1 files changed, 110 insertions, 0 deletions
diff --git a/js/public/Symbol.h b/js/public/Symbol.h
new file mode 100644
index 0000000000..1e16552b36
--- /dev/null
+++ b/js/public/Symbol.h
@@ -0,0 +1,110 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* 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/. */
+
+/* Symbols. */
+
+#ifndef js_Symbol_h
+#define js_Symbol_h
+
+#include "js/shadow/Symbol.h"  // JS::shadow::Symbol::WellKnownAPILimit
+
+#include <stddef.h>  // size_t
+#include <stdint.h>  // uintptr_t, uint32_t
+
+#include "jstypes.h"  // JS_PUBLIC_API
+
+#include "js/TypeDecls.h"
+
+namespace JS {
+
+class JS_PUBLIC_API Symbol;
+
+/**
+ * Create a new Symbol with the given description. This function never returns
+ * a Symbol that is in the Runtime-wide symbol registry.
+ *
+ * If description is null, the new Symbol's [[Description]] attribute is
+ * undefined.
+ */
+extern JS_PUBLIC_API Symbol* NewSymbol(JSContext* cx,
+                                       Handle<JSString*> description);
+
+/**
+ * Symbol.for as specified in ES6.
+ *
+ * Get a Symbol with the description 'key' from the Runtime-wide symbol
+ * registry. If there is not already a Symbol with that description in the
+ * registry, a new Symbol is created and registered. 'key' must not be null.
+ */
+extern JS_PUBLIC_API Symbol* GetSymbolFor(JSContext* cx, Handle<JSString*> key);
+
+/**
+ * Get the [[Description]] attribute of the given symbol.
+ *
+ * This function is infallible. If it returns null, that means the symbol's
+ * [[Description]] is undefined.
+ */
+extern JS_PUBLIC_API JSString* GetSymbolDescription(Handle<Symbol*> symbol);
+
+/* Well-known symbols. */
+#define JS_FOR_EACH_WELL_KNOWN_SYMBOL(MACRO) \
+  MACRO(isConcatSpreadable)                  \
+  MACRO(iterator)                            \
+  MACRO(match)                               \
+  MACRO(replace)                             \
+  MACRO(search)                              \
+  MACRO(species)                             \
+  MACRO(hasInstance)                         \
+  MACRO(split)                               \
+  MACRO(toPrimitive)                         \
+  MACRO(toStringTag)                         \
+  MACRO(unscopables)                         \
+  MACRO(asyncIterator)                       \
+  MACRO(matchAll)
+
+enum class SymbolCode : uint32_t {
+// There is one SymbolCode for each well-known symbol.
+#define JS_DEFINE_SYMBOL_ENUM(name) name,
+  JS_FOR_EACH_WELL_KNOWN_SYMBOL(
+      JS_DEFINE_SYMBOL_ENUM)  // SymbolCode::iterator, etc.
+#undef JS_DEFINE_SYMBOL_ENUM
+  Limit,
+  WellKnownAPILimit = JS::shadow::Symbol::WellKnownAPILimit,
+  PrivateNameSymbol = 0xfffffffd,  // created by the #PrivateName syntax.
+  InSymbolRegistry =
+      0xfffffffe,            // created by Symbol.for() or JS::GetSymbolFor()
+  UniqueSymbol = 0xffffffff  // created by Symbol() or JS::NewSymbol()
+};
+
+/* For use in loops that iterate over the well-known symbols. */
+const size_t WellKnownSymbolLimit = size_t(SymbolCode::Limit);
+
+/**
+ * Return the SymbolCode telling what sort of symbol `symbol` is.
+ *
+ * A symbol's SymbolCode never changes once it is created.
+ */
+extern JS_PUBLIC_API SymbolCode GetSymbolCode(Handle<Symbol*> symbol);
+
+/**
+ * Get one of the well-known symbols defined by ES6. A single set of well-known
+ * symbols is shared by all compartments in a JSRuntime.
+ *
+ * `which` must be in the range [0, WellKnownSymbolLimit).
+ */
+extern JS_PUBLIC_API Symbol* GetWellKnownSymbol(JSContext* cx,
+                                                SymbolCode which);
+
+/**
+ * Return true if the given JSPropertySpec::name or JSFunctionSpec::name value
+ * is actually a symbol code and not a string. See JS_SYM_FN.
+ */
+inline bool PropertySpecNameIsSymbol(uintptr_t name) {
+  return name != 0 && name - 1 < WellKnownSymbolLimit;
+}
+
+}  // namespace JS
+
+#endif /* js_Symbol_h */