diff --git a/compiler/rustc_typeck/src/check/op.rs b/compiler/rustc_typeck/src/check/op.rs index 8ebfcdd539b..838f8b0a61d 100644 --- a/compiler/rustc_typeck/src/check/op.rs +++ b/compiler/rustc_typeck/src/check/op.rs @@ -549,7 +549,6 @@ fn check_str_addition( is_assign: IsAssign, op: hir::BinOp, ) -> bool { - let source_map = self.tcx.sess.source_map(); let remove_borrow_msg = "String concatenation appends the string on the right to the \ string on the left and may require reallocation. This \ requires ownership of the string on the left"; @@ -574,31 +573,22 @@ fn check_str_addition( ) => { if let IsAssign::No = is_assign { // Do not supply this message if `&str += &str` - err.span_label( - op.span, - "`+` cannot be used to concatenate two `&str` strings", - ); - match source_map.span_to_snippet(lhs_expr.span) { - Ok(lstring) => { - err.span_suggestion( - lhs_expr.span, - if lstring.starts_with('&') { - remove_borrow_msg - } else { - msg - }, - if let Some(stripped) = lstring.strip_prefix('&') { - // let a = String::new(); - // let _ = &a + "bar"; - stripped.to_string() - } else { - format!("{}.to_owned()", lstring) - }, - Applicability::MachineApplicable, - ) - } - _ => err.help(msg), - }; + err.span_label(op.span, "`+` cannot be used to concatenate two `&str` strings"); + if let hir::ExprKind::AddrOf(_,_,lhs_inner_expr) = lhs_expr.kind { + err.span_suggestion( + lhs_expr.span.until(lhs_inner_expr.span), + remove_borrow_msg, + "".to_owned(), + Applicability::MachineApplicable + ); + } else { + err.span_suggestion( + lhs_expr.span.shrink_to_hi(), + msg, + ".to_owned()".to_owned(), + Applicability::MachineApplicable + ); + } } true } @@ -609,32 +599,22 @@ fn check_str_addition( op.span, "`+` cannot be used to concatenate a `&str` with a `String`", ); - match ( - source_map.span_to_snippet(lhs_expr.span), - source_map.span_to_snippet(rhs_expr.span), - is_assign, - ) { - (Ok(l), Ok(r), IsAssign::No) => { - let to_string = if let Some(stripped) = l.strip_prefix('&') { - // let a = String::new(); let b = String::new(); - // let _ = &a + b; - stripped.to_string() - } else { - format!("{}.to_owned()", l) - }; - err.multipart_suggestion( - msg, - vec![ - (lhs_expr.span, to_string), - (rhs_expr.span, format!("&{}", r)), - ], - Applicability::MachineApplicable, - ); + match is_assign { + IsAssign::No => { + let suggestions = vec![ + if let hir::ExprKind::AddrOf(_, _, lhs_inner_expr) = lhs_expr.kind { + (lhs_expr.span.until(lhs_inner_expr.span), "".to_owned()) + } else { + (lhs_expr.span.shrink_to_hi(), ".to_owned()".to_owned()) + }, + (rhs_expr.span.shrink_to_lo(), "&".to_owned()), + ]; + err.multipart_suggestion(msg, suggestions, Applicability::MachineApplicable); } - _ => { + IsAssign::Yes => { err.help(msg); } - }; + } true } _ => false, diff --git a/src/test/ui/issues/issue-47377.stderr b/src/test/ui/issues/issue-47377.stderr index a7b8b1ca861..2c17a19779f 100644 --- a/src/test/ui/issues/issue-47377.stderr +++ b/src/test/ui/issues/issue-47377.stderr @@ -10,7 +10,7 @@ LL | let _a = b + ", World!"; help: `to_owned()` can be used to create an owned `String` from a string reference. String concatenation appends the string on the right to the string on the left and may require reallocation. This requires ownership of the string on the left | LL | let _a = b.to_owned() + ", World!"; - | ~~~~~~~~~~~~ + | +++++++++++ error: aborting due to previous error diff --git a/src/test/ui/issues/issue-47380.stderr b/src/test/ui/issues/issue-47380.stderr index f6222c77e2e..417206e6cc4 100644 --- a/src/test/ui/issues/issue-47380.stderr +++ b/src/test/ui/issues/issue-47380.stderr @@ -10,7 +10,7 @@ LL | println!("🦀🦀🦀🦀🦀"); let _a = b + ", World!"; help: `to_owned()` can be used to create an owned `String` from a string reference. String concatenation appends the string on the right to the string on the left and may require reallocation. This requires ownership of the string on the left | LL | println!("🦀🦀🦀🦀🦀"); let _a = b.to_owned() + ", World!"; - | ~~~~~~~~~~~~ + | +++++++++++ error: aborting due to previous error diff --git a/src/test/ui/span/issue-39018.stderr b/src/test/ui/span/issue-39018.stderr index 92e86bf5d6c..444d037571e 100644 --- a/src/test/ui/span/issue-39018.stderr +++ b/src/test/ui/span/issue-39018.stderr @@ -10,7 +10,7 @@ LL | let x = "Hello " + "World!"; help: `to_owned()` can be used to create an owned `String` from a string reference. String concatenation appends the string on the right to the string on the left and may require reallocation. This requires ownership of the string on the left | LL | let x = "Hello ".to_owned() + "World!"; - | ~~~~~~~~~~~~~~~~~~~ + | +++++++++++ error[E0369]: cannot add `World` to `World` --> $DIR/issue-39018.rs:8:26 @@ -49,7 +49,7 @@ LL | let x = "Hello " + "World!".to_owned(); help: `to_owned()` can be used to create an owned `String` from a string reference. String concatenation appends the string on the right to the string on the left and may require reallocation. This requires ownership of the string on the left | LL | let x = "Hello ".to_owned() + &"World!".to_owned(); - | ~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~~~~ + | +++++++++++ + error[E0369]: cannot add `&String` to `&String` --> $DIR/issue-39018.rs:26:16 @@ -62,8 +62,9 @@ LL | let _ = &a + &b; | help: String concatenation appends the string on the right to the string on the left and may require reallocation. This requires ownership of the string on the left | -LL | let _ = a + &b; - | ~ +LL - let _ = &a + &b; +LL + let _ = a + &b; + | error[E0369]: cannot add `String` to `&String` --> $DIR/issue-39018.rs:27:16 @@ -76,8 +77,9 @@ LL | let _ = &a + b; | help: `to_owned()` can be used to create an owned `String` from a string reference. String concatenation appends the string on the right to the string on the left and may require reallocation. This requires ownership of the string on the left | -LL | let _ = a + &b; - | ~ ~~ +LL - let _ = &a + b; +LL + let _ = a + &b; + | error[E0308]: mismatched types --> $DIR/issue-39018.rs:29:17 @@ -100,7 +102,7 @@ LL | let _ = e + b; help: `to_owned()` can be used to create an owned `String` from a string reference. String concatenation appends the string on the right to the string on the left and may require reallocation. This requires ownership of the string on the left | LL | let _ = e.to_owned() + &b; - | ~~~~~~~~~~~~ ~~ + | +++++++++++ + error[E0369]: cannot add `&String` to `&String` --> $DIR/issue-39018.rs:31:15 @@ -114,7 +116,7 @@ LL | let _ = e + &b; help: `to_owned()` can be used to create an owned `String` from a string reference. String concatenation appends the string on the right to the string on the left and may require reallocation. This requires ownership of the string on the left | LL | let _ = e.to_owned() + &b; - | ~~~~~~~~~~~~ + | +++++++++++ error[E0369]: cannot add `&str` to `&String` --> $DIR/issue-39018.rs:32:15 @@ -128,7 +130,7 @@ LL | let _ = e + d; help: `to_owned()` can be used to create an owned `String` from a string reference. String concatenation appends the string on the right to the string on the left and may require reallocation. This requires ownership of the string on the left | LL | let _ = e.to_owned() + d; - | ~~~~~~~~~~~~ + | +++++++++++ error[E0369]: cannot add `&&str` to `&String` --> $DIR/issue-39018.rs:33:15 @@ -142,7 +144,7 @@ LL | let _ = e + &d; help: `to_owned()` can be used to create an owned `String` from a string reference. String concatenation appends the string on the right to the string on the left and may require reallocation. This requires ownership of the string on the left | LL | let _ = e.to_owned() + &d; - | ~~~~~~~~~~~~ + | +++++++++++ error[E0369]: cannot add `&&str` to `&&str` --> $DIR/issue-39018.rs:34:16 @@ -172,7 +174,7 @@ LL | let _ = c + &d; help: `to_owned()` can be used to create an owned `String` from a string reference. String concatenation appends the string on the right to the string on the left and may require reallocation. This requires ownership of the string on the left | LL | let _ = c.to_owned() + &d; - | ~~~~~~~~~~~~ + | +++++++++++ error[E0369]: cannot add `&str` to `&str` --> $DIR/issue-39018.rs:37:15 @@ -186,7 +188,7 @@ LL | let _ = c + d; help: `to_owned()` can be used to create an owned `String` from a string reference. String concatenation appends the string on the right to the string on the left and may require reallocation. This requires ownership of the string on the left | LL | let _ = c.to_owned() + d; - | ~~~~~~~~~~~~ + | +++++++++++ error: aborting due to 14 previous errors diff --git a/src/test/ui/str/str-concat-on-double-ref.stderr b/src/test/ui/str/str-concat-on-double-ref.stderr index dee28897f4d..cc9456be901 100644 --- a/src/test/ui/str/str-concat-on-double-ref.stderr +++ b/src/test/ui/str/str-concat-on-double-ref.stderr @@ -10,7 +10,7 @@ LL | let c = a + b; help: `to_owned()` can be used to create an owned `String` from a string reference. String concatenation appends the string on the right to the string on the left and may require reallocation. This requires ownership of the string on the left | LL | let c = a.to_owned() + b; - | ~~~~~~~~~~~~ + | +++++++++++ error: aborting due to previous error diff --git a/src/test/ui/terminal-width/non-1-width-unicode-multiline-label.stderr b/src/test/ui/terminal-width/non-1-width-unicode-multiline-label.stderr index 480f442fedd..2da3db4a7fa 100644 --- a/src/test/ui/terminal-width/non-1-width-unicode-multiline-label.stderr +++ b/src/test/ui/terminal-width/non-1-width-unicode-multiline-label.stderr @@ -10,7 +10,7 @@ LL | ...ཽཾཿ྄ཱྀྀྂྃ྅྆྇ྈྉྊྋྌྍྎྏྐྑྒྒྷྔ help: `to_owned()` can be used to create an owned `String` from a string reference. String concatenation appends the string on the right to the string on the left and may require reallocation. This requires ownership of the string on the left | LL | let _ = "ༀ༁༂༃༄༅༆༇༈༉༊་༌།༎༏༐༑༒༓༔༕༖༗༘༙༚༛༜༝༞༟༠༡༢༣༤༥༦༧༨༩༪༫༬༭༮༯༰༱༲༳༴༵༶༷༸༹༺༻༼༽༾༿ཀཁགགྷངཅཆཇ཈ཉཊཋཌཌྷཎཏཐདདྷནཔཕབབྷམཙཚཛཛྷཝཞཟའཡརལཤཥསཧཨཀྵཪཫཬ཭཮཯཰ཱཱཱིིུུྲྀཷླྀཹེཻོཽཾཿ྄ཱྀྀྂྃ྅྆྇ྈྉྊྋྌྍྎྏྐྑྒྒྷྔྕྖྗ྘ྙྚྛྜྜྷྞྟྠྡྡྷྣྤྥྦྦྷྨྩྪྫྫྷྭྮྯྰྱྲླྴྵྶྷྸྐྵྺྻྼ྽྾྿࿀࿁࿂࿃࿄࿅࿆࿇࿈࿉࿊࿋࿌࿍࿎࿏࿐࿑࿒࿓࿔࿕࿖࿗࿘࿙࿚"; let _a = unicode_is_fun.to_owned() + " really fun!"; - | ~~~~~~~~~~~~~~~~~~~~~~~~~ + | +++++++++++ error: aborting due to previous error