Add LCF logger

CMakeLists.txt

@@ -41,7 +41,9 @@ set(LCF_SOURCES
 	src/lmt_treemap.cpp
 	src/lmu_movecommand.cpp
 	src/lmu_reader.cpp
+	src/log.h
 	src/lsd_reader.cpp
+	src/log_handler.cpp
 	src/reader_flags.cpp
 	src/reader_lcf.cpp
 	src/reader_struct.h
@@ -208,6 +210,7 @@ set(LCF_HEADERS
 	src/lcf/lmt/reader.h
 	src/lcf/lmu/reader.h
 	src/lcf/lsd/reader.h
+	src/lcf/log_handler.h
 	src/lcf/reader_lcf.h
 	src/lcf/reader_util.h
 	src/lcf/reader_xml.h

Makefile.am

@@ -57,7 +57,9 @@ liblcf_la_SOURCES = \
 	src/lmt_treemap.cpp \
 	src/lmu_movecommand.cpp \
 	src/lmu_reader.cpp \
+	src/log.h \
 	src/lsd_reader.cpp \
+	src/log_handler.cpp \
 	src/reader_flags.cpp \
 	src/reader_lcf.cpp \
 	src/reader_struct.h \
@@ -219,6 +221,7 @@ lcfinclude_HEADERS = \
 	src/lcf/flag_set.h \
 	src/lcf/ini.h \
 	src/lcf/inireader.h \
+	src/lcf/log_handler.h \
 	src/lcf/reader_lcf.h \
 	src/lcf/reader_util.h \
 	src/lcf/reader_xml.h \

src/lcf/log_handler.h

@@ -0,0 +1,47 @@
+/*
+ * This file is part of liblcf. Copyright (c) 2020 liblcf authors.
+ * https://github.com/EasyRPG/liblcf - https://easyrpg.org
+ *
+ * liblcf is Free/Libre Open Source Software, released under the MIT License.
+ * For the full copyright and license information, please view the COPYING
+ * file that was distributed with this source code.
+ */
+
+#ifndef LCF_OUTPUT_H
+#define LCF_OUTPUT_H
+
+#include "string_view.h"
+
+namespace lcf {
+namespace LogHandler {
+
+enum class Level {
+	Debug,
+	Warning,
+	Error,
+	Highest
+};
+
+using LogHandlerFn = void (*)(Level level, StringView message);
+
+/**
+ * Sets the output handler for all lcf logging.
+ * The default handler prints to standard error.
+ *
+ * @param fn New output handler. nullptr for default handler.
+ */
+void SetHandler(LogHandlerFn fn);
+
+/**
+ * Only report issues that have at least this log level.
+ * Use Highest to disable logging.
+ * Default: Debug
+ *
+ * @param new_level New log level
+ */
+void SetLevel(Level new_level);
+
+} // namespace LogHandler
+} // namespace lcf
+
+#endif

src/log.h

@@ -0,0 +1,24 @@
+/*
+ * This file is part of liblcf. Copyright (c) 2020 liblcf authors.
+ * https://github.com/EasyRPG/liblcf - https://easyrpg.org
+ *
+ * liblcf is Free/Libre Open Source Software, released under the MIT License.
+ * For the full copyright and license information, please view the COPYING
+ * file that was distributed with this source code.
+ */
+
+#ifndef LCF_LOG_H
+#define LCF_LOG_H
+
+#include "lcf/log_handler.h"
+
+namespace lcf {
+namespace Log {
+
+void Debug(const char* fmt, ...);
+void Warning(const char* fmt, ...);
+
+} // namespace Log
+} // namespace lcf
+
+#endif

src/log_handler.cpp

@@ -0,0 +1,88 @@
+/*
+ * This file is part of liblcf. Copyright (c) 2020 liblcf authors.
+ * https://github.com/EasyRPG/liblcf - https://easyrpg.org
+ *
+ * liblcf is Free/Libre Open Source Software, released under the MIT License.
+ * For the full copyright and license information, please view the COPYING
+ * file that was distributed with this source code.
+ */
+
+#include "lcf/log_handler.h"
+#include <cassert>
+#include <cstdarg>
+#include <cstdio>
+#include <iostream>
+
+namespace lcf {
+namespace LogHandler {
+namespace {
+	void DefaultHandler(lcf::LogHandler::Level level, StringView message) {
+		switch (level) {
+			case Level::Debug:
+				std::cerr << "Debug: ";
+				break;
+			case Level::Warning:
+				std::cerr << "Warning: ";
+				break;
+			case Level::Error:
+				std::cerr << "Error: ";
+				break;
+			default:
+				assert(false && "Invalid Log Level");
+		}
+		std::cerr << message << "\n";
+	}
+
+	Level level = Level::Debug;
+	LogHandlerFn output_fn = DefaultHandler;
+}
+
+void SetHandler(LogHandlerFn fn) {
+	if (!fn) {
+		output_fn = DefaultHandler;
+	} else {
+		output_fn = fn;
+	}
+}
+
+void SetLevel(Level new_level) {
+	level = new_level;
+}
+
+} // namespace Output
+
+namespace Log {
+namespace {
+	std::string format_string(char const* fmt, va_list args) {
+		char buf[4096];
+		int const result = vsnprintf(buf, sizeof(buf), fmt, args);
+		if (result < 0) {
+			return std::string();
+		}
+
+		return std::string(buf, static_cast<unsigned int>(result) < sizeof(buf) ? result : sizeof(buf));
+	}
+}
+
+void Debug(const char* fmt, ...) {
+	if (static_cast<int>(LogHandler::Level::Debug) >= static_cast<int>(LogHandler::level)) {
+		va_list args;
+		va_start(args, fmt);
+		auto msg = format_string(fmt, args);
+		LogHandler::output_fn(LogHandler::Level::Debug, msg);
+		va_end(args);
+	}
+}
+
+void Warning(const char* fmt, ...) {
+	if (static_cast<int>(LogHandler::Level::Warning) >= static_cast<int>(LogHandler::level)) {
+		va_list args;
+		va_start(args, fmt);
+		auto msg = format_string(fmt, args);
+		LogHandler::output_fn(LogHandler::Level::Warning, msg);
+		va_end(args);
+	}
+}
+
+} // namespace Log
+} // namespace lcf

src/lsd_reader.cpp

@@ -16,6 +16,7 @@
 #include "lcf/lsd/chunks.h"
 #include "lcf/rpg/save.h"
 #include "lcf/reader_util.h"
+#include "log.h"
 #include "reader_struct.h"
 
 namespace lcf {
@@ -43,7 +44,7 @@ void LSD_Reader::PrepareSave(rpg::Save& save, int32_t version, int32_t codepage)
 std::unique_ptr<rpg::Save> LSD_Reader::Load(StringView filename, StringView encoding) {
 	std::ifstream stream(ToString(filename), std::ios::binary);
 	if (!stream.is_open()) {
-		fprintf(stderr, "Failed to open LSD file `%s' for reading : %s\n", ToString(filename).c_str(), strerror(errno));
+		lcf::Log::Warning("Failed to open LSD file '%s' for reading : %s", ToString(filename).c_str(), strerror(errno));
 		return nullptr;
 	}
 	return LSD_Reader::Load(stream, encoding);

src/reader_lcf.cpp

@@ -13,6 +13,7 @@
 #include <limits>
 
 #include "lcf/reader_lcf.h"
+#include "log.h"
 
 namespace lcf {
 // Statics
@@ -276,7 +277,7 @@ int LcfReader::Peek() {
 }
 
 void LcfReader::Skip(const struct LcfReader::Chunk& chunk_info, const char* where) {
-	fprintf(stderr, "Skipped Chunk %02X (%" PRIu32 " byte) in lcf at %" PRIX32 " (%s)\n",
+	Log::Debug("Skipped Chunk %02X (%" PRIu32 " byte) in lcf at %" PRIX32 " (%s)\n",
 			chunk_info.ID, chunk_info.length, Tell(), where);
 
 	for (uint32_t i = 0; i < chunk_info.length; ++i) {