Compile program for 32bit on 64bit Linux OS causes fatal error

Question

Using

gcc -m32 myprog.c

should compile in 32 bit version the file myprog.c.

Unfortunately I get this error:

In file included from /usr/include/stdio.h:27:0,
                 from myprog.c:1:
/usr/include/features.h:374:25: fatal error: sys/cdefs.h: No such file or directory
#include <sys/cdefs.h>

How could I fix this?

If I don't use -m32 it works but uses 64 bit instructions.

Answer 1

To fix the issue we first need to know which package will provide the file sys/cdefs.h

In CentOs/RHEL based system you can find it by running below command

yum provides '*sys/cdefs.h'

Similarly, in Debian/Ubuntu systems you can find it by running

apt-file search 'sys/cdefs.h'

Note: If apt-file package is not already present on the system install it with command

apt-get install apt-file

Both above commands will scan the respective package management systems database i.e RPM/Apt and tells the name of the package which supplies the file ending with "sys/cdefs.h".

Install the appropriate package from the packages listed by the commands.
Like

On CentOs/RHEL:

yum install glibc-headers 

On Debian/Ubuntu

apt-get install libc6-dev

This approach is not only useful for this particular issue but any similar issue which is reporting some required file being provided by some package being not present.

Answer 2

I encountered to this same problem. when I was trying to build 32 bit so file while i'm in 64 bit ubuntu version.

you can build by switching your lib version into 64 bit in netbeans (-> project properties -> C compiler -> additional options) set to

-shared -m64

Answer 3

You need gcc multilib support. Install the package gcc-multilib. E.g.:

sudo apt-get install gcc-multilib

Answer 4

To compile 32 bit binaries on 64 bit Linux version, you have to Install libx32gcc development package and 32 bit GNU C Library

try this

sudo apt-get install libx32gcc-4.8-dev

and

sudo apt-get install libc6-dev-i386