| 1 | Checkers(
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| 2 | [
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| 3 |
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| 4 | #@Show(false)
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| 5 | define(Elvis1,coin,"elvis1",
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| 6 | BT_TYPE_RULESET,
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| 7 | ruleset(
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| 8 | # a==null ? b : a
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| 9 | ConditionalExpression(
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| 10 | EqualityExpression($a,"==",NullLiteral()), $b, $a ) -> true
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| 11 | [ violationDiscovered(Elvis1, "elvis1", s($a,$b)) ],
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| 12 | # a!=null ? a : b
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| 13 | ConditionalExpression(
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| 14 | EqualityExpression($a,"!=",NullLiteral()), $a, $b ) -> true
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| 15 | [ violationDiscovered(Elvis1, "elvis1", s($a,$b)) ],
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| 16 | # null==a ? b: a
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| 17 | ConditionalExpression(
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| 18 | EqualityExpression(NullLiteral(),"==",$a), $b, $a) -> true
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| 19 | [ violationDiscovered(Elvis1, "elvis1", s($a,$b)) ],
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| 20 | # null!=a ? a: b
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| 21 | ConditionalExpression(
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| 22 | EqualityExpression(NullLiteral(),"!=",$a), $a, $b ) -> true
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| 23 | [ violationDiscovered(Elvis1, "elvis1", s($a,$b)) ],
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| 24 |
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| 25 | Block($x) -> false
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| 26 |
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| 27 | ),false),
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| 28 |
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| 29 |
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| 30 | #@Show(false)
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| 31 | define(NullSafe,coin,"nullsafe call of fields and methods",
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| 32 | BT_TYPE_RULESET,
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| 33 | ruleset(
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| 34 |
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| 35 | import(general, apply),
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| 36 | import(List, car),
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| 37 |
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| 38 | # we don not want write same conditions exceptions 4 times, so
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| 39 | # transform all to one form.
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| 40 | EqualityExpression($a,"!=",NullLiteral()) -> IsNotNullExpression($a),
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| 41 | EqualityExpression(NullLiteral(),"!=",$a) -> IsNotNullExpression($a),
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| 42 | EqualityExpression($a,"==",NullLiteral()) -> IsNullExpression($a),
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| 43 | EqualityExpression(NullLiteral(),"==",$a) -> IsNullExpression($a),
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| 44 |
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| 45 | # if (foo!=null) { foo.process(); }
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| 46 | IfStatement(IsNotNullExpression($foo),
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| 47 | Block([StatementExpressionStatement(StatementExpression(
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| 48 | MethodCall($foo,$m,$args)
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| 49 | ))]))
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| 50 | -> true
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| 51 | [ violationDiscovered(NullSafe, "null safe method call in statement", s($foo,$m,$args)) ],
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| 52 | # if (foo!=null) { bar=foo.process(); }
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| 53 | IfStatement(IsNotNullExpression($foo),
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| 54 | Block([StatementExpressionStatement(StatementExpression(
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| 55 | $bar,"=",MethodCall($foo,$m,$args)
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| 56 | ))]))
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| 57 | -> true
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| 58 | [ violationDiscovered(NullSafe, "null safe methd call in statement", s($foo,$m,$args)) ],
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| 59 |
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| 60 |
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| 61 | ConditionalExpression(IsNotNullExpression($a),$x,$y)->
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| 62 | ConditionalExpressionNotNull($a,$x,$y),
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| 63 | ConditionalExpression(IsNullExpression($a),$x,$y)->
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| 64 | ConditionalExpressionNotNull($a,$y,$x),
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| 65 |
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| 66 | # a!=null ? a.method() : null
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| 67 | ConditionalExpressionNotNull($a,
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| 68 | MethodCall($a,$m,$args), NullLiteral() ) -> true
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| 69 | [ violationDiscovered(NullSafe,
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| 70 | "null safe method call in condition", s($m,$args)) ],
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| 71 |
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| 72 | ConditionalExpressionNotNull($a,
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| 73 | Name([$a:$x]), NullLiteral() ) -> true
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| 74 | [ violationDiscovered(NullSafe,
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| 75 | "null safe field access in condition", s($a,$x)) ],
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| 76 |
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| 77 | ConditionalExpressionNotNull($a,
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| 78 | Field($a,$x), NullLiteral() ) -> true
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| 79 | [ violationDiscovered(NullSafe,
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| 80 | "null safe field access in condition", s($a,$x)) ],
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| 81 |
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| 82 | ConditionalExpressionNotNull($a,ArrayIndex($a,$x),NullLiteral())
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| 83 | -> true
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| 84 | [ violationDiscovered(NullSafe,
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| 85 | "null safe array access ", s($a,$x)) ],
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| 86 |
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| 87 | # now try to handle complex If expressions.
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| 88 | # interesting if-s are those, who consists only from
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| 89 | # IsNotNullExpression
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| 90 | ConditionalAndExpression(IsNotNullExpression($a),
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| 91 | IsNotNullExpression($b))
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| 92 | ->
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| 93 | ConditionalAndExpressions([$a,$b]),
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| 94 |
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| 95 | ConditionalAndExpression(IsNotNullExpression($a),
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| 96 | ConditionalAndExpressions($list))
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| 97 | -> ConditionalAndExpressions(cons($a,$list)),
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| 98 |
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| 99 | IfStatement(ConditionalAndExpressions($cn),$block)
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| 100 | -> CHECK(FindSubterm.find(car($cn),$block),$block),
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| 101 |
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| 102 | IfStatement($other,$x) -> false,
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| 103 |
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| 104 | IfStatement(ConditionalAndExpressions($cn),$block, $elsblock)
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| 105 | -> CHECK(FindSubterm.find(car($cn),$block),$block),
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| 106 |
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| 107 | IfStatement($other,$x,$y) -> false,
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| 108 |
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| 109 | CHECK(true,$block) -> true
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| 110 | [ violationDiscovered(NullSafe,
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| 111 | "multiple test for null access", $block) ],
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| 112 |
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| 113 | CHECK(false,$block) -> false,
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| 114 |
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| 115 | ## all other can be reduced.
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| 116 | Block($x) -> false,
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| 117 |
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| 118 | p($x) -> $x [ println($x) ]
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| 119 |
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| 120 | ),false)
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| 121 |
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| 122 | ]
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| 123 |
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| 124 | );
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| 125 |
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