Maintain some nightly features and CI (#3934)

* remove `doc_auto_cfg`

removed in favor of `doc_cfg` which is already present

* fix optimization flags

the fix targets the change to panic_abort in rust-lang/rust#146974
Incidentally, this led me to realize that some RUSTFLAGS were being
ignored, due to the exclusivity of env variables vs config options (see ref).
With this change, all config options are read from toml files instead of
env variables.

reference: https://doc.rust-lang.org/cargo/reference/config.html#buildrustflags

use old optimization flags for master branch before this change

* skip example paths that don't contain a Cargo.toml

.cargo/config.toml

@@ -6,7 +6,3 @@ runner = 'wasmtime -W unknown-imports-trap=y'
 
 [target.wasm32-unknown-unknown]
 rustflags = ['--cfg', 'getrandom_backend="wasm_js"']
-
-# This section needs to be last.
-# GitHub Actions modifies this section.
-[unstable]

.github/workflows/size-cmp.yml

@@ -32,10 +32,15 @@ jobs:
 
       - name: Write Optimisation Flags
         run: |
-          echo 'build-std = ["std", "panic_abort"]' >> .cargo/config.toml
-          echo 'build-std-features = ["panic_immediate_abort"]' >> .cargo/config.toml
-          echo '[build]' >> .cargo/config.toml
-          echo 'rustflags = ["-Cpanic=abort"]' >> .cargo/config.toml
+          if [ -x ci/write-min-size-flags.sh ] ; then
+            ci/write-min-size-flags.sh
+          else
+            # this branch is a fallback used only for compatibility with earlier commits
+            # in the repository and other branches and can be removed in the future.
+            echo 'build-std = ["std", "panic_abort"]' >> .cargo/config.toml
+            echo '[build]' >> .cargo/config.toml
+            echo 'rustflags = ["-Cpanic=abort"]' >> .cargo/config.toml
+          fi
 
       - name: Setup toolchain
         uses: dtolnay/rust-toolchain@master

Cargo.toml

@@ -4,6 +4,7 @@ members = [
     "tools/*",
     "examples/*",
 ]
+exclude = ["examples/.cargo"]
 default-members = [
     "packages/*",
 ]

ci/write-min-size-flags.sh

@@ -0,0 +1,2 @@
+#!/usr/bin/env bash
+cat examples/.cargo/min-size-config.toml >> examples/.cargo/dummy-min-size-config.toml

examples/.cargo/config.toml

@@ -0,0 +1,7 @@
+# this include is a bit of a hack: due to the unstable nature of the feature,
+# this file only gets included on nightly, hence it can specify "nightly only"
+# rustflags and options
+include = ["unstable.toml", "dummy-min-size-config.toml"]
+
+[unstable]
+config-include = true

examples/.cargo/dummy-min-size-config.toml

@@ -0,0 +1,2 @@
+# This file is intentionally left empty.
+# It gets filled by `min-size-config.toml` in some cases by CI

examples/.cargo/min-size-config.toml

@@ -0,0 +1,6 @@
+[unstable]
+build-std = ["core", "std", "panic_abort"]
+build-std-features = ["optimize_for_size"]
+
+[target.'cfg(target_arch = "wasm32")']
+rustflags = ["-Zunstable-options", "-Cpanic=immediate-abort", "--cfg", "nightly_yew"]

examples/.cargo/unstable.toml

@@ -0,0 +1,2 @@
+[target.wasm32-unknown-unknown]
+rustflags = ["--cfg", "nightly_yew"]

packages/yew/src/lib.rs

@@ -1,7 +1,6 @@
 #![allow(clippy::needless_doctest_main)]
 #![doc(html_logo_url = "https://yew.rs/img/logo.png")]
 #![cfg_attr(documenting, feature(doc_cfg))]
-#![cfg_attr(documenting, feature(doc_auto_cfg))]
 #![cfg_attr(nightly_yew, feature(fn_traits, unboxed_closures))]
 
 //! # Yew Framework - API Documentation

tools/build-examples/src/main.rs

@@ -33,7 +33,7 @@ fn main() -> ExitCode {
         let path = entry.path();
 
         // Skip if not a directory
-        if !path.is_dir() {
+        if should_skip_path(&path) {
             continue;
         }
 
@@ -81,27 +81,19 @@ fn main() -> ExitCode {
     }
 }
 
+fn should_skip_path(path: &Path) -> bool {
+    !path.is_dir() || !path.join("Cargo.toml").exists()
+}
+
 fn build_example(path: &Path, output_dir: &Path, example: &str) -> bool {
     let public_url_prefix = env::var("PUBLIC_URL_PREFIX").unwrap_or_default();
 
     let dist_dir = output_dir.join(example);
 
-    let uses_rand = has_rand_dependency(path);
-
-    let rustflags = format!(
-        "--cfg nightly_yew{}",
-        if uses_rand {
-            " --cfg getrandom_backend=\"wasm_js\""
-        } else {
-            ""
-        }
-    );
-
     // Run trunk build command
     let status = Command::new("trunk")
         .current_dir(path)
         .arg("build")
-        .env("RUSTFLAGS", rustflags)
         .arg("--release")
         .arg("--dist")
         .arg(&dist_dir)
@@ -137,17 +129,3 @@ fn build_example(path: &Path, output_dir: &Path, example: &str) -> bool {
         _ => false,
     }
 }
-
-// Function to check if the crate has a rand dependency
-fn has_rand_dependency(path: &Path) -> bool {
-    let cargo_toml_path = path.join("Cargo.toml");
-
-    if !cargo_toml_path.exists() {
-        return false;
-    }
-
-    match fs::read_to_string(&cargo_toml_path) {
-        Ok(content) => content.contains("rand = ") || content.contains("rand =\n"),
-        Err(_) => false,
-    }
-}