From bedf196eeebe249f75f71a51a55edca5da78e027 Mon Sep 17 00:00:00 2001
From: Paul Eggert <eggert@cs.ucla.edu>
Date: Wed, 13 Jan 2021 15:46:33 -0800
Subject: [PATCH] verify: simplify static_assert configuration

* lib/verify.h (_GL_HAVE__STATIC_ASSERT, _GL_HAVE__STATIC_ASSERT1):
Do not define for C++.  This should be good enough nowadays,
since recent-enough C++ compilers have static_assert.
(_GL_HAVE_STATIC_ASSERT_CXX11, _GL_HAVE_STATIC_ASSERT_CXX17):
Remove.  All uses replaced by simply checking __cpp_static_assert.
---
 ChangeLog    |  9 +++++++++
 lib/verify.h | 35 ++++-------------------------------
 2 files changed, 13 insertions(+), 31 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 2123974c8..8991d6a35 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,12 @@
+2021-01-13  Paul Eggert  <eggert@cs.ucla.edu>
+
+	verify: simplify static_assert configuration
+	* lib/verify.h (_GL_HAVE__STATIC_ASSERT, _GL_HAVE__STATIC_ASSERT1):
+	Do not define for C++.  This should be good enough nowadays,
+	since recent-enough C++ compilers have static_assert.
+	(_GL_HAVE_STATIC_ASSERT_CXX11, _GL_HAVE_STATIC_ASSERT_CXX17):
+	Remove.  All uses replaced by simply checking __cpp_static_assert.
+
 2021-01-13  Simon Josefsson  <simon@josefsson.org>
 
 	lib-msvc-compat: Update libtool usage recommendation.
diff --git a/lib/verify.h b/lib/verify.h
index a9e75890f..65514c34b 100644
--- a/lib/verify.h
+++ b/lib/verify.h
@@ -22,20 +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, and by clang (also 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.  This is supported by GCC 9.1 and later, and by clang in
-   C++1z mode.
-
-   Define _GL_HAVE_STATIC_ASSERT_CXX11 if static_assert (R, DIAGNOSTIC)
-   works as per C++11.  This is supported by GCC 6.1 and later, and by
-   clang in C++11 mode.
-
-   Define _GL_HAVE_STATIC_ASSERT_CXX17 if static_assert (R) works as per
-   C++17.  This is supported by GCC 9.1 and later, and by clang in
-   C++1z mode.
+   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
@@ -51,23 +41,6 @@
       || (!defined __STRICT_ANSI__ && 9 <= __GNUC__))
 #  define _GL_HAVE__STATIC_ASSERT1 1
 # endif
-#else
-# if 4 <= __clang_major__
-#  define _GL_HAVE__STATIC_ASSERT 1
-# endif
-# if 4 <= __clang_major__ && 201411 <= __cpp_static_assert
-#  define _GL_HAVE__STATIC_ASSERT1 1
-# endif
-# if 201103L <= __cplusplus \
-     || 6 <= __GNUC__ \
-     || (4 <= __clang_major__ && 200410 <= __cpp_static_assert)
-#  define _GL_HAVE_STATIC_ASSERT_CXX11 1
-# endif
-# if 201703L <= __cplusplus \
-     || 9 <= __GNUC__ \
-     || (4 <= __clang_major__ && 201411 <= __cpp_static_assert)
-#  define _GL_HAVE_STATIC_ASSERT_CXX17 1
-# endif
 #endif
 
 /* FreeBSD 9.1 <sys/cdefs.h>, included by <stddef.h> and lots of other
@@ -234,7 +207,7 @@ 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_CXX11
+#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)
@@ -250,7 +223,7 @@ template <int w>
 #  define _Static_assert(...) \
      _GL_VERIFY (__VA_ARGS__, "static assertion failed", -)
 # endif
-# if !defined _GL_HAVE_STATIC_ASSERT_CXX17 && !defined static_assert
+# if __cpp_static_assert < 201411 && !defined static_assert
 #  define static_assert _Static_assert /* C11 requires this #define.  */
 # endif
 #endif
-- 
2.27.0