* elfcode.h (elf_object_p): Allow files with corrupt e_shstrndx fields to
still be handled as ELF files.
* readelf.c (SECTION_NAME): Cope with a missing string table.
(process_file_header): Cope with a corrupt e_shstrndx field.
(process_section_headers): Correctly handle an e_shstrndx value of SHF_UNDEF.
(compute_text_actions): Use it to decode opcodes outside inner loop.
(check_section_ebb_pcrels_fit): Add "reloc_opcodes" argument, and if
it is set, use it to get the opcodes for relocations.
(move_shared_literal): Adjust call to check_section_ebb_pcrels_fit.
PR ld/2513
* elf32-i386.c (GOT_TLS_MASK): New macro for tls_type.
(GOT_TLS_IE_IE): Likewise.
(GOT_TLS_IE_GD): Likewise.
(GOT_TLS_IE_MASK): Likewise.
(elf_i386_check_relocs): For global symbols, set GOT_TLS_IE_GD
and GOT_TLS_IE_IE for R_386_TLS_GD and R_386_TLS_IE
respectively.
(allocate_dynrelocs): If both GOT_TLS_IE_IE and GOT_TLS_IE_GD
are set, treat tls_type as GOT_TLS_IE_BOTH.
(elf_i386_relocate_section): Likewise.
2006-04-06 H.J. Lu <hongjiu.lu@intel.com>
* elfxx-ia64.c (elfNN_ia64_relax_section): Skip unneeded passes
with the skip_relax_pass_0 and skip_relax_pass_1 bits in the
section structure.
include/
2006-04-06 H.J. Lu <hongjiu.lu@intel.com>
* bfdlink.h (bfd_link_info): Replace need_relax_finalize with
relax_pass.
ld/
2006-04-06 H.J. Lu <hongjiu.lu@intel.com>
* emultempl/ia64elf.em: Set link_info.relax_pass to 2. Remove
link_info.need_relax_finalize.
* ldlang.c (relax_sections): New.
(lang_process): Use. Call relax_sections link_info.relax_pass
times.
* ldmain.c (main): Set link_info.relax_pass to 1. Remove
link_info.need_relax_finalize.
James E Wilson <wilson@specifixinc.com>
PR ld/2442
* elfxx-ia64.c (elfNN_ia64_dyn_sym_info): Remove next.
(elfNN_ia64_local_hash_entry): Add count, sorted_count and
size.
(elfNN_ia64_link_hash_entry): Likewise.
(elfNN_ia64_new_elf_hash_entry): Initialize count, sorted_count
and size.
(elfNN_ia64_hash_copy_indirect): Updated elfNN_ia64_dyn_sym_info
processing.
(elfNN_ia64_hash_hide_symbol): Likewise.
(elfNN_ia64_global_dyn_sym_thunk): Likewise.
(elfNN_ia64_local_dyn_sym_thunk): Likewise.
(elfNN_ia64_global_dyn_info_free): New function.
(elfNN_ia64_local_dyn_info_free): Likewise.
(elfNN_ia64_hash_table_free): Free local and global
elfNN_ia64_dyn_sym_info.
(addend_compare): New function.
(sort_dyn_sym_info): Likewise.
(get_dyn_sym_info): Updated to use binary search for addend.
(elfNN_ia64_check_relocs): Scan relocations to create dynamic
relocation arrays first.
PR ld/2404
* elflink.c (_bfd_elf_merge_symbol): Skip the default indirect
symbol from the dynamic definition with the default version if
its type and the type of existing regular definition mismatch.
(mips_elf_local_got_index): Use the hash table entry to record
the GOT index of forced-local symbols.
(mips_elf_initialize_tls_index): Rearrange code. Store the index
in either the hash table entry or the mips_got_entry, not both.
Add more commentary.
(mips_elf_multi_got): Make sure the g->next is nonnull when calling
mips_elf_initialize_tls_index.
* ld-mips-elf/tls-hidden3a.s, ld-mips-elf/tls-hidden3b.s,
* ld-mips-elf/tls-hidden3.d, ld-mips-elf/tls-hidden3.got,
* ld-mips-elf/tls-hidden3.ld, ld-mips-elf/tls-hidden3.r,
* ld-mips-elf/tls-hidden4a.s, ld-mips-elf/tls-hidden4b.s,
* ld-mips-elf/tls-hidden4.got, ld-mips-elf/tls-hidden4.r: New tests.
