@@ -2,7 +2,7 @@ use std::assert_matches::assert_matches;
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use std::collections::hash_map::Entry;
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use rustc_data_structures::fx::FxHashMap;
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- use rustc_middle::mir::coverage::{BlockMarkerId, BranchSpan, CoverageKind};
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+ use rustc_middle::mir::coverage::{BlockMarkerId, BranchSpan, CoverageInfoHi, CoverageKind};
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use rustc_middle::mir::{self, BasicBlock, SourceInfo, UnOp};
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use rustc_middle::thir::{ExprId, ExprKind, Pat, Thir};
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use rustc_middle::ty::TyCtxt;
@@ -13,16 +13,25 @@ use crate::build::{Builder, CFG};
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mod mcdc;
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- pub(crate) struct BranchInfoBuilder {
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+ /// Collects coverage-related information during MIR building, to eventually be
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+ /// turned into a function's [`CoverageInfoHi`] when MIR building is complete.
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+ pub(crate) struct CoverageInfoBuilder {
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/// Maps condition expressions to their enclosing `!`, for better instrumentation.
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nots: FxHashMap<ExprId, NotInfo>,
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markers: BlockMarkerGen,
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- branch_spans: Vec<BranchSpan>,
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+ /// Present if branch coverage is enabled.
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+ branch_info: Option<BranchInfo>,
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+ /// Present if MC/DC coverage is enabled.
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mcdc_info: Option<MCDCInfoBuilder>,
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}
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+ #[derive(Default)]
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+ struct BranchInfo {
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+ branch_spans: Vec<BranchSpan>,
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+ }
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+
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#[derive(Clone, Copy)]
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struct NotInfo {
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/// When visiting the associated expression as a branch condition, treat this
@@ -62,20 +71,20 @@ impl BlockMarkerGen {
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}
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}
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- impl BranchInfoBuilder {
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- /// Creates a new branch info builder, but only if branch coverage instrumentation
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+ impl CoverageInfoBuilder {
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+ /// Creates a new coverage info builder, but only if coverage instrumentation
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/// is enabled and `def_id` represents a function that is eligible for coverage.
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pub(crate) fn new_if_enabled(tcx: TyCtxt<'_>, def_id: LocalDefId) -> Option<Self> {
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- if tcx.sess.instrument_coverage_branch() && tcx.is_eligible_for_coverage(def_id) {
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- Some(Self {
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- nots: FxHashMap::default(),
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- markers: BlockMarkerGen::default(),
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- branch_spans: vec![],
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- mcdc_info: tcx.sess.instrument_coverage_mcdc().then(MCDCInfoBuilder::new),
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- })
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- } else {
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- None
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+ if !tcx.sess.instrument_coverage() || !tcx.is_eligible_for_coverage(def_id) {
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+ return None;
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}
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+
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+ Some(Self {
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+ nots: FxHashMap::default(),
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+ markers: BlockMarkerGen::default(),
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+ branch_info: tcx.sess.instrument_coverage_branch().then(BranchInfo::default),
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+ mcdc_info: tcx.sess.instrument_coverage_mcdc().then(MCDCInfoBuilder::new),
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+ })
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}
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/// Unary `!` expressions inside an `if` condition are lowered by lowering
@@ -88,6 +97,12 @@ impl BranchInfoBuilder {
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pub(crate) fn visit_unary_not(&mut self, thir: &Thir<'_>, unary_not: ExprId) {
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assert_matches!(thir[unary_not].kind, ExprKind::Unary { op: UnOp::Not, .. });
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+ // The information collected by this visitor is only needed when branch
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+ // coverage or higher is enabled.
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+ if self.branch_info.is_none() {
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+ return;
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+ }
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+
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self.visit_with_not_info(
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thir,
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unary_not,
@@ -137,40 +152,40 @@ impl BranchInfoBuilder {
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false_block,
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inject_block_marker,
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);
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- } else {
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- let true_marker = self.markers.inject_block_marker(cfg, source_info, true_block);
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- let false_marker = self.markers.inject_block_marker(cfg, source_info, false_block);
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-
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- self.branch_spans.push(BranchSpan {
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- span: source_info.span,
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- true_marker,
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- false_marker,
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- });
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+ return;
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}
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+
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+ // Bail out if branch coverage is not enabled.
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+ let Some(branch_info) = self.branch_info.as_mut() else { return };
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+
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+ let true_marker = self.markers.inject_block_marker(cfg, source_info, true_block);
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+ let false_marker = self.markers.inject_block_marker(cfg, source_info, false_block);
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+
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+ branch_info.branch_spans.push(BranchSpan {
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+ span: source_info.span,
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+ true_marker,
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+ false_marker,
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+ });
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}
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- pub(crate) fn into_done(self) -> Option<Box<mir::coverage::BranchInfo>> {
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- let Self {
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- nots: _,
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- markers: BlockMarkerGen { num_block_markers },
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- branch_spans,
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- mcdc_info,
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- } = self;
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+ pub(crate) fn into_done(self) -> Box<CoverageInfoHi> {
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+ let Self { nots: _, markers: BlockMarkerGen { num_block_markers }, branch_info, mcdc_info } =
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+ self;
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- if num_block_markers == 0 {
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- assert!(branch_spans.is_empty());
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- return None;
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- }
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+ let branch_spans =
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+ branch_info.map(|branch_info| branch_info.branch_spans).unwrap_or_default();
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let (mcdc_decision_spans, mcdc_branch_spans) =
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mcdc_info.map(MCDCInfoBuilder::into_done).unwrap_or_default();
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- Some(Box::new(mir::coverage::BranchInfo {
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+ // For simplicity, always return an info struct (without Option), even
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+ // if there's nothing interesting in it.
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+ Box::new(CoverageInfoHi {
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num_block_markers,
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branch_spans,
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mcdc_branch_spans,
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mcdc_decision_spans,
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- }))
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+ })
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}
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}
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@@ -184,7 +199,7 @@ impl<'tcx> Builder<'_, 'tcx> {
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block: &mut BasicBlock,
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) {
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// Bail out if condition coverage is not enabled for this function.
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- let Some(branch_info ) = self.coverage_branch_info .as_mut() else { return };
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+ let Some(coverage_info ) = self.coverage_info .as_mut() else { return };
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if !self.tcx.sess.instrument_coverage_condition() {
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return;
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};
@@ -224,7 +239,7 @@ impl<'tcx> Builder<'_, 'tcx> {
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);
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// Separate path for handling branches when MC/DC is enabled.
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- branch_info .register_two_way_branch(
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+ coverage_info .register_two_way_branch(
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self.tcx,
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&mut self.cfg,
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source_info,
@@ -247,12 +262,12 @@ impl<'tcx> Builder<'_, 'tcx> {
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mut then_block: BasicBlock,
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mut else_block: BasicBlock,
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) {
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- // Bail out if branch coverage is not enabled for this function.
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- let Some(branch_info ) = self.coverage_branch_info .as_mut() else { return };
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+ // Bail out if coverage is not enabled for this function.
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+ let Some(coverage_info ) = self.coverage_info .as_mut() else { return };
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// If this condition expression is nested within one or more `!` expressions,
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// replace it with the enclosing `!` collected by `visit_unary_not`.
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- if let Some(&NotInfo { enclosing_not, is_flipped }) = branch_info .nots.get(&expr_id) {
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+ if let Some(&NotInfo { enclosing_not, is_flipped }) = coverage_info .nots.get(&expr_id) {
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expr_id = enclosing_not;
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if is_flipped {
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std::mem::swap(&mut then_block, &mut else_block);
@@ -261,7 +276,7 @@ impl<'tcx> Builder<'_, 'tcx> {
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let source_info = SourceInfo { span: self.thir[expr_id].span, scope: self.source_scope };
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- branch_info .register_two_way_branch(
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+ coverage_info .register_two_way_branch(
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self.tcx,
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&mut self.cfg,
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source_info,
@@ -280,13 +295,11 @@ impl<'tcx> Builder<'_, 'tcx> {
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true_block: BasicBlock,
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false_block: BasicBlock,
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) {
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- // Bail out if branch coverage is not enabled for this function.
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- let Some(branch_info) = self.coverage_branch_info.as_mut() else { return };
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-
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- // FIXME(#124144) This may need special handling when MC/DC is enabled.
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+ // Bail out if coverage is not enabled for this function.
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+ let Some(coverage_info) = self.coverage_info.as_mut() else { return };
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let source_info = SourceInfo { span: pattern.span, scope: self.source_scope };
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- branch_info .register_two_way_branch(
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+ coverage_info .register_two_way_branch(
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self.tcx,
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&mut self.cfg,
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source_info,
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