c++/5997: CPLUS_INCLUDE_PATH not working properly

[Jorgo Bakker]

The following reply was made to PR c++/5997; it has been noted by GNATS.

From: Jorgo Bakker <jbakker@rssd.esa.int>
To: Zack Weinberg <zack@codesourcery.com>
Cc: Neil Booth <neil@daikokuya.demon.co.uk>, gcc-gnats@gcc.gnu.org,
	 gcc-bugs@gcc.gnu.org
Subject: Re: c++/5997: CPLUS_INCLUDE_PATH not working properly
Date: Tue, 19 Mar 2002 11:02:05 +0100

 Zack Weinberg wrote:
 
 > Oh! I see what the problem is now.
 >
 > > . /data/Users/jbakker/tmp/gcc-bug/foo/tmp/include/foo.h
 > > In file included from main.cc:1:
 > > /data/Users/jbakker/tmp/gcc-bug/foo/tmp/include/foo.h:5: declaration of C
 > >    function `void handle(float)' conflicts with
 > > /data/Users/jbakker/tmp/gcc-bug/foo/tmp/include/foo.h:4: previous declaration
 > >    `void handle(int)' here
 >
 > It is reading the header file you asked it to, but interpreting that
 > file as a "system header" - and on sparc-sun-solaris2.x, "system
 > headers" get treated as wrapped in an implicit extern "C".
 >
 > I'm not inclined to change what *_INCLUDE_PATH do - there are probably
 > people out there depending on having them be system headers.  You can
 > work around the problem by putting extern "C++" { ... } around the
 > entire content of your header file.
 >
 > Also, the sparc-sun-solaris* configurations should probably be changed
 > to disable the implicit extern "C".  If I remember correctly, Solaris
 > has had extern "C" in its header files from day one.
 >
 > zw
 
 I have been using GCC from version 2.7 onwards (including many flavours of it in
 terms of EGCS), and with the introduction of GCC-3 the behavior of
 CPLUS_INCLUDE_PATH has changed. As you have noticed, GCC-3 behaves different on
 Linux.
 
 Your recommendations about changing the sparc-sun-solaris* configs would do the
 trick. To me it seems that C_INCLUDE_PATH is reserved for C-header files ;-)
 
 Hope to see this 'solaris specific feature' disappearing in future.
 
 Cheers - Jorgo