Method for analyzing and presenting test execution flows of programs

• US 5,933,640 A
• Filed: 02/26/1997
• Issued: 08/03/1999
• Est. Priority Date: 02/26/1997
• Status: Expired due to Term

• Current Assignee: Hewlett Packard Enterprise Development LP (Hewlett-Packard Enterprise Company)
• Original Assignee: Digital Equipment Corporation (HP Inc.)
• Inventors: Dion, Jeremy
• Primary Examiner(s): Hafiz, Tariq R.
• Assistant Examiner(s): CORCORAN, PETER JOSEPH
• Application Number:
  US08/806,591
• Time in Patent Office: 888 Days
• Field of Search: 395/704, 395/705, 395/707, 395/708, 395/500, 395/183.11, 395/183.13, 395/183.14
• US Class Current: 717/132
• CPC Class Codes: G06F 11/3676 for coverage analysis
• CPC Class Codes: G06F 8/433 Dependency analysis; Data or control flow analysis

Abstract

A computer implemented method analyzes an execution of a program. The method partitions the program into program components such as basic blocks and procedures. A source or executable representation of the program is instrumented to collect test coverage data. In addition, a flow graph representing the program components is generated. The program is then executed to collect test coverage data. Using the test coverage data and the flow graph, the program is partitioned into executed and unexecuted components. The number of instructions in each unexecuted program component is counted. Thus, a list of the unexecuted program components can be presented according to a decreasing order of the number of unexecuted instructions in the unexecuted program components.

Claims

1. A computer implemented method for analyzing test coverage data of a program in a computer, comprising the steps of:

generating a flowgraph representing program components of the program and possible execution flows through the program components;

collecting test coverage data while executing the program;

determining executed and unexecuted program components on the flowgraph using the collected test coverage data; and

presenting a list of unexecuted program components according to a decreasing order of a number of unexecuted instructions reachable from each unexecuted program component.

2. The method of claim 1 wherein the step of presenting further comprises the steps of:

selecting unexecuted destination points from among the unexecuted program components; and

counting the number of unexecuted instructions reachable from each of the selected unexecuted destination points.

3. The method of claim 2 further comprising:

selecting first unexecuted destination points that are targets of executed flow control instructions.

4. The method of claim 2 further comprising:

selecting second unexecuted destination points that are targets of indirect procedure calls.

5. The method of claim 2 further comprising:

selecting third unexecuted destination points that are unreachable by any program component.

6. The method of claim 1 further comprising:

instrumenting a source code representation of the program.

7. The method of claim 1 further comprising:

instrumenting a machine executable code representation the program.

8. The method of claim 1 further comprising:

generating a complete graph of the program.

9. The method of claim 1 further comprising:

generating a partial graph of the program.

10. The method of claim 1 further comprising:

identifying flow control instructions in the program which are decision points, the flow control instructions that can dynamically alter the execution flow to multiple destination points;

adding calls to the program at each possible destination point, the calls to divert the execution flow to monitoring routine for recording test coverage data in a memory of the computer.

11. The method of claim 10 further comprising:

linking the monitoring routine to the program when the program is loaded for execution.

12. The method of claim 1 wherein the graph includes one node for each program component to be represented, and edges of the graph indicate possible execution flows between directly called program components.

13. The method of claim 12 further comprising:

beginning at a particular unexecuted destination point, traversing all edges of the graph linking unexecuted program components while counting until another executed program component is reached.

14. The method of claim 12 further comprising:

coloring nodes of the graph to indicate the unexecuted program components.

15. The method of claim 1 wherein the program components are basic blocks and procedures.