Fix Trac #3259: expose 'lazy' only after generating interface files

[ghc-hetmet.git] / compiler / coreSyn / CorePrep.lhs

diff --git a/compiler/coreSyn/CorePrep.lhs b/compiler/coreSyn/CorePrep.lhs
index 3a6d037..89ec98f 100644 (file)
--- a/compiler/coreSyn/CorePrep.lhs
+++ b/compiler/coreSyn/CorePrep.lhs
@@ -11,6 +11,7 @@ module CorePrep (
 
 #include "HsVersions.h"
 
 
 #include "HsVersions.h"
 

+import PrelNames       ( lazyIdKey, hasKey )

 import CoreUtils
 import CoreArity
 import CoreFVs
 import CoreUtils
 import CoreArity
 import CoreFVs

@@ -89,6 +90,8 @@ The goal of this pass is to prepare for code generation.
     We want curried definitions for all of these in case they
     aren't inlined by some caller.
        
     We want curried definitions for all of these in case they
     aren't inlined by some caller.
        

+9.  Replace (lazy e) by e.  See Note [lazyId magic] in MkId.lhs
+

 This is all done modulo type applications and abstractions, so that
 when type erasure is done for conversion to STG, we don't end up with
 any trivial or useless bindings.
 This is all done modulo type applications and abstractions, so that
 when type erasure is done for conversion to STG, we don't end up with
 any trivial or useless bindings.

@@ -341,9 +344,14 @@ cpeRhsE :: CorePrepEnv -> CoreExpr -> UniqSM (Floats, CpeRhs)
 
 cpeRhsE _env expr@(Type _) = return (emptyFloats, expr)
 cpeRhsE _env expr@(Lit _)  = return (emptyFloats, expr)
 
 cpeRhsE _env expr@(Type _) = return (emptyFloats, expr)
 cpeRhsE _env expr@(Lit _)  = return (emptyFloats, expr)

-cpeRhsE env expr@(App {})  = cpeApp env expr

 cpeRhsE env expr@(Var {})  = cpeApp env expr
 
 cpeRhsE env expr@(Var {})  = cpeApp env expr
 

+cpeRhsE env (Var f `App` _ `App` arg)
+  | f `hasKey` lazyIdKey         -- Replace (lazy a) by a
+  = cpeRhsE env arg              -- See Note [lazyId magic] in MkId
+
+cpeRhsE env expr@(App {}) = cpeApp env expr
+

 cpeRhsE env (Let bind expr)
   = do { (env', new_binds) <- cpeBind NotTopLevel env bind
        ; (floats, body) <- cpeRhsE env' expr
 cpeRhsE env (Let bind expr)
   = do { (env', new_binds) <- cpeBind NotTopLevel env bind
        ; (floats, body) <- cpeRhsE env' expr

@@ -475,7 +483,7 @@ cpeApp env expr
 
     collect_args (App fun arg) depth
       = do { (fun',hd,fun_ty,floats,ss) <- collect_args fun (depth+1)
 
     collect_args (App fun arg) depth
       = do { (fun',hd,fun_ty,floats,ss) <- collect_args fun (depth+1)

-           ; let
+          ; let

               (ss1, ss_rest)   = case ss of
                                    (ss1:ss_rest) -> (ss1,     ss_rest)
                                    []            -> (lazyDmd, [])
               (ss1, ss_rest)   = case ss of
                                    (ss1:ss_rest) -> (ss1,     ss_rest)
                                    []            -> (lazyDmd, [])