Update from Gnulib

This incorporates:
2020-08-23 intprops: be consistent about +X vs X+0
2020-08-23 intprops: fix INT_MULTIPLY_WRAPV bit-field bug
2020-08-23 verify: Make assume work on bit field expressions
2020-08-23 libc-config: Improve comments
2020-08-22 verify: Do use __builtin_assume on clang
2020-08-22 sig2str: Add more signals
2020-08-21 sigdescr_np: New module
* lib/cdefs.h, lib/intprops.h, lib/sig2str.c, lib/string.in.h:
* lib/verify.h, m4/string_h.m4: Copy from Gnulib.
* lib/gnulib.mk.in: Regenerate.

6 files changed, 80 insertions, 16 deletions

diff --git a/lib/cdefs.h b/lib/cdefs.h
index b1870fd0a93..ff7c628a264 100644
--- a/lib/cdefs.h
+++ b/lib/cdefs.h
@@ -148,7 +148,11 @@
 # define __warnattr(msg) __attribute__((__warning__ (msg)))
 # define __errordecl(name, msg) \
   extern void name (void) __attribute__((__error__ (msg)))
-#elif __glibc_clang_has_attribute (__diagnose_if__) && 0 /* fails on Fedora 31 with Clang 9.  */
+#elif __glibc_clang_has_attribute (__diagnose_if__) && 0
+/* These definitions are not enabled, because they produce bogus warnings
+   in the glibc Fortify functions.  These functions are written in a style
+   that works with GCC.  In order to work with clang, these functions would
+   need to be modified.  */
 # define __warndecl(name, msg) \
   extern void name (void) __attribute__((__diagnose_if__ (1, msg, "warning")))
 # define __warnattr(msg) __attribute__((__diagnose_if__ (1, msg, "warning")))
diff --git a/lib/gnulib.mk.in b/lib/gnulib.mk.in
index 78b4542d80a..86eb14383c1 100644
--- a/lib/gnulib.mk.in
+++ b/lib/gnulib.mk.in
@@ -426,6 +426,7 @@ GNULIB_SETENV = @GNULIB_SETENV@
 GNULIB_SETHOSTNAME = @GNULIB_SETHOSTNAME@
 GNULIB_SIGABBREV_NP = @GNULIB_SIGABBREV_NP@
 GNULIB_SIGACTION = @GNULIB_SIGACTION@
+GNULIB_SIGDESCR_NP = @GNULIB_SIGDESCR_NP@
 GNULIB_SIGNAL_H_SIGPIPE = @GNULIB_SIGNAL_H_SIGPIPE@
 GNULIB_SIGPROCMASK = @GNULIB_SIGPROCMASK@
 GNULIB_SLEEP = @GNULIB_SLEEP@
@@ -647,6 +648,7 @@ HAVE_SETHOSTNAME = @HAVE_SETHOSTNAME@
 HAVE_SETSTATE = @HAVE_SETSTATE@
 HAVE_SIGABBREV_NP = @HAVE_SIGABBREV_NP@
 HAVE_SIGACTION = @HAVE_SIGACTION@
+HAVE_SIGDESCR_NP = @HAVE_SIGDESCR_NP@
 HAVE_SIGHANDLER_T = @HAVE_SIGHANDLER_T@
 HAVE_SIGINFO_T = @HAVE_SIGINFO_T@
 HAVE_SIGNED_SIG_ATOMIC_T = @HAVE_SIGNED_SIG_ATOMIC_T@
@@ -2846,6 +2848,7 @@ string.h: string.in.h $(top_builddir)/config.status $(CXXDEFS_H) $(ARG_NONNULL_H
 	      -e 's/@''GNULIB_STRERROR''@/$(GNULIB_STRERROR)/g' \
 	      -e 's/@''GNULIB_STRERROR_R''@/$(GNULIB_STRERROR_R)/g' \
 	      -e 's/@''GNULIB_SIGABBREV_NP''@/$(GNULIB_SIGABBREV_NP)/g' \
+	      -e 's/@''GNULIB_SIGDESCR_NP''@/$(GNULIB_SIGDESCR_NP)/g' \
 	      -e 's/@''GNULIB_STRSIGNAL''@/$(GNULIB_STRSIGNAL)/g' \
 	      -e 's/@''GNULIB_STRVERSCMP''@/$(GNULIB_STRVERSCMP)/g' \
 	      < $(srcdir)/string.in.h | \
@@ -2869,6 +2872,7 @@ string.h: string.in.h $(top_builddir)/config.status $(CXXDEFS_H) $(ARG_NONNULL_H
 	      -e 's|@''HAVE_DECL_STRTOK_R''@|$(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_SIGDESCR_NP''@|$(HAVE_SIGDESCR_NP)|g' \
 	      -e 's|@''HAVE_DECL_STRSIGNAL''@|$(HAVE_DECL_STRSIGNAL)|g' \
 	      -e 's|@''HAVE_STRVERSCMP''@|$(HAVE_STRVERSCMP)|g' \
 	      -e 's|@''REPLACE_MEMCHR''@|$(REPLACE_MEMCHR)|g' \
diff --git a/lib/intprops.h b/lib/intprops.h
index f2f70b3e733..b27f2eea056 100644
--- a/lib/intprops.h
+++ b/lib/intprops.h
@@ -48,7 +48,7 @@
 /* Minimum and maximum values for integer types and expressions.  */
 
