From a78e986b294deb956bdac6bdf0ed476e31cbe902 Mon Sep 17 00:00:00 2001
From: Chris Penner <christopher.penner@gmail.com>
Date: Tue, 15 Oct 2024 11:48:57 -0700
Subject: [PATCH] Fix bad arg serialization

---
 unison-runtime/src/Unison/Runtime/ANF.hs             | 3 +++
 unison-runtime/src/Unison/Runtime/Decompile.hs       | 2 +-
 unison-runtime/src/Unison/Runtime/MCode.hs           | 3 +--
 unison-runtime/src/Unison/Runtime/MCode/Serialize.hs | 2 +-
 4 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/unison-runtime/src/Unison/Runtime/ANF.hs b/unison-runtime/src/Unison/Runtime/ANF.hs
index 48a91da074..61bd4ab662 100644
--- a/unison-runtime/src/Unison/Runtime/ANF.hs
+++ b/unison-runtime/src/Unison/Runtime/ANF.hs
@@ -1535,8 +1535,11 @@ type ANFD v = Compose (ANFM v) (Directed ())
 data GroupRef = GR Reference Word64
   deriving (Show)
 
+-- | A value which is either unboxed or boxed.
 type UBValue = Either Word64 Value
 
+-- | A list of either unboxed or boxed values.
+-- Each slot is one of unboxed or boxed but not both.
 type ValList = [UBValue]
 
 data Value
diff --git a/unison-runtime/src/Unison/Runtime/Decompile.hs b/unison-runtime/src/Unison/Runtime/Decompile.hs
index b78ef25ca2..564c08e16b 100644
--- a/unison-runtime/src/Unison/Runtime/Decompile.hs
+++ b/unison-runtime/src/Unison/Runtime/Decompile.hs
@@ -164,7 +164,6 @@ decompile backref topTerms = \case
     -- Only match lists of boxed args.
     | ([], bs) <- partitionEithers vs ->
         apps' (con rf ct) <$> traverse (decompile backref topTerms) bs
-  (DataC rf _ _) -> err (BadData rf) $ bug "<Data>"
   (PApV (CIx rf rt k) _ (partitionEithers -> ([], bs)))
     | rf == Builtin "jumpCont" ->
         err Cont $ bug "<Continuation>"
@@ -179,6 +178,7 @@ decompile backref topTerms = \case
     | otherwise -> err (UnkComb rf) $ ref () rf
   (PAp (CIx rf _ _) _ _) ->
     err (BadPAp rf) $ bug "<Unknown>"
+  (DataC rf _ _) -> err (BadData rf) $ bug "<Data>"
   BlackHole -> err Exn $ bug "<Exception>"
   (Captured {}) -> err Cont $ bug "<Continuation>"
   (Foreign f) ->
diff --git a/unison-runtime/src/Unison/Runtime/MCode.hs b/unison-runtime/src/Unison/Runtime/MCode.hs
index da31af90c5..265efd163d 100644
--- a/unison-runtime/src/Unison/Runtime/MCode.hs
+++ b/unison-runtime/src/Unison/Runtime/MCode.hs
@@ -267,8 +267,7 @@ data Args
   | VArg2 !Int !Int
   | VArgR !Int !Int
   | VArgN {-# UNPACK #-} !(PrimArray Int)
-  | -- TODO: What do I do with this?
-    VArgV !Int
+  | VArgV !Int
   deriving (Show, Eq, Ord)
 
 argsToLists :: Args -> [Int]
diff --git a/unison-runtime/src/Unison/Runtime/MCode/Serialize.hs b/unison-runtime/src/Unison/Runtime/MCode/Serialize.hs
index 32460a0c31..89930aefc3 100644
--- a/unison-runtime/src/Unison/Runtime/MCode/Serialize.hs
+++ b/unison-runtime/src/Unison/Runtime/MCode/Serialize.hs
@@ -264,7 +264,7 @@ instance Tag ArgsT where
 putArgs :: (MonadPut m) => Args -> m ()
 putArgs ZArgs = putTag ZArgsT
 putArgs (VArg1 i) = putTag Arg1T *> pInt i
-putArgs (VArg2 i j) = putTag Arg1T *> pInt i *> pInt j
+putArgs (VArg2 i j) = putTag Arg2T *> pInt i *> pInt j
 putArgs (VArgR i j) = putTag ArgRT *> pInt i *> pInt j
 putArgs (VArgN pa) = putTag ArgNT *> putIntArr pa
 putArgs (VArgV i) = putTag ArgVT *> pInt i