here is a snippet of the message including error information:
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gcc -c -DHAVE_CONFIG_H -g -fkeep-inline-functions -I. -I../.././libiberty/../include -W -Wall -Wwrite-strings -Wstrict-prototypes -pedantic ../.././libiberty/pex-common.c -o pex-common.o
../.././libiberty/pex-common.c: In function `pex_input_file':
../.././libiberty/pex-common.c:390: error: `EINVAL' undeclared (first use in this function)
../.././libiberty/pex-common.c:390: error: (Each undeclared identifier is reported only once
../.././libiberty/pex-common.c:390: error: for each function it appears in.)
../.././libiberty/pex-common.c: In function `pex_input_pipe':
../.././libiberty/pex-common.c:453: error: `EINVAL' undeclared (first use in this function)
make[3]: *** [pex-common.o] error 1
make[3]: Leaving directory `/usr/src/gcc-4.4.0/host-i686-pc-linux-gnu/libiberty'
make[2]: *** [all-stage1-libiberty] error 2
make[2]: Leaving directory `/usr/src/gcc-4.4.0'
make[1]: *** [stage1-bubble] error 2
make[1]: Leaving directory `/usr/src/gcc-4.4.0'
make: *** [all] error 2
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RHEL 4, kernel 2.6.9-22
this happened when I trying upgrading the GCC
who know how to resolve this problem?
thank you very much!!

Did you try "yum update gcc" in a root-shell before compiling this from source? I mean, compiling from source can be a pain, while using the package manager of your distro is usually more straightforward (also in terms of dependencies between software packages).

If you have further questions (like, "what is a distro?", "package manager?" ...), I suggest refering to e.g. google (like here: google search for "redhat update package" <- that's where I found the "yum update <package>" command), and if you still don't manage to update your GCC, asking here.

It looks like you do not have the standard headers installed.

To build gcc, a build directory is required.

The recommended build method is described here
http://www.linuxfromscratch.org/lfs/view/6.4/

http://www.linuxfromscratch.org/lfs/...gcc-pass1.html
http://www.linuxfromscratch.org/lfs/...ter06/gcc.html
.....
.....
And gcc 4.x is available with yum :
# yum install gcc4 gcc4-c++ gcc4-gfortran
provides version 4.1.2 .
.....
Using multiple compilers, examples :
sh configure CC=gcc4 CXX=g++4
make CC=gcc4 CXX=g++4
.....

thanks you for your guide.
To use "yum",I have to make sure my PC is connected to the internet,which I can't.
because I access the internet via ADSL. and the ISP doesn't supply the Connecting software for Linux.

I assume you downloaded a source ball (a *.tar.gz file or similar). You can still use the package manager of Red Hat to install a package you download from somewhere, it just has to be in RPM format. I don't know a good source for RPM packages, though.

I guess, you can use these, which I got installed
on CentOS 4.x ( = Redhat EL 4 ) :

gcc4-4.1.2-42.EL4.i386.rpm
gcc4-c++-4.1.2-42.EL4.i386.rpm
gcc4-gfortran-4.1.2-42.EL4.i386.rpm
libgfortran-4.1.2-42.EL4.i386.rpm
from
http://mirror.centos.org/centos/4.7/...6/CentOS/RPMS/
.....