(svn r8131) -Fix (r8125): g++ warning: 'invalid access to non-static data member ‘<class>::<member>’ of NULL object'. It is weird, but renaming the 'offsetof' macro helped.

src/oldloader.cpp

@@ -372,7 +372,7 @@ static void FixOldVehicles(void)
  *  - OCL_CHUNK: load an other proc to load a part of the savegame, 'amount' times
  *  - OCL_ASSERT: to check if we are really at the place we expect to be.. because old savegames are too binary to be sure ;)
  */
-#define OCL_SVAR(type, base, offset)         { type,          1, NULL,    (uint)offsetof(base, offset), NULL }
+#define OCL_SVAR(type, base, offset)         { type,          1, NULL,    (uint)cpp_offsetof(base, offset), NULL }
 #define OCL_VAR(type, amount, pointer)       { type,     amount, pointer, 0,                      NULL }
 #define OCL_END()                                   { OC_END,        0, NULL,    0,                      NULL }
 #define OCL_NULL(amount)                            { OC_NULL,  amount, NULL,    0,                      NULL }

src/saveload.h

@@ -183,7 +183,7 @@ typedef struct SaveLoad {
 typedef SaveLoad SaveLoadGlobVarList;
 
 /* Simple variables, references (pointers) and arrays */
-#define SLE_GENERAL(cmd, base, variable, type, length, from, to) {cmd, type, length, from, to, (void*)offsetof(base, variable)}
+#define SLE_GENERAL(cmd, base, variable, type, length, from, to) {cmd, type, length, from, to, (void*)cpp_offsetof(base, variable)}
 #define SLE_CONDVAR(base, variable, type, from, to) SLE_GENERAL(SL_VAR, base, variable, type, 0, from, to)
 #define SLE_CONDREF(base, variable, type, from, to) SLE_GENERAL(SL_REF, base, variable, type, 0, from, to)
 #define SLE_CONDARR(base, variable, type, length, from, to) SLE_GENERAL(SL_ARR, base, variable, type, length, from, to)

src/stdafx.h

@@ -290,10 +290,18 @@ assert_compile(sizeof(uint8)  == 1);
 #define lengthof(x) (sizeof(x)/sizeof(x[0]))
 #define endof(x) (&x[lengthof(x)])
 #define lastof(x) (&x[lengthof(x) - 1])
-#ifndef offsetof
-# define offsetof(s,m)   (size_t)&(((s *)0)->m)
+
+#ifdef offsetof
+# undef offsetof
 #endif
 
+#ifndef __cplusplus
+# define offsetof(s,m)   (size_t)&(((s *)0)->m)
+#else /* __cplusplus */
+# define cpp_offsetof(s,m)   (((size_t)&reinterpret_cast<const volatile char&>((((s*)(char*)8)->m))) - 8)
+# define offsetof(s,m)       cpp_offsetof(s, m)
+#endif /* __cplusplus */
+
 
 // take care of some name clashes on macos
 #if defined(__APPLE__)