Preprocessor Options

The preprocessor options let you specify how the compiler preprocesses files as an optional first phase of the compilation and where it looks for source directories.

See Also
Preprocessing Phase

Predefined Preprocessor Symbols

Descriptions of Preprocessor Options

-assume [no]source_include

Default: -assume source_include

Specifies the directory searched for module files specified by a USE statement or source files specified by an INCLUDE statement.

Possible values are:

Note that you can use this option whether or not you use the  -fpp option.


Default: Off

Specifies one or more definitions for use with conditional compilation directives or the Fortran preprocessor, fpp. If you have more than one, use separate -D options.

The value can be a character or integer value. If value not specified, 1 is assumed to be the value for name.

For an example, see Defining Preprocessor Symbols.


Do not use D for name, because it will conflict with the -DD option (alternate syntax for -d_lines). However, you can use the -Dname=n syntax, such as -DD=1.


Default:  -nofpp

Alternate syntax: -[no]cpp; also fpp 0 is equivalent to -nofpp; also fpp n (where n is any number greater than 0) is equivalent to -fpp

Invokes the FPP Preprocessor (fpp) prior to compilation, enabling preprocessor directives.

-cpp is the same as -fpp (runs fpp, not the C preprocessor).


Default: Include path

Specifies one or more directories to add to the include path, which is searched for module files (USE statement) and include files (INCLUDE statement). Use a semicolon delimiter for more than one directory.

To request that the compiler search first in the directory where the source file resides instead of the current directory, specify -assume source_include.

For all USE statements and for those INCLUDE statements whose file name does not begin with a device or directory name, the directories searched are as follows, in this order:

  1. The directory containing the first source file (if -assume source_include was specified, which is the default).

  2. The current default directory where the compilation is taking place.

  3. If specified, the directory or directories listed in the -Idir option. The order of searching multiple directories occurs within the specified list from left to right

  4. The directories indicated in the compile-time environment variable FPATH.

See also -noinclude.


Default: Off

Alternate syntax: -P and -F

Runs the Fortran preprocessor (fpp) and puts the result for each source file in a corresponding .i or .i90 file. The .i or .i90 file does not have line numbers (#) in it. The source file is not compiled.

You need to specify -fpp with this option.

-U name

Default: Off.

Undefines any definition currently in effect for the symbol specified by name.


Default: Off

Passes options (specified by option1, option2, and so forth) to the preprocessor.

This option is the same as -fpp, except that -fpp also invokes fpp.