* ld.h (parsing_defsym): Delete.
* ldexp.c (exp_intop, exp_bigintop, exp_relop): Set type.filename.
(fold_binary, fold_name, exp_fold_tree_1, exp_get_vma, exp_get_fill,
exp_get_abs_int): Add tree arg for %S in error messages. Don't
fudge lineno.
(exp_binop, exp_unop, exp_nameop, exp_assop, exp_assert): Copy
type.filename from sub-tree.
(exp_trinop): Likewise, and use "cond" rather than "lhs".
* ldexp.h (node_type): Add filename field to struct.
* ldfile.c (ldfile_input_filename): Delete. Remove all refs.
* ldfile.h (ldfile_input_filename): Delete.
* ldgram.y (phdr_type, phdr_qualifiers, yyerror): Add NULL arg for
%S in error messages.
* ldemul.c (syslib_default, hll_default): Likewise.
* ldlang.c (lang_memory_region_lookup, lang_memory_region_alias,
lang_get_regions, lang_new_phdr): Likewise.
(lang_size_sections_1): Pass addr_tree for %S.
* ldlex.h (lex_redirect): Update prototype.
(ldlex_filename): Declare.
* ldlex.l (<EOF>): Don't set ldfile_input_filename.
(lex_redirect): Add fake_filename and count params. Push
fake_filename to file_name_stack and init lineno from count.
(ldlex_filename): New function.
(lex_warn_invalid): Use above.
* ldmain.c (main): Update lex_redirect call.
* ldmisc.c (vfinfo <%S>): Take file name and line number from
etree_type arg, or use current if arg is NULL.
* lexsup.c (parsing_defsym): Delete.
(parse_args <OPTION_DEFSYM>): Update lex_redirect call.
[PATCH] Add infrastructure for plugin API; functionality to follow.
include/ChangeLog:
2010-10-14 Dave Korn <dave.korn.cygwin@gmail.com>
Apply LD plugin patch series (part 1/6).
* plugin-api.h (LDPT_GNU_LD_VERSION): New ld_plugin_tag enum member.
ld/ChangeLog:
2010-10-14 Dave Korn <dave.korn.cygwin@gmail.com>
Apply LD plugin patch series (part 1/6).
* configure.in: Add AC_CHECKs for file io and dlfcn headers and
functions and AC_SEARCH for -ldl.
(enable_plugins): New shell variable set if above tests find dlopen
functionality.
(ENABLE_PLUGINS): Add related automake conditional.
* configure: Regenerate.
* config.in: Likewise.
* Makefile.am (PLUGIN_C): Declare plugin C source file, conditional
on ENABLE_PLUGINS being defined.
(PLUGIN_H): Likewise for header file.
(PLUGIN_OBJECT): Likewise for object file.
(PLUGIN_CFLAGS): Likewise -D flag required to compile plugin support.
(AM_CPPFLAGS): Use PLUGIN_CFLAGS.
(CFILES): Use PLUGIN_C.
(HFILES): Use PLUGIN_H.
(OFILES): Use PLUGIN_OBJECT.
(ld_new_SOURCES): Use PLUGIN_C.
(noinst_LTLIBRARIES)[ENABLE_PLUGINS]: Declare test plugin.
(libldtestplug_la_SOURCES)[ENABLE_PLUGINS]: Add automake definition
for test plugin.
(libldtestplug_la_CFLAGS)[ENABLE_PLUGINS]: Likewise.
(libldtestplug_la_LDFLAGS)[ENABLE_PLUGINS]: Likewise.
* Makefile.in: Regenerate.
* sysdep.h: Include stdarg.h, unistd.h and one of fcntl.h or
sys/file.h where available. Include dlfcn.h when ENABLE_PLUGINS.
(O_RDONLY): Supply default definition likewise to bfd's sysdep.h
(O_WRONLY): Likewise.
(O_RDWR): Likewise.
(O_ACCMODE): Likewise.
(O_BINARY): Likewise.
(SEEK_SET): Likewise.
(SEEK_CUR): Likewise.
(SEEK_END): Likewise.
* ldmisc.c (vfinfo): Make non-static. Add %p format char.
* ldmisc.h (vfinfo): Declare extern prototype.
* lexsup.c (enum option_values)[ENABLE_PLUGINS]: Add new entries for
OPTION_PLUGIN and OPTION_PLUGIN_OPT.
(ld_options[])[ENABLE_PLUGINS]: Add option data for the above two.
(parse_args)[ENABLE_PLUGINS]: Handle them, and load all plugins once
option parsing is complete.
* ldmain.c (main)[ENABLE_PLUGINS]: Call plugin cleanup hooks just
after lang_finish.
* plugin.c: New source file.
* plugin.h: Likewise new header.
* testplug.c: New source file.
ld/testsuite/ChangeLog:
2010-10-14 Dave Korn <dave.korn.cygwin@gmail.com>
Apply LD plugin patch series (part 1/6).
* ld-bootstrap/bootstrap.exp: Skip static tests also if LD plugins
are enabled.
* lib/ld-lib.exp (proc regexp_diff): Extend verbose debug output.
(proc set_file_contents): Write a file with the supplied content.
(run_ld_link_tests): Add new 'ld' action to test linker output.
(proc check_plugin_api_available): Return true if linker under test
supports the plugin API.
* ld-plugin/func.c: New test source file.
* ld-plugin/main.c: Likewise.
* ld-plugin/text.c: Likewise.
* ld-plugin/plugin-1.d: New dump test output pattern script.
* ld-plugin/plugin-2.d: Likewise.
* ld-plugin/plugin-3.d: Likewise.
* ld-plugin/plugin-4.d: Likewise.
* ld-plugin/plugin-5.d: Likewise.
* ld-plugin/plugin.exp: New test control script.
---
[PATCH] Implement claim file and all symbols read hooks and add symbols callback.
ld/ChangeLog:
2010-10-14 Dave Korn <dave.korn.cygwin@gmail.com>
Apply LD plugin patch series (part 2/6).
* ldfile.c (ldfile_try_open_bfd)[ENABLE_PLUGINS]: Don't return early
during compat checks if they pass, instead offer any successfully
opened and accepted file to the plugin claim file hooks chain. Create
a dummy bfd to accept symbols added by the plugin, if the plugin
claims the file.
* ldlang.c (lang_process)[ENABLE_PLUGINS]: Call plugin all symbols
read hook chain before ldemul_after_open.
* ldlang.h (struct lang_input_statement_struct): Add new single-bit
'claimed' flag.
* plugin.c (IRONLY_SUFFIX): New macro for dummy bfd file suffix.
(IRONLY_SUFFIX_LEN): Length of the above string.
(plugin_get_ir_dummy_bfd): New function to create the dummy bfd used
to store symbols for ir-only files.
(is_ir_dummy_bfd): New function to check if a bfd is ir-only.
(asymbol_from_plugin_symbol): New function converts symbol formats.
(add_symbols): Call it to convert plugin syms to bfd syms and add
them to the dummy bfd.
* plugin.h: Add missing include guards.
(plugin_get_ir_dummy_bfd): Add prototype.
(is_ir_dummy_bfd): Likewise.
* testplug.c (TV_MESSAGE): New helper macro.
(struct claim_file): New struct.
(claim_file_t): New typedef.
(tag_names[]): Make static and const.
(claimfiles_list): New variable.
(claimfiles_tail_chain_ptr): Likewise.
(last_claimfile): Likewise.
(record_claim_file): Record a file to claim on a singly-linked list.
(parse_symdefstr): Parse an ASCII representation of a symbol from a
plugin option into the fields of a struct ld_plugin_symbol.
(record_claimed_file_symbol): Use it to parse plugin option for
adding a symbol.
(parse_option): Parse claim file and add symbol options.
(dump_tv_tag): Use TV_MESSAGE.
(onload): Likewise.
(onclaim_file): Make static. Use TV_MESSAGE. Scan list of files to
claim and claim this file if required, adding any symbols specified.
(onall_symbols_read): Make static and use TV_MESSAGE.
(oncleanup): Likewise.
ld/testsuite/ChangeLog:
2010-10-14 Dave Korn <dave.korn.cygwin@gmail.com>
Apply LD plugin patch series (part 2/6).
* ld-plugin/plugin-3.d: Enable regexes for new functionality.
* ld-plugin/plugin-5.d: Likewise.
* ld-plugin/plugin-6.d: New testcase.
* ld-plugin/plugin-7.d: Likewise.
* ld-plugin/plugin.exp: Use 'nm' on compiled test objects to determine
whether symbols in plugin arguments need an underscore prefix. Add
new plugin-6.d and plugin-7.d testcases.
---
[PATCH] Implement get symbols callback.
ld/ChangeLog:
2010-10-14 Dave Korn <dave.korn.cygwin@gmail.com>
Apply LD plugin patch series (part 3/6).
* ldmain.c (notice)[ENABLE_PLUGINS]: Call plugin_notice.
* plugin.c (non_ironly_hash): Add new bfd hash table.
(plugin_load_plugins): Exit early if no plugins to load. If plugins
do load successfully, set notice_all flag in link info.
(get_symbols): Implement.
(plugin_load_plugins): Exit early if no plugins to load, else after
loading plugins successfully enable notice_all mode.
(init_non_ironly_hash): Lazily init non_ironly_hash table.
(plugin_notice): Record symbols referenced from non-IR files in the
non_ironly_hash. Suppress tracing, cref generation and nocrossrefs
tracking for symbols from dummy IR bfds.
* plugin.h: Fix formatting.
(plugin_notice): Add prototype.
* testplug.c (dumpresolutions): New global var.
(parse_options): Accept "dumpresolutions".
(onall_symbols_read): Get syms and dump resolutions if it was given.
ld/testsuite/ChangeLog:
2010-10-14 Dave Korn <dave.korn.cygwin@gmail.com>
Apply LD plugin patch series (part 3/6).
* ld-plugin/plugin-8.d: New testcase.
* ld-plugin/plugin.exp: Invoke it.
---
[PATCH] Implement add input file, add input lib and set extra lib path callbacks.
ld/ChangeLog:
2010-10-14 Dave Korn <dave.korn.cygwin@gmail.com>
Apply LD plugin patch series (part 4/6).
* ldlang.c (lang_process)[ENABLE_PLUGINS]: Move invocation of
plugin_call_all_symbols_read to before setting of gc_sym_list, and
open any new input files that may have been added during it.
* ldmain.c (multiple_definition)[ENABLE_PLUGINS]: Call out to
plugin_multiple_definition and let it have first say over what to do
with the clashing definitions.
* plugin.c (no_more_claiming): New boolean variable.
(plugin_cached_allow_multiple_defs): Likewise.
(add_input_file): Implement.
(add_input_library): Likewise.
(set_extra_library_path): Likewise.
(plugin_call_claim_file): Don't do anything when no_more_claiming set.
(plugin_call_all_symbols_read): Set it. Disable link info
"allow_multiple_definition" flag, but cache its value.
(plugin_multiple_definition): New function.
* plugin.h (plugin_multiple_definition): Add prototype.
* testplug.c (addfile_enum_t): New enumerated typedef.
(add_file_t): New struct typedef.
(addfiles_list): New variable.
(addfiles_tail_chain_ptr): Likewise.
(record_add_file): New function.
(parse_option): Parse "add:", "lib:" and "dir:" options and call it.
(onall_symbols_read): Iterate the list of new files, libs and dirs,
adding them.
ld/testsuite/ChangeLog:
2010-10-14 Dave Korn <dave.korn.cygwin@gmail.com>
Apply LD plugin patch series (part 4/6).
* ld-plugin/plugin-9.d: New testcase.
* ld-plugin/plugin.exp: Invoke it.
---
[PATCH] Add ELF symbol visibility support to plugin interface.
ld/ChangeLog:
2010-10-14 Dave Korn <dave.korn.cygwin@gmail.com>
Apply LD plugin patch series (part 5/6).
* plugin.c (asymbol_from_plugin_symbol): If the bfd is an ELF bfd,
find the elf symbol data and set the visibility in the st_other field.
ld/testsuite/ChangeLog:
2010-10-14 Dave Korn <dave.korn.cygwin@gmail.com>
Apply LD plugin patch series (part 5/6).
* ld-plugin/plugin-ignore.d: New dump test control script.
* ld-plugin/plugin-vis-1.d: Likewise.
* ld-plugin/plugin.exp: Add list of ELF-only tests and run them if
testing on an ELF target.
---
[PATCH] Add archive support to plugin interface.
bfd/ChangeLog:
2010-10-14 Dave Korn <dave.korn.cygwin@gmail.com>
Apply LD plugin patch series (part 6/6).
* aoutx.h (aout_link_check_ar_symbols): Take new "subsbfd" reference
parameter and pass it when invoking add_archive_element callback.
(aout_link_check_archive_element): Handle substitute bfd if it
was set during add_archive_element callback in the above.
* cofflink.c (coff_link_check_ar_symbols): Take new "subsbfd" reference
parameter and pass it when invoking add_archive_element callback.
(coff_link_check_archive_element): Handle substitute bfd if it
was set during add_archive_element callback in the above.
* ecoff.c (read_ext_syms_and_strs): New function holds symbol-reading
code factored-out from ecoff_link_check_archive_element.
(reread_ext_syms_and_strs): Clear old symbols and call it.
(ecoff_link_check_archive_element): Use the above. Handle substitute
BFD if one is set by add_archive_element callback.
(ecoff_link_add_archive_symbols): Likewise allow bfd substitution.
* elflink.c (elf_link_add_archive_symbols): Likewise.
* linker.c (generic_link_check_archive_element): Likewise.
* pdp11.c (aout_link_check_ar_symbols): Take new "subsbfd" reference
parameter and pass it when invoking add_archive_element callback.
(aout_link_check_archive_element): Handle substitute bfd if it was
set during add_archive_element callback in the above.
* vms-alpha.c (alpha_vms_link_add_archive_symbols): Handle substitute
BFD if one is set by add_archive_element callback.
* xcofflink.c (xcoff_link_check_dynamic_ar_symbols): Take new "subsbfd"
reference parameter and pass it when invoking add_archive_element
callback.
(xcoff_link_check_ar_symbols): Likewise.
(xcoff_link_check_archive_element): Handle bfd substitution if it was
set by callback in the above.
include/ChangeLog:
2010-10-14 Dave Korn <dave.korn.cygwin@gmail.com>
Apply LD plugin patch series (part 6/6).
* bfdlink.h (struct_bfd_link_callbacks): Document new argument
to add_archive_element callback used to return a replacement bfd which
is to be added to the hash table in place of the original element.
ld/ChangeLog:
2010-10-14 Dave Korn <dave.korn.cygwin@gmail.com>
Apply LD plugin patch series (part 6/6).
* ldlang.c (load_symbols): Handle bfd subsitution when calling the
add_archive_element callback.
* ldmain.c (add_archive_element)[ENABLE_PLUGINS]: Offer the archive
member to the plugins and if claimed set "subsbfd" output parameter to
point to the dummy IR-only BFD.
ld/testsuite/ChangeLog:
2010-10-14 Dave Korn <dave.korn.cygwin@gmail.com>
Apply LD plugin patch series (part 6/6).
* ld-plugin/plugin-10.d: New dump test control script.
* ld-plugin/plugin-11.d: Likewise.
* ld-plugin/plugin.exp: Run them.
---
* ld.h (struct args_type): Rename 'relax' field to
'disable_target_specific_optimizations' and turn it into a
tri-state variable.
(RELAXATION_DISABLED_BY_DEFAULT): New macro.
(RELAXATION_DISABLED_BY_USER): New macro.
(RELAXATION_ENABLED): New macro.
(DISABLE_RELAXATION): New macro.
(ENABLE_RELAXATION): New macro.
* lexsup (enum option_values): Add OPTION_NO_RELAX.
(struct ld_options): Add --no-relax.
(parse_args): Handle OPTION_NO_RELAX. Use DISABLE_RELAXATION and
ENABLE_RELAXATION macros.
* ldlang.c (lang_relax_sections): Use RELAXATION_ENABLED macro.
(lang_process): Likewise.
* ldmain.c (main): Initialise
disable_target_specific_optimizations field.
(multiple_definition): Use RELAXATION_ENABLED macro.
* ld.texinfo: Document new command line option.
* emultempl/alphaelf.em: Remove --no-relax option.
(before_allocation): Test RELAXATION_DISABLED_BY_USER macro.
Use ENABLE_RELAXATION macro.
* emultempl/avrelf.em: (after_allocation): Test RELAXATION_ENABLED
macro.
* emultempl/cr16elf.em: Remove --no-relax option.
(before_allocation): Test RELAXATION_DISABLED_BY_USER macro.
Use ENABLE_RELAXATION macro.
* emultempl/crxelf.em: Remove --no-relax option.
(before_allocation): Test RELAXATION_DISABLED_BY_USER macro.
Use ENABLE_RELAXATION macro.
* emultempl/mmix-elfnmmo.em: (before_allocation): Use
ENABLE_RELAXATION macro.
* emultempl/needrelax.em: (before_allocation): Use
ENABLE_RELAXATION macro.
* emultempl/ppc32elf.em: (before_allocation): Test
RELAXATION_DISABLED_BY_DEFAULT macro. Use
ENABLE_RELAXATION macro.
* emultempl/sh64elf.em: (before_allocation): Test
RELAXATION_ENABLED macro. Use DISABLE_RELAXATION macro.
* emultempl/xtensaelf.em: Remove --no-relax option.
(before_allocation): Test RELAXATION_ENABLED macro.
Use ENABLE_RELAXATION macro.
* ldlang.h (struct lang_input_statement_struct): Rename add_needed
to add_DT_NEEDED_for_dynamic. Rename as_needed to
add_DT_NEEDED_for_regular.
* ldlang.c: Likewise.
* ldlang.h: Likewise.
* ldlang.c: Use the new variable names.
* ldgram.y: Likewise.
* emultempl/elf32.em: Likewise.
* ld.texinfo: Document the renamed option. Also mention its
affect on the resolution of dynamic symbols.
* NEWS: Mention the changed option name.
* ld.h (args_type): Make check_section_addresses a char.
ldlang.c (lang_process): Don't consider relocatable flag when
checking for overlap.
* ldmain.c (main): Default check_section_addresses to -1. Check it
for relocatable links.
* ld.texinfo (--check-sections): Update documentation.
* testsuite/ld-elfcomm/elfcomm.exp (test_sort_common): Test the
ascending/descending argument to the --sort-common command line
option.
* testsuite/ld-elfcomm/sort-common.s: New file.
* ld.h (enum sort_order): New.
* ldlang.c (lang_check: Fix comment.
(lang_common): Sort commons in ascending or descending order.
(lang_one_common): Likewise.
* lexsup.c (ld_options): Have --sort-common take an option
argument.
(parse_args): Handle argument to --sort-common.
* ld.texinfo (--sort-common): Document new optional argument.
* NEWS: Mention new feature.
* ld.h (ld_config_type): Add rpath_separator.
* ldmain.c (main): Initialize it.
* lexsup.c (parse_args): Honor config.rpath_separator.
* emultempl/elf32.em (gld${EMULATION_NAME}_search_needed): Likewise.
(gld${EMULATION_NAME}_add_sysroot): Likewise.
(gld${EMULATION_NAME}_parse_ld_so_conf): Use config.rpath_separator
rather than ':' when building the path.
* emultempl/vxworks.em (vxworks_before_parse): New function.
Override config.rpath_separator.
(LDEMUL_AFTER_OPEN): Do not change if EXTRA_EM_FILE has been
set to gld${EMULATION_NAME}_after_open; #define that identifier
to vxworks_foo instead.
(LDEMUL_BEFORE_PARSE): Override in the same way as LDEMUL_AFTER_OPEN.
ld/testsuite/
* ld-vxworks/rpath-1.s, ld-vxworks/rpath-1.d,
* ld-vxworks/vxworks.exp: New files.
2007-01-19 H.J. Lu <hongjiu.lu@intel.com>
* ld.h (args_type): Add new symbolic and dynamic_list fields.
* ld.texinfo: Update -Bsymbolic-functions.
* ldmain.c (main): Initialize command_line.symbolic to
symbolic_unset and command_line.dynamic_list to
dynamic_list_unset. Check -Bsymbolic, -Bsymbolic-functions and
--dynamic-list* before setting link_info.symbolic,
link_info.dynamic and link_info.dynamic_data.
* lexsup.c (option_values): Add OPTION_SYMBOLIC_FUNCTIONS.
(ld_options): Use OPTION_SYMBOLIC_FUNCTIONS with
-Bsymbolic-functions.
(parse_args): Handle -Bsymbolic-functions. Don't set
link_info.dynamic, link_info.dynamic_data and link_info.symbolic
here. Set command_line.symbolic for -Bsymbolic. Set
command_line.dynamic_list and command_line.symbolic for
--dynamic-list-data, --dynamic-list-cpp-new,
--dynamic-list-cpp-typeinfo and --dynamic-list.
ld/testsuite/
2007-01-19 H.J. Lu <hongjiu.lu@intel.com>
* ld-elf/dl6.c: New file.
* ld-elf/dl6a.out: Likewise.
* ld-elf/dl6amain.c: Likewise.
* ld-elf/dl6b.out: Likewise.
* ld-elf/dl6bmain.c: Likewise.
* ld-elf/dl6cmain.c: Likewise.
* ld-elf/dl6dmain.c: Likewise.
* ld-elf/shared.exp: Add new tests for -Bsymbolic,
-Bsymbolic-functions, --dynamic-list-data and
--dynamic-list-cpp-new.
2007-01-16 H.J. Lu <hongjiu.lu@intel.com>
PR ld/3831
* elf-bfd.h (bfd_elf_link_mark_dynamic_symbol): Add an
argument, Elf_Internal_Sym *.
* elflink.c (bfd_elf_link_mark_dynamic_symbol): Mark a data
symbol dynamic if info->dynamic_data is TRUE.
(bfd_elf_record_link_assignment): Updated call to
bfd_elf_record_link_assignment.
(_bfd_elf_merge_symbol): Likewise. Always call
bfd_elf_link_mark_dynamic_symbol.
include/
2007-01-16 H.J. Lu <hongjiu.lu@intel.com>
PR ld/3831
* bfdlink.h (bfd_link_info): Rename dynamic to dynamic_list.
Add dynamic and dynamic_data.
ld/
2007-01-16 H.J. Lu <hongjiu.lu@intel.com>
PR ld/3831
* NEWS: Mention -Bsymbolic-functions, --dynamic-list-data and
--dynamic-list-cpp-new.
* ld.texinfo: Document -Bsymbolic-functions, --dynamic-list-data
and --dynamic-list-cpp-new.
* ldlang.c (lang_append_dynamic_list_cpp_new): New.
(lang_process): Change link_info.dynamic to
link_info.dynamic_list.
(lang_append_dynamic_list): Likewise.
* ldmain.c (main): Likewise. Initialize link_info.dynamic and
link_info.dynamic_data to FALSE.
* ldlang.h (lang_append_dynamic_list_cpp_new): New.
* lexsup.c (option_values): Add OPTION_DYNAMIC_LIST_DATA and
OPTION_DYNAMIC_LIST_CPP_NEW.
(ld_options): Add entries for -Bsymbolic-functions,
--dynamic-list-data and --dynamic-list-cpp-new. Make
-Bsymbolic-functions an alias of --dynamic-list-data.
(parse_args): Change link_info.dynamic to link_info.dynamic_list.
Set link_info.dynamic to TRUE for --dynamic-list and
--dynamic-list-cpp-typeinfo. Handle --dynamic-list-data and
--dynamic-list-cpp-new.
ld/testsuite/
2007-01-16 H.J. Lu <hongjiu.lu@intel.com>
PR ld/3831
* ld-elf/del.cc: New.
* ld-elf/dl5.cc: Likewise.
* ld-elf/dl5.out: Likewise.
* ld-elf/new.cc: Likewise.
* ld-elf/shared.exp: Add tests for --dynamic-list-data and
--dynamic-list-cpp-new.
argument and emits the string followed by a comma and then the length of
the string.
(CONST_STRNEQ): New macro. Checks to see if a variable string has a constant
string as its initial characters.
(CONST_STRNCPY): New macro. Copies a constant string to the start of a
variable string.
* bfd-in2.h: Regenerate.
* <remainign files>: Make use of the new macros.
* lexsup.c: Add --print-gc-sections and --no-print-gc-sections switches.
* ld.texinfo: Document new switches.
* NEWS: Mention new switches.
* bfdlink.h (struct bfd_link_info): New field: print_gc_sections.
* elflink.c (elf_gc_sweep): If info.print_gc_sections is true, list removed sections to stderr.
* ldmain.c (ld_sysroot): Likewise.
(get_relative_sysroot, get_sysroot): New functions, adding command-line
support for changing the sysroot.
(main): Call the new functions.
* lexsup.c (OPTION_SYSROOT): New.
(ld_options): Add --sysroot.
(parse_args): Add a dummy handler for it.
* ld.texinfo (--sysroot): Document.
* NEWS: Mention the new --sysroot option.
