Chapter 2. GNU Compiler Collection (GCC)

In Red Hat Developer Toolset, the GNU C compiler is provided by the devtoolset-8-gcc package and is automatically installed with devtoolset-8-toolchain as described in Section 1.5, “Installing Red Hat Developer Toolset”.

To compile a C program on the command line, run the gcc compiler as follows:

$ scl enable devtoolset-8 '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,:

$ scl enable devtoolset-8 '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:

$ scl enable devtoolset-8 '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-8 'bash'

$ which gcc

$ gcc -v

#include <stdio.h>

int main(int argc, char *argv[]) {
  printf("Hello, World!\n");
  return 0;
}

$ scl enable devtoolset-8 'gcc -o hello hello.c'

When gcc compiles a program, it creates an executable binary file. To run this program on the command line, change to the directory with the executable file and run it:

$ ./file_name

$ ./hello
Hello, World!

In Red Hat Developer Toolset, the GNU C++ compiler is provided by the devtoolset-8-gcc-c++ package and is automatically installed with the devtoolset-8-toolchain package as described in Section 1.5, “Installing Red Hat Developer Toolset”.

To compile a C++ program on the command line, run the g++ compiler as follows:

$ scl enable devtoolset-8 'g++ -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 g++ 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:

$ scl enable devtoolset-8 'g++ -o object_file -c source_file'

This creates an object file named object_file. If the -o option is omitted, the g++ compiler creates a file named after the source file with the .o file extension. To link object files together and create a binary file:

$ scl enable devtoolset-8 'g++ -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 g++ as default:

$ scl enable devtoolset-8 'bash'

$ which g++

$ g++ -v

#include <iostream>

using namespace std;

int main(int argc, char *argv[]) {
  cout << "Hello, World!" << endl;
  return 0;
}

$ scl enable devtoolset-8 'g++ -o hello hello.cpp'

When g++ compiles a program, it creates an executable binary file. To run this program on the command line, change to the directory with the executable file and run it:

$ ./file_name

$ ./hello
Hello, World!

All compilers from Red Hat Enterprise Linux versions 5, 6, and 7 and from Red Hat Developer Toolset versions 1, 2, 3, 4, and 6 in any -std mode are compatible with any other of those compilers in C++98 mode.

A compiler in C++11 or C++14 mode is only guaranteed to be compatible with another compiler in C++11 or C++14 mode if they are from the same release series (for example from Red Hat Developer Toolset 6.x).

In Red Hat Developer Toolset, the GNU Fortran compiler is provided by the devtoolset-8-gcc-gfortran package and is automatically installed with devtoolset-8-toolchain as described in Section 1.5, “Installing Red Hat Developer Toolset”.

To compile a Fortran program on the command line, run the gfortran compiler as follows:

$ scl enable devtoolset-8 'gfortran -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:

$ scl enable devtoolset-8 'gfortran -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:

$ scl enable devtoolset-8 'gfortran -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 gfortran as default:

$ scl enable devtoolset-8 'bash'

$ which gfortran

$ gfortran -v

program hello
  print *, "Hello, World!"
end program hello

$ scl enable devtoolset-8 'gfortran -o hello hello.f'

When gfortran compiles a program, it creates an executable binary file. To run this program on the command line, change to the directory with the executable file and run it:

$ ./file_name

$ ./hello
 Hello, World!