From 4c6eace6f756d15ae9639a503c9245d1e7fb12a9 Mon Sep 17 00:00:00 2001 From: Samuel Martin Date: Sun, 14 Dec 2014 18:45:54 +0100 Subject: [PATCH] package/librtlsdr: fix build failure Disable run test for pthread detection. In case of build with only static library, CMake fails to detect the pthread library (-lpthread), so it falls back trying to link using -pthread and execute the test program. [...] -- Looking for include file pthread.h -- Looking for include file pthread.h - found -- Looking for pthread_create in pthreads -- Looking for pthread_create in pthreads - not found -- Looking for pthread_create in pthread -- Looking for pthread_create in pthread - not found -- Check if compiler accepts -pthread CMake Error: TRY_RUN() invoked in cross-compiling mode, please set the following cache variables appropriately: THREADS_PTHREAD_ARG (advanced) For details see /home/buildroot/instance-1/output/build/librtlsdr-v0.5.3/TryRunResults.cmake -- Check if compiler accepts -pthread - no -- Found Threads: TRUE -- Udev rules not being installed, install them with -DINSTALL_UDEV_RULES=ON -- Building with kernel driver detaching disabled, use -DDETACH_KERNEL_DRIVER=ON to enable -- Building for version: 0.5.3 / 0.5.3 -- Using install prefix: /usr -- Configuring incomplete, errors occurred! See also "/home/buildroot/instance-1/output/build/librtlsdr-v0.5.3/CMakeFiles/CMakeOutput.log". See also "/home/buildroot/instance-1/output/build/librtlsdr-v0.5.3/CMakeFiles/CMakeError.log". Here it fails because, in the CMake FindThreads.cmake file, the 'try_run' function is unconditionally called [1]. Also, the CMakeError.log gives more details why linking with -lpthread fails: [...] Run Build Command:"/usr/bin/make" "cmTryCompileExec3012181287/fast" make[1]: Entering directory '/home/buildroot/instance-1/output/build/librtlsdr-v0.5.3/CMakeFiles/CMakeTmp' /usr/bin/make -f CMakeFiles/cmTryCompileExec3012181287.dir/build.make CMakeFiles/cmTryCompileExec3012181287.dir/build make[2]: Entering directory '/home/buildroot/instance-1/output/build/librtlsdr-v0.5.3/CMakeFiles/CMakeTmp' /home/buildroot/instance-1/output/host/usr/bin/cmake -E cmake_progress_report /home/buildroot/instance-1/output/build/librtlsdr-v0.5.3/CMakeFiles/CMakeTmp/CMakeFiles 1 Building C object CMakeFiles/cmTryCompileExec3012181287.dir/CheckFunctionExists.c.o /home/buildroot/instance-1/output/host/usr/bin/arm-linux-gcc -pipe -Os -static -DCHECK_FUNCTION_EXISTS=pthread_create -o CMakeFiles/cmTryCompileExec3012181287.dir/CheckFunctionExists.c.o -c /home/buildroot/instance-1/output/host/usr/share/cmake-3.0/Modules/CheckFunctionExists.c Linking C executable cmTryCompileExec3012181287 /home/buildroot/instance-1/output/host/usr/bin/cmake -E cmake_link_script CMakeFiles/cmTryCompileExec3012181287.dir/link.txt --verbose=1 /home/buildroot/instance-1/output/host/usr/bin/arm-linux-gcc -pipe -Os -static -DCHECK_FUNCTION_EXISTS=pthread_create -static CMakeFiles/cmTryCompileExec3012181287.dir/CheckFunctionExists.c.o -o cmTryCompileExec3012181287 -rdynamic -lpthread -Wl,-Bstatic -lusb-1.0 -Wl,-Bdynamic /home/buildroot/instance-1/output/host/usr/arm-buildroot-linux-uclibcgnueabi/sysroot/usr/lib/libpthread.a(init.os): In function `__pthread_initialize_minimal': init.c:(.text+0x270): undefined reference to `__libc_setup_tls' collect2: error: ld returned 1 exit status CMakeFiles/cmTryCompileExec3012181287.dir/build.make:89: recipe for target 'cmTryCompileExec3012181287' failed make[2]: *** [cmTryCompileExec3012181287] Error 1 make[2]: Leaving directory '/home/buildroot/instance-1/output/build/librtlsdr-v0.5.3/CMakeFiles/CMakeTmp' Makefile:118: recipe for target 'cmTryCompileExec3012181287/fast' failed make[1]: *** [cmTryCompileExec3012181287/fast] Error 2 make[1]: Leaving directory '/home/buildroot/instance-1/output/build/librtlsdr-v0.5.3/CMakeFiles/CMakeTmp' Determining if compiler accepts -pthread returned PLEASE_FILL_OUT-FAILED_TO_RUN instead of 2. The compiler had the following output: Change Dir: /home/buildroot/instance-1/output/build/librtlsdr-v0.5.3/CMakeFiles/CMakeTmp Run Build Command:"/usr/bin/make" "cmTryCompileExec1361818630/fast" make[1]: Entering directory '/home/buildroot/instance-1/output/build/librtlsdr-v0.5.3/CMakeFiles/CMakeTmp' /usr/bin/make -f CMakeFiles/cmTryCompileExec1361818630.dir/build.make CMakeFiles/cmTryCompileExec1361818630.dir/build make[2]: Entering directory '/home/buildroot/instance-1/output/build/librtlsdr-v0.5.3/CMakeFiles/CMakeTmp' /home/buildroot/instance-1/output/host/usr/bin/cmake -E cmake_progress_report /home/buildroot/instance-1/output/build/librtlsdr-v0.5.3/CMakeFiles/CMakeTmp/CMakeFiles 1 Building C object CMakeFiles/cmTryCompileExec1361818630.dir/CheckForPthreads.c.o /home/buildroot/instance-1/output/host/usr/bin/arm-linux-gcc -pipe -Os -static -o CMakeFiles/cmTryCompileExec1361818630.dir/CheckForPthreads.c.o -c /home/buildroot/instance-1/output/host/usr/share/cmake-3.0/Modules/CheckForPthreads.c Linking C executable cmTryCompileExec1361818630 /home/buildroot/instance-1/output/host/usr/bin/cmake -E cmake_link_script CMakeFiles/cmTryCompileExec1361818630.dir/link.txt --verbose=1 /home/buildroot/instance-1/output/host/usr/bin/arm-linux-gcc -pipe -Os -static -static CMakeFiles/cmTryCompileExec1361818630.dir/CheckForPthreads.c.o -o cmTryCompileExec1361818630 -rdynamic -pthread make[2]: Leaving directory '/home/buildroot/instance-1/output/build/librtlsdr-v0.5.3/CMakeFiles/CMakeTmp' make[1]: Leaving directory '/home/buildroot/instance-1/output/build/librtlsdr-v0.5.3/CMakeFiles/CMakeTmp' While falling back on -pthread is correct when using only static libraries to get some tls-related macros defined [2,3], it is wrong to try to run the test program in case of cross-compilation. So, this patch only disable run test when pthread support is done using -pthread, i.e. in case of the type of libraries is "static only". Fixes: http://autobuild.buildroot.org/results/26c/26cb8c2e5f867d49451f61304bf0a1a6f7b825d9/ [1] http://www.cmake.org/gitweb?p=cmake.git;a=blob;f=Modules/FindThreads.cmake;h=a0bc4d133eb3f9d3ae096f0e03e419ef7be66ce8;hb=HEAD#l84 [2] http://lists.busybox.net/pipermail/buildroot/2014-June/100690.html [3] http://stackoverflow.com/questions/23250863/difference-between-pthread-and-lpthread-while-compiling Signed-off-by: Samuel Martin Cc: Baruch Siach Cc: Thomas Petazzoni Signed-off-by: Peter Korsgaard --- package/librtlsdr/librtlsdr.mk | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/package/librtlsdr/librtlsdr.mk b/package/librtlsdr/librtlsdr.mk index 2c5cf1ffce..51ecabe14a 100644 --- a/package/librtlsdr/librtlsdr.mk +++ b/package/librtlsdr/librtlsdr.mk @@ -19,4 +19,15 @@ ifeq ($(BR2_PACKAGE_LIBRTLSDR_DETACH_DRIVER),y) LIBRTLSDR_CONF_OPTS += -DDETACH_KERNEL_DRIVER=1 endif +# In case of static-lib-only builds, CMake's FindThreads.cmake code tries to +# get the right flags, checking first for -lpthreads, then -lpthread, and lastly +# for -pthread. +# The 2 first link checks fail because of undefined symbols: __libc_setup_tls. +# In the later check, CMake successfully compiles and links the test program, +# but it also tries to run it, which is wrong when cross-compiling. +# +# The following CMake variable only disables the TRY_RUN call in the -pthread +# test. +LIBRTLSDR_CONF_OPTS += -DTHREADS_PTHREAD_ARG=OFF + $(eval $(cmake-package)) -- 2.30.2