| 1 | -*- text -*- |
| 2 | |
| 3 | Changes in 2.31: |
| 4 | |
| 5 | * Speed up direct linking with DLLs for Cygwin and Mingw targets. |
| 6 | |
| 7 | * Add a configure option --enable-separate-code to decide whether |
| 8 | -z separate-code should be enabled in ELF linker by default. Default |
| 9 | to yes for Linux/x86 targets. Note that -z separate-code can increase |
| 10 | disk and memory size. |
| 11 | |
| 12 | Changes in 2.30: |
| 13 | |
| 14 | * Add -z separate-code to generate separate code PT_LOAD segment. |
| 15 | |
| 16 | * Add "-z undefs" command-line option as the inverse of the "-z defs" option. |
| 17 | |
| 18 | * Add -z globalaudit command-line option to force audit libraries to be run |
| 19 | for every dynamic object loaded by an executable - provided that the loader |
| 20 | supports this functionality. |
| 21 | |
| 22 | * Tighten linker script grammar around file name specifiers to prevent the use |
| 23 | of SORT_BY_ALIGNMENT and SORT_BY_INIT_PRIORITY on filenames. These would |
| 24 | previously be accepted but had no effect. |
| 25 | |
| 26 | * The EXCLUDE_FILE directive can now be placed within any SORT_* directive |
| 27 | within input section lists. |
| 28 | |
| 29 | Changes in 2.29: |
| 30 | |
| 31 | * Support for -z shstk in the x86 ELF linker to generate |
| 32 | GNU_PROPERTY_X86_FEATURE_1_SHSTK in ELF GNU program properties. |
| 33 | |
| 34 | * Add support for GNU_PROPERTY_X86_FEATURE_1_SHSTK in ELF GNU program |
| 35 | properties in the x86 ELF linker. |
| 36 | |
| 37 | * Add support for GNU_PROPERTY_X86_FEATURE_1_IBT in ELF GNU program |
| 38 | properties in the x86 ELF linker. |
| 39 | |
| 40 | * Support for -z ibtplt in the x86 ELF linker to generate IBT-enabled |
| 41 | PLT. |
| 42 | |
| 43 | * Support for -z ibt in the x86 ELF linker to generate IBT-enabled |
| 44 | PLT as well as GNU_PROPERTY_X86_FEATURE_1_IBT in ELF GNU program |
| 45 | properties. |
| 46 | |
| 47 | * Add support for ELF SHF_GNU_MBIND and PT_GNU_MBIND_XXX. |
| 48 | |
| 49 | * Add support for ELF GNU program properties. |
| 50 | |
| 51 | * Add support for the Texas Instruments PRU processor. |
| 52 | |
| 53 | * When configuring for arc*-*-linux* targets the default linker emulation will |
| 54 | change if --with-cpu=nps400 is used at configure time. |
| 55 | |
| 56 | * Improve assignment of LMAs to orphan sections in some edge cases where a |
| 57 | mixture of both AT>LMA_REGION and AT(LMA) are used. |
| 58 | |
| 59 | * Orphan sections placed after an empty section that has an AT(LMA) will now |
| 60 | take an load memory address starting from LMA. |
| 61 | |
| 62 | * Section groups can now be resolved (the group deleted and the group members |
| 63 | placed like normal sections) at partial link time either using the new linker |
| 64 | option --force-group-allocation or by placing FORCE_GROUP_ALLOCATION into the |
| 65 | linker script. |
| 66 | |
| 67 | Changes in 2.28: |
| 68 | |
| 69 | * The EXCLUDE_FILE linker script construct can now be applied outside of the |
| 70 | section list in order for the exclusions to apply over all input sections in |
| 71 | the list. |
| 72 | |
| 73 | * Add support for the RISC-V architecture. |
| 74 | |
| 75 | * The command-line option --no-eh-frame-hdr can now be used in ELF based |
| 76 | linkers to disable the automatic generation of .eh_frame_hdr sections. |
| 77 | |
| 78 | * Add --in-implib=<infile> to the ARM linker to enable specifying a set of |
| 79 | Secure Gateway veneers that must exist in the output import library specified |
| 80 | by --out-implib=<outfile> and the address they must have. As such, |
| 81 | --in-implib is only supported in combination with --cmse-implib. |
| 82 | |
| 83 | * Extended the --out-implib=<file> option, previously restricted to x86 PE |
| 84 | targets, to any ELF based target. This allows the generation of an import |
| 85 | library for an ELF executable, which can then be used by another application |
| 86 | to link against the executable. |
| 87 | |
| 88 | Changes in 2.27: |
| 89 | |
| 90 | * Add a configure option --enable-relro to decide whether -z relro should |
| 91 | be enabled in ELF linker by default. Default to yes for all Linux |
| 92 | targets except FRV, HPPA, IA64 and MIPS. Note that -z relro can increase |
| 93 | disk and memory size. |
| 94 | |
| 95 | * Support for -z noreloc-overflow in the x86-64 ELF linker to disable |
