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[Qemu-devel] [PULL 03/16] compiler: expression version of QEMU_BUILD_BUG
From: |
Michael S. Tsirkin |
Subject: |
[Qemu-devel] [PULL 03/16] compiler: expression version of QEMU_BUILD_BUG_ON |
Date: |
Wed, 25 Jan 2017 00:36:26 +0200 |
QEMU_BUILD_BUG_ON uses a typedef in order to be safe
to use outside functions, but sometimes it's useful
to have a version that can be used within an expression.
Following what Linux does, introduce QEMU_BUILD_BUG_ON_ZERO
that return zero after checking condition at build time.
Signed-off-by: Michael S. Tsirkin <address@hidden>
Reviewed-by: Eric Blake <address@hidden>
Reviewed-by: Markus Armbruster <address@hidden>
---
include/qemu/compiler.h | 3 +++
1 file changed, 3 insertions(+)
diff --git a/include/qemu/compiler.h b/include/qemu/compiler.h
index 1da500e..e0fb18b 100644
--- a/include/qemu/compiler.h
+++ b/include/qemu/compiler.h
@@ -92,6 +92,9 @@
#define QEMU_BUILD_BUG_ON(x) typedef QEMU_BUILD_BUG_ON_STRUCT(x) \
glue(qemu_build_bug_on__, __LINE__) __attribute__((unused))
+#define QEMU_BUILD_BUG_ON_ZERO(x) (sizeof(QEMU_BUILD_BUG_ON_STRUCT(x)) - \
+ sizeof(QEMU_BUILD_BUG_ON_STRUCT(x)))
+
#if defined __GNUC__
# if !QEMU_GNUC_PREREQ(4, 4)
/* gcc versions before 4.4.x don't support gnu_printf, so use printf. */
--
MST
- [Qemu-devel] [PULL 00/16] virtio, vhost, pci: fixes, features, Michael S. Tsirkin, 2017/01/24
- [Qemu-devel] [PULL 01/16] compiler: drop ; after BUILD_BUG_ON, Michael S. Tsirkin, 2017/01/24
- [Qemu-devel] [PULL 02/16] compiler: rework BUG_ON using a struct, Michael S. Tsirkin, 2017/01/24
- [Qemu-devel] [PULL 03/16] compiler: expression version of QEMU_BUILD_BUG_ON,
Michael S. Tsirkin <=
- [Qemu-devel] [PULL 04/16] ARRAY_SIZE: check that argument is an array, Michael S. Tsirkin, 2017/01/24
- [Qemu-devel] [PULL 05/16] pci: mark ROMs read-only, Michael S. Tsirkin, 2017/01/24
- [Qemu-devel] [PULL 07/16] hw/pcie: Introduce a base class for PCI Express Root Ports, Michael S. Tsirkin, 2017/01/24
- [Qemu-devel] [PULL 06/16] intel_iommu: fix and simplify size calculation in process_device_iotlb_desc(), Michael S. Tsirkin, 2017/01/24
- [Qemu-devel] [PULL 08/16] hw/ioh3420: derive from PCI Express Root Port base class, Michael S. Tsirkin, 2017/01/24
- [Qemu-devel] [PULL 09/16] hw/pcie: Introduce Generic PCI Express Root Port, Michael S. Tsirkin, 2017/01/24
- [Qemu-devel] [PULL 10/16] hw/i386: check if nvdimm is enabled before plugging, Michael S. Tsirkin, 2017/01/24
- [Qemu-devel] [PULL 11/16] msix: Follow CODING_STYLE, Michael S. Tsirkin, 2017/01/24
- [Qemu-devel] [PULL 12/16] hcd-xhci: check & correct param before using it, Michael S. Tsirkin, 2017/01/24
- [Qemu-devel] [PULL 15/16] vhost: skip ROM sections, Michael S. Tsirkin, 2017/01/24