ld/NEWS

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