1 /* Structure for saving state for a nested function.
2 Copyright (C) 1989, 92-99, 2000 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 (cfun->emit->x_reg_rtx_no)
119 #define seq_rtl_expr (cfun->emit->sequence_rtl_expr)
120 #define regno_reg_rtx (cfun->emit->x_regno_reg_rtx)
121 #define seq_stack (cfun->emit->sequence_stack)
123 #define REGNO_POINTER_ALIGN(REGNO) (cfun->emit->regno_pointer_align[REGNO])
124 #define REGNO_POINTER_FLAG(REGNO) (cfun->emit->regno_pointer_flag[REGNO])
128 /* Number of units that we should eventually pop off the stack.
129 These are the arguments to function calls that have already returned. */
130 int x_pending_stack_adjust
;
132 /* Under some ABIs, it is the caller's responsibility to pop arguments
133 pushed for function calls. A naive implementation would simply pop
134 the arguments immediately after each call. However, if several
135 function calls are made in a row, it is typically cheaper to pop
136 all the arguments after all of the calls are complete since a
137 single pop instruction can be used. Therefore, GCC attempts to
138 defer popping the arguments until absolutely necessary. (For
139 example, at the end of a conditional, the arguments must be popped,
140 since code outside the conditional won't know whether or not the
141 arguments need to be popped.)
143 When INHIBIT_DEFER_POP is non-zero, however, the compiler does not
144 attempt to defer pops. Instead, the stack is popped immediately
145 after each call. Rather then setting this variable directly, use
146 NO_DEFER_POP and OK_DEFER_POP. */
147 int x_inhibit_defer_pop
;
149 /* Nonzero means __builtin_saveregs has already been done in this function.
150 The value is the pseudoreg containing the value __builtin_saveregs
152 rtx x_saveregs_value
;
154 /* Similarly for __builtin_apply_args. */
155 rtx x_apply_args_value
;
157 /* List of labels that must never be deleted. */
160 /* Postincrements that still need to be expanded. */
164 #define pending_stack_adjust (cfun->expr->x_pending_stack_adjust)
165 #define inhibit_defer_pop (cfun->expr->x_inhibit_defer_pop)
166 #define saveregs_value (cfun->expr->x_saveregs_value)
167 #define apply_args_value (cfun->expr->x_apply_args_value)
168 #define forced_labels (cfun->expr->x_forced_labels)
169 #define pending_chain (cfun->expr->x_pending_chain)
171 /* This structure can save all the important global and static variables
172 describing the status of the current function. */
176 struct function
*next_global
;
177 struct function
*next
;
179 struct eh_status
*eh
;
180 struct stmt_status
*stmt
;
181 struct expr_status
*expr
;
182 struct emit_status
*emit
;
183 struct varasm_status
*varasm
;
185 /* For function.c. */
187 /* Name of this function. */
189 /* Points to the FUNCTION_DECL of this function. */
192 /* Number of bytes of args popped by function being compiled on its return.
193 Zero if no bytes are to be popped.
194 May affect compilation of return insn or of function epilogue. */
197 /* Nonzero if function being compiled needs to be given an address
198 where the value should be stored. */
201 /* Nonzero if function being compiled needs to
202 return the address of where it has put a structure value. */
203 int returns_pcc_struct
;
205 /* Nonzero if the current function returns a pointer type. */
208 /* Nonzero if function being compiled needs to be passed a static chain. */
211 /* Nonzero if function being compiled can call setjmp. */
214 /* Nonzero if function being compiled can call longjmp. */
217 /* Nonzero if function being compiled can call alloca,
218 either as a subroutine or builtin. */
221 /* Nonzero if function being compiled receives nonlocal gotos
222 from nested functions. */
224 int has_nonlocal_label
;
226 /* Nonzero if function being compiled has nonlocal gotos to parent
228 int has_nonlocal_goto
;
230 /* Nonzero if function being compiled contains nested functions. */
231 int contains_functions
;
233 /* Nonzero if the function being compiled issues a computed jump. */
234 int has_computed_jump
;
236 /* Nonzero if the current function is a thunk (a lightweight function that
237 just adjusts one of its arguments and forwards to another function), so
238 we should try to cut corners where we can. */
241 /* If function's args have a fixed size, this is that size, in bytes.
243 May affect compilation of return insn or of function epilogue. */
246 /* # bytes the prologue should push and pretend that the caller pushed them.
247 The prologue must do this, but only if parms can be passed in
249 int pretend_args_size
;
251 /* # of bytes of outgoing arguments. If ACCUMULATE_OUTGOING_ARGS is
252 defined, the needed space is pushed by the prologue. */
253 int outgoing_args_size
;
255 /* This is the offset from the arg pointer to the place where the first
256 anonymous arg can be found, if there is one. */
259 /* Nonzero if current function uses varargs.h or equivalent.
260 Zero for functions that use stdarg.h. */
263 /* Nonzero if current function uses stdarg.h or equivalent.
264 Zero for functions that use varargs.h. */
267 /* Quantities of various kinds of registers
268 used for the current function's args. */
269 CUMULATIVE_ARGS args_info
;
271 /* If non-zero, an RTL expression for the location at which the current
272 function returns its result. If the current function returns its
273 result in a register, current_function_return_rtx will always be
274 the hard register containing the result. */
277 /* The arg pointer hard register, or the pseudo into which it was copied. */
278 rtx internal_arg_pointer
;
280 /* Language-specific reason why the current function cannot be made
282 const char *cannot_inline
;
284 /* Nonzero if instrumentation calls for function entry and exit should be
286 int instrument_entry_exit
;
288 /* Nonzero if memory access checking be enabled in the current function. */
289 int check_memory_usage
;
291 /* Nonzero if stack limit checking should be enabled in the current
295 /* Number of function calls seen so far in current function. */
296 int x_function_call_count
;
298 /* Nonzero if this function is being processed in function-at-a-time
299 mode. In other words, if all tree structure for this function,
300 including the BLOCK tree is created, before RTL generation
302 int x_whole_function_mode_p
;
304 /* Nonzero if the back-end should not keep track of expressions that
305 determine the size of variable-sized objects. Normally, such
306 expressions are saved away, and then expanded when the next
307 function is started. For example, if a parameter has a
308 variable-sized type, then the size of the parameter is computed
309 when the function body is entered. However, some front-ends do
310 not desire this behavior. */
311 int x_dont_save_pending_sizes_p
;
313 /* List (chain of TREE_LIST) of LABEL_DECLs for all nonlocal labels
314 (labels to which there can be nonlocal gotos from nested functions)
316 tree x_nonlocal_labels
;
318 /* List (chain of EXPR_LIST) of stack slots that hold the current handlers
319 for nonlocal gotos. There is one for every nonlocal label in the
320 function; this list matches the one in nonlocal_labels.
321 Zero when function does not have nonlocal labels. */
322 rtx x_nonlocal_goto_handler_slots
;
324 /* List (chain of EXPR_LIST) of labels heading the current handlers for
326 rtx x_nonlocal_goto_handler_labels
;
328 /* RTX for stack slot that holds the stack pointer value to restore
330 Zero when function does not have nonlocal labels. */
331 rtx x_nonlocal_goto_stack_level
;
333 /* Label that will go on parm cleanup code, if any.
334 Jumping to this label runs cleanup code for parameters, if
335 such code must be run. Following this code is the logical return
339 /* Label that will go on function epilogue.
340 Jumping to this label serves as a "return" instruction
341 on machines which require execution of the epilogue on all returns. */
344 /* List (chain of EXPR_LISTs) of pseudo-regs of SAVE_EXPRs.
345 So we can mark them all live at the end of the function, if nonopt. */
346 rtx x_save_expr_regs
;
348 /* List (chain of EXPR_LISTs) of all stack slots in this function.
349 Made for the sake of unshare_all_rtl. */
350 rtx x_stack_slot_list
;
352 /* Chain of all RTL_EXPRs that have insns in them. */
353 tree x_rtl_expr_chain
;
355 /* Label to jump back to for tail recursion, or 0 if we have
356 not yet needed one for this function. */
357 rtx x_tail_recursion_label
;
359 /* Place after which to insert the tail_recursion_label if we need one. */
360 rtx x_tail_recursion_reentry
;
362 /* Location at which to save the argument pointer if it will need to be
363 referenced. There are two cases where this is done: if nonlocal gotos
364 exist, or if vars stored at an offset from the argument pointer will be
365 needed by inner routines. */
366 rtx x_arg_pointer_save_area
;
368 /* Offset to end of allocated area of stack frame.
369 If stack grows down, this is the address of the last stack slot allocated.
370 If stack grows up, this is the address for the next slot. */
371 HOST_WIDE_INT x_frame_offset
;
373 /* List (chain of TREE_LISTs) of static chains for containing functions.
374 Each link has a FUNCTION_DECL in the TREE_PURPOSE and a reg rtx
375 in an RTL_EXPR in the TREE_VALUE. */
376 tree x_context_display
;
378 /* List (chain of TREE_LISTs) of trampolines for nested functions.
379 The trampoline sets up the static chain and jumps to the function.
380 We supply the trampoline's address when the function's address is
383 Each link has a FUNCTION_DECL in the TREE_PURPOSE and a reg rtx
384 in an RTL_EXPR in the TREE_VALUE. */
385 tree x_trampoline_list
;
387 /* Insn after which register parms and SAVE_EXPRs are born, if nonopt. */
388 rtx x_parm_birth_insn
;
390 /* Last insn of those whose job was to put parms into their nominal
392 rtx x_last_parm_insn
;
394 /* 1 + last pseudo register number possibly used for loading a copy
395 of a parameter of this function. */
398 /* Vector indexed by REGNO, containing location on stack in which
399 to put the parm which is nominally in pseudo register REGNO,
400 if we discover that that parm must go in the stack. The highest
401 element in this vector is one less than MAX_PARM_REG, above. */
402 rtx
*x_parm_reg_stack_loc
;
404 /* List of all temporaries allocated, both available and in use. */
405 struct temp_slot
*x_temp_slots
;
407 /* Current nesting level for temporaries. */
408 int x_temp_slot_level
;
410 /* Current nesting level for variables in a block. */
411 int x_var_temp_slot_level
;
413 /* When temporaries are created by TARGET_EXPRs, they are created at
414 this level of temp_slot_level, so that they can remain allocated
415 until no longer needed. CLEANUP_POINT_EXPRs define the lifetime
417 int x_target_temp_slot_level
;
419 /* This slot is initialized as 0 and is added to
420 during the nested function. */
421 struct var_refs_queue
*fixup_var_refs_queue
;
424 int all_types_permanent
;
425 struct momentary_level
*momentary_stack
;
426 char *maybepermanent_firstobj
;
427 char *temporary_firstobj
;
428 char *momentary_firstobj
;
429 char *momentary_function_firstobj
;
430 struct obstack
*current_obstack
;
431 struct obstack
*function_obstack
;
432 struct obstack
*function_maybepermanent_obstack
;
433 struct obstack
*expression_obstack
;
434 struct obstack
*saveable_obstack
;
435 struct obstack
*rtl_obstack
;
437 /* For integrate.c. */
439 /* This is in fact an rtvec. */
440 void *original_arg_vector
;
441 tree original_decl_initial
;
442 /* Last insn of those whose job was to put parms into their nominal
444 rtx inl_last_parm_insn
;
445 /* Highest label number in current function. */
446 int inl_max_label_num
;
448 /* Nonzero if the current function uses the constant pool. */
453 /* Nonzero if the current function uses pic_offset_table_rtx. */
454 int uses_pic_offset_table
;
455 /* tm.h can use this to store whatever it likes. */
456 struct machine_function
*machine
;
457 /* The largest alignment of slot allocated on the stack. */
458 int stack_alignment_needed
;
460 /* Language-specific code can use this to store whatever it likes. */
461 struct language_function
*language
;
465 /* If some insns can be deferred to the delay slots of the epilogue, the
466 delay list for them is recorded here. */
467 rtx epilogue_delay_list
;
470 /* The function currently being compiled. */
471 extern struct function
*cfun
;
473 /* A list of all functions we have compiled so far. */
474 extern struct function
*all_functions
;
476 /* For backward compatibility... eventually these should all go away. */
477 #define current_function_name (cfun->name)
478 #define current_function_pops_args (cfun->pops_args)
479 #define current_function_returns_struct (cfun->returns_struct)
480 #define current_function_returns_pcc_struct (cfun->returns_pcc_struct)
481 #define current_function_returns_pointer (cfun->returns_pointer)
482 #define current_function_needs_context (cfun->needs_context)
483 #define current_function_calls_setjmp (cfun->calls_setjmp)
484 #define current_function_calls_alloca (cfun->calls_alloca)
485 #define current_function_calls_longjmp (cfun->calls_longjmp)
486 #define current_function_has_computed_jump (cfun->has_computed_jump)
487 #define current_function_contains_functions (cfun->contains_functions)
488 #define current_function_is_thunk (cfun->is_thunk)
489 #define current_function_args_info (cfun->args_info)
490 #define current_function_args_size (cfun->args_size)
491 #define current_function_pretend_args_size (cfun->pretend_args_size)
492 #define current_function_outgoing_args_size (cfun->outgoing_args_size)
493 #define current_function_arg_offset_rtx (cfun->arg_offset_rtx)
494 #define current_function_varargs (cfun->varargs)
495 #define current_function_stdarg (cfun->stdarg)
496 #define current_function_internal_arg_pointer (cfun->internal_arg_pointer)
497 #define current_function_return_rtx (cfun->return_rtx)
498 #define current_function_instrument_entry_exit (cfun->instrument_entry_exit)
499 #define current_function_check_memory_usage (cfun->check_memory_usage)
500 #define current_function_limit_stack (cfun->limit_stack)
501 #define current_function_uses_pic_offset_table (cfun->uses_pic_offset_table)
502 #define current_function_uses_const_pool (cfun->uses_const_pool)
503 #define current_function_cannot_inline (cfun->cannot_inline)
504 #define current_function_epilogue_delay_list (cfun->epilogue_delay_list)
505 #define current_function_has_nonlocal_label (cfun->has_nonlocal_label)
506 #define current_function_has_nonlocal_goto (cfun->has_nonlocal_goto)
508 #define max_parm_reg (cfun->x_max_parm_reg)
509 #define parm_reg_stack_loc (cfun->x_parm_reg_stack_loc)
510 #define cleanup_label (cfun->x_cleanup_label)
511 #define return_label (cfun->x_return_label)
512 #define save_expr_regs (cfun->x_save_expr_regs)
513 #define stack_slot_list (cfun->x_stack_slot_list)
514 #define parm_birth_insn (cfun->x_parm_birth_insn)
515 #define frame_offset (cfun->x_frame_offset)
516 #define tail_recursion_label (cfun->x_tail_recursion_label)
517 #define tail_recursion_reentry (cfun->x_tail_recursion_reentry)
518 #define arg_pointer_save_area (cfun->x_arg_pointer_save_area)
519 #define rtl_expr_chain (cfun->x_rtl_expr_chain)
520 #define last_parm_insn (cfun->x_last_parm_insn)
521 #define context_display (cfun->x_context_display)
522 #define trampoline_list (cfun->x_trampoline_list)
523 #define function_call_count (cfun->x_function_call_count)
524 #define temp_slots (cfun->x_temp_slots)
525 #define temp_slot_level (cfun->x_temp_slot_level)
526 #define target_temp_slot_level (cfun->x_target_temp_slot_level)
527 #define var_temp_slot_level (cfun->x_var_temp_slot_level)
528 #define nonlocal_labels (cfun->x_nonlocal_labels)
529 #define nonlocal_goto_handler_slots (cfun->x_nonlocal_goto_handler_slots)
530 #define nonlocal_goto_handler_labels (cfun->x_nonlocal_goto_handler_labels)
531 #define nonlocal_goto_stack_level (cfun->x_nonlocal_goto_stack_level)
533 /* The FUNCTION_DECL for an inline function currently being expanded. */
534 extern tree inline_function_decl
;
536 /* Given a function decl for a containing function,
537 return the `struct function' for it. */
538 struct function
*find_function_data
PARAMS ((tree
));
540 /* Pointer to chain of `struct function' for containing functions. */
541 extern struct function
*outer_function_chain
;
543 /* Put all this function's BLOCK nodes into a vector and return it.
544 Also store in each NOTE for the beginning or end of a block
545 the index of that block in the vector. */
546 extern void identify_blocks
PARAMS ((tree
, rtx
));
548 /* Return size needed for stack frame based on slots so far allocated.
549 This size counts from zero. It is not rounded to STACK_BOUNDARY;
550 the caller may have to do that. */
551 extern HOST_WIDE_INT get_frame_size
PARAMS ((void));
552 /* Likewise, but for a different than the current function. */
553 extern HOST_WIDE_INT get_func_frame_size
PARAMS ((struct function
*));
555 /* These variables hold pointers to functions to
556 save and restore machine-specific data,
557 in push_function_context and pop_function_context. */
558 extern void (*init_machine_status
) PARAMS ((struct function
*));
559 extern void (*mark_machine_status
) PARAMS ((struct function
*));
560 extern void (*save_machine_status
) PARAMS ((struct function
*));
561 extern void (*restore_machine_status
) PARAMS ((struct function
*));
562 extern void (*free_machine_status
) PARAMS ((struct function
*));
564 /* Likewise, but for language-specific data. */
565 extern void (*init_lang_status
) PARAMS ((struct function
*));
566 extern void (*mark_lang_status
) PARAMS ((struct function
*));
567 extern void (*save_lang_status
) PARAMS ((struct function
*));
568 extern void (*restore_lang_status
) PARAMS ((struct function
*));
569 extern void (*free_lang_status
) PARAMS ((struct function
*));
571 /* Save and restore status information for a nested function. */
572 extern void save_tree_status
PARAMS ((struct function
*));
573 extern void restore_tree_status
PARAMS ((struct function
*));
574 extern void restore_emit_status
PARAMS ((struct function
*));
575 extern void free_after_parsing
PARAMS ((struct function
*));
576 extern void free_after_compilation
PARAMS ((struct function
*));
578 extern void init_varasm_status
PARAMS ((struct function
*));
579 extern void free_varasm_status
PARAMS ((struct function
*));
580 extern void free_emit_status
PARAMS ((struct function
*));
581 extern void free_stmt_status
PARAMS ((struct function
*));
582 extern void free_eh_status
PARAMS ((struct function
*));
583 extern void free_expr_status
PARAMS ((struct function
*));
585 extern rtx get_first_block_beg
PARAMS ((void));
588 extern void diddle_return_value
PARAMS ((void (*)(rtx
, void*), void*));
589 extern void clobber_return_register
PARAMS ((void));
590 extern void use_return_register
PARAMS ((void));
593 extern void init_virtual_regs
PARAMS ((struct emit_status
*));
595 /* Called once, at initialization, to initialize function.c. */
596 extern void init_function_once
PARAMS ((void));