the mystery of math.h in lib/gcc/%triple-name%/%gcc-version%/include-fixed

[Jonathan Wakely]

On Wed, 24 Oct 2018 at 04:25, Dennis Clarke <dclarke@blastwave.org> wrote:
> The question has to be where do these "include-fixed" headers come
> from?

The include-fixed headers are generated as part of the GCC build
process. The contents of the fixincludes dir in the GCC sources apply
a set of rules to fix known problems in the system headers (either
conformance bugs, or incompatibilities with GCC). That means the
include-fixed files are specific to the machine they were created for
(and any machines with the same set of headers).

> I am looking for an end point result that I know I can drop
> on any similar machine and it will "just work"(tm).

Generally "any similar machine" won't work, it needs to be exactly the
same, because otherwise differences in the libc headers cause this
kind of problem.