master 3e10174: Update from Gnulib

[Paul Eggert]

branch: master
commit 3e10174fb65f4eb601b1921271bdcf10c933b879
Author: Paul Eggert <eggert@cs.ucla.edu>
Commit: Paul Eggert <eggert@cs.ucla.edu>

    Update from Gnulib
    
    This incorporates:
    2020-08-20 sigabbrev_np: New module
    2020-08-20 stdalign: Fix 32-bit test failures clang versions < 8
    2020-08-17 careadlinkat: speedup for GCC 10 with GCC_LINT
    2020-08-17 Assume autoconf >= 2.64
    * build-aux/config.guess, build-aux/config.sub, lib/careadlinkat.c:
    * lib/stdalign.in.h, lib/string.in.h, m4/std-gnu11.m4, m4/string_h.m4:
    Copy from Gnulib.
    * lib/gnulib.mk.in: Regenerate.
---
 build-aux/config.guess |  28 ++++++-------
 build-aux/config.sub   |   4 +-
 lib/careadlinkat.c     | 108 ++++++++++++++++++++++++++++---------------------
 lib/gnulib.mk.in       |   4 ++
 lib/stdalign.in.h      |   6 ++-
 lib/string.in.h        |  15 +++++++
 m4/std-gnu11.m4        |   4 +-
 m4/string_h.m4         |   6 ++-
 8 files changed, 107 insertions(+), 68 deletions(-)

diff --git a/build-aux/config.guess b/build-aux/config.guess
index e94095c..9aff91c 100755
--- a/build-aux/config.guess
+++ b/build-aux/config.guess
@@ -2,7 +2,7 @@
 # Attempt to guess a canonical system name.
 #   Copyright 1992-2020 Free Software Foundation, Inc.
 
-timestamp='2020-07-12'
+timestamp='2020-08-17'
 
 # This file is free software; you can redistribute it and/or modify it
 # under the terms of the GNU General Public License as published by
@@ -404,7 +404,7 @@ case 
"$UNAME_MACHINE:$UNAME_SYSTEM:$UNAME_RELEASE:$UNAME_VERSION" in
        # If there is a compiler, see if it is configured for 64-bit objects.
        # Note that the Sun cc does not turn __LP64__ into 1 like gcc does.
        # This test works for both compilers.
-       if [ "$CC_FOR_BUILD" != no_compiler_found ]; then
+       if test "$CC_FOR_BUILD" != no_compiler_found; then
            if (echo '#ifdef __amd64'; echo IS_64BIT_ARCH; echo '#endif') | \
                (CCOPTS="" $CC_FOR_BUILD -E - 2>/dev/null) | \
                grep IS_64BIT_ARCH >/dev/null
@@ -544,10 +544,10 @@ EOF
     AViiON:dgux:*:*)
        # DG/UX returns AViiON for all architectures
        UNAME_PROCESSOR=`/usr/bin/uname -p`
-       if [ "$UNAME_PROCESSOR" = mc88100 ] || [ "$UNAME_PROCESSOR" = mc88110 ]
+       if test "$UNAME_PROCESSOR" = mc88100 || test "$UNAME_PROCESSOR" = 
mc88110
        then
-           if [ "$TARGET_BINARY_INTERFACE"x = m88kdguxelfx ] || \
-              [ "$TARGET_BINARY_INTERFACE"x = x ]
+           if test "$TARGET_BINARY_INTERFACE"x = m88kdguxelfx || \
+              test "$TARGET_BINARY_INTERFACE"x = x
            then
                echo m88k-dg-dgux"$UNAME_RELEASE"
            else
@@ -580,7 +580,7 @@ EOF
        echo i386-ibm-aix
        exit ;;
     ia64:AIX:*:*)
-       if [ -x /usr/bin/oslevel ] ; then
+       if test -x /usr/bin/oslevel ; then
                IBM_REV=`/usr/bin/oslevel`
        else
                IBM_REV="$UNAME_VERSION.$UNAME_RELEASE"
@@ -620,7 +620,7 @@ EOF
        else
                IBM_ARCH=powerpc
        fi
-       if [ -x /usr/bin/lslpp ] ; then
+       if test -x /usr/bin/lslpp ; then
                IBM_REV=`/usr/bin/lslpp -Lqc bos.rte.libc |
                           awk -F: '{ print $3 }' | sed s/[0-9]*$/0/`
        else
@@ -655,7 +655,7 @@ EOF
            9000/31?)            HP_ARCH=m68000 ;;
            9000/[34]??)         HP_ARCH=m68k ;;
            9000/[678][0-9][0-9])
-               if [ -x /usr/bin/getconf ]; then
+               if test -x /usr/bin/getconf; then
                    sc_cpu_version=`/usr/bin/getconf SC_CPU_VERSION 2>/dev/null`
                    sc_kernel_bits=`/usr/bin/getconf SC_KERNEL_BITS 2>/dev/null`
                    case "$sc_cpu_version" in
@@ -669,7 +669,7 @@ EOF
                        esac ;;
                    esac
                fi
-               if [ "$HP_ARCH" = "" ]; then
+               if test "$HP_ARCH" = ""; then
                    set_cc_for_build
                    sed 's/^            //' << EOF > "$dummy.c"
 
