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| author | Ryan Scott <ryan.gl.scott@gmail.com> | 2020-09-18 19:39:54 -0400 |
|---|---|---|
| committer | Marge Bot <ben+marge-bot@smart-cactus.org> | 2020-09-21 16:45:47 -0400 |
| commit | 2f222b120e48df1b3d78f5501612d21c2a2dc470 (patch) | |
| tree | 404dda6df93d8d3d72a23263ea78e5035fc9b97a /testsuite | |
| parent | 1a0f8243efc9873a949bb6f082b4dfdf563fc1ea (diff) | |
| download | haskell-2f222b120e48df1b3d78f5501612d21c2a2dc470.tar.gz | |
Disallow constraints in KindSigCtxt
This patch cleans up how `GHC.Tc.Validity` classifies `UserTypeCtxt`s
that can only refer to kind-level positions, which is important for
rejecting certain classes of programs. In particular, this patch:
* Introduces a new `TypeOrKindCtxt` data type and
`typeOrKindCtxt :: UserTypeCtxt -> TypeOrKindCtxt` function, which
determines whether a `UserTypeCtxt` can refer to type-level
contexts, kind-level contexts, or both.
* Defines the existing `allConstraintsAllowed` and `vdqAllowed`
functions in terms of `typeOrKindCtxt`, which avoids code
duplication and ensures that they stay in sync in the future.
The net effect of this patch is that it fixes #18714, in which it was
discovered that `allConstraintsAllowed` incorrectly returned `True`
for `KindSigCtxt`. Because `typeOrKindCtxt` now correctly classifies
`KindSigCtxt` as a kind-level context, this bug no longer occurs.
Diffstat (limited to 'testsuite')
| -rw-r--r-- | testsuite/tests/typecheck/should_fail/T18714.hs | 11 | ||||
| -rw-r--r-- | testsuite/tests/typecheck/should_fail/T18714.stderr | 7 | ||||
| -rw-r--r-- | testsuite/tests/typecheck/should_fail/all.T | 1 |
3 files changed, 19 insertions, 0 deletions
diff --git a/testsuite/tests/typecheck/should_fail/T18714.hs b/testsuite/tests/typecheck/should_fail/T18714.hs new file mode 100644 index 0000000000..9a111a2cc2 --- /dev/null +++ b/testsuite/tests/typecheck/should_fail/T18714.hs @@ -0,0 +1,11 @@ +{-# LANGUAGE DataKinds #-} +{-# LANGUAGE ImpredicativeTypes #-} +{-# LANGUAGE PolyKinds #-} +{-# LANGUAGE RankNTypes #-} +module T18714 where + +import GHC.Exts + +type Id a = a + +type F = Id (Any :: forall a. Show a => a -> a) diff --git a/testsuite/tests/typecheck/should_fail/T18714.stderr b/testsuite/tests/typecheck/should_fail/T18714.stderr new file mode 100644 index 0000000000..e038e603e1 --- /dev/null +++ b/testsuite/tests/typecheck/should_fail/T18714.stderr @@ -0,0 +1,7 @@ + +T18714.hs:11:14: error: + • Illegal constraint in a kind: forall a. Show a => a -> a + • In the first argument of ‘Id’, namely + ‘(Any :: forall a. Show a => a -> a)’ + In the type ‘Id (Any :: forall a. Show a => a -> a)’ + In the type declaration for ‘F’ diff --git a/testsuite/tests/typecheck/should_fail/all.T b/testsuite/tests/typecheck/should_fail/all.T index 49a3cb8cec..6b10777f12 100644 --- a/testsuite/tests/typecheck/should_fail/all.T +++ b/testsuite/tests/typecheck/should_fail/all.T @@ -579,3 +579,4 @@ test('T18357a', normal, compile_fail, ['']) test('T18357b', normal, compile_fail, ['']) test('T18455', normal, compile_fail, ['']) test('T18534', normal, compile_fail, ['']) +test('T18714', normal, compile_fail, ['']) |