Extract logging logic

Previously logging logic was scattered over OS class implementations
with plenty of duplication. Major changes in this commit:

 - Extracted logging logic into a separate Logger hierarchy. It allows
   easy configuration of logging mechanism depending on compile-time or
   run-time configuration.

 - Implemented RotatedFileLogger which is usually used with StdLogger,
   providing persistency of logs. It is often important to be able to
   obtain logs of the game even in production to be able to understand
   what happened prior to some problem. On mobile there previously was
   no way to obtain the logs aside from having the device connected to
   your machine.

 - flush() is not performed in release mode for every logged line. It
   is only performed for errors.

5 files changed, 216 insertions, 136 deletions

diff --git a/platform/windows/SCsub b/platform/windows/SCsub
index fd041e096e..211a0e7406 100644
--- a/platform/windows/SCsub
+++ b/platform/windows/SCsub
@@ -19,6 +19,7 @@ common_win = [
     "stream_peer_winsock.cpp",
     "joypad.cpp",
     "power_windows.cpp",
+    "windows_terminal_logger.cpp"
 ]
 
 restarget = "godot_res" + env["OBJSUFFIX"]
diff --git a/platform/windows/os_windows.cpp b/platform/windows/os_windows.cpp
index db7cd0b938..cf53211f5a 100644
--- a/platform/windows/os_windows.cpp
+++ b/platform/windows/os_windows.cpp
@@ -48,6 +48,7 @@
 #include "servers/visual/visual_server_wrap_mt.h"
 #include "stream_peer_winsock.h"
 #include "tcp_server_winsock.h"
+#include "windows_terminal_logger.h"
 
 #include <process.h>
 #include <regstr.h>
@@ -205,6 +206,13 @@ void OS_Windows::initialize_core() {
 	cursor_shape = CURSOR_ARROW;
 }
 
+void OS_Windows::initialize_logger() {
+	Vector<Logger *> loggers;
+	loggers.push_back(memnew(WindowsTerminalLogger));
+	loggers.push_back(memnew(RotatedFileLogger("user://logs/log.txt")));
+	_set_logger(memnew(CompositeLogger(loggers)));
+}
+
 bool OS_Windows::can_draw() const {
 
 	return !minimized;
@@ -1231,38 +1239,6 @@ void OS_Windows::finalize_core() {
 	StreamPeerWinsock::cleanup();
 }
 
-void OS_Windows::vprint(const char *p_format, va_list p_list, bool p_stderr) {
-
-	const unsigned int BUFFER_SIZE = 16384;
-	char buf[BUFFER_SIZE + 1]; // +1 for the terminating character
-	int len = vsnprintf(buf, BUFFER_SIZE, p_format, p_list);
-	if (len <= 0)
-		return;
-	if (len >= BUFFER_SIZE)
-		len = BUFFER_SIZE; // Output is too big, will be truncated
-	buf[len] = 0;
-
-	int wlen = MultiByteToWideChar(CP_UTF8, 0, buf, len, NULL, 0);
-	if (wlen < 0)
-		return;
-
-	wchar_t *wbuf = (wchar_t *)malloc((len + 1) * sizeof(wchar_t));
-	MultiByteToWideChar(CP_UTF8, 0, buf, len, wbuf, wlen);
-	wbuf[wlen] = 0;
-
-	if (p_stderr)
-		fwprintf(stderr, L"%ls", wbuf);
-	else
-		wprintf(L"%ls", wbuf);
-
-#ifdef STDOUT_FILE
-//vwfprintf(stdo,p_format,p_list);
-#endif
-	free(wbuf);
-
-	fflush(stdout);
-};
-
 void OS_Windows::alert(const String &p_alert, const String &p_title) {
 
 	if (!is_no_window_mode_enabled())
@@ -1676,107 +1652,6 @@ void OS_Windows::request_attention() {
 	FlashWindowEx(&info);
 }
 
-void OS_Windows::print_error(const char *p_function, const char *p_file, int p_line, const char *p_code, const char *p_rationale, ErrorType p_type) {
-
-	HANDLE hCon = GetStdHandle(STD_OUTPUT_HANDLE);
-	if (!hCon || hCon == INVALID_HANDLE_VALUE) {
-
-		const char *err_details;
-		if (p_rationale && p_rationale[0])
-			err_details = p_rationale;
-		else
-			err_details = p_code;
-
-		switch (p_type) {
-			case ERR_ERROR:
-				print("ERROR: %s: %s\n", p_function, err_details);
-				print("   At: %s:%i\n", p_file, p_line);
-				break;
-			case ERR_WARNING:
-				print("WARNING: %s: %s\n", p_function, err_details);
-				print("     At: %s:%i\n", p_file, p_line);
-				break;
-			case ERR_SCRIPT:
-				print("SCRIPT ERROR: %s: %s\n", p_function, err_details);
-				print("          At: %s:%i\n", p_file, p_line);
-				break;
-			case ERR_SHADER:
-				print("SHADER ERROR: %s: %s\n", p_function, err_details);
-				print("          At: %s:%i\n", p_file, p_line);
-				break;
-		}
-
-	} else {
-
-		CONSOLE_SCREEN_BUFFER_INFO sbi; //original
-		GetConsoleScreenBufferInfo(hCon, &sbi);
-
-		WORD current_fg = sbi.wAttributes & (FOREGROUND_RED | FOREGROUND_GREEN | FOREGROUND_BLUE | FOREGROUND_INTENSITY);
-		WORD current_bg = sbi.wAttributes & (BACKGROUND_RED | BACKGROUND_GREEN | BACKGROUND_BLUE | BACKGROUND_INTENSITY);
-
-		uint32_t basecol = 0;
-		switch (p_type) {
-			case ERR_ERROR: basecol = FOREGROUND_RED; break;
-			case ERR_WARNING: basecol = FOREGROUND_RED | FOREGROUND_GREEN; break;
-			case ERR_SCRIPT: basecol = FOREGROUND_RED | FOREGROUND_BLUE; break;
-			case ERR_SHADER: basecol = FOREGROUND_GREEN | FOREGROUND_BLUE; break;
-		}
-
-		basecol |= current_bg;
-
-		if (p_rationale && p_rationale[0]) {
-
-			SetConsoleTextAttribute(hCon, basecol | FOREGROUND_INTENSITY);
-			switch (p_type) {
-				case ERR_ERROR: print("ERROR: "); break;
-				case ERR_WARNING: print("WARNING: "); break;
-				case ERR_SCRIPT: print("SCRIPT ERROR: "); break;
-				case ERR_SHADER: print("SHADER ERROR: "); break;
-			}
-
-			SetConsoleTextAttribute(hCon, current_fg | current_bg | FOREGROUND_INTENSITY);
-			print("%s\n", p_rationale);
-
-			SetConsoleTextAttribute(hCon, basecol);
-			switch (p_type) {
-				case ERR_ERROR: print("   At: "); break;
-				case ERR_WARNING: print("     At: "); break;
-				case ERR_SCRIPT: print("          At: "); break;
-				case ERR_SHADER: print("          At: "); break;
-			}
-
-			SetConsoleTextAttribute(hCon, current_fg | current_bg);
-			print("%s:%i\n", p_file, p_line);
-
-		} else {
-
-			SetConsoleTextAttribute(hCon, basecol | FOREGROUND_INTENSITY);
-			switch (p_type) {
-				case ERR_ERROR: print("ERROR: %s: ", p_function); break;
-				case ERR_WARNING: print("WARNING: %s: ", p_function); break;
-				case ERR_SCRIPT: print("SCRIPT ERROR: %s: ", p_function); break;
-				case ERR_SHADER: print("SCRIPT ERROR: %s: ", p_function); break;
-			}
-
-			SetConsoleTextAttribute(hCon, current_fg | current_bg | FOREGROUND_INTENSITY);
-			print("%s\n", p_code);
-
-			SetConsoleTextAttribute(hCon, basecol);
-			switch (p_type) {
-				case ERR_ERROR: print("   At: "); break;
-				case ERR_WARNING: print("     At: "); break;
-				case ERR_SCRIPT: print("          At: "); break;
-				case ERR_SHADER: print("          At: "); break;
-			}
-
-			SetConsoleTextAttribute(hCon, current_fg | current_bg);
-			print("%s:%i\n", p_file, p_line);
-		}
-
-		SetConsoleTextAttribute(hCon, sbi.wAttributes);
-	}
-}
-
 String OS_Windows::get_name() {
 
 	return "Windows";
@@ -2402,6 +2277,8 @@ OS_Windows::OS_Windows(HINSTANCE _hInstance) {
 #ifdef XAUDIO2_ENABLED
 	AudioDriverManager::add_driver(&driver_xaudio2);
 #endif
+
+	_set_logger(memnew(WindowsTerminalLogger));
 }
 
 OS_Windows::~OS_Windows() {
diff --git a/platform/windows/os_windows.h b/platform/windows/os_windows.h
index 8a955aa224..f80563d6fc 100644
--- a/platform/windows/os_windows.h
+++ b/platform/windows/os_windows.h
@@ -152,6 +152,7 @@ protected:
 	virtual int get_audio_driver_count() const;
 	virtual const char *get_audio_driver_name(int p_driver) const;
 
+	virtual void initialize_logger();
 	virtual void initialize_core();
 	virtual void initialize(const VideoMode &p_desired, int p_video_driver, int p_audio_driver);
 
@@ -180,9 +181,6 @@ protected:
 public:
 	LRESULT WndProc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam);
 
-	void print_error(const char *p_function, const char *p_file, int p_line, const char *p_code, const char *p_rationale, ErrorType p_type);
-
-	virtual void vprint(const char *p_format, va_list p_list, bool p_stderr = false);
 	virtual void alert(const String &p_alert, const String &p_title = "ALERT!");
 	String get_stdin_string(bool p_block);
 
diff --git a/platform/windows/windows_terminal_logger.cpp b/platform/windows/windows_terminal_logger.cpp
new file mode 100644
index 0000000000..ef8140ffa7
--- /dev/null
+++ b/platform/windows/windows_terminal_logger.cpp
@@ -0,0 +1,157 @@
+/*************************************************************************/
+/*  windows_terminal_logger.cpp                                          */
+/*************************************************************************/
+/*                       This file is part of:                           */
+/*                           GODOT ENGINE                                */
+/*                      https://godotengine.org                          */
+/*************************************************************************/
+/* Copyright (c) 2007-2017 Juan Linietsky, Ariel Manzur.                 */
+/* Copyright (c) 2014-2017 Godot Engine contributors (cf. AUTHORS.md)    */
+/*                                                                       */
+/* Permission is hereby granted, free of charge, to any person obtaining */
+/* a copy of this software and associated documentation files (the       */
+/* "Software"), to deal in the Software without restriction, including   */
+/* without limitation the rights to use, copy, modify, merge, publish,   */
+/* distribute, sublicense, and/or sell copies of the Software, and to    */
+/* permit persons to whom the Software is furnished to do so, subject to */
+/* the following conditions:                                             */
+/*                                                                       */
+/* The above copyright notice and this permission notice shall be        */
+/* included in all copies or substantial portions of the Software.       */
+/*                                                                       */
+/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,       */
+/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF    */
+/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
+/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY  */
+/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,  */
+/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE     */
+/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                */
+/*************************************************************************/
+
+#include "windows_terminal_logger.h"
+
+#ifdef WINDOWS_ENABLED
+
+#include <stdio.h>
+#include <windows.h>
+
+void WindowsTerminalLogger::logv(const char *p_format, va_list p_list, bool p_err) {
+	if (!should_log(p_err)) {
+		return;
+	}
+
+	const unsigned int BUFFER_SIZE = 16384;
+	char buf[BUFFER_SIZE + 1]; // +1 for the terminating character
+	int len = vsnprintf(buf, BUFFER_SIZE, p_format, p_list);
+	if (len <= 0)
+		return;
+	if (len >= BUFFER_SIZE)
+		len = BUFFER_SIZE; // Output is too big, will be truncated
+	buf[len] = 0;
+
+	int wlen = MultiByteToWideChar(CP_UTF8, 0, buf, len, NULL, 0);
+	if (wlen < 0)
+		return;
+
+	wchar_t *wbuf = (wchar_t *)malloc((len + 1) * sizeof(wchar_t));
+	MultiByteToWideChar(CP_UTF8, 0, buf, len, wbuf, wlen);
+	wbuf[wlen] = 0;
+
+	if (p_err)
+		fwprintf(stderr, L"%ls", wbuf);
+	else
+		wprintf(L"%ls", wbuf);
+
+	free(wbuf);
+
+#ifdef DEBUG_ENABLED
+	fflush(stdout);
+#endif
+}
+
+void WindowsTerminalLogger::log_error(const char *p_function, const char *p_file, int p_line, const char *p_code, const char *p_rationale, ErrorType p_type) {
+	if (!should_log(true)) {
+		return;
+	}
+
+#ifndef UWP_ENABLED
+	HANDLE hCon = GetStdHandle(STD_OUTPUT_HANDLE);
+	if (!hCon || hCon == INVALID_HANDLE_VALUE) {
+#endif
+		StdLogger::log_error(p_function, p_file, p_line, p_code, p_rationale, p_type);
+#ifndef UWP_ENABLED
+	} else {
+
+		CONSOLE_SCREEN_BUFFER_INFO sbi; //original
+		GetConsoleScreenBufferInfo(hCon, &sbi);
+
+		WORD current_fg = sbi.wAttributes & (FOREGROUND_RED | FOREGROUND_GREEN | FOREGROUND_BLUE | FOREGROUND_INTENSITY);
+		WORD current_bg = sbi.wAttributes & (BACKGROUND_RED | BACKGROUND_GREEN | BACKGROUND_BLUE | BACKGROUND_INTENSITY);
+
+		uint32_t basecol = 0;
+		switch (p_type) {
+			case ERR_ERROR: basecol = FOREGROUND_RED; break;
+			case ERR_WARNING: basecol = FOREGROUND_RED | FOREGROUND_GREEN; break;
+			case ERR_SCRIPT: basecol = FOREGROUND_RED | FOREGROUND_BLUE; break;
+			case ERR_SHADER: basecol = FOREGROUND_GREEN | FOREGROUND_BLUE; break;
+		}
+
+		basecol |= current_bg;
+
+		if (p_rationale && p_rationale[0]) {
+
+			SetConsoleTextAttribute(hCon, basecol | FOREGROUND_INTENSITY);
+			switch (p_type) {
+				case ERR_ERROR: logf("ERROR: "); break;
+				case ERR_WARNING: logf("WARNING: "); break;
+				case ERR_SCRIPT: logf("SCRIPT ERROR: "); break;
+				case ERR_SHADER: logf("SHADER ERROR: "); break;
+			}
+
+			SetConsoleTextAttribute(hCon, current_fg | current_bg | FOREGROUND_INTENSITY);
+			logf("%s\n", p_rationale);
+
+			SetConsoleTextAttribute(hCon, basecol);
+			switch (p_type) {
+				case ERR_ERROR: logf("   At: "); break;
+				case ERR_WARNING: logf("     At: "); break;
+				case ERR_SCRIPT: logf("          At: "); break;
+				case ERR_SHADER: logf("          At: "); break;
+			}
+
+			SetConsoleTextAttribute(hCon, current_fg | current_bg);
+			logf("%s:%i\n", p_file, p_line);
+
+		} else {
+
+			SetConsoleTextAttribute(hCon, basecol | FOREGROUND_INTENSITY);
+			switch (p_type) {
+				case ERR_ERROR: logf("ERROR: %s: ", p_function); break;
+				case ERR_WARNING: logf("WARNING: %s: ", p_function); break;
+				case ERR_SCRIPT: logf("SCRIPT ERROR: %s: ", p_function); break;
+				case ERR_SHADER: logf("SCRIPT ERROR: %s: ", p_function); break;
+			}
+
+			SetConsoleTextAttribute(hCon, current_fg | current_bg | FOREGROUND_INTENSITY);
+			logf("%s\n", p_code);
+
+			SetConsoleTextAttribute(hCon, basecol);
+			switch (p_type) {
+				case ERR_ERROR: logf("   At: "); break;
+				case ERR_WARNING: logf("     At: "); break;
+				case ERR_SCRIPT: logf("          At: "); break;
+				case ERR_SHADER: logf("          At: "); break;
+			}
+
+			SetConsoleTextAttribute(hCon, current_fg | current_bg);
+			logf("%s:%i\n", p_file, p_line);
+		}
+
+		SetConsoleTextAttribute(hCon, sbi.wAttributes);
+	}
+#endif
+}
+
+WindowsTerminalLogger::~WindowsTerminalLogger() {}
+
+#endif
\ No newline at end of file
diff --git a/platform/windows/windows_terminal_logger.h b/platform/windows/windows_terminal_logger.h
new file mode 100644
index 0000000000..f6b1a68d18
--- /dev/null
+++ b/platform/windows/windows_terminal_logger.h
@@ -0,0 +1,47 @@
+/*************************************************************************/
+/*  windows_terminal_logger.h                                            */
+/*************************************************************************/
+/*                       This file is part of:                           */
+/*                           GODOT ENGINE                                */
+/*                      https://godotengine.org                          */
+/*************************************************************************/
+/* Copyright (c) 2007-2017 Juan Linietsky, Ariel Manzur.                 */
+/* Copyright (c) 2014-2017 Godot Engine contributors (cf. AUTHORS.md)    */
+/*                                                                       */
+/* Permission is hereby granted, free of charge, to any person obtaining */
+/* a copy of this software and associated documentation files (the       */
+/* "Software"), to deal in the Software without restriction, including   */
+/* without limitation the rights to use, copy, modify, merge, publish,   */
+/* distribute, sublicense, and/or sell copies of the Software, and to    */
+/* permit persons to whom the Software is furnished to do so, subject to */
+/* the following conditions:                                             */
+/*                                                                       */
+/* The above copyright notice and this permission notice shall be        */
+/* included in all copies or substantial portions of the Software.       */
+/*                                                                       */
+/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,       */
+/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF    */
+/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
+/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY  */
+/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,  */
+/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE     */
+/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                */
+/*************************************************************************/
+
+#ifndef WINDOWS_TERMINAL_LOGGER_H
+#define WINDOWS_TERMINAL_LOGGER_H
+
+#ifdef WINDOWS_ENABLED
+
+#include "io/logger.h"
+
+class WindowsTerminalLogger : public StdLogger {
+public:
+	virtual void logv(const char *p_format, va_list p_list, bool p_err);
+	virtual void log_error(const char *p_function, const char *p_file, int p_line, const char *p_code, const char *p_rationale, ErrorType p_type = ERR_ERROR);
+	virtual ~WindowsTerminalLogger();
+};
+
+#endif
+
+#endif
\ No newline at end of file