Support readonly before DNF type

This makes us match the PHP 8.2 handling of readonly. Handling of
"readonly" functions is moved to the parser to allow distinguishing
them from readonly properties with DNF types. We have to uglify the
grammar to avoid some shift/reduce conflicts. Thank you WordPress.

grammar/php.y

@@ -468,15 +468,23 @@ block_or_error:
     | error                                                 { $$ = []; }
 ;
 
+identifier_maybe_readonly:
+      identifier_not_reserved                               { $$ = $1; }
+    | T_READONLY                                            { $$ = Node\Identifier[$1]; }
+;
+
 function_declaration_statement:
-      T_FUNCTION optional_ref identifier_not_reserved '(' parameter_list ')' optional_return_type block_or_error
+      T_FUNCTION optional_ref identifier_maybe_readonly '(' parameter_list ')' optional_return_type block_or_error
           { $$ = Stmt\Function_[$3, ['byRef' => $2, 'params' => $5, 'returnType' => $7, 'stmts' => $8, 'attrGroups' => []]]; }
-    | attributes T_FUNCTION optional_ref identifier_not_reserved '(' parameter_list ')' optional_return_type block_or_error
+    | attributes T_FUNCTION optional_ref identifier_maybe_readonly '(' parameter_list ')' optional_return_type block_or_error
           { $$ = Stmt\Function_[$4, ['byRef' => $3, 'params' => $6, 'returnType' => $8, 'stmts' => $9, 'attrGroups' => $1]]; }
 ;
 
 class_declaration_statement:
-      optional_attributes class_entry_type identifier_not_reserved extends_from implements_list '{' class_statement_list '}'
+      class_entry_type identifier_not_reserved extends_from implements_list '{' class_statement_list '}'
+          { $$ = Stmt\Class_[$2, ['type' => $1, 'extends' => $3, 'implements' => $4, 'stmts' => $6, 'attrGroups' => []]];
+            $this->checkClass($$, #2); }
+    | attributes class_entry_type identifier_not_reserved extends_from implements_list '{' class_statement_list '}'
           { $$ = Stmt\Class_[$3, ['type' => $2, 'extends' => $4, 'implements' => $5, 'stmts' => $7, 'attrGroups' => $1]];
             $this->checkClass($$, #3); }
     | optional_attributes T_INTERFACE identifier_not_reserved interface_extends_list '{' class_statement_list '}'
@@ -1090,8 +1098,13 @@ lexical_var:
       optional_ref plain_variable                           { $$ = Node\ClosureUse[$2, $1]; }
 ;
 
+name_readonly:
+      T_READONLY                                            { $$ = Name[$1]; }
+;
+
 function_call:
       name argument_list                                    { $$ = Expr\FuncCall[$1, $2]; }
+    | name_readonly argument_list                           { $$ = Expr\FuncCall[$1, $2]; }
     | callable_expr argument_list                           { $$ = Expr\FuncCall[$1, $2]; }
     | class_name_or_var T_PAAMAYIM_NEKUDOTAYIM member_name argument_list
           { $$ = Expr\StaticCall[$1, $3, $4]; }

lib/PhpParser/Lexer/Emulative.php

@@ -14,6 +14,7 @@
 use PhpParser\Lexer\TokenEmulator\MatchTokenEmulator;
 use PhpParser\Lexer\TokenEmulator\NullsafeTokenEmulator;
 use PhpParser\Lexer\TokenEmulator\NumericLiteralSeparatorEmulator;
+use PhpParser\Lexer\TokenEmulator\ReadonlyFunctionTokenEmulator;
 use PhpParser\Lexer\TokenEmulator\ReadonlyTokenEmulator;
 use PhpParser\Lexer\TokenEmulator\ReverseEmulator;
 use PhpParser\Lexer\TokenEmulator\TokenEmulator;
@@ -58,6 +59,7 @@ public function __construct(array $options = []) {
             new EnumTokenEmulator(),
             new ReadonlyTokenEmulator(),
             new ExplicitOctalEmulator(),
+            new ReadonlyFunctionTokenEmulator(),
         ];
 
         // Collect emulators that are relevant for the PHP version we're running

lib/PhpParser/Lexer/TokenEmulator/ReadonlyFunctionTokenEmulator.php

@@ -0,0 +1,31 @@
+<?php declare(strict_types=1);
+
+namespace PhpParser\Lexer\TokenEmulator;
+
+use PhpParser\PhpVersion;
+
+/*
+ * In PHP 8.1, "readonly(" was special cased in the lexer in order to support functions with
+ * name readonly. In PHP 8.2, this may conflict with readonly properties having a DNF type. For
+ * this reason, PHP 8.2 instead treats this as T_READONLY and then handles it specially in the
+ * parser. This emulator only exists to handle this special case, which is skipped by the
+ * PHP 8.1 ReadonlyTokenEmulator.
+ */
+class ReadonlyFunctionTokenEmulator extends KeywordEmulator {
+    public function getKeywordString(): string {
+        return 'readonly';
+    }
+
+    public function getKeywordToken(): int {
+        return \T_READONLY;
+    }
+
+    public function getPhpVersion(): PhpVersion {
+        return PhpVersion::fromComponents(8, 2);
+    }
+
+    public function reverseEmulate(string $code, array $tokens): array {
+        // Don't bother
+        return $tokens;
+    }
+}

test/PhpParser/Lexer/EmulativeTest.php

@@ -360,12 +360,12 @@ public function provideTestLexNewFeatures() {
             ]],
             ['function readonly(', [
                 [\T_FUNCTION, 'function'],
-                [\T_STRING, 'readonly'],
+                [\T_READONLY, 'readonly'],
                 [ord('('), '('],
             ]],
             ['function readonly (', [
                 [\T_FUNCTION, 'function'],
-                [\T_STRING, 'readonly'],
+                [\T_READONLY, 'readonly'],
                 [ord('('), '('],
             ]],
         ];

test/code/parser/stmt/function/disjointNormalFormTypes.test

@@ -4,6 +4,7 @@ DNF types
 
 class Test {
     public (A&B)|(X&Y) $prop;
+    public readonly (A&B)|C $prop2;
 }
 
 function test((A&B)|(X&Y) $a): (A&B)|(X&Y) {}
@@ -65,6 +66,42 @@ array(
                     )
                 )
             )
+            1: Stmt_Property(
+                attrGroups: array(
+                )
+                flags: PUBLIC | READONLY (65)
+                type: UnionType(
+                    types: array(
+                        0: IntersectionType(
+                            types: array(
+                                0: Name(
+                                    parts: array(
+                                        0: A
+                                    )
+                                )
+                                1: Name(
+                                    parts: array(
+                                        0: B
+                                    )
+                                )
+                            )
+                        )
+                        1: Name(
+                            parts: array(
+                                0: C
+                            )
+                        )
+                    )
+                )
+                props: array(
+                    0: PropertyItem(
+                        name: VarLikeIdentifier(
+                            name: prop2
+                        )
+                        default: null
+                    )
+                )
+            )
         )
     )
     1: Stmt_Function(

test/code/parser/stmt/function/readonlyFunction.test

@@ -0,0 +1,32 @@
+readonly function
+-----
+<?php
+function readonly() {}
+readonly();
+-----
+array(
+    0: Stmt_Function(
+        attrGroups: array(
+        )
+        byRef: false
+        name: Identifier(
+            name: readonly
+        )
+        params: array(
+        )
+        returnType: null
+        stmts: array(
+        )
+    )
+    1: Stmt_Expression(
+        expr: Expr_FuncCall(
+            name: Name(
+                parts: array(
+                    0: readonly
+                )
+            )
+            args: array(
+            )
+        )
+    )
+)