CWE-1071¶
Empty Code Block. [Bad-Coding-Practices, Improper-Adherence-To-Coding-Standards]
Required inputs: IR
Empty code blocks can occur in the bodies of conditionals, function or method definitions, exception handlers, etc. While an empty code block might be intentional, it might also indicate incomplete implementation, accidental code deletion, unexpected macro expansion, etc. For some programming languages and constructs, an empty block might be allowed by the syntax, but the lack of any behavior within the block might violate a convention or API in such a way that it is an error.
Demonstrative Examples
Example 1
In the following Java example, the code catches an ArithmeticException.
Example Language:Java (Unsupported language for documentation only)
public class Main {
public static void main(String[] args) {
int a = 1;
int b = 0;
int c = 0;
try {
c = a / b;
} catch(ArithmeticException ae) {
}
}
}
Since the exception block is empty, no action is taken.
In the code below the exception has been logged and the bad execution has been handled in the desired way allowing the program to continue in an expected way.
Example Language:Java (Unsupported language for documentation only)
public class Main {
public static void main(String[] args) {
int a = 1;
int b = 0;
int c = 0;
try {
c = a / b;
} catch(ArithmeticException ae) {
log.error("Divided by zero detected, setting to -1.");
c = -1;
}
}
}
Example 2
The following code attempts to synchronize on an object, but does not execute anything in the synchronized block. This does not actually accomplish anything and may be a sign that a programmer is wrestling with synchronization but has not yet achieved the result they intend.
Example Language:Java (Unsupported language for documentation only)
synchronized(this) { }
Instead, in a correct usage, the synchronized statement should contain procedures that access or modify data that is exposed to multiple threads. For example, consider a scenario in which several threads are accessing student records at the same time. The method which sets the student ID to a new value will need to make sure that nobody else is accessing this data at the same time and will require synchronization.
public void setID(int ID){
synchronized(this){
this.ID = ID;
}
}Excerpts from CWE [https://cwe.mitre.org], Copyright (C) 2006-2026, the MITRE Corporation. See section 9.4. "3rd-Party Licenses" in the documentation for full details.Possible Messages
Key |
Text |
Severity |
Disabled |
|---|---|---|---|
empty_block |
The source code contains a block that does not contain any code, i.e., the block is empty. |
None |
False |
Options¶
This rule shares the following common options: exclude_in_macros, exclude_messages_in_system_headers, excludes, extend_exclude_to_macro_invocations, includes, justification_checker, languages, post_processing, provider, report_at, severity
The following places define options that affect this rule: Stylechecks, Analysis-GlobalOptions
allow_if_block_contains_comment¶
allow_if_block_contains_comment : bool = True