Add properties and variables corresponding to CXX equivalents.
Add features for c_function_prototypes (C90), c_restrict (C99),
c_variadic_macros (C99) and c_static_assert (C11). This feature
set can be extended later.
Add a <PREFIX>_RESTRICT symbol define to WriteCompilerDetectionHeader
to conditionally represent the c_restrict feature.
In CMakeDetermineCompilerABI we use try_compile with the COPY_FILE
option to get a copy of the compiled binary used to detect the ABI
information. We already tolerate the case when compilation fails.
However, when compilation appears to succeed but does not produce the
expected executable the try_compile command immediately reports an error
because the COPY_FILE fails.
Tolerate COPY_FILE failure without stopping the overall configuration
process by using the try_compile COPY_FILE_ERROR option to capture the
error message. Log the full error to CMakeError.log and simply report
failure to detect the ABI as if compilation had failed.
Teach the RunCMake.Configure test to cover this case and verify that the
messages show up as expected both in stdout and in CMakeError.log.
Stephen Kelly
Brad King