让C/C++程序一次编译可以发布到多版本Linux之上

最近页游开放平台比较多, 每个平台要求的Linux版本各不相同, 这给开发人员部署服务器带来了很大的困难. 在本机Linux编译的程序,发布时即便将依赖的so附带到目标Linux环境,仍然会碰到依赖及版本问题,例如:

[root@localhost bin]# ldd wkcenter
./wkcenter: /usr/lib/libstdc++.so.6: version `GLIBCXX_3.4.11' not found (required by ./wkcenter)
./wkcenter: /usr/lib/libstdc++.so.6: version `GLIBCXX_3.4.14' not found (required by ./wkcenter)
./wkcenter: /usr/lib/libstdc++.so.6: version `GLIBCXX_3.4.9' not found (required by ./wkcenter)
./wkcenter: /lib/libc.so.6: version `GLIBC_2.9' not found (required by ./wkcenter)
./wkcenter: /lib/libc.so.6: version `GLIBC_2.7' not found (required by ./wkcenter)
./wkcenter: /lib/libc.so.6: version `GLIBC_2.8' not found (required by ./wkcenter)
./wkcenter: /lib/libc.so.6: version `GLIBC_2.11' not found (required by ./wkcenter)
linux-gate.so.1 => (0xffffe000)
liblog4cpp.so.4 => not found
libprotobuf.so.7 => not found
libboost_filesystem.so.1.48.0 => not found
libboost_system.so.1.48.0 => not found
libboost_thread.so.1.48.0 => not found
libboost_program_options.so.1.48.0 => not found
libunwind-x86.so.7 => not found
libluabind.so.0.9.0 => not found
libstdc++.so.6 => /usr/lib/libstdc++.so.6 (0x008ae000)
libm.so.6 => /lib/libm.so.6 (0x0044b000)
libgcc_s.so.1 => /lib/libgcc_s.so.1 (0x00476000)
libc.so.6 => /lib/libc.so.6 (0x002c1000)
libpthread.so.0 => /lib/libpthread.so.0 (0x0041d000)
librt.so.1 => /lib/librt.so.1 (0x00440000)
/lib/ld-linux.so.2 (0x002a2000)

上面红字部分表示glibc及glibcxx库依赖不正确. 本人使用的Linux编译版本为Mint 11(基于Ubuntu), 一般Ubuntu发行版的glibc配备非常高. 但是上文中的发布的Linux版本为CentOS 5.8

使用/lib/libc.so.6 查看libc版本为2.5, 远远低于开发环境的2.11

GNU C Library stable release version 2.5, by Roland McGrath et al.
Copyright (C) 2006 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.
There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A
PARTICULAR PURPOSE.
Compiled by GNU CC version 4.1.2 20080704 (Red Hat 4.1.2-51).
Compiled on a Linux 2.6.9 system on 2012-02-21.
Available extensions:
The C stubs add-on version 2.1.2.
crypt add-on version 2.1 by Michael Glad and others
GNU Libidn by Simon Josefsson
GNU libio by Per Bothner
NIS(YP)/NIS+ NSS modules 0.19 by Thorsten Kukuk
Native POSIX Threads Library by Ulrich Drepper et al
BIND-8.2.3-T5B
RT using linux kernel aio
Thread-local storage support included.
For bug reporting instructions, please see:
<http://www.gnu.org/software/libc/bugs.html>.

由于Linux操作系统的特有elf加载顺序. (可以参考此文). 虽然可以很大程度上解决Windows早期版本的dll hell问题, 但是给部署带来了很大难度

一般常见的解决方法是, 找到一个与目标Linux版本及glibc版本一致的Linux, 将代码及依赖包放在之上编译, 完成后再发布.这种方法与Linux下常见软件安装方法类似. 但是对于商用服务器部署步骤来说未免繁琐, 安全性低.

还有一种方法,使用静态链接. 将所有可执行文件文件依赖的静态库, 系统库,全部静态链接到可执行文件中,可以一次性解决这个问题

步骤:

1. 在gcc链接命令行中添加-static -static-libgcc -static-libstdc++

2. 将第三方依赖库打开静态链接开关, 将原来链接.so的库,全改为链接.a

3. gcc对链接库顺序很敏感, 链接库顺序需要按照从前至后为: 项目产生的静态库 > 第三方库静态库 > 系统静态库

4. 链接时, 若有未解决的symbol, 可以尝试在最后添加-lpthread及-lrt解决

在发布版本Linux上运行可能遇到的问题:

terminate called after throwing an instance of 'std::runtime_error'

what(): locale::facet::_S_create_c_locale name not valid

解决方法: 执行之前运行export LC_ALL="C"