| 96 | relocation overflow check. |
| 97 | |
| 98 | * Add -z common/-z nocommon options for ELF targets to control whether to |
| 99 | convert common symbols to the STT_COMMON type during a relocatable link. |
| 100 | |
| 101 | * Support for -z nodynamic-undefined-weak in the x86 ELF linker, which |
| 102 | avoids dynamic relocations against undefined weak symbols in executable. |
| 103 | |
| 104 | * The NOCROSSREFSTO command was added to the linker script language. |
| 105 | |
| 106 | * Add --no-apply-dynamic-relocs to the AArch64 linker to do not apply link-time |
| 107 | values for dynamic relocations. |
| 108 | |
| 109 | Changes in 2.26: |
| 110 | |
| 111 | * Add --fix-stm32l4xx-629360 to the ARM linker to enable a link-time |
| 112 | workaround for a bug in the bus matrix / memory controller for some of |
| 113 | the STM32 Cortex-M4 based products (STM32L4xx) |
| 114 | |
| 115 | * Add a configure option --enable-compressed-debug-sections={all,ld} to |
| 116 | decide whether DWARF debug sections should be compressed by default. |
| 117 | |
| 118 | * Add support for the ARC EM/HS, and ARC600/700 architectures. |
| 119 | |
| 120 | * Experimental support for linker garbage collection (--gc-sections) |
| 121 | has been enabled for COFF and PE based targets. |
| 122 | |
| 123 | * New command-line option for ELF targets to compress DWARF debug |
| 124 | sections, --compress-debug-sections=[none|zlib|zlib-gnu|zlib-gabi]. |
| 125 | |
| 126 | * New command-line option, --orphan-handling=[place|warn|error|discard], to |
| 127 | adjust how orphan sections are handled. The default is 'place' which gives |
| 128 | the current behaviour, 'warn' and 'error' issue a warning or error |
| 129 | respectively when orphan sections are found, and 'discard' will discard all |
| 130 | orphan sections. |
| 131 | |
| 132 | * Add support for LLVM plugin. |
| 133 | |
| 134 | * Add --print-memory-usage option to report memory blocks usage. |
| 135 | |
| 136 | * Add --require-defined option, it's like --undefined except the new symbol |
| 137 | must be defined by the end of the link. |
| 138 | |
| 139 | Changes in 2.25: |
| 140 | |
| 141 | * PE binaries now once again contain real timestamps by default. To disable |
| 142 | the inclusion of a timestamp in a PE binary, use the --no-insert-timestamp |
| 143 | command-line option. |
| 144 | |
| 145 | * Replace support for openrisc and or32 with support for or1k. |
| 146 | |
| 147 | * Add support for the --build-id command-line option to COFF based targets. |
| 148 | |
| 149 | * x86/x86_64 pe-coff now supports the --build-id option. |
| 150 | |
| 151 | * Add support for the Andes NDS32. |
| 152 | |
| 153 | Changes in 2.24: |
| 154 | |
| 155 | * Add LOG2CEIL() builtin function to the linker script language |
| 156 | |
| 157 | * Add support for the Texas Instruments MSP430X processor. |
| 158 | |
| 159 | * Add support for Altera Nios II. |
| 160 | |
| 161 | * Add support for the V850E3V5 architecture. |
| 162 | |
| 163 | * Add support for the Imagination Technologies Meta processor. |
| 164 | |
| 165 | * --enable-new-dtags no longer generates old dtags in addition to new dtags. |
| 166 | |
| 167 | * Remove linker support for MIPS ECOFF targets. |
| 168 | |
| 169 | * Add ALIGN_WITH_INPUT to the linker script language to force the alignment of |
| 170 | an output section to use the maximum alignment of all its input sections. |
| 171 | |
| 172 | Changes in 2.23: |
| 173 | |
| 174 | * Enable compressed debug section feature for x86/x86_64 pe-coff. |
| 175 | |
| 176 | * Add support for the 64-bit ARM architecture: AArch64. |
| 177 | |
| 178 | * Added SORT_NONE to the linker script language to disable section sorting. |
| 179 | |
| 180 | * Add a linker-provided symbol when producing ELF output, '__ehdr_start' |
| 181 | to point to the ELF file header (and nearby program headers) in the |
| 182 | program's memory image. |
| 183 | |
| 184 | * Add support for S12X processor. |
| 185 | |
| 186 | * Add support for the VLE extension to the PowerPC architecture. |
| 187 | |
| 188 | * Add support for the Freescale XGATE architecture. |
| 189 | |
| 190 | * Add option -f FILE on AIX (for response file). |
| 191 | |
| 192 | * Add support for the Renesas RL78 architecture. |
| 193 | |
| 194 | * Add support for the Adapteva EPIPHANY architecture. |
| 195 | |
| 196 | Changes in 2.22: |
| 197 | |
| 198 | * --copy-dt-needed-entries is no longer enabled by default. Instead |
| 199 | --no-copy-dt-needed-entries is the default. |
| 200 | |
| 201 | * INPUT_SECTION_FLAGS has been added to the linker script language |
| 202 | to allow selection of input sections by section header section flags. |
| 203 | |
| 204 | * Add support for the Tilera TILEPro and TILE-Gx architectures. |
| 205 | |
| 206 | * Added SORT_BY_INIT_PRIORITY to the linker script language to permit |
| 207 | sorting sections by numerical value of the GCC init_priority attribute |
| 208 | encoded in the section name. |
| 209 | |
| 210 | Changes in 2.21: |
| 211 | |
| 212 | * Linker script expression evaluation is somewhat more sane. This may |
| 213 | break scripts that depend on quirks of the old expression evaluation. |
| 214 | |
| 215 | * Turn off underscoring for x86_64 PE+-COFF targets. For old behavior the |
| 216 | option --enable-leading-mingw64-underscores can be used on configure of |
| 217 | bfd. |
| 218 | |
| 219 | * Add support for the TMS320C6000 (TI C6X) processor family. |
| 220 | |
| 221 | * --add-needed renamed to --copy-dt-needed-entries in order to avoid confusion |
| 222 | with --as-needed option. |
| 223 | |
| 224 | * Extend .def file syntax by '== <ID>' for imports and exports. This allows |
| 225 | to alias the import/export table name written in PE image. |
| 226 | |
| 227 | * Add --exclude-all-symbols option to PE based linkers. This prevents all |
| 228 | symbols from automatically being exported. |
| 229 | |
| 230 | * Add support for the Renesas RX processor. |
| 231 | |
| 232 | * Add support for alpha-vms target. |
| 233 | |
| 234 | Changes in 2.20: |
| 235 | |
| 236 | * GNU/Linux targets now support the STB_GNU_UNIQUE symbol binding. This is a |
| 237 | GNU extension to the standard set of ELF symbol bindings. The binding will |
| 238 | be passed on to the dynamic linker which will make sure that in the entire |
| 239 | process there is just one symbol with the given name and type in use. |
| 240 | |
| 241 | * PE targets now support a GNU extension to allow the alignment of common |
| 242 | common symbols to be specified. This support uses custom options in |
| 243 | the .drectve section, which will be disregarded by the native tools. |
| 244 | |
| 245 | * PE targets now add primitive support for ELF version scripts; symbols |
| 246 | are not versioned, but the local and global symbol visibility directives |
| 247 | are respected when filtering symbols in auto-export mode. |
| 248 | |
| 249 | * New option --no-export-dynamic to undo the effect of the -E and |
| 250 | --export-dynamic options. |
| 251 | |
| 252 | * ELF: --warn-alternate-em option to warn if an object has alternate |
| 253 | ELF machine code. |
| 254 | |
| 255 | * New script function REGION_ALIAS to add alias names to memory regions. |
| 256 | |
| 257 | * PE targets no longer make use of the long section names PE extension to |
| 258 | the COFF format when generating executable images, by default. The old |
| 259 | (slightly non-conformant) behaviour can still be invoked by using the |
| 260 | new '--enable-long-section-names' command-line option. It is also enabled |
| 261 | automatically in the presence of un-stripped debug information, as GDB |
| 262 | needs to be able to find the debug info sections by their full names. |
| 263 | |
| 264 | * For GNU/Linux systems the linker will now avoid processing any relocations |
| 265 | made against symbols of the STT_GNU_IFUNC type and instead emit them into |
| 266 | the resulting binary for processing by the loader. |
| 267 | |
| 268 | * --as-needed now links in a dynamic library if it satisfies undefined |
| 269 | symbols in regular objects, or in other dynamic libraries. In the |
| 270 | latter case the library is not linked if it is found in a DT_NEEDED |
| 271 | entry of one of the libraries already linked. |
| 272 | |
| 273 | * Add a new command-line option, -Ttext-segment ADDR, for ELF targets |
| 274 | to set the address of the first byte of the text segment. |
| 275 | |
| 276 | * Add support for Sunplus score architecture. |
| 277 | |
| 278 | * Add new option --use-nul-prefixed-import-tables to ld for PE targets to |
| 279 | allow fallback to old import table generation with null element prefix. |
| 280 | |
