refactor: class constants parsing

As part of my work on typed class constants, I wanted to make a
separate pull request for unrelated changes.

These include:

 * Moving from ast->child[0]->attr to ast->attr
 * Making zend_ast_export_ex() export class constants' visibility
 * Extracting an additional zend_compile_class_const_group() function

Closes GH-5812.

Author: moliata

Zend/tests/assert/expect_015.phpt

@@ -164,8 +164,8 @@ Warning: assert(): assert(0 && ($a = function () {
 
 Warning: assert(): assert(0 && ($a = function &(array &$a, ?X $b = null) use($c, &$d): ?X {
     abstract class A extends B implements C, D {
-        const X = 12;
-        const Y = self::X, Z = 'aaa';
+        public const X = 12;
+        public const Y = self::X, Z = 'aaa';
         public $a = 1, $b;
         protected $c;
         private static $d = null;

Zend/tests/attributes/012_ast_export.phpt

@@ -29,7 +29,7 @@ Warning: assert(): assert(0 && ($a = <<A1(1, 2, 1 + 2)>> fn() => 1)) failed in %
 Warning: assert(): assert(0 && ($a = new <<A1>> class {
     <<A1>>
     <<A2>>
-    const FOO = 'foo';
+    public const FOO = 'foo';
     <<A2>>
     public $x;
     <<A3>>

Zend/zend_ast.c

@@ -1381,6 +1381,16 @@ static ZEND_COLD void zend_ast_export_attributes(smart_str *str, zend_ast *ast,
 	}
 }
 
+static ZEND_COLD void zend_ast_export_visibility(smart_str *str, uint32_t flags) {
+	if (flags & ZEND_ACC_PUBLIC) {
+		smart_str_appends(str, "public ");
+	} else if (flags & ZEND_ACC_PROTECTED) {
+		smart_str_appends(str, "protected ");
+	} else if (flags & ZEND_ACC_PRIVATE) {
+		smart_str_appends(str, "private ");
+	}
+}
+
 static ZEND_COLD void zend_ast_export_type(smart_str *str, zend_ast *ast, int indent) {
 	if (ast->kind == ZEND_AST_TYPE_UNION) {
 		zend_ast_list *list = zend_ast_get_list(ast);
@@ -1478,13 +1488,9 @@ static ZEND_COLD void zend_ast_export_ex(smart_str *str, zend_ast *ast, int prio
 				zend_bool newlines = !(ast->kind == ZEND_AST_CLOSURE || ast->kind == ZEND_AST_ARROW_FUNC);
 				zend_ast_export_attributes(str, decl->child[4], indent, newlines);
 			}
-			if (decl->flags & ZEND_ACC_PUBLIC) {
-				smart_str_appends(str, "public ");
-			} else if (decl->flags & ZEND_ACC_PROTECTED) {
-				smart_str_appends(str, "protected ");
-			} else if (decl->flags & ZEND_ACC_PRIVATE) {
-				smart_str_appends(str, "private ");
-			}
+
+			zend_ast_export_visibility(str, decl->flags);
+
 			if (decl->flags & ZEND_ACC_STATIC) {
 				smart_str_appends(str, "static ");
 			}
@@ -1595,13 +1601,9 @@ static ZEND_COLD void zend_ast_export_ex(smart_str *str, zend_ast *ast, int prio
 			if (ast->child[2]) {
 				zend_ast_export_attributes(str, ast->child[2], indent, 1);
 			}
-			if (ast->attr & ZEND_ACC_PUBLIC) {
-				smart_str_appends(str, "public ");
-			} else if (ast->attr & ZEND_ACC_PROTECTED) {
-				smart_str_appends(str, "protected ");
-			} else if (ast->attr & ZEND_ACC_PRIVATE) {
-				smart_str_appends(str, "private ");
-			}
+
+			zend_ast_export_visibility(str, ast->attr);
+
 			if (ast->attr & ZEND_ACC_STATIC) {
 				smart_str_appends(str, "static ");
 			}
@@ -1616,15 +1618,19 @@ static ZEND_COLD void zend_ast_export_ex(smart_str *str, zend_ast *ast, int prio
 		}
 
 		case ZEND_AST_CONST_DECL:
-		case ZEND_AST_CLASS_CONST_DECL:
 			smart_str_appends(str, "const ");
 			goto simple_list;
 		case ZEND_AST_CLASS_CONST_GROUP:
 			if (ast->child[1]) {
 				zend_ast_export_attributes(str, ast->child[1], indent, 1);
 			}
-			zend_ast_export_ex(str, ast->child[0], 0, indent);
-			break;
+
+			zend_ast_export_visibility(str, ast->attr);
+			smart_str_appends(str, "const ");
+
+			ast = ast->child[0];
+
+			goto simple_list;
 		case ZEND_AST_NAME_LIST:
 			zend_ast_export_name_list(str, (zend_ast_list*)ast, indent);
 			break;

Zend/zend_compile.c

@@ -6613,18 +6613,18 @@ void zend_compile_prop_decl(zend_ast *ast, zend_ast *type_ast, uint32_t flags, z
 }
 /* }}} */
 
-void zend_compile_prop_group(zend_ast *list) /* {{{ */
+void zend_compile_prop_group(zend_ast *ast) /* {{{ */
 {
-	zend_ast *type_ast = list->child[0];
-	zend_ast *prop_ast = list->child[1];
-	zend_ast *attr_ast = list->child[2];
+	zend_ast *type_ast = ast->child[0];
+	zend_ast *prop_ast = ast->child[1];
+	zend_ast *attr_ast = ast->child[2];
 
 	if (attr_ast && zend_ast_get_list(prop_ast)->children > 1) {
 		zend_error_noreturn(E_COMPILE_ERROR, "Cannot apply attributes to a group of properties");
 		return;
 	}
 
-	zend_compile_prop_decl(prop_ast, type_ast, list->attr, attr_ast);
+	zend_compile_prop_decl(prop_ast, type_ast, ast->attr, attr_ast);
 }
 /* }}} */
 
@@ -6640,23 +6640,18 @@ static void zend_check_const_and_trait_alias_attr(uint32_t attr, const char* ent
 }
 /* }}} */
 
-void zend_compile_class_const_decl(zend_ast *ast, zend_ast *attr_ast) /* {{{ */
+void zend_compile_class_const_decl(zend_ast *ast, uint32_t flags, zend_ast *attr_ast) /* {{{ */
 {
 	zend_ast_list *list = zend_ast_get_list(ast);
 	zend_class_entry *ce = CG(active_class_entry);
-	uint32_t i;
+	uint32_t i, children = list->children;
 
 	if ((ce->ce_flags & ZEND_ACC_TRAIT) != 0) {
 		zend_error_noreturn(E_COMPILE_ERROR, "Traits cannot have constants");
 		return;
 	}
 
-	if (attr_ast && list->children > 1) {
-		zend_error_noreturn(E_COMPILE_ERROR, "Cannot apply attributes to a group of constants");
-		return;
-	}
-
-	for (i = 0; i < list->children; ++i) {
+	for (i = 0; i < children; ++i) {
 		zend_class_constant *c;
 		zend_ast *const_ast = list->child[i];
 		zend_ast *name_ast = const_ast->child[0];
@@ -6666,12 +6661,12 @@ void zend_compile_class_const_decl(zend_ast *ast, zend_ast *attr_ast) /* {{{ */
 		zend_string *doc_comment = doc_comment_ast ? zend_string_copy(zend_ast_get_str(doc_comment_ast)) : NULL;
 		zval value_zv;
 
-		if (UNEXPECTED(ast->attr & (ZEND_ACC_STATIC|ZEND_ACC_ABSTRACT|ZEND_ACC_FINAL))) {
-			zend_check_const_and_trait_alias_attr(ast->attr, "constant");
+		if (UNEXPECTED(flags & (ZEND_ACC_STATIC|ZEND_ACC_ABSTRACT|ZEND_ACC_FINAL))) {
+			zend_check_const_and_trait_alias_attr(flags, "constant");
 		}
 
 		zend_const_expr_to_zval(&value_zv, value_ast);
-		c = zend_declare_class_constant_ex(ce, name, &value_zv, ast->attr, doc_comment);
+		c = zend_declare_class_constant_ex(ce, name, &value_zv, flags, doc_comment);
 
 		if (attr_ast) {
 			zend_compile_attributes(&c->attributes, attr_ast, 0, ZEND_ATTRIBUTE_TARGET_CLASS_CONST);
@@ -6680,6 +6675,21 @@ void zend_compile_class_const_decl(zend_ast *ast, zend_ast *attr_ast) /* {{{ */
 }
 /* }}} */
 
+void zend_compile_class_const_group(zend_ast *ast) /* {{{ */
+{
+	zend_ast *const_ast = ast->child[0];
+	zend_ast *attr_ast = ast->child[1];
+
+	if (attr_ast && zend_ast_get_list(const_ast)->children > 1) {
+		zend_error_noreturn(E_COMPILE_ERROR, "Cannot apply attributes to a group of constants");
+
+		return;
+	}
+
+	zend_compile_class_const_decl(const_ast, ast->attr, attr_ast);
+}
+/* }}} */
+
 static void zend_compile_method_ref(zend_ast *ast, zend_trait_method_reference *method_ref) /* {{{ */
 {
 	zend_ast *class_ast = ast->child[0];
@@ -8983,7 +8993,7 @@ void zend_compile_stmt(zend_ast *ast) /* {{{ */
 			zend_compile_prop_group(ast);
 			break;
 		case ZEND_AST_CLASS_CONST_GROUP:
-			zend_compile_class_const_decl(ast->child[0], ast->child[1]);
+			zend_compile_class_const_group(ast);
 			break;
 		case ZEND_AST_USE_TRAIT:
 			zend_compile_use_trait(ast);

Zend/zend_language_parser.y

@@ -797,7 +797,8 @@ attributed_class_statement:
 			{ $$ = zend_ast_create(ZEND_AST_PROP_GROUP, $2, $3, NULL);
 			  $$->attr = $1; }
 	|	method_modifiers T_CONST class_const_list ';'
-			{ $$ = zend_ast_create(ZEND_AST_CLASS_CONST_GROUP, $3, NULL); $3->attr = $1; }
+			{ $$ = zend_ast_create(ZEND_AST_CLASS_CONST_GROUP, $3, NULL);
+			  $$->attr = $1; }
 	|	method_modifiers function returns_ref identifier backup_doc_comment '(' parameter_list ')'
 		return_type backup_fn_flags method_body backup_fn_flags
 			{ $$ = zend_ast_create_decl(ZEND_AST_METHOD, $3 | $1 | $12, $2, $5,