gcc/godump.c

   1 /* Output Go language descriptions of types.
   2    Copyright (C) 2008, 2009, 2010, 2011 Free Software Foundation, Inc.
   3    Written by Ian Lance Taylor <iant@google.com>.
   4
   5 This file is part of GCC.
   6
   7 GCC is free software; you can redistribute it and/or modify it under
   8 the terms of the GNU General Public License as published by the Free
   9 Software Foundation; either version 3, or (at your option) any later
  10 version.
  11
  12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  14 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  15 for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with GCC; see the file COPYING3.  If not see
  19 <http://www.gnu.org/licenses/>.  */
  20
  21 /* This file is used during the build process to emit Go language
  22    descriptions of declarations from C header files.  It uses the
  23    debug info hooks to emit the descriptions.  The Go language
  24    descriptions then become part of the Go runtime support
  25    library.
  26
  27    All global names are output with a leading underscore, so that they
  28    are all hidden in Go.  */
  29
  30 #include "config.h"
  31 #include "system.h"
  32 #include "coretypes.h"
  33 #include "diagnostic-core.h"
  34 #include "tree.h"
  35 #include "ggc.h"
  36 #include "pointer-set.h"
  37 #include "obstack.h"
  38 #include "debug.h"
  39
  40 /* We dump this information from the debug hooks.  This gives us a
  41    stable and maintainable API to hook into.  In order to work
  42    correctly when -g is used, we build our own hooks structure which
  43    wraps the hooks we need to change.  */
  44
  45 /* Our debug hooks.  This is initialized by dump_go_spec_init.  */
  46
  47 static struct gcc_debug_hooks go_debug_hooks;
  48
  49 /* The real debug hooks.  */
  50
  51 static const struct gcc_debug_hooks *real_debug_hooks;
  52
  53 /* The file where we should write information.  */
  54
  55 static FILE *go_dump_file;
  56
  57 /* A queue of decls to output.  */
  58
  59 static GTY(()) VEC(tree,gc) *queue;
  60
  61 /* A hash table of macros we have seen.  */
  62
  63 static htab_t macro_hash;
  64
  65 /* The type of a value in macro_hash.  */
  66
  67 struct macro_hash_value
  68 {
  69   /* The name stored in the hash table.  */
  70   char *name;
  71   /* The value of the macro.  */
  72   char *value;
  73 };
  74
  75 /* Calculate the hash value for an entry in the macro hash table.  */
  76
  77 static hashval_t
  78 macro_hash_hashval (const void *val)
  79 {
  80   const struct macro_hash_value *mhval = (const struct macro_hash_value *) val;
  81   return htab_hash_string (mhval->name);
  82 }
  83
  84 /* Compare values in the macro hash table for equality.  */
  85
  86 static int
  87 macro_hash_eq (const void *v1, const void *v2)
  88 {
  89   const struct macro_hash_value *mhv1 = (const struct macro_hash_value *) v1;
  90   const struct macro_hash_value *mhv2 = (const struct macro_hash_value *) v2;
  91   return strcmp (mhv1->name, mhv2->name) == 0;
  92 }
  93
  94 /* Free values deleted from the macro hash table.  */
  95
  96 static void
  97 macro_hash_del (void *v)
  98 {
  99   struct macro_hash_value *mhv = (struct macro_hash_value *) v;
 100   XDELETEVEC (mhv->name);
 101   XDELETEVEC (mhv->value);
 102   XDELETE (mhv);
 103 }
 104
 105 /* For the string hash tables.  */
 106
 107 static int
 108 string_hash_eq (const void *y1, const void *y2)
 109 {
 110   return strcmp ((const char *) y1, (const char *) y2) == 0;
 111 }
 112
 113 /* A macro definition.  */
 114
 115 static void
 116 go_define (unsigned int lineno, const char *buffer)
 117 {
 118   const char *p;
 119   const char *name_end;
 120   size_t out_len;
 121   char *out_buffer;
 122   char *q;
 123   bool saw_operand;
 124   bool need_operand;
 125   struct macro_hash_value *mhval;
 126   char *copy;
 127   hashval_t hashval;
 128   void **slot;
 129
 130   real_debug_hooks->define (lineno, buffer);
 131
 132   /* Skip macro functions.  */
 133   for (p = buffer; *p != '\0' && *p != ' '; ++p)
 134     if (*p == '(')
 135       return;
 136
 137   if (*p == '\0')
 138     return;
 139
 140   name_end = p;
 141
 142   ++p;
 143   if (*p == '\0')
 144     return;
 145
 146   copy = XNEWVEC (char, name_end - buffer + 1);
 147   memcpy (copy, buffer, name_end - buffer);
 148   copy[name_end - buffer] = '\0';
 149
 150   mhval = XNEW (struct macro_hash_value);
 151   mhval->name = copy;
 152   mhval->value = NULL;
 153
 154   hashval = htab_hash_string (copy);
 155   slot = htab_find_slot_with_hash (macro_hash, mhval, hashval, NO_INSERT);
 156
 157   /* For simplicity, we force all names to be hidden by adding an
 158      initial underscore, and let the user undo this as needed.  */
 159   out_len = strlen (p) * 2 + 1;
 160   out_buffer = XNEWVEC (char, out_len);
 161   q = out_buffer;
 162   saw_operand = false;
 163   need_operand = false;
 164   while (*p != '\0')
 165     {
 166       switch (*p)
 167         {
 168         case 'A': case 'B': case 'C': case 'D': case 'E': case 'F':
 169         case 'G': case 'H': case 'I': case 'J': case 'K': case 'L':
 170         case 'M': case 'N': case 'O': case 'P': case 'Q': case 'R':
 171         case 'S': case 'T': case 'U': case 'V': case 'W': case 'X':
 172         case 'Y': case 'Z':
 173         case 'a': case 'b': case 'c': case 'd': case 'e': case 'f':
 174         case 'g': case 'h': case 'i': case 'j': case 'k': case 'l':
 175         case 'm': case 'n': case 'o': case 'p': case 'q': case 'r':
 176         case 's': case 't': case 'u': case 'v': case 'w': case 'x':
 177         case 'y': case 'z':
 178         case '_':
 179           {
 180             /* The start of an identifier.  Technically we should also
 181                worry about UTF-8 identifiers, but they are not a
 182                problem for practical uses of -fdump-go-spec so we
 183                don't worry about them.  */
 184             const char *start;
 185             char *n;
 186             struct macro_hash_value idval;
 187
 188             if (saw_operand)
 189               goto unknown;
 190
 191             start = p;
 192             while (ISALNUM (*p) || *p == '_')
 193               ++p;
 194             n = XALLOCAVEC (char, p - start + 1);
 195             memcpy (n, start, p - start);
 196             n[p - start] = '\0';
 197             idval.name = n;
 198             idval.value = NULL;
 199             if (htab_find (macro_hash, &idval) == NULL)
 200               {
 201                 /* This is a reference to a name which was not defined
 202                    as a macro.  */
 203                 goto unknown;
 204               }
 205
 206             *q++ = '_';
 207             memcpy (q, start, p - start);
 208             q += p - start;
 209
 210             saw_operand = true;
 211             need_operand = false;
 212           }
 213           break;
 214
 215         case '.':
 216           if (!ISDIGIT (p[1]))
 217             goto unknown;
 218           /* Fall through.  */
 219         case '0': case '1': case '2': case '3': case '4':
 220         case '5': case '6': case '7': case '8': case '9':
 221           {
 222             const char *start;
 223             bool is_hex;
 224
 225             start = p;
 226             is_hex = false;
 227             if (*p == '0' && (p[1] == 'x' || p[1] == 'X'))
 228               {
 229                 p += 2;
 230                 is_hex = true;
 231               }
 232             while (ISDIGIT (*p) || *p == '.' || *p == 'e' || *p == 'E'
 233                    || (is_hex
 234                        && ((*p >= 'a' && *p <= 'f')
 235                            || (*p >= 'A' && *p <= 'F'))))
 236               ++p;
 237             memcpy (q, start, p - start);
 238             q += p - start;
 239             while (*p == 'u' || *p == 'U' || *p == 'l' || *p == 'L'
 240                    || *p == 'f' || *p == 'F'
 241                    || *p == 'd' || *p == 'D')
 242               {
 243                 /* Go doesn't use any of these trailing type
 244                    modifiers.  */
 245                 ++p;
 246               }
 247
 248             /* We'll pick up the exponent, if any, as an
 249                expression.  */
 250
 251             saw_operand = true;
 252             need_operand = false;
 253           }
 254           break;
 255
 256         case ' ': case '\t':
 257           *q++ = *p++;
 258           break;
 259
 260         case '(':
 261           /* Always OK, not part of an operand, presumed to start an
 262              operand.  */
 263           *q++ = *p++;
 264           saw_operand = false;
 265           need_operand = false;
 266           break;
 267
 268         case ')':
 269           /* OK if we don't need an operand, and presumed to indicate
 270              an operand.  */
 271           if (need_operand)
 272             goto unknown;
 273           *q++ = *p++;
 274           saw_operand = true;
 275           break;
 276
 277         case '+': case '-':
 278           /* Always OK, but not part of an operand.  */
 279           *q++ = *p++;
 280           saw_operand = false;
 281           break;
 282
 283         case '*': case '/': case '%': case '|': case '&': case '^':
 284           /* Must be a binary operator.  */
 285           if (!saw_operand)
 286             goto unknown;
 287           *q++ = *p++;
 288           saw_operand = false;
 289           need_operand = true;
 290           break;
 291
 292         case '=':
 293           *q++ = *p++;
 294           if (*p != '=')
 295             goto unknown;
 296           /* Must be a binary operator.  */
 297           if (!saw_operand)
 298             goto unknown;
 299           *q++ = *p++;
 300           saw_operand = false;
 301           need_operand = true;
 302           break;
 303
 304         case '!':
 305           *q++ = *p++;
 306           if (*p == '=')
 307             {
 308               /* Must be a binary operator.  */
 309               if (!saw_operand)
 310                 goto unknown;
 311               *q++ = *p++;
 312               saw_operand = false;
 313               need_operand = true;
 314             }
 315           else
 316             {
 317               /* Must be a unary operator.  */
 318               if (saw_operand)
 319                 goto unknown;
 320               need_operand = true;
 321             }
 322           break;
 323
 324         case '<': case '>':
 325           /* Must be a binary operand, may be << or >> or <= or >=.  */
 326           if (!saw_operand)
 327             goto unknown;
 328           *q++ = *p++;
 329           if (*p == *(p - 1) || *p == '=')
 330             *q++ = *p++;
 331           saw_operand = false;
 332           need_operand = true;
 333           break;
 334
 335         case '~':
 336           /* Must be a unary operand, must be translated for Go.  */
 337           if (saw_operand)
 338             goto unknown;
 339           *q++ = '^';
 340           p++;
 341           need_operand = true;
 342           break;
 343
 344         case '"':
 345         case '\'':
 346           {
 347             char quote;
 348             int count;
