Use the new __has_feature(cxx_constexpr_string_builtins) for detection of the C-string intrinsics for constexpr support in std::char_traits. Thanks to Richard for the intrisic support.
llvm-svn: 293154
Cr-Mirrored-From: sso://chromium.googlesource.com/_direct/external/github.com/llvm/llvm-project
Cr-Mirrored-Commit: 3a3c09c5ddd113033b8ea64692bc5ccb3ae72b9e
diff --git a/include/__string b/include/__string
index c85b874..75608ce 100644
--- a/include/__string
+++ b/include/__string
@@ -243,7 +243,7 @@
{
if (__n == 0)
return 0;
-#ifdef _LIBCPP_BUILTIN_MEMCMP_ISCONSTEXPR
+#if __has_feature(cxx_constexpr_string_builtins)
return __builtin_memcmp(__s1, __s2, __n);
#elif _LIBCPP_STD_VER <= 14
return memcmp(__s1, __s2, __n);
@@ -265,7 +265,9 @@
{
if (__n == 0)
return NULL;
-#if _LIBCPP_STD_VER <= 14
+#if __has_feature(cxx_constexpr_string_builtins)
+ return __builtin_char_memchr(__s, to_int_type(__a), __n);
+#elif _LIBCPP_STD_VER <= 14
return (const char_type*) memchr(__s, to_int_type(__a), __n);
#else
for (; __n; --__n)
@@ -331,7 +333,7 @@
{
if (__n == 0)
return 0;
-#if __has_builtin(__builtin_wmemcmp)
+#if __has_feature(cxx_constexpr_string_builtins)
return __builtin_wmemcmp(__s1, __s2, __n);
#elif _LIBCPP_STD_VER <= 14
return wmemcmp(__s1, __s2, __n);
@@ -351,7 +353,7 @@
size_t
char_traits<wchar_t>::length(const char_type* __s) _NOEXCEPT
{
-#if __has_builtin(__builtin_wcslen)
+#if __has_feature(cxx_constexpr_string_builtins)
return __builtin_wcslen(__s);
#elif _LIBCPP_STD_VER <= 14
return wcslen(__s);
@@ -369,7 +371,7 @@
{
if (__n == 0)
return NULL;
-#if __has_builtin(__builtin_wmemchr)
+#if __has_feature(cxx_constexpr_string_builtins)
return __builtin_wmemchr(__s, __a, __n);
#elif _LIBCPP_STD_VER <= 14
return wmemchr(__s, __a, __n);