cmake build generates an (almost) empty config.h
$ cmake ~/dev/Opus
$ cat opus/config.h
#define PACKAGE_VERSION "1.3.1-91-g7b05f44f"
while the ./configure generated one has over 200 lines.
Maybe only some of the defines are missing, like CPU_INFO_BY_C / ASM:
$ grep -R CPU_INFO_BY_C .
$ grep -R CPU_INFO_BY_ASM .
$ grep -r OPUS_X86_MAY_HAVE_AVX .
./CMakeCache.txt:OPUS_X86_MAY_HAVE_AVX:BOOL=ON
./opus/CMakeFiles/opus.dir/flags.make:C_DEFINES = -DENABLE_ASSERTIONS -DENABLE_HARDENING -DHAVE_ALLOCA_H -DHAVE_CONFIG_H -DOPUS_BUILD -DOPUS_HAVE_RTCD -DOPUS_X86_MAY_HAVE_AVX -DOPUS_X86_MAY_HAVE_SSE -DOPUS_X86_MAY_HAVE_SSE2 -DOPUS_X86_MAY_HAVE_SSE4_1 -DOPUS_X86_PRESUME_SSE -DOPUS_X86_PRESUME_SSE2 -DVAR_ARRAYS -D_FORTIFY_SOURCE=2
./opus/CMakeFiles/opus.dir/DependInfo.cmake: "OPUS_X86_MAY_HAVE_AVX"
Neither of CPU_INFO_BY_C and CPU_INFO_BY_ASM is defined:
[ 84%] Building C object opus/CMakeFiles/opus.dir/celt/x86/x86cpu.c.o
~/dev/Opus/opus/celt/x86/x86cpu.c: In function ‘cpuid’:
~/dev/Opus/opus/celt/x86/x86cpu.c:58:32: warning: unused parameter ‘CPUInfo’ [-Wunused-parameter]
58 | static void cpuid(unsigned int CPUInfo[4], unsigned int InfoType)
| ~~~~~~~~~~~~~^~~~~~~~~~
~dev/Opus/opus/celt/x86/x86cpu.c:58:57: warning: unused parameter ‘InfoType’ [-Wunused-parameter]
58 | static void cpuid(unsigned int CPUInfo[4], unsigned int InfoType)
| ~~~~~~~~~~~~~^~~~~~~~