 349
 350             if (saw_operand)
 351               goto unknown;
 352             quote = *p;
 353             *q++ = *p++;
 354             count = 0;
 355             while (*p != quote)
 356               {
 357                 int c;
 358
 359                 if (*p == '\0')
 360                   goto unknown;
 361
 362                 ++count;
 363
 364                 if (*p != '\\')
 365                   {
 366                     *q++ = *p++;
 367                     continue;
 368                   }
 369
 370                 *q++ = *p++;
 371                 switch (*p)
 372                   {
 373                   case '0': case '1': case '2': case '3':
 374                   case '4': case '5': case '6': case '7':
 375                     c = 0;
 376                     while (*p >= '0' && *p <= '7')
 377                       {
 378                         *q++ = *p++;
 379                         ++c;
 380                       }
 381                     /* Go octal characters are always 3
 382                        digits.  */
 383                     if (c != 3)
 384                       goto unknown;
 385                     break;
 386
 387                   case 'x':
 388                     *q++ = *p++;
 389                     c = 0;
 390                     while (ISXDIGIT (*p))
 391                       {
 392                         *q++ = *p++;
 393                         ++c;
 394                       }
 395                     /* Go hex characters are always 2 digits.  */
 396                     if (c != 2)
 397                       goto unknown;
 398                     break;
 399
 400                   case 'a': case 'b': case 'f': case 'n': case 'r':
 401                   case 't': case 'v': case '\\': case '\'': case '"':
 402                     *q++ = *p++;
 403                     break;
 404
 405                   default:
 406                     goto unknown;
 407                   }
 408               }
 409
 410             *q++ = *p++;
 411
 412             if (quote == '\'' && count != 1)
 413               goto unknown;
 414
 415             saw_operand = true;
 416             need_operand = false;
 417
 418             break;
 419           }
 420
 421         default:
 422           goto unknown;
 423         }
 424     }
 425
 426   if (need_operand)
 427     goto unknown;
 428
 429   gcc_assert ((size_t) (q - out_buffer) < out_len);
 430   *q = '\0';
 431
 432   mhval->value = out_buffer;
 433
 434   if (slot == NULL)
 435     {
 436       slot = htab_find_slot_with_hash (macro_hash, mhval, hashval, INSERT);
 437       gcc_assert (slot != NULL && *slot == NULL);
 438     }
 439   else
 440     {
 441       if (*slot != NULL)
 442         macro_hash_del (*slot);
 443     }
 444
 445   *slot = mhval;
 446
 447   return;
 448
 449  unknown:
 450   fprintf (go_dump_file, "// unknowndefine %s\n", buffer);
 451   if (slot != NULL)
 452     htab_clear_slot (macro_hash, slot);
 453   XDELETEVEC (out_buffer);
 454   XDELETEVEC (copy);
 455 }
 456
 457 /* A macro undef.  */
 458
 459 static void
 460 go_undef (unsigned int lineno, const char *buffer)
 461 {
 462   struct macro_hash_value mhval;
 463   void **slot;
 464
 465   real_debug_hooks->undef (lineno, buffer);
 466
 467   mhval.name = CONST_CAST (char *, buffer);
 468   mhval.value = NULL;
 469   slot = htab_find_slot (macro_hash, &mhval, NO_INSERT);
 470   if (slot != NULL)
 471     htab_clear_slot (macro_hash, slot);
 472 }
 473
 474 /* A function or variable decl.  */
 475
 476 static void
 477 go_decl (tree decl)
 478 {
 479   if (!TREE_PUBLIC (decl)
 480       || DECL_IS_BUILTIN (decl)
 481       || DECL_NAME (decl) == NULL_TREE)
 482     return;
 483   VEC_safe_push (tree, gc, queue, decl);
 484 }
 485
 486 /* A function decl.  */
 487
 488 static void
 489 go_function_decl (tree decl)
 490 {
 491   real_debug_hooks->function_decl (decl);
 492   go_decl (decl);
 493 }
 494
 495 /* A global variable decl.  */
 496
 497 static void
 498 go_global_decl (tree decl)
 499 {
 500   real_debug_hooks->global_decl (decl);
 501   go_decl (decl);
 502 }
 503
 504 /* A type declaration.  */
 505
 506 static void
 507 go_type_decl (tree decl, int local)
 508 {
 509   real_debug_hooks->type_decl (decl, local);
 510
 511   if (local || DECL_IS_BUILTIN (decl))
 512     return;
 513   if (DECL_NAME (decl) == NULL_TREE
 514       && (TYPE_NAME (TREE_TYPE (decl)) == NULL_TREE
 515           || TREE_CODE (TYPE_NAME (TREE_TYPE (decl))) != IDENTIFIER_NODE)
 516       && TREE_CODE (TREE_TYPE (decl)) != ENUMERAL_TYPE)
 517     return;
 518   VEC_safe_push (tree, gc, queue, decl);
 519 }
 520
 521 /* A container for the data we pass around when generating information
 522    at the end of the compilation.  */
 523
 524 struct godump_container
 525 {
 526   /* DECLs that we have already seen.  */
 527   struct pointer_set_t *decls_seen;
 528
 529   /* Types which may potentially have to be defined as dummy
 530      types.  */
 531   struct pointer_set_t *pot_dummy_types;
 532
 533   /* Go keywords.  */
 534   htab_t keyword_hash;
 535
 536   /* Global type definitions.  */
 537   htab_t type_hash;
 538
 539   /* Invalid types.  */
 540   htab_t invalid_hash;
 541
 542   /* Obstack used to write out a type definition.  */
 543   struct obstack type_obstack;
 544 };
 545
 546 /* Append an IDENTIFIER_NODE to OB.  */
 547
 548 static void
 549 go_append_string (struct obstack *ob, tree id)
 550 {
 551   obstack_grow (ob, IDENTIFIER_POINTER (id), IDENTIFIER_LENGTH (id));
 552 }
 553
 554 /* Write the Go version of TYPE to CONTAINER->TYPE_OBSTACK.
