Add a linter rule for parent references

Summary:
Add a linter rule to detect static method calls which //should// reference the `parent` class instead of a hardcoded class reference. For example, consider the following:

```lang=php, counterexample
class SomeClass extends AnotherClass {
  public function someMethod() {
    AnotherClass::someOtherMethod();
  }
}
```

This should instead be written as:

```lang=php
class SomeClass extends AnotherClass {
  public function someMethod() {
    parent::someOtherMethod();
  }
}
```

Test Plan: Added unit tests.

Reviewers: epriestley, #blessed_reviewers

Reviewed By: epriestley, #blessed_reviewers

Subscribers: Korvin, epriestley

Differential Revision: https://secure.phabricator.com/D14443

src/__phutil_library_map__.php

@@ -248,6 +248,8 @@ phutil_register_library_map(array(
     'ArcanistPHPOpenTagXHPASTLinterRuleTestCase' => 'lint/linter/xhpast/rules/__tests__/ArcanistPHPOpenTagXHPASTLinterRuleTestCase.php',
     'ArcanistPHPShortTagXHPASTLinterRule' => 'lint/linter/xhpast/rules/ArcanistPHPShortTagXHPASTLinterRule.php',
     'ArcanistPHPShortTagXHPASTLinterRuleTestCase' => 'lint/linter/xhpast/rules/__tests__/ArcanistPHPShortTagXHPASTLinterRuleTestCase.php',
+    'ArcanistParentMemberReferenceXHPASTLinterRule' => 'lint/linter/xhpast/rules/ArcanistParentMemberReferenceXHPASTLinterRule.php',
+    'ArcanistParentMemberReferenceXHPASTLinterRuleTestCase' => 'lint/linter/xhpast/rules/__tests__/ArcanistParentMemberReferenceXHPASTLinterRuleTestCase.php',
     'ArcanistParenthesesSpacingXHPASTLinterRule' => 'lint/linter/xhpast/rules/ArcanistParenthesesSpacingXHPASTLinterRule.php',
     'ArcanistParenthesesSpacingXHPASTLinterRuleTestCase' => 'lint/linter/xhpast/rules/__tests__/ArcanistParenthesesSpacingXHPASTLinterRuleTestCase.php',
     'ArcanistParseStrUseXHPASTLinterRule' => 'lint/linter/xhpast/rules/ArcanistParseStrUseXHPASTLinterRule.php',
@@ -618,6 +620,8 @@ phutil_register_library_map(array(
     'ArcanistPHPOpenTagXHPASTLinterRuleTestCase' => 'ArcanistXHPASTLinterRuleTestCase',
     'ArcanistPHPShortTagXHPASTLinterRule' => 'ArcanistXHPASTLinterRule',
     'ArcanistPHPShortTagXHPASTLinterRuleTestCase' => 'ArcanistXHPASTLinterRuleTestCase',
+    'ArcanistParentMemberReferenceXHPASTLinterRule' => 'ArcanistXHPASTLinterRule',
+    'ArcanistParentMemberReferenceXHPASTLinterRuleTestCase' => 'ArcanistXHPASTLinterRuleTestCase',
     'ArcanistParenthesesSpacingXHPASTLinterRule' => 'ArcanistXHPASTLinterRule',
     'ArcanistParenthesesSpacingXHPASTLinterRuleTestCase' => 'ArcanistXHPASTLinterRuleTestCase',
     'ArcanistParseStrUseXHPASTLinterRule' => 'ArcanistXHPASTLinterRule',

src/lint/linter/xhpast/rules/ArcanistParentMemberReferenceXHPASTLinterRule.php

@@ -0,0 +1,71 @@
+<?php
+
+final class ArcanistParentMemberReferenceXHPASTLinterRule
+  extends ArcanistXHPASTLinterRule {
+
+  const ID = 83;
+
+  public function getLintName() {
+    return pht('Parent Member Reference');
+  }
+
+  public function getLintSeverity() {
+    return ArcanistLintSeverity::SEVERITY_WARNING;
+  }
+
+  public function process(XHPASTNode $root) {
+    $class_declarations = $root->selectDescendantsOfType('n_CLASS_DECLARATION');
+
+    foreach ($class_declarations as $class_declaration) {
+      $extends_list = $class_declaration
+        ->getChildByIndex(2);
+      $parent_class = null;
+
+      if ($extends_list->getTypeName() == 'n_EXTENDS_LIST') {
+        $parent_class = $extends_list
+          ->getChildOfType(0, 'n_CLASS_NAME')
+          ->getConcreteString();
+      }
+
+      if (!$parent_class) {
+        continue;
+      }
+
+      $class_static_accesses = $class_declaration
+        ->selectDescendantsOfType('n_CLASS_STATIC_ACCESS');
+      $closures = $this->getAnonymousClosures($class_declaration);
+
+      foreach ($class_static_accesses as $class_static_access) {
+        $double_colons = $class_static_access
+          ->selectTokensOfType('T_PAAMAYIM_NEKUDOTAYIM');
+        $class_ref = $class_static_access->getChildByIndex(0);
+
+        if ($class_ref->getTypeName() != 'n_CLASS_NAME') {
+          continue;
+        }
+        $class_ref_name = $class_ref->getConcreteString();
+
+        if (strtolower($parent_class) == strtolower($class_ref_name)) {
+          $in_closure = false;
+
+          foreach ($closures as $closure) {
+            if ($class_ref->isDescendantOf($closure)) {
+              $in_closure = true;
+              break;
+            }
+          }
+
+          if (version_compare($this->version, '5.4.0', '>=') || !$in_closure) {
+            $this->raiseLintAtNode(
+              $class_ref,
+              pht(
+                'Use `%s` to call parent method.',
+                'parent::'),
+              'parent');
+          }
+        }
+      }
+    }
+  }
+
+}

src/lint/linter/xhpast/rules/__tests__/ArcanistParentMemberReferenceXHPASTLinterRuleTestCase.php

@@ -0,0 +1,11 @@
+<?php
+
+final class ArcanistParentMemberReferenceXHPASTLinterRuleTestCase
+  extends ArcanistXHPASTLinterRuleTestCase {
+
+  public function testLinter() {
+    $this->executeTestsInDirectory(
+      dirname(__FILE__).'/parent-member-references/');
+  }
+
+}

src/lint/linter/xhpast/rules/__tests__/parent-member-references/not-parent.lint-test

@@ -0,0 +1,7 @@
+<?php
+class Foobar {
+  public function someMethod() {
+    Bar::someOtherMethod();
+  }
+}
+~~~~~~~~~~

src/lint/linter/xhpast/rules/__tests__/parent-member-references/parent.lint-test

@@ -0,0 +1,15 @@
+<?php
+class Foo extends Bar {
+  public function someMethod() {
+    Bar::someOtherMethod();
+  }
+}
+~~~~~~~~~~
+warning:4:5
+~~~~~~~~~~
+<?php
+class Foo extends Bar {
+  public function someMethod() {
+    parent::someOtherMethod();
+  }
+}