On Thu, Dec 15, 2022 at 07:37:35 +0000, Iain Sandoe wrote: > * I have patches for clang that implements the P1184 interface which > would allow a ‘module mapper’ to be used to discover module name <-> > pathname pairings. > > * The demand for the command line options we are discussing here is > coming from build systems folks who want to be able to specify > everything on the command line (i.e. from my understanding they do > not want to use a module mapper, but prefer dependency scanning). > > So I think the two aspects are somewhat independent, I would expect > the same build systems folks to want to be able to specify everything > on the GCC command line too.
Note that it is particularly knowing the *output* module that is important for distributed builds so that the dispatcher can know what file(s) need to be sent and retrieved for a given command line. While GCC's module mapper has the information, it is lacking any indication of which might be output and input paths. With `-fmodule-output=`, the one output is known and anything else known to the specified `-fmodule-mapper=` (which must be understood by the dispatcher; I suspect flat files will be the preferred mechanism here rather than a socket or other fancy mechanism) can be assumed to be (potential; ideally exact) inputs. --Ben
