ld/NEWS

   1 -*- text -*-
   2
   3 * Add support for S12X processor.
   4
   5 * Add support for the VLE extension to the PowerPC architecture.
   6
   7 * Add support for the Freescale XGATE architecture.
   8
   9 * Add option -f FILE on AIX (for response file).
  10
  11 * Add support for the Renesas RL78 architecture.
  12
  13 * Add support for the Adapteva EPIPHANY architecture.
  14
  15 Changes in 2.22:
  16
  17 * --copy-dt-needed-entries is no longer enabled by default.  Instead
  18   --no-copy-dt-needed-entries is the default.
  19
  20 * INPUT_SECTION_FLAGS has been added to the linker script language
  21   to allow selection of input sections by section header section flags.
  22
  23 * Add support for the Tilera TILEPro and TILE-Gx architectures.
  24
  25 * Added SORT_BY_INIT_PRIORITY to the linker script language to permit
  26   sorting sections by numerical value of the GCC init_priority attribute
  27   encoded in the section name.
  28
  29 Changes in 2.21:
  30
  31 * Linker script expression evaluation is somewhat more sane.  This may
  32   break scripts that depend on quirks of the old expression evaluation.
  33
  34 * Turn off underscoring for x86_64 PE+-COFF targets.  For old behavior the
  35   option --enable-leading-mingw64-underscores can be used on configure of
  36   bfd.
  37
  38 * Add support for the TMS320C6000 (TI C6X) processor family.
  39
  40 * --add-needed renamed to --copy-dt-needed-entries in order to avoid confusion
  41   with --as-needed option.
  42
  43 * Extend .def file syntax by '== <ID>' for imports and exports. This allows
  44   to alias the import/export table name written in PE image.
  45
  46 * Add --exclude-all-symbols option to PE based linkers.  This prevents all
  47   symbols from automatically being exported.
  48
  49 * Add support for the Renesas RX processor.
  50
  51 * Add support for alpha-vms target.
  52
  53 Changes in 2.20:
  54
  55 * GNU/Linux targets now support the STB_GNU_UNIQUE symbol binding.  This is a
  56   GNU extension to the standard set of ELF symbol bindings.  The binding will
  57   be passed on to the dynamic linker which will make sure that in the entire
  58   process there is just one symbol with the given name and type in use.
  59
  60 * PE targets now support a GNU extension to allow the alignment of common
  61   common symbols to be specified.  This support uses custom options in
  62   the .drectve section, which will be disregarded by the native tools.
  63
  64 * PE targets now add primitive support for ELF version scripts; symbols
  65   are not versioned, but the local and global symbol visibility directives
  66   are respected when filtering symbols in auto-export mode.
  67
  68 * New option --no-export-dynamic to undo the effect of the -E and
  69   --export-dynamic options.
  70
  71 * ELF: --warn-alternate-em option to warn if an object has alternate
  72   ELF machine code.
  73
  74 * New script function REGION_ALIAS to add alias names to memory regions.
  75
  76 * PE targets no longer make use of the long section names PE extension to
  77   the COFF format when generating executable images, by default.  The old
  78   (slightly non-conformant) behaviour can still be invoked by using the
  79   new '--enable-long-section-names' command-line option.  It is also enabled
  80   automatically in the presence of un-stripped debug information, as GDB
  81   needs to be able to find the debug info sections by their full names.
  82
  83 * For GNU/Linux systems the linker will now avoid processing any relocations
  84   made against symbols of the STT_GNU_IFUNC type and instead emit them into
  85   the resulting binary for processing by the loader.
  86
  87 * --as-needed now links in a dynamic library if it satisfies undefined
  88   symbols in regular objects, or in other dynamic libraries.  In the
  89   latter case the library is not linked if it is found in a DT_NEEDED
  90   entry of one of the libraries already linked.
  91
  92 * Add a new command line option, -Ttext-segment ADDR, for ELF targets
  93   to set the address of the first byte of the text segment.
  94
  95 * Add support for Sunplus score architecture.
  96
  97 * Add new option --use-nul-prefixed-import-tables to ld for PE targets to
  98   allow fallback to old import table generation with null element prefix.
  99
 100 * Windows PE systems now support a new --exclude-modules-for-implib option,
 101   allowing users to partition object files and archive members between a DLL
 102   and its associated import library as they are generated during linking.
 103
 104 * Add support for Lattice Mico32 (lm32) architecture.
 105
 106 * Add CR16 ELF --embedded-relocs (used to embedded relocations into binaries
 107   for Embedded-PIC code) option.
 108
 109 * Add to the PE/PE+ targets the support of two different kinds of
 110   pseudo-relocations.  They can be selected by the switches
 111   --enable-runtime-pseudo-reloc-v1 and --enable-runtime-pseudo-reloc-v2.
 112   For the switch --enable-runtime-pseudo-reloc it uses for 32-bit
 113   runtime pseudo relocation version one, for 64-bit the version two.
 114
 115 Changes in 2.19:
 116
 117 * Linker scripts support a new INSERT command that makes it easier to
 118   augment the default script.
 119
 120 * Linker script input section filespecs may now specify a file within an
 121   archive by writing "archive:file".
 122
 123 * The --sort-common switch now has an optional argument which specifies the
 124   direction of sorting.
 125
 126 * The M68K linker now supports multiple GOT generation schemes controlled via
 127   the --got=<type> command line option.
 128
 129 * The ARM EABI linker will now generate stubs for function calls to symbols
 130   that are too far away.  The placement of the stubs is controlled by a new
 131   linker command line option: --stub-group-size=N.
 132
 133 Changes in 2.18:
 134
 135 * Linker sources now released under version 3 of the GNU General Public
 136   License.
 137
 138 * ELF: New --build-id option to generate a unique per-binary identifier
 139   embedded in a note section.
 140
 141 * Added support for National Semicondutor CompactRISC (ie CR16) target.
 142
 143 * -l:foo now searches the library path for a filename called foo,
 144   without converting it to libfoo.a or libfoo.so.
 145
 146 * Add a new command line option '--default-script=FILE' or '-dT FILE'
 147   which specifies a replacement for the built in, default linker
 148   script.
 149
 150 * ELF: Add -Bsymbolic-functions, --dynamic-list-cpp-new, which puts C++
 151   operator new and delete on the dynamic list, and --dynamic-list-data,
 152   builtin list for --dynamic-list, which puts global data symbols on the
 153   dynamic list.
 154
 155 * Add support for x86_64 PE+ target.
 156
 157 * Add support for Score target.
 158
 159 * ELF: Add --dynamic-list option to specify a list of global symbols
 160   whose references shouldn't be bound to the definition within the
 161   shared library, or a list of symbols which should be added to the
 162   symbol table in the executable.
 163
 164 * The default output section LMA has changed for allocatable sections from
 165   being equal to VMA, to keeping the difference between LMA and VMA the same as
 166   the previous output section in the same region.  This is a more useful
 167   default when using overlays and other cases where you specify an LMA
 168   differing from the VMA for some sections.
 169
 170 * New switch: --print-gc-sections to list any sections removed by garabge
 171   collection.
 172
 173 * ARM: Added --vfp11-denorm-fix option to work around an erratum in current
 174   VFP11 coprocessors.
 175
 176 Changes in 2.17:
 177
 178 * Support for the Infineon XC16X has been added by KPIT Cummins Infosystems.
 179
 180 * Modify the Linux linker search order to better match ld.so search order.
 181   Look for DT_NEEDED libraries in paths specified by ld.so.conf before
 182   searching the default directories, rather than vice versa.
 183   Use $prefix/etc/ld.so.conf if it exists, otherwise /etc/ld.so.conf.
 184
 185 * PE-COFF: Forward exports from DLL's can now be specified in .def files
 186   passed directly to ld.
 187
 188 * Support for the Z80 processor family has been added.
 189
 190 * Add support for the "@<file>" syntax to the command line, so that extra
 191   switches can be read from <file>.
 192
 193 Changes in 2.16:
 194
 195 * Support for the R_ARM_V4BX relocation as defined in the ARM AAELF
 196   specification has been added via the --fix-v4bx command-line option.
 197
 198 * New linker script construct AS_NEEDED(), which sets the --as-needed flag
 199   for input files listed inside of it.
 200
 201 * A new command-line option, --sysroot, can be used to override the
 202   default sysroot location.  It only applies to toolchains that were
 203   configured using --with-sysroot.
 204
 205 * New linker script functions: ORIGIN() and LENGTH() which return information
 206   about a specified memory region.
 207
 208 * Port to MAXQ processor contributed by HCL Tech.
 209
 210 * Added SEGMENT_START to the linker script language to permit the user to
 211   override the base address for a segment from the command-line.
 212
 213 * ELF: --warn-shared-textrel option to warn if adding a DT_TEXTREL to a shared
 214   object.
 215
 216 * Added SORT_BY_NAME and SORT_BY_ALIGNMENT to the linker script
 217   language to permit sorting sections by section name or section
 218   maximum alignment.
 219
 220 * Added a new linker command line switch, --sort-section name|alignment,
 221   to sort sections by section name or maximum alignment.
 222
 223 * ELF: --add-needed/--no-add-needed options to control if a DT_NEEDED tag
 224   should be added when a shared library comes from DT_NEEDED tags.
 225
 226 * Support for the crx-elf target added.
 227
 228 * Support for the sh-symbianelf target added.
 229
 230 * A new linker command line switch has been added which allows the hash table
 231   size to be set to a suitable prime value near to its argument.  This switch
 232   is --hash-size=<NUMBER>.  Also if the switch --reduce-memory-overheads is
 233   used, and --hash-size has not been used, then the default value will be set
 234   to 1021.
 235
 236 * Linker map files are now generated with an O(N) algorithm for finding symbols
 237   that are defined in each section.  This uses about 40% more memory for
 238   symbols than the old O(N^2) algorithm.  You can use the new
 239   --reduce-memory-overheads option to select the old algorithm; this option
 240   might also be used in the future to select similar tradeoffs.
 241
 242 Changes in 2.15:
 243
 244 * ELF: --as-needed/--no-as-needed options to control if a DT_NEEDED tag should
 245   be added only when a shared library is referenced.
 246
 247 * PE: --large-address-aware option to indicate executables support virtual
 248   addresses greater than 2 gigabytes.
 249
 250 * DWARF 2 support for i386pe added.
 251
 252 * The linker script operator DEFINED() will now yield 1 only for a symbol that
 253   is defined before the statement where DEFINED is used.
 254
 255 * The MIPS --embedded-relocs (used to embed relocations into binaries for
 256   Embedded-PIC code) is deprecated and will be removed in a future release.
 257
 258 * cr16c support added by NSC.
 259
 260 * m32r Linux (ELF) support added by Renesas.
 261
 262 * Improved linker's handling of unresolved symbols.  The switch
 263   --unresolved-symbols=<method> has been added to tell the linker when it
 264   should report them and the switch --warn-unresolved-symbols has been added to
 265   make reports be issued as warning messages rather than errors.
 266
 267 Changes in 2.14:
 268
 269 * Added support for Xtensa architecture.
 270
 271 * Added --with-sysroot configure switch to specify a target system root, for
 272   linking against a target filesystem image.
 273
 274 * Added --accept-unknown-linker-format to restore old linker behaviour (pre
 275   2.14) of silently accepting and linking in any files in an unknown binary
 276   file format.
 277
 278 * Added --no-omagic to undo the effects of the -N option.
 279
 280 * Support for Texas Instruments TMS320C4x and TMS320C3x series of
 281   DSP's contributed by Michael Hayes and Svein E. Seldal.
 282
 283 * Added --with-lib-path configure switch to specify default value for
 284   LIB_PATH.
 285
 286 * ARM port to QNX operating system added by Graeme Peterson.
 287
 288 * IP2K support added by Denis Chertykov.
 289
 290 Changes in 2.13:
 291
 292 * Support for the Fujitsu FRV architecture added by Red Hat. Models for FR400
 293   and FR500 included.
 294
 295 Changes in version 2.13:
 296
 297 * DEC VAX ELF support, by Matt Thomas.
 298
 299 Changes in version 2.12:
 300
 301 * Support for Don Knuth's MMIX, by Hans-Peter Nilsson.
 302
 303 * Support for the OpenRISC 32-bit embedded processor by OpenCores.
 304
 305 * Support for -z nocopyreloc in the x86 ELF linker, which disables
 306   production of copy relocs.  Warning: using this option may result in
 307   non-sharable applications.
 308
 309 * Support for -z combreloc in the ELF linker, which puts dynamic
 310   relocations against the same symbol together, so that dynamic linker
 311   can use an one-entry symbol lookup cache.
 312
 313 * Support for ELF SHF_MERGE section merging, by Jakub Jelinek.
 314
 315 Changes in version 2.11:
 316
 317 * Support for AMD x86-64 architecture, by Jan Hubicka, SuSE Labs.
 318
 319 * Support added for eliminating duplicate DWARF2 debug information by
 320   having the compiler generate the information in sections called
 321   .gnu.linkonce.wi.XXXX where XXXX is a checksum for the contents.  The
 322   linker then merges these sections together into the normal .debug_info
 323   section.
 324
 325 * The native ELF linker now searches the directories in DT_RUNPATH or
 326   DT_RPATH of a shared library for shared libraries needed by it.
 327
 328 * TI C54x support, by Timothy Wall.
 329
 330 * Added command line switch --section-start to set the start address of any
 331   specified section.
 332
 333 * Added ability to emit full relocation information in linked executables,
 334   enabled by --emit-relocs.  Some post-linkage optimization tools need
 335   this information in order to be able to correctly identify and perform
 336   symbol relative addressing in the event of changes in section contents
 337   (instructions being added or deleted, extending data sections, etc.)
 338
 339 * Support for i860, by Jason Eckhardt (preliminary, alpha quality).
 340
 341 * Support for CRIS (Axis Communications ETRAX series).
 342
 343 * Support for PDP-11 and 2.11BSD a.out format, by Lars Brinkhoff.
 344
 345 Changes in version 2.10:
 346
 347 * Added AT> to the linker script language to allow load-time allocation of
 348   sections into regions.
 349
 350 * Added garbage collection of unused sections, enabled by --gc-sections.
 351   It does require a bit of backend support; currently implemented are
 352   arm-elf, avr-elf, d10v-elf, fr30-elf, i386-elf, m32r-elf, m68k-elf,
 353   mcore-elf, mips-elf, mn10300-elf, ppc-elf, sh-elf, sparc-elf, and v850-elf.
 354   Others will ignore the option.
 355
 356 * Added SORT to the linker script language to permit sorting sections by file
 357   name or section name.
 358
 359 * Added EXTERN to the linker script language as an equivalent to the -u
 360   command-line option.
 361
 362 * Added ASSERT to the linker script language.
 363
 364 * Added EXCLUDE_FILE to the linker script language for further control over
 365   wildcard file names.
 366
 367 * Added -O option to optimize linker output (as of this writing, this only
 368   affects ELF shared library generation).
 369
 370 * The -e option now accepts a number as well as a symbol name.
 371
 372 * Added --no-undefined option to disallow undefined symbols when creating a
 373   shared library.
 374
 375 * The linker now issues a warning, not an error, for an undefined symbol when
 376   using -Bsymbolic; use the new --no-undefined option to get the old
 377   behaviour.
 378
 379 * Added --demangle and --no-demangle options.
 380
 381 Changes in version 2.9:
 382
 383 * Added SQUAD to the linker script language.
 384
 385 * New option --no-warn-mismatch.
 386
 387 * The MEMORY command now parses the attributes to determine where sections that
 388   are not placed in a specific memory region are placed.
 389
 390 Changes in version 2.8:
 391
 392 * Linker scripts may now contain shell wildcard characters for file and section
 393   names.
 394
 395 * The linker now supports symbol versions in ELF.
 396
 397 * The NOCROSSREFS command was added to the linker script language.
 398
 399 * The LOADADDR expression was added to the linker script language.
 400
 401 * MAX and MIN functions were added to the linker script language.
 402
 403 * The OVERLAY construct was added to the linker script language.
 404
 405 * New option --warn-section-align to warn when the address of an output section
 406   changes due to alignment of an input section.
 407
 408 * New options --filter/-F and --auxiliary/-f.
 409
 410 Changes in version 2.7:
 411
 412 * New option --cref to print out a cross reference table.
 413
 414 * New option --wrap SYMBOL.
 415
 416 * New option --no-whole-archive, to turn off the effect of --whole-archive.
 417
 418 * Input sections assigned to the output section /DISCARD/ in the linker script
 419   are not included in the output file.
 420
 421 * The SunOS and ELF linkers now merge stabs debugging information which uses
 422   the N_BINCL and N_EINCL stab types.  This reduces the amount of debugging
 423   information generated.
 424
 425 Changes in version 2.6:
 426
 427 * When an ELF section name is representable as a C identifier (this is not true
 428 of most ELF section names), the linker will automatically define symbols
 429 __start_SECNAME and __stop_SECNAME, where SECNAME is the section name, at the
 430 beginning and the end of the section.  This is used by glibc.
 431
 432   Addendum: Current versions of the linker (at least for version 2.18 onwards
 433 and possibly much earlier as well) place two restrictions on this feature:  The
 434 symbols are only implemented for orphaned sections, not for explicitly placed
 435 sections and they are PROVIDEd rather than being defined.
 436
 437 * When an ELF section named .gnu.warning is encountered in an input file, the
 438 contents of the section are displayed as an error message, and the section is
 439 not copied into the output file.  This is used by glibc.
 440
 441 * When an ELF section named .gnu.warning.SYMBOL is encountered in an input
 442 file, and the symbol SYMBOL is referenced by some object file, the contents of
 443 the section are displayed as an error message.  The section is not copied into
 444 the output file, unless doing a relocatable or shared link.  This is used by
 445 glibc.
 446
 447 * New options -split-by-reloc and -split-by-file.
 448
 449 * The linker now supports linking PIC compiled code on SPARC SunOS.  It can
 450 also create SPARC SunOS shared libraries, and, like the native SunOS linker,
 451 will do so whenever there is an undefined symbol in the link and neither the -e
 452 nor the -r option was used.
 453
 454 * The -rpath option may be used on SunOS to set the list of directories to be
 455 searched at run time.  This overrides the default of building the list from the
 456 -L options.
 457
 458 * The COFF linker now combines debugging information for structs, unions, and
 459 enums, so that even if the same type is defined in multiple input files it will
 460 only be defined once in the output file.  The --traditional-format switch will
 461 prevent this optimization.
 462
 463 Changes in version 2.5:
 464
 465 * The linker now supports linking against SunOS shared libraries.  It still can
 466 not link SunOS PIC (Position Independent Code) files, so it can not be used to
 467 generate shared libraries.
 468
 469 * The linker now supports linking against ELF shared libraries for the i386
 470 (UnixWare) and SPARC (Solaris).  It can also link ELF PIC files, and can be
 471 used to generate shared libraries.  Shared library generation is not well
 472 tested; please report any problems encountered.  The linker is now enabled for
 473 Solaris again.
 474
 475 * Eric Youngdale has contributed Linux support code, including linking against
 476 Linux a.out shared libraries.  The linker produces Linux QMAGIC binaries.
 477
 478 * The ELF backend has been converted to the new linker code.  To use the new
 479 ELF linker, each particular target requires a relocation function.  So far,
 480 this function has been written for i386 (UnixWare), SPARC (Solaris) MIPS (Irix
 481 5), and HPPA ELF targets.
 482
 483 * The -( (--start-group) and -) (--end-group) options have been added to
 484 support searching a group of archives as though they were a single archive.
 485 This can also be used in a linker script, as GROUP ( files ).
 486
 487 * When a file is named on the command line, and the linker does not recognize
 488 it as an object file, the linker will now treat the file as a linker script
 489 file.  A linker script named in this way augments, but does not replace, the
 490 default linker script.
 491
 492 * The -warn-once option was added.  It causes the linker to only warn once per
 493 undefined symbol, rather than once per reference.
 494
 495 * The COFF backend has been converted to the new linker code.  As with ELF, to
 496 use the new linker, each particular target requires a relocation function.  So
 497 far, this function has been written for the i386, m68k, a29k and SH targets.
 498
 499 * The -V flag was made a synonym for -v, for SVR4 compatibility.  The old -V
 500 behaviour is available via --verbose.
 501
 502 Changes in version 2.4:
 503
 504 * New linker code, by Steve Chamberlain and Ian Taylor.  For a.out and ecoff
 505   formats (so far), this should result in considerable savings in time
 506   and memory used while linking; slightly poorer performance than
 507   before for formats not converted yet.
 508
 509 * Command-line parsing is no longer done with flex.  This means
 510   oddball characters in filenames won't get treated as argument
 511   separators.
 512
 513 * HP-PA ELF support, by Jeff Law.  (No SOM support yet.)
 514
 515 * Mach i386 support, by David Mackenzie.
 516
 517 * Irix 4 shared libraries are now supported (Irix 5 uses ELF, and ELF shared
 518   libraries are not yet supported).
 519
 520 * COFF shared libraries (as on SCO) should work as well.
 521
 522 * The linker is disabled for Solaris.  (Actually, it was in 2.3 also, I just
 523   forgot to note it.)  Some of their C library routines don't work when
 524   statically linked, and the GNU linker doesn't support dynamic linking yet.
 525
 526 Changes in version 2.3:
 527
 528 * Weak symbols are now supported.
 529
 530 * ELF support has been added.  The linker has been bootstrapped on
 531   UnixWare and Solaris.
 532
 533 * Alpha OSF/1 support has been added (non dynamic linking only).
 534
 535 Changes in version 2.2:
 536
 537 * The `bfd' library has been updated to reduce a.out-format string
 538   table size.  The effect of this is that files linked from many input
 539   files with duplicate symbols (`-g' debugging records, or identical
 540   static symbols) should be much smaller.
 541
 542 Changes in version 2.1:
 543
 544 * The ld -ySYMBOL flag (to trace references to SYMBOL) is now implemented.
 545
 546 * There is now support for writing ECOFF files, so ld and the
 547   other utilities should work on Risc/Ultrix and Irix.
 548
 549 \f
 550 Local variables:
 551 fill-column: 79
 552 End: