ld/NEWS

   1 -*- text -*-
   2
   3 Changes in 2.33:
   4
   5 * Add command-line option --no-print-map-discarded.
   6
   7 * The Cortex-A53 Erratum 843419 workaround now supports a choice of which
   8   workaround to use.  The option --fix-cortex-a53-843419 now takes an
   9   optional argument --fix-cortex-a53-843419[=full|adr|adrp] which can be
  10   used to force a particular workaround to be used.  See --help for AArch64
  11   for more details.
  12
  13 * Add target handlers for AArch64 for ELF GNU program properties.
  14
  15 * Add support for GNU_PROPERTY_AARCH64_FEATURE_1_BTI in ELF GNU program
  16   properties in the AArch64 ELF linker.
  17
  18 * Add support for GNU_PROPERTY_AARCH64_FEATURE_1_PAC in ELF GNU program
  19   properties in the AArch64 ELF linker.
  20
  21 * Add -z force-bti for AArch64 to enable GNU_PROPERTY_AARCH64_FEATURE_1_BTI
  22   on output while warning about missing GNU_PROPERTY_AARCH64_FEATURE_1_BTI
  23   on inputs and use PLTs protected with BTI.
  24
  25 * Add -z pac-plt for AArch64 to pick PAC enabled PLTs.
  26
  27 Changes in 2.32:
  28
  29 * Report property change in linker map file when merging GNU properties.
  30
  31 * Add support for the C-SKY processor series.
  32
  33 * -t now doesn't report members within archives, unless -t is given twice.
  34   A single -t is now more useful when generating a list of files that should be
  35   packaged for a linker bug report.  For example:
  36     gcc hello.c -save-temps -Wl,-t | xargs realpath | sort | uniq > files
  37     tar cJf test.tar.xz `cat files`
  38
  39 Changes in 2.31:
  40
  41 * Speed up direct linking with DLLs for Cygwin and Mingw targets.
  42
  43 * Add a configure option --enable-separate-code to decide whether
  44   -z separate-code should be enabled in ELF linker by default.  Default
  45   to yes for Linux/x86 targets.  Note that -z separate-code can increase
  46   disk and memory size.
  47
  48 Changes in 2.30:
  49
  50 * Add -z separate-code to generate separate code PT_LOAD segment.
  51
  52 * Add "-z undefs" command-line option as the inverse of the "-z defs" option.
  53
  54 * Add -z globalaudit command-line option to force audit libraries to be run
  55   for every dynamic object loaded by an executable - provided that the loader
  56   supports this functionality.
  57
  58 * Tighten linker script grammar around file name specifiers to prevent the use
  59   of SORT_BY_ALIGNMENT and SORT_BY_INIT_PRIORITY on filenames.  These would
  60   previously be accepted but had no effect.
  61
  62 * The EXCLUDE_FILE directive can now be placed within any SORT_* directive
  63   within input section lists.
  64
  65 Changes in 2.29:
  66
  67 * Support for -z shstk in the x86 ELF linker to generate
  68   GNU_PROPERTY_X86_FEATURE_1_SHSTK in ELF GNU program properties.
  69
  70 * Add support for GNU_PROPERTY_X86_FEATURE_1_SHSTK in ELF GNU program
  71   properties in the x86 ELF linker.
  72
  73 * Add support for GNU_PROPERTY_X86_FEATURE_1_IBT in ELF GNU program
  74   properties in the x86 ELF linker.
  75
  76 * Support for -z ibtplt in the x86 ELF linker to generate IBT-enabled
  77   PLT.
  78
  79 * Support for -z ibt in the x86 ELF linker to generate IBT-enabled
  80   PLT as well as GNU_PROPERTY_X86_FEATURE_1_IBT in ELF GNU program
  81   properties.
  82
  83 * Add support for ELF SHF_GNU_MBIND and PT_GNU_MBIND_XXX.
  84
  85 * Add support for ELF GNU program properties.
  86
  87 * Add support for the Texas Instruments PRU processor.
  88
  89 * When configuring for arc*-*-linux* targets the default linker emulation will
  90   change if --with-cpu=nps400 is used at configure time.
  91
  92 * Improve assignment of LMAs to orphan sections in some edge cases where a
  93   mixture of both AT>LMA_REGION and AT(LMA) are used.
  94
  95 * Orphan sections placed after an empty section that has an AT(LMA) will now
  96   take an load memory address starting from LMA.
  97
  98 * Section groups can now be resolved (the group deleted and the group members
  99   placed like normal sections) at partial link time either using the new linker
 100   option --force-group-allocation or by placing FORCE_GROUP_ALLOCATION into the
 101   linker script.
 102
 103 Changes in 2.28:
 104
 105 * The EXCLUDE_FILE linker script construct can now be applied outside of the
 106   section list in order for the exclusions to apply over all input sections in
 107   the list.
 108
 109 * Add support for the RISC-V architecture.
 110
 111 * The command-line option --no-eh-frame-hdr can now be used in ELF based
 112   linkers to disable the automatic generation of .eh_frame_hdr sections.
 113
 114 * Add --in-implib=<infile> to the ARM linker to enable specifying a set of
 115   Secure Gateway veneers that must exist in the output import library specified
 116   by --out-implib=<outfile> and the address they must have.  As such,
 117   --in-implib is only supported in combination with --cmse-implib.
 118
 119 * Extended the --out-implib=<file> option, previously restricted to x86 PE
 120   targets, to any ELF based target.  This allows the generation of an import
 121   library for an ELF executable, which can then be used by another application
 122   to link against the executable.
 123
 124 Changes in 2.27:
 125
 126 * Add a configure option --enable-relro to decide whether -z relro should
 127   be enabled in ELF linker by default.  Default to yes for all Linux
 128   targets except FRV, HPPA, IA64 and MIPS.  Note that -z relro can increase
 129   disk and memory size.
 130
 131 * Support for -z noreloc-overflow in the x86-64 ELF linker to disable
 132   relocation overflow check.
 133
 134 * Add -z common/-z nocommon options for ELF targets to control whether to
 135   convert common symbols to the STT_COMMON type during a relocatable link.
 136
 137 * Support for -z nodynamic-undefined-weak in the x86 ELF linker, which
 138   avoids dynamic relocations against undefined weak symbols in executable.
 139
 140 * The NOCROSSREFSTO command was added to the linker script language.
 141
 142 * Add --no-apply-dynamic-relocs to the AArch64 linker to do not apply link-time
 143   values for dynamic relocations.
 144
 145 Changes in 2.26:
 146
 147 * Add --fix-stm32l4xx-629360 to the ARM linker to enable a link-time
 148   workaround for a bug in the bus matrix / memory controller for some of
 149   the STM32 Cortex-M4 based products (STM32L4xx)
 150
 151 * Add a configure option --enable-compressed-debug-sections={all,ld} to
 152   decide whether DWARF debug sections should be compressed by default.
 153
 154 * Add support for the ARC EM/HS, and ARC600/700 architectures.
 155
 156 * Experimental support for linker garbage collection (--gc-sections)
 157   has been enabled for COFF and PE based targets.
 158
 159 * New command-line option for ELF targets to compress DWARF debug
 160   sections, --compress-debug-sections=[none|zlib|zlib-gnu|zlib-gabi].
 161
 162 * New command-line option, --orphan-handling=[place|warn|error|discard], to
 163   adjust how orphan sections are handled.  The default is 'place' which gives
 164   the current behaviour, 'warn' and 'error' issue a warning or error
 165   respectively when orphan sections are found, and 'discard' will discard all
 166   orphan sections.
 167
 168 * Add support for LLVM plugin.
 169
 170 * Add --print-memory-usage option to report memory blocks usage.
 171
 172 * Add --require-defined option, it's like --undefined except the new symbol
 173   must be defined by the end of the link.
 174
 175 Changes in 2.25:
 176
 177 * PE binaries now once again contain real timestamps by default.  To disable
 178   the inclusion of a timestamp in a PE binary, use the --no-insert-timestamp
 179   command-line option.
