From 575c009d9e4b25384ef984c09b2c54f909693e93 Mon Sep 17 00:00:00 2001
From: Ryan Scott <ryan.gl.scott@gmail.com>
Date: Thu, 18 Jan 2018 11:06:42 -0500
Subject: [PATCH] Fix #14681 and #14682 with precision-aimed parentheses
It turns out that `Convert` was recklessly leaving off
parentheses in two places:
* Negative numeric literals
* Patterns in lambda position
This patch fixes it by adding three new functions, `isCompoundHsLit`,
`isCompoundHsOverLit`, and `isCompoundPat`, and using them in the
right places in `Convert`. While I was in town, I also sprinkled
`isCompoundPat` among some `Pat`-constructing functions in `HsUtils`
to help avoid the likelihood of this problem happening in other
places. One of these places is in `TcGenDeriv`, and sprinkling
`isCompountPat` there fixes #14682
Test Plan: make test TEST="T14681 T14682"
Reviewers: alanz, goldfire, bgamari
Reviewed By: bgamari
Subscribers: rwbarton, thomie, carter
GHC Trac Issues: #14681, #14682
Differential Revision: https://phabricator.haskell.org/D4323
---
compiler/hsSyn/Convert.hs | 17 +-
compiler/hsSyn/HsLit.hs | 26 +++
compiler/hsSyn/HsPat.hs | 55 +++++
compiler/hsSyn/HsTypes.hs | 5 +-
compiler/hsSyn/HsUtils.hs | 9 +-
compiler/typecheck/TcGenDeriv.hs | 6 +-
.../tests/deriving/should_compile/T14682.hs | 10 +
.../deriving/should_compile/T14682.stderr | 194 ++++++++++++++++++
testsuite/tests/deriving/should_compile/all.T | 1 +
testsuite/tests/th/T14681.hs | 9 +
testsuite/tests/th/T14681.stderr | 11 +
testsuite/tests/th/all.T | 1 +
12 files changed, 334 insertions(+), 10 deletions(-)
create mode 100644 testsuite/tests/deriving/should_compile/T14682.hs
create mode 100644 testsuite/tests/deriving/should_compile/T14682.stderr
create mode 100644 testsuite/tests/th/T14681.hs
create mode 100644 testsuite/tests/th/T14681.stderr
diff --git a/compiler/hsSyn/Convert.hs b/compiler/hsSyn/Convert.hs
index e8c7f0de01b3..e137b1e836e5 100644
--- a/compiler/hsSyn/Convert.hs
+++ b/compiler/hsSyn/Convert.hs
@@ -773,8 +773,17 @@ cvtl e = wrapL (cvt e)
cvt (VarE s) = do { s' <- vName s; return $ HsVar (noLoc s') }
cvt (ConE s) = do { s' <- cName s; return $ HsVar (noLoc s') }
cvt (LitE l)
- | overloadedLit l = do { l' <- cvtOverLit l; return $ HsOverLit l' }
- | otherwise = do { l' <- cvtLit l; return $ HsLit l' }
+ | overloadedLit l = go cvtOverLit HsOverLit isCompoundHsOverLit
+ | otherwise = go cvtLit HsLit isCompoundHsLit
+ where
+ go :: (Lit -> CvtM (l GhcPs))
+ -> (l GhcPs -> HsExpr GhcPs)
+ -> (l GhcPs -> Bool)
+ -> CvtM (HsExpr GhcPs)
+ go cvt_lit mk_expr is_compound_lit = do
+ l' <- cvt_lit l
+ let e' = mk_expr l'
+ return $ if is_compound_lit l' then HsPar (noLoc e') else e'
cvt (AppE x@(LamE _ _) y) = do { x' <- cvtl x; y' <- cvtl y
; return $ HsApp (mkLHsPar x') (mkLHsPar y')}
cvt (AppE x y) = do { x' <- cvtl x; y' <- cvtl y
@@ -788,8 +797,10 @@ cvtl e = wrapL (cvt e)
-- oddities that can result from zero-argument
-- lambda expressions. See #13856.
cvt (LamE ps e) = do { ps' <- cvtPats ps; e' <- cvtl e
+ ; let pats = map parenthesizeCompoundPat ps'
; return $ HsLam (mkMatchGroup FromSource
- [mkSimpleMatch LambdaExpr ps' e'])}
+ [mkSimpleMatch LambdaExpr
+ pats e'])}
cvt (LamCaseE ms) = do { ms' <- mapM (cvtMatch LambdaExpr) ms
; return $ HsLamCase (mkMatchGroup FromSource ms')
}
diff --git a/compiler/hsSyn/HsLit.hs b/compiler/hsSyn/HsLit.hs
index 7f0864ecccc1..d46ef9b44869 100644
--- a/compiler/hsSyn/HsLit.hs
+++ b/compiler/hsSyn/HsLit.hs
@@ -254,3 +254,29 @@ pmPprHsLit (HsInteger _ i _) = integer i
pmPprHsLit (HsRat _ f _) = ppr f
pmPprHsLit (HsFloatPrim _ f) = ppr f
pmPprHsLit (HsDoublePrim _ d) = ppr d
+
+-- | Returns 'True' for compound literals that will need parentheses.
+isCompoundHsLit :: HsLit x -> Bool
+isCompoundHsLit (HsChar {}) = False
+isCompoundHsLit (HsCharPrim {}) = False
+isCompoundHsLit (HsString {}) = False
+isCompoundHsLit (HsStringPrim {}) = False
+isCompoundHsLit (HsInt _ x) = il_neg x
+isCompoundHsLit (HsIntPrim _ x) = x < 0
+isCompoundHsLit (HsWordPrim _ x) = x < 0
+isCompoundHsLit (HsInt64Prim _ x) = x < 0
+isCompoundHsLit (HsWord64Prim _ x) = x < 0
+isCompoundHsLit (HsInteger _ x _) = x < 0
+isCompoundHsLit (HsRat _ x _) = fl_neg x
+isCompoundHsLit (HsFloatPrim _ x) = fl_neg x
+isCompoundHsLit (HsDoublePrim _ x) = fl_neg x
+
+-- | Returns 'True' for compound overloaded literals that will need
+-- parentheses when used in an argument position.
+isCompoundHsOverLit :: HsOverLit x -> Bool
+isCompoundHsOverLit (OverLit { ol_val = olv }) = compound_ol_val olv
+ where
+ compound_ol_val :: OverLitVal -> Bool
+ compound_ol_val (HsIntegral x) = il_neg x
+ compound_ol_val (HsFractional x) = fl_neg x
+ compound_ol_val (HsIsString {}) = False
diff --git a/compiler/hsSyn/HsPat.hs b/compiler/hsSyn/HsPat.hs
index e05d8bbf68b2..e25ff7bbcc3f 100644
--- a/compiler/hsSyn/HsPat.hs
+++ b/compiler/hsSyn/HsPat.hs
@@ -31,6 +31,7 @@ module HsPat (
looksLazyPatBind,
isBangedLPat,
hsPatNeedsParens,
+ isCompoundPat, parenthesizeCompoundPat,
isIrrefutableHsPat,
collectEvVarsPats,
@@ -659,6 +660,8 @@ case in foo to be unreachable, as GHC would mistakenly believe that Nothing'
is the only thing that could possibly be matched!
-}
+-- | Returns 'True' if a pattern must be parenthesized in order to parse
+-- (e.g., the @(x :: Int)@ in @f (x :: Int) = x@).
hsPatNeedsParens :: Pat a -> Bool
hsPatNeedsParens (NPlusKPat {}) = True
hsPatNeedsParens (SplicePat {}) = False
@@ -681,11 +684,63 @@ hsPatNeedsParens (PArrPat {}) = False
hsPatNeedsParens (LitPat {}) = False
hsPatNeedsParens (NPat {}) = False
+-- | Returns 'True' if a constructor pattern must be parenthesized in order
+-- to parse.
conPatNeedsParens :: HsConDetails a b -> Bool
conPatNeedsParens (PrefixCon {}) = False
conPatNeedsParens (InfixCon {}) = True
conPatNeedsParens (RecCon {}) = False
+-- | Returns 'True' for compound patterns that need parentheses when used in
+-- an argument position.
+--
+-- Note that this is different from 'hsPatNeedsParens', which only says if
+-- a pattern needs to be parenthesized to parse in /any/ position, whereas
+-- 'isCompountPat' says if a pattern needs to be parenthesized in an /argument/
+-- position. In other words, @'hsPatNeedsParens' x@ implies
+-- @'isCompoundPat' x@, but not necessarily the other way around.
+isCompoundPat :: Pat a -> Bool
+isCompoundPat (NPlusKPat {}) = True
+isCompoundPat (SplicePat {}) = False
+isCompoundPat (ConPatIn _ ds) = isCompoundConPat ds
+isCompoundPat p@(ConPatOut {}) = isCompoundConPat (pat_args p)
+isCompoundPat (SigPatIn {}) = True
+isCompoundPat (SigPatOut {}) = True
+isCompoundPat (ViewPat {}) = True
+isCompoundPat (CoPat _ p _) = isCompoundPat p
+isCompoundPat (WildPat {}) = False
+isCompoundPat (VarPat {}) = False
+isCompoundPat (LazyPat {}) = False
+isCompoundPat (BangPat {}) = False
+isCompoundPat (ParPat {}) = False
+isCompoundPat (AsPat {}) = False
+isCompoundPat (TuplePat {}) = False
+isCompoundPat (SumPat {}) = False
+isCompoundPat (ListPat {}) = False
+isCompoundPat (PArrPat {}) = False
+isCompoundPat (LitPat p) = isCompoundHsLit p
+isCompoundPat (NPat (L _ p) _ _ _) = isCompoundHsOverLit p
+
+-- | Returns 'True' for compound constructor patterns that need parentheses
+-- when used in an argument position.
+--
+-- Note that this is different from 'conPatNeedsParens', which only says if
+-- a constructor pattern needs to be parenthesized to parse in /any/ position,
+-- whereas 'isCompountConPat' says if a pattern needs to be parenthesized in an
+-- /argument/ position. In other words, @'conPatNeedsParens' x@ implies
+-- @'isCompoundConPat' x@, but not necessarily the other way around.
+isCompoundConPat :: HsConDetails a b -> Bool
+isCompoundConPat (PrefixCon args) = not (null args)
+isCompoundConPat (InfixCon {}) = True
+isCompoundConPat (RecCon {}) = False
+
+-- | @'parenthesizeCompoundPat' p@ checks if @'isCompoundPat' p@ is true, and
+-- if so, surrounds @p@ with a 'ParPat'. Otherwise, it simply returns @p@.
+parenthesizeCompoundPat :: LPat p -> LPat p
+parenthesizeCompoundPat lp@(L loc p)
+ | isCompoundPat p = L loc (ParPat lp)
+ | otherwise = lp
+
{-
% Collect all EvVars from all constructor patterns
-}
diff --git a/compiler/hsSyn/HsTypes.hs b/compiler/hsSyn/HsTypes.hs
index 602140b065c2..650367013006 100644
--- a/compiler/hsSyn/HsTypes.hs
+++ b/compiler/hsSyn/HsTypes.hs
@@ -1351,7 +1351,8 @@ ppr_tylit (HsNumTy _ i) = integer i
ppr_tylit (HsStrTy _ s) = text (show s)
--- | Return True for compound types that will need parens.
+-- | Return 'True' for compound types that will need parentheses when used in
+-- an argument position.
isCompoundHsType :: LHsType pass -> Bool
isCompoundHsType (L _ HsAppTy{} ) = True
isCompoundHsType (L _ HsAppsTy{}) = True
@@ -1361,7 +1362,7 @@ isCompoundHsType (L _ HsOpTy{} ) = True
isCompoundHsType _ = False
-- | @'parenthesizeCompoundHsType' ty@ checks if @'isCompoundHsType' ty@ is
--- true, and if so, surrounds it with an 'HsParTy'. Otherwise, it simply
+-- true, and if so, surrounds @ty@ with an 'HsParTy'. Otherwise, it simply
-- returns @ty@.
parenthesizeCompoundHsType :: LHsType pass -> LHsType pass
parenthesizeCompoundHsType ty@(L loc _)
diff --git a/compiler/hsSyn/HsUtils.hs b/compiler/hsSyn/HsUtils.hs
index 6db21331a063..2937c1a65712 100644
--- a/compiler/hsSyn/HsUtils.hs
+++ b/compiler/hsSyn/HsUtils.hs
@@ -190,7 +190,8 @@ mkHsLam :: [LPat GhcPs] -> LHsExpr GhcPs -> LHsExpr GhcPs
mkHsLam pats body = mkHsPar (L (getLoc body) (HsLam matches))
where
matches = mkMatchGroup Generated
- [mkSimpleMatch LambdaExpr pats body]
+ [mkSimpleMatch LambdaExpr pats' body]
+ pats' = map parenthesizeCompoundPat pats
mkHsLams :: [TyVar] -> [EvVar] -> LHsExpr GhcTc -> LHsExpr GhcTc
mkHsLams tyvars dicts expr = mkLHsWrap (mkWpTyLams tyvars
@@ -430,10 +431,12 @@ nlInfixConPat :: IdP id -> LPat id -> LPat id -> LPat id
nlInfixConPat con l r = noLoc (ConPatIn (noLoc con) (InfixCon l r))
nlConPat :: RdrName -> [LPat GhcPs] -> LPat GhcPs
-nlConPat con pats = noLoc (ConPatIn (noLoc con) (PrefixCon pats))
+nlConPat con pats =
+ noLoc (ConPatIn (noLoc con) (PrefixCon (map parenthesizeCompoundPat pats)))
nlConPatName :: Name -> [LPat GhcRn] -> LPat GhcRn
-nlConPatName con pats = noLoc (ConPatIn (noLoc con) (PrefixCon pats))
+nlConPatName con pats =
+ noLoc (ConPatIn (noLoc con) (PrefixCon (map parenthesizeCompoundPat pats)))
nlNullaryConPat :: IdP id -> LPat id
nlNullaryConPat con = noLoc (ConPatIn (noLoc con) (PrefixCon []))
diff --git a/compiler/typecheck/TcGenDeriv.hs b/compiler/typecheck/TcGenDeriv.hs
index d9166e5e002a..b2d45fda6d12 100644
--- a/compiler/typecheck/TcGenDeriv.hs
+++ b/compiler/typecheck/TcGenDeriv.hs
@@ -1849,7 +1849,8 @@ mkFunBindSE :: Arity -> SrcSpan -> RdrName
mkFunBindSE arity loc fun pats_and_exprs
= mkRdrFunBindSE arity (L loc fun) matches
where
- matches = [mkMatch (mkPrefixFunRhs (L loc fun)) p e
+ matches = [mkMatch (mkPrefixFunRhs (L loc fun))
+ (map parenthesizeCompoundPat p) e
(noLoc emptyLocalBinds)
| (p,e) <-pats_and_exprs]
@@ -1869,7 +1870,8 @@ mkFunBindEC :: Arity -> SrcSpan -> RdrName
mkFunBindEC arity loc fun catch_all pats_and_exprs
= mkRdrFunBindEC arity catch_all (L loc fun) matches
where
- matches = [ mkMatch (mkPrefixFunRhs (L loc fun)) p e
+ matches = [ mkMatch (mkPrefixFunRhs (L loc fun))
+ (map parenthesizeCompoundPat p) e
(noLoc emptyLocalBinds)
| (p,e) <- pats_and_exprs ]
diff --git a/testsuite/tests/deriving/should_compile/T14682.hs b/testsuite/tests/deriving/should_compile/T14682.hs
new file mode 100644
index 000000000000..8f8161f00f32
--- /dev/null
+++ b/testsuite/tests/deriving/should_compile/T14682.hs
@@ -0,0 +1,10 @@
+{-# LANGUAGE DeriveDataTypeable #-}
+{-# LANGUAGE DeriveLift #-}
+module T14682 where
+
+import Data.Data
+import Data.Ix
+import Language.Haskell.TH.Syntax
+
+data Foo = Foo Int Int
+ deriving (Show, Lift, Data, Eq, Ord, Ix)
diff --git a/testsuite/tests/deriving/should_compile/T14682.stderr b/testsuite/tests/deriving/should_compile/T14682.stderr
new file mode 100644
index 000000000000..6ff285fbef96
--- /dev/null
+++ b/testsuite/tests/deriving/should_compile/T14682.stderr
@@ -0,0 +1,194 @@
+
+==================== Derived instances ====================
+Derived class instances:
+ instance GHC.Show.Show T14682.Foo where
+ GHC.Show.showsPrec a (T14682.Foo b1 b2)
+ = GHC.Show.showParen
+ (a GHC.Classes.>= 11)
+ ((GHC.Base..)
+ (GHC.Show.showString "Foo ")
+ ((GHC.Base..)
+ (GHC.Show.showsPrec 11 b1)
+ ((GHC.Base..) GHC.Show.showSpace (GHC.Show.showsPrec 11 b2))))
+
+ instance Language.Haskell.TH.Syntax.Lift T14682.Foo where
+ Language.Haskell.TH.Syntax.lift (T14682.Foo a1 a2)
+ = Language.Haskell.TH.Lib.Internal.appE
+ (Language.Haskell.TH.Lib.Internal.appE
+ (Language.Haskell.TH.Lib.Internal.conE
+ (Language.Haskell.TH.Syntax.mkNameG_d "main" "T14682" "Foo"))
+ (Language.Haskell.TH.Syntax.lift a1))
+ (Language.Haskell.TH.Syntax.lift a2)
+
+ instance Data.Data.Data T14682.Foo where
+ Data.Data.gfoldl k z (T14682.Foo a1 a2)
+ = ((z T14682.Foo `k` a1) `k` a2)
+ Data.Data.gunfold k z _ = k (k (z T14682.Foo))
+ Data.Data.toConstr (T14682.Foo _ _) = T14682.$cFoo
+ Data.Data.dataTypeOf _ = T14682.$tFoo
+
+ instance GHC.Classes.Eq T14682.Foo where
+ (GHC.Classes.==) (T14682.Foo a1 a2) (T14682.Foo b1 b2)
+ = (((a1 GHC.Classes.== b1))
+ GHC.Classes.&& ((a2 GHC.Classes.== b2)))
+
+ instance GHC.Classes.Ord T14682.Foo where
+ GHC.Classes.compare a b
+ = case a of {
+ T14682.Foo a1 a2
+ -> case b of {
+ T14682.Foo b1 b2
+ -> case (GHC.Classes.compare a1 b1) of
+ GHC.Types.LT -> GHC.Types.LT
+ GHC.Types.EQ -> (a2 `GHC.Classes.compare` b2)
+ GHC.Types.GT -> GHC.Types.GT } }
+ (GHC.Classes.<) a b
+ = case a of {
+ T14682.Foo a1 a2
+ -> case b of {
+ T14682.Foo b1 b2
+ -> case (GHC.Classes.compare a1 b1) of
+ GHC.Types.LT -> GHC.Types.True
+ GHC.Types.EQ -> (a2 GHC.Classes.< b2)
+ GHC.Types.GT -> GHC.Types.False } }
+ (GHC.Classes.<=) a b = GHC.Classes.not ((GHC.Classes.<) b a)
+ (GHC.Classes.>) a b = (GHC.Classes.<) b a
+ (GHC.Classes.>=) a b = GHC.Classes.not ((GHC.Classes.<) a b)
+
+ instance GHC.Arr.Ix T14682.Foo where
+ GHC.Arr.range (T14682.Foo a1 a2, T14682.Foo b1 b2)
+ = [T14682.Foo c1 c2 |
+ c1 <- GHC.Arr.range (a1, b1), c2 <- GHC.Arr.range (a2, b2)]
+ GHC.Arr.unsafeIndex
+ (T14682.Foo a1 a2, T14682.Foo b1 b2)
+ T14682.Foo c1 c2
+ = (GHC.Arr.unsafeIndex (a2, b2) c2
+ GHC.Num.+
+ (GHC.Arr.unsafeRangeSize (a2, b2)
+ GHC.Num.* GHC.Arr.unsafeIndex (a1, b1) c1))
+ GHC.Arr.inRange
+ (T14682.Foo a1 a2, T14682.Foo b1 b2)
+ T14682.Foo c1 c2
+ = (GHC.Arr.inRange (a1, b1) c1
+ GHC.Classes.&& GHC.Arr.inRange (a2, b2) c2)
+
+ T14682.$con2tag_B4iUvrAY4wB3YczpMJQUOX ::
+ T14682.Foo -> GHC.Prim.Int#
+ T14682.$con2tag_B4iUvrAY4wB3YczpMJQUOX (T14682.Foo _ _) = 0#
+ T14682.$tFoo :: Data.Data.DataType
+ T14682.$cFoo :: Data.Data.Constr
+ T14682.$tFoo = Data.Data.mkDataType "Foo" [T14682.$cFoo]
+ T14682.$cFoo
+ = Data.Data.mkConstr T14682.$tFoo "Foo" [] Data.Data.Prefix
+
+Derived type family instances:
+
+
+
+==================== Filling in method body ====================
+GHC.Show.Show [T14682.Foo]
+ GHC.Show.show = GHC.Show.$dmshow @(T14682.Foo)
+
+
+
+==================== Filling in method body ====================
+GHC.Show.Show [T14682.Foo]
+ GHC.Show.showList = GHC.Show.$dmshowList @(T14682.Foo)
+
+
+
+==================== Filling in method body ====================
+Data.Data.Data [T14682.Foo]
+ Data.Data.dataCast1 = Data.Data.$dmdataCast1 @(T14682.Foo)
+
+
+
+==================== Filling in method body ====================
+Data.Data.Data [T14682.Foo]
+ Data.Data.dataCast2 = Data.Data.$dmdataCast2 @(T14682.Foo)
+
+
+
+==================== Filling in method body ====================
+Data.Data.Data [T14682.Foo]
+ Data.Data.gmapT = Data.Data.$dmgmapT @(T14682.Foo)
+
+
+
+==================== Filling in method body ====================
+Data.Data.Data [T14682.Foo]
+ Data.Data.gmapQl = Data.Data.$dmgmapQl @(T14682.Foo)
+
+
+
+==================== Filling in method body ====================
+Data.Data.Data [T14682.Foo]
+ Data.Data.gmapQr = Data.Data.$dmgmapQr @(T14682.Foo)
+
+
+
+==================== Filling in method body ====================
+Data.Data.Data [T14682.Foo]
+ Data.Data.gmapQ = Data.Data.$dmgmapQ @(T14682.Foo)
+
+
+
+==================== Filling in method body ====================
+Data.Data.Data [T14682.Foo]
+ Data.Data.gmapQi = Data.Data.$dmgmapQi @(T14682.Foo)
+
+
+
+==================== Filling in method body ====================
+Data.Data.Data [T14682.Foo]
+ Data.Data.gmapM = Data.Data.$dmgmapM @(T14682.Foo)
+
+
+
+==================== Filling in method body ====================
+Data.Data.Data [T14682.Foo]
+ Data.Data.gmapMp = Data.Data.$dmgmapMp @(T14682.Foo)
+
+
+
+==================== Filling in method body ====================
+Data.Data.Data [T14682.Foo]
+ Data.Data.gmapMo = Data.Data.$dmgmapMo @(T14682.Foo)
+
+
+
+==================== Filling in method body ====================
+GHC.Classes.Eq [T14682.Foo]
+ GHC.Classes./= = GHC.Classes.$dm/= @(T14682.Foo)
+
+
+
+==================== Filling in method body ====================
+GHC.Classes.Ord [T14682.Foo]
+ GHC.Classes.max = GHC.Classes.$dmmax @(T14682.Foo)
+
+
+
+==================== Filling in method body ====================
+GHC.Classes.Ord [T14682.Foo]
+ GHC.Classes.min = GHC.Classes.$dmmin @(T14682.Foo)
+
+
+
+==================== Filling in method body ====================
+GHC.Arr.Ix [T14682.Foo]
+ GHC.Arr.index = GHC.Arr.$dmindex @(T14682.Foo)
+
+
+
+==================== Filling in method body ====================
+GHC.Arr.Ix [T14682.Foo]
+ GHC.Arr.rangeSize = GHC.Arr.$dmrangeSize @(T14682.Foo)
+
+
+
+==================== Filling in method body ====================
+GHC.Arr.Ix [T14682.Foo]
+ GHC.Arr.unsafeRangeSize = GHC.Arr.$dmunsafeRangeSize @(T14682.Foo)
+
+
diff --git a/testsuite/tests/deriving/should_compile/all.T b/testsuite/tests/deriving/should_compile/all.T
index 8752bbdb737d..3360c81850e5 100644
--- a/testsuite/tests/deriving/should_compile/all.T
+++ b/testsuite/tests/deriving/should_compile/all.T
@@ -100,3 +100,4 @@ test('T14339', normal, compile, [''])
test('T14331', normal, compile, [''])
test('T14578', normal, compile, ['-ddump-deriv -dsuppress-uniques'])
test('T14579', normal, compile, [''])
+test('T14682', normal, compile, ['-ddump-deriv -dsuppress-uniques'])
diff --git a/testsuite/tests/th/T14681.hs b/testsuite/tests/th/T14681.hs
new file mode 100644
index 000000000000..341a1a66b10c
--- /dev/null
+++ b/testsuite/tests/th/T14681.hs
@@ -0,0 +1,9 @@
+{-# LANGUAGE TemplateHaskell #-}
+module T14681 where
+
+import Data.Functor.Identity
+import Language.Haskell.TH
+
+$([d| f = \(Identity x) -> x |])
+$([d| g = $(pure $ VarE '(+) `AppE` LitE (IntegerL (-1))
+ `AppE` (LitE (IntegerL (-1)))) |])
diff --git a/testsuite/tests/th/T14681.stderr b/testsuite/tests/th/T14681.stderr
new file mode 100644
index 000000000000..debb18dee55a
--- /dev/null
+++ b/testsuite/tests/th/T14681.stderr
@@ -0,0 +1,11 @@
+T14681.hs:7:3-31: Splicing declarations
+ [d| f = \ (Identity x) -> x |] ======> f = \ (Identity x) -> x
+T14681.hs:(8,3)-(9,62): Splicing declarations
+ [d| g = $(pure
+ $ VarE '(+) `AppE` LitE (IntegerL (- 1))
+ `AppE` (LitE (IntegerL (- 1)))) |]
+ pending(rn) [<splice, pure
+ $ VarE '(+) `AppE` LitE (IntegerL (- 1))
+ `AppE` (LitE (IntegerL (- 1)))>]
+ ======>
+ g = ((+) (-1)) (-1)
diff --git a/testsuite/tests/th/all.T b/testsuite/tests/th/all.T
index 2e7ffa3368a6..41567162e89a 100644
--- a/testsuite/tests/th/all.T
+++ b/testsuite/tests/th/all.T
@@ -398,3 +398,4 @@ test('T13968', normal, compile_fail, ['-v0'])
test('T14204', normal, compile_fail, ['-v0'])
test('T14060', normal, compile_and_run, ['-v0'])
test('T14646', normal, compile, ['-v0 -ddump-splices -dsuppress-uniques'])
+test('T14681', normal, compile, ['-v0 -ddump-splices -dsuppress-uniques'])
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