[commit: ghc] master: MkIface: Introduce PatSynId, ReflectionId, DefMethId (f6035bc)

[git at git.haskell.org]

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

On branch  : master
Link       : http://ghc.haskell.org/trac/ghc/changeset/f6035bc004fd004e421355bb88ec1e601c3c0c0c/ghc

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

commit f6035bc004fd004e421355bb88ec1e601c3c0c0c
Author: Ben Gamari <ben at smart-cactus.org>
Date:   Wed Aug 26 18:14:31 2015 +0200

    MkIface: Introduce PatSynId, ReflectionId, DefMethId
    
    Currently we don't persist these three "advisory" IdInfos through
    interface files.  We easily could if needed.


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

f6035bc004fd004e421355bb88ec1e601c3c0c0c
 compiler/basicTypes/IdInfo.hs | 19 ++++++++++++++++++-
 compiler/iface/MkIface.hs     | 13 +++++++++++--
 2 files changed, 29 insertions(+), 3 deletions(-)

diff --git a/compiler/basicTypes/IdInfo.hs b/compiler/basicTypes/IdInfo.hs
index e9fccbe..0291005 100644
--- a/compiler/basicTypes/IdInfo.hs
+++ b/compiler/basicTypes/IdInfo.hs
@@ -122,7 +122,8 @@ data IdDetails
                                 --  b) when desugaring a RecordCon we can get
                                 --     from the Id back to the data con]
 
-  | ClassOpId Class             -- ^ The 'Id' is a superclass selector or class operation of a class
+  | ClassOpId Class             -- ^ The 'Id' is a superclass selector,
+                                -- or class operation of a class
 
   | PrimOpId PrimOp             -- ^ The 'Id' is for a primitive operator
   | FCallId ForeignCall         -- ^ The 'Id' is for a foreign call
@@ -134,6 +135,19 @@ data IdDetails
        --                  implemented with a newtype, so it might be bad
        --                  to be strict on this dictionary
 
+  -- The rest are distinguished only for debugging reasons
+  -- e.g. to suppress them in -ddump-types
+  -- Currently we don't persist these through interface file
+  -- (see MkIface.toIfaceIdDetails), but we easily could if it mattered
+
+  | DefMethId                   -- ^ A default-method Id, either polymorphic or generic
+
+  | ReflectionId                -- ^ A top-level Id to support runtime reflection
+                                -- e.g. $trModule, or $tcT
+
+  | PatSynId                    -- ^ A top-level Id to support pattern synonyms;
+                                -- the builder or matcher for the patern synonym
+
 coVarDetails :: IdDetails
 coVarDetails = VanillaId
 
@@ -145,6 +159,9 @@ pprIdDetails VanillaId = empty
 pprIdDetails other     = brackets (pp other)
  where
    pp VanillaId         = panic "pprIdDetails"
+   pp DefMethId         = ptext (sLit "DefMethId")
+   pp ReflectionId      = ptext (sLit "ReflectionId")
+   pp PatSynId          = ptext (sLit "PatSynId")
    pp (DataConWorkId _) = ptext (sLit "DataCon")
    pp (DataConWrapId _) = ptext (sLit "DataConWrapper")
    pp (ClassOpId {})    = ptext (sLit "ClassOp")
diff --git a/compiler/iface/MkIface.hs b/compiler/iface/MkIface.hs
index 714777a..697972a 100644
--- a/compiler/iface/MkIface.hs
+++ b/compiler/iface/MkIface.hs
@@ -1875,8 +1875,17 @@ toIfaceIdDetails VanillaId                      = IfVanillaId
 toIfaceIdDetails (DFunId {})                    = IfDFunId
 toIfaceIdDetails (RecSelId { sel_naughty = n
                            , sel_tycon = tc })  = IfRecSelId (toIfaceTyCon tc) n
-toIfaceIdDetails other                          = pprTrace "toIfaceIdDetails" (ppr other)
-                                                  IfVanillaId   -- Unexpected
+
+  -- Currently we don't persist these three "advisory" IdInfos
+  -- through interface files.  We easily could if it mattered
+toIfaceIdDetails PatSynId     = IfVanillaId
+toIfaceIdDetails ReflectionId = IfVanillaId
+toIfaceIdDetails DefMethId    = IfVanillaId
+
+  -- The remaining cases are all "implicit Ids" which don't
+  -- appear in interface files at all
+toIfaceIdDetails other = pprTrace "toIfaceIdDetails" (ppr other)
+                         IfVanillaId   -- Unexpected; the other
 
 toIfaceIdInfo :: IdInfo -> IfaceIdInfo
 toIfaceIdInfo id_info