vm: support parsing a script in a specific context

PR-URL: https://github.com/nodejs/node/pull/14888
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: Eugene Ostroukhov <eostroukhov@google.com>

lib/vm.js

@@ -21,8 +21,14 @@
 
 'use strict';
 
-const binding = process.binding('contextify');
-const Script = binding.ContextifyScript;
+const {
+  ContextifyScript: Script,
+  kParsingContext,
+
+  makeContext,
+  isContext,
+  runInDebugContext
+} = process.binding('contextify');
 
 // The binding provides a few useful primitives:
 // - Script(code, { filename = "evalmachine.anonymous",
@@ -62,11 +68,11 @@ Script.prototype.runInNewContext = function(sandbox, options) {
 function createContext(sandbox) {
   if (sandbox === undefined) {
     sandbox = {};
-  } else if (binding.isContext(sandbox)) {
+  } else if (isContext(sandbox)) {
     return sandbox;
   }
 
-  binding.makeContext(sandbox);
+  makeContext(sandbox);
   return sandbox;
 }
 
@@ -99,16 +105,33 @@ function sigintHandlersWrap(fn, thisArg, argsArray) {
   }
 }
 
-function runInDebugContext(code) {
-  return binding.runInDebugContext(code);
-}
-
 function runInContext(code, contextifiedSandbox, options) {
+  if (typeof options === 'string') {
+    options = {
+      filename: options,
+      [kParsingContext]: contextifiedSandbox
+    };
+  } else {
+    options = Object.assign({}, options, {
+      [kParsingContext]: contextifiedSandbox
+    });
+  }
   return createScript(code, options)
     .runInContext(contextifiedSandbox, options);
 }
 
 function runInNewContext(code, sandbox, options) {
+  sandbox = createContext(sandbox);
+  if (typeof options === 'string') {
+    options = {
+      filename: options,
+      [kParsingContext]: sandbox
+    };
+  } else {
+    options = Object.assign({}, options, {
+      [kParsingContext]: sandbox
+    });
+  }
   return createScript(code, options).runInNewContext(sandbox, options);
 }
 
@@ -124,5 +147,5 @@ module.exports = {
   runInContext,
   runInNewContext,
   runInThisContext,
-  isContext: binding.isContext
+  isContext
 };

src/env.h

@@ -318,6 +318,7 @@ struct http2_state;
   V(tls_wrap_constructor_function, v8::Function)                              \
   V(tty_constructor_template, v8::FunctionTemplate)                           \
   V(udp_constructor_function, v8::Function)                                   \
+  V(vm_parsing_context_symbol, v8::Symbol)                                    \
   V(url_constructor_function, v8::Function)                                   \
   V(write_wrap_constructor_function, v8::Function)                            \
 

src/node_contextify.cc

@@ -61,6 +61,7 @@ using v8::Script;
 using v8::ScriptCompiler;
 using v8::ScriptOrigin;
 using v8::String;
+using v8::Symbol;
 using v8::TryCatch;
 using v8::Uint8Array;
 using v8::UnboundScript;
@@ -531,6 +532,16 @@ class ContextifyScript : public BaseObject {
 
     target->Set(class_name, script_tmpl->GetFunction());
     env->set_script_context_constructor_template(script_tmpl);
+
+    Local<Symbol> parsing_context_symbol =
+        Symbol::New(env->isolate(),
+                    FIXED_ONE_BYTE_STRING(env->isolate(),
+                                          "script parsing context"));
+    env->set_vm_parsing_context_symbol(parsing_context_symbol);
+    target->Set(env->context(),
+                FIXED_ONE_BYTE_STRING(env->isolate(), "kParsingContext"),
+                parsing_context_symbol)
+        .FromJust();
   }
 
 
@@ -555,6 +566,7 @@ class ContextifyScript : public BaseObject {
     Maybe<bool> maybe_display_errors = GetDisplayErrorsArg(env, options);
     MaybeLocal<Uint8Array> cached_data_buf = GetCachedData(env, options);
     Maybe<bool> maybe_produce_cached_data = GetProduceCachedData(env, options);
+    MaybeLocal<Context> maybe_context = GetContext(env, options);
     if (try_catch.HasCaught()) {
       try_catch.ReThrow();
       return;
@@ -583,6 +595,8 @@ class ContextifyScript : public BaseObject {
     else if (produce_cached_data)
       compile_options = ScriptCompiler::kProduceCodeCache;
 
+    Context::Scope scope(maybe_context.FromMaybe(env->context()));
+
     MaybeLocal<UnboundScript> v8_script = ScriptCompiler::CompileUnboundScript(
         env->isolate(),
         &source,
@@ -935,6 +949,41 @@ class ContextifyScript : public BaseObject {
     return value->ToInteger(env->context());
   }
 
+  static MaybeLocal<Context> GetContext(Environment* env,
+                                        Local<Value> options) {
+    if (!options->IsObject())
+      return MaybeLocal<Context>();
+
+    MaybeLocal<Value> maybe_value =
+        options.As<Object>()->Get(env->context(),
+                                  env->vm_parsing_context_symbol());
+    Local<Value> value;
+    if (!maybe_value.ToLocal(&value))
+      return MaybeLocal<Context>();
+
+    if (!value->IsObject()) {
+      if (!value->IsNullOrUndefined()) {
+        env->ThrowTypeError(
+            "contextifiedSandbox argument must be an object.");
+      }
+      return MaybeLocal<Context>();
+    }
+
+    ContextifyContext* sandbox =
+        ContextifyContext::ContextFromContextifiedSandbox(
+            env, value.As<Object>());
+    if (!sandbox) {
+      env->ThrowTypeError(
+          "sandbox argument must have been converted to a context.");
+      return MaybeLocal<Context>();
+    }
+
+    Local<Context> context = sandbox->context();
+    if (context.IsEmpty())
+      return MaybeLocal<Context>();
+    return context;
+  }
+
 
   static bool EvalMachine(Environment* env,
                           const int64_t timeout,

test/inspector/test-scriptparsed-context.js

@@ -0,0 +1,101 @@
+'use strict';
+const common = require('../common');
+common.skipIfInspectorDisabled();
+common.crashOnUnhandledRejection();
+const { NodeInstance } = require('./inspector-helper.js');
+const assert = require('assert');
+
+const script = `
+  'use strict';
+  const assert = require('assert');
+  const vm = require('vm');
+  const { kParsingContext } = process.binding('contextify');
+  debugger;
+
+  global.outer = true;
+  global.inner = false;
+  const context = vm.createContext({
+    outer: false,
+    inner: true
+  });
+  debugger;
+
+  const scriptMain = new vm.Script("outer");
+  debugger;
+
+  const scriptContext = new vm.Script("inner", {
+    [kParsingContext]: context
+  });
+  debugger;
+
+  assert.strictEqual(scriptMain.runInThisContext(), true);
+  assert.strictEqual(scriptMain.runInContext(context), false);
+  assert.strictEqual(scriptContext.runInThisContext(), false);
+  assert.strictEqual(scriptContext.runInContext(context), true);
+  debugger;
+
+  vm.runInContext('inner', context);
+  debugger;
+
+  vm.runInNewContext('Array', {});
+  debugger;
+`;
+
+async function getContext(session) {
+  const created =
+      await session.waitForNotification('Runtime.executionContextCreated');
+  return created.params.context;
+}
+
+async function checkScriptContext(session, context) {
+  const scriptParsed =
+      await session.waitForNotification('Debugger.scriptParsed');
+  assert.strictEqual(scriptParsed.params.executionContextId, context.id);
+}
+
+async function runTests() {
+  const instance = new NodeInstance(['--inspect-brk=0', '--expose-internals'],
+                                    script);
+  const session = await instance.connectInspectorSession();
+  await session.send([
+    { 'method': 'Debugger.enable' },
+    { 'method': 'Runtime.runIfWaitingForDebugger' }
+  ]);
+  await session.waitForBreakOnLine(5, '[eval]');
+
+  await session.send({ 'method': 'Runtime.enable' });
+  const topContext = await getContext(session);
+  await session.send({ 'method': 'Debugger.resume' });
+  const childContext = await getContext(session);
+  await session.waitForBreakOnLine(13, '[eval]');
+
+  console.error('[test]', 'Script associated with current context by default');
+  await session.send({ 'method': 'Debugger.resume' });
+  await checkScriptContext(session, topContext);
+  await session.waitForBreakOnLine(16, '[eval]');
+
+  console.error('[test]', 'Script associated with selected context');
+  await session.send({ 'method': 'Debugger.resume' });
+  await checkScriptContext(session, childContext);
+  await session.waitForBreakOnLine(21, '[eval]');
+
+  console.error('[test]', 'Script is unbound');
+  await session.send({ 'method': 'Debugger.resume' });
+  await session.waitForBreakOnLine(27, '[eval]');
+
+  console.error('[test]', 'vm.runInContext associates script with context');
+  await session.send({ 'method': 'Debugger.resume' });
+  await checkScriptContext(session, childContext);
+  await session.waitForBreakOnLine(30, '[eval]');
+
+  console.error('[test]', 'vm.runInNewContext associates script with context');
+  await session.send({ 'method': 'Debugger.resume' });
+  const thirdContext = await getContext(session);
+  await checkScriptContext(session, thirdContext);
+  await session.waitForBreakOnLine(33, '[eval]');
+
+  await session.runToCompletion();
+  assert.strictEqual(0, (await instance.expectShutdown()).exitCode);
+}
+
+runTests();