gcc/tree-browser.c

   1 /* Tree browser.
   2    Copyright (C) 2002, 2003, 2004 Free Software Foundation, Inc.
   3    Contributed by Sebastian Pop <s.pop@laposte.net>
   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 2, 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 COPYING.  If not, write to the Free
  19 Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
  20 02110-1301, USA.  */
  21
  22 #include "config.h"
  23 #include "system.h"
  24 #include "coretypes.h"
  25 #include "tm.h"
  26 #include "tree.h"
  27 #include "tree-inline.h"
  28 #include "diagnostic.h"
  29 #include "hashtab.h"
  30
  31
  32 #define TB_OUT_FILE stdout
  33 #define TB_IN_FILE stdin
  34 #define TB_NIY fprintf (TB_OUT_FILE, "Sorry this command is not yet implemented.\n")
  35 #define TB_WF fprintf (TB_OUT_FILE, "Warning, this command failed.\n")
  36
  37
  38 /* Structures for handling Tree Browser's commands.  */
  39 #define DEFTBCODE(COMMAND, STRING, HELP)   COMMAND,
  40 enum TB_Comm_code {
  41 #include "tree-browser.def"
  42   TB_UNUSED_COMMAND
  43 };
  44 #undef DEFTBCODE
  45 typedef enum TB_Comm_code TB_CODE;
  46
  47 struct tb_command {
  48   const char *help_msg;
  49   const char *comm_text;
  50   size_t comm_len;
  51   TB_CODE comm_code;
  52 };
  53
  54 #define DEFTBCODE(code, str, help) { help, str, sizeof(str) - 1, code },
  55 static const struct tb_command tb_commands[] =
  56 {
  57 #include "tree-browser.def"
  58 };
  59 #undef DEFTBCODE
  60
  61 #define TB_COMMAND_LEN(N) (tb_commands[N].comm_len)
  62 #define TB_COMMAND_TEXT(N) (tb_commands[N].comm_text)
  63 #define TB_COMMAND_CODE(N) (tb_commands[N].comm_code)
  64 #define TB_COMMAND_HELP(N) (tb_commands[N].help_msg)
  65
  66
  67 /* Next structure is for parsing TREE_CODEs.  */
  68 struct tb_tree_code {
  69   enum tree_code code;
  70   const char *code_string;
  71   size_t code_string_len;
  72 };
  73
  74 #define DEFTREECODE(SYM, STRING, TYPE, NARGS) { SYM, STRING, sizeof (STRING) - 1 },
  75 static const struct tb_tree_code tb_tree_codes[] =
  76 {
  77 #include "tree.def"
  78 };
  79 #undef DEFTREECODE
  80
  81 #define TB_TREE_CODE(N) (tb_tree_codes[N].code)
  82 #define TB_TREE_CODE_TEXT(N) (tb_tree_codes[N].code_string)
  83 #define TB_TREE_CODE_LEN(N) (tb_tree_codes[N].code_string_len)
  84
  85
  86 /* Function declarations.  */
  87
  88 static long TB_getline (char **, long *, FILE *);
  89 static TB_CODE TB_get_command (char *);
  90 static enum tree_code TB_get_tree_code (char *);
  91 static tree find_node_with_code (tree *, int *, void *);
  92 static tree store_child_info (tree *, int *, void *);
  93 static void TB_update_up (tree);
  94 static tree TB_current_chain_node (tree);
  95 static tree TB_prev_expr (tree);
  96 static tree TB_next_expr (tree);
  97 static tree TB_up_expr (tree);
  98 static tree TB_first_in_bind (tree);
  99 static tree TB_last_in_bind (tree);
 100 static int  TB_parent_eq (const void *, const void *);
 101 static tree TB_history_prev (void);
 102
 103 /* FIXME: To be declared in a .h file.  */
 104 void browse_tree (tree);
 105
 106 /* Static variables.  */
 107 static htab_t TB_up_ht;
 108 static tree TB_history_stack = NULL_TREE;
 109 static int TB_verbose = 1;
 110
 111
 112 /* Entry point in the Tree Browser.  */
 113
 114 void
 115 browse_tree (tree begin)
 116 {
 117   tree head;
 118   TB_CODE tbc = TB_UNUSED_COMMAND;
 119   ssize_t rd;
 120   char *input = NULL;
 121   long input_size = 0;
 122
 123   fprintf (TB_OUT_FILE, "\nTree Browser\n");
 124
 125 #define TB_SET_HEAD(N) do {                                           \
 126   TB_history_stack = tree_cons (NULL_TREE, (N), TB_history_stack);    \
 127   head = N;                                                           \
