vm: add bindings for v8::CompileFunctionInContext

Adds a method compileFunction to the vm module, which serves as a
binding for v8::CompileFunctionInContext with appropriate args for
specifying the details, and provide params for the wrapper.

Eventually, we would be changing Module._compile to use this internally
over the standard Module.wrap

PR-URL: #21571
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Tiancheng "Timothy" Gu <timothygu99@gmail.com>
Reviewed-By: John-David Dalton <john.david.dalton@gmail.com>
Reviewed-By: Gus Caplan <me@gus.host>
Reviewed-By: James M Snell <jasnell@gmail.com>

doc/api/vm.md

@@ -637,6 +637,34 @@ console.log(globalVar);
 // 1000
 ```
 
+## vm.compileFunction(code[, params[, options]])
+<!-- YAML
+added: REPLACEME
+-->
+* `code` {string} The body of the function to compile.
+* `params` {string[]} An array of strings containing all parameters for the
+  function.
+* `options` {Object}
+  * `filename` {string} Specifies the filename used in stack traces produced
+    by this script. **Default:** `''`.
+  * `lineOffset` {number} Specifies the line number offset that is displayed
+    in stack traces produced by this script. **Default:** `0`.
+  * `columnOffset` {number} Specifies the column number offset that is displayed
+    in stack traces produced by this script. **Default:** `0`.
+  * `cachedData` {Buffer} Provides an optional `Buffer` with V8's code cache
+    data for the supplied source.
+  * `produceCachedData` {boolean} Specifies whether to produce new cache data.
+    **Default:** `false`.
+  * `parsingContext` {Object} The sandbox/context in which the said function
+    should be compiled in.
+  * `contextExtensions` {Object[]} An array containing a collection of context
+    extensions (objects wrapping the current scope) to be applied while
+    compiling. **Default:** `[]`.
+
+Compiles the given code into the provided context/sandbox (if no context is
+supplied, the current context is used), and returns it wrapped inside a
+function with the given `params`.
+
 ## vm.createContext([sandbox[, options]])
 <!-- YAML
 added: v0.3.1

lib/vm.js

@@ -25,14 +25,20 @@ const {
   ContextifyScript,
   makeContext,
   isContext: _isContext,
+  compileFunction: _compileFunction
 } = process.binding('contextify');
+
 const {
   ERR_INVALID_ARG_TYPE,
   ERR_OUT_OF_RANGE
 } = require('internal/errors').codes;
 const { isUint8Array } = require('internal/util/types');
+const { validateUint32 } = require('internal/validators');
 const kParsingContext = Symbol('script parsing context');
 
+const ArrayForEach = Function.call.bind(Array.prototype.forEach);
+const ArrayIsArray = Array.isArray;
+
 class Script extends ContextifyScript {
   constructor(code, options = {}) {
     code = `${code}`;
@@ -297,6 +303,94 @@ function runInThisContext(code, options) {
   return createScript(code, options).runInThisContext(options);
 }
 
+function compileFunction(code, params, options = {}) {
+  if (typeof code !== 'string') {
+    throw new ERR_INVALID_ARG_TYPE('code', 'string', code);
+  }
+  if (params !== undefined) {
+    if (!ArrayIsArray(params)) {
+      throw new ERR_INVALID_ARG_TYPE('params', 'Array', params);
+    }
+    ArrayForEach(params, (param, i) => {
+      if (typeof param !== 'string') {
+        throw new ERR_INVALID_ARG_TYPE(`params[${i}]`, 'string', param);
+      }
+    });
+  }
+
+  const {
+    filename = '',
+    columnOffset = 0,
+    lineOffset = 0,
+    cachedData = undefined,
+    produceCachedData = false,
+    parsingContext = undefined,
+    contextExtensions = [],
+  } = options;
+
+  if (typeof filename !== 'string') {
+    throw new ERR_INVALID_ARG_TYPE('options.filename', 'string', filename);
+  }
+  validateUint32(columnOffset, 'options.columnOffset');
+  validateUint32(lineOffset, 'options.lineOffset');
+  if (cachedData !== undefined && !isUint8Array(cachedData)) {
+    throw new ERR_INVALID_ARG_TYPE(
+      'options.cachedData',
+      'Uint8Array',
+      cachedData
+    );
+  }
+  if (typeof produceCachedData !== 'boolean') {
+    throw new ERR_INVALID_ARG_TYPE(
+      'options.produceCachedData',
+      'boolean',
+      produceCachedData
+    );
+  }
+  if (parsingContext !== undefined) {
+    if (
+      typeof parsingContext !== 'object' ||
+      parsingContext === null ||
+      !isContext(parsingContext)
+    ) {
+      throw new ERR_INVALID_ARG_TYPE(
+        'options.parsingContext',
+        'Context',
+        parsingContext
+      );
+    }
+  }
+  if (!ArrayIsArray(contextExtensions)) {
+    throw new ERR_INVALID_ARG_TYPE(
+      'options.contextExtensions',
+      'Array',
+      contextExtensions
+    );
+  }
+  ArrayForEach(contextExtensions, (extension, i) => {
+    if (typeof extension !== 'object') {
+      throw new ERR_INVALID_ARG_TYPE(
+        `options.contextExtensions[${i}]`,
+        'object',
+        extension
+      );
+    }
+  });
+
+  return _compileFunction(
+    code,
+    filename,
+    lineOffset,
+    columnOffset,
+    cachedData,
+    produceCachedData,
+    parsingContext,
+    contextExtensions,
+    params
+  );
+}
+
+
 module.exports = {
   Script,
   createContext,
@@ -305,6 +399,7 @@ module.exports = {
   runInNewContext,
   runInThisContext,
   isContext,
+  compileFunction,
 };
 
 if (process.binding('config').experimentalVMModules) {

src/node_contextify.cc

@@ -208,6 +208,7 @@ void ContextifyContext::Init(Environment* env, Local<Object> target) {
 
   env->SetMethod(target, "makeContext", MakeContext);
   env->SetMethod(target, "isContext", IsContext);
+  env->SetMethod(target, "compileFunction", CompileFunction);
 }
 
 
@@ -986,6 +987,144 @@ class ContextifyScript : public BaseObject {
 };
 
 
+void ContextifyContext::CompileFunction(
+    const FunctionCallbackInfo<Value>& args) {
+  Environment* env = Environment::GetCurrent(args);
+  Isolate* isolate = env->isolate();
+  Local<Context> context = env->context();
+
+  // Argument 1: source code
+  CHECK(args[0]->IsString());
+  Local<String> code = args[0].As<String>();
+
+  // Argument 2: filename
+  CHECK(args[1]->IsString());
+  Local<String> filename = args[1].As<String>();
+
+  // Argument 3: line offset
+  CHECK(args[2]->IsNumber());
+  Local<Integer> line_offset = args[2].As<Integer>();
+
+  // Argument 4: column offset
+  CHECK(args[3]->IsNumber());
+  Local<Integer> column_offset = args[3].As<Integer>();
+
+  // Argument 5: cached data (optional)
+  Local<Uint8Array> cached_data_buf;
+  if (!args[4]->IsUndefined()) {
+    CHECK(args[4]->IsUint8Array());
+    cached_data_buf = args[4].As<Uint8Array>();
+  }
+
+  // Argument 6: produce cache data
+  CHECK(args[5]->IsBoolean());
+  bool produce_cached_data = args[5]->IsTrue();
+
+  // Argument 7: parsing context (optional)
+  Local<Context> parsing_context;
+  if (!args[6]->IsUndefined()) {
+    CHECK(args[6]->IsObject());
+    ContextifyContext* sandbox =
+        ContextifyContext::ContextFromContextifiedSandbox(
+            env, args[6].As<Object>());
+    CHECK_NOT_NULL(sandbox);
+    parsing_context = sandbox->context();
+  } else {
+    parsing_context = context;
+  }
+
+  // Argument 8: context extensions (optional)
+  Local<Array> context_extensions_buf;
+  if (!args[7]->IsUndefined()) {
+    CHECK(args[7]->IsArray());
+    context_extensions_buf = args[7].As<Array>();
+  }
+
+  // Argument 9: params for the function (optional)
+  Local<Array> params_buf;
+  if (!args[8]->IsUndefined()) {
+    CHECK(args[8]->IsArray());
+    params_buf = args[8].As<Array>();
+  }
+
+  // Read cache from cached data buffer
+  ScriptCompiler::CachedData* cached_data = nullptr;
+  if (!cached_data_buf.IsEmpty()) {
+    ArrayBuffer::Contents contents = cached_data_buf->Buffer()->GetContents();
+    uint8_t* data = static_cast<uint8_t*>(contents.Data());
+    cached_data = new ScriptCompiler::CachedData(
+      data + cached_data_buf->ByteOffset(), cached_data_buf->ByteLength());
+  }
+
+  ScriptOrigin origin(filename, line_offset, column_offset);
+  ScriptCompiler::Source source(code, origin, cached_data);
+  ScriptCompiler::CompileOptions options;
+  if (source.GetCachedData() == nullptr) {
+    options = ScriptCompiler::kNoCompileOptions;
+  } else {
+    options = ScriptCompiler::kConsumeCodeCache;
+  }
+
+  TryCatch try_catch(isolate);
+  Context::Scope scope(parsing_context);
+
+  // Read context extensions from buffer
+  std::vector<Local<Object>> context_extensions;
+  if (!context_extensions_buf.IsEmpty()) {
+    for (uint32_t n = 0; n < context_extensions_buf->Length(); n++) {
+      Local<Value> val;
+      if (!context_extensions_buf->Get(context, n).ToLocal(&val)) return;
+      CHECK(val->IsObject());
+      context_extensions.push_back(val.As<Object>());
+    }
+  }
+
+  // Read params from params buffer
+  std::vector<Local<String>> params;
+  if (!params_buf.IsEmpty()) {
+    for (uint32_t n = 0; n < params_buf->Length(); n++) {
+      Local<Value> val;
+      if (!params_buf->Get(context, n).ToLocal(&val)) return;
+      CHECK(val->IsString());
+      params.push_back(val.As<String>());
+    }
+  }
+
+  MaybeLocal<Function> maybe_fun = ScriptCompiler::CompileFunctionInContext(
+      context, &source, params.size(), params.data(),
+      context_extensions.size(), context_extensions.data(), options);
+
+  Local<Function> fun;
+  if (maybe_fun.IsEmpty() || !maybe_fun.ToLocal(&fun)) {
+    ContextifyScript::DecorateErrorStack(env, try_catch);
+    try_catch.ReThrow();
+    return;
+  }
+
+  if (produce_cached_data) {
+    const std::unique_ptr<ScriptCompiler::CachedData>
+        cached_data(ScriptCompiler::CreateCodeCacheForFunction(fun, code));
+    bool cached_data_produced = cached_data != nullptr;
+    if (cached_data_produced) {
+      MaybeLocal<Object> buf = Buffer::Copy(
+          env,
+          reinterpret_cast<const char*>(cached_data->data),
+          cached_data->length);
+      if (fun->Set(
+          parsing_context,
+          env->cached_data_string(),
+          buf.ToLocalChecked()).IsNothing()) return;
+    }
+    if (fun->Set(
+        parsing_context,
+        env->cached_data_produced_string(),
+        Boolean::New(isolate, cached_data_produced)).IsNothing()) return;
+  }
+
+  args.GetReturnValue().Set(fun);
+}
+
+
 void Initialize(Local<Object> target,
                 Local<Value> unused,
                 Local<Context> context) {

src/node_contextify.h

@@ -58,6 +58,8 @@ class ContextifyContext {
  private:
   static void MakeContext(const v8::FunctionCallbackInfo<v8::Value>& args);
   static void IsContext(const v8::FunctionCallbackInfo<v8::Value>& args);
+  static void CompileFunction(
+      const v8::FunctionCallbackInfo<v8::Value>& args);
   static void WeakCallback(
       const v8::WeakCallbackInfo<ContextifyContext>& data);
   static void PropertyGetterCallback(