rustc_typeck to rustc_hir_analysis
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lcnr
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140 changed files with 101 additions and 102 deletions
971
compiler/rustc_hir_analysis/src/check/mod.rs
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971
compiler/rustc_hir_analysis/src/check/mod.rs
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/*!
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# typeck: check phase
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Within the check phase of type check, we check each item one at a time
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(bodies of function expressions are checked as part of the containing
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function). Inference is used to supply types wherever they are unknown.
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By far the most complex case is checking the body of a function. This
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can be broken down into several distinct phases:
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- gather: creates type variables to represent the type of each local
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variable and pattern binding.
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- main: the main pass does the lion's share of the work: it
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determines the types of all expressions, resolves
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methods, checks for most invalid conditions, and so forth. In
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some cases, where a type is unknown, it may create a type or region
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variable and use that as the type of an expression.
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In the process of checking, various constraints will be placed on
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these type variables through the subtyping relationships requested
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through the `demand` module. The `infer` module is in charge
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of resolving those constraints.
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- regionck: after main is complete, the regionck pass goes over all
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types looking for regions and making sure that they did not escape
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into places where they are not in scope. This may also influence the
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final assignments of the various region variables if there is some
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flexibility.
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- writeback: writes the final types within a function body, replacing
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type variables with their final inferred types. These final types
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are written into the `tcx.node_types` table, which should *never* contain
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any reference to a type variable.
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## Intermediate types
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While type checking a function, the intermediate types for the
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expressions, blocks, and so forth contained within the function are
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stored in `fcx.node_types` and `fcx.node_substs`. These types
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may contain unresolved type variables. After type checking is
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complete, the functions in the writeback module are used to take the
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types from this table, resolve them, and then write them into their
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permanent home in the type context `tcx`.
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This means that during inferencing you should use `fcx.write_ty()`
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and `fcx.expr_ty()` / `fcx.node_ty()` to write/obtain the types of
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nodes within the function.
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The types of top-level items, which never contain unbound type
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variables, are stored directly into the `tcx` typeck_results.
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N.B., a type variable is not the same thing as a type parameter. A
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type variable is an instance of a type parameter. That is,
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given a generic function `fn foo<T>(t: T)`, while checking the
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function `foo`, the type `ty_param(0)` refers to the type `T`, which
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is treated in abstract. However, when `foo()` is called, `T` will be
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substituted for a fresh type variable `N`. This variable will
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eventually be resolved to some concrete type (which might itself be
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a type parameter).
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*/
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pub mod _match;
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mod autoderef;
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mod callee;
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pub mod cast;
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mod check;
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mod closure;
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pub mod coercion;
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mod compare_method;
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pub mod demand;
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mod diverges;
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pub mod dropck;
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mod expectation;
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mod expr;
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mod fallback;
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mod fn_ctxt;
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mod gather_locals;
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mod generator_interior;
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mod inherited;
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pub mod intrinsic;
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mod intrinsicck;
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pub mod method;
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mod op;
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mod pat;
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mod place_op;
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mod region;
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pub mod rvalue_scopes;
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mod upvar;
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pub mod wfcheck;
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pub mod writeback;
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use check::{check_abi, check_fn, check_mod_item_types};
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pub use diverges::Diverges;
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pub use expectation::Expectation;
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pub use fn_ctxt::*;
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pub use inherited::{Inherited, InheritedBuilder};
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use crate::astconv::AstConv;
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use crate::check::gather_locals::GatherLocalsVisitor;
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use rustc_data_structures::fx::{FxHashMap, FxHashSet};
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use rustc_errors::{
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pluralize, struct_span_err, Applicability, Diagnostic, DiagnosticBuilder, MultiSpan,
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};
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use rustc_hir as hir;
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use rustc_hir::def::Res;
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use rustc_hir::def_id::{DefId, LocalDefId};
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use rustc_hir::intravisit::Visitor;
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use rustc_hir::{HirIdMap, ImplicitSelfKind, Node};
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use rustc_index::bit_set::BitSet;
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use rustc_infer::infer::type_variable::{TypeVariableOrigin, TypeVariableOriginKind};
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use rustc_middle::ty::query::Providers;
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use rustc_middle::ty::{self, Ty, TyCtxt, UserType};
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use rustc_middle::ty::{InternalSubsts, SubstsRef};
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use rustc_session::config;
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use rustc_session::parse::feature_err;
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use rustc_session::Session;
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use rustc_span::source_map::DUMMY_SP;
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use rustc_span::symbol::{kw, Ident};
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use rustc_span::{self, BytePos, Span, Symbol};
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use rustc_target::abi::VariantIdx;
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use rustc_target::spec::abi::Abi;
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use rustc_trait_selection::traits;
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use rustc_trait_selection::traits::error_reporting::recursive_type_with_infinite_size_error;
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use rustc_trait_selection::traits::error_reporting::suggestions::ReturnsVisitor;
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use std::cell::RefCell;
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use std::num::NonZeroU32;
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use crate::require_c_abi_if_c_variadic;
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use crate::util::common::indenter;
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use self::coercion::DynamicCoerceMany;
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use self::compare_method::collect_trait_impl_trait_tys;
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use self::region::region_scope_tree;
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pub use self::Expectation::*;
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#[macro_export]
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macro_rules! type_error_struct {
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($session:expr, $span:expr, $typ:expr, $code:ident, $($message:tt)*) => ({
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let mut err = rustc_errors::struct_span_err!($session, $span, $code, $($message)*);
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if $typ.references_error() {
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err.downgrade_to_delayed_bug();
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}
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err
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})
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}
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/// The type of a local binding, including the revealed type for anon types.
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#[derive(Copy, Clone, Debug)]
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pub struct LocalTy<'tcx> {
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decl_ty: Ty<'tcx>,
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revealed_ty: Ty<'tcx>,
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}
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#[derive(Copy, Clone, Debug, PartialEq, Eq)]
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pub enum Needs {
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MutPlace,
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None,
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}
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impl Needs {
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fn maybe_mut_place(m: hir::Mutability) -> Self {
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match m {
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hir::Mutability::Mut => Needs::MutPlace,
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hir::Mutability::Not => Needs::None,
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}
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}
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}
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#[derive(Copy, Clone)]
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pub struct UnsafetyState {
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pub def: hir::HirId,
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pub unsafety: hir::Unsafety,
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from_fn: bool,
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}
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impl UnsafetyState {
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pub fn function(unsafety: hir::Unsafety, def: hir::HirId) -> UnsafetyState {
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UnsafetyState { def, unsafety, from_fn: true }
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}
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pub fn recurse(self, blk: &hir::Block<'_>) -> UnsafetyState {
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use hir::BlockCheckMode;
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match self.unsafety {
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// If this unsafe, then if the outer function was already marked as
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// unsafe we shouldn't attribute the unsafe'ness to the block. This
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// way the block can be warned about instead of ignoring this
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// extraneous block (functions are never warned about).
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hir::Unsafety::Unsafe if self.from_fn => self,
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unsafety => {
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let (unsafety, def) = match blk.rules {
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BlockCheckMode::UnsafeBlock(..) => (hir::Unsafety::Unsafe, blk.hir_id),
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BlockCheckMode::DefaultBlock => (unsafety, self.def),
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};
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UnsafetyState { def, unsafety, from_fn: false }
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}
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}
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}
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}
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#[derive(Debug, Copy, Clone)]
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pub enum PlaceOp {
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Deref,
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Index,
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}
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pub struct BreakableCtxt<'tcx> {
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may_break: bool,
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// this is `null` for loops where break with a value is illegal,
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// such as `while`, `for`, and `while let`
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coerce: Option<DynamicCoerceMany<'tcx>>,
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}
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pub struct EnclosingBreakables<'tcx> {
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stack: Vec<BreakableCtxt<'tcx>>,
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by_id: HirIdMap<usize>,
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}
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impl<'tcx> EnclosingBreakables<'tcx> {
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fn find_breakable(&mut self, target_id: hir::HirId) -> &mut BreakableCtxt<'tcx> {
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self.opt_find_breakable(target_id).unwrap_or_else(|| {
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bug!("could not find enclosing breakable with id {}", target_id);
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})
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}
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fn opt_find_breakable(&mut self, target_id: hir::HirId) -> Option<&mut BreakableCtxt<'tcx>> {
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match self.by_id.get(&target_id) {
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Some(ix) => Some(&mut self.stack[*ix]),
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None => None,
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}
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}
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}
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pub fn provide(providers: &mut Providers) {
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method::provide(providers);
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wfcheck::provide(providers);
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*providers = Providers {
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typeck_item_bodies,
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typeck_const_arg,
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typeck,
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diagnostic_only_typeck,
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has_typeck_results,
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adt_destructor,
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used_trait_imports,
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check_mod_item_types,
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region_scope_tree,
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collect_trait_impl_trait_tys,
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..*providers
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};
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}
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fn adt_destructor(tcx: TyCtxt<'_>, def_id: DefId) -> Option<ty::Destructor> {
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tcx.calculate_dtor(def_id, dropck::check_drop_impl)
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}
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/// If this `DefId` is a "primary tables entry", returns
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/// `Some((body_id, body_ty, fn_sig))`. Otherwise, returns `None`.
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///
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/// If this function returns `Some`, then `typeck_results(def_id)` will
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/// succeed; if it returns `None`, then `typeck_results(def_id)` may or
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/// may not succeed. In some cases where this function returns `None`
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/// (notably closures), `typeck_results(def_id)` would wind up
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/// redirecting to the owning function.
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fn primary_body_of(
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tcx: TyCtxt<'_>,
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id: hir::HirId,
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) -> Option<(hir::BodyId, Option<&hir::Ty<'_>>, Option<&hir::FnSig<'_>>)> {
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match tcx.hir().get(id) {
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Node::Item(item) => match item.kind {
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hir::ItemKind::Const(ty, body) | hir::ItemKind::Static(ty, _, body) => {
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Some((body, Some(ty), None))
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}
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hir::ItemKind::Fn(ref sig, .., body) => Some((body, None, Some(sig))),
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_ => None,
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},
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Node::TraitItem(item) => match item.kind {
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hir::TraitItemKind::Const(ty, Some(body)) => Some((body, Some(ty), None)),
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hir::TraitItemKind::Fn(ref sig, hir::TraitFn::Provided(body)) => {
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Some((body, None, Some(sig)))
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}
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_ => None,
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},
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Node::ImplItem(item) => match item.kind {
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hir::ImplItemKind::Const(ty, body) => Some((body, Some(ty), None)),
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hir::ImplItemKind::Fn(ref sig, body) => Some((body, None, Some(sig))),
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_ => None,
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},
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Node::AnonConst(constant) => Some((constant.body, None, None)),
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_ => None,
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}
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}
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fn has_typeck_results(tcx: TyCtxt<'_>, def_id: DefId) -> bool {
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// Closures' typeck results come from their outermost function,
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// as they are part of the same "inference environment".
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let typeck_root_def_id = tcx.typeck_root_def_id(def_id);
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if typeck_root_def_id != def_id {
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return tcx.has_typeck_results(typeck_root_def_id);
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}
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if let Some(def_id) = def_id.as_local() {
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let id = tcx.hir().local_def_id_to_hir_id(def_id);
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primary_body_of(tcx, id).is_some()
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} else {
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false
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}
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}
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fn used_trait_imports(tcx: TyCtxt<'_>, def_id: LocalDefId) -> &FxHashSet<LocalDefId> {
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&*tcx.typeck(def_id).used_trait_imports
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}
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fn typeck_const_arg<'tcx>(
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tcx: TyCtxt<'tcx>,
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(did, param_did): (LocalDefId, DefId),
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) -> &ty::TypeckResults<'tcx> {
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let fallback = move || tcx.type_of(param_did);
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typeck_with_fallback(tcx, did, fallback)
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}
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fn typeck<'tcx>(tcx: TyCtxt<'tcx>, def_id: LocalDefId) -> &ty::TypeckResults<'tcx> {
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if let Some(param_did) = tcx.opt_const_param_of(def_id) {
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tcx.typeck_const_arg((def_id, param_did))
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} else {
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let fallback = move || tcx.type_of(def_id.to_def_id());
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typeck_with_fallback(tcx, def_id, fallback)
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}
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}
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/// Used only to get `TypeckResults` for type inference during error recovery.
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/// Currently only used for type inference of `static`s and `const`s to avoid type cycle errors.
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fn diagnostic_only_typeck<'tcx>(tcx: TyCtxt<'tcx>, def_id: LocalDefId) -> &ty::TypeckResults<'tcx> {
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let fallback = move || {
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let span = tcx.hir().span(tcx.hir().local_def_id_to_hir_id(def_id));
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tcx.ty_error_with_message(span, "diagnostic only typeck table used")
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};
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typeck_with_fallback(tcx, def_id, fallback)
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}
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fn typeck_with_fallback<'tcx>(
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tcx: TyCtxt<'tcx>,
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def_id: LocalDefId,
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fallback: impl Fn() -> Ty<'tcx> + 'tcx,
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) -> &'tcx ty::TypeckResults<'tcx> {
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// Closures' typeck results come from their outermost function,
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// as they are part of the same "inference environment".
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let typeck_root_def_id = tcx.typeck_root_def_id(def_id.to_def_id()).expect_local();
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if typeck_root_def_id != def_id {
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return tcx.typeck(typeck_root_def_id);
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}
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let id = tcx.hir().local_def_id_to_hir_id(def_id);
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let span = tcx.hir().span(id);
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// Figure out what primary body this item has.
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let (body_id, body_ty, fn_sig) = primary_body_of(tcx, id).unwrap_or_else(|| {
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span_bug!(span, "can't type-check body of {:?}", def_id);
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});
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let body = tcx.hir().body(body_id);
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let typeck_results = Inherited::build(tcx, def_id).enter(|inh| {
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let param_env = tcx.param_env(def_id);
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let mut fcx = if let Some(hir::FnSig { header, decl, .. }) = fn_sig {
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let fn_sig = if crate::collect::get_infer_ret_ty(&decl.output).is_some() {
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let fcx = FnCtxt::new(&inh, param_env, body.value.hir_id);
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<dyn AstConv<'_>>::ty_of_fn(&fcx, id, header.unsafety, header.abi, decl, None, None)
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} else {
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tcx.fn_sig(def_id)
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};
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check_abi(tcx, id, span, fn_sig.abi());
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// Compute the function signature from point of view of inside the fn.
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let fn_sig = tcx.liberate_late_bound_regions(def_id.to_def_id(), fn_sig);
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let fn_sig = inh.normalize_associated_types_in(
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body.value.span,
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body_id.hir_id,
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param_env,
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fn_sig,
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);
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check_fn(&inh, param_env, fn_sig, decl, id, body, None, true).0
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} else {
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let fcx = FnCtxt::new(&inh, param_env, body.value.hir_id);
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let expected_type = body_ty
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.and_then(|ty| match ty.kind {
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hir::TyKind::Infer => Some(<dyn AstConv<'_>>::ast_ty_to_ty(&fcx, ty)),
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_ => None,
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})
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.unwrap_or_else(|| match tcx.hir().get(id) {
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Node::AnonConst(_) => match tcx.hir().get(tcx.hir().get_parent_node(id)) {
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Node::Expr(&hir::Expr {
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kind: hir::ExprKind::ConstBlock(ref anon_const),
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..
