CentOS x86_64上编译32位demo程序

先写个hello world的简单程序

gcc -m32 a.c

先确保a.c能够编译链接成功，再去编译你的32位程序。

[root@localhost ~]# gcc -m32 hello.c 
In file included from /usr/include/features.h:399:0,
                 from /usr/include/stdio.h:27,
                 from hello.c:1:
/usr/include/gnu/stubs.h:7:27: fatal error: gnu/stubs-32.h: No such file or directory
 # include <gnu/stubs-32.h>
                           ^
compilation terminated.
[root@localhost ~]#

编译失败，缺少32位头文件。

使用yum安装i686的库

[root@localhost centos-release]# yum list glibc
Loaded plugins: fastestmirror, langpacks
Loading mirror speeds from cached hostfile
Installed Packages
glibc.i686                                      2.17-55.el7                                    @base    
glibc.x86_64                                    2.17-55.el7                                    @anaconda

[root@localhost centos-release]# yum install glibc.i686

yum安装时有个小插曲，提示GPG keys配置有问题：

The GPG keys listed for the "CentOS-7 - Base - 163.com" repository are already installed but they are not correct for this package.
Check that the correct key URLs are configured for this repository.

解决方法：

手动从163网站导入CentOS-7的key，我的版本是CentOS 7。

rpm -import http://mirrors.163.com/centos/RPM-GPG-KEY-CentOS-7

安装glibc开发库：

[root@localhost ~]# yum list *glibc*
Loaded plugins: fastestmirror, langpacks
Loading mirror speeds from cached hostfile
Installed Packages
compat-glibc.x86_64                                1:2.12-4.el7.centos                         @anaconda
compat-glibc-headers.x86_64                        1:2.12-4.el7.centos                         @anaconda
glibc.i686                                         2.17-55.el7                                 @base    
glibc.x86_64                                       2.17-55.el7                                 @anaconda
glibc-common.x86_64                                2.17-55.el7                                 @anaconda
glibc-devel.x86_64                                 2.17-55.el7                                 @anaconda
glibc-headers.x86_64                               2.17-55.el7                                 @anaconda
Available Packages
glibc-devel.i686                                   2.17-55.el7                                 base     
glibc-static.i686                                  2.17-55.el7                                 base     
glibc-static.x86_64                                2.17-55.el7                                 base     
glibc-utils.x86_64                                 2.17-55.el7                                 base     
[root@localhost ~]# yum install glibc-devel.i686

再次编译，发现编译成功，但是链接失败。

[root@localhost ~]# gcc -m32 hello.c 
/usr/bin/ld: skipping incompatible /usr/lib/gcc/x86_64-redhat-linux/4.8.2/libgcc_s.so when searching for -lgcc_s
/usr/bin/ld: cannot find -lgcc_s
collect2: error: ld returned 1 exit status
[root@localhost ~]#

缺少动态库libgcc

[root@localhost ~]# yum list libgcc
Loaded plugins: fastestmirror, langpacks
Loading mirror speeds from cached hostfile
Installed Packages
libgcc.x86_64                                   4.8.2-16.el7                                   @anaconda
Available Packages
libgcc.i686                                     4.8.2-16.el7                                   base     
[root@localhost ~]# yum install libgcc.i686

libgcc安装成功后，再次编译

[root@localhost ~]# gcc -m32 hello.c

[root@localhost ~]# ./a.out
hello world

发现编程链接全部成功，OK，大功告成。