From d05f1ca86bff843baf26dc15b6ee9820c35d4b94 Mon Sep 17 00:00:00 2001
From: Markus Westerlind <marwes91@gmail.com>
Date: Tue, 29 Dec 2020 15:10:47 +0100
Subject: [PATCH] fix: Don't use the empty span in derive macros

---
 vm/src/derive/deserialize.rs |  1 +
 vm/src/derive/eq.rs          |  2 +-
 vm/src/derive/mod.rs         | 11 +++++++++--
 vm/src/derive/serialize.rs   |  9 ++++++++-
 vm/src/derive/show.rs        |  9 ++++++++-
 5 files changed, 27 insertions(+), 5 deletions(-)

diff --git a/vm/src/derive/deserialize.rs b/vm/src/derive/deserialize.rs
index cad7ec9d14..9395a8e6f5 100644
--- a/vm/src/derive/deserialize.rs
+++ b/vm/src/derive/deserialize.rs
@@ -153,6 +153,7 @@ pub fn generate<'ast>(
         typ: Some(binding_type(
             arena,
             symbols,
+            span,
             "Deserialize",
             self_type(),
             bind,
diff --git a/vm/src/derive/eq.rs b/vm/src/derive/eq.rs
index 24bb598b77..499061d8e1 100644
--- a/vm/src/derive/eq.rs
+++ b/vm/src/derive/eq.rs
@@ -220,7 +220,7 @@ pub fn generate<'ast>(
         args: &mut [],
         expr: pos::spanned(span, eq_record_expr),
         metadata: Default::default(),
-        typ: Some(binding_type(arena, symbols, "Eq", self_type(), bind)),
+        typ: Some(binding_type(arena, symbols, span, "Eq", self_type(), bind)),
         resolved_type: Type::hole(),
     })
 }
diff --git a/vm/src/derive/mod.rs b/vm/src/derive/mod.rs
index ef4fa12b6f..7283dcdcf3 100644
--- a/vm/src/derive/mod.rs
+++ b/vm/src/derive/mod.rs
@@ -286,13 +286,14 @@ fn is_self_type(self_: &Symbol, typ: &AstType<Symbol>) -> bool {
 fn binding_type<'ast>(
     arena: ast::ArenaRef<'_, 'ast, Symbol>,
     symbols: &mut Symbols,
+    span: Span<BytePos>,
     derive_type_name: &str,
     self_type: AstType<'ast, Symbol>,
     bind: &TypeBinding<'ast, Symbol>,
 ) -> AstType<'ast, Symbol> {
     let derive_symbol = symbols.simple_symbol(derive_type_name);
     let derive_type = move || arena.clone().ident(KindedIdent::new(derive_symbol.clone()));
-    arena.clone().function_implicit(
+    let mut typ = arena.clone().function_implicit(
         bind.alias.value.params().iter().cloned().map(|g| {
             TypeContext::app(
                 &mut arena.clone(),
@@ -305,5 +306,11 @@ fn binding_type<'ast>(
             derive_type(),
             arena.clone().alloc_extend(Some(self_type)),
         ),
-    )
+    );
+
+    crate::base::types::walk_type_mut(&mut typ, &mut |typ: &mut AstType<_>| {
+        *typ.span_mut() = span;
+    });
+
+    typ
 }
diff --git a/vm/src/derive/serialize.rs b/vm/src/derive/serialize.rs
index 7cd8d7dae1..23c150e47f 100644
--- a/vm/src/derive/serialize.rs
+++ b/vm/src/derive/serialize.rs
@@ -222,7 +222,14 @@ pub fn generate<'ast>(
         args: &mut [],
         expr: serializer_record_expr,
         metadata: Default::default(),
-        typ: Some(binding_type(arena, symbols, "Serialize", self_type(), bind)),
+        typ: Some(binding_type(
+            arena,
+            symbols,
+            span,
+            "Serialize",
+            self_type(),
+            bind,
+        )),
         resolved_type: Type::hole(),
     })
 }
diff --git a/vm/src/derive/show.rs b/vm/src/derive/show.rs
index 075adaf019..e3f83f41f0 100644
--- a/vm/src/derive/show.rs
+++ b/vm/src/derive/show.rs
@@ -204,7 +204,14 @@ pub fn generate<'ast>(
         args: &mut [],
         expr: pos::spanned(span, show_record_expr),
         metadata: Default::default(),
-        typ: Some(binding_type(arena, symbols, "Show", self_type(), bind)),
+        typ: Some(binding_type(
+            arena,
+            symbols,
+            span,
+            "Show",
+            self_type(),
+            bind,
+        )),
         resolved_type: Type::hole(),
     })
 }