Linux安装gcc-6.1.0

获取gcc源码包

gcc各版本地址：https://ftp.gnu.org/gnu/gcc
目前最新的是6.1.0版：https://ftp.gnu.org/gnu/gcc/gcc-6.1.0/gcc-6.1.0.tar.bz2

# wget https://ftp.gnu.org/gnu/gcc/gcc-6.1.0/gcc-6.1.0.tar.bz2
# tar -jxvf gcc-6.1.0.tar.bz2

下载依赖项

执行download_prerequisites将会自动下载这些软件并解压到当前目录，生成gcc编译的make文件。自动安装gcc需要下载诸如gmp、mpfr、mpc等依赖文件：

# cd gcc-6.1.0
# ./contrib/download_prerequisites

如果你的Linux无法直接联网，那么你只能打开文件download_prerequisites，获取到这些文件的下载链接，然后通过其他上网设备下载这些软件。最后把这些软件直接解压到gcc源程序目录(/路径/6.1.0)下即可。

编译安装

# mkdir gcc-build
# cd gcc-build
# ../configure -enable-checking=release -enable-languages=c,c++ -disable-multilib
# make
# make install

注意make的-j选项可以指定同时运行的作业数量，即CPU核数，如果有4核则可以加上-j4

出错解决

1.make过程中可能会出现以下错误信息：

 build/genattrtab ../.././gcc/config/i386/i386.md insn-conditions.md \
  -Atmp-attrtab.c -Dtmp-dfatab.c -Ltmp-latencytab.c
make[3]: *** [s-attrtab] Killed
make[3]: Leaving directory `/usr/src/gcc-4.9.2/host-x86_64-unknown-linux-gnu/gcc'
make[2]: *** [all-stage1-gcc] Error 2
make[2]: Leaving directory `/usr/src/gcc-4.9.2'
make[1]: *** [stage1-bubble] Error 2
make[1]: Leaving directory `/usr/src/gcc-4.9.2'
make: *** [all] Error 2

可以通过添加swap分区的方法解决：
http://blog.csdn.net/qq_20480611/article/details/52144399

2.动态库libstdc++.so.6版本不匹配
可以正常编译程序，但是运行时出现以下问题：
/usr/lib/libstdc++.so.6: version `GLIBCXX_3.4.15’ not found
添加LD_LIBRARY_PATH环境变量即可解决：

# vim ~/.bash_profile
export LD_LIBRARY_PATH=/usr/local/lib:/usr/lib:/usr/local/lib64:/usr/lib64
# source ~/.bash_profile

GCC新特征

GCC 6.1 发布了，该版本较之前GCC5 新怎了大量的功能特性，默认采用C++14为新的标准，替代了之前的C++98。OpenMP 4.5规范将在本版本中被支持。此外，GCC 6.1 增强了对 C++17 的试验性支持；大大改进了诊断特性，包括位置，位置范围，拼写错误标识符建议，选项名字等等改进；新增了修复提示和一些警告提示。改进记录如下：

• UndefinedBehaviorSanitizer gained a new sanitization option, -fsanitize=bounds-strict, which enables strict checking of array bounds. In particular, it enables -fsanitize=bounds as well as instrumentation of flexible array member-like arrays.

• Type-based alias analysis now disambiguates accesses to different pointers. This improves precision of the alias oracle by about 20-30% on higher-level C++ programs. Programs doing invalid type punning of pointer types may now need -fno-strict-aliasing to work correctly.

• Alias analysis now correctly supports weakref and alias attributes. This makes it possible to access both a variable and its alias in one translation unit which is common with link-time optimization.

• Value range propagation now assumes that the this pointer of C++ member functions is non-null. This eliminates common null pointer checks but also breaks some non-conforming code-bases (such as Qt-5, Chromium, KDevelop). As a temporary work-around-fno-delete-null-pointer-checks can be used. Wrong code can be identified by using-fsanitize=undefined.

完整发布说明，可以在这里查看。

参考文章

CentOS下安装gcc-4.9.2
centos6.5安装gcc6.1等c++环境
https://gcc.gnu.org/onlinedocs/libstdc++/faq.html#faq.how_to_set_paths

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