rt: Have data::walk_fn be defensive regarding whether the derived implementation of walk_fn moves the data pointer

pcwalton · pcwalton · commit f1ed03dfa5ae · 2011-08-29T16:50:06.000-07:00
diff --git a/src/rt/rust_shape.h b/src/rt/rust_shape.h
@@ -775,8 +775,9 @@ class data : public ctxt< data<T,U> > {
 
     void walk_fn(bool align) {
         if (align) dp = align_to(dp, sizeof(void *));
+        U next_dp = dp + sizeof(void *) * 2;
         static_cast<T *>(this)->walk_fn(align);
-        dp += sizeof(void *) * 2;
+        dp = next_dp;
     }
 
     void walk_obj(bool align) {

Original file line number	Diff line number	Diff line change
`@@ -775,8 +775,9 @@ class data : public ctxt< data<T,U> > {`
`775`	`775`
`776`	`776`	`void walk_fn(bool align) {`
`777`	`777`	`if (align) dp = align_to(dp, sizeof(void *));`
	`778`	`+ U next_dp = dp + sizeof(void ) 2;`
`778`	`779`	`static_cast<T *>(this)->walk_fn(align);`
`779`		`- dp += sizeof(void ) 2;`
	`780`	`+ dp = next_dp;`
`780`	`781`	`}`
`781`	`782`
`782`	`783`	`void walk_obj(bool align) {`