gcc/tree-browser.c

   1 /* Tree browser.
   2    Copyright (C) 2002-2013 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 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 #include "config.h"
  22 #include "system.h"
  23 #include "coretypes.h"
  24 #include "hash-table.h"
  25 #include "tree.h"
  26 #include "tree-pretty-print.h"
  27 #include "print-tree.h"
  28
  29 #define TB_OUT_FILE stdout
  30 #define TB_IN_FILE stdin
  31 #define TB_NIY fprintf (TB_OUT_FILE, "Sorry this command is not yet implemented.\n")
  32 #define TB_WF fprintf (TB_OUT_FILE, "Warning, this command failed.\n")
  33
  34 /* Structures for handling Tree Browser's commands.  */
  35 #define DEFTBCODE(COMMAND, STRING, HELP)   COMMAND,
  36 enum TB_Comm_code {
  37 #include "tree-browser.def"
  38   TB_UNUSED_COMMAND
  39 };
  40 #undef DEFTBCODE
  41 typedef enum TB_Comm_code TB_CODE;
  42
  43 struct tb_command {
  44   const char *help_msg;
  45   const char *comm_text;
  46   size_t comm_len;
  47   TB_CODE comm_code;
  48 };
  49
  50 #define DEFTBCODE(code, str, help) { help, str, sizeof (str) - 1, code },
  51 static const struct tb_command tb_commands[] =
  52 {
  53 #include "tree-browser.def"
  54 };
  55 #undef DEFTBCODE
  56
  57 #define TB_COMMAND_LEN(N) (tb_commands[N].comm_len)
  58 #define TB_COMMAND_TEXT(N) (tb_commands[N].comm_text)
  59 #define TB_COMMAND_CODE(N) (tb_commands[N].comm_code)
  60 #define TB_COMMAND_HELP(N) (tb_commands[N].help_msg)
  61
  62
  63 /* Next structure is for parsing TREE_CODEs.  */
  64 struct tb_tree_code {
  65   enum tree_code code;
  66   const char *code_string;
  67   size_t code_string_len;
  68 };
  69
  70 #define DEFTREECODE(SYM, STRING, TYPE, NARGS) { SYM, STRING, sizeof (STRING) - 1 },
  71 #define END_OF_BASE_TREE_CODES \
  72   { LAST_AND_UNUSED_TREE_CODE, "@dummy", sizeof ("@dummy") - 1 },
  73 static const struct tb_tree_code tb_tree_codes[] =
  74 {
  75 #include "all-tree.def"
  76 };
  77 #undef DEFTREECODE
  78 #undef END_OF_BASE_TREE_CODES
  79
  80 #define TB_TREE_CODE(N) (tb_tree_codes[N].code)
  81 #define TB_TREE_CODE_TEXT(N) (tb_tree_codes[N].code_string)
  82 #define TB_TREE_CODE_LEN(N) (tb_tree_codes[N].code_string_len)
  83
  84
  85 /* Function declarations.  */
  86
  87 static long TB_getline (char **, long *, FILE *);
  88 static TB_CODE TB_get_command (char *);
  89 static enum tree_code TB_get_tree_code (char *);
  90 static tree find_node_with_code (tree *, int *, void *);
  91 static tree store_child_info (tree *, int *, void *);
  92 static void TB_update_up (tree);
  93 static tree TB_current_chain_node (tree);
  94 static tree TB_prev_expr (tree);
  95 static tree TB_next_expr (tree);
  96 static tree TB_up_expr (tree);
  97 static tree TB_first_in_bind (tree);
  98 static tree TB_last_in_bind (tree);
  99 static tree TB_history_prev (void);
 100
 101 /* FIXME: To be declared in a .h file.  */
 102 void browse_tree (tree);
 103
 104 /* Hashtable helpers.  */
 105 struct tree_upper_hasher : typed_noop_remove <tree_node>
 106 {
 107   typedef tree_node value_type;
 108   typedef tree_node compare_type;
 109   static inline hashval_t hash (const value_type *);
 110   static inline bool equal (const value_type *, const compare_type *);
 111 };
 112
 113 inline hashval_t
 114 tree_upper_hasher::hash (const value_type *v)
 115 {
 116   return pointer_hash <value_type>::hash (v);
 117 }
 118
 119 inline bool
 120 tree_upper_hasher::equal (const value_type *parent, const compare_type *node)
 121 {
 122   if (parent == NULL || node == NULL)
 123     return 0;
 124
