Re: __STRICT_ANSI__ "fixes" on STDC_0_IN_SYSTEM_HEADERS (solaris) targets

["Kaveh R. Ghazi" <ghazi at caipclassic dot rutgers dot edu>]

 > Let's not go down the road of including the target config file in
 > more places which are not part of the compiler proper - which are
 > not even inside the gcc directory!

I agree, but I also want to avoid duplicating the info in two places,
it makes maintenance harder.


 > I'd like to see this used as an occasion to determine whether we
 > still need this particular hack, which I have never been fond of.

Which hack?  The STDC_0_IN_SYSTEM_HEADERS hack, or the strict_ansi_*
fixincludes hacks?  Or both?  I'm pretty sure solaris10 no longer
needs either one, but older releases of solaris do.  I can't speak for
other svr4 targets or interix.  My concern is that we should be
consistent, since applying the fixincludes hacks depends on not having
stdc_0_in_system_headers.


 > If we really still do, the Right Thing would be to add another
 > undocumented built-in preprocessor macro,
 > __STDC_0_IN_SYSTEM_HEADERS__ say, which is defined only if
 > CPP_OPTION(pfile, stdc_0_in_system_headers) is true.
 > zw

I don't see how this will work given that fixincludes is built with
the bootstrap compiler in 4.0 and 4.1 which has no notion of your new
macro __STDC_0_IN_SYSTEM_HEADERS__.

For 4.2 and later, while fixincludes is three-staged, we'll still have
problems in stage1 fixincludes or with --disable-bootstrap
configurations using your scheme.


Another option might be to use the resulting gcc compiler just built
and compile an autoconf style check to see whether system headers
define __STDC__ to 1.  We can create a testcase that fakes being in a
system header by using those digits in the line number directives
right?  I forget the format, but I seem to recall one of the trailing
digits signifies we're in a system header.  Then just see if you can
compile this:

# fake us into system header land...
#if __STDC__ - 0 == 0
#error "STDC_0_IN_SYSTEM_HEADERS"
#endif

If it fails, then fixincludes knows we have stdc_0_in_system_headers.

		--Kaveh
--
Kaveh R. Ghazi			ghazi@caip.rutgers.edu