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