1: -*- text -*-
    2: Changes in 2.18:
    3: 
    4: * Linker sources now released under version 3 of the GNU General Public
    5:   License.
    6: 
    7: * ELF: New --build-id option to generate a unique per-binary identifier
    8:   embedded in a note section.
    9: 
   10: * Added support for National Semicondutor CompactRISC (ie CR16) target.
   11: 
   12: * -l:foo now searches the library path for a filename called foo,
   13:   without converting it to libfoo.a or libfoo.so.
   14: 
   15: * Add a new command line option '--default-script=FILE' or '-dT FILE'
   16:   which specifies a replacement for the built in, default linker
   17:   script.
   18: 
   19: * ELF: Add -Bsymbolic-functions, --dynamic-list-cpp-new, which puts C++
   20:   operator new and delete on the dynamic list, and --dynamic-list-data,
   21:   builtin list for --dynamic-list, which puts global data symbols on the
   22:   dynamic list.
   23: 
   24: * Add support for x86_64 PE+ target.
   25: 
   26: * Add support for Score target.
   27: 
   28: * ELF: Add --dynamic-list option to specify a list of global symbols
   29:   whose references shouldn't be bound to the definition within the
   30:   shared library, or a list of symbols which should be added to the
   31:   symbol table in the executable.
   32: 
   33: * The default output section LMA has changed for allocatable sections from
   34:   being equal to VMA, to keeping the difference between LMA and VMA the same as
   35:   the previous output section in the same region.  This is a more useful
   36:   default when using overlays and other cases where you specify an LMA
   37:   differing from the VMA for some sections.
   38: 
   39: * New switch: --print-gc-sections to list any sections removed by garabge
   40:   collection.
   41: 
   42: * ARM: Added --vfp11-denorm-fix option to work around an erratum in current
   43:   VFP11 coprocessors.
   44: 
   45: Changes in 2.17:
   46: 
   47: * Support for the Infineon XC16X has been added by KPIT Cummins Infosystems.
   48: 
   49: * Modify the Linux linker search order to better match ld.so search order.
   50:   Look for DT_NEEDED libraries in paths specified by ld.so.conf before
   51:   searching the default directories, rather than vice versa.
   52:   Use $prefix/etc/ld.so.conf if it exists, otherwise /etc/ld.so.conf.
   53: 
   54: * PE-COFF: Forward exports from DLL's can now be specified in .def files
   55:   passed directly to ld.
   56: 
   57: * Support for the Z80 processor family has been added.
   58: 
   59: * Add support for the "@<file>" syntax to the command line, so that extra
   60:   switches can be read from <file>.
   61: 
   62: Changes in 2.16:
   63: 
   64: * Support for the R_ARM_V4BX relocation as defined in the ARM AAELF
   65:   specification has been added via the --fix-v4bx command-line option.
   66: 
   67: * New linker script construct AS_NEEDED(), which sets the --as-needed flag
   68:   for input files listed inside of it.
   69: 
   70: * A new command-line option, --sysroot, can be used to override the
   71:   default sysroot location.  It only applies to toolchains that were
   72:   configured using --with-sysroot.
   73: 
   74: * New linker script functions: ORIGIN() and LENGTH() which return information
   75:   about a specified memory region.
   76: 
   77: * Port to MAXQ processor contributed by HCL Tech.
   78: 
   79: * Added SEGMENT_START to the linker script language to permit the user to
   80:   override the base address for a segment from the command-line.
   81: 
   82: * ELF: --warn-shared-textrel option to warn if adding a DT_TEXTREL to a shared
   83:   object.
   84: 
   85: * Added SORT_BY_NAME and SORT_BY_ALIGNMENT to the linker script
   86:   language to permit sorting sections by section name or section
   87:   maximum alignment.
   88: 
   89: * Added a new linker command line switch, --sort-section name|alignment,
   90:   to sort sections by section name or maximum alignment.
   91: 
   92: * ELF: --add-needed/--no-add-needed options to control if a DT_NEEDED tag
   93:   should be added when a shared library comes from DT_NEEDED tags.
   94: 
   95: * Support for the crx-elf target added.
   96: 
   97: * Support for the sh-symbianelf target added.
   98: 
   99: * A new linker command line switch has been added which allows the hash table
  100:   size to be set to a suitable prime value near to its argument.  This switch
  101:   is --hash-size=<NUMBER>.  Also if the switch --reduce-memory-overheads is
  102:   used, and --hash-size has not been used, then the default value will be set
  103:   to 1021.
