util: Rewrite Arc based on std::sync::Arc

.github/.cspell/project-dictionary.txt

@@ -44,6 +44,7 @@ DESTDIR
 DEVEL
 dlsym
 DWCAS
+elems
 espup
 exynos
 FIQs
@@ -157,6 +158,7 @@ uapi
 uart
 umax
 umin
+unclonable
 unistd
 unparse
 usart

.github/workflows/ci.yml

@@ -271,12 +271,12 @@ jobs:
         if: (matrix.target == '' && !contains(matrix.rust, 'i686') || startsWith(matrix.target, 'x86_64')) || startsWith(matrix.target, 'aarch64') && !(contains(matrix.target, '-musl') && matrix.flags == '') || startsWith(matrix.target, 'armv5te') || matrix.target == 'arm-linux-androideabi'
       # outline-atomics is disabled by default on aarch64 musl with static linking and powerpc64
       # powerpc64le- (little-endian) is skipped because it is pwr8 by default
-      - run: tools/test.sh -vv --tests $TARGET $BUILD_STD $RELEASE
+      - run: tools/test.sh -vv --tests $TARGET $BUILD_STD $RELEASE --exclude api-test
         env:
           RUSTDOCFLAGS: ${{ env.RUSTDOCFLAGS }} --cfg portable_atomic_outline_atomics
           RUSTFLAGS: ${{ env.RUSTFLAGS }} --cfg portable_atomic_outline_atomics
         if: startsWith(matrix.target, 'aarch64') && contains(matrix.target, '-musl') && matrix.flags == '' || startsWith(matrix.target, 'powerpc64-')
-      - run: tools/test.sh -vv --tests $TARGET $BUILD_STD $RELEASE
+      - run: tools/test.sh -vv --tests $TARGET $BUILD_STD $RELEASE --exclude api-test
         env:
           # Note: detect_false cfg is intended to make it easy for portable-atomic developers to
           # test cases such as has_cmpxchg16b == false, has_lse == false,
@@ -398,6 +398,7 @@ jobs:
       matrix:
         include:
           - rust: '1.34'
+          - rust: '1.36'
           - rust: '1.59'
           - rust: stable
           - rust: beta
@@ -519,6 +520,7 @@ jobs:
           persist-credentials: false
       - name: Install Rust
         run: rustup toolchain add nightly --no-self-update --component miri && rustup default nightly
+      - uses: taiki-e/install-action@cargo-hack
       # - run: sudo apt-get -o Acquire::Retries=10 -qq update && sudo apt-get -o Acquire::Retries=10 -o Dpkg::Use-Pty=0 install -y --no-install-recommends moreutils
       - run: echo "TARGET=--target=${{ matrix.target }}" >>"${GITHUB_ENV}"
         if: matrix.target != 'x86_64-unknown-linux-gnu'
@@ -544,6 +546,7 @@ jobs:
           persist-credentials: false
       - name: Install Rust
         run: rustup toolchain add nightly --no-self-update && rustup default nightly
+      - uses: taiki-e/install-action@cargo-hack
       # - run: sudo apt-get -o Acquire::Retries=10 -qq update && sudo apt-get -o Acquire::Retries=10 -o Dpkg::Use-Pty=0 install -y --no-install-recommends moreutils
       - run: |
           echo "ASAN_OPTIONS=detect_stack_use_after_return=1" >>"${GITHUB_ENV}"
@@ -578,6 +581,7 @@ jobs:
           persist-credentials: false
       - name: Install Rust
         run: rustup toolchain add nightly --no-self-update && rustup default nightly
+      - uses: taiki-e/install-action@cargo-hack
       # - run: sudo apt-get -o Acquire::Retries=10 -qq update && sudo apt-get -o Acquire::Retries=10 -o Dpkg::Use-Pty=0 install -y --no-install-recommends moreutils
       - uses: taiki-e/install-action@valgrind
       - run: tools/test.sh valgrind -vv

portable-atomic-util/build.rs

@@ -33,10 +33,22 @@ fn main() {
     if !version.probe(36, 2019, 4, 14) {
         println!("cargo:rustc-cfg=portable_atomic_no_alloc");
     }
+    // Layout::{align_to,pad_to_align,extend,array} stabilized in Rust 1.44 (nightly-2020-04-22) https://github.com/rust-lang/rust/pull/69362
+    if !version.probe(44, 2020, 4, 21) {
+        println!("cargo:rustc-cfg=portable_atomic_no_alloc_layout_extras");
+    }
+    // min_const_generics stabilized in Rust 1.51 (nightly-2020-12-28): https://github.com/rust-lang/rust/pull/79135
+    if !version.probe(51, 2020, 12, 27) {
+        println!("cargo:rustc-cfg=portable_atomic_no_min_const_generics");
+    }
     // unsafe_op_in_unsafe_fn stabilized in Rust 1.52 (nightly-2021-03-11): https://github.com/rust-lang/rust/pull/79208
     if !version.probe(52, 2021, 3, 10) {
         println!("cargo:rustc-cfg=portable_atomic_no_unsafe_op_in_unsafe_fn");
     }
+    // https://github.com/rust-lang/rust/pull/84662 merged in Rust 1.56 (nightly-2021-08-02).
+    if !version.probe(56, 2021, 8, 1) {
+        println!("cargo:rustc-cfg=portable_atomic_no_core_unwind_safe");
+    }
 
     if version.nightly {
         // `cfg(sanitize = "..")` is not stabilized.