tools/rb/fix_stacks.py

   1 #!/usr/bin/env python3
   2 # vim:sw=4:ts=4:et:
   3 # This Source Code Form is subject to the terms of the Mozilla Public
   4 # License, v. 2.0. If a copy of the MPL was not distributed with this
   5 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
   6
   7 # This script uses `fix-stacks` to post-process the entries produced by
   8 # MozFormatCodeAddress().
   9
  10 from __future__ import absolute_import, print_function
  11 from subprocess import Popen, PIPE
  12 import atexit
  13 import os
  14 import platform
  15 import re
  16 import sys
  17
  18 # Matches lines produced by MozFormatCodeAddress(), e.g.
  19 # `#01: ???[tests/example +0x43a0]`.
  20 line_re = re.compile("#\d+: .+\[.+ \+0x[0-9A-Fa-f]+\]")
  21
  22 fix_stacks = None
  23
  24
  25 def autobootstrap():
  26     from mozbuild.configure import ConfigureSandbox
  27     import buildconfig
  28
  29     sandbox = ConfigureSandbox(
  30         {},
  31         argv=[
  32             "configure",
  33             "--help",
  34             "--host={}".format(buildconfig.substs["HOST_ALIAS"]),
  35         ],
  36     )
  37     moz_configure = os.path.join(buildconfig.topsrcdir, "build", "moz.configure")
  38     sandbox.include_file(os.path.join(moz_configure, "init.configure"))
  39     # bootstrap_search_path_order has a dependency on developer_options, which
  40     # is not defined in init.configure. Its value doesn't matter for us, though.
  41     sandbox["developer_options"] = sandbox["always"]
  42     sandbox.include_file(os.path.join(moz_configure, "bootstrap.configure"))
  43     # Expand the `bootstrap_path` template for "fix-stacks", and execute the
  44     # expanded function via `_value_for`, which will trigger autobootstrap.
  45     sandbox._value_for(sandbox["bootstrap_path"]("fix-stacks"))
  46
  47
  48 def initFixStacks(jsonMode, slowWarning, breakpadSymsDir, hide_errors):
  49     # Look in MOZ_FETCHES_DIR (for automation), then in MOZBUILD_STATE_PATH
  50     # (for a local build where the user has that set), then in ~/.mozbuild
  51     # (for a local build with default settings).
  52     base = os.environ.get(
  53         "MOZ_FETCHES_DIR",
  54         os.environ.get("MOZBUILD_STATE_PATH", os.path.expanduser("~/.mozbuild")),
  55     )
  56     fix_stacks_exe = base + "/fix-stacks/fix-stacks"
  57     if platform.system() == "Windows":
  58         fix_stacks_exe = fix_stacks_exe + ".exe"
  59
  60     if not (os.path.isfile(fix_stacks_exe) and os.access(fix_stacks_exe, os.X_OK)):
  61         try:
  62             autobootstrap()
  63         except ImportError:
  64             # We're out-of-tree (e.g. tests tasks on CI) and can't autobootstrap
  65             # (we shouldn't anyways).
  66             pass
  67
  68     if not (os.path.isfile(fix_stacks_exe) and os.access(fix_stacks_exe, os.X_OK)):
  69         raise Exception("cannot find `fix-stacks`; please run `./mach bootstrap`")
  70
  71     args = [fix_stacks_exe]
  72     if jsonMode:
  73         args.append("-j")
  74     if breakpadSymsDir:
  75         args.append("-b")
  76         args.append(breakpadSymsDir)
  77
  78     # Sometimes we need to prevent errors from going to stderr.
  79     stderr = open(os.devnull) if hide_errors else None
  80
  81     global fix_stacks
  82     fix_stacks = Popen(
  83         args, stdin=PIPE, stdout=PIPE, stderr=stderr, universal_newlines=True
  84     )
  85
  86     # Shut down the fix_stacks process on exit. We use `terminate()`
  87     # because it is more forceful than `wait()`, and the Python docs warn
  88     # about possible deadlocks with `wait()`.
  89     def cleanup(fix_stacks):
  90         for fn in [fix_stacks.stdin.close, fix_stacks.terminate]:
  91             try:
  92                 fn()
  93             except OSError:
  94                 pass
  95
  96     atexit.register(cleanup, fix_stacks)
  97
  98     if slowWarning:
  99         print(
 100             "Initializing stack-fixing for the first stack frame, this may take a while..."
 101         )
 102
 103
 104 def fixSymbols(
 105     line, jsonMode=False, slowWarning=False, breakpadSymsDir=None, hide_errors=False
 106 ):
 107     is_bytes = isinstance(line, bytes)
 108     line_str = line.decode("utf-8") if is_bytes else line
 109     if line_re.search(line_str) is None:
 110         return line
 111
 112     if not fix_stacks:
 113         initFixStacks(jsonMode, slowWarning, breakpadSymsDir, hide_errors)
 114
 115     # Sometimes `line` is lacking a trailing newline. If we pass such a `line`
 116     # to `fix-stacks` it will wait until it receives a newline, causing this
 117     # script to hang. So we add a newline if one is missing and then remove it
 118     # from the output.
 119     is_missing_newline = not line_str.endswith("\n")
 120     if is_missing_newline:
 121         line_str = line_str + "\n"
 122     fix_stacks.stdin.write(line_str)
 123     fix_stacks.stdin.flush()
 124     out = fix_stacks.stdout.readline()
 125     if is_missing_newline:
 126         out = out[:-1]
 127
 128     if is_bytes and not isinstance(out, bytes):
 129         out = out.encode("utf-8")
 130     return out
 131
 132
 133 if __name__ == "__main__":
 134     for line in sys.stdin:
 135         sys.stdout.write(fixSymbols(line))