1-*- text -*- 2 3Changes in 2.37: 4 5* arm-symbianelf support removed. 6 7* Add -z report-relative-reloc to x86 ELF linker to report dynamic 8 relative relocations. 9 10* Add -z start-stop-gc to disable special treatment of __start_*/__stop_* 11 references when --gc-sections. 12 13* Add -Bno-symbolic to cancel -Bsymbolic and -Bsymbolic-functions. 14 15Changes in 2.36: 16 17* Add libdep plugin, for linking dependencies of static libraries that 18 were recorded by ar in the __.LIBDEP archive member. 19 20* Add --error-handling-script=<NAME> command line option to allow a helper 21 script to be invoked when an undefined symbol or a missing library is 22 encountered. This option can be suppressed via the configure time 23 switch: --enable-error-handling-script=no. 24 25* Add -z lam-u48 to x86-64 ELF linker to generate LAM_U48 property. 26 27* Add -z lam-u57 to x86-64 ELF linker to enerate LAM_U57 property. 28 29* Add -z lam-u48-report=[none|warning|error] to report missing LAM_U48 30 property. 31 32* Add -z lam-u57-report=[none|warning|error] to report missing LAM_U57 33 property. 34 35* Add -z lam-report=[none|warning|error] to report missing LAM_U48 and 36 LAM_U57 properties. 37 38* Add -z x86-64-{baseline|v[234]} to the x86 ELF linker to mark 39 x86-64-{baseline|v[234]} ISA level as needed. 40 41* Add -z unique-symbol to avoid duplicated local symbol names. 42 43* The creation of PE format DLLs now defaults to using a more secure set of DLL 44 characteristics. 45 46* The linker now deduplicates the types in .ctf sections. The new 47 command-line option --ctf-share-types describes how to do this: 48 its default value, share-unconflicted, produces the most compact 49 output. 50 51* The linker now omits the "variable section" from .ctf sections by 52 default, saving space. This is almost certainly what you want 53 unless you are working on a project that has its own analogue 54 of symbol tables that are not reflected in the ELF symtabs. 55 56* Add support for the SHF_GNU_RETAIN ELF section flag. 57 This flag specifies that the section should not be garbage collected by the 58 linker. 59 60Changes in 2.35: 61 62* X86 NaCl target support is removed. 63 64* Add ELF linker command-line options, --export-dynamic-symbol and 65 --export-dynamic-symbol-list, to make symbols dynamic. 66 67* Add a configure option, --enable-textrel-check=[no|yes|warning|error], 68 to decide what ELF linker should do by default with DT_TEXTREL in an 69 executable or shared library. Default to yes for Linux/x86 targets. 70 71* The -Map=<filename> command line option has been extended so that if 72 <filename> is a directory then <filename>/<output-filename>.map will be 73 created. 74 75* Add a command-line option for ELF linker, --warn-textrel, to warn that 76 DT_TEXTREL is set in a position-independent executable or shared object. 77 78* Add command-line options --enable-non-contiguous-regions and 79 --enable-non-contiguous-regions-warnings. 80 81* Add command-line option --imagic for the pdp11-aout target to output format 82 IMAGIC (0411) for separate instruction and data spaces, and change the 83 default format option for pdp11-aout to be --omagic. 84 85* Relative pathnames in INPUT() and GROUP() directives in linker scripts are 86 searched relative to the directory of the linker script before other search 87 paths. 88 89* Add ELF linker command-line option `-z start-stop-visibility=...' to control 90 the visibility of synthetic `__start_SECNAME` and `__stop_SECNAME` symbols. 91 92* Add command-line option --dependency-file to write a Make-style dependency 93 file listing the input files consulted by the linker, like the files written 94 by the compiler's -M -MP options. 95 96Changes in 2.34: 97 98* The ld check for "PHDR segment not covered by LOAD segment" is more 99 effective, catching cases that were wrongly allowed by previous versions of 100 ld. If you see this error it is likely you are linking with a bad linker 101 script or the binary you are building is not intended to be loaded by a 102 dynamic loader. In the latter case --no-dynamic-linker is appropriate. 103 104* cr16c support removed. 105 106* Add support for z80-elf. 107 108* Add support for relocation of each byte or word of multibyte value to Z80 109 targets. 110 111* Add support for Zilog eZ80 (both ADL and Z80 mode) and Zilog Z180 CPUs. 112 113Changes in 2.33: 114 115* Add command-line option --no-print-map-discarded. 116 117* The Cortex-A53 Erratum 843419 workaround now supports a choice of which 118 workaround to use. The option --fix-cortex-a53-843419 now takes an 119 optional argument --fix-cortex-a53-843419[=full|adr|adrp] which can be 120 used to force a particular workaround to be used. See --help for AArch64 121 for more details. 122 123* Add target handlers for AArch64 for ELF GNU program properties. 124 125* Add support for GNU_PROPERTY_AARCH64_FEATURE_1_BTI in ELF GNU program 126 properties in the AArch64 ELF linker. 127 128* Add support for GNU_PROPERTY_AARCH64_FEATURE_1_PAC in ELF GNU program 129 properties in the AArch64 ELF linker. 130 131* Add -z force-bti for AArch64 to enable GNU_PROPERTY_AARCH64_FEATURE_1_BTI 132 on output while warning about missing GNU_PROPERTY_AARCH64_FEATURE_1_BTI 133 on inputs and use PLTs protected with BTI. 134 135* Add -z pac-plt for AArch64 to pick PAC enabled PLTs. 136 137Changes in 2.32: 138 139* Report property change in linker map file when merging GNU properties. 140 141* Add support for the C-SKY processor series. 142 143* -t now doesn't report members within archives, unless -t is given twice. 144 A single -t is now more useful when generating a list of files that should be 145 packaged for a linker bug report. For example: 146 gcc hello.c -save-temps -Wl,-t | xargs realpath | sort | uniq > files 147 tar cJf test.tar.xz `cat files` 148 149Changes in 2.31: 150 151* Speed up direct linking with DLLs for Cygwin and Mingw targets. 152 153* Add a configure option --enable-separate-code to decide whether 154 -z separate-code should be enabled in ELF linker by default. Default 155 to yes for Linux/x86 targets. Note that -z separate-code can increase 156 disk and memory size. 157 158Changes in 2.30: 159 160* Add -z separate-code to generate separate code PT_LOAD segment. 161 162* Add "-z undefs" command-line option as the inverse of the "-z defs" option. 163 164* Add -z globalaudit command-line option to force audit libraries to be run 165 for every dynamic object loaded by an executable - provided that the loader 166 supports this functionality. 167 168* Tighten linker script grammar around file name specifiers to prevent the use 169 of SORT_BY_ALIGNMENT and SORT_BY_INIT_PRIORITY on filenames. These would 170 previously be accepted but had no effect. 171 172* The EXCLUDE_FILE directive can now be placed within any SORT_* directive 173 within input section lists. 174 175Changes in 2.29: 176 177* Support for -z shstk in the x86 ELF linker to generate 178 GNU_PROPERTY_X86_FEATURE_1_SHSTK in ELF GNU program properties. 179 180* Add support for GNU_PROPERTY_X86_FEATURE_1_SHSTK in ELF GNU program 181 properties in the x86 ELF linker. 182 183* Add support for GNU_PROPERTY_X86_FEATURE_1_IBT in ELF GNU program 184 properties in the x86 ELF linker. 185 186* Support for -z ibtplt in the x86 ELF linker to generate IBT-enabled 187 PLT. 188 189* Support for -z ibt in the x86 ELF linker to generate IBT-enabled 190 PLT as well as GNU_PROPERTY_X86_FEATURE_1_IBT in ELF GNU program 191 properties. 192 193* Add support for ELF SHF_GNU_MBIND and PT_GNU_MBIND_XXX. 194 195* Add support for ELF GNU program properties. 196 197* Add support for the Texas Instruments PRU processor. 198 199* When configuring for arc*-*-linux* targets the default linker emulation will 200 change if --with-cpu=nps400 is used at configure time. 201 202* Improve assignment of LMAs to orphan sections in some edge cases where a 203 mixture of both AT>LMA_REGION and AT(LMA) are used. 204 205* Orphan sections placed after an empty section that has an AT(LMA) will now 206 take an load memory address starting from LMA. 207 208* Section groups can now be resolved (the group deleted and the group members 209 placed like normal sections) at partial link time either using the new linker 210 option --force-group-allocation or by placing FORCE_GROUP_ALLOCATION into the 211 linker script. 212 213Changes in 2.28: 214 215* The EXCLUDE_FILE linker script construct can now be applied outside of the 216 section list in order for the exclusions to apply over all input sections in 217 the list. 218 219* Add support for the RISC-V architecture. 220 221* The command-line option --no-eh-frame-hdr can now be used in ELF based 222 linkers to disable the automatic generation of .eh_frame_hdr sections. 223 224* Add --in-implib=<infile> to the ARM linker to enable specifying a set of 225 Secure Gateway veneers that must exist in the output import library specified 226 by --out-implib=<outfile> and the address they must have. As such, 227 --in-implib is only supported in combination with --cmse-implib. 228 229* Extended the --out-implib=<file> option, previously restricted to x86 PE 230 targets, to any ELF based target. This allows the generation of an import 231 library for an ELF executable, which can then be used by another application 232 to link against the executable. 233 234Changes in 2.27: 235 236* Add a configure option --enable-relro to decide whether -z relro should 237 be enabled in ELF linker by default. Default to yes for all Linux 238 targets except FRV, HPPA, IA64 and MIPS. Note that -z relro can increase 239 disk and memory size. 240 241* Support for -z noreloc-overflow in the x86-64 ELF linker to disable 242 relocation overflow check. 243 244* Add -z common/-z nocommon options for ELF targets to control whether to 245 convert common symbols to the STT_COMMON type during a relocatable link. 246 247* Support for -z nodynamic-undefined-weak in the x86 ELF linker, which 248 avoids dynamic relocations against undefined weak symbols in executable. 249 250* The NOCROSSREFSTO command was added to the linker script language. 251 252* Add --no-apply-dynamic-relocs to the AArch64 linker to do not apply link-time 253 values for dynamic relocations. 254 255Changes in 2.26: 256 257* Add --fix-stm32l4xx-629360 to the ARM linker to enable a link-time 258 workaround for a bug in the bus matrix / memory controller for some of 259 the STM32 Cortex-M4 based products (STM32L4xx) 260 261* Add a configure option --enable-compressed-debug-sections={all,ld} to 262 decide whether DWARF debug sections should be compressed by default. 263 264* Add support for the ARC EM/HS, and ARC600/700 architectures. 265 266* Experimental support for linker garbage collection (--gc-sections) 267 has been enabled for COFF and PE based targets. 268 269* New command-line option for ELF targets to compress DWARF debug 270 sections, --compress-debug-sections=[none|zlib|zlib-gnu|zlib-gabi]. 271 272* New command-line option, --orphan-handling=[place|warn|error|discard], to 273 adjust how orphan sections are handled. The default is 'place' which gives 274 the current behaviour, 'warn' and 'error' issue a warning or error 275 respectively when orphan sections are found, and 'discard' will discard all 276 orphan sections. 277 278* Add support for LLVM plugin. 279 280* Add --print-memory-usage option to report memory blocks usage. 281 282* Add --require-defined option, it's like --undefined except the new symbol 283 must be defined by the end of the link. 284 285Changes in 2.25: 286 287* PE binaries now once again contain real timestamps by default. To disable 288 the inclusion of a timestamp in a PE binary, use the --no-insert-timestamp 289 command-line option. 290 291* Replace support for openrisc and or32 with support for or1k. 292 293* Add support for the --build-id command-line option to COFF based targets. 294 295* x86/x86_64 pe-coff now supports the --build-id option. 296 297* Add support for the Andes NDS32. 298 299Changes in 2.24: 300 301* Add LOG2CEIL() builtin function to the linker script language 302 303* Add support for the Texas Instruments MSP430X processor. 304 305* Add support for Altera Nios II. 306 307* Add support for the V850E3V5 architecture. 308 309* Add support for the Imagination Technologies Meta processor. 310 311* --enable-new-dtags no longer generates old dtags in addition to new dtags. 312 313* Remove linker support for MIPS ECOFF targets. 314 315* Add ALIGN_WITH_INPUT to the linker script language to force the alignment of 316 an output section to use the maximum alignment of all its input sections. 317 318Changes in 2.23: 319 320* Enable compressed debug section feature for x86/x86_64 pe-coff. 321 322* Add support for the 64-bit ARM architecture: AArch64. 323 324* Added SORT_NONE to the linker script language to disable section sorting. 325 326* Add a linker-provided symbol when producing ELF output, '__ehdr_start' 327 to point to the ELF file header (and nearby program headers) in the 328 program's memory image. 329 330* Add support for S12X processor. 331 332* Add support for the VLE extension to the PowerPC architecture. 333 334* Add support for the Freescale XGATE architecture. 335 336* Add option -f FILE on AIX (for response file). 337 338* Add support for the Renesas RL78 architecture. 339 340* Add support for the Adapteva EPIPHANY architecture. 341 342Changes in 2.22: 343 344* --copy-dt-needed-entries is no longer enabled by default. Instead 345 --no-copy-dt-needed-entries is the default. 