1 files changed, 14 insertions, 3 deletions

diff --git a/ninja/src/deps_log.h b/ninja/src/deps_log.h
index de0fe639d14..cec0257ceff 100644
--- a/ninja/src/deps_log.h
+++ b/ninja/src/deps_log.h
@@ -50,9 +50,12 @@ struct State;
 /// A dependency list maps an output id to a list of input ids.
 ///
 /// Concretely, a record is:
-///    two bytes record length, high bit indicates record type
-///      (implies max record length 32k)
-///    path records contain just the string name of the path
+///    four bytes record length, high bit indicates record type
+///      (but max record sizes are capped at 512kB)
+///    path records contain the string name of the path, followed by up to 3
+///      padding bytes to align on 4 byte boundaries, followed by the
+///      one's complement of the expected index of the record (to detect
+///      concurrent writes of multiple ninja processes to the log).
 ///    dependency records are an array of 4-byte integers
 ///      [output path id, output path mtime, input path id, input path id...]
 ///      (The mtime is compared against the on-disk output path mtime
@@ -85,6 +88,14 @@ struct DepsLog {
   /// Rewrite the known log entries, throwing away old data.
   bool Recompact(const string& path, string* err);
 
+  /// Returns if the deps entry for a node is still reachable from the manifest.
+  ///
+  /// The deps log can contain deps entries for files that were built in the
+  /// past but are no longer part of the manifest.  This function returns if
+  /// this is the case for a given node.  This function is slow, don't call
+  /// it from code that runs on every build.
+  bool IsDepsEntryLiveFor(Node* node);
+
   /// Used for tests.
   const vector<Node*>& nodes() const { return nodes_; }
   const vector<Deps*>& deps() const { return deps_; }