| 281 | * Windows PE systems now support a new --exclude-modules-for-implib option, |
| 282 | allowing users to partition object files and archive members between a DLL |
| 283 | and its associated import library as they are generated during linking. |
| 284 | |
| 285 | * Add support for Lattice Mico32 (lm32) architecture. |
| 286 | |
| 287 | * Add CR16 ELF --embedded-relocs (used to embedded relocations into binaries |
| 288 | for Embedded-PIC code) option. |
| 289 | |
| 290 | * Add to the PE/PE+ targets the support of two different kinds of |
| 291 | pseudo-relocations. They can be selected by the switches |
| 292 | --enable-runtime-pseudo-reloc-v1 and --enable-runtime-pseudo-reloc-v2. |
| 293 | For the switch --enable-runtime-pseudo-reloc it uses for 32-bit |
| 294 | runtime pseudo relocation version one, for 64-bit the version two. |
| 295 | |
| 296 | Changes in 2.19: |
| 297 | |
| 298 | * Linker scripts support a new INSERT command that makes it easier to |
| 299 | augment the default script. |
| 300 | |
| 301 | * Linker script input section filespecs may now specify a file within an |
| 302 | archive by writing "archive:file". |
| 303 | |
| 304 | * The --sort-common switch now has an optional argument which specifies the |
| 305 | direction of sorting. |
| 306 | |
| 307 | * The M68K linker now supports multiple GOT generation schemes controlled via |
| 308 | the --got=<type> command-line option. |
| 309 | |
| 310 | * The ARM EABI linker will now generate stubs for function calls to symbols |
| 311 | that are too far away. The placement of the stubs is controlled by a new |
| 312 | linker command-line option: --stub-group-size=N. |
| 313 | |
| 314 | Changes in 2.18: |
| 315 | |
| 316 | * Linker sources now released under version 3 of the GNU General Public |
| 317 | License. |
| 318 | |
| 319 | * ELF: New --build-id option to generate a unique per-binary identifier |
| 320 | embedded in a note section. |
| 321 | |
| 322 | * Added support for National Semicondutor CompactRISC (ie CR16) target. |
| 323 | |
| 324 | * -l:foo now searches the library path for a filename called foo, |
| 325 | without converting it to libfoo.a or libfoo.so. |
| 326 | |
| 327 | * Add a new command-line option '--default-script=FILE' or '-dT FILE' |
| 328 | which specifies a replacement for the built in, default linker |
| 329 | script. |
| 330 | |
| 331 | * ELF: Add -Bsymbolic-functions, --dynamic-list-cpp-new, which puts C++ |
| 332 | operator new and delete on the dynamic list, and --dynamic-list-data, |
| 333 | builtin list for --dynamic-list, which puts global data symbols on the |
| 334 | dynamic list. |
| 335 | |
| 336 | * Add support for x86_64 PE+ target. |
| 337 | |
| 338 | * Add support for Score target. |
| 339 | |
| 340 | * ELF: Add --dynamic-list option to specify a list of global symbols |
| 341 | whose references shouldn't be bound to the definition within the |
| 342 | shared library, or a list of symbols which should be added to the |
| 343 | symbol table in the executable. |
| 344 | |
| 345 | * The default output section LMA has changed for allocatable sections from |
| 346 | being equal to VMA, to keeping the difference between LMA and VMA the same as |
| 347 | the previous output section in the same region. This is a more useful |
| 348 | default when using overlays and other cases where you specify an LMA |
| 349 | differing from the VMA for some sections. |
| 350 | |
| 351 | * New switch: --print-gc-sections to list any sections removed by garabge |
| 352 | collection. |
| 353 | |
| 354 | * ARM: Added --vfp11-denorm-fix option to work around an erratum in current |
| 355 | VFP11 coprocessors. |
| 356 | |
| 357 | Changes in 2.17: |
| 358 | |
| 359 | * Support for the Infineon XC16X has been added by KPIT Cummins Infosystems. |
| 360 | |
| 361 | * Modify the Linux linker search order to better match ld.so search order. |
| 362 | Look for DT_NEEDED libraries in paths specified by ld.so.conf before |
| 363 | searching the default directories, rather than vice versa. |
| 364 | Use $prefix/etc/ld.so.conf if it exists, otherwise /etc/ld.so.conf. |
| 365 | |
| 366 | * PE-COFF: Forward exports from DLL's can now be specified in .def files |
| 367 | passed directly to ld. |
| 368 | |
| 369 | * Support for the Z80 processor family has been added. |
| 370 | |
| 371 | * Add support for the "@<file>" syntax to the command line, so that extra |
| 372 | switches can be read from <file>. |
| 373 | |
| 374 | Changes in 2.16: |
| 375 | |
| 376 | * Support for the R_ARM_V4BX relocation as defined in the ARM AAELF |
| 377 | specification has been added via the --fix-v4bx command-line option. |
| 378 | |
| 379 | * New linker script construct AS_NEEDED(), which sets the --as-needed flag |
| 380 | for input files listed inside of it. |
| 381 | |
| 382 | * A new command-line option, --sysroot, can be used to override the |
| 383 | default sysroot location. It only applies to toolchains that were |
| 384 | configured using --with-sysroot. |
| 385 | |
| 386 | * New linker script functions: ORIGIN() and LENGTH() which return information |
| 387 | about a specified memory region. |
| 388 | |
| 389 | * Port to MAXQ processor contributed by HCL Tech. |
| 390 | |
| 391 | * Added SEGMENT_START to the linker script language to permit the user to |
| 392 | override the base address for a segment from the command-line. |
| 393 | |
| 394 | * ELF: --warn-shared-textrel option to warn if adding a DT_TEXTREL to a shared |
| 395 | object. |
| 396 | |
| 397 | * Added SORT_BY_NAME and SORT_BY_ALIGNMENT to the linker script |
| 398 | language to permit sorting sections by section name or section |
| 399 | maximum alignment. |
| 400 | |
| 401 | * Added a new linker command-line switch, --sort-section name|alignment, |
| 402 | to sort sections by section name or maximum alignment. |
| 403 | |
| 404 | * ELF: --add-needed/--no-add-needed options to control if a DT_NEEDED tag |
| 405 | should be added when a shared library comes from DT_NEEDED tags. |
| 406 | |
| 407 | * Support for the crx-elf target added. |
| 408 | |
| 409 | * Support for the sh-symbianelf target added. |
| 410 | |
| 411 | * A new linker command-line switch has been added which allows the hash table |
| 412 | size to be set to a suitable prime value near to its argument. This switch |
| 413 | is --hash-size=<NUMBER>. Also if the switch --reduce-memory-overheads is |
| 414 | used, and --hash-size has not been used, then the default value will be set |
| 415 | to 1021. |
| 416 | |
| 417 | * Linker map files are now generated with an O(N) algorithm for finding symbols |
| 418 | that are defined in each section. This uses about 40% more memory for |
| 419 | symbols than the old O(N^2) algorithm. You can use the new |
| 420 | --reduce-memory-overheads option to select the old algorithm; this option |
| 421 | might also be used in the future to select similar tradeoffs. |
| 422 | |
| 423 | Changes in 2.15: |
| 424 | |
| 425 | * ELF: --as-needed/--no-as-needed options to control if a DT_NEEDED tag should |
| 426 | be added only when a shared library is referenced. |
| 427 | |
| 428 | * PE: --large-address-aware option to indicate executables support virtual |
| 429 | addresses greater than 2 gigabytes. |
| 430 | |
| 431 | * DWARF 2 support for i386pe added. |
| 432 | |
| 433 | * The linker script operator DEFINED() will now yield 1 only for a symbol that |
| 434 | is defined before the statement where DEFINED is used. |
| 435 | |
| 436 | * The MIPS --embedded-relocs (used to embed relocations into binaries for |
| 437 | Embedded-PIC code) is deprecated and will be removed in a future release. |
| 438 | |
| 439 | * cr16c support added by NSC. |
| 440 | |
| 441 | * m32r Linux (ELF) support added by Renesas. |
| 442 | |
| 443 | * Improved linker's handling of unresolved symbols. The switch |
| 444 | --unresolved-symbols=<method> has been added to tell the linker when it |
| 445 | should report them and the switch --warn-unresolved-symbols has been added to |
| 446 | make reports be issued as warning messages rather than errors. |
| 447 | |
| 448 | Changes in 2.14: |
| 449 | |
| 450 | * Added support for Xtensa architecture. |
| 451 | |
| 452 | * Added --with-sysroot configure switch to specify a target system root, for |
| 453 | linking against a target filesystem image. |
| 454 | |
| 455 | * Added --accept-unknown-linker-format to restore old linker behaviour (pre |
| 456 | 2.14) of silently accepting and linking in any files in an unknown binary |
| 457 | file format. |
| 458 | |
| 459 | * Added --no-omagic to undo the effects of the -N option. |
| 460 | |
| 461 | * Support for Texas Instruments TMS320C4x and TMS320C3x series of |
| 462 | DSP's contributed by Michael Hayes and Svein E. Seldal. |
| 463 | |
| 464 | * Added --with-lib-path configure switch to specify default value for |
| 465 | LIB_PATH. |
| 466 | |
| 467 | * ARM port to QNX operating system added by Graeme Peterson. |
| 468 | |
| 469 | * IP2K support added by Denis Chertykov. |
| 470 | |
| 471 | Changes in 2.13: |
| 472 | |
| 473 | * Support for the Fujitsu FRV architecture added by Red Hat. Models for FR400 |
| 474 | and FR500 included. |
| 475 | |
| 476 | Changes in version 2.13: |
| 477 | |
| 478 | * DEC VAX ELF support, by Matt Thomas. |
| 479 | |
| 480 | Changes in version 2.12: |
| 481 | |
| 482 | * Support for Don Knuth's MMIX, by Hans-Peter Nilsson. |
| 483 | |
| 484 | * Support for the OpenRISC 32-bit embedded processor by OpenCores. |
| 485 | |
| 486 | * Support for -z nocopyreloc in the x86 ELF linker, which disables |
| 487 | production of copy relocs. Warning: using this option may result in |
| 488 | non-sharable applications. |
| 489 | |
| 490 | * Support for -z combreloc in the ELF linker, which puts dynamic |
| 491 | relocations against the same symbol together, so that dynamic linker |
| 492 | can use an one-entry symbol lookup cache. |
| 493 | |
| 494 | * Support for ELF SHF_MERGE section merging, by Jakub Jelinek. |
| 495 | |
| 496 | Changes in version 2.11: |
| 497 | |
| 498 | * Support for AMD x86-64 architecture, by Jan Hubicka, SuSE Labs. |
| 499 | |
| 500 | * Support added for eliminating duplicate DWARF2 debug information by |
| 501 | having the compiler generate the information in sections called |
| 502 | .gnu.linkonce.wi.XXXX where XXXX is a checksum for the contents. The |
| 503 | linker then merges these sections together into the normal .debug_info |
| 504 | section. |
| 505 | |
| 506 | * The native ELF linker now searches the directories in DT_RUNPATH or |
| 507 | DT_RPATH of a shared library for shared libraries needed by it. |
| 508 | |
| 509 | * TI C54x support, by Timothy Wall. |
| 510 | |
| 511 | * Added command-line switch --section-start to set the start address of any |
| 512 | specified section. |
| 513 | |
| 514 | * Added ability to emit full relocation information in linked executables, |
| 515 | enabled by --emit-relocs. Some post-linkage optimization tools need |
| 516 | this information in order to be able to correctly identify and perform |
| 517 | symbol relative addressing in the event of changes in section contents |
| 518 | (instructions being added or deleted, extending data sections, etc.) |
| 519 | |
| 520 | * Support for i860, by Jason Eckhardt (preliminary, alpha quality). |
| 521 | |
| 522 | * Support for CRIS (Axis Communications ETRAX series). |
| 523 | |
| 524 | * Support for PDP-11 and 2.11BSD a.out format, by Lars Brinkhoff. |
| 525 | |
| 526 | Changes in version 2.10: |
| 527 | |
| 528 | * Added AT> to the linker script language to allow load-time allocation of |
| 529 | sections into regions. |
| 530 | |
| 531 | * Added garbage collection of unused sections, enabled by --gc-sections. |
| 532 | It does require a bit of backend support; currently implemented are |
| 533 | arm-elf, avr-elf, d10v-elf, fr30-elf, i386-elf, m32r-elf, m68k-elf, |
| 534 | mcore-elf, mips-elf, mn10300-elf, ppc-elf, sh-elf, sparc-elf, and v850-elf. |
| 535 | Others will ignore the option. |
| 536 | |
| 537 | * Added SORT to the linker script language to permit sorting sections by file |
| 538 | name or section name. |
| 539 | |
| 540 | * Added EXTERN to the linker script language as an equivalent to the -u |
| 541 | command-line option. |
| 542 | |
| 543 | * Added ASSERT to the linker script language. |
| 544 | |
| 545 | * Added EXCLUDE_FILE to the linker script language for further control over |
| 546 | wildcard file names. |
| 547 | |
| 548 | * Added -O option to optimize linker output (as of this writing, this only |
| 549 | affects ELF shared library generation). |
| 550 | |
| 551 | * The -e option now accepts a number as well as a symbol name. |
| 552 | |
| 553 | * Added --no-undefined option to disallow undefined symbols when creating a |
| 554 | shared library. |
| 555 | |
| 556 | * The linker now issues a warning, not an error, for an undefined symbol when |
| 557 | using -Bsymbolic; use the new --no-undefined option to get the old |
| 558 | behaviour. |
| 559 | |
| 560 | * Added --demangle and --no-demangle options. |
| 561 | |
| 562 | Changes in version 2.9: |
| 563 | |
| 564 | * Added SQUAD to the linker script language. |
| 565 | |
| 566 | * New option --no-warn-mismatch. |
| 567 | |
| 568 | * The MEMORY command now parses the attributes to determine where sections that |
| 569 | are not placed in a specific memory region are placed. |
| 570 | |
| 571 | Changes in version 2.8: |
| 572 | |
| 573 | * Linker scripts may now contain shell wildcard characters for file and section |
| 574 | names. |
| 575 | |
| 576 | * The linker now supports symbol versions in ELF. |
| 577 | |
| 578 | * The NOCROSSREFS command was added to the linker script language. |
| 579 | |
| 580 | * The LOADADDR expression was added to the linker script language. |
| 581 | |
| 582 | * MAX and MIN functions were added to the linker script language. |
| 583 | |
| 584 | * The OVERLAY construct was added to the linker script language. |
| 585 | |
| 586 | * New option --warn-section-align to warn when the address of an output section |
| 587 | changes due to alignment of an input section. |
| 588 | |
| 589 | * New options --filter/-F and --auxiliary/-f. |
| 590 | |
| 591 | Changes in version 2.7: |
| 592 | |
| 593 | * New option --cref to print out a cross reference table. |
| 594 | |
| 595 | * New option --wrap SYMBOL. |
| 596 | |
| 597 | * New option --no-whole-archive, to turn off the effect of --whole-archive. |
| 598 | |
| 599 | * Input sections assigned to the output section /DISCARD/ in the linker script |
| 600 | are not included in the output file. |
| 601 | |
| 602 | * The SunOS and ELF linkers now merge stabs debugging information which uses |
| 603 | the N_BINCL and N_EINCL stab types. This reduces the amount of debugging |
| 604 | information generated. |
| 605 | |
| 606 | Changes in version 2.6: |
| 607 | |
| 608 | * When an ELF section name is representable as a C identifier (this is not true |
| 609 | of most ELF section names), the linker will automatically define symbols |
| 610 | __start_SECNAME and __stop_SECNAME, where SECNAME is the section name, at the |
| 611 | beginning and the end of the section. This is used by glibc. |
| 612 | |
| 613 | Addendum: Current versions of the linker (at least for version 2.18 onwards |
| 614 | and possibly much earlier as well) place two restrictions on this feature: The |
| 615 | symbols are only implemented for orphaned sections, not for explicitly placed |
| 616 | sections and they are PROVIDEd rather than being defined. |
| 617 | |
| 618 | * When an ELF section named .gnu.warning is encountered in an input file, the |
| 619 | contents of the section are displayed as an error message, and the section is |
| 620 | not copied into the output file. This is used by glibc. |
| 621 | |
| 622 | * When an ELF section named .gnu.warning.SYMBOL is encountered in an input |
| 623 | file, and the symbol SYMBOL is referenced by some object file, the contents of |
| 624 | the section are displayed as an error message. The section is not copied into |
| 625 | the output file, unless doing a relocatable or shared link. This is used by |
| 626 | glibc. |
| 627 | |
| 628 | * New options -split-by-reloc and -split-by-file. |
| 629 | |
| 630 | * The linker now supports linking PIC compiled code on SPARC SunOS. It can |
| 631 | also create SPARC SunOS shared libraries, and, like the native SunOS linker, |
| 632 | will do so whenever there is an undefined symbol in the link and neither the -e |
| 633 | nor the -r option was used. |
| 634 | |
| 635 | * The -rpath option may be used on SunOS to set the list of directories to be |
| 636 | searched at run time. This overrides the default of building the list from the |
| 637 | -L options. |
| 638 | |
| 639 | * The COFF linker now combines debugging information for structs, unions, and |
| 640 | enums, so that even if the same type is defined in multiple input files it will |
| 641 | only be defined once in the output file. The --traditional-format switch will |
| 642 | prevent this optimization. |
| 643 | |
| 644 | Changes in version 2.5: |
| 645 | |
| 646 | * The linker now supports linking against SunOS shared libraries. It still can |
| 647 | not link SunOS PIC (Position Independent Code) files, so it can not be used to |
| 648 | generate shared libraries. |
| 649 | |
| 650 | * The linker now supports linking against ELF shared libraries for the i386 |
| 651 | (UnixWare) and SPARC (Solaris). It can also link ELF PIC files, and can be |
| 652 | used to generate shared libraries. Shared library generation is not well |
| 653 | tested; please report any problems encountered. The linker is now enabled for |
| 654 | Solaris again. |
| 655 | |
| 656 | * Eric Youngdale has contributed Linux support code, including linking against |
| 657 | Linux a.out shared libraries. The linker produces Linux QMAGIC binaries. |
| 658 | |
| 659 | * The ELF backend has been converted to the new linker code. To use the new |
| 660 | ELF linker, each particular target requires a relocation function. So far, |
| 661 | this function has been written for i386 (UnixWare), SPARC (Solaris) MIPS (Irix |
| 662 | 5), and HPPA ELF targets. |
| 663 | |
| 664 | * The -( (--start-group) and -) (--end-group) options have been added to |
| 665 | support searching a group of archives as though they were a single archive. |
| 666 | This can also be used in a linker script, as GROUP ( files ). |
| 667 | |
| 668 | * When a file is named on the command line, and the linker does not recognize |
| 669 | it as an object file, the linker will now treat the file as a linker script |
| 670 | file. A linker script named in this way augments, but does not replace, the |
| 671 | default linker script. |
| 672 | |
| 673 | * The -warn-once option was added. It causes the linker to only warn once per |
| 674 | undefined symbol, rather than once per reference. |
| 675 | |
| 676 | * The COFF backend has been converted to the new linker code. As with ELF, to |
| 677 | use the new linker, each particular target requires a relocation function. So |
| 678 | far, this function has been written for the i386, m68k, a29k and SH targets. |
| 679 | |
| 680 | * The -V flag was made a synonym for -v, for SVR4 compatibility. The old -V |
| 681 | behaviour is available via --verbose. |
| 682 | |
| 683 | Changes in version 2.4: |
| 684 | |
| 685 | * New linker code, by Steve Chamberlain and Ian Taylor. For a.out and ecoff |
| 686 | formats (so far), this should result in considerable savings in time |
| 687 | and memory used while linking; slightly poorer performance than |
| 688 | before for formats not converted yet. |
| 689 | |
| 690 | * Command-line parsing is no longer done with flex. This means |
| 691 | oddball characters in filenames won't get treated as argument |
| 692 | separators. |
| 693 | |
| 694 | * HP-PA ELF support, by Jeff Law. (No SOM support yet.) |
| 695 | |
| 696 | * Mach i386 support, by David Mackenzie. |
| 697 | |
| 698 | * Irix 4 shared libraries are now supported (Irix 5 uses ELF, and ELF shared |
| 699 | libraries are not yet supported). |
| 700 | |
| 701 | * COFF shared libraries (as on SCO) should work as well. |
| 702 | |
| 703 | * The linker is disabled for Solaris. (Actually, it was in 2.3 also, I just |
| 704 | forgot to note it.) Some of their C library routines don't work when |
| 705 | statically linked, and the GNU linker doesn't support dynamic linking yet. |
| 706 | |
| 707 | Changes in version 2.3: |
| 708 | |
| 709 | * Weak symbols are now supported. |
| 710 | |
| 711 | * ELF support has been added. The linker has been bootstrapped on |
| 712 | UnixWare and Solaris. |
| 713 | |
| 714 | * Alpha OSF/1 support has been added (non dynamic linking only). |
| 715 | |
| 716 | Changes in version 2.2: |
| 717 | |
| 718 | * The `bfd' library has been updated to reduce a.out-format string |
| 719 | table size. The effect of this is that files linked from many input |
| 720 | files with duplicate symbols (`-g' debugging records, or identical |
| 721 | static symbols) should be much smaller. |
| 722 | |
| 723 | Changes in version 2.1: |
| 724 | |
| 725 | * The ld -ySYMBOL flag (to trace references to SYMBOL) is now implemented. |
| 726 | |
| 727 | * There is now support for writing ECOFF files, so ld and the |
| 728 | other utilities should work on Risc/Ultrix and Irix. |
| 729 | |
| 730 | \f |
| 731 | Copyright (C) 2012-2018 Free Software Foundation, Inc. |
| 732 | |
| 733 | Copying and distribution of this file, with or without modification, |
| 734 | are permitted in any medium without royalty provided the copyright |
| 735 | notice and this notice are preserved. |
| 736 | |
| 737 | Local variables: |
| 738 | fill-column: 79 |
| 739 | End: |