wasmprinter: print the identifier that outer aliases refer to

crates/wasmprinter/src/component.rs

@@ -462,6 +462,24 @@ impl Printer<'_, '_> {
         Ok(&states[states.len() - count - 1])
     }
 
+    /// Prints the `count` of an outer alias as the identifier of the scope it
+    /// refers to, unless a scope in between has the same identifier, which
+    /// the identifier would refer to instead.
+    fn print_outer_count(&mut self, states: &[State], count: u32) -> Result<()> {
+        if let Some(i) = states.len().checked_sub(count as usize + 1) {
+            if let Some(name) = &states[i].name {
+                let shadowed = states[i + 1..]
+                    .iter()
+                    .any(|s| s.name.as_ref() == Some(name));
+                if !shadowed {
+                    return name.write_identifier(self);
+                }
+            }
+        }
+        write!(self.result, "{count}")?;
+        Ok(())
+    }
+
     pub(crate) fn print_outer_alias(
         &mut self,
         states: &mut [State],
@@ -479,11 +497,7 @@ impl Printer<'_, '_> {
             }
         };
         self.start_group("alias outer ")?;
-        if let Some(name) = outer.name.as_ref() {
-            name.write(self)?;
-        } else {
-            write!(self.result, "{count}")?;
-        }
+        self.print_outer_count(states, count)?;
         self.result.write_str(" ")?;
         match kind {
             OuterAliasKind::Type => {
@@ -1444,11 +1458,7 @@ impl Printer<'_, '_> {
                     }
                 };
                 self.start_group("alias outer ")?;
-                if let Some(name) = outer.name.as_ref() {
-                    name.write(self)?;
-                } else {
-                    write!(self.result, "{count}")?;
-                }
+                self.print_outer_count(states, count)?;
                 self.result.write_str(" ")?;
                 match kind {
                     ComponentOuterAliasKind::CoreModule => {

crates/wasmprinter/src/lib.rs

@@ -183,11 +183,13 @@ impl State {
     }
 }
 
+#[derive(Clone, PartialEq)]
 struct Naming {
     name: String,
     kind: NamingKind,
 }
 
+#[derive(Clone, PartialEq)]
 enum NamingKind {
     DollarName,
     DollarQuotedName,
@@ -533,6 +535,20 @@ impl Printer<'_, '_> {
                             name.write(self)?;
                         }
                     }
+
+                    // Outer aliases refer to a nested component by the name
+                    // printed above, which its parent gives it.
+                    #[cfg(feature = "component-model")]
+                    if let [.., parent, state] = &mut states[..] {
+                        if state.encoding == Encoding::Component {
+                            state.name = parent
+                                .component
+                                .component_names
+                                .index_to_name
+                                .get(&parent.component.components)
+                                .cloned();
+                        }
+                    }
                 }
                 Payload::CustomSection(c) => {
                     // If the custom printing trait handles this section, keep