ld/NEWS

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