ld/NEWS

   1 -*- text -*-
   2
   3 Changes in 2.31:
   4
   5 * Speed up direct linking with DLLs for Cygwin and Mingw targets.
   6
   7 * Add a configure option --enable-separate-code to decide whether
   8   -z separate-code should be enabled in ELF linker by default.  Default
   9   to yes for Linux/x86 targets.  Note that -z separate-code can increase
  10   disk and memory size.
  11
  12 Changes in 2.30:
  13
  14 * Add -z separate-code to generate separate code PT_LOAD segment.
  15
  16 * Add "-z undefs" command-line option as the inverse of the "-z defs" option.
  17
  18 * Add -z globalaudit command-line option to force audit libraries to be run
  19   for every dynamic object loaded by an executable - provided that the loader
  20   supports this functionality.
  21
  22 * Tighten linker script grammar around file name specifiers to prevent the use
  23   of SORT_BY_ALIGNMENT and SORT_BY_INIT_PRIORITY on filenames.  These would
  24   previously be accepted but had no effect.
  25
  26 * The EXCLUDE_FILE directive can now be placed within any SORT_* directive
  27   within input section lists.
  28
  29 Changes in 2.29:
  30
  31 * Support for -z shstk in the x86 ELF linker to generate
  32   GNU_PROPERTY_X86_FEATURE_1_SHSTK in ELF GNU program properties.
  33
  34 * Add support for GNU_PROPERTY_X86_FEATURE_1_SHSTK in ELF GNU program
  35   properties in the x86 ELF linker.
  36
  37 * Add support for GNU_PROPERTY_X86_FEATURE_1_IBT in ELF GNU program
  38   properties in the x86 ELF linker.
  39
  40 * Support for -z ibtplt in the x86 ELF linker to generate IBT-enabled
  41   PLT.
  42
  43 * Support for -z ibt in the x86 ELF linker to generate IBT-enabled
  44   PLT as well as GNU_PROPERTY_X86_FEATURE_1_IBT in ELF GNU program
  45   properties.
  46
  47 * Add support for ELF SHF_GNU_MBIND and PT_GNU_MBIND_XXX.
  48
  49 * Add support for ELF GNU program properties.
  50
  51 * Add support for the Texas Instruments PRU processor.
  52
  53 * When configuring for arc*-*-linux* targets the default linker emulation will
  54   change if --with-cpu=nps400 is used at configure time.
  55
  56 * Improve assignment of LMAs to orphan sections in some edge cases where a
  57   mixture of both AT>LMA_REGION and AT(LMA) are used.
  58
  59 * Orphan sections placed after an empty section that has an AT(LMA) will now
  60   take an load memory address starting from LMA.
  61
  62 * Section groups can now be resolved (the group deleted and the group members
  63   placed like normal sections) at partial link time either using the new linker
  64   option --force-group-allocation or by placing FORCE_GROUP_ALLOCATION into the
  65   linker script.
  66
  67 Changes in 2.28:
  68
  69 * The EXCLUDE_FILE linker script construct can now be applied outside of the
  70   section list in order for the exclusions to apply over all input sections in
  71   the list.
  72
  73 * Add support for the RISC-V architecture.
  74
  75 * The command-line option --no-eh-frame-hdr can now be used in ELF based
  76   linkers to disable the automatic generation of .eh_frame_hdr sections.
  77
  78 * Add --in-implib=<infile> to the ARM linker to enable specifying a set of
  79   Secure Gateway veneers that must exist in the output import library specified
  80   by --out-implib=<outfile> and the address they must have.  As such,
  81   --in-implib is only supported in combination with --cmse-implib.
  82
  83 * Extended the --out-implib=<file> option, previously restricted to x86 PE
  84   targets, to any ELF based target.  This allows the generation of an import
  85   library for an ELF executable, which can then be used by another application
  86   to link against the executable.
  87
  88 Changes in 2.27:
  89
  90 * Add a configure option --enable-relro to decide whether -z relro should
  91   be enabled in ELF linker by default.  Default to yes for all Linux
  92   targets except FRV, HPPA, IA64 and MIPS.  Note that -z relro can increase
  93   disk and memory size.
  94
  95 * Support for -z noreloc-overflow in the x86-64 ELF linker to disable
  96   relocation overflow check.
  97
  98 * Add -z common/-z nocommon options for ELF targets to control whether to
  99   convert common symbols to the STT_COMMON type during a relocatable link.
