testCompileScript.cpp

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/* 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 "mozilla/RefPtr.h"     // RefPtr

#include "mozilla/ScopeExit.h"  // MakeScopeExit

#include "mozilla/Utf8.h"       // mozilla::Utf8Unit

#include "frontend/CompilationStencil.h"  // JS::Stencil

#include "js/CompileOptions.h"  // JS::CompileOptions, JS::InstantiateOptions

#include "js/experimental/CompileScript.h"  // JS::NewFrontendContext

#include "js/SourceText.h"                  // JS::Source{Ownership,Text}

#include "jsapi-tests/tests.h"

#include "vm/ErrorReporting.h"

#include "vm/JSONPrinter.h"  // js::JSONPrinter

using namespace JS;

template <typename T>

static void dump(const T& data) {

  js::Fprinter printer(stderr);

  js::JSONPrinter json(printer, true);

  data->dump(json);

  printer.put("\n");

BEGIN_TEST(testCompileScript) {

  CHECK(testCompile());

  CHECK(testNonsyntacticCompile());

  CHECK(testCompileModule());

  CHECK(testPrepareForInstantiate());

  return true;

bool testCompile() {

  static constexpr std::string_view src = "42\n";

  static constexpr std::u16string_view src_16 = u"42\n";

  static_assert(src.length() == src_16.length(),

                "Source buffers must be same length");

  JS::CompileOptions options(cx);

  JS::FrontendContext* fc = JS::NewFrontendContext();

  CHECK(fc);

  auto destroyFc =

      mozilla::MakeScopeExit([fc] { JS::DestroyFrontendContext(fc); });

  {  // 16-bit characters

    JS::SourceText<char16_t> buf16;

    CHECK(buf16.init(cx, src_16.data(), src_16.length(),

                     JS::SourceOwnership::Borrowed));

    RefPtr<JS::Stencil> stencil =

        CompileGlobalScriptToStencil(fc, options, buf16);

    CHECK(stencil);

    CHECK(stencil->scriptExtra.size() == 1);

    CHECK(stencil->scriptExtra[0].extent.sourceStart == 0);

    CHECK(stencil->scriptExtra[0].extent.sourceEnd == 3);

    CHECK(stencil->scriptData.size() == 1);

    CHECK(stencil->scriptData[0].hasSharedData());  // has generated bytecode

    CHECK(stencil->scriptData[0].gcThingsLength == 1);

  {  // 8-bit characters

    JS::SourceText<mozilla::Utf8Unit> buf8;

    CHECK(

        buf8.init(cx, src.data(), src.length(), JS::SourceOwnership::Borrowed));

    RefPtr<JS::Stencil> stencil =

        CompileGlobalScriptToStencil(fc, options, buf8);

    CHECK(stencil);

    CHECK(stencil->scriptExtra.size() == 1);

    CHECK(stencil->scriptExtra[0].extent.sourceStart == 0);

    CHECK(stencil->scriptExtra[0].extent.sourceEnd == 3);

    CHECK(stencil->scriptData.size() == 1);

    CHECK(stencil->scriptData[0].hasSharedData());  // has generated bytecode

    CHECK(stencil->scriptData[0].gcThingsLength == 1);

  {  // propagates failures

    static constexpr std::string_view badSrc = "{ a: 1, b: 3\n";

    JS::SourceText<mozilla::Utf8Unit> srcBuf;

    CHECK(srcBuf.init(cx, badSrc.data(), badSrc.length(),

                      JS::SourceOwnership::Borrowed));

    RefPtr<JS::Stencil> stencil =

        CompileGlobalScriptToStencil(fc, options, srcBuf);

    CHECK(!stencil);

    CHECK(fc->maybeError().isSome());

    const js::CompileError& error = fc->maybeError().ref();

    CHECK(JSEXN_SYNTAXERR == error.exnType);

    CHECK(error.lineno == 1);

    CHECK(error.column.oneOriginValue() == 10);

  return true;

bool testNonsyntacticCompile() {

  const char* chars =

      "function f() { return x; }"

      "f();";

  JS::SourceText<mozilla::Utf8Unit> srcBuf;

  CHECK(srcBuf.init(cx, chars, strlen(chars), JS::SourceOwnership::Borrowed));

  JS::CompileOptions options(cx);

  options.setNonSyntacticScope(true);

  JS::FrontendContext* fc = JS::NewFrontendContext();

  CHECK(fc);

  auto destroyFc =

      mozilla::MakeScopeExit([fc] { JS::DestroyFrontendContext(fc); });

  RefPtr<JS::Stencil> stencil =

      CompileGlobalScriptToStencil(fc, options, srcBuf);

  CHECK(stencil);

  JS::InstantiateOptions instantiateOptions(options);

  JS::RootedScript script(

      cx, JS::InstantiateGlobalStencil(cx, instantiateOptions, stencil));

  CHECK(script);

  CHECK(script->hasNonSyntacticScope());

  return true;

bool testCompileModule() {

  static constexpr std::string_view src = "import 'a'; 42\n";

  static constexpr std::u16string_view src_16 = u"import 'a'; 42\n";

  static_assert(src.length() == src_16.length(),

                "Source buffers must be same length");

  JS::CompileOptions options(cx);

  JS::FrontendContext* fc = JS::NewFrontendContext();

  CHECK(fc);

  auto destroyFc =

      mozilla::MakeScopeExit([fc] { JS::DestroyFrontendContext(fc); });

  {  // 16-bit characters

    JS::SourceText<char16_t> buf16;

    CHECK(buf16.init(cx, src_16.data(), src_16.length(),

                     JS::SourceOwnership::Borrowed));

    RefPtr<JS::Stencil> stencil =

        CompileModuleScriptToStencil(fc, options, buf16);

    CHECK(stencil);

    CHECK(stencil->isModule());

    CHECK(stencil->scriptExtra.size() == 1);

    CHECK(stencil->scriptExtra[0].extent.sourceStart == 0);

    CHECK(stencil->scriptExtra[0].extent.sourceEnd == 15);

    CHECK(stencil->scriptData.size() == 1);

    CHECK(stencil->scriptData[0].hasSharedData());  // has generated bytecode

    CHECK(stencil->scriptData[0].gcThingsLength == 1);

  {  // 8-bit characters

    JS::SourceText<mozilla::Utf8Unit> buf8;

    CHECK(

        buf8.init(cx, src.data(), src.length(), JS::SourceOwnership::Borrowed));

    RefPtr<JS::Stencil> stencil =

        CompileModuleScriptToStencil(fc, options, buf8);

    CHECK(stencil);

    CHECK(stencil->scriptExtra.size() == 1);

    CHECK(stencil->scriptExtra[0].extent.sourceStart == 0);

    CHECK(stencil->scriptExtra[0].extent.sourceEnd == 15);

    CHECK(stencil->scriptData.size() == 1);

    CHECK(stencil->scriptData[0].hasSharedData());  // has generated bytecode

    CHECK(stencil->scriptData[0].gcThingsLength == 1);

  {  // propagates failures

    static constexpr std::string_view badSrc = "{ a: 1, b: 3\n";

    JS::SourceText<mozilla::Utf8Unit> srcBuf;

    CHECK(srcBuf.init(cx, badSrc.data(), badSrc.length(),

                      JS::SourceOwnership::Borrowed));

    RefPtr<JS::Stencil> stencil =

        CompileModuleScriptToStencil(fc, options, srcBuf);

    CHECK(!stencil);

    CHECK(fc->maybeError().isSome());

    const js::CompileError& error = fc->maybeError().ref();

    CHECK(JSEXN_SYNTAXERR == error.exnType);

    CHECK(error.lineno == 1);

    CHECK(error.column.oneOriginValue() == 10);

  return true;

bool testPrepareForInstantiate() {

  static constexpr std::u16string_view src_16 =

      u"function f() { return {'field': 42};}; f()['field']\n";

  JS::CompileOptions options(cx);

  JS::SourceText<char16_t> buf16;

  CHECK(buf16.init(cx, src_16.data(), src_16.length(),

                   JS::SourceOwnership::Borrowed));

  JS::FrontendContext* fc = JS::NewFrontendContext();

  CHECK(fc);

  auto destroyFc =

      mozilla::MakeScopeExit([fc] { JS::DestroyFrontendContext(fc); });

  RefPtr<JS::Stencil> stencil =

      CompileGlobalScriptToStencil(fc, options, buf16);

  CHECK(stencil);

  CHECK(stencil->scriptData.size() == 2);

  CHECK(stencil->scopeData.size() == 1);       // function f

  CHECK(stencil->parserAtomData.size() == 1);  // 'field'

  JS::InstantiationStorage storage;

  CHECK(JS::PrepareForInstantiate(fc, *stencil, storage));

  CHECK(storage.isValid());

  // TODO storage.gcOutput_ is private, so there isn't a good way to check the

  // scriptData and scopeData capacities

  return true;

END_TEST(testCompileScript);