Add gn_to_bp script for SkQP.

This refactors the current gn_to_bp script and moves the common
components into a utils class.  Both gn_to_bp scripts now also
accept an optional param (--gn <gn_path>) to make it easier to run
within the Android tree where we don't have the DEPS synced.

Change-Id: Idc4de7b3993e63e21a5b7137b1873d82a8e1843e
Reviewed-on: https://skia-review.googlesource.com/102184
Commit-Queue: Derek Sollenberger <djsollen@google.com>
Reviewed-by: Mike Klein <mtklein@google.com>

1 files changed, 107 insertions, 0 deletions

diff --git a/gn/gn_to_bp_utils.py b/gn/gn_to_bp_utils.py
new file mode 100644
index 0000000000..65456408cd
--- /dev/null
+++ b/gn/gn_to_bp_utils.py
@@ -0,0 +1,107 @@
+#!/usr/bin/env python
+#
+# Copyright 2018 Google Inc.
+#
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+# Generate Android.bp for Skia from GN configuration.
+
+import argparse
+import json
+import os
+import pprint
+import string
+import subprocess
+import tempfile
+
+parser = argparse.ArgumentParser(description='Process some cmdline flags.')
+parser.add_argument('--gn', dest='gn_cmd', default='gn')
+args = parser.parse_args()
+
+def GenerateJSONFromGN(gn_args):
+  gn_args = ' '.join(sorted('%s=%s' % (k,v) for (k,v) in gn_args.iteritems()))
+  tmp = tempfile.mkdtemp()
+  subprocess.check_call([args.gn_cmd, 'gen', tmp, '--args=%s' % gn_args,
+                         '--ide=json'])
+  return json.load(open(os.path.join(tmp, 'project.json')))
+
+def _strip_slash(lst):
+  return {str(p.lstrip('/')) for p in lst}
+
+def GrabDependentValues(js, name, value_type, list_to_extend, exclude):
+  # Grab the values from other targets that $name depends on (e.g. optional
+  # Skia components, gms, tests, etc).
+  for dep in js['targets'][name]['deps']:
+    if 'third_party' in dep:
+      continue   # We've handled all third-party DEPS as static or shared_libs.
+    if 'none' in dep:
+      continue   # We'll handle all cpu-specific sources manually later.
+    if exclude and exclude in dep:
+      continue
+    list_to_extend.update(_strip_slash(js['targets'][dep].get(value_type, [])))
+    GrabDependentValues(js, dep, value_type, list_to_extend, exclude)
+
+def CleanupCFlags(cflags):
+  # Only use the generated flags related to warnings.
+  cflags = {s for s in cflags if s.startswith('-W')}
+  # Add the rest of the flags we want.
+  cflags = cflags.union([
+    "-fvisibility=hidden",
+    "-D_FORTIFY_SOURCE=1",
+    "-DSKIA_DLL",
+    "-DSKIA_IMPLEMENTATION=1",
+    "-DATRACE_TAG=ATRACE_TAG_VIEW",
+    "-DSK_PRINT_CODEC_MESSAGES",
+  ])
+
+  # We need to undefine FORTIFY_SOURCE before we define it. Insert it at the
+  # beginning after sorting.
+  cflags = sorted(cflags)
+  cflags.insert(0, "-U_FORTIFY_SOURCE")
+  return cflags
+
+def CleanupCCFlags(cflags_cc):
+  # Only use the generated flags related to warnings.
+  cflags_cc       = {s for s in cflags_cc      if s.startswith('-W')}
+  # Add the rest of the flags we want.
+  cflags_cc.add("-fexceptions")
+  return cflags_cc
+
+def _get_path_info(path, kind):
+  assert path == "../src"
+  assert kind == "abspath"
+  # While we want absolute paths in GN, relative paths work best here.
+  return "src"
+
+def GetArchSources(opts_file):
+  # For architecture specific files, it's easier to just read the same source
+  # that GN does (opts.gni) rather than re-run GN once for each architecture.
+
+  # This .gni file we want to read is close enough to Python syntax
+  # that we can use execfile() if we supply definitions for GN builtins.
+  builtins = { 'get_path_info': _get_path_info }
+  defs = {}
+  execfile(opts_file, builtins, defs)
+
+  # Perform any string substitutions.
+  for arch in defs:
+    defs[arch] = [ p.replace('$_src', 'src') for p in defs[arch]]
+
+  return defs
+
+def WriteUserConfig(userConfigPath, defines):
+  # Most defines go into SkUserConfig.h
+  defines.remove('NDEBUG')                 # Controlled by the Android build
+  defines.remove('SKIA_IMPLEMENTATION=1')  # don't export this define.
+
+  #... and all the #defines we want to put in SkUserConfig.h.
+  with open(userConfigPath, 'w') as f:
+    print >>f, '// DO NOT MODIFY! This file is autogenerated by gn_to_bp.py.'
+    print >>f, '// If need to change a define, modify SkUserConfigManual.h'
+    print >>f, '#ifndef SkUserConfig_DEFINED'
+    print >>f, '#define SkUserConfig_DEFINED'
+    print >>f, '#include "SkUserConfigManual.h"'
+    for define in sorted(defines):
+      print >>f, '  #define', define.replace('=', ' ')
+    print >>f, '#endif//SkUserConfig_DEFINED'