ld/NEWS

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