From 4a6f2834843dc562b5c87a2dc89987f2790b8637 Mon Sep 17 00:00:00 2001
From: Connor McLaughlin <mclaughc@outlook.com>
Date: Mon, 4 Nov 2019 00:55:07 +1000
Subject: [PATCH] CPU: Add trace log to file support

---
 src/core/bus.cpp      |  6 ++++++
 src/core/cpu_core.cpp | 38 ++++++++++++++++++++++++++++++++++++++
 src/core/cpu_core.h   |  5 +++++
 3 files changed, 49 insertions(+)

diff --git a/src/core/bus.cpp b/src/core/bus.cpp
index 9d9da929c..5b5b95c6e 100644
--- a/src/core/bus.cpp
+++ b/src/core/bus.cpp
@@ -376,7 +376,13 @@ void Bus::DoWriteEXP2(MemoryAccessSize size, u32 offset, u32 value)
     if (value == '\n')
     {
       if (!m_tty_line_buffer.IsEmpty())
+      {
         Log_InfoPrintf("TTY: %s", m_tty_line_buffer.GetCharArray());
+#ifdef _DEBUG
+        if (CPU::LOG_EXECUTION)
+          CPU::WriteToExecutionLog("TTY: %s\n", m_tty_line_buffer.GetCharArray());
+#endif
+      }
       m_tty_line_buffer.Clear();
     }
     else
diff --git a/src/core/cpu_core.cpp b/src/core/cpu_core.cpp
index d54674cc2..20ed2e900 100644
--- a/src/core/cpu_core.cpp
+++ b/src/core/cpu_core.cpp
@@ -6,7 +6,33 @@
 Log_SetChannel(CPU::Core);
 
 namespace CPU {
+
 bool TRACE_EXECUTION = false;
+bool LOG_EXECUTION = false;
+
+void WriteToExecutionLog(const char* format, ...)
+{
+  static std::FILE* log_file = nullptr;
+  static bool log_file_opened = false;
+
+  std::va_list ap;
+  va_start(ap, format);
+
+  if (!log_file_opened)
+  {
+    log_file = std::fopen("cpu_log.txt", "wb");
+    log_file_opened = true;
+  }
+
+  if (log_file)
+  {
+    std::vfprintf(log_file, format, ap);
+    std::fflush(log_file);
+  }
+
+  va_end(ap);
+}
+
 
 Core::Core() = default;
 
@@ -495,6 +521,14 @@ static void PrintInstruction(u32 bits, u32 pc, Core* state)
   std::printf("%08x: %08x %s\n", pc, bits, instr.GetCharArray());
 }
 
+static void LogInstruction(u32 bits, u32 pc, Core* state)
+{
+  TinyString instr;
+  DisassembleInstruction(&instr, pc, bits, state);
+
+  WriteToExecutionLog("%08x: %08x %s\n", pc, bits, instr.GetCharArray());
+}
+
 static constexpr bool AddOverflow(u32 old_value, u32 add_value, u32 new_value)
 {
   return (((new_value ^ old_value) & (new_value ^ add_value)) & UINT32_C(0x80000000)) != 0;
@@ -596,8 +630,12 @@ void Core::ExecuteInstruction()
   }
 #endif
 
+#ifdef _DEBUG
   if (TRACE_EXECUTION)
     PrintInstruction(inst.bits, m_current_instruction_pc, this);
+  if (LOG_EXECUTION)
+    LogInstruction(inst.bits, m_current_instruction_pc, this);
+#endif
 
   switch (inst.op)
   {
diff --git a/src/core/cpu_core.h b/src/core/cpu_core.h
index 2a0abf653..924d46bf3 100644
--- a/src/core/cpu_core.h
+++ b/src/core/cpu_core.h
@@ -88,6 +88,7 @@ private:
   }
 
   void DisassembleAndPrint(u32 addr);
+  void DisassembleAndLog(u32 addr);
   void DisassembleAndPrint(u32 addr, u32 instructions_before, u32 instructions_after);
 
   // Fetches the instruction at m_regs.npc
@@ -156,6 +157,10 @@ private:
 };
 
 extern bool TRACE_EXECUTION;
+extern bool LOG_EXECUTION;
+
+// Write to CPU execution log file.
+void WriteToExecutionLog(const char* format, ...);
 
 } // namespace CPU