 555    USE_TYPE_NAME is true if we can simply use a type name here without
 556    needing to define it.  IS_FUNC_OK is true if we can output a func
 557    type here; the "func" keyword will already have been added.  Return
 558    true if the type can be represented in Go, false otherwise.  */
 559
 560 static bool
 561 go_format_type (struct godump_container *container, tree type,
 562                 bool use_type_name, bool is_func_ok)
 563 {
 564   bool ret;
 565   struct obstack *ob;
 566
 567   ret = true;
 568   ob = &container->type_obstack;
 569
 570   if (TYPE_NAME (type) != NULL_TREE
 571       && (pointer_set_contains (container->decls_seen, type)
 572           || pointer_set_contains (container->decls_seen, TYPE_NAME (type)))
 573       && (AGGREGATE_TYPE_P (type)
 574           || POINTER_TYPE_P (type)
 575           || TREE_CODE (type) == FUNCTION_TYPE))
 576     {
 577       tree name;
 578       void **slot;
 579
 580       name = TYPE_NAME (type);
 581       if (TREE_CODE (name) == TYPE_DECL)
 582         name = DECL_NAME (name);
 583
 584       slot = htab_find_slot (container->invalid_hash, IDENTIFIER_POINTER (name),
 585                              NO_INSERT);
 586       if (slot != NULL)
 587         ret = false;
 588
 589       obstack_1grow (ob, '_');
 590       go_append_string (ob, name);
 591       return ret;
 592     }
 593
 594   pointer_set_insert (container->decls_seen, type);
 595
 596   switch (TREE_CODE (type))
 597     {
 598     case ENUMERAL_TYPE:
 599       obstack_grow (ob, "int", 3);
 600       break;
 601
 602     case TYPE_DECL:
 603       {
 604         void **slot;
 605
 606         slot = htab_find_slot (container->invalid_hash,
 607                                IDENTIFIER_POINTER (DECL_NAME (type)),
 608                                NO_INSERT);
 609         if (slot != NULL)
 610           ret = false;
 611
 612         obstack_1grow (ob, '_');
 613         go_append_string (ob, DECL_NAME (type));
 614       }
 615       break;
 616
 617     case INTEGER_TYPE:
 618       {
 619         const char *s;
 620         char buf[100];
 621
 622         switch (TYPE_PRECISION (type))
 623           {
 624           case 8:
 625             s = TYPE_UNSIGNED (type) ? "uint8" : "int8";
 626             break;
 627           case 16:
 628             s = TYPE_UNSIGNED (type) ? "uint16" : "int16";
 629             break;
 630           case 32:
 631             s = TYPE_UNSIGNED (type) ? "uint32" : "int32";
 632             break;
 633           case 64:
 634             s = TYPE_UNSIGNED (type) ? "uint64" : "int64";
 635             break;
 636           default:
 637             snprintf (buf, sizeof buf, "INVALID-int-%u%s",
 638                       TYPE_PRECISION (type),
 639                       TYPE_UNSIGNED (type) ? "u" : "");
 640             s = buf;
 641             ret = false;
 642             break;
 643           }
 644         obstack_grow (ob, s, strlen (s));
 645       }
 646       break;
 647
 648     case REAL_TYPE:
 649       {
 650         const char *s;
 651         char buf[100];
 652
 653         switch (TYPE_PRECISION (type))
 654           {
 655           case 32:
 656             s = "float32";
 657             break;
 658           case 64:
 659             s = "float64";
 660             break;
 661           default:
 662             snprintf (buf, sizeof buf, "INVALID-float-%u",
 663                       TYPE_PRECISION (type));
 664             s = buf;
 665             ret = false;
 666             break;
 667           }
 668         obstack_grow (ob, s, strlen (s));
 669       }
 670       break;
 671
 672     case BOOLEAN_TYPE:
 673       obstack_grow (ob, "bool", 4);
 674       break;
 675
 676     case POINTER_TYPE:
 677       if (use_type_name
 678           && TYPE_NAME (TREE_TYPE (type)) != NULL_TREE
 679           && (RECORD_OR_UNION_TYPE_P (TREE_TYPE (type))
 680               || (POINTER_TYPE_P (TREE_TYPE (type))
 681                   && (TREE_CODE (TREE_TYPE (TREE_TYPE (type)))
 682                       == FUNCTION_TYPE))))
 683         {
 684           tree name;
 685           void **slot;
 686
 687           name = TYPE_NAME (TREE_TYPE (type));
 688           if (TREE_CODE (name) == TYPE_DECL)
 689             name = DECL_NAME (name);
 690
 691           slot = htab_find_slot (container->invalid_hash,
 692                                  IDENTIFIER_POINTER (name), NO_INSERT);
 693           if (slot != NULL)
 694             ret = false;
 695
 696           obstack_grow (ob, "*_", 2);
 697           go_append_string (ob, name);
 698
 699           /* The pointer here can be used without the struct or union
 700              definition.  So this struct or union is a potential dummy
 701              type.  */
 702           if (RECORD_OR_UNION_TYPE_P (TREE_TYPE (type)))
 703             pointer_set_insert (container->pot_dummy_types,
 704                                 IDENTIFIER_POINTER (name));
 705
 706           return ret;
 707         }
 708       if (TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE)
 709         obstack_grow (ob, "func", 4);
 710       else
 711         obstack_1grow (ob, '*');
 712       if (VOID_TYPE_P (TREE_TYPE (type)))
 713         obstack_grow (ob, "byte", 4);
 714       else
 715         {
 716           if (!go_format_type (container, TREE_TYPE (type), use_type_name,
 717                                true))
 718             ret = false;
 719         }
 720       break;
 721
 722     case ARRAY_TYPE:
 723       obstack_1grow (ob, '[');
 724       if (TYPE_DOMAIN (type) != NULL_TREE
 725           && TREE_CODE (TYPE_DOMAIN (type)) == INTEGER_TYPE
 726           && TYPE_MIN_VALUE (TYPE_DOMAIN (type)) != NULL_TREE
 727           && TREE_CODE (TYPE_MIN_VALUE (TYPE_DOMAIN (type))) == INTEGER_CST
 728           && tree_int_cst_sgn (TYPE_MIN_VALUE (TYPE_DOMAIN (type))) == 0
 729           && TYPE_MAX_VALUE (TYPE_DOMAIN (type)) != NULL_TREE
 730           && TREE_CODE (TYPE_MAX_VALUE (TYPE_DOMAIN (type))) == INTEGER_CST
 731           && host_integerp (TYPE_MAX_VALUE (TYPE_DOMAIN (type)), 0))
 732         {
 733           char buf[100];
 734
 735           snprintf (buf, sizeof buf, HOST_WIDE_INT_PRINT_DEC "+1",
 736                     tree_low_cst (TYPE_MAX_VALUE (TYPE_DOMAIN (type)), 0));
 737           obstack_grow (ob, buf, strlen (buf));
 738         }
 739       obstack_1grow (ob, ']');
 740       if (!go_format_type (container, TREE_TYPE (type), use_type_name, false))
 741         ret = false;
 742       break;
 743
 744     case UNION_TYPE:
 745     case RECORD_TYPE:
 746       {
 747         tree field;
 748         int i;
 749
 750         obstack_grow (ob, "struct { ", 9);
 751         i = 0;
 752         for (field = TYPE_FIELDS (type);
 753              field != NULL_TREE;
 754              field = TREE_CHAIN (field))
 755           {
 756             struct obstack hold_type_obstack;
 757             bool field_ok;
 758
 759             if (TREE_CODE (type) == UNION_TYPE)
 760               {
 761                 hold_type_obstack = container->type_obstack;
 762                 obstack_init (&container->type_obstack);
 763               }
 764
 765             field_ok = true;
 766
 767             if (DECL_NAME (field) == NULL)
 768               {
 769                 char buf[100];
 770
 771                 obstack_grow (ob, "Godump_", 7);
 772                 snprintf (buf, sizeof buf, "%d", i);
 773                 obstack_grow (ob, buf, strlen (buf));
 774                 i++;
 775               }
 776             else
 777               {
 778                 const char *var_name;
 779                 void **slot;
 780
 781                 /* Start variable name with an underscore if a keyword.  */
 782                 var_name = IDENTIFIER_POINTER (DECL_NAME (field));
 783                 slot = htab_find_slot (container->keyword_hash, var_name,
 784                                        NO_INSERT);
 785                 if (slot != NULL)
 786                   obstack_1grow (ob, '_');
 787                 go_append_string (ob, DECL_NAME (field));
 788               }
 789             obstack_1grow (ob, ' ');
 790             if (DECL_BIT_FIELD (field))
 791               {
 792                 obstack_grow (ob, "INVALID-bit-field", 17);
 793                 field_ok = false;
 794               }
 795             else
 796               {
 797                 /* Do not expand type if a record or union type or a
 798                    function pointer.  */
 799                 if (TYPE_NAME (TREE_TYPE (field)) != NULL_TREE
 800                     && (RECORD_OR_UNION_TYPE_P (TREE_TYPE (field))
 801                         || (POINTER_TYPE_P (TREE_TYPE (field))
 802                             && (TREE_CODE (TREE_TYPE (TREE_TYPE (field)))
 803                                 == FUNCTION_TYPE))))
 804                   {
 805                     tree name;
 806                     void **slot;
 807
 808                     name = TYPE_NAME (TREE_TYPE (field));
 809                     if (TREE_CODE (name) == TYPE_DECL)
 810                       name = DECL_NAME (name);
 811
 812                     slot = htab_find_slot (container->invalid_hash,
 813                                            IDENTIFIER_POINTER (name),
 814                                            NO_INSERT);
 815                     if (slot != NULL)
 816                       field_ok = false;
 817
 818                     obstack_1grow (ob, '_');
 819                     go_append_string (ob, name);
 820                   }
 821                 else
 822                   {
 823                     if (!go_format_type (container, TREE_TYPE (field), true,
 824                                          false))
 825                       field_ok = false;
 826                   }
 827               }
 828             obstack_grow (ob, "; ", 2);
 829
 830             /* Only output the first successful field of a union, and
 831                hope for the best.  */
 832             if (TREE_CODE (type) == UNION_TYPE)
 833               {
 834                 if (!field_ok && TREE_CHAIN (field) == NULL_TREE)
 835                   {
 836                     field_ok = true;
 837                     ret = false;
 838                   }
 839                 if (field_ok)
 840                   {
 841                     unsigned int sz;
 842
 843                     sz = obstack_object_size (&container->type_obstack);
 844                     obstack_grow (&hold_type_obstack,
 845                                   obstack_base (&container->type_obstack),
 846                                   sz);
 847                   }
 848                 obstack_free (&container->type_obstack, NULL);
 849                 container->type_obstack = hold_type_obstack;
 850                 if (field_ok)
 851                   break;
 852               }
 853             else
 854               {
 855                 if (!field_ok)
 856                   ret = false;
 857               }
 858           }
 859         obstack_1grow (ob, '}');
 860       }
 861       break;
 862
 863     case FUNCTION_TYPE:
 864       {
 865         tree arg_type;
 866         bool is_varargs;
 867         tree result;
 868         function_args_iterator iter;
 869         bool seen_arg;
 870
 871         /* Go has no way to write a type which is a function but not a
 872            pointer to a function.  */
 873         if (!is_func_ok)
 874           {
 875             obstack_grow (ob, "func*", 5);
 876             ret = false;
 877           }
 878
 879         obstack_1grow (ob, '(');
 880         is_varargs = stdarg_p (type);
 881         seen_arg = false;
 882         FOREACH_FUNCTION_ARGS (type, arg_type, iter)
 883           {
 884             if (VOID_TYPE_P (arg_type))
 885               break;
 886             if (seen_arg)
 887               obstack_grow (ob, ", ", 2);
 888             if (!go_format_type (container, arg_type, true, false))
 889               ret = false;
 890             seen_arg = true;
 891           }
 892         if (is_varargs)
 893           {
 894             if (prototype_p (type))
 895               obstack_grow (ob, ", ", 2);
 896             obstack_grow (ob, "...interface{}", 14);
 897           }
 898         obstack_1grow (ob, ')');
 899
 900         result = TREE_TYPE (type);
 901         if (!VOID_TYPE_P (result))
 902           {
 903             obstack_1grow (ob, ' ');
 904             if (!go_format_type (container, result, use_type_name, false))
 905               ret = false;
 906           }
 907       }
 908       break;
 909
 910     default:
 911       obstack_grow (ob, "INVALID-type", 12);
 912       ret = false;
 913       break;
 914     }
 915
 916   return ret;
 917 }
 918
 919 /* Output the type which was built on the type obstack, and then free
 920    it.  */
 921
 922 static void
 923 go_output_type (struct godump_container *container)
 924 {
 925   struct obstack *ob;
 926
 927   ob = &container->type_obstack;
 928   obstack_1grow (ob, '\0');
 929   fputs (obstack_base (ob), go_dump_file);
 930   obstack_free (ob, obstack_base (ob));
 931 }
 932
 933 /* Output a function declaration.  */
 934
 935 static void
 936 go_output_fndecl (struct godump_container *container, tree decl)
 937 {
 938   if (!go_format_type (container, TREE_TYPE (decl), false, true))
 939     fprintf (go_dump_file, "// ");
 940   fprintf (go_dump_file, "func _%s ",
 941            IDENTIFIER_POINTER (DECL_NAME (decl)));
 942   go_output_type (container);
 943   fprintf (go_dump_file, " __asm__(\"%s\")\n",
 944            IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl)));
 945 }
 946
 947 /* Output a typedef or something like a struct definition.  */
 948
 949 static void
 950 go_output_typedef (struct godump_container *container, tree decl)
 951 {
 952   /* If we have an enum type, output the enum constants
 953      separately.  */
 954   if (TREE_CODE (TREE_TYPE (decl)) == ENUMERAL_TYPE
 955       && TYPE_SIZE (TREE_TYPE (decl)) != 0
 956       && !pointer_set_contains (container->decls_seen, TREE_TYPE (decl))
 957       && (TYPE_CANONICAL (TREE_TYPE (decl)) == NULL_TREE
 958           || !pointer_set_contains (container->decls_seen,
 959                                     TYPE_CANONICAL (TREE_TYPE (decl)))))
 960     {
 961       tree element;
 962
 963       for (element = TYPE_VALUES (TREE_TYPE (decl));
 964            element != NULL_TREE;
 965            element = TREE_CHAIN (element))
 966         {
 967           const char *name;
 968           struct macro_hash_value *mhval;
 969           void **slot;
 970           char buf[100];
 971
 972           name = IDENTIFIER_POINTER (TREE_PURPOSE (element));
 973
 974           /* Sometimes a name will be defined as both an enum constant
 975              and a macro.  Avoid duplicate definition errors by
 976              treating enum constants as macros.  */
 977           mhval = XNEW (struct macro_hash_value);
 978           mhval->name = xstrdup (name);
 979           mhval->value = NULL;
