xtime: Call tzset() from main() instead of lazily

POSIX specifies[1] that

    If a thread accesses tzname, daylight, or timezone directly while
    another thread is in a call to tzset(), or to any function that is
    required or allowed to set timezone information as if by calling
    tzset(), the behavior is undefined.

So calling it lazily from arbitrary threads is risky.

[1]: https://pubs.opengroup.org/onlinepubs/9699919799/functions/tzset.html

1 files changed, 6 insertions, 6 deletions

diff --git a/src/parse.c b/src/parse.c
index 5d0f333..b26a50f 100644
--- a/src/parse.c
+++ b/src/parse.c
@@ -1086,8 +1086,8 @@ static struct bfs_expr *parse_const(struct bfs_parser *parser, int value, int ar
  */
 static struct bfs_expr *parse_daystart(struct bfs_parser *parser, int arg1, int arg2) {
 	struct tm tm;
-	if (xlocaltime(&parser->now.tv_sec, &tm) != 0) {
-		parse_perror(parser, "xlocaltime()");
+	if (!localtime_r(&parser->now.tv_sec, &tm)) {
+		parse_perror(parser, "localtime_r()");
 		return NULL;
 	}
 
@@ -1708,8 +1708,8 @@ static int parse_reftime(const struct bfs_parser *parser, struct bfs_expr *expr)
 	fprintf(stderr, "Supported timestamp formats are ISO 8601-like, e.g.\n\n");
 
 	struct tm tm;
-	if (xlocaltime(&parser->now.tv_sec, &tm) != 0) {
-		parse_perror(parser, "xlocaltime()");
+	if (!localtime_r(&parser->now.tv_sec, &tm)) {
+		parse_perror(parser, "localtime_r()");
 		return -1;
 	}
 
@@ -1728,8 +1728,8 @@ static int parse_reftime(const struct bfs_parser *parser, struct bfs_expr *expr)
 	fprintf(stderr, "  - %04d-%02d-%02dT%02d:%02d:%02d%+03d:%02d\n",
 		year, month, tm.tm_mday, tm.tm_hour, tm.tm_min, tm.tm_sec, tz_hour, tz_min);
 
-	if (xgmtime(&parser->now.tv_sec, &tm) != 0) {
-		parse_perror(parser, "xgmtime()");
+	if (!gmtime_r(&parser->now.tv_sec, &tm)) {
+		parse_perror(parser, "gmtime_r()");
 		return -1;
 	}