add a simple GitHub Actions CI workflow

.github/workflows/ci.yml

@@ -0,0 +1,92 @@
+name: CI
+on:
+  pull_request:
+  push:
+    branches: [main]
+
+env:
+  # disable incremental compilation.
+  #
+  # incremental compilation is useful as part of an edit-build-test-edit cycle,
+  # as it lets the compiler avoid recompiling code that hasn't changed. however,
+  # on CI, we're not making small edits; we're almost always building the entire
+  # project from scratch. thus, incremental compilation on CI actually
+  # introduces *additional* overhead to support making future builds
+  # faster...but no future builds will ever occur in any given CI environment.
+  #
+  # see https://matklad.github.io/2021/09/04/fast-rust-builds.html#ci-workflow
+  # for details.
+  CARGO_INCREMENTAL: 0
+  # allow more retries for network requests in cargo (downloading crates) and
+  # rustup (installing toolchains). this should help to reduce flaky CI failures
+  # from transient network timeouts or other issues.
+  CARGO_NET_RETRY: 10
+  RUSTUP_MAX_RETRIES: 10
+
+jobs:
+  check-idol:
+    name: Check idol codegen
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        rust:
+        - "stable"
+        # the current pinned Rust toolchain in the Hubris repo:
+        # https://github.com/oxidecomputer/hubris/blob/master/rust-toolchain.toml
+        #
+        # when updating Hubris' Rust toolchain, make sure to update this, too!
+        # TODO(eliza): it would be nice to determine this automatically...
+        - "nightly-2022-11-01"
+    steps:
+    - uses: actions/checkout@v2
+    - uses: actions-rs/toolchain@v1
+      with:
+        profile: minimal
+        toolchain: ${{ matrix.rust }}
+        override: true
+    - uses: Swatinem/rust-cache@v1
+    - run: cargo check -p idol
+
+  check-runtime:
+    name: Check idol-runtime
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        rust:
+        # the current pinned Rust toolchain in the Hubris repo:
+        # https://github.com/oxidecomputer/hubris/blob/master/rust-toolchain.toml
+        #
+        # when updating Hubris' Rust toolchain, make sure to update this, too!
+        # TODO(eliza): it would be nice to determine this automatically...
+        - "nightly-2022-11-01"
+        target:
+        - "thumbv6m-none-eabi"
+        - "thumbv7em-none-eabihf"
+        - "thumbv8m.main-none-eabihf"
+    steps:
+    - uses: actions/checkout@v2
+    - uses: actions-rs/toolchain@v1
+      with:
+        profile: minimal
+        toolchain: ${{ matrix.rust }}
+        target: ${{ matrix.target }}
+        override: true
+    - uses: Swatinem/rust-cache@v1
+    - run: cargo check -p idol-runtime --target ${{ matrix.target }}
+
+  rustfmt:
+    name: rustfmt
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        rust:
+        - "stable"
+    steps:
+    - uses: actions/checkout@v2
+    - uses: actions-rs/toolchain@v1
+      with:
+        profile: minimal
+        toolchain: ${{ matrix.rust }}
+        override: true
+    - uses: Swatinem/rust-cache@v1
+    - run: cargo fmt --check

.github/workflows/license-check.yml

@@ -0,0 +1,9 @@
+name: license-check
+on: pull_request
+jobs:
+  license:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@master
+    - name: Check License Header
+      uses: apache/skywalking-eyes/header@501a28d2fb4a9b962661987e50cf0219631b32ff

runtime/src/lib.rs

@@ -1,3 +1,7 @@
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at https://mozilla.org/MPL/2.0/.
+
 #![no_std]
 
 //! Runtime support types for code generated by the Idol compiler.

src/bin/servertest.rs

@@ -1,3 +1,7 @@
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at https://mozilla.org/MPL/2.0/.
+
 use std::io::Read;
 
 fn main() -> Result<(), Box<dyn std::error::Error + Send + Sync>> {

src/counters.rs

@@ -1,3 +1,7 @@
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at https://mozilla.org/MPL/2.0/.
+
 use crate::syntax;
 use proc_macro2::TokenStream;
 use quote::quote;

src/server.rs

@@ -107,8 +107,10 @@ impl Generator {
         Ok(tokens)
     }
 
-
-    pub fn generate_server_constants(&self, iface: &syntax::Interface) -> TokenStream {
+    pub fn generate_server_constants(
+        &self,
+        iface: &syntax::Interface,
+    ) -> TokenStream {
         // Generate message sizing constants for each message.
         let mut msgsize_names = Vec::with_capacity(iface.ops.len());
         let consts = iface.ops.iter().map(|(name, op)| {
@@ -202,7 +204,10 @@ impl Generator {
         }
     }
 
-    pub fn generate_server_conversions(&self, iface: &syntax::Interface) -> TokenStream {
+    pub fn generate_server_conversions(
+        &self,
+        iface: &syntax::Interface,
+    ) -> TokenStream {
         let conversions = iface.ops.iter().map(|(name, op)| {
             // Define args struct.
                 let attrs = match op.encoding {
@@ -296,7 +301,7 @@ impl Generator {
                 } else {
                     quote! {}
                 };
-    
+
                 let read_fn = {
                     let read_fn = format_ident!("read_{}_msg", name);
                     match op.encoding {
@@ -361,7 +366,10 @@ impl Generator {
         }
     }
 
-    pub fn generate_server_op_impl(&self, iface: &syntax::Interface) -> TokenStream {
+    pub fn generate_server_op_impl(
+        &self,
+        iface: &syntax::Interface,
+    ) -> TokenStream {
         let op_enum = iface.name.as_op_enum();
         let max_reply_size_cases = iface.ops.keys().map(|opname| {
             let reply_size = opname.as_reply_size();
@@ -743,7 +751,7 @@ fn generate_trait_def(
                 quote! { Result<#ok, idol_runtime::RequestError<#err_ty>> }
             },
             syntax::Reply::Simple(t) => {
-                quote! { 
+                quote! {
                     Result<#t, idol_runtime::RequestError<core::convert::Infallible>>
                 }
             },