src: Use gnu++17 as the default C++ standard

Previously the compiler's default C++ standard was used unlike C where
bsd.sys.mk explicitly sets a default language version.  Setting an
explicit default version will give a more uniform experience across
different compilers and compiler versions.

gnu++17 was chosen to match the default C standard.  It is well
supported by a wide range of clang (5+) and GCC (9+) versions.

gnu++17 is also the default C++ standard in recent versions of clang
(16+) and GCC (11+).  As a result, many of the explicit CXXSTD
settings in Makefiles had the effect of lowering the C++ standard
instead of raising it as was originally intended and are removed.

Note that the remaining explicit CXXSTD settings for atf and liblutok
explicitly lower the standard to C++11 due to use of the deprecated
auto_ptr<> template which is removed in later versions.

Reviewed by:	imp, asomers, dim, emaste
Differential Revision:	https://reviews.freebsd.org/D49223

This commit is contained in:

John Baldwin

2025-04-11 09:53:50 -04:00

parent 75a24e7f9a

commit 6527682ab7

13 changed files with 2 additions and 15 deletions

									
										share/mk/googletest.test.inc.mk
									
		-2
	
												View File
												
				@@ -9,6 +9,4 @@ GTESTS_CXXFLAGS+= -frtti

				# libgmock's, etc, headers.

				CXXFLAGS+=	-I${DESTDIR}${INCLUDEDIR}/private

				CXXSTD?=	c++14

				NO_WTHREAD_SAFETY=