Compare compiled .NET assemblies?

Danny_G_76302 0
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Are there any good programs out there to compare to compile .NET assemblies?

For example I have HelloWorld.dll (1.0.0.0) and HelloWorld.dll (2.0.0.0), and I want to compare differences how can I do this?

I know I can use .NET Reflector and use the Assembly Diff plugin. Are there any other good tools out there to do this?

reverse-engineering vb.net debugging .net c#
7 Answers

Ways to Compare .NET Assemblies suggests

Commercial:

Free:

Existing compare tools like Beyond Compare (commercial) can do this by special configuration. Here's how to do this for Beyond Compare:

  • Go to Tools → Options
  • Click New.., select "Text format", click OK
  • Give it a name (say, EXE, or DLL), and specify the mask as *.exe or *.dll
  • Click on tab Conversion and select "External program (Unicode filenames)"
  • Under "Loading", specify the path to ildasm and add %s /OUT:%t /NOBAR (i.e.: C:\Program Files (x86)\Microsoft SDKs\Windows\v10.0A\bin\NETFX 4.8 Tools\ildasm.exe %s /OUT:%t /NOBAR)
  • Make sure to check disable editing.
  • Click Save, then Close
  • Restart BC and open two exe files to compare, it should decompile into ilasm automatically now.

You can also add syntax highlighting to this new format. I plan to send the syntax file to them so that it'll become available to share.

xvb_620550

Two ways.

You could ILDASM and diff with classic tools.

Or you could use NDepends, which will cost for that feature.

[Piece to C# bloaters..]

Reoa_752480

I just had to compare two revisions of the same DLL, which had the same version (I needed to implement a small hotfix, and deploy the DLL in production, but I wanted to make sure that no other changes leaked into code). Ideally, I would want the Assemby Diff add-in to show me the difference, but it does not work (it thinks that I'm comparing a DLL to itself). So this is what I did:

  • Created two folders to hold disassembled source files.
  • Used the Reflector's Export option (from context menu) to generate source files from each DLL in the folders created in previous step.
  • Used the free DiffMerge tool to compare two directories; the tools showed me the modified files and the difference.

It's a bit kludgy, but seems to work. I wish the Assembly Diff add-in worked, though.

UPDATE: The latest version of the Assembly Diff add-in is supposed to fix the issue of comparing two versions of the same assembly. Give it a try.

user_525450

Here's a thinking outside the box approach whcih works fine.

  1. Dump your old and new assemblies with dnSpy, dotPeek or JustDecompile into projects.

  2. Create a new Git repo and commit the old assembly code first.

  3. In your local repo folder delete all the files/folders except for ".git" and paste the new assembly files.

  4. Either commit the new changes and view changes on say Github or use a Git viewer like Fork. Easy code comparison for free.

user_142570110
Jonathan_Parker_45040
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