ld/NEWS

   1 -*- text -*-
   2
   3 * Add command-line options --enable-non-contiguous-regions and
   4   --enable-non-contiguous-regions-warnings.
   5
   6 Changes in 2.34:
   7
   8 * The ld check for "PHDR segment not covered by LOAD segment" is more
   9   effective, catching cases that were wrongly allowed by previous versions of
  10   ld.  If you see this error it is likely you are linking with a bad linker
  11   script or the binary you are building is not intended to be loaded by a
  12   dynamic loader.  In the latter case --no-dynamic-linker is appropriate.
  13
  14 * cr16c support removed.
  15
  16 * Add support for z80-elf.
  17
  18 * Add support for relocation of each byte or word of multibyte value to Z80
  19   targets.
  20
  21 * Add support for Zilog eZ80 (both ADL and Z80 mode) and Zilog Z180 CPUs.
  22
  23 Changes in 2.33:
  24
  25 * Add command-line option --no-print-map-discarded.
  26
  27 * The Cortex-A53 Erratum 843419 workaround now supports a choice of which
  28   workaround to use.  The option --fix-cortex-a53-843419 now takes an
  29   optional argument --fix-cortex-a53-843419[=full|adr|adrp] which can be
  30   used to force a particular workaround to be used.  See --help for AArch64
  31   for more details.
  32
  33 * Add target handlers for AArch64 for ELF GNU program properties.
  34
  35 * Add support for GNU_PROPERTY_AARCH64_FEATURE_1_BTI in ELF GNU program
  36   properties in the AArch64 ELF linker.
  37
  38 * Add support for GNU_PROPERTY_AARCH64_FEATURE_1_PAC in ELF GNU program
  39   properties in the AArch64 ELF linker.
  40
  41 * Add -z force-bti for AArch64 to enable GNU_PROPERTY_AARCH64_FEATURE_1_BTI
  42   on output while warning about missing GNU_PROPERTY_AARCH64_FEATURE_1_BTI
  43   on inputs and use PLTs protected with BTI.
  44
  45 * Add -z pac-plt for AArch64 to pick PAC enabled PLTs.
  46
  47 Changes in 2.32:
  48
  49 * Report property change in linker map file when merging GNU properties.
  50
  51 * Add support for the C-SKY processor series.
  52
  53 * -t now doesn't report members within archives, unless -t is given twice.
  54   A single -t is now more useful when generating a list of files that should be
  55   packaged for a linker bug report.  For example:
  56     gcc hello.c -save-temps -Wl,-t | xargs realpath | sort | uniq > files
  57     tar cJf test.tar.xz `cat files`
  58
  59 Changes in 2.31:
  60
  61 * Speed up direct linking with DLLs for Cygwin and Mingw targets.
  62
  63 * Add a configure option --enable-separate-code to decide whether
  64   -z separate-code should be enabled in ELF linker by default.  Default
  65   to yes for Linux/x86 targets.  Note that -z separate-code can increase
  66   disk and memory size.
  67
  68 Changes in 2.30:
  69
  70 * Add -z separate-code to generate separate code PT_LOAD segment.
  71
  72 * Add "-z undefs" command-line option as the inverse of the "-z defs" option.
  73
  74 * Add -z globalaudit command-line option to force audit libraries to be run
  75   for every dynamic object loaded by an executable - provided that the loader
  76   supports this functionality.
  77
  78 * Tighten linker script grammar around file name specifiers to prevent the use
  79   of SORT_BY_ALIGNMENT and SORT_BY_INIT_PRIORITY on filenames.  These would
  80   previously be accepted but had no effect.
  81
  82 * The EXCLUDE_FILE directive can now be placed within any SORT_* directive
  83   within input section lists.
  84
  85 Changes in 2.29:
  86
  87 * Support for -z shstk in the x86 ELF linker to generate
  88   GNU_PROPERTY_X86_FEATURE_1_SHSTK in ELF GNU program properties.
  89
  90 * Add support for GNU_PROPERTY_X86_FEATURE_1_SHSTK in ELF GNU program
  91   properties in the x86 ELF linker.
  92
  93 * Add support for GNU_PROPERTY_X86_FEATURE_1_IBT in ELF GNU program
  94   properties in the x86 ELF linker.
