1 files changed, 509 insertions, 0 deletions
diff --git a/tools/gen_struct_info.py b/tools/gen_struct_info.py
new file mode 100644
index 00000000..aab128eb
--- /dev/null
+++ b/tools/gen_struct_info.py
@@ -0,0 +1,509 @@
+# -*- encoding: utf8 -*-
+
+'''
+This tool extracts information about structs and defines from the C headers.
+You can pass either the raw header files or JSON files to this script.
+
+The JSON input format is as follows:
+[
+  {
+    'file': 'some/header.h',
+    'structs': {
+      'struct_name': [
+        'field1',
+        'field2',
+        'field3',
+        {
+          'field4': [
+            'nested1',
+            'nested2',
+            {
+              'nested3': [
+                'deep_nested1',
+                ...
+              ]
+            }
+            ...
+          ]
+        },
+        'field5'
+      ],
+      'other_struct': [
+        'field1',
+        'field2',
+        ...
+      ]
+    },
+    'defines': [
+      'DEFINE_1',
+      'DEFINE_2',
+      ['f', 'FLOAT_DEFINE'],
+      'DEFINE_3',
+      ...
+    ]
+  },
+  {
+    'file': 'some/other/header.h',
+    ...
+  }
+]
+
+Please note that the 'f' for 'FLOAT_DEFINE' is just the format passed to printf(), you can put anything printf() understands.
+If you call this script with the flag "-f" and pass a header file, it will create an automated boilerplate for you.
+
+The JSON output format is based on the return value of Runtime.generateStructInfo().
+{
+  'structs': {
+    'struct_name': {
+      '__size__': <the struct's size>,
+      'field1': <field1's offset>,
+      'field2': <field2's offset>,
+      'field3': <field3's offset>,
+      'field4': {
+        '__size__': <field4's size>,
+        'nested1': <nested1's offset>,
+        ...
+      },
+      ...
+    }
+  },
+  'defines': {
+    'DEFINE_1': <DEFINE_1's value>,
+    ...
+  }
+}
+
+'''
+
+import sys, os, re, json, argparse, tempfile, subprocess
+import shared
+QUIET = (__name__ != '__main__')
+
+def show(msg):
+  global QUIET
+  if not QUIET:
+    sys.stderr.write(msg + '\n')
+
+# Try to load pycparser.
+try:
+  import pycparser
+except ImportError:
+  # The import failed, warn the user.
+  show('WARN: pycparser isn\'t available. I won\'t be able to parse C files, only .json files.')
+  
+  def parse_header(path, cpp_opts):
+    # Tell the user how to get pycparser, if he or she tries to parse a C file.
+    sys.stderr.write('ERR: I need pycparser to process C files. \n')
+    sys.stderr.write('   Use "pip install pycparser" to install or download it from "https://github.com/eliben/pycparser".\n')
+    sys.exit(1)
+else:
+  # We successfully imported pycparser, the script will be completely functional.
+  
+  class DelayedRef(object):
+    def __init__(self, dest):
+      self.dest = dest
+    
+    def __str__(self):
+      return self.dest
+  
+  # For a list of node types and their fields, look here: https://github.com/eliben/pycparser/blob/master/pycparser/_c_ast.cfg
+  class FieldVisitor(pycparser.c_ast.NodeVisitor):
+    def __init__(self):
+      self._name = None
+      self.structs = {}
+      self.named_structs = {}
+    
+    def visit_Struct(self, node):
+      if node.decls == None:
+        self.named_structs[self._name] = DelayedRef(node.name)
+        return
+        
+      
+      fields = []
+      for decl in node.decls:
+        if decl.name == None:
+          # Well, this field doesn't have a name.
+          continue
+        
+        if decl.type != None and isinstance(decl.type, pycparser.c_ast.PtrDecl):
+          # This field is a pointer, there's no point in looking for nested structs.
+          fields.append(decl.name)
+        else:
+          # Look for nested structs.
+          subwalk = FieldVisitor()
+          subwalk.visit(decl)
+          
+          if subwalk.named_structs:
+            # Store the nested fields.
+            fields.append(subwalk.named_structs)
+          else:
+            # Just store the field name.
+            fields.append(decl.name)
+      
+      if node.name != None:
+        self.structs[node.name] = fields
+      
+      self.named_structs[self._name] = fields
+    
+    def visit_Union(self, node):
+      self.visit_Struct(node)
+    
+    def visit_TypeDecl(self, node):
+      # Remember the name of this typedef, so we can access it later in visit_Struct().
+      old_name = self._name
+      self._name = node.declname
+      self.generic_visit(node)
+      self._name = old_name
+  
+  # The first parameter is a structure, the second is a path (a list containing all the keys, needed to reach the destination).
+  # The last parameter is an item to look for. This function will try to follow the path into the given object and then look there for this key.
+  # As long as the nested object doesn't have the given key, it will descent into the next higher object till it finds the given key.
+  # 
+  # Example:
+  # 
+  # res = look_through({
+  #   'la1': {
+  #     'lb1': {
+  #       'lc1': 99,
+  #       'lc2': { 'ld1': 11 }
+  #       'lc2': 200
+  #     },
+  #     'nice': 100
+  #   },
+  #   'nice': 300
+  # }, ['la1', 'lb1', 'lc2'], 'nice')
+  # 
+  # print(res)    # Prints 100 .
+  # 
+  # In this case the function looked inside obj['la1']['lb1']['lc2']['nice'], then obj['la1']['lb1']['nice'] and found the value
+  # in obj['la1']['nice']. As soon as it finds a value it returns it and stops looking.
+  def look_through(obj, path, name):
+    cur_level = obj
+    path = path[:]
+    for i, p in enumerate(path):
+      cur_level = cur_level[p]
+      path[i] = cur_level
+    
+    path = [ obj ] + path
+    
+    while len(path) > 0:
+      if name in path[-1]:
+        return path[-1][name]
+      else:
+        path.pop()
+    
+    return None
+  
+  # Use the above function to resolve all DelayedRef() inside a list or dict recursively.
+  def resolve_delayed(item, root=None, path=[]):
+    if root == None:
+      root = item
+    
+    if isinstance(item, DelayedRef):
+      if item.dest in path:
+        show('WARN: Circular reference found! Field "' + path[-1] + '" references "' + item.dest + '"! (Path = ' + '/'.join([str(part) for part in path]) + ')')
+        return { '__ref__': item.dest }
+      else:
+        return look_through(root, path[:-1], item.dest)
+    elif isinstance(item, dict):
+      for name, val in item.items():
+        item[name] = resolve_delayed(val, root, path + [ name ])
+    elif isinstance(item, list):
+      for i, val in enumerate(item):
+        item[i] = resolve_delayed(val, root, path + [ i ])
+    
+    return item
+  
+  def parse_header(path, cpp_opts):
+    show('Parsing header "' + path + '"...')
+    
+    # Use clang -E as the preprocessor for pycparser.
+    ast = pycparser.parse_file(path, True, cpp_path=shared.CLANG_CC, cpp_args=['-E'] + cpp_opts)
+    
+    # Walk the parsed AST and filter out all the declared structs and their fields.
+    walker = FieldVisitor()
+    walker.visit(ast)
+    
+    walker.structs = resolve_delayed(walker.structs)
+    with open(path, 'r') as stream:
+      defines = re.findall(r'(?:^|\n)\s*#define\s+([A-Z|_|0-9]+)\s.*', stream.read())
+    
+    return {
+      'file': path,
+      'defines': defines,
+      'structs': walker.structs
+    }
+
+# The following three functions generate C code. The output of the compiled code will be
+# parsed later on and then put back together into a dict structure by parse_c_output().
+# 
+# Example:
+#   c_descent('test1', code)
+#   c_set('item', 'i%i', '111', code)
+#   c_set('item2', 'i%i', '9', code)
+#   c_set('item3', 's%s', '"Hello"', code)
+#   c_ascent(code)
+#   c_set('outer', 'f%f', '0.999', code)
+#   
+# Will result in:
+#   {
+#     'test1': {
+#       'item': 111,
+#       'item2': 9,
+#       'item3': 'Hello',
+#     },
+#     'outer': 0.999
+#   }
+def c_set(name, type_, value, code):
+  code.append('printf("K' + name + '\\n");')
+  code.append('printf("V' + type_ + '\\n", ' + value + ');')
+
+def c_descent(name, code):
+  code.append('printf("D' + name + '\\n");')
+
+def c_ascent(code):
+  code.append('printf("A\\n");')
+
+def parse_c_output(lines):
+  result = {}
+  cur_level = result
+  parent = []
+  key = None
+  
+  for line in lines:
+    arg = line[1:].strip()
+    if line[0] == 'K':
+      # This is a key
+      key = arg
+    elif line[0] == 'V':
+      # A value
+      if arg[0] == 'i':
+        arg = int(arg[1:])
+      elif arg[0] == 'f':
+        arg = float(arg[1:])
+      elif arg[0] == 's':
+        arg = arg[1:]
+      
+      cur_level[key] = arg
+    elif line[0] == 'D':
+      # Remember the current level as the last parent.
+      parent.append(cur_level)
+      
+      # We descend one level.
+      cur_level[arg] = {}
+      cur_level = cur_level[arg]
+    elif line[0] == 'A':
+      # We return to the parent dict. (One level up.)
+      cur_level = parent.pop()
+  
+  return result
+
+def gen_inspect_code(path, struct, code):
+  if path[0][-1] == '#':
+    path[0] = path[0][:-1]
+    prefix = ''
+  else:
+    prefix = 'struct '
+  
+  c_descent(path[-1], code)
+  
+  if len(path) == 1:
+    c_set('__size__', 'i%u', 'sizeof (' + prefix + path[0] + ')', code)
+  else:
+    c_set('__size__', 'i%u', 'sizeof ((' + prefix + path[0] + ' *)0)->' + '.'.join(path[1:]), code)
+    #c_set('__offset__', 'i%u', 'offsetof(' + prefix + path[0] + ', ' + '.'.join(path[1:]) + ')', code)
+  
+  for field in struct:
+    if isinstance(field, dict):
+      # We have to recurse to inspect the nested dict.
+      fname = field.keys()[0]
+      gen_inspect_code(path + [fname], field[fname], code)
+    else:
+      c_set(field, 'i%u', 'offsetof(' + prefix + path[0] + ', ' + '.'.join(path[1:] + [field]) + ')', code)
+  
+  c_ascent(code)
+
+def inspect_code(headers, cpp_opts, structs, defines):
+  show('Generating C code...')
+  
+  code = ['#include <stdio.h>', '#include <stddef.h>']
+  # Include all the needed headers.
+  for path in headers:
+    code.append('#include "' + path + '"')
+  
+  code.append('int main() {')
+  c_descent('structs', code)
+  for name, struct in structs.items():
+    gen_inspect_code([name], struct, code)
+  
+  c_ascent(code)
+  c_descent('defines', code)
+  for name, type_ in defines.items():
+    # Add the necessary python type, if missing.
+    if '%' not in type_:
+      if type_[-1] in ('d', 'i', 'u'):
+        # integer
+        type_ = 'i%' + type_
+      elif type_[-1] in ('f', 'F', 'e', 'E', 'g', 'G'):
+        # float
+        type_ = 'f%' + type_
+      elif type_[-1] in ('x', 'X', 'a', 'A', 'c', 's'):
+        # hexadecimal or string
+        type_ = 's%' + type_
+    
+    c_set(name, type_, name, code)
+  
+  code.append('return 0;')
+  code.append('}')
+  
+  # Write the source code to a temporary file.
+  src_file = tempfile.mkstemp('.c')
+  bin_file = tempfile.mkstemp('.ll')
+  
+  os.write(src_file[0], '\n'.join(code))
+  
+  # Close all unneeded FDs.
+  os.close(src_file[0])
+  os.close(bin_file[0])
+  
+  # NOTE: We can't generate an executable in the next step because it won't run on the current system without changing the target.
+  # If we change the target, some type sizes will change resulting in wrong data. As a workaround, we will be generating bitcode and
+  # run that with the LLVM interpreter. That way we can use the default target and still run the code.
+  info = []
+  try:
+    # Compile the program.
+    show('Compiling generated code...')
+    subprocess.check_call([shared.CLANG_CC, '-emit-llvm', '-S'] + cpp_opts + ['-o', bin_file[1], src_file[1]])
+    
+    # Run the compiled program.
+    show('Calling generated program...')
+    info = subprocess.check_output([shared.LLVM_INTERPRETER, bin_file[1]]).splitlines()
+  except subprocess.CalledProcessError:
+    if os.path.isfile(bin_file[1]):
+      sys.stderr.write('FAIL: Running the generated program failed!\n')
+    else:
+      sys.stderr.write('FAIL: Compilation failed!\n')
+    
+    sys.exit(1)
+  finally:
+    # Remove all temporary files.
+    os.unlink(src_file[1])
+    
+    if os.path.exists(bin_file[1]):
+      os.unlink(bin_file[1])
+  
+  # Parse the output of the program into a dict.
+  return parse_c_output(info)
+
+def parse_json(path, header_files, structs, defines):
+  with open(path, 'r') as stream:
+    # Remove comments before loading the JSON.
+    data = json.loads(re.sub(r'//.*\n', '', stream.read()))
+  
+  if not isinstance(data, list):
+    data = [ data ]
+  
+  for item in data:
+    header_files.append(item['file'])
+    for name, data in item['structs'].items():
+      if name in structs:
+        show('WARN: Description of struct "' + name + '" in file "' + item['file'] + '" replaces an existing description!')
+      
+      structs[name] = data
+    
+    for part in item['defines']:
+      if not isinstance(part, list):
+        # If no type is specified, assume integer.
+        part = ['i', part]
+      
+      if part[1] in defines:
+        show('WARN: Description of define "' + part[1] + '" in file "' + item['file'] + '" replaces an existing description!')
+      
+      defines[part[1]] = part[0]
+
+def output_json(obj, compressed=True, stream=None):
+  if stream == None:
+    stream = sys.stdout
+  elif isinstance(stream, str):
+    stream = open(stream, 'w')
+  
+  if compressed:
+    json.dump(obj, stream, separators=(',', ':'))
+  else:
+    json.dump(obj, stream, indent=4, sort_keys=True)
+  
+  stream.close()
+
+def filter_opts(opts):
+  # Only apply compiler options regarding syntax, includes and defines.
+  # We have to compile for the current system, we aren't compiling to bitcode after all.
+  out = []
+  for flag in opts:
+    if flag[:2] in ('-f', '-I', '-i', '-D', '-U'):
+      out.append(flag)
+  
+  return out
+
+def main(args):
+  global QUIET
+  
+  parser = argparse.ArgumentParser(description='Generate JSON infos for structs.')
+  parser.add_argument('headers', nargs='+', help='A header (.h) file or a JSON file with a list of structs and their fields')
+  parser.add_argument('-q', dest='quiet', action='store_true', default=False, help='Don\'t output anything besides error messages.')
+  parser.add_argument('-f', dest='list_fields', action='store_true', default=False, help='Output a list of structs and fields for the given headers.')
+  parser.add_argument('-p', dest='pretty_print', action='store_true', default=False, help='Pretty print the outputted JSON.')
+  parser.add_argument('-o', dest='output', metavar='path', default=None, help='Path to the JSON file that will be written. If omitted, the generated data will be printed to stdout.')
+  parser.add_argument('-I', dest='includes', metavar='dir', action='append', default=[], help='Add directory to include search path')
+  parser.add_argument('-D', dest='defines', metavar='define', action='append', default=[], help='Pass a define to the preprocessor')
+  parser.add_argument('-U', dest='undefines', metavar='undefine', action='append', default=[], help='Pass an undefine to the preprocessor')
+  args = parser.parse_args(args)
+  
+  QUIET = args.quiet
+  
+  # Avoid parsing problems due to gcc specifc syntax.
+  cpp_opts = ['-D_GNU_SOURCE'] + shared.COMPILER_OPTS
+  
+  # Add the user options to the list as well.
+  for path in args.includes:
+    cpp_opts.append('-I' + path)
+  
+  for arg in args.defines:
+    cpp_opts.append('-D' + arg)
+  
+  for arg in args.undefines:
+    cpp_opts.append('-U' + arg)
+  
+  if args.list_fields:
+    # Just parse the given headers and output the result.
+    data = []
+    for path in args.headers:
+      if path[-5:] == '.json':
+        show('WARN: Skipping "' + path + '" because it\'s already a JSON file!')
+      else:
+        data.append(parse_header(path, cpp_opts))
+    
+    output_json(data, not args.pretty_print, args.output)
+    sys.exit(0)
+  
+  # Look for structs in all passed headers.
+  header_files = []
+  structs = {}
+  defines = {}
+  
+  for header in args.headers:
+    if header[-5:] == '.json':
+      # This is a JSON file, parse it.
+      parse_json(header, header_files, structs, defines)
+    else:
+      # If the passed file isn't a JSON file, assume it's a header.
+      header_files.append(header)
+      data = parse_header(header, cpp_opts)
+      structs.update(data['structs'])
+      defines.extend(data['defines'])
+  
+  # Inspect all collected structs.
+  struct_info = inspect_code(header_files, cpp_opts, structs, defines)
+  output_json(struct_info, not args.pretty_print, args.output)
+
+if __name__ == '__main__':
+  main(sys.argv[1:])