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add call_missing_target_feature lint
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‎CHANGELOG.md

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@@ -5417,6 +5417,7 @@ Released 2018-09-13
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[`byte_char_slices`]: https://rust-lang.github.io/rust-clippy/master/index.html#byte_char_slices
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[`bytes_count_to_len`]: https://rust-lang.github.io/rust-clippy/master/index.html#bytes_count_to_len
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[`bytes_nth`]: https://rust-lang.github.io/rust-clippy/master/index.html#bytes_nth
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[`call_missing_target_feature`]: https://rust-lang.github.io/rust-clippy/master/index.html#call_missing_target_feature
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[`cargo_common_metadata`]: https://rust-lang.github.io/rust-clippy/master/index.html#cargo_common_metadata
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[`case_sensitive_file_extension_comparisons`]: https://rust-lang.github.io/rust-clippy/master/index.html#case_sensitive_file_extension_comparisons
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[`cast_abs_to_unsigned`]: https://rust-lang.github.io/rust-clippy/master/index.html#cast_abs_to_unsigned

‎clippy_lints/src/call_missing_target_feature.rs

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#![allow(clippy::similar_names)]
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use clippy_utils::diagnostics::span_lint_and_then;
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use rustc_hir as hir;
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use rustc_hir::def::Res;
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use rustc_hir::def_id::DefId;
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use rustc_lint::{LateContext, LateLintPass};
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use rustc_middle::lint::in_external_macro;
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use rustc_session::declare_lint_pass;
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declare_clippy_lint! {
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/// ### What it does
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/// Checks that the caller enables the target features that the callee requires
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///
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/// ### Why is this bad?
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/// Not enabling target features can cause UB and limits optimization opportunities.
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///
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/// ### Example
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/// ```no_run
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/// #[target_feature(enable = "avx2")]
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/// unsafe fn f() -> u32 {
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/// 0
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/// }
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///
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/// fn g() {
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/// unsafe { f() };
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/// // g does not enable the target features f requires
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/// }
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/// ```
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#[clippy::version = "1.82.0"]
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pub CALL_MISSING_TARGET_FEATURE,
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suspicious,
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"call requires target features that the surrounding function does not enable"
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}
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declare_lint_pass!(CallMissingTargetFeature => [CALL_MISSING_TARGET_FEATURE]);
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impl<'tcx> LateLintPass<'tcx> for CallMissingTargetFeature {
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fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &hir::Expr<'tcx>) {
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let Some(callee_def_id) = callee_def_id(cx, expr) else {
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return;
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};
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let callee_target_features = &cx.tcx.codegen_fn_attrs(callee_def_id).target_features;
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if callee_target_features.is_empty() {
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return;
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}
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let Some(caller_body_id) = cx.enclosing_body else {
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return;
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};
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let caller_def_id = cx.tcx.hir().body_owner_def_id(caller_body_id);
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let caller_target_features = &cx.tcx.codegen_fn_attrs(caller_def_id).target_features;
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if in_external_macro(cx.tcx.sess, expr.span) {
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return;
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}
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// target features can imply other target features (e.g. avx2 implies sse4.2). We can safely skip
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// implied target features and only warn for the more general missing target feature.
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let missing: Vec<_> = callee_target_features
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.iter()
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.filter_map(|target_feature| {
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if target_feature.implied || caller_target_features.iter().any(|tf| tf.name == target_feature.name) {
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None
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} else {
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Some(target_feature.name.as_str())
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}
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})
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.collect();
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if missing.is_empty() {
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return;
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}
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let attr = format!("#[target_feature(enable = \"{}\")]", missing.join(","));
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span_lint_and_then(
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cx,
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CALL_MISSING_TARGET_FEATURE,
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expr.span,
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"this call requires target features that the surrounding function does not enable",
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|diag| {
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diag.span_label(
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expr.span,
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"this function call requires target features to be enabled".to_string(),
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);
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let fn_sig = cx.tcx.fn_sig(caller_def_id).skip_binder();
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let mut suggestions = Vec::with_capacity(2);
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let hir::Node::Item(caller_item) = cx.tcx.hir_node_by_def_id(caller_def_id) else {
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return;
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};
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let Some(indent) = clippy_utils::source::snippet_indent(cx, caller_item.span) else {
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return;
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};
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let lo_span = caller_item.span.with_hi(caller_item.span.lo());
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match fn_sig.safety() {
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hir::Safety::Safe => {
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// the `target_feature` attribute can only be applied to unsafe functions
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if caller_item.vis_span.is_empty() {
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suggestions.push((lo_span, format!("{attr}\n{indent}unsafe ")));
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} else {
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suggestions.push((lo_span, format!("{attr}\n{indent}")));
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suggestions.push((caller_item.vis_span.shrink_to_hi(), " unsafe".to_string()));
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}
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},
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hir::Safety::Unsafe => {
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suggestions.push((lo_span, format!("{attr}\n{indent}")));
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},
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}
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diag.multipart_suggestion_verbose(
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"add the missing target features to the surrounding function",
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suggestions,
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rustc_errors::Applicability::MaybeIncorrect,
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);
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},
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);
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}
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}
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fn callee_def_id(cx: &LateContext<'_>, expr: &hir::Expr<'_>) -> Option<DefId> {
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match expr.kind {
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hir::ExprKind::Call(path, _) => {
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if let hir::ExprKind::Path(ref qpath) = path.kind
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&& let Res::Def(_, did) = cx.qpath_res(qpath, path.hir_id)
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{
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Some(did)
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} else {
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None
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}
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},
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hir::ExprKind::MethodCall(..) => cx.typeck_results().type_dependent_def_id(expr.hir_id),
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_ => None,
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}
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}

‎clippy_lints/src/declared_lints.rs

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@@ -69,6 +69,7 @@ pub static LINTS: &[&crate::LintInfo] = &[
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crate::borrow_deref_ref::BORROW_DEREF_REF_INFO,
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crate::box_default::BOX_DEFAULT_INFO,
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crate::byte_char_slices::BYTE_CHAR_SLICES_INFO,
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crate::call_missing_target_feature::CALL_MISSING_TARGET_FEATURE_INFO,
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crate::cargo::CARGO_COMMON_METADATA_INFO,
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crate::cargo::LINT_GROUPS_PRIORITY_INFO,
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crate::cargo::MULTIPLE_CRATE_VERSIONS_INFO,

‎clippy_lints/src/lib.rs

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@@ -92,6 +92,7 @@ mod booleans;
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mod borrow_deref_ref;
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mod box_default;
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mod byte_char_slices;
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mod call_missing_target_feature;
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mod cargo;
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mod casts;
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mod cfg_not_test;
@@ -784,6 +785,7 @@ pub fn register_lints(store: &mut rustc_lint::LintStore, conf: &'static Conf) {
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store.register_late_pass(|_| Box::new(floating_point_arithmetic::FloatingPointArithmetic));
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store.register_late_pass(|_| Box::new(as_conversions::AsConversions));
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store.register_late_pass(|_| Box::new(let_underscore::LetUnderscore));
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store.register_late_pass(|_| Box::new(call_missing_target_feature::CallMissingTargetFeature));
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store.register_early_pass(|| Box::<single_component_path_imports::SingleComponentPathImports>::default());
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store.register_late_pass(move |_| Box::new(excessive_bools::ExcessiveBools::new(conf)));
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store.register_early_pass(|| Box::new(option_env_unwrap::OptionEnvUnwrap));

‎tests/ui/call_missing_target_feature.fixed

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//@only-target: x86_64
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#![allow(clippy::missing_safety_doc)]
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#[target_feature(enable = "avx2")]
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pub unsafe fn test_f() {
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unsafe { f() };
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//~^ ERROR: this call requires target features
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}
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#[target_feature(enable = "avx2,pclmulqdq")]
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pub(crate) unsafe fn test_g() {
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unsafe { g() };
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//~^ ERROR: this call requires target features
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}
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#[target_feature(enable = "avx2,pclmulqdq")]
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unsafe fn test_h() {
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unsafe { h() };
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//~^ ERROR: this call requires target features
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}
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#[target_feature(enable = "avx2,pclmulqdq")]
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unsafe fn test_h_unsafe() {
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unsafe { h() };
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//~^ ERROR: this call requires target features
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}
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#[target_feature(enable = "avx2")]
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unsafe fn f() -> u32 {
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0
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}
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#[target_feature(enable = "avx2,pclmulqdq")]
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unsafe fn g() -> u32 {
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0
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}
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#[target_feature(enable = "avx2")]
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#[target_feature(enable = "pclmulqdq")]
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unsafe fn h() -> u32 {
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0
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}

‎tests/ui/call_missing_target_feature.rs

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//@only-target: x86_64
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#![allow(clippy::missing_safety_doc)]
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pub fn test_f() {
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unsafe { f() };
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//~^ ERROR: this call requires target features
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}
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pub(crate) fn test_g() {
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unsafe { g() };
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//~^ ERROR: this call requires target features
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}
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fn test_h() {
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unsafe { h() };
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//~^ ERROR: this call requires target features
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}
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unsafe fn test_h_unsafe() {
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unsafe { h() };
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//~^ ERROR: this call requires target features
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}
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#[target_feature(enable = "avx2")]
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unsafe fn f() -> u32 {
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0
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}
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#[target_feature(enable = "avx2,pclmulqdq")]
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unsafe fn g() -> u32 {
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0
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}
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#[target_feature(enable = "avx2")]
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#[target_feature(enable = "pclmulqdq")]
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unsafe fn h() -> u32 {
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0
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}

‎tests/ui/call_missing_target_feature.stderr

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error: this call requires target features that the surrounding function does not enable
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--> tests/ui/call_missing_target_feature.rs:5:14
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|
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LL | unsafe { f() };
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| ^^^ this function call requires target features to be enabled
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|
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= note: `-D clippy::call-missing-target-feature` implied by `-D warnings`
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= help: to override `-D warnings` add `#[allow(clippy::call_missing_target_feature)]`
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help: add the missing target features to the surrounding function
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|
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LL + #[target_feature(enable = "avx2")]
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LL ~ pub unsafe fn test_f() {
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|
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error: this call requires target features that the surrounding function does not enable
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--> tests/ui/call_missing_target_feature.rs:10:14
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|
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LL | unsafe { g() };
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| ^^^ this function call requires target features to be enabled
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|
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help: add the missing target features to the surrounding function
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|
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LL + #[target_feature(enable = "avx2,pclmulqdq")]
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LL ~ pub(crate) unsafe fn test_g() {
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|
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error: this call requires target features that the surrounding function does not enable
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--> tests/ui/call_missing_target_feature.rs:15:14
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|
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LL | unsafe { h() };
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| ^^^ this function call requires target features to be enabled
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|
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help: add the missing target features to the surrounding function
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|
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LL + #[target_feature(enable = "avx2,pclmulqdq")]
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LL ~ unsafe fn test_h() {
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|
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error: this call requires target features that the surrounding function does not enable
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--> tests/ui/call_missing_target_feature.rs:20:14
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|
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LL | unsafe { h() };
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| ^^^ this function call requires target features to be enabled
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|
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help: add the missing target features to the surrounding function
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|
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LL + #[target_feature(enable = "avx2,pclmulqdq")]
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LL | unsafe fn test_h_unsafe() {
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|
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error: aborting due to 4 previous errors
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