@@ -708,7 +708,7 @@ EOF
                    test -z "$HP_ARCH" && HP_ARCH=hppa
                fi ;;
        esac
-       if [ "$HP_ARCH" = hppa2.0w ]
+       if test "$HP_ARCH" = hppa2.0w
        then
            set_cc_for_build
 
@@ -782,7 +782,7 @@ EOF
        echo hppa1.0-hp-osf
        exit ;;
     i*86:OSF1:*:*)
-       if [ -x /usr/sbin/sysversion ] ; then
+       if test -x /usr/sbin/sysversion ; then
            echo "$UNAME_MACHINE"-unknown-osf1mk
        else
            echo "$UNAME_MACHINE"-unknown-osf1
@@ -1097,7 +1097,7 @@ EOF
     x86_64:Linux:*:*)
        set_cc_for_build
        LIBCABI=$LIBC
-       if [ "$CC_FOR_BUILD" != no_compiler_found ]; then
+       if test "$CC_FOR_BUILD" != no_compiler_found; then
            if (echo '#ifdef __ILP32__'; echo IS_X32; echo '#endif') | \
                (CCOPTS="" $CC_FOR_BUILD -E - 2>/dev/null) | \
                grep IS_X32 >/dev/null
@@ -1294,7 +1294,7 @@ EOF
        echo mips-sony-newsos6
        exit ;;
     R[34]000:*System_V*:*:* | R4000:UNIX_SYSV:*:* | R*000:UNIX_SV:*:*)
-       if [ -d /usr/nec ]; then
+       if test -d /usr/nec; then
                echo mips-nec-sysv"$UNAME_RELEASE"
        else
                echo mips-unknown-sysv"$UNAME_RELEASE"
@@ -1359,7 +1359,7 @@ EOF
        else
            set_cc_for_build
        fi
-       if [ "$CC_FOR_BUILD" != no_compiler_found ]; then
+       if test "$CC_FOR_BUILD" != no_compiler_found; then
            if (echo '#ifdef __LP64__'; echo IS_64BIT_ARCH; echo '#endif') | \
                   (CCOPTS="" $CC_FOR_BUILD -E - 2>/dev/null) | \
                   grep IS_64BIT_ARCH >/dev/null
diff --git a/build-aux/config.sub b/build-aux/config.sub
index 3d9a8dc..0753e30 100755
--- a/build-aux/config.sub
+++ b/build-aux/config.sub
@@ -2,7 +2,7 @@
 # Configuration validation subroutine script.
 #   Copyright 1992-2020 Free Software Foundation, Inc.
 
-timestamp='2020-07-10'
+timestamp='2020-08-17'
 
 # This file is free software; you can redistribute it and/or modify it
 # under the terms of the GNU General Public License as published by
@@ -1278,7 +1278,7 @@ esac
 
 # Decode manufacturer-specific aliases for certain operating systems.
 
-if [ x$basic_os != x ]
+if test x$basic_os != x
 then
 
 # First recognize some ad-hoc caes, or perhaps split kernel-os, or else just
diff --git a/lib/careadlinkat.c b/lib/careadlinkat.c
index 1aa0436..e43aa42 100644
--- a/lib/careadlinkat.c
+++ b/lib/careadlinkat.c
@@ -38,66 +38,41 @@
 
 #include "allocator.h"
 
-/* Assuming the current directory is FD, get the symbolic link value
-   of FILENAME as a null-terminated string and put it into a buffer.
-   If FD is AT_FDCWD, FILENAME is interpreted relative to the current
-   working directory, as in openat.
-
-   If the link is small enough to fit into BUFFER put it there.
-   BUFFER's size is BUFFER_SIZE, and BUFFER can be null
-   if BUFFER_SIZE is zero.
-
-   If the link is not small, put it into a dynamically allocated
-   buffer managed by ALLOC.  It is the caller's responsibility to free
-   the returned value if it is nonnull and is not BUFFER.  A null
-   ALLOC stands for the standard allocator.
-
-   The PREADLINKAT function specifies how to read links.  It operates
-   like POSIX readlinkat()
-   <https://pubs.opengroup.org/onlinepubs/9699919799/functions/readlink.html>
-   but can assume that its first argument is the same as FD.
-
-   If successful, return the buffer address; otherwise return NULL and
-   set errno.  */
-
-char *
-careadlinkat (int fd, char const *filename,
+enum { STACK_BUF_SIZE = 1024 };
+
+/* Act like careadlinkat (see below), with an additional argument
+   STACK_BUF that can be used as temporary storage.
+
+   If GCC_LINT is defined, do not inline this function with GCC 10.1
+   and later, to avoid creating a pointer to the stack that GCC
+   -Wreturn-local-addr incorrectly complains about.  See:
+   https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93644
+   Although the noinline attribute can hurt performance a bit, no better way
+   to pacify GCC is known; even an explicit #pragma does not pacify GCC.
+   When the GCC bug is fixed this workaround should be limited to the
+   broken GCC versions.  */
+#if (defined GCC_LINT || defined lint) && _GL_GNUC_PREREQ (10, 1)
+__attribute__ ((__noinline__))
+#endif
+static char *
+readlink_stk (int fd, char const *filename,
               char *buffer, size_t buffer_size,
               struct allocator const *alloc,
-              ssize_t (*preadlinkat) (int, char const *, char *, size_t))
+              ssize_t (*preadlinkat) (int, char const *, char *, size_t),
+              char stack_buf[STACK_BUF_SIZE])
 {
   char *buf;
   size_t buf_size;
   size_t buf_size_max =
     SSIZE_MAX < SIZE_MAX ? (size_t) SSIZE_MAX + 1 : SIZE_MAX;
-  char stack_buf[1024];
-
-#if (defined GCC_LINT || defined lint) && _GL_GNUC_PREREQ (10, 1)
-  /* Pacify preadlinkat without creating a pointer to the stack
-     that a broken gcc -Wreturn-local-addr would cry wolf about.  See:
-     https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95044
-     This workaround differs from the mainline code, but
-     no other way to pacify GCC 10.1.0 is known; even an explicit
-     #pragma does not pacify GCC.  When the GCC bug is fixed this
-     workaround should be limited to the broken GCC versions.  */
-# define WORK_AROUND_GCC_BUG_95044
-#endif
 
   if (! alloc)
     alloc = &stdlib_allocator;
 
   if (!buffer)
     {
-#ifdef WORK_AROUND_GCC_BUG_95044
-      buffer = alloc->allocate (sizeof stack_buf);
-#else
-      /* Allocate the initial buffer on the stack.  This way, in the
-         common case of a symlink of small size, we get away with a
-         single small malloc() instead of a big malloc() followed by a
-         shrinking realloc().  */
       buffer = stack_buf;
-#endif
-      buffer_size = sizeof stack_buf;
+      buffer_size = STACK_BUF_SIZE;
     }
 
