Combine WorkspaceRcFileSearchPath and FindCandidateBlazercPaths and a…

…dd a test.

RELNOTES: None
PiperOrigin-RevId: 184865343

src/main/cpp/option_processor.cc

@@ -237,9 +237,9 @@ blaze_exit_code::ExitCode OptionProcessor::ParseOptions(
   // paths to the rc files. This list may contain duplicates.
   vector<string> candidate_blazerc_paths;
   if (use_master_blazerc) {
-    workspace_layout_->FindCandidateBlazercPaths(
-        workspace, cwd, cmd_line_->path_to_binary, cmd_line_->startup_args,
-        &candidate_blazerc_paths);
+    candidate_blazerc_paths =
+        workspace_layout_->FindCandidateBlazercPaths(
+            workspace, cwd, cmd_line_->path_to_binary, cmd_line_->startup_args);
   }
 
   string user_blazerc_path;

src/main/cpp/workspace_layout.cc

@@ -56,21 +56,6 @@ string WorkspaceLayout::GetPrettyWorkspaceName(
   return blaze_util::Basename(workspace);
 }
 
-static string FindDepotBlazerc(const blaze::WorkspaceLayout* workspace_layout,
-                               const string& workspace) {
-  // Package semantics are ignored here, but that's acceptable because
-  // blaze.blazerc is a configuration file.
-  vector<string> candidates;
-  workspace_layout->WorkspaceRcFileSearchPath(&candidates);
-  for (const auto& candidate : candidates) {
-    string blazerc = blaze_util::JoinPath(workspace, candidate);
-    if (blaze_util::CanReadFile(blazerc)) {
-      return blazerc;
-    }
-  }
-  return "";
-}
-
 static string FindAlongsideBinaryBlazerc(const string& cwd,
                                          const string& path_to_binary) {
   // TODO(b/32115171): This doesn't work on Windows. Fix this together with the
@@ -86,20 +71,16 @@ static string FindAlongsideBinaryBlazerc(const string& cwd,
   return "";
 }
 
-void WorkspaceLayout::FindCandidateBlazercPaths(
+vector<string> WorkspaceLayout::FindCandidateBlazercPaths(
     const string& workspace,
     const string& cwd,
     const string& path_to_binary,
-    const vector<string>& startup_args,
-    std::vector<string>* result) const {
-  result->push_back(FindDepotBlazerc(this, workspace));
-  result->push_back(FindAlongsideBinaryBlazerc(cwd, path_to_binary));
-  result->push_back(FindSystemWideBlazerc());
-}
-
-void WorkspaceLayout::WorkspaceRcFileSearchPath(
-    vector<string>* candidates) const {
-  candidates->push_back("tools/bazel.rc");
+    const vector<string>& startup_args) const {
+  return {
+    blaze_util::JoinPath(workspace, "tools/bazel.rc"),
+    FindAlongsideBinaryBlazerc(cwd, path_to_binary),
+    FindSystemWideBlazerc(),
+  };
 }
 
 bool WorkspaceLayout::WorkspaceRelativizeRcFilePath(const string &workspace,

src/main/cpp/workspace_layout.h

@@ -48,23 +48,19 @@ class WorkspaceLayout {
   // Returns if workspace is a valid build workspace.
   virtual bool InWorkspace(const std::string& workspace) const;
 
-  // Returns the candidate pathnames for the RC files.
-  virtual void FindCandidateBlazercPaths(
+  // Returns the candidate master RC file absolute paths.
+  // All readable files from the result will be used. Empty or nonexistant files
+  // will be ignored. It is ok if no usable candidate exists.
+  virtual std::vector<std::string> FindCandidateBlazercPaths(
       const std::string& workspace,
       const std::string& cwd,
       const std::string& path_to_binary,
-      const std::vector<std::string>& startup_args,
-      std::vector<std::string>* result) const;
-
-  // Returns the candidate pathnames for the RC file in the workspace,
-  // the first readable one of which will be chosen.
-  // It is ok if no usable candidate exists.
-  virtual void WorkspaceRcFileSearchPath(std::vector<std::string>* candidates)
-      const;
+      const std::vector<std::string>& startup_args) const;
 
   // Turn a %workspace%-relative import into its true name in the filesystem.
   // path_fragment is modified in place.
-  // Unlike WorkspaceRcFileSearchPath, it is an error if no import file exists.
+  // Unlike FindCandidateBlazercPaths, it is an error if no import file
+  // exists.
   virtual bool WorkspaceRelativizeRcFilePath(const std::string& workspace,
                                              std::string* path_fragment) const;
 

src/test/cpp/workspace_layout_test.cc

@@ -67,4 +67,31 @@ TEST_F(WorkspaceLayoutTest, GetWorkspace) {
   ASSERT_EQ(build_root_, workspace_layout_->GetWorkspace(cwd));
 }
 
+TEST_F(WorkspaceLayoutTest, FindCandidateBlazercPaths) {
+  const std::string binary_dir = blaze_util::JoinPath(build_root_, "bazeldir");
+  const std::string tools_dir = blaze_util::JoinPath(build_root_, "tools");
+  const std::string workspace_rc_path =
+      blaze_util::JoinPath(build_root_, "tools/bazel.rc");
+  const std::string binary_rc_path =
+      blaze_util::JoinPath(binary_dir, "bazel.bazelrc");
+  ASSERT_TRUE(blaze_util::MakeDirectories(binary_dir, 0755));
+  ASSERT_TRUE(blaze_util::MakeDirectories(tools_dir, 0755));
+  ASSERT_TRUE(blaze_util::WriteFile("", workspace_rc_path, 0755));
+  ASSERT_TRUE(blaze_util::WriteFile("", binary_rc_path, 0755));
+
+  std::vector<std::string> expected = {workspace_rc_path, binary_rc_path};
+  std::vector<std::string> actual =
+      workspace_layout_->FindCandidateBlazercPaths(
+          build_root_, build_root_, "bazeldir/bazel", {});
+  // The third entry is the system wide blazerc path, /etc/bazel.bazelrc, which
+  // we do not mock within this test because it is not within the sandbox. It
+  // may or may not exist on the system running the test, so we do not check for
+  // it.
+  // TODO(https://github.com/bazelbuild/bazel/issues/4502): Make the system-wide
+  // master bazelrc location configurable and add test coverage for it.
+  std::vector<std::string> actual_first_two_entries(actual.begin(),
+                                                    actual.begin() + 2);
+  ASSERT_EQ(expected, actual_first_two_entries);
+}
+
 }  // namespace blaze