Bug 1812540 - Part 1: Add JS::ToGetterId and JS::ToSetterId. r=sfink

Differential Revision: https://phabricator.services.mozilla.com/D168512

js/public/Id.h

@@ -255,6 +255,16 @@ MOZ_ALWAYS_INLINE void AssertIdIsNotGray(jsid id) {
 extern JS_PUBLIC_API PropertyKey GetWellKnownSymbolKey(JSContext* cx,
                                                        SymbolCode which);
 
+/**
+ * Generate getter/setter id for given id, by adding "get " or "set " prefix.
+ */
+extern JS_PUBLIC_API bool ToGetterId(
+    JSContext* cx, JS::Handle<JS::PropertyKey> id,
+    JS::MutableHandle<JS::PropertyKey> getterId);
+extern JS_PUBLIC_API bool ToSetterId(
+    JSContext* cx, JS::Handle<JS::PropertyKey> id,
+    JS::MutableHandle<JS::PropertyKey> setterId);
+
 }  // namespace JS
 
 namespace js {

js/src/jsapi-tests/moz.build

@@ -96,6 +96,7 @@ UNIFIED_SOURCES += [
     "testProfileStrings.cpp",
     "testPromise.cpp",
     "testPropCache.cpp",
+    "testPropertyKey.cpp",
     "testRecordTupleToSource.cpp",
     "testRegExp.cpp",
     "testResolveRecursion.cpp",

js/src/jsapi-tests/testPropertyKey.cpp

@@ -0,0 +1,69 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * vim: set ts=8 sts=2 et sw=2 tw=80:
+ */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "js/Id.h"  // JS::PropertyKey, JS::GetWellKnownSymbolKey, JS::ToGetterId, JS::ToSetterId
+#include "js/String.h"  // JSString, JS_AtomizeString, JS_StringEqualsAscii
+#include "js/Symbol.h"  // JS::Symbol, JS::SymbolCode
+#include "jsapi-tests/tests.h"
+
+BEGIN_TEST(testPropertyKeyGetterAndSetter) {
+  JS::Rooted<JSString*> str(cx, JS_AtomizeString(cx, "prop"));
+  CHECK(str);
+
+  JS::Rooted<JS::PropertyKey> strId(cx, JS::PropertyKey::NonIntAtom(str));
+  MOZ_ASSERT(strId.isString());
+
+  JS::Rooted<JS::PropertyKey> symId(
+      cx, JS::GetWellKnownSymbolKey(cx, JS::SymbolCode::iterator));
+  MOZ_ASSERT(symId.isSymbol());
+
+  JS::Rooted<JS::PropertyKey> numId(cx, JS::PropertyKey::Int(42));
+  MOZ_ASSERT(numId.isInt());
+
+  bool match;
+
+  JS::Rooted<JS::PropertyKey> strGetterId(cx);
+  CHECK(JS::ToGetterId(cx, strId, &strGetterId));
+  CHECK(strGetterId.isString());
+  CHECK(JS_StringEqualsAscii(cx, strGetterId.toString(), "get prop", &match));
+  CHECK(match);
+
+  JS::Rooted<JS::PropertyKey> strSetterId(cx);
+  CHECK(JS::ToSetterId(cx, strId, &strSetterId));
+  CHECK(strSetterId.isString());
+  CHECK(JS_StringEqualsAscii(cx, strSetterId.toString(), "set prop", &match));
+  CHECK(match);
+
+  JS::Rooted<JS::PropertyKey> symGetterId(cx);
+  CHECK(JS::ToGetterId(cx, symId, &symGetterId));
+  CHECK(symGetterId.isString());
+  CHECK(JS_StringEqualsAscii(cx, symGetterId.toString(),
+                             "get [Symbol.iterator]", &match));
+  CHECK(match);
+
+  JS::Rooted<JS::PropertyKey> symSetterId(cx);
+  CHECK(JS::ToSetterId(cx, symId, &symSetterId));
+  CHECK(symSetterId.isString());
+  CHECK(JS_StringEqualsAscii(cx, symSetterId.toString(),
+                             "set [Symbol.iterator]", &match));
+  CHECK(match);
+
+  JS::Rooted<JS::PropertyKey> numGetterId(cx);
+  CHECK(JS::ToGetterId(cx, numId, &numGetterId));
+  CHECK(numGetterId.isString());
+  CHECK(JS_StringEqualsAscii(cx, numGetterId.toString(), "get 42", &match));
+  CHECK(match);
+
+  JS::Rooted<JS::PropertyKey> numSetterId(cx);
+  CHECK(JS::ToSetterId(cx, numId, &numSetterId));
+  CHECK(numSetterId.isString());
+  CHECK(JS_StringEqualsAscii(cx, numSetterId.toString(), "set 42", &match));
+  CHECK(match);
+
+  return true;
+}
+END_TEST(testPropertyKeyGetterAndSetter)

js/src/jsapi.cpp

@@ -76,6 +76,7 @@
 #include "vm/EnvironmentObject.h"
 #include "vm/ErrorObject.h"
 #include "vm/ErrorReporting.h"
+#include "vm/FunctionPrefixKind.h"
 #include "vm/Interpreter.h"
 #include "vm/JSAtom.h"
 #include "vm/JSAtomState.h"
@@ -3389,6 +3390,28 @@ JS_PUBLIC_API JS::PropertyKey JS::GetWellKnownSymbolKey(JSContext* cx,
   return PropertyKey::Symbol(cx->wellKnownSymbols().get(which));
 }
 
+static bool AddPrefix(JSContext* cx, JS::Handle<JS::PropertyKey> id,
+                      FunctionPrefixKind prefixKind,
+                      JS::MutableHandle<JS::PropertyKey> out) {
+  JS::Rooted<JSAtom*> atom(cx, js::IdToFunctionName(cx, id, prefixKind));
+  if (!atom) {
+    return false;
+  }
+
+  out.set(JS::PropertyKey::NonIntAtom(atom));
+  return true;
+}
+
+JS_PUBLIC_API bool JS::ToGetterId(JSContext* cx, JS::Handle<JS::PropertyKey> id,
+                                  JS::MutableHandle<JS::PropertyKey> getterId) {
+  return AddPrefix(cx, id, FunctionPrefixKind::Get, getterId);
+}
+
+JS_PUBLIC_API bool JS::ToSetterId(JSContext* cx, JS::Handle<JS::PropertyKey> id,
+                                  JS::MutableHandle<JS::PropertyKey> setterId) {
+  return AddPrefix(cx, id, FunctionPrefixKind::Set, setterId);
+}
+
 #ifdef DEBUG
 static bool PropertySpecNameIsDigits(JSPropertySpec::Name name) {
   if (name.isSymbol()) {