ld/NEWS

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