Array lengths

1 files changed, 9 insertions, 1 deletions

diff --git a/cffi/cffi_opcode.py b/cffi/cffi_opcode.py
index 1506b1c..8596055 100644
--- a/cffi/cffi_opcode.py
+++ b/cffi/cffi_opcode.py
@@ -12,7 +12,15 @@ class CffiOp(object):
         return '_CFFI_OP(_CFFI_OP_%s, %d)' % (classname, self.arg)
 
     def as_python_bytes(self):
-        assert self.op is not None
+        if self.op is None:
+            if self.arg.isdigit():
+                value = int(self.arg)     # non-negative: '-' not in self.arg
+                if value >= 2**31:
+                    raise OverflowError("cannot emit %r: limited to 2**31-1"
+                                        % (self.arg,))
+                return format_four_bytes(value)
+            from .ffiplatform import VerificationError
+            raise VerificationError("cannot emit to Python: %r" % (self.arg,))
         return format_four_bytes((self.arg << 8) | self.op)
 
     def __str__(self):