Fix gmtime etc in STANDALONE_WASM mode (#22316)

This was broken in #21379.

Replaces: #22276

Author: sbc100

src/library.js

@@ -446,15 +446,14 @@ addToLibrary({
 
 #endif
 
+#if !STANDALONE_WASM
   // ==========================================================================
   // assert.h
   // ==========================================================================
 
-#if !STANDALONE_WASM
   __assert_fail: (condition, filename, line, func) => {
     abort(`Assertion failed: ${UTF8ToString(condition)}, at: ` + [filename ? UTF8ToString(filename) : 'unknown filename', line, func ? UTF8ToString(func) : 'unknown function']);
   },
-#endif
 
   // ==========================================================================
   // time.h
@@ -595,6 +594,7 @@ addToLibrary({
     stringToUTF8(s, buf, 26);
     return buf;
   },
+#endif
 
 #if STACK_OVERFLOW_CHECK >= 2
   // Set stack limits used by binaryen's `StackCheck` pass.
@@ -626,6 +626,7 @@ addToLibrary({
     return ret;
   },
 
+#if !STANDALONE_WASM
   _tzset_js__deps: ['$stringToUTF8',
 #if ASSERTIONS
     '$lengthBytesUTF8',
@@ -686,6 +687,7 @@ addToLibrary({
       stringToUTF8(summerName, std_name, {{{ cDefs.TZNAME_MAX + 1 }}});
     }
   },
+#endif
 
   $MONTH_DAYS_REGULAR: [31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31],
   $MONTH_DAYS_LEAP: [31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31],

system/lib/libc/musl/src/time/__tz.c

@@ -15,37 +15,45 @@
 #include "emscripten_internal.h"
 #endif
 
+#if defined(__EMSCRIPTEN__) && !defined(EMSCRIPTEN_STANDALONE_WASM)
+#define USE_EXTERNAL_ZONEINFO
+#endif
+
 #define malloc __libc_malloc
 #define calloc undef
 #define realloc undef
 #define free undef
 
-long  __timezone = 0;
-int   __daylight = 0;
-char *__tzname[2] = { 0, 0 };
+weak long  __timezone = 0;
+weak int   __daylight = 0;
+weak char *__tzname[2] = { 0, 0 };
 
 weak_alias(__timezone, timezone);
 weak_alias(__daylight, daylight);
 weak_alias(__tzname, tzname);
 
 static char std_name[TZNAME_MAX+1];
 static char dst_name[TZNAME_MAX+1];
-const char __utc[] = "UTC";
+weak const char __utc[] = "UTC";
 
 static int dst_off;
 static int r0[5], r1[5];
 
+#ifndef USE_EXTERNAL_ZONEINFO
 static const unsigned char *zi, *trans, *index, *types, *abbrevs, *abbrevs_end;
 static size_t map_size;
+#endif
 
 static char old_tz_buf[32];
 static char *old_tz = old_tz_buf;
 static size_t old_tz_size = sizeof old_tz_buf;
 
 static volatile int lock[1];
+#ifndef __EMSCRIPTEN__
 volatile int *const __timezone_lockptr = lock;
+#endif
 
-#ifndef __EMSCRIPTEN__
+#ifndef USE_EXTERNAL_ZONEINFO
 static int getint(const char **p)
 {
 	unsigned x;
@@ -133,7 +141,7 @@ static size_t zi_dotprod(const unsigned char *z, const unsigned char *v, size_t
 
 static void do_tzset()
 {
-#ifdef __EMSCRIPTEN__
+#ifdef USE_EXTERNAL_ZONEINFO
 	static pthread_mutex_t lock = PTHREAD_MUTEX_INITIALIZER;
 	static _Atomic bool done_init = false;
 	if (!done_init) {
@@ -280,7 +288,7 @@ static void do_tzset()
 #endif
 }
 
-#ifndef __EMSCRIPTEN__
+#ifndef USE_EXTERNAL_ZONEINFO
 /* Search zoneinfo rules to find the one that applies to the given time,
  * and determine alternate opposite-DST-status rule that may be needed. */
 
@@ -451,14 +459,16 @@ static void __tzset()
 
 weak_alias(__tzset, tzset);
 
-const char *__tm_to_tzname(const struct tm *tm)
+weak const char *__tm_to_tzname(const struct tm *tm)
 {
 	const void *p = tm->__tm_zone;
 	LOCK(lock);
 	do_tzset();
+#ifndef USE_EXTERNAL_ZONEINFO
 	if (p != __utc && p != __tzname[0] && p != __tzname[1] &&
 	    (!zi || (uintptr_t)p-(uintptr_t)abbrevs >= abbrevs_end - abbrevs))
 		p = "";
+#endif
 	UNLOCK(lock);
 	return p;
 }

test/core/test_time.c

@@ -26,10 +26,10 @@ void check_gmtime_localtime(time_t time) {
 
   // gmtime and localtime are only equal when timezone is UTC
   if ((timezone == 0) && (strcmp(gmbuf, locbuf) != 0)) {
-    printf("time: %lld, gmtime: %s != localtime: %s\n", time, gmbuf, locbuf);
+    printf("time: %lld, gmtime: %s != localtime: %s\n", (long long)time, gmbuf, locbuf);
     puts("failed");
   } else {
-    printf("time: %lld, gmtime: %s\n", time, gmbuf);
+    printf("time: %lld, gmtime: %s\n", (long long)time, gmbuf);
   }
 }
 
@@ -38,13 +38,14 @@ int main() {
   time_t summer2002 = 1025528525ll;
   struct tm* tm_ptr;
 
+#ifdef __EMSCRIPTEN__
   // Make sure stime() always fails.
   printf("stime: %d\n", stime(&xmas2002));
+#endif
 
   // Verify that tzname sets *something*.
   tzset();
   printf("tzname[0] set: %d\n", strlen(tzname[0]) >= 3);
-  printf("tzname[1] set: %d\n", strlen(tzname[1]) >= 3);
 
   // Verify gmtime() creates correct struct.
   tm_ptr = gmtime(&xmas2002);
@@ -58,7 +59,8 @@ int main() {
   printf("yday: %d\n", tm_ptr->tm_yday);
   printf("dst: %d\n", tm_ptr->tm_isdst);
   printf("off: %ld\n", (long)tm_ptr->tm_gmtoff);
-  printf("zone: %s\n", tm_ptr->tm_zone);
+  // glibc used "GMT" there whereas musl uses "UTC"
+  assert(strcmp(tm_ptr->tm_zone, "GMT") || strcmp(tm_ptr->tm_zone, "UTC"));
 
   // Verify timegm() reverses gmtime; run through an entire year in half hours.
   int timegmOk = 1;
@@ -89,7 +91,7 @@ int main() {
   printf("localtime found DST data (summer): %s\n", tm_summer.tm_isdst < 0 ? "no" : "yes");
   printf("localtime found DST data (winter): %s\n", tm_winter.tm_isdst < 0 ? "no" : "yes");
   int localeHasDst = tm_winter.tm_isdst == 1 || tm_summer.tm_isdst == 1; // DST is in December in south
-  printf("localtime matches daylight: %s\n", localeHasDst == _daylight ? "yes" : "no");
+  printf("localtime matches daylight: %s\n", localeHasDst == daylight ? "yes" : "no");
   int goodGmtOff = (tm_winter.tm_gmtoff != tm_summer.tm_gmtoff) == localeHasDst;
   printf("localtime gmtoff matches DST: %s\n", goodGmtOff ? "yes" : "no");
   printf("localtime tm_zone matches tzname (winter): %s\n",
@@ -169,9 +171,7 @@ int main() {
   struct tm tm_big = {0};
   tm_big.tm_year = 292278994;
   time_t tbig = mktime(&tm_big);
-  printf("tbig: %lld\n", tbig);
-  assert(tbig == -1);
-  assert(errno == EOVERFLOW);
+  assert((tbig == -1 && errno == EOVERFLOW) || tbig == 9223431975273600);
 
   // Verify localtime_r() doesn't clobber static data.
   time_t t3 = 60*60*24*5; // Jan 5 1970

test/core/test_time.out

@@ -1,6 +1,5 @@
 stime: -1
 tzname[0] set: 1
-tzname[1] set: 1
 sec: 43
 min: 22
 hour: 3
@@ -11,7 +10,6 @@ wday: 3
 yday: 358
 dst: 0
 off: 0
-zone: GMT
 timegm <-> gmtime: 1
 old year still: 102
 new year: 70
@@ -27,7 +25,6 @@ mktime updates parameter to be in range: 1
 mktime parameter is equivalent to localtime return: 1
 mktime guesses DST (winter): 1
 mktime guesses DST (summer): 1
-tbig: -1
 old year still: 102
 new year: 70
 time: 1

test/test_core.py

@@ -2668,6 +2668,7 @@ def test_pthread_run_on_main_thread(self):
   def test_tcgetattr(self):
     self.do_runf('termios/test_tcgetattr.c', 'success')
 
+  @also_with_standalone_wasm()
   def test_time(self):
     self.do_core_test('test_time.c')
     for tz in ['EST+05EDT', 'UTC+0', 'CET']:

tools/system_libs.py

@@ -2197,6 +2197,7 @@ def get_files(self):
     files += files_in_path(
         path='system/lib/libc/musl/src/time',
         filenames=['__secs_to_tm.c',
+                   '__tz.c',
                    'clock.c',
                    'clock_gettime.c',
                    'gettimeofday.c',