[thirdparty/gcc.git] / gcc / ggc.h

/* Garbage collection for the GNU compiler.
   Copyright (C) 1998, 1999, 2000, 2001 Free Software Foundation, Inc.

This file is part of GCC.

GCC is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
Software Foundation; either version 2, or (at your option) any later
version.

GCC is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
for more details.

You should have received a copy of the GNU General Public License
along with GCC; see the file COPYING.  If not, write to the Free
Software Foundation, 59 Temple Place - Suite 330, Boston, MA
02111-1307, USA.  */

#include "varray.h"

/* Symbols are marked with `ggc' for `gcc gc' so as not to interfere with
   an external gc library that might be linked in.  */

/* These structures are defined in various headers throughout the
   compiler.  However, rather than force everyone who includes this
   header to include all the headers in which they are declared, we
   just forward-declare them here.  */
struct eh_status;
struct emit_status;
struct expr_status;
struct hash_table;
struct label_node;
struct rtx_def;
struct rtvec_def;
struct stmt_status;
union  tree_node;
struct varasm_status;

/* Constants for general use.  */
extern const char empty_string[];	/* empty string */
extern const char digit_vector[];	/* "0" .. "9" */
#define digit_string(d) (digit_vector + ((d) * 2))

/* Trees that have been marked, but whose children still need marking.  */
extern varray_type ggc_pending_trees;

/* Manipulate global roots that are needed between calls to gc.  */
void ggc_add_root PARAMS ((void *base, int nelt, int size, void (*)(void *)));
void ggc_add_rtx_root PARAMS ((struct rtx_def **, int nelt));
void ggc_add_tree_root PARAMS ((union tree_node **, int nelt));
void ggc_add_rtx_varray_root PARAMS ((struct varray_head_tag **, int nelt));
void ggc_add_tree_varray_root PARAMS ((struct varray_head_tag **, int nelt));
void ggc_add_tree_hash_table_root PARAMS ((struct hash_table **, int nelt));
void ggc_del_root PARAMS ((void *base));

/* Mark nodes from the gc_add_root callback.  These functions follow
   pointers to mark other objects too.  */
extern void ggc_mark_rtx_varray PARAMS ((struct varray_head_tag *));
extern void ggc_mark_tree_varray PARAMS ((struct varray_head_tag *));
extern void ggc_mark_tree_hash_table PARAMS ((struct hash_table *));
extern void ggc_mark_roots PARAMS ((void));

extern void ggc_mark_rtx_children PARAMS ((struct rtx_def *));
extern void ggc_mark_rtvec_children PARAMS ((struct rtvec_def *));

/* If EXPR is not NULL and previously unmarked, mark it and evaluate
   to true.  Otherwise evaluate to false.  */
#define ggc_test_and_set_mark(EXPR) \
  ((EXPR) != NULL && ! ggc_set_mark (EXPR))

#define ggc_mark_rtx(EXPR)                      \
  do {                                          \
    rtx r__ = (EXPR);                           \
    if (ggc_test_and_set_mark (r__))            \
      ggc_mark_rtx_children (r__);              \
  } while (0)

#define ggc_mark_tree(EXPR)				\
  do {							\
    tree t__ = (EXPR);					\
    if (ggc_test_and_set_mark (t__))			\
      VARRAY_PUSH_TREE (ggc_pending_trees, t__);	\
  } while (0)

#define ggc_mark_nonnull_tree(EXPR)			\
  do {							\
    tree t__ = (EXPR);					\
    if (! ggc_set_mark (t__))				\
      VARRAY_PUSH_TREE (ggc_pending_trees, t__);	\
  } while (0)

#define ggc_mark_rtvec(EXPR)                    \
  do {                                          \
    rtvec v__ = (EXPR);                         \
    if (ggc_test_and_set_mark (v__))            \
      ggc_mark_rtvec_children (v__);            \
  } while (0)

#define ggc_mark(EXPR)				\
  do {						\
    const void *a__ = (EXPR);			\
    if (a__ != NULL)				\
      ggc_set_mark (a__);			\
  } while (0)

/* A GC implementation must provide these functions.  */

/* Initialize the garbage collector.   */
extern void init_ggc PARAMS ((void));
extern void init_stringpool PARAMS ((void));

/* Start a new GGC context.  Memory allocated in previous contexts
   will not be collected while the new context is active.  */
extern void ggc_push_context PARAMS ((void));

/* Finish a GC context.  Any uncollected memory in the new context
   will be merged with the old context.  */
extern void ggc_pop_context PARAMS ((void));

/* Allocation.  */

/* The internal primitive.  */
void *ggc_alloc PARAMS ((size_t));
/* Like ggc_alloc, but allocates cleared memory.  */
void *ggc_alloc_cleared PARAMS ((size_t));

#define ggc_alloc_rtx(NSLOTS)						  \
  ((struct rtx_def *) ggc_alloc (sizeof (struct rtx_def)		  \
				 + ((NSLOTS) - 1) * sizeof (rtunion)))

#define ggc_alloc_rtvec(NELT)						  \
  ((struct rtvec_def *) ggc_alloc (sizeof (struct rtvec_def)		  \
				   + ((NELT) - 1) * sizeof (rtx)))

#define ggc_alloc_tree(LENGTH) ((union tree_node *) ggc_alloc (LENGTH))

/* Allocate a gc-able string, and fill it with LENGTH bytes from CONTENTS.
   If LENGTH is -1, then CONTENTS is assumed to be a
   null-terminated string and the memory sized accordingly.  */
const char *ggc_alloc_string PARAMS ((const char *contents, int length));

/* Make a copy of S, in GC-able memory.  */
#define ggc_strdup(S) ggc_alloc_string((S), -1)

/* Invoke the collector.  Garbage collection occurs only when this
   function is called, not during allocations.  */
void ggc_collect PARAMS ((void));

/* Actually set the mark on a particular region of memory, but don't
   follow pointers.  This function is called by ggc_mark_*.  It
   returns zero if the object was not previously marked; non-zero if
   the object was already marked, or if, for any other reason,
   pointers in this data structure should not be traversed.  */
int ggc_set_mark PARAMS ((const void *));

/* Callbacks to the languages.  */

/* This is the language's opportunity to mark nodes held through
   the lang_specific hooks in the tree.  */
void lang_mark_tree PARAMS ((union tree_node *));

/* The FALSE_LABEL_STACK, declared in except.h, has language-dependent
   semantics.  If a front-end needs to mark the false label stack, it
   should set this pointer to a non-NULL value.  Otherwise, no marking
   will be done.  */
extern void (*lang_mark_false_label_stack) PARAMS ((struct label_node *));

/* Mark functions for various structs scattered about.  */

void mark_eh_status PARAMS ((struct eh_status *));
void mark_emit_status PARAMS ((struct emit_status *));
void mark_expr_status PARAMS ((struct expr_status *));
void mark_stmt_status PARAMS ((struct stmt_status *));
void mark_varasm_status PARAMS ((struct varasm_status *));
void mark_optab PARAMS ((void *));

/* Statistics.  */

/* This structure contains the statistics common to all collectors.
   Particular collectors can extend this structure.  */
typedef struct ggc_statistics 
{
  /* The Ith element is the number of nodes allocated with code I.  */
  unsigned num_trees[256];
  /* The Ith element is the number of bytes allocated by nodes with 
     code I.  */
  size_t size_trees[256];
  /* The Ith element is the number of nodes allocated with code I.  */
  unsigned num_rtxs[256];
  /* The Ith element is the number of bytes allocated by nodes with 
     code I.  */
  size_t size_rtxs[256];
  /* The total size of the tree nodes allocated.  */
  size_t total_size_trees;
  /* The total size of the RTL nodes allocated.  */
  size_t total_size_rtxs;
  /* The total number of tree nodes allocated.  */
  unsigned total_num_trees;
  /* The total number of RTL nodes allocated.  */
  unsigned total_num_rtxs;
} ggc_statistics;

/* Return the number of bytes allocated at the indicated address.  */
size_t ggc_get_size PARAMS ((const void *));

/* Used by the various collectors to gather and print statistics that
   do not depend on the collector in use.  */
void ggc_print_common_statistics PARAMS ((FILE *, ggc_statistics *));

/* Print allocation statistics.  */
extern void ggc_print_statistics PARAMS ((void));
void stringpool_statistics PARAMS ((void));
Commit	Line	Data
05513b45	1	/* Garbage collection for the GNU compiler.
3915b59e	2	Copyright (C) 1998, 1999, 2000, 2001 Free Software Foundation, Inc.
05513b45	3
f12b58b3	4	This file is part of GCC.
02e7a332	5
f12b58b3	6	GCC is free software; you can redistribute it and/or modify it under
	7	the terms of the GNU General Public License as published by the Free
	8	Software Foundation; either version 2, or (at your option) any later
	9	version.
02e7a332	10
f12b58b3	11	GCC is distributed in the hope that it will be useful, but WITHOUT ANY
f12b58b3	12	WARRANTY; without even the implied warranty of MERCHANTABILITY or
02e7a332	13	FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
	14	for more details.
	15
	16	You should have received a copy of the GNU General Public License
f12b58b3	17	along with GCC; see the file COPYING. If not, write to the Free
02e7a332	18	Software Foundation, 59 Temple Place - Suite 330, Boston, MA
02e7a332	19	02111-1307, USA. */
05513b45	20
769177ac	21	#include "varray.h"
05513b45	22
	23	/* Symbols are marked with `ggc' for `gcc gc' so as not to interfere with
	24	an external gc library that might be linked in. */
	25
a7b0c170	26	/* These structures are defined in various headers throughout the
	27	compiler. However, rather than force everyone who includes this
	28	header to include all the headers in which they are declared, we
	29	just forward-declare them here. */
a7b0c170	30	struct eh_status;
a7b0c170	31	struct emit_status;
3c3bb268	32	struct expr_status;
bebb7b68	33	struct hash_table;
bebb7b68	34	struct label_node;
40977116	35	struct rtx_def;
bebb7b68	36	struct rtvec_def;
a7b0c170	37	struct stmt_status;
bebb7b68	38	union tree_node;
a7b0c170	39	struct varasm_status;
a7b0c170	40
0f4dbfb9	41	/* Constants for general use. */
ec6cb94a	42	extern const char empty_string[]; /* empty string */
	43	extern const char digit_vector[]; /* "0" .. "9" */
	44	#define digit_string(d) (digit_vector + ((d) * 2))
0f4dbfb9	45
769177ac	46	/* Trees that have been marked, but whose children still need marking. */
	47	extern varray_type ggc_pending_trees;
	48
bebb7b68	49	/* Manipulate global roots that are needed between calls to gc. */
38b9004f	50	void ggc_add_root PARAMS ((void base, int nelt, int size, void ()(void *)));
	51	void ggc_add_rtx_root PARAMS ((struct rtx_def **, int nelt));
	52	void ggc_add_tree_root PARAMS ((union tree_node **, int nelt));
cf6cce73	53	void ggc_add_rtx_varray_root PARAMS ((struct varray_head_tag **, int nelt));
38b9004f	54	void ggc_add_tree_varray_root PARAMS ((struct varray_head_tag **, int nelt));
	55	void ggc_add_tree_hash_table_root PARAMS ((struct hash_table **, int nelt));
	56	void ggc_del_root PARAMS ((void *base));
05513b45	57
bebb7b68	58	/* Mark nodes from the gc_add_root callback. These functions follow
bebb7b68	59	pointers to mark other objects too. */
cf6cce73	60	extern void ggc_mark_rtx_varray PARAMS ((struct varray_head_tag *));
38b9004f	61	extern void ggc_mark_tree_varray PARAMS ((struct varray_head_tag *));
	62	extern void ggc_mark_tree_hash_table PARAMS ((struct hash_table *));
	63	extern void ggc_mark_roots PARAMS ((void));
0046a2c2	64
38b9004f	65	extern void ggc_mark_rtx_children PARAMS ((struct rtx_def *));
38b9004f	66	extern void ggc_mark_rtvec_children PARAMS ((struct rtvec_def *));
0046a2c2	67
f7cb0e39	68	/* If EXPR is not NULL and previously unmarked, mark it and evaluate
	69	to true. Otherwise evaluate to false. */
	70	#define ggc_test_and_set_mark(EXPR) \
	71	((EXPR) != NULL && ! ggc_set_mark (EXPR))
	72
	73	#define ggc_mark_rtx(EXPR) \
	74	do { \
	75	rtx r__ = (EXPR); \
	76	if (ggc_test_and_set_mark (r__)) \
	77	ggc_mark_rtx_children (r__); \
71661611	78	} while (0)
71661611	79
769177ac	80	#define ggc_mark_tree(EXPR) \
	81	do { \
	82	tree t__ = (EXPR); \
	83	if (ggc_test_and_set_mark (t__)) \
	84	VARRAY_PUSH_TREE (ggc_pending_trees, t__); \
71661611	85	} while (0)
e3691812	86
0d086e18	87	#define ggc_mark_nonnull_tree(EXPR) \
	88	do { \
	89	tree t__ = (EXPR); \
	90	if (! ggc_set_mark (t__)) \
	91	VARRAY_PUSH_TREE (ggc_pending_trees, t__); \
	92	} while (0)
	93
f7cb0e39	94	#define ggc_mark_rtvec(EXPR) \
	95	do { \
	96	rtvec v__ = (EXPR); \
	97	if (ggc_test_and_set_mark (v__)) \
	98	ggc_mark_rtvec_children (v__); \
0046a2c2	99	} while (0)
0046a2c2	100
71661611	101	#define ggc_mark(EXPR) \
71661611	102	do { \
9a356c3c	103	const void *a__ = (EXPR); \
71661611	104	if (a__ != NULL) \
	105	ggc_set_mark (a__); \
	106	} while (0)
	107
bebb7b68	108	/* A GC implementation must provide these functions. */
	109
	110	/* Initialize the garbage collector. */
38b9004f	111	extern void init_ggc PARAMS ((void));
44acf429	112	extern void init_stringpool PARAMS ((void));
05513b45	113
c788feb1	114	/* Start a new GGC context. Memory allocated in previous contexts
c788feb1	115	will not be collected while the new context is active. */
38b9004f	116	extern void ggc_push_context PARAMS ((void));
bebb7b68	117
c788feb1	118	/* Finish a GC context. Any uncollected memory in the new context
c788feb1	119	will be merged with the old context. */
38b9004f	120	extern void ggc_pop_context PARAMS ((void));
c788feb1	121
05513b45	122	/* Allocation. */
71661611	123
71661611	124	/* The internal primitive. */
791ceafe	125	void *ggc_alloc PARAMS ((size_t));
	126	/* Like ggc_alloc, but allocates cleared memory. */
	127	void *ggc_alloc_cleared PARAMS ((size_t));
71661611	128
791ceafe	129	#define ggc_alloc_rtx(NSLOTS) \
	130	((struct rtx_def *) ggc_alloc (sizeof (struct rtx_def) \
	131	+ ((NSLOTS) - 1) * sizeof (rtunion)))
71661611	132
71661611	133	#define ggc_alloc_rtvec(NELT) \
791ceafe	134	((struct rtvec_def *) ggc_alloc (sizeof (struct rtvec_def) \
791ceafe	135	+ ((NELT) - 1) * sizeof (rtx)))
71661611	136
791ceafe	137	#define ggc_alloc_tree(LENGTH) ((union tree_node *) ggc_alloc (LENGTH))
71661611	138
44acf429	139	/* Allocate a gc-able string, and fill it with LENGTH bytes from CONTENTS.
	140	If LENGTH is -1, then CONTENTS is assumed to be a
	141	null-terminated string and the memory sized accordingly. */
	142	const char ggc_alloc_string PARAMS ((const char contents, int length));
05513b45	143
a4e59c31	144	/* Make a copy of S, in GC-able memory. */
	145	#define ggc_strdup(S) ggc_alloc_string((S), -1)
	146
3915b59e	147	/* Invoke the collector. Garbage collection occurs only when this
3915b59e	148	function is called, not during allocations. */
38b9004f	149	void ggc_collect PARAMS ((void));
05513b45	150
bebb7b68	151	/* Actually set the mark on a particular region of memory, but don't
71661611	152	follow pointers. This function is called by ggc_mark_*. It
	153	returns zero if the object was not previously marked; non-zero if
	154	the object was already marked, or if, for any other reason,
	155	pointers in this data structure should not be traversed. */
9a356c3c	156	int ggc_set_mark PARAMS ((const void *));
05513b45	157
05513b45	158	/* Callbacks to the languages. */
	159
	160	/* This is the language's opportunity to mark nodes held through
	161	the lang_specific hooks in the tree. */
38b9004f	162	void lang_mark_tree PARAMS ((union tree_node *));
05513b45	163
a4e59c31	164	/* The FALSE_LABEL_STACK, declared in except.h, has language-dependent
	165	semantics. If a front-end needs to mark the false label stack, it
	166	should set this pointer to a non-NULL value. Otherwise, no marking
	167	will be done. */
	168	extern void (lang_mark_false_label_stack) PARAMS ((struct label_node ));
a7b0c170	169
05513b45	170	/* Mark functions for various structs scattered about. */
05513b45	171
38b9004f	172	void mark_eh_status PARAMS ((struct eh_status *));
	173	void mark_emit_status PARAMS ((struct emit_status *));
	174	void mark_expr_status PARAMS ((struct expr_status *));
	175	void mark_stmt_status PARAMS ((struct stmt_status *));
	176	void mark_varasm_status PARAMS ((struct varasm_status *));
	177	void mark_optab PARAMS ((void *));
4e00b6fd	178
	179	/* Statistics. */
	180
	181	/* This structure contains the statistics common to all collectors.
	182	Particular collectors can extend this structure. */
	183	typedef struct ggc_statistics
	184	{
	185	/* The Ith element is the number of nodes allocated with code I. */
	186	unsigned num_trees[256];
	187	/* The Ith element is the number of bytes allocated by nodes with
	188	code I. */
	189	size_t size_trees[256];
	190	/* The Ith element is the number of nodes allocated with code I. */
	191	unsigned num_rtxs[256];
	192	/* The Ith element is the number of bytes allocated by nodes with
	193	code I. */
	194	size_t size_rtxs[256];
4e00b6fd	195	/* The total size of the tree nodes allocated. */
4e00b6fd	196	size_t total_size_trees;
4e00b6fd	197	/* The total size of the RTL nodes allocated. */
4e00b6fd	198	size_t total_size_rtxs;
9ffd5d6d	199	/* The total number of tree nodes allocated. */
	200	unsigned total_num_trees;
	201	/* The total number of RTL nodes allocated. */
	202	unsigned total_num_rtxs;
4e00b6fd	203	} ggc_statistics;
	204
	205	/* Return the number of bytes allocated at the indicated address. */
9a356c3c	206	size_t ggc_get_size PARAMS ((const void *));
4e00b6fd	207
	208	/* Used by the various collectors to gather and print statistics that
	209	do not depend on the collector in use. */
2a8997e8	210	void ggc_print_common_statistics PARAMS ((FILE , ggc_statistics ));
74647769	211
74647769	212	/* Print allocation statistics. */
2a8997e8	213	extern void ggc_print_statistics PARAMS ((void));
44acf429	214	void stringpool_statistics PARAMS ((void));