meta-ros/recipes-ros/ros-canopen/socketcan-interface/0001-find-and-link-the-thread-library-properly.patch

From 16469e41f490c96d01dd8d894b784baf3d20f340 Mon Sep 17 00:00:00 2001
From: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Date: Tue, 16 Jan 2018 15:57:59 +0100
Subject: [PATCH] find and link the thread library properly

Compiling socketcan_dump in the socketcan_interface package fails in
the bitbake cross-compile tool chain with this linker problem:

```
| /[...]/libexec/arm-oe-linux-gnueabi/gcc/arm-oe-linux-gnueabi/7.2.0/ld: CMakeFiles/socketcan_dump.dir/src/candump.cpp.o: undefined reference to symbol 'pthread_getspecific@@GLIBC_2.4'
| /[...]/armv5e-oe-linux-gnueabi/socketcan-interface/0.6.8-r0/recipe-sysroot/lib/libpthread.so.0: error adding symbols: DSO missing from command line
| collect2: error: ld returned 1 exit status
| CMakeFiles/socketcan_dump.dir/build.make:115: recipe for target 'devel/lib/socketcan_interface/socketcan_dump' failed
| make[2]: *** [devel/lib/socketcan_interface/socketcan_dump] Error 1
| make[2]: Leaving directory '/[...]/armv5e-oe-linux-gnueabi/socketcan-interface/0.6.8-r0/build'
| CMakeFiles/Makefile2:171: recipe for target 'CMakeFiles/socketcan_dump.dir/all' failed
| make[1]: *** [CMakeFiles/socketcan_dump.dir/all] Error 2
| make[1]: Leaving directory '/[...]/armv5e-oe-linux-gnueabi/socketcan-interface/0.6.8-r0/build'
| Makefile:132: recipe for target 'all' failed
| make: *** [all] Error 2
| WARNING: exit code 2 from a shell command.
| ERROR: Function failed: do_compile (log file is located at /[...]/armv5e-oe-linux-gnueabi/socketcan-interface/0.6.8-r0/temp/log.do_compile.20764)
```

This error above was identified in meta-ros, the OpenEmbedded layer
for ROS packages [1, 2].

The cmake script does not ensure that the thread library is linked;
hence, it does not work on builds for some architectures. The commit
provides in the CMake build script a standard way to find the Thread
library and link it.

[1] https://github.com/bmwcarit/meta-ros
[2] https://github.com/bmwcarit/meta-ros/issues/574

Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>

Upstream-Status: Submitted [https://github.com/ros-industrial/ros_canopen/pull/263]

Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>

---
 socketcan_interface/CMakeLists.txt | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/socketcan_interface/CMakeLists.txt b/socketcan_interface/CMakeLists.txt
index 934451d..340872f 100644
--- a/socketcan_interface/CMakeLists.txt
+++ b/socketcan_interface/CMakeLists.txt
@@ -13,6 +13,8 @@ find_package(Boost REQUIRED
     thread
 )
 
+find_package(Threads REQUIRED)
+
 catkin_package(
   INCLUDE_DIRS
     include
@@ -43,6 +45,7 @@ target_link_libraries(socketcan_dump
    socketcan_interface_string
    ${catkin_LIBRARIES}
    ${Boost_LIBRARIES}
+   ${CMAKE_THREAD_LIBS_INIT}
 )
 
 # socketcan_bcm