1 files changed, 152 insertions, 0 deletions
diff --git a/js/src/vm/Symbol.cpp b/js/src/vm/Symbol.cpp
new file mode 100644
index 000000000..59903c38a
--- /dev/null
+++ b/js/src/vm/Symbol.cpp
@@ -0,0 +1,152 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
+ * vim: set ts=8 sts=4 et sw=4 tw=99:
+ * 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 "vm/Symbol.h"
+
+#include "jscntxt.h"
+#include "jscompartment.h"
+
+#include "builtin/SymbolObject.h"
+#include "gc/Allocator.h"
+#include "gc/Rooting.h"
+#include "vm/StringBuffer.h"
+
+#include "jscompartmentinlines.h"
+
+using JS::Symbol;
+using namespace js;
+
+Symbol*
+Symbol::newInternal(ExclusiveContext* cx, JS::SymbolCode code, uint32_t hash, JSAtom* description,
+                    AutoLockForExclusiveAccess& lock)
+{
+    MOZ_ASSERT(cx->compartment() == cx->atomsCompartment(lock));
+
+    // Following js::AtomizeString, we grudgingly forgo last-ditch GC here.
+    Symbol* p = Allocate<JS::Symbol, NoGC>(cx);
+    if (!p) {
+        ReportOutOfMemory(cx);
+        return nullptr;
+    }
+    return new (p) Symbol(code, hash, description);
+}
+
+Symbol*
+Symbol::new_(ExclusiveContext* cx, JS::SymbolCode code, JSString* description)
+{
+    JSAtom* atom = nullptr;
+    if (description) {
+        atom = AtomizeString(cx, description);
+        if (!atom)
+            return nullptr;
+    }
+
+    // Lock to allocate. If symbol allocation becomes a bottleneck, this can
+    // probably be replaced with an assertion that we're on the main thread.
+    AutoLockForExclusiveAccess lock(cx);
+    AutoCompartment ac(cx, cx->atomsCompartment(lock), &lock);
+    return newInternal(cx, code, cx->compartment()->randomHashCode(), atom, lock);
+}
+
+Symbol*
+Symbol::for_(js::ExclusiveContext* cx, HandleString description)
+{
+    JSAtom* atom = AtomizeString(cx, description);
+    if (!atom)
+        return nullptr;
+
+    AutoLockForExclusiveAccess lock(cx);
+
+    SymbolRegistry& registry = cx->symbolRegistry(lock);
+    SymbolRegistry::AddPtr p = registry.lookupForAdd(atom);
+    if (p)
+        return *p;
+
+    AutoCompartment ac(cx, cx->atomsCompartment(lock), &lock);
+    Symbol* sym = newInternal(cx, SymbolCode::InSymbolRegistry, atom->hash(), atom, lock);
+    if (!sym)
+        return nullptr;
+
+    // p is still valid here because we have held the lock since the
+    // lookupForAdd call, and newInternal can't GC.
+    if (!registry.add(p, sym)) {
+        // SystemAllocPolicy does not report OOM.
+        ReportOutOfMemory(cx);
+        return nullptr;
+    }
+    return sym;
+}
+
+#ifdef DEBUG
+void
+Symbol::dump(FILE* fp)
+{
+    if (isWellKnownSymbol()) {
+        // All the well-known symbol names are ASCII.
+        description_->dumpCharsNoNewline(fp);
+    } else if (code_ == SymbolCode::InSymbolRegistry || code_ == SymbolCode::UniqueSymbol) {
+        fputs(code_ == SymbolCode::InSymbolRegistry ? "Symbol.for(" : "Symbol(", fp);
+
+        if (description_)
+            description_->dumpCharsNoNewline(fp);
+        else
+            fputs("undefined", fp);
+
+        fputc(')', fp);
+
+        if (code_ == SymbolCode::UniqueSymbol)
+            fprintf(fp, "@%p", (void*) this);
+    } else {
+        fprintf(fp, "<Invalid Symbol code=%u>", unsigned(code_));
+    }
+}
+#endif  // DEBUG
+
+bool
+js::SymbolDescriptiveString(JSContext* cx, Symbol* sym, MutableHandleValue result)
+{
+    // steps 2-5
+    StringBuffer sb(cx);
+    if (!sb.append("Symbol("))
+        return false;
+    RootedString str(cx, sym->description());
+    if (str) {
+        if (!sb.append(str))
+            return false;
+    }
+    if (!sb.append(')'))
+        return false;
+
+    // step 6
+    str = sb.finishString();
+    if (!str)
+        return false;
+    result.setString(str);
+    return true;
+}
+
+bool
+js::IsSymbolOrSymbolWrapper(const Value& v)
+{
+    return v.isSymbol() || (v.isObject() && v.toObject().is<SymbolObject>());
+}
+
+JS::Symbol*
+js::ToSymbolPrimitive(const Value& v)
+{
+    MOZ_ASSERT(IsSymbolOrSymbolWrapper(v));
+    return v.isSymbol() ? v.toSymbol() : v.toObject().as<SymbolObject>().unbox();
+}
+
+
+JS::ubi::Node::Size
+JS::ubi::Concrete<JS::Symbol>::size(mozilla::MallocSizeOf mallocSizeOf) const
+{
+    // If we start allocating symbols in the nursery, we will need to update
+    // this method.
+    MOZ_ASSERT(get().isTenured());
+    return js::gc::Arena::thingSize(get().asTenured().getAllocKind());
+}