Using custom DLL with Inno-Setup - c++

I am having trouble getting Inno-Setup to load my DLL.
I have looked at similar posts, but none of the solutions offered in those seem to help.In particular, this post came very close, but does not seem to be quite the same issue.
My installer runs just fine on my test system. My DLL is written in C++, using VS 2010. There is a DEF file. I have been successful using the VS debugger to attach to the installer's thread and step through my code. Everything is good. The release version runs just fine on my test system with no debuggers involved. Setup calls my DLL and it works.
Then I take my installer to a different, pristine system to try it out. Every time, when I launch the installer, it starts off with the usual UAC prompt: "Do you want to allow the following program from an unknown publisher to make changes to this computer?" And I say "Yes." Then I get a beep and an alert that says:
Runtime Error (at -1:0):
Cannot import
dll:<utf8>C:\Users\Logicrat\AppData\Local\Temp\is-4E245\MyDLL.dll
In my setup script I have
[Files]
Source: "MyDLL.dll"; DestDir: "{app}"; Flags : dontcopy
and
function MyFunc(hWnd: Integer; lpText, lpCaption: AnsiString; uType: Cardinal): Integer;
external 'MyFunc#files:MyDLL.dll stdcall setuponly';
According to the Inno documentation, the dontcopy flag is appropriate if the DLL is not needed for uninstall, which it is not.
I suspect the problem lies in designating exactly where the DLL is supposed to be, as I my script calls for it to be in the {app} directory, yet the error message refers to a temp directory. I've tried a number of variations of the script, all with the same results.
Both my development/test system and my pristine target system are Windows 7 (32-bit). I have been banging on this for weeks with no visible progress. Any suggestions will be most welcome.

Problem solved, thanks to the suggestion by TLama about checking dependencies. When I had initially created the new project for my DLL in MS Visual Studio 2010, I had selected the option to "Use MFC in a shared library." That turned out to be the source of the problem, as the DLL itself was then dependent on mfc100u.dll and msvcr100.dll, which were not present on the target system I used to test my installer. I fixed it by changing the project preference to "Use MFC in a static library." That made the DLL larger, but it also made it work. Then, after I first rebuilt the DLL and then rebuilt the installer that used it, everything was fine.
It might have been nice if the error message I got the first time around named the DLL it was looking for instead of the DLL that tried to call the missing one.

Related

Q: Proper way to access data in a data only dll file

My application store some data in data only dll files. Those dll files are loaded with LoadLibrary() when needed at runtime and then discarded with FreeLibrary() after finish using them. The main application access the data stored in the dll files using GetProcAddress(). The program is written in C++ and uses WinAPI calls, no MFC or other libraries. It has two versions x64 and x86. It works fine on most systems. My dll files do not call other libraries or depend on anything else. Each is a stand alone file.
Recently, I discovered the program does not work on one machine. this specific one has Windows 10 x64 installed on it. After investigations I found the following:
LoadLibrary() fails with error message "Could not find module". The dll is in same directory with main program.
I replaced the call to LoadLibrary() with LoadLibraryEx() and tried the following falgs:
LOAD_IGNORE_CODE_AUTHZ_LEVEL did not work. The dll could not be loaded.
DONT_RESOLVE_DLL_REFERENCES ... works?? But, Microsoft strongly recommends not to use it.
LOAD_LIBRARY_AS_DATAFILE_EXCLUSIVE ... loading the dll succeeds?? But, the call to GetProcessAddress later fails. the program could not access the data in the dll file. So this is not actually working.
I could not find anything wrong with this machine. All other programs are working fine.
I tried the x86 version on this machine and it worked fine using original LoadLibrary().
My installer is dual system and automatically installs x64 version when it finds x64 windows. Normal user can not simply switch to x86 when he gets such error.
My question is how can I eliminate this error and make my program works on any machine:
Should I call LoadLibraryEx() using DONT_RESOLVE_DLL_REFERENCES flag and ignore Microsoft warning?
Is there any way I can get my library loaded with simple call to LoadLibrary()?
If I call LoadLibraryEx() with LOAD_LIBRARY_AS_DATAFILE_EXCLUSIVE flag, as recommended by Microsoft, how can I access the data without calling GetProcessAddress()?
Thank you in advance.

How to set up Visual Studio to debug a DLL ("Unable to start program error")

Basically, I have a Visual Studio project that builds a DLL (a VST audio plugin). Where this type of project scenario has been set up for me in the past, I would be able to build, run, and debug the plugin. Visual studio would automatically launch whichever program I was using to host the plugin. I am trying to achieve the same effect in my current project, but I don't know how to set that up. Currently when I build and run my DLL in Visual Studio, I get the error "Unable to start program". The DLL still builds, and I can still run it, but I can't debug it from Visual Studio, because I don't know what I need to do in my project settings to make this happen. How can I do this?
MORE INFO:
What I do know is that, in projects where this sucessfully works, there are some modifications made to the Visual Studio project settings under fields marked 'pre-build events' and 'post-build events', so presumably what I want to do is edit these in some way to tell Visual Studio the following: "Hey, before you try and run and debug this DLL, you have to launch another program (my program is called Max.exe), and then you have to wait until that program loads the DLL. Then you can debug! Don't be a stupid computer and try to debug it before it's even loaded in Max.exe..."
What I do not know : EVERYTHING ELSE. This is literally all I know about what I'm trying to do, hense the colourful attempt to talk to a computer in English.
Currently when I build and run my DLL in Visual Studio, I get the error "Unable to start program". This is unsurprising seeing as the project knows nothing about the environment I want to use to test the DLL, but the problem is that I don't have a clue what Visual Studio needs to know. I really don't know enough about programming to understand the implications of what I'm trying to do either. Yes, I did mention those fields marked pre-build and post-build because I remember them being important, but I don't know exactly what or how to write in those fields, and I also do not know if there will be more things I need to tell Visual Studio before this will work.
Q.E.D I'm not actually sure what pre and post build events are, or how they work. And I barely know the first thing about customizing VS project settings. All I know is how to write audio processing code. I felt the need for this disclaimer because typically my questions are met with angry programmers who think I don't do my own research; they fail to realize I am an audio engineer who skipped programming 101. Yes, how to debug a dll is a common question I'm sure, but answers to those questions tend to assume pre-requisite knowledge that I do not have.
You will want to edit the Command field in your project's Debugging properties. Right-click on your project in the solution explorer and click Properties (it's generally the last item). Open the Debugging page under Configuration Properties. The Command field indicates which executable to launch when debugging.
By default this contains $(TargetPath) which refers to the final binary your project compiles. This is useless for DLLs since DLLs are not executable. Change this to the path of whatever third party application you are writing a plugin for.
With this change, launching with debugging will actually launch the third party application and attach the debugger to it. Once the application loads your plugin, you will be able to debug it normally.
For Visual Studio,
In Solution Explorer, right click on project and select Properties.
In Properties, choose Configuration Properties -> Debugging.
For Command, enter the full path of the executable that will be loading your DLL. Fill in the Command Arguments and Working Directory accordingly.
In addition, you need to make sure that the executable actually loads the DLL you are building. A mistake that a lot make is to launch their executable, and not realize the executable is loading another version of the DLL they are trying to debug. This can happen due to Windows searching for the first DLL that it finds using the DLL searching logic (exe directory, path, etc.).

REGSVR32: the module "xxxxx.dll" failed to load ... dependent assembly could not be found

I'm having an issue with regards to registering a *.dll under Windows 7 x64.
I've tried placing the *.dll in both, C:/Windows/System32 and C:/Windows/SysWOW64 and attempting to register with "regsvr32 xxxxx.dll" under an elevated command prompt. I also tried to register it from a seperate directory. It responds with the following error:
The module "xxxxx.dll" failed to load.
Make sure the binary is stored at the specified path or debug it to check for problems with the binary or dependent .DLL files.
The application has failed to start because its side-by-side configuration is incorrect. Please see the application event log or use the command-line sxstrace.exe tool for more detail.
The EventLog notes:
Activation context generation failed for "C:\(path-to-dll)
Dependent Assembly
Microsoft.VC90.ATL,processorArchitecture="x86",publicKeyToken="1fc8b3b9a1e18e3b",type="win32",version="9.0.21022.8" could not be found.
Please use sxstrace.exe for detailed diagnosis
N.B. I have installed both x86 and x64 Microsoft Visual C++ 2010 Redistributables.
An interesting aside is that I attempted to register the same *.dll on my work x64 Windows 7 laptop and it registered as expected. I guess this leans towards the fact that some kind of C++ dependency is missing / ATL related?
If anyone could help point me in the right direction or shed any additional light on the matter; i'd be more than grateful.
Regards.
This is almost certainly due to a missing dependency. Use a tool like Dependency Walker to find the required dependencies of the DLL. Or, if the DLL is supplied by a third party, read their documentation which should specify the required dependencies.
Note that Microsoft.VC90.ATL indicates version 9 of MSVC which is VS2008. So you would need to install the MSVC 2008 runtime to meet that dependency. It looks like you installed the MSVC 2010 runtime by mistake.
Finally, please don't put files into the system directory. It belongs to the system and should not be modified by you.
Dependent Assembly
Microsoft.VC90.ATL,processorArchitecture="x86"
This indicates missing Visual C++ runtime module (see Visual C++ Libraries as Shared Side-by-Side Assemblies). It is available as redistributable installer (this is presumably the one you need; x86 variant), which you need to install before registering your DLL (which is in turn dependent on missing component).
There is also another reason why this fails. I just ran into this myself. I was using API methods that did not support Windows 7, such as PathCchRemoveFileSpec which I had to update to the older, deprecated PathRemoveFileSpec. I used Dependency Walker to verify this was the cause. Dependency Walker lies a bit. If you look at my screenshot (below), the red section shows the actual problem - the methods it wasn't able to resolve in DLLs it has, etc. - but the blue shows DLLs that are actually not the problem at all (these DLLs exist). Since Dependency Walker is so old, it lies a bit (its outdated, it thinks something isn't available from time to time), but usually, it also tells the truth...you just have to scroll down a bit from the top left pane like I did. Note to self: please scroll down next time. Anyways, once I ditched pathcch.h, everything worked on 7. Happy coding.
I got relieved from this error message. In my binary path, I had a SPACE. Just replaced the SPACE with UNDERSCORE(_). It worked for me.
as i have also faced the same issue while registering the x.dll through Regsvr32,there is one of the possible reason is that x.dll might be unmaged dll.
To use unmanged dll export function in the dot net code, you have to use Dllimport.

Load a DLL from another directory at program start

My basic issue is this: my program (MyProgram.exe) has a dependency on a DLL from another program (OtherProgram), and I'm trying to avoid repackaging a new DLL every time OtherProgram updates. I'd like to have MyProgram.exe link in OtherProgram's DLL when it launches, but I'm not completely sure that Windows allows for this. So if there is some kind of workaround that would also be acceptable.
And just for some background, the platform is Windows 7 x64, and MyProgram.exe runs fine when I create a symlink in the MyProgram.exe project directory to the DLL in OtherProgram's install directory. When I try to run it without the symlink, I get the "program can't start because OtherProgramDLL.dll is missing from your computer" error.
Any advice or links to relevant info is greatly appreciated!
EDIT: Clarification: the DLL is not linked at compile-time, this issue crops up at runtime
There are two types of dynamic linking in the Windows world:
Load-Time linking is when a DLL is loaded automatically when your program starts up. Windows finds this DLL using a specific algorithm I'll discuss below.
Run-Time linking is when you specifically load a DLL by calling LoadLibrary in your code. Similar rules apply as to how the library is found, but you can specify a fully-qualified or relatively-qualified path to control the search.
In the case of Load-Time linking, MS recommends that your program's DLLs are stored in and loaded from the same directory where your application is loaded from. If this is at all workable, this is probably your best option.
If that doesn't work, there are several other options, outlined here. One is to leverage the search order by putting the DLL in either the working directory or the directory where the application was loaded from.
You can change the working directory of an application by:
Create a shortcut to your application.
Bring up the shortcut's properties
Edit the "Start in" property with the directory where the DLL is located.
When you launch your application using the shortcut, it will load the right DLL.
Other options for load-time linking include:
Adding a manifest to your application which specifies where your dependent assemblies are, or,
Setting the PATH.
You could use LoadLibrary, but you would need a way to guarantee the DLL's location. This Wikipedia article provides good example on how to use the DLL after it has been loaded.
You can add the directory where the dll is located to the PATH environment variable.
I have struggled with the same problem and also found a dead end with the suggested methods like LoadLibrary, SetDllDirectory, Qt's addLibraryPath and others. Regardless of what I tried, the problem still remained that the application checked the libraries (and didn't find them) before actually running the code, so any code solution was bound to fail.
I almost got desperate, but then discovered an extremely easy approach which might also be helpful in cases like yours: Use a batch file! (or a similar loader before the actual application)
A Windows batch file for such a purpose could look like this:
#echo off
PATH=%PATH%;<PATH_TO_YOUR_LIB>
<PATH_TO_YOUR_APP_EXE>
/edit: Just saw #SirDarius comment in Luchian's answer which describes that way, so just take my batch code bit as a reference and all credits go to him.
I have the same problem with one application I am working on.
I do not want to use runtime loading because there are tens of functions I would need to manually create function pointer for.
Mr Dibling's mention of manifest file opened a new door for me but I sadly found out that the oldest version of windows that supports the feature is Windows 7. It won't even work on Vista.
Long story short, a friend familiar with Windows Application development told me to look up Delay-Loaded DLL, which turns out to solve the problem perfectly with minimal effort. It delays the loading of DLL library to either the point you manually do, or the first time its function is called. So you just need to add your DLL path to the search path before that happens, where SetDllDirectory helps.
Here is the steps to make it work:
1) Specify the DLL to be delay-loaded to linker, either through your makefile, cmake or VS property page (Linker->Input of VS2015)
2) Call SetDllDirectory at the beginning of your program, before any call to the DLL is made.
Delay-loaded DLL is supported all the way back to VC6.
SetDllDirectory is supported after XP SP1.
Use Symbolic Links to the 3rd Party Executables
I found the approach advocated by Aaron Margosis useful. See:
Using NTFS Junctions to Fix Application Compatibility Issues on 64-bit Editions of Windows
Essentially, create symbolic links to each of the dependent 3rd Party executables. Place these symbolic link files in and amongst your own dependent executable files. Except for filename changes to the targets, the 'soft' symbolic links will resolve the load-time dependencies even as the target of the links are changed by future updates.

Why is my DLL failing to register?

I am building a project in VS2005 and several of my DLLs are failing to register. The error message I am getting in Visual Studio is:
Project : error PRJ0019: A tool returned an error code from "Registering ActiveX Control..."
which is nicely vague. When I register the DLL manually through the command line (using regsv32.exe, I get the following error:
LoadLibrary("test.ocx") failed - This application has failed to start because the application configuration is incorrect. Reinstalling the application may fix the problem.
I ran Dependency Walker (depends.exe) on the culprit .ocx file but it isn't showing any obvious problems.
I have also done a re-build but I'm still getting the same problem.
Any suggestions as to how I could determine the cause of this failure to register?
Microsoft had recently released a Security Update for ATL (KB971090). It is un update on top of MSVS2005sp1 and it's both compilate-time and runtime compatibility breaker. Check if your building environment has this patch.
References:
ATL Security Update:
http://msdn.microsoft.com/en-us/visualc/ee309358.aspx
Breaking changes in ATL:
http://msdn.microsoft.com/de-de/library/ms235654.aspx
And this is a must read:
http://tedwvc.wordpress.com/2009/08/10/avoiding-problems-with-vc2005-sp1-security-update-kb971090/
Most probable is because the embedded manifests. You should take a resource explorer application and check your DLLs for the embedded manifests. It might be that one of the dependent DLLs (or your DLL) require some versions of other DLLs which don't exists.
I got this message: "This application has failed to start because the application configuration is incorrect." in case of embedded manifest mistmatches.
Probably the easiest way to troubleshoot this whole category of problem is to install Process Monitor from microsoft.com.
Process Montior lets you observe the system calls processes are making, and in this case you will be able to see if some system call is failing. For example, if you are lacking a dependency, then a CreateFile() call will be seen failing with a DLL, OCX, etc. as the filename.
Launch procmon and configure the filter to exclude events other than from regsvr32.exe, reproduce your test case, and then check the log. Look for NAME_NOT_FOUND errors in the return value column.
Do you have the C++ Redistributable Package Installed?
There are several things you can try:
try regsvr32 w/ fusion log enabled (fuslogvw.exe - it works for unmanaged dlls as well). This would give you a bit more information than depends on what external dependencies are loaded, where are they loaded from and what errors were hit.
copy the .ocx and its dependencies to the root or a first level folder and try registering from there. I don't remember details, but there was an old problem with registering a COM dll from within too deep of a path.
run regsvr32 under WinDbg. Set a breakpoint DllMain and see if it does anything funky.
If you never break on DllMain in WinDbg, set a breakpoint on module load for your dll and once it's hit, you can either step through LoadLibrary, or just set a generic load library breakpoint and check every dll after that.