diff --git a/compiler/rustc_middle/src/query/mod.rs b/compiler/rustc_middle/src/query/mod.rs index e07b174bc6aaa..87af90d059b54 100644 --- a/compiler/rustc_middle/src/query/mod.rs +++ b/compiler/rustc_middle/src/query/mod.rs @@ -955,6 +955,7 @@ rustc_queries! { desc { "get a &core::panic::Location referring to a span" } } + // FIXME get rid of this with valtrees query lit_to_const( key: LitToConstInput<'tcx> ) -> Result, LitToConstError> { diff --git a/compiler/rustc_middle/src/thir.rs b/compiler/rustc_middle/src/thir.rs index 785d3ee770985..170a49124c656 100644 --- a/compiler/rustc_middle/src/thir.rs +++ b/compiler/rustc_middle/src/thir.rs @@ -369,7 +369,8 @@ pub enum ExprKind<'tcx> { }, /// An inline `const` block, e.g. `const {}`. ConstBlock { - value: Const<'tcx>, + did: DefId, + substs: SubstsRef<'tcx>, }, /// An array literal constructed from one repeated element, e.g. `[1; 5]`. Repeat { @@ -408,13 +409,25 @@ pub enum ExprKind<'tcx> { }, /// A literal. Literal { - literal: Const<'tcx>, + lit: &'tcx hir::Lit, + neg: bool, + }, + /// For literals that don't correspond to anything in the HIR + NonHirLiteral { + lit: ty::ScalarInt, + user_ty: Option>>, + }, + /// Associated constants and named constants + NamedConst { + def_id: DefId, + substs: SubstsRef<'tcx>, user_ty: Option>>, - /// The `DefId` of the `const` item this literal - /// was produced from, if this is not a user-written - /// literal value. - const_id: Option, }, + ConstParam { + param: ty::ParamConst, + def_id: DefId, + }, + // FIXME improve docs for `StaticRef` by distinguishing it from `NamedConst` /// A literal containing the address of a `static`. /// /// This is only distinguished from `Literal` so that we can register some @@ -439,6 +452,12 @@ pub enum ExprKind<'tcx> { }, } +impl<'tcx> ExprKind<'tcx> { + pub fn zero_sized_literal(user_ty: Option>>) -> Self { + ExprKind::NonHirLiteral { lit: ty::ScalarInt::ZST, user_ty } + } +} + /// Represents the association of a field identifier and an expression. /// /// This is used in struct constructors. diff --git a/compiler/rustc_middle/src/thir/visit.rs b/compiler/rustc_middle/src/thir/visit.rs index 1c472f38184ea..451fa46638771 100644 --- a/compiler/rustc_middle/src/thir/visit.rs +++ b/compiler/rustc_middle/src/thir/visit.rs @@ -1,7 +1,6 @@ use super::{ Arm, Block, Expr, ExprKind, Guard, InlineAsmOperand, Pat, PatKind, Stmt, StmtKind, Thir, }; -use rustc_middle::ty::Const; pub trait Visitor<'a, 'tcx: 'a>: Sized { fn thir(&self) -> &'a Thir<'tcx>; @@ -25,8 +24,6 @@ pub trait Visitor<'a, 'tcx: 'a>: Sized { fn visit_pat(&mut self, pat: &Pat<'tcx>) { walk_pat(self, pat); } - - fn visit_const(&mut self, _cnst: Const<'tcx>) {} } pub fn walk_expr<'a, 'tcx: 'a, V: Visitor<'a, 'tcx>>(visitor: &mut V, expr: &Expr<'tcx>) { @@ -93,10 +90,9 @@ pub fn walk_expr<'a, 'tcx: 'a, V: Visitor<'a, 'tcx>>(visitor: &mut V, expr: &Exp visitor.visit_expr(&visitor.thir()[value]) } } - ConstBlock { value } => visitor.visit_const(value), - Repeat { value, count } => { + ConstBlock { did: _, substs: _ } => {} + Repeat { value, count: _ } => { visitor.visit_expr(&visitor.thir()[value]); - visitor.visit_const(count); } Array { ref fields } | Tuple { ref fields } => { for &field in &**fields { @@ -122,7 +118,10 @@ pub fn walk_expr<'a, 'tcx: 'a, V: Visitor<'a, 'tcx>>(visitor: &mut V, expr: &Exp visitor.visit_expr(&visitor.thir()[source]) } Closure { closure_id: _, substs: _, upvars: _, movability: _, fake_reads: _ } => {} - Literal { literal, user_ty: _, const_id: _ } => visitor.visit_const(literal), + Literal { lit: _, neg: _ } => {} + NonHirLiteral { lit: _, user_ty: _ } => {} + NamedConst { def_id: _, substs: _, user_ty: _ } => {} + ConstParam { param: _, def_id: _ } => {} StaticRef { alloc_id: _, ty: _, def_id: _ } => {} InlineAsm { ref operands, template: _, options: _, line_spans: _ } => { for op in &**operands { @@ -209,11 +208,8 @@ pub fn walk_pat<'a, 'tcx: 'a, V: Visitor<'a, 'tcx>>(visitor: &mut V, pat: &Pat<' visitor.visit_pat(&subpattern.pattern); } } - Constant { value } => visitor.visit_const(*value), - Range(range) => { - visitor.visit_const(range.lo); - visitor.visit_const(range.hi); - } + Constant { value: _ } => {} + Range(_) => {} Slice { prefix, slice, suffix } | Array { prefix, slice, suffix } => { for subpattern in prefix { visitor.visit_pat(&subpattern); diff --git a/compiler/rustc_mir_build/src/build/expr/as_constant.rs b/compiler/rustc_mir_build/src/build/expr/as_constant.rs index 0c0b0f2bd05af..6856ded3498ee 100644 --- a/compiler/rustc_mir_build/src/build/expr/as_constant.rs +++ b/compiler/rustc_mir_build/src/build/expr/as_constant.rs @@ -1,22 +1,48 @@ //! See docs in build/expr/mod.rs use crate::build::Builder; -use rustc_middle::mir::interpret::{ConstValue, Scalar}; +use crate::thir::constant::parse_float; +use rustc_ast::ast; +use rustc_hir::def_id::DefId; +use rustc_middle::mir::interpret::{ + Allocation, ConstValue, LitToConstError, LitToConstInput, Scalar, +}; use rustc_middle::mir::*; use rustc_middle::thir::*; -use rustc_middle::ty::CanonicalUserTypeAnnotation; +use rustc_middle::ty::subst::SubstsRef; +use rustc_middle::ty::{self, CanonicalUserTypeAnnotation, Ty, TyCtxt}; +use rustc_target::abi::Size; impl<'a, 'tcx> Builder<'a, 'tcx> { /// Compile `expr`, yielding a compile-time constant. Assumes that /// `expr` is a valid compile-time constant! crate fn as_constant(&mut self, expr: &Expr<'tcx>) -> Constant<'tcx> { + let create_uneval_from_def_id = + |tcx: TyCtxt<'tcx>, def_id: DefId, ty: Ty<'tcx>, substs: SubstsRef<'tcx>| { + let uneval = ty::Unevaluated::new(ty::WithOptConstParam::unknown(def_id), substs); + tcx.mk_const(ty::ConstS { val: ty::ConstKind::Unevaluated(uneval), ty }) + }; + let this = self; + let tcx = this.tcx; let Expr { ty, temp_lifetime: _, span, ref kind } = *expr; match *kind { ExprKind::Scope { region_scope: _, lint_level: _, value } => { this.as_constant(&this.thir[value]) } - ExprKind::Literal { literal, user_ty, const_id: _ } => { + ExprKind::Literal { lit, neg } => { + let literal = + match lit_to_constant(tcx, LitToConstInput { lit: &lit.node, ty, neg }) { + Ok(c) => c, + Err(LitToConstError::Reported) => ConstantKind::Ty(tcx.const_error(ty)), + Err(LitToConstError::TypeError) => { + bug!("encountered type error in `lit_to_constant") + } + }; + + Constant { span, user_ty: None, literal: literal.into() } + } + ExprKind::NonHirLiteral { lit, user_ty } => { let user_ty = user_ty.map(|user_ty| { this.canonical_user_type_annotations.push(CanonicalUserTypeAnnotation { span, @@ -24,20 +50,92 @@ impl<'a, 'tcx> Builder<'a, 'tcx> { inferred_ty: ty, }) }); - assert_eq!(literal.ty(), ty); - Constant { span, user_ty, literal: literal.into() } + + let literal = ConstantKind::Val(ConstValue::Scalar(Scalar::Int(lit)), ty); + + Constant { span, user_ty: user_ty, literal } + } + ExprKind::NamedConst { def_id, substs, user_ty } => { + let user_ty = user_ty.map(|user_ty| { + this.canonical_user_type_annotations.push(CanonicalUserTypeAnnotation { + span, + user_ty, + inferred_ty: ty, + }) + }); + let literal = ConstantKind::Ty(create_uneval_from_def_id(tcx, def_id, ty, substs)); + + Constant { user_ty, span, literal } + } + ExprKind::ConstParam { param, def_id: _ } => { + let const_param = + tcx.mk_const(ty::ConstS { val: ty::ConstKind::Param(param), ty: expr.ty }); + let literal = ConstantKind::Ty(const_param); + + Constant { user_ty: None, span, literal } + } + ExprKind::ConstBlock { did: def_id, substs } => { + let literal = ConstantKind::Ty(create_uneval_from_def_id(tcx, def_id, ty, substs)); + + Constant { user_ty: None, span, literal } } ExprKind::StaticRef { alloc_id, ty, .. } => { - let const_val = - ConstValue::Scalar(Scalar::from_pointer(alloc_id.into(), &this.tcx)); + let const_val = ConstValue::Scalar(Scalar::from_pointer(alloc_id.into(), &tcx)); let literal = ConstantKind::Val(const_val, ty); Constant { span, user_ty: None, literal } } - ExprKind::ConstBlock { value } => { - Constant { span: span, user_ty: None, literal: value.into() } - } _ => span_bug!(span, "expression is not a valid constant {:?}", kind), } } } + +crate fn lit_to_constant<'tcx>( + tcx: TyCtxt<'tcx>, + lit_input: LitToConstInput<'tcx>, +) -> Result, LitToConstError> { + let LitToConstInput { lit, ty, neg } = lit_input; + let trunc = |n| { + let param_ty = ty::ParamEnv::reveal_all().and(ty); + let width = tcx.layout_of(param_ty).map_err(|_| LitToConstError::Reported)?.size; + trace!("trunc {} with size {} and shift {}", n, width.bits(), 128 - width.bits()); + let result = width.truncate(n); + trace!("trunc result: {}", result); + Ok(ConstValue::Scalar(Scalar::from_uint(result, width))) + }; + + let value = match (lit, &ty.kind()) { + (ast::LitKind::Str(s, _), ty::Ref(_, inner_ty, _)) if inner_ty.is_str() => { + let s = s.as_str(); + let allocation = Allocation::from_bytes_byte_aligned_immutable(s.as_bytes()); + let allocation = tcx.intern_const_alloc(allocation); + ConstValue::Slice { data: allocation, start: 0, end: s.len() } + } + (ast::LitKind::ByteStr(data), ty::Ref(_, inner_ty, _)) + if matches!(inner_ty.kind(), ty::Slice(_)) => + { + let allocation = Allocation::from_bytes_byte_aligned_immutable(data as &[u8]); + let allocation = tcx.intern_const_alloc(allocation); + ConstValue::Slice { data: allocation, start: 0, end: data.len() } + } + (ast::LitKind::ByteStr(data), ty::Ref(_, inner_ty, _)) if inner_ty.is_array() => { + let id = tcx.allocate_bytes(data); + ConstValue::Scalar(Scalar::from_pointer(id.into(), &tcx)) + } + (ast::LitKind::Byte(n), ty::Uint(ty::UintTy::U8)) => { + ConstValue::Scalar(Scalar::from_uint(*n, Size::from_bytes(1))) + } + (ast::LitKind::Int(n, _), ty::Uint(_)) | (ast::LitKind::Int(n, _), ty::Int(_)) => { + trunc(if neg { (*n as i128).overflowing_neg().0 as u128 } else { *n })? + } + (ast::LitKind::Float(n, _), ty::Float(fty)) => { + parse_float(*n, *fty, neg).ok_or(LitToConstError::Reported)? + } + (ast::LitKind::Bool(b), ty::Bool) => ConstValue::Scalar(Scalar::from_bool(*b)), + (ast::LitKind::Char(c), ty::Char) => ConstValue::Scalar(Scalar::from_char(*c)), + (ast::LitKind::Err(_), _) => return Err(LitToConstError::Reported), + _ => return Err(LitToConstError::TypeError), + }; + + Ok(ConstantKind::Val(value, ty)) +} 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 3b93d127d2c29..10d241ee24cf4 100644 --- a/compiler/rustc_mir_build/src/build/expr/as_place.rs +++ b/compiler/rustc_mir_build/src/build/expr/as_place.rs @@ -566,6 +566,9 @@ impl<'a, 'tcx> Builder<'a, 'tcx> { | ExprKind::Continue { .. } | ExprKind::Return { .. } | ExprKind::Literal { .. } + | ExprKind::NamedConst { .. } + | ExprKind::NonHirLiteral { .. } + | ExprKind::ConstParam { .. } | ExprKind::ConstBlock { .. } | ExprKind::StaticRef { .. } | ExprKind::InlineAsm { .. } 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 1dc49256a6a9f..3f8a1a3f79504 100644 --- a/compiler/rustc_mir_build/src/build/expr/as_rvalue.rs +++ b/compiler/rustc_mir_build/src/build/expr/as_rvalue.rs @@ -327,6 +327,9 @@ impl<'a, 'tcx> Builder<'a, 'tcx> { } ExprKind::Yield { .. } | ExprKind::Literal { .. } + | ExprKind::NamedConst { .. } + | ExprKind::NonHirLiteral { .. } + | ExprKind::ConstParam { .. } | ExprKind::ConstBlock { .. } | ExprKind::StaticRef { .. } | ExprKind::Block { .. } diff --git a/compiler/rustc_mir_build/src/build/expr/as_temp.rs b/compiler/rustc_mir_build/src/build/expr/as_temp.rs index 32373f1bef7b3..6067da2f69b48 100644 --- a/compiler/rustc_mir_build/src/build/expr/as_temp.rs +++ b/compiler/rustc_mir_build/src/build/expr/as_temp.rs @@ -70,7 +70,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> { local_decl.local_info = Some(Box::new(LocalInfo::StaticRef { def_id, is_thread_local: true })); } - ExprKind::Literal { const_id: Some(def_id), .. } => { + ExprKind::NamedConst { def_id, .. } | ExprKind::ConstParam { def_id, .. } => { local_decl.local_info = Some(Box::new(LocalInfo::ConstRef { def_id })); } _ => {} diff --git a/compiler/rustc_mir_build/src/build/expr/category.rs b/compiler/rustc_mir_build/src/build/expr/category.rs index d31f6ed93840a..bcece39c6206e 100644 --- a/compiler/rustc_mir_build/src/build/expr/category.rs +++ b/compiler/rustc_mir_build/src/build/expr/category.rs @@ -69,9 +69,12 @@ impl Category { | ExprKind::AssignOp { .. } | ExprKind::ThreadLocalRef(_) => Some(Category::Rvalue(RvalueFunc::AsRvalue)), - ExprKind::ConstBlock { .. } | ExprKind::Literal { .. } | ExprKind::StaticRef { .. } => { - Some(Category::Constant) - } + ExprKind::ConstBlock { .. } + | ExprKind::Literal { .. } + | ExprKind::NonHirLiteral { .. } + | ExprKind::ConstParam { .. } + | ExprKind::StaticRef { .. } + | ExprKind::NamedConst { .. } => Some(Category::Constant), ExprKind::Loop { .. } | ExprKind::Block { .. } diff --git a/compiler/rustc_mir_build/src/build/expr/into.rs b/compiler/rustc_mir_build/src/build/expr/into.rs index 8092f99931123..a8f623dbe4693 100644 --- a/compiler/rustc_mir_build/src/build/expr/into.rs +++ b/compiler/rustc_mir_build/src/build/expr/into.rs @@ -533,6 +533,9 @@ impl<'a, 'tcx> Builder<'a, 'tcx> { | ExprKind::Closure { .. } | ExprKind::ConstBlock { .. } | ExprKind::Literal { .. } + | ExprKind::NamedConst { .. } + | ExprKind::NonHirLiteral { .. } + | ExprKind::ConstParam { .. } | ExprKind::ThreadLocalRef(_) | ExprKind::StaticRef { .. } => { debug_assert!(match Category::of(&expr.kind).unwrap() { diff --git a/compiler/rustc_mir_build/src/build/expr/mod.rs b/compiler/rustc_mir_build/src/build/expr/mod.rs index 7c1a592f5515e..7be435cda7db3 100644 --- a/compiler/rustc_mir_build/src/build/expr/mod.rs +++ b/compiler/rustc_mir_build/src/build/expr/mod.rs @@ -60,7 +60,7 @@ //! basically the point where the "by value" operations are bridged //! over to the "by reference" mode (`as_place`). -mod as_constant; +crate mod as_constant; mod as_operand; pub mod as_place; mod as_rvalue; diff --git a/compiler/rustc_mir_build/src/check_unsafety.rs b/compiler/rustc_mir_build/src/check_unsafety.rs index 122af3f621087..eadce3dc9c467 100644 --- a/compiler/rustc_mir_build/src/check_unsafety.rs +++ b/compiler/rustc_mir_build/src/check_unsafety.rs @@ -303,6 +303,9 @@ impl<'a, 'tcx> Visitor<'a, 'tcx> for UnsafetyVisitor<'a, 'tcx> { | ExprKind::Block { .. } | ExprKind::Borrow { .. } | ExprKind::Literal { .. } + | ExprKind::NamedConst { .. } + | ExprKind::NonHirLiteral { .. } + | ExprKind::ConstParam { .. } | ExprKind::ConstBlock { .. } | ExprKind::Deref { .. } | ExprKind::Index { .. } diff --git a/compiler/rustc_mir_build/src/thir/constant.rs b/compiler/rustc_mir_build/src/thir/constant.rs index 72c0985a63c33..30d7fdb7fec36 100644 --- a/compiler/rustc_mir_build/src/thir/constant.rs +++ b/compiler/rustc_mir_build/src/thir/constant.rs @@ -7,6 +7,7 @@ use rustc_middle::ty::{self, ParamEnv, TyCtxt}; use rustc_span::symbol::Symbol; use rustc_target::abi::Size; +// FIXME Once valtrees are available, get rid of this function and the query crate fn lit_to_const<'tcx>( tcx: TyCtxt<'tcx>, lit_input: LitToConstInput<'tcx>, @@ -57,7 +58,12 @@ crate fn lit_to_const<'tcx>( Ok(ty::Const::from_value(tcx, lit, ty)) } -fn parse_float<'tcx>(num: Symbol, fty: ty::FloatTy, neg: bool) -> Option> { +// FIXME move this to rustc_mir_build::build +pub(crate) fn parse_float<'tcx>( + num: Symbol, + fty: ty::FloatTy, + neg: bool, +) -> Option> { let num = num.as_str(); use rustc_apfloat::ieee::{Double, Single}; let scalar = match fty { diff --git a/compiler/rustc_mir_build/src/thir/cx/expr.rs b/compiler/rustc_mir_build/src/thir/cx/expr.rs index 23ee982489db2..cab5fcd179b47 100644 --- a/compiler/rustc_mir_build/src/thir/cx/expr.rs +++ b/compiler/rustc_mir_build/src/thir/cx/expr.rs @@ -14,7 +14,9 @@ use rustc_middle::ty::adjustment::{ Adjust, Adjustment, AutoBorrow, AutoBorrowMutability, PointerCast, }; use rustc_middle::ty::subst::{InternalSubsts, SubstsRef}; -use rustc_middle::ty::{self, AdtKind, Ty, UpvarSubsts, UserType}; +use rustc_middle::ty::{ + self, AdtKind, InlineConstSubsts, InlineConstSubstsParts, ScalarInt, Ty, UpvarSubsts, UserType, +}; use rustc_span::def_id::DefId; use rustc_span::Span; use rustc_target::abi::VariantIdx; @@ -290,11 +292,7 @@ impl<'tcx> Cx<'tcx> { } } - hir::ExprKind::Lit(ref lit) => ExprKind::Literal { - literal: self.const_eval_literal(&lit.node, expr_ty, lit.span, false), - user_ty: None, - const_id: None, - }, + hir::ExprKind::Lit(ref lit) => ExprKind::Literal { lit, neg: false }, hir::ExprKind::Binary(op, ref lhs, ref rhs) => { if self.typeck_results().is_method_call(expr) { @@ -359,11 +357,7 @@ impl<'tcx> Cx<'tcx> { let arg = self.mirror_expr(arg); self.overloaded_operator(expr, Box::new([arg])) } else if let hir::ExprKind::Lit(ref lit) = arg.kind { - ExprKind::Literal { - literal: self.const_eval_literal(&lit.node, expr_ty, lit.span, true), - user_ty: None, - const_id: None, - } + ExprKind::Literal { lit, neg: true } } else { ExprKind::Unary { op: UnOp::Neg, arg: self.mirror_expr(arg) } } @@ -524,11 +518,7 @@ impl<'tcx> Cx<'tcx> { ty, temp_lifetime, span: expr.span, - kind: ExprKind::Literal { - literal: ty::Const::zero_sized(self.tcx, ty), - user_ty, - const_id: None, - }, + kind: ExprKind::zero_sized_literal(user_ty), }), } } @@ -550,11 +540,7 @@ impl<'tcx> Cx<'tcx> { ty, temp_lifetime, span: expr.span, - kind: ExprKind::Literal { - literal: ty::Const::zero_sized(self.tcx, ty), - user_ty: None, - const_id: None, - }, + kind: ExprKind::zero_sized_literal(None), }), } } @@ -568,13 +554,21 @@ impl<'tcx> Cx<'tcx> { }, hir::ExprKind::ConstBlock(ref anon_const) => { - let anon_const_def_id = self.tcx.hir().local_def_id(anon_const.hir_id); - - // FIXME Do we want to use `from_inline_const` once valtrees - // are introduced? This would create `ValTree`s that will never be used... - let value = ty::Const::from_inline_const(self.tcx, anon_const_def_id); - - ExprKind::ConstBlock { value } + let tcx = self.tcx; + let local_def_id = tcx.hir().local_def_id(anon_const.hir_id); + let anon_const_def_id = local_def_id.to_def_id(); + + // Need to include the parent substs + let hir_id = tcx.hir().local_def_id_to_hir_id(local_def_id); + let ty = tcx.typeck(local_def_id).node_type(hir_id); + let typeck_root_def_id = tcx.typeck_root_def_id(anon_const_def_id); + let parent_substs = + tcx.erase_regions(InternalSubsts::identity_for_item(tcx, typeck_root_def_id)); + let substs = + InlineConstSubsts::new(tcx, InlineConstSubstsParts { parent_substs, ty }) + .substs; + + ExprKind::ConstBlock { did: anon_const_def_id, substs } } // Now comes the rote stuff: hir::ExprKind::Repeat(ref v, _) => { @@ -692,32 +686,36 @@ impl<'tcx> Cx<'tcx> { }; let source = if let Some((did, offset, var_ty)) = var { - let mk_const = |literal| Expr { + let param_env_ty = self.param_env.and(var_ty); + let size = self + .tcx + .layout_of(param_env_ty) + .unwrap_or_else(|e| { + panic!("could not compute layout for {:?}: {:?}", param_env_ty, e) + }) + .size; + let lit = ScalarInt::try_from_uint(offset as u128, size).unwrap(); + let kind = ExprKind::NonHirLiteral { lit, user_ty: None }; + let offset = self.thir.exprs.push(Expr { temp_lifetime, ty: var_ty, span: expr.span, - kind: ExprKind::Literal { literal, user_ty: None, const_id: None }, - }; - let offset = self.thir.exprs.push(mk_const(ty::Const::from_bits( - self.tcx, - offset as u128, - self.param_env.and(var_ty), - ))); + kind, + }); match did { Some(did) => { // in case we are offsetting from a computed discriminant // and not the beginning of discriminants (which is always `0`) let substs = InternalSubsts::identity_for_item(self.tcx(), did); - let lhs = ty::ConstS { - val: ty::ConstKind::Unevaluated(ty::Unevaluated::new( - ty::WithOptConstParam::unknown(did), - substs, - )), + let kind = + ExprKind::NamedConst { def_id: did, substs, user_ty: None }; + let lhs = self.thir.exprs.push(Expr { + temp_lifetime, ty: var_ty, - }; - let lhs = self.thir.exprs.push(mk_const(self.tcx().mk_const(lhs))); - let bin = - ExprKind::Binary { op: BinOp::Add, lhs: lhs, rhs: offset }; + span: expr.span, + kind, + }); + let bin = ExprKind::Binary { op: BinOp::Add, lhs, rhs: offset }; self.thir.exprs.push(Expr { temp_lifetime, ty: var_ty, @@ -832,16 +830,7 @@ impl<'tcx> Cx<'tcx> { } }; let ty = self.tcx().mk_fn_def(def_id, substs); - Expr { - temp_lifetime, - ty, - span, - kind: ExprKind::Literal { - literal: ty::Const::zero_sized(self.tcx(), ty), - user_ty, - const_id: None, - }, - } + Expr { temp_lifetime, ty, span, kind: ExprKind::zero_sized_literal(user_ty) } } fn convert_arm(&mut self, arm: &'tcx hir::Arm<'tcx>) -> ArmId { @@ -868,17 +857,9 @@ impl<'tcx> Cx<'tcx> { Res::Def(DefKind::Fn, _) | Res::Def(DefKind::AssocFn, _) | Res::Def(DefKind::Ctor(_, CtorKind::Fn), _) - | Res::SelfCtor(..) => { + | Res::SelfCtor(_) => { let user_ty = self.user_substs_applied_to_res(expr.hir_id, res); - debug!("convert_path_expr: user_ty={:?}", user_ty); - ExprKind::Literal { - literal: ty::Const::zero_sized( - self.tcx, - self.typeck_results().node_type(expr.hir_id), - ), - user_ty, - const_id: None, - } + ExprKind::zero_sized_literal(user_ty) } Res::Def(DefKind::ConstParam, def_id) => { @@ -888,31 +869,14 @@ impl<'tcx> Cx<'tcx> { let generics = self.tcx.generics_of(item_def_id); let index = generics.param_def_id_to_index[&def_id]; let name = self.tcx.hir().name(hir_id); - let val = ty::ConstKind::Param(ty::ParamConst::new(index, name)); - ExprKind::Literal { - literal: self.tcx.mk_const(ty::ConstS { - val, - ty: self.typeck_results().node_type(expr.hir_id), - }), - user_ty: None, - const_id: Some(def_id), - } + let param = ty::ParamConst::new(index, name); + + ExprKind::ConstParam { param, def_id } } Res::Def(DefKind::Const, def_id) | Res::Def(DefKind::AssocConst, def_id) => { let user_ty = self.user_substs_applied_to_res(expr.hir_id, res); - debug!("convert_path_expr: (const) user_ty={:?}", user_ty); - ExprKind::Literal { - literal: self.tcx.mk_const(ty::ConstS { - val: ty::ConstKind::Unevaluated(ty::Unevaluated::new( - ty::WithOptConstParam::unknown(def_id), - substs, - )), - ty: self.typeck_results().node_type(expr.hir_id), - }), - user_ty, - const_id: Some(def_id), - } + ExprKind::NamedConst { def_id, substs, user_ty: user_ty } } Res::Def(DefKind::Ctor(_, CtorKind::Const), def_id) => { diff --git a/compiler/rustc_mir_build/src/thir/cx/mod.rs b/compiler/rustc_mir_build/src/thir/cx/mod.rs index 426596bf13c0a..f17fe38b292cb 100644 --- a/compiler/rustc_mir_build/src/thir/cx/mod.rs +++ b/compiler/rustc_mir_build/src/thir/cx/mod.rs @@ -5,7 +5,6 @@ use crate::thir::pattern::pat_from_hir; use crate::thir::util::UserAnnotatedTyHelpers; -use rustc_ast as ast; use rustc_data_structures::steal::Steal; use rustc_errors::ErrorGuaranteed; use rustc_hir as hir; @@ -13,9 +12,8 @@ use rustc_hir::def_id::{DefId, LocalDefId}; use rustc_hir::HirId; use rustc_hir::Node; use rustc_middle::middle::region; -use rustc_middle::mir::interpret::{LitToConstError, LitToConstInput}; use rustc_middle::thir::*; -use rustc_middle::ty::{self, Ty, TyCtxt}; +use rustc_middle::ty::{self, TyCtxt}; use rustc_span::Span; crate fn thir_body<'tcx>( @@ -77,25 +75,6 @@ impl<'tcx> Cx<'tcx> { } } - crate fn const_eval_literal( - &mut self, - lit: &'tcx ast::LitKind, - ty: Ty<'tcx>, - sp: Span, - neg: bool, - ) -> ty::Const<'tcx> { - trace!("const_eval_literal: {:#?}, {:?}, {:?}, {:?}", lit, ty, sp, neg); - - match self.tcx.at(sp).lit_to_const(LitToConstInput { lit, ty, neg }) { - Ok(c) => c, - Err(LitToConstError::Reported) => { - // create a dummy value and continue compiling - self.tcx.const_error(ty) - } - Err(LitToConstError::TypeError) => bug!("const_eval_literal: had type error"), - } - } - crate fn pattern_from_hir(&mut self, p: &hir::Pat<'_>) -> Pat<'tcx> { let p = match self.tcx.hir().get(p.hir_id) { Node::Pat(p) | Node::Binding(p) => p, diff --git a/compiler/rustc_trait_selection/src/traits/const_evaluatable.rs b/compiler/rustc_trait_selection/src/traits/const_evaluatable.rs index 40a39c4cfc2e3..490c04e7be241 100644 --- a/compiler/rustc_trait_selection/src/traits/const_evaluatable.rs +++ b/compiler/rustc_trait_selection/src/traits/const_evaluatable.rs @@ -14,7 +14,9 @@ use rustc_hir::def::DefKind; use rustc_index::vec::IndexVec; use rustc_infer::infer::InferCtxt; use rustc_middle::mir; -use rustc_middle::mir::interpret::ErrorHandled; +use rustc_middle::mir::interpret::{ + ConstValue, ErrorHandled, LitToConstError, LitToConstInput, Scalar, +}; use rustc_middle::thir; use rustc_middle::thir::abstract_const::{self, Node, NodeId, NotConstEvaluatable}; use rustc_middle::ty::subst::{Subst, SubstsRef}; @@ -28,13 +30,13 @@ use std::iter; use std::ops::ControlFlow; /// Check if a given constant can be evaluated. +#[instrument(skip(infcx), level = "debug")] pub fn is_const_evaluatable<'cx, 'tcx>( infcx: &InferCtxt<'cx, 'tcx>, uv: ty::Unevaluated<'tcx, ()>, param_env: ty::ParamEnv<'tcx>, span: Span, ) -> Result<(), NotConstEvaluatable> { - debug!("is_const_evaluatable({:?})", uv); let tcx = infcx.tcx; if tcx.features().generic_const_exprs { @@ -304,6 +306,7 @@ impl<'a, 'tcx> AbstractConstBuilder<'a, 'tcx> { Err(reported) } + #[instrument(skip(tcx, body, body_id), level = "debug")] fn new( tcx: TyCtxt<'tcx>, (body, body_id): (&'a thir::Thir<'tcx>, thir::ExprId), @@ -315,29 +318,61 @@ impl<'a, 'tcx> AbstractConstBuilder<'a, 'tcx> { thir: &'a thir::Thir<'tcx>, } + use crate::rustc_middle::thir::visit::Visitor; use thir::visit; - impl<'a, 'tcx: 'a> visit::Visitor<'a, 'tcx> for IsThirPolymorphic<'a, 'tcx> { + + impl<'a, 'tcx> IsThirPolymorphic<'a, 'tcx> { + fn expr_is_poly(&mut self, expr: &thir::Expr<'tcx>) -> bool { + if expr.ty.has_param_types_or_consts() { + return true; + } + + match expr.kind { + thir::ExprKind::NamedConst { substs, .. } => substs.has_param_types_or_consts(), + thir::ExprKind::ConstParam { .. } => true, + thir::ExprKind::Repeat { value, count } => { + self.visit_expr(&self.thir()[value]); + count.has_param_types_or_consts() + } + _ => false, + } + } + + fn pat_is_poly(&mut self, pat: &thir::Pat<'tcx>) -> bool { + if pat.ty.has_param_types_or_consts() { + return true; + } + + match pat.kind.as_ref() { + thir::PatKind::Constant { value } => value.has_param_types_or_consts(), + thir::PatKind::Range(thir::PatRange { lo, hi, .. }) => { + lo.has_param_types_or_consts() || hi.has_param_types_or_consts() + } + _ => false, + } + } + } + + impl<'a, 'tcx> visit::Visitor<'a, 'tcx> for IsThirPolymorphic<'a, 'tcx> { fn thir(&self) -> &'a thir::Thir<'tcx> { &self.thir } + #[instrument(skip(self), level = "debug")] fn visit_expr(&mut self, expr: &thir::Expr<'tcx>) { - self.is_poly |= expr.ty.has_param_types_or_consts(); + self.is_poly |= self.expr_is_poly(expr); if !self.is_poly { visit::walk_expr(self, expr) } } + #[instrument(skip(self), level = "debug")] fn visit_pat(&mut self, pat: &thir::Pat<'tcx>) { - self.is_poly |= pat.ty.has_param_types_or_consts(); + self.is_poly |= self.pat_is_poly(pat); if !self.is_poly { visit::walk_pat(self, pat); } } - - fn visit_const(&mut self, ct: ty::Const<'tcx>) { - self.is_poly |= ct.has_param_types_or_consts(); - } } let mut is_poly_vis = IsThirPolymorphic { is_poly: false, thir: body }; @@ -393,16 +428,49 @@ impl<'a, 'tcx> AbstractConstBuilder<'a, 'tcx> { fn recurse_build(&mut self, node: thir::ExprId) -> Result { use thir::ExprKind; let node = &self.body.exprs[node]; - debug!("recurse_build: node={:?}", node); Ok(match &node.kind { // I dont know if handling of these 3 is correct &ExprKind::Scope { value, .. } => self.recurse_build(value)?, &ExprKind::PlaceTypeAscription { source, .. } | &ExprKind::ValueTypeAscription { source, .. } => self.recurse_build(source)?, + &ExprKind::Literal { lit, neg} => { + let sp = node.span; + let constant = + match self.tcx.at(sp).lit_to_const(LitToConstInput { lit: &lit.node, ty: node.ty, neg }) { + Ok(c) => c, + Err(LitToConstError::Reported) => { + self.tcx.const_error(node.ty) + } + Err(LitToConstError::TypeError) => { + bug!("encountered type error in lit_to_const") + } + }; + + self.nodes.push(Node::Leaf(constant)) + } + &ExprKind::NonHirLiteral { lit , user_ty: _} => { + // FIXME Construct a Valtree from this ScalarInt when introducing Valtrees + let const_value = ConstValue::Scalar(Scalar::Int(lit)); + self.nodes.push(Node::Leaf(ty::Const::from_value(self.tcx, const_value, node.ty))) + } + &ExprKind::NamedConst { def_id, substs, user_ty: _ } => { + let uneval = ty::Unevaluated::new(ty::WithOptConstParam::unknown(def_id), substs); + + let constant = self.tcx.mk_const(ty::ConstS { + val: ty::ConstKind::Unevaluated(uneval), + ty: node.ty, + }); - // subtle: associated consts are literals this arm handles - // `::ASSOC` as well as `12` - &ExprKind::Literal { literal, .. } => self.nodes.push(Node::Leaf(literal)), + self.nodes.push(Node::Leaf(constant)) + } + + ExprKind::ConstParam {param, ..} => { + let const_param = self.tcx.mk_const(ty::ConstS { + val: ty::ConstKind::Param(*param), + ty: node.ty, + }); + self.nodes.push(Node::Leaf(const_param)) + } ExprKind::Call { fun, args, .. } => { let fun = self.recurse_build(*fun)?; @@ -585,6 +653,7 @@ pub(super) fn try_unify_abstract_consts<'tcx>( // on `ErrorGuaranteed`. } +#[instrument(skip(tcx, f), level = "debug")] pub fn walk_abstract_const<'tcx, R, F>( tcx: TyCtxt<'tcx>, ct: AbstractConst<'tcx>, @@ -593,6 +662,7 @@ pub fn walk_abstract_const<'tcx, R, F>( where F: FnMut(AbstractConst<'tcx>) -> ControlFlow, { + #[instrument(skip(tcx, f), level = "debug")] fn recurse<'tcx, R>( tcx: TyCtxt<'tcx>, ct: AbstractConst<'tcx>, @@ -600,6 +670,7 @@ where ) -> ControlFlow { f(ct)?; let root = ct.root(tcx); + debug!(?root); match root { Node::Leaf(_) => ControlFlow::CONTINUE, Node::Binop(_, l, r) => { diff --git a/src/test/ui/mir/thir-constparam-temp.rs b/src/test/ui/mir/thir-constparam-temp.rs new file mode 100644 index 0000000000000..cdc5910b36cfa --- /dev/null +++ b/src/test/ui/mir/thir-constparam-temp.rs @@ -0,0 +1,20 @@ +// build-pass + +#![feature(adt_const_params)] +#![allow(incomplete_features)] + +#[derive(PartialEq, Eq)] +struct Yikes; + +impl Yikes { + fn mut_self(&mut self) {} +} + +fn foo() { + YIKES.mut_self() + //~^ WARNING taking a mutable reference +} + +fn main() { + foo::<{ Yikes }>() +} diff --git a/src/test/ui/mir/thir-constparam-temp.stderr b/src/test/ui/mir/thir-constparam-temp.stderr new file mode 100644 index 0000000000000..297102e657ef6 --- /dev/null +++ b/src/test/ui/mir/thir-constparam-temp.stderr @@ -0,0 +1,22 @@ +warning: taking a mutable reference to a `const` item + --> $DIR/thir-constparam-temp.rs:14:5 + | +LL | YIKES.mut_self() + | ^^^^^^^^^^^^^^^^ + | + = note: `#[warn(const_item_mutation)]` on by default + = note: each usage of a `const` item creates a new temporary + = note: the mutable reference will refer to this temporary, not the original `const` item +note: mutable reference created due to call to this method + --> $DIR/thir-constparam-temp.rs:10:5 + | +LL | fn mut_self(&mut self) {} + | ^^^^^^^^^^^^^^^^^^^^^^ +note: `const` item defined here + --> $DIR/thir-constparam-temp.rs:13:14 + | +LL | fn foo() { + | ^^^^^ + +warning: 1 warning emitted +