Implement `gn analyze`.

tools/gn/analyzer_unittest.cc

+// Copyright 2016 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/analyzer.h"
+#include "tools/gn/build_settings.h"
+#include "tools/gn/builder.h"
+#include "tools/gn/loader.h"
+#include "tools/gn/settings.h"
+#include "tools/gn/source_file.h"
+
+
+namespace {
+
+class MockLoader : public Loader {
+ public:
+  MockLoader() {}
+
+  void Load(const SourceFile& file,
+            const LocationRange& origin,
+            const Label& toolchain_name) override {}
+  void ToolchainLoaded(const Toolchain* toolchain) override {}
+  Label GetDefaultToolchain() const override {
+    return Label(SourceDir("//tc/"), "default");
+  }
+  const Settings* GetToolchainSettings(const Label& label) const override {
+    return nullptr;
+  }
+
+ private:
+  ~MockLoader() override {}
+};
+
+class AnalyzerTest : public testing::Test {
+ public:
+  AnalyzerTest()
+      : loader_(new MockLoader),
+        builder_(loader_.get()),
+        settings_(&build_settings_, std::string()) {
+    build_settings_.SetBuildDir(SourceDir("//out/"));
+    settings_.set_toolchain_label(Label(SourceDir("//tc/"), "default"));
+    settings_.set_default_toolchain_label(settings_.toolchain_label());
+    tc_dir_ = settings_.toolchain_label().dir();
+    tc_name_ = settings_.toolchain_label().name();
+  }
+
+  Target* MakeTarget(const std::string dir,
+                     const std::string name,
+                     Target::OutputType type,
+                     const std::vector<std::string>& sources,
+                     const std::vector<Target*>& deps) {
+    Label lbl(SourceDir(dir), name, tc_dir_, tc_name_);
+    Target* target = new Target(&settings_, lbl);
+    target->set_output_type(type);
+    for (const auto& s : sources)
+      target->sources().push_back(SourceFile(s));
+    for (const auto* d : deps)
+      target->public_deps().push_back(LabelTargetPair(d));
+    builder_.ItemDefined(std::unique_ptr<Item>(target));
+    return target;
+  }
+
+  void AddSource(Target* a, std::string path) {}
+
+  void AddDep(Target* a, Target* b) {}
+
+  void SetUpABasicBuildGraph() {
+    std::vector<std::string> no_sources;
+    std::vector<Target*> no_deps;
+
+    // All of the targets below are owned by the builder, so none of them
+    // get leaked.
+
+    // Ignore the returned target since nothing depends on it.
+    MakeTarget("//", "a", Target::EXECUTABLE, {"//a.cc"}, no_deps);
+
+    Target* b =
+        MakeTarget("//d", "b", Target::SOURCE_SET, {"//d/b.cc"}, no_deps);
+
+    Target* b_unittests = MakeTarget("//d", "b_unittests", Target::EXECUTABLE,
+                                     {"//d/b_unittest.cc"}, {b});
+
+    Target* c = MakeTarget("//d", "c", Target::EXECUTABLE, {"//d/c.cc"}, {b});
+
+    Target* b_unittests_and_c =
+        MakeTarget("//d", "b_unittests_and_c", Target::GROUP, no_sources,
+                   {b_unittests, c});
+
+    Target* e =
+        MakeTarget("//d", "e", Target::EXECUTABLE, {"//d/e.cc"}, no_deps);
+
+    // Also ignore this returned target since nothing depends on it.
+    MakeTarget("//d", "d", Target::GROUP, no_sources, {b_unittests_and_c, e});
+  }
+
+  void RunBasicTest(const std::string& input,
+                    const std::string& expected_output) {
+    SetUpABasicBuildGraph();
+    Err err;
+    std::string actual_output = Analyzer(builder_).Analyze(input, &err);
+    EXPECT_EQ(err.has_error(), false);
+    EXPECT_EQ(expected_output, actual_output);
+  }
+
+ protected:
+  scoped_refptr<MockLoader> loader_;
+  Builder builder_;
+  BuildSettings build_settings_;
+  Settings settings_;
+  SourceDir tc_dir_;
+  std::string tc_name_;
+};
+
+}  // namespace
+
+// TODO: clean this up when raw string literals are allowed.
+
+TEST_F(AnalyzerTest, AllWasPruned) {
+  RunBasicTest(
+      "{"
+      "  \"files\": [ \"//d/b.cc\" ],"
+      "  \"compile_targets\": [ \"all\" ],"
+      "  \"test_targets\": [ ]"
+      "}",
+      "{"
+      "\"compile_targets\":[\"//d:b_unittests\",\"//d:c\"],"
+      "\"status\":\"Found dependency\","
+      "\"test_targets\":[]"
+      "}");
+}
+
+TEST_F(AnalyzerTest, NoDependency) {
+  RunBasicTest(
+      "{"
+      "  \"files\":[ \"//missing.cc\" ],"
+      "  \"compile_targets\": [ \"all\" ],"
+      "  \"test_targets\": [ \"//:a\" ]"
+      "}",
+      "{"
+      "\"compile_targets\":[],"
+      "\"status\":\"No dependency\","
+      "\"test_targets\":[]"
+      "}");
+}
+
+TEST_F(AnalyzerTest, NoFilesNoTargets) {
+  RunBasicTest(
+      "{"
+      "  \"files\": [],"
+      "  \"compile_targets\": [],"
+      "  \"test_targets\": []"
+      "}",
+      "{"
+      "\"compile_targets\":[],"
+      "\"status\":\"No dependency\","
+      "\"test_targets\":[]"
+      "}");
+}
+
+TEST_F(AnalyzerTest, OneTestTargetModified) {
+  RunBasicTest(
+      "{"
+      "  \"files\": [ \"//a.cc\" ],"
+      "  \"compile_targets\": [],"
+      "  \"test_targets\": [ \"//:a\" ]"
+      "}",
+      "{"
+      "\"compile_targets\":[],"
+      "\"status\":\"Found dependency\","
+      "\"test_targets\":[\"//:a\"]"
+      "}");
+}