1 files changed, 130 insertions, 0 deletions
diff --git a/include/libcamera/base/log.h b/include/libcamera/base/log.h
new file mode 100644
index 00000000..b93c947a
--- /dev/null
+++ b/include/libcamera/base/log.h
@@ -0,0 +1,130 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2018, Google Inc.
+ *
+ * log.h - Logging infrastructure
+ */
+#ifndef __LIBCAMERA_BASE_LOG_H__
+#define __LIBCAMERA_BASE_LOG_H__
+
+#include <chrono>
+#include <sstream>
+
+#include <libcamera/base/class.h>
+#include <libcamera/base/utils.h>
+
+namespace libcamera {
+
+enum LogSeverity {
+	LogInvalid = -1,
+	LogDebug = 0,
+	LogInfo,
+	LogWarning,
+	LogError,
+	LogFatal,
+};
+
+class LogCategory
+{
+public:
+	explicit LogCategory(const char *name);
+
+	const char *name() const { return name_; }
+	LogSeverity severity() const { return severity_; }
+	void setSeverity(LogSeverity severity);
+
+	static const LogCategory &defaultCategory();
+
+private:
+	const char *name_;
+	LogSeverity severity_;
+};
+
+#define LOG_DECLARE_CATEGORY(name)					\
+extern const LogCategory &_LOG_CATEGORY(name)();
+
+#define LOG_DEFINE_CATEGORY(name)					\
+const LogCategory &_LOG_CATEGORY(name)()				\
+{									\
+	/* The instance will be deleted by the Logger destructor. */	\
+	static LogCategory *category = new LogCategory(#name);		\
+	return *category;						\
+}
+
+class LogMessage
+{
+public:
+	LogMessage(const char *fileName, unsigned int line,
+		   const LogCategory &category, LogSeverity severity);
+
+	LogMessage(LogMessage &&);
+	~LogMessage();
+
+	std::ostream &stream() { return msgStream_; }
+
+	const utils::time_point &timestamp() const { return timestamp_; }
+	LogSeverity severity() const { return severity_; }
+	const LogCategory &category() const { return category_; }
+	const std::string &fileInfo() const { return fileInfo_; }
+	const std::string msg() const { return msgStream_.str(); }
+
+private:
+	LIBCAMERA_DISABLE_COPY(LogMessage)
+
+	void init(const char *fileName, unsigned int line);
+
+	std::ostringstream msgStream_;
+	const LogCategory &category_;
+	LogSeverity severity_;
+	utils::time_point timestamp_;
+	std::string fileInfo_;
+};
+
+class Loggable
+{
+public:
+	virtual ~Loggable();
+
+protected:
+	virtual std::string logPrefix() const = 0;
+
+	LogMessage _log(const LogCategory *category, LogSeverity severity,
+			const char *fileName = __builtin_FILE(),
+			unsigned int line = __builtin_LINE()) const;
+};
+
+LogMessage _log(const LogCategory *category, LogSeverity severity,
+		const char *fileName = __builtin_FILE(),
+		unsigned int line = __builtin_LINE());
+
+#ifndef __DOXYGEN__
+#define _LOG_CATEGORY(name) logCategory##name
+
+#define _LOG1(severity) \
+	_log(nullptr, Log##severity).stream()
+#define _LOG2(category, severity) \
+	_log(&_LOG_CATEGORY(category)(), Log##severity).stream()
+
+/*
+ * Expand the LOG() macro to _LOG1() or _LOG2() based on the number of
+ * arguments.
+ */
+#define _LOG_MACRO(_1, _2, NAME, ...) NAME
+#define LOG(...) _LOG_MACRO(__VA_ARGS__, _LOG2, _LOG1)(__VA_ARGS__)
+#else /* __DOXYGEN___ */
+#define LOG(category, severity)
+#endif /* __DOXYGEN__ */
+
+#ifndef NDEBUG
+#define ASSERT(condition) static_cast<void>(({                          \
+	if (!(condition))                                               \
+		LOG(Fatal) << "assertion \"" #condition "\" failed in " \
+			   << __func__ << "()";                         \
+}))
+#else
+#define ASSERT(condition) static_cast<void>(false && (condition))
+#endif
+
+} /* namespace libcamera */
+
+#endif /* __LIBCAMERA_BASE_LOG_H__ */