gn: Support build directories outside the source tree.

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 <set>
 #include <sstream>
 
 #include "base/strings/string_util.h"
@@ skipping 85 matching lines @@
     out_ << kSubstitutionNinjaNames[SUBSTITUTION_DEFINES] << " =";
     RecursiveTargetConfigToStream<std::string>(
         target_, &ConfigValues::defines, DefineWriter(), out_);
     out_ << std::endl;
   }
 
   // Include directories.
   if (subst.used[SUBSTITUTION_INCLUDE_DIRS]) {
     out_ << kSubstitutionNinjaNames[SUBSTITUTION_INCLUDE_DIRS] << " =";
     PathOutput include_path_output(path_output_.current_dir(),
+                                   settings_->build_settings()->root_path(),
                                    ESCAPE_NINJA_COMMAND);
     RecursiveTargetConfigToStream<SourceDir>(
         target_, &ConfigValues::include_dirs,
         IncludeWriter(include_path_output), out_);
     out_ << std::endl;
   }
 
   // C flags and friends.
   EscapeOptions flag_escape_options = GetFlagOptions();
 #define WRITE_FLAGS(name, subst_enum) \
@@ skipping 27 matching lines @@
   std::vector<OutputFile> tool_outputs;  // Prevent reallocation in loop.
   for (const auto& source : target_->sources()) {
     Toolchain::ToolType tool_type = Toolchain::TYPE_NONE;
     if (!GetOutputFilesForSource(target_, source,
                                  &tool_type, &tool_outputs))
       continue;  // No output for this source.
 
     if (tool_type != Toolchain::TYPE_NONE) {
       out_ << "build";
       path_output_.WriteFiles(out_, tool_outputs);
+
       out_ << ": " << rule_prefix << Toolchain::ToolTypeToName(tool_type);
       out_ << " ";
       path_output_.WriteFile(out_, source);
       if (!input_dep.value().empty()) {
         // Write out the input dependencies as an order-only dependency. This
         // will cause Ninja to make sure the inputs are up-to-date before
         // compiling this source, but changes in the inputs deps won't cause
         // the file to be recompiled.
         //
         // This is important to prevent changes in unrelated actions that
@@ skipping 118 matching lines @@
   RecursiveTargetConfigStringsToStream(target_, &ConfigValues::ldflags,
                                        flag_options, out_);
 
   // Followed by library search paths that have been recursively pushed
   // through the dependency tree.
   const OrderedSet<SourceDir> all_lib_dirs = target_->all_lib_dirs();
   if (!all_lib_dirs.empty()) {
     // Since we're passing these on the command line to the linker and not
     // to Ninja, we need to do shell escaping.
     PathOutput lib_path_output(path_output_.current_dir(),
+                               settings_->build_settings()->root_path(),
                                ESCAPE_NINJA_COMMAND);
     for (size_t i = 0; i < all_lib_dirs.size(); i++) {
       out_ << " " << tool_->lib_dir_switch();
       lib_path_output.WriteDir(out_, all_lib_dirs[i],
                                PathOutput::DIR_NO_LAST_SLASH);
     }
   }
   out_ << std::endl;
 }
 
@@ skipping 167 matching lines @@
     return false;  // No tool for this file (it's a header file or something).
   const Tool* tool = target->toolchain()->GetTool(*computed_tool_type);
   if (!tool)
     return false;  // Tool does not apply for this toolchain.file.
 
   // Figure out what output(s) this compiler produces.
   SubstitutionWriter::ApplyListToCompilerAsOutputFile(
       target, source, tool->outputs(), outputs);
   return !outputs->empty();
 }