 980           slot = htab_find_slot (macro_hash, mhval, INSERT);
 981           if (*slot != NULL)
 982             macro_hash_del (*slot);
 983
 984           if (host_integerp (TREE_VALUE (element), 0))
 985             snprintf (buf, sizeof buf, HOST_WIDE_INT_PRINT_DEC,
 986                      tree_low_cst (TREE_VALUE (element), 0));
 987           else if (host_integerp (TREE_VALUE (element), 1))
 988             snprintf (buf, sizeof buf, HOST_WIDE_INT_PRINT_UNSIGNED,
 989                      ((unsigned HOST_WIDE_INT)
 990                       tree_low_cst (TREE_VALUE (element), 1)));
 991           else
 992             snprintf (buf, sizeof buf, HOST_WIDE_INT_PRINT_DOUBLE_HEX,
 993                      ((unsigned HOST_WIDE_INT)
 994                       TREE_INT_CST_HIGH (TREE_VALUE (element))),
 995                      TREE_INT_CST_LOW (TREE_VALUE (element)));
 996
 997           mhval->value = xstrdup (buf);
 998           *slot = mhval;
 999         }
1000       pointer_set_insert (container->decls_seen, TREE_TYPE (decl));
1001       if (TYPE_CANONICAL (TREE_TYPE (decl)) != NULL_TREE)
1002         pointer_set_insert (container->decls_seen,
1003                             TYPE_CANONICAL (TREE_TYPE (decl)));
1004     }
1005
1006   if (DECL_NAME (decl) != NULL_TREE)
1007     {
1008       void **slot;
1009       const char *type;
1010
1011       type = IDENTIFIER_POINTER (DECL_NAME (decl));
1012       /* If type defined already, skip.  */
1013       slot = htab_find_slot (container->type_hash, type, INSERT);
1014       if (*slot != NULL)
1015         return;
1016       *slot = CONST_CAST (void *, (const void *) type);
1017
1018       if (!go_format_type (container, TREE_TYPE (decl), false, false))
1019         {
1020           fprintf (go_dump_file, "// ");
1021           slot = htab_find_slot (container->invalid_hash, type, INSERT);
1022           *slot = CONST_CAST (void *, (const void *) type);
1023         }
1024       fprintf (go_dump_file, "type _%s ",
1025                IDENTIFIER_POINTER (DECL_NAME (decl)));
1026       go_output_type (container);
1027       pointer_set_insert (container->decls_seen, decl);
1028     }
1029   else if (RECORD_OR_UNION_TYPE_P (TREE_TYPE (decl)))
1030     {
1031        void **slot;
1032        const char *type;
1033
1034        type = IDENTIFIER_POINTER (TYPE_NAME (TREE_TYPE ((decl))));
1035        /* If type defined already, skip.  */
1036        slot = htab_find_slot (container->type_hash, type, INSERT);
1037        if (*slot != NULL)
1038          return;
1039        *slot = CONST_CAST (void *, (const void *) type);
1040
1041        if (!go_format_type (container, TREE_TYPE (decl), false, false))
1042          {
1043            fprintf (go_dump_file, "// ");
1044            slot = htab_find_slot (container->invalid_hash, type, INSERT);
1045            *slot = CONST_CAST (void *, (const void *) type);
1046          }
1047        fprintf (go_dump_file, "type _%s ",
1048                IDENTIFIER_POINTER (TYPE_NAME (TREE_TYPE (decl))));
1049        go_output_type (container);
1050     }
1051   else
1052     return;
1053
1054   fprintf (go_dump_file, "\n");
1055 }
1056
1057 /* Output a variable.  */
1058
1059 static void
1060 go_output_var (struct godump_container *container, tree decl)
1061 {
1062   bool is_valid;
1063
1064   if (pointer_set_contains (container->decls_seen, decl)
1065       || pointer_set_contains (container->decls_seen, DECL_NAME (decl)))
1066     return;
1067   pointer_set_insert (container->decls_seen, decl);
1068   pointer_set_insert (container->decls_seen, DECL_NAME (decl));
1069
1070   is_valid = go_format_type (container, TREE_TYPE (decl), true, false);
1071   if (is_valid
1072       && htab_find_slot (container->type_hash,
1073                          IDENTIFIER_POINTER (DECL_NAME (decl)),
1074                          NO_INSERT) != NULL)
1075     {
1076       /* There is already a type with this name, probably from a
1077          struct tag.  Prefer the type to the variable.  */
1078       is_valid = false;
1079     }
1080   if (!is_valid)
1081     fprintf (go_dump_file, "// ");
1082
1083   fprintf (go_dump_file, "var _%s ",
1084            IDENTIFIER_POINTER (DECL_NAME (decl)));
1085   go_output_type (container);
1086   fprintf (go_dump_file, "\n");
1087
1088   /* Sometimes an extern variable is declared with an unknown struct
1089      type.  */
1090   if (TYPE_NAME (TREE_TYPE (decl)) != NULL_TREE
1091       && RECORD_OR_UNION_TYPE_P (TREE_TYPE (decl)))
1092     {
1093       tree type_name = TYPE_NAME (TREE_TYPE (decl));
1094       if (TREE_CODE (type_name) == IDENTIFIER_NODE)
1095         pointer_set_insert (container->pot_dummy_types,
1096                             IDENTIFIER_POINTER (type_name));
1097       else if (TREE_CODE (type_name) == TYPE_DECL)
1098         pointer_set_insert (container->pot_dummy_types,
1099                             IDENTIFIER_POINTER (DECL_NAME (type_name)));
1100     }
1101 }
1102
1103 /* Output the final value of a preprocessor macro or enum constant.
1104    This is called via htab_traverse_noresize.  */
1105
1106 static int
1107 go_print_macro (void **slot, void *arg ATTRIBUTE_UNUSED)
1108 {
1109   struct macro_hash_value *mhval = (struct macro_hash_value *) *slot;
1110   fprintf (go_dump_file, "const _%s = %s\n", mhval->name, mhval->value);
1111   return 1;
1112 }
1113
1114 /* Build a hash table with the Go keywords.  */
1115
1116 static const char * const keywords[] = {
1117   "__asm__", "break", "case", "chan", "const", "continue", "default",
1118   "defer", "else", "fallthrough", "for", "func", "go", "goto", "if",
1119   "import", "interface", "map", "package", "range", "return", "select",
1120   "struct", "switch", "type", "var"
1121 };
1122
1123 static void
1124 keyword_hash_init (struct godump_container *container)
1125 {
1126   size_t i;
1127   size_t count = sizeof (keywords) / sizeof (keywords[0]);
1128   void **slot;
1129
1130   for (i = 0; i < count; i++)
1131     {
1132       slot = htab_find_slot (container->keyword_hash, keywords[i], INSERT);
1133       *slot = CONST_CAST (void *, (const void *) keywords[i]);
1134     }
1135 }
1136
1137 /* Traversing the pot_dummy_types and seeing which types are present
1138    in the global types hash table and creating dummy definitions if
1139    not found.  This function is invoked by pointer_set_traverse.  */
1140
1141 static bool
1142 find_dummy_types (const void *ptr, void *adata)
1143 {
1144   struct godump_container *data = (struct godump_container *) adata;
1145   const char *type = (const char *) ptr;
1146   void **slot;
1147
1148   slot = htab_find_slot (data->type_hash, type, NO_INSERT);
1149   if (slot == NULL)
1150     fprintf (go_dump_file, "type _%s struct {}\n", type);
1151   return true;
1152 }
1153
1154 /* Output symbols.  */
1155
1156 static void
1157 go_finish (const char *filename)
1158 {
1159   struct godump_container container;
1160   unsigned int ix;
1161   tree decl;
1162
1163   real_debug_hooks->finish (filename);
1164
1165   container.decls_seen = pointer_set_create ();
1166   container.pot_dummy_types = pointer_set_create ();
1167   container.type_hash = htab_create (100, htab_hash_string,
1168                                      string_hash_eq, NULL);
1169   container.invalid_hash = htab_create (10, htab_hash_string,
1170                                         string_hash_eq, NULL);
1171   container.keyword_hash = htab_create (50, htab_hash_string,
1172                                         string_hash_eq, NULL);
1173   obstack_init (&container.type_obstack);
1174
1175   keyword_hash_init (&container);
1176
1177   FOR_EACH_VEC_ELT (tree, queue, ix, decl)
1178     {
1179       switch (TREE_CODE (decl))
1180         {
1181         case FUNCTION_DECL:
1182           go_output_fndecl (&container, decl);
1183           break;
1184
1185         case TYPE_DECL:
1186           go_output_typedef (&container, decl);
1187           break;
1188
1189         case VAR_DECL:
1190           go_output_var (&container, decl);
1191           break;
1192
1193         default:
1194           gcc_unreachable();
1195         }
1196     }
1197
1198   htab_traverse_noresize (macro_hash, go_print_macro, NULL);
1199
1200   /* To emit dummy definitions.  */
1201   pointer_set_traverse (container.pot_dummy_types, find_dummy_types,
1202                         (void *) &container);
1203
1204   pointer_set_destroy (container.decls_seen);
1205   pointer_set_destroy (container.pot_dummy_types);
1206   htab_delete (container.type_hash);
1207   htab_delete (container.invalid_hash);
1208   htab_delete (container.keyword_hash);
1209   obstack_free (&container.type_obstack, NULL);
1210
1211   queue = NULL;
1212
1213   if (fclose (go_dump_file) != 0)
1214     error ("could not close Go dump file: %m");
1215   go_dump_file = NULL;
1216 }
1217
1218 /* Set up our hooks.  */
1219
1220 const struct gcc_debug_hooks *
1221 dump_go_spec_init (const char *filename, const struct gcc_debug_hooks *hooks)
1222 {
1223   go_dump_file = fopen (filename, "w");
1224   if (go_dump_file == NULL)
1225     {
1226       error ("could not open Go dump file %qs: %m", filename);
1227       return hooks;
1228     }
1229
1230   go_debug_hooks = *hooks;
1231   real_debug_hooks = hooks;
1232
1233   go_debug_hooks.finish = go_finish;
1234   go_debug_hooks.define = go_define;
1235   go_debug_hooks.undef = go_undef;
1236   go_debug_hooks.function_decl = go_function_decl;
1237   go_debug_hooks.global_decl = go_global_decl;
1238   go_debug_hooks.type_decl = go_type_decl;
1239
1240   macro_hash = htab_create (100, macro_hash_hashval, macro_hash_eq,
1241                             macro_hash_del);
1242
1243   return &go_debug_hooks;
1244 }
1245
1246 #include "gt-godump.h"