ld/NEWS

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