   buf = buffer;
@@ -172,3 +147,44 @@ careadlinkat (int fd, char const *filename,
   errno = ENOMEM;
   return NULL;
 }
+
+
+/* Assuming the current directory is FD, get the symbolic link value
+   of FILENAME as a null-terminated string and put it into a buffer.
+   If FD is AT_FDCWD, FILENAME is interpreted relative to the current
+   working directory, as in openat.
+
+   If the link is small enough to fit into BUFFER put it there.
+   BUFFER's size is BUFFER_SIZE, and BUFFER can be null
+   if BUFFER_SIZE is zero.
+
+   If the link is not small, put it into a dynamically allocated
+   buffer managed by ALLOC.  It is the caller's responsibility to free
+   the returned value if it is nonnull and is not BUFFER.  A null
+   ALLOC stands for the standard allocator.
+
+   The PREADLINKAT function specifies how to read links.  It operates
+   like POSIX readlinkat()
+   <https://pubs.opengroup.org/onlinepubs/9699919799/functions/readlink.html>
+   but can assume that its first argument is the same as FD.
+
+   If successful, return the buffer address; otherwise return NULL and
+   set errno.  */
+
+char *
+careadlinkat (int fd, char const *filename,
+              char *buffer, size_t buffer_size,
+              struct allocator const *alloc,
+              ssize_t (*preadlinkat) (int, char const *, char *, size_t))
+{
+  /* Allocate the initial buffer on the stack.  This way, in the
+     common case of a symlink of small size, we get away with a
+     single small malloc instead of a big malloc followed by a
+     shrinking realloc.
+
+     If GCC -Wreturn-local-addr warns about this buffer, the warning
+     is bogus; see readlink_stk.  */
+  char stack_buf[STACK_BUF_SIZE];
+  return readlink_stk (fd, filename, buffer, buffer_size, alloc,
+                       preadlinkat, stack_buf);
+}
diff --git a/lib/gnulib.mk.in b/lib/gnulib.mk.in
index 7b4fc74..78b4542 100644
--- a/lib/gnulib.mk.in
+++ b/lib/gnulib.mk.in
@@ -424,6 +424,7 @@ GNULIB_SECURE_GETENV = @GNULIB_SECURE_GETENV@
 GNULIB_SELECT = @GNULIB_SELECT@
 GNULIB_SETENV = @GNULIB_SETENV@
 GNULIB_SETHOSTNAME = @GNULIB_SETHOSTNAME@
+GNULIB_SIGABBREV_NP = @GNULIB_SIGABBREV_NP@
 GNULIB_SIGACTION = @GNULIB_SIGACTION@
 GNULIB_SIGNAL_H_SIGPIPE = @GNULIB_SIGNAL_H_SIGPIPE@
 GNULIB_SIGPROCMASK = @GNULIB_SIGPROCMASK@
@@ -644,6 +645,7 @@ HAVE_SECURE_GETENV = @HAVE_SECURE_GETENV@
 HAVE_SETENV = @HAVE_SETENV@
 HAVE_SETHOSTNAME = @HAVE_SETHOSTNAME@
 HAVE_SETSTATE = @HAVE_SETSTATE@
+HAVE_SIGABBREV_NP = @HAVE_SIGABBREV_NP@
 HAVE_SIGACTION = @HAVE_SIGACTION@
 HAVE_SIGHANDLER_T = @HAVE_SIGHANDLER_T@
 HAVE_SIGINFO_T = @HAVE_SIGINFO_T@
@@ -2843,6 +2845,7 @@ string.h: string.in.h $(top_builddir)/config.status 
$(CXXDEFS_H) $(ARG_NONNULL_H
              -e 's/@''GNULIB_STRTOK_R''@/$(GNULIB_STRTOK_R)/g' \
              -e 's/@''GNULIB_STRERROR''@/$(GNULIB_STRERROR)/g' \
              -e 's/@''GNULIB_STRERROR_R''@/$(GNULIB_STRERROR_R)/g' \
+             -e 's/@''GNULIB_SIGABBREV_NP''@/$(GNULIB_SIGABBREV_NP)/g' \
              -e 's/@''GNULIB_STRSIGNAL''@/$(GNULIB_STRSIGNAL)/g' \
              -e 's/@''GNULIB_STRVERSCMP''@/$(GNULIB_STRVERSCMP)/g' \
              < $(srcdir)/string.in.h | \
@@ -2865,6 +2868,7 @@ string.h: string.in.h $(top_builddir)/config.status 
$(CXXDEFS_H) $(ARG_NONNULL_H
              -e 's|@''HAVE_STRCASESTR''@|$(HAVE_STRCASESTR)|g' \
              -e 's|@''HAVE_DECL_STRTOK_R''@|$(HAVE_DECL_STRTOK_R)|g' \
              -e 's|@''HAVE_DECL_STRERROR_R''@|$(HAVE_DECL_STRERROR_R)|g' \
+             -e 's|@''HAVE_SIGABBREV_NP''@|$(HAVE_SIGABBREV_NP)|g' \
              -e 's|@''HAVE_DECL_STRSIGNAL''@|$(HAVE_DECL_STRSIGNAL)|g' \
              -e 's|@''HAVE_STRVERSCMP''@|$(HAVE_STRVERSCMP)|g' \
              -e 's|@''REPLACE_MEMCHR''@|$(REPLACE_MEMCHR)|g' \
diff --git a/lib/stdalign.in.h b/lib/stdalign.in.h
index e4809b4..b5b63e5 100644
--- a/lib/stdalign.in.h
+++ b/lib/stdalign.in.h
@@ -54,10 +54,12 @@
 #undef _Alignof
 
 /* GCC releases before GCC 4.9 had a bug in _Alignof.  See GCC bug 52023
-   <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=52023>.  */
+   <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=52023>.
+   clang versions < 8.0.0 have the same bug.  */
 #if (!defined __STDC_VERSION__ || __STDC_VERSION__ < 201112 \
      || (defined __GNUC__ && __GNUC__ < 4 + (__GNUC_MINOR__ < 9) \
-         && !defined __clang__))
+         && !defined __clang__) \
+     || (defined __clang__ && __clang_major__ < 8))
 # ifdef __cplusplus
 #  if 201103 <= __cplusplus
 #   define _Alignof(type) alignof (type)
diff --git a/lib/string.in.h b/lib/string.in.h
index 7d83668..5134e11 100644
--- a/lib/string.in.h
+++ b/lib/string.in.h
@@ -1045,6 +1045,21 @@ _GL_WARN_ON_USE (strerror_r, "strerror_r is unportable - 
"
 # endif
 #endif
 
+/* Return an abbreviation string for the signal number SIG.  */
+#if @GNULIB_SIGABBREV_NP@
+# if ! @HAVE_SIGABBREV_NP@
+_GL_FUNCDECL_SYS (sigabbrev_np, const char *, (int sig));
+# endif
+_GL_CXXALIAS_SYS (sigabbrev_np, const char *, (int sig));
+_GL_CXXALIASWARN (sigabbrev_np);
+#elif defined GNULIB_POSIXCHECK
+# undef sigabbrev_np
+# if HAVE_RAW_DECL_SIGABBREV_NP
+_GL_WARN_ON_USE (sigabbrev_np, "sigabbrev_np is unportable - "
+                 "use gnulib module sigabbrev_np for portability");
+# endif
+#endif
+
 #if @GNULIB_STRSIGNAL@
 # if @REPLACE_STRSIGNAL@
 #  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
diff --git a/m4/std-gnu11.m4 b/m4/std-gnu11.m4
index c1ec624..db833d8 100644
--- a/m4/std-gnu11.m4
+++ b/m4/std-gnu11.m4
@@ -70,7 +70,7 @@ _AS_ECHO_LOG([checking for _AC_LANG compiler version])
 set X $ac_compile
 ac_compiler=$[2]
 for ac_option in --version -v -V -qversion -version; do
-  m4_ifdef([_AC_DO_LIMIT],[_AC_DO_LIMIT],[_AC_DO])([$ac_compiler $ac_option 
>&AS_MESSAGE_LOG_FD])
+  _AC_DO_LIMIT([$ac_compiler $ac_option >&AS_MESSAGE_LOG_FD])
 done
 
 m4_expand_once([_AC_COMPILER_EXEEXT])[]dnl
@@ -135,7 +135,7 @@ _AS_ECHO_LOG([checking for _AC_LANG compiler version])
 set X $ac_compile
 ac_compiler=$[2]
 for ac_option in --version -v -V -qversion; do
-  m4_ifdef([_AC_DO_LIMIT],[_AC_DO_LIMIT],[_AC_DO])([$ac_compiler $ac_option 
>&AS_MESSAGE_LOG_FD])
+  _AC_DO_LIMIT([$ac_compiler $ac_option >&AS_MESSAGE_LOG_FD])
 done
 
 m4_expand_once([_AC_COMPILER_EXEEXT])[]dnl
diff --git a/m4/string_h.m4 b/m4/string_h.m4
index 516b346..d519bea 100644
--- a/m4/string_h.m4
+++ b/m4/string_h.m4
@@ -5,7 +5,7 @@
 # gives unlimited permission to copy and/or distribute it,
 # with or without modifications, as long as this notice is preserved.
 
-# serial 24
+# serial 25
 
 # Written by Paul Eggert.
 
@@ -28,7 +28,7 @@ AC_DEFUN([gl_HEADER_STRING_H_BODY],
     ]],
     [ffsl ffsll memmem mempcpy memrchr rawmemchr stpcpy stpncpy strchrnul
      strdup strncat strndup strnlen strpbrk strsep strcasestr strtok_r
-     strerror_r strsignal strverscmp])
+     strerror_r sigabbrev_np strsignal strverscmp])
 
   AC_REQUIRE([AC_C_RESTRICT])
 ])
@@ -80,6 +80,7 @@ AC_DEFUN([gl_HEADER_STRING_H_DEFAULTS],
   GNULIB_MBSTOK_R=0;    AC_SUBST([GNULIB_MBSTOK_R])
   GNULIB_STRERROR=0;    AC_SUBST([GNULIB_STRERROR])
   GNULIB_STRERROR_R=0;  AC_SUBST([GNULIB_STRERROR_R])
+  GNULIB_SIGABBREV_NP=0;AC_SUBST([GNULIB_SIGABBREV_NP])
   GNULIB_STRSIGNAL=0;   AC_SUBST([GNULIB_STRSIGNAL])
   GNULIB_STRVERSCMP=0;  AC_SUBST([GNULIB_STRVERSCMP])
   HAVE_MBSLEN=0;        AC_SUBST([HAVE_MBSLEN])
@@ -102,6 +103,7 @@ AC_DEFUN([gl_HEADER_STRING_H_DEFAULTS],
   HAVE_STRCASESTR=1;            AC_SUBST([HAVE_STRCASESTR])
   HAVE_DECL_STRTOK_R=1;         AC_SUBST([HAVE_DECL_STRTOK_R])
   HAVE_DECL_STRERROR_R=1;       AC_SUBST([HAVE_DECL_STRERROR_R])
+  HAVE_SIGABBREV_NP=1;          AC_SUBST([HAVE_SIGABBREV_NP])
   HAVE_DECL_STRSIGNAL=1;        AC_SUBST([HAVE_DECL_STRSIGNAL])
   HAVE_STRVERSCMP=1;            AC_SUBST([HAVE_STRVERSCMP])
   REPLACE_MEMCHR=0;             AC_SUBST([REPLACE_MEMCHR])