[gcc r13-5248] libstdc++: Deprecate std::filesystem::u8path for C++20

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

https://gcc.gnu.org/g:33237e93d59ee7bb215cd5b726880bcbd679bb36

commit r13-5248-g33237e93d59ee7bb215cd5b726880bcbd679bb36
Author: Jonathan Wakely <jwakely@redhat.com>
Date:   Wed Jan 18 14:27:55 2023 +0000

    libstdc++: Deprecate std::filesystem::u8path for C++20
    
    P0482R6 deprecated these functions for C++20. There was a ballot comment
    on the C++23 CD saying to un-deprecate it, but LEWG just rejected that,
    so let's add attributes to deprecate them.
    
    libstdc++-v3/ChangeLog:
    
            * include/bits/fs_path.h (u8path): Add deprecated attribute.
            * testsuite/27_io/filesystem/path/construct/90281.cc: Add
            -Wno-deprecated-declarations for C++20 and later.
            * testsuite/27_io/filesystem/path/factory/u8path-char8_t.cc:
            Likewise.
            * testsuite/27_io/filesystem/path/factory/u8path.cc: Likewise.
            * testsuite/27_io/filesystem/path/native/string.cc: Likewise.
            * testsuite/27_io/filesystem/path/factory/u8path-depr.cc: New test.

Diff:
---
 libstdc++-v3/include/bits/fs_path.h                      |  2 ++
 .../testsuite/27_io/filesystem/path/construct/90281.cc   |  1 +
 .../27_io/filesystem/path/factory/u8path-char8_t.cc      |  1 +
 .../27_io/filesystem/path/factory/u8path-depr.cc         | 16 ++++++++++++++++
 .../testsuite/27_io/filesystem/path/factory/u8path.cc    |  1 +
 .../testsuite/27_io/filesystem/path/native/string.cc     |  1 +
 6 files changed, 22 insertions(+)

diff --git a/libstdc++-v3/include/bits/fs_path.h b/libstdc++-v3/include/bits/fs_path.h
index 5f18f2314d1..1cbfaaa5427 100644
--- a/libstdc++-v3/include/bits/fs_path.h
+++ b/libstdc++-v3/include/bits/fs_path.h
@@ -808,6 +808,7 @@ namespace __detail
 	   typename _Require = __detail::_Path2<_InputIterator>,
 	   typename _CharT
 	     = __detail::__value_type_is_char_or_char8_t<_InputIterator>>
+    _GLIBCXX20_DEPRECATED_SUGGEST("path(u8string(first, last))")
     inline path
     u8path(_InputIterator __first, _InputIterator __last)
     {
@@ -830,6 +831,7 @@ namespace __detail
   template<typename _Source,
 	   typename _Require = __detail::_Path<_Source>,
 	   typename _CharT = __detail::__value_type_is_char_or_char8_t<_Source>>
+    _GLIBCXX20_DEPRECATED_SUGGEST("path((const char8_t*)&*source)")
     inline path
     u8path(const _Source& __source)
     {
diff --git a/libstdc++-v3/testsuite/27_io/filesystem/path/construct/90281.cc b/libstdc++-v3/testsuite/27_io/filesystem/path/construct/90281.cc
index 4b38646c0e0..d26b5e15b29 100644
--- a/libstdc++-v3/testsuite/27_io/filesystem/path/construct/90281.cc
+++ b/libstdc++-v3/testsuite/27_io/filesystem/path/construct/90281.cc
@@ -16,6 +16,7 @@
 // <http://www.gnu.org/licenses/>.
 
 // { dg-do run { target c++17 } }
+// { dg-additional-options "-Wno-deprecated-declarations" { target c++20 } }
 
 #include <filesystem>
 #include <testsuite_hooks.h>
diff --git a/libstdc++-v3/testsuite/27_io/filesystem/path/factory/u8path-char8_t.cc b/libstdc++-v3/testsuite/27_io/filesystem/path/factory/u8path-char8_t.cc
index ceedd5fbdc2..eff95c18bdf 100644
--- a/libstdc++-v3/testsuite/27_io/filesystem/path/factory/u8path-char8_t.cc
+++ b/libstdc++-v3/testsuite/27_io/filesystem/path/factory/u8path-char8_t.cc
@@ -17,6 +17,7 @@
 
 // { dg-options "-fchar8_t -Wno-stringop-overread" }
 // { dg-do run { target c++17 } }
+// { dg-additional-options "-Wno-deprecated-declarations" { target c++20 } }
 
 #include <filesystem>
 #include <string_view>
diff --git a/libstdc++-v3/testsuite/27_io/filesystem/path/factory/u8path-depr.cc b/libstdc++-v3/testsuite/27_io/filesystem/path/factory/u8path-depr.cc
new file mode 100644
index 00000000000..de54668c055
--- /dev/null
+++ b/libstdc++-v3/testsuite/27_io/filesystem/path/factory/u8path-depr.cc
@@ -0,0 +1,16 @@
+// { dg-options "-std=gnu++20" }
+// { dg-do compile { target c++20 } }
+
+#include <filesystem>
+
+namespace fs = std::filesystem;
+
+const char* s = "";
+auto p1 = fs::u8path(s); // { dg-warning "deprecated" }
+auto p2 = fs::u8path(s, s); // { dg-warning "deprecated" }
+
+#if __cpp_lib_char8_t
+const char8_t* u = u8"";
+auto p3 = fs::u8path(u); // { dg-warning "deprecated" }
+auto p4 = fs::u8path(u, u); // { dg-warning "deprecated" }
+#endif
diff --git a/libstdc++-v3/testsuite/27_io/filesystem/path/factory/u8path.cc b/libstdc++-v3/testsuite/27_io/filesystem/path/factory/u8path.cc
index 726b3eaadd8..4c41fc28da9 100644
--- a/libstdc++-v3/testsuite/27_io/filesystem/path/factory/u8path.cc
+++ b/libstdc++-v3/testsuite/27_io/filesystem/path/factory/u8path.cc
@@ -16,6 +16,7 @@
 // <http://www.gnu.org/licenses/>.
 
 // { dg-do run { target c++17 } }
+// { dg-additional-options "-Wno-deprecated-declarations" { target c++20 } }
 
 #include <filesystem>
 #include <string_view>
diff --git a/libstdc++-v3/testsuite/27_io/filesystem/path/native/string.cc b/libstdc++-v3/testsuite/27_io/filesystem/path/native/string.cc
index 8620c15fa88..d5942c9beaa 100644
--- a/libstdc++-v3/testsuite/27_io/filesystem/path/native/string.cc
+++ b/libstdc++-v3/testsuite/27_io/filesystem/path/native/string.cc
@@ -16,6 +16,7 @@
 // <http://www.gnu.org/licenses/>.
 
 // { dg-do run { target c++17 } }
+// { dg-additional-options "-Wno-deprecated-declarations" { target c++20 } }
 
 #include <filesystem>
 #include <string>