Add support for attributes on constants

grammar/php.y

@@ -257,7 +257,10 @@ top_statement:
     | T_USE use_declarations semi                           { $$ = Stmt\Use_[$2, Stmt\Use_::TYPE_NORMAL]; }
     | T_USE use_type use_declarations semi                  { $$ = Stmt\Use_[$3, $2]; }
     | group_use_declaration
-    | T_CONST constant_declaration_list semi                { $$ = Stmt\Const_[$2]; }
+    | T_CONST constant_declaration_list semi                { $$ = new Stmt\Const_($2, attributes(), []); }
+    | attributes T_CONST constant_declaration_list semi
+          { $$ = new Stmt\Const_($3, attributes(), $1);
+            $this->checkConstantAttributes($$); }
 ;
 
 use_type:

lib/PhpParser/Node/Stmt/Const_.php

@@ -7,20 +7,28 @@
 class Const_ extends Node\Stmt {
     /** @var Node\Const_[] Constant declarations */
     public array $consts;
+    /** @var Node\AttributeGroup[] PHP attribute groups */
+    public array $attrGroups;
 
     /**
      * Constructs a const list node.
      *
      * @param Node\Const_[] $consts Constant declarations
      * @param array<string, mixed> $attributes Additional attributes
+     * @param list<Node\AttributeGroup> $attrGroups PHP attribute groups
      */
-    public function __construct(array $consts, array $attributes = []) {
+    public function __construct(
+        array $consts,
+        array $attributes = [],
+        array $attrGroups = []
+    ) {
         $this->attributes = $attributes;
+        $this->attrGroups = $attrGroups;
         $this->consts = $consts;
     }
 
     public function getSubNodeNames(): array {
-        return ['consts'];
+        return ['attrGroups', 'consts'];
     }
 
     public function getType(): string {

lib/PhpParser/NodeVisitor/NameResolver.php

@@ -120,6 +120,7 @@ public function enterNode(Node $node) {
             foreach ($node->consts as $const) {
                 $this->addNamespacedName($const);
             }
+            $this->resolveAttrGroups($node);
         } elseif ($node instanceof Stmt\ClassConst) {
             if (null !== $node->type) {
                 $node->type = $this->resolveType($node->type);

lib/PhpParser/ParserAbstract.php

@@ -23,6 +23,7 @@
 use PhpParser\Node\Stmt\Class_;
 use PhpParser\Node\Stmt\ClassConst;
 use PhpParser\Node\Stmt\ClassMethod;
+use PhpParser\Node\Stmt\Const_;
 use PhpParser\Node\Stmt\Else_;
 use PhpParser\Node\Stmt\ElseIf_;
 use PhpParser\Node\Stmt\Enum_;
@@ -1202,6 +1203,13 @@ protected function checkPropertyHookModifiers(int $a, int $b, int $modifierPos):
         }
     }
 
+    protected function checkConstantAttributes(Const_ $node): void {
+        if ($node->attrGroups !== [] && count($node->consts) > 1) {
+            $this->emitError(new Error(
+                'Cannot use attributes on multiple constants at once', $node->getAttributes()));
+        }
+    }
+
     /**
      * @param Property|Param $node
      */

lib/PhpParser/PrettyPrinter/Standard.php

@@ -878,7 +878,9 @@ protected function pStmt_Function(Stmt\Function_ $node): string {
     }
 
     protected function pStmt_Const(Stmt\Const_ $node): string {
-        return 'const ' . $this->pCommaSeparated($node->consts) . ';';
+        return $this->pAttrGroups($node->attrGroups)
+            . 'const '
+            . $this->pCommaSeparated($node->consts) . ';';
     }
 
     protected function pStmt_Declare(Stmt\Declare_ $node): string {

lib/PhpParser/PrettyPrinterAbstract.php

@@ -1634,6 +1634,7 @@ protected function initializeEmptyListInsertionMap(): void {
             Stmt\Trait_::class . '->attrGroups' => [null, '', "\n"],
             Expr\ArrowFunction::class . '->attrGroups' => [null, '', ' '],
             Expr\Closure::class . '->attrGroups' => [null, '', ' '],
+            Stmt\Const_::class . '->attrGroups' => [null, '', "\n"],
             PrintableNewAnonClassNode::class . '->attrGroups' => [\T_NEW, ' ', ''],
 
             /* These cannot be empty to start with:

test/PhpParser/NodeVisitor/NameResolverTest.php

@@ -245,6 +245,9 @@ function(A $a) : A {};
 fn(A $a): A => $a;
 fn(?A $a): ?A => $a;
 
+#[X]
+const EXAMPLE = true;
+
 A::b();
 A::$b;
 A::B;
@@ -338,6 +341,8 @@ function fn4(?array $a): ?array
 #[\NS\X] fn(array $a): array => $a;
 fn(\NS\A $a): \NS\A => $a;
 fn(?\NS\A $a): ?\NS\A => $a;
+#[\NS\X]
+const EXAMPLE = true;
 \NS\A::b();
 \NS\A::$b;
 \NS\A::B;

test/code/formatPreservation/constants.test

@@ -0,0 +1,50 @@
+Constants
+-----
+<?php
+
+const FOO = true;
+
+#[A]
+const BAR = true;
+-----
+$attrGroup = new Node\AttributeGroup([
+    new Node\Attribute(new Node\Name('B'), []),
+]);
+$stmts[0]->attrGroups[] = $attrGroup;
+$stmts[1]->attrGroups[] = $attrGroup;
+-----
+<?php
+
+#[B]
+const FOO = true;
+
+#[A]
+#[B]
+const BAR = true;
+-----
+<?php
+
+#[ A,   B]
+const FOO = true;
+
+#[
+    A,
+    B,
+]
+const BAR = true;
+-----
+$attr = new Node\Attribute(new Node\Name('C'), []);
+$stmts[0]->attrGroups[0]->attrs[] = $attr;
+$stmts[1]->attrGroups[0]->attrs[] = $attr;
+-----
+<?php
+
+#[ A,   B, C]
+const FOO = true;
+
+#[
+    A,
+    B,
+    C,
+]
+const BAR = true;

test/code/parser/errorHandling/recovery.test

@@ -476,6 +476,8 @@ array(
                 )
             )
             3: Stmt_Const(
+                attrGroups: array(
+                )
                 consts: array(
                     0: Const(
                         name: Identifier(
@@ -629,6 +631,8 @@ array(
         )
     )
     3: Stmt_Const(
+        attrGroups: array(
+        )
         consts: array(
             0: Const(
                 name: Identifier(