Hi,
While working on a patch to change some error to inform, I changed
the as_a cast in RTL_LOCATION to be as_a <const rtx_insn *>. This
falls down when you start with a rtx rather than a const_rtx..
I had to modify is-a.h to this but I really don't like the
modification at all since it shows the bigger issues with templates.
Can anyone think of a better way of supporting this? Attached is my
patch currently which is able to bootstrap with the modification to
RTL_LOCATION being there.
Thanks,
Andrew Pinski
Index: is-a.h
===================================================================
--- is-a.h (revision 217985)
+++ is-a.h (working copy)
@@ -147,10 +147,26 @@ struct is_a_helper
{
template <typename U>
static inline bool test (U *p);
+ static inline bool test (T *) { return true; }
template <typename U>
static inline T cast (U *p);
};
+
+template <typename T>
+struct is_a_helper<const T*>
+{
+ template <typename U>
+ static inline bool test (const U *p);
+ template <typename U>
+ static inline bool test (U *p) {return test(const_cast<const U*>(p));}
+ static inline bool test (const T *) { return true; }
+ template <typename U>
+ static inline const T *cast (const U *p);
+ template <typename U>
+ static inline const T *cast (U *p) { return cast(const_cast<const U*>(p)); }
+};
+
/* Note that we deliberately do not define the 'test' member template. Not
doing so will result in a build-time error for type relationships that have
not been defined, rather than a run-time error. See the discussion above
@@ -169,6 +185,15 @@ is_a_helper <T>::cast (U *p)
}
+template <typename T>
+template <typename U>
+inline const T*
+is_a_helper <const T*>::cast (const U *p)
+{
+ return reinterpret_cast <const T*> (p);
+}
+
+
/* The public interface. */
/* A generic test for a type relationship. See the discussion above for when
