ld/NEWS

   1 -*- text -*-
   2
   3 * Speed up direct linking with DLLs for Cygwin and Mingw targets.
   4
   5 * Add a configure option --enable-separate-code to decide whether
   6   -z separate-code should be enabled in ELF linker by default.  Default
   7   to yes for Linux/x86 targets.  Note that -z separate-code can increase
   8   disk and memory size.
   9
  10 Changes in 2.30:
  11
  12 * Add -z separate-code to generate separate code PT_LOAD segment.
  13
  14 * Add "-z undefs" command line option as the inverse of the "-z defs" option.
  15
  16 * Add -z globalaudit command line option to force audit libraries to be run
  17   for every dynamic object loaded by an executable - provided that the loader
  18   supports this functionality.
  19
  20 * Tighten linker script grammar around file name specifiers to prevent the use
  21   of SORT_BY_ALIGNMENT and SORT_BY_INIT_PRIORITY on filenames.  These would
  22   previously be accepted but had no effect.
  23
  24 * The EXCLUDE_FILE directive can now be placed within any SORT_* directive
  25   within input section lists.
  26
  27 Changes in 2.29:
  28
  29 * Support for -z shstk in the x86 ELF linker to generate
  30   GNU_PROPERTY_X86_FEATURE_1_SHSTK in ELF GNU program properties.
  31
  32 * Add support for GNU_PROPERTY_X86_FEATURE_1_SHSTK in ELF GNU program
  33   properties in the x86 ELF linker.
  34
  35 * Add support for GNU_PROPERTY_X86_FEATURE_1_IBT in ELF GNU program
  36   properties in the x86 ELF linker.
  37
  38 * Support for -z ibtplt in the x86 ELF linker to generate IBT-enabled
  39   PLT.
  40
  41 * Support for -z ibt in the x86 ELF linker to generate IBT-enabled
  42   PLT as well as GNU_PROPERTY_X86_FEATURE_1_IBT in ELF GNU program
  43   properties.
  44
  45 * Add support for ELF SHF_GNU_MBIND and PT_GNU_MBIND_XXX.
  46
  47 * Add support for ELF GNU program properties.
  48
  49 * Add support for the Texas Instruments PRU processor.
  50
  51 * When configuring for arc*-*-linux* targets the default linker emulation will
  52   change if --with-cpu=nps400 is used at configure time.
  53
  54 * Improve assignment of LMAs to orphan sections in some edge cases where a
  55   mixture of both AT>LMA_REGION and AT(LMA) are used.
  56
  57 * Orphan sections placed after an empty section that has an AT(LMA) will now
  58   take an load memory address starting from LMA.
  59
  60 * Section groups can now be resolved (the group deleted and the group members
  61   placed like normal sections) at partial link time either using the new linker
  62   option --force-group-allocation or by placing FORCE_GROUP_ALLOCATION into the
  63   linker script.
  64
  65 Changes in 2.28:
  66
  67 * The EXCLUDE_FILE linker script construct can now be applied outside of the
  68   section list in order for the exclusions to apply over all input sections in
  69   the list.
  70
  71 * Add support for the RISC-V architecture.
  72
  73 * The command line option --no-eh-frame-hdr can now be used in ELF based
  74   linkers to disable the automatic generation of .eh_frame_hdr sections.
  75
  76 * Add --in-implib=<infile> to the ARM linker to enable specifying a set of
  77   Secure Gateway veneers that must exist in the output import library specified
  78   by --out-implib=<outfile> and the address they must have.  As such,
  79   --in-implib is only supported in combination with --cmse-implib.
  80
  81 * Extended the --out-implib=<file> option, previously restricted to x86 PE
  82   targets, to any ELF based target.  This allows the generation of an import
  83   library for an ELF executable, which can then be used by another application
  84   to link against the executable.
  85
  86 Changes in 2.27:
  87
  88 * Add a configure option --enable-relro to decide whether -z relro should
  89   be enabled in ELF linker by default.  Default to yes for all Linux
  90   targets except FRV, HPPA, IA64 and MIPS.  Note that -z relro can increase
  91   disk and memory size.
  92
  93 * Support for -z noreloc-overflow in the x86-64 ELF linker to disable
  94   relocation overflow check.
  95
  96 * Add -z common/-z nocommon options for ELF targets to control whether to
  97   convert common symbols to the STT_COMMON type during a relocatable link.
