Update from Gnulib

This incorporates:
2019-05-24 flexmember: update comments
2019-05-18 pthread_sigmask: fix --enable-threads=windows compilation
2019-05-14 close-stream, closein, closeout: simplify
2019-05-09 verify: remove verify_true
2019-05-09 verify: support C2X and C++17 static_assert
* build-aux/config.guess, build-aux/config.sub:
* doc/misc/texinfo.tex, lib/flexmember.h, lib/verify.h:
* m4/flexmember.m4, m4/pthread_sigmask.m4:
Copy from Gnulib
* m4/gnulib-comp.m4: Regenerate.

2019-05-26  Paul Eggert  <eggert@cs.ucla.edu>

Update author/maintainer info
This mostly updates email addresses and fixes spellings of
author and maintainer names.

2 files changed, 76 insertions, 59 deletions

diff --git a/lib/flexmember.h b/lib/flexmember.h
index 0d65f6da60f..af17b41d29f 100644
--- a/lib/flexmember.h
+++ b/lib/flexmember.h
@@ -33,11 +33,26 @@
 # define FLEXALIGNOF(type) _Alignof (type)
 #endif
 
-/* Upper bound on the size of a struct of type TYPE with a flexible
-   array member named MEMBER that is followed by N bytes of other data.
-   This is not simply sizeof (TYPE) + N, since it may require
-   alignment on unusually picky C11 platforms, and
-   FLEXIBLE_ARRAY_MEMBER may be 1 on pre-C11 platforms.
+/* Yield a properly aligned upper bound on the size of a struct of
+   type TYPE with a flexible array member named MEMBER that is
+   followed by N bytes of other data.  The result is suitable as an
+   argument to malloc.  For example:
+
+     struct s { int n; char d[FLEXIBLE_ARRAY_MEMBER]; };
+     struct s *p = malloc (FLEXSIZEOF (struct s, d, n * sizeof (char)));
+
+   FLEXSIZEOF (TYPE, MEMBER, N) is not simply (sizeof (TYPE) + N),
+   since FLEXIBLE_ARRAY_MEMBER may be 1 on pre-C11 platforms.  Nor is
+   it simply (offsetof (TYPE, MEMBER) + N), as that might yield a size
+   that causes malloc to yield a pointer that is not properly aligned
+   for TYPE; for example, if sizeof (int) == alignof (int) == 4,
+   malloc (offsetof (struct s, d) + 3 * sizeof (char)) is equivalent
+   to malloc (7) and might yield a pointer that is not a multiple of 4
+   (which means the pointer is not properly aligned for struct s),
+   whereas malloc (FLEXSIZEOF (struct s, d, 3 * sizeof (char))) is
+   equivalent to malloc (8) and must yield a pointer that is a
+   multiple of 4.
+
    Yield a value less than N if and only if arithmetic overflow occurs.  */
 
 #define FLEXSIZEOF(type, member, n) \
diff --git a/lib/verify.h b/lib/verify.h
index 6930645a350..f8e4eff026d 100644
--- a/lib/verify.h
+++ b/lib/verify.h
@@ -21,29 +21,37 @@
 #define _GL_VERIFY_H
 
 
-/* Define _GL_HAVE__STATIC_ASSERT to 1 if _Static_assert works as per C11.
-   This is supported by GCC 4.6.0 and later, in C mode, and its use
-   here generates easier-to-read diagnostics when verify (R) fails.
-
-   Define _GL_HAVE_STATIC_ASSERT to 1 if static_assert works as per C++11.
-   This is supported by GCC 6.1.0 and later, in C++ mode.
-
-   Use this only with GCC.  If we were willing to slow 'configure'
-   down we could also use it with other compilers, but since this
-   affects only the quality of diagnostics, why bother?  */
-#if (4 < __GNUC__ + (6 <= __GNUC_MINOR__) \
-     && (201112L <= __STDC_VERSION__  || !defined __STRICT_ANSI__) \
-     && !defined __cplusplus)
-# define _GL_HAVE__STATIC_ASSERT 1
-#endif
-#if (6 <= __GNUC__) && defined __cplusplus
-# define _GL_HAVE_STATIC_ASSERT 1
+/* Define _GL_HAVE__STATIC_ASSERT to 1 if _Static_assert (R, DIAGNOSTIC)
+   works as per C11.  This is supported by GCC 4.6.0 and later, in C
+   mode.
+
+   Define _GL_HAVE__STATIC_ASSERT1 to 1 if _Static_assert (R) works as
+   per C2X, and define _GL_HAVE_STATIC_ASSERT1 if static_assert (R)
+   works as per C++17.  This is supported by GCC 9.1 and later.
+
+   Support compilers claiming conformance to the relevant standard,
+   and also support GCC when not pedantic.  If we were willing to slow
+   'configure' down we could also use it with other compilers, but
+   since this affects only the quality of diagnostics, why bother?  */
+#ifndef __cplusplus
+# if (201112L <= __STDC_VERSION__ \
+      || (!defined __STRICT_ANSI__ && 4 < __GNUC__ + (6 <= __GNUC_MINOR__)))
+#  define _GL_HAVE__STATIC_ASSERT 1
+# endif
+# if (202000L <= __STDC_VERSION__ \
+      || (!defined __STRICT_ANSI__ && 9 <= __GNUC__))
+#  define _GL_HAVE__STATIC_ASSERT1 1
+# endif
+#else
+# if 201703L <= __cplusplus || 9 <= __GNUC__
+#  define _GL_HAVE_STATIC_ASSERT1 1
+# endif
 #endif
 
 /* FreeBSD 9.1 <sys/cdefs.h>, included by <stddef.h> and lots of other
    system headers, defines a conflicting _Static_assert that is no
    better than ours; override it.  */
-#ifndef _GL_HAVE_STATIC_ASSERT
+#ifndef _GL_HAVE__STATIC_ASSERT
 # include <stddef.h>
 # undef _Static_assert
 #endif
@@ -141,9 +149,9 @@
      which do not support _Static_assert, also do not warn about the
      last declaration mentioned above.
 
-   * GCC warns if -Wnested-externs is enabled and verify() is used
+   * GCC warns if -Wnested-externs is enabled and 'verify' is used
      within a function body; but inside a function, you can always
-     arrange to use verify_expr() instead.
+     arrange to use verify_expr instead.
 
    * In C++, any struct definition inside sizeof is invalid.
      Use a template type to work around the problem.  */
@@ -167,11 +175,9 @@
 #define _GL_GENSYM(prefix) _GL_CONCAT (prefix, _GL_COUNTER)
 
 /* Verify requirement R at compile-time, as an integer constant expression
-   that returns 1.  If R is false, fail at compile-time, preferably
-   with a diagnostic that includes the string-literal DIAGNOSTIC.  */
+   that returns 1.  If R is false, fail at compile-time.  */
 
-#define _GL_VERIFY_TRUE(R, DIAGNOSTIC) \
-   (!!sizeof (_GL_VERIFY_TYPE (R, DIAGNOSTIC)))
+#define _GL_VERIFY_TRUE(R) (!!sizeof (_GL_VERIFY_TYPE (R)))
 
 #ifdef __cplusplus
 # if !GNULIB_defined_struct__gl_verify_type
@@ -181,40 +187,43 @@ template <int w>
   };
 #  define GNULIB_defined_struct__gl_verify_type 1
 # endif
-# define _GL_VERIFY_TYPE(R, DIAGNOSTIC) \
-    _gl_verify_type<(R) ? 1 : -1>
-#elif defined _GL_HAVE__STATIC_ASSERT
-# define _GL_VERIFY_TYPE(R, DIAGNOSTIC) \
+# define _GL_VERIFY_TYPE(R) _gl_verify_type<(R) ? 1 : -1>
+#elif defined _GL_HAVE__STATIC_ASSERT1
+# define _GL_VERIFY_TYPE(R) \
     struct {                                   \
-      _Static_assert (R, DIAGNOSTIC);          \
+      _Static_assert (R); \
       int _gl_dummy;                          \
     }
 #else
-# define _GL_VERIFY_TYPE(R, DIAGNOSTIC) \
+# define _GL_VERIFY_TYPE(R)                                             \
     struct { unsigned int _gl_verify_error_if_negative: (R) ? 1 : -1; }
 #endif
 
 /* Verify requirement R at compile-time, as a declaration without a
-   trailing ';'.  If R is false, fail at compile-time, preferably
-   with a diagnostic that includes the string-literal DIAGNOSTIC.
+   trailing ';'.  If R is false, fail at compile-time.
+
+   This macro requires three or more arguments but uses at most the first
+   two, so that the _Static_assert macro optionally defined below supports
+   both the C11 two-argument syntax and the C2X one-argument syntax.
 
    Unfortunately, unlike C11, this implementation must appear as an
    ordinary declaration, and cannot appear inside struct { ... }.  */
 
-#ifdef _GL_HAVE__STATIC_ASSERT
-# define _GL_VERIFY _Static_assert
+#if defined _GL_HAVE__STATIC_ASSERT
+# define _GL_VERIFY(R, DIAGNOSTIC, ...) _Static_assert (R, DIAGNOSTIC)
 #else
-# define _GL_VERIFY(R, DIAGNOSTIC)                                     \
+# define _GL_VERIFY(R, DIAGNOSTIC, ...)                                \
     extern int (*_GL_GENSYM (_gl_verify_function) (void))              \
-      [_GL_VERIFY_TRUE (R, DIAGNOSTIC)]
+      [_GL_VERIFY_TRUE (R)]
 #endif
 
 /* _GL_STATIC_ASSERT_H is defined if this code is copied into assert.h.  */
 #ifdef _GL_STATIC_ASSERT_H
-# if !defined _GL_HAVE__STATIC_ASSERT && !defined _Static_assert
-#  define _Static_assert(R, DIAGNOSTIC) _GL_VERIFY (R, DIAGNOSTIC)
+# if !defined _GL_HAVE__STATIC_ASSERT1 && !defined _Static_assert
+#  define _Static_assert(...) \
+     _GL_VERIFY (__VA_ARGS__, "static assertion failed", -)
 # endif
-# if !defined _GL_HAVE_STATIC_ASSERT && !defined static_assert
+# if !defined _GL_HAVE_STATIC_ASSERT1 && !defined static_assert
 #  define static_assert _Static_assert /* C11 requires this #define.  */
 # endif
 #endif
@@ -226,31 +235,24 @@ template <int w>
    assert (R), there is no run-time overhead.
 
    There are two macros, since no single macro can be used in all
-   contexts in C.  verify_true (R) is for scalar contexts, including
+   contexts in C.  verify_expr (R, E) is for scalar contexts, including
    integer constant expression contexts.  verify (R) is for declaration
    contexts, e.g., the top level.  */
 
-/* Verify requirement R at compile-time, as an integer constant expression.
-   Return 1.  This is equivalent to verify_expr (R, 1).
-
-   verify_true is obsolescent; please use verify_expr instead.  */
-
-#define verify_true(R) _GL_VERIFY_TRUE (R, "verify_true (" #R ")")
-
 /* Verify requirement R at compile-time.  Return the value of the
    expression E.  */
 
-#define verify_expr(R, E) \
-   (_GL_VERIFY_TRUE (R, "verify_expr (" #R ", " #E ")") ? (E) : (E))
+#define verify_expr(R, E) (_GL_VERIFY_TRUE (R) ? (E) : (E))
 
 /* Verify requirement R at compile-time, as a declaration without a
-   trailing ';'.  */
+   trailing ';'.  verify (R) acts like static_assert (R) except that
+   it is portable to C11/C++14 and earlier, and its name is shorter
+   and may be more convenient.  */
 
-#ifdef __GNUC__
-# define verify(R) _GL_VERIFY (R, "verify (" #R ")")
+#ifdef _GL_HAVE__STATIC_ASSERT1
+# define verify(R) _Static_assert (R)
 #else
-/* PGI barfs if R is long.  Play it safe.  */
-# define verify(R) _GL_VERIFY (R, "verify (...)")
+# define verify(R) _GL_VERIFY (R, "verify (...)", -)
 #endif
 
 #ifndef __has_builtin