Add warning for probable identities (fromIntegral and friends)

[ghc-hetmet.git] / compiler / main / DynFlags.hs

diff --git a/compiler/main/DynFlags.hs b/compiler/main/DynFlags.hs
index 8f0faec..513c97f 100644 (file)
--- a/compiler/main/DynFlags.hs
+++ b/compiler/main/DynFlags.hs
@@ -199,6 +199,7 @@ data DynFlag
    | Opt_WarnDodgyImports
    | Opt_WarnOrphans
    | Opt_WarnAutoOrphans
+   | Opt_WarnIdentities
    | Opt_WarnTabs
    | Opt_WarnUnrecognisedPragmas
    | Opt_WarnDodgyForeignImports
@@ -223,7 +224,7 @@ data DynFlag
    | Opt_DoEtaReduction
    | Opt_CaseMerge
    | Opt_UnboxStrictFields
-   | Opt_MethodSharing
+   | Opt_MethodSharing -- Now a no-op; remove in GHC 7.2
    | Opt_DictsCheap
    | Opt_EnableRewriteRules            -- Apply rewrite rules during simplification
    | Opt_Vectorise
@@ -1422,6 +1423,7 @@ fFlags = [
   ( "warn-deprecations",                Opt_WarnWarningsDeprecations, nop ),
   ( "warn-deprecated-flags",            Opt_WarnDeprecatedFlags, nop ),
   ( "warn-orphans",                     Opt_WarnOrphans, nop ),
+  ( "warn-identities",                  Opt_WarnIdentities, nop ),
   ( "warn-auto-orphans",                Opt_WarnAutoOrphans, nop ),
   ( "warn-tabs",                        Opt_WarnTabs, nop ),
   ( "warn-unrecognised-pragmas",        Opt_WarnUnrecognisedPragmas, nop ),
@@ -1446,7 +1448,9 @@ fFlags = [
   ( "do-eta-reduction",                 Opt_DoEtaReduction, nop ),
   ( "case-merge",                       Opt_CaseMerge, nop ),
   ( "unbox-strict-fields",              Opt_UnboxStrictFields, nop ),
-  ( "method-sharing",                   Opt_MethodSharing, nop ),
+  ( "method-sharing",                   Opt_MethodSharing, 
+     \_ -> deprecate "doesn't do anything any more"),
+     -- Remove altogether in GHC 7.2
   ( "dicts-cheap",                      Opt_DictsCheap, nop ),
   ( "excess-precision",                 Opt_ExcessPrecision, nop ),
   ( "eager-blackholing",                Opt_EagerBlackHoling, nop ),
@@ -1618,8 +1622,6 @@ defaultFlags
   = [ Opt_AutoLinkPackages,
       Opt_ReadUserPackageConf,
 
-      Opt_MethodSharing,
-
       Opt_DoAsmMangling,
 
       Opt_SharedImplib,
@@ -1735,7 +1737,8 @@ minusWallOpts
         Opt_WarnMissingSigs,
         Opt_WarnHiShadows,
         Opt_WarnOrphans,
-        Opt_WarnUnusedDoBind
+        Opt_WarnUnusedDoBind,
+        Opt_WarnIdentities
       ]
 
 -- minuswRemovesOpts should be every warning option
@@ -1969,7 +1972,6 @@ setDPHOpt dflags = setOptLevel 2 (dflags { maxSimplIterations  = 20
                                          , specConstrCount     = Nothing
                                          })
                    `dopt_set`   Opt_DictsCheap
-                   `dopt_unset` Opt_MethodSharing
 
 data DPHBackend = DPHPar
                 | DPHSeq