From f874f6768caa8b59b99feffc708e868328129fd5 Mon Sep 17 00:00:00 2001
From: clubby789 <jamie@hill-daniel.co.uk>
Date: Fri, 3 Feb 2023 11:10:24 +0000
Subject: [PATCH] Fix suggestion for coercing Option<&String> to Option<&str>
---
.../locales/en-US/hir_typeck.ftl | 2 +
.../src/fn_ctxt/suggestions.rs | 13 +++--
tests/ui/typeck/issue-89856.fixed | 18 +++++++
tests/ui/typeck/issue-89856.rs | 14 ++++-
tests/ui/typeck/issue-89856.stderr | 54 ++++++++++++++++---
5 files changed, 88 insertions(+), 13 deletions(-)
create mode 100644 tests/ui/typeck/issue-89856.fixed
diff --git a/compiler/rustc_error_messages/locales/en-US/hir_typeck.ftl b/compiler/rustc_error_messages/locales/en-US/hir_typeck.ftl
index 0f13d29d0fc..05ac8db0db8 100644
--- a/compiler/rustc_error_messages/locales/en-US/hir_typeck.ftl
+++ b/compiler/rustc_error_messages/locales/en-US/hir_typeck.ftl
@@ -61,3 +61,5 @@ hir_typeck_lang_start_incorrect_ret_ty = the return type of the `start` lang ite
hir_typeck_help_set_edition_cargo = set `edition = "{$edition}"` in `Cargo.toml`
hir_typeck_help_set_edition_standalone = pass `--edition {$edition}` to `rustc`
hir_typeck_note_edition_guide = for more on editions, read https://doc.rust-lang.org/edition-guide
+
+hir_typeck_convert_to_str = try converting the passed type into a `&str`
diff --git a/compiler/rustc_hir_typeck/src/fn_ctxt/suggestions.rs b/compiler/rustc_hir_typeck/src/fn_ctxt/suggestions.rs
index 6046e55c65c..3f433a0928c 100644
--- a/compiler/rustc_hir_typeck/src/fn_ctxt/suggestions.rs
+++ b/compiler/rustc_hir_typeck/src/fn_ctxt/suggestions.rs
@@ -3,7 +3,7 @@ use super::FnCtxt;
use crate::errors::{AddReturnTypeSuggestion, ExpectedReturnTypeLabel};
use crate::method::probe::{IsSuggestion, Mode, ProbeScope};
use rustc_ast::util::parser::{ExprPrecedence, PREC_POSTFIX};
-use rustc_errors::{Applicability, Diagnostic, MultiSpan};
+use rustc_errors::{fluent, Applicability, Diagnostic, MultiSpan};
use rustc_hir as hir;
use rustc_hir::def::{CtorKind, CtorOf, DefKind};
use rustc_hir::lang_items::LangItem;
@@ -414,11 +414,16 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
if let ty::Adt(adt, _) = peeled.kind()
&& Some(adt.did()) == self.tcx.lang_items().string()
{
+ let sugg = if ref_cnt == 0 {
+ ".as_deref()"
+ } else {
+ ".map(|x| x.as_str())"
+ };
err.span_suggestion_verbose(
expr.span.shrink_to_hi(),
- "try converting the passed type into a `&str`",
- format!(".map(|x| &*{}x)", "*".repeat(ref_cnt)),
- Applicability::MaybeIncorrect,
+ fluent::hir_typeck_convert_to_str,
+ sugg,
+ Applicability::MachineApplicable,
);
return true;
}
diff --git a/tests/ui/typeck/issue-89856.fixed b/tests/ui/typeck/issue-89856.fixed
new file mode 100644
index 00000000000..3e1a006efa0
--- /dev/null
+++ b/tests/ui/typeck/issue-89856.fixed
@@ -0,0 +1,18 @@
+// run-rustfix
+
+fn take_str_maybe(_: Option<&str>) { }
+fn main() {
+ let string = String::from("Hello, world");
+
+ let option: Option<String> = Some(string.clone());
+ take_str_maybe(option.as_deref());
+ //~^ ERROR: mismatched types [E0308]
+
+ let option_ref = Some(&string);
+ take_str_maybe(option_ref.map(|x| x.as_str()));
+ //~^ ERROR: mismatched types [E0308]
+
+ let option_ref_ref = option_ref.as_ref();
