diff --git a/compiler/rustc_mir_transform/src/coverage/spans.rs b/compiler/rustc_mir_transform/src/coverage/spans.rs index 576f098e6e4aa..f346aa1810c9d 100644 --- a/compiler/rustc_mir_transform/src/coverage/spans.rs +++ b/compiler/rustc_mir_transform/src/coverage/spans.rs @@ -220,7 +220,6 @@ impl<'a> CoverageSpansGenerator<'a> { // span-processing steps don't make sense yet. if self.some_prev.is_none() { debug!(" initial span"); - self.maybe_push_macro_name_span(); continue; } @@ -232,7 +231,6 @@ impl<'a> CoverageSpansGenerator<'a> { debug!(" same bcb (and neither is a closure), merge with prev={prev:?}"); let prev = self.take_prev(); self.curr_mut().merge_from(&prev); - self.maybe_push_macro_name_span(); // Note that curr.span may now differ from curr_original_span } else if prev.span.hi() <= curr.span.lo() { debug!( @@ -240,7 +238,6 @@ impl<'a> CoverageSpansGenerator<'a> { ); let prev = self.take_prev(); self.refined_spans.push(prev); - self.maybe_push_macro_name_span(); } else if prev.is_closure { // drop any equal or overlapping span (`curr`) and keep `prev` to test again in the // next iter @@ -256,7 +253,6 @@ impl<'a> CoverageSpansGenerator<'a> { self.update_pending_dups(); } else { self.cutoff_prev_at_overlapping_curr(); - self.maybe_push_macro_name_span(); } } @@ -291,36 +287,6 @@ impl<'a> CoverageSpansGenerator<'a> { self.refined_spans } - /// If `curr` is part of a new macro expansion, carve out and push a separate - /// span that ends just after the macro name and its subsequent `!`. - fn maybe_push_macro_name_span(&mut self) { - let curr = self.curr(); - - let Some(visible_macro) = curr.visible_macro else { return }; - - // The split point is relative to `curr_original_span`, - // because `curr.span` may have been merged with preceding spans. - let split_point_after_macro_bang = self.curr_original_span.lo() - + BytePos(visible_macro.as_str().len() as u32) - + BytePos(1); // add 1 for the `!` - debug_assert!(split_point_after_macro_bang <= curr.span.hi()); - if split_point_after_macro_bang > curr.span.hi() { - // Something is wrong with the macro name span; - // return now to avoid emitting malformed mappings (e.g. #117788). - return; - } - - let mut macro_name_cov = curr.clone(); - macro_name_cov.span = macro_name_cov.span.with_hi(split_point_after_macro_bang); - self.curr_mut().span = curr.span.with_lo(split_point_after_macro_bang); - - debug!( - " and curr starts a new macro expansion, so add a new span just for \ - the macro `{visible_macro}!`, new span={macro_name_cov:?}", - ); - self.refined_spans.push(macro_name_cov); - } - #[track_caller] fn curr(&self) -> &CoverageSpan { self.some_curr.as_ref().unwrap_or_else(|| bug!("some_curr is None (curr)")) diff --git a/compiler/rustc_mir_transform/src/coverage/spans/from_mir.rs b/compiler/rustc_mir_transform/src/coverage/spans/from_mir.rs index b28abcf71d57e..637424753d96c 100644 --- a/compiler/rustc_mir_transform/src/coverage/spans/from_mir.rs +++ b/compiler/rustc_mir_transform/src/coverage/spans/from_mir.rs @@ -38,6 +38,7 @@ pub(super) fn mir_to_initial_sorted_coverage_spans( initial_spans.sort_by(|a, b| basic_coverage_blocks.cmp_in_dominator_order(a.bcb, b.bcb)); remove_unwanted_macro_spans(&mut initial_spans); + split_visible_macro_spans(&mut initial_spans); initial_spans.sort_by(|a, b| { // First sort by span start. @@ -79,6 +80,41 @@ fn remove_unwanted_macro_spans(initial_spans: &mut Vec) { }); } +/// When a span corresponds to a macro invocation that is visible from the +/// function body, split it into two parts. The first part covers just the +/// macro name plus `!`, and the second part covers the rest of the macro +/// invocation. This seems to give better results for code that uses macros. +fn split_visible_macro_spans(initial_spans: &mut Vec) { + let mut extra_spans = vec![]; + + initial_spans.retain(|covspan| { + if covspan.is_closure { + return true; + } + + let Some(visible_macro) = covspan.visible_macro else { return true }; + + let split_len = visible_macro.as_str().len() as u32 + 1; + let (before, after) = covspan.span.split_at(split_len); + if !covspan.span.contains(before) || !covspan.span.contains(after) { + // Something is unexpectedly wrong with the split point. + // The debug assertion in `split_at` will have already caught this, + // but in release builds it's safer to do nothing and maybe get a + // bug report for unexpected coverage, rather than risk an ICE. + return true; + } + + assert!(!covspan.is_closure); + extra_spans.push(CoverageSpan::new(before, covspan.visible_macro, covspan.bcb, false)); + extra_spans.push(CoverageSpan::new(after, covspan.visible_macro, covspan.bcb, false)); + false // Discard the original covspan that we just split. + }); + + // The newly-split spans are added at the end, so any previous sorting + // is not preserved. + initial_spans.extend(extra_spans); +} + // Generate a set of `CoverageSpan`s from the filtered set of `Statement`s and `Terminator`s of // the `BasicBlock`(s) in the given `BasicCoverageBlockData`. One `CoverageSpan` is generated // for each `Statement` and `Terminator`. (Note that subsequent stages of coverage analysis will diff --git a/tests/coverage/closure.cov-map b/tests/coverage/closure.cov-map index 522c1e73afe3d..c5ac17600cd2a 100644 --- a/tests/coverage/closure.cov-map +++ b/tests/coverage/closure.cov-map @@ -81,21 +81,18 @@ Number of file 0 mappings: 1 - Code(Zero) at (prev + 171, 13) to (start + 2, 14) Function name: closure::main::{closure#14} -Raw bytes (36): 0x[01, 01, 03, 05, 0a, 01, 05, 01, 05, 05, 03, b2, 01, 0d, 00, 15, 01, 01, 11, 01, 1b, 05, 01, 1e, 00, 25, 0a, 00, 2f, 00, 33, 03, 01, 0d, 00, 0e] +Raw bytes (29): 0x[01, 01, 02, 01, 05, 05, 02, 04, 01, b2, 01, 0d, 02, 1b, 05, 02, 1e, 00, 25, 02, 00, 2f, 00, 33, 07, 01, 0d, 00, 0e] Number of files: 1 - file 0 => global file 1 -Number of expressions: 3 -- expression 0 operands: lhs = Counter(1), rhs = Expression(2, Sub) -- expression 1 operands: lhs = Counter(0), rhs = Counter(1) -- expression 2 operands: lhs = Counter(0), rhs = Counter(1) -Number of file 0 mappings: 5 -- Code(Expression(0, Add)) at (prev + 178, 13) to (start + 0, 21) - = (c1 + (c0 - c1)) -- Code(Counter(0)) at (prev + 1, 17) to (start + 1, 27) -- Code(Counter(1)) at (prev + 1, 30) to (start + 0, 37) -- Code(Expression(2, Sub)) at (prev + 0, 47) to (start + 0, 51) +Number of expressions: 2 +- expression 0 operands: lhs = Counter(0), rhs = Counter(1) +- expression 1 operands: lhs = Counter(1), rhs = Expression(0, Sub) +Number of file 0 mappings: 4 +- Code(Counter(0)) at (prev + 178, 13) to (start + 2, 27) +- Code(Counter(1)) at (prev + 2, 30) to (start + 0, 37) +- Code(Expression(0, Sub)) at (prev + 0, 47) to (start + 0, 51) = (c0 - c1) -- Code(Expression(0, Add)) at (prev + 1, 13) to (start + 0, 14) +- Code(Expression(1, Add)) at (prev + 1, 13) to (start + 0, 14) = (c1 + (c0 - c1)) Function name: closure::main::{closure#15} @@ -118,21 +115,18 @@ Number of file 0 mappings: 6 = (c1 + (c0 - c1)) Function name: closure::main::{closure#16} -Raw bytes (36): 0x[01, 01, 03, 05, 0a, 01, 05, 01, 05, 05, 03, c4, 01, 0d, 00, 15, 01, 01, 11, 01, 1b, 05, 01, 1e, 00, 25, 0a, 00, 2f, 00, 33, 03, 01, 0d, 00, 0e] +Raw bytes (29): 0x[01, 01, 02, 01, 05, 05, 02, 04, 01, c4, 01, 0d, 02, 1b, 05, 02, 1e, 00, 25, 02, 00, 2f, 00, 33, 07, 01, 0d, 00, 0e] Number of files: 1 - file 0 => global file 1 -Number of expressions: 3 -- expression 0 operands: lhs = Counter(1), rhs = Expression(2, Sub) -- expression 1 operands: lhs = Counter(0), rhs = Counter(1) -- expression 2 operands: lhs = Counter(0), rhs = Counter(1) -Number of file 0 mappings: 5 -- Code(Expression(0, Add)) at (prev + 196, 13) to (start + 0, 21) - = (c1 + (c0 - c1)) -- Code(Counter(0)) at (prev + 1, 17) to (start + 1, 27) -- Code(Counter(1)) at (prev + 1, 30) to (start + 0, 37) -- Code(Expression(2, Sub)) at (prev + 0, 47) to (start + 0, 51) +Number of expressions: 2 +- expression 0 operands: lhs = Counter(0), rhs = Counter(1) +- expression 1 operands: lhs = Counter(1), rhs = Expression(0, Sub) +Number of file 0 mappings: 4 +- Code(Counter(0)) at (prev + 196, 13) to (start + 2, 27) +- Code(Counter(1)) at (prev + 2, 30) to (start + 0, 37) +- Code(Expression(0, Sub)) at (prev + 0, 47) to (start + 0, 51) = (c0 - c1) -- Code(Expression(0, Add)) at (prev + 1, 13) to (start + 0, 14) +- Code(Expression(1, Add)) at (prev + 1, 13) to (start + 0, 14) = (c1 + (c0 - c1)) Function name: closure::main::{closure#17}