I have a 32-bit object file o.obj and want to use it in a project that uses a 64-bit library l.lib.
To make the .lib happy, the Visual Studio configuration needs to be set to x64. However, the linker then throws an error of error LNK1112: module machine type 'X86' conflicts with target machine type 'x64'.
I went through Visual Studio's linker options, but nothing jumped out. Is there a way to resolve this error?
I was under the impression that any 32-bit code is also compatible with 64-bit systems, modulo libraries.
x86 executables (that is, object code compiled for 32-bit x86 processors) can be executed on x64 machines running 64-bit operating systems, through a special compatibility mode supported jointly by the processor and the operating system. This is feasible because the x86 instruction set is a subset of the x64 instruction set.
However, many elements of the ABI differ between x86 and x64 code, notably calling conventions and pointer size. The calling convention needs to match between the calling code and the called code, or things will screw up. Thus, there is no straightforward way to call 64-bit code from 32-bit code, or vice versa.
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Visual studio 2015/2017/2019/2022 all come with (somewhat hidden) compiler for 32-bit ARM processors. The 64-bit ARM Windows also comes with support for running 32-bit applications. However, after I built some C++ applications using that 32-bit compiler I find myself unable to actually run it because build rules for most software include /MD compile flag which links the exe/dll-s against the dynamic VS runtime in a few dll-s (vcruntime140.dll, etc.). My arm system is missing that runtime (at least the arm version) and I cannot find it anywhere. All the publicly available runtime downloads include only x86, x64 and arm64.
What am I missing? Building modern software with the runtime linked-in is inefficient and often will not work correctly due to sharing runtime-specific structures across library boundaries. But the dynamic runtimes are nowhere to be found. Is 32-bit ARM considered deprecated or only useful for simple single-binary embedded applications? Or is there something about arm platform which makes linked-in runtimes work for applications spanning multiple binaries? Are the arm runtime installers available in some dark corner?
Is it possible to set up the compiler in such a way so it compiles the executable/DLL for both x86 and x64? I mean, one file suitable for both platforms.
I only know of a way to choose the platforms separately, but I want both.
Is it possible?
x86 executable is fully supported on x64 host. E.g. any EXE you compile in 32-bit mode will run without any problems on 32-bit and 64-bit host. If you don't know why you need 64-bit executable, you probably don't, so 32-bit executable alone will suffice.
However, with DLLs it is a different matter. The DLL's architecture (32-bit or 64-bit) must match the executable where the DLL is going to be used. E.g. if you're writing an Explorer extension for x64 Windows, explorer.exe is going to be 64-bit, so your DLL must also be 64-bit, otherwise it cannot be loaded.
There is no way to combine two different architectures into one DLL or EXE on Windows. So you're going to need two DLLs if you need to support both 32-bit and 64-bit hosts.
I have a problem related to this question. Two players:
C# application
Mixed assembly used by 1)
The application has to support anything from Windows XP (32bit) to Windows 7 (32 & 64bit). The assembly is complicated in different ways. It contains managed C++/CLI code and some native C++ classes dancing with native DirectX. It also is linked to a few 32bit native dll's w/o source access (containing C++ classes with import libraries).
Things are working well in 32bit environments (XP and 7 tested) including the 32bit subsystem on Windows 7. Havoc happens, as soon as "Any CPU" is used on 64bit systems in order to build the complete solution. The 32bit assembly is unusable than - but seemingly only in debug mode ("cannot load, wrong format" etc.). It seems to work in release. A 64bit assembly build is prevented by the implicit dependencies to the mentioned 32bit third-party dll's.
Is there any way to provide a real native 64bit application able to use the assembly?
Requirement for the assembly isn't that strict. It could be both - 32 or 64bit - but as said above, should be be usable from the application one way or the other.
You are running into a rock hard limitation in the 64-bit version of Windows, a 64-bit process cannot execute any 32-bit machine code in-process. You certainly have a dependency on machine code when you use C++/CLI and work with DirectX. Although it doesn't sound like you could not execute in 64-bit mode, both C++/CLI and DirectX can be compiled/are available in 64-bit.
This then boils down to a build and deployment issue. You have to build the C++/CLI project(s) in 64-bit mode and deploy only 64-bit components on a 64-bit operating system. The main EXE must be built to AnyCPU. Similarly, on a 32-bit operating system you must build and deploy only the 32-bit compiled version. You solve the build issue by adding the x64 configuration to the solution so you build the 32-bit and 64-bit version separately. You solve the deployment issue by creating two installers.
Since you have to support a 32-bit operating system anyway, the simple solution is to change the Target platform setting on your EXE project to x86. Now everything always runs in 32-bit mode and you don't have to bother with the build and deployment headaches. The only thing you miss out on is the larger virtual memory address space that's available in the 64-bit version.
Forget about the C++/CLI project for a minute.
You have third-party 32-bit DLLs. These CANNOT load in a 64-bit process. So your main application will have to be 32-bit. This restriction has nothing to do with the C++/CLI middleman.
The only way you can make use of these DLLs from a 64-bit application is to load them in a separate (32-bit) process and marshal data back and forth.
i have a 64-bit machine with 64-bit OS...
how can i compile programs with Visual Studio 2010 so that they work on 32-bit system
if i install 32-bit OS on my 64-bit machine than i thinks it won't be a problem
If you are talking about .NET applications simply verify that you are targeting x86 in the properties of your project (this is the default setting) or Any CPU:
This is a nice property of just-in-time compiled code. It runs just as well on a 32-bit machine (using the x86 jitter) as a 64-bit machine (x64 jitter). The only time you get in trouble is when you need to use legacy unmanaged code that's only available as 32-bit machine code. Not uncommon with old dbase providers (like Jet) and COM servers. You've got the right kind of machine to detect these problems early.
Emphasizing: you don't have a problem if the target machine is 32-bit, only if it is a 64-bit machine.
Is there any way to compile an EXE file, so that it will run natively in both x86 and x64? Something like: compile both codebases and pack them into a single executable.
I know .NET code could run in "any cpu" mode, but it is not what I want.
A 32-bit executable will run natively on 32-bit and x64 Windows machines. The only way you're going to get x64 execution within a 32-bit PE file is by using an undocumented gate, which I highly doubt anyone uses in practice because it's highly version dependent (and undocumented).
Then again you make it so the 32-bit binary will execute a 64-bit version of the binary and exit if it detects a 64-bit CPU...
You could take the Process Explorer approach. In your 32-bit binary embed the 64-bit binary as a resource. If the 32-bit binary is launched on a 64-bit machine, extract the 64-bit binary and launch that.