libcamera: log: Use compiler builtins to retrieve file and line number

Replace the __FILE__ and __LINE__ values passed to the _log() function
with default parameters, taking their values from the __builtin_FILE()
and __builtin_LINE() functions. This moves handling of the file and line
from the preprocessor to the compiler, which is generally preferred as
it increases type safety.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Tested-by: Sebastian Fricke <sebastian.fricke@posteo.net>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>

1 files changed, 8 insertions, 7 deletions

diff --git a/include/libcamera/internal/log.h b/include/libcamera/internal/log.h
index 0fdacc47..be0bab3c 100644
--- a/include/libcamera/internal/log.h
+++ b/include/libcamera/internal/log.h
@@ -89,21 +89,22 @@ public:
 protected:
 	virtual std::string logPrefix() const = 0;
 
-	LogMessage _log(const char *file, unsigned int line,
-			const LogCategory *category,
-			LogSeverity severity) const;
+	LogMessage _log(const LogCategory *category, LogSeverity severity,
+			const char *fileName = __builtin_FILE(),
+			unsigned int line = __builtin_LINE()) const;
 };
 
-LogMessage _log(const char *file, unsigned int line,
-		const LogCategory *category, LogSeverity severity);
+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(__FILE__, __LINE__, nullptr, Log##severity).stream()
+	_log(nullptr, Log##severity).stream()
 #define _LOG2(category, severity) \
-	_log(__FILE__, __LINE__, &_LOG_CATEGORY(category)(), Log##severity).stream()
+	_log(&_LOG_CATEGORY(category)(), Log##severity).stream()
 
 /*
  * Expand the LOG() macro to _LOG1() or _LOG2() based on the number of