def specialize_phi(node):
for parent_block, incoming_var in node.find_incoming():
if incoming_var.type.is_uninitialized:
incoming_type = incoming_var.type.base_type or node.type
bad = nodes.badval(incoming_type)
incoming_var.type.base_type = incoming_type
incoming_var.uninitialized_value = bad
# print incoming_var
elif not incoming_var.type == node.type:
# Create promotions for variables with phi nodes in successor
# blocks.
incoming_symtab = incoming_var.block.symtab
if (incoming_var, node.type) not in node.block.promotions:
# Make sure we only coerce once for each destination type and
# each variable
incoming_var.block.promotions.add((incoming_var, node.type))
# Create promotion node
name_node = nodes.Name(id=incoming_var.renamed_name,
ctx=ast.Load())
name_node.variable = incoming_var
name_node.type = incoming_var.type
coercion = name_node.coerce(node.type)
promotion = nodes.PromotionNode(node=coercion)
# Add promotion node to block body
incoming_var.block.body.append(promotion)
promotion.variable.block = incoming_var.block
# Update symtab
incoming_symtab.promotions[incoming_var.name,
node.type] = promotion
else:
promotion = incoming_symtab.lookup_promotion(
incoming_var.name, node.type)
return node
def visit_Name(self, old_node):
node = nodes.Name(old_node.id, old_node.ctx)
ast.copy_location(node, old_node)
return self._visit_Name(node)
def visit_arg(self, old_node, lineno, col_offset):
node = nodes.Name(old_node.arg, ast.Param())
node.lineno = lineno
node.col_offset = col_offset
return self._visit_Name(node)