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1 -*- text -*-
2
3 * Support Intel APX relocations.
4
5 * On RISC-V, add ld target option --[no-]check-uleb128. Should rebuild the
6 objects by binutils 2.42 and up if enabling the option and get warnings,
7 since the non-zero addend of SUB_ULEB128 shouldn't be generated from .uleb128
8 directives.
9
10 * Add support for the KVX instruction set.
11
12 * A new linker script sorting directive has been added: REVERSE. This reverses
13 the order of the sorting. It may be combined with either SORT_BY_NAME or
14 SORT_BY_INIT_PRIORITY.
15
16 * Added --warn-execstack-objects to warn about executable stacks only when an
17 input object file requests one. Also added --error-execstack and
18 --error-rxw-segments options to convert warnings about executable stacks and
19 segments into errors.
20
21 Also added --enable-error-execstack=[yes|no] and
22 --enable-error-rwx-segments=[yes|no] configure options to set the default for
23 converting warnings into errors.
24
25 Changes in 2.41:
26
27 * The linker now accepts a command line option of --remap-inputs
28 <PATTERN>=<FILE> to relace any input file that matches <PATTERN> with
29 <FILE>. In addition the option --remap-inputs-file=<FILE> can be used to
30 specify a file containing any number of these remapping directives.
31
32 * The linker command line option --print-map-locals can be used to include
33 local symbols in a linker map. (ELF targets only).
34
35 * For most ELF based targets, if the --enable-linker-version option is used
36 then the version of the linker will be inserted as a string into the .comment
37 section.
38
39 * The linker script syntax has a new command for output sections: ASCIZ "string"
40 This will insert a zero-terminated string at the current location.
41
42 * Add command-line option, -z nosectionheader, to omit ELF section
43 header.
44
45 Changes in 2.40:
46
47 * The linker has a new command line option to suppress the generation of any
48 warning or error messages. This can be useful when there is a need to create
49 a known non-working binary. The option is -w or --no-warnings.
50
51 * ld now supports zstd compressed debug sections. The new option
52 --compress-debug-sections=zstd compresses debug sections with zstd.
53
54 * Add --enable-default-compressed-debug-sections-algorithm={zlib,zstd}
55 that selects the default compression algorithm
56 for --enable-compressed-debug-sections.
57
58 * Remove support for -z bndplt (MPX prefix instructions).
59
60 Changes in 2.39:
61
62 * The ELF linker will now generate a warning message if the stack is made
63 executable. By default this warning is not issued if the user has
64 specifically requested an executable stack via the "-z execstack"
65 command line option, but the warning can be forced via the new
66 "--warn-execstack" option. Alternatively all warnings about creating
67 an executable stack can be suppressed via the "--no-warn-execstack"
68 option.
69
70 In addition the ELF linker will also warn if it creates a memory resident
71 segment with all three of the Read, Write and eXecute permissions set, or
72 if it creates a thread local data segment with the eXecute permission set.
73 These warnings can be disabled via --no-warn-rwx-segments option and
74 re-enabled via the --warn-rwx-segments option.
75
76 New configure options can also control these new features:
77
78 --enable-warn-execstack=no
79 will disable the warnings about creating an executable stack.
80
81 --enable-warn-execstack=yes
82 will make --warn-execstack enabled by default.
83
84 --enable-warn-rwx-segments=no
85 will make --no-warn-rwx-segments enabled by default.
86
87 --enable-default-execstack=no
88 will stop the creation of an executable stack simply because an input file
89 is missing a .note.GNU-stack section, even on architectures where this
90 behaviour is the default.
91
92 * TYPE=<type> is now supported in an output section description to set the
93 section type value.
94
95 * Remove (rudimentary) support for the x86-64 sub-architectures Intel L1OM and
96 Intel K1OM.
97
98 * The ELF linker now supports a new --package-metadata option that allows
99 embedding a JSON payload in accordance to the Package Metadata specification.
100 If support for libjansson is enabled at build time, the linker will use it to
101 validate the input. This can be enabled with --enable-jansson.
102 For more details, see: https://systemd.io/ELF_PACKAGE_METADATA/
103
104 Changes in 2.38:
105
106 * Add -z pack-relative-relocs/-z no pack-relative-relocs to x86 ELF
107 linker to pack relative relocations in the DT_RELR section.
108
109 * Add support for the LoongArch architecture.
110
111 * Add -z indirect-extern-access/-z noindirect-extern-access to x86 ELF
112 linker to control canonical function pointers and copy relocation.
113
114 * Add --max-cache-size=SIZE to set the the maximum cache size to SIZE
115 bytes.
116
117 Changes in 2.37:
118
119 * arm-symbianelf support removed.
120
121 * Add -z report-relative-reloc to x86 ELF linker to report dynamic
122 relative relocations.
123
124 * Add -z start-stop-gc to disable special treatment of __start_*/__stop_*
125 references when --gc-sections.
126
127 * Add -Bno-symbolic to cancel -Bsymbolic and -Bsymbolic-functions.
128
129 Changes in 2.36:
130
131 * Add libdep plugin, for linking dependencies of static libraries that
132 were recorded by ar in the __.LIBDEP archive member.
133
134 * Add --error-handling-script=<NAME> command line option to allow a helper
135 script to be invoked when an undefined symbol or a missing library is
136 encountered. This option can be suppressed via the configure time
137 switch: --enable-error-handling-script=no.
138
139 * Add -z lam-u48 to x86-64 ELF linker to generate LAM_U48 property.
140
141 * Add -z lam-u57 to x86-64 ELF linker to enerate LAM_U57 property.
142
143 * Add -z lam-u48-report=[none|warning|error] to report missing LAM_U48
144 property.
145
146 * Add -z lam-u57-report=[none|warning|error] to report missing LAM_U57
147 property.
148
149 * Add -z lam-report=[none|warning|error] to report missing LAM_U48 and
150 LAM_U57 properties.
151
152 * Add -z x86-64-{baseline|v[234]} to the x86 ELF linker to mark
153 x86-64-{baseline|v[234]} ISA level as needed.
154
155 * Add -z unique-symbol to avoid duplicated local symbol names.
156
157 * The creation of PE format DLLs now defaults to using a more secure set of DLL
158 characteristics.
159
160 * The linker now deduplicates the types in .ctf sections. The new
161 command-line option --ctf-share-types describes how to do this:
162 its default value, share-unconflicted, produces the most compact
163 output.
164
165 * The linker now omits the "variable section" from .ctf sections by
166 default, saving space. This is almost certainly what you want
167 unless you are working on a project that has its own analogue
168 of symbol tables that are not reflected in the ELF symtabs.
169
170 * Add support for the SHF_GNU_RETAIN ELF section flag.
171 This flag specifies that the section should not be garbage collected by the
172 linker.
173
174 Changes in 2.35:
175
176 * X86 NaCl target support is removed.
177
178 * Add ELF linker command-line options, --export-dynamic-symbol and
179 --export-dynamic-symbol-list, to make symbols dynamic.
180
181 * Add a configure option, --enable-textrel-check=[no|yes|warning|error],
182 to decide what ELF linker should do by default with DT_TEXTREL in an
183 executable or shared library. Default to yes for Linux/x86 targets.
184
185 * The -Map=<filename> command line option has been extended so that if
186 <filename> is a directory then <filename>/<output-filename>.map will be
187 created.
188
189 * Add a command-line option for ELF linker, --warn-textrel, to warn that
190 DT_TEXTREL is set in a position-independent executable or shared object.
191
192 * Add command-line options --enable-non-contiguous-regions and
193 --enable-non-contiguous-regions-warnings.
194
195 * Add command-line option --imagic for the pdp11-aout target to output format
196 IMAGIC (0411) for separate instruction and data spaces, and change the
197 default format option for pdp11-aout to be --omagic.
198
199 * Relative pathnames in INPUT() and GROUP() directives in linker scripts are
200 searched relative to the directory of the linker script before other search
201 paths.
202
203 * Add ELF linker command-line option `-z start-stop-visibility=...' to control
204 the visibility of synthetic `__start_SECNAME` and `__stop_SECNAME` symbols.
205
206 * Add command-line option --dependency-file to write a Make-style dependency
207 file listing the input files consulted by the linker, like the files written
208 by the compiler's -M -MP options.
209
210 Changes in 2.34:
211
212 * The ld check for "PHDR segment not covered by LOAD segment" is more
213 effective, catching cases that were wrongly allowed by previous versions of
214 ld. If you see this error it is likely you are linking with a bad linker
215 script or the binary you are building is not intended to be loaded by a
216 dynamic loader. In the latter case --no-dynamic-linker is appropriate.
217
218 * cr16c support removed.
219
220 * Add support for z80-elf.
221
222 * Add support for relocation of each byte or word of multibyte value to Z80
223 targets.
224
225 * Add support for Zilog eZ80 (both ADL and Z80 mode) and Zilog Z180 CPUs.
226
227 Changes in 2.33:
228
229 * Add command-line option --no-print-map-discarded.
230
231 * The Cortex-A53 Erratum 843419 workaround now supports a choice of which
232 workaround to use. The option --fix-cortex-a53-843419 now takes an
233 optional argument --fix-cortex-a53-843419[=full|adr|adrp] which can be
234 used to force a particular workaround to be used. See --help for AArch64
235 for more details.
236
237 * Add target handlers for AArch64 for ELF GNU program properties.
238
239 * Add support for GNU_PROPERTY_AARCH64_FEATURE_1_BTI in ELF GNU program
240 properties in the AArch64 ELF linker.
241
242 * Add support for GNU_PROPERTY_AARCH64_FEATURE_1_PAC in ELF GNU program
243 properties in the AArch64 ELF linker.
