Sync support files from GNULIB.

11 files changed, 64 insertions, 27 deletions

diff --git a/support/ChangeLog b/support/ChangeLog
index 035a719f..5a6c4342 100644
--- a/support/ChangeLog
+++ b/support/ChangeLog
@@ -1,3 +1,9 @@
+2020-07-26         Arnold D. Robbins     <arnold@skeeve.com>
+
+	* cdefs.h, dfa.c, libc-config.h, localeinfo.c, localeinfo.h,
+	regcomp.c, regex.h, regex_internal.c, regexec.c,
+	verify.h: Sync from GNULIB. Mostly copyright updates.
+
 2020-06-07         Arnold D. Robbins     <arnold@skeeve.com>
 
 	* dfa.c: Revert changes of 26 April 2020. It causes
diff --git a/support/cdefs.h b/support/cdefs.h
index 4f921754..21583795 100644
--- a/support/cdefs.h
+++ b/support/cdefs.h
@@ -1,4 +1,4 @@
-/* Copyright (C) 1992-2019 Free Software Foundation, Inc.
+/* Copyright (C) 1992-2020 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
diff --git a/support/dfa.c b/support/dfa.c
index 41bf5cc2..3327f627 100644
--- a/support/dfa.c
+++ b/support/dfa.c
@@ -2465,7 +2465,7 @@ static int
 compare (const void *a, const void *b)
 {
   position const *p = a, *q = b;
-  return p->index < q->index ? -1 : p->index > q->index;
+  return (p->index > q->index) - (p->index < q->index);
 }
 
 static void
diff --git a/support/libc-config.h b/support/libc-config.h
index f24fbfa6..59cfbe5c 100644
--- a/support/libc-config.h
+++ b/support/libc-config.h
@@ -1,6 +1,6 @@
 /* System definitions for code taken from the GNU C Library
 
-   Copyright 2017-2019 Free Software Foundation, Inc.
+   Copyright 2017-2020 Free Software Foundation, Inc.
 
    This program is free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
@@ -55,8 +55,17 @@
 
 #ifndef __glibc_clang_prereq
 # if defined __clang_major__ && defined __clang_minor__
-#  define __glibc_clang_prereq(maj, min) \
-     ((maj) < __clang_major__ + ((min) <= __clang_minor__))
+#  ifdef __apple_build_version__
+/* Apple for some reason renumbers __clang_major__ and __clang_minor__.
+   Gnulib code uses only __glibc_clang_prereq (3, 5); map it to
+   6000000 <= __apple_build_version__.  Support for other calls to
+   __glibc_clang_prereq can be added here as needed.  */
+#   define __glibc_clang_prereq(maj, min) \
+      ((maj) == 3 && (min) == 5 ? 6000000 <= __apple_build_version__ : 0)
+#  else
+#   define __glibc_clang_prereq(maj, min) \
+      ((maj) < __clang_major__ + ((min) <= __clang_minor__))
+#  endif
 # else
 #  define __glibc_clang_prereq(maj, min) 0
 # endif
@@ -171,4 +180,5 @@
 
 /* A substitute for glibc <shlib-compat.h>, good enough for Gnulib.  */
 #define SHLIB_COMPAT(lib, introduced, obsoleted) 0
-#define versioned_symbol(lib, local, symbol, version)
+#define compat_symbol(lib, local, symbol, version) extern int dummy
+#define versioned_symbol(lib, local, symbol, version) extern int dummy
diff --git a/support/localeinfo.c b/support/localeinfo.c
index 694735e2..159ad073 100644
--- a/support/localeinfo.c
+++ b/support/localeinfo.c
@@ -1,6 +1,6 @@
 /* locale information
 
-   Copyright 2016-2019 Free Software Foundation, Inc.
+   Copyright 2016-2020 Free Software Foundation, Inc.
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -81,7 +81,7 @@ using_simple_locale (bool multibyte)
      where the native order is the collating-sequence order but there
      are multi-character collating elements.  */
   for (int i = 0; i < UCHAR_MAX; i++)
-    if (strcoll (((char []) {i, 0}), ((char []) {i + 1, 0})) <= 0)
+    if (0 <= strcoll (((char []) {i, 0}), ((char []) {i + 1, 0})))
       return false;
 
   return true;
diff --git a/support/localeinfo.h b/support/localeinfo.h
index c827a2bf..16f5129d 100644
--- a/support/localeinfo.h
+++ b/support/localeinfo.h
@@ -1,6 +1,6 @@
 /* locale information
 
-   Copyright 2016-2019 Free Software Foundation, Inc.
+   Copyright 2016-2020 Free Software Foundation, Inc.
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
diff --git a/support/regcomp.c b/support/regcomp.c
index 3e8f1e61..93bb0a05 100644
--- a/support/regcomp.c
+++ b/support/regcomp.c
@@ -1,5 +1,5 @@
 /* Extended regular expression matching and search library.
-   Copyright (C) 2002-2019 Free Software Foundation, Inc.
+   Copyright (C) 2002-2020 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
    Contributed by Isamu Hasegawa <isamu@yamato.ibm.com>.
 