346 347* INPUT_SECTION_FLAGS has been added to the linker script language 348 to allow selection of input sections by section header section flags. 349 350* Add support for the Tilera TILEPro and TILE-Gx architectures. 351 352* Added SORT_BY_INIT_PRIORITY to the linker script language to permit 353 sorting sections by numerical value of the GCC init_priority attribute 354 encoded in the section name. 355 356Changes in 2.21: 357 358* Linker script expression evaluation is somewhat more sane. This may 359 break scripts that depend on quirks of the old expression evaluation. 360 361* Turn off underscoring for x86_64 PE+-COFF targets. For old behavior the 362 option --enable-leading-mingw64-underscores can be used on configure of 363 bfd. 364 365* Add support for the TMS320C6000 (TI C6X) processor family. 366 367* --add-needed renamed to --copy-dt-needed-entries in order to avoid confusion 368 with --as-needed option. 369 370* Extend .def file syntax by '== <ID>' for imports and exports. This allows 371 to alias the import/export table name written in PE image. 372 373* Add --exclude-all-symbols option to PE based linkers. This prevents all 374 symbols from automatically being exported. 375 376* Add support for the Renesas RX processor. 377 378* Add support for alpha-vms target. 379 380Changes in 2.20: 381 382* GNU/Linux targets now support the STB_GNU_UNIQUE symbol binding. This is a 383 GNU extension to the standard set of ELF symbol bindings. The binding will 384 be passed on to the dynamic linker which will make sure that in the entire 385 process there is just one symbol with the given name and type in use. 386 387* PE targets now support a GNU extension to allow the alignment of common 388 common symbols to be specified. This support uses custom options in 389 the .drectve section, which will be disregarded by the native tools. 390 391* PE targets now add primitive support for ELF version scripts; symbols 392 are not versioned, but the local and global symbol visibility directives 393 are respected when filtering symbols in auto-export mode. 394 395* New option --no-export-dynamic to undo the effect of the -E and 396 --export-dynamic options. 397 398* ELF: --warn-alternate-em option to warn if an object has alternate 399 ELF machine code. 400 401* New script function REGION_ALIAS to add alias names to memory regions. 402 403* PE targets no longer make use of the long section names PE extension to 404 the COFF format when generating executable images, by default. The old 405 (slightly non-conformant) behaviour can still be invoked by using the 406 new '--enable-long-section-names' command-line option. It is also enabled 407 automatically in the presence of un-stripped debug information, as GDB 408 needs to be able to find the debug info sections by their full names. 409 410* For GNU/Linux systems the linker will now avoid processing any relocations 411 made against symbols of the STT_GNU_IFUNC type and instead emit them into 412 the resulting binary for processing by the loader. 413 414* --as-needed now links in a dynamic library if it satisfies undefined 415 symbols in regular objects, or in other dynamic libraries. In the 416 latter case the library is not linked if it is found in a DT_NEEDED 417 entry of one of the libraries already linked. 418 419* Add a new command-line option, -Ttext-segment ADDR, for ELF targets 420 to set the address of the first byte of the text segment. 421 422* Add support for Sunplus score architecture. 423 424* Add new option --use-nul-prefixed-import-tables to ld for PE targets to 425 allow fallback to old import table generation with null element prefix. 426 427* Windows PE systems now support a new --exclude-modules-for-implib option, 428 allowing users to partition object files and archive members between a DLL 429 and its associated import library as they are generated during linking. 430 431* Add support for Lattice Mico32 (lm32) architecture. 432 433* Add CR16 ELF --embedded-relocs (used to embedded relocations into binaries 434 for Embedded-PIC code) option. 435 436* Add to the PE/PE+ targets the support of two different kinds of 437 pseudo-relocations. They can be selected by the switches 438 --enable-runtime-pseudo-reloc-v1 and --enable-runtime-pseudo-reloc-v2. 439 For the switch --enable-runtime-pseudo-reloc it uses for 32-bit 440 runtime pseudo relocation version one, for 64-bit the version two. 441 442Changes in 2.19: 443 444* Linker scripts support a new INSERT command that makes it easier to 445 augment the default script. 