ld/NEWS

   1 -*- text -*-
   2
   3 Changes in 2.34:
   4
   5 * cr16c support removed.
   6
   7 * Add support for z80-elf.
   8
   9 * Add support for relocation of each byte or word of multibyte value to Z80
  10   targets.
  11
  12 * Add support for Zilog eZ80 (both ADL and Z80 mode) and Zilog Z180 CPUs.
  13
  14 Changes in 2.33:
  15
  16 * Add command-line option --no-print-map-discarded.
  17
  18 * The Cortex-A53 Erratum 843419 workaround now supports a choice of which
  19   workaround to use.  The option --fix-cortex-a53-843419 now takes an
  20   optional argument --fix-cortex-a53-843419[=full|adr|adrp] which can be
  21   used to force a particular workaround to be used.  See --help for AArch64
  22   for more details.
  23
  24 * Add target handlers for AArch64 for ELF GNU program properties.
  25
  26 * Add support for GNU_PROPERTY_AARCH64_FEATURE_1_BTI in ELF GNU program
  27   properties in the AArch64 ELF linker.
  28
  29 * Add support for GNU_PROPERTY_AARCH64_FEATURE_1_PAC in ELF GNU program
  30   properties in the AArch64 ELF linker.
  31
  32 * Add -z force-bti for AArch64 to enable GNU_PROPERTY_AARCH64_FEATURE_1_BTI
  33   on output while warning about missing GNU_PROPERTY_AARCH64_FEATURE_1_BTI
  34   on inputs and use PLTs protected with BTI.
  35
  36 * Add -z pac-plt for AArch64 to pick PAC enabled PLTs.
  37
  38 Changes in 2.32:
  39
  40 * Report property change in linker map file when merging GNU properties.
  41
  42 * Add support for the C-SKY processor series.
  43
  44 * -t now doesn't report members within archives, unless -t is given twice.
  45   A single -t is now more useful when generating a list of files that should be
  46   packaged for a linker bug report.  For example:
  47     gcc hello.c -save-temps -Wl,-t | xargs realpath | sort | uniq > files
  48     tar cJf test.tar.xz `cat files`
  49
  50 Changes in 2.31:
  51
  52 * Speed up direct linking with DLLs for Cygwin and Mingw targets.
  53
  54 * Add a configure option --enable-separate-code to decide whether
  55   -z separate-code should be enabled in ELF linker by default.  Default
  56   to yes for Linux/x86 targets.  Note that -z separate-code can increase
  57   disk and memory size.
  58
  59 Changes in 2.30:
  60
  61 * Add -z separate-code to generate separate code PT_LOAD segment.
  62
  63 * Add "-z undefs" command-line option as the inverse of the "-z defs" option.
  64
  65 * Add -z globalaudit command-line option to force audit libraries to be run
  66   for every dynamic object loaded by an executable - provided that the loader
  67   supports this functionality.
  68
  69 * Tighten linker script grammar around file name specifiers to prevent the use
  70   of SORT_BY_ALIGNMENT and SORT_BY_INIT_PRIORITY on filenames.  These would
  71   previously be accepted but had no effect.
  72
  73 * The EXCLUDE_FILE directive can now be placed within any SORT_* directive
  74   within input section lists.
  75
  76 Changes in 2.29:
  77
  78 * Support for -z shstk in the x86 ELF linker to generate
  79   GNU_PROPERTY_X86_FEATURE_1_SHSTK in ELF GNU program properties.
  80
  81 * Add support for GNU_PROPERTY_X86_FEATURE_1_SHSTK in ELF GNU program
  82   properties in the x86 ELF linker.
  83
  84 * Add support for GNU_PROPERTY_X86_FEATURE_1_IBT in ELF GNU program
  85   properties in the x86 ELF linker.
  86
  87 * Support for -z ibtplt in the x86 ELF linker to generate IBT-enabled
  88   PLT.
  89
  90 * Support for -z ibt in the x86 ELF linker to generate IBT-enabled
  91   PLT as well as GNU_PROPERTY_X86_FEATURE_1_IBT in ELF GNU program
  92   properties.
  93
  94 * Add support for ELF SHF_GNU_MBIND and PT_GNU_MBIND_XXX.
  95
  96 * Add support for ELF GNU program properties.
  97
  98 * Add support for the Texas Instruments PRU processor.
  99
 100 * When configuring for arc*-*-linux* targets the default linker emulation will
 101   change if --with-cpu=nps400 is used at configure time.
 102
 103 * Improve assignment of LMAs to orphan sections in some edge cases where a
 104   mixture of both AT>LMA_REGION and AT(LMA) are used.
 105
 106 * Orphan sections placed after an empty section that has an AT(LMA) will now
 107   take an load memory address starting from LMA.
 108
 109 * Section groups can now be resolved (the group deleted and the group members
 110   placed like normal sections) at partial link time either using the new linker
 111   option --force-group-allocation or by placing FORCE_GROUP_ALLOCATION into the
 112   linker script.
 113
 114 Changes in 2.28:
 115
 116 * The EXCLUDE_FILE linker script construct can now be applied outside of the
 117   section list in order for the exclusions to apply over all input sections in
 118   the list.
 119
 120 * Add support for the RISC-V architecture.
 121
 122 * The command-line option --no-eh-frame-hdr can now be used in ELF based
 123   linkers to disable the automatic generation of .eh_frame_hdr sections.
 124
 125 * Add --in-implib=<infile> to the ARM linker to enable specifying a set of
 126   Secure Gateway veneers that must exist in the output import library specified
 127   by --out-implib=<outfile> and the address they must have.  As such,
 128   --in-implib is only supported in combination with --cmse-implib.
 129
 130 * Extended the --out-implib=<file> option, previously restricted to x86 PE
 131   targets, to any ELF based target.  This allows the generation of an import
 132   library for an ELF executable, which can then be used by another application
 133   to link against the executable.
 134
 135 Changes in 2.27:
 136
 137 * Add a configure option --enable-relro to decide whether -z relro should
 138   be enabled in ELF linker by default.  Default to yes for all Linux
 139   targets except FRV, HPPA, IA64 and MIPS.  Note that -z relro can increase
 140   disk and memory size.
 141
 142 * Support for -z noreloc-overflow in the x86-64 ELF linker to disable
 143   relocation overflow check.
 144
 145 * Add -z common/-z nocommon options for ELF targets to control whether to
 146   convert common symbols to the STT_COMMON type during a relocatable link.
 147
 148 * Support for -z nodynamic-undefined-weak in the x86 ELF linker, which
 149   avoids dynamic relocations against undefined weak symbols in executable.
 150
 151 * The NOCROSSREFSTO command was added to the linker script language.
 152
 153 * Add --no-apply-dynamic-relocs to the AArch64 linker to do not apply link-time
 154   values for dynamic relocations.
 155
 156 Changes in 2.26:
 157
 158 * Add --fix-stm32l4xx-629360 to the ARM linker to enable a link-time
 159   workaround for a bug in the bus matrix / memory controller for some of
 160   the STM32 Cortex-M4 based products (STM32L4xx)
 161
 162 * Add a configure option --enable-compressed-debug-sections={all,ld} to
 163   decide whether DWARF debug sections should be compressed by default.
 164
 165 * Add support for the ARC EM/HS, and ARC600/700 architectures.
 166
 167 * Experimental support for linker garbage collection (--gc-sections)
 168   has been enabled for COFF and PE based targets.
 169
 170 * New command-line option for ELF targets to compress DWARF debug
 171   sections, --compress-debug-sections=[none|zlib|zlib-gnu|zlib-gabi].
 172
 173 * New command-line option, --orphan-handling=[place|warn|error|discard], to
 174   adjust how orphan sections are handled.  The default is 'place' which gives
 175   the current behaviour, 'warn' and 'error' issue a warning or error
 176   respectively when orphan sections are found, and 'discard' will discard all
 177   orphan sections.
 178
 179 * Add support for LLVM plugin.
 180
 181 * Add --print-memory-usage option to report memory blocks usage.
 182
 183 * Add --require-defined option, it's like --undefined except the new symbol
 184   must be defined by the end of the link.
