ci: add tool to check for Cargo features

When running tests from .travis.yml, the passed in features are first
checked locally for support in the current simulator. The list of
supported features was manually maintained, allowing newly implemented
features to be skipped, also skipping the related test (without
warnings). This adds a new tool that parses and prints the list of
features directly from the given Cargo.toml.

Signed-off-by: Fabio Utzig <utzig@apache.org>

.travis.yml

@@ -1,5 +1,10 @@
 # Travis configuration.  Build the simulator and run its tests.
 
+addons:
+  apt:
+    packages:
+      - "python3-pip"
+
 language: rust
 
 cache:

ci/get_features.py

@@ -0,0 +1,40 @@
+#!/usr/bin/env python3
+
+# Copyright 2020 JUUL Labs
+#
+# 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.
+
+import argparse
+import os.path
+import toml
+
+parser = argparse.ArgumentParser(description='Print features from a Cargo.toml.')
+parser.add_argument('infile', help='Input file to parse')
+
+args = parser.parse_args()
+if not os.path.isfile(args.infile):
+    print("File not found")
+    exit(1)
+
+try:
+    cargo_toml = open(args.infile).read()
+except Exception:
+    print("Error reading \"{}\"".format(args.infile))
+    exit(1)
+
+config = toml.loads(cargo_toml)
+if 'features' not in config:
+    print("Missing \"[features]\" section")
+    exit(1)
+
+print(" ".join([k for k in config['features'] if k != 'default']))

ci/requirements.txt

@@ -0,0 +1 @@
+toml

ci/sim_install.sh

@@ -12,6 +12,8 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+pip3 install --user -r ci/requirements.txt
+
 pushd sim && cargo fetch
 [[ $? -ne 0 ]] && exit 1
 popd

ci/sim_run.sh

@@ -12,13 +12,17 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+GET_FEATURES="$(pwd)/ci/get_features.py"
+CARGO_TOML="$(pwd)/sim/Cargo.toml"
+
 pushd sim
 
+all_features="$(${GET_FEATURES} ${CARGO_TOML})"
+[ $? -ne 0 ] && exit 1
+
 EXIT_CODE=0
 
 if [[ ! -z $SINGLE_FEATURES ]]; then
-  all_features="sig-rsa sig-ecdsa overwrite-only validate-primary-slot enc-rsa enc-kw bootstrap"
-
   if [[ $SINGLE_FEATURES =~ "none" ]]; then
     echo "Running cargo with no features"
     cargo test