From bf66723c0ecbadc3b4b24da44fa02b7ea3cd73bb Mon Sep 17 00:00:00 2001
From: Michael Goulet <michael@errs.io>
Date: Mon, 28 Aug 2023 02:37:38 +0000
Subject: [PATCH] Test and note unsafe ctor to fn ptr coercion
Also remove a note that I don't consider to be very useful in context.
---
.../src/infer/error_reporting/note_and_explain.rs | 10 ++++------
.../two-mismatch-notes.stderr | 1 -
tests/ui/c-variadic/variadic-ffi-1.stderr | 2 --
tests/ui/fn/fn-pointer-mismatch.stderr | 1 -
.../fn/signature-error-reporting-under-verbose.rs | 1 -
...signature-error-reporting-under-verbose.stderr | 1 -
tests/ui/issues/issue-10764.stderr | 1 -
tests/ui/mismatched_types/normalize-fn-sig.stderr | 1 -
...ion-lifetime-bounds-on-fns-where-clause.stderr | 1 -
...ple-lifetime-bounds-on-fns-where-clause.stderr | 1 -
...regions-fn-subtyping-return-static-fail.stderr | 1 -
.../regions/regions-lifetime-bounds-on-fns.stderr | 1 -
tests/ui/reify-intrinsic.stderr | 1 -
.../rfc-2396-target_feature-11/fn-ptr.mir.stderr | 1 -
.../rfc-2396-target_feature-11/fn-ptr.thir.stderr | 1 -
tests/ui/static/static-reference-to-fn-1.stderr | 1 -
tests/ui/unsafe/ranged-ctor-as-fn-ptr.rs | 10 ++++++++++
tests/ui/unsafe/ranged-ctor-as-fn-ptr.stderr | 15 +++++++++++++++
18 files changed, 29 insertions(+), 22 deletions(-)
create mode 100644 tests/ui/unsafe/ranged-ctor-as-fn-ptr.rs
create mode 100644 tests/ui/unsafe/ranged-ctor-as-fn-ptr.stderr
diff --git a/compiler/rustc_infer/src/infer/error_reporting/note_and_explain.rs b/compiler/rustc_infer/src/infer/error_reporting/note_and_explain.rs
index 372539d73b1..445f68160d2 100644
--- a/compiler/rustc_infer/src/infer/error_reporting/note_and_explain.rs
+++ b/compiler/rustc_infer/src/infer/error_reporting/note_and_explain.rs
@@ -266,12 +266,10 @@ impl<T> Trait<T> for X {
}
}
}
- (ty::FnPtr(_), ty::FnDef(def, _))
- if let hir::def::DefKind::Fn = tcx.def_kind(def) => {
- diag.note(
- "when the arguments and return types match, functions can be coerced \
- to function pointers",
- );
+ (ty::FnPtr(sig), ty::FnDef(def_id, _)) | (ty::FnDef(def_id, _), ty::FnPtr(sig)) => {
+ if tcx.fn_sig(*def_id).skip_binder().unsafety() < sig.unsafety() {
+ diag.note("unsafe functions cannot be coerced into safe function pointers");
+ }
}
_ => {}
}
diff --git a/tests/ui/argument-suggestions/two-mismatch-notes.stderr b/tests/ui/argument-suggestions/two-mismatch-notes.stderr
index 38cf23ddc38..70cc60255c7 100644
--- a/tests/ui/argument-suggestions/two-mismatch-notes.stderr
+++ b/tests/ui/argument-suggestions/two-mismatch-notes.stderr
@@ -11,7 +11,6 @@ LL | foo(f, w);
| ^
= note: expected fn pointer `fn(i32)`
found fn item `fn(u32) {f}`
- = note: when the arguments and return types match, functions can be coerced to function pointers
note: expected `Wrapper<i32>`, found `Wrapper<isize>`
--> $DIR/two-mismatch-notes.rs:10:12
|
diff --git a/tests/ui/c-variadic/variadic-ffi-1.stderr b/tests/ui/c-variadic/variadic-ffi-1.stderr
index c7899338197..4beea83d8a5 100644
--- a/tests/ui/c-variadic/variadic-ffi-1.stderr
+++ b/tests/ui/c-variadic/variadic-ffi-1.stderr
@@ -46,7 +46,6 @@ LL | let x: unsafe extern "C" fn(f: isize, x: u8) = foo;
|
= note: expected fn pointer `unsafe extern "C" fn(_, _)`
found fn item `unsafe extern "C" fn(_, _, ...) {foo}`
- = note: when the arguments and return types match, functions can be coerced to function pointers
error[E0308]: mismatched types
--> $DIR/variadic-ffi-1.rs:26:54
@@ -58,7 +57,6 @@ LL | let y: extern "C" fn(f: isize, x: u8, ...) = bar;
|
= note: expected fn pointer `extern "C" fn(_, _, ...)`
found fn item `extern "C" fn(_, _) {bar}`
- = note: when the arguments and return types match, functions can be coerced to function pointers
error[E0617]: can't pass `f32` to variadic function
--> $DIR/variadic-ffi-1.rs:28:19
diff --git a/tests/ui/fn/fn-pointer-mismatch.stderr b/tests/ui/fn/fn-pointer-mismatch.stderr
index a674babcb32..87ece845b83 100644
--- a/tests/ui/fn/fn-pointer-mismatch.stderr
+++ b/tests/ui/fn/fn-pointer-mismatch.stderr
@@ -80,7 +80,6 @@ LL | let e: &fn(u32) -> u32 = &foo;
= note: expected reference `&fn(u32) -> u32`
found reference `&fn(u32) -> u32 {foo}`
= note: fn items are distinct from fn pointers
- = note: when the arguments and return types match, functions can be coerced to function pointers
help: consider casting to a fn pointer
|
LL | let e: &fn(u32) -> u32 = &(foo as fn(u32) -> u32);
diff --git a/tests/ui/fn/signature-error-reporting-under-verbose.rs b/tests/ui/fn/signature-error-reporting-under-verbose.rs
index 12ff113c913..d00cbd8a0f2 100644
--- a/tests/ui/fn/signature-error-reporting-under-verbose.rs
+++ b/tests/ui/fn/signature-error-reporting-under-verbose.rs
@@ -12,5 +12,4 @@ fn main() {
//~| NOTE expected fn pointer, found fn item
//~| NOTE expected fn pointer `fn(i32, u32)`
//~| NOTE arguments to this function are incorrect
- //~| NOTE when the arguments and return types match, functions can be coerced to function pointers
}
diff --git a/tests/ui/fn/signature-error-reporting-under-verbose.stderr b/tests/ui/fn/signature-error-reporting-under-verbose.stderr
index f4498db7259..067ee824d5d 100644
--- a/tests/ui/fn/signature-error-reporting-under-verbose.stderr
+++ b/tests/ui/fn/signature-error-reporting-under-verbose.stderr
@@ -8,7 +8,6 @@ LL | needs_ptr(foo);
|
= note: expected fn pointer `fn(i32, u32)`
found fn item `fn(i32, i32) {foo}`
- = note: when the arguments and return types match, functions can be coerced to function pointers
note: function defined here
--> $DIR/signature-error-reporting-under-verbose.rs:5:4
|
diff --git a/tests/ui/issues/issue-10764.stderr b/tests/ui/issues/issue-10764.stderr
index fcb45affe2c..4d8a85a1397 100644
--- a/tests/ui/issues/issue-10764.stderr
+++ b/tests/ui/issues/issue-10764.stderr
@@ -8,7 +8,6 @@ LL | fn main() { f(bar) }
|
= note: expected fn pointer `fn()`
found fn item `extern "C" fn() {bar}`
- = note: when the arguments and return types match, functions can be coerced to function pointers
note: function defined here
--> $DIR/issue-10764.rs:1:4
|
diff --git a/tests/ui/mismatched_types/normalize-fn-sig.stderr b/tests/ui/mismatched_types/normalize-fn-sig.stderr
index e3a0646550c..252e56387ba 100644
--- a/tests/ui/mismatched_types/normalize-fn-sig.stderr
+++ b/tests/ui/mismatched_types/normalize-fn-sig.stderr
@@ -8,7 +8,6 @@ LL | needs_i32_ref_fn(foo::<()>);
|
= note: expected fn pointer `fn(&'static i32, i32)`
found fn item `fn(i32, &'static i32) {foo::<()>}`
- = note: when the arguments and return types match, functions can be coerced to function pointers
note: function defined here
--> $DIR/normalize-fn-sig.rs:11:4
|
diff --git a/tests/ui/regions/region-lifetime-bounds-on-fns-where-clause.stderr b/tests/ui/regions/region-lifetime-bounds-on-fns-where-clause.stderr
index f2328cf3b24..a9a92b7a695 100644
--- a/tests/ui/regions/region-lifetime-bounds-on-fns-where-clause.stderr
+++ b/tests/ui/regions/region-lifetime-bounds-on-fns-where-clause.stderr
@@ -8,7 +8,6 @@ LL | let _: fn(&mut &isize, &mut &isize) = a;
|
= note: expected fn pointer `for<'a, 'b, 'c, 'd> fn(&'a mut &'b isize, &'c mut &'d isize)`
found fn item `for<'a, 'b> fn(&'a mut &isize, &'b mut &isize) {a::<'_, '_>}`
- = note: when the arguments and return types match, functions can be coerced to function pointers
error: aborting due to previous error
diff --git a/tests/ui/regions/region-multiple-lifetime-bounds-on-fns-where-clause.stderr b/tests/ui/regions/region-multiple-lifetime-bounds-on-fns-where-clause.stderr
index 9c5004981d5..e96559937d4 100644
--- a/tests/ui/regions/region-multiple-lifetime-bounds-on-fns-where-clause.stderr
+++ b/tests/ui/regions/region-multiple-lifetime-bounds-on-fns-where-clause.stderr
@@ -8,7 +8,6 @@ LL | let _: fn(&mut &isize, &mut &isize, &mut &isize) = a;
|
= note: expected fn pointer `for<'a, 'b, 'c, 'd, 'e, 'f> fn(&'a mut &'b isize, &'c mut &'d isize, &'e mut &'f isize)`
found fn item `for<'a, 'b, 'c> fn(&'a mut &isize, &'b mut &isize, &'c mut &isize) {a::<'_, '_, '_>}`
- = note: when the arguments and return types match, functions can be coerced to function pointers
error: aborting due to previous error
diff --git a/tests/ui/regions/regions-fn-subtyping-return-static-fail.stderr b/tests/ui/regions/regions-fn-subtyping-return-static-fail.stderr
index 766a3d0337c..8d82ff958ff 100644
--- a/tests/ui/regions/regions-fn-subtyping-return-static-fail.stderr
+++ b/tests/ui/regions/regions-fn-subtyping-return-static-fail.stderr
@@ -8,7 +8,6 @@ LL | want_G(baz);
|
= note: expected fn pointer `for<'cx> fn(&'cx S) -> &'static S`
found fn item `for<'a> fn(&'a S) -> &'a S {baz}`
- = note: when the arguments and return types match, functions can be coerced to function pointers
note: function defined here
--> $DIR/regions-fn-subtyping-return-static-fail.rs:20:4
|
diff --git a/tests/ui/regions/regions-lifetime-bounds-on-fns.stderr b/tests/ui/regions/regions-lifetime-bounds-on-fns.stderr
index 2fab2986567..53a5612d24f 100644
--- a/tests/ui/regions/regions-lifetime-bounds-on-fns.stderr
+++ b/tests/ui/regions/regions-lifetime-bounds-on-fns.stderr
@@ -8,7 +8,6 @@ LL | let _: fn(&mut &isize, &mut &isize) = a;
|
= note: expected fn pointer `for<'a, 'b, 'c, 'd> fn(&'a mut &'b isize, &'c mut &'d isize)`
found fn item `for<'a, 'b> fn(&'a mut &isize, &'b mut &isize) {a::<'_, '_>}`
- = note: when the arguments and return types match, functions can be coerced to function pointers
error: aborting due to previous error
diff --git a/tests/ui/reify-intrinsic.stderr b/tests/ui/reify-intrinsic.stderr
index 9f9034a30c7..310b6c224e0 100644
--- a/tests/ui/reify-intrinsic.stderr
+++ b/tests/ui/reify-intrinsic.stderr
@@ -8,7 +8,6 @@ LL | let _: unsafe extern "rust-intrinsic" fn(isize) -> usize = std::mem::tr
|
= note: expected fn pointer `unsafe extern "rust-intrinsic" fn(isize) -> usize`
found fn item `unsafe extern "rust-intrinsic" fn(_) -> _ {transmute::<_, _>}`
- = note: when the arguments and return types match, functions can be coerced to function pointers
error[E0606]: casting `unsafe extern "rust-intrinsic" fn(_) -> _ {transmute::<_, _>}` as `unsafe extern "rust-intrinsic" fn(isize) -> usize` is invalid
--> $DIR/reify-intrinsic.rs:11:13
diff --git a/tests/ui/rfcs/rfc-2396-target_feature-11/fn-ptr.mir.stderr b/tests/ui/rfcs/rfc-2396-target_feature-11/fn-ptr.mir.stderr
index b0ac5dc44ad..e08ffe42d6a 100644
--- a/tests/ui/rfcs/rfc-2396-target_feature-11/fn-ptr.mir.stderr
+++ b/tests/ui/rfcs/rfc-2396-target_feature-11/fn-ptr.mir.stderr
@@ -13,7 +13,6 @@ LL | let foo: fn() = foo;
found fn item `fn() {foo}`
= note: fn items are distinct from fn pointers
= note: functions with `#[target_feature]` can only be coerced to `unsafe` function pointers
- = note: when the arguments and return types match, functions can be coerced to function pointers
help: consider casting to a fn pointer
|
LL | let foo: fn() = foo as fn();
diff --git a/tests/ui/rfcs/rfc-2396-target_feature-11/fn-ptr.thir.stderr b/tests/ui/rfcs/rfc-2396-target_feature-11/fn-ptr.thir.stderr
index b0ac5dc44ad..e08ffe42d6a 100644
--- a/tests/ui/rfcs/rfc-2396-target_feature-11/fn-ptr.thir.stderr
+++ b/tests/ui/rfcs/rfc-2396-target_feature-11/fn-ptr.thir.stderr
@@ -13,7 +13,6 @@ LL | let foo: fn() = foo;
found fn item `fn() {foo}`
= note: fn items are distinct from fn pointers
= note: functions with `#[target_feature]` can only be coerced to `unsafe` function pointers
- = note: when the arguments and return types match, functions can be coerced to function pointers
help: consider casting to a fn pointer
|
LL | let foo: fn() = foo as fn();
diff --git a/tests/ui/static/static-reference-to-fn-1.stderr b/tests/ui/static/static-reference-to-fn-1.stderr
index b68352b5183..86c4eaa7eb4 100644
--- a/tests/ui/static/static-reference-to-fn-1.stderr
+++ b/tests/ui/static/static-reference-to-fn-1.stderr
@@ -7,7 +7,6 @@ LL | func: &foo,
= note: expected reference `&fn() -> Option<isize>`
found reference `&fn() -> Option<isize> {foo}`
= note: fn items are distinct from fn pointers
- = note: when the arguments and return types match, functions can be coerced to function pointers
help: consider casting to a fn pointer
|
LL | func: &(foo as fn() -> Option<isize>),
diff --git a/tests/ui/unsafe/ranged-ctor-as-fn-ptr.rs b/tests/ui/unsafe/ranged-ctor-as-fn-ptr.rs
new file mode 100644
index 00000000000..a91e579510d
--- /dev/null
+++ b/tests/ui/unsafe/ranged-ctor-as-fn-ptr.rs
@@ -0,0 +1,10 @@
+#![feature(rustc_attrs)]
+
+#[derive(Debug)]
+#[rustc_layout_scalar_valid_range_start(2)]
+struct NonZeroAndOneU8(u8);
+
+fn main() {
+ let x: fn(u8) -> NonZeroAndOneU8 = NonZeroAndOneU8;
+ //~^ ERROR mismatched types
+}
diff --git a/tests/ui/unsafe/ranged-ctor-as-fn-ptr.stderr b/tests/ui/unsafe/ranged-ctor-as-fn-ptr.stderr
new file mode 100644
index 00000000000..660c4070451
--- /dev/null
+++ b/tests/ui/unsafe/ranged-ctor-as-fn-ptr.stderr
@@ -0,0 +1,15 @@
+error[E0308]: mismatched types
+ --> $DIR/ranged-ctor-as-fn-ptr.rs:8:40
+ |
+LL | let x: fn(u8) -> NonZeroAndOneU8 = NonZeroAndOneU8;
+ | ------------------------- ^^^^^^^^^^^^^^^ expected normal fn, found unsafe fn
+ | |
+ | expected due to this
+ |
+ = note: expected fn pointer `fn(_) -> NonZeroAndOneU8`
+ found struct constructor `unsafe fn(_) -> NonZeroAndOneU8 {NonZeroAndOneU8}`
+ = note: unsafe functions cannot be coerced into safe function pointers
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0308`.