[Soot-list] What is the difference between getMethod() and getMethodRef()?

[Patrick Lam]

On 01/25/13 17:03, Marc-Andre Laverdiere-Papineau wrote:
> Hello,
>
> I have been plagued with weird exceptions like this:
>
> Exception in thread "main"
> soot.SootMethodRefImpl$ClassResolutionFailedException: Class
> javax.servlet.ServletContext doesn't have method getContextPath([]) :
> java.lang.String; failed to resolve in superclasses and
> interfacesLooking in javax.servlet.ServletContext which has methods
> [<javax.servlet.ServletContext: javax.servlet.ServletContext
> getContext(java.lang.String)>,<javax.servlet.ServletContext: int
> ...<javax.servlet.ServletContext: javax.servlet.Servlet
> getServlet(java.lang.String)>,<javax.servlet.ServletContext:
> java.util.Enumeration getServlets()>,<javax.servlet.ServletContext:
> java.util.Enumeration getServletNames()>,
> ...
> <javax.servlet.ServletContext: void
> log(java.lang.String,java.lang.Throwable)>,
> <javax.servlet.ServletContext: java.lang.String
> getRealPath(java.lang.String)>,<javax.servlet.ServletContext:
> java.lang.String getServerInfo()>,<javax.servlet.ServletContext:
> ...<java.lang.Object: void wait()>,<java.lang.Object: void finalize()>,
> <java.lang.Object: void<clinit>()>]
>
> 	at soot.SootMethodRefImpl.resolve(SootMethodRefImpl.java:179)
> 	at soot.SootMethodRefImpl.resolve(SootMethodRefImpl.java:105)
> 	at
> soot.jimple.internal.AbstractInvokeExpr.getMethod(AbstractInvokeExpr.java:54)
> 	at ...
>
> It happens if I have something like this:
> ((DefinitionStmt)u).getInvokeExpr().getMethod()...
>
> However, changing it to getMethodRef() won't break - why??? (Sidenote: I
> am running without exclusions)

Well, if you are just getting the MethodRef, you don't need the method 
to be resolved. It's analogous to requesting a pointer to the method 
without dereferencing it.

Taking a broader view, it seems like you have weirdness in your input 
files where you have references to nonexistent methods. Do you need to 
do anything with all of the methods that you're referencing? If not, 
getMethodRef() should be fine.

pat