Struct rustc_middle::mir::Body

pub struct Body<'tcx> {

    pub basic_blocks: BasicBlocks<'tcx>,
    pub phase: MirPhase,
    pub pass_count: usize,
    pub source: MirSource<'tcx>,
    pub source_scopes: IndexVec<SourceScope, SourceScopeData<'tcx>>,
    pub coroutine: Option<Box<CoroutineInfo<'tcx>>>,
    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<ConstOperand<'tcx>>,
    pub mentioned_items: Vec<Spanned<MentionedItem<'tcx>>>,
    pub is_polymorphic: bool,
    pub injection_phase: Option<MirPhase>,
    pub tainted_by_errors: Option<ErrorGuaranteed>,
    pub coverage_info_hi: Option<Box<CoverageInfoHi>>,
    pub function_coverage_info: Option<Box<FunctionCoverageInfo>>,
}

The lowered representation of a single function.

Fields

basic_blocks: BasicBlocks<'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.

pass_count: usize

How many passses we have executed since starting the current phase. Used for debug output.

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.

coroutine: Option<Box<CoroutineInfo<'tcx>>>

Additional information carried by a MIR body when it is lowered from a coroutine.

Note that the coroutine drop shim, any promoted consts, and other synthetic MIR bodies that come from processing a coroutine body are not typically coroutines themselves, and should probably set this to None to avoid carrying redundant information.

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<ConstOperand<'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.

This is soundness-critical, we make a guarantee that all consts syntactically mentioned in a function have successfully evaluated if the function ever gets executed at runtime.

mentioned_items: Vec<Spanned<MentionedItem<'tcx>>>

Further items that were mentioned in this function and hence may become monomorphized, depending on optimizations. We use this to avoid optimization-dependent compile errors: the collector recursively traverses all “mentioned” items and evaluates all their required_consts.

This is not soundness-critical and the contents of this list are not a stable guarantee. All that’s relevant is that this set is optimization-level-independent, and that it includes everything that the collector would consider “used”. (For example, we currently compute this set after drop elaboration, so some drop calls that can never be reached are not considered “mentioned”.) See the documentation of CollectionMode in compiler/rustc_monomorphize/src/collector.rs for more context.

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.

injection_phase: Option<MirPhase>

The phase at which this MIR should be “injected” into the compilation process.

Everything that comes before this MirPhase should be skipped.

This is only Some if the function that this body comes from was annotated with rustc_custom_mir.

tainted_by_errors: Option<ErrorGuaranteed>

coverage_info_hi: Option<Box<CoverageInfoHi>>

Coverage information collected from THIR/MIR during MIR building, to be used by the InstrumentCoverage pass.

Only present if coverage is enabled and this function is eligible. Boxed to limit space overhead in non-coverage builds.

function_coverage_info: Option<Box<FunctionCoverageInfo>>

Per-function coverage information added by the InstrumentCoverage pass, to be used in conjunction with the coverage statements injected into this body’s blocks.

If -Cinstrument-coverage is not active, or if an individual function is not eligible for coverage, then this should always be None.

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, coroutine: Option<Box<CoroutineInfo<'tcx>>>, tainted_by_errors: Option<ErrorGuaranteed>, ) -> 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_mut( &mut self, ) -> &mut IndexVec<BasicBlock, BasicBlockData<'tcx>>

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

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

Returns an iterator over all user-declared mutable locals.

pub fn mut_vars_and_args_iter<'a>( &'a self, ) -> impl Iterator<Item = Local> + Captures<'tcx> + '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 drain_vars_and_temps<'a>( &'a mut self, ) -> impl Iterator<Item = LocalDecl<'tcx>> + 'a

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

Returns the source info associated with location.

pub fn span_for_ty_context(&self, ty_context: TyContext) -> Span

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

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

pub fn bound_return_ty(&self) -> EarlyBinder<'tcx, 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 stmt_at( &self, location: Location, ) -> Either<&Statement<'tcx>, &Terminator<'tcx>>

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

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

pub fn coroutine_layout_raw(&self) -> Option<&CoroutineLayout<'tcx>>

Prefer going through TyCtxt::coroutine_layout rather than using this directly.

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

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

pub fn coroutine_kind(&self) -> Option<CoroutineKind>

pub fn should_skip(&self) -> bool

pub fn is_custom_mir(&self) -> bool

fn try_const_mono_switchint<'a>( tcx: TyCtxt<'tcx>, instance: Instance<'tcx>, block: &'a BasicBlockData<'tcx>, ) -> Option<(u128, &'a SwitchTargets)>

If this basic block ends with a TerminatorKind::SwitchInt for which we can evaluate the dimscriminant in monomorphization, we return the discriminant bits and the SwitchTargets, just so the caller doesn’t also have to match on the terminator.

pub fn caller_location_span<T>( &self, source_info: SourceInfo, caller_location: Option<T>, tcx: TyCtxt<'tcx>, from_span: impl FnOnce(Span) -> T, ) -> T

For a Location in this scope, determine what the “caller location” at that point is. This is interesting because of inlining: the #[track_caller] attribute of inlined functions must be honored. Falls back to the tracked_caller value for #[track_caller] functions, or the function’s scope.

Trait Implementations

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

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

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

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

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

Returns a copy of the value.

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

Performs copy-assignment from source.

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

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

Formats the value using the given formatter.

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

fn decode(decoder: &mut D) -> Self

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

fn decode(__decoder: &mut __D) -> Self

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

fn encode(&self, __encoder: &mut __E)

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

fn local_decls(&self) -> &LocalDecls<'tcx>

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

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.

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

Performs the indexing (container[index]) operation.

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

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

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

impl ParameterizedOverTcx for Body<'static>

type Value<'tcx> = Body<'tcx>

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

fn decode(decoder: &mut D) -> &'tcx Self

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

fn try_fold_with<__F: FallibleTypeFolder<TyCtxt<'tcx>>>( self, __folder: &mut __F, ) -> Result<Self, __F::Error>

The entry point for folding. To fold a value t with a folder f call: t.try_fold_with(f).

fn fold_with<F>(self, folder: &mut F) -> Self

where F: TypeFolder<I>,

A convenient alternative to try_fold_with for use with infallible folders. Do not override this method, to ensure coherence with try_fold_with.

impl<'tcx> TypeVisitable<TyCtxt<'tcx>> for Body<'tcx>

fn visit_with<__V: TypeVisitor<TyCtxt<'tcx>>>( &self, __visitor: &mut __V, ) -> __V::Result

The entry point for visiting. To visit a value t with a visitor v call: t.visit_with(v).

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: 456 bytes