 100
 101 * Support for -z nodynamic-undefined-weak in the x86 ELF linker, which
 102   avoids dynamic relocations against undefined weak symbols in executable.
 103
 104 * The NOCROSSREFSTO command was added to the linker script language.
 105
 106 * Add --no-apply-dynamic-relocs to the AArch64 linker to do not apply link-time
 107   values for dynamic relocations.
 108
 109 Changes in 2.26:
 110
 111 * Add --fix-stm32l4xx-629360 to the ARM linker to enable a link-time
 112   workaround for a bug in the bus matrix / memory controller for some of
 113   the STM32 Cortex-M4 based products (STM32L4xx)
 114
 115 * Add a configure option --enable-compressed-debug-sections={all,ld} to
 116   decide whether DWARF debug sections should be compressed by default.
 117
 118 * Add support for the ARC EM/HS, and ARC600/700 architectures.
 119
 120 * Experimental support for linker garbage collection (--gc-sections)
 121   has been enabled for COFF and PE based targets.
 122
 123 * New command-line option for ELF targets to compress DWARF debug
 124   sections, --compress-debug-sections=[none|zlib|zlib-gnu|zlib-gabi].
 125
 126 * New command-line option, --orphan-handling=[place|warn|error|discard], to
 127   adjust how orphan sections are handled.  The default is 'place' which gives
 128   the current behaviour, 'warn' and 'error' issue a warning or error
 129   respectively when orphan sections are found, and 'discard' will discard all
 130   orphan sections.
 131
 132 * Add support for LLVM plugin.
 133
 134 * Add --print-memory-usage option to report memory blocks usage.
 135
 136 * Add --require-defined option, it's like --undefined except the new symbol
 137   must be defined by the end of the link.
 138
 139 Changes in 2.25:
 140
 141 * PE binaries now once again contain real timestamps by default.  To disable
 142   the inclusion of a timestamp in a PE binary, use the --no-insert-timestamp
 143   command-line option.
 144
 145 * Replace support for openrisc and or32 with support for or1k.
 146
 147 * Add support for the --build-id command-line option to COFF based targets.
 148
 149 * x86/x86_64 pe-coff now supports the --build-id option.
 150
 151 * Add support for the Andes NDS32.
 152
 153 Changes in 2.24:
 154
 155 * Add LOG2CEIL() builtin function to the linker script language
 156
 157 * Add support for the Texas Instruments MSP430X processor.
 158
 159 * Add support for Altera Nios II.
 160
 161 * Add support for the V850E3V5 architecture.
 162
 163 * Add support for the Imagination Technologies Meta processor.
 164
 165 * --enable-new-dtags no longer generates old dtags in addition to new dtags.
 166
 167 * Remove linker support for MIPS ECOFF targets.
 168
 169 * Add ALIGN_WITH_INPUT to the linker script language to force the alignment of
 170   an output section to use the maximum alignment of all its input sections.
 171
 172 Changes in 2.23:
 173
 174 * Enable compressed debug section feature for x86/x86_64 pe-coff.
 175
 176 * Add support for the 64-bit ARM architecture: AArch64.
 177
 178 * Added SORT_NONE to the linker script language to disable section sorting.
 179
 180 * Add a linker-provided symbol when producing ELF output, '__ehdr_start'
 181   to point to the ELF file header (and nearby program headers) in the
 182   program's memory image.
 183
 184 * Add support for S12X processor.
 185
 186 * Add support for the VLE extension to the PowerPC architecture.
 187
 188 * Add support for the Freescale XGATE architecture.
 189
 190 * Add option -f FILE on AIX (for response file).
 191
 192 * Add support for the Renesas RL78 architecture.
 193
 194 * Add support for the Adapteva EPIPHANY architecture.
 195
 196 Changes in 2.22:
 197
 198 * --copy-dt-needed-entries is no longer enabled by default.  Instead
 199   --no-copy-dt-needed-entries is the default.
 200
 201 * INPUT_SECTION_FLAGS has been added to the linker script language
 202   to allow selection of input sections by section header section flags.
 203
 204 * Add support for the Tilera TILEPro and TILE-Gx architectures.
 205
 206 * Added SORT_BY_INIT_PRIORITY to the linker script language to permit
 207   sorting sections by numerical value of the GCC init_priority attribute
 208   encoded in the section name.
 209
 210 Changes in 2.21:
 211
 212 * Linker script expression evaluation is somewhat more sane.  This may
 213   break scripts that depend on quirks of the old expression evaluation.
 214
 215 * Turn off underscoring for x86_64 PE+-COFF targets.  For old behavior the
 216   option --enable-leading-mingw64-underscores can be used on configure of
 217   bfd.
 218
 219 * Add support for the TMS320C6000 (TI C6X) processor family.
 220
 221 * --add-needed renamed to --copy-dt-needed-entries in order to avoid confusion
 222   with --as-needed option.
 223
 224 * Extend .def file syntax by '== <ID>' for imports and exports. This allows
 225   to alias the import/export table name written in PE image.
 226
 227 * Add --exclude-all-symbols option to PE based linkers.  This prevents all
 228   symbols from automatically being exported.
 229
 230 * Add support for the Renesas RX processor.
 231
 232 * Add support for alpha-vms target.
 233
 234 Changes in 2.20:
 235
 236 * GNU/Linux targets now support the STB_GNU_UNIQUE symbol binding.  This is a
 237   GNU extension to the standard set of ELF symbol bindings.  The binding will
 238   be passed on to the dynamic linker which will make sure that in the entire
 239   process there is just one symbol with the given name and type in use.
 240
 241 * PE targets now support a GNU extension to allow the alignment of common
 242   common symbols to be specified.  This support uses custom options in
 243   the .drectve section, which will be disregarded by the native tools.
 244
 245 * PE targets now add primitive support for ELF version scripts; symbols
 246   are not versioned, but the local and global symbol visibility directives
 247   are respected when filtering symbols in auto-export mode.
 248
 249 * New option --no-export-dynamic to undo the effect of the -E and
 250   --export-dynamic options.
 251
 252 * ELF: --warn-alternate-em option to warn if an object has alternate
 253   ELF machine code.
 254
 255 * New script function REGION_ALIAS to add alias names to memory regions.
 256
 257 * PE targets no longer make use of the long section names PE extension to
 258   the COFF format when generating executable images, by default.  The old
 259   (slightly non-conformant) behaviour can still be invoked by using the
 260   new '--enable-long-section-names' command-line option.  It is also enabled
 261   automatically in the presence of un-stripped debug information, as GDB
 262   needs to be able to find the debug info sections by their full names.
 263
 264 * For GNU/Linux systems the linker will now avoid processing any relocations
 265   made against symbols of the STT_GNU_IFUNC type and instead emit them into
 266   the resulting binary for processing by the loader.
 267
 268 * --as-needed now links in a dynamic library if it satisfies undefined
 269   symbols in regular objects, or in other dynamic libraries.  In the
 270   latter case the library is not linked if it is found in a DT_NEEDED
 271   entry of one of the libraries already linked.
 272
 273 * Add a new command-line option, -Ttext-segment ADDR, for ELF targets
 274   to set the address of the first byte of the text segment.
 275
 276 * Add support for Sunplus score architecture.
 277
 278 * Add new option --use-nul-prefixed-import-tables to ld for PE targets to
 279   allow fallback to old import table generation with null element prefix.
 280
 281 * Windows PE systems now support a new --exclude-modules-for-implib option,
 282   allowing users to partition object files and archive members between a DLL
 283   and its associated import library as they are generated during linking.
 284
 285 * Add support for Lattice Mico32 (lm32) architecture.
 286
 287 * Add CR16 ELF --embedded-relocs (used to embedded relocations into binaries
 288   for Embedded-PIC code) option.
 289
 290 * Add to the PE/PE+ targets the support of two different kinds of
 291   pseudo-relocations.  They can be selected by the switches
 292   --enable-runtime-pseudo-reloc-v1 and --enable-runtime-pseudo-reloc-v2.
 293   For the switch --enable-runtime-pseudo-reloc it uses for 32-bit
 294   runtime pseudo relocation version one, for 64-bit the version two.
 295
 296 Changes in 2.19:
 297
 298 * Linker scripts support a new INSERT command that makes it easier to
 299   augment the default script.
 300
 301 * Linker script input section filespecs may now specify a file within an
 302   archive by writing "archive:file".
 303
 304 * The --sort-common switch now has an optional argument which specifies the
 305   direction of sorting.
 306
 307 * The M68K linker now supports multiple GOT generation schemes controlled via
 308   the --got=<type> command-line option.