 128   if (TB_verbose)                                                     \
 129     if (head)                                                         \
 130       {                                                               \
 131         print_generic_expr (TB_OUT_FILE, head, 0);                    \
 132         fprintf (TB_OUT_FILE, "\n");                                  \
 133       }                                                               \
 134 } while (0)
 135
 136   TB_SET_HEAD (begin);
 137
 138   /* Store in a hashtable information about previous and upper statements.  */
 139   {
 140     TB_up_ht = htab_create (1023, htab_hash_pointer, &TB_parent_eq, NULL);
 141     TB_update_up (head);
 142   }
 143
 144   while (24)
 145     {
 146       fprintf (TB_OUT_FILE, "TB> ");
 147       rd = TB_getline (&input, &input_size, TB_IN_FILE);
 148
 149       if (rd == -1)
 150         /* EOF.  */
 151         goto ret;
 152
 153       if (rd != 1)
 154         /* Get a new command.  Otherwise the user just pressed enter, and thus
 155            she expects the last command to be reexecuted.  */
 156         tbc = TB_get_command (input);
 157
 158       switch (tbc)
 159         {
 160         case TB_UPDATE_UP:
 161           TB_update_up (head);
 162           break;
 163
 164         case TB_MAX:
 165           if (head && (INTEGRAL_TYPE_P (head)
 166                        || TREE_CODE (head) == REAL_TYPE))
 167             TB_SET_HEAD (TYPE_MAX_VALUE (head));
 168           else
 169             TB_WF;
 170           break;
 171
 172         case TB_MIN:
 173           if (head && (INTEGRAL_TYPE_P (head)
 174                        || TREE_CODE (head) == REAL_TYPE))
 175             TB_SET_HEAD (TYPE_MIN_VALUE (head));
 176           else
 177             TB_WF;
 178           break;
 179
 180         case TB_ELT:
 181           if (head && TREE_CODE (head) == TREE_VEC)
 182             {
 183               /* This command takes another argument: the element number:
 184                  for example "elt 1".  */
 185               TB_NIY;
 186             }
 187           else if (head && TREE_CODE (head) == VECTOR_CST)
 188             {
 189               /* This command takes another argument: the element number:
 190                  for example "elt 1".  */
 191               TB_NIY;
 192             }
 193           else
 194             TB_WF;
 195           break;
 196
 197         case TB_VALUE:
 198           if (head && TREE_CODE (head) == TREE_LIST)
 199             TB_SET_HEAD (TREE_VALUE (head));
 200           else
 201             TB_WF;
 202           break;
 203
 204         case TB_PURPOSE:
 205           if (head && TREE_CODE (head) == TREE_LIST)
 206             TB_SET_HEAD (TREE_PURPOSE (head));
 207           else
 208             TB_WF;
 209           break;
 210
 211         case TB_IMAG:
 212           if (head && TREE_CODE (head) == COMPLEX_CST)
 213             TB_SET_HEAD (TREE_IMAGPART (head));
 214           else
 215             TB_WF;
 216           break;
 217
 218         case TB_REAL:
 219           if (head && TREE_CODE (head) == COMPLEX_CST)
 220             TB_SET_HEAD (TREE_REALPART (head));
 221           else
 222             TB_WF;
 223           break;
 224
 225         case TB_BLOCK:
 226           if (head && TREE_CODE (head) == BIND_EXPR)
 227             TB_SET_HEAD (TREE_OPERAND (head, 2));
 228           else
 229             TB_WF;
 230           break;
 231
 232         case TB_SUBBLOCKS:
 233           if (head && TREE_CODE (head) == BLOCK)
 234             TB_SET_HEAD (BLOCK_SUBBLOCKS (head));
 235           else
 236             TB_WF;
 237           break;
 238
 239         case TB_SUPERCONTEXT:
 240           if (head && TREE_CODE (head) == BLOCK)
 241             TB_SET_HEAD (BLOCK_SUPERCONTEXT (head));
 242           else
 243             TB_WF;
 244           break;
 245
 246         case TB_VARS:
 247           if (head && TREE_CODE (head) == BLOCK)
 248             TB_SET_HEAD (BLOCK_VARS (head));
 249           else if (head && TREE_CODE (head) == BIND_EXPR)
 250             TB_SET_HEAD (TREE_OPERAND (head, 0));
 251           else
 252             TB_WF;
 253           break;
 254
 255         case TB_REFERENCE_TO_THIS:
 256           if (head && TYPE_P (head))
 257             TB_SET_HEAD (TYPE_REFERENCE_TO (head));
 258           else
 259             TB_WF;
 260           break;
 261
 262         case TB_POINTER_TO_THIS:
 263           if (head && TYPE_P (head))
 264             TB_SET_HEAD (TYPE_POINTER_TO (head));
 265           else
 266             TB_WF;
 267           break;
 268
 269         case TB_BASETYPE:
 270           if (head && TREE_CODE (head) == OFFSET_TYPE)
 271             TB_SET_HEAD (TYPE_OFFSET_BASETYPE (head));
 272           else
 273             TB_WF;
 274           break;
 275
 276         case TB_ARG_TYPES:
 277           if (head && (TREE_CODE (head) == FUNCTION_TYPE
 278                        || TREE_CODE (head) == METHOD_TYPE))
 279             TB_SET_HEAD (TYPE_ARG_TYPES (head));
 280           else
 281             TB_WF;
 282           break;
 283
 284         case TB_METHOD_BASE_TYPE:
 285           if (head && (TREE_CODE (head) == FUNCTION_TYPE
 286                        || TREE_CODE (head) == METHOD_TYPE)
 287               && TYPE_METHOD_BASETYPE (head))
 288             TB_SET_HEAD (TYPE_METHOD_BASETYPE (head));
 289           else
 290             TB_WF;
 291           break;
 292
 293         case TB_FIELDS:
 294           if (head && (TREE_CODE (head) == RECORD_TYPE
 295                        || TREE_CODE (head) == UNION_TYPE
 296                        || TREE_CODE (head) == QUAL_UNION_TYPE))
 297             TB_SET_HEAD (TYPE_FIELDS (head));
 298           else
 299             TB_WF;
 300           break;
 301
 302         case TB_DOMAIN:
 303           if (head && TREE_CODE (head) == ARRAY_TYPE)
 304             TB_SET_HEAD (TYPE_DOMAIN (head));
 305           else
 306             TB_WF;
 307           break;
 308
 309         case TB_VALUES:
 310           if (head && TREE_CODE (head) == ENUMERAL_TYPE)
 311             TB_SET_HEAD (TYPE_VALUES (head));
 312           else
 313             TB_WF;
 314           break;
 315
 316         case TB_ARG_TYPE:
 317           if (head && TREE_CODE (head) == PARM_DECL)
 318             TB_SET_HEAD (DECL_ARG_TYPE (head));
 319           else
 320             TB_WF;
 321           break;
 322
 323         case TB_INITIAL:
 324           if (head && DECL_P (head))
 325             TB_SET_HEAD (DECL_INITIAL (head));
 326           else
 327             TB_WF;
 328           break;
 329
 330         case TB_RESULT:
 331           if (head && DECL_P (head))
 332             TB_SET_HEAD (DECL_RESULT_FLD (head));
 333           else
 334             TB_WF;
 335           break;
 336
 337         case TB_ARGUMENTS:
 338           if (head && DECL_P (head))
 339             TB_SET_HEAD (DECL_ARGUMENTS (head));
 340           else
 341             TB_WF;
 342           break;
 343
 344         case TB_ABSTRACT_ORIGIN:
 345           if (head && DECL_P (head))
 346             TB_SET_HEAD (DECL_ABSTRACT_ORIGIN (head));
 347           else if (head && TREE_CODE (head) == BLOCK)
 348             TB_SET_HEAD (BLOCK_ABSTRACT_ORIGIN (head));
 349           else
 350             TB_WF;
 351           break;
 352
 353         case TB_ATTRIBUTES:
 354           if (head && DECL_P (head))
 355             TB_SET_HEAD (DECL_ATTRIBUTES (head));
 356           else if (head && TYPE_P (head))
 357             TB_SET_HEAD (TYPE_ATTRIBUTES (head));
 358           else
 359             TB_WF;
 360           break;
 361
 362         case TB_CONTEXT:
 363           if (head && DECL_P (head))
 364             TB_SET_HEAD (DECL_CONTEXT (head));
 365           else if (head && TYPE_P (head)
 366                    && TYPE_CONTEXT (head))
 367             TB_SET_HEAD (TYPE_CONTEXT (head));
 368           else
 369             TB_WF;
 370           break;
 371
 372         case TB_OFFSET:
 373           if (head && TREE_CODE (head) == FIELD_DECL)
 374             TB_SET_HEAD (DECL_FIELD_OFFSET (head));
 375           else
 376             TB_WF;
 377           break;
 378
 379         case TB_BIT_OFFSET:
 380           if (head && TREE_CODE (head) == FIELD_DECL)
 381             TB_SET_HEAD (DECL_FIELD_BIT_OFFSET (head));
 382           else
 383             TB_WF;
 384           break;
 385
 386         case TB_UNIT_SIZE:
 387           if (head && DECL_P (head))
 388             TB_SET_HEAD (DECL_SIZE_UNIT (head));
 389           else if (head && TYPE_P (head))
 390             TB_SET_HEAD (TYPE_SIZE_UNIT (head));
 391           else
 392             TB_WF;
 393           break;
 394
 395         case TB_SIZE:
 396           if (head && DECL_P (head))
 397             TB_SET_HEAD (DECL_SIZE (head));
 398           else if (head && TYPE_P (head))
 399             TB_SET_HEAD (TYPE_SIZE (head));
 400           else
 401             TB_WF;
 402           break;
 403
 404         case TB_TYPE:
 405           if (head && TREE_TYPE (head))
 406             TB_SET_HEAD (TREE_TYPE (head));
 407           else
 408             TB_WF;
 409           break;
 410
 411         case TB_DECL_SAVED_TREE:
 412           if (head && TREE_CODE (head) == FUNCTION_DECL
 413               && DECL_SAVED_TREE (head))
 414             TB_SET_HEAD (DECL_SAVED_TREE (head));
 415           else
 416             TB_WF;
 417           break;
 418
 419         case TB_BODY:
 420           if (head && TREE_CODE (head) == BIND_EXPR)
 421             TB_SET_HEAD (TREE_OPERAND (head, 1));
 422           else
 423             TB_WF;
 424           break;
 425
 426         case TB_CHILD_0:
 427           if (head && EXPR_P (head) && TREE_OPERAND (head, 0))
 428             TB_SET_HEAD (TREE_OPERAND (head, 0));
 429           else
 430             TB_WF;
 431           break;
 432
 433         case TB_CHILD_1:
 434           if (head && EXPR_P (head) && TREE_OPERAND (head, 1))
 435             TB_SET_HEAD (TREE_OPERAND (head, 1));
 436           else
 437             TB_WF;
 438           break;
 439
 440         case TB_CHILD_2:
 441           if (head && EXPR_P (head) && TREE_OPERAND (head, 2))
 442             TB_SET_HEAD (TREE_OPERAND (head, 2));
 443           else
 444             TB_WF;
 445           break;
 446
 447         case TB_CHILD_3:
 448           if (head && EXPR_P (head) && TREE_OPERAND (head, 3))
 449             TB_SET_HEAD (TREE_OPERAND (head, 3));
 450           else
 451             TB_WF;
 452           break;
 453
 454         case TB_PRINT:
 455           if (head)
 456             debug_tree (head);
 457           else
 458             TB_WF;
 459           break;
 460
 461         case TB_PRETTY_PRINT:
 462           if (head)
 463             {
 464               print_generic_stmt (TB_OUT_FILE, head, 0);
 465               fprintf (TB_OUT_FILE, "\n");
 466             }
 467           else
 468             TB_WF;
 469           break;
 470
 471         case TB_SEARCH_NAME:
 472
 473           break;
 474
 475         case TB_SEARCH_CODE:
 476           {
 477             enum tree_code code;
 478             char *arg_text;
 479
 480             arg_text = strchr (input, ' ');
 481             if (arg_text == NULL)
 482               {
 483                 fprintf (TB_OUT_FILE, "First argument is missing.  This isn't a valid search command.  \n");
 484                 break;
 485               }
 486             code = TB_get_tree_code (arg_text + 1);
 487
 488             /* Search in the subtree a node with the given code.  */
 489             {
 490               tree res;
 491
 492               res = walk_tree (&head, find_node_with_code, &code, NULL);
 493               if (res == NULL_TREE)
 494                 {
 495                   fprintf (TB_OUT_FILE, "There's no node with this code (reachable via the walk_tree function from this node).\n");
 496                 }
 497               else
 498                 {
 499                   fprintf (TB_OUT_FILE, "Achoo!  I got this node in the tree.\n");
 500                   TB_SET_HEAD (res);
 501                 }
 502             }
 503             break;
 504           }
 505
 506 #define TB_MOVE_HEAD(FCT) do {       \
 507   if (head)                          \
 508     {                                \
 509       tree t;                        \
 510       t = FCT (head);                \
 511       if (t)                         \
 512         TB_SET_HEAD (t);             \
 513       else                           \
 514         TB_WF;                       \
 515     }                                \
 516   else                               \
 517     TB_WF;                           \
 518 } while (0)
 519
 520         case TB_FIRST:
 521           TB_MOVE_HEAD (TB_first_in_bind);
 522           break;
 523
 524         case TB_LAST:
 525           TB_MOVE_HEAD (TB_last_in_bind);
 526           break;
 527
 528         case TB_UP:
 529           TB_MOVE_HEAD (TB_up_expr);
 530           break;
 531
 532         case TB_PREV:
 533           TB_MOVE_HEAD (TB_prev_expr);
 534           break;
 535
 536         case TB_NEXT:
 537           TB_MOVE_HEAD (TB_next_expr);
 538           break;
 539
 540         case TB_HPREV:
 541           /* This command is a little bit special, since it deals with history
 542              stack.  For this reason it should keep the "head = ..." statement
 543              and not use TB_MOVE_HEAD.  */
 544           if (head)
 545             {
 546               tree t;
 547               t = TB_history_prev ();
 548               if (t)
 549                 {
 550                   head = t;
 551                   if (TB_verbose)
 552                     {
 553                       print_generic_expr (TB_OUT_FILE, head, 0);
 554                       fprintf (TB_OUT_FILE, "\n");
 555                     }
 556                 }
 557               else
 558                 TB_WF;
 559             }
 560           else
 561             TB_WF;
 562           break;
 563
 564         case TB_CHAIN:
 565           /* Don't go further if it's the last node in this chain.  */
 566           if (head && TREE_CODE (head) == BLOCK)
 567             TB_SET_HEAD (BLOCK_CHAIN (head));
 568           else if (head && TREE_CHAIN (head))
 569             TB_SET_HEAD (TREE_CHAIN (head));
 570           else
 571             TB_WF;
 572           break;
 573
 574         case TB_FUN:
 575           /* Go up to the current function declaration.  */
 576           TB_SET_HEAD (current_function_decl);
 577           fprintf (TB_OUT_FILE, "Current function declaration.\n");
 578           break;
 579
 580         case TB_HELP:
 581           /* Display a help message.  */
 582           {
 583             int i;
 584             fprintf (TB_OUT_FILE, "Possible commands are:\n\n");
 585             for (i = 0; i < TB_UNUSED_COMMAND; i++)
 586               {
 587                 fprintf (TB_OUT_FILE, "%20s  -  %s\n", TB_COMMAND_TEXT (i), TB_COMMAND_HELP (i));
 588               }
 589           }
 590           break;
 591
 592         case TB_VERBOSE:
 593           if (TB_verbose == 0)
 594             {
 595               TB_verbose = 1;
 596               fprintf (TB_OUT_FILE, "Verbose on.\n");
 597             }
 598           else
 599             {
 600               TB_verbose = 0;
 601               fprintf (TB_OUT_FILE, "Verbose off.\n");
 602             }
 603           break;
 604
 605         case TB_EXIT:
 606         case TB_QUIT:
 607           /* Just exit from this function.  */
 608           goto ret;
 609
 610         default:
 611           TB_NIY;
 612         }
 613     }
 614
 615  ret:;
 616   htab_delete (TB_up_ht);
 617   return;
 618 }
 619
 620
 621 /* Search the first node in this BIND_EXPR.  */
 622
 623 static tree
 624 TB_first_in_bind (tree node)
 625 {
 626   tree t;
 627
 628   if (node == NULL_TREE)
 629     return NULL_TREE;
 630
 631   while ((t = TB_prev_expr (node)))
 632     node = t;
 633
 634   return node;
 635 }
 636
 637 /* Search the last node in this BIND_EXPR.  */
 638
 639 static tree
 640 TB_last_in_bind (tree node)
 641 {
 642   tree t;
 643
 644   if (node == NULL_TREE)
 645     return NULL_TREE;
 646
 647   while ((t = TB_next_expr (node)))
 648     node = t;
 649
 650   return node;
 651 }
 652
 653 /* Search the parent expression for this node.  */
 654
 655 static tree
 656 TB_up_expr (tree node)
 657 {
 658   tree res;
 659   if (node == NULL_TREE)
 660     return NULL_TREE;
 661
 662   res = (tree) htab_find (TB_up_ht, node);
 663   return res;
 664 }
 665
 666 /* Search the previous expression in this BIND_EXPR.  */
 667
 668 static tree
 669 TB_prev_expr (tree node)
 670 {
 671   node = TB_current_chain_node (node);
 672
 673   if (node == NULL_TREE)
 674     return NULL_TREE;
 675
 676   node = TB_up_expr (node);
 677   if (node && TREE_CODE (node) == COMPOUND_EXPR)
 678     return node;
 679   else
 680     return NULL_TREE;
 681 }
 682
 683 /* Search the next expression in this BIND_EXPR.  */
 684
 685 static tree
 686 TB_next_expr (tree node)
 687 {
 688   node = TB_current_chain_node (node);
 689
 690   if (node == NULL_TREE)
 691     return NULL_TREE;
 692
 693   node = TREE_OPERAND (node, 1);
 694   return node;
 695 }
 696
 697 static tree
 698 TB_current_chain_node (tree node)
 699 {
 700   if (node == NULL_TREE)
 701     return NULL_TREE;
 702
 703   if (TREE_CODE (node) == COMPOUND_EXPR)
 704     return node;
 705
 706   node = TB_up_expr (node);
 707   if (node)
 708     {
 709       if (TREE_CODE (node) == COMPOUND_EXPR)
 710         return node;
 711
 712       node = TB_up_expr (node);
 713       if (TREE_CODE (node) == COMPOUND_EXPR)
 714         return node;
 715     }
 716
 717   return NULL_TREE;
 718 }
 719
 720 /* For each node store in its children nodes that the current node is their
 721    parent.  This function is used by walk_tree.  */
 722
 723 static tree
 724 store_child_info (tree *tp, int *walk_subtrees ATTRIBUTE_UNUSED,
 725                   void *data ATTRIBUTE_UNUSED)
 726 {
 727   tree node;
 728   void **slot;
 729
 730   node = *tp;
 731
 732   /* 'node' is the parent of 'TREE_OPERAND (node, *)'.  */
 733   if (EXPRESSION_CLASS_P (node))
 734     {
 735
 736 #define STORE_CHILD(N) do {                                                \
 737   tree op = TREE_OPERAND (node, N);                                        \
 738   slot = htab_find_slot (TB_up_ht, op, INSERT);                               \
 739   *slot = (void *) node;                                                   \
 740 } while (0)
 741
 742       switch (TREE_CODE_LENGTH (TREE_CODE (node)))
 743         {
 744         case 4:
 745           STORE_CHILD (0);
 746           STORE_CHILD (1);
 747           STORE_CHILD (2);
 748           STORE_CHILD (3);
 749           break;
 750
 751         case 3:
 752           STORE_CHILD (0);
 753           STORE_CHILD (1);
 754           STORE_CHILD (2);
 755           break;
 756
 757         case 2:
 758           STORE_CHILD (0);
 759           STORE_CHILD (1);
 760           break;
 761
 762         case 1:
 763           STORE_CHILD (0);
 764           break;
 765
 766         case 0:
 767         default:
 768           /* No children: nothing to do.  */
 769           break;
 770         }
 771 #undef STORE_CHILD
 772     }
 773
 774   /* Never stop walk_tree.  */
 775   return NULL_TREE;
 776 }
 777
 778 /* Function used in TB_up_ht.  */
 779
 780 static int
 781 TB_parent_eq (const void *p1, const void *p2)
 782 {
 783   tree node, parent;
 784   node = (tree) p2;
 785   parent = (tree) p1;
 786
 787   if (p1 == NULL || p2 == NULL)
 788     return 0;
 789
 790   if (EXPRESSION_CLASS_P (parent))
 791     {
 792
 793 #define TEST_CHILD(N) do {               \
 794   if (node == TREE_OPERAND (parent, N))  \
 795     return 1;                            \
 796 } while (0)
 797
 798     switch (TREE_CODE_LENGTH (TREE_CODE (parent)))
 799       {
 800       case 4:
 801         TEST_CHILD (0);
 802         TEST_CHILD (1);
 803         TEST_CHILD (2);
 804         TEST_CHILD (3);
 805         break;
 806
 807       case 3:
 808         TEST_CHILD (0);
 809         TEST_CHILD (1);
 810         TEST_CHILD (2);
 811         break;
 812
 813       case 2:
 814         TEST_CHILD (0);
 815         TEST_CHILD (1);
 816         break;
 817
 818       case 1:
 819         TEST_CHILD (0);
 820         break;
 821
 822       case 0:
 823       default:
 824         /* No children: nothing to do.  */
 825         break;
 826       }
 827 #undef TEST_CHILD
 828     }
 829
 830   return 0;
 831 }
 832
 833 /* Update information about upper expressions in the hash table.  */
 834
 835 static void
 836 TB_update_up (tree node)
 837 {
 838   while (node)
 839     {
 840       walk_tree (&node, store_child_info, NULL, NULL);
 841
 842       /* Walk function's body.  */
 843       if (TREE_CODE (node) == FUNCTION_DECL)
 844         if (DECL_SAVED_TREE (node))
 845           walk_tree (&DECL_SAVED_TREE (node), store_child_info, NULL, NULL);
 846
 847       /* Walk rest of the chain.  */
 848       node = TREE_CHAIN (node);
 849     }
 850   fprintf (TB_OUT_FILE, "Up/prev expressions updated.\n");
 851 }
 852
 853 /* Parse the input string for determining the command the user asked for.  */
 854
 855 static TB_CODE
 856 TB_get_command (char *input)
 857 {
 858   unsigned int mn, size_tok;
 859   int comp;
 860   char *space;
 861
 862   space = strchr (input, ' ');
 863   if (space != NULL)
 864     size_tok = strlen (input) - strlen (space);
 865   else
 866     size_tok = strlen (input) - 1;
 867
 868   for (mn = 0; mn < TB_UNUSED_COMMAND; mn++)
 869     {
 870       if (size_tok != TB_COMMAND_LEN (mn))
 871         continue;
 872
 873       comp = memcmp (input, TB_COMMAND_TEXT (mn), TB_COMMAND_LEN (mn));
 874       if (comp == 0)
 875         /* Here we just determined the command.  If this command takes
 876            an argument, then the argument is determined later.  */
 877         return TB_COMMAND_CODE (mn);
 878     }
 879
 880   /* Not a valid command.  */
 881   return TB_UNUSED_COMMAND;
 882 }
 883
 884 /* Parse the input string for determining the tree code.  */
 885
 886 static enum tree_code
 887 TB_get_tree_code (char *input)
 888 {
 889   unsigned int mn, size_tok;
 890   int comp;
 891   char *space;
 892
 893   space = strchr (input, ' ');
 894   if (space != NULL)
 895     size_tok = strlen (input) - strlen (space);
 896   else
 897     size_tok = strlen (input) - 1;
 898
 899   for (mn = 0; mn < LAST_AND_UNUSED_TREE_CODE; mn++)
 900     {
 901       if (size_tok != TB_TREE_CODE_LEN (mn))
 902         continue;
 903
 904       comp = memcmp (input, TB_TREE_CODE_TEXT (mn), TB_TREE_CODE_LEN (mn));
 905       if (comp == 0)
 906         {
 907           fprintf (TB_OUT_FILE, "%s\n", TB_TREE_CODE_TEXT (mn));
 908           return TB_TREE_CODE (mn);
 909         }
 910     }
 911
 912   /* This isn't a valid code.  */
 913   return LAST_AND_UNUSED_TREE_CODE;
 914 }
 915
 916 /* Find a node with a given code.  This function is used as an argument to
 917    walk_tree.  */
 918
 919 static tree
 920 find_node_with_code (tree *tp, int *walk_subtrees ATTRIBUTE_UNUSED,
 921                      void *data)
 922 {
 923   enum tree_code *code;
 924   code = (enum tree_code *) data;
 925   if (*code == TREE_CODE (*tp))
 926     return *tp;
 927
 928   return NULL_TREE;
 929 }
 930
 931 /* Returns a pointer to the last visited node.  */
 932
 933 static tree
 934 TB_history_prev (void)
 935 {
 936   if (TB_history_stack)
 937     {
 938       TB_history_stack = TREE_CHAIN (TB_history_stack);
 939       if (TB_history_stack)
 940         return TREE_VALUE (TB_history_stack);
 941     }
 942   return NULL_TREE;
 943 }
 944
 945 /* Read up to (and including) a '\n' from STREAM into *LINEPTR
 946    (and null-terminate it). *LINEPTR is a pointer returned from malloc
 947    (or NULL), pointing to *N characters of space.  It is realloc'd as
 948    necessary.  Returns the number of characters read (not including the
 949    null terminator), or -1 on error or EOF.
 950    This function comes from sed (and is supposed to be a portable version
 951    of getline).  */
 952
 953 static long
 954 TB_getline (char **lineptr, long *n, FILE *stream)
 955 {
 956   char *line, *p;
 957   long size, copy;
 958
 959   if (lineptr == NULL || n == NULL)
 960     {
 961       errno = EINVAL;
 962       return -1;
 963     }
 964
 965   if (ferror (stream))
 966     return -1;
 967
 968   /* Make sure we have a line buffer to start with.  */
 969   if (*lineptr == NULL || *n < 2) /* !seen and no buf yet need 2 chars.  */
 970     {
 971 #ifndef MAX_CANON
 972 #define MAX_CANON       256
 973 #endif
 974       line = (char *) xrealloc (*lineptr, MAX_CANON);
 975       if (line == NULL)
 976         return -1;
 977       *lineptr = line;
 978       *n = MAX_CANON;
 979     }
 980
 981   line = *lineptr;
 982   size = *n;
 983
 984   copy = size;
 985   p = line;
 986
 987   while (1)
 988     {
 989       long len;
 990
 991       while (--copy > 0)
 992         {
 993           register int c = getc (stream);
 994           if (c == EOF)
 995             goto lose;
 996           else if ((*p++ = c) == '\n')
 997             goto win;
 998         }
 999
1000       /* Need to enlarge the line buffer.  */
1001       len = p - line;
1002       size *= 2;
1003       line = (char *) xrealloc (line, size);
1004       if (line == NULL)
1005         goto lose;
1006       *lineptr = line;
1007       *n = size;
1008       p = line + len;
1009       copy = size - len;
1010     }
1011
1012  lose:
1013   if (p == *lineptr)
1014     return -1;
1015
1016   /* Return a partial line since we got an error in the middle.  */
1017  win:
1018 #if defined(WIN32) || defined(_WIN32) || defined(__CYGWIN__) || defined(MSDOS)
1019   if (p - 2 >= *lineptr && p[-2] == '\r')
1020     p[-2] = p[-1], --p;
1021 #endif
1022   *p = '\0';
1023   return p - *lineptr;
1024 }