Special-case paths that appear in libs by not prefixing them with -l.

tools/gn/target.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 "base/bind.h"
 #include "base/strings/string_util.h"
 #include "base/strings/stringprintf.h"
 #include "tools/gn/config_values_extractors.h"
@@ skipping 534 matching lines @@
   // Checks that any inputs or sources to this target that are in the build
   // directory are generated by a target that this one transitively depends on
   // in some way. We already guarantee that all generated files are written
   // to the build dir.
   //
   // See Scheduler::AddUnknownGeneratedInput's declaration for more.
   for (const SourceFile& file : sources_)
     CheckSourceGenerated(file);
   for (const SourceFile& file : inputs_)
     CheckSourceGenerated(file);
+  for (size_t i = 0; i < all_libs_.size(); i++) {
+    if (all_libs_[i].is_source_file())
+      CheckSourceGenerated(all_libs_[i].source_file());
+  }
 }
 
 void Target::CheckSourceGenerated(const SourceFile& source) const {
   if (!IsStringInOutputDir(settings()->build_settings()->build_dir(),
                            source.value()))
     return;  // Not in output dir, this is OK.
 
   // Tell the scheduler about unknown files. This will be noted for later so
   // the list of files written by the GN build itself (often response files)
   // can be filtered out of this list.
   OutputFile out_file(settings()->build_settings(), source);
   std::set<const Target*> seen_targets;
   if (!EnsureFileIsGeneratedByDependency(this, out_file, true, &seen_targets))
     g_scheduler->AddUnknownGeneratedInput(this, source);
 }