ld/NEWS

   1 -*- text -*-
   2
   3 * cr16c support added by NSC.
   4
   5 * m32r Linux (ELF) support added by Renesas.
   6
   7 * Improved linker's handling of unresolved symbols.  The switch
   8   --unresolved-symbols=<method> has been added to tell the linker when it
   9   should report them and the switch --warn-unresolved-symbols has been added to
  10   make reports be issued as warning messages rather than errors.
  11
  12 Changes in 2.14:
  13
  14 * Added support for Xtensa architecture.
  15
  16 * Added --with-sysroot configure switch to specify a target system root, for
  17   linking against a target filesystem image.
  18
  19 * Added --accept-unknown-linker-format to restore old linker behaviour (pre
  20   2.14) of silently accepting and linking in any files in an unknown binary
  21   file format.
  22
  23 * Added --no-omagic to undo the effects of the -N option.
  24
  25 * Support for Texas Instruments TMS320C4x and TMS320C3x series of
  26   DSP's contributed by Michael Hayes and Svein E. Seldal.
  27
  28 * Added --with-lib-path configure switch to specify default value for
  29   LIB_PATH.
  30
  31 * ARM port to QNX operating system added by Graeme Peterson.
  32
  33 * IP2K support added by Denis Chertykov.
  34
  35 Changes in 2.13:
  36
  37 * Support for the Fujitsu FRV architecture added by Red Hat. Models for FR400
  38   and FR500 included.
  39
  40 Changes in version 2.13:
  41
  42 * DEC VAX ELF support, by Matt Thomas.
  43
  44 Changes in version 2.12:
  45
  46 * Support for Don Knuth's MMIX, by Hans-Peter Nilsson.
  47
  48 * Support for the OpenRISC 32-bit embedded processor by OpenCores.
  49
  50 * Support for -z nocopyreloc in the x86 ELF linker, which disables
  51   production of copy relocs.  Warning: using this option may result in
  52   non-sharable applications.
  53
  54 * Support for -z combreloc in the ELF linker, which puts dynamic
  55   relocations against the same symbol together, so that dynamic linker
  56   can use an one-entry symbol lookup cache.
  57
  58 * Support for ELF SHF_MERGE section merging, by Jakub Jelinek.
  59
  60 Changes in version 2.11:
  61
  62 * Support for AMD x86-64 architecture, by Jan Hubicka, SuSE Labs.
  63
  64 * Support added for eliminating duplicate DWARF2 debug information by
  65   having the compiler generate the information in sections called
  66   .gnu.linkonce.wi.XXXX where XXXX is a checksum for the contents.  The
  67   linker then merges these sections together into the normal .debug_info
  68   section.
  69
  70 * The native ELF linker now searches the directories in DT_RUNPATH or
  71   DT_RPATH of a shared library for shared libraries needed by it.
  72
  73 * TI C54x support, by Timothy Wall.
  74
  75 * Added command line switch --section-start to set the start address of any
  76   specified section.
  77
  78 * Added ability to emit full relocation information in linked executables,
  79   enabled by --emit-relocs.  Some post-linkage optimization tools need
  80   this information in order to be able to correctly identify and perform
  81   symbol relative addressing in the event of changes in section contents
  82   (instructions being added or deleted, extending data sections, etc.)
  83
  84 * Support for i860, by Jason Eckhardt (preliminary, alpha quality).
  85
  86 * Support for CRIS (Axis Communications ETRAX series).
  87
  88 * Support for PDP-11 and 2.11BSD a.out format, by Lars Brinkhoff.
  89
  90 Changes in version 2.10:
  91
  92 * Added AT> to the linker script language to allow load-time allocation of
  93   sections into regions.
  94
  95 * Added garbage collection of unused sections, enabled by --gc-sections.
  96   It does require a bit of backend support; currently implemented are
  97   arm-elf, avr-elf, d10v-elf, fr30-elf, i386-elf, m32r-elf, m68k-elf,
  98   mcore-elf, mips-elf, mn10300-elf, ppc-elf, sh-elf, sparc-elf, and v850-elf.
  99   Others will ignore the option.
 100
 101 * Added SORT to the linker script language to permit sorting sections by file
 102   name or section name.
 103
 104 * Added EXTERN to the linker script language as an equivalent to the -u
 105   command-line option.
 106
 107 * Added ASSERT to the linker script language.
 108
 109 * Added EXCLUDE_FILE to the linker script language for further control over
 110   wildcard file names.
 111
 112 * Added -O option to optimize linker output (as of this writing, this only
 113   affects ELF shared library generation).
 114
 115 * The -e option now accepts a number as well as a symbol name.
 116
 117 * Added --no-undefined option to disallow undefined symbols when creating a
 118   shared library.
 119
 120 * The linker now issues a warning, not an error, for an undefined symbol when
 121   using -Bsymbolic; use the new --no-undefined option to get the old
 122   behaviour.
 123
 124 * Added --demangle and --no-demangle options.
 125
 126 Changes in version 2.9:
 127
 128 * Added SQUAD to the linker script language.
 129
 130 * New option --no-warn-mismatch.
 131
 132 * The MEMORY command now parses the attributes to determine where sections that
 133   are not placed in a specific memory region are placed.
 134
 135 Changes in version 2.8:
 136
 137 * Linker scripts may now contain shell wildcard characters for file and section
 138   names.
 139
 140 * The linker now supports symbol versions in ELF.
 141
 142 * The NOCROSSREFS command was added to the linker script language.
 143
 144 * The LOADADDR expression was added to the linker script language.
 145
 146 * MAX and MIN functions were added to the linker script language.
 147
 148 * The OVERLAY construct was added to the linker script language.
 149
 150 * New option --warn-section-align to warn when the address of an output section
 151   changes due to alignment of an input section.
 152
 153 * New options --filter/-F and --auxiliary/-f.
 154
 155 Changes in version 2.7:
 156
 157 * New option --cref to print out a cross reference table.
 158
 159 * New option --wrap SYMBOL.
 160
 161 * New option --no-whole-archive, to turn off the effect of --whole-archive.
 162
 163 * Input sections assigned to the output section /DISCARD/ in the linker script
 164   are not included in the output file.
 165
 166 * The SunOS and ELF linkers now merge stabs debugging information which uses
 167   the N_BINCL and N_EINCL stab types.  This reduces the amount of debugging
 168   information generated.
 169
 170 Changes in version 2.6:
 171
 172 * When an ELF section name is representable as a C identifier (this is not true
 173 of most ELF section names), the linker will automatically define symbols
 174 __start_SECNAME and __stop_SECNAME, where SECNAME is the section name, at the
 175 beginning and the end of the section.  This is used by glibc.
 176
 177 * When an ELF section named .gnu.warning is encountered in an input file, the
 178 contents of the section are displayed as an error message, and the section is
 179 not copied into the output file.  This is used by glibc.
 180
 181 * When an ELF section named .gnu.warning.SYMBOL is encountered in an input
 182 file, and the symbol SYMBOL is referenced by some object file, the contents of
 183 the section are displayed as an error message.  The section is not copied into
 184 the output file, unless doing a relocatable or shared link.  This is used by
 185 glibc.
 186
 187 * New options -split-by-reloc and -split-by-file.
 188
 189 * The linker now supports linking PIC compiled code on SPARC SunOS.  It can
 190 also create SPARC SunOS shared libraries, and, like the native SunOS linker,
 191 will do so whenever there is an undefined symbol in the link and neither the -e
 192 nor the -r option was used.
 193
 194 * The -rpath option may be used on SunOS to set the list of directories to be
 195 searched at run time.  This overrides the default of building the list from the
 196 -L options.
