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| author | Simon Peyton Jones <simonpj@microsoft.com> | 2019-09-20 23:26:38 +0100 |
|---|---|---|
| committer | Marge Bot <ben+marge-bot@smart-cactus.org> | 2019-10-12 13:35:24 -0400 |
| commit | c50e4c92d28752beec955d1e3486065685d2f7e6 (patch) | |
| tree | 9fd170ac96e7a48a542a9706ad9da7b185757314 /testsuite/tests | |
| parent | 0a338264054a518ddc2ab7920af4489a38c8a214 (diff) | |
| download | haskell-c50e4c92d28752beec955d1e3486065685d2f7e6.tar.gz | |
Fix validity checking for inferred types
GHC is suposed to uphold the principle that an /inferred/ type
for a let-binding should obey the rules for that module. E.g.
we should only accept an inferred higher rank type if we have
RankNTypes on.
But we were failing to check this: TcValidity.checkValidType
allowed arbitrary rank for inferred types.
This patch fixes the bug. It might in principle cause some breakage,
but if so that's good: the user should add RankNTypes and/or a
manual signature. (And almost every package has explicit user
signatures for all top-level things anyway.) Let's see.
Fixes #17213.
Metric Decrease:
T10370
Diffstat (limited to 'testsuite/tests')
4 files changed, 17 insertions, 0 deletions
diff --git a/testsuite/tests/typecheck/should_fail/T17213.hs b/testsuite/tests/typecheck/should_fail/T17213.hs new file mode 100644 index 0000000000..e9c093c903 --- /dev/null +++ b/testsuite/tests/typecheck/should_fail/T17213.hs @@ -0,0 +1,5 @@ +module T17213 where + +import T17213a + +g = foo diff --git a/testsuite/tests/typecheck/should_fail/T17213.stderr b/testsuite/tests/typecheck/should_fail/T17213.stderr new file mode 100644 index 0000000000..1172992660 --- /dev/null +++ b/testsuite/tests/typecheck/should_fail/T17213.stderr @@ -0,0 +1,6 @@ + +T17213.hs:5:1: error: + • Illegal polymorphic type: forall a. a -> a + Perhaps you intended to use RankNTypes + • When checking the inferred type + g :: (forall a. a -> a) -> Int diff --git a/testsuite/tests/typecheck/should_fail/T17213a.hs b/testsuite/tests/typecheck/should_fail/T17213a.hs new file mode 100644 index 0000000000..48537600d5 --- /dev/null +++ b/testsuite/tests/typecheck/should_fail/T17213a.hs @@ -0,0 +1,5 @@ +{-# LANGUAGE RankNTypes #-} +module T17213a where + +foo :: (forall a. a->a)-> Int +foo x = error "ukr" diff --git a/testsuite/tests/typecheck/should_fail/all.T b/testsuite/tests/typecheck/should_fail/all.T index 4ccde2163f..6b66d41975 100644 --- a/testsuite/tests/typecheck/should_fail/all.T +++ b/testsuite/tests/typecheck/should_fail/all.T @@ -543,3 +543,4 @@ test('UnliftedNewtypesMismatchedKindRecord', normal, compile_fail, ['']) test('UnliftedNewtypesMultiFieldGadt', normal, compile_fail, ['']) test('T13834', normal, compile_fail, ['']) test('T17077', normal, compile_fail, ['']) +test('T17213', [extra_files(['T17213a.hs'])], multimod_compile_fail, ['T17213', '-v0']) |