US 20030126590A1
(19) United States
(12) Patent Application Publication (io) Pub. No.: US 2003/0126590 Al
Burrows et al. (43) Pub. Date: Jul. 3,2003
(54) SYSTEM AND METHOD FOR DYNAMIC DATA-TYPE CHECKING
(76) Inventors: Michael Burrows, Palo Alto, CA (US);
Stephen Neil Freund, Menlo Park, CA
(US)
Correspondence Address:
Pennie & Edmonds, LLP
3300 Hillview Avenue
Palo Alto, CA 94304 (US)
(21) Appl. No.: 10/040,774
(22) Filed: Dec. 28, 2001
Publication Classification
(51) Int. CI.7 G06F 9/45
(52) U.S. CI 717 154
Adata-type checker dynamically verifies program operation. The data-type checker, while executing a specified computer program, maintains a shadow array that has entries corresponding to respective memory locations used by the specified computer program. Each entry of the shadow array indicates a data type of the corresponding respective memory location. While executing the specified computer program, the data-type checker executes each of a set of instructions of the computer program. For the execution of each instruction in a subset of the set of instructions of the computer program, the data-type checker determines whether execution of the instruction is inconsistent with an entry of the shadow array and, if so, generates a report. The data-type checker then executes the instruction, and updates the shadow array in accordance with execution of the instruction.
