[tools/perf] Guess trace processor path when running on bots

Build directories on bots follow more or less unified naming scheme,
so it's possible to guess the path to the trace processor.

Bug: 1028612
Change-Id: I6065fc2bac2ca23dcdf9363b4defb43b7cb8d22d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1936314
Commit-Queue: Mikhail Khokhlov <khokhlov@google.com>
Reviewed-by: Juan Antonio Navarro Pérez <perezju@chromium.org>
Cr-Commit-Position: refs/heads/master@{#719560}

tools/perf/core/results_processor/command_line.py

@@ -16,6 +16,7 @@ import sys
 
 from py_utils import cloud_storage
 
+from core import path_util
 from core.results_processor import formatters
 from core.results_processor import util
 from core.results_processor import trace_processor
@@ -70,10 +71,10 @@ def ArgumentParser(standalone=False):
           'How to interpret the testPath attribute.',
           'Available options: %(choices)s. Default: %(default)s.'))
   group.add_argument(
-      '--trace-processor-path', default=trace_processor.DEFAULT_TP_PATH,
+      '--trace-processor-path',
       help=Sentences(
           'Path to trace processor shell.',
-          'Default: %(default)s.'))
+          'Default: try to guess based on common build directory names.'))
   group.add_argument(
       '--upload-results', action='store_true',
       help='Upload generated artifacts to cloud storage.')
@@ -144,6 +145,9 @@ def ProcessOptions(options):
   if 'none' in options.output_formats:
     options.output_formats.remove('none')
 
+  if not options.trace_processor_path:
+    options.trace_processor_path = _GuessTraceProcessorPath()
+
 
 def _CreateTopLevelParser(standalone):
   """Create top level parser, and group for result options."""
@@ -171,5 +175,28 @@ def _DefaultOutputDir():
     return os.getcwd()
 
 
+def _GuessTraceProcessorPath():
+  """Return path to trace processor binary.
+
+  When we run on bots, there's only one build directory, so we just return
+  the path to trace processor binary located in that directory. Otherwise
+  we don't guess, but leave it to the user to supply a path.
+  """
+  build_dirs = ['build', 'out', 'xcodebuild']
+  build_types = ['Debug', 'Debug_x64', 'Release', 'Release_x64', 'Default']
+  candidate_paths = []
+  for build_dir in build_dirs:
+    for build_type in build_types:
+      candidate_path = os.path.join(
+          path_util.GetChromiumSrcDir(), build_dir, build_type,
+          trace_processor.TP_BINARY_NAME)
+      if os.path.isfile(candidate_path):
+        candidate_paths.append(candidate_path)
+  if len(candidate_paths) == 1:
+    return candidate_paths[0]
+  else:
+    return None
+
+
 def Sentences(*args):
   return ' '.join(s for s in args if s)

tools/perf/core/results_processor/command_line_unittest.py

@@ -46,6 +46,8 @@ class ProcessOptionsTestCase(unittest.TestCase):
 
     mock.patch(module('_DefaultOutputDir'),
                return_value='/path/to/output_dir').start()
+    mock.patch(module('path_util.GetChromiumSrcDir'),
+               return_value='/path/to/chromium').start()
 
   def tearDown(self):
     mock.patch.stopall()
@@ -135,6 +137,32 @@ class TestProcessOptions(ProcessOptionsTestCase):
          '--output-format', 'html', '--output-format', 'csv'])
     self.assertEqual(options.output_formats, ['csv', 'html'])
 
+  def testTraceProcessorPath_noBuildDir(self):
+    options = self.ParseArgs([])
+    self.assertIsNone(options.trace_processor_path)
+
+  def testTraceProcessorPath_oneBuildDir(self):
+    def isfile(path):
+      return path == '/path/to/chromium/out/Release/trace_processor_shell'
+
+    with mock.patch(module('os.path.isfile')) as isfile_patch:
+      isfile_patch.side_effect = isfile
+      options = self.ParseArgs([])
+
+    self.assertEqual(options.trace_processor_path,
+                     '/path/to/chromium/out/Release/trace_processor_shell')
+
+  def testTraceProcessorPath_twoBuildDirs(self):
+    def isfile(path):
+      return path in ['/path/to/chromium/out/Release/trace_processor_shell',
+                      '/path/to/chromium/out/Debug/trace_processor_shell']
+
+    with mock.patch(module('os.path.isfile')) as isfile_patch:
+      isfile_patch.side_effect = isfile
+      options = self.ParseArgs([])
+
+    self.assertIsNone(options.trace_processor_path)
+
 
 class StandaloneTestProcessOptions(ProcessOptionsTestCase):
   def setUp(self):

tools/perf/core/results_processor/trace_processor.py

@@ -8,12 +8,10 @@ import os
 import shutil
 import subprocess
 
-from core import path_util
 from py_utils import tempfile_ext
 
 
-DEFAULT_TP_PATH = os.path.join(
-    path_util.GetChromiumSrcDir(), 'out', 'Debug', 'trace_processor_shell')
+TP_BINARY_NAME = 'trace_processor_shell'
 EXPORT_JSON_QUERY_TEMPLATE = 'select export_json(%s)\n'
 
 
@@ -23,6 +21,9 @@ def _SqlString(s):
 
 
 def ConvertProtoTracesToJson(trace_processor_path, proto_files, json_path):
+  if trace_processor_path is None:
+    raise RuntimeError('Trace processor executable is not supplied. '
+                       'Please use the --trace-processor-path flag.')
   if not os.path.isfile(trace_processor_path):
     raise RuntimeError("Can't find trace processor executable at %s" %
                        trace_processor_path)