Installation on Microsoft Windows:

There are three ways to create binaries of this package for Microsoft Windows:
1) Native binaries, built using the mingw tool chain.
2) Native binaries, built using the MS Visual C/C++ tool chain.
3) Binaries for the Cygwin environment.

===============================================================================
1) Native binaries, built using the mingw tool chain.

   I recommend to use the Cygwin environment as the development environment (*)
   and mingw only as the target (runtime, deployment) environment.
   For this, you need to install
     * Cygwin (from https://cygwin.com/),
     * some packages available from the Cygwin package installer:
         make
     * the mingw cross-compilation tools and runtime package, available from
       the Cygwin package installer (setup-x86_64.exe):
       - for creating 32-bit binaries: packages
           mingw64-i686-gcc-core,
           mingw64-i686-headers,
           mingw64-i686-runtime
       - for creating 64-bit binaries: packages
           mingw64-x86_64-gcc-core,
           mingw64-x86_64-headers,
           mingw64-x86_64-runtime

   Building 32-bit binaries for mingw is achieved through the following
   preparation, configure, and build commands:

      PATH=/usr/local/mingw32/bin:$PATH
      export PATH
      ./configure --host=i686-w64-mingw32 --prefix=/usr/local/mingw32 \
            CC=i686-w64-mingw32-gcc \
            CPPFLAGS="-I/usr/local/mingw32/include -Wall" \
            LDFLAGS="-L/usr/local/mingw32/lib"
      make
      make check

   Building 64-bit binaries for mingw is achieved through the following
   preparation, configure, and build commands:

      PATH=/usr/local/mingw64/bin:$PATH
      export PATH
      ./configure --host=x86_64-w64-mingw32 --prefix=/usr/local/mingw64 \
            CC=x86_64-w64-mingw32-gcc \
            CPPFLAGS="-I/usr/local/mingw64/include -Wall" \
            LDFLAGS="-L/usr/local/mingw64/lib"
      make
      make check

   Installation:

      make install

   (*) Note: The MSYS2 environment as a development environment is *not*
       supported.  This environment contains an ignoble and ignominious hack:
       In a program invocation, the program *by default* receives different
       arguments than the ones that the caller has passed.  See
       <https://www.msys2.org/wiki/Porting/#filesystem-namespaces>.
       All program invocations in this environment are therefore unreliable.

===============================================================================
2) Native binaries, built using the MS Visual C/C++ tool chain.

   Note that binaries created with MSVC have a distribution constraint: They
   depend on a closed-source library ('msvcr90.dll' for MSVC 9.0,
   'vcruntime140.dll' for MSVC 14.0, and so on) which is not normally part of
   a Windows installation.
   You cannot distribute 'vcruntime*.dll' with the binaries - this would be a
   violation of the GPL and of the Microsoft EULA.
   You can distribute the binaries without including 'vcruntime*.dll'. Users
   who don't have this library on their system will require to pull some files
   (api-ms-win*.dll) through the Windows Update mechanism, see
   https://support.microsoft.com/en-us/kb/2999226 .

   This recipe requires MS Visual C/C++ 9.0 or newer.
   You don't need the Visual Studio IDE, just the C/C++ tool chain.
   As of 2016, you can install the MS Visual C/C++ 14.0 tool chain from
   http://landinghub.visualstudio.com/visual-cpp-build-tools (it's the file
   visualcppbuildtools_full.exe).

   This recipe requires also a Cygwin environment (with 'bash', the common POSIX
   commands, and 'make') as a build environment. Building with 'nmake' is not
   supported.
   For this, you need to install
     * Cygwin (from https://cygwin.com/),
     * some packages available from the Cygwin package installer:
         make

   You also need the scripts 'ar-lib' and 'compile' from
     https://git.savannah.gnu.org/gitweb/?p=automake.git;a=blob_plain;f=lib/ar-lib;hb=HEAD
     https://git.savannah.gnu.org/gitweb/?p=automake.git;a=blob_plain;f=lib/compile;hb=HEAD
   respectively.
   They may also be included in this package, in directory 'build-aux/'.
   Save them; the instructions below assume that you stored them in $HOME/msvc/.
   Make them executable:
      chmod a+x ar-lib compile

   Start a bash (from Cygwin).