 180
 181 * Replace support for openrisc and or32 with support for or1k.
 182
 183 * Add support for the --build-id command-line option to COFF based targets.
 184
 185 * x86/x86_64 pe-coff now supports the --build-id option.
 186
 187 * Add support for the Andes NDS32.
 188
 189 Changes in 2.24:
 190
 191 * Add LOG2CEIL() builtin function to the linker script language
 192
 193 * Add support for the Texas Instruments MSP430X processor.
 194
 195 * Add support for Altera Nios II.
 196
 197 * Add support for the V850E3V5 architecture.
 198
 199 * Add support for the Imagination Technologies Meta processor.
 200
 201 * --enable-new-dtags no longer generates old dtags in addition to new dtags.
 202
 203 * Remove linker support for MIPS ECOFF targets.
 204
 205 * Add ALIGN_WITH_INPUT to the linker script language to force the alignment of
 206   an output section to use the maximum alignment of all its input sections.
 207
 208 Changes in 2.23:
 209
 210 * Enable compressed debug section feature for x86/x86_64 pe-coff.
 211
 212 * Add support for the 64-bit ARM architecture: AArch64.
 213
 214 * Added SORT_NONE to the linker script language to disable section sorting.
 215
 216 * Add a linker-provided symbol when producing ELF output, '__ehdr_start'
 217   to point to the ELF file header (and nearby program headers) in the
 218   program's memory image.
 219
 220 * Add support for S12X processor.
 221
 222 * Add support for the VLE extension to the PowerPC architecture.
 223
 224 * Add support for the Freescale XGATE architecture.
 225
 226 * Add option -f FILE on AIX (for response file).
 227
 228 * Add support for the Renesas RL78 architecture.
 229
 230 * Add support for the Adapteva EPIPHANY architecture.
 231
 232 Changes in 2.22:
 233
 234 * --copy-dt-needed-entries is no longer enabled by default.  Instead
 235   --no-copy-dt-needed-entries is the default.
 236
 237 * INPUT_SECTION_FLAGS has been added to the linker script language
 238   to allow selection of input sections by section header section flags.
 239
 240 * Add support for the Tilera TILEPro and TILE-Gx architectures.
 241
 242 * Added SORT_BY_INIT_PRIORITY to the linker script language to permit
 243   sorting sections by numerical value of the GCC init_priority attribute
 244   encoded in the section name.
 245
 246 Changes in 2.21:
 247
 248 * Linker script expression evaluation is somewhat more sane.  This may
 249   break scripts that depend on quirks of the old expression evaluation.
 250
 251 * Turn off underscoring for x86_64 PE+-COFF targets.  For old behavior the
 252   option --enable-leading-mingw64-underscores can be used on configure of
 253   bfd.
 254
 255 * Add support for the TMS320C6000 (TI C6X) processor family.
 256
 257 * --add-needed renamed to --copy-dt-needed-entries in order to avoid confusion
 258   with --as-needed option.
 259
 260 * Extend .def file syntax by '== <ID>' for imports and exports. This allows
 261   to alias the import/export table name written in PE image.
 262
 263 * Add --exclude-all-symbols option to PE based linkers.  This prevents all
 264   symbols from automatically being exported.
 265
 266 * Add support for the Renesas RX processor.
 267
 268 * Add support for alpha-vms target.
 269
 270 Changes in 2.20:
 271
 272 * GNU/Linux targets now support the STB_GNU_UNIQUE symbol binding.  This is a
 273   GNU extension to the standard set of ELF symbol bindings.  The binding will
 274   be passed on to the dynamic linker which will make sure that in the entire
 275   process there is just one symbol with the given name and type in use.
 276
 277 * PE targets now support a GNU extension to allow the alignment of common
 278   common symbols to be specified.  This support uses custom options in
 279   the .drectve section, which will be disregarded by the native tools.
 280
 281 * PE targets now add primitive support for ELF version scripts; symbols
 282   are not versioned, but the local and global symbol visibility directives
 283   are respected when filtering symbols in auto-export mode.
 284
 285 * New option --no-export-dynamic to undo the effect of the -E and
 286   --export-dynamic options.
 287
 288 * ELF: --warn-alternate-em option to warn if an object has alternate
 289   ELF machine code.
 290
 291 * New script function REGION_ALIAS to add alias names to memory regions.
 292
 293 * PE targets no longer make use of the long section names PE extension to
 294   the COFF format when generating executable images, by default.  The old
 295   (slightly non-conformant) behaviour can still be invoked by using the
 296   new '--enable-long-section-names' command-line option.  It is also enabled
 297   automatically in the presence of un-stripped debug information, as GDB
 298   needs to be able to find the debug info sections by their full names.
 299
 300 * For GNU/Linux systems the linker will now avoid processing any relocations
 301   made against symbols of the STT_GNU_IFUNC type and instead emit them into
 302   the resulting binary for processing by the loader.
 303
 304 * --as-needed now links in a dynamic library if it satisfies undefined
 305   symbols in regular objects, or in other dynamic libraries.  In the
 306   latter case the library is not linked if it is found in a DT_NEEDED
 307   entry of one of the libraries already linked.
 308
 309 * Add a new command-line option, -Ttext-segment ADDR, for ELF targets
 310   to set the address of the first byte of the text segment.
 311
 312 * Add support for Sunplus score architecture.
 313
 314 * Add new option --use-nul-prefixed-import-tables to ld for PE targets to
 315   allow fallback to old import table generation with null element prefix.
 316
 317 * Windows PE systems now support a new --exclude-modules-for-implib option,
 318   allowing users to partition object files and archive members between a DLL
 319   and its associated import library as they are generated during linking.
 320
 321 * Add support for Lattice Mico32 (lm32) architecture.
 322
 323 * Add CR16 ELF --embedded-relocs (used to embedded relocations into binaries
 324   for Embedded-PIC code) option.
 325
 326 * Add to the PE/PE+ targets the support of two different kinds of
 327   pseudo-relocations.  They can be selected by the switches
 328   --enable-runtime-pseudo-reloc-v1 and --enable-runtime-pseudo-reloc-v2.
 329   For the switch --enable-runtime-pseudo-reloc it uses for 32-bit
 330   runtime pseudo relocation version one, for 64-bit the version two.
 331
 332 Changes in 2.19:
 333
 334 * Linker scripts support a new INSERT command that makes it easier to
 335   augment the default script.
 336
 337 * Linker script input section filespecs may now specify a file within an
 338   archive by writing "archive:file".
 339
 340 * The --sort-common switch now has an optional argument which specifies the
 341   direction of sorting.
 342
 343 * The M68K linker now supports multiple GOT generation schemes controlled via
 344   the --got=<type> command-line option.
 345
 346 * The ARM EABI linker will now generate stubs for function calls to symbols
 347   that are too far away.  The placement of the stubs is controlled by a new
 348   linker command-line option: --stub-group-size=N.
 349
 350 Changes in 2.18:
 351
 352 * Linker sources now released under version 3 of the GNU General Public
 353   License.
 354
 355 * ELF: New --build-id option to generate a unique per-binary identifier
 356   embedded in a note section.
 357
 358 * Added support for National Semicondutor CompactRISC (ie CR16) target.
 359
 360 * -l:foo now searches the library path for a filename called foo,
 361   without converting it to libfoo.a or libfoo.so.
 362
 363 * Add a new command-line option '--default-script=FILE' or '-dT FILE'
 364   which specifies a replacement for the built in, default linker
 365   script.
 366
 367 * ELF: Add -Bsymbolic-functions, --dynamic-list-cpp-new, which puts C++
 368   operator new and delete on the dynamic list, and --dynamic-list-data,
 369   builtin list for --dynamic-list, which puts global data symbols on the
 370   dynamic list.
 371
 372 * Add support for x86_64 PE+ target.
 373
 374 * Add support for Score target.
 375
 376 * ELF: Add --dynamic-list option to specify a list of global symbols
 377   whose references shouldn't be bound to the definition within the
 378   shared library, or a list of symbols which should be added to the
 379   symbol table in the executable.
