[tools] Build generator script

tools/tool.py

Index: tools/tool.py
diff --git a/tools/tool.py b/tools/tool.py
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+#!/usr/bin/env python
+# Copyright 2016 the V8 project authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+"""Script to generate V8's gn arguments based on common developer defaults
+or builder configurations.
+
+Examples:
+
+# Generate the x64.release config in out.gn/x64.release.
+tools/tool.py x64.release
+
+# Generate into out.gn/foo.
+tools/tool.py -b x64.release foo
+
+# Pass additional gn arguments after -- (don't use spaces within gn args).
+tools/tool.py x64.optdebug -- use_goma=true
+
+# Print wrapped commands.
+tools/tool.py x64.optdebug -v
+
+# Print output of wrapped commands.
+tools/tool.py x64.optdebug -vv
+
+# Generate gn arguments of builder 'V8 Linux64 - builder' from master
+# 'client.v8' into out.gn/V8_Linux64___builder.
+tools/tool.py -m client.v8 -b 'V8 Linux64 - builder'
+"""
+
+import argparse
+import os
+import subprocess
+import sys
+
+BASE_DIR = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
+OUT_DIR = 'out.gn'
+
+
+def _sanitize_nonalpha(text):
+  return ''.join(c if (c.isalnum() or c == '.') else '_' for c in text)
+
+
+class GenerateGnArgs(object):
+  def __init__(self, args):
+    index = args.index('--') if '--' in args else len(args)
+    script_args = args[:index]
+    self.gn_args = args[index + 1:]
+
+    parser = argparse.ArgumentParser(
+      description='Generator for V8\'s gn arguments. '
+                  'Additional gn args can be separated with -- '
+                  'from the arguments to this tool.')
+    parser.add_argument(
+        'outdir', nargs='?',
+        help='optional gn output directory')
+    parser.add_argument(
+        '-b', '--builder',
+        help='build configuration or builder name from mb_config.pyl')
+    parser.add_argument(
+        '-m', '--master', default='developer_default',
+        help='config group or master from mb_config.pyl')
+    parser.add_argument(
+        '-v', '--verbosity', action='count',
+        help='increase output verbosity (can be specified multiple times)')
+    self.options = parser.parse_args(script_args)
+
+    assert (self.options.outdir or self.options.builder), (
+        'please specify either an output directory or a builder/config name, '
+        'e.g. x64.release')
+
+    if not self.options.outdir:
+      # Derive output directory from builder name.
+      self.options.outdir = _sanitize_nonalpha(self.options.builder)
+    else:
+      # Also, if this should work on windows, we might need to use \ where
+      # outdir is used as path, while using / if it's used in a gn context.
+      assert not self.options.outdir.startswith('/'), (
+        'only output directories relative to %s are supported' % OUT_DIR)
+
+    if not self.options.builder:
+      # Derive builder from output directory.
+      self.options.builder = self.options.outdir
+
+  def verbose_print_1(self, text):
+    if self.options.verbosity >= 1:
+      print '#################################################################'
+      print text
+
+  def verbose_print_2(self, text):
+    if self.options.verbosity >= 2:
+      print text
+
+  def call_cmd(self, args):
+    self.verbose_print_1(' '.join(args))
+    try:
+      output = subprocess.check_output(
+        args=args,
+        stderr=subprocess.STDOUT,
+      )
+      self.verbose_print_2(output)
+    except subprocess.CalledProcessError as e:
+      self.verbose_print_2(e.output)
+      raise
+
+  def main(self):
+    # Always operate relative to the base directory for better relative-path
+    # handling.
+    self.verbose_print_1('cd ' + BASE_DIR)
+    os.chdir(BASE_DIR)
+
+    # The directories are separated with slashes in a gn context (platform
+    # independent).
+    gn_outdir = '/'.join([OUT_DIR, self.options.outdir])
+
+    # Call MB to generate the basic configuration.
+    self.call_cmd([
+      sys.executable,
+      '-u', os.path.join('tools', 'mb', 'mb.py'),
+      'gen',
+      '-f', os.path.join('infra', 'mb', 'mb_config.pyl'),
+      '-m', self.options.master,
+      '-b', self.options.builder,
+      gn_outdir,
+    ])
+
+    # Handle extra gn arguments.
+    if self.gn_args:
+      gn_args_path = os.path.join(OUT_DIR, self.options.outdir, 'args.gn')
+      more_gn_args = '\n'.join(self.gn_args)
+
+      # Append extra gn arguments to the generated args.gn file.
+      self.verbose_print_1("Appending \"\"\"\n%s\n\"\"\" to %s." % (
+          more_gn_args, os.path.abspath(gn_args_path)))
+      with open(gn_args_path, 'a') as f:
+        f.write('\n# Additional command-line args:\n')
+        f.write(more_gn_args)
+        f.write('\n')
+
+      # Regenerate ninja files to check for errors in the additional gn args.
+      self.call_cmd(['gn', 'gen', gn_outdir])

[jochen (gone - plz use gerrit), 2016/07/12 15:09:07]

i'd be happier without this call... but otherwise, lgtm

[Michael Achenbach, 2016/07/13 07:35:19]

I thought it might be better to warn for potential errors early. E.g. a simple
typo in the additional gn args. Otherwise, the used'd see it when calling ninja
- is that acceptable? Then I could make this optional.

+    return 0
+
+if __name__ == "__main__":
+  gen = GenerateGnArgs(sys.argv[1:])
+  try:
+    sys.exit(gen.main())
+  except Exception:
+    if gen.options.verbosity < 2:
+      print ('\nHint: You can raise verbosity (-vv) to see the output of '
+             'failed commands.\n')
+    raise