Replace unsafe_destructor_blind_to_params with may_dangle

Author: tesuji

src/test/run-pass/issues/issue-24805-dropck-itemless.rs

@@ -1,12 +1,11 @@
 // run-pass
-#![allow(deprecated)]
 
 // Check that item-less traits do not cause dropck to inject extra
 // region constraints.
 
 #![allow(non_camel_case_types)]
 
-#![feature(dropck_parametricity)]
+#![feature(dropck_eyepatch)]
 
 trait UserDefined { }
 
@@ -20,9 +19,8 @@ impl<'a, T> UserDefined for &'a T { }
 //   ```
 macro_rules! impl_drop {
     ($Bound:ident, $Id:ident) => {
-        struct $Id<T:$Bound>(T);
-        impl <T:$Bound> Drop for $Id<T> {
-            #[unsafe_destructor_blind_to_params]
+        struct $Id<T: $Bound>(T);
+        unsafe impl <#[may_dangle] T: $Bound> Drop for $Id<T> {
             fn drop(&mut self) { }
         }
     }

src/test/run-pass/issues/issue-28498-ugeh-ex1.rs

@@ -1,21 +1,19 @@
 // run-pass
-#![allow(deprecated)] // FIXME: switch to `#[may_dangle]` below.
 
 // Example taken from RFC 1238 text
 
 // https://github.com/rust-lang/rfcs/blob/master/text/1238-nonparametric-dropck.md
 //     #example-of-the-unguarded-escape-hatch
 
-#![feature(dropck_parametricity)]
+#![feature(dropck_eyepatch)]
 use std::cell::Cell;
 
 struct Concrete<'a>(u32, Cell<Option<&'a Concrete<'a>>>);
 
 struct Foo<T> { data: Vec<T> }
 
-impl<T> Drop for Foo<T> {
-    // Below is the UGEH attribute
-    #[unsafe_destructor_blind_to_params]
+// Below is the UGEH attribute
+unsafe impl<#[may_dangle] T> Drop for Foo<T> {
     fn drop(&mut self) { }
 }
 

src/test/run-pass/issues/issue-28498-ugeh-with-lifetime-param.rs

@@ -1,12 +1,11 @@
 // run-pass
-#![allow(deprecated)] // FIXME: switch to `#[may_dangle]` below.
 
 // Demonstrate the use of the unguarded escape hatch with a lifetime param
 // to assert that destructor will not access any dead data.
 //
 // Compare with compile-fail/issue28498-reject-lifetime-param.rs
 
-#![feature(dropck_parametricity)]
+#![feature(dropck_eyepatch)]
 
 #[derive(Debug)]
 struct ScribbleOnDrop(String);
@@ -19,10 +18,9 @@ impl Drop for ScribbleOnDrop {
 
 struct Foo<'a>(u32, &'a ScribbleOnDrop);
 
-impl<'a> Drop for Foo<'a> {
-    #[unsafe_destructor_blind_to_params]
+unsafe impl<#[may_dangle] 'a> Drop for Foo<'a> {
     fn drop(&mut self) {
-        // Use of `unsafe_destructor_blind_to_params` is sound,
+        // Use of `may_dangle` is sound,
         // because destructor never accesses `self.1`.
         println!("Dropping Foo({}, _)", self.0);
     }

src/test/run-pass/issues/issue-28498-ugeh-with-passed-to-fn.rs

@@ -1,5 +1,4 @@
 // run-pass
-#![allow(deprecated)] // FIXME: switch to `#[may_dangle]` below.
 
 // Demonstrate the use of the unguarded escape hatch with a type param in negative position
 // to assert that destructor will not access any dead data.
@@ -11,7 +10,7 @@
 //
 // Compare with run-pass/issue28498-ugeh-with-passed-to-fn.rs
 
-#![feature(dropck_parametricity)]
+#![feature(dropck_eyepatch)]
 
 #[derive(Debug)]
 struct ScribbleOnDrop(String);
@@ -24,10 +23,9 @@ impl Drop for ScribbleOnDrop {
 
 struct Foo<T>(u32, T, Box<for <'r> fn(&'r T) -> String>);
 
-impl<T> Drop for Foo<T> {
-    #[unsafe_destructor_blind_to_params]
+unsafe impl<#[may_dangle] T> Drop for Foo<T> {
     fn drop(&mut self) {
-        // Use of `unsafe_destructor_blind_to_params` is sound,
+        // Use of `may_dangle` is sound,
         // because destructor never passes a `self.1` to the callback
         // (in `self.2`) despite having it available.
         println!("Dropping Foo({}, _)", self.0);

src/test/run-pass/issues/issue-28498-ugeh-with-trait-bound.rs

@@ -1,12 +1,11 @@
 // run-pass
-#![allow(deprecated)] // FIXME: switch to `#[may_dangle]` below.
 
 // Demonstrate the use of the unguarded escape hatch with a trait bound
 // to assert that destructor will not access any dead data.
 //
 // Compare with compile-fail/issue28498-reject-trait-bound.rs
 
-#![feature(dropck_parametricity)]
+#![feature(dropck_eyepatch)]
 
 use std::fmt;
 
@@ -19,12 +18,11 @@ impl Drop for ScribbleOnDrop {
     }
 }
 
-struct Foo<T:fmt::Debug>(u32, T);
+struct Foo<T: fmt::Debug>(u32, T);
 
-impl<T:fmt::Debug> Drop for Foo<T> {
-    #[unsafe_destructor_blind_to_params]
+unsafe impl<#[may_dangle] T: fmt::Debug> Drop for Foo<T> {
     fn drop(&mut self) {
-        // Use of `unsafe_destructor_blind_to_params` is sound,
+        // Use of `may_dangle` is sound,
         // because destructor never accesses the `Debug::fmt` method
         // of `T`, despite having it available.
         println!("Dropping Foo({}, _)", self.0);

src/test/ui/span/issue28498-reject-lifetime-param.rs

@@ -16,7 +16,7 @@ struct Foo<'a>(u32, &'a ScribbleOnDrop);
 
 impl<'a> Drop for Foo<'a> {
     fn drop(&mut self) {
-        // Use of `unsafe_destructor_blind_to_params` is unsound,
+        // Use of `may_dangle` is unsound,
         // because destructor accesses borrowed data in `self.1`
         // and we must force that to strictly outlive `self`.
         println!("Dropping Foo({}, {:?})", self.0, self.1);

src/test/ui/span/issue28498-reject-passed-to-fn.rs

@@ -16,7 +16,7 @@ struct Foo<T>(u32, T, Box<for <'r> fn(&'r T) -> String>);
 
 impl<T> Drop for Foo<T> {
     fn drop(&mut self) {
-        // Use of `unsafe_destructor_blind_to_params` is unsound,
+        // Use of `may_dangle` is unsound,
         // because we pass `T` to the callback in `self.2`
         // below, and thus potentially read from borrowed data.
         println!("Dropping Foo({}, {})", self.0, (self.2)(&self.1));

src/test/ui/span/issue28498-reject-trait-bound.rs

@@ -14,11 +14,11 @@ impl Drop for ScribbleOnDrop {
     }
 }
 
-struct Foo<T:fmt::Debug>(u32, T);
+struct Foo<T: fmt::Debug>(u32, T);
 
-impl<T:fmt::Debug> Drop for Foo<T> {
+impl<T: fmt::Debug> Drop for Foo<T> {
     fn drop(&mut self) {
-        // Use of `unsafe_destructor_blind_to_params` is unsound,
+        // Use of `may_dangle` is unsound,
         // because we access `T` fmt method when we pass `self.1`
         // below, and thus potentially read from borrowed data.
         println!("Dropping Foo({}, {:?})", self.0, self.1);