[libcxx-commits] [libcxx] [libc++] Rename __bit_reference template parameter to avoid conflict (PR #80661)

[Dimitry Andric via libcxx-commits]

https://github.com/DimitryAndric updated https://github.com/llvm/llvm-project/pull/80661

>From 17bd7942d8b60619d0df8a1e3021478db021532a Mon Sep 17 00:00:00 2001
From: Dimitry Andric <dimitry at andric.com>
Date: Mon, 5 Feb 2024 11:55:49 +0100
Subject: [PATCH 1/2] [libc++] Rename __bit_reference template parameter to
 avoid conflict

As of 4d20cfcf4eb08217ed37c4d4c38dc395d7a66d26, `__bit_reference`
contains a template `__fill_n` with a bool `_FillValue` parameter.

Unfortunately there is a relatively widely used piece of scientific
software called NetCDF, which exposes a (C) macro `_FillValue` in its
public headers.

When building the NetCDF C++ bindings, this quickly leads to compilation
errors when the macro interferes with the template in `__bit_reference`.

Rename the parameter to `_Fill_Value` to avoid the conflict.
---
 libcxx/include/__bit_reference | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/libcxx/include/__bit_reference b/libcxx/include/__bit_reference
index 9032b8f0180937..e0b647eb62a8a2 100644
--- a/libcxx/include/__bit_reference
+++ b/libcxx/include/__bit_reference
@@ -173,7 +173,7 @@ private:
 
 // fill_n
 
-template <bool _FillValue, class _Cp>
+template <bool _Fill_Value, class _Cp>
 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void
 __fill_n(__bit_iterator<_Cp, false> __first, typename _Cp::size_type __n) {
   using _It            = __bit_iterator<_Cp, false>;
@@ -185,7 +185,7 @@ __fill_n(__bit_iterator<_Cp, false> __first, typename _Cp::size_type __n) {
     __storage_type __clz_f = static_cast<__storage_type>(__bits_per_word - __first.__ctz_);
     __storage_type __dn    = std::min(__clz_f, __n);
     __storage_type __m     = (~__storage_type(0) << __first.__ctz_) & (~__storage_type(0) >> (__clz_f - __dn));
-    if (_FillValue)
+    if (_Fill_Value)
       *__first.__seg_ |= __m;
     else
       *__first.__seg_ &= ~__m;
@@ -194,13 +194,13 @@ __fill_n(__bit_iterator<_Cp, false> __first, typename _Cp::size_type __n) {
   }
   // do middle whole words
   __storage_type __nw = __n / __bits_per_word;
-  std::fill_n(std::__to_address(__first.__seg_), __nw, _FillValue ? static_cast<__storage_type>(-1) : 0);
+  std::fill_n(std::__to_address(__first.__seg_), __nw, _Fill_Value ? static_cast<__storage_type>(-1) : 0);
   __n -= __nw * __bits_per_word;
   // do last partial word
   if (__n > 0) {
     __first.__seg_ += __nw;
     __storage_type __m = ~__storage_type(0) >> (__bits_per_word - __n);
-    if (_FillValue)
+    if (_Fill_Value)
       *__first.__seg_ |= __m;
     else
       *__first.__seg_ &= ~__m;
@@ -1007,7 +1007,7 @@ private:
   friend class __bit_iterator<_Cp, true>;
   template <class _Dp>
   friend struct __bit_array;
-  template <bool _FillValue, class _Dp>
+  template <bool _Fill_Value, class _Dp>
   _LIBCPP_CONSTEXPR_SINCE_CXX20 friend void __fill_n(__bit_iterator<_Dp, false> __first, typename _Dp::size_type __n);
 
   template <class _Dp, bool _IC>

>From ff521d90bb73012f892889afdc7a9b5f986d2484 Mon Sep 17 00:00:00 2001
From: Dimitry Andric <dimitry at andric.com>
Date: Mon, 5 Feb 2024 17:11:02 +0100
Subject: [PATCH 2/2] Rename _Fill_Value to _FillVal to keep the style.

---
 libcxx/include/__bit_reference | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/libcxx/include/__bit_reference b/libcxx/include/__bit_reference
index e0b647eb62a8a2..3a5339b72ddc31 100644
--- a/libcxx/include/__bit_reference
+++ b/libcxx/include/__bit_reference
@@ -173,7 +173,7 @@ private:
 
 // fill_n
 
-template <bool _Fill_Value, class _Cp>
+template <bool _FillVal, class _Cp>
 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void
 __fill_n(__bit_iterator<_Cp, false> __first, typename _Cp::size_type __n) {
   using _It            = __bit_iterator<_Cp, false>;
@@ -185,7 +185,7 @@ __fill_n(__bit_iterator<_Cp, false> __first, typename _Cp::size_type __n) {
     __storage_type __clz_f = static_cast<__storage_type>(__bits_per_word - __first.__ctz_);
     __storage_type __dn    = std::min(__clz_f, __n);
     __storage_type __m     = (~__storage_type(0) << __first.__ctz_) & (~__storage_type(0) >> (__clz_f - __dn));
-    if (_Fill_Value)
+    if (_FillVal)
       *__first.__seg_ |= __m;
     else
       *__first.__seg_ &= ~__m;
@@ -194,13 +194,13 @@ __fill_n(__bit_iterator<_Cp, false> __first, typename _Cp::size_type __n) {
   }
   // do middle whole words
   __storage_type __nw = __n / __bits_per_word;
-  std::fill_n(std::__to_address(__first.__seg_), __nw, _Fill_Value ? static_cast<__storage_type>(-1) : 0);
+  std::fill_n(std::__to_address(__first.__seg_), __nw, _FillVal ? static_cast<__storage_type>(-1) : 0);
   __n -= __nw * __bits_per_word;
   // do last partial word
   if (__n > 0) {
     __first.__seg_ += __nw;
     __storage_type __m = ~__storage_type(0) >> (__bits_per_word - __n);
-    if (_Fill_Value)
+    if (_FillVal)
       *__first.__seg_ |= __m;
     else
       *__first.__seg_ &= ~__m;
@@ -1007,7 +1007,7 @@ private:
   friend class __bit_iterator<_Cp, true>;
   template <class _Dp>
   friend struct __bit_array;
-  template <bool _Fill_Value, class _Dp>
+  template <bool _FillVal, class _Dp>
   _LIBCPP_CONSTEXPR_SINCE_CXX20 friend void __fill_n(__bit_iterator<_Dp, false> __first, typename _Dp::size_type __n);
 
   template <class _Dp, bool _IC>