Allow .o files for GN generated inputs.

tools/gn/target_unittest.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/target.h"
 
 #include <utility>
 
 #include "testing/gtest/include/gtest/gtest.h"
 #include "tools/gn/build_settings.h"
@@ skipping 569 matching lines @@
   TestTarget existent_generator(setup, "//foo:existent_generator",
                                 Target::EXECUTABLE);
   existent_generator.sources().push_back(generated_file);
   EXPECT_TRUE(existent_generator.OnResolved(&err));
   scheduler.AddWrittenFile(generated_file);
 
   // Should be OK.
   EXPECT_TRUE(scheduler.GetUnknownGeneratedInputs().empty());
 }
 
+// Tests that intermediate object files generated by binary targets are also
+// considered generated for the purposes of input checking. Above, we tested
+// the failure cases for generated inputs, so here only test .o files that are
+// present.
+TEST(Target, ObjectGeneratedInputs) {
+  Scheduler scheduler;
+  TestWithScope setup;
+  Err err;
+
+  // This target compiles the source.
+  SourceFile source_file("//source.cc");
+  TestTarget source_generator(setup, "//:source_target", Target::SOURCE_SET);
+  source_generator.sources().push_back(source_file);
+  EXPECT_TRUE(source_generator.OnResolved(&err));
+
+  // This is the object file that the test toolchain generates for the source.
+  SourceFile object_file("//out/Debug/obj/source_target.source.o");
+
+  TestTarget final_target(setup, "//:final", Target::ACTION);
+  final_target.inputs().push_back(object_file);
+  EXPECT_TRUE(final_target.OnResolved(&err));
+
+  AssertSchedulerHasOneUnknownFileMatching(&final_target, object_file);
+}
+
 TEST(Target, ResolvePrecompiledHeaders) {
   TestWithScope setup;
   Err err;
 
   Target target(setup.settings(), Label(SourceDir("//foo/"), "bar"));
 
   // Target with no settings, no configs, should be a no-op.
   EXPECT_TRUE(target.ResolvePrecompiledHeaders(&err));
 
   // Config with PCH values.
@@ skipping 36 matching lines @@
       "\n"
       "From //foo:bar\n"
       "  header: pch.h\n"
       "  source: //pcs.cc\n"
       "\n"
       "From //foo:c2\n"
       "  header: pch2.h\n"
       "  source: //pcs2.cc",
       err.help_text());
 }