 125   if (EXPR_P (parent))
 126     {
 127       int n = TREE_OPERAND_LENGTH (parent);
 128       int i;
 129       for (i = 0; i < n; i++)
 130         if (node == TREE_OPERAND (parent, i))
 131           return true;
 132     }
 133   return false;
 134 }
 135
 136 /* Static variables.  */
 137 static hash_table <tree_upper_hasher> TB_up_ht;
 138 static vec<tree, va_gc> *TB_history_stack;
 139 static int TB_verbose = 1;
 140
 141
 142 /* Entry point in the Tree Browser.  */
 143
 144 void
 145 browse_tree (tree begin)
 146 {
 147   tree head;
 148   TB_CODE tbc = TB_UNUSED_COMMAND;
 149   ssize_t rd;
 150   char *input = NULL;
 151   long input_size = 0;
 152
 153   fprintf (TB_OUT_FILE, "\nTree Browser\n");
 154
 155 #define TB_SET_HEAD(N) do {                                           \
 156   vec_safe_push (TB_history_stack, N);                                \
 157   head = N;                                                           \
 158   if (TB_verbose)                                                     \
 159     if (head)                                                         \
 160       {                                                               \
 161         print_generic_expr (TB_OUT_FILE, head, 0);                    \
 162         fprintf (TB_OUT_FILE, "\n");                                  \
 163       }                                                               \
 164 } while (0)
 165
 166   TB_SET_HEAD (begin);
 167
 168   /* Store in a hashtable information about previous and upper statements.  */
 169   {
 170     TB_up_ht.create (1023);
 171     TB_update_up (head);
 172   }
 173
 174   while (24)
 175     {
 176       fprintf (TB_OUT_FILE, "TB> ");
 177       rd = TB_getline (&input, &input_size, TB_IN_FILE);
 178
 179       if (rd == -1)
 180         /* EOF.  */
 181         goto ret;
 182
 183       if (rd != 1)
 184         /* Get a new command.  Otherwise the user just pressed enter, and thus
 185            she expects the last command to be reexecuted.  */
 186         tbc = TB_get_command (input);
 187
 188       switch (tbc)
 189         {
 190         case TB_UPDATE_UP:
 191           TB_update_up (head);
 192           break;
 193
 194         case TB_MAX:
 195           if (head && (INTEGRAL_TYPE_P (head)
 196                        || TREE_CODE (head) == REAL_TYPE
 197                        || TREE_CODE (head) == FIXED_POINT_TYPE))
 198             TB_SET_HEAD (TYPE_MAX_VALUE (head));
 199           else
 200             TB_WF;
 201           break;
 202
 203         case TB_MIN:
 204           if (head && (INTEGRAL_TYPE_P (head)
 205                        || TREE_CODE (head) == REAL_TYPE
 206                        || TREE_CODE (head) == FIXED_POINT_TYPE))
 207             TB_SET_HEAD (TYPE_MIN_VALUE (head));
 208           else
 209             TB_WF;
 210           break;
 211
 212         case TB_ELT:
 213           if (head && TREE_CODE (head) == TREE_VEC)
 214             {
 215               /* This command takes another argument: the element number:
 216                  for example "elt 1".  */
 217               TB_NIY;
 218             }
 219           else if (head && TREE_CODE (head) == VECTOR_CST)
 220             {
 221               /* This command takes another argument: the element number:
 222                  for example "elt 1".  */
 223               TB_NIY;
 224             }
 225           else
 226             TB_WF;
 227           break;
 228
 229         case TB_VALUE:
 230           if (head && TREE_CODE (head) == TREE_LIST)
 231             TB_SET_HEAD (TREE_VALUE (head));
 232           else
 233             TB_WF;
 234           break;
 235
 236         case TB_PURPOSE:
 237           if (head && TREE_CODE (head) == TREE_LIST)
 238             TB_SET_HEAD (TREE_PURPOSE (head));
 239           else
 240             TB_WF;
 241           break;
 242
 243         case TB_IMAG:
 244           if (head && TREE_CODE (head) == COMPLEX_CST)
 245             TB_SET_HEAD (TREE_IMAGPART (head));
 246           else
 247             TB_WF;
 248           break;
 249
 250         case TB_REAL:
 251           if (head && TREE_CODE (head) == COMPLEX_CST)
 252             TB_SET_HEAD (TREE_REALPART (head));
 253           else
 254             TB_WF;
 255           break;
 256
 257         case TB_BLOCK:
 258           if (head && TREE_CODE (head) == BIND_EXPR)
 259             TB_SET_HEAD (TREE_OPERAND (head, 2));
 260           else
 261             TB_WF;
 262           break;
 263
 264         case TB_SUBBLOCKS:
 265           if (head && TREE_CODE (head) == BLOCK)
 266             TB_SET_HEAD (BLOCK_SUBBLOCKS (head));
 267           else
 268             TB_WF;
 269           break;
 270
 271         case TB_SUPERCONTEXT:
 272           if (head && TREE_CODE (head) == BLOCK)
 273             TB_SET_HEAD (BLOCK_SUPERCONTEXT (head));
 274           else
 275             TB_WF;
 276           break;
 277
 278         case TB_VARS:
 279           if (head && TREE_CODE (head) == BLOCK)
 280             TB_SET_HEAD (BLOCK_VARS (head));
 281           else if (head && TREE_CODE (head) == BIND_EXPR)
 282             TB_SET_HEAD (TREE_OPERAND (head, 0));
 283           else
 284             TB_WF;
 285           break;
 286
 287         case TB_REFERENCE_TO_THIS:
 288           if (head && TYPE_P (head))
 289             TB_SET_HEAD (TYPE_REFERENCE_TO (head));
 290           else
 291             TB_WF;
 292           break;
 293
 294         case TB_POINTER_TO_THIS:
 295           if (head && TYPE_P (head))
 296             TB_SET_HEAD (TYPE_POINTER_TO (head));
 297           else
 298             TB_WF;
 299           break;
 300
 301         case TB_BASETYPE:
 302           if (head && TREE_CODE (head) == OFFSET_TYPE)
 303             TB_SET_HEAD (TYPE_OFFSET_BASETYPE (head));
 304           else
 305             TB_WF;
 306           break;
 307
 308         case TB_ARG_TYPES:
 309           if (head && (TREE_CODE (head) == FUNCTION_TYPE
 310                        || TREE_CODE (head) == METHOD_TYPE))
 311             TB_SET_HEAD (TYPE_ARG_TYPES (head));
 312           else
 313             TB_WF;
 314           break;
 315
 316         case TB_METHOD_BASE_TYPE:
 317           if (head && (TREE_CODE (head) == FUNCTION_TYPE
 318                        || TREE_CODE (head) == METHOD_TYPE)
 319               && TYPE_METHOD_BASETYPE (head))
 320             TB_SET_HEAD (TYPE_METHOD_BASETYPE (head));
 321           else
 322             TB_WF;
 323           break;
 324
 325         case TB_FIELDS:
 326           if (head && (TREE_CODE (head) == RECORD_TYPE
 327                        || TREE_CODE (head) == UNION_TYPE
 328                        || TREE_CODE (head) == QUAL_UNION_TYPE))
 329             TB_SET_HEAD (TYPE_FIELDS (head));
 330           else
 331             TB_WF;
 332           break;
 333
 334         case TB_DOMAIN:
 335           if (head && TREE_CODE (head) == ARRAY_TYPE)
 336             TB_SET_HEAD (TYPE_DOMAIN (head));
 337           else
 338             TB_WF;
 339           break;
 340
 341         case TB_VALUES:
 342           if (head && TREE_CODE (head) == ENUMERAL_TYPE)
