gcc/function.h

   1 /* Structure for saving state for a nested function.
   2    Copyright (C) 1989, 92-97, 1998 Free Software Foundation, Inc.
   3
   4 This file is part of GNU CC.
   5
   6 GNU CC is free software; you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation; either version 2, or (at your option)
   9 any later version.
  10
  11 GNU CC is distributed in the hope that it will be useful,
  12 but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 GNU General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GNU CC; see the file COPYING.  If not, write to
  18 the Free Software Foundation, 59 Temple Place - Suite 330,
  19 Boston, MA 02111-1307, USA.  */
  20
  21
  22 #if !defined(NULL_TREE) && !defined(tree)
  23 typedef union union_node *_function_tree;
  24 #define tree _function_tree
  25 #endif
  26 #if !defined(NULL_RTX) && !defined(rtx)
  27 typedef struct rtx_def *_function_rtx;
  28 #define rtx _function_rtx
  29 #endif
  30
  31 struct var_refs_queue
  32 {
  33   rtx modified;
  34   enum machine_mode promoted_mode;
  35   int unsignedp;
  36   struct var_refs_queue *next;
  37 };
  38
  39 /* Stack of pending (incomplete) sequences saved by `start_sequence'.
  40    Each element describes one pending sequence.
  41    The main insn-chain is saved in the last element of the chain,
  42    unless the chain is empty.  */
  43
  44 struct sequence_stack
  45 {
  46   /* First and last insns in the chain of the saved sequence.  */
  47   rtx first, last;
  48   tree sequence_rtl_expr;
  49   struct sequence_stack *next;
  50 };
  51
  52 extern struct sequence_stack *sequence_stack;
  53
  54 /* Stack of single obstacks.  */
  55
  56 struct simple_obstack_stack
  57 {
  58   struct obstack *obstack;
  59   struct simple_obstack_stack *next;
  60 };
  61 \f
  62 struct emit_status
  63 {
  64   /* This is reset to LAST_VIRTUAL_REGISTER + 1 at the start of each function.
  65      After rtl generation, it is 1 plus the largest register number used.  */
  66   int x_reg_rtx_no;
  67
  68   /* Lowest label number in current function.  */
  69   int x_first_label_num;
  70
  71   /* The ends of the doubly-linked chain of rtl for the current function.
  72      Both are reset to null at the start of rtl generation for the function.
  73
  74      start_sequence saves both of these on `sequence_stack' along with
  75      `sequence_rtl_expr' and then starts a new, nested sequence of insns.  */
  76   rtx x_first_insn;
  77   rtx x_last_insn;
  78
  79   /* RTL_EXPR within which the current sequence will be placed.  Use to
  80      prevent reuse of any temporaries within the sequence until after the
  81      RTL_EXPR is emitted.  */
  82   tree sequence_rtl_expr;
  83
  84   /* Stack of pending (incomplete) sequences saved by `start_sequence'.
  85      Each element describes one pending sequence.
  86      The main insn-chain is saved in the last element of the chain,
  87      unless the chain is empty.  */
  88   struct sequence_stack *sequence_stack;
  89
  90   /* INSN_UID for next insn emitted.
  91      Reset to 1 for each function compiled.  */
  92   int x_cur_insn_uid;
  93
  94   /* Line number and source file of the last line-number NOTE emitted.
  95      This is used to avoid generating duplicates.  */
  96   int x_last_linenum;
  97   char *x_last_filename;
  98
  99   /* A vector indexed by pseudo reg number.  The allocated length
 100      of this vector is regno_pointer_flag_length.  Since this
 101      vector is needed during the expansion phase when the total
 102      number of registers in the function is not yet known,
 103      it is copied and made bigger when necessary.  */
 104   char *regno_pointer_flag;
 105   int regno_pointer_flag_length;
 106
 107   /* Indexed by pseudo register number, if nonzero gives the known alignment
 108      for that pseudo (if regno_pointer_flag is set).
 109      Allocated in parallel with regno_pointer_flag.  */
 110   char *regno_pointer_align;
 111
 112   /* Indexed by pseudo register number, gives the rtx for that pseudo.
 113      Allocated in parallel with regno_pointer_flag.  */
 114   rtx *x_regno_reg_rtx;
 115 };
 116
 117 /* For backward compatibility... eventually these should all go away.  */
 118 #define reg_rtx_no (current_function->emit->x_reg_rtx_no)
 119 #define seq_rtl_expr (current_function->emit->sequence_rtl_expr)
 120 #define regno_reg_rtx (current_function->emit->x_regno_reg_rtx)
 121 #define seq_stack (current_function->emit->sequence_stack)
 122
 123 #define REGNO_POINTER_ALIGN(REGNO) \
 124   (current_function->emit->regno_pointer_align[REGNO])
 125 #define REGNO_POINTER_FLAG(REGNO) \
 126   (current_function->emit->regno_pointer_flag[REGNO])
 127
 128 struct expr_status
 129 {
 130   /* Number of units that we should eventually pop off the stack.
 131      These are the arguments to function calls that have already returned.  */
 132   int x_pending_stack_adjust;
 133
 134   /* Under some ABIs, it is the caller's responsibility to pop arguments
 135      pushed for function calls.  A naive implementation would simply pop
 136      the arguments immediately after each call.  However, if several
 137      function calls are made in a row, it is typically cheaper to pop
 138      all the arguments after all of the calls are complete since a
 139      single pop instruction can be used.  Therefore, GCC attempts to
 140      defer popping the arguments until absolutely necessary.  (For
 141      example, at the end of a conditional, the arguments must be popped,
 142      since code outside the conditional won't know whether or not the
 143      arguments need to be popped.)
 144
 145      When INHIBIT_DEFER_POP is non-zero, however, the compiler does not
 146      attempt to defer pops.  Instead, the stack is popped immediately
 147      after each call.  Rather then setting this variable directly, use
 148      NO_DEFER_POP and OK_DEFER_POP.  */
 149   int x_inhibit_defer_pop;
 150
 151   /* Nonzero means __builtin_saveregs has already been done in this function.
 152      The value is the pseudoreg containing the value __builtin_saveregs
 153      returned.  */
 154   rtx x_saveregs_value;
 155
 156   /* Similarly for __builtin_apply_args.  */
 157   rtx x_apply_args_value;
 158
 159   /* List of labels that must never be deleted.  */
 160   rtx x_forced_labels;
 161
 162   /* Postincrements that still need to be expanded.  */
 163   rtx x_pending_chain;
 164 };
 165
 166 #define pending_stack_adjust (current_function->expr->x_pending_stack_adjust)
 167 #define inhibit_defer_pop (current_function->expr->x_inhibit_defer_pop)
 168 #define saveregs_value (current_function->expr->x_saveregs_value)
 169 #define apply_args_value (current_function->expr->x_apply_args_value)
 170 #define forced_labels (current_function->expr->x_forced_labels)
 171 #define pending_chain (current_function->expr->x_pending_chain)
 172
 173 /* This structure can save all the important global and static variables
 174    describing the status of the current function.  */
 175
 176 struct function
 177 {
 178   struct function *next_global;
 179   struct function *next;
 180
 181   struct eh_status *eh;
 182   struct stmt_status *stmt;
 183   struct expr_status *expr;
 184   struct emit_status *emit;
 185   struct varasm_status *varasm;
 186
 187   /* For function.c.  */
 188
 189   /* Name of this function.  */
 190   const char *name;
 191   /* Points to the FUNCTION_DECL of this function. */
 192   tree decl;
 193
 194   /* Number of bytes of args popped by function being compiled on its return.
 195      Zero if no bytes are to be popped.
 196      May affect compilation of return insn or of function epilogue.  */
 197   int pops_args;
 198
 199   /* Nonzero if function being compiled needs to be given an address
 200      where the value should be stored.  */
 201   int returns_struct;
 202
 203   /* Nonzero if function being compiled needs to
 204      return the address of where it has put a structure value.  */
 205   int returns_pcc_struct;
 206
 207   /* Nonzero if the current function returns a pointer type.  */
 208   int returns_pointer;
 209
 210   /* Nonzero if function being compiled needs to be passed a static chain.  */
 211   int needs_context;
 212
 213   /* Nonzero if function being compiled can call setjmp.  */
 214   int calls_setjmp;
 215
 216   /* Nonzero if function being compiled can call longjmp.  */
 217   int calls_longjmp;
 218
 219   /* Nonzero if function being compiled can call alloca,
 220      either as a subroutine or builtin.  */
 221   int calls_alloca;
 222
 223   /* Nonzero if function being compiled receives nonlocal gotos
 224      from nested functions.  */
 225
 226   int has_nonlocal_label;
 227
 228   /* Nonzero if function being compiled has nonlocal gotos to parent
 229      function.  */
 230   int has_nonlocal_goto;
 231
 232   /* Nonzero if function being compiled contains nested functions.  */
 233   int contains_functions;
 234
 235   /* Nonzero if the function being compiled issues a computed jump.  */
 236   int has_computed_jump;
 237
 238   /* Nonzero if the current function is a thunk (a lightweight function that
 239      just adjusts one of its arguments and forwards to another function), so
 240      we should try to cut corners where we can.  */
 241   int is_thunk;
 242
 243   /* If function's args have a fixed size, this is that size, in bytes.
 244      Otherwise, it is -1.
 245      May affect compilation of return insn or of function epilogue.  */
 246   int args_size;
 247
 248   /* # bytes the prologue should push and pretend that the caller pushed them.
 249      The prologue must do this, but only if parms can be passed in
 250      registers.  */
 251   int pretend_args_size;
 252
 253   /* # of bytes of outgoing arguments.  If ACCUMULATE_OUTGOING_ARGS is
 254      defined, the needed space is pushed by the prologue.  */
 255   int outgoing_args_size;
 256
 257   /* This is the offset from the arg pointer to the place where the first
 258      anonymous arg can be found, if there is one.  */
 259   rtx arg_offset_rtx;
 260
 261   /* Nonzero if current function uses varargs.h or equivalent.
 262      Zero for functions that use stdarg.h.  */
 263   int varargs;
 264
 265   /* Nonzero if current function uses stdarg.h or equivalent.
 266      Zero for functions that use varargs.h.  */
 267   int stdarg;
 268
 269   /* Quantities of various kinds of registers
 270      used for the current function's args.  */
 271   CUMULATIVE_ARGS args_info;
 272
 273   /* If non-zero, an RTL expression for the location at which the current
 274      function returns its result.  If the current function returns its
 275      result in a register, current_function_return_rtx will always be
 276      the hard register containing the result.  */
 277   rtx return_rtx;
 278
 279   /* The arg pointer hard register, or the pseudo into which it was copied.  */
 280   rtx internal_arg_pointer;
 281
 282   /* Language-specific reason why the current function cannot be made
 283      inline.  */
 284   const char *cannot_inline;
 285
 286   /* Nonzero if instrumentation calls for function entry and exit should be
 287      generated.  */
 288   int instrument_entry_exit;
 289
 290   /* Nonzero if memory access checking be enabled in the current function.  */
 291   int check_memory_usage;
 292
 293   /* Number of function calls seen so far in current function.  */
 294   int x_function_call_count;
 295
 296   /* Nonzero if this function is being processed in function-at-a-time
 297      mode.  In other words, if all tree structure for this function,
 298      including the BLOCK tree is created, before RTL generation
 299      commences.  */
 300   int x_whole_function_mode_p;
 301
 302   /* List (chain of TREE_LIST) of LABEL_DECLs for all nonlocal labels
 303      (labels to which there can be nonlocal gotos from nested functions)
 304      in this function.  */
 305   tree x_nonlocal_labels;
 306
 307   /* List (chain of EXPR_LIST) of stack slots that hold the current handlers
 308      for nonlocal gotos.  There is one for every nonlocal label in the
 309      function; this list matches the one in nonlocal_labels.
 310      Zero when function does not have nonlocal labels.  */
 311   rtx x_nonlocal_goto_handler_slots;
 312
 313   /* List (chain of EXPR_LIST) of labels heading the current handlers for
 314      nonlocal gotos.  */
 315   rtx x_nonlocal_goto_handler_labels;
 316
 317   /* RTX for stack slot that holds the stack pointer value to restore
 318      for a nonlocal goto.
 319      Zero when function does not have nonlocal labels.  */
 320   rtx x_nonlocal_goto_stack_level;
 321
 322   /* Label that will go on parm cleanup code, if any.
 323      Jumping to this label runs cleanup code for parameters, if
 324      such code must be run.  Following this code is the logical return
 325      label.  */
 326   rtx x_cleanup_label;
 327
 328   /* Label that will go on function epilogue.
 329      Jumping to this label serves as a "return" instruction
 330      on machines which require execution of the epilogue on all returns.  */
 331   rtx x_return_label;
 332
 333   /* List (chain of EXPR_LISTs) of pseudo-regs of SAVE_EXPRs.
 334      So we can mark them all live at the end of the function, if nonopt.  */
 335   rtx x_save_expr_regs;
 336
 337   /* List (chain of EXPR_LISTs) of all stack slots in this function.
 338      Made for the sake of unshare_all_rtl.  */
 339   rtx x_stack_slot_list;
 340
 341   /* Chain of all RTL_EXPRs that have insns in them.  */
 342   tree x_rtl_expr_chain;
 343
 344   /* Label to jump back to for tail recursion, or 0 if we have
 345      not yet needed one for this function.  */
 346   rtx x_tail_recursion_label;
 347
 348   /* Place after which to insert the tail_recursion_label if we need one.  */
 349   rtx x_tail_recursion_reentry;
 350
 351   /* Location at which to save the argument pointer if it will need to be
 352      referenced.  There are two cases where this is done: if nonlocal gotos
 353      exist, or if vars stored at an offset from the argument pointer will be
 354      needed by inner routines.  */
 355   rtx x_arg_pointer_save_area;
 356
 357   /* Offset to end of allocated area of stack frame.
 358      If stack grows down, this is the address of the last stack slot allocated.
 359      If stack grows up, this is the address for the next slot.  */
 360   HOST_WIDE_INT x_frame_offset;
 361
 362   /* List (chain of TREE_LISTs) of static chains for containing functions.
 363      Each link has a FUNCTION_DECL in the TREE_PURPOSE and a reg rtx
 364      in an RTL_EXPR in the TREE_VALUE.  */
 365   tree x_context_display;
 366
 367   /* List (chain of TREE_LISTs) of trampolines for nested functions.
 368      The trampoline sets up the static chain and jumps to the function.
 369      We supply the trampoline's address when the function's address is
 370      requested.
 371
 372      Each link has a FUNCTION_DECL in the TREE_PURPOSE and a reg rtx
 373      in an RTL_EXPR in the TREE_VALUE.  */
 374   tree x_trampoline_list;
 375
 376   /* Insn after which register parms and SAVE_EXPRs are born, if nonopt.  */
 377   rtx x_parm_birth_insn;
 378
 379   /* Last insn of those whose job was to put parms into their nominal
 380      homes.  */
 381   rtx x_last_parm_insn;
 382
 383   /* 1 + last pseudo register number possibly used for loading a copy
 384      of a parameter of this function. */
 385   int x_max_parm_reg;
 386
 387   /* Vector indexed by REGNO, containing location on stack in which
 388      to put the parm which is nominally in pseudo register REGNO,
 389      if we discover that that parm must go in the stack.  The highest
 390      element in this vector is one less than MAX_PARM_REG, above.  */
 391   rtx *x_parm_reg_stack_loc;
 392
 393   /* List of all temporaries allocated, both available and in use.  */
 394   struct temp_slot *x_temp_slots;
 395
 396   /* Current nesting level for temporaries.  */
 397   int x_temp_slot_level;
 398
 399   /* Current nesting level for variables in a block.  */
 400   int x_var_temp_slot_level;
 401
 402   /* When temporaries are created by TARGET_EXPRs, they are created at
 403      this level of temp_slot_level, so that they can remain allocated
 404      until no longer needed.  CLEANUP_POINT_EXPRs define the lifetime
 405      of TARGET_EXPRs.  */
 406   int x_target_temp_slot_level;
 407
 408   /* This slot is initialized as 0 and is added to
 409      during the nested function.  */
 410   struct var_refs_queue *fixup_var_refs_queue;
 411
 412   /* For tree.c.  */
 413   int all_types_permanent;
 414   struct momentary_level *momentary_stack;
 415   char *maybepermanent_firstobj;
 416   char *temporary_firstobj;
 417   char *momentary_firstobj;
 418   char *momentary_function_firstobj;
 419   struct obstack *current_obstack;
 420   struct obstack *function_obstack;
 421   struct obstack *function_maybepermanent_obstack;
 422   struct obstack *expression_obstack;
 423   struct obstack *saveable_obstack;
 424   struct obstack *rtl_obstack;
 425
 426   /* For integrate.c.  */
 427   int inlinable;
 428   /* This is in fact an rtvec.  */
 429   void *original_arg_vector;
 430   tree original_decl_initial;
 431   /* Last insn of those whose job was to put parms into their nominal
 432      homes.  */
 433   rtx inl_last_parm_insn;
 434   /* Highest label number in current function.  */
 435   int inl_max_label_num;
 436
 437   /* Nonzero if the current function uses the constant pool.  */
 438   int uses_const_pool;
 439
 440   /* For md files.  */
 441
 442   /* Nonzero if the current function uses pic_offset_table_rtx.  */
 443   int uses_pic_offset_table;
 444   /* tm.h can use this to store whatever it likes.  */
 445   struct machine_function *machine;
 446
 447   /* Language-specific code can use this to store whatever it likes.  */
 448   struct language_function *language;
 449
 450   /* For reorg.  */
 451
 452   /* If some insns can be deferred to the delay slots of the epilogue, the
 453      delay list for them is recorded here.  */
 454   rtx epilogue_delay_list;
 455 };
 456
 457 extern struct function *current_function;
 458 extern struct function *all_functions;
 459
 460 /* For backward compatibility... eventually these should all go away.  */
 461 #define current_function_name (current_function->name)
 462 #define current_function_pops_args (current_function->pops_args)
 463 #define current_function_returns_struct (current_function->returns_struct)
 464 #define current_function_returns_pcc_struct (current_function->returns_pcc_struct)
 465 #define current_function_returns_pointer (current_function->returns_pointer)
 466 #define current_function_needs_context (current_function->needs_context)
 467 #define current_function_calls_setjmp (current_function->calls_setjmp)
 468 #define current_function_calls_alloca (current_function->calls_alloca)
 469 #define current_function_calls_longjmp (current_function->calls_longjmp)
 470 #define current_function_has_computed_jump (current_function->has_computed_jump)
 471 #define current_function_contains_functions (current_function->contains_functions)
 472 #define current_function_is_thunk (current_function->is_thunk)
 473 #define current_function_args_info (current_function->args_info)
 474 #define current_function_args_size (current_function->args_size)
 475 #define current_function_pretend_args_size (current_function->pretend_args_size)
 476 #define current_function_outgoing_args_size (current_function->outgoing_args_size)
 477 #define current_function_arg_offset_rtx (current_function->arg_offset_rtx)
 478 #define current_function_varargs (current_function->varargs)
 479 #define current_function_stdarg (current_function->stdarg)
 480 #define current_function_internal_arg_pointer (current_function->internal_arg_pointer)
 481 #define current_function_return_rtx (current_function->return_rtx)
 482 #define current_function_instrument_entry_exit (current_function->instrument_entry_exit)
 483 #define current_function_check_memory_usage (current_function->check_memory_usage)
 484 #define current_function_uses_pic_offset_table (current_function->uses_pic_offset_table)
 485 #define current_function_uses_const_pool (current_function->uses_const_pool)
 486 #define current_function_cannot_inline (current_function->cannot_inline)
 487 #define current_function_epilogue_delay_list (current_function->epilogue_delay_list)
 488 #define current_function_has_nonlocal_label (current_function->has_nonlocal_label)
 489 #define current_function_has_nonlocal_goto (current_function->has_nonlocal_goto)
 490
 491 #define max_parm_reg (current_function->x_max_parm_reg)
 492 #define parm_reg_stack_loc (current_function->x_parm_reg_stack_loc)
 493 #define cleanup_label (current_function->x_cleanup_label)
 494 #define return_label (current_function->x_return_label)
 495 #define save_expr_regs (current_function->x_save_expr_regs)
 496 #define stack_slot_list (current_function->x_stack_slot_list)
 497 #define parm_birth_insn (current_function->x_parm_birth_insn)
 498 #define frame_offset (current_function->x_frame_offset)
 499 #define tail_recursion_label (current_function->x_tail_recursion_label)
 500 #define tail_recursion_reentry (current_function->x_tail_recursion_reentry)
 501 #define arg_pointer_save_area (current_function->x_arg_pointer_save_area)
 502 #define rtl_expr_chain (current_function->x_rtl_expr_chain)
 503 #define last_parm_insn (current_function->x_last_parm_insn)
 504 #define context_display (current_function->x_context_display)
 505 #define trampoline_list (current_function->x_trampoline_list)
 506 #define function_call_count (current_function->x_function_call_count)
 507 #define temp_slots (current_function->x_temp_slots)
 508 #define temp_slot_level (current_function->x_temp_slot_level)
 509 #define target_temp_slot_level (current_function->x_target_temp_slot_level)
 510 #define var_temp_slot_level (current_function->x_var_temp_slot_level)
 511 #define nonlocal_labels (current_function->x_nonlocal_labels)
 512 #define nonlocal_goto_handler_slots (current_function->x_nonlocal_goto_handler_slots)
 513 #define nonlocal_goto_handler_labels (current_function->x_nonlocal_goto_handler_labels)
 514 #define nonlocal_goto_stack_level (current_function->x_nonlocal_goto_stack_level)
 515
 516 /* The FUNCTION_DECL for an inline function currently being expanded.  */
 517 extern tree inline_function_decl;
 518
 519 /* Given a function decl for a containing function,
 520    return the `struct function' for it.  */
 521 struct function *find_function_data PROTO((tree));
 522
 523 /* Pointer to chain of `struct function' for containing functions.  */
 524 extern struct function *outer_function_chain;
 525
 526 /* Put all this function's BLOCK nodes into a vector and return it.
 527    Also store in each NOTE for the beginning or end of a block
 528    the index of that block in the vector.  */
 529 extern void identify_blocks PROTO((tree, rtx));
 530 /* Insert a new BLOCK at an appropriate place in the block tree.  */
 531 extern void retrofit_block PROTO((tree, rtx));
 532
 533 /* Return size needed for stack frame based on slots so far allocated.
 534    This size counts from zero.  It is not rounded to STACK_BOUNDARY;
 535    the caller may have to do that.  */
 536 extern HOST_WIDE_INT get_frame_size     PROTO((void));
 537 /* Likewise, but for a different than the current function.  */
 538 extern HOST_WIDE_INT get_func_frame_size        PROTO((struct function *));
 539
 540 /* These variables hold pointers to functions to
 541    save and restore machine-specific data,
 542    in push_function_context and pop_function_context.  */
 543 extern void (*init_machine_status)      PROTO((struct function *));
 544 extern void (*mark_machine_status)      PROTO((struct function *));
 545 extern void (*save_machine_status)      PROTO((struct function *));
 546 extern void (*restore_machine_status)   PROTO((struct function *));
 547 extern void (*free_machine_status)      PROTO((struct function *));
 548
 549 /* Likewise, but for language-specific data.  */
 550 extern void (*init_lang_status)         PROTO((struct function *));
 551 extern void (*mark_lang_status)         PROTO((struct function *));
 552 extern void (*save_lang_status)         PROTO((struct function *));
 553 extern void (*restore_lang_status)      PROTO((struct function *));
 554 extern void (*free_lang_status)         PROTO((struct function *));
 555
 556 /* Save and restore status information for a nested function.  */
 557 extern void save_tree_status            PROTO((struct function *));
 558 extern void restore_tree_status         PROTO((struct function *));
 559 extern void restore_emit_status         PROTO((struct function *));
 560 extern void free_after_parsing          PROTO((struct function *));
 561 extern void free_after_compilation      PROTO((struct function *));
 562
 563 extern void init_varasm_status          PROTO((struct function *));
 564 extern void free_varasm_status          PROTO((struct function *));
 565 extern void free_emit_status            PROTO((struct function *));
 566 extern void free_stmt_status            PROTO((struct function *));
 567 extern void free_eh_status              PROTO((struct function *));
 568 extern void free_expr_status            PROTO((struct function *));
 569
 570 extern rtx get_first_block_beg          PROTO((void));
 571
 572 extern void init_virtual_regs           PROTO((struct emit_status *));
 573
 574 /* Called once, at initialization, to initialize function.c.  */
 575 extern void init_function_once          PROTO((void));
 576
 577 #ifdef rtx
 578 #undef rtx
 579 #endif
 580
 581 #ifdef tree
 582 #undef tree
 583 #endif