CMake: The C Compiler is not able to compile a simple test program [duplicate]

Question

I am trying to cross-compile the Azure IoT SDK C for a Mips processor. Cross-compiling an older version of the same SDK using an older version of CMake (2.8.12.2) works just fine, so I doubt it's the code itself. I am guessing it's the Mips GCC compiler.

Error message:

CMake Error at /usr/share/cmake-3.10/Modules/CMakeTestCCompiler.cmake:52 (message):
  The C compiler

    "/usr/local/mipsisa32r2el/r23/bin/mipsisa32r2el-axis-linux-gnu-gcc"

  is not able to compile a simple test program.

  It fails with the following output:

    Change Dir: /home/axis/azure-iot-sdk-c/cmake/iotsdk_linux/CMakeFiles/CMakeTmp
    
    Run Build Command:"/usr/bin/make" "cmTC_2cc84/fast"
    /usr/bin/make -f CMakeFiles/cmTC_2cc84.dir/build.make CMakeFiles/cmTC_2cc84.dir/build
    make[1]: Entering directory '/home/axis/azure-iot-sdk-c/cmake/iotsdk_linux/CMakeFiles/CMakeTmp'
    Building C object CMakeFiles/cmTC_2cc84.dir/testCCompiler.c.o
    /usr/local/mipsisa32r2el/r23/bin/mipsisa32r2el-axis-linux-gnu-gcc --sysroot=/usr/local/mipsisa32r2el/r23    -o CMakeFiles/cmTC_2cc84.dir/testCCompiler.c.o   -c /home/axis/azure-iot-sdk-c/cmake/iotsdk_linux/CMakeFiles/CMakeTmp/testCCompiler.c
    Linking C executable cmTC_2cc84
    /usr/bin/cmake -E cmake_link_script CMakeFiles/cmTC_2cc84.dir/link.txt --verbose=1
    /usr/local/mipsisa32r2el/r23/bin/mipsisa32r2el-axis-linux-gnu-gcc --sysroot=/usr/local/mipsisa32r2el/r23      -rdynamic CMakeFiles/cmTC_2cc84.dir/testCCompiler.c.o  -o cmTC_2cc84 
    /usr/local/mipsisa32r2el/r23/lib/gcc/mipsisa32r2el-axis-linux-gnu/4.7.2/../../../../mipsisa32r2el-axis-linux-gnu/bin/ld: this linker was not configured to use sysroots
    collect2: error: ld returned 1 exit status
    CMakeFiles/cmTC_2cc84.dir/build.make:97: recipe for target 'cmTC_2cc84' failed
    make[1]: *** [cmTC_2cc84] Error 1
    make[1]: Leaving directory '/home/axis/azure-iot-sdk-c/cmake/iotsdk_linux/CMakeFiles/CMakeTmp'
    Makefile:126: recipe for target 'cmTC_2cc84/fast' failed
    make: *** [cmTC_2cc84/fast] Error 2
    

Unfortunately, I am stuck with the Mips GCC compiler I have. Is there a way to disable this test-program check?

Calycine

"Is there a way to disable this test-program check?" - Yes. Easily googled: #10599538 – Circinate

@Circinate Ignored it because the accepted answer is from 2012 with no usable answer, but down at the bottom there's a line that seems to disable it. – Calycine

If your last paragraph has intention answer your question, then it is not right place for it: on Stack Overflow we tend to separate question and answer posts. Instead, you may your answer it into the answer post: on Stack Overflow self-answering is perfectly acceptible. – Circinate

@Circinate I know, but thought the 48 period also applied to posting it, not just to accepting it. Also someone might have a better solution, or just one with an explanation. – Calycine

Answer 1

CMake tries to compile an executable using "standard" (as per what CMake thinks is standard) compiler options and tries to run that executable, so to see if the compiler is working. The executable is simple like int main(int argc, char *argv[]) { return argc - 1; }.

You can't do that when cross-compiling. Because usually you can't link with a proper C standard library, you don't have printf, or _start or _exit or similar, passing arguments to main is implementation-defined, or you need a special linker script, or there's no emulator for your architecture, so can't run cross-compiled source on the host, etc... Simply: you usually can't run the cross-compiled executable on the host, and most of the time even the compilation is hard enough to do.

The common solution is to set before project():

set(CMAKE_TRY_COMPILE_TARGET_TYPE "STATIC_LIBRARY")

So that CMake will try to compile a static library not an executable, as explained in cmake docs CMAKE_TRY_COMPILE_TARGET_TYPE. This avoids running the linker and is intended for cross-compiling.

You can set CMAKE_C_COMPILER_WORKS and it will omit the check in CMakeTestCCompiler.cmake, but CMAKE_TRY_COMPILE_TARGET_TYPE is a more proper solution.

Erikerika

Ah, that makes more sense then. Thought it might have been because the compiler was from ~2016, but, yeah, if it has trouble linking C libraries that would explain it. Thanks! – Calycine

try_compile() does not try to execute the program but setting CMAKE_TRY_COMPILE_TARGET_TYPE is useful because you can avoid the linking step that is performed by CMakeTestCCompiler.cmake as you cannot easily add any special linker flags used by the CMakeLists.txt at this point. – Middendorf

in this case it looks like --sysroot=/usr/local/mipsisa32r2el/r23 is not a valid linker option and is causing the failure. – Middendorf

Note that if you set CMAKE_TRY_COMPILE_TARGET_TYPE to STATIC_LIBRARY, CMAKE_SIZEOF_VOID_P will not be calculated/set, which many CMake scripts depend on. – Kania

Got this error after upgrading to Ubuntu 18.04.2, your suggestion solved it, thanks! – Hendon

Hey. Just up-voting because of your helpful comment here – Unfailing

Answer 2

Ran into the same problem while re-compiling a project. Turned out that the compiler had been updated in the meantime.

After removing the build directory and creating it again, the compilation completed without errors.

Aube

This not worked, but when I read this, I realised that the problem is caused by copying CMake settings from antoher computer (settings for macOS moved to Windows)... – Cointreau

This was the resolution for me. – Attire

Answer 3

If using CMake GUI, you can add a boolean entry named

CMAKE_CXX_COMPILER_FORCED

then set it to True.

This will skip checking process for this build.

Hibbert

Answer 4

In my case it turned out that the path on my windows machine was too long. Shortened it and everything worked as expected.

Bluegreen

Answer 5

Well this problem is really annoying, i faced this issue for 2 day now I got solution.

Let me explain my issue first

When I delete NDK and Cmake from Sdk folder and Run my application then grable install NDK and Cmake again. Only that time Application run and when try to run again i get this error The C Compiler is not able to compile a simple test program.

Before i was using ndkVersion "22.0.7026061" then change to thisndkVersion "21.1.6352462" and IT WORKED.

I think this is NDK problem and most of answer are outdated try this i hope this will HELP.

Need

Answer 6

In my case while working on ESP32-IDF Tools, Creating a project first and changing the directory from "CMakeTmp" to the created project directory resolved the problem. hope to help others.

idf.py create-project myproject
cd myproject

Shuffleboard