Missing .dll when I try to run my application - dll

I have been working with OpenGL (SuperBible) and I just setup my environment (added the additional dependencies, etc.) and built my solution. When I try to execute it it says I am missing a dll. I solved the problem by moving the dll to my folder where the executable resides.
My question is why doesn't it look for it in my System32 folder? Why does it have to be in the folder with the executable. And finally is there a way to make it look for it in the System32 folder?

Check the value of your %PATH% environment variable.
set PATH
If system32 isn't in your path, thats why you can't find the dll.
As for why the DLL must be in the same folder, there are two possible culprits:
1) Your code has a Hard Coded Path to the Dll
2) The DLL isn't in any place that is listed in the %PATH% system variable.

IIRC there is something about registering DLLs. (Truth be told, I avoid DLLs whenever I can so I might be way off base.)

Related

SDL2_ttf can't find entry point unless libfreetype-6.dll is in proj folder

I am working with SDL2 and its add-on libraries SDL2_image and SDL2_ttf, using Visual Studio 2017. The libraries, and the .dll files that come with them, are in another folder (C:\SDL2.0\lib\x86), which is in the system path.
When I run, it fails, with this error message:
The procedure entry point InterlockedCompareExchange#12 could not be located in the dynamic link library C:\SDL2.0\lib\x86\SDL2.ttf.dll.
I can fix this by putting libfreetype-6.dll, which comes with SDL2_ttf, in the same folder as the .vcxproj file; or in the Debug folder. I can also fix it by putting the .dll into c:\windows\SysWOW64. But I want to distribute my code, and I don't want to put that file in each folder or require users to have admin access (to access c:\windows\SysWOW64); I want Windows to find it in the PATH, as it does with the other .dll files it's using here.
A few things I tried as I looked around the web for solution (to no effect):
Recompiling libfreetype-6.dll
Downloading the latest versions of all associated libraries
Rearranging the .lib files in Project Properties, Linker, Input, Additional Dependencies. Admittedly I may not have tried all possible arrangements as there are several dependencies
regsvr32 libfreetype-6.dll. This led to a different error message:
The module "libfreetype-6.dll" may not be compatible with the version of Windows that you're running. Check if the module is compatible with an x86 (32-bit) or x64 (64-bit) version of regsvr32.exe.
I saw here that maybe I should use the version of regsvr32 in the system32 folder; when I do that, I get
The module "libfreetype-6.dll" was loaded but the entry-point DllRegisterServer was not found. Make sure that "libfreetype-6.dll" is a valid DLL or OCX file and then try again.
So: is there a way to get the program to find libfreetype-6.dll in another folder in the PATH, and eliminate the error message about the procedure entry point?
The program I'm testing on now is from the TrueType tutorial from the LazyFoo website (source).

WIX: COM registration fails when installing COM dll into another folder

I am using heat to harvest the COM dll and tlb files (let's call them MyLib.*, developed in VB.NET) to do the COM registration. Everything was working fine, when I install MyLib.dll and MyLib.tlb into my application's installation folder, i.e., INSTALLDIR. However, since we want to allow different versions of our SW to be installed on the same machine, and if they are using the same version of COM component, only one copy of the dll (I think each version of our SW should have its own tlb, please correct me if I am wrong) should be installed, we now want to install MyLib.dll into another folder, specifically PROGRAM_FILES\Common Files\SHARED_FOLDER_NAME, so now if one version of our SW is uninstalled, the MyLib.dll will not be removed and can still be used by other versions.
But here comes the problem: my COM registration is just simply not working any more after I install this dll into this another folder, and it keeps saying that can't find file specified when I am calling the COM function which indicates registration failure. In the WIX installer project, everything is the same except this folder for MyLib.dll.
Here is the registry structure after installation:
Firstly I have HKCR\CLSID{MYCLSIDs}, each of them represents one of my COM class. in the sub-key named "InprocServer32", I have Assembly, Class, CodeBase, RuntimeVersion, threadingModel. And the CodeBase is either common file folder (not working) or MyApp's installation folder(working), which is the different locations I put the dll. I thought there would be another sub-key TypeLib under {MYCLSIDs}, since Access only sees the TypeLib and I think there should be some link from the TypeLib to the actual dll, however, at both cases this sub-key is missing but in the second case it is still working. Is there a problem of it?
Secondly I have HKLM\Software\Classes\CLSID{MYCLSIDs}, these keys are of course the same structure as described above.
Thirdly, the HKCR{MYPROGIDs}, these are just ProgIDs of my classes
Fourthly, HKCR\Typelib{LibID}, which includes the information from tlb file, and this ID is from the Assembly GUID of COM component project.
Finally, the HKEY_CLASSES_ROOT\Interface{InterfaceID}, there is sub-keys named ProxyStubClsid32 with value {00020424-0000-0000-C000-000000000046}, and the one named TypeLib and the value is my LibID.
As I mentioned, the only difference is the CodeBase, which stores where MyLib.dll is located. In order to verify that, I did two tests: after I install MyLib.dll into the shared folder, the COM calling fails. But if I replace all the CodeBase values for SHARED_FOLDER\MyLib.dll to INSTALLDIR\MyLib.dll, and copy MyLib.dll into INSTALLDIR, it actually works. Vise versa, after I install MyLib.dll into INSTALLDIR(in which case COM is working), I change the CodeBase values from INSTALLDIR\MyLib.dll to SHARED_FOLDER\MyLib.dll, and make a copy to SHARED_FOLDER, this time it fails. So it seems that it is exactly the installation location's problem, which is the opposite to my understanding of COM. And I don't think there is a permission issue for the SHARED_FOLDER(I could be wrong) since it is in a folder that my installer creates.
Please help, thanks!
It turned out that MyLib.dll is using some other libraries, which are still installed in the MyApp installation folder. And so in that case that MyLib.dll is installed in the shared folder, it tries to find those libraries in the same libraries, which of course fails. When I install those libraries in the shared folder too, it is working.
BTW I found fulogvw.exe very helpful when tracking down the assembly loading problem. For example in my case in the failed log it says can't load file xxx.dll in SHARED_FOLDER, the xxx.dll is some library that MyLib.dll is using, and I had no idea that MyLib.dll needs it until I see the log.

How to access a temporary Exe or DLL from a DLL Custom action (C++ DLL) in MSI/WIX project?

I have two use cases: 1) loading a temporary DLL during a custom action and 2) executing a temporary EXE from a custom action. The custom action DLL is unmanaged C++. I cannot figure out how to get this working correctly. Including the DLL is easy enough but LoadLibrary is failing as it cannot find the DLL. I also cannot seem to get the physical path of the extracted DLL in order to specify full path in LoadLibrary. Any help is appreciated. I'm using WIX btw for this work.
If you have included the dll and the exe in the Binary Table of the msi, the files will be physically present in the %Temp% folder of the currently logged in user which gets mapped to SUPPORTDIR property of Windows Installer.
You need to use MsiGetProperty to get the SUPPORTDIR and use that in the LoadLibrary.
One thing to remember - Windows Installer usually extracts files from Binary table to %TEMP%, however - the current work directory is often set to c:\windows\installer.
My suggestion - extract the temporary .dll from Binary table yourself when you need it. This gives you the control of when it's saved to. Just remember that you need write permission to the location, so usually some subdir of %temp% is the best choice.

Microsoft Visual Studio: How to find where a dll is loaded from?

A wrong version of a dll (MSVCR90d.dll instead of MSVCR90.dll) gets used for the delete operator, causing a crash. In the callstack, only the dll name is shown, not their path. How to see the path?
Edit: I'm building in Release mode, not in debug mode. So why does the debug dll get used? I have seen the same problem reported on many other websites, but could find no working solution.
Yesterday I found using Dependency Walker that the debug dll is getting picked up, so I renamed the dll, then the release version got picked up in the Dependency Walker, and also my program did not crash. I didn't change anything today, but the program has started crashing again. And when I see the dependency walker tree, it shows MSVCR90d.dll (the debug dll) with a question mark, saying it couldn't find it in the path. Why can't it pick up the release dll? Also I don't know from where the debug dll gets used by the runtime.
You can add them in your global PATH environment variable. Refer here
You can specify the dll manually by right clicking on the solution and selecting Add Reference, then browse to the particular dll.
You can add the path to the DLLs to the Executables files settings under Tools > Options > Projects and Solutions > VC++ Directories
For finding out the details of a dll, you might want to use DependencyWalker
However, in your case I think d is being appended to the name of dll, probably because you are creating a DEBUG build, and for that corresponding DEBUG versions of all dlls are loaded.
If you choose to create a RELEASE build, you would not have a d appended to MSVCR90.dll
You don't need to know Dll path, you need to understand why Debug version of delete operator is called. Maybe, _DEBUG constant is defined in Release configuration.

vb.net: how do i build to just one file?

i did a build in vb.net and got one exe file
however, when a user runs the file, it says it is missing one of the libraries (itextsharp).
so the question is, if there is actually a build option in vb.net, why does it not include the library in the same exe file?
You can distribute the iTextSharp DLL with your application. The easiest way to do this is to simply include it in the same folder as your EXE. The DLL should be output to your Project's Debug/Release folder each time you build assuming you've added it as a Reference in your project and the Reference's 'Copy Local' property is set to True.
If you want to distribute one EXE and include the iTextSharp in that, you can use the ILMerge tool (or alternately Gilma from SourceForge) after you build your EXE.
in the properties for the reference set the Copy To Output to Always
ITextSharp is not a library linked in your project output; it's an assembly referenced by your project output. And while VB.Net builds one executable from your source code, the CLR still needs all the referenced assemblies in the same folder as your executable.
To make everything work, you can distribute ITextSharp assemblies along with your app. Alternatively, if you indeed need only one file, you can use ILMerge on your project output and the assemblies you want included. However, you might need to determine all the correct assemblies you need merged. I wouldn't revommend using this tool, unless you understand how it works.
Note: If you want to use ILMerge with .Net v4.0, read this page.