[commit: ghc] wip/T14068: Mark `eqString` as `NOINLINE` (8d7a23a)

[git at git.haskell.org]

Repository : ssh://git@git.haskell.org/ghc

On branch  : wip/T14068
Link       : http://ghc.haskell.org/trac/ghc/changeset/8d7a23a8b297a0eeac2a9754561c52bae4733d9a/ghc

>---------------------------------------------------------------

commit 8d7a23a8b297a0eeac2a9754561c52bae4733d9a
Author: Joachim Breitner <mail at joachim-breitner.de>
Date:   Wed Aug 2 10:53:37 2017 -0400

    Mark `eqString` as `NOINLINE`
    
    so that the built-in rule can still match.
    
    This will be a problem in general: With loopification, recursive
    functions can now inline (yay!) but many people out there probably rely
    on the fact that recursive functions cannot inline (ouch). Hopefully the
    recent warnings in GHC made them fix this before loopification reaches
    them.


>---------------------------------------------------------------

8d7a23a8b297a0eeac2a9754561c52bae4733d9a
 libraries/base/GHC/Base.hs | 1 +
 1 file changed, 1 insertion(+)

diff --git a/libraries/base/GHC/Base.hs b/libraries/base/GHC/Base.hs
index 052f13f..0ff4589 100644
--- a/libraries/base/GHC/Base.hs
+++ b/libraries/base/GHC/Base.hs
@@ -1183,6 +1183,7 @@ eqString :: String -> String -> Bool
 eqString []       []       = True
 eqString (c1:cs1) (c2:cs2) = c1 == c2 && cs1 `eqString` cs2
 eqString _        _        = False
+{-# NOINLINE eqString #-}
 
 {-# RULES "eqString" (==) = eqString #-}
 -- eqString also has a BuiltInRule in PrelRules.hs: