codeql/python/ql/src/Numerics/Pythagorean.ql at codeql-cli/v2.15.3 · github/codeql · GitHub

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/**

* @name Pythagorean calculation with sub-optimal numerics

* @description Calculating the length of the hypotenuse using the standard formula may lead to overflow.

* @kind problem

* @tags accuracy

* @problem.severity warning

* @sub-severity low

* @precision medium

* @id py/pythagorean

import python

import semmle.python.dataflow.new.DataFlow

import semmle.python.ApiGraphs

DataFlow::ExprNode squareOp() {

exists(BinaryExpr e | e = result.asExpr() |

e.getOp() instanceof Pow and e.getRight().(IntegerLiteral).getN() = "2"

)

}

DataFlow::ExprNode squareMul() {

exists(BinaryExpr e | e = result.asExpr() |

e.getOp() instanceof Mult and e.getRight().(Name).getId() = e.getLeft().(Name).getId()

)

}

DataFlow::ExprNode square() { result in [squareOp(), squareMul()] }

from DataFlow::CallCfgNode c, BinaryExpr s, DataFlow::ExprNode left, DataFlow::ExprNode right

where

c = API::moduleImport("math").getMember("sqrt").getACall() and

c.getArg(0).asExpr() = s and

s.getOp() instanceof Add and

left.asExpr() = s.getLeft() and

right.asExpr() = s.getRight() and

left.getALocalSource() = square() and

right.getALocalSource() = square()

select c, "Pythagorean calculation with sub-optimal numerics."

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