Matlab Engine Application with Qt

[stevosteve]

Hello everyone,

I am trying to create a Qt application that uses the Matlab engine to perform calculations and execute scripts.
My build system has the following parameters that I think are relevant :

Matlab 2017a
Ubuntu 16.04
gcc 5.4.0
Qt5.10.0

The application I am currently trying to compile is very simple

#include <QcoreApplication>
#include <QDebug>
#include "engine.h"
#include "matrix.h"

int main(int argc, char *argv[])
{
    Engine* m_engine;

    m_engine = engOpen("");

    if (!(m_engine = engOpen(""))) {
        qDebug()<<"\nCan't start MATLAB engine\n";
        exit(-1);
    }
}

The pro file I am using is the following :

QT -= gui

CONFIG += c++11
CONFIG -= app_bundle


MATLAB_ROOT_PATH = /usr/local/MATLAB/R2017a

MATLAB_INCLUDE_PATH = $${MATLAB_ROOT_PATH}/extern/include
MATLAB_LIB_PATH     = $${MATLAB_ROOT_PATH}/bin/glnxa64
MATLAB_SYS_DIR = $${MATLAB_ROOT_PATH}/sys/os/glnxa64

LIBS += -L$${MATLAB_LIB_PATH} -lmx -lmex -lmat -lm -leng
LIBS += -L$${MATLAB_SYS_DIR} -lstdc++

INCLUDEPATH += $$MATLAB_INCLUDE_PATH
DEPENDPATH  += $$MATLAB_INCLUDE_PATH

QMAKE_RPATHDIR += $$MATLAB_LIB_PATH
QMAKE_RPATHDIR += $$MATLAB_SYS_DIR

DEFINES += QT_DEPRECATED_WARNINGS
SOURCES += main.cpp

The above code compiles, but I get the following error during execution from both the Qt Creator and the system console :

./matlab_test: /usr/local/MATLAB/R2017a/bin/glnxa64/libQt5Core.so.5: no version information available (required by ./matlab_test)
./matlab_test: /usr/local/MATLAB/R2017a/bin/glnxa64/libQt5Core.so.5: no version information available (required by ./matlab_test)
./matlab_test: relocation error: ./matlab_test: symbol qt_version_tag, version Qt_5.10 not defined in file libQt5Core.so.5 with link time reference

I have looked into this problem for a while now and problem was that I received runtime error regarding the stdc++ library which was not the same as the compilers.

Replacing the linking to the stdc++ library with the following

LIBS += -L/usr/lib/x86_64-linux-gnu -lstdc++

results in the following compilation error :

g++ -c -pipe -O2 -std=gnu++11 -Wall -W -D_REENTRANT -fPIC -DQT_DEPRECATED_WARNINGS -DQT_NO_DEBUG -DQT_CORE_LIB -I../matlab_test -I. -I/usr/local/MATLAB/R2017a/extern/include -I../../../../Qt/5.10.0/gcc_64/include -I../../../../Qt/5.10.0/gcc_64/include/QtCore -I. -I../../../../Qt/5.10.0/gcc_64/mkspecs/linux-g++ -o main.o 
g++ -Wl,-O1 -Wl,-rpath,/home/stef/Qt/5.10.0/gcc_64/lib -Wl,-rpath,/usr/lib/x86_64-linux-gnu -Wl,-rpath,/usr/local/MATLAB/R2017a/bin/glnxa64 -Wl,-rpath,/usr/local/MATLAB/R2017a/sys/os/glnxa64 -Wl,-rpath,/home/stef/Qt/5.10.0/gcc_64/lib -o matlab_test main.o   -L/usr/local/MATLAB/R2017a/bin/glnxa64 -lmx -lmex -lmat -lm -leng -L/usr/lib/x86_64-linux-gnu -lstdc++ -L/home/stef/Qt/5.10.0/gcc_64/lib -lQt5Core -lpthread 
/usr/local/MATLAB/R2017a/bin/glnxa64/libmwi18n.so: undefined reference to `icu_56::UnicodeString::UnicodeString(char16_t const*, int)'
/usr/local/MATLAB/R2017a/bin/glnxa64/libmwi18n.so: undefined reference to `UCNV_FROM_U_CALLBACK_ESCAPE_WITH_INVISIBLE_CHARS_56'
/usr/local/MATLAB/R2017a/bin/glnxa64/libmwi18n.so: undefined reference to `UCNV_FROM_U_CALLBACK_STOP_WITH_INVISIBLE_CHARS_56'
/usr/local/MATLAB/R2017a/bin/glnxa64/libmwi18n.so: undefined reference to `icu_56::UnicodeString::UnicodeString(char16_t const*)'
/usr/local/MATLAB/R2017a/bin/glnxa64/libmwi18n.so: undefined reference to `icu_56::UnicodeString::doCompare(int, int, char16_t const*, int, int) const'
Makefile:244: recipe for target 'matlab_test' failed
collect2: error: ld returned 1 exit status
make: *** [matlab_test] Error 1
16:18:26: The process "/usr/bin/make" exited with code 2.
Error while building/deploying project matlab_test (kit: Desktop Qt 5.10.0 GCC 64bit)
When executing step "Make"

Mathworks states that they officially support gcc 4.9, but I think this is true when compiling from MATLAB directly. I have also tried compiling by linking the libraries in the Matlab folder to the system ones instead, but I get similar errors.

Anyone have any idea? Do you think it is a compiler issue? Do you think it could be solved by compiling Qt with gcc 4.9 and then trying again? Am I not linking the libraries correctly in the qmake .pro file?

Thank you for your time

PS : The ldd command on the executable when I can get it to compile gives me the following

linux-vdso.so.1 =>  (0x00007ffc42980000)
libeng.so => /usr/local/MATLAB/R2017a/bin/glnxa64/libeng.so (0x00007f992c48b000)
libstdc++.so.6 => /usr/local/MATLAB/R2017a/sys/os/glnxa64/libstdc++.so.6 (0x00007f992c178000)
libQt5Core.so.5 => /usr/local/MATLAB/R2017a/bin/glnxa64/libQt5Core.so.5 (0x00007f992ba41000)
libgcc_s.so.1 => /usr/local/MATLAB/R2017a/sys/os/glnxa64/libgcc_s.so.1 (0x00007f992b82b000)
libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007f992b449000)
libut.so => /usr/local/MATLAB/R2017a/bin/glnxa64/libut.so (0x00007f992b165000)
libmx.so => /usr/local/MATLAB/R2017a/bin/glnxa64/libmx.so (0x00007f992add3000)
libmat.so => /usr/local/MATLAB/R2017a/bin/glnxa64/libmat.so (0x00007f992ab78000)
libboost_system.so.1.56.0 => /usr/local/MATLAB/R2017a/bin/glnxa64/libboost_system.so.1.56.0 (0x00007f992a975000)
libmwcpp11compat.so => /usr/local/MATLAB/R2017a/bin/glnxa64/libmwcpp11compat.so (0x00007f992a757000)
libm.so.6 => /lib/x86_64-linux-gnu/libm.so.6 (0x00007f992a44d000)
libpthread.so.0 => /lib/x86_64-linux-gnu/libpthread.so.0 (0x00007f992a230000)
/lib64/ld-linux-x86-64.so.2 (0x000055e67200a000)
libz.so.1 => /lib/x86_64-linux-gnu/libz.so.1 (0x00007f992a016000)
libicui18n.so.56 => /usr/local/MATLAB/R2017a/bin/glnxa64/libicui18n.so.56 (0x00007f9929b8e000)
libicuuc.so.56 => /usr/local/MATLAB/R2017a/bin/glnxa64/libicuuc.so.56 (0x00007f99297f1000)
libicudata.so.56 => /usr/local/MATLAB/R2017a/bin/glnxa64/libicudata.so.56 (0x00007f9927e0b000)
libdl.so.2 => /lib/x86_64-linux-gnu/libdl.so.2 (0x00007f9927c06000)
librt.so.1 => /lib/x86_64-linux-gnu/librt.so.1 (0x00007f99279fe000)
libmwi18n.so => /usr/local/MATLAB/R2017a/bin/glnxa64/libmwi18n.so (0x00007f99276ac000)
libmwfl.so => /usr/local/MATLAB/R2017a/bin/glnxa64/libmwfl.so (0x00007f99272f9000)
libmwresource_core.so => /usr/local/MATLAB/R2017a/bin/glnxa64/libmwresource_core.so (0x00007f99270f7000)
libmwfoundation_usm.so => /usr/local/MATLAB/R2017a/bin/glnxa64/libmwfoundation_usm.so (0x00007f9926ed6000)
libboost_chrono.so.1.56.0 => /usr/local/MATLAB/R2017a/bin/glnxa64/libboost_chrono.so.1.56.0 (0x00007f9926ccf000)
libboost_date_time.so.1.56.0 => /usr/local/MATLAB/R2017a/bin/glnxa64/libboost_date_time.so.1.56.0 (0x00007f9926abe000)
libboost_filesystem.so.1.56.0 => /usr/local/MATLAB/R2017a/bin/glnxa64/libboost_filesystem.so.1.56.0 (0x00007f99268a8000)
libboost_log.so.1.56.0 => /usr/local/MATLAB/R2017a/bin/glnxa64/libboost_log.so.1.56.0 (0x00007f99265ca000)
libboost_regex.so.1.56.0 => /usr/local/MATLAB/R2017a/bin/glnxa64/libboost_regex.so.1.56.0 (0x00007f99262ba000)
libboost_thread.so.1.56.0 => /usr/local/MATLAB/R2017a/bin/glnxa64/libboost_thread.so.1.56.0 (0x00007f9926099000)
libexpat.so.1 => /usr/local/MATLAB/R2017a/bin/glnxa64/libexpat.so.1 (0x00007f9925e70000)
libicuio.so.56 => /usr/local/MATLAB/R2017a/bin/glnxa64/libicuio.so.56 (0x00007f9925c63000)
libtbb.so.2 => /usr/local/MATLAB/R2017a/bin/glnxa64/libtbb.so.2 (0x00007f9925a18000)
libtbbmalloc.so.2 => /usr/local/MATLAB/R2017a/bin/glnxa64/libtbbmalloc.so.2 (0x00007f99257c5000)
libboost_signals.so.1.56.0 => /usr/local/MATLAB/R2017a/bin/glnxa64/libboost_signals.so.1.56.0 (0x00007f99255af000)
libhdf5_hl.so.8 => /usr/local/MATLAB/R2017a/bin/glnxa64/libhdf5_hl.so.8 (0x00007f992537e000)
libhdf5.so.8 => /usr/local/MATLAB/R2017a/bin/glnxa64/libhdf5.so.8 (0x00007f9924eed000)
libcrypt.so.1 => /lib/x86_64-linux-gnu/libcrypt.so.1 (0x00007f9924cb4000)
libpam.so.0 => /lib/x86_64-linux-gnu/libpam.so.0 (0x00007f9924aa6000)
libboost_serialization.so.1.56.0 => /usr/local/MATLAB/R2017a/bin/glnxa64/libboost_serialization.so.1.56.0 (0x00007f9924846000)
libunwind.so.8 => /usr/local/MATLAB/R2017a/bin/glnxa64/libunwind.so.8 (0x00007f9924626000)
libssl.so.1.0.0 => /usr/local/MATLAB/R2017a/bin/glnxa64/libssl.so.1.0.0 (0x00007f99243b5000)
libcrypto.so.1.0.0 => /usr/local/MATLAB/R2017a/bin/glnxa64/libcrypto.so.1.0.0 (0x00007f9923f6e000)
libaudit.so.1 => /lib/x86_64-linux-gnu/libaudit.so.1 (0x00007f9923d46000)

