Add snippets for debug configurations (#1411)

Author: matthewbastien

package.json

@@ -271,6 +271,11 @@
         "title": "Run Until Failure...",
         "category": "Swift"
       },
+      {
+        "command": "swift.pickProcess",
+        "title": "Pick Process...",
+        "category": "Swift"
+      },
       {
         "command": "swift.runAllTestsParallel",
         "title": "Run Tests in Parallel",
@@ -957,6 +962,10 @@
           "command": "swift.reindexProject",
           "when": "swift.supportsReindexing"
         },
+        {
+          "command": "swift.pickProcess",
+          "when": "false"
+        },
         {
           "command": "swift.runAllTestsParallel",
           "when": "swift.isActivated"
@@ -1358,6 +1367,9 @@
       {
         "type": "swift",
         "label": "Swift Debugger",
+        "variables": {
+          "pickProcess": "swift.pickProcess"
+        },
         "configurationAttributes": {
           "launch": {
             "required": [
@@ -1490,6 +1502,7 @@
               },
               "pid": {
                 "type": [
+                  "string",
                   "number"
                 ],
                 "description": "System process ID to attach to."
@@ -1560,7 +1573,42 @@
               }
             }
           }
-        }
+        },
+        "configurationSnippets": [
+          {
+            "label": "Swift: Launch",
+            "description": "",
+            "body": {
+              "type": "swift",
+              "request": "launch",
+              "name": "${2:Launch Swift Executable}",
+              "program": "^\"\\${workspaceRoot}/.build/debug/${1:<program>}\"",
+              "args": [],
+              "env": {},
+              "cwd": "^\"\\${workspaceRoot}\""
+            }
+          },
+          {
+            "label": "Swift: Attach to Process",
+            "description": "",
+            "body": {
+              "type": "swift",
+              "request": "attach",
+              "name": "${1:Attach to Swift Executable}",
+              "pid": "^\"\\${command:pickProcess}\""
+            }
+          },
+          {
+            "label": "Swift: Attach",
+            "description": "",
+            "body": {
+              "type": "swift",
+              "request": "attach",
+              "name": "${2:Attach to Swift Executable}",
+              "program": "^\"\\${workspaceRoot}/.build/debug/${1:<program>}\""
+            }
+          }
+        ]
       }
     ]
   },

src/commands.ts

@@ -43,6 +43,7 @@ import { runAllTests } from "./commands/runAllTests";
 import { updateDependenciesViewList } from "./commands/dependencies/updateDepViewList";
 import { runTask } from "./commands/runTask";
 import { TestKind } from "./TestExplorer/TestKind";
+import { pickProcess } from "./commands/pickProcess";
 
 /**
  * References:
@@ -65,6 +66,9 @@ export function registerToolchainCommands(
         vscode.commands.registerCommand("swift.selectToolchain", () =>
             showToolchainSelectionQuickPick(toolchain)
         ),
+        vscode.commands.registerCommand("swift.pickProcess", configuration =>
+            pickProcess(configuration)
+        ),
     ];
 }
 
@@ -169,7 +173,7 @@ export function register(ctx: WorkspaceContext): vscode.Disposable[] {
                 return openInExternalEditor(item);
             }
         }),
-        vscode.commands.registerCommand("swift.attachDebugger", () => attachDebugger(ctx)),
+        vscode.commands.registerCommand("swift.attachDebugger", attachDebugger),
         vscode.commands.registerCommand("swift.clearDiagnosticsCollection", () =>
             ctx.diagnostics.clear()
         ),

src/commands/attachDebugger.ts

@@ -13,8 +13,6 @@
 //===----------------------------------------------------------------------===//
 
 import * as vscode from "vscode";
-import { WorkspaceContext } from "../WorkspaceContext";
-import { getLldbProcess } from "../debugger/lldb";
 import { SWIFT_LAUNCH_CONFIG_TYPE } from "../debugger/debugAdapter";
 
