gnattest can be used to generate the test harness for platforms and run-time libraries others than the default native target with the default full run-time. For example, when using a limited run-time library such as Zero FootPrint (ZFP), a simplified harness is generated.
Two variables are used to tell the underlying AUnit framework how to generate
the test harness: PLATFORM, which identifies the target, and
RUNTIME, used to determine the run-time library for which the harness
is generated. Corresponding prefix should also be used when calling
gnattest for non-native targets. For example, the following options
are used to generate the AUnit test harness for a PowerPC ELF target using
the ZFP run-time library:
powerpc-elf-gnattest -Psimple.gpr -XPLATFORM=powerpc-elf -XRUNTIME=zfp