Method LoadDepFile

src/graph.cc:642–705

};

bool ImplicitDepLoader::LoadDepFile(Edge* edge, const string& path,
                                    string* err) {
  METRIC_RECORD("depfile load");
  // Read depfile content.  Treat a missing depfile as empty.
  string content;
  switch (disk_interface_->ReadFile(path, &content, err)) {
  case DiskInterface::Okay:
    break;
  case DiskInterface::NotFound:
    err->clear();
    break;
  case DiskInterface::OtherError:
    *err = "loading '" + path + "': " + *err;
    return false;
  }
  // On a missing depfile: return false and empty *err.
  Node* first_output = edge->outputs_[0];
  if (content.empty()) {
    explanations_.Record(first_output, "depfile '%s' is missing", path.c_str());
    return false;
  }

  DepfileParser depfile(depfile_parser_options_
                        ? *depfile_parser_options_
                        : DepfileParserOptions());
  string depfile_err;
  if (!depfile.Parse(&content, &depfile_err)) {
    *err = path + ": " + depfile_err;
    return false;
  }

  if (depfile.outs_.empty()) {
    *err = path + ": no outputs declared";
    return false;
  }

  uint64_t unused;
  std::vector<StringPiece>::iterator primary_out = depfile.outs_.begin();
  CanonicalizePath(const_cast<char*>(primary_out->str_), &primary_out->len_,
                   &unused);

  // Check that this depfile matches the edge's output, if not return false to
  // mark the edge as dirty.
  StringPiece opath = StringPiece(first_output->path());
  if (opath != *primary_out) {
    explanations_.Record(first_output,
                         "expected depfile '%s' to mention '%s', got '%s'",
                         path.c_str(), first_output->path().c_str(),
                         primary_out->AsString().c_str());
    return false;
  }

  // Ensure that all mentioned outputs are outputs of the edge.
  for (std::vector<StringPiece>::iterator o = depfile.outs_.begin();
       o != depfile.outs_.end(); ++o) {
    matches m(o);
    if (std::find_if(edge->outputs_.begin(), edge->outputs_.end(), m) == edge->outputs_.end()) {
      *err = path + ": depfile mentions '" + o->AsString() + "' as an output, but no such output was declared";