/script/lib/PHP/CodeSniffer/Standards/Squiz/Sniffs/PHP/NonExecutableCodeSniff.php

<?php

/**
 * Squiz_Sniffs_PHP_InnerFunctionsSniff.
 *
 * PHP version 5
 *
 * @category  PHP
 * @package   PHP_CodeSniffer
 * @author    Greg Sherwood <gsherwood@squiz.net>
 * @author    Marc McIntyre <mmcintyre@squiz.net>
 * @copyright 2006 Squiz Pty Ltd (ABN 77 084 670 600)
 * @license   http://matrix.squiz.net/developer/tools/php_cs/licence BSD Licence
 * @version   CVS: $Id: NonExecutableCodeSniff.php 293565 2010-01-15 01:18:35Z squiz $
 * @link      http://pear.php.net/package/PHP_CodeSniffer
 */



/**
 * Squiz_Sniffs_PHP_NonExecutableCodeSniff.
 *
 * Warns about code that can never been executed. This happens when a function
 * returns before the code, or a break ends execution of a statement etc.
 *
 * @category  PHP
 * @package   PHP_CodeSniffer
 * @author    Greg Sherwood <gsherwood@squiz.net>
 * @author    Marc McIntyre <mmcintyre@squiz.net>
 * @copyright 2006 Squiz Pty Ltd (ABN 77 084 670 600)
 * @license   http://matrix.squiz.net/developer/tools/php_cs/licence BSD Licence
 * @version   Release: 1.2.2
 * @link      http://pear.php.net/package/PHP_CodeSniffer
 */

class Squiz_Sniffs_PHP_NonExecutableCodeSniff implements PHP_CodeSniffer_Sniff

{



    /**
     * Returns an array of tokens this test wants to listen for.
     *
     * @return array
     */

    public function register()

    {

        return array(T_BREAK, T_CONTINUE, T_RETURN, T_EXIT);

    

    } //end register()


    

    /**
     * Processes this test, when one of its tokens is encountered.
     *
     * @param PHP_CodeSniffer_File $phpcsFile The file being scanned.
     * @param int                  $stackPtr  The position of the current token in
     * the stack passed in $tokens.
     *
     * @return void
     */

    public function process(PHP_CodeSniffer_File $phpcsFile, $stackPtr)

    {

        $tokens = $phpcsFile->getTokens();

        

        if ($tokens[$stackPtr]['code'] === T_RETURN)

        {

            $next = $phpcsFile->findNext(T_WHITESPACE, ($stackPtr + 1), null, true);

            if ($tokens[$next]['code'] === T_SEMICOLON)

            {

                $next = $phpcsFile->findNext(T_WHITESPACE, ($next + 1), null, true);

                if ($tokens[$next]['code'] === T_CLOSE_CURLY_BRACKET)

                {

                    // If this is the closing brace of a function
                    // then this return statement doesn't return anything
                    // and is not required anyway.
                    $owner = $tokens[$next]['scope_condition'];

                    if ($tokens[$owner]['code'] === T_FUNCTION)

                    {

                        $warning = 'Empty return statement not required here';

                        $phpcsFile->addWarning($warning, $stackPtr, 'ReturnNotRequired');

                        return;

                    }

                }

            }

        }

        

        if ($tokens[$stackPtr]['code'] === T_BREAK && isset($tokens[$stackPtr]['scope_opener']) === true)

        {

            // This break closes the scope of a CASE or DEFAULT statement
            // so any code between this token and the next CASE, DEFAULT or
            // end of SWITCH token will not be executable.
            $next = $phpcsFile->findNext(array(T_CASE, T_DEFAULT, 

                    T_CLOSE_CURLY_BRACKET), ($stackPtr + 1));

            

            if ($next !== false)

            {

                $lastLine = $tokens[($stackPtr + 1)]['line'];

                for($i = ($stackPtr + 1); $i < $next; $i ++)

                {

                    if (in_array($tokens[$i]['code'], PHP_CodeSniffer_Tokens :: $emptyTokens) === true)

                    {

                        continue;

                    }

                    

                    $line = $tokens[$i]['line'];

                    if ($line > $lastLine)

                    {

                        $type = substr($tokens[$stackPtr]['type'], 2);

                        $warning = "Code after $type statement cannot be executed";

                        $phpcsFile->addWarning($warning, $i, 'Unreachable');

                        $lastLine = $line;

                    }

                }

            } //end if
            



            // That's all we have to check for these types of BREAK statements.
            return;

        } //end if
        



        // This token may be part of an inline condition.
        // If we find a closing parenthesis that belongs to a condition
        // we should ignore this token.
        $prev = $phpcsFile->findPrevious(PHP_CodeSniffer_Tokens :: $emptyTokens, ($stackPtr - 1), null, true);

        if (isset($tokens[$prev]['parenthesis_owner']) === true)

        {

            $owner = $tokens[$prev]['parenthesis_owner'];

            $ignore = array(T_IF, T_ELSE, T_ELSEIF);

            if (in_array($tokens[$owner]['code'], $ignore) === true)

            {

                return;

            }

        }

        

        $ourConditions = array_keys($tokens[$stackPtr]['conditions']);

        $ourTokens = $this->register();

        $hasConditions = empty($ourConditions);

        

        // Skip this token if it is non-executable code itself.
        if ($hasConditions === false)

        {

            for($i = ($stackPtr - 1); $i >= 1; $i --)

            {

                // Skip tokens that close the scope. They don't end
                // the execution of code.
                if (isset($tokens[$i]['scope_opener']) === true)

                {

                    continue;

                }

                

                // Skip tokens that do not end execution.
                if (in_array($tokens[$i]['code'], $ourTokens) === false)

                {

                    continue;

                }

                

                if (empty($tokens[$i]['conditions']) === true)

                {

                    // Found an end of execution token in the global
                    // scope, so it will be executed before us.
                    return;

                }

                

                // If the deepest condition this token is in also happens
                // to be a condition we are in, it will get executed before us.
                $conditions = array_keys($tokens[$i]['conditions']);

                $condition = array_pop($conditions);

                if (in_array($condition, $ourConditions) === true)

                {

                    return;

                }

            } //end for
        }

        else

        {

            // Look for other end of execution tokens in the global scope.
            for($i = ($stackPtr - 1); $i >= 1; $i --)

            {

                if (in_array($tokens[$i]['code'], $ourTokens) === false)

                {

                    continue;

                }

                

                if (empty($tokens[$i]['conditions']) === false)

                {

                    continue;

                }

                

                // Another end of execution token was before us in the
                // global scope, so we are not executable.
                return;

            }

        } //end if
        



        if ($hasConditions === false)

        {

            $condition = array_pop($ourConditions);

            

            if (isset($tokens[$condition]['scope_closer']) === false)

            {

                return;

            }

            

            $closer = $tokens[$condition]['scope_closer'];

            

            // If the closer for our condition is shared with other openers,
            // we will need to throw errors from this token to the next
            // shared opener (if there is one), not to the scope closer.
            $nextOpener = null;

            for($i = ($stackPtr + 1); $i < $closer; $i ++)

            {

                if (isset($tokens[$i]['scope_closer']) === true)

                {

                    if ($tokens[$i]['scope_closer'] === $closer)

                    {

                        // We found an opener that shares the same
                        // closing token as us.
                        $nextOpener = $i;

                        break;

                    }

                }

            } //end for
            



            $start = $phpcsFile->findNext(T_SEMICOLON, ($stackPtr + 1));

            

            if ($nextOpener === null)

            {

                $end = $closer;

            }

            else

            {

                $end = $nextOpener;

            }

        }

        else

        {

            // This token is in the global scope.
            if ($tokens[$stackPtr]['code'] === T_BREAK)

            {

                return;

            }

            

            // Throw an error for all lines until the end of the file.
            $start = $phpcsFile->findNext(T_SEMICOLON, ($stackPtr + 1));

            $end = ($phpcsFile->numTokens - 1);

        } //end if
        



        $lastLine = $tokens[$start]['line'];

        for($i = ($start + 1); $i < $end; $i ++)

        {

            if (in_array($tokens[$i]['code'], PHP_CodeSniffer_Tokens :: $emptyTokens) === true)

            {

                continue;

            }

            

            $line = $tokens[$i]['line'];

            if ($line > $lastLine)

            {

                $type = substr($tokens[$stackPtr]['type'], 2);

                $warning = "Code after $type statement cannot be executed";

                $phpcsFile->addWarning($warning, $i, 'Unreachable');

                $lastLine = $line;

            }

        }

    

    } //end process()




} //end class




?>