GN: Use implicit dependency for binary input deps

tools/gn/ninja_target_writer.cc

 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "tools/gn/ninja_target_writer.h"
 
 #include <sstream>
 
 #include "base/files/file_util.h"
 #include "base/strings/string_util.h"
@@ skipping 147 matching lines @@
   // number before writing allows us to either skip writing the input deps
   // stamp or optimize it. Use pointers to avoid copies here.
   std::vector<const SourceFile*> input_deps_sources;
   input_deps_sources.reserve(32);
 
   // Actions get implicit dependencies on the script itself.
   if (target_->output_type() == Target::ACTION ||
       target_->output_type() == Target::ACTION_FOREACH)
     input_deps_sources.push_back(&target_->action_values().script());
 
-  // Input files.
-  for (const auto& input : target_->inputs())
-    input_deps_sources.push_back(&input);
+  // Input files are only considered for non-binary targets which use an
+  // implicit dependency instead.

[brettw, 2016/06/17 17:54:20]

Can you mentioned that the implicit dep in this case is handled separately by
the binary target writer?

[Petr Hosek, 2016/06/17 18:59:30]

Done.

+  if (!target_->IsBinary()) {
+    for (const auto& input : target_->inputs())
+      input_deps_sources.push_back(&input);
+  }
 
   // For an action (where we run a script only once) the sources are the same
   // as the inputs. For action_foreach, the sources will be operated on
   // separately so don't handle them here.
   if (target_->output_type() == Target::ACTION) {
     for (const auto& source : target_->sources())
       input_deps_sources.push_back(&source);
   }
 
   // ----------
@@ skipping 99 matching lines @@
        << GetNinjaRulePrefixForToolchain(settings_)
        << Toolchain::ToolTypeToName(Toolchain::TYPE_STAMP);
   path_output_.WriteFiles(out_, files);
 
   if (!order_only_deps.empty()) {
     out_ << " ||";
     path_output_.WriteFiles(out_, order_only_deps);
   }
   out_ << std::endl;
 }