From f08704330df1ffbaba5ee78215e5d65f4fb94e1e Mon Sep 17 00:00:00 2001 From: Kevin Funk Date: Mon, 11 Oct 2021 14:31:01 +0200 Subject: qtlogging: Document QT_MESSAGELOGCONTEXT define Document it here to let people know about the pitfalls with some placeholder values. Link the QMessageLogContext class doc for more information. Pick-to: 6.2 Change-Id: I8e7b4c0dcb8bceeeee645664c98e63ae7ca7e854 Reviewed-by: Thiago Macieira Reviewed-by: Giuseppe D'Angelo --- src/corelib/global/qlogging.cpp | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/src/corelib/global/qlogging.cpp b/src/corelib/global/qlogging.cpp index cbb9e1963c..fd38a9d6c4 100644 --- a/src/corelib/global/qlogging.cpp +++ b/src/corelib/global/qlogging.cpp @@ -2021,13 +2021,17 @@ void qErrnoWarning(int code, const char *msg, ...) environment variable; if both \l qSetMessagePattern() is called and QT_MESSAGE_PATTERN is set, the environment variable takes precedence. + \note The information for the placeholders \c category, \c file, \c function and \c line is + only recorded in debug builds. Alternatively, \c QT_MESSAGELOGCONTEXT can be defined + explicitly. For more information refer to the QMessageLogContext documentation. + \note The message pattern only applies to unstructured logging, such as the default \c stderr output. Structured logging such as systemd will record the message as is, along with as much structured information as can be captured. Custom message handlers can use qFormatLogMessage() to take \a pattern into account. - \sa qInstallMessageHandler(), {Debugging Techniques}, {QLoggingCategory} + \sa qInstallMessageHandler(), {Debugging Techniques}, {QLoggingCategory}, QMessageLogContext */ QtMessageHandler qInstallMessageHandler(QtMessageHandler h) -- cgit v1.2.3