Compaq Computer Corporation, Inc.

Cormac A Flanagan

Michael Burrows

Mark David Lillibridge

Raymond Paul Stata

K Rustan M Leino

James Benjamin Saxe

Andrew B Bernard

The disclosed program checker checks whether a program internally tests for error codes that may be returned by procedures used by the program. The program being tested is executed. Each time that a subroutine in the program is about to perform a subroutine or procedure return operation, a program interpreter is invoked. The program interpreter simulates continued execution of the program once for a good return value and once for each error condition return value that is listed in an error condition table entry for the subroutine in which the return operation is being performed. For each simulation of the program, the program interpreter determines the execution path of the program and then compares the execution path for each error condition return value with the execution path for the good return value. If the execution path for any error condition return value is the same as the execution path for a good return value, an error report is generated to indicate that the corresponding error condition return value is not checked by the program.

System and method for dynamically detecting unchecked error condition values in computer programs

When a source program containing annotations is processed by a user-selected tool, the annotations in the source program are detected by a lexer and passed to an annotation processor corresponding to the selected tool. The system contains a number of annotation processors and a number of program processing tools, and the annotation processor to which the annotations are passed is selected based upon the user-selected tool. The selected annotation processor converts annotations compatible with the user-selected tool into annotation tokens and returns the annotation tokens to the lexer. The lexer generates tokens based upon the programming-language statements in the source program, and passes both the tokens and annotation tokens to a parser. The parser, in turn, assembles the tokens and annotation tokens into an abstract syntax tree, which is then passed to the user-selected tool for further processing.

System and method for lexing and parsing program annotations

A race condition detection system and method statically detects potential race conditions in a multi-threaded computer program. The race condition detector builds a synchronization graph representing at least a subset of a computer program's method declarations, field declarations, and synchronization statements. Edges are constructed between the nodes representing execution paths in the computer program. Each node is associated with a set of lock designations that correspond to all locks that are consistently held along all executions paths in the computer program to the respective node. The race condition detector analyzes this information to determine whether accesses to object data fields are consistently protected by an appropriate lock. An object data field access that is not protected by an appropriate lock indicates a potential race condition. At least a subset of indicated potential race conditions are reported.

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Sunnyvale, CA, United States of America

Cormac A Flanagan