Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

coverage: Branch coverage support for let-else and if-let #124223

Merged
merged 2 commits into from
May 8, 2024
Merged
Show file tree
Hide file tree
Changes from all commits
Commits
File filter

Filter by extension

Filter by extension

Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
26 changes: 23 additions & 3 deletions compiler/rustc_mir_build/src/build/coverageinfo.rs
Original file line number Diff line number Diff line change
@@ -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>,
Expand Down Expand Up @@ -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(
Expand Down Expand Up @@ -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 and if-let (including let-chains) 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);
}
}
7 changes: 7 additions & 0 deletions compiler/rustc_mir_build/src/build/matches/mod.rs
Original file line number Diff line number Diff line change
Expand Up @@ -1968,6 +1968,9 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
false,
);

// If branch coverage is enabled, record this branch.
self.visit_coverage_conditional_let(pat, post_guard_block, otherwise_post_guard_block);

post_guard_block.unit()
}

Expand Down Expand Up @@ -2452,6 +2455,10 @@ 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()
});
Expand Down
23 changes: 16 additions & 7 deletions tests/coverage/branch/if-let.cov-map
Original file line number Diff line number Diff line change
@@ -1,13 +1,16 @@
Function name: if_let::if_let
Raw bytes (38): 0x[01, 01, 02, 05, 09, 09, 02, 06, 01, 0c, 01, 01, 10, 02, 03, 11, 00, 12, 05, 00, 16, 00, 1b, 02, 00, 1c, 02, 06, 09, 02, 0c, 02, 06, 07, 03, 05, 01, 02]
Raw bytes (45): 0x[01, 01, 02, 05, 09, 09, 02, 07, 01, 0c, 01, 01, 10, 20, 02, 09, 03, 0c, 00, 13, 02, 00, 11, 00, 12, 05, 00, 16, 00, 1b, 02, 00, 1c, 02, 06, 09, 02, 0c, 02, 06, 07, 03, 05, 01, 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, 17) to (start + 0, 18)
- Branch { true: Expression(0, Sub), false: Counter(2) } at (prev + 3, 12) to (start + 0, 19)
true = (c1 - c2)
false = c2
- Code(Expression(0, Sub)) at (prev + 0, 17) to (start + 0, 18)
= (c1 - c2)
- Code(Counter(1)) at (prev + 0, 22) to (start + 0, 27)
- Code(Expression(0, Sub)) at (prev + 0, 28) to (start + 2, 6)
Expand All @@ -17,20 +20,26 @@ Number of file 0 mappings: 6
= (c2 + (c1 - c2))

Function name: if_let::if_let_chain
Raw bytes (52): 0x[01, 01, 04, 01, 05, 05, 09, 0f, 0d, 05, 09, 08, 01, 17, 01, 00, 33, 02, 01, 11, 00, 12, 01, 00, 16, 00, 17, 0d, 01, 15, 00, 16, 02, 00, 1a, 00, 1b, 0d, 01, 05, 03, 06, 0f, 03, 0c, 02, 06, 0b, 03, 05, 01, 02]
Raw bytes (66): 0x[01, 01, 04, 01, 05, 05, 09, 0f, 0d, 05, 09, 0a, 01, 17, 01, 00, 33, 20, 02, 05, 01, 0c, 00, 13, 02, 00, 11, 00, 12, 01, 00, 16, 00, 17, 20, 0d, 09, 01, 10, 00, 17, 0d, 00, 15, 00, 16, 02, 00, 1a, 00, 1b, 0d, 01, 05, 03, 06, 0f, 03, 0c, 02, 06, 0b, 03, 05, 01, 02]
Number of files: 1
- file 0 => global file 1
Number of expressions: 4
- expression 0 operands: lhs = Counter(0), rhs = Counter(1)
- expression 1 operands: lhs = Counter(1), rhs = Counter(2)
- expression 2 operands: lhs = Expression(3, Add), rhs = Counter(3)
- expression 3 operands: lhs = Counter(1), rhs = Counter(2)
Number of file 0 mappings: 8
Number of file 0 mappings: 10
- Code(Counter(0)) at (prev + 23, 1) to (start + 0, 51)
- Code(Expression(0, Sub)) at (prev + 1, 17) to (start + 0, 18)
- Branch { true: Expression(0, Sub), false: Counter(1) } at (prev + 1, 12) to (start + 0, 19)
true = (c0 - c1)
false = c1
- Code(Expression(0, Sub)) at (prev + 0, 17) to (start + 0, 18)
= (c0 - c1)
- Code(Counter(0)) at (prev + 0, 22) to (start + 0, 23)
- Code(Counter(3)) at (prev + 1, 21) to (start + 0, 22)
- Branch { true: Counter(3), false: Counter(2) } at (prev + 1, 16) to (start + 0, 23)
true = c3
false = c2
- Code(Counter(3)) at (prev + 0, 21) to (start + 0, 22)
- Code(Expression(0, Sub)) at (prev + 0, 26) to (start + 0, 27)
= (c0 - c1)
- Code(Counter(3)) at (prev + 1, 5) to (start + 3, 6)
Expand Down
9 changes: 9 additions & 0 deletions tests/coverage/branch/if-let.coverage
Original file line number Diff line number Diff line change
Expand Up @@ -14,6 +14,9 @@
LL| |
LL| 3| if let Some(x) = input {
^2
------------------
| Branch (LL:12): [True: 2, False: 1]
------------------
LL| 2| say(x);
LL| 2| } else {
LL| 1| say("none");
Expand All @@ -24,8 +27,14 @@
LL| 15|fn if_let_chain(a: Option<&str>, b: Option<&str>) {
LL| 15| if let Some(x) = a
^12
------------------
| Branch (LL:12): [True: 12, False: 3]
------------------
LL| 12| && let Some(y) = b
^8
------------------
| Branch (LL:16): [True: 8, False: 4]
------------------
LL| 8| {
LL| 8| say(x);
LL| 8| say(y);
Expand Down
9 changes: 6 additions & 3 deletions tests/coverage/branch/let-else.cov-map
Original file line number Diff line number Diff line change
@@ -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)
Expand Down
3 changes: 3 additions & 0 deletions tests/coverage/branch/let-else.coverage
Original file line number Diff line number Diff line change
Expand Up @@ -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| | };
Expand Down
Loading