Warning for literal overflow

Using ghc 7.6.3, the following compiles without warnings on -Wall:

import Data.Word

test :: Word8
test = 300

main = print test

I expected this to issue a warning like: "Warning: literal overflow on line 4". I know GCC for example does this and it would be nice if GHC did this too.

Trac metadata

Trac field	Value
Version	7.6.3
Type	FeatureRequest
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Compiler
Test case
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changed weight to 5

added Tfeature request Trac import labels

I'm not sure theres a good way to do this...

GHC currently lacks any model or "theory of integers", so can't reason about over/underflows presently, let alone issue a warning on them.

This is related to the "better numerics" tickets listed here http://hackage.haskell.org/trac/ghc/wiki/Status/SLPJ-Tickets

mentioned in commit 4e7eb3a0

closed

changed milestone to %7.8.1

Thanks for the suggestion; now done.

Trac metadata

Trac field	Value
Resolution	Unresolved → ResolvedFixed

mentioned in issue #8542 (closed)

mentioned in issue #9854

added Pnormal label

mentioned in issue #24216