 380
 381 * The default output section LMA has changed for allocatable sections from
 382   being equal to VMA, to keeping the difference between LMA and VMA the same as
 383   the previous output section in the same region.  This is a more useful
 384   default when using overlays and other cases where you specify an LMA
 385   differing from the VMA for some sections.
 386
 387 * New switch: --print-gc-sections to list any sections removed by garabge
 388   collection.
 389
 390 * ARM: Added --vfp11-denorm-fix option to work around an erratum in current
 391   VFP11 coprocessors.
 392
 393 Changes in 2.17:
 394
 395 * Support for the Infineon XC16X has been added by KPIT Cummins Infosystems.
 396
 397 * Modify the Linux linker search order to better match ld.so search order.
 398   Look for DT_NEEDED libraries in paths specified by ld.so.conf before
 399   searching the default directories, rather than vice versa.
 400   Use $prefix/etc/ld.so.conf if it exists, otherwise /etc/ld.so.conf.
 401
 402 * PE-COFF: Forward exports from DLL's can now be specified in .def files
 403   passed directly to ld.
 404
 405 * Support for the Z80 processor family has been added.
 406
 407 * Add support for the "@<file>" syntax to the command line, so that extra
 408   switches can be read from <file>.
 409
 410 Changes in 2.16:
 411
 412 * Support for the R_ARM_V4BX relocation as defined in the ARM AAELF
 413   specification has been added via the --fix-v4bx command-line option.
 414
 415 * New linker script construct AS_NEEDED(), which sets the --as-needed flag
 416   for input files listed inside of it.
 417
 418 * A new command-line option, --sysroot, can be used to override the
 419   default sysroot location.  It only applies to toolchains that were
 420   configured using --with-sysroot.
 421
 422 * New linker script functions: ORIGIN() and LENGTH() which return information
 423   about a specified memory region.
 424
 425 * Port to MAXQ processor contributed by HCL Tech.
 426
 427 * Added SEGMENT_START to the linker script language to permit the user to
 428   override the base address for a segment from the command-line.
 429
 430 * ELF: --warn-shared-textrel option to warn if adding a DT_TEXTREL to a shared
 431   object.
 432
 433 * Added SORT_BY_NAME and SORT_BY_ALIGNMENT to the linker script
 434   language to permit sorting sections by section name or section
 435   maximum alignment.
 436
 437 * Added a new linker command-line switch, --sort-section name|alignment,
 438   to sort sections by section name or maximum alignment.
 439
 440 * ELF: --add-needed/--no-add-needed options to control if a DT_NEEDED tag
 441   should be added when a shared library comes from DT_NEEDED tags.
 442
 443 * Support for the crx-elf target added.
 444
 445 * Support for the sh-symbianelf target added.
 446
 447 * A new linker command-line switch has been added which allows the hash table
 448   size to be set to a suitable prime value near to its argument.  This switch
 449   is --hash-size=<NUMBER>.  Also if the switch --reduce-memory-overheads is
 450   used, and --hash-size has not been used, then the default value will be set
 451   to 1021.
 452
 453 * Linker map files are now generated with an O(N) algorithm for finding symbols
 454   that are defined in each section.  This uses about 40% more memory for
 455   symbols than the old O(N^2) algorithm.  You can use the new
 456   --reduce-memory-overheads option to select the old algorithm; this option
 457   might also be used in the future to select similar tradeoffs.
 458
 459 Changes in 2.15:
 460
 461 * ELF: --as-needed/--no-as-needed options to control if a DT_NEEDED tag should
 462   be added only when a shared library is referenced.
 463
 464 * PE: --large-address-aware option to indicate executables support virtual
 465   addresses greater than 2 gigabytes.
 466
 467 * DWARF 2 support for i386pe added.
 468
 469 * The linker script operator DEFINED() will now yield 1 only for a symbol that
 470   is defined before the statement where DEFINED is used.
 471
 472 * The MIPS --embedded-relocs (used to embed relocations into binaries for
 473   Embedded-PIC code) is deprecated and will be removed in a future release.
 474
 475 * cr16c support added by NSC.
