[libcxx-commits] [libcxx] [libc++] Fix uses of non-empty transparent comparator in `<map>` (PR #152624)
A. Jiang via libcxx-commits
libcxx-commits at lists.llvm.org
Fri Aug 8 00:46:14 PDT 2025
https://github.com/frederick-vs-ja updated https://github.com/llvm/llvm-project/pull/152624
>From 00e4c6d805a084c4310d4e27bb87892411bf659a Mon Sep 17 00:00:00 2001
From: "A. Jiang" <de34 at live.cn>
Date: Fri, 8 Aug 2025 10:17:33 +0800
Subject: [PATCH 1/2] [libc++] Fix uses of non-empty transparent comparator
with in `<map>`
The `__get_value()` member function was removed in LLVM 21, but the
calls in `<map>` weren't removed. This patch completes the removal and
adds regression test cases.
---
libcxx/include/map | 4 ++--
.../associative/map/map.ops/count0.pass.cpp | 4 ++++
.../associative/map/map.ops/equal_range0.pass.cpp | 7 +++++++
.../associative/map/map.ops/find0.pass.cpp | 5 +++++
.../associative/map/map.ops/lower_bound0.pass.cpp | 5 +++++
.../associative/map/map.ops/upper_bound0.pass.cpp | 5 +++++
.../multimap/multimap.ops/count0.pass.cpp | 4 ++++
.../multimap/multimap.ops/equal_range0.pass.cpp | 7 +++++++
.../multimap/multimap.ops/find0.pass.cpp | 5 +++++
.../multimap/multimap.ops/lower_bound0.pass.cpp | 5 +++++
.../multimap/multimap.ops/upper_bound0.pass.cpp | 5 +++++
libcxx/test/support/is_transparent.h | 13 +++++++++++++
12 files changed, 67 insertions(+), 2 deletions(-)
diff --git a/libcxx/include/map b/libcxx/include/map
index 6378218945ca0..9f98abef9afe0 100644
--- a/libcxx/include/map
+++ b/libcxx/include/map
@@ -691,12 +691,12 @@ public:
# if _LIBCPP_STD_VER >= 14
template <typename _K2>
_LIBCPP_HIDE_FROM_ABI bool operator()(const _K2& __x, const _CP& __y) const {
- return __comp_(__x, __y.__get_value().first);
+ return __comp_(__x, __y.first);
}
template <typename _K2>
_LIBCPP_HIDE_FROM_ABI bool operator()(const _CP& __x, const _K2& __y) const {
- return __comp_(__x.__get_value().first, __y);
+ return __comp_(__x.first, __y);
}
# endif
};
diff --git a/libcxx/test/std/containers/associative/map/map.ops/count0.pass.cpp b/libcxx/test/std/containers/associative/map/map.ops/count0.pass.cpp
index c7ba765178969..62491e2bc4438 100644
--- a/libcxx/test/std/containers/associative/map/map.ops/count0.pass.cpp
+++ b/libcxx/test/std/containers/associative/map/map.ops/count0.pass.cpp
@@ -33,6 +33,10 @@ int main(int, char**) {
typedef std::map<int, double, transparent_less_not_referenceable> M;
assert(M().count(C2Int{5}) == 0);
}
+ {
+ using M = std::map<int, double, transparent_less_nonempty>;
+ assert(M().count(C2Int{5}) == 0);
+ }
return 0;
}
diff --git a/libcxx/test/std/containers/associative/map/map.ops/equal_range0.pass.cpp b/libcxx/test/std/containers/associative/map/map.ops/equal_range0.pass.cpp
index 75724bdb387ce..57ce9339f6323 100644
--- a/libcxx/test/std/containers/associative/map/map.ops/equal_range0.pass.cpp
+++ b/libcxx/test/std/containers/associative/map/map.ops/equal_range0.pass.cpp
@@ -40,6 +40,13 @@ int main(int, char**) {
P result = example.equal_range(C2Int{5});
assert(result.first == result.second);
}
+ {
+ using M = std::map<int, double, transparent_less_nonempty>;
+ using P = std::pair<typename M::iterator, typename M::iterator>;
+ M example;
+ P result = example.equal_range(C2Int{5});
+ assert(result.first == result.second);
+ }
return 0;
}
diff --git a/libcxx/test/std/containers/associative/map/map.ops/find0.pass.cpp b/libcxx/test/std/containers/associative/map/map.ops/find0.pass.cpp
index 9825d6c5879b1..3f09d5608772d 100644
--- a/libcxx/test/std/containers/associative/map/map.ops/find0.pass.cpp
+++ b/libcxx/test/std/containers/associative/map/map.ops/find0.pass.cpp
@@ -36,6 +36,11 @@ int main(int, char**) {
M example;
assert(example.find(C2Int{5}) == example.end());
}
+ {
+ using M = std::map<int, double, transparent_less_nonempty>;
+ M example;
+ assert(example.find(C2Int{5}) == example.end());
+ }
return 0;
}
diff --git a/libcxx/test/std/containers/associative/map/map.ops/lower_bound0.pass.cpp b/libcxx/test/std/containers/associative/map/map.ops/lower_bound0.pass.cpp
index fe7fe381a86eb..308a2ed1e3af0 100644
--- a/libcxx/test/std/containers/associative/map/map.ops/lower_bound0.pass.cpp
+++ b/libcxx/test/std/containers/associative/map/map.ops/lower_bound0.pass.cpp
@@ -36,6 +36,11 @@ int main(int, char**) {
M example;
assert(example.lower_bound(C2Int{5}) == example.end());
}
+ {
+ using M = std::map<int, double, transparent_less_nonempty>;
+ M example;
+ assert(example.lower_bound(C2Int{5}) == example.end());
+ }
return 0;
}
diff --git a/libcxx/test/std/containers/associative/map/map.ops/upper_bound0.pass.cpp b/libcxx/test/std/containers/associative/map/map.ops/upper_bound0.pass.cpp
index 525aa673ea74b..332b71a84e9fb 100644
--- a/libcxx/test/std/containers/associative/map/map.ops/upper_bound0.pass.cpp
+++ b/libcxx/test/std/containers/associative/map/map.ops/upper_bound0.pass.cpp
@@ -36,6 +36,11 @@ int main(int, char**) {
M example;
assert(example.upper_bound(C2Int{5}) == example.end());
}
+ {
+ using M = std::map<int, double, transparent_less_nonempty>;
+ M example;
+ assert(example.upper_bound(C2Int{5}) == example.end());
+ }
return 0;
}
diff --git a/libcxx/test/std/containers/associative/multimap/multimap.ops/count0.pass.cpp b/libcxx/test/std/containers/associative/multimap/multimap.ops/count0.pass.cpp
index 233d1a11e1d6c..36f0ac2647ba3 100644
--- a/libcxx/test/std/containers/associative/multimap/multimap.ops/count0.pass.cpp
+++ b/libcxx/test/std/containers/associative/multimap/multimap.ops/count0.pass.cpp
@@ -33,6 +33,10 @@ int main(int, char**) {
typedef std::multimap<int, double, transparent_less_not_referenceable> M;
assert(M().count(C2Int{5}) == 0);
}
+ {
+ using M = std::multimap<int, double, transparent_less_nonempty>;
+ assert(M().count(C2Int{5}) == 0);
+ }
return 0;
}
diff --git a/libcxx/test/std/containers/associative/multimap/multimap.ops/equal_range0.pass.cpp b/libcxx/test/std/containers/associative/multimap/multimap.ops/equal_range0.pass.cpp
index 0bead6c7938db..a362c03e26385 100644
--- a/libcxx/test/std/containers/associative/multimap/multimap.ops/equal_range0.pass.cpp
+++ b/libcxx/test/std/containers/associative/multimap/multimap.ops/equal_range0.pass.cpp
@@ -40,6 +40,13 @@ int main(int, char**) {
P result = example.equal_range(C2Int{5});
assert(result.first == result.second);
}
+ {
+ using M = std::multimap<int, double, transparent_less_nonempty>;
+ using P = std::pair<typename M::iterator, typename M::iterator>;
+ M example;
+ P result = example.equal_range(C2Int{5});
+ assert(result.first == result.second);
+ }
return 0;
}
diff --git a/libcxx/test/std/containers/associative/multimap/multimap.ops/find0.pass.cpp b/libcxx/test/std/containers/associative/multimap/multimap.ops/find0.pass.cpp
index 701d4e314e7a8..ccb0900e76835 100644
--- a/libcxx/test/std/containers/associative/multimap/multimap.ops/find0.pass.cpp
+++ b/libcxx/test/std/containers/associative/multimap/multimap.ops/find0.pass.cpp
@@ -36,6 +36,11 @@ int main(int, char**) {
M example;
assert(example.find(C2Int{5}) == example.end());
}
+ {
+ using M = std::multimap<int, double, transparent_less_nonempty>;
+ M example;
+ assert(example.find(C2Int{5}) == example.end());
+ }
return 0;
}
diff --git a/libcxx/test/std/containers/associative/multimap/multimap.ops/lower_bound0.pass.cpp b/libcxx/test/std/containers/associative/multimap/multimap.ops/lower_bound0.pass.cpp
index 79f994847f131..4b4853062001f 100644
--- a/libcxx/test/std/containers/associative/multimap/multimap.ops/lower_bound0.pass.cpp
+++ b/libcxx/test/std/containers/associative/multimap/multimap.ops/lower_bound0.pass.cpp
@@ -36,6 +36,11 @@ int main(int, char**) {
M example;
assert(example.lower_bound(C2Int{5}) == example.end());
}
+ {
+ using M = std::multimap<int, double, transparent_less_nonempty>;
+ M example;
+ assert(example.lower_bound(C2Int{5}) == example.end());
+ }
return 0;
}
diff --git a/libcxx/test/std/containers/associative/multimap/multimap.ops/upper_bound0.pass.cpp b/libcxx/test/std/containers/associative/multimap/multimap.ops/upper_bound0.pass.cpp
index 62f52416b9156..f2ae94577b6c1 100644
--- a/libcxx/test/std/containers/associative/multimap/multimap.ops/upper_bound0.pass.cpp
+++ b/libcxx/test/std/containers/associative/multimap/multimap.ops/upper_bound0.pass.cpp
@@ -36,6 +36,11 @@ int main(int, char**) {
M example;
assert(example.upper_bound(C2Int{5}) == example.end());
}
+ {
+ using M = std::multimap<int, double, transparent_less_nonempty>;
+ M example;
+ assert(example.upper_bound(C2Int{5}) == example.end());
+ }
return 0;
}
diff --git a/libcxx/test/support/is_transparent.h b/libcxx/test/support/is_transparent.h
index 700c894a8b60f..350ef97f31877 100644
--- a/libcxx/test/support/is_transparent.h
+++ b/libcxx/test/support/is_transparent.h
@@ -36,6 +36,19 @@ struct transparent_less_not_referenceable
using is_transparent = void () const &; // it's a type; a weird one, but a type
};
+// Prevent regression when empty base class optimization is not suitable.
+// See https://github.com/llvm/llvm-project/issues/152543.
+struct transparent_less_nonempty {
+ template <class T, class U>
+ constexpr auto operator()(T&& t, U&& u) const //
+ noexcept(noexcept(std::forward<T>(t) < std::forward<U>(u))) //
+ -> decltype /**/ (std::forward<T>(t) < std::forward<U>(u)) {
+ return /*--------*/ std::forward<T>(t) < std::forward<U>(u);
+ }
+ struct is_transparent {
+ } pad_; // making this comparator non-empty
+};
+
struct transparent_less_no_type
{
template <class T, class U>
>From b187fdf728bcfca0cc1dbb7a26323865892affd5 Mon Sep 17 00:00:00 2001
From: "A. Jiang" <de34 at live.cn>
Date: Fri, 8 Aug 2025 15:45:59 +0800
Subject: [PATCH 2/2] Simpify `transparent_less_nonempty`
---
libcxx/test/support/is_transparent.h | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)
diff --git a/libcxx/test/support/is_transparent.h b/libcxx/test/support/is_transparent.h
index 350ef97f31877..4b2a458f574aa 100644
--- a/libcxx/test/support/is_transparent.h
+++ b/libcxx/test/support/is_transparent.h
@@ -40,10 +40,8 @@ struct transparent_less_not_referenceable
// See https://github.com/llvm/llvm-project/issues/152543.
struct transparent_less_nonempty {
template <class T, class U>
- constexpr auto operator()(T&& t, U&& u) const //
- noexcept(noexcept(std::forward<T>(t) < std::forward<U>(u))) //
- -> decltype /**/ (std::forward<T>(t) < std::forward<U>(u)) {
- return /*--------*/ std::forward<T>(t) < std::forward<U>(u);
+ constexpr bool operator()(T&& t, U&& u) const {
+ return std::forward<T>(t) < std::forward<U>(u);
}
struct is_transparent {
} pad_; // making this comparator non-empty
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