ld/NEWS

   1 -*- text -*-
   2
   3 * New PE --large-address-aware option to indicate executables support virtual
   4   addresses greater than 2 gigabytes.
   5
   6 * DWARF 2 support for i386pe added.
   7
   8 * The linker script operator DEFINED() will now yield 1 only for a symbol that
   9   is defined before the statement where DEFINED is used.
  10
  11 * The MIPS --embedded-relocs (used to embed relocations into binaries for
  12   Embedded-PIC code) is deprecated and will be removed in a future release.
  13
  14 * cr16c support added by NSC.
  15
  16 * m32r Linux (ELF) support added by Renesas.
  17
  18 * Improved linker's handling of unresolved symbols.  The switch
  19   --unresolved-symbols=<method> has been added to tell the linker when it
  20   should report them and the switch --warn-unresolved-symbols has been added to
  21   make reports be issued as warning messages rather than errors.
  22
  23 Changes in 2.14:
  24
  25 * Added support for Xtensa architecture.
  26
  27 * Added --with-sysroot configure switch to specify a target system root, for
  28   linking against a target filesystem image.
  29
  30 * Added --accept-unknown-linker-format to restore old linker behaviour (pre
  31   2.14) of silently accepting and linking in any files in an unknown binary
  32   file format.
  33
  34 * Added --no-omagic to undo the effects of the -N option.
  35
  36 * Support for Texas Instruments TMS320C4x and TMS320C3x series of
  37   DSP's contributed by Michael Hayes and Svein E. Seldal.
  38
  39 * Added --with-lib-path configure switch to specify default value for
  40   LIB_PATH.
  41
  42 * ARM port to QNX operating system added by Graeme Peterson.
  43
  44 * IP2K support added by Denis Chertykov.
  45
  46 Changes in 2.13:
  47
  48 * Support for the Fujitsu FRV architecture added by Red Hat. Models for FR400
  49   and FR500 included.
  50
  51 Changes in version 2.13:
  52
  53 * DEC VAX ELF support, by Matt Thomas.
  54
  55 Changes in version 2.12:
  56
  57 * Support for Don Knuth's MMIX, by Hans-Peter Nilsson.
  58
  59 * Support for the OpenRISC 32-bit embedded processor by OpenCores.
  60
  61 * Support for -z nocopyreloc in the x86 ELF linker, which disables
  62   production of copy relocs.  Warning: using this option may result in
  63   non-sharable applications.
  64
  65 * Support for -z combreloc in the ELF linker, which puts dynamic
  66   relocations against the same symbol together, so that dynamic linker
  67   can use an one-entry symbol lookup cache.
  68
  69 * Support for ELF SHF_MERGE section merging, by Jakub Jelinek.
  70
  71 Changes in version 2.11:
  72
  73 * Support for AMD x86-64 architecture, by Jan Hubicka, SuSE Labs.
  74
  75 * Support added for eliminating duplicate DWARF2 debug information by
  76   having the compiler generate the information in sections called
  77   .gnu.linkonce.wi.XXXX where XXXX is a checksum for the contents.  The
  78   linker then merges these sections together into the normal .debug_info
  79   section.
  80
  81 * The native ELF linker now searches the directories in DT_RUNPATH or
  82   DT_RPATH of a shared library for shared libraries needed by it.
  83
  84 * TI C54x support, by Timothy Wall.
  85
  86 * Added command line switch --section-start to set the start address of any
  87   specified section.
  88
  89 * Added ability to emit full relocation information in linked executables,
  90   enabled by --emit-relocs.  Some post-linkage optimization tools need
  91   this information in order to be able to correctly identify and perform
  92   symbol relative addressing in the event of changes in section contents
  93   (instructions being added or deleted, extending data sections, etc.)
  94
  95 * Support for i860, by Jason Eckhardt (preliminary, alpha quality).
  96
  97 * Support for CRIS (Axis Communications ETRAX series).
  98
  99 * Support for PDP-11 and 2.11BSD a.out format, by Lars Brinkhoff.
 100
 101 Changes in version 2.10:
 102
 103 * Added AT> to the linker script language to allow load-time allocation of
 104   sections into regions.
 105
 106 * Added garbage collection of unused sections, enabled by --gc-sections.
 107   It does require a bit of backend support; currently implemented are
 108   arm-elf, avr-elf, d10v-elf, fr30-elf, i386-elf, m32r-elf, m68k-elf,
 109   mcore-elf, mips-elf, mn10300-elf, ppc-elf, sh-elf, sparc-elf, and v850-elf.
 110   Others will ignore the option.
 111
 112 * Added SORT to the linker script language to permit sorting sections by file
 113   name or section name.
 114
 115 * Added EXTERN to the linker script language as an equivalent to the -u
 116   command-line option.
 117
 118 * Added ASSERT to the linker script language.
 119
 120 * Added EXCLUDE_FILE to the linker script language for further control over
 121   wildcard file names.
 122
 123 * Added -O option to optimize linker output (as of this writing, this only
 124   affects ELF shared library generation).
 125
 126 * The -e option now accepts a number as well as a symbol name.
 127
 128 * Added --no-undefined option to disallow undefined symbols when creating a
 129   shared library.
 130
 131 * The linker now issues a warning, not an error, for an undefined symbol when
 132   using -Bsymbolic; use the new --no-undefined option to get the old
 133   behaviour.
 134
 135 * Added --demangle and --no-demangle options.
 136
 137 Changes in version 2.9:
 138
 139 * Added SQUAD to the linker script language.
 140
 141 * New option --no-warn-mismatch.
 142
 143 * The MEMORY command now parses the attributes to determine where sections that
 144   are not placed in a specific memory region are placed.
 145
 146 Changes in version 2.8:
 147
 148 * Linker scripts may now contain shell wildcard characters for file and section
 149   names.
 150
 151 * The linker now supports symbol versions in ELF.
 152
 153 * The NOCROSSREFS command was added to the linker script language.
 154
 155 * The LOADADDR expression was added to the linker script language.
 156
 157 * MAX and MIN functions were added to the linker script language.
 158
 159 * The OVERLAY construct was added to the linker script language.
 160
 161 * New option --warn-section-align to warn when the address of an output section
 162   changes due to alignment of an input section.
 163
 164 * New options --filter/-F and --auxiliary/-f.
 165
 166 Changes in version 2.7:
 167
 168 * New option --cref to print out a cross reference table.
 169
 170 * New option --wrap SYMBOL.
 171
 172 * New option --no-whole-archive, to turn off the effect of --whole-archive.
 173
 174 * Input sections assigned to the output section /DISCARD/ in the linker script
 175   are not included in the output file.
 176
 177 * The SunOS and ELF linkers now merge stabs debugging information which uses
 178   the N_BINCL and N_EINCL stab types.  This reduces the amount of debugging
 179   information generated.
 180
 181 Changes in version 2.6:
 182
 183 * When an ELF section name is representable as a C identifier (this is not true
 184 of most ELF section names), the linker will automatically define symbols
 185 __start_SECNAME and __stop_SECNAME, where SECNAME is the section name, at the
 186 beginning and the end of the section.  This is used by glibc.
 187
 188 * When an ELF section named .gnu.warning is encountered in an input file, the
 189 contents of the section are displayed as an error message, and the section is
 190 not copied into the output file.  This is used by glibc.
 191
 192 * When an ELF section named .gnu.warning.SYMBOL is encountered in an input
 193 file, and the symbol SYMBOL is referenced by some object file, the contents of
 194 the section are displayed as an error message.  The section is not copied into
 195 the output file, unless doing a relocatable or shared link.  This is used by
 196 glibc.
 197
 198 * New options -split-by-reloc and -split-by-file.
 199
 200 * The linker now supports linking PIC compiled code on SPARC SunOS.  It can
 201 also create SPARC SunOS shared libraries, and, like the native SunOS linker,
 202 will do so whenever there is an undefined symbol in the link and neither the -e
 203 nor the -r option was used.
 204
 205 * The -rpath option may be used on SunOS to set the list of directories to be
 206 searched at run time.  This overrides the default of building the list from the
 207 -L options.
 208
 209 * The COFF linker now combines debugging information for structs, unions, and
 210 enums, so that even if the same type is defined in multiple input files it will
 211 only be defined once in the output file.  The --traditional-format switch will
 212 prevent this optimization.
 213
 214 Changes in version 2.5:
 215
 216 * The linker now supports linking against SunOS shared libraries.  It still can
 217 not link SunOS PIC (Position Independent Code) files, so it can not be used to
 218 generate shared libraries.
 219
 220 * The linker now supports linking against ELF shared libraries for the i386
 221 (UnixWare) and SPARC (Solaris).  It can also link ELF PIC files, and can be
 222 used to generate shared libraries.  Shared library generation is not well
 223 tested; please report any problems encountered.  The linker is now enabled for
 224 Solaris again.
 225
 226 * Eric Youngdale has contributed Linux support code, including linking against
 227 Linux a.out shared libraries.  The linker produces Linux QMAGIC binaries.
 228
 229 * The ELF backend has been converted to the new linker code.  To use the new
 230 ELF linker, each particular target requires a relocation function.  So far,
 231 this function has been written for i386 (UnixWare), SPARC (Solaris) MIPS (Irix
 232 5), and HPPA ELF targets.
 233
 234 * The -( (--start-group) and -) (--end-group) options have been added to
 235 support searching a group of archives as though they were a single archive.
 236 This can also be used in a linker script, as GROUP ( files ).
 237
 238 * When a file is named on the command line, and the linker does not recognize
 239 it as an object file, the linker will now treat the file as a linker script
 240 file.  A linker script named in this way augments, but does not replace, the
 241 default linker script.
 242
 243 * The -warn-once option was added.  It causes the linker to only warn once per
 244 undefined symbol, rather than once per reference.
 245
 246 * The COFF backend has been converted to the new linker code.  As with ELF, to
 247 use the new linker, each particular target requires a relocation function.  So
 248 far, this function has been written for the i386, m68k, a29k and SH targets.
 249
 250 * The -V flag was made a synonym for -v, for SVR4 compatibility.  The old -V
 251 behaviour is available via --verbose.
 252
 253 Changes in version 2.4:
 254
 255 * New linker code, by Steve Chamberlain and Ian Taylor.  For a.out and ecoff
 256   formats (so far), this should result in considerable savings in time
 257   and memory used while linking; slightly poorer performance than
 258   before for formats not converted yet.
 259
 260 * Command-line parsing is no longer done with flex.  This means
 261   oddball characters in filenames won't get treated as argument
 262   separators.
 263
 264 * HP-PA ELF support, by Jeff Law.  (No SOM support yet.)
 265
 266 * Mach i386 support, by David Mackenzie.
 267
 268 * Irix 4 shared libraries are now supported (Irix 5 uses ELF, and ELF shared
 269   libraries are not yet supported).
 270
 271 * COFF shared libraries (as on SCO) should work as well.
 272
 273 * The linker is disabled for Solaris.  (Actually, it was in 2.3 also, I just
 274   forgot to note it.)  Some of their C library routines don't work when
 275   statically linked, and the GNU linker doesn't support dynamic linking yet.
 276
 277 Changes in version 2.3:
 278
 279 * Weak symbols are now supported.
 280
 281 * ELF support has been added.  The linker has been bootstrapped on
 282   UnixWare and Solaris.
 283
 284 * Alpha OSF/1 support has been added (non dynamic linking only).
 285
 286 Changes in version 2.2:
 287
 288 * The `bfd' library has been updated to reduce a.out-format string
 289   table size.  The effect of this is that files linked from many input
 290   files with duplicate symbols (`-g' debugging records, or identical
 291   static symbols) should be much smaller.
 292
 293 Changes in version 2.1:
 294
 295 * The ld -ySYMBOL flag (to trace references to SYMBOL) is now implemented.
 296
 297 * There is now support for writing ECOFF files, so ld and the
 298   other utilities should work on Risc/Ultrix and Irix.
 299
 300 \f
 301 Local variables:
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 303 End: