首先，gcc和g++是一起安裝的。
1. 去gcc官網(wǎng)下載源代碼 https://gcc.gnu.org
2.下載依賴包：進(jìn)入到解壓后的gcc目錄，執(zhí)行：./contrib/download_prerequisites
依賴包即會(huì)自動(dòng)下載安裝
3.編譯安裝：
mkdir gcc-build-4.8.5
cd gcc-build-4.8.5
../configure --prefix=/usr
make && make install
安裝完成后，需要設(shè)置的相關(guān)路徑如下：
export PATH="/home/zhengs/local/gcc-4.9.4/bin:$PATH"
export LD_LIBRARY_PATH="/home/zhengs/local/gcc-4.9.4/lib:/home/zhengs/local/gcc-4.9.4/lib64:$LD_LIBRARY_PATH"
export LD_RUN_PATH="/home/zhengs/local/gcc-4.9.4/lib:/home/zhengs/local/gcc-4.9.4/lib64:$LD_RUN_PATH"
export C_INCLUDE_PATH="/home/zhengs/local/gcc-4.9.4/include:$C_INCLUDE_PATH"
export CPLUS_INCLUDE_PATH="/home/zhengs/local/gcc-4.9.4/include:$CPLUS_INCLUDE_PATH"
