[Interpreter] Add option to trace bytecode execution.

src/interpreter/interpreter.cc

 // Copyright 2015 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/interpreter/interpreter.h"
 
+#include "src/ast/prettyprinter.h"
 #include "src/code-factory.h"
 #include "src/compiler.h"
 #include "src/compiler/interpreter-assembler.h"
 #include "src/factory.h"
 #include "src/interpreter/bytecode-generator.h"
 #include "src/interpreter/bytecodes.h"
 #include "src/zone.h"
 
 namespace v8 {
 namespace internal {
@@ skipping 36 matching lines @@
       Handle<Code> code = assembler.GenerateCode();                   \
       handler_table->set(static_cast<int>(Bytecode::k##Name), *code); \
     }
     BYTECODE_LIST(GENERATE_CODE)
 #undef GENERATE_CODE
   }
 }
 
 
 bool Interpreter::MakeBytecode(CompilationInfo* info) {
+  if (FLAG_print_bytecode || FLAG_print_source || FLAG_print_ast) {
+    OFStream os(stdout);
+    base::SmartArrayPointer<char> name = info->GetDebugName();
+    os << "[generating bytecode for function: " << info->GetDebugName().get()
+       << "]" << std::endl
+       << std::flush;
+  }
+
+#ifdef DEBUG
+  if (info->parse_info() && FLAG_print_source) {
+    OFStream os(stdout);
+    os << "--- Source from AST ---" << std::endl
+       << PrettyPrinter(info->isolate()).PrintProgram(info->literal())
+       << std::endl
+       << std::flush;
+  }
+
+  if (info->parse_info() && FLAG_print_ast) {
+    OFStream os(stdout);
+    os << "--- AST ---" << std::endl
+       << AstPrinter(info->isolate()).PrintProgram(info->literal()) << std::endl
+       << std::flush;
+  }
+#endif  // DEBUG
+
   BytecodeGenerator generator(info->isolate(), info->zone());
   info->EnsureFeedbackVector();
   Handle<BytecodeArray> bytecodes = generator.MakeBytecode(info);
   if (FLAG_print_bytecode) {
     OFStream os(stdout);
     os << "Function: " << info->GetDebugName().get() << std::endl;
     bytecodes->Print(os);
     os << std::flush;
   }
 
   info->SetBytecodeArray(bytecodes);
   info->SetCode(info->isolate()->builtins()->InterpreterEntryTrampoline());
   return true;
 }
 
 
 bool Interpreter::IsInterpreterTableInitialized(
     Handle<FixedArray> handler_table) {
+  if (FLAG_trace_ignition) {
+    // Regenerate table to add bytecode tracing operations.

[Michael Starzinger, 2016/01/28 12:07:06]

Well played, well played, I like it! :)

[rmcilroy, 2016/01/28 16:39:51]

Acknowledged.

+    return false;
+  }
   DCHECK(handler_table->length() == static_cast<int>(Bytecode::kLast) + 1);
   return handler_table->get(0) != isolate_->heap()->undefined_value();
 }
 
-
 // LdaZero
 //
 // Load literal '0' into the accumulator.
 void Interpreter::DoLdaZero(compiler::InterpreterAssembler* assembler) {
   Node* zero_value = __ NumberConstant(0.0);
   __ SetAccumulator(zero_value);
   __ Dispatch();
 }
 
 
@@ skipping 1761 matching lines @@
   Node* index_reg = __ BytecodeOperandReg(0);
   Node* index = __ LoadRegister(index_reg);
   Node* result = __ CallRuntime(Runtime::kForInStep, index);
   __ SetAccumulator(result);
   __ Dispatch();
 }
 
 }  // namespace interpreter
 }  // namespace internal
 }  // namespace v8