Struct rustc_middle::mir::Body

pub struct Body<'tcx> {
    basic_blocks: IndexVec<BasicBlock, BasicBlockData<'tcx>>,
    pub phase: MirPhase,
    pub source: MirSource<'tcx>,
    pub source_scopes: IndexVec<SourceScope, SourceScopeData<'tcx>>,
    pub yield_ty: Option<Ty<'tcx>>,
    pub generator_drop: Option<Box<Body<'tcx>>>,
    pub generator_layout: Option<GeneratorLayout<'tcx>>,
    pub generator_kind: Option<GeneratorKind>,
    pub local_decls: IndexVec<Local, LocalDecl<'tcx>>,
    pub user_type_annotations: CanonicalUserTypeAnnotations<'tcx>,
    pub arg_count: usize,
    pub spread_arg: Option<Local>,
    pub var_debug_info: Vec<VarDebugInfo<'tcx>>,
    pub span: Span,
    pub required_consts: Vec<Constant<'tcx>>,
    pub is_polymorphic: bool,
    predecessor_cache: PredecessorCache,
}

The lowered representation of a single function.

Fields

basic_blocks: IndexVec<BasicBlock, BasicBlockData<'tcx>>

A list of basic blocks. References to basic block use a newtyped index type BasicBlock that indexes into this vector.

phase: MirPhase

Records how far through the "desugaring and optimization" process this particular MIR has traversed. This is particularly useful when inlining, since in that context we instantiate the promoted constants and add them to our promoted vector -- but those promoted items have already been optimized, whereas ours have not. This field allows us to see the difference and forego optimization on the inlined promoted items.

source: MirSource<'tcx>

source_scopes: IndexVec<SourceScope, SourceScopeData<'tcx>>

A list of source scopes; these are referenced by statements and used for debuginfo. Indexed by a SourceScope.

yield_ty: Option<Ty<'tcx>>

The yield type of the function, if it is a generator.

generator_drop: Option<Box<Body<'tcx>>>

Generator drop glue.

generator_layout: Option<GeneratorLayout<'tcx>>

The layout of a generator. Produced by the state transformation.

generator_kind: Option<GeneratorKind>

If this is a generator then record the type of source expression that caused this generator to be created.

local_decls: IndexVec<Local, LocalDecl<'tcx>>

Declarations of locals.

The first local is the return value pointer, followed by arg_count locals for the function arguments, followed by any user-declared variables and temporaries.

user_type_annotations: CanonicalUserTypeAnnotations<'tcx>

User type annotations.

arg_count: usize

The number of arguments this function takes.

Starting at local 1, arg_count locals will be provided by the caller and can be assumed to be initialized.

If this MIR was built for a constant, this will be 0.

spread_arg: Option<Local>

Mark an argument local (which must be a tuple) as getting passed as its individual components at the LLVM level.

This is used for the "rust-call" ABI.

var_debug_info: Vec<VarDebugInfo<'tcx>>

Debug information pertaining to user variables, including captures.

span: Span

A span representing this MIR, for error reporting.

required_consts: Vec<Constant<'tcx>>

Constants that are required to evaluate successfully for this MIR to be well-formed. We hold in this field all the constants we are not able to evaluate yet.

is_polymorphic: bool

Does this body use generic parameters. This is used for the ConstEvaluatable check.

Note that this does not actually mean that this body is not computable right now. The repeat count in the following example is polymorphic, but can still be evaluated without knowing anything about the type parameter T.

fn test<T>() {
    let _ = [0; std::mem::size_of::<*mut T>()];
}

WARNING: Do not change this flags after the MIR was originally created, even if an optimization removed the last mention of all generic params. We do not want to rely on optimizations and potentially allow things like [u8; std::mem::size_of::<T>() * 0] due to this.

predecessor_cache: PredecessorCache

Implementations

impl<'tcx> Body<'tcx>

pub fn new(
    source: MirSource<'tcx>,
    basic_blocks: IndexVec<BasicBlock, BasicBlockData<'tcx>>,
    source_scopes: IndexVec<SourceScope, SourceScopeData<'tcx>>,
    local_decls: IndexVec<Local, LocalDecl<'tcx>>,
    user_type_annotations: CanonicalUserTypeAnnotations<'tcx>,
    arg_count: usize,
    var_debug_info: Vec<VarDebugInfo<'tcx>>,
    span: Span,
    generator_kind: Option<GeneratorKind>
) -> Self

pub fn new_cfg_only(
    basic_blocks: IndexVec<BasicBlock, BasicBlockData<'tcx>>
) -> Self

Returns a partially initialized MIR body containing only a list of basic blocks.

