[RTS] Add back in RTS support to GNI

- Add use_rts bool flag to ensure that a .filter
file exists or creates a dummy file while waiting
for the file to be written.

RTS = Regression Test Selection
Re-land of https://crrev.com/c/4859614

Bug: 375000947
Change-Id: I425e0891ac895ae043855e0372be8a0e43a96f0f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5954865
Reviewed-by: Dirk Pranke <dpranke@google.com>
Reviewed-by: Struan Shrimpton <sshrimp@google.com>
Commit-Queue: Tony Seaward <seawardt@google.com>
Cr-Commit-Position: refs/heads/main@{#1374746}

build/add_rts_filters.py

@@ -0,0 +1,53 @@
+#!/usr/bin/env python3
+# Copyright 2024 The Chromium Authors
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+"""Creates a dummy RTS filter file if a real ones do not exist yet.
+  Real filter files are generated for suites with skippable tests.
+  Not every test suite will have filter data to use and therefore
+  no filter file will be created. This ensures that a file exists
+  to avoid file not found errors. The files will contain no skippable
+  tests, so there is no effect.
+
+  Implementation uses try / except because the filter files are written
+  relatively close to when this code creates the dummy files.
+
+  The following type of implementation would have a race condition:
+  if not os.path.isfile(filter_file):
+    open(filter_file, 'w') as fp:
+      fp.write('*')
+"""
+import errno
+import os
+import sys
+
+
+def main():
+  filter_file = sys.argv[1]
+  # '*' is a dummy that means run everything
+  write_filter_file(filter_file, '*')
+
+
+def write_filter_file(filter_file, filter_string):
+  directory = os.path.dirname(filter_file)
+  try:
+    os.makedirs(directory)
+  except OSError as err:
+    if err.errno == errno.EEXIST:
+      pass
+    else:
+      raise
+  try:
+    fp = os.open(filter_file, os.O_CREAT | os.O_EXCL | os.O_WRONLY)
+  except OSError as err:
+    if err.errno == errno.EEXIST:
+      pass
+    else:
+      raise
+  else:
+    with os.fdopen(fp, 'w') as file_obj:
+      file_obj.write(filter_string)
+
+
+if __name__ == '__main__':
+  sys.exit(main())

build/config/android/rules.gni

@@ -6,6 +6,7 @@ import("//build/config/android/abi.gni")
 import("//build/config/android/copy_ex.gni")
 import("//build/config/chrome_build.gni")
 import("//build/config/clang/clang.gni")
+import("//build/config/rts.gni")
 import("//build/config/sanitizers/sanitizers.gni")
 import("//build_overrides/build.gni")
 
@@ -3629,6 +3630,14 @@ if (!is_robolectric && enable_java_templates) {
   #     apk_under_test: ":bar"
   #   }
   template("instrumentation_test_runner") {
+    if (use_rts) {
+      action("${invoker.target_name}__rts_filters") {
+        script = "//build/add_rts_filters.py"
+        rts_file = "${root_build_dir}/gen/rts/${invoker.target_name}.filter"
+        args = [ rebase_path(rts_file, root_build_dir) ]
+        outputs = [ rts_file ]
+      }
+    }
     _incremental_apk = !(defined(invoker.never_incremental) &&
                          invoker.never_incremental) && incremental_install
     _apk_operations_target_name = "${target_name}__apk_operations"
@@ -3742,6 +3751,12 @@ if (!is_robolectric && enable_java_templates) {
       if (defined(invoker.additional_apks)) {
         public_deps += invoker.additional_apks
       }
+      if (use_rts) {
+        if (!defined(data_deps)) {
+          data_deps = []
+        }
+        data_deps += [ ":${invoker.target_name}__rts_filters" ]
+      }
     }
   }
 

build/config/rts.gni

@@ -0,0 +1,7 @@
+declare_args() {
+  # Regression Test Selection (RTS) will use a ML model
+  # to predict what test cases can be excluded from a
+  # given test suite based on historical data when using
+  # a .filter file.
+  use_rts = false
+}

testing/test.gni

@@ -10,6 +10,7 @@ import("//build/config/chromeos/args.gni")
 import("//build/config/chromeos/ui_mode.gni")
 import("//build/config/devtools.gni")
 import("//build/config/gclient_args.gni")
+import("//build/config/rts.gni")
 import("//build/rust/rust_static_library.gni")
 import("//build_overrides/build.gni")
 
@@ -362,6 +363,17 @@ template("mixed_test") {
 #      This should be a list of the test names, for example
 #      fuzztests = [ "MyTestClass.MyTestName" ]
 template("test") {
+  # Ensures a test filter file exists and if not, creates a dummy file.
+  # The Regression Test Selection (rts) flag is passed in mb.py and used
+  # to filter out test cases. Flag ensures that a file exists.
+  if (use_rts) {
+    action("${target_name}__rts_filters") {
+      script = "//build/add_rts_filters.py"
+      rts_file = "${root_build_dir}/gen/rts/${invoker.target_name}.filter"
+      args = [ rebase_path(rts_file, root_build_dir) ]
+      outputs = [ rts_file ]
+    }
+  }
   testonly = true
   if (!is_ios) {
     assert(!defined(invoker.is_xctest) || !invoker.is_xctest,
@@ -460,6 +472,10 @@ template("test") {
 
         # Don't output to the root or else conflict with the group() below.
         output_name = rebase_path(_exec_output, root_out_dir)
+
+        if (use_rts) {
+          data_deps += [ ":${invoker.target_name}__rts_filters" ]
+        }
       }
 
       create_native_executable_dist(_dist_target) {
@@ -469,6 +485,12 @@ template("test") {
         if (defined(invoker.extra_dist_files)) {
           extra_files = invoker.extra_dist_files
         }
+        if (use_rts) {
+          if (!defined(data_deps)) {
+            data_deps = []
+          }
+          data_deps += [ ":${invoker.target_name}__rts_filters" ]
+        }
       }
     } else {
       _library_target_name = "${target_name}__library"
@@ -598,6 +620,10 @@ template("test") {
         if (defined(_unwind_table_asset_name)) {
           deps += [ ":${_unwind_table_asset_name}" ]
         }
+
+        if (use_rts) {
+          data_deps = [ ":${invoker.target_name}__rts_filters" ]
+        }
       }
     }
 
@@ -618,6 +644,9 @@ template("test") {
       test_name = _output_name
       test_suite = _output_name
       test_type = "gtest"
+      if (use_rts) {
+        data_deps += [ ":${invoker.target_name}__rts_filters" ]
+      }
     }
 
     # Create a wrapper script rather than using a group() in order to ensure
@@ -652,6 +681,9 @@ template("test") {
       if (tests_have_location_tags) {
         data = [ "//testing/location_tags.json" ]
       }
+      if (use_rts) {
+        data_deps += [ ":${invoker.target_name}__rts_filters" ]
+      }
     }
   } else if (is_fuchsia) {
     assert(!defined(invoker.use_xvfb) || !invoker.use_xvfb)
@@ -928,6 +960,9 @@ template("test") {
       # Include the generate_wrapper as part of data_deps
       data_deps += [ ":${_wrapper_output_name}" ]
       write_runtime_deps = _runtime_deps_file
+      if (use_rts) {
+        data_deps += [ ":${invoker.target_name}__rts_filters" ]
+      }
       if (!defined(deps)) {
         deps = []
       }
@@ -955,6 +990,9 @@ template("test") {
         if (tests_have_location_tags) {
           data = [ "//testing/location_tags.json" ]
         }
+        if (use_rts) {
+          data_deps = [ ":${invoker.target_name}__rts_filters" ]
+        }
       }
     }
 
@@ -981,6 +1019,9 @@ template("test") {
       }
 
       data_deps += [ "//testing:test_scripts_shared" ]
+      if (use_rts) {
+        data_deps += [ ":${invoker.target_name}__rts_filters" ]
+      }
     }
   } else if (!is_nacl) {
     if (is_mac || is_win) {
@@ -1031,6 +1072,9 @@ template("test") {
       if (fail_on_san_warnings) {
         executable_args += [ "--fail-san=1" ]
       }
+      if (use_rts) {
+        data_deps += [ ":${invoker.target_name}__rts_filters" ]
+      }
     }
 
     mixed_test(target_name) {
@@ -1056,6 +1100,9 @@ template("test") {
       }
 
       data_deps += [ "//testing:test_scripts_shared" ]
+      if (use_rts) {
+        data_deps += [ ":${invoker.target_name}__rts_filters" ]
+      }
     }
   } else {
     # This is a catch-all clause for NaCl toolchains and other random
@@ -1076,6 +1123,9 @@ template("test") {
       }
 
       data_deps += [ "//testing:test_scripts_shared" ]
+      if (use_rts) {
+        data_deps += [ ":${invoker.target_name}__rts_filters" ]
+      }
     }
   }
 }
@@ -1110,6 +1160,15 @@ template("script_test") {
   assert(!(_enable_logdog_wrapper && _enable_cros_wrapper),
          "The logdog and cros_test wrappers are mutually exclusive")
 
+  if (use_rts) {
+    action("${target_name}__rts_filters") {
+      script = "//build/add_rts_filters.py"
+      rts_file = "${root_build_dir}/gen/rts/${invoker.target_name}.filter"
+      args = [ rebase_path(rts_file, root_build_dir) ]
+      outputs = [ rts_file ]
+    }
+  }
+
   _shared_data = [ invoker.script ]
   if (defined(invoker.data)) {
     _shared_data += invoker.data