change sopen_s to wsopen_s (fmtlib#3234)

include/fmt/os.h

@@ -337,6 +337,11 @@ class FMT_API file {
   // Creates a buffered_file object associated with this file and detaches
   // this file object from the file.
   buffered_file fdopen(const char* mode);
+
+  # if defined(_WIN32) && !defined(__MINGW32__)
+  // Opens a file and constructs a file object representing this file by wcstring_view filename. Windows only.
+  static file open_windows_file(wcstring_view path, int oflag);
+  #endif
 };
 
 // Returns the memory page size.

src/os.cc

@@ -213,21 +213,23 @@ int buffered_file::descriptor() const {
 }
 
 #if FMT_USE_FCNTL
-file::file(cstring_view path, int oflag) {
 #  ifdef _WIN32
-  using mode_t = int;
+using mode_t = int;
 #  endif
-  constexpr mode_t mode =
-      S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH;
+constexpr mode_t default_open_mode =
+    S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH;
+
+file::file(cstring_view path, int oflag) {
 #  if defined(_WIN32) && !defined(__MINGW32__)
   fd_ = -1;
-  FMT_POSIX_CALL(sopen_s(&fd_, path.c_str(), oflag, _SH_DENYNO, mode));
+  auto converted = detail::utf8_to_utf16(string_view(path.c_str()));
+  *this = file::open_windows_file(converted.c_str(), oflag);
 #  else
-  FMT_RETRY(fd_, FMT_POSIX_CALL(open(path.c_str(), oflag, mode)));
-#  endif
+  FMT_RETRY(fd_, FMT_POSIX_CALL(open(path.c_str(), oflag, default_open_mode)));
   if (fd_ == -1)
     FMT_THROW(
         system_error(errno, FMT_STRING("cannot open file {}"), path.c_str()));
+#  endif
 }
 
 file::~file() noexcept {
@@ -353,6 +355,18 @@ buffered_file file::fdopen(const char* mode) {
   return bf;
 }
 
+#  if defined(_WIN32) && !defined(__MINGW32__)
+file file::open_windows_file(wcstring_view path, int oflag) {
+  int fd_ = -1;
+  auto err =
+      _wsopen_s(&fd_, path.c_str(), oflag, _SH_DENYNO, default_open_mode);
+  if (fd_ == -1)
+    FMT_THROW(system_error(err, FMT_STRING("cannot open file {}"),
+                           detail::utf16_to_utf8(path.c_str()).c_str()));
+  return file(fd_);
+}
+#  endif
+
 long getpagesize() {
 #  ifdef _WIN32
   SYSTEM_INFO si;

test/os-test.cc

@@ -127,6 +127,17 @@ TEST(os_test, report_windows_error) {
                fmt::to_string(out));
 }
 
+#  if FMT_USE_FCNTL && !defined(__MINGW32__)
+TEST(file_test, open_windows_file) {
+  using fmt::file;
+  file out = file::open_windows_file(L"test-file",
+                                     file::WRONLY | file::CREATE | file::TRUNC);
+  out.write("x", 1);
+  file in = file::open_windows_file(L"test-file", file::RDONLY);
+  EXPECT_READ(in, "x");
+}
+#  endif  // FMT_USE_FCNTL && !defined(__MINGW32__)
+
 #endif  // _WIN32
 
 #if FMT_USE_FCNTL

test/posix-mock-test.cc

@@ -72,12 +72,6 @@ int test::open(const char* path, int oflag, int mode) {
   EMULATE_EINTR(open, -1);
   return ::open(path, oflag, mode);
 }
-#else
-errno_t test::sopen_s(int* pfh, const char* filename, int oflag, int shflag,
-                      int pmode) {
-  EMULATE_EINTR(open, EINTR);
-  return _sopen_s(pfh, filename, oflag, shflag, pmode);
-}
 #endif
 
 #ifndef _WIN32
@@ -220,11 +214,11 @@ TEST(os_test, getpagesize) {
 }
 
 TEST(file_test, open_retry) {
+#  ifndef _WIN32
   write_file("temp", "there must be something here");
   std::unique_ptr<file> f{nullptr};
   EXPECT_RETRY(f.reset(new file("temp", file::RDONLY)), open,
                "cannot open file temp");
-#  ifndef _WIN32
   char c = 0;
   f->read(&c, 1);
 #  endif

test/posix-mock.h

@@ -37,8 +37,6 @@ int fstat(int fd, struct stat* buf);
 #else
 typedef unsigned size_t;
 typedef int ssize_t;
-errno_t sopen_s(int* pfh, const char* filename, int oflag, int shflag,
-                int pmode);
 #endif
 
 #ifndef _WIN32