The software contains dead code, which can never be executed.
Extended Description
Dead code is source code that can never be executed in a running program. The surrounding code makes it impossible for a section of code to ever be executed.
Time of Introduction
Implementation
Common Consequences
Scope
Effect
Other
Technical Impact: Quality degradation
Dead code that results from code that can never be executed is an
indication of problems with the source code that needs to be fixed and
is an indication of poor quality.
Demonstrative Examples
Example 1
The condition for the second if statement is impossible to satisfy.
It requires that the variables be non-null, while on the only path where s
can be assigned a non-null value there is a return statement.
(Bad Code)
Example
Language: C++
String s = null;
if (b) {
s = "Yes";
return;
}
if (s != null) {
Dead();
}
Example 2
In the following class, two private methods call each other, but
since neither one is ever invoked from anywhere else, they are both dead
code.
(Bad Code)
Example
Language: Java
public class DoubleDead {
private void doTweedledee() {
doTweedledumb();
}
private void doTweedledumb() {
doTweedledee();
}
public static void main(String[] args) {
System.out.println("running DoubleDead");
}
}
(In this case it is a good thing that the methods are dead: invoking
either one would cause an infinite loop.)
Example 3
The field named glue is not used in the following class. The author
of the class has accidentally put quotes around the field name, transforming
it into a string constant.
(Bad Code)
Example
Language: Java
public class Dead {
String glue;
public String getGlue() {
return "glue";
}
}
Potential Mitigations
Phase: Implementation
Remove dead code before deploying the application.
Description
