signed is undefined and has been since 1992 (in GCC)

[Robert Dewar]

Gabriel Dos Reis wrote:

>  C is
> trustworthy (and preferred over SML for that curcial part of the proof
> checker) because the mapping of the C code to the generated assembly
> code is straighforward and amenable to inspection.

This kind of traceability is of course vital for such applications, but
it is by no means unique to C, and there is a big difference between saying
that C is an assembly language, and that the mapping of C to assembly
language is transparent.

The latter quality incidentally, Tucker Taft describes as WYSIWYG for
programming languages, and it is an important design point for C I
would say, and indeed was an important design principle for Ada.