diff --git a/.gitignore b/.gitignore
index cb3aafe..336e33d 100644
--- a/.gitignore
+++ b/.gitignore
@@ -6,3 +6,10 @@ a.out
 # Generated by Cython:
 optpass.c
 tree.c
+
+# Generated elsewhere in build:
+tree-types.txt
+tree-types.pyx.in
+tree.pyx
+
+
diff --git a/Makefile b/Makefile
index bb702f6..b1a2eca 100644
--- a/Makefile
+++ b/Makefile
@@ -30,9 +30,15 @@ optpass.c: optpass.pyx
 tree.c: tree.pyx
 	cython $^ -o $@
 
-tree.pyx: tree.pyx.in
+tree.pyx: tree.pyx.in tree-types.pyx.in
+	cpp $(CFLAGS) tree.pyx.in -o $@
+
+tree-types.txt: tree-types.txt.in
 	cpp $(CFLAGS) $^ -o $@
 
+tree-types.pyx.in: tree-types.txt maketreetypes.py
+	python maketreetypes.py > tree-types.pyx.in
+
 # Hint for debugging: add -v to the gcc options 
 # to get a command line for invoking individual subprocesses
 # Doing so seems to require that paths be absolute, rather than relative
diff --git a/maketreetypes.py b/maketreetypes.py
new file mode 100644
index 0000000..06d2d7f
--- /dev/null
+++ b/maketreetypes.py
@@ -0,0 +1,34 @@
+from collections import namedtuple
+
+class TreeType(namedtuple('TreeType', 'SYM, STRING, TYPE, NARGS')):
+    def camel_cased_string(self):
+        return ''.join([word.title()
+                        for word in self.STRING.split('_')])
+
+def iter_tree_types():
+    import re
+    f = open('tree-types.txt')
+    for line in f:
+        # e.g.
+        #   ERROR_MARK, "error_mark", tcc_exceptional, 0
+        m = re.match('(.+), (.+), (.+), (.+)', line)
+        if m:
+            yield TreeType(SYM=m.group(1),
+                           STRING=m.group(2)[1:-1],
+                           TYPE=m.group(3),
+                           NARGS=int(m.group(4)))
+        else:
+            #    print 'UNMATCHED: ', line
+            assert(line.startswith('#') or line.strip() == '')
+    f.close()
+
+for t in iter_tree_types():
+    print (
+"""
+cdef class %s(Tree):
+    _STRING = %r
+    _SYM = %r
+    _TYPE = %r
+    _NARGS = %i
+""" % (t.camel_cased_string(),
+       t.STRING, t.SYM, t.TYPE, t.NARGS))
diff --git a/tree-types.txt.in b/tree-types.txt.in
new file mode 100644
index 0000000..3a1d477
--- /dev/null
+++ b/tree-types.txt.in
@@ -0,0 +1,5 @@
+#define DEFTREECODE(SYM, STRING, TYPE, NARGS)   \
+   SYM, STRING, TYPE, NARGS
+#define END_OF_BASE_TREE_CODES
+#include "all-tree.def"
+#undef DEFTREECODE
diff --git a/tree.pyx.in b/tree.pyx.in
index 0effc46..30a84c8 100644
--- a/tree.pyx.in
+++ b/tree.pyx.in
@@ -32,13 +32,7 @@ cdef class Tree:
     def __repr__(self):
         return 'tree.Tree(%r)' % 'foo'
 
-
-#define DEFTREECODE(SYM, STRING, TYPE, NARGS)   \
-cdef class SYM(Tree): \
-     pass
-#define END_OF_BASE_TREE_CODES
-#include "all-tree.def"
-#undef DEFTREECODE
+#include "tree-types.pyx.in"
 
 cdef extern gcc_python_make_wrapper_tree(tree t):
     obj = Tree()