Use wasm to demangle C++ and Rust

src/lib/demangle.test.ts

@@ -0,0 +1,23 @@
+import {loadDemangling} from './demangle'
+
+test('demangle', async () => {
+  const demangle = await loadDemangling()
+
+  expect(demangle('a')).toBe('a')
+  expect(demangle('someUnobfuscatedFunction')).toBe('someUnobfuscatedFunction')
+
+  // C++ mangling
+  expect(demangle('__ZNK7Support6ColorFeqERKS0_')).toBe(
+    'Support::ColorF::operator==(Support::ColorF const&) const',
+  )
+  // Running a second time to test the cache
+  expect(demangle('__ZNK7Support6ColorFeqERKS0_')).toBe(
+    'Support::ColorF::operator==(Support::ColorF const&) const',
+  )
+
+  // Rust v0 mangling
+  expect(demangle('_RNvCskwGfYPst2Cb_3foo16example_function')).toBe('foo::example_function')
+
+  // Rust legacy mangling
+  expect(demangle('_ZN3std2fs8Metadata7created17h8df207f105c5d474E')).toBe('std::fs::Metadata::created::h8df207f105c5d474')
+})

src/lib/demangle.ts

@@ -0,0 +1,25 @@
+import createWasmDemangleModule from "./demangle.wasm";
+
+const cache = new Map<string, string>()
+
+export async function loadDemangling(): Promise<(name: string) => string> {
+  // This function converts a mangled C++ name such as "__ZNK7Support6ColorFeqERKS0_"
+  // into a human-readable symbol (in this case "Support::ColorF::==(Support::ColorF&)")
+  const wasmDemangleModule = await createWasmDemangleModule();
+  return cached(wasmDemangleModule.wasm_demangle);
+}
+
+function cached(demangle: (name: string) => string): (name: string) => string {
+  return (name: string): string => {
+    let result = cache.get(name)
+    if (result !== undefined) {
+      name = result
+    } else {
+      result = demangle(name)
+      result = result === '' ? name : result
+      cache.set(name, result)
+      name = result
+    }
+    return name
+  }
+}

src/lib/demangle.wasm.d.ts

@@ -0,0 +1,5 @@
+interface WasmDemangleModule {
+    wasm_demangle(mangled: string): string
+}
+
+export default function ModuleFactory(options?: unknown): Promise<WasmDemangleModule>;

src/lib/profile.ts

@@ -1,7 +1,6 @@
 import {lastOf, KeyedSet} from './utils'
 import {ValueFormatter, RawValueFormatter} from './value-formatters'
 import {FileFormat} from './file-format-spec'
-const demangleCppModule = import('./demangle-cpp')
 
 export interface FrameInfo {
   key: string | number
@@ -404,16 +403,16 @@ export class Profile {
 
   // Demangle symbols for readability
   async demangle() {
-    let demangleCpp: ((name: string) => string) | null = null
+    let demangle: ((name: string) => string) | null = null
 
     for (let frame of this.frames) {
-      // This function converts a mangled C++ name such as "__ZNK7Support6ColorFeqERKS0_"
-      // into a human-readable symbol (in this case "Support::ColorF::==(Support::ColorF&)")
-      if (frame.name.startsWith('__Z')) {
-        if (!demangleCpp) {
-          demangleCpp = (await demangleCppModule).demangleCpp
+      // This function converts a mangled C++ and Rust name into a human-readable symbol.
+      if (frame.name.startsWith('__Z') || frame.name.startsWith('_R') || frame.name.startsWith('_Z')) {
+        if (!demangle) {
+          const demangleModule = await import('./demangle')
+          demangle = await demangleModule.loadDemangling()
         }
-        frame.name = demangleCpp(frame.name)
+        frame.name = demangle(frame.name)
       }
     }
   }

src/views/application.tsx

@@ -25,7 +25,7 @@ const importModule = import('../import')
 // We put them all in one place so we can directly control the relative priority
 // of these.
 importModule.then(() => {})
-import('../lib/demangle-cpp').then(() => {})
+import('../lib/demangle').then(() => {})
 import('source-map').then(() => {})
 
 async function importProfilesFromText(