check_parameters.php

#!/usr/bin/env php
<?php
/*
  +----------------------------------------------------------------------+
  | Copyright (c) The PHP Group                                          |
  +----------------------------------------------------------------------+
  | This source file is subject to version 3.01 of the PHP license,      |
  | that is bundled with this package in the file LICENSE, and is        |
  | available through the world-wide-web at the following url:           |
  | https://www.php.net/license/3_01.txt                                 |
  | If you did not receive a copy of the PHP license and are unable to   |
  | obtain it through the world-wide-web, please send a note to          |
  | license@php.net so we can mail you a copy immediately.               |
  +----------------------------------------------------------------------+
  | Author: Nuno Lopes <nlopess@php.net>                                 |
  +----------------------------------------------------------------------+
*/

define('REPORT_LEVEL', 1); // 0 reports less false-positives. up to level 5.
define('VERSION', '7.0');  // minimum is 7.0
define('PHPDIR', realpath(dirname(__FILE__) . '/../..'));


// be sure you have enough memory and stack for PHP. pcre will push the limits!
ini_set('pcre.backtrack_limit', 10000000);


// ------------------------ end of config ----------------------------


$API_params = array(
    'a' => array('zval**'), // array
    'A' => array('zval**'), // array or object
    'b' => array('bool*'), // boolean
    'd' => array('double*'), // double
    'f' => array('zend_fcall_info*', 'zend_fcall_info_cache*'), // function
    'h' => array('HashTable**'), // array as an HashTable*
    'H' => array('HashTable**'), // array or HASH_OF(object)
    'l' => array('zend_long*'), // long
    //TODO 'L' => array('zend_long*, '), // long
    'o' => array('zval**'), //object
    'O' => array('zval**', 'zend_class_entry*'), // object of given type
    'P' => array('zend_string**'), // valid path
    'r' => array('zval**'), // resource
    'S' => array('zend_string**'), // string
    'z' => array('zval**'), // zval*
    'Z' => array('zval***') // zval**
    // 's', 'p', 'C' handled separately
);

/** reports an error, according to its level */
function error($str, $level = 0)
{
    global $current_file, $current_function, $line;

    if ($level <= REPORT_LEVEL) {
        if (strpos($current_file,PHPDIR) === 0) {
            $filename = substr($current_file, strlen(PHPDIR)+1);
        } else {
            $filename = $current_file;
        }
        echo $filename , " [$line] $current_function : $str\n";
    }
}


/** this updates the global var $line (for error reporting) */
function update_lineno($offset)
{
    global $lines_offset, $line;

    $left  = 0;
    $right = $count = count($lines_offset)-1;

    // a nice binary search :)
    do {
        $mid = intval(($left + $right)/2);
        $val = $lines_offset[$mid];

        if ($val < $offset) {
            if (++$mid > $count || $lines_offset[$mid] > $offset) {
                $line = $mid;
                return;
            } else {
                $left = $mid;
            }
        } else if ($val > $offset) {
            if ($lines_offset[--$mid] < $offset) {
                $line = $mid+1;
                return;
            } else {
                $right = $mid;
            }
        } else {
            $line = $mid+1;
            return;
        }
    } while (true);
}


/** parses the sources and fetches its vars name, type and if they are initialized or not */
function get_vars($txt)
{
    $ret =  array();
    preg_match_all('/((?:(?:unsigned|struct)\s+)?\w+)(?:\s*(\*+)\s+|\s+(\**))(\w+(?:\[\s*\w*\s*\])?)\s*(?:(=)[^,;]+)?((?:\s*,\s*\**\s*\w+(?:\[\s*\w*\s*\])?\s*(?:=[^,;]+)?)*)\s*;/S', $txt, $m, PREG_SET_ORDER);

    foreach ($m as $x) {
        // the first parameter is special
        if (!in_array($x[1], array('else', 'endif', 'return'))) // hack to skip reserved words
            $ret[$x[4]] = array($x[1] . $x[2] . $x[3], $x[5]);

        // are there more vars?
        if ($x[6]) {
            preg_match_all('/(\**)\s*(\w+(?:\[\s*\w*\s*\])?)\s*(=?)/S', $x[6], $y, PREG_SET_ORDER);
            foreach ($y as $z) {
                $ret[$z[2]] = array($x[1] . $z[1], $z[3]);
            }
        }
    }

//	if ($GLOBALS['current_function'] == 'for_debugging') { print_r($m);print_r($ret); }
    return $ret;
}


/** run diagnostic checks against one var. */
function check_param($db, $idx, $exp, $optional, $allow_uninit = false)
{
    global $error_few_vars_given;

    if ($idx >= count($db)) {
        if (!$error_few_vars_given) {
            error("too few variables passed to function");
            $error_few_vars_given = true;
        }
        return;
    } elseif ($db[$idx][0] === '**dummy**') {
        return;
    }

    if ($db[$idx][1] != $exp) {
        error("{$db[$idx][0]}: expected '$exp' but got '{$db[$idx][1]}' [".($idx+1).']');
    }

    if (!$optional && $db[$idx][2]) {
        error("not optional var is initialized: {$db[$idx][0]} [".($idx+1).']', 2);
    }
    if (!$allow_uninit && $optional && !$db[$idx][2]) {
        error("optional var not initialized: {$db[$idx][0]} [".($idx+1).']', 1);
    }
}

/** fetch params passed to zend_parse_params*() */
function get_params($vars, $str)
{
    $ret = array();
    preg_match_all('/(?:\([^)]+\))?(&?)([\w>.()-]+(?:\[\w+\])?)\s*,?((?:\)*\s*=)?)/S', $str, $m, PREG_SET_ORDER);

    foreach ($m as $x) {
        $name = $x[2];

        // little hack for last parameter
        if (strpos($name, '(') === false) {
            $name = rtrim($name, ')');
        }

        if (empty($vars[$name][0])) {
            error("variable not found: '$name'", 3);
            $ret[][] = '**dummy**';

        } else {
            $ret[] = array($name, $vars[$name][0] . ($x[1] ? '*' : ''), $vars[$name][1]);
        }

        // the end (yes, this is a little hack :P)
        if ($x[3]) {
            break;
        }
    }

//	if ($GLOBALS['current_function'] == 'for_debugging') { var_dump($m); var_dump($ret); }
    return $ret;
}


/** run tests on a function. the code is passed in $txt */
function check_function($name, $txt, $offset)
{
    global $API_params;

    $regex = '/
        (?: zend_parse_parameters(?:_throw)?               \s*\([^,]+
        |   zend_parse_(?:parameters_ex|method_parameters) \s*\([^,]+,[^,]+
        |   zend_parse_method_parameters_ex                \s*\([^,]+,[^,]+,[^,+]
        )
        ,\s*"([^"]*)"\s*
        ,\s*([^{;]*)
    /Sx';
    if (preg_match_all($regex, $txt, $matches, PREG_SET_ORDER | PREG_OFFSET_CAPTURE)) {

        $GLOBALS['current_function'] = $name;

        foreach ($matches as $m) {
            $GLOBALS['error_few_vars_given'] = false;
            update_lineno($offset + $m[2][1]);

            $vars = get_vars(substr($txt, 0, $m[0][1])); // limit var search to current location
            $params = get_params($vars, $m[2][0]);
            $optional = $varargs = false;
            $last_char = '';
            $j = -1;

            $spec = $m[1][0];
            $len = strlen($spec);
            for ($i = 0; $i < $len; ++$i) {
                $char = $spec[$i];
                switch ($char = $spec[$i]) {
                    // separator for optional parameters
                    case '|':
                        if ($optional) {
                            error("more than one optional separator at char #$i");
                        } else {
                            $optional = true;
                            if ($i == $len-1) {
                                error("unnecessary optional separator");
                            }
                        }
                    break;

                    // separate_zval_if_not_ref
                    case '/':
                        if (in_array($last_char, array('l', 'L', 'd', 'b'))) {
                            error("the '/' specifier should not be applied to '$last_char'");
                        }
                    break;

                    // nullable arguments
                    case '!':
                        if (in_array($last_char, array('l', 'L', 'd', 'b'))) {
                            check_param($params, ++$j, 'bool*', $optional);
                        }
                    break;

                    // variadic arguments
                    case '+':
                    case '*':
                        if ($varargs) {
                            error("A varargs specifier can only be used once. repeated char at column $i");
                        } else {
                            check_param($params, ++$j, 'zval**', $optional);
                            check_param($params, ++$j, 'int*', $optional);
                            $varargs = true;
                        }
                    break;

                    case 's':
                    case 'p':
                        check_param($params, ++$j, 'char**', $optional, $allow_uninit=true);
                        check_param($params, ++$j, 'size_t*', $optional, $allow_uninit=true);
                        if ($optional && !$params[$j-1][2] && !$params[$j][2]
                                && $params[$j-1][0] !== '**dummy**' && $params[$j][0] !== '**dummy**') {
                            error("one of optional vars {$params[$j-1][0]} or {$params[$j][0]} must be initialized", 1);
                        }
                    break;

                    case 'C':
                        // C must always be initialized, independently of whether it's optional
                        check_param($params, ++$j, 'zend_class_entry**', false);
                    break;

                    default:
                        if (!isset($API_params[$char])) {
                            error("unknown char ('$char') at column $i");
                        }

                        // If an is_null flag is in use, only that flag is required to be
                        // initialized
                        $allow_uninit = $i+1 < $len && $spec[$i+1] === '!'
                                && in_array($char, array('l', 'L', 'd', 'b'));

                        foreach ($API_params[$char] as $exp) {
                            check_param($params, ++$j, $exp, $optional, $allow_uninit);
                        }
                }

                $last_char = $char;
            }
        }
    }
}


/** the main recursion function. splits files in functions and calls the other functions */
function recurse($path)
{
    foreach (scandir($path) as $file) {
        if ($file == '.' || $file == '..' || $file == 'CVS') continue;

        $file = "$path/$file";
        if (is_dir($file)) {
            recurse($file);
            continue;
        }

        // parse only .c and .cpp files
        if (substr_compare($file, '.c', -2) && substr_compare($file, '.cpp', -4)) continue;

        $txt = file_get_contents($file);
        // remove comments (but preserve the number of lines)
        $txt = preg_replace('@//.*@S', '', $txt);
        $txt = preg_replace_callback('@/\*.*\*/@SsU', function($matches) {
            return preg_replace("/[^\r\n]+/S", "", $matches[0]);
        }, $txt);

        $split = preg_split('/PHP_(?:NAMED_)?(?:FUNCTION|METHOD)\s*\((\w+(?:,\s*\w+)?)\)/S', $txt, -1, PREG_SPLIT_DELIM_CAPTURE | PREG_SPLIT_OFFSET_CAPTURE);

        if (count($split) < 2) continue; // no functions defined on this file
        array_shift($split); // the first part isn't relevant


        // generate the line offsets array
        $j = 0;
        $lines = preg_split("/(\r\n?|\n)/S", $txt, -1, PREG_SPLIT_DELIM_CAPTURE);
        $lines_offset = array();

        for ($i = 0; $i < count($lines); ++$i) {
            $j += strlen($lines[$i]) + strlen(@$lines[++$i]);
            $lines_offset[] = $j;
        }

        $GLOBALS['lines_offset'] = $lines_offset;
        $GLOBALS['current_file'] = $file;


        for ($i = 0; $i < count($split); $i+=2) {
            // if the /* }}} */ comment is found use it to reduce false positives
            // TODO: check the other indexes
            list($f) = preg_split('@/\*\s*}}}\s*\*/@S', $split[$i+1][0]);
            check_function(preg_replace('/\s*,\s*/S', '::', $split[$i][0]), $f, $split[$i][1]);
        }
    }
}

$dirs = array();

if (isset($argc) && $argc > 1) {
    if ($argv[1] == '-h' || $argv[1] == '-help' || $argv[1] == '--help') {
        echo <<<HELP
Synopsis:
    php check_parameters.php [directories]

HELP;
        exit(0);
    }
    for ($i = 1; $i < $argc; $i++) {
        $dirs[] = $argv[$i];
    }
} else {
    $dirs[] = PHPDIR;
}

foreach($dirs as $dir) {
    if (is_dir($dir)) {
        if (!is_readable($dir)) {
            echo "ERROR: directory '", $dir ,"' is not readable\n";
            exit(1);
        }
    } else {
        echo "ERROR: bogus directory '", $dir ,"'\n";
        exit(1);
    }
}

foreach ($dirs as $dir) {
    recurse(realpath($dir));
}