Method and apparatus for handling calls from relocated instrumented functions
to functions that expect a return pointer value in an original address space. In
various embodiments of the invention, instrumented versions of selected functions
of an executable program are generated and stored in a relocation address space.
When a function is called by a function in the relocation address space, a return
pointer register stores a first return-pointer value that is an address in the
relocation address space. The address in the original address space that corresponds
(logically) to the first return-pointer value is identified as an original return-pointer
value. The first return-pointer value is associated with the original return-pointer
value, references to the original return-pointer value are substituted for references
to the first return-pointer value, and the instruction at the address indicated
by the original return-pointer value is replaced with a breakpoint. When the breakpoint
is encountered upon return of control at the original return-pointer value, the
first return-pointer value that is associated with the original return-pointer
value is obtained, and control is transferred to the instruction at the address
referenced by the first return-pointer value.
