author Simon Whitehead <>
Sat, 13 May 2017 15:12:15 -0500
changeset 358329 633151f5d481d49bd39900d43e6a75d77459a7bb
parent 354293 4d4a187ac1150f57bced2a8f73399d09ff01eefa
child 360393 3967231c7021738d27fd7097724ea1e02e72aecc
permissions -rw-r--r--
servo: Merge #16829 - Disallow negative duration for animation and transition (from hiikezoe:disallow-negative-duration); r=emilio <!-- Please describe your changes on the following line: --> --- <!-- Thank you for contributing to Servo! Please replace each `[ ]` by `[X]` when the step is complete, and replace `__` with appropriate data: --> - [X] `./mach build -d` does not report any errors - [X] `./mach test-tidy` does not report any errors - [X] These changes fix #15343 <!-- Either: --> - [X] There are tests for these changes written by @simon-whitehead . Thank you! <!-- Also, please make sure that "Allow edits from maintainers" checkbox is checked, so that we can help you if you get stuck somewhere along the way.--> <!-- Pull requests that do not address these steps are welcome, but they will require additional verification as part of the review process. --> Source-Repo: Source-Revision: 4613c0382ab76263fb8202ccf52f4c0520e44809

/* -*- 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 */

#ifndef nsJSUtils_h__
#define nsJSUtils_h__

 * This is not a generated file. It contains common utility functions 
 * invoked from the JavaScript code generated from IDL interfaces.
 * The goal of the utility functions is to cut down on the size of
 * the generated code itself.

#include "mozilla/Assertions.h"

#include "GeckoProfiler.h"
#include "jsapi.h"
#include "jsfriendapi.h"
#include "js/Conversions.h"
#include "nsString.h"

class nsIScriptContext;
class nsIScriptGlobalObject;

namespace mozilla {
namespace dom {
class AutoJSAPI;
class Element;
} // namespace dom
} // namespace mozilla

class nsJSUtils
  static bool GetCallingLocation(JSContext* aContext, nsACString& aFilename,
                                 uint32_t* aLineno = nullptr,
                                 uint32_t* aColumn = nullptr);
  static bool GetCallingLocation(JSContext* aContext, nsAString& aFilename,
                                 uint32_t* aLineno = nullptr,
                                 uint32_t* aColumn = nullptr);

  static nsIScriptGlobalObject *GetStaticScriptGlobal(JSObject* aObj);

  static nsIScriptContext *GetStaticScriptContext(JSObject* aObj);

   * Retrieve the inner window ID based on the given JSContext.
   * @param JSContext aContext
   *        The JSContext from which you want to find the inner window ID.
   * @returns uint64_t the inner window ID.
  static uint64_t GetCurrentlyRunningCodeInnerWindowID(JSContext *aContext);

  static nsresult CompileFunction(mozilla::dom::AutoJSAPI& jsapi,
                                  JS::AutoObjectVector& aScopeChain,
                                  JS::CompileOptions& aOptions,
                                  const nsACString& aName,
                                  uint32_t aArgCount,
                                  const char** aArgArray,
                                  const nsAString& aBody,
                                  JSObject** aFunctionObject);

  // ExecutionContext is used to switch compartment.
  class MOZ_STACK_CLASS ExecutionContext {
    // Register stack annotations for the Gecko profiler.
    mozilla::SamplerStackFrameRAII mSamplerRAII;

    JSContext* mCx;

    // Handles switching to our global's compartment.
    JSAutoCompartment mCompartment;

    // Set to a valid handle if a return value is expected.
    JS::Rooted<JS::Value> mRetValue;

    // Scope chain in which the execution takes place.
    JS::AutoObjectVector mScopeChain;

    // returned value forwarded when we have to interupt the execution eagerly
    // with mSkip.
    nsresult mRv;

    // Used to skip upcoming phases in case of a failure.  In such case the
    // result is carried by mRv.
    bool mSkip;

    // Should the result be serialized before being returned.
    bool mCoerceToString;

#ifdef DEBUG
    // Should we set the return value.
    bool mWantsReturnValue;

    bool mExpectScopeChain;


    // Enter compartment in which the code would be executed.  The JSContext
    // must come from an AutoEntryScript that has had
    // TakeOwnershipOfErrorReporting() called on it.
    ExecutionContext(JSContext* aCx, JS::Handle<JSObject*> aGlobal);

    ExecutionContext(const ExecutionContext&) = delete;
    ExecutionContext(ExecutionContext&&) = delete;

    ~ExecutionContext() {
      // This flag is resetted, when the returned value is extracted.

    // The returned value would be converted to a string if the
    // |aCoerceToString| is flag set.
    ExecutionContext& SetCoerceToString(bool aCoerceToString) {
      mCoerceToString = aCoerceToString;
      return *this;

    // Set the scope chain in which the code should be executed.
    void SetScopeChain(const JS::AutoObjectVector& aScopeChain);

    // Copy the returned value in the mutable handle argument, in case of a
    // evaluation failure either during the execution or the conversion of the
    // result to a string, the nsresult would be set to the corresponding result
    // code, and the mutable handle argument would remain unchanged.
    // The value returned in the mutable handle argument is part of the
    // compartment given as argument to the ExecutionContext constructor. If the
    // caller is in a different compartment, then the out-param value should be
    // wrapped by calling |JS_WrapValue|.
    MOZ_MUST_USE nsresult
    ExtractReturnValue(JS::MutableHandle<JS::Value> aRetValue);

    // After getting a notification that an off-thread compilation terminated,
    // this function will take the result of the parser by moving it to the main
    // thread before starting the execution of the script.
    // The compiled script would be returned in the |aScript| out-param.
    MOZ_MUST_USE nsresult JoinAndExec(void **aOffThreadToken,
                                      JS::MutableHandle<JSScript*> aScript);

    // Compile a script contained in a SourceBuffer, and execute it.
    nsresult CompileAndExec(JS::CompileOptions& aCompileOptions,
                            JS::SourceBufferHolder& aSrcBuf);

    // Compile a script contained in a string, and execute it.
    nsresult CompileAndExec(JS::CompileOptions& aCompileOptions,
                            const nsAString& aScript);

    // Decode a script contained in a buffer, and execute it.
    MOZ_MUST_USE nsresult DecodeAndExec(JS::CompileOptions& aCompileOptions,
                                        mozilla::Vector<uint8_t>& aBytecodeBuf,
                                        size_t aBytecodeIndex);

    // After getting a notification that an off-thread decoding terminated, this
    // function will get the result of the decoder by moving it to the main
    // thread before starting the execution of the script.
    MOZ_MUST_USE nsresult DecodeJoinAndExec(void **aOffThreadToken);

    // Similar to JoinAndExec, except that in addition to fecthing the source,
    // we register the fact that we plan to encode its bytecode later.
    MOZ_MUST_USE nsresult JoinEncodeAndExec(void **aOffThreadToken,
                                            mozilla::Vector<uint8_t>& aBytecodeBuf,
                                            JS::MutableHandle<JSScript*> aScript);

  static nsresult CompileModule(JSContext* aCx,
                                JS::SourceBufferHolder& aSrcBuf,
                                JS::Handle<JSObject*> aEvaluationGlobal,
                                JS::CompileOptions &aCompileOptions,
                                JS::MutableHandle<JSObject*> aModule);

  static nsresult ModuleDeclarationInstantiation(JSContext* aCx,
                                                 JS::Handle<JSObject*> aModule);

  static nsresult ModuleEvaluation(JSContext* aCx,
                                   JS::Handle<JSObject*> aModule);

  // Returns false if an exception got thrown on aCx.  Passing a null
  // aElement is allowed; that wil produce an empty aScopeChain.
  static bool GetScopeChainForElement(JSContext* aCx,
                                      mozilla::dom::Element* aElement,
                                      JS::AutoObjectVector& aScopeChain);

  static void ResetTimeZone();

template<typename T>
inline bool
AssignJSString(JSContext *cx, T &dest, JSString *s)
  size_t len = js::GetStringLength(s);
  static_assert(js::MaxStringLength < (1 << 28),
                "Shouldn't overflow here or in SetCapacity");
  if (MOZ_UNLIKELY(!dest.SetLength(len, mozilla::fallible))) {
    return false;
  return js::CopyStringChars(cx, dest.BeginWriting(), s, len);

inline void
AssignJSFlatString(nsAString &dest, JSFlatString *s)
  size_t len = js::GetFlatStringLength(s);
  static_assert(js::MaxStringLength < (1 << 28),
                "Shouldn't overflow here or in SetCapacity");
  js::CopyFlatStringChars(dest.BeginWriting(), s, len);

class nsAutoJSString : public nsAutoString

   * nsAutoJSString should be default constructed, which leaves it empty
   * (this->IsEmpty()), and initialized with one of the init() methods below.
  nsAutoJSString() {}

  bool init(JSContext* aContext, JSString* str)
    return AssignJSString(aContext, *this, str);

  bool init(JSContext* aContext, const JS::Value &v)
    if (v.isString()) {
      return init(aContext, v.toString());

    // Stringify, making sure not to run script.
    JS::Rooted<JSString*> str(aContext);
    if (v.isObject()) {
      str = JS_NewStringCopyZ(aContext, "[Object]");
    } else {
      JS::Rooted<JS::Value> rootedVal(aContext, v);
      str = JS::ToString(aContext, rootedVal);

    return str && init(aContext, str);

  bool init(JSContext* aContext, jsid id)
    JS::Rooted<JS::Value> v(aContext);
    return JS_IdToValue(aContext, id, &v) && init(aContext, v);

  bool init(const JS::Value &v);

  ~nsAutoJSString() {}

#endif /* nsJSUtils_h__ */