Struct rustc_mir_transform::ssa::SsaLocals

pub struct SsaLocals {
    assignments: IndexVec<Local, Set1<DefLocation>>,
    assignment_order: Vec<Local>,
    copy_classes: IndexVec<Local, Local>,
    direct_uses: IndexVec<Local, u32>,
    borrowed_locals: BitSet<Local>,
}

Fields

assignments: IndexVec<Local, Set1<DefLocation>>

Assignments to each local. This defines whether the local is SSA.

assignment_order: Vec<Local>

We visit the body in reverse postorder, to ensure each local is assigned before it is used. We remember the order in which we saw the assignments to compute the SSA values in a single pass.

copy_classes: IndexVec<Local, Local>

Copy equivalence classes between locals. See copy_classes for documentation.

direct_uses: IndexVec<Local, u32>

Number of “direct” uses of each local, ie. uses that are not dereferences. We ignore non-uses (Storage statements, debuginfo).

borrowed_locals: BitSet<Local>

Set of SSA locals that are immutably borrowed.

Implementations

impl SsaLocals

pub fn new<'tcx>( tcx: TyCtxt<'tcx>, body: &Body<'tcx>, param_env: ParamEnv<'tcx>, ) -> SsaLocals

pub fn num_locals(&self) -> usize

pub fn locals(&self) -> impl Iterator<Item = Local>

pub fn is_ssa(&self, local: Local) -> bool

pub fn num_direct_uses(&self, local: Local) -> u32

Return the number of uses if a local that are not “Deref”.

pub fn assignment_dominates( &self, dominators: &Dominators<BasicBlock>, local: Local, location: Location, ) -> bool

pub fn assignments<'a, 'tcx>( &'a self, body: &'a Body<'tcx>, ) -> impl Iterator<Item = (Local, &'a Rvalue<'tcx>, Location)> + 'a

pub fn for_each_assignment_mut<'tcx>( &self, basic_blocks: &mut IndexSlice<BasicBlock, BasicBlockData<'tcx>>, f: impl FnMut(Local, AssignedValue<'_, 'tcx>, Location), )

pub fn copy_classes(&self) -> &IndexSlice<Local, Local>

Compute the equivalence classes for locals, based on copy statements.

The returned vector maps each local to the one it copies. In the following case: _a = &mut _0 _b = move? _a _c = move? _a _d = move? _c We return the mapping _a => _a // not a copy so, represented by itself _b => _a _c => _a _d => _a // transitively through _c

Exception: we do not see through the return place, as it cannot be instantiated.

pub fn borrowed_locals(&self) -> &BitSet<Local>

Set of SSA locals that are immutably borrowed.

pub fn meet_copy_equivalence(&self, property: &mut BitSet<Local>)

Make a property uniform on a copy equivalence class by removing elements.

Layout

Note: Most layout information is completely unstable and may even differ between compilations. The only exception is types with certain repr(...) attributes. Please see the Rust Reference's “Type Layout” chapter for details on type layout guarantees.

Size: 128 bytes