From c61845ed45b7e90de637debf96c3e86a8180c504 Mon Sep 17 00:00:00 2001
From: Giles Cope <gilescope@gmail.com>
Date: Thu, 21 May 2026 09:29:23 +0100
Subject: [PATCH] valgrind example

---
 docs/examples/examples.md |  2 +-
 examples/README.md        |  2 +-
 examples/c/Earthfile      | 42 ++++++++++++++++++++++++++++++++++++---
 3 files changed, 41 insertions(+), 5 deletions(-)

diff --git a/docs/examples/examples.md b/docs/examples/examples.md
index 8e0da04700..a14e595ad5 100644
--- a/docs/examples/examples.md
+++ b/docs/examples/examples.md
@@ -42,7 +42,7 @@ Please note that these examples, although similar, are distinct from the ones us
 
 <!-- vale HouseStyle.Spelling = NO -->
 
-- [c](https://github.com/earthbuild/earthbuild/tree/main/examples/c)
+- [c](https://github.com/earthbuild/earthbuild/tree/main/examples/c) - also demonstrates running `valgrind` inside earthbuild, useful on macOS / Windows where valgrind isn't available natively.
 - [clojure](https://github.com/earthbuild/earthbuild/tree/main/examples/clojure)
 - [cobol](https://github.com/earthbuild/earthbuild/tree/main/examples/cobol)
 - [cpp](https://github.com/earthbuild/earthbuild/tree/main/examples/cpp)
diff --git a/examples/README.md b/examples/README.md
index a53c50cc1d..6501b951ba 100644
--- a/examples/README.md
+++ b/examples/README.md
@@ -23,7 +23,7 @@ Please note that these examples, although similar, are distinct from the ones us
 <!-- vale HouseStyle.Spelling = NO -->
 - [clojure](./clojure)
 - [cobol](./cobol)
-- [c](./c)
+- [c](./c) - also demonstrates running `valgrind` inside earthbuild, useful on macOS / Windows where valgrind isn't available natively.
 - [cpp](./cpp)
 - [dotnet](./dotnet)
 - [elixir](./elixir)
diff --git a/examples/c/Earthfile b/examples/c/Earthfile
index 6f1d841076..97e54e0547 100644
--- a/examples/c/Earthfile
+++ b/examples/c/Earthfile
@@ -1,9 +1,18 @@
 VERSION 0.8
-FROM alpine:3.23.3
+
+# renovate: datasource=docker packageName=alpine
+ARG --global alpine_version=3.23.3
+FROM alpine:$alpine_version
 WORKDIR /c-example
 
 deps:
-    RUN apk --update add build-base cmake
+    # renovate: datasource=repology depName=alpine_3_23/build-base versioning=loose
+    ARG build_base_version=0.5-r3
+    # renovate: datasource=repology depName=alpine_3_23/cmake versioning=loose
+    ARG cmake_version=4.1.3-r0
+    RUN apk --update add \
+            build-base=$build_base_version \
+            cmake=$cmake_version
 
 build:
     FROM +deps
@@ -19,14 +28,41 @@ docker:
 
 unit-test:
     FROM +deps
-    RUN apk add cunit-dev
+    # renovate: datasource=repology depName=alpine_3_23/cunit-dev versioning=loose
+    ARG cunit_dev_version=2.1.3-r7
+    RUN apk add cunit-dev=$cunit_dev_version
     COPY src src
     COPY test test
     RUN cmake test
     RUN make
     RUN ./unit-test
 
+# memcheck runs the unit-test binary under valgrind's memcheck tool to detect
+# leaks, invalid reads/writes, and uninitialised reads. Built with -g -O0 so
+# stack traces resolve to source lines.
+memcheck:
+    FROM +deps
+    # renovate: datasource=repology depName=alpine_3_23/cunit-dev versioning=loose
+    ARG cunit_dev_version=2.1.3-r7
+    # renovate: datasource=repology depName=alpine_3_23/valgrind versioning=loose
+    ARG valgrind_version=3.25.1-r2
+    RUN apk add \
+            cunit-dev=$cunit_dev_version \
+            valgrind=$valgrind_version
+    COPY src src
+    COPY test test
+    RUN cmake -DCMAKE_C_FLAGS="-g -O0" test
+    RUN make
+    RUN valgrind \
+            --error-exitcode=1 \
+            --leak-check=full \
+            --show-leak-kinds=all \
+            --errors-for-leak-kinds=definite \
+            --track-origins=yes \
+            ./unit-test
+
 all:
     BUILD +build
     BUILD +unit-test
+    BUILD +memcheck
     BUILD +docker