10 files changed, 183 insertions, 49 deletions

diff --git a/editors/code/package-lock.json b/editors/code/package-lock.json
index 0288a468e..6901363fc 100644
--- a/editors/code/package-lock.json
+++ b/editors/code/package-lock.json
@@ -112,12 +112,6 @@
                 "@types/node": "*"
             }
         },
-        "@types/throttle-debounce": {
-            "version": "2.1.0",
-            "resolved": "https://registry.npmjs.org/@types/throttle-debounce/-/throttle-debounce-2.1.0.tgz",
-            "integrity": "sha512-5eQEtSCoESnh2FsiLTxE121IiE60hnMqcb435fShf4bpLRjEu1Eoekht23y6zXS9Ts3l+Szu3TARnTsA0GkOkQ==",
-            "dev": true
-        },
         "@types/vscode": {
             "version": "1.42.0",
             "resolved": "https://registry.npmjs.org/@types/vscode/-/vscode-1.42.0.tgz",
@@ -1517,11 +1511,6 @@
             "integrity": "sha1-f17oI66AUgfACvLfSoTsP8+lcLQ=",
             "dev": true
         },
-        "throttle-debounce": {
-            "version": "2.1.0",
-            "resolved": "https://registry.npmjs.org/throttle-debounce/-/throttle-debounce-2.1.0.tgz",
-            "integrity": "sha512-AOvyNahXQuU7NN+VVvOOX+uW6FPaWdAOdRP5HfwYxAfCzXTFKRMoIMk+n+po318+ktcChx+F1Dd91G3YHeMKyg=="
-        },
         "through": {
             "version": "2.3.8",
             "resolved": "https://registry.npmjs.org/through/-/through-2.3.8.tgz",
diff --git a/editors/code/package.json b/editors/code/package.json
index dff535fcd..862de3210 100644
--- a/editors/code/package.json
+++ b/editors/code/package.json
@@ -18,16 +18,17 @@
     "engines": {
         "vscode": "^1.42.0"
     },
+    "enableProposedApi": true,
     "scripts": {
         "vscode:prepublish": "tsc && rollup -c",
         "package": "vsce package -o rust-analyzer.vsix",
         "watch": "tsc --watch",
-        "fmt": "tsfmt -r && eslint -c .eslintrc.js --ext ts ./src/ --fix"
+        "lint": "tsfmt --verify && eslint -c .eslintrc.js --ext ts ./src",
+        "fix": " tsfmt -r       && eslint -c .eslintrc.js --ext ts ./src --fix"
     },
     "dependencies": {
         "jsonc-parser": "^2.1.0",
         "node-fetch": "^2.6.0",
-        "throttle-debounce": "^2.1.0",
         "vscode-languageclient": "^6.1.1"
     },
     "devDependencies": {
@@ -35,7 +36,6 @@
         "@rollup/plugin-node-resolve": "^7.1.1",
         "@types/node": "^12.12.27",
         "@types/node-fetch": "^2.5.4",
-        "@types/throttle-debounce": "^2.1.0",
         "@types/vscode": "^1.42.0",
         "@typescript-eslint/eslint-plugin": "^2.20.0",
         "@typescript-eslint/parser": "^2.20.0",
@@ -155,20 +155,20 @@
                 "when": "editorTextFocus && editorLangId == rust"
             },
             {
-                "command": "rust-analyzer.run",
-                "key": "ctrl+r",
-                "when": "editorTextFocus && editorLangId == rust"
-            },
-            {
                 "command": "rust-analyzer.onEnter",
                 "key": "enter",
-                "when": "editorTextFocus && !suggestWidgetVisible && editorLangId == rust"
+                "when": "editorTextFocus && !suggestWidgetVisible && editorLangId == rust && !vim.active || vim.mode == 'Insert' && editorTextFocus && !suggestWidgetVisible && editorLangId == rust"
             }
         ],
         "configuration": {
             "type": "object",
             "title": "Rust Analyzer",
             "properties": {
+                "rust-analyzer.highlighting.semanticTokens": {
+                    "type": "boolean",
+                    "default": false,
+                    "description": "Use proposed semantic tokens API for syntax highlighting"
+                },
                 "rust-analyzer.highlightingOn": {
                     "type": "boolean",
                     "default": false,
@@ -182,7 +182,29 @@
                 "rust-analyzer.featureFlags": {
                     "type": "object",
                     "default": {},
-                    "description": "Fine grained feature flags to disable annoying features"
+                    "description": "Fine grained feature flags to disable annoying features",
+                    "properties": {
+                        "lsp.diagnostics": {
+                            "type": "boolean",
+                            "description": "Whether to show diagnostics from `cargo check`"
+                        },
+                        "completion.insertion.add-call-parenthesis": {
+                            "type": "boolean",
+                            "description": "Whether to add parenthesis when completing functions"
+                        },
+                        "completion.enable-postfix": {
+                            "type": "boolean",
+                            "description": "Whether to show postfix snippets like `dbg`, `if`, `not`, etc."
+                        },
+                        "notifications.workspace-loaded": {
+                            "type": "boolean",
+                            "description": "Whether to show `workspace loaded` message"
+                        },
+                        "notifications.cargo-toml-not-found": {
+                            "type": "boolean",
+                            "description": "Whether to show `can't find Cargo.toml` error message"
+                        }
+                    }
                 },
                 "rust-analyzer.serverPath": {
                     "type": [
@@ -375,6 +397,108 @@
                     "highContrast": "#BEBEBE"
                 }
             }
+        ],
+        "semanticTokenTypes": [
+            {
+                "id": "attribute",
+                "description": "Style for attributes"
+            },
+            {
+                "id": "builtinType",
+                "description": "Style for builtin types"
+            },
+            {
+                "id": "lifetime",
+                "description": "Style for lifetimes"
+            },
+            {
+                "id": "typeAlias",
+                "description": "Style for type aliases"
+            },
+            {
+                "id": "union",
+                "description": "Style for C-style untagged unions"
+            }
+        ],
+        "semanticTokenModifiers": [
+            {
+                "id": "constant",
+                "description": "Style for compile-time constants"
+            },
+            {
+                "id": "control",
+                "description": "Style for control flow keywords"
+            },
+            {
+                "id": "mutable",
+                "description": "Style for mutable bindings"
+            },
+            {
+                "id": "unsafe",
+                "description": "Style for unsafe operations"
+            }
+        ],
+        "semanticTokenStyleDefaults": [
+            {
+                "selector": "attribute",
+                "scope": [
+                    "meta.attribute"
+                ]
+            },
+            {
+                "selector": "builtinType",
+                "scope": [
+                    "support.type.primitive"
+                ]
+            },
+            {
+                "selector": "lifetime",
+                "scope": [
+                    "entity.name.lifetime.rust"
+                ]
+            },
+            {
+                "selector": "typeAlias",
+                "scope": [
+                    "entity.name.typeAlias"
+                ]
+            },
+            {
+                "selector": "union",
+                "scope": [
+                    "entity.name.union"
+                ]
+            },
+            {
+                "selector": "keyword.unsafe",
+                "scope": [
+                    "keyword.other.unsafe"
+                ]
+            },
+            {
+                "selector": "keyword.control",
+                "scope": [
+                    "keyword.control"
+                ]
+            },
+            {
+                "selector": "variable.constant",
+                "scope": [
+                    "entity.name.constant"
+                ]
+            },
+            {
+                "selector": "*.mutable",
+                "light": {
+                    "fontStyle": "underline"
+                },
+                "dark": {
+                    "fontStyle": "underline"
+                },
+                "highContrast": {
+                    "fontStyle": "underline"
+                }
+            }
         ]
     }
 }
diff --git a/editors/code/src/client.ts b/editors/code/src/client.ts
index aaf2ef40e..540f7c9ea 100644
--- a/editors/code/src/client.ts
+++ b/editors/code/src/client.ts
@@ -3,6 +3,7 @@ import * as vscode from 'vscode';
 
 import { Config } from './config';
 import { CallHierarchyFeature } from 'vscode-languageclient/lib/callHierarchy.proposed';
+import { SemanticTokensFeature, DocumentSemanticsTokensSignature } from 'vscode-languageclient/lib/semanticTokens.proposed';
 
 export async function createClient(config: Config, serverPath: string): Promise<lc.LanguageClient> {
     // '.' Is the fallback if no folder is open
@@ -26,7 +27,7 @@ export async function createClient(config: Config, serverPath: string): Promise<
     const clientOptions: lc.LanguageClientOptions = {
         documentSelector: [{ scheme: 'file', language: 'rust' }],
         initializationOptions: {
-            publishDecorations: true,
+            publishDecorations: !config.highlightingSemanticTokens,
             lruCapacity: config.lruCapacity,
             maxInlayHintLength: config.maxInlayHintLength,
             cargoWatchEnable: cargoWatchOpts.enable,
@@ -41,6 +42,14 @@ export async function createClient(config: Config, serverPath: string): Promise<
             rustfmtArgs: config.rustfmtArgs,
         },
         traceOutputChannel,
+        middleware: {
+            // Workaround for https://github.com/microsoft/vscode-languageserver-node/issues/576
+            async provideDocumentSemanticTokens(document: vscode.TextDocument, token: vscode.CancellationToken, next: DocumentSemanticsTokensSignature) {
+                const res = await next(document, token);
+                if (res === undefined) throw new Error('busy');
+                return res;
+            }
+        } as any
     };
 
     const res = new lc.LanguageClient(
@@ -83,5 +92,10 @@ export async function createClient(config: Config, serverPath: string): Promise<
     // Here we want to just enable CallHierarchyFeature since it is available on stable.
     // Note that while the CallHierarchyFeature is stable the LSP protocol is not.
     res.registerFeature(new CallHierarchyFeature(res));
+
+    if (config.highlightingSemanticTokens) {
+        res.registerFeature(new SemanticTokensFeature(res));
+    }
+
     return res;
 }
diff --git a/editors/code/src/config.ts b/editors/code/src/config.ts
index 47e8cd45d..bf915102c 100644
--- a/editors/code/src/config.ts
+++ b/editors/code/src/config.ts
@@ -22,6 +22,7 @@ export class Config {
     private static readonly requiresReloadOpts = [
         "cargoFeatures",
         "cargo-watch",
+        "highlighting.semanticTokens"
     ]
         .map(opt => `${Config.rootSection}.${opt}`);
 
@@ -143,6 +144,7 @@ export class Config {
     // We don't do runtime config validation here for simplicity. More on stackoverflow:
     // https://stackoverflow.com/questions/60135780/what-is-the-best-way-to-type-check-the-configuration-for-vscode-extension
 
+    get highlightingSemanticTokens() { return this.cfg.get("highlighting.semanticTokens") as boolean; }
     get highlightingOn() { return this.cfg.get("highlightingOn") as boolean; }
     get rainbowHighlightingOn() { return this.cfg.get("rainbowHighlightingOn") as boolean; }
     get lruCapacity() { return this.cfg.get("lruCapacity") as null | number; }
diff --git a/editors/code/src/inlay_hints.ts b/editors/code/src/inlay_hints.ts
index 5951cf1b4..6871bc111 100644
--- a/editors/code/src/inlay_hints.ts
+++ b/editors/code/src/inlay_hints.ts
@@ -42,12 +42,14 @@ export function activateInlayHints(ctx: Ctx) {
 const typeHintDecorationType = vscode.window.createTextEditorDecorationType({
     after: {
         color: new vscode.ThemeColor('rust_analyzer.inlayHint'),
+        fontStyle: "normal",
     },
 });
 
 const parameterHintDecorationType = vscode.window.createTextEditorDecorationType({
     before: {
         color: new vscode.ThemeColor('rust_analyzer.inlayHint'),
+        fontStyle: "normal",
     },
 });
 
diff --git a/editors/code/src/installation/download_artifact.ts b/editors/code/src/installation/download_artifact.ts
index 356723aba..97e4d67c2 100644
--- a/editors/code/src/installation/download_artifact.ts
+++ b/editors/code/src/installation/download_artifact.ts
@@ -1,11 +1,10 @@
 import * as vscode from "vscode";
 import * as path from "path";
 import { promises as fs } from "fs";
-import { strict as assert } from "assert";
 
 import { ArtifactReleaseInfo } from "./interfaces";
 import { downloadFile } from "./download_file";
-import { throttle } from "throttle-debounce";
+import { assert } from "../util";
 
 /**
  * Downloads artifact from given `downloadUrl`.
@@ -20,11 +19,10 @@ export async function downloadArtifact(
     installationDir: string,
     displayName: string,
 ) {
-    await fs.mkdir(installationDir).catch(err => assert.strictEqual(
-        err?.code,
-        "EEXIST",
+    await fs.mkdir(installationDir).catch(err => assert(
+        err?.code === "EEXIST",
         `Couldn't create directory "${installationDir}" to download ` +
-        `${artifactFileName} artifact: ${err.message}`
+        `${artifactFileName} artifact: ${err?.message}`
     ));
 
     const installationPath = path.join(installationDir, artifactFileName);
@@ -38,19 +36,15 @@ export async function downloadArtifact(
         async (progress, _cancellationToken) => {
             let lastPrecentage = 0;
             const filePermissions = 0o755; // (rwx, r_x, r_x)
-            await downloadFile(downloadUrl, installationPath, filePermissions, throttle(
-                200,
-                /* noTrailing: */ true,
-                (readBytes, totalBytes) => {
-                    const newPercentage = (readBytes / totalBytes) * 100;
-                    progress.report({
-                        message: newPercentage.toFixed(0) + "%",
-                        increment: newPercentage - lastPrecentage
-                    });
+            await downloadFile(downloadUrl, installationPath, filePermissions, (readBytes, totalBytes) => {
+                const newPercentage = (readBytes / totalBytes) * 100;
+                progress.report({
+                    message: newPercentage.toFixed(0) + "%",
+                    increment: newPercentage - lastPrecentage
+                });
 
-                    lastPrecentage = newPercentage;
-                })
-            );
+                lastPrecentage = newPercentage;
+            });
         }
     );
 }
diff --git a/editors/code/src/installation/download_file.ts b/editors/code/src/installation/download_file.ts
index 319cb995c..ee8949d61 100644
--- a/editors/code/src/installation/download_file.ts
+++ b/editors/code/src/installation/download_file.ts
@@ -2,8 +2,7 @@ import fetch from "node-fetch";
 import * as fs from "fs";
 import * as stream from "stream";
 import * as util from "util";
-import { strict as assert } from "assert";
-import { log } from "../util";
+import { log, assert } from "../util";
 
 const pipeline = util.promisify(stream.pipeline);
 
diff --git a/editors/code/src/installation/server.ts b/editors/code/src/installation/server.ts
index cb5e56844..6a6cf4f8c 100644
--- a/editors/code/src/installation/server.ts
+++ b/editors/code/src/installation/server.ts
@@ -1,13 +1,12 @@
 import * as vscode from "vscode";
 import * as path from "path";
-import { strict as assert } from "assert";
 import { promises as dns } from "dns";
 import { spawnSync } from "child_process";
 
 import { BinarySource } from "./interfaces";
 import { fetchArtifactReleaseInfo } from "./fetch_artifact_release_info";
 import { downloadArtifact } from "./download_artifact";
-import { log } from "../util";
+import { log, assert } from "../util";
 
 export async function ensureServerBinary(source: null | BinarySource): Promise<null | string> {
     if (!source) {
diff --git a/editors/code/src/main.ts b/editors/code/src/main.ts
index 424ff1ac3..ecf53cf77 100644
--- a/editors/code/src/main.ts
+++ b/editors/code/src/main.ts
@@ -89,7 +89,9 @@ export async function activate(context: vscode.ExtensionContext) {
 
     activateStatusDisplay(ctx);
 
-    activateHighlighting(ctx);
+    if (!ctx.config.highlightingSemanticTokens) {
+        activateHighlighting(ctx);
+    }
     activateInlayHints(ctx);
 }
 
diff --git a/editors/code/src/util.ts b/editors/code/src/util.ts
index 68c2a94d0..f56c6bada 100644
--- a/editors/code/src/util.ts
+++ b/editors/code/src/util.ts
@@ -1,22 +1,31 @@
 import * as lc from "vscode-languageclient";
 import * as vscode from "vscode";
+import { strict as nativeAssert } from "assert";
 
-let enabled: boolean = false;
+export function assert(condition: boolean, explanation: string): asserts condition {
+    try {
+        nativeAssert(condition, explanation);
+    } catch (err) {
+        log.error(`Assertion failed:`, explanation);
+        throw err;
+    }
+}
 
 export const log = {
+    enabled: true,
     debug(message?: any, ...optionalParams: any[]): void {
-        if (!enabled) return;
+        if (!log.enabled) return;
         // eslint-disable-next-line no-console
         console.log(message, ...optionalParams);
     },
     error(message?: any, ...optionalParams: any[]): void {
-        if (!enabled) return;
+        if (!log.enabled) return;
         debugger;
         // eslint-disable-next-line no-console
         console.error(message, ...optionalParams);
     },
     setEnabled(yes: boolean): void {
-        enabled = yes;
+        log.enabled = yes;
     }
 };