3 * New PE --large-address-aware option to indicate executables support virtual
4 addresses greater than 2 gigabytes.
6 * DWARF 2 support for i386pe added.
8 * The linker script operator DEFINED() will now yield 1 only for a symbol that
9 is defined before the statement where DEFINED is used.
11 * The MIPS --embedded-relocs (used to embed relocations into binaries for
12 Embedded-PIC code) is deprecated and will be removed in a future release.
14 * cr16c support added by NSC.
16 * m32r Linux (ELF) support added by Renesas.
18 * Improved linker's handling of unresolved symbols. The switch
19 --unresolved-symbols=<method> has been added to tell the linker when it
20 should report them and the switch --warn-unresolved-symbols has been added to
21 make reports be issued as warning messages rather than errors.
25 * Added support for Xtensa architecture.
27 * Added --with-sysroot configure switch to specify a target system root, for
28 linking against a target filesystem image.
30 * Added --accept-unknown-linker-format to restore old linker behaviour (pre
31 2.14) of silently accepting and linking in any files in an unknown binary
34 * Added --no-omagic to undo the effects of the -N option.
36 * Support for Texas Instruments TMS320C4x and TMS320C3x series of
37 DSP's contributed by Michael Hayes and Svein E. Seldal.
39 * Added --with-lib-path configure switch to specify default value for
42 * ARM port to QNX operating system added by Graeme Peterson.
44 * IP2K support added by Denis Chertykov.
48 * Support for the Fujitsu FRV architecture added by Red Hat. Models for FR400
51 Changes in version 2.13:
53 * DEC VAX ELF support, by Matt Thomas.
55 Changes in version 2.12:
57 * Support for Don Knuth's MMIX, by Hans-Peter Nilsson.
59 * Support for the OpenRISC 32-bit embedded processor by OpenCores.
61 * Support for -z nocopyreloc in the x86 ELF linker, which disables
62 production of copy relocs. Warning: using this option may result in
63 non-sharable applications.
65 * Support for -z combreloc in the ELF linker, which puts dynamic
66 relocations against the same symbol together, so that dynamic linker
67 can use an one-entry symbol lookup cache.
69 * Support for ELF SHF_MERGE section merging, by Jakub Jelinek.
71 Changes in version 2.11:
73 * Support for AMD x86-64 architecture, by Jan Hubicka, SuSE Labs.
75 * Support added for eliminating duplicate DWARF2 debug information by
76 having the compiler generate the information in sections called
77 .gnu.linkonce.wi.XXXX where XXXX is a checksum for the contents. The
78 linker then merges these sections together into the normal .debug_info
81 * The native ELF linker now searches the directories in DT_RUNPATH or
82 DT_RPATH of a shared library for shared libraries needed by it.
84 * TI C54x support, by Timothy Wall.
86 * Added command line switch --section-start to set the start address of any
89 * Added ability to emit full relocation information in linked executables,
90 enabled by --emit-relocs. Some post-linkage optimization tools need
91 this information in order to be able to correctly identify and perform
92 symbol relative addressing in the event of changes in section contents
93 (instructions being added or deleted, extending data sections, etc.)
95 * Support for i860, by Jason Eckhardt (preliminary, alpha quality).
97 * Support for CRIS (Axis Communications ETRAX series).
99 * Support for PDP-11 and 2.11BSD a.out format, by Lars Brinkhoff.
101 Changes in version 2.10:
103 * Added AT> to the linker script language to allow load-time allocation of
104 sections into regions.
106 * Added garbage collection of unused sections, enabled by --gc-sections.
107 It does require a bit of backend support; currently implemented are
108 arm-elf, avr-elf, d10v-elf, fr30-elf, i386-elf, m32r-elf, m68k-elf,
109 mcore-elf, mips-elf, mn10300-elf, ppc-elf, sh-elf, sparc-elf, and v850-elf.
110 Others will ignore the option.
112 * Added SORT to the linker script language to permit sorting sections by file
113 name or section name.
115 * Added EXTERN to the linker script language as an equivalent to the -u
118 * Added ASSERT to the linker script language.
120 * Added EXCLUDE_FILE to the linker script language for further control over
123 * Added -O option to optimize linker output (as of this writing, this only
124 affects ELF shared library generation).
126 * The -e option now accepts a number as well as a symbol name.
128 * Added --no-undefined option to disallow undefined symbols when creating a
131 * The linker now issues a warning, not an error, for an undefined symbol when
132 using -Bsymbolic; use the new --no-undefined option to get the old
135 * Added --demangle and --no-demangle options.
137 Changes in version 2.9:
139 * Added SQUAD to the linker script language.
141 * New option --no-warn-mismatch.
143 * The MEMORY command now parses the attributes to determine where sections that
144 are not placed in a specific memory region are placed.
146 Changes in version 2.8:
148 * Linker scripts may now contain shell wildcard characters for file and section
151 * The linker now supports symbol versions in ELF.
153 * The NOCROSSREFS command was added to the linker script language.
155 * The LOADADDR expression was added to the linker script language.
157 * MAX and MIN functions were added to the linker script language.
159 * The OVERLAY construct was added to the linker script language.
161 * New option --warn-section-align to warn when the address of an output section
162 changes due to alignment of an input section.
164 * New options --filter/-F and --auxiliary/-f.
166 Changes in version 2.7:
168 * New option --cref to print out a cross reference table.
170 * New option --wrap SYMBOL.
172 * New option --no-whole-archive, to turn off the effect of --whole-archive.
174 * Input sections assigned to the output section /DISCARD/ in the linker script
175 are not included in the output file.
177 * The SunOS and ELF linkers now merge stabs debugging information which uses
178 the N_BINCL and N_EINCL stab types. This reduces the amount of debugging
179 information generated.
181 Changes in version 2.6:
183 * When an ELF section name is representable as a C identifier (this is not true
184 of most ELF section names), the linker will automatically define symbols
185 __start_SECNAME and __stop_SECNAME, where SECNAME is the section name, at the
186 beginning and the end of the section. This is used by glibc.
188 * When an ELF section named .gnu.warning is encountered in an input file, the
189 contents of the section are displayed as an error message, and the section is
190 not copied into the output file. This is used by glibc.
192 * When an ELF section named .gnu.warning.SYMBOL is encountered in an input
193 file, and the symbol SYMBOL is referenced by some object file, the contents of
194 the section are displayed as an error message. The section is not copied into
195 the output file, unless doing a relocatable or shared link. This is used by
198 * New options -split-by-reloc and -split-by-file.
200 * The linker now supports linking PIC compiled code on SPARC SunOS. It can
201 also create SPARC SunOS shared libraries, and, like the native SunOS linker,
202 will do so whenever there is an undefined symbol in the link and neither the -e
203 nor the -r option was used.
205 * The -rpath option may be used on SunOS to set the list of directories to be
206 searched at run time. This overrides the default of building the list from the
209 * The COFF linker now combines debugging information for structs, unions, and
210 enums, so that even if the same type is defined in multiple input files it will
211 only be defined once in the output file. The --traditional-format switch will
212 prevent this optimization.
214 Changes in version 2.5:
216 * The linker now supports linking against SunOS shared libraries. It still can
217 not link SunOS PIC (Position Independent Code) files, so it can not be used to
218 generate shared libraries.
220 * The linker now supports linking against ELF shared libraries for the i386
221 (UnixWare) and SPARC (Solaris). It can also link ELF PIC files, and can be
222 used to generate shared libraries. Shared library generation is not well
223 tested; please report any problems encountered. The linker is now enabled for
226 * Eric Youngdale has contributed Linux support code, including linking against
227 Linux a.out shared libraries. The linker produces Linux QMAGIC binaries.
229 * The ELF backend has been converted to the new linker code. To use the new
230 ELF linker, each particular target requires a relocation function. So far,
231 this function has been written for i386 (UnixWare), SPARC (Solaris) MIPS (Irix
232 5), and HPPA ELF targets.
234 * The -( (--start-group) and -) (--end-group) options have been added to
235 support searching a group of archives as though they were a single archive.
236 This can also be used in a linker script, as GROUP ( files ).
238 * When a file is named on the command line, and the linker does not recognize
239 it as an object file, the linker will now treat the file as a linker script
240 file. A linker script named in this way augments, but does not replace, the
241 default linker script.
243 * The -warn-once option was added. It causes the linker to only warn once per
244 undefined symbol, rather than once per reference.
246 * The COFF backend has been converted to the new linker code. As with ELF, to
247 use the new linker, each particular target requires a relocation function. So
248 far, this function has been written for the i386, m68k, a29k and SH targets.
250 * The -V flag was made a synonym for -v, for SVR4 compatibility. The old -V
251 behaviour is available via --verbose.
253 Changes in version 2.4:
255 * New linker code, by Steve Chamberlain and Ian Taylor. For a.out and ecoff
256 formats (so far), this should result in considerable savings in time
257 and memory used while linking; slightly poorer performance than
258 before for formats not converted yet.
260 * Command-line parsing is no longer done with flex. This means
261 oddball characters in filenames won't get treated as argument
264 * HP-PA ELF support, by Jeff Law. (No SOM support yet.)
266 * Mach i386 support, by David Mackenzie.
268 * Irix 4 shared libraries are now supported (Irix 5 uses ELF, and ELF shared
269 libraries are not yet supported).
271 * COFF shared libraries (as on SCO) should work as well.
273 * The linker is disabled for Solaris. (Actually, it was in 2.3 also, I just
274 forgot to note it.) Some of their C library routines don't work when
275 statically linked, and the GNU linker doesn't support dynamic linking yet.
277 Changes in version 2.3:
279 * Weak symbols are now supported.
281 * ELF support has been added. The linker has been bootstrapped on
282 UnixWare and Solaris.
284 * Alpha OSF/1 support has been added (non dynamic linking only).
286 Changes in version 2.2:
288 * The `bfd' library has been updated to reduce a.out-format string
289 table size. The effect of this is that files linked from many input
290 files with duplicate symbols (`-g' debugging records, or identical
291 static symbols) should be much smaller.
293 Changes in version 2.1:
295 * The ld -ySYMBOL flag (to trace references to SYMBOL) is now implemented.
297 * There is now support for writing ECOFF files, so ld and the
298 other utilities should work on Risc/Ultrix and Irix.