ld/NEWS

   1 -*- text -*-
   2
   3 * Add option -f FILE on AIX (for response file).
   4
   5 * Add support for the Renesas RL78 architecture.
   6
   7 * Add support for the Adapteva EPIPHANY architecture.
   8
   9 Changes in 2.22:
  10
  11 * --copy-dt-needed-entries is no longer enabled by default.  Instead
  12   --no-copy-dt-needed-entries is the default.
  13
  14 * INPUT_SECTION_FLAGS has been added to the linker script language
  15   to allow selection of input sections by section header section flags.
  16
  17 * Add support for the Tilera TILEPro and TILE-Gx architectures.
  18
  19 * Added SORT_BY_INIT_PRIORITY to the linker script language to permit
  20   sorting sections by numerical value of the GCC init_priority attribute
  21   encoded in the section name.
  22
  23 Changes in 2.21:
  24
  25 * Linker script expression evaluation is somewhat more sane.  This may
  26   break scripts that depend on quirks of the old expression evaluation.
  27
  28 * Turn off underscoring for x86_64 PE+-COFF targets.  For old behavior the
  29   option --enable-leading-mingw64-underscores can be used on configure of
  30   bfd.
  31
  32 * Add support for the TMS320C6000 (TI C6X) processor family.
  33
  34 * --add-needed renamed to --copy-dt-needed-entries in order to avoid confusion
  35   with --as-needed option.
  36
  37 * Extend .def file syntax by '== <ID>' for imports and exports. This allows
  38   to alias the import/export table name written in PE image.
  39
  40 * Add --exclude-all-symbols option to PE based linkers.  This prevents all
  41   symbols from automatically being exported.
  42
  43 * Add support for the Renesas RX processor.
  44
  45 * Add support for alpha-vms target.
  46
  47 Changes in 2.20:
  48
  49 * GNU/Linux targets now support the STB_GNU_UNIQUE symbol binding.  This is a
  50   GNU extension to the standard set of ELF symbol bindings.  The binding will
  51   be passed on to the dynamic linker which will make sure that in the entire
  52   process there is just one symbol with the given name and type in use.
  53
  54 * PE targets now support a GNU extension to allow the alignment of common
  55   common symbols to be specified.  This support uses custom options in
  56   the .drectve section, which will be disregarded by the native tools.
  57
  58 * PE targets now add primitive support for ELF version scripts; symbols
  59   are not versioned, but the local and global symbol visibility directives
  60   are respected when filtering symbols in auto-export mode.
  61
  62 * New option --no-export-dynamic to undo the effect of the -E and
  63   --export-dynamic options.
  64
  65 * ELF: --warn-alternate-em option to warn if an object has alternate
  66   ELF machine code.
  67
  68 * New script function REGION_ALIAS to add alias names to memory regions.
  69
  70 * PE targets no longer make use of the long section names PE extension to
  71   the COFF format when generating executable images, by default.  The old
  72   (slightly non-conformant) behaviour can still be invoked by using the
  73   new '--enable-long-section-names' command-line option.  It is also enabled
  74   automatically in the presence of un-stripped debug information, as GDB
  75   needs to be able to find the debug info sections by their full names.
  76
  77 * For GNU/Linux systems the linker will now avoid processing any relocations
  78   made against symbols of the STT_GNU_IFUNC type and instead emit them into
  79   the resulting binary for processing by the loader.
  80
  81 * --as-needed now links in a dynamic library if it satisfies undefined
  82   symbols in regular objects, or in other dynamic libraries.  In the
  83   latter case the library is not linked if it is found in a DT_NEEDED
  84   entry of one of the libraries already linked.
  85
  86 * Add a new command line option, -Ttext-segment ADDR, for ELF targets
  87   to set the address of the first byte of the text segment.
  88
  89 * Add support for Sunplus score architecture.
  90
  91 * Add new option --use-nul-prefixed-import-tables to ld for PE targets to
  92   allow fallback to old import table generation with null element prefix.
  93
  94 * Windows PE systems now support a new --exclude-modules-for-implib option,
  95   allowing users to partition object files and archive members between a DLL
  96   and its associated import library as they are generated during linking.
  97
  98 * Add support for Lattice Mico32 (lm32) architecture.
  99
 100 * Add CR16 ELF --embedded-relocs (used to embedded relocations into binaries
 101   for Embedded-PIC code) option.
 102
 103 * Add to the PE/PE+ targets the support of two different kinds of
 104   pseudo-relocations.  They can be selected by the switches
 105   --enable-runtime-pseudo-reloc-v1 and --enable-runtime-pseudo-reloc-v2.
