[libc++] __uglify internal member names of iterators in bitset (llv…

…m#111127) [template.bitset.general] indicates that `bitset` shouldn't have member typedef-names `iterator` and `const_iterator`. Currently libc++'s typedef-names are causing ambiguity in name lookup, which isn't conforming. As these iterator types are themselves useful, I think we should just use __uglified member typedef-names for them. Fixes llvm#111125
demin-han · Oct 10, 2024 · 159d694 · 159d694
1 parent 1f919aa
commit 159d694
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diff --git a/libcxx/docs/ReleaseNotes/20.rst b/libcxx/docs/ReleaseNotes/20.rst
@@ -78,6 +78,10 @@ Deprecations and Removals
   supported as an extension anymore, please migrate any code that uses e.g. ``std::vector<const T>`` to be
   standards conforming.
 
+- Non-conforming member typedefs ``iterator`` and ``const_iterator`` of ``std::bitset`` are removed. Previously, they
+  were private but could cause ambiguity in name lookup. Code that expects such ambiguity will possibly not compile in
+  LLVM 20.
+
 Upcoming Deprecations and Removals
 ----------------------------------
 

diff --git a/libcxx/include/bitset b/libcxx/include/bitset
@@ -187,8 +187,8 @@ protected:
 
   typedef __bit_reference<__bitset> reference;
   typedef __bit_const_reference<__bitset> const_reference;
-  typedef __bit_iterator<__bitset, false> iterator;
-  typedef __bit_iterator<__bitset, true> const_iterator;
+  typedef __bit_iterator<__bitset, false> __iterator;
+  typedef __bit_iterator<__bitset, true> __const_iterator;
 
   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR __bitset() _NOEXCEPT;
   _LIBCPP_HIDE_FROM_ABI explicit _LIBCPP_CONSTEXPR __bitset(unsigned long long __v) _NOEXCEPT;
@@ -199,11 +199,11 @@ protected:
   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR const_reference __make_ref(size_t __pos) const _NOEXCEPT {
     return const_reference(__first_ + __pos / __bits_per_word, __storage_type(1) << __pos % __bits_per_word);
   }
-  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 iterator __make_iter(size_t __pos) _NOEXCEPT {
-    return iterator(__first_ + __pos / __bits_per_word, __pos % __bits_per_word);
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 __iterator __make_iter(size_t __pos) _NOEXCEPT {
+    return __iterator(__first_ + __pos / __bits_per_word, __pos % __bits_per_word);
   }
-  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 const_iterator __make_iter(size_t __pos) const _NOEXCEPT {
-    return const_iterator(__first_ + __pos / __bits_per_word, __pos % __bits_per_word);
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 __const_iterator __make_iter(size_t __pos) const _NOEXCEPT {
+    return __const_iterator(__first_ + __pos / __bits_per_word, __pos % __bits_per_word);
   }
 
   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 void operator&=(const __bitset& __v) _NOEXCEPT;
@@ -335,8 +335,8 @@ _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 void __bitset<_N_words, _Siz
 template <size_t _N_words, size_t _Size>
 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 unsigned long
 __bitset<_N_words, _Size>::to_ulong(false_type) const {
-  const_iterator __e = __make_iter(_Size);
-  const_iterator __i = std::find(__make_iter(sizeof(unsigned long) * CHAR_BIT), __e, true);
+  __const_iterator __e = __make_iter(_Size);
+  __const_iterator __i = std::find(__make_iter(sizeof(unsigned long) * CHAR_BIT), __e, true);
   if (__i != __e)
     __throw_overflow_error("bitset to_ulong overflow error");
 
@@ -352,8 +352,8 @@ __bitset<_N_words, _Size>::to_ulong(true_type) const {
 template <size_t _N_words, size_t _Size>
 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 unsigned long long
 __bitset<_N_words, _Size>::to_ullong(false_type) const {
-  const_iterator __e = __make_iter(_Size);
-  const_iterator __i = std::find(__make_iter(sizeof(unsigned long long) * CHAR_BIT), __e, true);
+  __const_iterator __e = __make_iter(_Size);
+  __const_iterator __i = std::find(__make_iter(sizeof(unsigned long long) * CHAR_BIT), __e, true);
   if (__i != __e)
     __throw_overflow_error("bitset to_ullong overflow error");
 
@@ -449,8 +449,8 @@ protected:
 
   typedef __bit_reference<__bitset> reference;
   typedef __bit_const_reference<__bitset> const_reference;
-  typedef __bit_iterator<__bitset, false> iterator;
-  typedef __bit_iterator<__bitset, true> const_iterator;
+  typedef __bit_iterator<__bitset, false> __iterator;
+  typedef __bit_iterator<__bitset, true> __const_iterator;
 
   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR __bitset() _NOEXCEPT;
   _LIBCPP_HIDE_FROM_ABI explicit _LIBCPP_CONSTEXPR __bitset(unsigned long long __v) _NOEXCEPT;
@@ -461,11 +461,11 @@ protected:
   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR const_reference __make_ref(size_t __pos) const _NOEXCEPT {
     return const_reference(&__first_, __storage_type(1) << __pos);
   }
-  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 iterator __make_iter(size_t __pos) _NOEXCEPT {
-    return iterator(&__first_ + __pos / __bits_per_word, __pos % __bits_per_word);
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 __iterator __make_iter(size_t __pos) _NOEXCEPT {
+    return __iterator(&__first_ + __pos / __bits_per_word, __pos % __bits_per_word);
   }
-  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 const_iterator __make_iter(size_t __pos) const _NOEXCEPT {
-    return const_iterator(&__first_ + __pos / __bits_per_word, __pos % __bits_per_word);
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 __const_iterator __make_iter(size_t __pos) const _NOEXCEPT {
+    return __const_iterator(&__first_ + __pos / __bits_per_word, __pos % __bits_per_word);
   }
 
   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 void operator&=(const __bitset& __v) _NOEXCEPT;
@@ -564,8 +564,8 @@ protected:
 
   typedef __bit_reference<__bitset> reference;
   typedef __bit_const_reference<__bitset> const_reference;
-  typedef __bit_iterator<__bitset, false> iterator;
-  typedef __bit_iterator<__bitset, true> const_iterator;
+  typedef __bit_iterator<__bitset, false> __iterator;
+  typedef __bit_iterator<__bitset, true> __const_iterator;
 
   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR __bitset() _NOEXCEPT;
   _LIBCPP_HIDE_FROM_ABI explicit _LIBCPP_CONSTEXPR __bitset(unsigned long long) _NOEXCEPT;
@@ -576,11 +576,11 @@ protected:
   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR const_reference __make_ref(size_t) const _NOEXCEPT {
     return const_reference(nullptr, 1);
   }
-  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 iterator __make_iter(size_t) _NOEXCEPT {
-    return iterator(nullptr, 0);
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 __iterator __make_iter(size_t) _NOEXCEPT {
+    return __iterator(nullptr, 0);
   }
-  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 const_iterator __make_iter(size_t) const _NOEXCEPT {
-    return const_iterator(nullptr, 0);
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 __const_iterator __make_iter(size_t) const _NOEXCEPT {
+    return __const_iterator(nullptr, 0);
   }
 
   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 void operator&=(const __bitset&) _NOEXCEPT {}

diff --git a/libcxx/test/std/utilities/template.bitset/bitset.members/nonstdmem.uglified.compile.pass.cpp b/libcxx/test/std/utilities/template.bitset/bitset.members/nonstdmem.uglified.compile.pass.cpp
@@ -0,0 +1,46 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// <bitset>
+
+// This test ensures that we don't use a non-uglified name 'iterator' and
+// 'const_iterator' in the implementation of bitset.
+//
+// See https://github.com/llvm/llvm-project/issues/111125.
+
+#include <cstddef>
+#include <bitset>
+#include <type_traits>
+
+struct my_base {
+  typedef int* iterator;
+  typedef const int* const_iterator;
+};
+
+template <std::size_t N>
+struct my_derived : my_base, std::bitset<N> {};
+
+static_assert(std::is_same<my_derived<0>::iterator, int*>::value, "");
+static_assert(std::is_same<my_derived<1>::iterator, int*>::value, "");
+static_assert(std::is_same<my_derived<8>::iterator, int*>::value, "");
+static_assert(std::is_same<my_derived<12>::iterator, int*>::value, "");
+static_assert(std::is_same<my_derived<16>::iterator, int*>::value, "");
+static_assert(std::is_same<my_derived<32>::iterator, int*>::value, "");
+static_assert(std::is_same<my_derived<48>::iterator, int*>::value, "");
+static_assert(std::is_same<my_derived<64>::iterator, int*>::value, "");
+static_assert(std::is_same<my_derived<96>::iterator, int*>::value, "");
+
+static_assert(std::is_same<my_derived<0>::const_iterator, const int*>::value, "");
+static_assert(std::is_same<my_derived<1>::const_iterator, const int*>::value, "");
+static_assert(std::is_same<my_derived<8>::const_iterator, const int*>::value, "");
+static_assert(std::is_same<my_derived<12>::const_iterator, const int*>::value, "");
+static_assert(std::is_same<my_derived<16>::const_iterator, const int*>::value, "");
+static_assert(std::is_same<my_derived<32>::const_iterator, const int*>::value, "");
+static_assert(std::is_same<my_derived<48>::const_iterator, const int*>::value, "");
+static_assert(std::is_same<my_derived<64>::const_iterator, const int*>::value, "");
+static_assert(std::is_same<my_derived<96>::const_iterator, const int*>::value, "");