System and method for providing run-time type checking

• US 7,000,151 B2
• Filed: 07/18/2002
• Issued: 02/14/2006
• Est. Priority Date: 07/18/2002
• Status: Active Grant

• Current Assignee: Valtrus Innovations Limited (f/k/a Dolya Holdco 9 Limited) (Key Patent Innovations Limited)
• Original Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Inventors: Dwyer, Lawrence D. K. B.
• Primary Examiner(s): Beausoliel, Robert
• Assistant Examiner(s): Puente, Emerson
• Application Number:
  US10/198,776
• Publication Number:
  US 20040015748A1
• Time in Patent Office: 1,307 Days
• Field of Search: 714/38, 714/52, 717/126, 717/127, 717/141
• US Class Current: 714/38.14
• CPC Class Codes: G06F 11/1004 to protect a block of data words, e.g. CRC or checksum G06F11/1076 takes precedence; security arrangements for protecting computers or computer systems against unauthorized activity G06F21/00
• CPC Class Codes: G06F 11/3612 by runtime analysis performance monitoring G06F11/3466
• CPC Class Codes: G06F 8/437 Type checking

Abstract

The present invention provides systems and methods for providing run-time type checking to prevent software errors. In architecture, a representative system includes a compiler that parses a program and further comprises a logic that generates a checksum for a block of code in the program, a logic that stores the checksum in the block of code, and a logic that inserts checksum instruction code into the block of code. The present invention can also be viewed as a method for providing run-time type checking to prevent software errors. A representative method operates by generating a checksum for a block of code in the program, and storing the checksum in the block of code. During execution of the program, a run-time checksum is generated for the block of code, and the block of code is executed if the checksum equals the run-time checksum, and the execution of the block of code is skipped if the checksum does not equals the run-time checksum.

Claims

1. A method for providing run-time type checking comprising steps of:

generating a checksum corresponding to the form of an object in a program;

storing the checksum in the object;

computing a run-time checksum corresponding to the form of the object during execution of the program;

executing the object if the checksum equals the run-time checksum; and

skipping execution of the object if the checksum does not equal the run-time checksum.

2. The method of claim 1, wherein the generating a checksum step further comprises:

allocating area for the generated checksum.

3. The method of claim 1, wherein the generating a checksum step further comprises:

inserting the checksum in the object.

4. The method of claim 1, further comprising the step of:

inserting checksum instruction code into the object.

5. The method of claim 1, wherein the generating a checksum step further comprises:

using a parameter to generate the checksum, wherein the parameter comprises a base address of the object, number of elements in the object, type of the elements in the object, and order of the elements in the object.

6. A system for providing run-time type checking, comprising:

means for generating a checksum corresponding to the form of an object in a program;

means for storing the checksum in the object; and

means for computing a run-time checksum corresponding to the form of the object during execution of the program, wherein the computing means executes the object if the checksum equals the run-time checksum, and skips execution of the object if the checksum does not equal the run-time checksum, said means for computing comprising a processor.

7. The system of claim 6, wherein the generating means further comprises:

means for allocating area for the generated checksum.

8. The system of claim 6, wherein the generating means further comprises:

means for inserting the checksum in the object.

9. The system of claim 6, wherein the generating means further comprises:

means for inserting checksum instruction code into the object.

10. The system of claim 6, wherein the checksum is generated using a parameter, wherein the parameter comprises a base address of the object, number of elements in the object, type of the elements in the object, and order of the elements in the object.

11. A computer readable electronic storage medium executing computer readable instructions for providing run-time type checking, comprising:

logic for generating a checksum corresponding to the form of an object in a program;

logic for storing the checksum in the object; and

logic for computing a run-time checksum corresponding to the form of the object during execution of the program, wherein the computing logic executes the object if the checksum equals the run-time checksum, and skips execution of the object if the checksum does not equal the run-time checksum.

12. The computer readable medium of claim 11, wherein said logic for generating a checksum further comprises:

logic for allocating area for the checksum.

13. The computer readable medium of claim 11, wherein said logic for generating a checksum further comprises:

logic for inserting the checksum in the object.

14. The computer readable medium of claim 11, wherein said logic for generating a checksum further comprises:

logic for inserting checksum instruction code into the object.

15. The computer readable medium of claim 14, wherein the checksum is generated using a parameter, wherein the parameter comprises a base address of the object, number of elements in the object, type of the elements in the object, and order of the elements in the object.

16. A system for providing run-time type checking, comprising:

a compiler that parses a program, wherein the compiler further comprises;

logic that generates a checksum corresponding to the form of an object in the program;

logic that stores the checksum in the object; and

logic that inserts checksum instruction code into the object.

17. The system of claim 16, wherein the compiler further comprises:

logic that allocates area in the object for the checksum.

18. The system of claim 16, wherein the compiler further comprises:

logic that inserts the checksum in the object.

19. The system of claim 16, wherein the checksum is generated using a parameter, wherein the parameter comprises a base address of the object, number of elements in the object, type of the elements in the object, and order of the elements in the object.