ld/NEWS

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