error: gmp.h: No such file or directory

在编译 openswan 这个软件时，出现的错误
错误信息如下：
/usr/local/src/openswan-2.6.28/include/secrets.h:43: error: expected specifier-qualifier-list before ‘MP_INT’
/usr/local/src/openswan-2.6.28/include/secrets.h:54: error: expected specifier-qualifier-list before ‘MP_INT’
make[3]: *** [id.o] Error 1
make[3]: Leaving directory `/usr/local/src/openswan-2.6.28/OBJ.linux.i386/lib/libopenswan'
make[2]: *** [programs] Error 1
make[2]: Leaving directory `/usr/local/src/openswan-2.6.28/OBJ.linux.i386/lib'
make[1]: *** [programs] Error 1
make[1]: Leaving directory `/usr/local/src/openswan-2.6.28/OBJ.linux.i386'
make: *** [programs] Error 2

解决办法 ：

yum install -y gmp-devel