1 files changed, 135 insertions, 0 deletions
diff --git a/tools/rb/fix_stacks.py b/tools/rb/fix_stacks.py
new file mode 100755
index 0000000000..f30aa9944a
--- /dev/null
+++ b/tools/rb/fix_stacks.py
@@ -0,0 +1,135 @@
+#!/usr/bin/env python3
+# vim:sw=4:ts=4:et:
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+# This script uses `fix-stacks` to post-process the entries produced by
+# MozFormatCodeAddress().
+
+import atexit
+import os
+import platform
+import re
+import sys
+from subprocess import PIPE, Popen
+
+# Matches lines produced by MozFormatCodeAddress(), e.g.
+# `#01: ???[tests/example +0x43a0]`.
+line_re = re.compile("#\d+: .+\[.+ \+0x[0-9A-Fa-f]+\]")
+
+fix_stacks = None
+
+
+def autobootstrap():
+    import buildconfig
+    from mozbuild.configure import ConfigureSandbox
+
+    sandbox = ConfigureSandbox(
+        {},
+        argv=[
+            "configure",
+            "--help",
+            "--host={}".format(buildconfig.substs["HOST_ALIAS"]),
+        ],
+    )
+    moz_configure = os.path.join(buildconfig.topsrcdir, "build", "moz.configure")
+    sandbox.include_file(os.path.join(moz_configure, "init.configure"))
+    # bootstrap_search_path_order has a dependency on developer_options, which
+    # is not defined in init.configure. Its value doesn't matter for us, though.
+    sandbox["developer_options"] = sandbox["always"]
+    sandbox.include_file(os.path.join(moz_configure, "bootstrap.configure"))
+    # Expand the `bootstrap_path` template for "fix-stacks", and execute the
+    # expanded function via `_value_for`, which will trigger autobootstrap.
+    sandbox._value_for(sandbox["bootstrap_path"]("fix-stacks"))
+
+
+def initFixStacks(jsonMode, slowWarning, breakpadSymsDir, hide_errors):
+    # Look in MOZ_FETCHES_DIR (for automation), then in MOZBUILD_STATE_PATH
+    # (for a local build where the user has that set), then in ~/.mozbuild
+    # (for a local build with default settings).
+    base = os.environ.get(
+        "MOZ_FETCHES_DIR",
+        os.environ.get("MOZBUILD_STATE_PATH", os.path.expanduser("~/.mozbuild")),
+    )
+    fix_stacks_exe = base + "/fix-stacks/fix-stacks"
+    if platform.system() == "Windows":
+        fix_stacks_exe = fix_stacks_exe + ".exe"
+
+    if not (os.path.isfile(fix_stacks_exe) and os.access(fix_stacks_exe, os.X_OK)):
+        try:
+            autobootstrap()
+        except ImportError:
+            # We're out-of-tree (e.g. tests tasks on CI) and can't autobootstrap
+            # (we shouldn't anyways).
+            pass
+
+    if not (os.path.isfile(fix_stacks_exe) and os.access(fix_stacks_exe, os.X_OK)):
+        raise Exception("cannot find `fix-stacks`; please run `./mach bootstrap`")
+
+    args = [fix_stacks_exe]
+    if jsonMode:
+        args.append("-j")
+    if breakpadSymsDir:
+        args.append("-b")
+        args.append(breakpadSymsDir)
+
+    # Sometimes we need to prevent errors from going to stderr.
+    stderr = open(os.devnull) if hide_errors else None
+
+    global fix_stacks
+    fix_stacks = Popen(
+        args, stdin=PIPE, stdout=PIPE, stderr=stderr, universal_newlines=True
+    )
+
+    # Shut down the fix_stacks process on exit. We use `terminate()`
+    # because it is more forceful than `wait()`, and the Python docs warn
+    # about possible deadlocks with `wait()`.
+    def cleanup(fix_stacks):
+        for fn in [fix_stacks.stdin.close, fix_stacks.terminate]:
+            try:
+                fn()
+            except OSError:
+                pass
+
+    atexit.register(cleanup, fix_stacks)
+
+    if slowWarning:
+        print(
+            "Initializing stack-fixing for the first stack frame, this may take a while..."
+        )
+
+
+def fixSymbols(
+    line, jsonMode=False, slowWarning=False, breakpadSymsDir=None, hide_errors=False
+):
+    is_bytes = isinstance(line, bytes)
+    line_str = line.decode("utf-8") if is_bytes else line
+    if line_re.search(line_str) is None:
+        return line
+
+    if not fix_stacks:
+        initFixStacks(jsonMode, slowWarning, breakpadSymsDir, hide_errors)
+
+    # Sometimes `line` is lacking a trailing newline. If we pass such a `line`
+    # to `fix-stacks` it will wait until it receives a newline, causing this
+    # script to hang. So we add a newline if one is missing and then remove it
+    # from the output.
+    is_missing_newline = not line_str.endswith("\n")
+    if is_missing_newline:
+        line_str = line_str + "\n"
+    fix_stacks.stdin.write(line_str)
+    fix_stacks.stdin.flush()
+    out = fix_stacks.stdout.readline()
+    if is_missing_newline:
+        out = out[:-1]
+
+    if is_bytes and not isinstance(out, bytes):
+        out = out.encode("utf-8")
+    return out
+
+
+if __name__ == "__main__":
+    bpsyms = os.environ.get("BREAKPAD_SYMBOLS_PATH", None)
+    for line in sys.stdin:
+        sys.stdout.write(fixSymbols(line, breakpadSymsDir=bpsyms))