1 -*- text -*- 2 3 Changes in 2.45: 4 5 * On s390 64-bit (s390x), generate SFrame stack trace information (.sframe) 6 for the linker generated .plt section. Enabled by default. Can be disabled 7 using linker option --no-ld-generated-unwind-info. 8 9 * All SFrame sections generated by the linker have the header flag 10 SFRAME_F_FDE_FUNC_START_PCREL set to indicate the new encoding for 11 sfde_func_start_address field in the SFrame section. Relocatable SFrame 12 links are now fixed. 13 14 ELF SFrame sections now have section type set to SHT_GNU_SFRAME. 15 16 * On RISC-V, add new PLT formats, and GNU property merge rules for zicfiss and 17 zicfilp extensions. 18 19 * The linker's --stats option can take an optional argument which if used is 20 interpreted as a filename into which resource usage information should be 21 stored. As an alternative mechanism the LD_STATS environment variable can 22 also be used to achieve the same results. Resource usage information for 23 various phases of the linking operation is now included in the report. 24 If a map file is being produced then the information is also included there. 25 The --no-stats option can be used to disable stat reporting, should it have 26 been enabled. 27 28 * Remove the linker -taso option for Alpha target, as Linux/Alpha kernel 29 support for 32-bit pointers has been removed. 30 31 * On avr, the default linker scripts now assert that the .progmem sections 32 don't extend past 0xffff since they are accessed by means of LPM. 33 For data in program memory that may be located past 0xffff, a .progmemx 34 section should be used. 35 36 * On s390, generate ".eh_frame" unwind information for the linker generated 37 .plt section. Enabled by default. Can be disabled using linker option 38 --no-ld-generated-unwind-info. 39 40 * On s390, add support for linker option --[no-]ld-generated-unwind-info. 41 42 * On LoongArch, linker relaxation time complexity is no longer quadratic with 43 respect to relocation counts. Linking time of large software should be 44 improved. 45 46 * On LoongArch, R_LARCH_32_PCREL records are now checked for overflow. 47 48 Changes in 2.44: 49 50 * Support for Nios II target has been removed, as this architecture has been 51 EOL'ed by Intel. 52 53 * The default maximum page size was changed from 16KiB to 64KiB for LoongArch. 54 55 * Add support for mixed LTO and non-LTO codes in relocatable output. 56 57 * Add --image-base=<ADDR> option to the ELF linker to behave the same 58 as -Ttext-segment for compatibility with LLD. 59 60 * Add a "--build-id=xx" option, if built with the xxhash library. This 61 produces a 128-bit hash, 2-4x faster than md5 or sha1. 62 63 * The ELF linker option --package-metadata supports percent-encoded and 64 %[string] encoded JSON payload now to ease passing around this option 65 without getting the JSON payload corrupted. 66 67 Changes in 2.43: 68 69 * Add support for LoongArch DT_RELR (compressed R_LARCH_RELATIVE). 70 71 * Put .got .got.plt in the relro to make it read-only after relocation. 72 73 * Add -z isa-level-report=[none|all|needed|used] to the x86 ELF linker 74 to report needed and used x86-64 ISA levels. 75 76 * Add --rosegment option which changes the -z separate-code option so that 77 only one read-only segment is created (instead of two). (The option name 78 is misleading, but it matches the name used by LLD and GOLD). 79 80 * Add --section-ordering-file <FILE> option to add extra mapping of input 81 sections to output sections. 82 83 * Add -plugin-save-temps to store plugin intermediate files permanently. 84 85 * Add -z memory-seal/-z nomemory-seal options to ELF linker to mark the 86 object to memory sealed. Also added --enable-memory-seal configure option 87 to enable the memory sealing by default. 88 89 Changes in 2.42: 90 91 * Add -z mark-plt/-z nomark-plt options to x86-64 ELF linker to mark PLT 92 entries with DT_X86_64_PLT, DT_X86_64_PLTSZ and DT_X86_64_PLTENT dynamic 93 tags. Also added --enable-mark-plt configure option to mark PLT entries 94 by default. 95 96 * Support Intel APX relocations. 97 98 * On RISC-V, add ld target option --[no-]check-uleb128. Should rebuild the 99 objects by binutils 2.42 and up if enabling the option and get warnings, 100 since the non-zero addend of SUB_ULEB128 shouldn't be generated from .uleb128 101 directives. 102 103 * Add support for the KVX instruction set. 104 105 * A new linker script sorting directive has been added: REVERSE. This reverses 106 the order of the sorting. It may be combined with either SORT_BY_NAME or 107 SORT_BY_INIT_PRIORITY. 108 109 * Added --warn-execstack-objects to warn about executable stacks only when an 110 input object file requests one. Also added --error-execstack and 111 --error-rxw-segments options to convert warnings about executable stacks and 112 segments into errors. 113 114 Also added --enable-error-execstack=[yes|no] and 115 --enable-error-rwx-segments=[yes|no] configure options to set the default for 116 converting warnings into errors. 117 118 * On LoongArch, various linker relaxation bugs are fixed; the most notable 119 of which is BZ 30944 (incorrect .balign semantics). 120 121 * On LoongArch, the LoongArch ABI v2.30 (LoongArch ELF psABI v20231219) is 122 now implemented. This includes new relocation types, and changed 123 semantics for PC-relative relocations handling the higher half of 64-bit 124 offsets. 125 126 * On LoongArch, link-time TLS optimization and TLS relaxation are now 127 supported. 128 129 Changes in 2.41: 130 131 * The linker now accepts a command line option of --remap-inputs 132 <PATTERN>=<FILE> to relace any input file that matches <PATTERN> with 133 <FILE>. In addition the option --remap-inputs-file=<FILE> can be used to 134 specify a file containing any number of these remapping directives. 135 136 * The linker command line option --print-map-locals can be used to include 137 local symbols in a linker map. (ELF targets only). 138 139 * For most ELF based targets, if the --enable-linker-version option is used 140 then the version of the linker will be inserted as a string into the .comment 141 section. 142 143 * The linker script syntax has a new command for output sections: ASCIZ "string" 144 This will insert a zero-terminated string at the current location. 145 146 * Add command-line option, -z nosectionheader, to omit ELF section 147 header. 148 149 Changes in 2.40: 150 151 * The linker has a new command line option to suppress the generation of any 152 warning or error messages. This can be useful when there is a need to create 153 a known non-working binary. The option is -w or --no-warnings. 154 155 * ld now supports zstd compressed debug sections. The new option 156 --compress-debug-sections=zstd compresses debug sections with zstd. 157 158 * Add --enable-default-compressed-debug-sections-algorithm={zlib,zstd} 159 that selects the default compression algorithm 160 for --enable-compressed-debug-sections. 161 162 * Remove support for -z bndplt (MPX prefix instructions). 163 164 Changes in 2.39: 165 166 * The ELF linker will now generate a warning message if the stack is made 167 executable. By default this warning is not issued if the user has 168 specifically requested an executable stack via the "-z execstack" 169 command line option, but the warning can be forced via the new 170 "--warn-execstack" option. Alternatively all warnings about creating 171 an executable stack can be suppressed via the "--no-warn-execstack" 172 option. 173 174 In addition the ELF linker will also warn if it creates a memory resident 175 segment with all three of the Read, Write and eXecute permissions set, or 176 if it creates a thread local data segment with the eXecute permission set. 177 These warnings can be disabled via --no-warn-rwx-segments option and 178 re-enabled via the --warn-rwx-segments option. 179 180 New configure options can also control these new features: 181 182 --enable-warn-execstack=no 183 will disable the warnings about creating an executable stack. 184 185 --enable-warn-execstack=yes 186 will make --warn-execstack enabled by default. 187 188 --enable-warn-rwx-segments=no 189 will make --no-warn-rwx-segments enabled by default. 190 191 --enable-default-execstack=no 192 will stop the creation of an executable stack simply because an input file 193 is missing a .note.GNU-stack section, even on architectures where this 194 behaviour is the default. 195 196 * TYPE=<type> is now supported in an output section description to set the 197 section type value. 198 199 * Remove (rudimentary) support for the x86-64 sub-architectures Intel L1OM and 200 Intel K1OM. 201 202 * The ELF linker now supports a new --package-metadata option that allows 203 embedding a JSON payload in accordance to the Package Metadata specification. 204 If support for libjansson is enabled at build time, the linker will use it to 205 validate the input. This can be enabled with --enable-jansson. 206 For more details, see: https://systemd.io/ELF_PACKAGE_METADATA/ 207 208 Changes in 2.38: 209 210 * Add -z pack-relative-relocs/-z no pack-relative-relocs to x86 ELF 211 linker to pack relative relocations in the DT_RELR section. 212 213 * Add support for the LoongArch architecture. 214 215 * Add -z indirect-extern-access/-z noindirect-extern-access to x86 ELF 216 linker to control canonical function pointers and copy relocation. 217 218 * Add --max-cache-size=SIZE to set the the maximum cache size to SIZE 219 bytes. 220 221 Changes in 2.37: 222 223 * arm-symbianelf support removed. 224 225 * Add -z report-relative-reloc to x86 ELF linker to report dynamic 226 relative relocations. 227 228 * Add -z start-stop-gc to disable special treatment of __start_*/__stop_* 229 references when --gc-sections. 230 231 * Add -Bno-symbolic to cancel -Bsymbolic and -Bsymbolic-functions. 232 233 Changes in 2.36: 234 235 * Add libdep plugin, for linking dependencies of static libraries that 236 were recorded by ar in the __.LIBDEP archive member. 237 238 * Add --error-handling-script=<NAME> command line option to allow a helper 239 script to be invoked when an undefined symbol or a missing library is 240 encountered. This option can be suppressed via the configure time 241 switch: --enable-error-handling-script=no. 242 243 * Add -z lam-u48 to x86-64 ELF linker to generate LAM_U48 property. 244 245 * Add -z lam-u57 to x86-64 ELF linker to enerate LAM_U57 property. 246 247 * Add -z lam-u48-report=[none|warning|error] to report missing LAM_U48 248 property. 249 250 * Add -z lam-u57-report=[none|warning|error] to report missing LAM_U57 251 property. 252 253 * Add -z lam-report=[none|warning|error] to report missing LAM_U48 and 254 LAM_U57 properties. 255 256 * Add -z x86-64-{baseline|v[234]} to the x86 ELF linker to mark 257 x86-64-{baseline|v[234]} ISA level as needed. 258 259 * Add -z unique-symbol to avoid duplicated local symbol names. 260 261 * The creation of PE format DLLs now defaults to using a more secure set of DLL 262 characteristics. 263 264 * The linker now deduplicates the types in .ctf sections. The new 265 command-line option --ctf-share-types describes how to do this: 266 its default value, share-unconflicted, produces the most compact 267 output. 268 269 * The linker now omits the "variable section" from .ctf sections by 270 default, saving space. This is almost certainly what you want 271 unless you are working on a project that has its own analogue 272 of symbol tables that are not reflected in the ELF symtabs. 273 274 * Add support for the SHF_GNU_RETAIN ELF section flag. 275 This flag specifies that the section should not be garbage collected by the 276 linker. 277 278 Changes in 2.35: 279 280 * X86 NaCl target support is removed. 281 282 * Add ELF linker command-line options, --export-dynamic-symbol and 283 --export-dynamic-symbol-list, to make symbols dynamic. 284 285 * Add a configure option, --enable-textrel-check=[no|yes|warning|error], 286 to decide what ELF linker should do by default with DT_TEXTREL in an 287 executable or shared library. Default to yes for Linux/x86 targets. 288 289 * The -Map=<filename> command line option has been extended so that if 290 <filename> is a directory then <filename>/<output-filename>.map will be 291 created. 292 293 * Add a command-line option for ELF linker, --warn-textrel, to warn that 294 DT_TEXTREL is set in a position-independent executable or shared object. 295 296 * Add command-line options --enable-non-contiguous-regions and 297 --enable-non-contiguous-regions-warnings. 298 299 * Add command-line option --imagic for the pdp11-aout target to output format 300 IMAGIC (0411) for separate instruction and data spaces, and change the 301 default format option for pdp11-aout to be --omagic. 302 303 * Relative pathnames in INPUT() and GROUP() directives in linker scripts are 304 searched relative to the directory of the linker script before other search 305 paths. 306 307 * Add ELF linker command-line option `-z start-stop-visibility=...' to control 308 the visibility of synthetic `__start_SECNAME` and `__stop_SECNAME` symbols. 309 310 * Add command-line option --dependency-file to write a Make-style dependency 311 file listing the input files consulted by the linker, like the files written 312 by the compiler's -M -MP options. 313 314 Changes in 2.34: 315 316 * The ld check for "PHDR segment not covered by LOAD segment" is more 317 effective, catching cases that were wrongly allowed by previous versions of 318 ld. If you see this error it is likely you are linking with a bad linker 319 script or the binary you are building is not intended to be loaded by a 320 dynamic loader. In the latter case --no-dynamic-linker is appropriate. 321 322 * cr16c support removed. 323 324 * Add support for z80-elf. 325 326 * Add support for relocation of each byte or word of multibyte value to Z80 327 targets. 328 329 * Add support for Zilog eZ80 (both ADL and Z80 mode) and Zilog Z180 CPUs. 330 331 Changes in 2.33: 332 333 * Add command-line option --no-print-map-discarded. 334 335 * The Cortex-A53 Erratum 843419 workaround now supports a choice of which 336 workaround to use. The option --fix-cortex-a53-843419 now takes an 337 optional argument --fix-cortex-a53-843419[=full|adr|adrp] which can be 338 used to force a particular workaround to be used. See --help for AArch64 339 for more details. 340 341 * Add target handlers for AArch64 for ELF GNU program properties. 342 343 * Add support for GNU_PROPERTY_AARCH64_FEATURE_1_BTI in ELF GNU program 344 properties in the AArch64 ELF linker. 345 346 * Add support for GNU_PROPERTY_AARCH64_FEATURE_1_PAC in ELF GNU program 347 properties in the AArch64 ELF linker. 348 349 * Add -z force-bti for AArch64 to enable GNU_PROPERTY_AARCH64_FEATURE_1_BTI 350 on output while warning about missing GNU_PROPERTY_AARCH64_FEATURE_1_BTI 351 on inputs and use PLTs protected with BTI. 352 353 * Add -z pac-plt for AArch64 to pick PAC enabled PLTs. 354 355 Changes in 2.32: 356 357 * Report property change in linker map file when merging GNU properties. 358 359 * Add support for the C-SKY processor series. 360 361 * -t now doesn't report members within archives, unless -t is given twice. 362 A single -t is now more useful when generating a list of files that should be 363 packaged for a linker bug report. For example: 364 gcc hello.c -save-temps -Wl,-t | xargs realpath | sort | uniq > files 365 tar cJf test.tar.xz `cat files` 366 367 Changes in 2.31: 368 369 * Speed up direct linking with DLLs for Cygwin and Mingw targets. 370 371 * Add a configure option --enable-separate-code to decide whether 372 -z separate-code should be enabled in ELF linker by default. Default 373 to yes for Linux/x86 targets. Note that -z separate-code can increase 374 disk and memory size. 375 376 Changes in 2.30: 377 378 * Add -z separate-code to generate separate code PT_LOAD segment. 379 380 * Add "-z undefs" command-line option as the inverse of the "-z defs" option. 381 382 * Add -z globalaudit command-line option to force audit libraries to be run 383 for every dynamic object loaded by an executable - provided that the loader 384 supports this functionality. 385 386 * Tighten linker script grammar around file name specifiers to prevent the use 387 of SORT_BY_ALIGNMENT and SORT_BY_INIT_PRIORITY on filenames. These would 388 previously be accepted but had no effect. 389 390 * The EXCLUDE_FILE directive can now be placed within any SORT_* directive 391 within input section lists. 392 393 Changes in 2.29: 394 395 * Support for -z shstk in the x86 ELF linker to generate 396 GNU_PROPERTY_X86_FEATURE_1_SHSTK in ELF GNU program properties. 397 398 * Add support for GNU_PROPERTY_X86_FEATURE_1_SHSTK in ELF GNU program 399 properties in the x86 ELF linker. 400 401 * Add support for GNU_PROPERTY_X86_FEATURE_1_IBT in ELF GNU program 402 properties in the x86 ELF linker. 403 404 * Support for -z ibtplt in the x86 ELF linker to generate IBT-enabled 405 PLT. 406 407 * Support for -z ibt in the x86 ELF linker to generate IBT-enabled 408 PLT as well as GNU_PROPERTY_X86_FEATURE_1_IBT in ELF GNU program 409 properties. 410 411 * Add support for ELF SHF_GNU_MBIND and PT_GNU_MBIND_XXX. 412 413 * Add support for ELF GNU program properties. 414 415 * Add support for the Texas Instruments PRU processor. 416 417 * When configuring for arc*-*-linux* targets the default linker emulation will 418 change if --with-cpu=nps400 is used at configure time. 419 420 * Improve assignment of LMAs to orphan sections in some edge cases where a 421 mixture of both AT>LMA_REGION and AT(LMA) are used. 422 423 * Orphan sections placed after an empty section that has an AT(LMA) will now 424 take an load memory address starting from LMA. 425 426 * Section groups can now be resolved (the group deleted and the group members 427 placed like normal sections) at partial link time either using the new linker 428 option --force-group-allocation or by placing FORCE_GROUP_ALLOCATION into the 429 linker script. 430 431 Changes in 2.28: 432 433 * The EXCLUDE_FILE linker script construct can now be applied outside of the 434 section list in order for the exclusions to apply over all input sections in 435 the list. 436 437 * Add support for the RISC-V architecture. 438 439 * The command-line option --no-eh-frame-hdr can now be used in ELF based 440 linkers to disable the automatic generation of .eh_frame_hdr sections. 441 442 * Add --in-implib=<infile> to the ARM linker to enable specifying a set of 443 Secure Gateway veneers that must exist in the output import library specified 444 by --out-implib=<outfile> and the address they must have. As such, 445 --in-implib is only supported in combination with --cmse-implib. 446 447 * Extended the --out-implib=<file> option, previously restricted to x86 PE 448 targets, to any ELF based target. This allows the generation of an import 449 library for an ELF executable, which can then be used by another application 450 to link against the executable. 451 452 Changes in 2.27: 453 454 * Add a configure option --enable-relro to decide whether -z relro should 455 be enabled in ELF linker by default. Default to yes for all Linux 456 targets except FRV, HPPA, IA64 and MIPS. Note that -z relro can increase 457 disk and memory size. 458 459 * Support for -z noreloc-overflow in the x86-64 ELF linker to disable 460 relocation overflow check. 461 462 * Add -z common/-z nocommon options for ELF targets to control whether to 463 convert common symbols to the STT_COMMON type during a relocatable link. 464 465 * Support for -z nodynamic-undefined-weak in the x86 ELF linker, which 466 avoids dynamic relocations against undefined weak symbols in executable. 467 468 * The NOCROSSREFSTO command was added to the linker script language. 469 470 * Add --no-apply-dynamic-relocs to the AArch64 linker to do not apply link-time 471 values for dynamic relocations. 472 473 Changes in 2.26: 474 475 * Add --fix-stm32l4xx-629360 to the ARM linker to enable a link-time 476 workaround for a bug in the bus matrix / memory controller for some of 477 the STM32 Cortex-M4 based products (STM32L4xx) 478 479 * Add a configure option --enable-compressed-debug-sections={all,ld} to 480 decide whether DWARF debug sections should be compressed by default. 481 482 * Add support for the ARC EM/HS, and ARC600/700 architectures. 483 484 * Experimental support for linker garbage collection (--gc-sections) 485 has been enabled for COFF and PE based targets. 486 487 * New command-line option for ELF targets to compress DWARF debug 488 sections, --compress-debug-sections=[none|zlib|zlib-gnu|zlib-gabi]. 489 490 * New command-line option, --orphan-handling=[place|warn|error|discard], to 491 adjust how orphan sections are handled. The default is 'place' which gives 492 the current behaviour, 'warn' and 'error' issue a warning or error 493 respectively when orphan sections are found, and 'discard' will discard all 494 orphan sections. 495 496 * Add support for LLVM plugin. 497 498 * Add --print-memory-usage option to report memory blocks usage. 499 500 * Add --require-defined option, it's like --undefined except the new symbol 501 must be defined by the end of the link. 502 503 Changes in 2.25: 504 505 * PE binaries now once again contain real timestamps by default. To disable 506 the inclusion of a timestamp in a PE binary, use the --no-insert-timestamp 507 command-line option. 508 509 * Replace support for openrisc and or32 with support for or1k. 510 511 * Add support for the --build-id command-line option to COFF based targets. 512 513 * x86/x86_64 pe-coff now supports the --build-id option. 514 515 * Add support for the Andes NDS32. 516 517 Changes in 2.24: 518 519 * Add LOG2CEIL() builtin function to the linker script language 520 521 * Add support for the Texas Instruments MSP430X processor. 522 523 * Add support for Altera Nios II. 524 525 * Add support for the V850E3V5 architecture. 526 527 * Add support for the Imagination Technologies Meta processor. 528 529 * --enable-new-dtags no longer generates old dtags in addition to new dtags. 530 531 * Remove linker support for MIPS ECOFF targets. 532 533 * Add ALIGN_WITH_INPUT to the linker script language to force the alignment of 534 an output section to use the maximum alignment of all its input sections. 535 536 Changes in 2.23: 537 538 * Enable compressed debug section feature for x86/x86_64 pe-coff. 539 540 * Add support for the 64-bit ARM architecture: AArch64. 541 542 * Added SORT_NONE to the linker script language to disable section sorting. 543 544 * Add a linker-provided symbol when producing ELF output, '__ehdr_start' 545 to point to the ELF file header (and nearby program headers) in the 546 program's memory image. 547 548 * Add support for S12X processor. 549 550 * Add support for the VLE extension to the PowerPC architecture. 551 552 * Add support for the Freescale XGATE architecture. 553 554 * Add option -f FILE on AIX (for response file). 555 556 * Add support for the Renesas RL78 architecture. 557 558 * Add support for the Adapteva EPIPHANY architecture. 559 560 Changes in 2.22: 561 562 * --copy-dt-needed-entries is no longer enabled by default. Instead 563 --no-copy-dt-needed-entries is the default. 564 565 * INPUT_SECTION_FLAGS has been added to the linker script language 566 to allow selection of input sections by section header section flags. 567 568 * Add support for the Tilera TILEPro and TILE-Gx architectures. 569 570 * Added SORT_BY_INIT_PRIORITY to the linker script language to permit 571 sorting sections by numerical value of the GCC init_priority attribute 572 encoded in the section name. 573 574 Changes in 2.21: 575 576 * Linker script expression evaluation is somewhat more sane. This may 577 break scripts that depend on quirks of the old expression evaluation. 578 579 * Turn off underscoring for x86_64 PE+-COFF targets. For old behavior the 580 option --enable-leading-mingw64-underscores can be used on configure of 581 bfd. 582 583 * Add support for the TMS320C6000 (TI C6X) processor family. 584 585 * --add-needed renamed to --copy-dt-needed-entries in order to avoid confusion 586 with --as-needed option. 587 588 * Extend .def file syntax by '== <ID>' for imports and exports. This allows 589 to alias the import/export table name written in PE image. 590 591 * Add --exclude-all-symbols option to PE based linkers. This prevents all 592 symbols from automatically being exported. 593 594 * Add support for the Renesas RX processor. 595 596 * Add support for alpha-vms target. 597 598 Changes in 2.20: 599 600 * GNU/Linux targets now support the STB_GNU_UNIQUE symbol binding. This is a 601 GNU extension to the standard set of ELF symbol bindings. The binding will 602 be passed on to the dynamic linker which will make sure that in the entire 603 process there is just one symbol with the given name and type in use. 604 605 * PE targets now support a GNU extension to allow the alignment of common 606 common symbols to be specified. This support uses custom options in 607 the .drectve section, which will be disregarded by the native tools. 608 609 * PE targets now add primitive support for ELF version scripts; symbols 610 are not versioned, but the local and global symbol visibility directives 611 are respected when filtering symbols in auto-export mode. 612 613 * New option --no-export-dynamic to undo the effect of the -E and 614 --export-dynamic options. 615 616 * ELF: --warn-alternate-em option to warn if an object has alternate 617 ELF machine code. 618 619 * New script function REGION_ALIAS to add alias names to memory regions. 620 621 * PE targets no longer make use of the long section names PE extension to 622 the COFF format when generating executable images, by default. The old 623 (slightly non-conformant) behaviour can still be invoked by using the 624 new '--enable-long-section-names' command-line option. It is also enabled 625 automatically in the presence of un-stripped debug information, as GDB 626 needs to be able to find the debug info sections by their full names. 627 628 * For GNU/Linux systems the linker will now avoid processing any relocations 629 made against symbols of the STT_GNU_IFUNC type and instead emit them into 630 the resulting binary for processing by the loader. 631 632 * --as-needed now links in a dynamic library if it satisfies undefined 633 symbols in regular objects, or in other dynamic libraries. In the 634 latter case the library is not linked if it is found in a DT_NEEDED 635 entry of one of the libraries already linked. 636 637 * Add a new command-line option, -Ttext-segment ADDR, for ELF targets 638 to set the address of the first byte of the text segment. 639 640 * Add support for Sunplus score architecture. 641 642 * Add new option --use-nul-prefixed-import-tables to ld for PE targets to 643 allow fallback to old import table generation with null element prefix. 644 645 * Windows PE systems now support a new --exclude-modules-for-implib option, 646 allowing users to partition object files and archive members between a DLL 647 and its associated import library as they are generated during linking. 648 649 * Add support for Lattice Mico32 (lm32) architecture. 650 651 * Add CR16 ELF --embedded-relocs (used to embedded relocations into binaries 652 for Embedded-PIC code) option. 653 654 * Add to the PE/PE+ targets the support of two different kinds of 655 pseudo-relocations. They can be selected by the switches 656 --enable-runtime-pseudo-reloc-v1 and --enable-runtime-pseudo-reloc-v2. 657 For the switch --enable-runtime-pseudo-reloc it uses for 32-bit 658 runtime pseudo relocation version one, for 64-bit the version two. 659 660 Changes in 2.19: 661 662 * Linker scripts support a new INSERT command that makes it easier to 663 augment the default script. 664 665 * Linker script input section filespecs may now specify a file within an 666 archive by writing "archive:file". 667 668 * The --sort-common switch now has an optional argument which specifies the 669 direction of sorting. 670 671 * The M68K linker now supports multiple GOT generation schemes controlled via 672 the --got=<type> command-line option. 673 674 * The ARM EABI linker will now generate stubs for function calls to symbols 675 that are too far away. The placement of the stubs is controlled by a new 676 linker command-line option: --stub-group-size=N. 677 678 Changes in 2.18: 679 680 * Linker sources now released under version 3 of the GNU General Public 681 License. 682 683 * ELF: New --build-id option to generate a unique per-binary identifier 684 embedded in a note section. 685 686 * Added support for National Semicondutor CompactRISC (ie CR16) target. 687 688 * -l:foo now searches the library path for a filename called foo, 689 without converting it to libfoo.a or libfoo.so. 690 691 * Add a new command-line option '--default-script=FILE' or '-dT FILE' 692 which specifies a replacement for the built in, default linker 693 script. 694 695 * ELF: Add -Bsymbolic-functions, --dynamic-list-cpp-new, which puts C++ 696 operator new and delete on the dynamic list, and --dynamic-list-data, 697 builtin list for --dynamic-list, which puts global data symbols on the 698 dynamic list. 699 700 * Add support for x86_64 PE+ target. 701 702 * Add support for Score target. 703 704 * ELF: Add --dynamic-list option to specify a list of global symbols 705 whose references shouldn't be bound to the definition within the 706 shared library, or a list of symbols which should be added to the 707 symbol table in the executable. 708 709 * The default output section LMA has changed for allocatable sections from 710 being equal to VMA, to keeping the difference between LMA and VMA the same as 711 the previous output section in the same region. This is a more useful 712 default when using overlays and other cases where you specify an LMA 713 differing from the VMA for some sections. 714 715 * New switch: --print-gc-sections to list any sections removed by garabge 716 collection. 717 718 * ARM: Added --vfp11-denorm-fix option to work around an erratum in current 719 VFP11 coprocessors. 720 721 Changes in 2.17: 722 723 * Support for the Infineon XC16X has been added by KPIT Cummins Infosystems. 724 725 * Modify the Linux linker search order to better match ld.so search order. 726 Look for DT_NEEDED libraries in paths specified by ld.so.conf before 727 searching the default directories, rather than vice versa. 728 Use $prefix/etc/ld.so.conf if it exists, otherwise /etc/ld.so.conf. 729 730 * PE-COFF: Forward exports from DLL's can now be specified in .def files 731 passed directly to ld. 732 733 * Support for the Z80 processor family has been added. 734 735 * Add support for the "@<file>" syntax to the command line, so that extra 736 switches can be read from <file>. 737 738 Changes in 2.16: 739 740 * Support for the R_ARM_V4BX relocation as defined in the ARM AAELF 741 specification has been added via the --fix-v4bx command-line option. 742 743 * New linker script construct AS_NEEDED(), which sets the --as-needed flag 744 for input files listed inside of it. 745 746 * A new command-line option, --sysroot, can be used to override the 747 default sysroot location. It only applies to toolchains that were 748 configured using --with-sysroot. 749 750 * New linker script functions: ORIGIN() and LENGTH() which return information 751 about a specified memory region. 752 753 * Port to MAXQ processor contributed by HCL Tech. 754 755 * Added SEGMENT_START to the linker script language to permit the user to 756 override the base address for a segment from the command-line. 757 758 * ELF: --warn-shared-textrel option to warn if adding a DT_TEXTREL to a shared 759 object. 760 761 * Added SORT_BY_NAME and SORT_BY_ALIGNMENT to the linker script 762 language to permit sorting sections by section name or section 763 maximum alignment. 764 765 * Added a new linker command-line switch, --sort-section name|alignment, 766 to sort sections by section name or maximum alignment. 767 768 * ELF: --add-needed/--no-add-needed options to control if a DT_NEEDED tag 769 should be added when a shared library comes from DT_NEEDED tags. 770 771 * Support for the crx-elf target added. 772 773 * Support for the sh-symbianelf target added. 774 775 * A new linker command-line switch has been added which allows the hash table 776 size to be set to a suitable prime value near to its argument. This switch 777 is --hash-size=<NUMBER>. Also if the switch --reduce-memory-overheads is 778 used, and --hash-size has not been used, then the default value will be set 779 to 1021. 780 781 * Linker map files are now generated with an O(N) algorithm for finding symbols 782 that are defined in each section. This uses about 40% more memory for 783 symbols than the old O(N^2) algorithm. You can use the new 784 --reduce-memory-overheads option to select the old algorithm; this option 785 might also be used in the future to select similar tradeoffs. 786 787 Changes in 2.15: 788 789 * ELF: --as-needed/--no-as-needed options to control if a DT_NEEDED tag should 790 be added only when a shared library is referenced. 791 792 * PE: --large-address-aware option to indicate executables support virtual 793 addresses greater than 2 gigabytes. 794 795 * DWARF 2 support for i386pe added. 796 797 * The linker script operator DEFINED() will now yield 1 only for a symbol that 798 is defined before the statement where DEFINED is used. 799 800 * The MIPS --embedded-relocs (used to embed relocations into binaries for 801 Embedded-PIC code) is deprecated and will be removed in a future release. 802 803 * cr16c support added by NSC. 804 805 * m32r Linux (ELF) support added by Renesas. 806 807 * Improved linker's handling of unresolved symbols. The switch 808 --unresolved-symbols=<method> has been added to tell the linker when it 809 should report them and the switch --warn-unresolved-symbols has been added to 810 make reports be issued as warning messages rather than errors. 811 812 Changes in 2.14: 813 814 * Added support for Xtensa architecture. 815 816 * Added --with-sysroot configure switch to specify a target system root, for 817 linking against a target filesystem image. 818 819 * Added --accept-unknown-linker-format to restore old linker behaviour (pre 820 2.14) of silently accepting and linking in any files in an unknown binary 821 file format. 822 823 * Added --no-omagic to undo the effects of the -N option. 824 825 * Support for Texas Instruments TMS320C4x and TMS320C3x series of 826 DSP's contributed by Michael Hayes and Svein E. Seldal. 827 828 * Added --with-lib-path configure switch to specify default value for 829 LIB_PATH. 830 831 * ARM port to QNX operating system added by Graeme Peterson. 832 833 * IP2K support added by Denis Chertykov. 834 835 Changes in 2.13: 836 837 * Support for the Fujitsu FRV architecture added by Red Hat. Models for FR400 838 and FR500 included. 839 840 Changes in version 2.13: 841 842 * DEC VAX ELF support, by Matt Thomas. 843 844 Changes in version 2.12: 845 846 * Support for Don Knuth's MMIX, by Hans-Peter Nilsson. 847 848 * Support for the OpenRISC 32-bit embedded processor by OpenCores. 849 850 * Support for -z nocopyreloc in the x86 ELF linker, which disables 851 production of copy relocs. Warning: using this option may result in 852 non-sharable applications. 853 854 * Support for -z combreloc in the ELF linker, which puts dynamic 855 relocations against the same symbol together, so that dynamic linker 856 can use an one-entry symbol lookup cache. 857 858 * Support for ELF SHF_MERGE section merging, by Jakub Jelinek. 859 860 Changes in version 2.11: 861 862 * Support for AMD x86-64 architecture, by Jan Hubicka, SuSE Labs. 863 864 * Support added for eliminating duplicate DWARF2 debug information by 865 having the compiler generate the information in sections called 866 .gnu.linkonce.wi.XXXX where XXXX is a checksum for the contents. The 867 linker then merges these sections together into the normal .debug_info 868 section. 869 870 * The native ELF linker now searches the directories in DT_RUNPATH or 871 DT_RPATH of a shared library for shared libraries needed by it. 872 873 * TI C54x support, by Timothy Wall. 874 875 * Added command-line switch --section-start to set the start address of any 876 specified section. 877 878 * Added ability to emit full relocation information in linked executables, 879 enabled by --emit-relocs. Some post-linkage optimization tools need 880 this information in order to be able to correctly identify and perform 881 symbol relative addressing in the event of changes in section contents 882 (instructions being added or deleted, extending data sections, etc.) 883 884 * Support for i860, by Jason Eckhardt (preliminary, alpha quality). 885 886 * Support for CRIS (Axis Communications ETRAX series). 887 888 * Support for PDP-11 and 2.11BSD a.out format, by Lars Brinkhoff. 889 890 Changes in version 2.10: 891 892 * Added AT> to the linker script language to allow load-time allocation of 893 sections into regions. 894 895 * Added garbage collection of unused sections, enabled by --gc-sections. 896 It does require a bit of backend support; currently implemented are 897 arm-elf, avr-elf, d10v-elf, fr30-elf, i386-elf, m32r-elf, m68k-elf, 898 mcore-elf, mips-elf, mn10300-elf, ppc-elf, sh-elf, sparc-elf, and v850-elf. 899 Others will ignore the option. 900 901 * Added SORT to the linker script language to permit sorting sections by file 902 name or section name. 903 904 * Added EXTERN to the linker script language as an equivalent to the -u 905 command-line option. 906 907 * Added ASSERT to the linker script language. 908 909 * Added EXCLUDE_FILE to the linker script language for further control over 910 wildcard file names. 911 912 * Added -O option to optimize linker output (as of this writing, this only 913 affects ELF shared library generation). 914 915 * The -e option now accepts a number as well as a symbol name. 916 917 * Added --no-undefined option to disallow undefined symbols when creating a 918 shared library. 919 920 * The linker now issues a warning, not an error, for an undefined symbol when 921 using -Bsymbolic; use the new --no-undefined option to get the old 922 behaviour. 923 924 * Added --demangle and --no-demangle options. 925 926 Changes in version 2.9: 927 928 * Added SQUAD to the linker script language. 929 930 * New option --no-warn-mismatch. 931 932 * The MEMORY command now parses the attributes to determine where sections that 933 are not placed in a specific memory region are placed. 934 935 Changes in version 2.8: 936 937 * Linker scripts may now contain shell wildcard characters for file and section 938 names. 939 940 * The linker now supports symbol versions in ELF. 941 942 * The NOCROSSREFS command was added to the linker script language. 943 944 * The LOADADDR expression was added to the linker script language. 945 946 * MAX and MIN functions were added to the linker script language. 947 948 * The OVERLAY construct was added to the linker script language. 949 950 * New option --warn-section-align to warn when the address of an output section 951 changes due to alignment of an input section. 952 953 * New options --filter/-F and --auxiliary/-f. 954 955 Changes in version 2.7: 956 957 * New option --cref to print out a cross reference table. 958 959 * New option --wrap SYMBOL. 960 961 * New option --no-whole-archive, to turn off the effect of --whole-archive. 962 963 * Input sections assigned to the output section /DISCARD/ in the linker script 964 are not included in the output file. 965 966 * The SunOS and ELF linkers now merge stabs debugging information which uses 967 the N_BINCL and N_EINCL stab types. This reduces the amount of debugging 968 information generated. 969 970 Changes in version 2.6: 971 972 * When an ELF section name is representable as a C identifier (this is not true 973 of most ELF section names), the linker will automatically define symbols 974 __start_SECNAME and __stop_SECNAME, where SECNAME is the section name, at the 975 beginning and the end of the section. This is used by glibc. 976 977 Addendum: Current versions of the linker (at least for version 2.18 onwards 978 and possibly much earlier as well) place two restrictions on this feature: The 979 symbols are only implemented for orphaned sections, not for explicitly placed 980 sections and they are PROVIDEd rather than being defined. 981 982 * When an ELF section named .gnu.warning is encountered in an input file, the 983 contents of the section are displayed as an error message, and the section is 984 not copied into the output file. This is used by glibc. 985 986 * When an ELF section named .gnu.warning.SYMBOL is encountered in an input 987 file, and the symbol SYMBOL is referenced by some object file, the contents of 988 the section are displayed as an error message. The section is not copied into 989 the output file, unless doing a relocatable or shared link. This is used by 990 glibc. 991 992 * New options -split-by-reloc and -split-by-file. 993 994 * The linker now supports linking PIC compiled code on SPARC SunOS. It can 995 also create SPARC SunOS shared libraries, and, like the native SunOS linker, 996 will do so whenever there is an undefined symbol in the link and neither the -e 997 nor the -r option was used. 998 999 * The -rpath option may be used on SunOS to set the list of directories to be 1000 searched at run time. This overrides the default of building the list from the 1001 -L options. 1002 1003 * The COFF linker now combines debugging information for structs, unions, and 1004 enums, so that even if the same type is defined in multiple input files it will 1005 only be defined once in the output file. The --traditional-format switch will 1006 prevent this optimization. 1007 1008 Changes in version 2.5: 1009 1010 * The linker now supports linking against SunOS shared libraries. It still can 1011 not link SunOS PIC (Position Independent Code) files, so it can not be used to 1012 generate shared libraries. 1013 1014 * The linker now supports linking against ELF shared libraries for the i386 1015 (UnixWare) and SPARC (Solaris). It can also link ELF PIC files, and can be 1016 used to generate shared libraries. Shared library generation is not well 1017 tested; please report any problems encountered. The linker is now enabled for 1018 Solaris again. 1019 1020 * Eric Youngdale has contributed Linux support code, including linking against 1021 Linux a.out shared libraries. The linker produces Linux QMAGIC binaries. 1022 1023 * The ELF backend has been converted to the new linker code. To use the new 1024 ELF linker, each particular target requires a relocation function. So far, 1025 this function has been written for i386 (UnixWare), SPARC (Solaris) MIPS (Irix 1026 5), and HPPA ELF targets. 1027 1028 * The -( (--start-group) and -) (--end-group) options have been added to 1029 support searching a group of archives as though they were a single archive. 1030 This can also be used in a linker script, as GROUP ( files ). 1031 1032 * When a file is named on the command line, and the linker does not recognize 1033 it as an object file, the linker will now treat the file as a linker script 1034 file. A linker script named in this way augments, but does not replace, the 1035 default linker script. 1036 1037 * The -warn-once option was added. It causes the linker to only warn once per 1038 undefined symbol, rather than once per reference. 1039 1040 * The COFF backend has been converted to the new linker code. As with ELF, to 1041 use the new linker, each particular target requires a relocation function. So 1042 far, this function has been written for the i386, m68k, a29k and SH targets. 1043 1044 * The -V flag was made a synonym for -v, for SVR4 compatibility. The old -V 1045 behaviour is available via --verbose. 1046 1047 Changes in version 2.4: 1048 1049 * New linker code, by Steve Chamberlain and Ian Taylor. For a.out and ecoff 1050 formats (so far), this should result in considerable savings in time 1051 and memory used while linking; slightly poorer performance than 1052 before for formats not converted yet. 1053 1054 * Command-line parsing is no longer done with flex. This means 1055 oddball characters in filenames won't get treated as argument 1056 separators. 1057 1058 * HP-PA ELF support, by Jeff Law. (No SOM support yet.) 1059 1060 * Mach i386 support, by David Mackenzie. 1061 1062 * Irix 4 shared libraries are now supported (Irix 5 uses ELF, and ELF shared 1063 libraries are not yet supported). 1064 1065 * COFF shared libraries (as on SCO) should work as well. 1066 1067 * The linker is disabled for Solaris. (Actually, it was in 2.3 also, I just 1068 forgot to note it.) Some of their C library routines don't work when 1069 statically linked, and the GNU linker doesn't support dynamic linking yet. 1070 1071 Changes in version 2.3: 1072 1073 * Weak symbols are now supported. 1074 1075 * ELF support has been added. The linker has been bootstrapped on 1076 UnixWare and Solaris. 1077 1078 * Alpha OSF/1 support has been added (non dynamic linking only). 1079 1080 Changes in version 2.2: 1081 1082 * The `bfd' library has been updated to reduce a.out-format string 1083 table size. The effect of this is that files linked from many input 1084 files with duplicate symbols (`-g' debugging records, or identical 1085 static symbols) should be much smaller. 1086 1087 Changes in version 2.1: 1088 1089 * The ld -ySYMBOL flag (to trace references to SYMBOL) is now implemented. 1090 1091 * There is now support for writing ECOFF files, so ld and the 1092 other utilities should work on Risc/Ultrix and Irix. 1093 1094 1096 Copyright (C) 2012-2025 Free Software Foundation, Inc. 1097 1098 Copying and distribution of this file, with or without modification, 1099 are permitted in any medium without royalty provided the copyright 1100 notice and this notice are preserved. 1101 1102 Local variables: 1103 fill-column: 79 1104 End: 1105