Merge remote-tracking branch 'remotes/dagrh/tags/pull-virtiofs-20211026' into staging
[qemu.git] / scripts / undefsym.py
1 #!/usr/bin/env python3
2
3 # Before a shared module's DSO is produced, a static library is built for it
4 # and passed to this script. The script generates -Wl,-u options to force
5 # the inclusion of symbol from libqemuutil.a if the shared modules need them,
6 # This is necessary because the modules may use functions not needed by the
7 # executable itself, which would cause the function to not be linked in.
8 # Then the DSO loading would fail because of the missing symbol.
9
10
11 import sys
12 import subprocess
13
14 def filter_lines_set(stdout, from_staticlib):
15 linesSet = set()
16 for line in stdout.splitlines():
17 tokens = line.split(b' ')
18 if len(tokens) >= 2:
19 if from_staticlib and tokens[1] == b'U':
20 continue
21 if not from_staticlib and tokens[1] != b'U':
22 continue
23 new_line = b'-Wl,-u,' + tokens[0]
24 if not new_line in linesSet:
25 linesSet.add(new_line)
26 return linesSet
27
28 def main(args):
29 if len(args) <= 3:
30 sys.exit(0)
31
32 nm = args[1]
33 staticlib = args[2]
34 pc = subprocess.run([nm, "-P", "-g", staticlib], stdout=subprocess.PIPE)
35 if pc.returncode != 0:
36 sys.exit(1)
37 staticlib_syms = filter_lines_set(pc.stdout, True)
38
39 shared_modules = args[3:]
40 pc = subprocess.run([nm, "-P", "-g"] + shared_modules, stdout=subprocess.PIPE)
41 if pc.returncode != 0:
42 sys.exit(1)
43 modules_undef_syms = filter_lines_set(pc.stdout, False)
44 lines = sorted(staticlib_syms.intersection(modules_undef_syms))
45 sys.stdout.buffer.write(b'\n'.join(lines))
46
47 if __name__ == "__main__":
48 main(sys.argv)