编译安装GCC12

Jan 1, 2022 · Jun

因为想用C++20标准的原因，所以要求使用GCC12。可是Ubuntu20默认的编译器是GCC9，于是只好自己编译安装一个 GCC trunk。

没想到听起来很简单的事情，真正做起来竟然有那么多的坑，所以还是稍微写点文字记录一下。

下载源码

1

git clone https://github.com/gcc-mirror/gcc.git

配置依赖

1

sudo apt install flex

1
2


cd gcc
./contrib/download_prerequisites

编译

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13


mkdir build && cd build

../configure -v \
  --build=x86_64-linux-gnu \
  --host=x86_64-linux-gnu  \
  --target=x86_64-linux-gnu \
  --enable-checking=no      \
  --enable-languages=c,c++  \
  --disable-multilib        \
  --prefix=/usr/local       \
  --disable-bootstrap

make -j$(nproc)

耐心等待编译完成，具体时间要看机器的性能。

安装

1

sudo make install

踩的坑

安装好gcc后不知道为什么在编译LLVM的时候会报错：

1

/lib/x86_64-linux-gnu/libstdc++.so.6: version `GLIBCXX_3.4.30' not found

使用strings /lib/x86_64-linux-gnu/libstdc++.so.6 | grep GLIBCXX可以发现确实没有GLIBCXX_3.4.30。使用ls -al /lib/x86_64-linux-gnu/libstdc++.so.6可以发现这是一个软链接：

1

lrwxrwxrwx 1 root root 36 1月   1 13:44 libstdc++.so.6 -> libstdc++.so.6.29

很显然这还是旧版本的libstdc++，观察安装后gcc给我们的提示：

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16


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.

更新LD_LIBRARY_PATH即可：

将下面命令加入到用户shell配置文件中：

1

export LD_LIBRARY_PATH=/usr/local/lib64