/* "Bag-of-pages" zone garbage collector for the GNU compiler.
- Copyright (C) 1999, 2000, 2001, 2002, 2003, 2004, 2005
+ Copyright (C) 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2007, 2008
Free Software Foundation, Inc.
Contributed by Richard Henderson (rth@redhat.com) and Daniel Berlin
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
+Software Foundation; either version 3, or (at your option) any later
version.
GCC is distributed in the hope that it will be useful, but WITHOUT ANY
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, 51 Franklin Street, Fifth Floor, Boston, MA
-02110-1301, USA. */
+along with GCC; see the file COPYING3. If not see
+<http://www.gnu.org/licenses/>. */
#include "config.h"
#include "system.h"
#include "params.h"
#include "bitmap.h"
-#ifdef ENABLE_VALGRIND_CHECKING
-# ifdef HAVE_VALGRIND_MEMCHECK_H
-# include <valgrind/memcheck.h>
-# elif defined HAVE_MEMCHECK_H
-# include <memcheck.h>
-# else
-# include <valgrind.h>
-# endif
-#else
-/* Avoid #ifdef:s when we can help it. */
-#define VALGRIND_DISCARD(x)
-#define VALGRIND_MALLOCLIKE_BLOCK(w,x,y,z)
-#define VALGRIND_FREELIKE_BLOCK(x,y)
-#endif
-
/* Prefer MAP_ANON(YMOUS) to /dev/zero, since we don't need to keep a
file open. Prefer either to valloc. */
#ifdef HAVE_MMAP_ANON
return base[L1][L2];
}
+/* Traverse the page table and find the entry for a page.
+ Return NULL if the object wasn't allocated via the GC. */
+
+static inline page_entry *
+lookup_page_table_if_allocated (const void *p)
+{
+ page_entry ***base;
+ size_t L1, L2;
+
+#if HOST_BITS_PER_PTR <= 32
+ base = &G.lookup[0];
+#else
+ page_table table = G.lookup;
+ size_t high_bits = (size_t) p & ~ (size_t) 0xffffffff;
+ while (1)
+ {
+ if (table == NULL)
+ return NULL;
+ if (table->high_bits == high_bits)
+ break;
+ table = table->next;
+ }
+ base = &table->table[0];
+#endif
+
+ /* Extract the level 1 and 2 indices. */
+ L1 = LOOKUP_L1 (p);
+ if (! base[L1])
+ return NULL;
+
+ L2 = LOOKUP_L2 (p);
+ if (L2 >= PAGE_L2_SIZE)
+ return NULL;
+ /* We might have a page entry which does not correspond exactly to a
+ system page. */
+ if (base[L1][L2] && (char *) p < base[L1][L2]->page)
+ return NULL;
+
+ return base[L1][L2];
+}
+
/* Set the page table entry for the page that starts at P. If ENTRY
is NULL, clear the entry. */
max_size);
}
+/* highest_bit assumes that alloc_type is 32 bits. */
+extern char check_alloc_type_size[(sizeof (alloc_type) == 4) ? 1 : -1];
+
+/* Find the highest set bit in VALUE. Returns the bit number of that
+ bit, using the same values as ffs. */
+static inline alloc_type
+highest_bit (alloc_type value)
+{
+ /* This also assumes that alloc_type is unsigned. */
+ value |= value >> 1;
+ value |= value >> 2;
+ value |= value >> 4;
+ value |= value >> 8;
+ value |= value >> 16;
+ value = value ^ (value >> 1);
+ return alloc_ffs (value);
+}
+
+/* Find the offset from the start of an object to P, which may point
+ into the interior of the object. */
+
+static unsigned long
+zone_find_object_offset (alloc_type *alloc_bits, size_t start_word,
+ size_t start_bit)
+{
+ unsigned int offset_in_bits;
+ alloc_type alloc_word = alloc_bits[start_word];
+
+ /* Mask off any bits after the initial bit, but make sure to include
+ the initial bit in the result. Note that START_BIT is
+ 0-based. */
+ if (start_bit < 8 * sizeof (alloc_type) - 1)
+ alloc_word &= (1 << (start_bit + 1)) - 1;
+ offset_in_bits = start_bit;
+
+ /* Search for the start of the object. */
+ while (alloc_word == 0 && start_word > 0)
+ {
+ alloc_word = alloc_bits[--start_word];
+ offset_in_bits += 8 * sizeof (alloc_type);
+ }
+ /* We must always find a set bit. */
+ gcc_assert (alloc_word != 0);
+ /* Note that the result of highest_bit is 1-based. */
+ offset_in_bits -= highest_bit (alloc_word) - 1;
+
+ return BYTES_PER_ALLOC_BIT * offset_in_bits;
+}
+
/* Allocate the mark bits for every zone, and set the pointers on each
page. */
static void
/* Pretend we don't have access to the allocated pages. We'll enable
access to smaller pieces of the area in ggc_alloc. Discard the
handle to avoid handle leak. */
- VALGRIND_DISCARD (VALGRIND_MAKE_NOACCESS (page, size));
+ VALGRIND_DISCARD (VALGRIND_MAKE_MEM_NOACCESS (page, size));
return page;
}
/* Mark the page as inaccessible. Discard the handle to
avoid handle leak. */
- VALGRIND_DISCARD (VALGRIND_MAKE_NOACCESS (entry->common.page,
- SMALL_PAGE_SIZE));
+ VALGRIND_DISCARD (VALGRIND_MAKE_MEM_NOACCESS (entry->common.page,
+ SMALL_PAGE_SIZE));
entry->next = entry->common.zone->free_pages;
entry->common.zone->free_pages = entry;
if (bin > NUM_FREE_BINS)
{
bin = 0;
- VALGRIND_DISCARD (VALGRIND_MAKE_WRITABLE (chunk, sizeof (struct alloc_chunk)));
+ VALGRIND_DISCARD (VALGRIND_MAKE_MEM_UNDEFINED (chunk,
+ sizeof (struct
+ alloc_chunk)));
chunk->size = size;
chunk->next_free = zone->free_chunks[bin];
- VALGRIND_DISCARD (VALGRIND_MAKE_NOACCESS (ptr + sizeof (struct alloc_chunk),
- size - sizeof (struct alloc_chunk)));
+ VALGRIND_DISCARD (VALGRIND_MAKE_MEM_NOACCESS (ptr
+ + sizeof (struct
+ alloc_chunk),
+ size
+ - sizeof (struct
+ alloc_chunk)));
}
else
{
- VALGRIND_DISCARD (VALGRIND_MAKE_WRITABLE (chunk, sizeof (struct alloc_chunk *)));
+ VALGRIND_DISCARD (VALGRIND_MAKE_MEM_UNDEFINED (chunk,
+ sizeof (struct
+ alloc_chunk *)));
chunk->next_free = zone->free_chunks[bin];
- VALGRIND_DISCARD (VALGRIND_MAKE_NOACCESS (ptr + sizeof (struct alloc_chunk *),
- size - sizeof (struct alloc_chunk *)));
+ VALGRIND_DISCARD (VALGRIND_MAKE_MEM_NOACCESS (ptr
+ + sizeof (struct
+ alloc_chunk *),
+ size
+ - sizeof (struct
+ alloc_chunk *)));
}
zone->free_chunks[bin] = chunk;
#ifdef ENABLE_GC_CHECKING
/* `Poison' the entire allocated object. */
- VALGRIND_DISCARD (VALGRIND_MAKE_WRITABLE (result, size));
+ VALGRIND_DISCARD (VALGRIND_MAKE_MEM_UNDEFINED (result, size));
memset (result, 0xaf, size);
- VALGRIND_DISCARD (VALGRIND_MAKE_NOACCESS (result + orig_size,
- size - orig_size));
+ VALGRIND_DISCARD (VALGRIND_MAKE_MEM_NOACCESS (result + orig_size,
+ size - orig_size));
#endif
/* Tell Valgrind that the memory is there, but its content isn't
defined. The bytes at the end of the object are still marked
unaccessible. */
- VALGRIND_DISCARD (VALGRIND_MAKE_WRITABLE (result, orig_size));
+ VALGRIND_DISCARD (VALGRIND_MAKE_MEM_UNDEFINED (result, orig_size));
/* Keep track of how many bytes are being allocated. This
information is used in deciding when to collect. */
}
}
+/* Mark function for strings. */
+
+void
+gt_ggc_m_S (const void *p)
+{
+ page_entry *entry;
+ unsigned long offset;
+
+ if (!p)
+ return;
+
+ /* Look up the page on which the object is alloced. . */
+ entry = lookup_page_table_if_allocated (p);
+ if (! entry)
+ return;
+
+ if (entry->pch_p)
+ {
+ size_t alloc_word, alloc_bit, t;
+ t = ((const char *) p - pch_zone.page) / BYTES_PER_ALLOC_BIT;
+ alloc_word = t / (8 * sizeof (alloc_type));
+ alloc_bit = t % (8 * sizeof (alloc_type));
+ offset = zone_find_object_offset (pch_zone.alloc_bits, alloc_word,
+ alloc_bit);
+ }
+ else if (entry->large_p)
+ {
+ struct large_page_entry *le = (struct large_page_entry *) entry;
+ offset = ((const char *) p) - entry->page;
+ gcc_assert (offset < le->bytes);
+ }
+ else
+ {
+ struct small_page_entry *se = (struct small_page_entry *) entry;
+ unsigned int start_word = zone_get_object_alloc_word (p);
+ unsigned int start_bit = zone_get_object_alloc_bit (p);
+ offset = zone_find_object_offset (se->alloc_bits, start_word, start_bit);
+
+ /* On some platforms a char* will not necessarily line up on an
+ allocation boundary, so we have to update the offset to
+ account for the leftover bytes. */
+ offset += (size_t) p % BYTES_PER_ALLOC_BIT;
+ }
+
+ if (offset)
+ {
+ /* Here we've seen a char* which does not point to the beginning
+ of an allocated object. We assume it points to the middle of
+ a STRING_CST. */
+ gcc_assert (offset == offsetof (struct tree_string, str));
+ p = ((const char *) p) - offset;
+ gt_ggc_mx_lang_tree_node ((void *) p);
+ return;
+ }
+
+ /* Inefficient, but also unlikely to matter. */
+ ggc_set_mark (p);
+}
+
/* If P is not marked, mark it and return false. Otherwise return true.
P must have been allocated by the GC allocator; it mustn't point to
static objects, stack variables, or memory allocated with malloc. */
{
if (last_free)
{
- VALGRIND_DISCARD (VALGRIND_MAKE_WRITABLE (last_free,
- object
- - last_free));
+ VALGRIND_DISCARD (VALGRIND_MAKE_MEM_UNDEFINED (last_free,
+ object
+ - last_free));
poison_region (last_free, object - last_free);
free_chunk (last_free, object - last_free, zone);
last_free = NULL;
{
*spp = snext;
#ifdef ENABLE_GC_CHECKING
- VALGRIND_DISCARD (VALGRIND_MAKE_WRITABLE (sp->common.page, SMALL_PAGE_SIZE));
+ VALGRIND_DISCARD (VALGRIND_MAKE_MEM_UNDEFINED (sp->common.page,
+ SMALL_PAGE_SIZE));
/* Poison the page. */
memset (sp->common.page, 0xb5, SMALL_PAGE_SIZE);
#endif
}
else if (last_free)
{
- VALGRIND_DISCARD (VALGRIND_MAKE_WRITABLE (last_free,
- object - last_free));
+ VALGRIND_DISCARD (VALGRIND_MAKE_MEM_UNDEFINED (last_free,
+ object - last_free));
poison_region (last_free, object - last_free);
free_chunk (last_free, object - last_free, zone);
}
fatal_error ("can't seek PCH file: %m");
if (fwrite (d->alloc_bits, d->alloc_size, 1, f) != 1)
- fatal_error ("can't write PCH fle: %m");
+ fatal_error ("can't write PCH file: %m");
/* Done with the PCH, so write out our footer. */
if (fwrite (&d->d, sizeof (d->d), 1, f) != 1)
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