[libcxx-commits] [libcxx] [libc++] Fix acceptance of convertible-to-{float, double, long double} in std::isnan() and std::isinf() (PR #98952)

[Robin Caloudis via libcxx-commits]

https://github.com/robincaloudis created https://github.com/llvm/llvm-project/pull/98952

None

>From 0f97ac1a6bbc4736c369e90e3a1195c838dcacfb Mon Sep 17 00:00:00 2001
From: Robin Caloudis <robin.caloudis at gmx.de>
Date: Mon, 15 Jul 2024 22:04:22 +0200
Subject: [PATCH 1/4] Test convertibles in std::isinf()

---
 .../test/std/numerics/c.math/isinf.pass.cpp   | 21 +++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/libcxx/test/std/numerics/c.math/isinf.pass.cpp b/libcxx/test/std/numerics/c.math/isinf.pass.cpp
index e935b53187fe6..99aab191c4977 100644
--- a/libcxx/test/std/numerics/c.math/isinf.pass.cpp
+++ b/libcxx/test/std/numerics/c.math/isinf.pass.cpp
@@ -62,9 +62,30 @@ struct TestInt {
   }
 };
 
+struct ConvertibleFloat {
+  int value;
+  ConvertibleFloat(int v) : value(v) {}
+  operator float() const { return static_cast<float>(value); }
+};
+
+struct ConvertibleDouble {
+  int value;
+  ConvertibleDouble(int v) : value(v) {}
+  operator double() const { return static_cast<double>(value); }
+};
+
+struct ConvertibleLongDouble {
+  int value;
+  ConvertibleLongDouble(int v) : value(v) {}
+  operator long double() const { return static_cast<long double>(value); }
+};
+
 int main(int, char**) {
   types::for_each(types::floating_point_types(), TestFloat());
   types::for_each(types::integral_types(), TestInt());
+  assert(!std::isinf(ConvertibleFloat(0)));
+  assert(!std::isinf(ConvertibleDouble(0)));
+  assert(!std::isinf(ConvertibleLongDouble(0)));
 
   return 0;
 }

>From 41b2677b4fd8e7ba9ad7e9dc0d0118b6353867d3 Mon Sep 17 00:00:00 2001
From: Robin Caloudis <robin.caloudis at gmx.de>
Date: Mon, 15 Jul 2024 22:05:02 +0200
Subject: [PATCH 2/4] Remove preprocessor directive

---
 libcxx/include/__math/traits.h | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/libcxx/include/__math/traits.h b/libcxx/include/__math/traits.h
index a448266797557..fc713b1021be2 100644
--- a/libcxx/include/__math/traits.h
+++ b/libcxx/include/__math/traits.h
@@ -67,20 +67,17 @@ _LIBCPP_NODISCARD _LIBCPP_CONSTEXPR_SINCE_CXX23 _LIBCPP_HIDE_FROM_ABI bool isinf
   return false;
 }
 
-#ifdef _LIBCPP_PREFERRED_OVERLOAD
 _LIBCPP_NODISCARD inline _LIBCPP_CONSTEXPR_SINCE_CXX23 _LIBCPP_HIDE_FROM_ABI bool isinf(float __x) _NOEXCEPT {
   return __builtin_isinf(__x);
 }
 
-_LIBCPP_NODISCARD inline _LIBCPP_CONSTEXPR_SINCE_CXX23 _LIBCPP_HIDE_FROM_ABI _LIBCPP_PREFERRED_OVERLOAD bool
-isinf(double __x) _NOEXCEPT {
+_LIBCPP_NODISCARD inline _LIBCPP_CONSTEXPR_SINCE_CXX23 _LIBCPP_HIDE_FROM_ABI bool isinf(double __x) _NOEXCEPT {
   return __builtin_isinf(__x);
 }
 
 _LIBCPP_NODISCARD inline _LIBCPP_CONSTEXPR_SINCE_CXX23 _LIBCPP_HIDE_FROM_ABI bool isinf(long double __x) _NOEXCEPT {
   return __builtin_isinf(__x);
 }
-#endif
 
 // isnan
 

>From 4edaeb508132a38aaac2484facca630fa36fbd55 Mon Sep 17 00:00:00 2001
From: Robin Caloudis <robin.caloudis at gmx.de>
Date: Mon, 15 Jul 2024 22:05:20 +0200
Subject: [PATCH 3/4] Test convertibles in std::isnan()

---
 .../test/std/numerics/c.math/isnan.pass.cpp   | 21 +++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/libcxx/test/std/numerics/c.math/isnan.pass.cpp b/libcxx/test/std/numerics/c.math/isnan.pass.cpp
index fffb124645862..374aa08a600d6 100644
--- a/libcxx/test/std/numerics/c.math/isnan.pass.cpp
+++ b/libcxx/test/std/numerics/c.math/isnan.pass.cpp
@@ -62,9 +62,30 @@ struct TestInt {
   }
 };
 
+struct ConvertibleFloat {
+  int value;
+  ConvertibleFloat(int v) : value(v) {}
+  operator float() const { return static_cast<float>(value); }
+};
+
+struct ConvertibleDouble {
+  int value;
+  ConvertibleDouble(int v) : value(v) {}
+  operator double() const { return static_cast<double>(value); }
+};
+
+struct ConvertibleLongDouble {
+  int value;
+  ConvertibleLongDouble(int v) : value(v) {}
+  operator long double() const { return static_cast<long double>(value); }
+};
+
 int main(int, char**) {
   types::for_each(types::floating_point_types(), TestFloat());
   types::for_each(types::integral_types(), TestInt());
+  assert(!std::isnan(ConvertibleFloat(0)));
+  assert(!std::isnan(ConvertibleDouble(0)));
+  assert(!std::isnan(ConvertibleLongDouble(0)));
 
   return 0;
 }

>From f759c17c876f1b115b754aef3d52a703b6516b1d Mon Sep 17 00:00:00 2001
From: Robin Caloudis <robin.caloudis at gmx.de>
Date: Mon, 15 Jul 2024 22:05:40 +0200
Subject: [PATCH 4/4] Remove preprocessor directive for std::isnan()

---
 libcxx/include/__math/traits.h | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/libcxx/include/__math/traits.h b/libcxx/include/__math/traits.h
index fc713b1021be2..d58c5c5637967 100644
--- a/libcxx/include/__math/traits.h
+++ b/libcxx/include/__math/traits.h
@@ -91,20 +91,17 @@ _LIBCPP_NODISCARD _LIBCPP_CONSTEXPR_SINCE_CXX23 _LIBCPP_HIDE_FROM_ABI bool isnan
   return false;
 }
 
-#ifdef _LIBCPP_PREFERRED_OVERLOAD
 _LIBCPP_NODISCARD inline _LIBCPP_CONSTEXPR_SINCE_CXX23 _LIBCPP_HIDE_FROM_ABI bool isnan(float __x) _NOEXCEPT {
   return __builtin_isnan(__x);
 }
 
-_LIBCPP_NODISCARD inline _LIBCPP_CONSTEXPR_SINCE_CXX23 _LIBCPP_HIDE_FROM_ABI _LIBCPP_PREFERRED_OVERLOAD bool
-isnan(double __x) _NOEXCEPT {
+_LIBCPP_NODISCARD inline _LIBCPP_CONSTEXPR_SINCE_CXX23 _LIBCPP_HIDE_FROM_ABI bool isnan(double __x) _NOEXCEPT {
   return __builtin_isnan(__x);
 }
 
 _LIBCPP_NODISCARD inline _LIBCPP_CONSTEXPR_SINCE_CXX23 _LIBCPP_HIDE_FROM_ABI bool isnan(long double __x) _NOEXCEPT {
   return __builtin_isnan(__x);
 }
-#endif
 
 // isnormal