[shwoods]

According to Mathworks "Build C++ Engine Programs" the following libraries should be used in Linux:

Linux Libraries
Engine library — matlabroot/extern/bin/glnxa64/libMatlabEngine.so
MATLAB Data Array library — matlabroot/extern/bin/glnxa64/libMatlabDataArray.so
Additional library — pthread

Could it be in your pro file you need to add extern to this path?

MATLAB_LIB_PATH = $${MATLAB_ROOT_PATH}/bin/glnxa64

[stevosteve]

@shwoods said in Matlab Engine Application with Qt:

libMatlabEngine

These libraries were included with MATLAB 2017b. The previous MATLAB versions use the engine.h and matrix.h.

I have been in contact with mathworks and as a first step towards solving the problem was to use Qt 5.5 while linking to the libstdc++.so located in the $$MATLAB_SYS_DIR. The problem then is that matlab engine does not start.

I will update you if I find more

[mrjj]

@stevosteve
Hi
You must likely have checked that but just in case.
Did you try LDD on libMatlabEngine to see if anything missing ?

[Sussi]

Hi stevosteve,

Just wondering if your problem solved? I am quite new to Qt and trying to call some Matlab functions, while I think I have the same issue as yours, do you have any idea where it went wrong?

Thank you very much,

Sussi