This repository contains a version of Valgrind including a few patches to improve support for the macOS platform. It is maintained by Louis Brunner.

In case you already have Valgrind installed, you might need to brew remove it first.

In order to use this version, first tap this repository:

brew tap LouisBrunner/valgrind

Then, install valgrind:

brew install --HEAD LouisBrunner/valgrind/valgrind

It is possible that Homebrew shows you the following error message afterwards:

error: Invalid usage: --HEAD is not supported with HOMEBREW_NO_INSTALL_FROM_API unset! To resolve please run:
  export HOMEBREW_NO_INSTALL_FROM_API=1
  brew tap Homebrew/core
and retry this command.

If so, just execute both commands and retry the installation as mentioned above.

You can now use valgrind as normal.

Note: in case of failures during the build, make sure you have the latest Xcode/CLI tools installed.

Any brew upgrade will now correctly rebuild the latest LouisBrunner/valgrind instead of the upstream one (which doesn't support the latest macOS versions).

brew upgrade --fetch-HEAD LouisBrunner/valgrind/valgrind

These errors seem to come from the CI environment itself (as they show with or without my changes).

== 857 tests, 20 stderr failures, 1 stdout failure, 0 stderrB failures, 0 stdoutB failures, 0 post failures ==
none/tests/fdleak_cmsg                   (stderr)
none/tests/fdleak_cmsg_supp              (stderr)
none/tests/fdleak_cmsg_xml               (stderr)
none/tests/fdleak_creat                  (stderr)
none/tests/fdleak_creat_sup              (stderr)
none/tests/fdleak_creat_xml              (stderr)
none/tests/fdleak_dup                    (stderr)
none/tests/fdleak_dup2                   (stderr)
none/tests/fdleak_dup2_xml               (stderr)
none/tests/fdleak_dup_xml                (stderr)
none/tests/fdleak_fcntl                  (stderr)
none/tests/fdleak_fcntl_xml              (stderr)
none/tests/fdleak_ipv4                   (stderr)
none/tests/fdleak_open                   (stderr)
none/tests/fdleak_pipe                   (stderr)
none/tests/fdleak_socketpair             (stderr)
none/tests/linux/getdents_filter         (stdout)
none/tests/rlimit64_nofile               (stderr)
none/tests/rlimit_nofile                 (stderr)
none/tests/track_high                    (stderr)
none/tests/track_yes                     (stderr)

should be (according to the official Fedora x86_64 builds)

== 835 tests, 4 stderr failures, 0 stdout failures, 0 stderrB failures, 0 stdoutB failures, 0 post failures ==
memcheck/tests/descr_belowsp             (stderr)
helgrind/tests/tc22_exit_w_lock          (stderr)
drd/tests/std_thread2                    (stderr)
drd/tests/tls_threads                    (stderr)

See here for details.

See the macos-VERSION-expected.txt in .github/ for more details about which tests pass on which version.

Some tests are a bit flaky and might fail randomly, see .github/flaky-tests.txt for more details.

Valgrind is a very thorough program and can often report false positives. There are wide range of reasons why those come up (e.g. Valgrind not tracking some OS-specific part of the memory). Moreover, Valgrind might also report issues inside standard libraries, which are relevant for maintainers of such projects, but not to the end-user.

While fixing those issues would be better, it isn't always possible. This is why Valgrind supports a system called "suppressions", which is a special file format instructing which errors to ignore so the end-user doesn't see them.

Because some of those errors only show in special conditions, you might be asked to provide a "suppressions" file to be added to the repository. You can also keep those local to the project you are debugging and use them when running Valgrind.

To create a "suppressions" file, simply run:

valgrind YOUR_VALGRIND_OPTIONS --gen-suppressions=all YOUR_PROGRAM YOUR_PROGRAM_ARGS
# for example:
valgrind --trace-syscalls=yes --gen-suppressions=all ls -la
# if you want to choose on a case-by-case basis instead of generating all the suppressions, you can do:
valgrind --trace-syscalls=yes --gen-suppressions=yes ls -la

You will then see a few extra entries in your output, they will look something like that:

{
   <insert_a_suppression_name_here>
   Memcheck:Cond
   fun:_platform_strlen
   fun:_mh_execute_header
   fun:(below main)
}

or

{
   <insert_a_suppression_name_here>
   Memcheck:Param
   write(buf)
   fun:write$NOCANCEL
   obj:/dev/ttys002
   fun:_swrite
   fun:__sflush
   fun:__sfvwrite
   fun:puts
   fun:_mh_execute_header
   fun:(below main)
}

You can then add them to a new file, e.g. one called my.supp, replace the name <insert_a_suppression_name_here> with a description of the issue for later use. You can also use # to comment out lines, for documentation or disabling specific suppressions. Check any of the .supp files in this repository for examples, e.g. darwin19.supp.

• tyrael9: for their work around porting Valgrind to iOS armv7 which was used as part of the port to arm64 (see here)