GN: Change gen command syntax, support relative dirs.

tools/gn/filesystem_utils.h

 // 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.
 
 #ifndef TOOLS_GN_FILESYSTEM_UTILS_H_
 #define TOOLS_GN_FILESYSTEM_UTILS_H_
 
 #include <string>
 
 #include "base/files/file_path.h"
@@ skipping 127 matching lines @@
 std::string RebaseSourceAbsolutePath(const std::string& input,
                                      const SourceDir& dest_dir);
 
 // Returns the given directory with no terminating slash at the end, such that
 // appending a slash and more stuff will produce a valid path.
 //
 // If the directory refers to either the source or system root, we'll append
 // a "." so this remains valid.
 std::string DirectoryWithNoLastSlash(const SourceDir& dir);
 
+// Returns the "best" SourceDir representing the given path. If it's inside the
+// given source_root, a source-relative directory will be returned (e.g.
+// "//foo/bar.cc". If it's outside of the source root, a system-absolute
+// directory will be returned.
+SourceDir SourceDirForPath(const base::FilePath& source_root,
+                           const base::FilePath& path);
+
+// Like SourceDirForPath but returns the SourceDir representing the current
+// directory.
+SourceDir SourceDirForCurrentDirectory(const base::FilePath& source_root);
+
 // -----------------------------------------------------------------------------
 
 // These functions return the various flavors of output and gen directories.
 SourceDir GetToolchainOutputDir(const Settings* settings);
 SourceDir GetToolchainGenDir(const Settings* settings);
 SourceDir GetOutputDirForSourceDir(const Settings* settings,
                                    const SourceDir& source_dir);
 SourceDir GetGenDirForSourceDir(const Settings* settings,
                                 const SourceDir& source_dir);
 SourceDir GetTargetOutputDir(const Target* target);
 SourceDir GetTargetGenDir(const Target* target);
 SourceDir GetCurrentOutputDir(const Scope* scope);
 SourceDir GetCurrentGenDir(const Scope* scope);
 
 #endif  // TOOLS_GN_FILESYSTEM_UTILS_H_