m4: Add PRIdTIME_T and PRIxTIME_T format specifiers

configure.ac

@@ -473,7 +473,7 @@ fi
 
 DOVECOT_TM_GMTOFF
 DOVECOT_GMTIME_MAX
-DOVECOT_TIME_T_SIGNED
+DOVECOT_TIME_T
 
 DOVECOT_C_STATIC_ARRAY
 DOVECOT_C_FLEXIBLE_ARRAY_MEMBER

m4/time_t.m4

@@ -0,0 +1,42 @@
+AC_DEFUN([DOVECOT_TIME_T], [
+  AC_TYPEOF(time_t, long int long-long unsigned-int unsigned-long unsigned-long-long)
+  case "$typeof_time_t" in
+    long)
+      timet_len="l"
+      i_cv_signed_time_t=yes
+      ;;
+    int)
+      timet_len=""
+      i_cv_signed_time_t=yes
+      ;;
+    "long long")
+      timet_len="ll"
+      i_cv_signed_time_t=yes
+      ;;
+    "unsigned int")
+      timet_len=""
+      i_cv_signed_time_t=no
+      ;;
+    "unsigned long")
+      timet_len="l"
+      i_cv_signed_time_t=no
+      ;;
+    "unsigned long long")
+      timet_len="ll"
+      i_cv_signed_time_t=no
+      ;;
+    *)
+      AC_MSG_ERROR([Unsupported time_t type])
+      ;;
+  esac
+  if test $i_cv_signed_time_t = yes; then
+    AC_DEFINE(TIME_T_SIGNED,, [Define if your time_t is signed])
+    timet_d_fmt="$timet_len"d
+  else
+    timet_d_fmt="$timet_len"u
+  fi
+  timet_x_fmt="$timet_len"x
+
+  AC_DEFINE_UNQUOTED(PRIdTIME_T, "$timet_d_fmt", [printf() fmt for dec time_t])
+  AC_DEFINE_UNQUOTED(PRIxTIME_T, "$timet_x_fmt", [printf() fmt for hex time_t])
+])