* ld-mips-elf/mips-elf.exp: Run them.
* cpu-m68k.c (bfd_m68k_compatible): Treat ISA A+ and ISA B code as
incompatible. Likewise MAC and EMAC code.
* elf32-m68k.c (elf32_m68k_merge_private_bfd_data): Use
bfd_get_compatible to set the new bfd architecture. Rely on it
to detect incompatibilities.
gas/
* config/tc-m68k.c (m68k_cpus): Change cpu_cf5208 entries to use
mcfemac instead of mcfmac.
ld/testsuite/
* ld-m68k/merge-error-1a.s, ld-m68k/merge-error-1b.s,
* ld-m68k/merge-error-1a.d, ld-m68k/merge-error-1b.d,
* ld-m68k/merge-error-1c.d, ld-m68k/merge-error-1d.d,
* ld-m68k/merge-error-1e.d, ld-m68k/merge-ok-1a.d,
* ld-m68k/merge-ok-1b.d: New tests.
* ld-m68k/m68k.exp: Run them.
Daniel Jacobowitz <dan@codesourcery.com>
Phil Edwards <phil@codesourcery.com>
Zack Weinberg <zack@codesourcery.com>
Mark Mitchell <mark@codesourcery.com>
Nathan Sidwell <nathan@codesourcery.com>
bfd/
* bfd-in2.h: Regenerate.
* config.bfd (mips*-*-vxworks*, mips*el-*-vxworks*): New stanzas.
* configure.in (bfd_elf32_bigmips_vxworks_vec): New stanza.
(bfd_elf32_littlemips_vxworks_vec): Likewise.
(bfd_elf32_bigmips_vec): Add elf-vxworks.lo.
(bfd_elf32_littlemips_vec): Likewise.
(bfd_elf32_nbigmips_vec): Likewise.
(bfd_elf32_nlittlemips_vec): Likewise.
(bfd_elf32_ntradbigmips_vec): Likewise.
(bfd_elf32_ntradlittlemips_vec): Likewise.
(bfd_elf32_tradbigmips_vec): Likewise.
(bfd_elf32_tradlittlemips_vec): Likewise.
(bfd_elf64_bigmips_vec): Likewise.
(bfd_elf64_littlemips_vec): Likewise.
(bfd_elf64_tradbigmips_vec): Likewise.
(bfd_elf64_tradlittlemips_vec): Likewise.
* elf32-mips.c: Include elf-vxworks.h.
(mips_info_to_howto_rel): Use elf_backend_mips_rtype_to_howto
instead of calling mips_elf32_rtype_to_howto directly.
(mips_vxworks_copy_howto_rela): New reloc howto.
(mips_vxworks_jump_slot_howto_rela): Likewise.
(mips_vxworks_bfd_reloc_type_lookup): New function.
(mips_vxworks_rtype_to_howto): Likewise.
(mips_vxworks_final_write_processing): Likewise.
(TARGET_LITTLE_SYM, TARGET_LITTLE_NAME): Override for VxWorks.
(TARGET_BIG_SYM, TARGET_BIG_NAME, elf_bed, ELF_MAXPAGESIZE): Likewise.
(elf_backend_want_got_plt): Likewise.
(elf_backend_want_plt_sym): Likewise.
(elf_backend_got_symbol_offset): Likewise.
(elf_backend_want_dynbss): Likewise.
(elf_backend_may_use_rel_p): Likewise.
(elf_backend_may_use_rela_p): Likewise.
(elf_backend_default_use_rela_p): Likewise.
(elf_backend_got_header_size: Likewise.
(elf_backend_plt_readonly): Likewise.
(bfd_elf32_bfd_reloc_type_lookup): Likewise.
(elf_backend_mips_rtype_to_howto): Likewise.
(elf_backend_adjust_dynamic_symbol): Likewise.
(elf_backend_finish_dynamic_symbol): Likewise.
(bfd_elf32_bfd_link_hash_table_create): Likewise.
(elf_backend_add_symbol_hook): Likewise.
(elf_backend_link_output_symbol_hook): Likewise.
(elf_backend_emit_relocs): Likewise.
(elf_backend_final_write_processing: Likewise.
(elf_backend_additional_program_headers): Likewise.
