convert pid to a number so that lldb-dap can properly consume it

Author: matthewbastien

lldb/tools/lldb-dap/src-ts/commands/pick-process.ts

@@ -9,6 +9,10 @@ interface ProcessQuickPick extends vscode.QuickPickItem {
 /**
  * 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.
+ *
  * @returns The pid of the process as a string or undefined if cancelled.
  */
 export async function pickProcess(): Promise<string | undefined> {

lldb/tools/lldb-dap/src-ts/debug-configuration-provider.ts

@@ -0,0 +1,54 @@
+import * as vscode from "vscode";
+
+/**
+ * Converts the given value to an integer if it isn't already.
+ *
+ * If the value cannot be converted then this function will return undefined.
+ *
+ * @param value the value to to be converted
+ * @returns the integer value or undefined if unable to convert
+ */
+function convertToInteger(value: any): number | undefined {
+  let result: number | undefined;
+  switch (typeof value) {
+    case "number":
+      result = value;
+      break;
+    case "string":
+      result = Number(value);
+      break;
+    default:
+      return undefined;
+  }
+  if (!Number.isInteger(result)) {
+    return undefined;
+  }
+  return result;
+}
+
+/**
+ * A {@link vscode.DebugConfigurationProvider} used to resolve LLDB DAP debug configurations.
+ *
+ * Performs checks on the debug configuration before launching a debug session.
+ */
+export class LLDBDapConfigurationProvider
+  implements vscode.DebugConfigurationProvider
+{
+  resolveDebugConfigurationWithSubstitutedVariables(
+    _folder: vscode.WorkspaceFolder | undefined,
+    debugConfiguration: vscode.DebugConfiguration,
+  ): vscode.ProviderResult<vscode.DebugConfiguration> {
+    // Convert the "pid" option to a number if it is a string
+    if ("pid" in debugConfiguration) {
+      const pid = convertToInteger(debugConfiguration.pid);
+      if (pid === undefined) {
+        vscode.window.showErrorMessage(
+          "Invalid debug configuration: property 'pid' must either be an integer or a string containing an integer value.",
+        );
+        return null;
+      }
+      debugConfiguration.pid = pid;
+    }
+    return debugConfiguration;
+  }
+}

lldb/tools/lldb-dap/src-ts/extension.ts

@@ -6,6 +6,7 @@ import {
   isExecutable,
 } from "./debug-adapter-factory";
 import { DisposableContext } from "./disposable-context";
+import { LLDBDapConfigurationProvider } from "./debug-configuration-provider";
 
 /**
  * This class represents the extension and manages its life cycle. Other extensions
@@ -14,6 +15,12 @@ import { DisposableContext } from "./disposable-context";
 export class LLDBDapExtension extends DisposableContext {
   constructor() {
     super();
+    this.pushSubscription(
+      vscode.debug.registerDebugConfigurationProvider(
+        "lldb-dap",
+        new LLDBDapConfigurationProvider(),
+      ),
+    );
     this.pushSubscription(
       vscode.debug.registerDebugAdapterDescriptorFactory(
         "lldb-dap",