Reimplement '%.3f' float formatting in C.

This was the only usage of dtoa.c / pystrtod.c.

spec/builtins.test.sh pass again under the OVM build.

core/cmd_exec.py

@@ -1085,9 +1085,7 @@ def _Dispatch(self, node, fork_external):
       real = end_t - start_t
       user = end_u.ru_utime - start_u.ru_utime
       sys_ = end_u.ru_stime - start_u.ru_stime
-      print('real\t%.3f' % real, file=sys.stderr)
-      print('user\t%.3f' % user, file=sys.stderr)
-      print('sys\t%.3f' % sys_, file=sys.stderr)
+      libc.print_time(real, user, sys_)
 
     else:
       raise NotImplementedError(node.__class__.__name__)

native/libc.c

@@ -338,6 +338,21 @@ func_regex_first_group_match(PyObject *self, PyObject *args) {
   return Py_BuildValue("(i,i)", pos + start, pos + end);
 }
 
+// We do this in C so we can remove '%f' % 0.1 from the CPython build.  That
+// involves dtoa.c and pystrod.c, which are thousands of lines of code.
+static PyObject *
+func_print_time(PyObject *self, PyObject *args) {
+  double real, user, sys;
+  int pos;
+  if (!PyArg_ParseTuple(args, "ddd", &real, &user, &sys)) {
+    return NULL;
+  }
+  fprintf(stderr, "real\t%.3f\n", real);
+  fprintf(stderr, "user\t%.3f\n",  user);
+  fprintf(stderr, "sys\t%.3f\n", sys);
+  Py_RETURN_NONE;
+}
+
 static PyMethodDef methods[] = {
   {"realpath", func_realpath, METH_VARARGS,
    "Return the canonical version of a path with symlinks, or None if there is "
@@ -350,12 +365,14 @@ static PyMethodDef methods[] = {
   {"regex_parse", func_regex_parse, METH_VARARGS,
    "Compile a regex in ERE syntax, returning whether it is valid"},
   {"regex_match", func_regex_match, METH_VARARGS,
-   "Match regex against a string.  Returns a list of matches, None if no match. "
-    "Raises RuntimeError if the regex is invalid."},
+   "Match regex against a string.  Returns a list of matches, None if no "
+   "match.  Raises RuntimeError if the regex is invalid."},
   {"regex_first_group_match", func_regex_first_group_match, METH_VARARGS,
    "If the regex matches the string, return the start and end position of the "
    "first group.  Returns None if there is no match.  Raises RuntimeError if "
    "the regex is invalid."},
+  {"print_time", func_print_time, METH_VARARGS,
+   "Print three floating point values for the 'time' builtin."},
   {NULL, NULL},
 };
 

native/libc_test.py

@@ -134,6 +134,9 @@ def testRealpathFailOnNonexistentDirectory(self):
     # Consistent with GNU
     self.assertEqual(None, libc.realpath('_tmp/nonexistent/supernonexistent'))
 
+  def testPrintTime(self):
+    libc.print_time(0.1, 0.2, 0.3)
+
 
 if __name__ == '__main__':
   unittest.main()