131       /* If we get here we are looking at a non-option argument, i.e.
1132          a file to be processed.  */
1133       read_md_filename = argv[i];
1134       read_md_file = fopen (read_md_filename, "r");
1135       if (read_md_file == 0)
1136         {
1137           perror (read_md_filename);
1138           return false;
1139         }
1140       handle_toplevel_file (handle_directive);
1141       num_files++;
1142     }
1143
1144   /* If we get to this point without having seen any files to process,
1145      read the standard input now.  */
1146   if (num_files == 0 && !already_read_stdin)
1147     {
1148       read_md_file = stdin;
1149       read_md_filename = "<stdin>";
1150       handle_toplevel_file (handle_directive);
1151     }
1152
1153   return !have_error;
1154 }