gcc/tree-browser.c

   1 /* Tree browser.
   2    Copyright (C) 2002-2015 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 "alias.h"
  25 #include "symtab.h"
  26 #include "options.h"
  27 #include "tree.h"
  28 #include "tree-pretty-print.h"
  29 #include "print-tree.h"
  30
  31 #define TB_OUT_FILE stdout
  32 #define TB_IN_FILE stdin
  33 #define TB_NIY fprintf (TB_OUT_FILE, "Sorry this command is not yet implemented.\n")
  34 #define TB_WF fprintf (TB_OUT_FILE, "Warning, this command failed.\n")
  35
  36 /* Structures for handling Tree Browser's commands.  */
  37 #define DEFTBCODE(COMMAND, STRING, HELP)   COMMAND,
  38 enum TB_Comm_code {
  39 #include "tree-browser.def"
  40   TB_UNUSED_COMMAND
  41 };
  42 #undef DEFTBCODE
  43 typedef enum TB_Comm_code TB_CODE;
  44
  45 struct tb_command {
  46   const char *help_msg;
  47   const char *comm_text;
  48   size_t comm_len;
  49   TB_CODE comm_code;
  50 };
  51
  52 #define DEFTBCODE(code, str, help) { help, str, sizeof (str) - 1, code },
  53 static const struct tb_command tb_commands[] =
  54 {
  55 #include "tree-browser.def"
  56 };
  57 #undef DEFTBCODE
  58
  59 #define TB_COMMAND_LEN(N) (tb_commands[N].comm_len)
  60 #define TB_COMMAND_TEXT(N) (tb_commands[N].comm_text)
  61 #define TB_COMMAND_CODE(N) (tb_commands[N].comm_code)
  62 #define TB_COMMAND_HELP(N) (tb_commands[N].help_msg)
  63
  64
  65 /* Next structure is for parsing TREE_CODEs.  */
  66 struct tb_tree_code {
  67   enum tree_code code;
  68   const char *code_string;
  69   size_t code_string_len;
  70 };
  71
  72 #define DEFTREECODE(SYM, STRING, TYPE, NARGS) { SYM, STRING, sizeof (STRING) - 1 },
  73 #define END_OF_BASE_TREE_CODES \
  74   { LAST_AND_UNUSED_TREE_CODE, "@dummy", sizeof ("@dummy") - 1 },
  75 static const struct tb_tree_code tb_tree_codes[] =
  76 {
  77 #include "all-tree.def"
  78 };
  79 #undef DEFTREECODE
  80 #undef END_OF_BASE_TREE_CODES
  81
  82 #define TB_TREE_CODE(N) (tb_tree_codes[N].code)
  83 #define TB_TREE_CODE_TEXT(N) (tb_tree_codes[N].code_string)
  84 #define TB_TREE_CODE_LEN(N) (tb_tree_codes[N].code_string_len)
  85
  86
  87 /* Function declarations.  */
  88
  89 static long TB_getline (char **, long *, FILE *);
  90 static TB_CODE TB_get_command (char *);
  91 static enum tree_code TB_get_tree_code (char *);
  92 static tree find_node_with_code (tree *, int *, void *);
  93 static tree store_child_info (tree *, int *, void *);
  94 static void TB_update_up (tree);
  95 static tree TB_current_chain_node (tree);
  96 static tree TB_prev_expr (tree);
  97 static tree TB_next_expr (tree);
  98 static tree TB_up_expr (tree);
  99 static tree TB_first_in_bind (tree);
 100 static tree TB_last_in_bind (tree);
 101 static tree TB_history_prev (void);
 102
 103 /* FIXME: To be declared in a .h file.  */
 104 void browse_tree (tree);
 105
 106 /* Hashtable helpers.  */
 107 struct tree_upper_hasher : nofree_ptr_hash<tree_node>
 108 {
 109   static inline bool equal (const value_type &, const compare_type &);
 110 };
 111
 112 inline bool
 113 tree_upper_hasher::equal (const value_type &parent, const compare_type &node)
 114 {
 115   if (parent == NULL || node == NULL)
 116     return 0;
 117
 118   if (EXPR_P (parent))
 119     {
 120       int n = TREE_OPERAND_LENGTH (parent);
 121       int i;
 122       for (i = 0; i < n; i++)
 123         if (node == TREE_OPERAND (parent, i))
 124           return true;
 125     }
 126   return false;
 127 }
 128
 129 /* Static variables.  */
 130 static hash_table<tree_upper_hasher> *TB_up_ht;
 131 static vec<tree, va_gc> *TB_history_stack;
 132 static int TB_verbose = 1;
 133
 134
 135 /* Entry point in the Tree Browser.  */
 136
 137 void
 138 browse_tree (tree begin)
 139 {
 140   tree head;
 141   TB_CODE tbc = TB_UNUSED_COMMAND;
 142   ssize_t rd;
 143   char *input = NULL;
 144   long input_size = 0;
 145
 146   fprintf (TB_OUT_FILE, "\nTree Browser\n");
 147
 148 #define TB_SET_HEAD(N) do {                                           \
 149   vec_safe_push (TB_history_stack, N);                                \
 150   head = N;                                                           \
 151   if (TB_verbose)                                                     \
 152     if (head)                                                         \
 153       {                                                               \
 154         print_generic_expr (TB_OUT_FILE, head, 0);                    \
 155         fprintf (TB_OUT_FILE, "\n");                                  \
 156       }                                                               \
 157 } while (0)
 158
 159   TB_SET_HEAD (begin);
 160
 161   /* Store in a hashtable information about previous and upper statements.  */
 162   {
 163     TB_up_ht = new hash_table<tree_upper_hasher> (1023);
 164     TB_update_up (head);
 165   }
 166
 167   while (24)
 168     {
 169       fprintf (TB_OUT_FILE, "TB> ");
 170       rd = TB_getline (&input, &input_size, TB_IN_FILE);
 171
 172       if (rd == -1)
 173         /* EOF.  */
 174         goto ret;
 175
 176       if (rd != 1)
 177         /* Get a new command.  Otherwise the user just pressed enter, and thus
 178            she expects the last command to be reexecuted.  */
 179         tbc = TB_get_command (input);
 180
 181       switch (tbc)
 182         {
 183         case TB_UPDATE_UP:
 184           TB_update_up (head);
 185           break;
 186
 187         case TB_MAX:
 188           if (head && (INTEGRAL_TYPE_P (head)
 189                        || TREE_CODE (head) == REAL_TYPE
 190                        || TREE_CODE (head) == FIXED_POINT_TYPE))
 191             TB_SET_HEAD (TYPE_MAX_VALUE (head));
 192           else
 193             TB_WF;
 194           break;
 195
 196         case TB_MIN:
 197           if (head && (INTEGRAL_TYPE_P (head)
 198                        || TREE_CODE (head) == REAL_TYPE
 199                        || TREE_CODE (head) == FIXED_POINT_TYPE))
 200             TB_SET_HEAD (TYPE_MIN_VALUE (head));
 201           else
 202             TB_WF;
 203           break;
 204
 205         case TB_ELT:
 206           if (head && TREE_CODE (head) == TREE_VEC)
 207             {
 208               /* This command takes another argument: the element number:
 209                  for example "elt 1".  */
 210               TB_NIY;
 211             }
 212           else if (head && TREE_CODE (head) == VECTOR_CST)
 213             {
 214               /* This command takes another argument: the element number:
 215                  for example "elt 1".  */
 216               TB_NIY;
 217             }
 218           else
 219             TB_WF;
 220           break;
 221
 222         case TB_VALUE:
 223           if (head && TREE_CODE (head) == TREE_LIST)
 224             TB_SET_HEAD (TREE_VALUE (head));
 225           else
 226             TB_WF;
 227           break;
 228
 229         case TB_PURPOSE:
 230           if (head && TREE_CODE (head) == TREE_LIST)
 231             TB_SET_HEAD (TREE_PURPOSE (head));
 232           else
 233             TB_WF;
