xref: /openbmc/openbmc/poky/bitbake/lib/bb/process.py (revision 92b42cb3) 
1#
2# Copyright BitBake Contributors
3#
4# SPDX-License-Identifier: GPL-2.0-only
5#
6
7import logging
8import signal
9import subprocess
10import errno
11import select
12import bb
13
14logger = logging.getLogger('BitBake.Process')
15
16def subprocess_setup():
17    # Python installs a SIGPIPE handler by default. This is usually not what
18    # non-Python subprocesses expect.
19    signal.signal(signal.SIGPIPE, signal.SIG_DFL)
20
21class CmdError(RuntimeError):
22    def __init__(self, command, msg=None):
23        self.command = command
24        self.msg = msg
25
26    def __str__(self):
27        if not isinstance(self.command, str):
28            cmd = subprocess.list2cmdline(self.command)
29        else:
30            cmd = self.command
31
32        msg = "Execution of '%s' failed" % cmd
33        if self.msg:
34            msg += ': %s' % self.msg
35        return msg
36
37class NotFoundError(CmdError):
38    def __str__(self):
39        return CmdError.__str__(self) + ": command not found"
40
41class ExecutionError(CmdError):
42    def __init__(self, command, exitcode, stdout = None, stderr = None):
43        CmdError.__init__(self, command)
44        self.exitcode = exitcode
45        self.stdout = stdout
46        self.stderr = stderr
47        self.extra_message = None
48
49    def __str__(self):
50        message = ""
51        if self.stderr:
52            message += self.stderr
53        if self.stdout:
54            message += self.stdout
55        if message:
56            message = ":\n" + message
57        return (CmdError.__str__(self) +
58                " with exit code %s" % self.exitcode + message + (self.extra_message or ""))
59
60class Popen(subprocess.Popen):
61    defaults = {
62        "close_fds": True,
63        "preexec_fn": subprocess_setup,
64        "stdout": subprocess.PIPE,
65        "stderr": subprocess.PIPE,
66        "stdin": subprocess.PIPE,
67        "shell": False,
68    }
69
70    def __init__(self, *args, **kwargs):
71        options = dict(self.defaults)
72        options.update(kwargs)
73        subprocess.Popen.__init__(self, *args, **options)
74
75def _logged_communicate(pipe, log, input, extrafiles):
76    if pipe.stdin:
77        if input is not None:
78            pipe.stdin.write(input)
79        pipe.stdin.close()
80
81    outdata, errdata = [], []
82    rin = []
83
84    if pipe.stdout is not None:
85        bb.utils.nonblockingfd(pipe.stdout.fileno())
86        rin.append(pipe.stdout)
87    if pipe.stderr is not None:
88        bb.utils.nonblockingfd(pipe.stderr.fileno())
89        rin.append(pipe.stderr)
90    for fobj, _ in extrafiles:
91        bb.utils.nonblockingfd(fobj.fileno())
92        rin.append(fobj)
93
94    def readextras(selected):
95        for fobj, func in extrafiles:
96            if fobj in selected:
97                try:
98                    data = fobj.read()
99                except IOError as err:
100                    if err.errno == errno.EAGAIN or err.errno == errno.EWOULDBLOCK:
101                        data = None
102                if data is not None:
103                    func(data)
104
105    def read_all_pipes(log, rin, outdata, errdata):
106        rlist = rin
107        stdoutbuf = b""
108        stderrbuf = b""
109
110        try:
111            r,w,e = select.select (rlist, [], [], 1)
112        except OSError as e:
113            if e.errno != errno.EINTR:
114                raise
115
116        readextras(r)
117
118        if pipe.stdout in r:
119            data = stdoutbuf + pipe.stdout.read()
120            if data is not None and len(data) > 0:
121                try:
122                    data = data.decode("utf-8")
123                    outdata.append(data)
124                    log.write(data)
125                    log.flush()
126                    stdoutbuf = b""
127                except UnicodeDecodeError:
128                    stdoutbuf = data
129
130        if pipe.stderr in r:
131            data = stderrbuf + pipe.stderr.read()
132            if data is not None and len(data) > 0:
133                try:
134                    data = data.decode("utf-8")
135                    errdata.append(data)
136                    log.write(data)
137                    log.flush()
138                    stderrbuf = b""
139                except UnicodeDecodeError:
140                    stderrbuf = data
141
142    try:
143        # Read all pipes while the process is open
144        while pipe.poll() is None:
145            read_all_pipes(log, rin, outdata, errdata)
146
147        # Process closed, drain all pipes...
148        read_all_pipes(log, rin, outdata, errdata)
149    finally:
150        log.flush()
151
152    if pipe.stdout is not None:
153        pipe.stdout.close()
154    if pipe.stderr is not None:
155        pipe.stderr.close()
156    return ''.join(outdata), ''.join(errdata)
157
158def run(cmd, input=None, log=None, extrafiles=None, **options):
159    """Convenience function to run a command and return its output, raising an
160    exception when the command fails"""
161
162    if not extrafiles:
163        extrafiles = []
164
165    if isinstance(cmd, str) and not "shell" in options:
166        options["shell"] = True
167
168    try:
169        pipe = Popen(cmd, **options)
170    except OSError as exc:
171        if exc.errno == 2:
172            raise NotFoundError(cmd)
173        else:
174            raise CmdError(cmd, exc)
175
176    if log:
177        stdout, stderr = _logged_communicate(pipe, log, input, extrafiles)
178    else:
179        stdout, stderr = pipe.communicate(input)
180        if not stdout is None:
181            stdout = stdout.decode("utf-8")
182        if not stderr is None:
183            stderr = stderr.decode("utf-8")
184
185    if pipe.returncode != 0:
186        if log:
187            # Don't duplicate the output in the exception if logging it
188            raise ExecutionError(cmd, pipe.returncode, None, None)
189        raise ExecutionError(cmd, pipe.returncode, stdout, stderr)
190    return stdout, stderr
191