+ take_str_maybe(option_ref_ref.map(|x| x.as_str()));
+ //~^ ERROR: mismatched types [E0308]
+}
diff --git a/tests/ui/typeck/issue-89856.rs b/tests/ui/typeck/issue-89856.rs
index b021e349e35..cfe6e19b303 100644
--- a/tests/ui/typeck/issue-89856.rs
+++ b/tests/ui/typeck/issue-89856.rs
@@ -1,8 +1,18 @@
-fn take_str_maybe(x: Option<&str>) -> Option<&str> { None }
+// run-rustfix
+fn take_str_maybe(_: Option<&str>) { }
fn main() {
let string = String::from("Hello, world");
- let option = Some(&string);
+
+ let option: Option<String> = Some(string.clone());
take_str_maybe(option);
//~^ ERROR: mismatched types [E0308]
+
+ let option_ref = Some(&string);
+ take_str_maybe(option_ref);
+ //~^ ERROR: mismatched types [E0308]
+
+ let option_ref_ref = option_ref.as_ref();
+ take_str_maybe(option_ref_ref);
+ //~^ ERROR: mismatched types [E0308]
}
diff --git a/tests/ui/typeck/issue-89856.stderr b/tests/ui/typeck/issue-89856.stderr
index 6b9cbe52c25..bd76f172468 100644
--- a/tests/ui/typeck/issue-89856.stderr
+++ b/tests/ui/typeck/issue-89856.stderr
@@ -1,23 +1,63 @@
error[E0308]: mismatched types
- --> $DIR/issue-89856.rs:6:20
+ --> $DIR/issue-89856.rs:8:20
|
LL | take_str_maybe(option);
- | -------------- ^^^^^^ expected `Option<&str>`, found `Option<&String>`
+ | -------------- ^^^^^^ expected `Option<&str>`, found `Option<String>`
+ | |
+ | arguments to this function are incorrect
+ |
+ = note: expected enum `Option<&str>`
+ found enum `Option<String>`
+note: function defined here
+ --> $DIR/issue-89856.rs:3:4
+ |
+LL | fn take_str_maybe(_: Option<&str>) { }
+ | ^^^^^^^^^^^^^^ ---------------
+help: try converting the passed type into a `&str`
+ |
+LL | take_str_maybe(option.as_deref());
+ | +++++++++++
+
+error[E0308]: mismatched types
+ --> $DIR/issue-89856.rs:12:20
+ |
+LL | take_str_maybe(option_ref);
+ | -------------- ^^^^^^^^^^ expected `Option<&str>`, found `Option<&String>`
| |
| arguments to this function are incorrect
|
= note: expected enum `Option<&str>`
found enum `Option<&String>`
note: function defined here
- --> $DIR/issue-89856.rs:1:4
+ --> $DIR/issue-89856.rs:3:4
|
-LL | fn take_str_maybe(x: Option<&str>) -> Option<&str> { None }
+LL | fn take_str_maybe(_: Option<&str>) { }
| ^^^^^^^^^^^^^^ ---------------
help: try converting the passed type into a `&str`
|
-LL | take_str_maybe(option.map(|x| &**x));
- | ++++++++++++++
+LL | take_str_maybe(option_ref.map(|x| x.as_str()));
+ | ++++++++++++++++++++
-error: aborting due to previous error
+error[E0308]: mismatched types
+ --> $DIR/issue-89856.rs:16:20
+ |
+LL | take_str_maybe(option_ref_ref);
+ | -------------- ^^^^^^^^^^^^^^ expected `Option<&str>`, found `Option<&&String>`
+ | |
+ | arguments to this function are incorrect
+ |
+ = note: expected enum `Option<&str>`
+ found enum `Option<&&String>`
+note: function defined here
+ --> $DIR/issue-89856.rs:3:4
+ |
+LL | fn take_str_maybe(_: Option<&str>) { }
+ | ^^^^^^^^^^^^^^ ---------------
+help: try converting the passed type into a `&str`
+ |
+LL | take_str_maybe(option_ref_ref.map(|x| x.as_str()));
+ | ++++++++++++++++++++
+
+error: aborting due to 3 previous errors
For more information about this error, try `rustc --explain E0308`.