signal: Move sys_errlist to a compat symbol

The symbol is deprecated by strerror since its usage imposes some issues
such as copy relocations.

Its internal name is also changed to _sys_errlist_internal to avoid
static linking usage.  The compat code is also refactored by removing
the over enginered errlist-compat.c generation from manual entried and
extra comment token in linker script file.  It disantangle the code
generation from manual and simplify both Linux and Hurd compat code.

The definitions from errlist.c are moved to errlist.h and a new test
is added to avoid a new errno entry without an associated one in manual.

Checked on x86_64-linux-gnu and i686-linux-gnu. I also run a check-abi
on all affected platforms.

Tested-by: Carlos O'Donell <carlos@redhat.com>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>

11 files changed, 215 insertions, 62 deletions

diff --git a/sysdeps/unix/sysv/linux/Versions b/sysdeps/unix/sysv/linux/Versions
index 52ca223ab2..f72741b7e5 100644
--- a/sysdeps/unix/sysv/linux/Versions
+++ b/sysdeps/unix/sysv/linux/Versions
@@ -1,9 +1,4 @@
 libc {
-  # The comment lines with "#errlist-compat" are magic; see errlist-compat.awk.
-  # When you get an error from errlist-compat.awk, you need to add a new
-  # version here.  Don't do this blindly, since this means changing the ABI
-  # for all GNU/Linux configurations.
-
   GLIBC_2.0 {
     # functions used in inline functions or macros
     __cmsg_nxthdr;
@@ -56,7 +51,6 @@ libc {
     # u*
     umount; uselib;
 
-    #errlist-compat	123
     _sys_errlist; sys_errlist; _sys_nerr; sys_nerr;
   }
   GLIBC_2.1 {
@@ -84,7 +78,6 @@ libc {
     # u*
     umount2;
 
-    #errlist-compat	125
     _sys_errlist; sys_errlist; _sys_nerr; sys_nerr;
   }
   GLIBC_2.2 {
@@ -102,7 +95,6 @@ libc {
     # r*
     readahead;
 
-    #errlist-compat	126
     _sys_errlist; sys_errlist; _sys_nerr; sys_nerr;
   }
   GLIBC_2.3.2 {
@@ -120,7 +112,6 @@ libc {
 
     unshare;
 
-    #errlist-compat	132
     _sys_errlist; sys_errlist; _sys_nerr; sys_nerr;
   }
   GLIBC_2.5 {
@@ -142,7 +133,6 @@ libc {
     fallocate;
   }
   GLIBC_2.12 {
-    #errlist-compat	135
     _sys_errlist; sys_errlist; _sys_nerr; sys_nerr;
 
     ntp_gettimex;
diff --git a/sysdeps/unix/sysv/linux/alpha/Versions b/sysdeps/unix/sysv/linux/alpha/Versions
index 3b7971c2a3..b90d5f2e5a 100644
--- a/sysdeps/unix/sysv/linux/alpha/Versions
+++ b/sysdeps/unix/sysv/linux/alpha/Versions
@@ -1,12 +1,5 @@
 libc {
-  # The comment lines with "#errlist-compat" are magic; see
-  # sysdeps/gnu/errlist-compat.awk.
-  # When you get an error from errlist-compat.awk, you need to add a new
-  # version here.  Don't do this blindly, since this means changing the ABI
-  # for all GNU/Linux configurations.
-
   GLIBC_2.0 {
-    #errlist-compat	131
     _sys_errlist; sys_errlist; _sys_nerr; sys_nerr;
 
     # Unfortunately in wider use.
@@ -33,7 +26,6 @@ libc {
     pciconfig_read; pciconfig_write; sethae;
   }
   GLIBC_2.1 {
-    #errlist-compat	131
     _sys_errlist; sys_errlist; _sys_nerr; sys_nerr;
 
     # Linux/Alpha 64-bit timeval functions.
@@ -70,19 +62,15 @@ libc {
     wordexp;
   }
   GLIBC_2.3 {
-    #errlist-compat	132
     _sys_errlist; sys_errlist; _sys_nerr; sys_nerr;
   }
   GLIBC_2.4 {
-    #errlist-compat	138
     _sys_errlist; sys_errlist; _sys_nerr; sys_nerr;
   }
   GLIBC_2.12 {
-    #errlist-compat	139
     _sys_errlist; sys_errlist; _sys_nerr; sys_nerr;
   }
   GLIBC_2.16 {
-    #errlist-compat	140
     _sys_errlist; sys_errlist; _sys_nerr; sys_nerr;
   }
   GLIBC_2.27 {
diff --git a/sysdeps/unix/sysv/linux/alpha/errlist-compat.c b/sysdeps/unix/sysv/linux/alpha/errlist-compat.c
new file mode 100644
index 0000000000..709807aa6b
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/alpha/errlist-compat.c
@@ -0,0 +1,43 @@
+/* Linux sys_errlist compat symbol definitions.  Alpha version.
+   Copyright (C) 2020 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
+   <https://www.gnu.org/licenses/>.  */
+
+#include <errlist-compat.h>
+
+#if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_1)
+DEFINE_COMPAT_ERRLIST (131, GLIBC_2_0)
+#endif
+
+#if SHLIB_COMPAT (libc, GLIBC_2_1, GLIBC_2_3)
+DEFINE_COMPAT_ERRLIST (131, GLIBC_2_1)
+#endif
+
+#if SHLIB_COMPAT (libc, GLIBC_2_3, GLIBC_2_4)
+DEFINE_COMPAT_ERRLIST (132, GLIBC_2_3)
+#endif
+
+#if SHLIB_COMPAT (libc, GLIBC_2_4, GLIBC_2_12)
+DEFINE_COMPAT_ERRLIST (138, GLIBC_2_4)
+#endif
+
+#if SHLIB_COMPAT (libc, GLIBC_2_12, GLIBC_2_16)
+DEFINE_COMPAT_ERRLIST (139, GLIBC_2_12)
+#endif
+
+#if SHLIB_COMPAT (libc, GLIBC_2_16, GLIBC_2_32)
+DEFINE_COMPAT_ERRLIST (140, GLIBC_2_16)
+#endif
diff --git a/sysdeps/unix/sysv/linux/errlist-compat.c b/sysdeps/unix/sysv/linux/errlist-compat.c
new file mode 100644
index 0000000000..c4d79b70aa
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/errlist-compat.c
@@ -0,0 +1,39 @@
+/* Linux sys_errlist compat symbol definitions.  Generic version.
+   Copyright (C) 2020 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
+   <https://www.gnu.org/licenses/>.  */
+
+#include <errlist-compat.h>
+
+#if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_1)
+DEFINE_COMPAT_ERRLIST (123, GLIBC_2_0)
+#endif
+
+#if SHLIB_COMPAT (libc, GLIBC_2_1, GLIBC_2_3)
+DEFINE_COMPAT_ERRLIST (125, GLIBC_2_1)
+#endif
+
+#if SHLIB_COMPAT (libc, GLIBC_2_3, GLIBC_2_4)
+DEFINE_COMPAT_ERRLIST (126, GLIBC_2_3)
+#endif
+
+#if SHLIB_COMPAT (libc, GLIBC_2_4, GLIBC_2_12)
+DEFINE_COMPAT_ERRLIST (132, GLIBC_2_4)
+#endif
+
+#if SHLIB_COMPAT (libc, GLIBC_2_12, GLIBC_2_32)
+DEFINE_COMPAT_ERRLIST (135, GLIBC_2_12)
+#endif
diff --git a/sysdeps/unix/sysv/linux/errlist-compat.h b/sysdeps/unix/sysv/linux/errlist-compat.h
new file mode 100644
index 0000000000..edd35fd4ed
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/errlist-compat.h
@@ -0,0 +1,43 @@
+/* Linux sys_errlist compatibility macro definitions.
+   Copyright (C) 2020 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
+   <https://www.gnu.org/licenses/>.  */
+
+#ifndef _ERRLIST_COMPAT_H
+#define _ERRLIST_COMPAT_H
+
+#include <shlib-compat.h>
+
+/* Define new compat symbols for symbols  _sys_errlist, sys_errlist,
+   _sys_nerr, and sys_nerr for version VERSION with NUMBERERR times number of
+   bytes per long int size.
+   Both _sys_errlist and sys_errlist alias to _sys_errlist_internal symbol
+   (defined on errlist.c) while _sys_nerr and sys_nerr created new variable
+   with the expected size.  */
+#define DEFINE_COMPAT_ERRLIST(NUMBERERR, VERSION) 			     \
+  const int __##VERSION##_sys_nerr = NUMBERERR;				     \
+  strong_alias (__##VERSION##_sys_nerr, __##VERSION##__sys_nerr); 	     \
+  declare_symbol_alias (__ ## VERSION ## _sys_errlist, _sys_errlist_internal,\
+			object, NUMBERERR * (ULONG_WIDTH / UCHAR_WIDTH));    \
+  declare_symbol_alias (__ ## VERSION ## __sys_errlist,			     \
+			_sys_errlist_internal, object,			     \
+			NUMBERERR * (ULONG_WIDTH / UCHAR_WIDTH));	     \
+  compat_symbol (libc, __## VERSION ## _sys_nerr, sys_nerr, VERSION);	     \
+  compat_symbol (libc, __## VERSION ## __sys_nerr, _sys_nerr, VERSION);      \
+  compat_symbol (libc, __## VERSION ## _sys_errlist, sys_errlist, VERSION);  \
+  compat_symbol (libc, __## VERSION ## __sys_errlist, _sys_errlist, VERSION);\
+
+#endif
diff --git a/sysdeps/unix/sysv/linux/hppa/Versions b/sysdeps/unix/sysv/linux/hppa/Versions
index b5098b2171..9532d207fc 100644
--- a/sysdeps/unix/sysv/linux/hppa/Versions
+++ b/sysdeps/unix/sysv/linux/hppa/Versions
@@ -1,11 +1,5 @@
 libc {
-  # The comment lines with "#errlist-compat" are magic; see errlist-compat.awk.
-  # When you get an error from errlist-compat.awk, you need to add a new
-  # version here.  Don't do this blindly, since this means changing the ABI
-  # for all GNU/Linux configurations.
-
   GLIBC_2.1 {
-    #errlist-compat	253
     _sys_errlist; sys_errlist; _sys_nerr; sys_nerr;
   }
   GLIBC_2.2 {
@@ -13,22 +7,18 @@ libc {
     getrlimit; setrlimit; getrlimit64; setrlimit64;
   }
   GLIBC_2.3 {
-    #errlist-compat	254
     _sys_errlist; sys_errlist; _sys_nerr; sys_nerr;
   }
   GLIBC_2.4 {
-    #errlist-compat	256
     _sys_errlist; sys_errlist; _sys_nerr; sys_nerr;
   }
   GLIBC_2.11 {
     fallocate64;
   }
   GLIBC_2.12 {
-    #errlist-compat	257
     _sys_errlist; sys_errlist; _sys_nerr; sys_nerr;
   }
   GLIBC_2.17 {
-    #errlist-compat	260
     _sys_errlist; sys_errlist; _sys_nerr; sys_nerr;
     prlimit64;
   }
diff --git a/sysdeps/unix/sysv/linux/hppa/errlist-compat.c b/sysdeps/unix/sysv/linux/hppa/errlist-compat.c
new file mode 100644
index 0000000000..65860d884c
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/hppa/errlist-compat.c
@@ -0,0 +1,39 @@
+/* Linux sys_errlist compat symbol definitions.  HPPA version.
+   Copyright (C) 2020 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
+   <https://www.gnu.org/licenses/>.  */
+
+#include <errlist-compat.h>
+
+#if SHLIB_COMPAT (libc, GLIBC_2_1, GLIBC_2_3)
+DEFINE_COMPAT_ERRLIST (253, GLIBC_2_1)
+#endif
+
+#if SHLIB_COMPAT (libc, GLIBC_2_3, GLIBC_2_4)
+DEFINE_COMPAT_ERRLIST (254, GLIBC_2_3)
+#endif
+
+#if SHLIB_COMPAT (libc, GLIBC_2_4, GLIBC_2_12)
+DEFINE_COMPAT_ERRLIST (256, GLIBC_2_4)
+#endif
+
+#if SHLIB_COMPAT (libc, GLIBC_2_12, GLIBC_2_17)
+DEFINE_COMPAT_ERRLIST (257, GLIBC_2_12)
+#endif
+
+#if SHLIB_COMPAT (libc, GLIBC_2_17, GLIBC_2_32)
+DEFINE_COMPAT_ERRLIST (260, GLIBC_2_17)
+#endif
diff --git a/sysdeps/unix/sysv/linux/mips/Versions b/sysdeps/unix/sysv/linux/mips/Versions
index 453f276aad..0ec82dc480 100644
--- a/sysdeps/unix/sysv/linux/mips/Versions
+++ b/sysdeps/unix/sysv/linux/mips/Versions
@@ -5,13 +5,7 @@ ld {
   }
 }
 libc {
-  # The comment lines with "#errlist-compat" are magic; see errlist-compat.awk.
-  # When you get an error from errlist-compat.awk, you need to add a new
-  # version here.  Don't do this blindly, since this means changing the ABI
-  # for all GNU/Linux configurations.
-
   GLIBC_2.0 {
-    #errlist-compat	123
     _sys_errlist; sys_errlist; _sys_nerr; sys_nerr;
 
     # Exception handling support functions from libgcc
@@ -28,7 +22,6 @@ libc {
     sysmips;
   }
   GLIBC_2.2 {
-    #errlist-compat	1134
     _sys_errlist; sys_errlist; _sys_nerr; sys_nerr;
 
     # _*
diff --git a/sysdeps/unix/sysv/linux/bits/sys_errlist.h b/sysdeps/unix/sysv/linux/mips/errlist-compat.c
index d6f5fa0a5e..b720db9244 100644
--- a/sysdeps/unix/sysv/linux/bits/sys_errlist.h
+++ b/sysdeps/unix/sysv/linux/mips/errlist-compat.c
@@ -1,5 +1,5 @@
-/* Declare sys_errlist and sys_nerr, or don't.  Compatibility (do) version.
-   Copyright (C) 2002-2020 Free Software Foundation, Inc.
+/* Linux sys_errlist compat symbol definitions.  MIPS version.
+   Copyright (C) 2020 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
@@ -16,17 +16,12 @@
    License along with the GNU C Library; if not, see
    <https://www.gnu.org/licenses/>.  */
 
-#ifndef _STDIO_H
-# error "Never include <bits/sys_errlist.h> directly; use <stdio.h> instead."
-#endif
-
-/* sys_errlist and sys_nerr are deprecated.  Use strerror instead.  */
+#include <errlist-compat.h>
 
-#ifdef  __USE_MISC
-extern int sys_nerr;
-extern const char *const sys_errlist[];
+#if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_2)
+DEFINE_COMPAT_ERRLIST (123, GLIBC_2_0)
 #endif
-#ifdef  __USE_GNU
-extern int _sys_nerr;
-extern const char *const _sys_errlist[];
+
+#if SHLIB_COMPAT (libc, GLIBC_2_2, GLIBC_2_32)
+DEFINE_COMPAT_ERRLIST (1134, GLIBC_2_1)
 #endif
diff --git a/sysdeps/unix/sysv/linux/sparc/Versions b/sysdeps/unix/sysv/linux/sparc/Versions
index f056addee6..61e57fae99 100644
--- a/sysdeps/unix/sysv/linux/sparc/Versions
+++ b/sysdeps/unix/sysv/linux/sparc/Versions
@@ -1,30 +1,20 @@
 libc {
-  # The comment lines with "#errlist-compat" are magic; see errlist-compat.awk.
-  # When you get an error from errlist-compat.awk, you need to add a new
-  # version here.
-
   GLIBC_2.0 {
-    #errlist-compat	127
     _sys_errlist; sys_errlist; _sys_nerr; sys_nerr;
   }
   GLIBC_2.1 {
-    #errlist-compat	127
     _sys_errlist; sys_errlist; _sys_nerr; sys_nerr;
   }
   GLIBC_2.3 {
-    #errlist-compat	128
     _sys_errlist; sys_errlist; _sys_nerr; sys_nerr;
   }
   GLIBC_2.4 {
-    #errlist-compat	134
     _sys_errlist; sys_errlist; _sys_nerr; sys_nerr;
   }
   GLIBC_2.12 {
-    #errlist-compat	135
     _sys_errlist; sys_errlist; _sys_nerr; sys_nerr;
   }
   GLIBC_2.16 {
-    #errlist-compat	136
     _sys_errlist; sys_errlist; _sys_nerr; sys_nerr;
 
     __getshmlba;
diff --git a/sysdeps/unix/sysv/linux/sparc/errlist-compat.c b/sysdeps/unix/sysv/linux/sparc/errlist-compat.c
new file mode 100644
index 0000000000..43fc364add
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/sparc/errlist-compat.c
@@ -0,0 +1,43 @@
+/* Linux sys_errlist compat symbol definitions.  Sparc version.
+   Copyright (C) 2020 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
+   <https://www.gnu.org/licenses/>.  */
+
+#include <errlist-compat.h>
+
+#if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_1)
+DEFINE_COMPAT_ERRLIST (127, GLIBC_2_0)
+#endif
+
+#if SHLIB_COMPAT (libc, GLIBC_2_1, GLIBC_2_3)
+DEFINE_COMPAT_ERRLIST (127, GLIBC_2_1)
+#endif
+
+#if SHLIB_COMPAT (libc, GLIBC_2_3, GLIBC_2_4)
+DEFINE_COMPAT_ERRLIST (128, GLIBC_2_3)
+#endif
+
+#if SHLIB_COMPAT (libc, GLIBC_2_4, GLIBC_2_12)
+DEFINE_COMPAT_ERRLIST (134, GLIBC_2_4)
+#endif
+
+#if SHLIB_COMPAT (libc, GLIBC_2_12, GLIBC_2_16)
+DEFINE_COMPAT_ERRLIST (135, GLIBC_2_12)
+#endif
+
+#if SHLIB_COMPAT (libc, GLIBC_2_16, GLIBC_2_32)
+DEFINE_COMPAT_ERRLIST (136, GLIBC_2_16)
+#endif