ld/NEWS

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