binutils-gdb/gdb/ax_cxx_compile_stdcxx.m4
Joel Brobecker 61baf725ec update copyright year range in GDB files
This applies the second part of GDB's End of Year Procedure, which
updates the copyright year range in all of GDB's files.

gdb/ChangeLog:

        Update copyright year range in all GDB files.
2017-01-01 10:52:34 +04:00

568 lines
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# Copyright (c) 2016-2017 Free Software Foundation, Inc.
#
# Originally based on the AX_CXX_COMPILE_STDCXX macro found at the url
# below.
#
# Local GDB customizations:
#
# - AC_SUBST CXX_DIALECT instead of changing CXX/CXXCPP.
#
# ===========================================================================
# http://www.gnu.org/software/autoconf-archive/ax_cxx_compile_stdcxx.html
# ===========================================================================
#
# SYNOPSIS
#
# AX_CXX_COMPILE_STDCXX(VERSION, [ext|noext], [mandatory|optional])
#
# DESCRIPTION
#
# Check for baseline language coverage in the compiler for the specified
# version of the C++ standard. If necessary, add switches to CXX and
# CXXCPP to enable support. VERSION may be '11' (for the C++11 standard)
# or '14' (for the C++14 standard).
#
# 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.
#
# The third argument, if specified 'mandatory' or if left unspecified,
# indicates that baseline support for the specified C++ standard is
# required and that the macro should error out if no mode with that
# support is found. If specified 'optional', then configuration proceeds
# regardless, after defining HAVE_CXX${VERSION} if and only if a
# supporting mode is found.
#
# LICENSE
#
# Copyright (c) 2008 Benjamin Kosnik <bkoz@redhat.com>
# Copyright (c) 2012 Zack Weinberg <zackw@panix.com>
# Copyright (c) 2013 Roy Stogner <roystgnr@ices.utexas.edu>
# Copyright (c) 2014, 2015 Google Inc.; contributed by Alexey Sokolov <sokolov@google.com>
# Copyright (c) 2015 Paul Norman <penorman@mac.com>
# Copyright (c) 2015 Moritz Klammler <moritz@klammler.eu>
#
# 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 4
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_fatal([invalid first argument `$1' to AX_CXX_COMPILE_STDCXX])])dnl
m4_if([$2], [], [],
[$2], [ext], [],
[$2], [noext], [],
[m4_fatal([invalid second argument `$2' to AX_CXX_COMPILE_STDCXX])])dnl
m4_if([$3], [], [ax_cxx_compile_cxx$1_required=true],
[$3], [mandatory], [ax_cxx_compile_cxx$1_required=true],
[$3], [optional], [ax_cxx_compile_cxx$1_required=false],
[m4_fatal([invalid third argument `$3' to AX_CXX_COMPILE_STDCXX])])
AC_LANG_PUSH([C++])dnl
CXX_DIALECT=""
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([$2], [noext], [], [dnl
if test x$ac_success = xno; then
for switch in -std=gnu++$1 -std=gnu++0x; 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_DIALECT="$switch"
ac_success=yes
break
fi
done
fi])
m4_if([$2], [ext], [], [dnl
if test x$ac_success = xno; then
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,
$cachevar,
[ac_save_CXX="$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_DIALECT="$switch"
ac_success=yes
break
fi
done
fi])
AC_LANG_POP([C++])
if test x$ax_cxx_compile_cxx$1_required = xtrue; then
if test x$ac_success = xno; then
AC_MSG_ERROR([*** A compiler with support for C++$1 language features is required.])
fi
fi
if test x$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)
AC_SUBST(CXX_DIALECT)
])
dnl Test body for checking C++11 support
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],
_AX_CXX_COMPILE_STDCXX_testbody_new_in_11
_AX_CXX_COMPILE_STDCXX_testbody_new_in_14
)
dnl Tests for new features in C++11
m4_define([_AX_CXX_COMPILE_STDCXX_testbody_new_in_11], [[
// 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 void f() {}
};
struct Derived : public Base
{
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
]])
dnl Tests for new features in C++14
m4_define([_AX_CXX_COMPILE_STDCXX_testbody_new_in_14], [[
// 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
#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_seperators
{
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<T, T>
{
static constexpr auto value = true;
};
int
test()
{
auto x = 0;
static_assert(is_same<int, decltype(f(x))>::value, "");
static_assert(is_same<int&, decltype(g(x))>::value, "");
return x;
}
}
} // namespace cxx14
#endif // __cplusplus >= 201402L
]])