Re: Question about EDGE_ABNORMAL_CALL edges in cfg

[Jim Wilson <wilson at specifixinc dot com>]

Steven Z wrote:
> Can anyone help me with EDGE_ABNORMAL_CALL? It defines
> one kind of edges between basic blocks. My question is
> when and where this kind edge will be built for what
> kind of c program. I have several c programs that
> generate EDGE_ABNORMAL_CALL edges and I plan to change
> this kind of edges into normal function call and
> returns. Is this possible at all?

If it was possible to eliminate them, then we would have already done that.

Consider a call to a C++ function that throws an exception in scope of a 
catch handler.  It will "return" to the handler.  It will not return to 
the point where it was called.

GNU C allows nested functions, and it allows nested functions to branch 
to labels in the parent function.  These are called non-local gotos. 
Consider a call to a nested function that exits by branching to a label 
in the parent.  It will "return" to the label.  It will not return to 
the point where it was called.
--
Jim Wilson, GNU Tools Support, http://www.SpecifixInc.com