Better support for / separators on Windows, improve wchar filename coverage

include/spdlog/common.h

@@ -88,7 +88,9 @@ class sink;
 
 #if defined(_WIN32) && defined(SPDLOG_WCHAR_FILENAMES)
 using filename_t = std::wstring;
-#define SPDLOG_FILENAME_T(s) L##s
+// allow macro expansion to occur in SPDLOG_FILENAME_T
+#define SPDLOG_FILENAME_T_INNER(s) L##s
+#define SPDLOG_FILENAME_T(s) SPDLOG_FILENAME_T_INNER(s)
 #else
 using filename_t = std::string;
 #define SPDLOG_FILENAME_T(s) s
@@ -101,6 +103,7 @@ using err_handler = std::function<void(const std::string &err_msg)>;
 using string_view_t = fmt::basic_string_view<char>;
 using wstring_view_t = fmt::basic_string_view<wchar_t>;
 using memory_buf_t = fmt::basic_memory_buffer<char, 250>;
+using filename_memory_buf_t = fmt::basic_memory_buffer<filename_t::value_type, 250>;
 
 #ifdef SPDLOG_WCHAR_TO_UTF8_SUPPORT
 #ifndef _WIN32

include/spdlog/details/file_helper-inl.h

@@ -118,7 +118,7 @@ SPDLOG_INLINE std::tuple<filename_t, filename_t> file_helper::split_by_extension
     }
 
     // treat cases like "/etc/rc.d/somelogfile or "/abc/.hiddenfile"
-    auto folder_index = fname.rfind(details::os::folder_sep);
+    auto folder_index = fname.find_last_of(details::os::folder_seps_filename);
     if (folder_index != filename_t::npos && folder_index >= ext_index - 1)
     {
         return std::make_tuple(fname, filename_t());

include/spdlog/details/os-inl.h

@@ -533,15 +533,10 @@ SPDLOG_INLINE bool create_dir(filename_t path)
         return false;
     }
 
-#ifdef _WIN32
-    // support forward slash in windows
-    std::replace(path.begin(), path.end(), '/', folder_sep);
-#endif
-
     size_t search_offset = 0;
     do
     {
-        auto token_pos = path.find(folder_sep, search_offset);
+        auto token_pos = path.find_first_of(folder_seps_filename, search_offset);
         // treat the entire path as a folder if no folder separator not found
         if (token_pos == filename_t::npos)
         {
@@ -567,11 +562,7 @@ SPDLOG_INLINE bool create_dir(filename_t path)
 // "abc///" => "abc//"
 SPDLOG_INLINE filename_t dir_name(filename_t path)
 {
-#ifdef _WIN32
-    // support forward slash in windows
-    std::replace(path.begin(), path.end(), '/', folder_sep);
-#endif
-    auto pos = path.find_last_of(folder_sep);
+    auto pos = path.find_last_of(folder_seps_filename);
     return pos != filename_t::npos ? path.substr(0, pos) : filename_t{};
 }
 

include/spdlog/details/os.h

@@ -32,11 +32,16 @@ SPDLOG_API std::tm gmtime() SPDLOG_NOEXCEPT;
 SPDLOG_CONSTEXPR static const char *default_eol = SPDLOG_EOL;
 
 // folder separator
+#if !defined(SPDLOG_FOLDER_SEPS)
 #ifdef _WIN32
-static const char folder_sep = '\\';
+#define SPDLOG_FOLDER_SEPS "\\/"
 #else
-SPDLOG_CONSTEXPR static const char folder_sep = '/';
+#define SPDLOG_FOLDER_SEPS "/"
 #endif
+#endif
+
+SPDLOG_CONSTEXPR static const char folder_seps[] = SPDLOG_FOLDER_SEPS;
+SPDLOG_CONSTEXPR static const filename_t::value_type folder_seps_filename[] = SPDLOG_FILENAME_T(SPDLOG_FOLDER_SEPS);
 
 // fopen_s on non windows for writing
 SPDLOG_API bool fopen_s(FILE **fp, const filename_t &filename, const filename_t &mode);

include/spdlog/pattern_formatter-inl.h

@@ -13,11 +13,13 @@
 #include <spdlog/fmt/fmt.h>
 #include <spdlog/formatter.h>
 
+#include <algorithm>
 #include <array>
 #include <chrono>
 #include <ctime>
 #include <cctype>
 #include <cstring>
+#include <iterator>
 #include <memory>
 #include <mutex>
 #include <string>
@@ -814,11 +816,31 @@ public:
         : flag_formatter(padinfo)
     {}
 
+#ifdef _MSC_VER
+#pragma warning(push)
+#pragma warning(disable : 4127) // consider using 'if constexpr' instead
+#endif // _MSC_VER
     static const char *basename(const char *filename)
     {
-        const char *rv = std::strrchr(filename, os::folder_sep);
-        return rv != nullptr ? rv + 1 : filename;
+        // if the size is 2 (1 character + null terminator) we can use the more efficient strrchr
+        // the branch will be elided by optimizations
+        if (sizeof(os::folder_seps) == 2)
+        {
+            const char *rv = std::strrchr(filename, os::folder_seps[0]);
+            return rv != nullptr ? rv + 1 : filename;
+        }
+        else
+        {
+            const std::reverse_iterator<const char*> begin(filename + std::strlen(filename));
+            const std::reverse_iterator<const char*> end(filename);
+
+            const auto it = std::find_first_of(begin, end, std::begin(os::folder_seps), std::end(os::folder_seps) - 1);
+            return it != end ? it.base() : filename;
+        }
     }
+#ifdef _MSC_VER
+#pragma warning(pop)
+#endif // _MSC_VER
 
     void format(const details::log_msg &msg, const std::tm &, memory_buf_t &dest) override
     {

include/spdlog/tweakme.h

@@ -58,6 +58,14 @@
 // #define SPDLOG_EOL ";-)\n"
 ///////////////////////////////////////////////////////////////////////////////
 
+///////////////////////////////////////////////////////////////////////////////
+// Uncomment to override default folder separators ("/" or "\\/" under
+// Linux/Windows). Each character in the string is treated as a different
+// separator.
+//
+// #define SPDLOG_FOLDER_SEPS "\\"
+///////////////////////////////////////////////////////////////////////////////
+
 ///////////////////////////////////////////////////////////////////////////////
 // Uncomment to use your own copy of the fmt library instead of spdlog's copy.
 // In this case spdlog will try to include <fmt/format.h> so set your -I flag