gn: Support build directories outside the source tree.

tools/gn/function_rebase_path_unittest.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 "build/build_config.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "tools/gn/functions.h"
 #include "tools/gn/parse_tree.h"
 #include "tools/gn/test_with_scope.h"
 
@@ skipping 60 matching lines @@
 #else
   setup.build_settings()->SetRootPath(base::FilePath("/source"));
   EXPECT_EQ("/source", RebaseOne(scope, ".", "", "//"));
   EXPECT_EQ("/source/", RebaseOne(scope, "//", "", "//"));
   EXPECT_EQ("/source/foo", RebaseOne(scope, "foo", "", "//"));
   EXPECT_EQ("/source/foo/", RebaseOne(scope, "foo/", "", "//"));
   EXPECT_EQ("/source/tools/gn/foo", RebaseOne(scope, "foo", "", "."));
 #endif
 }
 
+TEST(RebasePath, StringsSystemPaths) {
+  TestWithScope setup;
+  Scope* scope = setup.scope();
+
+#if defined(OS_WIN)
+  setup.build_settings()->SetBuildDir(SourceDir("C:/ssd/out/Debug"));
+  setup.build_settings()->SetRootPath(base::FilePath(L"C:/hdd/src"));
+
+  // Test system absolute to-dir.
+  EXPECT_EQ("../../ssd/out/Debug",
+            RebaseOne(scope, ".", "//", "C:/ssd/out/Debug"));
+  EXPECT_EQ("../../ssd/out/Debug/",
+            RebaseOne(scope, "./", "//", "C:/ssd/out/Debug"));
+  EXPECT_EQ("../../ssd/out/Debug/foo",
+            RebaseOne(scope, "foo", "//", "C:/ssd/out/Debug"));
+  EXPECT_EQ("../../ssd/out/Debug/foo/",
+            RebaseOne(scope, "foo/", "//", "C:/ssd/out/Debug"));
+
+  // Test system absolute from-dir.
+  EXPECT_EQ("../../../hdd/src",
+            RebaseOne(scope, ".", "C:/ssd/out/Debug", "//"));
+  EXPECT_EQ("../../../hdd/src/",
+            RebaseOne(scope, "./", "C:/ssd/out/Debug", "//"));
+  EXPECT_EQ("../../../hdd/src/foo",
+            RebaseOne(scope, "foo", "C:/ssd/out/Debug", "//"));
+  EXPECT_EQ("../../../hdd/src/foo/",
+            RebaseOne(scope, "foo/", "C:/ssd/out/Debug", "//"));
+#else
+  setup.build_settings()->SetBuildDir(SourceDir("/ssd/out/Debug"));
+  setup.build_settings()->SetRootPath(base::FilePath("/hdd/src"));
+
+  // Test system absolute to-dir.
+  EXPECT_EQ("../../ssd/out/Debug",
+            RebaseOne(scope, ".", "//", "/ssd/out/Debug"));
+  EXPECT_EQ("../../ssd/out/Debug/",
+            RebaseOne(scope, "./", "//", "/ssd/out/Debug"));
+  EXPECT_EQ("../../ssd/out/Debug/foo",
+            RebaseOne(scope, "foo", "//", "/ssd/out/Debug"));
+  EXPECT_EQ("../../ssd/out/Debug/foo/",
+            RebaseOne(scope, "foo/", "//", "/ssd/out/Debug"));
+
+  // Test system absolute from-dir.
+  EXPECT_EQ("../../../hdd/src",
+            RebaseOne(scope, ".", "/ssd/out/Debug", "//"));
+  EXPECT_EQ("../../../hdd/src/",
+            RebaseOne(scope, "./", "/ssd/out/Debug", "//"));
+  EXPECT_EQ("../../../hdd/src/foo",
+            RebaseOne(scope, "foo", "/ssd/out/Debug", "//"));
+  EXPECT_EQ("../../../hdd/src/foo/",
+            RebaseOne(scope, "foo/", "/ssd/out/Debug", "//"));
+#endif
+}
+
 // Test list input.
 TEST(RebasePath, List) {
   TestWithScope setup;
   setup.build_settings()->SetBuildDir(SourceDir("//out/Debug/"));
   setup.scope()->set_source_dir(SourceDir("//tools/gn/"));
 
   std::vector<Value> args;
   args.push_back(Value(NULL, Value::LIST));
   args[0].list_value().push_back(Value(NULL, "foo.txt"));
   args[0].list_value().push_back(Value(NULL, "bar.txt"));
@@ skipping 16 matching lines @@
   TestWithScope setup;
   setup.build_settings()->SetBuildDir(SourceDir("//out/Debug/"));
 
   // No arg input should issue an error.
   Err err;
   std::vector<Value> args;
   FunctionCallNode function;
   Value ret = functions::RunRebasePath(setup.scope(), &function, args, &err);
   EXPECT_TRUE(err.has_error());
 }