This option instructs the compiler to produce a list of makefile dependency lines suitable for use by a make utility.

The compiler executes only the preprocessor step of the compilation. By default, output is on the standard output stream.

If you specify multiple source files, a single dependency file is created.

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

Use the --md option to generate dependency lines and object files for each source file.

armcc -M source.c > Makefile