The GNU Fortran compiler supports the Fortran 77, 90 and 95 standards completely, parts of the Fortran 2003, 2008 and 2018 standards, and several vendor extensions. The development goal is to provide the following features:
The compiler will also attempt to diagnose cases where the user’s program contains a correct usage of the language, but instructs the computer to do something questionable. This kind of diagnostics message is called a warning message.
The GNU Fortran compiler consists of several components:
gcccommand (which also might be installed as the system’s
cccommand) that also understands and accepts Fortran source code. The
gcccommand is the driver program for all the languages in the GNU Compiler Collection (GCC); With
gcc, you can compile the source code of any language for which a front end is available in GCC.
gfortrancommand itself, which also might be installed as the system’s
gfortranis just another driver program, but specifically for the Fortran compiler only. The difference with
gfortranwill automatically link the correct libraries to your program.
gfortrancompilation phase, such as intrinsic functions and subroutines, and routines for interaction with files and the operating system.
f951). This is the GNU Fortran parser and code generator, linked to and interfaced with the GCC backend library.
f951“translates” the source code to assembler code. You would typically not use this program directly; instead, the
gfortrandriver programs will call it for you.