Reduce input dependencies in GN.

tools/gn/ninja_target_writer_unittest.cc

 // Copyright 2014 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 <sstream>
 
 #include "testing/gtest/include/gtest/gtest.h"
 #include "tools/gn/ninja_target_writer.h"
 #include "tools/gn/target.h"
 #include "tools/gn/test_with_scope.h"
 
 namespace {
 
 class TestingNinjaTargetWriter : public NinjaTargetWriter {
  public:
   TestingNinjaTargetWriter(const Target* target,
                            const Toolchain* toolchain,
                            std::ostream& out)
       : NinjaTargetWriter(target, out) {
   }
 
   virtual void Run() OVERRIDE {}
 
   // Make this public so the test can call it.
-  std::string WriteInputDepsStampAndGetDep(
+  OutputFile WriteInputDepsStampAndGetDep(
       const std::vector<const Target*>& extra_hard_deps) {
     return NinjaTargetWriter::WriteInputDepsStampAndGetDep(extra_hard_deps);
   }
 };
 
 }  // namespace
 
 TEST(NinjaTargetWriter, WriteInputDepsStampAndGetDep) {
   TestWithScope setup;
 
@@ skipping 22 matching lines @@
   action.deps().push_back(LabelTargetPair(&target));
 
   base_target.OnResolved();
   target.OnResolved();
   action.OnResolved();
 
   // Input deps for the base (should be only the script itself).
   {
     std::ostringstream stream;
     TestingNinjaTargetWriter writer(&base_target, setup.toolchain(), stream);
-    std::string dep =
+    OutputFile dep =
         writer.WriteInputDepsStampAndGetDep(std::vector<const Target*>());
 
-    EXPECT_EQ(" | obj/foo/base.inputdeps.stamp", dep);
+    EXPECT_EQ("obj/foo/base.inputdeps.stamp", dep.value());
     EXPECT_EQ("build obj/foo/base.inputdeps.stamp: stamp "
                   "../../foo/script.py\n",
               stream.str());
   }
 
   // Input deps for the target (should depend on the base).
   {
     std::ostringstream stream;
     TestingNinjaTargetWriter writer(&target, setup.toolchain(), stream);
-    std::string dep =
+    OutputFile dep =
         writer.WriteInputDepsStampAndGetDep(std::vector<const Target*>());
 
-    EXPECT_EQ(" | obj/foo/target.inputdeps.stamp", dep);
+    EXPECT_EQ("obj/foo/target.inputdeps.stamp", dep.value());
     EXPECT_EQ("build obj/foo/target.inputdeps.stamp: stamp "
                   "../../foo/input.txt obj/foo/base.stamp\n",
               stream.str());
   }
 
   // Input deps for action which should depend on the base since its a hard dep
   // that is a (indirect) dependency, as well as the the action source.
   {
     std::ostringstream stream;
     TestingNinjaTargetWriter writer(&action, setup.toolchain(), stream);
-    std::string dep =
+    OutputFile dep =
         writer.WriteInputDepsStampAndGetDep(std::vector<const Target*>());
 
-    EXPECT_EQ(" | obj/foo/action.inputdeps.stamp", dep);
+    EXPECT_EQ("obj/foo/action.inputdeps.stamp", dep.value());
     EXPECT_EQ("build obj/foo/action.inputdeps.stamp: stamp ../../foo/script.py "
                   "../../foo/action_source.txt obj/foo/base.stamp\n",
               stream.str());
   }
 }
 
 // Tests WriteInputDepsStampAndGetDep when toolchain deps are present.
 TEST(NinjaTargetWriter, WriteInputDepsStampAndGetDepWithToolchainDeps) {
   TestWithScope setup;
 
   // Toolchain dependency. Here we make a target in the same toolchain for
   // simplicity, but in real life (using the Builder) this would be rejected
   // because it would be a circular dependency (the target depends on its
   // toolchain, and the toolchain depends on this target).
   Target toolchain_dep_target(setup.settings(),
                               Label(SourceDir("//foo/"), "setup"));
   toolchain_dep_target.set_output_type(Target::ACTION);
   toolchain_dep_target.SetToolchain(setup.toolchain());
   toolchain_dep_target.OnResolved();
   setup.toolchain()->deps().push_back(LabelTargetPair(&toolchain_dep_target));
 
   // Make a binary target
   Target target(setup.settings(), Label(SourceDir("//foo/"), "target"));
   target.set_output_type(Target::EXECUTABLE);
   target.SetToolchain(setup.toolchain());
   target.OnResolved();
 
   std::ostringstream stream;
   TestingNinjaTargetWriter writer(&target, setup.toolchain(), stream);
-  std::string dep =
+  OutputFile dep =
       writer.WriteInputDepsStampAndGetDep(std::vector<const Target*>());
 
-  EXPECT_EQ(" | obj/foo/target.inputdeps.stamp", dep);
+  EXPECT_EQ("obj/foo/target.inputdeps.stamp", dep.value());
   EXPECT_EQ("build obj/foo/target.inputdeps.stamp: stamp "
                 "obj/foo/setup.stamp\n",
             stream.str());
 }