Identifying factorable code

• US 9,195,810 B2
• Filed: 12/28/2010
• Issued: 11/24/2015
• Est. Priority Date: 12/28/2010
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Inventors: Kirovski, Darko, Livshits, Benjamin, Medvinsky, Gennady, Gajjala, Vijay, Ray, Kenneth, Lind, Jesper
• Primary Examiner(s): Dao, Thuy
• Assistant Examiner(s): HAYIM, SAMUEL E
• Application Number:
  US12/979,933
• Publication Number:
  US 20120167061A1
• Time in Patent Office: 1,792 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: G06F 21/125 by manipulating the program code, e.g. source code, compiled code, interpreted code, machine code
• CPC Class Codes: G06F 2221/2115 Third party

Abstract

Various embodiments are disclosed that relate to the automated identification of one or more computer program functions for potentially placing on a remote computing device in a split-computational computing environment. For example, one disclosed embodiment provides, on a computing device, a method of determining a factorable portion of code to locate remotely from other portions of the code of a program to hinder unauthorized use and/or distribution of the program. The method includes, on a computing device, receiving an input of a representation of the code of the program, performing analysis on the representation of the code, the analysis comprising one or more of static analysis and dynamic analysis, and based upon the analysis of the code, outputting a list of one or more functions determined from the analysis to be candidates for locating remotely.

Claims

1. A method implemented by a computing device, the method comprising:

obtaining a representation of code of a program having multiple functions;

performing analysis on the representation of the code to identify a list of one or more candidate functions from the multiple functions of the program, wherein the list of one or more candidate functions are determined from the analysis to be candidates for locating remotely from a remainder of the code of the program; and

outputting the list of one or more candidate functions determined from the analysis to be candidates for locating remotely from the remainder of the code of the program,

wherein performing the analysis on the representation of the code comprises filtering out certain functions of the multiple functions having relatively fewer recursive data dependencies than other functions that remain in the list of one or more candidate functions after the filtering.

2. The method of claim 1, wherein performing the analysis on the representation of the code comprises filtering out other functions of the multiple functions based on coverage of the other functions.

3. The method of claim 1, wherein performing the analysis on the representation of the code comprises, for the multiple functions of the program, determining amounts of state data that are passed to the multiple functions when called, and performing additional filtering of further functions of the multiple functions from the list of one or more candidate functions based upon the amounts of state data that are passed when the further functions are called.

4. The method of claim 1, wherein performing the analysis on the representation of the code comprises dynamically determining frequencies at which the multiple functions are called in an instrumented version of the code, and performing additional filtering of further functions of the multiple functions from the list of one or more candidate functions based upon the frequencies.

5. The method of claim 1, wherein performing the analysis on the representation of the code comprises determining how frequently individual functions of the multiple functions execute in a main thread of the program, and performing additional filtering of further functions of the multiple functions from the list of one or more candidate functions based upon frequencies at which the further functions execute in the main thread.

6. The method of claim 1, wherein performing the analysis on the representation of the code comprises, for the multiple functions, determining associated latency tolerances based upon differences between first times when outputs of the multiple functions are used minus second times when inputs into the multiple functions are available compared to durations of execution of the multiple functions.

7. The method of claim 1, wherein performing the analysis of the representation of the code comprises first performing static analysis to select a subgroup of the multiple functions from a global list of the multiple functions, and then performing dynamic analysis to filter the subgroup of the multiple functions.

11. The method of claim 1, further comprising configuring one or more individual candidate functions to execute on a server device and configuring the remainder of the code to execute on a client device.

12. The method of claim 1, wherein the analysis comprises static analysis of the representation of the code.

13. The method of claim 1, further comprising:

receiving a user input selecting a selected function from the list of one or more candidate functions, and

in response to the user input, outputting source code for the selected function.

14. The method of claim 1, wherein obtaining the representation of the code of the program comprises receiving one or more of a control flow graph representing the code, a data flow graph representing the code, and an instrumented version of the code.

15. The method of claim 1, wherein performing the analysis on the representation of the code comprises performing additional filtering of further functions of the multiple functions from the list of one or more candidate functions based upon a number of basic blocks in the further functions.

16. The method of claim 1, wherein performing the analysis on the representation of the code comprises performing additional filtering of further functions of the multiple functions from the list of one or more candidate functions based upon a number of times that the further functions write to memory.

8. A computer-readable memory device comprising instructions stored thereon that are executable by a computing device to cause the computing device to perform acts comprising:

receiving a control flow graph of an application program and an instrumented version of code of the application program, the application program having multiple functions;

performing static analysis of the control flow graph of the application program;

based on the static analysis, performing a first filtering of the multiple functions to identify a list of candidate functions that are candidates for remote execution, wherein the first filtering is based at least in part on whether the multiple functions place personally-identifiable information on a remote computing device configured to perform the remote execution;

performing dynamic analysis of the instrumented version of the code of the application program;

based on the dynamic analysis, performing a second filtering of the list to remove at least some candidate functions from the list; and

outputting the list of candidate functions after the first filtering based on the static analysis and the second filtering based on the dynamic analysis.

17. The computer-readable memory device of claim 8, wherein the dynamic analysis is performed by running the application program multiple times and gathering data from instrumentation in the instrumented version of the code.

18. The computer-readable memory device of claim 8, wherein the acts further comprise:

receiving an input selecting a selected function from the list of candidate functions, and in response to the input, outputting source code for the selected function.

19. The computer-readable memory device of claim 8, wherein the first filtering comprises filtering out certain functions of the multiple functions based on whether the certain functions affect a significant number of variables compared to other functions of the multiple functions.

20. The computer-readable memory device of claim 19, wherein the first filtering comprises performing at least one cut of the control flow graph to filter out the certain functions.

9. A computing device, comprising:

one or more processing devices; and

one or more memory devices having machine-readable instructions stored thereon that, when executed by the one or more processing devices, configure the one or more processing devices to;

receive an input of a control flow graph representing code of a program;

receive another input of an instrumented version of the code;

perform static analysis of the code based upon the control flow graph;

determine a subset of functions of the program based upon the static analysis;

using the instrumented version of the code, iteratively perform dynamic analysis on the subset of functions to determine a list of functions potentially suitable for factoring; and

output the list of functions potentially suitable for factoring,

wherein the dynamic analysis is performed iteratively via progressively more computationally-intensive iterations of the dynamic analysis and filtering individual functions of the program from the list after the iterations of the dynamic analysis.

10. The computing device of claim 9, wherein the machine-readable instructions further cause the one or more processing devices to:

receive a user input selecting a selected function from the list of one or more functions, and, in response, output source code for the selected function.