8 files changed, 487 insertions, 0 deletions
diff --git a/js/public/shadow/Function.h b/js/public/shadow/Function.h
new file mode 100644
index 0000000000..0b9d4ac214
--- /dev/null
+++ b/js/public/shadow/Function.h
@@ -0,0 +1,48 @@
+/* -*- 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/. */
+
+/* Shadow definition of |JSFunction| innards.  Do not use this directly! */
+
+#ifndef js_shadow_Function_h
+#define js_shadow_Function_h
+
+#include <stdint.h>  // uint16_t
+
+#include "jstypes.h"  // JS_PUBLIC_API
+
+#include "js/CallArgs.h"       // JSNative
+#include "js/shadow/Object.h"  // JS::shadow::Object
+
+class JS_PUBLIC_API JSFunction;
+class JSJitInfo;
+
+namespace JS {
+
+namespace shadow {
+
+struct Function {
+  shadow::Object base;
+  uint16_t nargs;
+  uint16_t flags;
+  /* Used only for natives */
+  JSNative native;
+  const JSJitInfo* jitinfo;
+  void* _1;
+};
+
+inline Function* AsShadowFunction(JSFunction* fun) {
+  return reinterpret_cast<Function*>(fun);
+}
+
+inline const Function* AsShadowFunction(const JSFunction* fun) {
+  return reinterpret_cast<const Function*>(fun);
+}
+
+}  // namespace shadow
+
+}  // namespace JS
+
+#endif  // js_shadow_Function_h
diff --git a/js/public/shadow/Object.h b/js/public/shadow/Object.h
new file mode 100644
index 0000000000..68badf9b2b
--- /dev/null
+++ b/js/public/shadow/Object.h
@@ -0,0 +1,67 @@
+/* -*- 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/. */
+
+/*
+ * Shadow definition of |JSObject| innards.  (|js::NativeObject| is more
+ * accurate, but portions can sometimes be used in some non-native objects.)  Do
+ * not use this directly!
+ */
+
+#ifndef js_shadow_Object_h
+#define js_shadow_Object_h
+
+#include <stddef.h>  // size_t
+
+#include "js/shadow/Shape.h"  // JS::shadow::Shape
+#include "js/Value.h"         // JS::Value
+
+class JS_PUBLIC_API JSObject;
+
+namespace JS {
+
+class JS_PUBLIC_API Value;
+
+namespace shadow {
+
+struct ObjectGroup;
+
+/**
+ * This layout is shared by all native objects. For non-native objects, the
+ * group may always be accessed safely, and other members may be as well,
+ * depending on the object's specific layout.
+ */
+struct Object {
+  shadow::ObjectGroup* group;
+  shadow::Shape* shape;
+  Value* slots;
+  void* _1;
+
+  static constexpr size_t MAX_FIXED_SLOTS = 16;
+
+  size_t numFixedSlots() const {
+    return (shape->immutableFlags & shadow::Shape::FIXED_SLOTS_MASK) >>
+           shadow::Shape::FIXED_SLOTS_SHIFT;
+  }
+
+  Value* fixedSlots() const {
+    auto address = reinterpret_cast<uintptr_t>(this);
+    return reinterpret_cast<JS::Value*>(address + sizeof(shadow::Object));
+  }
+
+  Value& slotRef(size_t slot) const {
+    size_t nfixed = numFixedSlots();
+    if (slot < nfixed) {
+      return fixedSlots()[slot];
+    }
+    return slots[slot - nfixed];
+  }
+};
+
+}  // namespace shadow
+
+}  // namespace JS
+
+#endif  // js_shadow_Object_h
diff --git a/js/public/shadow/ObjectGroup.h b/js/public/shadow/ObjectGroup.h
new file mode 100644
index 0000000000..f95f60ced1
--- /dev/null
+++ b/js/public/shadow/ObjectGroup.h
@@ -0,0 +1,33 @@
+/* -*- 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/. */
+
+/* Shadow definition of |js::ObjectGroup| innards.  Do not use this directly! */
+
+#ifndef js_shadow_ObjectGroup_h
+#define js_shadow_ObjectGroup_h
+
+#include "jstypes.h"  // JS_PUBLIC_API
+
+struct JSClass;
+class JS_PUBLIC_API JSObject;
+
+namespace JS {
+
+class JS_PUBLIC_API Realm;
+
+namespace shadow {
+
+struct ObjectGroup {
+  const JSClass* clasp;
+  JSObject* proto;
+  JS::Realm* realm;
+};
+
+}  // namespace shadow
+
+}  // namespace JS
+
+#endif  // js_shadow_ObjectGroup_h
diff --git a/js/public/shadow/Realm.h b/js/public/shadow/Realm.h
new file mode 100644
index 0000000000..e3243d3483
--- /dev/null
+++ b/js/public/shadow/Realm.h
@@ -0,0 +1,38 @@
+/* -*- 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/. */
+
+/* Shadow definition of |JS::Realm| innards.  Do not use this directly! */
+
+#ifndef js_shadow_Realm_h
+#define js_shadow_Realm_h
+
+#include "jstypes.h"  // JS_PUBLIC_API
+
+namespace JS {
+
+class JS_PUBLIC_API Compartment;
+class JS_PUBLIC_API Realm;
+
+namespace shadow {
+
+class Realm {
+ protected:
+  JS::Compartment* compartment_;
+
+  explicit Realm(JS::Compartment* comp) : compartment_(comp) {}
+
+ public:
+  JS::Compartment* compartment() { return compartment_; }
+  static shadow::Realm* get(JS::Realm* realm) {
+    return reinterpret_cast<shadow::Realm*>(realm);
+  }
+};
+
+}  // namespace shadow
+
+}  // namespace JS
+
+#endif  // js_shadow_Realm_h
diff --git a/js/public/shadow/Shape.h b/js/public/shadow/Shape.h
new file mode 100644
index 0000000000..754f465162
--- /dev/null
+++ b/js/public/shadow/Shape.h
@@ -0,0 +1,46 @@
+/* -*- 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/. */
+
+/*
+ * Shadow definition of |js::BaseShape| and |js::Shape| innards.  Do not use
+ * this directly!
+ */
+
+#ifndef js_shadow_Shape_h
+#define js_shadow_Shape_h
+
+#include <stdint.h>  // uint32_t
+
+#include "jstypes.h"  // JS_PUBLIC_API
+
+#include "js/Id.h"  // JS::PropertyKey
+
+struct JSClass;
+class JS_PUBLIC_API JSObject;
+
+namespace JS {
+
+namespace shadow {
+
+struct BaseShape {
+  const JSClass* clasp_;
+};
+
+class Shape {
+ public:
+  shadow::BaseShape* base;
+  JS::PropertyKey _1;
+  uint32_t immutableFlags;
+
+  static constexpr uint32_t FIXED_SLOTS_SHIFT = 24;
+  static constexpr uint32_t FIXED_SLOTS_MASK = 0x1f << FIXED_SLOTS_SHIFT;
+};
+
+}  // namespace shadow
+
+}  // namespace JS
+
+#endif  // js_shadow_Shape_h
diff --git a/js/public/shadow/String.h b/js/public/shadow/String.h
new file mode 100644
index 0000000000..570c9f189b
--- /dev/null
+++ b/js/public/shadow/String.h
@@ -0,0 +1,120 @@
+/* -*- 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/. */
+
+/* Shadow definition of |JSString| innards.  Don't use this directly! */
+
+#ifndef js_shadow_String_h
+#define js_shadow_String_h
+
+#include <stdint.h>  // uint32_t, uintptr_t
+
+#include "jstypes.h"  // JS_PUBLIC_API, js::Bit, js::BitMask, JS_BITS_PER_WORD
+
+#include "js/TypeDecls.h"  // JS::Latin1Char
+
+class JS_PUBLIC_API JSAtom;
+struct JSExternalStringCallbacks;
+class JSLinearString;
+class JS_PUBLIC_API JSString;
+
+namespace js {
+namespace gc {
+struct Cell;
+}  // namespace gc
+}  // namespace js
+
+namespace JS {
+
+namespace shadow {
+
+struct String {
+  static constexpr uint32_t ATOM_BIT = js::Bit(3);
+  static constexpr uint32_t LINEAR_BIT = js::Bit(4);
+  static constexpr uint32_t INLINE_CHARS_BIT = js::Bit(6);
+  static constexpr uint32_t LATIN1_CHARS_BIT = js::Bit(9);
+  static constexpr uint32_t EXTERNAL_FLAGS = LINEAR_BIT | js::Bit(8);
+  static constexpr uint32_t TYPE_FLAGS_MASK = js::BitMask(9) - js::BitMask(3);
+  static constexpr uint32_t PERMANENT_ATOM_MASK = ATOM_BIT | js::Bit(8);
+
+  uintptr_t flags_;
+#if JS_BITS_PER_WORD == 32
+  uint32_t length_;
+#endif
+
+  union {
+    const JS::Latin1Char* nonInlineCharsLatin1;
+    const char16_t* nonInlineCharsTwoByte;
+    JS::Latin1Char inlineStorageLatin1[1];
+    char16_t inlineStorageTwoByte[1];
+  };
+  const JSExternalStringCallbacks* externalCallbacks;
+
+  uint32_t flags() const { return static_cast<uint32_t>(flags_); }
+  uint32_t length() const {
+#if JS_BITS_PER_WORD == 32
+    return length_;
+#else
+    return static_cast<uint32_t>(flags_ >> 32);
+#endif
+  }
+
+  static bool isPermanentAtom(const js::gc::Cell* cell) {
+    uint32_t flags = reinterpret_cast<const String*>(cell)->flags();
+    return (flags & PERMANENT_ATOM_MASK) == PERMANENT_ATOM_MASK;
+  }
+
+  bool isLinear() const { return flags() & LINEAR_BIT; }
+  bool hasLatin1Chars() const { return flags() & LATIN1_CHARS_BIT; }
+
+  // For hot code, prefer other type queries.
+  bool isExternal() const {
+    return (flags() & TYPE_FLAGS_MASK) == EXTERNAL_FLAGS;
+  }
+
+  const JS::Latin1Char* latin1LinearChars() const {
+    MOZ_ASSERT(isLinear());
+    MOZ_ASSERT(hasLatin1Chars());
+    return (flags() & String::INLINE_CHARS_BIT) ? inlineStorageLatin1
+                                                : nonInlineCharsLatin1;
+  }
+
+  const char16_t* twoByteLinearChars() const {
+    MOZ_ASSERT(isLinear());
+    MOZ_ASSERT(!hasLatin1Chars());
+    return (flags() & String::INLINE_CHARS_BIT) ? inlineStorageTwoByte
+                                                : nonInlineCharsTwoByte;
+  }
+};
+
+inline const String* AsShadowString(const JSString* str) {
+  return reinterpret_cast<const String*>(str);
+}
+
+inline String* AsShadowString(JSString* str) {
+  return reinterpret_cast<String*>(str);
+}
+
+inline const String* AsShadowString(const JSLinearString* str) {
+  return reinterpret_cast<const String*>(str);
+}
+
+inline String* AsShadowString(JSLinearString* str) {
+  return reinterpret_cast<String*>(str);
+}
+
+inline const String* AsShadowString(const JSAtom* str) {
+  return reinterpret_cast<const String*>(str);
+}
+
+inline String* AsShadowString(JSAtom* str) {
+  return reinterpret_cast<String*>(str);
+}
+
+}  // namespace shadow
+
+}  // namespace JS
+
+#endif  // js_shadow_String_h
diff --git a/js/public/shadow/Symbol.h b/js/public/shadow/Symbol.h
new file mode 100644
index 0000000000..a4b40139cc
--- /dev/null
+++ b/js/public/shadow/Symbol.h
@@ -0,0 +1,38 @@
+/* -*- 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/. */
+
+/* Shadow definition of |JS::Symbol| innards.  Do not use this directly! */
+
+#ifndef js_shadow_Symbol_h
+#define js_shadow_Symbol_h
+
+#include <stdint.h>  // uint32_t
+
+namespace js {
+namespace gc {
+struct Cell;
+}  // namespace gc
+}  // namespace js
+
+namespace JS {
+
+namespace shadow {
+
+struct Symbol {
+  void* _1;
+  uint32_t code_;
+  static constexpr uint32_t WellKnownAPILimit = 0x80000000;
+
+  static bool isWellKnownSymbol(const js::gc::Cell* cell) {
+    return reinterpret_cast<const Symbol*>(cell)->code_ < WellKnownAPILimit;
+  }
+};
+
+}  // namespace shadow
+
+}  // namespace JS
+
+#endif  // js_shadow_Symbol_h
diff --git a/js/public/shadow/Zone.h b/js/public/shadow/Zone.h
new file mode 100644
index 0000000000..a8d9c70dc4
--- /dev/null
+++ b/js/public/shadow/Zone.h
@@ -0,0 +1,97 @@
+/* -*- 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/. */
+
+/* Shadow definition of |JS::Zone| innards.  Do not use this directly! */
+
+#ifndef js_shadow_Zone_h
+#define js_shadow_Zone_h
+
+#include "mozilla/Assertions.h"  // MOZ_ASSERT
+
+#include <stdint.h>  // uint8_t, uint32_t
+
+#include "jspubtd.h"  // js::CurrentThreadCanAccessRuntime
+
+struct JS_PUBLIC_API JSRuntime;
+class JS_PUBLIC_API JSTracer;
+
+namespace JS {
+
+namespace shadow {
+
+struct Zone {
+  enum GCState : uint8_t {
+    NoGC,
+    Prepare,
+    MarkBlackOnly,
+    MarkBlackAndGray,
+    Sweep,
+    Finished,
+    Compact
+  };
+
+  enum Kind : uint8_t { NormalZone, AtomsZone, SelfHostingZone, SystemZone };
+
+ protected:
+  JSRuntime* const runtime_;
+  JSTracer* const barrierTracer_;  // A pointer to the JSRuntime's |gcMarker|.
+  uint32_t needsIncrementalBarrier_ = 0;
+  GCState gcState_ = NoGC;
+  const Kind kind_;
+
+  Zone(JSRuntime* runtime, JSTracer* barrierTracerArg, Kind kind)
+      : runtime_(runtime), barrierTracer_(barrierTracerArg), kind_(kind) {}
+
+ public:
+  bool needsIncrementalBarrier() const { return needsIncrementalBarrier_; }
+
+  JSTracer* barrierTracer() {
+    MOZ_ASSERT(needsIncrementalBarrier_);
+    MOZ_ASSERT(js::CurrentThreadCanAccessRuntime(runtime_));
+    return barrierTracer_;
+  }
+
+  JSRuntime* runtimeFromMainThread() const {
+    MOZ_ASSERT(js::CurrentThreadCanAccessRuntime(runtime_));
+    return runtime_;
+  }
+
+  // Note: Unrestricted access to the zone's runtime from an arbitrary
+  // thread can easily lead to races. Use this method very carefully.
+  JSRuntime* runtimeFromAnyThread() const { return runtime_; }
+
+  GCState gcState() const { return gcState_; }
+  bool wasGCStarted() const { return gcState_ != NoGC; }
+  bool isGCPreparing() const { return gcState_ == Prepare; }
+  bool isGCMarkingBlackOnly() const { return gcState_ == MarkBlackOnly; }
+  bool isGCMarkingBlackAndGray() const { return gcState_ == MarkBlackAndGray; }
+  bool isGCSweeping() const { return gcState_ == Sweep; }
+  bool isGCFinished() const { return gcState_ == Finished; }
+  bool isGCCompacting() const { return gcState_ == Compact; }
+  bool isGCMarking() const {
+    return isGCMarkingBlackOnly() || isGCMarkingBlackAndGray();
+  }
+  bool isGCMarkingOrSweeping() const {
+    return gcState_ >= MarkBlackOnly && gcState_ <= Sweep;
+  }
+  bool isGCSweepingOrCompacting() const {
+    return gcState_ == Sweep || gcState_ == Compact;
+  }
+
+  bool isAtomsZone() const { return kind_ == AtomsZone; }
+  bool isSelfHostingZone() const { return kind_ == SelfHostingZone; }
+  bool isSystemZone() const { return kind_ == SystemZone; }
+
+  static shadow::Zone* from(JS::Zone* zone) {
+    return reinterpret_cast<shadow::Zone*>(zone);
+  }
+};
+
+}  // namespace shadow
+
+}  // namespace JS
+
+#endif  // js_shadow_Zone_h