3 files changed, 158 insertions, 0 deletions
diff --git a/crowbar_reference_compiler/__init__.py b/crowbar_reference_compiler/__init__.py
index 7c7fca7..02fcfc1 100644
--- a/crowbar_reference_compiler/__init__.py
+++ b/crowbar_reference_compiler/__init__.py
@@ -1,2 +1,3 @@
 from .parser import parse_header, parse_implementation
 from .scanner import scan
+from .ssagen import compile_to_ssa
diff --git a/crowbar_reference_compiler/ssagen.py b/crowbar_reference_compiler/ssagen.py
new file mode 100644
index 0000000..7cb8861
--- /dev/null
+++ b/crowbar_reference_compiler/ssagen.py
@@ -0,0 +1,125 @@
+from parsimonious import NodeVisitor
+from parsimonious.nodes import Node
+
+
+class SsaGenVisitor(NodeVisitor):
+    def __init__(self):
+        self.data = []
+
+    def visit_ImplementationFile(self, node, visited_children):
+        data = '\n'.join(self.data)
+        functions = '\n'.join(visited_children)
+        return data + '\n' + functions
+
+    def visit_IncludeStatement(self, node, visited_children):
+        include, included_header, semicolon = visited_children
+        assert include.text[0].type == 'include'
+        assert included_header.type == 'string_literal'
+        included_header = included_header.data
+        assert semicolon.text[0].type == ';'
+        print("including", included_header)
+        return ''
+
+    def visit_FunctionDefinition(self, node, visited_children):
+        signature, body = visited_children
+        return_type, name, args = signature
+        body = '\n'.join('    ' + instr for instr in body)
+        return f"export function w ${name}() {{\n@start\n{body}\n}}"
+
+    def visit_FunctionSignature(self, node, visited_children):
+        return_type, name, lparen, args, rparen = visited_children
+        assert name.type == 'identifier'
+        name = name.data
+        assert lparen.text[0].type == '('
+        assert rparen.text[0].type == ')'
+        return return_type, name, args
+
+    def visit_Block(self, node, visited_children):
+        lbrace, statements, rbrace = visited_children
+        return statements
+
+    def visit_Statement(self, node, visited_children):
+        return visited_children[0]
+
+    def visit_ExpressionStatement(self, node, visited_children):
+        expression, semicolon = visited_children
+        assert semicolon.text[0].type == ';'
+        return expression
+
+    def visit_Expression(self, node, visited_children):
+        # TODO handle logical and/or
+        return visited_children[0]
+
+    def visit_ComparisonExpression(self, node, visited_children):
+        # TODO handle comparisons
+        return visited_children[0]
+
+    def visit_BitwiseOpExpression(self, node, visited_children):
+        # TODO handle bitwise operations
+        return visited_children[0]
+
+    def visit_ArithmeticExpression(self, node, visited_children):
+        # TODO handle addition/subtraction
+        return visited_children[0]
+
+    def visit_TermExpression(self, node, visited_children):
+        # TODO handle multiplication/division/modulus
+        return visited_children[0]
+
+    def visit_FactorExpression(self, node, visited_children):
+        # TODO handle casts/address-of/pointer-dereference/unary ops/sizeof
+        return visited_children[0]
+
+    def visit_ObjectExpression(self, node, visited_children):
+        # TODO handle array literals
+        # TODO handle struct literals
+        base, suffices = visited_children[0]
+        if isinstance(suffices, Node):
+            suffices = suffices.children
+        if len(suffices) == 0:
+            return base
+        if base.type == 'identifier' and suffices[0].text[0].type == '(':
+            arguments = suffices[1]
+            if arguments[0].type == 'string_literal':
+                data = arguments[0].data
+                name = f"$data{len(self.data)}"
+                # TODO handle non-variadic functions
+                arguments = [f"l {name}", '...']
+                self.data.append(f"data {name} = {{ b {data}, b 0 }}")
+            return f"call ${base.data}({', '.join(arguments)})"
+        print(base)
+        print(suffices[0])
+
+    def visit_AtomicExpression(self, node, visited_children):
+        # TODO handle parenthesized subexpressions
+        return visited_children[0]
+
+    def visit_FlowControlStatement(self, node, visited_children):
+        # TODO handle break/continue
+        ret, arg, semicolon = visited_children[0]
+        assert ret.text[0].type == 'return'
+        assert semicolon.text[0].type == ';'
+        if arg.type == 'constant':
+            return f"ret {arg.data}"
+
+    def visit_constant(self, node, visited_children):
+        return node.text[0]
+
+    def visit_string_literal(self, node, visited_children):
+        return node.text[0]
+
+    def visit_identifier(self, node, visited_children):
+        return node.text[0]
+
+    def generic_visit(self, node, visited_children):
+        """ The generic visit method. """
+        if not visited_children:
+            return node
+        if len(visited_children) == 1:
+            return visited_children[0]
+        return visited_children
+
+
+def compile_to_ssa(parse_tree):
+    ssa_gen = SsaGenVisitor()
+    return ssa_gen.visit(parse_tree)
diff --git a/tests/test_hello_world.py b/tests/test_hello_world.py
new file mode 100644
index 0000000..ec1ccdd
--- /dev/null
+++ b/tests/test_hello_world.py
@@ -0,0 +1,32 @@
+import unittest
+
+from crowbar_reference_compiler import compile_to_ssa, parse_header, parse_implementation, scan
+
+
+class TestHelloWorld(unittest.TestCase):
+    def test_ssa(self):
+        code = r"""
+include "stdio.hro";
+
+int main() {
+    printf("Hello, world!\n");
+    return 0;
+}
+"""
+        tokens = scan(code)
+        parse_tree = parse_implementation(tokens)
+        actual_ssa = compile_to_ssa(parse_tree)
+        expected_ssa = r"""
+data $data0 = { b "Hello, world!\n", b 0 }
+
+export function w $main() {
+@start
+    call $printf(l $data0, ...)
+    ret 0
+}
+""".strip()
+        self.assertEqual(expected_ssa, actual_ssa)
+
+
+if __name__ == '__main__':
+    unittest.main()