[PHP 8.2] Add readonly class support (#834)

RFC: https://wiki.php.net/rfc/readonly_classes PHP implementation: php/php-src#7305
nikic · May 15, 2022 · 678ccbe · 678ccbe
1 parent 5d83adc
commit 678ccbe
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Showing 12 changed files with 1,130 additions and 929 deletions.
diff --git a/grammar/php7.y b/grammar/php7.y
@@ -382,8 +382,18 @@ enum_case_expr:
 
 class_entry_type:
       T_CLASS                                               { $$ = 0; }
-    | T_ABSTRACT T_CLASS                                    { $$ = Stmt\Class_::MODIFIER_ABSTRACT; }
-    | T_FINAL T_CLASS                                       { $$ = Stmt\Class_::MODIFIER_FINAL; }
+    | class_modifiers T_CLASS                               { $$ = $1; }
+;
+
+class_modifiers:
+      class_modifier                                        { $$ = $1; }
+    | class_modifiers class_modifier                        { $this->checkClassModifier($1, $2, #2); $$ = $1 | $2; }
+;
+
+class_modifier:
+      T_ABSTRACT                                            { $$ = Stmt\Class_::MODIFIER_ABSTRACT; }
+    | T_FINAL                                               { $$ = Stmt\Class_::MODIFIER_FINAL; }
+    | T_READONLY                                            { $$ = Stmt\Class_::MODIFIER_READONLY; }
 ;
 
 extends_from:

diff --git a/lib/PhpParser/Builder/Class_.php b/lib/PhpParser/Builder/Class_.php
@@ -67,7 +67,7 @@ public function implement(...$interfaces) {
      * @return $this The builder instance (for fluid interface)
      */
     public function makeAbstract() {
-        $this->flags = BuilderHelpers::addModifier($this->flags, Stmt\Class_::MODIFIER_ABSTRACT);
+        $this->flags = BuilderHelpers::addClassModifier($this->flags, Stmt\Class_::MODIFIER_ABSTRACT);
 
         return $this;
     }
@@ -78,7 +78,13 @@ public function makeAbstract() {
      * @return $this The builder instance (for fluid interface)
      */
     public function makeFinal() {
-        $this->flags = BuilderHelpers::addModifier($this->flags, Stmt\Class_::MODIFIER_FINAL);
+        $this->flags = BuilderHelpers::addClassModifier($this->flags, Stmt\Class_::MODIFIER_FINAL);
+
+        return $this;
+    }
+
+    public function makeReadonly() {
+        $this->flags = BuilderHelpers::addClassModifier($this->flags, Stmt\Class_::MODIFIER_READONLY);
 
         return $this;
     }

diff --git a/lib/PhpParser/BuilderHelpers.php b/lib/PhpParser/BuilderHelpers.php
@@ -310,4 +310,13 @@ public static function addModifier(int $modifiers, int $modifier) : int {
         Stmt\Class_::verifyModifier($modifiers, $modifier);
         return $modifiers | $modifier;
     }
+
+    /**
+     * Adds a modifier and returns new modifier bitmask.
+     * @return int New modifiers
+     */
+    public static function addClassModifier(int $existingModifiers, int $modifierToSet) : int {
+        Stmt\Class_::verifyClassModifier($existingModifiers, $modifierToSet);
+        return $existingModifiers | $modifierToSet;
+    }
 }
diff --git a/lib/PhpParser/Node/Stmt/Class_.php b/lib/PhpParser/Node/Stmt/Class_.php
@@ -68,6 +68,10 @@ public function isFinal() : bool {
         return (bool) ($this->flags & self::MODIFIER_FINAL);
     }
 
+    public function isReadonly() : bool {
+        return (bool) ($this->flags & self::MODIFIER_READONLY);
+    }
+
     /**
      * Whether the class is anonymous.
      *
@@ -77,6 +81,27 @@ public function isAnonymous() : bool {
         return null === $this->name;
     }
 
+    /**
+     * @internal
+     */
+    public static function verifyClassModifier($a, $b) {
+        if ($a & self::MODIFIER_ABSTRACT && $b & self::MODIFIER_ABSTRACT) {
+            throw new Error('Multiple abstract modifiers are not allowed');
+        }
+
+        if ($a & self::MODIFIER_FINAL && $b & self::MODIFIER_FINAL) {
+            throw new Error('Multiple final modifiers are not allowed');
+        }
+
+        if ($a & self::MODIFIER_READONLY && $b & self::MODIFIER_READONLY) {
+            throw new Error('Multiple readonly modifiers are not allowed');
+        }
+
+        if ($a & 48 && $b & 48) {
+            throw new Error('Cannot use the final modifier on an abstract class');
+        }
+    }
+
     /**
      * @internal
      */

diff --git a/lib/PhpParser/Parser/Php7.php b/lib/PhpParser/Parser/Php7.php
diff --git a/lib/PhpParser/ParserAbstract.php b/lib/PhpParser/ParserAbstract.php
@@ -875,6 +875,15 @@ protected function createCommentNopAttributes(array $comments) {
         return $attributes;
     }
 
+    protected function checkClassModifier($a, $b, $modifierPos) {
+        try {
+            Class_::verifyClassModifier($a, $b);
+        } catch (Error $error) {
+            $error->setAttributes($this->getAttributesAt($modifierPos));
+            $this->emitError($error);
+        }
+    }
+
     protected function checkModifier($a, $b, $modifierPos) {
         // Jumping through some hoops here because verifyModifier() is also used elsewhere
         try {

diff --git a/test/PhpParser/Builder/ClassTest.php b/test/PhpParser/Builder/ClassTest.php
@@ -68,6 +68,20 @@ public function testFinal() {
         );
     }
 
+    public function testReadonly() {
+        $node = $this->createClassBuilder('Test')
+            ->makeReadonly()
+            ->getNode()
+        ;
+
+        $this->assertEquals(
+            new Stmt\Class_('Test', [
+                'flags' => Stmt\Class_::MODIFIER_READONLY
+            ]),
+            $node
+        );
+    }
+
     public function testStatementOrder() {
         $method = new Stmt\ClassMethod('testMethod');
         $property = new Stmt\Property(

diff --git a/test/code/parser/errorHandling/recovery.test b/test/code/parser/errorHandling/recovery.test
@@ -1521,4 +1521,4 @@ array(
             )
         )
     )
-)
+)
diff --git a/test/code/parser/stmt/class/constModifierErrors.test b/test/code/parser/stmt/class/constModifierErrors.test
@@ -150,4 +150,4 @@ array(
             )
         )
     )
-)
+)
diff --git a/test/code/parser/stmt/class/modifier.test b/test/code/parser/stmt/class/modifier.test
@@ -66,7 +66,7 @@ array(
     )
 )
 -----
-<?php class A { readonly readonly $a; }
+<?php class C { readonly readonly $a; }
 -----
 !!php7
 Multiple readonly modifiers are not allowed from 1:26 to 1:33
@@ -76,7 +76,7 @@ array(
         )
         flags: 0
         name: Identifier(
-            name: A
+            name: C
         )
         extends: null
         implements: array(
@@ -231,8 +231,29 @@ array(
 )
 -----
 <?php abstract final class A { }
+-----
+!!php7
+Cannot use the final modifier on an abstract class from 1:16 to 1:20
+array(
+    0: Stmt_Class(
+        attrGroups: array(
+        )
+        flags: MODIFIER_ABSTRACT | MODIFIER_FINAL (48)
+        name: Identifier(
+            name: A
+        )
+        extends: null
+        implements: array(
+        )
+        stmts: array(
+        )
+    )
+)
+-----
+<?php abstract final class A { }
 // Type in the partial parse could conceivably be any of 0, 16 or 32
 -----
+!!php5
 Syntax error, unexpected T_FINAL, expecting T_CLASS from 1:16 to 1:20
 array(
     0: Stmt_Class(
@@ -258,6 +279,7 @@ array(
 <?php readonly class A { }
 // Type in the partial parse could conceivably be any of 0, 16 or 32
 -----
+!!php5
 Syntax error, unexpected T_READONLY from 1:7 to 1:14
 array(
     0: Stmt_Class(
@@ -280,7 +302,7 @@ array(
     )
 )
 -----
-<?php class A { abstract $a; }
+<?php class B { abstract $b; }
 -----
 Properties cannot be declared abstract from 1:17 to 1:24
 array(
@@ -289,7 +311,7 @@ array(
         )
         flags: 0
         name: Identifier(
-            name: A
+            name: B
         )
         extends: null
         implements: array(
@@ -303,7 +325,7 @@ array(
                 props: array(
                     0: Stmt_PropertyProperty(
                         name: VarLikeIdentifier(
-                            name: a
+                            name: b
                         )
                         default: null
                     )

diff --git a/test/code/parser/stmt/class/readonly.test b/test/code/parser/stmt/class/readonly.test
@@ -0,0 +1,68 @@
+Readonly class
+-----
+<?php
+
+readonly class A {
+}
+-----
+!!php7
+array(
+    0: Stmt_Class(
+        attrGroups: array(
+        )
+        flags: MODIFIER_READONLY (64)
+        name: Identifier(
+            name: A
+        )
+        extends: null
+        implements: array(
+        )
+        stmts: array(
+        )
+    )
+)
+-----
+<?php
+
+readonly class A {
+}
+-----
+!!php5
+Syntax error, unexpected T_READONLY from 3:1 to 3:8
+array(
+    0: Stmt_Class(
+        attrGroups: array(
+        )
+        flags: 0
+        name: Identifier(
+            name: A
+        )
+        extends: null
+        implements: array(
+        )
+        stmts: array(
+        )
+    )
+)
+-----
+<?php
+
+final readonly class A {
+}
+-----
+!!php7
+array(
+    0: Stmt_Class(
+        attrGroups: array(
+        )
+        flags: MODIFIER_FINAL | MODIFIER_READONLY (96)
+        name: Identifier(
+            name: A
+        )
+        extends: null
+        implements: array(
+        )
+        stmts: array(
+        )
+    )
+)
diff --git a/test/code/prettyPrinter/stmt/readonly_class.test b/test/code/prettyPrinter/stmt/readonly_class.test
@@ -0,0 +1,12 @@
+Readonly class
+-----
+<?php
+
+readonly class Foo
+{
+}
+-----
+!!php7
+readonly class Foo
+{
+}