I am a self taught software engineer. I am building a desktop application that needs to work on 64 bit windows 7 system.
I am planning to integrate a third party library called FCL C++. In FCL's official documentation page it is stated that it can be built from source on unix or win32 systems.
My question is, if I build a win32 dll of FCl in Windows, would I be able to use it in my win64 application? If not then is there any other ways to go about this?
I am currently developing the software in windows 10, using CMAKE and Qt. Would developing in Linux would be better in this case?
Win32 is a legacy name of the the API set and platform. It applies to both 32 bit and 64 bit Windows. When you build the DLL, you can choose the output to be a it for 32-bit or 64-bit binary in Visual Studio.
While a 64-bit Windows OS can run a 32-bit program (EXE), a 64-bit process EXE can't load a 32-bit DLL. Just build a Win32 DLL for either 32-bit or 64-bit depending on what type of EXE you are building for.
If you are unsure, just build everything (DLL, LIB, EXE) for 32-bit since that runs everywhere.
Related
I have fallen in love with the capabilities of Rheolef, a C++ library for Finite Element Analysis that is available for Linux only. I am developing an application in Windows and was wondering if I can build Rheolef for Windows and use it in my application.
I read a few posts about Cygwin but my understanding is that it only mimics the Linux environment in a Windows settings. Also, I found a technique that can compile a single source code for Windows.
Is there any tool or method that could make the entire Rheolef library for Windows from Linux?
I haven't been able to find any information on this issue:
I have a C++ Windows Phone 8.1 library project, I would like to convert it into a portable library without having to recreate the project and set all parameters.
I guess it should be possible to do it by editing the vcxproj file, but I don't know how to modify it to make it work.
I meet several issues:
What is the equivalent of Portable Library (C#) for C++?
How to change an existing Windows Phone 8.1 C++ project into this equivalent?
Thanks :)
In general, Windows Phone 8.x doesn't support sharing of binaries with Windows desktop because the import libraries are different between the two (eg, desktop apps link against kernel32.dll but that DLL doesn't exist on Windows Phone). You could share between Windows Phone 8.0 and 8.1 though (provided you only used features available in 8.0).
In theory you might be able to make a static lib that was shared if it didn't depend on any Windows APIs, but it's not really supported. You could try creating a new Static Library project and diffing it against your current project to see what settings have changed.
This changes in Windows 10, where shared binaries are fully supported (obviously you still need ARM vs x86 vs x64 builds depending on CPU architecture).
According to Maximize code reuse between Windows Phone 8 and Windows 8 C++ is not supported as PCL language as this is a .net framework technology.
Note that Portable Class Libraries are a .NET Framework concept and don’t support C++
I also looked into Visual Studio to confirm that and couldn't find a template.
How do I know if the program I am writing in C++ will run properly in a 32-bit OS or not?
(without manually testing in one)
I am using Visual Studio and compiling in a 64-bit machine. Will that stop the program from working in other machines?
And what about the processor and Windows version? Will the binary be compatible with most Windows versions and processors, if the program just does a few simple things such as web requests and calculations, with a simple user interface?
My program doesn't have to be 64-bit. I would just like to create one binary that runs in most computers, like those I download every day on the Internet. How could I do that?
If you are building your code specifically for 64-bit Windows, you can't expect the binary to work on 32-bit Windows. That will require a separate build.
An executable compiled and linked for 64-bit will typically also require 64-bit libraries.
Use tools like the Dependency Walker to find out, if a given executable is refering to 32- or 64-bit libraries.
In Visual Studio, the "target platform" decides which CPU architecture you are targeting. It is perfectly feasible to create 64-bit executables on a 32-bit system, but you can't actually run them on such a machine.
You can do what's called cross-compiling i.e compiling on one machine for another. How to compile a 32-bit binary on a 64-bit linux machine with gcc/cmake This is what you're after if I read you correctly. There should be a Windows equivalent.
I have Credential manager implemented in VC++ which captures credentials during login process. It works well in XP/Vista/Windows 7 32 bit env. But is not working in 64 bit.
Any idea ?
Thanks in advance for any help
If you want your DLL to be loaded by a 64-bit process, your DLL has to be compiled for 64 bits.
If you want your DLL to be loaded by a 32-bit process, your DLL has to be compiled for 32 bits. This is true on both 64-bit Windows systems and 32-bit Windows systems.
John gave you a useful link, even though John's wording is wrong. An application (exe) which is built for 32 bits will run in 64 bit Windows, but it can only load 32-bit DLLs.
Did you build for a 64-bit platform in Visual Studio?
A Visual C++ application which is build for a 32-bit environment won't work directly in a 64 bit environment. And although applications will work using the WOW64 compatibility layer, DLLs must be 64-bit if they are to be loaded by a 64-bit operating system.
Since that is indeed the case here, you need to build your project for a 64-bit platform (Visual Studio 2005 and later have a 64-bit compiler).
See the link http://msdn.microsoft.com/en-us/library/ms185328.aspx for more details.
Here is my problem:
I have developed an application which can be run on various platforms, including Windows and Unix. This app runs well on pure Win32 box (WinXP) or a pure Win64 (Win2K3 x64 edition) and other unix platforms.
It only fails when running on a 64 bit Win2K3 in 32 bit mode. This app invokes a third party dll at the runtime. And the third party dlls are not formally installed, but just copied to a location in the same env. I'm also sure I'm having the right version of these 3rd party dlls (I mean 32 bit version for 32 bit mode). Even I manually set the "path" in this testing box, it still doesn't work. The app is compiled and built in 32 bit mode in this Win2K3 box.
I run dependency walker and see the same error. Cannot find that 3rd party dll.
Can anyone shed some lights on this? How do I make that 3rd party dll path visible to my app or the system?
I would suggest you to do the following:
ensure that you are using 32-bit
version of the problematic DLL with 32-bit app
use filemon to see what paths your
application tries while loading that
DLL
check whether it works if you place
that DLL into one of those paths
use dependency walker with that DLL
itself - it might have its own unresolved
dependencies
WOW64 redirects all calls by 32 bit applications to the System32 folder to the SysWOW64 folder. Is the third party DLL in the system32 folder? Because the system32 folder, contrary to what you'd expect, contains ONLY 64bit DLLs on Windows x64.