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1 -*- text -*-
2
3 * Added SORT_BY_NAME and SORT_BY_ALIGNMENT to the linker script
4 language to permit sorting sections by section name or section
5 maximum alignment.
6
7 * Added a new linker command line switch, --sort-section name|alignment,
8 to sort sections by section name or maximum alignment.
9
10 * New ELF --add-needed/--no-add-needed options to control if a
11 DT_NEEDED tag should be added when a shared library comes from
12 DT_NEEDED tags.
13
14 * Support for the crx-elf target added.
15
16 * Support for the sh-symbianelf target added.
17
18 * A new linker command line switch has been added which allows the hash table
19 size to be set to a suitable prime value near to its argument. This switch
20 is --hash-size=<NUMBER>. Also if the switch --reduce-memory-overheads is
21 used, and --hash-size has not been used, then the default value will be set
22 to 1021.
23
24 * Linker map files are now generated with an O(N) algorithm for finding symbols
25 that are defined in each section. This uses about 40% more memory for
26 symbols than the old O(N^2) algorithm. You can use the new
27 --reduce-memory-overheads option to select the old algorithm; this option
28 might also be used in the future to select similar tradeoffs.
29
30 Changes in 2.15:
31
32 * New ELF --as-needed/--no-as-needed options to control if a DT_NEEDED
33 tag should be added only when a shared library is referenced.
34
35 * New PE --large-address-aware option to indicate executables support virtual
36 addresses greater than 2 gigabytes.
37
38 * DWARF 2 support for i386pe added.
39
40 * The linker script operator DEFINED() will now yield 1 only for a symbol that
41 is defined before the statement where DEFINED is used.
42
43 * The MIPS --embedded-relocs (used to embed relocations into binaries for
44 Embedded-PIC code) is deprecated and will be removed in a future release.
45
46 * cr16c support added by NSC.
47
48 * m32r Linux (ELF) support added by Renesas.
49
50 * Improved linker's handling of unresolved symbols. The switch
51 --unresolved-symbols=<method> has been added to tell the linker when it
52 should report them and the switch --warn-unresolved-symbols has been added to
53 make reports be issued as warning messages rather than errors.
54
55 Changes in 2.14:
56
57 * Added support for Xtensa architecture.
58
59 * Added --with-sysroot configure switch to specify a target system root, for
60 linking against a target filesystem image.
61
62 * Added --accept-unknown-linker-format to restore old linker behaviour (pre
63 2.14) of silently accepting and linking in any files in an unknown binary
64 file format.
65
66 * Added --no-omagic to undo the effects of the -N option.
67
68 * Support for Texas Instruments TMS320C4x and TMS320C3x series of
69 DSP's contributed by Michael Hayes and Svein E. Seldal.
70
71 * Added --with-lib-path configure switch to specify default value for
72 LIB_PATH.
73
74 * ARM port to QNX operating system added by Graeme Peterson.
75
76 * IP2K support added by Denis Chertykov.
77
78 Changes in 2.13:
79
80 * Support for the Fujitsu FRV architecture added by Red Hat. Models for FR400
81 and FR500 included.
82
83 Changes in version 2.13:
84
85 * DEC VAX ELF support, by Matt Thomas.
86
87 Changes in version 2.12:
88
89 * Support for Don Knuth's MMIX, by Hans-Peter Nilsson.
90
91 * Support for the OpenRISC 32-bit embedded processor by OpenCores.
92
93 * Support for -z nocopyreloc in the x86 ELF linker, which disables
94 production of copy relocs. Warning: using this option may result in
95 non-sharable applications.
96
97 * Support for -z combreloc in the ELF linker, which puts dynamic
98 relocations against the same symbol together, so that dynamic linker
99 can use an one-entry symbol lookup cache.
100
101 * Support for ELF SHF_MERGE section merging, by Jakub Jelinek.
102
103 Changes in version 2.11:
104
105 * Support for AMD x86-64 architecture, by Jan Hubicka, SuSE Labs.
106
107 * Support added for eliminating duplicate DWARF2 debug information by
108 having the compiler generate the information in sections called
109 .gnu.linkonce.wi.XXXX where XXXX is a checksum for the contents. The
110 linker then merges these sections together into the normal .debug_info
111 section.
112
113 * The native ELF linker now searches the directories in DT_RUNPATH or
114 DT_RPATH of a shared library for shared libraries needed by it.
115
116 * TI C54x support, by Timothy Wall.
117
118 * Added command line switch --section-start to set the start address of any
119 specified section.
120
121 * Added ability to emit full relocation information in linked executables,
122 enabled by --emit-relocs. Some post-linkage optimization tools need
123 this information in order to be able to correctly identify and perform
124 symbol relative addressing in the event of changes in section contents
125 (instructions being added or deleted, extending data sections, etc.)
126
127 * Support for i860, by Jason Eckhardt (preliminary, alpha quality).
128
129 * Support for CRIS (Axis Communications ETRAX series).
130
131 * Support for PDP-11 and 2.11BSD a.out format, by Lars Brinkhoff.
132
133 Changes in version 2.10:
134
135 * Added AT> to the linker script language to allow load-time allocation of
136 sections into regions.
137
138 * Added garbage collection of unused sections, enabled by --gc-sections.
139 It does require a bit of backend support; currently implemented are
140 arm-elf, avr-elf, d10v-elf, fr30-elf, i386-elf, m32r-elf, m68k-elf,
141 mcore-elf, mips-elf, mn10300-elf, ppc-elf, sh-elf, sparc-elf, and v850-elf.
142 Others will ignore the option.
143
144 * Added SORT to the linker script language to permit sorting sections by file
145 name or section name.
146
147 * Added EXTERN to the linker script language as an equivalent to the -u
148 command-line option.
149
150 * Added ASSERT to the linker script language.
151
152 * Added EXCLUDE_FILE to the linker script language for further control over
153 wildcard file names.
154
155 * Added -O option to optimize linker output (as of this writing, this only
156 affects ELF shared library generation).
157
158 * The -e option now accepts a number as well as a symbol name.
159
160 * Added --no-undefined option to disallow undefined symbols when creating a
161 shared library.
162
163 * The linker now issues a warning, not an error, for an undefined symbol when
164 using -Bsymbolic; use the new --no-undefined option to get the old
165 behaviour.
166
167 * Added --demangle and --no-demangle options.
168
169 Changes in version 2.9:
170
171 * Added SQUAD to the linker script language.
172
173 * New option --no-warn-mismatch.
174
175 * The MEMORY command now parses the attributes to determine where sections that
176 are not placed in a specific memory region are placed.
177
178 Changes in version 2.8:
179
180 * Linker scripts may now contain shell wildcard characters for file and section
181 names.
182
183 * The linker now supports symbol versions in ELF.
184
185 * The NOCROSSREFS command was added to the linker script language.
186
187 * The LOADADDR expression was added to the linker script language.
188
189 * MAX and MIN functions were added to the linker script language.
190
191 * The OVERLAY construct was added to the linker script language.
192
193 * New option --warn-section-align to warn when the address of an output section
194 changes due to alignment of an input section.
195
196 * New options --filter/-F and --auxiliary/-f.
197
198 Changes in version 2.7:
199
200 * New option --cref to print out a cross reference table.
201
202 * New option --wrap SYMBOL.
203
204 * New option --no-whole-archive, to turn off the effect of --whole-archive.
205
206 * Input sections assigned to the output section /DISCARD/ in the linker script
207 are not included in the output file.
208
209 * The SunOS and ELF linkers now merge stabs debugging information which uses
210 the N_BINCL and N_EINCL stab types. This reduces the amount of debugging
211 information generated.
212
213 Changes in version 2.6:
214
215 * When an ELF section name is representable as a C identifier (this is not true
216 of most ELF section names), the linker will automatically define symbols
217 __start_SECNAME and __stop_SECNAME, where SECNAME is the section name, at the
218 beginning and the end of the section. This is used by glibc.
219
220 * When an ELF section named .gnu.warning is encountered in an input file, the
221 contents of the section are displayed as an error message, and the section is
222 not copied into the output file. This is used by glibc.
223
224 * When an ELF section named .gnu.warning.SYMBOL is encountered in an input
225 file, and the symbol SYMBOL is referenced by some object file, the contents of
226 the section are displayed as an error message. The section is not copied into
227 the output file, unless doing a relocatable or shared link. This is used by
228 glibc.
229
230 * New options -split-by-reloc and -split-by-file.
231
232 * The linker now supports linking PIC compiled code on SPARC SunOS. It can
233 also create SPARC SunOS shared libraries, and, like the native SunOS linker,
234 will do so whenever there is an undefined symbol in the link and neither the -e
235 nor the -r option was used.
236
237 * The -rpath option may be used on SunOS to set the list of directories to be
238 searched at run time. This overrides the default of building the list from the
239 -L options.
240
241 * The COFF linker now combines debugging information for structs, unions, and
242 enums, so that even if the same type is defined in multiple input files it will
243 only be defined once in the output file. The --traditional-format switch will
244 prevent this optimization.
245
246 Changes in version 2.5:
247
248 * The linker now supports linking against SunOS shared libraries. It still can
249 not link SunOS PIC (Position Independent Code) files, so it can not be used to
250 generate shared libraries.
251
252 * The linker now supports linking against ELF shared libraries for the i386
253 (UnixWare) and SPARC (Solaris). It can also link ELF PIC files, and can be
254 used to generate shared libraries. Shared library generation is not well
255 tested; please report any problems encountered. The linker is now enabled for
256 Solaris again.
257
258 * Eric Youngdale has contributed Linux support code, including linking against
259 Linux a.out shared libraries. The linker produces Linux QMAGIC binaries.
260
261 * The ELF backend has been converted to the new linker code. To use the new
262 ELF linker, each particular target requires a relocation function. So far,
263 this function has been written for i386 (UnixWare), SPARC (Solaris) MIPS (Irix
264 5), and HPPA ELF targets.
265
266 * The -( (--start-group) and -) (--end-group) options have been added to
267 support searching a group of archives as though they were a single archive.
268 This can also be used in a linker script, as GROUP ( files ).
269
270 * When a file is named on the command line, and the linker does not recognize
271 it as an object file, the linker will now treat the file as a linker script
272 file. A linker script named in this way augments, but does not replace, the
273 default linker script.
274
275 * The -warn-once option was added. It causes the linker to only warn once per
276 undefined symbol, rather than once per reference.
277
278 * The COFF backend has been converted to the new linker code. As with ELF, to
279 use the new linker, each particular target requires a relocation function. So
280 far, this function has been written for the i386, m68k, a29k and SH targets.
281
282 * The -V flag was made a synonym for -v, for SVR4 compatibility. The old -V
283 behaviour is available via --verbose.
284
285 Changes in version 2.4:
286
287 * New linker code, by Steve Chamberlain and Ian Taylor. For a.out and ecoff
288 formats (so far), this should result in considerable savings in time
289 and memory used while linking; slightly poorer performance than
290 before for formats not converted yet.
291
292 * Command-line parsing is no longer done with flex. This means
293 oddball characters in filenames won't get treated as argument
294 separators.
295
296 * HP-PA ELF support, by Jeff Law. (No SOM support yet.)
297
298 * Mach i386 support, by David Mackenzie.
299
300 * Irix 4 shared libraries are now supported (Irix 5 uses ELF, and ELF shared
301 libraries are not yet supported).
302
303 * COFF shared libraries (as on SCO) should work as well.
304
305 * The linker is disabled for Solaris. (Actually, it was in 2.3 also, I just
306 forgot to note it.) Some of their C library routines don't work when
307 statically linked, and the GNU linker doesn't support dynamic linking yet.
308
309 Changes in version 2.3:
310
311 * Weak symbols are now supported.
312
313 * ELF support has been added. The linker has been bootstrapped on
314 UnixWare and Solaris.
315
316 * Alpha OSF/1 support has been added (non dynamic linking only).
317
318 Changes in version 2.2:
319
320 * The `bfd' library has been updated to reduce a.out-format string
321 table size. The effect of this is that files linked from many input
322 files with duplicate symbols (`-g' debugging records, or identical
323 static symbols) should be much smaller.
324
325 Changes in version 2.1:
326
327 * The ld -ySYMBOL flag (to trace references to SYMBOL) is now implemented.
328
329 * There is now support for writing ECOFF files, so ld and the
330 other utilities should work on Risc/Ultrix and Irix.
331
332 \f
333 Local variables:
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335 End: