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fef08afff9
Moves the existing points-to predicates to the newly added class `ControlFlowNodeWithPointsTo` which resides in the `LegacyPointsTo` module. (Existing code that uses these predicates should import this module, and references to `ControlFlowNode` should be changed to `ControlFlowNodeWithPointsTo`.) Also updates all existing points-to based code to do just this.
30 lines
918 B
Plaintext
30 lines
918 B
Plaintext
/**
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* @name String concatenation in loop
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* @description Concatenating strings in loops has quadratic performance.
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* @kind problem
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* @tags efficiency
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* maintainability
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* @problem.severity recommendation
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* @sub-severity low
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* @precision low
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* @id py/string-concatenation-in-loop
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*/
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import python
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private import LegacyPointsTo
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predicate string_concat_in_loop(BinaryExpr b) {
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b.getOp() instanceof Add and
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exists(SsaVariable d, SsaVariable u, BinaryExprNode add |
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add.getNode() = b and d = u.getAnUltimateDefinition()
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d.getDefinition().(DefinitionNode).getValue() = add and
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u.getAUse() = add.getAnOperand() and
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add.getAnOperand().(ControlFlowNodeWithPointsTo).pointsTo().getClass() = ClassValue::str()
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)
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}
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from BinaryExpr b, Stmt s
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where string_concat_in_loop(b) and s.getASubExpression() = b
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select s, "String concatenation in a loop is quadratic in the number of iterations."
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