build phobos as .so

[WalterBright]

Build phobos as .so as well as .a

[WalterBright]

Needs dlang/druntime#470

[WalterBright]

Remember to set export to something like this in order to use the shared library:

export LD_LIBRARY_PATH=/home/walter/cbx/mars/phobos/generated/linux/release/64:/home/walter/cbx/mars
/phobos/generated/linux/release/32

and build your app like this:

dmd foo -defaultlib=phobos2so

and it should link with the shared library. Linking with the static library is the default, and works as before.

[WalterBright]

This is currently only for linux.

[ghost]

Those instructions should be in the docs somewhere.

[WalterBright]

Of course. But I don't want to spend time writing it all up unless we are sure this is the way we're going. Remember, nobody liked my last scheme :-)

[MartinNowak]

Remember, nobody liked my last scheme :-)

Mine wasn't the right either.

dmd foo -defaultlib=phobos2so

Another way to do this is to install phobos2.so and phobos.a and use the following link flags

• to optionally link against a shared library
  -defaultlib= -debuglib= -L-lphobos2 -L-lcurl -L-ldl -L-lpthread -L-lm -L-lrt
• to mandatory link against a static library
  -defaultlib= -debuglib= -L-Bstatic -L-lphobos2 -L-Bdynamic -L-lcurl -L-ldl -L-lpthread -L-lm -L-lrt

BTW I hope we can get rid of the defaultlib and debuglib flags in the near future and handle this configuration issue with DFLAGS and dmd.conf.
This would also solve the link order bugs (Bugzilla 7044, Stackoverflow) we have with libcurl and which will happen again with libdl.

[MartinNowak]

I'm fine with this pull request, so please merge when the autotester goes green.

[andralex]

This is an unusual convention. How about just leaving it to the extension? LIBSO = $(ROOT)/libphobos2.so

[WalterBright]

I tried that, it doesn't work to have both libphobos2.a and libphobos2.so. There's no linker switch to force picking one or the other.

[jpf91]

There is: bracket the -lphobos part with -Bstatic and -Bdynamic (those are linker flags. If you pass them to gcc you have to prepend -Wl,)

Example:
gcc -Wl,-Bstatic -lphobos -Wl,-Bdynamic
(-Bdynamic is default)

[andralex]

Let's move forward with what we have in the interest of time. I'll pull.

[WalterBright]

My reading of -Bdynamic was it didn't have pervasive support.