446 447* Linker script input section filespecs may now specify a file within an 448 archive by writing "archive:file". 449 450* The --sort-common switch now has an optional argument which specifies the 451 direction of sorting. 452 453* The M68K linker now supports multiple GOT generation schemes controlled via 454 the --got=<type> command-line option. 455 456* The ARM EABI linker will now generate stubs for function calls to symbols 457 that are too far away. The placement of the stubs is controlled by a new 458 linker command-line option: --stub-group-size=N. 459 460Changes in 2.18: 461 462* Linker sources now released under version 3 of the GNU General Public 463 License. 464 465* ELF: New --build-id option to generate a unique per-binary identifier 466 embedded in a note section. 467 468* Added support for National Semicondutor CompactRISC (ie CR16) target. 469 470* -l:foo now searches the library path for a filename called foo, 471 without converting it to libfoo.a or libfoo.so. 472 473* Add a new command-line option '--default-script=FILE' or '-dT FILE' 474 which specifies a replacement for the built in, default linker 475 script. 476 477* ELF: Add -Bsymbolic-functions, --dynamic-list-cpp-new, which puts C++ 478 operator new and delete on the dynamic list, and --dynamic-list-data, 479 builtin list for --dynamic-list, which puts global data symbols on the 480 dynamic list. 481 482* Add support for x86_64 PE+ target. 483 484* Add support for Score target. 485 486* ELF: Add --dynamic-list option to specify a list of global symbols 487 whose references shouldn't be bound to the definition within the 488 shared library, or a list of symbols which should be added to the 489 symbol table in the executable. 490 491* The default output section LMA has changed for allocatable sections from 492 being equal to VMA, to keeping the difference between LMA and VMA the same as 493 the previous output section in the same region. This is a more useful 494 default when using overlays and other cases where you specify an LMA 495 differing from the VMA for some sections. 496 497* New switch: --print-gc-sections to list any sections removed by garabge 498 collection. 499 500* ARM: Added --vfp11-denorm-fix option to work around an erratum in current 501 VFP11 coprocessors. 502 503Changes in 2.17: 504 505* Support for the Infineon XC16X has been added by KPIT Cummins Infosystems. 506 507* Modify the Linux linker search order to better match ld.so search order. 508 Look for DT_NEEDED libraries in paths specified by ld.so.conf before 509 searching the default directories, rather than vice versa. 510 Use $prefix/etc/ld.so.conf if it exists, otherwise /etc/ld.so.conf. 511 512* PE-COFF: Forward exports from DLL's can now be specified in .def files 513 passed directly to ld. 514 515* Support for the Z80 processor family has been added. 516 517* Add support for the "@<file>" syntax to the command line, so that extra 518 switches can be read from <file>. 519 520Changes in 2.16: 521 522* Support for the R_ARM_V4BX relocation as defined in the ARM AAELF 523 specification has been added via the --fix-v4bx command-line option. 524 525* New linker script construct AS_NEEDED(), which sets the --as-needed flag 526 for input files listed inside of it. 527 528* A new command-line option, --sysroot, can be used to override the 529 default sysroot location. It only applies to toolchains that were 530 configured using --with-sysroot. 531 532* New linker script functions: ORIGIN() and LENGTH() which return information 533 about a specified memory region. 534 535* Port to MAXQ processor contributed by HCL Tech. 536 537* Added SEGMENT_START to the linker script language to permit the user to 538 override the base address for a segment from the command-line. 539 540* ELF: --warn-shared-textrel option to warn if adding a DT_TEXTREL to a shared 541 object. 542 543* Added SORT_BY_NAME and SORT_BY_ALIGNMENT to the linker script 544 language to permit sorting sections by section name or section 545 maximum alignment. 546 547* Added a new linker command-line switch, --sort-section name|alignment, 548 to sort sections by section name or maximum alignment. 549 550* ELF: --add-needed/--no-add-needed options to control if a DT_NEEDED tag 551 should be added when a shared library comes from DT_NEEDED tags. 552 553* Support for the crx-elf target added. 554 555* Support for the sh-symbianelf target added. 