 185
 186 Changes in 2.25:
 187
 188 * PE binaries now once again contain real timestamps by default.  To disable
 189   the inclusion of a timestamp in a PE binary, use the --no-insert-timestamp
 190   command-line option.
 191
 192 * Replace support for openrisc and or32 with support for or1k.
 193
 194 * Add support for the --build-id command-line option to COFF based targets.
 195
 196 * x86/x86_64 pe-coff now supports the --build-id option.
 197
 198 * Add support for the Andes NDS32.
 199
 200 Changes in 2.24:
 201
 202 * Add LOG2CEIL() builtin function to the linker script language
 203
 204 * Add support for the Texas Instruments MSP430X processor.
 205
 206 * Add support for Altera Nios II.
 207
 208 * Add support for the V850E3V5 architecture.
 209
 210 * Add support for the Imagination Technologies Meta processor.
 211
 212 * --enable-new-dtags no longer generates old dtags in addition to new dtags.
 213
 214 * Remove linker support for MIPS ECOFF targets.
 215
 216 * Add ALIGN_WITH_INPUT to the linker script language to force the alignment of
 217   an output section to use the maximum alignment of all its input sections.
 218
 219 Changes in 2.23:
 220
 221 * Enable compressed debug section feature for x86/x86_64 pe-coff.
 222
 223 * Add support for the 64-bit ARM architecture: AArch64.
 224
 225 * Added SORT_NONE to the linker script language to disable section sorting.
 226
 227 * Add a linker-provided symbol when producing ELF output, '__ehdr_start'
 228   to point to the ELF file header (and nearby program headers) in the
 229   program's memory image.
 230
 231 * Add support for S12X processor.
 232
 233 * Add support for the VLE extension to the PowerPC architecture.
 234
 235 * Add support for the Freescale XGATE architecture.
 236
 237 * Add option -f FILE on AIX (for response file).
 238
 239 * Add support for the Renesas RL78 architecture.
 240
 241 * Add support for the Adapteva EPIPHANY architecture.
 242
 243 Changes in 2.22:
 244
 245 * --copy-dt-needed-entries is no longer enabled by default.  Instead
 246   --no-copy-dt-needed-entries is the default.
 247
 248 * INPUT_SECTION_FLAGS has been added to the linker script language
 249   to allow selection of input sections by section header section flags.
 250
 251 * Add support for the Tilera TILEPro and TILE-Gx architectures.
 252
 253 * Added SORT_BY_INIT_PRIORITY to the linker script language to permit
 254   sorting sections by numerical value of the GCC init_priority attribute
 255   encoded in the section name.
 256
 257 Changes in 2.21:
 258
 259 * Linker script expression evaluation is somewhat more sane.  This may
 260   break scripts that depend on quirks of the old expression evaluation.
 261
 262 * Turn off underscoring for x86_64 PE+-COFF targets.  For old behavior the
 263   option --enable-leading-mingw64-underscores can be used on configure of
 264   bfd.
 265
 266 * Add support for the TMS320C6000 (TI C6X) processor family.
 267
 268 * --add-needed renamed to --copy-dt-needed-entries in order to avoid confusion
 269   with --as-needed option.
 270
 271 * Extend .def file syntax by '== <ID>' for imports and exports. This allows
 272   to alias the import/export table name written in PE image.
 273
 274 * Add --exclude-all-symbols option to PE based linkers.  This prevents all
 275   symbols from automatically being exported.
 276
 277 * Add support for the Renesas RX processor.
 278
 279 * Add support for alpha-vms target.
 280
 281 Changes in 2.20:
 282
 283 * GNU/Linux targets now support the STB_GNU_UNIQUE symbol binding.  This is a
 284   GNU extension to the standard set of ELF symbol bindings.  The binding will
 285   be passed on to the dynamic linker which will make sure that in the entire
 286   process there is just one symbol with the given name and type in use.
 287
 288 * PE targets now support a GNU extension to allow the alignment of common
 289   common symbols to be specified.  This support uses custom options in
 290   the .drectve section, which will be disregarded by the native tools.
