Mining Operational Preconditions. Andrzej Wasylkowski Andreas Zeller Saarland University

Transcription

1 Mining Operational Preconditions Andrzej Wasylkowski Andreas Zeller Saarland University

2

3 @interface A {} bug.aj aspect Test { int var* : int var* interface Subject {} } public int Subject.vara; public int Subject.varb; class X implements Test.Subject {}

4

5

6 ajc Stack Trace java.util.nosuchelementexception at java.util.abstractlist$itr.next(abstractlist.java:427) at org.aspectj.weaver.bcel.bcelclassweaver.weaveatfieldrepeatedly (BcelClassWeaver.java:1016)

7 ajc Stack Trace java.util.nosuchelementexception at java.util.abstractlist$itr.next(abstractlist.java:427) at org.aspectj.weaver.bcel.bcelclassweaver.weaveatfieldrepeatedly (BcelClassWeaver.java:1016)

8 weaveatfieldrepeatedly for (Iterator iter = itdfields.iterator(); iter.hasnext();) {... for (Iterator iter2 = worthretrying.iterator(); iter.hasnext();) {... } }

9 weaveatfieldrepeatedly for (Iterator iter = itdfields.iterator(); iter.hasnext();) {... for (Iterator iter2 = worthretrying.iterator(); iter.hasnext();) {... } should be iter2 }

10 weaveatfieldrepeatedly for (Iterator iter = itdfields.iterator(); iter.hasnext();) {... for (Iterator iter2 = worthretrying.iterator(); iter.hasnext();) {... } should be iter2 } Invalid iterator usage: hasnext() should precede next()

11 Preconditions

12 Preconditions Invoking next() with no next element violates a precondition

13 Preconditions Invoking next() with no next element violates a precondition Traditional preconditions are axiomatic describing the state of the system

14 Preconditions Invoking next() with no next element violates a precondition Traditional preconditions are axiomatic describing the state of the system How do we reach this state?

15 Preconditions

16 Preconditions close(int fildes)

17 Preconditions close(int fildes) Axiomatic: fildes is a valid file descriptor

18 Preconditions close(int fildes) Axiomatic: fildes is a valid file descriptor Operational: fildes stems from a call to open() with read() and write() calls in between

19 Preconditions close(int fildes) Axiomatic: fildes is a valid file descriptor Operational: fildes stems from a call to open() with read() and write() calls in between Can we check operational preconditions?

20 OP-Miner

21 Program OP-Miner

22 OP-Miner Usage Models Program iter.hasnext () iter.next ()

23 OP-Miner Usage Models Temporal Properties Program iter.hasnext () iter.next () hasnext next hasnext hasnext next hasnext next next

24 OP-Miner Usage Models Temporal Properties Program iter.hasnext () iter.next () hasnext next hasnext hasnext next hasnext next next Patterns hasnext next hasnext hasnext

25 OP-Miner Usage Models Temporal Properties Program iter.hasnext () iter.next () hasnext next hasnext hasnext next hasnext next next Anomalies Patterns hasnext next hasnext hasnext hasnext next hasnext hasnext hasnext next hasnext hasnext

26 OP-Miner Usage Models Temporal Properties Program iter.hasnext () iter.next () hasnext next hasnext hasnext next hasnext next next Anomalies Patterns hasnext next hasnext hasnext hasnext next hasnext hasnext hasnext next hasnext hasnext

27 Method Models public Stack createstack () { Random r = new Random (); int n = r.nextint (); Stack s = new Stack (); int i = 0; while (i < n) { s.push (rand (r)); i++; } s.push (-1); return s; }

28 Method Models public Stack createstack () { Random r = new Random (); int n = r.nextint (); Stack s = new Stack (); int i = 0; while (i < n) { s.push (rand (r)); i++; } s.push (-1); return s; }

29 Method Models public Stack createstack () { Random r = new Random (); int n = r.nextint (); Stack s = new Stack (); int i = 0; while (i < n) { s.push (rand (r)); i++; } s.push (-1); return s; } Random r = new Random ();

30 Method Models public Stack createstack () { Random r = new Random (); int n = r.nextint (); Stack s = new Stack (); int i = 0; while (i < n) { s.push (rand (r)); i++; } s.push (-1); return s; } Random r = new Random (); int n = r.nextint (); Stack s = new Stack (); int i = 0;

31 Method Models public Stack createstack () { Random r = new Random (); int n = r.nextint (); Stack s = new Stack (); int i = 0; while (i < n) { s.push (rand (r)); i++; } s.push (-1); return s; } Random r = new Random (); int n = r.nextint (); Stack s = new Stack (); int i = 0; i < n i++; s.push (rand (r));

32 Method Models public Stack createstack () { Random r = new Random (); int n = r.nextint (); Stack s = new Stack (); int i = 0; while (i < n) { s.push (rand (r)); i++; } s.push (-1); i < n return s; } s.push (-1); Random r = new Random (); int n = r.nextint (); Stack s = new Stack (); int i = 0; i < n i++; s.push (rand (r));

33 Method Models public Stack createstack () { Random r = new Random (); int n = r.nextint (); Stack s = new Stack (); int i = 0; while (i < n) { s.push (rand (r)); i++; } s.push (-1); i < n return s; } s.push (-1); Random r = new Random (); int n = r.nextint (); Stack s = new Stack (); int i = 0; i < n i++; s.push (rand (r));

34 Usage Models Random r = new Random (); int n = r.nextint (); Stack s = new Stack (); int i = 0; i < n s.push (-1); i < n s.push (rand (r)); i++;

35 Usage Models Stack s = new Stack (); s.push (-1); s.push (rand (r));

36 Usage Models s.<init>() s.push (_) s.push (_)

37 Usage Models Random r = new Random (); int n = r.nextint (); Stack s = new Stack (); int i = 0; i < n s.push (-1); i < n s.push (rand (r)); i++;

38 Usage Models Random r = new Random (); int n = r.nextint (); s.push (rand (r));

39 Usage Models r.<init> () r.nextint () Utils.rand (r)

40 JPanel.add() panel.<init> () panel.<init> (...) panel.setlayout (...) panel.add (...,...) panel.add (...,...)

41 ASTNode.reapPropertyList() list.<init> ASTNode.createPropertyList (..., list) ASTNode.addProperty (..., list) ASTNode.reapPropertyList (list)

42 Resource.getFlags() resource.getresourceinfo (...,...) resource.getflags (...)

43 OP-Miner Usage Models Temporal Properties Program iter.hasnext () iter.next () hasnext next hasnext hasnext next hasnext next next Anomalies Patterns hasnext next hasnext hasnext hasnext next hasnext hasnext hasnext next hasnext hasnext

44 OP-Miner Usage Models Temporal Properties Program iter.hasnext () iter.next () hasnext next hasnext hasnext next hasnext next next Anomalies Patterns hasnext next hasnext hasnext hasnext next hasnext hasnext hasnext next hasnext hasnext

45 Methods vs. Properties Temporal Properties start stop lock unlock eof close Methods

46 Methods vs. Properties Temporal Properties start stop lock unlock eof close get() Methods

47 Methods vs. Properties Temporal Properties start stop lock unlock eof close get() Methods open()

48 Methods vs. Properties Temporal Properties start stop lock unlock eof close get() Methods open() hello()

49 Methods vs. Properties Temporal Properties start stop lock unlock eof close get() Methods open() hello() parse()

50 Methods vs. Properties Temporal Properties start stop lock unlock eof close get() Methods open() hello() parse()

51 Methods vs. Properties Temporal Properties start stop lock unlock eof close get() Methods open() hello() parse()

52 Methods vs. Properties Temporal Properties start stop lock unlock eof close Pattern get() Methods open() hello() parse()

53 Methods vs. Properties Temporal Properties start stop lock unlock eof close Pattern get() Methods open() hello() parse() Support

54 Discovering Anomalies Temporal Properties start stop lock unlock eof close get() Methods open() hello() parse()

55 Discovering Anomalies Temporal Properties start stop lock unlock eof close get() Methods open() hello() parse()

56 Discovering Anomalies Temporal Properties start stop lock unlock eof close get() Methods open() hello() parse()

57 Discovering Anomalies Temporal Properties start stop lock unlock eof close get() Methods open() hello() parse()

58 Discovering Anomalies Temporal Properties start stop lock unlock eof close get() Methods open() hello() parse()

59 Discovering Anomalies Temporal Properties start stop lock unlock eof close get() Methods open() hello() parse()

60 Case Study: AspectJ

61 Case Study: AspectJ 2,954 classes

62 Case Study: AspectJ 2,954 classes 36,045 methods

63 Case Study: AspectJ 2,954 classes 36,045 methods 1,154 methods with OP support 20

64 Case Study: AspectJ 2,954 classes 36,045 methods 1,154 methods with OP support violations found in 8 minutes

65 Case Study: AspectJ 2,954 classes 36,045 methods 1,154 methods with OP support violations found in 8 minutes Examined every single one

66 A Defect for (Iterator iter = itdfields.iterator(); iter.hasnext();) {... for (Iterator iter2 = worthretrying.iterator(); iter.hasnext();) {... } }

67 A Defect for (Iterator iter = itdfields.iterator(); iter.hasnext();) {... for (Iterator iter2 = worthretrying.iterator(); iter.hasnext();) {... should be iter2 } }

68 A Defect for (Iterator iter = itdfields.iterator(); iter.hasnext();) {... for (Iterator iter2 = worthretrying.iterator(); iter.hasnext();) {... should be iter2 } }

69 Another Defect public void visitnewarray (NEWARRAY o) { byte t = o.gettypecode (); if (!((t == Constants.T_BOOLEAN) (t == Constants.T_CHAR)... (t == Constants.T_LONG))) { constraintviolated (o, "(...) '+t+' (...)"); } }

70 Another Defect public void visitnewarray (NEWARRAY o) { byte t = o.gettypecode (); if (!((t == Constants.T_BOOLEAN) (t == Constants.T_CHAR)... (t == Constants.T_LONG))) { constraintviolated (o, "(...) '+t+' (...)"); } } should be double quotes

71 A False Positive Name internalnewname (String[] identifiers)... for (int i = 1; i < count; i++) { SimpleName name = new SimpleName(this); name.internalsetidentifier(identifiers[i]);... }... }

72 A False Positive Name internalnewname (String[] identifiers)... for (int i = 1; i < count; i++) { SimpleName name = new SimpleName(this); name.internalsetidentifier(identifiers[i]);... } should stay as is... }

73 A Code Smell public String getretentionpolicy () {... for (Iterator it =...; it.hasnext();) {... = it.next();... return retentionpolicy; }... }

74 A Code Smell public String getretentionpolicy () {... for (Iterator it =...; it.hasnext();) {... = it.next();... return retentionpolicy; }... should be fixed }

75 AspectJ Defects Code smells False positives

76 AspectJ Defects Code smells False positives

77 AspectJ Defects Code smells False positives

78 AspectJ Defects Code smells False positives

79 More Results # Violations Program Total Investigated # Defects # Code smells # False positives Efficiency ACT-RBOT % APACHE TOMCAT % ARGOUML % ASPECTJ % AZUREUS % COLUMBA % JEDIT % 1, %

80 Future Work

81 Future Work Procedural languages leveraging appropriate static analysis frameworks

82 Future Work Procedural languages leveraging appropriate static analysis frameworks Interprocedural analysis but does this make sense for learning usage?

83 Future Work Procedural languages leveraging appropriate static analysis frameworks Interprocedural analysis but does this make sense for learning usage? Ranking violations in particular in presence of low support

84 Future Work Procedural languages leveraging appropriate static analysis frameworks Interprocedural analysis but does this make sense for learning usage? Ranking violations in particular in presence of low support Early programmer support in terms of recommendations and documentation

85 OP-Miner

86 OP-Miner OP-Miner learns operational preconditions i.e., how to typically construct arguments

87 OP-Miner OP-Miner learns operational preconditions i.e., how to typically construct arguments Learns from normal argument usage for specific projects or across projects

88 OP-Miner OP-Miner learns operational preconditions i.e., how to typically construct arguments Learns from normal argument usage for specific projects or across projects Fully automatic

89 OP-Miner OP-Miner learns operational preconditions i.e., how to typically construct arguments Learns from normal argument usage for specific projects or across projects Fully automatic Found dozens of verified defects