manual: Convert errno @comments to new @errno macro.

errno.texi documents error macros, their values, and error strings in
Texinfo @comments, some of which are also used for @standards.  The
purpose of this commit is to separate the standards from the error
strings so that both the @standards conversion script picks up clean
@standards and the errno documentation framework is improved.

The error names, values, and messages are consolidated in a new custom
macro, @errno.  It is not clear that scripts within the sources rely
on the special Texinfo @comment-based format to generate files used
throughout the library, so the definition of @errno in macros.texi now
provides a comment indicating the dependency.  The dependent scripts
are updated to use @errno, which also simplifies them a bit.  The
files those scripts generate were verified to be unchanged.

The @errno macro is not visibly rendered in any way at this time, but
it does use an @cindex command to add the error string to the Concept
Index, to facilitate searching on error messages.

	* manual/errno.texi: Convert @comment-based errno
	documentation to @errno.
	* manual/macros.texi (@errno): New macro.  Consolidate errors,
	their values, and messages, adding the error string to the
	Concept Index.  Provide a warning in the comment about
	external (to the manual) dependencies.
	* sysdeps/gnu/errlist.awk: Use @errno instead of @comments.
	* sysdeps/mach/hurd/errnos.awk: Likewise.

ChangeLog

@@ -1,3 +1,14 @@
+2017-05-19  Rical Jasan  <ricaljasan@pacific.net>
+
+	* manual/errno.texi: Convert @comment-based errno documentation to
+	@errno.
+	* manual/macros.texi (@errno): New macro.  Consolidate errors,
+	their values, and messages, adding the error string to the Concept
+	Index.  Provide a warning in the comment about external (to the
+	manual) dependencies.
+	* sysdeps/gnu/errlist.awk: Use @errno instead of @comments.
+	* sysdeps/mach/hurd/errnos.awk: Likewise.
+
 2017-05-19  Joseph Myers  <joseph@codesourcery.com>
 
 	* bits/ss_flags.h: New file.

manual/macros.texi

@@ -267,4 +267,10 @@ cwd\comments\
 @end macro
 @end ifnottex
 
+@c Used by errlist.awk and errnos.awk to generate other files.
+@c Note that error values have ABI implications for the Hurd.
+@macro errno {err, val, str}
+@cindex \str\
+@end macro
+
 @end ifclear

sysdeps/gnu/errlist.awk

@@ -16,10 +16,8 @@
 # <http://www.gnu.org/licenses/>.
 
 # errno.texi contains lines like:
-# @comment errno.h
-# @comment POSIX.1: Function not implemented
 # @deftypevr Macro int ENOSYS
-# @comment errno 78
+# @errno{ENOSYS, 78, Function not implemented}
 # Descriptive paragraph...
 # @end deftypevr
 
@@ -61,22 +59,14 @@ BEGIN {
     print "    [0] = N_(\"Success\"),"
   }
 
-$1 == "@comment" && $2 == "errno.h" { errnoh=1; next }
+/^@errno\{/ \
-errnoh == 1 && $1 == "@comment" \
   {
-    ++errnoh;
     etext = $3;
     for (i = 4; i <= NF; ++i)
       etext = etext " " $i;
-    next;
+    etext = substr(etext, 1, length(etext)-1)
-  }
+    e = substr($1, 8, length($1)-8)
-errnoh == 2 && $1 == "@deftypevr" && $2 == "Macro" && $3 == "int" \
+    errno = substr($2, 1, length($2)-1) + 0
-  {
-    e = $4; errnoh++; next;
-  }
-errnoh == 3 && $1 == "@comment" && $2 == "errno" \
-  {
-    errno = $3 + 0;
     if (alias[e])
       printf "#if defined (%s) && %s != %s\n", e, e, alias[e];
     else
@@ -102,7 +92,6 @@ errnoh == 4 \
     # This magic tag in C comments gets them copied into libc.pot.
     desc = desc "\nTRANS" ($0 != "" ? " " : "") $0; next
   }
-{ errnoh=0 }
 END {
   print "  };";
   print "";

sysdeps/mach/hurd/errnos.awk

@@ -16,10 +16,7 @@
 # <http://www.gnu.org/licenses/>.
 
 # errno.texinfo contains lines like:
-# @comment errno.h
+# @errno{ENOSYS, 123, Function not implemented}
-# @comment POSIX.1: Function not implemented
-# @deftypevr Macro int ENOSYS
-# @comment errno 123
 
 BEGIN {
     print "/* This file generated by errnos.awk.  */";
@@ -39,7 +36,6 @@ BEGIN {
     print "\t   value.  */";
     print "\tESUCCESS = 0,"
     print "";
-    errnoh = 0;
     maxerrno = 0;
     in_mach_errors = "";
     in_math = 0;
@@ -48,26 +44,21 @@ BEGIN {
     lno = 0;
   }
 
-$1 == "@comment" && $2 == "errno.h" { errnoh=1; next }
+/^@errno\{/ \
-$1 == "@comment" && errnoh == 1 \
   {
-    ++errnoh;
     etext = "";
     for (i = 3; i <= NF; ++i)
       etext = etext " " $i;
-    next;
+    etext = substr(etext, 1, length(etext)-1)
-  }
 
-errnoh == 2 && $1 == "@deftypevr"  && $2 == "Macro" && $3 == "int" \
+    e = substr($1, 8, length($1)-8)
-  { ++errnoh; e = $4; next; }
-
-errnoh == 3 && $1 == "@comment" && $2 == "errno" {
     if (e == "EWOULDBLOCK")
       {
 	lines[lno++]="#define EWOULDBLOCK EAGAIN /* Operation would block */";
 	next;
       }
-    errno = $3 + 0;
+
+    errno = substr($2, 1, length($2)-1) + 0
     if (errno == 0)
       next;
     if (errno > maxerrno) maxerrno = errno;
@@ -83,7 +74,6 @@ errnoh == 3 && $1 == "@comment" && $2 == "errno" {
     lines[lno++] = x;
     next;
   }
-{ errnoh=0 }
 
 NF == 3 && $1 == "#define" && $2 == "MACH_SEND_IN_PROGRESS" \
   {