[libcxx-commits] [libcxx] [libc++][chrono] Loads tzdata.zi in tzdb. (PR #74928)

[Mark de Wever via libcxx-commits]

================
@@ -109,13 +497,108 @@ static string __parse_version(istream& __input) {
   return chrono::__parse_string(__input);
 }
 
+static void __parse_rule(tzdb& __tzdb, istream& __input) {
+  chrono::__skip_mandatory_whitespace(__input);
+  string __name = chrono::__parse_string(__input);
+
+  if (__tzdb.__rules.empty() || __tzdb.__rules.back().first != __name)
+    __tzdb.__rules.emplace_back(__name, vector<__tz::__rule>{});
+
+  __tz::__rule& __rule = __tzdb.__rules.back().second.emplace_back();
+
+  chrono::__skip_mandatory_whitespace(__input);
+  __rule.__from = chrono::__parse_year(__input);
+  chrono::__skip_mandatory_whitespace(__input);
+  __rule.__to = chrono::__parse_to(__input, __rule.__from);
+  chrono::__skip_mandatory_whitespace(__input);
+  chrono::__matches(__input, '-');
+  chrono::__skip_mandatory_whitespace(__input);
+  __rule.__in_month = chrono::__parse_month(__input);
+  chrono::__skip_mandatory_whitespace(__input);
+  __rule.__on = chrono::__parse_on(__input);
+  chrono::__skip_mandatory_whitespace(__input);
+  __rule.__at = __parse_at(__input);
+  chrono::__skip_mandatory_whitespace(__input);
+  __rule.__save = __parse_save(__input);
+  chrono::__skip_mandatory_whitespace(__input);
+  __rule.__letters = chrono::__parse_letters(__input);
+  chrono::__skip_line(__input);
+}
+
+static void __parse_zone(tzdb& __tzdb, istream& __input) {
+  chrono::__skip_mandatory_whitespace(__input);
+  vector<__tz::__continuation>& __continuations =
+      __tzdb.zones.emplace_back(chrono::__parse_string(__input)).__continuations();
+  chrono::__skip_mandatory_whitespace(__input);
+
+  do {
+    // The first line must be valid, continuations are optional.
+    __continuations.emplace_back(__parse_continuation(__input));
+    chrono::__skip_line(__input);
+    chrono::__skip_optional_whitespace(__input);
+  } while (std::isdigit(__input.peek()) || __input.peek() == '-');
+}
+
+static void __parse_link(tzdb& __tzdb, istream& __input) {
+  chrono::__skip_mandatory_whitespace(__input);
+  string __target = chrono::__parse_string(__input);
+  chrono::__skip_mandatory_whitespace(__input);
+  string __name = chrono::__parse_string(__input);
+  chrono::__skip_line(__input);
+
+  __tzdb.links.emplace_back(std::move(__name), std::move(__target));
+}
+
+static void __parse_tzdata(tzdb& __db, istream& __input) {
+  while (true) {
+    int __c = std::tolower(__input.get());
+
+    switch (__c) {
+    case istream::traits_type::eof():
+      return;
+
+    case ' ':
+    case '\t':
+    case '\n':
+      break;
+
+    case '#':
+      chrono::__skip_line(__input);
+      break;
+
+    case 'r':
+      chrono::__skip(__input, "ule");
+      chrono::__parse_rule(__db, __input);
+      break;
+
+    case 'z':
+      chrono::__skip(__input, "one");
+      chrono::__parse_zone(__db, __input);
+      break;
+
+    case 'l':
+      chrono::__skip(__input, "link");
----------------
mordante wrote:

it's not. In the end I like to test with multiple real databases, especially for parsing to see whether they all pass. This also helps to catch things in the database that are contradict the specs.

https://github.com/llvm/llvm-project/pull/74928