2 files changed, 33 insertions, 16 deletions

diff --git a/editors/code/rust.tmGrammar.json b/editors/code/rust.tmGrammar.json
index 77595aa00..b3a10795e 100644
--- a/editors/code/rust.tmGrammar.json
+++ b/editors/code/rust.tmGrammar.json
@@ -50,7 +50,7 @@
         {
             "comment": "macro type metavariables",
             "name": "meta.macro.metavariable.type.rust",
-            "match": "(\\$)((crate)|([A-Z][A-Za-z0-9_]*))((:)(block|expr|ident|item|lifetime|literal|meta|pat|path|stmt|tt|ty|vis))?",
+            "match": "(\\$)((crate)|([A-Z][A-Za-z0-9_]*))((:)(block|expr|ident|item|lifetime|literal|meta|path?|stmt|tt|ty|vis))?",
             "captures": {
                 "1": {
                     "name": "keyword.operator.macro.dollar.rust"
@@ -77,7 +77,7 @@
         {
             "comment": "macro metavariables",
             "name": "meta.macro.metavariable.rust",
-            "match": "(\\$)([a-z][A-Za-z0-9_]*)((:)(block|expr|ident|item|lifetime|literal|meta|pat|path|stmt|tt|ty|vis))?",
+            "match": "(\\$)([a-z][A-Za-z0-9_]*)((:)(block|expr|ident|item|lifetime|literal|meta|path?|stmt|tt|ty|vis))?",
             "captures": {
                 "1": {
                     "name": "keyword.operator.macro.dollar.rust"
@@ -167,7 +167,7 @@
             "match": "(mod)\\s+((?:r#(?!crate|[Ss]elf|super))?[a-z][A-Za-z0-9_]*)",
             "captures": {
                 "1": {
-                    "name": "keyword.control.rust"
+                    "name": "storage.type.rust"
                 },
                 "2": {
                     "name": "entity.name.module.rust"
@@ -180,7 +180,7 @@
             "begin": "\\b(extern)\\s+(crate)",
             "beginCaptures": {
                 "1": {
-                    "name": "keyword.control.rust"
+                    "name": "storage.type.rust"
                 },
                 "2": {
                     "name": "keyword.other.crate.rust"
@@ -213,7 +213,7 @@
             "begin": "\\b(use)\\s",
             "beginCaptures": {
                 "1": {
-                    "name": "keyword.control.rust"
+                    "name": "keyword.other.rust"
                 }
             },
             "end": ";",
@@ -342,7 +342,7 @@
                     "match": "\\b(const)\\s+([A-Z][A-Za-z0-9_]*)\\b",
                     "captures": {
                         "1": {
-                            "name": "keyword.control.rust"
+                            "name": "storage.type.rust"
                         },
                         "2": {
                             "name": "constant.other.caps.rust"
@@ -450,7 +450,7 @@
                     "begin": "\\b(fn)\\s+((?:r#(?!crate|[Ss]elf|super))?[A-Za-z0-9_]+)((\\()|(<))",
                     "beginCaptures": {
                         "1": {
-                            "name": "keyword.control.fn.rust"
+                            "name": "keyword.other.fn.rust"
                         },
                         "2": {
                             "name": "entity.name.function.rust"
@@ -643,7 +643,7 @@
                 {
                     "comment": "control flow keywords",
                     "name": "keyword.control.rust",
-                    "match": "\\b(async|await|break|continue|do|else|for|if|loop|match|move|return|try|where|while|yield)\\b"
+                    "match": "\\b(await|break|continue|do|else|for|if|loop|match|return|try|while|yield)\\b"
                 },
                 {
                     "comment": "storage keywords",
@@ -658,7 +658,7 @@
                 {
                     "comment": "other keywords",
                     "name": "keyword.other.rust",
-                    "match": "\\b(as|become|box|dyn|final|impl|in|override|priv|pub|ref|typeof|union|unsafe|unsized|use|virtual)\\b"
+                    "match": "\\b(as|async|become|box|dyn|move|final|impl|in|override|priv|pub|ref|typeof|union|unsafe|unsized|use|virtual|where)\\b"
                 },
                 {
                     "comment": "fn",
@@ -676,11 +676,6 @@
                     "match": "\\bmut\\b"
                 },
                 {
-                    "comment": "math operators",
-                    "name": "keyword.operator.math.rust",
-                    "match": "(([+%]|(\\*(?!\\w)))(?!=))|(-(?!>))|(/(?!/))"
-                },
-                {
                     "comment": "logical operators",
                     "name": "keyword.operator.logical.rust",
                     "match": "(\\^|\\||\\|\\||&&|<<|>>|!)(?!=)"
@@ -693,7 +688,7 @@
                 {
                     "comment": "assignment operators",
                     "name": "keyword.operator.assignment.rust",
-                    "match": "(-=|\\*=|/=|%=|\\^=|&=|\\|=|<<=|>>=)"
+                    "match": "(\\+=|-=|\\*=|/=|%=|\\^=|&=|\\|=|<<=|>>=)"
                 },
                 {
                     "comment": "single equal",
@@ -706,6 +701,11 @@
                     "match": "(=(=)?(?!>)|!=|<=|(?<!=)>=)"
                 },
                 {
+                    "comment": "math operators",
+                    "name": "keyword.operator.math.rust",
+                    "match": "(([+%]|(\\*(?!\\w)))(?!=))|(-(?!>))|(/(?!/))"
+                },
+                {
                     "comment": "less than, greater than (special case)",
                     "match": "(?:\\b|(?:(\\))|(\\])|(\\})))[ \\t]+([<>])[ \\t]+(?:\\b|(?:(\\()|(\\[)|(\\{)))",
                     "captures": {
@@ -1127,7 +1127,7 @@
                 {
                     "comment": "variables",
                     "name": "variable.other.rust",
-                    "match": "\\b(?<!\\.)(?:r#(?!(crate|[Ss]elf|super)))?[a-z0-9_]+\\b"
+                    "match": "\\b(?<!(?<!\\.)\\.)(?:r#(?!(crate|[Ss]elf|super)))?[a-z0-9_]+\\b"
                 }
             ]
         }
diff --git a/editors/code/src/client.ts b/editors/code/src/client.ts
index 1ba2352ee..d032b45b7 100644
--- a/editors/code/src/client.ts
+++ b/editors/code/src/client.ts
@@ -2,6 +2,7 @@ import * as lc from 'vscode-languageclient/node';
 import * as vscode from 'vscode';
 import * as ra from '../src/lsp_ext';
 import * as Is from 'vscode-languageclient/lib/common/utils/is';
+import { DocumentSemanticsTokensSignature, DocumentSemanticsTokensEditsSignature, DocumentRangeSemanticTokensSignature } from 'vscode-languageclient/lib/common/semanticTokens';
 import { assert } from './util';
 
 function renderCommand(cmd: ra.CommandLink) {
@@ -18,6 +19,13 @@ function renderHoverActions(actions: ra.CommandLinkGroup[]): vscode.MarkdownStri
     return result;
 }
 
+// Workaround for https://github.com/microsoft/vscode-languageserver-node/issues/576
+async function semanticHighlightingWorkaround<R, F extends (...args: any[]) => vscode.ProviderResult<R>>(next: F, ...args: Parameters<F>): Promise<R> {
+    const res = await next(...args);
+    if (res == null) throw new Error('busy');
+    return res;
+}
+
 export function createClient(serverPath: string, cwd: string): lc.LanguageClient {
     // '.' Is the fallback if no folder is open
     // TODO?: Workspace folders support Uri's (eg: file://test.txt).
@@ -41,6 +49,15 @@ export function createClient(serverPath: string, cwd: string): lc.LanguageClient
         diagnosticCollectionName: "rustc",
         traceOutputChannel,
         middleware: {
+            provideDocumentSemanticTokens(document: vscode.TextDocument, token: vscode.CancellationToken, next: DocumentSemanticsTokensSignature): vscode.ProviderResult<vscode.SemanticTokens> {
+                return semanticHighlightingWorkaround(next, document, token);
+            },
+            provideDocumentSemanticTokensEdits(document: vscode.TextDocument, previousResultId: string, token: vscode.CancellationToken, next: DocumentSemanticsTokensEditsSignature): vscode.ProviderResult<vscode.SemanticTokensEdits | vscode.SemanticTokens> {
+                return semanticHighlightingWorkaround(next, document, previousResultId, token);
+            },
+            provideDocumentRangeSemanticTokens(document: vscode.TextDocument, range: vscode.Range, token: vscode.CancellationToken, next: DocumentRangeSemanticTokensSignature): vscode.ProviderResult<vscode.SemanticTokens> {
+                return semanticHighlightingWorkaround(next, document, range, token);
+            },
             async provideHover(document: vscode.TextDocument, position: vscode.Position, token: vscode.CancellationToken, _next: lc.ProvideHoverSignature) {
                 return client.sendRequest(lc.HoverRequest.type, client.code2ProtocolConverter.asTextDocumentPositionParams(document, position), token).then(
                     (result) => {