search

ros / meta-ros

OpenEmbedded Layers for ROS 1 and ROS 2
MIT License
376 stars 250 forks source link

INTERFACE_LINK_LIBRARIES in SDK does include yocto build path #793

Open lorenzo-gi opened 3 years ago

lorenzo-gi commented 3 years ago

Hello, I am using the Zeus branch that i understand is no more supported. I have generated an SDK for my image. I then tried to compile a "hello world" for fastRTPS and got errors because it was not finding tinyxml2 in a certain path. The strange thing was that it was pointing to the build folder of fastrtps inside yocto and not to the SDK folder. Looking into <sdk-folder>/sysroots/aarch64-poky-linux/usr/share/fastrtps/cmake/fastrtps-targets.cmake I saw this:

set_target_properties(fastrtps PROPERTIES
   INTERFACE_INCLUDE_DIRECTORIES "${_IMPORT_PREFIX}/include"
   INTERFACE_LINK_LIBRARIES "fastcdr;-lpthread;dl;/home/yocto/imx-yocto-L5.4.24_2.1.0/build-inm034r10/tmp/work/aarch64-poky-linux/fastrtps/1.8.2-1-r0/recipe-sysroot/usr/lib/libtinyxml2.so;\$<\$<BOOL:1>:   OpenSSL::SSL\$<SEMICOLON>OpenSSL::Crypto>;\$<\$<BOOL:>:iphlpapi\$<SEMICOLON>Shlwapi>"
 )

and it is pointing to my build directory. I fixed by writing this and pointing to the SDK:

set_target_properties(fastrtps PROPERTIES
   INTERFACE_INCLUDE_DIRECTORIES "${_IMPORT_PREFIX}/include"
   INTERFACE_LINK_LIBRARIES "fastcdr;-lpthread;dl;/home/yocto/sdk/fsl-imx-xwayland/sysroots/aarch64-poky-linux/usr/lib/libtinyxml2.so;\$<\$<BOOL:1>:OpenSSL::SSL\$<SEMICOLON>OpenSSL::Crypto>;\$<\$<BOOL:>:  iphlpapi\$<SEMICOLON>Shlwapi>"
 )

Sorry if it was not very clear but I do not totally understand Cmake.

hannes09 commented 3 years ago

I have found a similar problem like this also with rcl-yaml-param-parser, in an sdk build librcl->librcl_yaml_param_parserhas a hardcoded wrong path in rcl_yaml_param_parser/cmake/rcl_yaml_param_parserExport.cmake .

I have found a workaround by removing libyaml from DEPENDS of rcl-yaml-param-parser.

Maybe https://github.com/ros2/rcl/issues/638 is relayted to this problem?

beralt commented 2 years ago

Having absolute paths in certain packages is something I'm running in to as well. I'm trying to build an SDK. After a number of changes, which I'm planning to offer as a PR, I can build an SDK that is capable of building ROS2 components. But these absolute paths still pop up and CMake correctly warns about them.

Most of the ROS2 packages have been fixed but some external dependencies still result in absolute paths. These include libyaml in rcl-yaml-param-parser. The fixes for these is to make yaml a CMake target using add_library for example.

For an OpenEmbedded build an absolute path in the CMake Config exports should never be allowed, the sysroot for the package is temporary and thus the path does not make any sense. I have modified the ament-cmake-target-dependencies to emit a warning when it is about to use an absolute path.

Any ideas about this? I'm not sure why upstream ament-cmake is using absolute paths. Any ROS2 package that has external dependencies and does not generate a CMake target for it is affected by this.