[libcxx] Fix PR23589: std::function doesn't recognize null pointer to varargs function.

Summary:
This patch fixes __not_null's detection of nullptr by breaking it down into 4 cases.

1. `__not_null(Tp const&)`: Default case. Tp is not null.
2. `__not_null(Tp* __ptr);` Case for pointers to functions.
3. `__not_null(_Ret _Class::* __ptr);` Case for pointers to members.
4. `__not_null(function<Tp> const&);`: Cases for other std::functions.

Reviewers: mclow.lists

Subscribers: cfe-commits

Differential Revision: http://reviews.llvm.org/D11111

llvm-svn: 245335

1 files changed, 8 insertions, 80 deletions

diff --git a/libcxx/include/__functional_03 b/libcxx/include/__functional_03
index 56a84753af3..4edbb0996ca 100644
--- a/libcxx/include/__functional_03
+++ b/libcxx/include/__functional_03
@@ -451,15 +451,6 @@ class _LIBCPP_TYPE_VIS_ONLY function<_Rp()>
     aligned_storage<3*sizeof(void*)>::type __buf_;
     __base* __f_;
 
-    template <class _Fp>
-        _LIBCPP_INLINE_VISIBILITY
-        static bool __not_null(const _Fp&) {return true;}
-    template <class _R2>
-        _LIBCPP_INLINE_VISIBILITY
-        static bool __not_null(_R2 (*__p)()) {return __p;}
-    template <class _R2>
-        _LIBCPP_INLINE_VISIBILITY
-        static bool __not_null(const function<_R2()>& __p) {return __p;}
 public:
     typedef _Rp result_type;
 
@@ -558,7 +549,7 @@ function<_Rp()>::function(_Fp __f,
                                      typename enable_if<!is_integral<_Fp>::value>::type*)
     : __f_(0)
 {
-    if (__not_null(__f))
+    if (__function::__not_null(__f))
     {
         typedef __function::__func<_Fp, allocator<_Fp>, _Rp()> _FF;
         if (sizeof(_FF) <= sizeof(__buf_))
@@ -585,7 +576,7 @@ function<_Rp()>::function(allocator_arg_t, const _Alloc& __a0, _Fp __f,
     : __f_(0)
 {
     typedef allocator_traits<_Alloc> __alloc_traits;
-    if (__not_null(__f))
+    if (__function::__not_null(__f))
     {
         typedef __function::__func<_Fp, _Alloc, _Rp()> _FF;
         if (sizeof(_FF) <= sizeof(__buf_))
@@ -736,27 +727,6 @@ class _LIBCPP_TYPE_VIS_ONLY function<_Rp(_A0)>
     aligned_storage<3*sizeof(void*)>::type __buf_;
     __base* __f_;
 
-    template <class _Fp>
-        _LIBCPP_INLINE_VISIBILITY
-        static bool __not_null(const _Fp&) {return true;}
-    template <class _R2, class _B0>
-        _LIBCPP_INLINE_VISIBILITY
-        static bool __not_null(_R2 (*__p)(_B0)) {return __p;}
-    template <class _R2, class _Cp>
-        _LIBCPP_INLINE_VISIBILITY
-        static bool __not_null(_R2 (_Cp::*__p)()) {return __p;}
-    template <class _R2, class _Cp>
-        _LIBCPP_INLINE_VISIBILITY
-        static bool __not_null(_R2 (_Cp::*__p)() const) {return __p;}
-    template <class _R2, class _Cp>
-        _LIBCPP_INLINE_VISIBILITY
-        static bool __not_null(_R2 (_Cp::*__p)() volatile) {return __p;}
-    template <class _R2, class _Cp>
-        _LIBCPP_INLINE_VISIBILITY
-        static bool __not_null(_R2 (_Cp::*__p)() const volatile) {return __p;}
-    template <class _R2, class _B0>
-        _LIBCPP_INLINE_VISIBILITY
-        static bool __not_null(const function<_R2(_B0)>& __p) {return __p;}
 public:
     typedef _Rp result_type;
 
@@ -855,7 +825,7 @@ function<_Rp(_A0)>::function(_Fp __f,
                                      typename enable_if<!is_integral<_Fp>::value>::type*)
     : __f_(0)
 {
-    if (__not_null(__f))
+    if (__function::__not_null(__f))
     {
         typedef __function::__func<_Fp, allocator<_Fp>, _Rp(_A0)> _FF;
         if (sizeof(_FF) <= sizeof(__buf_))
@@ -882,7 +852,7 @@ function<_Rp(_A0)>::function(allocator_arg_t, const _Alloc& __a0, _Fp __f,
     : __f_(0)
 {
     typedef allocator_traits<_Alloc> __alloc_traits;
-    if (__not_null(__f))
+    if (__function::__not_null(__f))
     {
         typedef __function::__func<_Fp, _Alloc, _Rp(_A0)> _FF;
         if (sizeof(_FF) <= sizeof(__buf_))
@@ -1033,27 +1003,6 @@ class _LIBCPP_TYPE_VIS_ONLY function<_Rp(_A0, _A1)>
     aligned_storage<3*sizeof(void*)>::type __buf_;
     __base* __f_;
 
-    template <class _Fp>
-        _LIBCPP_INLINE_VISIBILITY
-        static bool __not_null(const _Fp&) {return true;}
-    template <class _R2, class _B0, class _B1>
-        _LIBCPP_INLINE_VISIBILITY
-        static bool __not_null(_R2 (*__p)(_B0, _B1)) {return __p;}
-    template <class _R2, class _Cp, class _B1>
-        _LIBCPP_INLINE_VISIBILITY
-        static bool __not_null(_R2 (_Cp::*__p)(_B1)) {return __p;}
-    template <class _R2, class _Cp, class _B1>
-        _LIBCPP_INLINE_VISIBILITY
-        static bool __not_null(_R2 (_Cp::*__p)(_B1) const) {return __p;}
-    template <class _R2, class _Cp, class _B1>
-        _LIBCPP_INLINE_VISIBILITY
-        static bool __not_null(_R2 (_Cp::*__p)(_B1) volatile) {return __p;}
-    template <class _R2, class _Cp, class _B1>
-        _LIBCPP_INLINE_VISIBILITY
-        static bool __not_null(_R2 (_Cp::*__p)(_B1) const volatile) {return __p;}
-    template <class _R2, class _B0, class _B1>
-        _LIBCPP_INLINE_VISIBILITY
-        static bool __not_null(const function<_R2(_B0, _B1)>& __p) {return __p;}
 public:
     typedef _Rp result_type;
 
@@ -1152,7 +1101,7 @@ function<_Rp(_A0, _A1)>::function(_Fp __f,
                                  typename enable_if<!is_integral<_Fp>::value>::type*)
     : __f_(0)
 {
-    if (__not_null(__f))
+    if (__function::__not_null(__f))
     {
         typedef __function::__func<_Fp, allocator<_Fp>, _Rp(_A0, _A1)> _FF;
         if (sizeof(_FF) <= sizeof(__buf_))
@@ -1179,7 +1128,7 @@ function<_Rp(_A0, _A1)>::function(allocator_arg_t, const _Alloc& __a0, _Fp __f,
     : __f_(0)
 {
     typedef allocator_traits<_Alloc> __alloc_traits;
-    if (__not_null(__f))
+    if (__function::__not_null(__f))
     {
         typedef __function::__func<_Fp, _Alloc, _Rp(_A0, _A1)> _FF;
         if (sizeof(_FF) <= sizeof(__buf_))
@@ -1329,27 +1278,6 @@ class _LIBCPP_TYPE_VIS_ONLY function<_Rp(_A0, _A1, _A2)>
     aligned_storage<3*sizeof(void*)>::type __buf_;
     __base* __f_;
 
-    template <class _Fp>
-        _LIBCPP_INLINE_VISIBILITY
-        static bool __not_null(const _Fp&) {return true;}
-    template <class _R2, class _B0, class _B1, class _B2>
-        _LIBCPP_INLINE_VISIBILITY
-        static bool __not_null(_R2 (*__p)(_B0, _B1, _B2)) {return __p;}
-    template <class _R2, class _Cp, class _B1, class _B2>
-        _LIBCPP_INLINE_VISIBILITY
-        static bool __not_null(_R2 (_Cp::*__p)(_B1, _B2)) {return __p;}
-    template <class _R2, class _Cp, class _B1, class _B2>
-        _LIBCPP_INLINE_VISIBILITY
-        static bool __not_null(_R2 (_Cp::*__p)(_B1, _B2) const) {return __p;}
-    template <class _R2, class _Cp, class _B1, class _B2>
-        _LIBCPP_INLINE_VISIBILITY
-        static bool __not_null(_R2 (_Cp::*__p)(_B1, _B2) volatile) {return __p;}
-    template <class _R2, class _Cp, class _B1, class _B2>
-        _LIBCPP_INLINE_VISIBILITY
-        static bool __not_null(_R2 (_Cp::*__p)(_B1, _B2) const volatile) {return __p;}
-    template <class _R2, class _B0, class _B1, class _B2>
-        _LIBCPP_INLINE_VISIBILITY
-        static bool __not_null(const function<_R2(_B0, _B1, _B2)>& __p) {return __p;}
 public:
     typedef _Rp result_type;
 
@@ -1449,7 +1377,7 @@ function<_Rp(_A0, _A1, _A2)>::function(_Fp __f,
                                      typename enable_if<!is_integral<_Fp>::value>::type*)
     : __f_(0)
 {
-    if (__not_null(__f))
+    if (__function::__not_null(__f))
     {
         typedef __function::__func<_Fp, allocator<_Fp>, _Rp(_A0, _A1, _A2)> _FF;
         if (sizeof(_FF) <= sizeof(__buf_))
@@ -1476,7 +1404,7 @@ function<_Rp(_A0, _A1, _A2)>::function(allocator_arg_t, const _Alloc& __a0, _Fp
     : __f_(0)
 {
     typedef allocator_traits<_Alloc> __alloc_traits;
-    if (__not_null(__f))
+    if (__function::__not_null(__f))
     {
         typedef __function::__func<_Fp, _Alloc, _Rp(_A0, _A1, _A2)> _FF;
         if (sizeof(_FF) <= sizeof(__buf_))