 309
 310 * The ARM EABI linker will now generate stubs for function calls to symbols
 311   that are too far away.  The placement of the stubs is controlled by a new
 312   linker command-line option: --stub-group-size=N.
 313
 314 Changes in 2.18:
 315
 316 * Linker sources now released under version 3 of the GNU General Public
 317   License.
 318
 319 * ELF: New --build-id option to generate a unique per-binary identifier
 320   embedded in a note section.
 321
 322 * Added support for National Semicondutor CompactRISC (ie CR16) target.
 323
 324 * -l:foo now searches the library path for a filename called foo,
 325   without converting it to libfoo.a or libfoo.so.
 326
 327 * Add a new command-line option '--default-script=FILE' or '-dT FILE'
 328   which specifies a replacement for the built in, default linker
 329   script.
 330
 331 * ELF: Add -Bsymbolic-functions, --dynamic-list-cpp-new, which puts C++
 332   operator new and delete on the dynamic list, and --dynamic-list-data,
 333   builtin list for --dynamic-list, which puts global data symbols on the
 334   dynamic list.
 335
 336 * Add support for x86_64 PE+ target.
 337
 338 * Add support for Score target.
 339
 340 * ELF: Add --dynamic-list option to specify a list of global symbols
 341   whose references shouldn't be bound to the definition within the
 342   shared library, or a list of symbols which should be added to the
 343   symbol table in the executable.
 344
 345 * The default output section LMA has changed for allocatable sections from
 346   being equal to VMA, to keeping the difference between LMA and VMA the same as
 347   the previous output section in the same region.  This is a more useful
 348   default when using overlays and other cases where you specify an LMA
 349   differing from the VMA for some sections.
 350
 351 * New switch: --print-gc-sections to list any sections removed by garabge
 352   collection.
 353
 354 * ARM: Added --vfp11-denorm-fix option to work around an erratum in current
 355   VFP11 coprocessors.
 356
 357 Changes in 2.17:
 358
 359 * Support for the Infineon XC16X has been added by KPIT Cummins Infosystems.
 360
 361 * Modify the Linux linker search order to better match ld.so search order.
 362   Look for DT_NEEDED libraries in paths specified by ld.so.conf before
 363   searching the default directories, rather than vice versa.
 364   Use $prefix/etc/ld.so.conf if it exists, otherwise /etc/ld.so.conf.
 365
 366 * PE-COFF: Forward exports from DLL's can now be specified in .def files
 367   passed directly to ld.
 368
 369 * Support for the Z80 processor family has been added.
 370
 371 * Add support for the "@<file>" syntax to the command line, so that extra
 372   switches can be read from <file>.
 373
 374 Changes in 2.16:
 375
 376 * Support for the R_ARM_V4BX relocation as defined in the ARM AAELF
 377   specification has been added via the --fix-v4bx command-line option.
 378
 379 * New linker script construct AS_NEEDED(), which sets the --as-needed flag
 380   for input files listed inside of it.
 381
 382 * A new command-line option, --sysroot, can be used to override the
 383   default sysroot location.  It only applies to toolchains that were
 384   configured using --with-sysroot.
 385
 386 * New linker script functions: ORIGIN() and LENGTH() which return information
 387   about a specified memory region.
 388
 389 * Port to MAXQ processor contributed by HCL Tech.
 390
 391 * Added SEGMENT_START to the linker script language to permit the user to
 392   override the base address for a segment from the command-line.
 393
 394 * ELF: --warn-shared-textrel option to warn if adding a DT_TEXTREL to a shared
 395   object.
 396
 397 * Added SORT_BY_NAME and SORT_BY_ALIGNMENT to the linker script
 398   language to permit sorting sections by section name or section
 399   maximum alignment.
 400
 401 * Added a new linker command-line switch, --sort-section name|alignment,
 402   to sort sections by section name or maximum alignment.
 403
 404 * ELF: --add-needed/--no-add-needed options to control if a DT_NEEDED tag
 405   should be added when a shared library comes from DT_NEEDED tags.
 406
 407 * Support for the crx-elf target added.
 408
 409 * Support for the sh-symbianelf target added.
 410
 411 * A new linker command-line switch has been added which allows the hash table
 412   size to be set to a suitable prime value near to its argument.  This switch
 413   is --hash-size=<NUMBER>.  Also if the switch --reduce-memory-overheads is
 414   used, and --hash-size has not been used, then the default value will be set
 415   to 1021.
 416
 417 * Linker map files are now generated with an O(N) algorithm for finding symbols
 418   that are defined in each section.  This uses about 40% more memory for
 419   symbols than the old O(N^2) algorithm.  You can use the new
 420   --reduce-memory-overheads option to select the old algorithm; this option
 421   might also be used in the future to select similar tradeoffs.
 422
 423 Changes in 2.15:
 424
 425 * ELF: --as-needed/--no-as-needed options to control if a DT_NEEDED tag should
 426   be added only when a shared library is referenced.
 427
 428 * PE: --large-address-aware option to indicate executables support virtual
 429   addresses greater than 2 gigabytes.
 430
 431 * DWARF 2 support for i386pe added.
 432
 433 * The linker script operator DEFINED() will now yield 1 only for a symbol that
 434   is defined before the statement where DEFINED is used.
 435
 436 * The MIPS --embedded-relocs (used to embed relocations into binaries for
 437   Embedded-PIC code) is deprecated and will be removed in a future release.
 438
 439 * cr16c support added by NSC.
 440
 441 * m32r Linux (ELF) support added by Renesas.
 442
 443 * Improved linker's handling of unresolved symbols.  The switch
 444   --unresolved-symbols=<method> has been added to tell the linker when it
 445   should report them and the switch --warn-unresolved-symbols has been added to
 446   make reports be issued as warning messages rather than errors.
 447
 448 Changes in 2.14:
 449
 450 * Added support for Xtensa architecture.
 451
 452 * Added --with-sysroot configure switch to specify a target system root, for
 453   linking against a target filesystem image.
 454
 455 * Added --accept-unknown-linker-format to restore old linker behaviour (pre
 456   2.14) of silently accepting and linking in any files in an unknown binary
 457   file format.
 458
 459 * Added --no-omagic to undo the effects of the -N option.
 460
 461 * Support for Texas Instruments TMS320C4x and TMS320C3x series of
 462   DSP's contributed by Michael Hayes and Svein E. Seldal.
 463
 464 * Added --with-lib-path configure switch to specify default value for
 465   LIB_PATH.
 466
 467 * ARM port to QNX operating system added by Graeme Peterson.
 468
 469 * IP2K support added by Denis Chertykov.
 470
 471 Changes in 2.13:
 472
 473 * Support for the Fujitsu FRV architecture added by Red Hat. Models for FR400
 474   and FR500 included.
 475
 476 Changes in version 2.13:
 477
 478 * DEC VAX ELF support, by Matt Thomas.
 479
 480 Changes in version 2.12:
 481
 482 * Support for Don Knuth's MMIX, by Hans-Peter Nilsson.
 483
 484 * Support for the OpenRISC 32-bit embedded processor by OpenCores.
 485
 486 * Support for -z nocopyreloc in the x86 ELF linker, which disables
 487   production of copy relocs.  Warning: using this option may result in
 488   non-sharable applications.
 489
 490 * Support for -z combreloc in the ELF linker, which puts dynamic
 491   relocations against the same symbol together, so that dynamic linker
 492   can use an one-entry symbol lookup cache.
 493
 494 * Support for ELF SHF_MERGE section merging, by Jakub Jelinek.
 495
 496 Changes in version 2.11:
 497
 498 * Support for AMD x86-64 architecture, by Jan Hubicka, SuSE Labs.
 499
 500 * Support added for eliminating duplicate DWARF2 debug information by
 501   having the compiler generate the information in sections called
 502   .gnu.linkonce.wi.XXXX where XXXX is a checksum for the contents.  The
 503   linker then merges these sections together into the normal .debug_info
 504   section.
 505
 506 * The native ELF linker now searches the directories in DT_RUNPATH or
 507   DT_RPATH of a shared library for shared libraries needed by it.
 508
 509 * TI C54x support, by Timothy Wall.
 510
 511 * Added command-line switch --section-start to set the start address of any
 512   specified section.
 513
 514 * Added ability to emit full relocation information in linked executables,
 515   enabled by --emit-relocs.  Some post-linkage optimization tools need
 516   this information in order to be able to correctly identify and perform
 517   symbol relative addressing in the event of changes in section contents
 518   (instructions being added or deleted, extending data sections, etc.)
 519
 520 * Support for i860, by Jason Eckhardt (preliminary, alpha quality).
 521
 522 * Support for CRIS (Axis Communications ETRAX series).
 523
 524 * Support for PDP-11 and 2.11BSD a.out format, by Lars Brinkhoff.
 525
 526 Changes in version 2.10:
 527
 528 * Added AT> to the linker script language to allow load-time allocation of
 529   sections into regions.
 530
 531 * Added garbage collection of unused sections, enabled by --gc-sections.
 532   It does require a bit of backend support; currently implemented are
 533   arm-elf, avr-elf, d10v-elf, fr30-elf, i386-elf, m32r-elf, m68k-elf,
 534   mcore-elf, mips-elf, mn10300-elf, ppc-elf, sh-elf, sparc-elf, and v850-elf.
 535   Others will ignore the option.
 536
 537 * Added SORT to the linker script language to permit sorting sections by file
 538   name or section name.
 539
 540 * Added EXTERN to the linker script language as an equivalent to the -u
 541   command-line option.
 542
 543 * Added ASSERT to the linker script language.
 544
 545 * Added EXCLUDE_FILE to the linker script language for further control over
 546   wildcard file names.
 547
 548 * Added -O option to optimize linker output (as of this writing, this only
 549   affects ELF shared library generation).
 550
 551 * The -e option now accepts a number as well as a symbol name.
 552
 553 * Added --no-undefined option to disallow undefined symbols when creating a
 554   shared library.
 555
 556 * The linker now issues a warning, not an error, for an undefined symbol when
 557   using -Bsymbolic; use the new --no-undefined option to get the old
 558   behaviour.
 559
 560 * Added --demangle and --no-demangle options.
 561
 562 Changes in version 2.9:
 563
 564 * Added SQUAD to the linker script language.
 565
 566 * New option --no-warn-mismatch.
 567
 568 * The MEMORY command now parses the attributes to determine where sections that
 569   are not placed in a specific memory region are placed.
 570
 571 Changes in version 2.8:
 572
 573 * Linker scripts may now contain shell wildcard characters for file and section
 574   names.
 575
 576 * The linker now supports symbol versions in ELF.
 577
 578 * The NOCROSSREFS command was added to the linker script language.
 579
 580 * The LOADADDR expression was added to the linker script language.
 581
 582 * MAX and MIN functions were added to the linker script language.
 583
 584 * The OVERLAY construct was added to the linker script language.
 585
 586 * New option --warn-section-align to warn when the address of an output section
 587   changes due to alignment of an input section.
 588
 589 * New options --filter/-F and --auxiliary/-f.
 590
 591 Changes in version 2.7:
 592
 593 * New option --cref to print out a cross reference table.
 594
 595 * New option --wrap SYMBOL.
 596
 597 * New option --no-whole-archive, to turn off the effect of --whole-archive.
 598
 599 * Input sections assigned to the output section /DISCARD/ in the linker script
 600   are not included in the output file.
 601
 602 * The SunOS and ELF linkers now merge stabs debugging information which uses
 603   the N_BINCL and N_EINCL stab types.  This reduces the amount of debugging
 604   information generated.
 605
 606 Changes in version 2.6:
 607
 608 * When an ELF section name is representable as a C identifier (this is not true
 609 of most ELF section names), the linker will automatically define symbols
 610 __start_SECNAME and __stop_SECNAME, where SECNAME is the section name, at the
 611 beginning and the end of the section.  This is used by glibc.
 612
 613   Addendum: Current versions of the linker (at least for version 2.18 onwards
 614 and possibly much earlier as well) place two restrictions on this feature:  The
 615 symbols are only implemented for orphaned sections, not for explicitly placed
 616 sections and they are PROVIDEd rather than being defined.
 617
 618 * When an ELF section named .gnu.warning is encountered in an input file, the
 619 contents of the section are displayed as an error message, and the section is
 620 not copied into the output file.  This is used by glibc.
 621
 622 * When an ELF section named .gnu.warning.SYMBOL is encountered in an input
 623 file, and the symbol SYMBOL is referenced by some object file, the contents of
 624 the section are displayed as an error message.  The section is not copied into
 625 the output file, unless doing a relocatable or shared link.  This is used by
 626 glibc.
 627
 628 * New options -split-by-reloc and -split-by-file.
 629
 630 * The linker now supports linking PIC compiled code on SPARC SunOS.  It can
 631 also create SPARC SunOS shared libraries, and, like the native SunOS linker,
 632 will do so whenever there is an undefined symbol in the link and neither the -e
 633 nor the -r option was used.
