Imprecise error regarding SPECIALIZE and INLINE/INLINABLE pragmas

[dreixel]

Consider the following two modules:

module Test1 where

{-# INLINE f1 #-}
f1 :: (Num a) => a -> a
f1 a = a

module Test2 where

import Test1

{-# SPECIALIZE f1 :: Int -> Int #-}

Compiling with ghc --make Test2 gives

    You cannot SPECIALISE `f1'
      because its definition has no INLINE/INLINABLE pragma

But 'f1' clearly has an INLINE pragma. Adding the -O flag solves the problem. I think the error message given when compiling without optimization could be improved, perhaps mentioning that inlining pragmas are ignored when compiling without optimization.

[simonpj]

Good point. How about this?

    You cannot SPECIALISE `f1'
      because its definition has no INLINE/INLINABLE pragma
      (or you compiled its defining module without -O)

Or suggest other wording?

S

[dreixel]

That looks fine to me.

[simonpj]

Fixed by

Thu Dec  2 10:27:06 GMT 2010  simonpj@microsoft.com
  * Improve error message (Trac #4799)

    M ./compiler/typecheck/TcBinds.lhs -2 +2