Merge #428

428: Fix breakage with nightly feature r=jeehoonkang a=taiki-e

`target_has_atomic = "cas"` was removed in rust-lang/rust#65214.

Fixes rust-lang/rust#65424 
Fixes #412


Co-authored-by: Taiki Endo <te316e89@gmail.com>

.travis.yml

@@ -16,24 +16,31 @@ matrix:
   - rust: 1.28.0
     name: "crossbeam on 1.28.0"
     script: ./ci/crossbeam.sh
+    before_script: ./ci/downgrade-dependencies.sh
   - rust: 1.26.0
     name: "crossbeam-channel on 1.26.0"
     script: ./ci/crossbeam-channel.sh
+    before_script: ./ci/downgrade-dependencies.sh
   - rust: 1.28.0
     name: "crossbeam-deque on 1.28.0"
     script: ./ci/crossbeam-deque.sh
+    before_script: ./ci/downgrade-dependencies.sh
   - rust: 1.26.0
     name: "crossbeam-epoch on 1.26.0"
     script: ./ci/crossbeam-epoch.sh
+    before_script: ./ci/downgrade-dependencies.sh
   - rust: 1.26.0
     name: "crossbeam-queue on 1.26.0"
     script: ./ci/crossbeam-queue.sh
+    before_script: ./ci/downgrade-dependencies.sh
   - rust: 1.28.0
     name: "crossbeam-skiplist on 1.28.0"
     script: ./ci/crossbeam-skiplist.sh
+    before_script: ./ci/downgrade-dependencies.sh
   - rust: 1.26.0
     name: "crossbeam-utils on 1.26.0"
     script: ./ci/crossbeam-utils.sh
+    before_script: ./ci/downgrade-dependencies.sh
 
   # Test crates on nightly Rust.
   - rust: nightly

ci/downgrade-dependencies.sh

@@ -0,0 +1,5 @@
+# lazy_static 1.4 requires Rust 1.27+
+# and cfg-if 1.10 requires Rust 1.31+ so downgrade it.
+- cargo generate-lockfile
+- cargo update -p cfg-if --precise 1.9
+- cargo update -p lazy_static --precise 1.3

crossbeam-epoch/src/lib.rs

@@ -73,10 +73,7 @@ cfg_if! {
     }
 }
 
-#[cfg_attr(
-    feature = "nightly",
-    cfg(all(target_has_atomic = "cas", target_has_atomic = "ptr"))
-)]
+#[cfg_attr(feature = "nightly", cfg(target_has_atomic = "ptr"))]
 cfg_if! {
     if #[cfg(any(feature = "alloc", feature = "std"))] {
         extern crate crossbeam_utils;

crossbeam-skiplist/src/lib.rs

@@ -18,10 +18,7 @@ cfg_if! {
     }
 }
 
-#[cfg_attr(
-    feature = "nightly",
-    cfg(all(target_has_atomic = "cas", target_has_atomic = "ptr"))
-)]
+#[cfg_attr(feature = "nightly", cfg(target_has_atomic = "ptr"))]
 cfg_if! {
     if #[cfg(any(feature = "alloc", feature = "std"))] {
         extern crate crossbeam_epoch as epoch;

crossbeam-utils/src/lib.rs

@@ -44,10 +44,7 @@ cfg_if! {
     }
 }
 
-#[cfg_attr(
-    feature = "nightly",
-    cfg(all(target_has_atomic = "cas", target_has_atomic = "ptr"))
-)]
+#[cfg_attr(feature = "nightly", cfg(target_has_atomic = "ptr"))]
 pub mod atomic;
 
 mod cache_padded;

src/lib.rs

@@ -68,10 +68,7 @@ pub use _epoch::crossbeam_epoch as epoch;
 
 extern crate crossbeam_utils;
 
-#[cfg_attr(
-    feature = "nightly",
-    cfg(all(target_has_atomic = "cas", target_has_atomic = "ptr"))
-)]
+#[cfg_attr(feature = "nightly", cfg(target_has_atomic = "ptr"))]
 pub use crossbeam_utils::atomic;
 
 /// Miscellaneous utilities.