Fix Windows locale and error messages

Signed-off-by: Andrew Opalach <andrew@akon.city>

2 files changed, 38 insertions, 9 deletions

diff --git a/src/util/error.c b/src/util/error.c
index 46fd8e6..7f2e847 100644
--- a/src/util/error.c
+++ b/src/util/error.c
@@ -1,6 +1,9 @@
 #include "error.h"
 
 static __thread char errorbuf[NNWT_ERROR_STR_MAXLEN];
+#ifdef NAUNET_ON_WINDOWS
+static __thread wchar_t errorbufw[NNWT_ERROR_STR_MAXLEN];
+#endif
 
 char *nn_strerror(s32 errnum)
 {
@@ -19,21 +22,31 @@ char *nn_strerror(s32 errnum)
 #ifdef NAUNET_ON_WINDOWS
 #include "../winwrap.h"
 
-// @TODO: GetLastError() should be used in common places like file_stdio.
+#include <wchar.h>
 
 // https://stackoverflow.com/a/46104456
 char *nn_win32_error_message(s32 err)
 {
-    /*
-    DWORD ret = FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS,
+    DWORD ret = FormatMessageW(FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS,
         NULL,
         err,
-        MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
-        errorbuf,
+        0,
+        errorbufw,
         NNWT_ERROR_STR_MAXLEN,
         NULL);
-    return !ret ? NULL : errorbuf;
-    */
-    return NULL;
+    if (!ret) {
+        return NULL;
+    }
+    errorbufw[ret] = L'\0';
+    mbstate_t mbstate = { 0 };
+    wchar_t *wc = errorbufw;
+    size_t length = wcsrtombs(NULL, (const wchar_t **)&wc, 0, &mbstate);
+    if (length == (size_t)-1) {
+        return NULL;
+    }
+    length = wcsrtombs(errorbuf, (const wchar_t **)&wc, length, &mbstate);
+    al_assert(length < NNWT_ERROR_STR_MAXLEN);
+    errorbuf[length] = L'\0';
+    return errorbuf;
 }
 #endif
diff --git a/src/util/file/file_stdio.c b/src/util/file/file_stdio.c
index 5bdc7d9..6a30137 100644
--- a/src/util/file/file_stdio.c
+++ b/src/util/file/file_stdio.c
@@ -4,12 +4,27 @@
 
 #ifdef NAUNET_ON_WINDOWS
 #include "../../winwrap.h"
+#else
+#include <unistd.h>
 #endif
 
 #include "../error.h"
 
 #include "file.h"
 
+static void check_error_description(s32 err)
+{
+#ifdef NAUNET_ON_WINDOWS
+    err = GetLastError();
+    char *strerror = nn_win32_error_message(err);
+    if (strerror) {
+        log_error("Error description: %s.", strerror);
+    }
+#else
+    log_error("Error description: %s.", nn_strerror(err));
+#endif
+}
+
 static inline bool open_stdio_file(FILE **file, str *path, const char *mode)
 {
     char *c_str = al_str_to_c_str(path);
@@ -34,7 +49,8 @@ bool nn_file_open(struct nn_file *file, str *path, s32 flags)
 {
     const char *mode = (flags & NNWT_FILE_CREATE) ? "wb+" : "rb+";
     if (!open_stdio_file(&file->file, path, mode)) {
-        log_error("fopen(%.*s) failed (%d: %s).", al_str_x(path), errno, nn_strerror(errno));
+        log_error("fopen(%.*s) failed (%d).", al_str_x(path), errno);
+        check_error_description(errno);
         return false;
     }