ubuntu16.04安装GCC5.4

1. 官网下载源码
   http://ftp.gnu.org/gnu/gcc/

2. 解压文件
   tar -zxvf gcc-5.4.0.tar.bz2 //解压

3. 安装

cd gcc-5.4.0  //进入解压后的gcc文件夹
./contrib/download_prerequisites  //下载依赖项
cd ..
mkdir gcc-build-5.4.0
cd gcc-build-5.4.0
../gcc-5.4.0/configure --enable-checking=release --enable-languages=c,c++ --disable-multilib
sudo make //此命令我进入了长时间类似循环 我中断了此条命令执行 可尝试
sudo make install //

4. 检查是否安装成功
   gcc --version
   g++ --version

备注
在这个过程有可能出现一些问题，这时可以直接看download_prerequisites中的源码，一步一步的手动下载和操作
源码：

GMP=gmp-4.3.2
MPC=mpc-0.8.1

wget ftp://gcc.gnu.org/pub/gcc/infrastructure/$MPFR.tar.bz2 || exit 1
tar xjf $MPFR.tar.bz2 || exit 1
ln -sf $MPFR mpfr || exit 1

wget ftp://gcc.gnu.org/pub/gcc/infrastructure/$GMP.tar.bz2 || exit 1
tar xjf $GMP.tar.bz2  || exit 1
ln -sf $GMP gmp || exit 1

wget ftp://gcc.gnu.org/pub/gcc/infrastructure/$MPC.tar.gz || exit 1
tar xzf $MPC.tar.gz || exit 1
ln -sf $MPC mpc || exit 1

# Necessary to build GCC with the Graphite loop optimizations.
if [ "$GRAPHITE_LOOP_OPT" = "yes" ] ; then
  ISL=isl-0.14

  wget ftp://gcc.gnu.org/pub/gcc/infrastructure/$ISL.tar.bz2 || exit 1
  tar xjf $ISL.tar.bz2  || exit 1
  ln -sf $ISL isl || exit 1
fi

GMP=gmp-4.3.2
MPC=mpc-0.8.1

wget ftp://gcc.gnu.org/pub/gcc/infrastructure/$MPFR.tar.bz2 || exit 1
tar xjf $MPFR.tar.bz2 || exit 1
ln -sf $MPFR mpfr || exit 1

wget ftp://gcc.gnu.org/pub/gcc/infrastructure/$GMP.tar.bz2 || exit 1
tar xjf $GMP.tar.bz2  || exit 1
ln -sf $GMP gmp || exit 1

wget ftp://gcc.gnu.org/pub/gcc/infrastructure/$MPC.tar.gz || exit 1
tar xzf $MPC.tar.gz || exit 1
ln -sf $MPC mpc || exit 1

# Necessary to build GCC with the Graphite loop optimizations.
if [ "$GRAPHITE_LOOP_OPT" = "yes" ] ; then
  ISL=isl-0.14

  wget ftp://gcc.gnu.org/pub/gcc/infrastructure/$ISL.tar.bz2 || exit 1
  tar xjf $ISL.tar.bz2  || exit 1
  ln -sf $ISL isl || exit 1
fi

其他安装方式
https://blog.csdn.net/aBlueMouse/article/details/78145802,这是全手动安装的