ld/NEWS

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