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Mail Archives: djgpp/2018/03/04/12:17:55

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Message-Id: <201803041717.w24HHron032489@delorie.com>
Date: Sun, 04 Mar 2018 14:40:06 +0100
From: "Juan Manuel Guerrero (juan DOT guerrero AT gmx DOT de) [via djgpp-announce AT delorie DOT com]" <djgpp-announce AT delorie DOT com>
To: djgpp-announce AT delorie DOT com
Subject: ANNOUNCE: DJGPP port of GNU binutils 2.30 uploaded.
Reply-To: djgpp AT delorie DOT com

This is a port of GNU binutils 2.30 to MSDOS/DJGPP.

   The GNU binutils are utilities of use when dealing with binary files,
   either object files or executables.  These tools consist of the linker
   (ld), the assembler (gas), and the profiler (gprof).  There is also a
   collection of other binary tools, including the disassembler (objdump).
   These tools make use of a pair of libraries (bfd and opcodes) and a
   common set of header files.



   DJGPP specific changes.
   =======================
   - There are no DJGPP specific changes compared with the previous port.
     The DJGPP specific changes enumerated below are the same than the ones
     already available in the previous port.

   - This port allows a maximal number of 4294967296 relocations per object
     file and a maximal number of 4294967296 of lines per executable file.
     The previous limits were the classical COFF limitations of 65536 for
     boths.  Please note, that due to limitations inherent to DOS and memory
     ressources not every file can be compiled.  E.g.: to be able to compile
     a single file containing up to 3 * 65536 relocations I had to increment
     stack space of cc1.exe from 2MB to 10MB.  If the file contains 4 * 65536
     relocations then cc1.exe aborts because memory has become exhausted.
     Neither as.exe nor ld.exe have shown memory issues.  Both have the
     standard stack space of 512KB.  In other words, even if 32 bit values
     for relocation and line counters are now supported by DJGPP port of
     as.exe and ld.exe it does not imply that large files can be successfully
     compiled and linked.  There are memory limitations that may not be
     solvable.  OFYI how the DJGPP specifc support for number of relocations
     greater than 64K works:
      - If the number of relocations of an object file exceeds 65534 then
        s_nreloc in the section header is set to 65535 to signal the overflow
        and the real number of relocations is stored in an extra COFF relocation
        directive.  This is always the first relocation directive in the sequence
        of relocation directives of this object file.  The 32 bit field r_vaddr
        is used to store the real number of relocations.  This extra relocation
        directive is later removed.  To signal this overflow also the
        STYP_NRELOC_OVFL bit (0x01000000) is set in the s_flags field of the
        section header.
      - If the number of lines of an object file exceeds 65535 then the assembler
        will abort with an error message.  This can only happen if COFF debug info
        is used.  There is no work around for this issue.
      - When the linker creates an executable file from the objects files and
        the total number of lines exceeds 65535 the lower 16 bit of that value
        will be stored in the s_nlnno field and the higher 16 bit in the s_nreloc
        field of the section header of the executable file.  This can only happen
        if COFF debug info is used.

   - The support of more than 64k relocations can be disable by defining the
     DISABLE_64K_RELOC_SUPPORT environment variable to either y or Y.  Any
     other value is ignored and automatically enables the greather than 64k
     relocations support.  The same applies if the variable is not defined at
     all.  This is true for all applications linked with libbfd.a if and only
     if they call the bfd_init function that will check for this environment
     variable.  If this is not done the support is always enabled.  All this
     means that the enabled support is always the default.

   - The linker script changes, are based on the diff files taken from Andris
     Pavenis' bnu219s2.zip and djcross-binutils-2.19.1-10ap.src.rpm.  Both are
     available at ftp.delorie.com and mirrors.
     I have only made those adjustments necessaries to get those patches fit
     with the current source files.

   - The diffs file that contains all changes I have done is stored in the
     /djgpp directory.  Also in this directory is stored the small build.sh
     script that I have used to adjust all configure and libtool scripts of
     the package.  The well known issues that must been fixed are that:
     1) the gawk test for setting the CR coding to be used does not work at
        all.
     2) inhibit that gawk prepends a leading slash to DOS style path names.
     3) a libtool function needs to be adjusted to get the install target
        working.
     4) the target alias is removed from the tooldir and scriptdir path to
        get the programs and linker scripts installed in the canonical places
        of a DJGPP installation.
     That script is very simple and will only work to configure and compile
     the sources in the /djgpp directory.  If you want to make changes or pass
     more or other options to configure, you will have to edit it or write your
     own script.  build.sh shall not be smart, it shall only DTRT.

   - The linker script has been adapted to discard LTO sections created by the
     compiler if the -flto flag is passed to the compiler.  This is due to LTO
     specific file names that are not 8.3 clean especially if the -save-temps
     option is used.  This may change in the future when the djgpp port of the
     compiler fully supports LTO.  A syntax error concerning the i386go32.xr
     and i386go32.xu build-in linker scripts has also been fixed.

   - This port provides a version of the linker that will be capable to resolve
     multiple symbol definitions conflicts when using DXE3 modules.  Multiple
     symbol definition always occure when an application is linked with various
     libraries and more than one of its provides an object file defining the
     same function (symbol).  E.g.: when compiling an arbitrary GNU source
     package like grep with NLS enabled and using the DXE3 module versions of
     the iconv library and the gettext library, a definition of the locale_charset
     function (aka symbol) will appear three times.  One definition (aka
     function implementation) will be provided by the grep code itself via its
     own code (aka libgreputils.a).  The other two will be provided by the import
     libraries libiconv.a and libintl.a of both DXE3 modules used.  The linker
     will note that the different libraries provide different implementations of
     the same function and will abort operation with an error message like this:

c:/djgpp-2.04/lib/libintl.a(dxe_tmp.o):dxe_tmp.c:(.text+0x7a4): multiple definition of `locale_charset'
../lib/libgreputils.a(localcharset.o):h:/g/srcs/gnu/grep-2.18/_build.204/lib/.././../lib/localcharset.c:363: first defined here
c:/djgpp-2.04/lib/libiconv.a(dxe_tmp.o):dxe_tmp.c:(.text+0x248): multiple definition of `locale_charset'
../lib/libgreputils.a(localcharset.o):h:/g/srcs/gnu/grep-2.18/_build.204/lib/.././../lib/localcharset.c:363: first defined here
collect2.exe: error: ld returned 1 exit status

     In case of multiple symbol definitions, the linker will check if one of
     the definitions comes from an import library (all import libraries contain
     only one single object file called either dxe_tmp.o or $$dxe$$.o).
     If the symbol definition is stored in a file called dxe_tmp.o, all other
     definitions will be ignored/discarded.  This means that the symbol
     definition of the DXE3 module has __always__ precedence over any other
     symbol definition.  This will guarantee that all compiled programs that
     use the same DXE3 module will use at runtime the same implementation of
     the required function and not a particular implementation provided by the
     sources of the program being compiled.  That implementation may not even
     have been ported to djgpp and thus will be useless at all.  There is no
     linker switch to change this behaviour and to give any other function
     implementation precedence over the DXE3 implementation.  If more than one
     import library provides a definition for the same symbol, always the first
     is used and all other import library definitions are ignored.  This is not
     an issue because the import libraries only provide wrapper functions that
     call at runtime the real functions stored in the DXE3 modules and these
     wrapper functions look all the same.  Without this capability, the DXE3
     modules become almost useless for NLS support, because the porter of every
     package that has NLS enabled would have to take care to remove all NLS
     specific functions from the port code that are already provided either by
     the gettext library or by the iconv library.  Please note that the linker
     cannot resolve any other multiple symbol definition conflict than the one
     described for the DXE3 modules.  Of course, if static library versions of
     those NLS libraries are used, these symbol conflicts do not arise at all
     and the linker creates an executable in the usual way.  To be able to
     compile the linker with this feature you must uncomment the line that
     defines the DXE3_SUPPORT_ENABLED variable in the /djgpp/build.sh file.

   - There are ports like the one of GNU gettext that provide libraries with
     file names that cannot be uniquely mapped to short file names without
     using numeric tails.  Usualy in this case the files are renamed so they
     have a valid short file name without having to use numeric tails.  The
     consecuence of this renaming is that a lot of Makefiles need to be
     adjusted in a DJGPP/DOS specific way.  To avoid this inconvenience, this
     version of the linker will provide a mapping feature between the original
     long file names and the DOS specific short file names.  This port provides
     a new file called libnames.tab located in /dev/env/DJDIR/lib.  When the
     linker tries to open a library with its original name and failes, it will
     try to open /dev/env/DJDIR/lib/libnames.tab and load it content into a
     static array/table.  With the aid of this table it will try to map the
     long file name to a short file name.  If this mapping is succesfull it
     will try to load that file instead of the original one and if this was
     also succesfull it will continue working.  For every other library that
     cannot be loaded by its original name, the linker will search for an
     alternative name in the array/table and load that library instead.  Please
     note that you cannot specific the location of libnames.tab.  If required,
     the linker will load it from the canonical location and there will be no
     error message if libnames.tab cannot be found or loaded.  If the linker
     cannot load the library neither by its original name nor by its short
     name it will abort the operation in the usual way and issue an error
     message about file loading error printing the original file name.
     The syntax for the entries is quite simple and the scanning/reading of
     the file is not bullet-proof.  This means that syntax errors will not be
     detected and will produce nonsense file name translations that will very
     likely make abort the linker.  I do not think that this is a great
     inconvenience because most of the users should never add any entry to
     this file.  It is the job of the port of some package that must provide
     an update of libnames.tab if his port contains renamed libraries.
     Syntax of libnames.tab entries:
     1) The # character defines comment line that will be skipped.
        The comment is the complete line and NOT only the text following the
        # character!
     2) Empty lines will be skipped.
     3) A valid entry looks like:

withverylongname-1.2   wvln12

        Neither the prefix nor the suffix/extension of the library name is
        part of the table entry.  For the above example the complete file
        name of the library would be:
          libwithverylongname-1.2.a
        To get a valid entry strip the prefix "lib" and the suffix ".a" from
        the library name.  The same applies to the short file name of the
        library.  In the example above, the library has been renamed to:
          libwvln12.a
        and that is the file name of the library that the linker will use.
        The original file name is always the first name and the substitute
        file name is the second name.  Both names are separated by at least
        one space or tab character.
        Another example:  the gettext port provides a library that has been
        renamed to libgtxtsrc.a.  Its original name was libgettextsrc.a.
        The entry for this library looks like this:

gettextsrc     gtxtsrc

        As can be seen the "lib" prefix and the ".a" suffix have been stripped
        from both library names to get the table entry.  In the actual version
        of libnames.tab there are only the three entries for the three renamed
        libraries provided by the gettext port.

   - For performance reasons, BFD tries to open and cache certain amount of
     files and its contents.  How many files can be opened is determinated at
     program start using the getrlimit function.  Unfortunately this function
     seems to be a placebo function.  At least when using djdev204 on WinXP,
     this function always returns the hard coded value of 255.  This is the
     value for the number of files that can be opened (RLIMIT_NOFILE).  BFD
     takes one eight of this value but at least 10 and opens so mutch files
     as required.  If your FILES entry in config.sys is not large enough (at
     least around 35) then the program aborts.  The corresponding BFD function
     now assumes that there are at least 16 available and will use all of them
     if required.  This has the consequence that the user must set his FILES
     entry in config.sys or config.nt to 20 or 25.  The value depends on how
     much file handles the OS and the DPMI server has already consumed for its
     on needs.

   - The diffs file stored in the /djgpp directory documents the DJGPP specific
     changes.  It has been splitt into three different files.  diffs-bfd
     contains all DJGPP specific changes to libbfd and libiberty.  These changes
     are shared with the DJGPP port of gdb.  The diffs file contains all DJGPP
     specific changes for the rest of binutils.  The diffs-bugs file contain
     those DJGPP specific changes to fix bugs discovered during porting of
     binutils.  If these changes are accepted by the binutils maintainers or
     the bug is fixed in some other way then this file will be removed for the
     next port release.  All these files are located in the /djgpp directory.
     If you want to apply them to the original sources, diffs and diffs-bfd
     must be apllied first (in any order) and diffs-bugs always as last one.
     The elf support has proven not to work so it no longer provided at all.

   - The port has been configured and compiled on WinXP SP3 and on Win98SE.
     There is no guarantee that this may be possible with any other DOS-like
     OS.  Due to the massive use of long file names it will not be possible
     to configure and compile without LFN support.  The port has been compiled
     using gcc346b and bnu230b.

   - The port has been tested by using it.  I have used them only on WinXP.
     It has worked flawlessly.  I do not konw if this will ever be the case on
     FreeDOS.  I have never used/tested them in that environment.



   As usual, all djgpp specific files (build.sh, diffs, README files, etc.)
   are stored in the /djgpp directory.  The sources have not been configured
   so you must change into the /djgpp directory and start build.sh.  This will
   configure the sources and start make.

   For further information about Binutils please read the info docs and NEWS
   file.




   The port consists of the usual four packages that have been produced
   using djdev205 and can be downloaded from ftp.delorie.com and mirrors
   as (time stamp 2018-02-17):

     Binutils 2.30 binary and info format documentation:
     ftp://ftp.delorie.com/pub/djgpp/current/v2gnu/bnu230b.zip

     Binutils 2.30 bfd, liberty and opcode libraries and headers:
     ftp://ftp.delorie.com/pub/djgpp/current/v2gnu/bnu230a.zip

     Binutils 2.30 dvi, html, ps and pdf format documentation:
     ftp://ftp.delorie.com/pub/djgpp/current/v2gnu/bnu230d.zip

     Binutils 2.30 source:
     ftp://ftp.delorie.com/pub/djgpp/current/v2gnu/bnu230s.zip


   Send binutils specific bug reports to <bug-binutils AT gnu DOT org>.
   Send suggestions and bug reports concerning the DJGPP port to
   comp.os.msdos.djgpp or <djgpp AT delorie DOT com>.


Enjoy.

         Guerrero, Juan Manuel <juan DOT guerrero AT gmx DOT de>

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