CI check against Rust feature bleed

scripts/ci/gitlab/pipeline/check.yml

@@ -35,6 +35,15 @@ test-dependency-rules:
   script:
     - ./scripts/ci/gitlab/ensure-deps.sh
 
+test-rust-features:
+  stage:                           check
+  extends:
+    - .kubernetes-env
+    - .test-refs-no-trigger-prs-only
+  script:
+    - cargo install --git https://github.com/pksunkara/cargo-workspaces --tag v0.2.35 --force cargo-workspaces
+    - bash ./scripts/ci/gitlab/rust-features.sh .
+
 test-prometheus-alerting-rules:
   stage:                           check
   extends:                         .kubernetes-env

scripts/ci/gitlab/rust-features.sh

@@ -0,0 +1,111 @@
+#!/bin/bash
+
+# This file is part of Substrate.
+# Copyright (C) 2022 Parity Technologies (UK) Ltd.
+# SPDX-License-Identifier: Apache-2.0
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+#######################################################################
+#
+# This script checks that no crate enables a specific feature in its
+# `default` feature set. It's important to check that since features
+# are used to gate specific functionality which should only be enabled
+# if the feature is present.
+#
+# Has `cargo-workspaces` as optional dependency:
+# https://github.com/pksunkara/cargo-workspaces
+#
+# Invocation scheme:
+# 	./rust-features.sh <CARGO-ROOT-PATH>
+#
+# The steps of this script:
+#   1. Check that all required dependencies are installed.
+#   2. Check that all rules are fullfilled for the whole workspace. If not:
+#   3. Print an error and check if `cargo-workspaces` is installed. If so:
+#   4. List all crates and go through each one to find the offending crate.
+#   5. Print all offending crates and exit with failure.
+#
+#######################################################################
+
+set -eu
+
+# Check that cargo, grep and egrep are installed.
+command -v cargo >/dev/null 2>&1 || { echo >&2 "cargo is required but not installed. Aborting."; exit 1; }
+command -v grep >/dev/null 2>&1 || { echo >&2 "grep is required but not installed. Aborting."; exit 1; }
+command -v egrep >/dev/null 2>&1 || { echo >&2 "egrep is required but not installed. Aborting."; exit 1; }
+
+SUBSTRATE_ROOT=$1
+declare -a RULES=(
+	"default,std never implies runtime-benchmarks"
+	"default,std never implies try-runtime"
+)
+
+function check_does_not_imply() {
+	ENABLED=$1
+	STAYS_DISABLED=$2
+	echo "📏 Checking that '$ENABLED' does not imply '$STAYS_DISABLED'"
+
+	RET=0
+	# Check if the forbidden feature is enabled anywhere in the workspace.
+	cargo tree --no-default-features --locked --workspace -e features --features "$ENABLED" | grep -q "feature \"$STAYS_DISABLED\"" || RET=$?
+	if [ $RET -ne 0 ]; then
+		echo "✅ Feature '$ENABLED' does not imply '$STAYS_DISABLED' in the workspace"
+		return
+	else
+		echo "❌ Feature '$ENABLED' implies '$STAYS_DISABLED' in the workspace"
+	fi
+
+	# Check if `cargo-workspaces` is installed.
+	# If not, the user only gets a generic error instead of a nicer one.
+	if ! cargo workspaces --version > /dev/null 2>&1; then
+		echo "❌ Install 'cargo-workspaces' for a more detailed error message."
+		exit 1
+	fi
+
+	CRATES=`cargo workspaces list --all | egrep -o '^(\w|-)+'`
+	FAILED=0
+	PASSED=0
+	echo "🔍 Checking individual crates"
+
+	for CRATE in $CRATES; do
+		RET=0
+		OUTPUT=$(cargo tree --no-default-features --locked -e features --features $ENABLED -p $CRATE 2>&1 || true)
+		IS_NOT_SUPPORTED=$(echo $OUTPUT | grep -q "not supported for packages in this workspace" || echo $?)
+
+		if [ $IS_NOT_SUPPORTED -eq 0 ]; then
+			# This case just means that the pallet does not support the
+			# requested feature which is fine.
+			PASSED=$((PASSED+1))
+		elif echo "$OUTPUT" | grep -q "feature \"$STAYS_DISABLED\""; then
+			echo "❌ Feature '$ENABLED' implies '$STAYS_DISABLED' in $CRATE; enabled by"
+			echo "$OUTPUT" | grep -w "feature \"$STAYS_DISABLED\"" | head -n 1
+			FAILED=$((FAILED+1))
+		else
+			PASSED=$((PASSED+1))
+		fi
+	done
+
+	TOTAL=$((PASSED + FAILED))
+	echo "Checked $TOTAL crates in total of which $FAILED failed and $PASSED passed."
+
+	if [ $FAILED -ne 0 ]; then
+		exit 1
+	fi
+}
+
+cd "$SUBSTRATE_ROOT"
+
+for RULE in "${RULES[@]}"; do
+    read -a splits <<< "$RULE"
+	check_does_not_imply "${splits[0]}" "${splits[3]}"
+done