Good Morning.
I am compiling Clang, following the instructions here Getting Started: Building and Running Clang
I am on linux and the compilation goes smoothly. But I think I am missing out something...
I want to compile ONLY clang, not all the related libraries. The option -DLLVM_ENABLE_PROJECTS=clang seems doing what I want (check LLVM_ENABLE_PROJECTS here)
If I use the instructions written there, I can compile, but I think I am compiling too much....a build directory of 70GB seems too much to me...
I tried to download the official debian source and compile the debian package (same source code! just using the "debian way" to create a package from official debian source), just to compare...The compilation goes smoothly, is very fast, and the build directory is much much smaller...as I expected...
I noticed in the first link I provided the phrase "This builds both LLVM and Clang for debug mode."...
So, anyone knows if my problem is due to the fact that I am compiling a "debug mode" version? if so, how could I compile the default version? and is there a way to compile ONLY clang without LLVM?
Yes, debug mode binaries are typically much larger than release mode binaries.
Cmake normally uses CMAKE_BUILD_TYPE to determine he build type. It can be set from the command line with -DCMAKE_BUILD_TYPE="Release" o -DCMAKE_BUILD_TYPE="Debug" (sometimes there are other build types as well).
I've installed Swift lang for Linux (Ubuntu) and it works fine. For example:
print("Hello World")
To run it:
./swift hi.swift
My question is, is it possible to generate a native executable code for it? How?
Listing the executable files in the Swift directory, it has swiftc. It generates a native executable binary by command:
swiftc hi.swift -o hi
./hi
In addition to swiftc, one can also generate native executables by using the Swift build system, which is described at
https://swift.org/getting-started/#using-the-build-system
Using the build system, one can easily build native executables from multiple source files, while swiftc is a convenient way to build an executable from a single source file.
Please note that you also need to install Clang if you want to create native executables with Swift. Clang is not needed to run the swift command interactively or to run a .swift file. Interestingly, installing GCC (including g++) and creating symlink clang++ to g++ does allow swiftrc to build an executable. This also enables swift build to work. At least it is true for very simple programs. However, this is not a "blessed" way. Apple docs at swift.org say that Clang is needed.
I want to cross compile the Qt libraries (and eventually my application) for a Windows x86_64 target using a Linux x86_64 host machine. I feel like I am close, but I may have a fundamental misunderstanding of some parts of this process.
I began by installing all the mingw packages on my Fedora machine and then modifying the win32-g++ qmake.conf file to fit my environment. However, I seem to be getting stuck with some seemingly obvious configure options for Qt: -platform and -xplatform. Qt documentation says that -platform should be the host machine architecture (where you are compiling) and -xplatform should be the target platform for which you wish to deploy. In my case, I set -platform linux-g++-64 and -xplatform linux-win32-g++ where linux-win32-g++ is my modified win32-g++ configuration.
My problem is that, after executing configure with these options, I see that it invokes my system's compiler instead of the cross compiler (x86_64-w64-mingw32-gcc). If I omit the -xplatform option and set -platform to my target spec (linux-win32-g++), it invokes the cross compiler but then errors when it finds some Unix related functions aren't defined.
Here is some output from my latest attempt: http://pastebin.com/QCpKSNev.
Questions:
When cross-compiling something like Qt for Windows from a Linux host, should the native compiler ever be invoked? That is, during a cross compilation process, shouldn't we use only the cross compiler? I don't see why Qt's configure script tries to invoke my system's native compiler when I specify the -xplatform option.
If I'm using a mingw cross-compiler, when will I have to deal with a specs file? Spec files for GCC are still sort of a mystery to me, so I am wondering if some background here will help me.
In general, beyond specifying a cross compiler in my qmake.conf, what else might I need to consider?
Just use M cross environment (MXE). It takes the pain out of the whole process:
Get it:
$ git clone https://github.com/mxe/mxe.git
Install build dependencies
Build Qt for Windows, its dependencies, and the cross-build tools;
this will take about an hour on a fast machine with decent internet access;
the download is about 500MB:
$ cd mxe && make qt
Go to the directory of your app and add the cross-build tools to the PATH environment variable:
$ export PATH=<mxe root>/usr/bin:$PATH
Run the Qt Makefile generator tool then build:
$ <mxe root>/usr/i686-pc-mingw32/qt/bin/qmake && make
You should find the binary in the ./release directory:
$ wine release/foo.exe
Some notes:
Use the master branch of the MXE repository; it appears to get a lot more love from the development team.
The output is a 32-bit static binary, which will work well on 64-bit Windows.
(This is an update of #Tshepang's answer, as MXE has evolved since his answer)
Building Qt
Rather than using make qt to build Qt, you can use MXE_TARGETS to control your target machine and toolchain (32- or 64-bit). MXE started using .static and .shared as a part of the target name to show which type of lib you want to build.
# The following is the same as `make qt`, see explanation on default settings after the code block.
make qt MXE_TARGETS=i686-w64-mingw32.static # MinGW-w64, 32-bit, static libs
# Other targets you can use:
make qt MXE_TARGETS=x86_64-w64-mingw32.static # MinGW-w64, 64-bit, static libs
make qt MXE_TARGETS=i686-w64-mingw32.shared # MinGW-w64, 32-bit, shared libs
# You can even specify two targets, and they are built in one run:
# (And that's why it is MXE_TARGET**S**, not MXE_TARGET ;)
# MinGW-w64, both 32- and 64-bit, static libs
make qt MXE_TARGETS='i686-w64-mingw32.static x86_64-w64-mingw32.static'
In #Tshepang's original answer, he did not specify an MXE_TARGETS, and the default is used. At the time he wrote his answer, the default was i686-pc-mingw32, now it's i686-w64-mingw32.static. If you explicitly set MXE_TARGETS to i686-w64-mingw32, omitting .static, a warning is printed because this syntax is now deprecated. If you try to set the target to i686-pc-mingw32, it will show an error as MXE has removed support for MinGW.org (i.e. i686-pc-mingw32).
Running qmake
As we changed the MXE_TARGETS, the <mxe root>/usr/i686-pc-mingw32/qt/bin/qmake command will no longer work. Now, what you need to do is:
<mxe root>/usr/<TARGET>/qt/bin/qmake
If you didn't specify MXE_TARGETS, do this:
<mxe root>/usr/i686-w64-mingw32.static/qt/bin/qmake
Update: The new default is now i686-w64-mingw32.static
Another way to cross-compile software for Windows on Linux is the MinGW-w64 toolchain on Archlinux. It is easy to use and maintain, and it provides recent versions of the compiler and many libraries. I personally find it easier than MXE and it seems to adopt newer versions of libraries faster.
First, you will need an arch-based machine (virtual machine or docker container will suffice). It does not have to be Arch Linux, derivatives will do as well. I used Manjaro Linux.
Most of the MinGW-w64 packages are not available at the official Arch repositories, but there is plenty in AUR. The default package manager for Arch (Pacman) does not support installation directly from AUR, so you will need to install and use an AUR wrapper like yay or yaourt. Then installing MinGW-w64 version of Qt5 and Boost libraries is as easy as:
yay -Sy mingw-w64-qt5-base mingw-w64-boost
#yaourt -Sy mingw-w64-qt5-base mingw-w64-qt5-boost #if you use yaourt
This will also install the MinGW-w64 toolchain (mingw-w64-gcc) and other dependencies.
Cross-compiling a Qt project for windows (x64) is then as simple as:
x86_64-w64-mingw32-qmake-qt5
make
To deploy your program you will need to copy corresponding dlls from /usr/x86_64-w64-mingw32/bin/. For example, you will typically need to copy /usr/x86_64-w64-mingw32/lib/qt/plugins/platforms/qwindows.dll to program.exe_dir/platforms/qwindows.dll.
To get a 32bit version you simply need to use i686-w64-mingw32-qmake-qt5 instead. Cmake-based projects work just as easily with x86_64-w64-mingw32-cmake.
This approach worked extremely well for me, was the easiest to set-up, maintain, and extend.
It also goes well with continuous integration services. There are docker images available too.
For example, let's say I want to build QNapi subtitle downloader GUI. I could do it in two steps:
Start the docker container:
sudo docker run -it burningdaylight/mingw-arch:qt /bin/bash
Clone and compile QNapi
git clone --recursive 'https://github.com/QNapi/qnapi.git'
cd qnapi/
x86_64-w64-mingw32-qmake-qt5
make
That's it! In many cases, it will be that easy. Adding your own libraries to the package repository (AUR) is also straightforward. You would need to write a PKBUILD file, which is as intuitive as it can get, see mingw-w64-rapidjson, for example.
Ok I think I've got it figured out.
Based in part on https://github.com/mxe/mxe/blob/master/src/qt.mk and https://www.videolan.org/developers/vlc/contrib/src/qt4/rules.mak
It appears that "initially" when you run configure (with -xtarget, etc.), it configures then runs your "hosts" gcc to build the local binary file ./bin/qmake
./configure -xplatform win32-g++ -device-option CROSS_COMPILE=$cross_prefix_here -nomake examples ...
then you run normal "make" and it builds it for mingw
make
make install
so
yes
only if you need to use something other than msvcrt.dll (its default). Though I have never used anything else so I don't know for certain.
https://stackoverflow.com/a/18792925/32453 lists some configure params.
In order to compile Qt, one must run it's configure script, specifying the host platform with -platform (e.g. -platform linux-g++-64 if you're building on a 64-bit linux with the g++ compiler) and the target platform with -xplatform (e.g. -xplatform win32-g++ if you're cross compiling to windows).
I've also added this flag:
-device-option CROSS_COMPILE=/usr/bin/x86_64-w64-mingw32-
which specifies the prefix of the toolchain I'm using, which will get prepended to 'gcc' or 'g++' in all the makefiles that are building binaries for windows.
Finally, you might get problems while building icd, which apparently is something that is used to add ActiveX support to Qt. You can avoid that by passing the flag -skip qtactiveqt to the configure script. I've got this one out of this bug report: https://bugreports.qt.io/browse/QTBUG-38223
Here's the whole configure command I've used:
cd qt_source_directory
mkdir my_build
cd my_build
../configure \
-release \
-opensource \
-no-compile-examples \
-platform linux-g++-64 \
-xplatform win32-g++ \
-device-option CROSS_COMPILE=/usr/bin/x86_64-w64-mingw32- \
-skip qtactiveqt \
-v
As for yout questions:
1 - Yes. The native compiler will be called in order to build some tools that are needed in the build process. Maybe things like qconfig or qmake, but I'm not entirely sure which tools, exactly.
2 - Sorry. I have no idea what specs files are in the context of compilers =/ . But as far as I know, you wouldn't have to deal with that.
3 - You can specify the cross compiler prefix in the configure command line instead of doing it in the qmake.conf file, as mentioned above. And there's also that problem with idc, whose workaround I've mentioned as well.
I'm trying to implement an open source library that is built using the GNU compiler. (namely, this: https://github.com/mjwybrow/adaptagrams )
I've tried opening and building that source code using VSC++ 6, but it results in over a thousand errors due to the strict nature of the VS compiler I guess. And rather then go through every error and try fix it myself, I was wondering if it's possible to just include the .lib if it is built with the GNU compiler?
EDIT:
Included in the source code linked above is an autogen.sh file.
mkdir -p m4
autoreconf --install --verbose
automake -a --add-missing
./configure
make
Running that with Cygwin results in a few .a library files to be created, which are unusable in VS. Is it ok to just rename these to .lib files?
I've found some stuff online about how to use GCC and create a DLL, but my problem is that I don't know enough about the GNU compiler or makefiles, or the source code in general to be able to change it right now.
Does anybody have any clues on what exactly I'd need to change to get it right? Or even better, has anyone created a DLL using this source code already that would be able to pass it on to me, or let me know what I have to do?
Or could anyone point me towards a similar library that would be compatible with visual studio?
No; you can however build the .dll file with gcc and use the .dll from msvc (with either a hand-crafted include file or a properly formatted one from the beginning, with platform specific import/export macros on top).
I have Cygwin and MinGW (TDM) installed. To build certain projects from source, you have to run a ./configure script, which requires a bash shell and certain unix utilities. For this, the MinGW project distributes MSYS, which is basically an old, stripped-down version Cygwin. I already have Cygwin installed, so I'd rather just use that. What packages would I need to install for Cygwin and how would I need to invoke ./configure so that it knows that I'm trying to use MinGW to build native Windows binaries?
You are aware that Cygwin comes with a MinGW-compiler and library built in? By using the -mno-cygwin switch you turn the Cygwin gcc into a MinGW gcc. How you'd tweek ./configure to use this is beyond me, but I suppose it would depend on the ./configure script.
What I do is usually to tweek the generated Makefiles by adding the -mno-cygwin switch to the compiler and linker flags.