The software described in this documentation is either in Extended Support or Sustaining Support. See https://www.oracle.com/us/support/library/enterprise-linux-support-policies-069172.pdf for more information.
Oracle recommends that you upgrade the software described by this documentation as soon as possible.

4.1 GNU Compiler Collection

The GNU Compiler Collection (GCC) consists of utilities that you can use to compile programs, written in languages that include C, C++, Objective-C, Objective-C++, and Fortran. The GCC provides compilers such as gcc and g++, run-time libraries such as libgcc, libstdc++, and libgfortran, together with other useful tools.

The version of GCC in Oracle Linux 6 is based on the 4.4.x release series, about which you can find more information at http://gcc.gnu.org/gcc-4.4/.

The C compiler in GCC 4.4.x is largely compatible with the C99 ABI standard. For information about deviations from the C99 standard, see http://gcc.gnu.org/gcc-4.4/c99status.html.

For more information about compliance with language standards in GCC, see http://gcc.gnu.org/onlinedocs/gcc/Standards.html#Standards.