[gn] Automatically derive build configs in test runner.

tools/run-tests.py

 #!/usr/bin/env python
 #
 # Copyright 2012 the V8 project authors. All rights reserved.
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are
 # met:
 #
 #     * Redistributions of source code must retain the above copyright
 #       notice, this list of conditions and the following disclaimer.
 #     * Redistributions in binary form must reproduce the above
@@ skipping 12 matching lines @@
 # SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 # LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 # DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 # THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 
 from collections import OrderedDict
 import itertools
+import json
 import multiprocessing
 import optparse
 import os
 from os.path import join
 import platform
 import random
 import shlex
 import subprocess
 import sys
 import time
@@ skipping 384 matching lines @@
       'report_thread_leaks=0',
       'history_size=7',
       'report_destroy_locked=0',
     ])
 
 def ProcessOptions(options):
   global ALL_VARIANTS
   global EXHAUSTIVE_VARIANTS
   global VARIANTS
 
+  # First try to auto-detect configurations based on the build if GN was
+  # used. This can't be overridden by cmd-line arguments.
+  options.auto_detect = False
+  build_config_path = os.path.join(
+      BASE_DIR, options.outdir, "v8_build_config.json")
+  if os.path.exists(build_config_path):
+    try:
+      with open(build_config_path) as f:
+        build_config = json.load(f)
+    except Exception:
+      print ("%s exists but contains invalid json. Is your build up-to-date?" %
+             build_config_path)
+      return False
+    options.auto_detect = True
+
+    options.arch_and_mode = None
+    options.arch = build_config["v8_target_cpu"]
+    if options.arch == 'x86':
+      # TODO(machenbach): Transform all to x86 eventually.
+      options.arch = 'ia32'
+    options.asan = build_config["is_asan"]
+    options.dcheck_always_on = build_config["dcheck_always_on"]
+    options.mode = 'debug' if build_config["is_debug"] else 'release'
+    options.msan = build_config["is_msan"]
+    options.no_i18n = not build_config["v8_enable_i18n_support"]
+    options.no_snap = not build_config["v8_use_snapshot"]
+    options.tsan = build_config["is_tsan"]
+
   # Architecture and mode related stuff.
   if options.arch_and_mode:
     options.arch_and_mode = [arch_and_mode.split(".")
         for arch_and_mode in options.arch_and_mode.split(",")]
     options.arch = ",".join([tokens[0] for tokens in options.arch_and_mode])
     options.mode = ",".join([tokens[1] for tokens in options.arch_and_mode])
   options.mode = options.mode.split(",")
   for mode in options.mode:
     if not BuildbotToV8Mode(mode) in MODES:
       print "Unknown mode %s" % mode
@@ skipping 213 matching lines @@
 def Execute(arch, mode, args, options, suites):
   print(">>> Running tests for %s.%s" % (arch, mode))
 
   shell_dir = options.shell_dir
   if not shell_dir:
     if options.buildbot:
       # TODO(machenbach): Get rid of different output folder location on
       # buildbot. Currently this is capitalized Release and Debug.
       shell_dir = os.path.join(BASE_DIR, options.outdir, mode)
       mode = BuildbotToV8Mode(mode)
+    elif options.auto_detect:
+      # If an output dir with a build was passed, test directly in that
+      # directory.
+      shell_dir = os.path.join(BASE_DIR, options.outdir)
     else:
       shell_dir = os.path.join(
           BASE_DIR,
           options.outdir,
           "%s.%s" % (arch, MODES[mode]["output_folder"]),
       )
   if not os.path.exists(shell_dir):
       raise Exception('Could not find shell_dir: "%s"' % shell_dir)
 
   # Populate context object.
@@ skipping 25 matching lines @@
                         options.random_seed,
                         options.no_sorting,
                         options.rerun_failures_count,
                         options.rerun_failures_max,
                         options.predictable,
                         options.no_harness,
                         use_perf_data=not options.swarming,
                         sancov_dir=options.sancov_dir)
 
   # TODO(all): Combine "simulator" and "simulator_run".
+  # TODO(machenbach): In GN we can derive simulator run from
+  # target_arch != v8_target_arch in the dumped build config.
   simulator_run = not options.dont_skip_simulator_slow_tests and \
       arch in ['arm64', 'arm', 'mipsel', 'mips', 'mips64', 'mips64el', \
                'ppc', 'ppc64'] and \
       ARCH_GUESS and arch != ARCH_GUESS
   # Find available test suites and read test cases from them.
   variables = {
     "arch": arch,
     "asan": options.asan,
     "deopt_fuzzer": False,
     "gc_stress": options.gc_stress,
@@ skipping 122 matching lines @@
         "--coverage-dir=%s" % options.sancov_dir])
     except:
       print >> sys.stderr, "Error: Merging sancov files failed."
       exit_code = 1
 
   return exit_code
 
 
 if __name__ == "__main__":
   sys.exit(Main())