add codegen MVP for online model overhead analysis

1 files changed, 80 insertions, 0 deletions

diff --git a/lib/codegen.py b/lib/codegen.py
new file mode 100644
index 0000000..d6dfe6e
--- /dev/null
+++ b/lib/codegen.py
@@ -0,0 +1,80 @@
+"""Code generators for multipass dummy drivers for online model evaluation."""
+
+header_template = """
+#ifndef DFATOOL_{name}_H
+#define DFATOOL_{name}_H
+
+class {name}
+{{
+private:
+{name}(const {name} &copy);
+
+public:
+{enums}
+{functions}
+}};
+
+extern {name} {name_lower};
+
+#endif
+"""
+
+implementation_template = """
+#include "driver/dummy.h"
+
+{functions}
+
+{name} {name_lower};
+"""
+
+class MultipassDriver:
+    """Generate C++ header and no-op implementation for a multipass driver based on a DFA model."""
+
+    def __init__(self, name, pta, class_info, enum = dict()):
+        self.impl = ''
+        self.header = ''
+        self.name = name
+        self.pta = pta
+        self.class_info = class_info
+        self.enum = enum
+
+        function_definitions = list()
+        function_bodies = list()
+
+        function_definitions.append('{}() {{}}'.format(self.name))
+        seen_transitions = set()
+
+        for transition in self.pta.transitions:
+            if transition.name in seen_transitions:
+                continue
+            seen_transitions.add(transition.name)
+
+            # XXX right now we only verify whether both functions have the
+            # same number of arguments. This breaks in many overloading cases.
+            function_info = self.class_info.function[transition.name]
+            function_arguments = list()
+
+            if len(transition.arguments) != len(function_info.argument_types):
+                # polymorphic function variant, TODO
+                pass
+
+            for i in range(len(transition.arguments)):
+                function_arguments.append('{} {}'.format(function_info.argument_types[i], transition.arguments[i]))
+
+            function_definition = '{} {}({})'.format(function_info.return_type, transition.name, ', '.join(function_arguments))
+            function_head = '{} {}::{}({})'.format(function_info.return_type, self.name, transition.name, ', '.join(function_arguments))
+
+            function_body = str()
+
+            if function_info.return_type != 'void':
+                function_body = 'return 0;\n'
+
+            function_definitions.append(function_definition + ';')
+            function_bodies.append('{} {{\n{}}}'.format(function_head, function_body))
+
+        enums = list()
+        for enum_name in self.enum.keys():
+            enums.append('enum {} {{ {} }};'.format(enum_name, ', '.join(self.enum[enum_name])))
+
+        self.header = header_template.format(name = self.name, name_lower = self.name.lower(), functions = '\n'.join(function_definitions), enums = '\n'.join(enums))
+        self.impl = implementation_template.format(name = self.name, name_lower = self.name.lower(), functions = '\n\n'.join(function_bodies))