Add PC files for library

[taozuhong]

No description provided.

[freddy77]

I would put these files in CMakeLists.txt within a if(WIN32)...endif(WIN32) condition, they are only useful and working for Windows.

[taozuhong]

the pkg-config file works for Linux/macOS/MINGW(Windows), not windows only.

[taozuhong]

the Libs.private should update with the build tool, because it will change with the operating system.

[freddy77]

Looking at initial issue and https://github.com/msys2/MINGW-packages/blob/master/mingw-w64-freetds/PKGBUILD I suppose we should first address Autoconf instead of CMake (not saying CMake should not be supported!).

[freddy77]

@taozuhong how is the state of this PR?

[taozuhong]

For CMake, it's OK to be merged. autotool not yet.

[freddy77]

I tried to test it but it does not work. I compiled installed and tested, something like

# cleanup
$ rm -rf cmake
$ rm -rf "$HOME/ftds_install"

# build and install cmake
$ mkdir cmake
$ cd cmake
$ cmake "-DCMAKE_INSTALL_PREFIX:PATH=$HOME/ftds_install" ..
$ make install

# prepare test program
$ cat <<EOF > test.c
#include <stdio.h>
#include <sqldb.h>

int main(void)
{
   printf("login is %p\n", dblogin());
}
EOF

$ export PKG_CONFIG_PATH=$HOME/ftds_install/lib64/pkgconfig

$ gcc -O2 -Wall $(pkg-config --cflags --libs dblib)

compilation fails with

Package iconv was not found in the pkg-config search path.
Perhaps you should add the directory containing `iconv.pc'
to the PKG_CONFIG_PATH environment variable
Package 'iconv', required by 'dblib', not found
test.c:2:10: fatal error: sqldb.h: No such file or directory
    2 | #include <sqldb.h>
      |          ^~~~~~~~~
compilation terminated.

after removing iconv from dependency (only for Windows)

test.c:2:10: fatal error: sqldb.h: No such file or directory
    2 | #include <sqldb.h>
      |          ^~~~~~~~~
compilation terminated.

checking what pkg-config thinks

$ pkg-config --cflags --libs dblib
-I/home/fziglio/ftds_install/include/freetds -L/home/fziglio/ftds_install/lib/ -lsybdb 

however includes are not there

$ find /home/fziglio/ftds_install/include/freetds
/home/fziglio/ftds_install/include/freetds
/home/fziglio/ftds_install/include/freetds/version.h

If I pass a specific directory to cmake is even worse, for instance

cmake -DCMAKE_INSTALL_INCLUDEDIR=inc/ftds "-DCMAKE_INSTALL_PREFIX:PATH=$HOME/ftds_install" ..

Trying to understand how to better produce PC files with CMake, it's not that easy. Maybe better to start with Autoconf?

[taozuhong]

CMake to generate pc file works with MSYS2 environment, I have tested it.

# build freetds
mkdir build
cd build
cmake -DCMAKE_INSTALL_PREFIX=/ucrt64 ..
ninja install

# build example app
..........

[freddy77]

I managed to reproduce your settings. Yes, it works, but because you installed on default directory so you don't need -I setting, not because the -I directory you specify is correct. Try to pass -DCMAKE_INSTALL_PREFIX=/ucrt64addon, adjust PKG_CONFIG_PATH and it won't compile. I'll try to find some better solution this evening.

[taozuhong]

U r right, it's not the final solution, it need be update with new plan(ctlib/dblib/etc).

BTW, could export libtds library directly(libtds.pc)?

[freddy77]

This commit improves a bit, at least if you set different defaults freddy77@2fe6778.