diff --git a/support/regex.h b/support/regex.h
index 840e5150..87cce7f5 100644
--- a/support/regex.h
+++ b/support/regex.h
@@ -1,6 +1,6 @@
 /* Definitions for data structures and routines for the regular
    expression library.
-   Copyright (C) 1985, 1989-2019 Free Software Foundation, Inc.
+   Copyright (C) 1985, 1989-2020 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
diff --git a/support/regex_internal.c b/support/regex_internal.c
index 6aa91160..e1b6b4d5 100644
--- a/support/regex_internal.c
+++ b/support/regex_internal.c
@@ -1,5 +1,5 @@
 /* Extended regular expression matching and search library.
-   Copyright (C) 2002-2019 Free Software Foundation, Inc.
+   Copyright (C) 2002-2020 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
    Contributed by Isamu Hasegawa <isamu@yamato.ibm.com>.
 
diff --git a/support/regexec.c b/support/regexec.c
index 38b6d671..a3ee618c 100644
--- a/support/regexec.c
+++ b/support/regexec.c
@@ -1,5 +1,5 @@
 /* Extended regular expression matching and search library.
-   Copyright (C) 2002-2019 Free Software Foundation, Inc.
+   Copyright (C) 2002-2020 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
    Contributed by Isamu Hasegawa <isamu@yamato.ibm.com>.
 
diff --git a/support/verify.h b/support/verify.h
index afdc1ad8..f1097612 100644
--- a/support/verify.h
+++ b/support/verify.h
@@ -1,6 +1,6 @@
 /* Compile-time assert-like macros.
 
-   Copyright (C) 2005-2006, 2009-2019 Free Software Foundation, Inc.
+   Copyright (C) 2005-2006, 2009-2020 Free Software Foundation, Inc.
 
    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -233,6 +233,22 @@ template <int w>
 
 /* @assert.h omit start@  */
 
+#if 3 < __GNUC__ + (3 < __GNUC_MINOR__ + (4 <= __GNUC_PATCHLEVEL__))
+# define _GL_HAS_BUILTIN_TRAP 1
+#elif defined __has_builtin
+# define _GL_HAS_BUILTIN_TRAP __has_builtin (__builtin_trap)
+#else
+# define _GL_HAS_BUILTIN_TRAP 0
+#endif
+
+#if 4 < __GNUC__ + (5 <= __GNUC_MINOR__)
+# define _GL_HAS_BUILTIN_UNREACHABLE 1
+#elif defined __has_builtin
+# define _GL_HAS_BUILTIN_UNREACHABLE __has_builtin (__builtin_unreachable)
+#else
+# define _GL_HAS_BUILTIN_UNREACHABLE 0
+#endif
+
 /* Each of these macros verifies that its argument R is nonzero.  To
    be portable, R should be an integer constant expression.  Unlike
    assert (R), there is no run-time overhead.
@@ -260,24 +276,29 @@ template <int w>
 # define verify(R) _GL_VERIFY (R, "verify (" #R ")", -)
 #endif
 
-#ifndef __has_builtin
-# define __has_builtin(x) 0
-#endif
-
 /* Assume that R always holds.  Behavior is undefined if R is false,
-   fails to evaluate, or has side effects.  Although assuming R can
-   help a compiler generate better code or diagnostics, performance
-   can suffer if R uses hard-to-optimize features such as function
-   calls not inlined by the compiler.  */
+   fails to evaluate, or has side effects.
+
+   'assume (R)' is a directive from the programmer telling the
+   compiler that R is true so the compiler needn't generate code to
+   test R.  This is why 'assume' is in verify.h: it's related to
+   static checking (in this case, static checking done by the
+   programmer), not dynamic checking.
+
+   'assume (R)' can affect compilation of all the code, not just code
+   that happens to be executed after the assume (R) is "executed".
+   For example, if the code mistakenly does 'assert (R); assume (R);'
+   the compiler is entitled to optimize away the 'assert (R)'.
+
+   Although assuming R can help a compiler generate better code or
+   diagnostics, performance can suffer if R uses hard-to-optimize
+   features such as function calls not inlined by the compiler.  */
 
-#if (__has_builtin (__builtin_unreachable) \
-     || 4 < __GNUC__ + (5 <= __GNUC_MINOR__))
+#if _GL_HAS_BUILTIN_UNREACHABLE
 # define assume(R) ((R) ? (void) 0 : __builtin_unreachable ())
 #elif 1200 <= _MSC_VER
 # define assume(R) __assume (R)
-#elif ((defined GCC_LINT || defined lint) \
-       && (__has_builtin (__builtin_trap) \
-           || 3 < __GNUC__ + (3 < __GNUC_MINOR__ + (4 <= __GNUC_PATCHLEVEL__))))
+#elif (defined GCC_LINT || defined lint) && _GL_HAS_BUILTIN_TRAP
   /* Doing it this way helps various packages when configured with
      --enable-gcc-warnings, which compiles with -Dlint.  It's nicer
      when 'assume' silences warnings even with older GCCs.  */