diff --git a/Makefile.in b/Makefile.in index b373cc8c..0d0ccba2 100644 --- a/Makefile.in +++ b/Makefile.in @@ -2446,7 +2446,7 @@ GMOCK_LIBS = @GMOCK_LIBS@ GREP = @GREP@ GTEST_CFLAGS = @GTEST_CFLAGS@ GTEST_LIBS = @GTEST_LIBS@ -HAVE_CXX11 = @HAVE_CXX11@ +HAVE_CXX17 = @HAVE_CXX17@ INSTALL = @INSTALL@ INSTALL_DATA = @INSTALL_DATA@ INSTALL_PROGRAM = @INSTALL_PROGRAM@ diff --git a/configure b/configure index 22f0a026..d131f5a9 100755 --- a/configure +++ b/configure @@ -676,7 +676,7 @@ ANDROID_HOST_TRUE LINUX_HOST_FALSE LINUX_HOST_TRUE WARN_CXXFLAGS -HAVE_CXX11 +HAVE_CXX17 HAVE_MEMFD_CREATE_FALSE HAVE_MEMFD_CREATE_TRUE HAVE_GETCONTEXT_FALSE @@ -7740,336 +7740,31 @@ fi - ax_cxx_compile_cxx11_required=true + ax_cxx_compile_alternatives="17 1z" ax_cxx_compile_cxx17_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 - { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking whether $CXX supports C++11 features by default" >&5 -printf %s "checking whether $CXX supports C++11 features by default... " >&6; } -if test ${ax_cv_cxx_compile_cxx11+y} -then : - printf %s "(cached) " >&6 -else $as_nop - cat confdefs.h - <<_ACEOF >conftest.$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 - struct check - { - static_assert(sizeof(int) <= sizeof(T), "not big enough"); - }; - - } - - namespace test_final_override - { - - struct Base - { - virtual void f() {} - }; - - struct Derived : public Base - { - virtual void f() override {} - }; - - } - - namespace test_double_right_angle_brackets - { - - template < typename T > - struct check {}; - - typedef check single_type; - typedef check> double_type; - typedef check>> triple_type; - typedef check>>> 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 - { - 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::value == true, ""); - static_assert(is_same::value == false, ""); - static_assert(is_same::value == false, ""); - auto ac = c; - auto av = v; - auto sumi = ac + av + 'x'; - auto sumf = ac + av + 1.0; - static_assert(is_same::value == true, ""); - static_assert(is_same::value == true, ""); - static_assert(is_same::value == true, ""); - static_assert(is_same::value == false, ""); - static_assert(is_same::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 - struct sum; - - template - struct sum - { - static constexpr auto value = N0 + sum::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 - using member = typename T::member_type; - - template - void func(...) {} - - template - void func(member*) {} - - void test(); - - void test() { func(0); } - - } - -} // namespace cxx11 - -#endif // __cplusplus >= 201103L - - - -_ACEOF -if ac_fn_cxx_try_compile "$LINENO" -then : - ax_cv_cxx_compile_cxx11=yes -else $as_nop - ax_cv_cxx_compile_cxx11=no -fi -rm -f core conftest.err conftest.$ac_objext conftest.beam conftest.$ac_ext -fi -{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ax_cv_cxx_compile_cxx11" >&5 -printf "%s\n" "$ax_cv_cxx_compile_cxx11" >&6; } - if test x$ax_cv_cxx_compile_cxx11 = xyes; then - ac_success=yes - fi if test x$ac_success = xno; then - for switch in -std=c++11 -std=c++0x +std=c++11 "-h std=c++11"; do - cachevar=`printf "%s\n" "ax_cv_cxx_compile_cxx11_$switch" | $as_tr_sh` - { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking whether $CXX supports C++11 features with $switch" >&5 -printf %s "checking whether $CXX supports C++11 features with $switch... " >&6; } + for alternative in ${ax_cxx_compile_alternatives}; do + for switch in -std=c++${alternative} +std=c++${alternative} "-h std=c++${alternative}"; do + cachevar=`printf "%s\n" "ax_cv_cxx_compile_cxx17_$switch" | $as_tr_sh` + { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking whether $CXX supports C++17 features with $switch" >&5 +printf %s "checking whether $CXX supports C++17 features with $switch... " >&6; } if eval test \${$cachevar+y} then : printf %s "(cached) " >&6 else $as_nop - ac_save_CXXFLAGS="$CXXFLAGS" - CXXFLAGS="$CXXFLAGS $switch" - cat confdefs.h - <<_ACEOF >conftest.$ac_ext + ac_save_CXX="$CXX" + CXX="$CXX $switch" + cat confdefs.h - <<_ACEOF >conftest.$ac_ext /* end confdefs.h. */ @@ -8080,7 +7775,11 @@ else $as_nop #error "This is not a C++ compiler" -#elif __cplusplus < 201103L +// MSVC always sets __cplusplus to 199711L in older versions; newer versions +// only set it correctly if /Zc:__cplusplus is specified as well as a +// /std:c++NN switch: +// https://devblogs.microsoft.com/cppblog/msvc-now-correctly-reports-__cplusplus/ +#elif __cplusplus < 201103L && !defined _MSC_VER #error "This is not a C++11 compiler" @@ -8105,11 +7804,13 @@ namespace cxx11 struct Base { + virtual ~Base() {} virtual void f() {} }; struct Derived : public Base { + virtual ~Derived() override {} virtual void f() override {} }; @@ -8357,6 +8058,504 @@ namespace cxx11 + +// If the compiler admits that it is not ready for C++14, why torture it? +// Hopefully, this will speed up the test. + +#ifndef __cplusplus + +#error "This is not a C++ compiler" + +#elif __cplusplus < 201402L && !defined _MSC_VER + +#error "This is not a C++14 compiler" + +#else + +namespace cxx14 +{ + + namespace test_polymorphic_lambdas + { + + int + test() + { + const auto lambda = [](auto&&... args){ + const auto istiny = [](auto x){ + return (sizeof(x) == 1UL) ? 1 : 0; + }; + const int aretiny[] = { istiny(args)... }; + return aretiny[0]; + }; + return lambda(1, 1L, 1.0f, '1'); + } + + } + + namespace test_binary_literals + { + + constexpr auto ivii = 0b0000000000101010; + static_assert(ivii == 42, "wrong value"); + + } + + namespace test_generalized_constexpr + { + + template < typename CharT > + constexpr unsigned long + strlen_c(const CharT *const s) noexcept + { + auto length = 0UL; + for (auto p = s; *p; ++p) + ++length; + return length; + } + + static_assert(strlen_c("") == 0UL, ""); + static_assert(strlen_c("x") == 1UL, ""); + static_assert(strlen_c("test") == 4UL, ""); + static_assert(strlen_c("another\0test") == 7UL, ""); + + } + + namespace test_lambda_init_capture + { + + int + test() + { + auto x = 0; + const auto lambda1 = [a = x](int b){ return a + b; }; + const auto lambda2 = [a = lambda1(x)](){ return a; }; + return lambda2(); + } + + } + + namespace test_digit_separators + { + + constexpr auto ten_million = 100'000'000; + static_assert(ten_million == 100000000, ""); + + } + + namespace test_return_type_deduction + { + + auto f(int& x) { return x; } + decltype(auto) g(int& x) { return x; } + + template < typename T1, typename T2 > + struct is_same + { + static constexpr auto value = false; + }; + + template < typename T > + struct is_same + { + static constexpr auto value = true; + }; + + int + test() + { + auto x = 0; + static_assert(is_same::value, ""); + static_assert(is_same::value, ""); + return x; + } + + } + +} // namespace cxx14 + +#endif // __cplusplus >= 201402L + + + + +// If the compiler admits that it is not ready for C++17, why torture it? +// Hopefully, this will speed up the test. + +#ifndef __cplusplus + +#error "This is not a C++ compiler" + +#elif __cplusplus < 201703L && !defined _MSC_VER + +#error "This is not a C++17 compiler" + +#else + +#include +#include +#include + +namespace cxx17 +{ + + namespace test_constexpr_lambdas + { + + constexpr int foo = [](){return 42;}(); + + } + + namespace test::nested_namespace::definitions + { + + } + + namespace test_fold_expression + { + + template + int multiply(Args... args) + { + return (args * ... * 1); + } + + template + bool all(Args... args) + { + return (args && ...); + } + + } + + namespace test_extended_static_assert + { + + static_assert (true); + + } + + namespace test_auto_brace_init_list + { + + auto foo = {5}; + auto bar {5}; + + static_assert(std::is_same, decltype(foo)>::value); + static_assert(std::is_same::value); + } + + namespace test_typename_in_template_template_parameter + { + + template typename X> struct D; + + } + + namespace test_fallthrough_nodiscard_maybe_unused_attributes + { + + int f1() + { + return 42; + } + + [[nodiscard]] int f2() + { + [[maybe_unused]] auto unused = f1(); + + switch (f1()) + { + case 17: + f1(); + [[fallthrough]]; + case 42: + f1(); + } + return f1(); + } + + } + + namespace test_extended_aggregate_initialization + { + + struct base1 + { + int b1, b2 = 42; + }; + + struct base2 + { + base2() { + b3 = 42; + } + int b3; + }; + + struct derived : base1, base2 + { + int d; + }; + + derived d1 {{1, 2}, {}, 4}; // full initialization + derived d2 {{}, {}, 4}; // value-initialized bases + + } + + namespace test_general_range_based_for_loop + { + + struct iter + { + int i; + + int& operator* () + { + return i; + } + + const int& operator* () const + { + return i; + } + + iter& operator++() + { + ++i; + return *this; + } + }; + + struct sentinel + { + int i; + }; + + bool operator== (const iter& i, const sentinel& s) + { + return i.i == s.i; + } + + bool operator!= (const iter& i, const sentinel& s) + { + return !(i == s); + } + + struct range + { + iter begin() const + { + return {0}; + } + + sentinel end() const + { + return {5}; + } + }; + + void f() + { + range r {}; + + for (auto i : r) + { + [[maybe_unused]] auto v = i; + } + } + + } + + namespace test_lambda_capture_asterisk_this_by_value + { + + struct t + { + int i; + int foo() + { + return [*this]() + { + return i; + }(); + } + }; + + } + + namespace test_enum_class_construction + { + + enum class byte : unsigned char + {}; + + byte foo {42}; + + } + + namespace test_constexpr_if + { + + template + int f () + { + if constexpr(cond) + { + return 13; + } + else + { + return 42; + } + } + + } + + namespace test_selection_statement_with_initializer + { + + int f() + { + return 13; + } + + int f2() + { + if (auto i = f(); i > 0) + { + return 3; + } + + switch (auto i = f(); i + 4) + { + case 17: + return 2; + + default: + return 1; + } + } + + } + + namespace test_template_argument_deduction_for_class_templates + { + + template + struct pair + { + pair (T1 p1, T2 p2) + : m1 {p1}, + m2 {p2} + {} + + T1 m1; + T2 m2; + }; + + void f() + { + [[maybe_unused]] auto p = pair{13, 42u}; + } + + } + + namespace test_non_type_auto_template_parameters + { + + template + struct B + {}; + + B<5> b1; + B<'a'> b2; + + } + + namespace test_structured_bindings + { + + int arr[2] = { 1, 2 }; + std::pair pr = { 1, 2 }; + + auto f1() -> int(&)[2] + { + return arr; + } + + auto f2() -> std::pair& + { + return pr; + } + + struct S + { + int x1 : 2; + volatile double y1; + }; + + S f3() + { + return {}; + } + + auto [ x1, y1 ] = f1(); + auto& [ xr1, yr1 ] = f1(); + auto [ x2, y2 ] = f2(); + auto& [ xr2, yr2 ] = f2(); + const auto [ x3, y3 ] = f3(); + + } + + namespace test_exception_spec_type_system + { + + struct Good {}; + struct Bad {}; + + void g1() noexcept; + void g2(); + + template + Bad + f(T*, T*); + + template + Good + f(T1*, T2*); + + static_assert (std::is_same_v); + + } + + namespace test_inline_variables + { + + template void f(T) + {} + + template inline T g(T) + { + return T{}; + } + + template<> inline void f<>(int) + {} + + template<> int g<>(int) + { + return 5; + } + + } + +} // namespace cxx17 + +#endif // __cplusplus < 201703L && !defined _MSC_VER + + + _ACEOF if ac_fn_cxx_try_compile "$LINENO" then : @@ -8365,14 +8564,21 @@ else $as_nop eval $cachevar=no fi rm -f core conftest.err conftest.$ac_objext conftest.beam conftest.$ac_ext - CXXFLAGS="$ac_save_CXXFLAGS" + CXX="$ac_save_CXX" fi eval ac_res=\$$cachevar { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_res" >&5 printf "%s\n" "$ac_res" >&6; } - if eval test x\$$cachevar = xyes; then - CXXFLAGS="$CXXFLAGS $switch" - ac_success=yes + if eval test x\$$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 @@ -8383,26 +8589,24 @@ 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$ax_cxx_compile_cxx11_required = xtrue; then + if test x$ax_cxx_compile_cxx17_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 + as_fn_error $? "*** A compiler with support for C++17 language features is required." "$LINENO" 5 fi + fi + if test x$ac_success = xno; then + HAVE_CXX17=0 + { printf "%s\n" "$as_me:${as_lineno-$LINENO}: No compiler with C++17 support was found" >&5 +printf "%s\n" "$as_me: No compiler with C++17 support was found" >&6;} else - if test x$ac_success = xno; then - HAVE_CXX11=0 - { printf "%s\n" "$as_me:${as_lineno-$LINENO}: No compiler with C++11 support was found" >&5 -printf "%s\n" "$as_me: No compiler with C++11 support was found" >&6;} - else - HAVE_CXX11=1 - -printf "%s\n" "#define HAVE_CXX11 1" >>confdefs.h - - fi + HAVE_CXX17=1 +printf "%s\n" "#define HAVE_CXX17 1" >>confdefs.h fi + WARN_CXXFLAGS= ac_ext=cpp ac_cpp='$CXXCPP $CPPFLAGS' diff --git a/configure.ac b/configure.ac index 462d0436..69e23545 100644 --- a/configure.ac +++ b/configure.ac @@ -75,7 +75,7 @@ AC_CHECK_FUNCS([arc4random getcontext getrandom memfd_create]) AM_CONDITIONAL([HAVE_GETCONTEXT], [test "x$ac_cv_func_getcontext" = xyes]) AM_CONDITIONAL([HAVE_MEMFD_CREATE], [test "x$ac_cv_func_memfd_create" = xyes]) -AX_CXX_COMPILE_STDCXX(11, noext, mandatory) +AX_CXX_COMPILE_STDCXX(17, noext, mandatory) dnl Test supported