1 /* Structure for saving state for a nested function.
2 Copyright (C) 1989, 92-97, 1998 Free Software Foundation, Inc.
4 This file is part of GNU CC.
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)
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.
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. */
22 #if !defined(NULL_TREE) && !defined(tree)
23 typedef union union_node
*_function_tree
;
24 #define tree _function_tree
26 #if !defined(NULL_RTX) && !defined(rtx)
27 typedef struct rtx_def
*_function_rtx
;
28 #define rtx _function_rtx
34 enum machine_mode promoted_mode
;
36 struct var_refs_queue
*next
;
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. */
46 /* First and last insns in the chain of the saved sequence. */
48 tree sequence_rtl_expr
;
49 struct sequence_stack
*next
;
52 extern struct sequence_stack
*sequence_stack
;
54 /* Stack of single obstacks. */
56 struct simple_obstack_stack
58 struct obstack
*obstack
;
59 struct simple_obstack_stack
*next
;
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. */
68 /* Lowest label number in current function. */
69 int x_first_label_num
;
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.
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. */
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
;
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
;
90 /* INSN_UID for next insn emitted.
91 Reset to 1 for each function compiled. */
94 /* Line number and source file of the last line-number NOTE emitted.
95 This is used to avoid generating duplicates. */
97 char *x_last_filename
;
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
;
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
;
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
;
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)
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])
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
;
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.)
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
;
151 /* Nonzero means __builtin_saveregs has already been done in this function.
152 The value is the pseudoreg containing the value __builtin_saveregs
154 rtx x_saveregs_value
;
156 /* Similarly for __builtin_apply_args. */
157 rtx x_apply_args_value
;
159 /* List of labels that must never be deleted. */
162 /* Postincrements that still need to be expanded. */
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)
173 /* This structure can save all the important global and static variables
174 describing the status of the current function. */
178 struct function
*next_global
;
179 struct function
*next
;
181 struct eh_status
*eh
;
182 struct stmt_status
*stmt
;
183 struct expr_status
*expr
;
184 struct emit_status
*emit
;
186 /* For function.c. */
188 /* Name of this function. */
190 /* Points to the FUNCTION_DECL of this function. */
193 /* Number of bytes of args popped by function being compiled on its return.
194 Zero if no bytes are to be popped.
195 May affect compilation of return insn or of function epilogue. */
198 /* Nonzero if function being compiled needs to be given an address
199 where the value should be stored. */
202 /* Nonzero if function being compiled needs to
203 return the address of where it has put a structure value. */
204 int returns_pcc_struct
;
206 /* Nonzero if the current function returns a pointer type. */
209 /* Nonzero if function being compiled needs to be passed a static chain. */
212 /* Nonzero if function being compiled can call setjmp. */
215 /* Nonzero if function being compiled can call longjmp. */
218 /* Nonzero if function being compiled can call alloca,
219 either as a subroutine or builtin. */
222 /* Nonzero if function being compiled receives nonlocal gotos
223 from nested functions. */
225 int has_nonlocal_label
;
227 /* Nonzero if function being compiled has nonlocal gotos to parent
229 int has_nonlocal_goto
;
231 /* Nonzero if function being compiled contains nested functions. */
232 int contains_functions
;
234 /* Nonzero if the function being compiled issues a computed jump. */
235 int has_computed_jump
;
237 /* Nonzero if the current function is a thunk (a lightweight function that
238 just adjusts one of its arguments and forwards to another function), so
239 we should try to cut corners where we can. */
242 /* If function's args have a fixed size, this is that size, in bytes.
244 May affect compilation of return insn or of function epilogue. */
247 /* # bytes the prologue should push and pretend that the caller pushed them.
248 The prologue must do this, but only if parms can be passed in
250 int pretend_args_size
;
252 /* # of bytes of outgoing arguments. If ACCUMULATE_OUTGOING_ARGS is
253 defined, the needed space is pushed by the prologue. */
254 int outgoing_args_size
;
256 /* This is the offset from the arg pointer to the place where the first
257 anonymous arg can be found, if there is one. */
260 /* Nonzero if current function uses varargs.h or equivalent.
261 Zero for functions that use stdarg.h. */
264 /* Nonzero if current function uses stdarg.h or equivalent.
265 Zero for functions that use varargs.h. */
268 /* Quantities of various kinds of registers
269 used for the current function's args. */
270 CUMULATIVE_ARGS args_info
;
272 /* If non-zero, an RTL expression for the location at which the current
273 function returns its result. If the current function returns its
274 result in a register, current_function_return_rtx will always be
275 the hard register containing the result. */
278 /* The arg pointer hard register, or the pseudo into which it was copied. */
279 rtx internal_arg_pointer
;
281 /* Language-specific reason why the current function cannot be made
283 const char *cannot_inline
;
285 /* Nonzero if instrumentation calls for function entry and exit should be
287 int instrument_entry_exit
;
289 /* Nonzero if memory access checking be enabled in the current function. */
290 int check_memory_usage
;
292 /* Number of function calls seen so far in current function. */
293 int x_function_call_count
;
295 /* List (chain of TREE_LIST) of LABEL_DECLs for all nonlocal labels
296 (labels to which there can be nonlocal gotos from nested functions)
298 tree x_nonlocal_labels
;
300 /* List (chain of EXPR_LIST) of stack slots that hold the current handlers
301 for nonlocal gotos. There is one for every nonlocal label in the
302 function; this list matches the one in nonlocal_labels.
303 Zero when function does not have nonlocal labels. */
304 rtx x_nonlocal_goto_handler_slots
;
306 /* List (chain of EXPR_LIST) of labels heading the current handlers for
308 rtx x_nonlocal_goto_handler_labels
;
310 /* RTX for stack slot that holds the stack pointer value to restore
312 Zero when function does not have nonlocal labels. */
313 rtx x_nonlocal_goto_stack_level
;
315 /* Label that will go on parm cleanup code, if any.
316 Jumping to this label runs cleanup code for parameters, if
317 such code must be run. Following this code is the logical return
321 /* Label that will go on function epilogue.
322 Jumping to this label serves as a "return" instruction
323 on machines which require execution of the epilogue on all returns. */
326 /* List (chain of EXPR_LISTs) of pseudo-regs of SAVE_EXPRs.
327 So we can mark them all live at the end of the function, if nonopt. */
328 rtx x_save_expr_regs
;
330 /* List (chain of EXPR_LISTs) of all stack slots in this function.
331 Made for the sake of unshare_all_rtl. */
332 rtx x_stack_slot_list
;
334 /* Chain of all RTL_EXPRs that have insns in them. */
335 tree x_rtl_expr_chain
;
337 /* Label to jump back to for tail recursion, or 0 if we have
338 not yet needed one for this function. */
339 rtx x_tail_recursion_label
;
341 /* Place after which to insert the tail_recursion_label if we need one. */
342 rtx x_tail_recursion_reentry
;
344 /* Location at which to save the argument pointer if it will need to be
345 referenced. There are two cases where this is done: if nonlocal gotos
346 exist, or if vars stored at an offset from the argument pointer will be
347 needed by inner routines. */
348 rtx x_arg_pointer_save_area
;
350 /* Offset to end of allocated area of stack frame.
351 If stack grows down, this is the address of the last stack slot allocated.
352 If stack grows up, this is the address for the next slot. */
353 HOST_WIDE_INT x_frame_offset
;
355 /* List (chain of TREE_LISTs) of static chains for containing functions.
356 Each link has a FUNCTION_DECL in the TREE_PURPOSE and a reg rtx
357 in an RTL_EXPR in the TREE_VALUE. */
358 tree x_context_display
;
360 /* List (chain of TREE_LISTs) of trampolines for nested functions.
361 The trampoline sets up the static chain and jumps to the function.
362 We supply the trampoline's address when the function's address is
365 Each link has a FUNCTION_DECL in the TREE_PURPOSE and a reg rtx
366 in an RTL_EXPR in the TREE_VALUE. */
367 tree x_trampoline_list
;
369 /* Insn after which register parms and SAVE_EXPRs are born, if nonopt. */
370 rtx x_parm_birth_insn
;
372 /* Last insn of those whose job was to put parms into their nominal
374 rtx x_last_parm_insn
;
376 /* 1 + last pseudo register number possibly used for loading a copy
377 of a parameter of this function. */
380 /* Vector indexed by REGNO, containing location on stack in which
381 to put the parm which is nominally in pseudo register REGNO,
382 if we discover that that parm must go in the stack. The highest
383 element in this vector is one less than MAX_PARM_REG, above. */
384 rtx
*x_parm_reg_stack_loc
;
386 /* List of all temporaries allocated, both available and in use. */
387 struct temp_slot
*x_temp_slots
;
389 /* Current nesting level for temporaries. */
390 int x_temp_slot_level
;
392 /* Current nesting level for variables in a block. */
393 int x_var_temp_slot_level
;
395 /* When temporaries are created by TARGET_EXPRs, they are created at
396 this level of temp_slot_level, so that they can remain allocated
397 until no longer needed. CLEANUP_POINT_EXPRs define the lifetime
399 int x_target_temp_slot_level
;
401 /* This slot is initialized as 0 and is added to
402 during the nested function. */
403 struct var_refs_queue
*fixup_var_refs_queue
;
406 int all_types_permanent
;
407 struct momentary_level
*momentary_stack
;
408 char *maybepermanent_firstobj
;
409 char *temporary_firstobj
;
410 char *momentary_firstobj
;
411 char *momentary_function_firstobj
;
412 struct obstack
*current_obstack
;
413 struct obstack
*function_obstack
;
414 struct obstack
*function_maybepermanent_obstack
;
415 struct obstack
*expression_obstack
;
416 struct obstack
*saveable_obstack
;
417 struct obstack
*rtl_obstack
;
418 struct simple_obstack_stack
*inline_obstacks
;
420 /* For integrate.c. We duplicate some of the fields so that
421 save_for_inline_copying can keep two versions. */
423 struct emit_status
*inl_emit
;
424 /* This is in fact an rtvec. */
425 void *original_arg_vector
;
426 tree original_decl_initial
;
427 /* Last insn of those whose job was to put parms into their nominal
429 rtx inl_last_parm_insn
;
430 /* Highest label number in current function. */
431 int inl_max_label_num
;
433 /* Nonzero if the current function uses the constant pool. */
438 /* Nonzero if the current function uses pic_offset_table_rtx. */
439 int uses_pic_offset_table
;
440 /* tm.h can use this to store whatever it likes. */
441 struct machine_function
*machine
;
443 /* Language-specific code can use this to store whatever it likes. */
444 struct language_function
*language
;
448 /* If some insns can be deferred to the delay slots of the epilogue, the
449 delay list for them is recorded here. */
450 rtx epilogue_delay_list
;
453 struct constant_descriptor
**const_rtx_hash_table
;
454 struct pool_sym
**const_rtx_sym_hash_table
;
455 struct pool_constant
*first_pool
, *last_pool
;
457 rtx const_double_chain
;
460 extern struct function
*current_function
;
461 extern struct function
*all_functions
;
463 /* For backward compatibility... eventually these should all go away. */
464 #define current_function_name (current_function->name)
465 #define current_function_pops_args (current_function->pops_args)
466 #define current_function_returns_struct (current_function->returns_struct)
467 #define current_function_returns_pcc_struct (current_function->returns_pcc_struct)
468 #define current_function_returns_pointer (current_function->returns_pointer)
469 #define current_function_needs_context (current_function->needs_context)
470 #define current_function_calls_setjmp (current_function->calls_setjmp)
471 #define current_function_calls_alloca (current_function->calls_alloca)
472 #define current_function_calls_longjmp (current_function->calls_longjmp)
473 #define current_function_has_computed_jump (current_function->has_computed_jump)
474 #define current_function_contains_functions (current_function->contains_functions)
475 #define current_function_is_thunk (current_function->is_thunk)
476 #define current_function_args_info (current_function->args_info)
477 #define current_function_args_size (current_function->args_size)
478 #define current_function_pretend_args_size (current_function->pretend_args_size)
479 #define current_function_outgoing_args_size (current_function->outgoing_args_size)
480 #define current_function_arg_offset_rtx (current_function->arg_offset_rtx)
481 #define current_function_varargs (current_function->varargs)
482 #define current_function_stdarg (current_function->stdarg)
483 #define current_function_internal_arg_pointer (current_function->internal_arg_pointer)
484 #define current_function_return_rtx (current_function->return_rtx)
485 #define current_function_instrument_entry_exit (current_function->instrument_entry_exit)
486 #define current_function_check_memory_usage (current_function->check_memory_usage)
487 #define current_function_uses_pic_offset_table (current_function->uses_pic_offset_table)
488 #define current_function_uses_const_pool (current_function->uses_const_pool)
489 #define current_function_cannot_inline (current_function->cannot_inline)
490 #define current_function_epilogue_delay_list (current_function->epilogue_delay_list)
491 #define current_function_has_nonlocal_label (current_function->has_nonlocal_label)
492 #define current_function_has_nonlocal_goto (current_function->has_nonlocal_goto)
494 #define max_parm_reg (current_function->x_max_parm_reg)
495 #define parm_reg_stack_loc (current_function->x_parm_reg_stack_loc)
496 #define cleanup_label (current_function->x_cleanup_label)
497 #define return_label (current_function->x_return_label)
498 #define save_expr_regs (current_function->x_save_expr_regs)
499 #define stack_slot_list (current_function->x_stack_slot_list)
500 #define parm_birth_insn (current_function->x_parm_birth_insn)
501 #define frame_offset (current_function->x_frame_offset)
502 #define tail_recursion_label (current_function->x_tail_recursion_label)
503 #define tail_recursion_reentry (current_function->x_tail_recursion_reentry)
504 #define arg_pointer_save_area (current_function->x_arg_pointer_save_area)
505 #define rtl_expr_chain (current_function->x_rtl_expr_chain)
506 #define last_parm_insn (current_function->x_last_parm_insn)
507 #define context_display (current_function->x_context_display)
508 #define trampoline_list (current_function->x_trampoline_list)
509 #define function_call_count (current_function->x_function_call_count)
510 #define temp_slots (current_function->x_temp_slots)
511 #define temp_slot_level (current_function->x_temp_slot_level)
512 #define target_temp_slot_level (current_function->x_target_temp_slot_level)
513 #define var_temp_slot_level (current_function->x_var_temp_slot_level)
514 #define nonlocal_labels (current_function->x_nonlocal_labels)
515 #define nonlocal_goto_handler_slots (current_function->x_nonlocal_goto_handler_slots)
516 #define nonlocal_goto_handler_labels (current_function->x_nonlocal_goto_handler_labels)
517 #define nonlocal_goto_stack_level (current_function->x_nonlocal_goto_stack_level)
519 /* The FUNCTION_DECL for an inline function currently being expanded. */
520 extern tree inline_function_decl
;
522 /* Given a function decl for a containing function,
523 return the `struct function' for it. */
524 struct function
*find_function_data
PROTO((tree
));
526 /* Pointer to chain of `struct function' for containing functions. */
527 extern struct function
*outer_function_chain
;
529 /* Put all this function's BLOCK nodes into a vector and return it.
530 Also store in each NOTE for the beginning or end of a block
531 the index of that block in the vector. */
532 extern tree
*identify_blocks
PROTO((tree
, rtx
));
534 /* Return size needed for stack frame based on slots so far allocated.
535 This size counts from zero. It is not rounded to STACK_BOUNDARY;
536 the caller may have to do that. */
537 extern HOST_WIDE_INT get_frame_size
PROTO((void));
538 /* Likewise, but for a different than the current function. */
539 extern HOST_WIDE_INT get_func_frame_size
PROTO((struct function
*));
541 /* These variables hold pointers to functions to
542 save and restore machine-specific data,
543 in push_function_context and pop_function_context. */
544 extern void (*save_machine_status
) PROTO((struct function
*));
545 extern void (*restore_machine_status
) PROTO((struct function
*));
547 /* Likewise, but for language-specific data. */
548 extern void (*save_lang_status
) PROTO((struct function
*));
549 extern void (*restore_lang_status
) PROTO((struct function
*));
551 /* Save and restore status information for a nested function. */
552 extern void save_tree_status
PROTO((struct function
*, tree
));
553 extern void restore_tree_status
PROTO((struct function
*, tree
));
554 extern void save_varasm_status
PROTO((struct function
*, tree
));
555 extern void restore_varasm_status
PROTO((struct function
*));
556 extern void restore_emit_status
PROTO((struct function
*));
558 extern rtx get_first_block_beg
PROTO((void));
560 extern void init_virtual_regs
PROTO((struct emit_status
*));