On Fri, Feb 20, 2004 at 07:39:28PM +0000, Jonathan Watt wrote:
> Claudio Bley wrote:
>
>The part I quoted just shows where the gcc that came with my Debian
> >distribution searches for header files by default. Redhat's default gcc
> >should behave the same. It just demonstrates that by default
> >/usr/local/include is also searched for header files.
>
> I see, do you know why is it that when I use -v for an empty file I get
> the following search paths:
>
> #include <...> search starts here:
> /usr/local/include
> /home/jwatt/gcc/include
> /home/jwatt/gcc/lib/gcc-lib/i686-pc-linux-gnu/3.2.3/include
> /usr/include
>
> but when I use -v on an actual C++ file I get more search paths,
> specifically the following:
>
> #include <...> search starts here:
> /home/jwatt/gcc/include/c++/3.2.3
> /home/jwatt/gcc/include/c++/3.2.3/i686-pc-linux-gnu
> /home/jwatt/gcc/include/c++/3.2.3/backward
> /usr/local/include
> /home/jwatt/gcc/include
> /home/jwatt/gcc/lib/gcc-lib/i686-pc-linux-gnu/3.2.3/include
> /usr/include
If GCC is reading from standard input it can't determine the source code
type opposed to when reading a real source file where it does deduce the
source code type from the file name extension. By default GCC assumes C code
as input when it can't decuce it automatically and the user hasn't passed
the -x <language> option to GCC.
So, to force GCC to treat the code on its standard input as C++ code:
$ cat /dev/null | gcc -x c++ -E -v -
OR just use g++ when executing the command as it calls GCC with the default
language set to C++.
> Thanks for all that Claudio.
No problem. :-)
Cheers.
--
Claudio Bley ASCII ribbon campaign (")
Debian GNU/Linux user - against HTML email X
http://www.cs.uni-magdeburg.de/~bley/ & vCards / \
