2. escj 28

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4. Static checkers

5. Compaq Confidential - Need to Know Required Type checking vs. extended static checking  Are annotations needed?  How many annotations per variable/method?  Escape hatch for when annotation gets too complicated? Type checkingE.s.c. yes 10 -- many dynamic castsassume, nowarn

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7. Annotation assistant

8. Compaq Confidential - Need to Know Required Annotation assistant

9. Compaq Confidential - Need to Know Required Annotation assistant

10. Compaq Confidential - Need to Know Required Annotation assistant

11. Compaq Confidential - Need to Know Required Annotation assistant

12. Compaq Confidential - Need to Know Required Annotation assistant

13. Compaq Confidential - Need to Know Required -suggest switch  Use simple (possibly bogus) heuristics Cup.java:18: Warning: possible null dereference (Null) x = o.f; ^

14. Compaq Confidential - Need to Know Required -suggest switch  Use simple (possibly bogus) heuristics Cup.java:18: Warning: possible null dereference (Null) x = o.f; ^ Suggestion: perhaps declare ‘o’ as ‘non_null’

15. Compaq Confidential - Need to Know Required Annotation wizard design repeat call ESC/Java -suggest on sources; distill output into update instructions; act on update instructions until quiescence

16. Compaq Confidential - Need to Know Required Update instructions insert “/*@ … */” at 6,12 in Cup.java else “/*@ nowarn … */” at 28,17 in Client.java

17. Compaq Confidential - Need to Know Required Pachyclient case study  ~11,000 lines of code  ~650 methods  43 files  110 minutes (2.5 minutes to compile)  13 iterations  971 annotations

18. Compaq Confidential - Need to Know Required How were the 110 minutes spent? Iteration Warnings Minutes 039214 125612 213610 3789 4428 5248 6207 7117 867 937 1027 1117 1207 -------- -------- -------- TOTAL:13971110

19. Compaq Confidential - Need to Know Required What became of the 971 warnings?  non_null instance fields304 instance fields304 parameters219 parameters219 local variables108(later: 27) local variables108(later: 27) static fields5 static fields5  postcondition RES != null49  requires 0 <= x2  ensures 0 <= RES2  invariant 0 <= x1  no heuristic null related47(29 for ‘null’) null related47(29 for ‘null’) negative related16 negative related16  suggestion in different file169  annotation inserter gives up49

20. Compaq Confidential - Need to Know Required Did the wizard help?  null and negative checking only warnings on unannotated code:938 warnings on unannotated code:938 warnings on wizard-annotated code:274 warnings on wizard-annotated code:274  all checking (but heuristics only for null and negative) warnings on unannotated code:>1100 warnings on unannotated code:>1100 warnings on wizard-annotated code:488 warnings on wizard-annotated code:488

21. Compaq Confidential - Need to Know Required What kinds of warnings remain?  Null121(83)  NonNull131(83)  NonNullInit5  IndexNegative15  NegSize2(1)  Cast111  Pre48  IndexTooBig32  Post14  ZeroDiv7  Invariant2 (Numbers in parentheses indicate how many of the warnings have annotation suggestions in libraries.)

22. Compaq Confidential - Need to Know Required Annotating libraries Suggestion [359,52]: perhaps declare method 'getText' in /tmp_mnt/bill/r/dlusers14/sanjay/srcjava1.1/files/../files/jdk-114.zip: java/awt/TextComponent.class with 'ensures RES != null;'

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26. Compaq Research Harder questions