undefined symbol aligned_free / aligned_malloc

[JohnKafe]

I have added an external lib to my project and when compiling it, I get some linking error (I'm compiling with C99 extension and I need to keep it) :

To be honest, even if the error seems basic, I'm totally lost. The header where aligned_free/ aligned_malloc are referenced say this : 

/*
 * NOTE: MSVC in general has no aligned alloc function that is
 * compatible with free and it is not trivial to implement a version
 * which is. Therefore, to remain portable, end user code needs to
 * use `aligned_free` which is not part of C11 but defined in this header.
 *
 * glibc only provides aligned_alloc when _ISOC11_SOURCE is defined, but
 * MingW does not support aligned_alloc despite of this, it uses the
 * the _aligned_malloc as MSVC.
 *
 * The same issue is present on some Unix systems not providing
 * posix_memalign.
 *
 * Note that clang and gcc with -std=c11 or -std=c99 will not define
 * _POSIX_C_SOURCE and thus posix_memalign cannot be detected but
 * aligned_alloc is not necessarily available either. We assume
 * that clang always has posix_memalign although it is not strictly
 * correct. For gcc, use -std=gnu99 or -std=gnu11 or don't use -std in
 * order to enable posix_memalign, or live with the fallback until using
 * a system where glibc has a version that supports aligned_alloc.
 *
 * For C11 compliant compilers and compilers with posix_memalign,
 * it is valid to use free instead of aligned_free with the above
 * caveats.
 */

If I dont miss, LabWindows/CVI is based on clang. So why I got this error ? Help !

[JohnKafe · Accepted solution]

Well, to fix this issue, I had to compile flatcc Using clang (a true Clang installation, not the NI one) in 32bit. To do this, I moved into flatcc directory and did :

cmake -G "MinGW Makefiles" -DCMAKE_C_COMPILER=x86_64-w64-mingw32-c99 -DFLATCC_PORTABLE=true -DFLATCC_ALLOW_WERROR=false -DBUILD_TESTING=false -DFLATCC_CXX_TEST=false -DFLATCC_REFLECTION=false -DFLATCC_USE_GENERIC_ALIGNED_ALLOC -B .

Then edited flatcc\src\compiler\CMakeFiles\flatcc.dir\flags.make and flatcc\src\runtime\CMakeFiles\flatcc.dir\flags.make to add -m32 to C_FLAGS :

C_FLAGS = -m32 -DFLATCC_REFLECTION=0 -Wstrict-prototypes -Wsign-conversion -Wconversion -std=c11 -pedantic -Wall -Wextra -DFLATCC_PORTABLE -DFLATCC_USE_GENERIC_ALIGNED_ALLOC

Then changed flatcc\src\compiler\CMakeFiles\flatcc.dir\link.txt and flatcc\src\runtime\CMakeFiles\flatcc.dir\link.txt to look like this :

...\bin\clang\bin\ar.exe rc ..\..\..\lib\flatcc.lib  CMakeFiles/flatcc.dir/__/__/external/hash/cmetrohash64.c.obj ...
...bin\clang\bin\ranlib.exe ..\..\..\lib\flatcc.lib

Note: I just changed name of .a generated to .lib

Then finally I run mingw32-make.exe (or make.exe)

The two .lib generated work with labWindows/Cvi (c99)