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-rw-r--r--compiler/rustc_mir_transform/src/lib.rs217
1 files changed, 102 insertions, 115 deletions
diff --git a/compiler/rustc_mir_transform/src/lib.rs b/compiler/rustc_mir_transform/src/lib.rs
index fc12d423c..65864dc01 100644
--- a/compiler/rustc_mir_transform/src/lib.rs
+++ b/compiler/rustc_mir_transform/src/lib.rs
@@ -1,4 +1,6 @@
#![allow(rustc::potential_query_instability)]
+#![deny(rustc::untranslatable_diagnostic)]
+#![deny(rustc::diagnostic_outside_of_impl)]
#![feature(box_patterns)]
#![feature(drain_filter)]
#![feature(let_chains)]
@@ -23,18 +25,19 @@ use rustc_data_structures::fx::FxIndexSet;
use rustc_data_structures::steal::Steal;
use rustc_hir as hir;
use rustc_hir::def::DefKind;
-use rustc_hir::def_id::{DefId, LocalDefId};
+use rustc_hir::def_id::LocalDefId;
use rustc_hir::intravisit::{self, Visitor};
-use rustc_index::vec::IndexVec;
+use rustc_index::IndexVec;
use rustc_middle::mir::visit::Visitor as _;
use rustc_middle::mir::{
traversal, AnalysisPhase, Body, ClearCrossCrate, ConstQualifs, Constant, LocalDecl, MirPass,
MirPhase, Operand, Place, ProjectionElem, Promoted, RuntimePhase, Rvalue, SourceInfo,
- Statement, StatementKind, TerminatorKind,
+ Statement, StatementKind, TerminatorKind, START_BLOCK,
};
-use rustc_middle::ty::query::Providers;
+use rustc_middle::query::Providers;
use rustc_middle::ty::{self, TyCtxt, TypeVisitableExt};
use rustc_span::sym;
+use rustc_trait_selection::traits;
#[macro_use]
mod pass_manager;
@@ -48,6 +51,7 @@ mod add_retag;
mod check_const_item_mutation;
mod check_packed_ref;
pub mod check_unsafety;
+mod remove_place_mention;
// This pass is public to allow external drivers to perform MIR cleanup
pub mod cleanup_post_borrowck;
mod const_debuginfo;
@@ -67,11 +71,12 @@ pub mod dump_mir;
mod early_otherwise_branch;
mod elaborate_box_derefs;
mod elaborate_drops;
+mod errors;
mod ffi_unwind_calls;
mod function_item_references;
mod generator;
mod inline;
-mod instcombine;
+mod instsimplify;
mod large_enums;
mod lower_intrinsics;
mod lower_slice_len;
@@ -79,6 +84,7 @@ mod match_branches;
mod multiple_return_terminators;
mod normalize_array_len;
mod nrvo;
+mod ref_prop;
mod remove_noop_landing_pads;
mod remove_storage_markers;
mod remove_uninit_drops;
@@ -103,6 +109,11 @@ use rustc_const_eval::transform::promote_consts;
use rustc_const_eval::transform::validate;
use rustc_mir_dataflow::rustc_peek;
+use rustc_errors::{DiagnosticMessage, SubdiagnosticMessage};
+use rustc_fluent_macro::fluent_messages;
+
+fluent_messages! { "../messages.ftl" }
+
pub fn provide(providers: &mut Providers) {
check_unsafety::provide(providers);
coverage::query::provide(providers);
@@ -111,36 +122,17 @@ pub fn provide(providers: &mut Providers) {
*providers = Providers {
mir_keys,
mir_const,
- mir_const_qualif: |tcx, def_id| {
- if let Some(def) = ty::WithOptConstParam::try_lookup(def_id, tcx) {
- tcx.mir_const_qualif_const_arg(def)
- } else {
- mir_const_qualif(tcx, ty::WithOptConstParam::unknown(def_id))
- }
- },
- mir_const_qualif_const_arg: |tcx, (did, param_did)| {
- mir_const_qualif(tcx, ty::WithOptConstParam { did, const_param_did: Some(param_did) })
- },
+ mir_const_qualif,
mir_promoted,
mir_drops_elaborated_and_const_checked,
mir_for_ctfe,
- mir_for_ctfe_of_const_arg,
mir_generator_witnesses: generator::mir_generator_witnesses,
optimized_mir,
is_mir_available,
is_ctfe_mir_available: |tcx, did| is_mir_available(tcx, did),
mir_callgraph_reachable: inline::cycle::mir_callgraph_reachable,
mir_inliner_callees: inline::cycle::mir_inliner_callees,
- promoted_mir: |tcx, def_id| {
- if let Some(def) = ty::WithOptConstParam::try_lookup(def_id, tcx) {
- tcx.promoted_mir_of_const_arg(def)
- } else {
- promoted_mir(tcx, ty::WithOptConstParam::unknown(def_id))
- }
- },
- promoted_mir_of_const_arg: |tcx, (did, param_did)| {
- promoted_mir(tcx, ty::WithOptConstParam { did, const_param_did: Some(param_did) })
- },
+ promoted_mir,
deduced_param_attrs: deduce_param_attrs::deduced_param_attrs,
..*providers
};
@@ -234,8 +226,8 @@ fn mir_keys(tcx: TyCtxt<'_>, (): ()) -> FxIndexSet<LocalDefId> {
set
}
-fn mir_const_qualif(tcx: TyCtxt<'_>, def: ty::WithOptConstParam<LocalDefId>) -> ConstQualifs {
- let const_kind = tcx.hir().body_const_context(def.did);
+fn mir_const_qualif(tcx: TyCtxt<'_>, def: LocalDefId) -> ConstQualifs {
+ let const_kind = tcx.hir().body_const_context(def);
// No need to const-check a non-const `fn`.
if const_kind.is_none() {
@@ -253,7 +245,7 @@ fn mir_const_qualif(tcx: TyCtxt<'_>, def: ty::WithOptConstParam<LocalDefId>) ->
return Default::default();
}
- let ccx = check_consts::ConstCx { body, tcx, const_kind, param_env: tcx.param_env(def.did) };
+ let ccx = check_consts::ConstCx { body, tcx, const_kind, param_env: tcx.param_env(def) };
let mut validator = check_consts::check::Checker::new(&ccx);
validator.check_body();
@@ -266,22 +258,14 @@ fn mir_const_qualif(tcx: TyCtxt<'_>, def: ty::WithOptConstParam<LocalDefId>) ->
/// Make MIR ready for const evaluation. This is run on all MIR, not just on consts!
/// FIXME(oli-obk): it's unclear whether we still need this phase (and its corresponding query).
/// We used to have this for pre-miri MIR based const eval.
-fn mir_const(tcx: TyCtxt<'_>, def: ty::WithOptConstParam<LocalDefId>) -> &Steal<Body<'_>> {
- if let Some(def) = def.try_upgrade(tcx) {
- return tcx.mir_const(def);
- }
-
+fn mir_const(tcx: TyCtxt<'_>, def: LocalDefId) -> &Steal<Body<'_>> {
// Unsafety check uses the raw mir, so make sure it is run.
if !tcx.sess.opts.unstable_opts.thir_unsafeck {
- if let Some(param_did) = def.const_param_did {
- tcx.ensure_with_value().unsafety_check_result_for_const_arg((def.did, param_did));
- } else {
- tcx.ensure_with_value().unsafety_check_result(def.did);
- }
+ tcx.ensure_with_value().unsafety_check_result(def);
}
// has_ffi_unwind_calls query uses the raw mir, so make sure it is run.
- tcx.ensure_with_value().has_ffi_unwind_calls(def.did);
+ tcx.ensure_with_value().has_ffi_unwind_calls(def);
let mut body = tcx.mir_built(def).steal();
@@ -296,7 +280,7 @@ fn mir_const(tcx: TyCtxt<'_>, def: ty::WithOptConstParam<LocalDefId>) -> &Steal<
&Lint(check_const_item_mutation::CheckConstItemMutation),
&Lint(function_item_references::FunctionItemReferences),
// What we need to do constant evaluation.
- &simplify::SimplifyCfg::new("initial"),
+ &simplify::SimplifyCfg::Initial,
&rustc_peek::SanityCheck, // Just a lint
],
None,
@@ -307,16 +291,12 @@ fn mir_const(tcx: TyCtxt<'_>, def: ty::WithOptConstParam<LocalDefId>) -> &Steal<
/// Compute the main MIR body and the list of MIR bodies of the promoteds.
fn mir_promoted(
tcx: TyCtxt<'_>,
- def: ty::WithOptConstParam<LocalDefId>,
+ def: LocalDefId,
) -> (&Steal<Body<'_>>, &Steal<IndexVec<Promoted, Body<'_>>>) {
- if let Some(def) = def.try_upgrade(tcx) {
- return tcx.mir_promoted(def);
- }
-
// Ensure that we compute the `mir_const_qualif` for constants at
// this point, before we steal the mir-const result.
// Also this means promotion can rely on all const checks having been done.
- let const_qualifs = tcx.mir_const_qualif_opt_const_arg(def);
+ let const_qualifs = tcx.mir_const_qualif(def);
let mut body = tcx.mir_const(def).steal();
if let Some(error_reported) = const_qualifs.tainted_by_errors {
body.tainted_by_errors = Some(error_reported);
@@ -334,11 +314,7 @@ fn mir_promoted(
pm::run_passes(
tcx,
&mut body,
- &[
- &promote_pass,
- &simplify::SimplifyCfg::new("promote-consts"),
- &coverage::InstrumentCoverage,
- ],
+ &[&promote_pass, &simplify::SimplifyCfg::PromoteConsts, &coverage::InstrumentCoverage],
Some(MirPhase::Analysis(AnalysisPhase::Initial)),
);
@@ -348,38 +324,22 @@ fn mir_promoted(
/// Compute the MIR that is used during CTFE (and thus has no optimizations run on it)
fn mir_for_ctfe(tcx: TyCtxt<'_>, def_id: LocalDefId) -> &Body<'_> {
- if let Some(def) = ty::WithOptConstParam::try_lookup(def_id, tcx) {
- tcx.mir_for_ctfe_of_const_arg(def)
- } else {
- tcx.arena.alloc(inner_mir_for_ctfe(tcx, ty::WithOptConstParam::unknown(def_id)))
- }
+ tcx.arena.alloc(inner_mir_for_ctfe(tcx, def_id))
}
-/// Same as `mir_for_ctfe`, but used to get the MIR of a const generic parameter.
-/// The docs on `WithOptConstParam` explain this a bit more, but the TLDR is that
-/// we'd get cycle errors with `mir_for_ctfe`, because typeck would need to typeck
-/// the const parameter while type checking the main body, which in turn would try
-/// to type check the main body again.
-fn mir_for_ctfe_of_const_arg(tcx: TyCtxt<'_>, (did, param_did): (LocalDefId, DefId)) -> &Body<'_> {
- tcx.arena.alloc(inner_mir_for_ctfe(
- tcx,
- ty::WithOptConstParam { did, const_param_did: Some(param_did) },
- ))
-}
-
-fn inner_mir_for_ctfe(tcx: TyCtxt<'_>, def: ty::WithOptConstParam<LocalDefId>) -> Body<'_> {
+fn inner_mir_for_ctfe(tcx: TyCtxt<'_>, def: LocalDefId) -> Body<'_> {
// FIXME: don't duplicate this between the optimized_mir/mir_for_ctfe queries
- if tcx.is_constructor(def.did.to_def_id()) {
+ if tcx.is_constructor(def.to_def_id()) {
// There's no reason to run all of the MIR passes on constructors when
// we can just output the MIR we want directly. This also saves const
// qualification and borrow checking the trouble of special casing
// constructors.
- return shim::build_adt_ctor(tcx, def.did.to_def_id());
+ return shim::build_adt_ctor(tcx, def.to_def_id());
}
let context = tcx
.hir()
- .body_const_context(def.did)
+ .body_const_context(def)
.expect("mir_for_ctfe should not be used for runtime functions");
let body = tcx.mir_drops_elaborated_and_const_checked(def).borrow().clone();
@@ -417,29 +377,19 @@ fn inner_mir_for_ctfe(tcx: TyCtxt<'_>, def: ty::WithOptConstParam<LocalDefId>) -
/// Obtain just the main MIR (no promoteds) and run some cleanups on it. This also runs
/// mir borrowck *before* doing so in order to ensure that borrowck can be run and doesn't
/// end up missing the source MIR due to stealing happening.
-fn mir_drops_elaborated_and_const_checked(
- tcx: TyCtxt<'_>,
- def: ty::WithOptConstParam<LocalDefId>,
-) -> &Steal<Body<'_>> {
- if let Some(def) = def.try_upgrade(tcx) {
- return tcx.mir_drops_elaborated_and_const_checked(def);
- }
-
+fn mir_drops_elaborated_and_const_checked(tcx: TyCtxt<'_>, def: LocalDefId) -> &Steal<Body<'_>> {
if tcx.sess.opts.unstable_opts.drop_tracking_mir
- && let DefKind::Generator = tcx.def_kind(def.did)
+ && let DefKind::Generator = tcx.def_kind(def)
{
- tcx.ensure_with_value().mir_generator_witnesses(def.did);
+ tcx.ensure_with_value().mir_generator_witnesses(def);
}
- let mir_borrowck = tcx.mir_borrowck_opt_const_arg(def);
+ let mir_borrowck = tcx.mir_borrowck(def);
- let is_fn_like = tcx.def_kind(def.did).is_fn_like();
+ let is_fn_like = tcx.def_kind(def).is_fn_like();
if is_fn_like {
- let did = def.did.to_def_id();
- let def = ty::WithOptConstParam::unknown(did);
-
// Do not compute the mir call graph without said call graph actually being used.
if inline::Inline.is_enabled(&tcx.sess) {
- tcx.ensure_with_value().mir_inliner_callees(ty::InstanceDef::Item(def));
+ tcx.ensure_with_value().mir_inliner_callees(ty::InstanceDef::Item(def.to_def_id()));
}
}
@@ -449,6 +399,50 @@ fn mir_drops_elaborated_and_const_checked(
body.tainted_by_errors = Some(error_reported);
}
+ // Check if it's even possible to satisfy the 'where' clauses
+ // for this item.
+ //
+ // This branch will never be taken for any normal function.
+ // However, it's possible to `#!feature(trivial_bounds)]` to write
+ // a function with impossible to satisfy clauses, e.g.:
+ // `fn foo() where String: Copy {}`
+ //
+ // We don't usually need to worry about this kind of case,
+ // since we would get a compilation error if the user tried
+ // to call it. However, since we optimize even without any
+ // calls to the function, we need to make sure that it even
+ // makes sense to try to evaluate the body.
+ //
+ // If there are unsatisfiable where clauses, then all bets are
+ // off, and we just give up.
+ //
+ // We manually filter the predicates, skipping anything that's not
+ // "global". We are in a potentially generic context
+ // (e.g. we are evaluating a function without substituting generic
+ // parameters, so this filtering serves two purposes:
+ //
+ // 1. We skip evaluating any predicates that we would
+ // never be able prove are unsatisfiable (e.g. `<T as Foo>`
+ // 2. We avoid trying to normalize predicates involving generic
+ // parameters (e.g. `<T as Foo>::MyItem`). This can confuse
+ // the normalization code (leading to cycle errors), since
+ // it's usually never invoked in this way.
+ let predicates = tcx
+ .predicates_of(body.source.def_id())
+ .predicates
+ .iter()
+ .filter_map(|(p, _)| if p.is_global() { Some(*p) } else { None });
+ if traits::impossible_predicates(tcx, traits::elaborate(tcx, predicates).collect()) {
+ trace!("found unsatisfiable predicates for {:?}", body.source);
+ // Clear the body to only contain a single `unreachable` statement.
+ let bbs = body.basic_blocks.as_mut();
+ bbs.raw.truncate(1);
+ bbs[START_BLOCK].statements.clear();
+ bbs[START_BLOCK].terminator_mut().kind = TerminatorKind::Unreachable;
+ body.var_debug_info.clear();
+ body.local_decls.raw.truncate(body.arg_count + 1);
+ }
+
run_analysis_to_runtime_passes(tcx, &mut body);
tcx.alloc_steal_mir(body)
@@ -467,10 +461,7 @@ fn run_analysis_to_runtime_passes<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>
pm::run_passes(
tcx,
body,
- &[
- &remove_uninit_drops::RemoveUninitDrops,
- &simplify::SimplifyCfg::new("remove-false-edges"),
- ],
+ &[&remove_uninit_drops::RemoveUninitDrops, &simplify::SimplifyCfg::RemoveFalseEdges],
None,
);
check_consts::post_drop_elaboration::check_live_drops(tcx, &body); // FIXME: make this a MIR lint
@@ -492,7 +483,7 @@ fn run_analysis_cleanup_passes<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
let passes: &[&dyn MirPass<'tcx>] = &[
&cleanup_post_borrowck::CleanupPostBorrowck,
&remove_noop_landing_pads::RemoveNoopLandingPads,
- &simplify::SimplifyCfg::new("early-opt"),
+ &simplify::SimplifyCfg::EarlyOpt,
&deref_separator::Derefer,
];
@@ -524,8 +515,11 @@ fn run_runtime_lowering_passes<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
/// Returns the sequence of passes that do the initial cleanup of runtime MIR.
fn run_runtime_cleanup_passes<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
- let passes: &[&dyn MirPass<'tcx>] =
- &[&lower_intrinsics::LowerIntrinsics, &simplify::SimplifyCfg::new("elaborate-drops")];
+ let passes: &[&dyn MirPass<'tcx>] = &[
+ &lower_intrinsics::LowerIntrinsics,
+ &remove_place_mention::RemovePlaceMention,
+ &simplify::SimplifyCfg::ElaborateDrops,
+ ];
pm::run_passes(tcx, body, passes, Some(MirPhase::Runtime(RuntimePhase::PostCleanup)));
@@ -551,7 +545,7 @@ fn run_optimization_passes<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
&lower_slice_len::LowerSliceLenCalls, // has to be done before inlining, otherwise actual call will be almost always inlined. Also simple, so can just do first
&unreachable_prop::UnreachablePropagation,
&uninhabited_enum_branching::UninhabitedEnumBranching,
- &o1(simplify::SimplifyCfg::new("after-uninhabited-enum-branching")),
+ &o1(simplify::SimplifyCfg::AfterUninhabitedEnumBranching),
&inline::Inline,
&remove_storage_markers::RemoveStorageMarkers,
&remove_zsts::RemoveZsts,
@@ -562,25 +556,26 @@ fn run_optimization_passes<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
&match_branches::MatchBranchSimplification,
// inst combine is after MatchBranchSimplification to clean up Ne(_1, false)
&multiple_return_terminators::MultipleReturnTerminators,
- &instcombine::InstCombine,
+ &instsimplify::InstSimplify,
&separate_const_switch::SeparateConstSwitch,
- &simplify::SimplifyLocals::new("before-const-prop"),
+ &simplify::SimplifyLocals::BeforeConstProp,
&copy_prop::CopyProp,
+ &ref_prop::ReferencePropagation,
&const_prop::ConstProp,
&dataflow_const_prop::DataflowConstProp,
//
// Const-prop runs unconditionally, but doesn't mutate the MIR at mir-opt-level=0.
