Implement tracking of BUILD.gn files used to define target, toolchain or

tools/gn/analyzer_unittest.cc

Index: tools/gn/analyzer_unittest.cc
diff --git a/tools/gn/analyzer_unittest.cc b/tools/gn/analyzer_unittest.cc
index a3c8d5becb7b31b6a0270d5d87139697ac8ad33a..3a82ceaf601d4a68832d1e4a806b78a9a7ad5974 100644
--- a/tools/gn/analyzer_unittest.cc
+++ b/tools/gn/analyzer_unittest.cc
@@ -49,9 +49,13 @@ class AnalyzerTest : public testing::Test {
                      const std::string name,
                      Target::OutputType type,
                      const std::vector<std::string>& sources,
-                     const std::vector<Target*>& deps) {
+                     const std::vector<Target*>& deps,
+                     const std::vector<std::string>& gn_files) {
     Label lbl(SourceDir(dir), name, tc_dir_, tc_name_);
-    Target* target = new Target(&settings_, lbl);
+    std::set<uint32_t> source_files_hashes;
+    for (const auto& gn : gn_files)
+      source_files_hashes.insert(base::Hash(gn));
+    Target* target = new Target(&settings_, lbl, source_files_hashes);
     target->set_output_type(type);
     for (const auto& s : sources)
       target->sources().push_back(SourceFile(s));
@@ -73,25 +77,29 @@ class AnalyzerTest : public testing::Test {
     // get leaked.
 
     // Ignore the returned target since nothing depends on it.
-    MakeTarget("//", "a", Target::EXECUTABLE, {"//a.cc"}, no_deps);
+    MakeTarget("//", "a", Target::EXECUTABLE, {"//a.cc"}, no_deps,
+               {"//BUILD.gn", "//features.gni"});
 
-    Target* b =
-        MakeTarget("//d", "b", Target::SOURCE_SET, {"//d/b.cc"}, no_deps);
+    Target* b = MakeTarget("//d", "b", Target::SOURCE_SET, {"//d/b.cc"},
+                           no_deps, {"//d/BUILD.gn"});
 
-    Target* b_unittests = MakeTarget("//d", "b_unittests", Target::EXECUTABLE,
-                                     {"//d/b_unittest.cc"}, {b});
+    Target* b_unittests =
+        MakeTarget("//d", "b_unittests", Target::EXECUTABLE,
+                   {"//d/b_unittest.cc"}, {b}, {"//d/BUILD.gn"});
 
-    Target* c = MakeTarget("//d", "c", Target::EXECUTABLE, {"//d/c.cc"}, {b});
+    Target* c = MakeTarget("//d", "c", Target::EXECUTABLE, {"//d/c.cc"}, {b},
+                           {"//d/BUILD.gn"});
 
     Target* b_unittests_and_c =
         MakeTarget("//d", "b_unittests_and_c", Target::GROUP, no_sources,
-                   {b_unittests, c});
+                   {b_unittests, c}, {"//d/BUILD.gn"});
 
-    Target* e =
-        MakeTarget("//d", "e", Target::EXECUTABLE, {"//d/e.cc"}, no_deps);
+    Target* e = MakeTarget("//d", "e", Target::EXECUTABLE, {"//d/e.cc"},
+                           no_deps, {"//d/BUILD.gn"});
 
     // Also ignore this returned target since nothing depends on it.
-    MakeTarget("//d", "d", Target::GROUP, no_sources, {b_unittests_and_c, e});
+    MakeTarget("//d", "d", Target::GROUP, no_sources, {b_unittests_and_c, e},
+               {"//d/BUILD.gn"});
   }
 
   void RunBasicTest(const std::string& input,
@@ -201,13 +209,10 @@ TEST_F(AnalyzerTest, WrongInputFields) {
       "}");
 }
 
-TEST_F(AnalyzerTest, BuildFilesWereModified) {
-  // This tests that if a build file is modified, we bail out early with
-  // "Found dependency (all)" error since we can't handle changes to
-  // build files yet (crbug.com/555273).
+TEST_F(AnalyzerTest, DotGnFileWasModified) {
   RunBasicTest(
       "{"
-      "  \"files\": [ \"//a.cc\", \"//BUILD.gn\" ],"
+      "  \"files\": [ \"//.gn\" ],"
       "  \"additional_compile_targets\": [],"
       "  \"test_targets\": [ \"//:a\" ]"
       "}",
@@ -218,13 +223,10 @@ TEST_F(AnalyzerTest, BuildFilesWereModified) {
       "}");
 }
 
-TEST_F(AnalyzerTest, BuildFilesWereModifiedAndCompilingAll) {
-  // This tests that if a build file is modified, we bail out early with
-  // "Found dependency (all)" error since we can't handle changes to
-  // build files yet (crbug.com/555273).
+TEST_F(AnalyzerTest, DotGnFileWasModifiedAndCompilingAll) {
   RunBasicTest(
       "{"
-      "  \"files\": [ \"//a.cc\", \"//BUILD.gn\" ],"
+      "  \"files\": [ \"//.gn\" ],"
       "  \"additional_compile_targets\": [ \"all\" ],"
       "  \"test_targets\": [ \"//:a\" ]"
       "}",
@@ -234,3 +236,45 @@ TEST_F(AnalyzerTest, BuildFilesWereModifiedAndCompilingAll) {
       "\"test_targets\":[\"//:a\"]"
       "}");
 }
+
+TEST_F(AnalyzerTest, BuildFileWasModified) {
+  RunBasicTest(
+      "{"
+      "  \"files\": [ \"//BUILD.gn\" ],"
+      "  \"additional_compile_targets\": [],"
+      "  \"test_targets\": [ \"//:a\" ]"
+      "}",
+      "{"
+      "\"compile_targets\":[],"
+      "\"status\":\"Found dependency\","
+      "\"test_targets\":[\"//:a\"]"
+      "}");
+}
+
+TEST_F(AnalyzerTest, BuildFileWasModifiedAndCompilingAll) {
+  RunBasicTest(
+      "{"
+      "  \"files\": [ \"//BUILD.gn\" ],"
+      "  \"additional_compile_targets\": [ \"all\" ],"
+      "  \"test_targets\": [ \"//:a\" ]"
+      "}",
+      "{"
+      "\"compile_targets\":[\"//:a\"],"
+      "\"status\":\"Found dependency\","
+      "\"test_targets\":[\"//:a\"]"
+      "}");
+}
+
+TEST_F(AnalyzerTest, UnnededBuildFileWasModified) {
+  RunBasicTest(
+      "{"
+      "  \"files\": [ \"//BUILD.gn\" ],"
+      "  \"additional_compile_targets\": [],"
+      "  \"test_targets\": [ \"//d:b_unittests\" ]"
+      "}",
+      "{"
+      "\"compile_targets\":[],"
+      "\"status\":\"No dependency\","
+      "\"test_targets\":[]"
+      "}");
+}