Clean up of GLES2 Command Decoder by moving some of the error state into a separate class.

gpu/command_buffer/service/error_state.h

Index: gpu/command_buffer/service/error_state.h
diff --git a/gpu/command_buffer/service/error_state.h b/gpu/command_buffer/service/error_state.h
new file mode 100644
index 0000000000000000000000000000000000000000..c894248092786a736b2e1867f921806af4f22f1c
--- /dev/null
+++ b/gpu/command_buffer/service/error_state.h
@@ -0,0 +1,155 @@
+// Copyright (c) 2013 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// This file contains the ErrorState class.
+
+#ifndef GPU_COMMAND_BUFFER_SERVICE_ERROR_STATE_H_
+#define GPU_COMMAND_BUFFER_SERVICE_ERROR_STATE_H_
+
+#include "base/compiler_specific.h"
+#include "gpu/command_buffer/common/types.h"
+#include "gpu/gpu_export.h"
+
+namespace gpu {
+namespace gles2 {
+
+class Logger;
+
+// Use these macro to synthesize GL errors instead of calling the error_state
+// functions directly as they will propogate the __FILE__ and __LINE__.
+
+// Use to synthesize a GL error on the error_state.
+#define ERRORSTATE_SET_GL_ERROR(error_state, error, function_name, msg) \
+    error_state->SetGLError(__FILE__, __LINE__, error, function_name, msg)
+
+// Use to synthesize an INVALID_ENUM GL error on the error_state. Will attempt
+// to expand the enum to a string.
+#define ERRORSTATE_SET_GL_ERROR_INVALID_ENUM( \
+    error_state, function_name, value, label) \
+    error_state->SetGLErrorInvalidEnum( \
+        __FILE__, __LINE__, function_name, value, label)
+
+// Use to synthesize a GL error on the error_state for an invalid enum based
+// parameter. Will attempt to expand the parameter to a string.
+#define ERRORSTATE_SET_GL_ERROR_INVALID_PARAM( \
+    error_state, error, function_name, pname, param) \
+    error_state->SetGLErrorInvalidParam( \
+        __FILE__, __LINE__, error, function_name, pname, param)
+
+// Use to move all pending error to the wrapper so on your next GL call
+// you can see if that call generates an error.
+#define ERRORSTATE_COPY_REAL_GL_ERRORS_TO_WRAPPER(error_state, function_name) \
+    error_state->CopyRealGLErrorsToWrapper(__FILE__, __LINE__, function_name)
+// Use to look at the real GL error and still pass it on to the user.
+#define ERRORSTATE_PEEK_GL_ERROR(error_state, function_name) \
+    error_state->PeekGLError(__FILE__, __LINE__, function_name)
+// Use to clear all current GL errors. FAILS if there are any.
+#define ERRORSTATE_CLEAR_REAL_GL_ERRORS(error_state, function_name) \
+    error_state->ClearRealGLErrors(__FILE__, __LINE__, function_name)
+
+// TODO: Look into the current_decoder_error_ in gles2_cmd_decoder.cc.
+// Should it also be moved into here?
+
+class GPU_EXPORT ErrorState {
+ public:
+  virtual ~ErrorState();
+
+  // TODO - sanely separate setters from getters.
+  // TODO - make some things const.
+  virtual uint32 GetGLError() = 0;
+
+  virtual void SetGLError(
+      const char* filename,
+      int line,
+      unsigned int error,
+      const char* function_name,
+      const char* msg) = 0;
+  virtual void SetGLErrorInvalidEnum(
+      const char* filename,
+      int line,
+      const char* function_name,
+      unsigned int value,
+      const char* label) = 0;
+  virtual void SetGLErrorInvalidParam(
+      const char* filename,
+      int line,
+      unsigned int error,
+      const char* function_name,
+      unsigned int pname,
+      int param) = 0;
+
+  // Gets the GLError and stores it in our wrapper. Effectively
+  // this lets us peek at the error without losing it.
+  virtual unsigned int PeekGLError(
+      const char* filename, int line, const char* function_name) = 0;
+
+  // Copies the real GL errors to the wrapper. This is so we can
+  // make sure there are no native GL errors before calling some GL function
+  // so that on return we know any error generated was for that specific
+  // command.
+  virtual void CopyRealGLErrorsToWrapper(
+      const char* filename, int line, const char* function_name) = 0;
+
+  // Clear all real GL errors. This is to prevent the client from seeing any
+  // errors caused by GL calls that it was not responsible for issuing.
+  virtual void ClearRealGLErrors(
+      const char* filename, int line, const char* function_name) = 0;
+
+ protected:
+  ErrorState();
+
+  DISALLOW_COPY_AND_ASSIGN(ErrorState);
+};
+
+class ErrorStateImpl : public ErrorState {

[dsinclair, 2013/04/17 00:39:09]

Does this need to be in the public header or can it be moved to the .cc file? 
Everything should just be using the ErrorState api so Impl should be able to go
into an anonymous namespace in .cc.

You can then add a static Create() method to ErrorState above that returns an
ErrorStateImpl to handle the creation.

[kloveless, 2013/04/17 14:58:01]

Done.

+ public:
+  explicit ErrorStateImpl(Logger* logger);
+  virtual ~ErrorStateImpl();
+
+  virtual uint32 GetGLError() OVERRIDE;
+
+  virtual void SetGLError(
+      const char* filename,
+      int line,
+      unsigned int error,
+      const char* function_name,
+      const char* msg) OVERRIDE;
+  virtual void SetGLErrorInvalidEnum(
+      const char* filename,
+      int line,
+      const char* function_name,
+      unsigned int value,
+      const char* label) OVERRIDE;
+  virtual void SetGLErrorInvalidParam(
+      const char* filename,
+      int line,
+      unsigned int error,
+      const char* function_name,
+      unsigned int pname,
+      int param) OVERRIDE;
+
+  virtual unsigned int PeekGLError(
+      const char* filename, int line, const char* function_name) OVERRIDE;
+
+  virtual void CopyRealGLErrorsToWrapper(
+      const char* filename, int line, const char* function_name) OVERRIDE;
+
+  virtual void ClearRealGLErrors(
+      const char* filename, int line, const char* function_name) OVERRIDE;
+
+ private:
+  // The last error message set.
+  std::string last_error_;
+  // Current GL error bits.
+  uint32 error_bits_;
+
+  Logger* logger_;
+
+  DISALLOW_COPY_AND_ASSIGN(ErrorStateImpl);
+};
+
+}  // namespace gles2
+}  // namespace gpu
+
+#endif  // GPU_COMMAND_BUFFER_SERVICE_ERROR_STATE_H_