howardjones/network-weathermap

Unused parameters are misleading. Whatever the value passed to such parameters is, the behavior will be the same.

Noncompliant Code Example

function doSomething($a, $b) { // "$a" is unused
  return compute($b);
}

Compliant Solution

function doSomething($b) {
  return compute($b);
}

Exceptions

Functions in classes that override a class or implement interfaces are ignored.

class C extends B {

  function doSomething($a, $b) {     // no issue reported on $b
    compute($a);
  }

}

See

• MISRA C++:2008, 0-1-11 - There shall be no unused parameters (named or unnamed) in nonvirtual functions.
• MISRA C:2012, 2.7 - There should be no unused parameters in functions
• CERT, MSC12-C. - Detect and remove code that has no effect or is never executed
• CERT, MSC12-CPP. - Detect and remove code that has no effect

Duplicated string literals make the process of refactoring error-prone, since you must be sure to update all occurrences.

On the other hand, constants can be referenced from many places, but only need to be updated in a single place.

Noncompliant Code Example

With the default threshold of 3:

function run() {
  prepare('action1');                              // Non-Compliant - 'action1' is duplicated 3 times
  execute('action1');
  release('action1');
}

Compliant Solution

ACTION_1 = 'action1';

function run() {
  prepare(ACTION_1);
  execute(ACTION_1);
  release(ACTION_1);
}

Exceptions

To prevent generating some false-positives, literals having less than 5 characters are excluded.

Programmers should not comment out code as it bloats programs and reduces readability.

Unused code should be deleted and can be retrieved from source control history if required.

See

• MISRA C:2004, 2.4 - Sections of code should not be "commented out".
• MISRA C++:2008, 2-7-2 - Sections of code shall not be "commented out" using C-style comments.
• MISRA C++:2008, 2-7-3 - Sections of code should not be "commented out" using C++ comments.
• MISRA C:2012, Dir. 4.4 - Sections of code should not be "commented out"

Duplicated string literals make the process of refactoring error-prone, since you must be sure to update all occurrences.

On the other hand, constants can be referenced from many places, but only need to be updated in a single place.

Noncompliant Code Example

With the default threshold of 3:

function run() {
  prepare('action1');                              // Non-Compliant - 'action1' is duplicated 3 times
  execute('action1');
  release('action1');
}

Compliant Solution

ACTION_1 = 'action1';

function run() {
  prepare(ACTION_1);
  execute(ACTION_1);
  release(ACTION_1);
}

Exceptions

To prevent generating some false-positives, literals having less than 5 characters are excluded.

Programmers should not comment out code as it bloats programs and reduces readability.

Unused code should be deleted and can be retrieved from source control history if required.

See

• MISRA C:2004, 2.4 - Sections of code should not be "commented out".
• MISRA C++:2008, 2-7-2 - Sections of code shall not be "commented out" using C-style comments.
• MISRA C++:2008, 2-7-3 - Sections of code should not be "commented out" using C++ comments.
• MISRA C:2012, Dir. 4.4 - Sections of code should not be "commented out"

Unused parameters are misleading. Whatever the value passed to such parameters is, the behavior will be the same.

Noncompliant Code Example

function doSomething($a, $b) { // "$a" is unused
  return compute($b);
}

Compliant Solution

function doSomething($b) {
  return compute($b);
}

Exceptions

Functions in classes that override a class or implement interfaces are ignored.

class C extends B {

  function doSomething($a, $b) {     // no issue reported on $b
    compute($a);
  }

}

See

• MISRA C++:2008, 0-1-11 - There shall be no unused parameters (named or unnamed) in nonvirtual functions.
• MISRA C:2012, 2.7 - There should be no unused parameters in functions
• CERT, MSC12-C. - Detect and remove code that has no effect or is never executed
• CERT, MSC12-CPP. - Detect and remove code that has no effect

Duplicated string literals make the process of refactoring error-prone, since you must be sure to update all occurrences.

On the other hand, constants can be referenced from many places, but only need to be updated in a single place.

Noncompliant Code Example

With the default threshold of 3:

function run() {
  prepare('action1');                              // Non-Compliant - 'action1' is duplicated 3 times
  execute('action1');
  release('action1');
}

Compliant Solution

ACTION_1 = 'action1';

function run() {
  prepare(ACTION_1);
  execute(ACTION_1);
  release(ACTION_1);
}

Exceptions

To prevent generating some false-positives, literals having less than 5 characters are excluded.

Duplicated string literals make the process of refactoring error-prone, since you must be sure to update all occurrences.

On the other hand, constants can be referenced from many places, but only need to be updated in a single place.

Noncompliant Code Example

With the default threshold of 3:

function run() {
  prepare('action1');                              // Non-Compliant - 'action1' is duplicated 3 times
  execute('action1');
  release('action1');
}

Compliant Solution

ACTION_1 = 'action1';

function run() {
  prepare(ACTION_1);
  execute(ACTION_1);
  release(ACTION_1);
}

Exceptions

To prevent generating some false-positives, literals having less than 5 characters are excluded.

Duplicated string literals make the process of refactoring error-prone, since you must be sure to update all occurrences.

On the other hand, constants can be referenced from many places, but only need to be updated in a single place.

Noncompliant Code Example

With the default threshold of 3:

function run() {
  prepare('action1');                              // Non-Compliant - 'action1' is duplicated 3 times
  execute('action1');
  release('action1');
}

Compliant Solution

ACTION_1 = 'action1';

function run() {
  prepare(ACTION_1);
  execute(ACTION_1);
  release(ACTION_1);
}

Exceptions

To prevent generating some false-positives, literals having less than 5 characters are excluded.

Duplicated string literals make the process of refactoring error-prone, since you must be sure to update all occurrences.

On the other hand, constants can be referenced from many places, but only need to be updated in a single place.

Noncompliant Code Example

With the default threshold of 3:

function run() {
  prepare('action1');                              // Non-Compliant - 'action1' is duplicated 3 times
  execute('action1');
  release('action1');
}

Compliant Solution

ACTION_1 = 'action1';

function run() {
  prepare(ACTION_1);
  execute(ACTION_1);
  release(ACTION_1);
}

Exceptions

To prevent generating some false-positives, literals having less than 5 characters are excluded.

Duplicated string literals make the process of refactoring error-prone, since you must be sure to update all occurrences.

On the other hand, constants can be referenced from many places, but only need to be updated in a single place.

Noncompliant Code Example

With the default threshold of 3:

function run() {
  prepare('action1');                              // Non-Compliant - 'action1' is duplicated 3 times
  execute('action1');
  release('action1');
}

Compliant Solution

ACTION_1 = 'action1';

function run() {
  prepare(ACTION_1);
  execute(ACTION_1);
  release(ACTION_1);
}

Exceptions

To prevent generating some false-positives, literals having less than 5 characters are excluded.

Duplicated string literals make the process of refactoring error-prone, since you must be sure to update all occurrences.

On the other hand, constants can be referenced from many places, but only need to be updated in a single place.

Noncompliant Code Example

With the default threshold of 3:

function run() {
  prepare('action1');                              // Non-Compliant - 'action1' is duplicated 3 times
  execute('action1');
  release('action1');
}

Compliant Solution

ACTION_1 = 'action1';

function run() {
  prepare(ACTION_1);
  execute(ACTION_1);
  release(ACTION_1);
}

Exceptions

To prevent generating some false-positives, literals having less than 5 characters are excluded.

Duplicated string literals make the process of refactoring error-prone, since you must be sure to update all occurrences.

On the other hand, constants can be referenced from many places, but only need to be updated in a single place.

Noncompliant Code Example

With the default threshold of 3:

function run() {
  prepare('action1');                              // Non-Compliant - 'action1' is duplicated 3 times
  execute('action1');
  release('action1');
}

Compliant Solution

ACTION_1 = 'action1';

function run() {
  prepare(ACTION_1);
  execute(ACTION_1);
  release(ACTION_1);
}

Exceptions

To prevent generating some false-positives, literals having less than 5 characters are excluded.

private methods that are never executed are dead code: unnecessary, inoperative code that should be removed. Cleaning out dead code decreases the size of the maintained codebase, making it easier to understand the program and preventing bugs from being introduced.

Noncompliant Code Example

public class Foo
{
  private function Foo() {}   // Compliant, private empty constructor intentionally used to prevent any direct instantiation of a class.

  public static function doSomething()
  {
    $foo = new Foo();
    ...
  }

  private function unusedPrivateFunction() {  // Noncompliant
  }
}

Compliant Solution

public class Foo
{
  private function Foo(){}   // Compliant, private empty constructor intentionally used to prevent any direct instantiation of a class.

  public static function doSomething()
  {
    $foo = new Foo();
  }
}

See

• CERT, MSC07-CPP. - Detect and remove dead code

Duplicated string literals make the process of refactoring error-prone, since you must be sure to update all occurrences.

On the other hand, constants can be referenced from many places, but only need to be updated in a single place.

Noncompliant Code Example

With the default threshold of 3:

function run() {
  prepare('action1');                              // Non-Compliant - 'action1' is duplicated 3 times
  execute('action1');
  release('action1');
}

Compliant Solution

ACTION_1 = 'action1';

function run() {
  prepare(ACTION_1);
  execute(ACTION_1);
  release(ACTION_1);
}

Exceptions

To prevent generating some false-positives, literals having less than 5 characters are excluded.

If you throw a general exception type, such as ErrorException, RuntimeException, or Exception in a library or framework, it forces consumers to catch all exceptions, including unknown exceptions that they do not know how to handle.

Instead, either throw a subtype that already exists in the Standard PHP Library, or create your own type that derives from Exception.

Noncompliant Code Example

throw new Exception();  // Noncompliant

Compliant Solution

throw new InvalidArgumentException();
// or
throw new UnexpectedValueException();

See

• MITRE, CWE-397 - Declaration of Throws for Generic Exception
• CERT, ERR07-J. - Do not throw RuntimeException, Exception, or Throwable

private methods that are never executed are dead code: unnecessary, inoperative code that should be removed. Cleaning out dead code decreases the size of the maintained codebase, making it easier to understand the program and preventing bugs from being introduced.

Noncompliant Code Example

public class Foo
{
  private function Foo() {}   // Compliant, private empty constructor intentionally used to prevent any direct instantiation of a class.

  public static function doSomething()
  {
    $foo = new Foo();
    ...
  }

  private function unusedPrivateFunction() {  // Noncompliant
  }
}

Compliant Solution

public class Foo
{
  private function Foo(){}   // Compliant, private empty constructor intentionally used to prevent any direct instantiation of a class.

  public static function doSomething()
  {
    $foo = new Foo();
  }
}

See

• CERT, MSC07-CPP. - Detect and remove dead code

The requirement for a final case default clause is defensive programming. The clause should either take appropriate action, or contain a suitable comment as to why no action is taken. Even when the switch covers all current values of an enum, a default case should still be used because there is no guarantee that the enum won't be extended.

Noncompliant Code Example

switch ($param) {  //missing default clause
  case 0:
    do_something();
    break;
  case 1:
    do_something_else();
    break;
}

switch ($param) {
  default: // default clause should be the last one
    error();
    break;
  case 0:
    do_something();
    break;
  case 1:
    do_something_else();
    break;
}

Compliant Solution

switch ($param) {
  case 0:
    do_something();
    break;
  case 1:
    do_something_else();
    break;
  default:
    error();
    break;
}

See

• MISRA C:2004, 15.0 - The MISRA C switch syntax shall be used.
• MISRA C:2004, 15.3 - The final clause of a switch statement shall be the default clause
• MISRA C++:2008, 6-4-3 - A switch statement shall be a well-formed switch statement.
• MISRA C++:2008, 6-4-6 - The final clause of a switch statement shall be the default-clause
• MISRA C:2012, 16.1 - All switch statements shall be well-formed
• MISRA C:2012, 16.4 - Every switch statement shall have a default label
• MISRA C:2012, 16.5 - A default label shall appear as either the first or the last switch label of a switch statement
• MITRE, CWE-478 - Missing Default Case in Switch Statement
• CERT, MSC01-C. - Strive for logical completeness
• CERT, MSC01-CPP. - Strive for logical completeness

Duplicated string literals make the process of refactoring error-prone, since you must be sure to update all occurrences.

On the other hand, constants can be referenced from many places, but only need to be updated in a single place.

Noncompliant Code Example

With the default threshold of 3:

function run() {
  prepare('action1');                              // Non-Compliant - 'action1' is duplicated 3 times
  execute('action1');
  release('action1');
}

Compliant Solution

ACTION_1 = 'action1';

function run() {
  prepare(ACTION_1);
  execute(ACTION_1);
  release(ACTION_1);
}

Exceptions

To prevent generating some false-positives, literals having less than 5 characters are excluded.

Duplicated string literals make the process of refactoring error-prone, since you must be sure to update all occurrences.

On the other hand, constants can be referenced from many places, but only need to be updated in a single place.

Noncompliant Code Example

With the default threshold of 3:

function run() {
  prepare('action1');                              // Non-Compliant - 'action1' is duplicated 3 times
  execute('action1');
  release('action1');
}

Compliant Solution

ACTION_1 = 'action1';

function run() {
  prepare(ACTION_1);
  execute(ACTION_1);
  release(ACTION_1);
}

Exceptions

To prevent generating some false-positives, literals having less than 5 characters are excluded.