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}) if anon_const.hir_id == id => fcx.next_ty_var(TypeVariableOrigin {
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kind: TypeVariableOriginKind::TypeInference,
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span,
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}),
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Node::Ty(&hir::Ty {
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kind: hir::TyKind::Typeof(ref anon_const), ..
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}) if anon_const.hir_id == id => fcx.next_ty_var(TypeVariableOrigin {
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kind: TypeVariableOriginKind::TypeInference,
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span,
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}),
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Node::Expr(&hir::Expr { kind: hir::ExprKind::InlineAsm(asm), .. })
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| Node::Item(&hir::Item { kind: hir::ItemKind::GlobalAsm(asm), .. }) => {
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let operand_ty = asm
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.operands
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.iter()
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.filter_map(|(op, _op_sp)| match op {
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hir::InlineAsmOperand::Const { anon_const }
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if anon_const.hir_id == id =>
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{
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// Inline assembly constants must be integers.
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Some(fcx.next_int_var())
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}
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hir::InlineAsmOperand::SymFn { anon_const }
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if anon_const.hir_id == id =>
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{
|
||||
Some(fcx.next_ty_var(TypeVariableOrigin {
|
||||
kind: TypeVariableOriginKind::MiscVariable,
|
||||
span,
|
||||
}))
|
||||
}
|
||||
_ => None,
|
||||
})
|
||||
.next();
|
||||
operand_ty.unwrap_or_else(fallback)
|
||||
}
|
||||
_ => fallback(),
|
||||
},
|
||||
_ => fallback(),
|
||||
});
|
||||
|
||||
let expected_type = fcx.normalize_associated_types_in(body.value.span, expected_type);
|
||||
fcx.require_type_is_sized(expected_type, body.value.span, traits::ConstSized);
|
||||
|
||||
// Gather locals in statics (because of block expressions).
|
||||
GatherLocalsVisitor::new(&fcx).visit_body(body);
|
||||
|
||||
fcx.check_expr_coercable_to_type(&body.value, expected_type, None);
|
||||
|
||||
fcx.write_ty(id, expected_type);
|
||||
|
||||
fcx
|
||||
};
|
||||
|
||||
let fallback_has_occurred = fcx.type_inference_fallback();
|
||||
|
||||
// Even though coercion casts provide type hints, we check casts after fallback for
|
||||
// backwards compatibility. This makes fallback a stronger type hint than a cast coercion.
|
||||
fcx.check_casts();
|
||||
fcx.select_obligations_where_possible(fallback_has_occurred, |_| {});
|
||||
|
||||
// Closure and generator analysis may run after fallback
|
||||
// because they don't constrain other type variables.
|
||||
// Closure analysis only runs on closures. Therefore they only need to fulfill non-const predicates (as of now)
|
||||
let prev_constness = fcx.param_env.constness();
|
||||
fcx.param_env = fcx.param_env.without_const();
|
||||
fcx.closure_analyze(body);
|
||||
fcx.param_env = fcx.param_env.with_constness(prev_constness);
|
||||
assert!(fcx.deferred_call_resolutions.borrow().is_empty());
|
||||
// Before the generator analysis, temporary scopes shall be marked to provide more
|
||||
// precise information on types to be captured.
|
||||
fcx.resolve_rvalue_scopes(def_id.to_def_id());
|
||||
fcx.resolve_generator_interiors(def_id.to_def_id());
|
||||
|
||||
for (ty, span, code) in fcx.deferred_sized_obligations.borrow_mut().drain(..) {
|
||||
let ty = fcx.normalize_ty(span, ty);
|
||||
fcx.require_type_is_sized(ty, span, code);
|
||||
}
|
||||
|
||||
fcx.select_all_obligations_or_error();
|
||||
|
||||
if !fcx.infcx.is_tainted_by_errors() {
|
||||
fcx.check_transmutes();
|
||||
}
|
||||
|
||||
fcx.check_asms();
|
||||
|
||||
fcx.infcx.skip_region_resolution();
|
||||
|
||||
fcx.resolve_type_vars_in_body(body)
|
||||
});
|
||||
|
||||
// Consistency check our TypeckResults instance can hold all ItemLocalIds
|
||||
// it will need to hold.
|
||||
assert_eq!(typeck_results.hir_owner, id.owner);
|
||||
|
||||
typeck_results
|
||||
}
|
||||
|
||||
/// When `check_fn` is invoked on a generator (i.e., a body that
|
||||
/// includes yield), it returns back some information about the yield
|
||||
/// points.
|
||||
struct GeneratorTypes<'tcx> {
|
||||
/// Type of generator argument / values returned by `yield`.
|
||||
resume_ty: Ty<'tcx>,
|
||||
|
||||
/// Type of value that is yielded.
|
||||
yield_ty: Ty<'tcx>,
|
||||
|
||||
/// Types that are captured (see `GeneratorInterior` for more).
|
||||
interior: Ty<'tcx>,
|
||||
|
||||
/// Indicates if the generator is movable or static (immovable).
|
||||
movability: hir::Movability,
|
||||
}
|
||||
|
||||
/// Given a `DefId` for an opaque type in return position, find its parent item's return
|
||||
/// expressions.
