c/1609: -funsigned-char -fsigned-char defines __CHAR_UNSIGNED__

[Joseph Myers]

>Number:         1609
>Category:       c
>Synopsis:       -funsigned-char -fsigned-char defines __CHAR_UNSIGNED__
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    unassigned
>State:          open
>Class:          wrong-code
>Submitter-Id:   net
>Arrival-Date:   Wed Jan 10 11:56:00 PST 2001
>Closed-Date:
>Last-Modified:
>Originator:     Joseph S. Myers
>Release:        2.97 20010110 (experimental)
>Organization:
none
>Environment:
System: Linux decomino 2.2.18 #1 Sun Jan 7 21:04:55 UTC 2001 i686 unknown
Architecture: i686

	
host: i686-pc-linux-gnu
build: i686-pc-linux-gnu
target: i686-pc-linux-gnu
configured with: ../gcc-cvs/configure --prefix=/opt/gcc/snapshot --disable-shared --enable-threads=posix --with-system-zlib
>Description:

This is a PR to track an issue previously reported on gcc-bugs
<URL: http://gcc.gnu.org/ml/gcc-bugs/2000-11/msg00545.html >.  When
-funsigned-char -fsigned-char is used on a system with signed chars,
chars are signed but __CHAR_UNSIGNED__ is defined.

>How-To-Repeat:

See message cited.

>Fix:

Either leave until specs / option parsing get redesigned, or kludge
something so that the existing code that knows (when handling specs)
that -f<foo> and -fno-<foo> are opposites also knows that
-fsigned-char and -funsigned-char are opposites (and similarly,
-ffreestanding and -fhosted, with similar problems associated with
__STDC_HOSTED__).
>Release-Note:
>Audit-Trail:
>Unformatted: