Problems when installing OPEN-MPI - c++

Question

I got some errors when I try to ./configure --prefix=/usr/local
Installed a bunch of stuff and openmpi versions, but they didn't work. I think previously this command worked, but after following different tuts, it gives errors.
Terminal is in the openmpi folder.
Help? ) Thank you in advance.
Terminal result:
checking for gcc... gcc
checking whether the C compiler works... yes
checking for C compiler default output file name... a.out checking
for suffix of executables... checking whether we are cross
compiling... configure: error: in
`/Users/maximgavrilov/Documents/temp/openmpi-4.0.0': configure:
error: cannot run C compiled programs. If you meant to cross compile,
use `--host'. See `config.log' for more details
config.log (partially):
uname -m = x86_64
uname -r = 18.0.0
uname -s = Darwin
uname -v = Darwin Kernel Version 18.0.0: Wed Aug 22 20:13:40 PDT 2018;
root:xnu-4903.201.2~1/RELEASE_X86_64
/usr/bin/uname -p = i386
/bin/uname -X = unknown
configure:5797: checking for perl
configure:5813: found /usr/bin/perl
configure:5825: result: perl
configure:5854: === Configuring Open MPI
configure:5870: *** Startup tests
configure:5986: checking build system type
configure:6000: result: x86_64-apple-darwin18.0.0
configure:6020: checking host system type
configure:6033: result: x86_64-apple-darwin18.0.0
configure:6053: checking target system type
configure:6066: result: x86_64-apple-darwin18.0.0
configure:6196: checking for gcc
configure:6212: found /usr/local/bin/gcc
configure:6223: result: gcc
configure:6452: checking for C compiler version
configure:6461: gcc --version >&5
gcc (GCC) 8.1.0
configure:6472: $? = 0
configure:6461: gcc -v >&5
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/local/libexec/gcc/x86_64-apple-
darwin17.5.0/8.1.0/lto-wrapper
Target: x86_64-apple-darwin17.5.0
Configured with: ../gcc-8.1.0/configure --enable-languages=c++,fortran
Thread model: posix
gcc version 8.1.0 (GCC)
configure:6472: $? = 0
configure:6461: gcc -V >&5
gcc: error: unrecognized command line option '-V'
gcc: fatal error: no input files
compilation terminated.
configure:6472: $? = 1
configure:6461: gcc -qversion >&5
gcc: error: unrecognized command line option '-qversion'; did you mean
'--version'?
gcc: fatal error: no input files
compilation terminated.
configure:6472: $? = 1
configure:6492: checking whether the C compiler works
configure:6514: gcc conftest.c >&5
configure:6518: $? = 0
configure:6566: result: yes
configure:6569: checking for C compiler default output file name
configure:6571: result: a.out
configure:6577: checking for suffix of executables
configure:6584: gcc -o conftest conftest.c >&5
configure:6588: $? = 0
configure:6610: result:
configure:6632: checking whether we are cross compiling
configure:6640: gcc -o conftest conftest.c >&5
In file included from conftest.c:10:
/usr/local/lib/gcc/x86_64-apple-darwin17.5.0/8.1.0/include-
fixed/stdio.h:80:14: error: expected ';' before 'extern'
__BEGIN_DECLS
^
;
extern FILE *__stdinp;
~~~~~~
/usr/local/lib/gcc/x86_64-apple-darwin17.5.0/8.1.0/include-fixed/stdio.h:81:8: error: unknown type name 'FILE'
extern FILE *__stdinp;
^~~~
/usr/local/lib/gcc/x86_64-apple-darwin17.5.0/8.1.0/include-fixed/stdio.h:82:8: error: unknown type name 'FILE'
extern FILE *__stdoutp;
^~~~
/usr/local/lib/gcc/x86_64-apple-darwin17.5.0/8.1.0/include-fixed/stdio.h:83:8: error: unknown type name 'FILE'
extern FILE *__stderrp;
^~~~
/usr/local/lib/gcc/x86_64-apple-darwin17.5.0/8.1.0/include-fixed/stdio.h:84:1: error: unknown type name '__END_DECLS'
__END_DECLS
^~~~~~~~~~~
/usr/local/lib/gcc/x86_64-apple-darwin17.5.0/8.1.0/include-fixed/stdio.h:155:14: error: expected ';' before 'void'
__BEGIN_DECLS
^
;
void clearerr(FILE *);