Review unknown code with static analysis
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The document discusses static analysis of PHP code, highlighting the challenges of reviewing unknown code without running or understanding it, emphasizing the need for tools to query structured source code. It details various tools and methods for analyzing PHP code, migration between versions, and best practices for maintaining code quality. The speaker, Damien Seguy, presents insights into automated code review, issues identified through static analysis, and metrics related to code complexity and structure.
![Semantics and definitions
Removes spaces, comments, documentations
Removes delimiters
( ) { } [ ] " ' ` ; :
Good network to link definition with usage](https://image.slidesharecdn.com/reviewunknowncodewithstaticanalysis-amersfoort-170615091630/85/Review-unknown-code-with-static-analysis-25-320.jpg)
![Classes
[EmployeesController] => 1
[ProductSearchController] => 1
[Services_Twilio_RestException] => 1
[RegisterForm] => 1
[BorrowBook] => 1
[Floor] => 1
[MessageController] => 1
[RInstaller] => 1
[AuthItemForm] => 1
[EmployeesSubjects] => 1
[Services_Twilio_UsageResource] => 1
[EmployeeAttendancesController] => 1
[Logo] => 1
[StudentAdditionalFields] => 1
[AttendanceModule] => 1
[DefaultsubjectsController] => 1
[EmployeeDepartments] => 1
[LogoutController] => 1
[EventsController] => 1
[SmsSettings] => 1
[UserChangePassword] => 1
[ElectiveGroupsController] => 2
[ElectivesController] => 2
[UserController] => 2
[Settings] => 2
[CKEditor] => 2
[CoursesController] => 2
[User] => 2
[UserIdentity] => 3
[SavedsearchesController] => 3
[StudentAttentanceController] => 3
[PDF] => 5
[Message] => 5
[DefaultController] => 22](https://image.slidesharecdn.com/reviewunknowncodewithstaticanalysis-amersfoort-170615091630/85/Review-unknown-code-with-static-analysis-39-320.jpg)
![Variables
[$config] => 288
[$command] => 303
[$proc] => 324
[$c] => 336
[$url] => 337
[$index] => 352
[$type] => 352
[$file] => 361
[$token] => 417
[$time] => 443
[$column] => 474
[$options] => 475
[$className] => 489
[$sql] => 519
[$log] => 544
[$entry] => 575
[$message] => 584
[$attribute] => 587
[$key] => 676
[$params] => 711
[$table] => 858
[$htmlOptions] => 885
[$i] => 1123
[$id] => 1228
[$value] => 1596
[$criteria] => 2072
[$name] => 2250
[$data] => 2368
[$form] => 3393
[$model] => 7075
Also :
684 used-once variables](https://image.slidesharecdn.com/reviewunknowncodewithstaticanalysis-amersfoort-170615091630/85/Review-unknown-code-with-static-analysis-40-320.jpg)
Review unknown code with static analysis
- 1. REVIEW UNKNOWN CODE WITH STATIC ANALYSIS Amersfoort, Netherlands, June 2017
- 2. Agenda Reviewing code Static analysis for PHP A session in which you are the hero
- 3. Review this code We don't know what it does We have never heard about it We don't run it We don't know the authors Can we form an opinion?
- 4. How to review code Reading code is humanly possible : its an art Unit test are not adapted for review Dynamic analysis is not fit for review We need to explore code We cannot only rely on the current state
- 5. Speaker Damien Seguy Exakat CTO Static analysis for PHP PHP doc author Ik spreek geen nederlandse
- 6. Source code is structured Source code is a structured database All we need is tools to query it This is static analysis
- 8. Appinfo() List PHP features Focus on PHP's specifics
- 9. PHP Features
- 14. Application favorites Many solutions to the same problem Impact on PHP is minimal Generate never-ending discussions Rule : choose one, stick to it
- 17. Automated code review Analyze code Report PHP related problems
- 19. Clean code for PHP Best practices Security, performance, clean code in-house, PSR, calisthenics, other inspirations Code mantras, code kata PHP Manual Migration guides
- 20. Results by files
- 21. Exakat : 350 analysis Analysis Freq. Here function __destruct() { throw …} : 0,3 % 0 0.3% 0 function foo($a, $a, $a) {} 2.0% 0 !!(expression) 1.0% 1 substr($a, 2, 4) == 'abc' 9.0% 0 $a ? $b ? $c : $d : $e 11% 0 foreach($a as &$b) {} 15% 6 if (strpos($a, $b)) {} 55% 15 include('file.php') 75% 263
- 22. PHP 7.0 compatibility List of directives
- 23. Automated code review Semantic read of the code Reports interesting issues Works with AST
- 24. Automated code review PHP 5 / 7 Calisthenics ClearPHP Performance
- 25. Semantics and definitions Removes spaces, comments, documentations Removes delimiters ( ) { } [ ] " ' ` ; : Good network to link definition with usage
- 28. Flow Control Graph <?php $x = source(); if ($x < 10) { $y = $x + 1; $a = 3; $x = corrige($y); } else { $y = $x; } $x = source; if ($x < 10) $y = $x; $y = $x + 1; $x = corrige($y); end $a = 3; start
- 29. Data Dependency Graph <?php $x = source(); if ($x < 10) { $y = $x + 1; $a = 3; $x = corrige($y); } else { $y = $x; } $x = source; if ($x < 10) $y = $x;$y = $x + 1; $x = corrige($y); fin(); Depends onDepends on Depends on notDepends on Depends on $a = 3; Depends on
- 30. Various AST PHP7mar : nikic/php5-ast PHAN : ext/ast (PHP 7 only) Exakat : AST in a graph database SonarQube : Java-build AST PHPstorm : internal IDE AST
- 31. PHAN protected/views/book/admin.php:7 PhanUndeclaredVariable Variable $this is undeclared Total : 5194 results / 36 types 2967 issues /protected/views/configurations/_form.php:22 PhanTypeMismatchArgument Argument 1 (pk) is int but EmployeeAttendances::findByPk() takes array|null defined at core/yiilite.php:7230 475 issues core/utils/CMarkdownParser.php:81 PhanUndeclaredClassMethod Call to method purify from undeclared class HTMLPurifier core/utils/CMarkdownParser.php:99 PhanUndeclaredClassMethod Call to method outdent from undeclared class MarkdownExtra_Parse core/caching/CMemCache.php:111 PhanUndeclaredClassMethod Call to method __construct from undeclared class Memcache 323 issues protected/controllers/LeadsController.php:352 PhanUndeclaredConstant Reference to undeclared constant MENU_TITLE protected/controllers/LeadsController.php:353 PhanUndeclaredConstant Reference to undeclared constant MENU_URL protected/controllers/LeadsController.php:354 PhanUndeclaredConstant Reference to undeclared constant MENU_CLASS protected/modules/courses/views/courses/left_side.php:49 PhanRedefineFunction Function t protected/modules/courses/views/studentAttentance/attentstud.php:30 PhanRedefineFunction Function getweek 166 issues 32 issues
- 32. PHP 7 helps static analysis Type hint, return type hint, scalar typehint Usage of PHPDOC Consistent behavior of PHP operators Dynamic code is very difficult to analyze
- 33. PHP LINT php -l <fichier.php> Paralell executions jakub-onderka/php-paralell-lint Various versions of PHP : 7.0, 7.1, 7.2, 5.6, 5.5
- 34. Checked 2795 files in 16.4 seconds Syntax error found in 1 file ------------------------------------------------------------ Parse error: protected/vendors/MPDF/mpdf.php:1417 1415| case 'DEMY': {$format=array(382.68,612.28 ); break;} // 'Demy' 1416| case 'ROYAL': {$format=array(433.70,663.30 ); break;} // 'Royal' f > 1417| default: $format = false; 1418| } 1419| return $format; Fatal error: Switch statements may only contain one default clause PHP LINT - 7.0/1
- 35. PHP LINT - 5.4/5/6 - 7.2 No syntax error found ??
- 36. 0 1.25 2.5 3.75 5 5.2 5.3 5.4 5.5 5.6 7.0 7.1 7.2 0 1 2 3 4 5.2 5.3 5.4 5.5 5.6 7.0 7.1 7.2 0 0.75 1.5 2.25 3 5.2 5.3 5.4 5.5 5.6 7.0 7.1 7.2 0 1.75 3.5 5.25 7 5.2 5.3 5.4 5.5 5.6 7.0 7.1 7.2 5.2 5.3 5.4 5.5 5.6 7.0 7.1 7.2 5.2 5.3 5.4 5.5 5.6 7.0 7.1 7.2 5.2 5.3 5.4 5.5 5.6 7.0 7.1 7.2 5.2 5.3 5.4 5.5 5.6 7.0 7.1 7.2
- 37. What does this app do? Inventories of the application Names for classes, methods, traits, variables, interfaces… List of literal in the code Integers, real, arrays, strings
- 38. Errors messages
- 39. Classes [EmployeesController] => 1 [ProductSearchController] => 1 [Services_Twilio_RestException] => 1 [RegisterForm] => 1 [BorrowBook] => 1 [Floor] => 1 [MessageController] => 1 [RInstaller] => 1 [AuthItemForm] => 1 [EmployeesSubjects] => 1 [Services_Twilio_UsageResource] => 1 [EmployeeAttendancesController] => 1 [Logo] => 1 [StudentAdditionalFields] => 1 [AttendanceModule] => 1 [DefaultsubjectsController] => 1 [EmployeeDepartments] => 1 [LogoutController] => 1 [EventsController] => 1 [SmsSettings] => 1 [UserChangePassword] => 1 [ElectiveGroupsController] => 2 [ElectivesController] => 2 [UserController] => 2 [Settings] => 2 [CKEditor] => 2 [CoursesController] => 2 [User] => 2 [UserIdentity] => 3 [SavedsearchesController] => 3 [StudentAttentanceController] => 3 [PDF] => 5 [Message] => 5 [DefaultController] => 22
- 40. Variables [$config] => 288 [$command] => 303 [$proc] => 324 [$c] => 336 [$url] => 337 [$index] => 352 [$type] => 352 [$file] => 361 [$token] => 417 [$time] => 443 [$column] => 474 [$options] => 475 [$className] => 489 [$sql] => 519 [$log] => 544 [$entry] => 575 [$message] => 584 [$attribute] => 587 [$key] => 676 [$params] => 711 [$table] => 858 [$htmlOptions] => 885 [$i] => 1123 [$id] => 1228 [$value] => 1596 [$criteria] => 2072 [$name] => 2250 [$data] => 2368 [$form] => 3393 [$model] => 7075 Also : 684 used-once variables
- 41. Metrics Provides measures values about the code Cyclomatic complexity, LOC, Maintenance index
- 42. Directories 1143 Files 5982 Size Lines of Code (LOC) 835199 Comment Lines of Code (CLOC) 252075 (30.18%) Non-Comment Lines of Code (NCLOC) 583124 (69.82%) Logical Lines of Code (LLOC) 195283 (23.38%) Classes 178062 (91.18%) Average Class Length 29 Minimum Class Length 0 Maximum Class Length 3141 Average Method Length 4 Minimum Method Length 0 Maximum Method Length 879 Functions 1477 (0.76%) Average Function Length 1 Not in classes or functions 15744 (8.06%) Cyclomatic Complexity Average Complexity per LLOC 0.30 Average Complexity per Class 10.82 Minimum Class Complexity 1.00 Maximum Class Complexity 1177.00 Average Complexity per Method 2.65 Minimum Method Complexity 1.00 Maximum Method Complexity 387.00 PHPLOC
- 43. PHPMetrics
- 44. PHPMetrics
- 45. Going even further Dynamic code 40% of the code is actually constant Taint analysis Transpilage : https://github.com/jaytaph/Transphpile PHP inspections : Integrated in phpStorm Integrate static analysis in pipeline
- 46. List of PHP analyzers Exakat Phan Phploc PHP 7 cc PHPmetrics https://github.com/exakat/ php-static-analysis-tools
- 47. Large application One framework (Yii) many old libraries (MPDF, PEAR) Low level of issues Tend to favorite old PHP features Backward compatibilities Deal with school : students, books, elections
- 48. open-school.org