1 files changed, 52 insertions, 0 deletions
diff --git a/src/ci/scripts/should-skip-this.sh b/src/ci/scripts/should-skip-this.sh
new file mode 100755
index 000000000..c863f1b68
--- /dev/null
+++ b/src/ci/scripts/should-skip-this.sh
@@ -0,0 +1,52 @@
+#!/bin/bash
+# Set the SKIP_JOB environment variable if this job is supposed to only run
+# when submodules are updated and they were not. The following time consuming
+# tasks will be skipped when the environment variable is present.
+
+set -euo pipefail
+IFS=$'\n\t'
+
+source "$(cd "$(dirname "$0")" && pwd)/../shared.sh"
+
+if [[ -n "${CI_ONLY_WHEN_SUBMODULES_CHANGED-}" ]]; then
+    git fetch "https://github.com/$GITHUB_REPOSITORY" "$GITHUB_BASE_REF"
+    BASE_COMMIT="$(git merge-base FETCH_HEAD HEAD)"
+
+    echo "Searching for toolstate changes between $BASE_COMMIT and $(git rev-parse HEAD)"
+
+    if git diff "$BASE_COMMIT" | grep --quiet "^index .* 160000"; then
+        # Submodules pseudo-files inside git have the 160000 permissions, so when
+        # those files are present in the diff a submodule was updated.
+        echo "Submodules were updated"
+    elif ! git diff --quiet "$BASE_COMMIT" -- src/tools/clippy src/tools/rustfmt; then
+        # There is not an easy blanket search for subtrees. For now, manually list
+        # the subtrees.
+        echo "Clippy or rustfmt subtrees were updated"
+    elif ! (git diff --quiet "$BASE_COMMIT" -- \
+             src/test/rustdoc-gui \
+             src/librustdoc \
+             src/ci/docker/host-x86_64/x86_64-gnu-tools/Dockerfile \
+             src/ci/docker/host-x86_64/x86_64-gnu-tools/browser-ui-test.version \
+             src/tools/rustdoc-gui); then
+        # There was a change in either rustdoc or in its GUI tests.
+        echo "Rustdoc was updated"
+    else
+        echo "Not executing this job since no submodules nor subtrees were updated"
+        ciCommandSetEnv SKIP_JOB 1
+        exit 0
+    fi
+fi
+
+if [[ -n "${CI_ONLY_WHEN_CHANNEL-}" ]]; then
+    if [[ "${CI_ONLY_WHEN_CHANNEL}" = "$(cat src/ci/channel)" ]]; then
+        echo "The channel is the expected one"
+    else
+        echo "Not executing this job as the channel is not the expected one"
+        ciCommandSetEnv SKIP_JOB 1
+        exit 0
+    fi
+fi
+
+
+echo "Executing the job since there is no skip rule preventing the execution"
+exit 0