 343             TB_SET_HEAD (TYPE_VALUES (head));
 344           else
 345             TB_WF;
 346           break;
 347
 348         case TB_ARG_TYPE:
 349           if (head && TREE_CODE (head) == PARM_DECL)
 350             TB_SET_HEAD (DECL_ARG_TYPE (head));
 351           else
 352             TB_WF;
 353           break;
 354
 355         case TB_INITIAL:
 356           if (head && DECL_P (head))
 357             TB_SET_HEAD (DECL_INITIAL (head));
 358           else
 359             TB_WF;
 360           break;
 361
 362         case TB_RESULT:
 363           if (head && DECL_P (head))
 364             TB_SET_HEAD (DECL_RESULT_FLD (head));
 365           else
 366             TB_WF;
 367           break;
 368
 369         case TB_ARGUMENTS:
 370           if (head && DECL_P (head))
 371             TB_SET_HEAD (DECL_ARGUMENTS (head));
 372           else
 373             TB_WF;
 374           break;
 375
 376         case TB_ABSTRACT_ORIGIN:
 377           if (head && DECL_P (head))
 378             TB_SET_HEAD (DECL_ABSTRACT_ORIGIN (head));
 379           else if (head && TREE_CODE (head) == BLOCK)
 380             TB_SET_HEAD (BLOCK_ABSTRACT_ORIGIN (head));
 381           else
 382             TB_WF;
 383           break;
 384
 385         case TB_ATTRIBUTES:
 386           if (head && DECL_P (head))
 387             TB_SET_HEAD (DECL_ATTRIBUTES (head));
 388           else if (head && TYPE_P (head))
 389             TB_SET_HEAD (TYPE_ATTRIBUTES (head));
 390           else
 391             TB_WF;
 392           break;
 393
 394         case TB_CONTEXT:
 395           if (head && DECL_P (head))
 396             TB_SET_HEAD (DECL_CONTEXT (head));
 397           else if (head && TYPE_P (head)
 398                    && TYPE_CONTEXT (head))
 399             TB_SET_HEAD (TYPE_CONTEXT (head));
 400           else
 401             TB_WF;
 402           break;
 403
 404         case TB_OFFSET:
 405           if (head && TREE_CODE (head) == FIELD_DECL)
 406             TB_SET_HEAD (DECL_FIELD_OFFSET (head));
 407           else
 408             TB_WF;
 409           break;
 410
 411         case TB_BIT_OFFSET:
 412           if (head && TREE_CODE (head) == FIELD_DECL)
 413             TB_SET_HEAD (DECL_FIELD_BIT_OFFSET (head));
 414           else
 415             TB_WF;
 416           break;
 417
 418         case TB_UNIT_SIZE:
 419           if (head && DECL_P (head))
 420             TB_SET_HEAD (DECL_SIZE_UNIT (head));
 421           else if (head && TYPE_P (head))
 422             TB_SET_HEAD (TYPE_SIZE_UNIT (head));
 423           else
 424             TB_WF;
 425           break;
 426
 427         case TB_SIZE:
 428           if (head && DECL_P (head))
 429             TB_SET_HEAD (DECL_SIZE (head));
 430           else if (head && TYPE_P (head))
 431             TB_SET_HEAD (TYPE_SIZE (head));
 432           else
 433             TB_WF;
 434           break;
 435
 436         case TB_TYPE:
 437           if (head && TREE_TYPE (head))
 438             TB_SET_HEAD (TREE_TYPE (head));
 439           else
 440             TB_WF;
 441           break;
 442
 443         case TB_DECL_SAVED_TREE:
 444           if (head && TREE_CODE (head) == FUNCTION_DECL
 445               && DECL_SAVED_TREE (head))
 446             TB_SET_HEAD (DECL_SAVED_TREE (head));
 447           else
 448             TB_WF;
 449           break;
 450
 451         case TB_BODY:
 452           if (head && TREE_CODE (head) == BIND_EXPR)
 453             TB_SET_HEAD (TREE_OPERAND (head, 1));
 454           else
 455             TB_WF;
 456           break;
 457
