qSetMessagePattern("%{file}(%{line}): %{message}") output "unkown(0)"

Question

I'm using qSetMessagePattern to format the output.

The weird thing is even I set %{file} and %{line}, I could only get unknown and 0 in my output. And so does the %{function}. The source and output are below:

qSetMessagePattern("%{file}(%{line}): %{message}");
qDebug() << "msg";

output:

unknown(0): msg

Any ideas? Thanks!

I think so. I use `install(TARGETS my_exe DESTINATION ${install_dir} CONFIGURATIONS Debug)` in CMakeLists.txt and `make install` to install my executable file. — Qi W., May 02 '16 at 12:26

score 2 · Answer 1 · answered Jul 28 '16 at 08:45

2

add DEFINES += QT_MESSAGELOGCONTEXT to your xxx.pro, and then, rebuild

make clean && make distclean && qmake && make

I hope this could help you.

answered Jul 28 '16 at 08:45

Jiahao

76
1
7

He's using CMake. This advice is still sound, but notice that there's a good reason for stripping out source information in release builds (they leak information about your application) – peppe Jul 28 '16 at 08:48
Thanks for your reminder, It is CPPFLAGS in qmake. So add set(CMAKE_CXX_FLAGS "-DQT_MESSAGELOGCONTEXT") in CMake – Jiahao Jul 28 '16 at 10:03

score 2 · Answer 2 · answered Apr 21 '17 at 18:37

2

Try to add for the target you build:

target_compile_definitions(${PROJECT_NAME} PRIVATE -DQT_DEBUG -DQT_MESSAGELOGCONTEXT)

Seems -DQT_DEBUG has priority when used along with -DQT_NO_DEBUG.

answered Apr 21 '17 at 18:37

Tomilov Anatoliy

15,657
10
64
169

ephemerr · Answer 3 · 2018-04-09T10:24:32.537

I used this hint https://stackoverflow.com/a/24012195/2656799 to bypass the problem. In qlogging.h (see there) you can see how debug macros defined:

#define qDebug QMessageLogger(QT_MESSAGELOG_FILE, QT_MESSAGELOG_LINE, QT_MESSAGELOG_FUNC).debug
#define qInfo QMessageLogger(QT_MESSAGELOG_FILE, QT_MESSAGELOG_LINE, QT_MESSAGELOG_FUNC).info
#define qWarning QMessageLogger(QT_MESSAGELOG_FILE, QT_MESSAGELOG_LINE, QT_MESSAGELOG_FUNC).warning
#define qCritical QMessageLogger(QT_MESSAGELOG_FILE, QT_MESSAGELOG_LINE, QT_MESSAGELOG_FUNC).critical
#define qFatal QMessageLogger(QT_MESSAGELOG_FILE, QT_MESSAGELOG_LINE, QT_MESSAGELOG_FUNC).fatal

So my solution is to redefine them using standard file, line context macros:

#define logDebug    QMessageLogger(__FILE__,__LINE__, QT_MESSAGELOG_FUNC).debug
#define logInfo     QMessageLogger(__FILE__,__LINE__, QT_MESSAGELOG_FUNC).info
#define logWarning  QMessageLogger(__FILE__,__LINE__, QT_MESSAGELOG_FUNC).warning
#define logCritical QMessageLogger(__FILE__,__LINE__, QT_MESSAGELOG_FUNC).critical
#define logFatal    QMessageLogger(__FILE__,__LINE__, QT_MESSAGELOG_FUNC).fatal

qSetMessagePattern("%{file}(%{line}): %{message}") output "unkown(0)"

3 Answers3