Struct rustc_typeck::check::regionck::RegionCtxt
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[src]
pub struct RegionCtxt<'a, 'gcx: 'a + 'tcx, 'tcx: 'a> {
pub fcx: &'a FnCtxt<'a, 'gcx, 'tcx>,
// some fields omitted
}rustc_private)Fields
fcx: &'a FnCtxt<'a, 'gcx, 'tcx>
rustc_private)Methods
impl<'a, 'gcx, 'tcx> RegionCtxt<'a, 'gcx, 'tcx>[src]
fn new(fcx: &'a FnCtxt<'a, 'gcx, 'tcx>, initial_repeating_scope: RepeatingScope, initial_body_id: NodeId, subject: SubjectNode) -> RegionCtxt<'a, 'gcx, 'tcx>
fn resolve_type(&self, unresolved_ty: Ty<'tcx>) -> Ty<'tcx>
rustc_private)Try to resolve the type for the given node, returning t_err if an error results. Note that we never care about the details of the error, the same error will be detected and reported in the writeback phase.
Note one important point: we do not attempt to resolve region variables here. This is because regionck is essentially adding constraints to those region variables and so may yet influence how they are resolved.
Consider this silly example:
fn borrow(x: &i32) -> &i32 {x} fn foo(x: @i32) -> i32 { // block: B let b = borrow(x); // region: <R0> *b }
Here, the region of b will be <R0>. <R0> is constrained to be some subregion of the
block B and some superregion of the call. If we forced it now, we'd choose the smaller
region (the call). But that would make the *b illegal. Since we don't resolve, the type
of b will be &<R0>.i32 and then *b will require that <R0> be bigger than the let and
the *b expression, so we will effectively resolve <R0> to be the block B.
fn resolve_expr_type_adjusted(&mut self, expr: &Expr) -> Ty<'tcx>
rustc_private)Try to resolve the type for the given node.
impl<'a, 'gcx, 'tcx> RegionCtxt<'a, 'gcx, 'tcx>[src]
fn mk_subregion_due_to_dereference(&mut self, deref_span: Span, minimum_lifetime: Region, maximum_lifetime: Region)
fn type_must_outlive(&self, origin: SubregionOrigin<'tcx>, ty: Ty<'tcx>, region: Region)
rustc_private)Ensures that type is well-formed in region, which implies (among
other things) that all borrowed data reachable via ty outlives
region.
Methods from Deref<Target=FnCtxt<'a, 'gcx, 'tcx>>
fn check_match(&self, expr: &'gcx Expr, discrim: &'gcx Expr, arms: &'gcx [Arm], expected: Expectation<'tcx>, match_src: MatchSource)
fn resolve_type_vars_in_expr(&self, e: &Expr)
fn resolve_type_vars_in_fn(&self, decl: &FnDecl, blk: &Block)
fn regionck_expr(&self, e: &Expr)
fn regionck_item(&self, item_id: NodeId, span: Span, wf_tys: &[Ty<'tcx>])
rustc_private)Region checking during the WF phase for items. wf_tys are the
types from which we should derive implied bounds, if any.
fn regionck_fn(&self, fn_id: NodeId, fn_span: Span, decl: &FnDecl, blk: &Block)
fn try_coerce(&self, expr: &Expr, target: Ty<'tcx>) -> RelateResult<'tcx, Ty<'tcx>>
rustc_private)Attempt to coerce an expression to a type, and return the adjusted type of the expression, if successful. Adjustments are only recorded if the coercion succeeded. The expressions must not have any pre-existing adjustments.
fn try_find_coercion_lub<'b, E, I>(&self, origin: TypeOrigin, exprs: E, prev_ty: Ty<'tcx>, new: &'b Expr) -> RelateResult<'tcx, Ty<'tcx>> where E: Fn() -> I, I: IntoIterator<Item=&'b Expr>
rustc_private)Given some expressions, their known unified type and another expression, tries to unify the types, potentially inserting coercions on any of the provided expressions and returns their LUB (aka "common supertype").
