This option executes only the preprocessor phase of the compiler. By default, output from the preprocessor is sent to the standard output stream and can be redirected to a file using standard MS-DOS notation. For example:

compiler-name -E source.c > raw.c

You can also use the -o option to specify a file for the preprocessed output. By default, comments are stripped from the output. The preprocessor accepts source files with any extension (for example, .o, .s, and .txt). See also the -C option.

This option retains comments in preprocessor output when used in conjunction with -E. This option differs from the -c (lowercase) option that suppresses the link step. See Specifying output format for a description of the -c option.

This option defines symbol as a preprocessor macro. This has the same effect as the text #define symbol value at the head of the source file. You can repeat this option.

If you use a quoted string value, for example -DFOO_VALUE="FOO_VALUE", you must delimit the quotes as follows:

This option defines symbol as a preprocessor macro. This has the same effect as the text #define symbol at the head of the source file. You can repeat this option. The default value of symbol is 1.

This option executes only the preprocessor phase of the compiler, as with -E. This option produces a list of makefile dependency lines suitable for use by a make utility. By default, output is on the standard output stream. You can redirect output to a file by using standard MS-DOS notation. For example:

compiler-name -M source.c >> Makefile

If you specify the -o filename option, the dependency lines generated on standard output refer to filename.o, not to source.o. However, no object file is produced with the combination of -M -o filename.

This option undefines symbol. This has the same effect as the text #undef symbol at the head of the source file. You can repeat this option.