From bc6330d47a7a81e25f492a837822121a3cd88158 Mon Sep 17 00:00:00 2001
From: Aaron Hill <aa1ronham@gmail.com>
Date: Wed, 12 May 2021 21:39:37 -0400
Subject: [PATCH] Don't suggest adding `'static` lifetime to arguments
Fixes #69350
This is almost always the wrong this to do
---
.../nice_region_error/named_anon_conflict.rs | 16 ++++++++++------
...ounds-static-cant-capture-borrowed.nll.stderr | 2 --
...re-bounds-static-cant-capture-borrowed.stderr | 2 --
.../generator-region-requirements.stderr | 3 ---
.../projection-type-lifetime-mismatch.stderr | 6 ------
src/test/ui/issues/issue-46983.stderr | 2 --
...egion-lbr-anon-does-not-outlive-static.stderr | 2 --
src/test/ui/nll/guarantor-issue-46974.stderr | 3 ---
.../regions-static-bound.migrate.nll.stderr | 5 -----
.../regions/regions-static-bound.migrate.stderr | 5 -----
.../ui/regions/regions-static-bound.nll.stderr | 5 -----
11 files changed, 10 insertions(+), 41 deletions(-)
diff --git a/compiler/rustc_infer/src/infer/error_reporting/nice_region_error/named_anon_conflict.rs b/compiler/rustc_infer/src/infer/error_reporting/nice_region_error/named_anon_conflict.rs
index 2f3c0d6957a..0878f8550da 100644
--- a/compiler/rustc_infer/src/infer/error_reporting/nice_region_error/named_anon_conflict.rs
+++ b/compiler/rustc_infer/src/infer/error_reporting/nice_region_error/named_anon_conflict.rs
@@ -114,12 +114,16 @@ impl<'a, 'tcx> NiceRegionError<'a, 'tcx> {
);
diag.span_label(span, format!("lifetime `{}` required", named));
- diag.span_suggestion(
- new_ty_span,
- &format!("add explicit lifetime `{}` to {}", named, span_label_var),
- new_ty.to_string(),
- Applicability::Unspecified,
- );
+ // Suggesting `'static` is nearly always incorrect, and can steer users
+ // down the wrong path.
+ if *named != ty::ReStatic {
+ diag.span_suggestion(
+ new_ty_span,
+ &format!("add explicit lifetime `{}` to {}", named, span_label_var),
+ new_ty.to_string(),
+ Applicability::Unspecified,
+ );
+ }
Some(diag)
}
diff --git a/src/test/ui/closures/closure-bounds-static-cant-capture-borrowed.nll.stderr b/src/test/ui/closures/closure-bounds-static-cant-capture-borrowed.nll.stderr
index 1d12e2f585e..1b0e0902d67 100644
--- a/src/test/ui/closures/closure-bounds-static-cant-capture-borrowed.nll.stderr
+++ b/src/test/ui/closures/closure-bounds-static-cant-capture-borrowed.nll.stderr
@@ -1,8 +1,6 @@
error[E0621]: explicit lifetime required in the type of `x`
--> $DIR/closure-bounds-static-cant-capture-borrowed.rs:5:5
|
-LL | fn foo(x: &()) {
- | --- help: add explicit lifetime `'static` to the type of `x`: `&'static ()`
LL | / bar(|| {
LL | |
LL | | let _ = x;
diff --git a/src/test/ui/closures/closure-bounds-static-cant-capture-borrowed.stderr b/src/test/ui/closures/closure-bounds-static-cant-capture-borrowed.stderr
index f50c3e3b531..a9add6184f1 100644
--- a/src/test/ui/closures/closure-bounds-static-cant-capture-borrowed.stderr
+++ b/src/test/ui/closures/closure-bounds-static-cant-capture-borrowed.stderr
@@ -1,8 +1,6 @@
error[E0621]: explicit lifetime required in the type of `x`
--> $DIR/closure-bounds-static-cant-capture-borrowed.rs:5:5
|
-LL | fn foo(x: &()) {
- | --- help: add explicit lifetime `'static` to the type of `x`: `&'static ()`
LL | bar(|| {
| ^^^ lifetime `'static` required
diff --git a/src/test/ui/generator/generator-region-requirements.stderr b/src/test/ui/generator/generator-region-requirements.stderr
index 53d48bc4f56..de90a599e76 100644
--- a/src/test/ui/generator/generator-region-requirements.stderr
+++ b/src/test/ui/generator/generator-region-requirements.stderr
@@ -1,9 +1,6 @@
error[E0621]: explicit lifetime required in the type of `x`
--> $DIR/generator-region-requirements.rs:12:51
|
-LL | fn dangle(x: &mut i32) -> &'static mut i32 {
- | -------- help: add explicit lifetime `'static` to the type of `x`: `&'static mut i32`
-...
LL | GeneratorState::Complete(c) => return c,
| ^ lifetime `'static` required
diff --git a/src/test/ui/generic-associated-types/projection-type-lifetime-mismatch.stderr b/src/test/ui/generic-associated-types/projection-type-lifetime-mismatch.stderr
index 13b765dfa57..aec87862566 100644
--- a/src/test/ui/generic-associated-types/projection-type-lifetime-mismatch.stderr
+++ b/src/test/ui/generic-associated-types/projection-type-lifetime-mismatch.stderr
@@ -1,24 +1,18 @@
error[E0621]: explicit lifetime required in the type of `x`
--> $DIR/projection-type-lifetime-mismatch.rs:18:5
|
-LL | fn f(x: &impl for<'a> X<Y<'a> = &'a ()>) -> &'static () {
- | ------------------------------- help: add explicit lifetime `'static` to the type of `x`: `&'static impl for<'a> X<Y<'a> = &'a ()>`
LL | x.m()
| ^^^^^ lifetime `'static` required
error[E0621]: explicit lifetime required in the type of `x`
--> $DIR/projection-type-lifetime-mismatch.rs:23:5
|
-LL | fn g<T: for<'a> X<Y<'a> = &'a ()>>(x: &T) -> &'static () {
- | -- help: add explicit lifetime `'static` to the type of `x`: `&'static T`
LL | x.m()
| ^^^^^ lifetime `'static` required
error[E0621]: explicit lifetime required in the type of `x`
--> $DIR/projection-type-lifetime-mismatch.rs:28:5
|
-LL | fn h(x: &()) -> &'static () {
- | --- help: add explicit lifetime `'static` to the type of `x`: `&'static ()`
LL | x.m()
| ^^^^^ lifetime `'static` required
diff --git a/src/test/ui/issues/issue-46983.stderr b/src/test/ui/issues/issue-46983.stderr
index 8a4a6bdb39f..d328329edad 100644
--- a/src/test/ui/issues/issue-46983.stderr
+++ b/src/test/ui/issues/issue-46983.stderr
@@ -1,8 +1,6 @@
error[E0621]: explicit lifetime required in the type of `x`
--> $DIR/issue-46983.rs:2:5
|
-LL | fn foo(x: &u32) -> &'static u32 {
- | ---- help: add explicit lifetime `'static` to the type of `x`: `&'static u32`
LL | &*x
| ^^^ lifetime `'static` required
diff --git a/src/test/ui/nll/closure-requirements/region-lbr-anon-does-not-outlive-static.stderr b/src/test/ui/nll/closure-requirements/region-lbr-anon-does-not-outlive-static.stderr
index e813f21e01d..4c302d935db 100644
--- a/src/test/ui/nll/closure-requirements/region-lbr-anon-does-not-outlive-static.stderr
+++ b/src/test/ui/nll/closure-requirements/region-lbr-anon-does-not-outlive-static.stderr
@@ -1,8 +1,6 @@
error[E0621]: explicit lifetime required in the type of `x`
--> $DIR/region-lbr-anon-does-not-outlive-static.rs:9:5
|
-LL | fn foo(x: &u32) -> &'static u32 {
- | ---- help: add explicit lifetime `ReStatic` to the type of `x`: `&ReStatic u32`
LL | &*x
| ^^^ lifetime `ReStatic` required
diff --git a/src/test/ui/nll/guarantor-issue-46974.stderr b/src/test/ui/nll/guarantor-issue-46974.stderr
index 361466c4d54..eabc3105c02 100644
--- a/src/test/ui/nll/guarantor-issue-46974.stderr
+++ b/src/test/ui/nll/guarantor-issue-46974.stderr
@@ -12,9 +12,6 @@ LL | *x
error[E0621]: explicit lifetime required in the type of `s`
--> $DIR/guarantor-issue-46974.rs:15:5
|
-LL | fn bar(s: &Box<(i32,)>) -> &'static i32 {
- | ------------ help: add explicit lifetime `'static` to the type of `s`: `&'static Box<(i32,)>`
-LL | // FIXME(#46983): error message should be better
LL | &s.0
| ^^^^ lifetime `'static` required
diff --git a/src/test/ui/regions/regions-static-bound.migrate.nll.stderr b/src/test/ui/regions/regions-static-bound.migrate.nll.stderr
index 6f2c75d2eba..a4c8e721145 100644
--- a/src/test/ui/regions/regions-static-bound.migrate.nll.stderr
+++ b/src/test/ui/regions/regions-static-bound.migrate.nll.stderr
@@ -11,17 +11,12 @@ LL | t
error[E0621]: explicit lifetime required in the type of `u`
--> $DIR/regions-static-bound.rs:14:5
|
-LL | fn error(u: &(), v: &()) {
- | --- help: add explicit lifetime `'static` to the type of `u`: `&'static ()`
LL | static_id(&u);
| ^^^^^^^^^^^^^ lifetime `'static` required
error[E0621]: explicit lifetime required in the type of `v`
--> $DIR/regions-static-bound.rs:16:5
|
-LL | fn error(u: &(), v: &()) {
- | --- help: add explicit lifetime `'static` to the type of `v`: `&'static ()`
-...
LL | static_id_indirect(&v);
| ^^^^^^^^^^^^^^^^^^^^^^ lifetime `'static` required
diff --git a/src/test/ui/regions/regions-static-bound.migrate.stderr b/src/test/ui/regions/regions-static-bound.migrate.stderr
index 6e631d40d45..644458e2063 100644
--- a/src/test/ui/regions/regions-static-bound.migrate.stderr
+++ b/src/test/ui/regions/regions-static-bound.migrate.stderr
@@ -14,17 +14,12 @@ LL | fn static_id_wrong_way<'a>(t: &'a ()) -> &'static () where 'static: 'a {
error[E0621]: explicit lifetime required in the type of `u`
--> $DIR/regions-static-bound.rs:14:5
|
-LL | fn error(u: &(), v: &()) {
- | --- help: add explicit lifetime `'static` to the type of `u`: `&'static ()`
LL | static_id(&u);
| ^^^^^^^^^ lifetime `'static` required
error[E0621]: explicit lifetime required in the type of `v`
--> $DIR/regions-static-bound.rs:16:5
|
-LL | fn error(u: &(), v: &()) {
- | --- help: add explicit lifetime `'static` to the type of `v`: `&'static ()`
-...
LL | static_id_indirect(&v);
| ^^^^^^^^^^^^^^^^^^ lifetime `'static` required
diff --git a/src/test/ui/regions/regions-static-bound.nll.stderr b/src/test/ui/regions/regions-static-bound.nll.stderr
index 6f2c75d2eba..a4c8e721145 100644
--- a/src/test/ui/regions/regions-static-bound.nll.stderr
+++ b/src/test/ui/regions/regions-static-bound.nll.stderr
@@ -11,17 +11,12 @@ LL | t
error[E0621]: explicit lifetime required in the type of `u`
--> $DIR/regions-static-bound.rs:14:5
|
-LL | fn error(u: &(), v: &()) {
- | --- help: add explicit lifetime `'static` to the type of `u`: `&'static ()`
LL | static_id(&u);
| ^^^^^^^^^^^^^ lifetime `'static` required
error[E0621]: explicit lifetime required in the type of `v`
--> $DIR/regions-static-bound.rs:16:5
|
-LL | fn error(u: &(), v: &()) {
- | --- help: add explicit lifetime `'static` to the type of `v`: `&'static ()`
-...
LL | static_id_indirect(&v);
| ^^^^^^^^^^^^^^^^^^^^^^ lifetime `'static` required