Add directory extraction to GN path handling.

tools/gn/function_get_path_info_unittest.cc

 // Copyright 2014 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 "testing/gtest/include/gtest/gtest.h"
 #include "tools/gn/functions.h"
 #include "tools/gn/test_with_scope.h"
 
 namespace {
 
@@ skipping 69 matching lines @@
   EXPECT_EQ("//src/foo/foo/bar.txt", Call("foo/bar.txt", "abspath"));
   EXPECT_EQ("//src/foo/bar.txt", Call("bar.txt", "abspath"));
   EXPECT_EQ("//src/foo/bar/", Call("bar/", "abspath"));
   EXPECT_EQ("//foo", Call("//foo", "abspath"));
   EXPECT_EQ("//foo/", Call("//foo/", "abspath"));
   EXPECT_EQ("//", Call("//", "abspath"));
   EXPECT_EQ("/foo", Call("/foo", "abspath"));
   EXPECT_EQ("/foo/", Call("/foo/", "abspath"));
   EXPECT_EQ("/", Call("/", "abspath"));
 }
+
+// Note build dir is "//out/Debug/".
+TEST_F(GetPathInfoTest, OutDir) {
+  EXPECT_EQ("//out/Debug/obj/src/foo/foo", Call("foo/bar.txt", "out_dir"));
+  EXPECT_EQ("//out/Debug/obj/src/foo/bar", Call("bar/", "out_dir"));
+  EXPECT_EQ("//out/Debug/obj/src/foo", Call(".", "out_dir"));
+  EXPECT_EQ("//out/Debug/obj/src/foo", Call("bar", "out_dir"));
+  EXPECT_EQ("//out/Debug/obj/foo", Call("//foo/bar.txt", "out_dir"));
+  // System paths go into the root obj directory.
+  EXPECT_EQ("//out/Debug/obj", Call("/foo/bar.txt", "out_dir"));
+}
+
+// Note build dir is "//out/Debug/".
+TEST_F(GetPathInfoTest, GenDir) {
+  EXPECT_EQ("//out/Debug/gen/src/foo/foo", Call("foo/bar.txt", "gen_dir"));
+  EXPECT_EQ("//out/Debug/gen/src/foo/bar", Call("bar/", "gen_dir"));
+  EXPECT_EQ("//out/Debug/gen/src/foo", Call(".", "gen_dir"));
+  EXPECT_EQ("//out/Debug/gen/src/foo", Call("bar", "gen_dir"));
+  EXPECT_EQ("//out/Debug/gen/foo", Call("//foo/bar.txt", "gen_dir"));
+  // System paths go into the root obj directory.
+  EXPECT_EQ("//out/Debug/gen", Call("/foo/bar.txt", "gen_dir"));
+}