On 18 July 2005 17:29, Dinko Tenev wrote:

On 7/18/05, Simon Marlow wrote:

...

That's the general rule, anyway. It would be an interesting exercise to specify the GHC command-line semantics, or better still, redesign it :)

I for one would find it quite helpful to see a warning line for each overriden option, if without so much of an explanation -- a "red light" to let me know something might be wrong.

I think there's a difference of philosophy here: overriding options is considered normal usage on the GHC command line. We expect to be able to do things like "make EXTRA_HC_OPTS=-Onot" to turn off optimisation, for example - we don't want this usage to generate a warning for every compilation. Every flag you specify on the command line is in effect overriding the default. We often override global defaults by putting pragmas in source files. e.g. you wouldn't want a warning for putting {-# OPTIONS -fno-warn-overlapping-patterns #-} in a source file, despite the fact that this overrides -Wall on the command line. I think there's a case for warnings in some cases (e.g. -keep-hc-files vs. -fasm might warrant a warning), but not in general. Cheers, Simon