tools/llvm-shlib/gen-msvc-exports.py

   1 #===- gen-msvc-exports.py - Generate C API export file -------*- python -*--===#
   2 #
   3 # Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 # See https://llvm.org/LICENSE.txt for license information.
   5 # SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 #
   7 #===------------------------------------------------------------------------===#
   8 #
   9 # Generate an export file from a list of given LIB files. This only exports symbols
  10 # that start with LLVM, so it only exports the LLVM C API.
  11 #
  12 # To have CMake run this, set LLVM_BUILD_LLVM_C_DYLIB to on while
  13 # building on Windows.
  14 #
  15 # To run manually, build LLVM with Visual Studio, use a Command prompt
  16 # to navigate to the directory with the .lib files (Debug\lib etc). Then run
  17 #     python C:\Path\To\gen-msvc-exports.py --nm ..\bin\llvm-nm.exe LLVM*.lib
  18 #
  19 # If you're generating a 32 bit DLL, use the `--underscore` flag.
  20 # If you want to use a different `llvm-nm` executable, pass the path
  21 # with the `--nm` flag.
  22 #
  23 # You can use the --output flag to set the name of the export file.
  24 #
  25 #===------------------------------------------------------------------------===#
  26 from tempfile import mkstemp
  27 from contextlib import contextmanager
  28 from subprocess import check_call
  29 import argparse
  30 import os
  31 import re
  32
  33
  34 _UNDERSCORE_REGEX = {
  35     False: re.compile(r"^\w+\s+T\s+(LLVM.*)$"),
  36     True:  re.compile(r"^\w+\s+T\s+_(LLVM.*)$")
  37 }
  38
  39
  40 @contextmanager
  41 def removing(path):
  42     try:
  43         yield path
  44     finally:
  45         os.unlink(path)
  46
  47
  48 def touch_tempfile(*args, **kwargs):
  49     fd, name = mkstemp(*args, **kwargs)
  50     os.close(fd)
  51     return name
  52
  53
  54 def gen_llvm_c_export(output, underscore, libs, nm):
  55     """Generate the export file for the LLVM-C DLL.
  56
  57     Run `nm` for each lib in `libs`, and output an export file
  58     to `output`. If `underscore` is true, symbols will
  59     be assumed to be prefixed with an underscore.
  60     """
  61     with removing(touch_tempfile(prefix='dumpout', suffix='.txt')) as dumpout:
  62
  63         # Get the right regex.
  64         p = _UNDERSCORE_REGEX[underscore]
  65
  66         with open(output, 'w+t') as output_f:
  67
  68             # For each lib get the LLVM* functions it exports.
  69             for lib in libs:
  70                 # Call dumpbin.
  71                 with open(dumpout, 'w+t') as dumpout_f:
  72                     check_call([nm, '-g', lib], stdout=dumpout_f)
  73
  74                 # Get the matching lines.
  75                 with open(dumpout) as dumpbin:
  76                     for line in dumpbin:
  77                         m = p.match(line)
  78                         if m is not None:
  79                             output_f.write(m.group(1) + '\n')
  80
  81
  82 def main():
  83     parser = argparse.ArgumentParser('gen-msvc-exports')
  84
  85     parser.add_argument(
  86         '-i', '--libsfile', help='file with list of libs, new line separated',
  87         action='store', default=None
  88     )
  89     parser.add_argument(
  90         '-o', '--output', help='output filename', default='LLVM-C.exports'
  91     )
  92     parser.add_argument('-u', '--underscore',
  93         help='labels are prefixed with an underscore (use for 32 bit DLLs)',
  94         action='store_true'
  95     )
  96     parser.add_argument(
  97         '--nm', help='path to the llvm-nm executable', default='llvm-nm'
  98     )
  99     parser.add_argument(
 100         'libs', metavar='LIBS', nargs='*', help='list of libraries to generate export from'
 101     )
 102
 103     ns = parser.parse_args()
 104
 105     libs = ns.libs
 106
 107     # Add if we where given a libsfile add it to the libs.
 108     if ns.libsfile:
 109         with open(ns.libsfile) as f:
 110             libs.extend(f.read().splitlines())
 111
 112     gen_llvm_c_export(ns.output, ns.underscore, libs, ns.nm)
 113
 114
 115 if __name__ == '__main__':
 116     main()