Add initial prototype for the GN meta-buildsystem.

tools/gn/label_unittest.cc

Index: tools/gn/label_unittest.cc
diff --git a/tools/gn/label_unittest.cc b/tools/gn/label_unittest.cc
new file mode 100644
index 0000000000000000000000000000000000000000..74eb3da9e80c0552c01fede46732d21153cba81a
--- /dev/null
+++ b/tools/gn/label_unittest.cc
@@ -0,0 +1,88 @@
+// 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 "testing/gtest/include/gtest/gtest.h"
+#include "tools/gn/err.h"
+#include "tools/gn/label.h"
+#include "tools/gn/value.h"
+
+namespace {
+
+struct ParseDepStringCase {
+  const char* cur_dir;
+  const char* str;
+  bool success;
+  const char* expected_dir;
+  const char* expected_name;
+  const char* expected_toolchain_dir;
+  const char* expected_toolchain_name;
+};
+
+}  // namespace
+
+TEST(Label, Resolve) {
+  ParseDepStringCase cases[] = {
+      // cur         input                        succ   expected dir          name    tc dir    tc name
+      { "//chrome/", "",                          false, "",                   "",     "",       "" },
+      { "//chrome/", "/",                         false, "",                   "",     "",       "" },
+      { "//chrome/", ":",                         false, "",                   "",     "",       "" },
+      { "//chrome/", "/:",                        false, "",                   "",     "",       "" },
+      { "//chrome/", "blah",                      true,  "//chrome/blah/",     "blah", "//t/",   "d" },
+      { "//chrome/", "blah:bar",                  true,  "//chrome/blah/",     "bar",  "//t/",   "d" },
+      // No single-leading slash.
+      { "//chrome/", "/chrome:bar",               false, "",                   "",     "",       "" },
+      // No trailing slash.
+      { "//chrome/", "/chrome/:bar",              false, "",                   "",     "",       "" },
+      // Refers to root dir.
+      { "//chrome/", "//:bar",                    true,  "//",                 "bar",  "//t/",   "d" },
+      // Implicit directory
+      { "//chrome/", ":bar",                      true,  "//chrome/",          "bar",  "//t/",   "d" },
+      { "//chrome/renderer/", ":bar",             true,  "//chrome/renderer/", "bar",  "//t/",   "d" },
+      // Implicit names.
+      { "//chrome/", "//base",                    true,  "//base/",            "base", "//t/",   "d" },
+      { "//chrome/", "//base/i18n",               true,  "//base/i18n/",       "i18n", "//t/",   "d" },
+      { "//chrome/", "//base/i18n:foo",           true,  "//base/i18n/",       "foo",  "//t/",   "d" },
+      // Toolchain parsing.
+      { "//chrome/", "//chrome:bar(//t:n)",       true,  "//chrome/",          "bar",  "//t/",   "n" },
+      { "//chrome/", "//chrome:bar(//t)",         true,  "//chrome/",          "bar",  "//t/",   "t" },
+      { "//chrome/", "//chrome:bar(//t:)",        true,  "//chrome/",          "bar",  "//t/",   "t" },
+      { "//chrome/", "//chrome:bar()",            true,  "//chrome/",          "bar",  "//t/",   "d" },
+      { "//chrome/", "//chrome:bar(foo)",         true,  "//chrome/",          "bar",  "//chrome/foo/", "foo" },
+      { "//chrome/", "//chrome:bar(:foo)",        true,  "//chrome/",          "bar",  "//chrome/",     "foo" },
+      // TODO(brettw) it might be nice to make this an error:
+      //{ "//chrome/", "//chrome:bar())",           false, "",                   "",     "",       "" },
+      { "//chrome/", "//chrome:bar(//t:bar(tc))", false, "",                   "",     "",       "" },
+      { "//chrome/", "//chrome:bar(()",           false, "",                   "",     "",       "" },
+      { "//chrome/", "(t:b)",                     false, "",                   "",     "",       "" },
+      { "//chrome/", ":bar(//t/b)",               true,  "//chrome/",          "bar",  "//t/b/", "b" },
+      { "//chrome/", ":bar(/t/b)",                false, "",                   "",     "",       "" },
+      { "//chrome/", ":bar(t/b)",                 true,  "//chrome/",          "bar",  "//chrome/t/b/", "b" },
+  };
+
+  Label default_toolchain(SourceDir("//t/"), "d",
+                          SourceDir(), std::string());
+
+  for (size_t i = 0; i < ARRAYSIZE_UNSAFE(cases); i++) {
+    const ParseDepStringCase& cur = cases[i];
+
+    std::string location, name;
+    Err err;
+    Value v(NULL, Value::STRING);
+    v.string_value() = cur.str;
+    Label result =
+        Label::Resolve(SourceDir(cur.cur_dir), default_toolchain, v, &err);
+    EXPECT_EQ(cur.success, !err.has_error()) << i << " " << cur.str;
+    if (!err.has_error() && cur.success) {
+      EXPECT_EQ(cur.expected_dir, result.dir().value())
+          << i << " " << cur.str;
+      EXPECT_EQ(cur.expected_name, result.name())
+          << i << " " << cur.str;
+      EXPECT_EQ(cur.expected_toolchain_dir,
+                result.toolchain_dir().value())
+          << i << " " << cur.str;
+      EXPECT_EQ(cur.expected_toolchain_name, result.toolchain_name())
+          << i << " " << cur.str;
+    }
+  }
+}