diff --git a/compiler/rustc_builtin_macros/src/deriving/cmp/eq.rs b/compiler/rustc_builtin_macros/src/deriving/cmp/eq.rs index 79f35ad5819..5a4e7fd9d07 100644 --- a/compiler/rustc_builtin_macros/src/deriving/cmp/eq.rs +++ b/compiler/rustc_builtin_macros/src/deriving/cmp/eq.rs @@ -16,9 +16,19 @@ pub fn expand_deriving_eq( push: &mut dyn FnMut(Annotatable), ) { let inline = cx.meta_word(span, sym::inline); + let no_coverage_ident = + rustc_ast::attr::mk_nested_word_item(Ident::new(sym::no_coverage, span)); + let no_coverage_feature = + rustc_ast::attr::mk_list_item(Ident::new(sym::feature, span), vec![no_coverage_ident]); + let no_coverage = cx.meta_word(span, sym::no_coverage); let hidden = rustc_ast::attr::mk_nested_word_item(Ident::new(sym::hidden, span)); let doc = rustc_ast::attr::mk_list_item(Ident::new(sym::doc, span), vec![hidden]); - let attrs = vec![cx.attribute(inline), cx.attribute(doc)]; + let attrs = vec![ + cx.attribute(inline), + cx.attribute(no_coverage_feature), + cx.attribute(no_coverage), + cx.attribute(doc), + ]; let trait_def = TraitDef { span, attributes: Vec::new(), diff --git a/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen.rs b/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen.rs index 2ac814bf228..1faaa7e86f6 100644 --- a/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen.rs +++ b/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen.rs @@ -8,6 +8,7 @@ use rustc_codegen_ssa::traits::{ConstMethods, CoverageInfoMethods}; use rustc_data_structures::fx::{FxHashMap, FxHashSet, FxIndexSet}; use rustc_hir::def_id::{DefId, DefIdSet, LOCAL_CRATE}; use rustc_llvm::RustString; +use rustc_middle::middle::codegen_fn_attrs::CodegenFnAttrFlags; use rustc_middle::mir::coverage::CodeRegion; use rustc_span::Symbol; @@ -280,6 +281,10 @@ fn add_unused_functions<'ll, 'tcx>(cx: &CodegenCx<'ll, 'tcx>) { let mut unused_def_ids_by_file: FxHashMap> = FxHashMap::default(); for &non_codegenned_def_id in all_def_ids.difference(codegenned_def_ids) { + let codegen_fn_attrs = tcx.codegen_fn_attrs(non_codegenned_def_id); + if codegen_fn_attrs.flags.contains(CodegenFnAttrFlags::NO_COVERAGE) { + continue; + } // Make sure the non-codegenned (unused) function has a file_name if let Some(non_codegenned_file_name) = tcx.covered_file_name(non_codegenned_def_id) { let def_ids = diff --git a/compiler/rustc_feature/src/active.rs b/compiler/rustc_feature/src/active.rs index 304d7ede625..9930f51e3f5 100644 --- a/compiler/rustc_feature/src/active.rs +++ b/compiler/rustc_feature/src/active.rs @@ -646,6 +646,10 @@ declare_features! ( /// Allows `extern "wasm" fn` (active, wasm_abi, "1.53.0", Some(83788), None), + /// Allows function attribute `#[no_coverage]`, to bypass coverage + /// instrumentation of that function. + (active, no_coverage, "1.53.0", Some(84605), None), + /// Allows trait bounds in `const fn`. (active, const_fn_trait_bound, "1.53.0", Some(57563), None), diff --git a/compiler/rustc_feature/src/builtin_attrs.rs b/compiler/rustc_feature/src/builtin_attrs.rs index b8a0b8debcd..5474fea9c78 100644 --- a/compiler/rustc_feature/src/builtin_attrs.rs +++ b/compiler/rustc_feature/src/builtin_attrs.rs @@ -273,6 +273,13 @@ pub const BUILTIN_ATTRIBUTES: &[BuiltinAttribute] = &[ template!(List: "address, memory, thread"), experimental!(no_sanitize) ), + ungated!( + // Not exclusively gated at the crate level (though crate-level is + // supported). The feature can alternatively be enabled on individual + // functions. + no_coverage, AssumedUsed, + template!(Word), + ), // FIXME: #14408 assume docs are used since rustdoc looks at them. ungated!(doc, AssumedUsed, template!