Relax the temporary same-instance copying limitation

Author: lukewagner

design/mvp/canonical-abi/definitions.py

@@ -851,7 +851,7 @@ def read(self, inst, dst_buffer, on_copy, on_copy_done):
       self.set_pending(inst, dst_buffer, on_copy, on_copy_done)
     else:
       assert(self.t == dst_buffer.t == self.pending_buffer.t)
-      trap_if(inst is self.pending_inst and self.t is not None) # temporary
+      trap_if(inst is self.pending_inst and self.t and not is_number_type(self.t)) # temporary
       if self.pending_buffer.remain() > 0:
         if dst_buffer.remain() > 0:
           n = min(dst_buffer.remain(), self.pending_buffer.remain())
@@ -869,7 +869,7 @@ def write(self, inst, src_buffer, on_copy, on_copy_done):
       self.set_pending(inst, src_buffer, on_copy, on_copy_done)
     else:
       assert(self.t == src_buffer.t == self.pending_buffer.t)
-      trap_if(inst is self.pending_inst and self.t is not None) # temporary
+      trap_if(inst is self.pending_inst and self.t and not is_number_type(self.t)) # temporary
       if self.pending_buffer.remain() > 0:
         if src_buffer.remain() > 0:
           n = min(src_buffer.remain(), self.pending_buffer.remain())
@@ -882,6 +882,11 @@ def write(self, inst, src_buffer, on_copy, on_copy_done):
         self.reset_and_notify_pending(CopyResult.COMPLETED)
         self.set_pending(inst, src_buffer, on_copy, on_copy_done)
 
+def is_number_type(t):
+  return isinstance(t, U8Type | U16Type | U32Type | U64Type |
+                       S8Type | S16Type | S32Type | S64Type |
+                       F32Type | F64Type)
+
 class CopyState(Enum):
   IDLE = 1
   SYNC_COPYING = 2
@@ -983,7 +988,7 @@ def read(self, inst, dst_buffer, on_copy_done):
     if not self.pending_buffer:
       self.set_pending(inst, dst_buffer, on_copy_done)
     else:
-      trap_if(inst is self.pending_inst and self.t is not None) # temporary
+      trap_if(inst is self.pending_inst and self.t and not is_number_type(self.t)) # temporary
       dst_buffer.write(self.pending_buffer.read(1))
       self.reset_and_notify_pending(CopyResult.COMPLETED)
       on_copy_done(CopyResult.COMPLETED)
@@ -995,7 +1000,7 @@ def write(self, inst, src_buffer, on_copy_done):
     elif not self.pending_buffer:
       self.set_pending(inst, src_buffer, on_copy_done)
     else:
-      trap_if(inst is self.pending_inst and self.t is not None) # temporary
+      trap_if(inst is self.pending_inst and self.t and not is_number_type(self.t)) # temporary
       self.pending_buffer.write(src_buffer.read(1))
       self.reset_and_notify_pending(CopyResult.COMPLETED)
       on_copy_done(CopyResult.COMPLETED)