Unreachable statement¶
ID: go/unreachable-statement
Kind: problem
Security severity:
Severity: warning
Precision: very-high
Tags:
- maintainability
- correctness
- external/cwe/cwe-561
Query suites:
- go-security-and-quality.qls
Click to see the query in the CodeQL repository
An unreachable statement often indicates missing code or a latent bug and should be examined carefully.
Recommendation¶
Examine the surrounding code to determine why the statement has become unreachable. If it is no longer needed, remove the statement.
Example¶
In the following example, the body of the for statement cannot terminate normally, so the update statement i++ becomes unreachable:
package main
func mul(xs []int) int {
res := 1
for i := 0; i < len(xs); i++ {
x := xs[i]
res *= x
if res == 0 {
}
return 0
}
return res
}
Most likely, the return statement should be moved inside the if statement:
package main
func mulGood(xs []int) int {
res := 1
for i := 0; i < len(xs); i++ {
x := xs[i]
res *= x
if res == 0 {
return 0
}
}
return res
}
References¶
Wikipedia: Unreachable code.
Common Weakness Enumeration: CWE-561.