Red Hat Developer Toolset 1.x User Guide - Linux

20 Chapter 2. GNU Compiler Collection (GCC)
Chapter 2. GNU Compiler Collection (GCC)
The GNU Compiler Collection, commonly abbreviated GCC, is a portable compiler suite with support
for a wide selection of programming languages.
Red Hat Developer Toolset is distributed with GCC 4 .7.2. This version is more recent than the version
included in Red Hat Enterprise Linux and provides numerous bug fixes and enhancements, including
optimization for various new Intel and AMD processors, support for OpenMP 3.1 and link-time
optimization. This version also includes experimental support for the C++11 standard, C++11 atomic
types, and Transactional Memory. For a detailed list of changes, refer to Section B.1, “Changes in GCC
4.7.2”.
2.1. GNU C Compiler
2.1.1. Installing the C Compiler
In Red Hat Developer Toolset, the GNU C compiler is provided by the devtoolset-1.1-gcc package, and is
automatically installed with devtoolset-1.1 as described in Section 1.5, “Installing Red Hat Developer
Toolset”.
2.1.2. Using the C Compiler
To compile a C program on the command line, run the gcc compiler as follows:
scl enable devtoolset-1.1 'gcc -o output_file source_file...'
This creates a binary file named output_file in the current working directory. If the -o option is
omitted, the compiler creates a file named a.out by default.
When you are working on a project that consists of several source files, it is common to compile an
object file for each of the source files first and then link these object files together. This way, when you
change a single source file, you can recompile only this file without having to compile the entire project.
To compile an object file on the command line, run the following command:
scl enable devtoolset-1.1 'gcc -o object_file -c source_file'
This creates an object file named object_file. If the -o option is omitted, the compiler creates a file
named after the source file with the .o file extension. To link object files together and create a binary file,
run:
scl enable devtoolset-1.1 'gcc -o output_file object_file...'
Note that you can execute any command using the scl utility, causing it to be run with the Red Hat
Developer Toolset binaries used in preference to the Red Hat Enterprise Linux system equivalent. This
allows you to run a shell session with Red Hat Developer Toolset gcc as default:
scl enable devtoolset-1.1 'bash'