 634
 635 * The -rpath option may be used on SunOS to set the list of directories to be
 636 searched at run time.  This overrides the default of building the list from the
 637 -L options.
 638
 639 * The COFF linker now combines debugging information for structs, unions, and
 640 enums, so that even if the same type is defined in multiple input files it will
 641 only be defined once in the output file.  The --traditional-format switch will
 642 prevent this optimization.
 643
 644 Changes in version 2.5:
 645
 646 * The linker now supports linking against SunOS shared libraries.  It still can
 647 not link SunOS PIC (Position Independent Code) files, so it can not be used to
 648 generate shared libraries.
 649
 650 * The linker now supports linking against ELF shared libraries for the i386
 651 (UnixWare) and SPARC (Solaris).  It can also link ELF PIC files, and can be
 652 used to generate shared libraries.  Shared library generation is not well
 653 tested; please report any problems encountered.  The linker is now enabled for
 654 Solaris again.
 655
 656 * Eric Youngdale has contributed Linux support code, including linking against
 657 Linux a.out shared libraries.  The linker produces Linux QMAGIC binaries.
 658
 659 * The ELF backend has been converted to the new linker code.  To use the new
 660 ELF linker, each particular target requires a relocation function.  So far,
 661 this function has been written for i386 (UnixWare), SPARC (Solaris) MIPS (Irix
 662 5), and HPPA ELF targets.
 663
 664 * The -( (--start-group) and -) (--end-group) options have been added to
 665 support searching a group of archives as though they were a single archive.
 666 This can also be used in a linker script, as GROUP ( files ).
 667
 668 * When a file is named on the command line, and the linker does not recognize
 669 it as an object file, the linker will now treat the file as a linker script
 670 file.  A linker script named in this way augments, but does not replace, the
 671 default linker script.
 672
 673 * The -warn-once option was added.  It causes the linker to only warn once per
 674 undefined symbol, rather than once per reference.
 675
 676 * The COFF backend has been converted to the new linker code.  As with ELF, to
 677 use the new linker, each particular target requires a relocation function.  So
 678 far, this function has been written for the i386, m68k, a29k and SH targets.
 679
 680 * The -V flag was made a synonym for -v, for SVR4 compatibility.  The old -V
 681 behaviour is available via --verbose.
 682
 683 Changes in version 2.4:
 684
 685 * New linker code, by Steve Chamberlain and Ian Taylor.  For a.out and ecoff
 686   formats (so far), this should result in considerable savings in time
 687   and memory used while linking; slightly poorer performance than
 688   before for formats not converted yet.
 689
 690 * Command-line parsing is no longer done with flex.  This means
 691   oddball characters in filenames won't get treated as argument
 692   separators.
 693
 694 * HP-PA ELF support, by Jeff Law.  (No SOM support yet.)
 695
 696 * Mach i386 support, by David Mackenzie.
 697
 698 * Irix 4 shared libraries are now supported (Irix 5 uses ELF, and ELF shared
 699   libraries are not yet supported).
 700
 701 * COFF shared libraries (as on SCO) should work as well.
 702
 703 * The linker is disabled for Solaris.  (Actually, it was in 2.3 also, I just
 704   forgot to note it.)  Some of their C library routines don't work when
 705   statically linked, and the GNU linker doesn't support dynamic linking yet.
 706
 707 Changes in version 2.3:
 708
 709 * Weak symbols are now supported.
 710
 711 * ELF support has been added.  The linker has been bootstrapped on
 712   UnixWare and Solaris.
 713
 714 * Alpha OSF/1 support has been added (non dynamic linking only).
 715
 716 Changes in version 2.2:
 717
 718 * The `bfd' library has been updated to reduce a.out-format string
 719   table size.  The effect of this is that files linked from many input
 720   files with duplicate symbols (`-g' debugging records, or identical
 721   static symbols) should be much smaller.
 722
 723 Changes in version 2.1:
 724
 725 * The ld -ySYMBOL flag (to trace references to SYMBOL) is now implemented.
 726
 727 * There is now support for writing ECOFF files, so ld and the
 728   other utilities should work on Risc/Ultrix and Irix.
 729
 730 \f
 731 Copyright (C) 2012-2018 Free Software Foundation, Inc.
 732
 733 Copying and distribution of this file, with or without modification,
 734 are permitted in any medium without royalty provided the copyright
 735 notice and this notice are preserved.
 736
 737 Local variables:
 738 fill-column: 79
 739 End: