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1 -*- text -*-
2
3 Changes in 2.38:
4
5 * Add -z pack-relative-relocs/-z no pack-relative-relocs to x86 ELF
6 linker to pack relative relocations in the DT_RELR section.
7
8 * Add support for the LoongArch architecture.
9
10 * Add -z indirect-extern-access/-z noindirect-extern-access to x86 ELF
11 linker to control canonical function pointers and copy relocation.
12
13 * Add --max-cache-size=SIZE to set the the maximum cache size to SIZE
14 bytes.
15
16 Changes in 2.37:
17
18 * arm-symbianelf support removed.
19
20 * Add -z report-relative-reloc to x86 ELF linker to report dynamic
21 relative relocations.
22
23 * Add -z start-stop-gc to disable special treatment of __start_*/__stop_*
24 references when --gc-sections.
25
26 * Add -Bno-symbolic to cancel -Bsymbolic and -Bsymbolic-functions.
27
28 Changes in 2.36:
29
30 * Add libdep plugin, for linking dependencies of static libraries that
31 were recorded by ar in the __.LIBDEP archive member.
32
33 * Add --error-handling-script=<NAME> command line option to allow a helper
34 script to be invoked when an undefined symbol or a missing library is
35 encountered. This option can be suppressed via the configure time
36 switch: --enable-error-handling-script=no.
37
38 * Add -z lam-u48 to x86-64 ELF linker to generate LAM_U48 property.
39
40 * Add -z lam-u57 to x86-64 ELF linker to enerate LAM_U57 property.
41
42 * Add -z lam-u48-report=[none|warning|error] to report missing LAM_U48
43 property.
44
45 * Add -z lam-u57-report=[none|warning|error] to report missing LAM_U57
46 property.
47
48 * Add -z lam-report=[none|warning|error] to report missing LAM_U48 and
49 LAM_U57 properties.
50
51 * Add -z x86-64-{baseline|v[234]} to the x86 ELF linker to mark
52 x86-64-{baseline|v[234]} ISA level as needed.
53
54 * Add -z unique-symbol to avoid duplicated local symbol names.
55
56 * The creation of PE format DLLs now defaults to using a more secure set of DLL
57 characteristics.
58
59 * The linker now deduplicates the types in .ctf sections. The new
60 command-line option --ctf-share-types describes how to do this:
61 its default value, share-unconflicted, produces the most compact
62 output.
63
64 * The linker now omits the "variable section" from .ctf sections by
65 default, saving space. This is almost certainly what you want
66 unless you are working on a project that has its own analogue
67 of symbol tables that are not reflected in the ELF symtabs.
68
69 * Add support for the SHF_GNU_RETAIN ELF section flag.
70 This flag specifies that the section should not be garbage collected by the
71 linker.
72
73 Changes in 2.35:
74
75 * X86 NaCl target support is removed.
76
77 * Add ELF linker command-line options, --export-dynamic-symbol and
78 --export-dynamic-symbol-list, to make symbols dynamic.
79
80 * Add a configure option, --enable-textrel-check=[no|yes|warning|error],
81 to decide what ELF linker should do by default with DT_TEXTREL in an
82 executable or shared library. Default to yes for Linux/x86 targets.
83
84 * The -Map=<filename> command line option has been extended so that if
85 <filename> is a directory then <filename>/<output-filename>.map will be
86 created.
87
88 * Add a command-line option for ELF linker, --warn-textrel, to warn that
89 DT_TEXTREL is set in a position-independent executable or shared object.
90
91 * Add command-line options --enable-non-contiguous-regions and
92 --enable-non-contiguous-regions-warnings.
93
94 * Add command-line option --imagic for the pdp11-aout target to output format
95 IMAGIC (0411) for separate instruction and data spaces, and change the
96 default format option for pdp11-aout to be --omagic.
97
98 * Relative pathnames in INPUT() and GROUP() directives in linker scripts are
99 searched relative to the directory of the linker script before other search
100 paths.
101
102 * Add ELF linker command-line option `-z start-stop-visibility=...' to control
103 the visibility of synthetic `__start_SECNAME` and `__stop_SECNAME` symbols.
104
105 * Add command-line option --dependency-file to write a Make-style dependency
106 file listing the input files consulted by the linker, like the files written
107 by the compiler's -M -MP options.
108
109 Changes in 2.34:
110
111 * The ld check for "PHDR segment not covered by LOAD segment" is more
112 effective, catching cases that were wrongly allowed by previous versions of
113 ld. If you see this error it is likely you are linking with a bad linker
114 script or the binary you are building is not intended to be loaded by a
115 dynamic loader. In the latter case --no-dynamic-linker is appropriate.
116
117 * cr16c support removed.
118
119 * Add support for z80-elf.
120
121 * Add support for relocation of each byte or word of multibyte value to Z80
122 targets.
123
124 * Add support for Zilog eZ80 (both ADL and Z80 mode) and Zilog Z180 CPUs.
125
126 Changes in 2.33:
127
128 * Add command-line option --no-print-map-discarded.
129
130 * The Cortex-A53 Erratum 843419 workaround now supports a choice of which
131 workaround to use. The option --fix-cortex-a53-843419 now takes an
132 optional argument --fix-cortex-a53-843419[=full|adr|adrp] which can be
133 used to force a particular workaround to be used. See --help for AArch64
134 for more details.
135
136 * Add target handlers for AArch64 for ELF GNU program properties.
137
138 * Add support for GNU_PROPERTY_AARCH64_FEATURE_1_BTI in ELF GNU program
139 properties in the AArch64 ELF linker.
140
141 * Add support for GNU_PROPERTY_AARCH64_FEATURE_1_PAC in ELF GNU program
142 properties in the AArch64 ELF linker.
143
144 * Add -z force-bti for AArch64 to enable GNU_PROPERTY_AARCH64_FEATURE_1_BTI
145 on output while warning about missing GNU_PROPERTY_AARCH64_FEATURE_1_BTI
146 on inputs and use PLTs protected with BTI.
147
148 * Add -z pac-plt for AArch64 to pick PAC enabled PLTs.
149
150 Changes in 2.32:
151
152 * Report property change in linker map file when merging GNU properties.
153
154 * Add support for the C-SKY processor series.
155
156 * -t now doesn't report members within archives, unless -t is given twice.
157 A single -t is now more useful when generating a list of files that should be
158 packaged for a linker bug report. For example:
159 gcc hello.c -save-temps -Wl,-t | xargs realpath | sort | uniq > files
160 tar cJf test.tar.xz `cat files`
161
162 Changes in 2.31:
163
164 * Speed up direct linking with DLLs for Cygwin and Mingw targets.
165
166 * Add a configure option --enable-separate-code to decide whether
167 -z separate-code should be enabled in ELF linker by default. Default
168 to yes for Linux/x86 targets. Note that -z separate-code can increase
169 disk and memory size.
170
171 Changes in 2.30:
172
173 * Add -z separate-code to generate separate code PT_LOAD segment.
174
175 * Add "-z undefs" command-line option as the inverse of the "-z defs" option.
176
177 * Add -z globalaudit command-line option to force audit libraries to be run
178 for every dynamic object loaded by an executable - provided that the loader
179 supports this functionality.
180
181 * Tighten linker script grammar around file name specifiers to prevent the use
182 of SORT_BY_ALIGNMENT and SORT_BY_INIT_PRIORITY on filenames. These would
183 previously be accepted but had no effect.
184
185 * The EXCLUDE_FILE directive can now be placed within any SORT_* directive
186 within input section lists.
187
188 Changes in 2.29:
189
190 * Support for -z shstk in the x86 ELF linker to generate
191 GNU_PROPERTY_X86_FEATURE_1_SHSTK in ELF GNU program properties.
192
193 * Add support for GNU_PROPERTY_X86_FEATURE_1_SHSTK in ELF GNU program
194 properties in the x86 ELF linker.
195
196 * Add support for GNU_PROPERTY_X86_FEATURE_1_IBT in ELF GNU program
197 properties in the x86 ELF linker.
198
199 * Support for -z ibtplt in the x86 ELF linker to generate IBT-enabled
200 PLT.
201
202 * Support for -z ibt in the x86 ELF linker to generate IBT-enabled
203 PLT as well as GNU_PROPERTY_X86_FEATURE_1_IBT in ELF GNU program
204 properties.
205
206 * Add support for ELF SHF_GNU_MBIND and PT_GNU_MBIND_XXX.
207
208 * Add support for ELF GNU program properties.
209
210 * Add support for the Texas Instruments PRU processor.
211
212 * When configuring for arc*-*-linux* targets the default linker emulation will
213 change if --with-cpu=nps400 is used at configure time.
214
215 * Improve assignment of LMAs to orphan sections in some edge cases where a
216 mixture of both AT>LMA_REGION and AT(LMA) are used.
217
218 * Orphan sections placed after an empty section that has an AT(LMA) will now
219 take an load memory address starting from LMA.
220
221 * Section groups can now be resolved (the group deleted and the group members
222 placed like normal sections) at partial link time either using the new linker
223 option --force-group-allocation or by placing FORCE_GROUP_ALLOCATION into the
224 linker script.
225
226 Changes in 2.28:
227
228 * The EXCLUDE_FILE linker script construct can now be applied outside of the
229 section list in order for the exclusions to apply over all input sections in
230 the list.
231
232 * Add support for the RISC-V architecture.
233
234 * The command-line option --no-eh-frame-hdr can now be used in ELF based
235 linkers to disable the automatic generation of .eh_frame_hdr sections.
236
237 * Add --in-implib=<infile> to the ARM linker to enable specifying a set of
238 Secure Gateway veneers that must exist in the output import library specified
239 by --out-implib=<outfile> and the address they must have. As such,
240 --in-implib is only supported in combination with --cmse-implib.
241
242 * Extended the --out-implib=<file> option, previously restricted to x86 PE
243 targets, to any ELF based target. This allows the generation of an import
244 library for an ELF executable, which can then be used by another application
245 to link against the executable.
246
247 Changes in 2.27:
248
249 * Add a configure option --enable-relro to decide whether -z relro should
250 be enabled in ELF linker by default. Default to yes for all Linux
251 targets except FRV, HPPA, IA64 and MIPS. Note that -z relro can increase
252 disk and memory size.
253
254 * Support for -z noreloc-overflow in the x86-64 ELF linker to disable
255 relocation overflow check.
256
257 * Add -z common/-z nocommon options for ELF targets to control whether to
258 convert common symbols to the STT_COMMON type during a relocatable link.
259
260 * Support for -z nodynamic-undefined-weak in the x86 ELF linker, which
261 avoids dynamic relocations against undefined weak symbols in executable.
262
263 * The NOCROSSREFSTO command was added to the linker script language.
264
265 * Add --no-apply-dynamic-relocs to the AArch64 linker to do not apply link-time
266 values for dynamic relocations.
267
268 Changes in 2.26:
269
270 * Add --fix-stm32l4xx-629360 to the ARM linker to enable a link-time
271 workaround for a bug in the bus matrix / memory controller for some of
272 the STM32 Cortex-M4 based products (STM32L4xx)
273
274 * Add a configure option --enable-compressed-debug-sections={all,ld} to
275 decide whether DWARF debug sections should be compressed by default.
276
277 * Add support for the ARC EM/HS, and ARC600/700 architectures.
278
279 * Experimental support for linker garbage collection (--gc-sections)
280 has been enabled for COFF and PE based targets.
281
282 * New command-line option for ELF targets to compress DWARF debug
283 sections, --compress-debug-sections=[none|zlib|zlib-gnu|zlib-gabi].
284
285 * New command-line option, --orphan-handling=[place|warn|error|discard], to
286 adjust how orphan sections are handled. The default is 'place' which gives
287 the current behaviour, 'warn' and 'error' issue a warning or error
288 respectively when orphan sections are found, and 'discard' will discard all
289 orphan sections.
290
291 * Add support for LLVM plugin.
292
293 * Add --print-memory-usage option to report memory blocks usage.
294
295 * Add --require-defined option, it's like --undefined except the new symbol
296 must be defined by the end of the link.
297
298 Changes in 2.25:
299
300 * PE binaries now once again contain real timestamps by default. To disable
301 the inclusion of a timestamp in a PE binary, use the --no-insert-timestamp
302 command-line option.
303
304 * Replace support for openrisc and or32 with support for or1k.
305
306 * Add support for the --build-id command-line option to COFF based targets.
307
308 * x86/x86_64 pe-coff now supports the --build-id option.
309
310 * Add support for the Andes NDS32.
311
312 Changes in 2.24:
313
314 * Add LOG2CEIL() builtin function to the linker script language
315
316 * Add support for the Texas Instruments MSP430X processor.
317
318 * Add support for Altera Nios II.
319
320 * Add support for the V850E3V5 architecture.
321
322 * Add support for the Imagination Technologies Meta processor.
323
324 * --enable-new-dtags no longer generates old dtags in addition to new dtags.
325
326 * Remove linker support for MIPS ECOFF targets.
327
328 * Add ALIGN_WITH_INPUT to the linker script language to force the alignment of
329 an output section to use the maximum alignment of all its input sections.
330
331 Changes in 2.23:
332
333 * Enable compressed debug section feature for x86/x86_64 pe-coff.
334
335 * Add support for the 64-bit ARM architecture: AArch64.
336
337 * Added SORT_NONE to the linker script language to disable section sorting.
338
339 * Add a linker-provided symbol when producing ELF output, '__ehdr_start'
340 to point to the ELF file header (and nearby program headers) in the
341 program's memory image.
342
343 * Add support for S12X processor.
344
345 * Add support for the VLE extension to the PowerPC architecture.
346
347 * Add support for the Freescale XGATE architecture.
348
349 * Add option -f FILE on AIX (for response file).
350
351 * Add support for the Renesas RL78 architecture.
352
353 * Add support for the Adapteva EPIPHANY architecture.
354
355 Changes in 2.22:
356
357 * --copy-dt-needed-entries is no longer enabled by default. Instead
358 --no-copy-dt-needed-entries is the default.
359
360 * INPUT_SECTION_FLAGS has been added to the linker script language
361 to allow selection of input sections by section header section flags.
362
363 * Add support for the Tilera TILEPro and TILE-Gx architectures.
364
365 * Added SORT_BY_INIT_PRIORITY to the linker script language to permit
366 sorting sections by numerical value of the GCC init_priority attribute
367 encoded in the section name.
368
369 Changes in 2.21:
370
371 * Linker script expression evaluation is somewhat more sane. This may
372 break scripts that depend on quirks of the old expression evaluation.
373
374 * Turn off underscoring for x86_64 PE+-COFF targets. For old behavior the
375 option --enable-leading-mingw64-underscores can be used on configure of
376 bfd.
377
378 * Add support for the TMS320C6000 (TI C6X) processor family.
379
380 * --add-needed renamed to --copy-dt-needed-entries in order to avoid confusion
381 with --as-needed option.
382
383 * Extend .def file syntax by '== <ID>' for imports and exports. This allows
384 to alias the import/export table name written in PE image.
385
386 * Add --exclude-all-symbols option to PE based linkers. This prevents all
387 symbols from automatically being exported.
388
389 * Add support for the Renesas RX processor.
390
391 * Add support for alpha-vms target.
392
393 Changes in 2.20:
394
395 * GNU/Linux targets now support the STB_GNU_UNIQUE symbol binding. This is a
396 GNU extension to the standard set of ELF symbol bindings. The binding will
397 be passed on to the dynamic linker which will make sure that in the entire
398 process there is just one symbol with the given name and type in use.
399
400 * PE targets now support a GNU extension to allow the alignment of common
401 common symbols to be specified. This support uses custom options in
402 the .drectve section, which will be disregarded by the native tools.
403
404 * PE targets now add primitive support for ELF version scripts; symbols
405 are not versioned, but the local and global symbol visibility directives
406 are respected when filtering symbols in auto-export mode.
407
408 * New option --no-export-dynamic to undo the effect of the -E and
409 --export-dynamic options.
410
411 * ELF: --warn-alternate-em option to warn if an object has alternate
412 ELF machine code.
413
414 * New script function REGION_ALIAS to add alias names to memory regions.
415
416 * PE targets no longer make use of the long section names PE extension to
417 the COFF format when generating executable images, by default. The old
418 (slightly non-conformant) behaviour can still be invoked by using the
419 new '--enable-long-section-names' command-line option. It is also enabled
420 automatically in the presence of un-stripped debug information, as GDB
421 needs to be able to find the debug info sections by their full names.
422
423 * For GNU/Linux systems the linker will now avoid processing any relocations
424 made against symbols of the STT_GNU_IFUNC type and instead emit them into
425 the resulting binary for processing by the loader.
426
427 * --as-needed now links in a dynamic library if it satisfies undefined
428 symbols in regular objects, or in other dynamic libraries. In the
429 latter case the library is not linked if it is found in a DT_NEEDED
430 entry of one of the libraries already linked.
431
432 * Add a new command-line option, -Ttext-segment ADDR, for ELF targets
433 to set the address of the first byte of the text segment.
434
435 * Add support for Sunplus score architecture.
436
437 * Add new option --use-nul-prefixed-import-tables to ld for PE targets to
438 allow fallback to old import table generation with null element prefix.
439
440 * Windows PE systems now support a new --exclude-modules-for-implib option,
441 allowing users to partition object files and archive members between a DLL
442 and its associated import library as they are generated during linking.
443
444 * Add support for Lattice Mico32 (lm32) architecture.
445
446 * Add CR16 ELF --embedded-relocs (used to embedded relocations into binaries
447 for Embedded-PIC code) option.
448
449 * Add to the PE/PE+ targets the support of two different kinds of
450 pseudo-relocations. They can be selected by the switches
451 --enable-runtime-pseudo-reloc-v1 and --enable-runtime-pseudo-reloc-v2.
452 For the switch --enable-runtime-pseudo-reloc it uses for 32-bit
453 runtime pseudo relocation version one, for 64-bit the version two.
454
455 Changes in 2.19:
456
457 * Linker scripts support a new INSERT command that makes it easier to
458 augment the default script.
459
460 * Linker script input section filespecs may now specify a file within an
461 archive by writing "archive:file".
462
463 * The --sort-common switch now has an optional argument which specifies the
464 direction of sorting.
465
466 * The M68K linker now supports multiple GOT generation schemes controlled via
467 the --got=<type> command-line option.
468
469 * The ARM EABI linker will now generate stubs for function calls to symbols
470 that are too far away. The placement of the stubs is controlled by a new
471 linker command-line option: --stub-group-size=N.
472
473 Changes in 2.18:
474
475 * Linker sources now released under version 3 of the GNU General Public
476 License.
477
478 * ELF: New --build-id option to generate a unique per-binary identifier
479 embedded in a note section.
480
481 * Added support for National Semicondutor CompactRISC (ie CR16) target.
482
483 * -l:foo now searches the library path for a filename called foo,
484 without converting it to libfoo.a or libfoo.so.
485
486 * Add a new command-line option '--default-script=FILE' or '-dT FILE'
487 which specifies a replacement for the built in, default linker
488 script.
489
490 * ELF: Add -Bsymbolic-functions, --dynamic-list-cpp-new, which puts C++
491 operator new and delete on the dynamic list, and --dynamic-list-data,
492 builtin list for --dynamic-list, which puts global data symbols on the
493 dynamic list.
494
495 * Add support for x86_64 PE+ target.
496
497 * Add support for Score target.
498
499 * ELF: Add --dynamic-list option to specify a list of global symbols
500 whose references shouldn't be bound to the definition within the
501 shared library, or a list of symbols which should be added to the
502 symbol table in the executable.
503
504 * The default output section LMA has changed for allocatable sections from
505 being equal to VMA, to keeping the difference between LMA and VMA the same as
506 the previous output section in the same region. This is a more useful
507 default when using overlays and other cases where you specify an LMA
508 differing from the VMA for some sections.
509
510 * New switch: --print-gc-sections to list any sections removed by garabge
511 collection.
512
513 * ARM: Added --vfp11-denorm-fix option to work around an erratum in current
514 VFP11 coprocessors.
515
516 Changes in 2.17:
517
518 * Support for the Infineon XC16X has been added by KPIT Cummins Infosystems.
519
520 * Modify the Linux linker search order to better match ld.so search order.
521 Look for DT_NEEDED libraries in paths specified by ld.so.conf before
522 searching the default directories, rather than vice versa.
523 Use $prefix/etc/ld.so.conf if it exists, otherwise /etc/ld.so.conf.
524
525 * PE-COFF: Forward exports from DLL's can now be specified in .def files
526 passed directly to ld.
527
528 * Support for the Z80 processor family has been added.
529
530 * Add support for the "@<file>" syntax to the command line, so that extra
531 switches can be read from <file>.
532
533 Changes in 2.16:
534
535 * Support for the R_ARM_V4BX relocation as defined in the ARM AAELF
536 specification has been added via the --fix-v4bx command-line option.
537
538 * New linker script construct AS_NEEDED(), which sets the --as-needed flag
539 for input files listed inside of it.
540
541 * A new command-line option, --sysroot, can be used to override the
542 default sysroot location. It only applies to toolchains that were
543 configured using --with-sysroot.
544
545 * New linker script functions: ORIGIN() and LENGTH() which return information
546 about a specified memory region.
547
548 * Port to MAXQ processor contributed by HCL Tech.
549
550 * Added SEGMENT_START to the linker script language to permit the user to
551 override the base address for a segment from the command-line.
