[Git][ghc/ghc][wip/fix-hadrian-ghci] 3 commits: Derive Ord instance for Extension
Ben Gamari
gitlab at gitlab.haskell.org
Mon Apr 20 17:05:44 UTC 2020
Ben Gamari pushed to branch wip/fix-hadrian-ghci at Glasgow Haskell Compiler / GHC
Commits:
36882493 by Shayne Fletcher at 2020-04-20T04:36:43-04:00
Derive Ord instance for Extension
Metric Increase:
T12150
T12234
- - - - -
b43365ad by Simon Peyton Jones at 2020-04-20T04:37:20-04:00
Fix a buglet in redundant-constraint warnings
Ticket #18036 pointed out that we were reporting a redundant
constraint when it really really wasn't.
Turned out to be a buglet in the SkolemInfo for the
relevant implication constraint. Easily fixed!
- - - - -
f6cb3236 by Ben Gamari at 2020-04-20T13:05:37-04:00
hadrian/ghci: Allow arguments to be passed to GHCi
Previously the arguments passed to hadrian/ghci were passed both to
`hadrian` and GHCi. This is rather odd given that there are essentially
not arguments in the intersection of the two. Let's just pass them to
GHCi; this allows `hadrian/ghci -Werror`.
- - - - -
9 changed files:
- compiler/GHC/Tc/TyCl/Instance.hs
- hadrian/ghci
- hadrian/ghci-cabal
- hadrian/ghci-stack
- libraries/ghc-boot-th/GHC/LanguageExtensions/Type.hs
- + testsuite/tests/typecheck/should_compile/T18036.hs
- + testsuite/tests/typecheck/should_compile/T18036a.hs
- + testsuite/tests/typecheck/should_compile/T18036a.stderr
- testsuite/tests/typecheck/should_compile/all.T
Changes:
=====================================
compiler/GHC/Tc/TyCl/Instance.hs
=====================================
@@ -1719,19 +1719,26 @@ tcMethodBodyHelp hs_sig_fn sel_id local_meth_id meth_bind
| Just hs_sig_ty <- hs_sig_fn sel_name
-- There is a signature in the instance
-- See Note [Instance method signatures]
- = do { let ctxt = FunSigCtxt sel_name True
- ; (sig_ty, hs_wrap)
+ = do { (sig_ty, hs_wrap)
<- setSrcSpan (getLoc (hsSigType hs_sig_ty)) $
do { inst_sigs <- xoptM LangExt.InstanceSigs
; checkTc inst_sigs (misplacedInstSig sel_name hs_sig_ty)
; sig_ty <- tcHsSigType (FunSigCtxt sel_name False) hs_sig_ty
; let local_meth_ty = idType local_meth_id
+ ctxt = FunSigCtxt sel_name False
+ -- False <=> do not report redundant constraints when
+ -- checking instance-sig <= class-meth-sig
+ -- The instance-sig is the focus here; the class-meth-sig
+ -- is fixed (#18036)
; hs_wrap <- addErrCtxtM (methSigCtxt sel_name sig_ty local_meth_ty) $
tcSubType_NC ctxt sig_ty local_meth_ty
; return (sig_ty, hs_wrap) }
; inner_meth_name <- newName (nameOccName sel_name)
- ; let inner_meth_id = mkLocalId inner_meth_name sig_ty
+ ; let ctxt = FunSigCtxt sel_name True
+ -- True <=> check for redundant constraints in the
+ -- user-specified instance signature
+ inner_meth_id = mkLocalId inner_meth_name sig_ty
inner_meth_sig = CompleteSig { sig_bndr = inner_meth_id
, sig_ctxt = ctxt
, sig_loc = getLoc (hsSigType hs_sig_ty) }
=====================================
hadrian/ghci
=====================================
@@ -1,4 +1,4 @@
#!/usr/bin/env bash
# By default on Linux/MacOS we build Hadrian using Cabal
-(. "hadrian/ghci-cabal" "$@")
+(. "hadrian/ghci-cabal" $@)
=====================================
hadrian/ghci-cabal
=====================================
@@ -3,5 +3,5 @@
set -e
# Replace newlines with spaces, as these otherwise break the ghci invocation on windows.
-GHC_FLAGS="$GHC_FLAGS $(TERM=dumb CABFLAGS=-v0 "hadrian/build-cabal" tool-args -q --build-root=.hadrian_ghci --flavour=ghc-in-ghci "$@" | tr '\n\r' ' ')"
-ghci $GHC_FLAGS "$@" -fno-code -fwrite-interface -hidir=.hadrian_ghci/interface -O0 ghc/Main.hs +RTS -A128m
+GHC_FLAGS="$GHC_FLAGS $(TERM=dumb CABFLAGS=-v0 "hadrian/build-cabal" tool-args -q --build-root=.hadrian_ghci --flavour=ghc-in-ghci $HADRIAN_ARGS | tr '\n\r' ' ')"
+ghci $GHC_FLAGS $@ -fno-code -fwrite-interface -hidir=.hadrian_ghci/interface -O0 ghc/Main.hs +RTS -A128m
=====================================
hadrian/ghci-stack
=====================================
@@ -3,5 +3,5 @@
set -e
# Replace newlines with spaces, as these otherwise break the ghci invocation on windows.
-GHC_FLAGS="$GHC_FLAGS $(TERM=dumb CABFLAGS=-v0 "hadrian/build-stack" tool-args -q --build-root=.hadrian_ghci --flavour=ghc-in-ghci "$@" | tr '\n\r' ' ')"
+GHC_FLAGS="$GHC_FLAGS $(TERM=dumb CABFLAGS=-v0 "hadrian/build-stack" tool-args -q --build-root=.hadrian_ghci --flavour=ghc-in-ghci $HADRIAN_ARGS | tr '\n\r' ' ')"
stack exec -- ghci $GHC_FLAGS "$@" -fno-code -fwrite-interface -hidir=.hadrian_ghci/interface -O0 ghc/Main.hs +RTS -A128m
=====================================
libraries/ghc-boot-th/GHC/LanguageExtensions/Type.hs
=====================================
@@ -145,3 +145,7 @@ data Extension
| CUSKs
| StandaloneKindSignatures
deriving (Eq, Enum, Show, Generic, Bounded)
+-- 'Ord' and 'Bounded' are provided for GHC API users (see discussions
+-- in https://gitlab.haskell.org/ghc/ghc/merge_requests/2707 and
+-- https://gitlab.haskell.org/ghc/ghc/merge_requests/826).
+instance Ord Extension where compare a b = compare (fromEnum a) (fromEnum b)
=====================================
testsuite/tests/typecheck/should_compile/T18036.hs
=====================================
@@ -0,0 +1,13 @@
+{-# LANGUAGE InstanceSigs #-}
+{-# OPTIONS_GHC -Wredundant-constraints #-}
+
+module T18036 where
+
+class Fold f where
+ fold :: Monoid m => f m -> m
+
+newtype Identity a = Identity a
+
+instance Fold Identity where
+ fold :: Identity a -> a
+ fold (Identity a) = a
=====================================
testsuite/tests/typecheck/should_compile/T18036a.hs
=====================================
@@ -0,0 +1,15 @@
+{-# LANGUAGE InstanceSigs #-}
+{-# OPTIONS_GHC -Wredundant-constraints #-}
+
+module T18036 where
+
+class Fold f where
+ fold :: Monoid m => f m -> m
+
+newtype Identity a = Identity a
+
+-- Here we /should/ warn about redundant constraints in the
+-- instance signature, since we can remove them
+instance Fold Identity where
+ fold :: Monoid a => Identity a -> a
+ fold (Identity a) = a
=====================================
testsuite/tests/typecheck/should_compile/T18036a.stderr
=====================================
@@ -0,0 +1,6 @@
+
+T18036a.hs:14:13: warning: [-Wredundant-constraints]
+ • Redundant constraint: Monoid a
+ • In the type signature for:
+ fold :: forall a. Monoid a => Identity a -> a
+ In the instance declaration for ‘Fold Identity’
=====================================
testsuite/tests/typecheck/should_compile/all.T
=====================================
@@ -703,3 +703,5 @@ test('T17024', normal, compile, [''])
test('T17021a', normal, compile, [''])
test('T18005', normal, compile, [''])
test('T18023', normal, compile, [''])
+test('T18036', normal, compile, [''])
+test('T18036a', normal, compile, [''])
View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/7bfb54c815142556c027459241a07c40c964f225...f6cb3236612a2ebc0da7c61e2b528ab8da6ea630
--
View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/7bfb54c815142556c027459241a07c40c964f225...f6cb3236612a2ebc0da7c61e2b528ab8da6ea630
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