| 1 | -*- text -*- |
| 2 | * Support for -z nocopyreloc in the x86 ELF linker, which disables |
| 3 | production of copy relocs. Warning: using this option may result in |
| 4 | non-sharable applications. |
| 5 | |
| 6 | * Support for -z combreloc in the ELF linker, which puts dynamic |
| 7 | relocations against the same symbol together, so that dynamic linker |
| 8 | can use an one-entry symbol lookup cache. |
| 9 | |
| 10 | * Support for ELF SHF_MERGE section merging, by Jakub Jelinek. |
| 11 | |
| 12 | * Support for AMD x86-64 architecture, by Jan Hubicka, SuSE Labs. |
| 13 | |
| 14 | * Support added for eliminating duplicate DWARF2 debug information by |
| 15 | having the compiler generate the information in sections called |
| 16 | .gnu.linkonce.wi.XXXX where XXXX is a checksum for the contents. The |
| 17 | linker then merges these sections together into the normal .debug_info |
| 18 | section. |
| 19 | |
| 20 | * The native ELF linker now searches the directories in DT_RUNPATH or |
| 21 | DT_RPATH of a shared library for shared libraries needed by it. |
| 22 | |
| 23 | * TI C54x support, by Timothy Wall. |
| 24 | |
| 25 | * Added command line switch --section-start to set the start address of any |
| 26 | specified section. |
| 27 | |
| 28 | * Added ability to emit full relocation information in linked executables, |
| 29 | enabled by --emit-relocs. Some post-linkage optimization tools need |
| 30 | this information in order to be able to correctly identify and perform |
| 31 | symbol relative addressing in the event of changes in section contents |
| 32 | (instructions being added or deleted, extending data sections, etc.) |
| 33 | |
| 34 | * Support for i860, by Jason Eckhardt (preliminary, alpha quality). |
| 35 | |
| 36 | * Support for CRIS (Axis Communications ETRAX series). |
| 37 | |
| 38 | Changes in version 2.10: |
| 39 | |
| 40 | * Added AT> to the linker script language to allow load-time allocation of |
| 41 | sections into regions. |
| 42 | |
| 43 | * Added garbage collection of unused sections, enabled by --gc-sections. |
| 44 | It does require a bit of backend support; currently implemented are |
| 45 | arm-elf, avr-elf, d10v-elf, fr30-elf, i386-elf, m32r-elf, m68k-elf, |
| 46 | mcore-elf, mips-elf, mn10300-elf, ppc-elf, sh-elf, sparc-elf, and v850-elf. |
| 47 | Others will ignore the option. |
| 48 | |
| 49 | * Added SORT to the linker script language to permit sorting sections by file |
| 50 | name or section name. |
| 51 | |
| 52 | * Added EXTERN to the linker script language as an equivalent to the -u |
| 53 | command-line option. |
| 54 | |
| 55 | * Added ASSERT to the linker script language. |
| 56 | |
| 57 | * Added EXCLUDE_FILE to the linker script language for further control over |
| 58 | wildcard file names. |
| 59 | |
| 60 | * Added -O option to optimize linker output (as of this writing, this only |
| 61 | affects ELF shared library generation). |
| 62 | |
| 63 | * The -e option now accepts a number as well as a symbol name. |
| 64 | |
| 65 | * Added --no-undefined option to disallow undefined symbols when creating a |
| 66 | shared library. |
| 67 | |
| 68 | * The linker now issues a warning, not an error, for an undefined symbol when |
| 69 | using -Bsymbolic; use the new --no-undefined option to get the old |
| 70 | behaviour. |
| 71 | |
| 72 | * Added --demangle and --no-demangle options. |
| 73 | |
| 74 | Changes in version 2.9: |
| 75 | |
| 76 | * Added SQUAD to the linker script language. |
| 77 | |
| 78 | * New option --no-warn-mismatch. |
| 79 | |
| 80 | * The MEMORY command now parses the attributes to determine where sections that |
| 81 | are not placed in a specific memory region are placed. |
| 82 | |
| 83 | Changes in version 2.8: |
| 84 | |
| 85 | * Linker scripts may now contain shell wildcard characters for file and section |
| 86 | names. |
| 87 | |
| 88 | * The linker now supports symbol versions in ELF. |
| 89 | |
| 90 | * The NOCROSSREFS command was added to the linker script language. |
| 91 | |
| 92 | * The LOADADDR expression was added to the linker script language. |
| 93 | |
| 94 | * MAX and MIN functions were added to the linker script language. |
| 95 | |
| 96 | * The OVERLAY construct was added to the linker script language. |
| 97 | |
| 98 | * New option --warn-section-align to warn when the address of an output section |
| 99 | changes due to alignment of an input section. |
| 100 | |
| 101 | * New options --filter/-F and --auxiliary/-f. |
| 102 | |
| 103 | Changes in version 2.7: |
| 104 | |
| 105 | * New option --cref to print out a cross reference table. |
| 106 | |
| 107 | * New option --wrap SYMBOL. |
| 108 | |
| 109 | * New option --no-whole-archive, to turn off the effect of --whole-archive. |
| 110 | |
| 111 | * Input sections assigned to the output section /DISCARD/ in the linker script |
| 112 | are not included in the output file. |
| 113 | |
| 114 | * The SunOS and ELF linkers now merge stabs debugging information which uses |
| 115 | the N_BINCL and N_EINCL stab types. This reduces the amount of debugging |
| 116 | information generated. |
| 117 | |
| 118 | Changes in version 2.6: |
| 119 | |
| 120 | * When an ELF section name is representable as a C identifier (this is not true |
| 121 | of most ELF section names), the linker will automatically define symbols |
| 122 | __start_SECNAME and __stop_SECNAME, where SECNAME is the section name, at the |
| 123 | beginning and the end of the section. This is used by glibc. |
| 124 | |
| 125 | * When an ELF section named .gnu.warning is encountered in an input file, the |
| 126 | contents of the section are displayed as an error message, and the section is |
| 127 | not copied into the output file. This is used by glibc. |
| 128 | |
| 129 | * When an ELF section named .gnu.warning.SYMBOL is encountered in an input |
| 130 | file, and the symbol SYMBOL is referenced by some object file, the contents of |
| 131 | the section are displayed as an error message. The section is not copied into |
| 132 | the output file, unless doing a relocateable or shared link. This is used by |
| 133 | glibc. |
| 134 | |
| 135 | * New options -split-by-reloc and -split-by-file. |
| 136 | |
| 137 | * The linker now supports linking PIC compiled code on SPARC SunOS. It can |
| 138 | also create SPARC SunOS shared libraries, and, like the native SunOS linker, |
| 139 | will do so whenever there is an undefined symbol in the link and neither the -e |
| 140 | nor the -r option was used. |
| 141 | |
| 142 | * The -rpath option may be used on SunOS to set the list of directories to be |
| 143 | searched at run time. This overrides the default of building the list from the |
| 144 | -L options. |
| 145 | |
| 146 | * The COFF linker now combines debugging information for structs, unions, and |
| 147 | enums, so that even if the same type is defined in multiple input files it will |
| 148 | only be defined once in the output file. The --traditional-format switch will |
| 149 | prevent this optimization. |
| 150 | |
| 151 | Changes in version 2.5: |
| 152 | |
| 153 | * The linker now supports linking against SunOS shared libraries. It still can |
| 154 | not link SunOS PIC (Position Independent Code) files, so it can not be used to |
| 155 | generate shared libaries. |
| 156 | |
| 157 | * The linker now supports linking against ELF shared libraries for the i386 |
| 158 | (UnixWare) and SPARC (Solaris). It can also link ELF PIC files, and can be |
| 159 | used to generate shared libraries. Shared library generation is not well |
| 160 | tested; please report any problems encountered. The linker is now enabled for |
