System and method for dynamic program linking

Abstract

In a system for dynamically linking a compiled procedure to referenced object components during execution of the compiled procedure, a native code loader loads the compiled procedure into a user's address space, and replaces a first instruction in the compiled procedure that references a first object component with a replacement instruction that invokes execution of a dynamic resolution procedure. While executing the compiled procedure, execution of the replacement instruction invokes execution of the dynamic resolution procedure. The dynamic resolution procedure locates the first object component, replaces the replacement instruction in the compiled procedure with a patch instruction, corresponding to the first instruction, that references the located first object component. The dynamic resolution procedure also resets a program counter value associated with execution of the compiled procedure so that when the dynamic resolution procedure returns back to the compiled procedure, the patch instruction is executed next. In a preferred embodiment, the native code loader replaces a shadow instruction, immediately following the first instruction in the compiled program with a NOP instruction. The dynamic resolution procedure, after it locates the first object component, replaces the NOP instruction with the shadow instruction if the shadow instruction does not reference an object component, and otherwise replaces the shadow instruction with a second replacement instruction that invokes execution of the dynamic resolution procedure.