On Wed, 2025-05-07 at 00:51 +0800, lijh.8 wrote: > Correct some of my misunderstanding: > > ``` > %.d: %.c > set -e; rm -f $@; \ > $(CC) -M $(CPPFLAGS) $< > $@.$$$$; \ > sed 's,\($*\)\.o[ :]*,\1.o $@ : ,g' < $@.$$$$ > $@; \ > rm -f $@.$$$$ > ``` > > the .d file depends on `.c` source file as stated in rule ` %.d: %.c > `. > > the sed command puts the `.d` file as the target of both `.c` and > `.h` files. this makes `.d` file depend on `.h` header file too. > it will regenerate the `.d` file even when the header file is > changed. > ``` > main.o : main.c defs.h > main.o main.d : main.c defs.h > ```
That is correct. But, as said in my first reply, this is an old-fashioned and no longer recommended way to handle prerequisite tracking.
