3 * The MIPS --embedded-relocs (used to embed relocations into binaries for
4 Embedded-PIC code) is deprecated and will be removed in a future release.
6 * cr16c support added by NSC.
8 * m32r Linux (ELF) support added by Renesas.
10 * Improved linker's handling of unresolved symbols. The switch
11 --unresolved-symbols=<method> has been added to tell the linker when it
12 should report them and the switch --warn-unresolved-symbols has been added to
13 make reports be issued as warning messages rather than errors.
17 * Added support for Xtensa architecture.
19 * Added --with-sysroot configure switch to specify a target system root, for
20 linking against a target filesystem image.
22 * Added --accept-unknown-linker-format to restore old linker behaviour (pre
23 2.14) of silently accepting and linking in any files in an unknown binary
26 * Added --no-omagic to undo the effects of the -N option.
28 * Support for Texas Instruments TMS320C4x and TMS320C3x series of
29 DSP's contributed by Michael Hayes and Svein E. Seldal.
31 * Added --with-lib-path configure switch to specify default value for
34 * ARM port to QNX operating system added by Graeme Peterson.
36 * IP2K support added by Denis Chertykov.
40 * Support for the Fujitsu FRV architecture added by Red Hat. Models for FR400
43 Changes in version 2.13:
45 * DEC VAX ELF support, by Matt Thomas.
47 Changes in version 2.12:
49 * Support for Don Knuth's MMIX, by Hans-Peter Nilsson.
51 * Support for the OpenRISC 32-bit embedded processor by OpenCores.
53 * Support for -z nocopyreloc in the x86 ELF linker, which disables
54 production of copy relocs. Warning: using this option may result in
55 non-sharable applications.
57 * Support for -z combreloc in the ELF linker, which puts dynamic
58 relocations against the same symbol together, so that dynamic linker
59 can use an one-entry symbol lookup cache.
61 * Support for ELF SHF_MERGE section merging, by Jakub Jelinek.
63 Changes in version 2.11:
65 * Support for AMD x86-64 architecture, by Jan Hubicka, SuSE Labs.
67 * Support added for eliminating duplicate DWARF2 debug information by
68 having the compiler generate the information in sections called
69 .gnu.linkonce.wi.XXXX where XXXX is a checksum for the contents. The
70 linker then merges these sections together into the normal .debug_info
73 * The native ELF linker now searches the directories in DT_RUNPATH or
74 DT_RPATH of a shared library for shared libraries needed by it.
76 * TI C54x support, by Timothy Wall.
78 * Added command line switch --section-start to set the start address of any
81 * Added ability to emit full relocation information in linked executables,
82 enabled by --emit-relocs. Some post-linkage optimization tools need
83 this information in order to be able to correctly identify and perform
84 symbol relative addressing in the event of changes in section contents
85 (instructions being added or deleted, extending data sections, etc.)
87 * Support for i860, by Jason Eckhardt (preliminary, alpha quality).
89 * Support for CRIS (Axis Communications ETRAX series).
91 * Support for PDP-11 and 2.11BSD a.out format, by Lars Brinkhoff.
93 Changes in version 2.10:
95 * Added AT> to the linker script language to allow load-time allocation of
96 sections into regions.
98 * Added garbage collection of unused sections, enabled by --gc-sections.
99 It does require a bit of backend support; currently implemented are
100 arm-elf, avr-elf, d10v-elf, fr30-elf, i386-elf, m32r-elf, m68k-elf,
101 mcore-elf, mips-elf, mn10300-elf, ppc-elf, sh-elf, sparc-elf, and v850-elf.
102 Others will ignore the option.
104 * Added SORT to the linker script language to permit sorting sections by file
105 name or section name.
107 * Added EXTERN to the linker script language as an equivalent to the -u
110 * Added ASSERT to the linker script language.
112 * Added EXCLUDE_FILE to the linker script language for further control over
115 * Added -O option to optimize linker output (as of this writing, this only
116 affects ELF shared library generation).
118 * The -e option now accepts a number as well as a symbol name.
120 * Added --no-undefined option to disallow undefined symbols when creating a
123 * The linker now issues a warning, not an error, for an undefined symbol when
124 using -Bsymbolic; use the new --no-undefined option to get the old
127 * Added --demangle and --no-demangle options.
129 Changes in version 2.9:
131 * Added SQUAD to the linker script language.
133 * New option --no-warn-mismatch.
135 * The MEMORY command now parses the attributes to determine where sections that
136 are not placed in a specific memory region are placed.
138 Changes in version 2.8:
140 * Linker scripts may now contain shell wildcard characters for file and section
143 * The linker now supports symbol versions in ELF.
145 * The NOCROSSREFS command was added to the linker script language.
147 * The LOADADDR expression was added to the linker script language.
149 * MAX and MIN functions were added to the linker script language.
151 * The OVERLAY construct was added to the linker script language.
153 * New option --warn-section-align to warn when the address of an output section
154 changes due to alignment of an input section.
156 * New options --filter/-F and --auxiliary/-f.
158 Changes in version 2.7:
160 * New option --cref to print out a cross reference table.
162 * New option --wrap SYMBOL.
164 * New option --no-whole-archive, to turn off the effect of --whole-archive.
166 * Input sections assigned to the output section /DISCARD/ in the linker script
167 are not included in the output file.
169 * The SunOS and ELF linkers now merge stabs debugging information which uses
170 the N_BINCL and N_EINCL stab types. This reduces the amount of debugging
171 information generated.
173 Changes in version 2.6:
175 * When an ELF section name is representable as a C identifier (this is not true
176 of most ELF section names), the linker will automatically define symbols
177 __start_SECNAME and __stop_SECNAME, where SECNAME is the section name, at the
178 beginning and the end of the section. This is used by glibc.
180 * When an ELF section named .gnu.warning is encountered in an input file, the
181 contents of the section are displayed as an error message, and the section is
182 not copied into the output file. This is used by glibc.
184 * When an ELF section named .gnu.warning.SYMBOL is encountered in an input
185 file, and the symbol SYMBOL is referenced by some object file, the contents of
186 the section are displayed as an error message. The section is not copied into
187 the output file, unless doing a relocatable or shared link. This is used by
190 * New options -split-by-reloc and -split-by-file.
192 * The linker now supports linking PIC compiled code on SPARC SunOS. It can
193 also create SPARC SunOS shared libraries, and, like the native SunOS linker,
194 will do so whenever there is an undefined symbol in the link and neither the -e
195 nor the -r option was used.
197 * The -rpath option may be used on SunOS to set the list of directories to be
198 searched at run time. This overrides the default of building the list from the
201 * The COFF linker now combines debugging information for structs, unions, and
202 enums, so that even if the same type is defined in multiple input files it will
203 only be defined once in the output file. The --traditional-format switch will
204 prevent this optimization.
206 Changes in version 2.5:
208 * The linker now supports linking against SunOS shared libraries. It still can
209 not link SunOS PIC (Position Independent Code) files, so it can not be used to
210 generate shared libraries.
212 * The linker now supports linking against ELF shared libraries for the i386
213 (UnixWare) and SPARC (Solaris). It can also link ELF PIC files, and can be
214 used to generate shared libraries. Shared library generation is not well
215 tested; please report any problems encountered. The linker is now enabled for
218 * Eric Youngdale has contributed Linux support code, including linking against
219 Linux a.out shared libraries. The linker produces Linux QMAGIC binaries.
221 * The ELF backend has been converted to the new linker code. To use the new
222 ELF linker, each particular target requires a relocation function. So far,
223 this function has been written for i386 (UnixWare), SPARC (Solaris) MIPS (Irix
224 5), and HPPA ELF targets.
226 * The -( (--start-group) and -) (--end-group) options have been added to
227 support searching a group of archives as though they were a single archive.
228 This can also be used in a linker script, as GROUP ( files ).
230 * When a file is named on the command line, and the linker does not recognize
231 it as an object file, the linker will now treat the file as a linker script
232 file. A linker script named in this way augments, but does not replace, the
233 default linker script.
235 * The -warn-once option was added. It causes the linker to only warn once per
236 undefined symbol, rather than once per reference.
238 * The COFF backend has been converted to the new linker code. As with ELF, to
239 use the new linker, each particular target requires a relocation function. So
240 far, this function has been written for the i386, m68k, a29k and SH targets.
242 * The -V flag was made a synonym for -v, for SVR4 compatibility. The old -V
243 behaviour is available via --verbose.
245 Changes in version 2.4:
247 * New linker code, by Steve Chamberlain and Ian Taylor. For a.out and ecoff
248 formats (so far), this should result in considerable savings in time
249 and memory used while linking; slightly poorer performance than
250 before for formats not converted yet.
252 * Command-line parsing is no longer done with flex. This means
253 oddball characters in filenames won't get treated as argument
256 * HP-PA ELF support, by Jeff Law. (No SOM support yet.)
258 * Mach i386 support, by David Mackenzie.
260 * Irix 4 shared libraries are now supported (Irix 5 uses ELF, and ELF shared
261 libraries are not yet supported).
263 * COFF shared libraries (as on SCO) should work as well.
265 * The linker is disabled for Solaris. (Actually, it was in 2.3 also, I just
266 forgot to note it.) Some of their C library routines don't work when
267 statically linked, and the GNU linker doesn't support dynamic linking yet.
269 Changes in version 2.3:
271 * Weak symbols are now supported.
273 * ELF support has been added. The linker has been bootstrapped on
274 UnixWare and Solaris.
276 * Alpha OSF/1 support has been added (non dynamic linking only).
278 Changes in version 2.2:
280 * The `bfd' library has been updated to reduce a.out-format string
281 table size. The effect of this is that files linked from many input
282 files with duplicate symbols (`-g' debugging records, or identical
283 static symbols) should be much smaller.
285 Changes in version 2.1:
287 * The ld -ySYMBOL flag (to trace references to SYMBOL) is now implemented.
289 * There is now support for writing ECOFF files, so ld and the
290 other utilities should work on Risc/Ultrix and Irix.