Add support for attributes on compile-time constants

Author: DanielEScherzer

Zend/tests/attributes/001_placement.phpt

@@ -25,6 +25,9 @@ $f2 = #[A1(9)] function () { };
 
 $f3 = #[A1(10)] fn () => 1;
 
+#[A1(11)]
+const CT_CONSTANT = 'Demo';
+
 $ref = new \ReflectionClass(Foo::class);
 
 $sources = [
@@ -37,7 +40,8 @@ $sources = [
     new \ReflectionObject($object),
     new \ReflectionFunction('f1'),
     new \ReflectionFunction($f2),
-    new \ReflectionFunction($f3)
+    new \ReflectionFunction($f3),
+    new \ReflectionConstant('CT_CONSTANT'),
 ];
 
 foreach ($sources as $r) {
@@ -132,3 +136,11 @@ array(1) {
   [0]=>
   int(10)
 }
+
+string(18) "ReflectionConstant"
+int(1)
+string(2) "A1"
+array(1) {
+  [0]=>
+  int(11)
+}

Zend/tests/attributes/029_reflect_internal_symbols.phpt

@@ -18,6 +18,9 @@ var_dump($rcc->getAttributes());
 $rp = new ReflectionProperty('Exception', 'message');
 var_dump($rp->getAttributes());
 
+$rct = new ReflectionConstant('PHP_VERSION');
+var_dump($rct->getAttributes());
+
 ?>
 --EXPECT--
 array(0) {
@@ -30,3 +33,5 @@ array(0) {
 }
 array(0) {
 }
+array(0) {
+}

Zend/tests/attributes/034_multiple_constants_error.phpt

@@ -0,0 +1,12 @@
+--TEST--
+Error trying to add attributes to multiple constants at once
+--FILE--
+<?php
+
+#[\Foo]
+const First = 1,
+    Second = 2;
+
+?>
+--EXPECTF--
+Fatal error: Cannot apply attributes to multiple constants at once in %s on line %d

Zend/tests/attributes/deprecated/constants/const_messages.phpt

@@ -0,0 +1,42 @@
+--TEST--
+#[\Deprecated]: Messages on compile time constants.
+--FILE--
+<?php
+
+#[\Deprecated]
+const DeprecatedConst1 = 1;
+
+#[\Deprecated("use DEPRECATED_CONST_2")]
+const DeprecatedConst2 = 2;
+
+#[\Deprecated(message: "use DEPRECATED_CONST_3")]
+const DeprecatedConst3 = 3;
+
+#[\Deprecated(message: "use DEPRECATED_CONST_4", since: "1.0")]
+const DeprecatedConst4 = 4;
+
+#[\Deprecated(since: "1.0")]
+const DeprecatedConst5 = 5;
+
+echo DeprecatedConst1 . "\n";
+echo DeprecatedConst2 . "\n";
+echo DeprecatedConst3 . "\n";
+echo DeprecatedConst4 . "\n";
+echo DeprecatedConst5 . "\n";
+?>
+--EXPECTF--
+Deprecated: Constant DeprecatedConst1 is deprecated in %s on line %d
+1
+
+Deprecated: Constant DeprecatedConst2 is deprecated, use DEPRECATED_CONST_2 in %s on line %d
+2
+
+Deprecated: Constant DeprecatedConst3 is deprecated, use DEPRECATED_CONST_3 in %s on line %d
+3
+
+Deprecated: Constant DeprecatedConst4 is deprecated since 1.0, use DEPRECATED_CONST_4 in %s on line %d
+4
+
+Deprecated: Constant DeprecatedConst5 is deprecated since 1.0 in %s on line %d
+5
+

Zend/zend_ast.c

@@ -2707,6 +2707,9 @@ zend_ast * ZEND_FASTCALL zend_ast_with_attributes(zend_ast *ast, zend_ast *attr)
 	case ZEND_AST_CLASS_CONST_GROUP:
 		ast->child[1] = attr;
 		break;
+	case ZEND_AST_CONST_DECL:
+		zend_ast_list_add(ast, attr);
+		break;
 	EMPTY_SWITCH_DEFAULT_CASE()
 	}
 

Zend/zend_attributes.c

@@ -354,7 +354,8 @@ static const char *target_names[] = {
 	"method",
 	"property",
 	"class constant",
-	"parameter"
+	"parameter",
+	"constant"
 };
 
 ZEND_API zend_string *zend_get_attribute_target_names(uint32_t flags)

Zend/zend_attributes.h

@@ -28,9 +28,10 @@
 #define ZEND_ATTRIBUTE_TARGET_PROPERTY		(1<<3)
 #define ZEND_ATTRIBUTE_TARGET_CLASS_CONST	(1<<4)
 #define ZEND_ATTRIBUTE_TARGET_PARAMETER		(1<<5)
-#define ZEND_ATTRIBUTE_TARGET_ALL			((1<<6) - 1)
-#define ZEND_ATTRIBUTE_IS_REPEATABLE		(1<<6)
-#define ZEND_ATTRIBUTE_FLAGS				((1<<7) - 1)
+#define ZEND_ATTRIBUTE_TARGET_CONST			(1<<6)
+#define ZEND_ATTRIBUTE_TARGET_ALL			((1<<7) - 1)
+#define ZEND_ATTRIBUTE_IS_REPEATABLE		(1<<7)
+#define ZEND_ATTRIBUTE_FLAGS				((1<<8) - 1)
 
 /* Flags for zend_attribute.flags */
 #define ZEND_ATTRIBUTE_PERSISTENT   (1<<0)

Zend/zend_attributes.stub.php

@@ -17,6 +17,8 @@ final class Attribute
     const int TARGET_CLASS_CONSTANT = UNKNOWN;
     /** @cvalue ZEND_ATTRIBUTE_TARGET_PARAMETER */
     const int TARGET_PARAMETER = UNKNOWN;
+    /** @cvalue ZEND_ATTRIBUTE_TARGET_CONST */
+    const int TARGET_CONSTANT = UNKNOWN;
     /** @cvalue ZEND_ATTRIBUTE_TARGET_ALL */
     const int TARGET_ALL = UNKNOWN;
     /**  @cvalue ZEND_ATTRIBUTE_IS_REPEATABLE */
@@ -75,7 +77,7 @@ public function __construct() {}
 /**
  * @strict-properties
  */
-#[Attribute(Attribute::TARGET_METHOD|Attribute::TARGET_FUNCTION|Attribute::TARGET_CLASS_CONSTANT)]
+#[Attribute(Attribute::TARGET_METHOD|Attribute::TARGET_FUNCTION|Attribute::TARGET_CLASS_CONSTANT|Attribute::TARGET_CONSTANT)]
 final class Deprecated
 {
     public readonly ?string $message;

Zend/zend_attributes_arginfo.h

@@ -9415,8 +9415,14 @@ static void zend_compile_const_decl(zend_ast *ast) /* {{{ */
 {
 	zend_ast_list *list = zend_ast_get_list(ast);
 	uint32_t i;
+	zend_ast *attributes_ast = NULL;
+	zend_op *last_op = NULL;
 	for (i = 0; i < list->children; ++i) {
 		zend_ast *const_ast = list->child[i];
+		if (i == list->children - 1 && const_ast->kind == ZEND_AST_ATTRIBUTE_LIST) {
+			attributes_ast = const_ast;
+			continue;
+		}
 		zend_ast *name_ast = const_ast->child[0];
 		zend_ast **value_ast_ptr = &const_ast->child[1];
 		zend_string *unqualified_name = zend_ast_get_str(name_ast);
@@ -9447,10 +9453,30 @@ static void zend_compile_const_decl(zend_ast *ast) /* {{{ */
 		name_node.op_type = IS_CONST;
 		ZVAL_STR(&name_node.u.constant, name);
 
-		zend_emit_op(NULL, ZEND_DECLARE_CONST, &name_node, &value_node);
+		last_op = zend_emit_op(NULL, ZEND_DECLARE_CONST, &name_node, &value_node);
 
 		zend_register_seen_symbol(name, ZEND_SYMBOL_CONST);
 	}
+	if (attributes_ast == NULL) {
+		return;
+	}
+	// Validate: attributes can only be applied to one constant at a time
+	// Since we store the AST for the attributes in the list of children,
+	// there should be exactly 2 children
+	if (list->children > 2) {
+		zend_error_noreturn(
+			E_COMPILE_ERROR,
+			"Cannot apply attributes to multiple constants at once"
+		);
+	}
+	ZEND_ASSERT(last_op != NULL);
+	last_op->opcode = ZEND_DECLARE_ATTRIBUTED_CONST;
+	HashTable *attribs_ht = NULL;
+	zend_compile_attributes(&attribs_ht, list->child[1], 0, ZEND_ATTRIBUTE_TARGET_CONST, 0);
+	znode attribs_node;
+	attribs_node.op_type = IS_CONST;
+	ZVAL_PTR(&attribs_node.u.constant, attribs_ht);
+	zend_emit_op_data(&attribs_node);
 }
 /* }}}*/