[gcc r15-2460] libstdc++: Fix src/c++20/format.cc for non-gthreads targets

[Jonathan Wakely via Libstdc++-cvs]

https://gcc.gnu.org/g:e7d88ff8aaa244f3f722fc1dc50e8dc31d5c8fde

commit r15-2460-ge7d88ff8aaa244f3f722fc1dc50e8dc31d5c8fde
Author: Jonathan Wakely <jwak...@redhat.com>
Date:   Wed Jul 31 20:27:33 2024 +0100

    libstdc++: Fix src/c++20/format.cc for non-gthreads targets
    
    libstdc++-v3/ChangeLog:
    
            * src/c++20/format.cc [!_GLIBCXX_HAS_GTHREADS] (mutex): Define
            dummy mutex type.
            * testsuite/std/time/format_localized.cc: Use loop variable
            instead of creating the same locale on every iteration.

Diff:
---
 libstdc++-v3/src/c++20/format.cc                    | 17 +++++++++++++----
 libstdc++-v3/testsuite/std/time/format_localized.cc |  2 +-
 2 files changed, 14 insertions(+), 5 deletions(-)

diff --git a/libstdc++-v3/src/c++20/format.cc b/libstdc++-v3/src/c++20/format.cc
index bcf1dd156a70..1a24fcab7f76 100644
--- a/libstdc++-v3/src/c++20/format.cc
+++ b/libstdc++-v3/src/c++20/format.cc
@@ -49,6 +49,15 @@ namespace __format
 #if defined _GLIBCXX_USE_NL_LANGINFO_L && __CHAR_BIT__ == 8
 namespace
 {
+#ifndef _GLIBCXX_HAS_GTHREADS
+// Dummy mutex
+struct mutex
+{
+  void lock() const { }
+  void unlock() const { }
+};
+#endif
+
 // A non-standard locale::facet that caches the locale's std::text_encoding
 // and an iconv descriptor for converting from that encoding to UTF-8.
 struct __encoding : locale::facet
@@ -59,7 +68,7 @@ struct __encoding : locale::facet
   __encoding(const text_encoding& enc, size_t refs = 0)
   : facet(refs), _M_enc(enc)
   {
-#if defined _GLIBCXX_HAVE_ICONV
+#ifdef _GLIBCXX_HAVE_ICONV
     using enum text_encoding::id;
     switch (_M_enc.mib())
       {
@@ -74,14 +83,14 @@ struct __encoding : locale::facet
 
   ~__encoding()
   {
-#if defined _GLIBCXX_HAVE_ICONV
+#ifdef _GLIBCXX_HAVE_ICONV
     if (_M_cd != (::iconv_t)-1)
       ::iconv_close(_M_cd);
 #endif
   }
 
   text_encoding _M_enc;
-#if defined _GLIBCXX_HAVE_ICONV
+#ifdef _GLIBCXX_HAVE_ICONV
   ::iconv_t _M_cd = (::iconv_t)-1;
   mutable mutex mx;
 #endif
@@ -93,7 +102,7 @@ struct __encoding : locale::facet
     if (input.empty()) [[unlikely]]
       return codecvt_base::noconv;
 
-#if defined _GLIBCXX_HAVE_ICONV
+#ifdef _GLIBCXX_HAVE_ICONV
     if (_M_cd == (::iconv_t)-1)
       return codecvt_base::error;
 
diff --git a/libstdc++-v3/testsuite/std/time/format_localized.cc 
b/libstdc++-v3/testsuite/std/time/format_localized.cc
index 64a1582b945e..393d0d200e45 100644
--- a/libstdc++-v3/testsuite/std/time/format_localized.cc
+++ b/libstdc++-v3/testsuite/std/time/format_localized.cc
@@ -75,7 +75,7 @@ test_en()
 
   for (auto l : {ISO_8859(1,en_US), ISO_8859(15,en_US), "en_US.UTF-8", "C"})
     {
-      std::locale loc(ISO_8859(1,en_US));
+      std::locale loc(l);
       auto s = std::format(loc, "{:L%b %B %a %A}", sys_days(2024y/July/30));
       VERIFY( s == "Jul July Tue Tuesday" );
     }