diff --git a/src/librustc_typeck/check/op.rs b/src/librustc_typeck/check/op.rs index de042ae31fbd..69b891af6632 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; @@ -246,39 +246,76 @@ 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())); + 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 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 + }; + let mut suggested_deref = false; + if let TyRef(_, ref ty_mut) = lhs_ty.sty { + if { + !self.infcx.type_moves_by_default(self.param_env, + ty_mut.ty, + lhs_expr.span) && + self.lookup_op_method(ty_mut.ty, + &[rhs_ty], + Op::Binary(op, is_assign)) + .is_ok() + } { + let codemap = self.tcx.sess.codemap(); + match codemap.span_to_snippet(lhs_expr.span) { + Ok(lstring) =>{ + let msg = &format!( + "`{}=` can be used on '{}', you can \ + dereference `{2}`: `*{2}`", + op.node.as_str(), ty_mut.ty, lstring); + err.help(msg); + suggested_deref = true; + }, + _ => {} + }; + } } + if let Some(missing_trait) = missing_trait { + if missing_trait == "std::ops::AddAssign" && + 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(); } IsAssign::No => { let mut err = struct_span_err!(self.tcx.sess, expr.span, E0369, @@ -301,7 +338,8 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> { Some("std::cmp::PartialOrd"), _ => None }; - if let TypeVariants::TyRef(_, ref ty_mut) = lhs_ty.sty { + let mut suggested_deref = false; + if let TyRef(_, ref ty_mut) = lhs_ty.sty { if { !self.infcx.type_moves_by_default(self.param_env, ty_mut.ty, @@ -311,36 +349,44 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> { 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 codemap.span_to_snippet(lhs_expr.span) { + Ok(lstring) =>{ + let msg = &format!( + "`{}` can be used on '{}', you can \ + dereference `{2}`: `*{2}`", + op.node.as_str(), ty_mut.ty, lstring); + err.help(msg); + suggested_deref = true; + }, + _ =>{} + } } } - (err, missing_trait) - } - }; - 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)); + 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 { + 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 } @@ -420,13 +466,27 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> { let mut err = struct_span_err!(self.tcx.sess, ex.span, E0600, "cannot apply unary operator `{}` to type `{}`", op.as_str(), actual); + err.span_label(ex.span, format!("cannot apply unary \ + operator `{}`", op.as_str())); 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 `{}`", + 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.ty.sty == TyStr => {}, + _ => { + 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 07aa3bfe40de..020d74bee521 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 b5c2376239d1..15c159a3b153 100644 --- a/src/test/ui/codemap_tests/issue-28308.stderr +++ b/src/test/ui/codemap_tests/issue-28308.stderr @@ -2,9 +2,7 @@ error[E0600]: cannot apply unary operator `!` to type `&'static str` --> $DIR/issue-28308.rs:12:5 | LL | assert!("foo"); - | ^^^^^^^^^^^^^^^ - | - = note: an implementation of `std::ops::Not` might be missing for `&'static str` + | ^^^^^^^^^^^^^^^ cannot apply unary operator `!` error: aborting due to previous error diff --git a/src/test/ui/error-codes/E0600.stderr b/src/test/ui/error-codes/E0600.stderr index bd79ea79c8b5..c29ec4fe6ae7 100644 --- a/src/test/ui/error-codes/E0600.stderr +++ b/src/test/ui/error-codes/E0600.stderr @@ -2,9 +2,7 @@ error[E0600]: cannot apply unary operator `!` to type `&'static str` --> $DIR/E0600.rs:12:5 | LL | !"a"; //~ ERROR E0600 - | ^^^^ - | - = note: an implementation of `std::ops::Not` might be missing for `&'static str` + | ^^^^ 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 6165806aac9c..69f11b4b7c08 100644 --- a/src/test/ui/error-festival.stderr +++ b/src/test/ui/error-festival.stderr @@ -30,7 +30,7 @@ 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` diff --git a/src/test/ui/feature-gate-negate-unsigned.stderr b/src/test/ui/feature-gate-negate-unsigned.stderr index 8831e874a200..85e9b56e4af9 100644 --- a/src/test/ui/feature-gate-negate-unsigned.stderr +++ b/src/test/ui/feature-gate-negate-unsigned.stderr @@ -2,17 +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: an implementation of `std::ops::Neg` might be missing for `usize` + = 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: an implementation of `std::ops::Neg` might be missing for `u8` + = 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 adef9848ba74..7ae01fb7d601 100644 --- a/src/test/ui/issue-5239-1.stderr +++ b/src/test/ui/issue-5239-1.stderr @@ -6,7 +6,7 @@ LL | let x = |ref x: isize| { x += 1; }; | | | cannot use `+=` on type `&isize` | - = note: an implementation of `std::ops::AddAssign` might be missing for `&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 7ba21efcd512..b889c884fcbb 100644 --- a/src/test/ui/reachable/expr_unary.stderr +++ b/src/test/ui/reachable/expr_unary.stderr @@ -2,9 +2,7 @@ error[E0600]: cannot apply unary operator `!` to type `!` --> $DIR/expr_unary.rs:17:16 | LL | let x: ! = ! { return; }; //~ ERROR unreachable - | ^^^^^^^^^^^^^ - | - = note: an implementation of `std::ops::Not` might be missing for `!` + | ^^^^^^^^^^^^^ cannot apply unary operator `!` error: unreachable expression --> $DIR/expr_unary.rs:17:16