# Preprocessor Options

This section contains descriptions for compiler options that pertain to preprocessing. They are listed in alphabetical order.

Parent topic: Compiler Options

- B
  Specifies a directory that can be used to find include files, libraries, and executables.
- D
  Defines a symbol name that can be associated with an optional value.
- d-lines, Qd-lines
  Compiles debug statements.
- E
  Causes the preprocessor to send output to stdout.
- EP
  Causes the preprocessor to send output to stdout, omitting #line directives.
- fpp
  Runs the Fortran preprocessor on source files before compilation.
- fpp-name
  Lets you specify an alternate preprocessor to use with Fortran.
- gen-dep
  Tells the compiler to generate build dependencies for the current compilation.
- gen-depformat
  Specifies the form for the output generated when option gen-dep is specified.
- gen-depshow
  Determines whether certain features are excluded from dependency analysis. Currently, it only applies to intrinsic modules.
- I
  Specifies an additional directory for the include path.
- idirafter
  Adds a directory to the second include file search path.
- isystem
  Specifies a directory to add to the start of the system include path.
- module
  Specifies the directory where module files should be placed when created and where they should be searched for.
- preprocess-only
  Causes the Fortran preprocessor to send output to a file.
- u (Windows*)
  Undefines all previously defined preprocessor values.
- U
  Undefines any definition currently in effect for the specified symbol.
- undef
  Disables all predefined symbols.
- X
  Removes standard directories from the include file search path.