Spec file for rpmbuild to build gdb9 on ec2

I'm using aws's ec2 instance and I need to install a newer version of GDB (I can't use yum install since there is no newer version available for amazon RHEL). My workflow requires to do this process often and I thought of having a prepared RPM to implement this task. I'm new to the process of creating RPMs and I'm not sure how to do it, I started to write the file but I ran into some issues, I'd like to share with you the file, with the issues I got: 1. I'd like to get some insight and understand if there's a better way of writing the spec file. 2. Currently I'm getting errors since I need to use the pkg's "configure" before, but this requires creating a "build" directory and only run make from within that directory. Currently I solved this by make from within a directory I created within the BUILD/gdb-9.1 dir. But I'm sure there's a more idiomatic way of doing it. 3. for this process to work, I first need to install gcc-c++ and expat-devel. I what is the best way to do it, currently my option are: 1. put it as part of the rpm installation. 2. run this command prior to the rpm installation. (yet I'd like the rpm to be something that it's the only this required, but I'm not sure if it's a good idea)

%define gdb_version       9.1
%define gdb_release       1

Name: gdb
Summary: GNU Debugger
Version: %{gdb_version}
Release: %{gdb_release}
License: GPL
URL: http://www.gnu.org/software/gdb/ 
Source0: gdb-%{gdb_version}.tar.gz
BuildRequires: readline-devel, ncurses-devel

%description
GDB, the GNU Project debugger, allows you to see what is going on inside another program while it executes.

%prep
%autosetup

%build
mkdir build
cd build
../configure \
--host=x86_64-redhat-linux-gnu \
--target=x86_64-redhat-linux-gnu \
--with-auto-load-dir=$debugdir:$datadir/auto-load:/usr/share/gdb/auto-load \
--with-auto-load-safe-path=$debugdir:$datadir/auto-load:/usr/share/gdb/auto-load \
--with-expat \
--with-gdb-datadir=/usr/share/gdb \
--with-jit-reader-dir=/usr/lib64/gdb \
--without-libunwind-ia64 \
--with-python=/usr \
--without-guile \
--with-separate-debug-dir=/usr/lib/debug \
--with-system-gdbinit=/etc/gdbinit \
--without-babeltrace
make %{?_smp_mflags}

%install
cd build
make install

%clean
rm -rf $RPM_BUILD_ROOT

%files
%defattr(-,root,root,-)