 106   For the switch --enable-runtime-pseudo-reloc it uses for 32-bit
 107   runtime pseudo relocation version one, for 64-bit the version two.
 108
 109 Changes in 2.19:
 110
 111 * Linker scripts support a new INSERT command that makes it easier to
 112   augment the default script.
 113
 114 * Linker script input section filespecs may now specify a file within an
 115   archive by writing "archive:file".
 116
 117 * The --sort-common switch now has an optional argument which specifies the
 118   direction of sorting.
 119
 120 * The M68K linker now supports multiple GOT generation schemes controlled via
 121   the --got=<type> command line option.
 122
 123 * The ARM EABI linker will now generate stubs for function calls to symbols
 124   that are too far away.  The placement of the stubs is controlled by a new
 125   linker command line option: --stub-group-size=N.
 126
 127 Changes in 2.18:
 128
 129 * Linker sources now released under version 3 of the GNU General Public
 130   License.
 131
 132 * ELF: New --build-id option to generate a unique per-binary identifier
 133   embedded in a note section.
 134
 135 * Added support for National Semicondutor CompactRISC (ie CR16) target.
 136
 137 * -l:foo now searches the library path for a filename called foo,
 138   without converting it to libfoo.a or libfoo.so.
 139
 140 * Add a new command line option '--default-script=FILE' or '-dT FILE'
 141   which specifies a replacement for the built in, default linker
 142   script.
 143
 144 * ELF: Add -Bsymbolic-functions, --dynamic-list-cpp-new, which puts C++
 145   operator new and delete on the dynamic list, and --dynamic-list-data,
 146   builtin list for --dynamic-list, which puts global data symbols on the
 147   dynamic list.
 148
 149 * Add support for x86_64 PE+ target.
 150
 151 * Add support for Score target.
 152
 153 * ELF: Add --dynamic-list option to specify a list of global symbols
 154   whose references shouldn't be bound to the definition within the
 155   shared library, or a list of symbols which should be added to the
 156   symbol table in the executable.
 157
 158 * The default output section LMA has changed for allocatable sections from
 159   being equal to VMA, to keeping the difference between LMA and VMA the same as
 160   the previous output section in the same region.  This is a more useful
 161   default when using overlays and other cases where you specify an LMA
 162   differing from the VMA for some sections.
 163
 164 * New switch: --print-gc-sections to list any sections removed by garabge
 165   collection.
 166
 167 * ARM: Added --vfp11-denorm-fix option to work around an erratum in current
 168   VFP11 coprocessors.
 169
 170 Changes in 2.17:
 171
 172 * Support for the Infineon XC16X has been added by KPIT Cummins Infosystems.
 173
 174 * Modify the Linux linker search order to better match ld.so search order.
 175   Look for DT_NEEDED libraries in paths specified by ld.so.conf before
 176   searching the default directories, rather than vice versa.
 177   Use $prefix/etc/ld.so.conf if it exists, otherwise /etc/ld.so.conf.
 178
 179 * PE-COFF: Forward exports from DLL's can now be specified in .def files
 180   passed directly to ld.
 181
 182 * Support for the Z80 processor family has been added.
 183
 184 * Add support for the "@<file>" syntax to the command line, so that extra
 185   switches can be read from <file>.
 186
 187 Changes in 2.16:
 188
 189 * Support for the R_ARM_V4BX relocation as defined in the ARM AAELF
 190   specification has been added via the --fix-v4bx command-line option.
 191
 192 * New linker script construct AS_NEEDED(), which sets the --as-needed flag
 193   for input files listed inside of it.
 194
 195 * A new command-line option, --sysroot, can be used to override the
 196   default sysroot location.  It only applies to toolchains that were
 197   configured using --with-sysroot.
 198
 199 * New linker script functions: ORIGIN() and LENGTH() which return information
 200   about a specified memory region.
 201
 202 * Port to MAXQ processor contributed by HCL Tech.
 203
 204 * Added SEGMENT_START to the linker script language to permit the user to
 205   override the base address for a segment from the command-line.
 206
 207 * ELF: --warn-shared-textrel option to warn if adding a DT_TEXTREL to a shared
 208   object.
 209
 210 * Added SORT_BY_NAME and SORT_BY_ALIGNMENT to the linker script
 211   language to permit sorting sections by section name or section
 212   maximum alignment.
 213
 214 * Added a new linker command line switch, --sort-section name|alignment,
 215   to sort sections by section name or maximum alignment.
