Rollup merge of #57067 - Centril:stabilize-min_const_unsafe_fn, r=oli-obk

Stabilize min_const_unsafe_fn in 1.33

Fixes #55607

r? @oli-obk

8 files changed, 75 insertions, 146 deletions

diff --git a/src/test/ui/consts/min_const_fn/min_const_fn_unsafe.rs b/src/test/ui/consts/min_const_fn/min_const_fn_unsafe.rs
index 92e99c6228a..da875fe7a6b 100644
--- a/src/test/ui/consts/min_const_fn/min_const_fn_unsafe.rs
+++ b/src/test/ui/consts/min_const_fn/min_const_fn_unsafe.rs
@@ -8,27 +8,62 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-// gate-test-min_const_unsafe_fn
+//------------------------------------------------------------------------------
+// OK
+//------------------------------------------------------------------------------
 
-// ok
 const unsafe fn ret_i32_no_unsafe() -> i32 { 42 }
 const unsafe fn ret_null_ptr_no_unsafe<T>() -> *const T { 0 as *const T }
 const unsafe fn ret_null_mut_ptr_no_unsafe<T>() -> *mut T { 0 as *mut T }
 const fn no_unsafe() { unsafe {} }
 
-// not ok
 const fn call_unsafe_const_fn() -> i32 {
-    unsafe { ret_i32_no_unsafe() } //~ ERROR calls to `const unsafe fn` in const fns are unstable
+    unsafe { ret_i32_no_unsafe() }
 }
 const fn call_unsafe_generic_const_fn() -> *const String {
     unsafe { ret_null_ptr_no_unsafe::<String>() }
-    //~^ ERROR calls to `const unsafe fn` in const fns are unstable
 }
-const fn call_unsafe_generic_cell_const_fn() -> *const Vec<std::cell::Cell<u32>> {
+const fn call_unsafe_generic_cell_const_fn()
+    -> *const Vec<std::cell::Cell<u32>>
+{
     unsafe { ret_null_mut_ptr_no_unsafe::<Vec<std::cell::Cell<u32>>>() }
-    //~^ ERROR calls to `const unsafe fn` in const fns
 }
-const unsafe fn deref_forbidden(x: *mut usize) -> usize { *x }
+
+const unsafe fn call_unsafe_const_unsafe_fn() -> i32 {
+    unsafe { ret_i32_no_unsafe() }
+}
+const unsafe fn call_unsafe_generic_const_unsafe_fn() -> *const String {
+    unsafe { ret_null_ptr_no_unsafe::<String>() }
+}
+const unsafe fn call_unsafe_generic_cell_const_unsafe_fn()
+    -> *const Vec<std::cell::Cell<u32>>
+{
+    unsafe { ret_null_mut_ptr_no_unsafe::<Vec<std::cell::Cell<u32>>>() }
+}
+
+const unsafe fn call_unsafe_const_unsafe_fn_immediate() -> i32 {
+    ret_i32_no_unsafe()
+}
+const unsafe fn call_unsafe_generic_const_unsafe_fn_immediate() -> *const String {
+    ret_null_ptr_no_unsafe::<String>()
+}
+const unsafe fn call_unsafe_generic_cell_const_unsafe_fn_immediate()
+    -> *const Vec<std::cell::Cell<u32>>
+{
+    ret_null_mut_ptr_no_unsafe::<Vec<std::cell::Cell<u32>>>()
+}
+
+//------------------------------------------------------------------------------
+// NOT OK
+//------------------------------------------------------------------------------
+
+const fn bad_const_fn_deref_raw(x: *mut usize) -> &'static usize { unsafe { &*x } } //~ is unsafe
+//~^ dereferencing raw pointers in constant functions
+
+const unsafe fn bad_const_unsafe_deref_raw(x: *mut usize) -> usize { *x }
+//~^ dereferencing raw pointers in constant functions
+
+const unsafe fn bad_const_unsafe_deref_raw_ref(x: *mut usize) -> &'static usize { &*x }
 //~^ dereferencing raw pointers in constant functions
 
 fn main() {}
diff --git a/src/test/ui/consts/min_const_fn/min_const_fn_unsafe.stderr b/src/test/ui/consts/min_const_fn/min_const_fn_unsafe.stderr
index fafc89d1493..68b782bf0e7 100644
--- a/src/test/ui/consts/min_const_fn/min_const_fn_unsafe.stderr
+++ b/src/test/ui/consts/min_const_fn/min_const_fn_unsafe.stderr
@@ -1,43 +1,44 @@
 error[E0658]: dereferencing raw pointers in constant functions is unstable (see issue #51911)
-  --> $DIR/min_const_fn_unsafe.rs:31:59
+  --> $DIR/min_const_fn_unsafe.rs:60:77
    |
-LL | const unsafe fn deref_forbidden(x: *mut usize) -> usize { *x }
-   |                                                           ^^
+LL | const fn bad_const_fn_deref_raw(x: *mut usize) -> &'static usize { unsafe { &*x } } //~ is unsafe
+   |                                                                             ^^^
    |
    = help: add #![feature(const_raw_ptr_deref)] to the crate attributes to enable
 
-error[E0658]: unions in const fn are unstable (see issue #51909)
-  --> $DIR/min_const_fn_unsafe.rs:38:5
+error[E0658]: dereferencing raw pointers in constant functions is unstable (see issue #51911)
+  --> $DIR/min_const_fn_unsafe.rs:63:70
    |
-LL |     Foo { x: () }.y
-   |     ^^^^^^^^^^^^^^^
+LL | const unsafe fn bad_const_unsafe_deref_raw(x: *mut usize) -> usize { *x }
+   |                                                                      ^^
    |
-   = help: add #![feature(const_fn_union)] to the crate attributes to enable
+   = help: add #![feature(const_raw_ptr_deref)] to the crate attributes to enable
 
-error[E0658]: calls to `const unsafe fn` in const fns are unstable (see issue #55607)
-  --> $DIR/min_const_fn_unsafe.rs:21:14
+error[E0658]: dereferencing raw pointers in constant functions is unstable (see issue #51911)
+  --> $DIR/min_const_fn_unsafe.rs:66:83
    |
-LL |     unsafe { ret_i32_no_unsafe() } //~ ERROR calls to `const unsafe fn` in const fns are unstable
-   |              ^^^^^^^^^^^^^^^^^^^
+LL | const unsafe fn bad_const_unsafe_deref_raw_ref(x: *mut usize) -> &'static usize { &*x }
+   |                                                                                   ^^^
    |
-   = help: add #![feature(min_const_unsafe_fn)] to the crate attributes to enable
+   = help: add #![feature(const_raw_ptr_deref)] to the crate attributes to enable
 
-error[E0658]: calls to `const unsafe fn` in const fns are unstable (see issue #55607)
-  --> $DIR/min_const_fn_unsafe.rs:24:14
+error[E0658]: unions in const fn are unstable (see issue #51909)
+  --> $DIR/min_const_fn_unsafe.rs:73:5
    |
-LL |     unsafe { ret_null_ptr_no_unsafe::<String>() }
-   |              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+LL |     Foo { x: () }.y
+   |     ^^^^^^^^^^^^^^^
    |
-   = help: add #![feature(min_const_unsafe_fn)] to the crate attributes to enable
+   = help: add #![feature(const_fn_union)] to the crate attributes to enable
 
-error[E0658]: calls to `const unsafe fn` in const fns are unstable (see issue #55607)
-  --> $DIR/min_const_fn_unsafe.rs:28:14
+error[E0133]: dereference of raw pointer is unsafe and requires unsafe function or block
+  --> $DIR/min_const_fn_unsafe.rs:60:77
    |
-LL |     unsafe { ret_null_mut_ptr_no_unsafe::<Vec<std::cell::Cell<u32>>>() }
-   |              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+LL | const fn bad_const_fn_deref_raw(x: *mut usize) -> &'static usize { unsafe { &*x } } //~ is unsafe
+   |                                                                             ^^^ dereference of raw pointer
    |
-   = help: add #![feature(min_const_unsafe_fn)] to the crate attributes to enable
+   = note: raw pointers may be NULL, dangling or unaligned; they can violate aliasing rules and cause data races: all of these are undefined behavior
 
 error: aborting due to 5 previous errors
 
-For more information about this error, try `rustc --explain E0658`.
+Some errors occurred: E0133, E0658.
+For more information about an error, try `rustc --explain E0133`.
diff --git a/src/test/ui/consts/min_const_fn/min_const_fn_unsafe_feature_gate.rs b/src/test/ui/consts/min_const_fn/min_const_fn_unsafe_feature_gate.rs
deleted file mode 100644
index 67a48206126..00000000000
--- a/src/test/ui/consts/min_const_fn/min_const_fn_unsafe_feature_gate.rs
+++ /dev/null
@@ -1,61 +0,0 @@
-// Copyright 2018 The Rust Project Developers. See the COPYRIGHT
-// file at the top-level directory of this distribution and at
-// http://rust-lang.org/COPYRIGHT.
-//
-// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
-// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
-// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
-// option. This file may not be copied, modified, or distributed
-// except according to those terms.
-
-#![feature(min_const_unsafe_fn)]
-
-// ok
-const unsafe fn foo4() -> i32 { 42 }
-const unsafe fn foo5<T>() -> *const T { 0 as *const T }
-const unsafe fn foo6<T>() -> *mut T { 0 as *mut T }
-const fn no_unsafe() { unsafe {} }
-
-const fn foo8() -> i32 {
-    unsafe { foo4() }
-}
-const fn foo9() -> *const String {
-    unsafe { foo5::<String>() }
-}
-const fn foo10() -> *const Vec<std::cell::Cell<u32>> {
-    unsafe { foo6::<Vec<std::cell::Cell<u32>>>() }
-}
-const unsafe fn foo8_3() -> i32 {
-    unsafe { foo4() }
-}
-const unsafe fn foo9_3() -> *const String {
-    unsafe { foo5::<String>() }
-}
-const unsafe fn foo10_3() -> *const Vec<std::cell::Cell<u32>> {
-    unsafe { foo6::<Vec<std::cell::Cell<u32>>>() }
-}
-const unsafe fn foo8_2() -> i32 {
-    foo4()
-}
-const unsafe fn foo9_2() -> *const String {
-    foo5::<String>()
-}
-const unsafe fn foo10_2() -> *const Vec<std::cell::Cell<u32>> {
-    foo6::<Vec<std::cell::Cell<u32>>>()
-}
-const unsafe fn foo30_3(x: *mut usize) -> usize { *x }
-//~^ dereferencing raw pointers in constant functions
-
-const unsafe fn foo30_4(x: *mut usize) -> &'static usize { &*x }
-//~^ dereferencing raw pointers in constant functions
-
-const fn foo30_5(x: *mut usize) -> &'static usize { unsafe { &*x } } //~ is unsafe
-//~^ dereferencing raw pointers in constant functions
-
-fn main() {}
-
-const unsafe fn no_union() {
-    union Foo { x: (), y: () }
-    Foo { x: () }.y
-    //~^ unions in const fn
-}
diff --git a/src/test/ui/consts/min_const_fn/min_const_fn_unsafe_feature_gate.stderr b/src/test/ui/consts/min_const_fn/min_const_fn_unsafe_feature_gate.stderr
deleted file mode 100644
index 63bf9a53e50..00000000000
--- a/src/test/ui/consts/min_const_fn/min_const_fn_unsafe_feature_gate.stderr
+++ /dev/null
@@ -1,44 +0,0 @@
-error[E0658]: dereferencing raw pointers in constant functions is unstable (see issue #51911)
-  --> $DIR/min_const_fn_unsafe_feature_gate.rs:46:51
-   |
-LL | const unsafe fn foo30_3(x: *mut usize) -> usize { *x }
-   |                                                   ^^
-   |
-   = help: add #![feature(const_raw_ptr_deref)] to the crate attributes to enable
-
-error[E0658]: dereferencing raw pointers in constant functions is unstable (see issue #51911)
-  --> $DIR/min_const_fn_unsafe_feature_gate.rs:49:60
-   |
-LL | const unsafe fn foo30_4(x: *mut usize) -> &'static usize { &*x }
-   |                                                            ^^^
-   |
-   = help: add #![feature(const_raw_ptr_deref)] to the crate attributes to enable
-
-error[E0658]: dereferencing raw pointers in constant functions is unstable (see issue #51911)
-  --> $DIR/min_const_fn_unsafe_feature_gate.rs:52:62
-   |
-LL | const fn foo30_5(x: *mut usize) -> &'static usize { unsafe { &*x } } //~ is unsafe
-   |                                                              ^^^
-   |
-   = help: add #![feature(const_raw_ptr_deref)] to the crate attributes to enable
-
-error[E0658]: unions in const fn are unstable (see issue #51909)
-  --> $DIR/min_const_fn_unsafe_feature_gate.rs:59:5
-   |
-LL |     Foo { x: () }.y
-   |     ^^^^^^^^^^^^^^^
-   |
-   = help: add #![feature(const_fn_union)] to the crate attributes to enable
-
-error[E0133]: dereference of raw pointer is unsafe and requires unsafe function or block
-  --> $DIR/min_const_fn_unsafe_feature_gate.rs:52:62
-   |
-LL | const fn foo30_5(x: *mut usize) -> &'static usize { unsafe { &*x } } //~ is unsafe
-   |                                                              ^^^ dereference of raw pointer
-   |
-   = note: raw pointers may be NULL, dangling or unaligned; they can violate aliasing rules and cause data races: all of these are undefined behavior
-
-error: aborting due to 5 previous errors
-
-Some errors occurred: E0133, E0658.
-For more information about an error, try `rustc --explain E0133`.
diff --git a/src/test/ui/consts/min_const_fn/min_const_unsafe_fn_libstd_stability.rs b/src/test/ui/consts/min_const_fn/min_const_unsafe_fn_libstd_stability.rs
index f559c23ff0f..33fcea98189 100644
--- a/src/test/ui/consts/min_const_fn/min_const_unsafe_fn_libstd_stability.rs
+++ b/src/test/ui/consts/min_const_fn/min_const_unsafe_fn_libstd_stability.rs
@@ -14,7 +14,6 @@
             issue = "0")]
 
 #![feature(rustc_const_unstable, const_fn, foo, foo2)]
-#![feature(min_const_unsafe_fn)]
 #![feature(staged_api)]
 
 #[stable(feature = "rust1", since = "1.0.0")]
diff --git a/src/test/ui/consts/min_const_fn/min_const_unsafe_fn_libstd_stability.stderr b/src/test/ui/consts/min_const_fn/min_const_unsafe_fn_libstd_stability.stderr
index 37be2889173..2a0ef0e6b96 100644
--- a/src/test/ui/consts/min_const_fn/min_const_unsafe_fn_libstd_stability.stderr
+++ b/src/test/ui/consts/min_const_fn/min_const_unsafe_fn_libstd_stability.stderr
@@ -1,23 +1,23 @@
 error: can only call other `min_const_fn` within a `min_const_fn`
-  --> $DIR/min_const_unsafe_fn_libstd_stability.rs:26:41
+  --> $DIR/min_const_unsafe_fn_libstd_stability.rs:25:41
    |
 LL | const unsafe fn bar() -> u32 { unsafe { foo() } } //~ ERROR can only call other `min_const_fn`
    |                                         ^^^^^
 
 error: can only call other `min_const_fn` within a `min_const_fn`
-  --> $DIR/min_const_unsafe_fn_libstd_stability.rs:33:42
+  --> $DIR/min_const_unsafe_fn_libstd_stability.rs:32:42
    |
 LL | const unsafe fn bar2() -> u32 { unsafe { foo2() } } //~ ERROR can only call other `min_const_fn`
    |                                          ^^^^^^
 
 error: only int, `bool` and `char` operations are stable in const fn
-  --> $DIR/min_const_unsafe_fn_libstd_stability.rs:37:33
+  --> $DIR/min_const_unsafe_fn_libstd_stability.rs:36:33
    |
 LL | const unsafe fn bar3() -> u32 { (5f32 + 6f32) as u32 } //~ ERROR only int, `bool` and `char` op
    |                                 ^^^^^^^^^^^^^
 
 error: can only call other `min_const_fn` within a `min_const_fn`
-  --> $DIR/min_const_unsafe_fn_libstd_stability.rs:45:48
+  --> $DIR/min_const_unsafe_fn_libstd_stability.rs:44:48
    |
 LL | const unsafe fn bar2_gated() -> u32 { unsafe { foo2_gated() } } //~ ERROR can only call other
    |                                                ^^^^^^^^^^^^
diff --git a/src/test/ui/consts/min_const_fn/min_const_unsafe_fn_libstd_stability2.rs b/src/test/ui/consts/min_const_fn/min_const_unsafe_fn_libstd_stability2.rs
index 131bc97c85a..68205edd63b 100644
--- a/src/test/ui/consts/min_const_fn/min_const_unsafe_fn_libstd_stability2.rs
+++ b/src/test/ui/consts/min_const_fn/min_const_unsafe_fn_libstd_stability2.rs
@@ -14,7 +14,6 @@
             issue = "0")]
 
 #![feature(rustc_const_unstable, const_fn, foo, foo2)]
-#![feature(min_const_unsafe_fn)]
 #![feature(staged_api)]
 
 #[stable(feature = "rust1", since = "1.0.0")]
diff --git a/src/test/ui/consts/min_const_fn/min_const_unsafe_fn_libstd_stability2.stderr b/src/test/ui/consts/min_const_fn/min_const_unsafe_fn_libstd_stability2.stderr
index 0b58dc1294b..61533015185 100644
--- a/src/test/ui/consts/min_const_fn/min_const_unsafe_fn_libstd_stability2.stderr
+++ b/src/test/ui/consts/min_const_fn/min_const_unsafe_fn_libstd_stability2.stderr
@@ -1,17 +1,17 @@
 error: can only call other `min_const_fn` within a `min_const_fn`
-  --> $DIR/min_const_unsafe_fn_libstd_stability2.rs:26:32
+  --> $DIR/min_const_unsafe_fn_libstd_stability2.rs:25:32
    |
 LL | const unsafe fn bar() -> u32 { foo() } //~ ERROR can only call other `min_const_fn`
    |                                ^^^^^
 
 error: can only call other `min_const_fn` within a `min_const_fn`
-  --> $DIR/min_const_unsafe_fn_libstd_stability2.rs:33:33
+  --> $DIR/min_const_unsafe_fn_libstd_stability2.rs:32:33
    |
 LL | const unsafe fn bar2() -> u32 { foo2() } //~ ERROR can only call other `min_const_fn`
    |                                 ^^^^^^
 
 error: can only call other `min_const_fn` within a `min_const_fn`
-  --> $DIR/min_const_unsafe_fn_libstd_stability2.rs:41:39
+  --> $DIR/min_const_unsafe_fn_libstd_stability2.rs:40:39
    |
 LL | const unsafe fn bar2_gated() -> u32 { foo2_gated() } //~ ERROR can only call other `min_const_fn`
    |                                       ^^^^^^^^^^^^