Implement find implementations extension

contributing.md

@@ -301,10 +301,29 @@ the RLS.
 
 The RLS uses some custom extensions to the Language Server Protocol.
 
-* `rustDocument/diagnosticsBegin`: notification, no arguments. Sent from the RLS
-  to a client before a build starts and before any diagnostics from a build are sent.
-* `rustDocument/diagnosticsEnd`: notification, no arguments. Sent from the RLS
-  to a client when a build is complete (successfully or not, or even skipped)
-  and all post-build analysis by the RLS is complete.
+#### RLS to LSP Client
+
+These are all sent from the RLS to an LSP client and are only used to improve
+the user experience by showing progress indicators.
+
+* `rustDocument/diagnosticsBegin`: notification, no arguments. Sent before a
+  build starts and before any diagnostics from a build are sent.
+* `rustDocument/diagnosticsEnd`: notification, no arguments. Sent when a build
+  is complete (successfully or not, or even skipped) and all post-build analysis
+  by the RLS is complete.
 * `rustWorkspace/deglob`: message sent from the client to the RLS to initiate a
   deglob refactoring.
+
+#### LSP Client to RLS
+
+The following request is to support Rust specific features.
+
+* `rustDocument/implementations`: request
+  params: [`TextDocumentPositionParams`]
+  result: [`Location`]`[]`
+
+  List all implementation blocks for a trait, struct, or enum denoted by the
+  given text document position.
+
+[`TextDocumentPositionParams`]: (https://github.com/Microsoft/language-server-protocol/blob/master/protocol.md#textdocumentpositionparams)
+[`Location`]: (https://github.com/Microsoft/language-server-protocol/blob/master/protocol.md#location)

src/actions/mod.rs

@@ -253,9 +253,32 @@ impl ActionHandler {
         });
     }
 
+    pub fn find_impls<O: Output>(&self, id: usize, params: TextDocumentPositionParams, out: O) {
+        let t = thread::current();
+        let file_path = parse_file_path!(&params.text_document.uri, "find_impls");
+        let span = self.convert_pos_to_span(file_path, params.position);
+        let type_id = self.analysis.id(&span).expect("Analysis: Getting typeid from span");
+        let analysis = self.analysis.clone();
+
+        let handle = thread::spawn(move || {
+            let result = analysis.find_impls(type_id).map(|spans| {
+                spans.into_iter().map(|x| ls_util::rls_to_location(&x)).collect()
+            });
+            t.unpark();
+            result
+        });
+        thread::park_timeout(Duration::from_millis(::COMPILER_TIMEOUT));
+
+        let result = handle.join();
+        trace!("find_impls: {:?}", result);
+        match result {
+            Ok(Ok(r)) => out.success(id, ResponseData::Locations(r)),
+            _ => out.failure_message(id, ErrorCode::InternalError, "Find Implementations failed to complete successfully"),
+        }
+    }
+
     pub fn on_open<O: Output>(&self, open: DidOpenTextDocumentParams, _out: O) {
         trace!("on_open: {:?}", open.text_document.uri);
-
         let file_path = parse_file_path!(&open.text_document.uri, "on_open");
 
         self.vfs.set_file(&file_path, &open.text_document.text);

src/server.rs

@@ -36,6 +36,11 @@ pub fn server_failure(id: jsonrpc::Id, error: jsonrpc::Error) -> jsonrpc::Failur
 #[allow(non_upper_case_globals)]
 pub const REQUEST__Deglob: &'static str = "rustWorkspace/deglob";
 
+#[cfg(test)]
+#[allow(non_upper_case_globals)]
+pub const REQUEST__FindImpls: &'static str = "rustDocument/implementations";
+
+
 #[derive(Debug, Serialize)]
 pub struct Ack;
 
@@ -290,6 +295,7 @@ messages! {
         "textDocument/codeAction" => CodeAction(CodeActionParams);
         "workspace/executeCommand" => ExecuteCommand(ExecuteCommandParams);
         "rustWorkspace/deglob" => Deglob(Location);
+        "rustDocument/implementations" => FindImpls(TextDocumentPositionParams);
     }
     notifications {
         "initialized" => Initialized;
@@ -518,6 +524,7 @@ impl<O: Output> LsService<O> {
                 Deglob(params) => { action: deglob };
                 ExecuteCommand(params) => { action: execute_command };
                 CodeAction(params) => { action: code_action };
+                FindImpls(params) => { action: find_impls };
             }
             notifications {
                 Initialized => {{ self.handler.inited().initialized(self.output.clone()) }};

src/test/mod.rs

@@ -581,3 +581,69 @@ fn test_parse_error_on_malformed_input() {
 
     assert!(failure.error.code == jsonrpc_core::ErrorCode::ParseError);
 }
+
+#[test]
+fn test_find_impls() {
+    let (mut cache, _tc) = init_env("find_impls");
+
+    let source_file_path = Path::new("src").join("main.rs");
+
+    let root_path = cache.abs_path(Path::new("."));
+    let url = Url::from_file_path(cache.abs_path(&source_file_path))
+        .expect("couldn't convert file path to URL");
+
+    // This test contains code for testing implementations of `Eq`. However, `rust-analysis` is not
+    // installed on Travis making rls-analysis fail why retrieving the typeid. Installing
+    // `rust-analysis` is also not an option, because this makes other test timeout.
+    // e.g., https://travis-ci.org/rust-lang-nursery/rls/jobs/265339002
+
+    let messages = vec![
+        ServerMessage::initialize(0,root_path.as_os_str().to_str().map(|x| x.to_owned())),
+        ServerMessage::request(1, Method::FindImpls(TextDocumentPositionParams {
+            text_document: TextDocumentIdentifier::new(url.clone()),
+            position: cache.mk_ls_position(src(&source_file_path, 13, "Bar"))
+        })),
+        ServerMessage::request(2, Method::FindImpls(TextDocumentPositionParams {
+            text_document: TextDocumentIdentifier::new(url.clone()),
+            position: cache.mk_ls_position(src(&source_file_path, 16, "Super"))
+        })),
+        // Does not work on Travis
+        // ServerMessage::request(3, Method::FindImpls(TextDocumentPositionParams {
+        //     text_document: TextDocumentIdentifier::new(url),
+        //     position: cache.mk_ls_position(src(&source_file_path, 20, "Eq"))
+        // })),
+    ];
+
+    let (mut server, results) = mock_server(messages);
+    // Initialise and build.
+    assert_eq!(ls_server::LsService::handle_message(&mut server),
+               ls_server::ServerStateChange::Continue);
+    expect_messages(results.clone(),
+                    &[ExpectedMessage::new(Some(0)).expect_contains("capabilities"),
+                      ExpectedMessage::new(None).expect_contains("diagnosticsBegin"),
+                      ExpectedMessage::new(None).expect_contains("diagnosticsEnd")]);
+
+    assert_eq!(ls_server::LsService::handle_message(&mut server),
+               ls_server::ServerStateChange::Continue);
+    // TODO structural checking of result, rather than looking for a string - src(&source_file_path, 12, "world")
+    expect_messages(results.clone(), &[
+        ExpectedMessage::new(Some(1))
+            .expect_contains(r#""range":{"start":{"line":18,"character":15},"end":{"line":18,"character":18}}"#)
+            .expect_contains(r#""range":{"start":{"line":19,"character":12},"end":{"line":19,"character":15}}"#)
+    ]);
+    assert_eq!(ls_server::LsService::handle_message(&mut server),
+               ls_server::ServerStateChange::Continue);
+    expect_messages(results.clone(), &[
+        ExpectedMessage::new(Some(2))
+            .expect_contains(r#""range":{"start":{"line":18,"character":15},"end":{"line":18,"character":18}}"#)
+            .expect_contains(r#""range":{"start":{"line":22,"character":15},"end":{"line":22,"character":18}}"#)
+    ]);
+    // Does not work on Travis
+    // assert_eq!(ls_server::LsService::handle_message(&mut server),
+    //            ls_server::ServerStateChange::Continue);
+    // expect_messages(results.clone(), &[
+    //     // TODO assert that only one position is returned
+    //     ExpectedMessage::new(Some(3))
+    //         .expect_contains(r#""range":{"start":{"line":19,"character":12},"end":{"line":19,"character":15}}"#)
+    // ]);
+}

test_data/find_impls/Cargo.toml

@@ -0,0 +1,6 @@
+[package]
+name = "find_impls"
+version = "0.1.0"
+authors = ["Jonas Bushart <[email protected]>"]
+
+[dependencies]

test_data/find_impls/src/main.rs

@@ -0,0 +1,23 @@
+// Copyright 2017 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+#![allow(dead_code)]
+
+#[derive(PartialEq)]
+struct Bar;
+struct Foo;
+
+trait Super{}
+trait Sub: Super {}
+
+impl Super for Bar {}
+impl Eq for Bar {}
+
+impl Sub for Foo {}
+impl Super for Foo {}