Permalink
Cannot retrieve contributors at this time
| ############################################################################### | |
| # AST visualizer - generates a DOT file for Graphviz. # | |
| # # | |
| # To generate an image from the DOT file run $ dot -Tpng -o ast.png ast.dot # | |
| # # | |
| ############################################################################### | |
| import argparse | |
| import textwrap | |
| from spi import Lexer, Parser, NodeVisitor | |
| class ASTVisualizer(NodeVisitor): | |
| def __init__(self, parser): | |
| self.parser = parser | |
| self.ncount = 1 | |
| self.dot_header = [textwrap.dedent("""\ | |
| digraph astgraph { | |
| node [shape=circle, fontsize=12, fontname="Courier", height=.1]; | |
| ranksep=.3; | |
| edge [arrowsize=.5] | |
| """)] | |
| self.dot_body = [] | |
| self.dot_footer = ['}'] | |
| def visit_Program(self, node): | |
| s = ' node{} [label="Program"]\n'.format(self.ncount) | |
| self.dot_body.append(s) | |
| node._num = self.ncount | |
| self.ncount += 1 | |
| self.visit(node.block) | |
| s = ' node{} -> node{}\n'.format(node._num, node.block._num) | |
| self.dot_body.append(s) | |
| def visit_Block(self, node): | |
| s = ' node{} [label="Block"]\n'.format(self.ncount) | |
| self.dot_body.append(s) | |
| node._num = self.ncount | |
| self.ncount += 1 | |
| for declaration in node.declarations: | |
| self.visit(declaration) | |
| self.visit(node.compound_statement) | |
| for decl_node in node.declarations: | |
| s = ' node{} -> node{}\n'.format(node._num, decl_node._num) | |
| self.dot_body.append(s) | |
| s = ' node{} -> node{}\n'.format( | |
| node._num, | |
| node.compound_statement._num | |
| ) | |
| self.dot_body.append(s) | |
| def visit_VarDecl(self, node): | |
| s = ' node{} [label="VarDecl"]\n'.format(self.ncount) | |
| self.dot_body.append(s) | |
| node._num = self.ncount | |
| self.ncount += 1 | |
| self.visit(node.var_node) | |
| s = ' node{} -> node{}\n'.format(node._num, node.var_node._num) | |
| self.dot_body.append(s) | |
| self.visit(node.type_node) | |
| s = ' node{} -> node{}\n'.format(node._num, node.type_node._num) | |
| self.dot_body.append(s) | |
| def visit_ProcedureDecl(self, node): | |
| s = ' node{} [label="ProcDecl:{}"]\n'.format( | |
| self.ncount, | |
| node.proc_name | |
| ) | |
| self.dot_body.append(s) | |
| node._num = self.ncount | |
| self.ncount += 1 | |
| for param_node in node.params: | |
| self.visit(param_node) | |
| s = ' node{} -> node{}\n'.format(node._num, param_node._num) | |
| self.dot_body.append(s) | |
| self.visit(node.block_node) | |
| s = ' node{} -> node{}\n'.format(node._num, node.block_node._num) | |
| self.dot_body.append(s) | |
| def visit_Param(self, node): | |
| s = ' node{} [label="Param"]\n'.format(self.ncount) | |
| self.dot_body.append(s) | |
| node._num = self.ncount | |
| self.ncount += 1 | |
| self.visit(node.var_node) | |
| s = ' node{} -> node{}\n'.format(node._num, node.var_node._num) | |
| self.dot_body.append(s) | |
| self.visit(node.type_node) | |
| s = ' node{} -> node{}\n'.format(node._num, node.type_node._num) | |
| self.dot_body.append(s) | |
| def visit_Type(self, node): | |
| s = ' node{} [label="{}"]\n'.format(self.ncount, node.token.value) | |
| self.dot_body.append(s) | |
| node._num = self.ncount | |
| self.ncount += 1 | |
| def visit_Num(self, node): | |
| s = ' node{} [label="{}"]\n'.format(self.ncount, node.token.value) | |
| self.dot_body.append(s) | |
| node._num = self.ncount | |
| self.ncount += 1 | |
| def visit_BinOp(self, node): | |
| s = ' node{} [label="{}"]\n'.format(self.ncount, node.op.value) | |
| self.dot_body.append(s) | |
| node._num = self.ncount | |
| self.ncount += 1 | |
| self.visit(node.left) | |
| self.visit(node.right) | |
| for child_node in (node.left, node.right): | |
| s = ' node{} -> node{}\n'.format(node._num, child_node._num) | |
| self.dot_body.append(s) | |
| def visit_UnaryOp(self, node): | |
| s = ' node{} [label="unary {}"]\n'.format(self.ncount, node.op.value) | |
| self.dot_body.append(s) | |
| node._num = self.ncount | |
| self.ncount += 1 | |
| self.visit(node.expr) | |
| s = ' node{} -> node{}\n'.format(node._num, node.expr._num) | |
| self.dot_body.append(s) | |
| def visit_Compound(self, node): | |
| s = ' node{} [label="Compound"]\n'.format(self.ncount) | |
| self.dot_body.append(s) | |
| node._num = self.ncount | |
| self.ncount += 1 | |
| for child in node.children: | |
| self.visit(child) | |
| s = ' node{} -> node{}\n'.format(node._num, child._num) | |
| self.dot_body.append(s) | |
| def visit_Assign(self, node): | |
| s = ' node{} [label="{}"]\n'.format(self.ncount, node.op.value) | |
| self.dot_body.append(s) | |
| node._num = self.ncount | |
| self.ncount += 1 | |
| self.visit(node.left) | |
| self.visit(node.right) | |
| for child_node in (node.left, node.right): | |
| s = ' node{} -> node{}\n'.format(node._num, child_node._num) | |
| self.dot_body.append(s) | |
| def visit_Var(self, node): | |
| s = ' node{} [label="{}"]\n'.format(self.ncount, node.value) | |
| self.dot_body.append(s) | |
| node._num = self.ncount | |
| self.ncount += 1 | |
| def visit_NoOp(self, node): | |
| s = ' node{} [label="NoOp"]\n'.format(self.ncount) | |
| self.dot_body.append(s) | |
| node._num = self.ncount | |
| self.ncount += 1 | |
| def gendot(self): | |
| tree = self.parser.parse() | |
| self.visit(tree) | |
| return ''.join(self.dot_header + self.dot_body + self.dot_footer) | |
| def main(): | |
| argparser = argparse.ArgumentParser( | |
| description='Generate an AST DOT file.' | |
| ) | |
| argparser.add_argument( | |
| 'fname', | |
| help='Pascal source file' | |
| ) | |
| args = argparser.parse_args() | |
| fname = args.fname | |
| text = open(fname, 'r').read() | |
| lexer = Lexer(text) | |
| parser = Parser(lexer) | |
| viz = ASTVisualizer(parser) | |
| content = viz.gendot() | |
| print(content) | |
| if __name__ == '__main__': | |
| main() |