diff options
| -rw-r--r-- | src/librustc_mir/transform/deaggregator.rs | 82 |
1 files changed, 41 insertions, 41 deletions
diff --git a/src/librustc_mir/transform/deaggregator.rs b/src/librustc_mir/transform/deaggregator.rs index b1c8a099403..3d8e013c5a7 100644 --- a/src/librustc_mir/transform/deaggregator.rs +++ b/src/librustc_mir/transform/deaggregator.rs @@ -31,55 +31,55 @@ impl<'tcx> MirPass<'tcx> for Deaggregator { None => { return; }, _ => {} }; + + // Do not trigger on constants. Could be revised in future if let MirSource::Fn(_) = source {} else { return; } let mut curr: usize = 0; for bb in mir.basic_blocks_mut() { - while let Some(idx) = get_aggregate_statement(curr, &bb.statements) { - // do the replacement - debug!("removing statement {:?}", idx); - let src_info = bb.statements[idx].source_info; - let mut suffix_stmts = bb.statements.split_off(idx); - let orig_stmt = suffix_stmts.remove(0); - let StatementKind::Assign(ref lhs, ref rhs) = orig_stmt.kind; - if let &Rvalue::Aggregate(ref agg_kind, ref operands) = rhs { - if let &AggregateKind::Adt(adt_def, variant, substs) = agg_kind { - let n = bb.statements.len(); - bb.statements.reserve(n + operands.len() + suffix_stmts.len()); - for (i, op) in operands.iter().enumerate() { - let ref variant_def = adt_def.variants[variant]; - let ty = variant_def.fields[variant].ty(tcx, substs); - let rhs = Rvalue::Use(op.clone()); + let idx = match get_aggregate_statement(curr, &bb.statements) { + Some(idx) => idx, + None => continue, + }; + // do the replacement + debug!("removing statement {:?}", idx); + let src_info = bb.statements[idx].source_info; + let suffix_stmts = bb.statements.split_off(idx+1); + let orig_stmt = bb.statements.pop().unwrap(); + let StatementKind::Assign(ref lhs, ref rhs) = orig_stmt.kind; + let (agg_kind, operands) = match rhs { + &Rvalue::Aggregate(ref agg_kind, ref operands) => (agg_kind, operands), + _ => span_bug!(src_info.span, "expected aggregate, not {:?}", rhs), + }; + let (adt_def, variant, substs) = match agg_kind { + &AggregateKind::Adt(adt_def, variant, substs) => (adt_def, variant, substs), + _ => span_bug!(src_info.span, "expected struct, not {:?}", rhs), + }; + let n = bb.statements.len(); + bb.statements.reserve(n + operands.len() + suffix_stmts.len()); + for (i, op) in operands.iter().enumerate() { + let ref variant_def = adt_def.variants[variant]; + let ty = variant_def.fields[variant].ty(tcx, substs); + let rhs = Rvalue::Use(op.clone()); - // since we don't handle enums, we don't need a cast - let lhs_cast = lhs.clone(); + // since we don't handle enums, we don't need a cast + let lhs_cast = lhs.clone(); - // if we handled enums: - // let lhs_cast = if adt_def.variants.len() > 1 { - // Lvalue::Projection(Box::new(LvalueProjection { - // base: ai.lhs.clone(), - // elem: ProjectionElem::Downcast(ai.adt_def, ai.variant), - // })) - // } else { - // lhs_cast - // }; + // FIXME we cannot deaggregate enums issue: 35186 - let lhs_proj = Lvalue::Projection(Box::new(LvalueProjection { - base: lhs_cast, - elem: ProjectionElem::Field(Field::new(i), ty), - })); - let new_statement = Statement { - source_info: src_info, - kind: StatementKind::Assign(lhs_proj, rhs), - }; - debug!("inserting: {:?} @ {:?}", new_statement, idx + i); - bb.statements.push(new_statement); - } - curr = bb.statements.len(); - bb.statements.extend(suffix_stmts); - } - } + let lhs_proj = Lvalue::Projection(Box::new(LvalueProjection { + base: lhs_cast, + elem: ProjectionElem::Field(Field::new(i), ty), + })); + let new_statement = Statement { + source_info: src_info, + kind: StatementKind::Assign(lhs_proj, rhs), + }; + debug!("inserting: {:?} @ {:?}", new_statement, idx + i); + bb.statements.push(new_statement); } + curr = bb.statements.len(); + bb.statements.extend(suffix_stmts); } } } |