Source Code Inspection and Software Reuse Chapter 7

Source Code Inspection and Software Reuse Chapter 7 – Digging into source code Coder To Developer - Mike Gunderloy Respected Professor: Dr. James Fawcett Presented By: Ghanashyam N

Digging Into Source Code § Looking more deeply at available code can clarify several details that are not immediately evident regarding this code’s functioning § Code inspection helps us use existing code efficiently § Seeing how someone else solved a particular problem can be very helpful in producing more elegant and efficient code

. NET Fundamentals § All. NET code is executed by the CLR § Each of the. NET language compilers (C#, VB. NET, Managed C++ etc. ) convert source code into MSIL (and Metadata) § CLR understands only MSIL code and knows nothing about the. NET language that was used to generate this MSIL code

. NET Code Is Open § There are several utilities (Ildasm, . NET Reflector etc. ) that allow you to work on MSIL code directly § Thus it is possible to find out quite a bit about. NET code for a library or an application even if its source code is not available

. NET Code Is Open § All the code for. NET FCL is present in the form of MSIL (and Metadata) on any machine that has. NET installed § Thus it is possible to look more closely at the implementation of the. NET FCL § Looking at code for the. NET FCL can prove extremely useful especially when the documentation for a certain FCL class or method is obscure

Using Ildasm § The. NET Framework SDK comes with a tool named Ildasm that allows you to work directly with MSIL code § It displays MSIL code in a somewhat human readable format § Ildasm’s output cannot be easily deciphered even though it is much more readable than MSIL itself

Using Ildasm § Start Menu ► Programs ► Microsoft Visual Studio. NET 2003 ► Visual Studio. NET Tools ► Visual Studio. NET 2003 Command Prompt § Type ‘ildasm’ on command prompt and press enter

Using. NET Reflector §. NET Reflector is available at http: //www. aisto. com/roeder/dotnet § It is much easier to use than Ildasm since it displays the source code that was used to generate a supplied. NET assembly § It also has many useful features like decompilation to either C# or VB. NET and display of call trees for any selected method

Reflection | Obfuscation § MSIL, Metadata and Reflection make it possible to do a deep analysis of any. NET application or library, even without source code § Obfuscation aims at protecting intellectual property by taking source code and automatically changing it to make it difficult to understand § Obfuscators typically change class names, member names etc. in the source code to make it very difficult to decipher the assembly generated using this code

Some Obfuscators § Demanor for. NET http: //www. wiseowl. com/products/Products. aspx § Salamander http: //www. remotesoft. com/salamander/obfuscator. html § Dotfuscator http: //www. preemptive. com/dotfuscator/index. html § Species. NET http: //www. 9 rays. net/cgi-bin/components. cgi

Experimenting With Code § There are times when you need to actually run the code to gain a complete understanding of its functioning § But writing a complete VS. NET solution to test the behavior of a simple component is a lot of work

Experimenting With Code § Snippet Compiler http: //www. sliver. com/dotnet/Snippet. Compiler/ § An IDE that allows you to write code to exercise some small piece of code with minimal overhead § Supports C# and VB. NET § Supports Winforms and ASP. NET § Modest set of features § Gets code up and running quickly

Software Reuse § Try to avoid “reinventing the wheel” § Try and find code that you don’t have to write § There is an astonishing amount of free, high-quality, reusable code out there

Software Reuse § Make full use of the. NET FCL § Code for most of the common programming tasks already exists in the FCL § § § Hashtables, queues etc. – System. Collections Event log, performance counters – System. Diagnostics WMI – System. Management XML – System. XML Sending SMTP mail – System. Web. Mail Reqular Expressions – System. Text. Regular. Expressions

Software Reuse § Some Libraries § SQLXML Library http: //www. msdn. microsoft. com/sqlxml/ Add-on XML functionality for Microsoft SQL Server 2003 § WSE (Web Services Enhancements) http: //www. msdn. microsoft. com/webservices/buildin g/wse/default. aspx Set of implementations of web services specifications such as WS-Security, WS-Routing, WS-Referral etc.

Software Reuse § Some Libraries § Logidex. NET Library http: //www. msdn. microsoft. com/sqlxml/ Add-in to VS. NET that lets you locate and download. NET patterns and sample code from within Visual Studio. NET

Software Reuse § More sources of free code § The Code Project http: //www. codeproject. com § Got. Dot. Net User Samples http: //www. gotdotnet. com/Community/User. Samples

Evaluating Code § Using Fx. Cop http: //www. gotdotnet. com/team/fxcop § A code analysis tool that checks. NET managed code assemblies for conformance to the Microsoft. NET Framework Design Guidelines § Can check conformance for third party libraries as well as own classes

Thank You