Add SCons integration for [ grit build ] tool (inputs and outputs).

grit/scons.py

Index: grit/scons.py
diff --git a/grit/scons.py b/grit/scons.py
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+++ b/grit/scons.py
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+#!/usr/bin/env python
+# Copyright (c) 2012 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+'''SCons integration for GRIT.
+'''
+
+# NOTE: DO NOT IMPORT ANY GRIT STUFF HERE - we import lazily so that
+# grit and its dependencies aren't imported until actually needed.
+
+import os
+import types
+
+def _IsDebugEnabled():
+  return 'GRIT_DEBUG' in os.environ and os.environ['GRIT_DEBUG'] == '1'
+
+def _SourceToFile(source):
+  '''Return the path to the source file, given the 'source' argument as provided
+  by SCons to the _Builder or _Emitter functions.
+  '''
+  # Get the filename of the source.  The 'source' parameter can be a string,
+  # a "node", or a list of strings or nodes.
+  if isinstance(source, types.ListType):
+    source = str(source[0])
+  else:
+    source = str(source)
+  return source
+
+
+def _ParseRcFlags(flags):
+  """Gets a mapping of defines.
+
+  Args:
+    flags: env['RCFLAGS']; the input defines.
+
+  Returns:
+    A tuple of (defines, res_file):
+      defines: A mapping of {name: val}
+      res_file: None, or the specified res file for static file dependencies.
+  """
+  from grit import util
+
+  defines = {}
+  res_file = None
+  # Get the CPP defines from the environment.
+  res_flag = '--res_file='
+  for flag in flags:
+    if flag.startswith(res_flag):
+      res_file = flag[len(res_flag):]
+      continue
+    if flag.startswith('/D'):
+      flag = flag[2:]
+    name, val = util.ParseDefine(flag)
+    # Only apply to first instance of a given define
+    if name not in defines:
+      defines[name] = val
+  return (defines, res_file)
+
+
+def _Builder(target, source, env):
+  print _SourceToFile(source)
+
+  from grit import grit_runner
+  from grit.tool import build
+  options = grit_runner.Options()
+  # This sets options to default values
+  options.ReadOptions([])
+  options.input = _SourceToFile(source)
+
+  # TODO(joi) Check if we can get the 'verbose' option from the environment.
+
+  builder = build.RcBuilder(defines=_ParseRcFlags(env['RCFLAGS'])[0])
+
+  # To ensure that our output files match what we promised SCons, we
+  # use the list of targets provided by SCons and update the file paths in
+  # our .grd input file with the targets.
+  builder.scons_targets = [str(t) for t in target]
+  builder.Run(options, [])
+  return None  # success
+
+
+def _GetOutputFiles(grd, base_dir):
+  """Processes outputs listed in the grd into rc_headers and rc_alls.
+
+  Note that anything that's not an rc_header is classified as an rc_all.
+
+  Args:
+    grd: An open GRD reader.
+
+  Returns:
+    A tuple of (rc_headers, rc_alls, lang_folders):
+      rc_headers: Outputs marked as rc_header.
+      rc_alls: All other outputs.
+      lang_folders: The output language folders.
+  """
+  rc_headers = []
+  rc_alls = []
+  lang_folders = {}
+
+  # Explicit output files.
+  for output in grd.GetOutputFiles():
+    path = os.path.join(base_dir, output.GetFilename())
+    if (output.GetType() == 'rc_header'):
+      rc_headers.append(path)
+    else:
+      rc_alls.append(path)
+    if _IsDebugEnabled():
+      print 'GRIT: Added target %s' % path
+    if output.attrs['lang'] != '':
+      lang_folders[output.attrs['lang']] = os.path.dirname(path)
+
+  return (rc_headers, rc_alls, lang_folders)
+
+
+def _ProcessNodes(grd, base_dir, lang_folders):
+  """Processes the GRD nodes to figure out file dependencies.
+
+  Args:
+    grd: An open GRD reader.
+    base_dir: The base directory for filenames.
+    lang_folders: THe output language folders.
+
+  Returns:
+    A tuple of (structure_outputs, translated_files, static_files):
+      structure_outputs: Structures marked as sconsdep.
+      translated_files: Files that are structures or skeletons, and get
+        translated by GRIT.
+      static_files: Files that are includes, and are used directly by res files.
+  """
+  structure_outputs = []
+  translated_files = []
+  static_files = []
+
+  # Go through nodes, figuring out resources.  Also output certain resources
+  # as build targets, based on the sconsdep flag.
+  for node in grd:
+    if node.SatisfiesOutputCondition():
+      if node.name == 'structure':
+        translated_files.append(os.path.abspath(node.GetFilePath()))
+        # TODO(joi) Should remove the "if sconsdep is true" thing as it is a
+        # hack - see grit/node/structure.py
+        if node.HasFileForLanguage() and node.attrs['sconsdep'] == 'true':
+          for lang in lang_folders:
+            path = node.FileForLanguage(lang, lang_folders[lang],
+                                        create_file=False,
+                                        return_if_not_generated=False)
+            if path:
+              structure_outputs.append(path)
+              if _IsDebugEnabled():
+                print 'GRIT: Added target %s' % path
+      elif (node.name == 'skeleton' or
+            (node.name == 'file' and node.parent and
+             node.parent.name == 'translations')):
+        translated_files.append(os.path.abspath(node.GetFilePath()))
+      elif node.name == 'include':
+        file = node.FilenameToOpen()
+        # If it's added by file name and the file isn't easy to find, don't make
+        # it a dependency.  This could add some build flakiness, but it doesn't
+        # work otherwise.
+        if node.attrs['filenameonly'] != 'true' or os.path.exists(file):
+          static_files.append(os.path.abspath(file))
+        # If it's output from mk, look in the output directory.
+        elif node.attrs['mkoutput'] == 'true':
+          static_files.append(os.path.join(base_dir, os.path.basename(file)))
+
+  return (structure_outputs, translated_files, static_files)
+
+
+def _SetDependencies(env, base_dir, res_file, rc_alls, translated_files,
+                     static_files):
+  """Sets dependencies in the environment.
+
+  Args:
+    env: The SCons environment.
+    base_dir: The base directory for filenames.
+    res_file: The res_file specified in the RC flags.
+    rc_alls: All non-rc_header outputs.
+    translated_files: Files that are structures or skeletons, and get
+      translated by GRIT.
+    static_files: Files that are includes, and are used directly by res files.
+  """
+  if res_file:
+    env.Depends(os.path.join(base_dir, res_file), static_files)
+  else:
+    # Make a best effort dependency setup when no res file is specified.
+    translated_files.extend(static_files)
+
+  for rc_all in rc_alls:
+    env.Depends(rc_all, translated_files)
+
+
+def _Emitter(target, source, env):
+  """Modifies the list of targets to include all outputs.
+
+  Note that this also sets up the dependencies, even though it's an emitter
+  rather than a scanner.  This is so that the resource header file doesn't show
+  as having dependencies.
+
+  Args:
+    target: The list of targets to emit for.
+    source: The source or list of sources for the target.
+    env: The SCons environment.
+
+  Returns:
+    A tuple of (targets, sources).
+  """
+  from grit import grd_reader
+  from grit import util
+
+  (defines, res_file) = _ParseRcFlags(env['RCFLAGS'])
+
+  grd = grd_reader.Parse(_SourceToFile(source), debug=_IsDebugEnabled())
+  # TODO(jperkins): This is a hack to get an output context set for the reader.
+  # This should really be smarter about the language.
+  grd.SetOutputContext('en', defines)
+
+  base_dir = util.dirname(str(target[0]))
+  (rc_headers, rc_alls, lang_folders) = _GetOutputFiles(grd, base_dir)
+  (structure_outputs, translated_files, static_files) = _ProcessNodes(grd,
+      base_dir, lang_folders)
+
+  rc_alls.extend(structure_outputs)
+  _SetDependencies(env, base_dir, res_file, rc_alls, translated_files,
+                   static_files)
+
+  targets = rc_headers
+  targets.extend(rc_alls)
+
+  # Return target and source lists.
+  return (targets, source)
+
+
+# Function name is mandated by newer versions of SCons.
+def generate(env):
+  # Importing this module should be possible whenever this function is invoked
+  # since it should only be invoked by SCons.
+  import SCons.Builder
+  import SCons.Action
+
+  # The varlist parameter tells SCons that GRIT needs to be invoked again
+  # if RCFLAGS has changed since last compilation.
+  build_action = SCons.Action.FunctionAction(_Builder, varlist=['RCFLAGS'])
+  emit_action = SCons.Action.FunctionAction(_Emitter, varlist=['RCFLAGS'])
+
+  builder = SCons.Builder.Builder(action=build_action, emitter=emit_action,
+                                  src_suffix='.grd')
+
+  # Add our builder and scanner to the environment.
+  env.Append(BUILDERS = {'GRIT': builder})
+
+
+# Function name is mandated by newer versions of SCons.
+def exists(env):
+  return 1