CUDA and QT create library

Kyll

Hello i try to use CUDA with QT and get some errors.
This example work fine:
main.cpp

extern "C" void runKernel();
#include <cstdio>
int main(int argc, char **argv)
{
	runKernel();
	printf("Kernel passed \n");
	return 0;
}

MWE.cu

#include <cstdio>

__global__ void testKernel()
{
}

extern "C" void runKernel()
{
	testKernel<<<1,1>>>();
	printf("\n Kernel pass \n");
}

Build instructions

    nvcc -ccbin g++ -m64 -arch=sm_50 -dc -o MWE.o -c MWE.cu
    nvcc -ccbin g++ -m64 -arch=sm_50 -dlink -o MWE.dlink.o MWE.o
    nvcc -ccbin g++ -m64 -arch=sm_50 -lib -o MWE.a MWE.o MWE.dlink.o
    g++ -m64 -o main.o -c main.cpp
    g++ -m64 main.o MWE.a -o test -L/usr/local/cuda/lib64 -lcudart

So okay I get library MWE.a and can compile with main.cpp using g++, I try to create new library with previous one MWE.a
KL.pro

#-------------------------------------------------
#
# Project created by QtCreator 2019-03-18T19:09:38
#
#-------------------------------------------------
TEMPLATE = lib
CONFIG -= qt
CONFIG += console
CONFIG -= app_bundle
CONFIG += c++11
INCLUDEPATH += home/kyll/Documents/CUDATEST/LAST
LIBS += -L/home/kyll/Documents/CUDATEST/LAST/MWE.a
# The following define makes your compiler emit warnings if you use
# any feature of Qt which has been marked as deprecated (the exact warnings
# depend on your compiler). Please consult the documentation of the
# deprecated API in order to know how to port your code away from it.
DEFINES += QT_DEPRECATED_WARNINGS

# You can also make your code fail to compile if you use deprecated APIs.
# In order to do so, uncomment the following line.
# You can also select to disable deprecated APIs only up to a certain version of Qt.
#DEFINES += QT_DISABLE_DEPRECATED_BEFORE=0x060000    # disables all the APIs deprecated before Qt 6.0.0

SOURCES += \
        kl.cpp

HEADERS += \
    kl.h

CONFIG(debug, debug|release) {
    # debug
    unix: {
        QMAKE_LFLAGS = -fopenmp
        QMAKE_CXXFLAGS += -m64 -flto -march=native -funroll-loops -fopenmp
    } else {
        QMAKE_LFLAGS = -fopenmp
        QMAKE_CXXFLAGS += -fopenmp
    }
} else {
    # release
    unix: {
        QMAKE_LFLAGS = -fopenmp
        QMAKE_CXXFLAGS += -Ofast -m64 -flto -march=native -funroll-loops -fopenmp
    } else {
        QMAKE_LFLAGS = -fopenmp
        QMAKE_CXXFLAGS += -Ofast -flto -march=native -funroll-loops -fopenmp
    }
}

CONFIG (debug, debug|release) {
    OBJECTS_DIR = debug
} else {
    OBJECTS_DIR = release
}

kl.h

#ifndef KL_H
#define KL_H

extern "C" void runKernel();
extern "C" void f();

#endif // KL_H

kl.cpp

#include <cstdio>
#include "kl.h"
void runKernel();
void f()
{
    runKernel();
    printf("Test \n");
}

MinGW generating library .so , .so.1 , .so.1.0, .so.1.0.0, I use .so in my app and get errors:
:-1: error: /tmp/ccCGR1vb.ltrans0.ltrans.o: in function `main':
:-1: error: collect2: error: ld returned 1 exit status

LM.pro

#-------------------------------------------------
#
# Project created by QtCreator 2019-03-18T19:09:38
#
#-------------------------------------------------
TEMPLATE = app
CONFIG -= qt
CONFIG += console
CONFIG -= app_bundle
CONFIG += c++11
INCLUDEPATH += /home/kyll/Documents/CUDATEST/LAST/build-KL-Desktop_Qt_5_10_0_GCC_64bit-Debug
LIBS += -L/home/kyll/Documents/CUDATEST/LAST/build-KL-Desktop_Qt_5_10_0_GCC_64bit-Debug/libKL.so
# The following define makes your compiler emit warnings if you use
# any feature of Qt which has been marked as deprecated (the exact warnings
# depend on your compiler). Please consult the documentation of the
# deprecated API in order to know how to port your code away from it.
DEFINES += QT_DEPRECATED_WARNINGS

