[gcc r14-3839] libstdc++: Fix -Wunused-parameter warnings

[Jonathan Wakely <redi@gcc.gnu.org>]

https://gcc.gnu.org/g:390fa3a78c84d97783afda9278df70d4a4ac2471

commit r14-3839-g390fa3a78c84d97783afda9278df70d4a4ac2471
Author: Pekka Seppänen <pexu@gcc.mail.kapsi.fi>
Date:   Thu Sep 7 22:30:00 2023 +0300

    libstdc++: Fix -Wunused-parameter warnings
    
    Fix -Wunused-parameter warnings when _GLIBCXX_USE_WCHAR_T is not
    defined.
    
    libstdc++-v3/ChangeLog:
    
            * src/c++11/cow-locale_init.cc: Add [[maybe_unused]] attribute.
            * src/c++17/fs_path.cc (path::_S_convert_loc): Likewise.
            * src/filesystem/path.cc (path::_S_convert_loc): Likewise.
    
    Signed-off-by: Pekka Seppänen <pexu@gcc.mail.kapsi.fi>

Diff:
---
 libstdc++-v3/src/c++11/cow-locale_init.cc | 5 +++--
 libstdc++-v3/src/c++17/fs_path.cc         | 2 +-
 libstdc++-v3/src/filesystem/path.cc       | 2 +-
 3 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/libstdc++-v3/src/c++11/cow-locale_init.cc b/libstdc++-v3/src/c++11/cow-locale_init.cc
index 852777634272..f48561f5b12b 100644
--- a/libstdc++-v3/src/c++11/cow-locale_init.cc
+++ b/libstdc++-v3/src/c++11/cow-locale_init.cc
@@ -137,8 +137,9 @@ namespace
   }
 
   void
-  locale::_Impl::_M_init_extra(void* cloc, void* clocm,
-                               const char* __s, const char* __smon)
+  locale::_Impl::_M_init_extra(void* cloc, [[maybe_unused]] void* clocm,
+			       const char* __s,
+			       [[maybe_unused]] const char* __smon)
   {
     auto& __cloc = *static_cast<__c_locale*>(cloc);
 
diff --git a/libstdc++-v3/src/c++17/fs_path.cc b/libstdc++-v3/src/c++17/fs_path.cc
index aaea7d2725db..d65b5482e8b9 100644
--- a/libstdc++-v3/src/c++17/fs_path.cc
+++ b/libstdc++-v3/src/c++17/fs_path.cc
@@ -1947,7 +1947,7 @@ path::_M_split_cmpts()
 
 path::string_type
 path::_S_convert_loc(const char* __first, const char* __last,
-		     const std::locale& __loc)
+		     [[maybe_unused]] const std::locale& __loc)
 {
 #if _GLIBCXX_USE_WCHAR_T
   auto& __cvt = std::use_facet<codecvt<wchar_t, char, mbstate_t>>(__loc);
diff --git a/libstdc++-v3/src/filesystem/path.cc b/libstdc++-v3/src/filesystem/path.cc
index 4c218bdae497..d04ba6d465d2 100644
--- a/libstdc++-v3/src/filesystem/path.cc
+++ b/libstdc++-v3/src/filesystem/path.cc
@@ -498,7 +498,7 @@ path::_M_trim()
 
 path::string_type
 path::_S_convert_loc(const char* __first, const char* __last,
-		     const std::locale& __loc)
+		     [[maybe_unused]] const std::locale& __loc)
 {
 #if _GLIBCXX_USE_WCHAR_T
   auto& __cvt = std::use_facet<codecvt<wchar_t, char, mbstate_t>>(__loc);