[Sam: I know you don't maintain kbuild anymore, but since you have the most experience, if you could find time to comment, I'd be grateful] The select problem is that the kbuild select directive will turn a symbol on without reference to its dependencies. This, in turn, means that either selected symbols must select their dependencies, or that people using select have to be aware of the selected symbol's dependency and build those dependencies into their symbol (leading to duplication and the possibility of getting the dependencies out of sync). We use select for the scsi transport classes, so we run into this problem in SCSI quite a lot. I think the correct fix is to make a symbol that selects another symbol automatically inherit all of the selected symbol's dependencies. There seems to be a fairly easy way to do this in kbuild. Right at the moment, select is handled as additional symbol values as the last point in the symbol tree evaluation process. Instead, what I propose doing is for every select symbol, we add an extra unconditional default for the selected symbol of the selecting symbol's current value (this breaks a possible dependency cycle) and add to the dependencies of the selecting symbol, the symbol it's currently selecting. There's one wrinkle to all of this in that the current parser for default values stops when it finds the first valid (i.e. whose if clause evaluates to true) default. To make the above scheme work, I need to modify the default parser so it takes the highest tristate of all the valid defaults (and bumps m to y for bool). Does this look acceptable to people? I think it should give the desired result and has the added benefit that we can then strip the extra select overlay out of the kbuild system (making the parser slightly simpler). If this looks like a good idea to people, I think I can code up a quick patch. James -- To unsubscribe from this list: send the line "unsubscribe linux-kbuild" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