 216
 217 * ELF: --add-needed/--no-add-needed options to control if a DT_NEEDED tag
 218   should be added when a shared library comes from DT_NEEDED tags.
 219
 220 * Support for the crx-elf target added.
 221
 222 * Support for the sh-symbianelf target added.
 223
 224 * A new linker command line switch has been added which allows the hash table
 225   size to be set to a suitable prime value near to its argument.  This switch
 226   is --hash-size=<NUMBER>.  Also if the switch --reduce-memory-overheads is
 227   used, and --hash-size has not been used, then the default value will be set
 228   to 1021.
 229
 230 * Linker map files are now generated with an O(N) algorithm for finding symbols
 231   that are defined in each section.  This uses about 40% more memory for
 232   symbols than the old O(N^2) algorithm.  You can use the new
 233   --reduce-memory-overheads option to select the old algorithm; this option
 234   might also be used in the future to select similar tradeoffs.
 235
 236 Changes in 2.15:
 237
 238 * ELF: --as-needed/--no-as-needed options to control if a DT_NEEDED tag should
 239   be added only when a shared library is referenced.
 240
 241 * PE: --large-address-aware option to indicate executables support virtual
 242   addresses greater than 2 gigabytes.
 243
 244 * DWARF 2 support for i386pe added.
 245
 246 * The linker script operator DEFINED() will now yield 1 only for a symbol that
 247   is defined before the statement where DEFINED is used.
 248
 249 * The MIPS --embedded-relocs (used to embed relocations into binaries for
 250   Embedded-PIC code) is deprecated and will be removed in a future release.
 251
 252 * cr16c support added by NSC.
 253
 254 * m32r Linux (ELF) support added by Renesas.
 255
 256 * Improved linker's handling of unresolved symbols.  The switch
 257   --unresolved-symbols=<method> has been added to tell the linker when it
 258   should report them and the switch --warn-unresolved-symbols has been added to
 259   make reports be issued as warning messages rather than errors.
 260
 261 Changes in 2.14:
 262
 263 * Added support for Xtensa architecture.
 264
 265 * Added --with-sysroot configure switch to specify a target system root, for
 266   linking against a target filesystem image.
 267
 268 * Added --accept-unknown-linker-format to restore old linker behaviour (pre
 269   2.14) of silently accepting and linking in any files in an unknown binary
 270   file format.
 271
 272 * Added --no-omagic to undo the effects of the -N option.
 273
 274 * Support for Texas Instruments TMS320C4x and TMS320C3x series of
 275   DSP's contributed by Michael Hayes and Svein E. Seldal.
 276
 277 * Added --with-lib-path configure switch to specify default value for
 278   LIB_PATH.
 279
 280 * ARM port to QNX operating system added by Graeme Peterson.
 281
 282 * IP2K support added by Denis Chertykov.
 283
 284 Changes in 2.13:
 285
 286 * Support for the Fujitsu FRV architecture added by Red Hat. Models for FR400
 287   and FR500 included.
 288
 289 Changes in version 2.13:
 290
 291 * DEC VAX ELF support, by Matt Thomas.
 292
 293 Changes in version 2.12:
 294
 295 * Support for Don Knuth's MMIX, by Hans-Peter Nilsson.
 296
 297 * Support for the OpenRISC 32-bit embedded processor by OpenCores.
 298
 299 * Support for -z nocopyreloc in the x86 ELF linker, which disables
 300   production of copy relocs.  Warning: using this option may result in
 301   non-sharable applications.
 302
 303 * Support for -z combreloc in the ELF linker, which puts dynamic
 304   relocations against the same symbol together, so that dynamic linker
 305   can use an one-entry symbol lookup cache.
 306
 307 * Support for ELF SHF_MERGE section merging, by Jakub Jelinek.
 308
 309 Changes in version 2.11:
 310
 311 * Support for AMD x86-64 architecture, by Jan Hubicka, SuSE Labs.
 312
 313 * Support added for eliminating duplicate DWARF2 debug information by
 314   having the compiler generate the information in sections called
 315   .gnu.linkonce.wi.XXXX where XXXX is a checksum for the contents.  The
 316   linker then merges these sections together into the normal .debug_info
 317   section.
 318
 319 * The native ELF linker now searches the directories in DT_RUNPATH or
 320   DT_RPATH of a shared library for shared libraries needed by it.
 321
 322 * TI C54x support, by Timothy Wall.
 323
 324 * Added command line switch --section-start to set the start address of any
 325   specified section.
 326
 327 * Added ability to emit full relocation information in linked executables,
 328   enabled by --emit-relocs.  Some post-linkage optimization tools need
 329   this information in order to be able to correctly identify and perform
 330   symbol relative addressing in the event of changes in section contents
 331   (instructions being added or deleted, extending data sections, etc.)
 332
 333 * Support for i860, by Jason Eckhardt (preliminary, alpha quality).
 334
 335 * Support for CRIS (Axis Communications ETRAX series).
 336
 337 * Support for PDP-11 and 2.11BSD a.out format, by Lars Brinkhoff.
 338
 339 Changes in version 2.10:
 340
 341 * Added AT> to the linker script language to allow load-time allocation of
 342   sections into regions.
 343
 344 * Added garbage collection of unused sections, enabled by --gc-sections.
 345   It does require a bit of backend support; currently implemented are
 346   arm-elf, avr-elf, d10v-elf, fr30-elf, i386-elf, m32r-elf, m68k-elf,
 347   mcore-elf, mips-elf, mn10300-elf, ppc-elf, sh-elf, sparc-elf, and v850-elf.
 348   Others will ignore the option.
 349
 350 * Added SORT to the linker script language to permit sorting sections by file
 351   name or section name.
 352
 353 * Added EXTERN to the linker script language as an equivalent to the -u
 354   command-line option.
 355
 356 * Added ASSERT to the linker script language.
 357
 358 * Added EXCLUDE_FILE to the linker script language for further control over
 359   wildcard file names.
 360
 361 * Added -O option to optimize linker output (as of this writing, this only
 362   affects ELF shared library generation).
 363
 364 * The -e option now accepts a number as well as a symbol name.
 365
 366 * Added --no-undefined option to disallow undefined symbols when creating a
 367   shared library.
 368
 369 * The linker now issues a warning, not an error, for an undefined symbol when
 370   using -Bsymbolic; use the new --no-undefined option to get the old
 371   behaviour.
 372
 373 * Added --demangle and --no-demangle options.
 374
 375 Changes in version 2.9:
 376
 377 * Added SQUAD to the linker script language.
 378
 379 * New option --no-warn-mismatch.
 380
 381 * The MEMORY command now parses the attributes to determine where sections that
 382   are not placed in a specific memory region are placed.
 383
 384 Changes in version 2.8:
 385
 386 * Linker scripts may now contain shell wildcard characters for file and section
 387   names.
 388
 389 * The linker now supports symbol versions in ELF.
 390
 391 * The NOCROSSREFS command was added to the linker script language.
 392
 393 * The LOADADDR expression was added to the linker script language.
 394
 395 * MAX and MIN functions were added to the linker script language.
 396
 397 * The OVERLAY construct was added to the linker script language.
 398
 399 * New option --warn-section-align to warn when the address of an output section
 400   changes due to alignment of an input section.
 401
 402 * New options --filter/-F and --auxiliary/-f.
 403
 404 Changes in version 2.7:
 405
 406 * New option --cref to print out a cross reference table.
 407
 408 * New option --wrap SYMBOL.
 409
 410 * New option --no-whole-archive, to turn off the effect of --whole-archive.
 411
 412 * Input sections assigned to the output section /DISCARD/ in the linker script
 413   are not included in the output file.
 414
 415 * The SunOS and ELF linkers now merge stabs debugging information which uses
 416   the N_BINCL and N_EINCL stab types.  This reduces the amount of debugging
 417   information generated.
 418
 419 Changes in version 2.6:
 420
 421 * When an ELF section name is representable as a C identifier (this is not true
 422 of most ELF section names), the linker will automatically define symbols
 423 __start_SECNAME and __stop_SECNAME, where SECNAME is the section name, at the
 424 beginning and the end of the section.  This is used by glibc.
 425
 426   Addendum: Current versions of the linker (at least for version 2.18 onwards
 427 and possibly much earlier as well) place two restrictions on this feature:  The
 428 symbols are only implemented for orphaned sections, not for explicitly placed
 429 sections and they are PROVIDEd rather than being defined.
 430
 431 * When an ELF section named .gnu.warning is encountered in an input file, the
 432 contents of the section are displayed as an error message, and the section is
 433 not copied into the output file.  This is used by glibc.
 434
 435 * When an ELF section named .gnu.warning.SYMBOL is encountered in an input
 436 file, and the symbol SYMBOL is referenced by some object file, the contents of
 437 the section are displayed as an error message.  The section is not copied into
 438 the output file, unless doing a relocatable or shared link.  This is used by
 439 glibc.
 440
 441 * New options -split-by-reloc and -split-by-file.
 442
 443 * The linker now supports linking PIC compiled code on SPARC SunOS.  It can
 444 also create SPARC SunOS shared libraries, and, like the native SunOS linker,
 445 will do so whenever there is an undefined symbol in the link and neither the -e
 446 nor the -r option was used.
 447
 448 * The -rpath option may be used on SunOS to set the list of directories to be
 449 searched at run time.  This overrides the default of building the list from the
 450 -L options.
 451
 452 * The COFF linker now combines debugging information for structs, unions, and
 453 enums, so that even if the same type is defined in multiple input files it will
 454 only be defined once in the output file.  The --traditional-format switch will
 455 prevent this optimization.
 456
 457 Changes in version 2.5:
 458
 459 * The linker now supports linking against SunOS shared libraries.  It still can
 460 not link SunOS PIC (Position Independent Code) files, so it can not be used to
 461 generate shared libraries.
 462
 463 * The linker now supports linking against ELF shared libraries for the i386
 464 (UnixWare) and SPARC (Solaris).  It can also link ELF PIC files, and can be
 465 used to generate shared libraries.  Shared library generation is not well
 466 tested; please report any problems encountered.  The linker is now enabled for
 467 Solaris again.
 468
 469 * Eric Youngdale has contributed Linux support code, including linking against
 470 Linux a.out shared libraries.  The linker produces Linux QMAGIC binaries.
 471
 472 * The ELF backend has been converted to the new linker code.  To use the new
 473 ELF linker, each particular target requires a relocation function.  So far,
 474 this function has been written for i386 (UnixWare), SPARC (Solaris) MIPS (Irix
 475 5), and HPPA ELF targets.
 476
 477 * The -( (--start-group) and -) (--end-group) options have been added to
 478 support searching a group of archives as though they were a single archive.
 479 This can also be used in a linker script, as GROUP ( files ).
 480
 481 * When a file is named on the command line, and the linker does not recognize
 482 it as an object file, the linker will now treat the file as a linker script
 483 file.  A linker script named in this way augments, but does not replace, the
 484 default linker script.
 485
 486 * The -warn-once option was added.  It causes the linker to only warn once per
 487 undefined symbol, rather than once per reference.
 488
 489 * The COFF backend has been converted to the new linker code.  As with ELF, to
 490 use the new linker, each particular target requires a relocation function.  So
 491 far, this function has been written for the i386, m68k, a29k and SH targets.
 492
 493 * The -V flag was made a synonym for -v, for SVR4 compatibility.  The old -V
 494 behaviour is available via --verbose.
 495
 496 Changes in version 2.4:
 497
 498 * New linker code, by Steve Chamberlain and Ian Taylor.  For a.out and ecoff
 499   formats (so far), this should result in considerable savings in time
 500   and memory used while linking; slightly poorer performance than
 501   before for formats not converted yet.
 502
 503 * Command-line parsing is no longer done with flex.  This means
 504   oddball characters in filenames won't get treated as argument
 505   separators.
 506
 507 * HP-PA ELF support, by Jeff Law.  (No SOM support yet.)
 508
 509 * Mach i386 support, by David Mackenzie.
 510
 511 * Irix 4 shared libraries are now supported (Irix 5 uses ELF, and ELF shared
 512   libraries are not yet supported).
 513
 514 * COFF shared libraries (as on SCO) should work as well.
 515
 516 * The linker is disabled for Solaris.  (Actually, it was in 2.3 also, I just
 517   forgot to note it.)  Some of their C library routines don't work when
 518   statically linked, and the GNU linker doesn't support dynamic linking yet.
 519
 520 Changes in version 2.3:
 521
 522 * Weak symbols are now supported.
 523
 524 * ELF support has been added.  The linker has been bootstrapped on
 525   UnixWare and Solaris.
 526
 527 * Alpha OSF/1 support has been added (non dynamic linking only).
 528
 529 Changes in version 2.2:
 530
 531 * The `bfd' library has been updated to reduce a.out-format string
 532   table size.  The effect of this is that files linked from many input
 533   files with duplicate symbols (`-g' debugging records, or identical
 534   static symbols) should be much smaller.
 535
 536 Changes in version 2.1:
 537
 538 * The ld -ySYMBOL flag (to trace references to SYMBOL) is now implemented.
 539
 540 * There is now support for writing ECOFF files, so ld and the
 541   other utilities should work on Risc/Ultrix and Irix.
 542
 543 \f
 544 Local variables:
 545 fill-column: 79
 546 End: