Improve generated names for anonymous classes

In order of preference, the generated name will be:

    new class extends ParentClass {};
    // -> ParentClass@anonymous
    new class implements FirstInterface, SecondInterface {};
    // -> FirstInterface@anonymous
    new class {};
    // -> class@anonymous

This is intended to display a more useful class name in error messages
and stack traces, and thus make debugging easier.

Closes GH-5153.

1 files changed, 16 insertions, 5 deletions

diff --git a/Zend/zend_compile.c b/Zend/zend_compile.c
index 58fb3377d2..bc0a7dfdae 100644
--- a/Zend/zend_compile.c
+++ b/Zend/zend_compile.c
@@ -6569,14 +6569,25 @@ void zend_compile_implements(zend_ast *ast) /* {{{ */
 }
 /* }}} */
 
-static zend_string *zend_generate_anon_class_name(uint32_t start_lineno) /* {{{ */
+static zend_string *zend_generate_anon_class_name(zend_ast_decl *decl)
 {
 	zend_string *filename = CG(active_op_array)->filename;
-	zend_string *result = zend_strpprintf(0, "class@anonymous%c%s:%" PRIu32 "$%" PRIx32,
-		'\0', ZSTR_VAL(filename), start_lineno, CG(rtd_key_counter)++);
+	uint32_t start_lineno = decl->start_lineno;
+
+	/* Use parent or first interface as prefix. */
+	zend_string *prefix = ZSTR_KNOWN(ZEND_STR_CLASS);
+	if (decl->child[0]) {
+		prefix = zend_resolve_const_class_name_reference(decl->child[0], "class name");
+	} else if (decl->child[1]) {
+		zend_ast_list *list = zend_ast_get_list(decl->child[1]);
+		prefix = zend_resolve_const_class_name_reference(list->child[0], "interface name");
+	}
+
+	zend_string *result = zend_strpprintf(0, "%s@anonymous%c%s:%" PRIu32 "$%" PRIx32,
+		ZSTR_VAL(prefix), '\0', ZSTR_VAL(filename), start_lineno, CG(rtd_key_counter)++);
+	zend_string_release(prefix);
 	return zend_new_interned_string(result);
 }
-/* }}} */
 
 zend_op *zend_compile_class_decl(zend_ast *ast, zend_bool toplevel) /* {{{ */
 {
@@ -6613,7 +6624,7 @@ zend_op *zend_compile_class_decl(zend_ast *ast, zend_bool toplevel) /* {{{ */
 
 		zend_register_seen_symbol(lcname, ZEND_SYMBOL_CLASS);
 	} else {
-		name = zend_generate_anon_class_name(decl->start_lineno);
+		name = zend_generate_anon_class_name(decl);
 		lcname = zend_string_tolower(name);
 	}
 	lcname = zend_new_interned_string(lcname);