= Building individual libraries with cmake =

== help ==

In a configured cmake workspace, `make help` will display a list of available targets.  Example:
{{{
% make help 
The following are some of the valid targets for this Makefile:
... all (the default if no target is provided)
... clean
... depend
... edit_cache
... install
... install/local
... install/strip
... list_install_components
... package
... package_source
... rebuild_cache
... boost_date_time
... boost_date_time-mt-shared
... boost_date_time-mt-shared-debug
... boost_date_time-mt-static
... boost_date_time-mt-static-debug
... boost_date_time-shared
... boost_date_time-shared-debug
... boost_date_time-static
... boost_date_time-static-debug
... boost_filesystem
... boost_filesystem-mt-shared
... boost_filesystem-mt-shared-debug
... boost_filesystem-mt-static
... boost_filesystem-mt-static-debug
... boost_filesystem-shared
... boost_filesystem-shared-debug
... boost_filesystem-static
... boost_filesystem-static-debug
[etc]
}}}

You can build any target by passing it as an argument:

{{{
% make boost_signals-static
[  0%] Building CXX object libs/signals/src/CMakeFiles/boost_signals-static.dir/trackable.cpp.o
[  0%] Building CXX object libs/signals/src/CMakeFiles/boost_signals-static.dir/connection.cpp.o
[100%] Building CXX object libs/signals/src/CMakeFiles/boost_signals-static.dir/named_slot_map.cpp.o
[100%] Building CXX object libs/signals/src/CMakeFiles/boost_signals-static.dir/signal_base.cpp.o
[100%] Building CXX object libs/signals/src/CMakeFiles/boost_signals-static.dir/slot.cpp.o
Linking CXX static library ../../../lib/libboost_signals-gcc41-1_35.a
[100%] Built target boost_signals-static
}}}

== Preprocessing ==

In build directories corresponding to a source library containing a `CMakeLists.txt` containing a 
`boost_add_library` invocation (e.g. build/libs/signals/src, build/libs/filesystem/src), 
more detailed targets are available:
{{{
% cd libs/signals/src
% make help
The following are some of the valid targets for this Makefile:
  [many omitted]
... signal_base.o
... signal_base.i
... signal_base.s
... slot.o
... slot.i
... slot.s
}}}

making `slot.i` will run `slot.cpp` through the preprocessor:
{{{
% make slot.i
Preprocessing CXX source to CMakeFiles/boost_signals-mt-shared.dir/slot.cpp.i
}}}
If you are always interested in seeing the compiler flags you can enable `CMAKE_VERBOSE_MAKEFILES` via `ccmake`
, or for a one-off just pass `VERBOSE=1` on the command line:
{{{
% make VERBOSE=1 slot.i
make[1]: Entering directory `/home/troy/Projects/boost/branches/CMake/Boost_1_35_0-build'
Preprocessing CXX source to CMakeFiles/boost_signals-mt-shared.dir/slot.cpp.i
cd /home/troy/Projects/boost/branches/CMake/Boost_1_35_0-build/libs/signals/src && /usr/bin/gcc-4.1  
-DBOOST_ALL_NO_LIB=1 -DBOOST_SIGNALS_NO_LIB=1 -Dboost_signals_mt_shared_EXPORTS -fPIC 
-I/home/troy/Projects/boost/branches/CMake/Boost_1_35_0     -O3 -DNDEBUG -DBOOST_SIGNALS_DYN_LINK=1   
-pthread -D_REENTRANT -E /home/troy/Projects/boost/branches/CMake/Boost_1_35_0/libs/signals/src/slot.cpp > CMakeFiles/boost_signals-mt-shared.dir/slot.cpp.i
}}}