Am 07.07.2025 um 23:02 schrieb Jonathan Wakely:
On Mon, 7 Jul 2025 at 22:01, Jonathan Wakely <jwak...@redhat.com> wrote:
On Mon, 7 Jul 2025 at 21:26, Björn Schäpers <g...@hazardy.de> wrote:
From: Björn Schäpers <bjo...@hazardy.de>
Sorry for the noise, this is the current version of the Patch.
-- >8 --
Windows does not provide a tzdata.zi, but msys does. Use this, if
available, instead of the embedded (and possibly outdated) database.
libstdc++-v3/Changelog:
Use msys provided time zone information.
* src/c++20/tzdb.cc (zoneinfo_file): On Windows look relative
from the DLL path for the time zone information.
Signed-off-by: Björn Schäpers <bjo...@hazardy.de>
---
libstdc++-v3/src/c++20/tzdb.cc | 35 ++++++++++++++++++++++++++++++++++
1 file changed, 35 insertions(+)
diff --git a/libstdc++-v3/src/c++20/tzdb.cc b/libstdc++-v3/src/c++20/tzdb.cc
index 6e244dc656d..cdc487af3f5 100644
--- a/libstdc++-v3/src/c++20/tzdb.cc
+++ b/libstdc++-v3/src/c++20/tzdb.cc
@@ -44,6 +44,12 @@
# include <cstdlib> // getenv
#endif
+#if _GLIBCXX_HAVE_WINDOWS_H
+# define WIN32_LEAN_AND_MEAN
+# include <windows.h>
+# include <psapi.h>
+#endif
+
#if defined __GTHREADS && ATOMIC_POINTER_LOCK_FREE == 2
# define USE_ATOMIC_LIST_HEAD 1
// TODO benchmark atomic<shared_ptr<>> vs mutex.
@@ -1144,6 +1150,35 @@ namespace std::chrono
#ifdef _GLIBCXX_ZONEINFO_DIR
else
path = _GLIBCXX_ZONEINFO_DIR;
+#endif
+#ifdef _GLIBCXX_HAVE_WINDOWS_H
+ if (path.empty())
+ {
+ HMODULE dll_module;
+ if (GetModuleHandleExA(
+ GET_MODULE_HANDLE_EX_FLAG_FROM_ADDRESS
+ | GET_MODULE_HANDLE_EX_FLAG_UNCHANGED_REFCOUNT,
+ reinterpret_cast<const char *>(&zoneinfo_file), &dll_module))
+ {
+ char dll_path[MAX_PATH];
+ if (GetModuleFileNameA(dll_module, dll_path, MAX_PATH) != 0)
+ {
+ string_view dll_path_view = dll_path;
+ auto pos = dll_path_view.find_last_of('\\');
+ dll_path_view = dll_path_view.substr(0, pos);
+ if (dll_path_view.ends_with("\\bin"))
+ {
+ constexpr string_view remaining_path = "share\\zoneinfo";
+ dll_path_view.remove_suffix(3); // Remove bin
+ path.resize(dll_path_view.size()
+ + remaining_path.size());
+ auto iter
+ = ranges::copy(dll_path_view, path.begin()).out;
+ ranges::copy(remaining_path, iter);
Why not simply:
path = dll_path_view;
path += remaining_path;
?
And reserve not resize before that.
Just the style I prefer and no additional size check (though the compiler might
remove that anyway). I can change that.
+ }
+ }
+ }
+ }
#endif
if (!path.empty())
path.append(filename);
--
2.50.0