552
553 * ELF: --warn-shared-textrel option to warn if adding a DT_TEXTREL to a shared
554 object.
555
556 * Added SORT_BY_NAME and SORT_BY_ALIGNMENT to the linker script
557 language to permit sorting sections by section name or section
558 maximum alignment.
559
560 * Added a new linker command-line switch, --sort-section name|alignment,
561 to sort sections by section name or maximum alignment.
562
563 * ELF: --add-needed/--no-add-needed options to control if a DT_NEEDED tag
564 should be added when a shared library comes from DT_NEEDED tags.
565
566 * Support for the crx-elf target added.
567
568 * Support for the sh-symbianelf target added.
569
570 * A new linker command-line switch has been added which allows the hash table
571 size to be set to a suitable prime value near to its argument. This switch
572 is --hash-size=<NUMBER>. Also if the switch --reduce-memory-overheads is
573 used, and --hash-size has not been used, then the default value will be set
574 to 1021.
575
576 * Linker map files are now generated with an O(N) algorithm for finding symbols
577 that are defined in each section. This uses about 40% more memory for
578 symbols than the old O(N^2) algorithm. You can use the new
579 --reduce-memory-overheads option to select the old algorithm; this option
580 might also be used in the future to select similar tradeoffs.
581
582 Changes in 2.15:
583
584 * ELF: --as-needed/--no-as-needed options to control if a DT_NEEDED tag should
585 be added only when a shared library is referenced.
586
587 * PE: --large-address-aware option to indicate executables support virtual
588 addresses greater than 2 gigabytes.
589
590 * DWARF 2 support for i386pe added.
591
592 * The linker script operator DEFINED() will now yield 1 only for a symbol that
593 is defined before the statement where DEFINED is used.
594
595 * The MIPS --embedded-relocs (used to embed relocations into binaries for
596 Embedded-PIC code) is deprecated and will be removed in a future release.
597
598 * cr16c support added by NSC.
599
600 * m32r Linux (ELF) support added by Renesas.
601
602 * Improved linker's handling of unresolved symbols. The switch
603 --unresolved-symbols=<method> has been added to tell the linker when it
604 should report them and the switch --warn-unresolved-symbols has been added to
605 make reports be issued as warning messages rather than errors.
606
607 Changes in 2.14:
608
609 * Added support for Xtensa architecture.
610
611 * Added --with-sysroot configure switch to specify a target system root, for
612 linking against a target filesystem image.
613
614 * Added --accept-unknown-linker-format to restore old linker behaviour (pre
615 2.14) of silently accepting and linking in any files in an unknown binary
616 file format.
617
618 * Added --no-omagic to undo the effects of the -N option.
619
620 * Support for Texas Instruments TMS320C4x and TMS320C3x series of
621 DSP's contributed by Michael Hayes and Svein E. Seldal.
622
623 * Added --with-lib-path configure switch to specify default value for
624 LIB_PATH.
625
626 * ARM port to QNX operating system added by Graeme Peterson.
627
628 * IP2K support added by Denis Chertykov.
629
630 Changes in 2.13:
631
632 * Support for the Fujitsu FRV architecture added by Red Hat. Models for FR400
633 and FR500 included.
634
635 Changes in version 2.13:
636
637 * DEC VAX ELF support, by Matt Thomas.
638
639 Changes in version 2.12:
640
641 * Support for Don Knuth's MMIX, by Hans-Peter Nilsson.
642
643 * Support for the OpenRISC 32-bit embedded processor by OpenCores.
644
645 * Support for -z nocopyreloc in the x86 ELF linker, which disables
646 production of copy relocs. Warning: using this option may result in
647 non-sharable applications.
648
649 * Support for -z combreloc in the ELF linker, which puts dynamic
650 relocations against the same symbol together, so that dynamic linker
651 can use an one-entry symbol lookup cache.
652
653 * Support for ELF SHF_MERGE section merging, by Jakub Jelinek.
654
655 Changes in version 2.11:
656
657 * Support for AMD x86-64 architecture, by Jan Hubicka, SuSE Labs.
658
659 * Support added for eliminating duplicate DWARF2 debug information by
660 having the compiler generate the information in sections called
661 .gnu.linkonce.wi.XXXX where XXXX is a checksum for the contents. The
662 linker then merges these sections together into the normal .debug_info
663 section.
664
665 * The native ELF linker now searches the directories in DT_RUNPATH or
666 DT_RPATH of a shared library for shared libraries needed by it.
667
668 * TI C54x support, by Timothy Wall.
669
670 * Added command-line switch --section-start to set the start address of any
671 specified section.
672
673 * Added ability to emit full relocation information in linked executables,
674 enabled by --emit-relocs. Some post-linkage optimization tools need
675 this information in order to be able to correctly identify and perform
676 symbol relative addressing in the event of changes in section contents
677 (instructions being added or deleted, extending data sections, etc.)
678
679 * Support for i860, by Jason Eckhardt (preliminary, alpha quality).
680
681 * Support for CRIS (Axis Communications ETRAX series).
682
683 * Support for PDP-11 and 2.11BSD a.out format, by Lars Brinkhoff.
684
685 Changes in version 2.10:
686
687 * Added AT> to the linker script language to allow load-time allocation of
688 sections into regions.
689
690 * Added garbage collection of unused sections, enabled by --gc-sections.
691 It does require a bit of backend support; currently implemented are
692 arm-elf, avr-elf, d10v-elf, fr30-elf, i386-elf, m32r-elf, m68k-elf,
693 mcore-elf, mips-elf, mn10300-elf, ppc-elf, sh-elf, sparc-elf, and v850-elf.
694 Others will ignore the option.
695
696 * Added SORT to the linker script language to permit sorting sections by file
697 name or section name.
698
699 * Added EXTERN to the linker script language as an equivalent to the -u
700 command-line option.
701
702 * Added ASSERT to the linker script language.
703
704 * Added EXCLUDE_FILE to the linker script language for further control over
705 wildcard file names.
706
707 * Added -O option to optimize linker output (as of this writing, this only
708 affects ELF shared library generation).
709
710 * The -e option now accepts a number as well as a symbol name.
711
712 * Added --no-undefined option to disallow undefined symbols when creating a
713 shared library.
714
715 * The linker now issues a warning, not an error, for an undefined symbol when
716 using -Bsymbolic; use the new --no-undefined option to get the old
717 behaviour.
718
719 * Added --demangle and --no-demangle options.
720
721 Changes in version 2.9:
722
723 * Added SQUAD to the linker script language.
724
725 * New option --no-warn-mismatch.
726
727 * The MEMORY command now parses the attributes to determine where sections that
728 are not placed in a specific memory region are placed.
729
730 Changes in version 2.8:
731
732 * Linker scripts may now contain shell wildcard characters for file and section
733 names.
734
735 * The linker now supports symbol versions in ELF.
736
737 * The NOCROSSREFS command was added to the linker script language.
738
739 * The LOADADDR expression was added to the linker script language.
740
741 * MAX and MIN functions were added to the linker script language.
742
743 * The OVERLAY construct was added to the linker script language.
744
745 * New option --warn-section-align to warn when the address of an output section
746 changes due to alignment of an input section.
747
748 * New options --filter/-F and --auxiliary/-f.
749
750 Changes in version 2.7:
751
752 * New option --cref to print out a cross reference table.
753
754 * New option --wrap SYMBOL.
755
756 * New option --no-whole-archive, to turn off the effect of --whole-archive.
757
758 * Input sections assigned to the output section /DISCARD/ in the linker script
759 are not included in the output file.
760
761 * The SunOS and ELF linkers now merge stabs debugging information which uses
762 the N_BINCL and N_EINCL stab types. This reduces the amount of debugging
763 information generated.
764
765 Changes in version 2.6:
766
767 * When an ELF section name is representable as a C identifier (this is not true
768 of most ELF section names), the linker will automatically define symbols
769 __start_SECNAME and __stop_SECNAME, where SECNAME is the section name, at the
770 beginning and the end of the section. This is used by glibc.
771
772 Addendum: Current versions of the linker (at least for version 2.18 onwards
773 and possibly much earlier as well) place two restrictions on this feature: The
774 symbols are only implemented for orphaned sections, not for explicitly placed
775 sections and they are PROVIDEd rather than being defined.
776
777 * When an ELF section named .gnu.warning is encountered in an input file, the
778 contents of the section are displayed as an error message, and the section is
779 not copied into the output file. This is used by glibc.
780
781 * When an ELF section named .gnu.warning.SYMBOL is encountered in an input
782 file, and the symbol SYMBOL is referenced by some object file, the contents of
783 the section are displayed as an error message. The section is not copied into
784 the output file, unless doing a relocatable or shared link. This is used by
785 glibc.
786
787 * New options -split-by-reloc and -split-by-file.
788
789 * The linker now supports linking PIC compiled code on SPARC SunOS. It can
790 also create SPARC SunOS shared libraries, and, like the native SunOS linker,
791 will do so whenever there is an undefined symbol in the link and neither the -e
792 nor the -r option was used.
793
794 * The -rpath option may be used on SunOS to set the list of directories to be
795 searched at run time. This overrides the default of building the list from the
796 -L options.
797
798 * The COFF linker now combines debugging information for structs, unions, and
799 enums, so that even if the same type is defined in multiple input files it will
800 only be defined once in the output file. The --traditional-format switch will
801 prevent this optimization.
802
803 Changes in version 2.5:
804
805 * The linker now supports linking against SunOS shared libraries. It still can
806 not link SunOS PIC (Position Independent Code) files, so it can not be used to
807 generate shared libraries.
808
809 * The linker now supports linking against ELF shared libraries for the i386
810 (UnixWare) and SPARC (Solaris). It can also link ELF PIC files, and can be
811 used to generate shared libraries. Shared library generation is not well
812 tested; please report any problems encountered. The linker is now enabled for
813 Solaris again.
814
815 * Eric Youngdale has contributed Linux support code, including linking against
816 Linux a.out shared libraries. The linker produces Linux QMAGIC binaries.
817
818 * The ELF backend has been converted to the new linker code. To use the new
819 ELF linker, each particular target requires a relocation function. So far,
820 this function has been written for i386 (UnixWare), SPARC (Solaris) MIPS (Irix
821 5), and HPPA ELF targets.
822
823 * The -( (--start-group) and -) (--end-group) options have been added to
824 support searching a group of archives as though they were a single archive.
825 This can also be used in a linker script, as GROUP ( files ).
826
827 * When a file is named on the command line, and the linker does not recognize
828 it as an object file, the linker will now treat the file as a linker script
829 file. A linker script named in this way augments, but does not replace, the
830 default linker script.
831
832 * The -warn-once option was added. It causes the linker to only warn once per
833 undefined symbol, rather than once per reference.
834
835 * The COFF backend has been converted to the new linker code. As with ELF, to
836 use the new linker, each particular target requires a relocation function. So
837 far, this function has been written for the i386, m68k, a29k and SH targets.
838
839 * The -V flag was made a synonym for -v, for SVR4 compatibility. The old -V
840 behaviour is available via --verbose.
841
842 Changes in version 2.4:
843
844 * New linker code, by Steve Chamberlain and Ian Taylor. For a.out and ecoff
845 formats (so far), this should result in considerable savings in time
846 and memory used while linking; slightly poorer performance than
847 before for formats not converted yet.
848
849 * Command-line parsing is no longer done with flex. This means
850 oddball characters in filenames won't get treated as argument
851 separators.
852
853 * HP-PA ELF support, by Jeff Law. (No SOM support yet.)
854
855 * Mach i386 support, by David Mackenzie.
856
857 * Irix 4 shared libraries are now supported (Irix 5 uses ELF, and ELF shared
858 libraries are not yet supported).
859
860 * COFF shared libraries (as on SCO) should work as well.
861
862 * The linker is disabled for Solaris. (Actually, it was in 2.3 also, I just
863 forgot to note it.) Some of their C library routines don't work when
864 statically linked, and the GNU linker doesn't support dynamic linking yet.
865
866 Changes in version 2.3:
867
868 * Weak symbols are now supported.
869
870 * ELF support has been added. The linker has been bootstrapped on
871 UnixWare and Solaris.
872
873 * Alpha OSF/1 support has been added (non dynamic linking only).
874
875 Changes in version 2.2:
876
877 * The `bfd' library has been updated to reduce a.out-format string
878 table size. The effect of this is that files linked from many input
879 files with duplicate symbols (`-g' debugging records, or identical
880 static symbols) should be much smaller.
881
882 Changes in version 2.1:
883
884 * The ld -ySYMBOL flag (to trace references to SYMBOL) is now implemented.
885
886 * There is now support for writing ECOFF files, so ld and the
887 other utilities should work on Risc/Ultrix and Irix.
888
889 \f
890 Copyright (C) 2012-2022 Free Software Foundation, Inc.
891
892 Copying and distribution of this file, with or without modification,
893 are permitted in any medium without royalty provided the copyright
894 notice and this notice are preserved.
895
896 Local variables:
897 fill-column: 79
898 End: