From 11c66029b72ddc2ccb28e910fb16ee9975e0eafd Mon Sep 17 00:00:00 2001 From: Sascha Silbe Date: Thu, 1 Mar 2018 23:38:18 -0500 Subject: [PATCH] error: error_setg_errno(): errno gets preserved C11 allows errno to be clobbered by pretty much any library function call, so in general callers need to take care to save errno before calling other functions. However, for error reporting functions this is rather awkward and can make the code on the caller side more complicated than necessary. error_setg_errno() already takes care of preserving errno and some functions rely on that, so just promise that we continue to do so in the future. Backports commit 98cb89af4df7e1776ce418ed6167b6e214a64435 from qemu --- qemu/include/qapi/error.h | 3 +++ 1 file changed, 3 insertions(+) diff --git a/qemu/include/qapi/error.h b/qemu/include/qapi/error.h index b3061ebd..3a328cb3 100644 --- a/qemu/include/qapi/error.h +++ b/qemu/include/qapi/error.h @@ -172,6 +172,9 @@ void error_setg_internal(Error **errp, * Just like error_setg(), with @os_error info added to the message. * If @os_error is non-zero, ": " + strerror(os_error) is appended to * the human-readable error message. + * + * The value of errno (which usually can get clobbered by almost any + * function call) will be preserved. */ #define error_setg_errno(errp, os_error, fmt, ...) \ error_setg_errno_internal((errp), __FILE__, __LINE__, __func__, \