# You can also make your code fail to compile if you use deprecated APIs.
# In order to do so, uncomment the following line.
# You can also select to disable deprecated APIs only up to a certain version of Qt.
#DEFINES += QT_DISABLE_DEPRECATED_BEFORE=0x060000    # disables all the APIs deprecated before Qt 6.0.0

SOURCES += \
        lm.cpp
HEADERS += \
    lm.h

CONFIG(debug, debug|release) {
    # debug
    unix: {
        QMAKE_LFLAGS = -fopenmp
        QMAKE_CXXFLAGS += -m64 -flto -march=native -funroll-loops -fopenmp
    } else {
        QMAKE_LFLAGS = -fopenmp
        QMAKE_CXXFLAGS += -fopenmp
    }
} else {
    # release
    unix: {
        QMAKE_LFLAGS = -fopenmp
        QMAKE_CXXFLAGS += -Ofast -m64 -flto -march=native -funroll-loops -fopenmp
    } else {
        QMAKE_LFLAGS = -fopenmp
        QMAKE_CXXFLAGS += -Ofast -flto -march=native -funroll-loops -fopenmp
    }
}

CONFIG (debug, debug|release) {
    OBJECTS_DIR = debug
} else {
    OBJECTS_DIR = release
}

lm.h

#ifndef LM_H
#define LM_H

extern "C" void runKernel();
extern "C" void f();

#endif // LM_H

lm.cpp

#include <cstdio>
#include "lm.h"
int main(){
    runKernel();
    //f();
    return 0;
}

What I misunderstand? Where error?

SGaist

Hi and welcome to devnet,

-L is for giving an additional search path to the linker.

You need to use -l (lowercase L) to give an additional library to use to the linker.

Kyll

I change few lines in KL.pro:

INCLUDEPATH += home/kyll/Documents/CUDATEST/LAST
LIBS += -L/home/kyll/Documents/CUDATEST/LAST -lMWE

add -l and name of library and get errors
:-1: error: cannot find -lMWE
:-1: error: collect2: error: ld returned 1 exit status

Kyll

Add external library using project -> add library (recompile with new name lib*.a)

unix:!macx: LIBS += -L$$PWD/../ -lMWE

INCLUDEPATH += $$PWD/../
DEPENDPATH += $$PWD/../

unix:!macx: PRE_TARGETDEPS += $$PWD/../libMWE.a

Now get new errors:
:-1: error: /home/kyll/Documents/CUDATEST/LAST/KL/..//libMWE.a(MWE.o): relocation R_X86_64_PC32 against symbol `_Z10testKernelv' can not be used when making a shared object; recompile with -fPIC
:-1: error: final link failed: bad value
:-1: error: collect2: error: ld returned 1 exit status

Recompile with -fPIC all work.(Can build library in library)
But try to use this library in LM.pro I get errors
:-1: error: /tmp/ccB1sXku.ltrans0.ltrans.o: in function `main':
:-1: error: collect2: error: ld returned 1 exit status

SGaist

Are you using a self-built Qt version ?

Kyll

@SGaist I install qt (opensource version) from maintenance tool.

SGaist

How did you add -fPIC to your library build ?

Kyll

@SGaist I added -fPIC in KL.pro in QMAKE_LFLAGS and QMAKE_CXXFLAGS in #release -> else.

Kyll

Okay I can make this:
main.cpp

extern "C" void runKernel();
#include <cstdio>
int main(int argc, char **argv)
{
	runKernel();
	printf("Kernel passed\n");
	return 0;
}

MWE.cu

#include <cstdio>

__global__ void testKernel()
{
}

extern "C" void runKernel()
{
	testKernel<<<1,1>>>();
	printf("\nKernel pass \n");
}

Build

nvcc -ccbin g++ -m64 -arch=sm_50 --compiler-options '-fPIC' -dc -o MWE.o -c MWE.cu
nvcc -ccbin g++ -m64 -arch=sm_50 --compiler-options '-fPIC' -dlink -o MWE.dlink.o MWE.o
nvcc -ccbin g++ -m64 -arch=sm_50 --compiler-options '-fPIC' -lib -o libMWE.a MWE.o MWE.dlink.o

KL.pro

TEMPLATE = lib
CONFIG -= qt
CONFIG += console
CONFIG -= app_bundle
CONFIG += c++11
DEFINES += QT_DEPRECATED_WARNINGS
CUDA_DIR      = /usr/local/cuda-10.1
INCLUDEPATH  += $$CUDA_DIR/include
QMAKE_LIBDIR += $$CUDA_DIR/lib64
LIBS += -L$$CUDA_DIR/lib64 -lcudart -lcuda

SOURCES += \
        kl.cpp

CONFIG(debug, debug|release) {
    # debug
    unix: {
        QMAKE_LFLAGS = -fopenmp
        QMAKE_CXXFLAGS += -m64 -flto -march=native -funroll-loops -fopenmp
    } else {
        QMAKE_LFLAGS = -fopenmp
        QMAKE_CXXFLAGS += -fopenmp
    }
} else {
    # release
    unix: {
        QMAKE_LFLAGS = -fopenmp
        QMAKE_CXXFLAGS += -Ofast -m64 -flto -march=native -funroll-loops -fopenmp
    } else {
        QMAKE_LFLAGS = -fopenmp
        QMAKE_CXXFLAGS += -Ofast -flto -march=native -funroll-loops -fopenmp
    }
}

CONFIG (debug, debug|release) {
    OBJECTS_DIR = debug
} else {
    OBJECTS_DIR = release
}

unix:!macx: LIBS += -L$$PWD/../ -lMWE

INCLUDEPATH += $$PWD/../
DEPENDPATH += $$PWD/../

unix:!macx: PRE_TARGETDEPS += $$PWD/../libMWE.a

KL.cpp

#include <cstdio>
extern "C" void runKernel();
extern "C" void f()
{
    runKernel();
    printf("Test \n");
}

LM.pro

TEMPLATE = app
CONFIG -= qt
CONFIG += console
CONFIG -= app_bundle
CONFIG += c++11
DEFINES += QT_DEPRECATED_WARNINGS
CUDA_DIR      = /usr/local/cuda-10.1
INCLUDEPATH  += $$CUDA_DIR/include
QMAKE_LIBDIR += $$CUDA_DIR/lib64
LIBS += -L$$CUDA_DIR/lib64 -lcudart -lcuda
SOURCES += \
        lm.cpp

CONFIG(debug, debug|release) {
    # debug
    unix: {
        QMAKE_LFLAGS = -fopenmp
        QMAKE_CXXFLAGS += -m64 -flto -march=native -funroll-loops -fopenmp
    } else {
        QMAKE_LFLAGS = -fopenmp
        QMAKE_CXXFLAGS += -fopenmp
    }
} else {
    # release
    unix: {
        QMAKE_LFLAGS = -fopenmp
        QMAKE_CXXFLAGS += -Ofast -m64 -flto -march=native -funroll-loops -fopenmp
    } else {
        QMAKE_LFLAGS = -fopenmp
        QMAKE_CXXFLAGS += -Ofast -flto -march=native -funroll-loops -fopenmp
    }
}

CONFIG (debug, debug|release) {
    OBJECTS_DIR = debug
} else {
    OBJECTS_DIR = release
}

unix:!macx: LIBS += -L$$PWD/../build-KL-Desktop_Qt_5_10_0_GCC_64bit-Release/ -lKL
INCLUDEPATH += $$PWD/../build-KL-Desktop_Qt_5_10_0_GCC_64bit-Release
DEPENDPATH += $$PWD/../build-KL-Desktop_Qt_5_10_0_GCC_64bit-Release

LM.cpp

#include <cstdio>
extern "C" void runKernel();
extern "C" void f();
int main(){
    runKernel();
    f();
    return 0;
}