undefsym.py (1637B)
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)