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| author | sheaf <sam.derbyshire@gmail.com> | 2023-02-07 15:10:30 +0100 |
|---|---|---|
| committer | Marge Bot <ben+marge-bot@smart-cactus.org> | 2023-02-14 11:31:49 -0500 |
| commit | 9fb4ca89bff9873e5f6a6849fa22a349c94deaae (patch) | |
| tree | e85819a1fa5c8a761dacb5e04e636b0da9555626 /testsuite/tests/quantified-constraints | |
| parent | d6411d6cddb8c94c74e5834f0199370d189d31a2 (diff) | |
| download | haskell-9fb4ca89bff9873e5f6a6849fa22a349c94deaae.tar.gz | |
Introduce warning for loopy superclass solve
Commit aed1974e completely re-engineered the treatment of loopy
superclass dictionaries in instance declarations. Unfortunately,
it has the potential to break (albeit in a rather minor way) user code.
To alleviate migration concerns, this commit re-introduces the old
behaviour. Any reliance on this old behaviour triggers a warning,
controlled by `-Wloopy-superclass-solve`. The warning text explains
that GHC might produce bottoming evidence, and provides a migration
strategy.
This allows us to provide a graceful migration period, alerting users
when they are relying on this unsound behaviour.
Fixes #22912 #22891 #20666 #22894 #22905
Diffstat (limited to 'testsuite/tests/quantified-constraints')
| -rw-r--r-- | testsuite/tests/quantified-constraints/all.T | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/testsuite/tests/quantified-constraints/all.T b/testsuite/tests/quantified-constraints/all.T index b3d0eb920f..d3bfe6e07e 100644 --- a/testsuite/tests/quantified-constraints/all.T +++ b/testsuite/tests/quantified-constraints/all.T @@ -41,3 +41,4 @@ test('T22216d', normal, compile, ['']) test('T22216e', normal, compile, ['']) test('T22223', normal, compile, ['']) test('T19690', normal, compile_fail, ['']) + |