Refactor GN source expansions.

tools/gn/ninja_copy_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_copy_target_writer.h"
 
 #include "base/strings/string_util.h"
-#include "tools/gn/file_template.h"
 #include "tools/gn/string_utils.h"
+#include "tools/gn/substitution_list.h"
+#include "tools/gn/substitution_writer.h"
 
 NinjaCopyTargetWriter::NinjaCopyTargetWriter(const Target* target,
                                              const Toolchain* toolchain,
                                              std::ostream& out)
     : NinjaTargetWriter(target, toolchain, out) {
 }
 
 NinjaCopyTargetWriter::~NinjaCopyTargetWriter() {
 }
 
 void NinjaCopyTargetWriter::Run() {
-  CHECK(target_->action_values().outputs().size() == 1);
-  FileTemplate output_template = FileTemplate::GetForTargetOutputs(target_);
+  CHECK(target_->action_values().outputs().list().size() == 1);
+  const SubstitutionList& output_subst_list =
+      target_->action_values().outputs();
+  CHECK_EQ(1u, output_subst_list.list().size())
+      << "Should have one entry exactly.";
+  const SubstitutionPattern& output_subst = output_subst_list.list()[0];
 
   std::vector<OutputFile> output_files;
 
   std::string rule_prefix = helper_.GetRulePrefix(target_->settings());
 
   // Note that we don't write implicit deps for copy steps. "copy" only
   // depends on the output files themselves, rather than having includes
   // (the possibility of generated #includes is the main reason for implicit
   // dependencies).
   //
   // It would seem that specifying implicit dependencies on the deps of the
   // copy command would still be harmeless. But Chrome implements copy tools
   // as hard links (much faster) which don't change the timestamp. If the
   // ninja rule looks like this:
   //   output: copy input | foo.stamp
   // The copy will not make a new timestamp on the output file, but the
   // foo.stamp file generated from a previous step will have a new timestamp.
   // The copy rule will therefore look out-of-date to Ninja and the rule will
   // get rebuilt.
   //
   // If this copy is copying a generated file, not listing the implicit
   // dependency will be fine as long as the input to the copy is properly
   // listed as the output from the step that generated it.
   //
   // Moreover, doing this assumes that the copy step is always a simple
   // locally run command, so there is no need for a toolchain dependency.
   for (size_t i = 0; i < target_->sources().size(); i++) {
     const SourceFile& input_file = target_->sources()[i];
 
-    // Make the output file from the template.
-    std::vector<std::string> template_result;
-    output_template.Apply(input_file, &template_result);
-    CHECK(template_result.size() == 1);
-
-    // All output files should be in the build directory, so we can rebase
-    // them just by trimming the prefix.
-    OutputFile output_file(
-        RemovePrefix(template_result[0],
-                     settings_->build_settings()->build_dir().value()));
+    OutputFile output_file =
+        SubstitutionWriter::ApplyPatternToSourceAsOutputFile(
+            target_->settings(), output_subst, input_file);
     output_files.push_back(output_file);
 
     out_ << "build ";
     path_output_.WriteFile(out_, output_file);
     out_ << ": " << rule_prefix << "copy ";
     path_output_.WriteFile(out_, input_file);
     out_ << std::endl;
   }
 
   // Write out the rule for the target to copy all of them.
   out_ << std::endl << "build ";
   path_output_.WriteFile(out_, helper_.GetTargetOutputFile(target_));
   out_ << ": " << rule_prefix << "stamp";
   for (size_t i = 0; i < output_files.size(); i++) {
     out_ << " ";
     path_output_.WriteFile(out_, output_files[i]);
   }
   out_ << std::endl;
 }