gdb: Add maint set ignore-prologue-end-flag
[binutils-gdb.git] / ld / NEWS
1 -*- text -*-
2
3 * TYPE=<type> is now supported in an output section description to set the
4 section type value.
5
6 * Remove (rudimentary) support for the x86-64 sub-architectures Intel L1OM and
7 Intel K1OM.
8
9 Changes in 2.38:
10
11 * Add -z pack-relative-relocs/-z no pack-relative-relocs to x86 ELF
12 linker to pack relative relocations in the DT_RELR section.
13
14 * Add support for the LoongArch architecture.
15
16 * Add -z indirect-extern-access/-z noindirect-extern-access to x86 ELF
17 linker to control canonical function pointers and copy relocation.
18
19 * Add --max-cache-size=SIZE to set the the maximum cache size to SIZE
20 bytes.
21
22 Changes in 2.37:
23
24 * arm-symbianelf support removed.
25
26 * Add -z report-relative-reloc to x86 ELF linker to report dynamic
27 relative relocations.
28
29 * Add -z start-stop-gc to disable special treatment of __start_*/__stop_*
30 references when --gc-sections.
31
32 * Add -Bno-symbolic to cancel -Bsymbolic and -Bsymbolic-functions.
33
34 Changes in 2.36:
35
36 * Add libdep plugin, for linking dependencies of static libraries that
37 were recorded by ar in the __.LIBDEP archive member.
38
39 * Add --error-handling-script=<NAME> command line option to allow a helper
40 script to be invoked when an undefined symbol or a missing library is
41 encountered. This option can be suppressed via the configure time
42 switch: --enable-error-handling-script=no.
43
44 * Add -z lam-u48 to x86-64 ELF linker to generate LAM_U48 property.
45
46 * Add -z lam-u57 to x86-64 ELF linker to enerate LAM_U57 property.
47
48 * Add -z lam-u48-report=[none|warning|error] to report missing LAM_U48
49 property.
50
51 * Add -z lam-u57-report=[none|warning|error] to report missing LAM_U57
52 property.
53
54 * Add -z lam-report=[none|warning|error] to report missing LAM_U48 and
55 LAM_U57 properties.
56
57 * Add -z x86-64-{baseline|v[234]} to the x86 ELF linker to mark
58 x86-64-{baseline|v[234]} ISA level as needed.
59
60 * Add -z unique-symbol to avoid duplicated local symbol names.
61
62 * The creation of PE format DLLs now defaults to using a more secure set of DLL
63 characteristics.
64
65 * The linker now deduplicates the types in .ctf sections. The new
66 command-line option --ctf-share-types describes how to do this:
67 its default value, share-unconflicted, produces the most compact
68 output.
69
70 * The linker now omits the "variable section" from .ctf sections by
71 default, saving space. This is almost certainly what you want
72 unless you are working on a project that has its own analogue
73 of symbol tables that are not reflected in the ELF symtabs.
74
75 * Add support for the SHF_GNU_RETAIN ELF section flag.
76 This flag specifies that the section should not be garbage collected by the
77 linker.
78
79 Changes in 2.35:
80
81 * X86 NaCl target support is removed.
82
83 * Add ELF linker command-line options, --export-dynamic-symbol and
84 --export-dynamic-symbol-list, to make symbols dynamic.
85
86 * Add a configure option, --enable-textrel-check=[no|yes|warning|error],
87 to decide what ELF linker should do by default with DT_TEXTREL in an
88 executable or shared library. Default to yes for Linux/x86 targets.
89
90 * The -Map=<filename> command line option has been extended so that if
91 <filename> is a directory then <filename>/<output-filename>.map will be
92 created.
93
94 * Add a command-line option for ELF linker, --warn-textrel, to warn that
95 DT_TEXTREL is set in a position-independent executable or shared object.
96
97 * Add command-line options --enable-non-contiguous-regions and
98 --enable-non-contiguous-regions-warnings.
99
100 * Add command-line option --imagic for the pdp11-aout target to output format
101 IMAGIC (0411) for separate instruction and data spaces, and change the
102 default format option for pdp11-aout to be --omagic.
103
104 * Relative pathnames in INPUT() and GROUP() directives in linker scripts are
105 searched relative to the directory of the linker script before other search
106 paths.
107
108 * Add ELF linker command-line option `-z start-stop-visibility=...' to control
109 the visibility of synthetic `__start_SECNAME` and `__stop_SECNAME` symbols.
