From: Jonathan Wakely <jwakely@redhat.com>
Date: Thu, 28 Mar 2024 21:29:17 +0000 (+0000)
Subject: libstdc++: Guard uses of char8_t with __cpp_char8_t [PR114519]
X-Git-Tag: basepoints/gcc-15~378
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=21aa57e73b820395b7b01843d61ef5b84cd20d02;p=thirdparty%2Fgcc.git

libstdc++: Guard uses of char8_t with __cpp_char8_t [PR114519]

libstdc++-v3/ChangeLog:

	PR libstdc++/114519
	* include/bits/unicode.h (_Utf8_view): Guard with check for
	char8_t being enabled.
	(__literal_encoding_is_unicode): Guard use of char8_t with check
	for it being enabled.
	* testsuite/std/format/functions/114519.cc: New test.
---

diff --git a/libstdc++-v3/include/bits/unicode.h b/libstdc++-v3/include/bits/unicode.h
index 51bf02e927fc..0e95c86a0b00 100644
--- a/libstdc++-v3/include/bits/unicode.h
+++ b/libstdc++-v3/include/bits/unicode.h
@@ -578,8 +578,10 @@ namespace __unicode
       constexpr bool empty() const { return ranges::empty(_M_base); }
     };
 
+#ifdef __cpp_char8_t
   template<typename _View>
     using _Utf8_view = _Utf_view<char8_t, _View>;
+#endif
   template<typename _View>
     using _Utf16_view = _Utf_view<char16_t, _View>;
   template<typename _View>
@@ -991,12 +993,14 @@ inline namespace __v15_1_0
     consteval bool
     __literal_encoding_is_unicode()
     {
-      if constexpr (is_same_v<_CharT, char8_t>)
-	return true;
-      else if constexpr (is_same_v<_CharT, char16_t>)
+      if constexpr (is_same_v<_CharT, char16_t>)
 	return true;
       else if constexpr (is_same_v<_CharT, char32_t>)
 	  return true;
+#ifdef __cpp_char8_t
+      else if constexpr (is_same_v<_CharT, char8_t>)
+	return true;
+#endif
 
       const char* __enc = "";
 
diff --git a/libstdc++-v3/testsuite/std/format/functions/114519.cc b/libstdc++-v3/testsuite/std/format/functions/114519.cc
new file mode 100644
index 000000000000..25a112a954e5
--- /dev/null
+++ b/libstdc++-v3/testsuite/std/format/functions/114519.cc
@@ -0,0 +1,3 @@
+// { dg-do compile { target c++20 } }
+// { dg-options "-fno-char8_t" }
+#include <format>