HP Fortran Programmer Guide (766160-001, March 2014)

1 An overview of HP Fortran
When you use the f90 command to compile a Fortran program, the command invokes a number
of components—and not just the compiler—to create the executable. By default, f90 invokes
different components to parse the source files for syntax errors, produce an intermediate code,
optimize the intermediate code, produce object code, search a set of library files for any additional
object code that may be required, and link all of the object code into an executable file that you
run without further processing.
For example, consider a program that consists of three source files: x.f90, y.f90, and z.f90.
The following command line will process the source files and, if they are syntactically correct,
produce an executable file with the default name a.out:
$ f90 x.f90 y.f90 z.f90
After compilation is complete, you can execute the program by invoking the name of the executable,
as follows:
$ a.out
However, it is likely that you’ll want to control what components act on your program and what
they do to it. For example, you may want to give the executable a name other than a.out or to
link in other libraries than the default ones. The HP Fortran compiler supports a variety of
command-line options that enable you to control the compilation process. This chapter provides
an overview of the process and of the options that enable you to control the different components
invoked by the f90 command.
NOTE: To get a summary listing of all f90 options, refer to the f90(1) manpage or use the
command, as shown here:
$ f90 +usage
For a full description of the options, see the most current version of the Parallel Programming Guide
for HP-UX Systems.
The HP Fortran compiler environment
The HP Fortran compiler environment illustrates the compilation process, showing the different
components of the HP Fortran compiler environment; active processes are unshaded and data
elements are shaded. With the exception of the performance analysis tools and the debugger
(WDB), all components are invoked by the f90 command. The C preprocessor and linker can also
be separately invoked by the cpp and ld commands; see the cpp(1)and ld(1) manpages,
respectively, for more information. The remaining sections in this chapter briefly describe the
different components and the command-line options that control them. Included in each section
are references to other parts of this manual for more detailed information.
8 An overview of HP Fortran