If you have an answer for this, or further information, I'd welcome it. I'm following advice from here, to offer some unsolicited help by posting this question then an answer I've already found for it.
I have a bare-metal ARM board for which I'm building a cross-toolchain, from sources for GNU binutils, gcc and gdb, and for SourceWare's Newlib. I got those four working and cross-built a DoNothing.c into an ELF file - but I couldn't disassemble it with this:
$ arm-none-eabi-objdump -S DoNothing.elf
The error was:
$ arm-none-eabi-objdump: error while loading shared libraries: libdebuginfod.so.1: cannot open shared object file: No such file or directory
I'll follow up with a solution.
The error was correct - my system didn't have libdebuginfod.so.1 installed - but I have another cross-binutils, installed from binary for a different target, and its objdump -S works fine on the same host. Why would one build of objdump complain about missing that shared library, when clearly not all builds of objdump need it?
First I tried rebuilding cross binutils, specifying --without-debuginfod as a configure option. No change, which seems odd: surely that should build tools that not only don't use debuginfod but which don't depend on it in any way. (If someone can answer that, or point out what I've misunderstood, it may help people.)
Next I figured debuginfod was inescapable (for my cross-tools built from source at least), so I'd install it to get rid of the error. It's a component of the elfutils package, but installing the latest elfutils available for my Ubuntu 20.04 system didn't bring libdebuginfod.so.1 with it.
I found a later one, for Arch Linux, whose package contents suggested it would - but its package format doesn't match Ubuntu's and installing it was going to involve a lot of work. Instead I opted to build it from the Arch Linux source package. However, running ./configure on that gave a couple of infuriatingly similar errors:
configure: checking libdebuginfod dependencies, --disable-libdebuginfod or --enable-libdebuginfo=dummy to skip
...
configure: error: dependencies not found, use --disable-libdebuginfod to disable or --enable-libdebuginfod=dummy to build a (bootstrap) dummy library.
No combination of those suggestions would allow configure for elfutils-0.182 to run to completion.
The problem of course was my own lack of understanding. The solution came from the Linux From Scratch project: what worked was to issue configure with both of the suggested options, like this:
$ ./configure --prefix=/usr \
--disable-debuginfod \
--enable-libdebuginfod=dummy \
--libdir=/lib
That gave a clean configure; make worked first time, as did make check and then sudo make install which of course installed libdebuginfod.so.1 as required. I then had an arm-none-eabi-objdump which disassembles cross-compiled ELF files without complaining.
I ran up into this glitch today, I am cross compiling many libraries for my linux system, and all except this zlib-1.2.8 works well.
My configure command is:
CFLAGS=-I/home/user/openwrt/openwrt/staging_dir/target-powerpc_8540_uClibc-0.9.33.2/include/
LDFLAGS=-L/home/user/openwrt/openwrt/staging_dir/target-powerpc_8540_uClibc-0.9.33.2/lib/
./configure --build=x86_64-unknown-linux-gnu --host=powerpc-openwrt-linux-uclibcspe
--prefix=/home/user/openwrt/openwrt/staging_dir/target-powerpc_8540_uClibc-0.9.33.2
The --build=x86_64-unknown-linux-gnu worked for all libraries, except this one.
THe error:
unknown option: --build=x86_64-unknown-linux-gnu
./configuer aborting
What is wrong? Please suggest.
It's because the configure script is not the usual one, but written especially for zlib, so the usual assumptions don't apply.
What you need for the --build=x86_64-unknown-linux-gnu is --arches="-arch x86_64"
I don't think that you can cross-compile with the resulting Makefile without some tweaks (to CFLAGS probably).
I mean, those C or C++ projects that you build from source on Linux and UNIX systems, usually by issuing those commands:
./configure
make
sudo make install
And they also have files like ./configure, ./configure.ac, ./configure.in at the top directory.
I've heard them variously called autotools projects, or autoconf projects, or automake projects, but I'm not sure which name is the correct one. Is there even a consensus on what they should be called?
Autoconf and automake are collectively called the GNU autotools (and libtool may be included in that category as well), so autotools is the most general name.
Note that not all programs that have a configure script to generate a makefile are necessarily using the autotools, or not all of them.
According to GNU it's officially called the GNU Build System, which is where you find it on Wikipedia. But most people (er, almost everyone?) calls it "the GNU autotools" or "autotools". As stated by #larsmans and others in his answer, none of these tools are required. To quote the last paragraph of the link:
The Autotools are tools that will create a GNU Build System for your package. Autoconf mostly focuses on configure and Automake on Makefiles. It is entirely possible to create a GNU Build System without the help of these tools....
The first page of the autoconf info page refers to the packages as "autoconfiscated".
I'm attempting to compile a relatively simple Fortran executable so that it can be passed around to other Windows users that don't have Cygwin (or something of the sort) installed, however, I'm unable to get the executable to operate as a standalone. I've tried gfortran -static file.f and gfortran -static-libgfortran file.f, however other users always encounter this error:
The program can’t start because cygwin1.dll is missing from your computer. Try reinstalling the program to fix this problem.
From what I've read online (e.g. here), the -static option should be sufficient. I have verified that running the executable from my machine (DOS prompt) does work.
I have gcc (gfortran) version 4.7.3. I should also point out this is my first attempt at compiling portable Fortran.
Update
After realizing that this isn't a gfortran-specific issue (thanks to replies here), searches led me to related posts here and here
This is partially explained in the Cygwin FAQ. The solution is to install the mingw64-i686-gcc-fortran package with its dependencies, and cross-compile your code with i686-w64-mingw32-gfortran -static.
Just package the cygwin1.dll along with your binary file (both in the same folder) then it will run just fine.
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.