osdep: Remove local definition of macro offsetof

The macro offsetof is defined in stddef.h. It is conforming to
the standards C89, C99 and POSIX.1-2001 (see man page), so it
is a sufficiently old standard.

Therefore chances are very high that QEMU never needs a local
definition of this macro.

osdep.h already includes stddef.h, so this patch simply removes
the unneeded code from the files configure and osdep.h.

If we ever need the local definition again, it should be added
to compiler.h (the macro is usually provided with the compiler,
it is not OS specific).

Signed-off-by: Stefan Weil <[email protected]>
Signed-off-by: Stefan Hajnoczi <[email protected]>

diff --git a/configure b/configure
index e19b6e3b5de2cd89141966b6bd543f00c5f9597e..ed3d907911972f39d4d63b581347d323dd47d274 100755 (executable)
--- a/configure
+++ b/configure
@@ -2524,17 +2524,6 @@ if test "$darwin" != "yes" -a "$mingw32" != "yes" -a "$solaris" != yes -a \
 fi
 
 ##########################################
-# check if the compiler defines offsetof
-
-need_offsetof=yes
-cat > $TMPC << EOF
-#include <stddef.h>
-int main(void) { struct s { int f; }; return offsetof(struct s, f); }
-EOF
-if compile_prog "" "" ; then
-    need_offsetof=no
-fi
-
 # spice probe
 if test "$spice" != "no" ; then
   cat > $TMPC << EOF
@@ -3199,9 +3188,6 @@ fi
 if test "$tcg_interpreter" = "yes" ; then
   echo "CONFIG_TCG_INTERPRETER=y" >> $config_host_mak
 fi
-if test "$need_offsetof" = "yes" ; then
-  echo "CONFIG_NEED_OFFSETOF=y" >> $config_host_mak
-fi
 if test "$fdatasync" = "yes" ; then
   echo "CONFIG_FDATASYNC=y" >> $config_host_mak
 fi

diff --git a/osdep.h b/osdep.h
index 432b91ea7293037c758598465a8e846e83356ee2..03503837119bbaaa1f9c82f20cadf3156811ab04 100644 (file)
--- a/osdep.h
+++ b/osdep.h
@@ -26,9 +26,6 @@
 #define unlikely(x)   __builtin_expect(!!(x), 0)
 #endif
 
-#ifdef CONFIG_NEED_OFFSETOF
-#define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *) 0)->MEMBER)
-#endif
 #ifndef container_of
 #define container_of(ptr, type, member) ({                      \
         const typeof(((type *) 0)->member) *__mptr = (ptr);     \