GN: Don't write ldflags and libs when unneeded.

tools/gn/ninja_binary_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_binary_target_writer.h"
 
 #include <stddef.h>
 #include <string.h>
 
 #include <cstring>
@@ skipping 761 matching lines @@
   // should also have been collected via the input deps stamp that each source
   // file has for an order-only dependency, and since this target depends on
   // the sources, there is already an implicit order-only dependency. However,
   // it's extra work to separate these out and there's no disadvantage to
   // listing them again.
   WriteOrderOnlyDependencies(non_linkable_deps);
 
   // End of the link "build" line.
   out_ << std::endl;
 
-  // These go in the inner scope of the link line.
-  WriteLinkerFlags(optional_def_file);
-
-  WriteLibs();
+  // The remaining things go in the inner scope of the link line.
+  if (target_->output_type() == Target::EXECUTABLE ||
+      target_->output_type() == Target::SHARED_LIBRARY ||
+      target_->output_type() == Target::LOADABLE_MODULE) {
+    WriteLinkerFlags(optional_def_file);
+    WriteLibs();
+  }
   WriteOutputExtension();
   WriteSolibs(solibs);
 }
 
 void NinjaBinaryTargetWriter::WriteLinkerFlags(
     const SourceFile* optional_def_file) {
   out_ << "  ldflags =";
 
   // First the ldflags from the target and its config.
   EscapeOptions flag_options = GetFlagOptions();
@@ skipping 205 matching lines @@
           "\n"
           "In the latter case, either rename one of the files or move one of\n"
           "the sources to a separate source_set to avoid them both being in\n"
           "the same target.");
       g_scheduler->FailWithError(err);
       return false;
     }
   }
   return true;
 }