&const_debuginfo::ConstDebugInfo,
- &o1(simplify_branches::SimplifyConstCondition::new("after-const-prop")),
+ &o1(simplify_branches::SimplifyConstCondition::AfterConstProp),
&early_otherwise_branch::EarlyOtherwiseBranch,
&simplify_comparison_integral::SimplifyComparisonIntegral,
&dead_store_elimination::DeadStoreElimination,
&dest_prop::DestinationPropagation,
- &o1(simplify_branches::SimplifyConstCondition::new("final")),
+ &o1(simplify_branches::SimplifyConstCondition::Final),
&o1(remove_noop_landing_pads::RemoveNoopLandingPads),
- &o1(simplify::SimplifyCfg::new("final")),
+ &o1(simplify::SimplifyCfg::Final),
&nrvo::RenameReturnPlace,
- &simplify::SimplifyLocals::new("final"),
+ &simplify::SimplifyLocals::Final,
&multiple_return_terminators::MultipleReturnTerminators,
&deduplicate_blocks::DeduplicateBlocks,
&large_enums::EnumSizeOpt { discrepancy: 128 },
@@ -595,7 +590,6 @@ fn run_optimization_passes<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
/// Optimize the MIR and prepare it for codegen.
fn optimized_mir(tcx: TyCtxt<'_>, did: LocalDefId) -> &Body<'_> {
- assert_eq!(ty::WithOptConstParam::try_lookup(did, tcx), None);
tcx.arena.alloc(inner_optimized_mir(tcx, did))
}
@@ -617,8 +611,7 @@ fn inner_optimized_mir(tcx: TyCtxt<'_>, did: LocalDefId) -> Body<'_> {
Some(other) => panic!("do not use `optimized_mir` for constants: {:?}", other),
}
debug!("about to call mir_drops_elaborated...");
- let body =
- tcx.mir_drops_elaborated_and_const_checked(ty::WithOptConstParam::unknown(did)).steal();
+ let body = tcx.mir_drops_elaborated_and_const_checked(did).steal();
let mut body = remap_mir_for_const_eval_select(tcx, body, hir::Constness::NotConst);
debug!("body: {:#?}", body);
run_optimization_passes(tcx, &mut body);
@@ -628,21 +621,15 @@ fn inner_optimized_mir(tcx: TyCtxt<'_>, did: LocalDefId) -> Body<'_> {
/// Fetch all the promoteds of an item and prepare their MIR bodies to be ready for
/// constant evaluation once all substitutions become known.
-fn promoted_mir(
- tcx: TyCtxt<'_>,
- def: ty::WithOptConstParam<LocalDefId>,
-) -> &IndexVec<Promoted, Body<'_>> {
- if tcx.is_constructor(def.did.to_def_id()) {
+fn promoted_mir(tcx: TyCtxt<'_>, def: LocalDefId) -> &IndexVec<Promoted, Body<'_>> {
+ if tcx.is_constructor(def.to_def_id()) {
return tcx.arena.alloc(IndexVec::new());
}
- let tainted_by_errors = tcx.mir_borrowck_opt_const_arg(def).tainted_by_errors;
+ tcx.ensure_with_value().mir_borrowck(def);
let mut promoted = tcx.mir_promoted(def).1.steal();
for body in &mut promoted {
- if let Some(error_reported) = tainted_by_errors {
- body.tainted_by_errors = Some(error_reported);
- }
run_analysis_to_runtime_passes(tcx, body);
}
generated by cgit v1.2.3 (git 2.39.1) at 2024-07-06 05:10:30 +0000