 458         case TB_CHILD_0:
 459           if (head && EXPR_P (head) && TREE_OPERAND (head, 0))
 460             TB_SET_HEAD (TREE_OPERAND (head, 0));
 461           else
 462             TB_WF;
 463           break;
 464
 465         case TB_CHILD_1:
 466           if (head && EXPR_P (head) && TREE_OPERAND (head, 1))
 467             TB_SET_HEAD (TREE_OPERAND (head, 1));
 468           else
 469             TB_WF;
 470           break;
 471
 472         case TB_CHILD_2:
 473           if (head && EXPR_P (head) && TREE_OPERAND (head, 2))
 474             TB_SET_HEAD (TREE_OPERAND (head, 2));
 475           else
 476             TB_WF;
 477           break;
 478
 479         case TB_CHILD_3:
 480           if (head && EXPR_P (head) && TREE_OPERAND (head, 3))
 481             TB_SET_HEAD (TREE_OPERAND (head, 3));
 482           else
 483             TB_WF;
 484           break;
 485
 486         case TB_PRINT:
 487           if (head)
 488             debug_tree (head);
 489           else
 490             TB_WF;
 491           break;
 492
 493         case TB_PRETTY_PRINT:
 494           if (head)
 495             {
 496               print_generic_stmt (TB_OUT_FILE, head, 0);
 497               fprintf (TB_OUT_FILE, "\n");
 498             }
 499           else
 500             TB_WF;
 501           break;
 502
 503         case TB_SEARCH_NAME:
 504
 505           break;
 506
 507         case TB_SEARCH_CODE:
 508           {
 509             enum tree_code code;
 510             char *arg_text;
 511
 512             arg_text = strchr (input, ' ');
 513             if (arg_text == NULL)
 514               {
 515                 fprintf (TB_OUT_FILE, "First argument is missing.  This isn't a valid search command.  \n");
 516                 break;
 517               }
 518             code = TB_get_tree_code (arg_text + 1);
 519
 520             /* Search in the subtree a node with the given code.  */
 521             {
 522               tree res;
 523
 524               res = walk_tree (&head, find_node_with_code, &code, NULL);
 525               if (res == NULL_TREE)
 526                 {
 527                   fprintf (TB_OUT_FILE, "There's no node with this code (reachable via the walk_tree function from this node).\n");
 528                 }
 529               else
 530                 {
 531                   fprintf (TB_OUT_FILE, "Achoo!  I got this node in the tree.\n");
 532                   TB_SET_HEAD (res);
 533                 }
 534             }
 535             break;
 536           }
 537
 538 #define TB_MOVE_HEAD(FCT) do {       \
 539   if (head)                          \
 540     {                                \
 541       tree t;                        \
 542       t = FCT (head);                \
 543       if (t)                         \
 544         TB_SET_HEAD (t);             \
 545       else                           \
 546         TB_WF;                       \
 547     }                                \
 548   else                               \
 549     TB_WF;                           \
 550 } while (0)
 551
 552         case TB_FIRST:
 553           TB_MOVE_HEAD (TB_first_in_bind);
 554           break;
 555
 556         case TB_LAST:
 557           TB_MOVE_HEAD (TB_last_in_bind);
 558           break;
 559
 560         case TB_UP:
 561           TB_MOVE_HEAD (TB_up_expr);
 562           break;
 563
 564         case TB_PREV:
 565           TB_MOVE_HEAD (TB_prev_expr);
 566           break;
 567
 568         case TB_NEXT:
 569           TB_MOVE_HEAD (TB_next_expr);
 570           break;
 571
 572         case TB_HPREV:
 573           /* This command is a little bit special, since it deals with history
 574              stack.  For this reason it should keep the "head = ..." statement
 575              and not use TB_MOVE_HEAD.  */
 576           if (head)
 577             {
 578               tree t;
 579               t = TB_history_prev ();
 580               if (t)
 581                 {
 582                   head = t;
 583                   if (TB_verbose)
 584                     {
 585                       print_generic_expr (TB_OUT_FILE, head, 0);
 586                       fprintf (TB_OUT_FILE, "\n");
 587                     }
 588                 }
 589               else
 590                 TB_WF;
 591             }
 592           else
 593             TB_WF;
 594           break;
 595
 596         case TB_CHAIN:
 597           /* Don't go further if it's the last node in this chain.  */
 598           if (head && TREE_CODE (head) == BLOCK)
 599             TB_SET_HEAD (BLOCK_CHAIN (head));
 600           else if (head && TREE_CHAIN (head))
 601             TB_SET_HEAD (TREE_CHAIN (head));
 602           else
 603             TB_WF;
 604           break;
 605
 606         case TB_FUN:
 607           /* Go up to the current function declaration.  */
 608           TB_SET_HEAD (current_function_decl);
 609           fprintf (TB_OUT_FILE, "Current function declaration.\n");
 610           break;
 611
 612         case TB_HELP:
 613           /* Display a help message.  */
 614           {
 615             int i;
 616             fprintf (TB_OUT_FILE, "Possible commands are:\n\n");
 617             for (i = 0; i < TB_UNUSED_COMMAND; i++)
 618               {
 619                 fprintf (TB_OUT_FILE, "%20s  -  %s\n", TB_COMMAND_TEXT (i), TB_COMMAND_HELP (i));
 620               }
 621           }
 622           break;
 623
 624         case TB_VERBOSE:
 625           if (TB_verbose == 0)
 626             {
 627               TB_verbose = 1;
 628               fprintf (TB_OUT_FILE, "Verbose on.\n");
 629             }
 630           else
 631             {
 632               TB_verbose = 0;
 633               fprintf (TB_OUT_FILE, "Verbose off.\n");
 634             }
 635           break;
 636
 637         case TB_EXIT:
 638         case TB_QUIT:
 639           /* Just exit from this function.  */
 640           goto ret;
 641
 642         default:
 643           TB_NIY;
 644         }
 645     }
 646
 647  ret:;
 648   TB_up_ht.dispose ();
 649   return;
 650 }
 651
 652
 653 /* Search the first node in this BIND_EXPR.  */
 654
 655 static tree
 656 TB_first_in_bind (tree node)
 657 {
 658   tree t;
 659
 660   if (node == NULL_TREE)
 661     return NULL_TREE;
 662
 663   while ((t = TB_prev_expr (node)))
 664     node = t;
 665
 666   return node;
 667 }
 668
 669 /* Search the last node in this BIND_EXPR.  */
 670
 671 static tree
 672 TB_last_in_bind (tree node)
 673 {
 674   tree t;
 675
 676   if (node == NULL_TREE)
 677     return NULL_TREE;
 678
 679   while ((t = TB_next_expr (node)))
 680     node = t;
 681
 682   return node;
 683 }
 684
 685 /* Search the parent expression for this node.  */
 686
 687 static tree
 688 TB_up_expr (tree node)
 689 {
 690   tree res;
 691   if (node == NULL_TREE)
 692     return NULL_TREE;
 693
 694   res = TB_up_ht.find (node);
 695   return res;
 696 }
 697
 698 /* Search the previous expression in this BIND_EXPR.  */
 699
 700 static tree
 701 TB_prev_expr (tree node)
 702 {
 703   node = TB_current_chain_node (node);
 704
 705   if (node == NULL_TREE)
 706     return NULL_TREE;
