Fix loop in the interface representation of some `Unfolding` fields

As discovered in #22272, dehydration of the unfolding info of a
recursive definition used to involve a traversal of the definition
itself, which in turn involves traversing the unfolding info. Hence,
a loop.

Instead, we now store enough data in the interface that we can produce
the unfolding info without this traversal. See Note [Tying the 'CoreUnfolding' knot]
for details.

Fixes #22272

Co-authored-by: Simon Peyton Jones <simon.peytonjones@gmail.com>

9 files changed, 108 insertions, 68 deletions

diff --git a/testsuite/tests/deSugar/should_compile/T13208.stdout b/testsuite/tests/deSugar/should_compile/T13208.stdout
index b7ba07cdf4..f018ac1a2c 100644
--- a/testsuite/tests/deSugar/should_compile/T13208.stdout
+++ b/testsuite/tests/deSugar/should_compile/T13208.stdout
@@ -1,6 +1,6 @@
- Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
-         WorkFree=True, Expandable=True,
+ Unf=Unf{Src=<vanilla>, TopLvl=True,
+         Value=True, ConLike=True, WorkFree=True, Expandable=True,
          Guidance=ALWAYS_IF(arity=1,unsat_ok=True,boring_ok=True)}]
 f = \ (@p) _ [Occ=Dead] -> GHC.Types.True
- Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
-         WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 80 10}]
+ Unf=Unf{Src=<vanilla>, TopLvl=True,
+         Value=True, ConLike=True, WorkFree=True, Expandable=True,
diff --git a/testsuite/tests/numeric/should_compile/T14170.stdout b/testsuite/tests/numeric/should_compile/T14170.stdout
index 286d60bc0a..197cccc422 100644
--- a/testsuite/tests/numeric/should_compile/T14170.stdout
+++ b/testsuite/tests/numeric/should_compile/T14170.stdout
@@ -6,44 +6,50 @@ Result size of Tidy Core
 -- RHS size: {terms: 1, types: 0, coercions: 0, joins: 0/0}
 NatVal.$trModule4 :: GHC.Prim.Addr#
 [GblId,
- Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
-         WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 20 0}]
+ Unf=Unf{Src=<vanilla>, TopLvl=True,
+         Value=True, ConLike=True, WorkFree=True, Expandable=True,
+         Guidance=IF_ARGS [] 20 0}]
 NatVal.$trModule4 = "main"#
 
 -- RHS size: {terms: 2, types: 0, coercions: 0, joins: 0/0}
 NatVal.$trModule3 :: GHC.Types.TrName
 [GblId,
- Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
-         WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 10 10}]
+ Unf=Unf{Src=<vanilla>, TopLvl=True,
+         Value=True, ConLike=True, WorkFree=True, Expandable=True,
+         Guidance=IF_ARGS [] 10 10}]
 NatVal.$trModule3 = GHC.Types.TrNameS NatVal.$trModule4
 
 -- RHS size: {terms: 1, types: 0, coercions: 0, joins: 0/0}
 NatVal.$trModule2 :: GHC.Prim.Addr#
 [GblId,
- Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
-         WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 30 0}]
+ Unf=Unf{Src=<vanilla>, TopLvl=True,
+         Value=True, ConLike=True, WorkFree=True, Expandable=True,
+         Guidance=IF_ARGS [] 30 0}]
 NatVal.$trModule2 = "NatVal"#
 
 -- RHS size: {terms: 2, types: 0, coercions: 0, joins: 0/0}
 NatVal.$trModule1 :: GHC.Types.TrName
 [GblId,
- Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
-         WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 10 10}]
+ Unf=Unf{Src=<vanilla>, TopLvl=True,
+         Value=True, ConLike=True, WorkFree=True, Expandable=True,
+         Guidance=IF_ARGS [] 10 10}]
 NatVal.$trModule1 = GHC.Types.TrNameS NatVal.$trModule2
 
 -- RHS size: {terms: 3, types: 0, coercions: 0, joins: 0/0}
 NatVal.$trModule :: GHC.Types.Module
 [GblId,
- Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
-         WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 10 10}]
+ Unf=Unf{Src=<vanilla>, TopLvl=True,
+         Value=True, ConLike=True, WorkFree=True, Expandable=True,
+         Guidance=IF_ARGS [] 10 10}]
 NatVal.$trModule
   = GHC.Types.Module NatVal.$trModule3 NatVal.$trModule1
 
 -- RHS size: {terms: 2, types: 0, coercions: 0, joins: 0/0}
 foo :: Integer
 [GblId,
- Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
-         WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 10 10}]
+ Unf=Unf{Src=<vanilla>, TopLvl=True,
+         Value=True, ConLike=True, WorkFree=True, Expandable=True,
+         Guidance=IF_ARGS [] 10 10}]
 foo = GHC.Num.Integer.IS 0#
 
 
diff --git a/testsuite/tests/numeric/should_compile/T14465.stdout b/testsuite/tests/numeric/should_compile/T14465.stdout
index 7ce467bc60..afac0e2c94 100644
--- a/testsuite/tests/numeric/should_compile/T14465.stdout
+++ b/testsuite/tests/numeric/should_compile/T14465.stdout
@@ -6,43 +6,49 @@ Result size of Tidy Core
 -- RHS size: {terms: 2, types: 0, coercions: 0, joins: 0/0}
 ten :: Natural
 [GblId,
- Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
-         WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 10 10}]
+ Unf=Unf{Src=<vanilla>, TopLvl=True,
+         Value=True, ConLike=True, WorkFree=True, Expandable=True,
+         Guidance=IF_ARGS [] 10 10}]
 ten = GHC.Num.Natural.NS 10##
 
 -- RHS size: {terms: 1, types: 0, coercions: 0, joins: 0/0}
 M.$trModule4 :: GHC.Prim.Addr#
 [GblId,
- Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
-         WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 20 0}]
+ Unf=Unf{Src=<vanilla>, TopLvl=True,
+         Value=True, ConLike=True, WorkFree=True, Expandable=True,
+         Guidance=IF_ARGS [] 20 0}]
 M.$trModule4 = "main"#
 
 -- RHS size: {terms: 2, types: 0, coercions: 0, joins: 0/0}
 M.$trModule3 :: GHC.Types.TrName
 [GblId,
- Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
-         WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 10 10}]
+ Unf=Unf{Src=<vanilla>, TopLvl=True,
+         Value=True, ConLike=True, WorkFree=True, Expandable=True,
+         Guidance=IF_ARGS [] 10 10}]
 M.$trModule3 = GHC.Types.TrNameS M.$trModule4
 
 -- RHS size: {terms: 1, types: 0, coercions: 0, joins: 0/0}
 M.$trModule2 :: GHC.Prim.Addr#
 [GblId,
- Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
-         WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 20 0}]
+ Unf=Unf{Src=<vanilla>, TopLvl=True,
+         Value=True, ConLike=True, WorkFree=True, Expandable=True,
+         Guidance=IF_ARGS [] 20 0}]
 M.$trModule2 = "M"#
 
 -- RHS size: {terms: 2, types: 0, coercions: 0, joins: 0/0}
 M.$trModule1 :: GHC.Types.TrName
 [GblId,
- Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
-         WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 10 10}]
+ Unf=Unf{Src=<vanilla>, TopLvl=True,
+         Value=True, ConLike=True, WorkFree=True, Expandable=True,
+         Guidance=IF_ARGS [] 10 10}]
 M.$trModule1 = GHC.Types.TrNameS M.$trModule2
 
 -- RHS size: {terms: 3, types: 0, coercions: 0, joins: 0/0}
 M.$trModule :: GHC.Types.Module
 [GblId,
- Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
-         WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 10 10}]
+ Unf=Unf{Src=<vanilla>, TopLvl=True,
+         Value=True, ConLike=True, WorkFree=True, Expandable=True,
+         Guidance=IF_ARGS [] 10 10}]
 M.$trModule = GHC.Types.Module M.$trModule3 M.$trModule1
 
 -- RHS size: {terms: 1, types: 1, coercions: 0, joins: 0/0}
@@ -50,23 +56,25 @@ minusOne :: Natural
 [GblId,
  Str=b,
  Cpr=b,
- Unf=Unf{Src=<vanilla>, TopLvl=True, Value=False, ConLike=False,
-         WorkFree=True, Expandable=True,
+ Unf=Unf{Src=<vanilla>, TopLvl=True,
+         Value=False, ConLike=False, WorkFree=True, Expandable=True,
          Guidance=ALWAYS_IF(arity=0,unsat_ok=True,boring_ok=True)}]
 minusOne = GHC.Prim.Exception.raiseUnderflow @Natural
 
 -- RHS size: {terms: 2, types: 0, coercions: 0, joins: 0/0}
 twoTimesTwo :: Natural
 [GblId,
- Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
-         WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 10 10}]
+ Unf=Unf{Src=<vanilla>, TopLvl=True,
+         Value=True, ConLike=True, WorkFree=True, Expandable=True,
+         Guidance=IF_ARGS [] 10 10}]
 twoTimesTwo = GHC.Num.Natural.NS 4##
 
 -- RHS size: {terms: 2, types: 0, coercions: 0, joins: 0/0}
 M.one1 :: Natural
 [GblId,
- Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
-         WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 10 10}]
+ Unf=Unf{Src=<vanilla>, TopLvl=True,
+         Value=True, ConLike=True, WorkFree=True, Expandable=True,
+         Guidance=IF_ARGS [] 10 10}]
 M.one1 = GHC.Num.Natural.NS 1##
 
 -- RHS size: {terms: 4, types: 1, coercions: 0, joins: 0/0}
@@ -74,15 +82,16 @@ plusOne :: Natural -> Natural
 [GblId,
  Arity=1,
  Str=<1L>,
- Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
-         WorkFree=True, Expandable=True, Guidance=IF_ARGS [0] 30 0}]
+ Unf=Unf{Src=<vanilla>, TopLvl=True,
+         Value=True, ConLike=True, WorkFree=True, Expandable=True,
+         Guidance=IF_ARGS [0] 30 0}]
 plusOne = \ (n :: Natural) -> naturalAdd n M.one1
 
 -- RHS size: {terms: 1, types: 0, coercions: 0, joins: 0/0}
 one :: Natural
 [GblId,
- Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
-         WorkFree=True, Expandable=True,
+ Unf=Unf{Src=<vanilla>, TopLvl=True,
+         Value=True, ConLike=True, WorkFree=True, Expandable=True,
          Guidance=ALWAYS_IF(arity=0,unsat_ok=True,boring_ok=True)}]
 one = M.one1
 
diff --git a/testsuite/tests/numeric/should_compile/T7116.stdout b/testsuite/tests/numeric/should_compile/T7116.stdout
index 407a057855..afcf45932e 100644
--- a/testsuite/tests/numeric/should_compile/T7116.stdout
+++ b/testsuite/tests/numeric/should_compile/T7116.stdout
@@ -6,36 +6,41 @@ Result size of Tidy Core
 -- RHS size: {terms: 1, types: 0, coercions: 0, joins: 0/0}
 T7116.$trModule4 :: GHC.Prim.Addr#
 [GblId,
- Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
-         WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 20 0}]
+ Unf=Unf{Src=<vanilla>, TopLvl=True,
+         Value=True, ConLike=True, WorkFree=True, Expandable=True,
+         Guidance=IF_ARGS [] 20 0}]
 T7116.$trModule4 = "main"#
 
 -- RHS size: {terms: 2, types: 0, coercions: 0, joins: 0/0}
 T7116.$trModule3 :: GHC.Types.TrName
 [GblId,
- Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
-         WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 10 10}]
+ Unf=Unf{Src=<vanilla>, TopLvl=True,
+         Value=True, ConLike=True, WorkFree=True, Expandable=True,
+         Guidance=IF_ARGS [] 10 10}]
 T7116.$trModule3 = GHC.Types.TrNameS T7116.$trModule4
 
 -- RHS size: {terms: 1, types: 0, coercions: 0, joins: 0/0}
 T7116.$trModule2 :: GHC.Prim.Addr#
 [GblId,
- Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
-         WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 30 0}]
+ Unf=Unf{Src=<vanilla>, TopLvl=True,
+         Value=True, ConLike=True, WorkFree=True, Expandable=True,
+         Guidance=IF_ARGS [] 30 0}]
 T7116.$trModule2 = "T7116"#
 
 -- RHS size: {terms: 2, types: 0, coercions: 0, joins: 0/0}
 T7116.$trModule1 :: GHC.Types.TrName
 [GblId,
- Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
-         WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 10 10}]
+ Unf=Unf{Src=<vanilla>, TopLvl=True,
+         Value=True, ConLike=True, WorkFree=True, Expandable=True,
+         Guidance=IF_ARGS [] 10 10}]
 T7116.$trModule1 = GHC.Types.TrNameS T7116.$trModule2
 
 -- RHS size: {terms: 3, types: 0, coercions: 0, joins: 0/0}
 T7116.$trModule :: GHC.Types.Module
 [GblId,
- Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
-         WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 10 10}]
+ Unf=Unf{Src=<vanilla>, TopLvl=True,
+         Value=True, ConLike=True, WorkFree=True, Expandable=True,
+         Guidance=IF_ARGS [] 10 10}]
 T7116.$trModule
   = GHC.Types.Module T7116.$trModule3 T7116.$trModule1
 
@@ -45,8 +50,8 @@ dr :: Double -> Double
  Arity=1,
  Str=<1!P(L)>,
  Cpr=1,
- Unf=Unf{Src=StableSystem, TopLvl=True, Value=True, ConLike=True,
-         WorkFree=True, Expandable=True,
+ Unf=Unf{Src=StableSystem, TopLvl=True,
+         Value=True, ConLike=True, WorkFree=True, Expandable=True,
          Guidance=ALWAYS_IF(arity=1,unsat_ok=True,boring_ok=False)
          Tmpl= \ (x [Occ=Once1!] :: Double) ->
                  case x of { GHC.Types.D# x1 ->
@@ -62,8 +67,8 @@ dl :: Double -> Double
  Arity=1,
  Str=<1!P(L)>,
  Cpr=1,
- Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
-         WorkFree=True, Expandable=True,
+ Unf=Unf{Src=<vanilla>, TopLvl=True,
+         Value=True, ConLike=True, WorkFree=True, Expandable=True,
          Guidance=ALWAYS_IF(arity=0,unsat_ok=True,boring_ok=True)}]
 dl = dr
 
@@ -73,8 +78,8 @@ fr :: Float -> Float
  Arity=1,
  Str=<1!P(L)>,
  Cpr=1,
- Unf=Unf{Src=StableSystem, TopLvl=True, Value=True, ConLike=True,
-         WorkFree=True, Expandable=True,
+ Unf=Unf{Src=StableSystem, TopLvl=True,
+         Value=True, ConLike=True, WorkFree=True, Expandable=True,
          Guidance=ALWAYS_IF(arity=1,unsat_ok=True,boring_ok=False)
          Tmpl= \ (x [Occ=Once1!] :: Float) ->
                  case x of { GHC.Types.F# x1 ->
@@ -92,8 +97,8 @@ fl :: Float -> Float
  Arity=1,
  Str=<1!P(L)>,
  Cpr=1,
- Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
-         WorkFree=True, Expandable=True,
+ Unf=Unf{Src=<vanilla>, TopLvl=True,
+         Value=True, ConLike=True, WorkFree=True, Expandable=True,
          Guidance=ALWAYS_IF(arity=0,unsat_ok=True,boring_ok=True)}]
 fl = fr
 
diff --git a/testsuite/tests/simplCore/should_compile/T22272.hs b/testsuite/tests/simplCore/should_compile/T22272.hs
new file mode 100644
index 0000000000..dfcc5a0567
--- /dev/null
+++ b/testsuite/tests/simplCore/should_compile/T22272.hs
@@ -0,0 +1,7 @@
+{-# LANGUAGE NoImplicitPrelude #-}
+module T22272 where
+
+import T22272_A
+
+bar :: ()
+bar = foo
diff --git a/testsuite/tests/simplCore/should_compile/T22272.stderr b/testsuite/tests/simplCore/should_compile/T22272.stderr
new file mode 100644
index 0000000000..80ba25439d
--- /dev/null
+++ b/testsuite/tests/simplCore/should_compile/T22272.stderr
@@ -0,0 +1,2 @@
+[1 of 2] Compiling T22272_A         ( T22272_A.hs, T22272_A.o )
+[2 of 2] Compiling T22272           ( T22272.hs, T22272.o )
diff --git a/testsuite/tests/simplCore/should_compile/T22272_A.hs b/testsuite/tests/simplCore/should_compile/T22272_A.hs
new file mode 100644
index 0000000000..d84750d2f6
--- /dev/null
+++ b/testsuite/tests/simplCore/should_compile/T22272_A.hs
@@ -0,0 +1,5 @@
+{-# LANGUAGE NoImplicitPrelude #-}
+module T22272_A where
+
+foo :: ()
+foo = foo
diff --git a/testsuite/tests/simplCore/should_compile/T3772.stdout b/testsuite/tests/simplCore/should_compile/T3772.stdout
index 6faaab181a..43847f89e5 100644
--- a/testsuite/tests/simplCore/should_compile/T3772.stdout
+++ b/testsuite/tests/simplCore/should_compile/T3772.stdout
@@ -6,36 +6,41 @@ Result size of Tidy Core
 -- RHS size: {terms: 1, types: 0, coercions: 0, joins: 0/0}
 T3772.$trModule4 :: GHC.Prim.Addr#
 [GblId,
- Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
-         WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 20 0}]
+ Unf=Unf{Src=<vanilla>, TopLvl=True,
+         Value=True, ConLike=True, WorkFree=True, Expandable=True,
+         Guidance=IF_ARGS [] 20 0}]
 T3772.$trModule4 = "main"#
 
 -- RHS size: {terms: 2, types: 0, coercions: 0, joins: 0/0}
 T3772.$trModule3 :: GHC.Types.TrName
 [GblId,
- Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
-         WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 10 10}]
+ Unf=Unf{Src=<vanilla>, TopLvl=True,
+         Value=True, ConLike=True, WorkFree=True, Expandable=True,
+         Guidance=IF_ARGS [] 10 10}]
 T3772.$trModule3 = GHC.Types.TrNameS T3772.$trModule4
 
 -- RHS size: {terms: 1, types: 0, coercions: 0, joins: 0/0}
 T3772.$trModule2 :: GHC.Prim.Addr#
 [GblId,
- Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
-         WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 30 0}]
+ Unf=Unf{Src=<vanilla>, TopLvl=True,
+         Value=True, ConLike=True, WorkFree=True, Expandable=True,
+         Guidance=IF_ARGS [] 30 0}]
 T3772.$trModule2 = "T3772"#
 
 -- RHS size: {terms: 2, types: 0, coercions: 0, joins: 0/0}
 T3772.$trModule1 :: GHC.Types.TrName
 [GblId,
- Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
-         WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 10 10}]
+ Unf=Unf{Src=<vanilla>, TopLvl=True,
+         Value=True, ConLike=True, WorkFree=True, Expandable=True,
+         Guidance=IF_ARGS [] 10 10}]
 T3772.$trModule1 = GHC.Types.TrNameS T3772.$trModule2
 
 -- RHS size: {terms: 3, types: 0, coercions: 0, joins: 0/0}
 T3772.$trModule :: GHC.Types.Module
 [GblId,
- Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True,
-         WorkFree=True, Expandable=True, Guidance=IF_ARGS [] 10 10}]
+ Unf=Unf{Src=<vanilla>, TopLvl=True,
+         Value=True, ConLike=True, WorkFree=True, Expandable=True,
+         Guidance=IF_ARGS [] 10 10}]
 T3772.$trModule
   = GHC.Types.Module T3772.$trModule3 T3772.$trModule1
 
@@ -67,8 +72,8 @@ foo [InlPrag=NOINLINE[final]] :: Int -> ()
  Arity=1,
  Str=<1!P(L)>,
  Cpr=1,
- Unf=Unf{Src=StableSystem, TopLvl=True, Value=True, ConLike=True,
-         WorkFree=True, Expandable=True,
+ Unf=Unf{Src=StableSystem, TopLvl=True,
+         Value=True, ConLike=True, WorkFree=True, Expandable=True,
          Guidance=ALWAYS_IF(arity=1,unsat_ok=True,boring_ok=False)
          Tmpl= \ (n [Occ=Once1!] :: Int) ->
                  case n of { GHC.Types.I# ww [Occ=Once1] ->
diff --git a/testsuite/tests/simplCore/should_compile/all.T b/testsuite/tests/simplCore/should_compile/all.T
index 46bf60e1ae..5209c0c7cb 100644
--- a/testsuite/tests/simplCore/should_compile/all.T
+++ b/testsuite/tests/simplCore/should_compile/all.T
@@ -457,3 +457,4 @@ test('T22317', [grep_errmsg(r'ANSWER = YES') ], compile, ['-O -dinline-check m -
 test('T22494', [grep_errmsg(r'case') ], compile, ['-O -ddump-simpl -dsuppress-uniques'])
 test('T22491', normal, compile, ['-O2'])
 test('T21476', normal, compile, [''])
+test('T22272', normal, multimod_compile, ['T22272', '-O -fexpose-all-unfoldings -fno-omit-interface-pragmas -fno-ignore-interface-pragmas'])