Abstract: A method instruments a function in an executable file so that the instrumented function calls a generic preprocessor prior to execution of the body of the function. After the preprocessor modifies the original function's incoming parameters, the body of the function itself is executed. Finally, execution is directed to a generic postprocessor prior to returning from the function. The postprocessor modifies the outgoing parameters and return value. In one implementation, the parameters of an instrumented function are described and packaged into a descriptor data structure. The descriptor data structure is passed to the generic preprocessor and postprocessor. A generic processor uses the descriptor to select changed behaviors based on the calling context.

Abstract: This invention provides a system and method for instrumenting an executable file by replacing an original function in the executable file with a user-supplied function and enabling the user-supplied function to invoke the original function. In particular, the executable file includes an access to the original function. To instrument the executable file, the access to the original function is replaced with an access to the user-supplied function. Access information associated with the original function is retained, which enables the user-supplied function to locate the original function.

Abstract: A method instruments a function in an executable file so that the instrumented function calls a generic preprocessor prior to execution of the body of the function. After the preprocessor modifies the original function's incoming parameters, the body of the function itself is executed. Finally, execution is directed to a generic postprocessor prior to returning from the function. The postprocessor modifies the outgoing parameters and return value. In one implementation, the parameters of an instrumented function are described and packaged into a descriptor data structure. The descriptor data structure is passed to the generic preprocessor and postprocessor. A generic processor uses the descriptor to select changed behaviors based on the calling context.