 476
 477 * m32r Linux (ELF) support added by Renesas.
 478
 479 * Improved linker's handling of unresolved symbols.  The switch
 480   --unresolved-symbols=<method> has been added to tell the linker when it
 481   should report them and the switch --warn-unresolved-symbols has been added to
 482   make reports be issued as warning messages rather than errors.
 483
 484 Changes in 2.14:
 485
 486 * Added support for Xtensa architecture.
 487
 488 * Added --with-sysroot configure switch to specify a target system root, for
 489   linking against a target filesystem image.
 490
 491 * Added --accept-unknown-linker-format to restore old linker behaviour (pre
 492   2.14) of silently accepting and linking in any files in an unknown binary
 493   file format.
 494
 495 * Added --no-omagic to undo the effects of the -N option.
 496
 497 * Support for Texas Instruments TMS320C4x and TMS320C3x series of
 498   DSP's contributed by Michael Hayes and Svein E. Seldal.
 499
 500 * Added --with-lib-path configure switch to specify default value for
 501   LIB_PATH.
 502
 503 * ARM port to QNX operating system added by Graeme Peterson.
 504
 505 * IP2K support added by Denis Chertykov.
 506
 507 Changes in 2.13:
 508
 509 * Support for the Fujitsu FRV architecture added by Red Hat. Models for FR400
 510   and FR500 included.
 511
 512 Changes in version 2.13:
 513
 514 * DEC VAX ELF support, by Matt Thomas.
 515
 516 Changes in version 2.12:
 517
 518 * Support for Don Knuth's MMIX, by Hans-Peter Nilsson.
 519
 520 * Support for the OpenRISC 32-bit embedded processor by OpenCores.
 521
 522 * Support for -z nocopyreloc in the x86 ELF linker, which disables
 523   production of copy relocs.  Warning: using this option may result in
 524   non-sharable applications.
 525
 526 * Support for -z combreloc in the ELF linker, which puts dynamic
 527   relocations against the same symbol together, so that dynamic linker
 528   can use an one-entry symbol lookup cache.
 529
 530 * Support for ELF SHF_MERGE section merging, by Jakub Jelinek.
 531
 532 Changes in version 2.11:
 533
 534 * Support for AMD x86-64 architecture, by Jan Hubicka, SuSE Labs.
 535
 536 * Support added for eliminating duplicate DWARF2 debug information by
 537   having the compiler generate the information in sections called
 538   .gnu.linkonce.wi.XXXX where XXXX is a checksum for the contents.  The
 539   linker then merges these sections together into the normal .debug_info
 540   section.
 541
 542 * The native ELF linker now searches the directories in DT_RUNPATH or
 543   DT_RPATH of a shared library for shared libraries needed by it.
 544
 545 * TI C54x support, by Timothy Wall.
 546
 547 * Added command-line switch --section-start to set the start address of any
 548   specified section.
 549
 550 * Added ability to emit full relocation information in linked executables,
 551   enabled by --emit-relocs.  Some post-linkage optimization tools need
 552   this information in order to be able to correctly identify and perform
 553   symbol relative addressing in the event of changes in section contents
 554   (instructions being added or deleted, extending data sections, etc.)
 555
 556 * Support for i860, by Jason Eckhardt (preliminary, alpha quality).
 557
 558 * Support for CRIS (Axis Communications ETRAX series).
 559
 560 * Support for PDP-11 and 2.11BSD a.out format, by Lars Brinkhoff.
 561
 562 Changes in version 2.10:
 563
 564 * Added AT> to the linker script language to allow load-time allocation of
 565   sections into regions.
 566
 567 * Added garbage collection of unused sections, enabled by --gc-sections.
 568   It does require a bit of backend support; currently implemented are
 569   arm-elf, avr-elf, d10v-elf, fr30-elf, i386-elf, m32r-elf, m68k-elf,
 570   mcore-elf, mips-elf, mn10300-elf, ppc-elf, sh-elf, sparc-elf, and v850-elf.
 571   Others will ignore the option.
 572
 573 * Added SORT to the linker script language to permit sorting sections by file
 574   name or section name.
 575
 576 * Added EXTERN to the linker script language as an equivalent to the -u
 577   command-line option.
 578
 579 * Added ASSERT to the linker script language.
 580
 581 * Added EXCLUDE_FILE to the linker script language for further control over
 582   wildcard file names.
 583
 584 * Added -O option to optimize linker output (as of this writing, this only
 585   affects ELF shared library generation).
 586
 587 * The -e option now accepts a number as well as a symbol name.
 588
 589 * Added --no-undefined option to disallow undefined symbols when creating a
 590   shared library.
 591
 592 * The linker now issues a warning, not an error, for an undefined symbol when
 593   using -Bsymbolic; use the new --no-undefined option to get the old
 594   behaviour.
 595
 596 * Added --demangle and --no-demangle options.
 597
 598 Changes in version 2.9:
 599
 600 * Added SQUAD to the linker script language.
 601
 602 * New option --no-warn-mismatch.
 603
 604 * The MEMORY command now parses the attributes to determine where sections that
 605   are not placed in a specific memory region are placed.
 606
 607 Changes in version 2.8:
 608
 609 * Linker scripts may now contain shell wildcard characters for file and section
 610   names.
 611
 612 * The linker now supports symbol versions in ELF.
 613
 614 * The NOCROSSREFS command was added to the linker script language.
 615
 616 * The LOADADDR expression was added to the linker script language.
 617
 618 * MAX and MIN functions were added to the linker script language.
 619
 620 * The OVERLAY construct was added to the linker script language.
 621
 622 * New option --warn-section-align to warn when the address of an output section
 623   changes due to alignment of an input section.
 624
 625 * New options --filter/-F and --auxiliary/-f.
 626
 627 Changes in version 2.7:
 628
 629 * New option --cref to print out a cross reference table.
 630
 631 * New option --wrap SYMBOL.
 632
 633 * New option --no-whole-archive, to turn off the effect of --whole-archive.
 634
 635 * Input sections assigned to the output section /DISCARD/ in the linker script
 636   are not included in the output file.
 637
 638 * The SunOS and ELF linkers now merge stabs debugging information which uses
 639   the N_BINCL and N_EINCL stab types.  This reduces the amount of debugging
 640   information generated.
 641
 642 Changes in version 2.6:
 643
 644 * When an ELF section name is representable as a C identifier (this is not true
 645 of most ELF section names), the linker will automatically define symbols
 646 __start_SECNAME and __stop_SECNAME, where SECNAME is the section name, at the
 647 beginning and the end of the section.  This is used by glibc.
 648
 649   Addendum: Current versions of the linker (at least for version 2.18 onwards
 650 and possibly much earlier as well) place two restrictions on this feature:  The
 651 symbols are only implemented for orphaned sections, not for explicitly placed
 652 sections and they are PROVIDEd rather than being defined.
 653
 654 * When an ELF section named .gnu.warning is encountered in an input file, the
 655 contents of the section are displayed as an error message, and the section is
 656 not copied into the output file.  This is used by glibc.
 657
 658 * When an ELF section named .gnu.warning.SYMBOL is encountered in an input
 659 file, and the symbol SYMBOL is referenced by some object file, the contents of
 660 the section are displayed as an error message.  The section is not copied into
 661 the output file, unless doing a relocatable or shared link.  This is used by
 662 glibc.
 663
 664 * New options -split-by-reloc and -split-by-file.
 665
 666 * The linker now supports linking PIC compiled code on SPARC SunOS.  It can
 667 also create SPARC SunOS shared libraries, and, like the native SunOS linker,
 668 will do so whenever there is an undefined symbol in the link and neither the -e
 669 nor the -r option was used.
 670
 671 * The -rpath option may be used on SunOS to set the list of directories to be
 672 searched at run time.  This overrides the default of building the list from the
 673 -L options.
 674
 675 * The COFF linker now combines debugging information for structs, unions, and
 676 enums, so that even if the same type is defined in multiple input files it will
 677 only be defined once in the output file.  The --traditional-format switch will
 678 prevent this optimization.
 679
 680 Changes in version 2.5:
 681
 682 * The linker now supports linking against SunOS shared libraries.  It still can
 683 not link SunOS PIC (Position Independent Code) files, so it can not be used to
 684 generate shared libraries.
 685
 686 * The linker now supports linking against ELF shared libraries for the i386
 687 (UnixWare) and SPARC (Solaris).  It can also link ELF PIC files, and can be
 688 used to generate shared libraries.  Shared library generation is not well
 689 tested; please report any problems encountered.  The linker is now enabled for
 690 Solaris again.
 691
 692 * Eric Youngdale has contributed Linux support code, including linking against
 693 Linux a.out shared libraries.  The linker produces Linux QMAGIC binaries.
 694
 695 * The ELF backend has been converted to the new linker code.  To use the new
 696 ELF linker, each particular target requires a relocation function.  So far,
 697 this function has been written for i386 (UnixWare), SPARC (Solaris) MIPS (Irix
 698 5), and HPPA ELF targets.
 699
 700 * The -( (--start-group) and -) (--end-group) options have been added to
 701 support searching a group of archives as though they were a single archive.
 702 This can also be used in a linker script, as GROUP ( files ).
 703
 704 * When a file is named on the command line, and the linker does not recognize
 705 it as an object file, the linker will now treat the file as a linker script
 706 file.  A linker script named in this way augments, but does not replace, the
 707 default linker script.
 708
 709 * The -warn-once option was added.  It causes the linker to only warn once per
 710 undefined symbol, rather than once per reference.
 711
 712 * The COFF backend has been converted to the new linker code.  As with ELF, to
 713 use the new linker, each particular target requires a relocation function.  So
 714 far, this function has been written for the i386, m68k, a29k and SH targets.
 715
 716 * The -V flag was made a synonym for -v, for SVR4 compatibility.  The old -V
 717 behaviour is available via --verbose.
 718
 719 Changes in version 2.4:
 720
 721 * New linker code, by Steve Chamberlain and Ian Taylor.  For a.out and ecoff
 722   formats (so far), this should result in considerable savings in time
 723   and memory used while linking; slightly poorer performance than
 724   before for formats not converted yet.
 725
 726 * Command-line parsing is no longer done with flex.  This means
 727   oddball characters in filenames won't get treated as argument
 728   separators.
 729
 730 * HP-PA ELF support, by Jeff Law.  (No SOM support yet.)
 731
 732 * Mach i386 support, by David Mackenzie.
 733
 734 * Irix 4 shared libraries are now supported (Irix 5 uses ELF, and ELF shared
 735   libraries are not yet supported).
 736
 737 * COFF shared libraries (as on SCO) should work as well.
 738
 739 * The linker is disabled for Solaris.  (Actually, it was in 2.3 also, I just
 740   forgot to note it.)  Some of their C library routines don't work when
 741   statically linked, and the GNU linker doesn't support dynamic linking yet.
 742
 743 Changes in version 2.3:
 744
 745 * Weak symbols are now supported.
 746
 747 * ELF support has been added.  The linker has been bootstrapped on
 748   UnixWare and Solaris.
 749
 750 * Alpha OSF/1 support has been added (non dynamic linking only).
 751
 752 Changes in version 2.2:
 753
 754 * The `bfd' library has been updated to reduce a.out-format string
 755   table size.  The effect of this is that files linked from many input
 756   files with duplicate symbols (`-g' debugging records, or identical
 757   static symbols) should be much smaller.
 758
 759 Changes in version 2.1:
 760
 761 * The ld -ySYMBOL flag (to trace references to SYMBOL) is now implemented.
 762
 763 * There is now support for writing ECOFF files, so ld and the
 764   other utilities should work on Risc/Ultrix and Irix.
 765
 766 \f
 767 Copyright (C) 2012-2019 Free Software Foundation, Inc.
 768
 769 Copying and distribution of this file, with or without modification,
 770 are permitted in any medium without royalty provided the copyright
 771 notice and this notice are preserved.
 772
 773 Local variables:
 774 fill-column: 79
 775 End: