1 files changed, 77 insertions, 0 deletions
diff --git a/src/time/tzdata/generate_zipdata.go b/src/time/tzdata/generate_zipdata.go
new file mode 100644
index 0000000..653577c
--- /dev/null
+++ b/src/time/tzdata/generate_zipdata.go
@@ -0,0 +1,77 @@
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build ignore
+
+// This program generates zipdata.go from $GOROOT/lib/time/zoneinfo.zip.
+package main
+
+import (
+	"bufio"
+	"fmt"
+	"os"
+	"strconv"
+)
+
+// header is put at the start of the generated file.
+// The string addition avoids this file (generate_zipdata.go) from
+// matching the "generated file" regexp.
+const header = `// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+` + `// Code generated by generate_zipdata. DO NOT EDIT.
+
+// This file contains an embedded zip archive that contains time zone
+// files compiled using the code and data maintained as part of the
+// IANA Time Zone Database.
+// The IANA asserts that the data is in the public domain.
+
+// For more information, see
+// https://www.iana.org/time-zones
+// ftp://ftp.iana.org/tz/code/tz-link.html
+// https://datatracker.ietf.org/doc/html/rfc6557
+
+package tzdata
+
+const zipdata = `
+
+func main() {
+	// We should be run in the $GOROOT/src/time/tzdata directory.
+	data, err := os.ReadFile("../../../lib/time/zoneinfo.zip")
+	if err != nil {
+		die("cannot find zoneinfo.zip file: %v", err)
+	}
+
+	of, err := os.Create("zipdata.go")
+	if err != nil {
+		die("%v", err)
+	}
+
+	buf := bufio.NewWriter(of)
+	buf.WriteString(header)
+
+	ds := string(data)
+	i := 0
+	const chunk = 60
+	for ; i+chunk < len(data); i += chunk {
+		if i > 0 {
+			buf.WriteRune('\t')
+		}
+		fmt.Fprintf(buf, "%s +\n", strconv.Quote(ds[i:i+chunk]))
+	}
+	fmt.Fprintf(buf, "\t%s\n", strconv.Quote(ds[i:]))
+
+	if err := buf.Flush(); err != nil {
+		die("error writing to zipdata.go: %v", err)
+	}
+	if err := of.Close(); err != nil {
+		die("error closing zipdata.go: %v", err)
+	}
+}
+
+func die(format string, args ...any) {
+	fmt.Fprintf(os.Stderr, format+"\n", args...)
+	os.Exit(1)
+}