warning flags. WARN_CXXFLAGS= diff --git a/m4/ax_cxx_compile_stdcxx.m4 b/m4/ax_cxx_compile_stdcxx.m4 index 079e17d2..a3d964c6 100644 --- a/m4/ax_cxx_compile_stdcxx.m4 +++ b/m4/ax_cxx_compile_stdcxx.m4 @@ -1,5 +1,5 @@ # =========================================================================== -# http://www.gnu.org/software/autoconf-archive/ax_cxx_compile_stdcxx.html +# https://www.gnu.org/software/autoconf-archive/ax_cxx_compile_stdcxx.html # =========================================================================== # # SYNOPSIS @@ -9,14 +9,14 @@ # DESCRIPTION # # Check for baseline language coverage in the compiler for the specified -# version of the C++ standard. If necessary, add switches to CXXFLAGS to -# enable support. VERSION may be '11' (for the C++11 standard) or '14' -# (for the C++14 standard). +# version of the C++ standard. If necessary, add switches to CXX and +# CXXCPP to enable support. VERSION may be '11', '14', '17', or '20' for +# the respective C++ standard version. # # The second argument, if specified, indicates whether you insist on an # extended mode (e.g. -std=gnu++11) or a strict conformance mode (e.g. # -std=c++11). If neither is specified, you get whatever works, with -# preference for an extended mode. +# preference for no added switch, and then for an extended mode. # # The third argument, if specified 'mandatory' or if left unspecified, # indicates that baseline support for the specified C++ standard is @@ -33,21 +33,26 @@ # Copyright (c) 2014, 2015 Google Inc.; contributed by Alexey Sokolov # Copyright (c) 2015 Paul Norman # Copyright (c) 2015 Moritz Klammler +# Copyright (c) 2016, 2018 Krzesimir Nowak +# Copyright (c) 2019 Enji Cooper +# Copyright (c) 2020 Jason Merrill +# Copyright (c) 2021 Jörn Heusipp # # Copying and distribution of this file, with or without modification, are # permitted in any medium without royalty provided the copyright notice # and this notice are preserved. This file is offered as-is, without any # warranty. -#serial 1 +#serial 15 dnl This macro is based on the code from the AX_CXX_COMPILE_STDCXX_11 macro dnl (serial version number 13). AC_DEFUN([AX_CXX_COMPILE_STDCXX], [dnl - m4_if([$1], [11], [], - [$1], [14], [], - [$1], [17], [m4_fatal([support for C++17 not yet implemented in AX_CXX_COMPILE_STDCXX])], + m4_if([$1], [11], [ax_cxx_compile_alternatives="11 0x"], + [$1], [14], [ax_cxx_compile_alternatives="14 1y"], + [$1], [17], [ax_cxx_compile_alternatives="17 1z"], + [$1], [20], [ax_cxx_compile_alternatives="20"], [m4_fatal([invalid first argument `$1' to AX_CXX_COMPILE_STDCXX])])dnl m4_if([$2], [], [], [$2], [ext], [], @@ -59,29 +64,35 @@ 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 - AC_CACHE_CHECK(whether $CXX supports C++$1 features by default, - ax_cv_cxx_compile_cxx$1, - [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 - ac_success=yes - fi + + m4_if([$2], [], [dnl + AC_CACHE_CHECK(whether $CXX supports C++$1 features by default, + ax_cv_cxx_compile_cxx$1, + [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 + ac_success=yes + fi]) m4_if([$2], [noext], [], [dnl if test x$ac_success = xno; then - for switch in -std=gnu++$1 -std=gnu++0x; do + for alternative in ${ax_cxx_compile_alternatives}; do + switch="-std=gnu++${alternative}" cachevar=AS_TR_SH([ax_cv_cxx_compile_cxx$1_$switch]) AC_CACHE_CHECK(whether $CXX supports C++$1 features with $switch, $cachevar, - [ac_save_CXXFLAGS="$CXXFLAGS" - CXXFLAGS="$CXXFLAGS $switch" + [ac_save_CXX="$CXX" + CXX="$CXX $switch" AC_COMPILE_IFELSE([AC_LANG_SOURCE([_AX_CXX_COMPILE_STDCXX_testbody_$1])], [eval $cachevar=yes], [eval $cachevar=no]) - CXXFLAGS="$ac_save_CXXFLAGS"]) + CXX="$ac_save_CXX"]) if eval test x\$$cachevar = xyes; then - CXXFLAGS="$CXXFLAGS $switch" + CXX="$CXX $switch" + if test -n "$CXXCPP" ; then + CXXCPP="$CXXCPP $switch" + fi ac_success=yes break fi @@ -93,19 +104,27 @@ AC_DEFUN([AX_CXX_COMPILE_STDCXX], [dnl dnl HP's aCC needs +std=c++11 according to: dnl http://h21007.www2.hp.com/portal/download/files/unprot/aCxx/PDF_Release_Notes/769149-001.pdf dnl Cray's crayCC needs "-h std=c++11" - for switch in -std=c++$1 -std=c++0x +std=c++$1 "-h std=c++$1"; do - cachevar=AS_TR_SH([ax_cv_cxx_compile_cxx$1_$switch]) - AC_CACHE_CHECK(whether $CXX supports C++$1 features with $switch, - $cachevar, - [ac_save_CXXFLAGS="$CXXFLAGS" - CXXFLAGS="$CXXFLAGS $switch" - AC_COMPILE_IFELSE([AC_LANG_SOURCE([_AX_CXX_COMPILE_STDCXX_testbody_$1])], - [eval $cachevar=yes], - [eval $cachevar=no]) - CXXFLAGS="$ac_save_CXXFLAGS"]) - if eval test x\$$cachevar = xyes; then - CXXFLAGS="$CXXFLAGS $switch" - ac_success=yes + 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]) + AC_CACHE_CHECK(whether $CXX supports C++$1 features with $switch, + $cachevar, + [ac_save_CXX="$CXX" + CXX="$CXX $switch" + AC_COMPILE_IFELSE([AC_LANG_SOURCE([_AX_CXX_COMPILE_STDCXX_testbody_$1])], + [eval $cachevar=yes], + [eval $cachevar=no]) + CXX="$ac_save_CXX"]) + 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 @@ -115,18 +134,16 @@ AC_DEFUN([AX_CXX_COMPILE_STDCXX], [dnl if test x$ac_success = xno; then AC_MSG_ERROR([*** A compiler with support for C++$1 language features is required.]) fi - else - if test x$ac_success = xno; then - HAVE_CXX$1=0 - AC_MSG_NOTICE([No compiler with C++$1 support was found]) - else - HAVE_CXX$1=1 - AC_DEFINE(HAVE_CXX$1,1, - [define if the compiler supports basic C++$1 syntax]) - fi - - AC_SUBST(HAVE_CXX$1) fi + if test x$ac_success = xno; then + HAVE_CXX$1=0 + AC_MSG_NOTICE([No compiler with C++$1 support was found]) + else + HAVE_CXX$1=1 + AC_DEFINE(HAVE_CXX$1,1, + [define if the compiler supports basic C++$1 syntax]) + fi + AC_SUBST(HAVE_CXX$1) ]) @@ -136,7 +153,6 @@ m4_define([_AX_CXX_COMPILE_STDCXX_testbody_11], _AX_CXX_COMPILE_STDCXX_testbody_new_in_11 ) - dnl Test body for checking C++14 support m4_define([_AX_CXX_COMPILE_STDCXX_testbody_14], @@ -144,6 +160,23 @@ m4_define([_AX_CXX_COMPILE_STDCXX_testbody_14], _AX_CXX_COMPILE_STDCXX_testbody_new_in_14 ) +dnl Test body for checking C++17 support + +m4_define([_AX_CXX_COMPILE_STDCXX_testbody_17], + _AX_CXX_COMPILE_STDCXX_testbody_new_in_11 + _AX_CXX_COMPILE_STDCXX_testbody_new_in_14 + _AX_CXX_COMPILE_STDCXX_testbody_new_in_17 +) + +dnl Test body for checking C++20 support + +m4_define([_AX_CXX_COMPILE_STDCXX_testbody_20], + _AX_CXX_COMPILE_STDCXX_testbody_new_in_11 + _AX_CXX_COMPILE_STDCXX_testbody_new_in_14 + _AX_CXX_COMPILE_STDCXX_testbody_new_in_17 + _AX_CXX_COMPILE_STDCXX_testbody_new_in_20 +) + dnl Tests for new features in C++11 @@ -156,7 +189,11 @@ m4_define([_AX_CXX_COMPILE_STDCXX_testbody_new_in_11], [[ #error "This is not a C++ compiler" -#elif __cplusplus < 201103L +// MSVC always sets __cplusplus to 199711L in older versions; newer versions +// only set it correctly if /Zc:__cplusplus is specified as well as a +// /std:c++NN switch: +// https://devblogs.microsoft.com/cppblog/msvc-now-correctly-reports-__cplusplus/ +#elif __cplusplus < 201103L && !defined _MSC_VER #error "This is not a C++11 compiler" @@ -181,11 +218,13 @@ namespace cxx11 struct Base { + virtual ~Base() {} virtual void f() {} }; struct Derived : public Base { + virtual ~Derived() override {} virtual void f() override {} }; @@ -445,7 +484,7 @@ m4_define([_AX_CXX_COMPILE_STDCXX_testbody_new_in_14], [[ #error "This is not a C++ compiler" -#elif __cplusplus < 201402L +#elif __cplusplus < 201402L && !defined _MSC_VER #error "This is not a C++14 compiler" @@ -514,7 +553,7 @@ namespace cxx14 } - namespace test_digit_seperators + namespace test_digit_separators { constexpr auto ten_million = 100'000'000; @@ -556,3 +595,415 @@ namespace cxx14 #endif // __cplusplus >= 201402L ]]) + + +dnl Tests for new features in C++17 + +m4_define([_AX_CXX_COMPILE_STDCXX_testbody_new_in_17], [[ + +// If the compiler admits that it is not ready for C++17, why torture it? +// Hopefully, this will speed up the test. + +#ifndef __cplusplus + +#error "This is not a C++ compiler" + +#elif __cplusplus < 201703L && !defined _MSC_VER + +#error "This is not a C++17 compiler" + +#else + +#include +#include +#include + +namespace cxx17 +{ + + namespace test_constexpr_lambdas + { + + constexpr int foo = [](){return 42;}(); + + } + + namespace test::nested_namespace::definitions + { + + } + + namespace test_fold_expression + { + + template + int multiply(Args... args) + { + return (args * ... * 1); + } + + template + bool all(Args... args) + { + return (args && ...); + } + + } + + namespace test_extended_static_assert + { + + static_assert (true); + + } + + namespace test_auto_brace_init_list + { + + auto foo = {5}; + auto bar {5}; + + static_assert(std::is_same, decltype(foo)>::value); + static_assert(std::is_same::value); + } + + namespace test_typename_in_template_template_parameter + { + + template typename X> struct D; + + } + + namespace test_fallthrough_nodiscard_maybe_unused_attributes + { + + int f1() + { + return 42; + } + + [[nodiscard]] int f2() + { + [[maybe_unused]] auto unused = f1(); + + switch (f1()) + { + case 17: + f1(); + [[fallthrough]]; + case 42: + f1(); + } + return f1(); + } + + } + + namespace test_extended_aggregate_initialization + { + + struct base1 + { + int b1, b2 = 42; + }; + + struct base2 + { + base2() { + b3 = 42; + } + int b3; + }; + + struct derived : base1, base2 + { + int d; + }; + + derived d1 {{1, 2}, {}, 4}; // full initialization + derived d2 {{}, {}, 4}; // value-initialized bases + + } + + namespace test_general_range_based_for_loop + { + + struct iter + { + int i; + + int& operator* () + { + return i; + } + + const int& operator* () const + { + return i; + } + + iter& operator++() + { + ++i; + return *this; + } + }; + + struct sentinel + { + int i; + }; + + bool operator== (const iter& i, const sentinel& s) + { + return i.i == s.i; + } + + bool operator!= (const iter& i, const sentinel& s) + { + return !(i == s); + } + + struct range + { + iter begin() const + { + return {0}; + } + + sentinel end() const + { + return {5}; + } + }; + + void f() + { + range r {}; + + for (auto i : r) + { + [[maybe_unused]] auto v = i; + } + } + + } + + namespace test_lambda_capture_asterisk_this_by_value + { + + struct t + { + int i; + int foo() + { + return [*this]() + { + return i; + }(); + } + }; + + } + + namespace test_enum_class_construction + { + + enum class byte : unsigned char + {}; + + byte foo {42}; + + } + + namespace test_constexpr_if + { + + template + int f () + { + if constexpr(cond) + { + return 13; + } + else + { + return 42; + } + } + + } + + namespace test_selection_statement_with_initializer + { + + int f() + { + return 13; + } + + int f2() + { + if (auto i = f(); i > 0) + { + return 3; + } + + switch (auto i = f(); i + 4) + { + case 17: + return 2; + + default: + return 1; + } + } + + } + + namespace test_template_argument_deduction_for_class_templates + { + + template + struct pair + { + pair (T1 p1, T2 p2) + : m1 {p1}, + m2 {p2} + {} + + T1 m1; + T2 m2; + }; + + void f() + { + [[maybe_unused]] auto p = pair{13, 42u}; + } + + } + + namespace test_non_type_auto_template_parameters + { + + template + struct B + {}; + + B<5> b1; + B<'a'> b2; + + } + + namespace test_structured_bindings + { + + int arr[2] = { 1, 2 }; + std::pair pr = { 1, 2 }; + + auto f1() -> int(&)[2] + { + return arr; + } + + auto f2() -> std::pair& + { + return pr; + } + + struct S + { + int x1 : 2; + volatile double y1; + }; + + S f3() + { + return {}; + } + + auto [ x1, y1 ] = f1(); + auto& [ xr1, yr1 ] = f1(); + auto [ x2, y2 ] = f2(); + auto& [ xr2, yr2 ] = f2(); + const auto [ x3, y3 ] = f3(); + + } + + namespace test_exception_spec_type_system + { + + struct Good {}; + struct Bad {}; + + void g1() noexcept; + void g2(); + + template + Bad + f(T*, T*); + + template + Good + f(T1*, T2*); + + static_assert (std::is_same_v); + + } + + namespace test_inline_variables + { + + template void f(T) + {} + + template inline T g(T) + { + return T{}; + } + + template<> inline void f<>(int) + {} + + template<> int g<>(int) + { + return 5; + } + + } + +} // namespace cxx17 + +#endif // __cplusplus < 201703L && !defined _MSC_VER + +]]) + + +dnl Tests for new features in C++20 + +m4_define([_AX_CXX_COMPILE_STDCXX_testbody_new_in_20], [[ + +#ifndef __cplusplus + +#error "This is not a C++ compiler" + +#elif __cplusplus < 202002L && !defined _MSC_VER + +#error "This is not a C++20 compiler" + +#else + +#include + +namespace cxx20 +{ + +// As C++20 supports feature test macros in the standard, there is no +// immediate need to actually test for feature availability on the +// Autoconf side. + +} // namespace cxx20 + +#endif // __cplusplus < 202002L && !defined _MSC_VER + +]]) diff --git a/src/config.h.in b/src/config.h.in index 940358cf..8fd7b0aa 100644 --- a/src/config.h.in +++ b/src/config.h.in @@ -6,8 +6,8 @@ /* Define to 1 if you have the header file. */ #undef HAVE_A_OUT_H -/* define if the compiler supports basic C++11 syntax */ -#undef HAVE_CXX11 +/* define if the compiler supports basic C++17 syntax */ +#undef HAVE_CXX17 /* Define to 1 if you have the `getcontext' function. */ #undef HAVE_GETCONTEXT