== How to build expat with cmake (experimental) ==

The cmake based buildsystem for expat works on Windows (cygwin, mingw, Visual
Studio) and should work on all other platform cmake supports.

Assuming ~/expat-2.4.6 is the source directory of expat, add a subdirectory
build and change into that directory:
~/expat-2.4.6$ mkdir build && cd build
~/expat-2.4.6/build$

From that directory, call cmake first, then call make, make test and
make install in the usual way:
~/expat-2.4.6/build$ cmake ..
-- The C compiler identification is GNU
-- The CXX compiler identification is GNU
....
-- Configuring done
-- Generating done
-- Build files have been written to: /home/patrick/expat-2.4.6/build

If you want to specify the install location for your files, append
-DCMAKE_INSTALL_PREFIX=/your/install/path to the cmake call.

~/expat-2.4.6/build$ make && make test && make install
Scanning dependencies of target expat
[  5%] Building C object CMakeFiles/expat.dir/lib/xmlparse.c.o
[ 11%] Building C object CMakeFiles/expat.dir/lib/xmlrole.c.o
....
-- Installing: /usr/local/lib/pkgconfig/expat.pc
-- Installing: /usr/local/bin/xmlwf
-- Installing: /usr/local/share/man/man1/xmlwf.1

For Windows builds, you must make sure to call cmake from an environment where
your compiler is reachable, that means either you call it from the
Visual Studio Command Prompt or when using mingw, you must open a cmd.exe and
make sure that gcc can be called. On Windows, you also might want to specify a
special Generator for CMake:
for Visual Studio builds do:
cmake .. -G "Visual Studio 15 2017" && msbuild /m expat.sln
for mingw builds do:
cmake .. -G "MinGW Makefiles" -DCMAKE_INSTALL_PREFIX=D:\expat-install
    && gmake && gmake install