CentOS 7.4.1708安装GCC4.9.4

meimei10251314

　　今天安装MariaDB10.2.9 ，cmake的时候出现以下错误：

CMake Error at storage/tokudb/ft-index/cmake_modules/TokuSetupCompiler.cmake:182 (message):
/usr/bin/c++ doesn't support -std=c++11 or -std=c++0x, you need one that does.
　　吓得我赶紧上网一查，我尼玛。。貌似gcc的版本太低了，二话不说，升级。
　　1. 下载GCC4.9.4源码

wget http://ftp.tsukuba.wide.ad.jp/software/gcc/releases/gcc-4.9.4/gcc-4.9.4.tar.gz
　　2. 下载加压

tar zxvf gcc-4.9.4.tar.gz
　　3. 进入gcc目录下载其依赖包

cd gcc-4.9.4
./contrib/download_prerequisites
　　4. 建立临时编译目录并进入

mkdir build-gcc
cd build-gcc/
　　5. 在GCC的临时编译目录里编译、安装

../gcc-4.9.4/configure --enable-checking=release --enable-languages=c,c++ --disable-multilib
make -j 8
make install
　　最后安装完，编译程序会抛出一段话，如下：

Libraries have been installed in:
/usr/local/lib/../lib64
If you ever happen to want to link against installed libraries
in a given directory, LIBDIR, you must either use libtool, and
specify the full pathname of the library, or use the `-LLIBDIR'
flag during linking and do at least one of the following:
- add LIBDIR to the `LD_LIBRARY_PATH' environment variable
during execution
- add LIBDIR to the `LD_RUN_PATH' environment variable
during linking
- use the `-Wl,-rpath -Wl,LIBDIR' linker flag
- have your system administrator add LIBDIR to `/etc/ld.so.conf'
See any operating system documentation about shared libraries for
more information, such as the ld(1) and ld.so(8) manual pages.
　　我这里是执行了make install 之后就直接reboot系统，再开机就是4.9.4版本了。