Add support for StaticPointers in GHCi

Here we add support to GHCi for StaticPointers. This process begins by
adding remote GHCi messages for adding entries to the static pointer
table. We then collect binders needing SPT entries after linking and
send the interpreter a message adding entries with the appropriate
fingerprints.

Test Plan: `make test TEST=StaticPtr`

Reviewers: facundominguez, mboes, simonpj, simonmar, goldfire, austin,
hvr, erikd

Reviewed By: simonpj, simonmar

Subscribers: RyanGlScott, simonpj, thomie

Differential Revision: https://phabricator.haskell.org/D2504

GHC Trac Issues: #12356

1 files changed, 15 insertions, 2 deletions

diff --git a/compiler/main/GHC.hs b/compiler/main/GHC.hs
index 25c1484770..bc406d5c59 100644
--- a/compiler/main/GHC.hs
+++ b/compiler/main/GHC.hs
@@ -323,7 +323,7 @@ import Annotations
 import Module
 import Panic
 import Platform
-import Bag              ( unitBag )
+import Bag              ( listToBag, unitBag )
 import ErrUtils
 import MonadUtils
 import Util
@@ -615,7 +615,8 @@ getProgramDynFlags = getSessionDynFlags
 setInteractiveDynFlags :: GhcMonad m => DynFlags -> m ()
 setInteractiveDynFlags dflags = do
   dflags' <- checkNewDynFlags dflags
-  modifySession $ \h -> h{ hsc_IC = (hsc_IC h) { ic_dflags = dflags' }}
+  dflags'' <- checkNewInteractiveDynFlags dflags'
+  modifySession $ \h -> h{ hsc_IC = (hsc_IC h) { ic_dflags = dflags'' }}
 
 -- | Get the 'DynFlags' used to evaluate interactive expressions.
 getInteractiveDynFlags :: GhcMonad m => m DynFlags
@@ -637,6 +638,18 @@ checkNewDynFlags dflags = do
   liftIO $ handleFlagWarnings dflags warnings
   return dflags'
 
+checkNewInteractiveDynFlags :: MonadIO m => DynFlags -> m DynFlags
+checkNewInteractiveDynFlags dflags0 = do
+  dflags1 <-
+      if xopt LangExt.StaticPointers dflags0
+      then do liftIO $ printOrThrowWarnings dflags0 $ listToBag
+                [mkPlainWarnMsg dflags0 interactiveSrcSpan
+                 $ text "StaticPointers is not supported in GHCi interactive expressions."]
+              return $ xopt_unset dflags0 LangExt.StaticPointers
+      else return dflags0
+  return dflags1
+
+
 -- %************************************************************************
 -- %*                                                                      *
 --             Setting, getting, and modifying the targets