check constraints when registering debugProvider

src/vs/vscode.proposed.d.ts

@@ -551,7 +551,8 @@ declare module 'vscode' {
 		 *      }
 		 * 		return executable;
 		 *   }
-		 * Registering more than one provideDebugAdapter for a type results in an error.
+		 * An extension is only allowed to register a DebugConfigurationProvider with a provideDebugAdapter method if the extension defines the debug type. Otherwise an error is thrown.
+		 * Registering more than one DebugConfigurationProvider with a provideDebugAdapter method for a type results in an error.
 		 * @param session The [debug session](#DebugSession) for which the debug adapter will be used.
 		 * @param folder The workspace folder from which the configuration originates from or undefined for a folderless setup.
 		 * @param executable The debug adapter's executable information as specified in the package.json (or undefined if no such information exists).
@@ -563,11 +564,6 @@ declare module 'vscode' {
 
 		/**
 		 * Deprecated, use DebugConfigurationProvider.provideDebugAdapter instead.
-		 * This optional method is called just before a debug adapter is started to determine its executable path and arguments.
-		 * Registering more than one debugAdapterExecutable for a type results in an error.
-		 * @param folder The workspace folder from which the configuration originates from or undefined for a folderless setup.
-		 * @param token A cancellation token.
-		 * @return a [debug adapter's executable and optional arguments](#DebugAdapterExecutable) or undefined.
 		 * @deprecated Use DebugConfigurationProvider.provideDebugAdapter instead
 		 */
 		debugAdapterExecutable?(folder: WorkspaceFolder | undefined, token?: CancellationToken): ProviderResult<DebugAdapterExecutable>;

src/vs/workbench/api/node/extHost.api.impl.ts

@@ -656,7 +656,7 @@ export function createApiFactory(
 				return extHostDebugService.onDidChangeBreakpoints(listener, thisArgs, disposables);
 			},
 			registerDebugConfigurationProvider(debugType: string, provider: vscode.DebugConfigurationProvider) {
-				return extHostDebugService.registerDebugConfigurationProvider(debugType, provider);
+				return extHostDebugService.registerDebugConfigurationProvider(extension, debugType, provider);
 			},
 			startDebugging(folder: vscode.WorkspaceFolder | undefined, nameOrConfig: string | vscode.DebugConfiguration) {
 				return extHostDebugService.startDebugging(folder, nameOrConfig);

src/vs/workbench/api/node/extHostDebugService.ts

@@ -33,6 +33,7 @@ import { IDisposable } from 'vs/base/common/lifecycle';
 import { IConfigurationResolverService } from 'vs/workbench/services/configurationResolver/common/configurationResolver';
 import { CancellationToken } from 'vs/base/common/cancellation';
 import { ExtHostCommands } from 'vs/workbench/api/node/extHostCommands';
+import { IExtensionDescription } from 'vs/workbench/services/extensions/common/extensions';
 
 
 export class ExtHostDebugService implements ExtHostDebugServiceShape {
@@ -116,7 +117,7 @@ export class ExtHostDebugService implements ExtHostDebugServiceShape {
 				const debuggers = <IDebuggerContribution[]>ed.contributes['debuggers'];
 				if (debuggers && debuggers.length > 0) {
 					for (const dbg of debuggers) {
-						// only debugger contributions with a "label" are considered a "main" debugger contribution
+						// only debugger contributions with a "label" are considered a "defining" debugger contribution
 						if (dbg.type && dbg.label) {
 							debugTypes.push(dbg.type);
 							if (dbg.adapterExecutableCommand) {
@@ -239,14 +240,30 @@ export class ExtHostDebugService implements ExtHostDebugServiceShape {
 		return this._debugServiceProxy.$startDebugging(folder ? folder.uri : undefined, nameOrConfig);
 	}
 
-	public registerDebugConfigurationProvider(type: string, provider: vscode.DebugConfigurationProvider): vscode.Disposable {
+	public registerDebugConfigurationProvider(extension: IExtensionDescription, type: string, provider: vscode.DebugConfigurationProvider): vscode.Disposable {
+
 		if (!provider) {
 			return new Disposable(() => { });
 		}
 
+		// if a provider has a provideDebugAdapter method, we check the constraints specified in the API doc
+		if (provider.provideDebugAdapter) {
+
+			// a provider with this method can only be registered in the extension that contributes the debugger
+			if (!this.definesDebugType(extension, type)) {
+				throw new Error(`method 'provideDebugAdapter' must only be called from the extension that defines the '${type}' debugger.`);
+			}
+
+			// make sure that only one provider for this type is registered
+			if (this._providerByType.has(type)) {
+				throw new Error(`a provider with method 'provideDebugAdapter' can only be registered once per a type.`);
+			} else {
+				this._providerByType.set(type, provider);
+			}
+		}
+
 		let handle = this._handleCounter++;
 		this._providerByHandle.set(handle, provider);
-		this._providerByType.set(type, provider);
 
 		this._debugServiceProxy.$registerDebugConfigurationProvider(type,
 			!!provider.provideDebugConfigurations,
@@ -255,7 +272,7 @@ export class ExtHostDebugService implements ExtHostDebugServiceShape {
 
 		return new Disposable(() => {
 			this._providerByHandle.delete(handle);
-			this._providerByType.delete(type);	// TODO@AW support more than one
+			this._providerByType.delete(type);
 			this._debugServiceProxy.$unregisterDebugConfigurationProvider(handle);
 		});
 	}
@@ -520,6 +537,23 @@ export class ExtHostDebugService implements ExtHostDebugServiceShape {
 
 	// private & dto helpers
 
+	private definesDebugType(ed: IExtensionDescription, type: string) {
+		if (ed.contributes) {
+			const debuggers = <IDebuggerContribution[]>ed.contributes['debuggers'];
+			if (debuggers && debuggers.length > 0) {
+				for (const dbg of debuggers) {
+					// only debugger contributions with a "label" are considered a "defining" debugger contribution
+					if (dbg.label && dbg.type) {
+						if (dbg.type === type) {
+							return true;
+						}
+					}
+				}
+			}
+		}
+		return false;
+	}
+
 	private getAdapterDescriptor(debugConfigProvider, sessionDto: IDebugSessionDto, folderUri: UriComponents | undefined, config: vscode.DebugConfiguration): Thenable<vscode.DebugAdapterDescriptor> {
 
 		// a "debugServer" attribute in the launch config takes precedence