  98
  99 * Support for -z nodynamic-undefined-weak in the x86 ELF linker, which
 100   avoids dynamic relocations against undefined weak symbols in executable.
 101
 102 * The NOCROSSREFSTO command was added to the linker script language.
 103
 104 * Add --no-apply-dynamic-relocs to the AArch64 linker to do not apply link-time
 105   values for dynamic relocations.
 106
 107 Changes in 2.26:
 108
 109 * Add --fix-stm32l4xx-629360 to the ARM linker to enable a link-time
 110   workaround for a bug in the bus matrix / memory controller for some of
 111   the STM32 Cortex-M4 based products (STM32L4xx)
 112
 113 * Add a configure option --enable-compressed-debug-sections={all,ld} to
 114   decide whether DWARF debug sections should be compressed by default.
 115
 116 * Add support for the ARC EM/HS, and ARC600/700 architectures.
 117
 118 * Experimental support for linker garbage collection (--gc-sections)
 119   has been enabled for COFF and PE based targets.
 120
 121 * New command line option for ELF targets to compress DWARF debug
 122   sections, --compress-debug-sections=[none|zlib|zlib-gnu|zlib-gabi].
 123
 124 * New command line option, --orphan-handling=[place|warn|error|discard], to
 125   adjust how orphan sections are handled.  The default is 'place' which gives
 126   the current behaviour, 'warn' and 'error' issue a warning or error
 127   respectively when orphan sections are found, and 'discard' will discard all
 128   orphan sections.
 129
 130 * Add support for LLVM plugin.
 131
 132 * Add --print-memory-usage option to report memory blocks usage.
 133
 134 * Add --require-defined option, it's like --undefined except the new symbol
 135   must be defined by the end of the link.
 136
 137 Changes in 2.25:
 138
 139 * PE binaries now once again contain real timestamps by default.  To disable
 140   the inclusion of a timestamp in a PE binary, use the --no-insert-timestamp
 141   command line option.
 142
 143 * Replace support for openrisc and or32 with support for or1k.
 144
 145 * Add support for the --build-id command line option to COFF based targets.
 146
 147 * x86/x86_64 pe-coff now supports the --build-id option.
 148
 149 * Add support for the Andes NDS32.
 150
 151 Changes in 2.24:
 152
 153 * Add LOG2CEIL() builtin function to the linker script language
 154
 155 * Add support for the Texas Instruments MSP430X processor.
 156
 157 * Add support for Altera Nios II.
 158
 159 * Add support for the V850E3V5 architecture.
 160
 161 * Add support for the Imagination Technologies Meta processor.
 162
 163 * --enable-new-dtags no longer generates old dtags in addition to new dtags.
 164
 165 * Remove linker support for MIPS ECOFF targets.
 166
 167 * Add ALIGN_WITH_INPUT to the linker script language to force the alignment of
 168   an output section to use the maximum alignment of all its input sections.
 169
 170 Changes in 2.23:
 171
 172 * Enable compressed debug section feature for x86/x86_64 pe-coff.
 173
 174 * Add support for the 64-bit ARM architecture: AArch64.
 175
 176 * Added SORT_NONE to the linker script language to disable section sorting.
 177
 178 * Add a linker-provided symbol when producing ELF output, '__ehdr_start'
 179   to point to the ELF file header (and nearby program headers) in the
 180   program's memory image.
 181
 182 * Add support for S12X processor.
 183
 184 * Add support for the VLE extension to the PowerPC architecture.
 185
 186 * Add support for the Freescale XGATE architecture.
 187
 188 * Add option -f FILE on AIX (for response file).
 189
 190 * Add support for the Renesas RL78 architecture.
 191
 192 * Add support for the Adapteva EPIPHANY architecture.
 193
 194 Changes in 2.22:
 195
 196 * --copy-dt-needed-entries is no longer enabled by default.  Instead
 197   --no-copy-dt-needed-entries is the default.
 198
 199 * INPUT_SECTION_FLAGS has been added to the linker script language
 200   to allow selection of input sections by section header section flags.
 201
 202 * Add support for the Tilera TILEPro and TILE-Gx architectures.
 203
 204 * Added SORT_BY_INIT_PRIORITY to the linker script language to permit
 205   sorting sections by numerical value of the GCC init_priority attribute
 206   encoded in the section name.
 207
 208 Changes in 2.21:
 209
 210 * Linker script expression evaluation is somewhat more sane.  This may
 211   break scripts that depend on quirks of the old expression evaluation.
 212
 213 * Turn off underscoring for x86_64 PE+-COFF targets.  For old behavior the
 214   option --enable-leading-mingw64-underscores can be used on configure of
 215   bfd.
 216
 217 * Add support for the TMS320C6000 (TI C6X) processor family.
 218
 219 * --add-needed renamed to --copy-dt-needed-entries in order to avoid confusion
 220   with --as-needed option.
 221
 222 * Extend .def file syntax by '== <ID>' for imports and exports. This allows
 223   to alias the import/export table name written in PE image.
 224
 225 * Add --exclude-all-symbols option to PE based linkers.  This prevents all
 226   symbols from automatically being exported.
 227
 228 * Add support for the Renesas RX processor.
 229
 230 * Add support for alpha-vms target.
 231
 232 Changes in 2.20:
 233
 234 * GNU/Linux targets now support the STB_GNU_UNIQUE symbol binding.  This is a
 235   GNU extension to the standard set of ELF symbol bindings.  The binding will
 236   be passed on to the dynamic linker which will make sure that in the entire
 237   process there is just one symbol with the given name and type in use.
 238
 239 * PE targets now support a GNU extension to allow the alignment of common
 240   common symbols to be specified.  This support uses custom options in
 241   the .drectve section, which will be disregarded by the native tools.
 242
 243 * PE targets now add primitive support for ELF version scripts; symbols
 244   are not versioned, but the local and global symbol visibility directives
 245   are respected when filtering symbols in auto-export mode.
 246
 247 * New option --no-export-dynamic to undo the effect of the -E and
 248   --export-dynamic options.
 249
 250 * ELF: --warn-alternate-em option to warn if an object has alternate
 251   ELF machine code.
 252
 253 * New script function REGION_ALIAS to add alias names to memory regions.
 254
 255 * PE targets no longer make use of the long section names PE extension to
 256   the COFF format when generating executable images, by default.  The old
 257   (slightly non-conformant) behaviour can still be invoked by using the
 258   new '--enable-long-section-names' command-line option.  It is also enabled
 259   automatically in the presence of un-stripped debug information, as GDB
 260   needs to be able to find the debug info sections by their full names.
 261
 262 * For GNU/Linux systems the linker will now avoid processing any relocations
 263   made against symbols of the STT_GNU_IFUNC type and instead emit them into
 264   the resulting binary for processing by the loader.
 265
 266 * --as-needed now links in a dynamic library if it satisfies undefined
 267   symbols in regular objects, or in other dynamic libraries.  In the
 268   latter case the library is not linked if it is found in a DT_NEEDED
 269   entry of one of the libraries already linked.
 270
 271 * Add a new command line option, -Ttext-segment ADDR, for ELF targets
 272   to set the address of the first byte of the text segment.
 273
 274 * Add support for Sunplus score architecture.
 275
 276 * Add new option --use-nul-prefixed-import-tables to ld for PE targets to
 277   allow fallback to old import table generation with null element prefix.
 278
 279 * Windows PE systems now support a new --exclude-modules-for-implib option,
 280   allowing users to partition object files and archive members between a DLL
 281   and its associated import library as they are generated during linking.
 282
 283 * Add support for Lattice Mico32 (lm32) architecture.
 284
 285 * Add CR16 ELF --embedded-relocs (used to embedded relocations into binaries
 286   for Embedded-PIC code) option.
 287
 288 * Add to the PE/PE+ targets the support of two different kinds of
 289   pseudo-relocations.  They can be selected by the switches
 290   --enable-runtime-pseudo-reloc-v1 and --enable-runtime-pseudo-reloc-v2.
 291   For the switch --enable-runtime-pseudo-reloc it uses for 32-bit
 292   runtime pseudo relocation version one, for 64-bit the version two.
 293
 294 Changes in 2.19:
 295
 296 * Linker scripts support a new INSERT command that makes it easier to
 297   augment the default script.
 298
 299 * Linker script input section filespecs may now specify a file within an
 300   archive by writing "archive:file".
 301
 302 * The --sort-common switch now has an optional argument which specifies the
 303   direction of sorting.
 304
 305 * The M68K linker now supports multiple GOT generation schemes controlled via
 306   the --got=<type> command line option.
 307
 308 * The ARM EABI linker will now generate stubs for function calls to symbols
 309   that are too far away.  The placement of the stubs is controlled by a new
 310   linker command line option: --stub-group-size=N.
