Add attach to process command (#604)

Author: adam-fowler

package.json

@@ -111,12 +111,12 @@
       },
       {
         "command": "swift.switchPlatform",
-        "title": "Select Target Platform",
+        "title": "Select Target Platform...",
         "category": "Swift"
       },
       {
         "command": "swift.selectXcodeDeveloperDir",
-        "title": "Select Xcode Developer Dir",
+        "title": "Select Xcode Developer Dir...",
         "category": "Swift"
       },
       {
@@ -148,6 +148,11 @@
         "command": "swift.toggleTestCoverage",
         "title": "Toggle Display of Test Coverage Results",
         "category": "Swift"
+      },
+      {
+        "command": "swift.attachDebugger",
+        "title": "Attach to Process...",
+        "category": "Swift"
       }
     ],
     "configuration": [
@@ -537,6 +542,10 @@
         {
           "command": "swift.runPluginTask",
           "when": "swift.packageHasPlugins"
+        },
+        {
+          "command": "swift.attachDebugger",
+          "when": "swift.lldbVSCodeAvailable"
         }
       ],
       "editor/context": [
@@ -866,8 +875,7 @@
               },
               "pid": {
                 "type": [
-                  "number",
-                  "string"
+                  "number"
                 ],
                 "description": "System process ID to attach to."
               },

src/commands.ts

@@ -21,11 +21,12 @@ import { createSwiftTask, SwiftTaskProvider } from "./SwiftTaskProvider";
 import { FolderContext } from "./FolderContext";
 import { PackageNode } from "./ui/PackageDependencyProvider";
 import { withQuickPick } from "./ui/QuickPick";
-import { execSwift } from "./utilities/utilities";
+import { execSwift, getErrorDescription } from "./utilities/utilities";
 import { Version } from "./utilities/version";
 import { DarwinCompatibleTarget, SwiftToolchain } from "./toolchain/toolchain";
 import { debugSnippet, runSnippet } from "./SwiftSnippets";
 import { debugLaunchConfig, getLaunchConfiguration } from "./debugger/launch";
+import { execFile } from "./utilities/utilities";
 
 /**
  * References:
@@ -620,6 +621,39 @@ function toggleTestCoverageDisplay(workspaceContext: WorkspaceContext) {
     workspaceContext.toggleTestCoverageDisplay();
 }
 
+async function attachDebugger(workspaceContext: WorkspaceContext) {
+    // use LLDB to get list of processes
+    const lldb = workspaceContext.toolchain.getToolchainExecutable("lldb");
+    try {
+        const { stdout } = await execFile(lldb, [
+            "--batch",
+            "--no-lldbinit",
+            "--one-line",
+            "platform process list --show-args --all-users",
+        ]);
+        const entries = stdout.split("\n");
+        const processPickItems = 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 [];
+            }
+        });
+        await withQuickPick("Select Process", processPickItems, async selected => {
+            const debugConfig: vscode.DebugConfiguration = {
+                type: "swift-lldb",
+                request: "attach",
+                name: "Attach",
+                pid: selected.pid,
+            };
+            await vscode.debug.startDebugging(undefined, debugConfig);
+        });
+    } catch (error) {
+        vscode.window.showErrorMessage(`Failed to run LLDB: ${getErrorDescription(error)}`);
+    }
+}
+
 function updateAfterError(result: boolean, folderContext: FolderContext) {
     const triggerResolvedUpdatedEvent = folderContext.hasResolveErrors;
     // set has resolve errors flag
@@ -689,6 +723,7 @@ export function register(ctx: WorkspaceContext) {
         }),
         vscode.commands.registerCommand("swift.selectXcodeDeveloperDir", () =>
             selectXcodeDeveloperDir()
-        )
+        ),
+        vscode.commands.registerCommand("swift.attachDebugger", () => attachDebugger(ctx))
     );
 }

src/contextKeys.ts

@@ -59,6 +59,13 @@ const contextKeys = {
     set fileIsSnippet(value: boolean) {
         vscode.commands.executeCommand("setContext", "swift.fileIsSnippet", value);
     },
+
+    /**
+     * Whether current active file is a Snippet
+     */
+    set lldbVSCodeAvailable(value: boolean) {
+        vscode.commands.executeCommand("setContext", "swift.lldbVSCodeAvailable", value);
+    },
 };
 
 export default contextKeys;

src/debugger/debugAdapter.ts

@@ -16,12 +16,13 @@ import * as vscode from "vscode";
 import * as fs from "fs";
 import { WorkspaceContext } from "../WorkspaceContext";
 import configuration from "../configuration";
+import contextKeys from "../contextKeys";
 
 /**
  * Class managing which debug adapter we are using. Will only setup lldb-vscode if it is available.
  */
 export class DebugAdapter {
-    static debugAdapaterExists = false;
+    private static debugAdapaterExists = false;
 
     /** Debug adapter name */
     static get adapterName(): string {
@@ -54,9 +55,11 @@ export class DebugAdapter {
             }
             workspace.outputChannel.log(`Failed to find ${lldbDebugAdapterPath}`);
             this.debugAdapaterExists = false;
+            contextKeys.lldbVSCodeAvailable = false;
             return false;
         }
         this.debugAdapaterExists = true;
+        contextKeys.lldbVSCodeAvailable = true;
         return true;
     }