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x86: Properly set IBT and SHSTK properties for -z ibt/shstk
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252b5132 1-*- text -*-
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3Changes in 2.32:
4
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5* Report property change in linker map file when merging GNU properties.
6
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7* Add support for the C-SKY processor series.
8
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9* -t now doesn't report members within archives, unless -t is given twice.
10 A single -t is now more useful when generating a list of files that should be
11 packaged for a linker bug report. For example:
12 gcc hello.c -save-temps -Wl,-t | xargs realpath | sort | uniq > files
13 tar cJf test.tar.xz `cat files`
14
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15Changes in 2.31:
16
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17* Speed up direct linking with DLLs for Cygwin and Mingw targets.
18
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19* Add a configure option --enable-separate-code to decide whether
20 -z separate-code should be enabled in ELF linker by default. Default
21 to yes for Linux/x86 targets. Note that -z separate-code can increase
22 disk and memory size.
23
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24Changes in 2.30:
25
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26* Add -z separate-code to generate separate code PT_LOAD segment.
27
a05a5b64 28* Add "-z undefs" command-line option as the inverse of the "-z defs" option.
97a232d7 29
a05a5b64 30* Add -z globalaudit command-line option to force audit libraries to be run
93ab9c0d 31 for every dynamic object loaded by an executable - provided that the loader
6c19b93b 32 supports this functionality.
7feec526 33
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34* Tighten linker script grammar around file name specifiers to prevent the use
35 of SORT_BY_ALIGNMENT and SORT_BY_INIT_PRIORITY on filenames. These would
36 previously be accepted but had no effect.
37
38* The EXCLUDE_FILE directive can now be placed within any SORT_* directive
39 within input section lists.
40
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41Changes in 2.29:
42
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43* Support for -z shstk in the x86 ELF linker to generate
44 GNU_PROPERTY_X86_FEATURE_1_SHSTK in ELF GNU program properties.
45
46* Add support for GNU_PROPERTY_X86_FEATURE_1_SHSTK in ELF GNU program
47 properties in the x86 ELF linker.
48
ee2fdd6f 49* Add support for GNU_PROPERTY_X86_FEATURE_1_IBT in ELF GNU program
48580982 50 properties in the x86 ELF linker.
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51
52* Support for -z ibtplt in the x86 ELF linker to generate IBT-enabled
53 PLT.
54
55* Support for -z ibt in the x86 ELF linker to generate IBT-enabled
56 PLT as well as GNU_PROPERTY_X86_FEATURE_1_IBT in ELF GNU program
57 properties.
58
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59* Add support for ELF SHF_GNU_MBIND and PT_GNU_MBIND_XXX.
60
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61* Add support for ELF GNU program properties.
62
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63* Add support for the Texas Instruments PRU processor.
64
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65* When configuring for arc*-*-linux* targets the default linker emulation will
66 change if --with-cpu=nps400 is used at configure time.
67
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68* Improve assignment of LMAs to orphan sections in some edge cases where a
69 mixture of both AT>LMA_REGION and AT(LMA) are used.
70
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71* Orphan sections placed after an empty section that has an AT(LMA) will now
72 take an load memory address starting from LMA.
73
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74* Section groups can now be resolved (the group deleted and the group members
75 placed like normal sections) at partial link time either using the new linker
76 option --force-group-allocation or by placing FORCE_GROUP_ALLOCATION into the
77 linker script.
78
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79Changes in 2.28:
80
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81* The EXCLUDE_FILE linker script construct can now be applied outside of the
82 section list in order for the exclusions to apply over all input sections in
83 the list.
84
e23eba97 85* Add support for the RISC-V architecture.
76359541 86
a05a5b64 87* The command-line option --no-eh-frame-hdr can now be used in ELF based
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88 linkers to disable the automatic generation of .eh_frame_hdr sections.
89
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90* Add --in-implib=<infile> to the ARM linker to enable specifying a set of
91 Secure Gateway veneers that must exist in the output import library specified
92 by --out-implib=<outfile> and the address they must have. As such,
93 --in-implib is only supported in combination with --cmse-implib.
94
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95* Extended the --out-implib=<file> option, previously restricted to x86 PE
96 targets, to any ELF based target. This allows the generation of an import
97 library for an ELF executable, which can then be used by another application
98 to link against the executable.
99
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100Changes in 2.27:
101
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102* Add a configure option --enable-relro to decide whether -z relro should
103 be enabled in ELF linker by default. Default to yes for all Linux
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104 targets except FRV, HPPA, IA64 and MIPS. Note that -z relro can increase
105 disk and memory size.
647e4d46 106
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107* Support for -z noreloc-overflow in the x86-64 ELF linker to disable
108 relocation overflow check.
109
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110* Add -z common/-z nocommon options for ELF targets to control whether to
111 convert common symbols to the STT_COMMON type during a relocatable link.
112
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113* Support for -z nodynamic-undefined-weak in the x86 ELF linker, which
114 avoids dynamic relocations against undefined weak symbols in executable.
115
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116* The NOCROSSREFSTO command was added to the linker script language.
117
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118* Add --no-apply-dynamic-relocs to the AArch64 linker to do not apply link-time
119 values for dynamic relocations.
120
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121Changes in 2.26:
122
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123* Add --fix-stm32l4xx-629360 to the ARM linker to enable a link-time
124 workaround for a bug in the bus matrix / memory controller for some of
125 the STM32 Cortex-M4 based products (STM32L4xx)
81c23f82 126
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127* Add a configure option --enable-compressed-debug-sections={all,ld} to
128 decide whether DWARF debug sections should be compressed by default.
129
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130* Add support for the ARC EM/HS, and ARC600/700 architectures.
131
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132* Experimental support for linker garbage collection (--gc-sections)
133 has been enabled for COFF and PE based targets.
134
a05a5b64 135* New command-line option for ELF targets to compress DWARF debug
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136 sections, --compress-debug-sections=[none|zlib|zlib-gnu|zlib-gabi].
137
a05a5b64 138* New command-line option, --orphan-handling=[place|warn|error|discard], to
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139 adjust how orphan sections are handled. The default is 'place' which gives
140 the current behaviour, 'warn' and 'error' issue a warning or error
141 respectively when orphan sections are found, and 'discard' will discard all
142 orphan sections.
3ea60775 143
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144* Add support for LLVM plugin.
145
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146* Add --print-memory-usage option to report memory blocks usage.
147
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148* Add --require-defined option, it's like --undefined except the new symbol
149 must be defined by the end of the link.
150
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151Changes in 2.25:
152
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153* PE binaries now once again contain real timestamps by default. To disable
154 the inclusion of a timestamp in a PE binary, use the --no-insert-timestamp
a05a5b64 155 command-line option.
eeb14e5a 156
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157* Replace support for openrisc and or32 with support for or1k.
158
a05a5b64 159* Add support for the --build-id command-line option to COFF based targets.
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160
161* x86/x86_64 pe-coff now supports the --build-id option.
162
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163* Add support for the Andes NDS32.
164
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165Changes in 2.24:
166
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167* Add LOG2CEIL() builtin function to the linker script language
168
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169* Add support for the Texas Instruments MSP430X processor.
170
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171* Add support for Altera Nios II.
172
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173* Add support for the V850E3V5 architecture.
174
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175* Add support for the Imagination Technologies Meta processor.
176
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177* --enable-new-dtags no longer generates old dtags in addition to new dtags.
178
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179* Remove linker support for MIPS ECOFF targets.
180
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181* Add ALIGN_WITH_INPUT to the linker script language to force the alignment of
182 an output section to use the maximum alignment of all its input sections.
183
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184Changes in 2.23:
185
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186* Enable compressed debug section feature for x86/x86_64 pe-coff.
187
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188* Add support for the 64-bit ARM architecture: AArch64.
189
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190* Added SORT_NONE to the linker script language to disable section sorting.
191
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192* Add a linker-provided symbol when producing ELF output, '__ehdr_start'
193 to point to the ELF file header (and nearby program headers) in the
194 program's memory image.
195
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196* Add support for S12X processor.
197
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198* Add support for the VLE extension to the PowerPC architecture.
199
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200* Add support for the Freescale XGATE architecture.
201
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202* Add option -f FILE on AIX (for response file).
203
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204* Add support for the Renesas RL78 architecture.
205
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206* Add support for the Adapteva EPIPHANY architecture.
207
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208Changes in 2.22:
209
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210* --copy-dt-needed-entries is no longer enabled by default. Instead
211 --no-copy-dt-needed-entries is the default.
212
ae17ab41 213* INPUT_SECTION_FLAGS has been added to the linker script language
cfb8c092 214 to allow selection of input sections by section header section flags.
ae17ab41 215
69f56ae1 216* Add support for the Tilera TILEPro and TILE-Gx architectures.
90b3661c 217
02ecc8e9 218* Added SORT_BY_INIT_PRIORITY to the linker script language to permit
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219 sorting sections by numerical value of the GCC init_priority attribute
220 encoded in the section name.
02ecc8e9 221
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222Changes in 2.21:
223
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224* Linker script expression evaluation is somewhat more sane. This may
225 break scripts that depend on quirks of the old expression evaluation.
226
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227* Turn off underscoring for x86_64 PE+-COFF targets. For old behavior the
228 option --enable-leading-mingw64-underscores can be used on configure of
229 bfd.
230
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231* Add support for the TMS320C6000 (TI C6X) processor family.
232
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233* --add-needed renamed to --copy-dt-needed-entries in order to avoid confusion
234 with --as-needed option.
235
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236* Extend .def file syntax by '== <ID>' for imports and exports. This allows
237 to alias the import/export table name written in PE image.
238
a72173de 239* Add --exclude-all-symbols option to PE based linkers. This prevents all
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240 symbols from automatically being exported.
241
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242* Add support for the Renesas RX processor.
243
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244* Add support for alpha-vms target.
245
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246Changes in 2.20:
247
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248* GNU/Linux targets now support the STB_GNU_UNIQUE symbol binding. This is a
249 GNU extension to the standard set of ELF symbol bindings. The binding will
250 be passed on to the dynamic linker which will make sure that in the entire
251 process there is just one symbol with the given name and type in use.
ce11ba6c 252
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253* PE targets now support a GNU extension to allow the alignment of common
254 common symbols to be specified. This support uses custom options in
255 the .drectve section, which will be disregarded by the native tools.
256
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257* PE targets now add primitive support for ELF version scripts; symbols
258 are not versioned, but the local and global symbol visibility directives
259 are respected when filtering symbols in auto-export mode.
260
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261* New option --no-export-dynamic to undo the effect of the -E and
262 --export-dynamic options.
263
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264* ELF: --warn-alternate-em option to warn if an object has alternate
265 ELF machine code.
266
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267* New script function REGION_ALIAS to add alias names to memory regions.
268
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269* PE targets no longer make use of the long section names PE extension to
270 the COFF format when generating executable images, by default. The old
271 (slightly non-conformant) behaviour can still be invoked by using the
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272 new '--enable-long-section-names' command-line option. It is also enabled
273 automatically in the presence of un-stripped debug information, as GDB
274 needs to be able to find the debug info sections by their full names.
88183869 275
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276* For GNU/Linux systems the linker will now avoid processing any relocations
277 made against symbols of the STT_GNU_IFUNC type and instead emit them into
278 the resulting binary for processing by the loader.
279
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280* --as-needed now links in a dynamic library if it satisfies undefined
281 symbols in regular objects, or in other dynamic libraries. In the
282 latter case the library is not linked if it is found in a DT_NEEDED
283 entry of one of the libraries already linked.
284
a05a5b64 285* Add a new command-line option, -Ttext-segment ADDR, for ELF targets
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286 to set the address of the first byte of the text segment.
287
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288* Add support for Sunplus score architecture.
289
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290* Add new option --use-nul-prefixed-import-tables to ld for PE targets to
291 allow fallback to old import table generation with null element prefix.
292
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293* Windows PE systems now support a new --exclude-modules-for-implib option,
294 allowing users to partition object files and archive members between a DLL
295 and its associated import library as they are generated during linking.
296
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297* Add support for Lattice Mico32 (lm32) architecture.
298
62655c7b 299* Add CR16 ELF --embedded-relocs (used to embedded relocations into binaries
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300 for Embedded-PIC code) option.
301
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302* Add to the PE/PE+ targets the support of two different kinds of
303 pseudo-relocations. They can be selected by the switches
304 --enable-runtime-pseudo-reloc-v1 and --enable-runtime-pseudo-reloc-v2.
305 For the switch --enable-runtime-pseudo-reloc it uses for 32-bit
306 runtime pseudo relocation version one, for 64-bit the version two.
307
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308Changes in 2.19:
309
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310* Linker scripts support a new INSERT command that makes it easier to
311 augment the default script.
312
967928e9 313* Linker script input section filespecs may now specify a file within an
66c103b7 314 archive by writing "archive:file".
967928e9 315
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316* The --sort-common switch now has an optional argument which specifies the
317 direction of sorting.
318
7fb9f789 319* The M68K linker now supports multiple GOT generation schemes controlled via
a05a5b64 320 the --got=<type> command-line option.
7fb9f789 321
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322* The ARM EABI linker will now generate stubs for function calls to symbols
323 that are too far away. The placement of the stubs is controlled by a new
a05a5b64 324 linker command-line option: --stub-group-size=N.
726150b7 325
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326Changes in 2.18:
327
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328* Linker sources now released under version 3 of the GNU General Public
329 License.
330
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331* ELF: New --build-id option to generate a unique per-binary identifier
332 embedded in a note section.
333
3d3d428f 334* Added support for National Semicondutor CompactRISC (ie CR16) target.
a19bcec6 335
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336* -l:foo now searches the library path for a filename called foo,
337 without converting it to libfoo.a or libfoo.so.
338
a05a5b64 339* Add a new command-line option '--default-script=FILE' or '-dT FILE'
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340 which specifies a replacement for the built in, default linker
341 script.
342
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343* ELF: Add -Bsymbolic-functions, --dynamic-list-cpp-new, which puts C++
344 operator new and delete on the dynamic list, and --dynamic-list-data,
345 builtin list for --dynamic-list, which puts global data symbols on the
346 dynamic list.
347
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348* Add support for x86_64 PE+ target.
349
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350* Add support for Score target.
351
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352* ELF: Add --dynamic-list option to specify a list of global symbols
353 whose references shouldn't be bound to the definition within the
354 shared library, or a list of symbols which should be added to the
355 symbol table in the executable.
356
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357* The default output section LMA has changed for allocatable sections from
358 being equal to VMA, to keeping the difference between LMA and VMA the same as
359 the previous output section in the same region. This is a more useful
360 default when using overlays and other cases where you specify an LMA
361 differing from the VMA for some sections.
362
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363* New switch: --print-gc-sections to list any sections removed by garabge
364 collection.
365
c6dd86c6 366* ARM: Added --vfp11-denorm-fix option to work around an erratum in current
f96b4a7b 367 VFP11 coprocessors.
c6dd86c6 368
c17d87de 369Changes in 2.17:
cf88bb9f 370
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371* Support for the Infineon XC16X has been added by KPIT Cummins Infosystems.
372
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373* Modify the Linux linker search order to better match ld.so search order.
374 Look for DT_NEEDED libraries in paths specified by ld.so.conf before
375 searching the default directories, rather than vice versa.
376 Use $prefix/etc/ld.so.conf if it exists, otherwise /etc/ld.so.conf.
c1446dba 377
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378* PE-COFF: Forward exports from DLL's can now be specified in .def files
379 passed directly to ld.
380
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381* Support for the Z80 processor family has been added.
382
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383* Add support for the "@<file>" syntax to the command line, so that extra
384 switches can be read from <file>.
385
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386Changes in 2.16:
387
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388* Support for the R_ARM_V4BX relocation as defined in the ARM AAELF
389 specification has been added via the --fix-v4bx command-line option.
390
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391* New linker script construct AS_NEEDED(), which sets the --as-needed flag
392 for input files listed inside of it.
393
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394* A new command-line option, --sysroot, can be used to override the
395 default sysroot location. It only applies to toolchains that were
396 configured using --with-sysroot.
397
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398* New linker script functions: ORIGIN() and LENGTH() which return information
399 about a specified memory region.
400
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401* Port to MAXQ processor contributed by HCL Tech.
402
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403* Added SEGMENT_START to the linker script language to permit the user to
404 override the base address for a segment from the command-line.
405
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406* ELF: --warn-shared-textrel option to warn if adding a DT_TEXTREL to a shared
407 object.
408
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409* Added SORT_BY_NAME and SORT_BY_ALIGNMENT to the linker script
410 language to permit sorting sections by section name or section
411 maximum alignment.
412
a05a5b64 413* Added a new linker command-line switch, --sort-section name|alignment,
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414 to sort sections by section name or maximum alignment.
415
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416* ELF: --add-needed/--no-add-needed options to control if a DT_NEEDED tag
417 should be added when a shared library comes from DT_NEEDED tags.
14b3c463 418
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419* Support for the crx-elf target added.
420
1a320fbb 421* Support for the sh-symbianelf target added.
1fe1f39c 422
a05a5b64 423* A new linker command-line switch has been added which allows the hash table
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424 size to be set to a suitable prime value near to its argument. This switch
425 is --hash-size=<NUMBER>. Also if the switch --reduce-memory-overheads is
426 used, and --hash-size has not been used, then the default value will be set
427 to 1021.
428
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429* Linker map files are now generated with an O(N) algorithm for finding symbols
430 that are defined in each section. This uses about 40% more memory for
431 symbols than the old O(N^2) algorithm. You can use the new
432 --reduce-memory-overheads option to select the old algorithm; this option
433 might also be used in the future to select similar tradeoffs.
434
2d643429 435Changes in 2.15:
14b3c463 436
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437* ELF: --as-needed/--no-as-needed options to control if a DT_NEEDED tag should
438 be added only when a shared library is referenced.
c0065db7 439
8fdd7217 440* PE: --large-address-aware option to indicate executables support virtual
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441 addresses greater than 2 gigabytes.
442
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443* DWARF 2 support for i386pe added.
444
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445* The linker script operator DEFINED() will now yield 1 only for a symbol that
446 is defined before the statement where DEFINED is used.
447
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448* The MIPS --embedded-relocs (used to embed relocations into binaries for
449 Embedded-PIC code) is deprecated and will be removed in a future release.
450
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451* cr16c support added by NSC.
452
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453* m32r Linux (ELF) support added by Renesas.
454
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455* Improved linker's handling of unresolved symbols. The switch
456 --unresolved-symbols=<method> has been added to tell the linker when it
457 should report them and the switch --warn-unresolved-symbols has been added to
458 make reports be issued as warning messages rather than errors.
459
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460Changes in 2.14:
461
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462* Added support for Xtensa architecture.
463
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464* Added --with-sysroot configure switch to specify a target system root, for
465 linking against a target filesystem image.
466
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467* Added --accept-unknown-linker-format to restore old linker behaviour (pre
468 2.14) of silently accepting and linking in any files in an unknown binary
469 file format.
470
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471* Added --no-omagic to undo the effects of the -N option.
472
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473* Support for Texas Instruments TMS320C4x and TMS320C3x series of
474 DSP's contributed by Michael Hayes and Svein E. Seldal.
c0065db7 475
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476* Added --with-lib-path configure switch to specify default value for
477 LIB_PATH.
478
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479* ARM port to QNX operating system added by Graeme Peterson.
480
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481* IP2K support added by Denis Chertykov.
482
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483Changes in 2.13:
484
485* Support for the Fujitsu FRV architecture added by Red Hat. Models for FR400
486 and FR500 included.
7d553a40 487
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488Changes in version 2.13:
489
490* DEC VAX ELF support, by Matt Thomas.
491
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492Changes in version 2.12:
493
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494* Support for Don Knuth's MMIX, by Hans-Peter Nilsson.
495
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496* Support for the OpenRISC 32-bit embedded processor by OpenCores.
497
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498* Support for -z nocopyreloc in the x86 ELF linker, which disables
499 production of copy relocs. Warning: using this option may result in
500 non-sharable applications.
5b343f5a 501
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502* Support for -z combreloc in the ELF linker, which puts dynamic
503 relocations against the same symbol together, so that dynamic linker
504 can use an one-entry symbol lookup cache.
505
506* Support for ELF SHF_MERGE section merging, by Jakub Jelinek.
507
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508Changes in version 2.11:
509
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510* Support for AMD x86-64 architecture, by Jan Hubicka, SuSE Labs.
511
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512* Support added for eliminating duplicate DWARF2 debug information by
513 having the compiler generate the information in sections called
514 .gnu.linkonce.wi.XXXX where XXXX is a checksum for the contents. The
515 linker then merges these sections together into the normal .debug_info
516 section.
252b5132 517
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518* The native ELF linker now searches the directories in DT_RUNPATH or
519 DT_RPATH of a shared library for shared libraries needed by it.
520
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521* TI C54x support, by Timothy Wall.
522
a05a5b64 523* Added command-line switch --section-start to set the start address of any
c0065db7 524 specified section.
176355da 525
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526* Added ability to emit full relocation information in linked executables,
527 enabled by --emit-relocs. Some post-linkage optimization tools need
528 this information in order to be able to correctly identify and perform
529 symbol relative addressing in the event of changes in section contents
530 (instructions being added or deleted, extending data sections, etc.)
531
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532* Support for i860, by Jason Eckhardt (preliminary, alpha quality).
533
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534* Support for CRIS (Axis Communications ETRAX series).
535
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536* Support for PDP-11 and 2.11BSD a.out format, by Lars Brinkhoff.
537
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538Changes in version 2.10:
539
c0065db7 540* Added AT> to the linker script language to allow load-time allocation of
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541 sections into regions.
542
c0065db7 543* Added garbage collection of unused sections, enabled by --gc-sections.
252b5132 544 It does require a bit of backend support; currently implemented are
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545 arm-elf, avr-elf, d10v-elf, fr30-elf, i386-elf, m32r-elf, m68k-elf,
546 mcore-elf, mips-elf, mn10300-elf, ppc-elf, sh-elf, sparc-elf, and v850-elf.
987fd5b4 547 Others will ignore the option.
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548
549* Added SORT to the linker script language to permit sorting sections by file
550 name or section name.
551
552* Added EXTERN to the linker script language as an equivalent to the -u
553 command-line option.
554
555* Added ASSERT to the linker script language.
556
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557* Added EXCLUDE_FILE to the linker script language for further control over
558 wildcard file names.
559
252b5132 560* Added -O option to optimize linker output (as of this writing, this only
500800ca 561 affects ELF shared library generation).
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562
563* The -e option now accepts a number as well as a symbol name.
564
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565* Added --no-undefined option to disallow undefined symbols when creating a
566 shared library.
567
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568* The linker now issues a warning, not an error, for an undefined symbol when
569 using -Bsymbolic; use the new --no-undefined option to get the old
570 behaviour.
571
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572* Added --demangle and --no-demangle options.
573
574Changes in version 2.9:
575
576* Added SQUAD to the linker script language.
577
578* New option --no-warn-mismatch.
579
580* The MEMORY command now parses the attributes to determine where sections that
581 are not placed in a specific memory region are placed.
582
583Changes in version 2.8:
584
585* Linker scripts may now contain shell wildcard characters for file and section
586 names.
587
588* The linker now supports symbol versions in ELF.
589
590* The NOCROSSREFS command was added to the linker script language.
591
592* The LOADADDR expression was added to the linker script language.
593
594* MAX and MIN functions were added to the linker script language.
595
596* The OVERLAY construct was added to the linker script language.
597
598* New option --warn-section-align to warn when the address of an output section
599 changes due to alignment of an input section.
600
601* New options --filter/-F and --auxiliary/-f.
602
603Changes in version 2.7:
604
605* New option --cref to print out a cross reference table.
606
607* New option --wrap SYMBOL.
608
609* New option --no-whole-archive, to turn off the effect of --whole-archive.
610
611* Input sections assigned to the output section /DISCARD/ in the linker script
612 are not included in the output file.
613
614* The SunOS and ELF linkers now merge stabs debugging information which uses
615 the N_BINCL and N_EINCL stab types. This reduces the amount of debugging
616 information generated.
617
618Changes in version 2.6:
619
620* When an ELF section name is representable as a C identifier (this is not true
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621of most ELF section names), the linker will automatically define symbols
622__start_SECNAME and __stop_SECNAME, where SECNAME is the section name, at the
623beginning and the end of the section. This is used by glibc.
624
625 Addendum: Current versions of the linker (at least for version 2.18 onwards
626and possibly much earlier as well) place two restrictions on this feature: The
627symbols are only implemented for orphaned sections, not for explicitly placed
628sections and they are PROVIDEd rather than being defined.
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629
630* When an ELF section named .gnu.warning is encountered in an input file, the
631contents of the section are displayed as an error message, and the section is
632not copied into the output file. This is used by glibc.
633
634* When an ELF section named .gnu.warning.SYMBOL is encountered in an input
635file, and the symbol SYMBOL is referenced by some object file, the contents of
636the section are displayed as an error message. The section is not copied into
1049f94e 637the output file, unless doing a relocatable or shared link. This is used by
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638glibc.
639
640* New options -split-by-reloc and -split-by-file.
641
642* The linker now supports linking PIC compiled code on SPARC SunOS. It can
643also create SPARC SunOS shared libraries, and, like the native SunOS linker,
644will do so whenever there is an undefined symbol in the link and neither the -e
645nor the -r option was used.
646
647* The -rpath option may be used on SunOS to set the list of directories to be
648searched at run time. This overrides the default of building the list from the
649-L options.
650
651* The COFF linker now combines debugging information for structs, unions, and
652enums, so that even if the same type is defined in multiple input files it will
653only be defined once in the output file. The --traditional-format switch will
654prevent this optimization.
655
656Changes in version 2.5:
657
658* The linker now supports linking against SunOS shared libraries. It still can
659not link SunOS PIC (Position Independent Code) files, so it can not be used to
07f3b6ad 660generate shared libraries.
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661
662* The linker now supports linking against ELF shared libraries for the i386
663(UnixWare) and SPARC (Solaris). It can also link ELF PIC files, and can be
664used to generate shared libraries. Shared library generation is not well
665tested; please report any problems encountered. The linker is now enabled for
666Solaris again.
667
668* Eric Youngdale has contributed Linux support code, including linking against
669Linux a.out shared libraries. The linker produces Linux QMAGIC binaries.
670
671* The ELF backend has been converted to the new linker code. To use the new
672ELF linker, each particular target requires a relocation function. So far,
673this function has been written for i386 (UnixWare), SPARC (Solaris) MIPS (Irix
6745), and HPPA ELF targets.
675
676* The -( (--start-group) and -) (--end-group) options have been added to
677support searching a group of archives as though they were a single archive.
678This can also be used in a linker script, as GROUP ( files ).
679
680* When a file is named on the command line, and the linker does not recognize
681it as an object file, the linker will now treat the file as a linker script
682file. A linker script named in this way augments, but does not replace, the
683default linker script.
684
685* The -warn-once option was added. It causes the linker to only warn once per
686undefined symbol, rather than once per reference.
687
688* The COFF backend has been converted to the new linker code. As with ELF, to
689use the new linker, each particular target requires a relocation function. So
690far, this function has been written for the i386, m68k, a29k and SH targets.
691
692* The -V flag was made a synonym for -v, for SVR4 compatibility. The old -V
693behaviour is available via --verbose.
694
695Changes in version 2.4:
696
697* New linker code, by Steve Chamberlain and Ian Taylor. For a.out and ecoff
698 formats (so far), this should result in considerable savings in time
699 and memory used while linking; slightly poorer performance than
700 before for formats not converted yet.
701
702* Command-line parsing is no longer done with flex. This means
703 oddball characters in filenames won't get treated as argument
704 separators.
705
706* HP-PA ELF support, by Jeff Law. (No SOM support yet.)
707
708* Mach i386 support, by David Mackenzie.
709
710* Irix 4 shared libraries are now supported (Irix 5 uses ELF, and ELF shared
711 libraries are not yet supported).
712
713* COFF shared libraries (as on SCO) should work as well.
714
715* The linker is disabled for Solaris. (Actually, it was in 2.3 also, I just
716 forgot to note it.) Some of their C library routines don't work when
717 statically linked, and the GNU linker doesn't support dynamic linking yet.
718
719Changes in version 2.3:
720
721* Weak symbols are now supported.
722
723* ELF support has been added. The linker has been bootstrapped on
724 UnixWare and Solaris.
725
726* Alpha OSF/1 support has been added (non dynamic linking only).
727
728Changes in version 2.2:
729
730* The `bfd' library has been updated to reduce a.out-format string
731 table size. The effect of this is that files linked from many input
732 files with duplicate symbols (`-g' debugging records, or identical
733 static symbols) should be much smaller.
734
735Changes in version 2.1:
736
737* The ld -ySYMBOL flag (to trace references to SYMBOL) is now implemented.
738
739* There is now support for writing ECOFF files, so ld and the
740 other utilities should work on Risc/Ultrix and Irix.
741
742\f
82704155 743Copyright (C) 2012-2019 Free Software Foundation, Inc.
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744
745Copying and distribution of this file, with or without modification,
746are permitted in any medium without royalty provided the copyright
747notice and this notice are preserved.
748
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749Local variables:
750fill-column: 79
751End: