1-*- text -*- 2 3* The linker script operator DEFINED() will now yield 1 only for a symbol that 4 is defined before the statement where DEFINED is used. 5 6* The MIPS --embedded-relocs (used to embed relocations into binaries for 7 Embedded-PIC code) is deprecated and will be removed in a future release. 8 9* m32r Linux (ELF) support added by Renesas. 10 11* Improved linker's handling of unresolved symbols. The switch 12 --unresolved-symbols=<method> has been added to tell the linker when it 13 should report them and the switch --warn-unresolved-symbols has been added to 14 make reports be issued as warning messages rather than errors. 15 16Changes in 2.14: 17 18* Added support for Xtensa architecture. 19 20* Added --with-sysroot configure switch to specify a target system root, for 21 linking against a target filesystem image. 22 23* Added --accept-unknown-linker-format to restore old linker behaviour (pre 24 2.14) of silently accepting and linking in any files in an unknown binary 25 file format. 26 27* Added --no-omagic to undo the effects of the -N option. 28 29* Support for Texas Instruments TMS320C4x and TMS320C3x series of 30 DSP's contributed by Michael Hayes and Svein E. Seldal. 31 32* Added --with-lib-path configure switch to specify default value for 33 LIB_PATH. 34 35* ARM port to QNX operating system added by Graeme Peterson. 36 37* IP2K support added by Denis Chertykov. 38 39Changes in 2.13: 40 41* Support for the Fujitsu FRV architecture added by Red Hat. Models for FR400 42 and FR500 included. 43 44Changes in version 2.13: 45 46* DEC VAX ELF support, by Matt Thomas. 47 48Changes in version 2.12: 49 50* Support for Don Knuth's MMIX, by Hans-Peter Nilsson. 51 52* Support for the OpenRISC 32-bit embedded processor by OpenCores. 53 54* Support for -z nocopyreloc in the x86 ELF linker, which disables 55 production of copy relocs. Warning: using this option may result in 56 non-sharable applications. 57 58* Support for -z combreloc in the ELF linker, which puts dynamic 59 relocations against the same symbol together, so that dynamic linker 60 can use an one-entry symbol lookup cache. 61 62* Support for ELF SHF_MERGE section merging, by Jakub Jelinek. 63 64Changes in version 2.11: 65 66* Support for AMD x86-64 architecture, by Jan Hubicka, SuSE Labs. 67 68* Support added for eliminating duplicate DWARF2 debug information by 69 having the compiler generate the information in sections called 70 .gnu.linkonce.wi.XXXX where XXXX is a checksum for the contents. The 71 linker then merges these sections together into the normal .debug_info 72 section. 73 74* The native ELF linker now searches the directories in DT_RUNPATH or 75 DT_RPATH of a shared library for shared libraries needed by it. 76 77* TI C54x support, by Timothy Wall. 78 79* Added command line switch --section-start to set the start address of any 80 specified section. 81 82* Added ability to emit full relocation information in linked executables, 83 enabled by --emit-relocs. Some post-linkage optimization tools need 84 this information in order to be able to correctly identify and perform 85 symbol relative addressing in the event of changes in section contents 86 (instructions being added or deleted, extending data sections, etc.) 87 88* Support for i860, by Jason Eckhardt (preliminary, alpha quality). 89 90* Support for CRIS (Axis Communications ETRAX series). 91 92* Support for PDP-11 and 2.11BSD a.out format, by Lars Brinkhoff. 93 94Changes in version 2.10: 95 96* Added AT> to the linker script language to allow load-time allocation of 97 sections into regions. 98 99* Added garbage collection of unused sections, enabled by --gc-sections. 100 It does require a bit of backend support; currently implemented are 101 arm-elf, avr-elf, d10v-elf, fr30-elf, i386-elf, m32r-elf, m68k-elf, 102 mcore-elf, mips-elf, mn10300-elf, ppc-elf, sh-elf, sparc-elf, and v850-elf. 103 Others will ignore the option. 104 105* Added SORT to the linker script language to permit sorting sections by file 106 name or section name. 107 108* Added EXTERN to the linker script language as an equivalent to the -u 109 command-line option. 110 111* Added ASSERT to the linker script language. 112 113* Added EXCLUDE_FILE to the linker script language for further control over 114 wildcard file names. 115 116* Added -O option to optimize linker output (as of this writing, this only 117 affects ELF shared library generation). 118 119* The -e option now accepts a number as well as a symbol name. 120 121* Added --no-undefined option to disallow undefined symbols when creating a 122 shared library. 123 124* The linker now issues a warning, not an error, for an undefined symbol when 125 using -Bsymbolic; use the new --no-undefined option to get the old 126 behaviour. 127 128* Added --demangle and --no-demangle options. 129 130Changes in version 2.9: 131 132* Added SQUAD to the linker script language. 133 134* New option --no-warn-mismatch. 135 136* The MEMORY command now parses the attributes to determine where sections that 137 are not placed in a specific memory region are placed. 138 139Changes in version 2.8: 140 141* Linker scripts may now contain shell wildcard characters for file and section 142 names. 143 144* The linker now supports symbol versions in ELF. 145 146* The NOCROSSREFS command was added to the linker script language. 147 148* The LOADADDR expression was added to the linker script language. 149 150* MAX and MIN functions were added to the linker script language. 151 152* The OVERLAY construct was added to the linker script language. 153 154* New option --warn-section-align to warn when the address of an output section 155 changes due to alignment of an input section. 156 157* New options --filter/-F and --auxiliary/-f. 158 159Changes in version 2.7: 160 161* New option --cref to print out a cross reference table. 162 163* New option --wrap SYMBOL. 164 165* New option --no-whole-archive, to turn off the effect of --whole-archive. 166 167* Input sections assigned to the output section /DISCARD/ in the linker script 168 are not included in the output file. 169 170* The SunOS and ELF linkers now merge stabs debugging information which uses 171 the N_BINCL and N_EINCL stab types. This reduces the amount of debugging 172 information generated. 173 174Changes in version 2.6: 175 176* When an ELF section name is representable as a C identifier (this is not true 177of most ELF section names), the linker will automatically define symbols 178__start_SECNAME and __stop_SECNAME, where SECNAME is the section name, at the 179beginning and the end of the section. This is used by glibc. 180 181* When an ELF section named .gnu.warning is encountered in an input file, the 182contents of the section are displayed as an error message, and the section is 183not copied into the output file. This is used by glibc. 184 185* When an ELF section named .gnu.warning.SYMBOL is encountered in an input 186file, and the symbol SYMBOL is referenced by some object file, the contents of 187the section are displayed as an error message. The section is not copied into 188the output file, unless doing a relocatable or shared link. This is used by 189glibc. 190 191* New options -split-by-reloc and -split-by-file. 192 193* The linker now supports linking PIC compiled code on SPARC SunOS. It can 194also create SPARC SunOS shared libraries, and, like the native SunOS linker, 195will do so whenever there is an undefined symbol in the link and neither the -e 196nor the -r option was used. 197 198* The -rpath option may be used on SunOS to set the list of directories to be 199searched at run time. This overrides the default of building the list from the 200-L options. 201 202* The COFF linker now combines debugging information for structs, unions, and 203enums, so that even if the same type is defined in multiple input files it will 204only be defined once in the output file. The --traditional-format switch will 205prevent this optimization. 206 207Changes in version 2.5: 208 209* The linker now supports linking against SunOS shared libraries. It still can 210not link SunOS PIC (Position Independent Code) files, so it can not be used to 211generate shared libraries. 212 213* The linker now supports linking against ELF shared libraries for the i386 214(UnixWare) and SPARC (Solaris). It can also link ELF PIC files, and can be 215used to generate shared libraries. Shared library generation is not well 216tested; please report any problems encountered. The linker is now enabled for 217Solaris again. 218 219* Eric Youngdale has contributed Linux support code, including linking against 220Linux a.out shared libraries. The linker produces Linux QMAGIC binaries. 221 222* The ELF backend has been converted to the new linker code. To use the new 223ELF linker, each particular target requires a relocation function. So far, 224this function has been written for i386 (UnixWare), SPARC (Solaris) MIPS (Irix 2255), and HPPA ELF targets. 226 227* The -( (--start-group) and -) (--end-group) options have been added to 228support searching a group of archives as though they were a single archive. 229This can also be used in a linker script, as GROUP ( files ). 230 231* When a file is named on the command line, and the linker does not recognize 232it as an object file, the linker will now treat the file as a linker script 233file. A linker script named in this way augments, but does not replace, the 234default linker script. 235 236* The -warn-once option was added. It causes the linker to only warn once per 237undefined symbol, rather than once per reference. 238 239* The COFF backend has been converted to the new linker code. As with ELF, to 240use the new linker, each particular target requires a relocation function. So 241far, this function has been written for the i386, m68k, a29k and SH targets. 242 243* The -V flag was made a synonym for -v, for SVR4 compatibility. The old -V 244behaviour is available via --verbose. 245 246Changes in version 2.4: 247 248* New linker code, by Steve Chamberlain and Ian Taylor. For a.out and ecoff 249 formats (so far), this should result in considerable savings in time 250 and memory used while linking; slightly poorer performance than 251 before for formats not converted yet. 252 253* Command-line parsing is no longer done with flex. This means 254 oddball characters in filenames won't get treated as argument 255 separators. 256 257* HP-PA ELF support, by Jeff Law. (No SOM support yet.) 258 259* Mach i386 support, by David Mackenzie. 260 261* Irix 4 shared libraries are now supported (Irix 5 uses ELF, and ELF shared 262 libraries are not yet supported). 263 264* COFF shared libraries (as on SCO) should work as well. 265 266* The linker is disabled for Solaris. (Actually, it was in 2.3 also, I just 267 forgot to note it.) Some of their C library routines don't work when 268 statically linked, and the GNU linker doesn't support dynamic linking yet. 269 270Changes in version 2.3: 271 272* Weak symbols are now supported. 273 274* ELF support has been added. The linker has been bootstrapped on 275 UnixWare and Solaris. 276 277* Alpha OSF/1 support has been added (non dynamic linking only). 278 279Changes in version 2.2: 280 281* The `bfd' library has been updated to reduce a.out-format string 282 table size. The effect of this is that files linked from many input 283 files with duplicate symbols (`-g' debugging records, or identical 284 static symbols) should be much smaller. 285 286Changes in version 2.1: 287 288* The ld -ySYMBOL flag (to trace references to SYMBOL) is now implemented. 289 290* There is now support for writing ECOFF files, so ld and the 291 other utilities should work on Risc/Ultrix and Irix. 292 293 294Local variables: 295fill-column: 79 296End: 297