From c60fb12a35a8cc541068d12fd00cd676a2c92580 Mon Sep 17 00:00:00 2001 From: Maybe Waffle Date: Mon, 21 Nov 2022 12:47:42 +0000 Subject: [PATCH] `thir`: Add `Become` expression kind --- compiler/rustc_middle/src/thir.rs | 4 ++++ compiler/rustc_middle/src/thir/visit.rs | 1 + compiler/rustc_mir_build/src/build/expr/as_place.rs | 1 + compiler/rustc_mir_build/src/build/expr/as_rvalue.rs | 1 + compiler/rustc_mir_build/src/build/expr/category.rs | 3 ++- compiler/rustc_mir_build/src/build/expr/into.rs | 5 ++++- compiler/rustc_mir_build/src/build/expr/stmt.rs | 7 +++++++ compiler/rustc_mir_build/src/check_unsafety.rs | 1 + compiler/rustc_mir_build/src/thir/cx/expr.rs | 8 ++------ compiler/rustc_mir_build/src/thir/print.rs | 6 ++++++ compiler/rustc_ty_utils/src/consts.rs | 4 +++- 11 files changed, 32 insertions(+), 9 deletions(-) diff --git a/compiler/rustc_middle/src/thir.rs b/compiler/rustc_middle/src/thir.rs index 813e109c41e14..0f3ad6d0151d1 100644 --- a/compiler/rustc_middle/src/thir.rs +++ b/compiler/rustc_middle/src/thir.rs @@ -410,6 +410,10 @@ pub enum ExprKind<'tcx> { Return { value: Option, }, + /// A `become` expression. + Become { + value: ExprId, + }, /// An inline `const` block, e.g. `const {}`. ConstBlock { did: DefId, diff --git a/compiler/rustc_middle/src/thir/visit.rs b/compiler/rustc_middle/src/thir/visit.rs index 5c7ec31cf93d3..9cc07677e0e36 100644 --- a/compiler/rustc_middle/src/thir/visit.rs +++ b/compiler/rustc_middle/src/thir/visit.rs @@ -100,6 +100,7 @@ pub fn walk_expr<'a, 'tcx: 'a, V: Visitor<'a, 'tcx>>(visitor: &mut V, expr: &Exp visitor.visit_expr(&visitor.thir()[value]) } } + Become { value } => visitor.visit_expr(&visitor.thir()[value]), ConstBlock { did: _, substs: _ } => {} Repeat { value, count: _ } => { visitor.visit_expr(&visitor.thir()[value]); diff --git a/compiler/rustc_mir_build/src/build/expr/as_place.rs b/compiler/rustc_mir_build/src/build/expr/as_place.rs index 623bef5ff2dba..783f6e2085cb8 100644 --- a/compiler/rustc_mir_build/src/build/expr/as_place.rs +++ b/compiler/rustc_mir_build/src/build/expr/as_place.rs @@ -549,6 +549,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> { | ExprKind::Break { .. } | ExprKind::Continue { .. } | ExprKind::Return { .. } + | ExprKind::Become { .. } | ExprKind::Literal { .. } | ExprKind::NamedConst { .. } | ExprKind::NonHirLiteral { .. } diff --git a/compiler/rustc_mir_build/src/build/expr/as_rvalue.rs b/compiler/rustc_mir_build/src/build/expr/as_rvalue.rs index ec00f9a96be20..27b1b58d2e909 100644 --- a/compiler/rustc_mir_build/src/build/expr/as_rvalue.rs +++ b/compiler/rustc_mir_build/src/build/expr/as_rvalue.rs @@ -532,6 +532,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> { | ExprKind::Break { .. } | ExprKind::Continue { .. } | ExprKind::Return { .. } + | ExprKind::Become { .. } | ExprKind::InlineAsm { .. } | ExprKind::PlaceTypeAscription { .. } | ExprKind::ValueTypeAscription { .. } => { diff --git a/compiler/rustc_mir_build/src/build/expr/category.rs b/compiler/rustc_mir_build/src/build/expr/category.rs index d9aa461c19d40..2fe9cac637808 100644 --- a/compiler/rustc_mir_build/src/build/expr/category.rs +++ b/compiler/rustc_mir_build/src/build/expr/category.rs @@ -82,7 +82,8 @@ impl Category { | ExprKind::Block { .. } | ExprKind::Break { .. } | ExprKind::Continue { .. } - | ExprKind::Return { .. } => + | ExprKind::Return { .. } + | ExprKind::Become { .. } => // FIXME(#27840) these probably want their own // category, like "nonterminating" { diff --git a/compiler/rustc_mir_build/src/build/expr/into.rs b/compiler/rustc_mir_build/src/build/expr/into.rs index 731f3996244ca..91c464252f1cc 100644 --- a/compiler/rustc_mir_build/src/build/expr/into.rs +++ b/compiler/rustc_mir_build/src/build/expr/into.rs @@ -493,7 +493,10 @@ impl<'a, 'tcx> Builder<'a, 'tcx> { block.unit() } - ExprKind::Continue { .. } | ExprKind::Break { .. } | ExprKind::Return { .. } => { + ExprKind::Continue { .. } + | ExprKind::Break { .. } + | ExprKind::Return { .. } + | ExprKind::Become { .. } => { unpack!(block = this.stmt_expr(block, expr, None)); // No assign, as these have type `!`. block.unit() diff --git a/compiler/rustc_mir_build/src/build/expr/stmt.rs b/compiler/rustc_mir_build/src/build/expr/stmt.rs index ea5aeb67d8576..396f82c27cd86 100644 --- a/compiler/rustc_mir_build/src/build/expr/stmt.rs +++ b/compiler/rustc_mir_build/src/build/expr/stmt.rs @@ -99,6 +99,13 @@ impl<'a, 'tcx> Builder<'a, 'tcx> { BreakableTarget::Return, source_info, ), + // FIXME(explicit_tail_calls): properly lower tail calls here + ExprKind::Become { value } => this.break_scope( + block, + Some(&this.thir[value]), + BreakableTarget::Return, + source_info, + ), _ => { assert!( statement_scope.is_some(), diff --git a/compiler/rustc_mir_build/src/check_unsafety.rs b/compiler/rustc_mir_build/src/check_unsafety.rs index 4f3a574031dbc..105564b787428 100644 --- a/compiler/rustc_mir_build/src/check_unsafety.rs +++ b/compiler/rustc_mir_build/src/check_unsafety.rs @@ -316,6 +316,7 @@ impl<'a, 'tcx> Visitor<'a, 'tcx> for UnsafetyVisitor<'a, 'tcx> { | ExprKind::Closure { .. } | ExprKind::Continue { .. } | ExprKind::Return { .. } + | ExprKind::Become { .. } | ExprKind::Yield { .. } | ExprKind::Loop { .. } | ExprKind::Let { .. } diff --git a/compiler/rustc_mir_build/src/thir/cx/expr.rs b/compiler/rustc_mir_build/src/thir/cx/expr.rs index d33103b029e5b..791c10c1748d9 100644 --- a/compiler/rustc_mir_build/src/thir/cx/expr.rs +++ b/compiler/rustc_mir_build/src/thir/cx/expr.rs @@ -694,12 +694,8 @@ impl<'tcx> Cx<'tcx> { ExprKind::Repeat { value: self.mirror_expr(v), count: *count } } - hir::ExprKind::Ret(ref v) => ExprKind::Return { value: v.map(|v| self.mirror_expr(v)) }, - hir::ExprKind::Become(call) => { - // FIXME(explicit_tail_calls): use `ExprKind::Become` once we implemented it - // Temporary transform `become` into a `return`, so we can write tests for code before this stage - ExprKind::Return { value: Some(self.mirror_expr(call)) } - } + hir::ExprKind::Ret(v) => ExprKind::Return { value: v.map(|v| self.mirror_expr(v)) }, + hir::ExprKind::Become(call) => ExprKind::Become { value: self.mirror_expr(call) }, hir::ExprKind::Break(dest, ref value) => match dest.target_id { Ok(target_id) => ExprKind::Break { label: region::Scope { id: target_id.local_id, data: region::ScopeData::Node }, diff --git a/compiler/rustc_mir_build/src/thir/print.rs b/compiler/rustc_mir_build/src/thir/print.rs index b2f2a64e29c8c..0b6029bf3882e 100644 --- a/compiler/rustc_mir_build/src/thir/print.rs +++ b/compiler/rustc_mir_build/src/thir/print.rs @@ -421,6 +421,12 @@ impl<'a, 'tcx> ThirPrinter<'a, 'tcx> { print_indented!(self, "}", depth_lvl); } + Become { value } => { + print_indented!(self, "Become {", depth_lvl); + print_indented!(self, "value:", depth_lvl + 1); + self.print_expr(*value, depth_lvl + 2); + print_indented!(self, "}", depth_lvl); + } ConstBlock { did, substs } => { print_indented!(self, "ConstBlock {", depth_lvl); print_indented!(self, format!("did: {:?}", did), depth_lvl + 1); diff --git a/compiler/rustc_ty_utils/src/consts.rs b/compiler/rustc_ty_utils/src/consts.rs index 387adda8f579f..d79ed2205704d 100644 --- a/compiler/rustc_ty_utils/src/consts.rs +++ b/compiler/rustc_ty_utils/src/consts.rs @@ -241,7 +241,8 @@ fn recurse_build<'tcx>( ExprKind::Assign { .. } | ExprKind::AssignOp { .. } => { error(GenericConstantTooComplexSub::AssignNotSupported(node.span))? } - ExprKind::Closure { .. } | ExprKind::Return { .. } => { + // FIXME(explicit_tail_calls): maybe get `become` a new error + ExprKind::Closure { .. } | ExprKind::Return { .. } | ExprKind::Become { .. } => { error(GenericConstantTooComplexSub::ClosureAndReturnNotSupported(node.span))? } // let expressions imply control flow @@ -337,6 +338,7 @@ impl<'a, 'tcx> IsThirPolymorphic<'a, 'tcx> { | thir::ExprKind::Break { .. } | thir::ExprKind::Continue { .. } | thir::ExprKind::Return { .. } + | thir::ExprKind::Become { .. } | thir::ExprKind::Array { .. } | thir::ExprKind::Tuple { .. } | thir::ExprKind::Adt(_)