On Mon, 27 Jan 2014 12:49:40 -0800, Eric Fowler said:
I want to know more about how that file interacts with the build system. In particular, in situations like a build seeing a syntax error in foo.c, I want to trace from foo.c all the way up to every entry in dot-config that imports or depends on foo.c.
You have that backwards. You want every entry in .config that foo.c depends on. Hint 1: For a given drivers/bar/foo.c, you want to take a quick peek at drivers/bar/.foo.o.cmd - that's what kbuild uses so 'make' can figure out what needs rebuilding Hint 2: Fiven the list of .c and .h files files that a given .o depends on, it becomes trivial to generate a list of CONFIG_* variables that are potentially referenced. Hint 3: It's almost always a problem with a missing declaration of 'frobozz' or whatever - at which point 'find include -type f | xargs grep frobozz' and then looking at what #ifdef's wrap the definition of frobozz is usually more productive....