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[/] [openrisc/] [trunk/] [gnu-dev/] [or1k-gcc/] [boehm-gc/] [ptr_chck.c] - Rev 775
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/* * 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. */ /* * These are checking routines calls to which could be inserted by a * preprocessor to validate C pointer arithmetic. */ #include "private/gc_pmark.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 + 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 > MAXOBJBYTES) { base = (ptr_t)HBLKPTR(p); limit = base + sz; if ((ptr_t)p >= limit) { goto fail; } } else { register int map_entry; register int pdispl = HBLKDISPL(p); map_entry = MAP_ENTRY((hhdr -> hb_map), pdispl); if (map_entry > CPP_MAX_OFFSET) { map_entry = BYTES_TO_WORDS(pdispl) % BYTES_TO_WORDS(sz); if (HBLKPTR(p) != HBLKPTR(q)) goto fail; /* W/o this check, we might miss an error if */ /* q points to the first object on a page, and */ /* points just before the page. */ } base = (char *)((word)p & ~(WORDS_TO_BYTES(1) - 1)); base -= WORDS_TO_BYTES(map_entry); 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 GC_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); if (GC_all_interior_pointers) { while (IS_FORWARDING_ADDR_OR_NIL(hhdr)) { h = FORWARDED_ADDR(h, hhdr); hhdr = HDR(h); } } 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 > MAXOBJBYTES && (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(MSWINCE) || defined (CYGWIN32) || 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 & GC_DS_TAGS) { case GC_DS_LENGTH: if ((word)((ptr_t)p - (ptr_t)base) > (word)descr) goto fail; break; case GC_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 GC_DS_PROC: /* We could try to decipher this partially. */ /* For now we just punt. */ break; case GC_DS_PER_OBJECT: if ((signed_word)descr >= 0) { descr = *(word *)((ptr_t)base + (descr & ~GC_DS_TAGS)); } else { ptr_t type_descr = *(ptr_t *)base; descr = *(word *)(type_descr - (descr - (GC_DS_PER_OBJECT - GC_INDIR_PER_OBJ_BIAS))); } 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); if (!GC_all_interior_pointers) { (void) GC_is_valid_displacement(result); } 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); if (!GC_all_interior_pointers) { (void) GC_is_valid_displacement(result); } *p = result; return(initial); }
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