 291
 292 * PE targets now add primitive support for ELF version scripts; symbols
 293   are not versioned, but the local and global symbol visibility directives
 294   are respected when filtering symbols in auto-export mode.
 295
 296 * New option --no-export-dynamic to undo the effect of the -E and
 297   --export-dynamic options.
 298
 299 * ELF: --warn-alternate-em option to warn if an object has alternate
 300   ELF machine code.
 301
 302 * New script function REGION_ALIAS to add alias names to memory regions.
 303
 304 * PE targets no longer make use of the long section names PE extension to
 305   the COFF format when generating executable images, by default.  The old
 306   (slightly non-conformant) behaviour can still be invoked by using the
 307   new '--enable-long-section-names' command-line option.  It is also enabled
 308   automatically in the presence of un-stripped debug information, as GDB
 309   needs to be able to find the debug info sections by their full names.
 310
 311 * For GNU/Linux systems the linker will now avoid processing any relocations
 312   made against symbols of the STT_GNU_IFUNC type and instead emit them into
 313   the resulting binary for processing by the loader.
 314
 315 * --as-needed now links in a dynamic library if it satisfies undefined
 316   symbols in regular objects, or in other dynamic libraries.  In the
 317   latter case the library is not linked if it is found in a DT_NEEDED
 318   entry of one of the libraries already linked.
 319
 320 * Add a new command-line option, -Ttext-segment ADDR, for ELF targets
 321   to set the address of the first byte of the text segment.
 322
 323 * Add support for Sunplus score architecture.
 324
 325 * Add new option --use-nul-prefixed-import-tables to ld for PE targets to
 326   allow fallback to old import table generation with null element prefix.
 327
 328 * Windows PE systems now support a new --exclude-modules-for-implib option,
 329   allowing users to partition object files and archive members between a DLL
 330   and its associated import library as they are generated during linking.
 331
 332 * Add support for Lattice Mico32 (lm32) architecture.
 333
 334 * Add CR16 ELF --embedded-relocs (used to embedded relocations into binaries
 335   for Embedded-PIC code) option.
 336
 337 * Add to the PE/PE+ targets the support of two different kinds of
 338   pseudo-relocations.  They can be selected by the switches
 339   --enable-runtime-pseudo-reloc-v1 and --enable-runtime-pseudo-reloc-v2.
 340   For the switch --enable-runtime-pseudo-reloc it uses for 32-bit
 341   runtime pseudo relocation version one, for 64-bit the version two.
 342
 343 Changes in 2.19:
 344
 345 * Linker scripts support a new INSERT command that makes it easier to
 346   augment the default script.
 347
 348 * Linker script input section filespecs may now specify a file within an
 349   archive by writing "archive:file".
 350
 351 * The --sort-common switch now has an optional argument which specifies the
 352   direction of sorting.
 353
 354 * The M68K linker now supports multiple GOT generation schemes controlled via
 355   the --got=<type> command-line option.
 356
 357 * The ARM EABI linker will now generate stubs for function calls to symbols
 358   that are too far away.  The placement of the stubs is controlled by a new
 359   linker command-line option: --stub-group-size=N.
 360
 361 Changes in 2.18:
 362
 363 * Linker sources now released under version 3 of the GNU General Public
 364   License.
 365
 366 * ELF: New --build-id option to generate a unique per-binary identifier
 367   embedded in a note section.
 368
 369 * Added support for National Semicondutor CompactRISC (ie CR16) target.
 370
 371 * -l:foo now searches the library path for a filename called foo,
 372   without converting it to libfoo.a or libfoo.so.
 373
 374 * Add a new command-line option '--default-script=FILE' or '-dT FILE'
 375   which specifies a replacement for the built in, default linker
 376   script.
 377
 378 * ELF: Add -Bsymbolic-functions, --dynamic-list-cpp-new, which puts C++
 379   operator new and delete on the dynamic list, and --dynamic-list-data,
 380   builtin list for --dynamic-list, which puts global data symbols on the
 381   dynamic list.
 382
 383 * Add support for x86_64 PE+ target.
 384
 385 * Add support for Score target.
 386
 387 * ELF: Add --dynamic-list option to specify a list of global symbols
 388   whose references shouldn't be bound to the definition within the
 389   shared library, or a list of symbols which should be added to the
 390   symbol table in the executable.
 391
 392 * The default output section LMA has changed for allocatable sections from
 393   being equal to VMA, to keeping the difference between LMA and VMA the same as
 394   the previous output section in the same region.  This is a more useful
 395   default when using overlays and other cases where you specify an LMA
 396   differing from the VMA for some sections.
 397
 398 * New switch: --print-gc-sections to list any sections removed by garabge
 399   collection.
 400
 401 * ARM: Added --vfp11-denorm-fix option to work around an erratum in current
 402   VFP11 coprocessors.
 403
 404 Changes in 2.17:
 405
 406 * Support for the Infineon XC16X has been added by KPIT Cummins Infosystems.
 407
 408 * Modify the Linux linker search order to better match ld.so search order.
 409   Look for DT_NEEDED libraries in paths specified by ld.so.conf before
 410   searching the default directories, rather than vice versa.
 411   Use $prefix/etc/ld.so.conf if it exists, otherwise /etc/ld.so.conf.
 412
 413 * PE-COFF: Forward exports from DLL's can now be specified in .def files
 414   passed directly to ld.
 415
 416 * Support for the Z80 processor family has been added.
 417
 418 * Add support for the "@<file>" syntax to the command line, so that extra
 419   switches can be read from <file>.
 420
 421 Changes in 2.16:
 422
 423 * Support for the R_ARM_V4BX relocation as defined in the ARM AAELF
 424   specification has been added via the --fix-v4bx command-line option.
 425
 426 * New linker script construct AS_NEEDED(), which sets the --as-needed flag
 427   for input files listed inside of it.
 428
 429 * A new command-line option, --sysroot, can be used to override the
 430   default sysroot location.  It only applies to toolchains that were
 431   configured using --with-sysroot.
 432
 433 * New linker script functions: ORIGIN() and LENGTH() which return information
 434   about a specified memory region.
 435
 436 * Port to MAXQ processor contributed by HCL Tech.
 437
 438 * Added SEGMENT_START to the linker script language to permit the user to
 439   override the base address for a segment from the command-line.
 440
 441 * ELF: --warn-shared-textrel option to warn if adding a DT_TEXTREL to a shared
 442   object.
 443
 444 * Added SORT_BY_NAME and SORT_BY_ALIGNMENT to the linker script
 445   language to permit sorting sections by section name or section
 446   maximum alignment.
 447
 448 * Added a new linker command-line switch, --sort-section name|alignment,
 449   to sort sections by section name or maximum alignment.
 450
 451 * ELF: --add-needed/--no-add-needed options to control if a DT_NEEDED tag
 452   should be added when a shared library comes from DT_NEEDED tags.
 453
 454 * Support for the crx-elf target added.
 455
 456 * Support for the sh-symbianelf target added.
 457
 458 * A new linker command-line switch has been added which allows the hash table
 459   size to be set to a suitable prime value near to its argument.  This switch
 460   is --hash-size=<NUMBER>.  Also if the switch --reduce-memory-overheads is
 461   used, and --hash-size has not been used, then the default value will be set
 462   to 1021.
 463
 464 * Linker map files are now generated with an O(N) algorithm for finding symbols
 465   that are defined in each section.  This uses about 40% more memory for
 466   symbols than the old O(N^2) algorithm.  You can use the new
 467   --reduce-memory-overheads option to select the old algorithm; this option
 468   might also be used in the future to select similar tradeoffs.
 469
 470 Changes in 2.15:
 471
 472 * ELF: --as-needed/--no-as-needed options to control if a DT_NEEDED tag should
 473   be added only when a shared library is referenced.
 474
 475 * PE: --large-address-aware option to indicate executables support virtual
 476   addresses greater than 2 gigabytes.
 477
 478 * DWARF 2 support for i386pe added.
 479
 480 * The linker script operator DEFINED() will now yield 1 only for a symbol that
 481   is defined before the statement where DEFINED is used.
 482
 483 * The MIPS --embedded-relocs (used to embed relocations into binaries for
 484   Embedded-PIC code) is deprecated and will be removed in a future release.
 485
 486 * cr16c support added by NSC.
 487
 488 * m32r Linux (ELF) support added by Renesas.
 489
 490 * Improved linker's handling of unresolved symbols.  The switch
 491   --unresolved-symbols=<method> has been added to tell the linker when it
 492   should report them and the switch --warn-unresolved-symbols has been added to
 493   make reports be issued as warning messages rather than errors.
 494
 495 Changes in 2.14:
 496
 497 * Added support for Xtensa architecture.
 498
 499 * Added --with-sysroot configure switch to specify a target system root, for
 500   linking against a target filesystem image.
 501
 502 * Added --accept-unknown-linker-format to restore old linker behaviour (pre
 503   2.14) of silently accepting and linking in any files in an unknown binary
 504   file format.
 505
 506 * Added --no-omagic to undo the effects of the -N option.
 507
 508 * Support for Texas Instruments TMS320C4x and TMS320C3x series of
 509   DSP's contributed by Michael Hayes and Svein E. Seldal.
 510
 511 * Added --with-lib-path configure switch to specify default value for
 512   LIB_PATH.
 513
 514 * ARM port to QNX operating system added by Graeme Peterson.
 515
 516 * IP2K support added by Denis Chertykov.
 517
 518 Changes in 2.13:
 519
 520 * Support for the Fujitsu FRV architecture added by Red Hat. Models for FR400
 521   and FR500 included.
 522
 523 Changes in version 2.13:
 524
 525 * DEC VAX ELF support, by Matt Thomas.
 526
 527 Changes in version 2.12:
 528
 529 * Support for Don Knuth's MMIX, by Hans-Peter Nilsson.
 530
 531 * Support for the OpenRISC 32-bit embedded processor by OpenCores.
 532
 533 * Support for -z nocopyreloc in the x86 ELF linker, which disables
 534   production of copy relocs.  Warning: using this option may result in
 535   non-sharable applications.
 536
 537 * Support for -z combreloc in the ELF linker, which puts dynamic
 538   relocations against the same symbol together, so that dynamic linker
 539   can use an one-entry symbol lookup cache.
 540
 541 * Support for ELF SHF_MERGE section merging, by Jakub Jelinek.
 542
 543 Changes in version 2.11:
 544
 545 * Support for AMD x86-64 architecture, by Jan Hubicka, SuSE Labs.
 546
 547 * Support added for eliminating duplicate DWARF2 debug information by
 548   having the compiler generate the information in sections called
 549   .gnu.linkonce.wi.XXXX where XXXX is a checksum for the contents.  The
 550   linker then merges these sections together into the normal .debug_info
 551   section.
 552
 553 * The native ELF linker now searches the directories in DT_RUNPATH or
 554   DT_RPATH of a shared library for shared libraries needed by it.
 555
 556 * TI C54x support, by Timothy Wall.
 557
 558 * Added command-line switch --section-start to set the start address of any
 559   specified section.
 560
 561 * Added ability to emit full relocation information in linked executables,
 562   enabled by --emit-relocs.  Some post-linkage optimization tools need
 563   this information in order to be able to correctly identify and perform
 564   symbol relative addressing in the event of changes in section contents
 565   (instructions being added or deleted, extending data sections, etc.)
 566
 567 * Support for i860, by Jason Eckhardt (preliminary, alpha quality).
 568
 569 * Support for CRIS (Axis Communications ETRAX series).
 570
 571 * Support for PDP-11 and 2.11BSD a.out format, by Lars Brinkhoff.
 572
 573 Changes in version 2.10:
 574
 575 * Added AT> to the linker script language to allow load-time allocation of
 576   sections into regions.
 577
 578 * Added garbage collection of unused sections, enabled by --gc-sections.
 579   It does require a bit of backend support; currently implemented are
 580   arm-elf, avr-elf, d10v-elf, fr30-elf, i386-elf, m32r-elf, m68k-elf,
 581   mcore-elf, mips-elf, mn10300-elf, ppc-elf, sh-elf, sparc-elf, and v850-elf.
 582   Others will ignore the option.
 583
 584 * Added SORT to the linker script language to permit sorting sections by file
 585   name or section name.
 586
 587 * Added EXTERN to the linker script language as an equivalent to the -u
 588   command-line option.
 589
 590 * Added ASSERT to the linker script language.
 591
 592 * Added EXCLUDE_FILE to the linker script language for further control over
 593   wildcard file names.
 594
 595 * Added -O option to optimize linker output (as of this writing, this only
 596   affects ELF shared library generation).
 597
 598 * The -e option now accepts a number as well as a symbol name.
 599
 600 * Added --no-undefined option to disallow undefined symbols when creating a
 601   shared library.
 602
 603 * The linker now issues a warning, not an error, for an undefined symbol when
 604   using -Bsymbolic; use the new --no-undefined option to get the old
 605   behaviour.
 606
 607 * Added --demangle and --no-demangle options.
 608
 609 Changes in version 2.9:
 610
 611 * Added SQUAD to the linker script language.
 612
 613 * New option --no-warn-mismatch.
 614
 615 * The MEMORY command now parses the attributes to determine where sections that
 616   are not placed in a specific memory region are placed.
 617
 618 Changes in version 2.8:
 619
 620 * Linker scripts may now contain shell wildcard characters for file and section
 621   names.
 622
 623 * The linker now supports symbol versions in ELF.
 624
 625 * The NOCROSSREFS command was added to the linker script language.
 626
 627 * The LOADADDR expression was added to the linker script language.
 628
 629 * MAX and MIN functions were added to the linker script language.
 630
 631 * The OVERLAY construct was added to the linker script language.
 632
 633 * New option --warn-section-align to warn when the address of an output section
 634   changes due to alignment of an input section.
 635
 636 * New options --filter/-F and --auxiliary/-f.
 637
 638 Changes in version 2.7:
 639
 640 * New option --cref to print out a cross reference table.
 641
 642 * New option --wrap SYMBOL.
 643
 644 * New option --no-whole-archive, to turn off the effect of --whole-archive.
 645
 646 * Input sections assigned to the output section /DISCARD/ in the linker script
 647   are not included in the output file.
 648
 649 * The SunOS and ELF linkers now merge stabs debugging information which uses
 650   the N_BINCL and N_EINCL stab types.  This reduces the amount of debugging
 651   information generated.
 652
 653 Changes in version 2.6:
 654
 655 * When an ELF section name is representable as a C identifier (this is not true
 656 of most ELF section names), the linker will automatically define symbols
 657 __start_SECNAME and __stop_SECNAME, where SECNAME is the section name, at the
 658 beginning and the end of the section.  This is used by glibc.
 659
 660   Addendum: Current versions of the linker (at least for version 2.18 onwards
 661 and possibly much earlier as well) place two restrictions on this feature:  The
 662 symbols are only implemented for orphaned sections, not for explicitly placed
 663 sections and they are PROVIDEd rather than being defined.
 664
 665 * When an ELF section named .gnu.warning is encountered in an input file, the
 666 contents of the section are displayed as an error message, and the section is
 667 not copied into the output file.  This is used by glibc.
 668
 669 * When an ELF section named .gnu.warning.SYMBOL is encountered in an input
 670 file, and the symbol SYMBOL is referenced by some object file, the contents of
 671 the section are displayed as an error message.  The section is not copied into
 672 the output file, unless doing a relocatable or shared link.  This is used by
 673 glibc.
 674
 675 * New options -split-by-reloc and -split-by-file.
 676
 677 * The linker now supports linking PIC compiled code on SPARC SunOS.  It can
 678 also create SPARC SunOS shared libraries, and, like the native SunOS linker,
 679 will do so whenever there is an undefined symbol in the link and neither the -e
 680 nor the -r option was used.
 681
 682 * The -rpath option may be used on SunOS to set the list of directories to be
 683 searched at run time.  This overrides the default of building the list from the
 684 -L options.
 685
 686 * The COFF linker now combines debugging information for structs, unions, and
 687 enums, so that even if the same type is defined in multiple input files it will
 688 only be defined once in the output file.  The --traditional-format switch will
 689 prevent this optimization.
 690
 691 Changes in version 2.5:
 692
 693 * The linker now supports linking against SunOS shared libraries.  It still can
 694 not link SunOS PIC (Position Independent Code) files, so it can not be used to
 695 generate shared libraries.
 696
 697 * The linker now supports linking against ELF shared libraries for the i386
 698 (UnixWare) and SPARC (Solaris).  It can also link ELF PIC files, and can be
 699 used to generate shared libraries.  Shared library generation is not well
 700 tested; please report any problems encountered.  The linker is now enabled for
 701 Solaris again.
 702
 703 * Eric Youngdale has contributed Linux support code, including linking against
 704 Linux a.out shared libraries.  The linker produces Linux QMAGIC binaries.
 705
 706 * The ELF backend has been converted to the new linker code.  To use the new
 707 ELF linker, each particular target requires a relocation function.  So far,
 708 this function has been written for i386 (UnixWare), SPARC (Solaris) MIPS (Irix
 709 5), and HPPA ELF targets.
 710
 711 * The -( (--start-group) and -) (--end-group) options have been added to
 712 support searching a group of archives as though they were a single archive.
 713 This can also be used in a linker script, as GROUP ( files ).
 714
 715 * When a file is named on the command line, and the linker does not recognize
 716 it as an object file, the linker will now treat the file as a linker script
 717 file.  A linker script named in this way augments, but does not replace, the
 718 default linker script.
 719
 720 * The -warn-once option was added.  It causes the linker to only warn once per
 721 undefined symbol, rather than once per reference.
 722
 723 * The COFF backend has been converted to the new linker code.  As with ELF, to
 724 use the new linker, each particular target requires a relocation function.  So
 725 far, this function has been written for the i386, m68k, a29k and SH targets.
 726
 727 * The -V flag was made a synonym for -v, for SVR4 compatibility.  The old -V
 728 behaviour is available via --verbose.
 729
 730 Changes in version 2.4:
 731
 732 * New linker code, by Steve Chamberlain and Ian Taylor.  For a.out and ecoff
 733   formats (so far), this should result in considerable savings in time
 734   and memory used while linking; slightly poorer performance than
 735   before for formats not converted yet.
 736
 737 * Command-line parsing is no longer done with flex.  This means
 738   oddball characters in filenames won't get treated as argument
 739   separators.
 740
 741 * HP-PA ELF support, by Jeff Law.  (No SOM support yet.)
 742
 743 * Mach i386 support, by David Mackenzie.
 744
 745 * Irix 4 shared libraries are now supported (Irix 5 uses ELF, and ELF shared
 746   libraries are not yet supported).
 747
 748 * COFF shared libraries (as on SCO) should work as well.
 749
 750 * The linker is disabled for Solaris.  (Actually, it was in 2.3 also, I just
 751   forgot to note it.)  Some of their C library routines don't work when
 752   statically linked, and the GNU linker doesn't support dynamic linking yet.
 753
 754 Changes in version 2.3:
 755
 756 * Weak symbols are now supported.
 757
 758 * ELF support has been added.  The linker has been bootstrapped on
 759   UnixWare and Solaris.
 760
 761 * Alpha OSF/1 support has been added (non dynamic linking only).
 762
 763 Changes in version 2.2:
 764
 765 * The `bfd' library has been updated to reduce a.out-format string
 766   table size.  The effect of this is that files linked from many input
 767   files with duplicate symbols (`-g' debugging records, or identical
 768   static symbols) should be much smaller.
 769
 770 Changes in version 2.1:
 771
 772 * The ld -ySYMBOL flag (to trace references to SYMBOL) is now implemented.
 773
 774 * There is now support for writing ECOFF files, so ld and the
 775   other utilities should work on Risc/Ultrix and Irix.
 776
 777 \f
 778 Copyright (C) 2012-2020 Free Software Foundation, Inc.
 779
 780 Copying and distribution of this file, with or without modification,
 781 are permitted in any medium without royalty provided the copyright
 782 notice and this notice are preserved.
 783
 784 Local variables:
 785 fill-column: 79
 786 End: