CodeQL documentation

Unclear comparison precedence

ID: cpp/comparison-precedence
Kind: problem
Severity: warning
Precision: very-high
Tags:
   - maintainability
   - readability
Query suites:
   - cpp-security-and-quality.qls

Click to see the query in the CodeQL repository

This rule finds comparison expressions that use 2 or more comparison operators and are not completely paranthesized. It is best to fully parenthesize complex comparison expressions to explicitly define the order of the comparison operators.

Recommendation

Fully parenthesize complex comparison expressions to avoid confusion.

Example

void h() {
	int a, b, c;

	a < b != c; //parenthesize to explicitly define order of operators
	(a < b) < c; //correct: parenthesized to specify order
}