 /* The width in bits of the integer type or expression T.
-   Do not evaluate T.
+   Do not evaluate T.  T must not be a bit-field expression.
    Padding bits are not supported; this is checked at compile-time below.  */
 #define TYPE_WIDTH(t) (sizeof (t) * CHAR_BIT)
 
@@ -70,7 +70,7 @@
    ? _GL_SIGNED_INT_MAXIMUM (e)                                         \
    : _GL_INT_NEGATE_CONVERT (e, 1))
 #define _GL_SIGNED_INT_MAXIMUM(e)                                       \
-  (((_GL_INT_CONVERT (e, 1) << (TYPE_WIDTH ((e) + 0) - 2)) - 1) * 2 + 1)
+  (((_GL_INT_CONVERT (e, 1) << (TYPE_WIDTH (+ (e)) - 2)) - 1) * 2 + 1)
 
 /* Work around OpenVMS incompatibility with C99.  */
 #if !defined LLONG_MAX && defined __INT64_MAX
@@ -95,8 +95,9 @@
 #endif
 
 /* Return 1 if the integer type or expression T might be signed.  Return 0
-   if it is definitely unsigned.  This macro does not evaluate its argument,
-   and expands to an integer constant expression.  */
+   if it is definitely unsigned.  T must not be a bit-field expression.
+   This macro does not evaluate its argument, and expands to an
+   integer constant expression.  */
 #if _GL_HAVE___TYPEOF__
 # define _GL_SIGNED_TYPE_OR_EXPR(t) TYPE_SIGNED (__typeof__ (t))
 #else
@@ -109,6 +110,8 @@
 #define INT_BITS_STRLEN_BOUND(b) (((b) * 146 + 484) / 485)
 
 /* Bound on length of the string representing an integer type or expression T.
+   T must not be a bit-field expression.
+
    Subtract 1 for the sign bit if T is signed, and then add 1 more for
    a minus sign if needed.
 
@@ -120,7 +123,7 @@
    + _GL_SIGNED_TYPE_OR_EXPR (t))
 
 /* Bound on buffer size needed to represent an integer type or expression T,
-   including the terminating null.  */
+   including the terminating null.  T must not be a bit-field expression.  */
 #define INT_BUFSIZE_BOUND(t) (INT_STRLEN_BOUND (t) + 1)
 
 
@@ -566,7 +569,7 @@
       ? (EXPR_SIGNED (_GL_INT_CONVERT (tmax, b)) \
          ? (a) < (tmax) / (b) \
          : ((INT_NEGATE_OVERFLOW (b) \
-             ? _GL_INT_CONVERT (b, tmax) >> (TYPE_WIDTH (b) - 1) \
+             ? _GL_INT_CONVERT (b, tmax) >> (TYPE_WIDTH (+ (b)) - 1) \
              : (tmax) / -(b)) \
             <= -1 - (a))) \
       : INT_NEGATE_OVERFLOW (_GL_INT_CONVERT (b, tmin)) && (b) == -1 \
diff --git a/lib/sig2str.c b/lib/sig2str.c
index 905daea2f20..cf7c3bb5c38 100644
--- a/lib/sig2str.c
+++ b/lib/sig2str.c
@@ -189,6 +189,11 @@ static struct numname { int num; char const name[8]; } numname_table[] =
     NUMNAME (STKFLT),
 #endif
 
+    /* AIX 7.  */
+#ifdef SIGCPUFAIL
+    NUMNAME (CPUFAIL),
+#endif
+
     /* AIX 5L.  */
 #ifdef SIGDANGER
     NUMNAME (DANGER),
@@ -229,7 +234,12 @@ static struct numname { int num; char const name[8]; } numname_table[] =
     NUMNAME (WINDOW),   /* Older name for SIGWINCH.  */
 #endif
 
-    /* BeOS */
+    /* OpenBSD.  */
+#ifdef SIGTHR
+    NUMNAME (THR),
+#endif
+
+    /* BeOS, Haiku */
 #ifdef SIGKILLTHR
     NUMNAME (KILLTHR),
 #endif
@@ -239,6 +249,11 @@ static struct numname { int num; char const name[8]; } numname_table[] =
     NUMNAME (DIL),
 #endif
 
+    /* native Windows */
+#ifdef SIGBREAK
+    NUMNAME (BREAK),
+#endif
+
     /* Korn shell and Bash, of uncertain vintage.  */
     { 0, "EXIT" }
   };
diff --git a/lib/string.in.h b/lib/string.in.h
index 5134e11289d..776133c5eba 100644
--- a/lib/string.in.h
+++ b/lib/string.in.h
@@ -1060,6 +1060,21 @@ _GL_WARN_ON_USE (sigabbrev_np, "sigabbrev_np is unportable - "
 # endif
 #endif
 
+/* Return an English description string for the signal number SIG.  */
+#if @GNULIB_SIGDESCR_NP@
+# if ! @HAVE_SIGDESCR_NP@
+_GL_FUNCDECL_SYS (sigdescr_np, const char *, (int sig));
+# endif
+_GL_CXXALIAS_SYS (sigdescr_np, const char *, (int sig));
+_GL_CXXALIASWARN (sigdescr_np);
+#elif defined GNULIB_POSIXCHECK
+# undef sigdescr_np
+# if HAVE_RAW_DECL_SIGDESCR_NP
+_GL_WARN_ON_USE (sigdescr_np, "sigdescr_np is unportable - "
+                 "use gnulib module sigdescr_np for portability");
+# endif
+#endif
+
 #if @GNULIB_STRSIGNAL@
 # if @REPLACE_STRSIGNAL@
 #  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
diff --git a/lib/verify.h b/lib/verify.h
index d485a0283a9..6d7b961db71 100644
--- a/lib/verify.h
+++ b/lib/verify.h
@@ -246,6 +246,13 @@ template <int w>
 
 /* @assert.h omit start@  */
 
+#if defined __has_builtin
+/* <https://clang.llvm.org/docs/LanguageExtensions.html#builtin-functions> */
+# define _GL_HAS_BUILTIN_ASSUME __has_builtin (__builtin_assume)
+#else
+# define _GL_HAS_BUILTIN_ASSUME 0
+#endif
+
 #if 3 < __GNUC__ + (3 < __GNUC_MINOR__ + (4 <= __GNUC_PATCHLEVEL__))
 # define _GL_HAS_BUILTIN_TRAP 1
 #elif defined __has_builtin
@@ -305,14 +312,30 @@ template <int w>
 
    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.
-
-   Avoid Clang’s __builtin_assume, as clang 9.0.1 -Wassume can
-   generate a bogus diagnostic "the argument to '__builtin_assume' has
-   side effects that will be discarded" even when the argument has no
-   side effects.  */
-
-#if _GL_HAS_BUILTIN_UNREACHABLE
+   features such as function calls not inlined by the compiler.  */
+
+/* Use __builtin_assume in preference to __builtin_unreachable, because
+   in clang versions 8.0.x and older, the definition based on
+   __builtin_assume has an effect on optimizations, whereas the definition
+   based on __builtin_unreachable does not.  (GCC so far has only
+   __builtin_unreachable.)  */
+#if _GL_HAS_BUILTIN_ASSUME
+/* Use a temporary variable, to avoid a clang warning
+   "the argument to '__builtin_assume' has side effects that will be discarded"
+   if R contains invocations of functions not marked as 'const'.
+   The type of the temporary variable can't be __typeof__ (R), because that
+   does not work on bit field expressions.  Use '_Bool' or 'bool' as type
+   instead.  */
+# if defined __cplusplus
+#  define assume(R) \
+     ((void) ({ bool _gl_verify_temp = (R); \
+                __builtin_assume (_gl_verify_temp); }))
+# else
+#  define assume(R) \
+     ((void) ({ _Bool _gl_verify_temp = (R); \
+                __builtin_assume (_gl_verify_temp); }))
+# endif
+#elif _GL_HAS_BUILTIN_UNREACHABLE
 # define assume(R) ((R) ? (void) 0 : __builtin_unreachable ())
 #elif 1200 <= _MSC_VER
 # define assume(R) __assume (R)