11 files changed, 300 insertions, 37 deletions

diff --git a/Cargo.lock b/Cargo.lock
index cf88c4e17..7fecee1b5 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -775,9 +775,9 @@ dependencies = [
 
 [[package]]
 name = "lsp-types"
-version = "0.81.0"
+version = "0.82.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5e02724627e9ef8ba91f461ebc01d48aebbd13a4b7c9dc547a0a2890f53e2171"
+checksum = "db895abb8527cf59e3de893ab2acf52cf904faeb65e60ea6f373e11fe86464e8"
 dependencies = [
  "base64",
  "bitflags",
diff --git a/crates/hir/src/code_model.rs b/crates/hir/src/code_model.rs
index 849c8f6d0..a2a166e0a 100644
--- a/crates/hir/src/code_model.rs
+++ b/crates/hir/src/code_model.rs
@@ -709,11 +709,23 @@ impl Function {
     }
 
     pub fn params(self, db: &dyn HirDatabase) -> Vec<Param> {
+        let resolver = self.id.resolver(db.upcast());
+        let ctx = hir_ty::TyLoweringContext::new(db, &resolver);
+        let environment = TraitEnvironment::lower(db, &resolver);
         db.function_data(self.id)
             .params
             .iter()
             .skip(if self.self_param(db).is_some() { 1 } else { 0 })
-            .map(|_| Param { _ty: () })
+            .map(|type_ref| {
+                let ty = Type {
+                    krate: self.id.lookup(db.upcast()).container.module(db.upcast()).krate,
+                    ty: InEnvironment {
+                        value: Ty::from_hir_ext(&ctx, type_ref).0,
+                        environment: environment.clone(),
+                    },
+                };
+                Param { ty }
+            })
             .collect()
     }
 
@@ -742,15 +754,21 @@ impl From<Mutability> for Access {
     }
 }
 
+pub struct Param {
+    ty: Type,
+}
+
+impl Param {
+    pub fn ty(&self) -> &Type {
+        &self.ty
+    }
+}
+
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 pub struct SelfParam {
     func: FunctionId,
 }
 
-pub struct Param {
-    _ty: (),
-}
-
 impl SelfParam {
     pub fn access(self, db: &dyn HirDatabase) -> Access {
         let func_data = db.function_data(self.func);
@@ -1276,6 +1294,14 @@ impl Type {
         )
     }
 
+    pub fn remove_ref(&self) -> Option<Type> {
+        if let Ty::Apply(ApplicationTy { ctor: TypeCtor::Ref(_), .. }) = self.ty.value {
+            self.ty.value.substs().map(|substs| self.derived(substs[0].clone()))
+        } else {
+            None
+        }
+    }
+
     pub fn is_unknown(&self) -> bool {
         matches!(self.ty.value, Ty::Unknown)
     }
diff --git a/crates/ide/src/completion/complete_postfix.rs b/crates/ide/src/completion/complete_postfix.rs
index 84c4e129d..29d38661b 100644
--- a/crates/ide/src/completion/complete_postfix.rs
+++ b/crates/ide/src/completion/complete_postfix.rs
@@ -189,6 +189,16 @@ pub(super) fn complete_postfix(acc: &mut Completions, ctx: &CompletionContext) {
         ctx,
         cap,
         &dot_receiver,
+        "dbgr",
+        "dbg!(&expr)",
+        &format!("dbg!(&{})", receiver_text),
+    )
+    .add_to(acc);
+
+    postfix_snippet(
+        ctx,
+        cap,
+        &dot_receiver,
         "call",
         "function(expr)",
         &format!("${{1}}({})", receiver_text),
@@ -263,6 +273,7 @@ fn main() {
                 sn box   Box::new(expr)
                 sn call  function(expr)
                 sn dbg   dbg!(expr)
+                sn dbgr  dbg!(&expr)
                 sn if    if expr {}
                 sn match match expr {}
                 sn not   !expr
@@ -286,6 +297,7 @@ fn main() {
                 sn box   Box::new(expr)
                 sn call  function(expr)
                 sn dbg   dbg!(expr)
+                sn dbgr  dbg!(&expr)
                 sn match match expr {}
                 sn ref   &expr
                 sn refm  &mut expr
diff --git a/crates/ide/src/completion/completion_context.rs b/crates/ide/src/completion/completion_context.rs
index 161f59c1e..671b13328 100644
--- a/crates/ide/src/completion/completion_context.rs
+++ b/crates/ide/src/completion/completion_context.rs
@@ -1,7 +1,7 @@
 //! FIXME: write short doc here
 
 use base_db::SourceDatabase;
-use hir::{Semantics, SemanticsScope, Type};
+use hir::{Local, ScopeDef, Semantics, SemanticsScope, Type};
 use ide_db::RootDatabase;
 use syntax::{
     algo::{find_covering_element, find_node_at_offset},
@@ -91,6 +91,7 @@ pub(crate) struct CompletionContext<'a> {
     pub(super) impl_as_prev_sibling: bool,
     pub(super) is_match_arm: bool,
     pub(super) has_item_list_or_source_file_parent: bool,
+    pub(super) locals: Vec<(String, Local)>,
 }
 
 impl<'a> CompletionContext<'a> {
@@ -119,6 +120,12 @@ impl<'a> CompletionContext<'a> {
             original_file.syntax().token_at_offset(position.offset).left_biased()?;
         let token = sema.descend_into_macros(original_token.clone());
         let scope = sema.scope_at_offset(&token.parent(), position.offset);
+        let mut locals = vec![];
+        scope.process_all_names(&mut |name, scope| {
+            if let ScopeDef::Local(local) = scope {
+                locals.push((name.to_string(), local));
+            }
+        });
         let mut ctx = CompletionContext {
             sema,
             scope,
@@ -167,6 +174,7 @@ impl<'a> CompletionContext<'a> {
             if_is_prev: false,
             is_match_arm: false,
             has_item_list_or_source_file_parent: false,
+            locals,
         };
 
         let mut original_file = original_file.syntax().clone();
diff --git a/crates/ide/src/completion/presentation.rs b/crates/ide/src/completion/presentation.rs
index 24c507f9b..987cbfa7a 100644
--- a/crates/ide/src/completion/presentation.rs
+++ b/crates/ide/src/completion/presentation.rs
@@ -191,6 +191,17 @@ impl Completions {
         func: hir::Function,
         local_name: Option<String>,
     ) {
+        fn add_arg(arg: &str, ty: &Type, ctx: &CompletionContext) -> String {
+            if let Some(derefed_ty) = ty.remove_ref() {
+                for (name, local) in ctx.locals.iter() {
+                    if name == arg && local.ty(ctx.db) == derefed_ty {
+                        return (if ty.is_mutable_reference() { "&mut " } else { "&" }).to_string()
+                            + &arg.to_string();
+                    }
+                }
+            }
+            arg.to_string()
+        };
         let name = local_name.unwrap_or_else(|| func.name(ctx.db).to_string());
         let ast_node = func.source(ctx.db).value;
 
@@ -205,12 +216,20 @@ impl Completions {
                 .set_deprecated(is_deprecated(func, ctx.db))
                 .detail(function_declaration(&ast_node));
 
+        let params_ty = func.params(ctx.db);
         let params = ast_node
             .param_list()
             .into_iter()
             .flat_map(|it| it.params())
-            .flat_map(|it| it.pat())
-            .map(|pat| pat.to_string().trim_start_matches('_').into())
+            .zip(params_ty)
+            .flat_map(|(it, param_ty)| {
+                if let Some(pat) = it.pat() {
+                    let name = pat.to_string();
+                    let arg = name.trim_start_matches("mut ").trim_start_matches('_');
+                    return Some(add_arg(arg, param_ty.ty(), ctx));
+                }
+                None
+            })
             .collect();
 
         builder = builder.add_call_parens(ctx, name, Params::Named(params));
@@ -864,6 +883,106 @@ fn main() { foo(${1:foo}, ${2:bar}, ${3:ho_ge_})$0 }
     }
 
     #[test]
+    fn insert_ref_when_matching_local_in_scope() {
+        check_edit(
+            "ref_arg",
+            r#"
+struct Foo {}
+fn ref_arg(x: &Foo) {}
+fn main() {
+    let x = Foo {};
+    ref_ar<|>
+}
+"#,
+            r#"
+struct Foo {}
+fn ref_arg(x: &Foo) {}
+fn main() {
+    let x = Foo {};
+    ref_arg(${1:&x})$0
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn insert_mut_ref_when_matching_local_in_scope() {
+        check_edit(
+            "ref_arg",
+            r#"
+struct Foo {}
+fn ref_arg(x: &mut Foo) {}
+fn main() {
+    let x = Foo {};
+    ref_ar<|>
+}
+"#,
+            r#"
+struct Foo {}
+fn ref_arg(x: &mut Foo) {}
+fn main() {
+    let x = Foo {};
+    ref_arg(${1:&mut x})$0
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn insert_ref_when_matching_local_in_scope_for_method() {
+        check_edit(
+            "apply_foo",
+            r#"
+struct Foo {}
+struct Bar {}
+impl Bar {
+    fn apply_foo(&self, x: &Foo) {}
+}
+
+fn main() {
+    let x = Foo {};
+    let y = Bar {};
+    y.<|>
+}
+"#,
+            r#"
+struct Foo {}
+struct Bar {}
+impl Bar {
+    fn apply_foo(&self, x: &Foo) {}
+}
+
+fn main() {
+    let x = Foo {};
+    let y = Bar {};
+    y.apply_foo(${1:&x})$0
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn trim_mut_keyword_in_func_completion() {
+        check_edit(
+            "take_mutably",
+            r#"
+fn take_mutably(mut x: &i32) {}
+
+fn main() {
+    take_m<|>
+}
+"#,
+            r#"
+fn take_mutably(mut x: &i32) {}
+
+fn main() {
+    take_mutably(${1:x})$0
+}
+"#,
+        );
+    }
+
+    #[test]
     fn inserts_parens_for_tuple_enums() {
         mark::check!(inserts_parens_for_tuple_enums);
         check_edit(
diff --git a/crates/rust-analyzer/Cargo.toml b/crates/rust-analyzer/Cargo.toml
index 0fbb9cb0d..631ffc4a7 100644
--- a/crates/rust-analyzer/Cargo.toml
+++ b/crates/rust-analyzer/Cargo.toml
@@ -21,7 +21,7 @@ env_logger = { version = "0.7.1", default-features = false }
 itertools = "0.9.0"
 jod-thread = "0.1.0"
 log = "0.4.8"
-lsp-types = { version = "0.81.0", features = ["proposed"] }
+lsp-types = { version = "0.82.0", features = ["proposed"] }
 parking_lot = "0.11.0"
 pico-args = "0.3.1"
 oorandom = "11.1.2"
diff --git a/crates/rust-analyzer/src/caps.rs b/crates/rust-analyzer/src/caps.rs
index de4bc2813..c589afeaf 100644
--- a/crates/rust-analyzer/src/caps.rs
+++ b/crates/rust-analyzer/src/caps.rs
@@ -5,7 +5,7 @@ use lsp_types::{
     CallHierarchyServerCapability, ClientCapabilities, CodeActionKind, CodeActionOptions,
     CodeActionProviderCapability, CodeLensOptions, CompletionOptions,
     DocumentOnTypeFormattingOptions, FoldingRangeProviderCapability, HoverProviderCapability,
-    ImplementationProviderCapability, RenameOptions, RenameProviderCapability, SaveOptions,
+    ImplementationProviderCapability, OneOf, RenameOptions, SaveOptions,
     SelectionRangeProviderCapability, SemanticTokensFullOptions, SemanticTokensLegend,
     SemanticTokensOptions, ServerCapabilities, SignatureHelpOptions, TextDocumentSyncCapability,
     TextDocumentSyncKind, TextDocumentSyncOptions, TypeDefinitionProviderCapability,
@@ -42,16 +42,16 @@ pub fn server_capabilities(client_caps: &ClientCapabilities) -> ServerCapabiliti
             work_done_progress_options: WorkDoneProgressOptions { work_done_progress: None },
         }),
         declaration_provider: None,
-        definition_provider: Some(true),
+        definition_provider: Some(OneOf::Left(true)),
         type_definition_provider: Some(TypeDefinitionProviderCapability::Simple(true)),
         implementation_provider: Some(ImplementationProviderCapability::Simple(true)),
-        references_provider: Some(true),
-        document_highlight_provider: Some(true),
-        document_symbol_provider: Some(true),
+        references_provider: Some(OneOf::Left(true)),
+        document_highlight_provider: Some(OneOf::Left(true)),
+        document_symbol_provider: Some(OneOf::Left(true)),
         workspace_symbol_provider: Some(true),
         code_action_provider: Some(code_action_provider),
         code_lens_provider: Some(CodeLensOptions { resolve_provider: Some(true) }),
-        document_formatting_provider: Some(true),
+        document_formatting_provider: Some(OneOf::Left(true)),
         document_range_formatting_provider: None,
         document_on_type_formatting_provider: Some(DocumentOnTypeFormattingOptions {
             first_trigger_character: "=".to_string(),
@@ -60,7 +60,7 @@ pub fn server_capabilities(client_caps: &ClientCapabilities) -> ServerCapabiliti
         selection_range_provider: Some(SelectionRangeProviderCapability::Simple(true)),
         semantic_highlighting: None,
         folding_range_provider: Some(FoldingRangeProviderCapability::Simple(true)),
-        rename_provider: Some(RenameProviderCapability::Options(RenameOptions {
+        rename_provider: Some(OneOf::Right(RenameOptions {
             prepare_provider: Some(true),
             work_done_progress_options: WorkDoneProgressOptions { work_done_progress: None },
         })),
diff --git a/editors/code/package.json b/editors/code/package.json
index c57fbdda2..132664926 100644
--- a/editors/code/package.json
+++ b/editors/code/package.json
@@ -159,6 +159,11 @@
                 "category": "Rust Analyzer"
             },
             {
+                "command": "rust-analyzer.updateGithubToken",
+                "title": "Update Github API token",
+                "category": "Rust Analyzer"
+            },
+            {
                 "command": "rust-analyzer.onEnter",
                 "title": "Enhanced enter key",
                 "category": "Rust Analyzer"
@@ -985,6 +990,10 @@
                     "when": "inRustProject"
                 },
                 {
+                    "command": "rust-analyzer.updateGithubToken",
+                    "when": "inRustProject"
+                },
+                {
                     "command": "rust-analyzer.onEnter",
                     "when": "inRustProject"
                 },
diff --git a/editors/code/src/main.ts b/editors/code/src/main.ts
index bd99d696a..2896d90ac 100644
--- a/editors/code/src/main.ts
+++ b/editors/code/src/main.ts
@@ -95,6 +95,10 @@ async function tryActivate(context: vscode.ExtensionContext) {
         await activate(context).catch(log.error);
     });
 
+    ctx.registerCommand('updateGithubToken', ctx => async () => {
+        await queryForGithubToken(new PersistentState(ctx.globalState));
+    });
+
     ctx.registerCommand('analyzerStatus', commands.analyzerStatus);
     ctx.registerCommand('memoryUsage', commands.memoryUsage);
     ctx.registerCommand('reloadWorkspace', commands.reloadWorkspace);
@@ -173,7 +177,9 @@ async function bootstrapExtension(config: Config, state: PersistentState): Promi
         if (!shouldCheckForNewNightly) return;
     }
 
-    const release = await fetchRelease("nightly").catch((e) => {
+    const release = await downloadWithRetryDialog(state, async () => {
+        return await fetchRelease("nightly", state.githubToken);
+    }).catch((e) => {
         log.error(e);
         if (state.releaseId === undefined) { // Show error only for the initial download
             vscode.window.showErrorMessage(`Failed to download rust-analyzer nightly ${e}`);
@@ -192,10 +198,14 @@ async function bootstrapExtension(config: Config, state: PersistentState): Promi
     assert(!!artifact, `Bad release: ${JSON.stringify(release)}`);
 
     const dest = path.join(config.globalStoragePath, "rust-analyzer.vsix");
-    await download({
-        url: artifact.browser_download_url,
-        dest,
-        progressTitle: "Downloading rust-analyzer extension",
+
+    await downloadWithRetryDialog(state, async () => {
+        await download({
+            url: artifact.browser_download_url,
+            dest,
+            progressTitle: "Downloading rust-analyzer extension",
+            overwrite: true,
+        });
     });
 
     await vscode.commands.executeCommand("workbench.extensions.installExtension", vscode.Uri.file(dest));
@@ -308,21 +318,22 @@ async function getServer(config: Config, state: PersistentState): Promise<string
         if (userResponse !== "Download now") return dest;
     }
 
-    const release = await fetchRelease(config.package.releaseTag);
+    const releaseTag = config.package.releaseTag;
+    const release = await downloadWithRetryDialog(state, async () => {
+        return await fetchRelease(releaseTag, state.githubToken);
+    });
     const artifact = release.assets.find(artifact => artifact.name === `rust-analyzer-${platform}.gz`);
     assert(!!artifact, `Bad release: ${JSON.stringify(release)}`);
 
-    // Unlinking the exe file before moving new one on its place should prevent ETXTBSY error.
-    await fs.unlink(dest).catch(err => {
-        if (err.code !== "ENOENT") throw err;
-    });
-
-    await download({
-        url: artifact.browser_download_url,
-        dest,
-        progressTitle: "Downloading rust-analyzer server",
-        gunzip: true,
-        mode: 0o755
+    await downloadWithRetryDialog(state, async () => {
+        await download({
+            url: artifact.browser_download_url,
+            dest,
+            progressTitle: "Downloading rust-analyzer server",
+            gunzip: true,
+            mode: 0o755,
+            overwrite: true,
+        });
     });
 
     // Patching executable if that's NixOS.
@@ -333,3 +344,56 @@ async function getServer(config: Config, state: PersistentState): Promise<string
     await state.updateServerVersion(config.package.version);
     return dest;
 }
+
+async function downloadWithRetryDialog<T>(state: PersistentState, downloadFunc: () => Promise<T>): Promise<T> {
+    while (true) {
+        try {
+            return await downloadFunc();
+        } catch (e) {
+            const selected = await vscode.window.showErrorMessage("Failed to download: " + e.message, {}, {
+                title: "Update Github Auth Token",
+                updateToken: true,
+            }, {
+                title: "Retry download",
+                retry: true,
+            }, {
+                title: "Dismiss",
+            });
+
+            if (selected?.updateToken) {
+                await queryForGithubToken(state);
+                continue;
+            } else if (selected?.retry) {
+                continue;
+            }
+            throw e;
+        };
+    }
+}
+
+async function queryForGithubToken(state: PersistentState): Promise<void> {
+    const githubTokenOptions: vscode.InputBoxOptions = {
+        value: state.githubToken,
+        password: true,
+        prompt: `
+            This dialog allows to store a Github authorization token.
+            The usage of an authorization token will increase the rate
+            limit on the use of Github APIs and can thereby prevent getting
+            throttled.
+            Auth tokens can be created at https://github.com/settings/tokens`,
+    };
+
+    const newToken = await vscode.window.showInputBox(githubTokenOptions);
+    if (newToken === undefined) {
+        // The user aborted the dialog => Do not update the stored token
+        return;
+    }
+
+    if (newToken === "") {
+        log.info("Clearing github token");
+        await state.updateGithubToken(undefined);
+    } else {
+        log.info("Storing new github token");
+        await state.updateGithubToken(newToken);
+    }
+}
diff --git a/editors/code/src/net.ts b/editors/code/src/net.ts
index 5eba2728d..9ba17b7b5 100644
--- a/editors/code/src/net.ts
+++ b/editors/code/src/net.ts
@@ -18,7 +18,8 @@ const OWNER = "rust-analyzer";
 const REPO = "rust-analyzer";
 
 export async function fetchRelease(
-    releaseTag: string
+    releaseTag: string,
+    githubToken: string | null | undefined,
 ): Promise<GithubRelease> {
 
     const apiEndpointPath = `/repos/${OWNER}/${REPO}/releases/tags/${releaseTag}`;
@@ -27,7 +28,12 @@ export async function fetchRelease(
 
     log.debug("Issuing request for released artifacts metadata to", requestUrl);
 
-    const response = await fetch(requestUrl, { headers: { Accept: "application/vnd.github.v3+json" } });
+    const headers: Record<string, string> = { Accept: "application/vnd.github.v3+json" };
+    if (githubToken != null) {
+        headers.Authorization = "token " + githubToken;
+    }
+
+    const response = await fetch(requestUrl, { headers: headers });
 
     if (!response.ok) {
         log.error("Error fetching artifact release info", {
@@ -70,6 +76,7 @@ interface DownloadOpts {
     dest: string;
     mode?: number;
     gunzip?: boolean;
+    overwrite?: boolean;
 }
 
 export async function download(opts: DownloadOpts) {
@@ -79,6 +86,13 @@ export async function download(opts: DownloadOpts) {
     const randomHex = crypto.randomBytes(5).toString("hex");
     const tempFile = path.join(dest.dir, `${dest.name}${randomHex}`);
 
+    if (opts.overwrite) {
+        // Unlinking the exe file before moving new one on its place should prevent ETXTBSY error.
+        await fs.promises.unlink(opts.dest).catch(err => {
+            if (err.code !== "ENOENT") throw err;
+        });
+    }
+
     await vscode.window.withProgress(
         {
             location: vscode.ProgressLocation.Notification,
diff --git a/editors/code/src/persistent_state.ts b/editors/code/src/persistent_state.ts
index 5705eed81..afb652589 100644
--- a/editors/code/src/persistent_state.ts
+++ b/editors/code/src/persistent_state.ts
@@ -38,4 +38,15 @@ export class PersistentState {
     async updateServerVersion(value: string | undefined) {
         await this.globalState.update("serverVersion", value);
     }
+
+    /**
+     * Github authorization token.
+     * This is used for API requests against the Github API.
+     */
+    get githubToken(): string | undefined {
+        return this.globalState.get("githubToken");
+    }
+    async updateGithubToken(value: string | undefined) {
+        await this.globalState.update("githubToken", value);
+    }
 }