[PATCH v2 1/5] Update ax_cv_cxx_compile_cxx.m4
Simon Marchi
simon.marchi@polymtl.ca
Fri Mar 30 21:47:00 GMT 2018
This file provides the AX_CXX_COMPILE_STDCXX macro. In the context of
the following patch, I wanted to build and test GDB in c++17 mode. The
version of the macro we have in the repo does not support detecting
c++17 compilers, but the upstream version has been updated to do so.
Since we have local modifications to the file, I had to reconcile our
modifications and the updated upstream version (which was relatively
straightforward).
gdb/ChangeLog:
* ax_cxx_compile_stdcxx.m4: Sync with upstream.
* configure: Re-generate.
---
gdb/ax_cxx_compile_stdcxx.m4 | 458 +++++++++++++++++++++++++++++++++++++++++--
gdb/configure | 28 +--
2 files changed, 455 insertions(+), 31 deletions(-)
diff --git a/gdb/ax_cxx_compile_stdcxx.m4 b/gdb/ax_cxx_compile_stdcxx.m4
index 444799a64678..9a9e9e713a53 100644
--- a/gdb/ax_cxx_compile_stdcxx.m4
+++ b/gdb/ax_cxx_compile_stdcxx.m4
@@ -8,7 +8,7 @@
# - AC_SUBST CXX_DIALECT instead of changing CXX/CXXCPP.
#
# ===========================================================================
-# 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
@@ -42,21 +42,22 @@
# 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>
+# Copyright (c) 2016 Krzesimir Nowak <qdlacz@gmail.com>
#
# 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
+#serial 8
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"],
[m4_fatal([invalid first argument `$1' to AX_CXX_COMPILE_STDCXX])])dnl
m4_if([$2], [], [],
[$2], [ext], [],
@@ -80,7 +81,8 @@ AC_DEFUN([AX_CXX_COMPILE_STDCXX], [dnl
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,
@@ -103,19 +105,24 @@ 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,
- $cachevar,
- [ac_save_CXX="$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
+ 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_DIALECT="$switch"
+ ac_success=yes
+ break
+ fi
+ done
+ if test x$ac_success = xyes; then
break
fi
done
@@ -153,6 +160,11 @@ m4_define([_AX_CXX_COMPILE_STDCXX_testbody_14],
_AX_CXX_COMPILE_STDCXX_testbody_new_in_14
)
+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 Tests for new features in C++11
@@ -523,7 +535,7 @@ namespace cxx14
}
- namespace test_digit_seperators
+ namespace test_digit_separators
{
constexpr auto ten_million = 100'000'000;
@@ -565,3 +577,409 @@ 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 <= 201402L
+
+#error "This is not a C++17 compiler"
+
+#else
+
+#if defined(__clang__)
+ #define REALLY_CLANG
+#else
+ #if defined(__GNUC__)
+ #define REALLY_GCC
+ #endif
+#endif
+
+#include <initializer_list>
+#include <utility>
+#include <type_traits>
+
+namespace cxx17
+{
+
+#if !defined(REALLY_CLANG)
+ namespace test_constexpr_lambdas
+ {
+
+ // TODO: test it with clang++ from git
+
+ constexpr int foo = [](){return 42;}();
+
+ }
+#endif // !defined(REALLY_CLANG)
+
+ namespace test::nested_namespace::definitions
+ {
+
+ }
+
+ namespace test_fold_expression
+ {
+
+ template<typename... Args>
+ int multiply(Args... args)
+ {
+ return (args * ... * 1);
+ }
+
+ template<typename... Args>
+ 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<std::initializer_list<int>, decltype(foo)>::value);
+ static_assert(std::is_same<int, decltype(bar)>::value);
+ }
+
+ namespace test_typename_in_template_template_parameter
+ {
+
+ template<template<typename> 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 <bool cond>
+ 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;
+ }
+ }
+
+ }
+
+#if !defined(REALLY_CLANG)
+ namespace test_template_argument_deduction_for_class_templates
+ {
+
+ // TODO: test it with clang++ from git
+
+ template <typename T1, typename T2>
+ struct pair
+ {
+ pair (T1 p1, T2 p2)
+ : m1 {p1},
+ m2 {p2}
+ {}
+
+ T1 m1;
+ T2 m2;
+ };
+
+ void f()
+ {
+ [[maybe_unused]] auto p = pair{13, 42u};
+ }
+
+ }
+#endif // !defined(REALLY_CLANG)
+
+ namespace test_non_type_auto_template_parameters
+ {
+
+ template <auto n>
+ struct B
+ {};
+
+ B<5> b1;
+ B<'a'> b2;
+
+ }
+
+#if !defined(REALLY_CLANG)
+ namespace test_structured_bindings
+ {
+
+ // TODO: test it with clang++ from git
+
+ int arr[2] = { 1, 2 };
+ std::pair<int, int> pr = { 1, 2 };
+
+ auto f1() -> int(&)[2]
+ {
+ return arr;
+ }
+
+ auto f2() -> std::pair<int, int>&
+ {
+ 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();
+
+ }
+#endif // !defined(REALLY_CLANG)
+
+#if !defined(REALLY_CLANG)
+ namespace test_exception_spec_type_system
+ {
+
+ // TODO: test it with clang++ from git
+
+ struct Good {};
+ struct Bad {};
+
+ void g1() noexcept;
+ void g2();
+
+ template<typename T>
+ Bad
+ f(T*, T*);
+
+ template<typename T1, typename T2>
+ Good
+ f(T1*, T2*);
+
+ static_assert (std::is_same_v<Good, decltype(f(g1, g2))>);
+
+ }
+#endif // !defined(REALLY_CLANG)
+
+ namespace test_inline_variables
+ {
+
+ template<class T> void f(T)
+ {}
+
+ template<class T> inline T g(T)
+ {
+ return T{};
+ }
+
+ template<> inline void f<>(int)
+ {}
+
+ template<> int g<>(int)
+ {
+ return 5;
+ }
+
+ }
+
+} // namespace cxx17
+
+#endif // __cplusplus <= 201402L
+
+]])
diff --git a/gdb/configure b/gdb/configure
index ab5818785333..12b626aee30c 100755
--- a/gdb/configure
+++ b/gdb/configure
@@ -4967,7 +4967,7 @@ program_transform_name=`$as_echo "$program_transform_name" | sed "$ac_script"`
# We require a C++11 compiler. Check if one is available, and if
# necessary, set CXX_DIALECT to some -std=xxx switch.
- ax_cxx_compile_cxx11_required=true
+ ax_cxx_compile_alternatives="11 0x" ax_cxx_compile_cxx11_required=true
ac_ext=cpp
ac_cpp='$CXXCPP $CPPFLAGS'
ac_compile='$CXX -c $CXXFLAGS $CPPFLAGS conftest.$ac_ext >&5'
@@ -5283,7 +5283,8 @@ $as_echo "$ax_cv_cxx_compile_cxx11" >&6; }
fi
if test x$ac_success = xno; then
- for switch in -std=gnu++11 -std=gnu++0x; do
+ for alternative in ${ax_cxx_compile_alternatives}; do
+ switch="-std=gnu++${alternative}"
cachevar=`$as_echo "ax_cv_cxx_compile_cxx11_$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; }
@@ -5601,16 +5602,17 @@ $as_echo "$ac_res" >&6; }
fi
if test x$ac_success = xno; then
- for switch in -std=c++11 -std=c++0x +std=c++11 "-h std=c++11"; do
- cachevar=`$as_echo "ax_cv_cxx_compile_cxx11_$switch" | $as_tr_sh`
- { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether $CXX supports C++11 features with $switch" >&5
+ for alternative in ${ax_cxx_compile_alternatives}; do
+ for switch in -std=c++${alternative} +std=c++${alternative} "-h std=c++${alternative}"; do
+ cachevar=`$as_echo "ax_cv_cxx_compile_cxx11_$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 $switch... " >&6; }
if { as_var=$cachevar; eval "test \"\${$as_var+set}\" = set"; }; then :
$as_echo_n "(cached) " >&6
else
ac_save_CXX="$CXX"
- CXX="$CXX $switch"
- cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+ CXX="$CXX $switch"
+ cat confdefs.h - <<_ACEOF >conftest.$ac_ext
/* end confdefs.h. */
@@ -5905,14 +5907,18 @@ else
eval $cachevar=no
fi
rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
- CXX="$ac_save_CXX"
+ 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_DIALECT="$switch"
- ac_success=yes
+ if eval test x\$$cachevar = xyes; then
+ CXX_DIALECT="$switch"
+ ac_success=yes
+ break
+ fi
+ done
+ if test x$ac_success = xyes; then
break
fi
done
--
2.16.3
More information about the Gdb-patches
mailing list