  95
  96 * Support for -z ibtplt in the x86 ELF linker to generate IBT-enabled
  97   PLT.
  98
  99 * Support for -z ibt in the x86 ELF linker to generate IBT-enabled
 100   PLT as well as GNU_PROPERTY_X86_FEATURE_1_IBT in ELF GNU program
 101   properties.
 102
 103 * Add support for ELF SHF_GNU_MBIND and PT_GNU_MBIND_XXX.
 104
 105 * Add support for ELF GNU program properties.
 106
 107 * Add support for the Texas Instruments PRU processor.
 108
 109 * When configuring for arc*-*-linux* targets the default linker emulation will
 110   change if --with-cpu=nps400 is used at configure time.
 111
 112 * Improve assignment of LMAs to orphan sections in some edge cases where a
 113   mixture of both AT>LMA_REGION and AT(LMA) are used.
 114
 115 * Orphan sections placed after an empty section that has an AT(LMA) will now
 116   take an load memory address starting from LMA.
 117
 118 * Section groups can now be resolved (the group deleted and the group members
 119   placed like normal sections) at partial link time either using the new linker
 120   option --force-group-allocation or by placing FORCE_GROUP_ALLOCATION into the
 121   linker script.
 122
 123 Changes in 2.28:
 124
 125 * The EXCLUDE_FILE linker script construct can now be applied outside of the
 126   section list in order for the exclusions to apply over all input sections in
 127   the list.
 128
 129 * Add support for the RISC-V architecture.
 130
 131 * The command-line option --no-eh-frame-hdr can now be used in ELF based
 132   linkers to disable the automatic generation of .eh_frame_hdr sections.
 133
 134 * Add --in-implib=<infile> to the ARM linker to enable specifying a set of
 135   Secure Gateway veneers that must exist in the output import library specified
 136   by --out-implib=<outfile> and the address they must have.  As such,
 137   --in-implib is only supported in combination with --cmse-implib.
 138
 139 * Extended the --out-implib=<file> option, previously restricted to x86 PE
 140   targets, to any ELF based target.  This allows the generation of an import
 141   library for an ELF executable, which can then be used by another application
 142   to link against the executable.
 143
 144 Changes in 2.27:
 145
 146 * Add a configure option --enable-relro to decide whether -z relro should
 147   be enabled in ELF linker by default.  Default to yes for all Linux
 148   targets except FRV, HPPA, IA64 and MIPS.  Note that -z relro can increase
 149   disk and memory size.
 150
 151 * Support for -z noreloc-overflow in the x86-64 ELF linker to disable
 152   relocation overflow check.
 153
 154 * Add -z common/-z nocommon options for ELF targets to control whether to
 155   convert common symbols to the STT_COMMON type during a relocatable link.
 156
 157 * Support for -z nodynamic-undefined-weak in the x86 ELF linker, which
 158   avoids dynamic relocations against undefined weak symbols in executable.
 159
 160 * The NOCROSSREFSTO command was added to the linker script language.
 161
 162 * Add --no-apply-dynamic-relocs to the AArch64 linker to do not apply link-time
 163   values for dynamic relocations.
 164
 165 Changes in 2.26:
 166
 167 * Add --fix-stm32l4xx-629360 to the ARM linker to enable a link-time
 168   workaround for a bug in the bus matrix / memory controller for some of
 169   the STM32 Cortex-M4 based products (STM32L4xx)
 170
 171 * Add a configure option --enable-compressed-debug-sections={all,ld} to
 172   decide whether DWARF debug sections should be compressed by default.
 173
 174 * Add support for the ARC EM/HS, and ARC600/700 architectures.
 175
 176 * Experimental support for linker garbage collection (--gc-sections)
 177   has been enabled for COFF and PE based targets.
 178
 179 * New command-line option for ELF targets to compress DWARF debug
 180   sections, --compress-debug-sections=[none|zlib|zlib-gnu|zlib-gabi].
 181
 182 * New command-line option, --orphan-handling=[place|warn|error|discard], to
 183   adjust how orphan sections are handled.  The default is 'place' which gives
 184   the current behaviour, 'warn' and 'error' issue a warning or error
 185   respectively when orphan sections are found, and 'discard' will discard all
 186   orphan sections.
