Struct rustc_mir::transform::coverage::query::CoverageVisitor

pub(in transform::coverage::query) struct CoverageVisitor {
    info: CoverageInfo,
    add_missing_operands: bool,
}

The num_counters argument to llvm.instrprof.increment is the max counter_id + 1, or in other words, the number of counter value references injected into the MIR (plus 1 for the reserved ZERO counter, which uses counter ID 0 when included in an expression). Injected counters have a counter ID from 1..num_counters-1.

num_expressions is the number of counter expressions added to the MIR body.

Both num_counters and num_expressions are used to initialize new vectors, during backend code generate, to lookup counters and expressions by simple u32 indexes.

MIR optimization may split and duplicate some BasicBlock sequences, or optimize out some code including injected counters. (It is OK if some counters are optimized out, but those counters are still included in the total num_counters or num_expressions.) Simply counting the calls may not work; but computing the number of counters or expressions by adding 1 to the highest ID (for a given instrumented function) is valid.

This visitor runs twice, first with add_missing_operands set to false, to find the maximum counter ID and maximum expression ID based on their enum variant id fields; then, as a safeguard, with add_missing_operands set to true, to find any other counter or expression IDs referenced by expression operands, if not already seen.

Ideally, each operand ID in a MIR CoverageKind::Expression will have a separate MIR Coverage statement for the Counter or Expression with the referenced ID. but since current or future MIR optimizations can theoretically optimize out segments of a MIR, it may not be possible to guarantee this, so the second pass ensures the CoverageInfo counts include all referenced IDs.

Fields

info: CoverageInfo

add_missing_operands: bool

Implementations

impl CoverageVisitor

pub(in transform::coverage::query) fn update_num_counters(
    &mut self,
    counter_id: u32
)

Updates num_counters to the maximum encountered zero-based counter_id plus 1. Note the final computed number of counters should be the number of all CoverageKind::Counter statements in the MIR plus one for the implicit ZERO counter.

pub(in transform::coverage::query) fn update_num_expressions(
    &mut self,
    expression_id: u32
)

Computes an expression index for each expression ID, and updates num_expressions to the maximum encountered index plus 1.

pub(in transform::coverage::query) fn update_from_expression_operand(
    &mut self,
    operand_id: u32
)

Trait Implementations

impl<'_> Visitor<'_> for CoverageVisitor

pub fn visit_coverage(&mut self, coverage: &Coverage, _location: Location)

pub fn visit_body(&mut self, body: &Body<'tcx>)

pub fn visit_basic_block_data(
    &mut self,
    block: BasicBlock,
    data: &BasicBlockData<'tcx>
)

pub fn visit_source_scope_data(&mut self, scope_data: &SourceScopeData<'tcx>)

pub fn visit_statement(
    &mut self,
    statement: &Statement<'tcx>,
    location: Location
)

pub fn visit_assign(
    &mut self,
    place: &Place<'tcx>,
    rvalue: &Rvalue<'tcx>,
    location: Location
)

pub fn visit_terminator(
    &mut self,
    terminator: &Terminator<'tcx>,
    location: Location
)

pub fn visit_assert_message(
    &mut self,
    msg: &AssertKind<Operand<'tcx>>,
    location: Location
)

pub fn visit_rvalue(&mut self, rvalue: &Rvalue<'tcx>, location: Location)

pub fn visit_operand(&mut self, operand: &Operand<'tcx>, location: Location)

pub fn visit_ascribe_user_ty(
    &mut self,
    place: &Place<'tcx>,
    variance: &Variance,
    user_ty: &UserTypeProjection,
    location: Location
)

pub fn visit_retag(
    &mut self,
    kind: &RetagKind,
    place: &Place<'tcx>,
    location: Location
)

pub fn visit_place(
    &mut self,
    place: &Place<'tcx>,
    context: PlaceContext,
    location: Location
)

pub fn visit_projection(
    &mut self,
    local: Local,
    projection: &[ProjectionElem<Local, &'tcx TyS<'tcx>>],
    context: PlaceContext,
    location: Location
)

pub fn visit_projection_elem(
    &mut self,
    local: Local,
    proj_base: &[ProjectionElem<Local, &'tcx TyS<'tcx>>],
    elem: ProjectionElem<Local, &'tcx TyS<'tcx>>,
    context: PlaceContext,
    location: Location
)

pub fn super_place(
    &mut self,
    place: &Place<'tcx>,
    context: PlaceContext,
    location: Location
)

pub fn super_projection(
    &mut self,
    local: Local,
    projection: &[ProjectionElem<Local, &'tcx TyS<'tcx>>],
    context: PlaceContext,
    location: Location
)

pub fn super_projection_elem(
    &mut self,
    _local: Local,
    _proj_base: &[ProjectionElem<Local, &'tcx TyS<'tcx>>],
    elem: ProjectionElem<Local, &'tcx TyS<'tcx>>,
    _context: PlaceContext,
    location: Location
)

pub fn visit_constant(&mut self, constant: &Constant<'tcx>, location: Location)

pub fn visit_span(&mut self, span: &Span)

pub fn visit_source_info(&mut self, source_info: &SourceInfo)

pub fn visit_ty(&mut self, ty: &'tcx TyS<'tcx>, TyContext)

pub fn visit_user_type_projection(&mut self, ty: &UserTypeProjection)

pub fn visit_user_type_annotation(
    &mut self,
    index: UserTypeAnnotationIndex,
    ty: &CanonicalUserTypeAnnotation<'tcx>
)

pub fn visit_region(&mut self, region: &&'tcx RegionKind, Location)

pub fn visit_const(&mut self, constant: &&'tcx Const<'tcx>, Location)

pub fn visit_substs(&mut self, substs: &&'tcx List<GenericArg<'tcx>>, Location)

pub fn visit_local_decl(&mut self, local: Local, local_decl: &LocalDecl<'tcx>)

pub fn visit_var_debug_info(&mut self, var_debug_info: &VarDebugInfo<'tcx>)

pub fn visit_local(
    &mut self,
    _local: &Local,
    _context: PlaceContext,
    _location: Location
)

pub fn visit_source_scope(&mut self, scope: &SourceScope)

pub fn super_body(&mut self, body: &Body<'tcx>)

pub fn super_basic_block_data(
    &mut self,
    block: BasicBlock,
    data: &BasicBlockData<'tcx>
)

pub fn super_source_scope_data(&mut self, scope_data: &SourceScopeData<'tcx>)

pub fn super_statement(
    &mut self,
    statement: &Statement<'tcx>,
    location: Location
)

pub fn super_assign(
    &mut self,
    place: &Place<'tcx>,
    rvalue: &Rvalue<'tcx>,
    location: Location
)

pub fn super_terminator(
    &mut self,
    terminator: &Terminator<'tcx>,
    location: Location
)

pub fn super_assert_message(
    &mut self,
    msg: &AssertKind<Operand<'tcx>>,
    location: Location
)

pub fn super_rvalue(&mut self, rvalue: &Rvalue<'tcx>, location: Location)

pub fn super_operand(&mut self, operand: &Operand<'tcx>, location: Location)

pub fn super_ascribe_user_ty(
    &mut self,
    place: &Place<'tcx>,
    _variance: &Variance,
    user_ty: &UserTypeProjection,
    location: Location
)

pub fn super_coverage(&mut self, _coverage: &Coverage, _location: Location)

pub fn super_retag(
    &mut self,
    _kind: &RetagKind,
    place: &Place<'tcx>,
    location: Location
)

pub fn super_local_decl(&mut self, local: Local, local_decl: &LocalDecl<'tcx>)

pub fn super_var_debug_info(&mut self, var_debug_info: &VarDebugInfo<'tcx>)

pub fn super_source_scope(&mut self, _scope: &SourceScope)

pub fn super_constant(&mut self, constant: &Constant<'tcx>, location: Location)

pub fn super_span(&mut self, _span: &Span)

pub fn super_source_info(&mut self, source_info: &SourceInfo)

pub fn super_user_type_projection(&mut self, _ty: &UserTypeProjection)

pub fn super_user_type_annotation(
    &mut self,
    _index: UserTypeAnnotationIndex,
    ty: &CanonicalUserTypeAnnotation<'tcx>
)

pub fn super_ty(&mut self, _ty: &'tcx TyS<'tcx>)

pub fn super_region(&mut self, _region: &&'tcx RegionKind)

pub fn super_const(&mut self, _const: &&'tcx Const<'tcx>)

pub fn super_substs(&mut self, _substs: &&'tcx List<GenericArg<'tcx>>)

pub fn visit_location(&mut self, body: &Body<'tcx>, location: Location)