Tests for -XGeneralizedNewtypeDeriving

testsuite/tests/ghc-regress/parser/should_compile/all.T

@@ -62,3 +62,5 @@ test('read052', normal, compile, [''])
 test('read053', normal, compile, [''])
 test('read054', normal, compile, [''])
 test('read055', normal, compile, [''])
+test('read056', normal, compile, [''])
+test('read057', normal, compile, [''])

testsuite/tests/ghc-regress/parser/should_compile/read056.hs

+
+{-# OPTIONS_GHC -XGeneralizedNewtypeDeriving #-}
+
+module Foo where
+
+class C a
+instance C Int
+
+newtype Foo = Foo Int
+    deriving C
+

testsuite/tests/ghc-regress/parser/should_compile/read057.hs

+
+{-# LANGUAGE GeneralizedNewtypeDeriving #-}
+
+module Foo where
+
+class C a
+instance C Int
+
+newtype Foo = Foo Int
+    deriving C
+

testsuite/tests/ghc-regress/parser/should_fail/all.T

@@ -45,3 +45,4 @@ test('read035', normal, compile_fail, [''])
 test('read036', normal, compile_fail, [''])
 test('read037', normal, compile_fail, [''])
 test('read038', normal, compile_fail, [''])
+test('read039', normal, compile_fail, [''])

testsuite/tests/ghc-regress/parser/should_fail/read039.hs

+
+module Foo where
+
+class C a
+instance C Int
+
+newtype Foo = Foo Int
+    deriving C
+

testsuite/tests/ghc-regress/parser/should_fail/read039.stderr

+
+read039.hs:7:0:
+    Can't make a derived instance of `C Foo'
+      (`C' is not a derivable class
+       Try -fglasgow-exts for GHC's newtype-deriving extension)
+    In the newtype declaration for `Foo'