ld/NEWS

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