|
||||
fn get_owner_return_paths<'tcx>(
|
||||
tcx: TyCtxt<'tcx>,
|
||||
def_id: LocalDefId,
|
||||
) -> Option<(LocalDefId, ReturnsVisitor<'tcx>)> {
|
||||
let hir_id = tcx.hir().local_def_id_to_hir_id(def_id);
|
||||
let parent_id = tcx.hir().get_parent_item(hir_id).def_id;
|
||||
tcx.hir().find_by_def_id(parent_id).and_then(|node| node.body_id()).map(|body_id| {
|
||||
let body = tcx.hir().body(body_id);
|
||||
let mut visitor = ReturnsVisitor::default();
|
||||
visitor.visit_body(body);
|
||||
(parent_id, visitor)
|
||||
})
|
||||
}
|
||||
|
||||
// Forbid defining intrinsics in Rust code,
|
||||
// as they must always be defined by the compiler.
|
||||
fn fn_maybe_err(tcx: TyCtxt<'_>, sp: Span, abi: Abi) {
|
||||
if let Abi::RustIntrinsic | Abi::PlatformIntrinsic = abi {
|
||||
tcx.sess.span_err(sp, "intrinsic must be in `extern \"rust-intrinsic\" { ... }` block");
|
||||
}
|
||||
}
|
||||
|
||||
fn maybe_check_static_with_link_section(tcx: TyCtxt<'_>, id: LocalDefId) {
|
||||
// Only restricted on wasm target for now
|
||||
if !tcx.sess.target.is_like_wasm {
|
||||
return;
|
||||
}
|
||||
|
||||
// If `#[link_section]` is missing, then nothing to verify
|
||||
let attrs = tcx.codegen_fn_attrs(id);
|
||||
if attrs.link_section.is_none() {
|
||||
return;
|
||||
}
|
||||
|
||||
// For the wasm32 target statics with `#[link_section]` are placed into custom
|
||||
// sections of the final output file, but this isn't link custom sections of
|
||||
// other executable formats. Namely we can only embed a list of bytes,
|
||||
// nothing with provenance (pointers to anything else). If any provenance
|
||||
// show up, reject it here.
|
||||
// `#[link_section]` may contain arbitrary, or even undefined bytes, but it is
|
||||
// the consumer's responsibility to ensure all bytes that have been read
|
||||
// have defined values.
|
||||
if let Ok(alloc) = tcx.eval_static_initializer(id.to_def_id())
|
||||
&& alloc.inner().provenance().len() != 0
|
||||
{
|
||||
let msg = "statics with a custom `#[link_section]` must be a \
|
||||
simple list of bytes on the wasm target with no \
|
||||
extra levels of indirection such as references";
|
||||
tcx.sess.span_err(tcx.def_span(id), msg);
|
||||
}
|
||||
}
|
||||
|
||||
fn report_forbidden_specialization(
|
||||
tcx: TyCtxt<'_>,
|
||||
impl_item: &hir::ImplItemRef,
|
||||
parent_impl: DefId,
|
||||
) {
|
||||
let mut err = struct_span_err!(
|
||||
tcx.sess,
|
||||
impl_item.span,
|
||||
E0520,
|
||||
"`{}` specializes an item from a parent `impl`, but \
|
||||
that item is not marked `default`",
|
||||
impl_item.ident
|
||||
);
|
||||
err.span_label(impl_item.span, format!("cannot specialize default item `{}`", impl_item.ident));
|
||||
|
||||
match tcx.span_of_impl(parent_impl) {
|
||||
Ok(span) => {
|
||||
err.span_label(span, "parent `impl` is here");
|
||||
err.note(&format!(
|
||||
"to specialize, `{}` in the parent `impl` must be marked `default`",
|
||||
impl_item.ident
|
||||
));
|
||||
}
|
||||
Err(cname) => {
|
||||
err.note(&format!("parent implementation is in crate `{cname}`"));
|
||||
}
|
||||
}
|
||||
|
||||
err.emit();
|
||||
}
|
||||
|
||||
fn missing_items_err(
|
||||
tcx: TyCtxt<'_>,
|
||||
impl_span: Span,
|
||||
missing_items: &[&ty::AssocItem],
|
||||
full_impl_span: Span,
|
||||
) {
|
||||
let missing_items_msg = missing_items
|
||||
.iter()
|
||||
.map(|trait_item| trait_item.name.to_string())
|
||||
.collect::<Vec<_>>()
|
||||
.join("`, `");
|
||||
|
||||
let mut err = struct_span_err!(
|
||||
tcx.sess,
|
||||
impl_span,
|
||||
E0046,
|
||||
"not all trait items implemented, missing: `{missing_items_msg}`",
|
||||
);
|
||||
err.span_label(impl_span, format!("missing `{missing_items_msg}` in implementation"));
|
||||
|
||||
// `Span` before impl block closing brace.
|
||||
let hi = full_impl_span.hi() - BytePos(1);
|
||||
// Point at the place right before the closing brace of the relevant `impl` to suggest
|
||||
// adding the associated item at the end of its body.
|
||||
let sugg_sp = full_impl_span.with_lo(hi).with_hi(hi);
|
||||
// Obtain the level of indentation ending in `sugg_sp`.
|
||||
let padding =
|
||||
tcx.sess.source_map().indentation_before(sugg_sp).unwrap_or_else(|| String::new());
|
||||
|
||||
for trait_item in missing_items {
|
||||
let snippet = suggestion_signature(trait_item, tcx);
|
||||
let code = format!("{}{}\n{}", padding, snippet, padding);
|
||||
let msg = format!("implement the missing item: `{snippet}`");
|
||||
let appl = Applicability::HasPlaceholders;
|
||||
if let Some(span) = tcx.hir().span_if_local(trait_item.def_id) {
|
||||
err.span_label(span, format!("`{}` from trait", trait_item.name));
|
||||
err.tool_only_span_suggestion(sugg_sp, &msg, code, appl);
|
||||
} else {
|
||||
err.span_suggestion_hidden(sugg_sp, &msg, code, appl);
|
||||
}
|
||||
}
|
||||
err.emit();
|
||||
}
|
||||
|
||||
fn missing_items_must_implement_one_of_err(
|
||||
tcx: TyCtxt<'_>,
|
||||
impl_span: Span,
|
||||
missing_items: &[Ident],
|
||||
annotation_span: Option<Span>,
|
||||
) {
|
||||
let missing_items_msg =
|
||||
missing_items.iter().map(Ident::to_string).collect::<Vec<_>>().join("`, `");
|
||||
|
||||
let mut err = struct_span_err!(
|
||||
tcx.sess,
|
||||
impl_span,
|
||||
E0046,
|
||||
"not all trait items implemented, missing one of: `{missing_items_msg}`",
|
||||
);
|
||||
err.span_label(impl_span, format!("missing one of `{missing_items_msg}` in implementation"));
|
||||
|
||||
if let Some(annotation_span) = annotation_span {
|
||||
err.span_note(annotation_span, "required because of this annotation");
|
||||
}
|
||||
|
||||
err.emit();
|
||||
}
|
||||
|
||||
fn default_body_is_unstable(
|
||||
tcx: TyCtxt<'_>,
|
||||
impl_span: Span,
|
||||
item_did: DefId,
|
||||
feature: Symbol,
|
||||
reason: Option<Symbol>,
|
||||
issue: Option<NonZeroU32>,
|
||||
) {
|
||||
let missing_item_name = &tcx.associated_item(item_did).name;
|
||||
let use_of_unstable_library_feature_note = match reason {
|
||||
Some(r) => format!("use of unstable library feature '{feature}': {r}"),
|
||||
None => format!("use of unstable library feature '{feature}'"),
|
||||
};
|
||||
|
||||
let mut err = struct_span_err!(
|
||||
tcx.sess,
|
||||
impl_span,
|
||||
E0046,
|
||||
"not all trait items implemented, missing: `{missing_item_name}`",
|
||||
);
|
||||
err.note(format!("default implementation of `{missing_item_name}` is unstable"));
|
||||
err.note(use_of_unstable_library_feature_note);
|
||||
rustc_session::parse::add_feature_diagnostics_for_issue(
|
||||
&mut err,
|
||||
&tcx.sess.parse_sess,
|
||||
feature,
|
||||
rustc_feature::GateIssue::Library(issue),
|
||||
);
|
||||
err.emit();
|
||||
}
|
||||
|
||||
/// Re-sugar `ty::GenericPredicates` in a way suitable to be used in structured suggestions.
|
||||
fn bounds_from_generic_predicates<'tcx>(
|
||||
tcx: TyCtxt<'tcx>,
|
||||
predicates: ty::GenericPredicates<'tcx>,
|
||||
) -> (String, String) {
|
||||
let mut types: FxHashMap<Ty<'tcx>, Vec<DefId>> = FxHashMap::default();
|
||||
let mut projections = vec![];
|
||||
for (predicate, _) in predicates.predicates {
|
||||
debug!("predicate {:?}", predicate);
|
||||
let bound_predicate = predicate.kind();
|
||||
match bound_predicate.skip_binder() {
|
||||
ty::PredicateKind::Trait(trait_predicate) => {
|
||||
let entry = types.entry(trait_predicate.self_ty()).or_default();
|
||||
let def_id = trait_predicate.def_id();
|
||||
if Some(def_id) != tcx.lang_items().sized_trait() {
|
||||
// Type params are `Sized` by default, do not add that restriction to the list
|
||||
// if it is a positive requirement.
|
||||
entry.push(trait_predicate.def_id());
|
||||
}
|
||||
}
|
||||
ty::PredicateKind::Projection(projection_pred) => {
|
||||
projections.push(bound_predicate.rebind(projection_pred));
|
||||
}
|
||||
_ => {}
|
||||
}
|
||||
}
|
||||
let generics = if types.is_empty() {
|
||||
"".to_string()
|
||||
} else {
|
||||
format!(
|
||||
"<{}>",
|
||||
types
|
||||
.keys()
|
||||
.filter_map(|t| match t.kind() {
|
||||
ty::Param(_) => Some(t.to_string()),
|
||||
// Avoid suggesting the following:
|
||||
// fn foo<T, <T as Trait>::Bar>(_: T) where T: Trait, <T as Trait>::Bar: Other {}
|
||||
_ => None,
|
||||
})
|
||||
.collect::<Vec<_>>()
|
||||
.join(", ")
|
||||
)
|
||||
};
|
||||
let mut where_clauses = vec![];
|
||||
for (ty, bounds) in types {
|
||||
where_clauses
|
||||
.extend(bounds.into_iter().map(|bound| format!("{}: {}", ty, tcx.def_path_str(bound))));
|
||||
}
|
||||
for projection in &projections {
|
||||
let p = projection.skip_binder();
|
||||
// FIXME: this is not currently supported syntax, we should be looking at the `types` and
|
||||
// insert the associated types where they correspond, but for now let's be "lazy" and
|
||||
// propose this instead of the following valid resugaring:
|
||||
// `T: Trait, Trait::Assoc = K` → `T: Trait<Assoc = K>`
|
||||
where_clauses.push(format!(
|
||||
"{} = {}",
|
||||
tcx.def_path_str(p.projection_ty.item_def_id),
|
||||
p.term,
|
||||
));
|
||||
}
|
||||
let where_clauses = if where_clauses.is_empty() {
|
||||
String::new()
|
||||
} else {
|
||||
format!(" where {}", where_clauses.join(", "))
|
||||
};
|
||||
(generics, where_clauses)
|
||||
}
|
||||
|
||||
/// Return placeholder code for the given function.
|
||||
fn fn_sig_suggestion<'tcx>(
|
||||
tcx: TyCtxt<'tcx>,
|
||||
sig: ty::FnSig<'tcx>,
|
||||
ident: Ident,
|
||||
predicates: ty::GenericPredicates<'tcx>,
|
||||
assoc: &ty::AssocItem,
|
||||
) -> String {
|
||||
let args = sig
|
||||
.inputs()
|
||||
.iter()
|
||||
.enumerate()
|
||||
.map(|(i, ty)| {
|
||||
Some(match ty.kind() {
|
||||
ty::Param(_) if assoc.fn_has_self_parameter && i == 0 => "self".to_string(),
|
||||
ty::Ref(reg, ref_ty, mutability) if i == 0 => {
|
||||
let reg = format!("{reg} ");
|
||||
let reg = match ®[..] {
|
||||
"'_ " | " " => "",
|
||||
reg => reg,
|
||||
};
|
||||
if assoc.fn_has_self_parameter {
|
||||
match ref_ty.kind() {
|
||||
ty::Param(param) if param.name == kw::SelfUpper => {
|
||||
format!("&{}{}self", reg, mutability.prefix_str())
|
||||
}
|
||||
|
||||
_ => format!("self: {ty}"),
|
||||
}
|
||||
} else {
|
||||
format!("_: {ty}")
|
||||
}
|
||||
}
|
||||
_ => {
|
||||
if assoc.fn_has_self_parameter && i == 0 {
|
||||
format!("self: {ty}")
|
||||
} else {
|
||||
format!("_: {ty}")
|
||||
}
|
||||
}
|
||||
})
|
||||
})
|
||||
.chain(std::iter::once(if sig.c_variadic { Some("...".to_string()) } else { None }))
|
||||
.flatten()
|
||||
.collect::<Vec<String>>()
|
||||
.join(", ");
|
||||
let output = sig.output();
|
||||
let output = if !output.is_unit() { format!(" -> {output}") } else { String::new() };
|
||||
|
||||
let unsafety = sig.unsafety.prefix_str();
|
||||
let (generics, where_clauses) = bounds_from_generic_predicates(tcx, predicates);
|
||||
|
||||
// FIXME: this is not entirely correct, as the lifetimes from borrowed params will
|
||||
// not be present in the `fn` definition, not will we account for renamed
|
||||
// lifetimes between the `impl` and the `trait`, but this should be good enough to
|
||||
// fill in a significant portion of the missing code, and other subsequent
|
||||
// suggestions can help the user fix the code.
|
||||
format!("{unsafety}fn {ident}{generics}({args}){output}{where_clauses} {{ todo!() }}")
|
||||
}
|
||||
|
||||
/// Return placeholder code for the given associated item.
|
||||
/// Similar to `ty::AssocItem::suggestion`, but appropriate for use as the code snippet of a
|
||||
/// structured suggestion.
|
||||
fn suggestion_signature(assoc: &ty::AssocItem, tcx: TyCtxt<'_>) -> String {
|
||||
match assoc.kind {
|
||||
ty::AssocKind::Fn => {
|
||||
// We skip the binder here because the binder would deanonymize all
|
||||
// late-bound regions, and we don't want method signatures to show up
|
||||
// `as for<'r> fn(&'r MyType)`. Pretty-printing handles late-bound
|
||||
// regions just fine, showing `fn(&MyType)`.
|
||||
fn_sig_suggestion(
|
||||
tcx,
|
||||
tcx.fn_sig(assoc.def_id).skip_binder(),
|
||||
assoc.ident(tcx),
|
||||
tcx.predicates_of(assoc.def_id),
|
||||
assoc,
|
||||
)
|
||||
}
|
||||
ty::AssocKind::Type => format!("type {} = Type;", assoc.name),
|
||||
ty::AssocKind::Const => {
|
||||
let ty = tcx.type_of(assoc.def_id);
|
||||
let val = expr::ty_kind_suggestion(ty).unwrap_or("value");
|
||||
format!("const {}: {} = {};", assoc.name, ty, val)
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
/// Emit an error when encountering two or more variants in a transparent enum.
|
||||
fn bad_variant_count<'tcx>(tcx: TyCtxt<'tcx>, adt: ty::AdtDef<'tcx>, sp: Span, did: DefId) {
|
||||
let variant_spans: Vec<_> = adt
|
||||
.variants()
|
||||
.iter()
|
||||
.map(|variant| tcx.hir().span_if_local(variant.def_id).unwrap())
|
||||
.collect();
|
||||
let msg = format!("needs exactly one variant, but has {}", adt.variants().len(),);
|
||||
let mut err = struct_span_err!(tcx.sess, sp, E0731, "transparent enum {msg}");
|
||||
err.span_label(sp, &msg);
|
||||
if let [start @ .., end] = &*variant_spans {
|
||||
for variant_span in start {
|
||||
err.span_label(*variant_span, "");
|
||||
}
|
||||
err.span_label(*end, &format!("too many variants in `{}`", tcx.def_path_str(did)));
|
||||
}
|
||||
err.emit();
|
||||
}
|
||||
|
||||
/// Emit an error when encountering two or more non-zero-sized fields in a transparent
|
||||
/// enum.
|
||||
fn bad_non_zero_sized_fields<'tcx>(
|
||||
tcx: TyCtxt<'tcx>,
|
||||
adt: ty::AdtDef<'tcx>,
|
||||
field_count: usize,
|
||||
field_spans: impl Iterator<Item = Span>,
|
||||
sp: Span,
|
||||
) {
|
||||
let msg = format!("needs at most one non-zero-sized field, but has {field_count}");
|
||||
let mut err = struct_span_err!(
|
||||
tcx.sess,
|
||||
sp,
|
||||
E0690,
|
||||
"{}transparent {} {}",
|
||||
if adt.is_enum() { "the variant of a " } else { "" },
|
||||
adt.descr(),
|
||||
msg,
|
||||
);
|
||||
err.span_label(sp, &msg);
|
||||
for sp in field_spans {
|
||||
err.span_label(sp, "this field is non-zero-sized");
|
||||
}
|
||||
err.emit();
|
||||
}
|
||||
|
||||
fn report_unexpected_variant_res(tcx: TyCtxt<'_>, res: Res, qpath: &hir::QPath<'_>, span: Span) {
|
||||
struct_span_err!(
|
||||
tcx.sess,
|
||||
span,
|
||||
E0533,
|
||||
"expected unit struct, unit variant or constant, found {} `{}`",
|
||||
res.descr(),
|
||||
rustc_hir_pretty::qpath_to_string(qpath),
|
||||
)
|
||||
.emit();
|
||||
}
|
||||
|
||||
/// Controls whether the arguments are tupled. This is used for the call
|
||||
/// operator.
|
||||
///
|
||||
/// Tupling means that all call-side arguments are packed into a tuple and
|
||||
/// passed as a single parameter. For example, if tupling is enabled, this
|
||||
/// function:
|
||||
/// ```
|
||||
/// fn f(x: (isize, isize)) {}
|
||||
/// ```
|
||||
/// Can be called as:
|
||||
/// ```ignore UNSOLVED (can this be done in user code?)
|
||||
/// # fn f(x: (isize, isize)) {}
|
||||
/// f(1, 2);
|
||||
/// ```
|
||||
/// Instead of:
|
||||
/// ```
|
||||
/// # fn f(x: (isize, isize)) {}
|
||||
/// f((1, 2));
|
||||
/// ```
|
||||
#[derive(Clone, Eq, PartialEq)]
|
||||
enum TupleArgumentsFlag {
|
||||
DontTupleArguments,
|
||||
TupleArguments,
|
||||
}
|
||||
|
||||
fn typeck_item_bodies(tcx: TyCtxt<'_>, (): ()) {
|
||||
tcx.hir().par_body_owners(|body_owner_def_id| tcx.ensure().typeck(body_owner_def_id));
|
||||
}
|
||||
|
||||
fn fatally_break_rust(sess: &Session) {
|
||||
let handler = sess.diagnostic();
|
||||
handler.span_bug_no_panic(
|
||||
MultiSpan::new(),
|
||||
"It looks like you're trying to break rust; would you like some ICE?",
|
||||
);
|
||||
handler.note_without_error("the compiler expectedly panicked. this is a feature.");
|
||||
handler.note_without_error(
|
||||
"we would appreciate a joke overview: \
|
||||
https://github.com/rust-lang/rust/issues/43162#issuecomment-320764675",
|
||||
);
|
||||
handler.note_without_error(&format!(
|
||||
"rustc {} running on {}",
|
||||
option_env!("CFG_VERSION").unwrap_or("unknown_version"),
|
||||
config::host_triple(),
|
||||
));
|
||||
}
|
||||
|
||||
fn potentially_plural_count(count: usize, word: &str) -> String {
|
||||
format!("{} {}{}", count, word, pluralize!(count))
|
||||
}
|
||||
|
||||
fn has_expected_num_generic_args<'tcx>(
|
||||
tcx: TyCtxt<'tcx>,
|
||||
trait_did: Option<DefId>,
|
||||
expected: usize,
|
||||
) -> bool {
|
||||
trait_did.map_or(true, |trait_did| {
|
||||
let generics = tcx.generics_of(trait_did);
|
||||
generics.count() == expected + if generics.has_self { 1 } else { 0 }
|
||||
})
|
||||
}
|
||||
Loading…
Add table
Add a link
Reference in a new issue