e7c3341679
* common.h (STT_IFUNC): Define.
elfcpp/
* elfcpp.h (enum STT): Add STT_IFUNC.
bfd/
* syms.c (struct bfd_symbol): Add new flag BSF_INDIRECT_FUNCTION.
Remove redundant flag BFD_FORT_COMM_DEFAULT_VALUE. Renumber flags
to remove gaps.
(bfd_print_symbol_vandf): Return 'i' for BSF_INDIRECT_FUNCTION.
(bfd_decode_symclass): Likewise.
* elf.c (swap_out_syms): Translate BSF_INDIRECT_FUNCTION into
STT_IFUNC.
(elf_find_function): Treat STT_IFUNC in the same way as STT_FUNC.
(_bfd_elf_is_function_type): Likewise.
* elf32-arm.c (arm_elf_find_function): Likewise.
(elf32_arm_adjust_dynamic_symbol): Likewise.
(elf32_arm_swap_symbol_in): Likewise.
(elf32_arm_additional_program_headers): Likewise.
* elf32-i386.c (is_indirect_symbol): New function.
(elf_i386_check_relocs): Also generate dynamic relocs for
relocations against STT_IFUNC symbols.
(allocate_dynrelocs): Likewise.
(elf_i386_relocate_section): Likewise.
* elf64-x86-64.c (is_indirect_symbol): New function.
(elf64_x86_64_check_relocs): Also generate dynamic relocs for
relocations against STT_IFUNC symbols.
(allocate_dynrelocs): Likewise.
(elf64_x86_64_relocate_section): Likewise.
* elfcode.h (elf_slurp_symbol_table): Translate STT_IFUNC into
BSF_INDIRECT_FUNCTION.
* elflink.c (_bfd_elf_adjust_dynamic_reloc_section): Add support
for STT_IFUNC symbols.
(get_ifunc_reloc_section_name): New function.
(_bfd_elf_make_ifunc_reloc_section): New function.
* elf-bfd.h (struct bfd_elf_section_data): Add indirect_relocs field.
* bfd-in2.h: Regenerate.
gas/
* config/obj-elf.c (obj_elf_type): Add support for STT_IFUNC type.
* doc/as.texinfo: Document new feature.
* NEWS: Mention new feature.
gas/testsuite/
* gas/elf/type.s: Add test of STT_IFUNC symbol type.
* gas/elf/type.e: Update expected disassembly.
* gas/elf/elf.exp: Update grep of symbol types.
ld/
* NEWS: Mention new feature.
* pe-dll.c (process_def_file): Replace use of redundant
BFD_FORT_COMM_DEFAULT_VALUE with 0.
* scripttempl/elf.sc: Add .rel.ifunc.dyn and .rela.ifunc.dyn
sections.
ld/testsuite/
* ld-mips-elf/reloc-1-n32.d: Updated expected output for reloc
descriptions.
* ld-mips-elf/reloc-1-n64.d: Likewise.
* ld-i386/ifunc.d: New test.
* ld-i386/ifunc.s: Source file for the new test.
* ld-i386/i386.exp: Run the new test.
453 lines
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453 lines
17 KiB
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-*- text -*-
|
||
* For GNU/Linux systems the linker will now forego processing any relocations
|
||
made against symbols of the STT_IFUNC type and instead emit them into
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||
the resulting binary for processing by the loader.
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||
|
||
* Add CR16 ELF --embedded-relocs (used to embedded relocations into binaries
|
||
for Embedded-PIC code) option.
|
||
|
||
* Add to the PE/PE+ targets the support of two different kinds of
|
||
pseudo-relocations. They can be selected by the switches
|
||
--enable-runtime-pseudo-reloc-v1 and --enable-runtime-pseudo-reloc-v2.
|
||
For the switch --enable-runtime-pseudo-reloc it uses for 32-bit
|
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runtime pseudo relocation version one, for 64-bit the version two.
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||
|
||
Changes in 2.19:
|
||
|
||
* Linker scripts support a new INSERT command that makes it easier to
|
||
augment the default script.
|
||
|
||
* Linker script input section filespecs may now specify a file within an
|
||
archive by writing "archive:file".
|
||
|
||
* The --sort-common switch now has an optional argument which specifies the
|
||
direction of sorting.
|
||
|
||
* The M68K linker now supports multiple GOT generation schemes controlled via
|
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the --got=<type> command line option.
|
||
|
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* The ARM EABI linker will now generate stubs for function calls to symbols
|
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that are too far away. The placement of the stubs is controlled by a new
|
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linker command line option: --stub-group-size=N.
|
||
|
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Changes in 2.18:
|
||
|
||
* Linker sources now released under version 3 of the GNU General Public
|
||
License.
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||
|
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* ELF: New --build-id option to generate a unique per-binary identifier
|
||
embedded in a note section.
|
||
|
||
* Added support for National Semicondutor CompactRISC (ie CR16) target.
|
||
|
||
* -l:foo now searches the library path for a filename called foo,
|
||
without converting it to libfoo.a or libfoo.so.
|
||
|
||
* Add a new command line option '--default-script=FILE' or '-dT FILE'
|
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which specifies a replacement for the built in, default linker
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||
script.
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||
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* ELF: Add -Bsymbolic-functions, --dynamic-list-cpp-new, which puts C++
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operator new and delete on the dynamic list, and --dynamic-list-data,
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builtin list for --dynamic-list, which puts global data symbols on the
|
||
dynamic list.
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||
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* Add support for x86_64 PE+ target.
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* Add support for Score target.
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* ELF: Add --dynamic-list option to specify a list of global symbols
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whose references shouldn't be bound to the definition within the
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shared library, or a list of symbols which should be added to the
|
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symbol table in the executable.
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||
|
||
* The default output section LMA has changed for allocatable sections from
|
||
being equal to VMA, to keeping the difference between LMA and VMA the same as
|
||
the previous output section in the same region. This is a more useful
|
||
default when using overlays and other cases where you specify an LMA
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||
differing from the VMA for some sections.
|
||
|
||
* New switch: --print-gc-sections to list any sections removed by garabge
|
||
collection.
|
||
|
||
* ARM: Added --vfp11-denorm-fix option to work around an erratum in current
|
||
VFP11 coprocessors.
|
||
|
||
Changes in 2.17:
|
||
|
||
* Support for the Infineon XC16X has been added by KPIT Cummins Infosystems.
|
||
|
||
* Modify the Linux linker search order to better match ld.so search order.
|
||
Look for DT_NEEDED libraries in paths specified by ld.so.conf before
|
||
searching the default directories, rather than vice versa.
|
||
Use $prefix/etc/ld.so.conf if it exists, otherwise /etc/ld.so.conf.
|
||
|
||
* PE-COFF: Forward exports from DLL's can now be specified in .def files
|
||
passed directly to ld.
|
||
|
||
* Support for the Z80 processor family has been added.
|
||
|
||
* Add support for the "@<file>" syntax to the command line, so that extra
|
||
switches can be read from <file>.
|
||
|
||
Changes in 2.16:
|
||
|
||
* Support for the R_ARM_V4BX relocation as defined in the ARM AAELF
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specification has been added via the --fix-v4bx command-line option.
|
||
|
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* New linker script construct AS_NEEDED(), which sets the --as-needed flag
|
||
for input files listed inside of it.
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||
|
||
* A new command-line option, --sysroot, can be used to override the
|
||
default sysroot location. It only applies to toolchains that were
|
||
configured using --with-sysroot.
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||
|
||
* New linker script functions: ORIGIN() and LENGTH() which return information
|
||
about a specified memory region.
|
||
|
||
* Port to MAXQ processor contributed by HCL Tech.
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||
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* Added SEGMENT_START to the linker script language to permit the user to
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||
override the base address for a segment from the command-line.
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||
|
||
* ELF: --warn-shared-textrel option to warn if adding a DT_TEXTREL to a shared
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||
object.
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* Added SORT_BY_NAME and SORT_BY_ALIGNMENT to the linker script
|
||
language to permit sorting sections by section name or section
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||
maximum alignment.
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||
|
||
* Added a new linker command line switch, --sort-section name|alignment,
|
||
to sort sections by section name or maximum alignment.
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||
|
||
* ELF: --add-needed/--no-add-needed options to control if a DT_NEEDED tag
|
||
should be added when a shared library comes from DT_NEEDED tags.
|
||
|
||
* Support for the crx-elf target added.
|
||
|
||
* Support for the sh-symbianelf target added.
|
||
|
||
* A new linker command line switch has been added which allows the hash table
|
||
size to be set to a suitable prime value near to its argument. This switch
|
||
is --hash-size=<NUMBER>. Also if the switch --reduce-memory-overheads is
|
||
used, and --hash-size has not been used, then the default value will be set
|
||
to 1021.
|
||
|
||
* Linker map files are now generated with an O(N) algorithm for finding symbols
|
||
that are defined in each section. This uses about 40% more memory for
|
||
symbols than the old O(N^2) algorithm. You can use the new
|
||
--reduce-memory-overheads option to select the old algorithm; this option
|
||
might also be used in the future to select similar tradeoffs.
|
||
|
||
Changes in 2.15:
|
||
|
||
* ELF: --as-needed/--no-as-needed options to control if a DT_NEEDED tag should
|
||
be added only when a shared library is referenced.
|
||
|
||
* PE: --large-address-aware option to indicate executables support virtual
|
||
addresses greater than 2 gigabytes.
|
||
|
||
* DWARF 2 support for i386pe added.
|
||
|
||
* The linker script operator DEFINED() will now yield 1 only for a symbol that
|
||
is defined before the statement where DEFINED is used.
|
||
|
||
* The MIPS --embedded-relocs (used to embed relocations into binaries for
|
||
Embedded-PIC code) is deprecated and will be removed in a future release.
|
||
|
||
* cr16c support added by NSC.
|
||
|
||
* m32r Linux (ELF) support added by Renesas.
|
||
|
||
* Improved linker's handling of unresolved symbols. The switch
|
||
--unresolved-symbols=<method> has been added to tell the linker when it
|
||
should report them and the switch --warn-unresolved-symbols has been added to
|
||
make reports be issued as warning messages rather than errors.
|
||
|
||
Changes in 2.14:
|
||
|
||
* Added support for Xtensa architecture.
|
||
|
||
* Added --with-sysroot configure switch to specify a target system root, for
|
||
linking against a target filesystem image.
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||
|
||
* Added --accept-unknown-linker-format to restore old linker behaviour (pre
|
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2.14) of silently accepting and linking in any files in an unknown binary
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||
file format.
|
||
|
||
* Added --no-omagic to undo the effects of the -N option.
|
||
|
||
* Support for Texas Instruments TMS320C4x and TMS320C3x series of
|
||
DSP's contributed by Michael Hayes and Svein E. Seldal.
|
||
|
||
* Added --with-lib-path configure switch to specify default value for
|
||
LIB_PATH.
|
||
|
||
* ARM port to QNX operating system added by Graeme Peterson.
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||
|
||
* IP2K support added by Denis Chertykov.
|
||
|
||
Changes in 2.13:
|
||
|
||
* Support for the Fujitsu FRV architecture added by Red Hat. Models for FR400
|
||
and FR500 included.
|
||
|
||
Changes in version 2.13:
|
||
|
||
* DEC VAX ELF support, by Matt Thomas.
|
||
|
||
Changes in version 2.12:
|
||
|
||
* Support for Don Knuth's MMIX, by Hans-Peter Nilsson.
|
||
|
||
* Support for the OpenRISC 32-bit embedded processor by OpenCores.
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||
|
||
* Support for -z nocopyreloc in the x86 ELF linker, which disables
|
||
production of copy relocs. Warning: using this option may result in
|
||
non-sharable applications.
|
||
|
||
* Support for -z combreloc in the ELF linker, which puts dynamic
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||
relocations against the same symbol together, so that dynamic linker
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||
can use an one-entry symbol lookup cache.
|
||
|
||
* Support for ELF SHF_MERGE section merging, by Jakub Jelinek.
|
||
|
||
Changes in version 2.11:
|
||
|
||
* Support for AMD x86-64 architecture, by Jan Hubicka, SuSE Labs.
|
||
|
||
* Support added for eliminating duplicate DWARF2 debug information by
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having the compiler generate the information in sections called
|
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.gnu.linkonce.wi.XXXX where XXXX is a checksum for the contents. The
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||
linker then merges these sections together into the normal .debug_info
|
||
section.
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||
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* The native ELF linker now searches the directories in DT_RUNPATH or
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DT_RPATH of a shared library for shared libraries needed by it.
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||
|
||
* TI C54x support, by Timothy Wall.
|
||
|
||
* Added command line switch --section-start to set the start address of any
|
||
specified section.
|
||
|
||
* Added ability to emit full relocation information in linked executables,
|
||
enabled by --emit-relocs. Some post-linkage optimization tools need
|
||
this information in order to be able to correctly identify and perform
|
||
symbol relative addressing in the event of changes in section contents
|
||
(instructions being added or deleted, extending data sections, etc.)
|
||
|
||
* Support for i860, by Jason Eckhardt (preliminary, alpha quality).
|
||
|
||
* Support for CRIS (Axis Communications ETRAX series).
|
||
|
||
* Support for PDP-11 and 2.11BSD a.out format, by Lars Brinkhoff.
|
||
|
||
Changes in version 2.10:
|
||
|
||
* Added AT> to the linker script language to allow load-time allocation of
|
||
sections into regions.
|
||
|
||
* Added garbage collection of unused sections, enabled by --gc-sections.
|
||
It does require a bit of backend support; currently implemented are
|
||
arm-elf, avr-elf, d10v-elf, fr30-elf, i386-elf, m32r-elf, m68k-elf,
|
||
mcore-elf, mips-elf, mn10300-elf, ppc-elf, sh-elf, sparc-elf, and v850-elf.
|
||
Others will ignore the option.
|
||
|
||
* Added SORT to the linker script language to permit sorting sections by file
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||
name or section name.
|
||
|
||
* Added EXTERN to the linker script language as an equivalent to the -u
|
||
command-line option.
|
||
|
||
* Added ASSERT to the linker script language.
|
||
|
||
* Added EXCLUDE_FILE to the linker script language for further control over
|
||
wildcard file names.
|
||
|
||
* Added -O option to optimize linker output (as of this writing, this only
|
||
affects ELF shared library generation).
|
||
|
||
* The -e option now accepts a number as well as a symbol name.
|
||
|
||
* Added --no-undefined option to disallow undefined symbols when creating a
|
||
shared library.
|
||
|
||
* The linker now issues a warning, not an error, for an undefined symbol when
|
||
using -Bsymbolic; use the new --no-undefined option to get the old
|
||
behaviour.
|
||
|
||
* Added --demangle and --no-demangle options.
|
||
|
||
Changes in version 2.9:
|
||
|
||
* Added SQUAD to the linker script language.
|
||
|
||
* New option --no-warn-mismatch.
|
||
|
||
* The MEMORY command now parses the attributes to determine where sections that
|
||
are not placed in a specific memory region are placed.
|
||
|
||
Changes in version 2.8:
|
||
|
||
* Linker scripts may now contain shell wildcard characters for file and section
|
||
names.
|
||
|
||
* The linker now supports symbol versions in ELF.
|
||
|
||
* The NOCROSSREFS command was added to the linker script language.
|
||
|
||
* The LOADADDR expression was added to the linker script language.
|
||
|
||
* MAX and MIN functions were added to the linker script language.
|
||
|
||
* The OVERLAY construct was added to the linker script language.
|
||
|
||
* New option --warn-section-align to warn when the address of an output section
|
||
changes due to alignment of an input section.
|
||
|
||
* New options --filter/-F and --auxiliary/-f.
|
||
|
||
Changes in version 2.7:
|
||
|
||
* New option --cref to print out a cross reference table.
|
||
|
||
* New option --wrap SYMBOL.
|
||
|
||
* New option --no-whole-archive, to turn off the effect of --whole-archive.
|
||
|
||
* Input sections assigned to the output section /DISCARD/ in the linker script
|
||
are not included in the output file.
|
||
|
||
* The SunOS and ELF linkers now merge stabs debugging information which uses
|
||
the N_BINCL and N_EINCL stab types. This reduces the amount of debugging
|
||
information generated.
|
||
|
||
Changes in version 2.6:
|
||
|
||
* When an ELF section name is representable as a C identifier (this is not true
|
||
of most ELF section names), the linker will automatically define symbols
|
||
__start_SECNAME and __stop_SECNAME, where SECNAME is the section name, at the
|
||
beginning and the end of the section. This is used by glibc.
|
||
|
||
Addendum: Current versions of the linker (at least for version 2.18 onwards
|
||
and possibly much earlier as well) place two restrictions on this feature: The
|
||
symbols are only implemented for orphaned sections, not for explicitly placed
|
||
sections and they are PROVIDEd rather than being defined.
|
||
|
||
* When an ELF section named .gnu.warning is encountered in an input file, the
|
||
contents of the section are displayed as an error message, and the section is
|
||
not copied into the output file. This is used by glibc.
|
||
|
||
* When an ELF section named .gnu.warning.SYMBOL is encountered in an input
|
||
file, and the symbol SYMBOL is referenced by some object file, the contents of
|
||
the section are displayed as an error message. The section is not copied into
|
||
the output file, unless doing a relocatable or shared link. This is used by
|
||
glibc.
|
||
|
||
* New options -split-by-reloc and -split-by-file.
|
||
|
||
* The linker now supports linking PIC compiled code on SPARC SunOS. It can
|
||
also create SPARC SunOS shared libraries, and, like the native SunOS linker,
|
||
will do so whenever there is an undefined symbol in the link and neither the -e
|
||
nor the -r option was used.
|
||
|
||
* The -rpath option may be used on SunOS to set the list of directories to be
|
||
searched at run time. This overrides the default of building the list from the
|
||
-L options.
|
||
|
||
* The COFF linker now combines debugging information for structs, unions, and
|
||
enums, so that even if the same type is defined in multiple input files it will
|
||
only be defined once in the output file. The --traditional-format switch will
|
||
prevent this optimization.
|
||
|
||
Changes in version 2.5:
|
||
|
||
* The linker now supports linking against SunOS shared libraries. It still can
|
||
not link SunOS PIC (Position Independent Code) files, so it can not be used to
|
||
generate shared libraries.
|
||
|
||
* The linker now supports linking against ELF shared libraries for the i386
|
||
(UnixWare) and SPARC (Solaris). It can also link ELF PIC files, and can be
|
||
used to generate shared libraries. Shared library generation is not well
|
||
tested; please report any problems encountered. The linker is now enabled for
|
||
Solaris again.
|
||
|
||
* Eric Youngdale has contributed Linux support code, including linking against
|
||
Linux a.out shared libraries. The linker produces Linux QMAGIC binaries.
|
||
|
||
* The ELF backend has been converted to the new linker code. To use the new
|
||
ELF linker, each particular target requires a relocation function. So far,
|
||
this function has been written for i386 (UnixWare), SPARC (Solaris) MIPS (Irix
|
||
5), and HPPA ELF targets.
|
||
|
||
* The -( (--start-group) and -) (--end-group) options have been added to
|
||
support searching a group of archives as though they were a single archive.
|
||
This can also be used in a linker script, as GROUP ( files ).
|
||
|
||
* When a file is named on the command line, and the linker does not recognize
|
||
it as an object file, the linker will now treat the file as a linker script
|
||
file. A linker script named in this way augments, but does not replace, the
|
||
default linker script.
|
||
|
||
* The -warn-once option was added. It causes the linker to only warn once per
|
||
undefined symbol, rather than once per reference.
|
||
|
||
* The COFF backend has been converted to the new linker code. As with ELF, to
|
||
use the new linker, each particular target requires a relocation function. So
|
||
far, this function has been written for the i386, m68k, a29k and SH targets.
|
||
|
||
* The -V flag was made a synonym for -v, for SVR4 compatibility. The old -V
|
||
behaviour is available via --verbose.
|
||
|
||
Changes in version 2.4:
|
||
|
||
* New linker code, by Steve Chamberlain and Ian Taylor. For a.out and ecoff
|
||
formats (so far), this should result in considerable savings in time
|
||
and memory used while linking; slightly poorer performance than
|
||
before for formats not converted yet.
|
||
|
||
* Command-line parsing is no longer done with flex. This means
|
||
oddball characters in filenames won't get treated as argument
|
||
separators.
|
||
|
||
* HP-PA ELF support, by Jeff Law. (No SOM support yet.)
|
||
|
||
* Mach i386 support, by David Mackenzie.
|
||
|
||
* Irix 4 shared libraries are now supported (Irix 5 uses ELF, and ELF shared
|
||
libraries are not yet supported).
|
||
|
||
* COFF shared libraries (as on SCO) should work as well.
|
||
|
||
* The linker is disabled for Solaris. (Actually, it was in 2.3 also, I just
|
||
forgot to note it.) Some of their C library routines don't work when
|
||
statically linked, and the GNU linker doesn't support dynamic linking yet.
|
||
|
||
Changes in version 2.3:
|
||
|
||
* Weak symbols are now supported.
|
||
|
||
* ELF support has been added. The linker has been bootstrapped on
|
||
UnixWare and Solaris.
|
||
|
||
* Alpha OSF/1 support has been added (non dynamic linking only).
|
||
|
||
Changes in version 2.2:
|
||
|
||
* The `bfd' library has been updated to reduce a.out-format string
|
||
table size. The effect of this is that files linked from many input
|
||
files with duplicate symbols (`-g' debugging records, or identical
|
||
static symbols) should be much smaller.
|
||
|
||
Changes in version 2.1:
|
||
|
||
* The ld -ySYMBOL flag (to trace references to SYMBOL) is now implemented.
|
||
|
||
* There is now support for writing ECOFF files, so ld and the
|
||
other utilities should work on Risc/Ultrix and Irix.
|
||
|
||
|
||
Local variables:
|
||
fill-column: 79
|
||
End:
|