llvm/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",
  87         "--libsfile",
  88         help="file with list of libs, new line separated",
  89         action="store",
  90         default=None,
  91     )
  92     parser.add_argument(
  93         "-o", "--output", help="output filename", default="LLVM-C.exports"
  94     )
  95     parser.add_argument(
  96         "-u",
  97         "--underscore",
  98         help="labels are prefixed with an underscore (use for 32 bit DLLs)",
  99         action="store_true",
 100     )
 101     parser.add_argument(
 102         "--nm", help="path to the llvm-nm executable", default="llvm-nm"
 103     )
 104     parser.add_argument(
 105         "libs",
 106         metavar="LIBS",
 107         nargs="*",
 108         help="list of libraries to generate export from",
 109     )
 110
 111     ns = parser.parse_args()
 112
 113     libs = ns.libs
 114
 115     # Add if we where given a libsfile add it to the libs.
 116     if ns.libsfile:
 117         with open(ns.libsfile) as f:
 118             libs.extend(f.read().splitlines())
 119
 120     gen_llvm_c_export(ns.output, ns.underscore, libs, ns.nm)
 121
 122
 123 if __name__ == "__main__":
 124     main()