move clamp_basetype into make_setter

this avoids a double dereference.

vyper/old_codegen/abi.py

@@ -498,6 +498,7 @@ def abi_encode(dst, lll_node, pos=None, bufsz=None, returns_len=False):
     return LLLnode.from_list(lll_ret, pos=pos, annotation=f"abi_encode {lll_node.typ}")
 
 
+# CMC 20211002 this is probably dead code because make_setter does this.
 # lll_node is the destination LLL item, src is the input buffer.
 # recursively copy the buffer items into lll_node, based on its type.
 # src: pointer to beginning of buffer

vyper/old_codegen/parser_utils.py

@@ -317,17 +317,8 @@ def _abi_helper(member_t, ofst, clamp=True):
             ["ofst"], typ=member_t, location=parent.location, annotation=f"&({typ}->{member_t})"
         )
 
-        if clamp and _needs_clamp(member_t, parent.encoding):
-            # special handling for unsanitized external data that need clamping
-            # TODO optimize me. this results in a double dereference because
-            # it returns a pointer and not a value. probably the best thing
-            # is to move the clamp to make_setter
-            ret = ["with", x, ofst_lll, ["seq", clamp_basetype(x), x]]
-        else:
-            ret = ofst_lll
-
         return LLLnode.from_list(
-            ret,
+            ofst_lll,
             typ=member_t,
             location=parent.location,
             encoding=parent.encoding,
@@ -553,15 +544,29 @@ def make_setter(left, right, pos):
 
     # Basic types
     if isinstance(left.typ, BaseType):
+        enc = right.encoding  # unwrap_location butchers encoding
         right = unwrap_location(right)
+        # TODO rethink/streamline the clamp_basetype logic
+        if _needs_clamp(right.typ, enc):
+            _val = LLLnode("val", typ=right.typ)
+            right = ["with", _val, right, ["seq", clamp_basetype(_val), _val]]
+
         if left.location == "storage":
             return LLLnode.from_list(["sstore", left, right], typ=None)
         elif left.location == "memory":
             return LLLnode.from_list(["mstore", left, right], typ=None)
 
     # Byte arrays
     elif isinstance(left.typ, ByteArrayLike):
-        return make_byte_array_copier(left, right, pos)
+        # TODO rethink/streamline the clamp_basetype logic
+        if _needs_clamp(right.typ, right.encoding):
+            _val = LLLnode("val", location=right.location, typ=right.typ)
+            copier = make_byte_array_copier(left, _val, pos)
+            ret = ["with", _val, right, ["seq", clamp_basetype(_val), copier]]
+        else:
+            ret = make_byte_array_copier(left, right, pos)
+
+        return LLLnode.from_list(ret)
 
     # Arrays
     elif isinstance(left.typ, (ListType, TupleLike)):
@@ -728,7 +733,8 @@ def _sar(x, bits):
 
 
 def _needs_clamp(t, encoding):
-    assert encoding in (Encoding.ABI, Encoding.JSON_ABI)
+    if encoding not in (Encoding.ABI, Encoding.JSON_ABI):
+        return False
     if isinstance(t, ByteArrayLike):
         if encoding == Encoding.JSON_ABI:
             # don't have bytestring size bound from json, don't clamp