[6.4.0] Add formatted timestamp entries to volatile workspace status file.

site/en/docs/user-manual.md

@@ -1270,6 +1270,8 @@ The contract is:
     Bazel always outputs the following volatile keys:
       *   `BUILD_TIMESTAMP`: time of the build in seconds since the Unix Epoch (the value
         of `System.currentTimeMillis()` divided by a thousand)
+      *   `FORMATTED_DATE`: time of the build Formatted as
+        `yyyy MMM d HH mm ss EEE`(for example 2023 Jun 2 01 44 29 Fri) in UTC.
 
 On Linux/macOS you can pass `--workspace_status_command=/bin/true` to
 disable retrieving workspace status, because `true` does nothing, successfully (exits

src/main/java/com/google/devtools/build/lib/bazel/BazelWorkspaceStatusModule.java

@@ -62,6 +62,9 @@
 import java.io.IOException;
 import java.io.OutputStream;
 import java.nio.charset.StandardCharsets;
+import java.time.Instant;
+import java.time.ZoneOffset;
+import java.time.format.DateTimeFormatter;
 import java.util.Map;
 import java.util.TreeMap;
 import javax.annotation.Nullable;
@@ -80,6 +83,13 @@ static class BazelWorkspaceStatusAction extends WorkspaceStatusAction {
     private final String username;
     private final String hostname;
 
+    private static final DateTimeFormatter TIME_FORMAT =
+        DateTimeFormatter.ofPattern("yyyy MMM d HH mm ss EEE");
+
+    private static String format(long timestamp) {
+      return Instant.ofEpochMilli(timestamp).atZone(ZoneOffset.UTC).format(TIME_FORMAT);
+    }
+
     BazelWorkspaceStatusAction(
         Artifact stableStatus, Artifact volatileStatus, String username, String hostname) {
       super(
@@ -180,8 +190,9 @@ public ActionResult execute(ActionExecutionContext actionExecutionContext)
       stableMap.put(BuildInfo.BUILD_EMBED_LABEL, options.embedLabel);
       stableMap.put(BuildInfo.BUILD_HOST, hostname);
       stableMap.put(BuildInfo.BUILD_USER, username);
-      volatileMap.put(
-          BuildInfo.BUILD_TIMESTAMP, Long.toString(getCurrentTimeMillis(clientEnv) / 1000));
+      long currentTimeMillis = getCurrentTimeMillis(clientEnv);
+      volatileMap.put(BuildInfo.BUILD_TIMESTAMP, Long.toString(currentTimeMillis / 1000));
+      volatileMap.put("FORMATTED_DATE", format(currentTimeMillis / 1000 * 1000));
       try {
         Map<String, String> statusMap =
             parseWorkspaceStatus(getAdditionalWorkspaceStatus(options, actionExecutionContext));

src/test/shell/bazel/bazel_workspace_status_test.sh

@@ -190,6 +190,28 @@ EOF
   assert_contains "STABLE_NAME bob" bazel-genfiles/ao
   assert_contains "NUMBER 3" bazel-genfiles/ao
 
+  # Test that generated timestamp is the same as its formatted version.
+  volatile_file="bazel-out/volatile-status.txt"
+  bazel build --stamp //:a || fail "build failed"
+  assert_contains "BUILD_TIMESTAMP" $volatile_file
+  assert_contains "FORMATTED_DATE" $volatile_file
+  # Read key value pairs.
+  timestamp_key_value=$(sed "1q;d" $volatile_file)
+  formatted_timestamp_key_value=$(sed "2q;d" $volatile_file)
+  # Extract values of the formatted date and timestamp.
+  timestamp=${timestamp_key_value#* }
+  formatted_date=${formatted_timestamp_key_value#* }
+  if [[ $(uname -s) == "Darwin" ]]
+  then
+    timestamp_formatted_date=$(date -u -r "$timestamp" +'%Y %b %d %H %M %S %a')
+  else
+    timestamp_formatted_date=$(date -u -d "@$timestamp" +'%Y %b %d %H %M %S %a')
+  fi
+
+  if [[ $timestamp_formatted_date != $formatted_date ]]
+  then
+    fail "Timestamp formatted date: $timestamp_formatted_date differs from workspace module provided formatted date: $formatted_date"
+  fi
 }
 
 function test_env_var_in_workspace_status() {