 187
 188 * Add support for LLVM plugin.
 189
 190 * Add --print-memory-usage option to report memory blocks usage.
 191
 192 * Add --require-defined option, it's like --undefined except the new symbol
 193   must be defined by the end of the link.
 194
 195 Changes in 2.25:
 196
 197 * PE binaries now once again contain real timestamps by default.  To disable
 198   the inclusion of a timestamp in a PE binary, use the --no-insert-timestamp
 199   command-line option.
 200
 201 * Replace support for openrisc and or32 with support for or1k.
 202
 203 * Add support for the --build-id command-line option to COFF based targets.
 204
 205 * x86/x86_64 pe-coff now supports the --build-id option.
 206
 207 * Add support for the Andes NDS32.
 208
 209 Changes in 2.24:
 210
 211 * Add LOG2CEIL() builtin function to the linker script language
 212
 213 * Add support for the Texas Instruments MSP430X processor.
 214
 215 * Add support for Altera Nios II.
 216
 217 * Add support for the V850E3V5 architecture.
 218
 219 * Add support for the Imagination Technologies Meta processor.
 220
 221 * --enable-new-dtags no longer generates old dtags in addition to new dtags.
 222
 223 * Remove linker support for MIPS ECOFF targets.
 224
 225 * Add ALIGN_WITH_INPUT to the linker script language to force the alignment of
 226   an output section to use the maximum alignment of all its input sections.
 227
 228 Changes in 2.23:
 229
 230 * Enable compressed debug section feature for x86/x86_64 pe-coff.
 231
 232 * Add support for the 64-bit ARM architecture: AArch64.
 233
 234 * Added SORT_NONE to the linker script language to disable section sorting.
 235
 236 * Add a linker-provided symbol when producing ELF output, '__ehdr_start'
 237   to point to the ELF file header (and nearby program headers) in the
 238   program's memory image.
 239
 240 * Add support for S12X processor.
 241
 242 * Add support for the VLE extension to the PowerPC architecture.
 243
 244 * Add support for the Freescale XGATE architecture.
 245
 246 * Add option -f FILE on AIX (for response file).
 247
 248 * Add support for the Renesas RL78 architecture.
 249
 250 * Add support for the Adapteva EPIPHANY architecture.
 251
 252 Changes in 2.22:
 253
 254 * --copy-dt-needed-entries is no longer enabled by default.  Instead
 255   --no-copy-dt-needed-entries is the default.
 256
 257 * INPUT_SECTION_FLAGS has been added to the linker script language
 258   to allow selection of input sections by section header section flags.
 259
 260 * Add support for the Tilera TILEPro and TILE-Gx architectures.
 261
 262 * Added SORT_BY_INIT_PRIORITY to the linker script language to permit
 263   sorting sections by numerical value of the GCC init_priority attribute
 264   encoded in the section name.
 265
 266 Changes in 2.21:
 267
 268 * Linker script expression evaluation is somewhat more sane.  This may
 269   break scripts that depend on quirks of the old expression evaluation.
 270
 271 * Turn off underscoring for x86_64 PE+-COFF targets.  For old behavior the
 272   option --enable-leading-mingw64-underscores can be used on configure of
 273   bfd.
 274
 275 * Add support for the TMS320C6000 (TI C6X) processor family.
 276
 277 * --add-needed renamed to --copy-dt-needed-entries in order to avoid confusion
 278   with --as-needed option.
 279
 280 * Extend .def file syntax by '== <ID>' for imports and exports. This allows
 281   to alias the import/export table name written in PE image.
 282
 283 * Add --exclude-all-symbols option to PE based linkers.  This prevents all
 284   symbols from automatically being exported.
 285
 286 * Add support for the Renesas RX processor.
 287
 288 * Add support for alpha-vms target.
 289
 290 Changes in 2.20:
 291
 292 * GNU/Linux targets now support the STB_GNU_UNIQUE symbol binding.  This is a
 293   GNU extension to the standard set of ELF symbol bindings.  The binding will
 294   be passed on to the dynamic linker which will make sure that in the entire
 295   process there is just one symbol with the given name and type in use.
