tests/parser/fuzzTest.php

   1 <?php
   2
   3 use Wikimedia\ScopedCallback;
   4
   5 require __DIR__ . '/../../maintenance/Maintenance.php';
   6
   7 // Make RequestContext::resetMain() happy
   8 define( 'MW_PARSER_TEST', 1 );
   9
  10 class ParserFuzzTest extends Maintenance {
  11         private $parserTest;
  12         private $maxFuzzTestLength = 300;
  13         private $memoryLimit = 100;
  14         private $seed;
  15
  16         function __construct() {
  17                 parent::__construct();
  18                 $this->addDescription( 'Run a fuzz test on the parser, until it segfaults ' .
  19                         'or throws an exception' );
  20                 $this->addOption( 'file', 'Use the specified file as a dictionary, ' .
  21                         ' or leave blank to use parserTests.txt', false, true, true );
  22
  23                 $this->addOption( 'seed', 'Start the fuzz test from the specified seed', false, true );
  24         }
  25
  26         function finalSetup() {
  27                 self::requireTestsAutoloader();
  28                 TestSetup::applyInitialConfig();
  29         }
  30
  31         function execute() {
  32                 $files = $this->getOption( 'file', [ __DIR__ . '/parserTests.txt' ] );
  33                 $this->seed = intval( $this->getOption( 'seed', 1 ) ) - 1;
  34                 $this->parserTest = new ParserTestRunner(
  35                         new MultiTestRecorder,
  36                         [] );
  37                 $this->fuzzTest( $files );
  38         }
  39
  40         /**
  41          * Run a fuzz test series
  42          * Draw input from a set of test files
  43          * @param array $filenames
  44          */
  45         function fuzzTest( $filenames ) {
  46                 $dict = $this->getFuzzInput( $filenames );
  47                 $dictSize = strlen( $dict );
  48                 $logMaxLength = log( $this->maxFuzzTestLength );
  49
  50                 $teardown = $this->parserTest->staticSetup();
  51                 $teardown = $this->parserTest->setupDatabase( $teardown );
  52                 $teardown = $this->parserTest->setupUploads( $teardown );
  53
  54                 $fakeTest = [
  55                         'test' => '',
  56                         'desc' => '',
  57                         'input' => '',
  58                         'result' => '',
  59                         'options' => '',
  60                         'config' => ''
  61                 ];
  62
  63                 ini_set( 'memory_limit', $this->memoryLimit * 1048576 * 2 );
  64
  65                 $numTotal = 0;
  66                 $numSuccess = 0;
  67                 $user = new User;
  68                 $opts = ParserOptions::newFromUser( $user );
  69                 $title = Title::makeTitle( NS_MAIN, 'Parser_test' );
  70
  71                 while ( true ) {
  72                         // Generate test input
  73                         mt_srand( ++$this->seed );
  74                         $totalLength = mt_rand( 1, $this->maxFuzzTestLength );
  75                         $input = '';
  76
  77                         while ( strlen( $input ) < $totalLength ) {
  78                                 $logHairLength = mt_rand( 0, 1000000 ) / 1000000 * $logMaxLength;
  79                                 $hairLength = min( intval( exp( $logHairLength ) ), $dictSize );
  80                                 $offset = mt_rand( 0, $dictSize - $hairLength );
  81                                 $input .= substr( $dict, $offset, $hairLength );
  82                         }
  83
  84                         $perTestTeardown = $this->parserTest->perTestSetup( $fakeTest );
  85                         $parser = $this->parserTest->getParser();
  86
  87                         // Run the test
  88                         try {
  89                                 $parser->parse( $input, $title, $opts );
  90                                 $fail = false;
  91                         } catch ( Exception $exception ) {
  92                                 $fail = true;
  93                         }
  94
  95                         if ( $fail ) {
  96                                 echo "Test failed with seed {$this->seed}\n";
  97                                 echo "Input:\n";
  98                                 printf( "string(%d) \"%s\"\n\n", strlen( $input ), $input );
  99                                 echo "$exception\n";
 100                         } else {
 101                                 $numSuccess++;
 102                         }
 103
 104                         $numTotal++;
 105                         ScopedCallback::consume( $perTestTeardown );
 106
 107                         if ( $numTotal % 100 == 0 ) {
 108                                 $usage = intval( memory_get_usage( true ) / $this->memoryLimit / 1048576 * 100 );
 109                                 echo "{$this->seed}: $numSuccess/$numTotal (mem: $usage%)\n";
 110                                 if ( $usage >= 100 ) {
 111                                         echo "Out of memory:\n";
 112                                         $memStats = $this->getMemoryBreakdown();
 113
 114                                         foreach ( $memStats as $name => $usage ) {
 115                                                 echo "$name: $usage\n";
 116                                         }
 117                                         if ( function_exists( 'hphpd_break' ) ) {
 118                                                 hphpd_break();
 119                                         }
 120                                         return;
 121                                 }
 122                         }
 123                 }
 124         }
 125
 126         /**
 127          * Get a memory usage breakdown
 128          * @return array
 129          */
 130         function getMemoryBreakdown() {
 131                 $memStats = [];
 132
 133                 foreach ( $GLOBALS as $name => $value ) {
 134                         $memStats['$' . $name] = $this->guessVarSize( $value );
 135                 }
 136
 137                 $classes = get_declared_classes();
 138
 139                 foreach ( $classes as $class ) {
 140                         $rc = new ReflectionClass( $class );
 141                         $props = $rc->getStaticProperties();
 142                         $memStats[$class] = $this->guessVarSize( $props );
 143                         $methods = $rc->getMethods();
 144
 145                         foreach ( $methods as $method ) {
 146                                 $memStats[$class] += $this->guessVarSize( $method->getStaticVariables() );
 147                         }
 148                 }
 149
 150                 $functions = get_defined_functions();
 151
 152                 foreach ( $functions['user'] as $function ) {
 153                         $rf = new ReflectionFunction( $function );
 154                         $memStats["$function()"] = $this->guessVarSize( $rf->getStaticVariables() );
 155                 }
 156
 157                 asort( $memStats );
 158
 159                 return $memStats;
 160         }
 161
 162         /**
 163          * Estimate the size of the input variable
 164          */
 165         function guessVarSize( $var ) {
 166                 $length = 0;
 167                 try {
 168                         Wikimedia\suppressWarnings();
 169                         $length = strlen( serialize( $var ) );
 170                         Wikimedia\restoreWarnings();
 171                 } catch ( Exception $e ) {
 172                 }
 173                 return $length;
 174         }
 175
 176         /**
 177          * Get an input dictionary from a set of parser test files
 178          * @param array $filenames
 179          * @return string
 180          */
 181         function getFuzzInput( $filenames ) {
 182                 $dict = '';
 183
 184                 foreach ( $filenames as $filename ) {
 185                         $contents = file_get_contents( $filename );
 186                         preg_match_all(
 187                                 '/!!\s*(input|wikitext)\n(.*?)\n!!\s*(result|html|html\/\*|html\/php)/s',
 188                                 $contents,
 189                                 $matches
 190                         );
 191
 192                         foreach ( $matches[1] as $match ) {
 193                                 $dict .= $match . "\n";
 194                         }
 195                 }
 196
 197                 return $dict;
 198         }
 199 }
 200
 201 $maintClass = 'ParserFuzzTest';
 202 require RUN_MAINTENANCE_IF_MAIN;