1#!/usr/bin/env python3
2
3import os
4import sys
5import argparse
6import sysconfig
7
8
9def relpath_nodots(path, base):
10    rel = os.path.normpath(os.path.relpath(path, base))
11    assert not os.path.isabs(rel)
12    parts = rel.split(os.path.sep)
13    if parts and parts[0] == '..':
14        raise ValueError(f"{path} is not under {base}")
15    return rel
16
17def main():
18    parser = argparse.ArgumentParser(description="extract cmake variables from python")
19    parser.add_argument("variable_name")
20    args = parser.parse_args()
21    if args.variable_name == "LLDB_PYTHON_RELATIVE_PATH":
22        # LLDB_PYTHON_RELATIVE_PATH is the relative path from lldb's prefix
23        # to where lldb's python libraries will be installed.
24        #
25        # The way we're going to compute this is to take the relative path from
26        # PYTHON'S prefix to where python libraries are supposed to be
27        # installed.
28        #
29        # The result is if LLDB and python are give the same prefix, then
30        # lldb's python lib will be put in the correct place for python to find it.
31        # If not, you'll have to use lldb -P or lldb -print-script-interpreter-info
32        # to figure out where it is.
33        print(relpath_nodots(sysconfig.get_path("platlib"), sys.prefix))
34    elif args.variable_name == "LLDB_PYTHON_EXE_RELATIVE_PATH":
35        tried = list()
36        exe = sys.executable
37        prefix = os.path.realpath(sys.prefix)
38        while True:
39            try:
40                print(relpath_nodots(exe, prefix))
41                break
42            except ValueError:
43                tried.append(exe)
44                if os.path.islink(exe):
45                    exe = os.path.join(os.path.realpath(os.path.dirname(exe)), os.readlink(exe))
46                    continue
47                else:
48                    print("Could not find a relative path to sys.executable under sys.prefix", file=sys.stderr)
49                    for e in tried:
50                        print("tried:", e, file=sys.stderr)
51                    print("realpath(sys.prefix):", prefix, file=sys.stderr)
52                    print("sys.prefix:", sys.prefix, file=sys.stderr)
53                    sys.exit(1)
54    elif args.variable_name == "LLDB_PYTHON_EXT_SUFFIX":
55        print(sysconfig.get_config_var('EXT_SUFFIX'))
56    else:
57        parser.error(f"unknown variable {args.variable_name}")
58
59if __name__ == '__main__':
60    main()