110
111 * Add command-line option --dependency-file to write a Make-style dependency
112 file listing the input files consulted by the linker, like the files written
113 by the compiler's -M -MP options.
114
115 Changes in 2.34:
116
117 * The ld check for "PHDR segment not covered by LOAD segment" is more
118 effective, catching cases that were wrongly allowed by previous versions of
119 ld. If you see this error it is likely you are linking with a bad linker
120 script or the binary you are building is not intended to be loaded by a
121 dynamic loader. In the latter case --no-dynamic-linker is appropriate.
122
123 * cr16c support removed.
124
125 * Add support for z80-elf.
126
127 * Add support for relocation of each byte or word of multibyte value to Z80
128 targets.
129
130 * Add support for Zilog eZ80 (both ADL and Z80 mode) and Zilog Z180 CPUs.
131
132 Changes in 2.33:
133
134 * Add command-line option --no-print-map-discarded.
135
136 * The Cortex-A53 Erratum 843419 workaround now supports a choice of which
137 workaround to use. The option --fix-cortex-a53-843419 now takes an
138 optional argument --fix-cortex-a53-843419[=full|adr|adrp] which can be
139 used to force a particular workaround to be used. See --help for AArch64
140 for more details.
141
142 * Add target handlers for AArch64 for ELF GNU program properties.
143
144 * Add support for GNU_PROPERTY_AARCH64_FEATURE_1_BTI in ELF GNU program
145 properties in the AArch64 ELF linker.
146
147 * Add support for GNU_PROPERTY_AARCH64_FEATURE_1_PAC in ELF GNU program
148 properties in the AArch64 ELF linker.
149
150 * Add -z force-bti for AArch64 to enable GNU_PROPERTY_AARCH64_FEATURE_1_BTI
151 on output while warning about missing GNU_PROPERTY_AARCH64_FEATURE_1_BTI
152 on inputs and use PLTs protected with BTI.
153
154 * Add -z pac-plt for AArch64 to pick PAC enabled PLTs.
155
156 Changes in 2.32:
157
158 * Report property change in linker map file when merging GNU properties.
159
160 * Add support for the C-SKY processor series.
161
162 * -t now doesn't report members within archives, unless -t is given twice.
163 A single -t is now more useful when generating a list of files that should be
164 packaged for a linker bug report. For example:
165 gcc hello.c -save-temps -Wl,-t | xargs realpath | sort | uniq > files
166 tar cJf test.tar.xz `cat files`
167
168 Changes in 2.31:
169
170 * Speed up direct linking with DLLs for Cygwin and Mingw targets.
171
172 * Add a configure option --enable-separate-code to decide whether
173 -z separate-code should be enabled in ELF linker by default. Default
174 to yes for Linux/x86 targets. Note that -z separate-code can increase
175 disk and memory size.
176
177 Changes in 2.30:
178
179 * Add -z separate-code to generate separate code PT_LOAD segment.
180
181 * Add "-z undefs" command-line option as the inverse of the "-z defs" option.
182
183 * Add -z globalaudit command-line option to force audit libraries to be run
184 for every dynamic object loaded by an executable - provided that the loader
185 supports this functionality.
186
187 * Tighten linker script grammar around file name specifiers to prevent the use
188 of SORT_BY_ALIGNMENT and SORT_BY_INIT_PRIORITY on filenames. These would
189 previously be accepted but had no effect.
190
191 * The EXCLUDE_FILE directive can now be placed within any SORT_* directive
192 within input section lists.
193
194 Changes in 2.29:
195
196 * Support for -z shstk in the x86 ELF linker to generate
197 GNU_PROPERTY_X86_FEATURE_1_SHSTK in ELF GNU program properties.
198
199 * Add support for GNU_PROPERTY_X86_FEATURE_1_SHSTK in ELF GNU program
200 properties in the x86 ELF linker.
201
202 * Add support for GNU_PROPERTY_X86_FEATURE_1_IBT in ELF GNU program
203 properties in the x86 ELF linker.
204
205 * Support for -z ibtplt in the x86 ELF linker to generate IBT-enabled
206 PLT.
207
208 * Support for -z ibt in the x86 ELF linker to generate IBT-enabled
209 PLT as well as GNU_PROPERTY_X86_FEATURE_1_IBT in ELF GNU program
210 properties.
211
212 * Add support for ELF SHF_GNU_MBIND and PT_GNU_MBIND_XXX.
213
214 * Add support for ELF GNU program properties.
215
216 * Add support for the Texas Instruments PRU processor.
217
218 * When configuring for arc*-*-linux* targets the default linker emulation will
219 change if --with-cpu=nps400 is used at configure time.
220
221 * Improve assignment of LMAs to orphan sections in some edge cases where a
222 mixture of both AT>LMA_REGION and AT(LMA) are used.
223
224 * Orphan sections placed after an empty section that has an AT(LMA) will now
225 take an load memory address starting from LMA.
226
227 * Section groups can now be resolved (the group deleted and the group members
228 placed like normal sections) at partial link time either using the new linker
229 option --force-group-allocation or by placing FORCE_GROUP_ALLOCATION into the
230 linker script.
231
232 Changes in 2.28:
233
234 * The EXCLUDE_FILE linker script construct can now be applied outside of the
235 section list in order for the exclusions to apply over all input sections in
236 the list.
237
238 * Add support for the RISC-V architecture.
239
240 * The command-line option --no-eh-frame-hdr can now be used in ELF based
241 linkers to disable the automatic generation of .eh_frame_hdr sections.
242
243 * Add --in-implib=<infile> to the ARM linker to enable specifying a set of
244 Secure Gateway veneers that must exist in the output import library specified
245 by --out-implib=<outfile> and the address they must have. As such,
246 --in-implib is only supported in combination with --cmse-implib.
247
248 * Extended the --out-implib=<file> option, previously restricted to x86 PE
249 targets, to any ELF based target. This allows the generation of an import
250 library for an ELF executable, which can then be used by another application
251 to link against the executable.
252
253 Changes in 2.27:
254
255 * Add a configure option --enable-relro to decide whether -z relro should
256 be enabled in ELF linker by default. Default to yes for all Linux
257 targets except FRV, HPPA, IA64 and MIPS. Note that -z relro can increase
258 disk and memory size.
259
260 * Support for -z noreloc-overflow in the x86-64 ELF linker to disable
261 relocation overflow check.
262
263 * Add -z common/-z nocommon options for ELF targets to control whether to
264 convert common symbols to the STT_COMMON type during a relocatable link.
265
266 * Support for -z nodynamic-undefined-weak in the x86 ELF linker, which
267 avoids dynamic relocations against undefined weak symbols in executable.
268
269 * The NOCROSSREFSTO command was added to the linker script language.
270
271 * Add --no-apply-dynamic-relocs to the AArch64 linker to do not apply link-time
272 values for dynamic relocations.
273
274 Changes in 2.26:
275
276 * Add --fix-stm32l4xx-629360 to the ARM linker to enable a link-time
277 workaround for a bug in the bus matrix / memory controller for some of
278 the STM32 Cortex-M4 based products (STM32L4xx)
279
280 * Add a configure option --enable-compressed-debug-sections={all,ld} to
281 decide whether DWARF debug sections should be compressed by default.
282
283 * Add support for the ARC EM/HS, and ARC600/700 architectures.
284
285 * Experimental support for linker garbage collection (--gc-sections)
286 has been enabled for COFF and PE based targets.
287
288 * New command-line option for ELF targets to compress DWARF debug
289 sections, --compress-debug-sections=[none|zlib|zlib-gnu|zlib-gabi].
290
291 * New command-line option, --orphan-handling=[place|warn|error|discard], to
292 adjust how orphan sections are handled. The default is 'place' which gives
293 the current behaviour, 'warn' and 'error' issue a warning or error
294 respectively when orphan sections are found, and 'discard' will discard all
295 orphan sections.
296
297 * Add support for LLVM plugin.
298
299 * Add --print-memory-usage option to report memory blocks usage.
300
301 * Add --require-defined option, it's like --undefined except the new symbol
302 must be defined by the end of the link.
303
304 Changes in 2.25:
305
306 * PE binaries now once again contain real timestamps by default. To disable
307 the inclusion of a timestamp in a PE binary, use the --no-insert-timestamp
308 command-line option.
309
310 * Replace support for openrisc and or32 with support for or1k.
311
312 * Add support for the --build-id command-line option to COFF based targets.
313
314 * x86/x86_64 pe-coff now supports the --build-id option.
315
316 * Add support for the Andes NDS32.
317
318 Changes in 2.24:
319
320 * Add LOG2CEIL() builtin function to the linker script language
321
322 * Add support for the Texas Instruments MSP430X processor.
323
324 * Add support for Altera Nios II.
325
326 * Add support for the V850E3V5 architecture.
327
328 * Add support for the Imagination Technologies Meta processor.
329
330 * --enable-new-dtags no longer generates old dtags in addition to new dtags.
331
332 * Remove linker support for MIPS ECOFF targets.
333
334 * Add ALIGN_WITH_INPUT to the linker script language to force the alignment of
335 an output section to use the maximum alignment of all its input sections.
336
337 Changes in 2.23:
338
339 * Enable compressed debug section feature for x86/x86_64 pe-coff.
340
341 * Add support for the 64-bit ARM architecture: AArch64.
342
343 * Added SORT_NONE to the linker script language to disable section sorting.
344
345 * Add a linker-provided symbol when producing ELF output, '__ehdr_start'
346 to point to the ELF file header (and nearby program headers) in the
347 program's memory image.
348
349 * Add support for S12X processor.
350
351 * Add support for the VLE extension to the PowerPC architecture.
352
353 * Add support for the Freescale XGATE architecture.
354
355 * Add option -f FILE on AIX (for response file).
356
357 * Add support for the Renesas RL78 architecture.
358
359 * Add support for the Adapteva EPIPHANY architecture.
360
361 Changes in 2.22:
362
363 * --copy-dt-needed-entries is no longer enabled by default. Instead
364 --no-copy-dt-needed-entries is the default.
365
366 * INPUT_SECTION_FLAGS has been added to the linker script language
367 to allow selection of input sections by section header section flags.
368
369 * Add support for the Tilera TILEPro and TILE-Gx architectures.
370
371 * Added SORT_BY_INIT_PRIORITY to the linker script language to permit
372 sorting sections by numerical value of the GCC init_priority attribute
373 encoded in the section name.
374
375 Changes in 2.21:
376
377 * Linker script expression evaluation is somewhat more sane. This may
378 break scripts that depend on quirks of the old expression evaluation.
379
380 * Turn off underscoring for x86_64 PE+-COFF targets. For old behavior the
381 option --enable-leading-mingw64-underscores can be used on configure of
382 bfd.
383
384 * Add support for the TMS320C6000 (TI C6X) processor family.
385
386 * --add-needed renamed to --copy-dt-needed-entries in order to avoid confusion
387 with --as-needed option.
388
389 * Extend .def file syntax by '== <ID>' for imports and exports. This allows
390 to alias the import/export table name written in PE image.
391
392 * Add --exclude-all-symbols option to PE based linkers. This prevents all
393 symbols from automatically being exported.
394
395 * Add support for the Renesas RX processor.
396
397 * Add support for alpha-vms target.
398
399 Changes in 2.20:
400
401 * GNU/Linux targets now support the STB_GNU_UNIQUE symbol binding. This is a
402 GNU extension to the standard set of ELF symbol bindings. The binding will
403 be passed on to the dynamic linker which will make sure that in the entire
404 process there is just one symbol with the given name and type in use.
405
406 * PE targets now support a GNU extension to allow the alignment of common
407 common symbols to be specified. This support uses custom options in
408 the .drectve section, which will be disregarded by the native tools.
409
410 * PE targets now add primitive support for ELF version scripts; symbols
411 are not versioned, but the local and global symbol visibility directives
412 are respected when filtering symbols in auto-export mode.
413
414 * New option --no-export-dynamic to undo the effect of the -E and
415 --export-dynamic options.
416
417 * ELF: --warn-alternate-em option to warn if an object has alternate
418 ELF machine code.
419
420 * New script function REGION_ALIAS to add alias names to memory regions.
421
422 * PE targets no longer make use of the long section names PE extension to
423 the COFF format when generating executable images, by default. The old
424 (slightly non-conformant) behaviour can still be invoked by using the
425 new '--enable-long-section-names' command-line option. It is also enabled
426 automatically in the presence of un-stripped debug information, as GDB
427 needs to be able to find the debug info sections by their full names.
428
429 * For GNU/Linux systems the linker will now avoid processing any relocations
430 made against symbols of the STT_GNU_IFUNC type and instead emit them into
431 the resulting binary for processing by the loader.
432
433 * --as-needed now links in a dynamic library if it satisfies undefined
434 symbols in regular objects, or in other dynamic libraries. In the
435 latter case the library is not linked if it is found in a DT_NEEDED
436 entry of one of the libraries already linked.
437
438 * Add a new command-line option, -Ttext-segment ADDR, for ELF targets
439 to set the address of the first byte of the text segment.
440
441 * Add support for Sunplus score architecture.
