[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.

[vogelheim, 2016/06/30 11:08:02]

Clever. I really like this!

I still have something to [complain|improve], though: :) 

Would it make sense to - instead of checking for v8_build_config.json, to check
for presence of args.gn, and if so use the result of "gn args out/XXX --list
--short" and extract the value from there?

It seems like every single variable we use below should be in there. Also, every
future variable declared in gn would be, too. And we don't need an additional
script and build step.

[Michael Achenbach, 2016/06/30 11:47:49]

Would be nice, unfortunately, the --list command shows you only the default
values. Not what is actually set. And I didn't wanna write a parser for the
gn.args file.

[vogelheim, 2016/06/30 12:09:39]

Pity. I had indeed misunderstood what --list does. :-(

+  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):
+    with open(build_config_path) as f:
+      build_config = json.load(f)
+    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())