[PATCH v3 4/4] tools: add offsetof() to xen-tools/common-macros.h

[Juergen Gross <jgross@xxxxxxxx>]

Instead of having multiple files defining offsetof(), add the
definition to tools/include/xen-tools/common-macros.h.

Signed-off-by: Juergen Gross <jgross@xxxxxxxx>
---
V3:
- don't modify tools/firmware/include/stddef.h (Jan Beulich)
---
 tools/firmware/hvmloader/util.h         | 3 ---
 tools/include/xen-tools/common-macros.h | 4 ++++
 tools/libfsimage/Rules.mk               | 2 ++
 tools/libfsimage/xfs/fsys_xfs.c         | 4 +---
 tools/libs/vchan/init.c                 | 4 ----
 tools/tests/vhpet/emul.h                | 2 --
 6 files changed, 7 insertions(+), 12 deletions(-)

diff --git a/tools/firmware/hvmloader/util.h b/tools/firmware/hvmloader/util.h
index e04990ee97..7249773eeb 100644
--- a/tools/firmware/hvmloader/util.h
+++ b/tools/firmware/hvmloader/util.h
@@ -30,9 +30,6 @@ enum {
 #define SEL_DATA32          0x0020
 #define SEL_CODE64          0x0028
 
-#undef offsetof
-#define offsetof(t, m) ((unsigned long)&((t *)0)->m)
-
 #undef NULL
 #define NULL ((void*)0)
 
diff --git a/tools/include/xen-tools/common-macros.h 
b/tools/include/xen-tools/common-macros.h
index b046ab48bf..b149be8365 100644
--- a/tools/include/xen-tools/common-macros.h
+++ b/tools/include/xen-tools/common-macros.h
@@ -80,4 +80,8 @@
     typeof( ((type *)0)->member ) *__mptr = (ptr);        \
     (type *)( (char *)__mptr - offsetof(type,member) );})
 
+#ifndef offsetof
+#define offsetof(a, b) __builtin_offsetof(a, b)
+#endif
+
 #endif /* __XEN_TOOLS_COMMON_MACROS__ */
diff --git a/tools/libfsimage/Rules.mk b/tools/libfsimage/Rules.mk
index cf37d6cb0d..85674f2379 100644
--- a/tools/libfsimage/Rules.mk
+++ b/tools/libfsimage/Rules.mk
@@ -3,6 +3,8 @@ include $(XEN_ROOT)/tools/libfsimage/common.mk
 FSLIB = fsimage.so
 TARGETS += $(FSLIB)
 
+CFLAGS += $(CFLAGS_xeninclude)
+
 .PHONY: all
 all: $(TARGETS)
 
diff --git a/tools/libfsimage/xfs/fsys_xfs.c b/tools/libfsimage/xfs/fsys_xfs.c
index d735a88e55..f562daaef0 100644
--- a/tools/libfsimage/xfs/fsys_xfs.c
+++ b/tools/libfsimage/xfs/fsys_xfs.c
@@ -19,6 +19,7 @@
 
 #include <xenfsimage_grub.h>
 #include "xfs.h"
+#include <xen-tools/common-macros.h>
 
 #define MAX_LINK_COUNT 8
 
@@ -182,9 +183,6 @@ fsb2daddr (xfs_fsblock_t fsbno)
                         (xfs_agblock_t)(fsbno & mask32lo(xfs.agblklog)));
 }
 
-#undef offsetof
-#define offsetof(t,m)  ((size_t)&(((t *)0)->m))
-
 static inline int
 btroot_maxrecs (fsi_file_t *ffi)
 {
diff --git a/tools/libs/vchan/init.c b/tools/libs/vchan/init.c
index 021e1f29e1..ad4cc66d2c 100644
--- a/tools/libs/vchan/init.c
+++ b/tools/libs/vchan/init.c
@@ -69,10 +69,6 @@
 #define MAX_RING_SHIFT 20
 #define MAX_RING_SIZE (1 << MAX_RING_SHIFT)
 
-#ifndef offsetof
-#define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER)
-#endif
-
 static int init_gnt_srv(struct libxenvchan *ctrl, int domain)
 {
        int pages_left = ctrl->read.order >= PAGE_SHIFT ? 1 << 
(ctrl->read.order - PAGE_SHIFT) : 0;
diff --git a/tools/tests/vhpet/emul.h b/tools/tests/vhpet/emul.h
index 6af880cd43..7b3ee88fb5 100644
--- a/tools/tests/vhpet/emul.h
+++ b/tools/tests/vhpet/emul.h
@@ -115,8 +115,6 @@ enum
     NR_COMMON_SOFTIRQS
 };
 
-#define offsetof(t, m) ((unsigned long )&((t *)0)->m)
-
 struct domain;
 
 struct vcpu
-- 
2.35.3