 197
 198 * The COFF linker now combines debugging information for structs, unions, and
 199 enums, so that even if the same type is defined in multiple input files it will
 200 only be defined once in the output file.  The --traditional-format switch will
 201 prevent this optimization.
 202
 203 Changes in version 2.5:
 204
 205 * The linker now supports linking against SunOS shared libraries.  It still can
 206 not link SunOS PIC (Position Independent Code) files, so it can not be used to
 207 generate shared libraries.
 208
 209 * The linker now supports linking against ELF shared libraries for the i386
 210 (UnixWare) and SPARC (Solaris).  It can also link ELF PIC files, and can be
 211 used to generate shared libraries.  Shared library generation is not well
 212 tested; please report any problems encountered.  The linker is now enabled for
 213 Solaris again.
 214
 215 * Eric Youngdale has contributed Linux support code, including linking against
 216 Linux a.out shared libraries.  The linker produces Linux QMAGIC binaries.
 217
 218 * The ELF backend has been converted to the new linker code.  To use the new
 219 ELF linker, each particular target requires a relocation function.  So far,
 220 this function has been written for i386 (UnixWare), SPARC (Solaris) MIPS (Irix
 221 5), and HPPA ELF targets.
 222
 223 * The -( (--start-group) and -) (--end-group) options have been added to
 224 support searching a group of archives as though they were a single archive.
 225 This can also be used in a linker script, as GROUP ( files ).
 226
 227 * When a file is named on the command line, and the linker does not recognize
 228 it as an object file, the linker will now treat the file as a linker script
 229 file.  A linker script named in this way augments, but does not replace, the
 230 default linker script.
 231
 232 * The -warn-once option was added.  It causes the linker to only warn once per
 233 undefined symbol, rather than once per reference.
 234
 235 * The COFF backend has been converted to the new linker code.  As with ELF, to
 236 use the new linker, each particular target requires a relocation function.  So
 237 far, this function has been written for the i386, m68k, a29k and SH targets.
 238
 239 * The -V flag was made a synonym for -v, for SVR4 compatibility.  The old -V
 240 behaviour is available via --verbose.
 241
 242 Changes in version 2.4:
 243
 244 * New linker code, by Steve Chamberlain and Ian Taylor.  For a.out and ecoff
 245   formats (so far), this should result in considerable savings in time
 246   and memory used while linking; slightly poorer performance than
 247   before for formats not converted yet.
 248
 249 * Command-line parsing is no longer done with flex.  This means
 250   oddball characters in filenames won't get treated as argument
 251   separators.
 252
 253 * HP-PA ELF support, by Jeff Law.  (No SOM support yet.)
 254
 255 * Mach i386 support, by David Mackenzie.
 256
 257 * Irix 4 shared libraries are now supported (Irix 5 uses ELF, and ELF shared
 258   libraries are not yet supported).
 259
 260 * COFF shared libraries (as on SCO) should work as well.
 261
 262 * The linker is disabled for Solaris.  (Actually, it was in 2.3 also, I just
 263   forgot to note it.)  Some of their C library routines don't work when
 264   statically linked, and the GNU linker doesn't support dynamic linking yet.
 265
 266 Changes in version 2.3:
 267
 268 * Weak symbols are now supported.
 269
 270 * ELF support has been added.  The linker has been bootstrapped on
 271   UnixWare and Solaris.
 272
 273 * Alpha OSF/1 support has been added (non dynamic linking only).
 274
 275 Changes in version 2.2:
 276
 277 * The `bfd' library has been updated to reduce a.out-format string
 278   table size.  The effect of this is that files linked from many input
 279   files with duplicate symbols (`-g' debugging records, or identical
 280   static symbols) should be much smaller.
 281
 282 Changes in version 2.1:
 283
 284 * The ld -ySYMBOL flag (to trace references to SYMBOL) is now implemented.
 285
 286 * There is now support for writing ECOFF files, so ld and the
 287   other utilities should work on Risc/Ultrix and Irix.
 288
 289 \f
 290 Local variables:
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 292 End: