Add regression test for #12790

Test Plan: make test TEST=T12790

Reviewers: bgamari, mpickering

Reviewed By: mpickering

Subscribers: mpickering, dfeuer, rwbarton, thomie, carter

GHC Trac Issues: #12790

Differential Revision: https://phabricator.haskell.org/D4412

2 files changed, 49 insertions, 0 deletions

diff --git a/testsuite/tests/profiling/should_compile/T12790.hs b/testsuite/tests/profiling/should_compile/T12790.hs
new file mode 100644
index 0000000000..3c3f7d487e
--- /dev/null
+++ b/testsuite/tests/profiling/should_compile/T12790.hs
@@ -0,0 +1,48 @@
+module T12790 (list) where
+
+import Data.Foldable (asum)
+import Text.ParserCombinators.Parsec (Parser, sepBy, try)
+
+data Expr
+  = Var Fixity String
+  | App Expr Expr
+
+data Fixity = Pref | Inf
+
+cons, nil :: Expr
+cons = Var Inf  ":"
+nil  = Var Pref "[]"
+
+brackets :: Parser a -> Parser a
+brackets = undefined
+
+symbol :: String -> Parser String
+symbol = undefined
+
+list :: Parser Expr
+list = asum (map (try . brackets) plist) where
+  plist = [
+    foldr (\e1 e2 -> cons `App` e1 `App` e2) nil `fmap`
+      (myParser False `sepBy` symbol ","),
+    do e <- myParser False
+       _ <- symbol ".."
+       return $ Var Pref "enumFrom" `App` e,
+    do e  <- myParser False
+       _  <- symbol ","
+       e' <- myParser False
+       _  <- symbol ".."
+       return $ Var Pref "enumFromThen" `App` e `App` e',
+    do e  <- myParser False
+       _  <- symbol ".."
+       e' <- myParser False
+       return $ Var Pref "enumFromTo" `App` e `App` e',
+    do e   <- myParser False
+       _   <- symbol ","
+       e'  <- myParser False
+       _   <- symbol ".."
+       e'' <- myParser False
+       return $ Var Pref "enumFromThenTo" `App` e `App` e' `App` e''
+    ]
+
+myParser :: Bool -> Parser Expr
+myParser = undefined
diff --git a/testsuite/tests/profiling/should_compile/all.T b/testsuite/tests/profiling/should_compile/all.T
index 155206ab7b..1ebcb07be4 100644
--- a/testsuite/tests/profiling/should_compile/all.T
+++ b/testsuite/tests/profiling/should_compile/all.T
@@ -5,3 +5,4 @@ test('prof002', [only_ways(['normal']), req_profiling], compile_and_run, ['-prof
 
 test('T2410', [only_ways(['normal']), req_profiling], compile, ['-O2 -prof -fprof-cafs'])
 test('T5889', [only_ways(['normal']), req_profiling, extra_files(['T5889/A.hs', 'T5889/B.hs'])], multimod_compile, ['A B', '-O -prof -fno-prof-count-entries -v0'])
+test('T12790', [only_ways(['normal']), req_profiling], compile, ['-O -prof'])