def __init__(self):
super(SSARewrite, self).__init__()
self.functions = []
self.assignments = Counter()
self.block = blocks.BasicBlock()
self.start_block = self.block
self.functions.append(
('__module', btypes.void_type, [], self.start_block))
def visit_WhileStatement(self, node):
whileblock = blocks.WhileBlock()
self.block.next_block = whileblock
self.block = whileblock
# Evaluate the condition
self.visit(node.condition)
# Save the variable where the test value is stored
whileblock.testvar = node.condition.ssa_name
# Traverse the body
whileblock.body = blocks.BasicBlock()
self.block = whileblock.body
self.visit(node.statements)
# Create the terminating block
self.block = blocks.BasicBlock()
whileblock.next_block = self.block
def visit_IfElseStatement(self, node):
ifblock = blocks.IfBlock()
self.block.next_block = ifblock
self.block = ifblock
self.visit(node.condition)
ifblock.testvar = node.condition.ssa_name
ifblock.true_branch = blocks.BasicBlock()
self.block = ifblock.true_branch
self.visit(node.if_statements)
if node.else_statements:
ifblock.false_branch = blocks.BasicBlock()
self.block = ifblock.false_branch
self.visit(node.else_statements)
self.block = blocks.BasicBlock()
ifblock.next_block = self.block
def visit_ForStatement(self, node):
forblock = blocks.ForBlock()
self.block.next_block = forblock
self.block = forblock
self.visit(node.iter)
# store the temporary variable locations for the range
# parameter.
forblock.start_var = node.iter.start.ssa_name
forblock.stop_var = node.iter.stop.ssa_name
forblock.var = node.var
# Generate blocks for the body
forblock.body = blocks.BasicBlock()
self.block = forblock.body
self.visit(node.body)
# End the loop
self.block = blocks.BasicBlock()
forblock.next_block = self.block
def visit_FunctionDef(self, node):
last_block = self.block # pop
self.block = blocks.BasicBlock()
retty = node.sig.typename.type
argtys = [arg.type for arg in node.sig.parameters]
fn = (node.sig.name, retty, argtys, self.block)
self.functions.append(fn)
for n, parm in enumerate(node.sig.parameters):
inst = ('LOAD_ARGUMENT', parm.type, parm.name, n)
self.block.append(inst)
self.visit(node.statements)
if node.sig.type == btypes.void_type:
self.block.append(('RETURN', btypes.void_type))
self.block = last_block # push