 /**
@@ -29,20 +27,11 @@ import { SWIFT_LAUNCH_CONFIG_TYPE } from "../debugger/debugAdapter";
  *
  * @throws Will display an error message if no processes are available, or if the debugger fails to attach to the selected process.
  */
-export async function attachDebugger(ctx: WorkspaceContext) {
-    const processPickItems = await getLldbProcess(ctx);
-    if (processPickItems !== undefined) {
-        const picked = await vscode.window.showQuickPick(processPickItems, {
-            placeHolder: "Select Process",
-        });
-        if (picked) {
-            const debugConfig: vscode.DebugConfiguration = {
-                type: SWIFT_LAUNCH_CONFIG_TYPE,
-                request: "attach",
-                name: "Attach",
-                pid: picked.pid,
-            };
-            await vscode.debug.startDebugging(undefined, debugConfig);
-        }
-    }
+export async function attachDebugger() {
+    await vscode.debug.startDebugging(undefined, {
+        type: SWIFT_LAUNCH_CONFIG_TYPE,
+        request: "attach",
+        name: "Attach",
+        pid: "${command:pickProcess}",
+    });
 }

src/commands/pickProcess.ts

@@ -0,0 +1,79 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the VS Code Swift open source project
+//
+// Copyright (c) 2025 the VS Code Swift project authors
+// Licensed under Apache License v2.0
+//
+// See LICENSE.txt for license information
+// See CONTRIBUTORS.txt for the list of VS Code Swift project authors
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+//===----------------------------------------------------------------------===//
+
+import * as path from "path";
+import * as vscode from "vscode";
+import { createProcessList } from "../process-list";
+
+interface ProcessQuickPick extends vscode.QuickPickItem {
+    processId?: number;
+}
+
+/**
+ * Prompts the user to select a running process.
+ *
+ * The return value must be a string so that it is compatible with VS Code's
+ * string substitution infrastructure. The value will eventually be converted
+ * to a number by the debug configuration provider.
+ *
+ * @param configuration The related debug configuration, if any
+ * @returns The pid of the process as a string or undefined if cancelled.
+ */
+export async function pickProcess(
+    configuration?: vscode.DebugConfiguration
+): Promise<string | undefined> {
+    const processList = createProcessList();
+    const selectedProcess = await vscode.window.showQuickPick<ProcessQuickPick>(
+        processList.listAllProcesses().then((processes): ProcessQuickPick[] => {
+            // Sort by start date in descending order
+            processes.sort((a, b) => b.start - a.start);
+            // Filter by program if requested
+            if (typeof configuration?.program === "string") {
+                const program = configuration.program;
+                const programBaseName = path.basename(program);
+                processes = processes
+                    .filter(proc => path.basename(proc.command) === programBaseName)
+                    .sort((a, b) => {
+                        // Bring exact command matches to the top
+                        const aIsExactMatch = a.command === program ? 1 : 0;
+                        const bIsExactMatch = b.command === program ? 1 : 0;
+                        return bIsExactMatch - aIsExactMatch;
+                    });
+                // Show a better message if all processes were filtered out
+                if (processes.length === 0) {
+                    return [
+                        {
+                            label: "No processes matched the debug configuration's program",
+                        },
+                    ];
+                }
+            }
+            // Convert to a QuickPickItem
+            return processes.map(proc => {
+                return {
+                    processId: proc.id,
+                    label: path.basename(proc.command),
+                    description: proc.id.toString(),
+                    detail: proc.arguments,
+                } satisfies ProcessQuickPick;
+            });
+        }),
+        {
+            placeHolder: "Select a process to attach the debugger to",
+            matchOnDetail: true,
+            matchOnDescription: true,
+        }
+    );
+    return selectedProcess?.processId?.toString();
+}

src/debugger/debugAdapterFactory.ts

@@ -74,7 +74,7 @@ export class LLDBDebugConfigurationProvider implements vscode.DebugConfiguration
         private outputChannel: SwiftOutputChannel
     ) {}
 
-    async resolveDebugConfiguration(
+    async resolveDebugConfigurationWithSubstitutedVariables(
         _folder: vscode.WorkspaceFolder | undefined,
         launchConfig: vscode.DebugConfiguration
     ): Promise<vscode.DebugConfiguration | undefined | null> {

src/debugger/lldb.ts

@@ -17,9 +17,7 @@
 
 import * as path from "path";
 import * as fs from "fs/promises";
-import * as vscode from "vscode";
-import { WorkspaceContext } from "../WorkspaceContext";
-import { execFile, getErrorDescription } from "../utilities/utilities";
+import { execFile } from "../utilities/utilities";
 import { Result } from "../utilities/result";
 import { SwiftToolchain } from "../toolchain/toolchain";
 
@@ -114,46 +112,3 @@ export async function findFileByPattern(path: string, pattern: RegExp): Promise<
     }
     return null;
 }
-
-/**
- * Retrieves a list of LLDB processes from the system using LLDB.
- *
- * This function executes an LLDB command to list all processes on the system,
- * including their arguments, and returns them in an array of objects where each
- * object contains the `pid` and a `label` describing the process.
- *
- * @param {WorkspaceContext} ctx - The workspace context, which includes the toolchain needed to run LLDB.
- * @returns {Promise<Array<{ pid: number; label: string }> | undefined>}
- * A promise that resolves to an array of processes, where each process is represented by an object with a `pid` and a `label`.
- * If an error occurs or no processes are found, it returns `undefined`.
- *
- * @throws Will display an error message in VS Code if the LLDB command fails.
- */
-export async function getLldbProcess(
-    ctx: WorkspaceContext
-): Promise<Array<{ pid: number; label: string }> | undefined> {
-    try {
-        // use LLDB to get list of processes
-        const lldb = await ctx.toolchain.getLLDB();
-        const { stdout } = await execFile(lldb, [
-            "--batch",
-            "--no-lldbinit",
-            "--one-line",
-            "platform process list --show-args --all-users",
-        ]);
-        const entries = stdout.split("\n");
-        const processes = entries.flatMap(line => {
-            const match = /^(\d+)\s+\d+\s+\S+\s+\S+\s+(.+)$/.exec(line);
-            if (match) {
-                return [{ pid: parseInt(match[1]), label: `${match[1]}: ${match[2]}` }];
-            } else {
-                return [];
-            }
-        });
-        return processes;
-    } catch (error) {
-        const errorMessage = `Failed to run LLDB: ${getErrorDescription(error)}`;
-        ctx.outputChannel.log(errorMessage);
-        vscode.window.showErrorMessage(errorMessage);
-    }
-}

src/process-list/BaseProcessList.ts

@@ -0,0 +1,55 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the VS Code Swift open source project
+//
+// Copyright (c) 2025 the VS Code Swift project authors
+// Licensed under Apache License v2.0
+//
+// See LICENSE.txt for license information
+// See CONTRIBUTORS.txt for the list of VS Code Swift project authors
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+//===----------------------------------------------------------------------===//
+
+import * as util from "util";
+import * as child_process from "child_process";
+import { Process, ProcessList } from ".";
+
+const exec = util.promisify(child_process.execFile);
+
+/** Parses process information from a given line of process output. */
+export type ProcessListParser = (line: string) => Process | undefined;
+
+/**
+ * Implements common behavior between the different {@link ProcessList} implementations.
+ */
+export abstract class BaseProcessList implements ProcessList {
+    /**
+     * Get the command responsible for collecting all processes on the system.
+     */
+    protected abstract getCommand(): string;
+
+    /**
+     * Get the list of arguments used to launch the command.
+     */
+    protected abstract getCommandArguments(): string[];
+
+    /**
+     * Create a new parser that can read the process information from stdout of the process
+     * spawned by {@link spawnProcess spawnProcess()}.
+     */
+    protected abstract createParser(): ProcessListParser;
+
+    async listAllProcesses(): Promise<Process[]> {
+        const execCommand = exec(this.getCommand(), this.getCommandArguments());
+        const parser = this.createParser();
+        return (await execCommand).stdout.split("\n").flatMap(line => {
+            const process = parser(line.toString());
+            if (!process || process.id === execCommand.child.pid) {
+                return [];
+            }
+            return [process];
+        });
+    }
+}