QtDebug: Include file, line, function information

Record the file, line, and function where a qDebug, qWarning, qCritical
or qFatal call happens, and make this information available in a custom
message handler.

The patch uses the C preprocessor to replace qDebug, qWarning, ... with
a line that also records the current file, line, and function. Custom
message handlers can access this information via a new QMessageLogContext
argument.

Change-Id: I0a9b89c1d137e41775932d3b1a35da4ebf12d18d
Reviewed-by: David Faure <faure@kde.org>

1 files changed, 11 insertions, 6 deletions

diff --git a/doc/src/snippets/code/src_corelib_global_qglobal.cpp b/doc/src/snippets/code/src_corelib_global_qglobal.cpp
index a45a136255..21bea7aef8 100644
--- a/doc/src/snippets/code/src_corelib_global_qglobal.cpp
+++ b/doc/src/snippets/code/src_corelib_global_qglobal.cpp
@@ -246,27 +246,27 @@ const TInputType &myMin(const TInputType &value1, const TInputType &value2)
 #include <stdio.h>
 #include <stdlib.h>
 
-void myMessageOutput(QtMsgType type, const char *msg)
+void myMessageOutput(QtMsgType type, const QMessageLogContext &context, const char *msg)
 {
     switch (type) {
     case QtDebugMsg:
-        fprintf(stderr, "Debug: %s\n", msg);
+        fprintf(stderr, "Debug: %s (%s:%u, %s)\n", msg, context.file, context.line, context.function);
         break;
     case QtWarningMsg:
-        fprintf(stderr, "Warning: %s\n", msg);
+        fprintf(stderr, "Warning: %s (%s:%u, %s)\n", msg, context.file, context.line, context.function);
         break;
     case QtCriticalMsg:
-        fprintf(stderr, "Critical: %s\n", msg);
+        fprintf(stderr, "Critical: %s (%s:%u, %s)\n", msg, context.file, context.line, context.function);
         break;
     case QtFatalMsg:
-        fprintf(stderr, "Fatal: %s\n", msg);
+        fprintf(stderr, "Fatal: %s (%s:%u, %s)\n", msg, context.file, context.line, context.function);
         abort();
     }
 }
 
 int main(int argc, char **argv)
 {
-    qInstallMsgHandler(myMessageOutput);
+    qInstallMessageHandler(myMessageOutput);
     QApplication app(argc, argv);
     ...
     return app.exec();
@@ -532,6 +532,11 @@ class MyClass : public QObject
 CApaApplication *myApplicationFactory();
 //! [47]
 
+
+//! [49]
+void myMessageHandler(QtMsgType, const QMessageLogContext &, const char *);
+//! [49]
+
 //! [qlikely]
     // the condition inside the "if" will be successful most of the times
     for (int i = 1; i <= 365; i++) {