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1#!/usr/bin/env python
2# Copyright 2019 Google LLC
3#
4# This source code is licensed under the BSD-style license found in the
5# LICENSE file in the root directory of this source tree.
6
7import argparse
8import codecs
9import io
10import re
11import sys
12from itertools import chain
13
14
15def key_value_pair(line):
16  key, value = line.split("=", 1)
17  # represent value as integer, if possible, otherwise as str
18  try:
19    value = int(value)
20  except ValueError:
21    pass
22  return key, value
23
24
25parser = argparse.ArgumentParser(description='XNNPACK generator')
26parser.add_argument("input", metavar="FILE", nargs=1,
27          help="Input file")
28parser.add_argument("-D", dest="defines", metavar="KEY=VALUE", nargs="*",
29          type=key_value_pair, action="append",
30          help="Predefined variables")
31parser.add_argument("-o", "--output",
32          help='Output file')
33parser.set_defaults(defines=list())
34
35
36LEADING_WHITESPACE_REGEX = re.compile(r"^\s*", flags=0)
37
38
39def extract_leading_whitespace(line):
40  match = re.match(r"\s*", line)
41  return match.group(0) if match else ""
42
43
44def escape(line):
45  output_parts = []
46  while "${" in line:
47    start_pos = line.index("${")
48    end_pos = line.index("}", start_pos + 2)
49    if start_pos != 0:
50      output_parts.append("\"" + line[:start_pos].replace("\"", "\\\"") + "\"")
51    output_parts.append("str(" + line[start_pos+2:end_pos] + ")")
52    line = line[end_pos+1:]
53  if line:
54    output_parts.append("\"" + line.replace("\"", "\\\"") + "\"")
55  return " + ".join(output_parts)
56
57
58def preprocess(input_text, input_globals, input_path="codegen"):
59  input_lines = input_text.splitlines()
60  python_lines = ["from __future__ import print_function"]
61
62  blank_lines = 0
63
64  last_line = ""
65  last_indent = ""
66
67  # List of tuples (total_index, python_indent)
68  indent_stack = [("", "")]
69
70  # Indicates whether this is the first line inside Python
71  # code block (i.e. for, while, if, elif, else)
72  python_block_start = True
73  for i, input_line in enumerate(input_lines):
74    if input_line == "":
75      blank_lines += 1
76      continue
77
78    input_indent = extract_leading_whitespace(input_line)
79    if python_block_start:
80      assert input_indent.startswith(last_indent)
81      extra_python_indent = input_indent[len(last_indent):]
82      python_indent = indent_stack[-1][1] + extra_python_indent
83      indent_stack.append((input_indent, python_indent))
84      assert input_indent.startswith(indent_stack[-1][0])
85    else:
86      while not input_indent.startswith(indent_stack[-1][0]):
87        del indent_stack[-1]
88    python_block_start = False
89
90    python_indent = indent_stack[-1][1]
91    stripped_input_line = input_line.strip()
92    if stripped_input_line.startswith("$") and not stripped_input_line.startswith("${"):
93      if stripped_input_line.endswith(":"):
94        python_block_start = True
95      while blank_lines != 0:
96        python_lines.append(python_indent + "print(file=OUT_STREAM)")
97        blank_lines -= 1
98      python_lines.append(python_indent + stripped_input_line.replace("$", ""))
99    else:
100      assert input_line.startswith(python_indent)
101      while blank_lines != 0:
102        python_lines.append(python_indent + "print(file=OUT_STREAM)")
103        blank_lines -= 1
104      python_lines.append(python_indent + "print(%s, file=OUT_STREAM)" % escape(input_line[len(python_indent):]))
105    last_line = input_line
106    last_indent = input_indent
107
108  while blank_lines != 0:
109    python_lines.append(python_indent + "print(file=OUT_STREAM)")
110    blank_lines -= 1
111
112  exec_globals = dict(input_globals)
113  if sys.version_info > (3, 0):
114    output_stream = io.StringIO()
115  else:
116    output_stream = io.BytesIO()
117  exec_globals["OUT_STREAM"] = output_stream
118  python_bytecode = compile("\n".join(python_lines), input_path, 'exec')
119  exec(python_bytecode, exec_globals)
120
121  return output_stream.getvalue()
122
123
124PREAMBLE = """\
125// Auto-generated file. Do not edit!
126//   Template: {template}
127//   Generator: {generator}
128//
129"""
130
131
132def main(args):
133  options = parser.parse_args(args)
134
135  input_text = codecs.open(options.input[0], "r", encoding="utf-8").read()
136  python_globals = dict(chain(*options.defines))
137  output_text = preprocess(input_text, python_globals, options.input[0])
138
139  with codecs.open(options.output, "w", encoding="utf-8") as output_file:
140    output_file.write(PREAMBLE.format(
141      template=options.input[0], generator=sys.argv[0]))
142    output_file.write(output_text)
143
144
145if __name__ == "__main__":
146  main(sys.argv[1:])
147