ceph/src/rocksdb/build_tools/amalgamate.py

   1 #!/usr/bin/python
   2
   3 # amalgamate.py creates an amalgamation from a unity build.
   4 # It can be run with either Python 2 or 3.
   5 # An amalgamation consists of a header that includes the contents of all public
   6 # headers and a source file that includes the contents of all source files and
   7 # private headers.
   8 #
   9 # This script works by starting with the unity build file and recursively expanding
  10 # #include directives. If the #include is found in a public include directory,
  11 # that header is expanded into the amalgamation header.
  12 #
  13 # A particular header is only expanded once, so this script will
  14 # break if there are multiple inclusions of the same header that are expected to
  15 # expand differently. Similarly, this type of code causes issues:
  16 #
  17 # #ifdef FOO
  18 #   #include "bar.h"
  19 #   // code here
  20 # #else
  21 #   #include "bar.h"            // oops, doesn't get expanded
  22 #   // different code here
  23 # #endif
  24 #
  25 # The solution is to move the include out of the #ifdef.
  26
  27 from __future__ import print_function
  28
  29 import argparse
  30 from os import path
  31 import re
  32 import sys
  33
  34 include_re = re.compile('^[ \t]*#include[ \t]+"(.*)"[ \t]*$')
  35 included = set()
  36 excluded = set()
  37
  38 def find_header(name, abs_path, include_paths):
  39     samedir = path.join(path.dirname(abs_path), name)
  40     if path.exists(samedir):
  41         return samedir
  42     for include_path in include_paths:
  43         include_path = path.join(include_path, name)
  44         if path.exists(include_path):
  45             return include_path
  46     return None
  47
  48 def expand_include(include_path, f, abs_path, source_out, header_out, include_paths, public_include_paths):
  49     if include_path in included:
  50         return False
  51
  52     included.add(include_path)
  53     with open(include_path) as f:
  54         print('#line 1 "{}"'.format(include_path), file=source_out)
  55         process_file(f, include_path, source_out, header_out, include_paths, public_include_paths)
  56     return True
  57
  58 def process_file(f, abs_path, source_out, header_out, include_paths, public_include_paths):
  59     for (line, text) in enumerate(f):
  60         m = include_re.match(text)
  61         if m:
  62             filename = m.groups()[0]
  63             # first check private headers
  64             include_path = find_header(filename, abs_path, include_paths)
  65             if include_path:
  66                 if include_path in excluded:
  67                     source_out.write(text)
  68                     expanded = False
  69                 else:
  70                     expanded = expand_include(include_path, f, abs_path, source_out, header_out, include_paths, public_include_paths)
  71             else:
  72                 # now try public headers
  73                 include_path = find_header(filename, abs_path, public_include_paths)
  74                 if include_path:
  75                     # found public header
  76                     expanded = False
  77                     if include_path in excluded:
  78                         source_out.write(text)
  79                     else:
  80                         expand_include(include_path, f, abs_path, header_out, None, public_include_paths, [])
  81                 else:
  82                     sys.exit("unable to find {}, included in {} on line {}".format(filename, abs_path, line))
  83
  84             if expanded:
  85                 print('#line {} "{}"'.format(line+1, abs_path), file=source_out)
  86         elif text != "#pragma once\n":
  87             source_out.write(text)
  88
  89 def main():
  90     parser = argparse.ArgumentParser(description="Transform a unity build into an amalgamation")
  91     parser.add_argument("source", help="source file")
  92     parser.add_argument("-I", action="append", dest="include_paths", help="include paths for private headers")
  93     parser.add_argument("-i", action="append", dest="public_include_paths", help="include paths for public headers")
  94     parser.add_argument("-x", action="append", dest="excluded", help="excluded header files")
  95     parser.add_argument("-o", dest="source_out", help="output C++ file", required=True)
  96     parser.add_argument("-H", dest="header_out", help="output C++ header file", required=True)
  97     args = parser.parse_args()
  98
  99     include_paths = list(map(path.abspath, args.include_paths or []))
 100     public_include_paths = list(map(path.abspath, args.public_include_paths or []))
 101     excluded.update(map(path.abspath, args.excluded or []))
 102     filename = args.source
 103     abs_path = path.abspath(filename)
 104     with open(filename) as f, open(args.source_out, 'w') as source_out, open(args.header_out, 'w') as header_out:
 105         print('#line 1 "{}"'.format(filename), file=source_out)
 106         print('#include "{}"'.format(header_out.name), file=source_out)
 107         process_file(f, abs_path, source_out, header_out, include_paths, public_include_paths)
 108
 109 if __name__ == "__main__":
 110     main()