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   /* Nonzero if the back-end should not keep track of expressions that
 303      determine the size of variable-sized objects.  Normally, such
 304      expressions are saved away, and then expanded when the next
 305      function is started.  For example, if a parameter has a
 306      variable-sized type, then the size of the parameter is computed
 307      when the function body is entered.  However, some front-ends do
 308      not desire this behavior.  */
 309   int x_dont_save_pending_sizes_p;
 310
 311   /* List (chain of TREE_LIST) of LABEL_DECLs for all nonlocal labels
 312      (labels to which there can be nonlocal gotos from nested functions)
 313      in this function.  */
 314   tree x_nonlocal_labels;
 315
 316   /* List (chain of EXPR_LIST) of stack slots that hold the current handlers
 317      for nonlocal gotos.  There is one for every nonlocal label in the
 318      function; this list matches the one in nonlocal_labels.
 319      Zero when function does not have nonlocal labels.  */
 320   rtx x_nonlocal_goto_handler_slots;
 321
 322   /* List (chain of EXPR_LIST) of labels heading the current handlers for
 323      nonlocal gotos.  */
 324   rtx x_nonlocal_goto_handler_labels;
 325
 326   /* RTX for stack slot that holds the stack pointer value to restore
 327      for a nonlocal goto.
 328      Zero when function does not have nonlocal labels.  */
 329   rtx x_nonlocal_goto_stack_level;
 330
 331   /* Label that will go on parm cleanup code, if any.
 332      Jumping to this label runs cleanup code for parameters, if
 333      such code must be run.  Following this code is the logical return
 334      label.  */
 335   rtx x_cleanup_label;
 336
 337   /* Label that will go on function epilogue.
 338      Jumping to this label serves as a "return" instruction
 339      on machines which require execution of the epilogue on all returns.  */
 340   rtx x_return_label;
 341
 342   /* List (chain of EXPR_LISTs) of pseudo-regs of SAVE_EXPRs.
 343      So we can mark them all live at the end of the function, if nonopt.  */
 344   rtx x_save_expr_regs;
 345
 346   /* List (chain of EXPR_LISTs) of all stack slots in this function.
 347      Made for the sake of unshare_all_rtl.  */
 348   rtx x_stack_slot_list;
 349
 350   /* Chain of all RTL_EXPRs that have insns in them.  */
 351   tree x_rtl_expr_chain;
 352
 353   /* Label to jump back to for tail recursion, or 0 if we have
 354      not yet needed one for this function.  */
 355   rtx x_tail_recursion_label;
 356
 357   /* Place after which to insert the tail_recursion_label if we need one.  */
 358   rtx x_tail_recursion_reentry;
 359
 360   /* Location at which to save the argument pointer if it will need to be
 361      referenced.  There are two cases where this is done: if nonlocal gotos
 362      exist, or if vars stored at an offset from the argument pointer will be
 363      needed by inner routines.  */
 364   rtx x_arg_pointer_save_area;
 365
 366   /* Offset to end of allocated area of stack frame.
 367      If stack grows down, this is the address of the last stack slot allocated.
 368      If stack grows up, this is the address for the next slot.  */
 369   HOST_WIDE_INT x_frame_offset;
 370
 371   /* List (chain of TREE_LISTs) of static chains for containing functions.
 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_context_display;
 375
 376   /* List (chain of TREE_LISTs) of trampolines for nested functions.
 377      The trampoline sets up the static chain and jumps to the function.
 378      We supply the trampoline's address when the function's address is
 379      requested.
 380
 381      Each link has a FUNCTION_DECL in the TREE_PURPOSE and a reg rtx
 382      in an RTL_EXPR in the TREE_VALUE.  */
 383   tree x_trampoline_list;
 384
 385   /* Insn after which register parms and SAVE_EXPRs are born, if nonopt.  */
 386   rtx x_parm_birth_insn;
 387
 388   /* Last insn of those whose job was to put parms into their nominal
 389      homes.  */
 390   rtx x_last_parm_insn;
 391
 392   /* 1 + last pseudo register number possibly used for loading a copy
 393      of a parameter of this function. */
 394   int x_max_parm_reg;
 395
 396   /* Vector indexed by REGNO, containing location on stack in which
 397      to put the parm which is nominally in pseudo register REGNO,
 398      if we discover that that parm must go in the stack.  The highest
 399      element in this vector is one less than MAX_PARM_REG, above.  */
 400   rtx *x_parm_reg_stack_loc;
 401
 402   /* List of all temporaries allocated, both available and in use.  */
 403   struct temp_slot *x_temp_slots;
 404
 405   /* Current nesting level for temporaries.  */
 406   int x_temp_slot_level;
 407
 408   /* Current nesting level for variables in a block.  */
 409   int x_var_temp_slot_level;
 410
 411   /* When temporaries are created by TARGET_EXPRs, they are created at
 412      this level of temp_slot_level, so that they can remain allocated
 413      until no longer needed.  CLEANUP_POINT_EXPRs define the lifetime
 414      of TARGET_EXPRs.  */
 415   int x_target_temp_slot_level;
 416
 417   /* This slot is initialized as 0 and is added to
 418      during the nested function.  */
 419   struct var_refs_queue *fixup_var_refs_queue;
 420
 421   /* For tree.c.  */
 422   int all_types_permanent;
 423   struct momentary_level *momentary_stack;
 424   char *maybepermanent_firstobj;
 425   char *temporary_firstobj;
 426   char *momentary_firstobj;
 427   char *momentary_function_firstobj;
 428   struct obstack *current_obstack;
 429   struct obstack *function_obstack;
 430   struct obstack *function_maybepermanent_obstack;
 431   struct obstack *expression_obstack;
 432   struct obstack *saveable_obstack;
 433   struct obstack *rtl_obstack;
 434
 435   /* For integrate.c.  */
 436   int inlinable;
 437   /* This is in fact an rtvec.  */
 438   void *original_arg_vector;
 439   tree original_decl_initial;
 440   /* Last insn of those whose job was to put parms into their nominal
 441      homes.  */
 442   rtx inl_last_parm_insn;
 443   /* Highest label number in current function.  */
 444   int inl_max_label_num;
 445
 446   /* Nonzero if the current function uses the constant pool.  */
 447   int uses_const_pool;
 448
 449   /* For md files.  */
 450
 451   /* Nonzero if the current function uses pic_offset_table_rtx.  */
 452   int uses_pic_offset_table;
 453   /* tm.h can use this to store whatever it likes.  */
 454   struct machine_function *machine;
 455
 456   /* Language-specific code can use this to store whatever it likes.  */
 457   struct language_function *language;
 458
 459   /* For reorg.  */
 460
 461   /* If some insns can be deferred to the delay slots of the epilogue, the
 462      delay list for them is recorded here.  */
 463   rtx epilogue_delay_list;
 464 };
 465
 466 extern struct function *current_function;
 467 extern struct function *all_functions;
 468
 469 /* For backward compatibility... eventually these should all go away.  */
 470 #define current_function_name (current_function->name)
 471 #define current_function_pops_args (current_function->pops_args)
 472 #define current_function_returns_struct (current_function->returns_struct)
 473 #define current_function_returns_pcc_struct (current_function->returns_pcc_struct)
 474 #define current_function_returns_pointer (current_function->returns_pointer)
 475 #define current_function_needs_context (current_function->needs_context)
 476 #define current_function_calls_setjmp (current_function->calls_setjmp)
 477 #define current_function_calls_alloca (current_function->calls_alloca)
 478 #define current_function_calls_longjmp (current_function->calls_longjmp)
 479 #define current_function_has_computed_jump (current_function->has_computed_jump)
 480 #define current_function_contains_functions (current_function->contains_functions)
 481 #define current_function_is_thunk (current_function->is_thunk)
 482 #define current_function_args_info (current_function->args_info)
 483 #define current_function_args_size (current_function->args_size)
 484 #define current_function_pretend_args_size (current_function->pretend_args_size)
 485 #define current_function_outgoing_args_size (current_function->outgoing_args_size)
 486 #define current_function_arg_offset_rtx (current_function->arg_offset_rtx)
 487 #define current_function_varargs (current_function->varargs)
 488 #define current_function_stdarg (current_function->stdarg)
 489 #define current_function_internal_arg_pointer (current_function->internal_arg_pointer)
 490 #define current_function_return_rtx (current_function->return_rtx)
 491 #define current_function_instrument_entry_exit (current_function->instrument_entry_exit)
 492 #define current_function_check_memory_usage (current_function->check_memory_usage)
 493 #define current_function_uses_pic_offset_table (current_function->uses_pic_offset_table)
 494 #define current_function_uses_const_pool (current_function->uses_const_pool)
 495 #define current_function_cannot_inline (current_function->cannot_inline)
 496 #define current_function_epilogue_delay_list (current_function->epilogue_delay_list)
 497 #define current_function_has_nonlocal_label (current_function->has_nonlocal_label)
 498 #define current_function_has_nonlocal_goto (current_function->has_nonlocal_goto)
 499
 500 #define max_parm_reg (current_function->x_max_parm_reg)
 501 #define parm_reg_stack_loc (current_function->x_parm_reg_stack_loc)
 502 #define cleanup_label (current_function->x_cleanup_label)
 503 #define return_label (current_function->x_return_label)
 504 #define save_expr_regs (current_function->x_save_expr_regs)
 505 #define stack_slot_list (current_function->x_stack_slot_list)
 506 #define parm_birth_insn (current_function->x_parm_birth_insn)
 507 #define frame_offset (current_function->x_frame_offset)
 508 #define tail_recursion_label (current_function->x_tail_recursion_label)
 509 #define tail_recursion_reentry (current_function->x_tail_recursion_reentry)
 510 #define arg_pointer_save_area (current_function->x_arg_pointer_save_area)
 511 #define rtl_expr_chain (current_function->x_rtl_expr_chain)
 512 #define last_parm_insn (current_function->x_last_parm_insn)
 513 #define context_display (current_function->x_context_display)
 514 #define trampoline_list (current_function->x_trampoline_list)
 515 #define function_call_count (current_function->x_function_call_count)
 516 #define temp_slots (current_function->x_temp_slots)
 517 #define temp_slot_level (current_function->x_temp_slot_level)
 518 #define target_temp_slot_level (current_function->x_target_temp_slot_level)
 519 #define var_temp_slot_level (current_function->x_var_temp_slot_level)
 520 #define nonlocal_labels (current_function->x_nonlocal_labels)
 521 #define nonlocal_goto_handler_slots (current_function->x_nonlocal_goto_handler_slots)
 522 #define nonlocal_goto_handler_labels (current_function->x_nonlocal_goto_handler_labels)
 523 #define nonlocal_goto_stack_level (current_function->x_nonlocal_goto_stack_level)
 524
 525 /* The FUNCTION_DECL for an inline function currently being expanded.  */
 526 extern tree inline_function_decl;
 527
 528 /* Given a function decl for a containing function,
 529    return the `struct function' for it.  */
 530 struct function *find_function_data PROTO((tree));
 531
 532 /* Pointer to chain of `struct function' for containing functions.  */
 533 extern struct function *outer_function_chain;
 534
 535 /* Put all this function's BLOCK nodes into a vector and return it.
 536    Also store in each NOTE for the beginning or end of a block
 537    the index of that block in the vector.  */
 538 extern void identify_blocks PROTO((tree, rtx));
 539 /* Insert a new BLOCK at an appropriate place in the block tree.  */
 540 extern void retrofit_block PROTO((tree, rtx));
 541
 542 /* Return size needed for stack frame based on slots so far allocated.
 543    This size counts from zero.  It is not rounded to STACK_BOUNDARY;
 544    the caller may have to do that.  */
 545 extern HOST_WIDE_INT get_frame_size     PROTO((void));
 546 /* Likewise, but for a different than the current function.  */
 547 extern HOST_WIDE_INT get_func_frame_size        PROTO((struct function *));
 548
 549 /* These variables hold pointers to functions to
 550    save and restore machine-specific data,
 551    in push_function_context and pop_function_context.  */
 552 extern void (*init_machine_status)      PROTO((struct function *));
 553 extern void (*mark_machine_status)      PROTO((struct function *));
 554 extern void (*save_machine_status)      PROTO((struct function *));
 555 extern void (*restore_machine_status)   PROTO((struct function *));
 556 extern void (*free_machine_status)      PROTO((struct function *));
 557
 558 /* Likewise, but for language-specific data.  */
 559 extern void (*init_lang_status)         PROTO((struct function *));
 560 extern void (*mark_lang_status)         PROTO((struct function *));
 561 extern void (*save_lang_status)         PROTO((struct function *));
 562 extern void (*restore_lang_status)      PROTO((struct function *));
 563 extern void (*free_lang_status)         PROTO((struct function *));
 564
 565 /* Save and restore status information for a nested function.  */
 566 extern void save_tree_status            PROTO((struct function *));
 567 extern void restore_tree_status         PROTO((struct function *));
 568 extern void restore_emit_status         PROTO((struct function *));
 569 extern void free_after_parsing          PROTO((struct function *));
 570 extern void free_after_compilation      PROTO((struct function *));
 571
 572 extern void init_varasm_status          PROTO((struct function *));
 573 extern void free_varasm_status          PROTO((struct function *));
 574 extern void free_emit_status            PROTO((struct function *));
 575 extern void free_stmt_status            PROTO((struct function *));
 576 extern void free_eh_status              PROTO((struct function *));
 577 extern void free_expr_status            PROTO((struct function *));
 578
 579 extern rtx get_first_block_beg          PROTO((void));
 580
 581 extern void init_virtual_regs           PROTO((struct emit_status *));
 582
 583 /* Called once, at initialization, to initialize function.c.  */
 584 extern void init_function_once          PROTO((void));
 585
 586 #ifdef rtx
 587 #undef rtx
 588 #endif
 589
 590 #ifdef tree
 591 #undef tree
 592 #endif