Auto merge of #9546 - kraktus:default_not_default_trait, r=xFrednet

[rust.git] / clippy_lints / src / non_copy_const.rs

diff --git a/clippy_lints/src/non_copy_const.rs b/clippy_lints/src/non_copy_const.rs
index 7163cfe5e3a2c774911023904da8de297ebc346a..ea76ce2c57357c7183e70cdfb97042674c5e0e1b 100644 (file)
--- a/clippy_lints/src/non_copy_const.rs
+++ b/clippy_lints/src/non_copy_const.rs
@@ -6,6 +6,7 @@
 
 use clippy_utils::diagnostics::span_lint_and_then;
 use clippy_utils::in_constant;
+use clippy_utils::macros::macro_backtrace;
 use if_chain::if_chain;
 use rustc_hir::def::{DefKind, Res};
 use rustc_hir::def_id::DefId;
@@ -18,7 +19,7 @@
 use rustc_middle::ty::adjustment::Adjust;
 use rustc_middle::ty::{self, Ty};
 use rustc_session::{declare_lint_pass, declare_tool_lint};
-use rustc_span::{InnerSpan, Span, DUMMY_SP};
+use rustc_span::{sym, InnerSpan, Span, DUMMY_SP};
 use rustc_typeck::hir_ty_to_ty;
 
 // FIXME: this is a correctness problem but there's no suitable
@@ -59,12 +60,14 @@
     /// ```rust
     /// use std::sync::atomic::{AtomicUsize, Ordering::SeqCst};
     ///
-    /// // Bad.
     /// const CONST_ATOM: AtomicUsize = AtomicUsize::new(12);
     /// CONST_ATOM.store(6, SeqCst); // the content of the atomic is unchanged
     /// assert_eq!(CONST_ATOM.load(SeqCst), 12); // because the CONST_ATOM in these lines are distinct
+    /// ```
     ///
-    /// // Good.
+    /// Use instead:
+    /// ```rust
+    /// # use std::sync::atomic::{AtomicUsize, Ordering::SeqCst};
     /// static STATIC_ATOM: AtomicUsize = AtomicUsize::new(15);
     /// STATIC_ATOM.store(9, SeqCst);
     /// assert_eq!(STATIC_ATOM.load(SeqCst), 9); // use a `static` item to refer to the same instance
@@ -105,11 +108,15 @@
     /// use std::sync::atomic::{AtomicUsize, Ordering::SeqCst};
     /// const CONST_ATOM: AtomicUsize = AtomicUsize::new(12);
     ///
-    /// // Bad.
     /// CONST_ATOM.store(6, SeqCst); // the content of the atomic is unchanged
     /// assert_eq!(CONST_ATOM.load(SeqCst), 12); // because the CONST_ATOM in these lines are distinct
+    /// ```
+    ///
+    /// Use instead:
+    /// ```rust
+    /// use std::sync::atomic::{AtomicUsize, Ordering::SeqCst};
+    /// const CONST_ATOM: AtomicUsize = AtomicUsize::new(12);
     ///
-    /// // Good.
     /// static STATIC_ATOM: AtomicUsize = CONST_ATOM;
     /// STATIC_ATOM.store(9, SeqCst);
     /// assert_eq!(STATIC_ATOM.load(SeqCst), 9); // use a `static` item to refer to the same instance
@@ -141,7 +148,10 @@ fn inner<'tcx>(cx: &LateContext<'tcx>, val: mir::ConstantKind<'tcx>) -> bool {
         match val.ty().kind() {
             // the fact that we have to dig into every structs to search enums
             // leads us to the point checking `UnsafeCell` directly is the only option.
-            ty::Adt(ty_def, ..) if Some(ty_def.did()) == cx.tcx.lang_items().unsafe_cell_type() => true,
+            ty::Adt(ty_def, ..) if ty_def.is_unsafe_cell() => true,
+            // As of 2022-09-08 miri doesn't track which union field is active so there's no safe way to check the
+            // contained value.
+            ty::Adt(def, ..) if def.is_union() => false,
             ty::Array(..) | ty::Adt(..) | ty::Tuple(..) => {
                 let val = cx.tcx.destructure_mir_constant(cx.param_env, val);
                 val.fields.iter().any(|field| inner(cx, *field))
@@ -244,8 +254,7 @@ impl<'tcx> LateLintPass<'tcx> for NonCopyConst {
     fn check_item(&mut self, cx: &LateContext<'tcx>, it: &'tcx Item<'_>) {
         if let ItemKind::Const(hir_ty, body_id) = it.kind {
             let ty = hir_ty_to_ty(cx.tcx, hir_ty);
-
-            if is_unfrozen(cx, ty) && is_value_unfrozen_poly(cx, body_id, ty) {
+            if !ignored_macro(cx, it) && is_unfrozen(cx, ty) && is_value_unfrozen_poly(cx, body_id, ty) {
                 lint(cx, Source::Item { item: it.span });
             }
         }
@@ -432,3 +441,12 @@ fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
         }
     }
 }
+
+fn ignored_macro(cx: &LateContext<'_>, it: &rustc_hir::Item<'_>) -> bool {
+    macro_backtrace(it.span).any(|macro_call| {
+        matches!(
+            cx.tcx.get_diagnostic_name(macro_call.def_id),
+            Some(sym::thread_local_macro)
+        )
+    })
+}