Accept and ignore the R_BPF_64_NODLYD32 relocation.
[binutils-gdb.git] / ld / NEWS
1 -*- text -*-
2
3 Changes in 2.41:
4
5 * Add support for the KVX instruction set.
6
7 * The linker now accepts a command line option of --remap-inputs
8 <PATTERN>=<FILE> to relace any input file that matches <PATTERN> with
9 <FILE>. In addition the option --remap-inputs-file=<FILE> can be used to
10 specify a file containing any number of these remapping directives.
11
12 * The linker command line option --print-map-locals can be used to include
13 local symbols in a linker map. (ELF targets only).
14
15 * For most ELF based targets, if the --enable-linker-version option is used
16 then the version of the linker will be inserted as a string into the .comment
17 section.
18
19 * The linker script syntax has a new command for output sections: ASCIZ "string"
20 This will insert a zero-terminated string at the current location.
21
22 * Add command-line option, -z nosectionheader, to omit ELF section
23 header.
24
25 Changes in 2.40:
26
27 * The linker has a new command line option to suppress the generation of any
28 warning or error messages. This can be useful when there is a need to create
29 a known non-working binary. The option is -w or --no-warnings.
30
31 * ld now supports zstd compressed debug sections. The new option
32 --compress-debug-sections=zstd compresses debug sections with zstd.
33
34 * Add --enable-default-compressed-debug-sections-algorithm={zlib,zstd}
35 that selects the default compression algorithm
36 for --enable-compressed-debug-sections.
37
38 * Remove support for -z bndplt (MPX prefix instructions).
39
40 Changes in 2.39:
41
42 * The ELF linker will now generate a warning message if the stack is made
43 executable. By default this warning is not issued if the user has
44 specifically requested an executable stack via the "-z execstack"
45 command line option, but the warning can be forced via the new
46 "--warn-execstack" option. Alternatively all warnings about creating
47 an executable stack can be suppressed via the "--no-warn-execstack"
48 option.
49
50 In addition the ELF linker will also warn if it creates a memory resident
51 segment with all three of the Read, Write and eXecute permissions set, or
52 if it creates a thread local data segment with the eXecute permission set.
53 These warnings can be disabled via --no-warn-rwx-segments option and
54 re-enabled via the --warn-rwx-segments option.
55
56 New configure options can also control these new features:
57
58 --enable-warn-execstack=no
59 will disable the warnings about creating an executable stack.
60
61 --enable-warn-execstack=yes
62 will make --warn-execstack enabled by default.
63
64 --enable-warn-rwx-segments=no
65 will make --no-warn-rwx-segments enabled by default.
66
67 --enable-default-execstack=no
68 will stop the creation of an executable stack simply because an input file
69 is missing a .note.GNU-stack section, even on architectures where this
70 behaviour is the default.
71
72 * TYPE=<type> is now supported in an output section description to set the
73 section type value.
74
75 * Remove (rudimentary) support for the x86-64 sub-architectures Intel L1OM and
76 Intel K1OM.
77
78 * The ELF linker now supports a new --package-metadata option that allows
79 embedding a JSON payload in accordance to the Package Metadata specification.
80 If support for libjansson is enabled at build time, the linker will use it to
81 validate the input. This can be enabled with --enable-jansson.
82 For more details, see: https://systemd.io/ELF_PACKAGE_METADATA/
83
84 Changes in 2.38:
85
86 * Add -z pack-relative-relocs/-z no pack-relative-relocs to x86 ELF
87 linker to pack relative relocations in the DT_RELR section.
88
89 * Add support for the LoongArch architecture.
90
91 * Add -z indirect-extern-access/-z noindirect-extern-access to x86 ELF
92 linker to control canonical function pointers and copy relocation.
93
94 * Add --max-cache-size=SIZE to set the the maximum cache size to SIZE
95 bytes.
96
97 Changes in 2.37:
98
99 * arm-symbianelf support removed.
100
101 * Add -z report-relative-reloc to x86 ELF linker to report dynamic
102 relative relocations.
103
104 * Add -z start-stop-gc to disable special treatment of __start_*/__stop_*
105 references when --gc-sections.
106
107 * Add -Bno-symbolic to cancel -Bsymbolic and -Bsymbolic-functions.
108
109 Changes in 2.36:
110
111 * Add libdep plugin, for linking dependencies of static libraries that
112 were recorded by ar in the __.LIBDEP archive member.
113
114 * Add --error-handling-script=<NAME> command line option to allow a helper
115 script to be invoked when an undefined symbol or a missing library is
116 encountered. This option can be suppressed via the configure time
117 switch: --enable-error-handling-script=no.
118
119 * Add -z lam-u48 to x86-64 ELF linker to generate LAM_U48 property.
120
121 * Add -z lam-u57 to x86-64 ELF linker to enerate LAM_U57 property.
122
123 * Add -z lam-u48-report=[none|warning|error] to report missing LAM_U48
124 property.
125
126 * Add -z lam-u57-report=[none|warning|error] to report missing LAM_U57
127 property.
128
129 * Add -z lam-report=[none|warning|error] to report missing LAM_U48 and
130 LAM_U57 properties.
131
132 * Add -z x86-64-{baseline|v[234]} to the x86 ELF linker to mark
133 x86-64-{baseline|v[234]} ISA level as needed.
134
135 * Add -z unique-symbol to avoid duplicated local symbol names.
136
137 * The creation of PE format DLLs now defaults to using a more secure set of DLL
138 characteristics.
139
140 * The linker now deduplicates the types in .ctf sections. The new
141 command-line option --ctf-share-types describes how to do this:
142 its default value, share-unconflicted, produces the most compact
143 output.
144
145 * The linker now omits the "variable section" from .ctf sections by
146 default, saving space. This is almost certainly what you want
147 unless you are working on a project that has its own analogue
148 of symbol tables that are not reflected in the ELF symtabs.
149
150 * Add support for the SHF_GNU_RETAIN ELF section flag.
151 This flag specifies that the section should not be garbage collected by the
152 linker.
153
154 Changes in 2.35:
155
156 * X86 NaCl target support is removed.
157
158 * Add ELF linker command-line options, --export-dynamic-symbol and
159 --export-dynamic-symbol-list, to make symbols dynamic.
160
161 * Add a configure option, --enable-textrel-check=[no|yes|warning|error],
162 to decide what ELF linker should do by default with DT_TEXTREL in an
163 executable or shared library. Default to yes for Linux/x86 targets.
164
165 * The -Map=<filename> command line option has been extended so that if
166 <filename> is a directory then <filename>/<output-filename>.map will be
167 created.
168
169 * Add a command-line option for ELF linker, --warn-textrel, to warn that
170 DT_TEXTREL is set in a position-independent executable or shared object.
171
172 * Add command-line options --enable-non-contiguous-regions and
173 --enable-non-contiguous-regions-warnings.
174
175 * Add command-line option --imagic for the pdp11-aout target to output format
176 IMAGIC (0411) for separate instruction and data spaces, and change the
177 default format option for pdp11-aout to be --omagic.
178
179 * Relative pathnames in INPUT() and GROUP() directives in linker scripts are
180 searched relative to the directory of the linker script before other search
181 paths.
182
183 * Add ELF linker command-line option `-z start-stop-visibility=...' to control
184 the visibility of synthetic `__start_SECNAME` and `__stop_SECNAME` symbols.
185
186 * Add command-line option --dependency-file to write a Make-style dependency
187 file listing the input files consulted by the linker, like the files written
188 by the compiler's -M -MP options.
189
190 Changes in 2.34:
191
192 * The ld check for "PHDR segment not covered by LOAD segment" is more
193 effective, catching cases that were wrongly allowed by previous versions of
194 ld. If you see this error it is likely you are linking with a bad linker
195 script or the binary you are building is not intended to be loaded by a
196 dynamic loader. In the latter case --no-dynamic-linker is appropriate.
197
198 * cr16c support removed.
199
200 * Add support for z80-elf.
201
202 * Add support for relocation of each byte or word of multibyte value to Z80
203 targets.
204
205 * Add support for Zilog eZ80 (both ADL and Z80 mode) and Zilog Z180 CPUs.
206
207 Changes in 2.33:
208
209 * Add command-line option --no-print-map-discarded.
210
211 * The Cortex-A53 Erratum 843419 workaround now supports a choice of which
212 workaround to use. The option --fix-cortex-a53-843419 now takes an
213 optional argument --fix-cortex-a53-843419[=full|adr|adrp] which can be
214 used to force a particular workaround to be used. See --help for AArch64
215 for more details.
216
217 * Add target handlers for AArch64 for ELF GNU program properties.
218
219 * Add support for GNU_PROPERTY_AARCH64_FEATURE_1_BTI in ELF GNU program
220 properties in the AArch64 ELF linker.
221
222 * Add support for GNU_PROPERTY_AARCH64_FEATURE_1_PAC in ELF GNU program
223 properties in the AArch64 ELF linker.
224
225 * Add -z force-bti for AArch64 to enable GNU_PROPERTY_AARCH64_FEATURE_1_BTI
226 on output while warning about missing GNU_PROPERTY_AARCH64_FEATURE_1_BTI
227 on inputs and use PLTs protected with BTI.
228
229 * Add -z pac-plt for AArch64 to pick PAC enabled PLTs.
230
231 Changes in 2.32:
232
233 * Report property change in linker map file when merging GNU properties.
234
235 * Add support for the C-SKY processor series.
236
237 * -t now doesn't report members within archives, unless -t is given twice.
238 A single -t is now more useful when generating a list of files that should be
239 packaged for a linker bug report. For example:
240 gcc hello.c -save-temps -Wl,-t | xargs realpath | sort | uniq > files
241 tar cJf test.tar.xz `cat files`
242
243 Changes in 2.31:
244
245 * Speed up direct linking with DLLs for Cygwin and Mingw targets.
246
247 * Add a configure option --enable-separate-code to decide whether
248 -z separate-code should be enabled in ELF linker by default. Default
249 to yes for Linux/x86 targets. Note that -z separate-code can increase
250 disk and memory size.
251
252 Changes in 2.30:
253
254 * Add -z separate-code to generate separate code PT_LOAD segment.
255
256 * Add "-z undefs" command-line option as the inverse of the "-z defs" option.
257
258 * Add -z globalaudit command-line option to force audit libraries to be run
259 for every dynamic object loaded by an executable - provided that the loader
260 supports this functionality.
261
262 * Tighten linker script grammar around file name specifiers to prevent the use
263 of SORT_BY_ALIGNMENT and SORT_BY_INIT_PRIORITY on filenames. These would
264 previously be accepted but had no effect.
265
266 * The EXCLUDE_FILE directive can now be placed within any SORT_* directive
267 within input section lists.
268
269 Changes in 2.29:
270
271 * Support for -z shstk in the x86 ELF linker to generate
272 GNU_PROPERTY_X86_FEATURE_1_SHSTK in ELF GNU program properties.
273
274 * Add support for GNU_PROPERTY_X86_FEATURE_1_SHSTK in ELF GNU program
275 properties in the x86 ELF linker.
276
277 * Add support for GNU_PROPERTY_X86_FEATURE_1_IBT in ELF GNU program
278 properties in the x86 ELF linker.
279
280 * Support for -z ibtplt in the x86 ELF linker to generate IBT-enabled
281 PLT.
282
283 * Support for -z ibt in the x86 ELF linker to generate IBT-enabled
284 PLT as well as GNU_PROPERTY_X86_FEATURE_1_IBT in ELF GNU program
285 properties.
286
287 * Add support for ELF SHF_GNU_MBIND and PT_GNU_MBIND_XXX.
288
289 * Add support for ELF GNU program properties.
290
291 * Add support for the Texas Instruments PRU processor.
292
293 * When configuring for arc*-*-linux* targets the default linker emulation will
294 change if --with-cpu=nps400 is used at configure time.
295
296 * Improve assignment of LMAs to orphan sections in some edge cases where a
297 mixture of both AT>LMA_REGION and AT(LMA) are used.
298
299 * Orphan sections placed after an empty section that has an AT(LMA) will now
300 take an load memory address starting from LMA.
301
302 * Section groups can now be resolved (the group deleted and the group members
303 placed like normal sections) at partial link time either using the new linker
304 option --force-group-allocation or by placing FORCE_GROUP_ALLOCATION into the
305 linker script.
306
307 Changes in 2.28:
308
309 * The EXCLUDE_FILE linker script construct can now be applied outside of the
310 section list in order for the exclusions to apply over all input sections in
311 the list.
312
313 * Add support for the RISC-V architecture.
314
315 * The command-line option --no-eh-frame-hdr can now be used in ELF based
316 linkers to disable the automatic generation of .eh_frame_hdr sections.
317
318 * Add --in-implib=<infile> to the ARM linker to enable specifying a set of
319 Secure Gateway veneers that must exist in the output import library specified
320 by --out-implib=<outfile> and the address they must have. As such,
321 --in-implib is only supported in combination with --cmse-implib.
322
323 * Extended the --out-implib=<file> option, previously restricted to x86 PE
324 targets, to any ELF based target. This allows the generation of an import
325 library for an ELF executable, which can then be used by another application
326 to link against the executable.
327
328 Changes in 2.27:
329
330 * Add a configure option --enable-relro to decide whether -z relro should
331 be enabled in ELF linker by default. Default to yes for all Linux
332 targets except FRV, HPPA, IA64 and MIPS. Note that -z relro can increase
333 disk and memory size.
334
335 * Support for -z noreloc-overflow in the x86-64 ELF linker to disable
336 relocation overflow check.
337
338 * Add -z common/-z nocommon options for ELF targets to control whether to
339 convert common symbols to the STT_COMMON type during a relocatable link.
340
341 * Support for -z nodynamic-undefined-weak in the x86 ELF linker, which
342 avoids dynamic relocations against undefined weak symbols in executable.
343
344 * The NOCROSSREFSTO command was added to the linker script language.
345
346 * Add --no-apply-dynamic-relocs to the AArch64 linker to do not apply link-time
347 values for dynamic relocations.
348
349 Changes in 2.26:
350
351 * Add --fix-stm32l4xx-629360 to the ARM linker to enable a link-time
352 workaround for a bug in the bus matrix / memory controller for some of
353 the STM32 Cortex-M4 based products (STM32L4xx)
354
355 * Add a configure option --enable-compressed-debug-sections={all,ld} to
356 decide whether DWARF debug sections should be compressed by default.
357
358 * Add support for the ARC EM/HS, and ARC600/700 architectures.
359
360 * Experimental support for linker garbage collection (--gc-sections)
361 has been enabled for COFF and PE based targets.
362
363 * New command-line option for ELF targets to compress DWARF debug
364 sections, --compress-debug-sections=[none|zlib|zlib-gnu|zlib-gabi].
365
366 * New command-line option, --orphan-handling=[place|warn|error|discard], to
367 adjust how orphan sections are handled. The default is 'place' which gives
368 the current behaviour, 'warn' and 'error' issue a warning or error
369 respectively when orphan sections are found, and 'discard' will discard all
370 orphan sections.
371
372 * Add support for LLVM plugin.
373
374 * Add --print-memory-usage option to report memory blocks usage.
375
376 * Add --require-defined option, it's like --undefined except the new symbol
377 must be defined by the end of the link.
378
379 Changes in 2.25:
380
381 * PE binaries now once again contain real timestamps by default. To disable
382 the inclusion of a timestamp in a PE binary, use the --no-insert-timestamp
383 command-line option.
384
385 * Replace support for openrisc and or32 with support for or1k.
386
387 * Add support for the --build-id command-line option to COFF based targets.
388
389 * x86/x86_64 pe-coff now supports the --build-id option.
390
391 * Add support for the Andes NDS32.
392
393 Changes in 2.24:
394
395 * Add LOG2CEIL() builtin function to the linker script language
396
397 * Add support for the Texas Instruments MSP430X processor.
398
399 * Add support for Altera Nios II.
400
401 * Add support for the V850E3V5 architecture.
402
403 * Add support for the Imagination Technologies Meta processor.
404
405 * --enable-new-dtags no longer generates old dtags in addition to new dtags.
406
407 * Remove linker support for MIPS ECOFF targets.
408
409 * Add ALIGN_WITH_INPUT to the linker script language to force the alignment of
410 an output section to use the maximum alignment of all its input sections.
411
412 Changes in 2.23:
413
414 * Enable compressed debug section feature for x86/x86_64 pe-coff.
415
416 * Add support for the 64-bit ARM architecture: AArch64.
417
418 * Added SORT_NONE to the linker script language to disable section sorting.
419
420 * Add a linker-provided symbol when producing ELF output, '__ehdr_start'
421 to point to the ELF file header (and nearby program headers) in the
422 program's memory image.
423
424 * Add support for S12X processor.
425
426 * Add support for the VLE extension to the PowerPC architecture.
427
428 * Add support for the Freescale XGATE architecture.
429
430 * Add option -f FILE on AIX (for response file).
431
432 * Add support for the Renesas RL78 architecture.
433
434 * Add support for the Adapteva EPIPHANY architecture.
435
436 Changes in 2.22:
437
438 * --copy-dt-needed-entries is no longer enabled by default. Instead
439 --no-copy-dt-needed-entries is the default.
440
441 * INPUT_SECTION_FLAGS has been added to the linker script language
442 to allow selection of input sections by section header section flags.
443
444 * Add support for the Tilera TILEPro and TILE-Gx architectures.
445
446 * Added SORT_BY_INIT_PRIORITY to the linker script language to permit
447 sorting sections by numerical value of the GCC init_priority attribute
448 encoded in the section name.
449
450 Changes in 2.21:
451
452 * Linker script expression evaluation is somewhat more sane. This may
453 break scripts that depend on quirks of the old expression evaluation.
454
455 * Turn off underscoring for x86_64 PE+-COFF targets. For old behavior the
456 option --enable-leading-mingw64-underscores can be used on configure of
457 bfd.
458
459 * Add support for the TMS320C6000 (TI C6X) processor family.
460
461 * --add-needed renamed to --copy-dt-needed-entries in order to avoid confusion
462 with --as-needed option.
463
464 * Extend .def file syntax by '== <ID>' for imports and exports. This allows
465 to alias the import/export table name written in PE image.
466
467 * Add --exclude-all-symbols option to PE based linkers. This prevents all
468 symbols from automatically being exported.
469
470 * Add support for the Renesas RX processor.
471
472 * Add support for alpha-vms target.
473
474 Changes in 2.20:
475
476 * GNU/Linux targets now support the STB_GNU_UNIQUE symbol binding. This is a
477 GNU extension to the standard set of ELF symbol bindings. The binding will
478 be passed on to the dynamic linker which will make sure that in the entire
479 process there is just one symbol with the given name and type in use.
480
481 * PE targets now support a GNU extension to allow the alignment of common
482 common symbols to be specified. This support uses custom options in
483 the .drectve section, which will be disregarded by the native tools.
484
485 * PE targets now add primitive support for ELF version scripts; symbols
486 are not versioned, but the local and global symbol visibility directives
487 are respected when filtering symbols in auto-export mode.
488
489 * New option --no-export-dynamic to undo the effect of the -E and
490 --export-dynamic options.
491
492 * ELF: --warn-alternate-em option to warn if an object has alternate
493 ELF machine code.
494
495 * New script function REGION_ALIAS to add alias names to memory regions.
496
497 * PE targets no longer make use of the long section names PE extension to
498 the COFF format when generating executable images, by default. The old
499 (slightly non-conformant) behaviour can still be invoked by using the
500 new '--enable-long-section-names' command-line option. It is also enabled
501 automatically in the presence of un-stripped debug information, as GDB
502 needs to be able to find the debug info sections by their full names.
503
504 * For GNU/Linux systems the linker will now avoid processing any relocations
505 made against symbols of the STT_GNU_IFUNC type and instead emit them into
506 the resulting binary for processing by the loader.
507
508 * --as-needed now links in a dynamic library if it satisfies undefined
509 symbols in regular objects, or in other dynamic libraries. In the
510 latter case the library is not linked if it is found in a DT_NEEDED
511 entry of one of the libraries already linked.
512
513 * Add a new command-line option, -Ttext-segment ADDR, for ELF targets
514 to set the address of the first byte of the text segment.
515
516 * Add support for Sunplus score architecture.
517
518 * Add new option --use-nul-prefixed-import-tables to ld for PE targets to
519 allow fallback to old import table generation with null element prefix.
520
521 * Windows PE systems now support a new --exclude-modules-for-implib option,
522 allowing users to partition object files and archive members between a DLL
523 and its associated import library as they are generated during linking.
524
525 * Add support for Lattice Mico32 (lm32) architecture.
526
527 * Add CR16 ELF --embedded-relocs (used to embedded relocations into binaries
528 for Embedded-PIC code) option.
529
530 * Add to the PE/PE+ targets the support of two different kinds of
531 pseudo-relocations. They can be selected by the switches
532 --enable-runtime-pseudo-reloc-v1 and --enable-runtime-pseudo-reloc-v2.
533 For the switch --enable-runtime-pseudo-reloc it uses for 32-bit
534 runtime pseudo relocation version one, for 64-bit the version two.
535
536 Changes in 2.19:
537
538 * Linker scripts support a new INSERT command that makes it easier to
539 augment the default script.
540
541 * Linker script input section filespecs may now specify a file within an
542 archive by writing "archive:file".
543
544 * The --sort-common switch now has an optional argument which specifies the
545 direction of sorting.
546
547 * The M68K linker now supports multiple GOT generation schemes controlled via
548 the --got=<type> command-line option.
549
550 * The ARM EABI linker will now generate stubs for function calls to symbols
551 that are too far away. The placement of the stubs is controlled by a new
552 linker command-line option: --stub-group-size=N.
553
554 Changes in 2.18:
555
556 * Linker sources now released under version 3 of the GNU General Public
557 License.
558
559 * ELF: New --build-id option to generate a unique per-binary identifier
560 embedded in a note section.
561
562 * Added support for National Semicondutor CompactRISC (ie CR16) target.
563
564 * -l:foo now searches the library path for a filename called foo,
565 without converting it to libfoo.a or libfoo.so.
566
567 * Add a new command-line option '--default-script=FILE' or '-dT FILE'
568 which specifies a replacement for the built in, default linker
569 script.
570
571 * ELF: Add -Bsymbolic-functions, --dynamic-list-cpp-new, which puts C++
572 operator new and delete on the dynamic list, and --dynamic-list-data,
573 builtin list for --dynamic-list, which puts global data symbols on the
574 dynamic list.
575
576 * Add support for x86_64 PE+ target.
577
578 * Add support for Score target.
579
580 * ELF: Add --dynamic-list option to specify a list of global symbols
581 whose references shouldn't be bound to the definition within the
582 shared library, or a list of symbols which should be added to the
583 symbol table in the executable.
584
585 * The default output section LMA has changed for allocatable sections from
586 being equal to VMA, to keeping the difference between LMA and VMA the same as
587 the previous output section in the same region. This is a more useful
588 default when using overlays and other cases where you specify an LMA
589 differing from the VMA for some sections.
590
591 * New switch: --print-gc-sections to list any sections removed by garabge
592 collection.
593
594 * ARM: Added --vfp11-denorm-fix option to work around an erratum in current
595 VFP11 coprocessors.
596
597 Changes in 2.17:
598
599 * Support for the Infineon XC16X has been added by KPIT Cummins Infosystems.
600
601 * Modify the Linux linker search order to better match ld.so search order.
602 Look for DT_NEEDED libraries in paths specified by ld.so.conf before
603 searching the default directories, rather than vice versa.
604 Use $prefix/etc/ld.so.conf if it exists, otherwise /etc/ld.so.conf.
605
606 * PE-COFF: Forward exports from DLL's can now be specified in .def files
607 passed directly to ld.
608
609 * Support for the Z80 processor family has been added.
610
611 * Add support for the "@<file>" syntax to the command line, so that extra
612 switches can be read from <file>.
613
614 Changes in 2.16:
615
616 * Support for the R_ARM_V4BX relocation as defined in the ARM AAELF
617 specification has been added via the --fix-v4bx command-line option.
618
619 * New linker script construct AS_NEEDED(), which sets the --as-needed flag
620 for input files listed inside of it.
621
622 * A new command-line option, --sysroot, can be used to override the
623 default sysroot location. It only applies to toolchains that were
624 configured using --with-sysroot.
625
626 * New linker script functions: ORIGIN() and LENGTH() which return information
627 about a specified memory region.
628
629 * Port to MAXQ processor contributed by HCL Tech.
630
631 * Added SEGMENT_START to the linker script language to permit the user to
632 override the base address for a segment from the command-line.
633
634 * ELF: --warn-shared-textrel option to warn if adding a DT_TEXTREL to a shared
635 object.
636
637 * Added SORT_BY_NAME and SORT_BY_ALIGNMENT to the linker script
638 language to permit sorting sections by section name or section
639 maximum alignment.
640
641 * Added a new linker command-line switch, --sort-section name|alignment,
642 to sort sections by section name or maximum alignment.
643
644 * ELF: --add-needed/--no-add-needed options to control if a DT_NEEDED tag
645 should be added when a shared library comes from DT_NEEDED tags.
646
647 * Support for the crx-elf target added.
648
649 * Support for the sh-symbianelf target added.
650
651 * A new linker command-line switch has been added which allows the hash table
652 size to be set to a suitable prime value near to its argument. This switch
653 is --hash-size=<NUMBER>. Also if the switch --reduce-memory-overheads is
654 used, and --hash-size has not been used, then the default value will be set
655 to 1021.
656
657 * Linker map files are now generated with an O(N) algorithm for finding symbols
658 that are defined in each section. This uses about 40% more memory for
659 symbols than the old O(N^2) algorithm. You can use the new
660 --reduce-memory-overheads option to select the old algorithm; this option
661 might also be used in the future to select similar tradeoffs.
662
663 Changes in 2.15:
664
665 * ELF: --as-needed/--no-as-needed options to control if a DT_NEEDED tag should
666 be added only when a shared library is referenced.
667
668 * PE: --large-address-aware option to indicate executables support virtual
669 addresses greater than 2 gigabytes.
670
671 * DWARF 2 support for i386pe added.
672
673 * The linker script operator DEFINED() will now yield 1 only for a symbol that
674 is defined before the statement where DEFINED is used.
675
676 * The MIPS --embedded-relocs (used to embed relocations into binaries for
677 Embedded-PIC code) is deprecated and will be removed in a future release.
678
679 * cr16c support added by NSC.
680
681 * m32r Linux (ELF) support added by Renesas.
682
683 * Improved linker's handling of unresolved symbols. The switch
684 --unresolved-symbols=<method> has been added to tell the linker when it
685 should report them and the switch --warn-unresolved-symbols has been added to
686 make reports be issued as warning messages rather than errors.
687
688 Changes in 2.14:
689
690 * Added support for Xtensa architecture.
691
692 * Added --with-sysroot configure switch to specify a target system root, for
693 linking against a target filesystem image.
694
695 * Added --accept-unknown-linker-format to restore old linker behaviour (pre
696 2.14) of silently accepting and linking in any files in an unknown binary
697 file format.
698
699 * Added --no-omagic to undo the effects of the -N option.
700
701 * Support for Texas Instruments TMS320C4x and TMS320C3x series of
702 DSP's contributed by Michael Hayes and Svein E. Seldal.
703
704 * Added --with-lib-path configure switch to specify default value for
705 LIB_PATH.
706
707 * ARM port to QNX operating system added by Graeme Peterson.
708
709 * IP2K support added by Denis Chertykov.
710
711 Changes in 2.13:
712
713 * Support for the Fujitsu FRV architecture added by Red Hat. Models for FR400
714 and FR500 included.
715
716 Changes in version 2.13:
717
718 * DEC VAX ELF support, by Matt Thomas.
719
720 Changes in version 2.12:
721
722 * Support for Don Knuth's MMIX, by Hans-Peter Nilsson.
723
724 * Support for the OpenRISC 32-bit embedded processor by OpenCores.
725
726 * Support for -z nocopyreloc in the x86 ELF linker, which disables
727 production of copy relocs. Warning: using this option may result in
728 non-sharable applications.
729
730 * Support for -z combreloc in the ELF linker, which puts dynamic
731 relocations against the same symbol together, so that dynamic linker
732 can use an one-entry symbol lookup cache.
733
734 * Support for ELF SHF_MERGE section merging, by Jakub Jelinek.
735
736 Changes in version 2.11:
737
738 * Support for AMD x86-64 architecture, by Jan Hubicka, SuSE Labs.
739
740 * Support added for eliminating duplicate DWARF2 debug information by
741 having the compiler generate the information in sections called
742 .gnu.linkonce.wi.XXXX where XXXX is a checksum for the contents. The
743 linker then merges these sections together into the normal .debug_info
744 section.
745
746 * The native ELF linker now searches the directories in DT_RUNPATH or
747 DT_RPATH of a shared library for shared libraries needed by it.
748
749 * TI C54x support, by Timothy Wall.
750
751 * Added command-line switch --section-start to set the start address of any
752 specified section.
753
754 * Added ability to emit full relocation information in linked executables,
755 enabled by --emit-relocs. Some post-linkage optimization tools need
756 this information in order to be able to correctly identify and perform
757 symbol relative addressing in the event of changes in section contents
758 (instructions being added or deleted, extending data sections, etc.)
759
760 * Support for i860, by Jason Eckhardt (preliminary, alpha quality).
761
762 * Support for CRIS (Axis Communications ETRAX series).
763
764 * Support for PDP-11 and 2.11BSD a.out format, by Lars Brinkhoff.
765
766 Changes in version 2.10:
767
768 * Added AT> to the linker script language to allow load-time allocation of
769 sections into regions.
770
771 * Added garbage collection of unused sections, enabled by --gc-sections.
772 It does require a bit of backend support; currently implemented are
773 arm-elf, avr-elf, d10v-elf, fr30-elf, i386-elf, m32r-elf, m68k-elf,
774 mcore-elf, mips-elf, mn10300-elf, ppc-elf, sh-elf, sparc-elf, and v850-elf.
775 Others will ignore the option.
776
777 * Added SORT to the linker script language to permit sorting sections by file
778 name or section name.
779
780 * Added EXTERN to the linker script language as an equivalent to the -u
781 command-line option.
782
783 * Added ASSERT to the linker script language.
784
785 * Added EXCLUDE_FILE to the linker script language for further control over
786 wildcard file names.
787
788 * Added -O option to optimize linker output (as of this writing, this only
789 affects ELF shared library generation).
790
791 * The -e option now accepts a number as well as a symbol name.
792
793 * Added --no-undefined option to disallow undefined symbols when creating a
794 shared library.
795
796 * The linker now issues a warning, not an error, for an undefined symbol when
797 using -Bsymbolic; use the new --no-undefined option to get the old
798 behaviour.
799
800 * Added --demangle and --no-demangle options.
801
802 Changes in version 2.9:
803
804 * Added SQUAD to the linker script language.
805
806 * New option --no-warn-mismatch.
807
808 * The MEMORY command now parses the attributes to determine where sections that
809 are not placed in a specific memory region are placed.
810
811 Changes in version 2.8:
812
813 * Linker scripts may now contain shell wildcard characters for file and section
814 names.
815
816 * The linker now supports symbol versions in ELF.
817
818 * The NOCROSSREFS command was added to the linker script language.
819
820 * The LOADADDR expression was added to the linker script language.
821
822 * MAX and MIN functions were added to the linker script language.
823
824 * The OVERLAY construct was added to the linker script language.
825
826 * New option --warn-section-align to warn when the address of an output section
827 changes due to alignment of an input section.
828
829 * New options --filter/-F and --auxiliary/-f.
830
831 Changes in version 2.7:
832
833 * New option --cref to print out a cross reference table.
834
835 * New option --wrap SYMBOL.
836
837 * New option --no-whole-archive, to turn off the effect of --whole-archive.
838
839 * Input sections assigned to the output section /DISCARD/ in the linker script
840 are not included in the output file.
841
842 * The SunOS and ELF linkers now merge stabs debugging information which uses
843 the N_BINCL and N_EINCL stab types. This reduces the amount of debugging
844 information generated.
845
846 Changes in version 2.6:
847
848 * When an ELF section name is representable as a C identifier (this is not true
849 of most ELF section names), the linker will automatically define symbols
850 __start_SECNAME and __stop_SECNAME, where SECNAME is the section name, at the
851 beginning and the end of the section. This is used by glibc.
852
853 Addendum: Current versions of the linker (at least for version 2.18 onwards
854 and possibly much earlier as well) place two restrictions on this feature: The
855 symbols are only implemented for orphaned sections, not for explicitly placed
856 sections and they are PROVIDEd rather than being defined.
857
858 * When an ELF section named .gnu.warning is encountered in an input file, the
859 contents of the section are displayed as an error message, and the section is
860 not copied into the output file. This is used by glibc.
861
862 * When an ELF section named .gnu.warning.SYMBOL is encountered in an input
863 file, and the symbol SYMBOL is referenced by some object file, the contents of
864 the section are displayed as an error message. The section is not copied into
865 the output file, unless doing a relocatable or shared link. This is used by
866 glibc.
867
868 * New options -split-by-reloc and -split-by-file.
869
870 * The linker now supports linking PIC compiled code on SPARC SunOS. It can
871 also create SPARC SunOS shared libraries, and, like the native SunOS linker,
872 will do so whenever there is an undefined symbol in the link and neither the -e
873 nor the -r option was used.
874
875 * The -rpath option may be used on SunOS to set the list of directories to be
876 searched at run time. This overrides the default of building the list from the
877 -L options.
878
879 * The COFF linker now combines debugging information for structs, unions, and
880 enums, so that even if the same type is defined in multiple input files it will
881 only be defined once in the output file. The --traditional-format switch will
882 prevent this optimization.
883
884 Changes in version 2.5:
885
886 * The linker now supports linking against SunOS shared libraries. It still can
887 not link SunOS PIC (Position Independent Code) files, so it can not be used to
888 generate shared libraries.
889
890 * The linker now supports linking against ELF shared libraries for the i386
891 (UnixWare) and SPARC (Solaris). It can also link ELF PIC files, and can be
892 used to generate shared libraries. Shared library generation is not well
893 tested; please report any problems encountered. The linker is now enabled for
894 Solaris again.
895
896 * Eric Youngdale has contributed Linux support code, including linking against
897 Linux a.out shared libraries. The linker produces Linux QMAGIC binaries.
898
899 * The ELF backend has been converted to the new linker code. To use the new
900 ELF linker, each particular target requires a relocation function. So far,
901 this function has been written for i386 (UnixWare), SPARC (Solaris) MIPS (Irix
902 5), and HPPA ELF targets.
903
904 * The -( (--start-group) and -) (--end-group) options have been added to
905 support searching a group of archives as though they were a single archive.
906 This can also be used in a linker script, as GROUP ( files ).
907
908 * When a file is named on the command line, and the linker does not recognize
909 it as an object file, the linker will now treat the file as a linker script
910 file. A linker script named in this way augments, but does not replace, the
911 default linker script.
912
913 * The -warn-once option was added. It causes the linker to only warn once per
914 undefined symbol, rather than once per reference.
915
916 * The COFF backend has been converted to the new linker code. As with ELF, to
917 use the new linker, each particular target requires a relocation function. So
918 far, this function has been written for the i386, m68k, a29k and SH targets.
919
920 * The -V flag was made a synonym for -v, for SVR4 compatibility. The old -V
921 behaviour is available via --verbose.
922
923 Changes in version 2.4:
924
925 * New linker code, by Steve Chamberlain and Ian Taylor. For a.out and ecoff
926 formats (so far), this should result in considerable savings in time
927 and memory used while linking; slightly poorer performance than
928 before for formats not converted yet.
929
930 * Command-line parsing is no longer done with flex. This means
931 oddball characters in filenames won't get treated as argument
932 separators.
933
934 * HP-PA ELF support, by Jeff Law. (No SOM support yet.)
935
936 * Mach i386 support, by David Mackenzie.
937
938 * Irix 4 shared libraries are now supported (Irix 5 uses ELF, and ELF shared
939 libraries are not yet supported).
940
941 * COFF shared libraries (as on SCO) should work as well.
942
943 * The linker is disabled for Solaris. (Actually, it was in 2.3 also, I just
944 forgot to note it.) Some of their C library routines don't work when
945 statically linked, and the GNU linker doesn't support dynamic linking yet.
946
947 Changes in version 2.3:
948
949 * Weak symbols are now supported.
950
951 * ELF support has been added. The linker has been bootstrapped on
952 UnixWare and Solaris.
953
954 * Alpha OSF/1 support has been added (non dynamic linking only).
955
956 Changes in version 2.2:
957
958 * The `bfd' library has been updated to reduce a.out-format string
959 table size. The effect of this is that files linked from many input
960 files with duplicate symbols (`-g' debugging records, or identical
961 static symbols) should be much smaller.
962
963 Changes in version 2.1:
964
965 * The ld -ySYMBOL flag (to trace references to SYMBOL) is now implemented.
966
967 * There is now support for writing ECOFF files, so ld and the
968 other utilities should work on Risc/Ultrix and Irix.
969
970 \f
971 Copyright (C) 2012-2023 Free Software Foundation, Inc.
972
973 Copying and distribution of this file, with or without modification,
974 are permitted in any medium without royalty provided the copyright
975 notice and this notice are preserved.
976
977 Local variables:
978 fill-column: 79
979 End: