From ad8b801c7e9c2da4b6f056ec87bf5e5ed522b418 Mon Sep 17 00:00:00 2001 From: Marko Lindqvist Date: Mon, 5 Oct 2026 21:02:24 +0300 Subject: [PATCH 41/41] Fix configure check for 'C++20 capture this' on clang Both meson and autotools based builds affected. See RM #2335 Signed-off-by: Marko Lindqvist --- configure.ac | 2 +- m4/debug.m4 | 3 ++- meson.build | 18 +++++++++++++----- 3 files changed, 16 insertions(+), 7 deletions(-) diff --git a/configure.ac b/configure.ac index 4e62eb4b47..d6a8ab746e 100644 --- a/configure.ac +++ b/configure.ac @@ -673,7 +673,7 @@ dnl Detect flags to be used in configure tests that should fail on warnings WERROR_C_TEST_FLAGS="" WERROR_CXX_TEST_FLAGS="" FC_C_FLAGS([-Werror -Wall], [], [WERROR_C_TEST_FLAGS]) -FC_CXX_FLAGS([-Werror -Wall], [], [WERROR_CXX_TEST_FLAGS]) +FC_CXX_FLAGS([-Werror -Wall -Wno-c++20-extensions], [], [WERROR_CXX_TEST_FLAGS]) FC_C99_VARIADIC_MACROS FC_C99_VARIABLE_ARRAYS diff --git a/m4/debug.m4 b/m4/debug.m4 index dcf680e39e..0206dbfbbf 100644 --- a/m4/debug.m4 +++ b/m4/debug.m4 @@ -76,7 +76,8 @@ dnl -Wall set earlier, and not the other way around. FC_C_FLAGS([-Wno-tautological-compare], [], [EXTRA_DEBUG_CFLAGS]) if test "x$cxx_works" = "xyes" ; then - FC_CXX_FLAGS([-Wno-tautological-compare -Wno-deprecated-declarations], + FC_CXX_FLAGS([-Wno-tautological-compare -Wno-deprecated-declarations \ + -Wno-c++20-extensions], [], [EXTRA_DEBUG_CXXFLAGS]) fi diff --git a/meson.build b/meson.build index 0ef4ac17f3..9ab5082262 100644 --- a/meson.build +++ b/meson.build @@ -51,7 +51,8 @@ c_cpp_args = [ cpp_args = [ '-Wno-deprecated-declarations', - '-fPIC' + '-fPIC', + '-Wno-c++20-extensions' ] foreach arg : c_args @@ -1065,14 +1066,21 @@ if svgflags pub_conf_data.set('FREECIV_SVG_FLAGS', 1) endif -if cxx_build and cxx_compiler.compiles(''' +if cxx_build + if cxx_compiler.has_argument('-Wno-c++20-extensions') + accept_cxx_20 = ['-Wno-c++20-extensions'] + else + accept_cxx_20 = [] + endif + if cxx_compiler.compiles(''' class me { void top(); }; void me::top() { (void) [=, this]() { this->top(); }; }; ''', - name: 'C++20 capture this', - args: ['-Werror', '-Wall']) - pub_conf_data.set('FREECIV_HAVE_CXX20_CAPTURE_THIS', 1) + name: 'C++20 capture this', + args: ['-Werror', '-Wall', accept_cxx_20]) + pub_conf_data.set('FREECIV_HAVE_CXX20_CAPTURE_THIS', 1) + endif endif if not meson.is_cross_build() -- 2.53.0