diff --git a/compiler/rustc_codegen_llvm/src/coverageinfo/mod.rs b/compiler/rustc_codegen_llvm/src/coverageinfo/mod.rs index 133084b7c12ae..54f4bc0634021 100644 --- a/compiler/rustc_codegen_llvm/src/coverageinfo/mod.rs +++ b/compiler/rustc_codegen_llvm/src/coverageinfo/mod.rs @@ -85,14 +85,6 @@ impl<'tcx> CoverageInfoBuilderMethods<'tcx> for Builder<'_, '_, 'tcx> { let bx = self; - match coverage.kind { - // Marker statements have no effect during codegen, - // so return early and don't create `func_coverage`. - CoverageKind::SpanMarker | CoverageKind::BlockMarker { .. } => return, - // Match exhaustively to ensure that newly-added kinds are classified correctly. - CoverageKind::CounterIncrement { .. } | CoverageKind::ExpressionUsed { .. } => {} - } - let Some(function_coverage_info) = bx.tcx.instance_mir(instance.def).function_coverage_info.as_deref() else { @@ -109,7 +101,7 @@ impl<'tcx> CoverageInfoBuilderMethods<'tcx> for Builder<'_, '_, 'tcx> { let Coverage { kind } = coverage; match *kind { CoverageKind::SpanMarker | CoverageKind::BlockMarker { .. } => unreachable!( - "unexpected marker statement {kind:?} should have caused an early return" + "marker statement {kind:?} should have been removed by CleanupPostBorrowck" ), CoverageKind::CounterIncrement { id } => { func_coverage.mark_counter_id_seen(id); diff --git a/compiler/rustc_middle/src/mir/coverage.rs b/compiler/rustc_middle/src/mir/coverage.rs index 645a417c32250..588aa1f40d79c 100644 --- a/compiler/rustc_middle/src/mir/coverage.rs +++ b/compiler/rustc_middle/src/mir/coverage.rs @@ -88,14 +88,13 @@ pub enum CoverageKind { /// Marks a span that might otherwise not be represented in MIR, so that /// coverage instrumentation can associate it with its enclosing block/BCB. /// - /// Only used by the `InstrumentCoverage` pass, and has no effect during - /// codegen. + /// Should be erased before codegen (at some point after `InstrumentCoverage`). SpanMarker, /// Marks its enclosing basic block with an ID that can be referred to by /// side data in [`BranchInfo`]. /// - /// Has no effect during codegen. + /// Should be erased before codegen (at some point after `InstrumentCoverage`). BlockMarker { id: BlockMarkerId }, /// Marks the point in MIR control flow represented by a coverage counter. diff --git a/compiler/rustc_mir_transform/src/cleanup_post_borrowck.rs b/compiler/rustc_mir_transform/src/cleanup_post_borrowck.rs index 5b4bc4fa13424..aaf2035fc2103 100644 --- a/compiler/rustc_mir_transform/src/cleanup_post_borrowck.rs +++ b/compiler/rustc_mir_transform/src/cleanup_post_borrowck.rs @@ -5,15 +5,20 @@ //! - [`AscribeUserType`] //! - [`FakeRead`] //! - [`Assign`] statements with a [`Fake`] borrow +//! - [`Coverage`] statements of kind [`BlockMarker`] or [`SpanMarker`] //! //! [`AscribeUserType`]: rustc_middle::mir::StatementKind::AscribeUserType //! [`Assign`]: rustc_middle::mir::StatementKind::Assign //! [`FakeRead`]: rustc_middle::mir::StatementKind::FakeRead //! [`Nop`]: rustc_middle::mir::StatementKind::Nop //! [`Fake`]: rustc_middle::mir::BorrowKind::Fake +//! [`Coverage`]: rustc_middle::mir::StatementKind::Coverage +//! [`BlockMarker`]: rustc_middle::mir::coverage::CoverageKind::BlockMarker +//! [`SpanMarker`]: rustc_middle::mir::coverage::CoverageKind::SpanMarker use crate::MirPass; -use rustc_middle::mir::{Body, BorrowKind, Rvalue, StatementKind, TerminatorKind}; +use rustc_middle::mir::coverage::CoverageKind; +use rustc_middle::mir::{Body, BorrowKind, Coverage, Rvalue, StatementKind, TerminatorKind}; use rustc_middle::ty::TyCtxt; pub struct CleanupPostBorrowck; @@ -25,6 +30,12 @@ impl<'tcx> MirPass<'tcx> for CleanupPostBorrowck { match statement.kind { StatementKind::AscribeUserType(..) | StatementKind::Assign(box (_, Rvalue::Ref(_, BorrowKind::Fake, _))) + | StatementKind::Coverage(box Coverage { + // These kinds of coverage statements are markers inserted during + // MIR building, and are not needed after InstrumentCoverage. + kind: CoverageKind::BlockMarker { .. } | CoverageKind::SpanMarker { .. }, + .. + }) | StatementKind::FakeRead(..) => statement.make_nop(), _ => (), } diff --git a/tests/mir-opt/instrument_coverage_cleanup.main.CleanupPostBorrowck.diff b/tests/mir-opt/instrument_coverage_cleanup.main.CleanupPostBorrowck.diff new file mode 100644 index 0000000000000..ff65ca7703928 --- /dev/null +++ b/tests/mir-opt/instrument_coverage_cleanup.main.CleanupPostBorrowck.diff @@ -0,0 +1,56 @@ +- // MIR for `main` before CleanupPostBorrowck ++ // MIR for `main` after CleanupPostBorrowck + + fn main() -> () { + let mut _0: (); + let mut _1: bool; + + coverage branch { true: BlockMarkerId(0), false: BlockMarkerId(1) } => /the/src/instrument_coverage_cleanup.rs:15:8: 15:36 (#0) + + coverage ExpressionId(0) => Expression { lhs: Counter(0), op: Subtract, rhs: Counter(1) }; + coverage ExpressionId(1) => Expression { lhs: Counter(1), op: Add, rhs: Expression(0) }; + coverage Code(Counter(0)) => /the/src/instrument_coverage_cleanup.rs:14:1 - 15:36; + coverage Code(Expression(0)) => /the/src/instrument_coverage_cleanup.rs:15:37 - 15:39; + coverage Code(Counter(1)) => /the/src/instrument_coverage_cleanup.rs:15:39 - 15:40; + coverage Code(Expression(1)) => /the/src/instrument_coverage_cleanup.rs:16:1 - 16:2; + coverage Branch { true_term: Expression(0), false_term: Counter(1) } => /the/src/instrument_coverage_cleanup.rs:15:8 - 15:36; + + bb0: { + Coverage::CounterIncrement(0); +- Coverage::SpanMarker; ++ nop; + StorageLive(_1); + _1 = std::hint::black_box::(const true) -> [return: bb1, unwind: bb5]; + } + + bb1: { + switchInt(move _1) -> [0: bb3, otherwise: bb2]; + } + + bb2: { + Coverage::CounterIncrement(1); +- Coverage::BlockMarker(1); ++ nop; + _0 = const (); + goto -> bb4; + } + + bb3: { + Coverage::ExpressionUsed(0); +- Coverage::BlockMarker(0); ++ nop; + _0 = const (); + goto -> bb4; + } + + bb4: { + Coverage::ExpressionUsed(1); + StorageDead(_1); + return; + } + + bb5 (cleanup): { + resume; + } + } + diff --git a/tests/mir-opt/instrument_coverage_cleanup.main.InstrumentCoverage.diff b/tests/mir-opt/instrument_coverage_cleanup.main.InstrumentCoverage.diff new file mode 100644 index 0000000000000..8757559149a43 --- /dev/null +++ b/tests/mir-opt/instrument_coverage_cleanup.main.InstrumentCoverage.diff @@ -0,0 +1,53 @@ +- // MIR for `main` before InstrumentCoverage ++ // MIR for `main` after InstrumentCoverage + + fn main() -> () { + let mut _0: (); + let mut _1: bool; + + coverage branch { true: BlockMarkerId(0), false: BlockMarkerId(1) } => /the/src/instrument_coverage_cleanup.rs:15:8: 15:36 (#0) + ++ coverage ExpressionId(0) => Expression { lhs: Counter(0), op: Subtract, rhs: Counter(1) }; ++ coverage ExpressionId(1) => Expression { lhs: Counter(1), op: Add, rhs: Expression(0) }; ++ coverage Code(Counter(0)) => /the/src/instrument_coverage_cleanup.rs:14:1 - 15:36; ++ coverage Code(Expression(0)) => /the/src/instrument_coverage_cleanup.rs:15:37 - 15:39; ++ coverage Code(Counter(1)) => /the/src/instrument_coverage_cleanup.rs:15:39 - 15:40; ++ coverage Code(Expression(1)) => /the/src/instrument_coverage_cleanup.rs:16:1 - 16:2; ++ coverage Branch { true_term: Expression(0), false_term: Counter(1) } => /the/src/instrument_coverage_cleanup.rs:15:8 - 15:36; ++ + bb0: { ++ Coverage::CounterIncrement(0); + Coverage::SpanMarker; + StorageLive(_1); + _1 = std::hint::black_box::(const true) -> [return: bb1, unwind: bb5]; + } + + bb1: { + switchInt(move _1) -> [0: bb3, otherwise: bb2]; + } + + bb2: { ++ Coverage::CounterIncrement(1); + Coverage::BlockMarker(1); + _0 = const (); + goto -> bb4; + } + + bb3: { ++ Coverage::ExpressionUsed(0); + Coverage::BlockMarker(0); + _0 = const (); + goto -> bb4; + } + + bb4: { ++ Coverage::ExpressionUsed(1); + StorageDead(_1); + return; + } + + bb5 (cleanup): { + resume; + } + } + diff --git a/tests/mir-opt/instrument_coverage_cleanup.rs b/tests/mir-opt/instrument_coverage_cleanup.rs new file mode 100644 index 0000000000000..8a2fd67139bd9 --- /dev/null +++ b/tests/mir-opt/instrument_coverage_cleanup.rs @@ -0,0 +1,22 @@ +// Test that CleanupPostBorrowck cleans up the marker statements that are +// inserted during MIR building (after InstrumentCoverage is done with them), +// but leaves the statements that were added by InstrumentCoverage. +// +// Removed statement kinds: BlockMarker, SpanMarker +// Retained statement kinds: CounterIncrement, ExpressionUsed + +//@ unit-test: InstrumentCoverage +//@ compile-flags: -Cinstrument-coverage -Zcoverage-options=branch -Zno-profiler-runtime +//@ compile-flags: --remap-path-prefix={{src-base}}=/the/src + +// EMIT_MIR instrument_coverage_cleanup.main.InstrumentCoverage.diff +// EMIT_MIR instrument_coverage_cleanup.main.CleanupPostBorrowck.diff +fn main() { + if !core::hint::black_box(true) {} +} + +// CHECK-NOT: Coverage::BlockMarker +// CHECK-NOT: Coverage::SpanMarker +// CHECK: Coverage::CounterIncrement +// CHECK-NOT: Coverage::BlockMarker +// CHECK-NOT: Coverage::SpanMarker