 296
 297 * PE targets now support a GNU extension to allow the alignment of common
 298   common symbols to be specified.  This support uses custom options in
 299   the .drectve section, which will be disregarded by the native tools.
 300
 301 * PE targets now add primitive support for ELF version scripts; symbols
 302   are not versioned, but the local and global symbol visibility directives
 303   are respected when filtering symbols in auto-export mode.
 304
 305 * New option --no-export-dynamic to undo the effect of the -E and
 306   --export-dynamic options.
 307
 308 * ELF: --warn-alternate-em option to warn if an object has alternate
 309   ELF machine code.
 310
 311 * New script function REGION_ALIAS to add alias names to memory regions.
 312
 313 * PE targets no longer make use of the long section names PE extension to
 314   the COFF format when generating executable images, by default.  The old
 315   (slightly non-conformant) behaviour can still be invoked by using the
 316   new '--enable-long-section-names' command-line option.  It is also enabled
 317   automatically in the presence of un-stripped debug information, as GDB
 318   needs to be able to find the debug info sections by their full names.
 319
 320 * For GNU/Linux systems the linker will now avoid processing any relocations
 321   made against symbols of the STT_GNU_IFUNC type and instead emit them into
 322   the resulting binary for processing by the loader.
 323
 324 * --as-needed now links in a dynamic library if it satisfies undefined
 325   symbols in regular objects, or in other dynamic libraries.  In the
 326   latter case the library is not linked if it is found in a DT_NEEDED
 327   entry of one of the libraries already linked.
 328
 329 * Add a new command-line option, -Ttext-segment ADDR, for ELF targets
 330   to set the address of the first byte of the text segment.
 331
 332 * Add support for Sunplus score architecture.
 333
 334 * Add new option --use-nul-prefixed-import-tables to ld for PE targets to
 335   allow fallback to old import table generation with null element prefix.
 336
 337 * Windows PE systems now support a new --exclude-modules-for-implib option,
 338   allowing users to partition object files and archive members between a DLL
 339   and its associated import library as they are generated during linking.
 340
 341 * Add support for Lattice Mico32 (lm32) architecture.
 342
 343 * Add CR16 ELF --embedded-relocs (used to embedded relocations into binaries
 344   for Embedded-PIC code) option.
 345
 346 * Add to the PE/PE+ targets the support of two different kinds of
 347   pseudo-relocations.  They can be selected by the switches
 348   --enable-runtime-pseudo-reloc-v1 and --enable-runtime-pseudo-reloc-v2.
 349   For the switch --enable-runtime-pseudo-reloc it uses for 32-bit
 350   runtime pseudo relocation version one, for 64-bit the version two.
 351
 352 Changes in 2.19:
 353
 354 * Linker scripts support a new INSERT command that makes it easier to
 355   augment the default script.
 356
 357 * Linker script input section filespecs may now specify a file within an
 358   archive by writing "archive:file".
 359
 360 * The --sort-common switch now has an optional argument which specifies the
 361   direction of sorting.
 362
 363 * The M68K linker now supports multiple GOT generation schemes controlled via
 364   the --got=<type> command-line option.
 365
 366 * The ARM EABI linker will now generate stubs for function calls to symbols
 367   that are too far away.  The placement of the stubs is controlled by a new
 368   linker command-line option: --stub-group-size=N.
 369
 370 Changes in 2.18:
 371
 372 * Linker sources now released under version 3 of the GNU General Public
 373   License.
 374
 375 * ELF: New --build-id option to generate a unique per-binary identifier
 376   embedded in a note section.
 377
 378 * Added support for National Semicondutor CompactRISC (ie CR16) target.
 379
 380 * -l:foo now searches the library path for a filename called foo,
 381   without converting it to libfoo.a or libfoo.so.
 382
 383 * Add a new command-line option '--default-script=FILE' or '-dT FILE'
 384   which specifies a replacement for the built in, default linker
 385   script.
 386
 387 * ELF: Add -Bsymbolic-functions, --dynamic-list-cpp-new, which puts C++
 388   operator new and delete on the dynamic list, and --dynamic-list-data,
 389   builtin list for --dynamic-list, which puts global data symbols on the
 390   dynamic list.
 391
 392 * Add support for x86_64 PE+ target.
 393
 394 * Add support for Score target.
 395
 396 * ELF: Add --dynamic-list option to specify a list of global symbols
 397   whose references shouldn't be bound to the definition within the
 398   shared library, or a list of symbols which should be added to the
 399   symbol table in the executable.
 400
 401 * The default output section LMA has changed for allocatable sections from
 402   being equal to VMA, to keeping the difference between LMA and VMA the same as
 403   the previous output section in the same region.  This is a more useful
 404   default when using overlays and other cases where you specify an LMA
 405   differing from the VMA for some sections.
 406
 407 * New switch: --print-gc-sections to list any sections removed by garabge
 408   collection.
 409
 410 * ARM: Added --vfp11-denorm-fix option to work around an erratum in current
 411   VFP11 coprocessors.
 412
 413 Changes in 2.17:
 414
 415 * Support for the Infineon XC16X has been added by KPIT Cummins Infosystems.
 416
 417 * Modify the Linux linker search order to better match ld.so search order.
 418   Look for DT_NEEDED libraries in paths specified by ld.so.conf before
 419   searching the default directories, rather than vice versa.
 420   Use $prefix/etc/ld.so.conf if it exists, otherwise /etc/ld.so.conf.
 421
 422 * PE-COFF: Forward exports from DLL's can now be specified in .def files
 423   passed directly to ld.
 424
 425 * Support for the Z80 processor family has been added.
 426
 427 * Add support for the "@<file>" syntax to the command line, so that extra
 428   switches can be read from <file>.
 429
 430 Changes in 2.16:
 431
 432 * Support for the R_ARM_V4BX relocation as defined in the ARM AAELF
 433   specification has been added via the --fix-v4bx command-line option.
 434
 435 * New linker script construct AS_NEEDED(), which sets the --as-needed flag
 436   for input files listed inside of it.
 437
 438 * A new command-line option, --sysroot, can be used to override the
 439   default sysroot location.  It only applies to toolchains that were
 440   configured using --with-sysroot.
 441
 442 * New linker script functions: ORIGIN() and LENGTH() which return information
 443   about a specified memory region.
 444
 445 * Port to MAXQ processor contributed by HCL Tech.
 446
 447 * Added SEGMENT_START to the linker script language to permit the user to
 448   override the base address for a segment from the command-line.
 449
 450 * ELF: --warn-shared-textrel option to warn if adding a DT_TEXTREL to a shared
 451   object.
 452
 453 * Added SORT_BY_NAME and SORT_BY_ALIGNMENT to the linker script
 454   language to permit sorting sections by section name or section
 455   maximum alignment.
 456
 457 * Added a new linker command-line switch, --sort-section name|alignment,
 458   to sort sections by section name or maximum alignment.
 459
 460 * ELF: --add-needed/--no-add-needed options to control if a DT_NEEDED tag
 461   should be added when a shared library comes from DT_NEEDED tags.
 462
 463 * Support for the crx-elf target added.
 464
 465 * Support for the sh-symbianelf target added.
 466
 467 * A new linker command-line switch has been added which allows the hash table
 468   size to be set to a suitable prime value near to its argument.  This switch
 469   is --hash-size=<NUMBER>.  Also if the switch --reduce-memory-overheads is
 470   used, and --hash-size has not been used, then the default value will be set
 471   to 1021.
 472
 473 * Linker map files are now generated with an O(N) algorithm for finding symbols
 474   that are defined in each section.  This uses about 40% more memory for
 475   symbols than the old O(N^2) algorithm.  You can use the new
 476   --reduce-memory-overheads option to select the old algorithm; this option
 477   might also be used in the future to select similar tradeoffs.
 478
 479 Changes in 2.15:
 480
 481 * ELF: --as-needed/--no-as-needed options to control if a DT_NEEDED tag should
 482   be added only when a shared library is referenced.
 483
 484 * PE: --large-address-aware option to indicate executables support virtual
 485   addresses greater than 2 gigabytes.
 486
 487 * DWARF 2 support for i386pe added.
 488
 489 * The linker script operator DEFINED() will now yield 1 only for a symbol that
 490   is defined before the statement where DEFINED is used.
 491
 492 * The MIPS --embedded-relocs (used to embed relocations into binaries for
 493   Embedded-PIC code) is deprecated and will be removed in a future release.
 494
 495 * cr16c support added by NSC.
 496
 497 * m32r Linux (ELF) support added by Renesas.
 498
 499 * Improved linker's handling of unresolved symbols.  The switch
 500   --unresolved-symbols=<method> has been added to tell the linker when it
 501   should report them and the switch --warn-unresolved-symbols has been added to
 502   make reports be issued as warning messages rather than errors.
 503
 504 Changes in 2.14:
 505
 506 * Added support for Xtensa architecture.
 507
 508 * Added --with-sysroot configure switch to specify a target system root, for
 509   linking against a target filesystem image.
 510
 511 * Added --accept-unknown-linker-format to restore old linker behaviour (pre
 512   2.14) of silently accepting and linking in any files in an unknown binary
 513   file format.
 514
 515 * Added --no-omagic to undo the effects of the -N option.
 516
 517 * Support for Texas Instruments TMS320C4x and TMS320C3x series of
 518   DSP's contributed by Michael Hayes and Svein E. Seldal.
 519
 520 * Added --with-lib-path configure switch to specify default value for
 521   LIB_PATH.
 522
 523 * ARM port to QNX operating system added by Graeme Peterson.
 524
 525 * IP2K support added by Denis Chertykov.
 526
 527 Changes in 2.13:
 528
 529 * Support for the Fujitsu FRV architecture added by Red Hat. Models for FR400
 530   and FR500 included.
 531
 532 Changes in version 2.13:
 533
 534 * DEC VAX ELF support, by Matt Thomas.
 535
 536 Changes in version 2.12:
 537
 538 * Support for Don Knuth's MMIX, by Hans-Peter Nilsson.
 539
 540 * Support for the OpenRISC 32-bit embedded processor by OpenCores.
 541
 542 * Support for -z nocopyreloc in the x86 ELF linker, which disables
 543   production of copy relocs.  Warning: using this option may result in
 544   non-sharable applications.
 545
 546 * Support for -z combreloc in the ELF linker, which puts dynamic
 547   relocations against the same symbol together, so that dynamic linker
 548   can use an one-entry symbol lookup cache.
 549
 550 * Support for ELF SHF_MERGE section merging, by Jakub Jelinek.
 551
 552 Changes in version 2.11:
 553
 554 * Support for AMD x86-64 architecture, by Jan Hubicka, SuSE Labs.
 555
 556 * Support added for eliminating duplicate DWARF2 debug information by
 557   having the compiler generate the information in sections called
 558   .gnu.linkonce.wi.XXXX where XXXX is a checksum for the contents.  The
 559   linker then merges these sections together into the normal .debug_info
 560   section.
 561
 562 * The native ELF linker now searches the directories in DT_RUNPATH or
 563   DT_RPATH of a shared library for shared libraries needed by it.
 564
 565 * TI C54x support, by Timothy Wall.
 566
 567 * Added command-line switch --section-start to set the start address of any
 568   specified section.
 569
 570 * Added ability to emit full relocation information in linked executables,
 571   enabled by --emit-relocs.  Some post-linkage optimization tools need
 572   this information in order to be able to correctly identify and perform
 573   symbol relative addressing in the event of changes in section contents
 574   (instructions being added or deleted, extending data sections, etc.)
 575
 576 * Support for i860, by Jason Eckhardt (preliminary, alpha quality).
 577
 578 * Support for CRIS (Axis Communications ETRAX series).
 579
 580 * Support for PDP-11 and 2.11BSD a.out format, by Lars Brinkhoff.
 581
 582 Changes in version 2.10:
 583
 584 * Added AT> to the linker script language to allow load-time allocation of
 585   sections into regions.
 586
 587 * Added garbage collection of unused sections, enabled by --gc-sections.
 588   It does require a bit of backend support; currently implemented are
 589   arm-elf, avr-elf, d10v-elf, fr30-elf, i386-elf, m32r-elf, m68k-elf,
 590   mcore-elf, mips-elf, mn10300-elf, ppc-elf, sh-elf, sparc-elf, and v850-elf.
 591   Others will ignore the option.
 592
 593 * Added SORT to the linker script language to permit sorting sections by file
 594   name or section name.
 595
 596 * Added EXTERN to the linker script language as an equivalent to the -u
 597   command-line option.
 598
 599 * Added ASSERT to the linker script language.
 600
 601 * Added EXCLUDE_FILE to the linker script language for further control over
 602   wildcard file names.
 603
 604 * Added -O option to optimize linker output (as of this writing, this only
 605   affects ELF shared library generation).
 606
 607 * The -e option now accepts a number as well as a symbol name.
 608
 609 * Added --no-undefined option to disallow undefined symbols when creating a
 610   shared library.
 611
 612 * The linker now issues a warning, not an error, for an undefined symbol when
 613   using -Bsymbolic; use the new --no-undefined option to get the old
 614   behaviour.
 615
 616 * Added --demangle and --no-demangle options.
 617
 618 Changes in version 2.9:
 619
 620 * Added SQUAD to the linker script language.
 621
 622 * New option --no-warn-mismatch.
 623
 624 * The MEMORY command now parses the attributes to determine where sections that
 625   are not placed in a specific memory region are placed.
 626
 627 Changes in version 2.8:
 628
 629 * Linker scripts may now contain shell wildcard characters for file and section
 630   names.
 631
 632 * The linker now supports symbol versions in ELF.
 633
 634 * The NOCROSSREFS command was added to the linker script language.
 635
 636 * The LOADADDR expression was added to the linker script language.
 637
 638 * MAX and MIN functions were added to the linker script language.
 639
 640 * The OVERLAY construct was added to the linker script language.
 641
 642 * New option --warn-section-align to warn when the address of an output section
 643   changes due to alignment of an input section.
 644
 645 * New options --filter/-F and --auxiliary/-f.
 646
 647 Changes in version 2.7:
 648
 649 * New option --cref to print out a cross reference table.
 650
 651 * New option --wrap SYMBOL.
 652
 653 * New option --no-whole-archive, to turn off the effect of --whole-archive.
 654
 655 * Input sections assigned to the output section /DISCARD/ in the linker script
 656   are not included in the output file.
 657
 658 * The SunOS and ELF linkers now merge stabs debugging information which uses
 659   the N_BINCL and N_EINCL stab types.  This reduces the amount of debugging
 660   information generated.
 661
 662 Changes in version 2.6:
 663
 664 * When an ELF section name is representable as a C identifier (this is not true
 665 of most ELF section names), the linker will automatically define symbols
 666 __start_SECNAME and __stop_SECNAME, where SECNAME is the section name, at the
 667 beginning and the end of the section.  This is used by glibc.
 668
 669   Addendum: Current versions of the linker (at least for version 2.18 onwards
 670 and possibly much earlier as well) place two restrictions on this feature:  The
 671 symbols are only implemented for orphaned sections, not for explicitly placed
 672 sections and they are PROVIDEd rather than being defined.
 673
 674 * When an ELF section named .gnu.warning is encountered in an input file, the
 675 contents of the section are displayed as an error message, and the section is
 676 not copied into the output file.  This is used by glibc.
 677
 678 * When an ELF section named .gnu.warning.SYMBOL is encountered in an input
 679 file, and the symbol SYMBOL is referenced by some object file, the contents of
 680 the section are displayed as an error message.  The section is not copied into
 681 the output file, unless doing a relocatable or shared link.  This is used by
 682 glibc.
 683
 684 * New options -split-by-reloc and -split-by-file.
 685
 686 * The linker now supports linking PIC compiled code on SPARC SunOS.  It can
 687 also create SPARC SunOS shared libraries, and, like the native SunOS linker,
 688 will do so whenever there is an undefined symbol in the link and neither the -e
 689 nor the -r option was used.
 690
 691 * The -rpath option may be used on SunOS to set the list of directories to be
 692 searched at run time.  This overrides the default of building the list from the
 693 -L options.
 694
 695 * The COFF linker now combines debugging information for structs, unions, and
 696 enums, so that even if the same type is defined in multiple input files it will
 697 only be defined once in the output file.  The --traditional-format switch will
 698 prevent this optimization.
 699
 700 Changes in version 2.5:
 701
 702 * The linker now supports linking against SunOS shared libraries.  It still can
 703 not link SunOS PIC (Position Independent Code) files, so it can not be used to
 704 generate shared libraries.
 705
 706 * The linker now supports linking against ELF shared libraries for the i386
 707 (UnixWare) and SPARC (Solaris).  It can also link ELF PIC files, and can be
 708 used to generate shared libraries.  Shared library generation is not well
 709 tested; please report any problems encountered.  The linker is now enabled for
 710 Solaris again.
 711
 712 * Eric Youngdale has contributed Linux support code, including linking against
 713 Linux a.out shared libraries.  The linker produces Linux QMAGIC binaries.
 714
 715 * The ELF backend has been converted to the new linker code.  To use the new
 716 ELF linker, each particular target requires a relocation function.  So far,
 717 this function has been written for i386 (UnixWare), SPARC (Solaris) MIPS (Irix
 718 5), and HPPA ELF targets.
 719
 720 * The -( (--start-group) and -) (--end-group) options have been added to
 721 support searching a group of archives as though they were a single archive.
 722 This can also be used in a linker script, as GROUP ( files ).
 723
 724 * When a file is named on the command line, and the linker does not recognize
 725 it as an object file, the linker will now treat the file as a linker script
 726 file.  A linker script named in this way augments, but does not replace, the
 727 default linker script.
 728
 729 * The -warn-once option was added.  It causes the linker to only warn once per
 730 undefined symbol, rather than once per reference.
 731
 732 * The COFF backend has been converted to the new linker code.  As with ELF, to
 733 use the new linker, each particular target requires a relocation function.  So
 734 far, this function has been written for the i386, m68k, a29k and SH targets.
 735
 736 * The -V flag was made a synonym for -v, for SVR4 compatibility.  The old -V
 737 behaviour is available via --verbose.
 738
 739 Changes in version 2.4:
 740
 741 * New linker code, by Steve Chamberlain and Ian Taylor.  For a.out and ecoff
 742   formats (so far), this should result in considerable savings in time
 743   and memory used while linking; slightly poorer performance than
 744   before for formats not converted yet.
 745
 746 * Command-line parsing is no longer done with flex.  This means
 747   oddball characters in filenames won't get treated as argument
 748   separators.
 749
 750 * HP-PA ELF support, by Jeff Law.  (No SOM support yet.)
 751
 752 * Mach i386 support, by David Mackenzie.
 753
 754 * Irix 4 shared libraries are now supported (Irix 5 uses ELF, and ELF shared
 755   libraries are not yet supported).
 756
 757 * COFF shared libraries (as on SCO) should work as well.
 758
 759 * The linker is disabled for Solaris.  (Actually, it was in 2.3 also, I just
 760   forgot to note it.)  Some of their C library routines don't work when
 761   statically linked, and the GNU linker doesn't support dynamic linking yet.
 762
 763 Changes in version 2.3:
 764
 765 * Weak symbols are now supported.
 766
 767 * ELF support has been added.  The linker has been bootstrapped on
 768   UnixWare and Solaris.
 769
 770 * Alpha OSF/1 support has been added (non dynamic linking only).
 771
 772 Changes in version 2.2:
 773
 774 * The `bfd' library has been updated to reduce a.out-format string
 775   table size.  The effect of this is that files linked from many input
 776   files with duplicate symbols (`-g' debugging records, or identical
 777   static symbols) should be much smaller.
 778
 779 Changes in version 2.1:
 780
 781 * The ld -ySYMBOL flag (to trace references to SYMBOL) is now implemented.
 782
 783 * There is now support for writing ECOFF files, so ld and the
 784   other utilities should work on Risc/Ultrix and Irix.
 785
 786 \f
 787 Copyright (C) 2012-2020 Free Software Foundation, Inc.
 788
 789 Copying and distribution of this file, with or without modification,
 790 are permitted in any medium without royalty provided the copyright
 791 notice and this notice are preserved.
 792
 793 Local variables:
 794 fill-column: 79
 795 End: