Add HasCallStack to internalError (purescript#2608)

alexbiehl · paf31 · commit 6277f6925841 · 2017-01-30T08:35:24.000-08:00
* Add HasCallStack to internalError

* Update CONTRIBUTORS.md

* Update CONTRIBUTORS.md

* Update CONTRIBUTORS.md
diff --git a/CONTRIBUTORS.md b/CONTRIBUTORS.md
@@ -89,6 +89,7 @@ This file lists the contributors to the PureScript compiler project, and the ter
 - [@RyanGlScott](https://github.com/RyanGlScott) (Ryan Scott) My existing contributions and all future contributions until further notice are Copyright Ryan Scott, and are licensed to the owners and users of the PureScript compiler project under the terms of the [MIT license](http://opensource.org/licenses/MIT).
 - [@seungha-kim](https://github.com/seungha-kim) (Seungha Kim) My existing contributions and all future contributions until further notice are Copyright Seungha Kim, and are licensed to the owners and users of the PureScript compiler project under the terms of the [MIT license](http://opensource.org/licenses/MIT).
 - [@matthewleon](https://github.com/matthewleon) (Matthew Leon) My existing contributions and all future contributions until further notice are Copyright Matthew Leon, and are licensed to the owners and users of the PureScript compiler project under the terms of the [MIT license](http://opensource.org/licenses/MIT).
+- [@alexbiehl](https://github.com/alexbiehl) (Alexander Biehl) My existing contributions and all future contributions until further notice are Copyright Alexander Biehl, and are licensed to the owners and users of the PureScript compiler project under the terms of the [MIT license](http://opensource.org/licenses/MIT).
 
 ### Companies
 
diff --git a/src/Language/PureScript/Crash.hs b/src/Language/PureScript/Crash.hs
@@ -1,11 +1,27 @@
-module Language.PureScript.Crash where
-
-import Prelude.Compat
-
--- | Exit with an error message and a crash report link.
-internalError :: String -> a
-internalError =
-  error
-  . ("An internal error occurred during compilation: " ++)
-  . (++ "\nPlease report this at https://github.com/purescript/purescript/issues")
-  . show
+{-# LANGUAGE CPP #-}
+{-# LANGUAGE ImplicitParams #-}
+
+module Language.PureScript.Crash where
+
+import Prelude.Compat
+
+import qualified GHC.Stack
+
+-- | A compatibility wrapper for the @GHC.Stack.HasCallStack@ constraint.
+#if __GLASGOW_HASKELL__ >= 800
+type HasCallStack = GHC.Stack.HasCallStack
+#elif MIN_VERSION_GLASGOW_HASKELL(7,10,2,0)
+type HasCallStack = (?callStack :: GHC.Stack.CallStack)
+#else
+import GHC.Exts (Constraint)
+-- CallStack wasn't present in GHC 7.10.1
+type HasCallStack = (() :: Constraint)
+#endif
+
+-- | Exit with an error message and a crash report link.
+internalError :: HasCallStack => String -> a
+internalError =
+  error
+  . ("An internal error occurred during compilation: " ++)
+  . (++ "\nPlease report this at https://github.com/purescript/purescript/issues")
+  . show
