Revert "chore: disable warnings in old CI (#4691)"

This reverts commit b24df49a9d26057b44a869c6effce494ec10dd35 so we can
merge the CHANGELOG changes in #4691 into master.

.circleci/config.yml

@@ -1,25 +0,0 @@
-version: 2.1        
-jobs:
-  test-arm:
-    machine:
-      image: ubuntu-2004:202101-01
-    resource_class: arm.medium
-    environment:
-      # Change to pin rust versino
-      RUST_STABLE: stable
-    steps:
-      - checkout
-      - run:
-          name: Install Rust
-          command: |
-            curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs -o rustup.sh
-            chmod +x rustup.sh
-            ./rustup.sh -y --default-toolchain $RUST_STABLE
-            source "$HOME"/.cargo/env
-      # Only run Tokio tests
-      - run: cargo test --all-features -p tokio
-
-workflows:
-  ci:
-    jobs:
-      - test-arm

.cirrus.yml

@@ -1,5 +1,7 @@
 freebsd_instance:
   image: freebsd-12-2-release-amd64
+env:
+  RUSTFLAGS: -D warnings
 
 # Test FreeBSD in a full VM on cirrus-ci.com.  Test the i686 target too, in the
 # same VM.  The binary will be built in 32-bit mode, but will execute on a
@@ -23,7 +25,7 @@ task:
   name: FreeBSD docs
   env:
     RUSTFLAGS: --cfg docsrs
-    RUSTDOCFLAGS: --cfg docsrs
+    RUSTDOCFLAGS: --cfg docsrs -Dwarnings
   setup_script:
     - pkg install -y bash curl
     - curl https://sh.rustup.rs -sSf --output rustup.sh

.github/workflows/ci.yml

@@ -7,6 +7,7 @@ on:
 name: CI
 
 env:
+  RUSTFLAGS: -Dwarnings
   RUST_BACKTRACE: 1
   nightly: nightly-2021-10-25
   minrust: 1.45.2
@@ -64,6 +65,11 @@ jobs:
         run: cargo hack test --each-feature
         working-directory: tests-integration
 
+      # Run macro build tests
+      - name: test tests-build --each-feature
+        run: cargo hack test --each-feature
+        working-directory: tests-build
+
       # Build benchmarks. Run of benchmarks is done by bench.yml workflow.
       - name: build benches
         run: cargo build --benches
@@ -123,7 +129,7 @@ jobs:
         run: cargo test --all-features
         working-directory: tokio
         env:
-          RUSTFLAGS: --cfg tokio_unstable
+          RUSTFLAGS: --cfg tokio_unstable -Dwarnings
 
   miri:
     name: miri
@@ -207,7 +213,7 @@ jobs:
       - name: check --each-feature --unstable
         run: cargo hack check --all --each-feature -Z avoid-dev-deps
         env:
-          RUSTFLAGS: --cfg tokio_unstable
+          RUSTFLAGS: --cfg tokio_unstable -Dwarnings
 
   minrust:
     name: minrust
@@ -292,7 +298,7 @@ jobs:
         run: cargo doc --lib --no-deps --all-features --document-private-items
         env:
           RUSTFLAGS: --cfg docsrs
-          RUSTDOCFLAGS: --cfg docsrs
+          RUSTDOCFLAGS: --cfg docsrs -Dwarnings
 
   loom-compile:
     name: build loom tests
@@ -306,7 +312,7 @@ jobs:
         run: cargo test --no-run --lib --features full
         working-directory: tokio
         env:
-          RUSTFLAGS: --cfg loom --cfg tokio_unstable
+          RUSTFLAGS: --cfg loom --cfg tokio_unstable -Dwarnings
 
   check-readme:
     name: Check README

.github/workflows/loom.yml

@@ -8,6 +8,7 @@ on:
 name: Loom
 
 env:
+  RUSTFLAGS: -Dwarnings
   RUST_BACKTRACE: 1
 
 jobs:
@@ -34,6 +35,6 @@ jobs:
         run: cargo test --lib --release --features full -- --nocapture $SCOPE
         working-directory: tokio
         env:
-          RUSTFLAGS: --cfg loom --cfg tokio_unstable
+          RUSTFLAGS: --cfg loom --cfg tokio_unstable -Dwarnings
           LOOM_MAX_PREEMPTIONS: 2
           SCOPE: ${{ matrix.scope }}

