ld/NEWS

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