Note that we don't even warn if scripts adjust a symbol as in
ld-elf/var1 and ld-scripts/pr14962.
include/
* bfdlink.h (struct bfd_link_info): Add warn_multiple_definition.
ld/
* ldexp.c (exp_fold_tree_1): Warn on script defining a symbol
defined in an object file.
* ldmain.c (multiple_definition): Heed info->warn_multiple_definition.
* testsuite/ld-scripts/defined5.d: Expect a warning.
This is embarrassing.
The whole point of CTF is that it remains intact even after a binary is
stripped, providing a compact mapping from symbols to types for
everything in the externally-visible interface of an ELF object: it has
connections to the symbol table for that purpose, and to the string
table to avoid duplicating symbol names. So it's a shame that the hooks
I implemented last year served to hook it up to the .symtab and .strtab,
which obviously disappear on strip, leaving any accompanying the CTF
dict containing references to strings (and, soon, symbols) which don't
exist any more because their containing strtab has been vaporized. The
original Solaris design used .dynsym and .dynstr (well, actually,
.ldynsym, which has more symbols) which do not disappear. So should we.
Thankfully the work we did before serves as guide rails, and adjusting
things to use the .dynstr and .dynsym was fast and easy. The only
annoyance is that the dynsym is assembled inside elflink.c in a fairly
piecemeal fashion, so that the easiest way to get the symbols out was to
hook in before every call to swap_symbol_out (we also leave in a hook in
front of symbol additions to the .symtab because it seems plausible that
we might want to hook them in future too: for now that hook is unused).
We adjust things so that rather than being offered a whole hash table of
symbols at once, libctf is now given symbols one at a time, with st_name
indexes already resolved and pointing at their final .dynstr offsets:
it's now up to libctf to resolve these to names as needed using the
strtab info we pass it separately.
Some bits might be contentious. The ctf_new_dynstr callback takes an
elf_internal_sym, and this remains an elf_internal_sym right down
through the generic emulation layers into ldelfgen. This is no worse
than the elf_sym_strtab we used to pass down, but in the future when we
gain non-ELF CTF symtab support we might want to lower the
elf_internal_sym to some other representation (perhaps a
ctf_link_symbol) in bfd or in ldlang_ctf_new_dynsym. We rename the
'apply_strsym' hooks to 'acquire_strings' instead, becuse they no longer
have anything to do with symbols.
There are some API changes to pieces of API which are technically public
but actually totally unused by anything and/or unused by anything but ld
so they can change freely: the ctf_link_symbol gains new fields to allow
symbol names to be given as strtab offsets as well as strings, and a
symidx so that the symbol index can be passed in. ctf_link_shuffle_syms
loses its callback parameter: the idea now is that linkers call the new
ctf_link_add_linker_symbol for every symbol in .dynsym, feed in all the
strtab entries with ctf_link_add_strtab, and then a call to
ctf_link_shuffle_syms will apply both and arrange to use them to reorder
the CTF symtab at CTF serialization time (which is coming in the next
commit).
Inside libctf we have a new preamble flag CTF_F_DYNSTR which is always
set in v3-format CTF dicts from this commit forwards: CTF dicts without
this flag are associated with .strtab like they used to be, so that old
dicts' external strings don't turn to garbage when loaded by new libctf.
Dicts with this flag are associated with .dynstr and .dynsym instead.
(The flag is not the next in sequence because this commit was written
quite late: the missing flags will be filled in by the next commit.)
Tests forthcoming in a later commit in this series.
bfd/ChangeLog
2020-11-20 Nick Alcock <nick.alcock@oracle.com>
* elflink.c (elf_finalize_dynstr): Call examine_strtab after
dynstr finalization.
(elf_link_swap_symbols_out): Don't call it here. Call
ctf_new_symbol before swap_symbol_out.
(elf_link_output_extsym): Call ctf_new_dynsym before
swap_symbol_out.
(bfd_elf_final_link): Likewise.
* elf.c (swap_out_syms): Pass in bfd_link_info. Call
ctf_new_symbol before swap_symbol_out.
(_bfd_elf_compute_section_file_positions): Adjust.
binutils/ChangeLog
2020-11-20 Nick Alcock <nick.alcock@oracle.com>
* readelf.c (dump_section_as_ctf): Use .dynsym and .dynstr, not
.symtab and .strtab.
include/ChangeLog
2020-11-20 Nick Alcock <nick.alcock@oracle.com>
* bfdlink.h (struct elf_sym_strtab): Replace with...
(struct elf_internal_sym): ... this.
(struct bfd_link_callbacks) <examine_strtab>: Take only a
symstrtab argument.
<ctf_new_symbol>: New.
<ctf_new_dynsym>: Likewise.
* ctf-api.h (struct ctf_link_sym) <st_symidx>: New.
<st_nameidx>: Likewise.
<st_nameidx_set>: Likewise.
(ctf_link_iter_symbol_f): Removed.
(ctf_link_shuffle_syms): Remove most parameters, just takes a
ctf_dict_t now.
(ctf_link_add_linker_symbol): New, split from
ctf_link_shuffle_syms.
* ctf.h (CTF_F_DYNSTR): New.
(CTF_F_MAX): Adjust.
ld/ChangeLog
2020-11-20 Nick Alcock <nick.alcock@oracle.com>
* ldelfgen.c (struct ctf_strsym_iter_cb_arg): Rename to...
(struct ctf_strtab_iter_cb_arg): ... this, changing fields:
<syms>: Remove.
<symcount>: Remove.
<symstrtab>: Rename to...
<strtab>: ... this.
(ldelf_ctf_strtab_iter_cb): Adjust.
(ldelf_ctf_symbols_iter_cb): Remove.
(ldelf_new_dynsym_for_ctf): New, tell libctf about a single
symbol.
(ldelf_examine_strtab_for_ctf): Rename to...
(ldelf_acquire_strings_for_ctf): ... this, only doing the strtab
portion and not symbols.
* ldelfgen.h: Adjust declarations accordingly.
* ldemul.c (ldemul_examine_strtab_for_ctf): Rename to...
(ldemul_acquire_strings_for_ctf): ... this.
(ldemul_new_dynsym_for_ctf): New.
* ldemul.h: Adjust declarations accordingly.
* ldlang.c (ldlang_ctf_apply_strsym): Rename to...
(ldlang_ctf_acquire_strings): ... this.
(ldlang_ctf_new_dynsym): New.
(lang_write_ctf): Call ldemul_new_dynsym_for_ctf with NULL to do
the actual symbol shuffle.
* ldlang.h (struct elf_strtab_hash): Adjust accordingly.
* ldmain.c (bfd_link_callbacks): Wire up new/renamed callbacks.
libctf/ChangeLog
2020-11-20 Nick Alcock <nick.alcock@oracle.com>
* ctf-link.c (ctf_link_shuffle_syms): Adjust.
(ctf_link_add_linker_symbol): New, unimplemented stub.
* libctf.ver: Add it.
* ctf-create.c (ctf_serialize): Set CTF_F_DYNSTR on newly-serialized
dicts.
* ctf-open-bfd.c (ctf_bfdopen_ctfsect): Check for the flag: open the
symtab/strtab if not present, dynsym/dynstr otherwise.
* ctf-archive.c (ctf_arc_bufpreamble): New, get the preamble from
some arbitrary member of a CTF archive.
* ctf-impl.h (ctf_arc_bufpreamble): Declare it.
PR 26626
* ldmain.c (undefined_symbol): Use the keyword undefined-symbol
when invoking the error handling script for undefined symbols.
* ld.texi: Update documentation.
PR 26626
* ldmain.c (undefined_symbol): If an error handlign script is
available, call it.
* ldfile.c (error_handling_script): Declare.
(ldfile_open_file): If a library cannot be found and an error
handling script is available, call it.
* ldmain.h (error_handling_script): Prototype.
* ldlex.h (OPTION_ERROR_HANDLING_SCRIPT): Define.
* lexsup.c (ld_options): Add --error-handling-script.
(parse_args): Add support for --errror-handling-script.
* ld.texi: Document the new feature.
* configure.ac: Add --error-handling-script option to disable
support for the new feature.
* NEWS: Mention the new feature.
* config.in: Regenerate.
* configure: Regenerate.
If an archive map contains symbols that aren't actually defined by the
indexed element for any reason, then loading that element will leave
the symbol undefined (or common). This leads to the possibility of
the element being loaded again should the archive be searched again
due to the action of --start-group/--end-group. The testcase
triggering this problem was an archive containing fat lto objects,
with the archive map incorrectly created by ar rather than gcc-ar.
PR 26150
* ldlang.c (ldlang_add_file): Assert that we aren't adding the
current end of link.next list again too.
* ldmain.c (add_archive_element): Don't load archive elements
again that have already been loaded.
Add a configure option, --enable-textrel-check=[no|yes|warning|error],
to decide what ELF linker should do by default with DT_TEXTREL in an
executable or shared library.
PR ld/20824
* NEWS: Mention --enable-textrel-check=[no|yes|warning|error].
* configure.ac: Add --enable-textrel-check=[no|yes|warning|error].
(DEFAULT_LD_TEXTREL_CHECK): New AC_DEFINE_UNQUOTED.
(DEFAULT_LD_TEXTREL_CHECK_WARNING): Likewise.
* ldmain.c (main): Initialize link_info.textrel_check to
DEFAULT_LD_TEXTREL_CHECK.
* lexsup.c (ld_options): Check DEFAULT_LD_TEXTREL_CHECK_WARNING.
* config.in: Regenerated.
* configure: Likewise.
This is quite complicated because the CTF section's contents depend on
the final contents of the symtab and strtab, because it has two sections
whose contents are shuffled to be in 1:1 correspondence with the symtab,
and an internal strtab that gets deduplicated against the ELF strtab
(with offsets adjusted to point into the ELF strtab instead). It is
also compressed if large enough, so its size depends on its contents!
So we cannot construct it as early as most sections: we cannot even
*begin* construction until after the symtab and strtab are finalized.
Thankfully there is already one section treated similarly: compressed
debugging sections: the only differences are that compressed debugging
sections have extra handling to deal with their changing name if
compressed (CTF sections are always called ".ctf" for now, though we
have reserved ".ctf.*" against future use), and that compressed
debugging sections have previously-uncompressed content which has to be
stashed away for later compression, while CTF sections have no content
at all until we generate it (very late).
BFD also cannot do the link itself: libctf knows how to do it, and BFD
cannot call libctf directly because libctf already depends on bfd for
file I/O. So we have to use a pair of callbacks, one, examine_strtab,
which allows a caller to examine the symtab and strtab after
finalization (called from elf_link_swap_symbols_out(), right before the
symtabs are written, and after the strtab has been finalized), and one
which actually does the emission (called emit_ctf simply because it is
grouped with a bunch of section-specific late-emission function calls at
the bottom of bfd_elf_final_link, and a section-specific name seems best
for that). emit_ctf is actually called *twice*: once from lang_process
if the emulation suggests that this bfd target does not examine the
symtab or strtab, and once via a bfd callback if it does. (This means
that non-ELF targets still get CTF emitted, even though the late CTF
emission stage is never called for them).
v2: merged with non-ELF support patch: slight commit message
adjustments.
v3: do not spend time merging CTF, or crash, if the CTF section is
explicitly discarded. Do not try to merge or compress CTF unless
linking.
v4: add CTF_COMPRESSION_THRESHOLD. Annul the freed input ctf_file_t's
after writeout: set SEC_IN_MEMORY on the output contents so a future
bfd enhancement knows it could free it. Add SEC_LINKER_CREATED |
SEC_KEEP to avoid having to add .ctf to the linker script. Drop
now-unnecessary ldlang.h-level elf-bfd.h include and hackery around
it. Adapt to elf32.em->elf.em and elf-generic.em->ldelf*.c
changes.
v5: fix tabdamage. Drop #inclusions in .h files: include in .c files,
.em files, and use struct forwards instead. Use bfd_section_is_ctf
inline function rather than SECTION_IS_CTF macro. Move a few
comments.
* Makefile.def (dependencies): all-ld depends on all-libctf.
* Makefile.in: Regenerated.
include/
* bfdlink.h (elf_strtab_hash): New forward.
(elf_sym_strtab): Likewise.
(struct bfd_link_callbacks <examine_strtab>): New.
(struct bfd_link_callbacks <emit_ctf>): Likewise.
bfd/
* elf-bfd.h (bfd_section_is_ctf): New inline function.
* elf.c (special_sections_c): Add ".ctf".
(assign_file_positions_for_non_load_sections): Note that
compressed debugging sections etc are not assigned here. Treat
CTF sections like SEC_ELF_COMPRESS sections when is_linker_output:
sh_offset -1.
(assign_file_positions_except_relocs): Likewise.
(find_section_in_list): Note that debugging and CTF sections, as
well as reloc sections, are assigned later.
(_bfd_elf_assign_file_positions_for_non_load): CTF sections get
their size and contents updated.
(_bfd_elf_set_section_contents): Skip CTF sections: unlike
compressed sections, they have no uncompressed content to copy at
this stage.
* elflink.c (elf_link_swap_symbols_out): Call the examine_strtab
callback right before the strtab is written out.
(bfd_elf_final_link): Don't cache the section contents of CTF
sections: they are not populated yet. Call the emit_ctf callback
right at the end, after all the symbols and strings are flushed
out.
ld/
* ldlang.h: (struct lang_input_statement_struct): Add the_ctf.
(struct elf_sym_strtab): Add forward.
(struct elf_strtab_hash): Likewise.
(ldlang_ctf_apply_strsym): Declare.
(ldlang_write_ctf_late): Likewise.
* ldemul.h (ldemul_emit_ctf_early): New.
(ldemul_examine_strtab_for_ctf): Likewise.
(ld_emulation_xfer_type) <emit_ctf_early>: Likewise.
(ld_emulation_xfer_type) <examine_strtab_for_ctf>: Likewise.
* ldemul.c (ldemul_emit_ctf_early): New.
(ldemul_examine_strtab_for_ctf): Likewise.
* ldlang.c: Include ctf-api.h.
(CTF_COMPRESSION_THRESHOLD): New.
(ctf_output): New. Initialized in...
(ldlang_open_ctf): ... this new function. Open all the CTF
sections in the input files: mark them non-loaded and empty
so as not to copy their contents to the output, but linker-created
so the section gets created in the target.
(ldlang_merge_ctf): New, merge types via ctf_link_add_ctf and
ctf_link.
(ldlang_ctf_apply_strsym): New, an examine_strtab callback: wrap
ldemul_examine_strtab_for_ctf.
(lang_write_ctf): New, write out the CTF section.
(ldlang_write_ctf_late): New, late call via bfd's emit_ctf hook.
(lang_process): Call ldlang_open_ctf, ldlang_merge_ctf, and
lang_write_ctf.
* ldmain.c (link_callbacks): Add ldlang_ctf_apply_strsym,
ldlang_write_ctf_late.
* emultempl/aix.em: Add ctf-api.h.
* emultempl/armcoff.em: Likewise.
* emultempl/beos.em: Likewise.
* emultempl/elf.em: Likewise.
* emultempl/generic.em: Likewise.
* emultempl/linux.em: Likewise.
* emultempl/msp430.em: Likewise.
* emultempl/pe.em: Likewise.
* emultempl/pep.em: Likewise.
* emultempl/ticoff.em: Likewise.
* emultempl/vanilla.em: Likewise.
* ldcref.c: Likewise.
* ldctor.c: Likewise.
* ldelf.c: Likewise.
* ldelfgen.c: Likewise.
* ldemul.c: Likewise.
* ldexp.c: Likewise.
* ldfile.c: Likewise.
* ldgram.c: Likewise.
* ldlex.l: Likewise.
* ldmain.c: Likewise.
* ldmisc.c: Likewise.
* ldver.c: Likewise.
* ldwrite.c: Likewise.
* lexsup.c: Likewise.
* mri.c: Likewise.
* pe-dll.c: Likewise.
* plugin.c: Likewise.
* ldelfgen.c (ldelf_emit_ctf_early): New.
(ldelf_examine_strtab_for_ctf): tell libctf about the symtab and
strtab.
(struct ctf_strsym_iter_cb_arg): New, state to do so.
(ldelf_ctf_strtab_iter_cb): New: tell libctf about
each string in the strtab in turn.
(ldelf_ctf_symbols_iter_cb): New, tell libctf
about each symbol in the symtab in turn.
* ldelfgen.h (struct elf_sym_strtab): Add forward.
(struct elf_strtab_hash): Likewise.
(struct ctf_file): Likewise.
(ldelf_emit_ctf_early): Declare.
(ldelf_examine_strtab_for_ctf): Likewise.
* emultempl/elf-generic.em (LDEMUL_EMIT_CTF_EARLY): Set it.
(LDEMUL_EXAMINE_STRTAB_FOR_CTF): Likewise.
* emultempl/aix.em (ld_${EMULATION_NAME}_emulation): Add
emit_ctf_early and examine_strtab_for_ctf, NULL by default.
* emultempl/armcoff.em (ld_${EMULATION_NAME}_emulation): Likewise.
* emultempl/beos.em (ld_${EMULATION_NAME}_emulation): Likewise.
* emultempl/elf.em (ld_${EMULATION_NAME}_emulation): Likewise.
* emultempl/generic.em (ld_${EMULATION_NAME}_emulation): Likewise.
* emultempl/linux.em (ld_${EMULATION_NAME}_emulation): Likewise.
* emultempl/msp430.em (ld_${EMULATION_NAME}_emulation): Likewise.
* emultempl/pe.em (ld_${EMULATION_NAME}_emulation): Likewise.
* emultempl/pep.em (ld_${EMULATION_NAME}_emulation): Likewise.
* emultempl/ticoff.em (ld_${EMULATION_NAME}_emulation): Likewise.
* emultempl/vanilla.em (ld_vanilla_emulation): Likewise.
* Makefile.am: Pull in libctf (and zlib, a transitive requirement
for compressed CTF section emission). Pass it on to DejaGNU.
* configure.ac: Add AM_ZLIB.
* aclocal.m4: Added zlib.m4.
* Makefile.in: Regenerated.
* testsuite/ld-bootstrap/bootstrap.exp: Use it when relinking ld.
"next" and "next_real_file" in lang_input_statement_type always point
to another lang_input_statement_type, so it makes sense for these to
not be the generic lang_statement_union_type. This patch also updates
a number of variables in ldlang.c for the same reason, and modifies
lang_statement_append to reduce the need for casts.
* ldlang.h (lang_input_statement_type): Make next
and next_real_file a lang_input_statement_type pointer.
(lang_statement_append): Delete prototype.
(LANG_FOR_EACH_INPUT_STATEMENT): Update for lang_input_statement_type
change.
* ldmain.c (add_archive_element): Likewise.
* ldlang.c: Likewise throughout.
(lang_statement_append): Make static. Make element and field
void pointers. Remove casts in calls.
(lang_check): Use a lang_input_statement_type pointer for "file".
(find_rescan_insertion): Similarly for "iter" and return value.
(lang_process): Similarly for "insert", "iter" and "temp".
* emultempl/spuelf.em (embedded_spu_file): Likewise.
* emultempl/aix.em (gld${EMULATION_NAME}_before_allocation): Expand
lang_statment_append call.
PR 24576
* ld/ldfile.c: (ldfile_open_command_file_1): Add new parameter -
is_script. If true check that the file has not already been
parsed as a linker script.
(ldfile_open_script_file): New function.
(ldfile_try_open_bfd): Use the new function in place of
ldfile_open_command_line.
* ldmain.c (main): Likewise.
* lexsup.c (parse_args): Use the new function for opening linker
scripts with the -T option.
* ldfile.h (ldfile_open_script_file): Add prototype.
Add a new option to disable the listing of discarded sections
in map file output. The use case stems from a large application
built with -ffunction-sections --gc-sections where the list of
discarded sections blows up the map file output. The default
behaviour remains to print discarded sections, but the new option
allows us to disable it.
ld/
* NEWS: Mention new option --no-print-map-discarded.
* ld.h (ld_config_type) <print_map_discarded>: New field.
* ldlang.c (lang_map): Conditionally output discarded sections
in map files based on configuration option.
* ldlex.h (option_values) <OPTION_PRINT_MAP_DISCARDED,
OPTION_NO_PRINT_MAP_DISCARDED>: New.
* ldmain.c (main): Enabled print_map_discarded by default.
* lexsup.c (ld_options): Add new command-line options.
(parse_args) <OPTION_NO_PRINT_MAP_DISCARDED,
OPTION_PRINT_MAP_DISCARDED>: New cases.
* ld.texi: Document new options.
* testsuite/ld-gc/gc.exp: Add new test.
* testsuite/ld-gc/skip-map-discarded.s: New file.
* testsuite/ld-gc/skip-map-discarded.d: New file.
* testsuite/ld-gc/skip-map-discarded.map: New file.
Similarly to commit 174d0a74a2 ("PowerPC/BFD: Convert `%P: %H:' to
`%H:' in error messages") convert linker relocation error messages to
use `%H:' rather `%P: %H:', removing inconsistent message composition
like:
$ cat reloc-j.s
.text
.globl foo
.ent foo
foo:
j bar
j bar
.end foo
$ cat reloc-j.ld
SECTIONS
{
bar = 0x12345678;
.text : { *(.text) }
/DISCARD/ : { *(*) }
}
$ as -o reloc-j.o reloc-j.s
$ ld -T reloc-j.ld -o reloc-j reloc-j.o
ld: tmpdir/reloc-j.o: in function `foo':
(.text+0x0): relocation truncated to fit: R_MIPS_26 against `bar'
ld: (.text+0x8): relocation truncated to fit: R_MIPS_26 against `bar'
$
where subsequent lines referring to issues within a single function have
the name of the linker executable prepended, but the first one does not.
As noted with the commit referred this breaks a GNU Coding Standard's
requirement that error messages from compilers should look like this:
source-file-name:lineno: message
also quoted in `vfinfo' code handling these specifiers.
Remove the linker name prefix then, making the messages now look like:
$ ld -T reloc-j.ld -o reloc-j reloc-j.o
tmpdir/reloc-j.o: in function `foo':
(.text+0x0): relocation truncated to fit: R_MIPS_26 against `bar'
(.text+0x8): relocation truncated to fit: R_MIPS_26 against `bar'
$
instead.
ld/
* ldmain.c (reloc_overflow): Use `%H:' rather than `%P: %H:'
with `einfo'.
(reloc_dangerous): Likewise.
(unattached_reloc): Likewise.
The idea of this change is to make -t output useful for users wanting
to package all the object files involved in linking for a bug report.
Something like the following should do the trick.
gcc hello.c -save-temps -Wl,-t | xargs realpath | sort | uniq > files
tar cJf test.tar.xz `cat files`
* ldlang.c (load_symbols): When -t, print file names for script
files and archives.
* ldmain.c (trace_files): Make an int.
(add_archive_element): Print archive elements only with multiple
-t options, or when archive is thin.
* ldmain.h (trace_files): Update.
* ldmisc.c (vfinfo): Don't print both original path and path in
sysroot.
* lexsup.c (parse_args <t>): Increment trace_files.
This output really belongs in ld --verbose.
* ldmain.c (main): Print emulation mode and "deleting executable"
for --verbose, not --trace.
(add_archive_element): Only print "no new IR symbols" for --verbose.
Prepending '/' to absolute paths doesn't gain us much, and results in
the current implementation of --trace emitting silly path-in-sysroot
output, eg.
/lib/ld-linux-x86-64.so.2 (//lib/ld-linux-x86-64.so.2)
* ldmain.c (get_sysroot): Return "" for "--sysroot=/".
This patch performs a run-time test that a shared libbfd.so has been
compiled with the same size bfd_vma as that of apps using the library.
On a 32-bit host it is easily possible to have one libbfd.so compiled
to support 64-bit targets (or configured with --enable-64-bit-bfd)
while another only supports 32-bit targets. The two libraries will
have differently sized bfd_vma types, and if the wrong one is loaded
all sorts of weird behaviour might be seen.
bfd/
PR 23534
* init.c (BFD_INIT_MAGIC): Define.
(bfd_init): Return BFD_INIT_MAGIC.
bfd-in2.h: Regenerate.
binutils/
PR 23534
* addr2line.c (main): Exit with fatal error if bfd_init
returns an unexpected value.
* ar.c (main): Likewise.
* dlltool.c (identify_dll_for_implib): Likewise.
* nm.c (main): Likewise.
* objcopy.c (main): Likewise.
* objdump.c (main): Likewise.
* size.c (main): Likewise.
* strings.c (main): Likewise.
* windmc.c (main): Likewise.
* windres.c (main): Likewise.
gas/
PR 23534
* as.c (main): Exit with fatal error if bfd_init returns an
unexpected value.
ld/
PR 23534
* ldmain.c (main): Exit with fatal error if bfd_init returns
an unexpected value.
Andrew Sadek <andrew.sadek.se@gmail.com>
A new implemented feature in GCC Microblaze that allows Position
Independent Code to run using Data Text Relative addressing instead
of using Global Offset Table.
Its aim was to make 'PIC' more efficient and flexible as elf size
excess performance overhead were noticed when using GOT due to the
indirect addressing.
include/ChangeLog:
* bfdlink.h (Add flag): Add new flag @ 'bfd_link_info' struct.
* elf/microblaze.h (Add 3 new relocations):
R_MICROBLAZE_TEXTPCREL_64, R_MICROBLAZE_TEXTREL_64
and R_MICROBLAZE_TEXTREL_32_LO for relax function.
bfd/ChangeLog:
* bfd/reloc.c (2 new BFD relocations):
BFD_RELOC_MICROBLAZE_64_TEXTPCREL &
BFD_RELOC_MICROBLAZE_64_TEXTPCREL
* bfd/bfd-in2.h: Regenerate
* bfd/libbfd.h: Regenerate
* bfd/elf32-microblaze.c (Handle new relocs): define 'HOWTO' of 3
new relocs and handle them in both relocate and relax functions.
(microblaze_elf_reloc_type_lookup): add mapping between for new
bfd relocs.
(microblaze_elf_relocate_section): Handle new relocs in case of
elf relocation.
(microblaze_elf_relax_section): Handle new relocs for elf relaxation.
gas/ChangeLog:
* gas/config/tc-microblaze.c (Handle new relocs directives in
assembler): Handle new relocs from compiler output.
(imm_types): add new imm types for data text relative addressing
TEXT_OFFSET, TEXT_PC_OFFSET
(md_convert_frag): conversion for BFD_RELOC_MICROBLAZE_64_TEXTPCREL,
BFD_RELOC_MICROBLAZE_64_TEXTPCREL
(md_apply_fix): apply fix for BFD_RELOC_MICROBLAZE_64_TEXTPCREL,
BFD_RELOC_MICROBLAZE_64_TEXTPCREL
(md_estimate_size_before_relax): estimate size for
BFD_RELOC_MICROBLAZE_64_TEXTPCREL,
BFD_RELOC_MICROBLAZE_64_TEXTPCREL
(tc_gen_reloc): generate relocations for
BFD_RELOC_MICROBLAZE_64_TEXTPCREL,
BFD_RELOC_MICROBLAZE_64_TEXTPCREL
ld/ChangeLog:
* ld/lexsup.c (Add 2 ld options):
(ld_options): add disable-multiple-abs-defs @ 'ld_options' array
(parse_args): parse new option and pass flag to 'link_info' struct.
* ld/ldlex.h (Add enum): add new enum @ 'option_values' enum.
* ld/ld.texinfo (Add new option): Add description for
'disable-multiple-abs-defs'
* ld/main.c: Initialize flags with false @ 'main'. Handle
disable-multiple-abs-defs @ 'mutiple_definition'.
max-page-size only matters for demand paged executables or shared
libraries, and the ideal size is the largest value used by your
operating system. Values larger than necessary just waste file space
and memory. common-page-size also affects file and memory size,
trading a possible small increase in file size for a decrease in
memory size when the operating system is using a common-page-size
page. With a powerpc max-page-size of 64k and common-page-size of 4k
many executables will use no more memory pages when the system page
size is 4k than an executable linked with -z max-page-size=0x1000,
yet will still run on a system using 64k pages. However, when running
on a system using 64k pages relro protection will not be completely
effective.
Due to the relro problem, powerpc binutils has been using a default
common-page-size of 64k since 2014-12-18 (git commit 04c6a44c7),
leading to complaints about increased file and memory sizes. People
not using relro do have a valid reason to complain..
So this patch introduces an extra back-end value to use as the default
for common-page-size when generating relro executables, and enables
the support for powerpc. Non relro executables will now be generated
with a default common-page-size of 4k.
bfd/
* elf-bfd.h (struct elf_backend_data): Add relropagesize.
* elfxx-target.h (ELF_RELROPAGESIZE): Provide default and
sanity test.
(elfNN_bed): Init relropagesize.
* bfd.c (bfd_emul_get_commonpagesize): Add boolean param to
select relropagesize.
* elf32-ppc.c (ELF_COMMONPAGESIZE): Define as 0x1000.
(ELF_RELROPAGESIZE): Define as ELF_MAXPAGESIZE.
(ELF_MINPAGESIZE): Don't define.
* elf64-ppc.c (ELF_COMMONPAGESIZE): Define as 0x1000.
(ELF_RELROPAGESIZE): Define as ELF_MAXPAGESIZE.
* bfd-in2.h: Regenerate.
ld/
* ldmain.c (main): Move config.maxpagesize and
config.commonpagesize initialization to..
* ldemul.c (after_parse_default): ..here.
* testsuite/ld-powerpc/ppc476-shared.d: Pass -z common-page-size.
* testsuite/ld-powerpc/ppc476-shared2.d: Likewise.
The problem was the ld expect libiberty/lrealpath() to always return a
path, but in some cases it returns a prefix. It seemed like too much of
an earthquake to propose a fix to lrealpath.
* ldmain.c (main): Remove directory separator, if any, from the
end of the canonicalized sysroot.
ld ought to be more clever about where it puts LTO recompiled objects.
Ideally the recompiled objects ought to be ordered to the same place
their IR objects were, and files extracted from archives on the second
pass ought to go in the same place as they would if extracted on the
first pass. This patch addresses the archive problem. Without this
fix, objects extracted from archives might be placed after the crt
files intended to go at the end of an executable or shared library,
possibly causing exception handling failures.
* ldlang.h (lang_input_statement_type): Expand comments.
(LANG_FOR_EACH_INPUT_STATEMENT): Rewrite without casts.
* ldlang.c (lang_for_each_input_file): Likewise.
(load_symbols): Set usrdata for archives.
(find_rescan_insertion): New function.
(lang_process): Trim off and reinsert entries added to file chain
when rescanning archives for LTO.
* ldmain.c (add_archive_element): Set my_archive input_statement
next pointer to last element added.
When --no-define-common is used to build shared library, treat common
symbol as undefined so that common symbols that are referenced from a
shared library to be assigned addresses only in the main program. This
eliminates the unused duplicate space in the shared library, and also
prevents any possible confusion over resolving to the wrong duplicate
when there are many dynamic modules with specialized search paths for
runtime symbol resolution.
--no-define-common is only allowed when building a shared library.
bfd/
PR ld/21903:
* elflink.c (elf_link_add_object_symbols): Treat common symbol
as undefined for --no-define-common.
include/
PR ld/21903:
* bfdlink.h (bfd_link_info): Add inhibit_common_definition.
ld/
PR ld/21903:
* ld.h (command_line): Remove inhibit_common_definition.
* ldgram.y: Replace command_line.inhibit_common_definition with
link_info.inhibit_common_definition.
* ldlang.c (lang_common): Likewise.
* lexsup.c (parse_args): Likewise.
* ldmain.c (main): Only allow --no-define-common with -shared.
* testsuite/ld-elf/pr21903.s: New file.
* testsuite/ld-elf/pr21903a.d: Likewise.
* testsuite/ld-elf/pr21903b.d: Likewise.
* testsuite/ld-elf/pr21903c.d: Likewise.
* testsuite/ld-elf/pr21903d.d: Likewise.
* testsuite/ld-elf/pr21903e.d: Likewise.
This commit adds a new linker feature: the ability to resolve section
groups as part of a relocatable link.
Currently section groups are automatically resolved when performing a
final link, and are carried through when performing a relocatable link.
By carried through this means that one copy of each section group (from
all the copies that might be found in all the input files) is placed
into the output file. Sections that are part of a section group will
not match input section specifiers within a linker script and are
forcibly kept as separate sections.
There is a slight resemblance between section groups and common
section. Like section groups, common sections are carried through when
performing a relocatable link, and resolved (allocated actual space)
only at final link time.
However, with common sections there is an ability to force the linker to
allocate space for the common sections when performing a relocatable
link, there's currently no such ability for section groups.
This commit adds such a mechanism. This new facility can be accessed in
two ways, first there's a command line switch --force-group-allocation,
second, there's a new linker script command FORCE_GROUP_ALLOCATION. If
one of these is used when performing a relocatable link then the linker
will resolve the section groups as though it were performing a final
link, the section group will be deleted, and the members of the group
will be placed like normal input sections. If there are multiple copies
of the group (from multiple input files) then only one copy of the group
members will be placed, the duplicate copies will be discarded.
Unlike common sections that have the --no-define-common command line
flag, and INHIBIT_COMMON_ALLOCATION linker script command there is no
way to prevent group resolution during a final link, this is because the
ELF gABI specifically prohibits the presence of SHT_GROUP sections in a
fully linked executable. However, the code as written should make
adding such a feature trivial, setting the new resolve_section_groups
flag to false during a final link should work as you'd expect.
bfd/ChangeLog:
* elf.c (_bfd_elf_make_section_from_shdr): Don't initially mark
SEC_GROUP sections as SEC_EXCLUDE.
(bfd_elf_set_group_contents): Replace use of abort with an assert.
(assign_section_numbers): Use resolve_section_groups flag instead
of relocatable link type.
(_bfd_elf_init_private_section_data): Use resolve_section_groups
flag instead of checking the final_link flag for part of the
checks in here. Fix white space as a result.
* elflink.c (elf_link_input_bfd): Use resolve_section_groups flag
instead of relocatable link type.
(bfd_elf_final_link): Likewise.
include/ChangeLog:
* bfdlink.h (struct bfd_link_info): Add new resolve_section_groups
flag.
ld/ChangeLog:
* ld.h (struct args_type): Add force_group_allocation field.
* ldgram.y: Add support for FORCE_GROUP_ALLOCATION.
* ldlex.h: Likewise.
* ldlex.l: Likewise.
* lexsup.c: Likewise.
* ldlang.c (unique_section_p): Check resolve_section_groups flag
not the relaxable link flag.
(lang_add_section): Discard section groups when we're resolving
groups. Clear the SEC_LINK_ONCE flag if we're resolving section
groups.
* ldmain.c (main): Initialise resolve_section_groups flag in
link_info based on command line flags.
* testsuite/ld-elf/group11.d: New file.
* testsuite/ld-elf/group12.d: New file.
* testsuite/ld-elf/group12.ld: New file.
* NEWS: Mention new features.
* ld.texinfo (Options): Document --force-group-allocation.
(Miscellaneous Commands): Document FORCE_GROUP_ALLOCATION.
This option switches on ld.bfd --enable-new-dtags by default.
* configure.ac: Add --enable-new-dtags option.
* ldmain.c: Set link_info.new_dtags to 1 if when --enable-new-dtags is
switched on.
* configure: Regenerate.
* config.in: Regenerate.
2016-10-31 Thomas Preud'homme <thomas.preudhomme@arm.com>
ld/
* ldmain.c (add_archive_element): Initialize input->header.type.
* plugin.c (plugin_maybe_claim): Assert the statement is an input
statement.
* ldmain.c (default_bfd_error_handler): New function pointer.
(ld_bfd_error_handler): New function.
(main): Arrange to call it on bfd errors/warnings.
(ld_bfd_assert_handler): Enable tail call.
Many more places use abfd->my_archive rather than bfd_my_archive (abfd),
so let's make the code consistently use the first idiom.
bfd/
* bfd-in.h (bfd_my_archive): Delete.
* bfd-in2.h: Regenerate.
binutils/
* ar.c: Expand uses of bfd_my_archive.
* size.c: Likewise.
ld/
* ldlang.c: Expand uses of bfd_my_archive.
* ldmain.c: Likewise.
* ldmisc.c: Likewise.
* plugin.c: Likewise.
