ld/NEWS

   1 -*- text -*-
   2
   3 * arm-symbianelf support removed.
   4
   5 * Add -z report-relative-reloc to x86 ELF linker to report dynamic
   6   relative relocations.
   7
   8 * Add -z start-stop-gc to disable special treatment of __start_*/__stop_*
   9   references when --gc-sections.
  10
  11 Changes in 2.36:
  12
  13 * Add libdep plugin, for linking dependencies of static libraries that
  14   were recorded by ar in the __.LIBDEP archive member.
  15
  16 * Add --error-handling-script=<NAME> command line option to allow a helper
  17   script to be invoked when an undefined symbol or a missing library is
  18   encountered.  This option can be suppressed via the configure time
  19   switch: --enable-error-handling-script=no.
  20
  21 * Add -z lam-u48 to x86-64 ELF linker to generate LAM_U48 property.
  22
  23 * Add -z lam-u57 to x86-64 ELF linker to enerate LAM_U57 property.
  24
  25 * Add -z lam-u48-report=[none|warning|error] to report missing LAM_U48
  26   property.
  27
  28 * Add -z lam-u57-report=[none|warning|error] to report missing LAM_U57
  29   property.
  30
  31 * Add -z lam-report=[none|warning|error] to report missing LAM_U48 and
  32   LAM_U57 properties.
  33
  34 * Add -z x86-64-{baseline|v[234]} to the x86 ELF linker to mark
  35   x86-64-{baseline|v[234]} ISA level as needed.
  36
  37 * Add -z unique-symbol to avoid duplicated local symbol names.
  38
  39 * The creation of PE format DLLs now defaults to using a more secure set of DLL
  40   characteristics.
  41
  42 * The linker now deduplicates the types in .ctf sections.  The new
  43   command-line option --ctf-share-types describes how to do this:
  44   its default value, share-unconflicted, produces the most compact
  45   output.
  46
  47 * The linker now omits the "variable section" from .ctf sections by
  48   default, saving space.  This is almost certainly what you want
  49   unless you are working on a project that has its own analogue
  50   of symbol tables that are not reflected in the ELF symtabs.
  51
  52 * Add support for the SHF_GNU_RETAIN ELF section flag.
  53   This flag specifies that the section should not be garbage collected by the
  54   linker.
  55
  56 Changes in 2.35:
  57
  58 * X86 NaCl target support is removed.
  59
  60 * Add ELF linker command-line options, --export-dynamic-symbol and
  61   --export-dynamic-symbol-list, to make symbols dynamic.
  62
  63 * Add a configure option, --enable-textrel-check=[no|yes|warning|error],
  64   to decide what ELF linker should do by default with DT_TEXTREL in an
  65   executable or shared library.  Default to yes for Linux/x86 targets.
  66
  67 * The -Map=<filename> command line option has been extended so that if
  68   <filename> is a directory then <filename>/<output-filename>.map will be
  69   created.
  70
  71 * Add a command-line option for ELF linker, --warn-textrel, to warn that
  72   DT_TEXTREL is set in a position-independent executable or shared object.
  73
  74 * Add command-line options --enable-non-contiguous-regions and
  75   --enable-non-contiguous-regions-warnings.
  76
  77 * Add command-line option --imagic for the pdp11-aout target to output format
  78   IMAGIC (0411) for separate instruction and data spaces, and change the
  79   default format option for pdp11-aout to be --omagic.
  80
  81 * Relative pathnames in INPUT() and GROUP() directives in linker scripts are
  82   searched relative to the directory of the linker script before other search
  83   paths.
  84
  85 * Add ELF linker command-line option `-z start-stop-visibility=...' to control
  86   the visibility of synthetic `__start_SECNAME` and `__stop_SECNAME` symbols.
  87
  88 * Add command-line option --dependency-file to write a Make-style dependency
  89   file listing the input files consulted by the linker, like the files written
  90   by the compiler's -M -MP options.
  91
  92 Changes in 2.34:
  93
  94 * The ld check for "PHDR segment not covered by LOAD segment" is more
  95   effective, catching cases that were wrongly allowed by previous versions of
  96   ld.  If you see this error it is likely you are linking with a bad linker
  97   script or the binary you are building is not intended to be loaded by a
  98   dynamic loader.  In the latter case --no-dynamic-linker is appropriate.
  99
 100 * cr16c support removed.
 101
 102 * Add support for z80-elf.
 103
 104 * Add support for relocation of each byte or word of multibyte value to Z80
 105   targets.
 106
 107 * Add support for Zilog eZ80 (both ADL and Z80 mode) and Zilog Z180 CPUs.
