From 431c4b6e37e414b6959cdf14a50622c514ea0a85 Mon Sep 17 00:00:00 2001
From: Luke Lau <luke_lau@icloud.com>
Date: Sun, 2 Jun 2019 17:39:47 +0100
Subject: [PATCH] Detect and remove __anon_exprs in repl

You might have noticed that when entering in top-level expressions you
end up getting duplicate __anon_expr.1, __anon_expr.2s etc. Since we
don't want these anonymous functions to stick around, in this commit
we're detecting them and then removing them once we're done.

We also only want to run the JIT whenever the user has entered a
top-level expression, so we've also sketched that out.
---
 Main.hs  | 14 ++++++++++++--
 Utils.hs |  8 ++++++++
 2 files changed, 20 insertions(+), 2 deletions(-)

diff --git a/Main.hs b/Main.hs
index ee8ee60..4dafa02 100644
--- a/Main.hs
+++ b/Main.hs
@@ -2,6 +2,7 @@
 
 import AST as K -- K for Kaleidoscope
 import Utils
+import Control.Monad
 import Control.Monad.Trans.Class
 import Control.Monad.Trans.Reader
 import Control.Monad.IO.Class
@@ -40,21 +41,30 @@ repl = do
       case readMaybe l of
         Nothing ->  liftIO $ hPutStrLn stderr "Couldn't parse"
         Just ast -> do
-          hoist $ buildAST ast
-          mostRecentDef >>= liftIO . Text.hPutStrLn stderr . ppll
+          anon <- isAnonExpr <$> hoist (buildAST ast)
+          def <- mostRecentDef
           
           ast <- moduleSoFar "main"
           ctx <- lift ask
           liftIO $ withModuleFromAST ctx ast $ \mdl -> do
+            Text.hPutStrLn stderr $ ppll def
             let spec = defaultCuratedPassSetSpec { optLevel = Just 3 }
             -- this returns true if the module was modified
             withPassManager spec $ flip runPassManager mdl
             Text.hPutStrLn stderr . ("\n" <>) . ppllvm =<< moduleAST mdl
+            when anon (jit mdl >>= hPrint stderr)
+
+          when anon (removeDef def)
       repl
   where
     eofHandler e
       | isEOFError e = return Nothing
       | otherwise = ioError e
+    isAnonExpr (ConstantOperand (GlobalReference _ "__anon_expr")) = True
+    isAnonExpr _ = False
+
+jit :: Module -> IO Double
+jit _mdl = putStrLn "Working on it!" >> return 0
 
 type Binds = Map.Map String Operand
 
diff --git a/Utils.hs b/Utils.hs
index 3bd3b37..cd325a4 100644
--- a/Utils.hs
+++ b/Utils.hs
@@ -6,6 +6,7 @@ module Utils where
 import Control.Monad.Trans.State
 import Data.ByteString.Short (ShortByteString)
 import Data.Functor.Identity
+import Data.List
 import LLVM.AST
 import LLVM.IRBuilder.Module
 import LLVM.IRBuilder.Internal.SnocList
@@ -16,6 +17,13 @@ moduleSoFar nm = do
   let ds = getSnocList (builderDefs s)
   return $ defaultModule { moduleName = nm, moduleDefinitions = ds }
 
+removeDef :: MonadModuleBuilder m => Definition -> m ()
+removeDef def = liftModuleState (modify update)
+  where
+    update (ModuleBuilderState defs typeDefs) =
+      let newDefs = SnocList (delete def (getSnocList defs))
+      in ModuleBuilderState newDefs typeDefs
+
 mostRecentDef :: Monad m => ModuleBuilderT m Definition
 mostRecentDef = last . getSnocList . builderDefs <$> liftModuleState get
 
-- 
2.30.2