[libc++] Add hide_from_abi check for classes

We already have a clang-tidy check for making sure that `_LIBCPP_HIDE_FROM_ABI` is on free functions. This patch extends this to class members. The places where we don't check for `_LIBCPP_HIDE_FROM_ABI` are classes for which we have an instantiation in the library.

Reviewed By: ldionne, Mordante, #libc

Spies: jplehr, mikhail.ramalho, sstefan1, libcxx-commits, krytarowski, miyuki, smeenai

Differential Revision: https://reviews.llvm.org/D142332

Author: philnik777

libcxx/include/__algorithm/comp_ref_type.h

@@ -23,11 +23,10 @@ template <class _Compare>
 struct __debug_less
 {
     _Compare &__comp_;
-    _LIBCPP_CONSTEXPR_SINCE_CXX14
-    __debug_less(_Compare& __c) : __comp_(__c) {}
+    _LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_HIDE_FROM_ABI __debug_less(_Compare& __c) : __comp_(__c) {}
 
     template <class _Tp, class _Up>
-    _LIBCPP_CONSTEXPR_SINCE_CXX14
+    _LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_HIDE_FROM_ABI
     bool operator()(const _Tp& __x,  const _Up& __y)
     {
         bool __r = __comp_(__x, __y);
@@ -37,7 +36,7 @@ struct __debug_less
     }
 
     template <class _Tp, class _Up>
-    _LIBCPP_CONSTEXPR_SINCE_CXX14
+    _LIBCPP_CONSTEXPR_SINCE_CXX14 _LIBCPP_HIDE_FROM_ABI
     bool operator()(_Tp& __x,  _Up& __y)
     {
         bool __r = __comp_(__x, __y);

libcxx/include/__algorithm/make_projected.h

@@ -32,13 +32,14 @@ struct _ProjectedPred {
   _Pred& __pred; // Can be a unary or a binary predicate.
   _Proj& __proj;
 
-  _LIBCPP_CONSTEXPR _ProjectedPred(_Pred& __pred_arg, _Proj& __proj_arg) : __pred(__pred_arg), __proj(__proj_arg) {}
+  _LIBCPP_CONSTEXPR _LIBCPP_HIDE_FROM_ABI _ProjectedPred(_Pred& __pred_arg, _Proj& __proj_arg)
+      : __pred(__pred_arg), __proj(__proj_arg) {}
 
   template <class _Tp>
   typename __invoke_of<_Pred&,
                        decltype(std::__invoke(std::declval<_Proj&>(), std::declval<_Tp>()))
   >::type
-  _LIBCPP_CONSTEXPR operator()(_Tp&& __v) const {
+  _LIBCPP_CONSTEXPR _LIBCPP_HIDE_FROM_ABI operator()(_Tp&& __v) const {
     return std::__invoke(__pred, std::__invoke(__proj, std::forward<_Tp>(__v)));
   }
 
@@ -47,7 +48,7 @@ struct _ProjectedPred {
                        decltype(std::__invoke(std::declval<_Proj&>(), std::declval<_T1>())),
                        decltype(std::__invoke(std::declval<_Proj&>(), std::declval<_T2>()))
   >::type
-  _LIBCPP_CONSTEXPR operator()(_T1&& __lhs, _T2&& __rhs) const {
+  _LIBCPP_CONSTEXPR _LIBCPP_HIDE_FROM_ABI operator()(_T1&& __lhs, _T2&& __rhs) const {
     return std::__invoke(__pred,
                       std::__invoke(__proj, std::forward<_T1>(__lhs)),
                       std::__invoke(__proj, std::forward<_T2>(__rhs)));

libcxx/include/__algorithm/shuffle.h

@@ -31,7 +31,7 @@ _LIBCPP_BEGIN_NAMESPACE_STD
 
 class _LIBCPP_TYPE_VIS __libcpp_debug_randomizer {
 public:
-  __libcpp_debug_randomizer() {
+  _LIBCPP_HIDE_FROM_ABI __libcpp_debug_randomizer() {
     __state_ = __seed();
     __inc_ = __state_ + 0xda3e39cb94b95bdbULL;
     __inc_ = (__inc_ << 1) | 1;
@@ -85,8 +85,8 @@ class _LIBCPP_TYPE_VIS __rs_default
 
     result_type operator()();
 
-    static _LIBCPP_CONSTEXPR result_type min() {return _Min;}
-    static _LIBCPP_CONSTEXPR result_type max() {return _Max;}
+    static _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR result_type min() {return _Min;}
+    static _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR result_type max() {return _Max;}
 
     friend _LIBCPP_FUNC_VIS __rs_default __rs_get();
 };

libcxx/include/__atomic/atomic_flag.h

@@ -71,7 +71,6 @@ struct atomic_flag
     _LIBCPP_HIDE_FROM_ABI constexpr
     atomic_flag() _NOEXCEPT : __a_(false) {}
 #else
-    _LIBCPP_HIDE_FROM_ABI
     atomic_flag() _NOEXCEPT = default;
 #endif
 

libcxx/include/__chrono/calendar.h

@@ -31,7 +31,7 @@ using local_time  = time_point<local_t, Duration>;
 using local_seconds = local_time<seconds>;
 using local_days    = local_time<days>;
 
-struct last_spec { _LIBCPP_HIDE_FROM_ABI explicit last_spec() = default; };
+struct last_spec { explicit last_spec() = default; };
 inline constexpr last_spec last{};
 
 

libcxx/include/__chrono/day.h

@@ -29,7 +29,7 @@ class day {
 private:
     unsigned char __d_;
 public:
-    _LIBCPP_HIDE_FROM_ABI day() = default;
+    day() = default;
     _LIBCPP_HIDE_FROM_ABI explicit inline constexpr day(unsigned __val) noexcept : __d_(static_cast<unsigned char>(__val)) {}
     _LIBCPP_HIDE_FROM_ABI inline constexpr day& operator++()    noexcept { ++__d_; return *this; }
     _LIBCPP_HIDE_FROM_ABI inline constexpr day  operator++(int) noexcept { day __tmp = *this; ++(*this); return __tmp; }

libcxx/include/__chrono/duration.h

@@ -244,11 +244,10 @@ class _LIBCPP_TEMPLATE_VIS duration
     rep __rep_;
 public:
 
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
 #ifndef _LIBCPP_CXX03_LANG
-        duration() = default;
+        constexpr duration() = default;
 #else
-        duration() {}
+        _LIBCPP_HIDE_FROM_ABI duration() {}
 #endif
 
     template <class _Rep2>

libcxx/include/__chrono/month.h

@@ -29,7 +29,7 @@ class month {
 private:
     unsigned char __m_;
 public:
-    _LIBCPP_HIDE_FROM_ABI month() = default;
+    month() = default;
     _LIBCPP_HIDE_FROM_ABI explicit inline constexpr month(unsigned __val) noexcept : __m_(static_cast<unsigned char>(__val)) {}
     _LIBCPP_HIDE_FROM_ABI inline constexpr month& operator++()    noexcept { ++__m_; return *this; }
     _LIBCPP_HIDE_FROM_ABI inline constexpr month  operator++(int) noexcept { month __tmp = *this; ++(*this); return __tmp; }

libcxx/include/__chrono/monthday.h

@@ -32,7 +32,7 @@ class month_day {
    chrono::month __m_;
    chrono::day   __d_;
 public:
-    _LIBCPP_HIDE_FROM_ABI month_day() = default;
+    month_day() = default;
     _LIBCPP_HIDE_FROM_ABI constexpr month_day(const chrono::month& __mval, const chrono::day& __dval) noexcept
         : __m_{__mval}, __d_{__dval} {}
     _LIBCPP_HIDE_FROM_ABI inline constexpr chrono::month month() const noexcept { return __m_; }

libcxx/include/__chrono/weekday.h

@@ -35,7 +35,7 @@ class weekday {
     unsigned char __wd_;
     _LIBCPP_HIDE_FROM_ABI static constexpr unsigned char __weekday_from_days(int __days) noexcept;
 public:
-  _LIBCPP_HIDE_FROM_ABI weekday() = default;
+  weekday() = default;
   _LIBCPP_HIDE_FROM_ABI inline explicit constexpr weekday(unsigned __val) noexcept : __wd_(static_cast<unsigned char>(__val == 7 ? 0 : __val)) {}
   _LIBCPP_HIDE_FROM_ABI inline constexpr          weekday(const sys_days& __sysd) noexcept
           : __wd_(__weekday_from_days(__sysd.time_since_epoch().count())) {}
@@ -126,7 +126,7 @@ class weekday_indexed {
     chrono::weekday __wd_;
     unsigned char   __idx_;
 public:
-    _LIBCPP_HIDE_FROM_ABI weekday_indexed() = default;
+    weekday_indexed() = default;
     _LIBCPP_HIDE_FROM_ABI inline constexpr weekday_indexed(const chrono::weekday& __wdval, unsigned __idxval) noexcept
         : __wd_{__wdval}, __idx_(__idxval) {}
     _LIBCPP_HIDE_FROM_ABI inline constexpr chrono::weekday weekday() const noexcept { return __wd_; }