 234           break;
 235
 236         case TB_IMAG:
 237           if (head && TREE_CODE (head) == COMPLEX_CST)
 238             TB_SET_HEAD (TREE_IMAGPART (head));
 239           else
 240             TB_WF;
 241           break;
 242
 243         case TB_REAL:
 244           if (head && TREE_CODE (head) == COMPLEX_CST)
 245             TB_SET_HEAD (TREE_REALPART (head));
 246           else
 247             TB_WF;
 248           break;
 249
 250         case TB_BLOCK:
 251           if (head && TREE_CODE (head) == BIND_EXPR)
 252             TB_SET_HEAD (TREE_OPERAND (head, 2));
 253           else
 254             TB_WF;
 255           break;
 256
 257         case TB_SUBBLOCKS:
 258           if (head && TREE_CODE (head) == BLOCK)
 259             TB_SET_HEAD (BLOCK_SUBBLOCKS (head));
 260           else
 261             TB_WF;
 262           break;
 263
 264         case TB_SUPERCONTEXT:
 265           if (head && TREE_CODE (head) == BLOCK)
 266             TB_SET_HEAD (BLOCK_SUPERCONTEXT (head));
 267           else
 268             TB_WF;
 269           break;
 270
 271         case TB_VARS:
 272           if (head && TREE_CODE (head) == BLOCK)
 273             TB_SET_HEAD (BLOCK_VARS (head));
 274           else if (head && TREE_CODE (head) == BIND_EXPR)
 275             TB_SET_HEAD (TREE_OPERAND (head, 0));
 276           else
 277             TB_WF;
 278           break;
 279
 280         case TB_REFERENCE_TO_THIS:
 281           if (head && TYPE_P (head))
 282             TB_SET_HEAD (TYPE_REFERENCE_TO (head));
 283           else
 284             TB_WF;
 285           break;
 286
 287         case TB_POINTER_TO_THIS:
 288           if (head && TYPE_P (head))
 289             TB_SET_HEAD (TYPE_POINTER_TO (head));
 290           else
 291             TB_WF;
 292           break;
 293
 294         case TB_BASETYPE:
 295           if (head && TREE_CODE (head) == OFFSET_TYPE)
 296             TB_SET_HEAD (TYPE_OFFSET_BASETYPE (head));
 297           else
 298             TB_WF;
 299           break;
 300
 301         case TB_ARG_TYPES:
 302           if (head && (TREE_CODE (head) == FUNCTION_TYPE
 303                        || TREE_CODE (head) == METHOD_TYPE))
 304             TB_SET_HEAD (TYPE_ARG_TYPES (head));
 305           else
 306             TB_WF;
 307           break;
 308
 309         case TB_METHOD_BASE_TYPE:
 310           if (head && (TREE_CODE (head) == FUNCTION_TYPE
 311                        || TREE_CODE (head) == METHOD_TYPE)
 312               && TYPE_METHOD_BASETYPE (head))
 313             TB_SET_HEAD (TYPE_METHOD_BASETYPE (head));
 314           else
 315             TB_WF;
 316           break;
 317
 318         case TB_FIELDS:
 319           if (head && (TREE_CODE (head) == RECORD_TYPE
 320                        || TREE_CODE (head) == UNION_TYPE
 321                        || TREE_CODE (head) == QUAL_UNION_TYPE))
 322             TB_SET_HEAD (TYPE_FIELDS (head));
 323           else
 324             TB_WF;
 325           break;
 326
 327         case TB_DOMAIN:
 328           if (head && TREE_CODE (head) == ARRAY_TYPE)
 329             TB_SET_HEAD (TYPE_DOMAIN (head));
 330           else
 331             TB_WF;
 332           break;
 333
 334         case TB_VALUES:
 335           if (head && TREE_CODE (head) == ENUMERAL_TYPE)
 336             TB_SET_HEAD (TYPE_VALUES (head));
 337           else
 338             TB_WF;
 339           break;
 340
 341         case TB_ARG_TYPE:
 342           if (head && TREE_CODE (head) == PARM_DECL)
 343             TB_SET_HEAD (DECL_ARG_TYPE (head));
 344           else
 345             TB_WF;
 346           break;
 347
 348         case TB_INITIAL:
 349           if (head && DECL_P (head))
 350             TB_SET_HEAD (DECL_INITIAL (head));
 351           else
 352             TB_WF;
 353           break;
 354
 355         case TB_RESULT:
 356           if (head && DECL_P (head))
 357             TB_SET_HEAD (DECL_RESULT_FLD (head));
 358           else
 359             TB_WF;
 360           break;
 361
 362         case TB_ARGUMENTS:
 363           if (head && DECL_P (head))
 364             TB_SET_HEAD (DECL_ARGUMENTS (head));
 365           else
 366             TB_WF;
 367           break;
 368
 369         case TB_ABSTRACT_ORIGIN:
 370           if (head && DECL_P (head))
 371             TB_SET_HEAD (DECL_ABSTRACT_ORIGIN (head));
 372           else if (head && TREE_CODE (head) == BLOCK)
 373             TB_SET_HEAD (BLOCK_ABSTRACT_ORIGIN (head));
 374           else
 375             TB_WF;
 376           break;
 377
 378         case TB_ATTRIBUTES:
 379           if (head && DECL_P (head))
 380             TB_SET_HEAD (DECL_ATTRIBUTES (head));
 381           else if (head && TYPE_P (head))
 382             TB_SET_HEAD (TYPE_ATTRIBUTES (head));
 383           else
 384             TB_WF;
 385           break;
 386
 387         case TB_CONTEXT:
 388           if (head && DECL_P (head))
 389             TB_SET_HEAD (DECL_CONTEXT (head));
 390           else if (head && TYPE_P (head)
 391                    && TYPE_CONTEXT (head))
 392             TB_SET_HEAD (TYPE_CONTEXT (head));
 393           else
 394             TB_WF;
 395           break;
 396
 397         case TB_OFFSET:
 398           if (head && TREE_CODE (head) == FIELD_DECL)
 399             TB_SET_HEAD (DECL_FIELD_OFFSET (head));
 400           else
 401             TB_WF;
 402           break;
 403
 404         case TB_BIT_OFFSET:
 405           if (head && TREE_CODE (head) == FIELD_DECL)
 406             TB_SET_HEAD (DECL_FIELD_BIT_OFFSET (head));
 407           else
 408             TB_WF;
 409           break;
 410
 411         case TB_UNIT_SIZE:
 412           if (head && DECL_P (head))
 413             TB_SET_HEAD (DECL_SIZE_UNIT (head));
 414           else if (head && TYPE_P (head))
 415             TB_SET_HEAD (TYPE_SIZE_UNIT (head));
 416           else
 417             TB_WF;
 418           break;
 419
 420         case TB_SIZE:
 421           if (head && DECL_P (head))
 422             TB_SET_HEAD (DECL_SIZE (head));
 423           else if (head && TYPE_P (head))
 424             TB_SET_HEAD (TYPE_SIZE (head));
 425           else
 426             TB_WF;
 427           break;
 428
 429         case TB_TYPE:
 430           if (head && TREE_TYPE (head))
 431             TB_SET_HEAD (TREE_TYPE (head));
 432           else
 433             TB_WF;
 434           break;
 435
 436         case TB_DECL_SAVED_TREE:
 437           if (head && TREE_CODE (head) == FUNCTION_DECL
 438               && DECL_SAVED_TREE (head))
 439             TB_SET_HEAD (DECL_SAVED_TREE (head));
 440           else
 441             TB_WF;
 442           break;
 443
 444         case TB_BODY:
 445           if (head && TREE_CODE (head) == BIND_EXPR)
 446             TB_SET_HEAD (TREE_OPERAND (head, 1));
 447           else
 448             TB_WF;
 449           break;
 450
 451         case TB_CHILD_0:
 452           if (head && EXPR_P (head) && TREE_OPERAND (head, 0))
 453             TB_SET_HEAD (TREE_OPERAND (head, 0));
 454           else
 455             TB_WF;
 456           break;
 457
 458         case TB_CHILD_1:
 459           if (head && EXPR_P (head) && TREE_OPERAND (head, 1))
 460             TB_SET_HEAD (TREE_OPERAND (head, 1));
 461           else
 462             TB_WF;
 463           break;
 464
 465         case TB_CHILD_2:
 466           if (head && EXPR_P (head) && TREE_OPERAND (head, 2))
 467             TB_SET_HEAD (TREE_OPERAND (head, 2));
 468           else
 469             TB_WF;
 470           break;
 471
 472         case TB_CHILD_3:
 473           if (head && EXPR_P (head) && TREE_OPERAND (head, 3))
 474             TB_SET_HEAD (TREE_OPERAND (head, 3));
 475           else
 476             TB_WF;
 477           break;
 478
 479         case TB_PRINT:
 480           if (head)
 481             debug_tree (head);
 482           else
 483             TB_WF;
 484           break;
 485
 486         case TB_PRETTY_PRINT:
 487           if (head)
 488             {
 489               print_generic_stmt (TB_OUT_FILE, head, 0);
 490               fprintf (TB_OUT_FILE, "\n");
 491             }
 492           else
 493             TB_WF;
 494           break;
 495
 496         case TB_SEARCH_NAME:
 497
 498           break;
 499
 500         case TB_SEARCH_CODE:
 501           {
 502             enum tree_code code;
 503             char *arg_text;
 504
 505             arg_text = strchr (input, ' ');
 506             if (arg_text == NULL)
 507               {
 508                 fprintf (TB_OUT_FILE, "First argument is missing.  This isn't a valid search command.  \n");
 509                 break;
 510               }
 511             code = TB_get_tree_code (arg_text + 1);
 512
 513             /* Search in the subtree a node with the given code.  */
 514             {
 515               tree res;
 516
 517               res = walk_tree (&head, find_node_with_code, &code, NULL);
 518               if (res == NULL_TREE)
 519                 {
 520                   fprintf (TB_OUT_FILE, "There's no node with this code (reachable via the walk_tree function from this node).\n");
 521                 }
 522               else
 523                 {
 524                   fprintf (TB_OUT_FILE, "Achoo!  I got this node in the tree.\n");
 525                   TB_SET_HEAD (res);
 526                 }
 527             }
 528             break;
 529           }
 530
 531 #define TB_MOVE_HEAD(FCT) do {       \
 532   if (head)                          \
 533     {                                \
 534       tree t;                        \
 535       t = FCT (head);                \
 536       if (t)                         \
 537         TB_SET_HEAD (t);             \
 538       else                           \
 539         TB_WF;                       \
 540     }                                \
 541   else                               \
 542     TB_WF;                           \
 543 } while (0)
 544
 545         case TB_FIRST:
 546           TB_MOVE_HEAD (TB_first_in_bind);
 547           break;
 548
 549         case TB_LAST:
 550           TB_MOVE_HEAD (TB_last_in_bind);
 551           break;
 552
 553         case TB_UP:
 554           TB_MOVE_HEAD (TB_up_expr);
 555           break;
 556
 557         case TB_PREV:
 558           TB_MOVE_HEAD (TB_prev_expr);
 559           break;
 560
 561         case TB_NEXT:
 562           TB_MOVE_HEAD (TB_next_expr);
 563           break;
 564
 565         case TB_HPREV:
 566           /* This command is a little bit special, since it deals with history
 567              stack.  For this reason it should keep the "head = ..." statement
 568              and not use TB_MOVE_HEAD.  */
 569           if (head)
 570             {
 571               tree t;
 572               t = TB_history_prev ();
 573               if (t)
 574                 {
 575                   head = t;
 576                   if (TB_verbose)
 577                     {
 578                       print_generic_expr (TB_OUT_FILE, head, 0);
 579                       fprintf (TB_OUT_FILE, "\n");
 580                     }
 581                 }
 582               else
 583                 TB_WF;
 584             }
 585           else
 586             TB_WF;
 587           break;
 588
 589         case TB_CHAIN:
 590           /* Don't go further if it's the last node in this chain.  */
 591           if (head && TREE_CODE (head) == BLOCK)
 592             TB_SET_HEAD (BLOCK_CHAIN (head));
 593           else if (head && TREE_CHAIN (head))
 594             TB_SET_HEAD (TREE_CHAIN (head));
 595           else
 596             TB_WF;
 597           break;
 598
 599         case TB_FUN:
 600           /* Go up to the current function declaration.  */
 601           TB_SET_HEAD (current_function_decl);
 602           fprintf (TB_OUT_FILE, "Current function declaration.\n");
 603           break;
 604
 605         case TB_HELP:
 606           /* Display a help message.  */
 607           {
 608             int i;
 609             fprintf (TB_OUT_FILE, "Possible commands are:\n\n");
 610             for (i = 0; i < TB_UNUSED_COMMAND; i++)
 611               {
 612                 fprintf (TB_OUT_FILE, "%20s  -  %s\n", TB_COMMAND_TEXT (i), TB_COMMAND_HELP (i));
 613               }
 614           }
 615           break;
 616
 617         case TB_VERBOSE:
 618           if (TB_verbose == 0)
 619             {
 620               TB_verbose = 1;
 621               fprintf (TB_OUT_FILE, "Verbose on.\n");
 622             }
 623           else
 624             {
 625               TB_verbose = 0;
 626               fprintf (TB_OUT_FILE, "Verbose off.\n");
 627             }
 628           break;
 629
 630         case TB_EXIT:
 631         case TB_QUIT:
 632           /* Just exit from this function.  */
 633           goto ret;
 634
 635         default:
 636           TB_NIY;
 637         }
 638     }
 639
 640  ret:;
 641   delete TB_up_ht;
 642   TB_up_ht = NULL;
 643   return;
 644 }
 645
 646
 647 /* Search the first node in this BIND_EXPR.  */
 648
 649 static tree
 650 TB_first_in_bind (tree node)
 651 {
 652   tree t;
 653
 654   if (node == NULL_TREE)
 655     return NULL_TREE;
 656
 657   while ((t = TB_prev_expr (node)))
 658     node = t;
 659
 660   return node;
 661 }
 662
 663 /* Search the last node in this BIND_EXPR.  */
 664
 665 static tree
 666 TB_last_in_bind (tree node)
 667 {
 668   tree t;
 669
 670   if (node == NULL_TREE)
 671     return NULL_TREE;
 672
 673   while ((t = TB_next_expr (node)))
 674     node = t;
 675
 676   return node;
 677 }
 678
 679 /* Search the parent expression for this node.  */
 680
 681 static tree
 682 TB_up_expr (tree node)
 683 {
 684   tree res;
 685   if (node == NULL_TREE)
 686     return NULL_TREE;
 687
 688   res = TB_up_ht->find (node);
 689   return res;
 690 }
 691
 692 /* Search the previous expression in this BIND_EXPR.  */
 693
 694 static tree
 695 TB_prev_expr (tree node)
 696 {
 697   node = TB_current_chain_node (node);
 698
 699   if (node == NULL_TREE)
 700     return NULL_TREE;
 701
 702   node = TB_up_expr (node);
 703   if (node && TREE_CODE (node) == COMPOUND_EXPR)
 704     return node;
 705   else
 706     return NULL_TREE;
 707 }
 708
 709 /* Search the next expression in this BIND_EXPR.  */
 710
 711 static tree
 712 TB_next_expr (tree node)
 713 {
 714   node = TB_current_chain_node (node);
 715
 716   if (node == NULL_TREE)
 717     return NULL_TREE;
 718
 719   node = TREE_OPERAND (node, 1);
 720   return node;
 721 }
 722
 723 static tree
 724 TB_current_chain_node (tree node)
 725 {
 726   if (node == NULL_TREE)
 727     return NULL_TREE;
 728
 729   if (TREE_CODE (node) == COMPOUND_EXPR)
 730     return node;
 731
 732   node = TB_up_expr (node);
 733   if (node)
 734     {
 735       if (TREE_CODE (node) == COMPOUND_EXPR)
 736         return node;
 737
 738       node = TB_up_expr (node);
 739       if (TREE_CODE (node) == COMPOUND_EXPR)
 740         return node;
 741     }
 742
 743   return NULL_TREE;
 744 }
 745
 746 /* For each node store in its children nodes that the current node is their
 747    parent.  This function is used by walk_tree.  */
 748
 749 static tree
 750 store_child_info (tree *tp, int *walk_subtrees ATTRIBUTE_UNUSED,
 751                   void *data ATTRIBUTE_UNUSED)
 752 {
 753   tree node;
 754   tree_node **slot;
 755
 756   node = *tp;
 757
 758   /* 'node' is the parent of 'TREE_OPERAND (node, *)'.  */
 759   if (EXPR_P (node))
 760     {
 761       int n = TREE_OPERAND_LENGTH (node);
 762       int i;
 763       for (i = 0; i < n; i++)
 764         {
 765           tree op = TREE_OPERAND (node, i);
 766           slot = TB_up_ht->find_slot (op, INSERT);
 767           *slot = node;
 768         }
 769     }
 770
 771   /* Never stop walk_tree.  */
 772   return NULL_TREE;
 773 }
 774
 775 /* Update information about upper expressions in the hash table.  */
 776
 777 static void
 778 TB_update_up (tree node)
 779 {
 780   while (node)
 781     {
 782       walk_tree (&node, store_child_info, NULL, NULL);
 783
 784       /* Walk function's body.  */
 785       if (TREE_CODE (node) == FUNCTION_DECL)
 786         if (DECL_SAVED_TREE (node))
 787           walk_tree (&DECL_SAVED_TREE (node), store_child_info, NULL, NULL);
 788
 789       /* Walk rest of the chain.  */
 790       node = TREE_CHAIN (node);
 791     }
 792   fprintf (TB_OUT_FILE, "Up/prev expressions updated.\n");
 793 }
 794
 795 /* Parse the input string for determining the command the user asked for.  */
 796
 797 static TB_CODE
 798 TB_get_command (char *input)
 799 {
 800   unsigned int mn, size_tok;
 801   int comp;
 802   char *space;
 803
 804   space = strchr (input, ' ');
 805   if (space != NULL)
 806     size_tok = strlen (input) - strlen (space);
 807   else
 808     size_tok = strlen (input) - 1;
 809
 810   for (mn = 0; mn < TB_UNUSED_COMMAND; mn++)
 811     {
 812       if (size_tok != TB_COMMAND_LEN (mn))
 813         continue;
 814
 815       comp = memcmp (input, TB_COMMAND_TEXT (mn), TB_COMMAND_LEN (mn));
 816       if (comp == 0)
 817         /* Here we just determined the command.  If this command takes
 818            an argument, then the argument is determined later.  */
 819         return TB_COMMAND_CODE (mn);
 820     }
 821
 822   /* Not a valid command.  */
 823   return TB_UNUSED_COMMAND;
 824 }
 825
 826 /* Parse the input string for determining the tree code.  */
 827
 828 static enum tree_code
 829 TB_get_tree_code (char *input)
 830 {
 831   unsigned int mn, size_tok;
 832   int comp;
 833   char *space;
 834
 835   space = strchr (input, ' ');
 836   if (space != NULL)
 837     size_tok = strlen (input) - strlen (space);
 838   else
 839     size_tok = strlen (input) - 1;
 840
 841   for (mn = 0; mn < LAST_AND_UNUSED_TREE_CODE; mn++)
 842     {
 843       if (size_tok != TB_TREE_CODE_LEN (mn))
 844         continue;
 845
 846       comp = memcmp (input, TB_TREE_CODE_TEXT (mn), TB_TREE_CODE_LEN (mn));
 847       if (comp == 0)
 848         {
 849           fprintf (TB_OUT_FILE, "%s\n", TB_TREE_CODE_TEXT (mn));
 850           return TB_TREE_CODE (mn);
 851         }
 852     }
 853
 854   /* This isn't a valid code.  */
 855   return LAST_AND_UNUSED_TREE_CODE;
 856 }
 857
 858 /* Find a node with a given code.  This function is used as an argument to
 859    walk_tree.  */
 860
 861 static tree
 862 find_node_with_code (tree *tp, int *walk_subtrees ATTRIBUTE_UNUSED,
 863                      void *data)
 864 {
 865   enum tree_code *code;
 866   code = (enum tree_code *) data;
 867   if (*code == TREE_CODE (*tp))
 868     return *tp;
 869
 870   return NULL_TREE;
 871 }
 872
 873 /* Returns a pointer to the last visited node.  */
 874
 875 static tree
 876 TB_history_prev (void)
 877 {
 878   if (!vec_safe_is_empty (TB_history_stack))
 879     {
 880       tree last = TB_history_stack->last ();
 881       TB_history_stack->pop ();
 882       return last;
 883     }
 884   return NULL_TREE;
 885 }
 886
 887 /* Read up to (and including) a '\n' from STREAM into *LINEPTR
 888    (and null-terminate it). *LINEPTR is a pointer returned from malloc
 889    (or NULL), pointing to *N characters of space.  It is realloc'd as
 890    necessary.  Returns the number of characters read (not including the
 891    null terminator), or -1 on error or EOF.
 892    This function comes from sed (and is supposed to be a portable version
 893    of getline).  */
 894
 895 static long
 896 TB_getline (char **lineptr, long *n, FILE *stream)
 897 {
 898   char *line, *p;
 899   long size, copy;
 900
 901   if (lineptr == NULL || n == NULL)
 902     {
 903       errno = EINVAL;
 904       return -1;
 905     }
 906
 907   if (ferror (stream))
 908     return -1;
 909
 910   /* Make sure we have a line buffer to start with.  */
 911   if (*lineptr == NULL || *n < 2) /* !seen and no buf yet need 2 chars.  */
 912     {
 913 #ifndef MAX_CANON
 914 #define MAX_CANON       256
 915 #endif
 916       line = (char *) xrealloc (*lineptr, MAX_CANON);
 917       if (line == NULL)
 918         return -1;
 919       *lineptr = line;
 920       *n = MAX_CANON;
 921     }
 922
 923   line = *lineptr;
 924   size = *n;
 925
 926   copy = size;
 927   p = line;
 928
 929   while (1)
 930     {
 931       long len;
 932
 933       while (--copy > 0)
 934         {
 935           register int c = getc (stream);
 936           if (c == EOF)
 937             goto lose;
 938           else if ((*p++ = c) == '\n')
 939             goto win;
 940         }
 941
 942       /* Need to enlarge the line buffer.  */
 943       len = p - line;
 944       size *= 2;
 945       line = (char *) xrealloc (line, size);
 946       if (line == NULL)
 947         goto lose;
 948       *lineptr = line;
 949       *n = size;
 950       p = line + len;
 951       copy = size - len;
 952     }
 953
 954  lose:
 955   if (p == *lineptr)
 956     return -1;
 957
 958   /* Return a partial line since we got an error in the middle.  */
 959  win:
 960 #if defined(WIN32) || defined(_WIN32) || defined(__CYGWIN__) || defined(MSDOS)
 961   if (p - 2 >= *lineptr && p[-2] == '\r')
 962     p[-2] = p[-1], --p;
 963 #endif
 964   *p = '\0';
 965   return p - *lineptr;
 966 }