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.

2 files changed, 90 insertions, 0 deletions

diff --git a/sysdeps/mach/hurd/Makefile b/sysdeps/mach/hurd/Makefile
index 13bdf5c7c9..5171425650 100644
--- a/sysdeps/mach/hurd/Makefile
+++ b/sysdeps/mach/hurd/Makefile
@@ -98,6 +98,16 @@ $(common-objpfx)stamp-errnos: $(hurd)/errnos.awk $(errno.texinfo) \
 	touch $@
 
 common-generated += errnos.d stamp-errnos
+
+# Augmentations to the errno pretty-printer.
+ifeq ($(subdir),stdlib)
+define sysd-add-errno-constants
+$(AWK) -f $(hurd)/hurd-add-errno-constants.awk $(mach-errnos-deps)
+endef
+$(objpfx)errno_constants.pysym: \
+    $(hurd)/hurd-add-errno-constants.awk $(mach-errnos-deps)
+endif
+
 
 # We install the real libc.a as libcrt.a and as libc.a we install a linker
 # script which does -( -lcrt -lmachuser -lhurduser -).
diff --git a/sysdeps/mach/hurd/hurd-add-errno-constants.awk b/sysdeps/mach/hurd/hurd-add-errno-constants.awk
new file mode 100644
index 0000000000..0d51766c97
--- /dev/null
+++ b/sysdeps/mach/hurd/hurd-add-errno-constants.awk
@@ -0,0 +1,80 @@
+# Add Hurd-specific constants to errno_constants.pysym.
+# 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/>.
+
+# On the Hurd, errno.h defines E-constants corresponding to a number of
+# Mach low-level errors.  Add these to the set of values recognized by
+# stdlib/errno-printer.py.  This script must be kept in sync with errnos.awk.
+
+BEGIN {
+  in_mach_errors = "";
+  in_mig_errors = 0;
+  in_device_errors = 0;
+}
+
+function emit_subhead()
+{
+  header = FILENAME;
+  sub(/.*include\//, "", header);
+  printf("\n-- Errors from <%s>\n", header);
+}
+
+NF == 3 && $1 == "#define" && $2 == "MACH_SEND_IN_PROGRESS" \
+  {
+    in_mach_errors = FILENAME;
+    emit_subhead();
+  }
+NF == 3 && $1 == "#define" && $2 == "KERN_SUCCESS" \
+  {
+    in_mach_errors = FILENAME;
+    emit_subhead();
+    next;
+  }
+in_mach_errors != "" && $2 == "MACH_IPC_COMPAT" \
+  {
+    in_mach_errors = "";
+    next;
+  }
+
+$1 == "#define" && $2 == "_MACH_MIG_ERRORS_H_" \
+  {
+    in_mig_errors = 1;
+    emit_subhead();
+    next;
+  }
+in_mig_errors && $1 == "#endif" && $3 == "_MACH_MIG_ERRORS_H_" \
+  {
+    in_mig_errors = 0;
+  }
+
+$1 == "#define" && $2 == "D_SUCCESS" \
+  {
+    in_device_errors = 1;
+    emit_subhead();
+    next;
+  }
+in_device_errors && $1 == "#endif" \
+  {
+    in_device_errors = 0;
+  }
+
+(in_mach_errors == FILENAME && NF == 3 && $1 == "#define") || \
+(in_mig_errors && $1 == "#define" && $3 <= -300) || \
+(in_device_errors && $1 == "#define" && $2 ~ /D_/ && NF > 3) \
+  {
+    print "E" $2;
+  }