From: whitequark <whitequark@whitequark.org>
Date: Thu, 15 Oct 2020 08:54:48 +0000 (+0000)
Subject: build.plat: avoid type confusion in _check_feature.
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=d22b2c56041e27031690415d1fb23a09d17999e8;p=nmigen.git

build.plat: avoid type confusion in _check_feature.

Before this commit, `_check_feature(valid_xdrs=0)` would mean that
XDR buffers are not supported. Only `_check_feature(valid_xdrs=())`
was intended to be an indicator of that.
---

diff --git a/nmigen/build/plat.py b/nmigen/build/plat.py
index 6384249..31c9704 100644
--- a/nmigen/build/plat.py
+++ b/nmigen/build/plat.py
@@ -177,7 +177,7 @@ class Platform(ResourceManager, metaclass=ABCMeta):
                                   .format(type(self).__name__))
 
     def _check_feature(self, feature, pin, attrs, valid_xdrs, valid_attrs):
-        if not valid_xdrs:
+        if len(valid_xdrs) == 0:
             raise NotImplementedError("Platform '{}' does not support {}"
                                       .format(type(self).__name__, feature))
         elif pin.xdr not in valid_xdrs: