Automatically creates PR when no_atomic_cas.rs needs to be updated

.github/workflows/ci.yml

@@ -231,17 +231,40 @@ jobs:
             --features unstable --ignore-unknown-features
 
   # When this job failed, run ci/no_atomic_cas.sh and commit result changes.
-  # TODO(taiki-e): Ideally, this should be automated using a bot that creates
-  #                PR when failed, but there is no bandwidth to implement it
-  #                right now...
   codegen:
     runs-on: ubuntu-latest
+    permissions:
+      contents: write
+      pull-requests: write
     steps:
       - uses: actions/checkout@v2
       - name: Install Rust
         run: rustup update nightly && rustup default nightly
       - run: ci/no_atomic_cas.sh
-      - run: git diff --exit-code
+      - run: git add -N . && git diff --exit-code
+        if: github.event_name != 'schedule'
+      - id: diff
+        run: |
+          git config user.name "Taiki Endo"
+          git config user.email "te316e89@gmail.com"
+          git add -N .
+          if ! git diff --exit-code; then
+              git add .
+              git commit -m "Update no_atomic_cas.rs"
+              echo "::set-output name=success::false"
+          fi
+        if: github.event_name == 'schedule'
+      - uses: peter-evans/create-pull-request@v3
+        with:
+          title: Update no_atomic_cas.rs
+          body: |
+            Auto-generated by [create-pull-request][1]
+            [Please close and immediately reopen this pull request to run CI.][2]
+
+            [1]: https://github.com/peter-evans/create-pull-request
+            [2]: https://github.com/peter-evans/create-pull-request/blob/HEAD/docs/concepts-guidelines.md#workarounds-to-trigger-further-workflow-runs
+          branch: update-no-atomic-cas-rs
+        if: github.event_name == 'schedule' && steps.diff.outputs.success == 'false'
 
   miri:
     name: cargo miri test

ci/no_atomic_cas.sh

@@ -1,28 +1,31 @@
 #!/bin/bash
+set -euo pipefail
+IFS=$'\n\t'
+cd "$(dirname "$0")"/..
 
 # Update the list of targets that do not support atomic CAS operations.
 #
 # Usage:
 #    ./ci/no_atomic_cas.sh
 
-set -euo pipefail
-IFS=$'\n\t'
-
-cd "$(cd "$(dirname "$0")" && pwd)"/..
-
 file="no_atomic_cas.rs"
 
-{
-    echo "// This file is @generated by $(basename "$0")."
-    echo "// It is not intended for manual editing."
-    echo ""
-    echo "const NO_ATOMIC_CAS_TARGETS: &[&str] = &["
-} >"$file"
-
+no_atomic_cas=()
 for target in $(rustc --print target-list); do
-    res=$(rustc --print target-spec-json -Z unstable-options --target "$target" \
-        | jq -r "select(.\"atomic-cas\" == false)")
-    [[ -z "$res" ]] || echo "    \"$target\"," >>"$file"
+    target_spec=$(rustc --print target-spec-json -Z unstable-options --target "${target}")
+    res=$(jq <<<"${target_spec}" -r 'select(."atomic-cas" == false)')
+    [[ -z "${res}" ]] || no_atomic_cas+=("${target}")
 done
 
-echo "];" >>"$file"
+cat >"${file}" <<EOF
+// This file is @generated by $(basename "$0").
+// It is not intended for manual editing.
+
+const NO_ATOMIC_CAS: &[&str] = &[
+EOF
+for target in "${no_atomic_cas[@]}"; do
+    echo "    \"${target}\"," >>"${file}"
+done
+cat >>"${file}" <<EOF
+];
+EOF

futures-channel/build.rs

@@ -1,9 +1,3 @@
-#![warn(rust_2018_idioms, single_use_lifetimes)]
-
-use std::env;
-
-include!("no_atomic_cas.rs");
-
 // The rustc-cfg listed below are considered public API, but it is *unstable*
 // and outside of the normal semver guarantees:
 //
@@ -13,10 +7,15 @@ include!("no_atomic_cas.rs");
 //      need to enable it manually when building for custom targets or using
 //      non-cargo build systems that don't run the build script.
 //
-// With the exceptions mentioned above, the rustc-cfg strings below are
-// *not* public API. Please let us know by opening a GitHub issue if your build
-// environment requires some way to enable these cfgs other than by executing
-// our build script.
+// With the exceptions mentioned above, the rustc-cfg emitted by the build
+// script are *not* public API.
+
+#![warn(rust_2018_idioms, single_use_lifetimes)]
+
+use std::env;
+
+include!("no_atomic_cas.rs");
+
 fn main() {
     let target = match env::var("TARGET") {
         Ok(target) => target,
@@ -34,7 +33,7 @@ fn main() {
     // `cfg(target_has_atomic = "ptr")` as true when the build script doesn't
     // run. This is needed for compatibility with non-cargo build systems that
     // don't run the build script.
-    if NO_ATOMIC_CAS_TARGETS.contains(&&*target) {
+    if NO_ATOMIC_CAS.contains(&&*target) {
         println!("cargo:rustc-cfg=futures_no_atomic_cas");
     }
 

futures-core/build.rs

@@ -1,9 +1,3 @@
-#![warn(rust_2018_idioms, single_use_lifetimes)]
-
-use std::env;
-
-include!("no_atomic_cas.rs");
-
 // The rustc-cfg listed below are considered public API, but it is *unstable*
 // and outside of the normal semver guarantees:
 //
@@ -13,10 +7,15 @@ include!("no_atomic_cas.rs");
 //      need to enable it manually when building for custom targets or using
 //      non-cargo build systems that don't run the build script.
 //
-// With the exceptions mentioned above, the rustc-cfg strings below are
-// *not* public API. Please let us know by opening a GitHub issue if your build
-// environment requires some way to enable these cfgs other than by executing
-// our build script.
+// With the exceptions mentioned above, the rustc-cfg emitted by the build
+// script are *not* public API.
+
+#![warn(rust_2018_idioms, single_use_lifetimes)]
+
+use std::env;
+
+include!("no_atomic_cas.rs");
+
 fn main() {
     let target = match env::var("TARGET") {
         Ok(target) => target,
@@ -34,7 +33,7 @@ fn main() {
     // `cfg(target_has_atomic = "ptr")` as true when the build script doesn't
     // run. This is needed for compatibility with non-cargo build systems that
     // don't run the build script.
-    if NO_ATOMIC_CAS_TARGETS.contains(&&*target) {
+    if NO_ATOMIC_CAS.contains(&&*target) {
         println!("cargo:rustc-cfg=futures_no_atomic_cas");
     }
 

futures-task/build.rs

@@ -1,9 +1,3 @@
-#![warn(rust_2018_idioms, single_use_lifetimes)]
-
-use std::env;
-
-include!("no_atomic_cas.rs");
-
 // The rustc-cfg listed below are considered public API, but it is *unstable*
 // and outside of the normal semver guarantees:
 //
@@ -13,10 +7,15 @@ include!("no_atomic_cas.rs");
 //      need to enable it manually when building for custom targets or using
 //      non-cargo build systems that don't run the build script.
 //
-// With the exceptions mentioned above, the rustc-cfg strings below are
-// *not* public API. Please let us know by opening a GitHub issue if your build
-// environment requires some way to enable these cfgs other than by executing
-// our build script.
+// With the exceptions mentioned above, the rustc-cfg emitted by the build
+// script are *not* public API.
+
+#![warn(rust_2018_idioms, single_use_lifetimes)]
+
+use std::env;
+
+include!("no_atomic_cas.rs");
+
 fn main() {
     let target = match env::var("TARGET") {
         Ok(target) => target,
@@ -34,7 +33,7 @@ fn main() {
     // `cfg(target_has_atomic = "ptr")` as true when the build script doesn't
     // run. This is needed for compatibility with non-cargo build systems that
     // don't run the build script.
-    if NO_ATOMIC_CAS_TARGETS.contains(&&*target) {
+    if NO_ATOMIC_CAS.contains(&&*target) {
         println!("cargo:rustc-cfg=futures_no_atomic_cas");
     }
 

futures-util/build.rs

@@ -1,9 +1,3 @@
-#![warn(rust_2018_idioms, single_use_lifetimes)]
-
-use std::env;
-
-include!("no_atomic_cas.rs");
-
 // The rustc-cfg listed below are considered public API, but it is *unstable*
 // and outside of the normal semver guarantees:
 //
@@ -13,10 +7,15 @@ include!("no_atomic_cas.rs");
 //      need to enable it manually when building for custom targets or using
 //      non-cargo build systems that don't run the build script.
 //
-// With the exceptions mentioned above, the rustc-cfg strings below are
-// *not* public API. Please let us know by opening a GitHub issue if your build
-// environment requires some way to enable these cfgs other than by executing
-// our build script.
+// With the exceptions mentioned above, the rustc-cfg emitted by the build
+// script are *not* public API.
+
+#![warn(rust_2018_idioms, single_use_lifetimes)]
+
+use std::env;
+
+include!("no_atomic_cas.rs");
+
 fn main() {
     let target = match env::var("TARGET") {
         Ok(target) => target,
@@ -34,7 +33,7 @@ fn main() {
     // `cfg(target_has_atomic = "ptr")` as true when the build script doesn't
     // run. This is needed for compatibility with non-cargo build systems that
     // don't run the build script.
-    if NO_ATOMIC_CAS_TARGETS.contains(&&*target) {
+    if NO_ATOMIC_CAS.contains(&&*target) {
         println!("cargo:rustc-cfg=futures_no_atomic_cas");
     }
 

no_atomic_cas.rs

@@ -1,7 +1,7 @@
 // This file is @generated by no_atomic_cas.sh.
 // It is not intended for manual editing.
 
-const NO_ATOMIC_CAS_TARGETS: &[&str] = &[
+const NO_ATOMIC_CAS: &[&str] = &[
     "avr-unknown-gnu-atmega328",
     "bpfeb-unknown-none",
     "bpfel-unknown-none",