fhdl: support nested statement lists

migen/fhdl/tools.py

@@ -2,6 +2,14 @@ from migen.fhdl.structure import *
 from migen.fhdl.structure import _Operator, _Slice, _Assign, _ArrayProxy
 from migen.fhdl.visit import NodeVisitor, NodeTransformer
 
+def flat_iteration(l):
+	for element in l:
+		if isinstance(element, (list, tuple)):
+			for element2 in flat_iteration(element):
+				yield element2
+		else:
+			yield element
+
 class _SignalLister(NodeVisitor):
 	def __init__(self):
 		self.output_list = set()
@@ -35,7 +43,7 @@ def list_targets(node):
 
 def group_by_targets(sl):
 	groups = []
-	for statement in sl:
+	for statement in flat_iteration(sl):
 		targets = list_targets(statement)
 		processed = False
 		for g in groups:

migen/fhdl/verilog.py

@@ -97,7 +97,7 @@ def _printnode(ns, at, level, node):
 		else:
 			assignment = " <= "
 		return "\t"*level + _printexpr(ns, node.l)[0] + assignment + _printexpr(ns, node.r)[0] + ";\n"
-	elif isinstance(node, list):
+	elif isinstance(node, (list, tuple)):
 		return "".join(list(map(partial(_printnode, ns, at, level), node)))
 	elif isinstance(node, If):
 		r = "\t"*level + "if (" + _printexpr(ns, node.cond)[0] + ") begin\n"

migen/fhdl/visit.py

@@ -25,7 +25,7 @@ class NodeVisitor:
 			self.visit_Case(node)
 		elif isinstance(node, Fragment):
 			self.visit_Fragment(node)
-		elif isinstance(node, list):
+		elif isinstance(node, (list, tuple)):
 			self.visit_statements(node)
 		elif isinstance(node, dict):
 			self.visit_clock_domains(node)
@@ -115,7 +115,7 @@ class NodeTransformer:
 			return self.visit_Case(node)
 		elif isinstance(node, Fragment):
 			return self.visit_Fragment(node)
-		elif isinstance(node, list):
+		elif isinstance(node, (list, tuple)):
 			return self.visit_statements(node)
 		elif isinstance(node, dict):
 			return self.visit_clock_domains(node)
@@ -164,6 +164,7 @@ class NodeTransformer:
 		r.sync = self.visit(node.sync)
 		return r
 	
+	# NOTE: this will always return a list, even if node is a tuple
 	def visit_statements(self, node):
 		return [self.visit(statement) for statement in node]