Can't use C++11 features when building with Qt - macos

I'm on OS X 10.8.4 (Mountain Lion) with the latest command line tools from Xcode. I'm trying to build a Qt project (in Qt Creator) which uses some C++11 features; notably std::unique_ptr. Whenever I try building though, I get the following error:
clang: error: invalid deployment target for -stdlib=libc++ (requires OS X 10.7 or later)
My .pro file is as follows:
QT += core gui
QMAKE_CXXFLAGS += -mmacosx-version-min=10.7 -std=c++11 -stdlib=libc++
LIBS += -mmacosx-version-min=10.7 -stdlib=libc++
greaterThan(QT_MAJOR_VERSION, 4): QT += widgets
TARGET = APPNAME
TEMPLATE = app
SOURCES += main.cpp\
mainwindow.cpp
HEADERS += mainwindow.h
FORMS += mainwindow.ui
cache()
I've tried the solutions presented in other answers (see here and the top answer here), neither of which seemed to work.

According to this site add
CONFIG += c++11
to your .pro file (see at the bottom of that web page). It requires Qt 5.
UPDATE: As for Qt 4, see How to enable C++11 in Qt Creator?

Related

including protobuf3 headers in Qt project on Mac

as the title indicates, I am trying to compile a simple project in Qt that makes use of the addressbook.pb.h/addressbook.pb.cc files that are generated in the google protobuf3 tutorial for C++ users. Here is my .pro file
#-------------------------------------------------
#
# Project created by QtCreator 2016-11-07T10:33:12
#
#-------------------------------------------------
QT += core gui
greaterThan(QT_MAJOR_VERSION, 4): QT += widgets
TARGET = prototest
TEMPLATE = app
SOURCES += main.cpp\
mainwindow.cpp \
../protobuf/examples/addressbook.pb.cc
HEADERS += mainwindow.h \
../protobuf/examples/addressbook.pb.h
FORMS += mainwindow.ui
INCLUDEPATH += /usr/local/Cellar/protobuf/3.1.0/include
LIBS += /usr/local/Cellar/protobuf/3.1.0
Unfortunately, this throws
:-1: error: can't map file, errno=22 file '/usr/local/Cellar/protobuf/3.1.0' for architecture x86_64
I'm stuck at this point. Any help would be greatly appreciated. I have been able to compile and run the exact same (addressbook.*) files using Xcode8.
Solved it: Add the following to the .pro file
macx: LIBS += -L$$PWD/../../../usr/local/Cellar/protobuf/3.1.0/lib/ -lprotobuf.11
INCLUDEPATH += $$PWD/../../../usr/local/Cellar/protobuf/3.1.0/include
DEPENDPATH += $$PWD/../../../usr/local/Cellar/protobuf/3.1.0/include
I should add how I arrived at this answer. Right click your project and select "Add Library->External Library", select your platform and enter your specific library (not path) that you want to add, and your include path (the options it gives you indicate such). Qt will generate the code and automatically add it to your .pro file.

OpenCV libraries not found in Qt5 on OSX 10.10

I am currently trying to use OpenCV in a Qt project. When I build it, i get the error:
error: 'opencv2/opencv.hpp' file not found
#include <opencv2/opencv.hpp>
I know that there are many similar questions out there in the web, but none of the answers was actually able to fix my problem so far.
My specifications:
Qt 5.4.0 (Clang 6.0 (Apple), 64 bit)
Mac OSX 10.10.1
OpenCV 2.4.9 installed from homebrew
My .pro file looks like this:
QT += core gui multimedia multimediawidgets
greaterThan(QT_MAJOR_VERSION, 4): QT += widgets
TARGET = MainProject
TEMPLATE = app
SOURCES += main.cpp mainwindow.cpp
HEADERS += mainwindow.h
FORMS += mainwindow.ui
INCLUDEPATH += /usr/local/include/opencv2
LIBS += -L/usr/local/lib
LIBS += -lopencv_core
LIBS += -lopencv_imgproc
LIBS += -lopencv_highgui
LIBS += -lopencv_ml
LIBS += -lopencv_video
LIBS += -lopencv_features2d
LIBS += -lopencv_calib3d
LIBS += -lopencv_objdetect
LIBS += -lopencv_contrib
LIBS += -lopencv_legacy
LIBS += -lopencv_flann
I made sure the links actually link to the right locations. All the header files and all the .dylib files are there as well. I checked the type of the libraries:
$ file libopencv_core.dylib
libopencv_core.dylib: Mach-O 64-bit dynamically linked shared library x86_64
In my project settings, the qmake command is:
qmake: qmake MainProject.pro -r -spec macx-clang CONFIG+=debug CONFIG+=x86_64
Unfortunately I only have a basic understanding of these compile-things, so I am not too sure, whether it has something to do with clang? I read something about clang behaving somehow different on OSX 10.10 Yosemite, but I did not completely understand why. Info about my clang:
$ clang --version
Apple LLVM version 6.0 (clang-600.0.56) (based on LLVM 3.5svn)
Target: x86_64-apple-darwin14.0.0
Thread model: posix
I also tried to use the gcc-kit in Qt (GCC x86 64bit in /usr/bin), but this messed up a lot more, which I did not understand.
Does somebody have an idea what I am doing wrong? Any help appreciated!
Patrick
You are already including the directory opencv2 in your #include statement. You should change your include path to just INCLUDEPATH += /usr/local/include.

How to use QtCreator to statically link FLTK libraries

I am using Qt Creator (Qt 5.0.3 on Ubuntu 14) for a normal c++ project where I am using FLTK libraries. i want to link FLTK statically to my executable. How do I do that using Qt Creator( I am not using any of Qt libraries, just a normal c++ project with FLTK)
You can add suitable LIBS += -l... and INCLUDEPATH += /usr/... to your .pro

Compiling google test framework with Mingw compiler

I have a Qt project and i wanted to use google tests framework GoogleTestFramework in order to do google test. The framework compiled fine on Linux.
I have managed to compile the libraries on windows, using tips provided in the following link:
Installing Gtest without pthreads
The following advice do not let me compile the libraries, because of errors due to pthreads:
Sackoverflow compiling with MSYS
I have :
GNU Make 3.81 for make.exe
GNU Make 3.82 for mingw32-make
CMake 2.8.7
QT 4.7.4
Qt MingW gcc v 4.4.0
When i try to compile my test projet, i get an error saying:
undefined reference to '__chkstk_ms'
File not found: gtest-all.cc
Here is my qmake project code (I have semplified the code).
QT += core gui
DEPENDPATH += . headers src ../FastTrans/headers ../FastTrans/src ../FastTrans/forms C:/MinGW/msys/1.0/home/zakharan/gtest-1.6.0/include
INCLUDEPATH += . headers src ../FastTrans/headers ../FastTrans/src ../FastTrans/forms C:/MinGW/msys/1.0/home/zakharan/gtest-1.6.0/include
TARGET = tstall
#CONFIG += console
#CONFIG -= app_bundle
TEMPLATE = app
HEADERS += ../FastTrans/headers/shortcutsactionsitem.h \
../FastTrans/headers/shortcutsactionsmodel.h \
../FastTrans/headers/isavesettings.h
SOURCES += ../FastTrans/src/shortcutsactionsitem.cpp \
../FastTrans/src/shortcutsactionsmodel.cpp \
../FastTrans/src/isavesettings.cpp \
src/tstshortcutsactionsitem.cpp \
src/tstshortcutsactionmodel.cpp
INCLUDEPATH += $$PWD/
DEPENDPATH += $$PWD/
win32: LIBS += C:/MinGW/msys/1.0/home/zakharan/gtest-1.6.0/mybuid/libgtest.a
win32: LIBS += C:/MinGW/msys/1.0/home/zakharan/gtest-1.6.0/mybuid/libgtest_main.a
Google recommends the following for compiling in Windows:
### Windows Requirements ###
* Microsoft Visual C++ 7.1 or newer
### Cygwin Requirements ###
* Cygwin 1.5.25-14 or newer
I've heard of some people using MingW for compiling this. Supposedly compiling with MingW can be a little faster because there doesn't need to be a comparability layer between the OS and the application.
But, since this is just for dev testing purposes Cygwin should suffice. Just download the version that Google recommends.
See Also:
Compile Cygwin project in Eclipse
How Cygwin compares to MingW for porting Linux applications to Windows

How do I make apps smaller with qmake and macdeployqt

How do I make apps smaller with qmake and macdeployqt?
I have set QT = core gui in the projects .pro file and run qmake and macdeployqt on the resulting app.
The problem is that the program is bundling QtNetwork, QtScript, QtSvg etc. I've tried setting QT -= network script svg (and then make clean, rm -rf *.app, qmake, make).
In total the app is 32 MB.
.pro file:
TEMPLATE = app
TARGET = throw
DEPENDPATH += .
INCLUDEPATH += .
CONFIG += x86_64 release
QT = core gui
unix {
CONFIG += link_pkgconfig
PKGCONFIG += glib-2.0
}
# Input
SOURCES += main.cpp
# Headers
HEADERS += throw.h
RESOURCES += throw.qrc
ICON = throw.png
mac {
QMAKE_INFO_PLIST = Info.plist
ICON = throw.icns
}
This is a great article about (re)building Qt statically and dynamically to reduce its size considerably: Building Qt Static (and Dynamic) and Making it Small with GCC, Microsoft Visual Studio, and the Intel Compiler
While this is talking about Qt in the windows context, it does give some good insight into how one would go about compiling for minimal size.
You could strip the binary afterwards in a post-build step. The Qt libraries themselves are shared by default.

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