PR22471, undefined reference to linker-defined symbols
authorAlan Modra <amodra@gmail.com>
Mon, 27 Nov 2017 03:10:43 +0000 (13:40 +1030)
committerAlan Modra <amodra@gmail.com>
Tue, 28 Nov 2017 12:27:00 +0000 (22:57 +1030)
commit165f707ac88916aedecc96fa518be8879704d6da
tree8ca3d6cbc5f8a0a0154ff5686e71a964a932966d
parentcd5b2babea487b0a71a14b593af98330efd8d73e
PR22471, undefined reference to linker-defined symbols

This patch processes linker script assignment statements before ld
opens DT_NEEDED libraries, in order to define symbols like __bss_start
that might also be defined by a library, falsely triggering an error
about "DSO missing from command line".

The initial value won't be correct when assigning a symbol from dot,
and I make no attempt to handle all expressions.  For example, an
assignment like "_start_foo = ADDR (.foo)" isn't valid until sections
are laid out, so won't define _start_foo early.  What's here should be
enough for most common scripts, and hopefully won't perturb fragile
scripts.

bfd/
PR 22471
* elflink.c (_bfd_elf_merge_symbol): Allow weak symbols to override
early passes over linker script symbols.
* linker.c (_bfd_generic_link_add_one_symbol): Allow symbols to
override early passes over linker script symbols.  Clear ldscript_def
on symbol definitions.
ld/
PR 22471
* ldexp.c (struct definedness_hash_entry): Delete "by_script".  Make
"iteration" an 8-bit field, and update mask in all uses.
(definedness_newfunc): Don't init "by_script".
(update_definedness): Test ldscript_def rather than by_script.
(is_sym_value): Likewise.
(fold_name <DEFINED>): Return a result for first phase.  Test
ldscript_def.
(fold_name <NAME>): Return a result for first phase.
* ldlang.c (open_input_bfds): Process all assignments, not just
defsym.
(lang_process): Increment lang_statement_iteration before
open_input_bfds.
* testsuite/ld-mips-elf/tlsdyn-o32-1.d: Adjust for larger .dynsym.
* testsuite/ld-mips-elf/tlsdyn-o32-1.got: Likewise.
* testsuite/ld-mips-elf/tlsdyn-o32-2.d: Likewise.
* testsuite/ld-mips-elf/tlsdyn-o32-2.got: Likewise.
* testsuite/ld-mips-elf/tlsdyn-o32-3.d: Likewise.
* testsuite/ld-mips-elf/tlsdyn-o32-3.got: Likewise.
12 files changed:
bfd/ChangeLog
bfd/elflink.c
bfd/linker.c
ld/ChangeLog
ld/ldexp.c
ld/ldlang.c
ld/testsuite/ld-mips-elf/tlsdyn-o32-1.d
ld/testsuite/ld-mips-elf/tlsdyn-o32-1.got
ld/testsuite/ld-mips-elf/tlsdyn-o32-2.d
ld/testsuite/ld-mips-elf/tlsdyn-o32-2.got
ld/testsuite/ld-mips-elf/tlsdyn-o32-3.d
ld/testsuite/ld-mips-elf/tlsdyn-o32-3.got