rocksdb/build_tools/amalgamate.py

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#!/usr/bin/python
# amalgamate.py creates an amalgamation from a unity build.
# It can be run with either Python 2 or 3.
# An amalgamation consists of a header that includes the contents of all public
# headers and a source file that includes the contents of all source files and
# private headers.
#
# This script works by starting with the unity build file and recursively expanding
# #include directives. If the #include is found in a public include directory,
# that header is expanded into the amalgamation header.
#
# A particular header is only expanded once, so this script will
# break if there are multiple inclusions of the same header that are expected to
# expand differently. Similarly, this type of code causes issues:
#
# #ifdef FOO
# #include "bar.h"
# // code here
# #else
# #include "bar.h" // oops, doesn't get expanded
# // different code here
# #endif
#
# The solution is to move the include out of the #ifdef.
from __future__ import print_function
import argparse
from os import path
import re
import sys
include_re = re.compile('^[ \t]*#include[ \t]+"(.*)"[ \t]*$')
included = set()
excluded = set()
def find_header(name, abs_path, include_paths):
samedir = path.join(path.dirname(abs_path), name)
if path.exists(samedir):
return samedir
for include_path in include_paths:
include_path = path.join(include_path, name)
if path.exists(include_path):
return include_path
return None
def expand_include(include_path, f, abs_path, source_out, header_out, include_paths, public_include_paths):
if include_path in included:
return False
included.add(include_path)
with open(include_path) as f:
print('#line 1 "{}"'.format(include_path), file=source_out)
process_file(f, include_path, source_out, header_out, include_paths, public_include_paths)
return True
def process_file(f, abs_path, source_out, header_out, include_paths, public_include_paths):
for (line, text) in enumerate(f):
m = include_re.match(text)
if m:
filename = m.groups()[0]
# first check private headers
include_path = find_header(filename, abs_path, include_paths)
if include_path:
if include_path in excluded:
source_out.write(text)
expanded = False
else:
expanded = expand_include(include_path, f, abs_path, source_out, header_out, include_paths, public_include_paths)
else:
# now try public headers
include_path = find_header(filename, abs_path, public_include_paths)
if include_path:
# found public header
expanded = False
if include_path in excluded:
source_out.write(text)
else:
expand_include(include_path, f, abs_path, header_out, None, public_include_paths, [])
else:
sys.exit("unable to find {}, included in {} on line {}".format(filename, abs_path, line))
if expanded:
print('#line {} "{}"'.format(line+1, abs_path), file=source_out)
elif text != "#pragma once\n":
source_out.write(text)
def main():
parser = argparse.ArgumentParser(description="Transform a unity build into an amalgamation")
parser.add_argument("source", help="source file")
parser.add_argument("-I", action="append", dest="include_paths", help="include paths for private headers")
parser.add_argument("-i", action="append", dest="public_include_paths", help="include paths for public headers")
parser.add_argument("-x", action="append", dest="excluded", help="excluded header files")
parser.add_argument("-o", dest="source_out", help="output C++ file", required=True)
parser.add_argument("-H", dest="header_out", help="output C++ header file", required=True)
args = parser.parse_args()
include_paths = list(map(path.abspath, args.include_paths or []))
public_include_paths = list(map(path.abspath, args.public_include_paths or []))
excluded.update(map(path.abspath, args.excluded or []))
filename = args.source
abs_path = path.abspath(filename)
with open(filename) as f, open(args.source_out, 'w') as source_out, open(args.header_out, 'w') as header_out:
print('#line 1 "{}"'.format(filename), file=source_out)
print('#include "{}"'.format(header_out.name), file=source_out)
process_file(f, abs_path, source_out, header_out, include_paths, public_include_paths)
if __name__ == "__main__":
main()