From 6211599ccafee5b2429bfb1bbeb48ead32a48484 Mon Sep 17 00:00:00 2001 From: Thom Chiovoloni Date: Wed, 9 Sep 2020 14:00:31 -0700 Subject: [PATCH] Extend invalid_atomic_ordering to detect misuse of compare_exchange{,_weak} --- clippy_lints/src/atomic_ordering.rs | 82 ++++++- tests/ui/atomic_ordering_exchange.rs | 84 ++++++++ tests/ui/atomic_ordering_exchange.stderr | 259 +++++++++++++++++++++++ 3 files changed, 423 insertions(+), 2 deletions(-) create mode 100644 tests/ui/atomic_ordering_exchange.rs create mode 100644 tests/ui/atomic_ordering_exchange.stderr diff --git a/clippy_lints/src/atomic_ordering.rs b/clippy_lints/src/atomic_ordering.rs index 2d964ac2b9f6..748f45f47c2a 100644 --- a/clippy_lints/src/atomic_ordering.rs +++ b/clippy_lints/src/atomic_ordering.rs @@ -8,7 +8,7 @@ use rustc_session::{declare_lint_pass, declare_tool_lint}; declare_clippy_lint! { /// **What it does:** Checks for usage of invalid atomic - /// ordering in atomic loads/stores and memory fences. + /// ordering in atomic loads/stores/exchanges and memory fences /// /// **Why is this bad?** Using an invalid atomic ordering /// will cause a panic at run-time. @@ -29,10 +29,13 @@ declare_clippy_lint! { /// /// atomic::fence(Ordering::Relaxed); /// atomic::compiler_fence(Ordering::Relaxed); + /// + /// let _ = x.compare_exchange(false, false, Ordering::Relaxed, Ordering::SeqCst); + /// let _ = x.compare_exchange_weak(false, true, Ordering::SeqCst, Ordering::Release); /// ``` pub INVALID_ATOMIC_ORDERING, correctness, - "usage of invalid atomic ordering in atomic loads/stores and memory fences" + "usage of invalid atomic ordering in atomic loads/stores/exchanges ane memory fences" } declare_lint_pass!(AtomicOrdering => [INVALID_ATOMIC_ORDERING]); @@ -127,9 +130,84 @@ fn check_memory_fence(cx: &LateContext<'_>, expr: &Expr<'_>) { } } +fn opt_ordering_defid(cx: &LateContext<'_>, ord_arg: &Expr<'_>) -> Option { + if let ExprKind::Path(ref ord_qpath) = ord_arg.kind { + cx.qpath_res(ord_qpath, ord_arg.hir_id).opt_def_id() + } else { + None + } +} +fn check_atomic_compare_exchange(cx: &LateContext<'_>, expr: &Expr<'_>) { + if_chain! { + if let ExprKind::MethodCall(ref method_path, _, args, _) = &expr.kind; + let method = method_path.ident.name.as_str(); + if type_is_atomic(cx, &args[0]); + if method == "compare_exchange" || method == "compare_exchange_weak"; + let failure_order_arg = &args[4]; + if let Some(fail_ordering_def_id) = opt_ordering_defid(cx, failure_order_arg); + then { + // Helper type holding on to some checking and error reporting data. Has + // - (success ordering name, + // - list of failure orderings forbidden by the success order, + // - suggestion message) + type OrdLintInfo = (&'static str, &'static [&'static str], &'static str); + let relaxed: OrdLintInfo = ("Relaxed", &["SeqCst", "Acquire"], "ordering mode `Relaxed`"); + let acquire: OrdLintInfo = ("Acquire", &["SeqCst"], "ordering modes `Acquire` or `Relaxed`"); + let seq_cst: OrdLintInfo = ("SeqCst", &[], "ordering modes `Acquire`, `SeqCst` or `Relaxed`"); + let release = ("Release", relaxed.1, relaxed.2); + let acqrel = ("AcqRel", acquire.1, acquire.2); + let search = [relaxed, acquire, seq_cst, release, acqrel]; + + let success_lint_info = opt_ordering_defid(cx, &args[3]) + .and_then(|success_ord_def_id| -> Option { + search + .iter() + .find(|(ordering, ..)| { + match_def_path(cx, success_ord_def_id, + &["core", "sync", "atomic", "Ordering", ordering]) + }) + .copied() + }); + + if match_ordering_def_path(cx, fail_ordering_def_id, &["Release", "AcqRel"]) { + // If we don't know the success order is, use what we'd suggest + // if it were maximally permissive. + let suggested = success_lint_info.unwrap_or(seq_cst).2; + span_lint_and_help( + cx, + INVALID_ATOMIC_ORDERING, + failure_order_arg.span, + &format!( + "{}'s failure ordering may not be `Release` or `AcqRel`", + method, + ), + None, + &format!("consider using {} instead", suggested), + ); + } else if let Some((success_ord_name, bad_ords_given_success, suggested)) = success_lint_info { + if match_ordering_def_path(cx, fail_ordering_def_id, bad_ords_given_success) { + span_lint_and_help( + cx, + INVALID_ATOMIC_ORDERING, + failure_order_arg.span, + &format!( + "{}'s failure ordering may not stronger than the success ordering of `{}`", + method, + success_ord_name, + ), + None, + &format!("consider using {} instead", suggested), + ); + } + } + } + } +} + impl<'tcx> LateLintPass<'tcx> for AtomicOrdering { fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) { check_atomic_load_store(cx, expr); check_memory_fence(cx, expr); + check_atomic_compare_exchange(cx, expr); } } diff --git a/tests/ui/atomic_ordering_exchange.rs b/tests/ui/atomic_ordering_exchange.rs new file mode 100644 index 000000000000..2f60a98f037b --- /dev/null +++ b/tests/ui/atomic_ordering_exchange.rs @@ -0,0 +1,84 @@ +#![warn(clippy::invalid_atomic_ordering)] + +use std::sync::atomic::{AtomicUsize, Ordering}; + +fn main() { + // `compare_exchange` (not weak) testing + let x = AtomicUsize::new(0); + + // 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::Acquire, Ordering::Relaxed); + 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::AcqRel, Ordering::Relaxed); + 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); + + // AcqRel is always forbidden as a failure ordering + let _ = x.compare_exchange(0, 0, Ordering::Relaxed, Ordering::AcqRel); + let _ = x.compare_exchange(0, 0, Ordering::Acquire, Ordering::AcqRel); + let _ = x.compare_exchange(0, 0, Ordering::Release, Ordering::AcqRel); + let _ = x.compare_exchange(0, 0, Ordering::AcqRel, Ordering::AcqRel); + let _ = x.compare_exchange(0, 0, Ordering::SeqCst, Ordering::AcqRel); + + // Release is always forbidden as a failure ordering + let _ = x.compare_exchange(0, 0, Ordering::Relaxed, Ordering::Release); + let _ = x.compare_exchange(0, 0, Ordering::Acquire, Ordering::Release); + let _ = x.compare_exchange(0, 0, Ordering::Release, Ordering::Release); + let _ = x.compare_exchange(0, 0, Ordering::AcqRel, Ordering::Release); + let _ = x.compare_exchange(0, 0, Ordering::SeqCst, Ordering::Release); + + // Release success order forbids failure order of Acquire or SeqCst + let _ = x.compare_exchange(0, 0, Ordering::Release, Ordering::Acquire); + let _ = x.compare_exchange(0, 0, Ordering::Release, Ordering::SeqCst); + + // Relaxed success order also forbids failure order of Acquire or SeqCst + let _ = x.compare_exchange(0, 0, Ordering::Relaxed, Ordering::SeqCst); + let _ = x.compare_exchange(0, 0, Ordering::Relaxed, Ordering::Acquire); + + // Acquire/AcqRel forbids failure order of SeqCst + let _ = x.compare_exchange(0, 0, Ordering::Acquire, Ordering::SeqCst); + let _ = x.compare_exchange(0, 0, Ordering::AcqRel, Ordering::SeqCst); + + // compare_exchange_weak tests + + // Allowed ordering combos + let _ = x.compare_exchange_weak(0, 0, Ordering::Relaxed, Ordering::Relaxed); + let _ = x.compare_exchange_weak(0, 0, Ordering::Acquire, Ordering::Acquire); + let _ = x.compare_exchange_weak(0, 0, Ordering::Acquire, Ordering::Relaxed); + let _ = x.compare_exchange_weak(0, 0, Ordering::Release, Ordering::Relaxed); + let _ = x.compare_exchange_weak(0, 0, Ordering::AcqRel, Ordering::Acquire); + let _ = x.compare_exchange_weak(0, 0, Ordering::AcqRel, Ordering::Relaxed); + let _ = x.compare_exchange_weak(0, 0, Ordering::SeqCst, Ordering::Relaxed); + let _ = x.compare_exchange_weak(0, 0, Ordering::SeqCst, Ordering::Acquire); + let _ = x.compare_exchange_weak(0, 0, Ordering::SeqCst, Ordering::SeqCst); + + // AcqRel is always forbidden as a failure ordering + let _ = x.compare_exchange_weak(0, 0, Ordering::Relaxed, Ordering::AcqRel); + let _ = x.compare_exchange_weak(0, 0, Ordering::Acquire, Ordering::AcqRel); + let _ = x.compare_exchange_weak(0, 0, Ordering::Release, Ordering::AcqRel); + let _ = x.compare_exchange_weak(0, 0, Ordering::AcqRel, Ordering::AcqRel); + let _ = x.compare_exchange_weak(0, 0, Ordering::SeqCst, Ordering::AcqRel); + + // Release is always forbidden as a failure ordering + let _ = x.compare_exchange_weak(0, 0, Ordering::Relaxed, Ordering::Release); + let _ = x.compare_exchange_weak(0, 0, Ordering::Acquire, Ordering::Release); + let _ = x.compare_exchange_weak(0, 0, Ordering::Release, Ordering::Release); + let _ = x.compare_exchange_weak(0, 0, Ordering::AcqRel, Ordering::Release); + let _ = x.compare_exchange_weak(0, 0, Ordering::SeqCst, Ordering::Release); + + // Release success order forbids failure order of Acquire or SeqCst + let _ = x.compare_exchange_weak(0, 0, Ordering::Release, Ordering::Acquire); + let _ = x.compare_exchange_weak(0, 0, Ordering::Release, Ordering::SeqCst); + + // Relaxed success order also forbids failure order of Acquire or SeqCst + let _ = x.compare_exchange_weak(0, 0, Ordering::Relaxed, Ordering::SeqCst); + let _ = x.compare_exchange_weak(0, 0, Ordering::Relaxed, Ordering::Acquire); + + // Acquire/AcqRel forbids failure order of SeqCst + let _ = x.compare_exchange_weak(0, 0, Ordering::Acquire, Ordering::SeqCst); + let _ = x.compare_exchange_weak(0, 0, Ordering::AcqRel, Ordering::SeqCst); +} diff --git a/tests/ui/atomic_ordering_exchange.stderr b/tests/ui/atomic_ordering_exchange.stderr new file mode 100644 index 000000000000..26ec15be518c --- /dev/null +++ b/tests/ui/atomic_ordering_exchange.stderr @@ -0,0 +1,259 @@ +error: compare_exchange's failure ordering may not be `Release` or `AcqRel` + --> $DIR/atomic_ordering_exchange.rs:21:57 + | +LL | let _ = x.compare_exchange(0, 0, Ordering::Relaxed, Ordering::AcqRel); + | ^^^^^^^^^^^^^^^^ + | + = note: `-D clippy::invalid-atomic-ordering` implied by `-D warnings` + = help: consider using ordering mode `Relaxed` instead + +error: compare_exchange's failure ordering may not be `Release` or `AcqRel` + --> $DIR/atomic_ordering_exchange.rs:22:57 + | +LL | let _ = x.compare_exchange(0, 0, Ordering::Acquire, Ordering::AcqRel); + | ^^^^^^^^^^^^^^^^ + | + = help: consider using ordering modes `Acquire` or `Relaxed` instead + +error: compare_exchange's failure ordering may not be `Release` or `AcqRel` + --> $DIR/atomic_ordering_exchange.rs:23:57 + | +LL | let _ = x.compare_exchange(0, 0, Ordering::Release, Ordering::AcqRel); + | ^^^^^^^^^^^^^^^^ + | + = help: consider using ordering mode `Relaxed` instead + +error: compare_exchange's failure ordering may not be `Release` or `AcqRel` + --> $DIR/atomic_ordering_exchange.rs:24:56 + | +LL | let _ = x.compare_exchange(0, 0, Ordering::AcqRel, Ordering::AcqRel); + | ^^^^^^^^^^^^^^^^ + | + = help: consider using ordering modes `Acquire` or `Relaxed` instead + +error: compare_exchange's failure ordering may not be `Release` or `AcqRel` + --> $DIR/atomic_ordering_exchange.rs:25:56 + | +LL | let _ = x.compare_exchange(0, 0, Ordering::SeqCst, Ordering::AcqRel); + | ^^^^^^^^^^^^^^^^ + | + = help: consider using ordering modes `Acquire`, `SeqCst` or `Relaxed` instead + +error: compare_exchange's failure ordering may not be `Release` or `AcqRel` + --> $DIR/atomic_ordering_exchange.rs:28:57 + | +LL | let _ = x.compare_exchange(0, 0, Ordering::Relaxed, Ordering::Release); + | ^^^^^^^^^^^^^^^^^ + | + = help: consider using ordering mode `Relaxed` instead + +error: compare_exchange's failure ordering may not be `Release` or `AcqRel` + --> $DIR/atomic_ordering_exchange.rs:29:57 + | +LL | let _ = x.compare_exchange(0, 0, Ordering::Acquire, Ordering::Release); + | ^^^^^^^^^^^^^^^^^ + | + = help: consider using ordering modes `Acquire` or `Relaxed` instead + +error: compare_exchange's failure ordering may not be `Release` or `AcqRel` + --> $DIR/atomic_ordering_exchange.rs:30:57 + | +LL | let _ = x.compare_exchange(0, 0, Ordering::Release, Ordering::Release); + | ^^^^^^^^^^^^^^^^^ + | + = help: consider using ordering mode `Relaxed` instead + +error: compare_exchange's failure ordering may not be `Release` or `AcqRel` + --> $DIR/atomic_ordering_exchange.rs:31:56 + | +LL | let _ = x.compare_exchange(0, 0, Ordering::AcqRel, Ordering::Release); + | ^^^^^^^^^^^^^^^^^ + | + = help: consider using ordering modes `Acquire` or `Relaxed` instead + +error: compare_exchange's failure ordering may not be `Release` or `AcqRel` + --> $DIR/atomic_ordering_exchange.rs:32:56 + | +LL | let _ = x.compare_exchange(0, 0, Ordering::SeqCst, Ordering::Release); + | ^^^^^^^^^^^^^^^^^ + | + = help: consider using ordering modes `Acquire`, `SeqCst` or `Relaxed` instead + +error: compare_exchange's failure ordering may not stronger than the success ordering of `Release` + --> $DIR/atomic_ordering_exchange.rs:35:57 + | +LL | let _ = x.compare_exchange(0, 0, Ordering::Release, Ordering::Acquire); + | ^^^^^^^^^^^^^^^^^ + | + = help: consider using ordering mode `Relaxed` instead + +error: compare_exchange's failure ordering may not stronger than the success ordering of `Release` + --> $DIR/atomic_ordering_exchange.rs:36:57 + | +LL | let _ = x.compare_exchange(0, 0, Ordering::Release, Ordering::SeqCst); + | ^^^^^^^^^^^^^^^^ + | + = help: consider using ordering mode `Relaxed` instead + +error: compare_exchange's failure ordering may not stronger than the success ordering of `Relaxed` + --> $DIR/atomic_ordering_exchange.rs:39:57 + | +LL | let _ = x.compare_exchange(0, 0, Ordering::Relaxed, Ordering::SeqCst); + | ^^^^^^^^^^^^^^^^ + | + = help: consider using ordering mode `Relaxed` instead + +error: compare_exchange's failure ordering may not stronger than the success ordering of `Relaxed` + --> $DIR/atomic_ordering_exchange.rs:40:57 + | +LL | let _ = x.compare_exchange(0, 0, Ordering::Relaxed, Ordering::Acquire); + | ^^^^^^^^^^^^^^^^^ + | + = help: consider using ordering mode `Relaxed` instead + +error: compare_exchange's failure ordering may not stronger than the success ordering of `Acquire` + --> $DIR/atomic_ordering_exchange.rs:43:57 + | +LL | let _ = x.compare_exchange(0, 0, Ordering::Acquire, Ordering::SeqCst); + | ^^^^^^^^^^^^^^^^ + | + = help: consider using ordering modes `Acquire` or `Relaxed` instead + +error: compare_exchange's failure ordering may not stronger than the success ordering of `AcqRel` + --> $DIR/atomic_ordering_exchange.rs:44:56 + | +LL | let _ = x.compare_exchange(0, 0, Ordering::AcqRel, Ordering::SeqCst); + | ^^^^^^^^^^^^^^^^ + | + = help: consider using ordering modes `Acquire` or `Relaxed` instead + +error: compare_exchange_weak's failure ordering may not be `Release` or `AcqRel` + --> $DIR/atomic_ordering_exchange.rs:60:62 + | +LL | let _ = x.compare_exchange_weak(0, 0, Ordering::Relaxed, Ordering::AcqRel); + | ^^^^^^^^^^^^^^^^ + | + = help: consider using ordering mode `Relaxed` instead + +error: compare_exchange_weak's failure ordering may not be `Release` or `AcqRel` + --> $DIR/atomic_ordering_exchange.rs:61:62 + | +LL | let _ = x.compare_exchange_weak(0, 0, Ordering::Acquire, Ordering::AcqRel); + | ^^^^^^^^^^^^^^^^ + | + = help: consider using ordering modes `Acquire` or `Relaxed` instead + +error: compare_exchange_weak's failure ordering may not be `Release` or `AcqRel` + --> $DIR/atomic_ordering_exchange.rs:62:62 + | +LL | let _ = x.compare_exchange_weak(0, 0, Ordering::Release, Ordering::AcqRel); + | ^^^^^^^^^^^^^^^^ + | + = help: consider using ordering mode `Relaxed` instead + +error: compare_exchange_weak's failure ordering may not be `Release` or `AcqRel` + --> $DIR/atomic_ordering_exchange.rs:63:61 + | +LL | let _ = x.compare_exchange_weak(0, 0, Ordering::AcqRel, Ordering::AcqRel); + | ^^^^^^^^^^^^^^^^ + | + = help: consider using ordering modes `Acquire` or `Relaxed` instead + +error: compare_exchange_weak's failure ordering may not be `Release` or `AcqRel` + --> $DIR/atomic_ordering_exchange.rs:64:61 + | +LL | let _ = x.compare_exchange_weak(0, 0, Ordering::SeqCst, Ordering::AcqRel); + | ^^^^^^^^^^^^^^^^ + | + = help: consider using ordering modes `Acquire`, `SeqCst` or `Relaxed` instead + +error: compare_exchange_weak's failure ordering may not be `Release` or `AcqRel` + --> $DIR/atomic_ordering_exchange.rs:67:62 + | +LL | let _ = x.compare_exchange_weak(0, 0, Ordering::Relaxed, Ordering::Release); + | ^^^^^^^^^^^^^^^^^ + | + = help: consider using ordering mode `Relaxed` instead + +error: compare_exchange_weak's failure ordering may not be `Release` or `AcqRel` + --> $DIR/atomic_ordering_exchange.rs:68:62 + | +LL | let _ = x.compare_exchange_weak(0, 0, Ordering::Acquire, Ordering::Release); + | ^^^^^^^^^^^^^^^^^ + | + = help: consider using ordering modes `Acquire` or `Relaxed` instead + +error: compare_exchange_weak's failure ordering may not be `Release` or `AcqRel` + --> $DIR/atomic_ordering_exchange.rs:69:62 + | +LL | let _ = x.compare_exchange_weak(0, 0, Ordering::Release, Ordering::Release); + | ^^^^^^^^^^^^^^^^^ + | + = help: consider using ordering mode `Relaxed` instead + +error: compare_exchange_weak's failure ordering may not be `Release` or `AcqRel` + --> $DIR/atomic_ordering_exchange.rs:70:61 + | +LL | let _ = x.compare_exchange_weak(0, 0, Ordering::AcqRel, Ordering::Release); + | ^^^^^^^^^^^^^^^^^ + | + = help: consider using ordering modes `Acquire` or `Relaxed` instead + +error: compare_exchange_weak's failure ordering may not be `Release` or `AcqRel` + --> $DIR/atomic_ordering_exchange.rs:71:61 + | +LL | let _ = x.compare_exchange_weak(0, 0, Ordering::SeqCst, Ordering::Release); + | ^^^^^^^^^^^^^^^^^ + | + = help: consider using ordering modes `Acquire`, `SeqCst` or `Relaxed` instead + +error: compare_exchange_weak's failure ordering may not stronger than the success ordering of `Release` + --> $DIR/atomic_ordering_exchange.rs:74:62 + | +LL | let _ = x.compare_exchange_weak(0, 0, Ordering::Release, Ordering::Acquire); + | ^^^^^^^^^^^^^^^^^ + | + = help: consider using ordering mode `Relaxed` instead + +error: compare_exchange_weak's failure ordering may not stronger than the success ordering of `Release` + --> $DIR/atomic_ordering_exchange.rs:75:62 + | +LL | let _ = x.compare_exchange_weak(0, 0, Ordering::Release, Ordering::SeqCst); + | ^^^^^^^^^^^^^^^^ + | + = help: consider using ordering mode `Relaxed` instead + +error: compare_exchange_weak's failure ordering may not stronger than the success ordering of `Relaxed` + --> $DIR/atomic_ordering_exchange.rs:78:62 + | +LL | let _ = x.compare_exchange_weak(0, 0, Ordering::Relaxed, Ordering::SeqCst); + | ^^^^^^^^^^^^^^^^ + | + = help: consider using ordering mode `Relaxed` instead + +error: compare_exchange_weak's failure ordering may not stronger than the success ordering of `Relaxed` + --> $DIR/atomic_ordering_exchange.rs:79:62 + | +LL | let _ = x.compare_exchange_weak(0, 0, Ordering::Relaxed, Ordering::Acquire); + | ^^^^^^^^^^^^^^^^^ + | + = help: consider using ordering mode `Relaxed` instead + +error: compare_exchange_weak's failure ordering may not stronger than the success ordering of `Acquire` + --> $DIR/atomic_ordering_exchange.rs:82:62 + | +LL | let _ = x.compare_exchange_weak(0, 0, Ordering::Acquire, Ordering::SeqCst); + | ^^^^^^^^^^^^^^^^ + | + = help: consider using ordering modes `Acquire` or `Relaxed` instead + +error: compare_exchange_weak's failure ordering may not stronger than the success ordering of `AcqRel` + --> $DIR/atomic_ordering_exchange.rs:83:61 + | +LL | let _ = x.compare_exchange_weak(0, 0, Ordering::AcqRel, Ordering::SeqCst); + | ^^^^^^^^^^^^^^^^ + | + = help: consider using ordering modes `Acquire` or `Relaxed` instead + +error: aborting due to 32 previous errors +