On 7/19/05, Simon Marlow
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.
I see. How about some verbosity level option then, to force GHC to report the overrides? Cheers, Dinko