C++ dlls version number - dll

Is it must that all the dlls created in C++ have a version number ? I have dlls in my machine but when i right click i am not able to see the version number.
P.S : I have Win 7 installed.

It's important to understand, that the version number will be not used during loading the DLL. So it's not required information which DLL or and Program Executable (Like .EXE, .OCX, .SYS, .FON and so on) must have.
The real purpose of version is to help installation program to compare the DLL existing on the computer with the installed one. The most important version in the case is FILEVERSION part or the VERSIONINFO resource. You can read more about the API to access the information on MSDN.
The version resource is very practical also for support. If you good protocol the changes in the DLL which you redistribute to other computers or other clients then the version resource could help you for troubleshooting. By examining of the version of the DLL you can probably find out whether the problem which take place is already well-known and are fixed in the more recent version of the DLL.

It's not mandatory to have version information in a DLL. However, if you intend to release more than 1 version, it is recommended to add some versioning information for support/maintenance purposes.
Here's how you add version information to win32 binaries.
Also you can embed version information in an existing exe/dll.
EDIT: added some more information for purpose (from Oleg's link):
You can use the version information functions to determine where a file should be installed and identify conflicts with currently installed files. These functions enable you to avoid the following problems:
installing older versions of components over newer versions
changing the language in a mixed-language system without notification
installing multiple copies of a library in different directories
copying files to network directories shared by multiple users
The version information functions enable applications to query a version resource for file information and present the information in a clear format. This information includes the file's purpose, author, version number, and so on.
You can add version information to any files that can have Windows resources, such as DLLs, executable files, or .fon font files. To add the information, create a VERSIONINFO Resource and use the resource compiler to compile the resource.

Related

Wix Toolset: How to restore replaced file on uninstall

I have two products - product A and product B.
Product A contains file A.dll with version 1.0.0. Or any other type of file (.config with text 1.0.0).
Product B updates file A.dll with version 2.0.0 (or config with text 2.0.0).
After uninstallation of Product B, it removes A.dll.
If I mark A.dll in product B as "rermanent" it will not be removed.
But I need to restore A.dll version 1.0.0 after product B has been uninstalled.
As a possible workaround, I can run Product A in "restore" installation mode.
Is there any other solution?
P.S: Case example:
Product A has been released, and due to some bugs, required hot-fixes come next as a Product B (to have additional entry in Programs and Features list).
The Product B (hot-fix) replaces A.dll with newer one.
I want to support uninstallation of Product B (hot-fix) and return to state before it is installed (A.dll with version 1.0.0).
If these are separate products, why do you install one on top of the other? Is this a UAT / QA construct for temporary use? Could you install these products side-by-side (in separate folders for each product) and then just pull back whichever version you don't need anymore? Your scenario of pulling back bits and pieces of your "new" install that is mixed in with your original install does not work well with Windows Installer.
Is this a released product or are you still in development? Why not just pull back what is on the box and install a new version of your setup which cleans up everything. You could author the upgrade table to uninstall both existing products you have already deployed. For safety reasons i would change the path you install to for the new version of your setup, and I would uninstall the existing packages early in the InstallExecuteSequence.
The overall message: you are not supposed to mix different products in the same installation location. Each product is supposed to have its own installation folder, and if you have several setups installing to the same location the files should be installed with the same component guids.
See if this makes some sense to you: Change my component GUID in wix?
If you're really talking about data files (such as config files) that you want to restore when Product B is uninstalled, I think we're looking at a custom action when A is installed which backs up the data used by A. When B is uninstalled it restores the data from the backup location.
Either way, the issue seems to be the application design where A and B both apparently share some common set of data files, except that they only share when both are installed.
NOTE: this answer was written before the OP modified his question.
In my opinion this indicates an error in application design. What you are dealing with is a shared file that is required in two different versions - or so it seems? Can product A use version 2.0.0 of the dll or does it absolutely require version 1.0.0?
Short answer:
Either install the dll that you have shared now as a private dll in the main application's installation folder (for each product, in the version they require), or...
Make sure both products can use the most updated dll in the shared location (shared deployment requiring full backwards compatibility).
You can also install the two dll versions side-by-side (in the GAC for .NET assemblies, or in WinSxS for Win32 files) or somewhere else on disk where both applications can access them (they load the one they need - and leave the other version alone on uninstall). Which version loads depends on the application manifest (some find messing up the manifest to be the second coming of dll-hell - the wrong stuff is loaded).
Finally you can statically link the dll's into your main executable (my least preferred option for large corporation deployment - details below). Static linking in .NET is a little bit different from native, Win32 binaries: Static Linking of libraries created on C# .NET. I am not sure of the performance implications of static .NET linking (I only ever do Win32 static linking).
As a rule of thumb shared files must be rather stable with few updates to really be useful as shared. They are typically "libraries". I might chose to deploy private copies for a while during development until I reach a more stable state and switch to shared files (side-by-side or global, whichever fits).
If you are dealing with COM, then the technology's overall "global registration nature" makes it necessary to maintain backwards compatibility (files are always shared) or you can try "registration-less COM" -
essentially COM with the registry information embedded in manifest files and local copies of all files in the main application installation directory - everything happens in one folder in an "isolated" fashion. COM is old, but since it is used for .NET via COM Interop it will continue to be a headache for everyone for years to come.
Below is a more elaborate discussion of these options. It got a little messy - like it gets when you just write off the top of your head. I will try to clean it up as soon as I get some distance to it and can see clearer what is wrong with it.
If product A can use version 2.0.0, then you have a basic shared file between applications, and the normal way to install it would be a merge module included by both setups. You should have backwards compatibility so that product A can use any version of the file, including version 2.0.0. Product B should also be able to use any version of the shared dll, and you should be able to deploy an upgrade to the shared dll that both products can handle. A genuinely shared file. During product installation higher versions of the file should always be installed, and all products using the file should be able to handle the new version (backwards compatibility). Great if you have security hot-fixes that you want to deploy to many products quickly and reliably without rebuilding all products individually. This is obviously what shared files are for.
If product A can't use version 2.0.0 of the dll, then you likely have a side-by-side installation scenario (like the global assembly cache - different versions of the same assembly installed at the same time and applications load the one they need). You should install both versions of the dll in different places (with different file names), and your product A and product B should load the one they need. Or you should install to the GAC - this is what the GAC is for (.NET assemblies only). There is also a side-by-side concept for normal Win32 files (Windows side-by-side assemblies). You must never mess around in the WinSxS folder directly (the Windows assembly folder for Win32 dlls), see this excellent explanation from Advanced Istaller - just like for the GAC files are registered for installation to WinSxS). When you uninstall either product A or product B the dll needed by the other application is left untouched (there could also be other products using them). Side by side files can also be shared between products, but they won't be uninstalled if there are other products registered that need them on your product's uninstall and there are several different versions of the file to choose from so you crucially do not need to maintain backwards compatibility between the different "branches" (backwards compatibility must still be maintained for each branch - i.e version 1.0.1 must be compatible with 1.0.0 but not 2.0.0).
The most obvious option might be to include your now shared DLL in your product's main application folder - making it a "private file" that is never attempted shared between other applications / products. This works best for Win32 dll's or .NET assemblies (no registry impact or global registration - unless the .NET assembly is registered for COM Interop). COM files are registered system-wide in the registry and should be installed to a shared location with genuine backwards compatibility or delivered in a brand new versions side-by-side with the old one (with new interfaces - rarely done). .NET assemblies can be installed side-by-side in the GAC if you need side-by-side deployment, or you can deployed them into the main application's directory as "private copies" of the assembly.
So for files used by many products you have shared files, shared side by side files, installing private copies of the dll in the application's main installation folder and a final option is static linking - compiling the dll's into your product's main executable. Just mentioning this since some people prefer this option. It does not allow deployment of updates to the shared files (or your private copy of the file for that matter), but any updates to the libraries require a full recompile and redeployment of both products (or however many products we are talking about) - a lot of work. People may find this option appealing at first, but tire of it quickly. It all depends how many updates will be made to your application and the shared components (now statically linked). We repeat that too often: it all depends, but it does.
It all depends :-) on how you have designed your application and how much you want to deploy files that are shared between products and that can be updated on their own. The great benefit of deploying a private copy of your dll next to your main application exe (instead of static linking) is that you can deliver an updated dll without recompiling your whole application exe (which could be huge). You minimize the risk of new bugs being introduce in other parts of the application, and you deliver "a little hotfix" of your product, and not a full blown recompile with all the QA work that entails. You have a targeted dll-fix and a new setup to UAT / QA (if you do it well, that setup can be delivered as a patch as well).
What I like about (genuinely) shared files is that I can deliver them with a separate setup that can be updated on its own, without affecting your main product's setup at all (when I say genuinely I mean files that are used by dozens of applications, not just a couple). This decouples things nicely and all that is needed is some QA / UAT of the main application after the shared files have been "hot-fixed". There is no full recompile of your main product AND a new setup for it to QA / UAT. If you deliver many large products this is very important. You could face some excruciatingly important security hot-fixes for your shared files that are used by dozens of other applications. I see this a lot in large corporations, for example banks - you could spend weeks or months updating the same problem in dozens of products otherwise. A nightmare for everyone.
I should add, and this is a personal opinion, that I don't really like merge modules that much. It is an OK concept, but for all intents and purposes it amounts to static linking for your setup. Not quite, but almost - all files are included at compile time is what I mean. The good news, however, is that an upgraded version of the merge module can be included in another setup that will upgrade the same files as long as you have higher version files in your upgraded merge module (in your new setup). So it is not quite "static linking", but it sort of feels like it.
My personal preference: do use shared files if they really help keeping lots of products updated and hot-fixed. In most cases these shared files are very stable with few(er) updates, and because of this work well as shared (you will thank yourself at some point - when something really hits security-wise). Deploy the shared files via their own setup and set that setup as a prerequisite for your own product's setup. This is what has proved most flexible and feature complete for me - especially in large corporations (for in-house software). You can chain it all together with a bootstrapper like WiX's Burn (in corporations you would use a deployment system like SCCM instead to set up dependencies), and you can deliver updates separately for your shared files and your application files. If your application is simple and your shared files are not too stable, just deploy a private copy of the dll(s) in your main installation directory (unless it is a COM file). I would avoid too much static linking (I only prefer static linking for minimal dependency scenarios - like when you make a custom action dll for your WiX setup and you want it to run on any machines without dependencies).
Good deployment depends on good development decisions. It is all cohesion and coupling. There are only rules of thumbs and no way that is right for everyone. It will be a lot of work no matter what you do, but try to avoid small changes affecting too many applications requiring a full development / deployment release cycle for all of them - it is the overall goal of shared files.

JNA try to Access native DLL and get module not found error, Dependencies are missing

I have Visual Studio 2010 installed and have a project I got from someone else which I can build successfully without any errors. I get a Wrapper.dll,
which I would like to access using JNA.
I am using Win7 64-bit.
But I get the error: java.lang.UnsatisfiedLinkError: Unable to load library 'Wrapper': The specified module could not be found.
Wrapper.dll of course is in the correct folder and it is a 32-bit dll and my Java program also uses a JRE with 32-bit, so this is not the cause of the error.
I used DependencyWalker to check whether *.dlls are missing:
MSVCP80.DLL
MSVCR80.DLL
GPSVC.DLL
IESHIMS.DLL
And yes there are some missing.
Can I conclude that the error is related with that these DLLs are missing?
But why does Visual Studio compile correctly then and does not throw an error?
How to solve this in order to access these functions in Wrapper.dll?
I also read that downloading dll's might not be the right thing to do!
(I know that Wrapper.dll relies on another dll or sourcecode which was built in Visual Studio 2005, if that is of interest.)
EDIT:
I found out, that Wrapper.dll relies on three other dlls which probably were built on MSVS2005. These require the above mentioned DLL's (checked with dependencywalker) and I guess therefore Wrapper.dll also links them.
So what do I actually do to get rid of these old dll's?
Would I need to build the other three DLLs with VS2010 or
is this a problem which always will appear, meaning, that you need to copy paste old DLLs in order to use the precompiled Libraries which are dependent on those.
Is there a way, that the program would run on any other system as well without copy pasting these DLL's?
All required DLLs must be available to the system for loading. If you define jna.library.path, that is where JNA will look for the initially loaded DLL, as well as any dependent DLLs. In addition, java.library.path (which is essentially PATH) will be searched for dependent DLLs.
MSVS often uses paths in addition to PATH when building, debugging, and running code within that environment.
Solutions:
a) remove dependencies you don't really need; this may include telling MSVS to build your DLL differently
b) include non-system DLLs next to your custom DLL (or include their location in PATH/java.library.path)
EDIT
a) you can include the offending DLLs in the same directory as yours. this is fairly low impact on the target system, but if they are DLLs that are expected to be on any system, you shouldn't have to do so. It's preferable to adjust java.library.path so that all system DLLs are accessible.
b) you can recompile your dependent DLLs and be more careful about backward compatibility and explicit linkage. Depending on features used by the DLLs, though, you may not be able to remove the dependencies.
MSVC[RP]80.DLL are C and C++ runtimes, respectively; you may or may not be able to link against a previous version.
IESHIMS.DLL is part of IE and should be on the system, but likely in a path inaccessible to your program.
GPSVC.DLL has to do with group security policy, so it should be available on the system (modulo whenever the DLL was introduced).

Packaging DLLs with a LabVIEW Toolkit

I have a set of utility LabVIEW VIs that make calls to a custom DLL written in C++. I'd like to package the VIs into a LabVIEW toolkit and deploy it via an installer, but am unsure about the standard practices involved in doing this where a custom DLL is involved. I've looked at VIPM for packaging the VIs, but so far I haven't found a way to generate a package and include the appropriate DLL dependencies. What is the correct way to go about generating an installer for a LabVIEW Toolkit and installing the DLL dependency for said toolkit in the correct location (where ever that may be)?
The DLLs immediately known to the system - i.e., the ones entered in the CLFN node - are added automatically.
DLLs which are used indirectly and DLLs which are determined programmatically cannot be auto-included and must be added manually to the Source files section of the respective Build rule.

Using version 4053 of CRT (/MD) instead of leatest greatest (5592) in DLL (VS2005 SP1)

I hope you can help me with this.
I want to build a dll (statically linking other, non-third-party libraries) using version 4053 of the CRT (/MD) instead of the latest (5592) in Visual Studion 2005 SP1.
I'm wondering if using the following method is enough to accomplish this. By using this method in all dependent projects of the solution, to my understanding, the dll's embedded manifest is altered to state the CRT (and MFC, ATL) version requested. Is this assumption correct?
Is simply making sure the dll's embedded manifest states the wanted version enough? Shouldn't I also use the correct import library (msvcrt.lib) belonging to the older (4053) CRT dll (msvcr80.dll) when building my dll (with ignore specific library)? How is this import library (msvcrt.lib) changed with minor version changes like this?
Thanks in advance!
Marc Maussen
The CRT version number is declared in vc/include/crtassem.h. For MFC it is vc/atlmfc/include/mfcassem.h. For ATL it is vc/atlmfc/include/atlassem.h. If you got the security update installed on your dev machine then these files will be updated. Using #define _CRT_ASSEMBLY_VERSION x.y.z.w (etcetera) before #including any CRT header will override that version number. So does uninstalling the security update.
This is otherwise unwise, the target machine is still going to use the .5592 revision of the DLL if it has the security update installed. It deploys a 'publisher policy' that redirects the version number, ensuring that old programs automatically get patched. Testing the version that runs on your customer's machine is of course always best. And shipping an installer with a known security problem is very rarely appreciated by customers.

Registering a COM control during installation

One of our applications needs to register a COM control during installation. If a newer version of that control is already registered, we don't want to overwrite it with the older. What are the Windows MSI install conditions I would user to control this? Or is there some other 'best-practice' method I'm not aware of?
Thanks
Sounds like your main problem is that you have two controls that support the same CoClass's, but live in different file paths. That's not a great situation to be in. If at all possible, there should only be one possible file path for a binary that implements a particular COM class.
That way, file versioning rules will make sure that the latest file is installed by MSI installers. MSI won't by default overwrite newer file versions with older ones.
There are applications out there that have the problem that customers need to use the older version of a class occasionally while still having the newer version installed and available. One solution is to have a utility application that the customers can run that will "point" the COM registry entries to the correct binary.
There are definitely permissions issues with implementing that correctly on non-administrative accounts and you should avoid putting yourself in that situation if at all possible.
If you absolutely must have multiple binaries implementing the same COM CoClass GUID and if it is not too late to change old clients, you could create a master "factory" class that takes whatever data/info is available from the client and chooses the correct implementation to return. It would simply be a COM class with an interface that had methods that returned interface pointers to the actual interface the clients needs after allocating the proper implementation class and queryinterfacing for the client interface.
edit
You may choose to change the location of your application from version to version (e.g. "c:\program files\My App V2". That's okay so long as you use the MSI product code and version #, etc. attributes of your packages to force MSI to uninstall any existing versions of your application before installing new ones.
What you are missing here is merge-modules. Basicly you create a merge-module for your COMxx component. This gets recompiled with each new version 19, 20, 21, ... of your component (but keeps its GUID). Both your applications "reference" this COMxx merge-module and ship its content to the user.
This way windows installer will make sure your dll is refcounted and upgraded only if needed, provided you maintain (increase) version info in your dll.
Edit: The merge-module also hard codes install path, which usually ends up somewhere in C:\Program Files\Common Files\{My Company}\{My Component}, both applications ship it there.