gcc 6 outputs a shared object by default instead of an executable

[Hadrien]

Ubuntu 16.10 with gcc version 6.2.0 20161005 (Ubuntu 6.2.0-5ubuntu12)

* Install gcc: sudo apt install build-essential
* Build any program with gcc.
    Minimal example: printf "int main() { return 1; }" | gcc -x c -
* Read the output file header: readelf -h a.out

Expected result: the ELF header Type shows: EXEC
Actual result: the ELF header Type shows: DYN

The side effect is that we cannot run any program built with gcc 6 from Nautilus. Nautilus opens an error message saying it does not know how to handle a shared library.

Most programs in /bin and /usr/bin cannot be started from Nautilus by double-clicking.

Everything was fine with the gcc release in Ubuntu 16.04

ProblemType: Bug
DistroRelease: Ubuntu 16.10
Package: gcc 4:6.1.1-1ubuntu2
ProcVersionSignature: Ubuntu 4.8.0-22.24-generic 4.8.0
Uname: Linux 4.8.0-22-generic x86_64
ApportVersion: 2.20.3-0ubuntu8
Architecture: amd64
CurrentDesktop: Unity
Date: Fri Oct 21 21:11:46 2016
EcryptfsInUse: Yes
InstallationDate: Installed on 2016-10-14 (6 days ago)
InstallationMedia: Ubuntu 16.10 "Yakkety Yak" - Release amd64 (20161012.2)
SourcePackage: gcc-defaults
UpgradeStatus: No upgrade log present (probably fresh install)

[Hadrien (psydk)]

I tried with a two steps generation: first a call to "gcc" to generate a .o file, then a call to "ld" to generate an executable.

I attached a minimal example program that does not need the libc or standard crt.o. I used a slightly modified version of that program :

https://gist.github.com/lunixbochs/462ee21c3353c56b910f

in order to get the smallest "ld" command line possible. This is it:

ld -dynamic-linker /lib64/ld-linux-x86-64.so.2 -pie -o exe plop.o

I found that when the "-pie" option is removed, the ELF header Type field changes from DYN to EXEC.

[Hadrien (psydk)]

It looks like it is actually expected for an ELF executable to have the type DYN when it is built with -pie.

[adfaure (adrien-faure2)]

Hello, this bug affects me. The project I am working on requires to work with Executable ELF.
I try to rebuild gcc from apt-source, Unfortunately the command fails...

Do you know a solution (a part from re-install ubuntu 16.04 for example) ?

thank you.
Adrien.