 707
 708   node = TB_up_expr (node);
 709   if (node && TREE_CODE (node) == COMPOUND_EXPR)
 710     return node;
 711   else
 712     return NULL_TREE;
 713 }
 714
 715 /* Search the next expression in this BIND_EXPR.  */
 716
 717 static tree
 718 TB_next_expr (tree node)
 719 {
 720   node = TB_current_chain_node (node);
 721
 722   if (node == NULL_TREE)
 723     return NULL_TREE;
 724
 725   node = TREE_OPERAND (node, 1);
 726   return node;
 727 }
 728
 729 static tree
 730 TB_current_chain_node (tree node)
 731 {
 732   if (node == NULL_TREE)
 733     return NULL_TREE;
 734
 735   if (TREE_CODE (node) == COMPOUND_EXPR)
 736     return node;
 737
 738   node = TB_up_expr (node);
 739   if (node)
 740     {
 741       if (TREE_CODE (node) == COMPOUND_EXPR)
 742         return node;
 743
 744       node = TB_up_expr (node);
 745       if (TREE_CODE (node) == COMPOUND_EXPR)
 746         return node;
 747     }
 748
 749   return NULL_TREE;
 750 }
 751
 752 /* For each node store in its children nodes that the current node is their
 753    parent.  This function is used by walk_tree.  */
 754
 755 static tree
 756 store_child_info (tree *tp, int *walk_subtrees ATTRIBUTE_UNUSED,
 757                   void *data ATTRIBUTE_UNUSED)
 758 {
 759   tree node;
 760   tree_node **slot;
 761
 762   node = *tp;
 763
 764   /* 'node' is the parent of 'TREE_OPERAND (node, *)'.  */
 765   if (EXPR_P (node))
 766     {
 767       int n = TREE_OPERAND_LENGTH (node);
 768       int i;
 769       for (i = 0; i < n; i++)
 770         {
 771           tree op = TREE_OPERAND (node, i);
 772           slot = TB_up_ht.find_slot (op, INSERT);
 773           *slot = node;
 774         }
 775     }
 776
 777   /* Never stop walk_tree.  */
 778   return NULL_TREE;
 779 }
 780
 781 /* Update information about upper expressions in the hash table.  */
 782
 783 static void
 784 TB_update_up (tree node)
 785 {
 786   while (node)
 787     {
 788       walk_tree (&node, store_child_info, NULL, NULL);
 789
 790       /* Walk function's body.  */
 791       if (TREE_CODE (node) == FUNCTION_DECL)
 792         if (DECL_SAVED_TREE (node))
 793           walk_tree (&DECL_SAVED_TREE (node), store_child_info, NULL, NULL);
 794
 795       /* Walk rest of the chain.  */
 796       node = TREE_CHAIN (node);
 797     }
 798   fprintf (TB_OUT_FILE, "Up/prev expressions updated.\n");
 799 }
 800
 801 /* Parse the input string for determining the command the user asked for.  */
 802
 803 static TB_CODE
 804 TB_get_command (char *input)
 805 {
 806   unsigned int mn, size_tok;
 807   int comp;
 808   char *space;
 809
 810   space = strchr (input, ' ');
 811   if (space != NULL)
 812     size_tok = strlen (input) - strlen (space);
 813   else
 814     size_tok = strlen (input) - 1;
 815
 816   for (mn = 0; mn < TB_UNUSED_COMMAND; mn++)
 817     {
 818       if (size_tok != TB_COMMAND_LEN (mn))
 819         continue;
 820
 821       comp = memcmp (input, TB_COMMAND_TEXT (mn), TB_COMMAND_LEN (mn));
 822       if (comp == 0)
 823         /* Here we just determined the command.  If this command takes
 824            an argument, then the argument is determined later.  */
 825         return TB_COMMAND_CODE (mn);
 826     }
 827
 828   /* Not a valid command.  */
 829   return TB_UNUSED_COMMAND;
 830 }
 831
 832 /* Parse the input string for determining the tree code.  */
 833
 834 static enum tree_code
 835 TB_get_tree_code (char *input)
 836 {
 837   unsigned int mn, size_tok;
 838   int comp;
 839   char *space;
 840
 841   space = strchr (input, ' ');
 842   if (space != NULL)
 843     size_tok = strlen (input) - strlen (space);
 844   else
 845     size_tok = strlen (input) - 1;
 846
 847   for (mn = 0; mn < LAST_AND_UNUSED_TREE_CODE; mn++)
 848     {
 849       if (size_tok != TB_TREE_CODE_LEN (mn))
 850         continue;
 851
 852       comp = memcmp (input, TB_TREE_CODE_TEXT (mn), TB_TREE_CODE_LEN (mn));
 853       if (comp == 0)
 854         {
 855           fprintf (TB_OUT_FILE, "%s\n", TB_TREE_CODE_TEXT (mn));
 856           return TB_TREE_CODE (mn);
 857         }
 858     }
 859
 860   /* This isn't a valid code.  */
 861   return LAST_AND_UNUSED_TREE_CODE;
 862 }
 863
 864 /* Find a node with a given code.  This function is used as an argument to
 865    walk_tree.  */
 866
 867 static tree
 868 find_node_with_code (tree *tp, int *walk_subtrees ATTRIBUTE_UNUSED,
 869                      void *data)
 870 {
 871   enum tree_code *code;
 872   code = (enum tree_code *) data;
 873   if (*code == TREE_CODE (*tp))
 874     return *tp;
 875
 876   return NULL_TREE;
 877 }
 878
 879 /* Returns a pointer to the last visited node.  */
 880
 881 static tree
 882 TB_history_prev (void)
 883 {
 884   if (!vec_safe_is_empty (TB_history_stack))
 885     {
 886       tree last = TB_history_stack->last ();
 887       TB_history_stack->pop ();
 888       return last;
 889     }
 890   return NULL_TREE;
 891 }
 892
 893 /* Read up to (and including) a '\n' from STREAM into *LINEPTR
 894    (and null-terminate it). *LINEPTR is a pointer returned from malloc
 895    (or NULL), pointing to *N characters of space.  It is realloc'd as
 896    necessary.  Returns the number of characters read (not including the
 897    null terminator), or -1 on error or EOF.
 898    This function comes from sed (and is supposed to be a portable version
 899    of getline).  */
 900
 901 static long
 902 TB_getline (char **lineptr, long *n, FILE *stream)
 903 {
 904   char *line, *p;
 905   long size, copy;
 906
 907   if (lineptr == NULL || n == NULL)
 908     {
 909       errno = EINVAL;
 910       return -1;
 911     }
 912
 913   if (ferror (stream))
 914     return -1;
 915
 916   /* Make sure we have a line buffer to start with.  */
 917   if (*lineptr == NULL || *n < 2) /* !seen and no buf yet need 2 chars.  */
 918     {
 919 #ifndef MAX_CANON
 920 #define MAX_CANON       256
 921 #endif
 922       line = (char *) xrealloc (*lineptr, MAX_CANON);
 923       if (line == NULL)
 924         return -1;
 925       *lineptr = line;
 926       *n = MAX_CANON;
 927     }
 928
 929   line = *lineptr;
 930   size = *n;
 931
 932   copy = size;
 933   p = line;
 934
 935   while (1)
 936     {
 937       long len;
 938
 939       while (--copy > 0)
 940         {
 941           register int c = getc (stream);
 942           if (c == EOF)
 943             goto lose;
 944           else if ((*p++ = c) == '\n')
 945             goto win;
 946         }
 947
 948       /* Need to enlarge the line buffer.  */
 949       len = p - line;
 950       size *= 2;
 951       line = (char *) xrealloc (line, size);
 952       if (line == NULL)
 953         goto lose;
 954       *lineptr = line;
 955       *n = size;
 956       p = line + len;
 957       copy = size - len;
 958     }
 959
 960  lose:
 961   if (p == *lineptr)
 962     return -1;
 963
 964   /* Return a partial line since we got an error in the middle.  */
 965  win:
 966 #if defined(WIN32) || defined(_WIN32) || defined(__CYGWIN__) || defined(MSDOS)
 967   if (p - 2 >= *lineptr && p[-2] == '\r')
 968     p[-2] = p[-1], --p;
 969 #endif
 970   *p = '\0';
 971   return p - *lineptr;
 972 }