return last;
}
-/* This function is called for each input file before the .eh_frame
- section is relocated. It discards duplicate CIEs and FDEs for discarded
- functions. The function returns TRUE iff any entries have been
- deleted. */
+/* Called before calling _bfd_elf_parse_eh_frame on every input bfd's
+ .eh_frame section. */
-bfd_boolean
-_bfd_elf_discard_section_eh_frame
- (bfd *abfd, struct bfd_link_info *info, asection *sec,
- bfd_boolean (*reloc_symbol_deleted_p) (bfd_vma, void *),
- struct elf_reloc_cookie *cookie)
+void
+_bfd_elf_begin_eh_frame_parsing (struct bfd_link_info *info)
+{
+ struct eh_frame_hdr_info *hdr_info;
+
+ hdr_info = &elf_hash_table (info)->eh_info;
+ if (!hdr_info->parsed_eh_frames && !info->relocatable)
+ hdr_info->cies = htab_try_create (1, cie_hash, cie_eq, free);
+}
+
+/* Try to parse .eh_frame section SEC, which belongs to ABFD. Store the
+ information in the section's sec_info field on success. COOKIE
+ describes the relocations in SEC. */
+
+void
+_bfd_elf_parse_eh_frame (bfd *abfd, struct bfd_link_info *info,
+ asection *sec, struct elf_reloc_cookie *cookie)
{
#define REQUIRE(COND) \
do \
goto free_no_table; \
while (0)
- bfd_byte *ehbuf = NULL, *buf;
+ bfd_byte *ehbuf = NULL, *buf, *end;
bfd_byte *last_fde;
- struct eh_cie_fde *ent, *this_inf;
+ struct eh_cie_fde *this_inf;
unsigned int hdr_length, hdr_id;
struct extended_cie
{
- struct cie cie;
- unsigned int offset;
- unsigned int usage_count;
- unsigned int entry;
+ struct cie *cie;
+ struct eh_cie_fde *local_cie;
} *ecies = NULL, *ecie;
- unsigned int ecie_count = 0, ecie_alloced = 0;
- struct cie *cie;
+ unsigned int ecie_count;
+ struct cie *cie, *local_cies = NULL, tmp_cie;
struct elf_link_hash_table *htab;
struct eh_frame_hdr_info *hdr_info;
struct eh_frame_sec_info *sec_info = NULL;
- unsigned int offset;
unsigned int ptr_size;
- unsigned int entry_alloced;
+ unsigned int num_cies;
+ unsigned int num_entries;
+
+ htab = elf_hash_table (info);
+ hdr_info = &htab->eh_info;
+ if (hdr_info->parsed_eh_frames)
+ return;
if (sec->size == 0)
{
/* This file does not contain .eh_frame information. */
- return FALSE;
+ return;
}
if (bfd_is_abs_section (sec->output_section))
{
/* At least one of the sections is being discarded from the
link, so we should just ignore them. */
- return FALSE;
+ return;
}
- htab = elf_hash_table (info);
- hdr_info = &htab->eh_info;
-
- if (hdr_info->cies == NULL && !info->relocatable)
- hdr_info->cies = htab_try_create (1, cie_hash, cie_eq, free);
-
/* Read the frame unwind information from abfd. */
REQUIRE (bfd_malloc_and_get_section (abfd, sec, &ehbuf));
{
/* Empty .eh_frame section. */
free (ehbuf);
- return FALSE;
+ return;
}
/* If .eh_frame section size doesn't fit into int, we cannot handle
->elf_backend_eh_frame_address_size (abfd, sec));
REQUIRE (ptr_size != 0);
+ /* Go through the section contents and work out how many FDEs and
+ CIEs there are. */
buf = ehbuf;
+ end = ehbuf + sec->size;
+ num_cies = 0;
+ num_entries = 0;
+ while (buf != end)
+ {
+ num_entries++;
+
+ /* Read the length of the entry. */
+ REQUIRE (skip_bytes (&buf, end, 4));
+ hdr_length = bfd_get_32 (abfd, buf - 4);
+
+ /* 64-bit .eh_frame is not supported. */
+ REQUIRE (hdr_length != 0xffffffff);
+ if (hdr_length == 0)
+ break;
+
+ REQUIRE (skip_bytes (&buf, end, 4));
+ hdr_id = bfd_get_32 (abfd, buf - 4);
+ if (hdr_id == 0)
+ num_cies++;
+
+ REQUIRE (skip_bytes (&buf, end, hdr_length - 4));
+ }
+
sec_info = bfd_zmalloc (sizeof (struct eh_frame_sec_info)
- + 99 * sizeof (struct eh_cie_fde));
+ + (num_entries - 1) * sizeof (struct eh_cie_fde));
REQUIRE (sec_info);
- entry_alloced = 100;
+ ecies = bfd_zmalloc (num_cies * sizeof (*ecies));
+ REQUIRE (ecies);
+
+ /* If we're not merging CIE entries (such as for a relocatable link),
+ we need to have a "struct cie" for each CIE in this section. */
+ if (hdr_info->cies == NULL)
+ {
+ local_cies = bfd_zmalloc (num_cies * sizeof (*local_cies));
+ REQUIRE (local_cies);
+ }
#define ENSURE_NO_RELOCS(buf) \
REQUIRE (!(cookie->rel < cookie->relend \
== (bfd_size_type) ((buf) - ehbuf))) \
? cookie->rel : NULL)
- for (;;)
+ buf = ehbuf;
+ ecie_count = 0;
+ while ((bfd_size_type) (buf - ehbuf) != sec->size)
{
char *aug;
- bfd_byte *start, *end, *insns, *insns_end;
+ bfd_byte *start, *insns, *insns_end;
bfd_size_type length;
unsigned int set_loc_count;
- if (sec_info->count == entry_alloced)
- {
- sec_info = bfd_realloc (sec_info,
- sizeof (struct eh_frame_sec_info)
- + ((entry_alloced + 99)
- * sizeof (struct eh_cie_fde)));
- REQUIRE (sec_info);
-
- memset (&sec_info->entry[entry_alloced], 0,
- 100 * sizeof (struct eh_cie_fde));
- entry_alloced += 100;
- }
-
this_inf = sec_info->entry + sec_info->count;
last_fde = buf;
- if ((bfd_size_type) (buf - ehbuf) == sec->size)
- break;
-
/* Read the length of the entry. */
REQUIRE (skip_bytes (&buf, ehbuf + sec->size, 4));
hdr_length = bfd_get_32 (abfd, buf - 4);
- /* 64-bit .eh_frame is not supported. */
- REQUIRE (hdr_length != 0xffffffff);
-
/* The CIE/FDE must be fully contained in this input section. */
REQUIRE ((bfd_size_type) (buf - ehbuf) + hdr_length <= sec->size);
end = buf + hdr_length;
/* CIE */
this_inf->cie = 1;
- if (ecie_count == ecie_alloced)
+ /* If we're merging CIEs, construct the struct cie in TMP_CIE;
+ we'll enter it into the global pool later. Otherwise point
+ CIE to one of the section-local cie structures. */
+ if (local_cies)
+ cie = local_cies + ecie_count;
+ else
{
- ecies = bfd_realloc (ecies,
- (ecie_alloced + 20) * sizeof (*ecies));
- REQUIRE (ecies);
- memset (&ecies[ecie_alloced], 0, 20 * sizeof (*ecies));
- ecie_alloced += 20;
+ cie = &tmp_cie;
+ memset (cie, 0, sizeof (*cie));
}
-
- cie = &ecies[ecie_count].cie;
- ecies[ecie_count].offset = this_inf->offset;
- ecies[ecie_count++].entry = sec_info->count;
+ cie->cie_inf = this_inf;
cie->length = hdr_length;
+ cie->output_sec = sec->output_section;
start = buf;
REQUIRE (read_byte (&buf, end, &cie->version));
insns = buf;
buf += initial_insn_length;
ENSURE_NO_RELOCS (buf);
+
+ this_inf->make_relative = cie->make_relative;
+ this_inf->make_lsda_relative = cie->make_lsda_relative;
+ this_inf->per_encoding_relative
+ = (cie->per_encoding & 0x70) == DW_EH_PE_pcrel;
}
else
{
/* Find the corresponding CIE. */
unsigned int cie_offset = this_inf->offset + 4 - hdr_id;
for (ecie = ecies; ecie < ecies + ecie_count; ++ecie)
- if (cie_offset == ecie->offset)
+ if (cie_offset == ecie->local_cie->offset)
break;
/* Ensure this FDE references one of the CIEs in this input
section. */
REQUIRE (ecie != ecies + ecie_count);
- cie = &ecie->cie;
+ cie = ecie->cie;
+ this_inf->u.fde.cie_inf = ecie->local_cie;
ENSURE_NO_RELOCS (buf);
REQUIRE (GET_RELOC (buf));
- if ((*reloc_symbol_deleted_p) (buf - ehbuf, cookie))
- /* This is a FDE against a discarded section. It should
- be deleted. */
- this_inf->removed = 1;
- else
- {
- if (info->shared
- && (((cie->fde_encoding & 0xf0) == DW_EH_PE_absptr
- && cie->make_relative == 0)
- || (cie->fde_encoding & 0xf0) == DW_EH_PE_aligned))
- {
- /* If a shared library uses absolute pointers
- which we cannot turn into PC relative,
- don't create the binary search table,
- since it is affected by runtime relocations. */
- hdr_info->table = FALSE;
- (*info->callbacks->einfo)
- (_("%P: fde encoding in %B(%A) prevents .eh_frame_hdr"
- " table being created.\n"), abfd, sec);
- }
- ecie->usage_count++;
- hdr_info->fde_count++;
- this_inf->u.fde.cie_inf = (void *) (ecie - ecies);
- }
-
/* Skip the initial location and address range. */
start = buf;
length = get_DW_EH_PE_width (cie->fde_encoding, ptr_size);
}
}
+ this_inf->removed = 1;
this_inf->fde_encoding = cie->fde_encoding;
this_inf->lsda_encoding = cie->lsda_encoding;
+ if (this_inf->cie)
+ {
+ /* We have now finished constructing the struct cie. */
+ if (hdr_info->cies != NULL)
+ {
+ /* See if we can merge this CIE with an earlier one. */
+ void **loc;
+
+ cie_compute_hash (cie);
+ loc = htab_find_slot_with_hash (hdr_info->cies, cie,
+ cie->hash, INSERT);
+ REQUIRE (loc);
+ if (*loc == HTAB_EMPTY_ENTRY)
+ {
+ *loc = malloc (sizeof (struct cie));
+ REQUIRE (*loc);
+ memcpy (*loc, cie, sizeof (struct cie));
+ }
+ cie = (struct cie *) *loc;
+ }
+ this_inf->u.cie.merged = cie->cie_inf;
+ ecies[ecie_count].cie = cie;
+ ecies[ecie_count++].local_cie = this_inf;
+ }
sec_info->count++;
}
+ BFD_ASSERT (sec_info->count == num_entries);
+ BFD_ASSERT (ecie_count == num_cies);
elf_section_data (sec)->sec_info = sec_info;
sec->sec_info_type = ELF_INFO_TYPE_EH_FRAME;
+ goto success;
- /* Look at all CIEs in this section and determine which can be
- removed as unused, which can be merged with previous duplicate
- CIEs and which need to be kept. */
- for (ecie = ecies; ecie < ecies + ecie_count; ++ecie)
- {
- if (ecie->usage_count == 0)
- {
- sec_info->entry[ecie->entry].removed = 1;
- continue;
- }
- ecie->cie.output_sec = sec->output_section;
- ecie->cie.cie_inf = sec_info->entry + ecie->entry;
- cie_compute_hash (&ecie->cie);
- if (hdr_info->cies != NULL)
- {
- void **loc = htab_find_slot_with_hash (hdr_info->cies, &ecie->cie,
- ecie->cie.hash, INSERT);
- if (loc != NULL)
- {
- if (*loc != HTAB_EMPTY_ENTRY)
- {
- sec_info->entry[ecie->entry].removed = 1;
- ecie->cie.cie_inf = ((struct cie *) *loc)->cie_inf;
- continue;
- }
+ free_no_table:
+ (*info->callbacks->einfo)
+ (_("%P: error in %B(%A); no .eh_frame_hdr table will be created.\n"),
+ abfd, sec);
+ hdr_info->table = FALSE;
+ if (sec_info)
+ free (sec_info);
+ success:
+ if (ehbuf)
+ free (ehbuf);
+ if (ecies)
+ free (ecies);
+ if (local_cies)
+ free (local_cies);
+#undef REQUIRE
+}
- *loc = malloc (sizeof (struct cie));
- if (*loc == NULL)
- *loc = HTAB_DELETED_ENTRY;
- else
- memcpy (*loc, &ecie->cie, sizeof (struct cie));
- }
- }
- ecie->cie.cie_inf->make_relative = ecie->cie.make_relative;
- ecie->cie.cie_inf->make_lsda_relative = ecie->cie.make_lsda_relative;
- ecie->cie.cie_inf->per_encoding_relative
- = (ecie->cie.per_encoding & 0x70) == DW_EH_PE_pcrel;
+/* Finish a pass over all .eh_frame sections. */
+
+void
+_bfd_elf_end_eh_frame_parsing (struct bfd_link_info *info)
+{
+ struct eh_frame_hdr_info *hdr_info;
+
+ hdr_info = &elf_hash_table (info)->eh_info;
+ if (hdr_info->cies != NULL)
+ {
+ htab_delete (hdr_info->cies);
+ hdr_info->cies = NULL;
}
+ hdr_info->parsed_eh_frames = TRUE;
+}
- /* Ok, now we can assign new offsets. */
- offset = 0;
+/* This function is called for each input file before the .eh_frame
+ section is relocated. It discards duplicate CIEs and FDEs for discarded
+ functions. The function returns TRUE iff any entries have been
+ deleted. */
+
+bfd_boolean
+_bfd_elf_discard_section_eh_frame
+ (bfd *abfd, struct bfd_link_info *info, asection *sec,
+ bfd_boolean (*reloc_symbol_deleted_p) (bfd_vma, void *),
+ struct elf_reloc_cookie *cookie)
+{
+ struct eh_cie_fde *ent, *cie, *merged;
+ struct eh_frame_sec_info *sec_info;
+ struct eh_frame_hdr_info *hdr_info;
+ unsigned int ptr_size, offset;
+
+ sec_info = (struct eh_frame_sec_info *) elf_section_data (sec)->sec_info;
+ if (sec_info == NULL)
+ return FALSE;
+
+ hdr_info = &elf_hash_table (info)->eh_info;
for (ent = sec_info->entry; ent < sec_info->entry + sec_info->count; ++ent)
- if (!ent->removed)
+ if (!ent->cie)
{
- if (!ent->cie)
+ cookie->rel = cookie->rels + ent->reloc_index;
+ BFD_ASSERT (cookie->rel < cookie->relend
+ && cookie->rel->r_offset == ent->offset + 8);
+ if (!(*reloc_symbol_deleted_p) (ent->offset + 8, cookie))
{
- ecie = ecies + (bfd_hostptr_t) ent->u.fde.cie_inf;
- ent->u.fde.cie_inf = ecie->cie.cie_inf;
+ if (info->shared
+ && (((ent->fde_encoding & 0xf0) == DW_EH_PE_absptr
+ && ent->u.fde.cie_inf->make_relative == 0)
+ || (ent->fde_encoding & 0xf0) == DW_EH_PE_aligned))
+ {
+ /* If a shared library uses absolute pointers
+ which we cannot turn into PC relative,
+ don't create the binary search table,
+ since it is affected by runtime relocations. */
+ hdr_info->table = FALSE;
+ (*info->callbacks->einfo)
+ (_("%P: fde encoding in %B(%A) prevents .eh_frame_hdr"
+ " table being created.\n"), abfd, sec);
+ }
+ ent->removed = 0;
+ hdr_info->fde_count++;
+
+ cie = ent->u.fde.cie_inf;
+ if (cie->removed)
+ {
+ merged = cie->u.cie.merged;
+ if (!merged->removed)
+ /* We have decided to keep the group representative. */
+ ent->u.fde.cie_inf = merged;
+ else if (merged->u.cie.merged != merged)
+ /* We didn't keep the original group representative,
+ but we did keep an alternative. */
+ ent->u.fde.cie_inf = merged->u.cie.merged;
+ else
+ {
+ /* Make the local CIE represent the merged group. */
+ merged->u.cie.merged = cie;
+ cie->removed = 0;
+ }
+ }
}
+ }
+
+ ptr_size = (get_elf_backend_data (sec->owner)
+ ->elf_backend_eh_frame_address_size (sec->owner, sec));
+ offset = 0;
+ for (ent = sec_info->entry; ent < sec_info->entry + sec_info->count; ++ent)
+ if (!ent->removed)
+ {
ent->new_offset = offset;
offset += size_of_output_cie_fde (ent, ptr_size);
}
- /* Resize the sec as needed. */
sec->rawsize = sec->size;
sec->size = offset;
-
- free (ehbuf);
- if (ecies)
- free (ecies);
return offset != sec->rawsize;
-
-free_no_table:
- (*info->callbacks->einfo)
- (_("%P: error in %B(%A); no .eh_frame_hdr table will be created.\n"),
- abfd, sec);
- if (ehbuf)
- free (ehbuf);
- if (sec_info)
- free (sec_info);
- if (ecies)
- free (ecies);
- hdr_info->table = FALSE;
- return FALSE;
-
-#undef REQUIRE
}
/* This function is called for .eh_frame_hdr section after
htab = elf_hash_table (info);
hdr_info = &htab->eh_info;
- if (hdr_info->cies != NULL)
- {
- htab_delete (hdr_info->cies);
- hdr_info->cies = NULL;
- }
-
sec = hdr_info->hdr_sec;
if (sec == NULL)
return FALSE;
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