libcamera: Move internal headers to include/libcamera/internal/

The libcamera internal headers are located in src/libcamera/include/.
The directory is added to the compiler headers search path with a meson
include_directories() directive, and internal headers are included with
(e.g. for the internal semaphore.h header)

  #include "semaphore.h"

All was well, until libcxx decided to implement the C++20
synchronization library. The __threading_support header gained a

  #include <semaphore.h>

to include the pthread's semaphore support. As include_directories()
adds src/libcamera/include/ to the compiler search path with -I, the
internal semaphore.h is included instead of the pthread version.
Needless to say, the compiler isn't happy.

Three options have been considered to fix this issue:

- Use -iquote instead of -I. The -iquote option instructs gcc to only
  consider the header search path for headers included with the ""
  version. Meson unfortunately doesn't support this option.

- Rename the internal semaphore.h header. This was deemed to be the
  beginning of a long whack-a-mole game, where namespace clashes with
  system libraries would appear over time (possibly dependent on
  particular system configurations) and would need to be constantly
  fixed.

- Move the internal headers to another directory to create a unique
  namespace through path components. This causes lots of churn in all
  the existing source files through the all project.

The first option would be best, but isn't available to us due to missing
support in meson. Even if -iquote support was added, we would need to
fix the problem before a new version of meson containing the required
support would be released.

The third option is thus the only practical solution available. Bite the
bullet, and do it, moving headers to include/libcamera/internal/.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Jacopo Mondi <jacopo@jmondi.org>

1 files changed, 130 insertions, 0 deletions

diff --git a/include/libcamera/internal/log.h b/include/libcamera/internal/log.h
new file mode 100644
index 00000000..cab2034a
--- /dev/null
+++ b/include/libcamera/internal/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_LOG_H__
+#define __LIBCAMERA_LOG_H__
+
+#include <chrono>
+#include <sstream>
+
+#include "libcamera/internal/utils.h"
+
+namespace libcamera {
+
+enum LogSeverity {
+	LogInvalid = -1,
+	LogDebug = 0,
+	LogInfo,
+	LogWarning,
+	LogError,
+	LogFatal,
+};
+
+class LogCategory
+{
+public:
+	explicit LogCategory(const char *name);
+	~LogCategory();
+
+	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)()				\
+{									\
+	static LogCategory category(#name);				\
+	return category;						\
+}
+
+class LogMessage
+{
+public:
+	LogMessage(const char *fileName, unsigned int line,
+		   LogSeverity severity);
+	LogMessage(const char *fileName, unsigned int line,
+		   const LogCategory &category, LogSeverity severity);
+	LogMessage(const LogMessage &) = delete;
+	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:
+	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 char *file, unsigned int line,
+			LogSeverity severity) const;
+	LogMessage _log(const char *file, unsigned int line,
+			const LogCategory &category,
+			LogSeverity severity) const;
+};
+
+LogMessage _log(const char *file, unsigned int line, LogSeverity severity);
+LogMessage _log(const char *file, unsigned int line,
+		const LogCategory &category, LogSeverity severity);
+
+#ifndef __DOXYGEN__
+#define _LOG_CATEGORY(name) logCategory##name
+
+#define _LOG1(severity) \
+	_log(__FILE__, __LINE__, Log##severity).stream()
+#define _LOG2(category, severity) \
+	_log(__FILE__, __LINE__, _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";	\
+}))
+#else
+#define ASSERT(condition) static_cast<void>(false && (condition))
+#endif
+
+} /* namespace libcamera */
+
+#endif /* __LIBCAMERA_LOG_H__ */