From f867b78de193b1644ca46e33eea845b4aeb9ecf7 Mon Sep 17 00:00:00 2001
From: effectfully <effectfully@gmail.com>
Date: Wed, 25 Sep 2024 03:43:10 +0200
Subject: [PATCH 1/2] [Test] [Bug] Trigger the overpruned dependency bug

---
 .../Data/9.6/families/stakingCredential.pir.golden    |  0
 plutus-tx-plugin/test/Plugin/Data/Spec.hs             | 11 +++++++++++
 2 files changed, 11 insertions(+)
 create mode 100644 plutus-tx-plugin/test/Plugin/Data/9.6/families/stakingCredential.pir.golden

diff --git a/plutus-tx-plugin/test/Plugin/Data/9.6/families/stakingCredential.pir.golden b/plutus-tx-plugin/test/Plugin/Data/9.6/families/stakingCredential.pir.golden
new file mode 100644
index 00000000000..e69de29bb2d
diff --git a/plutus-tx-plugin/test/Plugin/Data/Spec.hs b/plutus-tx-plugin/test/Plugin/Data/Spec.hs
index 38af5ac7eb2..a473ce980b2 100644
--- a/plutus-tx-plugin/test/Plugin/Data/Spec.hs
+++ b/plutus-tx-plugin/test/Plugin/Data/Spec.hs
@@ -354,6 +354,7 @@ typeFamilies = testNested "families" [
     , goldenPir "associated" associated
     , goldenPir "associatedParam" associatedParam
     , goldenPir "basicData" basicData
+    , goldenPir "stakingCredential" stakingCredential
     , goldenUPlc "irreducible" irreducible
   ]
 
@@ -405,3 +406,13 @@ data instance BasicData Bool = Inst Integer
 
 basicData :: CompiledCode (BasicData Bool -> Integer)
 basicData = plc (Proxy @"basicData") (\(x :: BasicData Bool) -> let Inst i = x in i)
+
+data Credential
+  = PubKeyCredential
+data StakingCredential
+  = StakingHash Credential
+  | StakingPtr
+
+-- | Check that a data type used in an unused construtor of a used data type doesn't get eliminated.
+stakingCredential :: CompiledCode StakingCredential
+stakingCredential = plc (Proxy @"StakingCredential") StakingPtr

From 229b6903412086ed05b468a65e751fb59dd2fb08 Mon Sep 17 00:00:00 2001
From: effectfully <effectfully@gmail.com>
Date: Tue, 1 Oct 2024 00:53:15 +0200
Subject: [PATCH 2/2] Try not pruning data types

---
 .../src/PlutusIR/Analysis/Dependencies.hs     | 21 ++++---------------
 .../9.6/families/stakingCredential.pir.golden | 10 +++++++++
 2 files changed, 14 insertions(+), 17 deletions(-)

diff --git a/plutus-core/plutus-ir/src/PlutusIR/Analysis/Dependencies.hs b/plutus-core/plutus-ir/src/PlutusIR/Analysis/Dependencies.hs
index 1dd33024c7f..4c37e202df5 100644
--- a/plutus-core/plutus-ir/src/PlutusIR/Analysis/Dependencies.hs
+++ b/plutus-core/plutus-ir/src/PlutusIR/Analysis/Dependencies.hs
@@ -172,23 +172,10 @@ bindingDeps b = case b of
     vDeps <- tyVarDeclDeps d
     tvDeps <- traverse tyVarDeclDeps tvs
     cstrDeps <- traverse varDeclDeps constrs
-    -- Destructors depend on the datatype and the argument types of all the constructors,
-    -- because e.g. a destructor for Maybe looks like:
-    -- forall a . Maybe a -> (a -> r) -> r -> r
-    -- i.e. the argument type of the Just constructor appears as the argument to the branch.
-    --
-    -- We can get the effect of that by having it depend on all the constructor types
-    -- (which also include the datatype).
-    -- This is more diligent than currently necessary since we're going to make all the
-    -- term-level parts depend on each other later, but it's good practice and will be
-    -- useful if we ever stop doing that.
-    destrDeps <-
-      G.overlays
-        <$> (withCurrent destr $ traverse (typeDeps . _varDeclType) constrs)
-    let tus = fmap (view PLC.theUnique) (destr : fmap _varDeclName constrs)
-    -- See Note [Dependencies for datatype bindings, and pruning them]
-    let nonDatatypeClique = G.clique (fmap Variable tus)
-    pure $ G.overlays $ [vDeps] ++ tvDeps ++ cstrDeps ++ [destrDeps] ++ [nonDatatypeClique]
+    let tyus = fmap (view PLC.theUnique) $ _tyVarDeclName d : fmap _tyVarDeclName tvs
+    let tus = fmap (view PLC.theUnique) $ destr : fmap _varDeclName constrs
+    let localDeps = G.clique (fmap Variable $ tyus ++ tus)
+    pure $ G.overlays $ [vDeps] ++ tvDeps ++ cstrDeps ++ [localDeps]
 
 varDeclDeps ::
   ( DepGraph g
diff --git a/plutus-tx-plugin/test/Plugin/Data/9.6/families/stakingCredential.pir.golden b/plutus-tx-plugin/test/Plugin/Data/9.6/families/stakingCredential.pir.golden
index e69de29bb2d..07174201a4b 100644
--- a/plutus-tx-plugin/test/Plugin/Data/9.6/families/stakingCredential.pir.golden
+++ b/plutus-tx-plugin/test/Plugin/Data/9.6/families/stakingCredential.pir.golden
@@ -0,0 +1,10 @@
+program
+  1.1.0
+  (let
+    data Credential | Credential_match where
+      PubKeyCredential : Credential
+    data StakingCredential | StakingCredential_match where
+      StakingHash : Credential -> StakingCredential
+      StakingPtr : StakingCredential
+  in
+  StakingPtr)
\ No newline at end of file