Compile the Cython.StringIOTree module by default to speed up the code generation a little.

Cython/StringIOTree.pxd

 cimport cython
 
+cdef object StringIO
+
+@cython.final
 cdef class StringIOTree:
     cdef public list prepended_children
     cdef public object stream
@@ -8,6 +11,8 @@ cdef class StringIOTree:
 
     @cython.locals(x=StringIOTree)
     cpdef getvalue(self)
+    @cython.locals(x=StringIOTree)
+    cdef _collect_in(self, list target_list)
     @cython.locals(child=StringIOTree)
     cpdef copyto(self, target)
     cpdef commit(self)

Cython/StringIOTree.py

@@ -39,7 +39,6 @@ try:
     from cStringIO import StringIO
 except ImportError:
     from io import StringIO
-import sys
 
 
 class StringIOTree(object):
@@ -56,10 +55,17 @@ class StringIOTree(object):
         self.markers = []
 
     def getvalue(self):
-        content = [x.getvalue() for x in self.prepended_children]
-        content.append(self.stream.getvalue())
+        content = []
+        self._collect_in(content)
         return "".join(content)
 
+    def _collect_in(self, target_list):
+        for x in self.prepended_children:
+            x._collect_in(target_list)
+        stream_content = self.stream.getvalue()
+        if stream_content:
+            target_list.append(stream_content)
+
     def copyto(self, target):
         """Potentially cheaper than getvalue as no string concatenation
         needs to happen."""
@@ -108,6 +114,7 @@ class StringIOTree(object):
         children = self.prepended_children
         return [m for c in children for m in c.allmarkers()] + self.markers
 
+    """
     # Print the result of allmarkers in a nice human-readable form. Use it only for debugging.
     # Prints e.g.
     # /path/to/source.pyx:
@@ -147,4 +154,7 @@ class StringIOTree(object):
                         reprstr += "-" + str(c_linenos[i]) + " "
                     i += 1
                 reprstr += "\n"
+
+        import sys
         sys.stdout.write(reprstr)
+    """

setup.py

@@ -93,10 +93,10 @@ def compile_cython_modules(profile=False, coverage=False, compile_more=False, cy
         "Cython.Runtime.refnanny",
         "Cython.Compiler.FusedNode",
         "Cython.Tempita._tempita",
+        "Cython.StringIOTree",
     ]
     if compile_more:
         compiled_modules.extend([
-            "Cython.StringIOTree",
             "Cython.Compiler.Code",
             "Cython.Compiler.Lexicon",
             "Cython.Compiler.Parsing",