mdbx-windows: refine debug-logging.

src/mdbx.c

@@ -1389,6 +1389,30 @@ void __cold mdbx_debug_log(int type, const char *function, int line,
   if (mdbx_debug_logger)
     mdbx_debug_logger(type, function, line, fmt, args);
   else {
+#if defined(_WIN32) || defined(_WIN64)
+    if (IsDebuggerPresent()) {
+      int prefix_len = 0;
+      char *prefix = nullptr;
+      if (function && line > 0)
+        prefix_len = mdbx_asprintf(&prefix, "%s:%d ", function, line);
+      else if (function)
+        prefix_len = mdbx_asprintf(&prefix, "%s: ", function);
+      else if (line > 0)
+        prefix_len = mdbx_asprintf(&prefix, "%d: ", line);
+      if (prefix_len > 0 && prefix) {
+        OutputDebugStringA(prefix);
+        free(prefix);
+      }
+      char *msg = nullptr;
+      int msg_len = mdbx_vasprintf(&msg, fmt, args);
+      if (msg_len > 0 && msg) {
+        OutputDebugStringA(msg);
+        free(msg);
+      }
+      va_end(args);
+      return;
+    }
+#endif
     if (function && line > 0)
       fprintf(stderr, "%s:%d ", function, line);
     else if (function)

src/osal.c

@@ -193,11 +193,9 @@ __cold void mdbx_panic(const char *fmt, ...) {
 
 /*----------------------------------------------------------------------------*/
 
-#ifndef mdbx_asprintf
+#ifndef mdbx_vasprintf
-int mdbx_asprintf(char **strp, const char *fmt, ...) {
+int mdbx_vasprintf(char **strp, const char *fmt, va_list ap) {
-  va_list ap, ones;
+  va_list ones;
-
-  va_start(ap, fmt);
   va_copy(ones, ap);
 #ifdef _MSC_VER
   int needed = _vscprintf(fmt, ap);
@@ -207,7 +205,6 @@ int mdbx_asprintf(char **strp, const char *fmt, ...) {
 #else
 #error FIXME
 #endif
-  va_end(ap);
 
   if (unlikely(needed < 0 || needed >= INT_MAX)) {
     *strp = nullptr;
@@ -218,7 +215,11 @@ int mdbx_asprintf(char **strp, const char *fmt, ...) {
   *strp = malloc(needed + 1);
   if (unlikely(*strp == nullptr)) {
     va_end(ones);
+#if defined(_WIN32) || defined(_WIN64)
     SetLastError(MDBX_ENOMEM);
+#else
+    errno = MDBX_ENOMEM;
+#endif
     return -1;
   }
 
@@ -237,6 +238,16 @@ int mdbx_asprintf(char **strp, const char *fmt, ...) {
   }
   return actual;
 }
+#endif /* mdbx_vasprintf */
+
+#ifndef mdbx_asprintf
+int mdbx_asprintf(char **strp, const char *fmt, ...) {
+  va_list ap;
+  va_start(ap, fmt);
+  int rc = mdbx_vasprintf(strp, fmt, ap);
+  va_end(ap);
+  return rc;
+}
 #endif /* mdbx_asprintf */
 
 #ifndef mdbx_memalign_alloc

src/osal.h

@@ -386,8 +386,10 @@ void mdbx_assert_fail(const MDBX_env *env, const char *msg, const char *func,
 
 #if __GLIBC_PREREQ(2, 1)
 #define mdbx_asprintf asprintf
+#define mdbx_vasprintf vasprintf
 #else
-int mdbx_asprintf(char **strp, const char *fmt, ...);
+__printf_args(2, 3) int mdbx_asprintf(char **strp, const char *fmt, ...);
+int mdbx_vasprintf(char **strp, const char *fmt, va_list ap);
 #endif
 
 #ifdef _MSC_VER