系統:CentOS-6.5-x86_64-minimal
為了使用c++11特性，升級gcc.
wget http://ftp.tsukuba.wide.ad.jp/software/gcc/releases/gcc-4.9.2/gcc-4.9.2.tar.bz2 tar -xjvf gcc-4.9.2.tar.bz2 cd gcc-4.9.2.tar.bz2 ./configure
wget下載慢，服務器也是日本的，可以用QQ旋風或迅雷下載，再psftp上傳，
出現錯誤:
configure: error: Building GCC requires GMP 4.2+, MPFR 2.4.0+ and MPC 0.8.0+. Try the --with-gmp, --with-mpfr and/or --with-mpc options to specify their locations. Source code for these libraries can be found at their respective hosting sites as well as at ftp://gcc.gnu.org/pub/gcc/infrastructure/.
安裝gmp、mpfr、mpc
下載地址：
http://ftp.tsukuba.wide.ad.jp/software/gcc/infrastructure/gmp-4.3.2.tar.bz2 http://ftp.tsukuba.wide.ad.jp/software/gcc/infrastructure/mpfr-2.4.2.tar.bz2 http://ftp.tsukuba.wide.ad.jp/software/gcc/infrastructure/mpc-0.8.1.tar.gz
解壓后逐個安裝，
./configure
make
make install
再次錯誤，
The following languages will be built: c,c++,fortran,java,lto,objc *** This configuration is not supported in the following subdirectories: gnattools target-libada target-libgo target-libbacktrace (Any other directories should still work fine.) checking for default BUILD_CONFIG... bootstrap-debug checking for --enable-vtable-verify... no /usr/bin/ld: crt1.o: No such file: No such file or directory collect2: ld returned 1 exit status configure: error: I suspect your system does not have 32-bit developement libraries (libc and headers).
If you have them, rerun configure with --enable-multilib.
If you do not have them, and want to build a 64-bit-only compiler, rerun configure with --disable-multilib.
系統沒有32位開發支持庫,可以運行yum install glibc-devel.i686安裝，不過我這里不需要編譯32位程序，直接
./configure --disable-multilib
這回配置完成，
make
出現錯誤，
checking whether build environment is sane... configure: error: newly created file is older than distributed files! Check your system clock make[2]: *** [configure-stage1-zlib] Error 1 make[2]: Leaving directory `/root/gcc-4.9.2' make[1]: *** [stage1-bubble] Error 2 make[1]: Leaving directory `/root/gcc-4.9.2' make: *** [all] Error 2
更新時間，
ntpdate cn.pool.ntp.org
繼續
make
約半小時后，出現錯誤，
checking for suffix of object files... configure: error: in `/root/gcc-4.9.2/x86_64-unknown-linux-gnu/libgcc': configure: error: cannot compute suffix of object files: cannot compile See `config.log' for more details. make[2]: *** [configure-stage1-target-libgcc] Error 1 make[2]: Leaving directory `/root/gcc-4.9.2' make[1]: *** [stage1-bubble] Error 2 make[1]: Leaving directory `/root/gcc-4.9.2' make: *** [all] Error 2
查看config.log，發現在配置libgcc時出錯了，yum list libgcc，發現已安裝libgcc.x86_64，難道要裝i686的？go~
yum install libgcc.i686
繼續
make
約四小時這樣子就編譯完成了,
make install
幾分鍾就安裝完成。
看效果
gcc -v Using built-in specs. COLLECT_GCC=gcc COLLECT_LTO_WRAPPER=/usr/local/libexec/gcc/x86_64-unknown-linux-gnu/4.9.2/lto-wrapper Target: x86_64-unknown-linux-gnu Configured with: ./configure --disable-multilib Thread model: posix gcc version 4.9.2 (GCC)