244
245 * Add -z force-bti for AArch64 to enable GNU_PROPERTY_AARCH64_FEATURE_1_BTI
246 on output while warning about missing GNU_PROPERTY_AARCH64_FEATURE_1_BTI
247 on inputs and use PLTs protected with BTI.
248
249 * Add -z pac-plt for AArch64 to pick PAC enabled PLTs.
250
251 Changes in 2.32:
252
253 * Report property change in linker map file when merging GNU properties.
254
255 * Add support for the C-SKY processor series.
256
257 * -t now doesn't report members within archives, unless -t is given twice.
258 A single -t is now more useful when generating a list of files that should be
259 packaged for a linker bug report. For example:
260 gcc hello.c -save-temps -Wl,-t | xargs realpath | sort | uniq > files
261 tar cJf test.tar.xz `cat files`
262
263 Changes in 2.31:
264
265 * Speed up direct linking with DLLs for Cygwin and Mingw targets.
266
267 * Add a configure option --enable-separate-code to decide whether
268 -z separate-code should be enabled in ELF linker by default. Default
269 to yes for Linux/x86 targets. Note that -z separate-code can increase
270 disk and memory size.
271
272 Changes in 2.30:
273
274 * Add -z separate-code to generate separate code PT_LOAD segment.
275
276 * Add "-z undefs" command-line option as the inverse of the "-z defs" option.
277
278 * Add -z globalaudit command-line option to force audit libraries to be run
279 for every dynamic object loaded by an executable - provided that the loader
280 supports this functionality.
281
282 * Tighten linker script grammar around file name specifiers to prevent the use
283 of SORT_BY_ALIGNMENT and SORT_BY_INIT_PRIORITY on filenames. These would
284 previously be accepted but had no effect.
285
286 * The EXCLUDE_FILE directive can now be placed within any SORT_* directive
287 within input section lists.
288
289 Changes in 2.29:
290
291 * Support for -z shstk in the x86 ELF linker to generate
292 GNU_PROPERTY_X86_FEATURE_1_SHSTK in ELF GNU program properties.
293
294 * Add support for GNU_PROPERTY_X86_FEATURE_1_SHSTK in ELF GNU program
295 properties in the x86 ELF linker.
296
297 * Add support for GNU_PROPERTY_X86_FEATURE_1_IBT in ELF GNU program
298 properties in the x86 ELF linker.
299
300 * Support for -z ibtplt in the x86 ELF linker to generate IBT-enabled
301 PLT.
302
303 * Support for -z ibt in the x86 ELF linker to generate IBT-enabled
304 PLT as well as GNU_PROPERTY_X86_FEATURE_1_IBT in ELF GNU program
305 properties.
306
307 * Add support for ELF SHF_GNU_MBIND and PT_GNU_MBIND_XXX.
308
309 * Add support for ELF GNU program properties.
310
311 * Add support for the Texas Instruments PRU processor.
312
313 * When configuring for arc*-*-linux* targets the default linker emulation will
314 change if --with-cpu=nps400 is used at configure time.
315
316 * Improve assignment of LMAs to orphan sections in some edge cases where a
317 mixture of both AT>LMA_REGION and AT(LMA) are used.
318
319 * Orphan sections placed after an empty section that has an AT(LMA) will now
320 take an load memory address starting from LMA.
321
322 * Section groups can now be resolved (the group deleted and the group members
323 placed like normal sections) at partial link time either using the new linker
324 option --force-group-allocation or by placing FORCE_GROUP_ALLOCATION into the
325 linker script.
326
327 Changes in 2.28:
328
329 * The EXCLUDE_FILE linker script construct can now be applied outside of the
330 section list in order for the exclusions to apply over all input sections in
331 the list.
332
333 * Add support for the RISC-V architecture.
334
335 * The command-line option --no-eh-frame-hdr can now be used in ELF based
336 linkers to disable the automatic generation of .eh_frame_hdr sections.
337
338 * Add --in-implib=<infile> to the ARM linker to enable specifying a set of
339 Secure Gateway veneers that must exist in the output import library specified
340 by --out-implib=<outfile> and the address they must have. As such,
341 --in-implib is only supported in combination with --cmse-implib.
342
343 * Extended the --out-implib=<file> option, previously restricted to x86 PE
344 targets, to any ELF based target. This allows the generation of an import
345 library for an ELF executable, which can then be used by another application
346 to link against the executable.
347
348 Changes in 2.27:
349
350 * Add a configure option --enable-relro to decide whether -z relro should
351 be enabled in ELF linker by default. Default to yes for all Linux
352 targets except FRV, HPPA, IA64 and MIPS. Note that -z relro can increase
353 disk and memory size.
354
355 * Support for -z noreloc-overflow in the x86-64 ELF linker to disable
356 relocation overflow check.
357
358 * Add -z common/-z nocommon options for ELF targets to control whether to
359 convert common symbols to the STT_COMMON type during a relocatable link.
360
361 * Support for -z nodynamic-undefined-weak in the x86 ELF linker, which
362 avoids dynamic relocations against undefined weak symbols in executable.
363
364 * The NOCROSSREFSTO command was added to the linker script language.
365
366 * Add --no-apply-dynamic-relocs to the AArch64 linker to do not apply link-time
367 values for dynamic relocations.
368
369 Changes in 2.26:
370
371 * Add --fix-stm32l4xx-629360 to the ARM linker to enable a link-time
372 workaround for a bug in the bus matrix / memory controller for some of
373 the STM32 Cortex-M4 based products (STM32L4xx)
374
375 * Add a configure option --enable-compressed-debug-sections={all,ld} to
376 decide whether DWARF debug sections should be compressed by default.
377
378 * Add support for the ARC EM/HS, and ARC600/700 architectures.
379
380 * Experimental support for linker garbage collection (--gc-sections)
381 has been enabled for COFF and PE based targets.
382
383 * New command-line option for ELF targets to compress DWARF debug
384 sections, --compress-debug-sections=[none|zlib|zlib-gnu|zlib-gabi].
385
386 * New command-line option, --orphan-handling=[place|warn|error|discard], to
387 adjust how orphan sections are handled. The default is 'place' which gives
388 the current behaviour, 'warn' and 'error' issue a warning or error
389 respectively when orphan sections are found, and 'discard' will discard all
390 orphan sections.
391
392 * Add support for LLVM plugin.
393
394 * Add --print-memory-usage option to report memory blocks usage.
395
396 * Add --require-defined option, it's like --undefined except the new symbol
397 must be defined by the end of the link.
398
399 Changes in 2.25:
400
401 * PE binaries now once again contain real timestamps by default. To disable
402 the inclusion of a timestamp in a PE binary, use the --no-insert-timestamp
403 command-line option.
404
405 * Replace support for openrisc and or32 with support for or1k.
406
407 * Add support for the --build-id command-line option to COFF based targets.
408
409 * x86/x86_64 pe-coff now supports the --build-id option.
410
411 * Add support for the Andes NDS32.
412
413 Changes in 2.24:
414
415 * Add LOG2CEIL() builtin function to the linker script language
416
417 * Add support for the Texas Instruments MSP430X processor.
418
419 * Add support for Altera Nios II.
420
421 * Add support for the V850E3V5 architecture.
422
423 * Add support for the Imagination Technologies Meta processor.
424
425 * --enable-new-dtags no longer generates old dtags in addition to new dtags.
426
427 * Remove linker support for MIPS ECOFF targets.
428
429 * Add ALIGN_WITH_INPUT to the linker script language to force the alignment of
430 an output section to use the maximum alignment of all its input sections.
431
432 Changes in 2.23:
433
434 * Enable compressed debug section feature for x86/x86_64 pe-coff.
435
436 * Add support for the 64-bit ARM architecture: AArch64.
437
438 * Added SORT_NONE to the linker script language to disable section sorting.
439
440 * Add a linker-provided symbol when producing ELF output, '__ehdr_start'
441 to point to the ELF file header (and nearby program headers) in the
442 program's memory image.
443
444 * Add support for S12X processor.
445
446 * Add support for the VLE extension to the PowerPC architecture.
447
448 * Add support for the Freescale XGATE architecture.
449
450 * Add option -f FILE on AIX (for response file).
451
452 * Add support for the Renesas RL78 architecture.
453
454 * Add support for the Adapteva EPIPHANY architecture.
455
456 Changes in 2.22:
457
458 * --copy-dt-needed-entries is no longer enabled by default. Instead
459 --no-copy-dt-needed-entries is the default.
460
461 * INPUT_SECTION_FLAGS has been added to the linker script language
462 to allow selection of input sections by section header section flags.
463
464 * Add support for the Tilera TILEPro and TILE-Gx architectures.
465
466 * Added SORT_BY_INIT_PRIORITY to the linker script language to permit
467 sorting sections by numerical value of the GCC init_priority attribute
468 encoded in the section name.
469
470 Changes in 2.21:
471
472 * Linker script expression evaluation is somewhat more sane. This may
473 break scripts that depend on quirks of the old expression evaluation.
474
475 * Turn off underscoring for x86_64 PE+-COFF targets. For old behavior the
476 option --enable-leading-mingw64-underscores can be used on configure of
477 bfd.
478
479 * Add support for the TMS320C6000 (TI C6X) processor family.
480
481 * --add-needed renamed to --copy-dt-needed-entries in order to avoid confusion
482 with --as-needed option.
483
484 * Extend .def file syntax by '== <ID>' for imports and exports. This allows
485 to alias the import/export table name written in PE image.
486
487 * Add --exclude-all-symbols option to PE based linkers. This prevents all
488 symbols from automatically being exported.
489
490 * Add support for the Renesas RX processor.
491
492 * Add support for alpha-vms target.
493
494 Changes in 2.20:
495
496 * GNU/Linux targets now support the STB_GNU_UNIQUE symbol binding. This is a
497 GNU extension to the standard set of ELF symbol bindings. The binding will
498 be passed on to the dynamic linker which will make sure that in the entire
499 process there is just one symbol with the given name and type in use.
500
501 * PE targets now support a GNU extension to allow the alignment of common
502 common symbols to be specified. This support uses custom options in
503 the .drectve section, which will be disregarded by the native tools.
504
505 * PE targets now add primitive support for ELF version scripts; symbols
506 are not versioned, but the local and global symbol visibility directives
507 are respected when filtering symbols in auto-export mode.
508
509 * New option --no-export-dynamic to undo the effect of the -E and
510 --export-dynamic options.
511
512 * ELF: --warn-alternate-em option to warn if an object has alternate
513 ELF machine code.
514
515 * New script function REGION_ALIAS to add alias names to memory regions.
516
517 * PE targets no longer make use of the long section names PE extension to
518 the COFF format when generating executable images, by default. The old
519 (slightly non-conformant) behaviour can still be invoked by using the
520 new '--enable-long-section-names' command-line option. It is also enabled
521 automatically in the presence of un-stripped debug information, as GDB
522 needs to be able to find the debug info sections by their full names.
523
524 * For GNU/Linux systems the linker will now avoid processing any relocations
525 made against symbols of the STT_GNU_IFUNC type and instead emit them into
526 the resulting binary for processing by the loader.
527
528 * --as-needed now links in a dynamic library if it satisfies undefined
529 symbols in regular objects, or in other dynamic libraries. In the
530 latter case the library is not linked if it is found in a DT_NEEDED
531 entry of one of the libraries already linked.
532
533 * Add a new command-line option, -Ttext-segment ADDR, for ELF targets
534 to set the address of the first byte of the text segment.
535
536 * Add support for Sunplus score architecture.
537
538 * Add new option --use-nul-prefixed-import-tables to ld for PE targets to
539 allow fallback to old import table generation with null element prefix.
540
541 * Windows PE systems now support a new --exclude-modules-for-implib option,
542 allowing users to partition object files and archive members between a DLL
543 and its associated import library as they are generated during linking.
544
545 * Add support for Lattice Mico32 (lm32) architecture.
546
547 * Add CR16 ELF --embedded-relocs (used to embedded relocations into binaries
548 for Embedded-PIC code) option.
549
550 * Add to the PE/PE+ targets the support of two different kinds of
551 pseudo-relocations. They can be selected by the switches
552 --enable-runtime-pseudo-reloc-v1 and --enable-runtime-pseudo-reloc-v2.
553 For the switch --enable-runtime-pseudo-reloc it uses for 32-bit
554 runtime pseudo relocation version one, for 64-bit the version two.
555
556 Changes in 2.19:
557
558 * Linker scripts support a new INSERT command that makes it easier to
559 augment the default script.
560
561 * Linker script input section filespecs may now specify a file within an
562 archive by writing "archive:file".
563
564 * The --sort-common switch now has an optional argument which specifies the
565 direction of sorting.
566
567 * The M68K linker now supports multiple GOT generation schemes controlled via
568 the --got=<type> command-line option.
569
570 * The ARM EABI linker will now generate stubs for function calls to symbols
571 that are too far away. The placement of the stubs is controlled by a new
572 linker command-line option: --stub-group-size=N.
573
574 Changes in 2.18:
575
576 * Linker sources now released under version 3 of the GNU General Public
577 License.
578
579 * ELF: New --build-id option to generate a unique per-binary identifier
580 embedded in a note section.
581
582 * Added support for National Semicondutor CompactRISC (ie CR16) target.
583
584 * -l:foo now searches the library path for a filename called foo,
585 without converting it to libfoo.a or libfoo.so.
586
587 * Add a new command-line option '--default-script=FILE' or '-dT FILE'
588 which specifies a replacement for the built in, default linker
589 script.
590
591 * ELF: Add -Bsymbolic-functions, --dynamic-list-cpp-new, which puts C++
592 operator new and delete on the dynamic list, and --dynamic-list-data,
593 builtin list for --dynamic-list, which puts global data symbols on the
594 dynamic list.
595
596 * Add support for x86_64 PE+ target.
597
598 * Add support for Score target.
599
600 * ELF: Add --dynamic-list option to specify a list of global symbols
601 whose references shouldn't be bound to the definition within the
602 shared library, or a list of symbols which should be added to the
603 symbol table in the executable.
604
605 * The default output section LMA has changed for allocatable sections from
606 being equal to VMA, to keeping the difference between LMA and VMA the same as
607 the previous output section in the same region. This is a more useful
608 default when using overlays and other cases where you specify an LMA
609 differing from the VMA for some sections.
610
611 * New switch: --print-gc-sections to list any sections removed by garabge
612 collection.
613
614 * ARM: Added --vfp11-denorm-fix option to work around an erratum in current
615 VFP11 coprocessors.
616
617 Changes in 2.17:
618
619 * Support for the Infineon XC16X has been added by KPIT Cummins Infosystems.
620
621 * Modify the Linux linker search order to better match ld.so search order.
622 Look for DT_NEEDED libraries in paths specified by ld.so.conf before
623 searching the default directories, rather than vice versa.
624 Use $prefix/etc/ld.so.conf if it exists, otherwise /etc/ld.so.conf.
625
626 * PE-COFF: Forward exports from DLL's can now be specified in .def files
627 passed directly to ld.
628
629 * Support for the Z80 processor family has been added.
630
631 * Add support for the "@<file>" syntax to the command line, so that extra
632 switches can be read from <file>.
633
634 Changes in 2.16:
635
636 * Support for the R_ARM_V4BX relocation as defined in the ARM AAELF
637 specification has been added via the --fix-v4bx command-line option.
638
639 * New linker script construct AS_NEEDED(), which sets the --as-needed flag
640 for input files listed inside of it.
641
642 * A new command-line option, --sysroot, can be used to override the
643 default sysroot location. It only applies to toolchains that were
644 configured using --with-sysroot.
645
646 * New linker script functions: ORIGIN() and LENGTH() which return information
647 about a specified memory region.
648
649 * Port to MAXQ processor contributed by HCL Tech.
650
651 * Added SEGMENT_START to the linker script language to permit the user to
652 override the base address for a segment from the command-line.
653
654 * ELF: --warn-shared-textrel option to warn if adding a DT_TEXTREL to a shared
655 object.
656
657 * Added SORT_BY_NAME and SORT_BY_ALIGNMENT to the linker script
658 language to permit sorting sections by section name or section
659 maximum alignment.
660
661 * Added a new linker command-line switch, --sort-section name|alignment,
662 to sort sections by section name or maximum alignment.
663
664 * ELF: --add-needed/--no-add-needed options to control if a DT_NEEDED tag
665 should be added when a shared library comes from DT_NEEDED tags.
666
667 * Support for the crx-elf target added.
668
669 * Support for the sh-symbianelf target added.
670
671 * A new linker command-line switch has been added which allows the hash table
672 size to be set to a suitable prime value near to its argument. This switch
673 is --hash-size=<NUMBER>. Also if the switch --reduce-memory-overheads is
674 used, and --hash-size has not been used, then the default value will be set
675 to 1021.
676
677 * Linker map files are now generated with an O(N) algorithm for finding symbols
678 that are defined in each section. This uses about 40% more memory for
679 symbols than the old O(N^2) algorithm. You can use the new
680 --reduce-memory-overheads option to select the old algorithm; this option
681 might also be used in the future to select similar tradeoffs.
682
683 Changes in 2.15:
684
685 * ELF: --as-needed/--no-as-needed options to control if a DT_NEEDED tag should
686 be added only when a shared library is referenced.
687
688 * PE: --large-address-aware option to indicate executables support virtual
689 addresses greater than 2 gigabytes.
690
691 * DWARF 2 support for i386pe added.
692
693 * The linker script operator DEFINED() will now yield 1 only for a symbol that
694 is defined before the statement where DEFINED is used.
695
696 * The MIPS --embedded-relocs (used to embed relocations into binaries for
697 Embedded-PIC code) is deprecated and will be removed in a future release.
698
699 * cr16c support added by NSC.
700
701 * m32r Linux (ELF) support added by Renesas.
702
703 * Improved linker's handling of unresolved symbols. The switch
704 --unresolved-symbols=<method> has been added to tell the linker when it
705 should report them and the switch --warn-unresolved-symbols has been added to
706 make reports be issued as warning messages rather than errors.
707
708 Changes in 2.14:
709
710 * Added support for Xtensa architecture.
711
712 * Added --with-sysroot configure switch to specify a target system root, for
713 linking against a target filesystem image.
714
715 * Added --accept-unknown-linker-format to restore old linker behaviour (pre
716 2.14) of silently accepting and linking in any files in an unknown binary
717 file format.
718
719 * Added --no-omagic to undo the effects of the -N option.
720
721 * Support for Texas Instruments TMS320C4x and TMS320C3x series of
722 DSP's contributed by Michael Hayes and Svein E. Seldal.
723
724 * Added --with-lib-path configure switch to specify default value for
725 LIB_PATH.
726
727 * ARM port to QNX operating system added by Graeme Peterson.
728
729 * IP2K support added by Denis Chertykov.
730
731 Changes in 2.13:
732
733 * Support for the Fujitsu FRV architecture added by Red Hat. Models for FR400
734 and FR500 included.
735
736 Changes in version 2.13:
737
738 * DEC VAX ELF support, by Matt Thomas.
739
740 Changes in version 2.12:
741
742 * Support for Don Knuth's MMIX, by Hans-Peter Nilsson.
743
744 * Support for the OpenRISC 32-bit embedded processor by OpenCores.
745
746 * Support for -z nocopyreloc in the x86 ELF linker, which disables
747 production of copy relocs. Warning: using this option may result in
748 non-sharable applications.
749
750 * Support for -z combreloc in the ELF linker, which puts dynamic
751 relocations against the same symbol together, so that dynamic linker
752 can use an one-entry symbol lookup cache.
753
754 * Support for ELF SHF_MERGE section merging, by Jakub Jelinek.
755
756 Changes in version 2.11:
757
758 * Support for AMD x86-64 architecture, by Jan Hubicka, SuSE Labs.
759
760 * Support added for eliminating duplicate DWARF2 debug information by
761 having the compiler generate the information in sections called
762 .gnu.linkonce.wi.XXXX where XXXX is a checksum for the contents. The
763 linker then merges these sections together into the normal .debug_info
764 section.
765
766 * The native ELF linker now searches the directories in DT_RUNPATH or
767 DT_RPATH of a shared library for shared libraries needed by it.
768
769 * TI C54x support, by Timothy Wall.
770
771 * Added command-line switch --section-start to set the start address of any
772 specified section.
773
774 * Added ability to emit full relocation information in linked executables,
775 enabled by --emit-relocs. Some post-linkage optimization tools need
776 this information in order to be able to correctly identify and perform
777 symbol relative addressing in the event of changes in section contents
778 (instructions being added or deleted, extending data sections, etc.)
779
780 * Support for i860, by Jason Eckhardt (preliminary, alpha quality).
781
782 * Support for CRIS (Axis Communications ETRAX series).
783
784 * Support for PDP-11 and 2.11BSD a.out format, by Lars Brinkhoff.
785
786 Changes in version 2.10:
787
788 * Added AT> to the linker script language to allow load-time allocation of
789 sections into regions.
790
791 * Added garbage collection of unused sections, enabled by --gc-sections.
792 It does require a bit of backend support; currently implemented are
793 arm-elf, avr-elf, d10v-elf, fr30-elf, i386-elf, m32r-elf, m68k-elf,
794 mcore-elf, mips-elf, mn10300-elf, ppc-elf, sh-elf, sparc-elf, and v850-elf.
795 Others will ignore the option.
796
797 * Added SORT to the linker script language to permit sorting sections by file
798 name or section name.
799
800 * Added EXTERN to the linker script language as an equivalent to the -u
801 command-line option.
802
803 * Added ASSERT to the linker script language.
804
805 * Added EXCLUDE_FILE to the linker script language for further control over
806 wildcard file names.
807
808 * Added -O option to optimize linker output (as of this writing, this only
809 affects ELF shared library generation).
810
811 * The -e option now accepts a number as well as a symbol name.
812
813 * Added --no-undefined option to disallow undefined symbols when creating a
814 shared library.
815
816 * The linker now issues a warning, not an error, for an undefined symbol when
817 using -Bsymbolic; use the new --no-undefined option to get the old
818 behaviour.
819
820 * Added --demangle and --no-demangle options.
821
822 Changes in version 2.9:
823
824 * Added SQUAD to the linker script language.
825
826 * New option --no-warn-mismatch.
827
828 * The MEMORY command now parses the attributes to determine where sections that
829 are not placed in a specific memory region are placed.
830
831 Changes in version 2.8:
832
833 * Linker scripts may now contain shell wildcard characters for file and section
834 names.
835
836 * The linker now supports symbol versions in ELF.
837
838 * The NOCROSSREFS command was added to the linker script language.
839
840 * The LOADADDR expression was added to the linker script language.
841
842 * MAX and MIN functions were added to the linker script language.
843
844 * The OVERLAY construct was added to the linker script language.
845
846 * New option --warn-section-align to warn when the address of an output section
847 changes due to alignment of an input section.
848
849 * New options --filter/-F and --auxiliary/-f.
850
851 Changes in version 2.7:
852
853 * New option --cref to print out a cross reference table.
854
855 * New option --wrap SYMBOL.
856
857 * New option --no-whole-archive, to turn off the effect of --whole-archive.
858
859 * Input sections assigned to the output section /DISCARD/ in the linker script
860 are not included in the output file.
861
862 * The SunOS and ELF linkers now merge stabs debugging information which uses
863 the N_BINCL and N_EINCL stab types. This reduces the amount of debugging
864 information generated.
865
866 Changes in version 2.6:
867
868 * When an ELF section name is representable as a C identifier (this is not true
869 of most ELF section names), the linker will automatically define symbols
870 __start_SECNAME and __stop_SECNAME, where SECNAME is the section name, at the
871 beginning and the end of the section. This is used by glibc.
872
873 Addendum: Current versions of the linker (at least for version 2.18 onwards
874 and possibly much earlier as well) place two restrictions on this feature: The
875 symbols are only implemented for orphaned sections, not for explicitly placed
876 sections and they are PROVIDEd rather than being defined.
877
878 * When an ELF section named .gnu.warning is encountered in an input file, the
879 contents of the section are displayed as an error message, and the section is
880 not copied into the output file. This is used by glibc.
881
882 * When an ELF section named .gnu.warning.SYMBOL is encountered in an input
883 file, and the symbol SYMBOL is referenced by some object file, the contents of
884 the section are displayed as an error message. The section is not copied into
885 the output file, unless doing a relocatable or shared link. This is used by
886 glibc.
887
888 * New options -split-by-reloc and -split-by-file.
889
890 * The linker now supports linking PIC compiled code on SPARC SunOS. It can
891 also create SPARC SunOS shared libraries, and, like the native SunOS linker,
892 will do so whenever there is an undefined symbol in the link and neither the -e
893 nor the -r option was used.
894
895 * The -rpath option may be used on SunOS to set the list of directories to be
896 searched at run time. This overrides the default of building the list from the
897 -L options.
898
899 * The COFF linker now combines debugging information for structs, unions, and
900 enums, so that even if the same type is defined in multiple input files it will
901 only be defined once in the output file. The --traditional-format switch will
902 prevent this optimization.
903
904 Changes in version 2.5:
905
906 * The linker now supports linking against SunOS shared libraries. It still can
907 not link SunOS PIC (Position Independent Code) files, so it can not be used to
908 generate shared libraries.
909
910 * The linker now supports linking against ELF shared libraries for the i386
911 (UnixWare) and SPARC (Solaris). It can also link ELF PIC files, and can be
912 used to generate shared libraries. Shared library generation is not well
913 tested; please report any problems encountered. The linker is now enabled for
914 Solaris again.
915
916 * Eric Youngdale has contributed Linux support code, including linking against
917 Linux a.out shared libraries. The linker produces Linux QMAGIC binaries.
918
919 * The ELF backend has been converted to the new linker code. To use the new
920 ELF linker, each particular target requires a relocation function. So far,
921 this function has been written for i386 (UnixWare), SPARC (Solaris) MIPS (Irix
922 5), and HPPA ELF targets.
923
924 * The -( (--start-group) and -) (--end-group) options have been added to
925 support searching a group of archives as though they were a single archive.
926 This can also be used in a linker script, as GROUP ( files ).
927
928 * When a file is named on the command line, and the linker does not recognize
929 it as an object file, the linker will now treat the file as a linker script
930 file. A linker script named in this way augments, but does not replace, the
931 default linker script.
932
933 * The -warn-once option was added. It causes the linker to only warn once per
934 undefined symbol, rather than once per reference.
935
936 * The COFF backend has been converted to the new linker code. As with ELF, to
937 use the new linker, each particular target requires a relocation function. So
938 far, this function has been written for the i386, m68k, a29k and SH targets.
939
940 * The -V flag was made a synonym for -v, for SVR4 compatibility. The old -V
941 behaviour is available via --verbose.
942
943 Changes in version 2.4:
944
945 * New linker code, by Steve Chamberlain and Ian Taylor. For a.out and ecoff
946 formats (so far), this should result in considerable savings in time
947 and memory used while linking; slightly poorer performance than
948 before for formats not converted yet.
949
950 * Command-line parsing is no longer done with flex. This means
951 oddball characters in filenames won't get treated as argument
952 separators.
953
954 * HP-PA ELF support, by Jeff Law. (No SOM support yet.)
955
956 * Mach i386 support, by David Mackenzie.
957
958 * Irix 4 shared libraries are now supported (Irix 5 uses ELF, and ELF shared
959 libraries are not yet supported).
960
961 * COFF shared libraries (as on SCO) should work as well.
962
963 * The linker is disabled for Solaris. (Actually, it was in 2.3 also, I just
964 forgot to note it.) Some of their C library routines don't work when
965 statically linked, and the GNU linker doesn't support dynamic linking yet.
966
967 Changes in version 2.3:
968
969 * Weak symbols are now supported.
970
971 * ELF support has been added. The linker has been bootstrapped on
972 UnixWare and Solaris.
973
974 * Alpha OSF/1 support has been added (non dynamic linking only).
975
976 Changes in version 2.2:
977
978 * The `bfd' library has been updated to reduce a.out-format string
979 table size. The effect of this is that files linked from many input
980 files with duplicate symbols (`-g' debugging records, or identical
981 static symbols) should be much smaller.
982
983 Changes in version 2.1:
984
985 * The ld -ySYMBOL flag (to trace references to SYMBOL) is now implemented.
986
987 * There is now support for writing ECOFF files, so ld and the
988 other utilities should work on Risc/Ultrix and Irix.
989
990 \f
991 Copyright (C) 2012-2024 Free Software Foundation, Inc.
992
993 Copying and distribution of this file, with or without modification,
994 are permitted in any medium without royalty provided the copyright
995 notice and this notice are preserved.
996
997 Local variables:
998 fill-column: 79
999 End: