ld/NEWS

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