   Make sure that the MSVC tools ("cl" etc.) are found in PATH and the
   environment variables INCLUDE and LIB are set appropriately.
   In a typical MSVC 9.0 installation, it can be achieved by running
     C:\Program Files\Microsoft Visual Studio 9.0\Common7\Tools\vsvars32.bat
   In a typical MSVC 14.0 installation on Windows 10, it can be achieved
   - for creating 32-bit binaries: through the following bash commands:

      # Set environment variables for using MSVC 14,
      # for creating native 32-bit Windows executables.

      # Windows C library headers and libraries.
      WindowsCrtIncludeDir='C:\Program Files (x86)\Windows Kits\10\Include\10.0.10240.0\ucrt'
      WindowsCrtLibDir='C:\Program Files (x86)\Windows Kits\10\Lib\10.0.10240.0\ucrt\'
      INCLUDE="${WindowsCrtIncludeDir};$INCLUDE"
      LIB="${WindowsCrtLibDir}x86;$LIB"

      # Windows API headers and libraries.
      WindowsSdkIncludeDir='C:\Program Files (x86)\Windows Kits\8.1\Include\'
      WindowsSdkLibDir='C:\Program Files (x86)\Windows Kits\8.1\Lib\winv6.3\um\'
      INCLUDE="${WindowsSdkIncludeDir}um;${WindowsSdkIncludeDir}shared;$INCLUDE"
      LIB="${WindowsSdkLibDir}x86;$LIB"

      # Visual C++ tools, headers and libraries.
      VSINSTALLDIR='C:\Program Files (x86)\Microsoft Visual Studio 14.0'
      VCINSTALLDIR="${VSINSTALLDIR}"'\VC'
      PATH=`cygpath -u "${VCINSTALLDIR}"`/bin:"$PATH"
      INCLUDE="${VCINSTALLDIR}"'\include;'"${INCLUDE}"
      LIB="${VCINSTALLDIR}"'\lib;'"${LIB}"

      export INCLUDE LIB

   - for creating 64-bit binaries: through the following bash commands:

     # Set environment variables for using MSVC 14,
     # for creating native 64-bit Windows executables.

     # Windows C library headers and libraries.
     WindowsCrtIncludeDir='C:\Program Files (x86)\Windows Kits\10\Include\10.0.10240.0\ucrt'
     WindowsCrtLibDir='C:\Program Files (x86)\Windows Kits\10\Lib\10.0.10240.0\ucrt\'
     INCLUDE="${WindowsCrtIncludeDir};$INCLUDE"
     LIB="${WindowsCrtLibDir}x64;$LIB"

     # Windows API headers and libraries.
     WindowsSdkIncludeDir='C:\Program Files (x86)\Windows Kits\8.1\Include\'
     WindowsSdkLibDir='C:\Program Files (x86)\Windows Kits\8.1\Lib\winv6.3\um\'
     INCLUDE="${WindowsSdkIncludeDir}um;${WindowsSdkIncludeDir}shared;$INCLUDE"
     LIB="${WindowsSdkLibDir}x64;$LIB"

     # Visual C++ tools, headers and libraries.
     VSINSTALLDIR='C:\Program Files (x86)\Microsoft Visual Studio 14.0'
     VCINSTALLDIR="${VSINSTALLDIR}"'\VC'
     PATH=`cygpath -u "${VCINSTALLDIR}"`/bin/amd64:"$PATH"
     INCLUDE="${VCINSTALLDIR}"'\include;'"${INCLUDE}"
     LIB="${VCINSTALLDIR}"'\lib\amd64;'"${LIB}"

     export INCLUDE LIB

   Building 32-bit binaries with MSVC is achieved through the following
   preparation, configure, and build commands:

      PATH=/usr/local/msvc32/bin:$PATH
      export PATH

      win32_target=_WIN32_WINNT_WINXP   # for MSVC 9.0
      win32_target=_WIN32_WINNT_VISTA   # possibly for MSVC >= 10.0
      win32_target=_WIN32_WINNT_WIN7    # possibly for MSVC >= 10.0
      win32_target=_WIN32_WINNT_WIN8    # possibly for MSVC >= 10.0

      ./configure --host=i686-w64-mingw32 --prefix=/usr/local/msvc32 \
            CC="$HOME/msvc/compile cl -nologo" \
            CFLAGS="-MD" \
            CXX="$HOME/msvc/compile cl -nologo" \
            CXXFLAGS="-MD" \
            CPPFLAGS="-D_WIN32_WINNT=$win32_target -I/usr/local/msvc32/include" \
            LDFLAGS="-L/usr/local/msvc32/lib" \
            LD="link" \
            NM="dumpbin -symbols" \
            STRIP=":" \
            AR="$HOME/msvc/ar-lib lib" \
            RANLIB=":"
      make
      make check

   Building 64-bit binaries with MSVC is achieved through the following
   preparation, configure, and build commands:

      PATH=/usr/local/msvc64/bin:$PATH
      export PATH

      win32_target=_WIN32_WINNT_WINXP   # for MSVC 9.0
      win32_target=_WIN32_WINNT_VISTA   # possibly for MSVC >= 10.0
      win32_target=_WIN32_WINNT_WIN7    # possibly for MSVC >= 10.0
      win32_target=_WIN32_WINNT_WIN8    # possibly for MSVC >= 10.0

      ./configure --host=x86_64-w64-mingw32 --prefix=/usr/local/msvc64 \
            CC="$HOME/msvc/compile cl -nologo" \
            CFLAGS="-MD" \
            CXX="$HOME/msvc/compile cl -nologo" \
            CXXFLAGS="-MD" \
            CPPFLAGS="-D_WIN32_WINNT=$win32_target -I/usr/local/msvc64/include" \
            LDFLAGS="-L/usr/local/msvc64/lib" \
            LD="link" \
            NM="dumpbin -symbols" \
            STRIP=":" \
            AR="$HOME/msvc/ar-lib lib" \
            RANLIB=":"
      make
      make check

   Installation:

      make install

===============================================================================
3) Binaries for the Cygwin environment.

   The generic instructions in the INSTALL file apply. But here are more
   specific ones.

   You need to install
     * Cygwin (from https://cygwin.com/),
     * some packages available from the Cygwin package installer:
         make
     * the Cygwin [cross-]compilation tools package, available from
       the Cygwin package installer (setup-x86_64.exe):
       - for creating 32-bit binaries: packages
           cygwin32-gcc-core,
           cygwin32
       - for creating 64-bit binaries: packages
           gcc-core

   Building 32-bit binaries for Cygwin must be done in a directory *outside*
   the Cygwin /home and /usr hierarchies. It is achieved through the following
   preparation, configure, and build commands:

      PATH=/usr/local/cygwin32/bin:/usr/i686-pc-cygwin/sys-root/usr/bin:$PATH
      export PATH
      ./configure --host=i686-pc-cygwin --prefix=/usr/local/cygwin32 \
            CC=i686-pc-cygwin-gcc \
            CPPFLAGS="-I/usr/local/cygwin32/include -Wall" \
            LDFLAGS="-L/usr/local/cygwin32/lib"
      make
      make check

   Building 64-bit binaries for Cygwin is achieved through the following
   preparation, configure, and build commands:

      PATH=/usr/local/cygwin64/bin:$PATH
      export PATH
      ./configure --host=x86_64-pc-cygwin --prefix=/usr/local/cygwin64 \
            CC=x86_64-pc-cygwin-gcc \
            CPPFLAGS="-I/usr/local/cygwin64/include -Wall" \
            LDFLAGS="-L/usr/local/cygwin64/lib"
      make
      make check

   Installation:

      make install

===============================================================================
Dependencies:

This package depends on GNU libiconv. (See the file DEPENDENCIES.) Before
building this package, you need to build GNU libiconv, in the same development
environment, with the same configure options, and install it ("make install").
===============================================================================