#7447: Stale .hi files affect compilation.
-------------------------+--------------------------------------------------
Reporter: int-e | Owner:
Type: bug | Status: new
Priority: normal | Component: Compiler
Version: 7.6.1 | Keywords:
Os: Linux | Architecture: x86_64 (amd64)
Failure: None/Unknown | Blockedby:
Blocking: | Related:
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I saw the following odd behaviour while playing with the example from
#7446. Strangely, whether the warning (unusuable UNPACK pragma) is printed
or not depends on the presence and contents of a .hi file despite of
{{{--fforce-recomp}}} and even if the source file was modified.
{{{
> rm -f Peaker.*
> ghc --version
The Glorious Glasgow Haskell Compilation System, version 7.6.1
> echo 'module Peaker(V(..)) where{ data V = V {-# UNPACK #-} !L; data L =
L V }' > Peaker.hs
> ghc -fforce-recomp -O1 Peaker.hs
[1 of 1] Compiling Peaker ( Peaker.hs, Peaker.o )
Peaker.hs:1:38: Warning:
Ignoring unusable UNPACK pragma on the first argument of `V'
In the definition of data constructor `V'
In the data declaration for `V'
> ghc -fforce-recomp -O1 Peaker.hs
[1 of 1] Compiling Peaker ( Peaker.hs, Peaker.o )
Peaker.hs:1:38: Warning:
Ignoring unusable UNPACK pragma on the first argument of `V'
In the definition of data constructor `V'
In the data declaration for `V'
> rm Peaker.hi
> ghc -fforce-recomp -O1 Peaker.hs
[1 of 1] Compiling Peaker ( Peaker.hs, Peaker.o )
Peaker.hs:1:38: Warning:
Ignoring unusable UNPACK pragma on the first argument of `V'
In the definition of data constructor `V'
In the data declaration for `V'
> echo 'module Peaker(L(..)) where{ data V = V {-# UNPACK #-} !L; data L =
L V }' > Peaker.hs
> ghc -fforce-recomp -O1 Peaker.hs
[1 of 1] Compiling Peaker ( Peaker.hs, Peaker.o )
Peaker.hs:1:38: Warning:
Ignoring unusable UNPACK pragma on the first argument of `V'
In the definition of data constructor `V'
In the data declaration for `V'
> ghc -fforce-recomp -O1 Peaker.hs
[1 of 1] Compiling Peaker ( Peaker.hs, Peaker.o )
> rm Peaker.hi
> ghc -fforce-recomp -O1 Peaker.hs
[1 of 1] Compiling Peaker ( Peaker.hs, Peaker.o )
Peaker.hs:1:38: Warning:
Ignoring unusable UNPACK pragma on the first argument of `V'
In the definition of data constructor `V'
In the data declaration for `V'
> echo 'module Peaker(V(..)) where{ data V = V {-# UNPACK #-} !L; data L =
L V }' > Peaker.hs
> ghc -fforce-recomp -O1 Peaker.hs
[1 of 1] Compiling Peaker ( Peaker.hs, Peaker.o )
> ghc -fforce-recomp -O1 Peaker.hs
[1 of 1] Compiling Peaker ( Peaker.hs, Peaker.o )
Peaker.hs:1:38: Warning:
Ignoring unusable UNPACK pragma on the first argument of `V'
In the definition of data constructor `V'
In the data declaration for `V'
> rm Peaker.hi
> ghc -fforce-recomp -O1 Peaker.hs
[1 of 1] Compiling Peaker ( Peaker.hs, Peaker.o )
Peaker.hs:1:38: Warning:
Ignoring unusable UNPACK pragma on the first argument of `V'
In the definition of data constructor `V'
In the data declaration for `V'
}}}
--
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/7447>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler
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