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