diff --git a/crates/hir-ty/src/mir.rs b/crates/hir-ty/src/mir.rs index 747ca54858c8..2e6fe59d3bd8 100644 --- a/crates/hir-ty/src/mir.rs +++ b/crates/hir-ty/src/mir.rs @@ -269,6 +269,10 @@ impl ProjectionStore { impl ProjectionId { pub const EMPTY: ProjectionId = ProjectionId(0); + pub fn is_empty(self) -> bool { + self == ProjectionId::EMPTY + } + pub fn lookup(self, store: &ProjectionStore) -> &[PlaceElem] { store.id_to_proj.get(&self).unwrap() } @@ -1069,6 +1073,10 @@ pub struct MirBody { } impl MirBody { + pub fn local_to_binding_map(&self) -> ArenaMap { + self.binding_locals.iter().map(|(it, y)| (*y, it)).collect() + } + fn walk_places(&mut self, mut f: impl FnMut(&mut Place, &mut ProjectionStore)) { fn for_operand( op: &mut Operand, @@ -1188,3 +1196,9 @@ pub enum MirSpan { } impl_from!(ExprId, PatId for MirSpan); + +impl From<&ExprId> for MirSpan { + fn from(value: &ExprId) -> Self { + (*value).into() + } +} diff --git a/crates/hir-ty/src/mir/lower.rs b/crates/hir-ty/src/mir/lower.rs index 9905d522146c..922aee011cf3 100644 --- a/crates/hir-ty/src/mir/lower.rs +++ b/crates/hir-ty/src/mir/lower.rs @@ -105,9 +105,14 @@ pub enum MirLowerError { /// A token to ensuring that each drop scope is popped at most once, thanks to the compiler that checks moves. struct DropScopeToken; impl DropScopeToken { - fn pop_and_drop(self, ctx: &mut MirLowerCtx<'_>, current: BasicBlockId) -> BasicBlockId { + fn pop_and_drop( + self, + ctx: &mut MirLowerCtx<'_>, + current: BasicBlockId, + span: MirSpan, + ) -> BasicBlockId { std::mem::forget(self); - ctx.pop_drop_scope_internal(current) + ctx.pop_drop_scope_internal(current, span) } /// It is useful when we want a drop scope is syntaxically closed, but we don't want to execute any drop @@ -582,7 +587,7 @@ impl<'ctx> MirLowerCtx<'ctx> { self.lower_loop(current, place, *label, expr_id.into(), |this, begin| { let scope = this.push_drop_scope(); if let Some((_, mut current)) = this.lower_expr_as_place(begin, *body, true)? { - current = scope.pop_and_drop(this, current); + current = scope.pop_and_drop(this, current, body.into()); this.set_goto(current, begin, expr_id.into()); } else { scope.pop_assume_dropped(this); @@ -720,7 +725,8 @@ impl<'ctx> MirLowerCtx<'ctx> { .ok_or(MirLowerError::ContinueWithoutLoop)?, }; let begin = loop_data.begin; - current = self.drop_until_scope(loop_data.drop_scope_index, current); + current = + self.drop_until_scope(loop_data.drop_scope_index, current, expr_id.into()); self.set_goto(current, begin, expr_id.into()); Ok(None) } @@ -759,7 +765,7 @@ impl<'ctx> MirLowerCtx<'ctx> { self.current_loop_blocks.as_ref().unwrap().drop_scope_index, ), }; - current = self.drop_until_scope(drop_scope, current); + current = self.drop_until_scope(drop_scope, current, expr_id.into()); self.set_goto(current, end, expr_id.into()); Ok(None) } @@ -773,7 +779,7 @@ impl<'ctx> MirLowerCtx<'ctx> { return Ok(None); } } - current = self.drop_until_scope(0, current); + current = self.drop_until_scope(0, current, expr_id.into()); self.set_terminator(current, TerminatorKind::Return, expr_id.into()); Ok(None) } @@ -1782,7 +1788,7 @@ impl<'ctx> MirLowerCtx<'ctx> { return Ok(None); }; self.push_fake_read(c, p, expr.into()); - current = scope2.pop_and_drop(self, c); + current = scope2.pop_and_drop(self, c, expr.into()); } } } @@ -1793,7 +1799,7 @@ impl<'ctx> MirLowerCtx<'ctx> { }; current = c; } - current = scope.pop_and_drop(self, current); + current = scope.pop_and_drop(self, current, span); Ok(Some(current)) } @@ -1873,9 +1879,14 @@ impl<'ctx> MirLowerCtx<'ctx> { } } - fn drop_until_scope(&mut self, scope_index: usize, mut current: BasicBlockId) -> BasicBlockId { + fn drop_until_scope( + &mut self, + scope_index: usize, + mut current: BasicBlockId, + span: MirSpan, + ) -> BasicBlockId { for scope in self.drop_scopes[scope_index..].to_vec().iter().rev() { - self.emit_drop_and_storage_dead_for_scope(scope, &mut current); + self.emit_drop_and_storage_dead_for_scope(scope, &mut current, span); } current } @@ -1891,17 +1902,22 @@ impl<'ctx> MirLowerCtx<'ctx> { } /// Don't call directly - fn pop_drop_scope_internal(&mut self, mut current: BasicBlockId) -> BasicBlockId { + fn pop_drop_scope_internal( + &mut self, + mut current: BasicBlockId, + span: MirSpan, + ) -> BasicBlockId { let scope = self.drop_scopes.pop().unwrap(); - self.emit_drop_and_storage_dead_for_scope(&scope, &mut current); + self.emit_drop_and_storage_dead_for_scope(&scope, &mut current, span); current } fn pop_drop_scope_assert_finished( &mut self, mut current: BasicBlockId, + span: MirSpan, ) -> Result { - current = self.pop_drop_scope_internal(current); + current = self.pop_drop_scope_internal(current, span); if !self.drop_scopes.is_empty() { implementation_error!("Mismatched count between drop scope push and pops"); } @@ -1912,6 +1928,7 @@ impl<'ctx> MirLowerCtx<'ctx> { &mut self, scope: &DropScope, current: &mut Idx, + span: MirSpan, ) { for &l in scope.locals.iter().rev() { if !self.result.locals[l].ty.clone().is_copy(self.db, self.owner) { @@ -1919,13 +1936,10 @@ impl<'ctx> MirLowerCtx<'ctx> { self.set_terminator( prev, TerminatorKind::Drop { place: l.into(), target: *current, unwind: None }, - MirSpan::Unknown, + span, ); } - self.push_statement( - *current, - StatementKind::StorageDead(l).with_span(MirSpan::Unknown), - ); + self.push_statement(*current, StatementKind::StorageDead(l).with_span(span)); } } } @@ -2002,7 +2016,7 @@ pub fn mir_body_for_closure_query( |_| true, )?; if let Some(current) = ctx.lower_expr_to_place(*root, return_slot().into(), current)? { - let current = ctx.pop_drop_scope_assert_finished(current)?; + let current = ctx.pop_drop_scope_assert_finished(current, root.into())?; ctx.set_terminator(current, TerminatorKind::Return, (*root).into()); } let mut upvar_map: FxHashMap> = FxHashMap::default(); @@ -2146,7 +2160,7 @@ pub fn lower_to_mir( ctx.lower_params_and_bindings([].into_iter(), binding_picker)? }; if let Some(current) = ctx.lower_expr_to_place(root_expr, return_slot().into(), current)? { - let current = ctx.pop_drop_scope_assert_finished(current)?; + let current = ctx.pop_drop_scope_assert_finished(current, root_expr.into())?; ctx.set_terminator(current, TerminatorKind::Return, root_expr.into()); } Ok(ctx.result) diff --git a/crates/hir-ty/src/mir/pretty.rs b/crates/hir-ty/src/mir/pretty.rs index 6e42bee97f79..a91f90bc249e 100644 --- a/crates/hir-ty/src/mir/pretty.rs +++ b/crates/hir-ty/src/mir/pretty.rs @@ -145,7 +145,7 @@ impl<'a> MirPrettyCtx<'a> { let indent = mem::take(&mut self.indent); let mut ctx = MirPrettyCtx { body: &body, - local_to_binding: body.binding_locals.iter().map(|(it, y)| (*y, it)).collect(), + local_to_binding: body.local_to_binding_map(), result, indent, ..*self @@ -167,7 +167,7 @@ impl<'a> MirPrettyCtx<'a> { } fn new(body: &'a MirBody, hir_body: &'a Body, db: &'a dyn HirDatabase) -> Self { - let local_to_binding = body.binding_locals.iter().map(|(it, y)| (*y, it)).collect(); + let local_to_binding = body.local_to_binding_map(); MirPrettyCtx { body, db, diff --git a/crates/hir/src/lib.rs b/crates/hir/src/lib.rs index 920c88ccfbc7..908027a2026d 100644 --- a/crates/hir/src/lib.rs +++ b/crates/hir/src/lib.rs @@ -67,7 +67,7 @@ use hir_ty::{ known_const_to_ast, layout::{Layout as TyLayout, RustcEnumVariantIdx, RustcFieldIdx, TagEncoding}, method_resolution::{self, TyFingerprint}, - mir::{self, interpret_mir}, + mir::interpret_mir, primitive::UintTy, traits::FnTrait, AliasTy, CallableDefId, CallableSig, Canonical, CanonicalVarKinds, Cast, ClosureId, GenericArg, @@ -129,9 +129,10 @@ pub use { hir_ty::{ display::{ClosureStyle, HirDisplay, HirDisplayError, HirWrite}, layout::LayoutError, - mir::MirEvalError, PointerCast, Safety, }, + // FIXME: Properly encapsulate mir + hir_ty::{mir, Interner as ChalkTyInterner}, }; // These are negative re-exports: pub using these names is forbidden, they diff --git a/crates/ide/src/inlay_hints.rs b/crates/ide/src/inlay_hints.rs index 24f44ca06ffb..7ea9d4f1038b 100644 --- a/crates/ide/src/inlay_hints.rs +++ b/crates/ide/src/inlay_hints.rs @@ -31,6 +31,7 @@ mod discriminant; mod fn_lifetime_fn; mod implicit_static; mod param_name; +mod implicit_drop; #[derive(Clone, Debug, PartialEq, Eq)] pub struct InlayHintsConfig { @@ -45,6 +46,7 @@ pub struct InlayHintsConfig { pub closure_return_type_hints: ClosureReturnTypeHints, pub closure_capture_hints: bool, pub binding_mode_hints: bool, + pub implicit_drop_hints: bool, pub lifetime_elision_hints: LifetimeElisionHints, pub param_names_for_lifetime_elision_hints: bool, pub hide_named_constructor_hints: bool, @@ -124,6 +126,7 @@ pub enum InlayKind { Lifetime, Parameter, Type, + Drop, } #[derive(Debug)] @@ -503,7 +506,10 @@ fn hints( ast::Item(it) => match it { // FIXME: record impl lifetimes so they aren't being reused in assoc item lifetime inlay hints ast::Item::Impl(_) => None, - ast::Item::Fn(it) => fn_lifetime_fn::hints(hints, config, it), + ast::Item::Fn(it) => { + implicit_drop::hints(hints, sema, config, &it); + fn_lifetime_fn::hints(hints, config, it) + }, // static type elisions ast::Item::Static(it) => implicit_static::hints(hints, config, Either::Left(it)), ast::Item::Const(it) => implicit_static::hints(hints, config, Either::Right(it)), @@ -591,6 +597,7 @@ mod tests { max_length: None, closing_brace_hints_min_lines: None, fields_to_resolve: InlayFieldsToResolve::empty(), + implicit_drop_hints: false, }; pub(super) const TEST_CONFIG: InlayHintsConfig = InlayHintsConfig { type_hints: true, diff --git a/crates/ide/src/inlay_hints/implicit_drop.rs b/crates/ide/src/inlay_hints/implicit_drop.rs new file mode 100644 index 000000000000..60f1f3496f6c --- /dev/null +++ b/crates/ide/src/inlay_hints/implicit_drop.rs @@ -0,0 +1,204 @@ +//! Implementation of "implicit drop" inlay hints: +//! ```no_run +//! fn main() { +//! let x = vec![2]; +//! if some_condition() { +//! /* drop(x) */return; +//! } +//! } +//! ``` +use hir::{ + db::{DefDatabase as _, HirDatabase as _}, + mir::{MirSpan, TerminatorKind}, + ChalkTyInterner, DefWithBody, Semantics, +}; +use ide_db::{base_db::FileRange, RootDatabase}; + +use syntax::{ + ast::{self, AstNode}, + match_ast, +}; + +use crate::{InlayHint, InlayHintLabel, InlayHintPosition, InlayHintsConfig, InlayKind}; + +pub(super) fn hints( + acc: &mut Vec, + sema: &Semantics<'_, RootDatabase>, + config: &InlayHintsConfig, + def: &ast::Fn, +) -> Option<()> { + if !config.implicit_drop_hints { + return None; + } + + let def = sema.to_def(def)?; + let def: DefWithBody = def.into(); + + let source_map = sema.db.body_with_source_map(def.into()).1; + + let hir = sema.db.body(def.into()); + let mir = sema.db.mir_body(def.into()).ok()?; + + let local_to_binding = mir.local_to_binding_map(); + + for (_, bb) in mir.basic_blocks.iter() { + let terminator = bb.terminator.as_ref()?; + if let TerminatorKind::Drop { place, .. } = terminator.kind { + if !place.projection.is_empty() { + continue; // Ignore complex cases for now + } + if mir.locals[place.local].ty.adt_id(ChalkTyInterner).is_none() { + continue; // Arguably only ADTs have significant drop impls + } + let Some(binding) = local_to_binding.get(place.local) else { + continue; // Ignore temporary values + }; + let range = match terminator.span { + MirSpan::ExprId(e) => match source_map.expr_syntax(e) { + Ok(s) => { + let root = &s.file_syntax(sema.db); + let expr = s.value.to_node(root); + let expr = expr.syntax(); + match_ast! { + match expr { + ast::BlockExpr(x) => x.stmt_list().and_then(|x| x.r_curly_token()).map(|x| x.text_range()).unwrap_or_else(|| expr.text_range()), + _ => expr.text_range(), + } + } + } + Err(_) => continue, + }, + MirSpan::PatId(p) => match source_map.pat_syntax(p) { + Ok(s) => s.value.text_range(), + Err(_) => continue, + }, + MirSpan::Unknown => continue, + }; + let binding = &hir.bindings[*binding]; + let binding_source = binding + .definitions + .first() + .and_then(|d| source_map.pat_syntax(*d).ok()) + .and_then(|d| { + Some(FileRange { file_id: d.file_id.file_id()?, range: d.value.text_range() }) + }); + let name = binding.name.to_smol_str(); + if name.starts_with(" Option<()> { + let x = X; + let t_opt = Some(2); + let t = t_opt?; + //^^^^^^ drop(x) + Some(()) + } + //^ drop(x) +"#, + ); + } + + #[test] + fn if_let() { + check_with_config( + ONLY_DROP_CONFIG, + r#" + struct X; + fn f() { + let x = X; + if let X = x { + let y = X; + } + //^ drop(y) + } + //^ drop(x) +"#, + ); + } +} diff --git a/crates/ide/src/static_index.rs b/crates/ide/src/static_index.rs index aabd26da289c..b54874d59f8b 100644 --- a/crates/ide/src/static_index.rs +++ b/crates/ide/src/static_index.rs @@ -118,6 +118,7 @@ impl StaticIndex<'_> { adjustment_hints: crate::AdjustmentHints::Never, adjustment_hints_mode: AdjustmentHintsMode::Prefix, adjustment_hints_hide_outside_unsafe: false, + implicit_drop_hints: false, hide_named_constructor_hints: false, hide_closure_initialization_hints: false, closure_style: hir::ClosureStyle::ImplFn, diff --git a/crates/rust-analyzer/src/cli/analysis_stats.rs b/crates/rust-analyzer/src/cli/analysis_stats.rs index 0f6539f224d7..b4debba38c97 100644 --- a/crates/rust-analyzer/src/cli/analysis_stats.rs +++ b/crates/rust-analyzer/src/cli/analysis_stats.rs @@ -783,6 +783,7 @@ impl flags::AnalysisStats { closure_return_type_hints: ide::ClosureReturnTypeHints::Always, closure_capture_hints: true, binding_mode_hints: true, + implicit_drop_hints: true, lifetime_elision_hints: ide::LifetimeElisionHints::Always, param_names_for_lifetime_elision_hints: true, hide_named_constructor_hints: false, diff --git a/crates/rust-analyzer/src/config.rs b/crates/rust-analyzer/src/config.rs index f28f6ffb8748..90d1d6b05559 100644 --- a/crates/rust-analyzer/src/config.rs +++ b/crates/rust-analyzer/src/config.rs @@ -381,6 +381,8 @@ config_data! { inlayHints_expressionAdjustmentHints_hideOutsideUnsafe: bool = "false", /// Whether to show inlay hints as postfix ops (`.*` instead of `*`, etc). inlayHints_expressionAdjustmentHints_mode: AdjustmentHintsModeDef = "\"prefix\"", + /// Whether to show implicit drop hints. + inlayHints_implicitDrops_enable: bool = "false", /// Whether to show inlay type hints for elided lifetimes in function signatures. inlayHints_lifetimeElisionHints_enable: LifetimeElisionDef = "\"never\"", /// Whether to prefer using parameter names as the name for elided lifetime hints if possible. @@ -1391,6 +1393,7 @@ impl Config { type_hints: self.data.inlayHints_typeHints_enable, parameter_hints: self.data.inlayHints_parameterHints_enable, chaining_hints: self.data.inlayHints_chainingHints_enable, + implicit_drop_hints: self.data.inlayHints_implicitDrops_enable, discriminant_hints: match self.data.inlayHints_discriminantHints_enable { DiscriminantHintsDef::Always => ide::DiscriminantHints::Always, DiscriminantHintsDef::Never => ide::DiscriminantHints::Never, diff --git a/crates/test-utils/src/minicore.rs b/crates/test-utils/src/minicore.rs index f2ca9d82ed0d..ba5c86db0e2e 100644 --- a/crates/test-utils/src/minicore.rs +++ b/crates/test-utils/src/minicore.rs @@ -1054,6 +1054,10 @@ pub mod option { Some(T), } + // region:copy + impl Copy for Option {} + // endregion:copy + impl Option { pub const fn unwrap(self) -> T { match self { diff --git a/docs/user/generated_config.adoc b/docs/user/generated_config.adoc index 7091ea1ce9a7..8a2d08084435 100644 --- a/docs/user/generated_config.adoc +++ b/docs/user/generated_config.adoc @@ -564,6 +564,11 @@ Whether to hide inlay hints for type adjustments outside of `unsafe` blocks. -- Whether to show inlay hints as postfix ops (`.*` instead of `*`, etc). -- +[[rust-analyzer.inlayHints.implicitDrops.enable]]rust-analyzer.inlayHints.implicitDrops.enable (default: `false`):: ++ +-- +Whether to show implicit drop hints. +-- [[rust-analyzer.inlayHints.lifetimeElisionHints.enable]]rust-analyzer.inlayHints.lifetimeElisionHints.enable (default: `"never"`):: + -- diff --git a/editors/code/package.json b/editors/code/package.json index c43f2b964fde..cfaf42132775 100644 --- a/editors/code/package.json +++ b/editors/code/package.json @@ -1264,6 +1264,11 @@ "Show prefix or postfix depending on which uses less parenthesis, preferring postfix." ] }, + "rust-analyzer.inlayHints.implicitDrops.enable": { + "markdownDescription": "Whether to show implicit drop hints.", + "default": false, + "type": "boolean" + }, "rust-analyzer.inlayHints.lifetimeElisionHints.enable": { "markdownDescription": "Whether to show inlay type hints for elided lifetimes in function signatures.", "default": "never",