class CallTimePassByReferenceSniff

class CallTimePassByReferenceSniff implements Sniff {
    
    /**
     * Returns an array of tokens this test wants to listen for.
     *
     * @return array<int|string>
     */
    public function register() {
        return [
            T_STRING,
            T_VARIABLE,
            T_ANON_CLASS,
            T_PARENT,
            T_SELF,
            T_STATIC,
        ];
    }
    
    //end register()
    
    /**
     * Processes this test, when one of its tokens is encountered.
     *
     * @param \PHP_CodeSniffer\Files\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(File $phpcsFile, $stackPtr) {
        $tokens = $phpcsFile->getTokens();
        $findTokens = Tokens::$emptyTokens;
        $findTokens[] = T_BITWISE_AND;
        $prev = $phpcsFile->findPrevious($findTokens, $stackPtr - 1, null, true);
        // Skip tokens that are the names of functions
        // within their definitions. For example: function myFunction...
        // "myFunction" is T_STRING but we should skip because it is not a
        // function or method *call*.
        $prevCode = $tokens[$prev]['code'];
        if ($prevCode === T_FUNCTION) {
            return;
        }
        // If the next non-whitespace token after the function or method call
        // is not an opening parenthesis then it cant really be a *call*.
        $functionName = $stackPtr;
        $openBracket = $phpcsFile->findNext(Tokens::$emptyTokens, $functionName + 1, null, true);
        if ($openBracket === false || $tokens[$openBracket]['code'] !== T_OPEN_PARENTHESIS) {
            return;
        }
        if (isset($tokens[$openBracket]['parenthesis_closer']) === false) {
            return;
        }
        $closeBracket = $tokens[$openBracket]['parenthesis_closer'];
        $nextSeparator = $openBracket;
        $find = [
            T_VARIABLE,
            T_OPEN_SHORT_ARRAY,
        ];
        while (($nextSeparator = $phpcsFile->findNext($find, $nextSeparator + 1, $closeBracket)) !== false) {
            if ($tokens[$nextSeparator]['code'] === T_OPEN_SHORT_ARRAY) {
                $nextSeparator = $tokens[$nextSeparator]['bracket_closer'];
                continue;
            }
            // Make sure the variable belongs directly to this function call
            // and is not inside a nested function call or array.
            $brackets = $tokens[$nextSeparator]['nested_parenthesis'];
            $lastBracket = array_pop($brackets);
            if ($lastBracket !== $closeBracket) {
                continue;
            }
            $tokenBefore = $phpcsFile->findPrevious(Tokens::$emptyTokens, $nextSeparator - 1, null, true);
            if ($tokens[$tokenBefore]['code'] === T_BITWISE_AND) {
                if ($phpcsFile->isReference($tokenBefore) === false) {
                    continue;
                }
                // We also want to ignore references used in assignment
                // operations passed as function arguments, but isReference()
                // sees them as valid references (which they are).
                $tokenBefore = $phpcsFile->findPrevious(Tokens::$emptyTokens, $tokenBefore - 1, null, true);
                if (isset(Tokens::$assignmentTokens[$tokens[$tokenBefore]['code']]) === true) {
                    continue;
                }
                // T_BITWISE_AND represents a pass-by-reference.
                $error = 'Call-time pass-by-reference calls are prohibited';
                $phpcsFile->addError($error, $tokenBefore, 'NotAllowed');
            }
            
            //end if
        }
        
        //end while
    }
    
    //end process()

}