Update invalid atomic ordering lint

The restriction that success ordering must be at least as strong as its failure ordering in compare-exchange operations was lifted in #98383.
rust-lang · Dylan-DPC · Jun 12, 2022 · Jun 13, 2022 · Jul 18, 2022 · Jul 18, 2022
commit 45afc214af3ad47be4252b82832a78e6280f3708
diff --git a/compiler/rustc_error_messages/locales/en-US/lint.ftl b/compiler/rustc_error_messages/locales/en-US/lint.ftl
@@ -247,11 +247,6 @@ lint-atomic-ordering-invalid = `{$method}`'s failure ordering may not be `Releas
     .label = invalid failure ordering
     .help = consider using `Acquire` or `Relaxed` failure ordering instead
 
-lint-atomic-ordering-invalid-fail-success = `{$method}`'s success ordering must be at least as strong as its failure ordering
-    .fail-label = `{$fail_ordering}` failure ordering
-    .success-label = `{$success_ordering}` success ordering
-    .suggestion = consider using `{$success_suggestion}` success ordering instead
-
 lint-unused-op = unused {$op} that must be used
     .label = the {$op} produces a value
     .suggestion = use `let _ = ...` to ignore the resulting value

diff --git a/compiler/rustc_lint/src/types.rs b/compiler/rustc_lint/src/types.rs
@@ -1434,10 +1434,6 @@ declare_lint! {
     /// - Passing `Ordering::Release` or `Ordering::AcqRel` as the failure
     ///   ordering for any of `AtomicType::compare_exchange`,
     ///   `AtomicType::compare_exchange_weak`, or `AtomicType::fetch_update`.
-    ///
-    /// - Passing in a pair of orderings to `AtomicType::compare_exchange`,
-    ///   `AtomicType::compare_exchange_weak`, or `AtomicType::fetch_update`
-    ///   where the failure ordering is stronger than the success ordering.
     INVALID_ATOMIC_ORDERING,
     Deny,
     "usage of invalid atomic ordering in atomic operations and memory fences"
@@ -1544,9 +1540,9 @@ impl InvalidAtomicOrdering {
         let Some((method, args)) = Self::inherent_atomic_method_call(cx, expr, &[sym::fetch_update, sym::compare_exchange, sym::compare_exchange_weak])
             else {return };
 
-        let (success_order_arg, fail_order_arg) = match method {
-            sym::fetch_update => (&args[1], &args[2]),
-            sym::compare_exchange | sym::compare_exchange_weak => (&args[3], &args[4]),
+        let fail_order_arg = match method {
+            sym::fetch_update => &args[2],
+            sym::compare_exchange | sym::compare_exchange_weak => &args[4],
             _ => return,
         };
 
@@ -1568,37 +1564,6 @@ impl InvalidAtomicOrdering {
                 InvalidAtomicOrderingDiag { method, fail_order_arg_span: fail_order_arg.span },
             );
         }
-
-        let Some(success_ordering) = Self::match_ordering(cx, success_order_arg) else { return };
-
-        if matches!(
-            (success_ordering, fail_ordering),
-            (sym::Relaxed | sym::Release, sym::Acquire)
-                | (sym::Relaxed | sym::Release | sym::Acquire | sym::AcqRel, sym::SeqCst)
-        ) {
-            let success_suggestion =
-                if success_ordering == sym::Release && fail_ordering == sym::Acquire {
-                    sym::AcqRel
-                } else {
-                    fail_ordering
-                };
-            cx.struct_span_lint(INVALID_ATOMIC_ORDERING, success_order_arg.span, |diag| {
-                diag.build(fluent::lint::atomic_ordering_invalid_fail_success)
-                    .set_arg("method", method)
-                    .set_arg("fail_ordering", fail_ordering)
-                    .set_arg("success_ordering", success_ordering)
-                    .set_arg("success_suggestion", success_suggestion)
-                    .span_label(fail_order_arg.span, fluent::lint::fail_label)
-                    .span_label(success_order_arg.span, fluent::lint::success_label)
-                    .span_suggestion_short(
-                        success_order_arg.span,
-                        fluent::lint::suggestion,
-                        format!("std::sync::atomic::Ordering::{success_suggestion}"),
-                        Applicability::MaybeIncorrect,
-                    )
-                    .emit();
-            });
-        }
     }
 }
 

diff --git a/src/test/ui/lint/lint-invalid-atomic-ordering-exchange-weak.rs b/src/test/ui/lint/lint-invalid-atomic-ordering-exchange-weak.rs
@@ -9,11 +9,17 @@ fn main() {
 
     // Allowed ordering combos
     let _ = x.compare_exchange_weak(ptr, ptr2, Ordering::Relaxed, Ordering::Relaxed);
-    let _ = x.compare_exchange_weak(ptr, ptr2, Ordering::Acquire, Ordering::Acquire);
+    let _ = x.compare_exchange_weak(ptr, ptr2, Ordering::Relaxed, Ordering::Acquire);
+    let _ = x.compare_exchange_weak(ptr, ptr2, Ordering::Relaxed, Ordering::SeqCst);
     let _ = x.compare_exchange_weak(ptr, ptr2, Ordering::Acquire, Ordering::Relaxed);
+    let _ = x.compare_exchange_weak(ptr, ptr2, Ordering::Acquire, Ordering::Acquire);
+    let _ = x.compare_exchange_weak(ptr2, ptr, Ordering::Acquire, Ordering::SeqCst);
     let _ = x.compare_exchange_weak(ptr, ptr2, Ordering::Release, Ordering::Relaxed);
-    let _ = x.compare_exchange_weak(ptr, ptr2, Ordering::AcqRel, Ordering::Acquire);
+    let _ = x.compare_exchange_weak(ptr2, ptr, Ordering::Release, Ordering::Acquire);
+    let _ = x.compare_exchange_weak(ptr2, ptr, Ordering::Release, Ordering::SeqCst);
     let _ = x.compare_exchange_weak(ptr, ptr2, Ordering::AcqRel, Ordering::Relaxed);
+    let _ = x.compare_exchange_weak(ptr, ptr2, Ordering::AcqRel, Ordering::Acquire);
+    let _ = x.compare_exchange_weak(ptr2, ptr, Ordering::AcqRel, Ordering::SeqCst);
     let _ = x.compare_exchange_weak(ptr, ptr2, Ordering::SeqCst, Ordering::Relaxed);
     let _ = x.compare_exchange_weak(ptr, ptr2, Ordering::SeqCst, Ordering::Acquire);
     let _ = x.compare_exchange_weak(ptr, ptr2, Ordering::SeqCst, Ordering::SeqCst);
@@ -41,22 +47,4 @@ fn main() {
     //~^ ERROR `compare_exchange_weak`'s failure ordering may not be `Release` or `AcqRel`
     let _ = x.compare_exchange_weak(ptr, ptr2, Ordering::SeqCst, Ordering::Release);
     //~^ ERROR `compare_exchange_weak`'s failure ordering may not be `Release` or `AcqRel`
-
-    // Release success order forbids failure order of Acquire or SeqCst
-    let _ = x.compare_exchange_weak(ptr2, ptr, Ordering::Release, Ordering::Acquire);
-    //~^ ERROR `compare_exchange_weak`'s success ordering must be at least as strong as
-    let _ = x.compare_exchange_weak(ptr2, ptr, Ordering::Release, Ordering::SeqCst);
-    //~^ ERROR `compare_exchange_weak`'s success ordering must be at least as strong as
-
-    // Relaxed success order also forbids failure order of Acquire or SeqCst
-    let _ = x.compare_exchange_weak(ptr, ptr2, Ordering::Relaxed, Ordering::SeqCst);
-    //~^ ERROR `compare_exchange_weak`'s success ordering must be at least as strong as
-    let _ = x.compare_exchange_weak(ptr, ptr2, Ordering::Relaxed, Ordering::Acquire);
-    //~^ ERROR `compare_exchange_weak`'s success ordering must be at least as strong as
-
-    // Acquire/AcqRel forbids failure order of SeqCst
-    let _ = x.compare_exchange_weak(ptr2, ptr, Ordering::Acquire, Ordering::SeqCst);
-    //~^ ERROR `compare_exchange_weak`'s success ordering must be at least as strong as
-    let _ = x.compare_exchange_weak(ptr2, ptr, Ordering::AcqRel, Ordering::SeqCst);
-    //~^ ERROR `compare_exchange_weak`'s success ordering must be at least as strong as
 }
diff --git a/src/test/ui/lint/lint-invalid-atomic-ordering-exchange-weak.stderr b/src/test/ui/lint/lint-invalid-atomic-ordering-exchange-weak.stderr
@@ -1,5 +1,5 @@
 error: `compare_exchange_weak`'s failure ordering may not be `Release` or `AcqRel`, since a failed `compare_exchange_weak` does not result in a write
-  --> $DIR/lint-invalid-atomic-ordering-exchange-weak.rs:22:67
+  --> $DIR/lint-invalid-atomic-ordering-exchange-weak.rs:28:67
    |
 LL |     let _ = x.compare_exchange_weak(ptr2, ptr, Ordering::Relaxed, Ordering::AcqRel);
    |                                                                   ^^^^^^^^^^^^^^^^ invalid failure ordering
@@ -8,130 +8,76 @@ LL |     let _ = x.compare_exchange_weak(ptr2, ptr, Ordering::Relaxed, Ordering:
    = help: consider using `Acquire` or `Relaxed` failure ordering instead
 
 error: `compare_exchange_weak`'s failure ordering may not be `Release` or `AcqRel`, since a failed `compare_exchange_weak` does not result in a write
-  --> $DIR/lint-invalid-atomic-ordering-exchange-weak.rs:24:67
+  --> $DIR/lint-invalid-atomic-ordering-exchange-weak.rs:30:67
    |
 LL |     let _ = x.compare_exchange_weak(ptr2, ptr, Ordering::Acquire, Ordering::AcqRel);
    |                                                                   ^^^^^^^^^^^^^^^^ invalid failure ordering
    |
    = help: consider using `Acquire` or `Relaxed` failure ordering instead
 
 error: `compare_exchange_weak`'s failure ordering may not be `Release` or `AcqRel`, since a failed `compare_exchange_weak` does not result in a write
-  --> $DIR/lint-invalid-atomic-ordering-exchange-weak.rs:26:67
+  --> $DIR/lint-invalid-atomic-ordering-exchange-weak.rs:32:67
    |
 LL |     let _ = x.compare_exchange_weak(ptr2, ptr, Ordering::Release, Ordering::AcqRel);
    |                                                                   ^^^^^^^^^^^^^^^^ invalid failure ordering
    |
    = help: consider using `Acquire` or `Relaxed` failure ordering instead
 
 error: `compare_exchange_weak`'s failure ordering may not be `Release` or `AcqRel`, since a failed `compare_exchange_weak` does not result in a write
-  --> $DIR/lint-invalid-atomic-ordering-exchange-weak.rs:28:66
+  --> $DIR/lint-invalid-atomic-ordering-exchange-weak.rs:34:66
    |
 LL |     let _ = x.compare_exchange_weak(ptr2, ptr, Ordering::AcqRel, Ordering::AcqRel);
    |                                                                  ^^^^^^^^^^^^^^^^ invalid failure ordering
    |
    = help: consider using `Acquire` or `Relaxed` failure ordering instead
 
 error: `compare_exchange_weak`'s failure ordering may not be `Release` or `AcqRel`, since a failed `compare_exchange_weak` does not result in a write
-  --> $DIR/lint-invalid-atomic-ordering-exchange-weak.rs:30:66
+  --> $DIR/lint-invalid-atomic-ordering-exchange-weak.rs:36:66
    |
 LL |     let _ = x.compare_exchange_weak(ptr2, ptr, Ordering::SeqCst, Ordering::AcqRel);
    |                                                                  ^^^^^^^^^^^^^^^^ invalid failure ordering
    |
    = help: consider using `Acquire` or `Relaxed` failure ordering instead
 
 error: `compare_exchange_weak`'s failure ordering may not be `Release` or `AcqRel`, since a failed `compare_exchange_weak` does not result in a write
-  --> $DIR/lint-invalid-atomic-ordering-exchange-weak.rs:34:67
+  --> $DIR/lint-invalid-atomic-ordering-exchange-weak.rs:40:67
    |
 LL |     let _ = x.compare_exchange_weak(ptr, ptr2, Ordering::Relaxed, Ordering::Release);
    |                                                                   ^^^^^^^^^^^^^^^^^ invalid failure ordering
    |
    = help: consider using `Acquire` or `Relaxed` failure ordering instead
 
 error: `compare_exchange_weak`'s failure ordering may not be `Release` or `AcqRel`, since a failed `compare_exchange_weak` does not result in a write
-  --> $DIR/lint-invalid-atomic-ordering-exchange-weak.rs:36:67
+  --> $DIR/lint-invalid-atomic-ordering-exchange-weak.rs:42:67
    |
 LL |     let _ = x.compare_exchange_weak(ptr, ptr2, Ordering::Acquire, Ordering::Release);
    |                                                                   ^^^^^^^^^^^^^^^^^ invalid failure ordering
    |
    = help: consider using `Acquire` or `Relaxed` failure ordering instead
 
 error: `compare_exchange_weak`'s failure ordering may not be `Release` or `AcqRel`, since a failed `compare_exchange_weak` does not result in a write
-  --> $DIR/lint-invalid-atomic-ordering-exchange-weak.rs:38:67
+  --> $DIR/lint-invalid-atomic-ordering-exchange-weak.rs:44:67
    |
 LL |     let _ = x.compare_exchange_weak(ptr, ptr2, Ordering::Release, Ordering::Release);
    |                                                                   ^^^^^^^^^^^^^^^^^ invalid failure ordering
    |
    = help: consider using `Acquire` or `Relaxed` failure ordering instead
 
 error: `compare_exchange_weak`'s failure ordering may not be `Release` or `AcqRel`, since a failed `compare_exchange_weak` does not result in a write
-  --> $DIR/lint-invalid-atomic-ordering-exchange-weak.rs:40:66
+  --> $DIR/lint-invalid-atomic-ordering-exchange-weak.rs:46:66
    |
 LL |     let _ = x.compare_exchange_weak(ptr, ptr2, Ordering::AcqRel, Ordering::Release);
    |                                                                  ^^^^^^^^^^^^^^^^^ invalid failure ordering
    |
    = help: consider using `Acquire` or `Relaxed` failure ordering instead
 
 error: `compare_exchange_weak`'s failure ordering may not be `Release` or `AcqRel`, since a failed `compare_exchange_weak` does not result in a write
-  --> $DIR/lint-invalid-atomic-ordering-exchange-weak.rs:42:66
+  --> $DIR/lint-invalid-atomic-ordering-exchange-weak.rs:48:66
    |
 LL |     let _ = x.compare_exchange_weak(ptr, ptr2, Ordering::SeqCst, Ordering::Release);
    |                                                                  ^^^^^^^^^^^^^^^^^ invalid failure ordering
    |
    = help: consider using `Acquire` or `Relaxed` failure ordering instead
 
-error: `compare_exchange_weak`'s success ordering must be at least as strong as its failure ordering
-  --> $DIR/lint-invalid-atomic-ordering-exchange-weak.rs:46:48
-   |
-LL |     let _ = x.compare_exchange_weak(ptr2, ptr, Ordering::Release, Ordering::Acquire);
-   |                                                ^^^^^^^^^^^^^^^^^  ----------------- `Acquire` failure ordering
-   |                                                |
-   |                                                `Release` success ordering
-   |                                                help: consider using `AcqRel` success ordering instead
-
-error: `compare_exchange_weak`'s success ordering must be at least as strong as its failure ordering
-  --> $DIR/lint-invalid-atomic-ordering-exchange-weak.rs:48:48
-   |
-LL |     let _ = x.compare_exchange_weak(ptr2, ptr, Ordering::Release, Ordering::SeqCst);
-   |                                                ^^^^^^^^^^^^^^^^^  ---------------- `SeqCst` failure ordering
-   |                                                |
-   |                                                `Release` success ordering
-   |                                                help: consider using `SeqCst` success ordering instead
-
-error: `compare_exchange_weak`'s success ordering must be at least as strong as its failure ordering
-  --> $DIR/lint-invalid-atomic-ordering-exchange-weak.rs:52:48
-   |
-LL |     let _ = x.compare_exchange_weak(ptr, ptr2, Ordering::Relaxed, Ordering::SeqCst);
-   |                                                ^^^^^^^^^^^^^^^^^  ---------------- `SeqCst` failure ordering
-   |                                                |
-   |                                                `Relaxed` success ordering
-   |                                                help: consider using `SeqCst` success ordering instead
-
-error: `compare_exchange_weak`'s success ordering must be at least as strong as its failure ordering
-  --> $DIR/lint-invalid-atomic-ordering-exchange-weak.rs:54:48
-   |
-LL |     let _ = x.compare_exchange_weak(ptr, ptr2, Ordering::Relaxed, Ordering::Acquire);
-   |                                                ^^^^^^^^^^^^^^^^^  ----------------- `Acquire` failure ordering
-   |                                                |
-   |                                                `Relaxed` success ordering
-   |                                                help: consider using `Acquire` success ordering instead
-
-error: `compare_exchange_weak`'s success ordering must be at least as strong as its failure ordering
-  --> $DIR/lint-invalid-atomic-ordering-exchange-weak.rs:58:48
-   |
-LL |     let _ = x.compare_exchange_weak(ptr2, ptr, Ordering::Acquire, Ordering::SeqCst);
-   |                                                ^^^^^^^^^^^^^^^^^  ---------------- `SeqCst` failure ordering
-   |                                                |
-   |                                                `Acquire` success ordering
-   |                                                help: consider using `SeqCst` success ordering instead
-
-error: `compare_exchange_weak`'s success ordering must be at least as strong as its failure ordering
-  --> $DIR/lint-invalid-atomic-ordering-exchange-weak.rs:60:48
-   |
-LL |     let _ = x.compare_exchange_weak(ptr2, ptr, Ordering::AcqRel, Ordering::SeqCst);
-   |                                                ^^^^^^^^^^^^^^^^  ---------------- `SeqCst` failure ordering
-   |                                                |
-   |                                                `AcqRel` success ordering
-   |                                                help: consider using `SeqCst` success ordering instead
-
-error: aborting due to 16 previous errors
+error: aborting due to 10 previous errors
 
diff --git a/src/test/ui/lint/lint-invalid-atomic-ordering-exchange.rs b/src/test/ui/lint/lint-invalid-atomic-ordering-exchange.rs
@@ -7,11 +7,17 @@ fn main() {
 
     // Allowed ordering combos
     let _ = x.compare_exchange(0, 0, Ordering::Relaxed, Ordering::Relaxed);
-    let _ = x.compare_exchange(0, 0, Ordering::Acquire, Ordering::Acquire);
+    let _ = x.compare_exchange(0, 0, Ordering::Relaxed, Ordering::Acquire);
+    let _ = x.compare_exchange(0, 0, Ordering::Relaxed, Ordering::SeqCst);
     let _ = x.compare_exchange(0, 0, Ordering::Acquire, Ordering::Relaxed);
+    let _ = x.compare_exchange(0, 0, Ordering::Acquire, Ordering::Acquire);
+    let _ = x.compare_exchange(0, 0, Ordering::Acquire, Ordering::SeqCst);
     let _ = x.compare_exchange(0, 0, Ordering::Release, Ordering::Relaxed);
-    let _ = x.compare_exchange(0, 0, Ordering::AcqRel, Ordering::Acquire);
+    let _ = x.compare_exchange(0, 0, Ordering::Release, Ordering::Acquire);
+    let _ = x.compare_exchange(0, 0, Ordering::Release, Ordering::SeqCst);
     let _ = x.compare_exchange(0, 0, Ordering::AcqRel, Ordering::Relaxed);
+    let _ = x.compare_exchange(0, 0, Ordering::AcqRel, Ordering::Acquire);
+    let _ = x.compare_exchange(0, 0, Ordering::AcqRel, Ordering::SeqCst);
     let _ = x.compare_exchange(0, 0, Ordering::SeqCst, Ordering::Relaxed);
     let _ = x.compare_exchange(0, 0, Ordering::SeqCst, Ordering::Acquire);
     let _ = x.compare_exchange(0, 0, Ordering::SeqCst, Ordering::SeqCst);
@@ -39,22 +45,4 @@ fn main() {
     //~^ ERROR `compare_exchange`'s failure ordering may not be `Release` or `AcqRel`
     let _ = x.compare_exchange(0, 0, Ordering::SeqCst, Ordering::Release);
     //~^ ERROR `compare_exchange`'s failure ordering may not be `Release` or `AcqRel`
-
-    // Release success order forbids failure order of Acquire or SeqCst
-    let _ = x.compare_exchange(0, 0, Ordering::Release, Ordering::Acquire);
-    //~^ ERROR `compare_exchange`'s success ordering must be at least as strong as
-    let _ = x.compare_exchange(0, 0, Ordering::Release, Ordering::SeqCst);
-    //~^ ERROR `compare_exchange`'s success ordering must be at least as strong as
-
-    // Relaxed success order also forbids failure order of Acquire or SeqCst
-    let _ = x.compare_exchange(0, 0, Ordering::Relaxed, Ordering::SeqCst);
-    //~^ ERROR `compare_exchange`'s success ordering must be at least as strong as
-    let _ = x.compare_exchange(0, 0, Ordering::Relaxed, Ordering::Acquire);
-    //~^ ERROR `compare_exchange`'s success ordering must be at least as strong as
-
-    // Acquire/AcqRel forbids failure order of SeqCst
-    let _ = x.compare_exchange(0, 0, Ordering::Acquire, Ordering::SeqCst);
-    //~^ ERROR `compare_exchange`'s success ordering must be at least as strong as
-    let _ = x.compare_exchange(0, 0, Ordering::AcqRel, Ordering::SeqCst);
-    //~^ ERROR `compare_exchange`'s success ordering must be at least as strong as
 }