ld/NEWS

   1 -*- text -*-
   2
   3 Changes in version 2.10:
   4
   5 * Added AT> to the linker script language to allow load-time allocation of
   6   sections into regions.
   7
   8 * Added garbage collection of unused sections, enabled by --gc-sections.
   9   It does require a bit of backend support; currently implemented are
  10   ppc-elf, mips-elf, and mn10300-elf.  Others will ignore the option.
  11
  12 * Added SORT to the linker script language to permit sorting sections by file
  13   name or section name.
  14
  15 * Added EXTERN to the linker script language as an equivalent to the -u
  16   command-line option.
  17
  18 * Added ASSERT to the linker script language.
  19
  20 * Added EXCLUDE_FILE to the linker script language for further control over
  21   wildcard file names.
  22
  23 * Added -O option to optimize linker output (as of this writing, this only
  24 affects ELF shared library generation).
  25
  26 * The -e option now accepts a number as well as a symbol name.
  27
  28 * Added --no-undefined option to disallow undefined symbols when creating a
  29   shared library.
  30
  31 * The linker now issues a warning, not an error, for an undefined symbol when
  32   using -Bsymbolic; use the new --no-undefined option to get the old
  33   behaviour.
  34
  35 * Added --demangle and --no-demangle options.
  36
  37 Changes in version 2.9:
  38
  39 * Added SQUAD to the linker script language.
  40
  41 * New option --no-warn-mismatch.
  42
  43 * The MEMORY command now parses the attributes to determine where sections that
  44   are not placed in a specific memory region are placed.
  45
  46 Changes in version 2.8:
  47
  48 * Linker scripts may now contain shell wildcard characters for file and section
  49   names.
  50
  51 * The linker now supports symbol versions in ELF.
  52
  53 * The NOCROSSREFS command was added to the linker script language.
  54
  55 * The LOADADDR expression was added to the linker script language.
  56
  57 * MAX and MIN functions were added to the linker script language.
  58
  59 * The OVERLAY construct was added to the linker script language.
  60
  61 * New option --warn-section-align to warn when the address of an output section
  62   changes due to alignment of an input section.
  63
  64 * New options --filter/-F and --auxiliary/-f.
  65
  66 Changes in version 2.7:
  67
  68 * New option --cref to print out a cross reference table.
  69
  70 * New option --wrap SYMBOL.
  71
  72 * New option --no-whole-archive, to turn off the effect of --whole-archive.
  73
  74 * Input sections assigned to the output section /DISCARD/ in the linker script
  75   are not included in the output file.
  76
  77 * The SunOS and ELF linkers now merge stabs debugging information which uses
  78   the N_BINCL and N_EINCL stab types.  This reduces the amount of debugging
  79   information generated.
  80
  81 Changes in version 2.6:
  82
  83 * When an ELF section name is representable as a C identifier (this is not true
  84 of most ELF section names), the linker will automatically define symbols
  85 __start_SECNAME and __stop_SECNAME, where SECNAME is the section name, at the
  86 beginning and the end of the section.  This is used by glibc.
  87
  88 * When an ELF section named .gnu.warning is encountered in an input file, the
  89 contents of the section are displayed as an error message, and the section is
  90 not copied into the output file.  This is used by glibc.
  91
  92 * When an ELF section named .gnu.warning.SYMBOL is encountered in an input
  93 file, and the symbol SYMBOL is referenced by some object file, the contents of
  94 the section are displayed as an error message.  The section is not copied into
  95 the output file, unless doing a relocateable or shared link.  This is used by
  96 glibc.
  97
  98 * New options -split-by-reloc and -split-by-file.
  99
 100 * The linker now supports linking PIC compiled code on SPARC SunOS.  It can
 101 also create SPARC SunOS shared libraries, and, like the native SunOS linker,
 102 will do so whenever there is an undefined symbol in the link and neither the -e
 103 nor the -r option was used.
 104
 105 * The -rpath option may be used on SunOS to set the list of directories to be
 106 searched at run time.  This overrides the default of building the list from the
 107 -L options.
 108
 109 * The COFF linker now combines debugging information for structs, unions, and
 110 enums, so that even if the same type is defined in multiple input files it will
 111 only be defined once in the output file.  The --traditional-format switch will
 112 prevent this optimization.
 113
 114 Changes in version 2.5:
 115
 116 * The linker now supports linking against SunOS shared libraries.  It still can
 117 not link SunOS PIC (Position Independent Code) files, so it can not be used to
 118 generate shared libaries.
 119
 120 * The linker now supports linking against ELF shared libraries for the i386
 121 (UnixWare) and SPARC (Solaris).  It can also link ELF PIC files, and can be
 122 used to generate shared libraries.  Shared library generation is not well
 123 tested; please report any problems encountered.  The linker is now enabled for
 124 Solaris again.
 125
 126 * Eric Youngdale has contributed Linux support code, including linking against
 127 Linux a.out shared libraries.  The linker produces Linux QMAGIC binaries.
 128
 129 * The ELF backend has been converted to the new linker code.  To use the new
 130 ELF linker, each particular target requires a relocation function.  So far,
 131 this function has been written for i386 (UnixWare), SPARC (Solaris) MIPS (Irix
 132 5), and HPPA ELF targets.
 133
 134 * The -( (--start-group) and -) (--end-group) options have been added to
 135 support searching a group of archives as though they were a single archive.
 136 This can also be used in a linker script, as GROUP ( files ).
 137
 138 * When a file is named on the command line, and the linker does not recognize
 139 it as an object file, the linker will now treat the file as a linker script
 140 file.  A linker script named in this way augments, but does not replace, the
 141 default linker script.
 142
 143 * The -warn-once option was added.  It causes the linker to only warn once per
 144 undefined symbol, rather than once per reference.
 145
 146 * The COFF backend has been converted to the new linker code.  As with ELF, to
 147 use the new linker, each particular target requires a relocation function.  So
 148 far, this function has been written for the i386, m68k, a29k and SH targets.
 149
 150 * The -V flag was made a synonym for -v, for SVR4 compatibility.  The old -V
 151 behaviour is available via --verbose.
 152
 153 Changes in version 2.4:
 154
 155 * New linker code, by Steve Chamberlain and Ian Taylor.  For a.out and ecoff
 156   formats (so far), this should result in considerable savings in time
 157   and memory used while linking; slightly poorer performance than
 158   before for formats not converted yet.
 159
 160 * Command-line parsing is no longer done with flex.  This means
 161   oddball characters in filenames won't get treated as argument
 162   separators.
 163
 164 * HP-PA ELF support, by Jeff Law.  (No SOM support yet.)
 165
 166 * Mach i386 support, by David Mackenzie.
 167
 168 * Irix 4 shared libraries are now supported (Irix 5 uses ELF, and ELF shared
 169   libraries are not yet supported).
 170
 171 * COFF shared libraries (as on SCO) should work as well.
 172
 173 * The linker is disabled for Solaris.  (Actually, it was in 2.3 also, I just
 174   forgot to note it.)  Some of their C library routines don't work when
 175   statically linked, and the GNU linker doesn't support dynamic linking yet.
 176
 177 Changes in version 2.3:
 178
 179 * Weak symbols are now supported.
 180
 181 * ELF support has been added.  The linker has been bootstrapped on
 182   UnixWare and Solaris.
 183
 184 * Alpha OSF/1 support has been added (non dynamic linking only).
 185
 186 Changes in version 2.2:
 187
 188 * The `bfd' library has been updated to reduce a.out-format string
 189   table size.  The effect of this is that files linked from many input
 190   files with duplicate symbols (`-g' debugging records, or identical
 191   static symbols) should be much smaller.
 192
 193 Changes in version 2.1:
 194
 195 * The ld -ySYMBOL flag (to trace references to SYMBOL) is now implemented.
 196
 197 * There is now support for writing ECOFF files, so ld and the
 198   other utilities should work on Risc/Ultrix and Irix.
 199
 200 \f
 201 Local variables:
 202 fill-column: 79
 203 End: