feat: make sourcemap toggle work for wasm/wat, add disable (#1810)

CHANGELOG.md

@@ -4,6 +4,7 @@ This changelog records changes to stable releases since 1.50.2. "TBA" changes he
 
 ## Nightly (only)
 
+- feat: enable DWARF-based WebAssembly debugging ([#1789](https://github.com/microsoft/vscode-js-debug/issues/1789))
 - feat: show class names of methods in call stack view ([#1770](https://github.com/microsoft/vscode-js-debug/issues/1770))
 - fix: edge devtools incorrectly ask for local forwarding ([vscode#193110](https://github.com/microsoft/vscode/issues/193110))
 

package.nls.json

@@ -2,6 +2,7 @@
   "add.browser.breakpoint": "Add Browser Breakpoint",
   "attach.node.process": "Attach to Node Process",
   "base.cascadeTerminateToConfigurations.label": "A list of debug sessions which, when this debug session is terminated, will also be stopped.",
+  "base.enableDWARF.label": "Toggles whether the debugger will try to read DWARF debug symbols from WebAssembly, which can be resource intensive. Requires the `ms-vscode.wasm-dwarf-debugging` extension to function.",
   "browser.address.description": "IP address or hostname the debugged browser is listening on.",
   "browser.attach.port.description": "Port to use to remote debugging the browser, given as `--remote-debugging-port` when launching the browser.",
   "browser.baseUrl.description": "Base URL to resolve paths baseUrl. baseURL is trimmed when mapping URLs to the files on disk. Defaults to the launch URL domain.",
@@ -203,4 +204,4 @@
   "trace.logFile.description": "Configures where on disk logs are written.",
   "trace.stdio.description": "Whether to return trace data from the launched application or browser.",
   "workspaceTrust.description": "Trust is required to debug code in this workspace."
-}
+}

src/adapter/dwarf/wasmSymbolProvider.ts

@@ -13,6 +13,7 @@ import { IDisposable } from '../../common/disposable';
 import { ILogger, LogTag } from '../../common/logging';
 import { flatten, once } from '../../common/objUtils';
 import { Base0Position, IPosition, Range } from '../../common/positions';
+import { AnyLaunchConfiguration } from '../../configuration';
 import { StepDirection } from '../pause';
 import { getSourceSuffix } from '../templates';
 import { IDwarfModuleProvider } from './dwarfModuleProvider';
@@ -35,12 +36,17 @@ export class WasmSymbolProvider implements IWasmSymbolProvider, IDisposable {
     @inject(IDwarfModuleProvider) private readonly dwarf: IDwarfModuleProvider,
     @inject(ICdpApi) private readonly cdp: Cdp.Api,
     @inject(ILogger) private readonly logger: ILogger,
+    @inject(AnyLaunchConfiguration) private readonly launchConfig: AnyLaunchConfiguration,
   ) {}
 
   public async loadWasmSymbols(script: Cdp.Debugger.ScriptParsedEvent): Promise<IWasmSymbols> {
+    if (!this.launchConfig.enableDWARF) {
+      return this.defaultSymbols(script);
+    }
+
     const rpc = await this.getWorker();
     if (!rpc) {
-      const syms = new DecompiledWasmSymbols(script, this.cdp, []);
+      const syms = this.defaultSymbols(script);
       // disassembly is a good signal for a prompt, since that means a user
       // will have stepped into and be looking at webassembly code.
       syms.onDidDisassemble = this.doPrompt;
@@ -60,12 +66,12 @@ export class WasmSymbolProvider implements IWasmSymbolProvider, IDisposable {
             : undefined,
       });
     } catch {
-      return new DecompiledWasmSymbols(script, this.cdp, []);
+      return this.defaultSymbols(script);
     }
 
     if (!(result instanceof Array) || result.length === 0) {
       rpc.sendMessage('removeRawModule', moduleId); // no await necessary
-      return new DecompiledWasmSymbols(script, this.cdp, []);
+      return this.defaultSymbols(script);
     }
 
     this.logger.info(LogTag.SourceMapParsing, 'parsed files from wasm', { files: result });
@@ -79,6 +85,10 @@ export class WasmSymbolProvider implements IWasmSymbolProvider, IDisposable {
     this.worker = undefined;
   }
 
+  private defaultSymbols(script: Cdp.Debugger.ScriptParsedEvent) {
+    return new DecompiledWasmSymbols(script, this.cdp, []);
+  }
+
   private async getBytecode(scriptId: string) {
     const source = await this.cdp.Debugger.getScriptSource({ scriptId });
     const bytecode = source?.bytecode;
@@ -178,6 +188,16 @@ export interface IWasmSymbols extends IDisposable {
     compiledPosition: IPosition,
   ): Promise<{ url: string; position: IPosition } | undefined>;
 
+  /**
+   * Gets the position in the disassembly for the given position in compiled code.
+   *
+   * Following CDP semantics, it assumes the column is being the byte offset
+   * in webassembly. However, we encode the inline frame index in the line.
+   */
+  disassembledPositionFor(
+    compiledPosition: IPosition,
+  ): Promise<{ url: string; position: IPosition } | undefined>;
+
   /**
    * Gets the compiled position for the given position in source code.
    *
@@ -247,7 +267,14 @@ class DecompiledWasmSymbols implements IWasmSymbols {
   }
 
   /** @inheritdoc */
-  public async originalPositionFor(
+  public originalPositionFor(
+    compiledPosition: IPosition,
+  ): Promise<{ url: string; position: IPosition } | undefined> {
+    return this.disassembledPositionFor(compiledPosition);
+  }
+
+  /** @inheritdoc */
+  public async disassembledPositionFor(
     compiledPosition: IPosition,
   ): Promise<{ url: string; position: IPosition } | undefined> {
     const { byteOffsetsOfLines } = await this.doDisassemble();
@@ -385,6 +412,10 @@ class WasmSymbols extends DecompiledWasmSymbols {
     sourceUrl: string,
     sourcePosition: IPosition,
   ): Promise<IPosition[]> {
+    if (sourceUrl === this.decompiledUrl) {
+      return super.compiledPositionFor(sourceUrl, sourcePosition);
+    }
+
     const { lineNumber, columnNumber } = sourcePosition.base0;
     const locations = await this.rpc.sendMessage('sourceLocationToRawLocation', {
       lineNumber,

src/adapter/source.ts

@@ -510,6 +510,11 @@ export const isSourceWithWasm = (
 ): source is ISourceWithMap<IWasmLocationProvider> =>
   isSourceWithMap(source) && source.sourceMap.type === SourceLocationType.WasmSymbols;
 
+export const isWasmSymbols = (
+  source: SourceMap | IWasmSymbols | undefined,
+): source is IWasmSymbols =>
+  !!source && typeof (source as IWasmSymbols).getDisassembly === 'function';
+
 export type ContentGetter = () => Promise<string | undefined>;
 export type LineColumn = { lineNumber: number; columnNumber: number }; // 1-based
 

src/adapter/sourceContainer.ts

@@ -40,6 +40,7 @@ import {
   isSourceWithMap,
   isSourceWithSourceMap,
   isSourceWithWasm,
+  isWasmSymbols,
   rawToUiOffset,
   uiToRawOffset,
 } from './source';
@@ -332,31 +333,23 @@ export class SourceContainer {
    * This method returns a "preferred" location. This usually means going
    * through a source map and showing the source map source instead of a
    * compiled one. We use timeout to avoid waiting for the source map for too long.
+   *
+   * Similar to {@link getSourceMapUiLocations}, except it only returns the
+   * single preferred location.
    */
   public async preferredUiLocation(uiLocation: IUiLocation): Promise<IPreferredUiLocation> {
     let isMapped = false;
     let unmappedReason: UnmappedReason | undefined = UnmappedReason.CannotMap;
-    if (this._doSourceMappedStepping) {
-      while (true) {
-        if (!isSourceWithMap(uiLocation.source)) {
-          break;
-        }
-
-        const map = await SourceLocationProvider.waitForValueWithTimeout(
-          uiLocation.source.sourceMap,
-          this._sourceMapTimeouts.resolveLocation,
-        );
-        if (!map) return { ...uiLocation, isMapped, unmappedReason };
-        const sourceMapped = await this._sourceMappedUiLocation(uiLocation, map);
-        if (!isUiLocation(sourceMapped)) {
-          unmappedReason = isMapped ? undefined : sourceMapped;
-          break;
-        }
-
-        uiLocation = sourceMapped;
-        isMapped = true;
-        unmappedReason = undefined;
+    while (true) {
+      const next = await this._originalPositionFor(uiLocation);
+      if (!isUiLocation(next)) {
+        unmappedReason = isMapped ? undefined : next;
+        break;
       }
+
+      uiLocation = next;
+      isMapped = true;
+      unmappedReason = undefined;
     }
 
     return { ...uiLocation, isMapped, unmappedReason };
@@ -407,24 +400,65 @@ export class SourceContainer {
 
   /**
    * Returns all UI locations the given location maps to.
+   *
+   * Similar to {@link preferredUiLocation}, except it returns all positions,
+   * not just one.
    */
   private async getSourceMapUiLocations(uiLocation: IUiLocation): Promise<IUiLocation[]> {
-    if (!isSourceWithMap(uiLocation.source) || !this._doSourceMappedStepping) return [];
+    const sourceMapUiLocation = await this._originalPositionFor(uiLocation);
+    if (!isUiLocation(sourceMapUiLocation)) {
+      return [];
+    }
+
+    const r = await this.getSourceMapUiLocations(sourceMapUiLocation);
+    r.push(sourceMapUiLocation);
+    return r;
+  }
+
+  /**
+   * Gets the compiled position for a single UI location. Is aware of whether
+   * source map stepping is enabled.
+   */
+  private async _originalPositionFor(uiLocation: IUiLocation) {
+    if (!isSourceWithMap(uiLocation.source)) {
+      return UnmappedReason.HasNoMap;
+    }
+
     const map = await SourceLocationProvider.waitForValueWithTimeout(
       uiLocation.source.sourceMap,
       this._sourceMapTimeouts.resolveLocation,
     );
+    if (!map) {
+      return UnmappedReason.MapLoadingFailed;
+    }
 
-    if (!map) return [];
-    const sourceMapUiLocation = await this._sourceMappedUiLocation(uiLocation, map);
-    if (!isUiLocation(sourceMapUiLocation)) return [];
+    if (this._doSourceMappedStepping) {
+      return this._originalPositionForMap(uiLocation, map);
+    }
 
-    const r = await this.getSourceMapUiLocations(sourceMapUiLocation);
-    r.push(sourceMapUiLocation);
-    return r;
+    if (isWasmSymbols(map)) {
+      const l = await map.disassembledPositionFor(
+        new Base1Position(uiLocation.lineNumber, uiLocation.columnNumber),
+      );
+      const mapped = l && uiLocation.source.sourceMap.sourceByUrl.get(l.url);
+      if (mapped) {
+        return mapped
+          ? {
+              columnNumber: l.position.base1.lineNumber,
+              lineNumber: l.position.base1.lineNumber,
+              source: mapped,
+            }
+          : UnmappedReason.MapPositionMissing;
+      }
+    }
+
+    return UnmappedReason.MapDisabled;
   }
 
-  private async _sourceMappedUiLocation(
+  /**
+   * Looks up the given location in the sourcemap.
+   */
+  private async _originalPositionForMap(
     uiLocation: IUiLocation,
     map: SourceMap | IWasmSymbols,
   ): Promise<IUiLocation | UnmappedReason> {
@@ -529,7 +563,7 @@ export class SourceContainer {
     sourceMap: SourceMap | IWasmSymbols,
     uiLocation: LineColumn,
   ): Promise<{ url: string; position: IPosition } | undefined> {
-    if ('decompiledUrl' in sourceMap) {
+    if (isWasmSymbols(sourceMap)) {
       return await sourceMap.originalPositionFor(
         new Base1Position(uiLocation.lineNumber, uiLocation.columnNumber),
       );

src/build/generate-contributions.ts

@@ -295,6 +295,11 @@ const baseConfigurationAttributes: ConfigurationAttributes<IBaseConfiguration> =
     default: [],
     description: refString('base.cascadeTerminateToConfigurations.label'),
   },
+  enableDWARF: {
+    type: 'boolean',
+    default: true,
+    markdownDescription: refString('base.enableDWARF.label'),
+  },
 };
 
 /**

src/configuration.ts

@@ -158,6 +158,13 @@ export interface IBaseConfiguration extends IMandatedConfiguration {
    */
   cascadeTerminateToConfigurations: string[];
 
+  /**
+   * Toggles whether the debugger will try to read DWARF debug symbols from
+   * WebAssembly, which can be resource intensive. Requires the
+   * `ms-vscode.wasm-dwarf-debugging` extension to function.
+   */
+  enableDWARF: boolean;
+
   /**
    * The value of the ${workspaceFolder} variable
    */
@@ -814,6 +821,7 @@ export const baseDefaults: IBaseConfiguration = {
   sourceMapPathOverrides: defaultSourceMapPathOverrides('${workspaceFolder}'),
   enableContentValidation: true,
   cascadeTerminateToConfigurations: [],
+  enableDWARF: true,
   // Should always be determined upstream;
   __workspaceFolder: '',
   __remoteFilePrefix: undefined,