fn demand_suptype(&self, sp: Span, expected: Ty<'tcx>, actual: Ty<'tcx>)
fn demand_eqtype(&self, sp: Span, expected: Ty<'tcx>, actual: Ty<'tcx>)
fn demand_coerce(&self, expr: &Expr, expected: Ty<'tcx>)
fn require_same_types(&self, span: Span, t1: Ty<'tcx>, t2: Ty<'tcx>, msg: &str) -> bool
fn confirm_method(&self, span: Span, self_expr: &'gcx Expr, call_expr: &'gcx Expr, unadjusted_self_ty: Ty<'tcx>, pick: Pick<'tcx>, supplied_method_types: Vec<Ty<'tcx>>) -> MethodCallee<'tcx>
fn probe_method(&self, span: Span, mode: Mode, item_name: Name, self_ty: Ty<'tcx>, scope_expr_id: NodeId) -> PickResult<'tcx>
fn report_method_error(&self, span: Span, rcvr_ty: Ty<'tcx>, item_name: Name, rcvr_expr: Option<&Expr>, error: MethodError<'tcx>)
fn method_exists(&self, span: Span, method_name: Name, self_ty: Ty<'tcx>, call_expr_id: NodeId, allow_private: bool) -> bool
rustc_private)Determines whether the type self_ty supports a method name method_name or not.
fn lookup_method(&self, span: Span, method_name: Name, self_ty: Ty<'tcx>, supplied_method_types: Vec<Ty<'tcx>>, call_expr: &'gcx Expr, self_expr: &'gcx Expr) -> Result<MethodCallee<'tcx>, MethodError<'tcx>>
rustc_private)Performs method lookup. If lookup is successful, it will return the callee
and store an appropriate adjustment for the self-expr. In some cases it may
report an error (e.g., invoking the drop method).
Arguments
Given a method call like foo.bar::<T1,...Tn>(...):
fcx: the surroundingFnCtxt(!)span: the span for the method callmethod_name: the name of the method being called (bar)self_ty: the (unadjusted) type of the self expression (foo)supplied_method_types: the explicit method type parameters, if any (T1..Tn)self_expr: the self expression (foo)
fn lookup_method_in_trait(&self, span: Span, self_expr: Option<&Expr>, m_name: Name, trait_def_id: DefId, self_ty: Ty<'tcx>, opt_input_types: Option<Vec<Ty<'tcx>>>) -> Option<MethodCallee<'tcx>>
fn lookup_method_in_trait_adjusted(&self, span: Span, self_expr: Option<&Expr>, m_name: Name, trait_def_id: DefId, autoderefs: usize, unsize: bool, self_ty: Ty<'tcx>, opt_input_types: Option<Vec<Ty<'tcx>>>) -> Option<MethodCallee<'tcx>>
rustc_private)lookup_in_trait_adjusted is used for overloaded operators.
It does a very narrow slice of what the normal probe/confirm path does.
In particular, it doesn't really do any probing: it simply constructs
an obligation for aparticular trait with the given self-type and checks
whether that trait is implemented.
FIXME(#18741) -- It seems likely that we can consolidate some of this code with the other method-lookup code. In particular, autoderef on index is basically identical to autoderef with normal probes, except that the test also looks for built-in indexing. Also, the second half of this method is basically the same as confirmation.
fn resolve_ufcs(&self, span: Span, method_name: Name, self_ty: Ty<'tcx>, expr_id: NodeId) -> Result<Def, MethodError<'tcx>>
fn trait_item(&self, trait_def_id: DefId, item_name: Name) -> Option<ImplOrTraitItem<'tcx>>
rustc_private)Find item with name item_name defined in trait_def_id
and return it, or None, if no such item.
fn impl_item(&self, impl_def_id: DefId, item_name: Name) -> Option<ImplOrTraitItem<'tcx>>
fn closure_analyze_fn(&self, body: &Block)
fn closure_analyze_const(&self, body: &Expr)
fn check_expr_closure(&self, expr: &Expr, _capture: CaptureClause, decl: &'gcx FnDecl, body: &'gcx Block, expected: Expectation<'tcx>)
fn check_call(&self, call_expr: &'gcx Expr, callee_expr: &'gcx Expr, arg_exprs: &'gcx [P<Expr>], expected: Expectation<'tcx>)
fn check_binop_assign(&self, expr: &'gcx Expr, op: BinOp, lhs_expr: &'gcx Expr, rhs_expr: &'gcx Expr)
rustc_private)Check a a <op>= b
fn check_binop(&self, expr: &'gcx Expr, op: BinOp, lhs_expr: &'gcx Expr, rhs_expr: &'gcx Expr)
rustc_private)Check a potentially overloaded binary operator.
fn check_user_unop(&self, op_str: &str, mname: &str, trait_did: Option<DefId>, ex: &'gcx Expr, operand_expr: &'gcx Expr, operand_ty: Ty<'tcx>, op: UnOp) -> Ty<'tcx>
fn param_env(&self) -> &ParameterEnvironment<'tcx>
fn sess(&self) -> &Session
fn err_count_since_creation(&self) -> usize
fn tag(&self) -> String
fn local_ty(&self, span: Span, nid: NodeId) -> Ty<'tcx>
fn write_ty(&self, node_id: NodeId, ty: Ty<'tcx>)
fn write_substs(&self, node_id: NodeId, substs: ItemSubsts<'tcx>)
fn write_autoderef_adjustment(&self, node_id: NodeId, derefs: usize)
fn write_adjustment(&self, node_id: NodeId, adj: AutoAdjustment<'tcx>)
fn instantiate_type(&self, did: DefId, path: &Path) -> Ty<'tcx>
rustc_private)Instantiates the type in did with the generics in path and returns
it (registering the necessary trait obligations along the way).
Note that this function is only intended to be used with type-paths, not with value-paths.
fn def_struct_variant(&self, def: Def, _span: Span) -> Option<(AdtDef<'tcx>, VariantDef<'tcx>)>
rustc_private)Return the dict-like variant corresponding to a given Def.
fn write_nil(&self, node_id: NodeId)
fn write_error(&self, node_id: NodeId)
fn require_type_meets(&self, ty: Ty<'tcx>, span: Span, code: ObligationCauseCode<'tcx>, bound: BuiltinBound)
fn require_type_is_sized(&self, ty: Ty<'tcx>, span: Span, code: ObligationCauseCode<'tcx>)
fn require_expr_have_sized_type(&self, expr: &Expr, code: ObligationCauseCode<'tcx>)
fn register_builtin_bound(&self, ty: Ty<'tcx>, builtin_bound: BuiltinBound, cause: ObligationCause<'tcx>)
fn register_predicate(&self, obligation: PredicateObligation<'tcx>)
fn to_ty(&self, ast_t: &Ty) -> Ty<'tcx>
fn expr_ty(&self, ex: &Expr) -> Ty<'tcx>
fn adjust_expr_ty(&self, expr: &Expr, adjustment: Option<&AutoAdjustment<'tcx>>) -> Ty<'tcx>
rustc_private)Apply adjustment to the type of expr
fn node_ty(&self, id: NodeId) -> Ty<'tcx>
fn item_substs(&self) -> Ref<NodeMap<ItemSubsts<'tcx>>>
fn opt_node_ty_substs<F>(&self, id: NodeId, f: F) where F: FnOnce(&ItemSubsts<'tcx>)
fn register_region_obligation(&self, ty: Ty<'tcx>, region: Region, cause: ObligationCause<'tcx>)
rustc_private)Registers an obligation for checking later, during regionck, that the type ty must
outlive the region r.
fn register_wf_obligation(&self, ty: Ty<'tcx>, span: Span, code: ObligationCauseCode<'tcx>)
rustc_private)Registers an obligation for checking later, during regionck, that the type ty must
outlive the region r.
fn register_old_wf_obligation(&self, ty: Ty<'tcx>, span: Span, code: ObligationCauseCode<'tcx>)
fn add_wf_bounds(&self, substs: &Substs<'tcx>, expr: &Expr)
rustc_private)Registers obligations that all types appearing in substs are well-formed.
fn add_obligations_for_parameters(&self, cause: ObligationCause<'tcx>, predicates: &InstantiatedPredicates<'tcx>)
rustc_private)Given a fully substituted set of bounds (generic_bounds), and the values with which each
type/region parameter was instantiated (substs), creates and registers suitable
trait/region obligations.
For example, if there is a function:
fn foo<'a,T:'a>(...)
and a reference:
let f = foo;
Then we will create a fresh region variable '$0 and a fresh type variable $1 for 'a
and T. This routine will add a region obligation $1:'$0 and register it locally.
fn field_ty(&self, span: Span, field: FieldDef<'tcx>, substs: &Substs<'tcx>) -> Ty<'tcx>
fn autoderef<'b, E, I, T, F>(&self, sp: Span, base_ty: Ty<'tcx>, maybe_exprs: E, unresolved_type_action: UnresolvedTypeAction, lvalue_pref: LvaluePreference, should_stop: F) -> (Ty<'tcx>, usize, Option<T>) where E: Fn() -> I, I: IntoIterator<Item=&'b Expr>, F: FnMut(Ty<'tcx>, usize) -> Option<T>
rustc_private)Executes an autoderef loop for the type t. At each step, invokes should_stop
to decide whether to terminate the loop. Returns the final type and number of
derefs that it performed.
Note: this method does not modify the adjustments table. The caller is responsible for
inserting an AutoAdjustment record into the self using one of the suitable methods.
fn check_expr_has_type(&self, expr: &'gcx Expr, expected: Ty<'tcx>)
fn impl_self_ty(&self, span: Span, did: DefId) -> TypeAndSubsts<'tcx>
fn resolve_ty_and_def_ufcs<'b>(&self, path_res: PathResolution, opt_self_ty: Option<Ty<'tcx>>, path: &'b Path, span: Span, node_id: NodeId) -> Option<(Option<Ty<'tcx>>, &'b [PathSegment], Def)>
fn check_decl_initializer(&self, local: &'gcx Local, init: &'gcx Expr)
fn check_decl_local(&self, local: &'gcx Local)
fn check_stmt(&self, stmt: &'gcx Stmt)
fn check_block_no_value(&self, blk: &'gcx Block)
fn instantiate_path(&self, segments: &[PathSegment], type_scheme: TypeScheme<'tcx>, type_predicates: &GenericPredicates<'tcx>, opt_self_ty: Option<Ty<'tcx>>, def: Def, span: Span, node_id: NodeId)
fn structurally_resolved_type(&self, sp: Span, ty: Ty<'tcx>) -> Ty<'tcx>
Trait Implementations
impl<'a, 'gcx, 'tcx> Deref for RegionCtxt<'a, 'gcx, 'tcx>[src]
type Target = FnCtxt<'a, 'gcx, 'tcx>
The resulting type after dereferencing
fn deref(&self) -> &Self::Target
The method called to dereference a value
impl<'a, 'gcx, 'tcx, 'v> Visitor<'v> for RegionCtxt<'a, 'gcx, 'tcx>[src]
fn visit_fn(&mut self, _fk: FnKind<'v>, fd: &'v FnDecl, b: &'v Block, span: Span, id: NodeId)
fn visit_arm(&mut self, arm: &Arm)
fn visit_local(&mut self, l: &Local)
fn visit_expr(&mut self, expr: &Expr)
fn visit_nested_item(&mut self, id: ItemId)
Invoked when a nested item is encountered. By default, does nothing. If you want a deep walk, you need to override to fetch the item contents. But most of the time, it is easier (and better) to invoke Crate::visit_all_items, which visits all items in the crate in some order (but doesn't respect nesting). Read more
fn visit_item(&mut self, i: &'v Item)
Visit the top-level item and (optionally) nested items. See visit_nested_item for details. Read more