 108
 109 Changes in 2.33:
 110
 111 * Add command-line option --no-print-map-discarded.
 112
 113 * The Cortex-A53 Erratum 843419 workaround now supports a choice of which
 114   workaround to use.  The option --fix-cortex-a53-843419 now takes an
 115   optional argument --fix-cortex-a53-843419[=full|adr|adrp] which can be
 116   used to force a particular workaround to be used.  See --help for AArch64
 117   for more details.
 118
 119 * Add target handlers for AArch64 for ELF GNU program properties.
 120
 121 * Add support for GNU_PROPERTY_AARCH64_FEATURE_1_BTI in ELF GNU program
 122   properties in the AArch64 ELF linker.
 123
 124 * Add support for GNU_PROPERTY_AARCH64_FEATURE_1_PAC in ELF GNU program
 125   properties in the AArch64 ELF linker.
 126
 127 * Add -z force-bti for AArch64 to enable GNU_PROPERTY_AARCH64_FEATURE_1_BTI
 128   on output while warning about missing GNU_PROPERTY_AARCH64_FEATURE_1_BTI
 129   on inputs and use PLTs protected with BTI.
 130
 131 * Add -z pac-plt for AArch64 to pick PAC enabled PLTs.
 132
 133 Changes in 2.32:
 134
 135 * Report property change in linker map file when merging GNU properties.
 136
 137 * Add support for the C-SKY processor series.
 138
 139 * -t now doesn't report members within archives, unless -t is given twice.
 140   A single -t is now more useful when generating a list of files that should be
 141   packaged for a linker bug report.  For example:
 142     gcc hello.c -save-temps -Wl,-t | xargs realpath | sort | uniq > files
 143     tar cJf test.tar.xz `cat files`
 144
 145 Changes in 2.31:
 146
 147 * Speed up direct linking with DLLs for Cygwin and Mingw targets.
 148
 149 * Add a configure option --enable-separate-code to decide whether
 150   -z separate-code should be enabled in ELF linker by default.  Default
 151   to yes for Linux/x86 targets.  Note that -z separate-code can increase
 152   disk and memory size.
 153
 154 Changes in 2.30:
 155
 156 * Add -z separate-code to generate separate code PT_LOAD segment.
 157
 158 * Add "-z undefs" command-line option as the inverse of the "-z defs" option.
 159
 160 * Add -z globalaudit command-line option to force audit libraries to be run
 161   for every dynamic object loaded by an executable - provided that the loader
 162   supports this functionality.
 163
 164 * Tighten linker script grammar around file name specifiers to prevent the use
 165   of SORT_BY_ALIGNMENT and SORT_BY_INIT_PRIORITY on filenames.  These would
 166   previously be accepted but had no effect.
 167
 168 * The EXCLUDE_FILE directive can now be placed within any SORT_* directive
 169   within input section lists.
 170
 171 Changes in 2.29:
 172
 173 * Support for -z shstk in the x86 ELF linker to generate
 174   GNU_PROPERTY_X86_FEATURE_1_SHSTK in ELF GNU program properties.
 175
 176 * Add support for GNU_PROPERTY_X86_FEATURE_1_SHSTK in ELF GNU program
 177   properties in the x86 ELF linker.
 178
 179 * Add support for GNU_PROPERTY_X86_FEATURE_1_IBT in ELF GNU program
 180   properties in the x86 ELF linker.
 181
 182 * Support for -z ibtplt in the x86 ELF linker to generate IBT-enabled
 183   PLT.
 184
 185 * Support for -z ibt in the x86 ELF linker to generate IBT-enabled
 186   PLT as well as GNU_PROPERTY_X86_FEATURE_1_IBT in ELF GNU program
 187   properties.
 188
 189 * Add support for ELF SHF_GNU_MBIND and PT_GNU_MBIND_XXX.
 190
 191 * Add support for ELF GNU program properties.
 192
 193 * Add support for the Texas Instruments PRU processor.
 194
 195 * When configuring for arc*-*-linux* targets the default linker emulation will
 196   change if --with-cpu=nps400 is used at configure time.
 197
 198 * Improve assignment of LMAs to orphan sections in some edge cases where a
 199   mixture of both AT>LMA_REGION and AT(LMA) are used.
 200
 201 * Orphan sections placed after an empty section that has an AT(LMA) will now
 202   take an load memory address starting from LMA.
 203
 204 * Section groups can now be resolved (the group deleted and the group members
 205   placed like normal sections) at partial link time either using the new linker
 206   option --force-group-allocation or by placing FORCE_GROUP_ALLOCATION into the
 207   linker script.
 208
 209 Changes in 2.28:
 210
 211 * The EXCLUDE_FILE linker script construct can now be applied outside of the
 212   section list in order for the exclusions to apply over all input sections in
 213   the list.
 214
 215 * Add support for the RISC-V architecture.
 216
 217 * The command-line option --no-eh-frame-hdr can now be used in ELF based
 218   linkers to disable the automatic generation of .eh_frame_hdr sections.
 219
 220 * Add --in-implib=<infile> to the ARM linker to enable specifying a set of
 221   Secure Gateway veneers that must exist in the output import library specified
 222   by --out-implib=<outfile> and the address they must have.  As such,
 223   --in-implib is only supported in combination with --cmse-implib.
 224
 225 * Extended the --out-implib=<file> option, previously restricted to x86 PE
 226   targets, to any ELF based target.  This allows the generation of an import
 227   library for an ELF executable, which can then be used by another application
 228   to link against the executable.
 229
 230 Changes in 2.27:
 231
 232 * Add a configure option --enable-relro to decide whether -z relro should
 233   be enabled in ELF linker by default.  Default to yes for all Linux
 234   targets except FRV, HPPA, IA64 and MIPS.  Note that -z relro can increase
 235   disk and memory size.
 236
 237 * Support for -z noreloc-overflow in the x86-64 ELF linker to disable
 238   relocation overflow check.
 239
 240 * Add -z common/-z nocommon options for ELF targets to control whether to
 241   convert common symbols to the STT_COMMON type during a relocatable link.
 242
 243 * Support for -z nodynamic-undefined-weak in the x86 ELF linker, which
 244   avoids dynamic relocations against undefined weak symbols in executable.
 245
 246 * The NOCROSSREFSTO command was added to the linker script language.
 247
 248 * Add --no-apply-dynamic-relocs to the AArch64 linker to do not apply link-time
 249   values for dynamic relocations.
 250
 251 Changes in 2.26:
 252
 253 * Add --fix-stm32l4xx-629360 to the ARM linker to enable a link-time
 254   workaround for a bug in the bus matrix / memory controller for some of
 255   the STM32 Cortex-M4 based products (STM32L4xx)
 256
 257 * Add a configure option --enable-compressed-debug-sections={all,ld} to
 258   decide whether DWARF debug sections should be compressed by default.
 259
 260 * Add support for the ARC EM/HS, and ARC600/700 architectures.
 261
 262 * Experimental support for linker garbage collection (--gc-sections)
 263   has been enabled for COFF and PE based targets.
 264
 265 * New command-line option for ELF targets to compress DWARF debug
 266   sections, --compress-debug-sections=[none|zlib|zlib-gnu|zlib-gabi].
 267
 268 * New command-line option, --orphan-handling=[place|warn|error|discard], to
 269   adjust how orphan sections are handled.  The default is 'place' which gives
 270   the current behaviour, 'warn' and 'error' issue a warning or error
 271   respectively when orphan sections are found, and 'discard' will discard all
 272   orphan sections.
 273
 274 * Add support for LLVM plugin.
 275
 276 * Add --print-memory-usage option to report memory blocks usage.
 277
 278 * Add --require-defined option, it's like --undefined except the new symbol
 279   must be defined by the end of the link.
 280
 281 Changes in 2.25:
 282
 283 * PE binaries now once again contain real timestamps by default.  To disable
 284   the inclusion of a timestamp in a PE binary, use the --no-insert-timestamp
 285   command-line option.
 286
 287 * Replace support for openrisc and or32 with support for or1k.
 288
 289 * Add support for the --build-id command-line option to COFF based targets.
 290
 291 * x86/x86_64 pe-coff now supports the --build-id option.
 292
 293 * Add support for the Andes NDS32.
 294
 295 Changes in 2.24:
 296
 297 * Add LOG2CEIL() builtin function to the linker script language
 298
 299 * Add support for the Texas Instruments MSP430X processor.
 300
 301 * Add support for Altera Nios II.
 302
 303 * Add support for the V850E3V5 architecture.
 304
 305 * Add support for the Imagination Technologies Meta processor.
 306
 307 * --enable-new-dtags no longer generates old dtags in addition to new dtags.
 308
 309 * Remove linker support for MIPS ECOFF targets.
 310
 311 * Add ALIGN_WITH_INPUT to the linker script language to force the alignment of
 312   an output section to use the maximum alignment of all its input sections.
 313
 314 Changes in 2.23:
 315
 316 * Enable compressed debug section feature for x86/x86_64 pe-coff.
 317
 318 * Add support for the 64-bit ARM architecture: AArch64.
 319
 320 * Added SORT_NONE to the linker script language to disable section sorting.
 321
 322 * Add a linker-provided symbol when producing ELF output, '__ehdr_start'
 323   to point to the ELF file header (and nearby program headers) in the
 324   program's memory image.
 325
 326 * Add support for S12X processor.
 327
 328 * Add support for the VLE extension to the PowerPC architecture.
 329
 330 * Add support for the Freescale XGATE architecture.
 331
 332 * Add option -f FILE on AIX (for response file).
 333
 334 * Add support for the Renesas RL78 architecture.
 335
 336 * Add support for the Adapteva EPIPHANY architecture.
 337
 338 Changes in 2.22:
 339
 340 * --copy-dt-needed-entries is no longer enabled by default.  Instead
 341   --no-copy-dt-needed-entries is the default.
 342
 343 * INPUT_SECTION_FLAGS has been added to the linker script language
 344   to allow selection of input sections by section header section flags.
 345
 346 * Add support for the Tilera TILEPro and TILE-Gx architectures.
 347
 348 * Added SORT_BY_INIT_PRIORITY to the linker script language to permit
 349   sorting sections by numerical value of the GCC init_priority attribute
 350   encoded in the section name.
 351
 352 Changes in 2.21:
 353
 354 * Linker script expression evaluation is somewhat more sane.  This may
 355   break scripts that depend on quirks of the old expression evaluation.
 356
 357 * Turn off underscoring for x86_64 PE+-COFF targets.  For old behavior the
 358   option --enable-leading-mingw64-underscores can be used on configure of
 359   bfd.
 360
 361 * Add support for the TMS320C6000 (TI C6X) processor family.
 362
 363 * --add-needed renamed to --copy-dt-needed-entries in order to avoid confusion
 364   with --as-needed option.
 365
 366 * Extend .def file syntax by '== <ID>' for imports and exports. This allows
 367   to alias the import/export table name written in PE image.
 368
 369 * Add --exclude-all-symbols option to PE based linkers.  This prevents all
 370   symbols from automatically being exported.
 371
 372 * Add support for the Renesas RX processor.
 373
 374 * Add support for alpha-vms target.
 375
 376 Changes in 2.20:
 377
 378 * GNU/Linux targets now support the STB_GNU_UNIQUE symbol binding.  This is a
 379   GNU extension to the standard set of ELF symbol bindings.  The binding will
 380   be passed on to the dynamic linker which will make sure that in the entire
 381   process there is just one symbol with the given name and type in use.
 382
 383 * PE targets now support a GNU extension to allow the alignment of common
 384   common symbols to be specified.  This support uses custom options in
 385   the .drectve section, which will be disregarded by the native tools.
 386
 387 * PE targets now add primitive support for ELF version scripts; symbols
 388   are not versioned, but the local and global symbol visibility directives
 389   are respected when filtering symbols in auto-export mode.
 390
 391 * New option --no-export-dynamic to undo the effect of the -E and
 392   --export-dynamic options.
 393
 394 * ELF: --warn-alternate-em option to warn if an object has alternate
 395   ELF machine code.
 396
 397 * New script function REGION_ALIAS to add alias names to memory regions.
 398
 399 * PE targets no longer make use of the long section names PE extension to
 400   the COFF format when generating executable images, by default.  The old
 401   (slightly non-conformant) behaviour can still be invoked by using the
 402   new '--enable-long-section-names' command-line option.  It is also enabled
 403   automatically in the presence of un-stripped debug information, as GDB
 404   needs to be able to find the debug info sections by their full names.
 405
 406 * For GNU/Linux systems the linker will now avoid processing any relocations
 407   made against symbols of the STT_GNU_IFUNC type and instead emit them into
 408   the resulting binary for processing by the loader.
 409
 410 * --as-needed now links in a dynamic library if it satisfies undefined
 411   symbols in regular objects, or in other dynamic libraries.  In the
 412   latter case the library is not linked if it is found in a DT_NEEDED
 413   entry of one of the libraries already linked.
 414
 415 * Add a new command-line option, -Ttext-segment ADDR, for ELF targets
 416   to set the address of the first byte of the text segment.
 417
 418 * Add support for Sunplus score architecture.
 419
 420 * Add new option --use-nul-prefixed-import-tables to ld for PE targets to
 421   allow fallback to old import table generation with null element prefix.
 422
 423 * Windows PE systems now support a new --exclude-modules-for-implib option,
 424   allowing users to partition object files and archive members between a DLL
 425   and its associated import library as they are generated during linking.
 426
 427 * Add support for Lattice Mico32 (lm32) architecture.
 428
 429 * Add CR16 ELF --embedded-relocs (used to embedded relocations into binaries
 430   for Embedded-PIC code) option.
 431
 432 * Add to the PE/PE+ targets the support of two different kinds of
 433   pseudo-relocations.  They can be selected by the switches
 434   --enable-runtime-pseudo-reloc-v1 and --enable-runtime-pseudo-reloc-v2.
 435   For the switch --enable-runtime-pseudo-reloc it uses for 32-bit
 436   runtime pseudo relocation version one, for 64-bit the version two.
 437
 438 Changes in 2.19:
 439
 440 * Linker scripts support a new INSERT command that makes it easier to
 441   augment the default script.
 442
 443 * Linker script input section filespecs may now specify a file within an
 444   archive by writing "archive:file".
 445
 446 * The --sort-common switch now has an optional argument which specifies the
 447   direction of sorting.
 448
 449 * The M68K linker now supports multiple GOT generation schemes controlled via
 450   the --got=<type> command-line option.
 451
 452 * The ARM EABI linker will now generate stubs for function calls to symbols
 453   that are too far away.  The placement of the stubs is controlled by a new
 454   linker command-line option: --stub-group-size=N.
 455
 456 Changes in 2.18:
 457
 458 * Linker sources now released under version 3 of the GNU General Public
 459   License.
 460
 461 * ELF: New --build-id option to generate a unique per-binary identifier
 462   embedded in a note section.
 463
 464 * Added support for National Semicondutor CompactRISC (ie CR16) target.
 465
 466 * -l:foo now searches the library path for a filename called foo,
 467   without converting it to libfoo.a or libfoo.so.
 468
 469 * Add a new command-line option '--default-script=FILE' or '-dT FILE'
 470   which specifies a replacement for the built in, default linker
 471   script.
 472
 473 * ELF: Add -Bsymbolic-functions, --dynamic-list-cpp-new, which puts C++
 474   operator new and delete on the dynamic list, and --dynamic-list-data,
 475   builtin list for --dynamic-list, which puts global data symbols on the
 476   dynamic list.
 477
 478 * Add support for x86_64 PE+ target.
 479
 480 * Add support for Score target.
 481
 482 * ELF: Add --dynamic-list option to specify a list of global symbols
 483   whose references shouldn't be bound to the definition within the
 484   shared library, or a list of symbols which should be added to the
 485   symbol table in the executable.
 486
 487 * The default output section LMA has changed for allocatable sections from
 488   being equal to VMA, to keeping the difference between LMA and VMA the same as
 489   the previous output section in the same region.  This is a more useful
 490   default when using overlays and other cases where you specify an LMA
 491   differing from the VMA for some sections.
 492
 493 * New switch: --print-gc-sections to list any sections removed by garabge
 494   collection.
 495
 496 * ARM: Added --vfp11-denorm-fix option to work around an erratum in current
 497   VFP11 coprocessors.
 498
 499 Changes in 2.17:
 500
 501 * Support for the Infineon XC16X has been added by KPIT Cummins Infosystems.
 502
 503 * Modify the Linux linker search order to better match ld.so search order.
 504   Look for DT_NEEDED libraries in paths specified by ld.so.conf before
 505   searching the default directories, rather than vice versa.
 506   Use $prefix/etc/ld.so.conf if it exists, otherwise /etc/ld.so.conf.
 507
 508 * PE-COFF: Forward exports from DLL's can now be specified in .def files
 509   passed directly to ld.
 510
 511 * Support for the Z80 processor family has been added.
 512
 513 * Add support for the "@<file>" syntax to the command line, so that extra
 514   switches can be read from <file>.
 515
 516 Changes in 2.16:
 517
 518 * Support for the R_ARM_V4BX relocation as defined in the ARM AAELF
 519   specification has been added via the --fix-v4bx command-line option.
 520
 521 * New linker script construct AS_NEEDED(), which sets the --as-needed flag
 522   for input files listed inside of it.
 523
 524 * A new command-line option, --sysroot, can be used to override the
 525   default sysroot location.  It only applies to toolchains that were
 526   configured using --with-sysroot.
 527
 528 * New linker script functions: ORIGIN() and LENGTH() which return information
 529   about a specified memory region.
 530
 531 * Port to MAXQ processor contributed by HCL Tech.
 532
 533 * Added SEGMENT_START to the linker script language to permit the user to
 534   override the base address for a segment from the command-line.
 535
 536 * ELF: --warn-shared-textrel option to warn if adding a DT_TEXTREL to a shared
 537   object.
 538
 539 * Added SORT_BY_NAME and SORT_BY_ALIGNMENT to the linker script
 540   language to permit sorting sections by section name or section
 541   maximum alignment.
