Add GN function get_label_info

tools/gn/function_get_label_info_unittest.cc

Index: tools/gn/function_get_label_info_unittest.cc
diff --git a/tools/gn/function_get_label_info_unittest.cc b/tools/gn/function_get_label_info_unittest.cc
new file mode 100644
index 0000000000000000000000000000000000000000..0499dd61d0c420946e71898b970dbb28e6c99483
--- /dev/null
+++ b/tools/gn/function_get_label_info_unittest.cc
@@ -0,0 +1,92 @@
+// 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 {
+
+class GetLabelInfoTest : public testing::Test {
+ public:
+  GetLabelInfoTest() : testing::Test() {
+    setup_.scope()->set_source_dir(SourceDir("//src/foo/"));
+  }
+
+  // Convenience wrapper to call GetLabelInfo.
+  std::string Call(const std::string& label, const std::string& what) {
+    FunctionCallNode function;
+
+    std::vector<Value> args;
+    args.push_back(Value(NULL, label));
+    args.push_back(Value(NULL, what));
+
+    Err err;
+    Value result = functions::RunGetLabelInfo(setup_.scope(), &function,
+                                              args, &err);
+    if (err.has_error()) {
+      EXPECT_TRUE(result.type() == Value::NONE);
+      return std::string();
+    }
+    return result.string_value();
+  }
+
+ protected:
+  // Note: TestWithScope's default toolchain is "//toolchain:default" and
+  // output dir is "//out/Debug".
+  TestWithScope setup_;
+};
+
+}  // namespace
+
+TEST_F(GetLabelInfoTest, BadInput) {
+  EXPECT_EQ("", Call(":name", "incorrect_value"));
+  EXPECT_EQ("", Call("", "name"));
+}
+
+TEST_F(GetLabelInfoTest, Name) {
+  EXPECT_EQ("name", Call(":name", "name"));
+  EXPECT_EQ("name", Call("//foo/bar:name", "name"));
+}
+
+TEST_F(GetLabelInfoTest, Dir) {
+  EXPECT_EQ("//src/foo", Call(":name", "dir"));
+  EXPECT_EQ("//foo/bar", Call("//foo/bar:baz", "dir"));
+}
+
+TEST_F(GetLabelInfoTest, RootOutDir) {
+  EXPECT_EQ("//out/Debug", Call(":name", "root_out_dir"));
+  EXPECT_EQ("//out/Debug/random",
+            Call(":name(//toolchain:random)", "root_out_dir"));
+}
+
+TEST_F(GetLabelInfoTest, RootGetDir) {
+  EXPECT_EQ("//out/Debug/gen", Call(":name", "root_gen_dir"));
+  EXPECT_EQ("//out/Debug/random/gen",
+            Call(":name(//toolchain:random)", "root_gen_dir"));
+}
+
+TEST_F(GetLabelInfoTest, TargetOutDir) {
+  EXPECT_EQ("//out/Debug/obj/src/foo", Call(":name", "target_out_dir"));
+  EXPECT_EQ("//out/Debug", Call(":name", "root_out_dir"));
+}
+
+TEST_F(GetLabelInfoTest, LabelNoToolchain) {
+  EXPECT_EQ("//src/foo:name", Call(":name", "label_no_toolchain"));
+  EXPECT_EQ("//src/foo:name",
+            Call("//src/foo:name(//toolchain:random)", "label_no_toolchain"));
+}
+
+TEST_F(GetLabelInfoTest, LabelWithToolchain) {
+  EXPECT_EQ("//src/foo:name(//toolchain:default)",
+            Call(":name", "label_with_toolchain"));
+  EXPECT_EQ("//src/foo:name(//toolchain:random)",
+            Call(":name(//toolchain:random)", "label_with_toolchain"));
+}
+
+TEST_F(GetLabelInfoTest, Toolchain) {
+  EXPECT_EQ("//toolchain:default", Call(":name", "toolchain"));
+  EXPECT_EQ("//toolchain:random",
+            Call(":name(//toolchain:random)", "toolchain"));
+}