From 144b8450735f61270cae223c1fd12e2f605c5b34 Mon Sep 17 00:00:00 2001
From: Guillaume Gomez <guillaume1.gomez@gmail.com>
Date: Tue, 10 Sep 2019 13:48:30 +0200
Subject: [PATCH 1/2] Add long error explanation for E0312
---
src/librustc/error_codes.rs | 34 +++++++++++++++++++++++++++++++++-
1 file changed, 33 insertions(+), 1 deletion(-)
diff --git a/src/librustc/error_codes.rs b/src/librustc/error_codes.rs
index eee33846139e6..f6564f1fcd4c1 100644
--- a/src/librustc/error_codes.rs
+++ b/src/librustc/error_codes.rs
@@ -1347,6 +1347,39 @@ struct Foo<T: 'static> {
```
"##,
+E0312: r##"
+Reference's lifetime of borrowed content doesn't match the expected lifetime.
+
+Erroneous code example:
+
+```compile_fail,E0312
+pub fn opt_str<'a>(maybestr: &'a Option<String>) -> &'static str {
+ if maybestr.is_none() {
+ "(none)"
+ } else {
+ let s: &'a str = maybestr.as_ref().unwrap();
+ s // Invalid lifetime!
+ }
+}
+```
+
+To fix this error, either lessen the expected lifetime or find a way to not have
+to use this reference outside of its current scope (by running the code directly
+in the same block for example?):
+
+```
+// In this case, we can fix the issue by switching from "static" lifetime to 'a
+pub fn opt_str<'a>(maybestr: &'a Option<String>) -> &'a str {
+ if maybestr.is_none() {
+ "(none)"
+ } else {
+ let s: &'a str = maybestr.as_ref().unwrap();
+ s // Ok!
+ }
+}
+```
+"##,
+
E0317: r##"
This error occurs when an `if` expression without an `else` block is used in a
context where a type other than `()` is expected, for example a `let`
@@ -2202,7 +2235,6 @@ static X: u32 = 42;
// E0304, // expected signed integer constant
// E0305, // expected constant
E0311, // thing may not live long enough
- E0312, // lifetime of reference outlives lifetime of borrowed content
E0313, // lifetime of borrowed pointer outlives lifetime of captured
// variable
E0314, // closure outlives stack frame
From cf6a1feda65525b947bfd33279c8b74c00f098c6 Mon Sep 17 00:00:00 2001
From: Guillaume Gomez <guillaume1.gomez@gmail.com>
Date: Thu, 12 Sep 2019 13:25:42 +0200
Subject: [PATCH 2/2] update ui tests
---
src/test/ui/issues/issue-10291.stderr | 1 +
src/test/ui/issues/issue-52533.stderr | 1 +
src/test/ui/lub-if.stderr | 1 +
src/test/ui/lub-match.stderr | 1 +
src/test/ui/nll/issue-52742.stderr | 1 +
src/test/ui/nll/issue-55401.stderr | 1 +
.../ui/nll/user-annotations/constant-in-expr-normalize.stderr | 1 +
.../nll/user-annotations/constant-in-expr-trait-item-1.stderr | 1 +
.../nll/user-annotations/constant-in-expr-trait-item-2.stderr | 1 +
src/test/ui/regions/regions-early-bound-error-method.stderr | 1 +
src/test/ui/regions/regions-early-bound-error.stderr | 1 +
src/test/ui/regions/regions-nested-fns.stderr | 1 +
src/test/ui/regions/regions-static-bound.migrate.stderr | 3 ++-
...ed-closures-infer-argument-types-two-region-pointers.stderr | 1 +
src/test/ui/wf/wf-static-method.stderr | 3 ++-
15 files changed, 17 insertions(+), 2 deletions(-)
diff --git a/src/test/ui/issues/issue-10291.stderr b/src/test/ui/issues/issue-10291.stderr
index 5e63469da59f5..a836593e0da10 100644
--- a/src/test/ui/issues/issue-10291.stderr
+++ b/src/test/ui/issues/issue-10291.stderr
@@ -20,3 +20,4 @@ LL | fn test<'x>(x: &'x isize) {
error: aborting due to previous error
+For more information about this error, try `rustc --explain E0312`.
diff --git a/src/test/ui/issues/issue-52533.stderr b/src/test/ui/issues/issue-52533.stderr
index 1ed740c421e0f..586548002072e 100644
--- a/src/test/ui/issues/issue-52533.stderr
+++ b/src/test/ui/issues/issue-52533.stderr
@@ -17,3 +17,4 @@ LL | foo(|a, b| b)
error: aborting due to previous error
+For more information about this error, try `rustc --explain E0312`.
diff --git a/src/test/ui/lub-if.stderr b/src/test/ui/lub-if.stderr
index bb772d4c6c695..26f756c91833b 100644
--- a/src/test/ui/lub-if.stderr
+++ b/src/test/ui/lub-if.stderr
@@ -26,3 +26,4 @@ LL | pub fn opt_str3<'a>(maybestr: &'a Option<String>) -> &'static str {
error: aborting due to 2 previous errors
+For more information about this error, try `rustc --explain E0312`.
diff --git a/src/test/ui/lub-match.stderr b/src/test/ui/lub-match.stderr
index 090af25143670..0cb0a23c6f2df 100644
--- a/src/test/ui/lub-match.stderr
+++ b/src/test/ui/lub-match.stderr
@@ -26,3 +26,4 @@ LL | pub fn opt_str3<'a>(maybestr: &'a Option<String>) -> &'static str {
error: aborting due to 2 previous errors
+For more information about this error, try `rustc --explain E0312`.
diff --git a/src/test/ui/nll/issue-52742.stderr b/src/test/ui/nll/issue-52742.stderr
index b982915800294..90a35177f4c3b 100644
--- a/src/test/ui/nll/issue-52742.stderr
+++ b/src/test/ui/nll/issue-52742.stderr
@@ -20,3 +20,4 @@ LL | | }
error: aborting due to previous error
+For more information about this error, try `rustc --explain E0312`.
diff --git a/src/test/ui/nll/issue-55401.stderr b/src/test/ui/nll/issue-55401.stderr
index 50debc6386f6a..4ec16ba055a4c 100644
--- a/src/test/ui/nll/issue-55401.stderr
+++ b/src/test/ui/nll/issue-55401.stderr
@@ -13,3 +13,4 @@ LL | fn static_to_a_to_static_through_ref_in_tuple<'a>(x: &'a u32) -> &'static u
error: aborting due to previous error
+For more information about this error, try `rustc --explain E0312`.
diff --git a/src/test/ui/nll/user-annotations/constant-in-expr-normalize.stderr b/src/test/ui/nll/user-annotations/constant-in-expr-normalize.stderr
index f49d68458bea5..0a8ad4221c986 100644
--- a/src/test/ui/nll/user-annotations/constant-in-expr-normalize.stderr
+++ b/src/test/ui/nll/user-annotations/constant-in-expr-normalize.stderr
@@ -13,3 +13,4 @@ LL | fn foo<'a>(_: &'a u32) -> &'static u32 {
error: aborting due to previous error
+For more information about this error, try `rustc --explain E0312`.
diff --git a/src/test/ui/nll/user-annotations/constant-in-expr-trait-item-1.stderr b/src/test/ui/nll/user-annotations/constant-in-expr-trait-item-1.stderr
index 451bcf41e42a9..d596aaf098f77 100644
--- a/src/test/ui/nll/user-annotations/constant-in-expr-trait-item-1.stderr
+++ b/src/test/ui/nll/user-annotations/constant-in-expr-trait-item-1.stderr
@@ -13,3 +13,4 @@ LL | fn foo<'a>(_: &'a u32) -> &'static u32 {
error: aborting due to previous error
+For more information about this error, try `rustc --explain E0312`.
diff --git a/src/test/ui/nll/user-annotations/constant-in-expr-trait-item-2.stderr b/src/test/ui/nll/user-annotations/constant-in-expr-trait-item-2.stderr
index d129e55e1e6f6..80ff9a043d4d5 100644
--- a/src/test/ui/nll/user-annotations/constant-in-expr-trait-item-2.stderr
+++ b/src/test/ui/nll/user-annotations/constant-in-expr-trait-item-2.stderr
@@ -13,3 +13,4 @@ LL | fn foo<'a, T: Foo<'a>>() -> &'static u32 {
error: aborting due to previous error
+For more information about this error, try `rustc --explain E0312`.
diff --git a/src/test/ui/regions/regions-early-bound-error-method.stderr b/src/test/ui/regions/regions-early-bound-error-method.stderr
index 2e5f55f8742cc..7b9f2c9503b2f 100644
--- a/src/test/ui/regions/regions-early-bound-error-method.stderr
+++ b/src/test/ui/regions/regions-early-bound-error-method.stderr
@@ -17,3 +17,4 @@ LL | fn or<'b,G:GetRef<'b>>(&self, g2: G) -> &'a isize {
error: aborting due to previous error
+For more information about this error, try `rustc --explain E0312`.
diff --git a/src/test/ui/regions/regions-early-bound-error.stderr b/src/test/ui/regions/regions-early-bound-error.stderr
index bc52f4bef7eaa..a68355b78f54c 100644
--- a/src/test/ui/regions/regions-early-bound-error.stderr
+++ b/src/test/ui/regions/regions-early-bound-error.stderr
@@ -17,3 +17,4 @@ LL | fn get<'a,'b,G:GetRef<'a, isize>>(g1: G, b: &'b isize) -> &'b isize {
error: aborting due to previous error
+For more information about this error, try `rustc --explain E0312`.
diff --git a/src/test/ui/regions/regions-nested-fns.stderr b/src/test/ui/regions/regions-nested-fns.stderr
index 15c9c9ca4ddbb..904dee6998c9b 100644
--- a/src/test/ui/regions/regions-nested-fns.stderr
+++ b/src/test/ui/regions/regions-nested-fns.stderr
@@ -57,3 +57,4 @@ LL | fn nested<'x>(x: &'x isize) {
error: aborting due to 2 previous errors
+For more information about this error, try `rustc --explain E0312`.
diff --git a/src/test/ui/regions/regions-static-bound.migrate.stderr b/src/test/ui/regions/regions-static-bound.migrate.stderr
index fc8cca929d389..21ead8b768f47 100644
--- a/src/test/ui/regions/regions-static-bound.migrate.stderr
+++ b/src/test/ui/regions/regions-static-bound.migrate.stderr
@@ -30,4 +30,5 @@ LL | static_id_indirect(&v);
error: aborting due to 3 previous errors
-For more information about this error, try `rustc --explain E0621`.
+Some errors have detailed explanations: E0312, E0621.
+For more information about an error, try `rustc --explain E0312`.
diff --git a/src/test/ui/unboxed-closures/unboxed-closures-infer-argument-types-two-region-pointers.stderr b/src/test/ui/unboxed-closures/unboxed-closures-infer-argument-types-two-region-pointers.stderr
index 728efadf4196e..526055ba04b65 100644
--- a/src/test/ui/unboxed-closures/unboxed-closures-infer-argument-types-two-region-pointers.stderr
+++ b/src/test/ui/unboxed-closures/unboxed-closures-infer-argument-types-two-region-pointers.stderr
@@ -23,3 +23,4 @@ LL | | });
error: aborting due to previous error
+For more information about this error, try `rustc --explain E0312`.
diff --git a/src/test/ui/wf/wf-static-method.stderr b/src/test/ui/wf/wf-static-method.stderr
index f82526aa88ebf..3ec90f00448a9 100644
--- a/src/test/ui/wf/wf-static-method.stderr
+++ b/src/test/ui/wf/wf-static-method.stderr
@@ -105,4 +105,5 @@ LL | <IndirectEvil>::static_evil(b)
error: aborting due to 5 previous errors
-For more information about this error, try `rustc --explain E0478`.
+Some errors have detailed explanations: E0312, E0478.
+For more information about an error, try `rustc --explain E0312`.