Add processFilter for remote attach process selection

Extension/package.json

@@ -5260,6 +5260,11 @@
                                     }
                                 ]
                             },
+                            "processFilter": {
+                                "type": "string",
+                                "description": "%c_cpp.debuggers.processFilter.description%",
+                                "default": ""
+                            },
                             "filterStdout": {
                                 "type": "boolean",
                                 "description": "%c_cpp.debuggers.filterStdout.description%",

Extension/package.nls.json

@@ -982,6 +982,7 @@
             "{Locked=\"`${command:pickProcess}`\"}"
         ]
     },
+    "c_cpp.debuggers.processFilter.description": "Optional regular expression used to match remote attach candidates by label, description, or detail. If exactly one process matches, the debugger attaches automatically. If multiple processes match, the process picker is shown with only matching entries. If no process matches, the full process picker is shown. An invalid regular expression reports an error.",
     "c_cpp.debuggers.program.attach.markdownDescription": {
         "message": "Full path to the program executable. The debugger will search for a running process matching this executable path and attach to it. If multiple processes match, a selection prompt will be shown. This field is required to load debug symbols for the attached process.",
         "comment": [

Extension/src/Debugger/attachToProcess.ts

@@ -6,6 +6,7 @@
 import { CppSettings } from '../LanguageServer/settings';
 import { AttachItem, showQuickPick } from './attachQuickPick';
 import { PsProcessParser } from './nativeAttach';
+import { filterProcessItems } from './processFilter';
 
 import * as os from 'os';
 import * as path from 'path';
@@ -94,6 +95,14 @@ export class RemoteAttachPicker {
             throw new Error(localize("no.pipetransport.useextendedremote", "Chosen debug configuration does not contain {0} or {1}", "pipeTransport", "useExtendedRemote"));
         }
 
+        const matchingProcesses: AttachItem[] | undefined = filterProcessItems(processes, config?.processFilter);
+        if (matchingProcesses?.length === 1) {
+            return matchingProcesses[0].id;
+        }
+        if (matchingProcesses && matchingProcesses.length > 1) {
+            processes = matchingProcesses;
+        }
+
         const attachPickOptions: vscode.QuickPickOptions = {
             matchOnDetail: true,
             matchOnDescription: true,

Extension/src/Debugger/processFilter.ts

@@ -0,0 +1,32 @@
+/* --------------------------------------------------------------------------------------------
+ * Copyright (c) Microsoft Corporation. All Rights Reserved.
+ * See 'LICENSE' in the project root for license information.
+ * ------------------------------------------------------------------------------------------ */
+
+import * as nls from 'vscode-nls';
+
+nls.config({ messageFormat: nls.MessageFormat.bundle, bundleFormat: nls.BundleFormat.standalone })();
+const localize: nls.LocalizeFunc = nls.loadMessageBundle();
+
+export interface ProcessFilterItem {
+    label?: string;
+    description?: string;
+    detail?: string;
+}
+
+export function filterProcessItems<T extends ProcessFilterItem>(items: T[], processFilter?: unknown): T[] | undefined {
+    // The value comes from launch.json, so it is not guaranteed to be a string.
+    if (typeof processFilter !== 'string' || !processFilter.trim()) {
+        return undefined;
+    }
+
+    let processRegex: RegExp;
+    try {
+        processRegex = new RegExp(processFilter);
+    } catch {
+        throw new Error(localize("invalid.processFilter.regex", "Invalid {0} regular expression: {1}", "processFilter", processFilter));
+    }
+
+    return items.filter((item: T) => [item.label, item.description, item.detail]
+        .some((value: string | undefined) => typeof value === "string" && processRegex.test(value)));
+}

Extension/test/unit/processFilter.test.ts

@@ -0,0 +1,61 @@
+/* --------------------------------------------------------------------------------------------
+ * Copyright (c) Microsoft Corporation. All Rights Reserved.
+ * See 'LICENSE' in the project root for license information.
+ * ------------------------------------------------------------------------------------------ */
+
+import { deepStrictEqual, strictEqual, throws } from 'assert';
+import { describe, it } from 'mocha';
+import { filterProcessItems } from '../../src/Debugger/processFilter';
+
+interface TestProcessItem {
+    label?: string;
+    description?: string;
+    detail?: string;
+    id: string;
+}
+
+describe('Remote attach process filter', () => {
+    const processes: TestProcessItem[] = [
+        { id: '101', label: 'root /usr/bin/my-daemon --serve', description: '101' },
+        { id: '102', label: 'root /usr/bin/other-service', description: '102', detail: 'worker' },
+        { id: '103', label: 'app /usr/bin/my-daemon --once', description: '103' }
+    ];
+
+    it('returns undefined when filter is empty', () => {
+        strictEqual(filterProcessItems(processes, ''), undefined);
+        strictEqual(filterProcessItems(processes, '   '), undefined);
+        strictEqual(filterProcessItems(processes, undefined), undefined);
+    });
+
+    it('returns undefined when filter is not a string', () => {
+        strictEqual(filterProcessItems(processes, 1234), undefined);
+        strictEqual(filterProcessItems(processes, true), undefined);
+        strictEqual(filterProcessItems(processes, {}), undefined);
+    });
+
+    it('matches by label and description and detail', () => {
+        deepStrictEqual(filterProcessItems(processes, 'other-service')?.map(p => p.id), ['102']);
+        deepStrictEqual(filterProcessItems(processes, '^101$')?.map(p => p.id), ['101']);
+        deepStrictEqual(filterProcessItems(processes, 'worker')?.map(p => p.id), ['102']);
+    });
+
+    it('preserves edge whitespace in the regular expression', () => {
+        deepStrictEqual(filterProcessItems(processes, '^root /usr/bin/my-daemon --serve ')?.map(p => p.id), []);
+    });
+
+    it('returns multiple matches when regex matches more than one process', () => {
+        deepStrictEqual(filterProcessItems(processes, 'my-daemon')?.map(p => p.id), ['101', '103']);
+    });
+
+    it('throws for invalid regular expression', () => {
+        throws(() => filterProcessItems(processes, '['), /Invalid processFilter regular expression/);
+    });
+
+    it('does not treat missing fields as empty strings', () => {
+        const items: TestProcessItem[] = [
+            { id: '201' }, // label, description, and detail are all missing
+            { id: '202', detail: '' } // detail is explicitly an empty string
+        ];
+        deepStrictEqual(filterProcessItems(items, '^$')?.map(p => p.id), ['202']);
+    });
+});

Extension/tools/OptionsSchema.json

@@ -923,6 +923,11 @@
             }
           ]
         },
+        "processFilter": {
+          "type": "string",
+          "description": "%c_cpp.debuggers.processFilter.description%",
+          "default": ""
+        },
         "filterStdout": {
           "type": "boolean",
           "description": "%c_cpp.debuggers.filterStdout.description%",