ld/NEWS

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