5 * Support for -z shstk in the x86 ELF linker to generate
6 GNU_PROPERTY_X86_FEATURE_1_SHSTK in ELF GNU program properties.
8 * Add support for GNU_PROPERTY_X86_FEATURE_1_SHSTK in ELF GNU program
9 properties in the x86 ELF linker.
11 * Add support for GNU_PROPERTY_X86_FEATURE_1_IBT in ELF GNU program
12 properties in the x86 ELF linker.
14 * Support for -z ibtplt in the x86 ELF linker to generate IBT-enabled
17 * Support for -z ibt in the x86 ELF linker to generate IBT-enabled
18 PLT as well as GNU_PROPERTY_X86_FEATURE_1_IBT in ELF GNU program
21 * Add support for ELF SHF_GNU_MBIND and PT_GNU_MBIND_XXX.
23 * Add support for ELF GNU program properties.
25 * Add support for the Texas Instruments PRU processor.
27 * When configuring for arc*-*-linux* targets the default linker emulation will
28 change if --with-cpu=nps400 is used at configure time.
30 * Improve assignment of LMAs to orphan sections in some edge cases where a
31 mixture of both AT>LMA_REGION and AT(LMA) are used.
33 * Orphan sections placed after an empty section that has an AT(LMA) will now
34 take an load memory address starting from LMA.
36 * Section groups can now be resolved (the group deleted and the group members
37 placed like normal sections) at partial link time either using the new linker
38 option --force-group-allocation or by placing FORCE_GROUP_ALLOCATION into the
43 * The EXCLUDE_FILE linker script construct can now be applied outside of the
44 section list in order for the exclusions to apply over all input sections in
47 * Add support for the RISC-V architecture.
49 * The command line option --no-eh-frame-hdr can now be used in ELF based
50 linkers to disable the automatic generation of .eh_frame_hdr sections.
52 * Add --in-implib=<infile> to the ARM linker to enable specifying a set of
53 Secure Gateway veneers that must exist in the output import library specified
54 by --out-implib=<outfile> and the address they must have. As such,
55 --in-implib is only supported in combination with --cmse-implib.
57 * Extended the --out-implib=<file> option, previously restricted to x86 PE
58 targets, to any ELF based target. This allows the generation of an import
59 library for an ELF executable, which can then be used by another application
60 to link against the executable.
64 * Add a configure option --enable-relro to decide whether -z relro should
65 be enabled in ELF linker by default. Default to yes for all Linux
66 targets except FRV, HPPA, IA64 and MIPS.
68 * Support for -z noreloc-overflow in the x86-64 ELF linker to disable
69 relocation overflow check.
71 * Add -z common/-z nocommon options for ELF targets to control whether to
72 convert common symbols to the STT_COMMON type during a relocatable link.
74 * Support for -z nodynamic-undefined-weak in the x86 ELF linker, which
75 avoids dynamic relocations against undefined weak symbols in executable.
77 * The NOCROSSREFSTO command was added to the linker script language.
79 * Add --no-apply-dynamic-relocs to the AArch64 linker to do not apply link-time
80 values for dynamic relocations.
84 * Add --fix-stm32l4xx-629360 to the ARM linker to enable a link-time
85 workaround for a bug in the bus matrix / memory controller for some of
86 the STM32 Cortex-M4 based products (STM32L4xx)
88 * Add a configure option --enable-compressed-debug-sections={all,ld} to
89 decide whether DWARF debug sections should be compressed by default.
91 * Add support for the ARC EM/HS, and ARC600/700 architectures.
93 * Experimental support for linker garbage collection (--gc-sections)
94 has been enabled for COFF and PE based targets.
96 * New command line option for ELF targets to compress DWARF debug
97 sections, --compress-debug-sections=[none|zlib|zlib-gnu|zlib-gabi].
99 * New command line option, --orphan-handling=[place|warn|error|discard], to
100 adjust how orphan sections are handled. The default is 'place' which gives
101 the current behaviour, 'warn' and 'error' issue a warning or error
102 respectively when orphan sections are found, and 'discard' will discard all
105 * Add support for LLVM plugin.
107 * Add --print-memory-usage option to report memory blocks usage.
109 * Add --require-defined option, it's like --undefined except the new symbol
110 must be defined by the end of the link.
114 * PE binaries now once again contain real timestamps by default. To disable
115 the inclusion of a timestamp in a PE binary, use the --no-insert-timestamp
118 * Replace support for openrisc and or32 with support for or1k.
120 * Add support for the --build-id command line option to COFF based targets.
122 * x86/x86_64 pe-coff now supports the --build-id option.
124 * Add support for the Andes NDS32.
128 * Add LOG2CEIL() builtin function to the linker script language
130 * Add support for the Texas Instruments MSP430X processor.
132 * Add support for Altera Nios II.
134 * Add support for the V850E3V5 architecture.
136 * Add support for the Imagination Technologies Meta processor.
138 * --enable-new-dtags no longer generates old dtags in addition to new dtags.
140 * Remove linker support for MIPS ECOFF targets.
142 * Add ALIGN_WITH_INPUT to the linker script language to force the alignment of
143 an output section to use the maximum alignment of all its input sections.
147 * Enable compressed debug section feature for x86/x86_64 pe-coff.
149 * Add support for the 64-bit ARM architecture: AArch64.
151 * Added SORT_NONE to the linker script language to disable section sorting.
153 * Add a linker-provided symbol when producing ELF output, '__ehdr_start'
154 to point to the ELF file header (and nearby program headers) in the
155 program's memory image.
157 * Add support for S12X processor.
159 * Add support for the VLE extension to the PowerPC architecture.
161 * Add support for the Freescale XGATE architecture.
163 * Add option -f FILE on AIX (for response file).
165 * Add support for the Renesas RL78 architecture.
167 * Add support for the Adapteva EPIPHANY architecture.
171 * --copy-dt-needed-entries is no longer enabled by default. Instead
172 --no-copy-dt-needed-entries is the default.
174 * INPUT_SECTION_FLAGS has been added to the linker script language
175 to allow selection of input sections by section header section flags.
177 * Add support for the Tilera TILEPro and TILE-Gx architectures.
179 * Added SORT_BY_INIT_PRIORITY to the linker script language to permit
180 sorting sections by numerical value of the GCC init_priority attribute
181 encoded in the section name.
185 * Linker script expression evaluation is somewhat more sane. This may
186 break scripts that depend on quirks of the old expression evaluation.
188 * Turn off underscoring for x86_64 PE+-COFF targets. For old behavior the
189 option --enable-leading-mingw64-underscores can be used on configure of
192 * Add support for the TMS320C6000 (TI C6X) processor family.
194 * --add-needed renamed to --copy-dt-needed-entries in order to avoid confusion
195 with --as-needed option.
197 * Extend .def file syntax by '== <ID>' for imports and exports. This allows
198 to alias the import/export table name written in PE image.
200 * Add --exclude-all-symbols option to PE based linkers. This prevents all
201 symbols from automatically being exported.
203 * Add support for the Renesas RX processor.
205 * Add support for alpha-vms target.
209 * GNU/Linux targets now support the STB_GNU_UNIQUE symbol binding. This is a
210 GNU extension to the standard set of ELF symbol bindings. The binding will
211 be passed on to the dynamic linker which will make sure that in the entire
212 process there is just one symbol with the given name and type in use.
214 * PE targets now support a GNU extension to allow the alignment of common
215 common symbols to be specified. This support uses custom options in
216 the .drectve section, which will be disregarded by the native tools.
218 * PE targets now add primitive support for ELF version scripts; symbols
219 are not versioned, but the local and global symbol visibility directives
220 are respected when filtering symbols in auto-export mode.
222 * New option --no-export-dynamic to undo the effect of the -E and
223 --export-dynamic options.
225 * ELF: --warn-alternate-em option to warn if an object has alternate
228 * New script function REGION_ALIAS to add alias names to memory regions.
230 * PE targets no longer make use of the long section names PE extension to
231 the COFF format when generating executable images, by default. The old
232 (slightly non-conformant) behaviour can still be invoked by using the
233 new '--enable-long-section-names' command-line option. It is also enabled
234 automatically in the presence of un-stripped debug information, as GDB
235 needs to be able to find the debug info sections by their full names.
237 * For GNU/Linux systems the linker will now avoid processing any relocations
238 made against symbols of the STT_GNU_IFUNC type and instead emit them into
239 the resulting binary for processing by the loader.
241 * --as-needed now links in a dynamic library if it satisfies undefined
242 symbols in regular objects, or in other dynamic libraries. In the
243 latter case the library is not linked if it is found in a DT_NEEDED
244 entry of one of the libraries already linked.
246 * Add a new command line option, -Ttext-segment ADDR, for ELF targets
247 to set the address of the first byte of the text segment.
249 * Add support for Sunplus score architecture.
251 * Add new option --use-nul-prefixed-import-tables to ld for PE targets to
252 allow fallback to old import table generation with null element prefix.
254 * Windows PE systems now support a new --exclude-modules-for-implib option,
255 allowing users to partition object files and archive members between a DLL
256 and its associated import library as they are generated during linking.
258 * Add support for Lattice Mico32 (lm32) architecture.
260 * Add CR16 ELF --embedded-relocs (used to embedded relocations into binaries
261 for Embedded-PIC code) option.
263 * Add to the PE/PE+ targets the support of two different kinds of
264 pseudo-relocations. They can be selected by the switches
265 --enable-runtime-pseudo-reloc-v1 and --enable-runtime-pseudo-reloc-v2.
266 For the switch --enable-runtime-pseudo-reloc it uses for 32-bit
267 runtime pseudo relocation version one, for 64-bit the version two.
271 * Linker scripts support a new INSERT command that makes it easier to
272 augment the default script.
274 * Linker script input section filespecs may now specify a file within an
275 archive by writing "archive:file".
277 * The --sort-common switch now has an optional argument which specifies the
278 direction of sorting.
280 * The M68K linker now supports multiple GOT generation schemes controlled via
281 the --got=<type> command line option.
283 * The ARM EABI linker will now generate stubs for function calls to symbols
284 that are too far away. The placement of the stubs is controlled by a new
285 linker command line option: --stub-group-size=N.
289 * Linker sources now released under version 3 of the GNU General Public
292 * ELF: New --build-id option to generate a unique per-binary identifier
293 embedded in a note section.
295 * Added support for National Semicondutor CompactRISC (ie CR16) target.
297 * -l:foo now searches the library path for a filename called foo,
298 without converting it to libfoo.a or libfoo.so.
300 * Add a new command line option '--default-script=FILE' or '-dT FILE'
301 which specifies a replacement for the built in, default linker
304 * ELF: Add -Bsymbolic-functions, --dynamic-list-cpp-new, which puts C++
305 operator new and delete on the dynamic list, and --dynamic-list-data,
306 builtin list for --dynamic-list, which puts global data symbols on the
309 * Add support for x86_64 PE+ target.
311 * Add support for Score target.
313 * ELF: Add --dynamic-list option to specify a list of global symbols
314 whose references shouldn't be bound to the definition within the
315 shared library, or a list of symbols which should be added to the
316 symbol table in the executable.
318 * The default output section LMA has changed for allocatable sections from
319 being equal to VMA, to keeping the difference between LMA and VMA the same as
320 the previous output section in the same region. This is a more useful
321 default when using overlays and other cases where you specify an LMA
322 differing from the VMA for some sections.
324 * New switch: --print-gc-sections to list any sections removed by garabge
327 * ARM: Added --vfp11-denorm-fix option to work around an erratum in current
332 * Support for the Infineon XC16X has been added by KPIT Cummins Infosystems.
334 * Modify the Linux linker search order to better match ld.so search order.
335 Look for DT_NEEDED libraries in paths specified by ld.so.conf before
336 searching the default directories, rather than vice versa.
337 Use $prefix/etc/ld.so.conf if it exists, otherwise /etc/ld.so.conf.
339 * PE-COFF: Forward exports from DLL's can now be specified in .def files
340 passed directly to ld.
342 * Support for the Z80 processor family has been added.
344 * Add support for the "@<file>" syntax to the command line, so that extra
345 switches can be read from <file>.
349 * Support for the R_ARM_V4BX relocation as defined in the ARM AAELF
350 specification has been added via the --fix-v4bx command-line option.
352 * New linker script construct AS_NEEDED(), which sets the --as-needed flag
353 for input files listed inside of it.
355 * A new command-line option, --sysroot, can be used to override the
356 default sysroot location. It only applies to toolchains that were
357 configured using --with-sysroot.
359 * New linker script functions: ORIGIN() and LENGTH() which return information
360 about a specified memory region.
362 * Port to MAXQ processor contributed by HCL Tech.
364 * Added SEGMENT_START to the linker script language to permit the user to
365 override the base address for a segment from the command-line.
367 * ELF: --warn-shared-textrel option to warn if adding a DT_TEXTREL to a shared
370 * Added SORT_BY_NAME and SORT_BY_ALIGNMENT to the linker script
371 language to permit sorting sections by section name or section
374 * Added a new linker command line switch, --sort-section name|alignment,
375 to sort sections by section name or maximum alignment.
377 * ELF: --add-needed/--no-add-needed options to control if a DT_NEEDED tag
378 should be added when a shared library comes from DT_NEEDED tags.
380 * Support for the crx-elf target added.
382 * Support for the sh-symbianelf target added.
384 * A new linker command line switch has been added which allows the hash table
385 size to be set to a suitable prime value near to its argument. This switch
386 is --hash-size=<NUMBER>. Also if the switch --reduce-memory-overheads is
387 used, and --hash-size has not been used, then the default value will be set
390 * Linker map files are now generated with an O(N) algorithm for finding symbols
391 that are defined in each section. This uses about 40% more memory for
392 symbols than the old O(N^2) algorithm. You can use the new
393 --reduce-memory-overheads option to select the old algorithm; this option
394 might also be used in the future to select similar tradeoffs.
398 * ELF: --as-needed/--no-as-needed options to control if a DT_NEEDED tag should
399 be added only when a shared library is referenced.
401 * PE: --large-address-aware option to indicate executables support virtual
402 addresses greater than 2 gigabytes.
404 * DWARF 2 support for i386pe added.
406 * The linker script operator DEFINED() will now yield 1 only for a symbol that
407 is defined before the statement where DEFINED is used.
409 * The MIPS --embedded-relocs (used to embed relocations into binaries for
410 Embedded-PIC code) is deprecated and will be removed in a future release.
412 * cr16c support added by NSC.
414 * m32r Linux (ELF) support added by Renesas.
416 * Improved linker's handling of unresolved symbols. The switch
417 --unresolved-symbols=<method> has been added to tell the linker when it
418 should report them and the switch --warn-unresolved-symbols has been added to
419 make reports be issued as warning messages rather than errors.
423 * Added support for Xtensa architecture.
425 * Added --with-sysroot configure switch to specify a target system root, for
426 linking against a target filesystem image.
428 * Added --accept-unknown-linker-format to restore old linker behaviour (pre
429 2.14) of silently accepting and linking in any files in an unknown binary
432 * Added --no-omagic to undo the effects of the -N option.
434 * Support for Texas Instruments TMS320C4x and TMS320C3x series of
435 DSP's contributed by Michael Hayes and Svein E. Seldal.
437 * Added --with-lib-path configure switch to specify default value for
440 * ARM port to QNX operating system added by Graeme Peterson.
442 * IP2K support added by Denis Chertykov.
446 * Support for the Fujitsu FRV architecture added by Red Hat. Models for FR400
449 Changes in version 2.13:
451 * DEC VAX ELF support, by Matt Thomas.
453 Changes in version 2.12:
455 * Support for Don Knuth's MMIX, by Hans-Peter Nilsson.
457 * Support for the OpenRISC 32-bit embedded processor by OpenCores.
459 * Support for -z nocopyreloc in the x86 ELF linker, which disables
460 production of copy relocs. Warning: using this option may result in
461 non-sharable applications.
463 * Support for -z combreloc in the ELF linker, which puts dynamic
464 relocations against the same symbol together, so that dynamic linker
465 can use an one-entry symbol lookup cache.
467 * Support for ELF SHF_MERGE section merging, by Jakub Jelinek.
469 Changes in version 2.11:
471 * Support for AMD x86-64 architecture, by Jan Hubicka, SuSE Labs.
473 * Support added for eliminating duplicate DWARF2 debug information by
474 having the compiler generate the information in sections called
475 .gnu.linkonce.wi.XXXX where XXXX is a checksum for the contents. The
476 linker then merges these sections together into the normal .debug_info
479 * The native ELF linker now searches the directories in DT_RUNPATH or
480 DT_RPATH of a shared library for shared libraries needed by it.
482 * TI C54x support, by Timothy Wall.
484 * Added command line switch --section-start to set the start address of any
487 * Added ability to emit full relocation information in linked executables,
488 enabled by --emit-relocs. Some post-linkage optimization tools need
489 this information in order to be able to correctly identify and perform
490 symbol relative addressing in the event of changes in section contents
491 (instructions being added or deleted, extending data sections, etc.)
493 * Support for i860, by Jason Eckhardt (preliminary, alpha quality).
495 * Support for CRIS (Axis Communications ETRAX series).
497 * Support for PDP-11 and 2.11BSD a.out format, by Lars Brinkhoff.
499 Changes in version 2.10:
501 * Added AT> to the linker script language to allow load-time allocation of
502 sections into regions.
504 * Added garbage collection of unused sections, enabled by --gc-sections.
505 It does require a bit of backend support; currently implemented are
506 arm-elf, avr-elf, d10v-elf, fr30-elf, i386-elf, m32r-elf, m68k-elf,
507 mcore-elf, mips-elf, mn10300-elf, ppc-elf, sh-elf, sparc-elf, and v850-elf.
508 Others will ignore the option.
510 * Added SORT to the linker script language to permit sorting sections by file
511 name or section name.
513 * Added EXTERN to the linker script language as an equivalent to the -u
516 * Added ASSERT to the linker script language.
518 * Added EXCLUDE_FILE to the linker script language for further control over
521 * Added -O option to optimize linker output (as of this writing, this only
522 affects ELF shared library generation).
524 * The -e option now accepts a number as well as a symbol name.
526 * Added --no-undefined option to disallow undefined symbols when creating a
529 * The linker now issues a warning, not an error, for an undefined symbol when
530 using -Bsymbolic; use the new --no-undefined option to get the old
533 * Added --demangle and --no-demangle options.
535 Changes in version 2.9:
537 * Added SQUAD to the linker script language.
539 * New option --no-warn-mismatch.
541 * The MEMORY command now parses the attributes to determine where sections that
542 are not placed in a specific memory region are placed.
544 Changes in version 2.8:
546 * Linker scripts may now contain shell wildcard characters for file and section
549 * The linker now supports symbol versions in ELF.
551 * The NOCROSSREFS command was added to the linker script language.
553 * The LOADADDR expression was added to the linker script language.
555 * MAX and MIN functions were added to the linker script language.
557 * The OVERLAY construct was added to the linker script language.
559 * New option --warn-section-align to warn when the address of an output section
560 changes due to alignment of an input section.
562 * New options --filter/-F and --auxiliary/-f.
564 Changes in version 2.7:
566 * New option --cref to print out a cross reference table.
568 * New option --wrap SYMBOL.
570 * New option --no-whole-archive, to turn off the effect of --whole-archive.
572 * Input sections assigned to the output section /DISCARD/ in the linker script
573 are not included in the output file.
575 * The SunOS and ELF linkers now merge stabs debugging information which uses
576 the N_BINCL and N_EINCL stab types. This reduces the amount of debugging
577 information generated.
579 Changes in version 2.6:
581 * When an ELF section name is representable as a C identifier (this is not true
582 of most ELF section names), the linker will automatically define symbols
583 __start_SECNAME and __stop_SECNAME, where SECNAME is the section name, at the
584 beginning and the end of the section. This is used by glibc.
586 Addendum: Current versions of the linker (at least for version 2.18 onwards
587 and possibly much earlier as well) place two restrictions on this feature: The
588 symbols are only implemented for orphaned sections, not for explicitly placed
589 sections and they are PROVIDEd rather than being defined.
591 * When an ELF section named .gnu.warning is encountered in an input file, the
592 contents of the section are displayed as an error message, and the section is
593 not copied into the output file. This is used by glibc.
595 * When an ELF section named .gnu.warning.SYMBOL is encountered in an input
596 file, and the symbol SYMBOL is referenced by some object file, the contents of
597 the section are displayed as an error message. The section is not copied into
598 the output file, unless doing a relocatable or shared link. This is used by
601 * New options -split-by-reloc and -split-by-file.
603 * The linker now supports linking PIC compiled code on SPARC SunOS. It can
604 also create SPARC SunOS shared libraries, and, like the native SunOS linker,
605 will do so whenever there is an undefined symbol in the link and neither the -e
606 nor the -r option was used.
608 * The -rpath option may be used on SunOS to set the list of directories to be
609 searched at run time. This overrides the default of building the list from the
612 * The COFF linker now combines debugging information for structs, unions, and
613 enums, so that even if the same type is defined in multiple input files it will
614 only be defined once in the output file. The --traditional-format switch will
615 prevent this optimization.
617 Changes in version 2.5:
619 * The linker now supports linking against SunOS shared libraries. It still can
620 not link SunOS PIC (Position Independent Code) files, so it can not be used to
621 generate shared libraries.
623 * The linker now supports linking against ELF shared libraries for the i386
624 (UnixWare) and SPARC (Solaris). It can also link ELF PIC files, and can be
625 used to generate shared libraries. Shared library generation is not well
626 tested; please report any problems encountered. The linker is now enabled for
629 * Eric Youngdale has contributed Linux support code, including linking against
630 Linux a.out shared libraries. The linker produces Linux QMAGIC binaries.
632 * The ELF backend has been converted to the new linker code. To use the new
633 ELF linker, each particular target requires a relocation function. So far,
634 this function has been written for i386 (UnixWare), SPARC (Solaris) MIPS (Irix
635 5), and HPPA ELF targets.
637 * The -( (--start-group) and -) (--end-group) options have been added to
638 support searching a group of archives as though they were a single archive.
639 This can also be used in a linker script, as GROUP ( files ).
641 * When a file is named on the command line, and the linker does not recognize
642 it as an object file, the linker will now treat the file as a linker script
643 file. A linker script named in this way augments, but does not replace, the
644 default linker script.
646 * The -warn-once option was added. It causes the linker to only warn once per
647 undefined symbol, rather than once per reference.
649 * The COFF backend has been converted to the new linker code. As with ELF, to
650 use the new linker, each particular target requires a relocation function. So
651 far, this function has been written for the i386, m68k, a29k and SH targets.
653 * The -V flag was made a synonym for -v, for SVR4 compatibility. The old -V
654 behaviour is available via --verbose.
656 Changes in version 2.4:
658 * New linker code, by Steve Chamberlain and Ian Taylor. For a.out and ecoff
659 formats (so far), this should result in considerable savings in time
660 and memory used while linking; slightly poorer performance than
661 before for formats not converted yet.
663 * Command-line parsing is no longer done with flex. This means
664 oddball characters in filenames won't get treated as argument
667 * HP-PA ELF support, by Jeff Law. (No SOM support yet.)
669 * Mach i386 support, by David Mackenzie.
671 * Irix 4 shared libraries are now supported (Irix 5 uses ELF, and ELF shared
672 libraries are not yet supported).
674 * COFF shared libraries (as on SCO) should work as well.
676 * The linker is disabled for Solaris. (Actually, it was in 2.3 also, I just
677 forgot to note it.) Some of their C library routines don't work when
678 statically linked, and the GNU linker doesn't support dynamic linking yet.
680 Changes in version 2.3:
682 * Weak symbols are now supported.
684 * ELF support has been added. The linker has been bootstrapped on
685 UnixWare and Solaris.
687 * Alpha OSF/1 support has been added (non dynamic linking only).
689 Changes in version 2.2:
691 * The `bfd' library has been updated to reduce a.out-format string
692 table size. The effect of this is that files linked from many input
693 files with duplicate symbols (`-g' debugging records, or identical
694 static symbols) should be much smaller.
696 Changes in version 2.1:
698 * The ld -ySYMBOL flag (to trace references to SYMBOL) is now implemented.
700 * There is now support for writing ECOFF files, so ld and the
701 other utilities should work on Risc/Ultrix and Irix.
704 Copyright (C) 2012-2017 Free Software Foundation, Inc.
706 Copying and distribution of this file, with or without modification,
707 are permitted in any medium without royalty provided the copyright
708 notice and this notice are preserved.