comparing products of builds in release

Question

I need to compare build outputs of VS2005 in order to be sure I can reproduce the exact same product.

when I do two builds one after the other in release and compare the produced files I get different files, doing text comparison it seems that more than just the datetime is different

how can I build in order to reproduce exact same product each time ?

Answer 1

One question: you did text comparison for binary build outputs? As I know most of compilers never produces binary identical build output for the same project. Compiler encodes into binary time of compilation, special ordinal, etc.

Answer 2

Whenever you build, the compiler embeds:

• The date and time
• A GUID (used for debugging etc, I believe)
• Potentially the assembly version (which may have "1.2.3.*" and populated automatically)
• Potentially a strong hash

A couple of options:

• Find out where the files are "known to differ immaterially", wipe those bytes, and then compare
• Use ildasm to convert the assemblies to text, and then compare those results. (I haven't checked whether or not this reveals the differences too - it may do, in which case again you'd have to explicitly ignore certain sections)

This problem does pop up every so often, so I'll see if I can come up with a tool to do the comparisons - although it's unlikely to cope with signed assemblies, as the location of the signature could vary significantly.