Update documentation for cross compilation
Closed this issue · 7 comments
The cross compilation fails for internal dependencies of FAST-RTPS if the toolchain requires a sysroot to work, and if that sysroot is specified using CMAKE_TOOLCHAIN_FILE. See PR #216 for details. While this change gets merged upstream, I propose to update the documentation so that the corresponding fix can be applied manually (if needed).
Here's the link to the proposed documentation change:
dgoel/ros2_arm_wiki@2eb8864
Thanks!
Hello,
I have no error when cross-compiling fastrtps in ament. Even though I use/set CMAKE_TOOLCHAIN_FILE. I get the package compiled and the binaries are for the correct architecture. So the toolchain file seems to be taken into account. Even if your patch in FastRTPS seems legitimate, I am not sure to understand why this is working on my side (I am not using a sysroot so I guess all the necessary libraries are available in my toolchain..)
The bug happens if the toolchain requires a sysroot to work. If that case, the compiler detection fails as cmake tries to compile a dummy program without adding sysroot to the compile command.
Hi @dgoel ,
I also have no error when I'm cross-compiling with a sysroot (I use it to enable python). Can you give us more info to understand/reproduce your issue ? (toolchain, ament build cmd, toolchainfile, ...)
I am using a custom toolchain and sysroot using open-embedded.
The ament command is exactly the same as mentioned in your wiki except that my toolchain file is different. Here it is anyway:
export CROSS_COMPILE=arm-oe-linux-gnueabi-
src/ament/ament_tools/scripts/ament.py \
build \
--force-cmake-configure \
--cmake-args -DCMAKE_BUILD_TYPE=Release -DCMAKE_TOOLCHAIN_FILE=`pwd`/arm_toolchainfile.cmake -DCMAKE_VERBOSE_MAKEFILE:BOOL=ON \
-DTHIRDPARTY=ON --
Here's my toolchain file:
set(CMAKE_SYSTEM_NAME Linux)
set(CMAKE_SYSTEM_VERSION 1)
set(CMAKE_SYSTEM_PROCESSOR arm)
set(CMAKE_C_COMPILER $ENV{CROSS_COMPILE}gcc)
set(CMAKE_CXX_COMPILER $ENV{CROSS_COMPILE}g++)
set(CMAKE_SYSROOT /path/to/sysroot)
set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -O2" CACHE STRING "" FORCE)
set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -O2" CACHE STRING "" FORCE)
# where is the target environment
set(CMAKE_FIND_ROOT_PATH ${CMAKE_CURRENT_LIST_DIR}/install)
set(CMAKE_FIND_ROOT_PATH_MODE_PROGRAM NEVER)
set(CMAKE_FIND_ROOT_PATH_MODE_PACKAGE ONLY)
set(CMAKE_FIND_ROOT_PATH_MODE_LIBRARY ONLY)
set(CMAKE_FIND_ROOT_PATH_MODE_INCLUDE ONLY)
# This assumes that pthread will be available on the target system
# (this emulates that the return of the TRY_RUN is a return code "0"
set(THREADS_PTHREAD_ARG "0"
CACHE STRING "Result from TRY_RUN" FORCE)
And here's the error that I get without my proposed patch:
....
-- Check for working C compiler: /usr/bin/arm-oe-linux-gnueabi/arm-oe-linux-gnueabi-gcc
-- Check for working C compiler: /usr/bin/arm-oe-linux-gnueabi/arm-oe-linux-gnueabi-gcc -- broken
-- Configuring incomplete, errors occurred!
See also "/mnt/store/ros2/arm_ws/build/fastrtps/external/fastcdr/CMakeFiles/CMakeOutput.log".
See also "/mnt/store/ros2/arm_ws/build/fastrtps/external/fastcdr/CMakeFiles/CMakeError.log".
CMake Error at /usr/share/cmake-3.5/Modules/CMakeTestCCompiler.cmake:61 (message):
The C compiler
"/usr/bin/arm-oe-linux-gnueabi/arm-oe-linux-gnueabi-gcc"
is not able to compile a simple test program.