 311
 312 Changes in 2.18:
 313
 314 * Linker sources now released under version 3 of the GNU General Public
 315   License.
 316
 317 * ELF: New --build-id option to generate a unique per-binary identifier
 318   embedded in a note section.
 319
 320 * Added support for National Semicondutor CompactRISC (ie CR16) target.
 321
 322 * -l:foo now searches the library path for a filename called foo,
 323   without converting it to libfoo.a or libfoo.so.
 324
 325 * Add a new command line option '--default-script=FILE' or '-dT FILE'
 326   which specifies a replacement for the built in, default linker
 327   script.
 328
 329 * ELF: Add -Bsymbolic-functions, --dynamic-list-cpp-new, which puts C++
 330   operator new and delete on the dynamic list, and --dynamic-list-data,
 331   builtin list for --dynamic-list, which puts global data symbols on the
 332   dynamic list.
 333
 334 * Add support for x86_64 PE+ target.
 335
 336 * Add support for Score target.
 337
 338 * ELF: Add --dynamic-list option to specify a list of global symbols
 339   whose references shouldn't be bound to the definition within the
 340   shared library, or a list of symbols which should be added to the
 341   symbol table in the executable.
 342
 343 * The default output section LMA has changed for allocatable sections from
 344   being equal to VMA, to keeping the difference between LMA and VMA the same as
 345   the previous output section in the same region.  This is a more useful
 346   default when using overlays and other cases where you specify an LMA
 347   differing from the VMA for some sections.
 348
 349 * New switch: --print-gc-sections to list any sections removed by garabge
 350   collection.
 351
 352 * ARM: Added --vfp11-denorm-fix option to work around an erratum in current
 353   VFP11 coprocessors.
 354
 355 Changes in 2.17:
 356
 357 * Support for the Infineon XC16X has been added by KPIT Cummins Infosystems.
 358
 359 * Modify the Linux linker search order to better match ld.so search order.
 360   Look for DT_NEEDED libraries in paths specified by ld.so.conf before
 361   searching the default directories, rather than vice versa.
 362   Use $prefix/etc/ld.so.conf if it exists, otherwise /etc/ld.so.conf.
 363
 364 * PE-COFF: Forward exports from DLL's can now be specified in .def files
 365   passed directly to ld.
 366
 367 * Support for the Z80 processor family has been added.
 368
 369 * Add support for the "@<file>" syntax to the command line, so that extra
 370   switches can be read from <file>.
 371
 372 Changes in 2.16:
 373
 374 * Support for the R_ARM_V4BX relocation as defined in the ARM AAELF
 375   specification has been added via the --fix-v4bx command-line option.
 376
 377 * New linker script construct AS_NEEDED(), which sets the --as-needed flag
 378   for input files listed inside of it.
 379
 380 * A new command-line option, --sysroot, can be used to override the
 381   default sysroot location.  It only applies to toolchains that were
 382   configured using --with-sysroot.
 383
 384 * New linker script functions: ORIGIN() and LENGTH() which return information
 385   about a specified memory region.
 386
 387 * Port to MAXQ processor contributed by HCL Tech.
 388
 389 * Added SEGMENT_START to the linker script language to permit the user to
 390   override the base address for a segment from the command-line.
 391
 392 * ELF: --warn-shared-textrel option to warn if adding a DT_TEXTREL to a shared
 393   object.
 394
 395 * Added SORT_BY_NAME and SORT_BY_ALIGNMENT to the linker script
 396   language to permit sorting sections by section name or section
 397   maximum alignment.
 398
 399 * Added a new linker command line switch, --sort-section name|alignment,
 400   to sort sections by section name or maximum alignment.
 401
 402 * ELF: --add-needed/--no-add-needed options to control if a DT_NEEDED tag
 403   should be added when a shared library comes from DT_NEEDED tags.
 404
 405 * Support for the crx-elf target added.
 406
 407 * Support for the sh-symbianelf target added.
 408
 409 * A new linker command line switch has been added which allows the hash table
 410   size to be set to a suitable prime value near to its argument.  This switch
 411   is --hash-size=<NUMBER>.  Also if the switch --reduce-memory-overheads is
 412   used, and --hash-size has not been used, then the default value will be set
 413   to 1021.
 414
 415 * Linker map files are now generated with an O(N) algorithm for finding symbols
 416   that are defined in each section.  This uses about 40% more memory for
 417   symbols than the old O(N^2) algorithm.  You can use the new
 418   --reduce-memory-overheads option to select the old algorithm; this option
 419   might also be used in the future to select similar tradeoffs.
 420
 421 Changes in 2.15:
 422
 423 * ELF: --as-needed/--no-as-needed options to control if a DT_NEEDED tag should
 424   be added only when a shared library is referenced.
 425
 426 * PE: --large-address-aware option to indicate executables support virtual
 427   addresses greater than 2 gigabytes.
 428
 429 * DWARF 2 support for i386pe added.
 430
 431 * The linker script operator DEFINED() will now yield 1 only for a symbol that
 432   is defined before the statement where DEFINED is used.
 433
 434 * The MIPS --embedded-relocs (used to embed relocations into binaries for
 435   Embedded-PIC code) is deprecated and will be removed in a future release.
 436
 437 * cr16c support added by NSC.
 438
 439 * m32r Linux (ELF) support added by Renesas.
 440
 441 * Improved linker's handling of unresolved symbols.  The switch
 442   --unresolved-symbols=<method> has been added to tell the linker when it
 443   should report them and the switch --warn-unresolved-symbols has been added to
 444   make reports be issued as warning messages rather than errors.
 445
 446 Changes in 2.14:
 447
 448 * Added support for Xtensa architecture.
 449
 450 * Added --with-sysroot configure switch to specify a target system root, for
 451   linking against a target filesystem image.
 452
 453 * Added --accept-unknown-linker-format to restore old linker behaviour (pre
 454   2.14) of silently accepting and linking in any files in an unknown binary
 455   file format.
 456
 457 * Added --no-omagic to undo the effects of the -N option.
 458
 459 * Support for Texas Instruments TMS320C4x and TMS320C3x series of
 460   DSP's contributed by Michael Hayes and Svein E. Seldal.
 461
 462 * Added --with-lib-path configure switch to specify default value for
 463   LIB_PATH.
 464
 465 * ARM port to QNX operating system added by Graeme Peterson.
 466
 467 * IP2K support added by Denis Chertykov.
 468
 469 Changes in 2.13:
 470
 471 * Support for the Fujitsu FRV architecture added by Red Hat. Models for FR400
 472   and FR500 included.
 473
 474 Changes in version 2.13:
 475
 476 * DEC VAX ELF support, by Matt Thomas.
 477
 478 Changes in version 2.12:
 479
 480 * Support for Don Knuth's MMIX, by Hans-Peter Nilsson.
 481
 482 * Support for the OpenRISC 32-bit embedded processor by OpenCores.
 483
 484 * Support for -z nocopyreloc in the x86 ELF linker, which disables
 485   production of copy relocs.  Warning: using this option may result in
 486   non-sharable applications.
 487
 488 * Support for -z combreloc in the ELF linker, which puts dynamic
 489   relocations against the same symbol together, so that dynamic linker
 490   can use an one-entry symbol lookup cache.
 491
 492 * Support for ELF SHF_MERGE section merging, by Jakub Jelinek.
 493
 494 Changes in version 2.11:
 495
 496 * Support for AMD x86-64 architecture, by Jan Hubicka, SuSE Labs.
 497
 498 * Support added for eliminating duplicate DWARF2 debug information by
 499   having the compiler generate the information in sections called
 500   .gnu.linkonce.wi.XXXX where XXXX is a checksum for the contents.  The
 501   linker then merges these sections together into the normal .debug_info
 502   section.
 503
 504 * The native ELF linker now searches the directories in DT_RUNPATH or
 505   DT_RPATH of a shared library for shared libraries needed by it.
 506
 507 * TI C54x support, by Timothy Wall.
 508
 509 * Added command line switch --section-start to set the start address of any
 510   specified section.
 511
 512 * Added ability to emit full relocation information in linked executables,
 513   enabled by --emit-relocs.  Some post-linkage optimization tools need
 514   this information in order to be able to correctly identify and perform
 515   symbol relative addressing in the event of changes in section contents
 516   (instructions being added or deleted, extending data sections, etc.)
 517
 518 * Support for i860, by Jason Eckhardt (preliminary, alpha quality).
 519
 520 * Support for CRIS (Axis Communications ETRAX series).
 521
 522 * Support for PDP-11 and 2.11BSD a.out format, by Lars Brinkhoff.
 523
 524 Changes in version 2.10:
 525
 526 * Added AT> to the linker script language to allow load-time allocation of
 527   sections into regions.
 528
 529 * Added garbage collection of unused sections, enabled by --gc-sections.
 530   It does require a bit of backend support; currently implemented are
 531   arm-elf, avr-elf, d10v-elf, fr30-elf, i386-elf, m32r-elf, m68k-elf,
 532   mcore-elf, mips-elf, mn10300-elf, ppc-elf, sh-elf, sparc-elf, and v850-elf.
 533   Others will ignore the option.
 534
 535 * Added SORT to the linker script language to permit sorting sections by file
 536   name or section name.
 537
 538 * Added EXTERN to the linker script language as an equivalent to the -u
 539   command-line option.
 540
 541 * Added ASSERT to the linker script language.
 542
 543 * Added EXCLUDE_FILE to the linker script language for further control over
 544   wildcard file names.
 545
 546 * Added -O option to optimize linker output (as of this writing, this only
 547   affects ELF shared library generation).
 548
 549 * The -e option now accepts a number as well as a symbol name.
 550
 551 * Added --no-undefined option to disallow undefined symbols when creating a
 552   shared library.
 553
 554 * The linker now issues a warning, not an error, for an undefined symbol when
 555   using -Bsymbolic; use the new --no-undefined option to get the old
 556   behaviour.
 557
 558 * Added --demangle and --no-demangle options.
 559
 560 Changes in version 2.9:
 561
 562 * Added SQUAD to the linker script language.
 563
 564 * New option --no-warn-mismatch.
 565
 566 * The MEMORY command now parses the attributes to determine where sections that
 567   are not placed in a specific memory region are placed.
 568
 569 Changes in version 2.8:
 570
 571 * Linker scripts may now contain shell wildcard characters for file and section
 572   names.
 573
 574 * The linker now supports symbol versions in ELF.
 575
 576 * The NOCROSSREFS command was added to the linker script language.
 577
 578 * The LOADADDR expression was added to the linker script language.
 579
 580 * MAX and MIN functions were added to the linker script language.
 581
 582 * The OVERLAY construct was added to the linker script language.
 583
 584 * New option --warn-section-align to warn when the address of an output section
 585   changes due to alignment of an input section.
 586
 587 * New options --filter/-F and --auxiliary/-f.
 588
 589 Changes in version 2.7:
 590
 591 * New option --cref to print out a cross reference table.
 592
 593 * New option --wrap SYMBOL.
 594
 595 * New option --no-whole-archive, to turn off the effect of --whole-archive.
 596
 597 * Input sections assigned to the output section /DISCARD/ in the linker script
 598   are not included in the output file.
 599
 600 * The SunOS and ELF linkers now merge stabs debugging information which uses
 601   the N_BINCL and N_EINCL stab types.  This reduces the amount of debugging
 602   information generated.
 603
 604 Changes in version 2.6:
 605
 606 * When an ELF section name is representable as a C identifier (this is not true
 607 of most ELF section names), the linker will automatically define symbols
 608 __start_SECNAME and __stop_SECNAME, where SECNAME is the section name, at the
 609 beginning and the end of the section.  This is used by glibc.
 610
 611   Addendum: Current versions of the linker (at least for version 2.18 onwards
 612 and possibly much earlier as well) place two restrictions on this feature:  The
 613 symbols are only implemented for orphaned sections, not for explicitly placed
 614 sections and they are PROVIDEd rather than being defined.
 615
 616 * When an ELF section named .gnu.warning is encountered in an input file, the
 617 contents of the section are displayed as an error message, and the section is
 618 not copied into the output file.  This is used by glibc.
 619
 620 * When an ELF section named .gnu.warning.SYMBOL is encountered in an input
 621 file, and the symbol SYMBOL is referenced by some object file, the contents of
 622 the section are displayed as an error message.  The section is not copied into
 623 the output file, unless doing a relocatable or shared link.  This is used by
 624 glibc.
 625
 626 * New options -split-by-reloc and -split-by-file.
 627
 628 * The linker now supports linking PIC compiled code on SPARC SunOS.  It can
 629 also create SPARC SunOS shared libraries, and, like the native SunOS linker,
 630 will do so whenever there is an undefined symbol in the link and neither the -e
 631 nor the -r option was used.
 632
 633 * The -rpath option may be used on SunOS to set the list of directories to be
 634 searched at run time.  This overrides the default of building the list from the
 635 -L options.
 636
 637 * The COFF linker now combines debugging information for structs, unions, and
 638 enums, so that even if the same type is defined in multiple input files it will
 639 only be defined once in the output file.  The --traditional-format switch will
 640 prevent this optimization.
 641
 642 Changes in version 2.5:
 643
 644 * The linker now supports linking against SunOS shared libraries.  It still can
 645 not link SunOS PIC (Position Independent Code) files, so it can not be used to
 646 generate shared libraries.
 647
 648 * The linker now supports linking against ELF shared libraries for the i386
 649 (UnixWare) and SPARC (Solaris).  It can also link ELF PIC files, and can be
 650 used to generate shared libraries.  Shared library generation is not well
 651 tested; please report any problems encountered.  The linker is now enabled for
 652 Solaris again.
 653
 654 * Eric Youngdale has contributed Linux support code, including linking against
 655 Linux a.out shared libraries.  The linker produces Linux QMAGIC binaries.
 656
 657 * The ELF backend has been converted to the new linker code.  To use the new
 658 ELF linker, each particular target requires a relocation function.  So far,
 659 this function has been written for i386 (UnixWare), SPARC (Solaris) MIPS (Irix
 660 5), and HPPA ELF targets.
 661
 662 * The -( (--start-group) and -) (--end-group) options have been added to
 663 support searching a group of archives as though they were a single archive.
 664 This can also be used in a linker script, as GROUP ( files ).
 665
 666 * When a file is named on the command line, and the linker does not recognize
 667 it as an object file, the linker will now treat the file as a linker script
 668 file.  A linker script named in this way augments, but does not replace, the
 669 default linker script.
 670
 671 * The -warn-once option was added.  It causes the linker to only warn once per
 672 undefined symbol, rather than once per reference.
 673
 674 * The COFF backend has been converted to the new linker code.  As with ELF, to
 675 use the new linker, each particular target requires a relocation function.  So
 676 far, this function has been written for the i386, m68k, a29k and SH targets.
 677
 678 * The -V flag was made a synonym for -v, for SVR4 compatibility.  The old -V
 679 behaviour is available via --verbose.
 680
 681 Changes in version 2.4:
 682
 683 * New linker code, by Steve Chamberlain and Ian Taylor.  For a.out and ecoff
 684   formats (so far), this should result in considerable savings in time
 685   and memory used while linking; slightly poorer performance than
 686   before for formats not converted yet.
 687
 688 * Command-line parsing is no longer done with flex.  This means
 689   oddball characters in filenames won't get treated as argument
 690   separators.
 691
 692 * HP-PA ELF support, by Jeff Law.  (No SOM support yet.)
 693
 694 * Mach i386 support, by David Mackenzie.
 695
 696 * Irix 4 shared libraries are now supported (Irix 5 uses ELF, and ELF shared
 697   libraries are not yet supported).
 698
 699 * COFF shared libraries (as on SCO) should work as well.
 700
 701 * The linker is disabled for Solaris.  (Actually, it was in 2.3 also, I just
 702   forgot to note it.)  Some of their C library routines don't work when
 703   statically linked, and the GNU linker doesn't support dynamic linking yet.
 704
 705 Changes in version 2.3:
 706
 707 * Weak symbols are now supported.
 708
 709 * ELF support has been added.  The linker has been bootstrapped on
 710   UnixWare and Solaris.
 711
 712 * Alpha OSF/1 support has been added (non dynamic linking only).
 713
 714 Changes in version 2.2:
 715
 716 * The `bfd' library has been updated to reduce a.out-format string
 717   table size.  The effect of this is that files linked from many input
 718   files with duplicate symbols (`-g' debugging records, or identical
 719   static symbols) should be much smaller.
 720
 721 Changes in version 2.1:
 722
 723 * The ld -ySYMBOL flag (to trace references to SYMBOL) is now implemented.
 724
 725 * There is now support for writing ECOFF files, so ld and the
 726   other utilities should work on Risc/Ultrix and Irix.
 727
 728 \f
 729 Copyright (C) 2012-2018 Free Software Foundation, Inc.
 730
 731 Copying and distribution of this file, with or without modification,
 732 are permitted in any medium without royalty provided the copyright
 733 notice and this notice are preserved.
 734
 735 Local variables:
 736 fill-column: 79
 737 End: