adding support for overriding toString in kotlin

rust-diplomat · Dec 3, 2024 · 0c32e7b · 0c32e7b
1 parent 9e627e2
commit 0c32e7b
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Showing 3 changed files with 42 additions and 10 deletions.
diff --git a/feature_tests/kotlin/somelib/src/main/kotlin/dev/diplomattest/somelib/Float64Vec.kt b/feature_tests/kotlin/somelib/src/main/kotlin/dev/diplomattest/somelib/Float64Vec.kt
diff --git a/tool/src/kotlin/formatter.rs b/tool/src/kotlin/formatter.rs
@@ -16,10 +16,11 @@ pub(super) struct KotlinFormatter<'tcx> {
     docs_url_gen: &'tcx DocsUrlGenerator,
 }
 
-const INVALID_METHOD_NAMES: &[&str] = &[
+const INVALID_RAW_METHOD_NAMES: &[&str] = &[
     "new", "static", "default", "private", "internal", "toString",
 ];
 const DISALLOWED_CORE_TYPES: &[&str] = &["Object", "String"];
+const OVERRIDE_METHOD_SIGS: &[&str] = &["fun toString(): String"];
 
 impl<'tcx> KotlinFormatter<'tcx> {
     pub fn new(
@@ -112,18 +113,37 @@ impl<'tcx> KotlinFormatter<'tcx> {
         }
     }
 
-    pub fn fmt_method_name<'a>(&self, method: &'a hir::Method) -> Cow<'a, str> {
+    pub fn fmt_method_name<'a>(
+        &self,
+        method: &'a hir::Method,
+        should_be_overridden: bool,
+    ) -> Cow<'a, str> {
         // TODO(#60): handle other keywords
 
         let name = method.name.as_str().to_lower_camel_case();
         let name = method.attrs.rename.apply(name.into());
-        if INVALID_METHOD_NAMES.contains(&&*name) {
+        if INVALID_RAW_METHOD_NAMES.contains(&&*name) && !should_be_overridden {
             format!("{name}_").into()
         } else {
             name
         }
     }
 
+    pub fn method_should_be_overridden<'a>(
+        &self,
+        method: &'a hir::Method,
+        params: &str,
+        return_type: &str,
+    ) -> bool {
+        let method_sig = format!(
+            "fun {}({}): {}",
+            &&*method.name.as_str().to_lower_camel_case(),
+            params,
+            return_type
+        );
+        OVERRIDE_METHOD_SIGS.contains(&&*method_sig)
+    }
+
     pub fn fmt_trait_method_name<'a>(&self, method: &'a hir::Callback) -> Cow<'a, str> {
         if method.name.is_none() {
             panic!("Trait methods need a name");
@@ -134,7 +154,7 @@ impl<'tcx> KotlinFormatter<'tcx> {
         } else {
             name.into()
         };
-        if INVALID_METHOD_NAMES.contains(&&*name) {
+        if INVALID_RAW_METHOD_NAMES.contains(&&*name) {
             format!("{name}_").into()
         } else {
             name

diff --git a/tool/src/kotlin/mod.rs b/tool/src/kotlin/mod.rs
@@ -1188,11 +1188,23 @@ returnVal.option() ?: return null
                     panic!("Can only have one iterable method per opaque struct")
                 }
             }
-            _ => format!(
-                "fun {}({}): {return_ty}",
-                self.formatter.fmt_method_name(method),
-                params
-            ),
+            _ => {
+                let should_be_overridden = self.formatter.method_should_be_overridden(
+                    method,
+                    &params,
+                    &return_ty.to_string(),
+                );
+                format!(
+                    "{}fun {}({}): {return_ty}",
+                    if should_be_overridden {
+                        "override "
+                    } else {
+                        ""
+                    },
+                    self.formatter.fmt_method_name(method, should_be_overridden),
+                    params
+                )
+            }
         };
 
         MethodTpl {