http://bugs.orocos.org/show_bug.cgi?id=994

Summary: Forward pkgconfig compiler and linker flags to Orocos
macros when using orocos_use_package()
Product: Toolchain
Version: master
Platform: All
OS/Version: All
Status: NEW
Severity: enhancement
Priority: P3
Component: RTT
AssignedTo: orocos-dev [..] ...
ReportedBy: meyer [..] ...
CC: orocos-dev [..] ...
Estimated Hours: 0.0

In the current master branch orocos_use_package() is implemented as cmake
function. When OROCOS_NO_AUTO_LINKING is set, there is no way to access the
${PACKAGE}_LIBRARIES variable from the outside to do the linking manually.

Beside of that, some packages need to export compiler (and/or linker) flags,
that have to be applied by all users of the package. A typical example is the
OROCOS_TARGET variable or other definitions, that could be contained in the pc
file. With this patch, the orocos_add_xxx macros will use compiler and linker
flags exported by other packages. This is motivated by the way rosbuild works
for ROS packages. To make this work, orocos_use_package has been converted to a
macro.

A minor issue with this patch applied is that the -DOROCOS_TARGET=...
definition will be added twice, because it is listed in rtt's pc file and
additionally set when including UseOrocos-RTT.cmake.