Static linking in Windows [duplicate] - c++

I am trying to deploy(release to public) a simple qt application I made recently, but got stuck at static linking qt libs.
I followed the guide on qt docs to re-build qt and my app statically. But the release build still require qtgui / qtcore dll for no apparent reasons, I wonder if anyone has seen this kind of problems before ? Or even better, has successfully resolved it ?
http://doc.qtsoftware.com/4.5/deployment-windows.html

I wrote a guide to static linking
and
How to build Qt static with multiple compilers and keep it small
(because it can get pretty big, especially for simple programs).
You may also want to check out the BitRock installer, which is free for open source projects.
In short, it turns out to be a little more complex if you are using anything Qt thinks of as a plugin, such as support for most image types (JPEG, GIF) or databases.
For example, if you want to include support for Oracle DBMS and GIF images for your icons, you add the following to your .PRO file:
QTPLUGIN += qsqloci qgif
CONFIG += static
You will then need to:
#include <QtPlugin>
in your project, and import any plugins used. You need to change these settings back order to get it to compile with dynamic linking again (like when debugging or adding features), though this can be easily automated. There are also considerations when building the Qt libraries for use with static linking, though the Qt instructions will at least get you started.

With Qt 5.5, things are quite easy. There's the configure script you have to run before building Qt. There are following orthogonal settings that you pass to configure:
Do you want a static Qt library?
-static option should be passed to configure
Do you want the build of Qt, and of your application, to use a static C++ runtime?
-static-runtime option should be passed to configure
Do you want XP targeting?
-target xp option should be passed to configure
Additionally, follow the instructions from this blog post.
Qt Creator didn't support XP targeting automagically at least until v.3.5.0 since it doesn't set up the environment for the build tools properly. You have to modify the build environment manually per the blog post.

Also, be aware that your static build will still link to the visual studio runtimes dynamically!
See this faq (internet archive link, in case the link goes away) :
Why does a statically built Qt use the dynamic Visual Studio runtime libraries ? Do I need to deploy those with my application ?
Qt is built using the -MD(d) switch, which links against the dynamic C/C++ runtime libraries. This is necessary as we have experienced memory problems when using anything but the -MD(d) flag, and in general, it is recommended to use. You should not alter this flag yourself for your application, because it conflicts with how the Qt library is built if you change the flag to -MT. You should not change it for Qt either, since it is likely to cause problems.
Qt is still built statically when using the -static option though, meaning you do not need to distribute the Qt dlls when deploying your application. You will have to distribute the C runtimes though (if they don't already exist on the target machine), see our deployment documentation http://doc.qt.io/qt-5/windows-deployment.html#application-dependencies.

msys2 has a pre-built static Qt5 package
e.g. pacman -S mingw-w64-qt5-static
Currently, to also get all dependencies of Qt statically linked, with CMake, you need to add:
list(PREPEND CMAKE_FIND_LIBRARY_SUFFIXES .a .lib)
before calling find_package(Qt5…
CMAKE_AUTOSTATICPLUGINS was replaced by a new upstream implementation and is not needed anymore.

