1 files changed, 76 insertions, 0 deletions
diff --git a/js/src/frontend/DoWhileEmitter.cpp b/js/src/frontend/DoWhileEmitter.cpp
new file mode 100644
index 0000000000..def0d1945c
--- /dev/null
+++ b/js/src/frontend/DoWhileEmitter.cpp
@@ -0,0 +1,76 @@
+/* -*- 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/. */
+
+#include "frontend/DoWhileEmitter.h"
+
+#include "frontend/BytecodeEmitter.h"
+#include "frontend/SourceNotes.h"
+#include "vm/Opcodes.h"
+#include "vm/StencilEnums.h"  // TryNoteKind
+
+using namespace js;
+using namespace js::frontend;
+
+using mozilla::Maybe;
+using mozilla::Nothing;
+
+DoWhileEmitter::DoWhileEmitter(BytecodeEmitter* bce) : bce_(bce) {}
+
+bool DoWhileEmitter::emitBody(const Maybe<uint32_t>& doPos,
+                              const Maybe<uint32_t>& bodyPos) {
+  MOZ_ASSERT(state_ == State::Start);
+
+  // Ensure that the column of the 'do' is set properly.
+  if (doPos) {
+    if (!bce_->updateSourceCoordNotes(*doPos)) {
+      return false;
+    }
+  }
+
+  // We need a nop here to make it possible to set a breakpoint on `do`.
+  if (!bce_->emit1(JSOp::Nop)) {
+    return false;
+  }
+
+  loopInfo_.emplace(bce_, StatementKind::DoLoop);
+
+  if (!loopInfo_->emitLoopHead(bce_, bodyPos)) {
+    return false;
+  }
+
+#ifdef DEBUG
+  state_ = State::Body;
+#endif
+  return true;
+}
+
+bool DoWhileEmitter::emitCond() {
+  MOZ_ASSERT(state_ == State::Body);
+
+  if (!loopInfo_->emitContinueTarget(bce_)) {
+    return false;
+  }
+
+#ifdef DEBUG
+  state_ = State::Cond;
+#endif
+  return true;
+}
+
+bool DoWhileEmitter::emitEnd() {
+  MOZ_ASSERT(state_ == State::Cond);
+
+  if (!loopInfo_->emitLoopEnd(bce_, JSOp::IfNe, TryNoteKind::Loop)) {
+    return false;
+  }
+
+  loopInfo_.reset();
+
+#ifdef DEBUG
+  state_ = State::End;
+#endif
+  return true;
+}