The returned MIR contains no LocalDecls (even for the return place) or source scopes. It is only useful for testing but cannot be #[cfg(test)] because it is used in a different crate.

pub fn basic_blocks(&self) -> &IndexVec<BasicBlock, BasicBlockData<'tcx>>

pub fn basic_blocks_mut(
    &mut self
) -> &mut IndexVec<BasicBlock, BasicBlockData<'tcx>>

pub fn basic_blocks_and_local_decls_mut(
    &mut self
) -> (&mut IndexVec<BasicBlock, BasicBlockData<'tcx>>, &mut IndexVec<Local, LocalDecl<'tcx>>)

pub fn basic_blocks_local_decls_mut_and_var_debug_info(
    &mut self
) -> (&mut IndexVec<BasicBlock, BasicBlockData<'tcx>>, &mut IndexVec<Local, LocalDecl<'tcx>>, &mut Vec<VarDebugInfo<'tcx>>)

pub fn is_cfg_cyclic(&self) -> bool

Returns true if a cycle exists in the control-flow graph that is reachable from the START_BLOCK.

pub fn local_kind(&self, local: Local) -> LocalKind

pub fn temps_iter<'a>(&'a self) -> impl Iterator<Item = Local> + 'a

Returns an iterator over all temporaries.

pub fn vars_iter<'a>(&'a self) -> impl Iterator<Item = Local> + 'a

Returns an iterator over all user-declared locals.

pub fn mut_vars_iter<'a>(&'a self) -> impl Iterator<Item = Local> + 'a

Returns an iterator over all user-declared mutable locals.

pub fn mut_vars_and_args_iter<'a>(&'a self) -> impl Iterator<Item = Local> + 'a

Returns an iterator over all user-declared mutable arguments and locals.

pub fn args_iter(&self) -> impl Iterator<Item = Local> + ExactSizeIterator

Returns an iterator over all function arguments.

pub fn vars_and_temps_iter(
    &self
) -> impl DoubleEndedIterator<Item = Local> + ExactSizeIterator

Returns an iterator over all user-defined variables and compiler-generated temporaries (all locals that are neither arguments nor the return place).

pub fn make_statement_nop(&mut self, location: Location)

Changes a statement to a nop. This is both faster than deleting instructions and avoids invalidating statement indices in Locations.

pub fn source_info(&self, location: Location) -> &SourceInfo

Returns the source info associated with location.

pub fn return_ty(&self) -> Ty<'tcx>

Returns the return type; it always return first element from local_decls array.

pub fn terminator_loc(&self, bb: BasicBlock) -> Location

Gets the location of the terminator for the given block.

pub fn predecessors(
    &self
) -> impl Deref<Target = IndexVec<BasicBlock, SmallVec<[BasicBlock; 4]>>> + '_

pub fn dominators(&self) -> Dominators<BasicBlock>

Trait Implementations

impl<'tcx> ArenaAllocatable<'tcx, Body<'tcx>> for Body<'tcx>

pub fn allocate_on<'a>(self, arena: &'a Arena<'tcx>) -> &'a mut Self

pub fn allocate_from_iter<'a>(
    arena: &'a Arena<'tcx>,
    iter: impl IntoIterator<Item = Self>
) -> &'a mut [Self]

impl<'tcx> Clone for Body<'tcx>

pub fn clone(&self) -> Body<'tcx>

Returns a copy of the value.

pub fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<'tcx> Debug for Body<'tcx>

pub fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<'tcx, D: TyDecoder<'tcx>> Decodable<D> for &'tcx Body<'tcx>

pub fn decode(decoder: &mut D) -> Result<Self, D::Error>

impl<'tcx, __D: TyDecoder<'tcx>> Decodable<__D> for Body<'tcx>

pub fn decode(__decoder: &mut __D) -> Result<Self, <__D as Decoder>::Error>

impl<'tcx> DirectedGraph for Body<'tcx>

type Node = BasicBlock

impl<'tcx, E: TyEncoder<'tcx>> Encodable<E> for &'tcx Body<'tcx>

pub fn encode(&self, e: &mut E) -> Result<(), E::Error>

impl<'tcx, __E: TyEncoder<'tcx>> Encodable<__E> for Body<'tcx>

pub fn encode(&self, __encoder: &mut __E) -> Result<(), <__E as Encoder>::Error>

impl<'graph, 'tcx> GraphPredecessors<'graph> for Body<'tcx>

type Item = BasicBlock

type Iter = IntoIter<[BasicBlock; 4]>

impl<'a, 'b> GraphSuccessors<'b> for Body<'a>

type Item = BasicBlock

type Iter = Cloned<Successors<'b>>

impl<'tcx> HasLocalDecls<'tcx> for Body<'tcx>

pub fn local_decls(&self) -> &IndexVec<Local, LocalDecl<'tcx>>

impl<'tcx, '__ctx> HashStable<StableHashingContext<'__ctx>> for Body<'tcx>

pub fn hash_stable(
    &self,
    __hcx: &mut StableHashingContext<'__ctx>,
    __hasher: &mut StableHasher
)

impl<'tcx> Index<BasicBlock> for Body<'tcx>

type Output = BasicBlockData<'tcx>

The returned type after indexing.

pub fn index(&self, index: BasicBlock) -> &BasicBlockData<'tcx>

Performs the indexing (container[index]) operation.

impl<'tcx> IndexMut<BasicBlock> for Body<'tcx>

pub fn index_mut(&mut self, index: BasicBlock) -> &mut BasicBlockData<'tcx>

Performs the mutable indexing (container[index]) operation.

impl<'tcx, D: TyDecoder<'tcx>> RefDecodable<'tcx, D> for Body<'tcx>

pub fn decode(decoder: &mut D) -> Result<&'tcx Self, D::Error>

impl<'tcx> TypeFoldable<'tcx> for Body<'tcx>

pub fn super_fold_with<__F: TypeFolder<'tcx>>(self, __folder: &mut __F) -> Self

pub fn super_visit_with<__F: TypeVisitor<'tcx>>(
    &self,
    __folder: &mut __F
) -> ControlFlow<__F::BreakTy>

pub fn fold_with<F: TypeFolder<'tcx>>(self, folder: &mut F) -> Self

pub fn visit_with<V: TypeVisitor<'tcx>>(
    &self,
    visitor: &mut V
) -> ControlFlow<V::BreakTy>

pub fn has_vars_bound_at_or_above(&self, binder: DebruijnIndex) -> bool

Returns true if self has any late-bound regions that are either bound by binder or bound by some binder outside of binder. If binder is ty::INNERMOST, this indicates whether there are any late-bound regions that appear free.

pub fn has_vars_bound_above(&self, binder: DebruijnIndex) -> bool

Returns true if this self has any regions that escape binder (and hence are not bound by it).

pub fn has_escaping_bound_vars(&self) -> bool

pub fn has_type_flags(&self, flags: TypeFlags) -> bool

pub fn has_projections(&self) -> bool

pub fn has_opaque_types(&self) -> bool

pub fn references_error(&self) -> bool

pub fn has_param_types_or_consts(&self) -> bool

pub fn has_infer_regions(&self) -> bool

pub fn has_infer_types(&self) -> bool

pub fn has_infer_types_or_consts(&self) -> bool

pub fn needs_infer(&self) -> bool

pub fn has_placeholders(&self) -> bool

pub fn needs_subst(&self) -> bool

pub fn has_free_regions(&self) -> bool

"Free" regions in this context means that it has any region that is not (a) erased or (b) late-bound.

pub fn has_erased_regions(&self) -> bool

pub fn has_erasable_regions(&self) -> bool

True if there are any un-erased free regions.

pub fn is_global(&self) -> bool

Indicates whether this value references only 'global' generic parameters that are the same regardless of what fn we are in. This is used for caching.

pub fn has_late_bound_regions(&self) -> bool

True if there are any late-bound regions

pub fn still_further_specializable(&self) -> bool

Indicates whether this value still has parameters/placeholders/inference variables which could be replaced later, in a way that would change the results of impl specialization.

impl<'tcx> WithNumNodes for Body<'tcx>

pub fn num_nodes(&self) -> usize

impl<'tcx> WithPredecessors for Body<'tcx>

pub fn predecessors(&self, node: Self::Node) -> Self::Iter

impl<'tcx> WithStartNode for Body<'tcx>

pub fn start_node(&self) -> Self::Node

impl<'tcx> WithSuccessors for Body<'tcx>

pub fn successors(&self, node: Self::Node) -> Self::Iter

pub fn depth_first_search(&self, from: Self::Node) -> DepthFirstSearch<'_, Self> where
    Self: WithNumNodes,