Cargo.toml

@@ -11,5 +11,6 @@ members = [
   "benches",
   "examples",
   "stress-test",
+  "tests-build",
   "tests-integration",
 ]

tests-build/Cargo.toml

@@ -0,0 +1,16 @@
+[package]
+name = "tests-build"
+version = "0.1.0"
+authors = ["Tokio Contributors <team@tokio.rs>"]
+edition = "2018"
+publish = false
+
+[features]
+full = ["tokio/full"]
+rt = ["tokio/rt", "tokio/macros"]
+
+[dependencies]
+tokio = { path = "../tokio", optional = true }
+
+[dev-dependencies]
+trybuild = "1.0"

tests-build/README.md

@@ -0,0 +1,2 @@
+Tests the various combination of feature flags. This is broken out to a separate
+crate to work around limitations with cargo features.

tests-build/src/lib.rs

@@ -0,0 +1,2 @@
+#[cfg(feature = "tokio")]
+pub use tokio;

tests-build/tests/fail/macros_core_no_default.rs

@@ -0,0 +1,6 @@
+use tests_build::tokio;
+
+#[tokio::main]
+async fn my_fn() {}
+
+fn main() {}

tests-build/tests/fail/macros_core_no_default.stderr

@@ -0,0 +1,7 @@
+error: The default runtime flavor is `multi_thread`, but the `rt-multi-thread` feature is disabled.
+ --> $DIR/macros_core_no_default.rs:3:1
+  |
+3 | #[tokio::main]
+  | ^^^^^^^^^^^^^^
+  |
+  = note: this error originates in the attribute macro `tokio::main` (in Nightly builds, run with -Z macro-backtrace for more info)

tests-build/tests/fail/macros_dead_code.rs

@@ -0,0 +1,8 @@
+#![deny(dead_code)]
+
+use tests_build::tokio;
+
+#[tokio::main]
+async fn f() {}
+
+fn main() {}

tests-build/tests/fail/macros_dead_code.stderr

@@ -0,0 +1,11 @@
+error: function is never used: `f`
+ --> $DIR/macros_dead_code.rs:6:10
+  |
+6 | async fn f() {}
+  |          ^
+  |
+note: the lint level is defined here
+ --> $DIR/macros_dead_code.rs:1:9
+  |
+1 | #![deny(dead_code)]
+  |         ^^^^^^^^^

tests-build/tests/fail/macros_invalid_input.rs

@@ -0,0 +1,40 @@
+use tests_build::tokio;
+
+#[tokio::main]
+fn main_is_not_async() {}
+
+#[tokio::main(foo)]
+async fn main_attr_has_unknown_args() {}
+
+#[tokio::main(threadpool::bar)]
+async fn main_attr_has_path_args() {}
+
+#[tokio::test]
+fn test_is_not_async() {}
+
+#[tokio::test(foo)]
+async fn test_attr_has_args() {}
+
+#[tokio::test(foo = 123)]
+async fn test_unexpected_attr() {}
+
+#[tokio::test(flavor = 123)]
+async fn test_flavor_not_string() {}
+
+#[tokio::test(flavor = "foo")]
+async fn test_unknown_flavor() {}
+
+#[tokio::test(flavor = "multi_thread", start_paused = false)]
+async fn test_multi_thread_with_start_paused() {}
+
+#[tokio::test(flavor = "multi_thread", worker_threads = "foo")]
+async fn test_worker_threads_not_int() {}
+
+#[tokio::test(flavor = "current_thread", worker_threads = 4)]
+async fn test_worker_threads_and_current_thread() {}
+
+#[tokio::test]
+#[test]
+async fn test_has_second_test_attr() {}
+
+fn main() {}

tests-build/tests/fail/macros_invalid_input.stderr

@@ -0,0 +1,71 @@
+error: the `async` keyword is missing from the function declaration
+ --> $DIR/macros_invalid_input.rs:4:1
+  |
+4 | fn main_is_not_async() {}
+  | ^^
+
+error: Unknown attribute foo is specified; expected one of: `flavor`, `worker_threads`, `start_paused`
+ --> $DIR/macros_invalid_input.rs:6:15
+  |
+6 | #[tokio::main(foo)]
+  |               ^^^
+
+error: Must have specified ident
+ --> $DIR/macros_invalid_input.rs:9:15
+  |
+9 | #[tokio::main(threadpool::bar)]
+  |               ^^^^^^^^^^^^^^^
+
+error: the `async` keyword is missing from the function declaration
+  --> $DIR/macros_invalid_input.rs:13:1
+   |
+13 | fn test_is_not_async() {}
+   | ^^
+
+error: Unknown attribute foo is specified; expected one of: `flavor`, `worker_threads`, `start_paused`
+  --> $DIR/macros_invalid_input.rs:15:15
+   |
+15 | #[tokio::test(foo)]
+   |               ^^^
+
+error: Unknown attribute foo is specified; expected one of: `flavor`, `worker_threads`, `start_paused`
+  --> $DIR/macros_invalid_input.rs:18:15
+   |
+18 | #[tokio::test(foo = 123)]
+   |               ^^^^^^^^^
+
+error: Failed to parse value of `flavor` as string.
+  --> $DIR/macros_invalid_input.rs:21:24
+   |
+21 | #[tokio::test(flavor = 123)]
+   |                        ^^^
+
+error: No such runtime flavor `foo`. The runtime flavors are `current_thread` and `multi_thread`.
+  --> $DIR/macros_invalid_input.rs:24:24
+   |
+24 | #[tokio::test(flavor = "foo")]
+   |                        ^^^^^
+
+error: The `start_paused` option requires the `current_thread` runtime flavor. Use `#[tokio::test(flavor = "current_thread")]`
+  --> $DIR/macros_invalid_input.rs:27:55
+   |
+27 | #[tokio::test(flavor = "multi_thread", start_paused = false)]
+   |                                                       ^^^^^
+
+error: Failed to parse value of `worker_threads` as integer.
+  --> $DIR/macros_invalid_input.rs:30:57
+   |
+30 | #[tokio::test(flavor = "multi_thread", worker_threads = "foo")]
+   |                                                         ^^^^^
+
+error: The `worker_threads` option requires the `multi_thread` runtime flavor. Use `#[tokio::test(flavor = "multi_thread")]`
+  --> $DIR/macros_invalid_input.rs:33:59
+   |
+33 | #[tokio::test(flavor = "current_thread", worker_threads = 4)]
+   |                                                           ^
+
+error: second test attribute is supplied
+  --> $DIR/macros_invalid_input.rs:37:1
+   |
+37 | #[test]
+   | ^^^^^^^

tests-build/tests/fail/macros_type_mismatch.rs

@@ -0,0 +1,26 @@
+use tests_build::tokio;
+
+#[tokio::main]
+async fn missing_semicolon_or_return_type() {
+    Ok(())
+}
+
+#[tokio::main]
+async fn missing_return_type() {
+    return Ok(());
+}
+
+#[tokio::main]
+async fn extra_semicolon() -> Result<(), ()> {
+    /* TODO(taiki-e): help message still wrong
+    help: try using a variant of the expected enum
+       |
+    23 |     Ok(Ok(());)
+       |
+    23 |     Err(Ok(());)
+       |
+    */
+    Ok(());
+}
+
+fn main() {}

tests-build/tests/fail/macros_type_mismatch.stderr

@@ -0,0 +1,45 @@
+error[E0308]: mismatched types
+ --> $DIR/macros_type_mismatch.rs:5:5
+  |
+5 |     Ok(())
+  |     ^^^^^^ expected `()`, found enum `Result`
+  |
+  = note: expected unit type `()`
+                  found enum `Result<(), _>`
+help: consider using a semicolon here
+  |
+5 |     Ok(());
+  |           +
+help: try adding a return type
+  |
+4 | async fn missing_semicolon_or_return_type() -> Result<(), _> {
+  |                                             ++++++++++++++++
+
+error[E0308]: mismatched types
+  --> $DIR/macros_type_mismatch.rs:10:5
+   |
+9  | async fn missing_return_type() {
+   |                                - help: try adding a return type: `-> Result<(), _>`
+10 |     return Ok(());
+   |     ^^^^^^^^^^^^^^ expected `()`, found enum `Result`
+   |
+   = note: expected unit type `()`
+                   found enum `Result<(), _>`
+
+error[E0308]: mismatched types
+  --> $DIR/macros_type_mismatch.rs:23:5
+   |
+14 | async fn extra_semicolon() -> Result<(), ()> {
+   |                               -------------- expected `Result<(), ()>` because of return type
+...
+23 |     Ok(());
+   |     ^^^^^^^ expected enum `Result`, found `()`
+   |
+   = note:   expected enum `Result<(), ()>`
+           found unit type `()`
+help: try using a variant of the expected enum
+   |
+23 |     Ok(Ok(());)
+   |
+23 |     Err(Ok(());)
+   |

tests-build/tests/macros.rs

@@ -0,0 +1,27 @@
+#[test]
+fn compile_fail_full() {
+    let t = trybuild::TestCases::new();
+
+    #[cfg(feature = "full")]
+    t.pass("tests/pass/forward_args_and_output.rs");
+
+    #[cfg(feature = "full")]
+    t.pass("tests/pass/macros_main_return.rs");
+
+    #[cfg(feature = "full")]
+    t.pass("tests/pass/macros_main_loop.rs");
+
+    #[cfg(feature = "full")]
+    t.compile_fail("tests/fail/macros_invalid_input.rs");
+
+    #[cfg(feature = "full")]
+    t.compile_fail("tests/fail/macros_dead_code.rs");
+
+    #[cfg(feature = "full")]
+    t.compile_fail("tests/fail/macros_type_mismatch.rs");
+
+    #[cfg(all(feature = "rt", not(feature = "full")))]
+    t.compile_fail("tests/fail/macros_core_no_default.rs");
+
+    drop(t);
+}

tests-build/tests/macros_clippy.rs

@@ -0,0 +1,7 @@
+#[cfg(feature = "full")]
+#[tokio::test]
+async fn test_with_semicolon_without_return_type() {
+    #![deny(clippy::semicolon_if_nothing_returned)]
+
+    dbg!(0);
+}

tests-build/tests/pass/forward_args_and_output.rs

@@ -0,0 +1,13 @@
+use tests_build::tokio;
+
+fn main() {}
+
+// arguments and output type is forwarded so other macros can access them
+
+#[tokio::test]
+async fn test_fn_has_args(_x: u8) {}
+
+#[tokio::test]
+async fn test_has_output() -> Result<(), Box<dyn std::error::Error>> {
+    Ok(())
+}

tests-build/tests/pass/macros_main_loop.rs

@@ -0,0 +1,14 @@
+use tests_build::tokio;
+
+#[tokio::main]
+async fn main() -> Result<(), ()> {
+    loop {
+        if !never() {
+            return Ok(());
+        }
+    }
+}
+
+fn never() -> bool {
+    std::time::Instant::now() > std::time::Instant::now()
+}

tests-build/tests/pass/macros_main_return.rs

@@ -0,0 +1,6 @@
+use tests_build::tokio;
+
+#[tokio::main]
+async fn main() -> Result<(), ()> {
+    return Ok(());
+}

tokio/src/time/driver/sleep.rs

@@ -324,8 +324,8 @@ impl Sleep {
     }
 
     fn reset_inner(self: Pin<&mut Self>, deadline: Instant) {
-        let mut me = self.project();
-        me.entry.as_mut().reset(deadline);
+        let me = self.project();
+        me.entry.reset(deadline);
         (*me.inner).deadline = deadline;
 
         #[cfg(all(tokio_unstable, feature = "tracing"))]
@@ -349,12 +349,12 @@ impl Sleep {
 
     cfg_not_trace! {
         fn poll_elapsed(self: Pin<&mut Self>, cx: &mut task::Context<'_>) -> Poll<Result<(), Error>> {
-            let mut me = self.project();
+            let me = self.project();
 
             // Keep track of task budget
             let coop = ready!(crate::coop::poll_proceed(cx));
 
-            me.entry.as_mut().poll_elapsed(cx).map(move |r| {
+            me.entry.poll_elapsed(cx).map(move |r| {
                 coop.made_progress();
                 r
             })
@@ -363,7 +363,7 @@ impl Sleep {
 
     cfg_trace! {
         fn poll_elapsed(self: Pin<&mut Self>, cx: &mut task::Context<'_>) -> Poll<Result<(), Error>> {
-            let mut me = self.project();
+            let me = self.project();
             // Keep track of task budget
             let coop = ready!(trace_poll_op!(
                 "poll_elapsed",
@@ -371,7 +371,7 @@ impl Sleep {
                 me.inner.resource_span.id(),
             ));
 
-            let result =  me.entry.as_mut().poll_elapsed(cx).map(move |r| {
+            let result =  me.entry.poll_elapsed(cx).map(move |r| {
                 coop.made_progress();
                 r
             });