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coverage: Add branch coverage support for let-else

This commit is contained in:
Zalathar 2024-04-17 11:41:40 +10:00
parent 47314eb427
commit c9dd07dd5e
4 changed files with 36 additions and 6 deletions

View file

@ -1,17 +1,18 @@
mod mcdc;
use std::assert_matches::assert_matches;
use std::collections::hash_map::Entry;
use rustc_data_structures::fx::FxHashMap;
use rustc_middle::mir::coverage::{BlockMarkerId, BranchSpan, CoverageKind};
use rustc_middle::mir::{self, BasicBlock, SourceInfo, UnOp};
use rustc_middle::thir::{ExprId, ExprKind, Thir};
use rustc_middle::thir::{ExprId, ExprKind, Pat, Thir};
use rustc_middle::ty::TyCtxt;
use rustc_span::def_id::LocalDefId;
use crate::build::coverageinfo::mcdc::MCDCInfoBuilder;
use crate::build::{Builder, CFG};
mod mcdc;
pub(crate) struct BranchInfoBuilder {
/// Maps condition expressions to their enclosing `!`, for better instrumentation.
nots: FxHashMap<ExprId, NotInfo>,
@ -155,7 +156,7 @@ impl BranchInfoBuilder {
}
}
impl Builder<'_, '_> {
impl<'tcx> Builder<'_, 'tcx> {
/// If branch coverage is enabled, inject marker statements into `then_block`
/// and `else_block`, and record their IDs in the table of branch spans.
pub(crate) fn visit_coverage_branch_condition(
@ -195,4 +196,23 @@ impl Builder<'_, '_> {
branch_info.add_two_way_branch(&mut self.cfg, source_info, then_block, else_block);
}
/// If branch coverage is enabled, inject marker statements into `true_block`
/// and `false_block`, and record their IDs in the table of branches.
///
/// Used to instrument let-else for branch coverage.
pub(crate) fn visit_coverage_conditional_let(
&mut self,
pattern: &Pat<'tcx>, // Pattern that has been matched when the true path is taken
true_block: BasicBlock,
false_block: BasicBlock,
) {
// Bail out if branch coverage is not enabled for this function.
let Some(branch_info) = self.coverage_branch_info.as_mut() else { return };
// FIXME(#124144) This may need special handling when MC/DC is enabled.
let source_info = SourceInfo { span: pattern.span, scope: self.source_scope };
branch_info.add_two_way_branch(&mut self.cfg, source_info, true_block, false_block);
}
}

View file

@ -2452,6 +2452,10 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
None,
true,
);
// If branch coverage is enabled, record this branch.
this.visit_coverage_conditional_let(pattern, matching, failure);
this.break_for_else(failure, this.source_info(initializer_span));
matching.unit()
});

View file

@ -1,13 +1,16 @@
Function name: let_else::let_else
Raw bytes (38): 0x[01, 01, 02, 05, 09, 09, 02, 06, 01, 0c, 01, 01, 10, 02, 03, 0e, 00, 0f, 05, 00, 13, 00, 18, 09, 01, 09, 01, 0f, 02, 04, 05, 00, 0b, 07, 01, 01, 00, 02]
Raw bytes (45): 0x[01, 01, 02, 05, 09, 09, 02, 07, 01, 0c, 01, 01, 10, 20, 02, 09, 03, 09, 00, 10, 02, 00, 0e, 00, 0f, 05, 00, 13, 00, 18, 09, 01, 09, 01, 0f, 02, 04, 05, 00, 0b, 07, 01, 01, 00, 02]
Number of files: 1
- file 0 => global file 1
Number of expressions: 2
- expression 0 operands: lhs = Counter(1), rhs = Counter(2)
- expression 1 operands: lhs = Counter(2), rhs = Expression(0, Sub)
Number of file 0 mappings: 6
Number of file 0 mappings: 7
- Code(Counter(0)) at (prev + 12, 1) to (start + 1, 16)
- Code(Expression(0, Sub)) at (prev + 3, 14) to (start + 0, 15)
- Branch { true: Expression(0, Sub), false: Counter(2) } at (prev + 3, 9) to (start + 0, 16)
true = (c1 - c2)
false = c2
- Code(Expression(0, Sub)) at (prev + 0, 14) to (start + 0, 15)
= (c1 - c2)
- Code(Counter(1)) at (prev + 0, 19) to (start + 0, 24)
- Code(Counter(2)) at (prev + 1, 9) to (start + 1, 15)

View file

@ -14,6 +14,9 @@
LL| |
LL| 3| let Some(x) = value else {
^2
------------------
| Branch (LL:9): [True: 2, False: 1]
------------------
LL| 1| say("none");
LL| 1| return;
LL| | };