(List: "hidden|inline|...", NameValueStr: "string")), diff --git a/compiler/rustc_middle/src/middle/codegen_fn_attrs.rs b/compiler/rustc_middle/src/middle/codegen_fn_attrs.rs index 7024d9a3d21..93e7aeaffce 100644 --- a/compiler/rustc_middle/src/middle/codegen_fn_attrs.rs +++ b/compiler/rustc_middle/src/middle/codegen_fn_attrs.rs @@ -89,6 +89,10 @@ bitflags! { /// #[cmse_nonsecure_entry]: with a TrustZone-M extension, declare a /// function as an entry function from Non-Secure code. const CMSE_NONSECURE_ENTRY = 1 << 14; + /// `#[no_coverage]`: indicates that the function should be ignored by + /// the MIR `InstrumentCoverage` pass and not added to the coverage map + /// during codegen. + const NO_COVERAGE = 1 << 15; } } diff --git a/compiler/rustc_mir/src/transform/coverage/mod.rs b/compiler/rustc_mir/src/transform/coverage/mod.rs index 3ef03ec21ad..eaeb44289cf 100644 --- a/compiler/rustc_mir/src/transform/coverage/mod.rs +++ b/compiler/rustc_mir/src/transform/coverage/mod.rs @@ -23,6 +23,7 @@ use rustc_index::vec::IndexVec; use rustc_middle::hir; use rustc_middle::hir::map::blocks::FnLikeNode; use rustc_middle::ich::StableHashingContext; +use rustc_middle::middle::codegen_fn_attrs::CodegenFnAttrFlags; use rustc_middle::mir::coverage::*; use rustc_middle::mir::{ self, BasicBlock, BasicBlockData, Coverage, SourceInfo, Statement, StatementKind, Terminator, @@ -87,6 +88,11 @@ impl<'tcx> MirPass<'tcx> for InstrumentCoverage { _ => {} } + let codegen_fn_attrs = tcx.codegen_fn_attrs(mir_source.def_id()); + if codegen_fn_attrs.flags.contains(CodegenFnAttrFlags::NO_COVERAGE) { + return; + } + trace!("InstrumentCoverage starting for {:?}", mir_source.def_id()); Instrumentor::new(&self.name(), tcx, mir_body).inject_counters(); trace!("InstrumentCoverage starting for {:?}", mir_source.def_id()); diff --git a/compiler/rustc_span/src/symbol.rs b/compiler/rustc_span/src/symbol.rs index 4be187c5208..cb6c72b1317 100644 --- a/compiler/rustc_span/src/symbol.rs +++ b/compiler/rustc_span/src/symbol.rs @@ -781,6 +781,7 @@ symbols! { no, no_builtins, no_core, + no_coverage, no_crate_inject, no_debug, no_default_passes, diff --git a/compiler/rustc_typeck/src/collect.rs b/compiler/rustc_typeck/src/collect.rs index 46ee8245432..190c9d35934 100644 --- a/compiler/rustc_typeck/src/collect.rs +++ b/compiler/rustc_typeck/src/collect.rs @@ -2661,6 +2661,8 @@ fn codegen_fn_attrs(tcx: TyCtxt<'_>, id: DefId) -> CodegenFnAttrs { let mut inline_span = None; let mut link_ordinal_span = None; let mut no_sanitize_span = None; + let mut no_coverage_feature_enabled = false; + let mut no_coverage_attr = None; for attr in attrs.iter() { if tcx.sess.check_name(attr, sym::cold) { codegen_fn_attrs.flags |= CodegenFnAttrFlags::COLD; @@ -2724,6 +2726,15 @@ fn codegen_fn_attrs(tcx: TyCtxt<'_>, id: DefId) -> CodegenFnAttrs { codegen_fn_attrs.flags |= CodegenFnAttrFlags::NAKED; } else if tcx.sess.check_name(attr, sym::no_mangle) { codegen_fn_attrs.flags |= CodegenFnAttrFlags::NO_MANGLE; + } else if attr.has_name(sym::feature) { + if let Some(list) = attr.meta_item_list() { + if list.iter().any(|nested_meta_item| nested_meta_item.has_name(sym::no_coverage)) { + tcx.sess.mark_attr_used(attr); + no_coverage_feature_enabled = true; + } + } + } else if tcx.sess.check_name(attr, sym::no_coverage) { + no_coverage_attr = Some(attr); } else if tcx.sess.check_name(attr, sym::rustc_std_internal_symbol) { codegen_fn_attrs.flags |= CodegenFnAttrFlags::RUSTC_STD_INTERNAL_SYMBOL; } else if tcx.sess.check_name(attr, sym::used) { @@ -2934,6 +2945,23 @@ fn codegen_fn_attrs(tcx: TyCtxt<'_>, id: DefId) -> CodegenFnAttrs { } } + if let Some(no_coverage_attr) = no_coverage_attr { + if tcx.sess.features_untracked().no_coverage || no_coverage_feature_enabled { + codegen_fn_attrs.flags |= CodegenFnAttrFlags::NO_COVERAGE + } else { + let mut err = feature_err( + &tcx.sess.parse_sess, + sym::no_coverage, + no_coverage_attr.span, + "the `#[no_coverage]` attribute is an experimental feature", + ); + if tcx.sess.parse_sess.unstable_features.is_nightly_build() { + err.help("or, alternatively, add `#[feature(no_coverage)]` to the function"); + } + err.emit(); + } + } + codegen_fn_attrs.inline = attrs.iter().fold(InlineAttr::None, |ia, attr| { if !attr.has_name(sym::inline) { return ia; diff --git a/library/core/src/cmp.rs b/library/core/src/cmp.rs index cdb6006b1b3..0a3e5789e8b 100644 --- a/library/core/src/cmp.rs +++ b/library/core/src/cmp.rs @@ -274,6 +274,8 @@ pub trait Eq: PartialEq { // // This should never be implemented by hand. #[doc(hidden)] + #[cfg_attr(not(bootstrap), feature(no_coverage))] + #[cfg_attr(not(bootstrap), no_coverage)] #[inline] #[stable(feature = "rust1", since = "1.0.0")] fn assert_receiver_is_total_eq(&self) {} diff --git a/src/test/run-make-fulldeps/coverage-reports/expected_show_coverage.issue-83601.txt b/src/test/run-make-fulldeps/coverage-reports/expected_show_coverage.issue-83601.txt new file mode 100644 index 00000000000..46f3add9427 --- /dev/null +++ b/src/test/run-make-fulldeps/coverage-reports/expected_show_coverage.issue-83601.txt @@ -0,0 +1,22 @@ + 1| |// Shows that rust-lang/rust/83601 is resolved + 2| | + 3| 3|#[derive(Debug, PartialEq, Eq)] + ^2 + ------------------ + | ::eq: + | 3| 2|#[derive(Debug, PartialEq, Eq)] + ------------------ + | Unexecuted instantiation: ::ne + ------------------ + 4| |struct Foo(u32); + 5| | + 6| 1|fn main() { + 7| 1| let bar = Foo(1); + 8| 0| assert_eq!(bar, Foo(1)); + 9| 1| let baz = Foo(0); + 10| 0| assert_ne!(baz, Foo(1)); + 11| 1| println!("{:?}", Foo(1)); + 12| 1| println!("{:?}", bar); + 13| 1| println!("{:?}", baz); + 14| 1|} + diff --git a/src/test/run-make-fulldeps/coverage-reports/expected_show_coverage.no_cov_crate.txt b/src/test/run-make-fulldeps/coverage-reports/expected_show_coverage.no_cov_crate.txt new file mode 100644 index 00000000000..c4a7b0cc7e9 --- /dev/null +++ b/src/test/run-make-fulldeps/coverage-reports/expected_show_coverage.no_cov_crate.txt @@ -0,0 +1,18 @@ + 1| |// Enables `no_coverage` on the entire crate + 2| |#![feature(no_coverage)] + 3| | + 4| |#[no_coverage] + 5| |fn do_not_add_coverage_1() { + 6| | println!("called but not covered"); + 7| |} + 8| | + 9| |#[no_coverage] + 10| |fn do_not_add_coverage_2() { + 11| | println!("called but not covered"); + 12| |} + 13| | + 14| 1|fn main() { + 15| 1| do_not_add_coverage_1(); + 16| 1| do_not_add_coverage_2(); + 17| 1|} + diff --git a/src/test/run-make-fulldeps/coverage-reports/expected_show_coverage.no_cov_func.txt b/src/test/run-make-fulldeps/coverage-reports/expected_show_coverage.no_cov_func.txt new file mode 100644 index 00000000000..16eaf7c858c --- /dev/null +++ b/src/test/run-make-fulldeps/coverage-reports/expected_show_coverage.no_cov_func.txt @@ -0,0 +1,19 @@ + 1| |// Enables `no_coverage` on individual functions + 2| | + 3| |#[feature(no_coverage)] + 4| |#[no_coverage] + 5| |fn do_not_add_coverage_1() { + 6| | println!("called but not covered"); + 7| |} + 8| | + 9| |#[no_coverage] + 10| |#[feature(no_coverage)] + 11| |fn do_not_add_coverage_2() { + 12| | println!("called but not covered"); + 13| |} + 14| | + 15| 1|fn main() { + 16| 1| do_not_add_coverage_1(); + 17| 1| do_not_add_coverage_2(); + 18| 1|} + diff --git a/src/test/run-make-fulldeps/coverage-reports/expected_show_coverage.partial_eq.txt b/src/test/run-make-fulldeps/coverage-reports/expected_show_coverage.partial_eq.txt index 4e4dde46b34..fc266653349 100644 --- a/src/test/run-make-fulldeps/coverage-reports/expected_show_coverage.partial_eq.txt +++ b/src/test/run-make-fulldeps/coverage-reports/expected_show_coverage.partial_eq.txt @@ -2,7 +2,7 @@ 2| |// structure of this test. 3| | 4| 2|#[derive(Clone, Debug, PartialEq, Eq, PartialOrd, Ord)] - ^0 ^0 ^0 ^0 ^1 ^1 ^0^0 + ^0 ^0 ^0 ^1 ^1 ^0^0 ------------------ | Unexecuted instantiation: ::ne ------------------ diff --git a/src/test/run-make-fulldeps/coverage/issue-83601.rs b/src/test/run-make-fulldeps/coverage/issue-83601.rs new file mode 100644 index 00000000000..0b72a81947c --- /dev/null +++ b/src/test/run-make-fulldeps/coverage/issue-83601.rs @@ -0,0 +1,14 @@ +// Shows that rust-lang/rust/83601 is resolved + +#[derive(Debug, PartialEq, Eq)] +struct Foo(u32); + +fn main() { + let bar = Foo(1); + assert_eq!(bar, Foo(1)); + let baz = Foo(0); + assert_ne!(baz, Foo(1)); + println!("{:?}", Foo(1)); + println!("{:?}", bar); + println!("{:?}", baz); +} diff --git a/src/test/run-make-fulldeps/coverage/no_cov_crate.rs b/src/test/run-make-fulldeps/coverage/no_cov_crate.rs new file mode 100644 index 00000000000..300570db7e8 --- /dev/null +++ b/src/test/run-make-fulldeps/coverage/no_cov_crate.rs @@ -0,0 +1,17 @@ +// Enables `no_coverage` on the entire crate +#![feature(no_coverage)] + +#[no_coverage] +fn do_not_add_coverage_1() { + println!("called but not covered"); +} + +#[no_coverage] +fn do_not_add_coverage_2() { + println!("called but not covered"); +} + +fn main() { + do_not_add_coverage_1(); + do_not_add_coverage_2(); +} diff --git a/src/test/run-make-fulldeps/coverage/no_cov_func.rs b/src/test/run-make-fulldeps/coverage/no_cov_func.rs new file mode 100644 index 00000000000..e19a2c4a872 --- /dev/null +++ b/src/test/run-make-fulldeps/coverage/no_cov_func.rs @@ -0,0 +1,18 @@ +// Enables `no_coverage` on individual functions + +#[feature(no_coverage)] +#[no_coverage] +fn do_not_add_coverage_1() { + println!("called but not covered"); +} + +#[no_coverage] +#[feature(no_coverage)] +fn do_not_add_coverage_2() { + println!("called but not covered"); +} + +fn main() { + do_not_add_coverage_1(); + do_not_add_coverage_2(); +} diff --git a/src/test/ui/feature-gates/feature-gate-no_coverage.rs b/src/test/ui/feature-gates/feature-gate-no_coverage.rs new file mode 100644 index 00000000000..c6b79f9a431 --- /dev/null +++ b/src/test/ui/feature-gates/feature-gate-no_coverage.rs @@ -0,0 +1,8 @@ +#![crate_type = "lib"] + +#[no_coverage] +#[feature(no_coverage)] // does not have to be enabled before `#[no_coverage]` +fn no_coverage_is_enabled_on_this_function() {} + +#[no_coverage] //~ ERROR the `#[no_coverage]` attribute is an experimental feature +fn requires_feature_no_coverage() {} diff --git a/src/test/ui/feature-gates/feature-gate-no_coverage.stderr b/src/test/ui/feature-gates/feature-gate-no_coverage.stderr new file mode 100644 index 00000000000..04627be4aaf --- /dev/null +++ b/src/test/ui/feature-gates/feature-gate-no_coverage.stderr @@ -0,0 +1,13 @@ +error[E0658]: the `#[no_coverage]` attribute is an experimental feature + --> $DIR/feature-gate-no_coverage.rs:7:1 + | +LL | #[no_coverage] + | ^^^^^^^^^^^^^^ + | + = note: see issue #84605 for more information + = help: add `#![feature(no_coverage)]` to the crate attributes to enable + = help: or, alternatively, add `#[feature(no_coverage)]` to the function + +error: aborting due to previous error + +For more information about this error, try `rustc --explain E0658`.