1 files changed, 16 insertions, 1 deletions
diff --git a/compiler/utils/Panic.hs b/compiler/utils/Panic.hs
index 0a21f251fb..03f095b1a0 100644
--- a/compiler/utils/Panic.hs
+++ b/compiler/utils/Panic.hs
@@ -20,6 +20,8 @@ module Panic (
      panic, sorry, assertPanic, trace,
      panicDoc, sorryDoc, pgmErrorDoc,
 
+     cmdLineError, cmdLineErrorIO,
+
      Exception.Exception(..), showException, safeShowException,
      try, tryMost, throwTo,
 
@@ -27,6 +29,8 @@ module Panic (
 ) where
 #include "HsVersions.h"
 
+import GhcPrelude
+
 import {-# SOURCE #-} Outputable (SDoc, showSDocUnsafe)
 
 import Config
@@ -193,8 +197,19 @@ panicDoc    x doc = throwGhcException (PprPanic        x doc)
 sorryDoc    x doc = throwGhcException (PprSorry        x doc)
 pgmErrorDoc x doc = throwGhcException (PprProgramError x doc)
 
+cmdLineError :: String -> a
+cmdLineError = unsafeDupablePerformIO . cmdLineErrorIO
+
+cmdLineErrorIO :: String -> IO a
+cmdLineErrorIO x = do
+  stack <- ccsToStrings =<< getCurrentCCS x
+  if null stack
+    then throwGhcException (CmdLineError x)
+    else throwGhcException (CmdLineError (x ++ '\n' : renderStack stack))
+
+
 
--- | Throw an failed assertion exception for a given filename and line number.
+-- | Throw a failed assertion exception for a given filename and line number.
 assertPanic :: String -> Int -> a
 assertPanic file line =
   Exception.throw (Exception.AssertionFailed