556 557* A new linker command-line switch has been added which allows the hash table 558 size to be set to a suitable prime value near to its argument. This switch 559 is --hash-size=<NUMBER>. Also if the switch --reduce-memory-overheads is 560 used, and --hash-size has not been used, then the default value will be set 561 to 1021. 562 563* Linker map files are now generated with an O(N) algorithm for finding symbols 564 that are defined in each section. This uses about 40% more memory for 565 symbols than the old O(N^2) algorithm. You can use the new 566 --reduce-memory-overheads option to select the old algorithm; this option 567 might also be used in the future to select similar tradeoffs. 568 569Changes in 2.15: 570 571* ELF: --as-needed/--no-as-needed options to control if a DT_NEEDED tag should 572 be added only when a shared library is referenced. 573 574* PE: --large-address-aware option to indicate executables support virtual 575 addresses greater than 2 gigabytes. 576 577* DWARF 2 support for i386pe added. 578 579* The linker script operator DEFINED() will now yield 1 only for a symbol that 580 is defined before the statement where DEFINED is used. 581 582* The MIPS --embedded-relocs (used to embed relocations into binaries for 583 Embedded-PIC code) is deprecated and will be removed in a future release. 584 585* cr16c support added by NSC. 586 587* m32r Linux (ELF) support added by Renesas. 588 589* Improved linker's handling of unresolved symbols. The switch 590 --unresolved-symbols=<method> has been added to tell the linker when it 591 should report them and the switch --warn-unresolved-symbols has been added to 592 make reports be issued as warning messages rather than errors. 593 594Changes in 2.14: 595 596* Added support for Xtensa architecture. 597 598* Added --with-sysroot configure switch to specify a target system root, for 599 linking against a target filesystem image. 600 601* Added --accept-unknown-linker-format to restore old linker behaviour (pre 602 2.14) of silently accepting and linking in any files in an unknown binary 603 file format. 604 605* Added --no-omagic to undo the effects of the -N option. 606 607* Support for Texas Instruments TMS320C4x and TMS320C3x series of 608 DSP's contributed by Michael Hayes and Svein E. Seldal. 609 610* Added --with-lib-path configure switch to specify default value for 611 LIB_PATH. 612 613* ARM port to QNX operating system added by Graeme Peterson. 614 615* IP2K support added by Denis Chertykov. 616 617Changes in 2.13: 618 619* Support for the Fujitsu FRV architecture added by Red Hat. Models for FR400 620 and FR500 included. 621 622Changes in version 2.13: 623 624* DEC VAX ELF support, by Matt Thomas. 625 626Changes in version 2.12: 627 628* Support for Don Knuth's MMIX, by Hans-Peter Nilsson. 629 630* Support for the OpenRISC 32-bit embedded processor by OpenCores. 631 632* Support for -z nocopyreloc in the x86 ELF linker, which disables 633 production of copy relocs. Warning: using this option may result in 634 non-sharable applications. 635 636* Support for -z combreloc in the ELF linker, which puts dynamic 637 relocations against the same symbol together, so that dynamic linker 638 can use an one-entry symbol lookup cache. 639 640* Support for ELF SHF_MERGE section merging, by Jakub Jelinek. 641 642Changes in version 2.11: 643 644* Support for AMD x86-64 architecture, by Jan Hubicka, SuSE Labs. 645 646* Support added for eliminating duplicate DWARF2 debug information by 647 having the compiler generate the information in sections called 648 .gnu.linkonce.wi.XXXX where XXXX is a checksum for the contents. The 649 linker then merges these sections together into the normal .debug_info 650 section. 651 652* The native ELF linker now searches the directories in DT_RUNPATH or 653 DT_RPATH of a shared library for shared libraries needed by it. 654 655* TI C54x support, by Timothy Wall. 656 657* Added command-line switch --section-start to set the start address of any 658 specified section. 659 660* Added ability to emit full relocation information in linked executables, 661 enabled by --emit-relocs. Some post-linkage optimization tools need 662 this information in order to be able to correctly identify and perform 663 symbol relative addressing in the event of changes in section contents 664 (instructions being added or deleted, extending data sections, etc.) 665 666* Support for i860, by Jason Eckhardt (preliminary, alpha quality). 667 668* Support for CRIS (Axis Communications ETRAX series). 669 670* Support for PDP-11 and 2.11BSD a.out format, by Lars Brinkhoff. 671 672Changes in version 2.10: 673 674* Added AT> to the linker script language to allow load-time allocation of 675 sections into regions. 676 677* Added garbage collection of unused sections, enabled by --gc-sections. 678 It does require a bit of backend support; currently implemented are 679 arm-elf, avr-elf, d10v-elf, fr30-elf, i386-elf, m32r-elf, m68k-elf, 680 mcore-elf, mips-elf, mn10300-elf, ppc-elf, sh-elf, sparc-elf, and v850-elf. 681 Others will ignore the option. 682 683* Added SORT to the linker script language to permit sorting sections by file 684 name or section name. 685 686* Added EXTERN to the linker script language as an equivalent to the -u 687 command-line option. 688 689* Added ASSERT to the linker script language. 690 691* Added EXCLUDE_FILE to the linker script language for further control over 692 wildcard file names. 693 694* Added -O option to optimize linker output (as of this writing, this only 695 affects ELF shared library generation). 696 697* The -e option now accepts a number as well as a symbol name. 698 699* Added --no-undefined option to disallow undefined symbols when creating a 700 shared library. 701 702* The linker now issues a warning, not an error, for an undefined symbol when 703 using -Bsymbolic; use the new --no-undefined option to get the old 704 behaviour. 705 706* Added --demangle and --no-demangle options. 707 708Changes in version 2.9: 709 710* Added SQUAD to the linker script language. 711 712* New option --no-warn-mismatch. 713 714* The MEMORY command now parses the attributes to determine where sections that 715 are not placed in a specific memory region are placed. 716 717Changes in version 2.8: 718 719* Linker scripts may now contain shell wildcard characters for file and section 720 names. 721 722* The linker now supports symbol versions in ELF. 723 724* The NOCROSSREFS command was added to the linker script language. 725 726* The LOADADDR expression was added to the linker script language. 727 728* MAX and MIN functions were added to the linker script language. 729 730* The OVERLAY construct was added to the linker script language. 731 732* New option --warn-section-align to warn when the address of an output section 733 changes due to alignment of an input section. 734 735* New options --filter/-F and --auxiliary/-f. 736 737Changes in version 2.7: 738 739* New option --cref to print out a cross reference table. 740 741* New option --wrap SYMBOL. 742 743* New option --no-whole-archive, to turn off the effect of --whole-archive. 744 745* Input sections assigned to the output section /DISCARD/ in the linker script 746 are not included in the output file. 747 748* The SunOS and ELF linkers now merge stabs debugging information which uses 749 the N_BINCL and N_EINCL stab types. This reduces the amount of debugging 750 information generated. 751 752Changes in version 2.6: 753 754* When an ELF section name is representable as a C identifier (this is not true 755of most ELF section names), the linker will automatically define symbols 756__start_SECNAME and __stop_SECNAME, where SECNAME is the section name, at the 757beginning and the end of the section. This is used by glibc. 758 759 Addendum: Current versions of the linker (at least for version 2.18 onwards 760and possibly much earlier as well) place two restrictions on this feature: The 761symbols are only implemented for orphaned sections, not for explicitly placed 762sections and they are PROVIDEd rather than being defined. 763 764* When an ELF section named .gnu.warning is encountered in an input file, the 765contents of the section are displayed as an error message, and the section is 766not copied into the output file. This is used by glibc. 767 768* When an ELF section named .gnu.warning.SYMBOL is encountered in an input 769file, and the symbol SYMBOL is referenced by some object file, the contents of 770the section are displayed as an error message. The section is not copied into 771the output file, unless doing a relocatable or shared link. This is used by 772glibc. 773 774* New options -split-by-reloc and -split-by-file. 775 776* The linker now supports linking PIC compiled code on SPARC SunOS. It can 777also create SPARC SunOS shared libraries, and, like the native SunOS linker, 778will do so whenever there is an undefined symbol in the link and neither the -e 779nor the -r option was used. 780 781* The -rpath option may be used on SunOS to set the list of directories to be 782searched at run time. This overrides the default of building the list from the 783-L options. 784 785* The COFF linker now combines debugging information for structs, unions, and 786enums, so that even if the same type is defined in multiple input files it will 787only be defined once in the output file. The --traditional-format switch will 788prevent this optimization. 789 790Changes in version 2.5: 791 792* The linker now supports linking against SunOS shared libraries. It still can 793not link SunOS PIC (Position Independent Code) files, so it can not be used to 794generate shared libraries. 795 796* The linker now supports linking against ELF shared libraries for the i386 797(UnixWare) and SPARC (Solaris). It can also link ELF PIC files, and can be 798used to generate shared libraries. Shared library generation is not well 799tested; please report any problems encountered. The linker is now enabled for 800Solaris again. 801 802* Eric Youngdale has contributed Linux support code, including linking against 803Linux a.out shared libraries. The linker produces Linux QMAGIC binaries. 804 805* The ELF backend has been converted to the new linker code. To use the new 806ELF linker, each particular target requires a relocation function. So far, 807this function has been written for i386 (UnixWare), SPARC (Solaris) MIPS (Irix 8085), and HPPA ELF targets. 809 810* The -( (--start-group) and -) (--end-group) options have been added to 811support searching a group of archives as though they were a single archive. 812This can also be used in a linker script, as GROUP ( files ). 813 814* When a file is named on the command line, and the linker does not recognize 815it as an object file, the linker will now treat the file as a linker script 816file. A linker script named in this way augments, but does not replace, the 817default linker script. 818 819* The -warn-once option was added. It causes the linker to only warn once per 820undefined symbol, rather than once per reference. 821 822* The COFF backend has been converted to the new linker code. As with ELF, to 823use the new linker, each particular target requires a relocation function. So 824far, this function has been written for the i386, m68k, a29k and SH targets. 825 826* The -V flag was made a synonym for -v, for SVR4 compatibility. The old -V 827behaviour is available via --verbose. 828 829Changes in version 2.4: 830 831* New linker code, by Steve Chamberlain and Ian Taylor. For a.out and ecoff 832 formats (so far), this should result in considerable savings in time 833 and memory used while linking; slightly poorer performance than 834 before for formats not converted yet. 835 836* Command-line parsing is no longer done with flex. This means 837 oddball characters in filenames won't get treated as argument 838 separators. 839 840* HP-PA ELF support, by Jeff Law. (No SOM support yet.) 841 842* Mach i386 support, by David Mackenzie. 843 844* Irix 4 shared libraries are now supported (Irix 5 uses ELF, and ELF shared 845 libraries are not yet supported). 846 847* COFF shared libraries (as on SCO) should work as well. 848 849* The linker is disabled for Solaris. (Actually, it was in 2.3 also, I just 850 forgot to note it.) Some of their C library routines don't work when 851 statically linked, and the GNU linker doesn't support dynamic linking yet. 852 853Changes in version 2.3: 854 855* Weak symbols are now supported. 856 857* ELF support has been added. The linker has been bootstrapped on 858 UnixWare and Solaris. 859 860* Alpha OSF/1 support has been added (non dynamic linking only). 861 862Changes in version 2.2: 863 864* The `bfd' library has been updated to reduce a.out-format string 865 table size. The effect of this is that files linked from many input 866 files with duplicate symbols (`-g' debugging records, or identical 867 static symbols) should be much smaller. 868 869Changes in version 2.1: 870 871* The ld -ySYMBOL flag (to trace references to SYMBOL) is now implemented. 872 873* There is now support for writing ECOFF files, so ld and the 874 other utilities should work on Risc/Ultrix and Irix. 875 876 877Copyright (C) 2012-2021 Free Software Foundation, Inc. 878 879Copying and distribution of this file, with or without modification, 880are permitted in any medium without royalty provided the copyright 881notice and this notice are preserved. 882 883Local variables: 884fill-column: 79 885End: 886