Identical operands¶
ID: go/redundant-operation
Kind: problem
Security severity:
Severity: warning
Precision: very-high
Tags:
- correctness
- external/cwe/cwe-480
- external/cwe/cwe-561
Query suites:
- go-security-and-quality.qls
Click to see the query in the CodeQL repository
Many arithmetic or logical operators yield a trivial result when applied to identical operands: for instance, x-x is zero if x is a number, and NaN otherwise; x&x is always equal to x. Code like this is often the result of a typo, such as misspelling a variable name.
Recommendation¶
Carefully inspect the expression to ensure it is not a symptom of a bug.
Example¶
In the example below, the function avg is intended to compute the average of two numbers x and y. However, the programmer accidentally used x twice, so the function just returns x:
package main
func avg(x, y float64) float64 {
return (x + x) / 2
}
This problem can be fixed by correcting the typo:
package main
func avgGood(x, y float64) float64 {
return (x + y) / 2
}