1 files changed, 85 insertions, 0 deletions
diff --git a/js/src/builtin/Generator.js b/js/src/builtin/Generator.js
new file mode 100644
index 0000000000..de53f2c7f1
--- /dev/null
+++ b/js/src/builtin/Generator.js
@@ -0,0 +1,85 @@
+/* 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/. */
+
+function GeneratorNext(val) {
+    // The IsSuspendedGenerator call below is not necessary for correctness.
+    // It's a performance optimization to check for the common case with a
+    // single call. It's also inlined in Baseline.
+
+    if (!IsSuspendedGenerator(this)) {
+        if (!IsObject(this) || !IsGeneratorObject(this))
+            return callFunction(CallGeneratorMethodIfWrapped, this, val, "GeneratorNext");
+
+        if (GeneratorObjectIsClosed(this))
+            return { value: undefined, done: true };
+
+        if (GeneratorIsRunning(this))
+            ThrowTypeError(JSMSG_NESTING_GENERATOR);
+    }
+
+    try {
+        return resumeGenerator(this, val, "next");
+    } catch (e) {
+        if (!GeneratorObjectIsClosed(this))
+            GeneratorSetClosed(this);
+        throw e;
+    }
+}
+
+function GeneratorThrow(val) {
+    if (!IsSuspendedGenerator(this)) {
+        if (!IsObject(this) || !IsGeneratorObject(this))
+            return callFunction(CallGeneratorMethodIfWrapped, this, val, "GeneratorThrow");
+
+        if (GeneratorObjectIsClosed(this))
+            throw val;
+
+        if (GeneratorIsRunning(this))
+            ThrowTypeError(JSMSG_NESTING_GENERATOR);
+    }
+
+    try {
+        return resumeGenerator(this, val, "throw");
+    } catch (e) {
+        if (!GeneratorObjectIsClosed(this))
+            GeneratorSetClosed(this);
+        throw e;
+    }
+}
+
+function GeneratorReturn(val) {
+    if (!IsSuspendedGenerator(this)) {
+        if (!IsObject(this) || !IsGeneratorObject(this))
+            return callFunction(CallGeneratorMethodIfWrapped, this, val, "GeneratorReturn");
+
+        if (GeneratorObjectIsClosed(this))
+            return { value: val, done: true };
+
+        if (GeneratorIsRunning(this))
+            ThrowTypeError(JSMSG_NESTING_GENERATOR);
+    }
+
+    try {
+        var rval = { value: val, done: true };
+        return resumeGenerator(this, rval, "return");
+    } catch (e) {
+        if (!GeneratorObjectIsClosed(this))
+            GeneratorSetClosed(this);
+        throw e;
+    }
+}
+
+function InterpretGeneratorResume(gen, val, kind) {
+    // If we want to resume a generator in the interpreter, the script containing
+    // the resumeGenerator/JSOp::Resume also has to run in the interpreter. The
+    // forceInterpreter() call below compiles to a bytecode op that prevents us
+    // from JITing this script.
+    forceInterpreter();
+    if (kind === "next")
+       return resumeGenerator(gen, val, "next");
+    if (kind === "throw")
+       return resumeGenerator(gen, val, "throw");
+    assert(kind === "return", "Invalid resume kind");
+    return resumeGenerator(gen, val, "return");
+}