[interpreter, debugger] support debug breaks via bytecode array copy

src/interpreter/bytecodes.cc

Index: src/interpreter/bytecodes.cc
diff --git a/src/interpreter/bytecodes.cc b/src/interpreter/bytecodes.cc
index f58f37c770d6b4fd1165f4b2071b071a7e6b9e4c..fa780a404d8ecba885ae4b91c96a4c37ec86d2ad 100644
--- a/src/interpreter/bytecodes.cc
+++ b/src/interpreter/bytecodes.cc
@@ -71,6 +71,20 @@ Bytecode Bytecodes::FromByte(uint8_t value) {
 
 
 // static
+Bytecode Bytecodes::GetDebugBreak(Bytecode bytecode) {
+  switch (Size(bytecode)) {
+#define CASE(Name, ...)                                  \
+  case BytecodeTraits<__VA_ARGS__, OPERAND_TERM>::kSize: \
+    return Bytecode::k##Name;
+    DEBUG_BREAK_BYTECODE_LIST(CASE)
+#undef CASE
+    default:
+      break;
+  }
+  return Bytecode::kLdaUndefined;

[rmcilroy, 2016/02/16 10:46:38]

UNREACHABLE() and return static_cast<Bytecode>(-1);

[Yang, 2016/02/19 13:09:18]

Done.

+}
+
+// static
 int Bytecodes::Size(Bytecode bytecode) {
   DCHECK(bytecode <= Bytecode::kLast);
   switch (bytecode) {
@@ -267,6 +281,15 @@ bool Bytecodes::IsCallOrNew(Bytecode bytecode) {
 }
 
 // static
+bool Bytecodes::IsDebugBreak(Bytecode bytecode) {
+#define DEBUG_BREAK(Name, ...) \
+  if (bytecode == Bytecode::k##Name) return true;

[rmcilroy, 2016/02/16 10:46:38]

Could you do this as a switch statement instead please

[Yang, 2016/02/19 13:09:17]

Done.

+  DEBUG_BREAK_BYTECODE_LIST(DEBUG_BREAK);
+#undef DEBUG_BREAK
+  return false;
+}
+
+// static
 bool Bytecodes::IsJumpOrReturn(Bytecode bytecode) {
   return bytecode == Bytecode::kReturn || IsJump(bytecode);
 }
@@ -383,6 +406,9 @@ std::ostream& Bytecodes::Decode(std::ostream& os, const uint8_t* bytecode_start,
 
   os << bytecode << " ";
 
+  // Operands for the debug break are from the original instruction.
+  if (IsDebugBreak(bytecode)) return os;
+
   int number_of_operands = NumberOfOperands(bytecode);
   int range = 0;
   for (int i = 0; i < number_of_operands; i++) {