 542
 543 * Added a new linker command-line switch, --sort-section name|alignment,
 544   to sort sections by section name or maximum alignment.
 545
 546 * ELF: --add-needed/--no-add-needed options to control if a DT_NEEDED tag
 547   should be added when a shared library comes from DT_NEEDED tags.
 548
 549 * Support for the crx-elf target added.
 550
 551 * Support for the sh-symbianelf target added.
 552
 553 * A new linker command-line switch has been added which allows the hash table
 554   size to be set to a suitable prime value near to its argument.  This switch
 555   is --hash-size=<NUMBER>.  Also if the switch --reduce-memory-overheads is
 556   used, and --hash-size has not been used, then the default value will be set
 557   to 1021.
 558
 559 * Linker map files are now generated with an O(N) algorithm for finding symbols
 560   that are defined in each section.  This uses about 40% more memory for
 561   symbols than the old O(N^2) algorithm.  You can use the new
 562   --reduce-memory-overheads option to select the old algorithm; this option
 563   might also be used in the future to select similar tradeoffs.
 564
 565 Changes in 2.15:
 566
 567 * ELF: --as-needed/--no-as-needed options to control if a DT_NEEDED tag should
 568   be added only when a shared library is referenced.
 569
 570 * PE: --large-address-aware option to indicate executables support virtual
 571   addresses greater than 2 gigabytes.
 572
 573 * DWARF 2 support for i386pe added.
 574
 575 * The linker script operator DEFINED() will now yield 1 only for a symbol that
 576   is defined before the statement where DEFINED is used.
 577
 578 * The MIPS --embedded-relocs (used to embed relocations into binaries for
 579   Embedded-PIC code) is deprecated and will be removed in a future release.
 580
 581 * cr16c support added by NSC.
 582
 583 * m32r Linux (ELF) support added by Renesas.
 584
 585 * Improved linker's handling of unresolved symbols.  The switch
 586   --unresolved-symbols=<method> has been added to tell the linker when it
 587   should report them and the switch --warn-unresolved-symbols has been added to
 588   make reports be issued as warning messages rather than errors.
 589
 590 Changes in 2.14:
 591
 592 * Added support for Xtensa architecture.
 593
 594 * Added --with-sysroot configure switch to specify a target system root, for
 595   linking against a target filesystem image.
 596
 597 * Added --accept-unknown-linker-format to restore old linker behaviour (pre
 598   2.14) of silently accepting and linking in any files in an unknown binary
 599   file format.
 600
 601 * Added --no-omagic to undo the effects of the -N option.
 602
 603 * Support for Texas Instruments TMS320C4x and TMS320C3x series of
 604   DSP's contributed by Michael Hayes and Svein E. Seldal.
 605
 606 * Added --with-lib-path configure switch to specify default value for
 607   LIB_PATH.
 608
 609 * ARM port to QNX operating system added by Graeme Peterson.
 610
 611 * IP2K support added by Denis Chertykov.
 612
 613 Changes in 2.13:
 614
 615 * Support for the Fujitsu FRV architecture added by Red Hat. Models for FR400
 616   and FR500 included.
 617
 618 Changes in version 2.13:
 619
 620 * DEC VAX ELF support, by Matt Thomas.
 621
 622 Changes in version 2.12:
 623
 624 * Support for Don Knuth's MMIX, by Hans-Peter Nilsson.
 625
 626 * Support for the OpenRISC 32-bit embedded processor by OpenCores.
 627
 628 * Support for -z nocopyreloc in the x86 ELF linker, which disables
 629   production of copy relocs.  Warning: using this option may result in
 630   non-sharable applications.
 631
 632 * Support for -z combreloc in the ELF linker, which puts dynamic
 633   relocations against the same symbol together, so that dynamic linker
 634   can use an one-entry symbol lookup cache.
 635
 636 * Support for ELF SHF_MERGE section merging, by Jakub Jelinek.
 637
 638 Changes in version 2.11:
 639
 640 * Support for AMD x86-64 architecture, by Jan Hubicka, SuSE Labs.
 641
 642 * Support added for eliminating duplicate DWARF2 debug information by
 643   having the compiler generate the information in sections called
 644   .gnu.linkonce.wi.XXXX where XXXX is a checksum for the contents.  The
 645   linker then merges these sections together into the normal .debug_info
 646   section.
 647
 648 * The native ELF linker now searches the directories in DT_RUNPATH or
 649   DT_RPATH of a shared library for shared libraries needed by it.
 650
 651 * TI C54x support, by Timothy Wall.
 652
 653 * Added command-line switch --section-start to set the start address of any
 654   specified section.
 655
 656 * Added ability to emit full relocation information in linked executables,
 657   enabled by --emit-relocs.  Some post-linkage optimization tools need
 658   this information in order to be able to correctly identify and perform
 659   symbol relative addressing in the event of changes in section contents
 660   (instructions being added or deleted, extending data sections, etc.)
 661
 662 * Support for i860, by Jason Eckhardt (preliminary, alpha quality).
 663
 664 * Support for CRIS (Axis Communications ETRAX series).
 665
 666 * Support for PDP-11 and 2.11BSD a.out format, by Lars Brinkhoff.
 667
 668 Changes in version 2.10:
 669
 670 * Added AT> to the linker script language to allow load-time allocation of
 671   sections into regions.
 672
 673 * Added garbage collection of unused sections, enabled by --gc-sections.
 674   It does require a bit of backend support; currently implemented are
 675   arm-elf, avr-elf, d10v-elf, fr30-elf, i386-elf, m32r-elf, m68k-elf,
 676   mcore-elf, mips-elf, mn10300-elf, ppc-elf, sh-elf, sparc-elf, and v850-elf.
 677   Others will ignore the option.
 678
 679 * Added SORT to the linker script language to permit sorting sections by file
 680   name or section name.
 681
 682 * Added EXTERN to the linker script language as an equivalent to the -u
 683   command-line option.
 684
 685 * Added ASSERT to the linker script language.
 686
 687 * Added EXCLUDE_FILE to the linker script language for further control over
 688   wildcard file names.
 689
 690 * Added -O option to optimize linker output (as of this writing, this only
 691   affects ELF shared library generation).
 692
 693 * The -e option now accepts a number as well as a symbol name.
 694
 695 * Added --no-undefined option to disallow undefined symbols when creating a
 696   shared library.
 697
 698 * The linker now issues a warning, not an error, for an undefined symbol when
 699   using -Bsymbolic; use the new --no-undefined option to get the old
 700   behaviour.
 701
 702 * Added --demangle and --no-demangle options.
 703
 704 Changes in version 2.9:
 705
 706 * Added SQUAD to the linker script language.
 707
 708 * New option --no-warn-mismatch.
 709
 710 * The MEMORY command now parses the attributes to determine where sections that
 711   are not placed in a specific memory region are placed.
 712
 713 Changes in version 2.8:
 714
 715 * Linker scripts may now contain shell wildcard characters for file and section
 716   names.
 717
 718 * The linker now supports symbol versions in ELF.
 719
 720 * The NOCROSSREFS command was added to the linker script language.
 721
 722 * The LOADADDR expression was added to the linker script language.
 723
 724 * MAX and MIN functions were added to the linker script language.
 725
 726 * The OVERLAY construct was added to the linker script language.
 727
 728 * New option --warn-section-align to warn when the address of an output section
 729   changes due to alignment of an input section.
 730
 731 * New options --filter/-F and --auxiliary/-f.
 732
 733 Changes in version 2.7:
 734
 735 * New option --cref to print out a cross reference table.
 736
 737 * New option --wrap SYMBOL.
 738
 739 * New option --no-whole-archive, to turn off the effect of --whole-archive.
 740
 741 * Input sections assigned to the output section /DISCARD/ in the linker script
 742   are not included in the output file.
 743
 744 * The SunOS and ELF linkers now merge stabs debugging information which uses
 745   the N_BINCL and N_EINCL stab types.  This reduces the amount of debugging
 746   information generated.
 747
 748 Changes in version 2.6:
 749
 750 * When an ELF section name is representable as a C identifier (this is not true
 751 of most ELF section names), the linker will automatically define symbols
 752 __start_SECNAME and __stop_SECNAME, where SECNAME is the section name, at the
 753 beginning and the end of the section.  This is used by glibc.
 754
 755   Addendum: Current versions of the linker (at least for version 2.18 onwards
 756 and possibly much earlier as well) place two restrictions on this feature:  The
 757 symbols are only implemented for orphaned sections, not for explicitly placed
 758 sections and they are PROVIDEd rather than being defined.
 759
 760 * When an ELF section named .gnu.warning is encountered in an input file, the
 761 contents of the section are displayed as an error message, and the section is
 762 not copied into the output file.  This is used by glibc.
 763
 764 * When an ELF section named .gnu.warning.SYMBOL is encountered in an input
 765 file, and the symbol SYMBOL is referenced by some object file, the contents of
 766 the section are displayed as an error message.  The section is not copied into
 767 the output file, unless doing a relocatable or shared link.  This is used by
 768 glibc.
 769
 770 * New options -split-by-reloc and -split-by-file.
 771
 772 * The linker now supports linking PIC compiled code on SPARC SunOS.  It can
 773 also create SPARC SunOS shared libraries, and, like the native SunOS linker,
 774 will do so whenever there is an undefined symbol in the link and neither the -e
 775 nor the -r option was used.
 776
 777 * The -rpath option may be used on SunOS to set the list of directories to be
 778 searched at run time.  This overrides the default of building the list from the
 779 -L options.
 780
 781 * The COFF linker now combines debugging information for structs, unions, and
 782 enums, so that even if the same type is defined in multiple input files it will
 783 only be defined once in the output file.  The --traditional-format switch will
 784 prevent this optimization.
 785
 786 Changes in version 2.5:
 787
 788 * The linker now supports linking against SunOS shared libraries.  It still can
 789 not link SunOS PIC (Position Independent Code) files, so it can not be used to
 790 generate shared libraries.
 791
 792 * The linker now supports linking against ELF shared libraries for the i386
 793 (UnixWare) and SPARC (Solaris).  It can also link ELF PIC files, and can be
 794 used to generate shared libraries.  Shared library generation is not well
 795 tested; please report any problems encountered.  The linker is now enabled for
 796 Solaris again.
 797
 798 * Eric Youngdale has contributed Linux support code, including linking against
 799 Linux a.out shared libraries.  The linker produces Linux QMAGIC binaries.
 800
 801 * The ELF backend has been converted to the new linker code.  To use the new
 802 ELF linker, each particular target requires a relocation function.  So far,
 803 this function has been written for i386 (UnixWare), SPARC (Solaris) MIPS (Irix
 804 5), and HPPA ELF targets.
 805
 806 * The -( (--start-group) and -) (--end-group) options have been added to
 807 support searching a group of archives as though they were a single archive.
 808 This can also be used in a linker script, as GROUP ( files ).
 809
 810 * When a file is named on the command line, and the linker does not recognize
 811 it as an object file, the linker will now treat the file as a linker script
 812 file.  A linker script named in this way augments, but does not replace, the
 813 default linker script.
 814
 815 * The -warn-once option was added.  It causes the linker to only warn once per
 816 undefined symbol, rather than once per reference.
 817
 818 * The COFF backend has been converted to the new linker code.  As with ELF, to
 819 use the new linker, each particular target requires a relocation function.  So
 820 far, this function has been written for the i386, m68k, a29k and SH targets.
 821
 822 * The -V flag was made a synonym for -v, for SVR4 compatibility.  The old -V
 823 behaviour is available via --verbose.
 824
 825 Changes in version 2.4:
 826
 827 * New linker code, by Steve Chamberlain and Ian Taylor.  For a.out and ecoff
 828   formats (so far), this should result in considerable savings in time
 829   and memory used while linking; slightly poorer performance than
 830   before for formats not converted yet.
 831
 832 * Command-line parsing is no longer done with flex.  This means
 833   oddball characters in filenames won't get treated as argument
 834   separators.
 835
 836 * HP-PA ELF support, by Jeff Law.  (No SOM support yet.)
 837
 838 * Mach i386 support, by David Mackenzie.
 839
 840 * Irix 4 shared libraries are now supported (Irix 5 uses ELF, and ELF shared
 841   libraries are not yet supported).
 842
 843 * COFF shared libraries (as on SCO) should work as well.
 844
 845 * The linker is disabled for Solaris.  (Actually, it was in 2.3 also, I just
 846   forgot to note it.)  Some of their C library routines don't work when
 847   statically linked, and the GNU linker doesn't support dynamic linking yet.
 848
 849 Changes in version 2.3:
 850
 851 * Weak symbols are now supported.
 852
 853 * ELF support has been added.  The linker has been bootstrapped on
 854   UnixWare and Solaris.
 855
 856 * Alpha OSF/1 support has been added (non dynamic linking only).
 857
 858 Changes in version 2.2:
 859
 860 * The `bfd' library has been updated to reduce a.out-format string
 861   table size.  The effect of this is that files linked from many input
 862   files with duplicate symbols (`-g' debugging records, or identical
 863   static symbols) should be much smaller.
 864
 865 Changes in version 2.1:
 866
 867 * The ld -ySYMBOL flag (to trace references to SYMBOL) is now implemented.
 868
 869 * There is now support for writing ECOFF files, so ld and the
 870   other utilities should work on Risc/Ultrix and Irix.
 871
 872 \f
 873 Copyright (C) 2012-2021 Free Software Foundation, Inc.
 874
 875 Copying and distribution of this file, with or without modification,
 876 are permitted in any medium without royalty provided the copyright
 877 notice and this notice are preserved.
 878
 879 Local variables:
 880 fill-column: 79
 881 End: