Detecting unused code across multiple assemblies

We have an investigative set of re-factoring rules in development here, one check does what you describe. The check requires that you analyze a complete set of binaries which should, taken together, make use of all available public API. This might be a tall order for your case, since you have 247 binaries.

In any case, you can use the CallGraph static class to retrieve callers for a particular method:

MethodList callers = CallGraph.CallersFor(method);

If the length of the returned method list is > 0, there is at least one caller for the item. You'll likely also want to use a couple of other rule utility helpers to reduce noise. If the method is specially invoked (for example, if it's a public static Main entry point), you won't want to flag it. Neither will you want to flag overrides of virtual methods (since calls to overrides aren't typically emitted by compilers, a call site to the base definition is emitted instead).

RuleUtilities.IsSpeciallyInvoked(method)
RuleUtilities.IsOverride(method)

Michael Fanning
VSTS Development: Code Analysis

Hi,

does the call MethodList callers = CallGraph.CallersFor(method); return the callers from all assemblies listed as targets in the FxCop project, or is it restricted to the callers within the same assembly?

Recently I implemented a dead code detector against the Reflector API and now want to add such a custom rule to FxCop.

One possible application of this rule are prototypes that want
to implement only a library subset required by a specific application.

thanks,
Roland

Yes, whole program analysis is expensive, this is why I asked. For me this is good, as I can do my task very easily now, at least with the current version.

Maybe you can provide something to merge the callgraphs for assemblies explicitly, which can be done during a breadth first traversal.

Thanks for the information.

greetings,
Roland