Suppress qDebug when using QTestLib - c++

I am adding unit tests to project in Qt and am looking to use QTestLib. I have set up the tests and they are running fine.
The issue is that in the project we have overridden qDebug() to output to our own log file. This works great when running the app, the problem is that when I am testing the classes, it will sometimes start logging, which is then sent to the output window. The result is a complete disaster that is next to impossible to read as our logs get mixed in with the QTest output.
I am wondering if there is a way to suppress the qDebug() output, or at least move it somewhere else. I have tried adding #define QT_NO_DEBUG_OUTPUT and also using qInstallMsgHandler(messageOutput); to redirect or prevent the output, but neither had any effect.

The solution given by #Kuba works in some cases, but not when used in conjunction with QTest::qExec(&test,argc,argv) in the main method to run a number of tests. In that case the only way to disable the qDebug() output (that I found) is for each of the test classes in their void initTestCase() slot to register a new message handler.
For example
void noMessageOutput(QtMsgType, const char *)
{}
int main(int argc,char* argv[])
{
qInstallMsgHandler(noMessageOutput);
tst_Class1 t1;
tst_Class2 t2;
QTest::qExec(&t1,argc,argv);
QTest::qExec(&t2,argc,argv);
}
Will show the debug output tst_Class1, Class1, tst_Class2, and Class2. To prevent this you must explicitly disable the output in each of the test classes
class tst_Class1
{
//class stuff
private slots:
void initTestCase();
//test cases
};
void tst_Class1::initTestCase()
{
qInstallMsgHandler(noMessageOutput);
}
class tst_Class2
{
//class stuff
private slots:
void initTestCase();
//test cases
};
void tst_Class2::initTestCase()
{
qInstallMsgHandler(noMessageOutput);
}
If you wish to see the debug output from a subset of the classes the remove the qInstallMsgHandler() line and it will come through.

The QT_NO_DEBUG_OUTPUT define must go into your project files or makefiles and must be present for every file you compile. You must then recompile your application (not Qt itself of course). This macro's presence on compiler's command line guarantees that the first time QDebug header is included by any code, the qDebug will be redefined to a no-op. That's what this macro does: it disables qDebug if it is present when the <QtCore/qdebug.h> header gets included -- whether directly by you or indirectly by other headers.
Using qInstallMsgHandler certainly works at suppressing debug output.
Below is a self-contained example.
#if 0
// Enabling this section disables all debug output from non-Qt code.
#define QT_NO_DEBUG_OUTPUT
#endif
#include <QtCore/QDebug>
void noMessageOutput(QtMsgType, const char *)
{}
int main(int argc, char *argv[])
{
qDebug() << "I'm shown";
qInstallMsgHandler(noMessageOutput);
qDebug() << "I'm hidden";
}

Related

Debug Assertion Failed Expression __acrt_first_block == header

I have been trying to figure out why this is happening and maybe it is just due to inexperience at this point but could really use some help.
When I run my code, which is compiled into a DLL using C++20, I get that a debug assertion has failed with the expression being __acrt_first_block == header.
I narrowed down where the code is failing, but the weird part is that it runs just fine when I change the Init(std::string filePath function signature to not contain the parameter. The code is below and hope someone can help.
Logger.h
#pragma once
#include "../Core.h"
#include <memory>
#include <string>
#include "spdlog/spdlog.h"
namespace Ruby
{
class RUBY_API Logger
{
public:
static void Init(std::string filePath);
inline static std::shared_ptr<spdlog::logger>& GetCoreLogger() { return coreLogger; }
inline static std::shared_ptr<spdlog::logger>& GetClientLogger() { return clientLogger; }
private:
static std::shared_ptr<spdlog::logger> coreLogger;
static std::shared_ptr<spdlog::logger> clientLogger;
};
}
Logger.cpp
namespace Ruby
{
std::shared_ptr<spdlog::logger> Logger::coreLogger;
std::shared_ptr<spdlog::logger> Logger::clientLogger;
void Logger::Init(std::string filePath)
{
std::string pattern{ "%^[%r][%n][%l]: %v%$" };
auto fileSink = std::make_shared<spdlog::sinks::basic_file_sink_mt>(filePath, true);
// Setup the console and file sinks
std::vector<spdlog::sink_ptr> coreSinks;
coreSinks.push_back(std::make_shared<spdlog::sinks::stdout_color_sink_mt>());
coreSinks.push_back(fileSink);
// Bind the sinks to the core logger.
coreLogger = std::make_shared<spdlog::logger>("RUBY", begin(coreSinks), end(coreSinks));
// Set the Patterns for the sinks
coreLogger->sinks()[0]->set_pattern(pattern);
coreLogger->sinks()[1]->set_pattern(pattern);
// Tell spdlog to flush the file loggers on trace or worse message (can be changed if necessary).
coreLogger->flush_on(spdlog::level::trace);
// Set the default level of the logger
coreLogger->set_level(spdlog::level::trace);
// Do the same for the client logger
std::vector<spdlog::sink_ptr> clientSinks;
clientSinks.push_back(std::make_shared<spdlog::sinks::stdout_color_sink_mt>());
clientSinks.push_back(fileSink);
clientLogger = std::make_shared<spdlog::logger>("APP", begin(clientSinks), end(clientSinks));
clientLogger->sinks()[0]->set_pattern(pattern);
clientLogger->sinks()[1]->set_pattern(pattern);
clientLogger->flush_on(spdlog::level::trace);
clientLogger->set_level(spdlog::level::trace);
}
}
Entrypoint.h
#pragma once
#ifdef RB_PLATFORM_WINDOWS
extern Ruby::Application* Ruby::CreateApplication();
int main(int argc, char** argv)
{
Ruby::Logger::Init("../Logs/Recent_Run.txt");
RB_CORE_INFO("Initialized the logger.");
auto app = Ruby::CreateApplication();
app->Run();
delete app;
return 0;
}
#else
#error Ruby only supports windows
#endif // RB_PLATFORM_WINDOWS
For anyone else who runs into a similar problem, here is how I fixed it.
Essentially the function signature for the Init() function was the problem. The std::string parameter was causing the debug assertion to fire, my best guess as of right now was because of move semantics but that part I am still not sure on. So there are a couple of ways that I found to fix this.
Method 1:
Make the parameter a const char*. I don't quite like this approach as it then relies on C style strings and if you are trying to write a program in modern C++, this is a huge step backwards.
Method 2:
Make the parameter a const std::string&. Making it a const reference to a string prevents the move semantics (again as far as I know) and the assertion no longer fires. I prefer this fix as it keeps the program in modern C++.
I hope this helps anyone who has similar issues, and be careful with statics and move semantics.

"Field is never used" although its (field's) constructor runs

class SdlManager
{
public:
SdlManager();
~SdlManager();
};
class Application
{
SdlManager sdlManager;
Screen screen;
EventHandler eventHandler;
bool running = true;
int fps = Fps;
void Draw();
public:
Application();
void Run();
void Stop();
};
int main(int argc, char* argv[])
{
Application app;
app.Run();
return 0;
}
Hi. I'm toying with SDL using Clion and I noticed this warning which seems strange: it complains that the field sdlManager is never used, but I'm sure (even using breakpoints) that the program runs sdlManager's constructor when I instantiate an Application object inside main.
What should I do? Is it a Clion's (or whatever plugin it uses) bug?
sdlManager is constructed, but it's never used after that. That's why you're getthing the warning.
Once you'll add methods to it, and start using them, the warning will go away.
The point of that warning is to signal code that isn't used anywhere in the code, either someone forgot to use it, or it needs to be removed (after some refactoring or something).

Suppose I have a completely functioning program and I want to attach a test file how do I run it without adding h files to my program?

I am a little bit new to cpp. And all the concepts of 'includes' tho are important are pretty new and vague forme. I have a few questions which are related to my main question . The main question is:. I have a program which is a file containing 'main' and other 5 classes let's call it 'PROG'. I put them all in one file using no h files at all. The program is running and all is good. The point is, I now have 'test file ' which should test my program. Test file is separated to h file and cpp file. Is there any way to run everything without changing my program 'PROG'?? I don't want to create h files to my 'PROG' . The problem is, the test file uses a few of the claseess written the program 'PROG'. I thought about writing 'includes' cpp in the test file and putting 'pragma once'. I don't know why it doesn't work. Doesn't pragma once work for ' cpp includes'??
Or basically can anyone answer the general question. Which is in short:. You have a file containing main and classes (which all in cpp file with no h file) . And you want to run it with another file (cpp+ h) but both files use each othrr. Which makes a circular use. Is there a way to run it ?
You might be able to write tests, however they will be run at an unspecified time either before or after your program runs, so won't be able to access std::cout etc. If your program uses any static objects, you won't be able to do this.
It will be much easier to move your main into a main.cpp that #includes definitions of your classes, and compile a separate test_main.cpp that instead runs your tests.
As a sketch of the former
class TestFailure{};
class RunAtStartup
{
template<typename Func>
RunAtStartup(Func f) { f(); }
}
extern double function_to_test(int arg);
static RunAtStartup run_function_to_test([]{
// arrange
int param = 0;
// act
double res = function_to_test(param);
// assert
if(res != 1.0) throw TestFailure();
});
Does this help?
PROG:
class C {
void f();
}
#ifndef TEST
void C::f() {
// implementation
}
#endif // TEST
TEST:
#define TEST
#include "main.cpp"
// Your test code here can have instances to class C
C c;
c.f();
But take cpp/h approach as anyone recommends, which is everywhere.
I'd highly recommend using headers, but if you really don't want to modify your original file, you can #include "main.cpp" from your test file and redefine the main symbol during the inclusion. This allows you to create your own main method for the test program.
In test.cpp:
#define main real_main
#include "mymain.cpp"
#undef main
int main(int argc, const char** argv) {
std::cout << "wah" << std::endl;
int fakeargc = 1;
const char* fakeargv[fakeargc] = { "hoo" };
real_main(fakeargc, fakeargv);
}
In main.cpp:
#include <iostream>
int main(int argc, const char** argv) {
std::cout << "hello world " << argv[0] << std::endl;
return 0;
}

How to use a global variable for "configurations" in multiple tests in Googletest framework

I am using Google test framework for C++. Each file includes a config.hpp which defined a global configuration variable. I would like to define my config in a variable, not a compile-time const or constexpr. How can I define the dependencies to have the same variable in different files that are linked together? Do I have to use a singleton? Can I avoid that? Is there a better recommended way to use multiple test files xUnit style?
My config file: config.hpp:
#pragma once
struct {
const float tolerance = 0.001;
// ...
} CONFIG_VAR;
Each test *.cpp source file is like:
#include "gtest/gtest.h"
#include "core/config.hpp"
TEST(a, b) { ... }
My main file:
#include "gtest/gtest.h"
int main(int argc, char **argv) {
::testing::InitGoogleTest(&argc, argv);
return RUN_ALL_TESTS();
}
I compile and link using:
em++ -I $GTEST_ROOT/googletest/include main_all_tests.cpp test_*.cpp
PS. My problem is multiple definition of the variable CONFIG_VAR.
My solution is based on a related question.
Everything you need is right here at the Google Test's official repository on GitHub.
Anyway, to sharing something in the same file test you do it like that:
class YourTestCase : public ::testing::Test
{
protected:
virtual void SetUp()
{
globalObject = new YourObject();
}
virtual void TearDown() {
delete globalObject;
globalObject = nullptr;
}
Object * globalObject = nullptr;
};
so, in your test cases:
TEST_F(YourTestCase, TestOne) {
ASSERT_EQ("your value here", globalObject->getValue());
}
TEST_F(YourTestCase, TestTwo) {
ASSERT_EQ("your value here", globalObject->getValue());
}
TEST_F(YourTestCase, TestThree) {
ASSERT_EQ("your value here", globalObject->getValue());
}
Note.: Pay attention to the function's name. It is TEST_F not TEST.
On the other hand, if what you want to do it is at the test program level ― sharing something among files, you will need to set up an environment object. Something like this:
Environment * AddGlobalTestEnvironment(Environment * env);
I have never worked with that before, so I can not tell you so much about it, but there is more information at that link I shared above. Usually, global variables make the code harder to read and may cause problems. You'd be better off avoiding them.

how do I set a debug mode in c++

I would like to set a debug mode so that it prints the log statements only if the debug mode is on. For example if I have code like this
printf("something \n");
.
.
.
perror("something \n");
It only works if the debug flag is on.. I don't want to use "if" statements.
I think there is a clever way to do this using #define or something..
Thank is advance..
#ifdef _DEBUG // or #ifndef NDEBUG
#define LOG_MSG(...) printf(__VA_ARGS__) // Or simply LOG_MSG(msg) printf(msg)
#else
#define LOG_MSG(...) // Or LOG_MSG(msg)
#endif
On non-Debug built LOG_MSG would yeild to nothing. Instead of defining it with raw printf, you can have your custom logging-function, or class-method to be called.
Without going in to specific libraries or solutions, generally people make a logger class or function, and a single debug flag. The debug function checks this flag before calling printf or cout. Then in the rest of your code you simply call your debug function / method.
Here's an example:
class MyDebugger
{
private:
bool m_debug;
public:
MyDebugger();
void setDebug(bool debug);
void debug(const char* message);
};
MyDebugger::MyDebugger()
{
m_debug = false;
}
void MyDebugger::setDebug(bool debug)
{
m_debug = debug;
}
void MyDebugger::debug(const char* message)
{
if(m_debug)
{
cout << message << endl;
}
}
int main(int argc, char** argv)
{
MyDebugger debugger;
debugger.debug("This won't be shown");
debugger.setDebug(true);
debugger.debug("But this will");
return 0;
}
of course this is an incredibly naive implementation. In real logger classes there are many levels for finer-grained control of how much detail gets printed (levels like error, warning, info, and debug to differentiate the importance of the message). They might also let you log to files as well as stdout. Still this should give you a general idea.
In GCC, something like
#define debugprint(...) printf(__VA_ARGS__)
You can do a simple C-style macro definition (especially if you compiler is modern enough to do variable arguments macros, i.e. gcc or VS2005+) doing printf with a check of the debug level which can be a static global variable.
If you go with C++-style class similar to what #Chris suggests, I would make the logging function inline to ensure that when logging is disabled you are not wasting time on calling functions.