These rules work around make errors that are generated if you remove header files without a corresponding update to the makefile.

Examples

This example sends dependency rules to standard output, without compiling the source.

source.c includes a header file:

#include <stdio.h>

int main(void){
	puts("Hello world\n");
	return 0;
}

This first example is compiled without the -MP option, and results in a dependency rule for source.o:

armclang --target=aarch64-arm-none-eabi -mcpu=cortex-a53 -M source.c
				
source.o: source.c \
  /include/stdio.h

This second example is compiled with the -MP option, and results in a dependency rule for source.o and a dummy rule for the header file:

armclang --target=aarch64-arm-none-eabi -mcpu=cortex-a53 -M -MP source.c
				
source.o: source.c \
  /include/stdio.h

/include/stdio.h: