diff options
Diffstat (limited to 'compiler')
21 files changed, 306 insertions, 503 deletions
diff --git a/compiler/rustc_data_structures/src/graph/iterate/mod.rs b/compiler/rustc_data_structures/src/graph/iterate/mod.rs index bc3d1ce53ba..5f42d46e285 100644 --- a/compiler/rustc_data_structures/src/graph/iterate/mod.rs +++ b/compiler/rustc_data_structures/src/graph/iterate/mod.rs @@ -1,6 +1,7 @@ use super::{DirectedGraph, WithNumNodes, WithStartNode, WithSuccessors}; use rustc_index::bit_set::BitSet; use rustc_index::vec::IndexVec; +use std::ops::ControlFlow; #[cfg(test)] mod tests; @@ -86,10 +87,6 @@ where } } -/// Allows searches to terminate early with a value. -// FIXME (#75744): remove the alias once the generics are in a better order and `C=()`. -pub type ControlFlow<T> = std::ops::ControlFlow<(), T>; - /// The status of a node in the depth-first search. /// /// See the documentation of `TriColorDepthFirstSearch` to see how a node's status is updated diff --git a/compiler/rustc_data_structures/src/profiling.rs b/compiler/rustc_data_structures/src/profiling.rs index 363879cbb1d..0ae3c75fcc2 100644 --- a/compiler/rustc_data_structures/src/profiling.rs +++ b/compiler/rustc_data_structures/src/profiling.rs @@ -111,17 +111,6 @@ cfg_if! { type Profiler = measureme::Profiler<SerializationSink>; -#[derive(Clone, Copy, Debug, PartialEq, Eq, Ord, PartialOrd)] -pub enum ProfileCategory { - Parsing, - Expansion, - TypeChecking, - BorrowChecking, - Codegen, - Linking, - Other, -} - bitflags::bitflags! { struct EventFilter: u32 { const GENERIC_ACTIVITIES = 1 << 0; diff --git a/compiler/rustc_hir/src/lang_items.rs b/compiler/rustc_hir/src/lang_items.rs index 5e4c03bec83..3e4eb9eafd7 100644 --- a/compiler/rustc_hir/src/lang_items.rs +++ b/compiler/rustc_hir/src/lang_items.rs @@ -263,6 +263,7 @@ language_item_table! { // is required to define it somewhere. Additionally, there are restrictions on crates that use // a weak lang item, but do not have it defined. Panic, sym::panic, panic_fn, Target::Fn; + PanicStr, sym::panic_str, panic_str, Target::Fn; PanicBoundsCheck, sym::panic_bounds_check, panic_bounds_check_fn, Target::Fn; PanicInfo, sym::panic_info, panic_info, Target::Struct; PanicLocation, sym::panic_location, panic_location, Target::Struct; diff --git a/compiler/rustc_macros/src/query.rs b/compiler/rustc_macros/src/query.rs index e7c054653ac..fd859196369 100644 --- a/compiler/rustc_macros/src/query.rs +++ b/compiler/rustc_macros/src/query.rs @@ -190,7 +190,11 @@ impl<T: Parse> Parse for List<T> { } /// A named group containing queries. +/// +/// For now, the name is not used any more, but the capability remains interesting for future +/// developments of the query system. struct Group { + #[allow(unused)] name: Ident, queries: List<Query>, } @@ -417,12 +421,9 @@ pub fn rustc_queries(input: TokenStream) -> TokenStream { let mut query_stream = quote! {}; let mut query_description_stream = quote! {}; let mut dep_node_def_stream = quote! {}; - let mut dep_node_force_stream = quote! {}; - let mut try_load_from_on_disk_cache_stream = quote! {}; let mut cached_queries = quote! {}; for group in groups.0 { - let mut group_stream = quote! {}; for mut query in group.queries.0 { let modifiers = process_modifiers(&mut query); let name = &query.name; @@ -437,22 +438,6 @@ pub fn rustc_queries(input: TokenStream) -> TokenStream { cached_queries.extend(quote! { #name, }); - - try_load_from_on_disk_cache_stream.extend(quote! { - ::rustc_middle::dep_graph::DepKind::#name => { - if <#arg as DepNodeParams<TyCtxt<'_>>>::can_reconstruct_query_key() { - debug_assert!($tcx.dep_graph - .node_color($dep_node) - .map(|c| c.is_green()) - .unwrap_or(false)); - - let key = <#arg as DepNodeParams<TyCtxt<'_>>>::recover($tcx, $dep_node).unwrap(); - if queries::#name::cache_on_disk($tcx, &key, None) { - let _ = $tcx.#name(key); - } - } - } - }); } let mut attributes = Vec::new(); @@ -485,9 +470,9 @@ pub fn rustc_queries(input: TokenStream) -> TokenStream { let attribute_stream = quote! {#(#attributes),*}; let doc_comments = query.doc_comments.iter(); // Add the query to the group - group_stream.extend(quote! { + query_stream.extend(quote! { #(#doc_comments)* - [#attribute_stream] fn #name: #name(#arg) #result, + [#attribute_stream] fn #name(#arg) #result, }); // Create a dep node for the query @@ -495,37 +480,10 @@ pub fn rustc_queries(input: TokenStream) -> TokenStream { [#attribute_stream] #name(#arg), }); - // Add a match arm to force the query given the dep node - dep_node_force_stream.extend(quote! { - ::rustc_middle::dep_graph::DepKind::#name => { - if <#arg as DepNodeParams<TyCtxt<'_>>>::can_reconstruct_query_key() { - if let Some(key) = <#arg as DepNodeParams<TyCtxt<'_>>>::recover($tcx, $dep_node) { - force_query::<crate::ty::query::queries::#name<'_>, _>( - $tcx, - key, - DUMMY_SP, - *$dep_node - ); - return true; - } - } - } - }); - add_query_description_impl(&query, modifiers, &mut query_description_stream); } - let name = &group.name; - query_stream.extend(quote! { - #name { #group_stream }, - }); } - dep_node_force_stream.extend(quote! { - ::rustc_middle::dep_graph::DepKind::Null => { - bug!("Cannot force dep node: {:?}", $dep_node) - } - }); - TokenStream::from(quote! { macro_rules! rustc_query_append { ([$($macro:tt)*][$($other:tt)*]) => { @@ -546,15 +504,6 @@ pub fn rustc_queries(input: TokenStream) -> TokenStream { ); } } - macro_rules! rustc_dep_node_force { - ([$dep_node:expr, $tcx:expr] $($other:tt)*) => { - match $dep_node.kind { - $($other)* - - #dep_node_force_stream - } - } - } macro_rules! rustc_cached_queries { ($($macro:tt)*) => { $($macro)*(#cached_queries); @@ -562,14 +511,5 @@ pub fn rustc_queries(input: TokenStream) -> TokenStream { } #query_description_stream - - macro_rules! rustc_dep_node_try_load_from_on_disk_cache { - ($dep_node:expr, $tcx:expr) => { - match $dep_node.kind { - #try_load_from_on_disk_cache_stream - _ => (), - } - } - } }) } diff --git a/compiler/rustc_middle/src/ty/context.rs b/compiler/rustc_middle/src/ty/context.rs index ab92e5b745b..f6ea6743a0e 100644 --- a/compiler/rustc_middle/src/ty/context.rs +++ b/compiler/rustc_middle/src/ty/context.rs @@ -2036,13 +2036,13 @@ direct_interners! { macro_rules! slice_interners { ($($field:ident: $method:ident($ty:ty)),+ $(,)?) => ( - $(impl<'tcx> TyCtxt<'tcx> { - pub fn $method(self, v: &[$ty]) -> &'tcx List<$ty> { + impl<'tcx> TyCtxt<'tcx> { + $(pub fn $method(self, v: &[$ty]) -> &'tcx List<$ty> { self.interners.$field.intern_ref(v, || { Interned(List::from_arena(&*self.arena, v)) }).0 - } - })+ + })+ + } ); } diff --git a/compiler/rustc_middle/src/ty/query/mod.rs b/compiler/rustc_middle/src/ty/query/mod.rs index d3a7412ef14..7ba4d5a14df 100644 --- a/compiler/rustc_middle/src/ty/query/mod.rs +++ b/compiler/rustc_middle/src/ty/query/mod.rs @@ -34,7 +34,6 @@ use crate::ty::util::AlwaysRequiresDrop; use crate::ty::{self, AdtSizedConstraint, CrateInherentImpls, ParamEnvAnd, Ty, TyCtxt}; use rustc_data_structures::fingerprint::Fingerprint; use rustc_data_structures::fx::{FxHashMap, FxHashSet, FxIndexMap}; -use rustc_data_structures::profiling::ProfileCategory::*; use rustc_data_structures::stable_hasher::StableVec; use rustc_data_structures::svh::Svh; use rustc_data_structures::sync::Lrc; @@ -169,26 +168,71 @@ pub fn force_from_dep_node<'tcx>(tcx: TyCtxt<'tcx>, dep_node: &DepNode) -> bool return false; } - rustc_dep_node_force!([dep_node, tcx] - // These are inputs that are expected to be pre-allocated and that - // should therefore always be red or green already. - DepKind::CrateMetadata | + macro_rules! force_from_dep_node { + ($($(#[$attr:meta])* [$($modifiers:tt)*] $name:ident($K:ty),)*) => { + match dep_node.kind { + // These are inputs that are expected to be pre-allocated and that + // should therefore always be red or green already. + DepKind::CrateMetadata | - // These are anonymous nodes. - DepKind::TraitSelect | + // These are anonymous nodes. + DepKind::TraitSelect | - // We don't have enough information to reconstruct the query key of - // these. - DepKind::CompileCodegenUnit => { - bug!("force_from_dep_node: encountered {:?}", dep_node) + // We don't have enough information to reconstruct the query key of + // these. + DepKind::CompileCodegenUnit | + + // Forcing this makes no sense. + DepKind::Null => { + bug!("force_from_dep_node: encountered {:?}", dep_node) + } + + $(DepKind::$name => { + debug_assert!(<$K as DepNodeParams<TyCtxt<'_>>>::can_reconstruct_query_key()); + + if let Some(key) = <$K as DepNodeParams<TyCtxt<'_>>>::recover(tcx, dep_node) { + force_query::<queries::$name<'_>, _>( + tcx, + key, + DUMMY_SP, + *dep_node + ); + return true; + } + })* + } } - ); + } + + rustc_dep_node_append! { [force_from_dep_node!][] } false } pub(crate) fn try_load_from_on_disk_cache<'tcx>(tcx: TyCtxt<'tcx>, dep_node: &DepNode) { - rustc_dep_node_try_load_from_on_disk_cache!(dep_node, tcx) + macro_rules! try_load_from_on_disk_cache { + ($($name:ident,)*) => { + match dep_node.kind { + $(DepKind::$name => { + if <query_keys::$name<'tcx> as DepNodeParams<TyCtxt<'_>>>::can_reconstruct_query_key() { + debug_assert!(tcx.dep_graph + .node_color(dep_node) + .map(|c| c.is_green()) + .unwrap_or(false)); + + let key = <query_keys::$name<'tcx> as DepNodeParams<TyCtxt<'_>>>::recover(tcx, dep_node).unwrap(); + if queries::$name::cache_on_disk(tcx, &key, None) { + let _ = tcx.$name(key); + } + } + })* + + _ => (), + } + } + } + + rustc_cached_queries!(try_load_from_on_disk_cache!); } mod sealed { diff --git a/compiler/rustc_middle/src/ty/query/plumbing.rs b/compiler/rustc_middle/src/ty/query/plumbing.rs index 1a8aacc4869..d038695283c 100644 --- a/compiler/rustc_middle/src/ty/query/plumbing.rs +++ b/compiler/rustc_middle/src/ty/query/plumbing.rs @@ -242,25 +242,15 @@ macro_rules! hash_result { }; } -macro_rules! define_queries { - (<$tcx:tt> $($category:tt { - $($(#[$attr:meta])* [$($modifiers:tt)*] fn $name:ident: $node:ident($($K:tt)*) -> $V:ty,)* - },)*) => { - define_queries_inner! { <$tcx> - $($( $(#[$attr])* category<$category> [$($modifiers)*] fn $name: $node($($K)*) -> $V,)*)* - } - } -} - macro_rules! query_helper_param_ty { (DefId) => { impl IntoQueryParam<DefId> }; ($K:ty) => { $K }; } -macro_rules! define_queries_inner { +macro_rules! define_queries { (<$tcx:tt> - $($(#[$attr:meta])* category<$category:tt> - [$($modifiers:tt)*] fn $name:ident: $node:ident($($K:tt)*) -> $V:ty,)*) => { + $($(#[$attr:meta])* + [$($modifiers:tt)*] fn $name:ident($($K:tt)*) -> $V:ty,)*) => { use std::mem; use crate::{ @@ -268,7 +258,6 @@ macro_rules! define_queries_inner { rustc_data_structures::stable_hasher::StableHasher, ich::StableHashingContext }; - use rustc_data_structures::profiling::ProfileCategory; define_queries_struct! { tcx: $tcx, @@ -362,13 +351,12 @@ macro_rules! define_queries_inner { as QueryStorage >::Stored; const NAME: &'static str = stringify!($name); - const CATEGORY: ProfileCategory = $category; } impl<$tcx> QueryAccessors<TyCtxt<$tcx>> for queries::$name<$tcx> { const ANON: bool = is_anon!([$($modifiers)*]); const EVAL_ALWAYS: bool = is_eval_always!([$($modifiers)*]); - const DEP_KIND: dep_graph::DepKind = dep_graph::DepKind::$node; + const DEP_KIND: dep_graph::DepKind = dep_graph::DepKind::$name; type Cache = query_storage!([$($modifiers)*][$($K)*, $V]); diff --git a/compiler/rustc_middle/src/ty/query/stats.rs b/compiler/rustc_middle/src/ty/query/stats.rs index 877f88d380a..e0b44ce23c9 100644 --- a/compiler/rustc_middle/src/ty/query/stats.rs +++ b/compiler/rustc_middle/src/ty/query/stats.rs @@ -120,13 +120,13 @@ pub fn print_stats(tcx: TyCtxt<'_>) { } macro_rules! print_stats { - (<$tcx:tt> $($category:tt { - $($(#[$attr:meta])* [$($modifiers:tt)*] fn $name:ident: $node:ident($K:ty) -> $V:ty,)* - },)*) => { + (<$tcx:tt> + $($(#[$attr:meta])* [$($modifiers:tt)*] fn $name:ident($K:ty) -> $V:ty,)* + ) => { fn query_stats(tcx: TyCtxt<'_>) -> Vec<QueryStats> { let mut queries = Vec::new(); - $($( + $( queries.push(stats::< crate::dep_graph::DepKind, <TyCtxt<'_> as QueryContext>::Query, @@ -135,7 +135,7 @@ macro_rules! print_stats { stringify!($name), &tcx.queries.$name, )); - )*)* + )* queries } diff --git a/compiler/rustc_mir/src/const_eval/machine.rs b/compiler/rustc_mir/src/const_eval/machine.rs index 73ca7e0d471..7e2cae09481 100644 --- a/compiler/rustc_mir/src/const_eval/machine.rs +++ b/compiler/rustc_mir/src/const_eval/machine.rs @@ -70,9 +70,10 @@ impl<'mir, 'tcx> InterpCx<'mir, 'tcx, CompileTimeInterpreter<'mir, 'tcx>> { ) -> InterpResult<'tcx> { let def_id = instance.def_id(); if Some(def_id) == self.tcx.lang_items().panic_fn() + || Some(def_id) == self.tcx.lang_items().panic_str() || Some(def_id) == self.tcx.lang_items().begin_panic_fn() { - // &'static str + // &str assert!(args.len() == 1); let msg_place = self.deref_operand(args[0])?; diff --git a/compiler/rustc_mir/src/transform/check_consts/mod.rs b/compiler/rustc_mir/src/transform/check_consts/mod.rs index 33815ceba62..b93d63b4fdd 100644 --- a/compiler/rustc_mir/src/transform/check_consts/mod.rs +++ b/compiler/rustc_mir/src/transform/check_consts/mod.rs @@ -74,7 +74,9 @@ impl ConstCx<'mir, 'tcx> { /// Returns `true` if this `DefId` points to one of the official `panic` lang items. pub fn is_lang_panic_fn(tcx: TyCtxt<'tcx>, def_id: DefId) -> bool { - Some(def_id) == tcx.lang_items().panic_fn() || Some(def_id) == tcx.lang_items().begin_panic_fn() + Some(def_id) == tcx.lang_items().panic_fn() + || Some(def_id) == tcx.lang_items().panic_str() + || Some(def_id) == tcx.lang_items().begin_panic_fn() } pub fn allow_internal_unstable(tcx: TyCtxt<'tcx>, def_id: DefId, feature_gate: Symbol) -> bool { diff --git a/compiler/rustc_mir/src/transform/match_branches.rs b/compiler/rustc_mir/src/transform/match_branches.rs index 0f9b2ff5ab8..06690dcbf6e 100644 --- a/compiler/rustc_mir/src/transform/match_branches.rs +++ b/compiler/rustc_mir/src/transform/match_branches.rs @@ -38,19 +38,16 @@ pub struct MatchBranchSimplification; impl<'tcx> MirPass<'tcx> for MatchBranchSimplification { fn run_pass(&self, tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) { - // FIXME: This optimization can result in unsoundness, because it introduces - // additional uses of a place holding the discriminant value without ensuring that - // it is valid to do so. - if !tcx.sess.opts.debugging_opts.unsound_mir_opts { + if tcx.sess.opts.debugging_opts.mir_opt_level <= 1 { return; } let param_env = tcx.param_env(body.source.def_id()); - let bbs = body.basic_blocks_mut(); + let (bbs, local_decls) = body.basic_blocks_and_local_decls_mut(); 'outer: for bb_idx in bbs.indices() { let (discr, val, switch_ty, first, second) = match bbs[bb_idx].terminator().kind { TerminatorKind::SwitchInt { - discr: Operand::Copy(ref place) | Operand::Move(ref place), + discr: ref discr @ (Operand::Copy(_) | Operand::Move(_)), switch_ty, ref targets, .. @@ -59,7 +56,7 @@ impl<'tcx> MirPass<'tcx> for MatchBranchSimplification { if target == targets.otherwise() { continue; } - (place, value, switch_ty, target, targets.otherwise()) + (discr, value, switch_ty, target, targets.otherwise()) } // Only optimize switch int statements _ => continue, @@ -99,6 +96,10 @@ impl<'tcx> MirPass<'tcx> for MatchBranchSimplification { // Take ownership of items now that we know we can optimize. let discr = discr.clone(); + // Introduce a temporary for the discriminant value. + let source_info = bbs[bb_idx].terminator().source_info; + let discr_local = local_decls.push(LocalDecl::new(switch_ty, source_info.span)); + // We already checked that first and second are different blocks, // and bb_idx has a different terminator from both of them. let (from, first, second) = bbs.pick3_mut(bb_idx, first, second); @@ -127,7 +128,11 @@ impl<'tcx> MirPass<'tcx> for MatchBranchSimplification { rustc_span::DUMMY_SP, ); let op = if f_b { BinOp::Eq } else { BinOp::Ne }; - let rhs = Rvalue::BinaryOp(op, Operand::Copy(discr.clone()), const_cmp); + let rhs = Rvalue::BinaryOp( + op, + Operand::Copy(Place::from(discr_local)), + const_cmp, + ); Statement { source_info: f.source_info, kind: StatementKind::Assign(box (*lhs, rhs)), @@ -138,7 +143,16 @@ impl<'tcx> MirPass<'tcx> for MatchBranchSimplification { _ => unreachable!(), } }); + + from.statements + .push(Statement { source_info, kind: StatementKind::StorageLive(discr_local) }); + from.statements.push(Statement { + source_info, + kind: StatementKind::Assign(box (Place::from(discr_local), Rvalue::Use(discr))), + }); from.statements.extend(new_stmts); + from.statements + .push(Statement { source_info, kind: StatementKind::StorageDead(discr_local) }); from.terminator_mut().kind = first.terminator().kind.clone(); } } diff --git a/compiler/rustc_mir_build/src/lints.rs b/compiler/rustc_mir_build/src/lints.rs index a9620b83124..576b537c017 100644 --- a/compiler/rustc_mir_build/src/lints.rs +++ b/compiler/rustc_mir_build/src/lints.rs @@ -1,5 +1,5 @@ use rustc_data_structures::graph::iterate::{ - ControlFlow, NodeStatus, TriColorDepthFirstSearch, TriColorVisitor, + NodeStatus, TriColorDepthFirstSearch, TriColorVisitor, }; use rustc_hir::intravisit::FnKind; use rustc_middle::hir::map::blocks::FnLikeNode; @@ -8,6 +8,7 @@ use rustc_middle::ty::subst::{GenericArg, InternalSubsts}; use rustc_middle::ty::{self, AssocItem, AssocItemContainer, Instance, TyCtxt}; use rustc_session::lint::builtin::UNCONDITIONAL_RECURSION; use rustc_span::Span; +use std::ops::ControlFlow; crate fn check<'tcx>(tcx: TyCtxt<'tcx>, body: &Body<'tcx>) { let def_id = body.source.def_id().expect_local(); diff --git a/compiler/rustc_mir_build/src/thir/pattern/_match.rs b/compiler/rustc_mir_build/src/thir/pattern/_match.rs index 7216d1305fd..0449e149831 100644 --- a/compiler/rustc_mir_build/src/thir/pattern/_match.rs +++ b/compiler/rustc_mir_build/src/thir/pattern/_match.rs @@ -302,10 +302,9 @@ use super::{FieldPat, Pat, PatKind, PatRange}; use rustc_arena::TypedArena; use rustc_attr::{SignedInt, UnsignedInt}; -use rustc_errors::ErrorReported; use rustc_hir::def_id::DefId; use rustc_hir::{HirId, RangeEnd}; -use rustc_middle::mir::interpret::{truncate, AllocId, ConstValue, Pointer, Scalar}; +use rustc_middle::mir::interpret::{truncate, ConstValue}; use rustc_middle::mir::Field; use rustc_middle::ty::layout::IntegerExt; use rustc_middle::ty::{self, Const, Ty, TyCtxt}; @@ -314,108 +313,21 @@ use rustc_span::{Span, DUMMY_SP}; use rustc_target::abi::{Integer, Size, VariantIdx}; use smallvec::{smallvec, SmallVec}; -use std::borrow::Cow; use std::cmp::{self, max, min, Ordering}; -use std::convert::TryInto; use std::fmt; use std::iter::{FromIterator, IntoIterator}; use std::ops::RangeInclusive; -crate fn expand_pattern<'a, 'tcx>(cx: &MatchCheckCtxt<'a, 'tcx>, pat: Pat<'tcx>) -> Pat<'tcx> { - LiteralExpander { tcx: cx.tcx, param_env: cx.param_env }.fold_pattern(&pat) +crate fn expand_pattern<'tcx>(pat: Pat<'tcx>) -> Pat<'tcx> { + LiteralExpander.fold_pattern(&pat) } -struct LiteralExpander<'tcx> { - tcx: TyCtxt<'tcx>, - param_env: ty::ParamEnv<'tcx>, -} +struct LiteralExpander; -impl<'tcx> LiteralExpander<'tcx> { - /// Derefs `val` and potentially unsizes the value if `crty` is an array and `rty` a slice. - /// - /// `crty` and `rty` can differ because you can use array constants in the presence of slice - /// patterns. So the pattern may end up being a slice, but the constant is an array. We convert - /// the array to a slice in that case. - fn fold_const_value_deref( - &mut self, - val: ConstValue<'tcx>, - // the pattern's pointee type - rty: Ty<'tcx>, - // the constant's pointee type - crty: Ty<'tcx>, - ) -> ConstValue<'tcx> { - debug!("fold_const_value_deref {:?} {:?} {:?}", val, rty, crty); - match (val, &crty.kind(), &rty.kind()) { - // the easy case, deref a reference - (ConstValue::Scalar(p), x, y) if x == y => { - match p { - Scalar::Ptr(p) => { - let alloc = self.tcx.global_alloc(p.alloc_id).unwrap_memory(); - ConstValue::ByRef { alloc, offset: p.offset } - } - Scalar::Raw { .. } => { - let layout = self.tcx.layout_of(self.param_env.and(rty)).unwrap(); - if layout.is_zst() { - // Deref of a reference to a ZST is a nop. - ConstValue::Scalar(Scalar::zst()) - } else { - // FIXME(oli-obk): this is reachable for `const FOO: &&&u32 = &&&42;` - bug!("cannot deref {:#?}, {} -> {}", val, crty, rty); - } - } - } - } - // unsize array to slice if pattern is array but match value or other patterns are slice - (ConstValue::Scalar(Scalar::Ptr(p)), ty::Array(t, n), ty::Slice(u)) => { - assert_eq!(t, u); - ConstValue::Slice { - data: self.tcx.global_alloc(p.alloc_id).unwrap_memory(), - start: p.offset.bytes().try_into().unwrap(), - end: n.eval_usize(self.tcx, ty::ParamEnv::empty()).try_into().unwrap(), - } - } - // fat pointers stay the same - (ConstValue::Slice { .. }, _, _) - | (_, ty::Slice(_), ty::Slice(_)) - | (_, ty::Str, ty::Str) => val, - // FIXME(oli-obk): this is reachable for `const FOO: &&&u32 = &&&42;` being used - _ => bug!("cannot deref {:#?}, {} -> {}", val, crty, rty), - } - } -} - -impl<'tcx> PatternFolder<'tcx> for LiteralExpander<'tcx> { +impl<'tcx> PatternFolder<'tcx> for LiteralExpander { fn fold_pattern(&mut self, pat: &Pat<'tcx>) -> Pat<'tcx> { debug!("fold_pattern {:?} {:?} {:?}", pat, pat.ty.kind(), pat.kind); match (pat.ty.kind(), &*pat.kind) { - (&ty::Ref(_, rty, _), &PatKind::Constant { value: Const { val, ty: const_ty } }) - if const_ty.is_ref() => - { - let crty = - if let ty::Ref(_, crty, _) = const_ty.kind() { crty } else { unreachable!() }; - if let ty::ConstKind::Value(val) = val { - Pat { - ty: pat.ty, - span: pat.span, - kind: box PatKind::Deref { - subpattern: Pat { - ty: rty, - span: pat.span, - kind: box PatKind::Constant { - value: Const::from_value( - self.tcx, - self.fold_const_value_deref(*val, rty, crty), - rty, - ), - }, - }, - }, - } - } else { - bug!("cannot deref {:#?}, {} -> {}", val, crty, rty) - } - } - (_, &PatKind::Binding { subpattern: Some(ref s), .. }) => s.fold_with(self), (_, &PatKind::AscribeUserType { subpattern: ref s, .. }) => s.fold_with(self), _ => pat.super_fold_with(self), @@ -500,9 +412,15 @@ impl<'p, 'tcx> PatStack<'p, 'tcx> { cx: &mut MatchCheckCtxt<'p, 'tcx>, constructor: &Constructor<'tcx>, ctor_wild_subpatterns: &Fields<'p, 'tcx>, + is_my_head_ctor: bool, ) -> Option<PatStack<'p, 'tcx>> { - let new_fields = - specialize_one_pattern(cx, self.head(), constructor, ctor_wild_subpatterns)?; + let new_fields = specialize_one_pattern( + cx, + self.head(), + constructor, + ctor_wild_subpatterns, + is_my_head_ctor, + )?; Some(new_fields.push_on_patstack(&self.0[1..])) } } @@ -680,6 +598,7 @@ impl<'p, 'tcx> Matrix<'p, 'tcx> { cx, constructor, ctor_wild_subpatterns, + false, ) }) .collect() @@ -705,7 +624,9 @@ impl<'p, 'tcx> Matrix<'p, 'tcx> { SpecializationCache::Incompatible => self .patterns .iter() - .filter_map(|r| r.specialize_constructor(cx, constructor, ctor_wild_subpatterns)) + .filter_map(|r| { + r.specialize_constructor(cx, constructor, ctor_wild_subpatterns, false) + }) .collect(), } } @@ -725,6 +646,7 @@ impl<'p, 'tcx> Matrix<'p, 'tcx> { /// +++++++++++++++++++++++++++++ /// + _ + [_, _, tail @ ..] + /// +++++++++++++++++++++++++++++ +/// ``` impl<'p, 'tcx> fmt::Debug for Matrix<'p, 'tcx> { fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { write!(f, "\n")?; @@ -926,42 +848,30 @@ enum Constructor<'tcx> { Single, /// Enum variants. Variant(DefId), - /// Literal values. - ConstantValue(&'tcx ty::Const<'tcx>), /// Ranges of integer literal values (`2`, `2..=5` or `2..5`). IntRange(IntRange<'tcx>), /// Ranges of floating-point literal values (`2.0..=5.2`). FloatRange(&'tcx ty::Const<'tcx>, &'tcx ty::Const<'tcx>, RangeEnd), + /// String literals. Strings are not quite the same as `&[u8]` so we treat them separately. + Str(&'tcx ty::Const<'tcx>), /// Array and slice patterns. Slice(Slice), + /// Constants that must not be matched structurally. They are treated as black + /// boxes for the purposes of exhaustiveness: we must not inspect them, and they + /// don't count towards making a match exhaustive. + Opaque, /// Fake extra constructor for enums that aren't allowed to be matched exhaustively. NonExhaustive, } impl<'tcx> Constructor<'tcx> { - fn is_slice(&self) -> bool { - match self { - Slice(_) => true, - _ => false, - } - } - - fn variant_index_for_adt<'a>( - &self, - cx: &MatchCheckCtxt<'a, 'tcx>, - adt: &'tcx ty::AdtDef, - ) -> VariantIdx { + fn variant_index_for_adt(&self, adt: &'tcx ty::AdtDef) -> VariantIdx { match *self { Variant(id) => adt.variant_index_with_id(id), Single => { assert!(!adt.is_enum()); VariantIdx::new(0) } - ConstantValue(c) => cx - .tcx - .destructure_const(cx.param_env.and(c)) - .variant - .expect("destructed const of adt without variant id"), _ => bug!("bad constructor {:?} for adt {:?}", self, adt), } } @@ -975,7 +885,7 @@ impl<'tcx> Constructor<'tcx> { match self { // Those constructors can only match themselves. - Single | Variant(_) | ConstantValue(..) | FloatRange(..) => { + Single | Variant(_) | Str(..) | FloatRange(..) => { if other_ctors.iter().any(|c| c == self) { vec![] } else { vec![self.clone()] } } &Slice(slice) => { @@ -983,8 +893,6 @@ impl<'tcx> Constructor<'tcx> { .iter() .filter_map(|c: &Constructor<'_>| match c { Slice(slice) => Some(*slice), - // FIXME(oli-obk): implement `deref` for `ConstValue` - ConstantValue(..) => None, _ => bug!("bad slice pattern constructor {:?}", c), }) .map(Slice::value_kind); @@ -1048,6 +956,7 @@ impl<'tcx> Constructor<'tcx> { } // This constructor is never covered by anything else NonExhaustive => vec![NonExhaustive], + Opaque => bug!("unexpected opaque ctor {:?} found in all_ctors", self), } } @@ -1087,7 +996,7 @@ impl<'tcx> Constructor<'tcx> { PatKind::Variant { adt_def: adt, substs, - variant_index: self.variant_index_for_adt(cx, adt), + variant_index: self.variant_index_for_adt(adt), subpatterns, } } else { @@ -1126,10 +1035,11 @@ impl<'tcx> Constructor<'tcx> { PatKind::Slice { prefix, slice: Some(wild), suffix } } }, - &ConstantValue(value) => PatKind::Constant { value }, + &Str(value) => PatKind::Constant { value }, &FloatRange(lo, hi, end) => PatKind::Range(PatRange { lo, hi, end }), IntRange(range) => return range.to_pat(cx.tcx), NonExhaustive => PatKind::Wild, + Opaque => bug!("we should not try to apply an opaque constructor {:?}", self), }; Pat { ty, span: DUMMY_SP, kind: Box::new(pat) } @@ -1204,12 +1114,6 @@ impl<'p, 'tcx> Fields<'p, 'tcx> { Fields::Slice(std::slice::from_ref(pat)) } - /// Construct a new `Fields` from the given patterns. You must be sure those patterns can't - /// contain fields that need to be filtered out. When in doubt, prefer `replace_fields`. - fn from_slice_unfiltered(pats: &'p [Pat<'tcx>]) -> Self { - Fields::Slice(pats) - } - /// Convenience; internal use. fn wildcards_from_tys( cx: &MatchCheckCtxt<'p, 'tcx>, @@ -1239,7 +1143,7 @@ impl<'p, 'tcx> Fields<'p, 'tcx> { // Use T as the sub pattern type of Box<T>. Fields::from_single_pattern(wildcard_from_ty(substs.type_at(0))) } else { - let variant = &adt.variants[constructor.variant_index_for_adt(cx, adt)]; + let variant = &adt.variants[constructor.variant_index_for_adt(adt)]; // Whether we must not match the fields of this variant exhaustively. let is_non_exhaustive = variant.is_field_list_non_exhaustive() && !adt.did.is_local(); @@ -1287,7 +1191,7 @@ impl<'p, 'tcx> Fields<'p, 'tcx> { } _ => bug!("bad slice pattern {:?} {:?}", constructor, ty), }, - ConstantValue(..) | FloatRange(..) | IntRange(..) | NonExhaustive => Fields::empty(), + Str(..) | FloatRange(..) | IntRange(..) | NonExhaustive | Opaque => Fields::empty(), }; debug!("Fields::wildcards({:?}, {:?}) = {:#?}", constructor, ty, ret); ret @@ -1600,9 +1504,7 @@ fn all_constructors<'a, 'tcx>( ) }; match *pcx.ty.kind() { - ty::Bool => { - [true, false].iter().map(|&b| ConstantValue(ty::Const::from_bool(cx.tcx, b))).collect() - } + ty::Bool => vec![make_range(0, 1)], ty::Array(ref sub_ty, len) if len.try_eval_usize(cx.tcx, cx.param_env).is_some() => { let len = len.eval_usize(cx.tcx, cx.param_env); if len != 0 && cx.is_uninhabited(sub_ty) { @@ -1717,7 +1619,7 @@ impl<'tcx> IntRange<'tcx> { #[inline] fn is_integral(ty: Ty<'_>) -> bool { match ty.kind() { - ty::Char | ty::Int(_) | ty::Uint(_) => true, + ty::Char | ty::Int(_) | ty::Uint(_) | ty::Bool => true, _ => false, } } @@ -1739,6 +1641,7 @@ impl<'tcx> IntRange<'tcx> { #[inline] fn integral_size_and_signed_bias(tcx: TyCtxt<'tcx>, ty: Ty<'_>) -> Option<(Size, u128)> { match *ty.kind() { + ty::Bool => Some((Size::from_bytes(1), 0)), ty::Char => Some((Size::from_bytes(4), 0)), ty::Int(ity) => { let size = Integer::from_attr(&tcx, SignedInt(ity)).size(); @@ -2230,7 +2133,7 @@ fn is_useful_specialized<'p, 'tcx>( // We cache the result of `Fields::wildcards` because it is used a lot. let ctor_wild_subpatterns = Fields::wildcards(cx, &ctor, ty); let matrix = matrix.specialize_constructor(cx, &ctor, &ctor_wild_subpatterns); - v.specialize_constructor(cx, &ctor, &ctor_wild_subpatterns) + v.specialize_constructor(cx, &ctor, &ctor_wild_subpatterns, true) .map(|v| is_useful(cx, &matrix, &v, witness_preference, hir_id, is_under_guard, false)) .map(|u| u.apply_constructor(cx, &ctor, ty, &ctor_wild_subpatterns)) .unwrap_or(NotUseful) @@ -2255,18 +2158,13 @@ fn pat_constructor<'tcx>( if let Some(int_range) = IntRange::from_const(tcx, param_env, value, pat.span) { Some(IntRange(int_range)) } else { - match (value.val, &value.ty.kind()) { - (_, ty::Array(_, n)) => { - let len = n.eval_usize(tcx, param_env); - Some(Slice(Slice { array_len: Some(len), kind: FixedLen(len) })) - } - (ty::ConstKind::Value(ConstValue::Slice { start, end, .. }), ty::Slice(_)) => { - let len = (end - start) as u64; - Some(Slice(Slice { array_len: None, kind: FixedLen(len) })) - } - // FIXME(oli-obk): implement `deref` for `ConstValue` - // (ty::ConstKind::Value(ConstValue::ByRef { .. }), ty::Slice(_)) => { ... } - _ => Some(ConstantValue(value)), + match value.ty.kind() { + ty::Float(_) => Some(FloatRange(value, value, RangeEnd::Included)), + ty::Ref(_, t, _) if t.is_str() => Some(Str(value)), + // All constants that can be structurally matched have already been expanded + // into the corresponding `Pat`s by `const_to_pat`. Constants that remain are + // opaque. + _ => Some(Opaque), } } } @@ -2302,75 +2200,6 @@ fn pat_constructor<'tcx>( } } -// checks whether a constant is equal to a user-written slice pattern. Only supports byte slices, -// meaning all other types will compare unequal and thus equal patterns often do not cause the -// second pattern to lint about unreachable match arms. -fn slice_pat_covered_by_const<'tcx>( - tcx: TyCtxt<'tcx>, - _span: Span, - const_val: &'tcx ty::Const<'tcx>, - prefix: &[Pat<'tcx>], - slice: &Option<Pat<'tcx>>, - suffix: &[Pat<'tcx>], - param_env: ty::ParamEnv<'tcx>, -) -> Result<bool, ErrorReported> { - let const_val_val = if let ty::ConstKind::Value(val) = const_val.val { - val - } else { - bug!( - "slice_pat_covered_by_const: {:#?}, {:#?}, {:#?}, {:#?}", - const_val, - prefix, - slice, - suffix, - ) - }; - - let data: &[u8] = match (const_val_val, &const_val.ty.kind()) { - (ConstValue::ByRef { offset, alloc, .. }, ty::Array(t, n)) => { - assert_eq!(*t, tcx.types.u8); - let n = n.eval_usize(tcx, param_env); - let ptr = Pointer::new(AllocId(0), offset); - alloc.get_bytes(&tcx, ptr, Size::from_bytes(n)).unwrap() - } - (ConstValue::Slice { data, start, end }, ty::Slice(t)) => { - assert_eq!(*t, tcx.types.u8); - let ptr = Pointer::new(AllocId(0), Size::from_bytes(start)); - data.get_bytes(&tcx, ptr, Size::from_bytes(end - start)).unwrap() - } - // FIXME(oli-obk): create a way to extract fat pointers from ByRef - (_, ty::Slice(_)) => return Ok(false), - _ => bug!( - "slice_pat_covered_by_const: {:#?}, {:#?}, {:#?}, {:#?}", - const_val, - prefix, - slice, - suffix, - ), - }; - - let pat_len = prefix.len() + suffix.len(); - if data.len() < pat_len || (slice.is_none() && data.len() > pat_len) { - return Ok(false); - } - - for (ch, pat) in data[..prefix.len()] - .iter() - .zip(prefix) - .chain(data[data.len() - suffix.len()..].iter().zip(suffix)) - { - if let box PatKind::Constant { value } = pat.kind { - let b = value.eval_bits(tcx, param_env, pat.ty); - assert_eq!(b as u8 as u128, b); - if b as u8 != *ch { - return Ok(false); - } - } - } - - Ok(true) -} - /// For exhaustive integer matching, some constructors are grouped within other constructors /// (namely integer typed values are grouped within ranges). However, when specialising these /// constructors, we want to be specialising for the underlying constructors (the integers), not @@ -2668,35 +2497,6 @@ fn lint_overlapping_patterns<'tcx>( } } -fn constructor_covered_by_range<'tcx>( - tcx: TyCtxt<'tcx>, - param_env: ty::ParamEnv<'tcx>, - ctor: &Constructor<'tcx>, - pat: &Pat<'tcx>, -) -> Option<()> { - if let Single = ctor { - return Some(()); - } - - let (pat_from, pat_to, pat_end, ty) = match *pat.kind { - PatKind::Constant { value } => (value, value, RangeEnd::Included, value.ty), - PatKind::Range(PatRange { lo, hi, end }) => (lo, hi, end, lo.ty), - _ => bug!("`constructor_covered_by_range` called with {:?}", pat), - }; - let (ctor_from, ctor_to, ctor_end) = match *ctor { - ConstantValue(value) => (value, value, RangeEnd::Included), - FloatRange(from, to, ctor_end) => (from, to, ctor_end), - _ => bug!("`constructor_covered_by_range` called with {:?}", ctor), - }; - trace!("constructor_covered_by_range {:#?}, {:#?}, {:#?}, {}", ctor, pat_from, pat_to, ty); - - let to = compare_const_vals(tcx, ctor_to, pat_to, param_env, ty)?; - let from = compare_const_vals(tcx, ctor_from, pat_from, param_env, ty)?; - let intersects = (from == Ordering::Greater || from == Ordering::Equal) - && (to == Ordering::Less || (pat_end == ctor_end && to == Ordering::Equal)); - if intersects { Some(()) } else { None } -} - /// This is the main specialization step. It expands the pattern /// into `arity` patterns based on the constructor. For most patterns, the step is trivial, /// for instance tuple patterns are flattened and box patterns expand into their inner pattern. @@ -2713,15 +2513,43 @@ fn specialize_one_pattern<'p, 'tcx>( pat: &'p Pat<'tcx>, constructor: &Constructor<'tcx>, ctor_wild_subpatterns: &Fields<'p, 'tcx>, + is_its_own_ctor: bool, // Whether `ctor` is known to be derived from `pat` ) -> Option<Fields<'p, 'tcx>> { if let NonExhaustive = constructor { - // Only a wildcard pattern can match the special extra constructor + // Only a wildcard pattern can match the special extra constructor. if !pat.is_wildcard() { return None; } return Some(Fields::empty()); } + if let Opaque = constructor { + // Only a wildcard pattern can match an opaque constant, unless we're specializing the + // value against its own constructor. That happens when we call + // `v.specialize_constructor(ctor)` with `ctor` obtained from `pat_constructor(v.head())`. + // For example, in the following match, when we are dealing with the third branch, we will + // specialize with an `Opaque` ctor. We want to ignore the second branch because opaque + // constants should not be inspected, but we don't want to ignore the current (third) + // branch, as that would cause us to always conclude that such a branch is unreachable. + // ```rust + // #[derive(PartialEq)] + // struct Foo(i32); + // impl Eq for Foo {} + // const FOO: Foo = Foo(42); + // + // match (Foo(0), true) { + // (_, true) => {} + // (FOO, true) => {} + // (FOO, false) => {} + // } + // ``` + if is_its_own_ctor || pat.is_wildcard() { + return Some(Fields::empty()); + } else { + return None; + } + } + let result = match *pat.kind { PatKind::AscribeUserType { .. } => bug!(), // Handled by `expand_pattern` @@ -2741,93 +2569,52 @@ fn specialize_one_pattern<'p, 'tcx>( PatKind::Deref { ref subpattern } => Some(Fields::from_single_pattern(subpattern)), - PatKind::Constant { value } if constructor.is_slice() => { - // We extract an `Option` for the pointer because slices of zero - // elements don't necessarily point to memory, they are usually - // just integers. The only time they should be pointing to memory - // is when they are subslices of nonzero slices. - let (alloc, offset, n, ty) = match value.ty.kind() { - ty::Array(t, n) => { - let n = n.eval_usize(cx.tcx, cx.param_env); - // Shortcut for `n == 0` where no matter what `alloc` and `offset` we produce, - // the result would be exactly what we early return here. - if n == 0 { - if ctor_wild_subpatterns.len() as u64 != n { - return None; - } - return Some(Fields::empty()); - } - match value.val { - ty::ConstKind::Value(ConstValue::ByRef { offset, alloc, .. }) => { - (Cow::Borrowed(alloc), offset, n, t) - } - _ => span_bug!(pat.span, "array pattern is {:?}", value,), + PatKind::Constant { .. } | PatKind::Range { .. } => { + match constructor { + IntRange(ctor) => { + let pat = IntRange::from_pat(cx.tcx, cx.param_env, pat)?; + ctor.intersection(cx.tcx, &pat)?; + // Constructor splitting should ensure that all intersections we encounter + // are actually inclusions. + assert!(ctor.is_subrange(&pat)); + } + FloatRange(ctor_from, ctor_to, ctor_end) => { + let (pat_from, pat_to, pat_end, ty) = match *pat.kind { + PatKind::Constant { value } => (value, value, RangeEnd::Included, value.ty), + PatKind::Range(PatRange { lo, hi, end }) => (lo, hi, end, lo.ty), + _ => unreachable!(), // This is ensured by the branch we're in + }; + let to = compare_const_vals(cx.tcx, ctor_to, pat_to, cx.param_env, ty)?; + let from = compare_const_vals(cx.tcx, ctor_from, pat_from, cx.param_env, ty)?; + let intersects = (from == Ordering::Greater || from == Ordering::Equal) + && (to == Ordering::Less + || (pat_end == *ctor_end && to == Ordering::Equal)); + if !intersects { + return None; } } - ty::Slice(t) => { - match value.val { - ty::ConstKind::Value(ConstValue::Slice { data, start, end }) => { - let offset = Size::from_bytes(start); - let n = (end - start) as u64; - (Cow::Borrowed(data), offset, n, t) - } - ty::ConstKind::Value(ConstValue::ByRef { .. }) => { - // FIXME(oli-obk): implement `deref` for `ConstValue` - return None; - } + Str(ctor_value) => { + let pat_value = match *pat.kind { + PatKind::Constant { value } => value, _ => span_bug!( pat.span, - "slice pattern constant must be scalar pair but is {:?}", - value, + "unexpected range pattern {:?} for constant value ctor", + pat ), + }; + + // FIXME: there's probably a more direct way of comparing for equality + if compare_const_vals(cx.tcx, ctor_value, pat_value, cx.param_env, pat.ty)? + != Ordering::Equal + { + return None; } } - _ => span_bug!( - pat.span, - "unexpected const-val {:?} with ctor {:?}", - value, - constructor, - ), - }; - if ctor_wild_subpatterns.len() as u64 != n { - return None; - } - - // Convert a constant slice/array pattern to a list of patterns. - let layout = cx.tcx.layout_of(cx.param_env.and(ty)).ok()?; - let ptr = Pointer::new(AllocId(0), offset); - let pats = cx.pattern_arena.alloc_from_iter((0..n).filter_map(|i| { - let ptr = ptr.offset(layout.size * i, &cx.tcx).ok()?; - let scalar = alloc.read_scalar(&cx.tcx, ptr, layout.size).ok()?; - let scalar = scalar.check_init().ok()?; - let value = ty::Const::from_scalar(cx.tcx, scalar, ty); - let pattern = Pat { ty, span: pat.span, kind: box PatKind::Constant { value } }; - Some(pattern) - })); - // Ensure none of the dereferences failed. - if pats.len() as u64 != n { - return None; - } - Some(Fields::from_slice_unfiltered(pats)) - } - - PatKind::Constant { .. } | PatKind::Range { .. } => { - // If the constructor is a: - // - Single value: add a row if the pattern contains the constructor. - // - Range: add a row if the constructor intersects the pattern. - if let IntRange(ctor) = constructor { - let pat = IntRange::from_pat(cx.tcx, cx.param_env, pat)?; - ctor.intersection(cx.tcx, &pat)?; - // Constructor splitting should ensure that all intersections we encounter - // are actually inclusions. - assert!(ctor.is_subrange(&pat)); - } else { - // Fallback for non-ranges and ranges that involve - // floating-point numbers, which are not conveniently handled - // by `IntRange`. For these cases, the constructor may not be a - // range so intersection actually devolves into being covered - // by the pattern. - constructor_covered_by_range(cx.tcx, cx.param_env, constructor, pat)?; + _ => { + // If we reach here, we must be trying to inspect an opaque constant. Thus we skip + // the row. + return None; + } } Some(Fields::empty()) } @@ -2850,21 +2637,6 @@ fn specialize_one_pattern<'p, 'tcx>( let suffix = suffix.iter().enumerate().map(|(i, p)| (arity - suffix.len() + i, p)); Some(ctor_wild_subpatterns.replace_fields_indexed(prefix.chain(suffix))) } - ConstantValue(cv) => { - match slice_pat_covered_by_const( - cx.tcx, - pat.span, - cv, - prefix, - slice, - suffix, - cx.param_env, - ) { - Ok(true) => Some(Fields::empty()), - Ok(false) => None, - Err(ErrorReported) => None, - } - } _ => span_bug!(pat.span, "unexpected ctor {:?} for slice pat", constructor), }, diff --git a/compiler/rustc_mir_build/src/thir/pattern/check_match.rs b/compiler/rustc_mir_build/src/thir/pattern/check_match.rs index 69de7c7e2ee..30b700a1d4f 100644 --- a/compiler/rustc_mir_build/src/thir/pattern/check_match.rs +++ b/compiler/rustc_mir_build/src/thir/pattern/check_match.rs @@ -137,7 +137,7 @@ impl<'tcx> MatchVisitor<'_, 'tcx> { patcx.include_lint_checks(); let pattern = patcx.lower_pattern(pat); let pattern_ty = pattern.ty; - let pattern: &_ = cx.pattern_arena.alloc(expand_pattern(cx, pattern)); + let pattern: &_ = cx.pattern_arena.alloc(expand_pattern(pattern)); if !patcx.errors.is_empty() { *have_errors = true; patcx.report_inlining_errors(pat.span); diff --git a/compiler/rustc_mir_build/src/thir/pattern/const_to_pat.rs b/compiler/rustc_mir_build/src/thir/pattern/const_to_pat.rs index a203b3a1428..6370f8c375b 100644 --- a/compiler/rustc_mir_build/src/thir/pattern/const_to_pat.rs +++ b/compiler/rustc_mir_build/src/thir/pattern/const_to_pat.rs @@ -387,14 +387,16 @@ impl<'a, 'tcx> ConstToPat<'a, 'tcx> { // `&str` and `&[u8]` are represented as `ConstValue::Slice`, let's keep using this // optimization for now. ty::Str => PatKind::Constant { value: cv }, - ty::Slice(elem_ty) if elem_ty == tcx.types.u8 => PatKind::Constant { value: cv }, // `b"foo"` produces a `&[u8; 3]`, but you can't use constants of array type when // matching against references, you can only use byte string literals. - // FIXME: clean this up, likely by permitting array patterns when matching on slices - ty::Array(elem_ty, _) if elem_ty == tcx.types.u8 => PatKind::Constant { value: cv }, + // The typechecker has a special case for byte string literals, by treating them + // as slices. This means we turn `&[T; N]` constants into slice patterns, which + // has no negative effects on pattern matching, even if we're actually matching on + // arrays. + ty::Array(..) | // Cannot merge this with the catch all branch below, because the `const_deref` - // changes the type from slice to array, and slice patterns behave differently from - // array patterns. + // changes the type from slice to array, we need to keep the original type in the + // pattern. ty::Slice(..) => { let old = self.behind_reference.replace(true); let array = tcx.deref_const(self.param_env.and(cv)); diff --git a/compiler/rustc_mir_build/src/thir/pattern/mod.rs b/compiler/rustc_mir_build/src/thir/pattern/mod.rs index b05ddb3b464..25e18724341 100644 --- a/compiler/rustc_mir_build/src/thir/pattern/mod.rs +++ b/compiler/rustc_mir_build/src/thir/pattern/mod.rs @@ -158,6 +158,13 @@ crate enum PatKind<'tcx> { subpattern: Pat<'tcx>, }, + /// One of the following: + /// * `&str`, which will be handled as a string pattern and thus exhaustiveness + /// checking will detect if you use the same string twice in different patterns. + /// * integer, bool, char or float, which will be handled by exhaustivenes to cover exactly + /// its own value, similar to `&str`, but these values are much simpler. + /// * Opaque constants, that must not be matched structurally. So anything that does not derive + /// `PartialEq` and `Eq`. Constant { value: &'tcx ty::Const<'tcx>, }, diff --git a/compiler/rustc_query_system/src/query/config.rs b/compiler/rustc_query_system/src/query/config.rs index 6c9849e8708..0f0684b3547 100644 --- a/compiler/rustc_query_system/src/query/config.rs +++ b/compiler/rustc_query_system/src/query/config.rs @@ -5,7 +5,6 @@ use crate::dep_graph::SerializedDepNodeIndex; use crate::query::caches::QueryCache; use crate::query::plumbing::CycleError; use crate::query::{QueryContext, QueryState}; -use rustc_data_structures::profiling::ProfileCategory; use rustc_data_structures::fingerprint::Fingerprint; use std::borrow::Cow; @@ -14,7 +13,6 @@ use std::hash::Hash; pub trait QueryConfig { const NAME: &'static str; - const CATEGORY: ProfileCategory; type Key: Eq + Hash + Clone + Debug; type Value; diff --git a/compiler/rustc_resolve/src/macros.rs b/compiler/rustc_resolve/src/macros.rs index bea71389647..b5b281b93bc 100644 --- a/compiler/rustc_resolve/src/macros.rs +++ b/compiler/rustc_resolve/src/macros.rs @@ -19,7 +19,7 @@ use rustc_feature::is_builtin_attr_name; use rustc_hir::def::{self, DefKind, NonMacroAttrKind}; use rustc_hir::def_id; use rustc_middle::middle::stability; -use rustc_middle::{span_bug, ty}; +use rustc_middle::ty; use rustc_session::lint::builtin::UNUSED_MACROS; use rustc_session::Session; use rustc_span::edition::Edition; @@ -885,11 +885,11 @@ impl<'a> Resolver<'a> { initial_res: Option<Res>, res: Res| { if let Some(initial_res) = initial_res { - if res != initial_res && res != Res::Err && this.ambiguity_errors.is_empty() { + if res != initial_res { // Make sure compilation does not succeed if preferred macro resolution // has changed after the macro had been expanded. In theory all such - // situations should be reported as ambiguity errors, so this is a bug. - span_bug!(span, "inconsistent resolution for a macro"); + // situations should be reported as errors, so this is a bug. + this.session.delay_span_bug(span, "inconsistent resolution for a macro"); } } else { // It's possible that the macro was unresolved (indeterminate) and silently diff --git a/compiler/rustc_span/src/symbol.rs b/compiler/rustc_span/src/symbol.rs index 9cf530d57c0..3133090575e 100644 --- a/compiler/rustc_span/src/symbol.rs +++ b/compiler/rustc_span/src/symbol.rs @@ -777,6 +777,7 @@ symbols! { panic_info, panic_location, panic_runtime, + panic_str, panic_unwind, param_attrs, parent_trait, diff --git a/compiler/rustc_trait_selection/src/traits/codegen.rs b/compiler/rustc_trait_selection/src/traits/codegen.rs index 05e6c4804ff..3cb6ec86261 100644 --- a/compiler/rustc_trait_selection/src/traits/codegen.rs +++ b/compiler/rustc_trait_selection/src/traits/codegen.rs @@ -121,7 +121,10 @@ where // contains unbound type parameters. It could be a slight // optimization to stop iterating early. if let Err(errors) = fulfill_cx.select_all_or_error(infcx) { - bug!("Encountered errors `{:?}` resolving bounds after type-checking", errors); + infcx.tcx.sess.delay_span_bug( + rustc_span::DUMMY_SP, + &format!("Encountered errors `{:?}` resolving bounds after type-checking", errors), + ); } let result = infcx.resolve_vars_if_possible(result); diff --git a/compiler/rustc_trait_selection/src/traits/const_evaluatable.rs b/compiler/rustc_trait_selection/src/traits/const_evaluatable.rs index 1e1eb16faf4..c79b2624f8c 100644 --- a/compiler/rustc_trait_selection/src/traits/const_evaluatable.rs +++ b/compiler/rustc_trait_selection/src/traits/const_evaluatable.rs @@ -223,11 +223,23 @@ impl AbstractConst<'tcx> { } } +#[derive(Debug, Clone, Copy, PartialEq, Eq)] +struct WorkNode<'tcx> { + node: Node<'tcx>, + span: Span, + used: bool, +} + struct AbstractConstBuilder<'a, 'tcx> { tcx: TyCtxt<'tcx>, body: &'a mir::Body<'tcx>, /// The current WIP node tree. - nodes: IndexVec<NodeId, Node<'tcx>>, + /// + /// We require all nodes to be used in the final abstract const, + /// so we store this here. Note that we also consider nodes as used + /// if they are mentioned in an assert, so some used nodes are never + /// actually reachable by walking the [`AbstractConst`]. + nodes: IndexVec<NodeId, WorkNode<'tcx>>, locals: IndexVec<mir::Local, NodeId>, /// We only allow field accesses if they access /// the result of a checked operation. @@ -274,6 +286,27 @@ impl<'a, 'tcx> AbstractConstBuilder<'a, 'tcx> { Ok(Some(builder)) } + fn add_node(&mut self, node: Node<'tcx>, span: Span) -> NodeId { + // Mark used nodes. + match node { + Node::Leaf(_) => (), + Node::Binop(_, lhs, rhs) => { + self.nodes[lhs].used = true; + self.nodes[rhs].used = true; + } + Node::UnaryOp(_, input) => { + self.nodes[input].used = true; + } + Node::FunctionCall(func, nodes) => { + self.nodes[func].used = true; + nodes.iter().for_each(|&n| self.nodes[n].used = true); + } + } + + // Nodes start as unused. + self.nodes.push(WorkNode { node, span, used: false }) + } + fn place_to_local( &mut self, span: Span, @@ -311,7 +344,7 @@ impl<'a, 'tcx> AbstractConstBuilder<'a, 'tcx> { let local = self.place_to_local(span, p)?; Ok(self.locals[local]) } - mir::Operand::Constant(ct) => Ok(self.nodes.push(Node::Leaf(ct.literal))), + mir::Operand::Constant(ct) => Ok(self.add_node(Node::Leaf(ct.literal), span)), } } @@ -336,19 +369,19 @@ impl<'a, 'tcx> AbstractConstBuilder<'a, 'tcx> { fn build_statement(&mut self, stmt: &mir::Statement<'tcx>) -> Result<(), ErrorReported> { debug!("AbstractConstBuilder: stmt={:?}", stmt); + let span = stmt.source_info.span; match stmt.kind { StatementKind::Assign(box (ref place, ref rvalue)) => { - let local = self.place_to_local(stmt.source_info.span, place)?; + let local = self.place_to_local(span, place)?; match *rvalue { Rvalue::Use(ref operand) => { - self.locals[local] = - self.operand_to_node(stmt.source_info.span, operand)?; + self.locals[local] = self.operand_to_node(span, operand)?; Ok(()) } Rvalue::BinaryOp(op, ref lhs, ref rhs) if Self::check_binop(op) => { - let lhs = self.operand_to_node(stmt.source_info.span, lhs)?; - let rhs = self.operand_to_node(stmt.source_info.span, rhs)?; - self.locals[local] = self.nodes.push(Node::Binop(op, lhs, rhs)); + let lhs = self.operand_to_node(span, lhs)?; + let rhs = self.operand_to_node(span, rhs)?; + self.locals[local] = self.add_node(Node::Binop(op, lhs, rhs), span); if op.is_checkable() { bug!("unexpected unchecked checkable binary operation"); } else { @@ -356,18 +389,18 @@ impl<'a, 'tcx> AbstractConstBuilder<'a, 'tcx> { } } Rvalue::CheckedBinaryOp(op, ref lhs, ref rhs) if Self::check_binop(op) => { - let lhs = self.operand_to_node(stmt.source_info.span, lhs)?; - let rhs = self.operand_to_node(stmt.source_info.span, rhs)?; - self.locals[local] = self.nodes.push(Node::Binop(op, lhs, rhs)); + let lhs = self.operand_to_node(span, lhs)?; + let rhs = self.operand_to_node(span, rhs)?; + self.locals[local] = self.add_node(Node::Binop(op, lhs, rhs), span); self.checked_op_locals.insert(local); Ok(()) } Rvalue::UnaryOp(op, ref operand) if Self::check_unop(op) => { - let operand = self.operand_to_node(stmt.source_info.span, operand)?; - self.locals[local] = self.nodes.push(Node::UnaryOp(op, operand)); + let operand = self.operand_to_node(span, operand)?; + self.locals[local] = self.add_node(Node::UnaryOp(op, operand), span); Ok(()) } - _ => self.error(Some(stmt.source_info.span), "unsupported rvalue")?, + _ => self.error(Some(span), "unsupported rvalue")?, } } // These are not actually relevant for us here, so we can ignore them. @@ -415,13 +448,9 @@ impl<'a, 'tcx> AbstractConstBuilder<'a, 'tcx> { .map(|arg| self.operand_to_node(terminator.source_info.span, arg)) .collect::<Result<Vec<NodeId>, _>>()?, ); - self.locals[local] = self.nodes.push(Node::FunctionCall(func, args)); + self.locals[local] = self.add_node(Node::FunctionCall(func, args), fn_span); Ok(Some(target)) } - // We only allow asserts for checked operations. - // - // These asserts seem to all have the form `!_local.0` so - // we only allow exactly that. TerminatorKind::Assert { ref cond, expected: false, target, .. } => { let p = match cond { mir::Operand::Copy(p) | mir::Operand::Move(p) => p, @@ -430,7 +459,15 @@ impl<'a, 'tcx> AbstractConstBuilder<'a, 'tcx> { const ONE_FIELD: mir::Field = mir::Field::from_usize(1); debug!("proj: {:?}", p.projection); - if let &[mir::ProjectionElem::Field(ONE_FIELD, _)] = p.projection.as_ref() { + if let Some(p) = p.as_local() { + debug_assert!(!self.checked_op_locals.contains(p)); + // Mark locals directly used in asserts as used. + // + // This is needed because division does not use `CheckedBinop` but instead + // adds an explicit assert for `divisor != 0`. + self.nodes[self.locals[p]].used = true; + return Ok(Some(target)); + } else if let &[mir::ProjectionElem::Field(ONE_FIELD, _)] = p.projection.as_ref() { // Only allow asserts checking the result of a checked operation. if self.checked_op_locals.contains(p.local) { return Ok(Some(target)); @@ -457,7 +494,13 @@ impl<'a, 'tcx> AbstractConstBuilder<'a, 'tcx> { if let Some(next) = self.build_terminator(block.terminator())? { block = &self.body.basic_blocks()[next]; } else { - return Ok(self.tcx.arena.alloc_from_iter(self.nodes)); + assert_eq!(self.locals[mir::RETURN_PLACE], self.nodes.last().unwrap()); + self.nodes[self.locals[mir::RETURN_PLACE]].used = true; + if let Some(&unused) = self.nodes.iter().find(|n| !n.used) { + self.error(Some(unused.span), "dead code")?; + } + + return Ok(self.tcx.arena.alloc_from_iter(self.nodes.into_iter().map(|n| n.node))); } } } |