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-rw-r--r--macros/texinfo/texinfo/tp/Texinfo/XS/gnulib/lib/verify.h73
1 files changed, 48 insertions, 25 deletions
diff --git a/macros/texinfo/texinfo/tp/Texinfo/XS/gnulib/lib/verify.h b/macros/texinfo/texinfo/tp/Texinfo/XS/gnulib/lib/verify.h
index afdc1ad81f..65514c34b9 100644
--- a/macros/texinfo/texinfo/tp/Texinfo/XS/gnulib/lib/verify.h
+++ b/macros/texinfo/texinfo/tp/Texinfo/XS/gnulib/lib/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, 2009-2021 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
@@ -22,12 +22,10 @@
/* 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.
+ works as per C11. This is supported by GCC 4.6.0+ and by clang 4+.
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.
+ per C2X. This is supported by GCC 9.1+.
Support compilers claiming conformance to the relevant standard,
and also support GCC when not pedantic. If we were willing to slow
@@ -35,17 +33,14 @@
since this affects only the quality of diagnostics, why bother? */
#ifndef __cplusplus
# if (201112L <= __STDC_VERSION__ \
- || (!defined __STRICT_ANSI__ && 4 < __GNUC__ + (6 <= __GNUC_MINOR__)))
+ || (!defined __STRICT_ANSI__ \
+ && (4 < __GNUC__ + (6 <= __GNUC_MINOR__) || 4 <= __clang_major__)))
# 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
@@ -212,7 +207,9 @@ template <int w>
Unfortunately, unlike C11, this implementation must appear as an
ordinary declaration, and cannot appear inside struct { ... }. */
-#if defined _GL_HAVE__STATIC_ASSERT
+#if 200410 <= __cpp_static_assert
+# define _GL_VERIFY(R, DIAGNOSTIC, ...) static_assert (R, DIAGNOSTIC)
+#elif defined _GL_HAVE__STATIC_ASSERT
# define _GL_VERIFY(R, DIAGNOSTIC, ...) _Static_assert (R, DIAGNOSTIC)
#else
# define _GL_VERIFY(R, DIAGNOSTIC, ...) \
@@ -226,13 +223,29 @@ template <int w>
# define _Static_assert(...) \
_GL_VERIFY (__VA_ARGS__, "static assertion failed", -)
# endif
-# if !defined _GL_HAVE_STATIC_ASSERT1 && !defined static_assert
+# if __cpp_static_assert < 201411 && !defined static_assert
# define static_assert _Static_assert /* C11 requires this #define. */
# endif
#endif
/* @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 +273,34 @@ 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.
+
+ Avoid Clang's __builtin_assume, as it breaks GNU Emacs master
+ as of 2020-08-23T21:09:49Z!eggert@cs.ucla.edu; see
+ <https://bugs.gnu.org/43152#71>. It's not known whether this breakage
+ is a Clang bug or an Emacs bug; play it safe for now. */
-#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. */