[Pkg-cmake-team] Bug#789807: [alpha] cmake: testsuite failure: compiler feature "c_function_prototypes" is not known to C compiler

[Bob Tracy]

I think I may have found the issue.  Not sure if other architectures
could be affected.

Looking at the cmake build artifacts under the "Build" directory, there
are several instances of "feature_tests.c" and "feature_tests.cxx" with
"const char features[]" initialized to '{ "" ... }' where I'm reasonably
certain the intent is for the first byte of the "features" array to be a
NULL.  When "strings" is run on the resulting ".bin" file to extract the
tokens of interest, there's no leading NULL byte in front of what is
supposed to be the first non-NULL character in "features": that's where
the mysterious leading "k" is coming from, and why only the first token
in the array is "corrupted" in that manner.  In other words, whichever
feature appears first in the "const char features[]" array is going to
be the one flagged as not supported.

Replacing "" with "\0" correctly produces the intended NULL byte at the
start of the array, and ultimately allows a working "cmake" to be built
on Alpha.

The question then is whether "" is supposed to compile to a NULL byte in
the context of the "const char features[]" array, and whether this
compiler behavior applies to other architectures.  My fear is that we're
simply getting lucky on x86, and any NULL in front of the array is there
by accident.

Not sure where/how to apply a proper fix.

--Bob