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