On Thu, 2015-01-22 at 09:35 +0100, Paul Bolle wrote: > On Wed, 2015-01-21 at 18:23 -0800, Randy Dunlap wrote: > > On 01/21/15 15:00, Paul Bolle wrote: > > > rev_dep expressions can get rather unwieldy, especially if a symbol is > > > selected by more than a handful of other symbols. Ie, it's possible to > > > have near endless expressions like: > > > A && B && !C || D || F && (G || H) || [...] > > > > > > Chop these expressions into actually readable chunks: > > > - A && B && !C > > > - D > > > - F && (G || H) > > > - [...] > > > > > > Ie, transform the top level "||" tokens into newlines and prepend each > > > line with a minus. This makes the "Selected by:" blurb much easier to > > > read. > > > > I agree that something like this needs to be done. > > > > After reading these expressions for a few years, I can handle them OK, but > > I expect that I look at them more than most people do (with the exception of Paul). > > That's a problem with a broader scope. The specific problem this RFC > targets is neatly demonstrated by this screenshot: > Symbol: SERIAL_CORE_CONSOLE [=n] > Type : boolean > Defined at drivers/tty/serial/Kconfig:805 > Depends on: TTY [=n] && HAS_IOMEM [=y] > Selected by: SERIAL_8250_CONSOLE [=n] && TTY [=n] && HAS_IOMEM [=y] && SERIAL_8250 [=n]=y || SERIAL_AMBA_PL010_CONSOLE [=n] && [...] > > That line ends about two meters to the right of your screen. Really. > > > Here is another confusing one, at least to me: > > [This is for LBDAF on a 64-biy x86 kernel config.] > > > > Depends on: BLOCK [=y] && !64BIT [=y] > > > > I guess that the value [y,m,n] inside the square brackets is always(?) the > > symbol value (64BIT) and not the expression value (!64BIT), but that isn't > > always clear IMO. > > I think you got that right. I guess the entire screen for LBDAF looked > like this _hand edited_ example: > Symbol: LBDAF [=n] > Type : boolean > Prompt: Support for large (2TB+) block devices and files > Location: > (1) -> Enable the block layer (BLOCK [=y]) > Defined at block/Kconfig:26 > Depends on: BLOCK [=y] && !64BIT [=y] > > In this case 64BIT is set to 'y' (otherwise LBDAF would have been 'y'). This is not correct at all. If 64BIT == 'n', LBDAF can be both 'y' or 'n'. Where's that brown paper bag again? > This isn't a bug issue, of course, but I still can see how this can be > confusing. Perhaps the last line should read: > Unmet dependency on: BLOCK [=y] && !64BIT [=y] > > Would that help? Or would > Depends on: BLOCK [=y] && !64BIT [=n] > > (ie, print the value if "!64BIT") be clearer? > > > > Not-yet-signed-off-by: Paul Bolle <pebolle@xxxxxxxxxx> > > I'm glad I added that! > > > > Today I found myself wondering why a certain Kconfig was selected. > > > Currently menuconfig's help is of no use in complicated cases. Please > > > look at the help of USB or CRYPTO to see what I mean. > > > > > > This is a _hack_ to show what might be a better way to do this. It > > > parses a stringified version of the reverse dependency, and not the > > > actual reverse dependecy expression. But that was easier to cobble > > > together. > > > > > > One cool improvement would be to change to minus in front of the > > > subexpressions to Y or M for those that actually set the symbol. Anyhow, > > > other suggestions and feedback is welcome. > > > > > > scripts/kconfig/menu.c | 83 ++++++++++++++++++++++++++++++++++++++++++++++++-- > > > 1 file changed, 81 insertions(+), 2 deletions(-) Paul Bolle -- 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
