libcamera: log: Add an ASSERT macro

The ASSERT() macro is similar to the assert() macro defined by the C
standard, but uses the libcamera logging infrastructure.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>

src/libcamera/include/log.h

@@ -36,6 +36,15 @@ private:
 
 #define LOG(severity) LogMessage(__FILE__, __LINE__, Log##severity).stream()
 
+#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__ */

src/libcamera/log.cpp

@@ -48,6 +48,22 @@ namespace libcamera {
  * terminates immediately after printing the message.
  */
 
+/**
+ * \def ASSERT(condition)
+ * \brief Abort program execution if assertion fails
+ *
+ * If \a condition is false, ASSERT() logs an error message with the Fatal log
+ * level and aborts program execution.
+ *
+ * If the macro NDEBUG is defined before including log.h, ASSERT() generates no
+ * code.
+ *
+ * Using conditions that have side effects with ASSERT() is not recommended, as
+ * these effects would depend on whether NDEBUG is defined or not. Similarly,
+ * ASSERT() should not be used to check for errors that can occur under normal
+ * conditions as those checks would then be removed when compiling with NDEBUG.
+ */
+
 static const char *log_severity_name(LogSeverity severity)
 {
 	static const char * const names[] = {