| 161 | Solaris again. |
| 162 | |
| 163 | * Eric Youngdale has contributed Linux support code, including linking against |
| 164 | Linux a.out shared libraries. The linker produces Linux QMAGIC binaries. |
| 165 | |
| 166 | * The ELF backend has been converted to the new linker code. To use the new |
| 167 | ELF linker, each particular target requires a relocation function. So far, |
| 168 | this function has been written for i386 (UnixWare), SPARC (Solaris) MIPS (Irix |
| 169 | 5), and HPPA ELF targets. |
| 170 | |
| 171 | * The -( (--start-group) and -) (--end-group) options have been added to |
| 172 | support searching a group of archives as though they were a single archive. |
| 173 | This can also be used in a linker script, as GROUP ( files ). |
| 174 | |
| 175 | * When a file is named on the command line, and the linker does not recognize |
| 176 | it as an object file, the linker will now treat the file as a linker script |
| 177 | file. A linker script named in this way augments, but does not replace, the |
| 178 | default linker script. |
| 179 | |
| 180 | * The -warn-once option was added. It causes the linker to only warn once per |
| 181 | undefined symbol, rather than once per reference. |
| 182 | |
| 183 | * The COFF backend has been converted to the new linker code. As with ELF, to |
| 184 | use the new linker, each particular target requires a relocation function. So |
| 185 | far, this function has been written for the i386, m68k, a29k and SH targets. |
| 186 | |
| 187 | * The -V flag was made a synonym for -v, for SVR4 compatibility. The old -V |
| 188 | behaviour is available via --verbose. |
| 189 | |
| 190 | Changes in version 2.4: |
| 191 | |
| 192 | * New linker code, by Steve Chamberlain and Ian Taylor. For a.out and ecoff |
| 193 | formats (so far), this should result in considerable savings in time |
| 194 | and memory used while linking; slightly poorer performance than |
| 195 | before for formats not converted yet. |
| 196 | |
| 197 | * Command-line parsing is no longer done with flex. This means |
| 198 | oddball characters in filenames won't get treated as argument |
| 199 | separators. |
| 200 | |
| 201 | * HP-PA ELF support, by Jeff Law. (No SOM support yet.) |
| 202 | |
| 203 | * Mach i386 support, by David Mackenzie. |
| 204 | |
| 205 | * Irix 4 shared libraries are now supported (Irix 5 uses ELF, and ELF shared |
| 206 | libraries are not yet supported). |
| 207 | |
| 208 | * COFF shared libraries (as on SCO) should work as well. |
| 209 | |
| 210 | * The linker is disabled for Solaris. (Actually, it was in 2.3 also, I just |
| 211 | forgot to note it.) Some of their C library routines don't work when |
| 212 | statically linked, and the GNU linker doesn't support dynamic linking yet. |
| 213 | |
| 214 | Changes in version 2.3: |
| 215 | |
| 216 | * Weak symbols are now supported. |
| 217 | |
| 218 | * ELF support has been added. The linker has been bootstrapped on |
| 219 | UnixWare and Solaris. |
| 220 | |
| 221 | * Alpha OSF/1 support has been added (non dynamic linking only). |
| 222 | |
| 223 | Changes in version 2.2: |
| 224 | |
| 225 | * The `bfd' library has been updated to reduce a.out-format string |
| 226 | table size. The effect of this is that files linked from many input |
| 227 | files with duplicate symbols (`-g' debugging records, or identical |
| 228 | static symbols) should be much smaller. |
| 229 | |
| 230 | Changes in version 2.1: |
| 231 | |
| 232 | * The ld -ySYMBOL flag (to trace references to SYMBOL) is now implemented. |
| 233 | |
| 234 | * There is now support for writing ECOFF files, so ld and the |
| 235 | other utilities should work on Risc/Ultrix and Irix. |
| 236 | |
| 237 | \f |
| 238 | Local variables: |
| 239 | fill-column: 79 |
| 240 | End: |