ld/NEWS

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