diff --git a/src/librustc_typeck/check/op.rs b/src/librustc_typeck/check/op.rs index 9e8e00594e60a..23081b87d2651 100644 --- a/src/librustc_typeck/check/op.rs +++ b/src/librustc_typeck/check/op.rs @@ -12,8 +12,8 @@ use super::{FnCtxt, Needs}; use super::method::MethodCallee; -use rustc::ty::{self, Ty, TypeFoldable, TypeVariants}; -use rustc::ty::TypeVariants::{TyStr, TyRef, TyAdt}; +use rustc::ty::{self, Ty, TypeFoldable}; +use rustc::ty::TypeVariants::{TyRef, TyAdt, TyStr, TyUint, TyNever, TyTuple, TyChar, TyArray}; use rustc::ty::adjustment::{Adjustment, Adjust, AllowTwoPhase, AutoBorrow, AutoBorrowMutability}; use rustc::infer::type_variable::TypeVariableOrigin; use errors; @@ -246,76 +246,151 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> { Err(()) => { // error types are considered "builtin" if !lhs_ty.references_error() { - if let IsAssign::Yes = is_assign { - struct_span_err!(self.tcx.sess, expr.span, E0368, - "binary assignment operation `{}=` \ - cannot be applied to type `{}`", - op.node.as_str(), - lhs_ty) - .span_label(lhs_expr.span, - format!("cannot use `{}=` on type `{}`", - op.node.as_str(), lhs_ty)) - .emit(); - } else { - let mut err = struct_span_err!(self.tcx.sess, expr.span, E0369, - "binary operation `{}` cannot be applied to type `{}`", - op.node.as_str(), - lhs_ty); - - if let TypeVariants::TyRef(_, rty, _) = lhs_ty.sty { - if { - !self.infcx.type_moves_by_default(self.param_env, - rty, - lhs_expr.span) && - self.lookup_op_method(rty, - &[rhs_ty], - Op::Binary(op, is_assign)) - .is_ok() - } { - err.note( - &format!( - "this is a reference to a type that `{}` can be applied \ - to; you need to dereference this variable once for this \ - operation to work", - op.node.as_str())); + let codemap = self.tcx.sess.codemap(); + match is_assign { + IsAssign::Yes => { + let mut err = struct_span_err!(self.tcx.sess, expr.span, E0368, + "binary assignment operation `{}=` \ + cannot be applied to type `{}`", + op.node.as_str(), + lhs_ty); + err.span_label(lhs_expr.span, + format!("cannot use `{}=` on type `{}`", + op.node.as_str(), lhs_ty)); + let mut suggested_deref = false; + if let TyRef(_, mut rty, _) = lhs_ty.sty { + if { + !self.infcx.type_moves_by_default(self.param_env, + rty, + lhs_expr.span) && + self.lookup_op_method(rty, + &[rhs_ty], + Op::Binary(op, is_assign)) + .is_ok() + } { + if let Ok(lstring) = codemap.span_to_snippet(lhs_expr.span) { + while let TyRef(_, rty_inner, _) = rty.sty { + rty = rty_inner; + } + let msg = &format!( + "`{}=` can be used on '{}', you can \ + dereference `{2}`: `*{2}`", + op.node.as_str(), + rty, + lstring + ); + err.help(msg); + suggested_deref = true; + } + } } + let missing_trait = match op.node { + hir::BiAdd => Some("std::ops::AddAssign"), + hir::BiSub => Some("std::ops::SubAssign"), + hir::BiMul => Some("std::ops::MulAssign"), + hir::BiDiv => Some("std::ops::DivAssign"), + hir::BiRem => Some("std::ops::RemAssign"), + hir::BiBitAnd => Some("std::ops::BitAndAssign"), + hir::BiBitXor => Some("std::ops::BitXorAssign"), + hir::BiBitOr => Some("std::ops::BitOrAssign"), + hir::BiShl => Some("std::ops::ShlAssign"), + hir::BiShr => Some("std::ops::ShrAssign"), + _ => None + }; + if let Some(missing_trait) = missing_trait { + if op.node == hir::BiAdd && + self.check_str_addition(expr, lhs_expr, rhs_expr, lhs_ty, + rhs_ty, &mut err) { + // This has nothing here because it means we did string + // concatenation (e.g. "Hello " + "World!"). This means + // we don't want the note in the else clause to be emitted + } else if let ty::TyParam(_) = lhs_ty.sty { + // FIXME: point to span of param + err.note(&format!( + "`{}` might need a bound for `{}`", + lhs_ty, missing_trait + )); + } else if !suggested_deref { + err.note(&format!( + "an implementation of `{}` might \ + be missing for `{}`", + missing_trait, lhs_ty + )); + } + } + err.emit(); } - - let missing_trait = match op.node { - hir::BiAdd => Some("std::ops::Add"), - hir::BiSub => Some("std::ops::Sub"), - hir::BiMul => Some("std::ops::Mul"), - hir::BiDiv => Some("std::ops::Div"), - hir::BiRem => Some("std::ops::Rem"), - hir::BiBitAnd => Some("std::ops::BitAnd"), - hir::BiBitOr => Some("std::ops::BitOr"), - hir::BiShl => Some("std::ops::Shl"), - hir::BiShr => Some("std::ops::Shr"), - hir::BiEq | hir::BiNe => Some("std::cmp::PartialEq"), - hir::BiLt | hir::BiLe | hir::BiGt | hir::BiGe => - Some("std::cmp::PartialOrd"), - _ => None - }; - - if let Some(missing_trait) = missing_trait { - if missing_trait == "std::ops::Add" && - self.check_str_addition(expr, lhs_expr, rhs_expr, lhs_ty, - rhs_ty, &mut err) { - // This has nothing here because it means we did string - // concatenation (e.g. "Hello " + "World!"). This means - // we don't want the note in the else clause to be emitted - } else if let ty::TyParam(_) = lhs_ty.sty { - // FIXME: point to span of param - err.note( - &format!("`{}` might need a bound for `{}`", - lhs_ty, missing_trait)); - } else { - err.note( - &format!("an implementation of `{}` might be missing for `{}`", - missing_trait, lhs_ty)); + IsAssign::No => { + let mut err = struct_span_err!(self.tcx.sess, expr.span, E0369, + "binary operation `{}` cannot be applied to type `{}`", + op.node.as_str(), + lhs_ty); + let mut suggested_deref = false; + if let TyRef(_, mut rty, _) = lhs_ty.sty { + if { + !self.infcx.type_moves_by_default(self.param_env, + rty, + lhs_expr.span) && + self.lookup_op_method(rty, + &[rhs_ty], + Op::Binary(op, is_assign)) + .is_ok() + } { + if let Ok(lstring) = codemap.span_to_snippet(lhs_expr.span) { + while let TyRef(_, rty_inner, _) = rty.sty { + rty = rty_inner; + } + let msg = &format!( + "`{}` can be used on '{}', you can \ + dereference `{2}`: `*{2}`", + op.node.as_str(), + rty, + lstring + ); + err.help(msg); + suggested_deref = true; + } + } } + let missing_trait = match op.node { + hir::BiAdd => Some("std::ops::Add"), + hir::BiSub => Some("std::ops::Sub"), + hir::BiMul => Some("std::ops::Mul"), + hir::BiDiv => Some("std::ops::Div"), + hir::BiRem => Some("std::ops::Rem"), + hir::BiBitAnd => Some("std::ops::BitAnd"), + hir::BiBitXor => Some("std::ops::BitXor"), + hir::BiBitOr => Some("std::ops::BitOr"), + hir::BiShl => Some("std::ops::Shl"), + hir::BiShr => Some("std::ops::Shr"), + hir::BiEq | hir::BiNe => Some("std::cmp::PartialEq"), + hir::BiLt | hir::BiLe | hir::BiGt | hir::BiGe => + Some("std::cmp::PartialOrd"), + _ => None + }; + if let Some(missing_trait) = missing_trait { + if op.node == hir::BiAdd && + self.check_str_addition(expr, lhs_expr, rhs_expr, lhs_ty, + rhs_ty, &mut err) { + // This has nothing here because it means we did string + // concatenation (e.g. "Hello " + "World!"). This means + // we don't want the note in the else clause to be emitted + } else if let ty::TyParam(_) = lhs_ty.sty { + // FIXME: point to span of param + err.note(&format!( + "`{}` might need a bound for `{}`", + lhs_ty, missing_trait + )); + } else if !suggested_deref { + err.note(&format!( + "an implementation of `{}` might \ + be missing for `{}`", + missing_trait, lhs_ty + )); + } + } + err.emit(); } - err.emit(); } } self.tcx.types.err @@ -393,9 +468,29 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> { Err(()) => { let actual = self.resolve_type_vars_if_possible(&operand_ty); if !actual.references_error() { - struct_span_err!(self.tcx.sess, ex.span, E0600, + let mut err = struct_span_err!(self.tcx.sess, ex.span, E0600, "cannot apply unary operator `{}` to type `{}`", - op.as_str(), actual).emit(); + op.as_str(), actual); + err.span_label(ex.span, format!("cannot apply unary \ + operator `{}`", op.as_str())); + match actual.sty { + TyUint(_) if op == hir::UnNeg => { + err.note(&format!("unsigned values cannot be negated")); + }, + TyStr | TyNever | TyChar | TyTuple(_) | TyArray(_,_) => {}, + TyRef(_, ref lty, _) if lty.sty == TyStr => {}, + _ => { + let missing_trait = match op { + hir::UnNeg => "std::ops::Neg", + hir::UnNot => "std::ops::Not", + hir::UnDeref => "std::ops::UnDerf" + }; + err.note(&format!("an implementation of `{}` might \ + be missing for `{}`", + missing_trait, operand_ty)); + } + } + err.emit(); } self.tcx.types.err } diff --git a/src/test/ui/binary-op-on-double-ref.stderr b/src/test/ui/binary-op-on-double-ref.stderr index 07aa3bfe40dea..c89defa3dd196 100644 --- a/src/test/ui/binary-op-on-double-ref.stderr +++ b/src/test/ui/binary-op-on-double-ref.stderr @@ -4,8 +4,7 @@ error[E0369]: binary operation `%` cannot be applied to type `&&{integer}` LL | x % 2 == 0 | ^^^^^ | - = note: this is a reference to a type that `%` can be applied to; you need to dereference this variable once for this operation to work - = note: an implementation of `std::ops::Rem` might be missing for `&&{integer}` + = help: `%` can be used on '{integer}', you can dereference `x`: `*x` error: aborting due to previous error diff --git a/src/test/ui/codemap_tests/issue-28308.stderr b/src/test/ui/codemap_tests/issue-28308.stderr index 2c8a33d95c03a..15c159a3b153c 100644 --- a/src/test/ui/codemap_tests/issue-28308.stderr +++ b/src/test/ui/codemap_tests/issue-28308.stderr @@ -2,7 +2,7 @@ error[E0600]: cannot apply unary operator `!` to type `&'static str` --> $DIR/issue-28308.rs:12:5 | LL | assert!("foo"); - | ^^^^^^^^^^^^^^^ + | ^^^^^^^^^^^^^^^ cannot apply unary operator `!` error: aborting due to previous error diff --git a/src/test/ui/error-codes/E0067.stderr b/src/test/ui/error-codes/E0067.stderr index 76f06c7c46379..43e1ca4096cf6 100644 --- a/src/test/ui/error-codes/E0067.stderr +++ b/src/test/ui/error-codes/E0067.stderr @@ -5,6 +5,8 @@ LL | LinkedList::new() += 1; //~ ERROR E0368 | -----------------^^^^^ | | | cannot use `+=` on type `std::collections::LinkedList<_>` + | + = note: an implementation of `std::ops::AddAssign` might be missing for `std::collections::LinkedList<_>` error[E0067]: invalid left-hand side expression --> $DIR/E0067.rs:14:5 diff --git a/src/test/ui/error-codes/E0600.stderr b/src/test/ui/error-codes/E0600.stderr index 500feb39f5e74..c29ec4fe6ae76 100644 --- a/src/test/ui/error-codes/E0600.stderr +++ b/src/test/ui/error-codes/E0600.stderr @@ -2,7 +2,7 @@ error[E0600]: cannot apply unary operator `!` to type `&'static str` --> $DIR/E0600.rs:12:5 | LL | !"a"; //~ ERROR E0600 - | ^^^^ + | ^^^^ cannot apply unary operator `!` error: aborting due to previous error diff --git a/src/test/ui/error-festival.stderr b/src/test/ui/error-festival.stderr index 345691352b407..69f11b4b7c08c 100644 --- a/src/test/ui/error-festival.stderr +++ b/src/test/ui/error-festival.stderr @@ -17,6 +17,8 @@ LL | x += 2; | -^^^^^ | | | cannot use `+=` on type `&str` + | + = note: an implementation of `std::ops::AddAssign` might be missing for `&str` error[E0599]: no method named `z` found for type `&str` in the current scope --> $DIR/error-festival.rs:26:7 @@ -28,7 +30,9 @@ error[E0600]: cannot apply unary operator `!` to type `Question` --> $DIR/error-festival.rs:29:5 | LL | !Question::Yes; - | ^^^^^^^^^^^^^^ + | ^^^^^^^^^^^^^^ cannot apply unary operator `!` + | + = note: an implementation of `std::ops::Not` might be missing for `Question` error[E0604]: only `u8` can be cast as `char`, not `u32` --> $DIR/error-festival.rs:35:5 diff --git a/src/test/ui/feature-gate-negate-unsigned.stderr b/src/test/ui/feature-gate-negate-unsigned.stderr index 1025b56f55bc3..85e9b56e4af9d 100644 --- a/src/test/ui/feature-gate-negate-unsigned.stderr +++ b/src/test/ui/feature-gate-negate-unsigned.stderr @@ -2,13 +2,17 @@ error[E0600]: cannot apply unary operator `-` to type `usize` --> $DIR/feature-gate-negate-unsigned.rs:20:23 | LL | let _max: usize = -1; - | ^^ + | ^^ cannot apply unary operator `-` + | + = note: unsigned values cannot be negated error[E0600]: cannot apply unary operator `-` to type `u8` --> $DIR/feature-gate-negate-unsigned.rs:24:14 | LL | let _y = -x; - | ^^ + | ^^ cannot apply unary operator `-` + | + = note: unsigned values cannot be negated error: aborting due to 2 previous errors diff --git a/src/test/ui/issue-5239-1.stderr b/src/test/ui/issue-5239-1.stderr index 2f9204e72d3fb..7ae01fb7d6012 100644 --- a/src/test/ui/issue-5239-1.stderr +++ b/src/test/ui/issue-5239-1.stderr @@ -5,6 +5,8 @@ LL | let x = |ref x: isize| { x += 1; }; | -^^^^^ | | | cannot use `+=` on type `&isize` + | + = help: `+=` can be used on 'isize', you can dereference `x`: `*x` error: aborting due to previous error diff --git a/src/test/ui/reachable/expr_unary.stderr b/src/test/ui/reachable/expr_unary.stderr index 165eccd42396b..b889c884fcbb2 100644 --- a/src/test/ui/reachable/expr_unary.stderr +++ b/src/test/ui/reachable/expr_unary.stderr @@ -2,7 +2,7 @@ error[E0600]: cannot apply unary operator `!` to type `!` --> $DIR/expr_unary.rs:17:16 | LL | let x: ! = ! { return; }; //~ ERROR unreachable - | ^^^^^^^^^^^^^ + | ^^^^^^^^^^^^^ cannot apply unary operator `!` error: unreachable expression --> $DIR/expr_unary.rs:17:16 diff --git a/src/test/ui/type-check/missing_trait_impl.rs b/src/test/ui/type-check/missing_trait_impl.rs index adf6b85b6429c..b3e79ce2447fb 100644 --- a/src/test/ui/type-check/missing_trait_impl.rs +++ b/src/test/ui/type-check/missing_trait_impl.rs @@ -14,3 +14,7 @@ fn main() { fn foo(x: T, y: T) { let z = x + y; //~ ERROR binary operation `+` cannot be applied to type `T` } + +fn bar(x: T) { + x += x; //~ ERROR binary assignment operation `+=` cannot be applied to type `T` +} diff --git a/src/test/ui/type-check/missing_trait_impl.stderr b/src/test/ui/type-check/missing_trait_impl.stderr index 777f16b12ce68..4b01a626814e5 100644 --- a/src/test/ui/type-check/missing_trait_impl.stderr +++ b/src/test/ui/type-check/missing_trait_impl.stderr @@ -6,6 +6,17 @@ LL | let z = x + y; //~ ERROR binary operation `+` cannot be applied to type | = note: `T` might need a bound for `std::ops::Add` -error: aborting due to previous error +error[E0368]: binary assignment operation `+=` cannot be applied to type `T` + --> $DIR/missing_trait_impl.rs:19:5 + | +LL | x += x; //~ ERROR binary assignment operation `+=` cannot be applied to type `T` + | -^^^^^ + | | + | cannot use `+=` on type `T` + | + = note: `T` might need a bound for `std::ops::AddAssign` + +error: aborting due to 2 previous errors -For more information about this error, try `rustc --explain E0369`. +Some errors occurred: E0368, E0369. +For more information about an error, try `rustc --explain E0368`.