From 7609dfc63e021117c194544f83b2edce34a81520 Mon Sep 17 00:00:00 2001
From: Philip Herron <philip.herron@embecosm.com>
Date: Tue, 12 Apr 2022 13:20:14 +0100
Subject: Add missing unify rules for inference variables

Inference variables can unify with anything so this includes these
covariant types like references/slices etc. This patch is needed for more
complex type-checking in libcore and generics.
---
 gcc/rust/typecheck/rust-tyty-rules.h | 60 ++++++++++++++++++++++++++++++++++++
 1 file changed, 60 insertions(+)

(limited to 'gcc')

diff --git a/gcc/rust/typecheck/rust-tyty-rules.h b/gcc/rust/typecheck/rust-tyty-rules.h
index 7c50112..f95e7bf 100644
--- a/gcc/rust/typecheck/rust-tyty-rules.h
+++ b/gcc/rust/typecheck/rust-tyty-rules.h
@@ -867,6 +867,18 @@ public:
 		       TyVar (base_resolved->get_ref ()));
   }
 
+  void visit (InferType &type) override
+  {
+    if (type.get_infer_kind () != InferType::InferTypeKind::GENERAL)
+      {
+	BaseRules::visit (type);
+	return;
+      }
+
+    resolved = base->clone ();
+    resolved->set_ref (type.get_ref ());
+  }
+
 private:
   BaseType *get_base () override { return base; }
 
@@ -896,6 +908,18 @@ public:
 			      TyVar (base_resolved->get_ref ()));
   }
 
+  void visit (InferType &type) override
+  {
+    if (type.get_infer_kind () != InferType::InferTypeKind::GENERAL)
+      {
+	BaseRules::visit (type);
+	return;
+      }
+
+    resolved = base->clone ();
+    resolved->set_ref (type.get_ref ());
+  }
+
 private:
   BaseType *get_base () override { return base; }
 
@@ -1140,6 +1164,18 @@ public:
 				    type.get_ident ().locus, fields);
   }
 
+  void visit (InferType &type) override
+  {
+    if (type.get_infer_kind () != InferType::InferTypeKind::GENERAL)
+      {
+	BaseRules::visit (type);
+	return;
+      }
+
+    resolved = base->clone ();
+    resolved->set_ref (type.get_ref ());
+  }
+
 private:
   BaseType *get_base () override { return base; }
 
@@ -1263,6 +1299,18 @@ public:
 				  base->mutability ());
   }
 
+  void visit (InferType &type) override
+  {
+    if (type.get_infer_kind () != InferType::InferTypeKind::GENERAL)
+      {
+	BaseRules::visit (type);
+	return;
+      }
+
+    resolved = base->clone ();
+    resolved->set_ref (type.get_ref ());
+  }
+
 private:
   BaseType *get_base () override { return base; }
 
@@ -1303,6 +1351,18 @@ public:
 				base->mutability ());
   }
 
+  void visit (InferType &type) override
+  {
+    if (type.get_infer_kind () != InferType::InferTypeKind::GENERAL)
+      {
+	BaseRules::visit (type);
+	return;
+      }
+
+    resolved = base->clone ();
+    resolved->set_ref (type.get_ref ());
+  }
+
 private:
   BaseType *get_base () override { return base; }
 
-- 
cgit v1.1