I have an executable build with Visual Studio 2005 using C#. dumpbin reports that it is x86 and it is claimed that it was built as a x86 target. However, when I try executing it, it somehow becomes a 64bit executable as reported by task manager, process explorer and procmon shows that it loads Framework64. And it fails eventually due to failure to load a 32bit DLL.
What could cause this behavior?
You are building it with the AnyCPU target. If you want it to be x86 even on a 64 bit system, then you must target x86.
When you target AnyCPU, the loader runs the process as a 64 bit process on a 64 bit system, but a 32 bit process on a 32 bit system.
Change the platform target from "Any" to "x86" in the project properties / build configuration list.
One can use corflags.exe to force it to run as 32-bit.
O:\>corflags
Microsoft (R) .NET Framework CorFlags Conversion Tool. Version 3.5.30729.1
Copyright (c) Microsoft Corporation. All rights reserved.
Usage: Corflags.exe Assembly [options]
If no options are specified, the flags for the given image are displayed.
Options:
/ILONLY+ /ILONLY- Sets/clears the ILONLY flag
/32BIT+ /32BIT- Sets/clears the 32BIT flag
/UpgradeCLRHeader Upgrade the CLR Header to version 2.5
/RevertCLRHeader Revert the CLR Header to version 2.0
/Force Force an assembly update even if the image is
strong name signed.
WARNING: Updating a strong name signed assembly
will require the assembly to be resigned before
it will execute properly.
/nologo Prevents corflags from displaying logo
/? or /help Display this usage message
"What could cause this behavior?"
To be techically accurate in answering this question, but not quite in the spirit you asked, what causes this behavior is the lack of the 64-bit DLL.
Why doesn't the program have a 64-bit version of it?
In a few years I doubt 32-bit systems will exist anywhere except as ARM and ARM systems will need new DLLs to be recompiled anyway.
Related
I have a .NET 5 WPF application built for AnyCPU platform.
In the project file i have:
WinExe
net5.0-windows
The output folder contains all dll and an exe but when i run the exe on a 32 bits windows i get this message:
This version of software.exe is not compatible with the version of windows
you're running. Check your computer's system information to see
whether you need a x86 (32-bit) or x64 (64-bit) version of the
program, and then contact the software publisher.
To ease deployment and run, I want to have only 1 build and 1 shortcut no matter the target system.
So my initial solution was to run the application using dotnet.exe and having the core dll as a parameter.
dotnet.exe software.dll
The WPF application start and run fine but the console with the dotnet command line is kept open during the application lifetime.
Is there a solution to get rid of the console when I start the WPF application using dotnet.exe ?
No solution without exe file at this time, so as a workaround I found a way to produce both 32bit and 64bit exe.
In the Visual Studio build configuration manager, I added x86 and x64 platforms.
Which updated the csproj with
<Platforms>AnyCPU;x86;x64</Platforms>
Then I added in csproj
<AssemblyName>MySoftware-$(Platform)</AssemblyName>
When I build the solution, it automatically append the targeted platform to the exe and dll for the platform.
MySoftware-x86.exe
MySoftware-x86.dll
MySoftware-x64.exe
MySoftware-x64.dll
Finally, I call "dotnet.exe build" twice for both x86 and x64 using a script.
To put all this together, a 32-bit machine can run anything with a PE
set to PE32, but nothing with a PE of PE32+. A 64-bit machine can run
your file in 64-bit mode as long as 32BIT is 0, but if 32BIT is 1 then
it must use WOW64.
https://illuminatedcomputing.com/posts/2010/02/sorting-out-the-confusion-32-vs-64-bit-clr-vs-native-cs-vs-cpp/
Why would you want to compile a .NET assembly specific to 32-bit or
X64, or IA? Usually because you're P/Invok'ing into a x64 specific
native dll.
The interesting things that corflags tell us are these:
CLR Header: The compiler version...2.0 is .NET 1.1, 2.5 is .NET 2.0
and 3.0 is .NET 3.5. Don't ask. ;)
PE (Portable Executable): PE32 is 32bit and PE32+ is 64-bit.
32BIT: Are we asking to force 32-bit
execution or not?
www.hanselman.com/blog/32bitness-and-64bitness-and-migrating-dasblog-on-iis7-and-aspnet-under-vista64
While I was try to use an embedded database which has both 32-and 64-bit versions like SQLite and SQL Server CE in "C# - ANY CPU"
[ Both provide XCOPY deployment for their 32 and 64 bit versions.
Check the following links: -sql server ce private installation- -XCOPY deployment with sqlite- ]
I noticed that when we check "Prefer 32 bit", XCOPY deployment not work,In that case procoess is not 64 bit but try to load ddl from x64 folder and crashes.
If we uncheck "Prefer 32 bit" it works as 64 bit and find also right dlls.
Even if I make my project x86 then it also works and find right ddls under x86.
Why does "prefer 32 bit" compile option have this behaviour? Is it a bug?
I can confirm Hippias Minor's problem - caused me some headache too. SQLite consists of a managed library that chooses which native DLL to load at run-time (either SQLite.Interop.DLL from x64 or x86 directory). This way it does not need to embed the native library (and is thus more portable - same "xcopy deployment" can work on different architectures). This is also the way SQLite is usually installed from NuGet.
The difference between "x86" and "Any CPU w/ prefer 32-bit" (beside being able to run on ARM) is that the first will set the environment variable PROCESSOR_ARCHITECTURE to "x86" while the second will set it to "AMD64"! The issue is described here: PROCESSOR_ARCHITECTURE returns AMD64 in some 32-bit processes
Therefore SQLite (which is using that as a heuristic) will try to load the 64-bit interop DLL and miserarbly fail since it is infact being run as a 32-bit process.
A workaround might be to check Environment.Is64BitProcess and when that is false manually change the environment variable to "x86".
The primary purpose of the 'Prefer 32 bit' is better processor support with the 'CPU Any' setting.
From What AnyCPU Really Means As Of .NET 4.5 and Visual Studio 11
The difference, then, between “Any CPU 32-bit preferred” and “x86” is only this: a .NET application compiled to x86 will fail to run on an ARM Windows system, but an “Any CPU 32-bit preferred” application will run successfully.
On a x64 processor setting this option is essentially the same as using the x86 compile option.
if (!Environment.Is64BitProcess
&& Environment.GetEnvironmentVariable("PROCESSOR_ARCHITECTURE")
.Equals("AMD64", StringComparison.InvariantCultureIgnoreCase))
{
// Workaround the "Any CPU" w/ "Prefer 32-bit" option from .NET 4.5+
Environment.SetEnvironmentVariable("PROCESSOR_ARCHITECTURE", "x86");
}
before any SQLite code seems to make the thing work.
I have a solution where the executable's target platform was initially set to x86, many other projects were set to AnyCPU, and included 3 projects in .Net 3.5 (everything else .Net 4.0). I presume this is why the installer wrote to the HKEY_LOCAL_MACHINE\SOFTWARE registry key.
Recently, I fixed some issues and now all projects are .Net 4.0. Additionally, I set the executable target platform to AnyCPU. I found the application was now installed in HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node.
[sidebar - we have p/invokes - DllImport attributes - that did not
specify a CallingConvention. When this was modified both in
managed and unmanaged code to specifiy Cdecl and __cdecl, we were able to
upgrade dependent projects to .Net 4.0 without receiving a PInvokeStackImbalance exception.]
We develop currently with VS2010 on Windows 7 (64-bit) machines.
My question is: Did the installer write to \SOFTWARE\ initially because some of the projects were .Net 3.5?
Also, if this application is intended to be installed on WindowsXP (32-bit is expected to be supported) machines, is the registry key problematic? Better yet, what should I look for in build options that ensures compatibility on WinXp 32-bit systems?
Only a 64-bit installer will avoid Wow6432Node on a 64-bit operating system. In a Setup project, that's set by the TargetPlatform property of the installer, it defaults to "x86". Change it to "x64" if you changed the C# EXE project's Target platform to AnyCPU. This will also ensure that your program is installed to c:\program files and not c:\program files (x86).
You will thus need to maintain two installers. Bit of a headache, you can avoid it by setting the C# EXE project's Target platform to x86 so both the installer and your program access the key in Wow6432Node.
The pinvoke problem is normally the other way around, 64-bit code has only one calling convention and there's no difference between cdecl and stdcall.
Our Teamcity agent is running on a 32bits OS for now and this was not an issue up until now (we now have an x64 applications to build in there).
I heard its possible to compile x64 applications on a 32bit OS but I've never did it. What would be the step required to have Teamcity build a specific project in x64 - Ideally using MSBuild?
When I set my project's MSBuild property "Run Platform" to x64 my agent give me the following warning: "Unmet requirements: DotNetFramework4.0_x64 exists"
As a side note: we will eventually move the agent to a 64bits OS but I would like a short term solution.
I think the Run Platform for MSBuild in TeamCity is for what version of MSBuild to use, it's looking for MSBuild.exe in the C:\Windows\Microsoft.NET\Framework64\v4.0.30319 folder, when you're on a 32-bit version of Windows, and that framework isn't installed. However, the 32-bit version of MSBuild can invoke the C# Compiler that can still produce x64 assemblies, even on your 32-bit machine.
What you want to do is do a Run Platform for x86, but pass /property:Platform=x64 as one of your commands. If you don't have a x64 Configuration, you may considering trying to pass it /property:Platform="Any CPU". However, Any CPU would only be guaranteed to work if all the assemblies you reference in your project are set the Any CPU as well. Alternative, you can create a custom configuration where all your assemblies are specified x64, and pass that via command line to MSBuild.
Keep in mind if any of your projects are C++, you will need to make sure you have the x64 compilers installed, as I don't think they're installed by default.
To complete some testing I need to load the 64 bit version of an assembly even though I am running a 32 bit version of Windows. Is this possible?
I'm not sure why you would want to do this, but I suppose you could. If you don't do anything to tell it otherwise, the CLR will load the version of the assembly that is specific to the CPU you are using. That's usually what you want. But I have had an occasion where I needed to load the neutral IL version of an assembly. I used the Load method to specify the version. I haven't tried it (and others here suggest it won't work for an executable assembly), but I suppose you can do the same to specify you want to load the 64 bit version. (You'll have to specify if you want the AMD64 or IA64 version.)
From CLR Via C# (Jeff Richter):
"If your assembly files contain only type-safe managed code,
you are writing code that should work on both 32-bit and 64-bit versions of Windows. No
source code changes are required for your code to run on either version of Windows.
In fact,
the resulting EXE/DLL file produced by the compiler will run on 32-bit Windows as well as
the x64 and IA64 versions of 64-bit Windows! In other words, the one file will run on any
machine that has a version of the .NET Framework installed on it."
" The C# compiler offers a /platform command-line switch. This switch allows you to specify
whether the resulting assembly can run on x86 machines running 32-bit Windows versions
only, x64 machines running 64-bit Windows only, or Intel Itanium machines running 64-bit
Windows only. If you don't specify a platform, the default is anycpu, which indicates that the
resulting assembly can run on any version of Windows.
32 bit Windows can not run 64 bit executables without a VM/emutalor
32 bit Windows can compile for execution on 64 bit Windows
No, you cannot run assemblies that are compiled for 64-bit on a system running the 32-bit version of Windows.