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