I just compiled an application statically (Debug)
with QT Plugins(5.9),
with VS (2015) (Win).
a) Add to your code.
#include <QtPlugin>
Q_IMPORT_PLUGIN (QWindowsIntegrationPlugin);
b) Add the following to the link paths
\5.9.0_x86_static_install\lib
\5.9.0_x86_static_install\bin
\5.9.0_x86_static_install\plugins
\5.9.0_x86_static_install\plugins\platforms
\5.9.0_x86_static_install\plugins\imageformats
c) Add the list of QT static libraries and internal VS libraries to your link list.
version.lib
imm32.lib
shlwapi.lib
rpcrt4.lib
Ws2_32.lib
Mpr.lib
Netapi32.lib
Rpcrt4.lib
Iphlpapi.lib
winmm.lib
gdi32.lib
advapi32.lib
msimg32.lib
UxTheme.lib
translatord.lib
preprocessord.lib
d3d9.lib
dxguid.lib
libEGLd.lib
libGLESv2d.lib
iphlpapi.lib
psapi.lib
ws2_32.lib
Dwmapi.lib
Qt5CoreD.lib
Qt5Guid.lib
Qt5Xmld.lib
Qt5Widgetsd.lib
Qt5Networkd.lib
Qt5Winextrasd.lib
Qt5PlatformCompositorSupportd.lib
qicod.lib
qtmaind.lib
qtlibpngd.lib
qtharfbuzzd.lib
qtpcre2d.lib
qwindowsd.lib
Qt5FontDatabaseSupportd.lib
Qt5ThemeSupportd.lib
Qt5EventDispatcherSupportd.lib
Qt5AccessibilitySupportd.lib
qtfreetyped.lib
Kevin Higgins

I recommend you to use linuxdeployqt this tool. It can help solve most of the dependency problems. And I use it to package my qt application successfully.

This answer applies to using MSYS2 with mingw-w64 as the compiler, in Windows, and qmake. The QT version is 5.15.0.
Installing the package qt5-static gives you a build of QT that produces executables who don't rely on any QT DLLs. (Example commandline - pacman -Ss mingw64/mingw-w64-x86_64-qt5-static).
However a new problem is introduced here: it does not pass the -static flag to gcc. Meaning that although the executable does not depend on QT DLLs, it does depend on libgcc-s, libwinpthread.dll etc.
Normally, this problem would be fixed by using CONFIG += static which causes qmake to pass -static to gcc. However, and as noted in the other answers, for a qt-static build that config option is ignored!
To solve this I had to manually specify the gcc flags for static linking in the qmake file, i.e. :
QMAKE_CXXFLAGS += -static
QMAKE_LFLAGS_WINDOWS += -static
Which results in a (large) binary with no external dependencies other than Windows system DLLs.
(In case it matters: my use case was building a COM in-process server DLL that should have no external dependencies; I was also using TEMPLATE=lib and CONFIG += dll).

Related

How do I setup a Codeblocks project on Windows 10 to compile and link a static SFML project?

My advance appologies for being hopeless at Windows development. I am by no means a Windows developer and my understanding of how to write, compile and link C++ code on a Windows system is limited to say the least.
I am having difficulty trying to compile and link a SFML project on a Windows 10 system with the CodeBlocks IDE.
I am trying to link this project with static linking, not dynamic linking. Again I have virtually no idea how the two different methods work in detail, I just know that if I ship a static linked binary to another Windows 10 user it is much more likely to "just work" on their system.
List of things I did:
Downloaded the latest version of CodeBlocks with MINGW integration.
Installed, default options
Downloaded the latest version of SFML (32bit MINGW version)
Extracted the zip file (SFML) to my home directory
Created a new codeblocks project (console application) and followed the instructions to set the compiler and linker options
https://www.sfml-dev.org/tutorials/2.5/start-cb.php
It works fine for dynamic linking, but requires me to copy the .dll files to the same dir as the produced executable file (produced from compilation of my C++ code).
I tried to change to static linking, changing the names of the linker libs with the -s or -s-d suffix, and adding the define SMFL_STATIC option to global (release and debug) options. I also added the opengl32, freetype, winmm and gdi32 link libs, before their respective sfml link libs.
When trying to compile I get the following linker errors
cannot find -lfreetype
cannot find -lsfml-graphics-s-d
cannot find -lsfml-window-s-d
cannot find -lsfml-system-s-d
in Release mode, similar errors are produced.
What am I doing wrong?
My hunch would be that you either have the wrong compiler (see below) or you haven't defined the library directory as mentioned in the linked tutorial.
There are four common things to consider when using SFML (and essentially any other C++ library) on Windows.
Compiler versions have to fully match
Make sure to not mix x86 and x64
Settings need to be specified for the correct configuration
When linking libraries statically, you also need to link the dependencies
Compiler versions have to fully match
Since C++ doesn't have a standardized ABI, the generated libraries will never be reusable between compilers. Yes, sometimes "it works", but it can break at any point and there's no guarantee.
We strongly recommend to either use the compilers linked on the SFML Download page or build SFML from source with your current compiler.
If you got the latest stable Code::Blocks version with MinGW as stated, you should also be able to get a snapshot build of SFML, which should be using the same compiler.
Note: One exception to this rule is Visual Studio, where VS 2017 binaries are compatible with VS 2019 (and maybe VS 2022?).
Make sure to not mix x86 and x64
When you download a 32-bits (x86) version of SFML, you also need a 32-bits version of your compiler. When you download a 64-bits (x64) version of SFML, you also need a 64-bits version of your compiler.
Make sure you double check your compiler configuration that you've selected the correct bit-ness.
Note: For Visual Studio you need to select the correct compiler architecture in the IDE, usually positioned right next to the run button.
Settings need to be specified for the correct configuration
Project configurations are usually spread across the matrix built from the types:
Debug / Release / All
x86 / x64 (for VS)
Make sure when you add the settings for library paths and include paths that it's not just set for debug or release and ends up missing in either or the other configuration.
Also make sure you're not setting up debug libraries (with the -d suffix) in release mode or release libraries (without any suffix) in debug mode.
When linking libraries statically, you also need to link the dependencies
The SFML static libraries don't contain any symbols of any of its dependencies, that means, in your final application you have to link static SFML and all its dependencies.
As a short summary you can think of static libraries like an archive of object files. These object files will directly be linking into your application, like you link your own source file object files. As such, the SFML static libraries only contain object files of SFML itself and not of other libraries as well.
Troubleshooting
If nothing seems to help, then you should enable verbose compiler & linker output, that we you see exactly which commands are invoked and one can quickly spot the missing statements.

Adding static library link line to my Qt project file makes no difference

I've read a lot of "duplicate" posts on the subject of statically linking your Qt project on windows to statically built Qt core libs. However, I was left very confused when I compared it to what I am seeing. What I gathered from all the posts is if you already have the statically built Qt libs (which I seem to have here C:\Qt\5.4\mingw491_32\lib) all you need to do is to include a line like so
LIBS += -LC:/Qt/5.4/mingw491_32/lib -lQt5Core -lQtGui
in your .pro file without having to specify -static anywhere. However, this line seems to do exactly ZERO. When I comment it out my project builds exactly the same way without it. The exe is the same size and when I try to run it from command prompt a runtime error appears in a dialog box saying it can't find Qt5Core.dll. Its clearly still linking dynamically. What am I doing wrong? Here is the whole .pro file.
#QT +=
greaterThan(QT_MAJOR_VERSION, 4): QT += widgets
TARGET = testproj
TEMPLATE = app
SOURCES += main.cpp mainwindow.cpp
HEADERS += mainwindow.h
FORMS += mainwindow.ui
QMAKE_CXXFLAGS +=-std=c++11
#LIBS += -LC:/Qt/5.4/mingw491_32/lib -lQt5Core
I clearly have major holes in my understanding of how Qt linking works on windows. Any help on this topic is highly appreciated.
Qt does not distribute static builds.
It seems you only have a dynamic build and got confused by the .lib/.a files. On Windows, there are 3 types of library:
Dynamic libraries (.dll)
Static libraries (.a or .lib depending on the toolchain)
Import libraries (.a or .lib depending on the toolchain)
Import libraries are only used with dynamic libraries. The import libraries are used by the linker when generating the exe, while the dynamic libraries are used at run time.
So if you have Qt5Core.lib or Qt5Core.a does not mean you have a static build of Qt.
To build your own static version of Qt, I suggest your read Building a static Qt for Windows using MinGW on Qt's wiki.
The major hint is: no matter how Qt is built, you shouldn't need to change anything in the project that uses Qt. Qmake and the configuration files in a given Qt install govern how the applications that use Qt are linked against Qt.
Another hint: a given Qt installation can be either configured for static or dynamic linking, not both. Thus any sort of configuration on the project end is superfluous: a given Qt install already "knows" how to link Qt correctly.
Any given .pro file should work whether Qt is linked statically or dynamically. You should not have any static-linking-specific entries. Remove the LIBS line from the project.
If your executable is dynamically linked, the only reason is that you're using a dynamically linked build of Qt. You should make a static build yourself first, and then use it with your project, and your executable will be statically linked against Qt. It's that simple.
Qt Creator doesn't care about these details either. All it does is invoke qmake and then the make tool. But each qmake is specific to a particular installation of Qt, and that qmake is configured to access that installation's configuration files, and those files contain the data needed to select the proper linking etc. So all of the information is specific to a particular kit one is using, and specifically to the Qt "version" that kit is using (really, a Qt installation because there can be multiple installs of the same version, configured differently).

Build static linked app with Qt5 on Windows [duplicate]

I am trying to deploy(release to public) a simple qt application I made recently, but got stuck at static linking qt libs.
I followed the guide on qt docs to re-build qt and my app statically. But the release build still require qtgui / qtcore dll for no apparent reasons, I wonder if anyone has seen this kind of problems before ? Or even better, has successfully resolved it ?
http://doc.qtsoftware.com/4.5/deployment-windows.html
I wrote a guide to static linking
and
How to build Qt static with multiple compilers and keep it small
(because it can get pretty big, especially for simple programs).
You may also want to check out the BitRock installer, which is free for open source projects.
In short, it turns out to be a little more complex if you are using anything Qt thinks of as a plugin, such as support for most image types (JPEG, GIF) or databases.
For example, if you want to include support for Oracle DBMS and GIF images for your icons, you add the following to your .PRO file:
QTPLUGIN += qsqloci qgif
CONFIG += static
You will then need to:
#include <QtPlugin>
in your project, and import any plugins used. You need to change these settings back order to get it to compile with dynamic linking again (like when debugging or adding features), though this can be easily automated. There are also considerations when building the Qt libraries for use with static linking, though the Qt instructions will at least get you started.
With Qt 5.5, things are quite easy. There's the configure script you have to run before building Qt. There are following orthogonal settings that you pass to configure:
Do you want a static Qt library?
-static option should be passed to configure
Do you want the build of Qt, and of your application, to use a static C++ runtime?
-static-runtime option should be passed to configure
Do you want XP targeting?
-target xp option should be passed to configure
Additionally, follow the instructions from this blog post.
Qt Creator didn't support XP targeting automagically at least until v.3.5.0 since it doesn't set up the environment for the build tools properly. You have to modify the build environment manually per the blog post.
Also, be aware that your static build will still link to the visual studio runtimes dynamically!
See this faq (internet archive link, in case the link goes away) :
Why does a statically built Qt use the dynamic Visual Studio runtime libraries ? Do I need to deploy those with my application ?
Qt is built using the -MD(d) switch, which links against the dynamic C/C++ runtime libraries. This is necessary as we have experienced memory problems when using anything but the -MD(d) flag, and in general, it is recommended to use. You should not alter this flag yourself for your application, because it conflicts with how the Qt library is built if you change the flag to -MT. You should not change it for Qt either, since it is likely to cause problems.
Qt is still built statically when using the -static option though, meaning you do not need to distribute the Qt dlls when deploying your application. You will have to distribute the C runtimes though (if they don't already exist on the target machine), see our deployment documentation http://doc.qt.io/qt-5/windows-deployment.html#application-dependencies.
msys2 has a pre-built static Qt5 package
e.g. pacman -S mingw-w64-qt5-static
Currently, to also get all dependencies of Qt statically linked, with CMake, you need to add:
list(PREPEND CMAKE_FIND_LIBRARY_SUFFIXES .a .lib)
before calling find_package(Qt5…
CMAKE_AUTOSTATICPLUGINS was replaced by a new upstream implementation and is not needed anymore.
I just compiled an application statically (Debug)
with QT Plugins(5.9),
with VS (2015) (Win).
a) Add to your code.
#include <QtPlugin>
Q_IMPORT_PLUGIN (QWindowsIntegrationPlugin);
b) Add the following to the link paths
\5.9.0_x86_static_install\lib
\5.9.0_x86_static_install\bin
\5.9.0_x86_static_install\plugins
\5.9.0_x86_static_install\plugins\platforms
\5.9.0_x86_static_install\plugins\imageformats
c) Add the list of QT static libraries and internal VS libraries to your link list.
version.lib
imm32.lib
shlwapi.lib
rpcrt4.lib
Ws2_32.lib
Mpr.lib
Netapi32.lib
Rpcrt4.lib
Iphlpapi.lib
winmm.lib
gdi32.lib
advapi32.lib
msimg32.lib
UxTheme.lib
translatord.lib
preprocessord.lib
d3d9.lib
dxguid.lib
libEGLd.lib
libGLESv2d.lib
iphlpapi.lib
psapi.lib
ws2_32.lib
Dwmapi.lib
Qt5CoreD.lib
Qt5Guid.lib
Qt5Xmld.lib
Qt5Widgetsd.lib
Qt5Networkd.lib
Qt5Winextrasd.lib
Qt5PlatformCompositorSupportd.lib
qicod.lib
qtmaind.lib
qtlibpngd.lib
qtharfbuzzd.lib
qtpcre2d.lib
qwindowsd.lib
Qt5FontDatabaseSupportd.lib
Qt5ThemeSupportd.lib
Qt5EventDispatcherSupportd.lib
Qt5AccessibilitySupportd.lib
qtfreetyped.lib
Kevin Higgins
I recommend you to use linuxdeployqt this tool. It can help solve most of the dependency problems. And I use it to package my qt application successfully.
This answer applies to using MSYS2 with mingw-w64 as the compiler, in Windows, and qmake. The QT version is 5.15.0.
Installing the package qt5-static gives you a build of QT that produces executables who don't rely on any QT DLLs. (Example commandline - pacman -Ss mingw64/mingw-w64-x86_64-qt5-static).
However a new problem is introduced here: it does not pass the -static flag to gcc. Meaning that although the executable does not depend on QT DLLs, it does depend on libgcc-s, libwinpthread.dll etc.
Normally, this problem would be fixed by using CONFIG += static which causes qmake to pass -static to gcc. However, and as noted in the other answers, for a qt-static build that config option is ignored!
To solve this I had to manually specify the gcc flags for static linking in the qmake file, i.e. :
QMAKE_CXXFLAGS += -static
QMAKE_LFLAGS_WINDOWS += -static
Which results in a (large) binary with no external dependencies other than Windows system DLLs.
(In case it matters: my use case was building a COM in-process server DLL that should have no external dependencies; I was also using TEMPLATE=lib and CONFIG += dll).

How to use static library in Qt 5.2?

I downloaded qt recently.
I want to create an standalone exe,
but I don't know what can I do.
In Qt5.2, the folder "(Qt)\lib" is exists, but i can't use it in Qt Creator.
So, should I build from source,
or configure Qt Creator and use the "lib***.a"?
Any ideas?
Environment: MinGW-32 4.8.1(TDM) / Windows 7
You seem to have tried CONFIG+=static, but that is not meant for this use case. That is used when you would like to use build your library to be static after the end of the build.
This is not the case here because you already have static Qt libraries available, so what you wish instead, to link those statically against your executable.
You would need to use this in your qmake project file:
LIBS += -L/path/to/the/static/QtCore -lQtCore
You could also use, albeit this would make the build-system less portable across different platforms:
LIBS += /path/to/the/statis/QtCore/libQtCore.a

Qt 3rd Party Library Static Linking (QtSerialPort)

Turns out static linking was working, but only for Qt libraries. My 3rd party library QtSerialPort is not linking statically. After some reasearch, I've found that I either have to build this library statically or I have to link directly to a .pri file in my .pro file.
I'm not sure how to do either since it seems QtSerialPort has not been designed for static linking.
The .pri method I really don't understand and has been vaguely described in these two links:
http://qt-project.org/forums/viewthread/15223
http://www.qtcentre.org/archive/index.php/t-54505.html
Does anyone have any adivce on how to get either of these methods to work? Or possibly another method?
Also, MSVCP100.dll is not linking statically if anyone could give me any advice on that.
==================================================================================
I am trying to get Qt to statically link libraries so that I can make a standalone application. I have followed various tutorials on how to build Qt statically then building a static application but I am not having much luck. I believe I have succesfully built Qt with static linking because the application has grown in size from 79KB to 7+MB but I am still getting errors saying QtCore4.dll and QtSerialPort.dll are missing. Also, another issue I'm having when using this static configuration, which isn't too serious, is that when I close my program Windows thinks it has crashed and gives me a window saying MyProgram.exe has stopped working...
I am on a Windows machine using MSVC 2010 with Qt 4.8.5 and am using the third party library QtSerialPort.
What I've done accoring to the guides I've been reading is:
Download and extract qt-everywhere-opensource-src-4.8.5.zip
Open /mkspec/mwin32-msvc2010/qmake.conf and change the follwing lines to
CONFIG += qt warn_on release incremental flat link_prl precompile_header autogen_precompile_source copy_dir_files debug_and_release debug_and_release_target
and
QMAKE_CLFAGS_RELEASE = -O2 -MT
I then open the MSVC2010 command prompt and cd to this . I then enter the commands
configure -static -release -platform win32-msvc2010
nmake sub-src
After this is done I open my project and add
CONFIG += static
to the .pro file. In QtCreator I then go into Projects, Manage Kits then to Qt Versions and browse to the qMake I just generated. I add a new Kit with this version of qMake. I then clean all and switch to this new kit and run qmake from QtCreator. I then use msvc2010 command prompt to go to the directory where the files are generated and then
nmake release
This generates a rather large .exe but like I said, it's still depending on a couple .dll's.
For static linking of external library one have a couple options, both have their pros and cons.
I. Compile the library for static linking yourself. Link to it.
Look for possible existing configuration switches for static linking. There can be something like QTSERIALPORT_STATIC = no, etc. in the library's .pro/.pri files. Just say yes for the library to compile for static linking and go to the step 4!
In .pro/.pri file replace CONFIG += dll with CONFIG += static.
Remove export declarations from the library. Typically Qt library symbols are declared with some definition like QTSERIALPORT_EXPORT which expands to Q_DECL_EXPORT/Q_DECL_IMPORT in shared library build / its header files usage when linking. You'll need to find where this QTSERIALPORT_EXPORT is defined and replace it with empty definition:
#define QTSERIALPORT_EXPORT // in source file
or
DEFINES += QTSERIALPORT_EXPORT # in .pro/.pri file
Build the library.
Link to the library .lib/.a file, use the library header files for symbol declarations in your project.
II. Include the library source files into your project and compile them within it (no linking at all).
Include all the source files of the library into your project (add to SOURCES in qmake project file)
Determine all the stuff the library depends on (other libraries, Qt options, etc.) and include it also into your .pro file.
OR
Include the proper .pri file into your .pro if the library author provides it for in-project compilation (i.e. include(QtSerialPort.pri) or something.)
Remove export/import declarations from the library source code — as described in the item 3 of part I.
Build your project.