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, 58 insertions, 0 deletions

diff --git a/stdlib/test-errno-constants.py b/stdlib/test-errno-constants.py
new file mode 100644
index 0000000000..a79df97625
--- /dev/null
+++ b/stdlib/test-errno-constants.py
@@ -0,0 +1,58 @@
+# Test that errno_constants.py includes every error number defined by errno.h.
+# 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/>.
+
+# Usage: test-errno-constants.py $(common-objpfx)stdlib $(CC) $(CFLAGS) $(CPPFLAGS)
+
+import os
+import sys
+import subprocess
+
+sys.path.append(sys.argv[1])
+import errno_constants
+
+def main():
+    cc_cmd = sys.argv[2:]
+    cc_cmd.extend(["-E", "-dM", "-xc", "-"])
+    cc_proc = subprocess.Popen(cc_cmd,
+                               stdin=subprocess.PIPE,
+                               stdout=subprocess.PIPE)
+    cc_proc.stdin.write(b"#define _GNU_SOURCE\n"
+                       b"#include <errno.h>\n")
+    cc_proc.stdin.close()
+
+    cc_output = cc_proc.stdout.read()
+    status = cc_proc.wait()
+    if status:
+        sys.stderr.write("{}\nunsuccessful exit, status {:04x}"
+                         .format(" ".join(cc_cmd), status))
+        sys.exit(1)
+
+    ok = True
+    for line in cc_output.decode("utf-8").splitlines():
+        if not line.startswith("#define E"):
+            continue
+        emacro = line.split()[1]
+        if not hasattr(errno_constants, emacro):
+            if ok:
+                sys.stderr.write("*** Missing constants:\n")
+                ok = False
+            sys.stderr.write(emacro + "\n")
+
+    sys.exit(0 if ok else 1)
+
+main()