util: fix compilation with mingw-w64 7.0.0

Author: Fuzzbawls

configure.ac

@@ -863,6 +863,22 @@ if test "x$use_thread_local" = xyes || { test "x$use_thread_local" = xauto && te
   LDFLAGS="$TEMP_LDFLAGS"
 fi
 
+dnl check for gmtime_r(), fallback to gmtime_s() if that is unavailable
+dnl fail if neither are available.
+AC_MSG_CHECKING(for gmtime_r)
+AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[#include <ctime>]],
+  [[ gmtime_r((const time_t *) nullptr, (struct tm *) nullptr); ]])],
+  [ AC_MSG_RESULT(yes); AC_DEFINE(HAVE_GMTIME_R, 1, [Define this symbol if gmtime_r is available]) ],
+  [ AC_MSG_RESULT(no);
+    AC_MSG_CHECKING(for gmtime_s);
+    AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[#include <ctime>]],
+       [[ gmtime_s((struct tm *) nullptr, (const time_t *) nullptr); ]])],
+       [ AC_MSG_RESULT(yes)],
+       [ AC_MSG_RESULT(no); AC_MSG_ERROR(Both gmtime_r and gmtime_s are unavailable) ]
+    )
+  ]
+)
+
 # Check for different ways of gathering OS randomness
 AC_MSG_CHECKING(for Linux getrandom syscall)
 AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[#include <unistd.h>
@@ -1493,6 +1509,7 @@ AC_SUBST(PROTOBUF_LIBS)
 AC_SUBST(QR_LIBS)
 AC_SUBST(USE_NUM_GMP)
 AC_SUBST(USE_NUM_OPENSSL)
+AC_SUBST(HAVE_GMTIME_R)
 AC_SUBST(HAVE_FDATASYNC)
 AC_SUBST(HAVE_FULLFSYNC)
 AC_SUBST(HAVE_O_CLOEXEC)

src/utiltime.cpp

@@ -99,10 +99,10 @@ std::string DurationToDHMS(int64_t nDurationTime)
 std::string FormatISO8601DateTime(int64_t nTime) {
     struct tm ts;
     time_t time_val = nTime;
-#ifdef _MSC_VER
-    if (gmtime_s(&ts, &time_val) != 0) {
-#else
+#ifdef HAVE_GMTIME_R
     if (gmtime_r(&time_val, &ts) == nullptr) {
+#else
+    if (gmtime_s(&ts, &time_val) != 0) {
 #endif
         return {};
     }
@@ -112,10 +112,10 @@ std::string FormatISO8601DateTime(int64_t nTime) {
 std::string FormatISO8601DateTimeForBackup(int64_t nTime) {
     struct tm ts;
     time_t time_val = nTime;
-#ifdef _MSC_VER
-    if (gmtime_s(&ts, &time_val) != 0) {
-#else
+#ifdef HAVE_GMTIME_R
     if (gmtime_r(&time_val, &ts) == nullptr) {
+#else
+    if (gmtime_s(&ts, &time_val) != 0) {
 #endif
         return {};
     }
@@ -125,10 +125,10 @@ std::string FormatISO8601DateTimeForBackup(int64_t nTime) {
 std::string FormatISO8601Date(int64_t nTime) {
     struct tm ts;
     time_t time_val = nTime;
-#ifdef _MSC_VER
-    if (gmtime_s(&ts, &time_val) != 0) {
-#else
+#ifdef HAVE_GMTIME_R
     if (gmtime_r(&time_val, &ts) == nullptr) {
+#else
+    if (gmtime_s(&ts, &time_val) != 0) {
 #endif
         return {};
     }
@@ -138,10 +138,10 @@ std::string FormatISO8601Date(int64_t nTime) {
 std::string FormatISO8601Time(int64_t nTime) {
     struct tm ts;
     time_t time_val = nTime;
-#ifdef _MSC_VER
-    if (gmtime_s(&ts, &time_val) != 0) {
-#else
+#ifdef HAVE_GMTIME_R
     if (gmtime_r(&time_val, &ts) == nullptr) {
+#else
+    if (gmtime_s(&ts, &time_val) != 0) {
 #endif
         return {};
     }