I am trying to compile a 32-bit application on 64-bit Debian Stretch. I have compiled several other applications successfully this way, but one app that uses the pcap library is giving me problems. There does not seem to be a 32-bit version of this library anywhere for my platform.
Problem description
When I try to link my application, like this:
g++ (...objectfiles-and-options...) -m32 -o myapp -lpthread -lpcap
I get the error
/usr/bin/ld: cannot find -lpcap
I checked, and there is indeed no libpcap.so (or variant thereof) in /usr/lib32. However, all other libraries I am using is present there (like libpthread). I tried to create soft-links to the 64-bit pcap-libraries in there, just in case they should be multi-platform compatible, but that only resulted in "skipping incompatible /usr/lib32/libpcap.so when searching for -lpcap".
I've installed libpcap-dev, libc6-dev-i386, gcc-multilib and g++-multilib (obviously, since cross-compilation works fine for all applications that does not use libpcap). I would suspect there should be a libpcap-dev-i386 I could install, but there does not seem to be one.
Perhaps I should mention that the application compiles and links successfully as 64 bit.
Does anyone know what I am missing here?
You can compile libpcap yourself. It's probably the better solution than depending on packages.
Use configure for 32bit architecture and than give your compiler LDFLAGS pointing to your lib or install it in /usr/lib32/
Related
I'm trying to use the Canon EDSDK (latest version, v3.6 as of writing) in a simple, C++, command-line program on macOS (Sierra 10.12.6). I wish to utilize a simple Makefile environment and the usual apple compiler tools (llvm-clang) and avoid Xcode or any other heavy-weight IDE. The samples included with the SDK are all Xcode centric so I've had to roll my own here.
At present, I am able to compile a program to init the SDK and list connected cameras. As soon as I execute any EDSDK command however, I am getting a dynamic linking error:
Error loading /Library/Frameworks/EDSDK.framework/Versions/A/DppCore.bundle/Contents/PlugIns/DppCoreG.bundle/Contents/MacOS/DppCoreG: dlopen(/Library/Frameworks/EDSDK.framework/Versions/A/DppCore.bundle/Contents/PlugIns/DppCoreG.bundle/Contents/MacOS/DppCoreG, 262): no suitable image found
Did find: ... snip ... mach-o, but wrong architecture
The same error lists twice (both for DppCoreG). Upon examination, DppCoreG is compiled for 64bit architecture:
file /Library/Frameworks/..snip../DppCoreG
/Library/Frameworks/..snip../DppCoreG: Mach-O 64-bit bundle x86_64
However, there are other critical parts of the EDSDK that are compiled for 32bit architecture only:
file /...snip.../DPP.framework/DPP
/...snip.../DPP.framework/DPP: Mach-O dynamically linked shared library i386
How do I resolve this? The path of least resistance so far is to compile to i386 architecture explicitly (and the documentation explicitly states EDSDK is not 64-bit compatible). All is well except this one dynamic linking error (and in fact everything I've tried so far, which is just listing connected cameras, seems to work okay) but it is something I'm sure I can't continue to ignore or allow to persist in a production version of this project.
Here's a minimal example to cause the DYLD error:
#include <EDSDK.h>
#include <EDSDKTypes.h>
#include <EDSDKErrors.h>
int main(int argc, char** argv) {
EdsInitializeSDK();
EdsTerminateSDK();
return 0;
}
And probably more informative is the command to compile:
c++ -D __MACOS__ -g -arch i386 -I./deps/mac/include -framework DPP -framework EDSDK -o min min.cpp
I have the headers in the local include directory shown in the command and the frameworks installed under /Library/Frameworks.
Note that the c++ command is Apple LLVM version 8.1.0 (clang-802.0.42)
I've concluded that this is just an error on the part of those that deliver the EDSDK for mac. They should be compiling this particular bundle as a universal binary, not a 64bit binary. You can work around the problem by simply removing the offending bundle. It appears to just be a plugin and removing it does not seem to immediately affect the SDK. Assuming you have installed the EDSDK framework in /Library/Frameworks then just do this:
sudo rm -rf /Library/Frameworks/EDSDK.framework/Versions/Current/DppCore.bundle/Contents/PlugIns/DppCoreG.bundle
Enter your password when prompted (this assumes you are an admin account) and it will delete the offending plugin.
I have to believe that there may be consequences for removing this plugin at some point and if anyone knows more about this particular bundle/plugin and can explain what removing it will do I'd appreciate the additional insight.
In addition to #OllieBrown answer, I found in Xcode building for MacOS I had an additional item to remove to stop the link warnings.
link warning- EDSDK.framework/Versions/Current/DPPLibCom.bundle/Contents/MacOS/DPPLibCom: mach-o, but wrong architecture
removing EDSDK.framework/Versions/Current/DppLibCom.bundle stopped the warning.
Since the 3.x version there is a split between intergrated versions of DPP RAW capabilities. The original DPP works in x86 mode only and allows inspection and conversion of CR2 files on cams up until a certain models. See the API doc for the list. For recent camera models which rely on the new 64bit DPP engine (v4+?, dppcoreg) you would need x86_64 bit build so it dynamically links to use the latest features. Quite some (Raw) features are dropped, and gradually make their way back in in beta state.
I've downloaded MinGW with mingw-get-inst, and now I've noticed that it cannot compile for x64.
So is there any 32-bit binary version of the MinGW compiler that can both compile for 32-bit Windows and also for 64-bit Windows?
I don't want a 64-bit version that can generate 32-bit code, since I want the compiler to also run on 32-bit Windows, and I'm only looking for precompiled binaries here, not source files, since I've spent countless hours compiling GCC and failing, and I've given up for a while. :(
AFAIK mingw targets either 32 bit windows or 64 bit windows, but not both, so you would need two installs. And the latter is still considered beta.
For you what you want is either mingw-w64-bin_i686-mingw or mingw-w64-bin_i686-cygwin if you want to compile for windows 64. For win32, just use what you get with mingw-get-inst.
See http://sourceforge.net/apps/trac/mingw-w64/wiki/download%20filename%20structure for an explanation of file names.
I realize this is an old question. However it's linked to the many times the question has been repeated.
I have found, after lots of research that, by now, years later, both compilers are commonly installed by default when installing mingw from your repository (i.e. synaptic).
You can check and verify by running Linux's locate command:
$ locate -r "mingw32.*[cg]++$"
On my Ubuntu (13.10) install I have by default the following compilers to choose from... found by issuing the locate command.
/usr/bin/amd64-mingw32msvc-c++
/usr/bin/amd64-mingw32msvc-g++
/usr/bin/i586-mingw32msvc-c++
/usr/bin/i586-mingw32msvc-g++
/usr/bin/i686-w64-mingw32-c++
/usr/bin/i686-w64-mingw32-g++
/usr/bin/x86_64-w64-mingw32-c++
/usr/bin/x86_64-w64-mingw32-g++
Finally, the least you'd have to do on many systems is run:
$ sudo apt-get install gcc-mingw32
I hope the many links to this page can spare a lot of programmers some search time.
for you situation, you can download multilib (include lib32 and lib64) version for Mingw64:
Multilib Toolchains(Targetting Win32 and Win64)
By default it is compiled for 64bit.You can add -m32 flag to compile for 32bit program.
But sadly,no gdb provided,you ought to add it manually.
Because according to mingw-64's todo list, gcc multilib version is done,but gdb
multilib version is still in progress,you could use it maybe in the future.
Support of multilib build in configure and in gcc. Parts are already present in gcc's 4.5 version by using target triplet -w64-mingw32.
gdb -- Native support is present, but some features like multi-arch support (debugging 32-bit and 64-bit by one gdb) are still missing features.
mingw-64-todo-list
I'm currently programming an extension to a program, which only supports
i386 (and I am running amd64 Ubuntu 11.10). Whenever I compile my extension source
I need to use the -m32 flag to force 32 bit architecture (otherwise the program will not be able to load my extension). Sooner or later it is inevitable to avoid boost
thanks to its huge and stable library, which leads to my problem.
I want to use the boost filesystem, which uses OS specific function calls, which in turn leads to the requirement of a library file instead of only a header implementation. The problem is; I can't/don't know how to setup the boost filesystem (i386 version) on my amd64 machine. If I download a prebuilt (.deb) package for i386 and install it using -force-architecture it still fails complaining about dependencies.
So basically; how do I setup boost with 32bit (i386) architecture on my (amd64) system?
It seems as if I did it right all along but I was too dumb to realize how to properly link libraries with the GCC linker, coming from a Windows environment. You can easily compile boost libraries by using the -m32 flag and by setting up bjam properly. See the first answer in this question for details: How do I force a 32 bit build of boost with gcc?
I am trying to compile a 32-bit version (MinGW) of a program I wrote using zlib. Until now, I've never has to compile for 32-bit so the version of zlib I compiled from source (libz.a) is 64-bit. I tried to rerun the makefile in the zlib-1.2.5 directory but it only compiles a 64bit version of libz.a.
I can't seem to find an option to build 32-bit.
Does anyone know how to do this?
Thanks!
Jeffrey Kevin Pry
Checking the configure file, you can see some env.
On 64bit debian, following command line will build the 32bit version of libz
CFLAGS=-m32 ./configure
It turns out I had to get the 32bit version of MinGW and compile it with that. I was using MinGW64.
Using CFLAGS=-32 won't do it for me, configure script still shouts out telling me to use win32/Makefile.gcc instead all the time.
The recent version of zlib is 1.2.11, so it should be minimal gap of difference up until today. Without any context on system, the following might be useful for other users facing this similar problem these days.
I cross compile on Linux (Ubuntu 18.04), and target 32-bit version of zlib to be produced. What I did is as follows.
./configure (this is just to let us have required file to building process, we will be using different Makefile though)
Modify win32/Makefile.gcc for its PREFIX=i686-w64-mingw32- (for 64-bit you change it to PREFIX=x86_64-w64-mingw32-.
make -fwin32/Makefile.gcc
Install to your desire location via make install -fwin32/Makefile.gcc SHARED_MODE=1 INCLUDE_PATH=/tmp/zlib-win32/include LIBRARY_PATH=/tmp/zlib-win32/lib BINARY_PATH=/tmp/zlib-win32/bin. Notice that you need to specify INCLUDE_PATH, LIBRARY_PATH, and BINARY_PATH. BINARY_PATH will contains result .dll file.
I am a java developer. I have some C++ code to make some system realted calls. This code is compiled on Intel 32-bit platform using GCC (I have make files) and it works fine on regular Intel based 32-bit linux machine. Now I need to run this on a linux OS running on Marvell ARM processor. When I load the shared objects in java I get the following error.
cannot open shared object file: No such file or directory (Possible cause: can't load IA 32-bit .so on a ARM-bit platform)
Please tell me how to resolve this issue. I looked at the GCC options and I found one option to specify the architecture (-march=armv5) and I can't compile with that option.
Thanks in advance.
You need more than just a switch, you need a cross-compiler. You can make your own, but probably the easiest way is :
Find the development tools for your board. It probably comes with a development kit that includes a cross-compilation toolchain
If you don't have these, you can try to install a precompiled cross-compilation like the ones provided freely by CodeSourcery
Then you have to make the location of your toolchain (look for something like arm-none-linux-gnueabi-gcc) available in your path.
Cross compiling simple project is then easy, just override the CC variable in your Makefile :
CROSS = arm-none-linux-gnueabi-
CC = $(CROSS)gcc
LD = $(CROSS)ld
Try using the -mcpu=armv5 switch for gcc.
Here is what's written on http://elinux.org/RPi_Software#ARM:
-Ofast -mfpu=vfp -mfloat-abi=hard -march=armv6zk -mtune=arm1176jzf-s