Improve GN handling of directory templates.

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 86 matching lines @@
 // empty substring if none. For example "//foo/bar/" -> "bar".
 base::StringPiece FindLastDirComponent(const SourceDir& dir);
 
 // Verifies that the given string references a file inside of the given
 // directory. This is pretty stupid and doesn't handle "." and "..", etc.,
 // it is designed for a sanity check to keep people from writing output files
 // to the source directory accidentally.
 //
 // The originating value will be blamed in the error.
 //
+// Setting allow_templates indicates that the result will be put into a
+// FileTemplate and it will allow the strings to be prefixed with expansions
+// that would include the output path.
+//
 // If the file isn't in the dir, returns false and sets the error. Otherwise
 // returns true and leaves the error untouched.
 bool EnsureStringIsInOutputDir(const SourceDir& dir,
                                const std::string& str,
                                const Value& originating,
+                               bool allow_templates,
                                Err* err);
 
 // ----------------------------------------------------------------------------
 
 // Returns true if the input string is absolute. Double-slashes at the
 // beginning are treated as source-relative paths. On Windows, this handles
 // paths of both the native format: "C:/foo" and ours "/C:/foo"
 bool IsPathAbsolute(const base::StringPiece& path);
 
 // Given an absolute path, checks to see if is it is inside the source root.
@@ skipping 62 matching lines @@
 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_