ld/NEWS

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