diff options
Diffstat (limited to 'compiler/rustc_mir_transform/src/coverage/counters.rs')
| -rw-r--r-- | compiler/rustc_mir_transform/src/coverage/counters.rs | 190 |
1 files changed, 57 insertions, 133 deletions
diff --git a/compiler/rustc_mir_transform/src/coverage/counters.rs b/compiler/rustc_mir_transform/src/coverage/counters.rs index d07f59bc72a..b34ec95b4e8 100644 --- a/compiler/rustc_mir_transform/src/coverage/counters.rs +++ b/compiler/rustc_mir_transform/src/coverage/counters.rs @@ -1,5 +1,3 @@ -use super::Error; - use super::graph; use graph::{BasicCoverageBlock, BcbBranch, CoverageGraph, TraverseCoverageGraphWithLoops}; @@ -12,8 +10,6 @@ use rustc_middle::mir::coverage::*; use std::fmt::{self, Debug}; -const NESTED_INDENT: &str = " "; - /// The coverage counter or counter expression associated with a particular /// BCB node or BCB edge. #[derive(Clone)] @@ -55,7 +51,7 @@ pub(super) struct CoverageCounters { /// edge between two BCBs. bcb_edge_counters: FxHashMap<(BasicCoverageBlock, BasicCoverageBlock), BcbCounter>, /// Tracks which BCBs have a counter associated with some incoming edge. - /// Only used by debug assertions, to verify that BCBs with incoming edge + /// Only used by assertions, to verify that BCBs with incoming edge /// counters do not have their own physical counters (expressions are allowed). bcb_has_incoming_edge_counters: BitSet<BasicCoverageBlock>, /// Table of expression data, associating each expression ID with its @@ -83,7 +79,7 @@ impl CoverageCounters { &mut self, basic_coverage_blocks: &CoverageGraph, bcb_has_coverage_spans: impl Fn(BasicCoverageBlock) -> bool, - ) -> Result<(), Error> { + ) { MakeBcbCounters::new(self, basic_coverage_blocks).make_bcb_counters(bcb_has_coverage_spans) } @@ -113,26 +109,23 @@ impl CoverageCounters { self.expressions.len() } - fn set_bcb_counter( - &mut self, - bcb: BasicCoverageBlock, - counter_kind: BcbCounter, - ) -> Result<CovTerm, Error> { - debug_assert!( + fn set_bcb_counter(&mut self, bcb: BasicCoverageBlock, counter_kind: BcbCounter) -> CovTerm { + assert!( // If the BCB has an edge counter (to be injected into a new `BasicBlock`), it can also // have an expression (to be injected into an existing `BasicBlock` represented by this // `BasicCoverageBlock`). counter_kind.is_expression() || !self.bcb_has_incoming_edge_counters.contains(bcb), "attempt to add a `Counter` to a BCB target with existing incoming edge counters" ); + let term = counter_kind.as_term(); if let Some(replaced) = self.bcb_counters[bcb].replace(counter_kind) { - Error::from_string(format!( + bug!( "attempt to set a BasicCoverageBlock coverage counter more than once; \ {bcb:?} already had counter {replaced:?}", - )) + ); } else { - Ok(term) + term } } @@ -141,27 +134,26 @@ impl CoverageCounters { from_bcb: BasicCoverageBlock, to_bcb: BasicCoverageBlock, counter_kind: BcbCounter, - ) -> Result<CovTerm, Error> { - if level_enabled!(tracing::Level::DEBUG) { - // If the BCB has an edge counter (to be injected into a new `BasicBlock`), it can also - // have an expression (to be injected into an existing `BasicBlock` represented by this - // `BasicCoverageBlock`). - if self.bcb_counter(to_bcb).is_some_and(|c| !c.is_expression()) { - return Error::from_string(format!( - "attempt to add an incoming edge counter from {from_bcb:?} when the target BCB already \ - has a `Counter`" - )); - } + ) -> CovTerm { + // If the BCB has an edge counter (to be injected into a new `BasicBlock`), it can also + // have an expression (to be injected into an existing `BasicBlock` represented by this + // `BasicCoverageBlock`). + if let Some(node_counter) = self.bcb_counter(to_bcb) && !node_counter.is_expression() { + bug!( + "attempt to add an incoming edge counter from {from_bcb:?} \ + when the target BCB already has {node_counter:?}" + ); } + self.bcb_has_incoming_edge_counters.insert(to_bcb); let term = counter_kind.as_term(); if let Some(replaced) = self.bcb_edge_counters.insert((from_bcb, to_bcb), counter_kind) { - Error::from_string(format!( + bug!( "attempt to set an edge counter more than once; from_bcb: \ {from_bcb:?} already had counter {replaced:?}", - )) + ); } else { - Ok(term) + term } } @@ -215,14 +207,7 @@ impl<'a> MakeBcbCounters<'a> { /// One way to predict which branch executes the least is by considering loops. A loop is exited /// at a branch, so the branch that jumps to a `BasicCoverageBlock` outside the loop is almost /// always executed less than the branch that does not exit the loop. - /// - /// Returns any non-code-span expressions created to represent intermediate values (such as to - /// add two counters so the result can be subtracted from another counter), or an Error with - /// message for subsequent debugging. - fn make_bcb_counters( - &mut self, - bcb_has_coverage_spans: impl Fn(BasicCoverageBlock) -> bool, - ) -> Result<(), Error> { + fn make_bcb_counters(&mut self, bcb_has_coverage_spans: impl Fn(BasicCoverageBlock) -> bool) { debug!("make_bcb_counters(): adding a counter or expression to each BasicCoverageBlock"); // Walk the `CoverageGraph`. For each `BasicCoverageBlock` node with an associated @@ -239,10 +224,10 @@ impl<'a> MakeBcbCounters<'a> { while let Some(bcb) = traversal.next() { if bcb_has_coverage_spans(bcb) { debug!("{:?} has at least one coverage span. Get or make its counter", bcb); - let branching_counter_operand = self.get_or_make_counter_operand(bcb)?; + let branching_counter_operand = self.get_or_make_counter_operand(bcb); if self.bcb_needs_branch_counters(bcb) { - self.make_branch_counters(&traversal, bcb, branching_counter_operand)?; + self.make_branch_counters(&traversal, bcb, branching_counter_operand); } } else { debug!( @@ -253,14 +238,11 @@ impl<'a> MakeBcbCounters<'a> { } } - if traversal.is_complete() { - Ok(()) - } else { - Error::from_string(format!( - "`TraverseCoverageGraphWithLoops` missed some `BasicCoverageBlock`s: {:?}", - traversal.unvisited(), - )) - } + assert!( + traversal.is_complete(), + "`TraverseCoverageGraphWithLoops` missed some `BasicCoverageBlock`s: {:?}", + traversal.unvisited(), + ); } fn make_branch_counters( @@ -268,7 +250,7 @@ impl<'a> MakeBcbCounters<'a> { traversal: &TraverseCoverageGraphWithLoops<'_>, branching_bcb: BasicCoverageBlock, branching_counter_operand: CovTerm, - ) -> Result<(), Error> { + ) { let branches = self.bcb_branches(branching_bcb); debug!( "{:?} has some branch(es) without counters:\n {}", @@ -301,10 +283,10 @@ impl<'a> MakeBcbCounters<'a> { counter", branch, branching_bcb ); - self.get_or_make_counter_operand(branch.target_bcb)? + self.get_or_make_counter_operand(branch.target_bcb) } else { debug!(" {:?} has multiple incoming edges, so adding an edge counter", branch); - self.get_or_make_edge_counter_operand(branching_bcb, branch.target_bcb)? + self.get_or_make_edge_counter_operand(branching_bcb, branch.target_bcb) }; if let Some(sumup_counter_operand) = some_sumup_counter_operand.replace(branch_counter_operand) @@ -339,31 +321,18 @@ impl<'a> MakeBcbCounters<'a> { debug!("{:?} gets an expression: {:?}", expression_branch, expression); let bcb = expression_branch.target_bcb; if expression_branch.is_only_path_to_target() { - self.coverage_counters.set_bcb_counter(bcb, expression)?; + self.coverage_counters.set_bcb_counter(bcb, expression); } else { - self.coverage_counters.set_bcb_edge_counter(branching_bcb, bcb, expression)?; + self.coverage_counters.set_bcb_edge_counter(branching_bcb, bcb, expression); } - Ok(()) - } - - fn get_or_make_counter_operand(&mut self, bcb: BasicCoverageBlock) -> Result<CovTerm, Error> { - self.recursive_get_or_make_counter_operand(bcb, 1) } - fn recursive_get_or_make_counter_operand( - &mut self, - bcb: BasicCoverageBlock, - debug_indent_level: usize, - ) -> Result<CovTerm, Error> { + #[instrument(level = "debug", skip(self))] + fn get_or_make_counter_operand(&mut self, bcb: BasicCoverageBlock) -> CovTerm { // If the BCB already has a counter, return it. if let Some(counter_kind) = &self.coverage_counters.bcb_counters[bcb] { - debug!( - "{}{:?} already has a counter: {:?}", - NESTED_INDENT.repeat(debug_indent_level), - bcb, - counter_kind, - ); - return Ok(counter_kind.as_term()); + debug!("{bcb:?} already has a counter: {counter_kind:?}"); + return counter_kind.as_term(); } // A BCB with only one incoming edge gets a simple `Counter` (via `make_counter()`). @@ -373,20 +342,12 @@ impl<'a> MakeBcbCounters<'a> { if one_path_to_target || self.bcb_predecessors(bcb).contains(&bcb) { let counter_kind = self.coverage_counters.make_counter(); if one_path_to_target { - debug!( - "{}{:?} gets a new counter: {:?}", - NESTED_INDENT.repeat(debug_indent_level), - bcb, - counter_kind, - ); + debug!("{bcb:?} gets a new counter: {counter_kind:?}"); } else { debug!( - "{}{:?} has itself as its own predecessor. It can't be part of its own \ - Expression sum, so it will get its own new counter: {:?}. (Note, the compiled \ - code will generate an infinite loop.)", - NESTED_INDENT.repeat(debug_indent_level), - bcb, - counter_kind, + "{bcb:?} has itself as its own predecessor. It can't be part of its own \ + Expression sum, so it will get its own new counter: {counter_kind:?}. \ + (Note, the compiled code will generate an infinite loop.)", ); } return self.coverage_counters.set_bcb_counter(bcb, counter_kind); @@ -396,24 +357,14 @@ impl<'a> MakeBcbCounters<'a> { // counters and/or expressions of its incoming edges. This will recursively get or create // counters for those incoming edges first, then call `make_expression()` to sum them up, // with additional intermediate expressions as needed. + let _sumup_debug_span = debug_span!("(preparing sum-up expression)").entered(); + let mut predecessors = self.bcb_predecessors(bcb).to_owned().into_iter(); - debug!( - "{}{:?} has multiple incoming edges and will get an expression that sums them up...", - NESTED_INDENT.repeat(debug_indent_level), - bcb, - ); - let first_edge_counter_operand = self.recursive_get_or_make_edge_counter_operand( - predecessors.next().unwrap(), - bcb, - debug_indent_level + 1, - )?; + let first_edge_counter_operand = + self.get_or_make_edge_counter_operand(predecessors.next().unwrap(), bcb); let mut some_sumup_edge_counter_operand = None; for predecessor in predecessors { - let edge_counter_operand = self.recursive_get_or_make_edge_counter_operand( - predecessor, - bcb, - debug_indent_level + 1, - )?; + let edge_counter_operand = self.get_or_make_edge_counter_operand(predecessor, bcb); if let Some(sumup_edge_counter_operand) = some_sumup_edge_counter_operand.replace(edge_counter_operand) { @@ -422,11 +373,7 @@ impl<'a> MakeBcbCounters<'a> { Op::Add, edge_counter_operand, ); - debug!( - "{}new intermediate expression: {:?}", - NESTED_INDENT.repeat(debug_indent_level), - intermediate_expression - ); + debug!("new intermediate expression: {intermediate_expression:?}"); let intermediate_expression_operand = intermediate_expression.as_term(); some_sumup_edge_counter_operand.replace(intermediate_expression_operand); } @@ -436,59 +383,36 @@ impl<'a> MakeBcbCounters<'a> { Op::Add, some_sumup_edge_counter_operand.unwrap(), ); - debug!( - "{}{:?} gets a new counter (sum of predecessor counters): {:?}", - NESTED_INDENT.repeat(debug_indent_level), - bcb, - counter_kind - ); + drop(_sumup_debug_span); + + debug!("{bcb:?} gets a new counter (sum of predecessor counters): {counter_kind:?}"); self.coverage_counters.set_bcb_counter(bcb, counter_kind) } + #[instrument(level = "debug", skip(self))] fn get_or_make_edge_counter_operand( &mut self, from_bcb: BasicCoverageBlock, to_bcb: BasicCoverageBlock, - ) -> Result<CovTerm, Error> { - self.recursive_get_or_make_edge_counter_operand(from_bcb, to_bcb, 1) - } - - fn recursive_get_or_make_edge_counter_operand( - &mut self, - from_bcb: BasicCoverageBlock, - to_bcb: BasicCoverageBlock, - debug_indent_level: usize, - ) -> Result<CovTerm, Error> { + ) -> CovTerm { // If the source BCB has only one successor (assumed to be the given target), an edge // counter is unnecessary. Just get or make a counter for the source BCB. let successors = self.bcb_successors(from_bcb).iter(); if successors.len() == 1 { - return self.recursive_get_or_make_counter_operand(from_bcb, debug_indent_level + 1); + return self.get_or_make_counter_operand(from_bcb); } // If the edge already has a counter, return it. if let Some(counter_kind) = self.coverage_counters.bcb_edge_counters.get(&(from_bcb, to_bcb)) { - debug!( - "{}Edge {:?}->{:?} already has a counter: {:?}", - NESTED_INDENT.repeat(debug_indent_level), - from_bcb, - to_bcb, - counter_kind - ); - return Ok(counter_kind.as_term()); + debug!("Edge {from_bcb:?}->{to_bcb:?} already has a counter: {counter_kind:?}"); + return counter_kind.as_term(); } // Make a new counter to count this edge. let counter_kind = self.coverage_counters.make_counter(); - debug!( - "{}Edge {:?}->{:?} gets a new counter: {:?}", - NESTED_INDENT.repeat(debug_indent_level), - from_bcb, - to_bcb, - counter_kind - ); + debug!("Edge {from_bcb:?}->{to_bcb:?} gets a new counter: {counter_kind:?}"); self.coverage_counters.set_bcb_edge_counter(from_bcb, to_bcb, counter_kind) } |