(elf_backend_modify_segment_map): Likewise.
(elf_backend_symbol_processing): Likewise.
* elfxx-mips.c: Include elf-vxworks.h.
(mips_elf_link_hash_entry): Add is_relocation_target and
is_branch_target fields.
(mips_elf_link_hash_table): Add is_vxworks, srelbss, sdynbss, srelplt,
srelplt2, sgotplt, splt, plt_header_size and plt_entry_size fields.
(MIPS_ELF_RELA_SIZE, MIPS_ELF_REL_DYN_NAME): New macros.
(MIPS_RESERVED_GOTNO): Take a mips_elf_link_hash_table argument.
Return 3 for VxWorks.
(ELF_MIPS_GP_OFFSET): Change the argument from a bfd to a
mips_elf_link_hash_table. Return 0 for VxWorks.
(MIPS_ELF_GOT_MAX_SIZE): Change the argument from a bfd to a
mips_elf_link_hash_table. Update the call to ELF_MIPS_GP_OFFSET.
(mips_vxworks_exec_plt0_entry): New variable.
(mips_vxworks_exec_plt_entry): Likewise.
(mips_vxworks_shared_plt0_entry): Likewise.
(mips_vxworks_shared_plt_entry): Likewise.
(mips_elf_link_hash_newfunc): Initialize the new hash_entry fields.
(mips_elf_rel_dyn_section): Change the bfd argument to a
mips_elf_link_hash_table. Use MIPS_ELF_REL_DYN_NAME to get
the name of the section.
(mips_elf_initialize_tls_slots): Update the call to
mips_elf_rel_dyn_section.
(mips_elf_gotplt_index): New function.
(mips_elf_local_got_index): Add an input_section argument.
Update the call to mips_elf_create_local_got_entry.
(mips_elf_got_page): Likewise.
(mips_elf_got16_entry): Likewise.
(mips_elf_create_local_got_entry): Add bfd_link_info and input_section
arguments. Create dynamic relocations for each entry on VxWorks.
(mips_elf_merge_gots): Update the use of MIPS_ELF_GOT_MAX_SIZE.
(mips_elf_multi_got): Update the uses of MIPS_ELF_GOT_MAX_SIZE
and MIPS_RESERVED_GOTNO.
(mips_elf_create_got_section): Update the uses of
MIPS_ELF_GOT_MAX_SIZE. Create .got.plt on VxWorks.
(is_gott_symbol): New function.
(mips_elf_calculate_relocation): Use a dynobj local variable.
Update the calls to mips_elf_local_got_index, mips_elf_got16_entry and
mips_elf_got_page_entry. Set G to the .got.plt entry when calculating
VxWorks R_MIPS_CALL* relocations. Calculate and use G for all GOT
relocations on VxWorks. Add dynamic relocations for references
to the VxWorks __GOTT_BASE__ and __GOTT_INDEX__ symbols. Don't
create dynamic relocations for R_MIPS_32, R_MIPS_REL32 or R_MIPS_64
in VxWorks executables.
(mips_elf_allocate_dynamic_relocations): Add a bfd_link_info argument.
Use MIPS_ELF_RELA_SIZE to calculate the size of a VxWorks entry.
Don't allocate a null entry on VxWorks.
(mips_elf_create_dynamic_relocation): Update the call to
mips_elf_rel_dyn_section. Use absolute rather than relative
relocations for VxWorks, and make them RELA rather than REL.
(_bfd_mips_elf_create_dynamic_sections): Don't make .dynamic
read-only on VxWorks. Update the call to mips_elf_rel_dyn_section.
Create the .plt, .rela.plt, .dynbss and .rela.bss sections on
VxWorks. Likewise create the _PROCEDURE_LINKAGE_TABLE symbol.
Call elf_vxworks_create_dynamic_sections for VxWorks and
initialize the plt_header_size and plt_entry_size fields.
(_bfd_mips_elf_check_relocs): Don't allow GOT relocations to be
used in VxWorks executables. Don't allocate dynamic relocations
for R_MIPS_32, R_MIPS_REL32 or R_MIPS_64 in VxWorks executables.
Set is_relocation_target for each symbol referenced by a relocation.
Allocate .rela.dyn entries for relocations against the special
VxWorks __GOTT_BASE__ and __GOTT_INDEX__ symbols. Create GOT
entries for all VxWorks R_MIPS_GOT16 relocations. Don't allocate
a global GOT entry for symbols mentioned in VxWorks R_MIPS_CALL*,
R_MIPS_32, R_MIPS_REL32 or R_MIPS_64 relocations. Update the calls
to mips_elf_rel_dyn_section and mips_elf_allocate_dynamic_relocations.
Set is_branch_target for symbols mentioned in R_MIPS_PC16 or R_MIPS_26
relocations. Don't set no_fn_stub on VxWorks.
(_bfd_mips_elf_adjust_dynamic_symbol): Update the call to
mips_elf_allocate_dynamic_relocations.
(_bfd_mips_vxworks_adjust_dynamic_symbol): New function.
(_bfd_mips_elf_always_size_sections): Do not allocate GOT page
entries for VxWorks, and do not create multiple GOTs.
(_bfd_mips_elf_size_dynamic_sections): Use MIPS_ELF_REL_DYN_NAME.
Handle .got specially for VxWorks. Update the uses of
MIPS_RESERVED_GOTNO and mips_elf_allocate_dynamic_relocations.
Check for sgotplt and splt. Allocate the .rel(a).dyn contents last,
once its final size is known. Set DF_TEXTREL for VxWorks. Add
DT_RELA, DT_RELASZ, DT_RELAENT, DT_PLTREL, DT_PLTRELSZ and DT_JMPREL
tags on VxWorks. Do not add the MIPS-specific tags for VxWorks.
(_bfd_mips_vxworks_finish_dynamic_symbol): New function.
(mips_vxworks_finish_exec_plt): Likewise.
(mips_vxworks_finish_shared_plt): Likewise.
(_bfd_mips_elf_finish_dynamic_sections): Remove an unncessary call
to mips_elf_rel_dyn_section. Use a VxWorks-specific value of
DT_PLTGOT. Handle DT_RELA, DT_RELASZ, DT_RELAENT, DT_PLTREL,
DT_PLTRELSZ and DT_JMPREL. Update the uses of MIPS_RESERVED_GOTNO
and mips_elf_rel_dyn_section. Use a different GOT header for
VxWorks. Don't sort .rela.dyn on VxWorks. Finish the PLT on VxWorks.
(_bfd_mips_elf_link_hash_table_create): Initialize the new
mips_elf_link_hash_table fields.
(_bfd_mips_vxworks_link_hash_table_create): New function.
(_bfd_mips_elf_final_link): Set the GP value to _GLOBAL_OFFSET_TABLE_
on VxWorks. Update the call to ELF_MIPS_GP_OFFSET.
* elfxx-mips.h (_bfd_mips_vxworks_adjust_dynamic_symbol): Declare.
(_bfd_mips_vxworks_finish_dynamic_symbol): Likewise.
(_bfd_mips_vxworks_link_hash_table_create): Likewise.
* libbfd.h: Regenerate.
* Makefile.am (elfxx-mips.lo): Depend on elf-vxworks.h.
(elf32-mips.lo): Likewise.
* Makefile.in: Regenerate.
* reloc.c (BFD_RELOC_MIPS_COPY, BFD_RELOC_MIPS_JUMP_SLOT): Declare.
* targets.c (bfd_elf32_bigmips_vxworks_vec): Declare.
(bfd_elf32_littlemips_vxworks_vec): Likewise.
(_bfd_target_vector): Add entries for them.
gas/
* config/tc-mips.c (mips_target_format): Handle vxworks targets.
(md_begin): Complain about -G being used for PIC. Don't change
the text, data and bss alignments on VxWorks.
(reloc_needs_lo_p): Don't return true for R_MIPS_GOT16 when
generating VxWorks PIC.
(load_address): Extend SVR4_PIC handling to VXWORKS_PIC.
(macro): Likewise, but do not treat la $25 specially for
VxWorks PIC, and do not handle jal.
(OPTION_MVXWORKS_PIC): New macro.
(md_longopts): Add -mvxworks-pic.
(md_parse_option): Don't complain about using PIC and -G together here.
Handle OPTION_MVXWORKS_PIC.
(md_estimate_size_before_relax): Always use the first relaxation
sequence on VxWorks.
* config/tc-mips.h (VXWORKS_PIC): New.
gas/testsuite/
* gas/mips/vxworks1.s, gas/mips/vxworks1.d,
* gas/mips/vxworks1-xgot.d: New tests.
* gas/mips/mips.exp: Run them. Do not run other tests on VxWorks.
include/elf/
* mips.h (R_MIPS_COPY, R_MIPS_JUMP_SLOT): New relocs.
ld/
* configure.tgt (mips*el-*-vxworks*, mips*-*-vxworks*): Use
separate VxWorks emulations.
* emulparams/elf32ebmipvxworks.sh: New file.
* emulparams/elf32elmipvxworks.sh: New file.
* Makefile.am (ALL_EMULATIONS): Add eelf32ebmipvxworks.o and
eelf32elmipvxworks.o.
(eelf32ebmipvxworks.c, eelf32elmipvxworks.c): New rules.
* Makefile.in: Regenerate.
ld/testsuite/
* ld-mips/vxworks1.dd, ld-mips/vxworks1.ld, ld-mips/vxworks1-lib.dd,
* ld-mips/vxworks1-lib.nd, ld-mips/vxworks1-lib.rd,
* ld-mips/vxworks1-lib.s, ld-mips/vxworks1.rd, ld-mips/vxworks1.s,
* ld-mips/vxworks1-static.d, ld-mips/vxworks2.s, ld-mips/vxworks2.sd,
* ld-mips/vxworks2-static.sd: New tests.
* ld-mips/mips-elf.exp: Run them.
* elf32-ppc.c (ppc_elf_relocate_section): Copy addend from
first relocation to the second when relaxing TLS GD to LE;
zero it out when relaxing to IE.
ld/testsuite/ChangeLog:
* ld-powerpc/tls32.s: Verify that +32768 @plt addend is
discarded.
against __GLOBAL_OFFSET_TABLE__ need never be dynamic. Tweak
last change to REL32 relocs so that they are counted as
possibly dynamic as per REL24 and REL14.
* elf32-mips.c (mips_elf_adjust_addend): New function, mostly split
out from...
(_bfd_mips_elf_relocate_section): ...here. Use it to adjust r_addend
for final links too.
ld/testsuite/
* ld-mips/emit-relocs-1a.s, ld-mips/emit-relocs-1b.s,
* ld-mips/emit-relocs-1.ld, ld-mips/emit-relocs-1.d: New test.
* ld-mips/mips-elf.exp: Run it.
* configure.in (bfd_elf32_bigarm_vec): Include elf-vxworks.lo.
(bfd_elf32_bigarm_symbian_vec): Likewise.
(bfd_elf32_bigarm_vxworks_vec): Likewise.
(bfd_elf32_littlearm_vec): Likewise.
(bfd_elf32_littlearm_symbian_vec): Likewise.
(bfd_elf32_littlearm_vxworks_vec): Likewise.
* configure: Regenerate.
* elf32-arm.c: Include libiberty.h and elf-vxworks.h.
(RELOC_SECTION, RELOC_SIZE, SWAP_RELOC_IN, SWAP_RELOC_OUT): New macros.
(elf32_arm_vxworks_bed): Add forward declaration.
(elf32_arm_howto_table_1): Fix the masks for R_ASM_ABS12.
(elf32_arm_vxworks_exec_plt0_entry): New table.
(elf32_arm_vxworks_exec_plt_entry): Likewise.
(elf32_arm_vxworks_shared_plt_entry): Likewise.
(elf32_arm_link_hash_table): Add vxworks_p and srelplt2 fields.
(reloc_section_p): New function.
(create_got_section): Use RELOC_SECTION.
(elf32_arm_create_dynamic_sections): Likewise. Call
elf_vxworks_create_dynamic_sections for VxWorks targets.
Choose between the two possible values of plt_header_size
and plt_entry_size.
(elf32_arm_link_hash_table_create): Initialize vxworks_p and srelplt2.
(elf32_arm_abs12_reloc): New function.
(elf32_arm_final_link_relocate): Call it. Allow the creation of
dynamic R_ARM_ABS12 relocs on VxWorks. Use reloc_section_p,
RELOC_SIZE, SWAP_RELOC_OUT and RELOC_SECTION. Initialize the
r_addend fields of relocs. On rela targets, skip any code that
adjusts in-place addends. When using _bfd_link_final_relocate
to perform a final relocation, pass rel->r_addend as the addend
argument.
(elf32_arm_merge_private_bfd_data): If one of the bfds is a VxWorks
object, ignore flags that are not standard on VxWorks.
(elf32_arm_check_relocs): Allow the creation of dynamic R_ARM_ABS12
relocs on VxWorks. Use reloc_section_p.
(elf32_arm_adjust_dynamic_symbol): Use RELOC_SECTION and RELOC_SIZE.
(allocate_dynrelocs): Use RELOC_SIZE. Account for the size of
.rela.plt.unloaded relocs on VxWorks targets.
(elf32_arm_size_dynamic_sections): Use RELOC_SIZE. Check for
.rela.plt.unloaded as well as .rel(a).plt. Add DT_RELA* tags
instead of DT_REL* tags on RELA targets.
(elf32_arm_finish_dynamic_symbol): Use RELOC_SECTION, RELOC_SIZE
and SWAP_RELOC_OUT. Initialize r_addend fields. Handle VxWorks
PLT entries. Do not make _GLOBAL_OFFSET_TABLE_ absolute on VxWorks.
(elf32_arm_finish_dynamic_sections): Use RELOC_SECTION, RELOC_SIZE
and SWAP_RELOC_OUT. Initialize r_addend fields. Handle DT_RELASZ
like DT_RELSZ. Handle the VxWorks form of initial PLT entry.
Correct the .rela.plt.unreloaded symbol indexes.
(elf32_arm_output_symbol_hook): Call the VxWorks version of this
hook on VxWorks targets.
(elf32_arm_vxworks_link_hash_table_create): Set vxworks_p to true.
Minor formatting tweak.
(elf32_arm_vxworks_final_write_processing): New function.
(elf_backend_add_symbol_hook): Override for VxWorks and reset
for Symbian.
(elf_backend_final_write_processing): Likewise.
(elf_backend_emit_relocs): Likewise.
(elf_backend_want_plt_sym): Likewise.
(ELF_MAXPAGESIZE): Likewise.
(elf_backend_may_use_rel_p): Minor formatting tweak.
(elf_backend_may_use_rela_p): Likewise.
(elf_backend_default_use_rela_p): Likewise.
(elf_backend_rela_normal): Likewise.
* Makefile.in (elf32-arm.lo): Depend on elf-vxworks.h.
gas/
* config/tc-arm.c (md_apply_fix): Install a value of zero into a
BFD_RELOC_ARM_OFFSET_IMM field if we're going to generate a RELA
R_ARM_ABS12 reloc.
(tc_gen_reloc): Keep the original fx_offset for RELA pc-relative
relocs, but adjust by md_pcrel_from_section. Create R_ARM_ABS12
relocations for BFD_RELOC_ARM_OFFSET_IMM on RELA targets.
gas/testsuite/
* gas/arm/abs12.s, gas/arm/abs12.d: New test.
* gas/arm/pic.d: Skip for *-*-vxworks*...
* gas/arm/pic_vxworks.d: ...use this version instead.
* gas/arm/unwind_vxworks.d: Fix expected output.
ld/
* emulparams/armelf_vxworks.sh: Include vxworks.sh.
(MAXPAGESIZE): Define.
* emulparams/vxworks.sh: Undefine.
* Makefile.am (earmelf_vxworks.c): Depend on vxworks.sh and vxworks.em.
* Makefile.in: Regenerate.
ld/testsuite/
* ld-arm/vxworks1.dd, ld-arm/vxworks1.ld, ld-arm/vxworks1-lib.dd,
* ld-arm/vxworks1-lib.nd, ld-arm/vxworks1-lib.rd,
* ld-arm/vxworks1-lib.s, ld-arm/vxworks1.rd, ld-arm/vxworks1.s,
* ld-arm/vxworks1-static.d, ld-arm/vxworks2.s, ld-arm/vxworks2.sd,
* ld-arm/vxworks2-static.sd: New tests.
* ld-arm/arm-elf.exp: Run them.
H.J. Lu
Alan Modra
Nick Clifton
Daniel Jacobowitz
Bob Wilson
DJ Delorie
Carlos O'Donell
Bernd Schmidt
Richard Sandiford
Ben Elliston
Dave Anglin
Alexandre Oliva
Paul Brook
Nathan Sidwell