  104: 
  105: * Linker map files are now generated with an O(N) algorithm for finding symbols
  106:   that are defined in each section.  This uses about 40% more memory for
  107:   symbols than the old O(N^2) algorithm.  You can use the new
  108:   --reduce-memory-overheads option to select the old algorithm; this option
  109:   might also be used in the future to select similar tradeoffs.
  110: 
  111: Changes in 2.15:
  112: 
  113: * ELF: --as-needed/--no-as-needed options to control if a DT_NEEDED tag should
  114:   be added only when a shared library is referenced.
  115: 
  116: * PE: --large-address-aware option to indicate executables support virtual
  117:   addresses greater than 2 gigabytes.
  118: 
  119: * DWARF 2 support for i386pe added.
  120: 
  121: * The linker script operator DEFINED() will now yield 1 only for a symbol that
  122:   is defined before the statement where DEFINED is used.
  123: 
  124: * The MIPS --embedded-relocs (used to embed relocations into binaries for
  125:   Embedded-PIC code) is deprecated and will be removed in a future release.
  126: 
  127: * cr16c support added by NSC.
  128: 
  129: * m32r Linux (ELF) support added by Renesas.
  130: 
  131: * Improved linker's handling of unresolved symbols.  The switch
  132:   --unresolved-symbols=<method> has been added to tell the linker when it
  133:   should report them and the switch --warn-unresolved-symbols has been added to
  134:   make reports be issued as warning messages rather than errors.
  135: 
  136: Changes in 2.14:
  137: 
  138: * Added support for Xtensa architecture.
  139: 
  140: * Added --with-sysroot configure switch to specify a target system root, for
  141:   linking against a target filesystem image.
  142: 
  143: * Added --accept-unknown-linker-format to restore old linker behaviour (pre
  144:   2.14) of silently accepting and linking in any files in an unknown binary
  145:   file format.
  146: 
  147: * Added --no-omagic to undo the effects of the -N option.
  148: 
  149: * Support for Texas Instruments TMS320C4x and TMS320C3x series of
  150:   DSP's contributed by Michael Hayes and Svein E. Seldal.
  151: 
  152: * Added --with-lib-path configure switch to specify default value for
  153:   LIB_PATH.
  154: 
  155: * ARM port to QNX operating system added by Graeme Peterson.
  156: 
  157: * IP2K support added by Denis Chertykov.
  158: 
  159: Changes in 2.13:
  160: 
  161: * Support for the Fujitsu FRV architecture added by Red Hat. Models for FR400
  162:   and FR500 included.
  163: 
  164: Changes in version 2.13:
  165: 
  166: * DEC VAX ELF support, by Matt Thomas.
  167: 
  168: Changes in version 2.12:
  169: 
  170: * Support for Don Knuth's MMIX, by Hans-Peter Nilsson.
  171: 
  172: * Support for the OpenRISC 32-bit embedded processor by OpenCores.
  173: 
  174: * Support for -z nocopyreloc in the x86 ELF linker, which disables
  175:   production of copy relocs.  Warning: using this option may result in
  176:   non-sharable applications.
  177: 
  178: * Support for -z combreloc in the ELF linker, which puts dynamic
  179:   relocations against the same symbol together, so that dynamic linker
  180:   can use an one-entry symbol lookup cache.
  181: 
  182: * Support for ELF SHF_MERGE section merging, by Jakub Jelinek.
  183: 
  184: Changes in version 2.11:
  185: 
  186: * Support for AMD x86-64 architecture, by Jan Hubicka, SuSE Labs.
  187: 
  188: * Support added for eliminating duplicate DWARF2 debug information by
  189:   having the compiler generate the information in sections called
  190:   .gnu.linkonce.wi.XXXX where XXXX is a checksum for the contents.  The
  191:   linker then merges these sections together into the normal .debug_info
  192:   section.
  193: 
  194: * The native ELF linker now searches the directories in DT_RUNPATH or
  195:   DT_RPATH of a shared library for shared libraries needed by it.
  196: 
  197: * TI C54x support, by Timothy Wall.
  198: 
  199: * Added command line switch --section-start to set the start address of any
  200:   specified section.
  201: 
  202: * Added ability to emit full relocation information in linked executables,
  203:   enabled by --emit-relocs.  Some post-linkage optimization tools need
  204:   this information in order to be able to correctly identify and perform
  205:   symbol relative addressing in the event of changes in section contents
  206:   (instructions being added or deleted, extending data sections, etc.)
  207: 
  208: * Support for i860, by Jason Eckhardt (preliminary, alpha quality).
  209: 
  210: * Support for CRIS (Axis Communications ETRAX series).
  211: 
  212: * Support for PDP-11 and 2.11BSD a.out format, by Lars Brinkhoff.
  213: 
  214: Changes in version 2.10:
  215: 
  216: * Added AT> to the linker script language to allow load-time allocation of
  217:   sections into regions.
  218: 
  219: * Added garbage collection of unused sections, enabled by --gc-sections.
  220:   It does require a bit of backend support; currently implemented are
  221:   arm-elf, avr-elf, d10v-elf, fr30-elf, i386-elf, m32r-elf, m68k-elf,
  222:   mcore-elf, mips-elf, mn10300-elf, ppc-elf, sh-elf, sparc-elf, and v850-elf.
  223:   Others will ignore the option.
  224: 
  225: * Added SORT to the linker script language to permit sorting sections by file
  226:   name or section name.
  227: 
  228: * Added EXTERN to the linker script language as an equivalent to the -u
  229:   command-line option.
  230: 
  231: * Added ASSERT to the linker script language.
  232: 
  233: * Added EXCLUDE_FILE to the linker script language for further control over
  234:   wildcard file names.
  235: 
  236: * Added -O option to optimize linker output (as of this writing, this only
  237:   affects ELF shared library generation).
  238: 
  239: * The -e option now accepts a number as well as a symbol name.
  240: 
  241: * Added --no-undefined option to disallow undefined symbols when creating a
  242:   shared library.
  243: 
  244: * The linker now issues a warning, not an error, for an undefined symbol when
  245:   using -Bsymbolic; use the new --no-undefined option to get the old
  246:   behaviour.
  247: 
  248: * Added --demangle and --no-demangle options.
  249: 
  250: Changes in version 2.9:
  251: 
  252: * Added SQUAD to the linker script language.
  253: 
  254: * New option --no-warn-mismatch.
  255: 
  256: * The MEMORY command now parses the attributes to determine where sections that
  257:   are not placed in a specific memory region are placed.
  258: 
  259: Changes in version 2.8:
  260: 
  261: * Linker scripts may now contain shell wildcard characters for file and section
  262:   names.
  263: 
  264: * The linker now supports symbol versions in ELF.
  265: 
  266: * The NOCROSSREFS command was added to the linker script language.
  267: 
  268: * The LOADADDR expression was added to the linker script language.
  269: 
  270: * MAX and MIN functions were added to the linker script language.
  271: 
  272: * The OVERLAY construct was added to the linker script language.
  273: 
  274: * New option --warn-section-align to warn when the address of an output section
  275:   changes due to alignment of an input section.
  276: 
  277: * New options --filter/-F and --auxiliary/-f.
  278: 
  279: Changes in version 2.7:
  280: 
  281: * New option --cref to print out a cross reference table.
  282: 
  283: * New option --wrap SYMBOL.
  284: 
  285: * New option --no-whole-archive, to turn off the effect of --whole-archive.
  286: 
  287: * Input sections assigned to the output section /DISCARD/ in the linker script
  288:   are not included in the output file.
  289: 
  290: * The SunOS and ELF linkers now merge stabs debugging information which uses
  291:   the N_BINCL and N_EINCL stab types.  This reduces the amount of debugging
  292:   information generated.
  293: 
  294: Changes in version 2.6:
  295: 
  296: * When an ELF section name is representable as a C identifier (this is not true
  297: of most ELF section names), the linker will automatically define symbols
  298: __start_SECNAME and __stop_SECNAME, where SECNAME is the section name, at the
  299: beginning and the end of the section.  This is used by glibc.
  300: 
  301: * When an ELF section named .gnu.warning is encountered in an input file, the
  302: contents of the section are displayed as an error message, and the section is
  303: not copied into the output file.  This is used by glibc.
  304: 
  305: * When an ELF section named .gnu.warning.SYMBOL is encountered in an input
  306: file, and the symbol SYMBOL is referenced by some object file, the contents of
  307: the section are displayed as an error message.  The section is not copied into
  308: the output file, unless doing a relocatable or shared link.  This is used by
  309: glibc.
  310: 
  311: * New options -split-by-reloc and -split-by-file.
  312: 
  313: * The linker now supports linking PIC compiled code on SPARC SunOS.  It can
  314: also create SPARC SunOS shared libraries, and, like the native SunOS linker,
  315: will do so whenever there is an undefined symbol in the link and neither the -e
  316: nor the -r option was used.
  317: 
  318: * The -rpath option may be used on SunOS to set the list of directories to be
  319: searched at run time.  This overrides the default of building the list from the
  320: -L options.
  321: 
  322: * The COFF linker now combines debugging information for structs, unions, and
  323: enums, so that even if the same type is defined in multiple input files it will
  324: only be defined once in the output file.  The --traditional-format switch will
  325: prevent this optimization.
  326: 
  327: Changes in version 2.5:
  328: 
  329: * The linker now supports linking against SunOS shared libraries.  It still can
  330: not link SunOS PIC (Position Independent Code) files, so it can not be used to
  331: generate shared libraries.
  332: 
  333: * The linker now supports linking against ELF shared libraries for the i386
  334: (UnixWare) and SPARC (Solaris).  It can also link ELF PIC files, and can be
  335: used to generate shared libraries.  Shared library generation is not well
  336: tested; please report any problems encountered.  The linker is now enabled for
  337: Solaris again.
  338: 
  339: * Eric Youngdale has contributed Linux support code, including linking against
  340: Linux a.out shared libraries.  The linker produces Linux QMAGIC binaries.
  341: 
  342: * The ELF backend has been converted to the new linker code.  To use the new
  343: ELF linker, each particular target requires a relocation function.  So far,
  344: this function has been written for i386 (UnixWare), SPARC (Solaris) MIPS (Irix
  345: 5), and HPPA ELF targets.
  346: 
  347: * The -( (--start-group) and -) (--end-group) options have been added to
  348: support searching a group of archives as though they were a single archive.
  349: This can also be used in a linker script, as GROUP ( files ).
  350: 
  351: * When a file is named on the command line, and the linker does not recognize
  352: it as an object file, the linker will now treat the file as a linker script
  353: file.  A linker script named in this way augments, but does not replace, the
  354: default linker script.
  355: 
  356: * The -warn-once option was added.  It causes the linker to only warn once per
  357: undefined symbol, rather than once per reference.
  358: 
  359: * The COFF backend has been converted to the new linker code.  As with ELF, to
  360: use the new linker, each particular target requires a relocation function.  So
  361: far, this function has been written for the i386, m68k, a29k and SH targets.
  362: 
  363: * The -V flag was made a synonym for -v, for SVR4 compatibility.  The old -V
  364: behaviour is available via --verbose.
  365: 
  366: Changes in version 2.4:
  367: 
  368: * New linker code, by Steve Chamberlain and Ian Taylor.  For a.out and ecoff
  369:   formats (so far), this should result in considerable savings in time
  370:   and memory used while linking; slightly poorer performance than
  371:   before for formats not converted yet.
  372: 
  373: * Command-line parsing is no longer done with flex.  This means
  374:   oddball characters in filenames won't get treated as argument
  375:   separators.
  376: 
  377: * HP-PA ELF support, by Jeff Law.  (No SOM support yet.)
  378: 
  379: * Mach i386 support, by David Mackenzie.
  380: 
  381: * Irix 4 shared libraries are now supported (Irix 5 uses ELF, and ELF shared
  382:   libraries are not yet supported).
  383: 
  384: * COFF shared libraries (as on SCO) should work as well.
  385: 
  386: * The linker is disabled for Solaris.  (Actually, it was in 2.3 also, I just
  387:   forgot to note it.)  Some of their C library routines don't work when
  388:   statically linked, and the GNU linker doesn't support dynamic linking yet.
  389: 
  390: Changes in version 2.3:
  391: 
  392: * Weak symbols are now supported.
  393: 
  394: * ELF support has been added.  The linker has been bootstrapped on
  395:   UnixWare and Solaris.
  396: 
  397: * Alpha OSF/1 support has been added (non dynamic linking only).
  398: 
  399: Changes in version 2.2:
  400: 
  401: * The `bfd' library has been updated to reduce a.out-format string
  402:   table size.  The effect of this is that files linked from many input
  403:   files with duplicate symbols (`-g' debugging records, or identical
  404:   static symbols) should be much smaller.
  405: 
  406: Changes in version 2.1:
  407: 
  408: * The ld -ySYMBOL flag (to trace references to SYMBOL) is now implemented.
  409: 
  410: * There is now support for writing ECOFF files, so ld and the
  411:   other utilities should work on Risc/Ultrix and Irix.
  412: 
  413: ^L
  414: Local variables:
  415: fill-column: 79
  416: End: