[libc++][ranges] remove `__workaround_52970` #85683

xiaoyang-sde · 2024-03-18T19:38:31Z

Abstract

This pull request removes the __workaround_52970 concept. This concept is a workaround for a bug described in #52970, which causes the compiler to trigger ADL on a pointer to an incomplete type in an SFINAE context. This bug is fixed in Clang 14.

Reference

github-actions · 2024-03-18T19:38:47Z

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llvmbot · 2024-03-18T19:39:24Z

@llvm/pr-subscribers-libcxx

Author: Xiaoyang Liu (xiaoyang-sde)

Changes

Abstract

This pull request removes the __workaround_52970 concept. This concept is a workaround for a bug described in #52970, which causes the compiler to trigger ADL on a pointer to an incomplete type in an SFINAE context. This bug is fixed in Clang 14.

Reference

Full diff: https://github.com/llvm/llvm-project/pull/85683.diff

7 Files Affected:

(modified) libcxx/include/__concepts/class_or_enum.h (-5)
(modified) libcxx/include/__ranges/access.h (+2-2)
(modified) libcxx/include/__ranges/data.h (+1-1)
(modified) libcxx/include/__ranges/empty.h (+1-1)
(modified) libcxx/include/__ranges/rbegin.h (+1-1)
(modified) libcxx/include/__ranges/rend.h (+1-1)
(modified) libcxx/include/__ranges/size.h (+1-1)

diff --git a/libcxx/include/__concepts/class_or_enum.h b/libcxx/include/__concepts/class_or_enum.h
index c1b4a8c258f3a5..2739e31e14ba65 100644
--- a/libcxx/include/__concepts/class_or_enum.h
+++ b/libcxx/include/__concepts/class_or_enum.h
@@ -28,11 +28,6 @@ _LIBCPP_BEGIN_NAMESPACE_STD
 template <class _Tp>
 concept __class_or_enum = is_class_v<_Tp> || is_union_v<_Tp> || is_enum_v<_Tp>;
 
-// Work around Clang bug https://llvm.org/PR52970
-// TODO: remove this workaround once libc++ no longer has to support Clang 13 (it was fixed in Clang 14).
-template <class _Tp>
-concept __workaround_52970 = is_class_v<__remove_cvref_t<_Tp>> || is_union_v<__remove_cvref_t<_Tp>>;
-
 #endif // _LIBCPP_STD_VER >= 20
 
 _LIBCPP_END_NAMESPACE_STD
diff --git a/libcxx/include/__ranges/access.h b/libcxx/include/__ranges/access.h
index 218b3928ecdc5f..3db4f11b40f2d0 100644
--- a/libcxx/include/__ranges/access.h
+++ b/libcxx/include/__ranges/access.h
@@ -41,7 +41,7 @@ concept __can_borrow = is_lvalue_reference_v<_Tp> || enable_borrowed_range<remov
 namespace ranges {
 namespace __begin {
 template <class _Tp>
-concept __member_begin = __can_borrow<_Tp> && __workaround_52970<_Tp> && requires(_Tp&& __t) {
+concept __member_begin = __can_borrow<_Tp> && requires(_Tp&& __t) {
   { _LIBCPP_AUTO_CAST(__t.begin()) } -> input_or_output_iterator;
 };
 
@@ -103,7 +103,7 @@ using iterator_t = decltype(ranges::begin(std::declval<_Tp&>()));
 namespace ranges {
 namespace __end {
 template <class _Tp>
-concept __member_end = __can_borrow<_Tp> && __workaround_52970<_Tp> && requires(_Tp&& __t) {
+concept __member_end = __can_borrow<_Tp> && requires(_Tp&& __t) {
   typename iterator_t<_Tp>;
   { _LIBCPP_AUTO_CAST(__t.end()) } -> sentinel_for<iterator_t<_Tp>>;
 };
diff --git a/libcxx/include/__ranges/data.h b/libcxx/include/__ranges/data.h
index 18002bb52cc8ce..131f6cdad8f21c 100644
--- a/libcxx/include/__ranges/data.h
+++ b/libcxx/include/__ranges/data.h
@@ -40,7 +40,7 @@ template <class _Tp>
 concept __ptr_to_object = is_pointer_v<_Tp> && is_object_v<remove_pointer_t<_Tp>>;
 
 template <class _Tp>
-concept __member_data = __can_borrow<_Tp> && __workaround_52970<_Tp> && requires(_Tp&& __t) {
+concept __member_data = __can_borrow<_Tp> && requires(_Tp&& __t) {
   { _LIBCPP_AUTO_CAST(__t.data()) } -> __ptr_to_object;
 };
 
diff --git a/libcxx/include/__ranges/empty.h b/libcxx/include/__ranges/empty.h
index acd55dae224ce7..5c1004042aba51 100644
--- a/libcxx/include/__ranges/empty.h
+++ b/libcxx/include/__ranges/empty.h
@@ -29,7 +29,7 @@ _LIBCPP_BEGIN_NAMESPACE_STD
 namespace ranges {
 namespace __empty {
 template <class _Tp>
-concept __member_empty = __workaround_52970<_Tp> && requires(_Tp&& __t) { bool(__t.empty()); };
+concept __member_empty = requires(_Tp&& __t) { bool(__t.empty()); };
 
 template <class _Tp>
 concept __can_invoke_size = !__member_empty<_Tp> && requires(_Tp&& __t) { ranges::size(__t); };
diff --git a/libcxx/include/__ranges/rbegin.h b/libcxx/include/__ranges/rbegin.h
index 947e428f00cd52..12e739e1a2b852 100644
--- a/libcxx/include/__ranges/rbegin.h
+++ b/libcxx/include/__ranges/rbegin.h
@@ -36,7 +36,7 @@ _LIBCPP_BEGIN_NAMESPACE_STD
 namespace ranges {
 namespace __rbegin {
 template <class _Tp>
-concept __member_rbegin = __can_borrow<_Tp> && __workaround_52970<_Tp> && requires(_Tp&& __t) {
+concept __member_rbegin = __can_borrow<_Tp> && requires(_Tp&& __t) {
   { _LIBCPP_AUTO_CAST(__t.rbegin()) } -> input_or_output_iterator;
 };
 
diff --git a/libcxx/include/__ranges/rend.h b/libcxx/include/__ranges/rend.h
index 1b6be58fea24b4..5edbc4e3160c5f 100644
--- a/libcxx/include/__ranges/rend.h
+++ b/libcxx/include/__ranges/rend.h
@@ -37,7 +37,7 @@ _LIBCPP_BEGIN_NAMESPACE_STD
 namespace ranges {
 namespace __rend {
 template <class _Tp>
-concept __member_rend = __can_borrow<_Tp> && __workaround_52970<_Tp> && requires(_Tp&& __t) {
+concept __member_rend = __can_borrow<_Tp> && requires(_Tp&& __t) {
   ranges::rbegin(__t);
   { _LIBCPP_AUTO_CAST(__t.rend()) } -> sentinel_for<decltype(ranges::rbegin(__t))>;
 };
diff --git a/libcxx/include/__ranges/size.h b/libcxx/include/__ranges/size.h
index 59ca2b11ee3890..40b0c6b6aad7a3 100644
--- a/libcxx/include/__ranges/size.h
+++ b/libcxx/include/__ranges/size.h
@@ -47,7 +47,7 @@ template <class _Tp>
 concept __size_enabled = !disable_sized_range<remove_cvref_t<_Tp>>;
 
 template <class _Tp>
-concept __member_size = __size_enabled<_Tp> && __workaround_52970<_Tp> && requires(_Tp&& __t) {
+concept __member_size = __size_enabled<_Tp> && requires(_Tp&& __t) {
   { _LIBCPP_AUTO_CAST(__t.size()) } -> __integer_like;
 };

ldionne

Thank you! This LGTM with green CI.

xiaoyang-sde · 2024-03-19T21:58:35Z

Thank you! This LGTM with green CI.

Thanks for approving this PR! Could you please merge it once all CI checks have been passed? I don't have the permission to do so. (This also applies to #85004)

github-actions · 2024-03-20T08:49:47Z

@xiaoyang-sde Congratulations on having your first Pull Request (PR) merged into the LLVM Project!

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## Abstract This pull request removes the `__workaround_52970` concept. This concept is a workaround for a bug described in llvm#52970, which causes the compiler to trigger ADL on a pointer to an incomplete type in an SFINAE context. This bug is fixed in Clang 14. ## Reference - [[clang] Don't typo-fix an expression in a SFINAE context](https://reviews.llvm.org/D117603) - [[libc++] [ranges] ADL-proof the [range.access] CPOs.](https://reviews.llvm.org/D116239)

…cbbde5500 Local branch amd-gfx b31cbbd Merged main:d7e28cd82bd3141093f96f7ce2e7b36f1b115fad into amd-gfx:0b79b4caf568 Remote branch main 211eebf [libc++][ranges] remove `__workaround_52970` (llvm#85683)

Xiaoyang Liu added 2 commits March 18, 2024 12:27

[libc++] [ranges] remove '__workaround_52970'

4790b11

[libc++] [ranges] revert unexpected 'clang-format'

8d27438

xiaoyang-sde requested a review from a team as a code owner March 18, 2024 19:38

llvmbot added the libc++ libc++ C++ Standard Library. Not GNU libstdc++. Not libc++abi. label Mar 18, 2024

xiaoyang-sde changed the title ~~[libc++] [ranges] remove __workaround_52970~~ [libc++][ranges] remove __workaround_52970 Mar 19, 2024

ldionne approved these changes Mar 19, 2024

View reviewed changes

mordante merged commit 211eebf into llvm:main Mar 20, 2024

xiaoyang-sde deleted the remove_workaround_52970 branch March 20, 2024 15:07

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