This is a port of GNU Bison 1.875 to MSDOS/DJGPP.


1.:     DJGPP specific changes.
        =======================

        The DJGPP port of Bison offers LFN and SFN support depending on which
        OS it is running. If LFN support is available or not is determinated at
        run time. If LFN support is available (DOS session under Win9X), the
        standard posix file name extensions will be used. These are: y.tab.c,
        y.tab.c++, y.tab.h, y.output, etc. If only SFN support is available
        (plain DOS), then the standard MSDOS short file names will be used.
        These are: y_tab.c, y_tab.h, y.out, etc.
        It should be noticed that this bison version needs the m4 program as
        back end to generate the parser file (y.tab.c etc.) from the skeleton
        files. This implies that m4 must always be installed to get bison
        working. m4 will use a couple of m4 scripts that will be installed in
        /dev/env/DJDIR/share/bison and shall not be removed.
        It should also be noticed that the skeleton files bison.simple and
        bison.hairy are no longer supported. This applies also to the environ-
        ment variables BISON_HAIRY and BISON_SIMPLE. Those variables are *no*
        longer honored at all.
        The kind of skeleton file bison.hairy is no longer supported at all.
        The skeleton file bison.simple is now called yacc.c and is an m4 script.
        The other two skeleton files supported by this bison version are glr.c
        and lalr1.cc. The first one is a generalized LR C parser based on
        Bison's LALR(1) tables and the second one is a experimental C++ parser
        class.
        As has been told before, bison uses m4 to generate the parser file.
        This is done by forking and using pipes for the IPC. MSDOS does not
        support this functionality so this has been reproduced in the usual
        way by redirecting stdin and stdout of bison and m4 to temporary files
        and processing these files in sequence. All the changes to the sources
        are documented in the djgpp/diffs file.

        Please **read** the docs.


2.:     Installing the binary package.
        ==============================

2.1.:   Copy the binary distribution into the top DJGPP installation directory,
        just unzip it preserving the directory structure running *ONE* of the
        following commands:
          unzip32 bsn1875b.zip      or
          djtarx bsn1875b.zip       or
          pkunzip -d bsn1875b.zip



3.:     Building the binaries from sources.
        ===================================

3.1.:   To build the binaries you will need the following binary packages:
          djdev203.zip (or a later but NOT a prior version)
          bsh204b.zip  (or a later but NOT a prior version)
          gcc342b.zip, bnu215b.zip, mak3791b.zip,
          fil40b.zip, shl20jb.zip, txt20b.zip,
          txi47b.zip, grep24b.zip, sed412b.zip,
          m4-14b.zip.

        If you want to run the check you will need also:
          dif281b.zip

        All this packages can be found in the v2gnu directory of any
        delorie.com mirror.
        You will need bsh203b.zip or later and *NOT* a prior version or the
        build will fail. The same applies to djdev203.zip. All the other
        packages are the ones I have used to build the binaries from this
        sources. Previuos versions of this packages may do the job as well but
        I have not tested this.

3.2.:   Create a temporary directory and copy the source package into the
        directory. If you download the source distribution from one of the
        DJGPP archives, just unzip it preserving the directory structure
        running *ONE* of the following commands:
          unzip32 bsn1875s.zip      or
          djtarx bsn1875s.zip       or
          pkunzip -d bsn1875s.zip

3.3.:   If for some reason you want to reconfigure the package cd into the top
        srcdir (bison-1.875) and run the following commands:
          del djgpp\config.cache
          make clean
          djgpp\config

        Please note that you *MUST* delete the config.cache file in the djgpp
        subdir or you will not really reconfigure the sources because the
        configuration informations will be read from the cache file instead
        of being newly computed.
        To build the programs in a directory other than where the sources are,
        you must add the parameter that specifies the source directory,
        e.g:
          x:\src\gnu\bison-1.875\djgpp\config x:/src/gnu/bison-1.875

        Lets assume you want to build the binaries in a directory placed on a
        different drive (z:\build in this case) from where the sources are,
        then you will run the following commands:
          z:
          md \build
          cd \build
          x:\src\gnu\bison-1.875\djgpp\config x:/src/gnu/bison-1.875

        The order of the options and the srcdir option does not matter. You
        *MUST* use forward slashes to specify the source directory.

        The batch file will set same environment variables, make MSDOS specific
        modifications to the Makefile.ins and supply all other needed options
        to the configure script.


3.4.:   To compile the package run from the top srcdir the command:
          make

3.5.:   Now you can run the tests if you like. From the top srcdir run the
        command:
          make check

        Non test should fail.
        Please note that the testsuite only works with LFN available. On plain
        DOS, most of the tests will fail due to invalid DOS names.

3.6.:   To install the binaries, header, library, catalogs, and info docs
        run the following command from the top srcdir:
          make install
        or
          make install prefix=z:/some/other/place

        This will install the products into your DJGPP installation tree given
        by the default prefix "/dev/env/DJDIR". If you prefer to install them
        into some other directory you will have to set prefix to the appropiate
        value.



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


Enjoy.

        Guerrero, Juan Manuel <st001906@hrz1.hrz.tu-darmstadt.de>
