[gcc r15-4247] libstdc++: Fix some test failures with -fno-char8_t

[Jonathan Wakely via Libstdc++-cvs]

https://gcc.gnu.org/g:cb0988a659cef6324887018b9066c5f81b558832

commit r15-4247-gcb0988a659cef6324887018b9066c5f81b558832
Author: Jonathan Wakely <jwak...@redhat.com>
Date:   Wed Oct 9 14:24:19 2024 +0100

    libstdc++: Fix some test failures with -fno-char8_t
    
    libstdc++-v3/ChangeLog:
    
            * testsuite/20_util/duration/io.cc [!__cpp_lib_char8_t]: Define
            char8_t as a typedef for unsigned char.
            * testsuite/std/format/parse_ctx_neg.cc: Skip for -fno-char8_t.

Diff:
---
 libstdc++-v3/testsuite/20_util/duration/io.cc      | 10 ++++++++--
 libstdc++-v3/testsuite/std/format/parse_ctx_neg.cc |  1 +
 2 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/libstdc++-v3/testsuite/20_util/duration/io.cc 
b/libstdc++-v3/testsuite/20_util/duration/io.cc
index 383fb60afe2a..0117673dbdc0 100644
--- a/libstdc++-v3/testsuite/20_util/duration/io.cc
+++ b/libstdc++-v3/testsuite/20_util/duration/io.cc
@@ -5,6 +5,10 @@
 #include <sstream>
 #include <testsuite_hooks.h>
 
+#ifndef __cpp_lib_char8_t
+using char8_t = unsigned char; // Prevent errors if -fno-char8_t is used.
+#endif
+
 void
 test01()
 {
@@ -173,12 +177,14 @@ test_format()
 
 #if __cplusplus > 202002L
   static_assert( ! std::formattable<std::chrono::duration<wchar_t>, char> );
-  static_assert( ! std::formattable<std::chrono::duration<char8_t>, char> );
   static_assert( ! std::formattable<std::chrono::duration<char16_t>, char> );
   static_assert( ! std::formattable<std::chrono::duration<char32_t>, char> );
-  static_assert( ! std::formattable<std::chrono::duration<char8_t>, wchar_t> );
   static_assert( ! std::formattable<std::chrono::duration<char16_t>, wchar_t> 
);
   static_assert( ! std::formattable<std::chrono::duration<char32_t>, wchar_t> 
);
+#ifdef __cpp_lib_char8_t
+  static_assert( ! std::formattable<std::chrono::duration<char8_t>, char> );
+  static_assert( ! std::formattable<std::chrono::duration<char8_t>, wchar_t> );
+#endif
 #endif
 }
 
diff --git a/libstdc++-v3/testsuite/std/format/parse_ctx_neg.cc 
b/libstdc++-v3/testsuite/std/format/parse_ctx_neg.cc
index d6a4366d7d0b..f19107c886fc 100644
--- a/libstdc++-v3/testsuite/std/format/parse_ctx_neg.cc
+++ b/libstdc++-v3/testsuite/std/format/parse_ctx_neg.cc
@@ -1,4 +1,5 @@
 // { dg-do compile { target c++26 } }
+// { dg-skip-if "" { *-*-* } { "-fno-char8_t" } }
 
 #include <format>