442
443 * Add new option --use-nul-prefixed-import-tables to ld for PE targets to
444 allow fallback to old import table generation with null element prefix.
445
446 * Windows PE systems now support a new --exclude-modules-for-implib option,
447 allowing users to partition object files and archive members between a DLL
448 and its associated import library as they are generated during linking.
449
450 * Add support for Lattice Mico32 (lm32) architecture.
451
452 * Add CR16 ELF --embedded-relocs (used to embedded relocations into binaries
453 for Embedded-PIC code) option.
454
455 * Add to the PE/PE+ targets the support of two different kinds of
456 pseudo-relocations. They can be selected by the switches
457 --enable-runtime-pseudo-reloc-v1 and --enable-runtime-pseudo-reloc-v2.
458 For the switch --enable-runtime-pseudo-reloc it uses for 32-bit
459 runtime pseudo relocation version one, for 64-bit the version two.
460
461 Changes in 2.19:
462
463 * Linker scripts support a new INSERT command that makes it easier to
464 augment the default script.
465
466 * Linker script input section filespecs may now specify a file within an
467 archive by writing "archive:file".
468
469 * The --sort-common switch now has an optional argument which specifies the
470 direction of sorting.
471
472 * The M68K linker now supports multiple GOT generation schemes controlled via
473 the --got=<type> command-line option.
474
475 * The ARM EABI linker will now generate stubs for function calls to symbols
476 that are too far away. The placement of the stubs is controlled by a new
477 linker command-line option: --stub-group-size=N.
478
479 Changes in 2.18:
480
481 * Linker sources now released under version 3 of the GNU General Public
482 License.
483
484 * ELF: New --build-id option to generate a unique per-binary identifier
485 embedded in a note section.
486
487 * Added support for National Semicondutor CompactRISC (ie CR16) target.
488
489 * -l:foo now searches the library path for a filename called foo,
490 without converting it to libfoo.a or libfoo.so.
491
492 * Add a new command-line option '--default-script=FILE' or '-dT FILE'
493 which specifies a replacement for the built in, default linker
494 script.
495
496 * ELF: Add -Bsymbolic-functions, --dynamic-list-cpp-new, which puts C++
497 operator new and delete on the dynamic list, and --dynamic-list-data,
498 builtin list for --dynamic-list, which puts global data symbols on the
499 dynamic list.
500
501 * Add support for x86_64 PE+ target.
502
503 * Add support for Score target.
504
505 * ELF: Add --dynamic-list option to specify a list of global symbols
506 whose references shouldn't be bound to the definition within the
507 shared library, or a list of symbols which should be added to the
508 symbol table in the executable.
509
510 * The default output section LMA has changed for allocatable sections from
511 being equal to VMA, to keeping the difference between LMA and VMA the same as
512 the previous output section in the same region. This is a more useful
513 default when using overlays and other cases where you specify an LMA
514 differing from the VMA for some sections.
515
516 * New switch: --print-gc-sections to list any sections removed by garabge
517 collection.
518
519 * ARM: Added --vfp11-denorm-fix option to work around an erratum in current
520 VFP11 coprocessors.
521
522 Changes in 2.17:
523
524 * Support for the Infineon XC16X has been added by KPIT Cummins Infosystems.
525
526 * Modify the Linux linker search order to better match ld.so search order.
527 Look for DT_NEEDED libraries in paths specified by ld.so.conf before
528 searching the default directories, rather than vice versa.
529 Use $prefix/etc/ld.so.conf if it exists, otherwise /etc/ld.so.conf.
530
531 * PE-COFF: Forward exports from DLL's can now be specified in .def files
532 passed directly to ld.
533
534 * Support for the Z80 processor family has been added.
535
536 * Add support for the "@<file>" syntax to the command line, so that extra
537 switches can be read from <file>.
538
539 Changes in 2.16:
540
541 * Support for the R_ARM_V4BX relocation as defined in the ARM AAELF
542 specification has been added via the --fix-v4bx command-line option.
543
544 * New linker script construct AS_NEEDED(), which sets the --as-needed flag
545 for input files listed inside of it.
546
547 * A new command-line option, --sysroot, can be used to override the
548 default sysroot location. It only applies to toolchains that were
549 configured using --with-sysroot.
550
551 * New linker script functions: ORIGIN() and LENGTH() which return information
552 about a specified memory region.
553
554 * Port to MAXQ processor contributed by HCL Tech.
555
556 * Added SEGMENT_START to the linker script language to permit the user to
557 override the base address for a segment from the command-line.
558
559 * ELF: --warn-shared-textrel option to warn if adding a DT_TEXTREL to a shared
560 object.
561
562 * Added SORT_BY_NAME and SORT_BY_ALIGNMENT to the linker script
563 language to permit sorting sections by section name or section
564 maximum alignment.
565
566 * Added a new linker command-line switch, --sort-section name|alignment,
567 to sort sections by section name or maximum alignment.
568
569 * ELF: --add-needed/--no-add-needed options to control if a DT_NEEDED tag
570 should be added when a shared library comes from DT_NEEDED tags.
571
572 * Support for the crx-elf target added.
573
574 * Support for the sh-symbianelf target added.
575
576 * A new linker command-line switch has been added which allows the hash table
577 size to be set to a suitable prime value near to its argument. This switch
578 is --hash-size=<NUMBER>. Also if the switch --reduce-memory-overheads is
579 used, and --hash-size has not been used, then the default value will be set
580 to 1021.
581
582 * Linker map files are now generated with an O(N) algorithm for finding symbols
583 that are defined in each section. This uses about 40% more memory for
584 symbols than the old O(N^2) algorithm. You can use the new
585 --reduce-memory-overheads option to select the old algorithm; this option
586 might also be used in the future to select similar tradeoffs.
587
588 Changes in 2.15:
589
590 * ELF: --as-needed/--no-as-needed options to control if a DT_NEEDED tag should
591 be added only when a shared library is referenced.
592
593 * PE: --large-address-aware option to indicate executables support virtual
594 addresses greater than 2 gigabytes.
595
596 * DWARF 2 support for i386pe added.
597
598 * The linker script operator DEFINED() will now yield 1 only for a symbol that
599 is defined before the statement where DEFINED is used.
600
601 * The MIPS --embedded-relocs (used to embed relocations into binaries for
602 Embedded-PIC code) is deprecated and will be removed in a future release.
603
604 * cr16c support added by NSC.
605
606 * m32r Linux (ELF) support added by Renesas.
607
608 * Improved linker's handling of unresolved symbols. The switch
609 --unresolved-symbols=<method> has been added to tell the linker when it
610 should report them and the switch --warn-unresolved-symbols has been added to
611 make reports be issued as warning messages rather than errors.
612
613 Changes in 2.14:
614
615 * Added support for Xtensa architecture.
616
617 * Added --with-sysroot configure switch to specify a target system root, for
618 linking against a target filesystem image.
619
620 * Added --accept-unknown-linker-format to restore old linker behaviour (pre
621 2.14) of silently accepting and linking in any files in an unknown binary
622 file format.
623
624 * Added --no-omagic to undo the effects of the -N option.
625
626 * Support for Texas Instruments TMS320C4x and TMS320C3x series of
627 DSP's contributed by Michael Hayes and Svein E. Seldal.
628
629 * Added --with-lib-path configure switch to specify default value for
630 LIB_PATH.
631
632 * ARM port to QNX operating system added by Graeme Peterson.
633
634 * IP2K support added by Denis Chertykov.
635
636 Changes in 2.13:
637
638 * Support for the Fujitsu FRV architecture added by Red Hat. Models for FR400
639 and FR500 included.
640
641 Changes in version 2.13:
642
643 * DEC VAX ELF support, by Matt Thomas.
644
645 Changes in version 2.12:
646
647 * Support for Don Knuth's MMIX, by Hans-Peter Nilsson.
648
649 * Support for the OpenRISC 32-bit embedded processor by OpenCores.
650
651 * Support for -z nocopyreloc in the x86 ELF linker, which disables
652 production of copy relocs. Warning: using this option may result in
653 non-sharable applications.
654
655 * Support for -z combreloc in the ELF linker, which puts dynamic
656 relocations against the same symbol together, so that dynamic linker
657 can use an one-entry symbol lookup cache.
658
659 * Support for ELF SHF_MERGE section merging, by Jakub Jelinek.
660
661 Changes in version 2.11:
662
663 * Support for AMD x86-64 architecture, by Jan Hubicka, SuSE Labs.
664
665 * Support added for eliminating duplicate DWARF2 debug information by
666 having the compiler generate the information in sections called
667 .gnu.linkonce.wi.XXXX where XXXX is a checksum for the contents. The
668 linker then merges these sections together into the normal .debug_info
669 section.
670
671 * The native ELF linker now searches the directories in DT_RUNPATH or
672 DT_RPATH of a shared library for shared libraries needed by it.
673
674 * TI C54x support, by Timothy Wall.
675
676 * Added command-line switch --section-start to set the start address of any
677 specified section.
678
679 * Added ability to emit full relocation information in linked executables,
680 enabled by --emit-relocs. Some post-linkage optimization tools need
681 this information in order to be able to correctly identify and perform
682 symbol relative addressing in the event of changes in section contents
683 (instructions being added or deleted, extending data sections, etc.)
684
685 * Support for i860, by Jason Eckhardt (preliminary, alpha quality).
686
687 * Support for CRIS (Axis Communications ETRAX series).
688
689 * Support for PDP-11 and 2.11BSD a.out format, by Lars Brinkhoff.
690
691 Changes in version 2.10:
692
693 * Added AT> to the linker script language to allow load-time allocation of
694 sections into regions.
695
696 * Added garbage collection of unused sections, enabled by --gc-sections.
697 It does require a bit of backend support; currently implemented are
698 arm-elf, avr-elf, d10v-elf, fr30-elf, i386-elf, m32r-elf, m68k-elf,
699 mcore-elf, mips-elf, mn10300-elf, ppc-elf, sh-elf, sparc-elf, and v850-elf.
700 Others will ignore the option.
701
702 * Added SORT to the linker script language to permit sorting sections by file
703 name or section name.
704
705 * Added EXTERN to the linker script language as an equivalent to the -u
706 command-line option.
707
708 * Added ASSERT to the linker script language.
709
710 * Added EXCLUDE_FILE to the linker script language for further control over
711 wildcard file names.
712
713 * Added -O option to optimize linker output (as of this writing, this only
714 affects ELF shared library generation).
715
716 * The -e option now accepts a number as well as a symbol name.
717
718 * Added --no-undefined option to disallow undefined symbols when creating a
719 shared library.
720
721 * The linker now issues a warning, not an error, for an undefined symbol when
722 using -Bsymbolic; use the new --no-undefined option to get the old
723 behaviour.
724
725 * Added --demangle and --no-demangle options.
726
727 Changes in version 2.9:
728
729 * Added SQUAD to the linker script language.
730
731 * New option --no-warn-mismatch.
732
733 * The MEMORY command now parses the attributes to determine where sections that
734 are not placed in a specific memory region are placed.
735
736 Changes in version 2.8:
737
738 * Linker scripts may now contain shell wildcard characters for file and section
739 names.
740
741 * The linker now supports symbol versions in ELF.
742
743 * The NOCROSSREFS command was added to the linker script language.
744
745 * The LOADADDR expression was added to the linker script language.
746
747 * MAX and MIN functions were added to the linker script language.
748
749 * The OVERLAY construct was added to the linker script language.
750
751 * New option --warn-section-align to warn when the address of an output section
752 changes due to alignment of an input section.
753
754 * New options --filter/-F and --auxiliary/-f.
755
756 Changes in version 2.7:
757
758 * New option --cref to print out a cross reference table.
759
760 * New option --wrap SYMBOL.
761
762 * New option --no-whole-archive, to turn off the effect of --whole-archive.
763
764 * Input sections assigned to the output section /DISCARD/ in the linker script
765 are not included in the output file.
766
767 * The SunOS and ELF linkers now merge stabs debugging information which uses
768 the N_BINCL and N_EINCL stab types. This reduces the amount of debugging
769 information generated.
770
771 Changes in version 2.6:
772
773 * When an ELF section name is representable as a C identifier (this is not true
774 of most ELF section names), the linker will automatically define symbols
775 __start_SECNAME and __stop_SECNAME, where SECNAME is the section name, at the
776 beginning and the end of the section. This is used by glibc.
777
778 Addendum: Current versions of the linker (at least for version 2.18 onwards
779 and possibly much earlier as well) place two restrictions on this feature: The
780 symbols are only implemented for orphaned sections, not for explicitly placed
781 sections and they are PROVIDEd rather than being defined.
782
783 * When an ELF section named .gnu.warning is encountered in an input file, the
784 contents of the section are displayed as an error message, and the section is
785 not copied into the output file. This is used by glibc.
786
787 * When an ELF section named .gnu.warning.SYMBOL is encountered in an input
788 file, and the symbol SYMBOL is referenced by some object file, the contents of
789 the section are displayed as an error message. The section is not copied into
790 the output file, unless doing a relocatable or shared link. This is used by
791 glibc.
792
793 * New options -split-by-reloc and -split-by-file.
794
795 * The linker now supports linking PIC compiled code on SPARC SunOS. It can
796 also create SPARC SunOS shared libraries, and, like the native SunOS linker,
797 will do so whenever there is an undefined symbol in the link and neither the -e
798 nor the -r option was used.
799
800 * The -rpath option may be used on SunOS to set the list of directories to be
801 searched at run time. This overrides the default of building the list from the
802 -L options.
803
804 * The COFF linker now combines debugging information for structs, unions, and
805 enums, so that even if the same type is defined in multiple input files it will
806 only be defined once in the output file. The --traditional-format switch will
807 prevent this optimization.
808
809 Changes in version 2.5:
810
811 * The linker now supports linking against SunOS shared libraries. It still can
812 not link SunOS PIC (Position Independent Code) files, so it can not be used to
813 generate shared libraries.
814
815 * The linker now supports linking against ELF shared libraries for the i386
816 (UnixWare) and SPARC (Solaris). It can also link ELF PIC files, and can be
817 used to generate shared libraries. Shared library generation is not well
818 tested; please report any problems encountered. The linker is now enabled for
819 Solaris again.
820
821 * Eric Youngdale has contributed Linux support code, including linking against
822 Linux a.out shared libraries. The linker produces Linux QMAGIC binaries.
823
824 * The ELF backend has been converted to the new linker code. To use the new
825 ELF linker, each particular target requires a relocation function. So far,
826 this function has been written for i386 (UnixWare), SPARC (Solaris) MIPS (Irix
827 5), and HPPA ELF targets.
828
829 * The -( (--start-group) and -) (--end-group) options have been added to
830 support searching a group of archives as though they were a single archive.
831 This can also be used in a linker script, as GROUP ( files ).
832
833 * When a file is named on the command line, and the linker does not recognize
834 it as an object file, the linker will now treat the file as a linker script
835 file. A linker script named in this way augments, but does not replace, the
836 default linker script.
837
838 * The -warn-once option was added. It causes the linker to only warn once per
839 undefined symbol, rather than once per reference.
840
841 * The COFF backend has been converted to the new linker code. As with ELF, to
842 use the new linker, each particular target requires a relocation function. So
843 far, this function has been written for the i386, m68k, a29k and SH targets.
844
845 * The -V flag was made a synonym for -v, for SVR4 compatibility. The old -V
846 behaviour is available via --verbose.
847
848 Changes in version 2.4:
849
850 * New linker code, by Steve Chamberlain and Ian Taylor. For a.out and ecoff
851 formats (so far), this should result in considerable savings in time
852 and memory used while linking; slightly poorer performance than
853 before for formats not converted yet.
854
855 * Command-line parsing is no longer done with flex. This means
856 oddball characters in filenames won't get treated as argument
857 separators.
858
859 * HP-PA ELF support, by Jeff Law. (No SOM support yet.)
860
861 * Mach i386 support, by David Mackenzie.
862
863 * Irix 4 shared libraries are now supported (Irix 5 uses ELF, and ELF shared
864 libraries are not yet supported).
865
866 * COFF shared libraries (as on SCO) should work as well.
867
868 * The linker is disabled for Solaris. (Actually, it was in 2.3 also, I just
869 forgot to note it.) Some of their C library routines don't work when
870 statically linked, and the GNU linker doesn't support dynamic linking yet.
871
872 Changes in version 2.3:
873
874 * Weak symbols are now supported.
875
876 * ELF support has been added. The linker has been bootstrapped on
877 UnixWare and Solaris.
878
879 * Alpha OSF/1 support has been added (non dynamic linking only).
880
881 Changes in version 2.2:
882
883 * The `bfd' library has been updated to reduce a.out-format string
884 table size. The effect of this is that files linked from many input
885 files with duplicate symbols (`-g' debugging records, or identical
886 static symbols) should be much smaller.
887
888 Changes in version 2.1:
889
890 * The ld -ySYMBOL flag (to trace references to SYMBOL) is now implemented.
891
892 * There is now support for writing ECOFF files, so ld and the
893 other utilities should work on Risc/Ultrix and Irix.
894
895 \f
896 Copyright (C) 2012-2022 Free Software Foundation, Inc.
897
898 Copying and distribution of this file, with or without modification,
899 are permitted in any medium without royalty provided the copyright
900 notice and this notice are preserved.
901
902 Local variables:
903 fill-column: 79
904 End: