Codechange: Remove all remaining uses of cpp_offset.

src/newgrf_debug_gui.cpp

@@ -79,10 +79,12 @@ enum NIType {
 	NIT_CARGO, ///< The property is a cargo
 };
 
+typedef const void *NIOffsetProc(const void *b);
+
 /** Representation of the data from a NewGRF property. */
 struct NIProperty {
 	const char *name;          ///< A (human readable) name for the property
-	ptrdiff_t offset;       ///< Offset of the variable in the class
+	NIOffsetProc *offset_proc; ///< Callback proc to get the actual variable address in memory
 	byte read_size;            ///< Number of bytes (i.e. byte, word, dword etc)
 	byte prop;                 ///< The number of the property
 	byte type;
@@ -95,7 +97,7 @@ struct NIProperty {
  */
 struct NICallback {
 	const char *name;          ///< The human readable name of the callback
-	ptrdiff_t offset; ///< Offset of the variable in the class
+	NIOffsetProc *offset_proc; ///< Callback proc to get the actual variable address in memory
 	byte read_size;            ///< The number of bytes (i.e. byte, word, dword etc) to read
 	byte cb_bit;               ///< The bit that needs to be set for this callback to be enabled
 	uint16 cb_id;              ///< The number of the callback
@@ -491,7 +493,7 @@ struct NewGRFInspectWindow : Window {
 		if (nif->properties != nullptr) {
 			this->DrawString(r, i++, "Properties:");
 			for (const NIProperty *nip = nif->properties; nip->name != nullptr; nip++) {
-				const void *ptr = (const byte *)base + nip->offset;
+				const void *ptr = nip->offset_proc(base);
 				uint value;
 				switch (nip->read_size) {
 					case 1: value = *(const uint8  *)ptr; break;
@@ -525,7 +527,7 @@ struct NewGRFInspectWindow : Window {
 			this->DrawString(r, i++, "Callbacks:");
 			for (const NICallback *nic = nif->callbacks; nic->name != nullptr; nic++) {
 				if (nic->cb_bit != CBM_NO_BIT) {
-					const void *ptr = (const byte *)base_spec + nic->offset;
+					const void *ptr = nic->offset_proc(base_spec);
 					uint value;
 					switch (nic->read_size) {
 						case 1: value = *(const uint8  *)ptr; break;

src/stdafx.h

@@ -392,18 +392,13 @@ static_assert(SIZE_MAX >= UINT32_MAX);
  */
 #define lastof(x) (&x[lengthof(x) - 1])
 
-#define cpp_offsetof(s, m)   (((size_t)&reinterpret_cast<const volatile char&>((((s*)(char*)8)->m))) - 8)
-#if !defined(offsetof)
-#	define offsetof(s, m) cpp_offsetof(s, m)
-#endif /* offsetof */
-
 /**
  * Gets the size of a variable within a class.
  * @param base     The class the variable is in.
  * @param variable The variable to get the size of.
  * @return the size of the variable
  */
-#define cpp_sizeof(base, variable) (sizeof(((base*)8)->variable))
+#define cpp_sizeof(base, variable) (sizeof(std::declval<base>().variable))
 
 /**
  * Gets the length of an array variable within a class.

src/table/newgrf_debug_data.h

@@ -12,11 +12,11 @@
 #include "../newgrf_roadtype.h"
 
 /* Helper for filling property tables */
-#define NIP(prop, base, variable, type, name) { name, (ptrdiff_t)cpp_offsetof(base, variable), cpp_sizeof(base, variable), prop, type }
+#define NIP(prop, base, variable, type, name) { name, [] (const void *b) -> const void * { return std::addressof(static_cast<const base *>(b)->variable); }, cpp_sizeof(base, variable), prop, type }
 #define NIP_END() { nullptr, 0, 0, 0, 0 }
 
 /* Helper for filling callback tables */
-#define NIC(cb_id, base, variable, bit) { #cb_id, (ptrdiff_t)cpp_offsetof(base, variable), cpp_sizeof(base, variable), bit, cb_id }
+#define NIC(cb_id, base, variable, bit) { #cb_id, [] (const void *b) -> const void * { return std::addressof(static_cast<const base *>(b)->variable); }, cpp_sizeof(base, variable), bit, cb_id }
 #define NIC_END() { nullptr, 0, 0, 0, 0 }
 
 /* Helper for filling variable tables */