/* ELF strtab with GC and suffix merging support.
- Copyright 2001, 2002 Free Software Foundation, Inc.
+ Copyright 2001, 2002, 2003 Free Software Foundation, Inc.
Written by Jakub Jelinek <jakub@redhat.com>.
This file is part of BFD, the Binary File Descriptor library.
struct elf_strtab_hash_entry
{
struct bfd_hash_entry root;
- /* Length of this entry. */
- unsigned int len;
+ /* Length of this entry. This includes the zero terminator. */
+ int len;
unsigned int refcount;
union {
/* Index within the merged section. */
bfd_size_type index;
- /* Entry this is a suffix of (if len is 0). */
+ /* Entry this is a suffix of (if len < 0). */
struct elf_strtab_hash_entry *suffix;
- struct elf_strtab_hash_entry *next;
} u;
};
if (entry->len == 0)
{
entry->len = strlen (str) + 1;
+ /* 2G strings lose. */
+ BFD_ASSERT (entry->len > 0);
if (tab->size == tab->alloced)
{
bfd_size_type amt = sizeof (struct elf_strtab_hash_entry *);
for (i = 1; i < tab->size; ++i)
{
register const char *str;
- register size_t len;
+ register unsigned int len;
- str = tab->array[i]->root.string;
- len = tab->array[i]->len;
BFD_ASSERT (tab->array[i]->refcount == 0);
- if (len == 0)
+ len = tab->array[i]->len;
+ if ((int) len < 0)
continue;
+ str = tab->array[i]->root.string;
if (bfd_bwrite (str, len, abfd) != len)
return FALSE;
return TRUE;
}
-/* Compare two elf_strtab_hash_entry structures. This is called via qsort. */
+/* Compare two elf_strtab_hash_entry structures. Called via qsort. */
static int
-cmplengthentry (const void *a, const void *b)
+strrevcmp (const void *a, const void *b)
{
struct elf_strtab_hash_entry *A = *(struct elf_strtab_hash_entry **) a;
struct elf_strtab_hash_entry *B = *(struct elf_strtab_hash_entry **) b;
+ unsigned int lenA = A->len;
+ unsigned int lenB = B->len;
+ const unsigned char *s = A->root.string + lenA - 1;
+ const unsigned char *t = B->root.string + lenB - 1;
+ int l = lenA < lenB ? lenA : lenB;
- if (A->len < B->len)
- return 1;
- else if (A->len > B->len)
- return -1;
-
- return memcmp (A->root.string, B->root.string, A->len);
+ while (l)
+ {
+ if (*s != *t)
+ return (int) *s - (int) *t;
+ s--;
+ t--;
+ l--;
+ }
+ return lenA - lenB;
}
-static int
-last4_eq (const void *a, const void *b)
+static inline int
+is_suffix (const struct elf_strtab_hash_entry *A,
+ const struct elf_strtab_hash_entry *B)
{
- const struct elf_strtab_hash_entry *A = a;
- const struct elf_strtab_hash_entry *B = b;
-
- if (memcmp (A->root.string + A->len - 5, B->root.string + B->len - 5, 4)
- != 0)
- /* This was a hashtable collision. */
- return 0;
-
if (A->len <= B->len)
/* B cannot be a suffix of A unless A is equal to B, which is guaranteed
not to be equal by the hash table. */
return 0;
return memcmp (A->root.string + (A->len - B->len),
- B->root.string, B->len - 5) == 0;
+ B->root.string, B->len - 1) == 0;
}
/* This function assigns final string table offsets for used strings,
void
_bfd_elf_strtab_finalize (struct elf_strtab_hash *tab)
{
- struct elf_strtab_hash_entry **array, **a, **end, *e;
- htab_t last4tab = NULL;
+ struct elf_strtab_hash_entry **array, **a, *e;
bfd_size_type size, amt;
- struct elf_strtab_hash_entry *last[256], **last_ptr[256];
/* GCC 2.91.66 (egcs-1.1.2) on i386 miscompiles this function when i is
a 64-bit bfd_size_type: a 64-bit target or --enable-64-bit-bfd.
cycles. */
size_t i;
- /* Now sort the strings by length, longest first. */
- array = NULL;
+ /* Sort the strings by suffix and length. */
amt = tab->size * sizeof (struct elf_strtab_hash_entry *);
array = bfd_malloc (amt);
if (array == NULL)
goto alloc_failure;
- memset (last, 0, sizeof (last));
- for (i = 0; i < 256; ++i)
- last_ptr[i] = &last[i];
for (i = 1, a = array; i < tab->size; ++i)
- if (tab->array[i]->refcount)
- *a++ = tab->array[i];
- else
- tab->array[i]->len = 0;
+ {
+ e = tab->array[i];
+ if (e->refcount)
+ {
+ *a++ = e;
+ /* Adjust the length to not include the zero terminator. */
+ e->len -= 1;
+ }
+ else
+ e->len = 0;
+ }
size = a - array;
+ if (size != 0)
+ {
+ qsort (array, size, sizeof (struct elf_strtab_hash_entry *), strrevcmp);
- qsort (array, size, sizeof (struct elf_strtab_hash_entry *), cmplengthentry);
+ /* Loop over the sorted array and merge suffixes. Start from the
+ end because we want eg.
- last4tab = htab_create_alloc (size * 4, NULL, last4_eq, NULL, calloc, free);
- if (last4tab == NULL)
- goto alloc_failure;
+ s1 -> "d"
+ s2 -> "bcd"
+ s3 -> "abcd"
- /* Now insert the strings into hash tables (strings with last 4 characters
- and strings with last character equal), look for longer strings which
- we're suffix of. */
- for (a = array, end = array + size; a < end; a++)
- {
- register hashval_t hash;
- unsigned int c;
- unsigned int j;
- const unsigned char *s;
- void **p;
-
- e = *a;
- if (e->len > 4)
- {
- s = e->root.string + e->len - 1;
- hash = 0;
- for (j = 0; j < 4; j++)
- {
- c = *--s;
- hash += c + (c << 17);
- hash ^= hash >> 2;
- }
- p = htab_find_slot_with_hash (last4tab, e, hash, INSERT);
- if (p == NULL)
- goto alloc_failure;
- if (*p)
- {
- struct elf_strtab_hash_entry *ent;
+ to end up as
- ent = *p;
- e->u.suffix = ent;
- e->len = 0;
- continue;
- }
- else
- *p = e;
- }
- else
- {
- struct elf_strtab_hash_entry *tem;
+ s3 -> "abcd"
+ s2 _____^
+ s1 _______^
- c = e->root.string[e->len - 2] & 0xff;
+ ie. we don't want s1 pointing into the old s2. */
+ e = *--a;
+ e->len += 1;
+ while (--a >= array)
+ {
+ struct elf_strtab_hash_entry *cmp = *a;
- for (tem = last[c]; tem; tem = tem->u.next)
- if (tem->len > e->len
- && memcmp (tem->root.string + (tem->len - e->len),
- e->root.string, e->len - 1) == 0)
- break;
- if (tem)
+ cmp->len += 1;
+ if (is_suffix (e, cmp))
{
- e->u.suffix = tem;
- e->len = 0;
- continue;
+ cmp->u.suffix = e;
+ cmp->len = -cmp->len;
}
+ else
+ e = cmp;
}
-
- c = e->root.string[e->len - 2] & 0xff;
- /* Put longest strings first. */
- *last_ptr[c] = e;
- last_ptr[c] = &e->u.next;
- e->u.next = NULL;
}
alloc_failure:
if (array)
free (array);
- if (last4tab)
- htab_delete (last4tab);
- /* Now assign positions to the strings we want to keep. */
+ /* Assign positions to the strings we want to keep. */
size = 1;
for (i = 1; i < tab->size; ++i)
{
e = tab->array[i];
- if (e->refcount && e->len)
+ if (e->refcount && e->len > 0)
{
e->u.index = size;
size += e->len;
tab->sec_size = size;
- /* And now adjust the rest. */
+ /* Adjust the rest. */
for (i = 1; i < tab->size; ++i)
{
e = tab->array[i];
- if (e->refcount && ! e->len)
- e->u.index = e->u.suffix->u.index
- + (e->u.suffix->len - strlen (e->root.string) - 1);
+ if (e->refcount && e->len < 0)
+ e->u.index = e->u.suffix->u.index + (e->u.suffix->len + e->len);
}
}
struct sec_merge_hash_entry
{
struct bfd_hash_entry root;
- /* Length of this entry. */
+ /* Length of this entry. This includes the zero terminator. */
unsigned int len;
/* Start of this string needs to be aligned to
alignment octets (not 1 << align). */
{
/* Index within the merged section. */
bfd_size_type index;
- /* Entity size (if present in suffix hash tables). */
- unsigned int entsize;
/* Entry this is a suffix of (if alignment is 0). */
struct sec_merge_hash_entry *suffix;
} u;
alignment, we need to insert another copy. */
if (hashp->alignment < alignment)
{
- /* Mark the less aligned copy as deleted. */
- hashp->len = 0;
- hashp->alignment = 0;
+ if (create)
+ {
+ /* Mark the less aligned copy as deleted. */
+ hashp->len = 0;
+ hashp->alignment = 0;
+ }
break;
}
return hashp;
}
static bfd_boolean
-sec_merge_emit (register bfd *abfd, struct sec_merge_hash_entry *entry)
+sec_merge_emit (bfd *abfd, struct sec_merge_hash_entry *entry)
{
struct sec_merge_sec_info *secinfo = entry->secinfo;
asection *sec = secinfo->sec;
return FALSE;
}
-/* Compare two sec_merge_hash_entry structures. This is called via qsort. */
-
-static int
-cmplengthentry (const void *a, const void *b)
-{
- struct sec_merge_hash_entry * A = *(struct sec_merge_hash_entry **) a;
- struct sec_merge_hash_entry * B = *(struct sec_merge_hash_entry **) b;
-
- if (A->len < B->len)
- return 1;
- else if (A->len > B->len)
- return -1;
-
- return memcmp (A->root.string, B->root.string, A->len);
-}
-
-static int
-last4_eq (const void *a, const void *b)
-{
- struct sec_merge_hash_entry * A = (struct sec_merge_hash_entry *) a;
- struct sec_merge_hash_entry * B = (struct sec_merge_hash_entry *) b;
-
- if (memcmp (A->root.string + A->len - 5 * A->u.entsize,
- B->root.string + B->len - 5 * A->u.entsize,
- 4 * A->u.entsize) != 0)
- /* This was a hashtable collision. */
- return 0;
-
- if (A->len <= B->len)
- /* B cannot be a suffix of A unless A is equal to B, which is guaranteed
- not to be equal by the hash table. */
- return 0;
-
- if (A->alignment < B->alignment
- || ((A->len - B->len) & (B->alignment - 1)))
- /* The suffix is not sufficiently aligned. */
- return 0;
-
- return memcmp (A->root.string + (A->len - B->len),
- B->root.string, B->len - 5 * A->u.entsize) == 0;
-}
-
-static int
-last_eq (const void *a, const void *b)
-{
- struct sec_merge_hash_entry * A = (struct sec_merge_hash_entry *) a;
- struct sec_merge_hash_entry * B = (struct sec_merge_hash_entry *) b;
-
- if (B->len >= 5 * A->u.entsize)
- /* Longer strings are just pushed into the hash table,
- they'll be used when looking up for very short strings. */
- return 0;
-
- if (memcmp (A->root.string + A->len - 2 * A->u.entsize,
- B->root.string + B->len - 2 * A->u.entsize,
- A->u.entsize) != 0)
- /* This was a hashtable collision. */
- return 0;
-
- if (A->len <= B->len)
- /* B cannot be a suffix of A unless A is equal to B, which is guaranteed
- not to be equal by the hash table. */
- return 0;
-
- if (A->alignment < B->alignment
- || ((A->len - B->len) & (B->alignment - 1)))
- /* The suffix is not sufficiently aligned. */
- return 0;
-
- return memcmp (A->root.string + (A->len - B->len),
- B->root.string, B->len - 2 * A->u.entsize) == 0;
-}
-
/* Record one section into the hash table. */
static bfd_boolean
record_section (struct sec_merge_info *sinfo,
goto error_return;
}
p++;
- }
+ }
}
else
{
return FALSE;
}
+static int
+strrevcmp (const void *a, const void *b)
+{
+ struct sec_merge_hash_entry *A = *(struct sec_merge_hash_entry **) a;
+ struct sec_merge_hash_entry *B = *(struct sec_merge_hash_entry **) b;
+ unsigned int lenA = A->len;
+ unsigned int lenB = B->len;
+ const unsigned char *s = A->root.string + lenA - 1;
+ const unsigned char *t = B->root.string + lenB - 1;
+ int l = lenA < lenB ? lenA : lenB;
+
+ while (l)
+ {
+ if (*s != *t)
+ return (int) *s - (int) *t;
+ s--;
+ t--;
+ l--;
+ }
+ return lenA - lenB;
+}
+
+/* Like strrevcmp, but for the case where all strings have the same
+ alignment > entsize. */
+
+static int
+strrevcmp_align (const void *a, const void *b)
+{
+ struct sec_merge_hash_entry *A = *(struct sec_merge_hash_entry **) a;
+ struct sec_merge_hash_entry *B = *(struct sec_merge_hash_entry **) b;
+ unsigned int lenA = A->len;
+ unsigned int lenB = B->len;
+ const unsigned char *s = A->root.string + lenA - 1;
+ const unsigned char *t = B->root.string + lenB - 1;
+ int l = lenA < lenB ? lenA : lenB;
+ int tail_align = (lenA & (A->alignment - 1)) - (lenB & (A->alignment - 1));
+
+ if (tail_align != 0)
+ return tail_align;
+
+ while (l)
+ {
+ if (*s != *t)
+ return (int) *s - (int) *t;
+ s--;
+ t--;
+ l--;
+ }
+ return lenA - lenB;
+}
+
+static inline int
+is_suffix (const struct sec_merge_hash_entry *A,
+ const struct sec_merge_hash_entry *B)
+{
+ if (A->len <= B->len)
+ /* B cannot be a suffix of A unless A is equal to B, which is guaranteed
+ not to be equal by the hash table. */
+ return 0;
+
+ return memcmp (A->root.string + (A->len - B->len),
+ B->root.string, B->len) == 0;
+}
+
/* This is a helper function for _bfd_merge_sections. It attempts to
merge strings matching suffixes of longer strings. */
static void
merge_strings (struct sec_merge_info *sinfo)
{
- struct sec_merge_hash_entry **array, **a, **end, *e;
+ struct sec_merge_hash_entry **array, **a, *e;
struct sec_merge_sec_info *secinfo;
- htab_t lasttab = NULL, last4tab = NULL;
bfd_size_type size, amt;
+ unsigned int alignment = 0;
- /* Now sort the strings by length, longest first. */
- array = NULL;
+ /* Now sort the strings */
amt = sinfo->htab->size * sizeof (struct sec_merge_hash_entry *);
array = (struct sec_merge_hash_entry **) bfd_malloc (amt);
if (array == NULL)
for (e = sinfo->htab->first, a = array; e; e = e->next)
if (e->alignment)
- *a++ = e;
+ {
+ *a++ = e;
+ /* Adjust the length to not include the zero terminator. */
+ e->len -= sinfo->htab->entsize;
+ if (alignment != e->alignment)
+ {
+ if (alignment == 0)
+ alignment = e->alignment;
+ else
+ alignment = (unsigned) -1;
+ }
+ }
sinfo->htab->size = a - array;
-
- qsort (array, (size_t) sinfo->htab->size,
- sizeof (struct sec_merge_hash_entry *), cmplengthentry);
-
- last4tab = htab_create_alloc ((size_t) sinfo->htab->size * 4,
- NULL, last4_eq, NULL, calloc, free);
- lasttab = htab_create_alloc ((size_t) sinfo->htab->size * 4,
- NULL, last_eq, NULL, calloc, free);
- if (lasttab == NULL || last4tab == NULL)
- goto alloc_failure;
-
- /* Now insert the strings into hash tables (strings with last 4 characters
- and strings with last character equal), look for longer strings which
- we're suffix of. */
- for (a = array, end = array + sinfo->htab->size; a < end; a++)
+ if (sinfo->htab->size != 0)
{
- register hashval_t hash;
- unsigned int c;
- unsigned int i;
- const unsigned char *s;
- void **p;
-
- e = *a;
- e->u.entsize = sinfo->htab->entsize;
- if (e->len <= e->u.entsize)
- break;
- if (e->len > 4 * e->u.entsize)
+ qsort (array, (size_t) sinfo->htab->size,
+ sizeof (struct sec_merge_hash_entry *),
+ (alignment != (unsigned) -1 && alignment > sinfo->htab->entsize
+ ? strrevcmp_align : strrevcmp));
+
+ /* Loop over the sorted array and merge suffixes */
+ e = *--a;
+ e->len += sinfo->htab->entsize;
+ while (--a >= array)
{
- s = (const unsigned char *) (e->root.string + e->len - e->u.entsize);
- hash = 0;
- for (i = 0; i < 4 * e->u.entsize; i++)
- {
- c = *--s;
- hash += c + (c << 17);
- hash ^= hash >> 2;
- }
- p = htab_find_slot_with_hash (last4tab, e, hash, INSERT);
- if (p == NULL)
- goto alloc_failure;
- if (*p)
- {
- struct sec_merge_hash_entry *ent;
+ struct sec_merge_hash_entry *cmp = *a;
- ent = (struct sec_merge_hash_entry *) *p;
- e->u.suffix = ent;
- e->alignment = 0;
- continue;
+ cmp->len += sinfo->htab->entsize;
+ if (e->alignment >= cmp->alignment
+ && !((e->len - cmp->len) & (cmp->alignment - 1))
+ && is_suffix (e, cmp))
+ {
+ cmp->u.suffix = e;
+ cmp->alignment = 0;
}
else
- *p = e;
- }
- s = (const unsigned char *) (e->root.string + e->len - e->u.entsize);
- hash = 0;
- for (i = 0; i < e->u.entsize; i++)
- {
- c = *--s;
- hash += c + (c << 17);
- hash ^= hash >> 2;
+ e = cmp;
}
- p = htab_find_slot_with_hash (lasttab, e, hash, INSERT);
- if (p == NULL)
- goto alloc_failure;
- if (*p)
- {
- struct sec_merge_hash_entry *ent;
-
- ent = (struct sec_merge_hash_entry *) *p;
- e->u.suffix = ent;
- e->alignment = 0;
- }
- else
- *p = e;
}
alloc_failure:
if (array)
free (array);
- if (lasttab)
- htab_delete (lasttab);
- if (last4tab)
- htab_delete (last4tab);
/* Now assign positions to the strings we want to keep. */
size = 0;
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