yosys: check for input/sdc before accessing
@@ -452,6 +452,7 @@ def get_abc_period(chip):
period = None
# get clock information from sdc files
+ if chip.valid('input', 'sdc'):
for sdc in chip.find_files('input', 'sdc'):
lines = []
with open(sdc, 'r') as f:
