ld/NEWS

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