[gcc.git] / boehm-gc / ptr_chck.c

/* 
 * Copyright (c) 1991-1994 by Xerox Corporation.  All rights reserved.
 *
 * THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED
 * OR IMPLIED.  ANY USE IS AT YOUR OWN RISK.
 *
 * Permission is hereby granted to use or copy this program
 * for any purpose,  provided the above notices are retained on all copies.
 * Permission to modify the code and to distribute modified code is granted,
 * provided the above notices are retained, and a notice that the code was
 * modified is included with the above copyright notice.
 */
/* Boehm, September 19, 1995 1:26 pm PDT */

#include "gc_priv.h"
#include "gc_mark.h"

#ifdef __STDC__
void GC_default_same_obj_print_proc(GC_PTR p, GC_PTR q)
#else
void GC_default_same_obj_print_proc (p, q)
GC_PTR p, q;
#endif
{
    GC_err_printf2("0x%lx and 0x%lx are not in the same object\n",
    		   (unsigned long)p, (unsigned long)q);
    ABORT("GC_same_obj test failed");
}

void (*GC_same_obj_print_proc) GC_PROTO((GC_PTR, GC_PTR))
		= GC_default_same_obj_print_proc;

/* Check that p and q point to the same object.  Call		*/
/* *GC_same_obj_print_proc if they don't.			*/
/* Returns the first argument.  (Return value may be hard 	*/
/* to use,due to typing issues.  But if we had a suitable 	*/
/* preprocessor ...)						*/
/* Succeeds if neither p nor q points to the heap.		*/
/* We assume this is performance critical.  (It shouldn't	*/
/* be called by production code, but this can easily make	*/
/* debugging intolerably slow.)					*/
#ifdef __STDC__
  GC_PTR GC_same_obj(register void *p, register void *q)
#else
  GC_PTR GC_same_obj(p, q)
  register char *p, *q;
#endif
{
    register struct hblk *h;
    register hdr *hhdr;
    register ptr_t base, limit;
    register word sz;
    
    if (!GC_is_initialized) GC_init();
    hhdr = HDR((word)p);
    if (hhdr == 0) {
   	if (divHBLKSZ((word)p) != divHBLKSZ((word)q)
   	    && HDR((word)q) != 0) {
   	    goto fail;
   	}
   	return(p);
    }
    /* If it's a pointer to the middle of a large object, move it	*/
    /* to the beginning.						*/
    if (IS_FORWARDING_ADDR_OR_NIL(hhdr)) {
    	h = HBLKPTR(p) - (word)hhdr;
    	hhdr = HDR(h);
	while (IS_FORWARDING_ADDR_OR_NIL(hhdr)) {
	   h = FORWARDED_ADDR(h, hhdr);
	   hhdr = HDR(h);
	}
	limit = (ptr_t)((word *)h + HDR_WORDS + hhdr -> hb_sz);
	if ((ptr_t)p >= limit || (ptr_t)q >= limit || (ptr_t)q < (ptr_t)h ) {
	    goto fail;
	}
	return(p);
    }
    sz = WORDS_TO_BYTES(hhdr -> hb_sz);
    if (sz > WORDS_TO_BYTES(MAXOBJSZ)) {
      base = (ptr_t)HBLKPTR(p);
      limit = base + sz;
      if ((ptr_t)p >= limit) {
        goto fail;
      }
    } else {
#     ifdef ALL_INTERIOR_POINTERS
	register map_entry_type map_entry;
	register int pdispl;
	
	pdispl = HBLKDISPL(p);
	map_entry = MAP_ENTRY((hhdr -> hb_map), pdispl);
	if (map_entry == OBJ_INVALID) {
            goto fail;
        } else {
            base = (char *)((word)p & ~(WORDS_TO_BYTES(1) - 1));
            base -= WORDS_TO_BYTES(map_entry);
	}
#     else
	register int offset = HBLKDISPL(p) - HDR_BYTES;
	register word correction = offset % sz;
	
	if (HBLKPTR(p) != HBLKPTR(q)) {
	    /* The following computation otherwise fails in this case */
	    goto fail;
	}
	base = (ptr_t)p - correction;
#     endif
      limit = base + sz;
    }
    /* [base, limit) delimits the object containing p, if any.	*/
    /* If p is not inside a valid object, then either q is	*/
    /* also outside any valid object, or it is outside 		*/
    /* [base, limit).						*/
    if ((ptr_t)q >= limit || (ptr_t)q < base) {
    	goto fail;
    }
    return(p);
fail:
    (*GC_same_obj_print_proc)((ptr_t)p, (ptr_t)q);
    return(p);
}

#ifdef __STDC__
void GC_default_is_valid_displacement_print_proc (GC_PTR p)
#else
void GC_default_is_valid_displacement_print_proc (p)
GC_PTR p;
#endif
{
    GC_err_printf1("0x%lx does not point to valid object displacement\n",
    		   (unsigned long)p);
    ABORT("GC_is_valid_displacement test failed");
}

void (*GC_is_valid_displacement_print_proc) GC_PROTO((GC_PTR)) = 
	GC_default_is_valid_displacement_print_proc;

/* Check that if p is a pointer to a heap page, then it points to	*/
/* a valid displacement within a heap object.				*/
/* Uninteresting with ALL_INTERIOR_POINTERS.				*/
/* Always returns its argument.						*/
/* Note that we don't lock, since nothing relevant about the header	*/
/* should change while we have a valid object pointer to the block.	*/
#ifdef __STDC__
  void * GC_is_valid_displacement(void *p)
#else
  char *GC_is_valid_displacement(p)
  char *p;
#endif
{
    register hdr *hhdr;
    register word pdispl;
    register struct hblk *h;
    register map_entry_type map_entry;
    register word sz;
    
    if (!GC_is_initialized) GC_init();
    hhdr = HDR((word)p);
    if (hhdr == 0) return(p);
    h = HBLKPTR(p);
#   ifdef ALL_INTERIOR_POINTERS
	while (IS_FORWARDING_ADDR_OR_NIL(hhdr)) {
	   h = FORWARDED_ADDR(h, hhdr);
	   hhdr = HDR(h);
	}
#   endif
    if (IS_FORWARDING_ADDR_OR_NIL(hhdr)) {
    	goto fail;
    }
    sz = WORDS_TO_BYTES(hhdr -> hb_sz);
    pdispl = HBLKDISPL(p);
    map_entry = MAP_ENTRY((hhdr -> hb_map), pdispl);
    if (map_entry == OBJ_INVALID
    	|| sz > MAXOBJSZ && (ptr_t)p >= (ptr_t)h + sz) {
    	goto fail;
    }
    return(p);
fail:
    (*GC_is_valid_displacement_print_proc)((ptr_t)p);
    return(p);
}

#ifdef __STDC__
void GC_default_is_visible_print_proc(GC_PTR p)
#else
void GC_default_is_visible_print_proc(p)
GC_PTR p;
#endif
{
    GC_err_printf1("0x%lx is not a GC visible pointer location\n",
    		   (unsigned long)p);
    ABORT("GC_is_visible test failed");
}

void (*GC_is_visible_print_proc) GC_PROTO((GC_PTR p)) = 
	GC_default_is_visible_print_proc;

/* Could p be a stack address? */
GC_bool GC_on_stack(p)
ptr_t p;
{
#   ifdef THREADS
	return(TRUE);
#   else
	int dummy;
#   	ifdef STACK_GROWS_DOWN
	    if ((ptr_t)p >= (ptr_t)(&dummy) && (ptr_t)p < GC_stackbottom ) {
	    	return(TRUE);
	    }
#	else
	    if ((ptr_t)p <= (ptr_t)(&dummy) && (ptr_t)p > GC_stackbottom ) {
	    	return(TRUE);
	    }
#	endif
	return(FALSE);
#   endif
}

/* Check that p is visible						*/
/* to the collector as a possibly pointer containing location.		*/
/* If it isn't invoke *GC_is_visible_print_proc.			*/
/* Returns the argument in all cases.  May erroneously succeed		*/
/* in hard cases.  (This is intended for debugging use with		*/
/* untyped allocations.  The idea is that it should be possible, though	*/
/* slow, to add such a call to all indirect pointer stores.)		*/
/* Currently useless for multithreaded worlds.				*/
#ifdef __STDC__
  void * GC_is_visible(void *p)
#else
  char *GC_is_visible(p)
  char *p;
#endif
{
    register hdr *hhdr;
    
    if ((word)p & (ALIGNMENT - 1)) goto fail;
    if (!GC_is_initialized) GC_init();
#   ifdef THREADS
	hhdr = HDR((word)p);
        if (hhdr != 0 && GC_base(p) == 0) {
            goto fail;
        } else {
            /* May be inside thread stack.  We can't do much. */
            return(p);
        }
#   else
	/* Check stack first: */
	  if (GC_on_stack(p)) return(p);
	hhdr = HDR((word)p);
    	if (hhdr == 0) {
    	    GC_bool result;
    	    
    	    if (GC_is_static_root(p)) return(p);
    	    /* Else do it again correctly:	*/
#           if (defined(DYNAMIC_LOADING) || defined(MSWIN32) || defined(PCR)) \
                && !defined(SRC_M3)
    	        DISABLE_SIGNALS();
    	        GC_register_dynamic_libraries();
    	        result = GC_is_static_root(p);
    	        ENABLE_SIGNALS();
    	        if (result) return(p);
#	    endif
    	    goto fail;
    	} else {
    	    /* p points to the heap. */
    	    word descr;
    	    ptr_t base = GC_base(p);	/* Should be manually inlined? */
    	    
    	    if (base == 0) goto fail;
    	    if (HBLKPTR(base) != HBLKPTR(p)) hhdr = HDR((word)p);
    	    descr = hhdr -> hb_descr;
    retry:
    	    switch(descr & DS_TAGS) {
    	        case DS_LENGTH:
    	            if ((word)((ptr_t)p - (ptr_t)base) > (word)descr) goto fail;
    	            break;
    	        case DS_BITMAP:
    	            if ((ptr_t)p - (ptr_t)base
    	                 >= WORDS_TO_BYTES(BITMAP_BITS)
    	                 || ((word)p & (sizeof(word) - 1))) goto fail;
    	            if (!((1 << (WORDSZ - ((ptr_t)p - (ptr_t)base) - 1))
    	            	  & descr)) goto fail;
    	            break;
    	        case DS_PROC:
    	            /* We could try to decipher this partially. 	*/
    	            /* For now we just punt.				*/
    	            break;
    	        case DS_PER_OBJECT:
    	            descr = *(word *)((ptr_t)base + (descr & ~DS_TAGS));
    	            goto retry;
    	    }
    	    return(p);
    	}
#   endif
fail:
    (*GC_is_visible_print_proc)((ptr_t)p);
    return(p);
}


GC_PTR GC_pre_incr (p, how_much)
GC_PTR *p;
size_t how_much;
{
    GC_PTR initial = *p;
    GC_PTR result = GC_same_obj((GC_PTR)((word)initial + how_much), initial);
    
#   ifndef ALL_INTERIOR_POINTERS
    	(void) GC_is_valid_displacement(result);
#   endif
    return (*p = result);
}

GC_PTR GC_post_incr (p, how_much)
GC_PTR *p;
size_t how_much;
{
    GC_PTR initial = *p;
    GC_PTR result = GC_same_obj((GC_PTR)((word)initial + how_much), initial);
 
#   ifndef ALL_INTERIOR_POINTERS
    	(void) GC_is_valid_displacement(result);
#   endif   
    *p = result;
    return(initial);
}
Commit	Line	Data
73ffefd0 TT	1	/*
	2	* Copyright (c) 1991-1994 by Xerox Corporation. All rights reserved.
	3	*
	4	* THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED
	5	* OR IMPLIED. ANY USE IS AT YOUR OWN RISK.
	6	*
	7	* Permission is hereby granted to use or copy this program
	8	* for any purpose, provided the above notices are retained on all copies.
	9	* Permission to modify the code and to distribute modified code is granted,
	10	* provided the above notices are retained, and a notice that the code was
	11	* modified is included with the above copyright notice.
	12	*/
	13	/* Boehm, September 19, 1995 1:26 pm PDT */
	14
	15	#include "gc_priv.h"
	16	#include "gc_mark.h"
	17
	18	#ifdef __STDC__
	19	void GC_default_same_obj_print_proc(GC_PTR p, GC_PTR q)
	20	#else
	21	void GC_default_same_obj_print_proc (p, q)
	22	GC_PTR p, q;
	23	#endif
	24	{
	25	GC_err_printf2("0x%lx and 0x%lx are not in the same object\n",
	26	(unsigned long)p, (unsigned long)q);
	27	ABORT("GC_same_obj test failed");
	28	}
	29
	30	void (*GC_same_obj_print_proc) GC_PROTO((GC_PTR, GC_PTR))
	31	= GC_default_same_obj_print_proc;
	32
	33	/* Check that p and q point to the same object. Call */
	34	/* GC_same_obj_print_proc if they don't. /
	35	/* Returns the first argument. (Return value may be hard */
	36	/* to use,due to typing issues. But if we had a suitable */
	37	/* preprocessor ...) */
	38	/* Succeeds if neither p nor q points to the heap. */
	39	/* We assume this is performance critical. (It shouldn't */
	40	/* be called by production code, but this can easily make */
	41	/* debugging intolerably slow.) */
	42	#ifdef __STDC__
	43	GC_PTR GC_same_obj(register void p, register void q)
	44	#else
	45	GC_PTR GC_same_obj(p, q)
	46	register char p, q;
	47	#endif
	48	{
	49	register struct hblk *h;
	50	register hdr *hhdr;
	51	register ptr_t base, limit;
	52	register word sz;
	53
	54	if (!GC_is_initialized) GC_init();
	55	hhdr = HDR((word)p);
	56	if (hhdr == 0) {
	57	if (divHBLKSZ((word)p) != divHBLKSZ((word)q)
	58	&& HDR((word)q) != 0) {
	59	goto fail;
	60	}
	61	return(p);
	62	}
	63	/* If it's a pointer to the middle of a large object, move it */
	64	/* to the beginning. */
65	if (IS_FORWARDING_ADDR_OR_NIL(hhdr)) {
66	h = HBLKPTR(p) - (word)hhdr;
67	hhdr = HDR(h);
68	while (IS_FORWARDING_ADDR_OR_NIL(hhdr)) {
69	h = FORWARDED_ADDR(h, hhdr);
70	hhdr = HDR(h);
71	}
72	limit = (ptr_t)((word *)h + HDR_WORDS + hhdr -> hb_sz);
73	if ((ptr_t)p >= limit \|\| (ptr_t)q >= limit \|\| (ptr_t)q < (ptr_t)h ) {
74	goto fail;
75	}
76	return(p);
77	}
78	sz = WORDS_TO_BYTES(hhdr -> hb_sz);
79	if (sz > WORDS_TO_BYTES(MAXOBJSZ)) {
80	base = (ptr_t)HBLKPTR(p);
81	limit = base + sz;
82	if ((ptr_t)p >= limit) {
83	goto fail;
84	}
85	} else {
86	# ifdef ALL_INTERIOR_POINTERS
87	register map_entry_type map_entry;
88	register int pdispl;
89
90	pdispl = HBLKDISPL(p);
91	map_entry = MAP_ENTRY((hhdr -> hb_map), pdispl);
92	if (map_entry == OBJ_INVALID) {
93	goto fail;
94	} else {
95	base = (char *)((word)p & ~(WORDS_TO_BYTES(1) - 1));
96	base -= WORDS_TO_BYTES(map_entry);
97	}
98	# else
99	register int offset = HBLKDISPL(p) - HDR_BYTES;
100	register word correction = offset % sz;
101
102	if (HBLKPTR(p) != HBLKPTR(q)) {
103	/* The following computation otherwise fails in this case */
104	goto fail;
105	}
106	base = (ptr_t)p - correction;
107	# endif
108	limit = base + sz;
109	}
110	/* [base, limit) delimits the object containing p, if any. */
111	/* If p is not inside a valid object, then either q is */
112	/* also outside any valid object, or it is outside */
113	/* [base, limit). */
114	if ((ptr_t)q >= limit \|\| (ptr_t)q < base) {
115	goto fail;
116	}
117	return(p);
118	fail:
119	(*GC_same_obj_print_proc)((ptr_t)p, (ptr_t)q);
120	return(p);
121	}
122
123	#ifdef __STDC__
124	void GC_default_is_valid_displacement_print_proc (GC_PTR p)
125	#else
126	void GC_default_is_valid_displacement_print_proc (p)
127	GC_PTR p;
128	#endif
129	{
130	GC_err_printf1("0x%lx does not point to valid object displacement\n",
131	(unsigned long)p);
132	ABORT("GC_is_valid_displacement test failed");
133	}
134
135	void (*GC_is_valid_displacement_print_proc) GC_PROTO((GC_PTR)) =
136	GC_default_is_valid_displacement_print_proc;
137
138	/* Check that if p is a pointer to a heap page, then it points to */
139	/* a valid displacement within a heap object. */
140	/* Uninteresting with ALL_INTERIOR_POINTERS. */
141	/* Always returns its argument. */
142	/* Note that we don't lock, since nothing relevant about the header */
143	/* should change while we have a valid object pointer to the block. */
144	#ifdef __STDC__
145	void * GC_is_valid_displacement(void *p)
146	#else
147	char *GC_is_valid_displacement(p)
148	char *p;
149	#endif
150	{
151	register hdr *hhdr;
152	register word pdispl;
153	register struct hblk *h;
154	register map_entry_type map_entry;
155	register word sz;
156
157	if (!GC_is_initialized) GC_init();
158	hhdr = HDR((word)p);
159	if (hhdr == 0) return(p);
160	h = HBLKPTR(p);
161	# ifdef ALL_INTERIOR_POINTERS
162	while (IS_FORWARDING_ADDR_OR_NIL(hhdr)) {
163	h = FORWARDED_ADDR(h, hhdr);
164	hhdr = HDR(h);
165	}
166	# endif
167	if (IS_FORWARDING_ADDR_OR_NIL(hhdr)) {
168	goto fail;
169	}
170	sz = WORDS_TO_BYTES(hhdr -> hb_sz);
171	pdispl = HBLKDISPL(p);
172	map_entry = MAP_ENTRY((hhdr -> hb_map), pdispl);
173	if (map_entry == OBJ_INVALID
174	\|\| sz > MAXOBJSZ && (ptr_t)p >= (ptr_t)h + sz) {
175	goto fail;
176	}
177	return(p);
178	fail:
179	(*GC_is_valid_displacement_print_proc)((ptr_t)p);
180	return(p);
181	}
182
183	#ifdef __STDC__
184	void GC_default_is_visible_print_proc(GC_PTR p)
185	#else
186	void GC_default_is_visible_print_proc(p)
187	GC_PTR p;
188	#endif
189	{
190	GC_err_printf1("0x%lx is not a GC visible pointer location\n",
191	(unsigned long)p);
192	ABORT("GC_is_visible test failed");
193	}
194
195	void (*GC_is_visible_print_proc) GC_PROTO((GC_PTR p)) =
196	GC_default_is_visible_print_proc;
197
198	/* Could p be a stack address? */
199	GC_bool GC_on_stack(p)
200	ptr_t p;
201	{
202	# ifdef THREADS
203	return(TRUE);
204	# else
205	int dummy;
206	# ifdef STACK_GROWS_DOWN
207	if ((ptr_t)p >= (ptr_t)(&dummy) && (ptr_t)p < GC_stackbottom ) {
208	return(TRUE);
209	}
210	# else
211	if ((ptr_t)p <= (ptr_t)(&dummy) && (ptr_t)p > GC_stackbottom ) {
212	return(TRUE);
213	}
214	# endif
215	return(FALSE);
216	# endif
217	}
218
219	/* Check that p is visible */
220	/* to the collector as a possibly pointer containing location. */
221	/* If it isn't invoke GC_is_visible_print_proc. /
222	/* Returns the argument in all cases. May erroneously succeed */
223	/* in hard cases. (This is intended for debugging use with */
224	/* untyped allocations. The idea is that it should be possible, though */
225	/* slow, to add such a call to all indirect pointer stores.) */
226	/* Currently useless for multithreaded worlds. */
227	#ifdef __STDC__
228	void * GC_is_visible(void *p)
229	#else
230	char *GC_is_visible(p)
231	char *p;
232	#endif
233	{
234	register hdr *hhdr;
235
236	if ((word)p & (ALIGNMENT - 1)) goto fail;
237	if (!GC_is_initialized) GC_init();
238	# ifdef THREADS
239	hhdr = HDR((word)p);
240	if (hhdr != 0 && GC_base(p) == 0) {
241	goto fail;
242	} else {
243	/* May be inside thread stack. We can't do much. */
244	return(p);
245	}
246	# else
247	/* Check stack first: */
248	if (GC_on_stack(p)) return(p);
249	hhdr = HDR((word)p);
250	if (hhdr == 0) {
251	GC_bool result;
252
253	if (GC_is_static_root(p)) return(p);
254	/* Else do it again correctly: */
255	# if (defined(DYNAMIC_LOADING) \|\| defined(MSWIN32) \|\| defined(PCR)) \
256	&& !defined(SRC_M3)
257	DISABLE_SIGNALS();
258	GC_register_dynamic_libraries();
259	result = GC_is_static_root(p);
260	ENABLE_SIGNALS();
261	if (result) return(p);
262	# endif
263	goto fail;
264	} else {
265	/* p points to the heap. */
266	word descr;
267	ptr_t base = GC_base(p); /* Should be manually inlined? */
268
269	if (base == 0) goto fail;
270	if (HBLKPTR(base) != HBLKPTR(p)) hhdr = HDR((word)p);
271	descr = hhdr -> hb_descr;
272	retry:
273	switch(descr & DS_TAGS) {
274	case DS_LENGTH:
275	if ((word)((ptr_t)p - (ptr_t)base) > (word)descr) goto fail;
276	break;
277	case DS_BITMAP:
278	if ((ptr_t)p - (ptr_t)base
279	>= WORDS_TO_BYTES(BITMAP_BITS)
280	\|\| ((word)p & (sizeof(word) - 1))) goto fail;
281	if (!((1 << (WORDSZ - ((ptr_t)p - (ptr_t)base) - 1))
282	& descr)) goto fail;
283	break;
284	case DS_PROC:
285	/* We could try to decipher this partially. */
286	/* For now we just punt. */
287	break;
288	case DS_PER_OBJECT:
289	descr = (word )((ptr_t)base + (descr & ~DS_TAGS));
290	goto retry;
291	}
292	return(p);
293	}
294	# endif
295	fail:
296	(*GC_is_visible_print_proc)((ptr_t)p);
297	return(p);
298	}
299
300
301	GC_PTR GC_pre_incr (p, how_much)
302	GC_PTR *p;
303	size_t how_much;
304	{
305	GC_PTR initial = *p;
306	GC_PTR result = GC_same_obj((GC_PTR)((word)initial + how_much), initial);
307
308	# ifndef ALL_INTERIOR_POINTERS
309	(void) GC_is_valid_displacement(result);
310	# endif
311	return (*p = result);
312	}
313
314	GC_PTR GC_post_incr (p, how_much)
315	GC_PTR *p;
316	size_t how_much;
317	{
318	GC_PTR initial = *p;
319	GC_PTR result = GC_same_obj((GC_PTR)((word)initial + how_much), initial);
320
321	# ifndef ALL_INTERIOR_POINTERS
322	(void) GC_is_valid_displacement(result);
323	# endif
324	*p = result;
325	return(initial);
326	}