Add pretty-printer for errno.zack/errno-prettyprint

This patch adds the actual pretty-printer for errno.  I could have
used Python's built-in errno module to get the symbolic names for the
constants, but it seemed better to do something entirely under our
control, so there's a .pysym file generated from errnos.texi, with a
hook that allows the Hurd to add additional constants.  Then a .py
module is generated from that plus errno.h in the usual manner; many
thanks to the authors of the .pysym mechanism.

There is also a test which verifies that the .py file (not the .pysym
file) covers all of the constants defined in errno.h.

hurd-add-errno-constants.awk has been manually tested, but the
makefile logic that runs it has not been tested.

	* stdlib/errno-printer.py: New pretty-printer.
	* stdlib/test-errno-constants.py: New special test.
	* stdlib/test-errno-printer.c, stdlib/test-errno-printer.py:
	New pretty-printer test.
	* stdlib/make-errno-constants.awk: New script to generate the
	.pysym file needed by errno-printer.py.
	* stdlib/Makefile: Install, run, and test all of the above, as
	appropriate.

	* sysdeps/mach/hurd/hurd-add-errno-constants.awk: New script to
	add Mach/Hurd-specific errno constants to the .pysym file used by
	stdlib/errno-printer.py.
	* sysdeps/mach/hurd/Makefile: Hook hurd-add-errno-constants.awk
	into the generation of that .pysym file.

1 files changed, 43 insertions, 0 deletions

diff --git a/stdlib/test-errno-printer.c b/stdlib/test-errno-printer.c
new file mode 100644
index 0000000..da2345f
--- /dev/null
+++ b/stdlib/test-errno-printer.c
@@ -0,0 +1,43 @@
+/* Helper program for testing the errno pretty-printer.
+   Copyright (C) 2017 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#define _GNU_SOURCE 1
+#include <errno.h>
+#include <stdlib.h>
+#include <limits.h>
+
+#define PASS 0
+#define FAIL 1
+
+const error_t array_of_error_t[3] = { 0, ERANGE, -2 };
+
+__thread int ensure_gdb_can_read_thread_variables = 0;
+
+int
+main (void)
+{
+  int result = PASS;
+  errno = array_of_error_t[0];
+  unsigned long x = strtoul("9999999999999999999999999999999999999", 0, 10);
+  if (x != ULONG_MAX)
+    result = FAIL;
+  if (errno != ERANGE)
+    result = FAIL;
+  errno = -2; /* Break: test errno 2 */
+  return result;
+}