It fails with the following output:
Change Dir: /mnt/store/ros2/arm_ws/build/fastrtps/external/fastcdr/CMakeFiles/CMakeTmp
Run Build Command:"/usr/bin/make" "cmTC_d3157/fast"
/usr/bin/make -f CMakeFiles/cmTC_d3157.dir/build.make
CMakeFiles/cmTC_d3157.dir/build
make[1]: Entering directory
'/mnt/store/ros2/arm_ws/build/fastrtps/external/fastcdr/CMakeFiles/CMakeTmp'
Building C object CMakeFiles/cmTC_d3157.dir/testCCompiler.c.o
/usr/bin/arm-oe-linux-gnueabi/arm-oe-linux-gnueabi-gcc
-o CMakeFiles/cmTC_d3157.dir/testCCompiler.c.o -c
/mnt/store/ros2/arm_ws/build/fastrtps/external/fastcdr/CMakeFiles/CMakeTmp/testCCompiler.c
Linking C executable cmTC_d3157
/usr/bin/cmake -E cmake_link_script CMakeFiles/cmTC_d3157.dir/link.txt
--verbose=1
/usr/bin/arm-oe-linux-gnueabi/arm-oe-linux-gnueabi-gcc
CMakeFiles/cmTC_d3157.dir/testCCompiler.c.o -o cmTC_d3157 -rdynamic
/usr/libexec/arm-oe-linux-gnueabi/gcc/arm-oe-linux-gnueabi/5.2.0/real-ld:
error: cannot open crt1.o: No such file or directory
/usr/libexec/arm-oe-linux-gnueabi/gcc/arm-oe-linux-gnueabi/5.2.0/real-ld:
error: cannot open crti.o: No such file or directory
/usr/libexec/arm-oe-linux-gnueabi/gcc/arm-oe-linux-gnueabi/5.2.0/real-ld:
error: cannot open crtbegin.o: No such file or directory
/usr/libexec/arm-oe-linux-gnueabi/gcc/arm-oe-linux-gnueabi/5.2.0/real-ld:
error: cannot open crtend.o: No such file or directory
/usr/libexec/arm-oe-linux-gnueabi/gcc/arm-oe-linux-gnueabi/5.2.0/real-ld:
error: cannot open crtn.o: No such file or directory
/usr/libexec/arm-oe-linux-gnueabi/gcc/arm-oe-linux-gnueabi/5.2.0/real-ld:
error: cannot find -lgcc
/usr/libexec/arm-oe-linux-gnueabi/gcc/arm-oe-linux-gnueabi/5.2.0/real-ld:
error: cannot find -lgcc_s
/usr/libexec/arm-oe-linux-gnueabi/gcc/arm-oe-linux-gnueabi/5.2.0/real-ld:
error: cannot find -lc
/usr/libexec/arm-oe-linux-gnueabi/gcc/arm-oe-linux-gnueabi/5.2.0/real-ld:
error: cannot find -lgcc
/usr/libexec/arm-oe-linux-gnueabi/gcc/arm-oe-linux-gnueabi/5.2.0/real-ld:
error: cannot find -lgcc_s
collect2: error: ld returned 1 exit status
CMakeFiles/cmTC_d3157.dir/build.make:97: recipe for target 'cmTC_d3157'
failed
make[1]: *** [cmTC_d3157] Error 1
make[1]: Leaving directory
'/mnt/store/ros2/arm_ws/build/fastrtps/external/fastcdr/CMakeFiles/CMakeTmp'
Makefile:126: recipe for target 'cmTC_d3157/fast' failed
make: *** [cmTC_d3157/fast] Error 2
CMake will not be able to correctly generate this project.
Call Stack (most recent call first):
CMakeLists.txt
CMake Error at cmake/dev/eprosima_libraries.cmake:120 (message):
Cannot configure Git submodule fastcdr
Call Stack (most recent call first):
CMakeLists.txt:197 (find_eprosima_package)
-- Configuring incomplete, errors occurred!
See also "/mnt/store/ros2/arm_ws/build/fastrtps/CMakeFiles/CMakeOutput.log".
See also "/mnt/store/ros2/arm_ws/build/fastrtps/CMakeFiles/CMakeError.log".
<== Command '. /mnt/store/ros2/arm_ws/build/fastrtps/cmake__build.sh && /usr/bin/cmake /mnt/store/ros2/arm_ws/src/eProsima/Fast-RTPS -DCMAKE_BUILD_TYPE=Release -DCMAKE_TOOLCHAIN_FILE=/mnt/store/ros2/arm_ws/arm_toolchainfile.cmake -DCMAKE_VERBOSE_MAKEFILE:BOOL=ON -DTHIRDPARTY=ON -DCMAKE_INSTALL_PREFIX=/mnt/store/ros2/arm_ws/install' failed in '/mnt/store/ros2/arm_ws/build/fastrtps' with exit code '1'
<== Command '. /mnt/store/ros2/arm_ws/build/fastrtps/cmake__build.sh && /usr/bin/cmake /mnt/store/ros2/arm_ws/src/eProsima/Fast-RTPS -DCMAKE_BUILD_TYPE=Release -DCMAKE_TOOLCHAIN_FILE=/mnt/store/ros2/arm_ws/arm_toolchainfile.cmake -DCMAKE_VERBOSE_MAKEFILE:BOOL=ON -DTHIRDPARTY=ON -DCMAKE_INSTALL_PREFIX=/mnt/store/ros2/arm_ws/install' failed in '/mnt/store/ros2/arm_ws/build/fastrtps' with exit code '1'
As you can see, the compiler check fails because sysroot is not passed through when cmake tries to compile a simple, test program.
Let me know if you need any other information.
Thanks!
Thanks for the details, last time I got this issue of compiler check fail was went I tried to compile a library for Nuttx. So I used
set(CMAKE_FORCE_C_COMPILER $ENV{CROSS_COMPILE}gcc cortex_m_compiler)
set(CMAKE_FORCE_CXX_COMPILER $ENV{CROSS_COMPILE}g++ cortex_m_compiler)
to avoid the compiler check as the test program was using undefined function/compiler parameters.
I did try forcing the compiler but that didn't work either, and I got the same error as above. Further, cmake discourages the use of this feature:
https://cmake.org/cmake/help/v3.5/module/CMakeForceCompiler.html
Discouraged. Avoid using this module if possible. It will be deprecated by a future version of CMake once alternatives have been provided for all toolchain file use cases.
Cmake 3.6 introduced a new feature (CMAKE_TRY_COMPILE_TARGET_TYPE ) to skip such checks but I am using cmake 3.5.1 (default on ubuntu 16.04).
This has been fixed in eProsima (see the above referenced issue)