[libcxx][modules] protects users from relying on detail headers

libc++ has started splicing standard library headers into much more
fine-grained content for maintainability. It's very likely that outdated
and naive tooling (some of which is outside of LLVM's scope) will
suggest users include things such as <__ranges/access.h> instead of
<ranges>, and Hyrum's law suggests that users will eventually begin to
rely on this without the help of tooling. As such, this commit
intends to protect users from themselves, by making it a hard error for
anyone outside of the standard library to include libc++ detail headers.

Differential Revision: https://reviews.llvm.org/D106124

102 files changed, 102 insertions, 0 deletions

diff --git a/libcxx/include/__algorithm/adjacent_find.h b/libcxx/include/__algorithm/adjacent_find.h
index 83d8c26..e892ff4 100644
--- a/libcxx/include/__algorithm/adjacent_find.h
+++ b/libcxx/include/__algorithm/adjacent_find.h
@@ -16,6 +16,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/all_of.h b/libcxx/include/__algorithm/all_of.h
index 3af32a5..7b4a52c 100644
--- a/libcxx/include/__algorithm/all_of.h
+++ b/libcxx/include/__algorithm/all_of.h
@@ -14,6 +14,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/any_of.h b/libcxx/include/__algorithm/any_of.h
index 6fe6a0b..193f9bd 100644
--- a/libcxx/include/__algorithm/any_of.h
+++ b/libcxx/include/__algorithm/any_of.h
@@ -14,6 +14,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/binary_search.h b/libcxx/include/__algorithm/binary_search.h
index 15a17e1..60f91f2 100644
--- a/libcxx/include/__algorithm/binary_search.h
+++ b/libcxx/include/__algorithm/binary_search.h
@@ -17,6 +17,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/clamp.h b/libcxx/include/__algorithm/clamp.h
index b3762b8..79eab53 100644
--- a/libcxx/include/__algorithm/clamp.h
+++ b/libcxx/include/__algorithm/clamp.h
@@ -15,6 +15,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/comp.h b/libcxx/include/__algorithm/comp.h
index 62c06ae5..beb2b68 100644
--- a/libcxx/include/__algorithm/comp.h
+++ b/libcxx/include/__algorithm/comp.h
@@ -13,6 +13,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/comp_ref_type.h b/libcxx/include/__algorithm/comp_ref_type.h
index ed0ed59..70993d1 100644
--- a/libcxx/include/__algorithm/comp_ref_type.h
+++ b/libcxx/include/__algorithm/comp_ref_type.h
@@ -16,6 +16,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/copy.h b/libcxx/include/__algorithm/copy.h
index b4045cd..7c0ccb7 100644
--- a/libcxx/include/__algorithm/copy.h
+++ b/libcxx/include/__algorithm/copy.h
@@ -17,6 +17,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/copy_backward.h b/libcxx/include/__algorithm/copy_backward.h
index 9754f0c..cd21620 100644
--- a/libcxx/include/__algorithm/copy_backward.h
+++ b/libcxx/include/__algorithm/copy_backward.h
@@ -17,6 +17,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/copy_if.h b/libcxx/include/__algorithm/copy_if.h
index 9c3cd29..8960ce2 100644
--- a/libcxx/include/__algorithm/copy_if.h
+++ b/libcxx/include/__algorithm/copy_if.h
@@ -13,6 +13,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/copy_n.h b/libcxx/include/__algorithm/copy_n.h
index 8b915af..93bcea6 100644
--- a/libcxx/include/__algorithm/copy_n.h
+++ b/libcxx/include/__algorithm/copy_n.h
@@ -16,6 +16,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/count.h b/libcxx/include/__algorithm/count.h
index e18128c..e29a84b 100644
--- a/libcxx/include/__algorithm/count.h
+++ b/libcxx/include/__algorithm/count.h
@@ -15,6 +15,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/count_if.h b/libcxx/include/__algorithm/count_if.h
index 1ec2d83..b6432e9 100644
--- a/libcxx/include/__algorithm/count_if.h
+++ b/libcxx/include/__algorithm/count_if.h
@@ -15,6 +15,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/equal.h b/libcxx/include/__algorithm/equal.h
index ca1bc6b..bfd3bf1 100644
--- a/libcxx/include/__algorithm/equal.h
+++ b/libcxx/include/__algorithm/equal.h
@@ -17,6 +17,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/equal_range.h b/libcxx/include/__algorithm/equal_range.h
index 37a2c29..f4654a0 100644
--- a/libcxx/include/__algorithm/equal_range.h
+++ b/libcxx/include/__algorithm/equal_range.h
@@ -19,6 +19,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/fill.h b/libcxx/include/__algorithm/fill.h
index be5b474..ecbdc50 100644
--- a/libcxx/include/__algorithm/fill.h
+++ b/libcxx/include/__algorithm/fill.h
@@ -16,6 +16,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/fill_n.h b/libcxx/include/__algorithm/fill_n.h
index 590c8f3..3a0aca7 100644
--- a/libcxx/include/__algorithm/fill_n.h
+++ b/libcxx/include/__algorithm/fill_n.h
@@ -15,6 +15,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/find.h b/libcxx/include/__algorithm/find.h
index 641b85e..b9ed3c8 100644
--- a/libcxx/include/__algorithm/find.h
+++ b/libcxx/include/__algorithm/find.h
@@ -14,6 +14,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/find_end.h b/libcxx/include/__algorithm/find_end.h
index 0220c09..294f09e 100644
--- a/libcxx/include/__algorithm/find_end.h
+++ b/libcxx/include/__algorithm/find_end.h
@@ -16,6 +16,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/find_first_of.h b/libcxx/include/__algorithm/find_first_of.h
index b968329..1d3f0e9 100644
--- a/libcxx/include/__algorithm/find_first_of.h
+++ b/libcxx/include/__algorithm/find_first_of.h
@@ -16,6 +16,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/find_if.h b/libcxx/include/__algorithm/find_if.h
index aa98171..8fc59b5 100644
--- a/libcxx/include/__algorithm/find_if.h
+++ b/libcxx/include/__algorithm/find_if.h
@@ -14,6 +14,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/find_if_not.h b/libcxx/include/__algorithm/find_if_not.h
index 61ddab0..58fc6c3 100644
--- a/libcxx/include/__algorithm/find_if_not.h
+++ b/libcxx/include/__algorithm/find_if_not.h
@@ -14,6 +14,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/for_each.h b/libcxx/include/__algorithm/for_each.h
index bfbd37c..4d869ea 100644
--- a/libcxx/include/__algorithm/for_each.h
+++ b/libcxx/include/__algorithm/for_each.h
@@ -14,6 +14,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/for_each_n.h b/libcxx/include/__algorithm/for_each_n.h
index 2552b40..75245c3 100644
--- a/libcxx/include/__algorithm/for_each_n.h
+++ b/libcxx/include/__algorithm/for_each_n.h
@@ -15,6 +15,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/generate.h b/libcxx/include/__algorithm/generate.h
index dacbd8c..0b49f36 100644
--- a/libcxx/include/__algorithm/generate.h
+++ b/libcxx/include/__algorithm/generate.h
@@ -13,6 +13,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/generate_n.h b/libcxx/include/__algorithm/generate_n.h
index 2650e9e..0184c1f 100644
--- a/libcxx/include/__algorithm/generate_n.h
+++ b/libcxx/include/__algorithm/generate_n.h
@@ -14,6 +14,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/half_positive.h b/libcxx/include/__algorithm/half_positive.h
index 7666ef1..a3d7e18 100644
--- a/libcxx/include/__algorithm/half_positive.h
+++ b/libcxx/include/__algorithm/half_positive.h
@@ -14,6 +14,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/in_found_result.h b/libcxx/include/__algorithm/in_found_result.h
index 08ebf2f..9cbcd31 100644
--- a/libcxx/include/__algorithm/in_found_result.h
+++ b/libcxx/include/__algorithm/in_found_result.h
@@ -16,6 +16,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 #if !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
diff --git a/libcxx/include/__algorithm/in_fun_result.h b/libcxx/include/__algorithm/in_fun_result.h
index d5186e1..d971bc3 100644
--- a/libcxx/include/__algorithm/in_fun_result.h
+++ b/libcxx/include/__algorithm/in_fun_result.h
@@ -16,6 +16,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/in_in_out_result.h b/libcxx/include/__algorithm/in_in_out_result.h
index f7cb698..5b17226 100644
--- a/libcxx/include/__algorithm/in_in_out_result.h
+++ b/libcxx/include/__algorithm/in_in_out_result.h
@@ -16,6 +16,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/in_in_result.h b/libcxx/include/__algorithm/in_in_result.h
index 1590921..0de12db 100644
--- a/libcxx/include/__algorithm/in_in_result.h
+++ b/libcxx/include/__algorithm/in_in_result.h
@@ -16,6 +16,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/in_out_out_result.h b/libcxx/include/__algorithm/in_out_out_result.h
index 9788fbf..d429d4f 100644
--- a/libcxx/include/__algorithm/in_out_out_result.h
+++ b/libcxx/include/__algorithm/in_out_out_result.h
@@ -16,6 +16,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/in_out_result.h b/libcxx/include/__algorithm/in_out_result.h
index fd394a3..6edd15d 100644
--- a/libcxx/include/__algorithm/in_out_result.h
+++ b/libcxx/include/__algorithm/in_out_result.h
@@ -16,6 +16,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/includes.h b/libcxx/include/__algorithm/includes.h
index 4c87e8d..ec7d831 100644
--- a/libcxx/include/__algorithm/includes.h
+++ b/libcxx/include/__algorithm/includes.h
@@ -16,6 +16,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/inplace_merge.h b/libcxx/include/__algorithm/inplace_merge.h
index 90ca152..d22c26d 100644
--- a/libcxx/include/__algorithm/inplace_merge.h
+++ b/libcxx/include/__algorithm/inplace_merge.h
@@ -23,6 +23,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 _LIBCPP_PUSH_MACROS
diff --git a/libcxx/include/__algorithm/is_heap.h b/libcxx/include/__algorithm/is_heap.h
index fe44e63..cf57ef1 100644
--- a/libcxx/include/__algorithm/is_heap.h
+++ b/libcxx/include/__algorithm/is_heap.h
@@ -17,6 +17,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/is_heap_until.h b/libcxx/include/__algorithm/is_heap_until.h
index 39f313e..f39cf9d 100644
--- a/libcxx/include/__algorithm/is_heap_until.h
+++ b/libcxx/include/__algorithm/is_heap_until.h
@@ -16,6 +16,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/is_partitioned.h b/libcxx/include/__algorithm/is_partitioned.h
index b4f421cf..849fdab 100644
--- a/libcxx/include/__algorithm/is_partitioned.h
+++ b/libcxx/include/__algorithm/is_partitioned.h
@@ -13,6 +13,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/is_permutation.h b/libcxx/include/__algorithm/is_permutation.h
index cdd7420..2a58dcf 100644
--- a/libcxx/include/__algorithm/is_permutation.h
+++ b/libcxx/include/__algorithm/is_permutation.h
@@ -18,6 +18,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/is_sorted.h b/libcxx/include/__algorithm/is_sorted.h
index 56de95b..b4bc21b 100644
--- a/libcxx/include/__algorithm/is_sorted.h
+++ b/libcxx/include/__algorithm/is_sorted.h
@@ -17,6 +17,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/is_sorted_until.h b/libcxx/include/__algorithm/is_sorted_until.h
index 338d285..c920073 100644
--- a/libcxx/include/__algorithm/is_sorted_until.h
+++ b/libcxx/include/__algorithm/is_sorted_until.h
@@ -16,6 +16,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/iter_swap.h b/libcxx/include/__algorithm/iter_swap.h
index 038859e..8963325 100644
--- a/libcxx/include/__algorithm/iter_swap.h
+++ b/libcxx/include/__algorithm/iter_swap.h
@@ -15,6 +15,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/lexicographical_compare.h b/libcxx/include/__algorithm/lexicographical_compare.h
index 30ddf24..26ae99d 100644
--- a/libcxx/include/__algorithm/lexicographical_compare.h
+++ b/libcxx/include/__algorithm/lexicographical_compare.h
@@ -16,6 +16,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/lower_bound.h b/libcxx/include/__algorithm/lower_bound.h
index 26b64ec..6bac873 100644
--- a/libcxx/include/__algorithm/lower_bound.h
+++ b/libcxx/include/__algorithm/lower_bound.h
@@ -16,6 +16,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/make_heap.h b/libcxx/include/__algorithm/make_heap.h
index acac0aa..7e1b9a2 100644
--- a/libcxx/include/__algorithm/make_heap.h
+++ b/libcxx/include/__algorithm/make_heap.h
@@ -17,6 +17,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/max.h b/libcxx/include/__algorithm/max.h
index 345b235..f41a29c 100644
--- a/libcxx/include/__algorithm/max.h
+++ b/libcxx/include/__algorithm/max.h
@@ -17,6 +17,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 _LIBCPP_PUSH_MACROS
diff --git a/libcxx/include/__algorithm/max_element.h b/libcxx/include/__algorithm/max_element.h
index 795ec8e..ce1dfae 100644
--- a/libcxx/include/__algorithm/max_element.h
+++ b/libcxx/include/__algorithm/max_element.h
@@ -16,6 +16,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/merge.h b/libcxx/include/__algorithm/merge.h
index 48360ed..82855fa 100644
--- a/libcxx/include/__algorithm/merge.h
+++ b/libcxx/include/__algorithm/merge.h
@@ -17,6 +17,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/min.h b/libcxx/include/__algorithm/min.h
index 3d8c73d..7a092fe 100644
--- a/libcxx/include/__algorithm/min.h
+++ b/libcxx/include/__algorithm/min.h
@@ -17,6 +17,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 _LIBCPP_PUSH_MACROS
diff --git a/libcxx/include/__algorithm/min_element.h b/libcxx/include/__algorithm/min_element.h
index 129833d..b8da52b 100644
--- a/libcxx/include/__algorithm/min_element.h
+++ b/libcxx/include/__algorithm/min_element.h
@@ -16,6 +16,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/min_max_result.h b/libcxx/include/__algorithm/min_max_result.h
index 1d56a74..9d0226a 100644
--- a/libcxx/include/__algorithm/min_max_result.h
+++ b/libcxx/include/__algorithm/min_max_result.h
@@ -16,6 +16,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 _LIBCPP_PUSH_MACROS
diff --git a/libcxx/include/__algorithm/minmax.h b/libcxx/include/__algorithm/minmax.h
index 30a1194..fddfcc6 100644
--- a/libcxx/include/__algorithm/minmax.h
+++ b/libcxx/include/__algorithm/minmax.h
@@ -16,6 +16,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/minmax_element.h b/libcxx/include/__algorithm/minmax_element.h
index 80afbdf..38e280d9 100644
--- a/libcxx/include/__algorithm/minmax_element.h
+++ b/libcxx/include/__algorithm/minmax_element.h
@@ -16,6 +16,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/mismatch.h b/libcxx/include/__algorithm/mismatch.h
index f2011fa..d919e14 100644
--- a/libcxx/include/__algorithm/mismatch.h
+++ b/libcxx/include/__algorithm/mismatch.h
@@ -17,6 +17,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/move.h b/libcxx/include/__algorithm/move.h
index 72bf3d7..7769225 100644
--- a/libcxx/include/__algorithm/move.h
+++ b/libcxx/include/__algorithm/move.h
@@ -17,6 +17,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/move_backward.h b/libcxx/include/__algorithm/move_backward.h
index a56f6b8..38d361d 100644
--- a/libcxx/include/__algorithm/move_backward.h
+++ b/libcxx/include/__algorithm/move_backward.h
@@ -17,6 +17,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/next_permutation.h b/libcxx/include/__algorithm/next_permutation.h
index 05e56f4..1ea0b0d 100644
--- a/libcxx/include/__algorithm/next_permutation.h
+++ b/libcxx/include/__algorithm/next_permutation.h
@@ -18,6 +18,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/none_of.h b/libcxx/include/__algorithm/none_of.h
index b34b1e00..d9dbec0 100644
--- a/libcxx/include/__algorithm/none_of.h
+++ b/libcxx/include/__algorithm/none_of.h
@@ -14,6 +14,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/nth_element.h b/libcxx/include/__algorithm/nth_element.h
index 0f9f66d..fb754fb 100644
--- a/libcxx/include/__algorithm/nth_element.h
+++ b/libcxx/include/__algorithm/nth_element.h
@@ -22,6 +22,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/partial_sort.h b/libcxx/include/__algorithm/partial_sort.h
index 8adf5b2f..9714e4f 100644
--- a/libcxx/include/__algorithm/partial_sort.h
+++ b/libcxx/include/__algorithm/partial_sort.h
@@ -24,6 +24,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/partial_sort_copy.h b/libcxx/include/__algorithm/partial_sort_copy.h
index 7ed1e53..5a11963 100644
--- a/libcxx/include/__algorithm/partial_sort_copy.h
+++ b/libcxx/include/__algorithm/partial_sort_copy.h
@@ -19,6 +19,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/partition.h b/libcxx/include/__algorithm/partition.h
index 73d9483..d2ed4b4 100644
--- a/libcxx/include/__algorithm/partition.h
+++ b/libcxx/include/__algorithm/partition.h
@@ -15,6 +15,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/partition_copy.h b/libcxx/include/__algorithm/partition_copy.h
index cacde0b..a53916e 100644
--- a/libcxx/include/__algorithm/partition_copy.h
+++ b/libcxx/include/__algorithm/partition_copy.h
@@ -15,6 +15,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/partition_point.h b/libcxx/include/__algorithm/partition_point.h
index c2fa841..24fd5d8 100644
--- a/libcxx/include/__algorithm/partition_point.h
+++ b/libcxx/include/__algorithm/partition_point.h
@@ -15,6 +15,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/pop_heap.h b/libcxx/include/__algorithm/pop_heap.h
index 2a69f6e..6680369 100644
--- a/libcxx/include/__algorithm/pop_heap.h
+++ b/libcxx/include/__algorithm/pop_heap.h
@@ -18,6 +18,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/prev_permutation.h b/libcxx/include/__algorithm/prev_permutation.h
index 9dbc1da..2f127ea 100644
--- a/libcxx/include/__algorithm/prev_permutation.h
+++ b/libcxx/include/__algorithm/prev_permutation.h
@@ -18,6 +18,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/push_heap.h b/libcxx/include/__algorithm/push_heap.h
index 66973e0..8ff6df4 100644
--- a/libcxx/include/__algorithm/push_heap.h
+++ b/libcxx/include/__algorithm/push_heap.h
@@ -17,6 +17,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/ranges_min_element.h b/libcxx/include/__algorithm/ranges_min_element.h
index 82aaeea..218cfce 100644
--- a/libcxx/include/__algorithm/ranges_min_element.h
+++ b/libcxx/include/__algorithm/ranges_min_element.h
@@ -22,6 +22,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 #if !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
diff --git a/libcxx/include/__algorithm/ranges_swap_ranges.h b/libcxx/include/__algorithm/ranges_swap_ranges.h
index 59a875a..b05bff2e 100644
--- a/libcxx/include/__algorithm/ranges_swap_ranges.h
+++ b/libcxx/include/__algorithm/ranges_swap_ranges.h
@@ -20,6 +20,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 #ifndef _LIBCPP_HAS_NO_CONCEPTS
diff --git a/libcxx/include/__algorithm/remove.h b/libcxx/include/__algorithm/remove.h
index c00f96f..88bf9b4 100644
--- a/libcxx/include/__algorithm/remove.h
+++ b/libcxx/include/__algorithm/remove.h
@@ -16,6 +16,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/remove_copy.h b/libcxx/include/__algorithm/remove_copy.h
index a29a385..411723f 100644
--- a/libcxx/include/__algorithm/remove_copy.h
+++ b/libcxx/include/__algorithm/remove_copy.h
@@ -13,6 +13,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/remove_copy_if.h b/libcxx/include/__algorithm/remove_copy_if.h
index 36ddba4..0dbe6fd 100644
--- a/libcxx/include/__algorithm/remove_copy_if.h
+++ b/libcxx/include/__algorithm/remove_copy_if.h
@@ -13,6 +13,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/remove_if.h b/libcxx/include/__algorithm/remove_if.h
index 0ae1314..5974643 100644
--- a/libcxx/include/__algorithm/remove_if.h
+++ b/libcxx/include/__algorithm/remove_if.h
@@ -15,6 +15,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/replace.h b/libcxx/include/__algorithm/replace.h
index d0ae8f6..3454403 100644
--- a/libcxx/include/__algorithm/replace.h
+++ b/libcxx/include/__algorithm/replace.h
@@ -13,6 +13,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/replace_copy.h b/libcxx/include/__algorithm/replace_copy.h
index 7c8a5a0..f260c81 100644
--- a/libcxx/include/__algorithm/replace_copy.h
+++ b/libcxx/include/__algorithm/replace_copy.h
@@ -13,6 +13,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/replace_copy_if.h b/libcxx/include/__algorithm/replace_copy_if.h
index 9d8a68f..2dc6f6b 100644
--- a/libcxx/include/__algorithm/replace_copy_if.h
+++ b/libcxx/include/__algorithm/replace_copy_if.h
@@ -13,6 +13,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/replace_if.h b/libcxx/include/__algorithm/replace_if.h
index 37c719a..c5a06f8 100644
--- a/libcxx/include/__algorithm/replace_if.h
+++ b/libcxx/include/__algorithm/replace_if.h
@@ -13,6 +13,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/reverse.h b/libcxx/include/__algorithm/reverse.h
index 0202cd7..1bde1b0 100644
--- a/libcxx/include/__algorithm/reverse.h
+++ b/libcxx/include/__algorithm/reverse.h
@@ -15,6 +15,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/reverse_copy.h b/libcxx/include/__algorithm/reverse_copy.h
index 1583907..9db7379 100644
--- a/libcxx/include/__algorithm/reverse_copy.h
+++ b/libcxx/include/__algorithm/reverse_copy.h
@@ -13,6 +13,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/rotate.h b/libcxx/include/__algorithm/rotate.h
index 344c2f8..61e5cf1 100644
--- a/libcxx/include/__algorithm/rotate.h
+++ b/libcxx/include/__algorithm/rotate.h
@@ -21,6 +21,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/rotate_copy.h b/libcxx/include/__algorithm/rotate_copy.h
index ab569ef..7dc29dc 100644
--- a/libcxx/include/__algorithm/rotate_copy.h
+++ b/libcxx/include/__algorithm/rotate_copy.h
@@ -14,6 +14,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/sample.h b/libcxx/include/__algorithm/sample.h
index 5234961..e8b9ebf 100644
--- a/libcxx/include/__algorithm/sample.h
+++ b/libcxx/include/__algorithm/sample.h
@@ -17,6 +17,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 _LIBCPP_PUSH_MACROS
diff --git a/libcxx/include/__algorithm/search.h b/libcxx/include/__algorithm/search.h
index d89ec2b..6d1d77f 100644
--- a/libcxx/include/__algorithm/search.h
+++ b/libcxx/include/__algorithm/search.h
@@ -17,6 +17,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/search_n.h b/libcxx/include/__algorithm/search_n.h
index 4c083de6..5e563b5 100644
--- a/libcxx/include/__algorithm/search_n.h
+++ b/libcxx/include/__algorithm/search_n.h
@@ -17,6 +17,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/set_difference.h b/libcxx/include/__algorithm/set_difference.h
index 5e2dca2..23eae01 100644
--- a/libcxx/include/__algorithm/set_difference.h
+++ b/libcxx/include/__algorithm/set_difference.h
@@ -17,6 +17,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/set_intersection.h b/libcxx/include/__algorithm/set_intersection.h
index c4163fc..563ee66 100644
--- a/libcxx/include/__algorithm/set_intersection.h
+++ b/libcxx/include/__algorithm/set_intersection.h
@@ -16,6 +16,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/set_symmetric_difference.h b/libcxx/include/__algorithm/set_symmetric_difference.h
index 2dbfb35..1e0d325 100644
--- a/libcxx/include/__algorithm/set_symmetric_difference.h
+++ b/libcxx/include/__algorithm/set_symmetric_difference.h
@@ -17,6 +17,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/set_union.h b/libcxx/include/__algorithm/set_union.h
index 0ec6b09..78ee9e2 100644
--- a/libcxx/include/__algorithm/set_union.h
+++ b/libcxx/include/__algorithm/set_union.h
@@ -17,6 +17,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/shift_left.h b/libcxx/include/__algorithm/shift_left.h
index 33f06d57..51710094 100644
--- a/libcxx/include/__algorithm/shift_left.h
+++ b/libcxx/include/__algorithm/shift_left.h
@@ -16,6 +16,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/shift_right.h b/libcxx/include/__algorithm/shift_right.h
index 14bc761..65d52d3 100644
--- a/libcxx/include/__algorithm/shift_right.h
+++ b/libcxx/include/__algorithm/shift_right.h
@@ -19,6 +19,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/shuffle.h b/libcxx/include/__algorithm/shuffle.h
index 647aa3f..123a6a7 100644
--- a/libcxx/include/__algorithm/shuffle.h
+++ b/libcxx/include/__algorithm/shuffle.h
@@ -18,6 +18,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 _LIBCPP_PUSH_MACROS
diff --git a/libcxx/include/__algorithm/sift_down.h b/libcxx/include/__algorithm/sift_down.h
index b636da7..b617153 100644
--- a/libcxx/include/__algorithm/sift_down.h
+++ b/libcxx/include/__algorithm/sift_down.h
@@ -15,6 +15,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/sort.h b/libcxx/include/__algorithm/sort.h
index 27ce647..3159452 100644
--- a/libcxx/include/__algorithm/sort.h
+++ b/libcxx/include/__algorithm/sort.h
@@ -24,6 +24,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/sort_heap.h b/libcxx/include/__algorithm/sort_heap.h
index 3a63d74..9ab129a 100644
--- a/libcxx/include/__algorithm/sort_heap.h
+++ b/libcxx/include/__algorithm/sort_heap.h
@@ -18,6 +18,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/stable_partition.h b/libcxx/include/__algorithm/stable_partition.h
index 1233cc1..9e13234b 100644
--- a/libcxx/include/__algorithm/stable_partition.h
+++ b/libcxx/include/__algorithm/stable_partition.h
@@ -17,6 +17,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/stable_sort.h b/libcxx/include/__algorithm/stable_sort.h
index 33df6e8b..8658069 100644
--- a/libcxx/include/__algorithm/stable_sort.h
+++ b/libcxx/include/__algorithm/stable_sort.h
@@ -21,6 +21,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/swap_ranges.h b/libcxx/include/__algorithm/swap_ranges.h
index 0422265..4d7844d 100644
--- a/libcxx/include/__algorithm/swap_ranges.h
+++ b/libcxx/include/__algorithm/swap_ranges.h
@@ -14,6 +14,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/transform.h b/libcxx/include/__algorithm/transform.h
index f9db806..2983b71 100644
--- a/libcxx/include/__algorithm/transform.h
+++ b/libcxx/include/__algorithm/transform.h
@@ -13,6 +13,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/unique.h b/libcxx/include/__algorithm/unique.h
index 264d727..cb80ee3 100644
--- a/libcxx/include/__algorithm/unique.h
+++ b/libcxx/include/__algorithm/unique.h
@@ -17,6 +17,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/unique_copy.h b/libcxx/include/__algorithm/unique_copy.h
index f585177..4cb861d 100644
--- a/libcxx/include/__algorithm/unique_copy.h
+++ b/libcxx/include/__algorithm/unique_copy.h
@@ -15,6 +15,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/unwrap_iter.h b/libcxx/include/__algorithm/unwrap_iter.h
index e738cb2..bbadd53 100644
--- a/libcxx/include/__algorithm/unwrap_iter.h
+++ b/libcxx/include/__algorithm/unwrap_iter.h
@@ -16,6 +16,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
diff --git a/libcxx/include/__algorithm/upper_bound.h b/libcxx/include/__algorithm/upper_bound.h
index cfa021e..a4963cf 100644
--- a/libcxx/include/__algorithm/upper_bound.h
+++ b/libcxx/include/__algorithm/upper_bound.h
@@ -16,6 +16,7 @@
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
+#  pragma clang include_instead(<algorithm>)
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD