Generate warning-free Haskell code

andreasabel commented 3 years ago

Recover the property of BNFC 2.7.1 to generate warning-free Haskell code https://github.com/BNFC/bnfc/blame/0ad87322fce4cfe309512fa9fd56a63a06ff9c19/source/CHANGELOG.md#L117

[x] Abs.hs: unused imports: fixed in a3510534f873c9f1748c552a4e24ef7174d203c7
[x] Abs.hs: no type signatures for defined constructors with --functor: fixed in 195cc1bc2cccf9847e389e129743db0453e6958c
[x] Layout.hs: unused-matches: fixed in 4343b31282cf24ed782f13caaf6c4f26d2206760
[x] Print.hs: locals (like id) shadow globals (see also #337): fixed in 3b2029e053a9a33ddc3e982b0dd4a4d3d2b5c5d3
[x] Skel.hs: has unused-matches, need to turn warning off: fixed in 89e591487064652a6415589395593da9ffeab190
[x] Test.hs: misc: fixed in 5208f67ce07c19af5e6fffd433e6c088e09829cd
[x] XML.hs
[x] XMLT.hs
[ ] Haskell/GADT

andreasabel commented 3 years ago

89e591487064652a6415589395593da9ffeab190 breaks compilation with GHC 7.10:

$ cabal build -w ghc-7.10.3
...
HierMod/Skel.hs:3:16:
    unknown flag in  {-# OPTIONS_GHC #-} pragma: -Wno-unused-matches

andreasabel commented 3 years ago

Seems like the default test cases for XML and Haskell/GADT are now warning-free (testsuite passes).

andreasabel commented 3 years ago

There is a warning in Haskell/GADT with ghc 9.0:

ghc -XNoImplicitPrelude -Wall -Werror TestTest
[1 of 8] Compiling ComposOp         ( ComposOp.hs, ComposOp.o )
[2 of 8] Compiling AbsTest          ( AbsTest.hs, AbsTest.o )

AbsTest.hs:23:21: error: [-Wstar-is-type, -Werror=star-is-type]
    Using ‘*’ (or its Unicode variant) to mean ‘Data.Kind.Type’
    relies on the StarIsType extension, which will become
    deprecated in the future.
    Suggested fix: use ‘Type’ from ‘Data.Kind’ instead.
   |
23 | data Tree :: Tag -> * where

Dropping GHC 7.10, we could assume base-4.9 and use Data.Kind.Type instead of *. The StarIsType extension exists only since GHC 8.6 and is, while on by default, deprecated, to move away from * for Type.

andreasabel commented 3 years ago

Haskell-GADT moved to issue #346.

BNFC / bnfc

Generate warning-free Haskell code #331