Refactor depfile loading in preparation for the missingdeps tool

Extract an usable helper to load depfile dependencies without adding them
to the graph.

2 files changed, 15 insertions, 4 deletions

diff --git a/src/graph.cc b/src/graph.cc
index 78d0d49..90e8d08 100644
--- a/src/graph.cc
+++ b/src/graph.cc
@@ -588,13 +588,18 @@ bool ImplicitDepLoader::LoadDepFile(Edge* edge, const string& path,
     }
   }
 
+  return ProcessDepfileDeps(edge, &depfile.ins_, err);
+}
+
+bool ImplicitDepLoader::ProcessDepfileDeps(
+    Edge* edge, std::vector<StringPiece>* depfile_ins, std::string* err) {
   // Preallocate space in edge->inputs_ to be filled in below.
   vector<Node*>::iterator implicit_dep =
-      PreallocateSpace(edge, depfile.ins_.size());
+      PreallocateSpace(edge, depfile_ins->size());
 
   // Add all its in-edges.
-  for (vector<StringPiece>::iterator i = depfile.ins_.begin();
-       i != depfile.ins_.end(); ++i, ++implicit_dep) {
+  for (std::vector<StringPiece>::iterator i = depfile_ins->begin();
+       i != depfile_ins->end(); ++i, ++implicit_dep) {
     uint64_t slash_bits;
     if (!CanonicalizePath(const_cast<char*>(i->str_), &i->len_, &slash_bits,
                           err))
diff --git a/src/graph.h b/src/graph.h
index 8c51782..6756378 100644
--- a/src/graph.h
+++ b/src/graph.h
@@ -247,7 +247,13 @@ struct ImplicitDepLoader {
     return deps_log_;
   }
 
- private:
+ protected:
+  /// Process loaded implicit dependencies for \a edge and update the graph
+  /// @return false on error (without filling \a err if info is just missing)
+  virtual bool ProcessDepfileDeps(Edge* edge,
+                                  std::vector<StringPiece>* depfile_ins,
+                                  std::string* err);
+
   /// Load implicit dependencies for \a edge from a depfile attribute.
   /// @return false on error (without filling \a err if info is just missing).
   bool LoadDepFile(Edge* edge, const std::string& path, std::string* err);