testing/mozbase/mozleak/mozleak/lsan.py
author Lee Salzman <lsalzman@mozilla.com>
Sat, 28 Jan 2023 11:24:54 +0000
changeset 650885 f4f63f0138feb7535fa58c3f77fd8a51361371d8
parent 647332 8e89f8e20ad6336c3cbb4d895d36077e46f6489b
permissions -rw-r--r--
Bug 1812970 - Avoid using Skia's deprecated clip ops. r=jrmuizel Skia upstream removed deprecated clip ops that could be used to replace the clipping stack and bypass clips. We shouldn't really need to do this anymore, as we can work around it just using public APIs. The only SkCanvas operation that allows us to bypass clipping is writePixels, which still allows us to implement CopySurface/putImageData. Other instances where we were using the replace op for DrawTargetWebgl layering support can just be worked around by creating a separate DrawTargetSkia pointing to the same pixel data, but on which no clipping or transforms are applied so that we can freely do drawing operations on it to the base layer pixel data regardless of any user-applied clipping. Differential Revision: https://phabricator.services.mozilla.com/D168039

# 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/.

import re


class LSANLeaks(object):

    """
    Parses the log when running an LSAN build, looking for interesting stack frames
    in allocation stacks
    """

    def __init__(
        self,
        logger,
        scope=None,
        allowed=None,
        maxNumRecordedFrames=None,
        allowAll=False,
    ):
        self.logger = logger
        self.inReport = False
        self.fatalError = False
        self.symbolizerError = False
        self.foundFrames = set()
        self.recordMoreFrames = None
        self.currStack = None
        self.maxNumRecordedFrames = maxNumRecordedFrames if maxNumRecordedFrames else 4
        self.summaryData = None
        self.scope = scope
        self.allowedMatch = None
        self.allowAll = allowAll
        self.sawError = False

        # Don't various allocation-related stack frames, as they do not help much to
        # distinguish different leaks.
        unescapedSkipList = [
            "malloc",
            "js_malloc",
            "malloc_",
            "__interceptor_malloc",
            "moz_xmalloc",
            "calloc",
            "js_calloc",
            "calloc_",
            "__interceptor_calloc",
            "moz_xcalloc",
            "realloc",
            "js_realloc",
            "realloc_",
            "__interceptor_realloc",
            "moz_xrealloc",
            "new",
            "js::MallocProvider",
        ]
        self.skipListRegExp = re.compile(
            "^" + "|".join([re.escape(f) for f in unescapedSkipList]) + "$"
        )

        self.startRegExp = re.compile(
            "==\d+==ERROR: LeakSanitizer: detected memory leaks"
        )
        self.fatalErrorRegExp = re.compile(
            "==\d+==LeakSanitizer has encountered a fatal error."
        )
        self.symbolizerOomRegExp = re.compile(
            "LLVMSymbolizer: error reading file: Cannot allocate memory"
        )
        self.stackFrameRegExp = re.compile("    #\d+ 0x[0-9a-f]+ in ([^(</]+)")
        self.sysLibStackFrameRegExp = re.compile(
            "    #\d+ 0x[0-9a-f]+ \(([^+]+)\+0x[0-9a-f]+\)"
        )
        self.summaryRegexp = re.compile(
            "SUMMARY: AddressSanitizer: (\d+) byte\(s\) leaked in (\d+) allocation\(s\)."
        )
        self.rustRegexp = re.compile("::h[a-f0-9]{16}$")
        self.setAllowed(allowed)

    def setAllowed(self, allowedLines):
        if not allowedLines or self.allowAll:
            self.allowedRegexp = None
        else:
            self.allowedRegexp = re.compile(
                "^" + "|".join([re.escape(f) for f in allowedLines])
            )

    def log(self, line):
        if re.match(self.startRegExp, line):
            self.inReport = True
            # Downgrade this from an ERROR
            self.sawError = True
            return "LeakSanitizer: detected memory leaks"

        if re.match(self.fatalErrorRegExp, line):
            self.fatalError = True
            return line

        if re.match(self.symbolizerOomRegExp, line):
            self.symbolizerError = True
            return line

        if not self.inReport:
            return line

        if line.startswith("Direct leak") or line.startswith("Indirect leak"):
            self._finishStack()
            self.recordMoreFrames = True
            self.currStack = []
            return line

        summaryData = self.summaryRegexp.match(line)
        if summaryData:
            assert self.summaryData is None
            self._finishStack()
            self.inReport = False
            self.summaryData = (int(item) for item in summaryData.groups())
            # We don't return the line here because we want to control whether the
            # leak is seen as an expected failure later
            return

        if not self.recordMoreFrames:
            return line

        stackFrame = re.match(self.stackFrameRegExp, line)
        if stackFrame:
            # Split the frame to remove any return types.
            frame = stackFrame.group(1).split()[-1]
            if not re.match(self.skipListRegExp, frame):
                self._recordFrame(frame)
            return line

        sysLibStackFrame = re.match(self.sysLibStackFrameRegExp, line)
        if sysLibStackFrame:
            # System library stack frames will never match the skip list,
            # so don't bother checking if they do.
            self._recordFrame(sysLibStackFrame.group(1))

        # If we don't match either of these, just ignore the frame.
        # We'll end up with "unknown stack" if everything is ignored.
        return line

    def process(self):
        failures = 0

        if self.allowAll:
            self.logger.info("LeakSanitizer | Leak checks disabled")
            return

        if self.summaryData:
            allowed = all(allowed for _, allowed in self.foundFrames)
            self.logger.lsan_summary(*self.summaryData, allowed=allowed)
            self.summaryData = None

        if self.fatalError:
            self.logger.error(
                "LeakSanitizer | LeakSanitizer has encountered a fatal error."
            )
            failures += 1

        if self.symbolizerError:
            self.logger.error(
                "LeakSanitizer | LLVMSymbolizer was unable to allocate memory.\n"
                "This will cause leaks that "
                "should be ignored to instead be reported as an error"
            )
            failures += 1

        if self.foundFrames:
            self.logger.info(
                "LeakSanitizer | To show the "
                "addresses of leaked objects add report_objects=1 to LSAN_OPTIONS\n"
                "This can be done in testing/mozbase/mozrunner/mozrunner/utils.py"
            )
            self.logger.info("Allowed depth was %d" % self.maxNumRecordedFrames)

            for frames, allowed in self.foundFrames:
                self.logger.lsan_leak(frames, scope=self.scope, allowed_match=allowed)
                if not allowed:
                    failures += 1

        if self.sawError and not (
            self.summaryData
            or self.foundFrames
            or self.fatalError
            or self.symbolizerError
        ):
            self.logger.error(
                "LeakSanitizer | Memory leaks detected but no leak report generated"
            )

        self.sawError = False

        return failures

    def _finishStack(self):
        if self.recordMoreFrames and len(self.currStack) == 0:
            self.currStack = {"unknown stack"}
        if self.currStack:
            self.foundFrames.add((tuple(self.currStack), self.allowedMatch))
            self.currStack = None
            self.allowedMatch = None
        self.recordMoreFrames = False
        self.numRecordedFrames = 0

    def _recordFrame(self, frame):
        if self.allowedMatch is None and self.allowedRegexp is not None:
            self.allowedMatch = frame if self.allowedRegexp.match(frame) else None
        frame = self._cleanFrame(frame)
        self.currStack.append(frame)
        self.numRecordedFrames += 1
        if self.numRecordedFrames >= self.maxNumRecordedFrames:
            self.recordMoreFrames = False

    def _cleanFrame(self, frame):
        # Rust frames aren't properly demangled and in particular can contain
        # some trailing junk of the form ::h[a-f0-9]{16} that changes with
        # compiler versions; see bug 1507350.
        return self.rustRegexp.sub("", frame)