Have you ever got into the situation that after you fixed memory leaks with Valgrind you see Definitely lost again after a while? Then this CI setup may be useful for you.

You can do it in 3 steps:

• Install Valgrind in your CI environment.
• Run tests with Valgrind and output results to XML.
• Add script to parse XML and report errors.
• You may also want to control when to run it. Running with Valgrind may be time-consuming, so you may want to run it only on Pull Requests to the master branch. Or you may want to run it only for some specific tests.

These steps are common for every possible CI. Let’s see it on GitHub Actions example.

💡 If you did not work with GitHub Actions before, see Quickstart for GitHub Actions.

Add Valgrind install step to yml file

- name: Install Valgrind
  run: |
    sudo apt install valgrind
    echo "Valgrind installed"

You can run into the issue that Valgrind version is not compatible with your CI system. Then you will need to build and install another version of Valgrind: here is an example of how to do it.

Update test’s run script to run with Valgrind

- name: Install Valgrind
  run: |
    sudo apt install valgrind
    echo "Valgrind installed"

--suppressions=./path/to/suppresion/my_app.supp - this option is needed only if you have suppression file. You can generate suppressions for the errors for the libraries, but it’s not a good practice. It's hard to know if a memory error in the library is caused by a problem in your code or not. But if it is not possible to fix a leak, and you are sure it’s not your leak, then 1) suppress errors from the library (short-term solution); 2) upgrade the library or connect the community who supports it and ask for a fix. Example of the first option. Ignore Leak errors in libcrypto only, you could put a suppression like:

{
   ignore_libcrypto_conditional_jump_errors
   Memcheck:Leak
   ...
   obj:*/libcrypto.so.*
}

into a file and pass it to valgrind with --suppressions=./path/to/suppresion/my_app.supp. You can also let Valgrind generate suppression file for you. Use -gen-suppressions=yes from Core Command-line Options.

--xml=yes --xml-file=unit_tests_valgrind.xml - enable Valgrind’s to report in XML format and save it in unit_tests_valgrind.xml.

Parse XML output

You can write your own using ValgrindCI tool or write a custom XML parser.

ValgrindCI tool

- name: Valgrind Memory check
       run: |
           pip install ValgrindCI
           echo "Summary report of errors"
           valgrind-ci /path/to/output_file.xml --summary
           valgrind-ci /path/to/output_file.xml --abort-on-errors # abort on errors

Custom XML parser in Bash

The output XML format is specified in the file docs/internals/xml-output-protocol4.txt in the source tree for Valgrind 3.5.0 or later. It has errorcounts or error tags to report errors:

ERROR definition -- common structure
------------------------------------
ERROR defines an error, and is the most complex nonterminal. For all
of the tools, the structure is common, and always conforms to the
following:
<error>
    <unique>HEX64</unique>
    <tid>INT</tid>
    <threadname>NAME</threadname> if set
    <kind>KIND</kind>
    ...
    optionally: SUPPRESSION
</error>
* Each error contains a unique, arbitrary 64-bit hex number. This is
used to refer to the error in ERRORCOUNTS nonterminals (see above).

It’s enough to check if /ERROR tag exists to know if at least one error was reported. But it’s more secure to parse all tags and return the exact number of errors and short summary.

# Check if the xml has any "</errorcounts>" attributes. If it has, memory errors exists.
sed 's/"/ /g' < $xml_file | grep '</error>' &> /dev/null
if [ $? == 0 ]; then
    printf "%s" "$boldred"
    echo "[  FAILED  ] Some memory checks failed for $xml_file."
    error=-1
        exit $error;
else
    echo "[  SUCCESS  ]"
fi

yml step:

- name: Valgrind Memory check
  run: |
    echo "Checking Valgrind xmls ..."
    ./check-memory.sh

It is good to use a custom script if you need to parse a few XML’s and report separately on each.

Example of how to control Valgrind run with environment variable

RUN_MEMORY_CHECK - environment variable to control when to run Valgrind memory check. In the example below, it will run memory check steps only for main branch or if RUN_MEMORY_CHECK is added to GitHub Actions Secrets and is set to true

name: "Build and run tests with memory check"

on:
  pull_request:
  push:
    branches:
      - main      
            - dev

env:
  RUN_MEMORY_CHECK: ${{ (github.base_ref == 'main') || ((secrets.RUN_MEMORY_CHECK == 'true') }}
jobs:
  build:
    name: "Build"
    runs-on: ubuntu-latest
    strategy:
      fail-fast: false
      matrix:
        include:
          - target: x86_64

    steps:
      - uses: actions/checkout@v2
      - name: Set up environment
        run: |
          sudo apt update
          sudo apt install -y libev-dev
      - name: Install Valgrind
        if: ${{ env.RUN_MEMORY_CHECK == 'true' }}
        run: |
          sudo apt install valgrind
          echo "Valgrind installed"

      - name: Build Tests
        run: |
          # add build script execution here

      - name: Run Tests with Valgrind
        run: |
                    valgrind --leak-check=full --suppressions=./path/to/suppresion/my_app.supp --xml=yes --xml-file=unit_tests_valgrind.xml ./unit_tests_binary

      - name: Valgrind Memory check
        if: ${{ env.RUN_MEMORY_CHECK == 'true' }}
        run: |
          echo "Checking Valgrind xml ..."
            ./check-memory.sh

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