I think it should not use CFLAGS to build ada files /usr/bin/gcc-10.3.1 -c -x ada -gnatA -g -gnatg -O0 -gnata -gnatVa -gnat2020 -Os -pipe -march=native -fdiagnostics-color=always -frecord-gcc-switches -fexceptions -fstack-clash-protection -fcf-protection=full -fasynchronous-unwind-tables -ftree-vectorize -Waddress -Waggressive-loop-optimizations -Warray-bounds -Wclobbered -Wdate-time -Wformat -Wformat-security -Wfree-nonheap-object -Wnonnull -Wparentheses -Wpointer-arith -Wreturn-local-addr -Wsizeof-pointer-memaccess -Wstrict-aliasing -Wuninitialized -Wunused-value -Wvolatile-register-var -Wno-error=implicit-function-declaration -Wimplicit-function-declaration -gnatec=/var/tmp/portage/dev-lang/spark-2021/temp/GNAT-TEMP-000007.TMP -gnatec=/var/tmp/portage/dev-lang/spark-2021/work/spark-2021-2021-20210519-19A1A-src/gnat2why/devel.adc -gnatec=/var/tmp/portage/dev-lang/spark-2021/work/spark-2021-2021-20210519-19A1A-src/gnat2why/gnat.adc -gnatem=/var/tmp/portage/dev-lang/spark-2021/temp/GNAT-TEMP-000018.TMP /var/tmp/portage/dev-lang/spark-2021/work/spark-2021-2021-20210519-19A1A-src/gnat2why/gnat_src/fname.adb gnat1: warning: command-line option ‘-Waddress’ is valid for C/C++/D/ObjC/ObjC++ but not for Ada gnat1: warning: command-line option ‘-Wclobbered’ is valid for C/C++/ObjC/ObjC++ but not for Ada gnat1: warning: command-line option ‘-Wdate-time’ is valid for C/C++/Fortran/ObjC/ObjC++ but not for Ada gnat1: warning: command-line option ‘-Wformat=1’ is valid for C/C++/ObjC/ObjC++ but not for Ada gnat1: warning: command-line option ‘-Wformat-security’ is valid for C/C++/ObjC/ObjC++ but not for Ada gnat1: warning: command-line option ‘-Wnonnull’ is valid for C/C++/LTO/ObjC/ObjC++ but not for Ada gnat1: warning: command-line option ‘-Wparentheses’ is valid for C/C++/ObjC/ObjC++ but not for Ada gnat1: warning: command-line option ‘-Wpointer-arith’ is valid for C/C++/ObjC/ObjC++ but not for Ada gnat1: warning: command-line option ‘-Wsizeof-pointer-memaccess’ is valid for C/C++/ObjC/ObjC++ but not for Ada gnat1: warning: command-line option ‘-Wvolatile-register-var’ is valid for C/C++/ObjC/ObjC++ but not for Ada gnat1: warning: command-line option ‘-Wimplicit-function-declaration’ is valid for C/ObjC but not for Ada