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

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