bjoernager/rust
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Auto merge of #109119 - lcnr:trait-system-cleanup, r=compiler-errors

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a general type system cleanup

removes the helper functions `traits::fully_solve_X` as they add more complexity then they are worth. It's confusing which of these helpers should be used in which context.

changes the way we deal with overflow to always add depth in `evaluate_predicates_recursively`. It may make sense to actually fully transition to not have `recursion_depth` on obligations but that's probably a bit too much for this PR.

also removes some other small - and imo unnecessary - helpers.

r? types
This commit is contained in:
bors 2023-03-22 05:33:18 +00:00
commit 9bdb4881c7
39 changed files with 259 additions and 385 deletions
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1
compiler/rustc_hir_analysis/src/check/intrinsic.rs
View file

@ -59,6 +59,7 @@ fn equate_intrinsic_type<'tcx>(
require_same_types(
tcx,
&cause,
ty::ParamEnv::empty(), // FIXME: do all intrinsics have an empty param env?
tcx.mk_fn_ptr(tcx.fn_sig(it.owner_id).subst_identity()),
fty,
);

33
compiler/rustc_hir_analysis/src/coherence/builtin.rs
View file

@ -11,13 +11,14 @@ use rustc_hir::ItemKind;
use rustc_infer::infer::outlives::env::OutlivesEnvironment;
use rustc_infer::infer::{self, RegionResolutionError};
use rustc_infer::infer::{DefineOpaqueTypes, TyCtxtInferExt};
use rustc_infer::traits::Obligation;
use rustc_middle::ty::adjustment::CoerceUnsizedInfo;
use rustc_middle::ty::{self, suggest_constraining_type_params, Ty, TyCtxt, TypeVisitableExt};
use rustc_trait_selection::traits::error_reporting::TypeErrCtxtExt;
use rustc_trait_selection::traits::misc::{
type_allowed_to_implement_copy, CopyImplementationError, InfringingFieldsReason,
};
use rustc_trait_selection::traits::predicate_for_trait_def;
use rustc_trait_selection::traits::ObligationCtxt;
use rustc_trait_selection::traits::{self, ObligationCause};
use std::collections::BTreeMap;
@ -334,19 +335,19 @@ fn visit_implementation_of_dispatch_from_dyn(tcx: TyCtxt<'_>, impl_did: LocalDef
))
.emit();
} else {
let errors = traits::fully_solve_obligations(
&infcx,
coerced_fields.into_iter().map(|field| {
predicate_for_trait_def(
tcx,
param_env,
cause.clone(),
let ocx = ObligationCtxt::new(&infcx);
for field in coerced_fields {
ocx.register_obligation(Obligation::new(
tcx,
cause.clone(),
param_env,
ty::Binder::dummy(tcx.mk_trait_ref(
dispatch_from_dyn_trait,
0,
[field.ty(tcx, substs_a), field.ty(tcx, substs_b)],
)
}),
);
)),
));
}
let errors = ocx.select_all_or_error();
if !errors.is_empty() {
infcx.err_ctxt().report_fulfillment_errors(&errors);
}
@ -580,10 +581,12 @@ pub fn coerce_unsized_info<'tcx>(tcx: TyCtxt<'tcx>, impl_did: LocalDefId) -> Coe
};
// Register an obligation for `A: Trait<B>`.
let ocx = ObligationCtxt::new(&infcx);
let cause = traits::ObligationCause::misc(span, impl_did);
let predicate =
predicate_for_trait_def(tcx, param_env, cause, trait_def_id, 0, [source, target]);
let errors = traits::fully_solve_obligation(&infcx, predicate);
let obligation =
Obligation::new(tcx, cause, param_env, tcx.mk_trait_ref(trait_def_id, [source, target]));
ocx.register_obligation(obligation);
let errors = ocx.select_all_or_error();
if !errors.is_empty() {
infcx.err_ctxt().report_fulfillment_errors(&errors);
}

42
compiler/rustc_hir_analysis/src/hir_wf_check.rs
View file

@ -7,7 +7,7 @@ use rustc_infer::traits::{ObligationCause, WellFormedLoc};
use rustc_middle::ty::query::Providers;
use rustc_middle::ty::{self, Region, TyCtxt, TypeFoldable, TypeFolder};
use rustc_span::def_id::LocalDefId;
use rustc_trait_selection::traits;
use rustc_trait_selection::traits::{self, ObligationCtxt};
pub fn provide(providers: &mut Providers) {
*providers = Providers { diagnostic_hir_wf_check, ..*providers };
@ -66,35 +66,35 @@ fn diagnostic_hir_wf_check<'tcx>(
impl<'tcx> Visitor<'tcx> for HirWfCheck<'tcx> {
fn visit_ty(&mut self, ty: &'tcx hir::Ty<'tcx>) {
let infcx = self.tcx.infer_ctxt().build();
let ocx = ObligationCtxt::new(&infcx);
let tcx_ty = self.icx.to_ty(ty).fold_with(&mut EraseAllBoundRegions { tcx: self.tcx });
let cause = traits::ObligationCause::new(
ty.span,
self.def_id,
traits::ObligationCauseCode::WellFormed(None),
);
let errors = traits::fully_solve_obligation(
&infcx,
traits::Obligation::new(
self.tcx,
cause,
self.param_env,
ty::Binder::dummy(ty::PredicateKind::WellFormed(tcx_ty.into())),
),
);
if !errors.is_empty() {
debug!("Wf-check got errors for {:?}: {:?}", ty, errors);
for error in errors {
if error.obligation.predicate == self.predicate {
// Save the cause from the greatest depth - this corresponds
// to picking more-specific types (e.g. `MyStruct<u8>`)
// over less-specific types (e.g. `Option<MyStruct<u8>>`)
if self.depth >= self.cause_depth {
self.cause = Some(error.obligation.cause);
self.cause_depth = self.depth
}
ocx.register_obligation(traits::Obligation::new(
self.tcx,
cause,
self.param_env,
ty::PredicateKind::WellFormed(tcx_ty.into()),
));
for error in ocx.select_all_or_error() {
debug!("Wf-check got error for {:?}: {:?}", ty, error);
if error.obligation.predicate == self.predicate {
// Save the cause from the greatest depth - this corresponds
// to picking more-specific types (e.g. `MyStruct<u8>`)
// over less-specific types (e.g. `Option<MyStruct<u8>>`)
if self.depth >= self.cause_depth {
self.cause = Some(error.obligation.cause);
self.cause_depth = self.depth
}
}
}
self.depth += 1;
intravisit::walk_ty(self, ty);
self.depth -= 1;

33
compiler/rustc_hir_analysis/src/lib.rs
View file

@ -102,7 +102,7 @@ use rustc_errors::ErrorGuaranteed;
use rustc_errors::{DiagnosticMessage, SubdiagnosticMessage};
use rustc_hir as hir;
use rustc_hir::Node;
use rustc_infer::infer::{DefineOpaqueTypes, InferOk, TyCtxtInferExt};
use rustc_infer::infer::TyCtxtInferExt;
use rustc_macros::fluent_messages;
use rustc_middle::middle;
use rustc_middle::ty::query::Providers;
@ -113,7 +113,7 @@ use rustc_span::def_id::{DefId, LocalDefId, CRATE_DEF_ID};
use rustc_span::{symbol::sym, Span, DUMMY_SP};
use rustc_target::spec::abi::Abi;
use rustc_trait_selection::traits::error_reporting::TypeErrCtxtExt as _;
use rustc_trait_selection::traits::{self, ObligationCause, ObligationCauseCode};
use rustc_trait_selection::traits::{self, ObligationCause, ObligationCauseCode, ObligationCtxt};
use std::ops::Not;
@ -160,24 +160,21 @@ fn require_c_abi_if_c_variadic(tcx: TyCtxt<'_>, decl: &hir::FnDecl<'_>, abi: Abi
fn require_same_types<'tcx>(
tcx: TyCtxt<'tcx>,
cause: &ObligationCause<'tcx>,
param_env: ty::ParamEnv<'tcx>,
expected: Ty<'tcx>,
actual: Ty<'tcx>,
) -> bool {
) {
let infcx = &tcx.infer_ctxt().build();
let param_env = ty::ParamEnv::empty();
let errors = match infcx.at(cause, param_env).eq(DefineOpaqueTypes::No, expected, actual) {
Ok(InferOk { obligations, .. }) => traits::fully_solve_obligations(infcx, obligations),
let ocx = ObligationCtxt::new(infcx);
match ocx.eq(cause, param_env, expected, actual) {
Ok(()) => {
let errors = ocx.select_all_or_error();
if !errors.is_empty() {
infcx.err_ctxt().report_fulfillment_errors(&errors);
}
}
Err(err) => {
infcx.err_ctxt().report_mismatched_types(cause, expected, actual, err).emit();
return false;
}
};
match &errors[..] {
[] => true,
errors => {
infcx.err_ctxt().report_fulfillment_errors(errors);
false
}
}
}
@ -296,6 +293,8 @@ fn check_main_fn_ty(tcx: TyCtxt<'_>, main_def_id: DefId) {
return;
}
// Main should have no WC, so empty param env is OK here.
let param_env = ty::ParamEnv::empty();
let expected_return_type;
if let Some(term_did) = tcx.lang_items().termination() {
let return_ty = main_fnsig.output();
@ -306,8 +305,6 @@ fn check_main_fn_ty(tcx: TyCtxt<'_>, main_def_id: DefId) {
}
let return_ty = return_ty.skip_binder();
let infcx = tcx.infer_ctxt().build();
// Main should have no WC, so empty param env is OK here.
let param_env = ty::ParamEnv::empty();
let cause = traits::ObligationCause::new(
return_ty_span,
main_diagnostics_def_id,
@ -343,6 +340,7 @@ fn check_main_fn_ty(tcx: TyCtxt<'_>, main_def_id: DefId) {
main_diagnostics_def_id,
ObligationCauseCode::MainFunctionType,
),
param_env,
se_ty,
tcx.mk_fn_ptr(main_fnsig),
);
@ -417,6 +415,7 @@ fn check_start_fn_ty(tcx: TyCtxt<'_>, start_def_id: DefId) {
start_def_id,
ObligationCauseCode::StartFunctionType,
),
ty::ParamEnv::empty(), // start should not have any where bounds.
se_ty,
tcx.mk_fn_ptr(tcx.fn_sig(start_def_id).subst_identity()),
);