Index Qt5 in Eclipse IDE project using Cmake

Question

Background

I'm currently using Eclipse Neon.3 and have installed the "C/C++ CMake Build Support - Experimental" package (I'm not using CMake's Eclipse generator). I have a simple program that uses Qt 5.8 which builds successfully, however, Eclipse seems unable to index Qt symbols(e.g. QCoreApplication, QDebug, etc...).

The symptoms of this are:

• No code completion suggestions
• #include <QtCore> and other include statements are shown as unresolved
• Qt symbols such as QCoreApplication, QDebug(), and QCoreApplication.exec() are shown as not resolved.

Code

CMakeLists.txt file

cmake_minimum_required(VERSION 3.5)
project(test-program)

set(CMAKE_CXX_STANDARD 11)

# Put the CMake files for Qt5 in the Prefix path.
set(Qt5_DIR /opt/Qt/5.8/gcc_64/lib/cmake/Qt5/)

#Find includes in corresponding build directories
set(CMAKE_INCLUDE_CURRENT_DIR ON)

#Instruct CMake to run moc automatically when needed.
set(CMAKE_AUTOMOC ON)

#Find the Qt5Core Library
find_package(Qt5 REQUIRED COMPONENTS Core Widgets)

set(SOURCE_FILES
    src/main.cpp)

add_executable(${PROJECT_NAME} ${SOURCE_FILES})

target_link_libraries(${PROJECT_NAME} Qt5::Core) 

main.cpp (shown with eclipse annotations)

#include <QtCore> //Unresolved inclusion: <QtCore>
#include <QDebug> //Unresolved inclusion: <QDebug>

int main(int argc, char** argv){
    QCoreApplication application(argc, argv); 
    //Type 'QCoreApplication' could not be resolved 

    qDebug() << "Test";
    //Function 'qDebug' could not be resolved

    application.exec();
    //Method 'exec' could not be resolved

    return 0;
}

Question

So my question is this: How can I get Eclipse to recognize Eclipse to recognize Qt symbols? Or is that just not possible at this time?

Answer 1

Did you enable the "CDT GCC Build Output Parser"? This is an Eclipse feature to parse the output of the build and guesses the include paths automatically. You can find it unter Project Properties->C/C++ General->Preprocessor Include Paths, Macros etc. and then under the tab Providers.

In order for this feature to work properly, a detailed build report must be generated. You can achieve this by either changing the build command under Preferences->C/C++ Build to make VERBOSE=1 or by specifying set(CMAKE_VERBOSE_MAKEFILE On) inside your CMakeLists.txt.

See also Eclipse Help - Scanner Discovery Preferences