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