public inbox for gcc-cvs@sourceware.org help / color / mirror / Atom feed
From: Nathan Sidwell <nathan@gcc.gnu.org> To: gcc-cvs@gcc.gnu.org Subject: [gcc/devel/c++-modules] configure: Also check C++11 (flags) for ${build} compiler not only for ${host} Date: Fri, 28 Aug 2020 15:58:25 +0000 (GMT) [thread overview] Message-ID: <20200828155825.8C8F8386180E@sourceware.org> (raw) https://gcc.gnu.org/g:7ffcf5d61174dda1f39a623e15f7e5d6b98bbafc commit 7ffcf5d61174dda1f39a623e15f7e5d6b98bbafc Author: Tobias Burnus <tobias@codesourcery.com> Date: Thu Aug 20 21:59:00 2020 +0200 configure: Also check C++11 (flags) for ${build} compiler not only for ${host} config/ChangeLog: PR bootstrap/96612 * ax_cxx_compile_stdcxx.m4: Add fourth argument to check also the CXX_FOR_BUILD compiler. ChangeLog: PR bootstrap/96612 * configure.ac: Run AX_CXX_COMPILE_STDCXX also for ${build} compiler, if not the same as ${host}. * configure: Regenerate. Diff: --- config/ax_cxx_compile_stdcxx.m4 | 39 +- configure | 1007 +++++++++++++++++++++++++++++++++++++++ configure.ac | 4 + 3 files changed, 1039 insertions(+), 11 deletions(-) diff --git a/config/ax_cxx_compile_stdcxx.m4 b/config/ax_cxx_compile_stdcxx.m4 index 9413da624d2..8c55ebd2044 100644 --- a/config/ax_cxx_compile_stdcxx.m4 +++ b/config/ax_cxx_compile_stdcxx.m4 @@ -25,6 +25,10 @@ # regardless, after defining HAVE_CXX${VERSION} if and only if a # supporting mode is found. # +# If the fourth argument is an optional CXX/CXXFLAG/CPPFLAG suffix, e.g. +# "_FOR_BUILD" or "_FOR_TARGET". +# +# # LICENSE # # Copyright (c) 2008 Benjamin Kosnik <bkoz@redhat.com> @@ -62,14 +66,20 @@ AC_DEFUN([AX_CXX_COMPILE_STDCXX], [dnl [m4_fatal([invalid third argument `$3' to AX_CXX_COMPILE_STDCXX])]) AC_LANG_PUSH([C++])dnl ac_success=no - + m4_ifnblank([$4], [dnl + ax_cv_cxx_compile_cxx$1_orig_cxx="$CXX" + ax_cv_cxx_compile_cxx$1_orig_cxxflags="$CXXFLAGS" + ax_cv_cxx_compile_cxx$1_orig_cppflags="$CPPFLAGS" + CXX="$CXX$4" + CXXFLAGS="$CXXFLAGS$4" + CPPFLAGS="$CPPFLAGS$4"]) m4_if([$2], [], [dnl AC_CACHE_CHECK(whether $CXX supports C++$1 features by default, - ax_cv_cxx_compile_cxx$1, + ax_cv_cxx_compile_cxx$1$4, [AC_COMPILE_IFELSE([AC_LANG_SOURCE([_AX_CXX_COMPILE_STDCXX_testbody_$1])], - [ax_cv_cxx_compile_cxx$1=yes], - [ax_cv_cxx_compile_cxx$1=no])]) - if test x$ax_cv_cxx_compile_cxx$1 = xyes; then + [ax_cv_cxx_compile_cxx$1$4=yes], + [ax_cv_cxx_compile_cxx$1$4=no])]) + if test x$ax_cv_cxx_compile_cxx$1$4 = xyes; then ac_success=yes fi]) @@ -77,7 +87,7 @@ AC_DEFUN([AX_CXX_COMPILE_STDCXX], [dnl if test x$ac_success = xno; then for alternative in ${ax_cxx_compile_alternatives}; do switch="-std=gnu++${alternative}" - cachevar=AS_TR_SH([ax_cv_cxx_compile_cxx$1_$switch]) + cachevar=AS_TR_SH([ax_cv_cxx_compile_cxx$1$4_$switch]) AC_CACHE_CHECK(whether $CXX supports C++$1 features with $switch, $cachevar, [ac_save_CXX="$CXX" @@ -104,7 +114,7 @@ AC_DEFUN([AX_CXX_COMPILE_STDCXX], [dnl dnl Cray's crayCC needs "-h std=c++11" for alternative in ${ax_cxx_compile_alternatives}; do for switch in -std=c++${alternative} +std=c++${alternative} "-h std=c++${alternative}"; do - cachevar=AS_TR_SH([ax_cv_cxx_compile_cxx$1_$switch]) + cachevar=AS_TR_SH([ax_cv_cxx_compile_cxx$1$4_$switch]) AC_CACHE_CHECK(whether $CXX supports C++$1 features with $switch, $cachevar, [ac_save_CXX="$CXX" @@ -127,6 +137,13 @@ AC_DEFUN([AX_CXX_COMPILE_STDCXX], [dnl fi done fi]) + m4_ifnblank([$4], [dnl + CXX$4="$CXX" + CXXFLAGS$4="$CXXFLAGS" + CPPFLAGS$4="$CPPFLAGS" + CXX="$ax_cv_cxx_compile_cxx$1_orig_cxx" + CXXFLAGS="$ax_cv_cxx_compile_cxx$1_orig_cxxflags" + CPPFLAGS="$ax_cv_cxx_compile_cxx$1_orig_cppflags"]) AC_LANG_POP([C++]) if test x$ax_cxx_compile_cxx$1_required = xtrue; then if test x$ac_success = xno; then @@ -134,14 +151,14 @@ AC_DEFUN([AX_CXX_COMPILE_STDCXX], [dnl fi fi if test x$ac_success = xno; then - HAVE_CXX$1=0 + HAVE_CXX$1$4=0 AC_MSG_NOTICE([No compiler with C++$1 support was found]) else - HAVE_CXX$1=1 - AC_DEFINE(HAVE_CXX$1,1, + HAVE_CXX$1$4=1 + AC_DEFINE(HAVE_CXX$1$4,1, [define if the compiler supports basic C++$1 syntax]) fi - AC_SUBST(HAVE_CXX$1) + AC_SUBST(HAVE_CXX$1$4) ]) diff --git a/configure b/configure index a0c5aca9e8d..057b88966e4 100755 --- a/configure +++ b/configure @@ -694,6 +694,7 @@ extra_mpc_gmp_configure_flags extra_mpfr_configure_flags gmpinc gmplibs +HAVE_CXX11_FOR_BUILD HAVE_CXX11 do_compare GNATMAKE @@ -6498,6 +6499,7 @@ $as_echo "$ac_res" >&6; } fi done fi + ac_ext=c ac_cpp='$CPP $CPPFLAGS' ac_compile='$CC -c $CFLAGS $CPPFLAGS conftest.$ac_ext >&5' @@ -6521,6 +6523,1011 @@ $as_echo "#define HAVE_CXX11 1" >>confdefs.h fi + + if test "${build}" != "${host}"; then + ax_cxx_compile_alternatives="11 0x" ax_cxx_compile_cxx11_required=true + ac_ext=cpp +ac_cpp='$CXXCPP $CPPFLAGS' +ac_compile='$CXX -c $CXXFLAGS $CPPFLAGS conftest.$ac_ext >&5' +ac_link='$CXX -o conftest$ac_exeext $CXXFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5' +ac_compiler_gnu=$ac_cv_cxx_compiler_gnu + ac_success=no + ax_cv_cxx_compile_cxx11_orig_cxx="$CXX" + ax_cv_cxx_compile_cxx11_orig_cxxflags="$CXXFLAGS" + ax_cv_cxx_compile_cxx11_orig_cppflags="$CPPFLAGS" + CXX="$CXX_FOR_BUILD" + CXXFLAGS="$CXXFLAGS_FOR_BUILD" + CPPFLAGS="$CPPFLAGS_FOR_BUILD" + { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether $CXX supports C++11 features by default" >&5 +$as_echo_n "checking whether $CXX supports C++11 features by default... " >&6; } +if ${ax_cv_cxx_compile_cxx11_FOR_BUILD+:} false; then : + $as_echo_n "(cached) " >&6 +else + cat confdefs.h - <<_ACEOF >conftest.$ac_ext +/* end confdefs.h. */ + + +// If the compiler admits that it is not ready for C++11, why torture it? +// Hopefully, this will speed up the test. + +#ifndef __cplusplus + +#error "This is not a C++ compiler" + +#elif __cplusplus < 201103L + +#error "This is not a C++11 compiler" + +#else + +namespace cxx11 +{ + + namespace test_static_assert + { + + template <typename T> + struct check + { + static_assert(sizeof(int) <= sizeof(T), "not big enough"); + }; + + } + + namespace test_final_override + { + + struct Base + { + virtual ~Base() {} + virtual void f() {} + }; + + struct Derived : public Base + { + virtual ~Derived() override {} + virtual void f() override {} + }; + + } + + namespace test_double_right_angle_brackets + { + + template < typename T > + struct check {}; + + typedef check<void> single_type; + typedef check<check<void>> double_type; + typedef check<check<check<void>>> triple_type; + typedef check<check<check<check<void>>>> quadruple_type; + + } + + namespace test_decltype + { + + int + f() + { + int a = 1; + decltype(a) b = 2; + return a + b; + } + + } + + namespace test_type_deduction + { + + template < typename T1, typename T2 > + struct is_same + { + static const bool value = false; + }; + + template < typename T > + struct is_same<T, T> + { + static const bool value = true; + }; + + template < typename T1, typename T2 > + auto + add(T1 a1, T2 a2) -> decltype(a1 + a2) + { + return a1 + a2; + } + + int + test(const int c, volatile int v) + { + static_assert(is_same<int, decltype(0)>::value == true, ""); + static_assert(is_same<int, decltype(c)>::value == false, ""); + static_assert(is_same<int, decltype(v)>::value == false, ""); + auto ac = c; + auto av = v; + auto sumi = ac + av + 'x'; + auto sumf = ac + av + 1.0; + static_assert(is_same<int, decltype(ac)>::value == true, ""); + static_assert(is_same<int, decltype(av)>::value == true, ""); + static_assert(is_same<int, decltype(sumi)>::value == true, ""); + static_assert(is_same<int, decltype(sumf)>::value == false, ""); + static_assert(is_same<int, decltype(add(c, v))>::value == true, ""); + return (sumf > 0.0) ? sumi : add(c, v); + } + + } + + namespace test_noexcept + { + + int f() { return 0; } + int g() noexcept { return 0; } + + static_assert(noexcept(f()) == false, ""); + static_assert(noexcept(g()) == true, ""); + + } + + namespace test_constexpr + { + + template < typename CharT > + unsigned long constexpr + strlen_c_r(const CharT *const s, const unsigned long acc) noexcept + { + return *s ? strlen_c_r(s + 1, acc + 1) : acc; + } + + template < typename CharT > + unsigned long constexpr + strlen_c(const CharT *const s) noexcept + { + return strlen_c_r(s, 0UL); + } + + static_assert(strlen_c("") == 0UL, ""); + static_assert(strlen_c("1") == 1UL, ""); + static_assert(strlen_c("example") == 7UL, ""); + static_assert(strlen_c("another\0example") == 7UL, ""); + + } + + namespace test_rvalue_references + { + + template < int N > + struct answer + { + static constexpr int value = N; + }; + + answer<1> f(int&) { return answer<1>(); } + answer<2> f(const int&) { return answer<2>(); } + answer<3> f(int&&) { return answer<3>(); } + + void + test() + { + int i = 0; + const int c = 0; + static_assert(decltype(f(i))::value == 1, ""); + static_assert(decltype(f(c))::value == 2, ""); + static_assert(decltype(f(0))::value == 3, ""); + } + + } + + namespace test_uniform_initialization + { + + struct test + { + static const int zero {}; + static const int one {1}; + }; + + static_assert(test::zero == 0, ""); + static_assert(test::one == 1, ""); + + } + + namespace test_lambdas + { + + void + test1() + { + auto lambda1 = [](){}; + auto lambda2 = lambda1; + lambda1(); + lambda2(); + } + + int + test2() + { + auto a = [](int i, int j){ return i + j; }(1, 2); + auto b = []() -> int { return '0'; }(); + auto c = [=](){ return a + b; }(); + auto d = [&](){ return c; }(); + auto e = [a, &b](int x) mutable { + const auto identity = [](int y){ return y; }; + for (auto i = 0; i < a; ++i) + a += b--; + return x + identity(a + b); + }(0); + return a + b + c + d + e; + } + + int + test3() + { + const auto nullary = [](){ return 0; }; + const auto unary = [](int x){ return x; }; + using nullary_t = decltype(nullary); + using unary_t = decltype(unary); + const auto higher1st = [](nullary_t f){ return f(); }; + const auto higher2nd = [unary](nullary_t f1){ + return [unary, f1](unary_t f2){ return f2(unary(f1())); }; + }; + return higher1st(nullary) + higher2nd(nullary)(unary); + } + + } + + namespace test_variadic_templates + { + + template <int...> + struct sum; + + template <int N0, int... N1toN> + struct sum<N0, N1toN...> + { + static constexpr auto value = N0 + sum<N1toN...>::value; + }; + + template <> + struct sum<> + { + static constexpr auto value = 0; + }; + + static_assert(sum<>::value == 0, ""); + static_assert(sum<1>::value == 1, ""); + static_assert(sum<23>::value == 23, ""); + static_assert(sum<1, 2>::value == 3, ""); + static_assert(sum<5, 5, 11>::value == 21, ""); + static_assert(sum<2, 3, 5, 7, 11, 13>::value == 41, ""); + + } + + // http://stackoverflow.com/questions/13728184/template-aliases-and-sfinae + // Clang 3.1 fails with headers of libstd++ 4.8.3 when using std::function + // because of this. + namespace test_template_alias_sfinae + { + + struct foo {}; + + template<typename T> + using member = typename T::member_type; + + template<typename T> + void func(...) {} + + template<typename T> + void func(member<T>*) {} + + void test(); + + void test() { func<foo>(0); } + + } + +} // namespace cxx11 + +#endif // __cplusplus >= 201103L + + + +_ACEOF +if ac_fn_cxx_try_compile "$LINENO"; then : + ax_cv_cxx_compile_cxx11_FOR_BUILD=yes +else + ax_cv_cxx_compile_cxx11_FOR_BUILD=no +fi +rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext +fi +{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ax_cv_cxx_compile_cxx11_FOR_BUILD" >&5 +$as_echo "$ax_cv_cxx_compile_cxx11_FOR_BUILD" >&6; } + if test x$ax_cv_cxx_compile_cxx11_FOR_BUILD = xyes; then + ac_success=yes + fi + + if test x$ac_success = xno; then + for alternative in ${ax_cxx_compile_alternatives}; do + switch="-std=gnu++${alternative}" + cachevar=`$as_echo "ax_cv_cxx_compile_cxx11_FOR_BUILD_$switch" | $as_tr_sh` + { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether $CXX supports C++11 features with $switch" >&5 +$as_echo_n "checking whether $CXX supports C++11 features with $switch... " >&6; } +if eval \${$cachevar+:} false; then : + $as_echo_n "(cached) " >&6 +else + ac_save_CXX="$CXX" + CXX="$CXX $switch" + cat confdefs.h - <<_ACEOF >conftest.$ac_ext +/* end confdefs.h. */ + + +// If the compiler admits that it is not ready for C++11, why torture it? +// Hopefully, this will speed up the test. + +#ifndef __cplusplus + +#error "This is not a C++ compiler" + +#elif __cplusplus < 201103L + +#error "This is not a C++11 compiler" + +#else + +namespace cxx11 +{ + + namespace test_static_assert + { + + template <typename T> + struct check + { + static_assert(sizeof(int) <= sizeof(T), "not big enough"); + }; + + } + + namespace test_final_override + { + + struct Base + { + virtual ~Base() {} + virtual void f() {} + }; + + struct Derived : public Base + { + virtual ~Derived() override {} + virtual void f() override {} + }; + + } + + namespace test_double_right_angle_brackets + { + + template < typename T > + struct check {}; + + typedef check<void> single_type; + typedef check<check<void>> double_type; + typedef check<check<check<void>>> triple_type; + typedef check<check<check<check<void>>>> quadruple_type; + + } + + namespace test_decltype + { + + int + f() + { + int a = 1; + decltype(a) b = 2; + return a + b; + } + + } + + namespace test_type_deduction + { + + template < typename T1, typename T2 > + struct is_same + { + static const bool value = false; + }; + + template < typename T > + struct is_same<T, T> + { + static const bool value = true; + }; + + template < typename T1, typename T2 > + auto + add(T1 a1, T2 a2) -> decltype(a1 + a2) + { + return a1 + a2; + } + + int + test(const int c, volatile int v) + { + static_assert(is_same<int, decltype(0)>::value == true, ""); + static_assert(is_same<int, decltype(c)>::value == false, ""); + static_assert(is_same<int, decltype(v)>::value == false, ""); + auto ac = c; + auto av = v; + auto sumi = ac + av + 'x'; + auto sumf = ac + av + 1.0; + static_assert(is_same<int, decltype(ac)>::value == true, ""); + static_assert(is_same<int, decltype(av)>::value == true, ""); + static_assert(is_same<int, decltype(sumi)>::value == true, ""); + static_assert(is_same<int, decltype(sumf)>::value == false, ""); + static_assert(is_same<int, decltype(add(c, v))>::value == true, ""); + return (sumf > 0.0) ? sumi : add(c, v); + } + + } + + namespace test_noexcept + { + + int f() { return 0; } + int g() noexcept { return 0; } + + static_assert(noexcept(f()) == false, ""); + static_assert(noexcept(g()) == true, ""); + + } + + namespace test_constexpr + { + + template < typename CharT > + unsigned long constexpr + strlen_c_r(const CharT *const s, const unsigned long acc) noexcept + { + return *s ? strlen_c_r(s + 1, acc + 1) : acc; + } + + template < typename CharT > + unsigned long constexpr + strlen_c(const CharT *const s) noexcept + { + return strlen_c_r(s, 0UL); + } + + static_assert(strlen_c("") == 0UL, ""); + static_assert(strlen_c("1") == 1UL, ""); + static_assert(strlen_c("example") == 7UL, ""); + static_assert(strlen_c("another\0example") == 7UL, ""); + + } + + namespace test_rvalue_references + { + + template < int N > + struct answer + { + static constexpr int value = N; + }; + + answer<1> f(int&) { return answer<1>(); } + answer<2> f(const int&) { return answer<2>(); } + answer<3> f(int&&) { return answer<3>(); } + + void + test() + { + int i = 0; + const int c = 0; + static_assert(decltype(f(i))::value == 1, ""); + static_assert(decltype(f(c))::value == 2, ""); + static_assert(decltype(f(0))::value == 3, ""); + } + + } + + namespace test_uniform_initialization + { + + struct test + { + static const int zero {}; + static const int one {1}; + }; + + static_assert(test::zero == 0, ""); + static_assert(test::one == 1, ""); + + } + + namespace test_lambdas + { + + void + test1() + { + auto lambda1 = [](){}; + auto lambda2 = lambda1; + lambda1(); + lambda2(); + } + + int + test2() + { + auto a = [](int i, int j){ return i + j; }(1, 2); + auto b = []() -> int { return '0'; }(); + auto c = [=](){ return a + b; }(); + auto d = [&](){ return c; }(); + auto e = [a, &b](int x) mutable { + const auto identity = [](int y){ return y; }; + for (auto i = 0; i < a; ++i) + a += b--; + return x + identity(a + b); + }(0); + return a + b + c + d + e; + } + + int + test3() + { + const auto nullary = [](){ return 0; }; + const auto unary = [](int x){ return x; }; + using nullary_t = decltype(nullary); + using unary_t = decltype(unary); + const auto higher1st = [](nullary_t f){ return f(); }; + const auto higher2nd = [unary](nullary_t f1){ + return [unary, f1](unary_t f2){ return f2(unary(f1())); }; + }; + return higher1st(nullary) + higher2nd(nullary)(unary); + } + + } + + namespace test_variadic_templates + { + + template <int...> + struct sum; + + template <int N0, int... N1toN> + struct sum<N0, N1toN...> + { + static constexpr auto value = N0 + sum<N1toN...>::value; + }; + + template <> + struct sum<> + { + static constexpr auto value = 0; + }; + + static_assert(sum<>::value == 0, ""); + static_assert(sum<1>::value == 1, ""); + static_assert(sum<23>::value == 23, ""); + static_assert(sum<1, 2>::value == 3, ""); + static_assert(sum<5, 5, 11>::value == 21, ""); + static_assert(sum<2, 3, 5, 7, 11, 13>::value == 41, ""); + + } + + // http://stackoverflow.com/questions/13728184/template-aliases-and-sfinae + // Clang 3.1 fails with headers of libstd++ 4.8.3 when using std::function + // because of this. + namespace test_template_alias_sfinae + { + + struct foo {}; + + template<typename T> + using member = typename T::member_type; + + template<typename T> + void func(...) {} + + template<typename T> + void func(member<T>*) {} + + void test(); + + void test() { func<foo>(0); } + + } + +} // namespace cxx11 + +#endif // __cplusplus >= 201103L + + + +_ACEOF +if ac_fn_cxx_try_compile "$LINENO"; then : + eval $cachevar=yes +else + eval $cachevar=no +fi +rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext + CXX="$ac_save_CXX" +fi +eval ac_res=\$$cachevar + { $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_res" >&5 +$as_echo "$ac_res" >&6; } + if eval test x\$$cachevar = xyes; then + CXX="$CXX $switch" + if test -n "$CXXCPP" ; then + CXXCPP="$CXXCPP $switch" + fi + ac_success=yes + break + fi + done + fi + + if test x$ac_success = xno; then + for alternative in ${ax_cxx_compile_alternatives}; do + for switch in -std=c++${alternative} +std=c++${alternative} "-h std=c++${alternative}"; do + cachevar=`$as_echo "ax_cv_cxx_compile_cxx11_FOR_BUILD_$switch" | $as_tr_sh` + { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether $CXX supports C++11 features with $switch" >&5 +$as_echo_n "checking whether $CXX supports C++11 features with $switch... " >&6; } +if eval \${$cachevar+:} false; then : + $as_echo_n "(cached) " >&6 +else + ac_save_CXX="$CXX" + CXX="$CXX $switch" + cat confdefs.h - <<_ACEOF >conftest.$ac_ext +/* end confdefs.h. */ + + +// If the compiler admits that it is not ready for C++11, why torture it? +// Hopefully, this will speed up the test. + +#ifndef __cplusplus + +#error "This is not a C++ compiler" + +#elif __cplusplus < 201103L + +#error "This is not a C++11 compiler" + +#else + +namespace cxx11 +{ + + namespace test_static_assert + { + + template <typename T> + struct check + { + static_assert(sizeof(int) <= sizeof(T), "not big enough"); + }; + + } + + namespace test_final_override + { + + struct Base + { + virtual ~Base() {} + virtual void f() {} + }; + + struct Derived : public Base + { + virtual ~Derived() override {} + virtual void f() override {} + }; + + } + + namespace test_double_right_angle_brackets + { + + template < typename T > + struct check {}; + + typedef check<void> single_type; + typedef check<check<void>> double_type; + typedef check<check<check<void>>> triple_type; + typedef check<check<check<check<void>>>> quadruple_type; + + } + + namespace test_decltype + { + + int + f() + { + int a = 1; + decltype(a) b = 2; + return a + b; + } + + } + + namespace test_type_deduction + { + + template < typename T1, typename T2 > + struct is_same + { + static const bool value = false; + }; + + template < typename T > + struct is_same<T, T> + { + static const bool value = true; + }; + + template < typename T1, typename T2 > + auto + add(T1 a1, T2 a2) -> decltype(a1 + a2) + { + return a1 + a2; + } + + int + test(const int c, volatile int v) + { + static_assert(is_same<int, decltype(0)>::value == true, ""); + static_assert(is_same<int, decltype(c)>::value == false, ""); + static_assert(is_same<int, decltype(v)>::value == false, ""); + auto ac = c; + auto av = v; + auto sumi = ac + av + 'x'; + auto sumf = ac + av + 1.0; + static_assert(is_same<int, decltype(ac)>::value == true, ""); + static_assert(is_same<int, decltype(av)>::value == true, ""); + static_assert(is_same<int, decltype(sumi)>::value == true, ""); + static_assert(is_same<int, decltype(sumf)>::value == false, ""); + static_assert(is_same<int, decltype(add(c, v))>::value == true, ""); + return (sumf > 0.0) ? sumi : add(c, v); + } + + } + + namespace test_noexcept + { + + int f() { return 0; } + int g() noexcept { return 0; } + + static_assert(noexcept(f()) == false, ""); + static_assert(noexcept(g()) == true, ""); + + } + + namespace test_constexpr + { + + template < typename CharT > + unsigned long constexpr + strlen_c_r(const CharT *const s, const unsigned long acc) noexcept + { + return *s ? strlen_c_r(s + 1, acc + 1) : acc; + } + + template < typename CharT > + unsigned long constexpr + strlen_c(const CharT *const s) noexcept + { + return strlen_c_r(s, 0UL); + } + + static_assert(strlen_c("") == 0UL, ""); + static_assert(strlen_c("1") == 1UL, ""); + static_assert(strlen_c("example") == 7UL, ""); + static_assert(strlen_c("another\0example") == 7UL, ""); + + } + + namespace test_rvalue_references + { + + template < int N > + struct answer + { + static constexpr int value = N; + }; + + answer<1> f(int&) { return answer<1>(); } + answer<2> f(const int&) { return answer<2>(); } + answer<3> f(int&&) { return answer<3>(); } + + void + test() + { + int i = 0; + const int c = 0; + static_assert(decltype(f(i))::value == 1, ""); + static_assert(decltype(f(c))::value == 2, ""); + static_assert(decltype(f(0))::value == 3, ""); + } + + } + + namespace test_uniform_initialization + { + + struct test + { + static const int zero {}; + static const int one {1}; + }; + + static_assert(test::zero == 0, ""); + static_assert(test::one == 1, ""); + + } + + namespace test_lambdas + { + + void + test1() + { + auto lambda1 = [](){}; + auto lambda2 = lambda1; + lambda1(); + lambda2(); + } + + int + test2() + { + auto a = [](int i, int j){ return i + j; }(1, 2); + auto b = []() -> int { return '0'; }(); + auto c = [=](){ return a + b; }(); + auto d = [&](){ return c; }(); + auto e = [a, &b](int x) mutable { + const auto identity = [](int y){ return y; }; + for (auto i = 0; i < a; ++i) + a += b--; + return x + identity(a + b); + }(0); + return a + b + c + d + e; + } + + int + test3() + { + const auto nullary = [](){ return 0; }; + const auto unary = [](int x){ return x; }; + using nullary_t = decltype(nullary); + using unary_t = decltype(unary); + const auto higher1st = [](nullary_t f){ return f(); }; + const auto higher2nd = [unary](nullary_t f1){ + return [unary, f1](unary_t f2){ return f2(unary(f1())); }; + }; + return higher1st(nullary) + higher2nd(nullary)(unary); + } + + } + + namespace test_variadic_templates + { + + template <int...> + struct sum; + + template <int N0, int... N1toN> + struct sum<N0, N1toN...> + { + static constexpr auto value = N0 + sum<N1toN...>::value; + }; + + template <> + struct sum<> + { + static constexpr auto value = 0; + }; + + static_assert(sum<>::value == 0, ""); + static_assert(sum<1>::value == 1, ""); + static_assert(sum<23>::value == 23, ""); + static_assert(sum<1, 2>::value == 3, ""); + static_assert(sum<5, 5, 11>::value == 21, ""); + static_assert(sum<2, 3, 5, 7, 11, 13>::value == 41, ""); + + } + + // http://stackoverflow.com/questions/13728184/template-aliases-and-sfinae + // Clang 3.1 fails with headers of libstd++ 4.8.3 when using std::function + // because of this. + namespace test_template_alias_sfinae + { + + struct foo {}; + + template<typename T> + using member = typename T::member_type; + + template<typename T> + void func(...) {} + + template<typename T> + void func(member<T>*) {} + + void test(); + + void test() { func<foo>(0); } + + } + +} // namespace cxx11 + +#endif // __cplusplus >= 201103L + + + +_ACEOF +if ac_fn_cxx_try_compile "$LINENO"; then : + eval $cachevar=yes +else + eval $cachevar=no +fi +rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext + CXX="$ac_save_CXX" +fi +eval ac_res=\$$cachevar + { $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_res" >&5 +$as_echo "$ac_res" >&6; } + if eval test x\$$cachevar = xyes; then + CXX="$CXX $switch" + if test -n "$CXXCPP" ; then + CXXCPP="$CXXCPP $switch" + fi + ac_success=yes + break + fi + done + if test x$ac_success = xyes; then + break + fi + done + fi + CXX_FOR_BUILD="$CXX" + CXXFLAGS_FOR_BUILD="$CXXFLAGS" + CPPFLAGS_FOR_BUILD="$CPPFLAGS" + CXX="$ax_cv_cxx_compile_cxx11_orig_cxx" + CXXFLAGS="$ax_cv_cxx_compile_cxx11_orig_cxxflags" + CPPFLAGS="$ax_cv_cxx_compile_cxx11_orig_cppflags" + ac_ext=c +ac_cpp='$CPP $CPPFLAGS' +ac_compile='$CC -c $CFLAGS $CPPFLAGS conftest.$ac_ext >&5' +ac_link='$CC -o conftest$ac_exeext $CFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5' +ac_compiler_gnu=$ac_cv_c_compiler_gnu + + if test x$ax_cxx_compile_cxx11_required = xtrue; then + if test x$ac_success = xno; then + as_fn_error $? "*** A compiler with support for C++11 language features is required." "$LINENO" 5 + fi + fi + if test x$ac_success = xno; then + HAVE_CXX11_FOR_BUILD=0 + { $as_echo "$as_me:${as_lineno-$LINENO}: No compiler with C++11 support was found" >&5 +$as_echo "$as_me: No compiler with C++11 support was found" >&6;} + else + HAVE_CXX11_FOR_BUILD=1 + +$as_echo "#define HAVE_CXX11_FOR_BUILD 1" >>confdefs.h + + fi + + + fi fi # Used for setting $lt_cv_objdir diff --git a/configure.ac b/configure.ac index 1a53ed418e4..392389fb2fb 100644 --- a/configure.ac +++ b/configure.ac @@ -1470,6 +1470,10 @@ if test "$enable_bootstrap:$GXX" = "yes:yes"; then CXX="$CXX -std=c++11" elif test "$have_compiler" = yes; then AX_CXX_COMPILE_STDCXX(11) + + if test "${build}" != "${host}"; then + AX_CXX_COMPILE_STDCXX(11, [], [], [_FOR_BUILD]) + fi fi # Used for setting $lt_cv_objdir
reply other threads:[~2020-08-28 15:58 UTC|newest] Thread overview: [no followups] expand[flat|nested] mbox.gz Atom feed
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=20200828155825.8C8F8386180E@sourceware.org \ --to=nathan@gcc.gnu.org \ --cc=gcc-cvs@gcc.gnu.org \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: linkBe sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions for how to clone and mirror all data and code used for this inbox; as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).