Add assertions verifying that zend_ast_decl AST nodes are not treated as regular zend_ast nodes (php#17390)

* zend_compile: Do not traverse children of ZEND_AST_CLOSURE in zend_compile_const_expr()

* Add assertions verifying that zend_ast_decl AST nodes are not treated as regular zend_ast nodes

Author: TimWolla

Zend/zend_ast.c

@@ -1088,6 +1088,9 @@ static size_t ZEND_FASTCALL zend_ast_tree_size(zend_ast *ast)
 				size += zend_ast_tree_size(list->child[i]);
 			}
 		}
+	} else if (zend_ast_is_decl(ast)) {
+		/* Not implemented. */
+		ZEND_UNREACHABLE();
 	} else {
 		uint32_t i, children = zend_ast_get_num_children(ast);
 
@@ -1141,6 +1144,9 @@ static void* ZEND_FASTCALL zend_ast_tree_copy(zend_ast *ast, void *buf)
 		ZVAL_COPY(&new->val, &((zend_ast_zval *) ast)->val);
 		Z_LINENO(new->val) = zend_ast_get_lineno(ast);
 		buf = (void*)((char*)buf + sizeof(zend_ast_zval));
+	} else if (zend_ast_is_decl(ast)) {
+		/* Not implemented. */
+		ZEND_UNREACHABLE();
 	} else {
 		uint32_t i, children = zend_ast_get_num_children(ast);
 		zend_ast *new = (zend_ast*)buf;
@@ -1206,7 +1212,7 @@ ZEND_API void ZEND_FASTCALL zend_ast_destroy(zend_ast *ast)
 		zend_string_release_ex(zend_ast_get_constant_name(ast), 0);
 	} else if (EXPECTED(ast->kind == ZEND_AST_OP_ARRAY)) {
 		ZEND_ASSERT(!Z_REFCOUNTED(((zend_ast_zval*)(ast))->val));
-	} else if (EXPECTED(ast->kind >= ZEND_AST_FUNC_DECL)) {
+	} else if (EXPECTED(zend_ast_is_decl(ast))) {
 		zend_ast_decl *decl = (zend_ast_decl *) ast;
 
 		if (decl->name) {
@@ -1237,6 +1243,9 @@ ZEND_API void zend_ast_apply(zend_ast *ast, zend_ast_apply_func fn, void *contex
 		for (i = 0; i < list->children; ++i) {
 			fn(&list->child[i], context);
 		}
+	} else if (zend_ast_is_decl(ast)) {
+		/* Not implemented. */
+		ZEND_UNREACHABLE();
 	} else {
 		uint32_t i, children = zend_ast_get_num_children(ast);
 		for (i = 0; i < children; ++i) {

Zend/zend_ast.h

@@ -331,6 +331,10 @@ static zend_always_inline bool zend_ast_is_special(zend_ast *ast) {
 	return (ast->kind >> ZEND_AST_SPECIAL_SHIFT) & 1;
 }
 
+static zend_always_inline bool zend_ast_is_decl(zend_ast *ast) {
+	return zend_ast_is_special(ast) && ast->kind >= ZEND_AST_FUNC_DECL;
+}
+
 static zend_always_inline bool zend_ast_is_list(zend_ast *ast) {
 	return (ast->kind >> ZEND_AST_IS_LIST_SHIFT) & 1;
 }
@@ -357,6 +361,8 @@ static zend_always_inline zend_string *zend_ast_get_constant_name(zend_ast *ast)
 
 static zend_always_inline uint32_t zend_ast_get_num_children(zend_ast *ast) {
 	ZEND_ASSERT(!zend_ast_is_list(ast));
+	ZEND_ASSERT(!zend_ast_is_special(ast));
+
 	return ast->kind >> ZEND_AST_NUM_CHILDREN_SHIFT;
 }
 static zend_always_inline uint32_t zend_ast_get_lineno(zend_ast *ast) {

Zend/zend_compile.c

@@ -11293,7 +11293,8 @@ static void zend_compile_const_expr(zend_ast **ast_ptr, void *context) /* {{{ */
 			break;
 		case ZEND_AST_CLOSURE:
 			zend_compile_const_expr_closure(ast_ptr);
-			break;
+			/* Return, because we do not want to traverse the children. */
+			return;
 	}
 
 	zend_ast_apply(ast, zend_compile_const_expr, context);

ext/opcache/zend_file_cache.c

@@ -366,6 +366,9 @@ static void zend_file_cache_serialize_ast(zend_ast                 *ast,
 	} else if (ast->kind == ZEND_AST_OP_ARRAY) {
 		/* The op_array itself will be serialized as part of the dynamic_func_defs. */
 		SERIALIZE_PTR(Z_PTR(((zend_ast_zval*)ast)->val));
+	} else if (zend_ast_is_decl(ast)) {
+		/* Not implemented. */
+		ZEND_UNREACHABLE();
 	} else {
 		uint32_t children = zend_ast_get_num_children(ast);
 		for (i = 0; i < children; i++) {
@@ -1248,6 +1251,9 @@ static void zend_file_cache_unserialize_ast(zend_ast                *ast,
 	} else if (ast->kind == ZEND_AST_OP_ARRAY) {
 		/* The op_array itself will be unserialized as part of the dynamic_func_defs. */
 		UNSERIALIZE_PTR(Z_PTR(((zend_ast_zval*)ast)->val));
+	} else if (zend_ast_is_decl(ast)) {
+		/* Not implemented. */
+		ZEND_UNREACHABLE();
 	} else {
 		uint32_t children = zend_ast_get_num_children(ast);
 		for (i = 0; i < children; i++) {

ext/opcache/zend_persist.c

@@ -192,6 +192,9 @@ static zend_ast *zend_persist_ast(zend_ast *ast)
 		zend_ast_zval *copy = zend_shared_memdup(ast, sizeof(zend_ast_zval));
 		zend_persist_op_array(&copy->val);
 		node = (zend_ast *) copy;
+	} else if (zend_ast_is_decl(ast)) {
+		/* Not implemented. */
+		ZEND_UNREACHABLE();
 	} else {
 		uint32_t children = zend_ast_get_num_children(ast);
 		node = zend_shared_memdup(ast, zend_ast_size(children));

ext/opcache/zend_persist_calc.c

@@ -89,6 +89,9 @@ static void zend_persist_ast_calc(zend_ast *ast)
 	} else if (ast->kind == ZEND_AST_OP_ARRAY) {
 		ADD_SIZE(sizeof(zend_ast_zval));
 		zend_persist_op_array_calc(&((zend_ast_zval*)(ast))->val);
+	} else if (zend_ast_is_decl(ast)) {
+		/* Not implemented. */
+		ZEND_UNREACHABLE();
 	} else {
 		uint32_t children = zend_ast_get_num_children(ast);
 		ADD_SIZE(zend_ast_size(children));